Wheelchair assistance

Abstract

The invention relates to the technical field of wheelchairs, and comprises a seat lifting device, which comprises a hydraulic actuator, a hydraulic oil tank and a rocker arm. The hydraulic actuator comprises a hydraulic cylinder assembly, a hydraulic piston rod and a lifting piston rod. The hydraulic cylinder assembly is provided with a cache cylinder body and a lifting cylinder body. The cache cylinder body is connected to the lifting cylinder body and a cache output one-way valve is provided on the connected passage. The hydraulic piston rod is connected to the rocker arm in a transmission manner. The lifting piston rod is connected to the lifting cylinder body in a cooperative manner. The lifting piston rod is connected to the seat cushion body. The hydraulic piston rod is connected to the cache cylinder body in a cooperative manner. The hydraulic piston rod is provided with a hydraulic oil injection pipeline and a hydraulic oil injection one-way valve. The hydraulic oil injection pipeline is connected to the hydraulic oil tank. The present invention can realize the function of assisting users to change from a sitting position to a standing position through a hydraulically controlled mechanical drive method, and does not rely on external power sources such as batteries or motors, thereby significantly reducing the cost of use.

Description

Technical Field

[0001] The present application relates to the technical field of wheelchairs, and in particular to assistive wheelchairs. Background Art

[0002] Wheelchairs are a key assistive device that provides mobility assistance for people with limited mobility. According to the power source, wheelchairs can be divided into manual wheelchairs and electric wheelchairs. Manual wheelchairs have a relatively simple structure and mainly rely on the propulsion of users or assistants, and cannot provide complex functional assistance. Electric wheelchairs are driven by electric motors and controlled by users through controllers, which can provide more functional support.

[0003] In the prior art, most wheelchairs designed to assist in lifting mainly rely on external power sources such as batteries and motors to achieve the assist function. These wheelchairs are usually equipped with electric lifting devices, which are powered by batteries and drive motors to generate power to help users move from a sitting position to a standing position. Electric wheelchairs are expensive and costly for users to use, so they are only suitable for families or users with strong financial capabilities. Summary of the invention

[0004] Based on the above technical problems, the present application provides an assisted wheelchair, which can assist users to change from a sitting position to a standing position through a hydraulically controlled mechanical drive method, without relying on external power sources such as batteries or motors, thereby significantly reducing the cost of use.

[0005] The solution provided by the present application is: a wheelchair that assists in lifting, including a seat frame, a seat cushion body and a seat lifting device, the seat lifting device is transmission-connected to the seat cushion body to drive the seat cushion body to lift and lower relative to the seat frame, the seat lifting device includes a hydraulic actuator, a hydraulic oil tank and a rocker, the hydraulic actuator includes a hydraulic cylinder assembly, a hydraulic piston rod and a lifting piston rod, the hydraulic cylinder assembly is provided with a cache cylinder body and a lifting cylinder body, the cache cylinder body is connected to the lifting cylinder body and a cache output one-way valve is provided on the connected passage, the hydraulic piston rod is transmission-connected to the rocker, the lifting piston rod is cooperatively connected to the lifting cylinder body to extend or retract the lifting cylinder body, the lifting piston rod is connected to the seat cushion The main body is connected to drive the seat cushion body to rise and fall, the hydraulic piston rod is connected with the buffer cylinder body so that it can move back and forth in the buffer cylinder body, the hydraulic piston rod is provided with a hydraulic oil injection pipeline and a hydraulic oil injection check valve, the hydraulic oil injection pipeline is connected to the hydraulic oil tank, when the rocker is shaken back and forth, the hydraulic piston rod moves back and forth in the buffer cylinder body, so as to draw hydraulic oil from the hydraulic oil tank through the hydraulic oil injection pipeline and the hydraulic oil injection check valve and inject it into the buffer cylinder body in one direction, and inject the hydraulic oil in the buffer cylinder body into the lifting cylinder body through the cache output check valve one by one, and the hydraulic oil injected into the lifting cylinder body drives the lifting piston rod to extend out of the lifting cylinder body to drive the seat cushion body to rise.

[0006] The design of the hydraulic cylinder assembly allows the hydraulic piston rod and the lifting piston rod to operate independently and in conjunction. The hydraulic piston rod moves in one cylinder body, while the lifting piston rod moves in another cylinder body. Although the two can be operated independently, they can still achieve linkage action. The hydraulic oil flow path is unidirectional, and the hydraulic piston rod and the buffer cylinder body play a similar role to an air pump. Shaking the rocker back and forth can change the volume of the hydraulic oil in the buffer cylinder body, and the buffer cylinder body forms positive or negative pressure. Under negative pressure, the hydraulic oil in the hydraulic oil tank is injected into the buffer cylinder body in one direction, and under positive pressure, the hydraulic oil in the buffer cylinder body is injected into the lifting cylinder body in one direction. The cache output one-way valve blocks the hydraulic oil injected into the lifting cylinder body from flowing back to the cache cylinder body. By shaking the rocker repeatedly, the hydraulic oil in the lifting cylinder body gradually increases, pushing the lifting piston rod to move out of the lifting cylinder body, driving the seat cushion body to rise, and realizing the assisted lifting action. The assisted lifting wheelchair uses a hydraulically controlled mechanical drive method to achieve the function of assisting users to change from sitting to standing. It does not rely on external power sources such as batteries or motors, which significantly reduces the cost of use.

[0007] As an optional embodiment, the rocker arm includes a fixed rod, a movable rod, an extension drive hydraulic pipeline and a movable rod return spring. The fixed rod is movably connected to the movable rod. The extension drive hydraulic pipeline can hydraulically drive the movable rod to move upward relative to the fixed rod, so that the rocker arm can synchronously extend upward during the lifting process of the seat cushion body. The movable rod return spring is respectively connected to the movable rod and the fixed rod to provide a downward pulling force to the movable rod. The extension drive hydraulic pipeline is connected to the hydraulic cylinder assembly, and the extension drive hydraulic pipeline and the lifting cylinder body are injected with hydraulic oil at the same time.

[0008] The hydraulic driving force of the rocker and the seat body is consistent. The hydraulic driving force refers to the driving force generated by the mechanical movement driven by liquid pressure. The hydraulic oil is injected into the extension drive hydraulic pipeline and the lifting cylinder body at the same time, and the drive of the seat body and the rocker is started at the same time, so that the rocker and the seat body rise in unison. During the rising process of the seat body, the user sitting on it also rises, and the rocker extends upward synchronously. The user does not need to change the position of holding the rocker, and does not need to bend over to shake the rocker to avoid shifting the center of gravity forward and falling forward when bending over.

