Foldable multi-stage shock-absorbing rehabilitation wheelchair
By combining cross-folding rods and multi-stage vibration damping devices, the problems of unstable wheelchair folding structures and insufficient vibration damping effects are solved, achieving multi-dimensional vibration damping and structural stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIAXING UNIV
- Filing Date
- 2025-05-08
- Publication Date
- 2026-06-23
AI Technical Summary
The existing wheelchairs have an unstable folding structure and the shock absorption device cannot be adjusted in real time, which cannot effectively alleviate longitudinal and lateral vibrations and poses a safety hazard.
The structure employs a cross-folding rod structure, combined with spring dampers on the front wheels and magnetorheological dampers on the rear wheels, to achieve multi-level and multi-dimensional vibration reduction. The damping force is adjusted by regulating the viscosity of the magnetorheological fluid using an electromagnet, and the structure is stabilized by a folding locking device.
It achieves multi-dimensional vibration reduction for wheelchairs on bumpy roads, improving stability and comfort, ensuring structural stability in the folded state, and reducing safety hazards.
Smart Images
Figure CN224387652U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to wheelchairs, and more particularly to a foldable, multi-stage shock-absorbing rehabilitation wheelchair. Background Technology
[0002] Wheelchair users primarily include people with mobility limitations due to physical conditions; those with permanent or long-term mobility impairments; those with short-term or temporary mobility restrictions; and the elderly. To improve comfort and ease of use, wheelchairs should ideally have folding and shock-absorbing features.
[0003] Regarding the folding function, some wheelchairs use a cross-folding structure, which relies solely on a structural dead point for folding and unfolding and cannot be locked. When the wheelchair shakes during operation, the folding structure may wobble and deform if not locked, posing a safety hazard.
[0004] Vibration damping devices primarily employ spring and electromagnetic vibration damping technologies. The effectiveness of spring-based vibration damping structures depends on the properties of the spring material and its inherent stiffness. While simple in structure and capable of effective vibration reduction to a certain extent, springs suffer from drawbacks such as susceptibility to aging and a narrow damping frequency band due to the nature of the spring material.
[0005] Electromagnetic vibration damping technology utilizes the principle of like poles repelling, adjusting the damping force by changing the magnitude of the current. While this technology can effectively adjust damping according to requirements, it often suffers from the following problems: First, it cannot adjust the damping force in real time, making precise adjustments impossible based on road conditions and damping needs; second, it poses certain safety hazards, as its various current sources make it susceptible to malfunction due to environmental factors such as temperature and humidity; third, the equipment is bulky, requiring power supplies, motors, and numerous electronic control components, increasing the weight of wheelchairs and making it difficult for family members to push; fourth, some of its precision components are prone to failure during long-term use, especially when left unused for extended periods, reducing the reliability and lifespan of the vibration damping system.
[0006] Current shock-absorbing wheelchairs have certain deficiencies in both the direction and dimension of shock absorption. These shock absorbers are installed vertically, which can only alleviate longitudinal vibration. When the electric wheelchair brakes or accelerates suddenly, it cannot avoid lateral lurching and backward tilting caused by inertia, which may cause the user to fall out of the wheelchair or overturn, causing secondary injury to the user.
[0007] For example, patent number 202322363241.X, entitled "A Foldable Electric Wheelchair," features a detachable backrest and seat, folded via an X-shaped folding frame. The drive components include a left motor and a right motor. The left motor is fixed inside the left wheel frame and drives the left rear wheel, while the right motor is fixed inside the right wheel frame and drives the right rear wheel. The left and right motors are staggered, with the left motor controlling the left rear wheel and the right motor controlling the right rear wheel. Compared to traditional single-axis drive structures, this design enables wheelchair folding. Furthermore, the staggered design of the left and right motors avoids interference between them in the folded state. This left-right folding structure, compared to traditional top-bottom folding structures, has advantages such as a smaller footprint when folded.
