JP2000126242A - Electric wheelchair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric wheelchair which is easy to handle by easily making a small turn. SOLUTION: This wheelchair 1 is provided with a body frame 3, driving wheels 2 arranged on right/left of the frame 3, a following rear wheel 4 arranged behind the wheels 2 at the frame 3, a sheet 10 disposed on an upper side between both of the wheels 2, and a right and left pair of riding across wheels 5 arranged in front of the wheels. Thus, nearly the center of the sheet 10 can be adjusted to be at a position nearly in the center of a virtual straight line connecting the centers of both of the wheels 2 with each other and behind it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an electric wheelchair. More specifically, the present invention relates to an electric wheelchair in which a user can move forward, backward, and turn by operating his own hand.

[0002]

2. Description of the Related Art FIG.
As shown in FIG. 1, a conventional electric wheelchair 51 has a large-diameter drive wheel 53 disposed at a rear portion of a vehicle body 52 and a front wheel 54 as a small-diameter driven wheel disposed at a front portion of the vehicle body 52. Drive wheel 5
3 is connected to a motor 55 as a drive source. The front wheel 54 is rotatably mounted around its support shaft 56 so that its direction can be freely changed according to the traveling direction.

[0003] A steering box 57 is provided at the tip of a right elbow holder 56 of the vehicle body 52. The user tilts the operation knob 58 in the advancing direction (including retreat) to individually change the rotational speed of the left and right drive wheels 53 to move the electric wheelchair 51 forward, turn, and retreat. Further, the moving speed is also changed.

Extending forward from between the left and right front wheels 54 is a so-called riding wheel 59, which is arranged at a position floating above the ground and acts when riding over a step on the ground. is there. A foot step 60 for placing a user's foot is disposed further forward of the overriding wheel 59. The foot step 60 has a step plate 62 rotatably attached to each of left and right arms 61 extending forward. The step plate 62 is rotatable around the arm 61 in the left-right direction from a substantially horizontal use position to a substantially vertical non-use position.

The overall shape of the electric wheelchair 51 is the same as that of a manual wheelchair, and a seat 63 for a user to sit on is fixed at an intermediate position between the drive wheel 53 and the front wheel 54. That is, the center of the seat 63 is located considerably ahead of the axle (not shown) of the drive wheel 53. On the other hand, since the electric wheelchair 51 turns due to the difference between the rotational speeds of the left and right drive wheels 53, the vehicle body 52 may turn around the center point between the two drive wheels 53 (the center point of the drive wheel axle). . Therefore, at the time of such turning, the user is also turned at a certain radius around the center point of the drive wheel axle,
Moreover, at this time, the user is facing outward in the radial direction of his or her turning circle.

As a result, the operation becomes difficult when the user rides on the electric wheelchair 51 in a narrow and curved passage, or when the vehicle detours around an obstacle by a small turn. That is, when turning the electric wheelchair 51, it is difficult to instantaneously predict where the next position and direction will be, and it is far from the ideal to treat the electric wheelchair 51 like one's own limbs. . In other words, for example, a large truck or bus with front wheels located behind the driver's seat,
In particular, it has a similar sensation, with varying degrees of difficulty in turning with a small radius.

However, when turning the vehicle body with a large turning radius, the above problem does not occur noticeably.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and a convenient electric wheelchair capable of instantly predicting the next position and direction of a user when the user turns the vehicle body. It is intended to provide.

[0009]

The electric wheelchair of the present invention comprises:
A main body, electric driving wheels disposed on the left and right sides of the main body, a driven wheel disposed on the rear side of the driving wheels on the main body, and disposed above and behind the two driving wheels on the main body. And the rotation ratio of the two drive wheels can be freely changed.

Therefore, the user seated on the seat is located on the middle between the two drive wheels or behind it. That is, when the electric wheelchair is turned around the midpoint between the two driving wheels, the user is located on or behind the turning center. As a result, the electric wheelchair turns around the user's body or turns around a position slightly forward of the user's body. Then, the user can change his / her position during and after turning.
The direction can be predicted instantaneously, making it easier to handle.

