CN102697611B - Multifunctional stair climbing wheelchair - Google Patents

Abstract

A multi-functional stair-climbing wheelchair, comprising: chair part: a switching mechanism for switching between the roller transmission and the track wheel transmission of the multi-functional stair-climbing wheelchair, and an auxiliary standing mechanism: wherein the track wheels are further Including bracket: supporting wheel: the first gear, the second gear meshed with each other in pairs, and the third gear: the fourth gear formed integrally with the second gear and meshed with each other: formed integrally with the third gear and mutually meshed The meshing fifth gear, and the track gear intermeshing with the fourth gear and the fifth gear external teeth and located outside the support wheel, the maximum angular velocity of the track wheel is The multi-functional stair-climbing wheelchair of the present invention can realize the switching between roller transmission and crawler-wheel transmission, and at the same time use the auxiliary standing mechanism to assist the user to stand, and by controlling the angle of the chair to ensure the level in the process of going up and down stairs, increasing the multi-functional stair climbing Wheelchair safety and comfort.

Description

A kind of multifunctional stair climbing wheelchair

technical field

The invention relates to the technical field of machinery and control, in particular to a multifunctional stair climbing wheelchair.

Background technique

Wheelchairs are an indispensable means of transportation for the elderly and infirm. But, traditional wheelchair just can't cross when encountering hurdle. Among them, going up and down stairs is the biggest obstacle for these people with disabilities. In 200, the country considered installing elevators for these houses in order to solve the problem of going up and down stairs in these houses, but due to various reasons, the plan was shelved.

At present, the way abroad to solve the problem of wheelchair users crossing the stairs is to use the emergency evacuation transport equipment of the building - the stair climber, which is about to temporarily fix the wheelchair on the stair climber, so as to go up and down the stairs. Put it back to the original place after use, and the operation procedure is loaded down with trivial details. Although it can solve the problem of going up and down stairs for wheelchair users, it cannot go up and down stairs in buildings that are not equipped with stair climbing vehicles.

Stair climbing wheelchairs at home and abroad usually use a four-bar mechanism or a planetary gear mechanism to realize going up and down stairs. For the planetary wheel type stair-climbing wheelchair, the structure is simple, and a self-locking mechanism is used to ensure that it does not fall when going up and down stairs. But this stair-climbing wheelchair has poor adaptability to stairs, and cannot meet the needs of users for comfort and reliability.

For the stair-climbing wheelchair with extra track wheels, the way of extra track wheels is adopted when going up and down stairs, which ensures the continuity of the process of going up and down stairs. However, the above-mentioned crawler wheel type stair climbing wheelchair needs to be completed with the help of others when the track wheels are installed each time, and the operation is cumbersome, the structure is heavy, and it is inconvenient to carry, which greatly limits the places where the wheelchair can go up and down stairs.

For the crawler wheel and wheel combination stair climbing wheelchair, the wheelchair uses a four-bar structure to realize the conversion of the wheel and the track wheel by lifting the wheel. However, the stair-climbing wheelchair adopts a four-bar structure and has only one degree of freedom, so it cannot realize high-precision operation output or complete more complicated motion laws.

Therefore aiming at the problems existing in the prior art, the designer of this case relies on the experience of being engaged in this industry for many years, actively researches and improves, so has invented a kind of multifunctional stair-climbing wheelchair.

Contents of the invention

The present invention is aimed at the conventional stair-climbing wheelchairs in the prior art, which have poor adaptability to stairs, cannot meet the needs of users for comfort and reliability, and cannot achieve high-precision operation output or complete more complex movements. The utility model provides a multifunctional stair-climbing wheelchair based on defects such as regularity.

Another purpose of the present invention is to provide a multi-purpose wheelchair for the existing technology, the traditional stair-climbing wheelchair has poor adaptability to stairs, cannot meet the user's needs for comfort and reliability, and the user is uncomfortable when sitting for a long time. The utility model relates to the steps of an auxiliary standing mechanism of a wheelchair for climbing stairs.

