JPH10314234A - Wheelchair having power auxiliary machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the will of travel by a user or a carer on the basis of acceleration, and control a wheelchair on a sloping road by arranging control operation units having a brake means to respectively brake left and right wheels and an auxiliary quantity control means on the left and right of the wheelchair. SOLUTION: Respectively independent control operation units 72 are installed on the left and right in a frame 2 of a wheelchair 1 so as to be positioned on the front side of main driving wheels 16. The control operation units 72 have a control box fixed to the frame 2, and one end of a brake means is rotatably installed on a first support shaft of the control box, and a sensor unit to hold an inclination acceleration sensor (an auxiliary quantity control means) is rotatably installed on a second support shaft, and a link is rotatably installed on a third support shaft. Therefore, the left and right wheels 16 are independently controlled, and its turning can be easily performed.

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 assist device provided with a power assist device formed by unitizing an electric motor, a speed reduction mechanism, and drive wheels at a lower center portion of the wheelchair.

[0002]

2. Description of the Related Art Conventionally, as a wheelchair whose power is assisted by electric power, an operating wheel is connected to a driving wheel via torque detecting means as disclosed in Japanese Patent Laid-Open No. 15468/1991, and the torque is detected. Manual and electric motors are provided by attaching or detaching a device provided with a controller that controls the motor based on the value or a device that can be mounted on a general wheelchair and electrically operated as shown in Japanese Patent Application Laid-Open No. 6-86790. A mechanism that can be used for both of them has been proposed.

In Japanese Patent Application No. Hei 3-15468,
The present applicant has applied for a wheelchair with a power assist device in which power assist is provided by one driving assist wheel provided at a lower part of the wheelchair. That is, the driving force can be supplementarily provided based on the intention of the user or the caregiver to travel, and the provision of the auxiliary power is performed by detecting the intention of the traveling by the acceleration sensor. In addition, a tilt sensor is provided to automatically provide auxiliary power on an uphill.

[0004]

In a wheelchair that can be arbitrarily switched between manual operation and electric operation, the auxiliary power control during straight traveling can be controlled, but the operation is easy when turning right and left, and Nothing is considered safe.

According to the present invention, it is possible to perform a safe turning operation, detect a driving intention of a user or a caregiver based on acceleration, and perform a simple driving control operation on a slope. It is an object of the present invention to provide a wheelchair with a power assist device that can be obtained with a structure.

[0006]

According to the first aspect of the present invention,
In a wheelchair with a power assist device provided in the center lower part of a wheelchair with a power assist device formed by unitizing an electric motor, a reduction mechanism, and drive wheels, a brake means for braking each of the left and right wheels and a power assist amount by the electric motor are controlled. And a control operation unit provided with an auxiliary amount control means for controlling the wheelchair. Therefore, since the control operation units are provided on the left and right, the left and right wheels can be independently controlled to easily turn.

According to a second aspect of the present invention, the power assisting amount of the power assisting device when the brake is applied to one of the wheels is made smaller than the power assisting amount when the brake is not applied. Therefore, it is possible to avoid the risk of sudden turning during turning.

According to a third aspect of the present invention, there is provided a power assisting stop means for completely stopping power assisting when the power assisting amount of the power assisting device to the wheels on both sides becomes less than a predetermined value. Things. Therefore, since power assist is not performed before the brake is applied, turning and stopping can be performed reliably and safely.

According to a fourth aspect of the present invention, the auxiliary amount control means of the control operation unit is formed by an inclination / acceleration sensor which detects inclination and acceleration simultaneously. Therefore,
The driving intention of the user or the caregiver can be detected and controlled based on the acceleration, and the driving control on the slope can be performed at the same time.

According to a fifth aspect of the present invention, the control operation units are rotatably mounted on the left and right sides of the wheelchair. When the control operation units are tilted forward, the amount of auxiliary power increases, and when the control operation units are tilted forward, a brake is applied. The operation lever is attached to the. Therefore, the drive control of the wheelchair can be performed in a natural state according to the user's feeling, and a very easy-to-operate state can be obtained.

