JP6430224B2 - Vibration isolator - Google Patents

Description

  The present invention relates to a vibration isolator, and more particularly to a vibration isolator capable of improving durability.

  Conventionally, a pair of elasticity composed of an inner member, a cylindrical outer member arranged on the outer peripheral side of the inner member with a space from the inner member, and a rubber-like elastic body connecting the inner member and the outer member. An anti-vibration device including a leg portion is known (for example, Patent Document 1).

Japanese Utility Model Publication No. 6-22639

  However, in the above-described technique, if the inner member and the outer member are relatively displaced in the direction intersecting the axial direction of the inner member and the outer member, and the elastic legs are strained in the tensile direction, the durability may be reduced. It was.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a vibration isolator capable of improving durability.

Means for Solving the Problems and Effects of the Invention

In order to achieve this object, according to the vibration isolator according to claim 1, a pair of cylindrical outer members are arranged on the outer peripheral side of the inner member with a space from the inner member, and are constituted by a rubber-like elastic body. The inner member and the outer member are connected by the elastic legs. The elastic leg portion includes a central portion that is a portion located in the center in the axial direction of the inner member and the outer member, a first end portion that is a portion that is connected to one side of the central portion in the axial direction, And a second end portion that is a portion continuously provided on the other side in the axial direction. Central portion, Ru comprises a central wall surface forming the outline of the elastic leg portions when viewed from the axial direction. The first end portion includes a first wall surface connected to one axial side of the central portion and an end point of one end surface of the elastic leg portion in the axial direction, and the first wall surface extends in the axial direction from the central wall surface. Located on the inner side in the axial direction and circumferential direction from the virtual fillet surface that smooths the corner of the ridge where the extended virtual surface and the virtual surface extending from one end surface in the axial direction of the elastic leg portion in the circumferential direction intersect . The second end portion includes a second wall surface connected to the other axial end of the central portion and the end of the other end surface of the elastic leg in the axial direction. The second wall surface extends in the axial direction from the central wall surface. Located on the inner side in the axial direction and circumferential direction from the virtual fillet surface that smooths the corner of the ridge where the extended virtual surface and the virtual surface extending from the end point in the circumferential direction to the other end surface in the axial direction of the elastic leg portion intersect . Thereby, the strain in the tensile direction generated in the elastic legs when the inner member and the outer member are relatively displaced in the direction intersecting the axial direction of the inner member and the outer member can be dispersed by the first wall surface and the second wall surface. Compared with the case where the first wall surface and the second wall surface are not provided, the distortion can be reduced, and thus there is an effect that durability can be improved.
In the cross section perpendicular to the radial direction of the outer member, the first wall surface and the second wall surface are two curved surfaces that protrude outward in the axial direction, and inflections in which the direction of the unevenness changes between the two curved surfaces. Each. Thereby, compared with the case where there is no inflection part in the 1st wall surface and the 2nd wall surface, since the 1st wall surface and the 2nd wall surface can penetrate deeply in the peripheral direction, the elasticity by the 1st wall surface and the 2nd wall surface The amount of leg thinning can be secured.

According to the vibration isolator of claim 2 , the first wall surface and the second wall surface are located on the inner member side from the radial center of the first end portion and the second end portion when viewed from the axial direction. The area between the central wall surface and the end point is set so as to be larger than the area between the central wall surface and the end point at a portion located on the outer member side from the radial center of the first end portion and the second end portion. The Thereby, the fall of the spring of an elastic leg part can be suppressed, disperse | distributing the distortion | strain of the tension | pulling direction concentrated on the vicinity of the outer member of an elastic leg part. Therefore, in addition to the effect of the first aspect , there is an effect that durability can be improved while suppressing a decrease in the spring of the elastic leg portion.

According to the vibration isolator of claim 3 , the outer member is cylindrical. The first wall and the second wall includes a central wall as at a site from the center of the first end and the radial direction of the second end portion positioned on the inner member side, as viewed in the axial direction, toward the inner member radially outward The length of the outer member on the concentric circle between the end point and the end point is set to be long . Thereby, the fall of the spring of the elastic leg part of the vicinity of an inner member can be suppressed. Therefore, in addition to the effect of the second aspect , there is an effect that the durability can be improved while further suppressing the lowering of the spring of the elastic leg portion.

