JP2827859B2 - Liquid-filled bush - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-filled bush which is used for a suspension bush of an automobile and exhibits a vibration-proof effect based on a flow action of a liquid sealed therein, and more particularly to a relative bush between connected members. The present invention relates to a liquid-filled bush provided with a stopper mechanism for limiting a displacement amount.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Application Laid-Open No. 56-164242 and Japanese Patent Application Laid-Open No. 3-201337 disclose a type of vibration isolator which is interposed between two connected members and is connected by vibration isolation. As described above, an inner cylindrical fitting to which one connected member is attached and an outer cylindrical fitting to which the other connected member is attached are arranged at a predetermined distance in a radial direction, and the inner and outer cylindrical fittings are arranged in a radial direction. While connecting with a rubber elastic body interposed between the opposing surfaces, a liquid storage portion in which a predetermined liquid is sealed is formed between the inner and outer cylindrical fittings, and a fluid that flows in the liquid storage portion at the time of vibration input is formed. 2. Description of the Related Art There is known a liquid-filled bush in which an anti-vibration effect is obtained based on a flow action (such as a shearing action or a liquid column resonance action).

[0003] Such a bush is suitably used for a suspension bush of an automobile or the like. However, as disclosed in the above-mentioned publication, the relative displacement between connected members when a large vibration load is input. For the purpose of restricting the rubber elastic body or preventing excessive deformation of the rubber elastic body, generally, it protrudes radially outward from the inner cylinder fitting side in the liquid storage portion and is predetermined in the radial direction with respect to the outer cylinder fitting. A stopper member is used which is opposed at a distance and limits the relative displacement of the inner and outer cylinders by contact with the outer cylinder.

However, it is troublesome to form such a stopper member as a separate member and dispose the stopper member in the liquid container, and there is a problem that assembly workability is poor.

Further, in the liquid-filled bush, as shown in the above-mentioned publication, generally, a metal sleeve is vulcanized and bonded to the outer peripheral surface of a rubber elastic body, and is formed on the metal sleeve. A pocket portion opened to the outer peripheral surface through the window portion is formed of a rubber elastic body, and a liquid storage portion is formed by externally fitting and fixing an outer cylinder fitting to the metal sleeve and covering the opening of the pocket portion. In order to prevent the outer sleeve from coming off the metal sleeve, the outer sleeve is partially recessed radially inward after the outer sleeve is assembled, so that There is a case where a process of intruding is performed.

However, when such a process is performed, it is inevitable that a gap is formed between the recessed portion of the outer cylinder and the connected member attached to the outer peripheral surface of the outer cylinder. Since the stopper member comes into contact with the depressed portion, there was a problem that the contact portion (recess portion) of the outer cylinder fitting was easily deformed by the contact of the stopper member. The deformation of the rubber elastic body when a large vibration load is input because the deformation of the abutment part of the fitting gradually increases the distance between the radially opposed surfaces of the stopper member and the outer cylindrical fitting and the effective stopper function is not exhibited. Therefore, there is also a problem that the durability becomes large and the durability is reduced.

[0007]

Here, the present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to solve the above problem without using any special member, without using a special member. It is an object of the present invention to provide a liquid-filled bush to which a radial stopper function for limiting a relative displacement amount of the bush can be advantageously provided.

Further, the present invention provides a liquid-filled bush provided with a radial stopper portion in which the strength of a portion constituting a stopper mechanism can be advantageously secured and a stable stopper function is exhibited for a long period of time. The purpose is to provide.

Still further, the present invention provides a radial stopper function for limiting the relative displacement amount of the inner and outer cylinders in the radial direction without requiring any special member, and the relative displacement of the inner and outer cylinders in the axial direction. It is also an object to provide a liquid-filled bush that can advantageously also be provided with an axial stopper function for limiting the amount.

