JP2000002278A - Cylindrical vibration isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical vibration isolation device which can prevent occurrence of damage of a rubber elastic body between ends of inner and outer cylindrical metal fittings, and shows high durability. SOLUTION: An inner cylindrical metal fitting 10 is composed of a cylindrical main body 11, a widened portion 12 in a diameter coaxially at its one end, and a tapered portion 13 continued to the inner end, conically decreased in diameter and lead to the main body in an integral manner. An outer cylindrical metal fitting 20 is arranged coaxially on an outer peripheral side of the inner cylindrical metal fitting, within an axial range of the inner cylindrical metal fitting. A rubber elastic body 30 is vucanized and molded across the inner and outer cylindrical metal fittings for connecting them. The rubber elastic body is cutout along a circumferential direction and circularly formed on the widened diametrical portion side end, before throttle processing of the outer cylindrical metal fittings. Its axial sectional form is rectangularly formed. Its axial end is arranged on an end of the axially center side of the tapered portion, or axially center side thereof. An expanded portion formed by the throttle processing is not projected outward from the end of the outer cylindrical metal fitting. An amount of the rubber is increased at the opposite side end of the elastic body in an axial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tubular vibration isolator used for a vehicle or the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, for example, as shown in FIG. 3, a cylindrical vibration isolator is provided with an enlarged diameter portion 3 coaxially enlarged at one end of a cylindrical main body portion 2. An inner cylindrical metal fitting 1 having a conical reduced diameter following the diameter part 3 and provided with an inclined part 4 following the main body part 2, coaxially disposed on the outer peripheral side of the inner cylindrical metal fitting 1,
Vulcanization between the cylindrical outer tube 5 and the cylindrical outer tube 5 whose axial length is shorter than the inner tube 1 and whose end on the enlarged diameter portion 3 side is located in the inclined portion 4. It has a cylindrical rubber elastic body 6 which is formed and is substantially symmetrical at both axial ends for connecting the both. Further, in this cylindrical vibration isolator, after the rubber elastic body 6 is vulcanized, the outer cylindrical metal fitting 5 is subjected to drawing in order to stabilize its spring characteristics. The portion will bulge outward from the position shown in FIG. In this cylindrical vibration isolator, as shown in FIG. 4, the inner cylindrical fitting 1 is inserted and fixed to the outer periphery of a cantilever support portion 7a protruding from an axle 7 for fixing wheels, and the outer cylindrical fitting 5 is connected to a shock absorber 8 Is inserted and fixed to the collar portion 8a, and the vibration from the wheels is attenuated and transmitted to the shock absorber 8.

[0003]

By the way, when the above cylindrical vibration isolator is mounted on a vehicle, the inner and outer cylindrical metal fittings 1 and 2 are used.
The outer tube fitting 5 is not twisted and is kept coaxial. However, when the vehicle is driven, a twist input is generated to generate a large 3-5 ° twist and a large load is applied. In this case, the other end of the main body 2 of the inner cylinder 1 and the end of the outer cylinder 5 are spaced apart from each other, and the compression ratio of the rubber elastic body is not strict. Since the distance between the inclined portion 4 and the end of the outer cylinder 5 is short, as shown in FIG. 4, the compression ratio of the rubber elastic body 6 therebetween is high, so that the end of the outer cylinder 5 is increased. Is the bulging portion 6a at the end of the rubber elastic body.
And the rubber elastic body 6 may be damaged by cracks growing from the portion. On the other hand, it is conceivable to reduce the amount of rubber in the rubber elastic body 6. However, since this cylindrical vibration isolator is a component that is exposed to a large load and has severe durability, the rubber amount is appropriately maintained. It is not preferable to reduce the amount of rubber because the durability is impaired. An object of the present invention is to solve the above-described problems, and an object of the present invention is to provide a cylindrical vibration damping device that can prevent damage to a rubber elastic body between ends of inner and outer cylindrical fittings and has excellent durability. And