According to the vibration isolator of claim 4 , the first end portion and the second end portion have axial lengths set to 1/6 to 1/2 of the axial length of the elastic leg portion, respectively. Has been. Therefore, in addition to the effect of any one of claims 1 to 3 , there is an effect that durability can be improved while suppressing a decrease in the spring of the elastic leg portion.

It is a top view of the vibration isolator in 1st Embodiment of this invention. It is a top view of the 1st bush. It is a bottom view of the 1st bush. It is a perspective view of the 1st bush. It is sectional drawing of the elastic leg part in the VV line | wire of FIG. FIG. 6 is a half sectional view of the first bush taken along line VI-VI in FIG. 2. (A) is an isoline diagram of the largest principal strain which arises in an elastic leg part when an inner member and an outer member are relatively displaced to the direction orthogonal to an axis, (b) is an isoline diagram of a comparative example. . It is a top view of the vibration isolator in 2nd Embodiment. It is sectional drawing of the elastic leg part in the IX-IX line of FIG.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of the vibration isolator 1 according to the first embodiment of the present invention, FIGS. 2 and 3 are a plan view and a bottom view of the first bush 10, respectively, and FIG. It is a perspective view.

  As shown in FIG. 1, the vibration isolator 1 includes a first bush 10 and a second bush 20, and a connecting member 30 that connects the first bush 10 and the second bush 20 to each other. Is a device that suppresses relative displacement of the engine while suppressing vibration transmission. In the present embodiment, the first bush 10 is connected to the vehicle body side (right side of FIG. 1, not shown), and the second bush 20 is connected to the engine side (left side of FIG. 1, not shown).

  The first bush 10 includes an inner member 11 attached to the vehicle body side (not shown), a cylindrical outer member 12 positioned on the outer peripheral side of the inner member 11 and connected to the connecting member 30, and the outer member 12 and the inner member. A pair of elastic legs 13 are provided that are interposed between the members 11 and are made of an elastic material (rubber-like elastic material). The inner member 11 is made of an aluminum alloy in a cylindrical shape, and the outer member 12 is made of a steel material in a cylindrical shape. The first bush 10 is connected to the vehicle body side by inserting a bolt (not shown) through a bolt insertion hole formed through the center of the inner member 11 and fastening the bolt to the vehicle body side.

  The second bush 20 includes a cylindrical inner member 21 attached to the engine side (not shown), a cylindrical outer member 22 positioned on the outer peripheral side of the inner member 21 and connected to the connecting member 30, and an outer member. 22 and an inner member 21 and an anti-vibration base 23 made of an elastic material (rubber-like elastic material). The second bush 20 is connected to the engine side by inserting a bolt (not shown) through a bolt insertion hole formed through the center of the inner member 21 and fastening the bolt to the engine side.

  The connecting member 30 includes a first cylinder member 31 and a second cylinder member 32, and a bracket member 33 to which the first cylinder member 31 and the second cylinder member 32 are fixed by welding at both ends. The first cylinder member 31 and the second cylinder member 32 are members into which the outer member 12 of the first bush 10 and the outer member 22 of the second bush 20 are respectively fitted and press-fitted, and are configured in a tubular shape from a steel material. . The bracket member 33 is formed in a cylindrical shape from a steel material, and the outer peripheral surfaces of the first cylinder member 31 and the second cylinder member 32 are welded and fixed to both ends thereof.

