JP4446484B2 - Electric wheelchair - Google Patents

Description

  The present invention relates to a four-wheel drive electric wheelchair including a pair of left and right directional front wheels and a pair of left and right front-rear rotating rear wheels.

  Patent Document 1 discloses a non-turning directional wheel or an omnidirectional wheel in which cylindrical rotors that can rotate in a direction orthogonal to a straight traveling direction of a wheel are arranged on a rim around a hub, It is described that an omnidirectional vehicle capable of moving to 360 ° including the direction is realized. Further, according to Patent Document 2, a pair of left and right directional front wheels and a pair of left and right front-rear rotating rear wheels are provided, and left and right independently so that they can be steered differentially without depending on wheel steering. A four-wheel drive type electric wheelchair is disclosed in which the front wheel rotor has a plurality of semi-spindle shapes and the treads of the front and rear wheels are set to be the same as each other while being rotated. This type of rotor is known from Patent Document 3, and a semi-spindle-shaped tip part partially penetrates into a recess formed in the base end part so that the base part can be adjacent to the adjacent base end part. ing.

JP 11-227404 A JP 2004-344289 A JP 2002-137602 A

  In the case of a four-wheel drive type mobile vehicle that enables steering by the difference between the left and right rotational travel distances according to Patent Document 1, the traveling direction is disturbed by the rotation of the rotor when one of the wheels slips, or the traveling surface is In the case where the rotor is inclined laterally with respect to the traveling direction, there is a problem with a so-called single flow phenomenon in which the rotor rotates and meanders downward. Moreover, when such a wheel with a rotor is used, it is easy to produce rattling by the clearance gap between rotors especially outdoors.

  On the other hand, according to the front-rear wheel-coupled four-wheel drive electric wheelchair in which only a pair of left and right front wheels are freely directional according to Patent Document 2, disturbance in the traveling direction or single flow phenomenon is suppressed, and the tread of the front and rear wheels is suppressed. Is the same, the transmission loss of power is suppressed at the time of steering, and the semi-spindle-shaped rotor that can be close to each other eliminates a gap and can smoothly run on sandy beaches and rough roads. However, when the rear wheel is a front-rear rotation type tire wheel, even if outdoor running performance is ensured, the floor surface is easily damaged during indoor steering, and steering with a small turn becomes difficult.

  The present invention requires a wheelchair capable of four-wheel drive including a directional front wheel and a front / rear rotating rear wheel, in view of the fact that it is preferable to make a small turn by omnidirectional movement particularly indoors compared to the outdoors. An object is to provide an electric wheelchair that can be switched to an omnidirectional wheelchair.

In order to achieve this object, according to the present invention, a pair of left and right directional front wheels in which a plurality of rotors rotating in a direction perpendicular to the front-rear direction of the floor frame are arranged around the floor frame according to claim 1 and In an electric wheelchair comprising a pair of left and right front and rear rotating rear wheels, the left front and rear wheels and the right front and rear wheels being driven by a differential four-wheel motor in response to a steering command signal A plurality of rotors (2a) that are arranged laterally along the direction orthogonal to the floor frame front-rear direction between (2L, 2R), are driven to rotate by a motor, and rotate in the front-rear direction of the floor frame are arranged around The direction-reversible rollover rear wheel 2T and the rollover rear wheel and rear wheel (2L, 2R) are provided on the floor frame (8, 9) so as to be movable up and down. Rear wheel (2 ) With either a wheel lifting actuator for one selectively lowering the ground (30), left front wheel in a state in which rollover rear wheel (2T) has been in contact with the ground (1L), the right front wheel (1R) and after rollover Wheel drive control means (41, 5, 5a, 42L _, 42R, 42T) for driving the wheels (2T) in response to a steering command signal to drive three wheels differentially instead of driving four wheels. Features.

