JPH06280939A - Strut mount insulator - Google Patents

Abstract

PURPOSE:To prevent generation of impact sounds at the time of operation and enhance the durability of a projection while an excellent vibration isolating effect with an insulator rubber is secured. CONSTITUTION:A core 30 fixed to a piston rod 22, a stopper rubber 34 mounted on the ring-shaped part 32 of the core 30 through a stopper part 33, and an insulator rubber 35 coupled with the ring-shaped part 32 at its periphery are accommodated in a casing 23 which is secured to a panel 21 of a car body. A plurality of projections 36, 37 in contact always with the casing 23 are provided on the oversurface and undersurface of the stopper rubber 34, while recesses 38, 39 to absorb the compressive deformations of the projections 36, 37 are furnished above and below the stopper part 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strut mount insulator for a MacPherson strut suspension.

[0002]

2. Description of the Related Art A conventional strut mount insulator of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 57-191110.
The ones described in Japanese Patent Publications and the like are known.

The outline will be described with reference to FIG. 8. This strut mount insulator is interposed between the vehicle body panel 1 and the upper end portion of the piston rod 2 of the shock absorber, and is attached to the vehicle body panel 1 by bolts 4 and nuts 5. A substantially cup-shaped casing body 3 that is fixed, a core member 7 that is fixed to the upper end of the piston rod 2 by a nut 6 and is housed in the casing 3, and has a substantially M-shaped cross section. A substantially annular insulator rubber 9 fixed by vulcanization between the outer peripheral portion and the inner peripheral surface of the casing body 3a via a metal annular member 8 and vulcanized and adhered to the inner and outer peripheral surfaces of the core 7. It has a stopper rubber 10.

A fixed gap C1 is formed between the upper surface 10a of the stopper rubber 10 and the lower surface 3c of the upper wall of the casing body 3a.
A constant gap C2 is formed between the lower surface of the lower portion 10b of 0 and the upper surface 3d of the casing cover 3b provided in the lower portion of the casing body 3a. Furthermore, the elastic coefficient of the insulator rubber 9 is set to a sufficiently small value.

A relatively large vertical external force transmitted from a wheel (not shown) via the coil spring 11 or the bumper bar 12 elastically deforms the elastic member 14 below the upper spring seat 13 to absorb the shock. After that, it is transmitted to the vehicle body panel 1 through the upper spring seat 13, the bearing 15, and the case cover 3b in this order.

In the case of high-frequency vibration with a small amplitude, the vertical external force transmitted from the wheel via the piston rod 2 is transmitted to the casing body 3a via the core material 7 while elastically deforming the insulator rubber 9. When
The deformation of the insulator rubber 9 effectively absorbs high-frequency vibrations and enhances the vibration damping effect.

Further, when the amplitude of the vertical force transmitted from the piston rod 2 is large, the insulator rubber 9 is largely elastically deformed, and the stoppers 7 above and below the core member 7 are formed.
a and 7b are upper and lower portions 10a and 10b of the stopper rubber 10.
Via the lower surface 3c of the upper wall of the casing body 3a and the upper surface 3d of the casing cover 3b via the stopper rubber 1
The upper and lower parts 10a and 10b of 0 are compressed and deformed to absorb the collision force.

[0008]

However, in the conventional strut mount insulator described above, the upper portion 10a of the upper stopper rubber 10, the lower surface 3c of the upper wall of the casing body 3a, the lower portion 10b of the stopper rubber 10 and the upper surface of the casing cover. A constant gap C with 3d
Since C1 and C2 are formed, a relatively large tapping sound is generated when the upper and lower portions 10a and 10b of the stopper rubber 10 collide with the upper wall lower surface 3c and the upper surface 3d, respectively, by a large external force as described above.

Therefore, in order to prevent the generation of such a tapping sound, the vertical lengths of the upper and lower portions 10a and 10b are extended so that the entire upper and lower end surfaces of the respective upper and lower portions 10a and 10b become the upper wall lower surface 3c. It is possible to always contact the upper surface 3d to eliminate the gaps C1 and C2. However, in this case, the rigidity of the stopper rubber 10 is increased and the upper and lower spring constants of the entire insulator are increased.