In order to solve the above problems, the present invention provides a multifunctional stair climbing wheelchair assistance, comprising: a multifunctional stair climbing wheelchair, including: a chair part, the chair part is used for the user to ride; a switching mechanism, the switching mechanism is set Under the chair part, it is used for switching between the roller transmission and the crawler wheel transmission of the multifunctional stair climbing wheelchair: and an auxiliary standing mechanism, which is arranged on the underside of the chair part and is used for auxiliary use Standing: wherein, the switching mechanism of the multifunctional stair climbing wheelchair is a five-bar mechanism, controlled by 2 linear motors, with 8 movable mechanisms and 11 lower pairs, and its degree of freedom is 2: the multifunctional stair climbing wheelchair The crawler wheel of the wheelchair further includes a bracket: a support wheel, and the support wheel is arranged on the bracket: a first gear, a second gear, and a third gear that are arranged on one side of the support wheel and mesh with each other in pairs: a fourth gear integrally formed with the second gear and intermeshed with each other; a fifth gear integrally formed with the third gear and intermeshed with each other; and external teeth of the fourth gear and the fifth gear intermeshed with each other track gear located outside the support wheel, the maximum angular velocity of the track wheel is In the formula, ω is the angular velocity, m is the mass of the multifunctional stair climbing wheelchair, h is the height of the center of gravity of the multifunctional stair climbing wheelchair, L is the contact length between the track wheel and the ground, J is the moment of inertia of the multifunctional stair climbing wheelchair, and α is the track The angle between the bottom line of the wheel and the ground, r is the angle between the line connecting the center of gravity of the multifunctional stair climbing wheelchair and the front ground point and the track wheel.

Optionally, one end of the switching mechanism is movably connected to the first fixed point on the multifunctional stair climbing wheelchair, and the other end of the switching mechanism is connected to the second fixed point on the multifunctional stair climbing wheelchair. Fixed connection.

Optionally, one end of the first rod of the switching mechanism is movably connected with the first fixed point: the other end of the first rod is movably connected with one end of the second rod of the switching mechanism: the switching mechanism The other end of the second rod is flexibly connected to one end of the first linear motor on the fourth rod: the first bending part of the second rod is axially connected at the end point of the third rod: the first linear motor The other end of the four rods is movably connected with the fifth rod: the other end of the fifth rod is fixedly connected with the third rod: one end of the sixth rod is fixedly arranged on the third rod: the The other end of the sixth rod is flexibly connected to one end of the second linear motor on the seventh rod: the other end of the seventh rod is flexibly connected to one end of the eighth rod: the other end of the eighth rod It is flexibly connected with one end of the rod fixed at the second fixed point: the second bending part of the eighth rod is axially connected at the end point of the third rod.

Optionally, the auxiliary standing mechanism includes a first strut, a second strut, a third strut, and a fourth strut arranged in a parallelogram: the first strut is parallel to the third strut Setting: the second support rod is arranged parallel to the fourth support rod: one end of the second support rod is flexibly connected to a point on the first support rod: the other end of the second support rod is connected to the fourth support rod The endpoint of the third pole is flexibly connected: one end of the fourth pole is flexibly connected to the endpoint on the first pole: the other end of the fourth pole is flexibly connected to the point on the third pole : a fifth pole is arranged between the end of the third pole close to the fourth fixed point and the second pole, and a third linear motor is arranged on the fifth pole: in the A fourth linear motor is arranged on the sixth pole between the third fixed point and the supporting point adjacent to the fourth fixed point.

Optionally, the third pole is in an "L" shape.

In order to achieve another object of the present invention, the present invention provides a method for the auxiliary standing mechanism of the multifunctional stair climbing wheelchair to realize the auxiliary standing function, and the method includes the following steps:

Executing step S1: driven by the third linear motor, and the third linear motor is extended, the connection point between the second pole and the first pole is centered on the other end of the second pole , and move with the length of the second strut as the radius:

Executing Step S2: Since the first pole, the second pole, the third pole and the fourth pole form a parallelogram, the second pole and the fourth pole have the same motion law: The first support rod rotates around the connection point F of the first support rod and the fourth support rod, and the first support rod is always parallel to the third support rod, so that the chair is always supported for use The back of the person:

Step S3 is executed: the third linear motor is driven and extended, thereby realizing the auxiliary standing function of the multifunctional stair-climbing wheelchair.

