JPH085291B2 - Wheel suspension for small vehicles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small vehicle such as a golf cart, and more particularly to a suspension system for its wheels.

[0002]

2. Description of the Related Art A golf cart for carrying golf equipment used by a player in a golf course, which is conventionally provided in a frame provided with wheels, as shown in, for example, Japanese Utility Model Publication No. 52-140858. It is known that a driver is provided in a space and a carrier for supporting a caddy bag is provided.

Since this conventional golf cart mainly travels at a low speed in a flat golf course with few undulations,
In many cases, no special cushioning mechanism is provided between the wheel and the frame.

[0004]

However, if the wheels are rigidly supported by the frame without a buffer mechanism, the impact from the road surface is directly transmitted to the driver. Therefore, in the riding golf cart as described above, there is a demand for providing some kind of cushioning mechanism between the wheels and the frame in consideration of riding comfort.

At this time, if a shock absorbing mechanism having a hydraulic shock absorber, which is adopted in a normal motorcycle or a passenger car, is provided, the structure of the suspension portion of the wheel becomes complicated, resulting in an increase in weight and cost. There is. Therefore, there is a problem that a vehicle such as a golf cart which is not required to have a high running performance is excessively equipped.

The present invention has been made under these circumstances, and a single rubber-like elastic member can efficiently exhibit a cushioning function. With a simple structure, weight reduction and cost reduction can be achieved. An object of the present invention is to provide a wheel suspension device for a small vehicle, which is capable of ensuring the durability of the rubber-like elastic body.

[0007]

In order to achieve the above object, a wheel suspension system for a small vehicle according to the present invention includes a frame, a front wall and a rear wall which are attached to the frame and face each other, and these front walls. And a rear wall, a metal bracket having a connecting wall extending in the vehicle width direction and a space portion surrounded by the front wall, the rear wall and the connecting wall of the bracket in the vehicle width direction. Is placed along the
A metal axle arm having a pressing surface that faces the connecting wall, a pivot shaft that pivotally supports the axle arm between the front wall and the rear wall of the bracket in the vertical direction, and the axle arm. A wheel supported by the left and right lateral ends of the bracket, and a wheel fixed to the bracket and holding the axle arm in a vertically swingable manner at a position separated from the left and right sides by sandwiching the pivot shaft. A pair of guides are disposed between the connecting wall of the bracket and the pressing surface of the axle arm, and are compressed between the connecting wall and the pressing surface when the axle arm is swung in the vertical direction. A rubber-like elastic body for absorbing and relaxing the shock transmitted from the axle arm to the frame.

Further, the rubber-like elastic body has a length extending between the left and right guides between the pressing surface and the connecting wall, and the end portion of the rubber-like elastic body on the guide side. In addition, while forming a pressing portion that is constantly in pressure contact with the pressing surface of the axle arm, between the rubber-like elastic body and the pressing surface of the axle arm, a gap from the pressing portion to the pivotal support portion of the axle arm. Is formed, and the gap is gradually enlarged as it goes from the pressing portion toward the pivotal support portion of the axle arm.

[0009]

According to this structure, when the axle arm is swung in the up-and-down direction due to the wheel climbing over a step or the like, the rubber-like elastic body is compressed between the pressing surface of the axle arm and the connecting wall of the bracket. At this time, the volume change of the rubber-like elastic body absorbs and relaxes the shock applied to the bracket from the axle arm.

Moreover, as the stroke amount of the axle arm increases, the gap becomes narrower, and the contact range between the rubber-like elastic body and the axle arm continuously expands in the vehicle width direction. Therefore, depending on the stroke amount of the axle arm. The contact area with the rubber-like elastic body is increased. In particular, the pressing portion of the rubber-like elastic body that is always in contact with the pressing surface of the axle arm is distant in the vehicle width direction from the pivot portion of the axle arm. Moment acts. Therefore, the amount of compression of the rubber-like elastic body also becomes large, and the reaction force for suppressing the swing of the axle arm becomes large accordingly.

