JPH02134435A - Manufacture of viscous fluid sealed type bush - Google Patents

Abstract

PURPOSE:To make a filling operation ranging from injection of a viscous fluid to its sealing performable in very good condition by machining an outer cylinder fitting for diametral contraction, sticking it close to a rigid sleeve constituting a bush body, and sealing a space filled up with a viscous fluid. CONSTITUTION:After insertion and assembly to an outer cylinder fitting 14 of a bush body 18, drawing of multidirectional throttles or the like is applied to a large diametral part 42 of this outer cylinder fitting 14 and its diameter is contracted and thereby this large diametral part 42 is stuck close to a metal sleeve 22 of the bush body 18 via seal rubber 46 tightly attached to the inner circumferential surface, thus sealability between both these members is secured. In brief, with the drawing of diametral contraction, a space formed between the outer cylinder fitting 14 and the bush body 18 is fluid-tightly closed, and a high viscous fluid is sealed in the inner part so that a fluid storage space 54 is thus formed. Since this fluid storage space 54 is hermetically sealed by the contraction drawing to the outer cylinder fitting 14 and completed, a filling operation ranging from injection of the viscous fluid to its sealing is performable very quickly and easily.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a method of manufacturing a viscous fluid-filled bushing.
In particular, the present invention relates to a method for advantageously manufacturing a vibration-isolating bushing that can exhibit an excellent vibration-isolating effect based on viscous resistance caused by shearing of a highly viscous fluid sealed inside.

(Background Art) Conventionally, as a type of insulator that is interposed between a shaft member and a mounting member constituting a vibration transmission system to connect these two members in a vibration-proof manner, for example, a strut-type insulator for an FF automobile has been used. L, which is often used in front suspension vehicles
The compression rod, which is the pivot on the rear side of the vehicle in the lower arm, has a generally bottomed cylindrical shape as a whole, like a bushing inserted in the attachment part to the vehicle body frame side, and is fixed to a predetermined attachment member. A vibration-proof bushing is known in which a predetermined shaft member inserted into the inner hole is vibration-proof connected to the mounting member.

However, in conventional anti-vibration bushings with this type of structure, the anti-vibration effect is obtained only from rubber alone, so it is difficult to obtain a sufficient damping effect against input vibration. In particular, it has been extremely difficult to set large damping characteristics for input vibrations in the low frequency range.

Therefore, the applicant of this application first filed the patent application No. 62-94986.
In this issue, we proposed a viscous fluid-filled bushing with a viscous fluid sealed inside. Such a viscous fluid-filled bushing has a bottomed cylindrical inner metal fitting and an inner diameter larger than the outer diameter of the inner cylinder metal fitting, and covers the outer surface of the inner cylinder metal fitting at a predetermined distance. The bottomed cylindrical outer cylindrical fittings arranged as shown in FIG. while defining a fluid storage chamber in which a fluid is enclosed;
In this fluid storage chamber, a structure is formed in which narrow portions extending in the circumferential direction of the bushing or in the direction perpendicular to the axis are formed between opposing surfaces of the cylindrical portion or bottom of the inner cylindrical metal fitting and the outer cylindrical metal fitting. becomes.

In such a bushing, when vibration is input between the inner and outer cylinder fittings, each time the inner cylinder fitting and the outer cylinder fitting are relatively displaced (vibrated), the viscous fluid existing in the narrowed portion causes vibration. Since it can exhibit viscous resistance based on shearing, compared to conventional structures that provide vibration isolation based on the elastic properties of rubber alone,
It is possible to obtain extremely excellent vibration damping properties, especially good damping effects.

By the way, as a method for injecting and sealing fluid into the fluid storage chamber when manufacturing a bushing having such a structure, the method used for ordinary fluid-filled vibration-proof bushings, etc. (
(Refer to Japanese Unexamined Patent Publication No. 58-170608, etc.), by assembling the inner and outer cylindrical fittings in a predetermined fluid, or after assembling the inner and outer cylindrical fittings, the fluid is removed through a through hole drilled in the outer cylindrical fitting. It is conceivable to do this by injecting the through hole and then closing the through hole with a rivet or the like.

