Electric assist device for car seats

Abstract

Even when the wheelchair is moving electrically, the risk of danger from the user touching the handrim of the rear wheel is eliminated. [Solution] The wheelchair 10 comprises an electric motor 25, a drive wheel 26 driven by the electric motor 25, a battery 24 that supplies power to the electric motor 25, a frame structure 22 on which the electric motor 25, the drive wheel 26, and the battery 24 are mounted, a mounting bar 40 that protrudes in one direction from the frame structure 22 and is positioned below the tipping lever 16 of the push wheelchair 10, and a fixing device 50 for fixing the mounting bar 40 to the tipping lever 16. The wheelchair 10 is designed so that when the mounting bar 40 is positioned below the tipping lever 16, the drive wheel 26 touches the ground, but the rear wheels 12 of the push wheelchair 10 do not touch the ground.

Description

Technical Field

[0001] The present invention relates to an electric assist device for wheelchairs that can be easily attached to wheelchairs.

Background Art

[0002] As a general method of using a wheelchair, there are cases where the wheelchair user (hereinafter simply referred to as the user) turns the wheels himself / herself to move, and there are also cases where the caregiver pushes the wheelchair from behind to move. In either case, on slopes or unpaved roads, the burden on the user and the caregiver becomes extremely large, and it has been difficult to move a wheelchair on slopes or unpaved roads.

[0003] Therefore, for example, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2016-150077) discloses an electric assist device including an electric motor, a drive wheel rotated by the electric motor, and a battery serving as a power source for the electric motor, which can be easily attached to and detached from a wheelchair.

[0004] Further, Patent Document 2 (Japanese Unexamined Patent Application Publication No. 2009-131471) discloses a wheelchair drive electric unit including a handle post removably connected to the rear of a wheelchair, a handle attached to the upper end of the handle post, an electric drive device supported by the lower end of the handle post, a drive wheel supported by the electric drive device and rollable on the road surface by the electric drive device, and a battery supported by the handle post and capable of supplying power to the electric drive device, which can convert the wheelchair into an electric type.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

[0006] In the electric assist devices disclosed in Patent Documents 1 and 2, both the rear wheels of the wheelchair and the electric drive wheels are in contact with the road surface. However, even when the wheelchair is moving electrically, if the rear wheels are in contact with the ground, the rear wheels will also rotate. This presents a challenge because it could be dangerous if the user unintentionally touches the handrims of the rear wheels.

[0007] Therefore, the present invention has been made to solve the above problems, and its objective is to provide an electric wheelchair assist device that can electrically assist a wheelchair in which there is no danger even if the user touches the handrim of the rear wheel of the wheelchair. [Means for solving the problem]

[0008] The electric assist device for wheelchairs according to the present invention comprises an electric motor, a drive wheel driven by the electric motor, a battery that supplies power to the electric motor, a frame structure on which the electric motor, the drive wheel, and the battery are mounted, a mounting bar that protrudes in one direction from the frame structure and is positioned below the tipping lever of a push-type wheelchair, and a fastener for fixing the mounting bar to the tipping lever, wherein when the mounting bar is positioned below the tipping lever, the drive wheel is in contact with the ground, and the rear wheels of the push-type wheelchair are not in contact with the ground. By adopting this configuration, when an electric wheelchair assist device is attached to a manual wheelchair, the rear wheels of the manual wheelchair are lifted off the ground, while the drive wheels of the electric wheelchair assist device make contact with the ground. Therefore, while the manual wheelchair is being moved by the electric wheelchair assist device, the rear wheels of the manual wheelchair do not rotate, so even if a user touches the handrim of the rear wheel, they will not be caught in the rotation, thus avoiding danger.

[0009] Furthermore, the upper surface of the mounting bar is characterized by having a groove formed therein for accommodating the lower part of the tipping lever. This configuration allows the tipping lever and mounting bar to be fixed in a stable position.

