TWI846567B - Resistance adjustment device for sports equipment - Google Patents

Abstract

A resistance adjustment device for sports equipment includes a metal plate that can be driven to rotate by the user's movement, a displacement seat that can be displaced according to the user's control, and at least one magnet disposed on the displacement seat. The magnet can move closer to or farther from the rotation axis of the metal plate along an adjustment path as the displacement seat moves, so that the area of the magnet projected on the metal plate along the axial direction of the metal plate increases. or decrease to adjust the rotational resistance of the metal disk; in one embodiment, the cross section of the aforementioned magnet is a non-parallelogram, and gradually widens from the side closer to the aforementioned rotation axis to the side farther from the rotation axis, so that in the process where the magnet moves at a constant speed from the end farther from the rotation axis to the end closer to the rotation axis along the aforementioned adjustment path, the increase rate of the aforementioned projection area gradually increases.

Description

Resistance adjustment device for sports equipment

The present invention relates to sports equipment, and more specifically, to a resistance adjustment device for sports equipment.

FIG. 1 shows a prior art exercise bike 90, more specifically, a so-called "spinning bike" which is very popular recently, which allows users to simulate riding a road bike indoors. When a user pedals a crankset 91 of the exercise bike 90, a metal plate 93 is driven to rotate in situ via a transmission system 92. The metal plate 93 has the function of a flywheel, that is, it can generate sufficient rotational inertia when rotating, so that the crankset 91 connected thereto can rotate smoothly and accelerate and decelerate smoothly. In addition, the aforementioned fitness bicycle 90 is provided with a resistance adjustment device 94 that can adjust the rotational resistance of the metal disc 93, such as a common eddy current brake, so that the user can adjust the degree of effort required to pedal according to needs.

A typical structure of the aforementioned resistance adjustment device 94 of the vortex brake type is shown in FIG. 2, which has a displacement seat 95 that can swing within a predetermined angle range according to the swing axis A1. The user can turn an adjustment handle 96 (see FIG. 1) at the front end of the exercise bike 90 to control the position of the displacement seat 95 by shortening or lengthening a steel cable 97 connected to the displacement seat 95; the displacement amount of the displacement seat 95 is proportional to the displacement amount of the aforementioned adjustment handle 96 turned by the user. The displacement seat 95 is provided with two ingot-shaped magnets 98 located at two opposite axial sides of the aforementioned metal disk 93 (Note: the two magnets 98 overlap when viewed along the axial direction, and only one of them is marked in FIG. 2 ); the magnets 98 can move closer to or farther from the axis of the metal disk 93 along an arc-shaped adjustment path T1 across the circular edge 931 of the metal disk 93 as the displacement seat 95 swings, so that the area of the magnets 98 projected on the metal disk 93 along the axial direction of the metal disk 93 increases or decreases. The aforementioned projection area can be understood as the actual effective area of the magnet 98 causing the metal disk 93 to produce an eddy effect. Simply put, at the same rotation speed, the resistance of the magnet 98 to the rotation of the metal disk 93 is proportional to the aforementioned projection area.

Please refer to FIG. 2. When the magnet 98 is located at the end of the adjustment path T1 that is farther from the axis of the metal disk (the left end in the figure), the circular edge of the magnet 98 and the circular edge 931 of the metal disk 93 are in a circumferential relationship at the outer boundary position as shown by the imaginary line 98'. Because the projection area is Therefore, the resistance exerted by the magnet 98 on the metal disk 93 is also the minimum value of the adjustable range. In contrast, when the magnet 98 is located at the end of the aforementioned adjustment path T1 closer to the axis of the metal disk (the right end in the figure), as shown by the imaginary line 98", the circular edge of the magnet 98 is at an angle to the circular edge 931 of the metal disk 93. The internal tangent relationship is present, because the aforementioned projection area is equal to the circular cross-sectional area of the magnet 98 and cannot be larger, so the resistance applied by the magnet 98 to the metal plate 93 is also the maximum value of the adjustable range. It can be imagined that in the process of the magnet 98 moving from the aforementioned outer critical position to the aforementioned inner critical position, the aforementioned projection area will gradually increase from zero to equal to the cross-sectional area of the magnet 98, and the aforementioned resistance will also gradually increase from the minimum value of the adjustable range to the maximum value. However, under the above-mentioned prior art, when the user adjusts the movement resistance by turning the aforementioned adjustment handle 96 to control the position of the magnet 98 on the adjustment path T1, the expected resistance change amount and the actual resistance change amount may differ, and the reasons are as follows:

FIG3 shows the multiple levels of the magnet 98 from the outer critical position to the inner critical position in a sequential manner. The magnet positions in these levels are equally variable. Specifically, the state with the least resistance is set as Lv.0, and the state with the greatest resistance is set as Lv.10. In other words, the highest level is 10 levels higher than the lowest level. Assuming that the magnet positions of Lv.10 and Lv.0 differ by 60 degrees (referring to the angular position of the magnet 98 relative to the swing axis A1), the magnet positions of the two adjacent levels are all 6 degrees different. The black blocks of each level in FIG3 represent the overlapping parts of the magnet 98 and the metal disk 93 in the axial direction. Obviously, each time the magnet 98 moves forward one level, the area of the overlapping portion (i.e., the projected area) will increase a little, so that the resistance will increase accordingly. However, since the cross section of the magnet 98 is circular, in the process of its constant speed displacement from the outer critical position (Lv.0 position) to the inner critical position (Lv.10 position), the increase rate of the projected area will gradually accelerate in the first half and gradually slow down in the second half. The above phenomenon can be more easily understood with reference to FIG. 4: when the magnet 98 is at Lv.0, no part of the circular cross section of the magnet 98 overlaps with the metal disk 93; when the magnet 98 is at Lv.1, a small area (a1) of the edge of the circular cross section of the magnet 98 overlaps with the metal disk 93; when the magnet 98 moves from Lv.1 to Lv.2, the part of the magnet cross section overlapping with the metal disk 93 expands to a slightly larger area (a2); thus, Each time the magnet 98 moves forward a unit distance (for example, swings 6 degrees), the aforementioned overlapping portion will increase a little more, and the area added by each segment will be larger than the previous one, for example, a3 is larger than a2, a4 is larger than a3, and so on; however, after approximately exceeding half of the aforementioned circular cross section, each time the magnet 98 moves forward a unit distance, the area added by each segment of the aforementioned overlapping portion will be smaller than the previous one, for example, a8 is smaller than a7, a9 is smaller than a8, and finally a10 is smaller than a9.

