JPH08275974A - Electric wheelchair - Google Patents

Abstract

PURPOSE: To provide an inexpensive electric wheelchair in which the actual traveling state is easily realized by detecting the manual operation torque given to a hand rim from the relative moving quantity of the hand rim with a wheel, and working a motor according to it to assist the power. CONSTITUTION: Every time when a hand rim 9 provided on a wheel 8 is manually operated, the hand rim 9 is relatively rotated to the wheel 8 against springs 32... connected to the wheel 8 by a quantity according to the operation torque within a prescribed range, and after it reaches the maximum relative rotating position for transmitting driving torque to the wheel 8, the wheel 8 is directly rotated by the hand rim 9. The operation torque given to the hand rim 9 is detected as the displacement to the wheel 8 of the hand rim 9 by a torque sensor 36 through a direction converting means 34. A motor 21 is driven according to the detected torque, and the wheel 8 is assisted and rotated by its power through a clutch 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric wheelchair for performing power assist by a driving force of a motor according to the magnitude of an operation torque applied to a hand rim.

[0002]

2. Description of the Related Art As an electric wheelchair, a completely self-propelled wheelchair is provided in which individual motors are connected to the left and right wheels, and the on / off switches of the motors are operated to allow the vehicle to run in a desired direction. Has been done. In addition to this, a power assist type in which a manual operation force is assisted by a driving force of a motor is considered and proposed.

In the fully self-propelled type, the number of rotations of the left and right motors in the forward rotation direction and the amount of operation to the rear side are controlled by the amount of operation from the neutral position of the omnidirectional operation member such as a joy stick to the front side. The rotation speed of the left and right motors in the reverse rotation direction is
Further, the rotation ratios of the left and right motors are controlled according to the amount of operation in the left and right directions, so that straight movement, backward movement, and left and right rotation can be performed.

In the power assist type, the left and right wheels are connected to the hand rim by springs, the operation torque applied to the hand rim is detected by the relative rotation amount of the hand rim with respect to the wheels, and the motor is operated according to the operation torque. The wheels are driven via the clutch to perform power assist.

[0005]

By the way, in the manual traveling type wheelchair, each of the left and right hand rims located on the outer surface side of the left and right wheels is manually operated with the left hand and the right hand at the strength and speed to the desired direction. By operating it, you can drive in the direction you want and at the speed you want. Therefore, since the actual running state is well felt from the manual operation, there is no confusion about the operation.

On the other hand, in the above-mentioned conventional self-propelled type, it is easy to operate an omnidirectional operating member such as a joystick with a fingertip or the like. However, such an operation is far from the actual traveling state as compared with the case of the manual operation type, and there is a large gap sensuously, and it takes a long time to master the operation. In addition, since the entire driving force is generated by the motor, a large-capacity motor and battery are required, and the whole becomes large and heavy. Furthermore, since the wheelchair cannot be moved at all when the battery runs out, it cannot be used, and it is inconvenient to handle when it cannot be used. Furthermore, when the vehicle runs, especially when it is stepping on the road or suddenly runs out of battery while crossing the road, it may cause a stop at such a place, which is dangerous.

On the other hand, in the above-mentioned conventional power assist type, since the driving force of the motor is transmitted by belt transmission from the drive shaft arranged in parallel with the wheel, the drive shaft and the wheel are coaxial. However, it is not structurally compatible with the manually operated type, requires a dedicated wheelchair frame that can be equipped with a motor and transmission mechanism, and is costly, and cannot be easily improved from the manually operated type. There is inconvenience. Further, the wheel and the hand rim are connected by a metal plate, and the deformation amount according to the relative rotation amount of the wheel and the hand rim of this metal plate is given to the hand rim by the electric output from the strain gauge attached to the metal plate. Since the strain gauge as a torque sensor rotates together with the wheel and the hand rim, the slip ring / brush structure is required to extract the electric output from the strain gauge. However, in this case, the structure is complicated and the life is short, so the product cost and running cost are high, and it is difficult to obtain stable output and smooth running cannot be expected.

Further, since the clutch is provided between the drive shaft and the drive pulley mounted on the drive shaft, when the clutch is disengaged to be used as a manually operated type, the wheels have a rotational load up to the drive pulley. As it is hung up, running resistance is large and it is difficult to operate manually.

An object of the present invention is to solve the above problems, and to provide an inexpensive electric wheelchair that is easy to operate, easily feels the actual running state, and is small, lightweight, highly reliable. That is the purpose.

[0010]

In order to achieve the above-mentioned object, the electric wheelchair of the present invention connects the wheel and the hand rim by a spring on the left and right, and the manual operation torque applied to the hand rim is applied to the wheel of the hand rim. It is an electric wheelchair that detects the relative movement amount with respect to the wheel and drives the wheels according to the manual operation torque to drive the wheels via the clutch to perform power assist. The drive shaft on the motor side rotates coaxially with the wheels and the hand rim. Arranged in such a manner as to be connected to the wheel via a clutch, and to the torque responsive member, a direction change means for converting the rotational displacement of the hand rim with respect to the wheel into the axial displacement of the torque responsive member located on the inner surface side of the wheel. And a torque sensor which is provided facing the fixed portion and detects the torque in response to the axial displacement of the torque responsive member. It is an aspect of the.

The clutch is a one-way clutch which is opened / closed in response to the relative rotation of the hand rim with respect to the wheel so as to be in a semi-connected state immediately before connection completion between the no-load position and the maximum relative rotation position. Is the second feature.

In the one-way clutch, a rolling member is provided between the circular outer surface on the side of the drive shaft and the polygonal inner surface on the wheel side so as to correspond to each corner of the polygonal inner surface with play therebetween. The third feature is that each rolling member is held by a retainer on the hand rim side.

