JPH0324916Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field) The present invention relates to a fluid-filled vibration-proof bushing that damps input vibration based on the flow resistance when fluid flows through an orifice. The present invention relates to a technology for preventing fluid sealed inside a fluid-filled anti-vibration bushing of the type formed in a part from leaking to the outside.

(Prior art) A cylindrical elastic member is interposed between an inner cylindrical metal fitting and an outer cylindrical metal fitting in a vibration isolating support that is installed in a vibration transmission system such as an automobile suspension and performs a vibration isolating function. There is a so-called bush type that consists of One type of such a bush type vibration isolating support is equipped with a plurality of fluid chambers and an orifice that allows the fluid chambers to communicate with each other. There are fluid-filled types that are made to flow. According to such a fluid-filled vibration damping bushing, a good vibration damping effect can be obtained based on the flow resistance when the fluid flows through the orifice.

By the way, various structures have been proposed for such fluid-filled anti-vibration bushings depending on usage patterns, target characteristics, etc., and one of them is (a) inner cylinder metal fitting and , (b) a cylindrical elastic member integrally fixed to the outer circumferential surface of the inner cylindrical metal fitting and having a plurality of pocket portions opening on the outer circumferential surface; (c)
(d) a metal sleeve integrally fixed to the outer circumferential surface of the elastic member and having a window portion corresponding to the openings of the plurality of pocket portions; (d) press-fitted and fixed to the outer circumferential surface of the metal sleeve; , a cylindrical shape having orifice grooves on the outer circumferential surface that allow the plurality of fluid chambers to communicate with each other, the plurality of fluid chambers being sealed with a predetermined incompressible fluid by closing the opening of the pocket portion; an orifice member; (e) the orifice formed on the outer circumferential surface of the orifice member, which is subjected to eight-way drawing and roll caulked at both ends and fitted to the outer circumferential surface of the orifice member; There is an orifice that is equipped with an outer cylindrical fitting that forms an orifice that closes the opening of the groove and allows the fluid chambers to communicate with each other. Since the length of the vibration can be increased, it is often used especially when low frequency vibrations are to be damped. The frequency of vibration that is damped based on the flow resistance of the incompressible fluid flowing through the orifice is:
It changes depending on the length of the orifice, and the longer the orifice, the lower the frequency can be.

(Problem) However, as mentioned above, (a) the inner cylinder fitting and (b)
Conventionally, in a fluid-filled vibration-isolating bushing that is equipped with an elastic member, (c) a metal sleeve, (d) an orifice member, and (e) an outer cylindrical fitting, and in which the orifice can be easily lengthened, O-rings were interposed between the corresponding axial ends of the metal ring and the orifice member, and fluid tightness between them was ensured by the O-rings. It cannot be said that the fluid tightness between the parts is necessarily good enough, and reliability tends to be compromised.

(Solution Means) Here, in order to solve such problems, the fluid-filled vibration-proof bushing according to the present invention has the following features:
In addition to (a) an inner cylindrical metal fitting, (b) an elastic member, and (c) a metal sleeve similar to the fluid-filled vibration-isolating bushing,
(d)'The central part in the axial direction is a thick orifice groove forming part, while the both ends in the axial direction are thin walls that extend outward in the axial direction from the inner peripheral part of the end surface of the orifice groove forming part. A predetermined incompressible fluid is sealed by closing the opening of the pocket portion, which is fixed to the outer peripheral surface of the metal sleeve by caulking performed on the caulking portion. (f) a cylindrical orifice member having an orifice groove formed on the outer circumferential surface of the orifice groove forming portion to form a plurality of fluid chambers, and (f) the shaft of the orifice member; The metal sleeve is integrally fixed to the inner circumferential surface of the caulked portions at both ends in the axial direction or the outer circumferential surface of both ends in the axial direction of the metal sleeve, and is sandwiched between them by the caulking process for the caulked portions. (g) a pair of pressed annular first seal rubber layers; (g) abutting against the axial end surfaces of the metal sleeve; A pair of annular end fittings with a hook-shaped cross section are press-fitted and fixed with the outer circumferential surface of the orifice groove forming portion of the orifice member being aligned with the orifice groove forming portion; The pair of end fittings and the orifice member are integrally assembled to the metal sleeve, and the pair of end fittings and the orifice member are fitted over the metal sleeve by roll caulking. ,
an outer cylindrical metal fitting that forms an orifice that closes the opening of an orifice groove formed in the orifice groove forming portion of the orifice member and allows the fluid chambers to communicate with each other; (h) an inner circumferential surface of the outer cylindrical metal fitting; a second seal rubber layer that is integrally fixed to the outer circumferential surface of the orifice groove forming portion of the orifice member and is pressed between the outer cylindrical metal fittings and the orifice groove forming portion of the orifice member; Constructed to include.

