JP2008298195A - Vibration control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration control device reduced in weight, by reducing the number of part items and assembling man-hours, while securing stopper performance. <P>SOLUTION: This vibration control device 10 is composed of an inner cylinder 12, an outside member 14 and a vibration control base body 16. The outside member 14 is composed of a cross-sectional U-shaped body part 18 opened in the direction Y perpendicular to the axis of the inner cylinder 12, and right-left installation plate parts 20 and 20 respectively bent and formed outward from its right-left opening ends and installed on an installation object surface 2A such as a vibrator. By constituting the vibration control base body 16 of right-left connecting supporting parts 30, a first cavity part 32 is arranged on the upper side of the inner cylinder 12, and a second cavity part 34 is arranged on the lower side of the inner cylinder 12. In the second cavity part 34, a stopper rubber part 40 opposed to the installation object surface is arranged on the inner cylinder 12 side while securing a clearance 42 as a stopper clearance between the part and the installation object surface 2A, and the stopper action is exhibited by abutting on the installation object surface 2A to downward relative displacement of the inner cylinder 12. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vibration isolator.

  2. Description of the Related Art Conventionally, a bush-type vibration isolator is known that includes an inner cylinder, an outer cylinder that surrounds the inner cylinder, and an anti-vibration base made of a rubber material interposed between the inner cylinder and the outer cylinder. . Such a bush-type vibration isolator is assembled to a vehicle by attaching an inner cylinder to one of a vibration body such as an engine and a support body such as a vehicle body and attaching an outer cylinder to the other via a bracket. The bracket includes a cylindrical holder into which an outer cylinder is press-fitted and an attachment plate for attaching the cylindrical holder to a vehicle body or the like, and is formed by welding the cylindrical holder to the attachment plate.

  In the above conventional structure, the bush has a metal outer cylinder, and the outer cylinder is press-fitted into the metal cylindrical holder, so that the mass is heavy. Further, since it is necessary to weld the bracket, and a process of press-fitting the bush into the bracket is also necessary, the number of assembly steps and the number of parts are large.

  Therefore, Patent Documents 1 and 2 below propose a configuration in which an outer cylinder is omitted and a bush formed by molding a rubber elastic body around the inner cylinder is directly press-fitted and held in a cylindrical holder of the bracket. In these configurations, although the outer cylinder can be omitted, the bracket itself is the same as the above-described conventional structure, and a press-fitting process is also required, so that the above problem has not been sufficiently solved.

  Patent Document 3 below discloses a configuration in which an outer cylinder is omitted and a rubber elastic body of an anti-vibration bush is directly vulcanized and molded into a cylindrical holder of a resin bracket. Even in this configuration, the shape of the bracket itself includes a cylindrical holder surrounding the entire circumference of the inner cylinder and a base for attaching the cylindrical holder to a vehicle body or the like, as in the prior art. When it is made of metal, it cannot achieve a sufficient weight reduction.

Further, in Patent Document 4 below, an outer cylinder is formed in a substantially C shape, and a flange portion that is bent outward is provided at the opposite end of the outer cylinder, and the inner cylinder is interposed between the outer cylinder and a rubber elastic body. Thus, an anti-vibration bush that omits the bracket has been proposed. However, in this vibration isolating bush, a connecting piece provided with an attaching portion for attaching to a vehicle body or the like is essential, and the connecting piece is configured to close the C-shaped opening of the outer cylinder. Therefore, after all, the outer cylinder also serving as the bracket is provided over the entire circumference of the inner cylinder, so that sufficient weight reduction cannot be achieved, and the effect of reducing the number of parts is insufficient.
Japanese Patent Laid-Open No. 06-264968 Japanese Patent Application Laid-Open No. 07-019273 Japanese Patent Laid-Open No. 06-173990 JP 05-296273 A

  In view of the above points, an object of the present invention is to provide a vibration isolator capable of reducing the number of parts and the number of assembly steps and reducing the weight while securing performance.

  The vibration isolator according to the present invention includes a shaft member that is attached to one of the vibration body and the support, an outer member that is attached to the other attached surface, and is provided around the shaft member, And a vibration-proof base made of a rubber material interposed between the shaft member and the outer member. The outer member has a U-shaped cross section opened in a direction perpendicular to the axis of the shaft member, and surrounds the shaft member around the shaft member in parallel with the axis except for the opening side of the U-shape, Left and right attachment plate portions that are bent outwardly from the left and right opening ends of the main body and attached to the attachment surface. In addition, the anti-vibration base is composed of left and right connection support portions that are bonded to the left and right side portions of the shaft member and the inner peripheral surfaces of the left and right side portions of the main body portion facing the both side portions and connect the two. Accordingly, a first cavity that penetrates in the axial direction is provided between the U-shaped bottom portion of the main body and the shaft member, and penetrates in the axial direction on the opening side of the U-shape with respect to the shaft member. A second cavity is provided. Then, the outer peripheral surface of the shaft member on the second cavity portion side is opposed to the attached surface while ensuring a gap with the attached surface, and toward the second cavity portion side of the shaft member. A stopper rubber portion is provided for exerting a stopper action by abutting against the mounted surface against the relative displacement.