[0010] Furthermore, the drive wheels are provided at two locations, left and right, and each drive wheel is driven by a separate electric motor. This configuration allows each drive wheel to be controlled independently, enabling electric-powered maneuvers such as turning left or right and making U-turns.

[0011] Furthermore, the electric motor is characterized by being an in-wheel motor. This configuration allows for miniaturization of the entire device.

[0012] Furthermore, the wheelchair is characterized by comprising a remote control switch for indicating the direction of movement of the push-type wheelchair, and a control unit electrically connected to the remote control switch for individually driving and controlling each of the electric motors based on the instructions of the remote control switch. With this configuration, the user or caregiver can control the direction of movement of the push-type wheelchair by operating a remote control switch.

[0013] Furthermore, the rear end of the frame structure is provided with an auxiliary wheel that rotates freely and is positioned so as not to come into contact with the ground when the mounting bar is positioned below the tipping lever. This configuration allows for the attachment of auxiliary wheels to the electric wheelchair assist device when it is detached from a manually operated wheelchair, making it easier to move the electric wheelchair assist device on its own. [Effects of the Invention]

[0014] According to the electric assist device for wheelchairs of the present invention, even when the wheelchair is moving electrically, it is possible to eliminate the risk of danger even if the user touches the handrim of the rear wheel of the wheelchair. [Brief explanation of the drawing]

[0015] [Figure 1] It is a perspective view showing a place where an electric assist device for a wheelchair is attached to a manually operated wheelchair. [Figure 2] It is a rear view showing a place where an electric assist device for a wheelchair is attached to a manually operated wheelchair. [Figure 3] It is a side view showing a place where an electric assist device for a wheelchair is attached to a manually operated wheelchair. [Figure 4] It is a bottom view showing a place where an electric assist device for a wheelchair is attached to a manually operated wheelchair. [Figure 5] It is an explanatory view regarding the grounding of the rear wheels of a manually operated wheelchair and the drive wheels of an electric assist device for a wheelchair. [Figure 6] It is a control block diagram of an electric assist device for a wheelchair.

Mode for Carrying Out the Invention

[0016] The electric assist device for a wheelchair of the present embodiment (hereinafter simply referred to as an electric assist device) will be described below based on the following drawings. Note that, regarding the manually operated wheelchair (hereinafter simply referred to as a wheelchair), only a part of the configuration is illustrated without showing the whole. In particular, only one side of the rear wheels is illustrated.

[0017] The wheelchair 10 can adopt a general manually operated wheelchair. The wheelchair 10 has rear wheels 12 arranged at two positions on the left and right, handrims 13 arranged outside each rear wheel 12 for the user to hold by hand and rotate the rear wheels 12, front wheels 14 arranged at two positions on the left and right, and two tipping levers 16. Each tipping lever 16 extends from the front to the rear and is a rod-shaped member used when a caregiver presses down the rear end with the foot to lift the front wheels 14 to climb a step.

[0018] The electric assist device 20 is provided with a frame structure 22, a battery 24, and two drive wheels 26 each having an in-wheel motor 25. Each drive wheel 26 is equipped with an in-wheel motor 25. The in-wheel motor 25 is configured with an electric motor and a reduction gear integrated and arranged inside the wheel of the drive wheel 26, allowing each drive wheel 26 to be controlled individually and enabling miniaturization.

[0019] Furthermore, the in-wheel motor 25 is equipped with an electromagnetic brake function, and when the drive wheels 26 are stopped, the electromagnetic brake is always applied to the drive wheels 26. This prevents the vehicle from rolling down a slope unintentionally.

[0020] The frame structure 22 has a bottom portion 30 which is a rectangular frame when viewed from above, and two intermediate bars 32 are arranged inside the rectangular bottom portion 30, extending along the front-rear direction to support the inside of the shaft 27 of the drive wheel 26. Each drive wheel 26 is rotatably positioned between the left and right bars 30a and the intermediate bar 32 of the bottom portion 30, with the outer side of the shaft 27 supported by either of the left or right bars 30a that constitute the bottom portion 30, and the inner side of the shaft 27 supported by the intermediate bar 32.