[0008] Patent No. 201921915534.1, entitled "Vibration-damping chassis structure, vibration-damping device and wheelchair", includes a front wheel assembly, a middle wheel assembly and a rear wheel assembly, as well as a first vibration-damping component for damping the front wheel assembly and a second vibration-damping component for damping the rear wheel assembly; the first vibration-damping component and the second vibration-damping component are gas springs, springs or cylinders.
[0009] Patent No. 202323044018.5, entitled "An Intelligent Wheelchair", includes a lifting mechanism and various control modules, which can realize lifting function.
[0010] Therefore, wheelchairs with different functions have emerged to meet different user needs. Utility Model Content
[0011] Based on the above description, this utility model proposes a foldable multi-level vibration-damping rehabilitation wheelchair. The folding rods are installed on the rear frame in a crisscross pattern. A front wheel vibration damping device is installed on one side of the front wheel, and a rear wheel vibration damping device is installed in the direction of the rear wheel. This realizes multi-level and multi-dimensional vibration damping functions, enabling the rehabilitation wheelchair to move smoothly during travel, improving stability and comfort during travel, while also achieving the folding function.
[0012] The technical solution adopted in this utility model is as follows:
[0013] This foldable, multi-stage shock-absorbing rehabilitation wheelchair is bilaterally symmetrical and includes front wheels, rear wheels, a seat frame, footrests, and a backrest frame. The seat frame and backrest frame are connected, with fabric fixed between them to form the seat. Fabric is also fixed between the backrest frames to form the backrest. Armrest frames are fixed to both the backrest and seat frames, and armrests are mounted on them. A footrest frame is mounted on the front of the seat frame, and footrests are mounted on it. A rear frame and a front frame are bolted to the bottom of the seat frame, and a lower frame is fixed to the bottom of the rear frame. The rear frame, front frame, and lower frame are integrally formed. The front wheel, motor, and front wheel shock absorber are mounted on the front of the front frame. A folding locking device is mounted on one side of the rear frame, and a sliding groove is cut into the rear frame. A retainer is welded to the rear side of the rear frame. An upper support arm and a lower support arm are mounted parallel to each other on the lower frame. One end of the rear wheel shock absorber is mounted on the retainer, and the other end is connected to the upper support arm. Folding rods are installed at an intersection on one side of the front and rear frames, located below the seat frame.
[0014] The front wheel damping device includes a front control arm, a spring damper, and a motor mounting plate. The motor mounting plate is fixed to one side of the front control arm, and a motor is fixed on the motor mounting plate. The drive shaft of the motor is connected to the front flange. The front wheel is fixed to the front flange by bolts, so that the motor drives the front wheel to rotate. A hollow sleeve is fixed to the front end of the front control arm, and a mounting block is welded on the sleeve. The sleeve is fitted onto the drive shaft of the motor. The mounting block is connected to one end of the spring damper by bolts, and the other end of the spring damper is mounted on the front frame by bolts.
[0015] A spring shock absorber includes an upper fixed plate, a lower fixed plate, a first spring, and a spring support rod; one end of the spring support rod is welded to the upper fixed plate, and the other end is welded to the lower fixed plate; the first spring is sleeved on the outside of the spring support rod, and the first spring is located between the upper fixed plate and the lower fixed plate and in contact with both; the lower fixed plate is connected to the mounting block of the front arm by bolts; the upper fixed plate is connected to the front frame.
[0016] The rear wheel damping device includes an upper control arm, a lower control arm, a rear shock absorber, and a rear connecting rod. One end of the upper control arm and the lower control arm are respectively installed parallel to each other on the rear side of the lower frame by bolts, and the other end of the upper control arm and the lower control arm are respectively connected to the rear connecting rod by universal ball bearing rods. A rear wheel mating shaft is fixed on the rear connecting rod, and the rear wheel mating shaft is perpendicular to the rear connecting rod. The rear wheel mating shaft and the rear wheel are mated by a rear flange.
[0017] Bearing sleeves are welded to the upper and lower ends of the rear connecting rod. The bearing sleeves enclose the ball head of the universal ball bearing rod at one end. The other end of the universal ball bearing rod is connected to the upper support arm and the lower support arm respectively through internal threaded bolts.
