JP2008163992A - Vibration damping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration damping device which suppresses damage by enhancing durability of a stopper part and suitably securing vibration damping property. <P>SOLUTION: The vibration damping device comprises: an inner cylinder 2, an outer cylinder 3 encircling the inner cylinder 2 in axial parallel thereto; a rubber elastomer 4 interposed between the cylinder 2 and outer cylinder 3 to couple both, a pair of hollow parts 5, 6 situated with the inner cylinder 2 sandwiched by the cylinder 2 and outer cylinder 3; and a first stopper 7 which is provided to the hollow part 5, incorporates a rigid intermediate member 9, and protrudes toward the inner cylinder 2 through the outer cylinder 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vibration isolator that includes an inner cylinder, an outer cylinder that surrounds the inner cylinder in an axially parallel manner, and a rubber-like elastic body that connects the two.

  Such an anti-vibration device is used as an anti-vibration rubber bush that suppresses the movement and vibration of an engine or the like, and is used, for example, in an engine mount that supports an automobile engine in an anti-vibration manner. In this type of vibration isolator, in order to reduce the dynamic spring constant in the direction perpendicular to the axis, a pair of cavities are provided between the inner cylinder and the outer cylinder, and the arrangement of the cavities is arranged. In order to restrict an excessive relative displacement of the inner cylinder in the direction, a stopper portion that protrudes from the outer cylinder toward the inner cylinder may be provided in the hollow portion.

  In Patent Documents 1 and 2 below, when a stopper part is formed by a rubber protrusion and a load exceeding a predetermined value is input in the arrangement direction of the cavity part, the stopper part receives the inner cylinder relative to the stopper and acts as a stopper. An anti-vibration device is described. However, in such a vibration isolator, there is a problem that the durability of the stopper portion is reduced due to repeated load input. In particular, depending on the shape of the hollow portion, the volume and the protruding height of the stopper portion may not be increased, and the problem of durability becomes significant. If the stopper portion is damaged, the relative displacement of the inner cylinder is not properly regulated, and the vibration isolation characteristics are affected.

Patent Document 3 listed below describes a vibration isolator in which an intermediate plate is embedded in a rubber-like elastic body that supports an inner cylinder from a direction orthogonal to the arrangement direction of the hollow portions. However, this vibration isolator has an intermediate plate embedded for the purpose of increasing the dynamic spring constant in the direction orthogonal to the arrangement direction of the hollow portions, and does not disclose any structure for improving the durability of the stopper portion.
JP-A-6-147245 JP 2000-346134 A JP 2005-30599 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vibration isolator capable of suppressing the damage by increasing the durability of the stopper portion and appropriately ensuring the vibration isolating characteristics. is there.

  The above object can be achieved by the present invention as described below. That is, the vibration isolator according to the present invention includes an inner cylinder, an outer cylinder that surrounds the inner cylinder in an axial parallel manner, a rubber-like elastic body that is interposed between the inner cylinder and the outer cylinder, and connects the two. A pair of cavities positioned between the inner cylinder and the outer cylinder with the inner cylinder interposed therebetween, and provided in at least one of the cavities, including a rigid intermediate member and from the outer cylinder And a first stopper portion protruding toward the inner cylinder.

  According to the vibration isolator of the present invention, the first protruding from the outer cylinder toward the inner cylinder is at least one of the pair of cavities positioned with the inner cylinder sandwiched between the inner cylinder and the outer cylinder. Since the stopper portion is provided and the first stopper portion incorporates a rigid intermediate member, durability can be improved and damage can be suppressed without increasing the protruding height or volume of the first stopper portion. . As a result, when a predetermined load or more is input in the direction in which the hollow portions are arranged, excessive relative displacement between the inner cylinder and the outer cylinder can be appropriately regulated to ensure vibration isolation characteristics.