[0021] The left and right bars 30a that make up the bottom surface 30 of the frame structure 22 protrude forward beyond the rectangle of the bottom surface 30, giving them an elongated shape. In other words, in this embodiment, the portions that extend forward from the left and right bars 30a, beyond the rectangle of the bottom surface 30, and the left and right bars 30a function as attachment bars 40 to the wheelchair 10. When attaching the electric assist device 20 to the wheelchair 10, the electric assist device 20 is inserted from the rear of the wheelchair 10 so that the mounting bar 40 is positioned below the tipping lever 16 of the wheelchair 10.

[0022] In this embodiment, the frame structure 22 employs an aluminum frame with one row of grooves and four grooves, and the structure is constructed by assembling these aluminum frames. As in this embodiment, employing an aluminum frame with one row of grooves and four grooves has the advantage that the circular tipping lever 16 fits within the groove portion 42 of the aluminum frame, allowing the tipping lever 16 and the mounting bar 40 to be fixed in a stable state. The frame structure 22 is not limited to an aluminum frame with a single row of grooves and four grooves, but it is preferable that at least the upper surface of the mounting bar 40 has a groove 42 that accommodates the lower part of the tipping lever 16.

[0023] The tipping lever 16 and the mounting bar 40 are secured by the fastener 50. The fastener 50 consists of a U-shaped member 51 and a screw 52. The tipping lever 16 and the mounting bar 40 are fixed by sandwiching the tipping lever 16 and the mounting bar 40 from the outside with the opening of the U-shaped member 51 and tightening the screw 52 provided on the upper surface of the U-shaped member 51.

[0024] In this embodiment, two fasteners 50 are provided on each side, but the number of fasteners 50 is not limited to two on each side. Also, in Figure 1, the fasteners 50 are attached near the drive wheels 26, but the fasteners 50 may be attached at a location in front of the drive wheels 26. In addition to the fastener 50, the tipping lever 16 and the mounting bar 40 may also be secured by tightening them with string, hook-and-loop fasteners, or the like.

[0025] As shown in Figures 2 and 3, when the mounting bar 40 of the electric assist device 20 is positioned below the tipping lever 16 of the wheelchair 10, the rear wheels 12 of the wheelchair 10 are configured to be lifted off the ground (floor). In other words, the diameter of the drive wheel 26 supported by the mounting bar 40 is set such that the distance h2 from the top surface of the mounting bar 40 to the ground (floor) is greater than the distance h1 from the bottom surface of the tipping lever 16 to the ground (floor) when the rear wheels 12 of the wheelchair 10 are in contact with the ground (h2 > h1).

[0026] Figure 5 shows an explanatory diagram regarding the contact between the rear wheels 12 of the wheelchair 10 and the drive wheels 16 of the electric assist device 20. Figure 5 shows an example where the mounting bar 40 is positioned at the center of the drive wheel 26. In Figure 5(a), when the electric assist device 20 is not attached to the wheelchair 10, the distance from the bottom surface of the tipping lever 16 to the ground (floor) is h1, and the distance from the top surface of the mounting bar 40 to the ground (floor) is h2.

[0027] In Figure 5(b), when the electric assist device 20 is attached to the wheelchair 10, the mounting bar 40 fits under the tipping lever 16, lifting the wheelchair 10 and causing the rear wheels 12 to lift off the ground (floor). At this time, the height of the rear wheels 12 from the ground (floor) is h2-h1. That is, if h2 > h1, the rear wheels 12 can be lifted off the ground (floor).

[0028] In this way, by attaching the electric assist device 20 to the wheelchair 10 and configuring it so that the rear wheels 12 of the wheelchair 10 are lifted off the ground (floor), the rear wheels 12 do not rotate while the wheelchair 10 is moving with the electric assist device 20. This prevents the user from getting caught in the rotation even if they touch the handrim 13 of the rear wheels 12, thus avoiding danger.