  As shown in FIG. 2, the first bush 10 includes a pair of elastic legs 13, 13 that connect the inner member 11 and the outer member 12, and a stopper portion 14 provided on the outer member 12 toward the inner member 11. 15. The pair of elastic legs 13, 13 are arranged in a V shape when viewed from the axial direction of the inner member 11 and the outer member 12 (the direction perpendicular to the plane of FIG. 1). The outer member 12 is formed with a superior arc (right side in FIG. 2) and an inferior arc (left side in FIG. 2) by sandwiching the elastic legs 13, 13 at two locations on the circumference. The stopper portion 14 is disposed in the inferior arc portion of the outer member 12, and the stopper portion 15 is disposed in the superior arc portion of the outer member 12. The inner member 11 is provided with contact portions 16 and 17 on outer peripheral surfaces facing the stopper portions 14 and 15, respectively. The elastic leg portion 13, the stopper portions 14 and 15, and the contact portions 16 and 17 are integrally formed from a rubber-like elastic body and vulcanized and bonded to the outer peripheral surface of the inner member 11 and the inner peripheral surface of the outer member 12. .

  In the first bush 10 (see FIG. 1), the outer member 12 is press-fitted into the first cylinder member 31 by aligning the position of the stopper portion 14 with the position where the bracket member 33 is fixed to the first cylinder member 31. In the present embodiment, the vibration isolator 1 includes a first bush 10 on the rear side of the vehicle and a second bush 20 on the front side of the vehicle, and a connecting member along the vehicle length direction (the vehicle front-rear direction). It is mounted on the vehicle so that the longitudinal direction of 30 (bracket member 33) is arranged. As a result, the first bush 10 has the pair of elastic legs 13 and 13 arranged in line symmetry with respect to the axis of the connecting member 30.

  During acceleration of the vehicle, the inner member 11 of the first bush 10 is moved relative to the outer member 12 (first tube member 31) due to relative displacement between a vehicle body (not shown) attached to the inner member 11 and the engine. It moves to the stopper part 14 side relatively. When the vehicle travels at a reduced speed, the inner member 11 moves relative to the outer member 12 (first cylinder member 31) relative to the outer member 12 due to relative displacement between a vehicle body (not shown) attached to the inner member 11 and the engine. Move to the side. The inner member 11 moves relative to the outer member 12 until the abutting portion 17 comes into contact with the stopper portion 15, and a tensile force mainly in the direction of arrow P acts on the elastic leg portion 13.

  Due to this tensile force, strain (tensile strain) is concentrated in the vicinity of the outer member 12 on the circumferential end surface on the side close to the stopper portion 14 of the elastic leg portion 13 (the inferior arc side away from the stopper portion 15). Therefore, the durability of the elastic leg 13 may be reduced. Therefore, in order to disperse the tensile strain and improve the durability of the elastic leg portion 13, the elastic leg portion 13 is a first in which a part of the end surface close to the stopper portion 14 is thinned in the circumferential direction and the axial direction. A wall surface 51 and a second wall surface 61 (see FIG. 3) are provided. In addition, since the free length of the circumferential end surface (right side in FIG. 2) near the stopper portion 15 is longer than the free length of the circumferential end surface (left side in FIG. 2) close to the stopper portion 14, the elastic leg portion 13 The first wall surface 51 and the second wall surface 61 are not necessarily provided on the near circumferential end surface.

  As shown in FIG. 4, the first wall surface 51 is provided at a portion where the circumferential end surface of the elastic leg portion 13 facing the stopper portion 14 intersects the axial end surface of the elastic leg portion 13. The first wall surface 51 is a surface that enters in the axial direction as it goes in the circumferential direction. The first wall surface 51 is located between the two curved surfaces that are adjacent to the circumferential direction and extend in the axial direction, and the direction of the unevenness changes. And a curved portion 52. The first wall surface 51 is formed closer to the inner member 11 of the elastic leg portion 13.

  The elastic leg 13 will be described with reference to FIGS. FIG. 5 is a cross-sectional view of the elastic leg 13 taken along the line V-V in FIG. 2, and the illustration of the outer member 12 is omitted. 6 is a half sectional view of the first bush 10 taken along line VI-VI in FIG. 2, and FIG. 7 is a side view of the elastic leg 13. 5 to 7 indicate the axial direction, the circumferential direction, and the radial direction of the first bush 10 (the same applies in FIG. 9).

  As shown in FIG. 5, the elastic leg portion 13 is connected to the central portion 40 located in the center in the axial direction (arrow A direction) of the inner member 11 and the outer member 12, and to one side in the axial direction of the central portion 40. A first end 50 and a second end 60 connected to the other side of the central portion 40 in the axial direction are provided, and these are integrally molded from a rubber-like elastic body. The elastic leg 13 forms a contour S in the projection in the axial direction (arrow A direction).