However, since the fluid enclosed in such a bushing is a highly viscous fluid such as silicone oil, the former method results in the highly viscous fluid adhering to the product surface, which requires an increased number of manufacturing steps to remove. The problem was that it caused an increase in manufacturing costs.
On the other hand, the latter method has problems such as it takes time to inject the fluid, the injection operation itself is difficult, and the manufacturing cost increases due to drilling and closing of the outer cylindrical fitting.

(Problem to be solved) Here, the present invention has been made against the background of the above-mentioned circumstances, and the problem to be solved is:
A predetermined high viscosity fluid can be easily injected and sealed into the fluid storage chamber formed in the bushing, and the viscous fluid-filled bushing having the above-mentioned structure can be manufactured with good productivity and manufacturing cost. Therefore, it is an object of the present invention to provide a manufacturing method that can be advantageously manufactured.

(Solution Means) In order to solve this problem, the present invention includes:
An inner cylindrical metal fitting with a bottom and a bottomed cylindrical outer metal fitting having an inner diameter larger than the outer diameter of the inner cylindrical metal fitting and arranged so as to cover the outer surface of the inner cylindrical metal fitting at a predetermined distance. The cylindrical metal fittings are elastically connected by a cylindrical rubber elastic body interposed between the openings thereof, thereby defining a fluid storage chamber in which a predetermined high-viscosity fluid is sealed between the inner and outer cylindrical metal fittings. On the other hand, a viscous fluid is sealed by forming a constricted portion extending in the circumferential direction of the bushing or in the direction perpendicular to the axis between the opposing surfaces of the cylindrical portion or the bottom of the inner cylindrical fitting and the outer cylindrical fitting in the fluid storage chamber. (a) The cylindrical rubber elastic body is integrally provided on the outer circumferential surface of the opening side of the inner cylindrical metal fitting, and further, on the outer circumferential surface of the cylindrical rubber elastic body, a rigid a step of preparing a bushing body to which the sleeve is fixed; (b)
) preparing the outer cylindrical metal fitting, which has an inner diameter larger than the outer diameter of the rigid sleeve constituting the bushing body on the open end side; (C) preparing the outer cylindrical metal fitting;
A step of injecting a predetermined amount of high viscosity fluid into the inside of the outer cylindrical metal fitting through the opening while the outer cylindrical metal fitting is held so as to open vertically upward; (e) inserting the bushing main body and placing the bushing main body and the outer cylindrical fitting in a state in which the space formed between them is filled with a highly viscous fluid; In the inserted state, the opening side portion of the outer cylindrical metal fitting is drawn to reduce its diameter and brought into close contact with the outer circumferential surface of the rigid sleeve in the bushing main body, thereby ensuring fluid tightness between them. The method is characterized in that it includes a step of completing the fluid storage chamber in which a highly viscous fluid is sealed.

(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 to 3 show a viscous fluid-filled bushing interposed in the attachment portion of a compression rod to a vehicle body frame in an L-shaped lower arm of an automobile, as an example of a viscous fluid-filled bushing to be manufactured by the method of the present invention. An anti-vibration bushing 10 is shown.

This anti-vibration bushing 10 has a structure that follows the viscous body-enclosed bushing proposed by the applicant in the aforementioned Japanese Patent Application No. 62-94986. An outer cylindrical fitting 1 having a bottomed cylindrical shape is arranged to cover the outer surface of the inner cylindrical fitting 12 at a predetermined distance.
4, and the inner cylindrical metal fitting 12 and the outer cylindrical metal fitting 14 are connected and integrated by a cylindrical connecting rubber 16 at the opening side end thereof.

The anti-vibration bushing 10 has an inner cylindrical fitting 12.
The compression rod of the L-shaped lower arm is inserted through and attached to the inner hole of the outer cylinder fitting 14.
However, it is used by being fixed to the vehicle body frame using a belt-shaped bracket with a U-shaped cross section.

Hereinafter, a method of manufacturing a bushing body having such a structure will be explained.