When driving four wheels, the left front and rear wheels (1L , 2L) and the right and left front wheels (1R _, 2R) are rotated differentially by the wheel drive control means (41, 5, 5a, 42L _, 42R, 42T) in common with each side in the rotational direction and rotational traveling speed. Steering is performed under the driving control. The front wheels (1L, 1R) are steerable so that the wheels are steered in a non-turning state. During three-wheel drive in which the left and right rear wheels (2L, 2R) are lifted and the rollover rear wheel (2T) is in contact with the ground, the directional front wheels (1L, 1R) and the unidirectionally movable rollover The wheels (2T) are steered in a rotational differential manner so that the vehicle body, that is, the floor frames (8, 9) can be translated in all directions without turning, and the left and right front wheels rotate in reverse directions. Spin rotation is also performed at the same rotational traveling speed of (1L, 1R) and the rollover rear wheel (2T).

According to claim 2, the left front and rear wheels (1L _, 2L) and the right front and rear wheels (1R _, 2R) are connected to each other via a belt (4) according to claim 2, A motor is attached to one of the front and rear wheels, or a pair of front wheels (1L, 1R) according to claim 3. ) And a pair of rear wheels (2L, 2R) are provided with motors. In order to easily switch the grounding wheel, according to claim 4, the floor frame is attached to the upper floor frame (8) provided with the seating portion and the wheel lifting / lowering actuator (30) and the rear wheel (2L, 2R). And a lower floor frame (9) supported by the upper floor frame (8) so as to be swingable up and down, and is driven up and down by a wheel elevating actuator (30) on the upper floor frame portion. The rotation mechanism (32, 33) for supporting the rollover rear wheel (2T) is pivotally mounted, and the rotation mechanism is linked to the grounding of the rollover rear wheel (2T) by the downward rotation. A frame drive unit (39) for swinging the lower floor frame (9) upward is additionally provided.

  According to the first aspect of the present invention, driving performance is ensured by the four-wheel drive in which only the front wheel is a wheel with a rotor outdoors, and steering can be performed without turning the wheel by utilizing the characteristics of the omnidirectional wheel. . Also, especially in the interior, by driving the three wheels with the rear wheels rolling down, it becomes possible to steer in any direction without turning over, including movement in the orthogonal direction, parallel movement in the oblique direction, or spin rotation. .

  According to the invention of claim 2, four wheels can be driven in an interlocking manner by one motor on each of the left and right sides, and according to the invention of claim 3, the rear wheels can be stopped when driving three wheels. According to the fourth aspect of the present invention, the rear wheel can be levitated in conjunction with the pivoting mechanism that is pivotally attached to the upper floor frame portion and supports the rear rolling wheel by the actuator.

A 4 / 3-wheel-switchable electric wheelchair according to an embodiment of the present invention will be described with reference to FIGS. This electric wheelchair includes an upper floor frame 8 to which a seat portion 3 is attached, and a directional front wheel 1L with a rotor 1a. , 1R and normal rear-rotating rear wheel with tire 2L , 2R and a lower floor frame 9 connected to the upper floor frame 8 via a frame connecting link 10 (FIGS. 2 and 3) at an intermediate position, and a pair of rear frames Wheel 2L , 2R, a freely rotating roll rear wheel 2T with a rotor 2a disposed laterally along a direction orthogonal to these rear wheels, and a wheel raising / lowering actuator 30 provided on the upper floor frame 8 is provided. (Figures 2 and 3), rear wheel 2L , 2R, the rear roll wheel 2T is selectively grounded. The treads of the front and rear wheels are the same.

Front wheel 1L , 1R are omnidirectional wheels that rotate in a direction orthogonal to the front-rear direction of the floor frames 8 and 9, or the straight direction of the wheels, around the rim around the center axle as described in Patent Document 3. A plurality of rotors 1a having the same shape are arranged. In addition, each rotor is formed in a semi-spindle shape, and the tip portion partially enters a conical concave portion formed in the proximal end portion of the adjacent rotor 1a and is close to the proximal end portion of the adjacent rotor 1a. It has come to be able to do. The overturning rear wheel 2T with the rotor 2a is also of the same freely rotating type.

