JP2010084911A - Vibration control bush - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a removal preventing effect of an inner cylinder from an outer cylinder while reducing weight. <P>SOLUTION: This vibration control bush 10 connecting the inner cylinder 12 and the outer cylinder 14 through a vibration control base body 16 formed of a rubber elastic body is provided with an enlarged diameter part 18 projected radially outward Ko, at one end in the axial direction X of the inner cylinder 12. The outer cylinder 14 formed in cylinder shape gradually reduced in wall thickness from one end 14A toward the other end 14B in the axial direction X by drawing is formed with an inner bent part 22 with an inner diameter ϕ1 smaller than the outer diameter ϕ2 of the enlarged diameter part 18 by bending one end 14A on the thick wall side radially inward Ki, and an overlap allowance 26 in a radial direction K is provided between the inner bent part 22 and the enlarged diameter part 18. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an anti-vibration bush used by being incorporated in an automobile suspension device or the like.

  2. Description of the Related Art Conventionally, in an automobile suspension device, a vibration isolating bush is used at a connection portion between a vehicle body and a suspension for the purpose of vibration damping and buffering. The anti-vibration bush is generally an inner cylinder, an outer cylinder arranged on the outer side of the inner cylinder, and a rubber-like elastic body that is interposed between the inner cylinder and the outer cylinder to elastically couple the two. And a vibration-proof substrate.

In such an anti-vibration bush, the following Patent Document 1 describes that the inner cylinder is pulled out of the outer cylinder when the anti-vibration base is peeled off or broken, and the two are completely separated from each other. In addition to providing an enlarged diameter portion at the axial end portion of the inner cylinder and bending the axial end portion of the outer cylinder radially inward to form an inner bent portion, the enlarged diameter portion and the inner bent portion It has been proposed to provide a radial overlap between them.
EP 1,250,538 B1

  In this type of anti-vibration bush, a metal pipe produced by drawing is generally used as the outer cylinder, and therefore, the outer cylinder is formed with a constant thickness in the axial direction. . When an outer cylinder having a constant wall thickness in the axial direction is used as described above, it is difficult to ensure a large overlap in the radial direction with the enlarged diameter portion of the inner cylinder when the inner bending portion is provided. There is a possibility that the effect of preventing the inner cylinder from being removed from the cylinder may be insufficient.

  This point will be described in detail using the anti-vibration bush 100 of the comparative example shown in FIG. The anti-vibration bush 100 includes a metallic inner cylinder 101 and an outer cylinder 102 arranged concentrically, and an anti-vibration base 103 made of a rubber elastic body arranged between both the cylinders 101 and 102. The inner cylinder 101 includes enlarged diameter portions 104 and 105 projecting radially outward at both ends. On the other hand, the outer cylinder 102 includes an inner bent portion 106 that is bent radially inward at one end portion in the axial direction X, and the inner bent portion 106 is between the enlarged diameter portion 104 facing the axial direction X. By having the overlap margin 107 in the radial direction K, the inner cylinder 101 is regulated so as not to come off from the outer cylinder 102 when the vibration-proof base 103 is broken or the like.

  As the outer cylinder 102, as shown in FIG. 8, a pipe product having a constant thickness in the axial direction X produced by drawing is used. In the case shown in FIG. 8, strictly speaking, the outer peripheral surface of the other end portion in the axial direction X (the upper end portion in the figure) is chamfered so that the outer cylinder can be easily press-fitted into a mounting hole such as a link member. The wall thickness is constant in the axial direction X except for the chamfered portion 108. In such an outer cylinder 102 having a constant wall thickness, when the inner bent portion 106 is bent at one end portion in the axial direction X, as shown in FIG. The overlap margin 107 becomes small. In this case, in order to ensure a large overlap allowance 107, it is necessary to increase the thickness of the entire outer cylinder 102, which is contrary to the demand for weight reduction due to an increase in weight.

  The present invention has been made in view of the above points, and an object thereof is to provide a vibration isolating bush that can improve the effect of preventing the inner cylinder from being detached from the outer cylinder while reducing the weight. .

  An anti-vibration bush according to the present invention is interposed between an inner cylinder, an outer cylinder arranged on the outer side of the inner cylinder at an interval, and the inner cylinder and the outer cylinder, and couples both cylinders. And an anti-vibration base made of a rubber-like elastic body. The inner cylinder includes an enlarged diameter portion projecting radially outward at one axial end, and the outer cylinder extends from one axial end. A cylindrical shape whose thickness gradually decreases toward the other end portion, and the one end portion on the thick wall side is bent inward in the radial direction and formed into an inner bent portion having an inner diameter smaller than the outer diameter of the enlarged diameter portion. It is a thing.