FIG5 is a graph showing the relationship between the area of the overlapping portion and the position of the magnet, wherein the horizontal axis represents the position of the magnet, and indicates 10 equal positions corresponding to the segments, and the vertical axis represents the area of the overlapping portion, and takes the cross-sectional area of the magnet 98 (i.e., the maximum value of the projected area) as 100%, and indicates the percentage of the area of the overlapping portion under each segment relative to the maximum value, which also represents the percentage of the resistance applied by the magnet 98 to the metal disk 93 relative to the maximum resistance that can be applied. As shown in the data in the figure, from Lv.0 to Lv.6, each time the magnet advances a level, the aforementioned resistance increases by 3.0%, 6.0%, 8.5%, 10.6%, 12.3% and 13.5% of the maximum resistance, respectively, indicating that the rate of resistance increase is gradually accelerating; and from Lv.6 to Lv.10, each time the magnet advances a level, the aforementioned resistance increases by 14.0%, 13.5%, 11.7% and 6.9% of the maximum resistance, respectively, indicating that the rate of resistance increase is gradually slowing down. Looking at the curve itself, the slope of the middle segment is relatively large, while the slope of the bottom and top segments is relatively small, which means that the aforementioned resistance responds relatively sensitively to changes in the magnet position in the middle area of the adjustable range, but responds relatively slowly in the lower and higher areas of the adjustable range. According to the proportional relationship shown in Figure 5, the magnet needs to move forward from the aforementioned outer critical position to about 32.8% of the total length of the aforementioned adjustment path T1 in order to increase the resistance from zero to 20% of the maximum resistance; after that, to increase the resistance from 20% of the maximum resistance to 40%, from 40% to 60%, and from 60% to 80%, the magnet only needs to move forward by about 17.0%, 14.7%, and 14.6% of the total length respectively; finally, to increase the resistance from 80% of the maximum resistance to 100%, the magnet needs to move forward by about 21.1% of the total length, and the adjustment efficiency (the ratio of resistance change to displacement distance) becomes lower again.

The above characteristics may cause users to feel the incoordination between the resistance change and the adjustment action when adjusting the exercise resistance, especially for sports equipment such as the aforementioned flywheel, which is often used for high-intensity interval training. Because users may frequently increase and decrease the exercise resistance during exercise, and the range of high and low is quite large, it is easy to feel that the same adjustment action (such as turning the aforementioned adjustment handle 96 to the same angle, or a stage of the staged adjustment) is more obvious at the middle resistance, and less obvious at the low and high resistance. Moreover, from the minimum resistance to the maximum resistance, the speed of the resistance change response adjustment action becomes faster and faster in the first half and slower and slower in the second half. The operation response is neither linear nor has a unified trend. Most obviously, when using a flywheel for high-intensity interval training, the resistance is usually increased from the medium resistance to the high resistance (for example, more than 70% to 80% of the maximum resistance) after a proper warm-up, in order to simulate a situation where one must exert a lot of effort (usually while riding in a standing position) to pedal when climbing a hill or against a headwind. However, when the user wants to perform high-intensity exercise and turns the aforementioned adjustment knob 96 to the end of the adjustable range, the resistance increase rate in the higher range is not as fast as that in the middle range, so the resistance increase may be lower than the user's expectations and needs. In addition, when riding a freewheeling bike, when the user wants to decelerate or even stop the rotating pedal as quickly as possible, or as a safety measure before getting off the bike, the user will turn the aforementioned adjustment knob 96 directly to the end, which means that the resistance reaches the maximum value, making it difficult to rotate the pedal. This final stage of increasing the resistance is even more inefficient.

The present invention aims to solve the problems of the above-mentioned prior art. Its main purpose is to provide a resistance adjustment device for sports equipment, whose operation response has a uniform trend and predictability, and provides a better user experience.

Another purpose of the present invention is to provide a resistance adjustment device for sports equipment, whose operating response in the higher area of the adjustable resistance range is more in line with the user's expectations and needs of increasing the resistance when performing high-intensity exercise.

Another object of the present invention is to provide a resistance adjustment device for sports equipment, which is suitable for use in sports equipment that may need to quickly slow down the inertia of movement during exercise, and has a higher operating efficiency when performing the aforementioned slow down.

Another object of the present invention is to provide a resistance adjustment device for sports equipment, which is particularly suitable as a resistance adjustment device for a flywheel.

In order to achieve the above-mentioned purpose, the resistance adjustment device of the sports equipment provided by the present invention comprises: a frame; a metal plate, which is pivotally arranged on the frame according to a rotation axis and can be rotated by the movement of the user of the sports equipment; the metal plate has a circular edge with the rotation axis as the center; a displacement seat, which is arranged on the frame and can be displaced according to the control of the user; at least one magnet, The magnet is arranged on the displacement seat and can move along an adjustment path across the circular edge of the metal disk to approach or move away from the rotation axis as the displacement seat moves, so that the area of the magnet projected on the metal disk along the axial direction of the metal disk increases or decreases; when the magnet is located at the first end of the adjustment path, the projection area is the minimum value of the adjustable range, and when the magnet is located at the second end of the adjustment path, the projection area is the minimum value of the adjustable range. The projection area is the maximum value of the adjustable range when the second end of the magnet is at the second end of the magnet. The magnet is characterized in that the cross section of the magnet on the radial plane of the rotation axis is non-circular, and the outer edge of the cross section of the magnet includes a first side and a second side opposite to each other, the first side and the second side each have a head end and a tail end, the two heads are located on the same side and are separated by a convergent distance, and the two tail ends are located on the other side and are separated by a convergent distance. And at a divergence distance greater than the convergence distance, the width of the magnetic cross section between the first side and the second side gradually widens from the side where the two head ends are located to the side where the two tail ends are located; when the magnet is located at the first end of the adjustment path, the head ends of the first side and the second side of the magnetic cross section are closer to the circular edge of the metal disk than the tail ends.

In a possible implementation, the first side and the second side of the magnetic cross section are two non-parallel straight lines.

In a possible implementation, when the magnet is located at the first end of the adjustment path, when observed along the axial direction of the metal disk, at least one of the first side and the second side of the cross section of the magnet intersects with the circular edge of the metal disk at one point.

In a possible implementation, during the process of the magnet moving from the first end to the second end along the adjustment path, at least when the projection area increases from the minimum value by 5% to 95% of the difference between the maximum value and the minimum value, the circular edge of the metal disk remains to pass through the first side and the second side of the cross section of the magnet simultaneously when observed along the axial direction of the metal disk.

In a possible implementation, the outer edge of the aforementioned magnetic cross section further includes a short side, and the aforementioned short side connects the aforementioned first side and the aforementioned head end of the aforementioned second side; when the aforementioned magnet is located at the aforementioned first end of the aforementioned adjustment path, when observed along the axial direction of the aforementioned metal disk, the aforementioned short side of the aforementioned magnetic cross section approaches or overlaps with the aforementioned circular edge of the aforementioned metal disk.