[0010]

In order to solve such a problem, a feature of the present invention is that one of the members to be connected to be connected in vibration isolation is connected to an inner cylindrical fitting to which the other member to be connected is attached. An outer cylinder fitting to which the connecting member is attached, arranged at a predetermined distance in the radial direction from each other, and connected by a rubber elastic body interposed between the radially opposed surfaces of the inner cylinder fitting and the outer cylinder fitting; A liquid-containing bush in which a liquid is enclosed between the inner cylinder and the outer cylinder in which a liquid is enclosed and a liquid flow is generated at the time of vibration input; Is extended in the axial direction, and the extended portion is bent radially inward in at least a part of the circumferential direction, so that the end portion is radially predetermined with respect to the inner cylinder fitting or the one connected member. The inner cylinder is located at a distance Immediately or in the provision of the radial stopper portion for limiting the relative displacement of the radial direction with respect to the outer tubular member of the inner cylindrical member according by abutment against one of the member to be connected the.

The present invention also relates to such a liquid-filled bush, wherein the inner cylindrical metal fitting or the one of the outer cylindrical metal fittings protrudes radially inward at an axial end portion of the extended portion of the outer cylindrical metal fitting. An axial relative displacement amount of the inner cylindrical member with respect to the outer cylindrical member by being opposed to the connected member at a predetermined distance in the axial direction and abutting against the inner cylindrical member or the one connected member. The present invention is also characterized in that it is provided with an axial stopper for limiting the pressure.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 and 2 show a compression rod bush 10 interposed in a mounting portion of a front lower arm of an automobile to a vehicle body as one embodiment of the present invention. The bush 10 includes a main rubber elastic body 1 in which an inner cylinder fitting 12 and an outer cylinder fitting 14 arranged at a predetermined radial distance from each other are interposed therebetween.
6, and is elastically connected.
As shown by the phantom line in FIG. 1, the rod portion 18 of the front lower arm is press-fitted and fixed to the inner cylinder fitting 12, and the vehicle body side bracket 20 is externally fixed to the outer cylinder fitting 14. As a result, the front lower arm is interposed at a portion where the front lower arm is attached to the vehicle body.

More specifically, the inner cylindrical fitting 12 has a bottomed cylindrical shape whose opening-side end is slightly enlarged outward. Further, an air vent hole 24 is provided in the bottom wall portion 22 of the inner cylinder fitting 12.

A cylindrical metal sleeve 30 is disposed radially outward of the inner cylindrical fitting 12 and substantially coaxially at a predetermined distance in the radial direction. This metal sleeve 3
Reference numeral 0 denotes a position in which the length in the axial direction is shorter than that of the inner cylinder fitting 12, and the end of the inner cylinder fitting 12 on the bottom wall 22 side projects from the axial end of the metal sleeve 30 by a predetermined length in the axial direction. It has been impatient. Further, the metal sleeve 30 is formed with a pair of opening windows 32, 32, which extend in the circumferential direction with a length of less than half a circumference, at portions opposed to each other in one radial direction.

A rubber elastic body 16 is interposed between the inner cylindrical fitting 12 and the radially opposed surfaces of the metal sleeve 30, and the inner rubber fitting 16 is provided by the main rubber elastic body 16.
2 and a metal sleeve 30 are formed as an integral vulcanized molded product elastically connected. Note that a thin cushion rubber layer 3 is provided on the outer peripheral surface of the cylindrical wall portion 26 and the outer surface of the bottom wall portion 22 of the inner cylindrical fitting 12 protruding from the axial end of the metal sleeve 30.
4, 36 are formed integrally with the main rubber elastic body 16, respectively. Further, the main rubber elastic body 16 is used for the inner cylindrical fitting 1.
The rubber layer 38 is formed on the inner peripheral surface of the inner cylinder 12 so as to relieve the stress when the rod portion 18 is pressed into the inner peripheral surface. The rubber layer 38 has a plurality of grooves 40 extending in the axial direction.

Further, the main rubber elastic body 16 is formed with an annular pocket portion 42 extending continuously in the circumferential direction. The pocket portion 42 is provided in the metal sleeve 30.
Are formed in the outer peripheral surface through the opening windows 32, 32, and in the portion of the metal sleeve 30 where the opening windows 32 are not formed, the openings are formed with a tunnel-like structure. Have been. In the pocket portion 42, an operation protrusion 44 projecting outward from the bottom at a predetermined height is formed by the main rubber elastic body 16 in a substantially annular shape continuous in the circumferential direction.