Optionally, the auxiliary standing mechanism of the multifunctional stair climbing wheelchair further includes when realizing the auxiliary standing function:

Executing step S4: the fourth linear motor is driven, the third linear motor has no elongation movement, and the third support rod rotates clockwise at a certain angle around the fourth fixed point, thereby realizing climbing stairs And the function that the seat can maintain a horizontal state and adjust the center of gravity of the seat when overcoming obstacles.

Optionally, the size of the angle is determined by the angles of stairs and obstacles.

To sum up, the switching mechanism of the multifunctional stair climbing wheelchair of the present invention uses the five-bar mechanism to compensate for the structural error of the four-bar mechanism, so as to realize high-precision motion output or complete more complex motion rules, and thereby realize the transmission of the rollers and The transmission of the track wheels is switched, and at the same time, the auxiliary standing mechanism with a parallelogram structure is used to assist the user to stand, and it can realize the functions of keeping the seat in a horizontal state and adjusting the center of gravity of the seat when climbing stairs and over obstacles.

Description of drawings

Fig. 1 shows the schematic diagram of the three-dimensional structure of the multifunctional stair climbing wheelchair of the present invention:

Fig. 2 shows the principle structural representation of the switching mechanism of the multifunctional stair climbing wheelchair of the present invention:

Fig. 3 shows the structural schematic diagram of the auxiliary standing mechanism of the multifunctional stair climbing wheelchair of the present invention:

Fig. 4 shows the schematic diagram of the adjustment level and the center of gravity of the multifunctional stair climbing wheelchair of the present invention:

Fig. 5 shows the schematic diagram of the initial stage of going upstairs with the second crawler wheel of the multifunctional stair-climbing wheelchair of the present invention:

Fig. 6 shows the schematic diagram during the first track wheel and the second track wheel of the multifunctional stair climbing wheelchair of the present invention:

Fig. 7 shows the schematic diagram after the second crawler wheel of the multifunctional stair climbing wheelchair of the present invention finishes going upstairs:

Fig. 8 shows the structure diagram of the crawler wheel of the multifunctional stair climbing wheelchair of the present invention:

Fig. 9 is a structural schematic diagram showing the multifunctional stair climbing wheelchair of the present invention preparing to climb over obstacles:

Fig. 10 shows the structural representation of the multifunctional stair-climbing wheelchair of the present invention when encountering obstacles and overturning:

Fig. 11 is a structural schematic diagram of the multifunctional stair climbing wheelchair of the present invention about to complete the overturning process when it encounters an obstacle.

Detailed ways

In order to illustrate the technical content, structural features, achieved goals and effects of the present invention in detail, the following will be described in detail in conjunction with the embodiments and accompanying drawings.

Please refer to FIG. 1 , which is a three-dimensional schematic diagram of the multifunctional stair climbing wheelchair of the present invention. The multifunctional stair climbing wheelchair 1 includes a chair part 10, which is used for the user to ride; a switching mechanism 11 between roller transmission and track wheel transmission, and the switching mechanism 11 is arranged on the chair part 10 It is used to switch between the roller transmission and the track wheel transmission of the standing climbing aid mechanism 1, and the auxiliary standing mechanism 12, which is arranged on the lower side of the chair part 10 and is used to assist The user stands.

Please continue to refer to FIG. 1 and refer to FIG. 2 in combination. FIG. 2 is a schematic diagram showing the principle structure of the switching mechanism of the multifunctional stair climbing wheelchair of the present invention. In the present invention, when the multifunctional stair climbing wheelchair 1 is moving on flat ground, the roller transmission mode is adopted; when the multifunctional stair climbing wheelchair 11 is going up and down stairs, the track wheel transmission mode is adopted. Wherein, the switching between the roller transmission mode and the track wheel transmission mode is realized by the lifting control of the track wheel by the switching mechanism 11 . One end of the switching mechanism 11 is movably connected to the first fixed point 13 provided on the multifunctional stair climbing wheelchair 1: the other end of the switching mechanism 11 is connected to the second fixed point on the multifunctional stair climbing wheelchair 1. Point 14 fixed connection.

