Electric wheelchair

Abstract

To provide an electric wheelchair capable of not only traveling in a flat land but also going up and down stairs and being compact.SOLUTION: An electric wheelchair includes: a chair part; a pair of main wheels and a pair of auxiliary wheels arranged on both sides of the chair part; a pair of front crawlers moving in a vertical direction by a vertical cylinder in the inside of the pair of main wheels and the pair of auxiliary wheels; and a pair of rear crawlers rotating toward a rear lower side with a rear part side of the front crawlers as an axis by an inclination cylinder extending rearward of the chair part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electric wheelchair that can ascend and descend stairs. [Background technology]

[0002] For example, as disclosed in Patent Document 1, a wheelchair stair climbing machine is known in which a wheelchair platform for carrying a wheelchair is attached to a self-propelled body that has crawlers and can ascend and descend stairs. This meant that the wheelchair had to be placed on the elevator and secured each time the wheelchair went up or down the stairs, meaning that the wheelchair user could not go up or down the stairs without the assistance of a caregiver, which placed a heavy burden on both the user and the caregiver. Furthermore, when the elevator is not being used to ascend or descend stairs, it must be stored, posing a space problem. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 2551862 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a compact electric wheelchair that can not only travel on flat ground but also climb stairs. [Means for solving the problem]

[0005] The electric wheelchair of the present invention is characterized by having a seat portion, a pair of main wheels and a pair of auxiliary wheels arranged on either side of the seat portion, a pair of front crawlers that move up and down inside the pair of main wheels and pair of auxiliary wheels by up and down cylinders, and a pair of rear crawlers that rotate toward the rear and lower side around an axis on the rear side of the front crawlers by inclined cylinders that extend rearward beyond the seat portion.

[0006] When the electric wheelchair is normally traveling on flat ground, the front crawlers can be stored inside the pair of main wheels and the pair of auxiliary wheels so as to be close to the seat section, and the electric wheelchair can travel with the rear crawlers folded on the back side of the seat section, so that the electric wheelchair becomes compact, while the front and rear crawlers can be used when going up and down stairs.

[0007] In the present invention, the front crawler preferably has a first vertical cylinder that expands and contracts in the vertical direction, and a second vertical cylinder located rearward of the first vertical cylinder. For example, the first upper and lower cylinder may be fixed to approximately the center of the front crawler or forward of approximately the center, and the second upper and lower cylinder may be fixed to the rear of the front crawler, and the vertical heights of the front and rear of the front crawler may be changed by extending and contracting the first upper and lower cylinder and the second upper and lower cylinder.

[0008] In the present invention, the seat portion preferably has a seat cylinder for adjusting the angle of the seat surface. This makes it easier to keep the chair at a constant angle that is suitable for moving up stairs. [Effects of the Invention]

[0009] The electric wheelchair of the present invention can not only travel on flat ground under normal circumstances but also climb stairs.When the wheelchair is not in use or is otherwise compact, it can climb stairs in a stable manner using two different types of crawlers. Such an electric wheelchair allows the user to use it with as little assistance as possible from a caregiver. [Brief explanation of the drawings]

[0010] [Figure 1] 1 shows a front view of an electric wheelchair according to the present invention. [Figure 2] A side view is shown. [Figure 3] FIG. 2 is a rear perspective view showing the rear crawler and the front crawler in a substantially horizontal state. [Figure 4] FIG. 10 is a rear perspective view showing the rear crawler in a folded state. [Figure 5] 1(a) to 1(c) are explanatory diagrams for explaining how an electric wheelchair goes up and down stairs. [Figure 6] (d) to (f) are explanatory diagrams for explaining how an electric wheelchair goes up and down stairs. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 4 show an example of the structure of an electric wheelchair 1 according to the present invention, and FIGS. 5 and 6 are explanatory diagrams for explaining its movement up and down stairs. The wheelchair 1 comprises a seat 2 on which the user sits, a pair of main wheels 3 and a pair of auxiliary wheels 4, and further comprises a pair of front crawlers 5 and a pair of rear crawlers 6 used when ascending and descending stairs. Hereinafter, in this specification, the front direction refers to the front side of a user sitting on the chair portion 2, and the rear direction refers to the back side of the user.