[0010]

SUMMARY OF THE INVENTION The present invention has been devised in view of the problems of the conventional strut mount insulator described above.
A core member fixed to the upper end of the piston rod is housed, the outer peripheral surface of the core member is joined to the casing by an insulator rubber, and the casing is attached to the outer peripheral part of the core member when the piston rod moves up and down by a certain amount or more. In a strut mount insulator provided with a stopper rubber that abuts against the lower surface of the upper wall and the upper surface of the lower wall, at least one of the upper and lower surfaces of the stopper rubber is always in contact with the lower surface or the upper surface of the lower wall of the casing. The present invention is characterized in that a plurality of protrusions are provided, and at the same time, a recess is provided at a portion of the core material corresponding to each protrusion forming position.

[0011]

According to the present invention having the above-mentioned structure, in the case of high frequency vibration in which the vertical external force transmitted from the piston rod is small, the high frequency vibration is effectively absorbed by the insulator rubber. That is, when the amplitude of the external force is large, the protrusion of the stopper rubber is compressed and deformed as it is, for example, on the lower surface of the upper wall of the casing to avoid a collision, and a tapping sound is prevented.

Moreover, since the bottom portion of the compression-deformed protrusion is absorbed in the recess via the stopper rubber, the overall compression strain is reduced. For this reason, sufficient durability can be secured without causing cracks or damage to the protrusions after a long period of time.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of a strut mount insulator according to the present invention, and the basic structure is the same as that of the conventional example.

That is, the strut mount insulator is interposed between the vehicle body panel 21 and the piston rod 22, and the substantially bowl-shaped casing 23 is a casing body 24 and a casing provided at the lower end of the casing body 24. The cover 25 is fixed to the vehicle body panel 21 together by bolts 26 and nuts 27.

Inside the casing 23, a metallic annular member 28 is press-fitted and fixed to the inner peripheral surface of the casing body 24, and a metallic member fixed to the upper end 22a of the piston rod 22 by a nut 29. A core material 30 is stored. As shown in FIGS. 1 and 2, the core member 30 is bent into a substantially U-shaped cross section by press molding, and has a piston rod upper end 22a through a central rod insertion hole 30a.
It is mainly composed of a flat base portion 31 fixed to the base portion 31 and an annular portion 32 rising from the outer peripheral edge of the base portion 31. Further, a cylindrical stopper portion 33 made of a synthetic resin material is attached to the outer peripheral surface of the annular portion 32.

A stopper rubber 34 is attached to the inner and outer peripheral surfaces of the stopper portion 33, and an annular insulator rubber 35 is provided between the outer peripheral surface of the stopper rubber 34 and the annular member 28. Are joined.
The insulator rubber 35 has a relatively small elastic coefficient as in the conventional case.

On the upper and lower end surfaces of the stopper rubber 34, as shown in FIG. 1, four substantially triangular projections 3 are formed.
6, 37 are integrally provided. This upper protrusion 36
And the lower protrusion 37 are arranged at equal intervals (90 °) in the circumferential direction.
(Position) and the whole is wavy,
They are arranged alternately on the upper and lower sides. The upper edge 36a of the upper protrusion 36 is always in contact with the lower surface 24a of the upper wall of the casing body 24, while the lower protrusion 37 is
The lower end edge 37a of the upper surface 25a of the casing cover 25.
Is always in contact with.

The stopper portion 33 is shown in FIGS.
As shown in, the annular protrusion 33a for strengthening the coupling property with the stopper rubber 34 is integrally provided on the outer periphery of the upper portion, and at the upper surface position corresponding to the formation position of the upper protrusion 36,
While the first recess 38 is formed, the second recess 39 is formed at the lower surface position corresponding to the formation position of the lower protrusion 37. The first and second recesses 38, 39 are formed in a substantially trapezoidal shape along the circumferential direction, and the depth thereof is drilled to the vicinity of the core material 30.

Reference numeral 32a in FIGS. 1 and 2 is a concave groove formed on the upper end of the annular portion 32 for restricting free rotation of the stopper 33 after fixing.

Therefore, according to this embodiment, when the vertical external force transmitted from the wheels to the piston rod 22 while the vehicle is traveling is high-frequency vibration having a small amplitude,
When the insulator rubber 35 is transmitted from the core material 30 through the stopper portion 33 to the insulator rubber 35, the insulator rubber 35 is deformed and effectively absorbs the high frequency vibration, and the vibration isolation effect is enhanced.

