JPH1014987A - Auxiliary motor-driven device for wheelchair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize an auxiliary motor-driven device for a wheelchair, to make it lightweight, to stabilize position of the center of gravity, to shorten the braking distance, to improve revolutional performance, to simplify the structure and to make the price low. SOLUTION: A battery 6, a motor 7 rotated by electric power of the battery 6 and a differential gear device 9 wherein rotation of an output shaft of the motor 7 is made to be an input are fixed on a unit holder 5 which can be fitted on the back part of the body of a wheelchair 2 and ends of left and right driving shafts 11 are connected with left and right output shafts of the differential gear device 9 respectively with a universal joint 12 and a pinion 13 fixed on another end of each driving shaft 11 is made to be brought into contact with and separated from a wheel 14 fixed on a wheel 4 of the wheelchair 2 and another end of each driving shaft 11 is made to move freely up and down to the unit holder 5 by a supporting means and is energized in the direction to which the pinion 13 and the wheel 14 are brought into contact with each other and are separated from each other to constitute an auxiliart motor-driven device 1 for the wheelchair.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary electric device which can be operated by a wheelchair caregiver.

[0002]

2. Description of the Related Art As an aging society progresses, the number of caregivers (caregivers) increases as well as the number of women and elderly people.
Help for caregivers has become necessary. Under such circumstances, an auxiliary power unit of a type for adding auxiliary power to a manual wheelchair has been developed and sold in Japan and overseas.

[0003] However, the conventional auxiliary power unit has problems in structure and running performance at present, and there is room for improvement. First, in terms of structure, the total weight of the auxiliary power unit is large, the wheelchair is usually about 20 kg, and when the auxiliary power unit is attached thereto, the total weight is 4 kg.
It will be about 5Kg. For this reason, handling and operability are deteriorated. Further, unless the center of gravity of the battery or other heavy object is lowered so as not to approach the rear side, the stability of the upward inclination is deteriorated.

[0004] Next, it is difficult to operate the clutch of the driving unit, and in the tire pressing type driving unit, the running performance changes under the condition of the tire air pressure. In terms of running performance, it is necessary to control the speed so that the assistant can safely turn at the walking speed. In particular, it is necessary to eliminate the risk of overturning so that sudden braking is not applied during backward running. Regarding braking, even on a slope with a slope,
It is important to be able to brake properly.

[0005]

OBJECTS OF THE INVENTION It is an object of the present invention in view of the above,
By providing an auxiliary electric device for wheelchairs, which has the features of reducing the size and weight of the auxiliary electric device, stabilizing the position of the center of gravity, shortening the braking distance, improving turning performance, further simplifying the structure, and reducing the price. is there.

[0006]

According to the present invention, a unit holder attachable to the back of a vehicle body of a wheelchair is provided with a battery, a motor that rotates by electric power of the battery, and a rotation of an output shaft of the motor. And one end of the left and right drive shafts are connected to the left and right output shafts of the differential gear device by universal joints, and the pinions fixed to the other ends of the drive shafts are attached to the wheels of the wheelchair. Auxiliary electric motor for wheelchairs, which can be moved toward and away from the fixed wheel, and the other end of each drive shaft can be moved up and down with respect to the unit holder by support means in the direction of contact between the pinion and the wheel. Make up the device.

Here, the supporting means comprises a supporting lever which pivots up and down by a horizontal support shaft with respect to a bracket fixed to the unit holder, and a vertical support shaft which pivots by a horizontal fulcrum shaft with respect to this support lever. It comprises a support arm that moves and rotatably supports the drive shaft, and a spring that urges the support lever and the support arm upward.

A clutch lever for displacing the support lever in the upward rotation direction with respect to the bracket, an auxiliary lever for transmitting the displacement of the clutch lever to the support lever, and a support lever displaced upward in relation to a part of the support lever. A lock piece to be held and a release rod for releasing the locked state of the lock piece are provided as necessary.