As shown in FIGS. 2 and 3, the coil spring 7 a and the base end portion of the cylinder 6 filled with oil are connected to the upper floor frame 8 by pins 6 b in four directions between the upper floor frame 8 and the lower floor frame 9. A suspension spring 7 composed of an oil damper pivotally attached to the lower floor frame 9 and an oil damper pivotally attached to the lower floor frame 9 is interposed. The frame connection link 10 has a base end portion pivotally attached to a floor support arm 15 provided on the upper floor frame 8 and a pin 11 provided on the lower floor frame 9, and a distal end portion of the floor support arm 15. The link arm 12 is pivotally attached to the lower end by a pin 14. Thereby, the horizontal twist between the upper floor frame 8 and the lower floor frame 9 and the displacement in the front-rear direction are suppressed, and the lower floor frame 9 is a front wheel 1L rotatably supported at the front portion thereof. The suspension spring 7 can be expanded and contracted with the 1R axle as a fulcrum to swing up and down.

Left and right front and rear wheels 1L , 2L and right front and rear wheels 1R , 2R, a belt 4 is wound on each side around a pulley 3 provided on each axle, and a rear wheel 2L , 2R axles 1L are mounted on the rear portion of the lower floor frame 9 so as to be rotationally driven by a motor, respectively. , 2L and right front and rear wheels 1R , 2R are rotated forward and backward at variable speeds independent of each other on each side to perform four-wheel drive. A motor drive unit 5a is attached to the overturning rear wheel 2T so that the axle is rotated by a motor. And the three-wheel drive is performed by rotating forward and reverse at independent variable speeds with respect to the right front wheel 1R.

As shown in FIGS. 2 and 3, the wheel raising / lowering actuator 30 is pivotally attached to a hinge bracket 35c projecting from a cross portion 8a of a square-shaped upper floor frame 8, and the cylinder rod 35a A motor-type power cylinder 35 pivotally attached to a hinge bracket 35b provided below the support member 34 that holds the motor drive unit 5a at the front end, and support arms 31 on both sides provided below the cross portion 8a. The base end portion is pivotally attached, and the distal end portion includes parallel links 32 and 33 pivotally attached to both sides of the support member 34, respectively. The link arm 33 on the lower side of the parallel link as the rotating mechanism is extended from its base end to form a frame drive unit 39, whereby the rollover rear wheel 2T is lowered and grounded by the advancement of the cylinder rod 35a. In conjunction with this, the projecting pieces 9a projecting from the lower floor frame 9 on both sides are driven from below, and the lower floor frame 9 is moved to the front wheel 1L. , Swings upward with the 1R axle as a fulcrum.

  As shown in FIG. 4, the power cylinder 35 is responsive to an operation of a changeover switch 37 (shown schematically in FIG. 1) provided on an armrest on the right side of the seating portion 3 by an attached cylinder driving portion 38. Drive forward and backward. The left rear wheel 2L and the right rear wheel 2R are provided with a pair of left and right four-wheel drive drive units 42L and 42R for the motor drive unit 5 that rotate forward and reverse at mutually independent variable speeds. A motor drive unit 42T for a motor drive unit 5a that rotates forward and reverse at independent variable speeds is attached to the wheel 2T. Then, in response to an operation of a joystick 40 (also schematically illustrated) provided on the right armrest as a steering command means and an operation of the changeover switch 37, the rotation direction and differential rotation with respect to the motor drive units 42L, 42R, and 42T. Rotation command signal Ls for the rear wheel 2L, rotation command signal Rs for the rear wheel 2R, and rotation of the rear wheel 2T A rotation command data creation unit 41 that outputs a command signal Bs, motor drive units 5 and 5a that rotate the associated axle, and motor drive units 42L and 42R that drive these motor drive units in response to the rotation command signal. , 42T constitute wheel drive control means for four-wheel drive and three-wheel drive.

