JPH10127700A - Wheelchair with auxiliary power - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly travel in spite of recess/projection on the surface of the ground by arranging a power auxiliary device formed by uniting a motor, a decelerating mechanism and a driving wheel in the center of a right/left direction in a space under a wheelchair. SOLUTION: This wheelchair 1 is provided with a frame consisting of a pipe-like member and frame is provided with side frames 3 connected with an X-shaped connecting hardware. A stay holder 18 consisting of a plate material is fixed to the lower/rear part of this right/left side frames 3 to be freely attached and detached and a stay pipe 23 is engage-fixed to a boss part 22 projectingly formed at the stay holder 18. Then the power auxiliary device A formed by uniting the motor, the decelerating mechanism and the driving wheel by using this stay pipe 23 is arranged so that the device A is at the center of a right and left direction in the space part under the wheel chair 1 in the state of keeping driving wheels in contact with the surface of the ground. Otherwise the motor of the device A is connected with a centrifugal clutch intermitting power transmission based on the output of a detection means detecting the revolution of the motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheelchair with a power assisting function, which can provide a driving force based on a driving intention of a user or a caregiver using a wheelchair.

[0002]

2. Description of the Related Art Conventionally, a wheelchair is driven by providing an auxiliary driving force, for example, as disclosed in Japanese Unexamined Patent Publication No. Hei.
There are those described in JP-A-15468 and JP-A-6-86790. First, in Japanese Patent Application Laid-Open No. HEI 3-15468, a hand rim is connected to a pair of driving wheels of a wheelchair via torque detecting means, and is input from a hand rim operated by a user of the wheelchair. The operation torque is detected by torque detecting means, and the operation of the electric motor for driving the drive wheels is controlled based on the detected value. Specifically, when the hand rim is operated with the drive wheels stopped, the torsion bar is twisted and a relative rotation angle occurs between the input shaft and the output shaft, and the torsion of the torsion bar is detected by a strain gauge. This is detected as an operating torque via a torque sensor. In addition, Japanese Patent Application Laid-Open No. 6-86
No. 790 discloses a general wheelchair in which a motor mounting pedestal is fixed and a driving motor is mounted, and a small-diameter small wheel attached to a tip of a driving shaft of the driving motor is used as a driving wheel for a wheelchair. Contact the outer peripheral surface freely
The drive motor is driven by operating the control lever of the operation panel box, and the drive wheel of the wheelchair is driven by small wheels,
When the vehicle is not driven, the small wheels are separated from the driving wheels.

[0003] Furthermore, there has been disclosed an apparatus in which a wheel having a drive mechanism built therein is formed as a unit, and auxiliary power can be given by replacing the dedicated wheel with a wheelchair wheel. Also in this case, when the user operates the hand rim, the operation force is detected and the drive mechanism operates.

[0004]

Problems to be Solved by the Invention
The structure described in Japanese Patent Application Laid-Open No. H11-20764 detects the torque applied to the hand rim operated by the user using the wheelchair and controls the operation of the electric motor.
It is useful when the wheelchair user is using it alone, but when the caregiver is pushing the wheelchair, it is not possible to detect the operating force of the caregiver, so obtain auxiliary power Can not. Also, structurally, since the operating force detection mechanism is provided for each of the left and right drive wheels,
There is also the problem of structural complexity. Further, there is a problem that the wheelchair cannot be folded due to structural restrictions, and a space is required for transportation and storage.

The one described in Japanese Patent Application Laid-Open No. 6-86790 can be mounted on a general wheelchair to be electrically operated, and can be selectively used for both manual operation and electric operation by attaching and detaching the device. Having. However, the operation is to adjust the traveling speed or change the direction by operating the control lever, and the operation is difficult. Therefore, practice is required to learn the operation. In addition, there is a problem that it is difficult to perform a switching operation of canceling the power assist and enabling the power assist at a place where the power assist is required when traveling on a flat ground that does not require the power assist.

Further, in the case of using a dedicated wheel having a built-in drive mechanism, a general wheelchair is wasted and the dedicated wheel must be used separately. The wheelchair is a special-purpose wheelchair, and the wheels must be reattached in order to return to the wheelchair for manual traveling.
In addition, while the wheelchair user performs a necessary function when using the wheelchair, the auxiliary power cannot be used when the caregiver presses the wheelchair.

