JPH0570010B2 - - Google Patents

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a method of manufacturing a bush filled with viscous fluid, and in particular to a bush-type anti-vibration support for automobiles that utilizes viscous resistance due to shearing of a highly viscous fluid sealed inside. The present invention relates to a method by which a body can be advantageously manufactured.

(Background Art) Anti-vibration supports for automobiles, such as body mounts or cab mounts, member mounts, strut bar couplings, tension rod bushings, arm bushings, or FF engine roll stoppers, are generally used to prevent sudden starts, sudden braking, and engine roll stoppers. High damping characteristics against low-frequency, large-amplitude vibrations input during shake, etc., and high vibration insulation against high-frequency, small-amplitude vibrations input from the engine, road surface, etc. during driving, that is, low dynamic spring characteristics are required.

However, as long as a solid rubber material is used as the anti-vibration rubber of such an anti-vibration support, the above-mentioned characteristics are generally contradictory, so it is difficult to realize a anti-vibration support with satisfactory anti-vibration characteristics. was extremely difficult.

On the other hand, in recent years, vibration-proof supports having a fluid-filled structure have been proposed (see Japanese Patent Publication No. 48-36151, Japanese Patent Publication No. 52-16554, etc.). Such a fluid-filled vibration isolating support is equipped with two fluid chambers, and an orifice is provided in the part that separates the two fluid chambers, so that one fluid chamber can be damaged by vibration input. A structure is adopted in which the volume of the fluid chamber changes and the sealed fluid is forced to flow back and forth into the other fluid chamber through an orifice. As the fluid flows through the orifice, viscous force and inertial force are exerted as the fluid flows through the constricted tube, resulting in high damping characteristics in the required frequency range, especially low-frequency vibrations. can be effectively demonstrated.

However, in the case of such a fluid-filled vibration damping support, its vibration damping characteristics are highly frequency dependent, and especially in the high vibration frequency range above the resonance point caused by the inertial force of the orifice, the stiffness of the support As a result, the low dynamic spring characteristics in the high frequency range were not sufficient, and good vibration isolation could not be expected, and the structure was complicated, resulting in high costs. There was a problem.

Therefore, in view of these circumstances, the applicant of the present application previously proposed in Japanese Patent Application No. 167440/1983 a method that prevents the support from becoming rigid in the high frequency range and exhibits flat transmission force characteristics with respect to the vibration frequency. As a bush-type viscous fluid chamber-enclosed type vibration-proof support, the inner cylindrical metal fittings and
A cylindrical rubber elastic body is interposed between an outer cylindrical metal fitting that is positioned concentrically or eccentrically on the outside, and the metal fittings are connected, and the axially intermediate part of the rubber elastic body is , an annular space having an opening opening on the outer circumferential surface and extending continuously in the circumferential direction with a predetermined width is provided, and the opening of this space is sealed by covering it with the outer cylindrical metal fitting. The annular fluid chamber is formed into one annular fluid chamber, and a high viscosity fluid with high kinematic viscosity is sealed in the fluid chamber, while the annular fluid chamber is located on both sides of the inner cylindrical fitting in the direction perpendicular to the vibration input direction to be vibration-proofed. The fluid chamber portions of each are narrowed in the radial direction to form narrow shear gaps extending over a predetermined length in the vibration input direction, and the highly viscous fluid is We proposed a structure that induces viscous resistance due to shearing.

However, when manufacturing a viscous fluid-filled bushing having such a structure, it is necessary to follow the conventional method of manufacturing a fluid-filled vibration-proof support as disclosed in Japanese Patent Application Laid-Open No. 58-170608, etc. When enclosing a high viscosity fluid into the fluid chamber formed therein by assembling the inner cylindrical fitting, rubber elastic body and outer cylindrical fitting into the high viscosity fluid, A cleaning process is required because the enclosed fluid adheres to the entire outer surface of such an assembly, and because the fluid is a highly viscous fluid, cleaning is difficult. It had the following.