In a possible implementation, the outer edge of the aforementioned magnetic cross section further includes a long side, and the aforementioned long side connects the aforementioned first side and the aforementioned tail ends of the aforementioned second side; when the aforementioned magnet is located at the aforementioned second end of the aforementioned adjustment path, when observed along the axial direction of the aforementioned metal disk, the aforementioned long side of the aforementioned magnetic cross section approaches or overlaps with the aforementioned circular edge of the aforementioned metal disk.

In a possible implementation, the displacement seat is pivoted on the frame according to a swing axis parallel to the rotation axis; the relative direction of the first side and the second side of the magnetic cross section corresponds to the relative direction of the magnet and the swing axis.

In a possible implementation, the first side of the magnetic cross section is closer to the swing axis than the second side, and the length of the second side is greater than the length of the first side.

In a possible implementation, the outer edge of the aforementioned magnetic cross section further includes a short side and a long side opposite to each other, the short side connects the head ends of the aforementioned first side and the aforementioned second side, and the long side connects the tail ends of the aforementioned first side and the aforementioned second side; when the aforementioned magnet is located at the aforementioned first end of the aforementioned adjustment path, the aforementioned short side of the aforementioned magnetic cross section approaches or overlaps with the aforementioned circular edge of the aforementioned metal disk when observed along the axial direction of the aforementioned metal disk; when the aforementioned magnet is located at the aforementioned second end of the aforementioned adjustment path, the aforementioned long side of the aforementioned magnetic cross section approaches or overlaps with the aforementioned circular edge of the aforementioned metal disk when observed along the axial direction of the aforementioned metal disk.

In a possible implementation, the displacement frame is provided with two aforementioned magnets located at two opposite sides of the aforementioned metal disk in the axial direction, each of the aforementioned magnets has a shape corresponding to the inner side surface of the aforementioned cross section, the aforementioned inner side surface is parallel to the corresponding side surface of the aforementioned metal disk, and the spacing between them remains unchanged; the shapes of the aforementioned two magnets projected along the axial direction of the aforementioned metal disk on the aforementioned metal disk overlap.

Through the above technical solution, the resistance adjustment device of the sports equipment provided by the present invention has at least the following functions:

1. In the process that the magnet moves from the first end to the second end at a constant speed along the adjustment path, the rate of increase of the projected area gradually accelerates overall, that is, the rate of increase of the resistance gradually accelerates overall, so that the operation response has a uniform trend and predictability, and the user experience is better.

Second, in the higher area of the adjustable resistance range, the rate of increasing resistance can still gradually increase as the resistance increases, which is more in line with the user's expectations and needs of increasing resistance for high-intensity exercise.

3. In the final stage of increasing resistance, the maximum resistance can be reached with a shorter displacement distance and a shorter time, so it is suitable for use in sports equipment that may need to quickly slow down the inertia of movement during exercise.

4. It is particularly suitable as a resistance adjustment device for flywheels that can be used for high-intensity interval training.

10: Resistance adjustment device

15: Frame

20: Transmission system

21: Drive shaft

22: Large pulley

23: Small pulley

24: Ring belt

30:Metal plate

31: Rounded edges

40: Displacement seat

41: Side panels

42: Positioning pin

50: Magnet

51: Inner side

52: First side

53: Second side

54: Short side

55: Long side

60: Friction block

61: Friction surface

70: Torsion spring

80: Steel cable

230:Metal plate

231: Rounded edges

232: radial direction

250: Magnet

330:Metal plate

332: radial direction

350: Magnet

430:Metal plate

431: Rounded edges

450: Magnet

530:Metal plate

531: Rounded edge

550: Magnet

90: Exercise bike

91: Pedal crank set

92: Transmission system

93:Metal plate

931: Rounded edges

94: Resistance adjustment device

95: Displacement seat

96: Adjustment handle

97: Steel cable

98: Magnet

98’: Outside boundary position

98”: Inner critical position

99:Frame

A1: Swing axis

A2: Rotating axis/metal disc axis

A3: Swing axis

a1~a10: Increased area at each level

b1~b10: Increased area at each level

T1: Adjust the path

T2: Adjust the path

FIG1 is a side view of an exercise bike in the prior art.

Figure 2 is a partial enlarged view of the resistance adjustment device in the fitness bike of Figure 1, in which the adjustment path of the magnet and the critical positions at both ends are marked.

Figure 3 illustrates the multiple segments of the magnet in Figure 2 from the outer critical position to the inner critical position in the form of sequential changes, where the black area represents the overlapping part of the magnet and the metal disk in the axial direction.

Figure 4 shows the variation of the aforementioned overlapping portion of the magnet in Figure 3 at each segment.

Figure 5 is a curve diagram showing the relationship between the area of the overlapping portion in Figure 3 and the position of the magnet.

Figure 6 is a side view of a resistance adjustment device of a preferred embodiment of the present invention and the transmission system of the sports equipment used therein.

Figure 7 is a bottom view of the resistance adjustment device and transmission system of Figure 6;

FIG8A is a partial enlarged view of the resistance adjustment device in FIG6, showing that the magnet is located at the first end of the adjustment path.

Figure 8B is similar to Figure 8A, but shows the magnet at the second end of the adjustment path.

FIG9 is a three-dimensional diagram of the displacement seat and its associated structure in the resistance adjustment device in FIG6.

Figure 10 is a three-dimensional diagram of the displacement seat and its associated structure in Figure 9 from another perspective.

FIG11 illustrates the multiple sections of the magnet in FIG8A and FIG8B from the first end to the second end of the adjustment path in the form of a sequence change, wherein the black area represents the overlapping portion of the magnet and the metal disk in the axial direction.

Figure 12 shows the variation of the aforementioned overlapping portion of the magnet in Figure 11 at each segment.

FIG13 is a curve diagram showing the relationship between the area of the overlapping portion in FIG11 and the position of the magnet.

Figure 14 shows the shape and displacement direction of the magnet in another possible implementation of the present invention.

Figure 15 shows the shape and displacement direction of the magnet in another possible implementation of the present invention.

Figure 16 shows a relative relationship between the magnet and the metal disk in the present invention.

Figure 17 shows another relative relationship between the magnet and the metal disk in the present invention.

Please refer to FIG. 6 and FIG. 7, which show a preferred embodiment of the present invention wherein the resistance adjustment device 10 is assembled at the driven end of a transmission system 20 of a sports equipment. In order to form a comparison with the prior art described above, the present embodiment demonstrates that the resistance adjustment device 10 is also applied to a flywheel as shown in FIG. 1, so that the user can adjust the exercise resistance of pedaling according to the needs. However, it should be noted that the resistance adjustment device of the present invention can also be applied to other types of fitness bikes (such as upright bikes or recumbent bikes) through similar embodiments or other appropriate assembly methods, and even to various sports equipment other than fitness bikes, including cardiopulmonary training equipment (such as elliptical exercise machines, steppers, rowing machines, etc.), weight training equipment, hybrid sports equipment (such as the running and weight training dual-purpose sports equipment disclosed in U.S. Patent No. 10,398,933), and any sports equipment that can use vortex brakes to generate movement resistance and can adjust the resistance strength. The structure and function of the present invention described in this specification, regardless of the general concept or specific embodiment, are also applicable to other types of fitness bicycles or other types of sports equipment unless explicitly limited to flywheel vehicles.

