CN101507871A - Constant-force chest developer - Google Patents

Abstract

The invention provides a constant force tensioner, which has no counterweight, simple structure, light weight, can provide constant tension, and the magnitude of the tension can be adjusted. It mainly includes a frame, a spring, a twisted rope mechanism and an adjustment mechanism. The bearing support positions at both ends of the rope winding shaft of the twisted rope mechanism are installed in the bearing installation holes on the left support plate and the right support plate of the frame through the bearings. The twisted rope mechanism The connecting rope is fixed on the connecting hook at the upper end of the spring, the lower end of the spring is inserted into the positioning hole of the lower connecting plate of the frame and fixed, the bracket of the adjustment mechanism is screwed into the spring, and the screw rod of the adjusting mechanism is screwed into the hole of the lower connecting plate of the frame. The screw hole moves up and down by rotating the screw rod, and the upper part of the screw rod is fixedly installed in the middle hole of the supporting block. The twisting rope mechanism includes a tower-shaped winch rope, a tension rope, a connecting rope and a rope winding shaft, and the adjustment mechanism includes a supporting block and a screw rod. and handwheel.

Description

Constant tension device

technical field

The invention relates to a tension fitness device in the field of body-building and an equal force tension device for force balance, in particular to a constant force tension device.

Background technique

In daily life and work, it is often necessary to provide equipment that can provide constant tension. For example, the tension used to balance the weight of hoisted objects requires a relatively constant force. interest, to achieve better sports training purposes.

The domestic multi-functional fitness equipment with the patent No. CN 95222875.0 includes: a frame part, a seat part, a pulley and a rope part on it, a counterweight part, etc. The main frame composed of rods is equipped with a high-position tension device, a low-position tension device, a chest expansion arm device, a flat push arm action device, a leg flexion and extension arm action device, etc., and an adjustment mechanism that can be lifted and lowered is provided on the seat. The utility model has the advantages of reasonable and novel structural design, simple operation, complete use functions, small size, safety and reliability, and the height, height, and resistance of the seat can be adjusted at will.

The spring balancer with the patent No. 03130614.4 can ensure the working space and improve the working environment, and is suitable for hanging the pneumatic tools with the installation torque detection function. It has: a hose member composed of a first hose and a second hose; a rotating reel for winding the hose member; a support shaft and a rotatable The support member is composed of a cylindrical rotary connector which is supported on the support shaft and rotates together with the rotary reel; In the torque imparting member, the rotary connector has an opening (pipe connector) to which the first hose can be connected to the first air passage, and the second hose can be connected to the second air passage.

The patent No. 200720070497.X is a reversing constant force spring mechanism, including a driven wheel, a retracting wheel and an output wheel. One end of the constant force spring is wrapped around the driven wheel, and the other end of the constant force spring is fixed and rolled back on the retracting wheel. ; The output wheel is fixedly connected with the take-up wheel and is coaxial. The constant force spring is rewound on the take-up wheel, so that the linear motion of the constant force spring becomes a rotary motion. The constant force spring is rewound on a retracting wheel with a relatively large diameter. When the working stroke is long, the torque generated by the constant force spring during the rotation remains constant, and then the torque generated by the constant force spring is converted into Pulling force so that the resulting pulling force also remains constant.

Patent No. CN95222875.0 is that the tension adjustment of the household multifunctional fitness equipment needs to be completed by adding or reducing counterweights, and the equipment is heavy and inconvenient to use.

The patent No. is CN03130614.4. The spring balancer can provide constant tension as the suspension of pneumatic tools, but it needs an air source in the working process.

The rewinding type constant force spring mechanism with the patent No. CN200720070497.X can provide constant tension, but the magnitude of the tension cannot be adjusted.

Contents of the invention

The object of the present invention is to provide a constant force tensioner without counterweight, simple in structure and light in weight, which can provide constant tension and the magnitude of the tension can be adjusted.