On the other hand, when the vibration of the external force is a low frequency vibration or the like, each protrusion 36 of the stopper rubber 34,
While 37 is in contact with the lower surface 24a of the upper wall of the casing body 24 and the upper surface 25a of the casing cover 25, it is compressed and deformed as it is. Subsequently, the upper and lower portions of the stopper rubber 34 are compressed and deformed, and the upper and lower end portions of the stopper portion 33 hit the upper and lower surfaces 24a and 25a via the stopper rubber 34, and further vertical movement is restricted. For this reason,
Excessive deformation of the insulator rubber 35 is suppressed,
As a result, the elastic coefficient can be made as small as possible, and the vibration damping effect is also improved.

Further, the projections 36 and 37 have the upper wall lower surface 24a.
Since the stopper rubber 34 is constantly in contact with the upper surface 25a, it is possible to sufficiently prevent the tapping sound from being generated due to the collision between the stopper rubber 34 and the upper wall lower surface 24a and the upper surface 25a.

Moreover, the protrusions 36 and 37 which are compressed and deformed
The bottom side, that is, the upper and lower portions of the stopper rubber 34 corresponding to the lower portions of the protrusions 36 and 37 are deformed and absorbed in the recesses 38 and 39, respectively, so that the compressive strain of the entire protrusions 36 and 37 becomes small. As a result, the durability of the protrusions 36 and 37 is improved, and it is possible to prevent the occurrence of cracks or damage over a long period of time.

Further, in this embodiment, since the stopper portion 33 is formed of a synthetic resin material, the degree of freedom of the shape is improved, and the compression deformation mode of the stopper rubber 34 and the protrusion portions 36, 37 can be arbitrarily set according to the elastic coefficient and the like. Can be set to.

Further, since the core material 31 can be formed by press molding, the manufacturing work is facilitated and the manufacturing cost can be reduced.

FIG. 7 shows a second embodiment of the present invention. The difference from the first embodiment is that the core material 40 is formed by cold forging instead of press molding, and is replaced by a stopper portion of synthetic resin material. The annular portion 42 of the core material 40 serves as a stopper portion. Further, a stopper rubber 44 is vulcanized and adhered to the outer peripheral surface of the annular portion 42 to cover the annular portion 42.
Recesses 48 and 49 are formed at positions corresponding to the protrusions 46 and 47 of the upper and lower end portions 43a and 43b. The other structure is the same as that of the first embodiment.

Therefore, this embodiment can obtain the same effects as those of the first embodiment, the structure can be simplified, and the weight can be reduced.

Although the projections 46 and 47 and the recesses 48 and 49 are provided above and below the annular portion 42 in this embodiment, they may be formed on only one of them.

[0030]

As is clear from the above description, according to the strut mount insulator of the present invention, the insulator rubber effectively absorbs the high frequency vibration transmitted from the piston rod. Of course, improvement can be achieved, and at the time of vibration with a large amplitude, the projection can reliably prevent the impact striking sound between the stopper rubber and the casing.

Moreover, since the compressive deformation of the protrusion is absorbed in the recess, the compressive strain of the protrusion is sufficiently reduced, the durability is improved, and cracks or damages of the protrusion occur over a long period of time. Can be prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a strut mount insulator showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a cored bar and a stopper portion used in this embodiment.

FIG. 3 is a plan view of the core member and a stopper portion.

FIG. 4 is a view on arrow A of FIG.

FIG. 5 is a bottom view of the core member and the stopper portion.

FIG. 6 is a view on arrow B of FIG.

FIG. 7 is a cross-sectional view showing a second embodiment of the present invention.

FIG. 8 is a transverse cross-sectional view showing a state in which a conventional strut mount insulator is attached to a vehicle body and a piston rod.

[Explanation of symbols]

 21 ... Body panel 22 ... Piston rod 23 ... Casing 24 ... Casing body 24a ... Upper wall lower surface 25 ... Casing cover 25a ... Upper surface 30, 40 ... Core material 34 ... Stopper rubber 36, 37, 46, 47 ... Protrusions 38, 39 , 48, 49 ... Recesses

Claims (1)

[Claims] 1. Inside a casing fixed to a vehicle body,
A core member fixed to the upper end of the piston rod is housed, the outer peripheral surface of the core member is joined to the casing by an insulator rubber, and the casing is attached to the outer peripheral part of the core member when the piston rod moves up and down by a certain amount or more. In a strut mount insulator provided with a stopper rubber that abuts against the lower surface of the upper wall and the upper surface of the lower wall, at least one of the upper and lower surfaces of the stopper rubber is always in contact with the lower surface or the upper surface of the lower wall of the casing. A strut mount insulator, characterized in that a plurality of protrusions are provided, and at the same time, a recess is provided at a portion corresponding to each protrusion forming position of the core material.