As a result, the larger the stroke of the axle arm, the more the load applied to the rubber-like elastic body changes, so that a desired cushioning characteristic different from a simple stopper can be obtained. Therefore, not only the road surface followability of the wheel is improved, but also the foot can be sufficiently supported even in the vicinity of the maximum stroke of the axle arm, and the feeling of bottoming is eliminated.

Further, due to the existence of the above-mentioned gap, the contact area between the axle arm and the rubber-like elastic body is small at the initial stage of the stroke of the axle arm, so that the load for suppressing the swing of the axle arm is reduced and the ride comfort is improved. It will be good. At the same time, the gap gradually decreases as the swing stroke of the axle arm increases, so that the rubber-like elastic body is not abruptly compressed at one time as the axle arm swings. Therefore, the rubber-like elastic body is compressed with a certain degree of freedom corresponding to the gap, and the durability of the rubber-like elastic body is improved.

Further, since the above-mentioned gap is enlarged as it goes to the vicinity of the pivotal portion where the swinging stroke of the axle arm becomes smaller, the rubber-like elastic body is proportionately proportional to the amount of compression of the rubber-like elastic body. The capacity of the elastic body can be reduced. For this reason, there is no occurrence of a bend in a specific portion of the rubber-like elastic body, that is, a useless portion that does not contribute to cushioning, and when the axle arm is largely swung, the rubber-like elastic body is entirely removed. The cushioning function can be fully exerted by bending.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings applied to a four-wheel golf cart. The frame indicated by reference numeral 1 in the drawing includes a pair of left and right main pipes 2a and 2b extending in the front-rear direction and a plurality of cross pipes 3 connecting the main pipes 2a and 2b. A carrier 5 for mounting the caddy bag 4 is attached between the front ends of the main pipes 2a and 2b. Carrier 5
As shown in FIG. 6, it extends in the left-right direction of the frame 1 and has an elongated cage shape as a whole.

A bridge 6 which extends upward is installed between the rear portions of the main pipes 2a and 2b. Bridge 6
Left and right steering support pipes 7a, 7b extending diagonally upward toward the front are connected to the left and right ends of the steering wheel. An intermediate portion of the steering support pipes 7a and 7b is connected by a cross member 8, and a steering head pipe 9 is connected to the cross member 8. The steering head pipe 9 extends obliquely forward and downward. A steering shaft 10 is inserted through the steering head pipe 9, and a steering bar handle 11 is connected to the upper end of the steering shaft 10.

Incidentally, the steering support pipes 7a, 7b
The front end portion of is guided to the front of the upper end of the steering head pipe 9, and a support 12 that supports the upper portion of the caddy bag 4 is attached to the derived end.

A rear axle 14 extending in the vehicle width direction is supported at the rear end of the frame 1. The rear axle 14 is driven by an engine (not shown).
Left and right rear wheels 13a and 13b are attached to both end portions of the wheel 4. A step 15 is installed between the rear wheels 13a and 13b so that the driver gets on the vehicle in an upright posture. The step 15 is supported by the rear portion of the frame 1 in a state of protruding rearward from the rear axle 14.

As shown in FIG. 1, the main pipes 2a, 2
On the lower surface of the front part of b, the support stays 16 extending downward are provided.
Are connected. A bracket 17 extending in the vehicle width direction is connected between the lower ends of the support stays 16. As shown in FIG. 3 and FIG. 4, the bracket 17 of the present embodiment has an upper surface as a connecting wall that extends from the front wall 17a and the rear wall 17b facing each other and the upper ends of the front wall 17a and the rear wall 17b. It has a wall 17c integrally with it, and is formed in a generally U-shaped cross-section with the lower surface opened as a whole.