[0018] The rear shock absorber includes a magnetorheological damper and a second spring, with the second spring sleeved on the outside of the magnetorheological damper; one end of the magnetorheological damper is connected to the fixing device, and the other end is connected to the upper support arm;
[0019] The folding locking device includes a sliding rod, a buckle, a clamping device, and a locking device. The locking device is fixed to the outside of the rear frame and located on one side of the sliding groove. The cross-section of the locking device is U-shaped. The locking device has two through holes. A slider is installed on the sliding rod, and the slider can slide in the sliding groove. One end of the sliding rod is connected to one end of the folding rod by a bolt, and the other end of the sliding rod is connected to the buckle, which has a shaft hole. The buckle can slide in the locking device.
[0020] There are two folding rods, which are crossed by hinge screws. One end is fixed to the slide bar, and the other end is fixed to the rear frame.
[0021] Two locking pins are mounted on the clamping device via fixing pins, and a third spring is fitted on each locking pin. The locking pins and the third springs extend out of the through holes on the clamping device and can cooperate with the shaft holes on the buckle. A blocking ring is fixed to one end of the locking pin, and the diameter of the blocking ring is larger than the diameter of the through hole.
[0022] When the clamp is pulled outward, the locking pin moves away from the buckle, the third spring is compressed, the locking pin disengages from the buckle, and the buckle moves; when the clamp is no longer under force, the third spring returns to its original position, causing the locking pin to move towards the buckle.
[0023] Furthermore, the upper and lower fixing plates are circular, with the same diameter as the first spring; the upper fixing plate is fixed to the U-shaped piece, which is fixed to the front frame by bolts; a support plate is welded onto the lower fixing plate, and the support plate is connected to the mounting block by bolts.
[0024] Furthermore, one end of the buckle is connected to the slide bar by a bolt, while the other end is arc-shaped.
[0025] Furthermore, the magnetorheological damper includes a cylinder, a piston rod, an upper housing, a lower housing, and a piston unit; the upper housing is fixed to one end of the cylinder; the piston unit is installed at one end of the piston rod, and the lower housing is fixed to the other end; a floating piston is installed between the piston unit and the top of the cylinder; the space between the floating piston and the top of the cylinder is filled with inert gas; the space between the floating piston and the bottom of the cylinder is filled with magnetorheological fluid; an electromagnet is installed on the piston unit, and a flow guide hole is opened on the piston unit; a second spring is sleeved on the outside of the cylinder; a fourth spring is installed between the piston unit and the piston rod.
[0026] This invention installs a front wheel damping device at the front wheel and a rear wheel damping device at the rear wheel, achieving multi-level and multi-dimensional damping, effectively mitigating adverse vibrations caused by bumpy road conditions. The multi-dimensional damping not only alleviates longitudinal vibrations but also mitigates lateral diving vibrations caused by inertia from sudden braking or acceleration.
[0027] The rear wheel damping device uses magnetorheology as its working medium. Under the influence of the magnetic field generated by the electric current, the viscosity of the magnetorheological fluid can change significantly within milliseconds, thereby rapidly altering the damping force and achieving a damping effect. The damping force of the magnetorheological damper can be steplessly adjusted according to changes in magnetic field strength, allowing for precise adjustment over a wide range to better adapt to different road conditions and user needs.
[0028] When the wheelchair is folded to the left or right, a folding locking device is used to effectively change the instability caused by the traditional left and right folding wheelchair relying solely on a dead point for limiting and fixing, ensuring the structural sturdiness of the wheelchair when unfolded to the left or right, and improving safety.
[0029] The magnetorheological damping vibration isolator is simple in structure and operation. A wire is arranged inside the piston rod, connecting to an electromagnet for generating current. A guide tube is also installed on the piston, connecting the four chambers formed by the cylinder, piston, and piston rod, serving as a flow guide. The magnitude of the current output by the electromagnet generates a magnetic field. Under the influence of this magnetic field, the magnetorheological fluid undergoes a morphological change due to its chemical properties, generating damping force during piston movement, thus achieving a vibration reduction effect.
