CN110547924A

CN110547924A - Wheel-track combined stair-climbing wheelchair

Info

Publication number: CN110547924A
Application number: CN201910865302.8A
Authority: CN
Inventors: 索双富; 刘跃; 时剑文
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2019-09-12
Filing date: 2019-09-12
Publication date: 2019-12-10
Anticipated expiration: 2039-09-12
Also published as: CN110547924B

Abstract

The invention relates to the technical field of wheelchairs, and particularly provides a wheel-track combined stair climbing wheelchair, aiming at solving the problems that the conventional wheel-track combined stair climbing wheelchair realizes the switching of the walking modes through a lifting track mechanism, and the integral gravity center is higher and the walking is unstable when the wheelchair goes up and down stairs. For the purpose, the wheel-track combined stair climbing wheelchair comprises a support, a seat, a track traveling mechanism and a plurality of traveling wheels, wherein the seat, the track traveling mechanism and the plurality of traveling wheels are arranged on the support, the synchronous switching mechanism is arranged on the support, the plurality of traveling wheels are connected with the support through the synchronous switching mechanism, and the synchronous switching mechanism is used for synchronously adjusting the heights of the plurality of traveling wheels relative to the track traveling mechanism. Through such setting, reduced the focus when going upstairs and downstairs, improved the stationarity of going upstairs and downstairs, reduced the risk that takes place to empty.

Description

Wheel-track combined stair-climbing wheelchair

Technical Field

the invention relates to the technical field of wheelchairs, and particularly provides a wheel-track combined stair climbing wheelchair.

Background

the wheel-track combined stair climbing wheelchair comprises a support, wherein a seat, a track mechanism, a flat ground walking wheel and a switching mechanism are arranged on the support. When the vehicle runs on the flat ground, the switching mechanism enables the crawler mechanism to move upwards to be separated from the ground, and meanwhile, the flat ground travelling wheels touch the ground and run on the flat ground through the flat ground travelling wheels; when going upstairs and downstairs, the switching mechanism enables the crawler mechanism to move downwards to touch the ground, meanwhile, the ground-leveling walking wheels are separated from the ground, and the crawler mechanism is used for going upstairs and downstairs.

However, the wheel-track combined stair-climbing wheelchair which realizes the switching between the crawler mechanism and the flat ground travelling wheels by lifting the crawler mechanism needs to be provided with an accommodating space for accommodating the switching mechanism and the crawler mechanism between the flat ground travelling wheels and the bracket. When the wheelchair travels on the flat ground, the crawler mechanism is accommodated in the accommodating space, and the height of the center of gravity of the whole wheel-track combined stair-climbing wheelchair is basically the same as that of the center of gravity of the common wheelchair. When the wheelchair needs to go up and down stairs, the switching mechanism enables the crawler mechanism to move out of the accommodating space and descend below the flat ground walking wheels, the integral gravity center of the wheel-track combined stair climbing wheelchair is improved, and the gravity center is high, so that the wheelchair is easy to cause unstable walking and even topple over.

Accordingly, there is a need in the art for a new solution to the above problems.

Disclosure of Invention

in order to solve the problems in the prior art, namely to solve the problems that the overall gravity center is higher and the walking is unstable when the existing wheel-track combined type stair climbing wheelchair is used for climbing stairs and going up and down the stairs due to the fact that the walking mode is switched by the aid of the lifting track mechanisms, the wheel-track combined type stair climbing wheelchair comprises a support, a seat, a track walking mechanism and a plurality of walking wheels, wherein the seat, the track walking mechanism and the plurality of walking wheels are arranged on the support, the synchronous switching mechanism is arranged on the support, the plurality of walking wheels are connected with the support through the synchronous switching mechanism, and the synchronous switching mechanism is used for synchronously adjusting the heights of the plurality of walking wheels relative to the track walking mechanism.

In the preferred technical scheme of above-mentioned wheel-track combined type stair climbing wheelchair, a plurality of walking wheels include two front wheels and two rear wheels, synchronous switching mechanism includes first swing mechanism, second swing mechanism, connects with pivot mode first swing mechanism with second swing mechanism's link assembly and drive arrangement, first swing mechanism and two the pivot of front wheel is connected, second swing mechanism and two the pivot of rear wheel is connected, drive arrangement is used for the drive first swing mechanism perhaps the swing of second swing mechanism.