That is, when manufacturing it, firstly, the steps shown in FIGS.
A bushing body 18 is produced as shown in the figure. This bush main body 18 is formed by integrally fixing the inner cylindrical metal fitting 12 and the cylindrical connecting rubber 16.

More specifically, a cylindrical connecting rubber 16 is integrally provided on the outer circumferential surface of the open end side of the cylindrical wall portion 24 of the inner cylindrical metal fitting 12, and further, the outer circumferential surface of the cylindrical connecting rubber 16 is On the top, a metal sleeve 22 is provided with an outward flange-shaped portion 20 extending approximately half the circumference in the circumferential direction on one axial end side, and the metal sleeve 22 is disposed on the same axis as the inner cylinder fitting 12, and the flange-shaped portion 20 is disposed on the same axis as the inner cylinder fitting 12. , in a state located on the opening side of the inner cylinder fitting 12,
It is fixed integrally.

Further, on the outer circumferential surface of the bottom side of the cylinder wall portion 24 of the inner cylinder fitting 12, a substantially arc-shaped hard block 25.25 is provided.
are assembled and fixed from both sides in the radial direction, and the outer surfaces of these hard blocks 25 and 25 are covered with a rubber elastic body, so that they protrude outward in the radial direction at a predetermined height and extend all the way in the circumferential direction. A cylindrical first elastically acting protrusion 26 is formed which extends over the circumference. Furthermore, on the outer surface of the bottom wall portion 28 of the inner cylindrical fitting 12, a disc-shaped second elastic projection 30 that projects outward in the axial direction at a predetermined height is integrally formed with a rubber elastic body. It is set in.

By the way, such a bushing main body 18 is generally made by placing the inner cylindrical fitting 12 and the metal sleeve 22 in a predetermined mold, and then injecting a predetermined rubber material into the mold. By molding the shaped connecting rubber 16 and the first and second elastic protrusions 26 and 30 at the same time, they are formed as an integrally vulcanized molded product.

Further, in this embodiment, the cylindrical connecting rubber 16 and the first and second elastically acting projections 26 and 30 are integrally formed of a predetermined rubber elastic body, and the rubber elastic body is made of a predetermined rubber elastic body. As the molding material is guided to the inner circumferential surface of the inner cylindrical fitting 12, a thin inner rubber layer 34 is also formed on the inner circumferential surface.

Note that the metal sleeve 22 of the bushing main body 18 integrally vulcanized in this way is subjected to a diameter reduction process, if necessary, to reduce stress caused by shrinkage of the rubber elastic body during vulcanization. At the same time, the cylindrical connecting rubber 1
Appropriate pre-compression will be applied to 6.

On the other hand, the outer cylindrical metal fitting 14 is formed in a process different from the process of forming the bush main body 18. As shown in FIGS. 7 to 9, the outer cylindrical fitting 14 has a bottomed flange-like portion 36 extending approximately half the circumference in the circumferential direction at the opening side end. It is formed with a cylindrical shape. Note that caulking portions 38 are provided on the outer peripheral edges of the circumferential center portion and both end portions of the flange-like portion 36, respectively.

Further, the diameter of the opening side portion of the cylindrical wall portion of the outer cylindrical metal fitting 14 is increased over a predetermined length, so that the small diameter portion 4
It is formed with a stepped cylindrical shape consisting of a diameter portion 0 and a large diameter portion 42. The outer circumferential surface of the small diameter portion 40 is substantially entirely covered with a mounting rubber sleeve 44 having a predetermined thickness.

On the other hand, the large diameter portion 42 of the outer cylindrical metal fitting 14 is formed to have an inner diameter that is equal to or slightly larger than the outer diameter of the metal sleeve 22 constituting the bushing body 18, and has a slightly larger inner diameter. , a sealing rubber 46 is firmly fixed over the entire circumference.

Note that two seal lips 48, 48 extending in the circumferential direction are formed on the inner peripheral surface of the seal rubber 46. Further, in this embodiment, the seal rubber 46 is formed integrally with the mounting rubber sleeve 44.

In this way, the outer cylindrical fitting 14, which is formed separately from the bushing main body 18, is held so as to open vertically upward, as shown in FIG. , a predetermined amount of high viscosity fluid 49 is injected through the opening.