  According to the said structure, since the function of the conventional outer cylinder and a bracket is exhibited by an outer member, a press-fit process becomes unnecessary any longer. Further, since the mounting plate portion is integrally bent from the opening end of the U-shaped main body portion on the outer member, a welding process is not required, thereby reducing the number of assembly steps and the number of parts. Is done. Further, the outer member does not surround the outer periphery of the shaft member over the entire circumference, and is opened at one place in the circumferential direction, so that a sufficient weight reduction can be achieved. Further, the surface to be attached to which the outer member is attached is used as a stopper receiving surface for receiving the stopper rubber portion on the shaft member side, thereby providing a stopper action against excessive displacement toward the opening side (second cavity portion side) of the shaft member. Since it was demonstrated, the stopper performance can be ensured while exhibiting an excellent lightening effect.

  In the vibration isolator, the main body portion of the outer member includes a semicircular portion having a semicircular cross section and extending in the axial direction, and a pair of straight portions extending in parallel from both ends of the semicircular portion. When configured, the following effects are exhibited. That is, since the U-shaped main body portion is formed by extending straight from the diameter portion having the maximum width of the semicircular shape, the outer member can be pressed in one step.

  In the above configuration, the distance (D1) from the center of the circle defining the semicircular portion of the outer member to the bottom of the U-shape is greater than the distance (D2) from the center of the circle to the opening surface of the main body. Is set to a large value, the following effects can be obtained. In other words, the moment can be reduced even with an excessive input in the direction of the U-shaped bottom of the shaft member, and further weight reduction can be achieved by reducing the plate thickness of the outer member.

  As described above, with the vibration isolator of the present invention, it is possible to reduce the number of parts and the number of assembly steps and to reduce the weight while securing the performance such as the stopper performance.

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

  1 is a front view of a vibration isolator 10 according to an embodiment of the present invention, FIG. 2 is a plan view, and FIG. 3 is a cross-sectional view. This anti-vibration device 10 is a bush-type anti-vibration device that is disposed between a transmission connected to an automobile engine and a vehicle body and couples them together.

  As shown in FIG. 4, the vibration isolator 10 includes an inner cylinder 12 as a shaft member attached via a bolt 1 to a vehicle body (not shown) as a support, and an axis parallel to the periphery of the inner cylinder 12. An outer member 14 that is provided and attached to the transmission 2 that is a vibrating body, and a vibration-proof base 16 made of a rubber elastic body interposed therebetween are provided, and the transmission 2 is suspended from and supported by the vehicle body. This is a type of vibration isolator. Therefore, the inner cylinder 12 is relatively displaced upward Y2 due to the initial load of the transmission 2 in a state where it is assembled to the vehicle.

  The inner cylinder 12 is a cylindrical metal member and is configured to be assembled to the vehicle body with its axis O oriented horizontally.

  The outer member 14 is a metal press-molded product, and has a U-shaped cross section opened toward the axis-perpendicular direction Y of the inner cylinder 12. In this example, the outer member 14 is opened toward the lower Y1. It has a letter shape. Specifically, the outer member 14 has a U-shaped cross-section and surrounds the inner cylinder 12 around the inner cylinder 12 in parallel with the axis except for the opening side of the U-shape, and left and right openings of the main body 18. Left and right mounting plate portions 20 and 20 that are bent outwardly from the ends 18A and 18A and are attached to the mounted surface 2A of the transmission 2 are provided. As shown in FIG. 2, the outer member 14 is set such that the dimension in the axial direction X is smaller than the dimension in the axial direction X of the inner cylinder 12.

  In this example, the main body 18 includes a semicircular portion 22 that has a semicircular cross section and surrounds the outer peripheral portion on the upper side of the inner cylinder 12, and both ends in the circumferential direction of the semicircular portion 22 (that is, a diameter portion having a maximum width). End portions) 22A, 22A and a pair of straight portions 24, 24 extending in parallel toward the lower portion Y1 to form the U-shape. The mounting plate 20 extends from the lower end of the straight portion 24 at a right angle outward.