A front axle arm 18 is inserted inside the bracket 17 along the vehicle width direction. The left and right ends of the front axle arm 18 are led out to the left and right sides of the bracket 17, and a pair of left and right front axles 20 are pivotally attached to the left and right ends of the front axle arm 18 via kingpins 19. It is connected. The front axle 20 is interlocked with the steering shaft 10 via a steering mechanism (not shown), and the left and right front wheels 22a, 22 are attached to the shaft portion 21 of the front axle 20.
b is pivotally supported.

An intermediate portion of the front axle arm 18 connecting the left and right front wheels 22a, 22b is pivotally supported by the bracket 17 so as to be vertically swingable. The pivotal support structure of the front axle arm 18 will be described with reference to FIG. 3. A pivot pipe 24 extending in the front-rear direction is welded to an intermediate portion of the front axle arm 18. The pivot pipe 24 is provided so as to penetrate the front axle arm 18, and a collar 26 is inserted inside the pivot pipe 24 via a bush 25. In the collar 26, the front wall 17 a of the bracket 17 and the rear wall 1
A bolt 27 as a pivot that extends between the front axle shaft 18 and the shaft 7b is pierced by a nut 28. It is pivotally supported by the bracket 17.

The left and right ends of the bracket 17 are
As shown in FIG. 4, a synthetic resin guide 29 for positioning the front axle arm 18 in the front-rear direction is fitted. On the lower surface of the guide 29, there is formed a recess 30 into which the front axle arm 18 is fitted slidably in the vertical direction. The guide 29 has a fitting hole 3 formed by projecting projections 31 projecting from the front and rear surfaces on the front wall 17a and the rear wall 17b of the bracket 17.
By being fitted to 2, the bracket 17 is retained and retained by the bracket 17.

By the way, the front axle arm 18 has an upper surface 18a as a pressing surface facing the upper wall 17c of the bracket 17. The upper surface 18 of this front axle arm 18
Between the a and the upper wall 17c of the bracket 17, an elastic body 33 made of rubber in the shape of an elongated plate is interposed. The elastic body 33 has a length that extends between the left and right guides 29, and the elastic body 33 is fixed to the upper wall 17 c of the bracket 17. Then, the elastic body 33 is
The bolts 27 extend on both right and left sides at equal distances, and a pressing portion 34 having an increased thickness is formed at an end portion of the elastic body 33 adjacent to the guide 29. The pressing portion 34 is always in close contact with the upper surface 18a of the front axle arm 18, and applies an initial pressure to the left and right end portions of the front axle arm 18 so as to press it downward. The thickness of the elastic body 33 is continuously reduced as it goes from the pressing portion 34 toward the pivot portion of the front axle arm 18.

Therefore, the lower surface of the elastic body 33 moves toward the swing center of the front axle arm 18, and the upper surface 1 of the front axle arm 18 moves.
The inclined surface 35 is inclined in a direction away from 8a, and between the elastic body 33 and the front axle arm 18 along the vehicle width direction from the swing center of the front axle arm 18 to the pressing portion 34. The gap 36 is formed over a certain range. As shown in FIG. 2, the gap 36 is gradually enlarged as it goes from the pressing portion 34 to the pivot portion of the front axle arm 18.

The frame 1 and the left and right front wheels 22
The a, 22b and the rear wheels 13a, 13b are integrally covered from above by a cowling 38 made of synthetic resin. In such a configuration, one front wheel 22 on one side during traveling
When one end of the front axle arm 18 is pushed up by the bolt 27, for example, when a goes over a step, the pressing portion 34 of the elastic body 33 first causes the upper wall 17c of the bracket 17 and the front axle arm 18 to move.
The elastic body 33 is compressed between the upper surface 18a and the upper surface 18a, and the volume change of the elastic body 33 at this time absorbs and relaxes the impact applied to the front axle arm 18.