In the first feature, the direction changing means is inclined in an axial direction of an inclined surface, which is partially provided on an inner circumference of the hand rim, and is inclined in a rotation direction, and an outer circumference of a cam member integrally connected to the torque responsive member. A rolling member is provided between the cam surface and the cam surface, and the rolling member is held by a retainer on the wheel side.The clutch responds to the movement of the cam shaft in the axial direction corresponding to the normal rotation direction of the hand rim, and the clutch A forward transmission one-way clutch that transmits normal rotation to the wheels, and a reverse transmission one-way clutch that transmits reverse rotation of the drive shaft to the wheels in response to movement of the cam member in the axial direction corresponding to the reverse rotation direction of the hand rim. The fourth characteristic is that the above is provided.

An electromagnet is provided on the fixed side so as to face the torque responsive member, and when appropriately energized, the torque responsive member is attracted and moved at least from the side where the forward transmission one-way clutch is in the disconnected state to the connected state. The fifth thing
It is a feature of.

Between the cam member and the forward transmission and reverse transmission one-way clutches, a position where the respective one-way clutches are moved to the rotation transmission position and held, and a position where the holding is released. A sixth feature is that a rotation transmission control member provided so as to be movable and an operation member for operating the rotation transmission control member from the outside are provided.

[0016]

In the above structure of the first feature of the electric wheelchair of the present invention, the drive shaft, the wheel and the hand rim are coaxial with each other, and the wheel is supported by using the shaft supporting portion of the wheel of the conventional manually operated frame. Since the hand rim located on the outer surface side of the vehicle can be independently rotated, and a drive shaft connected to the wheels via a clutch can be incorporated, and a motor connected to the drive shaft can also be attached, depending on the existence of the drive mechanism. The frame structure does not become particularly complicated and does not cause an increase in size, the cost can be reduced, and the frame of a conventional manual wheelchair can be used as it is for easy modification, which is convenient.

Normally, the wheels are in a stopped state by being grounded and receiving a load, and the motor is in a stopped state by no output of torque detection from the torque sensor. Each time the hand rim is manually operated in this state, the hand rim rotates relative to the wheel within a predetermined range relative to the spring connected to the wheel, by an amount corresponding to the operation torque,
After reaching the maximum relative rotation position, the vehicle is allowed to travel manually while transmitting the rotation to the wheels. At this time, the manual operation torque applied to the hand rim is detected from the relative rotation amount of the hand rim with respect to the wheel, and the motor is operated according to the manual operation torque to drive the wheel through the clutch to perform power assist. Each time the manual operation of each time ends, the hand rim is released from the manual operation and is returned to the original state from the relative rotation state with the wheel by the urging of the spring that works between the hand rim and the wheel. For this reason, as the detected manual operation torque sharply decreases and disappears, the rotation of the motor also decreases and finally the transmission of rotation to the wheels via the clutch is stopped. After that, the coasting becomes exactly the same as the manual operation type, and the speed gradually decreases. Therefore, while adopting the same operation form as the manual operation and obtaining the same running state and operation feeling as the manual operation, the power assist corresponding to the operation torque greatly reduces the manual operation force to allow easy operation and travel.

In particular, the operating torque is converted to a displacement in the axial direction of the drive shaft of the torque responsive member located on the inner surface side of the wheel by the direction changing means, and the displacement of the hand rim with respect to the wheel is located on the inner surface side of the wheel. Since the torque sensor on the fixed part is opposed to the torque responsive member so that the manual operation torque can be detected from the displacement amount of the torque responsive member, the torque sensor can be kept stopped and the output from this point can be obtained without the slip ring / brush structure. Then, the structure can be simplified and downsized, and the cost can be reduced.
Moreover, because the output is stable, smooth driving is realized.

Regardless of whether the clutch is switched between the timely connected state and the timely disconnected state electrically or mechanically, the clutch is provided directly between the wheel and the drive shaft that rotate coaxially. Since it is connected and disconnected, when it is used as a manual operation type while keeping the disconnection state, the load on the motor side is not applied at all, so it is easy to perform manual operation with low running resistance, which is advantageous when the battery runs out. Is.

In the above-mentioned configurations of the second, third and fourth features of the present invention, when the hand rim is manually operated and relatively rotates with the wheel, the one-way clutch responds to this and the connection side state is established. When the motor is driven in accordance with the manual operation torque detected at the time of the relative rotation, the unidirectional clutch changes the rotational force of the wheels in the quasi-connected state. In addition, since it works to shift this to a completely connected state and starts power assist while making a solid connection state, it is possible to smoothly transition from manual operation state to power assist state without difficulty and power assist It can be ensured to be achieved. Also, when performing manual operation type driving, if the motor is turned off and placed, the one-way clutch is a direction that escapes from the connection side between the drive shaft that is stopped and the wheels that are rotating in the running direction. Since it is only affected by the action of the hand rim, it will not be in a completely connected state, and the wheels will be rotated together by manual operation after the maximum relative rotation position with the wheel side of the hand rim without the influence of the motor side in the stopped state. Can drive. Therefore, there is an advantage that the power assist type and the manual operation type can be selectively used by a simple and inexpensive structure that does not require special control or mechanism.

Particularly in the above-mentioned configuration of the third feature of the present invention,
The timely connection and disconnection of the one-way clutch responding to the relative rotation of the hand rim causes the retainer on the hand rim side to reduce the distance between the rolling member of the one-way clutch between the circular outer surface and the polygonal inner surface at the connection position side or By moving the hand rim to the cutting position side where the interval becomes wider according to the manual operation direction, it is possible to achieve both the forward direction side and the reverse direction side.
One forward clutch can be used for both forward and reverse travel. Further, since the retainer on the hand rim side is inserted between the wheel and the drive shaft in which the one-way clutch is provided to hold the rolling member, the retainer is made to face the inner surface of the wheel by utilizing this intrusion. The connection between the hand rim side and the torque responsive member via the direction changing means can be easily achieved.