[0009] As an optional embodiment, the assisted-lifting wheelchair also includes a guide wheel, which includes a wheel body assembly, a fixed seat, a forward drive hydraulic pipeline and a wheel body return spring. The wheel body assembly is movably connected to the fixed seat. The forward drive hydraulic pipeline can hydraulically drive the wheel body assembly to move forward relative to the fixed seat to prevent the user's center of gravity from shifting forward and tipping forward during the lifting of the seat cushion body. The wheel body return spring is respectively connected to the fixed seat and the wheel body assembly to provide elastic force for the wheel body assembly to return to the rearward position. The forward drive hydraulic pipeline is connected to the hydraulic cylinder assembly so that hydraulic oil can be injected into it when the rocker arm is shaken.

[0010] In order to facilitate the user to get up, the seat cushion body does not rise vertically during the lifting process, but moves forward at the same time. Therefore, when the user sits on the seat cushion body and the seat cushion body rises, the center of gravity moves forward relative to the wheelchair. Moving the guide wheel forward can prevent the user from falling forward due to the forward movement of the center. The guide wheel is also driven forward by hydraulic pressure, and the forward hydraulic pipeline is connected to the hydraulic cylinder assembly. The guide wheel can be moved forward by shaking the rocker, which simplifies the structure and does not require an additional power mechanism to drive the guide wheel forward.

[0011] As an optional embodiment, the assisted-lifting wheelchair also includes a linkage brake device, which includes a brake pin, a brake gear and a brake drive hydraulic pipeline. The brake gear is connected to the wheel of the assisted-lifting wheelchair and rotates synchronously. The brake drive hydraulic pipeline can hydraulically drive the brake pin to move and clamp the brake gear to brake the wheel. The brake drive hydraulic pipeline is connected to the hydraulic cylinder assembly so that hydraulic oil can be injected into it when the rocker arm is shaken.

[0012] The conventional brakes of wheelchairs are at the wheels, which can be reached by hands when sitting in the wheelchair. Generally speaking, the car should be braked first, and then the seat cushion body should be raised to prevent the car from slipping and causing danger. However, the user may forget to brake first. After the seat cushion is raised a little, even if it is found that the brakes were not applied first, it is difficult to operate the brakes because it is necessary to bend down to reach it. Firstly, it may not be reached, and secondly, bending down will cause the center of gravity of the body to move forward, and there is a risk of tipping forward. An additional linkage brake device is set up, and the brakes will be completed when the rocker is shaken to raise the seat cushion body. Even if the user forgets to brake before raising the seat cushion, there will be no risk of slipping, which improves safety.

[0013] As an optional embodiment, the hydraulic cylinder assembly also includes a diverter cylinder body, the diverter cylinder body includes a diverter piston, a pre-operation hydraulic pipeline and a seat cushion hydraulic pipeline, the buffer cylinder body is connected with the diverter cylinder body, the hydraulic oil of the buffer cylinder body is unidirectionally injected into the diverter cylinder body via the buffer output one-way valve, the seat cushion hydraulic pipeline is connected with the lifting cylinder body, the diverter piston is arranged in the diverter cylinder body, and the diverter piston is pushed to move by the hydraulic oil unidirectionally injected into the diverter cylinder body, the inlet of the pre-operation hydraulic pipeline is exposed first, and the hydraulic oil of the diverter cylinder body is injected into the pre-operation hydraulic pipeline to drive the pre-operation before the seat cushion body is lifted, and thereafter the hydraulic oil that continues to be injected into the diverter cylinder body pushes the diverter piston to continue to move to expose the inlet of the seat cushion hydraulic pipeline, the hydraulic oil of the diverter cylinder body is injected into the seat cushion hydraulic pipeline and finally injected into the lifting cylinder body to lift the seat cushion body.

[0014] A diverter piston and a pre-operation hydraulic pipeline are arranged in the diverter cylinder body. Hydraulic oil injected into the pre-operation hydraulic pipeline can drive the completion of the preset control action, that is, some necessary pre-operations are completed before the seat cushion body is raised, such as braking, moving the guide wheels forward, etc. The setting of the diverter cylinder body allows the whole hydraulic control system to integrate more functions, thereby improving the rationality and safety of the use of the assisted-lift wheelchair.

[0015] As an optional embodiment, the hydraulic cylinder assembly also includes a hydraulic oil release pipeline, which is connected to the lifting cylinder body. The hydraulic piston rod is cooperatively connected to the hydraulic oil release pipeline to open or block the communication path between the hydraulic oil release pipeline and the lifting cylinder body. When the hydraulic piston rod is locked in a preset position, the communication path between the hydraulic oil release pipeline and the lifting cylinder body is opened, and the hydraulic oil of the lifting cylinder body is released through the hydraulic oil release pipeline to drive the seat cushion body to descend.

[0016] The passage between the hydraulic oil release pipeline and the lifting cylinder body is in a normally closed state. When the hydraulic piston rod is locked in a preset position, the passage between the hydraulic oil release pipeline and the lifting cylinder body is triggered to open, the hydraulic oil of the lifting cylinder body is discharged through the hydraulic oil release pipeline, the lifting piston rod retracts into the lifting cylinder body, and the seat cushion body descends.

[0017] As an optional embodiment, the hydraulic piston rod includes a movable connecting rod, which is provided with multiple oil release holes. When the hydraulic piston rod is locked in a preset position, the hydraulic oil release pipeline is aligned with the oil release hole to communicate with the lifting cylinder body through the oil release hole.

[0018] The movable connecting rod and the hydraulic piston rod can be an integrated structure. The hydraulic oil release pipeline is connected to the lifting cylinder body only when the oil release through hole of the movable connecting rod is aligned with the hydraulic oil release pipeline. When the oil release through hole of the movable connecting rod is in other positions, the connecting passage between the hydraulic oil release pipeline and the lifting cylinder body is closed. The movable connecting rod can move back and forth with the hydraulic piston rod. When the movable connecting rod is in an active state, the oil release through hole is not static in the same position. The movable connecting rod isolates the connecting passage between the hydraulic oil release pipeline and the lifting cylinder body. When the hydraulic piston rod is locked in a preset position, the oil release through hole of the movable connecting rod is aligned with the hydraulic oil release pipeline. One end of the oil release through hole is connected to the hydraulic oil release pipeline, and the other end of the oil release through hole is connected to the lifting cylinder body. The passage between the hydraulic oil release pipeline and the lifting cylinder body is connected.