In this case, since there is a gap 36 between the elastic body 33 and the front axle arm 18 over a certain range along the vehicle width direction from the swing center of the front axle arm 18, FIG.
As shown in, the amount of upward stroke S of the front axle arm 18
The gap 36 is narrowed as the ratio increases. Therefore, the contact range L between the front axle arm 18 and the elastic body 33 starts to spread along the vehicle width direction, and the contact range L between the elastic body 33 and the front axle arm 18 is increased according to the stroke amount S of the front axle arm 18. Will increase.

In particular, according to the above-described structure, since the pressing portions 34 for constantly pressing the upper surface 18a of the front axle arm 18 downward are present at both ends of the elastic body 33, at the beginning of the stroke of the front axle arm 18, the front axle shaft 18a. The rattling of the arm 18 does not occur, and this posture change of the front axle arm 18 can be suppressed. Therefore, the road surface followability of the front wheels 22a and 22b is further improved, and the posture of the vehicle body is stabilized. Moreover, since the pressing portion 34 is far away from the pivotal support portion of the front axle arm 18 to the bracket 17 in the vehicle width direction, the pressing portion 34 has a large compressive load due to the swing of the front axle arm 18. Is added. Therefore, the reaction force generated in the elastic body 33 is also large, and the force for suppressing the upward swing of the front axle arm 18 is large.

Therefore, as the stroke amount S of the front axle arm 18 increases, the force for the elastic body 33 to return to the original shape changes more greatly, and a desired cushioning characteristic different from a simple stopper is obtained. be able to. Therefore, not only the road surface followability of the front wheels 22a and 22b is improved, but also the tension can be sufficiently exerted even near the maximum stroke of the front axle arm 18, the feeling of bottoming is eliminated, and the riding comfort is improved.

Further, due to the existence of the gap 36, the contact area between the front axle arm 18 and the elastic body 33 is reduced at the beginning of the stroke of the front axle arm 18, so that the swing of the front axle arm 18 is suppressed. Less power to do. Therefore, the impact transmitted from the front axle arm 18 to the frame 1 can be softly absorbed, and the riding comfort is improved.

At the same time, the gap 36 gradually decreases as the swing stroke of the front axle arm 18 increases, so that the elastic body 33 is not suddenly compressed at once when the front axle arm 18 swings. . Therefore, the elastic body 33 is compressed with a certain degree of freedom corresponding to the gap 36, and the durability of the elastic body 33 is improved.

Further, since the front axle arm 18 swings up and down about the bolt 27, the swing stroke of the front axle arm 18 is reduced in the vicinity of the pivot portion of the front axle arm 18,
As a result, the amount of compression of the rubber-like elastic body 33 also decreases. In this case, the gap 36 is gradually enlarged as it approaches the pivot portion of the front axle arm 18, and the thickness of the elastic body 33 is reduced at the portion where the compression amount of the elastic body 33 is small. In the portion where the swing stroke of the axle arm 18 is reduced, the capacity of the elastic body 33 can be reduced accordingly.

Therefore, when the front axle arm 18 is largely swung, the elastic body 33 is entirely swung without any bending of the specific portion of the elastic body 33, that is, a useless portion that does not contribute to the cushioning. Therefore, the cushioning function can be fully exerted by flexing without any waste.

The present invention is not limited to the above-described embodiment. For example, the left and right front wheels are independently supported by the left and right front axle arms, and one end of each of the left and right front axle arms is bracketed. A rubber-like elastic body may be interposed between the front axle arm and the bracket while pivotally supporting the front axle arm.

Further, the bracket is not limited to the shape in which the lower surface is opened. For example, the shape in which the upper surface is opened, and the rubber-like elastic body is interposed between the upper surface of the bottom portion of the bracket and the lower surface of the front axle arm. May be.