Particularly in the above-mentioned configuration of the fourth feature of the present invention,
Since two one-way clutches for forward transmission and reverse transmission are used, there is no need for a special clutch that exerts a one-way clutch function in both forward and reverse directions. Since it is mounted between the shaft and the shaft, the size of the whole does not become particularly large, and it can be made small and inexpensive.

With the above-mentioned third and fourth features of the present invention, when the wheels rotate too fast on a slope, when the hands are released from the hand rim, the relative amount of rotation between the wheels is increased. Since it becomes smaller or disappears, even if the rotation of the motor slows down or turns off and the rotation of the drive shaft exceeds the wheel, this is immediately eliminated and there is no influence on the high rotation of the wheel. Even if the motor slows down or turns off to slow down the rotation of the drive shaft, or even if the motor stops, it idles between itself and the wheels so that the rotation of the wheels is not affected. If the wheel rotation is still fast even when the motor is off, when the braking force is manually applied to the hand rim, relative rotation occurs in the opposite direction between the hand rim and the wheel, and the reverse manual operation torque at this time causes the motor to move in the opposite direction. Since it is driven to the wheel via the drive shaft and clutch, the engine brake by the reverse rotation of the motor acts on the wheel, and the rotation of the wheel can be easily and reliably reduced to the desired speed, and it can be run on slopes. It is highly safe.

In the above-mentioned structure of the fifth feature of the present invention, at least the forward transmission one-way clutch moves axially in the axial direction together with the cam member of the direction changing means to perform the connecting / disconnecting operation. Since the torque responsive member that moves in the direction of the axis is moved and moved back and forth in the axial direction by the electromagnet, it can be independently connected / disconnected in a timely manner. By driving the other side forcibly, the power assist to the left and right wheels can be started at the same time without variation, and meandering in forward traveling where at least forward rotation occurs. Can be prevented.

In the above-described structure of the sixth feature of the present invention, the rotation transmission control member is externally operated by the operating member to rotate the one-way clutches for forward direction transmission and reverse direction transmission as required. It can also be used as a completely self-propelled electric wheelchair by moving and holding it to a position, and controlling the left and right motors ON / OFF and the rotation speed with a joystick etc. with the rotation of the drive shaft being always transmitted to the wheels. It will be convenient.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the electric wheelchair of the present invention will be specifically described below with reference to the drawings.

1 to 8 show a first embodiment of the present invention. As shown in FIG. 1, the electric wheelchair of the present embodiment has basically the same frame structure and form as a conventional manually operated type wheelchair. The left and right hoods 1 and 1 that are substantially L-shaped are connected by a connecting member 26 between the horizontal portions 1a and 1a forming a rectangular frame on both vertical planes, and the seat portion 2 is provided above the horizontal portions 1a and 1a. Support and horizontal parts 1a, 1
The back part 3 is supported by the front part between the vertical parts 1b and 1b which rises at the rear part of a. A leg 4 extending downward is provided at the tip of the horizontal portion 1a, and a caster 5 is attached to the lower end of the leg 4 so that the caster 5 can be turned around a vertical axis.

A bearing member 6 is attached to the rear portion of the horizontal portion 1a of the left and right frames 1, and a plate-like or arm-like attachment member 6a integrally provided by welding or the like is welded to the horizontal portion 1a. Is mounted by using an auxiliary frame 7 that is integrally provided with the vehicle, and wheels 8 for traveling are provided by the bearing member 6.
A hand rim 9 and a drive shaft 11 (FIG. 2) are supported so as to be coaxially rotatable, and a motor 21 and a speed reducer 22 for driving the drive shaft 11 are attached.

A protective side plate 12 is provided between the horizontal portion 1a and the vertical portion 1b of the left and right frames 1 and 1 to prevent the wheel 8 from being caught, and a portion of the vertical portion 1b immediately above the protective side plate 12 is provided. An armrest 13 that projects to the front is provided. The upper end of the vertical portion 1b is a manual operation handle 14 that is bent rearward. A footrest 15 extending forward and downward is provided at the front end of the horizontal portion 1a so as to be foldable.

A controller 23 is attached to the front portion of the left frame 1 on the horizontal portion 1a side, and the horizontal portion 1 of the right frame 1 is attached.
A battery 24 is attached to the front part on the a side.

As shown in FIG. 2, the motor 21 is a flat motor and the speed reducer 22 is a flat motor. However, it goes without saying that any type and form of motor and speed reducer may be used, and in some cases, the left and right frames 1 and 1 may have a foldable structure.
In this case, the adoption of the flat motor 21 and the flat speed reducer 22 is advantageous in preventing mutual interference. For the same reason, the controller 23 and the battery 24 are also preferably flat.

The bearing member 6 of this embodiment is an annular body and has a large-diameter casing 6b inside, and a motor 21 is fitted therein, and its flange 21a is bolted to the opening portion of the casing 6a. It is installed. Bearing member 6
Has a bearing housing 6c on the outside of the motor 21
A speed reducer 22 connected to the drive shaft 1 is rotatably held via a bearing 27, and the drive shaft 1 is attached to an output shaft 22a of the speed reducer 22.
The drive shaft 11 is rotationally driven by the motor 21 at a predetermined rotation ratio by connecting 1 to each other.

The hub 8a of the wheel 8 is rotatably fitted to the drive shaft 11 via a bearing 29, and the boss 9a of the hand rim 9 is fitted to the drive shaft 11 via a clutch 31. , And the hand rim 9 are coaxially rotatable. Such a specific rotating structure on the same axis is not limited to this embodiment, and various designs can be made. Also,
The clutch 31 may be of any type such as an electrically operated one or a mechanically operated one as long as the clutch 31 is appropriately connected and disconnected.