  The mounting plate portion 20 is provided with a through hole 26 through which a bolt 3 (see FIG. 4) for fixing to the mounting surface 2A of the transmission 2 is inserted. Further, a bead 28 is provided and reinforced inside the bent portion of the mounting plate 20 and the main body 18.

  The anti-vibration base 16 is vulcanized and bonded to the left and right side portions 12A and 12A of the inner cylinder 12 and the inner peripheral surfaces 18C of the left and right side portions 18B and 18B of the main body 18 facing the both side portions 12A and 12A. It is constituted by a pair of left and right connection support portions 30, 30 that connect the both 12, 18. In detail, both the connection support parts 30 and 30 respectively incline and extend upward (namely, the opposite side to opening direction Y1) Y2 toward the outer member 14 from the inner cylinder 12 side. Accordingly, the anti-vibration base 16 is formed in a V shape with the inner cylinder 12 side as a bottom portion by the left and right connection support portions 30 and 30.

  Due to the configuration of the vibration isolating substrate 16, hollow portions are provided above and below the inner cylinder 12. Specifically, a first cavity portion 32 penetrating in the axial direction X is provided between the U-shaped bottom portion 18 </ b> D of the main body portion 18 and the inner cylinder 12 in the upper Y <b> 2 of the inner cylinder 12. A second cavity 34 that is wider than the first cavity 32 and penetrates in the axial direction X is provided on the lower Y1, that is, on the opening side of the U-shape with respect to the inner cylinder 12. The second cavity portion 34 is also opened in the lower portion Y1, that is, the opening surface 18E of the U-shaped main body portion 18 opens downward without being blocked as the vibration isolator 10 alone.

  In the first cavity portion 32, an upper stopper rubber portion 36 is provided in a convex shape from the main body portion 18 side of the outer member 14. The upper stopper rubber portion 36 is vulcanized and bonded to the inner peripheral surface 18C of the bottom portion 18D of the main body portion 18 and is formed of the same rubber elastic body that is continuous from the vibration-proof base 16. The front end surface (lower surface) of the upper stopper rubber portion 36 is formed flat, and when the inner cylinder 12 is excessively displaced upward Y2, the inner cylinder 12 (specifically, the upper surface of the inner cylinder 12 is covered with the upper cylinder side). By abutting against a rubber layer 38) made of a rubber elastic body, a stopper action for restricting the relative displacement of the inner cylinder 12 is exhibited. Due to the shape of the upper stopper rubber portion 36, the first cavity portion 32 is formed in a triangular cross section.

  In the second cavity portion 34, a lower stopper rubber portion 40 is provided from the inner cylinder 12 side toward the lower portion Y1. The lower stopper rubber portion 40 is vulcanized and bonded to the outer peripheral surface 12B of the inner cylinder 12 on the second cavity portion 34 side. In this example, the lower stopper rubber portion 40 is formed of the same rubber elastic body that is continuous from the vibration-proof base 16. Yes. Therefore, the entire circumference of the inner cylinder 12 is embedded in the bottom portion of the vibration isolation base 16.

  The lower stopper rubber portion 40 is smoothly continuous from the inclined surface on the lower surface side of the connection support portion 30 of the vibration-isolating base 16, and has a cross-sectional shape that bulges toward the lower portion Y1. As shown in FIG. 4, the lower stopper rubber portion 40 faces the mounting surface 2 </ b> A while ensuring a predetermined gap 42 as a stopper clearance with the flat mounting surface 2 </ b> A of the transmission 2. Is provided. The lower stopper rubber portion 40 abuts against the attached surface 2 </ b> A against the excessive displacement of the inner cylinder 12 toward the second cavity portion 34, thereby exhibiting a stopper action.

  In addition, the said clearance gap 42 should just be provided between 2 A of to-be-attached surfaces in the state assembled | attached to the vehicle shown in FIG. 4 (namely, the state in which the initial load of the transmission 2 was loaded). In this example, as shown in FIG. 1, in the state of the vibration isolator 10 alone, the tip (lower end) of the lower stopper rubber portion 40 is on the opening surface 18E of the main body 18 or from the opening surface 18E. Is also located slightly above Y2.

  As shown in FIG. 1, in the state of the vibration isolator 10 alone, the inner cylinder 12 has its axis O not on the axis P of the outer member 14 (the center of the circle defining the semicircular portion 22) P. , The axis P is disposed at a position shifted downward Y1 (ie, in the opening direction). And it is comprised so that the axial center O of the inner cylinder 12 may correspond with the axial center P of the outer side member 14 in the state assembled | attached to the vehicle shown in FIG.

