JPH1059094A - Small vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a smaller vehicle having a rear bumper capable of guarding its drive and brake systems without adversely affecting the rigidity of its frame. SOLUTION: Rear wheels 3 is mounted on both ends of a rear axle 10 supported between the rear portions of a pair of left and right main frames, and a follower sprocket 11 and a brake disk 15 is attached in the intermediate portion thereof. A rear bumper 31 is fitted by way of rear-bumper fitting parts 30 in the rear end of the pair of left and right main frames. The rear bumper 31 comprises a cross part 32 and loop parts 33 at both ends of the cross part 32. The loop part 33 includes an outer part 38 and an inner part 37 extending on both sides of the rear-bumper fitting part 30. The inner parts 37 guard the backsides of the follower sprocket 11 and the brake disk 15 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension-less small vehicle such as a go-kart, in which rear wheels are mounted, and more particularly to a rear bumper structure thereof.

Here, suspension-less rear wheel support refers to a type in which a rear wheel is directly supported on a body frame side without passing through a rear wheel suspension device including a swing arm and a shock absorber provided in a general passenger car or the like. Say.

[0003]

2. Description of the Related Art A small game vehicle is disclosed in Japanese Utility Model Application Laid-open No. 63-15 / 1988.
As in No. 9359, bumpers may be provided at the front and rear and the like, and the rear bumper in this example is formed in a horizontal straight line and attached to the rear end of the vehicle body frame via an elastic body.

Further, in a small vehicle of this type, when a rear cowl or the like protruding to the rear end of the vehicle body is provided, a rear bumper having a substantially arch shape in rear view is provided at the rear of the vehicle body in order to guard from a rear obstacle. There is.

In this rear bumper, a cross portion is parallel to the rear wheel axle and passes through an upper position in rear view, and at a mounting portion at both ends, as shown in FIG. Each rear end is attached via a cylindrical rubber.

The cylindrical rubber a is inserted into a main frame b having an inner diameter larger than the outer diameter of the cylindrical rubber a, and a bolt d inserted through a mounting portion c of a rear bumper and a shaft hole of the cylindrical rubber a.
Is fastened to a nut e in the main frame b, and the cylindrical rubber a is compressed in the axial direction as shown by the imaginary line and bulged in the radial direction, so that the main frame b and the rear bumper f
Are connected via a cylindrical rubber a. One such conventional example is Japanese Utility Model Publication No. 60-1651.

[0007] Japanese Utility Model Publication No. 63-1634 and 63
Japanese Patent No. 39151 discloses a structure in which an automobile bumper is mounted on a vehicle body side via a cylindrical bush having rubber interposed between an inner and an outer cylinder. These cylindrical bushes are provided on a plate portion of a bump pasty. Into the hole provided.

[0008]

By the way, the rear wheels of the go-kart are often supported on the main frame without suspension. In this case, the rigidity of the main frame is adjusted to replace the rear wheel suspension device. I have.

Therefore, it is advantageous that the right and left mounting portions with respect to the main frame cannot be linearly connected so that the rear bumper does not affect the rigidity of the main frame by mounting the rear bumper, so that the rear bumper has a substantially arch shape. It is necessary to attach to the body frame via an elastic body such as a cylindrical rubber.

On the other hand, when a drive system component and a brake system component are provided on the rear wheel axle, it is desired that these components be guarded by a rear bumper. However, the above-described substantially arched rear bumper cannot guard these components.

Conversely, if the right and left mounting portions of the rear bumper to the main frame are linearly connected to guard them, there is a problem that the rigidity of the main frame is affected.

Further, according to the cylindrical rubber mounting structure shown in FIG. 5, the cylindrical rubber a undergoes compressive deformation in the axial direction in accordance with the degree of tightening of the bolt d. As a result, the rigidity of the rear bumper mounting portion c tends to vary, and as a result, there is a problem that it becomes difficult to control the tightening torque at the time of fastening the bolt.