The wheel 8 and the hand rim 9 which is coaxial with the outer surface of the wheel 8 and is positioned so as to be independently rotatable are connected by a spring 32, and the operating torque applied to the hand rim 9 is detected by the relative rotation amount of the hand rim 9 with respect to the wheel 8. ,
The clutch 21 is activated by operating the motor 21 according to this operating torque.
The wheels 8 are driven via 1 to perform power assist.

Therefore, in this embodiment, as described above, the drive shaft 11 on the side of the motor 21 is arranged so as to rotate coaxially with the wheel 8 and the hand rim 9 and is connected to the wheel 8 via the clutch 31 and then the hand rim. The torque responsive member 33 located on the inner surface side of the wheel 8 is displaced in the rotational direction of the wheel 9 with respect to the wheel 8.
Of the drive shaft 11 and the direction changing means 34 for converting the drive shaft 11 into the axial direction of the drive shaft 11, and the torque responsive member 33. The torque is detected in response to the axial displacement of the torque responsive member 33. And a torque sensor 36.

As shown in FIG. 4, the hub 8a and the boss 9a of the wheel 8 and the hand rim 9 are provided in close contact with each other, and stopper pins 41 having one end embedded and attached at a plurality of equidistant locations on the outer periphery of the hub 8a are installed. By fitting in the elongated holes 9d provided in the outer circumference of the boss 9a in the circumferential direction, the relative rotation range of the hand rim 9 with respect to the wheel 8 is restricted to a predetermined range X as shown in FIG. Prevents relative rotation of. Spring 32 is boss 9
This is a compression spring housed in an arcuate pocket 9e provided between the portion where the stopper pin 41 of a is invaded so that the axial direction is oriented in the arcuate direction. The width of the pocket 9e is larger than that of the slot 9d, and the end of the pocket 9e reaches close to the center position of the slot 9d, and a ball 42 having a diameter equal to the width of the pocket 9e is provided between the spring 32 and the stopper pin 41. It is located. As a result, each spring 32 presses the balls 42 on both sides so as to be positioned at both ends of the pocket 9e, and constantly urges each stopper pin 41 so as to be at the center position of the elongated hole 9d as shown in FIG. This is set to the unloaded position where the clutch 31 is mechanically disconnected. However, various specific structures for restricting and restoring the relative rotation range of the wheel 8 and the hand rim 9 can be designed.

In this embodiment, the clutch 31 is a one-way clutch, which is engaged and disengaged in response to the relative rotation of the hand rim 9 with the wheel 8, and is semi-connected immediately before the connection is completed between the no-load position and the maximum relative rotation position. I am in a state.

Specifically, as shown in FIGS. 2 and 3, the clutch 31 has a circular outer surface 11b on the drive shaft 11 side formed by an auxiliary member 11a attached to the drive shaft 11 and a hub 8a of the wheel 8.
Between the polygonal inner surface 8c on the side of the wheel 8 formed by the auxiliary member 8b attached to the above, there is play between the polygonal inner surface 8c when corresponding to each corner, that is, the rotation state cannot be transmitted. The rolling member 43 located at is provided.

Each rolling member 43 is attached to, for example, the hand rim 9 and held by a retainer 9b which is a member on the side of the hand rim 9. Therefore, the retainer 9b has the drive shaft 1
As shown in FIG. 2, the state of intrusion between the first side and the wheel 8 side is achieved, and by utilizing such an intruding structure, the displacement transmission extending from the retainer 9b to the inner surface side of the wheel 8 and facing the torque responsive member 33 is transmitted. The rod 9c is integrally provided. On the other hand, the torque responsive member 33 is supported on the outer periphery of the drive shaft 11 so as to be rotatable and slidable in the axial direction, and the displacement transmitting rod 9c is slid in the axial direction in an axial groove 33a provided on the outer surface side of the torque responsive member 33. The displacement of the displacement transmitting rod 9c is made possible by fitting so that the helicoid groove 33b provided on the inner surface side of the torque responsive member 33 is engaged with the guide pin 11c on the drive shaft 11 to rotate the torque responsive member 33. The direction changing means 34 is configured to slide in the axial direction by the guide of the helicoid groove 33b and the guide pin 11c according to the rotation amount.

The torque sensor 36 is the forward torque sensor 3 facing the outer periphery of the flange 33c of the torque responsive member 33.
6a and the reverse torque sensor 36b are combined to generate an eddy current depending on the proximity of the flange 33c. The torque response member 33 is the hand rim 9
According to the manual operation torque when the wheel is manually operated.
A relative rotation occurs between the torque response member 33 and the torque response member 33 in the axial direction according to the relative rotation amount and the relative rotation direction at that time. Therefore, this movement position is detected by the two torque sensors 36a and 36b. And the ratio, the magnitude of the manual operation torque applied to the hand rim 9 and the forward and reverse directions can be easily determined. The controller 23 performs such determination and the drive of the motor 21 based on the determination.

As described above, the drive shaft 11, the wheel 8 and the hand rim 9 are coaxial with each other, and are located on the outer surface side of the wheel 8 by utilizing the shaft supporting portion of the wheel of the conventional manually operated frame. A motor 2 that supports the hand rim 9 so that it can rotate independently and that incorporates a drive shaft 11 that is connected to the wheels 8 via a clutch 31 and that is connected to the drive shaft 11.
1 can also be attached as shown in FIGS. 1 and 2, the frame structure does not particularly complicate due to the presence of the drive mechanism, does not cause an increase in size, and can reduce the cost, as well as the conventional method. It is convenient because the frame of the manual wheelchair can be used as it is and easily modified.