[0029] Furthermore, even if the rear wheels 12 of the wheelchair 10 are lifted off the ground (floor) while the electric assist device 20 is attached to the wheelchair 10, the front wheels 14 of the wheelchair 10 must always remain in contact with the ground.

[0030] Furthermore, a battery placement section 34 for arranging the battery 24 is provided at the top of the intermediate bar 32. The battery placement section 34 has support columns 34a that protrude upward by a predetermined length at two locations on the front and rear of each intermediate bar 32, and a placement bar 34b that extends in the front-rear direction by connecting the two support columns 34a on the front and rear of each intermediate bar 32. The battery 24 is placed on top of these two mounting bars 34b. For battery 24, it is preferable to use a lithium iron phosphate battery, which is less prone to ignition. Lithium iron phosphate batteries have the advantage of being less prone to ignition and being less expensive compared to other lithium-ion batteries.

[0031] A luggage rack 36 is provided above the battery 24. The luggage rack 36 consists of a rectangular frame 36a in plan view and support bars 36b that support the inside of the frame. The luggage rack 36 is supported by two support bars 37 that protrude upward from bars 30b that extend to the left and right on the rear side of the frame of the bottom surface 30. This luggage rack 36 is located behind the back support (not shown) that is located behind the user of the wheelchair 10, so that sufficient space is secured without interfering with the user. By providing such a luggage rack 36, the belongings of users and caregivers can be placed in a way that does not get in the way. In addition, since the luggage rack 36 covers the top of the battery 24, it also contributes to the protection of the battery 24 and the in-wheel motor 25.

[0032] Auxiliary wheels 54 are provided on the bars 30b that extend to the left and right on the rear side, forming the frame of the bottom portion 30. The auxiliary wheels 54 are freely rotatable and are positioned approximately in the center of the bars 30b. As shown in Figures 2 and 3, when the electric assist device 20 is attached to the wheelchair 10, the auxiliary wheels 54 are not in contact with the ground (floor) and are suspended above it. When the electric assist device 20 is not attached to the wheelchair 10, the electric assist device 20 can be tilted to allow the auxiliary wheels 54 to touch the ground, enabling stable movement when the electric assist device 20 is moved independently.

[0033] Furthermore, the control system of the electric assist device 20 will be explained based on Figure 6. In the electric assist device 20, the battery 24 is electrically connected to each in-wheel motor 25. Each in-wheel motor 25 is electrically connected to the control unit 60 and the remote control switch 62, and operates based on control signals from the control unit 60 when the remote control switch 62 is operated. The remote control switch 62 is equipped with a joystick 64 for indicating the direction of movement, and can be operated by the user or caregiver.

[0034] When the user or caregiver operates the joystick 64 in the direction they want to go, the control unit 60 outputs a control signal to each in-wheel motor 25 based on the movement of the joystick 64. For example, when a user or caregiver operates the joystick 64 in the forward direction, the control unit 60 outputs a control signal to each in-wheel motor 25 so that they rotate in the forward direction at the same speed. When the user or caregiver operates the joystick 64 in the reverse direction, the control unit 60 outputs a control signal to each in-wheel motor 25 so that they rotate in the reverse direction at the same speed. When the user or caregiver operates the joystick 64 in the direction of a right turn, the control unit 60 outputs a control signal that reduces the rotation speed of the right in-wheel motor 25, while keeping the rotation speed of the left in-wheel motor 25 the same in the forward direction. When the user or caregiver operates the joystick 64 in the left turn direction, the control unit 60 outputs a control signal that reduces the rotation speed of the left in-wheel motor 25, while keeping the rotation speed of the right in-wheel motor 25 the same in the forward direction.

[0035] Furthermore, the control unit 60 should control the wheelchair speed based on the amount the joystick 64 is tilted. For example, if the joystick 64 is tilted further, the control unit 60 outputs a control signal so that the rotation speed of each in-wheel motor 25 increases accordingly.

[0036] Furthermore, an indicator 66 for displaying the speed level may be provided. The indicator 66 is composed of multiple LED displays 66a. The speed level is initially set to a default value (one LED indicator 66a lights up), but the control unit 60 is configured to allow the speed level to be changed by pressing the joystick 64 for a predetermined amount of time.