Back to the present embodiment, the aforementioned resistance adjustment device 10 includes a circular plate-shaped metal disc 30, which is pivoted on a frame 15 according to a rotation axis A2 passing through its own center and corresponding to the left-right axis of the sports equipment, and can rotate in situ on the frame 15. The aforementioned frame 15 is usually a metal bracket that fixes the sports equipment when it is in use. For example, the frame 15 shown in FIG. 6 can correspond to the frame 99 that directly supports the pedal crank set 91 and the metal disc 93 in FIG. 1. Similar to the prior art of FIG. 1, the aforementioned metal disc 30 is integrally formed of aluminum, has a predetermined diameter and thickness, and the circular disc surface is flat without hollows, and can generate sufficient rotational inertia when rotating. When the user uses the sports equipment to perform a specific sport, the metal plate 30 can be driven to rotate by the user's sport. In this example, the user's sport output is transmitted to the metal plate 30 in the form of torque via the transmission system 20. Specifically, the transmission system 20 includes a driving shaft 21, a large belt pulley 22, a small belt pulley 23 and an endless belt 24. The driving shaft 21 is pivotally arranged on the frame 24 according to the left and right axes. The large pulley 22 and the small pulley 23 are coaxially connected to the driving shaft 21 and the metal disc 30, respectively. The endless belt 24 is wound around the large pulley 22 and the small pulley 23 at the same time. Thus, when the user's sports output (such as pedaling a bicycle with both feet) drives the driving shaft 21 (such as corresponding to the crankshaft of a bicycle) to rotate, the metal disc 30 is driven to rotate at a higher speed. In sports equipment such as flywheels or elliptical exercise machines, the large pulley 22 is usually fixedly connected to the driving shaft 21, and the small pulley 23 is also fixedly connected to the metal plate 30. In other words, the driving shaft 21 and the metal plate 30 are bidirectionally transmitted. Therefore, during the movement, the inertial force of the metal plate 30 driven by the driving shaft 21 is also When the force acts on the driving shaft 21, the driving shaft 21 can rotate smoothly and accelerate and decelerate smoothly; however, if it is the aforementioned upright or reclining bicycle, a one-way bearing is usually set between the aforementioned large belt pulley 22 and the aforementioned driving shaft 21, so that the pedals of the bicycle can stop or even reverse at will during the forward movement without being restrained by the inertial force. The above structure of the metal plate 30 being driven to rotate by the user's movement is basically still a prior art.

Please refer to Figures 8A and 8B. The resistance adjustment device 10 further includes a displacement seat 40 near the circular edge 31 of the metal plate 30. The displacement seat 40 is disposed on the frame 15 in a displaceable manner. In the present embodiment, the displacement seat 40 is pivoted on the frame 15 according to a swing axis A3 corresponding to the left-right axis of the sports equipment. It can be swung and displaced within a predetermined angle range according to the control of the user, for example, it can swing back and forth between the two positions shown in Figures 8A and 8B, and stop at a desired position. The position control of the displacement seat 40 also adopts the conventional technology in this field, that is: a torsion spring 70 is provided between the displacement seat 40 and the frame 15 (see Figures 9 and 10), and the elastic force of the torsion spring 70 can make the displacement seat 40 swing relative to the frame 15 in a first rotation direction (clockwise direction in Figures 8A and 8B); one end of a steel cable 80 is connected to the displacement seat 40, and the other end is connected to a winding wheel (not shown in the figure, usually located near the control console of the sports equipment), and the winding wheel is connected to an adjustment member (such as the adjustment handle 96 in Figure 1, or an adjustment button in the form of a knob) that can rotate in a step-by-step or step-by-step manner within a predetermined adjustable range; when the user When the adjustment member is rotated by a displacement amount in a direction representing an increase in resistance, the winding wheel that rotates accordingly will reel up the steel cable 80 by a corresponding length, so that the displacement seat 40 is pulled by the steel cable 80 and resists the elastic force of the torsion spring 70 to swing to a corresponding angle in the opposite second rotation direction (counterclockwise direction in Figures 8A and 8B); when the user rotates the adjustment member by a displacement amount in a direction representing a decrease in resistance, the winding wheel that rotates accordingly will release the steel cable 80 by a corresponding length, so that the displacement seat 40 that is continuously acted upon by the torsion spring 70 swings to a corresponding angle in the first rotation direction; when no external force is applied, the winding wheel can be fixed at the current angle by friction. In simple terms, within a predetermined adjustable range, the position of the adjustment member determines the position of the displacement seat 40, and when adjusting, the displacement amount/displacement rate of the adjustment member and the displacement amount/displacement rate of the displacement seat 40 maintain a certain proportional relationship. For example, assuming that the adjustable range of the adjustment member is 200 degrees and the adjustable range of the displacement seat 40 is 50 degrees, when the adjustment member is rotated 20 degrees in a certain rotation direction, the displacement seat 40 will swing 5 degrees in the corresponding rotation direction.

Please refer to FIG. 9 and FIG. 10 . The displacement seat 40 has two side plates 41 which are parallel to each other in the left-right axial direction. A plate-shaped magnet 50 is attached to the inner side of each side plate 41. The two magnets 50 are respectively located on two opposite axial sides of the metal disk 30 (see FIG. 7 ). The inner side surface 51 of each magnet 50 is parallel to and close to the corresponding side surface of the metal disk 30. Even if the displacement seat 40 is swung and displaced and/or the metal disk 30 is rotated in place, the axial distance between each magnet 50 and the metal disk 30 remains unchanged. One of the magnets 50 faces the metal disk 30 with its N pole, and the other magnet 50 faces the metal disk 30 with its S pole. In this embodiment, the shape of the inner side surface 51 of each magnet 50 (corresponding to the cross-sectional shape of the magnet 50 on the radial plane of the aforementioned rotation axis A2) is a non-parallelogram. Because the shapes and sizes of the two magnets 50 are the same and the positions and angles correspond, when observed along the axial direction of the metal disk 30 (for example, Figures 8A and 8B), the non-parallelogram cross-sections of the two magnets 50 completely overlap.