Normally, the wheels 8 are stopped by being grounded and receiving a load, and the motor 21 is stopped by the absence of torque detection output from the torque sensor 36. Each time the hand rim 9 is manually operated in this state, the spring 32 connected to the wheel 8 is connected.
Against the wheel 8, the wheel 8 rotates relative to the wheel 8 within a predetermined range X by an amount corresponding to the operation torque, and after reaching the maximum relative rotation position for transmitting the driving torque to the wheel 8, the wheel 8 directly transmits the rotation. While being able to drive manually. At this time, the manual operation torque applied to the hand rim 9 is detected from the amount of relative rotation of the hand rim 9 with respect to the wheels 8, and when the manual operation torque is in the vicinity of the clutch being in the semi-engaged state or higher, the motor 21 is operated to drive the wheels 8 via the clutch 31 to perform power assist. Each time the manual operation of each time is completed, the hand rim 9 is released from the manual operation and the spring 3 that works between the hand rim 9 and the wheel 8 is released.
The urging force of 2 restores the original state from the relative rotation state with the wheel 8. Therefore, as the detected manual operation torque sharply decreases and disappears, the rotation of the motor 21 also decreases and finally the transmission of the rotation to the wheels 8 via the clutch 31 is stopped. After that, the coasting becomes exactly the same as the manual operation type, and the speed gradually decreases. Therefore, while adopting the same operation form as the manual operation and obtaining the same running state and operation feeling as the manual operation, the power assist corresponding to the operation torque greatly reduces the manual operation force to allow easy operation and travel.

In particular, as the operation torque, the amount of displacement of the hand rim 9 with respect to the wheel 8 is changed by the direction changing means 34.
Is converted into an axial displacement of the drive shaft 11 of the torque responsive member 33 located on the inner surface side of the wheel so that the torque sensor 36 on the fixed portion 35 located on the inner surface side of the wheel 8 faces the torque responsive member 33. Since the manual operation torque can be detected from this displacement amount, the torque sensor 36 can be kept stopped and the output from this can be taken out without the slip ring / brush structure and used for the control, thereby simplifying and downsizing the structure. Is achieved and the cost can be reduced. Moreover, because the output is stable, smooth driving is realized.

Then, regardless of whether the clutch 31 is switched between the properly connected state and the disconnected state electrically or mechanically, the wheel 31 and the drive shaft 11 that rotate coaxially with the clutch 31 are provided. Since they are directly connected and disconnected between them, when used as a manually operated type while keeping the disconnected state, no load is applied to the motor 21 side, so it becomes easy to manually operate with a small running resistance.
This is advantageous when the battery runs out.

Moreover, when the hand rim 9 is manually operated to rotate relative to the wheels 8, the clutch 31 which is a one-way clutch responds to this and the state changes to the connection side.
At the maximum relative rotation position, it becomes a semi-connected state just before the connection is completed,
When the motor 21 is driven according to the manual operation torque detected during the relative rotation, this driving force acts on the clutch 31 in the semi-connected state so as to shift the clutch 31 to the completely connected state, and the firmly connected state is established. However, since the power assist is started, it is possible to smoothly and smoothly shift from the manual operation state to the power assist state and to surely achieve the power assist. Further, when the vehicle is manually operated, the clutch 31 is connected between the drive shaft 11 that is stopped and the wheel 8 that is rotating in the traveling direction if the motor 21 is turned off. Since it is only acted in the direction of escaping from the wheel, it will not be in a completely connected state, and the wheel 21 can be manually operated after the maximum relative rotation position of the hand rim 9 with the wheel 8 side without being affected by the stopped motor 21 side. 8 can be rotated integrally and can run. Therefore, there is an advantage that the power assist type and the manual operation type can be selectively used by a simple and inexpensive structure that does not require special control or mechanism.

Further, the timely connection / disconnection having the one-way clutch function of the clutch 31 responsive to the relative rotation of the hand rim 9 is such that the retainer 9b on the side of the hand rim 9 makes the rolling member 43 of the clutch 31 polygonal with the circular outer surface 11b. By moving the hand rim 9 toward the connection position side where the distance between the inner surface 8c and the inner surface 8c becomes narrower or the cutting position side where the distance becomes wider in accordance with the manual operation direction, both the forward direction side and the reverse direction side are achieved. Therefore, one forward clutch can be used for both forward movement and reverse movement. Also, the hand rim 9
Since the retainer 9b on the side is inserted between the wheel 8 and the drive shaft 11 in which the clutch 31 is provided to hold the rolling member 43, the retainer 9b is utilized by utilizing this insertion.
It is possible to easily achieve the connection between the hand rim 9 side and the torque responsive member 33 via the direction changing means 34 by facing the inner surface of the wheel 8. Although the rolling member 43 is a roller member, it may be a ball member and its shape is not particularly limited.

When the wheels 8 rotate too fast on a slope, when the hand rim 9 is released, the amount of relative rotation between the wheels 8 and the wheels 8 becomes small or disappears. Since the speed is reduced or the state is turned off, even if the rotation of the drive shaft 11 exceeds the rotation of the wheels 8, this is immediately eliminated and the rotation of the wheels 8 is not affected, and the speed of the motor 21 is reduced. Even if the drive shaft 11 is turned off and the rotation of the drive shaft 11 is slowed down, or even if the drive shaft 11 is stopped, the rotation of the wheel 8 is not affected by idling with the wheel 8. When the rotation of the wheels 8 is still fast even when the motor 21 is turned off, when a braking force is manually applied to the hand rim 9, relative rotation in the opposite direction occurs between the wheels 8 and the hand rim 9, and the reverse manual operation torque at this time causes Since the motor 21 is driven in the reverse direction and reaches the wheels 8 via the drive shaft 11 and the clutch 31, so-called engine braking due to the reverse torque of the motor 21 acts on the wheels 8 to easily rotate the wheels 8 to a desired speed. In addition, it can be dropped securely and is highly safe for driving on slopes.

