Vibration isolation device

Abstract

To provide a vibration isolation device that can ensure the durability of elastic legs even when spring characteristics and durability are required in different directions. [Solution] Since the mounting angle θ1 of the first elastic leg 4 in the left-right direction is smaller than the mounting angle θ2 of the second elastic leg 5, when a relatively large load is applied in the inclination direction Da, that load is more likely to act in the shear direction of the first elastic leg 4. In other words, compression of the first elastic leg 4 between the outer member 2 and the inner member 3 can be suppressed, so that the durability of the first elastic leg 4 can be ensured even if the vertical direction in which the spring characteristics of the vibration isolation device 1 are required and the inclination direction Da in which durability is required are different directions.

Description

Technical Field

[0005]

[0001] The present invention relates to a vibration isolator, and more particularly to a vibration isolator that can ensure the durability of elastic legs even when spring characteristics and durability are required in different directions.

Background Art

[0002] For example, in Patent Document 1, there is described a vibration isolator including a cylindrical outer cylinder member 14 (outer member), an inner shaft member 12 (inner member) disposed on the inner peripheral side of the outer cylinder member 14, a pair of rubber arms 38 (first elastic legs and second elastic legs) made of an elastic body for connecting the outer peripheral surface of the inner shaft member 12 and the inner peripheral surface of the outer cylinder member 14, and buffer protrusions 48, 54 for restricting the displacement of the inner shaft member 12 when the rubber arms 38 are deformed.

[0003] When the protruding directions of the buffer protrusions 48, 54 are the vertical direction (first direction), and the direction orthogonal to the vertical direction and the axial direction of the outer cylinder member 14 is the horizontal direction (second direction), the rubber arms 38 are formed in a pair on both sides in the horizontal direction sandwiching the inner shaft member 12.

[0004] In this type of vibration isolator, it is common that the input direction of the main load (vibration) input to the inner shaft member 12 is the vertical direction. That is, since both the direction in which the rubber arms 38 are required to have predetermined spring characteristics and the direction in which durability is required are generally the vertical direction, the pair of rubber arms 38 are formed in a bilaterally symmetric shape.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the conventional technology described above, where a pair of rubber arms 38 are formed symmetrically, there is a problem that the durability of the rubber arms 38 decreases when a load is applied in a direction inclined with respect to the vertical direction. This problem will be explained with reference to Figure 2. Figure 2 is a front view of a conventional vibration isolation device 101 (viewed in the direction of axis O of the outer member 102). The arrows UD, FB, and LR in Figure 2 indicate the vertical, front-back, and left-right directions of the vibration isolation device 101, respectively.

[0007] As shown in Figure 2, the conventional vibration isolation device 101 mainly comprises a cylindrical outer member 102, an inner member 103 arranged on the inner circumference side of the outer member 102, and first elastic legs 104 and second elastic legs 105 made of an elastic material that connect the outer circumference surface of the inner member 103 and the inner circumference surface of the outer member 102.

[0008] The first elastic leg 104, connected to the right side (arrow R side) of the inner member 103, is inclined downward to the right as it approaches its outer edge, and the second elastic leg 105, connected to the left side (arrow L side) of the inner member 103, is inclined downward to the left as it approaches its outer edge. As described above, in the conventional vibration isolation device 101, the first elastic leg 104 and the second elastic leg 105 have a symmetrical shape, so the inclination angle (mounting angle) of each of these elastic legs 104 and 105 in the left-right direction is the same.

[0009] The outer member 102 and the inner member 103 are connected at two points in the circumferential direction by elastic legs 104 and 105, thereby forming an upper cutout 106 and a lower cutout 107 between the outer member 102 and the inner member 103, which are partitioned in the circumferential direction by the elastic legs 104 and 105. These cutouts 106 and 107 are through holes having openings on both sides in the axial direction O of the vibration isolation device 1.

[0010] In this conventional vibration isolation device 101, the direction in which durability of each elastic leg 104, 105 is required (i.e., the direction in which a relatively large load input is expected) may be in a direction that is inclined with respect to the vertical and horizontal directions (hereinafter referred to as "inclination direction Da"). Figure 2 illustrates the case when this inclination direction Da approaches the inclination angle of the first elastic leg 104.