According to the present invention, by arranging the power assist device in the center of the lower space of the wheelchair in the left-right direction, both the user and the caregiver of the wheelchair can effectively use the auxiliary power according to the operation state of the wheelchair. It is an object of the present invention to provide a wheelchair with a power assist device that can be folded in a state where the power assist device is provided and that can run even if there is some unevenness on the ground surface.

[0008]

According to the first aspect of the present invention,
A power assisting device formed by unitizing an electric motor, a speed reduction mechanism, and a driving wheel, wherein the power assisting device is disposed at the center in the left-right direction of a lower space portion of a wheelchair with the driving wheel in contact with the ground surface. It is. Therefore, the power assist device can be attached using the lower space of the wheelchair, and it is easy to add the power assist device to a general wheelchair. Since it is located at the center, its structure is simple.

According to a second aspect of the present invention, the width of the power auxiliary machine can be reduced. Therefore, since it can be folded during transportation or storage, the required space may be small.

According to a third aspect of the present invention, an electric motor of the power assisting device is provided with a detecting means for detecting the rotation of the electric motor, and a centrifugal clutch for interrupting the transmission of power based on the output of the detecting means is connected. is there. Therefore, when providing auxiliary power to the main drive wheel of a wheelchair, it is only necessary to provide a drive signal to the electric motor, and when no auxiliary power is required, the connection with the mechanism on the electric motor side can be cut off. The presence of the auxiliary machine does not hinder the manual operation.

According to a fourth aspect of the present invention, a power assisting device is attached to a wheelchair so as to be rotatable in the front-rear direction, and a driving wheel of the power assisting device is biased in a direction in which the driving wheel comes into contact with the ground. Therefore, the drive wheels in contact with the ground surface are less slippery,
The driving force can be surely exerted, and even if there are some irregularities on the ground surface, the driving wheels can be surely grounded and driven.

According to a fifth aspect of the present invention, an acceleration sensor is attached to a wheelchair, and the driving of the electric motor is controlled by an output signal of the acceleration sensor. Therefore, not only the user of the wheelchair but also the caregiver can automatically apply the auxiliary power even if the wheelchair is pushed, and even when it is necessary to stop suddenly for some reason, the negative acceleration of the acceleration sensor is detected. This allows the auxiliary power to be shut off immediately.

According to a sixth aspect of the present invention, a tilt sensor is mounted on a wheelchair, and the driving of the motor is controlled by an output signal of the tilt sensor. Therefore,
Control to automatically apply auxiliary power when approaching an uphill slope, or to increase the auxiliary power when approaching an uphill slope when auxiliary power is applied on flat ground It can be performed.

[0014]

An embodiment of the present invention will be described with reference to the drawings. First, the wheelchair 1 is a general one manufactured based on the JIS standard, and the wheelchair 1 is assembled on the basis of a frame 2 made of a pipe-shaped member. The frame 2 is composed of side frames 3 which are connected to each other by X-shaped connecting metal fittings (not shown) so as to be located on both sides so as to be able to widen or shrink each other. These side frames 3 are a vertical front frame 4 located in the front, a vertical rear frame 5 located in the rear, and a horizontal lower frame 6 which is positioned vertically and connects the front frame 4 and the rear frame 5. And an upper frame 7. A front wheel 8 having a small diameter is attached to a lower end of the front frame 4, and a handle portion 9 extending upward and then projecting rearward is provided at an upper end of the rear frame 5. Is provided with an armrest 10. A middle frame 12 having a horizontal portion 11 is fixed to an intermediate portion of the side frame 3, and the front ends of the middle frames 12 project downward from the front frame 4 and extend vertically from the horizontal state. A footrest 13 that rotates between the states is formed. Further, a seat 14 formed of cloth or the like is suspended from the horizontal portion 11 of the middle frame 12. A backrest sheet 15 made of cloth or the like is also suspended from the rear frame 5. A main drive wheel 16 having a large diameter is rotatably mounted behind the side frame 3. A wheel-shaped hand rim 17 having an outer diameter slightly smaller than the outer diameter of the main drive wheel 16 is fixed to the outside of the main drive wheel 16.