By disposing a pair of left and right stepping wheels in front of the driving wheels in the main body such that the lower ends thereof are located above the lower ends of the driving wheels, the stepping over the steps is facilitated. Naturally, the driven wheels are arranged rearward with the driving wheels in the middle, and the stepping over wheels are arranged in front of the wheels, so that the wheels are stabilized. Since the right and left wheels are a pair of right and left wheels, the vehicle body is stable when the vehicle gets over a step, and the vehicle body is stably supported when the vehicle is tilted forward with the drive wheel as a fulcrum.

Further, the seat is mounted so that its center substantially corresponds to substantially the center of an imaginary straight line connecting the centers of the two drive wheels, thereby turning the vehicle body so that the vehicle body itself becomes the center. When turning, the user always turns around the user himself or herself. Therefore, even when the turning radius is small, it is easy to handle as described above.

Further, by mounting the seat so that the position in the front-rear direction with respect to the main body can be adjusted, the user can select a seating position with respect to the center of rotation in accordance with his / her physique.

In addition, a footstep for placing a user's foot between the pair of left and right wheels for climbing over a step is disposed, and the footstep swings upward and is housed in the main body. With this configuration, it is possible to prevent the footstep from being disturbed by storing the footstep when the user gets on and off the vehicle. In addition, it can be disposed forward without interfering with the wheel over the step.

Further, a drive wheel support arm and a climbing wheel arm are provided, the rear end of the drive wheel support arm is elastically attached to the main body frame, the vicinity of the front end is rotatably supported on the main body frame, and the intermediate portion is driven. By disposing a wheel, rotatably supporting the rear end of the overcoming wheel arm to the main body frame, arranging the overcoming wheel at the front end, and elastically attaching the intermediate portion to the front end of the driving wheel support arm. When the overcoming wheel runs over the step, a downward pressing force acts on the drive wheel, so that the ground contact force is maintained. As a result, high traveling performance is obtained even when traveling on a step.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an electric wheelchair according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a perspective view showing an embodiment of the electric wheelchair of the present invention. FIG. 2 is a sectional view showing a semi-disassembled state of the electric wheelchair of FIG. FIG. 3 is a perspective plan view of the electric wheelchair of FIG. FIG. 4 is a side view showing an example showing a main part of the electric wheelchair of FIG.

In the electric wheelchair 1 shown in FIGS. 1 to 3, the left and right large-diameter drive wheels 2 are disposed slightly forward from the center of the main body frame 3, and the rear part of the main body frame 3 has a small diameter as a driven wheel. A wheel 4 is provided, and a small-diameter stepping overwheel (hereinafter referred to as a “overriding wheel”) 5 is provided at a front portion of the main body frame 3. As shown in FIG. 2, a control box 7 is disposed on the right armrest 6 (not shown in FIGS. 1 and 3).

A drive motor (not shown) is connected to the drive wheels 2. By operating the operation knob 7a of the control box 7, the rotation speeds of the left and right drive wheels 2 are individually changed,
Thereby, the electric wheelchair 1 is moved forward, turned, and retracted. Further, the moving speed can be changed. The drive wheel 2 is elastically attached to the main body frame 3 by interposing a coil spring 8.

A body cover 9 is detachably attached to the body frame 3. Further, as shown in FIGS. 2 and 3, a boss 1 for detachably fitting the seat 10 is provided slightly behind the drive wheel shaft 2a in the main body frame 3.
1 is provided. As shown in FIG. 2, a shaft member 12 that is inserted into the boss 11 is attached to a lower surface of the sheet 10. A mounting bolt 13 protruding from the upper surface of the shaft member 12 is rotatably mounted on the shaft member 12. On the other hand, a plate member 14 in which a plurality of nuts 14a are embedded is provided on the lower surface of the seat 10. By doing so, the longitudinal position of the shaft member 12 with respect to the seat 10 can be changed and adjusted, and as a result, the longitudinal position of the seat 10 with respect to the main body frame 3 can be changed and adjusted. The seat 10 is not limited to the bolts 13 and the nuts 14a but can be attached to the vehicle body frame 3 by a known means so that the front and rear positions can be adjusted.