[0019] As an optional embodiment, the lifting piston rod includes a one-way stop rack and a locking pin, and the locking pin and the one-way stop rack are cooperatively connected. The locking pin can be inserted into the one-way stop rack to limit the lifting piston rod from retracting into the lifting cylinder body when the lifting cylinder body is injected with hydraulic oil.

[0020] The one-way stop rack and the locking pin limit the movement direction of the lifting piston rod in the lifting cylinder body, allowing the lifting piston rod to gradually move out of the lifting cylinder body in one direction, and limiting the lifting piston rod from retracting into the lifting cylinder body, so that the seat body can be gradually and stably raised. When the user's center of gravity is unstable and he sits back heavily on the seat body again, the impact of instantaneous impact on the hydraulic control pipeline can be avoided.

[0021] As an optional embodiment, the hydraulic piston rod includes a linkage connection piece and a latch spring. The latch spring is connected to the locking latch to push the locking latch into the one-way stop rack. The linkage connection piece is respectively connected to the hydraulic piston rod and the locking latch so that when the hydraulic piston rod is locked in a preset position, the locking latch is pulled to unlock the lifting piston rod.

[0022] Through the linkage connector and the locking latch, the hydraulic piston rod can be linked to limit the moving direction of the lifting piston rod. When the rocker arm is shaken, there is no force applied between the hydraulic piston rod and the linkage connector. The locking latch is affected by the latch spring and is stuck in the one-way stop rack, which limits the lifting piston rod to only extend out of the lifting cylinder body and cannot retreat. The hydraulic piston rod is locked in a preset position. The hydraulic piston rod pulls the locking latch through the linkage connector, pulling the locking latch out of the one-way stop rack, thereby unlocking the lifting piston rod in a linkage manner, so that the lifting piston rod is no longer restricted in the direction of retracting the lifting piston rod into the lifting cylinder body. The drive structure of the locking latch is simplified, and no additional drive method is required, which helps to reduce costs.

[0023] As an optional embodiment, the hydraulic cylinder assembly includes a piston rod locking mechanism, which is cooperatively connected with the hydraulic piston rod to lock the hydraulic piston rod in a preset position. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the three-dimensional structure of the assisted-lift wheelchair according to an embodiment of the present application;

[0025] Figure 2 A schematic cross-sectional view of the assisted-lifting wheelchair according to an embodiment of the present application;

[0026] Figure 3 for Figure 2 A is an enlarged structural diagram;

[0027] Figure 4 for Figure 2 The enlarged structural diagram at B in FIG.

[0028] Figure 5 for Figure 2 The enlarged structural diagram at C in FIG.

[0029] Figure 6 It is a schematic diagram of the three-dimensional structure of the hydraulic actuator of the embodiment of the present application;

[0030] Figure 7 It is a cross-sectional structural schematic diagram of the hydraulic actuator of an embodiment of the present application;

[0031] Figure 8 A schematic diagram of the three-dimensional structure of the linkage brake device according to an embodiment of the present application;

[0032] Fig. 9 It is a schematic cross-sectional structural diagram of a rocker according to an embodiment of the present application;

[0033] Fig.10 This is a schematic diagram of the cross-sectional structure of the guide wheel of an embodiment of the present application.

[0034] Description of the accompanying drawings: seat frame 1, seat cushion body 2, seat lifting device 3, hydraulic cylinder assembly 31, buffer cylinder body 311, lifting cylinder body 312, diverter cylinder body 313, diverter piston 314, pre-operation hydraulic pipeline 315, seat cushion hydraulic pipeline 316, hydraulic oil release pipeline 317, first branch 317a, second branch 317b, third branch 317c, hydraulic piston rod 32, hydraulic oil injection pipeline 321, hydraulic oil injection check valve 322, lifting piston rod 33, one-way stop rack 3 31, locking pin 332, linkage connecting piece 34, pin spring 35, cache output one-way valve 36, piston rod locking mechanism 37, movable connecting rod 38, oil release hole 381, hydraulic oil tank 4, rocker 5, fixed rod 51, movable rod 52, extension drive hydraulic pipeline 53, movable rod return spring 54, guide wheel 6, wheel body assembly 61, fixed seat 62, forward drive hydraulic pipeline 63, wheel body return spring 64, linkage brake device 7, brake pin 71, brake gear 72, brake drive hydraulic pipeline 73. DETAILED DESCRIPTION

[0035] The present invention is described in detail below in conjunction with specific embodiments.

[0036] Figure 1 and Figure 2 This is a schematic diagram of the structure of the wheelchair in the embodiment of the present application. Figure 1-2 As shown, the assisted-lifting wheelchair provided in the embodiment of the present application comprises a seat frame 1, a seat cushion body 2 and a seat lifting device 3. The seat lifting device 3 is connected to the seat cushion body 2 in a transmission manner to drive the seat cushion body 2 to rise and fall relative to the seat frame 1. The seat lifting device 3 can be connected to the seat cushion body 2 through a connecting rod mechanism or directly connected to the seat cushion body 2. The seat cushion body 2 is driven to rise by the seat lifting device 3 to help the user change from a sitting position to a standing position.