  In this example, the distance (D1) from the center of the circle defining the semicircular portion 22 of the outer member 14 (ie, the axis P) to the upper U-shaped bottom portion 18D, ie, the radius of the circle, is It is set to be larger than the distance (D2) from the center P of the circle to the opening surface 18E of the lower body 18. As a result, the moment can be reduced even with an excessive input in the U-shaped bottom portion direction of the inner cylinder 12, and further weight reduction can be achieved by reducing the plate thickness of the outer member 14.

  In the vibration isolator 10 of the present embodiment configured as described above, the vibration isolator base 16 is integrally vulcanized with the inner cylinder 12 using the outer member 14 having a bracket function. A process becomes unnecessary. Further, since the outer plate 14 is integrally formed with the mounting plate portions 20 and 20 from the open end 18A of the U-shaped main body portion 18, a welding process is not required, thereby reducing the number of assembling steps. At the same time, the number of parts is reduced.

  Further, the outer member 14 does not surround the outer periphery of the inner cylinder 12 over the entire circumference, and is opened at one place in the circumferential direction, so that a sufficient weight reduction can be achieved.

  Furthermore, using the attached surface 2A to which the outer member 14 is attached as a stopper receiving surface for receiving the lower stopper rubber portion 40 on the inner cylinder 12 side, a stopper action against excessive displacement of the inner cylinder 12 downward Y1 is provided. Since it was demonstrated, the stopper performance can be ensured while exhibiting an excellent lightening effect.

  In addition, since the main body portion 18 of the outer member 14 is formed in a U-shaped cross section by directly extending the straight portion 24 from the diameter portion which is the maximum width of the semicircular portion 22, the so-called undercut shape is eliminated, and the outer member is removed. 14 can be pressed in one stage, and the number of press steps can be reduced.

The front view of the vibration isolator which concerns on 1 embodiment of this invention. Top view of the vibration isolator III-III sectional view taken on the line of FIG. Sectional drawing which shows the assembly | attachment state to the vehicle of the vibration isolator

Explanation of symbols

1 ... Bolt (support side)
DESCRIPTION OF SYMBOLS 2 ... Transmission (vibrating body), 2A ... Mounted surface 10 ... Vibration isolator 12 ... Inner cylinder (shaft member), 12A ... Left and right both sides, 12B ... Outer peripheral surface 14 ... Outer member 16 ... Anti-vibration base 18 ... Main part , 18A ... Open end, 18B ... Both left and right sides, 18C ... Inner peripheral surface, 18D ... Bottom, 18E ... Opening surface 20 ... Mounting plate part 22 ... Semi-circular part, 22A ... Both ends 24 ... Straight part 30 ... Connection support part 32 ... 1st cavity part 34 ... 2nd cavity part 40 ... Lower stopper rubber part 42 ... Gap G ... Outer O ... Axle center P of inner cylinder ... Center X of circle defining semicircular part ... Axial direction Y ... Axis Right angle direction, Y1 ... Down (opening side)
D1: Distance from the center of the outer member circle to the bottom of the U-shape D2: Distance from the center of the outer member circle to the opening of the main body

Claims (3)

A shaft member attached to one of the vibrating body and the support, an outer member attached to the other attached surface and provided around the shaft member, and between the shaft member and the outer member A vibration isolating base comprising a vibration isolating base made of a rubber material interposed in
A main body that has a U-shaped cross-section that is open in a direction perpendicular to the axis of the shaft member and that surrounds the shaft member in parallel to the axis except for the opening side of the U-shape; Left and right mounting plate parts that are bent outwardly from the left and right opening ends of the part and attached to the attached surface,
The anti-vibration base is composed of left and right connection support portions that are bonded to the left and right side portions of the shaft member and the inner peripheral surfaces of the left and right side portions of the main body portion facing the both side portions, thereby connecting the two. A first cavity portion that penetrates in the axial direction is provided between the U-shaped bottom portion of the main body portion and the shaft member, and a first cavity portion that penetrates in the axial direction on the opening side of the U shape with respect to the shaft member. 2 cavities are provided,
The outer peripheral surface of the shaft member on the second cavity portion side is opposed to the mounting surface while ensuring a gap between the mounting surface and the shaft member relative to the second cavity portion side. A stopper rubber part is provided for exerting a stopper action by abutting the mounted surface against displacement.
Anti-vibration device.   The anti-vibration device according to claim 1, wherein the main body portion includes a semicircular portion having a semicircular cross section and extending in the axial direction, and a pair of straight portions extending in parallel from both ends of the semicircular portion. apparatus.   The distance (D1) from the center of the circle defining the semicircular portion of the outer member to the bottom of the U-shape is set to be larger than the distance (D2) from the center of the circle to the opening surface of the main body. The vibration isolator according to claim 2.

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