In the present embodiment, a front position in which the center point of the seat 10 corresponds to a position substantially corresponding to the center of an imaginary straight line L (shown by a dashed line in FIG. 3) connecting the centers of the two drive wheels 2, The adjustment can be performed between the virtual straight line L and a rear position which is an intermediate position between the rear wheel 4. Therefore, when the electric wheelchair 1 is turned around the center point of the virtual straight line L, that is, one of the right and left drive wheels is rotated in the forward direction, and the other drive wheel is rotated in the update direction at the same rotation speed. At this time, the user can turn around the user substantially (when the seat 10 is at the front position), which makes it easy to handle. When the seat 10 is at the rear position, the turning center of the electric wheelchair 1 is located in front of the user. Therefore, since the turning center exists in the field of view of the user, the direction and position of the user can be instantaneously predicted at the time of turning and the handling becomes easy.

The rear wheel 4 is rotatably mounted in a horizontal plane on a support shaft 15 formed at the rear end of the main body frame 3 (see FIG. 3). Therefore, the driving wheel 2 is adapted to rotate in the traveling direction.

Here, the attachment mechanism between the drive wheel 2 and the overriding wheel 5 will be described with reference to FIGS. FIG. 4 shows a state in which the front drive wheel 2 has been removed for clarity. The illustrated drive wheel 2 is the drive wheel on the other side.

First, a support portion 3a extending downward is projected from a front portion of the main body frame 3. As shown in FIG. The support portion 3a rotatably supports a first pin 17 rotatably supporting a part of a drive wheel support arm 16 described below, and one end of a climbing wheel arm 18 described below beneath the first pin 17. A second pin 19 is provided. The overriding wheels 5 are mounted near the front ends of a pair of left and right overriding wheel arms 18 extending forward from the main body frame 3 so as to be slightly above the lower ends of the driving wheels and the rear wheels. The intermediate portion of this overcoming wheel arm 18 is a coil spring 2
0, it is elastically attached to a front end portion of a drive wheel support arm 16 to be described later, and a rear end is pivotally supported by the support portion 3a by the second pin 19. Therefore, when the overcoming wheel 5 runs over a step, the overcoming wheel arm 1
8 is swung upward with the second pin 19 as a fulcrum.

On the other hand, the rear end of the drive wheel support arm 16 is attached to the main body frame 3 via the coil spring 8, and the portion behind the front end is pivoted to the support portion 3 a by the first pin 17. Supported. Further, the axle of the drive wheel 2 is mounted between the portion of the coil spring 8 in the drive wheel support arm 16 and the pivot portion 17 by the first pin. Therefore, the driving wheel support arm 1
When the front end of 6 is pushed upward with the first pin 17 as a fulcrum, the drive wheel 2 is lowered, and when the front end is pushed down, the drive wheel 2 is raised.

With this configuration, as shown in FIG. 4, when the overriding wheel 5 rides on the step H, the front end of the overriding wheel arm 18 is pushed upward, so that the driving wheel 2 is driven by a downward pressing force. The contact force of the wheel 2 is maintained.
As a result, high traveling performance is obtained even when traveling on a step. In FIG. 4, the state in which the drive wheel 2 is pushed down is indicated by a two-dot chain line. However, the coil 8 is not actually lowered, and the coil 8 is compressed, thereby preventing the drive wheel 2 from reducing the force pressing the ground. It is.

As shown in FIG. 3, a footstep 21 is provided between the pair of overriding wheels 5 so that the user can place his or her feet. As shown in FIG. 2, the foot step 21 is swingably attached to the tip of a substantially L-shaped arm 22 that projects forward from the front of the main body frame 3. Then, it is swung upward from a substantially horizontal state of use, and is housed from a substantially vertical position toward the body frame 3.

