JP2000039043A - Leaf spring bush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve both the steering stability and riding comfort of a vehicle by forming a bush to be fixed between an arm eye formed on both ends of a leaf spring and a mounting plate from a first rubber elastic body for mainly absorbing the axially right-angled vibration and a second rubber elastic body for mainly absorbing the torsional directional vibration. SOLUTION: A bush to be interposed between an arm eye 32 integrally formed on both ends of a leaf spring and a metal pin 50 supported by a pair of mounting plates 41 fixed to the body side is formed of first and second rubber elastic bodies 10, 20. The first rubber elastic body 10 is formed into a cylinder for mainly absorbing the axially right-angled vibration with a hard spring characteristic, and the second rubber elastic body 20 arranged on both ends of the elastic body 10 is formed into a cylinder for mainly absorbing the torsional directional vibration with a soft spring characteristic. The second rubber elastic body 20 is formed so as to have an annular flange part 22 protruded on the circumference on one end side of a cylindrical part 21, and the flange part 22 is interposed between it and the mounting plate 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leaf spring bush for a vehicle.

[0002]

2. Description of the Related Art A leaf spring 30 for a vehicle is shown in FIG.
As shown in the figure, has an axle mounting portion 31 at the center in the longitudinal direction,
Arm eyes 3 with leaf springs rolled into a cylindrical shape at both ends in the longitudinal direction
2, 33 are provided. As shown in FIG. 7, for example, a pair of leaf spring bushes to be inserted into the arm eyes 32 and 33 includes a pair of a cylindrical portion 1a and an annular flange portion 1b protruding from the outer periphery at one end side. A rubber elastic body 1 is known, and the outer diameter of the cylindrical portion 1a of the rubber elastic body 1 is set to the center hole 32 of the arm eyes 32, 33.
a, 33a. Each of the pair of rubber elastic bodies 1 has a central portion 32a, 33 in the cylindrical portion 1a.
a is attached to the arm eyes 32 and 33 by inserting the arm from both sides in the axial direction. This arm eye 32
As shown in FIGS. 5 and 6, a pair of rubber elastic bodies 1 attached to the vehicle body 40 are mounted substantially vertically on the vehicle body 40 and face each other, and have a pair of mounting plates having mounting holes 41a and 41b at the opposing positions. 41. Then, as shown in FIG. 6, the mounting holes 41a and 41b and the center hole 1c of the rubber elastic body 1 are formed.
A pair of rubber elastic bodies 1 is formed by inserting a metal pin 50 through the metal pin 50, engaging one end side head 51 of the metal pin 50 with one mounting plate 41, and screwing a nut 53 to the other end side screw portion 52. It is mounted between the arm eye 32 and a pair of mounting plates 41. Further, by tightening the nut 53, the pair of rubber elastic bodies 1 are fixed between the arm eye 32 and the pair of mounting plates 41 in a state where the two elastic plates 1 are pre-compressed in the axial direction. By applying the pre-compression, the play between the rubber elastic body 1 and the arm eye 32 and the mounting plate 41 can be absorbed, and the axial vibration isolation characteristics can be improved. Further, the rubber elastic body 1 attached to the arm eye 33 is also fixed in the same manner as above by being sandwiched between a pair of attachment plates 43 attached to the attachment portion 42 of the vehicle body 40.

This leaf spring bush is shown in FIG.
As shown in FIG. 3, the vibration generated on the wheel A side is caused by the axle B and the vehicle body 4.
The vibration is transmitted through the leaf spring 30 connecting between the 0 and 0 directions, but the vibration in the direction perpendicular to the axis is mainly
, And the torsional vibration is mainly absorbed by the flange portion 1b. Therefore, the spring characteristics of the leaf spring bush include the cylindrical portion 1a.
By setting the spring characteristics hard, the vibration in the direction perpendicular to the axis can be absorbed, the stability of the operation of the vehicle can be ensured, the durability can be ensured, and the spring characteristics of the flange portion 1b are set soft. Thus, the ride comfort can be improved by absorbing the vibration in the torsional direction.

[0004]

However, the leaf spring bush described above has a cylindrical portion 1a and a flange portion 1b.
Is composed of a single rubber elastic body, the spring characteristics of the cylindrical portion 1a and the flange portion 1b cannot be changed to hardnesses corresponding to their respective functions, so that steering stability and ride comfort are not improved. It was difficult to achieve the improvement at the same time.