[0030] This utility model uses a 12V, 0-5A, battery compatible (EMC) power supply. The power supply is packaged and installed inside the rear frame. The development board and the power supply are integrated into one unit. The wires extending from the power supply pass through the inner hole of the piston rod and are connected to the electromagnet.
[0031] In this invention, the motor drives the wheelchair. When the wheelchair travels on bumpy roads, the front wheels vibrate due to the bumps, causing the front support arm and motor mounting plate to rotate at a certain angle around the fixed shaft. This causes the front wheel damping device to move, compressing the first spring and mitigating longitudinal vibration. The motor mounting plate can move together with the front support arm, ensuring that the motor drive shaft is always properly engaged with the front wheels. Simultaneously, during emergency braking, due to inertia, the wheelchair momentarily lunges forward. This lunging causes the front support arm to rotate upward, activating the front wheel damping device and mitigating lateral vibration.
[0032] The rear wheels move up and down due to bumps. This movement is transmitted to the universal ball bearing via the rear wheel axle, which in turn drives the lower and upper support arms. During the movement of the upper support arm, the upper housing of the magnetorheological damper is fixed to the damper's retainer, and the second spring is compressed, mitigating some of the vibration. Simultaneously, the piston rod moves within the cylinder, energizing the electromagnet and changing the state of the magnetorheological fluid, thereby adjusting the damping force. When the wheelchair needs to be unfolded from its folded state, it stretches left and right, causing the folding rod to rotate around the hinge screw. The folding rod pushes the slider through the slide rail, moving it in the slide rail. When it reaches a certain position, the latch fixed at the other end of the slide rail moves into the folding locking device, pulling the clamp outward. The latch continues to move within the locking device, with one end of the latch being arc-shaped. The latch's shaft hole engages with the locking pin, reducing the clamp's stress. The third spring on the locking pin returns to its original position, and the locking pin, within the latch's shaft hole, secures the latch within the locking device, ensuring the overall stability of the wheelchair structure. When the wheelchair needs to be folded, pull the clamp outward to move the locking pin away from the buckle. The shaft hole on the buckle disengages from the locking pin, compressing the wheelchair left and right, causing the slider to move in the slide groove, thereby moving the folding rod. At the same time, the buckle moves away from the clamp, and the third spring returns to its original position, causing the locking pin and clamp to reset, and the wheelchair folds. Attached Figure Description
[0033] Figure 1 This is a schematic diagram of the structure of this utility model;
[0034] Figure 2 This is a schematic diagram of the front wheel vibration damping device in this utility model;
[0035] Figure 3 This is a schematic diagram of the rear wheel vibration damping device in this utility model;
[0036] Figure 4 This is a schematic diagram of the folding locking device in this utility model;
[0037] Figure 5 This is an exploded view of the locking device and the clamping device in this utility model;
[0038] Figure 6 This is a schematic diagram of the magnetorheological vibration damper in this utility model;
[0039] Figure 7 This is a schematic diagram of the folding locking device and the rear frame in this utility model;
[0040] Figure 8 This is a schematic diagram of the folding locking device and the rear frame in the utility model from another angle. Detailed Implementation
[0041] The technical solution of this utility model is described in detail below. The embodiments of this utility model are for illustrative purposes only, and the scale of the structure is not limited by the embodiments.