[0037] like Figure 2As shown in the cross-sectional structural diagram of the power-assisted wheelchair, the power-assisted wheelchair of the embodiment of the present application realizes the function of assisting the user to change from a sitting position to a standing position through a hydraulically controlled mechanical drive method, does not rely on external power sources such as batteries or motors, and significantly reduces the cost of use. The seat lifting device 3 includes a hydraulic actuator, a hydraulic oil tank 4 and a rocker 5. The hydraulic oil tank 4 can be arranged below the seat cushion body 2. The hydraulic actuator can be arranged between the seat cushion body 2 and the hydraulic oil tank 4. The hydraulic actuator includes a hydraulic cylinder assembly 31, a hydraulic piston rod 32 and a lifting piston rod 33. The hydraulic piston rod 32 and the lifting piston rod 33 are respectively arranged at both ends of the hydraulic cylinder assembly 31. Figure 6 and Figure 7 The structural schematic diagram of the hydraulic actuator shown in the figure, the hydraulic cylinder assembly 31 is provided with a cache cylinder body 311 and a lifting cylinder body 312, the cache cylinder body 311 is connected to the lifting cylinder body 312 and a cache output one-way valve 36 is provided on the connected passage. The cache output one-way valve 36 of the embodiment of the present application is arranged at the output port of the cache cylinder body 311. In other embodiments, the cache output one-way valve 36 is also arranged at the input port of the lifting cylinder body 312. Figure 1 and Figure 2 It is shown that the hydraulic piston rod 32 is connected to the rocker 5 in transmission. The rocker 5 is provided with two groups. The two groups of rockers 5 are connected by a connecting rod and a transmission gear is arranged on the connecting rod. When the rocker is shaken back and forth, the hydraulic piston rod 32 is driven to move back and forth. Figure 2-5As shown, the lifting piston rod 33 is connected with the lifting cylinder body 312 to extend or retract the lifting cylinder body 312, and the lifting piston rod 33 is connected with the seat cushion body 2 to drive the seat cushion body 2 to rise and fall. When the lifting piston rod 33 extends from the lifting cylinder body 312, the seat cushion body 2 is driven to rise, and when the lifting piston rod 33 retracts the lifting cylinder body 312, the seat cushion body 2 is driven to fall. The hydraulic piston rod 32 is connected with the buffer cylinder body 311 to be able to reciprocate in the buffer cylinder body 311. The structure of the hydraulic piston rod 32 and the lifting piston rod 33 in the cylinder body can be a combination of a piston body, a piston ring and a seal to prevent the hydraulic oil from leaking from both sides of the piston rod. The hydraulic piston rod 32 is provided with a hydraulic oil injection pipeline 321 and a hydraulic oil injection check valve 322. In the embodiment of the present application, the hydraulic oil injection check valve 322 is arranged at the output port of the hydraulic oil injection pipeline 321, and the hydraulic oil injection pipeline 321 is connected to the hydraulic oil tank 4. The swing amplitude of the rocker 5 corresponds to the amount of hydraulic oil injected. When the rocker 5 is shaken back and forth, the hydraulic piston rod 32 reciprocates in the buffer cylinder body 311, so as to successively draw hydraulic oil from the hydraulic oil tank 4 through the hydraulic oil injection pipeline 321 and the hydraulic oil injection check valve 322 and inject it into the buffer cylinder body 311 in one direction, and successively inject the hydraulic oil in the buffer cylinder body 311 into the lifting cylinder body 312 through the buffer output check valve 36. The hydraulic oil injected into the lifting cylinder body 312 drives the lifting piston rod 33 to extend out of the lifting cylinder body 312 to drive the seat cushion body 2 to rise. When the hydraulic piston rod 32 extends outward from the buffer cylinder body 311 in conjunction with the rocker arm 5, the hydraulic oil is injected into the buffer cylinder body 311 through the hydraulic oil injection pipeline 321 and the hydraulic oil injection check valve 322. The hydraulic oil can be stored in the buffer cylinder body 311 first. When the hydraulic piston rod 32 pushes the buffer cylinder body 311 inwardly in conjunction with the rocker arm 5, the hydraulic oil in the buffer cylinder body 311 can be injected into the lifting cylinder body 312 through the cache output check valve 36 under the thrust.

[0038] The design of the hydraulic cylinder assembly 31 allows the hydraulic piston rod 32 and the lifting piston rod 33 to operate independently and in conjunction. The hydraulic piston rod 32 moves in one cylinder body, while the lifting piston rod 33 moves in another cylinder body. Although the two can be operated independently, they can still achieve a linkage action. The hydraulic oil flow path is unidirectional, and the hydraulic piston rod 32 and the buffer cylinder body 311 play a similar role as an air pump. Shaking the rocker 5 back and forth can change the volume of the hydraulic oil in the buffer cylinder body 311, and the buffer cylinder body 311 forms a positive pressure or a negative pressure. Under the negative pressure state, the hydraulic oil of the hydraulic oil tank 4 is unidirectionally injected into the buffer cylinder body 311, and under the positive pressure state, the hydraulic oil of the buffer cylinder body 311 is unidirectionally injected into the lifting cylinder body 312. The cache output one-way valve 36 blocks the hydraulic oil injected into the lifting cylinder body 312 from flowing back to the cache cylinder body 311. By shaking the rocker 5 multiple times, the hydraulic oil injected into the lifting cylinder body 312 gradually increases, pushing the lifting piston rod 33 to move out of the lifting cylinder body 312, driving the seat cushion body 2 to rise, thereby realizing the assisting action.

[0039] In some usage scenarios, when shaking the joystick 5 back and forth, the user holds the joystick 5, and the user changes from a sitting position to a standing position. The user's center of gravity moves diagonally upward and forward, and the user needs to adjust the height of holding the joystick 5. For example, if the joystick 5 is too short, the user needs to bend down to shake the joystick 5. If the force is not applied properly, the center of gravity may be unstable. Figure 2 and Fig. 9 As shown, the lifting wheelchair of the embodiment of the present application is integrated with the extension and retraction function of the rocker 5, and the rocker 5 includes a fixed rod 51, a movable rod 52, an extension drive hydraulic pipeline 53 and a return spring of the movable rod 52. The fixed rod 51 is movably connected with the movable rod 52. The extension drive hydraulic pipeline 53 can hydraulically drive the movable rod 52 to move upward relative to the fixed rod 51, so that the rocker 5 is synchronously extended upward during the lifting process of the seat cushion body 2. The return spring of the movable rod 52 is respectively connected to the movable rod 52 and the fixed rod 51 to provide a downward pulling force to the movable rod 52. The extension drive hydraulic pipeline 53 is connected with the hydraulic cylinder assembly 31, and the extension drive hydraulic pipeline 53 and the lifting cylinder body 312 are injected with hydraulic oil at the same time. The hydraulic oil injected into the extension drive hydraulic pipeline 53 pushes the movable rod 52 to move upward relative to the fixed rod 51, and the hydraulic oil injected into the lifting cylinder body 312 pushes the lifting piston rod 33 to extend out of the lifting cylinder body 312, so that the rocker 5 is synchronously extended upward during the lifting process of the seat cushion body 2. In an optional embodiment, a flow dividing cylinder body 313 is provided between the lifting cylinder body 312 and the buffer cylinder body 311, and a channel communicating with the extension drive hydraulic pipeline 53 and the lifting cylinder body 312 is provided in the flow dividing cylinder body 313, and the channel may be one or two. Figure 4 and Figure 7 In the figure, two connecting channels are provided, one channel is connected with the extension driving hydraulic pipeline 53, and the other channel is connected with the lifting cylinder barrel 312. The input ports of the two channels are aligned up and down. After the hydraulic oil is injected into the diverter cylinder barrel 313, the hydraulic oil reaches and is injected into the two channels at the same time, thereby starting the hydraulic drive to lift the seat cushion body 2 and extend the rocker 5.