[0011] When a load in the tilt direction Da is applied to the vibration isolation device 1, the first elastic leg 104 is easily compressed in the region Ra (the region enclosed by the dashed line in Figure 2) sandwiched between the outer member 102 and the inner member 103 in the tilt direction Da. In a configuration where such a compressive load easily acts on the first elastic leg 104, the durability of the first elastic leg 104 decreases. In particular, in the region Ra shown in Figure 2, the region closer to the lower edge 107 has a shorter dimension of the first elastic leg 104 (length in the tilt direction Da) compared to the upper edge 106 side, so the first elastic leg 104 is more prone to distortion due to the compressive load mentioned above.

[0012] In other words, in a configuration like the conventional vibration isolation device 101, where each elastic leg 104, 105 is formed symmetrically, there is a problem that the durability of the first elastic leg 104 decreases when the direction in which spring characteristics are required (vertical direction) and the inclination direction Da in which durability is required are different directions.

[0013] The present invention was made to solve the above-mentioned problems, and aims to provide a vibration isolation device that can ensure the durability of elastic legs even when spring characteristics and durability are required in different directions. [Means for solving the problem]

[0014] To achieve this objective, the vibration isolation device of the present invention comprises a cylindrical outer member, an inner member disposed on the inner circumference side of the outer member, elastic legs made of an elastic material connecting the outer circumference surface of the inner member and the inner circumference surface of the outer member, and a first stopper that protrudes along a first direction and restricts the relative displacement of the outer member and the inner member, wherein the elastic legs comprise a first elastic leg connected to the inner member on one side of a second direction perpendicular to the first direction and the axial direction of the outer member, and a second elastic leg connected to the inner member on the other side of the second direction, wherein the mounting direction of the first elastic leg is defined as the direction connecting the axis of the outer member and the circumferential center of the outer edge portion of the first elastic leg, and the mounting direction of the second elastic leg is defined as the direction connecting the axis and the circumferential center of the outer edge portion of the second elastic leg, the angle of the mounting direction of the first elastic leg with respect to the second direction is smaller than the angle of the mounting direction of the second elastic leg with respect to the second direction. [Effects of the Invention]

[0015] According to the vibration isolation device described in claim 1, the elastic leg comprises a first elastic leg connected to the inner member on one side (right side) of a second direction (hereinafter referred to as the "left-right direction") that is perpendicular to the first direction (hereinafter referred to as the "up-down direction") and the axial direction of the outer member, and a second elastic leg connected to the inner member on the other side (left side) of the left-right direction. The angle (acute angle) between the left-right direction and the mounting direction of the first elastic leg is smaller than the angle (acute angle) between the left-right direction and the mounting direction of the second elastic leg. Therefore, when a load is applied in a direction that is inclined with respect to the up-down direction (hereinafter referred to as the "inclination direction"), compression of the first elastic leg between the outer member and the inner member can be suppressed. Thus, even if the up-down direction, where the spring characteristics of the vibration isolation device are required, and the inclination direction, where durability is required, are different directions, the durability of the first elastic leg can be ensured.

[0016] According to the vibration isolation device described in claim 2, in addition to the effects of the vibration isolation device described in claim 1, the circumferential dimension of the outer edge portion of the first elastic leg is smaller than the circumferential dimension of the outer edge portion of the second elastic leg, so the volume of the outer edge side of the first elastic leg can be made relatively small. As a result, even when the angle (acute angle) between the left-right direction and the mounting direction of the first elastic leg is made relatively small, it is possible to suppress the spring constant of the first elastic leg in the left-right direction from becoming excessively high. Therefore, there is an effect that the vibration isolation device can be given the desired spring characteristics.

[0017] According to the vibration isolation device of claim 3, in addition to the effects of the vibration isolation device of claim 2, the dimensions of the second elastic leg in the mounting direction of the second elastic leg are larger than the dimensions of the first elastic leg in the mounting direction of the first elastic leg, so the volume of the second elastic leg can be made relatively large. This has the effect of ensuring the durability of the second elastic leg even when the second elastic leg is compressed between the outer member and the inner member by a load applied in the vertical direction.

