CN118680762A - Wheelchair and wheelchair control method - Google Patents

Abstract

A wheelchair and a method for manufacturing the wheelchair, wherein the wheelchair does not put a user in an unstable posture when transferring. The wheelchair (1) comprises: a frame (10); a seat (40) having a seat surface (41) on which a user sits and mounted on the frame (10); a transfer assist mechanism (60) mounted on the frame (10) and adjusting the tilt angle and height relative to the frame (10) and assisting in switching between a standing state in which the user stands up and a sitting state in which the user sits on the seat (40); and a controller (71) controlling the movement trajectory of the user in the transfer action while adjusting the tilt angle and height of the transfer assist mechanism (60), wherein the controller (71) controls the transfer assist mechanism (60) so that the movement trajectory when switching from the standing state to the sitting state allows the user to move in a state in which the user maintains a forward leaning posture more than the movement trajectory when switching from the sitting state to the standing state.

Description

Wheelchair and wheelchair control method

Technical Field

The invention relates to a wheelchair and a method for controlling the wheelchair.

Background Art

Patent document 1 discloses a transfer assistance device comprising a trolley portion, an upper body holding portion for holding the upper body of a care recipient, and a support portion for supporting the upper body holding portion so as to be movable relative to the trolley portion, the support portion having an upper body cylinder for moving the upper body holding portion, and an inclination angle adjustment slider for changing the inclination angle of the upper body holding portion.

Prior art literature

Patent Literature

Patent Document 1: Japanese Patent Application Publication No. 2016-140435

Problems to be Solved by the Invention

However, in the transfer assisting device of Patent Document 1, the care recipient takes a posture of stretching the knees, raising the waist, and leaning the upper body forward greatly when transferring. At this time, the care recipient uses the knees as a fulcrum, and the position of the head moves far forward from the plumb line of the fulcrum, and the weight is placed on the front holding part of the upper body holding part. Therefore, the care recipient takes an unstable posture of leaning far forward, and the chest supported by the front holding part is compressed, and there is a possibility that the head will feel like falling forward.

Summary of the invention

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to prevent the user from being placed in an unstable posture during transfer.

In one embodiment of the present invention, a wheelchair comprises: a frame; a seat having a seat surface for a user to sit on and mounted on the frame; a transfer assist mechanism mounted on the frame, adjusting an inclination angle and a height relative to the frame to assist in switching a transfer action between a standing state in which the user is supported and the sitting state in which the user is sitting on the seat; a controller that controls a movement trajectory of the user in the transfer action while adjusting an inclination angle and a height of the transfer assist mechanism, the controller controlling the transfer assist mechanism so that the movement trajectory when switching from the standing state to the sitting state allows the user to move while maintaining a forward-leaning posture more than the movement trajectory when switching from the sitting state to the standing state.

Effects of the Invention

According to an aspect of the present invention, it is possible to prevent the user from being placed in an unstable posture during transfer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a wheelchair according to an embodiment of the present invention.

FIG. 2 is an exploded view of the main parts of FIG. 1 .

Figure 3 is a control block diagram of a wheelchair.

FIG. 4 is a side view for explaining the operation of extending the support column and raising the arm.

FIG. 5 is a side view showing the movement of the support column tilting forward and backward from the reference position.

FIG. 6 is a side view showing the seat rotation operation.

FIG. 7 is a diagram for explaining the movement trajectory of the user and the operation of the transfer assistance mechanism when the user is shifted from the seated state to the standing state.

FIG. 8 is a diagram for explaining the movement trajectory of the user and the operation of the transfer assistance mechanism when the user is shifted from the standing state to the seated state.

FIG. 9 is a diagram comparing the case of the user's movement trajectory shown in FIG. 8 and the case of switching the user from the standing state to the sitting state along the same trajectory as when switching the user from the sitting state to the standing state.

Description of Reference Numerals

1. Wheelchair

10: Framework

40: Seat

41: Seat

60: Transfer assistance mechanism

62: Arm

63: Pillar

71: Controller

DETAILED DESCRIPTION

Hereinafter, a wheelchair 1 according to an embodiment of the present invention will be described with reference to the drawings.