In the preferred technical scheme of the wheel-track combined stair climbing wheelchair, the first swing mechanism comprises a first cross rod and two parallel front swing rods fixedly connected with the first cross rod, the first cross rod is pivotally connected with the bracket, and a rotating shaft of the front wheel is connected with one end of each front swing rod; the second swing mechanism comprises a second cross rod and two parallel rear swing rods fixedly connected with the second cross rod, the second cross rod is pivotally connected with the bracket, and a rotating shaft of the rear wheel is connected with one end of each rear swing rod; the connecting rod assembly comprises a first connecting rod, a second connecting rod, a third cross rod and a fourth cross rod, wherein the third cross rod and the fourth cross rod are respectively connected with the first connecting rod and the second connecting rod at two ends; the driving device is used for driving the first cross rod or the second cross rod to rotate.

In the preferable technical scheme of the wheel-track combined stair climbing wheelchair, the first cross bar and the second cross bar are parallel to each other; the end part of the first cross rod is fixedly connected to a position between two ends of the front swing rod, the end part of the second cross rod is fixedly connected to a position between two ends of the rear swing rod, and the distance between the end part of the front swing rod connected with the first connecting rod and the second connecting rod and the first cross rod is equal to the distance between the end part of the rear swing rod connected with the first connecting rod and the second cross rod.

In a preferred embodiment of the wheel-track combined stair-climbing wheelchair, a swing rod is fixed to the second cross bar, the driving device includes a telescopic hydraulic cylinder, one end of the telescopic hydraulic cylinder is pivotally connected to the support, and the other end of the telescopic hydraulic cylinder is pivotally connected to an end of the swing rod so as to drive the swing rod and the second swing mechanism to swing together relative to the support.

In the preferable technical scheme of the wheel-track combined stair climbing wheelchair, the wheelchair further comprises a return spring, one end of the return spring is pivotally connected to the support, the other end of the return spring is pivotally connected to the end part of the swing rod, the return spring is located on one side of the swing rod opposite to the telescopic hydraulic cylinder and always keeps elastic force so as to drive the front swing rod to rotate when the telescopic hydraulic cylinder is decompressed and enable the traveling wheels to contact the ground.

In the preferable technical scheme of the wheel-track combined stair climbing wheelchair, the wheelchair further comprises a self-adaptive posture adjusting mechanism, connecting frames are respectively arranged on two sides of the seat, and the connecting frames are connected with the support through the self-adaptive posture adjusting mechanism so that the seat can still keep a vertical posture when climbing stairs under the action of gravity.

In a preferred technical solution of the above wheel-track combined stair climbing wheelchair, the adaptive posture adjustment mechanism includes two ball pin mechanisms respectively disposed at two sides of the wheelchair, each of the ball pin mechanisms includes a ball socket fixedly connected to the bracket and a ball head fixedly connected to the connecting frame, and the ball head is accommodated in the ball socket so as to maintain the vertical posture of the seat when climbing stairs under the action of gravity.

In the preferable technical scheme of the wheel-track combined stair climbing wheelchair, the self-adaptive posture adjusting mechanism further comprises a posture adjusting buffer mechanism arranged between the connecting frame and the support, and the posture adjusting buffer mechanism is used for reducing the self-adaptive adjusting speed of the seat relative to the support.

In the preferable technical scheme of the wheel-track combined stair climbing wheelchair, the posture adjusting and buffering mechanism is a damping cylinder which is respectively connected with the connecting frame and the support.