  The central portion 40 includes a central wall surface 41 that forms a contour S (left side, short side contour in FIG. 5) on the stopper portion 14 (see FIG. 2) side of the contour S of the elastic leg portion 13 in the axial projection. Yes. The first end portion 50 has a first wall surface 51 that is coupled to the central wall surface 41. The first wall surface 51 extends from the end point 42 in the axial direction by extending the central wall surface 41 in the axial direction, and extends from the end point 53 in the circumferential direction to the axial end surface 54 of the first end 50. A hollow surface located inside the axial direction (arrow A direction) and the circumferential direction (arrow C direction) from the virtual fillet surface F1 that smoothes the corner of the ridge where the virtual surface coupled to the axial end surface 54 intersects And entering the circumferential direction from the central wall surface 41 as viewed from the axial direction.

  The first wall surface 51 has an inflection portion 52 in which the inclination with respect to the axis O in the contour line of the cross section shown in FIG. ing. Since there exists the inflection part 52, compared with the case where there is no inflection part 52, the 1st wall surface 51 can be penetrated deeply in the circumferential direction (arrow C direction), and the elastic leg part 13 by the 1st wall surface 51 can be made. The amount of thinning can be secured.

  The second end portion 60 has a second wall surface 61 that is coupled to the central wall surface 41. The second wall surface 61 extends from the end point 43 in the circumferential direction by extending the central wall surface 41 from the end point 43 in the axial direction and the virtual surface coupled to the central wall surface 41, and the axial end surface 64 of the second end 60. And a hollow surface located on the inner side in the axial direction and the circumferential direction from the virtual fillet surface F2 for smoothing the corner of the ridge where the virtual surface coupled to the axial end surface 64 intersects, and the central wall surface as viewed from the axial direction. 41 in the circumferential direction.

  The second wall surface 61 has an inflection portion 62 in which the inclination with respect to the axis O in the contour line of the cross section shown in FIG. ing. Since there exists the inflection part 62, compared with the case where there is no inflection part 62, the 2nd wall surface 61 can be penetrated deeply in the circumferential direction (arrow C direction), and the elastic leg part 13 by the 2nd wall surface 61 can be penetrated. The amount of thinning can be secured.

  By providing the first wall surface 51 and the second wall surface 61 on the elastic leg portion 13 in this way, strain in the tensile direction generated in the elastic leg portion 13 can be dispersed. Dispersing the strain can reduce the maximum strain as compared with the case where the first wall surface 51 and the second wall surface 61 are not provided (in the case of virtual fillet surfaces F1 and F2), thereby improving the durability of the elastic legs 13. it can.

  The first end 50 has an axial length D1 in the projection in the circumferential direction (arrow C direction), and an axial length D of the elastic leg 13 in the projection in the circumferential direction (central wall surface 41, first wall surface 51). And the axial length of the second wall surface 61) is set to 1/6 to 1/2. That is, since D1 / D = 1/6 to 1/2 is set (D1 / D = 2/5 in the present embodiment), durability is suppressed while suppressing a decrease in the spring of the elastic leg 13. It can be improved. By setting D1 / D ≧ 1/6, it is possible to ensure the effect of improving durability, and by setting D1 / D ≦ 1/2, it is possible to suppress the spring of the elastic leg 13 from being lowered. The length D1 is a distance from the end point 42 of the first wall surface 51 closest to the center in the axial direction to the axial end surface 54 (end point 53) of the elastic leg 13.

  Similarly, in the second end portion 60, the axial length D2 in the circumferential projection is equal to the axial length D of the elastic leg 13 in the circumferential projection (the central wall surface 41, the first wall surface 51 and the second wall surface 41). The axial length of the wall surface 61 is set to 1/6 to 1/2. That is, since D2 / D = 1/6 to 1/2 is set (D2 / D = 2/5 in the present embodiment), durability is suppressed while suppressing the spring of the elastic leg 13 from being lowered. Can be improved. By setting D2 / D ≧ 1/6, it is possible to ensure the effect of improving the durability, and by setting D2 / D ≦ 1/2, it is possible to suppress a decrease in the spring of the elastic leg portion 13. The length D2 is a distance from the end point 43 of the second wall surface 61 closest to the axial center to the axial end surface 64 (end point 63) of the elastic leg 13.