[0011]

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 (wheel) having a large diameter is rotatably mounted behind the side frame 3.
Outside these main drive wheels 16, there is a ring-shaped hand rim 17 having an outer diameter slightly smaller than the outer diameter of the main drive wheels 16.
Has been fixed.

Next, there is provided a power auxiliary machine 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.

On the stay holder 18 thus formed, a cylindrical boss portion 22 is formed so as to protrude 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, the frame stay 31 has a rotational speed detecting sensor 71 formed by a magnetic Hall element or the like.
Is attached. This rotation speed detection sensor 71
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. Then, the rotation speed detection sensor 71
And a control circuit connected to the motor 35. The operation of the electric motor 35 is controlled via the control circuit.

Next, the frame 2 of the wheelchair 1 has
Left and right independent control operation units 72 are mounted on the front side of the main drive wheels 16. The control operation unit 72 has a control box 73 fixed to the frame 2, and the control box 73 is provided with three support shafts 74, 75, 76 in a fixed manner.
One end of a brake assembly 78 (brake means) having a brake shoe 77 is rotatably mounted on the first support shaft 74, and an inclination / acceleration sensor 79 is mounted on the second support shaft 75.
Is held rotatably, and one link 82 of a link mechanism 81 is rotatably attached to the third support shaft 76. A tension spring 83 is coupled to the brake assembly 78 and urged clockwise, and the other link 85 of the link mechanism 81 is rotatably connected by a connection shaft 84. The other end of the link 85 and one end of the link 82 are rotatably connected by a connecting shaft 86, and an operating lever 87 is also rotatably connected to the connecting shaft 86. Also, at the lower end of the operation lever 87,
A drive pin 88 is fixed, and the drive pin 88 is slidably fitted in a vertically long slot 89 formed in the sensor unit 80.

Next, the specific structure of the sensor unit 80 will be described. First, the upper end of a leaf spring 91 is fixed to the support base 90. The leaf spring 91 has a large width dimension and a thickness of 0.05 to 0.05.
It is about 0.5 mm. At the lower end of such a leaf spring 91, a magnet holding base 92 serving as a weight is fixed. A permanent magnet 94 having a rectangular parallelepiped shape that is long in the bending direction of the leaf spring 91, that is, a shape that is long in the moving direction is mounted in a concave portion 93 that opens to the front side of the magnet holding base 92. The magnetized surface of the permanent magnet 94 is located in the front-rear direction (the left-right direction in FIG. 10 and the front-rear direction in FIG. 11). Next, the upper end of the PC board 95 is fixed to the support base 90. A magnetoresistive element 96 as a detecting means is attached to the PC board 95 at a position close to and opposed to the permanent magnet 94. As shown in FIG. 12, the magnetoresistive element 96 includes four variable resistance parts 97 bridge-coupled to each other. When a voltage is applied to the terminals, the magnetic resistance H changes. The output voltage is generated at the terminal based on the output voltage. Specifically, with respect to the magnetic field H, the variable resistance section 97 detects the magnetic field H in the direction of 45 ° left and right, and the difference between these two outputs appears as an output.

Next, the support base 90 is attached to a cover 98 having a magnetic shielding function. The cover 98 includes the leaf spring 91, the permanent magnet 94,
The outer periphery of the PC board 95 is covered. Further, the effective swing width of the permanent magnet 94 is set at a position facing both ends of the cover 98 in the moving direction of the permanent magnet 94.
A stopper 99 is fixed as a buffering control unit that controls the length to be equal to or less than 1/2 of the length.