  In the above, the intermediate member has an outer peripheral surface that contacts the inner peripheral surface of the outer cylinder, an inner peripheral surface covered with a thin rubber film, and a through hole that reaches the outer peripheral surface from the inner peripheral surface. The first stopper part includes the rubber film that covers the inner peripheral surface of the intermediate member and faces the cavity part, and the columnar rubber provided in the through hole. It is preferable that one end is integrally connected to the rubber film and the other end of the columnar rubber is vulcanized and bonded to the inner peripheral surface of the outer cylinder.

  In the above configuration, the outer peripheral surface of the intermediate member abuts along the inner peripheral surface of the outer cylinder, and the inner peripheral surface of the intermediate member is covered with a thin rubber film, and the rubber film faces the cavity portion. Therefore, the rigid intermediate member occupies most of the first stopper portion in the radial direction. From this, the durability of the first stopper portion can be improved more suitably, the damage can be suppressed, and the anti-vibration characteristics can be ensured.

  However, since the rigid intermediate member occupies most of the first stopper portion, it becomes difficult to stably support the intermediate member, and the intermediate member is displaced when the outer cylinder is press-fitted into a mounting hole such as a bracket. May cause problems such as Therefore, in the above configuration of the present invention, columnar rubber is provided in the through hole of the intermediate member, and one end thereof is integrally connected to the rubber film, and the other end is vulcanized and bonded to the inner peripheral surface of the outer cylinder, Thereby, the relative position of the intermediate member in the first stopper portion can be appropriately and stably fixed.

  In the above, a step is formed in a state in which a step is exposed at the axial end portion of the intermediate member, and a notch groove for exposing the inner peripheral surface of the intermediate member is formed at the axial end portion of the rubber film. Those are preferred.

  When the intermediate member has an outer peripheral surface that is in contact with the inner peripheral surface of the outer cylinder and an inner peripheral surface that is covered with a thin rubber film, in the formation of the vibration isolator, the intermediate member in the mold It is necessary to perform positioning and support fixing at the end in the axial direction. Therefore, in the above configuration of the present invention, a step is formed in a state where the step is exposed at the axial end portion of the intermediate member, and a notch groove is formed at the axial end portion of the rubber film to expose the inner peripheral surface of the intermediate member. Thus, the engaging portion provided in the mold can be engaged with a step or notch groove forming position so that the intermediate member can be properly positioned and supported and fixed.

  In the above, one of the pair of hollow portions is provided with the first stopper portion, and the other is provided with a second stopper portion, and the first stopper portion is more rubber-like than the second stopper portion. And a pair of rubber protrusions projecting from the outer cylinder toward the inner cylinder, and the rubber between the pair of rubber protrusions. It is preferable to have a pair of concave grooves formed adjacent to the projections and a connecting wall having a projection height smaller than that of the rubber projection and connecting the pair of concave grooves.

  In the above configuration, the first stopper portion is closer to the rubber-like elastic body than the second stopper portion, which may make it difficult to secure the protruding height and volume of the first stopper portion. Since the durability of the stopper portion is enhanced as described above, no particular problem occurs. Moreover, in the second stopper portion, when the excessive relative displacement between the inner cylinder and the outer cylinder is restricted, the pair of rubber protrusions serve as a stopper, so that the load input to the second stopper portion can be dispersed. Furthermore, since the pair of concave grooves are formed adjacent to the rubber protrusions, it is possible to prevent the pressed rubber protrusions from escaping in the circumferential direction and the dynamic spring constant from becoming excessive.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing an example of a vibration isolator according to the present invention and shows a no-load state that is not assembled to a vehicle. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 3 is a cross-sectional view taken along line BB in FIG. FIG. 4 is an enlarged view of a main part of FIG. 5 is a cross-sectional view taken along the line CC in FIG.