  According to the above configuration, the inner bent portion is bent at one end portion on the thick side using the outer cylinder whose thickness gradually decreases from one end portion to the other end portion in the axial direction. Since the one end portion where the inner bending portion is provided is thick, the inner bending portion can be extended further inward in the radial direction, and the radial overlap margin with the enlarged diameter portion is increased. Thus, the effect of preventing the inner cylinder from being pulled out can be enhanced. In addition, the thickness of the inner bent portion can be increased, and the effect of preventing the inner cylinder from being pulled out can also be increased by increasing the rigidity of the inner bent portion. And since the other end part side is thin if it is the said outer cylinder, compared with the case where thickness is constant in an axial direction, weight reduction can be achieved by suppressing a weight increase.

  The outer cylinder whose thickness gradually decreases from one end portion to the other end portion in the axial direction as described above can be formed by drawing a metal plate, thereby obtaining an outer cylinder whose thickness gradually decreases at low cost. be able to.

  In the above-mentioned vibration-proof bushing, it is preferable that a taper surface portion whose outer peripheral surface forms a taper surface shape by the drawing process is provided at the other end portion of the outer cylinder. Accordingly, the other end portion of the outer cylinder can be tapered without performing chamfering separately, and therefore, the outer cylinder can be easily press-fitted into a mounting hole such as a link member at a low cost.

  In the above-mentioned vibration-proof bushing, the one end portion of the outer cylinder may be formed at the inner bent portion whose distal end side is bent radially inward via a bulge portion protruding radially outward. Thus, by providing the bulging part which protrudes outside once and forming an inner bending part, the rigidity at the time of hitting an enlarged diameter part can be raised, and the removal prevention effect of an inner cylinder can be heightened.

  In the vibration-proof bushing, a shock-absorbing member made of a rubber-like elastic body may be provided on the outer surface of the inner bent portion that faces the enlarged diameter portion in the axial direction. By providing such a buffer member, it is possible to prevent abnormal noise by eliminating the contact between the rigid bodies of the inner bent portion and the enlarged diameter portion. In particular, in the present invention, since the overlap margin between the inner bent portion and the enlarged diameter portion is large as described above, the collision noise between the two is increased accordingly, but such an abnormal noise is prevented by providing a buffer member. can do.

  In the vibration isolating bush, the diameter-enlarged portion of the inner cylinder may be formed to have an enlarged diameter so as to expand an end surface by plastic working after vulcanization molding of the vibration-isolating base. By increasing the area of the end face, it is possible to secure a sufficient free length against elastic deformation and improve durability.

  With the anti-vibration bush of the present invention, it is possible to improve the effect of preventing the inner cylinder from being detached from the outer cylinder while reducing the weight.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows an anti-vibration bush 10 according to the first embodiment. The anti-vibration bush 10 includes an inner cylinder 12, an outer cylinder 14 disposed on the outer side of the inner cylinder 12, and a rubber that is interposed between the inner cylinder 12 and the outer cylinder 14 to couple the both cylinders 12 and 14. And an anti-vibration base 16 made of an elastic body.

  The inner cylinder 12 is a cylindrical member made of metal such as iron or aluminum and is longer than the outer cylinder 14. The inner cylinder 12 is formed with enlarged diameter portions 18 and 20 in which both end portions in the axial direction X project radially outward Ko over the entire circumference. The enlarged diameter portions 18 and 20 are formed with an enlarged diameter on the outside so as to enlarge the area of the end face of the inner cylinder 12, and the outer shape is formed in a circular shape in plan view. The means for providing the enlarged diameter portions 18 and 20 can be molded in advance by a processing method such as forging, but in this example, as described later, plastic processing after vulcanization molding of the vibration-proof base 16 is performed. Is adopted.

  The outer cylinder 14 is a cylindrical member made of metal such as iron or aluminum and thinner than the inner cylinder 12, and is configured to surround the inner cylinder 12 in an axially parallel and coaxial manner. One end portion (lower end portion) 14A in the axial direction X of the outer cylinder 14 is formed in an inner bent portion 22 that is bent radially inward Ki over the entire circumference. Specifically, in this example, the one end portion 14A is once radially expanded outward in the radial direction Ko over its entire circumference and then bent inward in the radial direction Ki, so that the radially outer side is formed. A distal end side is formed in an inwardly bent portion 22 that is bent radially inward Ki through a bulge portion 24 that protrudes in a curved shape in the direction Ko.