In order to achieve the above object, the constant force tensioner of the present invention is characterized in that it includes a frame, a spring, a twisted rope mechanism and an adjustment mechanism;

The bearing support positions at both ends of the rope winding shaft of the twisting rope mechanism are installed in the bearing installation holes on the left support plate and the right support plate of the frame through the bearings, and the connecting rope of the twisting rope mechanism is fixed on the connecting hook at the upper end of the spring. The lower end is inserted into the positioning hole of the lower connecting plate of the frame and fixed, the bracket block of the adjustment mechanism is screwed into the spring, the screw rod of the adjusting mechanism is screwed into the screw hole of the lower connecting plate of the frame, and moves up and down by rotating the screw rod, and the upper part of the screw rod is fixed Installed in the middle hole of the bracket.

The twisted rope mechanism is characterized in that it includes a tower-shaped winch reel, a pull rope, a connecting rope and a rope-winding shaft; the two ends of the rope-winding shaft are bearing support positions, and the tower-shaped winch rope is one end large and the other end small. Helical thread, the bottom diameter of the thread of the tower-shaped winch is proportional to its rotation angle, the tension rope is wound in the thread of the tower-like winch, the tower-like winch is fixed on the winding shaft, and one end of the connecting rope is fixed on the winding rope on the shaft and wound on the rope shaft.

The adjustment mechanism is characterized in that it includes a support block, a screw rod and a hand wheel; the support block is an external spiral trapezoidal thread with a hole in the middle, the pitch of the external spiral trapezoidal thread is equal to the pitch of the spring in a free state, and the bottom of the trapezoidal thread The diameter of the trapezoidal thread is smaller than the inner diameter of the spring, the outer diameter of the trapezoidal thread is larger than the middle diameter of the spring, the thickness of the raised part of the trapezoidal thread is smaller than the distance between two adjacent steel wires in the free state of the spring, and the pitch of the screw rod is equal to the pitch in the free state of the spring. The upper part of the rod is fixedly installed in the middle hole of the supporting block, and the lower part of the screw rod is equipped with a hand wheel.

The spring is a tension spring with a connecting hook at one end and a spring steel wire folded perpendicular to the axis of the spring at the other end, leaving a gap large enough between two adjacent steel wires of the spring for mounting the bracket.

The frame is mainly composed of an upper connection plate, a lower connection plate, a left support plate and a right support plate; the left support plate and the right support plate have bearing mounting holes, and the lower connection plate has a passage hole for a tension rope, a wire The cooperating screw hole of the rod and the spring positioning hole, the pitch of the cooperating screw hole of the screw mandrel are equal to the pitch under the spring free state, and the upper connecting plate, the lower connecting plate, the left supporting plate and the right supporting plate are fixed into a rectangular whole with screws.

Since the pitch of the supporting block and the screw rod is equal to the pitch of the spring in the free state, turning the handwheel can drive the screw rod to rotate in the spring free state, and the rotation of the screw rod drives the rotation of the supporting block, and the rotating of the supporting block will make it in place. at different positions on the spring axis.

The position of the bracket in the axial direction of the spring is different, that is, the number of working turns of the spring is different, which changes the stiffness coefficient of the spring, that is, the position of the bracket in the axial direction of the spring is different to obtain different stiffness coefficients of the spring.

If the stiffness coefficient of the spring is K ₁ , the deflection of the spring is y during operation, and the shaft diameter of the rope around the connecting rope is d, then the tension of the spring is f=K ₁ y, and the deflection of the spring is y The angle that turns around the rope shaft is a=y/d/2, because the thread bottom diameter D of the tower-shaped winch is proportional to its rotation angle, and its proportional coefficient is K ₂ , that is, D=K ₂ a= K ₂ y/d/2, if the pulling force of the tension rope is F, according to the force balance: K ₁ yd/2＝FK ₂ y/d/2/2, that is to say, F＝2K ₁ d ² /k ₂ .

From the relational formula F=2K ₁ d ² /k ₂ , it can be concluded that the pulling force of the tension rope is F only related to the stiffness coefficient of the spring being K ₁ , the shaft diameter d of the winding shaft at the place where the connecting rope is rotated, and the proportional coefficient K ₂ , and after the equipment is manufactured, the shaft diameter d of the rope winding shaft and the proportional coefficient K ₂ are fixed, and the stiffness coefficient of the spring is K ₁ when the position of the bracket in the spring is constant, so, During the elastic deformation of the spring, the tension F of the tension rope is constant.