Next, there is provided a power assisting device A detachably attached to the wheelchair 1. First, a stay holder 18 made of a plate material is detachably attached to a lower rear portion of the left and right side frames 3. These stay holders 18 are integrally bent and formed rearwardly at the lower edge thereof, and are formed into a semicircular holding portion 19 which is fitted into the lower frame 6 from the inside to the outside. And a holding portion 20 that is fitted into the rear frame 5 from inside to outside. And the holding part 20 is
It is fixed by a fixing bolt 21 screwed in from the inside,
Thereby, the stay holder 18 is detachably attached to the side frame 3. That is, the stay holder 18 is fixedly attached to a rear portion where the rear frame 5 and the lower frame 6 intersect.

The stay holder 18 thus formed is formed with a cylindrical boss 22 projecting therefrom.
2, a stay pipe 23 is fitted and fixed.
The stay pipe 23 includes a large-diameter large-diameter stay 24 slidably fitted to each other and a small-diameter small-diameter stay 25 fitted to the large-diameter stay 24, and pin holes 26 respectively formed at intermediate portions. , 27 are fixed to the longest state by fitting the center pin 28 therein. A boss 29 is fitted into the large-diameter stay 24 of the stay pipe 23, and the boss 29 is also fitted to the center pin 28.
Is fixed to the stay pipe 23.

At both ends of the boss 29, bearings 30 are provided.
The frame stay 31 is rotatably mounted via the. These frame stays 31 are opposed to each other, and a bearing holder 32 is attached to a lower end thereof. A driving wheel 34 is rotatably held by bearings 33 held by these bearing holders 32. ing.

An electric motor 35 is fixed to the stay holder 18, and the electric motor 35 and the driving wheels 34 are connected by a power transmission mechanism 36. That is, the drive shaft 37 of the motor 35 is
A centrifugal clutch 38, which is provided with a detecting means for detecting the rotation of the motor and which interrupts the power transmission based on the output of the detecting means, is connected. The centrifugal clutch 38 has a pair of clutch weights 40 acting as detecting means urged toward the center by a pair of tension springs 39. These clutch weights 40 are attached to a drive side wheel body 43 having a guide notch 42 into which an outwardly protruding engaging projection 41 formed on the clutch weight 40 is slidably inserted. A driven side wheel body 45 having a large number of crown-shaped teeth 44 with which the engagement protrusion 41 of the clutch weight 40 is disengaged is provided outside the drive side wheel body 43. Therefore, the centrifugal clutch 38 includes a drive-side wheel body 43 that holds a pair of clutch weights 40 and a driven-side wheel body 45 into which the drive-side wheel body 43 is rotatably fitted.

However, one of the frame stays 31
A sub-frame 46 is fixed to the inner surface of the frame, and a speed reduction mechanism B is provided between the sub-frame 46 and the frame stay 31. That is, the bearing 4 is provided between the sub-frame 46 and the frame stay 31.
The first intermediate gear 50, the second intermediate gear 51, and the third intermediate gear 52 rotatably supported by 7, 48, and 49, respectively.
Is provided. The first intermediate gear 50 has a large-diameter driven gear 53 and a small-diameter drive gear 54 formed concentrically and integrally, and the second intermediate gear 51 has a large-diameter driven gear 55 And a small-diameter drive gear portion 56 are formed concentrically and integrally, and the third intermediate gear 52 is
The large-diameter driven gear portion 57 and the small-diameter drive-side gear portion 58 are integrally formed concentrically. The driven wheel 45 of the centrifugal clutch 38 is held by a bearing 45a, and a small-diameter drive gear 59 is formed on the back surface of the driven wheel 45. This drive gear 59
Is meshed with a large-diameter driven gear portion 53 of the first intermediate gear 50. The small-diameter drive gear portion 54 of the first intermediate gear 50 is connected to the large-diameter driven gear portion 5 of the second intermediate gear 51.
5 is engaged. The small-diameter drive gear portion 56 of the second intermediate gear 51 is meshed with the large-diameter driven gear portion 57 of the third intermediate gear 52. Further, the driving wheel 3
On one side of 4, a passive gear portion 60 is formed, and a small-diameter drive-side gear portion 58 of the third intermediate gear 52 is meshed with the passive gear portion 60.