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. There is also a usage method of operating the operation lever 87. In any case, when the wheelchair 1 starts moving from a stationary state, the inclination / acceleration sensor 79 detects the movement. At this time, in a use state in which the operation lever 87 is not operated, the position of the operation lever 87 is in the state shown in FIG.
It is assumed that the acceleration sensor 79 is in a vertical state. 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 inclination / acceleration sensor 79 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 electric motor 35, that is, the number of revolutions of the drive wheels 34 is set to a predetermined constant value based on a detection signal from the number-of-rotations detection sensor 71. That is, the rotation speed detection sensor 71 detects the teeth of the large-diameter driven gear portion 53 of the first intermediate gear 50 of the power transmission mechanism 36, and drives 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 inclination / acceleration sensor 79 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 acceleration by the inclination / acceleration sensor 79, and when the detection signal is a negative acceleration, the power supply to the electric motor 35 is cut off and stopped.

The operation of the inclination / acceleration sensor 79 will be described in more detail. First, when the wheelchair 1 is in a horizontal state, the state is as shown in FIG. 11A. If the wheelchair 1 is inclined forward or backward by an angle θ, FIG.
As shown in FIG. 1 (b) or FIG. 11 (c), the support table 90 is also inclined, the leaf spring 91 is deformed, and the position of the permanent magnet 94 is displaced with respect to the magnetoresistive element 96. The magnetized surface of the permanent magnet 94 is located such that the N pole faces the magnetoresistive element 96 as shown in FIG. FIG. 13 does not show the magnetoresistive element 96 itself, but shows a state in which the permanent magnet 94 has moved by m from the reference position O, and the magnetoresistive element 96 differs from the reference position O by 45 °. Detect the strength of the magnetic field in the direction. That is, when the permanent magnet 94 is located at the reference position O, the 45 °
Assuming that each of the variable resistance units 97 in different directions detects the magnetic field H, in the state shown in FIG.
Since the permanent magnet 94 is displaced by m, the variable resistance portion 9
7, one of the detected values is Hcosθ, and the other is Hcosθ.
sin θ. Therefore, the output from the circuit shown in FIG. 12 is an output corresponding to the difference between them, that is, H
The voltage is proportional to the value of × (cos θ−sin θ).
Therefore, assuming that a constant output is generated when the wheelchair 1 is in the horizontal state in FIG. 11A, the output voltage becomes as shown in FIG. 11B when the permanent magnet 94 is displaced forward. When the permanent magnet 94 is displaced backward as shown in FIG. 11C, the output voltage increases.

Although the wheelchair 1 has been described as being inclined in FIG. 11, if the movement of the wheelchair 1 includes acceleration, the permanent magnet 94 moves in a direction opposite to the direction in which the acceleration acts. The acceleration can be detected in exactly the same manner as when the wheelchair 1 is tilted.

The shape of the permanent magnet 94 may be long as long as it is long in the moving direction, and may be formed in a disk-like circle when viewed from above. FIG. 14 shows the distribution state of the magnetic flux density at the observation point when the diameter of the permanent magnet 94 is 4d and the distance between the permanent magnet 94 and the magnetoresistive element 96 changes to d, 1.5d, and 2d. FIG. 15 shows an output change state when the permanent magnet 94 having such a magnetic flux density distribution moves. That is, in FIG. 15, the horizontal axis indicates the moving distance of the permanent magnet 94 having a diameter of 4d, and the vertical axis indicates the output at that time. Therefore, when the amount of movement is small, the relationship between the amount of movement and the output shows linearity. However, when the amount of movement increases, the value of the detection output decreases, and the linearity disappears. In the state shown in FIG. 15, even if the distance between the permanent magnet 94 and the magnetoresistive element 96 changes to three types, d, 1.5d, and 2d, in any case, the amount of movement up to about 1/2 of the diameter In the range, the linearity is indicated.

However, in practice, the permanent magnet 94
Is determined by the stopper 99 so as to be equal to or less than 1/2 of its length. The necessity of such a definition is the first reason for obtaining an effect of hastening the damping of the vibration of the permanent magnet 94 when receiving a strong shock or acceleration, and to make the output of the magnetoresistive element 96 have linearity. This is because of the second reason.

First, the first reason is as follows.
Since the amount of deflection of 4 is small, the amount of deformation of the leaf spring 91 is inevitably reduced, so that an excessive force does not act on the movable part, and the vibration is rapidly damped. Therefore, the structural strength is also high. Next, the second reason is as described above with reference to FIG. 15 as described above.