  As shown in FIG. 6, the first bush 10 is set such that the length of the inner member 11 in the axial direction (arrow A direction) is larger than the length of the outer member 12 in the axial direction. The elastic leg portion 13 vulcanized and bonded to the inner member 11 and the outer member 12 has an axial length on the inner member 11 side (radially inner side) and an axial length on the outer member 12 side (radially outer side). Shorter than that. Accordingly, the spring of the first bush 10 is restricted by the elastic leg 13 on the side of the outer member 12 having a short axial length.

  Returning to FIG. 2, the first wall surface 51 viewed from the axial direction will be described. Since the second wall surface 62 is formed on the axial end surface (first end portion 60) of the elastic leg portion 13 in the same manner as the first wall surface 51, description thereof is omitted. The first wall surface 51 is formed in a curved shape so as to enter a curved shape in the circumferential direction with respect to the central wall surface 41 as viewed from the axial direction (perpendicular to FIG. 2). Therefore, it is possible to prevent the tensile strain from concentrating on a part of the first wall surface 51.

  In addition, the first wall surface 51 is opposed to the central wall surface 41 at a portion located on the inner member 11 side from the center C (center in the radial direction of the first end portion 50) in the axial direction view (viewed in the vertical direction in FIG. 2). Thus, the area entering in the circumferential direction is set to be larger than the area entering in the circumferential direction with respect to the central wall surface 41 in the portion located on the outer member 12 side from the center C. Thereby, the fall of the spring of the elastic leg part 13 (outer member 12 side) can be suppressed while dispersing the tensile strain concentrated in the vicinity of the outer member 12 of the elastic leg part 13. The center C is a midpoint of a line segment formed by a virtual imaginary line E obtained by extending the outline of the central wall surface 41 linearly when viewed from the axial direction and intersecting the outer shapes of the inner member 11 and the outer member 12. .

  Further, the first wall surface 51 has a maximum length L1 that enters the circumferential direction with respect to the central wall surface 41 when viewed from the axial direction, and is 1 with respect to the circumferential length L of the elastic leg 13 in the axial projection. It is set to / 8 to 1/2. That is, since L1 / L = 1/8 to 1/2 (1/3 in the present embodiment), durability can be improved while suppressing a decrease in the spring of the elastic leg portion 13. By setting L1 / L ≧ 1/8, it is possible to ensure the effect of improving the durability, and by setting L1 / L ≦ 1/2, it is possible to suppress a decrease in the spring of the elastic leg portion 13.

  Note that the length L is the length of an arc in which the concentric circles of the inner member 11 and the outer member 12 passing through the center C intersect with the contour in the axial projection of the elastic leg 13, and the length L1 is the length of the inner member 11 and The concentric circle of the outer member 12 is the length of the longest arc that intersects the imaginary line E and the circumferential end point 53 of the first wall surface 51 (the boundary between the first wall surface 51 and the axial end surface 54 when viewed in the axial direction).

  A load is applied to the inner member 11 of the first bush 10 configured as described above, the inner member 11 is displaced relative to the outer member 12 in the direction perpendicular to the axis, and the contact portion 17 is brought into contact with the stopper portion 15. The maximum principal strain and the static spring constant of the elastic leg 13 were determined by calculation. The calculation results will be described with reference to FIG. FIG. 7A is an isoline diagram of the maximum principal strain generated in the elastic leg 13 of the first bush 10, and FIG. 7B is an isoline diagram of the comparative example. In the comparative example, the same shape, size and material as those of the first bush 10 (hereinafter referred to as “example”) were set except that the first wall surface 51 and the second wall surface 61 were not formed on the elastic legs.