First, the structure of the wheelchair 1 is described with reference to Figures 1 to 6. Hereinafter, the longitudinal direction of the wheelchair 1 is referred to as the "front-rear direction", the width direction of the wheelchair 1 is referred to as the "left-right direction", and the height direction of the wheelchair 1 is referred to as the "up-down direction".

Fig. 1 is a perspective view of a wheelchair 1. Fig. 2 is an exploded view of the main parts in Fig. 1. Fig. 3 is a control block diagram of the wheelchair 1. Fig. 4 is a side view illustrating the movement of the support column 63 extending and the arm 62 rising. Fig. 5 is a side view illustrating the movement of the support column 63 tilting forward and backward from the reference position. Fig. 6 is a side view illustrating the movement of the seat 40 rotating.

The wheelchair 1 includes a frame 10, a plurality of wheels 20, a drive mechanism 30, a seat 40, a seat moving mechanism 50, a transfer assisting mechanism 60, a control unit 70, and an operating unit 80 (see FIG. 3 ). The wheelchair 1 is a component that allows a user (not shown) to stand up without the need for a caregiver to take care of the user even when the user cannot stand up by his/her own strength.

As shown in Fig. 1 and Fig. 2, the frame 10 constitutes the main body of the wheelchair 1. The frame 10 is formed in a substantially rectangular ladder shape. Wheels 20 are provided at the four corners of the frame 10, respectively. The frame 10 is supported by the wheels 20. The frame 10 supports the drive mechanism 30, the seat 40, the seat moving mechanism 50, the transfer assisting mechanism 60, the control unit 70, and the operating unit 80.

The wheel 20 is rotatably mounted on the frame 10 and supports the frame 10. The wheel 20 includes a pair of driving wheels 21 and a pair of driven wheels 22.

The driving wheel 21 is a front wheel provided at the front side (front end) of the frame 10. The driving wheel 21 is a small wheel provided in a non-steerable manner in the front-rear direction of the frame 10. A pair of driving wheels 21 are provided at intervals in the left-right direction. The driving wheel 21 is driven and rotated by a driving motor 31 as a driving unit described later.

The driven wheel 22 is a rear wheel provided at the rear side (rear end) of the driving wheel 21 of the frame 10. The driven wheel 22 is an omnidirectional wheel that can rotate freely in the front-to-back direction of the frame 10 and slide freely in the left-to-right direction of the frame 10 (refer to FIG. 4 ). A pair of driven wheels 22 are provided at intervals in the left-to-right direction. The driven wheel 22 rotates in the front-to-back direction and slides in the left-to-right direction as the frame 10 moves.

In this way, by using the front wheel as the driving wheel 21 and the rear wheel as the driven wheel 22, the height of the rear wheel can be suppressed, and the rear wheel can enter the space below the bed 2 (see FIG4 ) and the like. In addition, by using the driven wheel 22 as an omnidirectional movable wheel, the rear wheel does not vibrate left and right as in the case of using a free wheel, so that the driven wheel 22 can enter a narrow space such as a toilet (not shown).

The driving mechanism 30 includes driving motors 31 as a pair of driving actuators.

The driving motor 31 is arranged so that the rotation axis is located in the axle direction of the driving wheel 21. The driving motor 31 is arranged in a straight line between the pair of driving wheels 21. The driving motor 31 is supported at the front end of the frame 10 via a supporting member 31a. The driving motor 31 has a speed reducer 31b that reduces the rotation of the motor and transmits it to the driving wheel 21. As shown in FIG. 3, the driving motor 31 is electrically connected to a controller 71 described later, and rotates according to an electrical signal input from the controller 71.

As shown in Fig. 1 and Fig. 2 , the seat 40 includes a seat surface 41 and a linear actuator 42 as a lifting actuator. The seat 40 is attached to a driven sprocket 52 described later and rotates together with the driven sprocket 52.