[0009]

1 and 2 show a state in which an auxiliary electric device 1 for a wheelchair according to the present invention is mounted on a wheelchair 2. FIG. The auxiliary electric device 1 for a wheelchair is detachably attached to the back of the vehicle body 3 of the wheelchair 2 by a unit holder 5. And the unit holder 5
Further, a battery 6, a DC motor 7 rotated by the power of the battery 6, and a differential gear device 9 having an output rotation of the motor 7 as an input are fixed. These are wheelchair 2
Is mounted as low as possible to lower the center of gravity. Note that a control unit 27 is attached below the battery 6.

The left and right output rotations of the differential gear unit 9 are transmitted to the left and right drive shafts 11 by a universal joint 12. Each drive shaft 11 is in a state where a pinion 13 fixed to the other end can be brought into contact with and separated from a wheel 14 fixed to the wheel 4 of the wheelchair 2 by meshing or the like. The transmission of the rotational force between the pinion 13 and the wheel 14 may be performed by meshing with a gear, or the gear of the pinion 13 may be meshed with the knurled shape of the wheel 14, and further, the knurled pinion 13 and the wheel may be meshed with each other. It is also possible to transmit frictional rotational force with the rubber friction surface 14. The other end of each drive shaft 11 is supported by the unit holder 5
, And is urged in the direction of contact (engagement direction) between the pinion 13 and the wheel 14.

FIGS. 3 and 4 show a connecting portion between the DC motor 7 and the differential gear unit 9. FIG. The motor 7 is connected to the gearbox 2 of the differential gear device 9 at the mounting plate 28.
9 on the side. In this state, the motor 7
Output shaft 8 enters the inside of the gear box 29, meshes with the large gear 31 at the portion of the pinion 30, and transmits the rotation under a large reduction ratio. The gear 31 is rotatably supported by a central cylindrical shaft 32 with respect to the gear box 29, and internally supports the left and right output shafts 10 so as to be independently rotatable. The small small gears 33 and 34 and the two output gears 35 are rotatably supported.

FIG. 5 shows the meshing relationship of the gears 33, 34, 35. The gears 33 and 34 have the same number of teeth and mesh with each other. Further, one gear 33 meshes with a gear 35 that rotates integrally with the left output shaft 10, and the other gear 34 meshes with a gear 35 that rotates integrally with the right output shaft 10. Here, assuming that the rotation speed of the gear 31 is Na, the rotation speed of the left output shaft 10 is Nb, and the rotation speed of the right output shaft 10 is Nc, from the principle of the differential gear train, In the meantime, Na = (Nb + Nc) / 2
There is a relationship.

Next, FIG. 6 shows, as an example, a support portion of the drive shaft 11 on the left side. As described above, the drive shaft 1
One end of 1 is configured to transmit rotation to the output shaft 10 by a simple universal joint 12 in a state that allows vertical movement on the other end side of the drive shaft 11. The universal joint 12 here is constituted by an axially long hole formed in the output shaft 10 and a diametrical pin associated with the elongated hole. The other end of the drive shaft 11 is vertically movably supported by the support means 15.

FIG. 7 shows an example of the support means 15. The support means 15 is attached to the unit holder 5 by a bracket 16, and a support lever 18, a support arm 20, and a clutch lever 2 are provided inside the bracket 16.
3, auxiliary lever 24, lock piece 25 and release rod 2
6 and the like. In the part of the left and right brackets 16,
The support lever 18 is supported rotatably in the vertical direction by a horizontal support shaft 17, and the support arm 20 is similarly rotated in the vertical direction by a fulcrum shaft 19 horizontal to the end of the support lever 18. It is freely supported.

The support lever 18 is urged downward by a spring 21, and the support arm 20 is
It is urged upward by a spring 22. Note that these support lever 18 and support arm 20 are
The lowering limit or rotation range is regulated by stoppers 36 and 37, respectively. And the support arm 20
Each drive shaft 11 is rotatably supported by a bearing 38 at a distal end portion.

The clutch lever 23 is rotatably supported on the left and right brackets 16 by a support shaft 49, and is engaged with one end of the auxiliary lever 24 by a long hole 39 and a pin 40. The auxiliary lever 24 includes a fulcrum shaft 41
The left and right brackets 16 are rotatably supported by the left and right brackets 16.
8 correspond to the receiving pieces 43. Note that the clutch lever 23 is urged upward by a suspension spring 44.