The wheelchair comprises a bracket, a seat, a crawler traveling mechanism and a plurality of traveling wheels, wherein the seat, the crawler traveling mechanism and the plurality of traveling wheels are arranged on the bracket, the wheelchair further comprises a synchronous switching mechanism arranged on the bracket, the plurality of traveling wheels are connected with the bracket through the synchronous switching mechanism, and the synchronous switching mechanism is used for synchronously adjusting the heights of the plurality of traveling wheels relative to the crawler traveling mechanism. That is to say, crawler travel mechanism is fixed in on the support of wheelchair, the distance between the seat of crawler travel mechanism and seat is less relatively, synchronous switching mechanism removes a plurality of walking wheels to below crawler travel mechanism when walking on the level land, the holistic focus height of stair wheelchair is climbed to wheel-track combined type this moment is the same basically with ordinary wheelchair, and pack up a plurality of walking wheels through synchronous switching mechanism above crawler travel mechanism's bottom surface when going up and down stairs, go up and down stairs through crawler travel mechanism, the focus of stair wheelchair is climbed to wheel-track combined type this moment reduces, thereby improved the stationarity of going up and down stairs in-process, the risk of falling has been reduced and has taken place. In addition, synchronous switch mechanism synchronous regulation a plurality of walking wheels can make a plurality of walking wheels synchronous movement for crawler travel mechanism's height, makes wheel-track combined type climb the stair wheelchair and keep steadily switching at the switching in-process, avoids a plurality of walking wheels to switch asynchronous and produce the problem that wholly rocks or even topples over, has guaranteed to switch in-process holistic stationarity and has optimized user's use and experience.

drawings

Preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

FIG. 1 is a schematic structural view of a wheel-track combined stair-climbing wheelchair according to an embodiment of the present invention;

FIG. 2 is a schematic view of a synchronous switching mechanism in the wheel-track combined stair-climbing wheelchair according to an embodiment of the present invention;

FIG. 3 is a schematic structural view of a connecting frame and a support frame connected by a self-adaptive posture adjusting mechanism in the wheel-track combined stair-climbing wheelchair according to an embodiment of the present invention;

FIG. 4 is an enlarged view of detail A of FIG. 3;

FIG. 5 is a partial schematic view of a connecting frame of a wheel-track combined stair-climbing wheelchair according to an embodiment of the present invention;

Fig. 6 is a partial schematic view of a bracket in the wheel-track combined stair-climbing wheelchair according to an embodiment of the invention.

List of reference numerals:

11. A lower bracket; 12. an upper bracket; 2. a seat; 21. a handrail; 22. a connecting frame; 31. a front crawler wheel; 32. a rear crawler wheel; 33. a crawler guide wheel; 41. a front wheel; 42. a rear wheel; 511. a first cross bar; 512. a front swing link; 521. a second cross bar; 522. a rear swing rod; 531. a first link; 532. a second link; 533. a third cross bar; 534. a fourth cross bar; 54. a telescopic hydraulic cylinder; 55. a swing lever; 56. a return spring; 6. a self-adaptive attitude adjustment mechanism; 61. a ball head; 62. a ball socket; 63. a first magnetic member; 64. a second magnetic member.

Detailed Description

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only for explaining the technical principle of the present invention, and are not intended to limit the scope of the present invention.

it should be noted that, in the description of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," and "connected" are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrally connected; either directly or indirectly through intervening media, or through the communication between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Referring to fig. 1 and 2, fig. 1 is a schematic structural view of a wheel-track combined stair-climbing wheelchair according to an embodiment of the present invention; fig. 2 is a schematic view of a synchronous switching mechanism in the wheel-track combined stair-climbing wheelchair according to an embodiment of the invention. As shown in fig. 1 and 2, the wheel-track combined stair-climbing wheelchair (hereinafter referred to as a wheelchair) includes a support, a seat 2 disposed on the support, a track traveling mechanism, and four traveling wheels. The support comprises a lower support 11 and an upper support 12 which are fixedly connected, the upper support 12 is connected with the seat 2, two sides of the lower support 11 are respectively provided with a crawler travel mechanism, the crawler travel mechanism comprises a front crawler wheel 31 positioned at the front part of the wheelchair, a rear crawler wheel 32 positioned at the rear part of the wheelchair and a crawler guide wheel 33, and a crawler (not shown in the figure) is supported on the front crawler wheel 31, the rear crawler wheel 32 and the crawler guide wheel 33. The wheelchair further comprises a synchronous switching mechanism arranged on the lower bracket 11, and the four travelling wheels are connected with the lower bracket 11 through the synchronous switching mechanism. The synchronous switching mechanism includes a first swing mechanism located at a front portion of the lower bracket 11, a second swing mechanism located at a rear portion of the lower bracket 11, a link assembly pivotally connecting the first swing mechanism and the second swing mechanism, and a driving device. The four walking wheels comprise two front wheels 41 close to the front part of the lower support 11 and two rear wheels 42 close to the rear part of the lower support 11, the first swing mechanism is connected with the rotating shafts of the two front wheels 41, the second swing mechanism is connected with the rotating shafts of the two rear wheels 42, the driving device drives the second swing mechanism to swing, and the first swing mechanism is driven to swing under the action of the connecting rod assembly. The synchronous switching mechanism synchronously adjusts the heights of the plurality of walking wheels relative to the crawler traveling mechanism, so that the plurality of walking wheels can synchronously move, the wheel-track combined stair climbing wheelchair can be stably switched in the switching process, the problem that the plurality of walking wheels are not synchronous in switching and generate overall shaking or even dumping is avoided, and the overall stability of the switching process is ensured to optimize the use experience of a user.