The seat surface 41 is a portion where the user sits. The seat surface 41 is mounted on the frame 10 so as to be movable between at least a seated position where the user sits and a retreated position where the user can enter and exit from the rear of the frame 10 (see FIG. 6 ). The seat surface 41 is provided so as to be movable between the seated position and the retreated position, so that the strength for the user to sit can be ensured without dividing the seat surface 41 itself.

The direct-acting actuator 42 raises and lowers the seat surface 41. By providing the direct-acting actuator 42, for example, the height of the seat surface 41 can be adjusted so that the seat surface 41 of the chair 40 is located above the bed 2 (see FIG. 4 ). As shown in FIG. 3 , the direct-acting actuator 42 is electrically connected to a controller 71 described later, and is extended and retracted according to an electrical signal input from the controller 71. The direct-acting actuator 42 is configured by, for example, having a built-in motor and a ball screw mechanism.

As shown in FIG. 1 and FIG. 2 , the seat moving mechanism 50 includes a driving sprocket 51 , a driven sprocket 52 , a chain 53 as a transmission member, and a turning motor 54 as a turning actuator.

The driving sprocket 51 is horizontally mounted on the upper portion of the frame 10. The driving sprocket 51 is mounted on the rotating shaft of the rotating motor 54. The driving sprocket 51 is rotationally driven by the rotating motor 54.

The driven sprocket 52 is horizontally mounted at the lower part of the seat 40. The rotation of the driving sprocket 51 is transmitted to the driven sprocket 52 via the chain 53. The diameter of the driven sprocket 52 is formed larger than the diameter of the driving sprocket 51. Thus, the torque of the rotating motor 54 is amplified and transmitted to the driven sprocket 52.

The driven sprocket 52 is located in front of the seat surface 41. That is, the seat surface 41 is located in the rear of the driven sprocket 52. Therefore, when the driven sprocket 52 rotates, the seat surface 41 can rotate greatly to the side with the center axis of the driven sprocket 52 as the rotation axis and the distance from the center axis of the driven sprocket 52 as the rotation radius.

The chain 53 is wound around the driving sprocket 51 and the driven sprocket 52. In addition, instead of the chain 53, a belt or a power transmission shaft or the like may be used to transmit the power of the rotation motor 54.

As shown in Fig. 3, the rotation motor 54 is electrically connected to a controller 71 described later, and rotates according to an electrical signal input from the controller 71. As shown in Fig. 2, the rotation motor 54 rotates the seat 40. Specifically, the rotation motor 54 rotates the seat surface 41 between a seated position behind the transfer assisting mechanism 60 and a retracted position in the left-right direction of the seated position.

As shown in Fig. 1 and Fig. 2, the transfer assisting mechanism 60 is mounted on the frame 10. The transfer assisting mechanism 60 adjusts the tilt angle and height relative to the frame 10, and assists the transfer action of switching between the standing state in which the user stands up while supporting the user and the sitting state in which the user sits on the seat 40. The transfer assisting mechanism 60 includes a footrest 61, an arm 62, a pair of support columns 63, a knee contact portion 64, a pair of electric cylinders 65 as tilting actuators, and an electric cylinder 66 as a telescopic actuator.

The footrest 61 supports the user's feet. The footrest 61 is a substantially semicircular plate. The footrest 61 is formed to be larger than the size of the user's feet so that the user can sit on it. When the support column 63 tilts (tilts), the footrest 61 tilts integrally with the support column 63 in conjunction.

The arm 62 supports the user's arm. Specifically, the arm 62 supports the user's armpit from below. The arm 62 is formed in a U shape, and is supported by the support 63 at the center. When the support 63 tilts, the arm 62 tilts together with the support 63.

The support column 63 supports the arm 62 on the frame 10. A pair of support columns 63 are arranged in parallel with a gap in the left-right direction. The support column 63 is supported on the upper part of the frame 10 by a bearing 63a so as to be rotatable in the front-back direction. The support column 63 is extended and retracted to raise and lower the arm 62. The footrest portion 61 and the support column 63 are arranged so as to be able to tilt in the front-back direction of the frame 10 as a whole. Specifically, the support column 63 can move to a reference position substantially perpendicular to the frame 10, a forward tilted position tilted forward from the reference position, and a rearward tilted position tilted rearward from the reference position.