The joystick 40 corresponds to the Y-axis signal component Py in the front-rear direction of the potentiometer and the X-axis component signal Px in the orthogonal direction according to the tilt direction over 360 ° and the tilt amount at that position, and the rotational operation position of the joystick 40. The rotation signal component Pr is output as a steering command signal. The rotation command data creation unit 41 responds to these potentiometer signal components Py and Px during four-wheel drive, and provides a rotation command signal for instructing the rotation speed and rotation direction of the left and right rear wheels 2L and 2R and the rollover rear wheel 2T. Ls and Rs are output, while rotation command signals Ls, Rs and Bs are output in response to these potentiometer signal components Py, Px and Pr during three-wheel drive. The rotation command signal Bs takes into account the difference in outer diameter between the wheels, and the front wheel 1L , 1R and the rotational traveling speed of the roll over wheel 2T are set so that the rotational differential steering is appropriately performed.

FIG. 5A illustrates a steering state by speed control according to the tilting direction of the joystick 40 during four-wheel drive. That is, in the tilting operation at the 0 ° position (+ Y), the left front and rear wheels 1L , 2L and right front and rear wheel 1R , 2R responds to the rotation command signals Ls and Rs and rotates straight forward at a constant speed (FIG. 7A). Also, the speed increases according to the amount of tilt at that position. At the 180 ° position (-Y), the vehicle moves backward linearly by reverse rotation at a constant left and right speed. At the 90 ° position (+ X), the spin rotates to the right at the left forward rotation, right reverse rotation, and constant speed (FIG. B). On the contrary, at the 270 ° (−X) position, the left spin is performed at the right forward rotation, the left reverse rotation, and the constant speed (FIG. C).

  Further, at the intermediate positions at intervals of 90 °, the wheel on one side stops and turns. For example, at the 45 ° position, it turns left and turns right when stopped right (D in the figure). At the intermediate position between + 0 ° and 45 °, the right forward rotation speed gradually decreases, and at the position between 45 ° and 90 °, right reverse rotation starts, the relative speed gradually increases, and the degree of bending gradually increases. Hereinafter, as shown in the figure, when the tilt direction is changed in the direction of the arrow, the steering direction is changed by changing the relative ratio of the speeds according to the respective tilt positions.

During three-wheel drive, the left front wheel 1R in response to the rotation command signals Ls, Rs, Bs by the left rotation operation of the joystick 40 And the rear wheel 2R which floats forwards, the left front and rear wheels 1L , 2L with constant speed reverse rotation and forward rotation with the same rotational traveling speed as the front wheels 1L, 1R of the overturning rear wheel 2T, spin rotation is performed to the left (E in the figure). Moreover, it is accelerated according to the rotation amount. By rotating right, the right front wheel 1R , 2R reverse rotation, left front and rear wheels 1L , 2L with constant speed forward rotation and roll-back wheel 2T with constant speed reverse rotation to the right (S).

Further, FIG. 5B illustrates a steering state according to the tilting direction of the joystick 40 when driving three wheels. In response to the rotation command signals Ls, Rs, and Bs, at the 0 ° (+ Y) position, the rear wheel is overturned. 2T stop, left front wheel 1L And right front wheel 1R It moves forward in a straight line by forward rotation at a constant speed (G in the same figure), and retreats at a 180 ° (−Y) position by reverse rotation at a constant speed. Front wheel 1L at 45 ° position 1R In addition, by the constant speed forward rotation of the roll rear wheels 2T at the same rotational traveling speed, the vehicle body, that is, the floor frames 8 and 9 are translated in the 45 ° left direction without turning. Front wheel 1L at 90 ° position 1R front wheel with 1R stop and rollback wheel 2T forward With the rotation of the 1R rotor 1a, it traverses in the right-orthogonal direction (H in the figure). Front wheel 1L at 270 ° position The vehicle travels in the left-orthogonal direction with the stop of 1R and the reverse rotation of the rollover wheel 2T (Fig. I).