Next, the operation when the user operates the operation lever 87 will be described. First, the state shown in FIG. 9B is the neutral position, and the operation of the inclination / acceleration sensor 79 is as described above. Then, when the operation lever 87 is tilted forward as shown in FIG. 9A, the electric motor 35 is driven, and as shown in FIG.
Is tilted backward, the brake shoe 77 is pressed against the outer peripheral surface of the main drive wheel 16 to exhibit a braking action.

That is, as shown in FIG. 9A, when the operating lever 87 is tilted forward, the operating lever 87 rotates about the coupling shaft 86, and the driving pin 88 is connected to the sensor via the elongated hole 89. The unit 80 is pressed and the sensor unit 80 is pressed.
Rotates clockwise about the support shaft 75 by α degrees.
This state is equivalent to a state in which the wheelchair 1 is located on an uphill or is accelerated by applying a driving force by a user or a caregiver, and is controlled so that the electric motor 35 applies auxiliary power. That is, the output from the magnetoresistive element 96 is subjected to arithmetic processing by an arithmetic processing circuit acting as auxiliary amount control means (not shown), and a control output is output. Therefore, by appropriately adjusting the operation amount of the operation lever 87 by the user, an arbitrary level of the power assisting amount can be selected according to the user's will. Of course, the inclination / acceleration sensor 79 provided in the sensor unit 80
As described above, since the inclination and the acceleration of the wheelchair 1 are detected, the driving control when the operation lever 87 is operated is performed in a state where the driving control is superimposed on the inclination and the acceleration.

Next, the right or left operation lever 87 is moved in FIG.
A state where the main drive wheel 16 on one side is braked by pulling forward as shown in FIG. When the operation lever 87 is pulled toward the user, the drive pin 88 is moved around the support shaft 75 to the sensor unit 8.
0 is rotated counterclockwise by β degrees. At the same time, the rotation of the sensor unit 80 is limited to a certain range by a stopper (not shown).
8, the coupling shaft 86 moves to the right, and the brake assembly 78 is rotated counterclockwise to
7 is pressed against the main drive wheel 16 to exhibit a braking action. The inclination of the sensor unit 80 at this time is the same as the state in which the wheelchair 1 is on a downhill, and the driving by the electric motor 35 is stopped.

When one of the main drive wheels 16 is braked by operating one of the operation levers 87, the electric motor 3
If the drive of No. 5 is controlled based on the posture of the other sensor unit 80, that is, if the drive state is continued without any change, there is no change in the traveling speed even in the turning state, which is dangerous. Therefore, in the present embodiment, when one of the main driving wheels 16 is braked, the traveling speed is reduced by performing the auxiliary driving by the electric motor 35 in a weak state. As a result, the vehicle is driven at a gentle speed, so that the vehicle does not roll over and safety is ensured.

Next, when trying to stop during traveling, the operation levers 87 on both sides are simultaneously pulled to the front side. As a result, the main drive wheels 16 on both sides are simultaneously braked by the brake shoes 77. However, in this embodiment, when the operation levers 87 on both sides are pulled to the near side,
Immediately before the brake shoe 77 comes into contact with the outer periphery of the main drive wheel 16, the drive by the electric motor 35 is released by the power assist stop means. Therefore, braking can be performed efficiently. Therefore, it is possible to safely go down a downhill while applying the brake, and since the auxiliary power drive is stopped before the brake is applied, useless consumption of the battery is prevented.

[0037]

According to the first aspect of the present invention, there is provided a wheelchair with a power assist device provided at a lower center portion of a wheelchair with a power assist device formed by unitizing an electric motor, a reduction mechanism, and drive wheels. Since the control operation unit including the brake means for braking and the auxiliary amount control means for controlling the power assist amount by the electric motor is provided on the left and right sides of the wheelchair, the control operation units are provided on the left and right, so that the left and right wheels are provided. Can be controlled independently so that the turning can be easily performed.