[0037] When the joystick 64 is pressed for a predetermined time, the control unit 60 causes the LED indicator 66a of the indicator 66 to blink, indicating that the speed level can be changed. When the joystick 64 is moved while the LED indicator 66a of the indicator 66 is blinking, the control unit 60 increases or decreases the number of lit LED indicators 66a on the indicator 66. The more LED indicators 66a that are lit, the higher the speed level. When the joystick 64 is pressed when the desired number of LED indicators 66a are lit, the control unit 60 sets the speed level to the number of lit LED indicators 66a.

[0038] Note that the switches provided on the remote control switch 62 are not limited to the joystick 64, but may also be push-button switches for each direction, etc.

[0039] The remote control switch 62 is preferably placed within the caregiver's reach so that the caregiver can operate it, but in some cases it may be placed within the user's reach.

[0040] The control unit 60 is equipped with a main switch 68. The main switch 68 can switch the electric assist device 20 to one of three states: start, stop, or charge. When the main switch 68 is set to the activation position, electric movement becomes possible, and by tilting the joystick 64 of the remote control switch 62 in a predetermined direction, the drive wheels 26 rotate in the predetermined direction, making the wheelchair 10 movable. When the main switch 68 is set to the stop position, the electric movement stops. When the main switch 68 is set to the charging position, charging of the battery 24 becomes possible. When charging of the battery 24 is complete, the main switch 68 is returned to the stop position.

[0041] Furthermore, the configuration of this embodiment described above can also be adapted by combining it with the modifications described in the specification or other known configurations as appropriate. [Explanation of Symbols]

[0042] 10 Wheelchairs 12 Rear wheels 13 Handrims 14 Front Wheel 16 Tipping levers 20 Electric auxiliary equipment 22 Frame Structure 24 batteries 25 In-wheel motors 25 Electric motor 26 drive wheels 27 Shaft 30 Bottom part 30a Left and right bars 30b Bars extending to the left and right on the rear side 32 Intermediate bars 34 Battery placement section 34a Strut part 34b Placement bar 36 Storage 36a Frame 36b Support bar 37 Support bar 40 Mounting Bar 42 Groove 50 Fixtures 51 U-shaped member 52 screws 54 Training wheels 60 Control Unit 62 Remote control switch 64 Joystick 66 Indicators 66a LED display 68 Main switch

Claims

1. Electric motor and The drive wheels are driven by the aforementioned electric motor, A battery that supplies power to the aforementioned electric motor, A frame structure on which the electric motor, the drive wheels, and the battery are mounted, A mounting bar protrudes in one direction from the frame structure and is positioned below the tipping lever of a push-type wheelchair, The mounting bar is equipped with a fastener for fixing it to the tipping lever, An electric assist device for a wheelchair, characterized in that when the mounting bar is positioned below the tipping lever, the drive wheel is placed on the ground, but the rear wheels of the manually operated wheelchair are not placed on the ground.

2. The electric assist device for wheelchairs according to claim 1, characterized in that a groove is formed on the upper surface of the mounting bar for accommodating the lower part of the tipping lever.

3. The electric assist device for a wheelchair according to claim 1 or 2, characterized in that the drive wheels are provided at two locations on the left and right sides, and each of the drive wheels is driven by a separate electric motor.

4. The electric assist device for wheelchairs according to claim 3, characterized in that the electric motor is an in-wheel motor.

5. A remote control switch that directs the direction of movement of a manually operated wheelchair, The electric assist device for a wheelchair according to claim 3, further comprising: a control unit electrically connected to the remote control switch and which individually drives and controls each of the electric motors based on the instructions of the remote control switch.

6. The electric assist device for a wheelchair according to claim 1, characterized in that an auxiliary wheel is provided at the rear end of the frame structure, positioned so as not to come into contact with the ground when the mounting bar is positioned below the tipping lever, and which rotates freely.

Images