As shown in FIG12 , the outer edge of the cross section of each magnet 50 includes a first side 52 and a second side 53 opposite to each other, and a short side 54 and a long side 55 opposite to each other, and all four (52, 53, 54, 55) are straight lines and no two of them are parallel. The relative direction of the first side 52 and the second side 53 corresponds to the relative direction of the magnet 50 and the swing axis A3 (roughly the up-down direction in this embodiment), wherein the first side 52 is closer to the swing axis A3 than the second side 53 (in this embodiment, the magnet 50 is located below the swing axis A3, and the second side 53 is located below the first side 52), and the length of the second side 53 is greater than the length of the first side 52. The first side 52 and the second side 53 each have a head end and a tail end, the two head ends are located on the same side (the right side in FIG. 12) and are separated by a convergence distance, the two tail ends are located on the other side (the left side in FIG. 12) and are separated by a divergence distance greater than the convergence distance, and the width of the cross section between the first side 52 and the second side 53 gradually widens from the side where the two head ends are located to the side where the two tail ends are located. The short side 54 connects the head ends of the first side 52 and the second side 53, and its length is equal to the convergence distance. The long side 55 connects the tail ends of the first side 52 and the second side 53, and its length is equal to the divergence distance.

As shown in Figures 9 and 10, a plurality of transverse positioning pins 42 are also provided on the inner side of each side plate 41 of the displacement seat 40, and the bottom end surface of each magnet 50 (corresponding to the aforementioned second side 53) abuts against two of the positioning pins 42, and the front end surface of each magnet 50 (corresponding to the aforementioned long side 55) abuts against another positioning pin 42. With the design of the positioning pins 42, the assembler can quickly and accurately position the magnet 50 when bonding it to the displacement seat 40, and at the same time, the stability of the magnet 50 on the displacement seat 40 can be increased.

Please refer to FIG. 8A and FIG. 8B again. When the displacement seat 40 is controlled by the user to be swung and displaced according to the swung axis A3, the magnet 50 can move along an arc-shaped adjustment path T2 across the circular edge 31 of the metal disk 30 to approach or move away from the rotation axis (hereinafter referred to as the metal disk axis) A2 of the metal disk 30, so that the area of the magnet 50 projected on the metal disk 30 along the axial direction of the metal disk 30 (i.e., the viewing direction of FIG. 8A and FIG. 8B) increases or decreases. Because the shapes of the two magnets 50 projected on the metal disk 30 along the axial direction of the metal disk 30 overlap, the relationship between the magnet position and the projected area described below is applicable to any magnet 50. When the magnet 50 is located at the end of the adjustment path T2 farther from the metal disk axis A2 (e.g., the left end in the figure, hereinafter referred to as the first end), the projected area is the minimum value of the adjustable range. Conversely, when the magnet 50 is located at the end of the adjustment path T2 closer to the metal disk axis A2 (e.g., the right end in the figure, hereinafter referred to as the second end), the projected area is the maximum value of the adjustable range. In this embodiment, when the magnet 50 is located at the aforementioned first end, as shown in FIG8A , the magnet 50 is adjacent to the outer side of the circular edge 31 of the metal disk 30 , and the aforementioned projection area is substantially zero; when the magnet 50 is located at the aforementioned second end, as shown in FIG8B , the magnet 50 is adjacent to the inner side of the circular edge 31 of the metal disk 30 , and the aforementioned projection area is substantially equal to the cross-sectional area of the magnet 50 .

In more detail, the relative direction of the aforementioned short side 54 and the aforementioned long side 55 of the magnet cross section corresponds to the displacement direction of the magnet 50 approaching or moving away from the metal disk axis A2 along the aforementioned adjustment path T2 (roughly the front-back direction in this embodiment, i.e. the left-right direction in Figures 8A and 8B), wherein the aforementioned short side 54 is closer to the metal disk axis A2 than the aforementioned long side 55.

When the magnet 50 is located at the first end of the adjustment path T2, when observed along the axial direction of the metal disk 30, the head ends of the first side 52 and the second side 53 of the magnet cross section are closer to the circular edge 31 of the metal disk 30 than the tail ends. In other words, the narrower side of the magnet cross section (i.e., the side where the short side 54 is located) is closer to the circular edge 31 than the wider side (i.e., the side where the long side 55 is located). At least one of the first side 52 and the second side 53 intersects with the circular edge 31 at a point. In the present embodiment, the short side 54 approaches or overlaps with the circular edge 31, and the head end of the first side 52 and/or the second side 53 is exactly located on the circular edge 31, so that the projected area is zero (or small enough to be considered zero). Correspondingly, the resistance applied by the magnet 50 to the metal disk 30 is the minimum value of the adjustable range. In other possible implementations (not shown), when the magnet 50 is located at the first end of the aforementioned adjustment path T2, when observed along the axial direction of the metal disk 30, the aforementioned first side 52 and the aforementioned second side 53 of the magnet cross section are both located inside the circular edge 31 of the metal disk 30. In other words, the narrower side of the aforementioned magnet cross section is partially located inside the aforementioned circular edge 31, so that the minimum value of the aforementioned projection area is greater than zero.

In contrast, in the present embodiment, when the magnet 50 is located at the second end of the aforementioned adjustment path T2, when observed along the axial direction of the metal disk 30, the magnet 50 completely (or almost completely) overlaps the metal disk 30, and the aforementioned long side 55 of the magnet cross section approaches or overlaps with the circular edge 31 of the metal disk 30, so that the aforementioned projected area is equal to (or almost close to) the cross-sectional area of the magnet 50. Correspondingly, the resistance applied by the magnet 50 to the metal disk 30 is the maximum value of the adjustable range. In practice, the cross-sectional area of the magnet 50 can be compared to the circular cross-sectional area of the ingot magnet 98 in the prior art, so that the maximum resistance that the magnet 50 may exert on the metal disk 30 is equal to the maximum resistance in the prior art (assuming that the metal disk specification, magnet thickness and material parameters are the same as before). Of course, the magnet size and maximum resistance in the present invention can still be appropriately selected according to practical needs. In other possible implementations (not shown), when the magnet 50 is located at the second end of the aforementioned adjustment path T2, when observed along the axial direction of the metal disk 30, the aforementioned tail ends of the aforementioned first side 52 and the aforementioned second side 53 of the magnet cross section are both located outside the circular edge 31 of the metal disk 30. In other words, the wider side of the aforementioned magnet cross section is partially located outside the aforementioned circular edge 31, so that the maximum value of the aforementioned projected area is less than the cross-sectional area of the magnet 50.