Moreover, if the bolted portion of the cylindrical rubber a becomes fatigued due to long-term use, the tightening torque is lost,
There is a possibility that the cylindrical rubber a may fall off the main frame b together with the bolt d and the like.

Incidentally, Japanese Utility Model Publication No. 63-1634 and 63
No. 39151 relates to a structure in which a vehicle bumper is mounted on a vehicle body via a cylindrical bush, and is mounted on the same axis as the rear end of the main frame and into a mounting portion of a cylindrical rear bumper. Since the elastic body is not interposed, the object is different from that of the present invention.

[0015]

Means for Solving the Problems To solve the above problems, the invention according to claim 1 comprises a pair of left and right main frames provided in a front-rear direction of a vehicle body, and a pair of left and right front wheels provided at a front portion thereof. A small vehicle having a pair of left and right rear wheels attached to both ends of a rear wheel axle supported across the rear portions of the left and right main frames, and a rear bumper attached between the rear ends of the main frames via elastic members. (Hereinafter referred to as a premise structure), the rear bumper includes a cross portion parallel to the rear wheel axle and extending in the vehicle width direction at an upper position in rear view, and a loop portion formed below both left and right ends of the cross portion. The unit has a mounting portion for mounting to the main frame, and has an outer portion and an inner portion with the mounting portion interposed therebetween, and the inner portion has a drive system component and a brake system component provided on the rear wheel axle. Characterized in that located towards.

According to a second aspect of the present invention, in the small-sized vehicle having the above-mentioned structure, the elastic member interposed between the main frame and the mounting portion of the rear bumper includes an inner and outer cylinder and an elastic body filled therebetween. The mounting portion of the rear bumper with respect to the main frame has a cylindrical shape disposed on the same axis as the rear end of the main frame, and the outer cylinder side of the cylindrical bush is press-fitted into the mounting portion of the rear bumper. The inner cylinder is fastened to the rear end of the main frame.

[0017]

The rear bumper is composed of a cross portion and a loop portion formed at both ends thereof. An outer portion and an inner portion are provided in the loop portion with the mounting portion interposed therebetween, and the outer portion of the rear wheel is formed by the outer portion. Guarding the rear, guarding the rear of the drive system components and brake system components on the rear wheel axle inside.

Thus, the rear bumper can guard the drive system components and the brake system components inside the loop portion, and can connect the left and right loop portions to the same cross portion as before without connecting the left and right mounting portions linearly. The connection is established through the connection, so that the rigidity of the main frame is not affected.

When the outer cylinder of the cylinder bush is press-fitted into the cylindrical mounting portion and the inner cylinder is fastened to the rear end of the main frame,
Since the fastening of the tubular bush has no effect on the elastic body, the rigidity of the mounting portion of the rear bumper with respect to the main frame is determined only by the elastic modulus of the elastic body.

Therefore, unlike the related art, it is not necessary to manage the tightening torque of the bolt, which is difficult, and the mounting of the rear bumper to the main frame is facilitated, and the work efficiency is improved. Moreover, since the elastic body is not directly tightened at the fastening portion, there is no possibility that the bolt will fall off even after long-term use.

[0021]

FIG. 1 is a rear view of a go-kart, and FIG.
Is a side view thereof, and FIG. 3 is a plan view thereof. The go-kart is provided with a main frame 1 extending in a left-right pair in the front-rear direction of the vehicle body, and a front wheel 2 and a rear wheel 3 are provided on each of the left and right sides.
Is supported.

The main frame 1 has a substantially ladder-type structure, a seat 4 is provided at the center, and a fuel tank 5 and a handle 6 are provided in front of the seat 4.

An engine 7 is provided on the right side of the seat 4, and its output is transmitted from a main sprocket 8 via a chain 9 to a slave sprocket 11 on a rear wheel axle 10.

Rear wheel axle 10 with rear wheels 3 mounted on both ends
Both ends are supported by axle stays 13 and 14 which are provided to protrude above the rear ends of the left and right main frames 1 to support suspension-less rear wheels.

In the vicinity of an axle stay 14 provided on the left side of the rear axle 10, a brake disk 15 is provided so as to be able to rotate integrally with the rear axle 10.