(Solution Means) Here, the present invention has been made against the background of the above-mentioned circumstances, and its gist is (a) from the inside in the radial direction to the outside, an inner cylinder metal fitting, a cylindrical rubber An elastic body and a cylindrical rigid sleeve are integrally fixed to each other and have a predetermined width in the circumferential direction, and are provided with an opening that penetrates the cylindrical wall of the rigid sleeve and opens outward. an annular cavity extending continuously from the inner cylindrical fitting in the axially intermediate portion of the rubber elastic body, and the annular cavity is located on both sides of the inner cylindrical fitting in a direction perpendicular to the vibration input direction to be vibration-isolated. (b) preparing a bush main body having narrow shear gaps each extending in the vibration input direction over a predetermined length by narrowing the respective portions in the radial direction; (c) preparing an outer cylinder fitting having a through hole in a cylinder wall that can be moved from a position above the opening of the cavity to a position above the rigid sleeve by rotation of the outer cylinder; inserting the metal fitting onto the outer peripheral surface of the bush main body so that the through hole thereof is positioned above the opening of the cavity of the bush main body to form an assembled body;
(d) A predetermined high viscosity fluid with high kinematic viscosity is passed through the through hole of the outer cylindrical metal fitting of the assembled body, and the opening of the cavity of the bush body is covered with the outer cylindrical metal fitting. (e) After introducing the high viscosity fluid into the fluid chamber, the outer cylindrical metal fitting and the bush main body of the assembled body are rotated about an axis relative to each other. A method for manufacturing a viscous fluid-filled bushing, comprising the steps of: locating the through hole of the outer cylindrical fitting on a rigid sleeve of the bushing body to cut off communication between the fluid chamber and the outside. It is in.

(Example) Hereinafter, in order to clarify the present invention more specifically, an example of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 and 2 show a tension rod bushing 10 as an example of a viscous fluid-filled bushing assembly to be manufactured by the method of the present invention.
It is shown.

This tension rod bushing 10 has a structure that follows the viscous fluid-filled bushing proposed by the applicant in the above-mentioned Japanese Patent Application No. 167440/1982, and includes a thick-walled cylindrical inner pipe fitting 12, and Cylindrical outer tube fitting 1 arranged concentrically on the outside
4, these inner cylindrical fittings 12 and outer cylindrical fittings 14 are connected. A rubber block (including a rubber elastic body 16) having a generally cylindrical shape as a whole is molded from a predetermined rubber material, and a cylindrical attachment portion at the end of the tension rod is attached to the outer peripheral surface of the outer cylindrical fitting 14. While being press-fitted and attached, a pivot attached to the vehicle body side or the axle side is inserted into the inner cylinder metal fitting 12 for use.

A method of manufacturing a bushing assembly having such a structure will be explained below.

That is, when manufacturing the bushing main body 18 as shown in FIGS. 3 and 4,
is created. The bush main body 18 is generally formed by integrally fixing the inner cylindrical metal fitting 12 and the rubber block 16 by integral vulcanization molding. There, the inner cylinder fitting 1
A thick metal ring 20 is press-fitted and fixed onto the outer circumferential surface of the substantially central portion of the rubber block 16 in the axial direction.A metal sleeve 22 is fixed to the outer circumferential surface of one of the rubber blocks 16. Further, the metal sleeve 22 is provided with two windows 24, 24, which are formed by cutting out a large rectangular shape from the cylindrical wall thereof, and are symmetrically provided in the radial direction. By vulcanizing the rubber block 16 in the presence of the metal ring 20, inner cylindrical fitting 12, and metal sleeve 22, the desired bushing body 18 as an integrally vulcanized product is formed. be. Note that, after vulcanization molding, this bush main body 18 is subjected to a drawing process such as an eight-way drawing process as necessary, and is subjected to preliminary compression.

Further, in the bush main body 18, an annular space 26 is formed in the axially intermediate portion of the rubber block 16, and has a predetermined width and extends continuously in the circumferential direction. As is clear from the figure, the metal sleeve 22 is structured to open into the outer circumferential surface of the rubber block 16 at portions corresponding to the respective windows 24, 24.