It can be seen from the relationship F=2K ₁ d ² /k ₂ that in order to obtain constant forces with different values, you can adjust the hand wheel to make the positions of the brackets in the axial direction of the springs different, so as to obtain different stiffness coefficients K ₁ of the springs , resulting in constant forces with different values. When the bracket is at the upper end of the spring, the stiffness coefficient _K1 of the spring is large, and a large constant force can be obtained; when the bracket is at the lower end of the spring, the stiffness coefficient _K1 of the spring is small, and a small constant force can be obtained.

The constant force tensioner of the present invention can provide constant tension, and the tension is adjustable, without counterweight, light in weight, simple in structure, easy in production and processing, and low in cost.

Description of drawings

Fig. 1 is the structural representation of the embodiment of the present invention

Fig. 2 is a cross-sectional schematic diagram of the non-working state when the bracket 4.1 moves to the lower end of the spring 3

Fig. 3 is a structural schematic diagram of the working state when the supporting block 4.1 moves to the lower end of the spring 3

Fig. 4 is a structural schematic diagram of the working state when the supporting block 4.1 moves to the middle of the spring 3

Fig. 5 is a structural schematic diagram of the supporting block 4.1

Figure 1 mark description: frame 1, twisted rope mechanism 2, spring 3, adjustment mechanism 4.

Figure 2 Marking Explanation: Left support plate 1.1, right support plate 1.2, upper connecting plate 1.3, lower connecting plate 1.4, screw 1.5, tower-shaped twisted rope reel 2.1, tension rope 2.2, rope winding shaft 2.3, connecting rope 2.4, supporting block 4.1, screw rod 4.2, hand wheel 4.3, bearing 5.

Detailed ways

Referring to FIG. 1 , the constant force tensioner of the present invention mainly includes a frame 1 , a spring 3 , a twisted rope mechanism 2 and an adjustment mechanism 4 .

Referring to Fig. 2, the bearing support positions at both ends of the rope winding shaft 2.3 of the twisted rope mechanism 2 are installed in the bearing mounting holes on the left support plate 1.1 and the right support plate 1.2 of the frame 1 through the bearing 5, and the connecting rope of the twisted rope mechanism 2 2.4 is fixed on the connecting hook at the upper end of the spring 3, the lower end of the spring 3 is inserted into the positioning hole of the lower connecting plate 1.4 of the frame 1 and fixed, the bracket 4.1 of the adjustment mechanism 4 is screwed into the spring 3, and the screw rod 4.2 of the adjustment mechanism 4 is screwed Enter the screw hole of the connecting plate 1.4 under the frame 1 and move up and down by rotating the screw mandrel, and the upper part of the screw mandrel 4.2 is fixedly installed in the middle hole of the supporting block 4.1.

Twisted rope mechanism 2 comprises tower-shaped twisted rope reel 2.1, tension rope 2.2, connecting rope 2.4 and rope winding shaft 2.3; The two ends of winding rope shaft 2.3 are bearing support positions, and tower-shaped winched rope disk 2.1 is a spiral with one end large and one end small. Thread, the bottom diameter of the thread of the tower-shaped winch reel 2.1 is proportional to its rotation angle, the tension rope 2.2 is wound in the thread of the tower-like winch rope reel 2.1, the tower-like winch rope reel 2.1 is fixedly installed on the rope winding shaft 2.3, and the connecting rope 2.4 One end is fixed on the roping shaft 2.3 and is wound around the roping shaft 2.3.