[0004]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, the structural feature of the invention according to the first aspect is that the diameter of the cylindrical body is increased coaxially at one end side. And an inclined portion that is conically reduced in diameter from the inner end of the enlarged diameter portion and is integrally provided with the main body portion, and is inserted and fixed to the outer periphery of a cantilever support portion provided in the vehicle. An inner cylindrical metal fitting, a cylindrical outer cylindrical metal fitting that is coaxially arranged on the outer peripheral side of the inner cylindrical metal fitting, has a shorter axial length than the inner cylindrical metal fitting, and is attached to a mating member provided in the vehicle; A tubular rubber elastic body which is vulcanized and formed between the inner tubular fitting and the outer tubular fitting and connects the two, and wherein the outer tubular fitting is subjected to drawing processing, wherein the outer tubular fitting is Before drawing, the end of the rubber elastic body on the enlarged diameter side is cut out along the circumferential direction so that the axial cross-sectional shape is substantially rectangular. And an annular end portion provided on the end of the inclined portion on the axial center side or at a distance from the end to the axial center side, and a rubber elastic body. This is because the amount of rubber at the end opposite to the axial direction has been increased.

[0005] In the invention according to claim 1 configured as described above, before the drawing process of the outer cylindrical metal fitting, the end portion of the rubber elastic body on the side of the enlarged diameter portion is provided with a straight portion having a rectangular cross section in the axial direction. Even if the rubber elastic body is swelled outward in the axial direction by the drawing process of the outer cylinder, the swelling portion does not protrude outward from the end of the outer cylinder. Therefore, even if a large twist of 3 to 5 mm occurs due to a twist input between the inner and outer cylinders during the operation of the vehicle, the end of the outer cylinder is bulged to the end on the enlarged diameter side. The rubber elastic body does not bite into the rubber elastic body, and as a result, the rubber elastic body is not damaged. In addition, although the amount of rubber is reduced on the side of the bulge, the amount of rubber on the opposite end in the axial direction is increased,
A necessary rubber amount is secured in the entire rubber elastic body. As a result, the durability of the rubber elastic body is maintained.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a cylindrical vibration isolator mounted between an acruz for fixing a vehicle wheel and a shock absorber according to the embodiment. FIG. 2 is a cross-sectional view of the device in a state before drawing of an outer cylinder. The cylindrical vibration isolator
An inner cylinder fitting 10, an outer cylinder fitting 20 coaxially arranged on the outer peripheral side of the inner cylinder fitting 10, and provided by vulcanization molding between the inner cylinder fitting 10 and the outer cylinder fitting 20 to connect the two fittings. And a substantially cylindrical rubber elastic body 30.

[0007] The inner tube fitting 10 includes a main body 1 made of a metal pipe.
In a portion of a predetermined length in the axial direction at one end (left end in the drawing), an enlarged diameter portion 12 extending from the one end and coaxially enlarged, and an axial direction following the enlarged diameter portion 12 are provided. An inclined portion 13 which is conically reduced in diameter toward the center and continues to the main body portion 11 is provided. The enlarged diameter portion 12 and the inclined portion 13 are integrally formed by subjecting the main body portion 11 to a pipe expansion process.

The outer cylinder fitting 20 is a thin cylindrical metal fitting, and has an axial length smaller than that of the inner cylinder fitting 10.
It is arranged coaxially and axially centered on the outer peripheral side of the inner cylinder fitting 10. At this time, one end side of the outer cylinder 20 is located between the inclined portions 13 of the inner cylinder 10.

The rubber elastic body 30 is provided at one axial end thereof with an annular curving portion 31 which is cut out along the circumferential direction and dented in the axial direction, and has a substantially rectangular cross section in the axial direction. I have. The straightening portion 31 is formed by a slanted portion 13 extending from the boundary between the enlarged diameter portion 12 and the slanted portion 13 of the inner cylinder fitting 10 toward the center in the axial direction.
And a vertical portion 31b extending from the inner end of the horizontal portion 31a in a direction perpendicular to the axis. Vertical part 31b
And the boundary between the horizontal portion 31a and the vertical portion 31b and the outer tube fitting 20
Has an R-shaped boundary with the inner peripheral surface.