Here, the high viscosity fluid 49 has a kinematic viscosity of, for example, 1,000 centistokes or more, preferably 10,000 centistokes or more, and more preferably 100,000 to 1,000,000 centistokes in addition to obtaining sufficient viscous resistance. Fluids such as silicone oil and the like are preferably used.

After the high viscosity fluid 49 is injected, the bushing body 18, which is formed separately from the outer cylindrical fitting 14, is inserted into the outer cylindrical fitting 14, as shown in FIG. , will be combined.

Specifically, the bush main body 18 is connected to the inner cylinder fitting 12.
from the bottom wall 28 side of the housing, through the opening of the outer cylinder fitting 14,
The flange-shaped portion 20 of the inner tube fitting 12 and the flange-shaped portion 36 of the outer tube fitting 14 are inserted into the interior by a predetermined amount until they come into contact with each other, and as shown in FIG. The outer cylindrical metal fitting 14 and the bushing main body 18 are arranged concentrically.

In this arrangement, a space of a predetermined volume is formed between the opposing surfaces of the outer cylindrical fitting 14 and the bushing body 18 on the bottom side. In addition, by inserting and attaching the bushing body 18 to the outer cylindrical metal fitting 14, the first elastically acting protrusion 26 and the second elastically acting protrusion 30 provided on the outer peripheral surface of the bushing body 18 are The protruding end surface is
They are respectively positioned opposite to the inner circumferential surface of the outer cylindrical metal fitting 14 with a predetermined gap therebetween, so that both members 14
．． In the space formed between the two members 14.1, a cylindrical first narrowed portion 50 that extends between the cylindrical portions of both members 14.18 with a predetermined width over the entire circumference in the circumferential direction;
A disk-shaped second narrowing portion 52 is formed, which extends between the bottom portions of the holes 8 in the direction perpendicular to the axis.

In addition, as described above, the highly viscous fluid 49 is housed in the outer cylindrical fitting 14, and when the bushing body 18 is inserted, the insertion tip of the bushing body 18 is immersed in the fluid. With the insertion of the bushing body 18 from the point where it will be inserted,
The air existing in the space formed between the outer cylinder fitting 14 and the outer cylinder fitting 14 is discharged to the outside, thereby forming the first and second narrowed portions 50.
．． The space including 52 is filled with high viscosity fluid 49.

Note that, as is clear from this, the outer cylinder fitting 14
The amount of high viscosity fluid 49 injected into the bushing body 18 must be sufficient to fill the space formed between the two members 14 and 18 when the bushing body 18 is inserted. In order to prevent as much as possible from overflowing from the opening of the outer cylindrical fitting 14 when the main body 18 is inserted, it is necessary to set the amount not to be too large.

After inserting and assembling the bushing main body 18 into the outer cylindrical fitting 14, the large diameter portion 42 of the outer cylindrical fitting 14 is subjected to a drawing process such as helical drawing to reduce the diameter. As a result, the large-diameter portion 42 is brought into close contact with the metal sleeve 22 of the bushing body 18 via the seal rubber 46 fixed to its inner circumferential surface, thereby ensuring sealing between these two members. That is, in this diameter reduction process, the space formed between the outer cylindrical metal fitting 14 and the bushing body 18 is fluid-tightly closed, and the high viscosity fluid 49 is sealed therein. The high viscosity fluid 49
A fluid storage space 54 is formed in which the fluid is sealed.

Furthermore, the outer cylindrical fitting 14 has a flange-like portion 3.
By caulking and fixing the caulking portion 38 provided at 6 to the flange-like portion 20 of the inner cylinder fitting 12, it is firmly assembled to the bushing body 18, and thereby, as shown in FIG. The desired anti-vibration bushing 10 as shown in FIGS. 3 to 3 is completed.