The knee abutment 64 is mounted on the support column 63. The knee abutment 64 is provided at the substantially center in the height direction of the rear part of the support column 63. The knee abutment 64 supports the user's knee from the front when the arm 62 holds the user's armpit from below. The knee abutment 64 is in direct contact with the user's knee, and therefore is formed of a member with high cushioning properties such as an elastic body such as elastic rubber or resin.

A pair of electric cylinders 65 are connected between the upper portion of the frame 10 and the front portion of each support column 63. As shown in FIG3 , the electric cylinders 65 are electrically connected to a controller 71 described later, and extend and retract according to an electric signal input from the controller 71. When the electric cylinders 65 are retracted, the support column 63 tilts forward relative to the frame 10. When the electric cylinders 65 are extended, the support column 63 tilts backward relative to the frame 10.

As shown in FIGS. 1 and 2 , the electric cylinder 66 is connected between the upper portion of the frame 10 and the lower portion of the arm 62. The electric cylinder 66 is provided between the pair of pillars 63 in parallel with the pillars 63. As shown in FIG. 3 , the electric cylinder 66 is electrically connected to a controller 71 described later, and is extended and retracted according to an electrical signal input from the controller 71. When the electric cylinder 66 is extended, the pillar 63 is extended, and the arm 62 is raised relative to the frame 10. When the electric cylinder 66 is retracted, the pillar 63 is retracted, and the arm 62 is lowered relative to the frame 10.

As described above, when assisting the user's transfer action, the transfer assist mechanism 60 supports the user's entire body by supporting the user's feet with the support column 63 tilted forward and the footrest portion 61 supports the user's feet, the arm 62 supports the user's arms, and the knee abutment portion 64 supports the user's knees.

In this state, the user can get on the wheelchair 1 by moving the seat 40 from the evacuated position to the seated position. On the other hand, in this state, the user can get off the wheelchair 1 and move to the bed 2 (see FIG. 4 ) at the rear by moving the seat 40 from the seated position to the evacuated position. In addition, the footrest 61 supports the foot, and the knee abutment 64 supports the knee, so that the transfer assist mechanism 60 can support the whole body in a stable posture while the angle of the user's feet is constant. The specific function of the transfer assist mechanism 60 will be described in detail later with reference to FIGS. 4 to 9 .

The control unit 70 includes a controller 71 and a power storage unit 72 .

The controller 71 is composed of a microcomputer including a CPU, a RAM, a ROM, an input/output interface, etc. The controller 71 reads out and executes a program stored in the ROM through the CPU, thereby performing various processes. The controller 71 may also be composed of a plurality of microcomputers.

The controller 71 controls the movement trajectory of the user during the transfer action while adjusting the tilt angle and height of the transfer assisting mechanism 60. The controller 71 controls the actions of the drive motor 31, the linear actuator 42, the rotation motor 54, the electric cylinder 65, and the electric cylinder 66 based on a signal input from an operation unit 80 described later.

The power storage unit 72 is accommodated in the housing 70a of the control unit 70. The power storage unit 72 supplies power to the drive motor 31, the linear actuator 42, the rotation motor 54, the electric cylinder 65, the electric cylinder 66, and the controller 71. The power storage unit 72 is composed of a secondary battery such as a lithium ion battery.

As shown in FIG. 3 , the operation portion 80 includes a first operation portion 81 and a second operation portion 82 .

The first operating part 81 is provided at a position where the user can operate it when sitting on the wheelchair 1. The first operating part 81 operates the driving mechanism 30. The first operating part 81 is, for example, a lever that moves the wheelchair 1 in the desired direction when the user pulls down the lever in the desired direction.