As shown in FIG. 9 and FIG. 10 , in the present embodiment, a friction block 60 made of rubber material is further provided on the displacement seat 40. The friction block 60 is fixed between the two side plates 41, and is located at a side of the two magnets 50 that is farther from the metal disk axis A2. The friction block 60 has a friction surface 61 facing the metal disk 30. The friction surface 61 (ignoring the grooves on the surface and considering it as a plane) is roughly aligned with the long sides 55 of the two magnets 50. When the user controls the displacement seat 40 to swing toward the aforementioned second rotation direction until the magnet 50 reaches the vicinity of the second end of the aforementioned adjustment path T2, in addition to the magnet 50 exerting the maximum resistance on the metal disk 30, the aforementioned friction surface 61 will also contact the circumferential surface of the metal disk 30, directly hindering the rotation of the metal disk 30 with friction. According to the implementation selection or the wear state of the friction block 60, when observed along the axial direction of the metal disk 30, the friction surface 61 of the aforementioned friction block 60 may be completely or partially located within the cross-sectional range of the magnet 50, or may be completely located outside the cross-sectional range of the magnet 50. The aforementioned friction block 60 is mainly used for rapid braking or preventing the metal disk 30 from rotating, and is particularly suitable for use in flywheel vehicles; on the contrary, some sports equipment may not require the aforementioned friction block.

It should also be noted that, as in the prior art, in order to ensure that the aforementioned projection area of the magnet 50 can be adjusted to zero at the minimum and/or can be adjusted to be equal to the cross-sectional area of the magnet 50 at the maximum, the possible displacement range of the magnet 50 usually slightly exceeds the position shown in FIG. 8A and/or FIG. 8B. For example, in response to the user turning the aforementioned adjustment member (such as the adjustment knob 96), the displacement seat 40 may slightly swing from the position shown in FIG. 8A to the clockwise direction and/or slightly swing from the position shown in FIG. 8B to the counterclockwise direction until the displacement seat 40 or the aforementioned adjustment member is blocked by a preset blocking structure (not shown in the figure), or the friction surface 61 of the aforementioned friction block 60 abuts against the circumferential surface of the metal plate 30. However, even if the magnet 50 moves further away from the metal disk axis A2 from the position shown in FIG. 8A (i.e., the first end of the aforementioned adjustment path T2), the aforementioned projection area will still be zero and will not be smaller; similarly, even if the magnet moves closer to the metal disk axis A2 from the position shown in FIG. 8B (i.e., the second end of the aforementioned adjustment path T2), the aforementioned projection area will still be equal to the cross-sectional area of the magnet 50 and will not be larger. This means that the displacement of the magnet 50 can only increase or decrease the aforementioned projection area within the range of the aforementioned adjustment path T2, or in other words, can increase or decrease the resistance applied by the magnet 50 to the metal disk 30, thereby producing the effect of adjusting the resistance (Note: In fact, the range of the aforementioned adjustment path T2 is defined by the two critical positions where the magnet 50 can apply the minimum resistance and the maximum resistance to the metal disk 30.). Based on the above meaning, the "adjustable range" of the magnet 50 or the displacement seat 40 (such as 50 degrees in the above example) basically corresponds to the range of the aforementioned adjustment path T2, rather than the practical possible displacement range; the same is true for the "adjustable range" of the aforementioned adjustment member used to control the displacement of the displacement seat 40 and the magnet 50 (such as 200 degrees in the above example).

It can be imagined that when the aforementioned adjustment member is located at one end of its adjustable range, the magnet 50 is located at the first end of the aforementioned adjustment path T2. Conversely, when the aforementioned adjustment member is located at the other end of its adjustable range, the magnet 50 is located at the second end of the aforementioned adjustment path T2. Moreover, if the aforementioned adjustment member is moved from one end of its adjustable range to the other end at a constant speed, the magnet 50 will also move from the first end to the second end along the adjustment path T2 at a constant speed at the same time. In short, the position of the magnet 50 in the aforementioned adjustment path T2 reflects the position of the aforementioned adjustment member in its adjustable range at any time.

FIG. 11 shows the multiple levels of the magnet 50 from the first end to the second end of the aforementioned adjustment path T2 in the form of a sequence change. The magnet positions in these levels are equally variable. Specifically, the state with the minimum resistance is set as Lv.0, and the state with the maximum resistance is set as Lv.10. Assuming that the adjustable range of the magnet 50 (i.e., the arc of the aforementioned circular adjustment path T2) is 50 degrees, the magnet positions of two adjacent levels are all 5 degrees apart. The concept to be expressed here is that if the aforementioned adjustment piece rotates one-tenth of the total length of its adjustable range (for example, 20 degrees out of 200 degrees), the magnet 50 will also move one-tenth of the total length of its adjustable range, for example, from the position of Lv.0 in the figure to the position of Lv.1; if the aforementioned adjustment piece rotates half of the total length of its adjustable range, the magnet 50 will also move half of the total length of its adjustable range, for example, from the position of Lv.0 in the figure to the position of Lv.5.

The black areas in each segment in FIG. 11 represent the overlapped portions of the magnet 50 and the metal disk 30 in the axial direction. FIG. 12 shows the variation of the overlapped portions of the magnet 50 in each segment, wherein: when the magnet 50 is at Lv.0, no portion of the magnet cross section overlaps with the metal disk 30; when the magnet 50 is at Lv.1, a small area (b1) on the side where the short side 54 of the magnet cross section is located overlaps with the metal disk 30; when the magnet When magnet 50 moves from Lv.1 to Lv.2, the overlapping portion of the magnet cross section and the metal plate 30 will expand by a slightly larger area (b2); the same applies to the following. That is, when magnet 50 moves to Lv.3, Lv.4, Lv.5, ..., Lv.10, the overlapping portion will increase by b3, b4, b5, ..., b10, and finally be equal to (or close to) the cross-sectional area of magnet 50.

As can be seen from FIG. 12 , the 10 areas b1 to b10 have substantially equal transverse widths, but the longitudinal lengths gradually increase from b1 being substantially equal to the length of the short side 54 to b10 being substantially equal to the length of the long side 55. Obviously, every time the magnet 50 moves forward by a unit distance (e.g., swinging 5 degrees), the portion of the magnet cross section overlapping the metal disk 30 will increase a little, and the area added in each section will be larger than the previous one, from the lowest section (the aforementioned projected area is zero) to the highest section (the aforementioned projected area is equal to the cross-sectional area of the magnet 50). For example, in FIG. 12 , a2 is larger than a1, a3 is larger than a2, a4 is larger than a5, ..., until the last a10 is also larger than the previous a9. It must be emphasized here that the highest level is set to Lv.10, and the cross-section of the magnet 50 is divided into 10 small blocks according to the number of levels. This is just a simple example for the convenience of explanation. In practice, the rotation of the aforementioned adjustment member (such as the adjustment handle 96) used to control the displacement of the magnet 50 may be a step-by-step rotation with various numbers of stages such as 16 stages, 20 stages, 24 stages, etc., or the rotation of the aforementioned adjustment member may be a stepless rotation, that is, it can be rotated to any angle and stopped at any position within the adjustable range. In other words, the controlled displacement of the magnet 50 does not actually have a specific unit distance. In any case, when the magnet 50 moves along the adjustment path T2 from the direction of the first end to the direction of the second end, the overlapping portion of the magnet 50 and the metal plate 30 expands from the narrower side of the magnet cross section (i.e., the side where the short side 54 is located) to the wider side (i.e., the side where the long side 55 is located), so the increase rate of the projected area always gradually accelerates.