  The inner bent portion 22 extends to the radially inward Ki from the radially outer end 18A of the enlarged diameter portion 18 on the radially inner side Xi with respect to the enlarged diameter portion 18 at one end of the inner cylinder 12. Thus, the inner diameter φ1 is set smaller than the outer diameter φ2 of the enlarged diameter portion 18. As a result, the inner bending portion 22 is formed so as to have an overlap margin (lap allowance) 26 in the radial direction K between the inner diameter bending portion 22 and the larger diameter portion 18 at a position spaced apart from the larger diameter portion 18 in the axial direction X. Has been. Both the inner peripheral shape of the inner bending portion 22 and the outer shape of the bulging portion 24 are formed in a circular shape in plan view. Further, the outer diameter φ3 of the bulging portion 24 is set larger than the outer diameter φ2 of the enlarged diameter portion 18.

  In this embodiment, the outer cylinder 14 is used as the outer cylinder 14 from the one end 14A in the axial direction X by using a draw product shown in FIG. It has a cylindrical shape in which the wall thickness gradually decreases toward the end (upper end) 14B. That is, the thickness T1 of the one end portion 14A of the outer cylinder 14 is thicker than the thickness T2 of the other end portion 14B, and the thickness gradually decreases from the one end portion 14A to the other end portion 14B. .

  As shown in FIG. 5A, the outer cylinder 14 having such a thickness change is provided with a circular hole 52 in a flat metal plate 50, and the hole 52 is formed by pressing (drawing) using a punch. As shown in FIG. 5B, a cylindrical portion 54 is formed, and as shown in FIG. 5C, a flange-shaped plate portion 56 corresponding to the base portion of the cylindrical portion 54 is formed. By cutting, it can be produced so that the wall thickness gradually decreases from one end portion 14A on the base side to the other end portion 14B on the front end side. For example, the thickness T0 of the metal plate 50 is 1.6 mm, the thickness T1 of the one end portion 14A on the thick side is 1.8 mm, and the thickness T2 of the other end portion 14B on the thin side is 1.3 mm. A certain outer cylinder 14 is obtained.

  In the outer cylinder 14 obtained in this way, a tapered surface portion 28 is formed at the distal end portion (the axially outer end) of the other end portion 14B. The tip of the other end portion 14B is a portion corresponding to the opening edge of the hole 52, and this portion is particularly thinned by being pushed and widened by a punch at the time of drawing, and the thickness change of the entire cylindrical portion 54 The tapered surface portion 28 is formed because it is formed in a thin shape having a greater thickness change.

  The outer cylinder 14 having a change in thickness shown in FIG. 4 is then bent at the one end portion 14A on the thick side to form the bulging portion 24 and the inner bending portion 22 (see FIG. 1). .

  In the example shown in FIG. 4, the outer diameter of the outer cylinder 14 is constant in the axial direction X, and the change in thickness is formed by gradually increasing the inner diameter from the one end portion 14A to the other end portion 14B. On the other hand, after the drawing shown in FIG. 5C, the inner diameter is constant in the axial direction X, and the outer diameter gradually decreases from the one end portion 14A to the other end portion 14B. Therefore, the shape shown in FIG. 4 can be obtained by press-fitting a jig from the other end portion 14B on the thin wall side and expanding the inner peripheral surface on the other end portion 14B side. However, the shape shown in FIG. 5 (c) may be used as it is, and the one end portion 14A on the thick wall side may be bent. Even in this case, the outer diameter of the outer cylinder 14 can be made constant in the axial direction X at the time of reducing the diameter of the outer cylinder 14 after vulcanization molding, which will be described later. In any case, by keeping the outer diameter of the outer cylinder 14 constant in the axial direction X in the product state, it is possible to improve the press-fitting retention of the link member 1 in the mounting hole 2 (see FIG. 3).

  The anti-vibration base 16 is a cylindrical rubber member fixed to both the outer peripheral surface of the inner cylinder 12 and the inner peripheral surface of the outer cylinder 14 by vulcanization adhesion means. As shown in FIG. 1, on both end surfaces in the axial direction X of the vibration isolating base 16, annular straight portions 30, 32 that are recessed toward the axially inward Xi side are provided over the entire circumference, respectively, Free length against deformation is secured.