The second operating part 82 is provided at a position where the user can operate it both when the user is sitting on the wheelchair 1 and when the user is getting off the wheelchair 1. The second operating part 82 is connected to the controller 71, for example, via a cable. The second operating part 82 operates the operation of the seat moving mechanism 50 and the transfer assisting mechanism 60. In addition, when a caregiver is present, the second operating part 82 can also be operated by the caregiver. The second operating part 82 includes: an arm raising button 82a, an arm lowering button 82b, a pillar forward tilting button 82c, a pillar rearward tilting button 82d, a seat rotation button 82e, a seat reverse rotation button 82f, a seat raising button 82g, a seat lowering button 82h, a standing up action start button 82i as a standing up action operating part, and a sitting action start button 82j as a sitting action starting part.

4, when the arm raising button 82a is pressed, the controller 71 extends the support column 63 by extending the electric cylinder 66, thereby raising the arm 62. When the arm lowering button 82b is pressed, the controller 71 contracts the support column 63 by contracting the electric cylinder 66, thereby lowering the arm 62.

5, when the pillar forward tilt button 82c is pressed, the controller 71 causes the electric cylinder 65 to contract, thereby tilting the footrest 61 and the pillar 63 forward. When the pillar backward tilt button 82d is pressed, the controller 71 causes the electric cylinder 65 to extend, thereby tilting the footrest 61 and the pillar 63 backward.

As shown in Fig. 6, when the seat rotation button 82e is pressed, the controller 71 rotates the driven sprocket 52 via the driving sprocket 51 and the chain 53 by the rotation motor 54, and rotates the seat surface 41 to either the left or right side. When the seat reverse rotation button 82f is pressed, the controller 71 rotates the driven sprocket 52 via the rotation motor 54 via the driving sprocket 51 and the chain 53, and rotates the seat surface 41 to either the left or right side.

When the seat up button 82g is pressed, the controller 71 extends the linear actuator 42 to raise the seat surface 41. When the seat down button 82h is pressed, the controller 71 contracts the linear actuator 42 to lower the seat surface 41.

When the standing action start button 82i is pressed, the controller 71 performs a series of standing actions for transferring the user from the seated state to the standing state in the transfer action for transferring the user. When the sitting action start button 82j is pressed, the controller 71 performs a series of sitting actions for transferring the user from the standing state to the seated state in the transfer action for transferring the user.

7 to 9 , the transfer operation of switching between the standing state in which the user stands up and the seated state in which the user sits on the seat 40 will be described. The controller 71 reads out and executes a program stored in the ROM through the CPU, thereby executing the transfer operation of the transfer assisting mechanism 60.

Fig. 7 is a diagram for explaining the movement trajectory of the user when the user is shifted from the seated state to the standing state and the operation of the transfer assistance mechanism. Fig. 8 is a diagram for explaining the movement trajectory of the user when the user is shifted from the standing state to the seated state and the operation of the transfer assistance mechanism. Fig. 9 is a diagram for comparing the case of the movement trajectory of the user shown in Fig. 8 with the case of shifting the user from the standing state to the seated state along the same trajectory as when the user is shifted from the seated state to the standing state.

In Fig. 7 to Fig. 9, the user's movement trajectory is represented by a line graph composed of the foot 91, the calf 92, the thigh 93, and the upper body 94. In Fig. 9, the grounding point of the user's foot 91 is represented as the fulcrum SP, the imaginary straight line passing through the fulcrum SP and extending in the vertical direction is represented as the vertical line VL, and the user's center of gravity position (the position of the pubic region) is represented as the center of gravity CG.

First, the movement trajectory of the user when the user changes from the seated state to the standing state and the operation of the transfer assistance mechanism 30 will be described with reference to Fig. 7. When the user is in the seated state, when the user or the caregiver presses the standing action start button 82i, the controller 71 causes the transfer assistance mechanism 60 to perform the standing action assistance.

In the seated state, the transfer assist mechanism 60 is in a state where the pillar 63 is in a rearwardly inclined position and the arm 62 is lowered. At this time, the user is seated on the seat 40. The user's feet 91 are on the ground, and the thighs 93 are in a substantially horizontal state.