[0012] A front view of the wheelchair 1 is shown in FIG. 1, a side view in FIG. 2, and rear perspective views in FIGS. In this embodiment, as shown in Figure 2, a back frame 11 is erected on the rear side of a bottom frame 10 extending in the front-to-rear direction, and the middle part of the longitudinal direction of the back frame 11 and the upper part of a front frame 12 erected on the front side of the bottom frame 10 are connected by a connecting frame 13. The pair of left and right main wheels 3 are respectively positioned below the pair of left and right back frames 11 and are driven by wheel motors (not shown). The pair of left and right auxiliary wheels 4 are rotatably provided on the lower sides of the pair of left and right front frames 12, respectively. The wheel motors, crawler motors (described later), cylinders, etc. can be controlled via operation units such as a controller 7 and lever 8 connected by wire or wirelessly. There is no restriction on the location or number of the operating units, as long as the user can at least touch them while sitting on the chair 2. This allows the user to use the wheelchair 1 with as little assistance as possible from a caregiver. For example, the controller 7a provided at a position within reach of the right hand of a user sitting on the chair 2 may be used to drive the main wheels 3 (wheel motors), and the lever 8a may be used to operate the direction of movement of the wheelchair 1, etc. In addition, the upper side of the back frame 11 has a handle 9 that an attendant can use to move the wheelchair 1 from behind, but there may also be a controller 7b or lever 8b below the handle 9 that can be operated by the attendant. Also, a control unit may be provided to enable overall control of each motor, cylinder, etc.

[0013] As shown in FIG. 1, the chair portion 2 has a seat cylinder 14 for adjusting the angle of the seat surface. The seat cylinder 14 has one end attached to the bottom surface 10a supported by a pair of left and right bottom frames 10, etc., and the other end attached to the seat 15 located above the bottom surface 10a.Details will be described later, but as shown in Figure 6(d), etc., the seat 15 can be adjusted to an angle suitable for moving up stairs. In this embodiment, a chair seat 2a made of cloth, synthetic resin, etc. is provided between the back frame 11 and the bottom frame 10 so as to cover the seat portion 15, and when viewed from the front, the seat cylinder 14 and the bottom portion 10a are hidden by the hanging lower part of the chair seat 2a. The battery (not shown) is disposed on the bottom surface 10a, for example. The battery supplies power to each motor, cylinder, operating unit, etc. A footrest 17 on which the user places his / her feet is provided at the tip of a footrest cylinder 16 fixed to the front frame 12 side. When a user gets on or off the vehicle, the pair of left and right footrest cylinders 16 can be extended to bring the footrests 17 closer to the ground, and when traveling, the footrest cylinders 16 can be retracted to keep the footrests 17 in a higher position.

[0014] The wheelchair 1 moves on approximately flat ground by rotating the main wheels 3 and auxiliary wheels 4, but when going up and down stairs, it uses the front crawlers 5 and rear crawlers 6. The pair of left and right front crawlers 5 are located below the seat portion 2 and inside the pair of main wheels 3 and the pair of auxiliary wheels. The front crawler 5 has a driving wheel 52 and a driven wheel 53 supported by a crawler frame 51 extending in the front-rear direction, and a belt 54 wound between them, and is driven by a crawler motor (not shown). The pair of front crawlers 5 may have a pair of drive wheels 52 connected by a shaft, or each drive wheel 52 may be independently driven to rotate. The front crawler 5 is provided with upper and lower cylinders so that the underside of the belt 54 can come into contact with stairs when ascending or descending stairs, and is kept above the ground when traveling on flat ground. This embodiment has a first vertical cylinder 18 that expands and contracts in the vertical direction, and a second vertical cylinder 19 located behind the first vertical cylinder. The first vertical cylinder 18 has one end attached to the approximate center or front side of the crawler frame 51, and the other end attached to the bottom frame 10 or the connecting frame 13 vertically above it. On the other hand, one end of the second upper and lower cylinder 19 is attached to a connecting portion 56 that connects the rear portions of a pair of crawler frames 51, and the other end is attached to the back frame 11 side (for example, a connecting portion connected to a pair of left and right back frames 11). In this way, since the front crawler 5 has two first and second upper and lower cylinders 18, 19 spaced apart in the front-to-rear direction, it becomes easier to place only the front part of the front crawler 5 on the stairs, as shown in Figure 5(b), details of which will be described later.

[0015] The pair of left and right rear crawlers 6 are located behind the pair of front crawlers 5, respectively. As shown in FIG. 3, the rear crawler 6 has a belt 64 wound between a driving wheel 62 and a driven wheel 63 supported by a crawler frame 61, and is provided with a crawler motor that drives the driving wheel 62. The rear crawler 6 is equipped with a tilt cylinder 20 . In this embodiment, one end of the inclined cylinder 20 is attached to a connecting portion 66 that connects the approximate center portions of a pair of crawler frames 61, and the other end of the inclined cylinder 20 is attached to the back frame 11 side. A support portion 55 is provided on the crawler frame 51 of the front crawler 5 so as to protrude slightly rearward, and a connecting shaft 65 that connects the front portions of a pair of crawler frames 61 is rotatably held on this support portion 55. As a result, when the inclined cylinder 20 extends, the rear portion of the rear crawler 6 moves rearward and downward around the connecting shaft 65 as an axis. Conversely, when the inclined cylinder 20 is retracted, the rear part of the rear crawler 6 moves forward and upward around the connecting shaft 65, so that the rear crawler 6 can be folded so as to approach the back of the seat part 2 as shown in Figure 4.