FIG. 6 is a block diagram showing the mechanical characteristics of this embodiment. The controller 23 in this drawing is shown in FIG.
Is shown in block diagram form in FIG. In FIG. 7, the outputs from the torque sensors 36a and 36b are input to the differential amplifier 51 of the controller 23, and the output difference between the two is obtained.
The output from the differential amplifier 51 is sent to the characteristic conversion circuit 52 as shown in FIG.
After performing the characteristic conversion process as shown in
By performing PWM conversion processing by the converter 53, an energization control signal having a duty ratio according to the manual operation torque given to the hand rim 9 is formed, and the drive circuit 54 is operated based on this to generate the energization control signal. It is designed to be driven at a rotational speed according to the operating torque.

However, the energization control signal may be one that controls voltage, or another control method may be adopted.

9 to 11 show a second embodiment of the present invention. In the present embodiment, the direction changing means 34 is a cam that is integrally connected to the torque responsive member 33 via the torque transmission member 63 and the inclined surface 9g that is provided in the inner periphery of the boss 9a of the hand rim 9 and is inclined in the rotational direction. The rolling member 62 is provided between the outer circumference of the member 61 and the cam surface 61a inclined in the axial direction.
Is provided, and the rolling member 62 is held by a retainer 8k on the wheel 8 side, which is formed by a part that forms a clutch housing portion 8h with the drive shaft 11 of the wheel 8. Further, instead of the one clutch of the first embodiment, the forward direction in which the forward rotation of the drive shaft 11 is transmitted to the wheels 8 in response to the movement of the cam rim 61 in the axial direction corresponding to the forward rotation direction of the hand rim 9. A transmission one-way clutch 71 and a reverse transmission one-way clutch 72 that transmits the reverse rotation of the drive shaft 11 to the wheels 8 in response to the movement of the cam member 61 in the axial direction corresponding to the reverse rotation direction of the hand rim 9. There is as a thing.

The forward transmission and reverse transmission one-way clutches 71 and 72 are conical roller bearings, respectively, and are arranged so that the rollers 73 are skewed. The forward transmission one-way clutch 71 is fixed to the inner ring 71a. Against the outer ring 71b
Can slide in a predetermined range in the axial direction, and the outer ring 71b is
When 3 is touched, it is in a connected state, and when it is separated from the roller 73, it is in a disconnected state. When the drive shaft 11 side rotates in the forward direction in the connected state, the skewed rollers 73 cause the inner and outer rings 71 to move.
Twisting occurs between a and 71b to integrate them, and the forward rotation of the drive shaft 11 is transmitted to the wheels 8. The reverse transmission one-way clutch 72 has a fixed inner ring 72a and an outer ring 7a.
2b can slide in the axial direction within a predetermined range, and when the outer ring 72b contacts the roller 73, the connected state is established, and when the outer ring 72b leaves the roller 73, the disconnected state is established. Then, when the drive shaft 11 side rotates in the opposite direction in the connected state, the skewed roller 73 twists between the inner and outer rings 72a, 72b to integrate them,
The reverse rotation of the drive shaft 11 is transmitted to the wheels 8.

Although these one-way clutches 71 and 72 are somewhat special, they are commercially available and mass-produced.
It is cheaper than using a new special clutch like the first embodiment.

These one-way clutches 71, 72 for forward transmission and reverse transmission are positioned between them so that they can be connected / disconnected in a timely manner in response to the movement of the cam member 61 in the axial direction. The springs 74 and 75 for urging the cam member 61 are actuated between the clutch housing portion 8h and the normal direction where the hand rim 9 is not manually operated. , 72, a spring 76 is exerted between the one-way clutch 71 and the cam member 61 so that both can be returned to the disengaged state.

Since the other structure is almost the same as that of the first embodiment, its illustration and description are omitted.

In this embodiment, since the two one-way clutches 71 and 72 for forward transmission and reverse transmission are used, as described above, a special clutch that exerts a one-way clutch function in both forward and reverse directions is unnecessary. However, since the two clutches 71 and 72 are mounted between the wheel 8 and the drive shaft 11 together with the direction changing means 34, the entire size does not particularly increase, and the size and cost are reduced. be able to. Further, the safety when traveling on a slope can be exhibited as in the case of the first embodiment.

A flesh steal portion 72c is formed on the outer ring 72b of the one-way clutch 72 to adjust the wall thickness of the portion in contact with the roller 73, and when an unreasonable load is generated in the connected state, this portion is elastically deformed. Further safety is ensured by preventing slippage in the connection state and transmission of unreasonable rotation.

12 and 13 show a third embodiment of the present invention. In the present embodiment, an electromagnet 81 is provided on the fixed side so as to face the torque responsive member, and the torque responsive member 33 is forwardly transmitted by appropriately energizing or de-energizing the one-way clutch 71 from the disconnected state to the connected state. I am trying to move it to. This is convenient when moving forward in a forward rotation, which is frequently used and has a long mileage. Therefore, the present invention is not limited to this, and may be applied to the reverse transmission one-way clutch 72 or both.

In this embodiment, the forward transmission one-way clutch 71 moves in the axial direction together with the cam member 61 of the direction changing means 34 to perform the connecting / disconnecting operation.
Since the torque responsive member 33 that moves in unison with the electric magnet 81 is moved and moved back and forth in the axial direction by an electric control, the torque responsive member 33 can be independently connected and disconnected at appropriate times. Left and right wheels 8
When one of the wheels 8 is to be driven in advance, the drive signal is given to the controller 23 for the other wheel 8 by the left-right synchronization circuit 82 using the operation signal of the one controller 23 as shown in FIG. The other wheel 8 is forcibly driven. As a result, power assistance to the left and right wheels can be simultaneously started without variation, and meandering during forward traveling can be prevented.