FIG13 is a graph showing the relationship between the aforementioned projection area and the magnet position in this embodiment. Similar to the representation method of FIG5, the horizontal axis in FIG13 represents the magnet position, indicating 10 equal positions corresponding to the segments, and the vertical axis represents the aforementioned projection area, with the cross-sectional area of the magnet 50 as the maximum value, indicating the percentage of the aforementioned projection area under each segment relative to the aforementioned maximum value, which also represents the percentage of the resistance applied by the magnet 50 to the metal disk 30 relative to the maximum resistance that can be applied. As shown in the data in the figure, from Lv.0 to Lv.10, each time the magnet advances one level (i.e. one tenth of the total length of the aforementioned adjustment path T2), the aforementioned resistance increases by 7.0%, 7.6%, 8.2%, 8.9%, 9.6%, 10.3%, 11.0%, 11.8%, 12.7% and 12.9% of the maximum resistance, indicating that the rate of resistance increase is gradually accelerating overall. From another point of view, based on the proportional relationship shown in Figure 13, in order to increase the resistance from zero to 20% of the maximum resistance, from 20% to 40%, from 40% to 60%, from 60% to 80%, and from 80% to 100%, the magnet needs to move forward approximately 26.7%, 22.0%, 19.0%, 16.7% and 15.6% of the total length of the aforementioned adjustment path T2, respectively, which also shows that the adjustment efficiency (the ratio of resistance change to displacement distance) gradually increases.

As can be seen from the above preferred embodiments, the resistance adjustment device 10 of the present invention is designed by designing the inner side surface 51 of the magnet 50 facing the metal disk 30 (corresponding to the cross section of the magnet 50 on the radial plane of the metal disk axis A2) into a specific geometric shape, and arranging the magnet 50 and the metal disk 30 into a specific relative relationship (including the magnet 50 moving along the aforementioned adjustment path T2 when the magnet 50 moves). , the position and angle of the aforementioned magnet cross section relative to the metal disk 30 change), so that in the process of the magnet 50 moving from the first end to the second end along the aforementioned adjustment path T2 at a constant speed, the rate of increase of the area of the axial projection of the magnet 50 on the metal disk 30 gradually accelerates as a whole, that is, the rate of increase of the resistance applied by the magnet 50 to the metal disk 30 gradually accelerates as a whole. In the process of the magnet 50 moving from the aforementioned first end to the aforementioned second end along the aforementioned adjustment path T2 (at least when the aforementioned projection area increases from the minimum value to 5% to 95% of the difference between the maximum value and the minimum value), when observed along the axial direction of the metal disk 30, the circular edge 31 of the metal disk 30 keeps passing through the aforementioned first side 52 and the aforementioned second side 53 of the magnet cross section at the same time.

By means of the aforementioned resistance adjustment device provided by the present invention, when users of sports equipment adjust the exercise resistance, the operation response has a uniform trend and predictability, so the user experience is better. Secondly, in the higher area of the adjustable resistance range, the rate of increasing the resistance can still gradually increase as the resistance increases, which is more in line with the user's expectations and needs of increasing the resistance for high-intensity exercise. In addition, because the maximum resistance can be reached with a shorter displacement distance and a shorter time in the final stage of increasing the resistance, it is suitable for use in sports equipment that may need to quickly slow down the movement inertia during exercise. Combining the above effects and characteristics, the present invention is particularly suitable as a resistance adjustment device for flywheel vehicles that can be used for high-intensity interval training.

FIG. 14 shows another possible embodiment of the present invention (partial), which is different from the above-mentioned preferred embodiment in that the cross section of the magnet 250 is trapezoidal, and its outer edge includes a first side (top side in the figure) and a second side (bottom side in the figure) that are opposite but not parallel, and a short side (right side in the figure) and a long side (left side in the figure) that are parallel and opposite to each other; in addition, when adjusting the resistance, the magnet 250 is along the radial direction 230 of the metal plate 230. 2 is moved closer to or farther from the axis of the metal disk (located to the right of the magnet 250 in the figure, but not shown in the figure) across the circular edge 231 of the metal disk 230, so that the area of the magnet 250 projected on the metal disk 230 along the axial direction of the metal disk 230 increases or decreases; wherein the relative direction of the aforementioned short side and the aforementioned long side of the magnet cross section corresponds to the displacement direction of the magnet 250 approaching or moving away from the axis of the metal disk, and the aforementioned short side is closer to the axis of the metal disk than the aforementioned long side. Thus, as the magnet 250 moves toward the axis of the metal disk, the axially overlapping portion of the magnet 250 and the metal disk 230 will expand from the narrower side of the magnet cross section to the wider side (as indicated by the imaginary lines on the magnet cross section in the figure), so that the rate of increase of the aforementioned projected area gradually accelerates, that is, the rate of increase of the resistance gradually accelerates.

FIG15 shows another possible implementation of the present invention (partial), wherein the cross section of the magnet 350 is approximately trapezoidal, but the four sides of the outer edge are not straight lines, for example, the first side (the top side in the figure) and the second side (the bottom side in the figure) are both convex arcs that bulge outward (as shown in the figure), or they may also be concave arcs that sink inward. Even so, the width of the magnet cross section between the first side and the second side is still gradually widened from the side where the short side is located (the right side in the figure) to the side where the long side is located (the left side in the figure). Similarly, as the magnet 350 moves along the radial direction 332 of the metal disk 330 toward the axis of the metal disk, the axially overlapping portion of the magnet 350 and the metal disk 330 will expand from the narrower side of the magnet cross section to the wider side (as indicated by several imaginary lines on the magnet cross section in the figure), so that the rate of increase in resistance gradually accelerates.

In other possible implementations (not shown), when the resistance is at the minimum value of the adjustable range, that is, when the magnet is at the first end of the adjustment path, when observed along the axial direction of the metal disk, the circular edge of the metal disk does not intersect with the first side and the second side of the magnet cross section. Instead, the side edge (short side) of the outer edge of the magnet connecting the first side and the second side may be a convex arc or other convex shape, and intersects with the circular edge of the metal disk.

In the present invention, a motor or a linear actuator may be used to drive the displacement of the magnet. The user may also control the displacement of the magnet through an electronic operation interface. For example, each time the button marked "+" (representing increased resistance) is pressed, the magnet will move forward one level, and each time the button marked "-" (representing reduced resistance) is pressed, the magnet will move back one level.