specifically, the first swing mechanism includes a first cross bar 511 and two parallel front swing bars 512, the first cross bar 511 is pivotally connected to the lower bracket 11, two ends of the first cross bar 511 are respectively and fixedly connected to a position between two end portions of the front swing bar 511, and a lower end of the front swing bar 511 is connected to a rotating shaft of the front wheel 41. The connecting rod assembly comprises a first connecting rod 531 and a second connecting rod 532, and the front ends of the first connecting rod 531 and the second connecting rod 532 are respectively pivoted with the upper ends of the two front swing rods 512; the second swing mechanism comprises a second cross rod 521 and two parallel rear swing rods 522, the second cross rod 521 is pivotally connected with the lower bracket 11, two ends of the second cross rod 521 are respectively and fixedly connected to positions between two ends of the rear swing rods 522, the lower ends of the rear swing rods 522 are connected with a rotating shaft of the rear wheel 42, and the rear ends of the first connecting rod 531 and the second connecting rod 532 are respectively and pivotally connected with the upper ends of the two rear swing rods 522. The first cross bar 511 and the second cross bar 521 are parallel to each other, the distance between the front end of the first connecting rod 531 and the first cross bar 511 is equal to the distance between the rear end of the first connecting rod 531 and the second cross bar 521, and the distance between the front end of the second connecting rod 532 and the first cross bar 511 is equal to the distance between the rear end of the second connecting rod 532 and the second cross bar 521, i.e. a double-rocker mechanism is formed, so that the front wheel 41 and the rear wheel 42 can swing in the same direction. The swing lever 55 is fixed to the second cross bar 521. The driving device comprises a telescopic hydraulic cylinder 54, the end of the cylinder body of the telescopic hydraulic cylinder 54 is connected with the lower frame 11, and the extending end of the piston rod of the telescopic hydraulic cylinder 54 is pivotally connected with the end of the swinging rod 55. The wheelchair further includes a return spring 56, one end of the return spring 56 is pivotally connected to the lower frame 11, the other end of the return spring 56 is pivotally connected to the end of the swing lever 55, and the return spring 56 is located on the opposite side of the swing lever 55 from the telescopic hydraulic cylinder 54 and always maintains an elastic force.