SUMMARY OF THE INVENTION The present invention is directed to solving the above-mentioned problems, and provides a bush for a leaf spring capable of simultaneously achieving steering stability and ride comfort in a vehicle without impairing durability. The purpose is to:

[0006]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, the structural feature of the invention described in claim 1 is a leaf spring bush.
It is inserted into the inside of the arm eye integrally provided at both ends of the leaf spring fixed to the axle side, the outer diameter is almost the same as the inside diameter of the arm eye, and the axial length is slightly shorter than the axial length of the arm eye, It has a cylindrical first rubber elastic body having a hard spring characteristic, a cylindrical part having an inner diameter substantially the same as that of the first rubber elastic body, and an annular flange part protruding from an outer periphery at one end side of the cylindrical part. Then, the cylindrical part is inserted into both ends of the arm eye,
A pair of second rubber elastic bodies having soft spring characteristics, and being fixed substantially vertically to the vehicle body directly or via another member, facing each other, and having a pair of mounting plates having mounting holes at opposing positions. A pair of second rubber elastic bodies inserted between the first and second rubber elastic bodies are sandwiched, and a metal pin is inserted through the mounting hole and the center holes of the first and second rubber elastic bodies. The first and second rubber elastic bodies are axially pre-compressed by engaging the nut with the other mounting plate by screwing the nut to the other end side screw portion, and the arm eye and the pair of It is to be fixed between the mounting plates.

According to the first aspect of the present invention, the bush fixed between the arm eye and the mounting plate includes a first rubber elastic body that mainly absorbs vibration in a direction perpendicular to the axis, and a torsional vibration. Is provided separately from the second rubber elastic body, the spring characteristic of the first rubber elastic body is set to be hard, and the spring characteristic of the second rubber elastic body is set to be soft. As a result, according to the first aspect of the present invention, the first
The durability of the bush can be ensured by the rubber elastic body, the steering stability in the vehicle can be achieved, and the riding comfort of the vehicle can be improved by the second rubber elastic body.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a main part of a state in which a leaf spring bush according to the present embodiment is mounted between a vehicle body and a leaf spring. It is shown by a partial sectional view. This bush for leaf spring is shown in FIG.
As shown in FIG. 3, a first rubber elastic body 10 having a hard spring characteristic and a pair of second rubber elastic bodies 20 having a soft spring characteristic are provided. The first rubber elastic body 10
The outer diameter is substantially the same as the inner diameter of the center holes 32a, 33a of the arm eyes 32, 33, the inner diameter of the center hole 11 is substantially the same as the shaft diameter of a metal pin 50 described later, and the axial length is the arm eye 3
2, 33 are slightly shorter than the axial length.

The second rubber elastic body 20 is formed of the first rubber elastic body 1.
0 and an annular flange 22 protruding from the outer periphery of one end of the cylindrical portion 21. The outer diameter of the flange 22 is equal to that of the arm eyes 32, 33. Slightly larger than the inner diameter of the center holes 32a, 33a,
The axial length of the cylindrical portion 21 excluding the flange portion 22 is 2 mm
It is set to ５5 mm. When the axial length of the cylindrical portion 21 is smaller than 2 mm, the second rubber elastic body 20 is inserted into both ends of the arm eyes 32, 33, and then the arm eyes 32, 33 are inserted.
33, and the workability of assembling is reduced. Further, when the axial length of the cylindrical portion 21 is 5 mm or more, the ratio of the rubber portion having a soft spring characteristic to the rubber elastic portion absorbing the vibration in the direction perpendicular to the axis increases, so that the vibration damping function is reduced. At the same time, durability is impaired.

[0010] When assembling the leaf spring bush to a vehicle, first, the first rubber elastic body 10 is
It is inserted inside the arm eyes 32 and 33. Thereafter, a pair of second rubber elastic bodies 20 are inserted into both ends of the arm eyes 32 and 33 from the other end side of the cylindrical portion 21.