[0042] See Figures 1 to 8 The foldable, multi-stage shock-absorbing rehabilitation wheelchair is symmetrical and includes front wheels 1, rear wheels 2, seat frame 3, footrests 4, and backrest frame 5. The seat frame 3 and backrest frame 5 are connected, with fabric fixed between the seat frames 5 to form a seat; fabric is fixed between the backrest frames 5 to form a backrest; armrest frames 6 are fixed to both the backrest frame 5 and the seat frame 3, and armrests 7 are mounted on the armrest frames 6; a footrest frame 8 is mounted on the front of the seat frame, and footrests 4 are mounted on the footrest frame 8; a rear frame 31 and a front frame 32 are bolted to the bottom of the seat frame 3, and a lower frame 33 is fixed to the bottom of the rear frame. The frame 31, front frame 32 and lower frame 33 are integrally formed; the front wheel 1, motor 11 and front wheel damping device 12 are installed on the front side of the front frame 32; a folding locking device 34 is installed on one side of the rear frame 31, a sliding groove 35 is opened on the rear frame 31, and a fixing device 36 is welded to the rear side of the rear frame 31; the upper support arm 331 and the lower support arm 332 are installed parallel to each other on the lower frame 33; one end of the rear wheel damping device 9 is installed on the fixing device 36, and the other end is connected to the upper support arm 331; the folding rod 10 is installed crosswise on one side of the front frame 32 and the rear frame 31, and is located below the seat support 3.
[0043] The front wheel damping device 12 includes a front control arm 121, a spring damper 122, and a motor mounting plate 123. The motor mounting plate 123 is fixed to one side of the front control arm 121, and a motor 11 is fixed on the motor mounting plate 123. The drive shaft of the motor 11 is connected to the front flange 124, and the front wheel 1 is fixed to the front flange 111 by bolts, so that the motor 11 drives the front wheel 1 to rotate.
[0044] A hollow sleeve 125 is fixed to the front end of the front control arm 121. A mounting block 124 is welded onto the sleeve 125, and the mounting block is also fixed to the front end of the front control arm 121. The sleeve 125 is sleeved on the drive shaft of the motor 11. The mounting block 124 is bolted to one end of the spring damper 122, and the other end of the spring damper 122 is bolted to the front frame 32. The spring damper 122 includes an upper fixing plate 126, a lower fixing plate 129, a first spring 128, and a spring. A spring support rod 127 is provided; one end of the spring support rod 127 is welded with a circular upper fixing plate, and the other end is welded with a circular lower fixing plate; a first spring 128 is sleeved on the outside of the spring support rod 127, and the first spring 128 is located between and in contact with the upper fixing plate 126 and the lower fixing plate 129; the lower fixing plate 129 is connected to the mounting block 124 of the front arm by bolts; the upper fixing plate 126 is fixed on the U-shaped part 130, and the U-shaped part 130 is connected to the front frame 32 by bolts. A support plate is welded on the lower fixing plate 126, and the support plate is connected to the mounting block 124 by bolts. The rear wheel damping device 9 includes an upper support arm 91, a lower support arm 92, a rear shock absorber 93, and a rear connecting rod 94. One end of the upper support arm 91 and the lower support arm 92 are respectively bolted parallel to each other and mounted on the rear side of the lower frame 33. The other ends of the upper support arm 91 and the lower support arm 92 are respectively connected to the rear connecting rod 94 via universal ball bearing rods 95. A rear wheel mating shaft 96 is fixed on the rear connecting rod 94. The rear wheel mating shaft 96 is perpendicular to the rear connecting rod 94 and is mated with the rear wheel 2 via a rear flange. Bearing sleeves are welded to the upper and lower ends of the rear connecting rod 94. The bearing sleeves encircle the universal bearing ball head at one end of the universal ball bearing rod. The other end of the universal ball bearing rod is connected to the upper support arm 91 and the lower support arm 92 via internal threaded bolts. The rear shock absorber 93 includes a magnetorheological shock absorber 931 and a second spring 932. The second spring 932 is sleeved on the outside of the magnetorheological shock absorber 931. One end of the magnetorheological shock absorber 931 is connected to the fixing device 36, and the other end is connected to the upper support arm 91.