When the telescopic hydraulic cylinder 54 is in a pressure-relieved state, the telescopic rod of the telescopic hydraulic cylinder 54 is in a retracted state due to the elastic force of the return spring 56, at this time, the two front wheels 41 and the two rear wheels 42 are in contact with the ground, the lines of action of the supporting forces of the ground to the front wheels 41 and the rear wheels 42 are respectively deviated from the axes of the first crossbar 511 and the second crossbar 521 and are located at a forward position, the front swing lever 512 has a torque in a clockwise direction (the orientation shown in fig. 1) around the axis of the first crossbar 511, the rear swing lever 522 has a torque in a clockwise direction (the orientation shown in fig. 1) around the axis of the second crossbar 521, and the elastic force of the return spring acts on the swing lever 55 to cause the swing lever 55 to generate a torque in a counterclockwise direction (the orientation shown in fig. 1) around the axis of the second crossbar 521. In a state where the wheelchair is not seated, the piston rod of the telescopic hydraulic cylinder 54 is compressed into the cylinder and generates a supporting force to the swing lever 55, and the supporting force causes the swing lever 55 to generate a torque in the clockwise direction (the orientation shown in fig. 1) about the axis of the second crossbar 521 to the second crossbar 521. The clockwise torque and the counterclockwise torque received by the second crossbar 521 are equal to each other, so that the front wheel and the rear wheel of the wheelchair are in a ground contact state. When the wheelchair is in a state in which the wheelchair is occupied by a person, the torque transmitted to the second crossbar 521 by the force of the ground acting on the front wheels 41 and the rear wheels 42 is increased, the return spring 56 is further compressed, the elastic force of the return spring 56 is increased, the second crossbar 521 is subjected to force balance, and the front wheels 41 and the rear wheels 42 are maintained in a state of contact with the ground. The amount of compression of the return spring by the wheelchair occupant after the wheelchair is seated is much smaller than the amount of compression of the return spring when the swing lever 55 swings and the traveling wheels swing upward and retract.

when the wheelchair runs on the flat ground, the walking wheels can cause the wheelchair to bump up and down due to the unevenness of the ground and the inertia of the walking, and at the moment, the stress of the reset spring can be changed to generate small-amplitude expansion and contraction, so that the vibration reduction effect in the walking process is achieved, and the comfort level of a rider is improved. When the wheelchair needs to go up and down stairs, the operation of the telescopic hydraulic cylinder 54 is controlled, the piston rod of the telescopic hydraulic cylinder 54 extends out of the cylinder body by a set length so as to push the swing rod 55 to swing anticlockwise (in the orientation shown in fig. 1) around the axis of the second cross bar 521, at the moment, the return spring 56 generates a preset compression amount, the front swing rod 512 and the rear swing rod 522 respectively rotate clockwise around the axes of the first cross bar 511 and the second cross bar 521 so as to enable the front wheel 41 and the rear wheel 42 to swing to a position above the bottom surface of the crawler travel mechanism, at the moment, the crawler travel mechanism is in contact with the ground, and the wheelchair goes up or down stairs through the crawler. Through such synchronous switching mechanism, can the height of synchronous adjustment walking wheel for crawler travel mechanism to make a plurality of walking wheels rise in step or descend, make the highly steady change of whole wheelchair among the switching process, avoided the switching in-process to rock and easily produce the problem of empting. In addition, through the height of adjustment walking wheel, can make the whole focus height of wheelchair at the in-process wheelchair of climbing the building lower to the in-process that makes the wheelchair go up and down stairs is more steady, and the security is higher. And foretell switching mechanism only needs to set up a drive arrangement just can drive a plurality of walking wheels simultaneously and go up and down, has guaranteed the synchronism of a plurality of walking wheel adjustments, has reduced drive arrangement's quantity simultaneously, the cost is reduced.

Those skilled in the art will appreciate that the multiple road wheels including two front wheels and two rear wheels is only one specific embodiment, and those skilled in the art can adjust the multiple road wheels as needed to suit the specific application, for example, the multiple road wheels may include one front wheel and two rear wheels, the two rear wheels are connected to two ends of the second cross bar through rear swing links, and the front wheel is connected to the first yaw bar through one front swing link; the plurality of road wheels may include two front wheels and a rear wheel, the two front wheels are connected with both ends of the first cross bar through a front swing link, the rear wheel is connected with the second yaw bar through a rear swing link, and the like. In addition, the swing rod 55 is fixed on the second cross bar 521, the telescopic hydraulic cylinder 54 drives the swing rod 55 to swing and further drives the second cross bar 521 to rotate, and a person skilled in the art may also fix the swing rod 55 on the first cross bar 511 as required, the telescopic hydraulic cylinder 54 drives the swing rod 55 to swing and drive the first cross bar 511 to rotate, the first cross bar 511 drives the front swing rod 512 to swing, and the front swing rod 512 drives the rear swing rod 522 to swing through the first connecting rod 531 and the second connecting rod 532. Furthermore, it is also a preferred embodiment that the driving means is a telescopic hydraulic cylinder, which can be adjusted as required by the person skilled in the art to suit the specific application, e.g. the driving means can be a telescopic cylinder, an electric push rod, etc.