  As shown in FIG. 1, the vibration isolator 1 of the present embodiment is interposed between an inner cylinder 2, an outer cylinder 3 that surrounds the inner cylinder 2 in an axially parallel manner, and an inner cylinder 2 and an outer cylinder 3. A pair of cavities that are positioned between the inner cylinder 2 and the outer cylinder 3 with the rubber-like elastic body 4 and the inner cylinder 2 and the outer cylinder 3 interposed therebetween, and extend in the circumferential direction while extending in the axial direction AD. Parts 5, 6, a first stopper part 7 provided in the cavity part 5, and a second stopper part 8 provided in the cavity part 6.

  The vibration isolator 1 has a function of suppressing vibration transmitted from the engine to the vehicle body side by connecting the engine as a vibration generation source and the vehicle body as the support body in a vibration-proof manner. The inner cylinder 2 has an insertion hole 21 extending in the axial direction, and is attached to one of the engine side and the vehicle body side via a shaft member inserted therethrough. The outer cylinder 3 is press-fitted and fixed in an attachment hole such as a bracket, and is attached to the other of the engine side and the vehicle body side via the bracket. The inner cylinder 2 and the outer cylinder 3 can be formed of a known high-rigidity material such as a steel material or a high-rigidity resin material.

  The rubber-like elastic body 4 is disposed between the pair of cavities 5 and 6 and is vulcanized and bonded to the inner peripheral surface of the outer cylinder 3 and the outer peripheral surface of the inner cylinder 2. The side surfaces 41 and 42 of the rubber-like elastic body 4 constitute a part of the inner peripheral surfaces of the hollow portions 5 and 6, respectively, and are curved so as to protrude toward the first stopper portion 7. The inner cylinder 2 is supported in the state offset from the axial center to the first stopper portion 7 side.

  As shown in FIGS. 2 and 3, the rubber-like elastic body 4 extends from the outer cylinder 3 toward the inner cylinder 2 by gradually increasing the length in the axial direction AD, and slightly increases the axial AD end of the inner cylinder 2. It is provided to be exposed. The inner cylinder 2 is elastically supported by the rubber-like elastic body 4, and when a vibration having a relatively small amplitude is input, the vibration-proof effect is exhibited by the bending of the rubber-like elastic body 4. As the rubber-like elastic body 4, a known rubber material in the technical field of vibration-proof rubber for automobiles can be used without limitation.

  The first stopper portion 7 provided in the cavity portion 5 is closer to the rubber-like elastic body 4 than the second stopper portion 8 provided in the cavity portion 6 in an unloaded state. The first stopper portion 7 and the second stopper portion 8 regulate excessive relative displacement between the inner cylinder 2 and the outer cylinder 3 in the arrangement direction of the cavities 5 and 6 (in the direction perpendicular to the axis in the vertical direction in FIG. 1), respectively. It has the function to do.

  The first stopper portion 7 incorporates a rigid intermediate member 9 and projects from the outer cylinder 3 toward the inner cylinder 2. When the relative displacement between the inner cylinder 2 and the outer cylinder 3 is restricted, the first stopper portion 7 is rubbery. The side surface 41 of the elastic body 4 is received and a stopper function is achieved. The intermediate member 9 can be formed of a known rigid material. Specifically, a metal material such as steel or a high-rigidity resin material can be used. However, the intermediate member 9 is made of resin from the viewpoint of reducing the weight of the vibration isolator 1. Preferably there is.

  As shown in FIGS. 2, 4, and 5, the intermediate member 9 includes an outer peripheral surface 91 that is in contact with the inner peripheral surface of the outer cylinder 3, an inner peripheral surface 92 that is covered with a thin rubber film 71, and an inner peripheral surface And a through hole 93 extending in a radial direction from the surface 92 and reaching the outer peripheral surface 91. The through hole 93 is provided in a columnar shape at the center in the axial direction of the intermediate member 9. In addition, the outer peripheral surface 91 of the intermediate member 9 is only in contact with the inner peripheral surface of the outer cylinder 3 and is not subjected to an adhesion process.