  The anti-vibration bush 10 of this embodiment can be manufactured as follows. That is, the inner cylinder 12 is a straight cylinder whose both ends are not expanded, and is cut slightly longer than the final product. The inner cylinder 12 and the outer cylinder 14 manufactured as described above are used. Is vulcanized and molded with an anti-vibration substrate 16 interposed therebetween. After the vulcanization molding, the outer cylinder 14 is subjected to a diameter reduction process in order to take the residual stress of the vibration-proof base 16 and pre-compress it. Further, the end portion of the inner cylinder 12 is plastically deformed and expanded in diameter by ironing with a processing jig that is eccentric to a constant angle with respect to the axis of the inner cylinder 12. As a result, as shown in FIG. 1, the undercut shape having the straight portions 30 and 32 on the end face of the vibration-proof base 16 can be obtained, and the area and free length of the end face can be sufficiently secured.

  The anti-vibration bush 10 obtained in this way is used by being incorporated in a link member 1 (see FIGS. 2 and 3) such as an upper support that connects between a suspension member of an automobile and a vehicle body, for example. In this use, the outer cylinder 14 is press-fitted into the mounting hole 2 penetrating in the vertical direction provided in the upper end portion of the link member 1 that supports the suspension member with the shaft center of the vibration isolating bush 10 being the vertical direction. And fix. On the other hand, a shaft member (not shown) such as a fastening pin is inserted into the inner cylinder 12 and fastened to a member on the vehicle body side such as a frame by the shaft member. At this time, as shown in FIG. 3, the outer cylinder 14 is fastened with the one end portion 14 </ b> A side where the inner bent portion 22 is formed facing down. Thus, the link member 1 fixed to the outer cylinder 14 is used so as to be suspended from the vehicle body. Therefore, the main load direction is the axial direction (vertical direction) X.

  The anti-vibration bush 10 according to the present embodiment having the above configuration is formed by bending the inner bent portion 22 at the one end portion 14A on the thick wall side using the outer cylinder 14 provided by changing the thickness by drawing. Therefore, a sufficient thickness for providing the inner bending portion 22 can be secured, and the inner bending portion 22 can be further extended to the radially inward Ki. Therefore, since the overlapping margin 26 in the radial direction K between the inner bent portion 22 and the enlarged diameter portion 18 facing in the axial direction X becomes large, even if the vibration isolating base 16 is broken or the like, It becomes difficult to come out from the outer cylinder 14, and the effect of preventing the inner cylinder 12 from being pulled out can be enhanced.

  In addition, since the one end portion 14A of the outer cylinder 14 on which the inner bending portion 22 is provided is thick, the thickness of the inner bending portion 22 can be increased, and the rigidity of the inner bending portion 22 can be increased. Therefore, also from this point, the effect of preventing the inner cylinder 12 from being pulled out can be enhanced.

  Moreover, in the case of the outer cylinder 14, since the other end portion 14 </ b> B side is thin, it is possible to reduce the weight while suppressing an increase in weight compared to the case where the thickness is constant in the axial direction X.

  In addition, according to the present embodiment, the outer cylinder 14 having the thickness change can be manufactured at a low cost by drawing the metal plate 50. Furthermore, since the tapered surface portion 28 can be formed on the other end portion 14B of the outer cylinder 14 by the drawing process, the outer cylinder 14 can be attached to the attachment hole of the link member 1 at a low cost without chamfering. 2 can be realized.

  In addition, since the one end portion 14A of the outer cylinder 14 is formed on the inner bending portion 22 through the bulging portion 24 that once protrudes outward, the rigidity when hitting the enlarged diameter portion 18 is increased, and the inner cylinder 12 is removed. The removal preventing effect can be further enhanced.

  FIG. 6 shows an anti-vibration bush 10A according to the second embodiment. This example differs from the above-described embodiment in that a buffer member 34 made of a rubber elastic body is provided on the outer side surface 22A of the inner bending portion 22.

  That is, in this example, the buffer member 34 is bonded and fixed to the outer surface (axial outer surface) 22A of the inner bending portion 22 that faces the enlarged diameter portion 18 of the inner cylinder 12 in the axial direction X. The buffer member 34 is made of a rubber elastic body that continues from the vibration-proof base 16 on the axially inner Xi side, and is vulcanized and bonded to the outer surface 22A of the inner bent portion 22 over the entire circumference. On the inner peripheral surface of the inner bending portion 22, a rubber film 36 that connects the vibration-proof base 16 and the buffer member 34 is provided.