Please continue to refer to FIG. 2 , the switching mechanism 11 of the multifunctional stair climbing wheelchair 1 of the present invention is a five-bar mechanism, controlled by two linear motors, with 8 movable mechanisms and 11 lower pairs, and its degree of freedom is 2. Specifically, point A at one end of the first rod 110 of the switching mechanism 11 is flexibly connected to the first fixed point 13: point B at the other end of the first rod 110 is connected to the second rod 111 of the switching mechanism 11 One end of the second rod 111 of the switching mechanism 11 is flexibly connected to point D at the other end of the second rod 111 and one end of the first linear motor 113a on the fourth rod 112 is flexibly connected: the first bending part of the second rod 111 1111 is axially connected at point C at the end point of the third rod 114: the other end of the fourth rod 112 is flexibly connected to the fifth rod 115 at point E: the other end of the fifth rod 115 is connected to the The third bar 114 is fixedly connected: one end of the sixth bar 116 is fixedly arranged on the third bar 114; the other end of the sixth bar 116 is connected to the second linear motor 113b on the seventh bar 117. One end is movably connected; the other end of the seventh rod 117 is movably connected to one end of the eighth rod 118: the other end of the eighth rod 118 is movably connected to one end of the rod 119 fixedly arranged on the second fixed point 14 : The second bending portion 1181 of the eighth rod 118 is connected to the end point J of the third rod 114 in an axial manner.

Please continue to refer to FIG. 2 and describe in detail the working principle of the switching mechanism 11 of the multifunctional stair climbing wheelchair 1 of the present invention. When the switching mechanism 11 of the multifunctional stair climbing wheelchair 1 of the present invention is switched between the roller drive and the track wheel drive, the following steps are included:

Step S11 is executed: the first linear motor 113a is driven and extended laterally. At this time, the point B at one end of the second rod 111 that is movably connected with the first linear motor 113a is different from the connection point. The point A of the first fixed point 13 is the center of the circle, and the length of AB is the radius and moves clockwise. : That is, the first rod 110 rotates clockwise around point A. Under the push of the first linear motor 113a, the second rod 111 rotates with the first rod 111 and pushes the end point C of the third rod 114 to move up and down.

Executing step S12: the eighth rod 118 is driven by the second DC motor 113b to rotate around the point K at one end of the rod 119 that is different from the second fixed point 14, and under the push of the eighth rod 118, the The end point J of the third rod 114 moves up and down.

Step S13 is executed: during the up-and-down movement of the end points C and J of the third rod 114 , the lifting of the track wheels is realized, and then the switch between the roller transmission and the track wheel transmission is realized.

Please continue to refer to FIG. 1, and refer to FIG. 3 in combination. FIG. 3 is a schematic diagram of the structural principle of the auxiliary standing mechanism of the multifunctional stair climbing wheelchair of the present invention. The auxiliary standing mechanism 12 of the multifunctional stair climbing wheelchair 1 is fixedly arranged on the wheelchair frame (not shown) of the multifunctional stair climbing wheelchair 1 through the third fixed point 15 and the fourth fixed point 16 . The auxiliary standing mechanism 12 includes a first strut 121 , a second strut 122 , a third strut 123 , and a fourth strut 124 arranged in a parallelogram. Wherein, the first pole 121 is arranged parallel to the third pole 123 ; the second pole 122 is arranged parallel to the fourth pole 124 . The third pole 123 is in an "L" shape. One end of the second pole 122 is movably connected with the point E on the first pole 121 ; the other end of the second pole 122 is movably connected with the end point C of the third pole 123 . One end of the fourth pole 124 is movably connected to the end point F on the first pole 121 ; the other end of the fourth pole 124 is movably connected to the point B on the third pole 123 . A fifth pole 125 is set between the end of the third pole 123 close to the fourth fixed point 16 and the second pole 122, and a third linear motor is arranged on the fifth pole 125 126a. A fourth linear motor 126 b is provided on the sixth support rod 127 between the third fixed point 15 and the supporting point 17 adjacent to the fourth fixed point 16 .