Next, when the controller 71 extends the electric cylinder 66 and slightly raises the arm 62, the process switches to the first stage. At this time, the arm 62 is raised to a degree that the user's waist can be lifted from the seat 40. As a result, the user hugs his armpits from below as the arm 62 rises, and the waist leaves the seat 40, so that only the toes of the feet 91 are grounded and the heels are floating.

Next, when the controller 71 contracts the electric cylinder 65 and tilts the support column 63 forward to the reference position, the vehicle enters the second stage. As a result, the user's upper body 94 tilts forward as the support column 63 tilts forward, and the waist is further lifted from the seat 40.

Next, the controller 71 further contracts the electric cylinder 65 to tilt the support column 63 forward to the forward tilted position, and further extends the electric cylinder 66 to raise the arm 62, and then the user enters the third stage. As a result, the user's armpits are lifted up diagonally forward from below, the upper body 94 is kept tilted forward, the waist is greatly separated from the seat 40, and the angle of the thigh 93 is close to vertical.

Next, the controller 71 extends the electric cylinder 65 to tilt the support column 63 backward to the reference position, and further extends the electric cylinder 66 to raise the arm 62, thereby switching to the standing state. In this way, the user is lifted up from the armpits to the oblique rearward direction, and the upper body 94 that has been tilted forward stands up.

In this way, the user can switch from the sitting state to the standing state with the assistance of the transfer assisting mechanism 60. In addition, the movement trajectory of the user at this time is the same movement trajectory as the action of the caregiver picking up the user and making him stand up.

In addition, the user is in a posture close to a standing position in the standing state, and is in a state where the user's weight is placed on the transfer assistance mechanism 60. Therefore, the user's weight is distributed and maintained at the armpits, chest, knees, and the backs of the feet 91.

Next, the movement trajectory of the user when the user switches from the standing state to the sitting state and the action of the transfer assistance mechanism are described with reference to Fig. 8. When the user is in the standing state, when the user or the caregiver presses the sitting action start button 82j, the controller 71 causes the transfer assistance mechanism 60 to perform the action of assisting the sitting action.

In the standing state, the transfer assisting mechanism 60 is in a state where the support column 63 is in the reference position and the arm 62 is raised. At this time, the user's waist is greatly separated from the seat 40 and is in a standing state. In the standing state, the user is in a posture close to a standing position and is in a state where the weight of the user is placed on the transfer assisting mechanism 60. Therefore, the weight of the user is distributed and maintained in the armpits, chest, knees, and the back of the feet 91.

Next, when the controller 71 contracts the electric cylinder 65 to tilt the support column 63 forward to the forward tilted position, and contracts the electric cylinder 66 to lower the arm 62, the state is switched to the first state. As a result, the user is in a state where the armpits are lifted from below and lowered diagonally forward, the angle of the thigh 93 is close to vertical, and the upper body 94 in the upright state is tilted forward.

Next, when the controller 71 further contracts the electric cylinder 66 to lower the arm 62, the second stage is switched. Thus, the user's upper body 94 is lowered while the armpits are lifted from below, so the upper body 94 further leans forward and the waist is slightly closer to the seat 40.

Then, the controller 71 extends the electric cylinder 65 to tilt the support column 63 backward to the reference position, and then the process is switched to the third stage. Therefore, as the support column 63 tilts backward, the user is lifted up from below by the armpits, the upper body 94 remains tilted forward, and the waist is closer to the seat 40.

Next, the controller 71 further extends the electric cylinder 65, and the user is switched to the seated state. At this time, the user's upper body 94 is lifted up from the armpits, and the user is seated on the seat 40. The user's feet 91 are grounded, and the thighs 93 are in a substantially horizontal state.

In this way, the user can switch from the standing state to the sitting state with the assistance of the transfer assisting mechanism 60. In addition, the movement trajectory of the user at this time is the same movement trajectory as the action of the caregiver holding the user and sitting down.