[0040] The hydraulic driving force of the rocker arm 5 and the seat cushion body 2 is consistent. The hydraulic driving force refers to the driving force generated by the mechanical movement driven by liquid pressure. The hydraulic oil is injected into the extension drive hydraulic pipeline 53 and the lifting cylinder barrel 312 at the same time, and the drive of the seat cushion body 2 and the rocker arm 5 is started at the same time, so that the rocker arm 5 and the seat cushion body 2 are lifted in unison. During the lifting of the seat cushion body 2, the user sitting on it is also lifted, and the rocker arm 5 is extended upward synchronously. The user does not need to change the position of holding the rocker arm 5, and does not need to bend over to shake the rocker arm 5, so as to avoid the center of gravity shifting forward and tipping forward when bending over.

[0041] In some usage scenarios, when the user changes from a sitting position to a standing position, the center of gravity of the human body moves diagonally upward and forward, and the supporting center of gravity of the power-assisted wheelchair remains unchanged, which can easily lead to the user's unstable center of gravity and tipping forward. In order to facilitate the user to get up, the power-assisted wheelchair of the present application embodiment is integrated with the guide wheel telescopic function, that is, the seat cushion body 2 does not rise vertically during the rising process, but also moves forward at the same time. Therefore, when the user sits on the seat cushion body 2 and the seat cushion body 2 rises, the center of gravity relative to the wheelchair also moves forward at the same time. The design allows the guide wheel 6 to move forward to prevent the user from tipping forward due to the forward movement of the center of gravity. Figure 2 and Fig.10 As shown, the assisted-lifting wheelchair of the embodiment of the present application also includes a guide wheel 6, which includes a wheel assembly 61, a fixed seat 62, a forward-moving driving hydraulic pipeline 63 and a wheel body return spring 64. The wheel assembly 61 is movably connected to the fixed seat 62. The forward-moving driving hydraulic pipeline 63 can hydraulically drive the wheel assembly 61 to move forward relative to the fixed seat 62 to prevent the user's center of gravity from moving forward and tipping forward during the lifting of the seat cushion body 2. The wheel body return spring 64 is respectively connected to the fixed seat 62 and the wheel assembly 61 to provide the wheel assembly 61 with a backward return elastic force. The forward-moving driving hydraulic pipeline 63 is connected to the hydraulic cylinder assembly 31 so that hydraulic oil can be injected into it during the shaking of the rocker 5. In the embodiment of the present application, the guide wheel 6 is also driven forward by hydraulic pressure, and the forward-moving hydraulic pipeline is connected to the hydraulic cylinder assembly 31. The guide wheel 6 can be moved forward by shaking the rocker 5, which simplifies the structure. There is no need to set up an additional power mechanism to drive the guide wheel 6 forward. The forward movement of the guide wheel 6 in the embodiment of the present application is set before the lifting action of the seat cushion body 2, such as Figure 4 and Figure 7 The hydraulic cylinder assembly 31 is provided with a diverter cylinder body 313, and the diverter cylinder body 313 is provided with a pre-operation hydraulic pipeline 315. The hydraulic oil injected into the diverter cylinder body 313 first enters the pre-operation hydraulic pipeline 315 to perform the pre-operation action, and then is injected into the lifting cylinder body 312 to drive the seat cushion body 2 to rise.

[0042] In some usage scenarios, conventional wheelchair brakes are located at the wheels, and can be reached by hands while sitting in the wheelchair. Generally speaking, the vehicle should be braked first, and then the seat body 2 should be raised to prevent the vehicle from slipping and causing danger. However, the user may forget to brake first, and after the seat is raised to a certain height, even if the user finds that the brakes were not applied first, it is difficult to operate the brakes because the user needs to bend over to reach the wheel. Firstly, the user may not be able to reach the wheel, and secondly, bending over will cause the center of gravity of the body to move forward, and there is a risk of tipping forward. The wheelchair with an assistive lift in the embodiment of the present application is additionally provided with a linkage brake device 7, and braking will also be completed when the rocker 5 is shaken to raise the seat body 2. Even if the user forgets to brake before raising the seat, there is no risk of the vehicle slipping, thereby improving safety. Figure 2 and Figure 8As shown, the linkage brake device 7 includes a brake latch 71, a brake gear 72 and a brake drive hydraulic pipeline 73. The brake latch 71 and the brake gear 72 of the embodiment of the present application are arranged in two groups, and each wheel is provided with a group of brake gears 72, and each group of brake gears 72 corresponds to a group of brake latches 71. The brake gears 72 are connected to the wheels of the wheelchair and rotate synchronously. The brake drive hydraulic pipeline 73 can hydraulically drive the brake latch 71 to move and clamp the brake gears 72 to brake the wheels. The brake drive hydraulic pipeline 73 is connected to the hydraulic cylinder assembly 31 so that hydraulic oil can be injected into it when the rocker 5 is shaken. Figure 2 and Figure 4 As shown, the brake driving hydraulic pipeline 73 can be communicated with the pre-operation hydraulic pipeline 315 of the split cylinder body 313, and the pre-operation action of the brake is first performed, and then the seat cushion body 2 is driven to rise.