Hereinafter, as shown in the figure, when the tilt direction is changed in the direction of the arrow, the steering direction is changed by changing the relative ratio of the speeds according to the respective tilt positions. For example, the distance between the 270 ° position and the 180 ° position is 1L of the front wheel. 1R is reversely rotated and the rear wheel 2T is rotated in reverse and the relative speed is gradually increased to move diagonally backward. At the position of 225 °, the two wheels move parallel to each other at the same rotational speed and further to the rear wheel 2T. Decelerates and recedes straight at 180 °.

The operation of the electric wheelchair configured as described above is as follows. Outdoor, usually 2L rear wheel , 2R are grounded, and the overturned rear wheel 2T floats and travels by front wheel-linked four-wheel drive. As a result, the speed is controlled according to the tilt amount of the joystick 40 as described above, and the left front and rear wheels 1L according to the tilt direction. , 2L and right front and rear wheel 1R , 2R is steered in a rotational differential manner based on the mutual rotational direction and rotational speed difference. At that time, front wheel 1L 1R The front and rear wheels 1L , 2L; 1R , 2R is steered in a non-turning state, and the rear wheels 2L, 2R are tire wheels, so that running performance on rough roads is also ensured.

On the other hand, when the changeover switch 37 is operated indoors, the rear wheel 1L , 2R surface, and as shown in FIG. 6, the rollover rear wheel 2T is grounded instead. Accordingly, when the joystick 40 is tilted back and forth, as described above, the rear wheel 2L is rotated by the rotation of the rotor 2a while the rollover wheel 2T is stopped. , 2R idle rotation and front wheel 1R , 1L Depending on the direction of rotation, it moves forward or backward linearly.

When the joystick 40 is rotated, the spin is rotated in the rotation direction at a speed corresponding to the rotation operation amount as described above. At that time, compared to the four-wheel drive, the front wheel 1R , 1L of the rotor 1a as well as the rotor 2a of the rolling rear wheel 2T rotate, so that the spin is smoothly rotated without rubbing the floor surface. When the joystick 40 is tilted in the right and left orthogonal directions, the front wheel 1R is rotated by the forward rotation of the rollover rear wheel 2T. , 1L of the rotor 1a is rotated with the rotation of the rotor 1a to the right, or is rotated to the right with the reverse rotation.

At the operation position in the middle between 0 ° and 90 ° or 270 °, the front wheel 1L , 1R The left and right wheels 2T are steered differentially in the diagonal direction on the left side and the rear wheels 2T are rotated in the right direction. At that time, smooth steering is performed by rotating the rotors 1a, 2a in accordance with the longitudinal speed component in the oblique direction, and the vehicle body does not turn in the steering direction, but remains in the straight direction and the steering direction. Translate. Similarly, the vehicle is steered in an oblique direction in a reverse state at an operation position halfway between the 90 ° position and the 270 ° position. Further, when the tilting operation is repeated while rotating the joystick 40, the joystick 40 can be moved forward and backward while rotating and finely rotated. As a result, it is possible to move quickly and smoothly to the target position without the need for turning-back steering in a narrow room. Easily move between office desks.

  Furthermore, since the front wheel and the rollover wheel are free-wheeling wheels provided with semi-spindle-shaped rotors that can be adjacent to each other, the periphery of the wheel can be circular and can run smoothly without rattling. However, as another embodiment, the present invention is also applicable to a case where a freely rotating wheel having a well-known cylindrical rotor that may generate a gap between adjacent ones is employed. Not only the four-wheel drive system in which the left and right front and rear wheels are linked together, but also a motor drive unit is attached to each of the four front and rear wheels, and the rear wheels are stopped when three wheels are driven by the rollover rear wheel and the front wheel. It is also possible to configure the drive control means as a four-wheel drive type. The steering command means is not limited to the tilt-type joystick described above, and another configuration using a steering wheel type is also conceivable.