Please continue to refer to FIG. 3 , and describe in detail the working principle of the auxiliary standing mechanism of the multifunctional stair climbing wheelchair of the present invention. The auxiliary standing mechanism 12 of the multifunctional stair climbing wheelchair 1 of the present invention comprises the following steps when realizing the auxiliary standing function:

Step S21 is executed: driven by the third linear motor 126a, and the third linear motor 126a is extended, then the connection point E between the second rod 122 and the first rod 121 is formed by the second rod 122 The other end point C is the center of the circle, and moves with the length of the second pole 122 as the radius. That is, the connection point E between the second pole 122 and the first pole 121 rotates counterclockwise around the other end point of the second pole 122 .

Execute step S22: Since the first strut 121, the second strut 122, the third strut 123, and the fourth strut 124 form a parallelogram, the second strut 122 and the fourth strut 124 have the same laws of motion. The first pole 121 rotates around the connection point F of the first pole 121 and the fourth pole 124, and the first pole 121 is always parallel to the third pole 123, so that The chair portion 10 always supports the user's back.

Step S23 is executed: the third linear motor 126a is driven and stretched, thereby realizing the auxiliary standing function of the multifunctional stair climbing wheelchair 1 .

Please continue to refer to Fig. 1, and refer to Fig. 4, the present invention further includes the following steps in order to realize the function that the seat can maintain a horizontal state and adjust the center of gravity of the seat when climbing stairs and surmounting obstacles:

Execute step S24: the fourth linear motor 126b is driven, at this time, the third linear motor 126a has no elongation movement, and the third support rod 123 rotates clockwise around the fourth fixed point 16 by a certain angle , the size of the angle is determined by the angle of the stairs and obstacles, so as to realize the functions of maintaining the horizontal state of the chair portion 10 and adjusting the center of gravity of the seat when climbing stairs and overcoming obstacles.

Please continue to refer to Fig. 1, and refer to Fig. 5, Fig. 6, and Fig. 7 in combination. Fig. 5 shows a schematic diagram of the second crawler wheel of the multifunctional stair climbing wheelchair of the present invention at the initial stage of going upstairs. Fig. 6 is a schematic diagram of the first track wheel and the second track wheel of the multifunctional stair climbing wheelchair going up stairs according to the present invention. Fig. 7 is a schematic diagram of the second crawler wheel of the multi-functional stair climbing wheelchair of the present invention after it finishes going upstairs. When the multifunctional stair-climbing wheelchair 1 encounters a staircase, the switching mechanism 11 adjusts the inclination of the second crawler wheel 18b until the second crawler wheel 18b is completely attached to the stair surface. Subsequently, the second track wheel 18b and the first track wheel 18a continue to rotate. After the first crawler wheel 18a is smoothly adjusted by the switching mechanism 11 to be in contact with the staircase surface, the second crawler wheel 18b and the first crawler wheel 18a go upstairs at the same time. When the level manned chair (not shown) of the multifunctional stair climbing wheelchair 1 detects by the sensor that the process of going up stairs is over, the second crawler wheel 18b is smoothly adjusted to the level by the switching mechanism 11, and continues Move forward until the first track wheel 18a is also adjusted to the level. That is, the process of going up stairs is completed.

Apparently, the process of going down the stairs is similar to the process of going up the stairs, and will not be explained in detail here.