When the user gets on the electric wheelchair 1, he or she generally sits on the seat with the footstep 21 stored therein, and then swings it to the use state. However, there is a case where the foot step 21 is leveled and the rider puts his foot on the foot step 21 and tries to ride. At this time, even if the electric wheelchair 1 tilts forward and downward with the driving wheel 2 as a fulcrum, the left and right riding wheels 5 land and the riding wheel 5
And the drive wheel 2 that does not rotate carelessly is supported at four points, thereby stabilizing it. This is the conventional electric wheelchair 5 shown in FIG.
When the vehicle 1 is tilted forward and downward in the same state, the front wheel (driven wheel) 54 that is rotatable serves as a fulcrum, and
This is in contrast to the instability supported by the 9.

In FIG. 1, an operation lever indicated by reference numeral 23 is for rotating the seat 10 for the convenience of the user getting on and off.

[0030]

According to the present invention, the user seated on the seat is located on the middle between the two drive wheels or behind it. That is, when the electric wheelchair is turned around the midpoint between the two drive wheels and at a small radius close thereto, the user is located on or behind the turning center. As a result, the electric wheelchair turns around the user's body or turns around a position slightly forward of the user's body. Then, the user can instantly predict his / her own position and direction during and after the turn, which makes the user easy to handle.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an electric wheelchair of the present invention.

FIG. 2 is a side view showing a semi-disassembled state of the electric wheelchair of FIG.

FIG. 3 is a perspective plan view of the electric wheelchair of FIG. 1;

FIG. 4 is a side view showing an example showing a main part of the electric wheelchair of FIG. 1;

FIG. 5 is a perspective view showing an example of a conventional electric wheelchair.

[Explanation of symbols]

 1 ··· Electric wheelchair 2 ··· Drive wheel 3 ··· Main frame 3a · · · Support 4 · · · Rear wheel 5 · · · Override wheel 6 · · · elbow rest 7 · ··· Control box 8 ··· Coil spring 9 ··· Body cover 10 ··· Seat 11 ··· Boss 12 ··· Shaft member 13 ··· Mounting bolt 14 ··· Plate member 15 ··· Support shaft 16 ··· Drive wheel support arm 17 ··· First pin 18 ······ Covering wheel arm 19 ····· Second pin 20 ··· Coil spring 21 .... Foot step 22 ... Arm 23 ... Operation lever

Claims (6)

[Claims] 1. A main body, driving wheels disposed on the left and right sides of the main body, a driven wheel disposed behind the driving wheels on the main body, and above and behind both driving wheels on the main body. The electric wheelchair is configured to be able to freely change the rotation ratio of the two drive wheels. 2. The electric wheelchair according to claim 1, wherein a pair of left and right stepping wheels is disposed in front of the drive wheels in the main body such that a lower end thereof is located above a lower end of the drive wheels. 3. The electric wheelchair according to claim 1, wherein the seat is mounted such that a substantially center of the seat corresponds to a substantially center of a virtual straight line connecting centers of both driving wheels. 4. The seat according to claim 1, wherein the seat is mounted so as to adjust a position in a front-rear direction with respect to the main body.
The electric wheelchair according to any one of the above. 5. A foot step for placing a user's foot between the pair of left and right stepping wheels is provided, and the foot step swings upward and is housed in the main body. The electric wheelchair according to any one of claims 1 to 4, wherein the electric wheelchair is adapted to be driven. 6. A drive wheel support arm and a climbing wheel arm, wherein a rear end of the drive wheel support arm is elastically attached to the main body frame, and a front end vicinity is rotatably supported by the main body frame. A driving wheel is disposed at an intermediate portion, a rear end of the riding wheel arm is rotatably supported by the main body frame, a riding wheel is disposed at a front end, and the intermediate portion is a front end of the driving wheel support arm. The electric wheelchair according to any one of claims 1 to 5, wherein the electric wheelchair is elastically attached to the wheelchair.