Then, with respect to the integrally vulcanized molded product having such a structure, the outer cylindrical metal fitting 14 having a large diameter and a bottomed cylindrical shape as a whole is moved outward from the bottom wall 22 side of the inner cylindrical metal fitting 12. It is inserted and fixed to the outer peripheral surface of the metal sleeve 30. A bottom wall portion 48 is provided on the cylindrical wall portion 46 of the outer tube fitting 14.
A step portion 50 is formed so as to be deviated to the side, and the bottom wall portion 48 is formed.
Side is a small-diameter portion 52, while the opening side is a large-diameter portion 5.
It is set to 4. The large-diameter portion 54 is formed of the metal sleeve 3.
The length in the axial direction is slightly longer than 0. The large-diameter portion 54 is extrapolated into the metal sleeve 30 and subjected to a diameter reduction process such as an octagonal drawing so that the large-diameter portion 54 is fitted to the outer peripheral surface of the metal sleeve 30. Fixed. A seal rubber layer 55 is formed on the inner peripheral surface of the large-diameter portion 54, and an air vent hole 57 is formed in the bottom wall portion 48.

The axial end portions 56, 5 of the large diameter portion 54
6 is not diameter-reduced and has a slightly larger diameter,
The vehicle body-side bracket 20 is fitted and fixed to the outer peripheral surfaces of these axial end portions 56, 56. Thereby, the influence of the fitting force exerted on the outer cylinder fitting 14 when the vehicle body side bracket 20 is attached to the metal sleeve 30 side is reduced or prevented.

The large-diameter portion 54 of the outer sleeve 14 is further reduced in diameter in a central portion 58 in the axial direction, so that the large-diameter portion 54 is recessed toward the opening window 32 of the metal sleeve 30.
The metal sleeve 30 is also deformed and depressed in a portion where is not formed. Thereby, the outer tube fitting 14
Are locked to the metal sleeve 30 to prevent the shaft from coming off in the axial direction.

The opening windows 32, 32 of the metal sleeve 30 are fluid-tightly covered by assembling the outer tube fitting 14, so that a predetermined viscous fluid is sealed in the pocket portion 42. An annular fluid chamber 60 is formed as a liquid storage portion extending in the circumferential direction between 12 and 14. The viscous fluid sealed in the fluid chamber 60 has a viscosity of 1 to 1 in order to obtain an effective vibration damping effect.
One having a pressure of 00 Pa · s is suitably used, for example, silicone oil or the like. Also, the encapsulation of such a fluid
Although it is possible to assemble the outer cylinder fitting 14 to the integrally vulcanized molded product in a fluid or the like, after assembling the outer cylinder fitting 14, a fluid is injected through an injection hole 62 formed in the outer cylinder fitting 14. After filling, the injection hole 62 is inserted into the rivet 64.
If it seals with, it can avoid adhesion of a viscous fluid to the surface.

The fluid chamber 60 thus formed is
It is narrowed by an action projection 44 formed inside. Therefore, an effective shearing force is generated in the fluid that is caused to flow in the fluid chamber 60 at the time of radial and axial vibration input between the inner and outer cylinder fittings 12 and 14, and a vibration damping effect is exhibited. is there.

Further, the outer tube fitting 14 has a step 50
Are projected radially inward toward the inner cylinder 12, and the small-diameter portion 52 is opposed to the inner cylinder 12 at a predetermined distance in the radial direction. The small-diameter portion 52 and the cylindrical wall portion 26 of the inner cylindrical metal member 12 opposed to the small-diameter portion 52 abut against each other via the cushioning rubber layer 34, so that the relative displacement of the inner and outer cylindrical metal members 12, 14 in the radial direction. A radial stopper mechanism for limiting the amount is configured. As is apparent from this, in the present embodiment, the step portion 50 and the small-diameter portion 52 of the outer tube fitting 14 are provided.
Constitutes an extension portion, and the small-diameter portion 52 constitutes a radial stopper portion.

The bottom wall 48 of the outer cylinder 14 is opposed to the bottom wall 22 of the inner cylinder 12 at a predetermined distance in the axial direction. The bottom wall portions 22 and 4 of the inner and outer cylindrical fittings 12 and 14 facing each other are provided.
8, an axial stopper mechanism for limiting the relative displacement of the inner and outer cylindrical fittings 12 and 14 in the axial direction by mutual contact via the buffer rubber layer 36 is formed. As is apparent from this, in the present embodiment, the bottom wall portion 48 of the outer tube fitting 14 forms an axial stopper portion.