[0043] As in the above-mentioned application embodiment, the assisted wheelchair integrates the functions of seat cushion body lifting, rocker extension, guide wheel forward movement and linkage braking, and adopts the same hydraulic control system of the assisted wheelchair to realize hydraulic drive. In an optional embodiment, such as Figure 2 , Figure 4 , Figure 6 and Figure 7 As shown, the hydraulic cylinder assembly 31 also includes a diverter cylinder body 313, the diverter cylinder body 313 includes a diverter piston 314, a pre-operation hydraulic pipeline 315 and a seat cushion hydraulic pipeline 316, the diverter piston includes a piston body and an elastic spring, the pre-operation hydraulic pipeline 315 can be connected to the forward drive hydraulic pipeline 63 and the brake drive hydraulic pipeline 73, the buffer cylinder body 311 is connected to the diverter cylinder body 313, the hydraulic oil of the buffer cylinder body 311 is unidirectionally injected into the diverter cylinder body 313 via the buffer output one-way valve 36, the seat cushion hydraulic pipeline 316 is connected to the lifting cylinder body 312, the diverter piston 314 is arranged in the diverter cylinder body 313, and the diverter piston 314 is pushed to move by the hydraulic oil unidirectionally injected into the diverter cylinder body 313, and the pre-operation hydraulic The inlet of pipeline 315 is exposed first, and the hydraulic oil of diverter cylinder body 313 is injected into the pre-operation hydraulic pipeline 315 to drive the pre-operation before the seat cushion body 2 is lifted, that is, the hydraulic oil is first injected into the forward drive hydraulic pipeline 63 and the brake drive hydraulic pipeline 73 to complete the forward movement of the guide wheel 6 and the linked braking function, and then the hydraulic oil of diverter cylinder body 313 is continuously injected to push the diverter piston 314 to continue to move to expose the inlet of seat cushion hydraulic pipeline 316 and the inlet of extension drive hydraulic pipeline 53, the hydraulic oil of diverter cylinder body 313 is injected into the seat cushion hydraulic pipeline 316 and finally injected into the lifting cylinder body 312 to lift the seat cushion body 2, and at the same time, the hydraulic oil of diverter cylinder body 313 is injected into the extension drive hydraulic pipeline 53 to simultaneously drive the rocker 5 to extend synchronously.

[0044] A diverter piston 314 and a pre-operation hydraulic pipeline 315 are arranged in the diverter cylinder body 313. The hydraulic oil injected into the pre-operation hydraulic pipeline 315 can drive the completion of the preset control action, that is, to complete some necessary pre-operations before the seat cushion body 2 is raised, such as braking, moving the guide wheel 6 forward, etc. The setting of the diverter cylinder body 313 allows the whole hydraulic control system to integrate more functions, thereby improving the rationality and safety of the use of the assisted-lift wheelchair.

[0045] In the embodiment of the present application, there are many ways to assist the seat cushion body 2 of the wheelchair to descend. The hydraulic pipeline of the lifting cylinder 312 can be opened manually to release the hydraulic oil in the lifting cylinder 312 to drive the seat cushion body 2 to descend. Alternatively, a hydraulic oil release pipeline 317 can be set. Under the preset operation, the hydraulic oil release pipeline 317 is opened, and the hydraulic oil in the lifting cylinder 312 is released through the hydraulic oil release pipeline 317 to drive the seat cushion body 2 to descend. Figure 4 and Figure 7 As shown, the hydraulic cylinder assembly 31 also includes a hydraulic oil release line 317, and the hydraulic oil release line 317 is connected to the lifting cylinder body 312. Specifically, the hydraulic oil release line 317 is arranged on the diverter cylinder body 313, and an output port in the cavity of the diverter cylinder body 313 connects the hydraulic oil release line 317 with the seat cushion hydraulic line 316. The hydraulic oil release line 317 can be on the channel of the seat cushion hydraulic line 316. The caliber of the input end of the hydraulic oil release line 317 is smaller than the caliber of the seat cushion hydraulic line 316. The hydraulic oil injected into the diverter cylinder body 313 is relatively easy to be input into the seat cushion hydraulic line 316 by the hydraulic oil release line 317, and the hydraulic oil release line is in a normally closed state. The hydraulic piston rod 32 is connected with the hydraulic oil release line 317 to open or block the communication path between the hydraulic oil release line 317 and the lifting cylinder body 312. Specifically, as shown in FIG. Figure 4 , Figure 6 and Figure 7 As shown, the hydraulic piston rod 32 includes a movable connecting rod 38, and the movable connecting rod 38 is provided with a plurality of oil release holes 381. When the hydraulic piston rod 32 is locked in a preset position, the hydraulic oil release line 317 is aligned with the oil release hole 381 to communicate with the lifting cylinder body 312 through the oil release hole 381. The hydraulic oil in the lifting cylinder body 312 is released through the hydraulic oil release line 317 to drive the seat cushion body 2 to descend. That is, the passage between the hydraulic oil release line 317 and the lifting cylinder body 312 is in a closed state. When the hydraulic piston rod 32 is locked in a preset position, the passage between the hydraulic oil release line 317 and the lifting cylinder body 312 is triggered to open, and the hydraulic oil in the lifting cylinder body 312 is discharged through the hydraulic oil release line 317, and the lifting piston rod 33 retracts into the lifting cylinder body 312, and the seat cushion body 2 descends.