A brake caliper 16 for braking the brake disk 15 is supported by the axle stay 14, and is operated by a brake pedal (not shown). A parking brake operated by a lever 18 via a cable 17 is also provided.

A cross pipe 20 is provided between the front ends of the left and right main frames 1, and a front wheel 2 is supported on both left and right ends thereof.

At the center of the left and right main frames 1, side box stays 21 extending laterally are provided in a wing shape.

In the vicinity of the seat 4, a cross pipe 22 is provided on the front side between the left and right main frames 1, and a cross pipe 23 is provided on the rear side to connect diagonally. Left and right members 22a and 22b connecting the front and back, and a cross member 22c connecting the left and right members 22a and 22b are provided, and serve as a support portion of the seat 4.

The vehicle body cover that covers the vehicle body frame includes a front fairing 24 and a front panel 2 from the front.
5, a side box 26, an engine cover 27, and a rear cowl 28. Among them, the engine cover 27
Are integrally formed as a part of the rear cowl 28.

At the rear ends of the left and right main frames 1, a rear bumper 31 is mounted via a rear bumper mounting portion 30. The mounting part 30 of the rear bumper is the main frame 1
Is a cylindrical member disposed on the same axis as the rear end portion, and is integrated with the rear bumper 31 in advance.

As is apparent from FIG. 1, the rear bumper 31 has a cross portion 32 extending parallel to the rear wheel axle 10 and extending upward in the vehicle width direction in a rear view, and loop portions 33 formed at both ends thereof. And the whole is formed from one continuous metal pipe.

The cross portion 32 is located at a position substantially coincident with a portion between the slave sprocket 11 and the brake disc 15 of the rear wheel axle 10 and extends from both ends thereof to the outer surface of the rear wheel 3 substantially. 34 are formed.

In the rear view of the rear bumper 31 shown in FIG. 1, the loop portion 33 is a substantially ring-shaped portion including an extension portion 34, an outer upper and lower portion 35, a lower side portion 36, and an inner portion 37.

The outer upper / lower portion 35 bends downward from the end of the extension portion 34 and extends downward substantially along the outer surface of the rear wheel 3.
It turns toward the center of the vehicle body at a position lower than the rear wheel axle 10 and continues to the lower side portion 36.

The lower side portion 36 has a slight inclination with respect to the rear wheel axle 10 so as to become lower toward the inside of the vehicle body, and its inner side end is connected to the mounting portion 30 of the rear bumper.

The inner portion 37 extends on the extension of the lower side portion 36 from the mounting portion 30 of the rear bumper, bends again upward at the lowermost portion, extends upward diagonally outward, and has the cross portion 32 and the extension portion 34 at the upper end portion. Connected to the boundary of

The lowermost part of the inner part 37 is the slave sprocket 1
1 and the lowermost position of each of the brake disks 15.

The inner part 3 of the loop part 33 on the right side of the vehicle body
7 is curved so as to partially overlap behind the slave sprocket 11 in a rear view, and is curved so as to overlap behind the brake disc 15 on the same left side.

The extension portion 34, the outer upper and lower portions 35, and the lower side portion 36 form an outer portion 38 of the loop portion 33, and this portion is located substantially outside the mounting portion 30 of the rear bumper.

On the other hand, the inner portion 37 is
3, the inner part of which is the mounting part 30 of the rear bumper.
It is located almost inside.

FIG. 4 is a sectional view showing details of the mounting structure of the mounting portion 30 of the rear bumper. As you can see in this figure,
Inside the rear bumper mounting portion 30, the outer cylinder 40 is
2 and a cylindrical bush 43 provided with an elastic body 41 of rubber or synthetic resin integrated between the inner and outer cylinders.

The cylindrical bush 43 abuts one end of the inner cylinder 42 with a washer 44 and the other end with the rear end of the main frame 1, and attaches a bolt 45 passed through the inner cylinder 42 and the washer 44 to the main frame. By fastening to the nut 46 welded in a state where it has been fitted to the rear end of the
It is attached to the rear end of the main frame 1.