According to the second aspect of the present invention, the power assisting amount of the power assisting machine when one wheel is braked is made smaller than the power assisting amount when no brake is applied. This has the effect that the danger of rolling over can be avoided.

According to a third aspect of the present invention, there is provided a power assisting stop means for completely stopping power assisting when the power assisting amount of the power assisting device to the wheels on both sides becomes less than a predetermined value. Therefore, since power assist is not performed before the brake is applied, there is an effect that turning and stopping can be performed reliably and safely.

According to the fourth aspect of the present invention, since the auxiliary amount control means of the control operation unit is formed by the inclination / acceleration sensor which detects inclination and acceleration simultaneously, the intention of the user or the caregiver to travel is detected by the acceleration. And the drive control on the slope can be performed at the same time.

According to a fifth aspect of the present invention, when the control operation unit is tilted forward, the amount of auxiliary power is increased, and when the control operation unit is tilted forward, an operation lever is attached so that a brake is applied and the control operation unit is rotatably mounted on the left and right sides of the wheelchair. Therefore, the driving control of the wheelchair can be performed in a natural state in accordance with the sense of the user, and there is an effect that a very easy-to-operate state can be obtained.

[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.

9A and 9B show a control operation unit, wherein FIG. 9A is a vertical side view in a state where an operation lever is tilted forward, FIG. 9B is a vertical side view in a neutral position, and FIG. It is a vertical side view of the pulled braking state.

FIG. 10 is a vertical sectional side view of the inclination / acceleration sensor.

FIG. 11 shows a state where the PC board is removed.
(a) is a front view when the detected object is in a horizontal state, (b)
FIG. 4 is a front view of a state where the detected object is tilted forward, and FIG. 4C is a front view of a state where the detected object is tilted backward.

FIG. 12 is a circuit diagram equivalently showing a configuration of a magnetoresistive element.

FIG. 13 is an explanatory diagram showing a state of magnetic flux detected in directions different by 45 ° when the permanent magnet moves.

FIG. 14 shows a distribution state of a magnetic flux of a permanent magnet.
(a) is an explanatory diagram when the distance between the permanent magnet and the magnetoresistive element is d, and (b) is a diagram where the distance between the permanent magnet and the magnetoresistive element is 1.5.
FIG. 4C is an explanatory diagram in the case of d 2, and FIG. 4C is an explanatory diagram in the case where the distance between the permanent magnet and the magnetoresistive element is 2d.

FIG. 15 is a graph showing the relationship between the movement of the permanent magnet and the detection output.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wheelchair 16 Wheel 34 Drive wheel 35 Electric motor 72 Control operation unit 78 Brake means 79 Incline / acceleration sensor A Power assist device B Reduction mechanism

Claims (5)

[Claims] 1. A wheelchair with a power assist device provided at the center lower portion of a wheelchair with a power assist device formed by unitizing an electric motor, a speed reduction mechanism, and drive wheels, and a brake means for braking each of left and right wheels and the motor. A wheelchair with a power assist device, wherein a control operation unit having an auxiliary amount control means for controlling a power assist amount is provided on left and right sides of the wheelchair. 2. The power as claimed in claim 1, wherein the power assisting amount of the power assisting machine when one of the wheels is braked is made smaller than the power assisting amount when the brake is not applied. Wheelchair with assistive device. 3. A power assisting stop means for completely stopping power assisting when the power assisting amount of the power assisting device to the wheels on both sides becomes less than a predetermined value. Item 4. A wheelchair with a power assist device according to item 1. 4. The wheelchair with a power assist device according to claim 1, wherein the auxiliary amount control means of the control operation unit is formed by an inclination / acceleration sensor which detects inclination and acceleration at the same time. 5. A control operation unit is rotatably mounted on the left and right sides of a wheelchair, and an operation lever is mounted on these control operation units such that an auxiliary power amount increases when the control operation unit is tilted forward and a brake is applied when the control operation unit is tilted forward. The wheelchair with a power assist device according to claim 1 or 4, wherein: