WO2003024379A1

WO2003024379A1 - Front wheel support mechanism for wheelchair

Info

Publication number: WO2003024379A1
Application number: PCT/JP2002/009248
Authority: WO
Inventors: Koji Yoshioka
Original assignee: Aruze Corp.
Priority date: 2001-09-12
Filing date: 2002-09-11
Publication date: 2003-03-27
Also published as: JP2003079671A; TW558441B

Abstract

A front wheel support mechanism for a wheelchair capable of damping vibration and impact applied from irregularities and obstacles on a road surface to an occupant and reducing the occupant's feeling of fear of turning over, wherein a suspension mechanism (5) having a crank shaft structural body (50) and a magnet gear (55) is installed at the lower end part of a body frame of the wheel chair through a connection part (2), a plane rotating part (3), and a support member (41), the crank shaft structural body further comprising a horizontal support shaft (51) rotatably supported by the lower end part of the support member, an axle (52) for rotatably supporting a front wheel (1), and an arm (53) positioned perpendicular to the horizontal support shaft and the axle and connecting one end of the horizontal support shaft to one end of the axle.

Description

Description Front wheel support mechanism for wheelchairs Technical field

The present invention relates to a support mechanism for supporting a front wheel of a wheelchair. Background art

Wheelchairs are a substitute for those with lower body handicap due to accidents, illness, and the elderly. Wheelchairs were mainly used indoors, but as society has become more barrier-free, they have become more and more used outdoors. Along with that, the vibration and impact received by the occupants from unevenness on the road surface and obstacles have become a serious problem. For handicapped occupants, vibrations and shocks can further harm health. In a conventional general wheelchair, the front wheels made of solid tires having a small diameter are simply supported on the body frame as they are, so that the above-mentioned vibrations and shocks are hardly alleviated. Therefore, in recent years, a mechanism 10 for supporting the front wheel 1 via a spring 11 as shown in FIG. 9 (a) has been adopted. By the way, in wheelchairs, the distance between the front and rear wheels is small. Also, when an occupant gets in a wheelchair, the center of gravity increases due to the heavy head. Therefore, the wheelchair on which the occupant rides is never stable. Disclosure of the invention

(Technical problems to be solved by the invention)

In a wheelchair employing the above mechanism 10, if the spring 11 is soft, the following problems occur.

(1) If the occupant gets off the center of the wheelchair while riding, the spring 11 contracts and the wheelchair tilts.

(2) When the occupant leans to pick up an object on the road surface 3, the spring 11 contracts and the wheelchair tilts.

(3) In Fig. 9, the wheelchair travels in the direction of arrow A, and the front wheels 1 Thus, when colliding with an obstacle 61, the spring 11 contracts, causing the front side of the wheelchair to sink by H1, thereby causing the occupant to lean forward.

Thus, if the spring 11 is soft, the occupant will feel the fear of falling. Conversely, if the spring 11 is hard, the vibration and impact received by the occupant due to irregularities on the road surface are hardly alleviated.

An object of the present invention is to provide a front wheel support mechanism for a wheelchair, which can reduce vibration and impact received by an occupant from unevenness or obstacles on a road surface and can reduce a fear of falling of the occupant.

(How to solve it)

The invention according to claim 1 is a support mechanism for supporting a front wheel of a wheelchair, further comprising a suspension mechanism for rotatably supporting the front wheel at a lower end portion of a body frame, wherein the suspension mechanism has a crankshaft structure. The crankshaft structure includes a horizontal support shaft rotatably supported at the lower end of the body frame, an axle rotatably supporting the front wheels, and a horizontal support shaft and an axle. And an arm that is positioned at a right angle and connects one end of the horizontal support shaft and one end of the axle.

The invention according to claim 2 is the invention according to claim 1, wherein the suspension mechanism includes a control means for controlling a rotation operation of the horizontal support shaft, and the control means includes: It is controlled so that it is easier to take a state that is vertically lower than a state that is directly above the support shaft.

The invention according to claim 3 is the invention according to claim 1, wherein a support member is connected to a lower end portion of the vehicle body frame, and the support member is capable of swinging vertically. In addition, the upward swing receives the resistance of the elastic body, and the horizontal support shaft is rotatably supported at the lower end of the support member.

The invention described in claim 4 is the invention according to claim 3, wherein the support member is rotatable around a vertical axis.

(Advantageous advantages over conventional technology)

According to the invention described in claim 1, when the front wheel collides with an obstacle on the road surface or gets over a bump, the crankshaft structure rotates rearward around the horizontal support shaft. However, impacts from obstacles can be escaped to the rear. Therefore, the road surface Shock and vibration received by the occupant from the unevenness and obstacles above can be reduced, and the occupant's riding comfort can be improved.

In addition, when the front wheel goes down the step, the moment the front wheel passes the step, the crankshaft structure rotates around the horizontal support shaft, and the axle is positioned vertically below the horizontal support shaft. When the vehicle lands on the road, the crankshaft structure rotates around the horizontal support shaft and the axle is positioned vertically above the horizontal support shaft, so that the impact on the occupant during landing can be reduced. Therefore, also from this point, the ride comfort of the occupants can be improved.

According to the second aspect of the present invention, the control means promotes the rearward rotation of the crankshaft structure about the horizontal support shaft, and the rotated crankshaft structure attempts to return to the original position. Therefore, the operation of the crankshaft structure can be satisfactorily performed, and the effect based on claim 1 can be satisfactorily exhibited. Therefore, the ride comfort of the occupant can be improved.

According to the third aspect of the invention, when the front wheel collides with an obstacle on the road surface or climbs over a bump, the support member swings upward against the elastic body. You can release the fire upward. Also, in the event of a collision, the support member comes forward with respect to the front wheels in combination with the operation of the crankshaft structure, so that the amount of displacement in the traveling direction at the time of the collision can be lengthened. Instant shock can be reduced. Therefore, the impact received by the occupant from obstacles and unevenness can be further reduced, and the occupant's riding comfort can be improved.

In addition, when the front wheel collides with an obstacle on the road surface or climbs over unevenness, the rotation of the crank shaft structure to the rear and the swing of the support member to the rear link the support member. Since the vertical movement of the body frame is canceled out, it is possible to suppress the sinking of the front side of the wheelchair, and to curb forward. Therefore, the occupant's fear of falling can be reduced.

According to the invention set forth in claim 4, conversion of the running direction by the front wheels can be easily performed. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a partial longitudinal sectional side view of a wheelchair front wheel support mechanism of the present invention.

FIG. 2 is a partial longitudinal sectional front view of the mechanism of FIG.

FIG. 3 is a perspective view of a crankshaft structure.

FIG. 4 is a sectional view showing the operating principle of the magnet gear.

FIG. 5 is a side view showing the operation of the mechanism in FIG. 1 at the time of a collision with an obstacle.

FIG. 6 is a side view showing the operation of the mechanism of FIG. 1 when descending a step. FIG. 7 is a partial longitudinal sectional side view of a wheelchair front wheel support mechanism of another example of the present invention. FIG. 8 is a partial longitudinal sectional front view of the mechanism of FIG.

FIG. 9 is a side view showing the operation of a conventional front wheel support mechanism for a wheelchair at the time of a collision with an obstacle. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a partial longitudinal sectional side view of a wheelchair front wheel support mechanism of the present invention, and FIG. 2 is a partial longitudinal sectional front view of the same. The support mechanism includes a connecting part 2, a plane rotating part 3, a swing mechanism 4, and a suspension mechanism 5.

The connecting portion 2 has a vertical rotation shaft 23 in a cylindrical body 21 via a ball bearing 22. The plane rotating unit 3 is fixed to the lower end of the vertical rotating shaft 23. As a result, the plane rotation unit 3 rotates in a plane with the rotation of the vertical rotation shaft 23.

The swing mechanism 4 includes a support member 41 and a spring 42. The upper end of the support member 41 is rotatably connected to the plane rotating portion 3 by the horizontal shaft 43, whereby the support member 41 swings up and down. The support member 41 is provided to be inclined rearward. The support member 41 has a rearward projecting portion 411. The spring 42 is provided between the rearward projecting portion 4 11 and the plane rotating portion 3 so as to resist when the support member 41 swings upward.

At the lower end of the support member 41, a suspension mechanism 5 that rotatably supports the front wheel 1 is provided. The suspension mechanism 5 includes a crankshaft structure 50. The crank shaft structure 50 includes a horizontal support shaft 51 rotatably supported at the lower end of the support member 41, an axle 52 rotatably supporting the front wheel 1, a horizontal support shaft 51, and Axle 5 2 And an arm 53 that is positioned at a right angle to and connects one end of the horizontal support shaft 51 and one end of the axle 52. The horizontal support shaft 51 is supported by the support member 41 via a ball bearing 511. The axle 52 is supported by the front wheel 1 via a ball bearing 52 1. FIG. 3 is a perspective view of the crankshaft structure 50. FIG.

The suspension mechanism 5 further includes control means for controlling the rotation operation of the horizontal support shaft 51. The control means comprises a magnet gear 55. When the axle 52 is vertically above the horizontal support shaft 51 in the crankshaft structure 50, as shown in FIG. 4 (a), the magnet gear 55 The pole and the north pole and the south pole and the north pole on the support member 41 side are provided such that the poles face each other. Accordingly, the magnetic gear 55 changes the relationship between the horizontal support shaft 51 and the support member 41 from the state shown in FIG. 4A to the state shown in FIG. Act to make it work.

Next, the operation of the support mechanism having the above configuration will be described. FIG. 5 (a) shows the state before the collision, and FIG. 5 (b) shows the state at the time of the collision.

As shown in Fig. 5, when the wheelchair travels in the direction of arrow A and the front wheel 1 collides with an obstacle 61 on the road surface 6, the crankshaft structure 50 moves backward around the horizontal support shaft 51 (arrow B). ), The impact f received from the obstacle 6 1 is released to the rear, and at the same time, the support member 4 1 moves upward (arrow C) around the horizontal axis 4 3 against the spring 4 2. Direction), the impact f is released upward. Moreover, at the time of a collision, the actuation of the above, since the support member ⁴ 1 is in a state of out forward relative to the front wheel 1, when the displacement amount S 2 in the running direction of the collision of the conventional FIG. 9 S 1 It is longer than. As the length increases, instantaneous impacts are reduced.

Accordingly, the impact received by the occupant when colliding with the obstacle 61 is reduced. When the vehicle travels over bumps and dips on the road surface 6, the vibrations and impacts experienced by the occupants are reduced by the same operation. Therefore, good ride comfort can be obtained.

Further, as described above, when the front wheel 1 collides with the obstacle 61, the crankshaft structure 50 rotates around the horizontal support shaft 51 in the direction of arrow B, and the support member 41 also moves. The horizontal axis 4 swings in the direction of arrow C in the direction of arrow C, so that the movements of the two cancel each other up and down fluctuations of the plane rotating part 3, and the sinking amount H2 of the plane rotating part 3 is Is very small compared to H 1 in the case of. Therefore, front turning at the time of collision is suppressed. Is done.

Further, as shown in FIG. 6, when the front wheel 1 descends on the large step 62, the suspension mechanism 5 operates as follows.

In the state (a) of FIG. 6, the magnet gear 55 is in the state (a) of FIG. Therefore, the magnet gear 55 tries to rotate the crankshaft structure 50 around the horizontal support shaft 51. In such a state, when the wheelchair travels in the direction of arrow A and the front wheel 1 passes over the step 62, at that moment, as shown in (b), the crankshaft structure 50 becomes the horizontal support shaft 51. Rotating around, the axle 52 is positioned vertically below the horizontal support shaft 51. That is, the magnet gear 55 is in the state of (b) in FIG. Then, when the front wheel 1 lands on the road surface 6, the crankshaft structure 50 rotates around the horizontal support shaft 51 while resisting the force of the magnet gear 55, as shown in (c). The axle 52 is positioned vertically above the horizontal support shaft 51.

Thus, when the front wheel 1 descends the step 62, the crankshaft structure 50 is forcibly and instantaneously brought to the state of (a) force (b) by the action of the magnet gear 55, c) When the front wheel 1 descends the step 62 as in the case of the spring force, it rotates around the horizontal support shaft 51 while resisting the force of the magnet gear 55 in the state of c). The impact on the occupants is reduced.

The magnet gear 55 acts so that the above-described operation of the crankshaft structure 50 can be satisfactorily performed even when the front wheel 1 collides with the obstacle 61 or gets over unevenness. That is, the magnet gear 55 promotes the rotation of the crankshaft structure 50 backward about the horizontal support shaft 51, and prevents the rotated crankshaft structure 50 from returning to the original position. Since it acts to suppress, the above-described operation of the crankshaft structure 50 is favorably exhibited, and the impact vibration is further reduced.

As described above, in the support mechanism having the above configuration, the impact and vibration received by the occupant from the obstacle 61, the unevenness, and the step 62 force are reduced, so that a good ride comfort can be obtained. In the case of the vehicle, too, since the turning in front of the collision is suppressed, the occupant's fear of falling is reduced.

7 and 8 show another example of the front wheel supporting mechanism for a wheelchair of the present invention. FIG. 7 is a partial longitudinal sectional side view, and FIG. 8 is a partial longitudinal sectional front view. Support for this example and the above configuration The difference from the mechanism is that the front wheel 1 is cantilevered by the support member 41, and that the rocking mechanism 4 uses a piston mechanism 44 instead of the spring 42. In this example, the same reference numerals as those in FIGS. 1 and 2 denote the same or corresponding components. The piston mechanism 44 includes a cylinder 442 rotatably connected to the plane rotating unit 3 by a horizontal shaft 441, and a piston 4444 rotatably connected to the support member 41 by a horizontal shaft 43. , Rubber material 4 4 5 and The piston 444 is fitted into the cylinder 442 via a rubber member 445. In this example, when the support member 41 moves upward around the horizontal axis 43, the piston 444 moves in the direction of arrow D while piled on the force of the rubber member 445.

Note that a known coil spring, hydraulic damper unit, or the like may be used instead of the piston mechanism 44.

Claims

The scope of the claims

1. In the support mechanism that supports the front wheel of the wheelchair,

A suspension mechanism (5) that rotatably supports the front wheel (1) at the lower end of the body frame is provided.

The suspension mechanism includes a crankshaft structure (50), the crankshaft structure rotatably supports a horizontal support shaft (51) rotatably supported at a lower end portion of a vehicle body frame, and a front wheel. An axle to be supported (52); and a horizontal support shaft and an arm (53) positioned at right angles to the axle and connecting one end of the horizontal support shaft and one end of the axle. Front wheel support mechanism for wheelchairs.

2. The suspension mechanism includes control means for controlling the rotation of the horizontal support shaft, and the control means is easier to adopt when the axle is vertically below the vertical support shaft than when it is vertically above the horizontal support shaft. The wheelchair front wheel support mechanism according to claim 1, wherein the mechanism is controlled so as to cause the wheelchair to rotate.

3. A support member (41) is connected to the lower end of the vehicle body frame, and the support member can swing up and down, and the upward swing receives resistance of the elastic body. 2. The front wheel support mechanism for a wheelchair according to claim 1, wherein the 7_K flat support shaft is rotatably supported at a lower end portion of the support member.

4. The front wheel support mechanism for a wheelchair according to claim 3, wherein the support member is rotatable about a vertical axis.