FIG. 16 shows a relative relationship between the magnet and the metal disk in the present invention, wherein the outer edge of the metal disk 430 farthest from its rotation axis (center) forms a circular edge 431, and the magnet 450 is located near the outer edge of the metal disk 430, i.e., the circular edge 431. The shape of the cross section of the magnet gradually widens from the side closer to the axis of the metal disk to the side farther from the axis of the metal disk, so that when the magnet 450 crosses the aforementioned circular edge 431 and approaches the axis of the metal disk (for example, in the direction indicated by the arrow in the figure), the area projected by the magnet 450 on the surface of the metal disk 430 increases accordingly, and the applied resistance increases accordingly. That is to say, among the two opposite ends of the adjustment path of the magnet 450 (not shown in the figure), the first end corresponding to the minimum resistance will be farther from the metal disk axis than the second end corresponding to the maximum resistance. The structures shown in Figures 6, 14 and 15 all belong to this type.

FIG. 17 shows another relative relationship between the magnet and the metal disk in the present invention, wherein the disk surface of the metal disk 530 is in the shape of a ring, and may be coaxially fixed to the outer peripheral portion of a flywheel, and can rotate in situ around a rotation axis with the flywheel; the inner edge of the metal disk 530 closest to the aforementioned rotation axis forms a circular edge 531, and the aforementioned circular edge 531 also takes the rotation axis of the metal disk 530 as the center; the magnet 550 is located at The shape of the magnet cross section near the inner edge of the metal disk 530, i.e., the circular edge 531, gradually widens from the side farther from the aforementioned rotation axis (hereinafter referred to as the metal disk axis) to the side closer to the metal disk axis, so that when the magnet 550 crosses the aforementioned circular edge 531 and is farther from the metal disk axis (for example, in the direction indicated by the arrow in the figure), the area of the magnet 550 projected on the surface of the metal disk 530 increases accordingly, and the applied resistance increases accordingly. In other words, among the two opposite ends of the adjustment path (not shown in the figure) of the magnet 550, the first end corresponding to the minimum resistance is closer to the metal disk axis than the second end corresponding to the maximum resistance.

The magnet in the present invention may be only one, located on one axial side of the metal disk, with its inner side of a specific shape facing the corresponding side of the metal disk, which can also cause the rotating metal disk to produce an eddy effect to form a rotational resistance, and the above-mentioned effect of the present invention can also be achieved when the resistance is adjusted.

40: Displacement seat

41: Side panels

42: Positioning pin

50: Magnet

51: Inner side

60: Friction block

61: Friction surface

70: Torsion spring

A3: Swing axis

Claims (10)

A resistance adjustment device for sports equipment, comprising: A frame; A metal plate is pivoted on the frame according to a rotation axis and can be rotated by the movement of the user of the sports equipment; the metal plate has a circular edge with the rotation axis as the center; A displacement seat, provided on the aforementioned frame, which can be displaced according to the control of the aforementioned user; At least one magnet is disposed on the displacement seat, and can move closer to or farther from the rotation axis along an adjustment path across the circular edge of the metal disk as the displacement seat moves, so that the area of the magnet projected on the metal disk along the axial direction of the metal disk increases or decreases; when the magnet is located at the first end of the adjustment path, the projection area is the minimum value of the adjustable range, and when the magnet is located at the second end of the adjustment path, the projection area is the maximum value of the adjustable range; Its characteristics are: The cross section of the magnet on the radial plane of the rotation axis is non-circular, and the outer edge of the magnet cross section includes a first side and a second side opposite to each other, the first side and the second side each having a head end and a tail end, the two head ends are located on the same side and are separated by a convergence distance, the two tail ends are located on the other side and are separated by a divergence distance greater than the convergence distance, and the width of the magnet cross section between the first side and the second side gradually widens from the side where the two head ends are located to the side where the two tail ends are located; when the magnet is located at the first end of the adjustment path, the head ends of the first side and the second side of the magnet cross section are closer to the circular edge of the metal disk than the tail ends. As in claim 1, the resistance adjustment device for sports equipment, wherein the first side and the second side of the magnetic cross section are two non-parallel straight lines. As in claim 1, the resistance adjustment device for sports equipment, wherein when the magnet is located at the first end of the adjustment path, when observed along the axial direction of the metal disk, at least one of the first side and the second side of the cross section of the magnet intersects with the circular edge of the metal disk at one point. As in claim 3, the resistance adjustment device for sports equipment, wherein, in the process of the magnet moving from the first end to the second end along the adjustment path, at least when the projection area increases from the minimum value by 5% to 95% of the difference between the maximum value and the minimum value, the circular edge of the metal disk remains to pass through the first side and the second side of the cross section of the magnet at the same time when observed along the axial direction of the metal disk. As in claim 1, the outer edge of the magnetic cross section further includes a short side, the short side connecting the head ends of the first side and the second side; when the magnet is located at the first end of the adjustment path, when observed along the axial direction of the metal disk, the short side of the magnetic cross section approaches or overlaps with the circular edge of the metal disk. As in claim 1, the outer edge of the magnetic cross section further includes a long side, the long side connecting the tail ends of the first side and the second side; when the magnet is located at the second end of the adjustment path, when observed along the axial direction of the metal disk, the long side of the magnetic cross section approaches or overlaps with the circular edge of the metal disk. As in claim 1, the resistance adjustment device for sports equipment, wherein the displacement seat is pivoted on the frame according to a swing axis parallel to the rotation axis; the relative direction of the first side and the second side of the magnetic cross section corresponds to the relative direction of the magnet and the swing axis. As in claim 7, the resistance adjustment device for sports equipment, wherein the first side of the magnetic cross section is closer to the swing axis than the second side, and the length of the second side is greater than the length of the first side. As in claim 8, the outer edge of the magnetic cross section further comprises a short side and a long side opposite to each other, the short side connects the head ends of the first side and the second side, and the long side connects the tail ends of the first side and the second side; when the magnet is located at the first end of the adjustment path, the short side of the magnetic cross section approaches or overlaps with the circular edge of the metal disk when viewed along the axial direction of the metal disk; when the magnet is located at the second end of the adjustment path, the long side of the magnetic cross section approaches or overlaps with the circular edge of the metal disk when viewed along the axial direction of the metal disk. As in claim 1, the resistance adjustment device for sports equipment, wherein the displacement frame is provided with two aforementioned magnets respectively located on two opposite sides of the aforementioned metal disk in the axial direction, each of the aforementioned magnets has a shape corresponding to the inner side surface of the aforementioned cross section, the aforementioned inner side surface is parallel to the corresponding side surface of the aforementioned metal disk, and the spacing between them remains unchanged; the shapes of the aforementioned two magnets projected on the aforementioned metal disk along the axial direction of the aforementioned metal disk overlap.

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