Since the other structure and operation are the same as those of the second embodiment, the duplicated description will be omitted.

14 to 16 show a fourth embodiment of the present invention. In the present embodiment, between the cam member 61 and the one-way clutches 71 and 72 for forward transmission and reverse transmission,
A rotation transmission control provided so as to be movable between the position shown in FIG. 16 for moving and holding each of the one-way clutches 71, 72 to the rotation transmission position and the position shown in FIGS. 14 and 15 for releasing the holding. The member 91 and this rotation transmission control member 9
And an operating member 92 for operating 1 from the outside.

The rotation transmission control member 91 shares the cam member 61 and the outer ring 72b of the one-way clutch 72, and a pocket provided on one surface of the cam member 61 and the outer ring 72b facing each other. A ball 91b rotatably held in 91a and an engaging recess 91c provided on the other surface for engaging and disengaging with the ball 91b are provided. The ball 91b and the engaging recess 91c rotate the cam member 61. Both are engaged or disengaged with each other, and the one-way clutches 71 and 72 are disengaged when they are disengaged.
The one-way clutch 7 is engaged when engaged as shown in the disengaged state.
1, 72 are designed to be maintained in the connected state shown in FIG.

Then, the cam member 61 is provided with passive pins 91d as the rotation transmission control member 91 at several positions in the circumferential direction, and the passive pins 91d are provided in the outer ring 72b of the one-way clutch 72 and the arc-shaped long holes 72d and the clutch housing. Arc-shaped elongated hole 8 of the portion 8h
The dial-type operation member 92 is connected to the protruding end of each passive pin 91d through m and the cam member 61 is rotationally operated from the outside by operating the operation member 92. 16 and FIG.
It can be switched to the connected state of.

However, the specific structure for such switching is not limited to that of the present embodiment, but various designs can be made.

In the connection state of FIG. 16, the one-way clutch 71, regardless of whether the hand rim 9 and the wheel 8 rotate relative to each other,
Since 72 is maintained in the connected state, it can be conveniently used as a fully self-propelled electric wheelchair by controlling the left and right motors ON / OFF and the rotation speed with a joystick or the like.

Further, in this embodiment, the operating member 92 is rotatably supported on the outer surface of the tubular portion 8n protruding from the outer end plate portion of the clutch housing portion 8h, and the operating position shown in FIGS. The operation position in FIG. 16 is fixed by the plunger 101 in accordance with the determination of the use state of the electric wheelchair so that careless switching does not occur. As a matter of course, other methods may also be adopted.

[0066]

According to the first feature of the electric wheelchair of the present invention, the drive shaft, the wheel, and the hand rim are coaxial with each other, and the frame structure does not particularly complicate due to the existence of the drive mechanism and is large in size. It is not a cause of the above, and the cost can be reduced, and it is convenient that the frame of the conventional manual wheelchair can be used as it is and easily modified.

Since the motor is operated according to the manual operation torque given to the hand rim to drive the wheels through the clutch to perform the power assist, the same operation form as the manual operation is adopted, and the same running state and operation feeling as the manual operation are adopted. The manual operation force is greatly reduced by the power assist according to the operation torque so that the vehicle can be operated and traveled easily.Especially, the torque sensor on the fixed part can detect the manual operation torque, and the torque sensor stops. As it is, the output from now on can be taken out without the slip ring / brush structure and used for the control, so that the structure can be simplified and downsized, and the cost can be reduced. Moreover, because the output is stable, smooth driving is realized.

Regardless of whether the clutch is switched between the timely connected state and the timely disconnected state electrically or mechanically, when the clutch is kept in the disconnected state and used as a manually operated type, the clutch is Since it is located in the immediate vicinity of the wheels, no load is applied on the motor side, which facilitates manual operation with low running resistance, which is advantageous when the battery runs out.

According to the second, third and fourth features of the present invention, it is possible to smoothly and smoothly shift from the manual operation state to the power assist state and to surely achieve the power assist. it can. Also, when performing a manual operation type drive, simply turn off the power to the motor and run the wheel by driving the wheel integrally with the hand rim after the maximum relative rotation position with the wheel side to perform special control. The structure that does not require a mechanism or mechanism is simple and inexpensive, and has the advantage that it can be used separately for the power assist type and the manual operation type.

According to the third feature of the present invention, one forward clutch can be used for both forward movement and reverse movement. Further, by utilizing the fact that the retainer on the hand rim side is inserted between the wheel and the drive shaft provided with the one-way clutch for holding the rolling member, the direction changing means between the hand rim side and the torque responsive member is used. The connected connection can be easily achieved.

According to a fourth aspect of the present invention, two one-way clutches for forward transmission and reverse transmission are used,
A special clutch that exerts a one-way clutch function in both forward and reverse directions is not necessary, and since the two clutches are mounted between the wheel and the drive shaft together with the direction changing means, the size of the whole becomes particularly large. Instead, it can be small and inexpensive.

According to the third and fourth characteristics of the present invention, when the wheels rotate too fast on a slope, when the hands are released from the hand rim, the rotation of the motor becomes slower or the motor is turned off. The rotation of the wheels will not affect the rotation of the wheels, and even if the rotation of the drive shaft slows or stops, the wheels will idle and will not affect the rotation of the wheels. If the rotation of the wheel is still fast, the motor is driven in the opposite direction by manually applying the braking force to the hand rim and acts as a so-called engine brake on the wheel, so it is possible to easily and reliably reduce the rotation of the wheel to the desired speed. It is also highly safe for driving on slopes.