(Function/Effect) According to such a fluid-filled anti-vibration bushing,
Similar to the conventional fluid-filled vibration-isolating bushing, by forming the orifice groove in the circumferential direction of the orifice member, the orifice can be easily lengthened, and therefore it can easily exert a damping effect against low-frequency vibrations. It is possible to make it happen. Moreover, according to the fluid-filled vibration-isolating bushing according to the present invention, between the corresponding axial ends of the metal sleeve and the orifice member, and between the corresponding axial ends of the orifice member and the outer cylindrical fitting. To,
Since a rubber layer that is integrally fixed to one of them is inserted under pressure, there is a gap between the corresponding axial ends of the metal sleeve and the orifice member, and between the orifice member and the outer cylinder. Excellent fluid tightness is obtained between each corresponding axial end with the metal fitting, and therefore the incompressible fluid sealed in each fluid chamber is well prevented from leaking to the outside. This greatly improves the reliability of the bushing.

(Example) Hereinafter, in order to clarify the present invention more specifically, one example thereof will be described in detail based on the drawings.

First, FIGS. 1 and 2 show an example of the present invention, in which reference numeral 10 denotes an inner cylindrical metal fitting, which has a cylindrical shape, and a vibration transmission system is formed in its inner hole 12. It is adapted to be attached to a predetermined constituent shaft member by being inserted externally. And, as shown in FIGS. 3 and 4,
A cylindrical rubber elastic body 14 as an elastic member is integrally fixed to the outer peripheral surface of the inner cylindrical fitting 10 by vulcanization molding.

As shown in FIGS. 3 and 4, the rubber elastic body 14 has a pair of pocket portions 16, 16 facing each other with the inner cylinder fitting 10 interposed therebetween and opening on the outer peripheral surface thereof. is formed, and a metal sleeve 20 having window portions 18, 18 corresponding to the openings of the pocket portions 16, 16 is disposed on the outer peripheral surface of the metal sleeve 20, which is integrally fixed by vulcanization adhesive. ing. In this embodiment, it is located at the center of each of the pocket parts 16, 16,
Stopper block 22 fitted to inner cylinder metal fitting 10
are made to protrude from the bottom at a predetermined height, respectively.

Note that the rubber elastic body 14 is attached to the pocket portions 16, 1
The stopper block 6 is formed to cover the outer peripheral surface of the stopper block 22 protruding into the stopper block 6 with an appropriate thickness. Furthermore, the metal sleeve 20 has been previously subjected to an eight-way drawing process before being assembled to the bushing, thereby applying preliminary compression to the rubber elastic body 14.

As shown in FIGS. 1 and 2, a cylindrical orifice fitting 24 having the same length as the metal sleeve 20 is provided on the outer peripheral surface of the metal sleeve 20 fixed to the rubber elastic body 14. An annular end fitting 2 having a hook-shaped cross section is attached to the outer peripheral surface of both ends in the axial direction of the orifice fitting 24.
6 and 26 are respectively attached. A cylindrical outer metal fitting 28 is fitted and attached to a predetermined cylindrical member constituting the vibration transmission system.
It is fitted onto the outer circumferential surface of the orifice fitting 24 while spanning the end fittings 26, 26.