[0034]

According to the present invention described in detail above, when the axle arm is swung in the vertical direction, the impact applied from the axle arm to the bracket due to the volume change of the rubber-like elastic body is absorbed and relieved. In this case, the pressing portion of the rubber-like elastic body that is always in contact with the pressing surface of the axle arm is distant from the pivotal support portion of the axle arm in the vehicle width direction, and a large load due to the swing of the axle arm is placed on this pressing portion. Since it acts, the amount of compression of the rubber-like elastic body also becomes large, and the reaction force for suppressing the swing of the axle arm becomes large. Moreover, as the stroke amount of the axle arm increases, the gap is narrowed and the contact area between the rubber-like elastic body and the axle arm expands in the vehicle width direction, so that the rubber-like elastic body is added according to the stroke amount of the axle arm. The load will change greatly,
It is possible to obtain a desired cushioning characteristic different from a simple stopper. Therefore, it is of course possible to improve the road surface followability of the wheels, and it is possible to sufficiently exert the tension even near the maximum stroke of the axle arm, thereby eliminating the feeling of bottoming.

Further, due to the existence of the above-mentioned gap, the load for suppressing the swing of the axle arm is reduced at the beginning of the stroke of the axle arm, and the riding comfort is improved. With that,
Since the rubber-like elastic body does not have to be rapidly compressed at one time with the swing of the axle arm, this rubber-like elastic body is compressed with a certain degree of freedom corresponding to the above gap,
The durability of this rubber-like elastic body is improved.

Further, the above-mentioned gap is gradually enlarged as it approaches the pivotal support portion of the axle arm, and the capacity of the elastic body is correspondingly reduced in the portion where the compression amount of the rubber-like elastic body is small. There is no occurrence of a portion where no bending occurs in the specific portion, that is, a useless portion that does not contribute to cushioning. Therefore, when the axle arm is swung greatly,
There is an advantage that the rubber-like elastic body can be flexed as a whole without waste, and the cushioning function can be sufficiently exerted.

[Brief description of drawings]

FIG. 1 is a front view showing, in a partial cross section, a suspension system for a golf cart according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a partial cross section of a contact area between a rubber-like elastic body and a front axle arm.

3 is a sectional view taken along the line AA of FIG.

4 is a sectional view taken along the line BB of FIG.

FIG. 5 is a side view of the golf cart.

FIG. 6 is a plan view of a golf cart.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Frame, 17 ... Bracket, 17a ... Front wall, 17b ... Rear wall, 17c ... Connection wall (top wall) 18 ... Axle arm (front axle arm), 22 ... Wheel (front wheel), 27 ... Axis (bolt), 29 ... Guide, 33 ... Rubber-like elastic body, 34 ... Pressing part, 36 ... Gap.

Claims (1)

[Claims] 1. A metal, which is attached to the frame and has a front wall and a rear wall facing each other, and a connecting wall that extends between the front wall and the rear wall, and extends in the vehicle width direction. A bracket made of metal; and a metal axle arm that has a pressing surface facing the connection wall and is inserted through the space portion surrounded by the front wall, the rear wall, and the connection wall of the bracket along the vehicle width direction; A pivot for pivotally supporting the axle arm between the front wall and the rear wall of the bracket in a vertically swingable manner; supported on the left and right lateral ends of the bracket of the axle arm. Wheels; a pair of guides that are fixed to the bracket and that hold the axle arm so as to be able to swing in the vertical direction at positions separated by the pivot axis on both the left and right sides; and a connecting wall of the bracket and pressing of the axle arm. Face and And a rubber-like member for absorbing and relaxing a shock transmitted from the axle arm to the frame by being compressed between the connecting wall and the pressing surface when the axle arm is swung in the vertical direction. An elastic body; and the rubber-like elastic body has a length that extends between the left and right guides between the pressing surface and the connecting wall. At the end on the side, a pressing portion that constantly comes into pressure contact with the pressing surface of the axle arm is formed, and between the rubber-like elastic body and the pressing surface of the axle arm, the pressing portion from the pressing portion to the pivot arm Form a gap to the branch,
The wheel suspension device for a small vehicle, wherein the gap is gradually expanded from the pressing portion toward the pivotal support portion of the axle arm.