As shown in FIG. 1, the two rubber elastic bodies 10 and 20 inserted into the arm eye 32 are substantially vertically attached to the vehicle body 40 and face each other.
A pair of mounting plates 41 having a pair 41b are sandwiched from both sides in the axial direction. Next, the head 51 is inserted into the mounting holes 41a and 41b and the center holes 11 and 23 of the rubber elastic bodies 10 and 20 at one end.
And a metal pin 50 having a small-diameter screw portion 52 at the other end thereof is inserted, the head 51 is engaged with one of the mounting plates 41, and a nut 53 is screwed onto the screw portion 52 to form the other mounting plate. By being engaged with 41, both rubber elastic bodies 10 and 20 are attached between arm eye 32 and a pair of attachment plates 41. Further, by tightening the nut 53, the two rubber elastic bodies 10 and 20 are brought into contact with the arm eye 3 in a state where the two rubber elastic bodies 10 and 20 are precompressed in the axial direction by the two mounting plates 41.
It is fixed between 2 and a pair of mounting plates 41. By applying the pre-compression to the rubber elastic bodies 10 and 20, the play between the rubber elastic bodies 10 and 20 and the arm eye 32 and the mounting plate 41 can be absorbed, and the axial vibration isolation characteristics can be improved. The rubber elastic bodies 10 and 20 inserted into the arm eye 33 are also fixed by a pair of mounting plates 43 mounted on the mounting portion 42 of the vehicle body 40 in the same manner as described above.

Vibration from the wheel A is transmitted to the leaf spring bush through the leaf spring 30 connecting the axle B and the vehicle body 40. Vibration in the direction perpendicular to the axis is mainly hard. The first rubber elastic body 10 having the spring characteristic is effectively absorbed, and the vibration in the torsional direction is effectively prevented by the second rubber elastic body 20 having the soft spring characteristic provided separately from the first rubber elastic body 10. Absorbed. Therefore, the durability of the bush is ensured and the steering stability of the vehicle is achieved by the first rubber elastic body 10. Further, the second rubber elastic body 20 achieves improvement in the riding comfort of the vehicle.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a main part of a state in which a bush for a leaf spring according to an embodiment of the present invention is mounted between a vehicle body and a leaf spring.

FIG. 2 is a first view of the leaf spring bush;
It is sectional drawing which shows a rubber elastic body.

FIG. 3 shows a second embodiment of the leaf spring bush.
It is sectional drawing which shows a rubber elastic body.

FIG. 4 is a front view of a leaf spring.

FIG. 5 is a front view showing a relationship between a leaf spring and a vehicle body and an axle.

FIG. 6 shows a conventional leaf spring bush.
It is a fragmentary sectional view showing the important section of the attachment state between the body and the leaf spring.

FIG. 7 is a sectional view showing a rubber elastic body constituting the leaf spring bush.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... 1st rubber elastic body, 11 ... center hole, 20 ... 2nd rubber elastic body, 21 ... cylindrical part, 22 ... flange part, 23 ... center hole, 30 ... leaf spring, 31 ... axle mounting part, 3
2, 33: arm eye, 32a, 33a: center hole, 40
... Vehicle, 41, 43 ... Mounting plate, 41a, 41b ... Mounting hole, 42 ... Mounting part, 50 ... Metal pin, 51 ... Head, 52
... Screw part, 53 ... Nut, A ... Wheel, B ... Axle.

Claims (1)

[Claims] 1. An arm eye which is integrally provided at both ends of a leaf spring fixed to an axle side, has an outer diameter substantially equal to an inner diameter of the arm eye, and has an axial length in an axial direction of the arm eye. A first rubber elastic body which is slightly shorter than the length and has a hard spring characteristic, a cylindrical part having an inner and an outer diameter substantially equal to the first rubber elastic body, and protrudingly provided on an outer periphery at one end side of the cylindrical part; A pair of second rubber elastic bodies having a soft spring characteristic, wherein the cylindrical portion is inserted into both ends of the arm eye. The second rubber elastic body has a soft spring characteristic. The pair of second rubber elastic bodies inserted into the arm eye are interposed between a pair of mounting plates which are fixed substantially vertically through each other and have mounting holes at opposing positions, and the mounting hole and the first rubber are sandwiched. And inserting a metal pin through the center hole of the second rubber elastic body, The first and second rubber elastic bodies are formed by engaging the one end side head with one mounting plate and screwing a nut to the other end side screw portion to engage with the other mounting plate. A bush for a leaf spring, which is fixed between the arm eye and a pair of mounting plates in a state where pre-compression in a direction is applied.