  The first stopper portion 7 includes, in addition to the intermediate member 9, a rubber film 71 that covers the inner peripheral surface 92 of the intermediate member 9 and faces the cavity portion 5, and a columnar rubber provided in the through hole 93 of the intermediate member 9. 72. One end 72 a of the columnar rubber 72 is integrally connected to the rubber film 71, and the other end 72 b is vulcanized and bonded to the inner peripheral surface of the outer cylinder 3. Therefore, the relative position of the intermediate member 9 in the first stopper portion 7 is appropriately fixed, and the intermediate member 9 can be prevented from being displaced when the outer cylinder 3 is press-fitted into a mounting hole such as a bracket.

  Since the first stopper portion 7 incorporates the rigid intermediate member 9 as described above, durability can be improved and damage can be suppressed without increasing the protruding height or volume. The characteristics can be suitably secured. In particular, when the rubber-like elastic body 4 bulges toward the first stopper portion 7 as in the present embodiment, the rubber-like elastic body 4 and the first stopper portion 7 come close to each other and the first stopper Since it becomes difficult to secure the protruding height and volume of the portion 7, it is useful to improve the durability by the above configuration.

  In the present embodiment, the rigid intermediate member 9 occupies most of the first stopper portion 7 in the radial direction, whereby the durability of the first stopper portion 7 becomes more excellent. On the other hand, it is difficult to support and fix the intermediate member 9, but in this embodiment, the intermediate member 9 is stably supported and fixed from the inside by providing the rubber film 71 and the columnar rubber 72 as described above. Can do.

  The first stopper portion 7 has less elastic deformation than the case where the entire portion is made of rubber. However, in this embodiment, the cavity 5 side portion of the rubber-like elastic body 4 facing the first stopper portion 7 is the first stopper portion 7. When the first stopper portion 7 performs a stopper action, a sufficient amount of rubber is secured between the inner cylinder 2 and the first stopper portion 7. It is possible to prevent the dynamic spring constant from rapidly increasing.

  A step 94 having a relatively large axial length of the inner peripheral surface 92 side portion is formed at the end of the intermediate member 9 in the axial direction AD. The step 94 is exposed without being covered with rubber on one side in the axial direction AD on the left side of FIG. In addition, a notch groove 73 that partially exposes the inner peripheral surface 92 of the intermediate member 9 is formed at the end in the axial direction AD of the rubber film 71. As shown in FIGS. 4 and 5, the notch grooves 73 are formed as a pair on both sides of the axial direction AD with a gap in the circumferential direction. The groove wall of the cutout groove 73 is inclined so that the thickness of the rubber film 71 gradually decreases toward the inner peripheral surface 92 of the intermediate member 9 from the viewpoint of suppressing the peeling of the rubber film 71.

  The vibration isolator 1 sets the inner cylinder 2, the outer cylinder 3 and the intermediate member 9 in the mold, and then supplies the unvulcanized rubber composition to the cavity formed in the mold in a clamped state. Molded by applying heat and pressure for a certain period of time and vulcanizing. In the present embodiment, the outer peripheral surface 91 of the intermediate member 9 abuts along the inner peripheral surface of the outer cylinder 3, and the inner peripheral surface 92 is covered with the thin rubber film 71. It is necessary to position and support and fix the member 9 at the axial AD end.

  Therefore, in the present embodiment, the engaging portion provided in the mold is engaged with the formation position of the step 94 and the notch groove 73 of the intermediate member 9, thereby appropriately positioning and supporting and fixing the intermediate member 9. It is configured as follows. If the intermediate member 9 is not properly positioned in the mold, the rubber film 71 is not properly formed, and the exposed portion of the intermediate member 9 abuts against the side surface 41 of the rubber-like elastic body 4. There is a risk that durability will be reduced.

  The outer peripheral surface 91 of the intermediate member 9 does not need to be in close contact with the inner peripheral surface of the outer cylinder 3, and rubber may enter the gap between them. In the first place, since the outer cylinder 3 reduced in diameter by drawing is press-fitted and fixed to the mounting hole of the bracket or the like, the outer peripheral surface 91 of the intermediate member 9 is formed in the inner cylinder 3 when the vibration isolator 1 is formed. The radius of curvature is slightly smaller than the peripheral surface.