As shown in FIG7 , when the user is switched from the seated state to the standing state, the support column 63 is tilted forward and the arm 62 is raised. Thus, the transfer assist mechanism 60 rises obliquely forward in a manner of lifting the user from the armpits, and the user stands up. In contrast, as shown in FIG8 , when the user is switched from the standing state to the seated state, the support column 63 is tilted backward from the forward tilted position to the rearward tilted position after the arm 62 is lowered while the support column 63 is kept tilted forward. Thus, the transfer assist mechanism 60 tilts the user's upper body 94 backward while the upper body 94 is lowered, and the user sits on the seat 40. In this way, the user's movement trajectory is different in the user's standing up action and the sitting action.

That is, the controller 71 controls the shift assist mechanism 60 so that the movement trajectory when switching from the standing state to the seated state makes the user move in a forward-leaning posture more than the movement trajectory when switching from the seated state to the standing state. In particular, the controller 71 controls the transfer assist mechanism 60 so that in the front half of the entire area of the movement trajectory when switching from the standing state to the seated state, the user is moved toward the seated state while the user is in a forward-leaning posture relative to the movement trajectory when switching from the seated state to the standing state.

This enables a natural movement when the caregiver holds the user and makes him stand up, and a natural movement when the caregiver holds the user and makes him sit down.

Next, referring to Fig. 9, the operation of the present embodiment will be described while comparing the case where the user switches from the standing state to the sitting state with the same movement trajectory as the movement trajectory when the user switches from the sitting state to the standing state with the present embodiment. The upper half of Fig. 9 shows, as a comparative example, the case where the user switches from the standing state to the sitting state with the same movement trajectory as the movement trajectory when the user switches from the sitting state to the standing state.

In the comparative example, at the start of sitting, the user's center of gravity CG is located in front of the vertical line VL. That is, the user is in a state of putting weight on the transfer assistance mechanism 60, and the user's weight is distributed and maintained under the armpits, chest, knees, and the back of the feet 91.

In the first intermediate stage, the center of gravity CG of the user is located behind the vertical line VL. Therefore, the user is in a backward leaning state, and the user's weight is supported only by the armpits and the toes of the feet 91.

In the second intermediate stage, the user's center of gravity CG is located further back than the vertical line VL. Therefore, the user may not be able to maintain the standing state by his own strength, and may feel the fear of losing balance due to bending of the knees and the fear of falling.

In this embodiment, at the start of sitting, the user's center of gravity CG is similarly located in front of the vertical line VL. That is, the user is in a state of putting weight on the transfer assistance mechanism 60, and the user's weight is distributed and maintained at the armpits, chest, knees, and the back of the feet 91.

In the first intermediate stage, the user's center of gravity CG is located in front of the vertical line VL. Therefore, the user does not lean back, and the user's weight is distributed and maintained at the armpits, chest, knees, and backs of the feet 91, as in the sitting start state.

In the second intermediate stage, the user's center of gravity CG is located at a position substantially consistent with the vertical line VL. Therefore, the user does not lean backward, and the user's weight is dispersed and maintained at the armpits, chest, knees, and the back of the feet 91 as in the first intermediate stage.

Thus, according to the present embodiment, even in the first intermediate position and the second intermediate position, the center of gravity CG of the user is not located behind the vertical line VL. Therefore, compared with the comparative example, the state in which the user can stand upright by his own strength can be maintained for a longer time. Therefore, the user will not be placed in an unstable posture when transferring. In addition, the state in which the user's weight can be distributed and maintained in the armpits, chest, knees, and the back of the feet 91 can be maintained for a long time, and the user can transfer in a form close to natural standing movements, and therefore, it also becomes a training for maintaining the user's body functions.

At this time, the position of the user's head (the position of the front end of the upper body 94) can be prevented from greatly deviating from the vertical line VL relative to the position of the knees that serve as the fulcrum for supporting the user. Therefore, the inclination angle (state inclination angle α) of the upper body 94 relative to the vertical line VL becomes smaller, thereby reducing the pressure on the chest and preventing the head from falling forward.

In addition, when getting closer to the seated state from the second intermediate position, the center of gravity CG is located behind the vertical line VL, but since the rearward tilting action is performed with the height of the center of gravity CG sufficiently lowered to near the seat 40, the user's fear of falling can be reduced.