Further, the large diameter portion 54 of the outer cylinder fitting 14
The outer peripheral surfaces of the axial end portions 56, 56, the outer peripheral surface of the small-diameter portion 52, and the outer surface of the bottom wall portion 48 are respectively provided with mounting rubber 6.
6 is vulcanized and formed into an outer peripheral surface shape corresponding to the vehicle body side bracket 20 to be attached.
The small-diameter portion 52 and the bottom wall portion 48 of the outer metal fitting 14 are held in contact with the vehicle-body-side bracket 20 via the mounting rubber 66, whereby the small-diameter portions 52 constituting the stopper portion are provided. In addition, the rigidity of the bottom wall portion 48 is improved and deformation is prevented.

Therefore, in the compression rod bush 10 structured as described above, the inner cylindrical fitting 12
Since the stopper portion for limiting the relative displacement amount of the inner and outer cylindrical fittings 12 and 14 in the radial direction by contact with the outer cylindrical fitting 14 is formed integrally with the outer cylindrical fitting 14, no special stopper member is required, and the structure is reduced. Simplification and ease of assembly can be advantageously achieved.

Moreover, in such a bush 10,
Since the stopper portion is formed outside the fluid chamber 60,
The fluid chamber 60 is deformed by the deformation of the member due to the contact of the stopper.
The fluid tightness is not impaired.

The outer tube fitting 14 constituting the stopper portion
The small-diameter portion 52 has the strength (deformation rigidity) of the step portion 50.
Since the reinforcing effect of the present invention can be advantageously secured, excellent durability is exhibited, and the effect of limiting the effective displacement can be stably exhibited over a long period of time. Can also be improved in durability. In addition, in the present embodiment, in particular, since the outer cylindrical metal fitting 14 having a bottomed cylindrical shape is employed, the small-diameter portion 5 constituting the radial stopper portion is also formed by the bottom wall portion 48.
2 will be exerted a reinforcing effect.

Further, in the compression rod bush 10 of this embodiment, the outer cylinder 14 is also provided with a stopper for limiting the relative displacement of the inner and outer cylinders 12 and 14 in the axial direction by abutting the inner cylinder 12. Since they are integrally formed, the axial stopper mechanism can be advantageously realized with a simple structure.

In the bush 10 according to the present embodiment, the small-diameter portion 52 and the bottom wall portion 48 of the outer cylindrical member 14 constituting the radial and axial stopper mechanisms are all provided with:
Since it is reinforced and supported by the vehicle body side bracket 20 via the mounting rubber 66, the durability of the stopper portion in the radial direction and the axial direction can be further improved, and the effective displacement amount can be limited. The effect can be exhibited stably over a longer period.

Although the embodiment of the present invention has been described in detail, this is a literal example, and the present invention is not construed as being limited to such a specific example.

For example, the specific configuration of the liquid container is not limited to the fluid chamber 60 of the above-described embodiment, but should be appropriately changed according to the vibration-proof characteristics required of the bush. is there. Specifically, for example, an orifice in which a low-viscosity fluid having a viscosity of 1 Pa · s or less, preferably 0.1 Pa · s or less, such as water, an alkylene glycol, or a polyalkylene glycol, is sealed as a liquid container. A plurality of fluid chambers and the like interconnected by passages may also be advantageously employed.

When a low-viscosity fluid is used, the working projection 44 in the fluid chamber 60 is not always necessary. However, by forming the operation protrusion 44 from a rubber elastic body, the operation protrusion 44 can exert a buffering effect when the stopper mechanism exerts the effect of restricting the displacement of the inner and outer cylinder fittings. Is also possible.

Furthermore, in the above embodiment, the outer tube fitting 14
The diameter of one end in the axial direction is reduced over the entire circumference in the circumferential direction, so that the small diameter portion 52 that constitutes the radial stopper portion is formed. By radially projecting radially inward at a predetermined width at a single or a plurality of locations in the circumferential direction, a radial stopper portion can be formed. If such stoppers are employed, a vertical wall having a reinforcing effect can be formed on both circumferential sides of each stopper, so that the stopper can be made even more rigid.