That is, in the vibration-proof bushing 10 of this embodiment having such a structure, when vibration in the direction perpendicular to the bushing axis is caused by human force, the relative displacement (vibration) of the inner cylinder fitting 12 with respect to the outer cylinder fitting 14 is caused. ), in the fluid accommodation space 54, the first and second elastic protrusions 26.30 provided on the outer surface of the inner cylindrical fitting 10 are moved against the inner circumferential surface of the outer cylindrical fitting 14, respectively. This causes them to be moved relative to each other.
and against the viscous fluid existing in the first and second narrowed portions 50.52 formed between the protruding end surface of the second elastic action protrusion 26.30 and the inner circumferential surface of the outer cylindrical fitting 14. , respectively, and the predetermined viscous resistance caused by the shearing of the viscous fluid can provide an excellent damping effect over a wide frequency range.

In addition, in the vibration-proof bushing 10 having such a structure, when an excessive vibration load is input between the inner and outer cylindrical fittings 12 and 14,
Outer cylinder fitting 14 of the first and second elastic action protrusions 26.30
By abutting against them, they can also function as a so-called stopper, regulating the relative displacement of both of the tools 12 and 14. In addition, especially in this embodiment, both of the protrusions 2
Since the 6.3° is made of rubber elastic material,
The impact upon contact with the outer cylindrical fitting 14 can be advantageously absorbed and alleviated.

According to the manufacturing method described above, when manufacturing the vibration-proof bushing 10, the viscous fluid is injected into the outer cylindrical metal fitting 14 through the opening of the outer cylindrical metal fitting 14, and Since the fluid storage space 54 filled with the viscous fluid is sealed and completed by reducing the diameter of the outer cylindrical fitting 14, the filling process from injection of the viscous fluid to sealing is extremely difficult. This can be done quickly and easily.

That is, when manufacturing the anti-vibration bushing 10 using such a method, there is no need for assembly operations in fluid, and adhesion of fluid to the product surface can be avoided as much as possible. Anti-vibration bushing 10 after filling with viscous fluid
There is no need to clean the entire surface, fluid can be injected quickly, and special processes such as riveting are not required for sealing. Therefore, according to such a method, the bushing manufacturing process including fluid injection can be performed in a series of continuous steps, which is advantageous in simplifying the manufacturing process and reducing manufacturing costs. This can be achieved by

In addition to these illustrative specific examples, the present invention can be modified in various ways based on the knowledge of those skilled in the art without departing from the spirit thereof. It should also be understood that such embodiments are also included within the scope.

In particular, 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 anti-vibration bushing 10 shown in the above embodiment.

For example, within the fluid accommodation space 54, the narrowing portion 50.52
The first and second elastic projections 26.30 forming the
It is also possible to form it separately from the cylindrical connecting rubber 16, or to form it from a hard material. Furthermore, it is also possible to provide such a working protrusion on the inner circumferential surface side of the outer cylinder fitting 14, or only one of the working protrusions 26, 30 may be provided.

Further, the narrowing portion 50.52 in the fluid accommodation space 54 is formed not by the working protrusion 26.30 as illustrated, but by, for example, expanding the diameter of the inner cylindrical fitting 12 or reducing the diameter of the outer cylindrical fitting 14. By adjusting the distance between the opposing surfaces between the inner and outer cylindrical fittings 12.14, it is also possible to directly form the two fittings 12.14.

Furthermore, in the embodiment described above, the settings were made so that a good vibration damping effect could be exhibited mainly against input vibration in the direction perpendicular to the bushing axis.
Of course, it is also possible to set the vibration damping effect to be effective even against input vibration in the direction of the bush axis based on the viscous resistance of the fluid within the bushing.

In addition, the present invention is applicable to various types of anti-vibration bushings that are interposed between members constituting a vibration transmission system to connect them in a vibration-proof manner, in addition to the vibration-isolating bushings shown in the example. For the various bushings that make up the suspension system,
It can be applied satisfactorily, and it goes without saying that appropriate design changes may be made as appropriate depending on the location of the arrangement and the required vibration damping characteristics.