The structure and effects of the above-described embodiment will be summarized below.

(1)(3) The wheelchair (1) comprises: a frame 10; a seat 40 having a seat surface 41 on which a user sits and mounted on the frame 10; a transfer assist mechanism 60 mounted on the frame 10 and adjusting the inclination angle and height relative to the frame 10, and assisting in switching between a standing state in which the user stands up and a sitting state in which the user sits on the seat 40; and a controller 71 for controlling the movement trajectory of the user in the transfer action while adjusting the inclination angle and height of the transfer assist mechanism 60, the controller 71 controlling the transfer assist mechanism 60 so that the movement trajectory when switching from the standing state to the sitting state allows the user to move while maintaining a forward leaning posture more than the movement trajectory when switching from the sitting state to the standing state.

According to this structure, the movement trajectory when switching from the standing state to the sitting state makes the user move in a state of leaning forward more than the movement trajectory when switching from the sitting state to the standing state, so that the state in which the user's weight can be distributed and maintained in the armpits, chest, knees, and the back of the feet 91 can be maintained for a long time. Therefore, the user will not be in an unstable posture when changing. In addition, the state in which the user's weight can be distributed and maintained in the armpits, chest, knees, and the back of the feet 91 can be maintained for a long time, and the user can change in a form close to the natural standing movement, so it also becomes a training for maintaining the user's body functions.

In addition, the position of the user's head can be kept from greatly deviating from the vertical line VL relative to the position of the knees as the fulcrum for supporting the user. Therefore, the inclination angle (state inclination angle α) of the upper body 94 relative to the vertical line VL becomes smaller, thereby reducing the pressure on the chest and preventing the head from falling forward.

(2) Preferably, the controller 71 controls the transfer assistance mechanism 60 to move the user toward the seated state while maintaining the user in a forward leaning posture, in the front half of the entire area of the movement trajectory when switching from the standing state to the seated state, relative to the movement trajectory when switching from the seated state to the standing state.

According to this structure, particularly in the front half of the entire area of the movement trajectory when the user switches from the standing state to the sitting state, the user is moved to the sitting state while being maintained in a forward leaning posture, so that the user can maintain the standing state by his own strength for a longer time.

Although the embodiment of the present invention has been described above, the above embodiment merely shows an application example of the present invention and does not intend to limit the technical scope of the present invention to the specific configuration of the above embodiment.

Claims (3)

1. A wheelchair, comprising:

A frame;

a seat having a seating surface on which a user sits and mounted on the frame;

A transfer support mechanism attached to the frame, for adjusting an inclination angle and a height with respect to the frame, and for supporting the user in a switching manner, and for supporting the user in a standing state and for supporting the user in a sitting state;

A controller for controlling a movement locus of the user during the transfer operation while adjusting an inclination angle and a height of the transfer assist mechanism,

The controller controls the transfer assist mechanism so that a movement locus when switching from the standing state to the sitting state moves in a state where the user maintains a forward-leaning posture than a movement locus when switching from the sitting state to the standing state.

2. The wheelchair of claim 1, wherein the wheelchair comprises a plurality of wheels,

The controller controls the transfer assist mechanism to move the user toward the sitting state while maintaining the user in a forward-leaning posture with respect to a movement locus when switching from the sitting state to the standing state in a first half of an entire region of the movement locus when switching from the standing state to the sitting state.

3. A control method of a wheelchair is characterized in that,

The wheelchair is provided with:

A frame;

a seat having a seating surface on which a user sits and mounted on the frame;

A transfer support mechanism attached to the frame, for adjusting an inclination angle and a height with respect to the frame, and for supporting the user in a switching manner, and for supporting the user in a standing state and for supporting the user in a sitting state;

A controller for controlling a movement locus of the user during the transfer operation while adjusting an inclination angle and a height of the transfer assist mechanism,

The controller controls the transfer assist mechanism so that a movement locus when switching from the standing state to the sitting state moves in a state where the user maintains a forward-leaning posture than a movement locus when switching from the sitting state to the standing state.