  In addition, the wheel raising / lowering actuator is not limited to the parallel link type turning mechanism, and it is also conceivable that the seesaw structure in the front-rear direction is swung by the actuator to switch and ground the lower floor frame and the rear rolling wheel. In addition, the description has been made on the assumption that the suspension frame is interposed in four directions between the upper floor frame and the lower floor frame and connected to each other by the frame connecting link. Other floor frame structures such as a swingable support on the upper floor frame independently are also conceivable. In particular, when a motor drive unit is attached to each of the four wheels, the speed is controlled so that the rotational traveling speeds of the front and rear wheels coincide with each other, and the tip of the oblique lower floor frame with the rear wheels is directly pivoted to the upper floor frame. It is also possible to swing the rear end portion of the lower floor frame upward in conjunction with the landing and grounding of the rollover rear wheel by the wheel lifting / lowering actuator.

1 is a perspective view of an electric wheelchair according to an embodiment of the present invention. The structure of the electric wheelchair is shown. FIG. A is an internal side view when the rear wheel is grounded, and FIG. B is a rear view. The structure of the electric wheelchair is shown, in which FIG. A is an internal side view when the rollover wheel is grounded, and FIG. B is a rear view. It is a figure which shows the structure of the drive control means of the same electric wheelchair. The operation of the joystick of the drive control means will be described. FIG. A is when the rear wheel is grounded, and FIG. FIG. 3 is a perspective view of the electric wheelchair when the wheel after rolling over is grounded. It is a figure explaining the steering mode of the electric wheelchair.

Explanation of symbols

1a, 2a rotor 1L , 1R Front wheel 2L , 2R Rear wheel 2T Rolling rear wheel 5, 5a Motor drive unit 7 Suspension spring 8 Upper floor frame 9 Lower floor frame 30 Lifting actuator 32, 33 Parallel link 35 Power cylinder 37 Changeover switch 39 Frame drive unit 40 Joystick

Claims (4)

Provided with a pair of left and right directional front wheels and a pair of left and right front and rear rear wheels, in which a plurality of rotors rotating in a direction orthogonal to the front and rear direction of the floor frame are arranged around, In an electric wheelchair in which the right and left front wheels are driven by a four-wheel drive differentially in response to a steering command signal,
A plurality of rotors arranged in a transverse direction along a direction orthogonal to the floor frame front-rear direction between a pair of left and right rear wheels, driven to rotate by a motor, and rotated in the front-rear direction of the floor frame are arranged around A unidirectional rollover rear wheel and a wheel lift that selectively lowers and grounds either the rear wheel or the rollover rear wheel by providing the rollover rear wheel and the rear wheel on the floor frame so that they can be raised and lowered. In response to a steering command signal, the front wheel on the left side, the front wheel on the right side, and the rear wheel on the right side are driven in response to a steering command signal, and the three wheels are differentially rotated. An electric wheelchair comprising wheel drive control means for driving.   The electric wheelchair according to claim 1, wherein the left and right front wheels and the right front and rear wheels are connected to each other via a belt, and a motor is attached to one of the front and rear wheels on each side.   The electric wheelchair according to claim 1, wherein a motor is attached to each of the pair of front wheels and the pair of rear wheels. The floor frame includes an upper floor frame provided with a seating portion and a wheel raising / lowering actuator, and a lower floor frame attached to the rear wheel and supported by the upper floor frame so as to be swingable up and down.
The upper floor frame portion is pivotally mounted with a rotating mechanism for supporting the rear roll wheel so as to be driven up and down by the wheel elevating actuator. The electric wheelchair according to any one of claims 1 to 3, further comprising a frame driving unit that swings the lower floor frame upward in conjunction with the grounding of the wheel.

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