Please refer to FIG. 8 , which is a structural schematic diagram of the crawler wheels of the multifunctional stair climbing wheelchair of the present invention. The crawler wheels 18a, 18b of the multifunctional stair climbing wheelchair 1 all include a support 180; a support wheel 181, and the support wheel 181 is arranged on the support 180; Engaging first gear 182, second gear 183, and third gear 184; fourth gear 185 integrally formed with said second gear 183 and intermeshed with each other; The fifth gear 186 and the crawler gear 187 which are externally meshed with the fourth gear 185 and the fifth gear 186 and located outside the supporting wheel 181 . Wherein, the track wheel 18a is connected to the track wheel 18b through a bracket 188 . During the movement of the track wheels 18a, 18b, the external motor (not shown) drives the first gear 181 between the second gear 183 and the third gear 184 to rotate: A gear 181 drives the second gear 183 and the third gear 184 to rotate: the second gear 183 and the third gear 184 further drive the fourth gear 185 and the fifth gear 186 to rotate, This drives the rotation of the track gear 187 .

Please continue to refer to FIG. 8 , and refer to FIG. 9 , FIG. 10 , and FIG. 11 in conjunction with FIG. 9 . FIG. 9 is a schematic diagram of the structure of the multifunctional stair-climbing wheelchair according to the present invention and preparing to climb over obstacles. Fig. 10 is a schematic structural view showing the process of the multifunctional stair-climbing wheelchair of the present invention overcoming an obstacle. Fig. 11 is a structural schematic diagram of the multifunctional stair climbing wheelchair of the present invention about to complete the overturning process when it encounters an obstacle.

When the multifunctional stair climbing wheelchair 1 of the present invention encounters a protruding obstacle 2 and is ready to climb over, the track wheel 18b adjusts its state. For example, the multifunctional stair climbing wheelchair 1 climbs over the obstacle 2 at a speed v , L is the contact length between the track wheel 18b and the ground, when the center of gravity is on the left side of the fulcrum O of the obstacle 2, the angle α between the bottom line of the track wheel 18b and the ground will gradually increase with time t

$\mathrm{<span\; class="notranslate">\; sin</span>}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; vt</span>}}$

In the formula: h ₀ is the height of obstacle 2, since h ₀ <<L, so the value of α is small, sinα=α, at this time, the angular velocity ω and angular acceleration a of the multifunctional stair climbing wheelchair are respectively

$\mathrm{<span\; class="notranslate">\; \&omega;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; d\&alpha;</span>}}{\mathrm{<span\; class="notranslate">\; dt</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; vh</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}}{{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; vt</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

$\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; dt</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; v</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}}{{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; vt</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}}$

When the multifunctional stair climbing wheelchair 1 of the present invention climbs over the obstacle 2, the functional stair climbing wheelchair 1 continues to climb up the obstacle 2 at a speed v, and the center of gravity exceeds the fulcrum O. Under the action of gravity and movement speed, The functional stair climbing wheelchair 1 moves in a plane, while rotating around the fulcrum O, and moves forward. At this time, the position of the center of gravity is gradually moving away from the fulcrum O of the obstacle 2, and the moment of the center of gravity to the fulcrum O gradually increases.

Let h be the height of the center of gravity of the functional stair climbing wheelchair 1, and _L1 be the distance from the center of gravity of the functional stair climbing wheelchair 1 to the front grounding point of the track wheel 18b. According to the dynamic differential equation, the variation law of the angular acceleration a of the functional stair climbing wheelchair 1 around the point with α can be obtained.

J×a=mg×cosα×(vt-L ₁ +h×tanα)

In the formula: J is the moment of inertia of the functional stair climbing wheelchair 1.

When the functional stair-climbing wheelchair 1 continues to move forward, the front end of the functional stair-climbing wheelchair 1 first touches the ground, and the functional stair-climbing wheelchair 1 has a greater inertia, so it hits the ground with a greater impact force. , resulting in a strong collision between the functional stair climbing wheelchair 1 and the ground. For example, assuming that the front landing point of the track wheel 18a is point A, its speed is U _A , and the speed after the collision is V _A , according to the impulse theorem, it can be established that the front ground point of the functional stair climbing wheelchair 1 collides with the ground The moment of inertia I of the impact.