  As shown in FIG. 1, the second stopper portion 8 is arranged between the pair of rubber projections 81 and the pair of rubber projections 81 that are arranged at intervals in the circumferential direction and project from the outer cylinder 3 toward the inner cylinder 2. A pair of recessed grooves 82 formed and a connecting wall 83 that connects the pair of recessed grooves 82 to each other are provided. The pair of concave grooves 82 are adjacent to the rubber protrusions 81 with the groove bottoms each having an arc shape, and the connecting wall 83 connecting them has a protrusion height smaller than that of the rubber protrusions 81.

  In the second stopper portion 8, when restricting excessive relative displacement between the inner cylinder 2 and the outer cylinder 3, the pair of rubber protrusions 81 receives the side surface 42 of the rubber-like elastic body 4 and performs a stopper function. At this time, the pressed rubber protrusion 81 can easily escape to the circumferential concave groove 82 side, and an excessive dynamic spring constant can be suppressed. Furthermore, by providing a stopper action with the pair of rubber protrusions 81, it is possible to disperse the load input to the second stopper portion 8 and improve the durability.

  The present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the spirit of the present invention, and the characteristics of the rubber-like elastic body and the shape of the hollow portion are used. It can change suitably according to a use or conditions.

The top view which shows an example of the vibration isolator which concerns on this invention AA arrow sectional view of FIG. BB arrow sectional view of FIG. 1 is an enlarged view of the main part CC sectional view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vibration isolator 2 Inner cylinder 3 Outer cylinder 4 Rubber-like elastic body 5 Cavity part 6 Cavity part 7 First stopper part 8 Second stopper part 9 Intermediate member 71 Rubber film 72 Columnar rubber 72a One end 72b of columnar rubber Other than columnar rubber End 73 Notch groove 81 Rubber projection 82 Concave groove 83 Connecting wall 91 Outer peripheral surface 92 of intermediate member Inner peripheral surface 93 of intermediate member Through hole 94 Step AD Axial direction

Claims (4)

An inner cylinder,
An outer cylinder surrounding the inner cylinder in parallel with the axis;
A rubber-like elastic body that is interposed between the inner cylinder and the outer cylinder and connects the two;
A pair of cavities positioned across the inner cylinder between the inner cylinder and the outer cylinder;
An anti-vibration device comprising: a first stopper portion provided in at least one of the hollow portions, including a rigid intermediate member, and protruding from the outer cylinder toward the inner cylinder. The intermediate member includes an outer peripheral surface that abuts along the inner peripheral surface of the outer cylinder, an inner peripheral surface covered with a thin rubber film, and a through hole that reaches the outer peripheral surface from the inner peripheral surface,
The first stopper portion includes the rubber film that covers the inner peripheral surface of the intermediate member and faces the cavity portion, and a columnar rubber provided in the through hole,
The vibration isolator according to claim 1, wherein one end of the columnar rubber is integrally connected to the rubber film, and the other end of the columnar rubber is vulcanized and bonded to the inner peripheral surface of the outer cylinder.   The notch groove which exposes the internal peripheral surface of the said intermediate member is formed in the axial direction edge part of the said rubber film while the level | step difference is exposed in the axial direction edge part of the said intermediate member. The vibration isolator described in 1. The first stopper portion is provided in one of the pair of hollow portions, and the second stopper portion is provided in the other,
The first stopper portion is closer to the rubber-like elastic body than the second stopper portion;
The second stopper portions are arranged at intervals in the circumferential direction, and are formed adjacent to the rubber projections between the pair of rubber projections and a pair of rubber projections protruding from the outer cylinder toward the inner cylinder. The anti-vibration device according to any one of claims 1 to 3, further comprising: a pair of concave grooves and a connecting wall that has a projection height smaller than that of the rubber protrusion and connects the pair of concave grooves.

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