[0045] The magnetorheological damper 931 includes a cylinder 703, a piston rod 706, an upper housing 712, a lower housing 705, and
[0046] A piston unit 713 is included; an upper housing 712 is fixed to one end of a cylinder 703; the piston unit 713 is mounted on one end of a piston rod 706, and a lower housing 705 is fixed to the other end; a floating piston 711 is installed between the piston unit 713 and the top of the cylinder 703; the space 701 between the floating piston 711 and the top of the cylinder is filled with inert gas; the space between the floating piston 711 and the bottom of the cylinder is filled with magnetorheological fluid 710; an electromagnet 709 is installed on the piston unit 713, and the electromagnet is connected to a wire inside the piston rod; a flow guide hole 702 is opened on the piston unit 713; a second spring 707 is sleeved on the outside of the cylinder. A fourth spring 708 is installed between the piston unit 713 and the piston rod 706 to prevent the piston unit from colliding with the cylinder; a shaft seal 704 is provided between the piston rod and the cylinder. The upper housing is connected to a retainer, and the lower housing is connected to an upper support arm.
[0047] The folding locking device 34 includes a slide bar 341, a buckle 342, a clamping device 343, and a locking device 344. The locking device 344 is fixed to the outside of the rear frame 31 and located on one side of the slide bar 35. The cross-section of the locking device 344 is U-shaped. The locking device 344 has two through holes. A slider 345 is installed on the slide bar 341 and can slide in the slide bar 35. One end of the slide bar 341 is connected to one end of the folding rod 10 by bolts, and the other end of the slide bar 341 is connected to the buckle 342. The buckle 342 has a shaft hole. The buckle 342 can slide in the locking device 344, and one end of the buckle 342 is arc-shaped.
[0048] There are two folding rods 10, which are crossed by hinge screws. One end is fixed to the slide bar 341, and the other end is fixed to the rear frame 31. Two locking pins 347 are installed on the clamping device 343 by fixing pins 346. Each locking pin 347 is fitted with a third spring 348. The locking pins 347 and the third springs 348 extend out of the through holes on the clamping device 344 and can cooperate with the shaft holes on the buckle 342 to fix the buckle 342 to the clamping device 344. A retaining ring 349 is fixed to one end of the locking pin 347. The diameter of the retaining ring 349 is larger than the diameter of the through hole to prevent the locking pin 347 from disengaging from the clamping device 344. When the clamping device 343 is pulled outward, the locking pin 347 moves away from the direction of the buckle 342, the third spring 348 is compressed, the locking pin 347 disengages from the buckle 342, and the buckle 324 can move; when the clamping device is not subjected to external force, the third spring 348 returns to its original state, driving the locking pin 347 and the clamping device to move in the direction of the buckle.
Claims
1. A foldable, multi-stage shock-absorbing rehabilitation wheelchair, symmetrically positioned, comprising front wheels, rear wheels, a seat frame, footrests, and a backrest frame; the seat frame and backrest frame are connected, with fabric fixed between the seat frames to form a seat; fabric is fixed between the backrest frames to form a backrest; armrest frames are fixed to both the backrest frame and the seat frame, and armrests are mounted on the armrest frames; a footrest frame is mounted on the front side of the seat frame, and footrests are mounted on the footrest frame, characterized in that... The rear frame and front frame are bolted to the bottom of the seat support. The lower frame is fixed to the bottom of the rear frame. The rear frame, front frame and lower frame are integrally formed. The front wheel, motor and front wheel damping device are installed on the front side of the front frame. The folding locking device is installed on one side of the rear frame. The rear frame has a sliding groove and a retainer is welded to the rear side of the rear frame. The upper support arm and lower support arm are installed parallel to each other on the lower frame. One end of the rear wheel damping device is installed on the retainer and the other end is connected to the upper support arm. The folding rods are installed in a crisscross pattern on one side of the rear frame and are located below the seat support. The aforementioned front wheel damping device includes a front control arm, a spring damper, and a motor mounting plate. A motor mounting plate is fixed to one side of the front control arm, and a motor is fixed to the motor mounting plate. The motor's drive shaft is connected to the front flange, and the front wheel is bolted to the front flange, enabling the motor to drive the front wheel to rotate. A hollow sleeve is fixed to the front end of the front control arm, and a mounting block is welded to the