A U-shaped holder 62 is fixed to the prism 61 of the boss 29. The holder 62 is formed by press-molding a sheet metal material.
On one side thereof, a spring hook portion 63 also serving as a stopper portion is integrally formed. A spring hook 64 is bent below the frame stay 31. A spring 66 wound in a coil shape is attached to the cylindrical portion 65 of the boss 29. One leg 67 of the spring 66 is locked by the spring hook 63, and the other leg 68 is It is locked to the spring hook 64. Therefore, the frame stay 31 is biased in a direction in which the drive wheel 34 moves forward. That is, the center of rotation of the frame stay 31 is the stay pipe 23, and the drive wheel 34 is positioned at a position displaced backward from the position of the stay pipe 23, and the drive wheel 34 The frame stay 31 is urged by the spring 66 in the direction of increasing the pressing force. An upper plate 70 is fixed to the upper edge of the frame stay 31 so as to connect the frame stays 31 on both sides. In addition, the frame stay 31 is positioned so as to stop moving forward by contacting a part of the frame 2 of the wheelchair 1.

Further, an acceleration / inclination sensor 71 is mounted on the stay holder 18, and a rotation speed detection sensor 72 formed by a magnetic Hall element or the like is mounted on the frame stay 31. The acceleration / inclination sensor 71 is for detecting acceleration and inclination of the wheelchair 1 and serves as reference data for performing various controls described later. The purpose is to detect the number of teeth of the first intermediate gear 50 of the speed reduction mechanism B and obtain a signal for controlling the rotation speed of the electric motor 35. Although not shown,
A battery serving as a power source for driving the electric motor 35 is mounted in a space below the wheelchair 1. A control circuit connected to the acceleration / inclination sensor 71 and the rotation speed detection sensor 72 is provided, and the operation of the electric motor 35 is controlled via the control circuit.

In such a configuration, the method of use is the same as in the case of using a general wheelchair 1. First, a power assist device A formed as a unit is attached to a general wheelchair 1 and used. The attachment is performed by fitting the stay holder 18 to the side frame 3 and fixing it with the fixing bolt 21. During storage, as shown in FIG. 2, it is folded and reduced in the width direction. However, in use, it is expanded in the width direction as shown in FIG.
At this time, since the large-diameter stay 24 and the small-diameter stay 25 slide and extend on the stay pipe 23 of the power assisting device A, the stay holder 18 attached to the side frames 3 even if the distance between the side frames 3 is increased. Follows the extension of the stay pipe 23 and expands the interval between them. By increasing the width in this way, the seat 14 and the backrest 15 are in a tensioned state in which they are horizontally extended, and the stay holder 18
By inserting the center pin 28 into the pin holes 26 and 27, the positions of the large-diameter stay 24 and the small-diameter stay 25 of the stay holder 18 are fixed and fixed to the longest state. Conversely, when folding the wheelchair 1, the center pin 28 can be pulled out from the stay holder 18, so that the operation can be performed with the power auxiliary machine A attached. It is desirable that the center pin 28 that is not required at the time of folding is connected to the frame stay 31 using a chain or the like in order to prevent the center pin 28 from being lost.