As shown in FIGS. 5 and 6, the orifice fitting 24 includes a thick orifice groove forming portion 32 in which a circumferential orifice groove 30 is formed on the outer peripheral surface, and It consists of a pair of thin caulked portions 34, 34 extending outward in the axial direction from the inner peripheral portions of both end faces in the axial direction, and as shown in FIGS. 1 and 2, The metal sleeve 2 is formed in the orifice groove forming portion 32 which is slightly longer than the forming width of the pocket portion 16.
The caulked portions 34, 3 at both ends are press-fitted into the outer peripheral surface of the
4 is fixed to the metal sleeve 20 by caulking. By being attached to the outer peripheral surface of the metal sleeve 20 in this way,
The openings of the pocket portions 16, 16 are closed, and a pair of fluid chambers 36, 36 are formed inside the rubber elastic body 14, facing each other with the inner cylindrical fitting 10 interposed therebetween.

In this embodiment, as shown in detail in FIG. 7, rubber layers 38, 38 of a predetermined thickness are formed by vulcanization on the inner peripheral surfaces of the caulked parts 34, 34 of the orifice fitting 24, respectively. By crimping the crimped parts 34, 34, as shown in FIGS. It is designed to be compressed between the metal sleeve 20 and the axial end thereof. In this embodiment, these rubber layers 38, 38 constitute the first sealing rubber layer, and these rubber layers 38, 38 constitute the first sealing rubber layer.
8 and 38 ensure fluid tightness between the corresponding axial ends of the orifice fitting 24 and the metal sleeve 20.

As shown in FIG. 7, two seal lips 40, 40 are formed on the inner circumferential surface of each seal rubber layer 38, so that the orifice fitting 24 and the metal sleeve 20 are connected to each other. Fluid tightness between corresponding axial end portions of the axial direction is more reliably ensured. Further, as shown in the figure, each of the caulking parts 34 has a tapered shape with its base end opening outward in the axial direction, so that the caulking process can be easily and satisfactorily performed. It's getting old.

Each of the end fittings 26 is made up of a cylindrical portion 42 and an inward flange portion 44 extending from one end thereof, as shown in FIG. As shown in FIG. 2, the cylindrical portion 42 is press-fitted and fixed to each caulked portion 34 of the orifice fitting 24. The wall thickness of the cylindrical portion 42 is set so that the outer circumferential surface of the cylindrical portion 42 coincides with the outer circumferential surface of the orifice forming groove 32 of the orifice fitting 24 in the press-fitted and fixed state, and the end surface of the cylindrical portion 42 The length dimensions of the cylindrical portion 42 and the flange portion 44 are set such that the cylindrical portion 42 and the flange portion 44 contact the end face of the orifice groove forming portion 32 and the flange portion 44 abuts the end face of the metal sleeve 20.

Further, as shown in FIG. 9, the outer cylindrical fitting 28 has a rubber layer 46 of a predetermined thickness on its inner peripheral surface.
It is integrally equipped with a
A predetermined dimension is made larger than the outer diameter of. Then, the end fittings 26 , 26 are fitted onto the orifice fitting 24 and subjected to an eight-way drawing process, and both ends in the axial direction are roll caulked to form the outer periphery of the orifice fitting 24. attached to the surface. By being attached to the outer peripheral surface of the orifice fitting 24 in this manner, the orifice fitting 24 and the end fittings 26, 26 are integrated with the metal sleeve 20, as shown in FIG. At the same time, the orifice fitting 24 and the end fittings 26, 2 are assembled.
6, the opening of the orifice groove 30 formed in the orifice groove forming portion 32 of the orifice fitting 24 is fluid-tightly closed, and the fluid chambers 36, 36 are communicated with each other. An orifice 48 is formed to allow this.