Further, in the above-described embodiment, the inner cylindrical fitting 12 has a bottomed cylindrical shape, and the stopper formed on the outer cylindrical fitting 14 is in contact with the cylindrical wall 26 and the bottom wall 22. The inner cylinder 12 has a cylindrical shape, and the rod portion 1 attached to the inner cylinder 12 has been described.
It is also possible to make the stopper portion abut against 8, for example.

Further, in the above-described embodiment, the outer tube fitting 14 is formed in a cylindrical shape with a bottom, and the bottom wall portion 48 forms an axial stopper portion. However, such an axial stopper portion is not necessarily formed. It is not necessary to use a cylindrical outer cylinder fitting.

In addition, in the above-described embodiment, a specific example in which the present invention is applied to a compression rod bush for an automobile is shown. However, the present invention is also applicable to a suspension bush and a mount for an automobile, or various types other than an automobile. Of course, any of these can be advantageously applied to the vibration isolating bush.

In addition, although not enumerated one by one, the present invention can be embodied in modes in which various changes, modifications, improvements, and the like are made based on the knowledge of those skilled in the art. It goes without saying that all of them are included in the scope of the present invention unless departing from the spirit of the present invention.

[0039]

As is apparent from the above description, in the liquid-filled bush having the structure according to the present invention, the inner and outer cylinders are brought into contact with each other by the inner cylinder and the connected member attached thereto. Since the radial stopper for limiting the amount of dynamic displacement is formed integrally with the outer cylinder by an extension of the outer cylinder, a special stopper member is not required, which simplifies the structure and facilitates assembly. And the like can be advantageously achieved.

Also, in such a liquid-filled bush, since the stopper mechanism in the radial direction is formed outside the liquid storage portion, the liquid storage bushing is deformed even if the outer cylindrical fitting is deformed by the contact of the stopper portion. The fluid tightness of the portion is not impaired, and the extension of the outer cylindrical member constituting the radial stopper has an effect of improving the strength by the portion bent inward in the radial direction. Therefore, the effect of limiting the effective displacement can be stably exhibited over a long period of time.

In the liquid-filled bush having the structure according to the second aspect of the present invention, the amount of relative displacement of the inner and outer cylinders in the axial direction due to the abutment on the inner cylinder and the connected member attached thereto. Is also integrally formed with the outer cylinder, so that the axial stopper mechanism can be advantageously realized with a simple structure.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing a compression rod bush as one embodiment of the present invention, and is a view corresponding to a II section in FIG. 2;

FIG. 2 is a sectional view taken along the line II-II in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 compression rod bush 12 inner cylinder 14 outer cylinder 16 body rubber elastic body 18 rod 20 body side bracket 22 bottom wall 26 cylinder wall 30 metal sleeve 32 opening window 46 cylinder wall 48 bottom wall 50 step 52 Small diameter part 54 Large diameter part 60 Fluid chamber

Continuation of front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F16F 13/00

Claims (2)

(57) [Claims] 1. An inner cylindrical fitting to which one connected member to be vibration-proof connected is mounted and an outer cylindrical fitting to which the other connected member to be vibration-proof connected are separated by a predetermined distance in the radial direction. A liquid storage portion which is connected and connected by a rubber elastic body interposed between the radially opposed surfaces of the inner and outer cylindrical fittings, and in which liquid is sealed therein to generate a liquid flow at the time of vibration input. A liquid-filled bush formed between the inner cylinder and the outer cylinder, wherein one end in the axial direction of the outer cylinder is extended in the axial direction, and the extended portion is at least one end in the circumferential direction. By being bent inward in the radial direction at the portion, it is located at a predetermined radial distance from the inner cylindrical fitting or the one connected member with respect to the inner cylindrical fitting or the one connected member. Of the inner cylinder fitting Fluid-filled bushing, characterized in that a radial stop that limits the relative displacement of the radial direction with respect to cylindrical member. 2. An axially distal end portion of the extension portion of the outer cylindrical member, which protrudes radially inward and is opposed to the inner cylindrical member or the one connected member at a predetermined distance in the axial direction. An axial stopper portion for limiting an axial relative displacement amount of the inner cylindrical member with respect to the outer cylindrical member by contact with the inner cylindrical member or the one connected member. The liquid-filled bush according to claim 1.