Then, so as to be located within such empty space 26,
A metal ring 20 is press-fitted into the inner cylindrical fitting 12, and rubber of a predetermined thickness is placed on both axial side surfaces of the metal ring 20 and on the outer peripheral surface corresponding to the windows 24, 24 of the metal sleeve 22. is integrally molded with the rubber block 16. That is, in this embodiment, the inner surface is protected by the metal ring 20 and the rubber layer 30 integrally vulcanized and bonded to a predetermined thickness on the outer peripheral surface corresponding to the windows 24, 24. A plateau-like protrusion 28 is formed that protrudes radially outward from the cylindrical metal fitting 12 side. On the other hand, the rubber layer 30 in such a metal ring 20
Both sides of the radial direction in the direction perpendicular to the radial direction in which the radial direction is formed are each cut out in parallel to the tangential direction with a predetermined length, and the end surfaces of the cutout portions and the rubber block 16 face parallel to each other. As a result, the hollow space 26 portions located on both sides of the inner cylinder fitting 12 in the direction orthogonal to the radial direction in which the plateau-like protrusion 28 is formed are respectively narrowed in the radial direction. They are formed as shear gaps 32 each extending a predetermined length in parallel directions and having a narrow U-shaped or U-shaped cross section (FIG. 4). Note that this shear gap 32
is generally formed as a gap of about 6 mm.

On the other hand, in a step different from the step of forming the bush main body 18, the outer cylindrical metal fitting 14 as shown in FIGS. 5 and 6 is formed. On the inner circumferential surface of the outer cylindrical metal fitting 14, a sealing rubber layer 36 having a sealing lip 40 at each end in the axial direction is integrally provided by vulcanization adhesion or the like, and at the center in the axial direction. A through hole 3 that radially penetrates the outer cylindrical fitting 14 and the seal rubber layer 36 is provided at a portion facing each other in the radial direction.
8,38 are provided.

Here, these through holes 38, 38 are
As will be described later, when the outer cylindrical metal fitting 14 is fitted onto the outer circumferential surface of the bush main body 18, at a certain relative rotation position of these two members, the hollow space 26 formed in the bush main body 18 will open. from the rotational position in which the two members are positioned over the opening of and communicated with the cavity 26 and in such a communicating state, these two members are rotated relative to each other by a predetermined angle around the axis. In particular, its size and formation position are such that it can be moved to a position on the metal sleeve 22 and communication with the cavity 26 is blocked.

As described above, the bush main body 18 and the outer cylindrical metal fitting 14 are formed separately, and the outer cylindrical metal fitting 14 is placed on the outer circumferential surface of the bush main body 18, as shown in FIGS. 7 and 8. is extrapolated to form the assembled body 42. That is, in the case of this assembly 42, the space 26 of the bush main body 18
The opening is covered by the outer cylindrical fitting 14, thereby forming one annular fluid chamber 44 having a predetermined width around the inner cylindrical fitting 12. In addition, by covering the opening of the cavity 26 with the outer cylindrical fitting 14, the axis can be formed with a predetermined area between the plateau-like protrusion 28 protruding at the opening and the outer cylindrical fitting 14. A narrow arc-shaped gap 46 is formed that expands in the direction and circumferential direction. Note that, like the shearing gap 32, this gap 46 is also formed at a gap of about 1 to 6 mm.

In addition, here, such a bush main body 18
When inserting the outer cylinder fitting 14 into the outer cylinder fitting 14, the through holes 38, 38 provided in the outer cylinder fitting 14 are
This is done in a relative positional relationship around the axis such that the bushing body 18 is positioned over the opening of the cavity 26 formed in the bush body 18. The fluid chamber 44 is communicated with the outside via the through holes 38, 38.

Then, for such an assembly 42, a high viscosity fluid injection nozzle is connected to one of the through holes 38 provided in the outer cylindrical fitting 14, or only the one through hole 38 portion is filled with high viscosity fluid. Under a condition in which a predetermined high viscosity fluid can be guided to the through hole 38 by immersing it in a fluid, the other through hole 38 is connected to a negative pressure source, etc. By removing the air from the fluid chamber 44, high viscosity fluid is introduced into the fluid chamber 44 of the assembled body 42.

In addition, as such a high viscosity fluid, for example, 1000
A fluid such as silicone oil having a kinematic viscosity of centistokes or more, preferably 10,000 centistokes or more, more preferably 100,000 to 1,000,000 centistokes is preferably used.