The lock piece 25 has an L-shape, is rotatably supported by the fulcrum shaft 45 with respect to the bracket 16, and is engaged with a lock groove 47 of the support lever 18 by a spring 46. It is urged to fit. The release rod 26 corresponds to the other end of the lock piece 25, and releases the engagement between the lock piece 25 and the lock groove 47 by, for example, a manual operation in a direction in which the lock piece 25 is pushed down by the handle portion of the wheelchair 2. Move in the direction.

Next, FIG. 8 shows a connection relationship between the control unit 27, the battery 6, the motor 7, and the speed controller 48. The control unit 27 supplies the electric power from the battery 6 to the motor 7 based on the start / stop, forward / backward, and speed commands from the speed adjuster 48, starts the motor 7, and adjusts the supplied electric power. 7
To control the rotation speed of the.

Next, when the wheelchair 2 is moved forward by activating the wheelchair auxiliary electric device 1, the caregiver first pushes down the clutch lever 23 and pushes the operating piece 42 of the auxiliary lever 24 to the receiving piece 43. By pushing up while pressing, the support lever 18 is moved upward. At this time,
The lock piece 25 is pushed by the support lever 18 and pivots clockwise in FIG. 7 to allow the lock piece 25 to rise. However, the lock piece 25 is engaged with the lock groove 47 by the urging force of the spring 46, and the raised position is set. Hold.

In the raised position, the pinion 13 comes into contact with the wheel 14 by meshing or friction while transmitting torque. In addition, in this contact state, the support arm 20 is urged in the contact direction by the spring 22, so that the pinion 31 and the wheel 14
Is set to a predetermined value by the urging force of the spring 22. Therefore, depending on the weight of the user of the wheelchair 2, the body 3 of the wheelchair 2
Even if the folding direction is displaced or the frame is deformed, a predetermined rotational force can be transmitted between the pinion 13 and the wheel 14.

Here, the caregiver operates the speed adjuster 48 to move in the direction from the stop position to the start position in the forward movement state to designate a predetermined speed. At this time, the control unit 27 rotates the motor 7 at a predetermined rotation speed and rotates the gear 31 of the differential gear device 9 while reducing the speed by the output shaft 8. When there is no rotation difference between the left and right output shafts 11, that is, when the wheelchair 2 is traveling straight, the rotation of the gear 31 is transmitted to the left and right gears 35 via the small gears 33 and 34, and further, the left and right output shafts. 10, left and right drive shafts 11,
The power is transmitted to a wheel 14 integrated with the wheel 4 via a universal joint 12 and a pinion 13. Therefore, in this state, the caregiver turns the handle of the wheelchair 2 in the straight traveling direction,
The vehicle is driven forward by the auxiliary driving force of the auxiliary electric device 1, and can travel on an uphill slope or the like with a small operation force.

When the caregiver of the wheelchair 2 operates the handle of the wheelchair 2 to change its direction or turn the wheelchair 2 at the current position, the number of rotations of the wheel 4 inside the turning direction and the rotation outside the rotation direction. Since there is a difference between the rotation speeds of the wheels 4, the rotation speeds of the left and right drive shafts 11 differ by the difference. At this time, since the differential gear device 9 rotates the left and right drive shafts 11 while allowing the rotation difference, the assistant changes the direction of the wheelchair 2 or turns the wheelchair 2 at that position with a small turning radius. It can be done smoothly.

When the wheel 4 of the wheelchair 2 hits a large obstacle or the like while the wheelchair 2 is running, the rotation of the wheel 4 is stopped, so that a large load is applied to the motor 7. At this time, the pinion 13 is displaced in a direction away from the wheel 14 against the force of the spring 22 and enters a slip state, so that the motor 7 does not enter the locked state.

When the transmission of the rotational force from the auxiliary electric device 1 is interrupted in the slip state or in the non-slip state, the caregiver pushes down the release rod 26 near the handle, and locks the lock piece 25. And support lever 18
Release the lock state with. At this time, the support lever 18
Is forcibly lowered by the spring 21 and the left and right drive shafts 11 are forcibly lowered, so that the wheels 4 of the wheelchair 2 do not receive the rotational force of the auxiliary electric device 1.