  As shown in FIGS. 7A and 7B, in the comparative example, strain concentrates on the outer member 12 side of the elastic leg 13, whereas in the embodiment, the strain can be distributed on the inner member 11 side. Was confirmed. Moreover, it was confirmed that the absolute value of distortion can be made smaller in the example than in the comparative example. As a result of the calculation, the example was able to reduce the maximum principal strain by 13% compared to the comparative example. In the example, since a part of the elastic leg portion 13 was thinned, there was a concern about a decrease in the static spring constant, but a decrease in the static spring constant could be suppressed to 4% as compared with the comparative example. Therefore, according to the present embodiment, it is apparent that the durability can be improved by dispersing the strain in the tensile direction generated in the elastic leg 13 by the first wall surface 51 and the second wall surface 61 and reducing the absolute value of the strain. Became.

  Here, it is possible to disperse the distortion of the elastic leg portion 13 by reducing the radius of the fillet formed at the ridge where the axial end surface and the circumferential end surface of the elastic leg portion 13 intersect. However, in this case, there arises a problem that the spring of the elastic leg portion is lowered. According to the present embodiment, since the spring of the elastic leg portion can be prevented from being lowered (the embodiment is only 4% lower than the comparative example), the durability is improved while the spring of the elastic leg portion is restrained from being lowered. Obviously you can.

  Next, a second embodiment will be described with reference to FIGS. In 1st Embodiment, the case where the elastic leg part 13 was arrange | positioned in V shape seeing from the axial direction was demonstrated. On the other hand, in the second embodiment, a case will be described in which the elastic legs 113 are arranged linearly when viewed from the axial direction. In addition, about the part same as 1st Embodiment, the same code | symbol is attached | subjected and the following description is abbreviate | omitted. FIG. 8 is a plan view of the vibration isolator 101 according to the second embodiment, and FIG. 9 is a cross-sectional view of the elastic leg 113 taken along the line IX-IX in FIG.

  As shown in FIG. 8, the vibration isolator 101 includes a first bush 110 and a second bush 20 and a connecting member 30 that connects the first bush 110 and the second bush 20 to each other. The engine is configured to suppress relative displacement of the engine while suppressing vibration transmission. In the present embodiment, the first bush 110 is connected to the vehicle body side (right side of FIG. 8, not shown), and the second bush 20 is connected to the engine side (left side of FIG. 8, not shown).

  The first bush 110 includes a pair of elastic legs 113 that are interposed between an inner member 11 and an outer member 12 that are attached to the vehicle body side (not shown) and are made of an elastic material (rubber-like elastic material). Yes. The pair of elastic legs 113 are arranged in a straight line when viewed from the axial direction of the inner member 11 and the outer member 12 (the direction perpendicular to the plane of FIG. 8). The elastic leg portion 113 and the stopper portions 14 and 15 are integrally formed from a rubber-like elastic body, and are vulcanized and bonded to predetermined portions of the inner member 11 and the outer member 12. The first bush 110 suppresses a tensile strain generated in the elastic leg 113 when the inner member 11 and the outer member 12 are relatively displaced so that the inner member 11 approaches the stopper parts 14 and 15. A first wall surface 151 and a second wall surface 161 (see FIG. 9) are formed on both sides of the circumferential end surface.

  As shown in FIG. 9, the elastic leg portion 113 has a first wall surface 151 and a second wall surface 161 that are coupled to the central wall surface 41. The first wall surface 151 is a recessed surface located on the inner side in the axial direction and the circumferential direction from the virtual fillet surface F1 and enters the circumferential direction from the central wall surface 41 when viewed from the axial direction. The first wall surface 151 has an inclination with respect to the axis O in the contour line of the cross section in the circumferential direction larger than the inclination with respect to the axis O of the central wall surface 41, and in the circumferential direction toward the outside in the axial direction (arrow A direction). A contour is formed in a straight line.

  The second wall surface 161 is a recessed surface located on the inner side in the axial direction and the circumferential direction from the virtual fillet surface F2, and enters the circumferential direction from the central wall surface 41 when viewed from the axial direction. The second wall surface 161 has an inclination with respect to the axis O in the contour line of the cross section in the circumferential direction larger than the inclination with respect to the axis O of the central wall surface 41, and in the circumferential direction toward the outside in the axial direction (arrow A direction). A contour is formed in a straight line.