After introducing the high viscosity fluid into the fluid chamber 42, the outer cylinder fitting 14 and the bush main body 18 of the assembled body 42 are rotated relative to each other around the axis. The through holes 38, 38 provided in the metal fitting 14 are inserted into the metal sleeve 2 of the bush body 18.
2 on the outer peripheral surface, thereby forming a fluid chamber 44.
The communication between the fluid chamber 44 and the outside is cut off, and the filling of the highly viscous fluid into the fluid chamber 44 is completed.

After filling the fluid chamber 44 with the highly viscous fluid, the outer cylindrical fitting 14 is subjected to a drawing process such as an eight-way drawing process, and further a drawing process such as passing through a predetermined die. By performing the diameter reduction process, in addition to the seal rubber layer 36,
The fluid tightness between the outer cylinder fitting 14 and the metal sleeve 22 is improved. Further, both ends of the outer cylinder fitting 14 are fixed to the metal sleeve 22 on the outer periphery of the bush main body 18 by roll caulking, thereby achieving the desired purpose as shown in FIGS. 1 and 2. Tension rod
Bush 10 is completed.

That is, in the tension rod bushing 10 of this embodiment manufactured by such a method, when vibration is input in the vertical direction in FIG. , a narrow shear gap 3 located in the left-right direction)
2 and 32, based on the relative movement of the opposing working surfaces (rubber block 16, metal ring 20) forming the shear gap 32, an effective shear action is induced on the high viscosity fluid present there. , a predetermined viscous resistance is generated due to the shearing of the viscous fluid, and the inner cylinder fitting 1
In the narrow gaps 46, 46 located on both sides (in the vertical direction in FIG. By applying a circumferential displacement action, a flow is induced in the highly viscous fluid, and a shear stress proportional to the velocity gradient of the flow is generated.
This allows the bush as a whole to exhibit an extremely effective vibration damping effect.

According to the method of this embodiment, when manufacturing the tension rod bush 10 having such an excellent vibration damping effect, it is possible to introduce a predetermined high viscosity fluid into the fluid chamber 44 formed inside the tension rod bush 10. As described above, this is carried out through one of the through holes 38 provided in the outer cylindrical fitting 14, and after the introduction, the outer cylindrical fitting 14 is rotated by a predetermined angle around the axis relative to the bush main body 18. Then, by closing the through hole 38, the sealing is performed, so that the bush 1 is sealed.
0 The adhesion of highly viscous fluid to the outer circumferential surface can be reduced as much as possible, and therefore there is no need to clean the entire surface of the bush 10 after filling the highly viscous fluid, and its manufacturability is extremely effectively improved. It is also advantageous in terms of cost.

Further, in this embodiment, one of the through holes 38
When the high viscosity fluid is introduced into the fluid chamber 44 through the through hole 38, the air inside the fluid chamber 44 is forcibly discharged through the other through hole 38. This has the advantage that the introduction into the bush 10 can be carried out extremely quickly and efficiently, thereby further improving the manufacturability of the bush 10.

In addition to these illustrative examples, the present invention can be modified, modified, improved, etc. based on the knowledge of those skilled in the art without departing from the spirit of the present invention. , and should be understood to include such embodiments.

For example, in the embodiment, the through hole 38,
38 was formed at a portion facing the outer cylinder fitting 14 in the radial direction;
The outer cylindrical fitting 14 is not limited as long as it can be communicated with the inside and the communication can be cut off by rotation of the outer cylindrical fitting 14 around the axis relative to the rubber block 16. It is also possible to provide them in series in the axial direction.

Further, such forced evacuation of air through one of the through holes 38 is not essential to the present invention.

Furthermore, it is not necessary to provide two such through holes 38, and it is also possible to introduce fluid and exhaust air from one through hole, and it is also possible to provide three or more such through holes. It may also be provided.

Furthermore, it goes without saying that the structure of the bushing to which the present invention is applied should not be construed as limited by the tension rod bushing 10 shown in the above embodiment, and in particular, the structure of the bushing to which the present invention is applied should not be interpreted as being limited.
The present invention can be effectively applied even to bushings in which a vibration damping effect is exerted only by the action of the shear gap 32 without the shear gap 32 being formed.

Furthermore, vibration-proof supports for bushing structures to which the method of the present invention is applied include, in addition to tension rod bushings as illustrated, many automotive applications such as body mounts, strut mounts, arm bushings, and FF engine roll stoppers. Anti-vibration rubber can be mentioned, and it can be advantageously applied to any of them.