The auxiliary electric device 1 is connected to the wheel 4 of the wheelchair 2.
When the wheelchair 2 enters a downhill or the like and is accelerated to a running speed or more by gravity while driving the, the caregiver sets the speed adjuster 48 to a low speed side,
The acceleration of the wheelchair 2 can be limited, and the rotational force from the auxiliary electric device 1 can be cut off by the above-described releasing operation, if necessary. If a power braking circuit is incorporated in the drive circuit of the motor 7, an electric braking force can be applied to the wheelchair 2 by utilizing the power braking function on a downhill or the like. Of course, the wheelchair 2 itself is provided with a mechanical brake means as needed.

[0026]

According to the present invention, the following effects can be obtained. Since the rotation of the left and right output shafts of the differential gear device is transmitted to the drive shaft via the universal joint, and the left and right drive shafts are supported by the support means so as to be movable in the vertical direction, the wheelchair user Even if the weight of the vehicle changes and the displacement / deformation of the vehicle body changes accordingly, the rotation of the output shaft can be reliably transmitted to the left and right wheels.

Also, since the pinion of the drive shaft is urged in the contact direction by a predetermined urging force against the wheel of the wheel by a spring, even when a large load is applied to the motor, slipping of the contact portion causes a slip. The motor is not locked, and the transmitting portion of the rotational force can be protected. In addition, since the transmission state and the interruption state of the rotational force can be selected with respect to the wheel by the displacement of the pinion, a special mechanism such as a clutch is not required, and the transmitting part of the rotational force can be simplified and reduced in weight.

Further, since the differential gear device is interposed in the transmission path of the rotational force, the direction change of the wheelchair and the turning at the current position are performed smoothly, and the operability by the person who releases the wheelchair is improved. Further, if this gear mechanism is constituted by a gear train incorporated in a large gear, the structure can be simplified and the size can be reduced, unlike the bulk differential of a general automobile. Furthermore, since the rotation of the output shaft of the motor is transmitted to a large gear under a large reduction ratio, the force applied to the gear train inside the differential gear device is small, and therefore the configuration of each gear and gear box, etc. The part can be made of a lightweight aluminum alloy or plastic, which helps to reduce the weight.

[Brief description of the drawings]

FIG. 1 is a rear view showing a state in which an auxiliary electric device of the present invention is incorporated in a wheelchair.

FIG. 2 is a side view showing a state in which the auxiliary electric device of the present invention is incorporated in a wheelchair.

FIG. 3 is a horizontal sectional view of a portion for transmitting output rotation of a motor to a differential gear device.

FIG. 4 is a sectional view of a differential gear device.

FIG. 5 is a development view of a gear train of the differential gear device.

FIG. 6 is a rear view of a portion that transmits a rotational output of the differential gear device to a drive shaft and wheels of a wheelchair.

FIG. 7 is a front view of the inside of the support means for supporting the drive shaft so as to be vertically movable.

FIG. 8 is a block diagram showing a connection relationship between a control unit, a battery, a motor, and a speed regulator.

[Explanation of symbols]

 Reference Signs List 1 auxiliary electric device for wheelchair 2 wheelchair 3 body 4 wheels 5 unit holder 6 battery 7 motor 8 output shaft 9 differential gear device 10 output shaft 11 drive shaft 12 universal joint 13 pinion 14 wheel 15 support means 16 bracket 17 support shaft 18 Support lever 19 fulcrum shaft 20 support arm 21 spring 22 spring 23 clutch lever 24 auxiliary lever 25 lock piece 26 release rod

Claims (4)