  Since the first wall surface 151 and the second wall surface 161 are formed on both circumferential end surfaces of the elastic leg portion 113, the vibration isolator 101 has an elastic leg in both cases of acceleration traveling and deceleration traveling of the vehicle. The tensile strain generated in the portion 113 can be relaxed. Therefore, the durability of the vibration isolator 101 can be improved.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed. For example, the shapes of the inner member 11 and the elastic leg portions 13 and 113 are examples, and it is natural that various shapes can be adopted.

  In each of the above embodiments, the vibration isolator 1, 101 (so-called torque rod) in which the first bushes 10, 110 and the second bush 20 are connected by the connecting member 30 has been described, but the present invention is not necessarily limited thereto. For example, the first bushes 10 and 110 (so-called bushes) in which the inner member 11 and the outer member 12 are connected by a pair of elastic legs 13 and 113 can naturally be used as the vibration isolator.

  In each of the above-described embodiments, the case where the vibration isolator 1 or 101 is used as an engine mount that elastically supports an automobile engine has been described. However, the present invention is not necessarily limited thereto. Of course, this embodiment can be applied to a vibration isolator that suppresses vibration of an arbitrary vibrating body such as a body mount or a differential mount.

1,101 Vibration isolator 10,110 First bush (vibration isolator)
DESCRIPTION OF SYMBOLS 11 Inner member 12 Outer member 13,113 Elastic leg part 40 Center part 41 Center wall surface 50 1st edge part 51,151 1st wall surface
52, 62 inflection part
53, 63 end point 60 second end portion 61, 161 second wall surface
F1, F2 fillet surface

Claims (4)

An inner member, and a cylindrical outer member disposed on the outer peripheral side of the inner member with a gap from the inner member;
A pair of elastic legs composed of a rubber-like elastic body connecting the inner member and the outer member;
The elastic leg portion is a portion located in the center in the axial direction of the inner member and the outer member, and a central portion including a central wall surface forming an outline of the elastic leg portion viewed from the axial direction;
It has a first wall surface connected to one side of the central wall surface in the axial direction and one end surface of the elastic leg portion in the axial direction, and is connected to one side of the central portion in the axial direction. A first end,
It has a second wall surface connected to the other axial side of the central wall and the end of the other end surface of the elastic leg in the axial direction, and is connected to the other axial side of the central portion. comprises a second end that, the,
The first wall surface is more axial than the virtual fillet surface that smoothes the corner of the ridge where the virtual surface extending in the axial direction from the central wall surface and the virtual surface extending from the end point in the circumferential direction intersects the one end surface. And located inside the circumferential direction,
The second wall surface is more axial than the virtual fillet surface that smoothes the corner of the ridge where the virtual surface that extends the central wall surface in the axial direction and the virtual surface that extends the other end surface in the circumferential direction from the end point. And located inside the circumferential direction,
The first wall surface and the second wall surface are, in a cross section perpendicular to the radial direction of the outer member, two curved surfaces protruding outward in the axial direction;
An anti-vibration device comprising an inflection portion that is located between the two curved surfaces and changes the direction of the unevenness . The first wall surface and the second wall surface are the center wall surface and the end point at a portion located on the inner member side from the radial center of the first end portion and the second end portion when viewed from the axial direction. is set to be larger than the area between the first end and the and the said central wall from radial center of the second end portion at a site located in the outer member side the end point area between the The vibration isolator according to claim 1, wherein The outer member is cylindrical;
The first wall surface and the second wall surface are in a radial direction from the inner member when viewed from the axial direction in a portion located on the inner member side from the radial center of the first end portion and the second end portion. the vibration isolating apparatus according to claim 2, wherein the length of the concentrically is set to be longer the outer member between the end points and the center wall surface toward the outside. The axial length of the first end and the second end is set to 1/6 to 1/2 of the axial length of the elastic leg, respectively. Item 4. The vibration isolator according to any one of Items 1 to 3 .