[0018] The vibration isolation device according to claim 4 provides the following effects in addition to the effects of the vibration isolation device according to claim 1. The side surface of the inner member to which the first elastic leg is connected comprises a first side surface extending from one side in the vertical direction to the other side (from the top to the bottom), and a second side surface connected to the other end (bottom end) of the first side surface in the vertical direction and bending to the other side (left side) in the left-right direction. A groove is formed on the other side (bottom) of the inner member in the vertical direction, with both ends in the circumferential direction partitioned by the first and second elastic legs. Since the groove is formed in a position that overlaps with the entire second side surface when viewed in the vertical direction, it can more effectively suppress compression of the first elastic leg between the outer member and the inner member (second side surface) when a load in the inclined direction is applied. Therefore, it has the effect of more effectively ensuring the durability of the first elastic leg.

[0019] According to the vibration isolator described in claim 5, in addition to the effects achieved by the vibration isolator described in claim 1, the following effects are achieved. It includes a second stopper and a third stopper that protrude from the inner peripheral surface of the outer member and restrict the displacement of the inner member by contact with the first elastic leg and the second elastic leg. The distance between the first elastic leg and the second stopper in the vertical direction is narrower than the distance between the second elastic leg and the third stopper. Therefore, for example, when a load is input in the vertical direction, after the first elastic leg contacts the second stopper, the second elastic leg can be made to contact the third stopper. By thus causing the first and second elastic legs to contact the second and third stoppers in sequence, there is an effect that it is possible to suppress a rapid increase in the spring constant of the vibration isolator when they contact.

[0020] According to the vibration isolator described in claim 6, in addition to the effects achieved by the vibration isolator described in claim 5, since the cross-sectional area of the second stopper is larger than the cross-sectional area of the third stopper, the volume of the second stopper can be made relatively large. Thereby, for example, even in a configuration where the second elastic leg is made to contact the third stopper after the first elastic leg contacts the second stopper when a load is input in the vertical direction, there is an effect that the durability of the second stopper can be ensured.

Brief Description of the Drawings

[0021] [Figure 1] It is a front view of the vibration isolator in one embodiment of the present invention. [Figure 2] It is a front view of a conventional vibration isolator.

Modes for Carrying Out the Invention

[0022] Hereinafter, preferred embodiments will be described with reference to the accompanying drawings. FIG. 1 is a front view of a vibration isolator 1 in one embodiment of the present invention. In FIG. 1, the arrow directions U-D, F-B, and L-R indicate the vertical direction, front-rear direction, and left-right direction of the vibration isolator 1, respectively. However, the directions of this vibration isolator 1 do not necessarily match the directions of the vehicle to which the vibration isolator 1 is attached. Also, in FIG. 1, the vibration isolator 1 in a no-load state where no vibration (load) is input is illustrated.

[0023] As shown in FIG. 1, the vibration isolator 1 is a vibration isolation bush that elastically couples a vibration source side such as an engine, motor, or arm of a suspension mechanism of an automobile with a vibration receiving side such as a vehicle body. The vibration isolator 1 includes a cylindrical outer member 2 fixed to one of the vibration source side and the vibration receiving side, and a shaft-shaped inner member 3 is disposed on the inner peripheral side of the outer member 2. The outer member 2 and the inner member 3 are each made of a rigid material such as a steel material or an aluminum alloy.

[0024] The inner member 3 includes a fastening portion 30 having a fastening hole 30a, a pair of upper convex portions 31 and 32 protruding upward (one side in the first direction) (arrow U side) from the fastening portion 30, and a lower convex portion 33 (first stopper) protruding downward (the other side in the first direction) (arrow D side) from the fastening portion 30, and these portions 30 to 33 are integrally formed. A fastening member (not shown) such as a bolt is inserted into the fastening hole 30a of the fastening portion 30, and the inner member 3 is fixed to the other of the vibration source side and the vibration receiving side by this fastening member. In this fixed state, the axial direction O of the outer member 2 (the fastening hole 30a of the inner member 3) coincides with the longitudinal direction of the vehicle.

[0025] In the present embodiment, the upper surface 34 of the inner member 3 is a plane orthogonal to the vertical direction (first direction) (arrow U-D direction). However, the upper surface 34 of the inner member 3 may be formed as a curved surface. The upper convex portions 31 and 32 are formed in a pair at both ends in the left-right direction (second direction) (arrow L-R direction) of the upper surface 34 of the inner member 3.

[0026] Of the pair of upper convex portions 31 and 32, the right side surface of the upper convex portion 31 located on the right side (one side in the second direction) (arrow R side) is continuous with the right side surface 35 of the inner member 3, and the left side surface of the upper convex portion 32 located on the left side (the other side in the second direction) (arrow L side) is continuous with the left side surface 36 of the inner member 3.