As described above, when set to a usable state, a normal use state, that is, a patient or a person who cannot walk, that is, a user, sits on the seat 14 and operates the hand rim 17 to drive the main drive. It is used by turning the wheel 16 or by the caregiver grasping and pushing the handle portion 9. In any case, when the wheelchair 1 starts moving from a stationary state, the acceleration / tilt sensor 71 detects the movement. At the time of this start, the centrifugal clutch 38 is in the disengaged state, which is the same as the state without the power auxiliary machine A, the power transmission mechanism 36 is in an unrelated state, and there is no resistance during operation. Then, when a signal from the acceleration / tilt sensor 71 is given to the control circuit, the electric motor 35 starts rotating. By the rotation of the electric motor 35, the drive-side wheel body 43 fixed to the drive shaft 37 starts rotating at the same speed. Since the clutch weights 40 rotate at the same speed as the drive-side wheel body 43, centrifugal force is generated in the clutch weights 40, and when the rotation speed reaches a predetermined value, the clutch weights 40 resist the tensile force of the tension spring 39. The weights 40 move outward away from each other. That is, the engagement protrusion 41 of the clutch weight 40 is guided by the guide notch 42 of the drive-side wheel body 43, and the clutch weight 40 moves in a direction in which the clutch weights 40 separate from each other. As this movement progresses, the engagement protrusion 41 of the clutch weight 40 engages with the teeth 44 of the driven wheel 45. As a result, the driven side wheel body 45 that has been stationary is mechanically coupled to the drive side wheel body 43 via the clutch weight 40, and thereby both rotate integrally. When the driven side wheel body 45 rotates, the drive wheel 34 is driven via the speed reduction mechanism B. That is, when the driven side wheel body 45 rotates, power is transmitted in the order of the first intermediate gear 50, the second intermediate gear 51, and the third intermediate gear 52, and the rotation speed is sequentially reduced. Since the small-diameter drive-side gear portion 58 of the third intermediate gear 52 meshes with the passive gear portion 60 integrated with the drive wheel 34, the drive wheel 34 receives the driving force of the electric motor 35 and rotates. When the rotation of the electric motor 35 stops, the traveling of the wheelchair 1 is decelerated, and the centrifugal clutch 3
8 runs out. That is, since the centrifugal force acting on the clutch weight 40 is weakened, the clutch weight 40 moves toward the center by the force of the tension spring 39, and the engagement protrusion 4
1 comes off the teeth 44 of the driven side wheel body 45. Therefore, no driving force acts on the driven side wheel body 45, and the wheelchair 1 is in a free state.

The driving wheel 34 is thus driven to rotate, and the power assisting device A uses the spring 6 so that the driving wheel 34 contacts the ground 69 with the stay pipe 23 as the center.
6 (shown as β direction in FIG. 4)
The drive wheel 34 drives the wheelchair 1 with an appropriate ground pressure. This driving is performed at the center of the wheelchair 1 in the left-right direction, so that the straightness is good and the wheelchair 1 shows a good driving state even when turning in the left-right direction using a steering device (not shown). In particular, when the ground surface 69 has irregularities, the power auxiliary machine A rotates (in the α direction in FIG. 4), and the drive wheel 34 temporarily rises and rides on the protrusion. Then, when the power of the power assisting machine A is returned to the original position by the force of the spring 66, when the power of the power assisting machine A is exceeded.

The number of revolutions of the motor 35, that is, the number of revolutions of the drive wheels 34 is set to a predetermined value based on a detection signal from the number-of-rotations sensor 72. That is, the rotation speed detection sensor 72 detects the teeth of the large-diameter driven gear portion 53 of the first intermediate gear 50 of the power transmission mechanism 36, and is driven by counting the number of teeth within a predetermined time. The rotation speed of the wheel 34 is detected. Thereby, it is possible to set the rotation speed of the drive wheel 34 to a predetermined constant rotation speed. The traveling speed controlled in this way is set to be 6 km / h or less in order to ensure safety.

Further, the acceleration / inclination sensor 71 also detects the inclination of the wheelchair 1. If the inclination is an uphill, the output of the electric motor 35 is increased. That is,
Control is performed so that the rotation speed of the drive wheel 34 is constant. If the vehicle is on a downhill, the electric motor 35 is stopped to shut off power transmission. This power cutoff is also performed when the wheelchair 1 is braked for some reason even while traveling on flat ground. That is, when the wheelchair 1 is braked, a negative acceleration is detected as the acceleration by the acceleration / inclination sensor 71, and when the detection signal is the negative acceleration, the power supply to the electric motor 35 is cut off and stopped.

In the embodiment, a circuit for manually controlling the operation of the motor 35 and manually controlling the power by the motor 35 is connected in parallel with the control circuit having the above-described operation. It may be.

[0028]

According to the first aspect of the present invention, there is provided a power assisting device formed by unitizing an electric motor, a speed reduction mechanism, and driving wheels, and the power assisting device is wheelchaired with the driving wheels in contact with the ground. The power assist device can be installed using the lower space of the wheelchair, and it is easy to add the power assist device to a general wheelchair. Is located at the center in the left-right direction of the lower space portion of the wheelchair, so that the structure is simple.