Preferably, with continued reference to fig. 1 and 2, the front ends of the first and second links 531 and 532 are fixedly connected with a third crossbar 533, and the rear ends of the first and second links 531 and 532 are fixedly connected with a fourth crossbar 534. Through the arrangement of the third cross bar 533 and the fourth cross bar 534, the stability of the first link 531 and the second link 532 in driving the front swing link 512 and the rear swing link 522 can be enhanced.

In an alternative embodiment, the front end of the first link 531 is pivotally connected to the upper end of the front swing link 512, the rear end of the first link 531 is pivotally connected to a position between the lower end of the rear swing link 522 and the second crossbar 521, the front end of the second link 532 is pivotally connected to the upper end of the front swing link 512, the rear end of the second link 532 is pivotally connected to a position between the lower end of the rear swing link 522 and the second crossbar 521, the distance between the front end of the first link 531 and the first crossbar 511 is equal to the distance between the rear end of the first link 531 and the second crossbar 521, and the distance between the front end of the second link 532 and the first crossbar 511 is equal to the distance between the rear end of the second link 532 and the second crossbar 521. When the driving device drives the swing lever 55 to swing, the swing directions of the front swing lever 512 and the rear swing lever 522 are opposite to each other. In this way, in the process of switching the ground contact state of the crawler travel mechanism to the ground contact state of the road wheels, the front wheels 41 swing backward and the rear wheels 42 swing forward, so that friction with the ground can be avoided at the moment when the crawler travel mechanism is disengaged from the ground.

In an alternative embodiment, the return spring 56 may not be provided and the telescopic hydraulic cylinder 54 is a bi-directional hydraulic cylinder that maintains the ground engaging wheels in a ground engaging condition by internal pressure of the telescopic hydraulic cylinder 54. When the crawler belt traveling mechanism needs to be switched to be grounded, a piston rod of the telescopic hydraulic cylinder 54 is controlled to extend, the swinging rod 55 is driven to swing, the second cross rod 521 is driven to rotate, the rear swinging rod 522 is driven to swing, and meanwhile, the front swinging rod 512 is driven to swing synchronously under the action of the first connecting rod 531 and the second connecting rod 532, so that the front wheel 41 and the rear wheel 42 are lifted synchronously.

Referring to fig. 3 and 4, fig. 3 is a schematic structural view illustrating a connection frame and a support frame of a wheel-track combined stair-climbing wheelchair according to an embodiment of the present invention are connected by a self-adaptive posture adjustment mechanism; fig. 4 is an enlarged view of a portion a in fig. 3. Preferably, the wheelchair further comprises an adaptive attitude adjustment mechanism 6. Armrests 21 are respectively arranged on two sides of the seat 2, a connecting frame 22 is arranged on the lower portion of each armrest 21, and the connecting frame 22 is connected with the upper support 12 through the self-adaptive posture adjusting mechanism 6, so that the seat 2 can still keep a vertical posture when climbing stairs under the action of gravity. Specifically, as shown in fig. 2 and 3, the adaptive posture adjustment mechanism 6 includes two ball pin mechanisms respectively provided on both sides of the wheelchair, each of the ball pin mechanisms including a ball 61 fixed to the link frame 22 and a socket 62 fixed to the upper frame 12, the ball 61 being accommodated in the socket 62. When the crawler belt runs from the flat ground to the steps of the stairs in the ground contact state of the crawler belt walking mechanism, the lower support 11 and the upper support 12 incline at corresponding angles, and the seat 2 comprises a ball 61 which rotates relative to the ball socket 62 at a certain angle under the action of gravity, so that the seat 2 and the seat on the seat are in a vertical posture. During the travel of the crawler travel mechanism from the flat ground to the stairs, the angles of the lower and upper frames 11 and 12 are changed, and the ball 61 is rotated with respect to the ball socket 62 by the gravity during the process, thereby maintaining the vertical posture of the seat 2 throughout the process.