[0027] The right side surface 35 of the inner member 3 is composed of a first side surface 35a that slopes downward to the right from its upper end to its lower end, and a second side surface 35b that bends to the left from the lower end of the first side surface 35a. The second side surface 35b slopes downward to the left from the lower end of the first side surface 35a and connects to the right side surface of the lower protrusion 33, and the left side surface 36 of the inner member 3 slopes downward to the right from its upper end to its lower end and connects to the left side surface of the lower protrusion 33.

[0028] The left and right sides 35, 36 (outer peripheral surfaces facing left and right) of the inner member 3 are connected to the inner peripheral surface of the outer member 2 by the first elastic leg 4 and the second elastic leg 5 (hereinafter collectively referred to as "elastic legs 4 and 5"). The first elastic leg 4 is connected to the right side of the inner member 3, and the second elastic leg 5 is connected to the left side of the inner member 3.

[0029] The outer member 2 and the inner member 3 are connected at two points in the circumferential direction by elastic legs 4 and 5, thereby forming an upper cutout 6 and a lower cutout 7 between the outer member 2 and the inner member 3, which are partitioned in the circumferential direction by the elastic legs 4 and 5. These cutouts 6 and 7 are through holes with openings on both sides in the axial direction O of the vibration isolation device 1. In this embodiment, the circumferential dimensions (cross-sectional area) of the upper cutout 6 are formed to be larger than those of the lower cutout 7, but the circumferential dimensions of the upper cutout 6 may be formed to be smaller than those of the lower cutout 7.

[0030] An upper stopper 8 (first stopper) protrudes upward from the upper surface 34 of the inner member 3 toward the upper curvature 6, and lower stoppers 9 and 10 protrude upward from the inner circumferential surface of the outer member 2 toward each elastic leg 4 and 5. The lower stopper 9 faces the first elastic leg 4 vertically on the right side of the lower protrusion 33, and the lower stopper 10 faces the second elastic leg 5 vertically on the left side of the lower protrusion 33.

[0031] Each elastic leg 4, 5 and the upper stopper 8 are connected to each other via an elastic membrane 11 that covers the outer circumferential surface of the inner member 3 (a pair of upper protrusions 31, 32 and a lower protrusion 33). Similarly, each elastic leg 4, 5 and the pair of lower stoppers 9, 10 are connected to each other via an elastic membrane 12 that covers the inner circumferential surface of the outer member 2.

[0032] Each of these elastic legs 4, 5, upper stopper 8, lower stoppers 9, 10, and elastic membranes 11, 12 is integrally formed from an elastic material such as rubber or thermoplastic elastomer (vulcanized and bonded to the outer member 2 and inner member 3). However, some or all of the elastic membranes 11, 12 may be omitted, and some or all of each of the elastic legs 4, 5, upper stopper 8, and lower stoppers 9, 10 may be separated from the other parts.

[0033] The upper stopper 8 and the lower protrusion 33 each protrude in the vertical direction, and before vibration is input to the vibration isolation device 1, gaps are formed between the upper stopper 8 and the inner circumferential surface (elastic membrane 12) of the outer member 2, and between the lower protrusion 33 and the inner circumferential surface of the outer member 2. In this embodiment, gaps are also formed between each elastic leg 4, 5 and the lower stoppers 9, 10 before vibration is input to the vibration isolation device 1, but pre-compression may be applied to the lower stoppers 9, 10 to fill these gaps.

[0034] When vibration is input to the vibration isolation device 1 and the inner member 3 is displaced upward relative to the outer member 2, the upper stopper 8 contacts and compresses the outer member 2 (elastic membrane 12), thereby gradually restricting the relative displacement of the inner member 3. Therefore, the spring constant of the vibration isolation device 1 can be kept low until the upper stopper 8 contacts the outer member 2, and then increased after contact.

[0035] On the other hand, if the inner member 3 is displaced downward relative to the outer member 2, each elastic leg 4, 5 comes into contact with the lower stoppers 9, 10, and the lower stoppers 9, 10 are compressed, thereby gradually restricting the relative displacement of the inner member 3. This allows the spring constant of the vibration isolation device 1 to be kept low until each elastic leg 4, 5 comes into contact with the lower stoppers 9, 10, and then increased after contact.