The adjustment mechanism 4 includes a supporting block 4.1, a screw rod 4.2 and a hand wheel 4.3; as shown in Figure 5, the supporting block 4.1 is an external spiral trapezoidal thread with a hole in the middle, and the pitch of the external spiral trapezoidal thread is equal to that of the spring 3 in a free state , the bottom diameter of the trapezoidal thread is smaller than the inner diameter of the spring 3, the outer diameter of the trapezoidal thread is larger than the middle diameter of the spring 3, the thickness of the raised part of the trapezoidal thread is smaller than the distance between two adjacent steel wires in the free state of the spring 3, the pitch of the screw rod 4.2 is the same as that of the spring 3. The pitches in the free state are equal, the top of the screw mandrel 4.2 is fixedly installed in the middle hole of the bracket 4.1, and the bottom of the screw mandrel 4.2 is equipped with a hand wheel 4.3.

Spring 3 is tension spring, and its one end has connecting hook, and the other end is folded into with spring 3 axis perpendicular with spring 3 steel wires. When designing, leave a gap large enough between two adjacent steel wires of the spring 3 to install the supporting block 4.1.

The frame 1 is mainly composed of an upper connecting plate 1.3, a lower connecting plate 1.4, a left supporting plate 1.1 and a right supporting plate 1.2; the left supporting plate 1.1 and the right supporting plate 1.2 have bearing mounting holes, and the lower connecting plate 1.4 has tension ropes The passing hole of 2.2, the matching screw hole of the screw rod 4.2 and the spring positioning hole, the pitch of the matching screw hole of the screw rod 4.2 is equal to the pitch of the spring 3 in free state, the upper connecting plate 1.3, the lower connecting plate 1.4, and the left supporting plate 1.1 Fix into a rectangular whole with screw 1.5 with right support plate 1.2.

Because the pitch of the supporting block 4.1 and the screw mandrel 4.2 is equal to the pitch under the free state of the spring 3, so in the free state of the spring 3, turning the handwheel 4.3 can drive the screw mandrel 4.2 to rotate, and the screw mandrel 4.2 rotates to drive the supporting block 4.1 to rotate, The rotation of the supporting block 4.1 will make it be in different axial positions of the spring 3 .

The position of the supporting block 4.1 in the axial direction of the spring 3 is different, that is, the number of working turns of the spring 3 is different, which changes the stiffness coefficient of the spring 3, that is, the position of the supporting block 4.1 in the axial direction of the spring 3 is different to obtain the difference of the spring 3 Stiffness coefficient.

If the stiffness coefficient of the spring 3 is K ₁ , during work, the deformation of the spring 3 is y, and the shaft diameter of the winding shaft 2.3 at the connecting rope 2.4 is d, then the tension of the spring 3 is f=K ₁ y, and the spring When the amount of deformation of 3 is y, the angle turned around the rope shaft 2.3 is a=y/d/2, because the thread bottom diameter D of the tower winch 2.1 is proportional to its rotation angle, and its proportional coefficient is K ₂ , That is to say, D=K ₂ a=K ₂ y/d/2, if the pulling force of tension rope 2.2 is F, then according to the balance of force: K ₁ yd/2=FK ₂ y/d/2/2, that is, F=2K ₁ d ² /k ₂ .

From the relational formula F=2K ₁ d ² /k ₂ , it can be concluded that the pulling force F of the tension rope 2.2 is only related to the stiffness coefficient of the spring 3 as K ₁ , and the shaft diameter d and proportional coefficient of the winding shaft 2.3 at the connecting rope 2.4 K ₂ is related, and after the equipment is completed, the shaft diameter d and the proportional coefficient K ₂ of the rope winding shaft 2.3 are fixed, and the stiffness coefficient of the spring 3 is K ₁ when the position of the supporting block 4.1 in the spring 3 is constant. It is also constant, so, during the elastic deformation process of the spring 3, the pulling force F of the tension rope 2.2 is constant.

It can be seen from the relationship F=2K ₁ d ² /k ₂ that in order to obtain constant forces with different values, the position of the supporting block 4.1 in the axial direction of the spring 3 can be different by adjusting the hand wheel 4.3 to obtain different forces of the spring 3 The degree coefficient K ₁ can be used to obtain constant forces of different values. As shown in Figure 4, when the supporting block 4.1 is at the upper end of the spring 3, the stiffness coefficient K of the spring 3 _is large, and a large constant force can be obtained; as shown in Figure 3, when the supporting block 4.1 is at the lower end of the spring 3, the spring The stiffness coefficient K ₁ of 3 is small, and a small constant force can be obtained.