sleeve. The sleeve is fitted onto the motor's drive shaft, and the mounting block is bolted to one end of the spring damper. The other end of the spring damper is bolted to the front frame. The spring damper includes an upper fixed plate, a lower fixed plate, a first spring, and a spring support rod; one end of the spring support rod is welded to the upper fixed plate, and the other end is welded to the lower fixed plate; the first spring is sleeved on the outside of the spring support rod, and the first spring is located between the upper fixed plate and the lower fixed plate and in contact with both; the lower fixed plate is connected to the mounting block of the front arm by bolts; the upper fixed plate is connected to the front frame. The rear wheel damping device includes an upper support arm, a lower support arm, a rear shock absorber, and a rear connecting rod; one end of the upper support arm and the lower support arm are respectively mounted parallel to each other on the rear side of the lower frame by bolts, and the other end of the upper support arm and the lower support arm are respectively connected to the rear connecting rod by universal ball bearing rods; a rear wheel mating shaft is fixed on the rear connecting rod, the rear wheel mating shaft is perpendicular to the rear connecting rod, and the rear wheel mating shaft is mated with the rear wheel through a rear flange; Bearing sleeves are welded to the upper and lower ends of the rear connecting rod. The bearing sleeves enclose the ball head of the universal ball bearing rod at one end. The other end of the universal ball bearing rod is connected to the upper support arm and the lower support arm respectively through internal threaded bolts. The rear shock absorber includes a magnetorheological damper and a second spring, with the second spring sleeved on the outside of the magnetorheological damper; one end of the magnetorheological damper is connected to the fixing device, and the other end is connected to the upper support arm. The folding locking device includes a sliding rod, a buckle, a clamping device, and a locking device. The locking device is fixed to the outside of the rear frame and located on one side of the sliding groove. The locking device has a U-shaped cross-section and two through holes. A slider is installed on the sliding rod, and the slider can slide in the sliding groove. One end of the sliding rod is connected to one end of the folding rod by a bolt, and the other end of the sliding rod is connected to the buckle, which has a shaft hole. The buckle can slide in the locking device. The folding rod has two parts, which are crossed by hinge screws. One end is fixed to the slide bar, and the other end is fixed to the rear frame. The clamping device is equipped with two locking pins by fixing pins, and each locking pin is fitted with a third spring; the locking pins and the third springs extend out of the through holes on the clamping device and can cooperate with the shaft holes on the buckle; one end of the locking pin is fixed with a blocking ring, the diameter of the blocking ring being larger than the diameter of the through hole. When the clamp is pulled outward, the locking pin moves away from the buckle, the third spring is compressed, the locking pin disengages from the buckle, and the buckle moves; when the clamp is no longer under force, the third spring returns to its original position, causing the locking pin to move towards the buckle.
2. The foldable multi-stage shock-absorbing rehabilitation wheelchair according to claim 1, characterized in that... The upper and lower fixing plates are circular, with the same diameter as the first spring. The upper fixing plate is fixed to the U-shaped piece, which is fixed to the front frame by bolts. A support plate is welded to the lower fixing plate, and the support plate is connected to the mounting block by bolts.
3. The foldable multi-stage shock-absorbing rehabilitation wheelchair according to claim 1, characterized in that... One end of the buckle is connected to the sliding rod by a bolt, and the other end is arc-shaped.
4. The foldable multi-stage shock-absorbing rehabilitation wheelchair according to claim 1, characterized in that... The magnetorheological vibration damper includes a cylinder, a piston rod, an upper housing, a lower housing, and a piston unit; the upper housing is fixed to one end of the cylinder; the piston unit is installed at one end of the piston rod, and the other end is fixed to the lower housing; a floating piston is installed between the piston unit and the top of the cylinder; the space between the floating piston and the top of the cylinder is filled with inert gas; the space between the floating piston and the bottom of the cylinder is filled with magnetorheological fluid; an electromagnet is installed on the piston unit, and a flow guide hole is opened on the piston unit; a second spring is sleeved on the outside of the cylinder; a fourth spring is installed between the piston unit and the piston rod.