It will be appreciated by those skilled in the art that the location of the attachment frame 22 at the lower portion of the armrest 21 is merely a preferred embodiment and that those skilled in the art will be able to adjust it as needed to suit the particular application, e.g., the attachment frame 22 may be located above the armrest 21, e.g., 30mm, 40mm, etc. above the armrest 21.

In an alternative embodiment, the adaptive posture adjustment mechanism 6 includes rotating shafts provided on both sides of the seat, the rotating shafts being pivotally connected to the connecting frame 22 and the upper frame 12, respectively, and the seat 2 is maintained in an upright state by swinging with respect to the upper frame 12 by the action of gravity.

With reference to fig. 5 and 6 and with continuing reference to fig. 3 and 4, fig. 5 is a partial schematic view of a connecting frame in a wheel-track composite stair-climbing wheelchair according to an embodiment of the present invention; fig. 6 is a partial schematic view of a bracket in the wheel-track combined stair-climbing wheelchair according to an embodiment of the invention. Preferably, the adaptive attitude adjusting mechanism 6 further includes an attitude adjustment damper mechanism provided between the link frame 22 and the upper bracket 12 for reducing an adaptive adjustment speed of the seat 2 with respect to the upper bracket 12.

Specifically, as shown in fig. 5 and 6, the link frame 22 includes two parallel flat plates provided at the lower portion of each armrest 21, a ball 61 is provided between the two flat plates and accommodated in a ball socket 62, and the seat 2 can swing back and forth with respect to the upper bracket 12 with the swing axis perpendicular to the flat plates. The attitude adjustment damper mechanism includes a plurality of first magnetic members 63, which may be magnets, provided on the surface of the flat plate, the plurality of first magnetic members 63 being distributed around the swing axis, and a plurality of second magnetic members 64, which may be magnets, provided on the side of the upper bracket 1 opposite to the surface of the flat plate on which the first magnetic members 63 are provided, the plurality of second magnetic members 64 being distributed around the swing axis. When the seat 2 does not swing with respect to the upper bracket 12, the plurality of first magnetic members 63 and the plurality of second magnetic members 64 are in one-to-one correspondence and attracted to each other. When the upper bracket 12 is inclined, the connecting frame 22 of the seat 2 swings relative to the upper bracket 12 under the action of gravity, and during the swinging process, part of the first magnetic members 63 are respectively aligned with part of the second magnetic members 64 and mutually attracted, so that resistance for preventing the connecting frame 22 from swinging relative to the upper bracket 12 is generated, the swinging speed is further reduced, and the phenomenon that the seat 2 swings to a vertical posture due to too high swinging speed and then continuously swings forwards to a larger extent is avoided. In addition, when walking on the flat ground, the problem that the seat 2 swings seriously back and forth due to the change of the walking speed can be avoided, and the stability of the seat during walking is improved.

It will be appreciated by those skilled in the art that the first magnetic member may be a magnet and the second magnetic member a magnet is merely one specific embodiment, and those skilled in the art will be able to adjust it as necessary to suit a particular application, for example, the first and second magnetic members may both be electromagnets, or the first magnetic member may be a magnet and the second magnetic member may be an electromagnet, etc. In addition, the posture adjusting and buffering mechanism can also be a damping cylinder which is respectively connected with the connecting frame and the bracket. The damping cylinder comprises a cylinder body and a piston rod sliding in the cylinder body, the end of the cylinder body is in pivot connection with a connecting frame of the seat, the extending end of the piston rod is in pivot connection with the upper support, a damping hole is formed in the damping cylinder body, air enters and exits the cylinder through the damping hole, and therefore certain damping is generated in the process that the piston moves relative to the cylinder body, and the swinging speed of the seat 2 relative to the upper support 12 is further reduced.

So far, the technical solutions of the present invention have been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of the present invention is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the invention, and the technical scheme after the changes or substitutions can fall into the protection scope of the invention.

Claims

1. A wheel-track combined stair climbing wheelchair comprises a bracket, a seat arranged on the bracket, a track walking mechanism and a plurality of walking wheels,

The wheelchair is characterized by further comprising a synchronous switching mechanism arranged on the support, the multiple traveling wheels are connected with the support through the synchronous switching mechanism, and the synchronous switching mechanism is used for synchronously adjusting the heights of the multiple traveling wheels relative to the crawler traveling mechanism.