[0046] The hydraulic connecting rod and the hydraulic piston rod 32 can be an integral structure or be designed as a linkage structure. When the oil release hole 381 of the movable connecting rod 38 is aligned with the hydraulic oil release pipeline 317, the hydraulic oil release pipeline 317 is connected to the lifting cylinder body 312. When the oil release hole 381 of the movable connecting rod 38 is in other positions, the connecting passage between the hydraulic oil release pipeline 317 and the lifting cylinder body 312 is in a closed state. The movable connecting rod 38 can move back and forth with the hydraulic piston rod 32. When the movable connecting rod 38 is in an active state, the oil release hole 381 is not stationary in the same position. The movable connecting rod 38 isolates the hydraulic oil release pipeline 317 from the connecting passage of the lifting cylinder barrel 312. When the hydraulic piston rod 32 is locked in a preset position, the oil release hole 381 of the movable connecting rod 38 is aligned with the hydraulic oil release pipeline 317, one end of the oil release hole 381 is connected to the hydraulic oil release pipeline 317, and the other end of the oil release hole 381 is connected to the lifting cylinder barrel 312, and the passage between the hydraulic oil release pipeline 317 and the lifting cylinder barrel 312 is connected. In an optional embodiment, the hydraulic oil release line 317 is arranged around the split cylinder body 313, and output ports connected to the hydraulic oil release line 317 are respectively arranged at both ends of the split cylinder body 313 cavity. The hydraulic oil in the lifting cylinder body 312 and the split cylinder body 313 cavity can be discharged from the hydraulic cylinder assembly 31 through the three branches of the hydraulic oil release line 317. Figure 4 As shown, the branch of the hydraulic oil release line 317 connected to the seat cushion hydraulic line 316 is the first branch 317a, the branch of the hydraulic oil release line 317 arranged on the front side of the diverter piston 314 is the second branch 317b, and the branch of the hydraulic oil release line 317 arranged on the rear side of the diverter piston 314 is the third branch 317c. When the hydraulic piston rod 32 moves, the corresponding oil release through hole 381 is not aligned with the second branch 317b and the third branch 317c, and the second branch 317b and the third branch 317c are in a closed state. The diverter piston 314 is compressed by the driving action of the hydraulic oil, gradually exposing the pre-operation hydraulic line 315 and the seat cushion hydraulic line 316, and the hydraulic oil is injected into the corresponding functional components via the pre-operation hydraulic line 315 and the seat cushion hydraulic line 316. On the one hand, in extreme cases, the hydraulic pressure of the hydraulic cylinder assembly 31 is too large, and the diverter piston 314 is further compressed. At this time, the cooperation between the diverter piston 314 and the third branch 317c can act as a relief valve, reducing the load of the hydraulic cylinder assembly 31 and improving the safety of use; on the other hand, the last assist operation may leave hydraulic oil in the diverter cylinder body 313. During the current hydraulic oil injection process, the hydraulic oil remaining in the diverter cylinder body 313 can be discharged along the third branch 317c. Figure 5 and Figure 7As shown, the hydraulic cylinder assembly 31 includes a piston rod locking mechanism 37, which is connected to the hydraulic piston rod 32 to lock the hydraulic piston rod 32 in a preset position. The hydraulic piston rod 32 is provided with a limiting convex ring, and a corresponding limiting convex ring is provided in the buffer cylinder body 311. When the two limiting convex rings are sleeved together (such as Figure 7 As shown in the figure, the piston rod locking mechanism 37 can lock the hydraulic piston rod 32 at the end position of the buffer cylinder barrel 311 by means of the engagement of the bayonet pin and the bayonet hole. When the hydraulic piston rod 32 is locked at the end position of the buffer cylinder barrel 311, the two oil release holes 381 on the movable connecting rod 38 are respectively connected with the second branch 317b and the third branch 317c, so that the hydraulic oil release pipeline 317 is connected with the lifting cylinder barrel 312 and the diverter cylinder barrel 313, and the passage is open.

[0047] In some usage scenarios, when the seat cushion body 2 is raised, limiting the lifting piston rod 33 from retracting into the lifting cylinder body 312 can avoid unstable hydraulic control or abnormal operation caused by pressure fluctuations of the hydraulic actuator. For example, if the user's center of gravity is unstable and he sits back heavily on the seat cushion body 2 again, the instantaneous impact will affect the hydraulic control pipeline. Compared with locking the movement direction of the lifting piston rod 33, the embodiment of the present application only limits the lifting piston rod 33 from retracting into the lifting cylinder body 312, and the lifting piston rod 33 can still extend out of the lifting cylinder body 312 to drive the seat cushion body 2 to rise. Figure 3 and Figure 7 As shown, the lifting piston rod 33 includes a one-way stop rack 331 and a locking pin 332. The locking pin 332 and the one-way stop rack 331 are connected in cooperation. The locking pin 332 can be inserted into the one-way stop rack 331 to limit the lifting piston rod 33 from retracting into the lifting cylinder body 312 when the lifting cylinder body 312 is injected with hydraulic oil. The one-way stop rack 331 and the locking pin 332 have ratchet teeth in opposite directions, which limit the movement direction of the lifting piston rod 33 in the lifting cylinder body 312, allowing the lifting piston rod 33 to gradually move out of the lifting cylinder body 312 in one direction, and limit the lifting piston rod 33 from retracting into the lifting cylinder body 312, so that the seat cushion body 2 is gradually and stably raised.

[0048] There are many ways to drive the locking pin 332 to engage or disengage the one-way stop rack 331. In order to simplify the structure and optimize the convenience of operation, the movable action of the locking pin 332 of the embodiment of the present application is linked with the hydraulic piston rod 32. Figure 3 and Figure 7The hydraulic piston rod 32 includes a linkage connection 34 and a latch spring 35. The locking latch 332 is arranged above the lifting piston rod 33. The latch spring 35 is connected to the locking latch 332 to push the locking latch 332 to be stuck into the one-way stop rack 331, that is, the locking latch 332 clamps the lifting piston rod 33 under the elastic force of the spring, limiting the lifting piston rod 33 from retracting into the lifting cylinder body 312. The linkage connector 34 is respectively connected with the hydraulic piston rod 32 and the locking latch 332. When the hydraulic piston rod 32 is locked in the preset position, the locking latch 332 is pulled to unlock the lifting piston rod 33. One end of the linkage connector 34 is arranged at the end of the movable connecting rod 38, and the other end of the linkage connector 34 is fixed to the locking latch 332. The linkage connector 34 can be a rope or elastic belt structure. When the hydraulic piston rod 32 extends out of the buffer cylinder body 311 to the rightmost position and is locked, the movable connecting rod 38 moves to the right, straightens through the linkage connector 34 and pulls the locking latch 332 out of the one-way stop rack 331, unlocking the lifting piston rod 33. Through the linkage connector 34 and the locking latch 332, the hydraulic piston rod 32 can be linked to limit the movable direction of the lifting piston rod 33. When the rocker 5 is shaken, the hydraulic piston rod 32 and the linkage connector 34 have no force applied to them. The locking pin 332 is subjected to the force of the pin spring 35 and is stuck in the one-way stop rack 331, restricting the lifting piston rod 33 to only extend out of the lifting cylinder barrel 312 and not to retract. The hydraulic piston rod 32 is locked in a preset position. The hydraulic piston rod 32 pulls the locking pin 332 through the linkage connector 34, pulling the locking pin 332 out of the one-way stop rack 331, thereby unlocking the lifting piston rod 33 in linkage, so that the direction in which the lifting piston rod 33 retracts into the lifting cylinder barrel 312 is no longer restricted. The driving structure of the locking pin 332 is simplified, and no additional driving method is required, which is conducive to reducing costs.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A wheelchair that assists in lifting, comprising a seat frame, a seat cushion body and a seat lifting device, wherein the seat lifting device is in transmission connection with the seat cushion body to drive the seat cushion body to rise and fall relative to the seat frame, and wherein: The seat lifting device includes a hydraulic actuator, a hydraulic oil tank and a rocker arm. The hydraulic actuator includes a hydraulic cylinder assembly, a hydraulic piston rod and a lifting piston rod. The hydraulic cylinder assembly is provided with a buffer cylinder body and a lifting cylinder body. The buffer cylinder body is connected to the lifting cylinder body and a buffer output check valve is provided on the connected passage. The hydraulic piston rod is connected to the rocker arm in transmission. The lifting piston rod is connected to the lifting cylinder body to extend or retract the lifting cylinder body. The lifting piston rod is connected to the seat cushion body to drive the seat cushion body to rise and fall. The hydraulic piston rod is connected to the buffer cylinder body to move back and forth in the buffer cylinder body. The hydraulic piston rod is provided with a hydraulic oil injection pipeline and a hydraulic oil injection check valve. The hydraulic oil injection pipeline is connected to the hydraulic oil tank. When the rocker arm is shaken back and forth, the hydraulic piston rod moves back and forth in the buffer cylinder body to pass the hydraulic oil The injection pipeline and the hydraulic oil injection check valve successively draw hydraulic oil from the hydraulic oil tank and inject it into the buffer cylinder body in one direction, and successively inject the hydraulic oil in the buffer cylinder body into the lifting cylinder body through the cache output check valve. The hydraulic oil injected into the lifting cylinder body drives the lifting piston rod to extend out of the lifting cylinder body to drive the seat cushion body to rise. The rocker arm includes a fixed rod, a movable rod, an extension drive hydraulic pipeline and a movable rod return spring. The fixed rod is movably connected to the movable rod. The extension drive hydraulic pipeline can hydraulically drive the movable rod to move upward relative to the fixed rod so that the rocker arm can synchronously extend upward during the lifting process of the seat cushion body. The movable rod return spring is respectively connected to the movable rod and the fixed rod to provide a downward pulling force to the movable rod. The extension drive hydraulic pipeline is connected to the hydraulic cylinder assembly, and the extension drive hydraulic pipeline and the lifting cylinder body are injected with hydraulic oil at the same time.