(Effects of the Invention) As is clear from the above explanation, according to the manufacturing method of the viscous fluid-filled bushing of the present invention, a predetermined high viscosity fluid can be introduced into the annular fluid chamber formed in the assembled body. is carried out through a through hole provided in the outer cylindrical metal fitting, and after the introduction, the outer cylindrical metal fitting is rotated at a predetermined angle around the axis relative to the rubber block to close the through hole. Therefore, when the high viscosity fluid is sealed, the adhesion of the high viscosity fluid to the outer peripheral surface of the bushing can be reduced as much as possible. There is no need to clean the entire surface of the bush,
Its manufacturability can be extremely effectively improved, and it can also be manufactured cost-effectively.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a specific example of a viscous fluid-filled bushing to be manufactured by the manufacturing method according to the present invention, FIG. 2 is a cross-sectional view taken from FIG. 1, and FIG. FIG. 4 is a cross-sectional view showing a bush main body formed in one manufacturing process of such a bush, and FIG. 4 is a cross-sectional view taken at - in FIG. 3. Similarly, FIG. 5 is a cross-sectional view showing an outer cylindrical metal fitting formed in one manufacturing process of such a bush, and FIG. 6 is a cross-sectional view taken from the side in FIG. 5. Further, FIG. 7 is a cross-sectional view showing an assembly formed by fitting the outer cylindrical metal fitting onto the bush main body, and FIG. 8 is a cross-sectional view taken from FIG. 7. 10: Tension rod bush, 12: Inner cylinder metal fitting, 14: Outer cylinder metal fitting, 16: Rubber block,
18: Button body, 20: Metal ring, 22:
Metal sleeve, 24: window, 26: void, 28:
Plateau-like protrusion, 30: rubber layer, 32: shear gap,
36: Seal rubber layer, 38: Through hole, 42: Assembly body, 44: Fluid chamber, 46: Gap portion.

Claims (1)

[Scope of Claims] 1. An inner cylindrical metal fitting, a cylindrical rubber elastic body, and a cylindrical rigid sleeve are integrally fixed to each other from the inside in the radial direction to the outside, and the cylindrical wall of the rigid sleeve is with an opening opening outward through the
An annular space extending continuously in the circumferential direction with a predetermined width is provided in the axially intermediate portion of the rubber elastic body, and on both sides of the inner cylindrical fitting in a direction perpendicular to the vibration input direction to be vibration-isolated. preparing a bushing body in which each of the annular hollow portions is narrowed in the radial direction to form a narrow shearing gap extending over a predetermined length in the vibration input direction; preparing an outer cylinder fitting having a through hole in the cylinder wall that can be moved from a position above the opening of the cavity to a position above the rigid sleeve by rotation about an axis; a step of externally inserting a metal fitting onto the outer peripheral surface of the bush main body so that the through hole thereof is positioned above the opening of the cavity of the bush main body to form an assembled body; introducing a predetermined high viscosity fluid with high kinematic viscosity through the through hole of the metal fitting into an annular fluid chamber formed by covering the opening of the cavity of the bush body with the outer cylindrical metal fitting; After introducing the high viscosity fluid into the fluid chamber, the outer cylindrical metal fitting of the assembled body and the bushing main body are relatively rotated around the axis, and the through hole of the outer cylindrical metal fitting is inserted into the rigid sleeve of the bushing main body. A method of manufacturing a viscous fluid-filled bushing, comprising the step of: blocking communication between the fluid chamber and the outside by placing the bushing above the fluid chamber. 2. At a portion of the annular fluid chamber located on both sides of the inner cylindrical fitting in the vibration input direction, the outer cylindrical fitting and at least the outer cylindrical fitting protrude from the inner cylindrical fitting side in the inner fluid chamber, respectively. The viscous fluid-filled bushing according to claim 1, wherein the metal fitting facing portion is configured as a narrow gap portion that expands over a predetermined area by a plateau-like protrusion made of a rubber elastic material. Production method. 3. The method of manufacturing a viscous fluid-filled bushing according to claim 1 or 2, wherein the highly viscous fluid is silicone oil having a kinematic viscosity of at least 1000 centistokes.