  In the second embodiment, by providing the buffer member 34, it is possible to eliminate the contact between the metal of the enlarged diameter portion 18 of the inner cylinder 12 and the inner bent portion 22 of the outer cylinder 14, and the two interfere with each other. It is possible to prevent abnormal noise caused by the operation.

  Other configurations and operational effects are the same as those of the first embodiment. For this reason, the overlap margin 26 between the enlarged diameter portion 18 and the inner bending portion 22 is large, and accordingly, abnormal noise due to interference between both the portions 18 and 22 becomes large. According to the second embodiment, the buffer member 34 is By providing, such abnormal noise can be effectively prevented.

  In the above embodiment, the enlarged diameter portions 18 and 20 are provided at both end portions of the inner cylinder 12, but the enlarged diameter portion may be provided only at one end portion facing the inner bent portion 22 of the outer cylinder 14. Moreover, in the said embodiment, although the enlarged diameter parts 18 and 20 were provided by the plastic working of the inner cylinder 12, an enlarged diameter part is comprised by fixing a separate flange part to the end surface of the inner cylinder 12 by welding etc. May be.

  Moreover, in the said embodiment, although the bulging part 24 was interposed in the base side of the inner bending part 22 of the outer cylinder 14, the inner bending part 22 directly from the main-body part of the outer cylinder 14, without providing such a bulging part. May be formed. Although not enumerated one by one, various modifications can be made without departing from the spirit of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used for various types of anti-vibration bushes such as an anti-vibration bush used in an automobile suspension device and a cylindrical anti-vibration bush as an engine mount.

Sectional view of the vibration-proof bushing according to the first embodiment Plan view of the anti-vibration bush attached to the link member III-III sectional view of FIG. Cross-sectional view of the outer cylinder used for the anti-vibration bush Sectional drawing which shows the manufacturing process of this outer cylinder Sectional view of vibration-proof bushing according to the second embodiment Sectional view of anti-vibration bush according to comparative example Sectional view of the outer cylinder used for the anti-vibration bush of the comparative example

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,10A ... Anti-vibration bush 12 ... Inner cylinder 14 ... Outer cylinder, 14A ... One end part, 14B ... Other end part 16 ... Anti-vibration base | substrate 18 ... Expanding part 22 ... Inner bending part, 22A ... Outer side surface 24 ... Swelling part 26 ... Overlap 28 ... Tapered surface portion 34 ... Buffer member K ... Radial direction, Ko ... Radially outward, Ki ... Radially inward X ... Axial direction, Xi ... Axial inward φ1 ... Inner bent portion inner diameter φ2 ... Outer diameter of expanded part

Claims (6)

An anti-vibration base comprising an inner cylinder, an outer cylinder arranged on the outer side of the inner cylinder with a gap, and a rubber-like elastic body interposed between the inner cylinder and the outer cylinder to couple the two cylinders And
The inner cylinder includes an enlarged diameter portion projecting radially outward at one axial end portion,
The outer cylinder has a cylindrical shape in which the wall thickness gradually decreases from one end portion to the other end portion in the axial direction, and the one end portion on the thick wall side is bent inward in the radial direction so as to be larger than the outer diameter of the enlarged diameter portion. An anti-vibration bush characterized by being formed in an inner bending part with a small inner diameter.   The anti-vibration bush according to claim 1, wherein the outer cylinder is formed in a cylindrical shape whose thickness gradually decreases from one end portion to the other end portion in the axial direction by drawing of a metal plate.   The anti-vibration bushing according to claim 2, wherein a tapered surface portion having an outer peripheral surface tapered by the drawing is provided at the other end portion of the outer cylinder.   The said one end part of the said outer cylinder is formed in the said inner bending part by which the front end side was bent inward in the radial direction via the bulging part which protruded radially outward. The anti-vibration bush according to any one of claims.   5. The prevention according to claim 1, wherein a buffer member made of a rubber-like elastic body is provided on an outer surface of the inner bending portion facing in the axial direction with respect to the enlarged diameter portion. Swing bush.   The vibration isolator according to any one of claims 1 to 5, wherein the diameter-enlarged portion of the inner cylinder is formed with an enlarged diameter so as to expand an end surface by plastic working after vulcanization molding of the vibration-proof base. bush.

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