${\mathrm{<span\; class="notranslate">\; I</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; I</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.5</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; j</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}$

When the functional stair climbing wheelchair 1 collides with the ground, due to acceleration and inertia, the functional stair climbing wheelchair 1 suddenly turns from rotating around the fulcrum O to turning around the front ground point A, thereby generating an additional inertial angle c.

For example, assuming that the functional stair climbing wheelchair 1 climbs down an obstacle 2 with an inclination angle of g, it is known that the height of the center of gravity of the functional stair climbing wheelchair 1 is h, and the connection between the center of gravity k and the front grounding point A is The angle between line kA and track wheel 18a is r angle. According to the energy conservation principle, the relationship between the additional inertial angle c and the angular velocity at the time of collision can be established:

$\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arcsin</span>}<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; J</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; mg</span>}\sqrt{{\mathrm{<span\; class="notranslate">\; h</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; L</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; )</span>$

From the analysis, it can be known that when the functional stair climbing wheelchair 1 descends the stairs, every step down is equivalent to the functional stair climbing wheelchair 1 crossing an obstacle, and an additional inertial angle is generated at the same time. When a+c+r<90°, the functional stair-climbing wheelchair 1 tilts forward and then falls back to the obstacle 2 due to gravity, causing the obstacle 2 to vibrate and impact the functional stair-climbing wheelchair 1 . That is, when the functional stair climbing wheelchair 1 steps over the next step, two impacts occur. When a+c+r>90°, the center of gravity exceeds the critical state, and the functional stair climbing wheelchair 1 will turn forward around the front ground point A and roll down the stairs. Obviously, to prevent the functional stair climbing wheelchair 1 from rolling down the stairs, it is necessary to control the movement speed of the functional stair climbing wheelchair 1 . Obviously, the greater the angular velocity of the functional stair climbing wheelchair 1, the greater the inertial angle. When the function stair climbing wheelchair 1 was in a critical state, its maximum angular velocity was In the formula, ω is the angular velocity, m is the mass of the multifunctional stair climbing wheelchair, h is the height of the center of gravity of the multifunctional stair climbing wheelchair, L is the contact length between the track wheel and the ground, J is the moment of inertia of the multifunctional stair climbing wheelchair, and α is the track The angle between the bottom line of the wheel and the ground, r is the angle between the line connecting the center of gravity of the multifunctional stair climbing wheelchair and the front ground point and the track wheel.

To sum up, the switching mechanism of the multifunctional stair climbing wheelchair of the present invention uses the five-bar mechanism to compensate for the structural error of the four-bar mechanism, so as to realize high-precision motion output or complete more complex motion rules, and thereby realize the transmission of the rollers and The transmission of the track wheels is switched, and at the same time, the auxiliary standing mechanism with a parallelogram structure is used to assist the user to stand, and in the process of going up and down stairs and over obstacles, by controlling the angle of the chair part, it is ensured that the multifunctional stair climbing wheelchair can move up and down stairs. The process level increases the safety and comfort of the multifunctional stair climbing wheelchair.

Those skilled in the art will appreciate that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, if any modification or variation falls within the scope of protection of the appended claims and their equivalents, the present invention is deemed to cover such modification and variation.

Claims (6)