The constant tension device of the present invention can provide constant tension, and the tension is adjustable, without counterweight, light in weight, simple in structure, easy in production and processing, low in cost, convenient in tension adjustment, and can be used as a constant tension fitness device and a lifting object Or tool balance devices, etc.

Claims (5)

1. The constant force tensioner is characterized in that: it includes a frame (1), a spring (3), a twisted rope mechanism (2) and an adjustment mechanism (4); the two ends of the rope winding shaft (2.3) of the twisted rope mechanism (2) The bearing support position is installed in the bearing installation holes on the left support plate (1.1) and the right support plate (1.2) of the frame (1) through the bearing (5), and the connecting rope (2.4) of the twisted rope mechanism (2) is fixed on the The connecting hook on the upper end of the spring (3), the lower end of the spring (3) is inserted into the positioning hole of the lower connecting plate (1.4) of the frame (1) and fixed, and the bracket (4.1) of the adjustment mechanism (4) is screwed into the spring (3 ), the screw rod (4.2) of the adjustment mechanism (4) is screwed into the screw hole of the lower connecting plate (1.4) of the frame (1) and moves up and down by rotating the screw rod, and the upper part of the screw rod (4.2) is fixedly installed on the bracket ( 4.1) In the middle hole. 2. The constant force tensioner according to claim 1, characterized in that: the winch rope mechanism (2) includes a tower winch rope reel (2.1), tension rope (2.2), connecting rope (2.4) and rope winding shaft (2.3); the two ends of the rope winding shaft are bearing support positions, the tower-shaped winch is a helical thread with a large end and a small end, the bottom diameter of the tower-like winch thread is proportional to its rotation angle, and the tension rope (2.2) Wrapped in the thread of the tower-shaped winch reel (2.1), the tower-like winch reel (2.1) is fixedly installed on the rope winding shaft (2.3), and one end of the connecting rope (2.4) is fixed on the rope winding shaft and wound on On the rope shaft (2.3). 3. The constant force tensioner according to claim 1, characterized in that: the adjustment mechanism (4) includes a bracket (4.1), a screw (4.2) and a hand wheel (4.3); the bracket ( 4.1) is an external helical trapezoidal thread with a hole in the middle, the pitch of the external helical trapezoidal thread is equal to the pitch of the spring (3) in a free state, the bottom diameter of the trapezoidal thread is smaller than the inner diameter of the spring (3), and the outer diameter of the trapezoidal thread is larger than that of the spring (3) ) middle diameter, the thickness of the raised part of the trapezoidal thread is less than the distance between two adjacent steel wires in the free state of the spring (3), the pitch of the screw rod (4.2) is equal to the pitch of the free state of the spring (3), and the screw rod ( 4.2) The upper part is fixedly installed in the middle hole of the bracket (4.1), and the lower part of the screw rod (4.2) is equipped with a hand wheel (4.3). 4. The constant force tensioner according to claim 1, characterized in that: the spring (3) is a tension spring, one end of which has a connecting hook, and the other end of the spring steel wire is folded to be perpendicular to the axis of the spring, and the spring (3) There is enough space between two adjacent steel wires to install the bracket (4.1). 5. The constant force tensioner according to claim 1, characterized in that: the frame (1) is mainly composed of an upper connection plate (1.3), a lower connection plate (1.4), a left support plate (1.1) and a right support plate (1.2); the left support plate and the right support plate have bearing installation holes, and the lower connecting plate is provided with the passing hole of the tension rope (2.2), the matching screw hole of the screw mandrel (4.2) and the spring (3 ) positioning hole, the pitch of the cooperating screw hole of the screw rod is equal to the pitch under the spring free state, and the upper connecting plate, the lower connecting plate, the left supporting plate and the right supporting plate are fixed into a rectangular shape with screws (1.5) overall.

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