According to the second aspect of the present invention, the width of the power auxiliary machine can be reduced, so that the power auxiliary machine can be folded during transportation or storage, so that the required space can be reduced. Have.

According to the third aspect of the present invention, since the motor of the power assist device is provided with a detecting means for detecting the rotation of the electric motor and a centrifugal clutch for interrupting the transmission of power based on the output of the detecting means is connected. When applying auxiliary power to the main drive wheel of a wheelchair, it is only necessary to give a drive signal to the electric motor,
In addition, when the auxiliary power is not required, the connection with the mechanism on the electric motor side can be cut off, and there is an effect that even if the power auxiliary machine is present, it does not hinder the manual operation.

According to the fourth aspect of the present invention, the power assisting device is attached to the wheelchair so as to be rotatable in the front-rear direction, and the driving wheels of the power assisting device are biased in the direction of contacting the ground.
The drive wheels in contact with the ground surface are less slippery, and the driving force can be surely exerted. Even if there are some irregularities on the ground surface, the drive wheels can be reliably grounded and driven.

According to the fifth aspect of the present invention, the acceleration sensor is attached to the wheelchair, and the driving of the electric motor is controlled by the output signal of the acceleration sensor. Therefore, not only the user of the wheelchair but also the caregiver pushes the wheelchair. Can automatically apply auxiliary power, and even if it is necessary to stop suddenly for some reason, the auxiliary power can be cut off immediately by detecting the negative acceleration of the acceleration sensor. Has an effect.

According to the sixth aspect of the present invention, the inclination sensor is mounted on the wheelchair, and the driving of the electric motor is controlled by the output signal of the inclination sensor, so that the auxiliary power automatically acts when the vehicle approaches an uphill. To do
When the auxiliary power is applied on a flat ground, there is an effect that control such as further increasing the auxiliary power when approaching an uphill can be performed.

[Brief description of the drawings]

FIG. 1 is a perspective view in a use state showing an embodiment of the present invention.

FIG. 2 is a perspective view of a state in which it is folded for storage.

FIG. 3 is a side view of a power assist device mounted on a wheelchair.

FIG. 4 is a side view showing a state where one of the frame stays is removed from a power assist device attached to a wheelchair.

FIG. 5 is a vertical sectional rear view of a speed reduction mechanism of the power assist device.

FIG. 6 is a longitudinal sectional side view of a power assist device attached to a wheelchair, with a stay pipe portion cut away.

FIG. 7 is a front view of the centrifugal clutch in a power-off state.

FIG. 8 is a front view of the centrifugal clutch in a power connection state.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Wheelchair 34 Drive wheel 35 Electric motor 38 Centrifugal clutch 71 Acceleration / inclination sensor (detection means, acceleration sensor, inclination sensor) A Power assist device B Reduction mechanism

Claims (6)

[Claims] 1. A power assist device formed by unitizing an electric motor, a speed reduction mechanism, and a drive wheel is provided, and the power assist device is placed in a center of a lower space portion of a wheelchair in a left-right direction with the drive wheel in contact with the ground. A wheelchair with a power assist device, wherein the wheelchair is provided in a wheelchair. 2. The wheelchair with a power assist device according to claim 1, wherein the width of the power assist device can be reduced. 3. The motor of the power assisting machine further includes a centrifugal clutch that includes detection means for detecting rotation of the electric motor, and connects and disconnects power transmission based on an output of the detection means. Wheelchair with power assist device as described. 4. The power assisting device according to claim 1, wherein the power assisting device is attached to the wheelchair so as to be rotatable in the front-rear direction, and the driving wheels of the power assisting device are biased in a direction in which the wheels contact the ground. Wheelchair with power assist device. 5. The wheelchair with a power assist device according to claim 1, wherein an acceleration sensor is attached to the wheelchair, and the driving of the electric motor is controlled by an output signal of the acceleration sensor. 6. The wheelchair with a power assist device according to claim 1, wherein an inclination sensor is attached to the wheelchair, and the driving of the electric motor is controlled by an output signal of the inclination sensor.