1. A kind of multifunctional stair climbing wheelchair, is characterized in that, described multifunctional stair climbing wheelchair comprises: a chair portion for a user to sit on; a switching mechanism, the switching mechanism is arranged under the chair part, and is used for switching between the roller transmission and the track wheel transmission of the multifunctional stair climbing wheelchair; and, an auxiliary standing mechanism, the auxiliary standing mechanism is arranged on the lower side of the chair and is used to assist the user to stand; Wherein, the crawler wheels of the multifunctional stair climbing wheelchair further include a bracket; a supporting wheel, the supporting wheel is arranged on the bracket; Two gears, and a third gear; a fourth gear integrally formed with the second gear and intermeshed with each other; a fifth gear integrally formed with the third gear and intermeshed with the fourth gear and the The external teeth of the fifth gear mesh with each other and are located on the track gear outside the support wheel. The maximum angular velocity of the track wheel is In the formula, ω is the angular velocity, m is the mass of the multifunctional stair climbing wheelchair, h is the height of the center of gravity of the multifunctional stair climbing wheelchair, L is the contact length between the track wheel and the ground, J is the moment of inertia of the multifunctional stair climbing wheelchair, and α is the track The angle between the bottom line of the wheel and the ground, r is the angle between the line connecting the center of gravity of the multifunctional stair climbing wheelchair and the front ground point and the track wheel; One end of the switching mechanism is movably connected to a first fixed point provided on the multifunctional stair climbing wheelchair, and the other end of the switching mechanism is fixedly connected to a second fixed point on the multifunctional stair climbing wheelchair; One end of the first rod of the switching mechanism is movably connected with the first fixed point; the other end of the first rod is movably connected with one end of the second rod of the switching mechanism; the other end of the second rod of the switching mechanism is One end is movably connected to one end of the first linear motor on the fourth rod; the first bending part of the second rod is axially connected at the end point of the third rod; the other end of the fourth rod is connected to the fifth rod One end of the fifth rod is connected flexibly; the other end of the fifth rod is fixedly connected with the third rod; one end of the sixth rod is fixedly arranged on the third rod; the other end of the sixth rod is connected with the seventh rod One end of the second linear motor is movably connected; the other end of the seventh rod is movably connected to one end of the eighth rod; the other end of the eighth rod is movably connected to one end of the rod fixed at the second fixed point; The second bent portion of the eighth rod is axially connected to the end point of the third rod. 2. The multifunctional stair-climbing wheelchair as claimed in claim 1, wherein the auxiliary standing mechanism is fixedly arranged on the underside of the chair portion through the third fixed point and the fourth fixed point; The first strut, the second strut, the third strut, and the fourth strut arranged in a parallelogram; the first strut is parallel to the third strut; the second strut is parallel to the third strut; The fourth pole is arranged in parallel; one end of the second pole is flexibly connected to a point on the first pole; the other end of the second pole is flexibly connected to the end point of the third pole; One end of the fourth pole is flexibly connected to the end point on the first pole; the other end of the fourth pole is flexibly connected to the point on the third pole; A fifth pole is arranged between one end of the fourth fixed point and the second pole, and a third linear motor is arranged on the fifth pole; between the third fixed point and the fourth fixed pole A fourth linear motor is arranged on the sixth pole between the support points of the points. 3. The multifunctional stair-climbing wheelchair according to claim 2, wherein the third pole is in an "L" shape. 4. The multifunctional stair climbing wheelchair as claimed in claim 2, wherein the auxiliary standing mechanism of the multifunctional stair climbing wheelchair comprises the following steps when realizing the auxiliary standing function: Executing step S1: driven by the third linear motor, and the third linear motor is extended, then the connection point between the second pole and the first pole is centered on the other end point of the second pole, and the second pole is centered on the second pole. The length of the two struts is the radius motion; Execute step S2: Since the first strut, the second strut, the third strut, and the fourth strut form a parallelogram, the second strut and the fourth strut have the same law of motion; the The first pole rotates around the connection point F of the first pole and the fourth pole, and the first pole is always parallel to the third pole so that the chair always supports the user's back; Step S3 is executed: the third linear motor is driven and extended, thereby realizing the auxiliary standing function of the multifunctional stair-climbing wheelchair. 5. The multifunctional stair climbing wheelchair as claimed in claim 4, wherein the auxiliary standing mechanism of the multifunctional stair climbing wheelchair further comprises when realizing the auxiliary standing function: Execution step S4: driven by the fourth linear motor, the third linear motor has no elongation movement, and the third support rod rotates clockwise at a certain angle around the fourth fixed point, so as to realize the chair part when climbing stairs and over obstacles. It can maintain the horizontal state and adjust the center of gravity of the seat. 6. The multifunctional stair-climbing wheelchair according to claim 5, wherein the angle is determined by the angles of stairs and obstacles.