(Effects of the Invention) As is clear from the above description, according to the manufacturing method according to the present invention, when manufacturing the bunshi 1, the injection of viscous fluid is
This is performed by injection into the outer cylindrical metal fitting through the opening of the outer cylindrical metal fitting, and then by inserting and assembling the bushing body into the outer cylindrical metal fitting, a space filled with viscous fluid is created between them ( A fluid storage chamber) is formed,
Furthermore, since such a space can be sealed (sealed) by reducing the diameter of the outer cylindrical metal fitting and bringing it into close contact with the rigid sleeve that constitutes the bushing body, the viscous fluid injection operation can be performed quickly. At the same time, there is no need for assembly operations in fluid, and there is no need to clean the entire surface of the bush to remove fluid attached to the surface of the bushing. This means that operations can be performed more efficiently.

Therefore, according to the method of the present invention, the manufacturing process can be simplified when manufacturing a viscous fluid-filled bushing that can exhibit excellent vibration damping performance based on the viscous resistance of the viscous fluid sealed inside. Both of this and manufacturing cost reduction can be effectively achieved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an example of a viscous fluid-filled bushing to be manufactured by the method of the present invention, and corresponds to the I-1 cross section in FIG. 3, and FIG. , is a cross-sectional view taken along line ■-■ in FIG. 1 (cross-sectional view taken along line ■-■ in FIG. 3), and FIG. 3 is a right side view in FIG. Further, FIG. 4 is a vertical cross-sectional view showing the bushing main body constituting the anti-vibration bushing shown in FIG.
This is a diagram corresponding to the IV-rV cross section in the figure, and FIG. 5 is a cross-sectional view taken along the line ■-■ in FIG.
(2) sectional view), and FIG. 6 is a right side view in FIG. 4. Moreover, FIG. 7 is a longitudinal sectional view showing the outer cylindrical metal fitting constituting the anti-vibration bushing shown in FIG. The figure is a sectional view taken along ■-■ in Figure 7 (■-■ in Figure 9).
FIG. 9 is a right side view in FIG. 7. Furthermore, FIGS. 10 to 12 respectively show the first
It is an explanatory view for explaining the manufacturing process of the anti-vibration bushing shown in the figure. 18: Push main body 26: First elastic action protrusion 30: Second elastic action protrusion 49: High viscosity fluid 50: First narrowed part 52: Second narrowed part 54: Fluid storage space two metal sleeves

Claims (1)

[Scope of Claims] An inner cylindrical metal fitting in the shape of a cylinder with a bottom, an inner diameter larger than an outer diameter of the inner cylindrical metal fitting, and arranged so as to cover the outer surface of the inner cylindrical metal fitting at a predetermined distance. A bottomed cylindrical outer cylindrical metal fitting is elastically connected by a cylindrical rubber elastic body interposed between the openings thereof, and a predetermined high viscosity fluid is sealed between the inner and outer cylindrical metal fittings. While defining a fluid storage chamber, a narrowed portion expanding in the circumferential direction of the bush or in the direction perpendicular to the axis is formed between opposing surfaces of the cylindrical portions or bottoms of the inner cylindrical fitting and the outer cylindrical fitting in the fluid accommodating chamber. In the method of manufacturing a viscous fluid-filled bushing, the cylindrical rubber elastic body is integrally provided on the outer peripheral surface of the opening side of the inner cylindrical metal fitting, and the cylindrical rubber elastic body is further provided on the outer peripheral surface of the cylindrical rubber elastic body. a step of preparing a bushing body to which a rigid sleeve is fixed; and a step of preparing the outer cylindrical metal fitting, the inner diameter of which is larger at least on the open end side than the outer diameter of the rigid sleeve constituting the bushing body. and a step of injecting a predetermined amount of high viscosity fluid into the inside of the outer cylindrical fitting through the opening while holding the outer cylindrical fitting so as to open vertically upward, and into the outer cylindrical fitting into which the high viscosity fluid is injected. a step of inserting the bush main body into the bush and placing the bush main body and the outer cylindrical fitting in a state in which a space formed between them is filled with a high viscosity fluid; When the main body is inserted, the opening side portion of the outer cylindrical metal fitting is drawn to reduce its diameter and brought into close contact with the outer circumferential surface of the rigid sleeve in the bush main body, thereby ensuring fluid tightness between them. A method of manufacturing a viscous fluid filled bushing, comprising the steps of: completing the fluid storage chamber in which the high viscosity fluid is sealed.