[0016] 5 and 6, the wheelchair 1 will be described as it ascends and descends stairs. FIG. 5(a) shows the wheelchair 1 when traveling on flat ground. When the robot is normally traveling on flat ground, the main wheels 3 and auxiliary wheels 4 are in contact with the ground to maintain the posture of the chair part 2, and the front crawler 5 and rear crawler 6 are floating above the ground. At this time, the first and second upper and lower cylinders 18, 19 are retracted so that the front crawler 5 is brought close to the bottom frame 10, etc., and the inclined cylinder 20 is retracted so that the rear crawler 6 is folded toward the back side of the chair part 2, making the wheelchair 1 compact. Well-known distance sensors such as laser, ultrasonic, and reflected light type may be provided near the main wheels 3, auxiliary wheels 4, front crawlers 5, and rear crawlers 6. For example, as shown in FIG. 1, a sensor 21 may be provided near the training wheels 4 to detect the approach of stairs, and the sensor data may be sent to the control unit, which may automatically control the rotation of the main wheels 3 to stop. Furthermore, the wheelchair 1 may be able to ascend and descend stairs in a semi-automatic mode that uses the results from the sensors to drive the motors and cylinders.

[0017] As shown in Figure 5(b), by extending the inclined cylinder 20 to unfold the rear crawler 6, and extending the second upper and lower cylinder 19 more than the first upper and lower cylinder 18 to move the rear part of the front crawler 5 downward, the front part of the front crawler 5 can be placed on a staircase, for example, on the top surface of the first step. As shown in FIG. 5(c), the upper and lower cylinders are further extended to move the rear of the front crawler 5 further downward, and the inclined cylinder 20 is extended to bring the rear crawler 6 into contact with the ground. This causes the main wheels 3 and auxiliary wheels 4 to lift off the ground.

[0018] As shown in FIG. 6(d), the wheelchair 1 moves forward by being driven by the crawlers 5 and 6. Specifically, the robot starts climbing the stairs with the front crawler 5 while the rear crawler 6 is in contact with the ground. At this time, the chair part 2 is kept at a constant angle suitable for moving up stairs by operating the seat cylinder 14 to extend and adjusting the angle of the seat part 15 relative to the bottom part 10a so that the seat part 15 is relatively close to horizontal. For example, an angle sensor may be provided, and the seat cylinder 14 may be controlled based on the data to adjust the seat 15 to a desired angle. This makes it easier to prevent the user from feeling uncomfortable due to the chair part 2 being tilted significantly backward. As shown in FIG. 6(e), the front crawler 5 and rear crawler 6 are adjusted in a substantially horizontal position while the amount of expansion and contraction of each cylinder is adjusted, and the robot ascends the stairs. In this way, while moving on the stairs, the main wheels 3 and the driven wheels 4 are in a floating state and do not come into contact with the stairs. As shown in FIG. 6(f), when the robot advances to the top of the stairs, the main wheels 3 and auxiliary wheels 4 are placed on the ground, and the front crawler 5 and rear crawler 6 are stored in the state shown in FIG. 5(a). For example, it is possible to go down stairs by going from state (f) to state (e) in Figure 6 and then to state (d). [Explanation of symbols]

[0019] 1 electric wheelchair 2. Chair 3 main wheels 4 Training wheels 5 Front crawler 6 Rear crawler

Claims

1. An electric wheelchair comprising: a seat portion; a pair of main wheels and a pair of auxiliary wheels arranged on either side of the seat portion; a pair of front crawlers that move up and down inside the pair of main wheels and the pair of auxiliary wheels by up and down cylinders; and a pair of rear crawlers that rotate rearward and downward around an axis on the rear side of the front crawlers by inclined cylinders that extend rearward beyond the seat portion.

2. 2. The electric wheelchair according to claim 1, wherein the front crawler has a first vertical cylinder that extends and contracts in the vertical direction, and a second vertical cylinder located rearward of the first vertical cylinder.

3. The electric wheelchair of claim 2, wherein the first upper and lower cylinder is fixed to approximately the center of the front crawler or forward of the approximately center, and the second upper and lower cylinder is fixed to the rear of the front crawler, and the vertical heights of the front and rear of the front crawler can be changed by extending and contracting the first upper and lower cylinder and the second upper and lower cylinder.

4. 4. The electric wheelchair according to claim 1, wherein the seat portion has a seat cylinder for adjusting the angle of the seat surface.

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