The other end of the rubber elastic body 30 in the axial direction is
A position near the other end of the inner cylindrical member 10 is connected to a position near the other end of the outer cylindrical member 20, and a slightly dented portion 32 is formed so as to have a concave cross-sectional shape. Has a larger amount of rubber than conventional ones. Therefore, the rubber elastic body 30 has a reduced amount of rubber by providing the bulging portion 31 at one end, but by increasing the amount of rubber at the other end, the amount of rubber contributing to its durability is reduced as a whole. Designed not to reduce.

As described above, before the outer cylindrical metal member 20 is drawn, the rubber elastic body 30 is provided with the straight portion 31 having a rectangular cross-sectional shape at one end thereof.
When the outer cylinder 20 is drawn after vulcanization molding of
Although one end of the rubber elastic body 30 swells outward in the axial direction, the swelling portion 30a does not protrude outward from the end of the outer cylinder 20 as shown in FIG.

[0012] As shown in FIG.
The inner cylinder fitting 10 is inserted around the outer periphery of a cantilever support portion 41 protruding from an axle 40 for fixing wheels of a vehicle, and a nut 43 is screwed into a fixing portion 41 a at a distal end via a spacer 42, so that the inner cylinder fitting 10 is screwed. It is fixed to the holding support portion 41. Also,
The outer tube fitting 20 is provided with the collar 5 of the shock absorber 50.
1 and fixed.

In the embodiment configured as described above, the bulging portion 30a of the rubber elastic body 30 on the enlarged diameter portion 12 side does not protrude outward from the end of the outer cylindrical fitting 20, so that the vehicle is During operation, a twisting input and a large load are applied between the inner and outer cylindrical fittings 10 and 20 to thereby reduce the distance between the two fittings.
Even if a large twist of up to 5 ° occurs, the end of the outer cylindrical member 20 does not bite into the bulging portion 30a of the rubber elastic body 30, so that the rubber elastic body 30 is not damaged. Further, although the amount of rubber is reduced on the side of the bulging portion 31, the amount of rubber on the end portion on the opposite side in the axial direction is increased, so that the required amount of rubber is secured by the entire rubber elastic body 30. As a result, the durability of the rubber elastic body 30 is maintained.

In the above embodiment, the case where the cylindrical vibration isolator is mounted between the axle for fixing the wheels of the vehicle and the shock absorber is described. However, the present invention is not limited to this case, and may be applied to other similar uses. It is possible to use.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a cylindrical vibration isolator according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing a state where the cylindrical vibration isolator is attached to a vehicle body.

FIG. 3 is a cross-sectional view showing a conventional cylindrical vibration isolator.

FIG. 4 is a partial cross-sectional view showing a state where a conventional cylindrical vibration isolator is attached to a vehicle body.

[Explanation of symbols]

Reference numeral 10: inner cylinder fitting, 11: body part, 12: enlarged diameter part, 13 ...
Inclined part, 20 ... outer cylinder fitting, 30 ... rubber elastic body, 30a ...
Swelling part, 31 ... Curved part, 31a ... Horizontal part, 31b ...
Vertical part, 32: Curving part, 41: Cantilever support part, 50: Shock absorber.

Claims (1)

[Claims] 1. An enlarged diameter portion which is coaxially enlarged at one end side of a cylindrical main body portion, and which is conically reduced in diameter from an inner end of the enlarged diameter portion, and an inclined portion which follows the main body portion. Is provided integrally,
An inner cylinder fitting fixedly attached to the outer periphery of the cantilever support provided on the vehicle, and coaxially disposed on the outer periphery of the inner cylinder, and having an axial length shorter than that of the inner cylinder. A cylindrical outer cylindrical fitting attached to a mating member provided in a vehicle; and a cylindrical rubber elastic body formed by vulcanization between the inner cylindrical fitting and the outer cylindrical fitting and connecting the two. In a cylindrical vibration isolator in which a drawing process is applied to a tube fitting, before drawing the outer tube fitting, a cutout is formed along the circumferential direction at an end of the rubber elastic body on the side of the enlarged diameter portion. The axial cross-sectional shape is formed in a substantially rectangular shape, and the axial end is
An annular curving portion is provided on the axial center end of the inclined portion or separated from the end in the axial center direction, and the amount of rubber at the axially opposite end of the rubber elastic body is provided. A cylindrical vibration isolator characterized by increasing the number of vibrations.