2. The wheel-track combined stair climbing wheelchair as claimed in claim 1, wherein the plurality of road wheels comprise two front wheels and two rear wheels, the synchronous switching mechanism comprises a first swing mechanism, a second swing mechanism, a connecting rod assembly pivotally connecting the first swing mechanism and the second swing mechanism, and a driving device, the first swing mechanism is connected with the rotating shafts of the two front wheels, the second swing mechanism is connected with the rotating shafts of the two rear wheels, and the driving device is used for driving the first swing mechanism or the second swing mechanism to swing.

3. The wheel-track combined stair climbing wheelchair as claimed in claim 2, wherein the first swing mechanism comprises a first cross bar and two parallel front swing bars fixedly connected with the first cross bar, the first cross bar is pivotally connected with the bracket, and a rotating shaft of the front wheel is connected with one end of the front swing bar;

The second swing mechanism comprises a second cross rod and two parallel rear swing rods fixedly connected with the second cross rod, the second cross rod is pivotally connected with the bracket, and a rotating shaft of the rear wheel is connected with one end of each rear swing rod;

The connecting rod assembly comprises a first connecting rod, a second connecting rod, a third cross rod and a fourth cross rod, wherein the third cross rod and the fourth cross rod are respectively connected with the first connecting rod and the second connecting rod at two ends;

The driving device is used for driving the first cross rod or the second cross rod to rotate.

4. The wheel-track composite stair climbing wheelchair as claimed in claim 3, wherein the first cross bar and the second cross bar are parallel to each other;

The end part of the first cross rod is fixedly connected to a position between two ends of the front swing rod, the end part of the second cross rod is fixedly connected to a position between two ends of the rear swing rod, and the distance between the end part of the front swing rod connected with the first connecting rod and the second connecting rod and the first cross rod is equal to the distance between the end part of the rear swing rod connected with the first connecting rod and the second cross rod.

5. The wheel-track composite stair-climbing wheelchair of claim 4, wherein a swing lever is fixed to the second cross bar, and the driving device comprises a telescopic hydraulic cylinder, one end of the telescopic hydraulic cylinder is pivotally connected to the support, and the other end of the telescopic hydraulic cylinder is pivotally connected to an end of the swing lever so as to drive the swing lever and the second swing mechanism to swing together relative to the support.

6. The wheel-track composite stair climbing wheelchair of claim 5 further comprising a return spring having one end pivotally connected to the bracket and the other end pivotally connected to an end of the swinging rod, the return spring being located on a side of the swinging rod opposite to the telescopic hydraulic cylinder and always maintaining an elastic force so as to drive the front swinging rod to rotate and thus bring the road wheels into contact with the ground when the telescopic hydraulic cylinder is depressurized.

7. The wheel-track combined stair climbing wheelchair as claimed in any one of claims 1 to 6, further comprising an adaptive posture adjustment mechanism, wherein connecting frames are respectively disposed on two sides of the seat, and the connecting frames are connected with the brackets through the adaptive posture adjustment mechanism so that the seat can still maintain a vertical posture when climbing stairs under the action of gravity.

8. The wheel-track composite stair climbing wheelchair as claimed in claim 7, wherein the adaptive posture adjustment mechanism comprises two ball pin mechanisms respectively disposed at both sides of the wheelchair, each of the ball pin mechanisms comprising a ball socket fixedly connected to the bracket and a ball head fixedly connected to the connecting frame, the ball head being received in the ball socket so as to maintain the vertical posture of the seat when climbing stairs under the action of gravity.

9. The wheel-track combined stair-climbing wheelchair of claim 8, wherein the adaptive posture adjustment mechanism further comprises a posture adjustment buffer mechanism disposed between the connecting frame and the support, the posture adjustment buffer mechanism being configured to reduce an adaptive adjustment speed of the seat relative to the support.

10. The wheel-track combined stair climbing wheelchair as claimed in claim 9, wherein the posture adjustment buffer mechanism is a damping cylinder connected to the connecting frame and the support respectively.