2. The wheelchair as claimed in claim 1, characterized in that: The guide wheel also includes a wheel body assembly, a fixed seat, a forward drive hydraulic pipeline and a wheel body return spring. The wheel body assembly is movably connected to the fixed seat. The forward drive hydraulic pipeline can hydraulically drive the wheel body assembly to move forward relative to the fixed seat to prevent the user's center of gravity from shifting forward and tipping forward during the lifting of the seat cushion body. The wheel body return spring is respectively connected to the fixed seat and the wheel body assembly to provide the wheel body assembly with elastic force to return to the rear. The forward drive hydraulic pipeline is connected to the hydraulic cylinder assembly so that hydraulic oil can be injected into it when the rocker arm is shaken.

3. The wheelchair as claimed in claim 1, characterized in that: It also includes a linkage brake device, which includes a brake pin, a brake gear and a brake drive hydraulic pipeline. The brake gear is connected to the wheel of the wheelchair and rotates synchronously. The brake drive hydraulic pipeline can hydraulically drive the brake pin to move and clamp the brake gear to brake the wheel. The brake drive hydraulic pipeline is connected to the hydraulic cylinder assembly so that hydraulic oil can be injected into it when the rocker arm is shaken.

4. The wheelchair as claimed in claim 1, characterized in that: The hydraulic cylinder assembly also includes a diverter cylinder body, which includes a diverter piston, a pre-operation hydraulic pipeline and a seat cushion hydraulic pipeline. The buffer cylinder body is connected to the diverter cylinder body, and the hydraulic oil of the buffer cylinder body is unidirectionally injected into the diverter cylinder body via a buffer output one-way valve. The seat cushion hydraulic pipeline is connected to the lifting cylinder body. The diverter piston is arranged in the diverter cylinder body, and the diverter piston is pushed to move by the hydraulic oil unidirectionally injected into the diverter cylinder body. The inlet of the pre-operation hydraulic pipeline is exposed first, and the hydraulic oil of the diverter cylinder body is injected into the pre-operation hydraulic pipeline to drive the pre-operation before the seat cushion body is lifted. Thereafter, the hydraulic oil that continues to be injected into the diverter cylinder body pushes the diverter piston to continue moving to expose the inlet of the seat cushion hydraulic pipeline. The hydraulic oil of the diverter cylinder body is injected into the seat cushion hydraulic pipeline and finally injected into the lifting cylinder body to lift the seat cushion body.

5. The wheelchair as claimed in claim 1, characterized in that: The hydraulic cylinder assembly also includes a hydraulic oil release pipeline, which is connected to the lifting cylinder body. The hydraulic piston rod is cooperatively connected to the hydraulic oil release pipeline to open or block the communication path between the hydraulic oil release pipeline and the lifting cylinder body. When the hydraulic piston rod is locked in a preset position, the communication path between the hydraulic oil release pipeline and the lifting cylinder body is opened, and the hydraulic oil of the lifting cylinder body is released through the hydraulic oil release pipeline to drive the seat cushion body to descend.

6. The wheelchair as claimed in claim 5, characterized in that: The hydraulic piston rod comprises a movable connecting rod, which is provided with a plurality of oil release through holes. When the hydraulic piston rod is locked in a preset position, the hydraulic oil release pipeline is aligned with the oil release through holes to communicate with the lifting cylinder barrel through the oil release through holes.

7. The wheelchair as claimed in claim 1, characterized in that: The lifting piston rod includes a one-way stop rack and a locking pin, which are cooperatively connected with the one-way stop rack. The locking pin can be inserted into the one-way stop rack to limit the lifting piston rod from retracting into the lifting cylinder body when the lifting cylinder body is injected with hydraulic oil.

8. The wheelchair as claimed in claim 7, characterized in that: The hydraulic piston rod includes a linkage connection piece and a latch spring. The latch spring is connected to the locking latch to push the locking latch to engage in the one-way stop rack. The linkage connection piece is respectively connected to the hydraulic piston rod and the locking latch so that when the hydraulic piston rod is locked in a preset position, the locking latch is pulled to unlock the lifting piston rod.

9. The wheelchair as claimed in claim 1, characterized in that: The hydraulic cylinder assembly comprises a piston rod locking mechanism, which is cooperatively connected with the hydraulic piston rod to lock the hydraulic piston rod in a preset position.

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