Orifice groove forming portion 32 of orifice fitting 24
The orifice groove 30 formed in FIGS.
As shown in Figures 5 and 6,
It is formed so as to go around the orifice fitting 24 a plurality of times in the circumferential direction. In this embodiment, through holes 5 are formed at both ends of the orifice groove 30.
0 and 50, the orifice groove 30 is communicated with the fluid chambers 36 and 36, respectively, and by closing the opening of the orifice groove 30 in a fluid-tight manner, the orifice 48 is being formed.

As is clear from the above description, in this embodiment, the rubber layer 46 integrally fixed to the inner surface of the outer cylinder fitting 28 constitutes the second sealing rubber layer. Therefore, fluid tightness between the corresponding axial ends of the outer cylinder fitting 28 and the orifice fitting 24 (more precisely, the orifice groove forming portion 32) is ensured, but in this embodiment,
Furthermore, as shown in FIG. 9, two seal lips 5 are provided on each portion of the rubber layer 46 corresponding to both ends of the orifice groove forming portion 32 in the axial direction.
2 are formed to further ensure fluid tightness between them.

Normally, as described above, the mounting operation of the orifice fitting 24, the pair of end fittings 26, 26, and the outer cylinder fitting 28 is performed in a predetermined incompressible fluid, thereby filling the fluid chambers 36, 36. The incompressible fluid is enclosed, and as shown in FIGS.
A fluid-filled anti-vibration bushing as shown in the figure is obtained. Note that these fluid chambers 36,
As the incompressible fluid sealed in the incompressible fluid 36, water, alkylene glycol, polyalkylene glycol, liquid low molecular weight polymer, etc. are employed.

According to such a fluid-filled anti-vibration bushing,
Since the fluid chambers 36 and 36 are formed to face each other with the inner cylinder fitting 10 in between, the orifice 4
Based on the flow resistance of an incompressible fluid flowing through 8,
These fluid chambers 36, 36 can exert a good damping effect on input vibrations in opposing directions, and since the orifice 48 is sufficiently long, it can provide good damping effect on low frequency vibrations. It can exert its effect. Also,
In this embodiment, as described above, the pocket portion 16,
16 (fluid chambers 36, 36), the stopper block 2 protrudes from the bottom by a predetermined height.
2 is arranged, the stopper block 22 comes into contact with the orifice fitting 24,
Excessive displacement between the inner cylindrical metal fitting 10 and the outer cylindrical metal fitting 28 can be restricted.

In this embodiment, in such a fluid-filled anti-vibration bushing, between the corresponding axial ends of the metal sleeve 20 and the orifice fitting 24, and between the orifice fitting 24 and the outer cylindrical fitting 28, Between the corresponding axial ends, as described above,
Orifice metal fitting 24 which is one member of each
Rubber layers 38, 38, and 46, which are integrally fixed and disposed on the outer cylinder fitting 28, are interposed in a compressed state, and these compressed rubber layers 38, 38, and 46 allow the rubber layers 38, 38, and 46 to Since fluid tightness is ensured between each corresponding axial end, extremely good fluid tightness can be obtained between each corresponding axial end. Therefore, each fluid chamber 36, 36
This effectively prevents the incompressible fluid sealed inside from leaking out to the outside, greatly improving the reliability of the bushing.

In addition, in this embodiment, the rubber layers 38 and 38, which are the first sealing rubber layers, are respectively attached to the orifice fitting 2.
Although these rubber layers 38, 38 can be integrally fixed and arranged on the metal sleeve 20 side, the second Rubber layer 4 which is a sealing rubber layer
6 can be integrally fixed and disposed on the orifice metal fitting 24 (orifice groove forming portion 32) side.

Further, in this embodiment, the length of the orifice 48 is significantly longer than the cross-sectional area;
As an example is shown in the figure and FIG. 11, the length and cross-sectional area of the orifice 48 can be changed as appropriate depending on the purpose.

Furthermore, in this embodiment, two fluid chambers 36, 3
Although the present invention has been described as an example in which the present invention is applied to a bushing in which the bushes 6 are formed to face each other across the bush axis, the present invention is not limited to this. It is also possible to apply the present invention to a bush in which more than one type of fluid chamber is formed, or a bush in which two types of fluid chambers are formed to face each other in the direction of the bush axis.