[Claims] A unit holder (5) attachable to the back of a vehicle body (3) of a wheelchair (2) includes a battery (6),
A motor (7) that rotates by the power of the battery (6), a differential gear device (9) that receives the rotation of an output shaft (8) of the motor (7) as an input, and a differential gear device (9). ), One ends of left and right drive shafts (11) are connected to universal joints (12) to left and right output shafts (10), and pinions (13) fixed to the other ends of the respective drive shafts (11).
To the wheel (14) fixed to the wheel (4) of the wheelchair (2), and the other end of each drive shaft (11) is supported by the support means (15) with respect to the unit holder (5). An auxiliary electric device (1) for a wheelchair, wherein the auxiliary electric device (1) is vertically movable and urged in a direction of contact and separation between a pinion (13) and a wheel (14). 2. A unit holder (5) attachable to the back of a vehicle body (3) of a wheelchair (2) includes a battery (6),
A motor (7) that rotates by the power of the battery (6), a differential gear device (9) that receives the rotation of an output shaft (8) of the motor (7) as an input, and a differential gear device (9). ), One ends of left and right drive shafts (11) are connected to universal joints (12) to left and right output shafts (10), and pinions (13) fixed to the other ends of the respective drive shafts (11).
To the wheel (14) fixed to the wheel (4) of the wheelchair (2), and the other end of each drive shaft (11) is supported by the support means (15) with respect to the unit holder (5). The bracket (1) is vertically movable and urges in the direction of contact and separation between the pinion (13) and the wheel (14), and furthermore, the support means (15) is fixed to the unit holder (5).
6) A support lever (18) that rotates vertically with a support shaft (17) horizontal to the support lever (18), and a support shaft (19) that rotates horizontally with respect to the support lever (18) and a drive shaft ( 1
1) A wheelchair for a wheelchair, comprising: a support arm (20) for rotatably supporting 1); and springs (21, 22) for urging the support lever (18) and the support arm (20) upward. Auxiliary electric device (1). 3. A unit holder (5) attachable to the back of a vehicle body (3) of a wheelchair (2) includes a battery (6),
A motor (7) that rotates by the power of the battery (6), a differential gear device (9) that receives the rotation of an output shaft (8) of the motor (7) as an input, and a differential gear device (9). ), One ends of left and right drive shafts (11) are connected to universal joints (12) to left and right output shafts (10), and pinions (13) fixed to the other ends of the respective drive shafts (11).
To the wheel (14) fixed to the wheel (4) of the wheelchair (2), and the other end of each drive shaft (11) is supported by the support means (15) with respect to the unit holder (5). It is movable up and down and urges in the direction of contact and separation between the pinion (13) and the wheel (14). Further, the support means (15) is horizontal with respect to the bracket (16) fixed to the unit holder (5). A support lever (18) pivoted up and down by a simple support shaft (17);
A fulcrum shaft (19) horizontal to the support lever (18)
A support arm (20) that pivots up and down to rotatably support the drive shaft (11), and a spring (2) that urges the support lever (18) and the support arm (20) upward.
1, 22), and a clutch lever (23) for displacing the support lever (18) in the upward rotation direction with respect to the bracket (16);
And the displacement of the clutch lever (23) with the support lever (1).
An auxiliary electric device (1) for a wheelchair, wherein an auxiliary lever (24) for transmitting the electric power to the wheelchair is provided. 4. A battery (6), which is attached to a unit holder (5) attachable to the back of a vehicle body (3) of a wheelchair (2).
A motor (7) that rotates by the power of the battery (6), a differential gear device (9) that receives the rotation of an output shaft (8) of the motor (7) as an input, and a differential gear device (9). ), One ends of left and right drive shafts (11) are connected to universal joints (12) to left and right output shafts (10), and pinions (13) fixed to the other ends of the respective drive shafts (11).
To the wheel (14) fixed to the wheel (4) of the wheelchair (2), and the other end of each drive shaft (11) is supported by the support means (15) with respect to the unit holder (5). It is movable up and down and urges in the direction of contact and separation between the pinion (13) and the wheel (14). Further, the support means (15) is horizontal with respect to the bracket (16) fixed to the unit holder (5). A support lever (18) pivoted up and down by a simple support shaft (17);
A fulcrum shaft (19) horizontal to the support lever (18)
A support arm (20) that pivots up and down to rotatably support the drive shaft (11), and a spring (2) that urges the support lever (18) and the support arm (20) upward.
1, 22), and a clutch lever (23) for displacing the support lever (18) in the upward rotation direction with respect to the bracket (16);
The displacement of the clutch lever (23) is determined by the support lever (1).
8), a lock piece (25) for holding the upwardly displaced support lever (18) in relation to a part of the support lever (18), and a lock piece (2).
An auxiliary electric device (1) for a wheelchair, further comprising a release rod (26) for releasing the locked state of (5).