According to the fifth feature of the present invention, at least the forward transmission one-way clutch is independently opened / closed at a proper time by electrical control using an electromagnet to start traveling by relative rotation of the hand rim. It is possible to simultaneously start the power assist to the left and right wheels by simultaneously driving one of the left and right wheels ahead of the other, and forcibly driving the other. It is possible to prevent meandering in the forward traveling that is a rotation.

According to the sixth feature of the present invention, the one-way clutches for forward transmission and reverse transmission are externally moved to the rotation transmission position as needed and held, so that the drive shaft is rotated. It is convenient because it can be used as a completely self-propelled electric wheelchair by controlling the on / off of the left and right motors and the rotation speed with a joystick or the like in a state of being constantly transmitted to wheels.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing a drive shaft, wheels, and a coaxial rotating portion of a hand rim of the electric wheelchair shown in FIG.

3 is a side view showing a part of the one-way clutch and the direction changing means of FIG. 1. FIG.

FIG. 4 is a cross-sectional view showing the hand rim and the wheel spring coupling structure of FIG. 1 and a one-way clutch in an unloaded state.

FIG. 5 is a partial cross-sectional view showing the state of FIG. 4 in a forward rotation operation and a reverse rotation operation.

6 is a driving force of the electric wheelchair shown in FIG. 1, a hand rim displacement,
FIG. 3 is a block diagram showing a transmission path of an electric signal.

7 is a block diagram showing a controller of the electric wheelchair shown in FIG. 1. FIG.

8 is a graph showing an input / output characteristic example of a characteristic conversion circuit in the controller of FIG.

FIG. 9 is a cross-sectional view showing a drive shaft, a wheel, and a coaxial rotating portion of a hand rim of an electric wheelchair according to a second embodiment of the present invention in a forward transmission state.

FIG. 10 is a cross-sectional view of FIG. 9 in a reverse transmission state.

11 is a cross-sectional view showing a part of the direction changing means of FIG. 9. FIG.

FIG. 12 is a sectional view showing a drive shaft, wheels, and a coaxial rotating portion of a hand rim of an electric wheelchair as a third embodiment of the present invention.

13 is a block diagram of a control system of the electric wheelchair shown in FIG.

FIG. 14 is a sectional view in a normal state showing a drive shaft, wheels, and a coaxial rotating portion of a hand rim of an electric wheelchair as a fourth embodiment of the present invention.

FIG. 15 is a cross-sectional view of FIG. 14 seen from different angles.

16 is a cross-sectional view of the electric thing of FIG. 14;

[Explanation of symbols]

 1 frame 6 bearing member 8 wheel 8a hub 8c polygonal inner surface 8k retainer 9 hand rim 9a boss 9b retainer 9d long hole 9g inclined surface 11 drive shaft 11b circular outer surface 21 motor 23 controller 31 clutch 32 spring 33 torque responsive member 35 direction conversion member 34 Fixed part 36 Torque sensor 41 Stopper pin 43 Rolling member 61 Cam member 61a Cam surface 62 Rolling member 71 Forward transmission one-way clutch 72 Reverse transmission one-way clutch 73 Roller 74, 75, 76 Spring 81 Electromagnet 82 Left-right synchronization circuit 91 Rotation Transmission control member 92 Operation member

Claims (6)

[Claims] 1. The left and right wheels are connected to a hand rim by springs, a manual operation torque applied to the hand rim is detected from a relative movement amount of the hand rim with respect to the wheels, and a motor is operated according to the manual operation torque to operate a clutch. An electric wheelchair that drives wheels via a wheel to perform power assist, in which the drive shaft on the motor side is arranged so as to rotate coaxially with the wheel and the hand rim, and the wheel and clutch are connected via a clutch to displace the hand rim in the rotational direction with respect to the wheel. Of the torque responsive member located on the inner surface side of the wheel in the direction of the axial line, and the torque responsive member in response to the axial displacement of the torque responsive member. An electric wheelchair comprising a torque sensor for detecting 2. A one-way clutch in which the clutch is engaged and disengaged in response to relative rotation of the hand rim with respect to the wheel, and is in a semi-engaged state immediately before connection completion between the no-load position and the maximum relative rotational position. The electric wheelchair according to claim 1. 3. A one-way clutch is a rolling member that is positioned between a circular outer surface on the side of a drive shaft and a polygonal inner surface on the side of a wheel, with play therebetween when corresponding to each corner of the polygonal inner surface. The electric wheelchair according to claim 2, wherein each rolling member is held by a retainer on the hand rim side. 4. The direction changing means has an inclined surface inclined in the rotational direction, which is partially provided on the inner periphery of the hand rim, and an axially inclined cam surface of the outer periphery of the cam member integrally connected to the torque responsive member. A rolling member is provided between the wheels, and this rolling member is held by a retainer on the wheel side.The clutch responds to the movement of the cam member in the axial direction corresponding to the normal rotation direction of the hand rim, and the forward rotation of the drive shaft is rotated by the wheel. And a reverse transmission one-way clutch for transmitting the reverse rotation of the drive shaft to the wheels in response to the movement of the cam member in the axial direction corresponding to the reverse rotation direction of the hand rim. The electric wheelchair according to claim 1. 5. An electromagnet which is provided on the fixed side so as to face the torque responsive member, and which is appropriately energized to attract and move the torque responsive member at least from the disengaged state of the forward transmission one-way clutch to the engaged state. Claim 4 provided with
Electric wheelchair described in. 6. A position between a cam member and each one-way clutch for forward transmission and each reverse transmission, which is moved to a rotation transmission position to hold the one-way clutch, and a position where the holding is released. The electric wheelchair according to claim 4, further comprising: a rotation transmission control member provided so as to be movable between them; and an operation member for operating the rotation transmission control member from the outside.