Next, the operation of the present embodiment will be described. The rear bumper 31 guards the rear part of the vehicle body from contact with a rear obstacle. In particular, the cross portion 32 guards a portion of the rear cowl 28 projecting rearward of the vehicle body, and the outer portion 38 of the loop portion 33 guards rearward of the rear wheel 3.

Further, since the inner portions 37 are provided on the left and right,
As a result, the drive sprocket 11 and the brake disc 15 and the brake caliper 16 which are components of the brake system on the rear wheel axle 10 can be simultaneously guarded.

In addition, the guards do not need to be linearly connected between the mounting portions 30 of the left and right rear bumpers, and separate the left and right loop portions 33 from each other. Since the connection is made by a single cross portion 32 which is farther apart than above, the rigidity of the main frame 1 is not affected.

Further, a cylindrical bush 43 is used for the mounting portion 30 of the rear bumper, and the inner cylinder 42 is tightened between the washer 44 and the nut 46 by the bolt 45.
By the fastening of 5, the elasticity of the elastic body 41 does not change.

Since the elastic member 41 is not directly tightened by the bolt 45, the elastic member 41 may be used for a long time.
As a result, a situation in which the elastic body falls off the main frame does not occur.

Therefore, the rigidity of the mounting portion between the mounting portion 30 of the rear bumper and the main frame 1 is the elastic body 41.
Is determined only by the modulus of elasticity, and is not affected by the tightening of the bolt 45, so that the tightening torque can be easily controlled, the efficiency of the rear bumper mounting operation can be significantly improved, and the durability can be improved.

The present invention is not limited to the above-described embodiment, but can be modified in various ways. For example, the cylindrical bush may be of a baking type or a press-fit type of an elastic body. In the invention according to the first aspect, the elastic member may be a known elastic means such as a metal spring instead of the cylindrical bush.

[Brief description of the drawings]

[Figure 1] Go-kart rear view

FIG. 2 is a plan view thereof.

FIG. 3 is a side view thereof.

FIG. 4 is an enlarged sectional view of a mounting portion of a rear bumper.

FIG. 5 is a diagram corresponding to FIG. 4 in a conventional example.

[Explanation of symbols]

1: Main frame, 3: Rear wheel, 7: Engine, 10:
Rear wheel axle, 11: slave sprocket (drive system part), 1
5: brake disc (brake system parts), 30: rear bumper mounting part, 31: rear bumper, 37: inner part, 3
8: Outer part, 43: Cylindrical bush

Claims (2)

[Claims] 1. A pair of left and right main frames provided in the front-rear direction of a vehicle body, a pair of left and right front wheels provided at front portions thereof, and both ends of a rear wheel axle supported across a rear portion of the left and right main frames. In a small vehicle having a pair of left and right rear wheels attached to the rear frame, and a rear bumper attached between the rear ends of the main frame via an elastic member, the rear bumper is positioned parallel to the rear wheel axle and at an upper position in rear view in the vehicle width direction. And a loop portion formed below the left and right ends of the cross portion. The loop portion has a mounting portion for mounting to the main frame, and has an inner portion and an outer portion sandwiching the mounting portion. A compact vehicle comprising a vehicle body and an inner part located behind each of a drive system component and a brake system component provided on a rear wheel axle. 2. A pair of left and right main frames provided in the front-rear direction of the vehicle body, a pair of left and right front wheels provided at a front portion thereof, and both ends of a rear wheel axle supported across a rear portion of the left and right main frames. In a small vehicle having a pair of left and right rear wheels mounted without a suspension and a rear bumper mounted between rear ends of a main frame via an elastic member, the elastic member is filled between the inner and outer cylinders. A cylindrical bush made of an elastic body, and a mounting portion of the rear bumper with respect to the main frame has a cylindrical shape arranged on the same axis as the rear end of the main frame. A compact vehicle characterized by press-fitting the cylinder side and fastening the inner cylinder to the rear end of the main frame.