In addition, although not listed one by one, various modifications and changes may be made without departing from the spirit of the present invention.
Things that can be implemented with modifications, improvements, etc. are:
It goes without saying.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view (-cross-sectional view in FIG. 2) showing an example of a fluid-filled anti-vibration bushing according to the present invention, and FIG. 2 is a negative cross-sectional view in FIG. 1. 3 is a sectional view parallel to the axis of the bushing (- sectional view in FIG. 4) showing the integrally vulcanized molded product of the rubber elastic body in the embodiment shown in FIG. - It is a cross-sectional view. 5 and 6 are a longitudinal sectional view and a front view, respectively, showing the shape of the orifice fitting in the embodiment shown in FIG. 1 before the bushing is assembled, and FIG. 7 is an enlarged view of the main part of FIG. 5. be. FIG. 8 is a longitudinal sectional view showing the end fitting in the embodiment of FIG. 1;
FIG. 9 is a longitudinal sectional view showing the shape of the outer cylindrical metal fitting in the embodiment shown in FIG. 1 before the bush is assembled.
10 and 11 are views corresponding to FIGS. 5 and 6 showing an orifice fitting according to another embodiment of the present invention. 10: Inner cylinder metal fitting, 14: Rubber elastic body (elastic member), 16: Pocket part, 18: Window part, 20: Metal sleeve, 24: Orifice metal fitting, 26: End metal fitting, 28: Outer cylinder metal fitting, 30: Orifice groove, 3
2: Orifice groove forming part, 34: Caulking part, 3
6: fluid chamber, 38: rubber layer (first seal rubber layer), 40, 52: seal lip, 46: rubber layer (second seal rubber layer), 48: orifice.

Claims (1)

[Scope of Claim for Utility Model Registration] An inner cylindrical metal fitting; a cylindrical elastic member integrally fixed to the outer circumferential surface of the inner cylindrical metal fitting and having a plurality of pockets opening on the outer circumferential surface; and the elastic member. a metal sleeve integrally fixed to the outer peripheral surface of the member and having a window corresponding to the openings of the plurality of pockets; and an orifice groove forming portion having a thick wall in the central portion in the axial direction. On the other hand, both ends in the axial direction are thin-walled caulked portions extending outward in the axial direction from the inner peripheral portion of the end surface of the orifice groove forming portion, and the caulking process performed on the caulked portions The orifice groove forming portion is fixed to the outer circumferential surface of the metal sleeve and forms a plurality of fluid chambers in which a predetermined incompressible fluid is sealed by closing the opening of the pocket portion. A cylindrical orifice member provided with orifice grooves that allow a plurality of fluid chambers to communicate with each other; and an inner peripheral surface of a caulked portion at both axial ends of the orifice member or an outer periphery of both axial ends of the metal sleeve. a pair of annular first seal rubber layers that are integrally fixed to the respective faces and are pressed between them by the caulking process on the caulking portion; and A hook-shaped cross section is press-fitted into the caulked portions of both ends so as to be in contact with the end surfaces in the axial direction of the metal sleeve, and with the outer circumferential surface matching the orifice groove forming portion of the orifice member. a pair of annular end fittings, which are subjected to an eight-way drawing process and roll caulked to both ends, and are fitted across the pair of end fittings and the orifice member;
While the pair of end fittings and the orifice member are integrally assembled to the metal sleeve, the opening of the orifice groove formed in the orifice groove forming portion of the orifice member is closed to allow the fluid chambers to communicate with each other. an outer cylindrical metal fitting forming an orifice; and an orifice groove forming part of the outer cylindrical metal fitting and the orifice member, the outer cylindrical metal fitting being integrally fixed to the inner circumferential surface of the outer cylindrical fitting or the outer circumferential surface of the orifice groove forming portion of the orifice member. and a second sealing rubber layer compressed between the first and second parts.