[0036] If the inner member 3 is displaced further downward after each elastic leg 4, 5 has contacted the lower stoppers 9, 10, the lower protrusion 33 will contact the inner circumferential surface of the outer member 2 via the elastic membranes 11, 12. This restricts excessive displacement of the inner member 3.

[0037] When the relative displacement of the inner member 3 occurs, vibrations are damped by the elastic deformation of each elastic leg 4, 5. Regarding the spring characteristics and durability associated with the elastic deformation of each elastic leg 4, 5, in this embodiment, each elastic leg 4, 5 is given predetermined spring characteristics in the vertical and horizontal directions, while the durability of each elastic leg 4, 5 is ensured in the direction inclined with respect to those directions (hereinafter referred to as "inclination direction Da"). This configuration is described below.

[0038] The inclination direction Da, where durability is required, is the direction perpendicular to the axis O direction, and is the direction in which a relatively large load input to the vibration isolation device 1 (inner member 3) is expected.

[0039] First, in Figure 1, the arc along the outer edge of the first elastic leg 4 is shown by the imaginary line V1, and the arc along the outer edge of the second elastic leg 5 is shown by the imaginary line V2. In the following explanation, the midpoint of the imaginary line V1 is defined as the circumferential center C1 of the outer edge of the first elastic leg 4, and the midpoint of the imaginary line V2 is defined as the circumferential center C2 of the outer edge of the second elastic leg 5.

[0040] Furthermore, in a view along axis O, the direction connecting the circumferential center C1 of the outer edge portion of the first elastic leg 4 with axis O is defined as the mounting direction Db of the first elastic leg 4, and in a view along axis O, the direction connecting the circumferential center C2 of the outer edge portion of the second elastic leg 5 with axis O is defined as the mounting direction Dc of the second elastic leg 5 for explanation purposes.

[0041] With this definition, the mounting direction Db of the first elastic leg 4 is inclined downward and to the right as it approaches the outer edge of the first elastic leg 4, and the mounting direction Dc of the second elastic leg 5 is inclined downward and to the left as it approaches the outer edge of the second elastic leg 5. Furthermore, the above-mentioned inclination direction Da is the direction in which the angle (acute angle) made with the mounting direction Db of the first elastic leg 4 is smaller than that made with the vertical direction (that is, the angle (acute angle) made between the inclination direction Da and the mounting direction Db of the first elastic leg 4 is smaller than the angle (acute angle) made between the vertical direction and the mounting direction Db of the first elastic leg 4).

[0042] Furthermore, if the angle (acute angle) between the left-right direction and the mounting direction Db of the first elastic leg 4 is defined as the mounting angle θ1 of the first elastic leg 4, and the angle (acute angle) between the left-right direction and the mounting direction Dc of the second elastic leg 5 is defined as the mounting angle θ2 of the second elastic leg 5, then in this embodiment, the mounting angle θ1 of the first elastic leg 4 with respect to the left-right direction (for example, 10° or more and 20° or less) is smaller than the mounting angle θ2 of the second elastic leg 5 (for example, 30° or more and 40° or less).

[0043] As a result, when a load in the inclination direction Da is applied, that load is more likely to act in the shear direction of the first elastic leg 4, thereby suppressing compression of the first elastic leg 4 between the outer member 2 and the inner member 3. Therefore, even if the vertical direction in which a predetermined spring characteristic is required for the vibration isolation device 1 and the inclination direction Da in which durability is required are different directions, the durability of the first elastic leg 4 can be ensured.

[0044] On the other hand, if the mounting angle θ1 of the first elastic leg 4 with respect to the left-right direction is made relatively small, the mounting direction Db of the first elastic leg 4 will approach a direction parallel to the left-right direction. For this reason, the spring constant of the first elastic leg 4 tends to increase with respect to loads applied in the left-right direction.

[0045] Furthermore, if the mounting angle θ2 of the second elastic leg 5 in the left-right direction is relatively large, when a load is applied in the vertical direction, the second elastic leg 5 is more easily compressed between the outer member 2 and the inner member 3 than the first elastic leg 4. As a result, the durability of the second elastic leg 5 against vertical loads tends to decrease.

[0046] In contrast, in this embodiment, the dimension L1 (arc length of virtual line V1) of the outer edge portion of the first elastic leg 4 in the circumferential direction is formed to be smaller than the dimension L2 (arc length of virtual line V2) of the outer edge portion of the second elastic leg 5 in the circumferential direction. As a result, the amount (volume) of rubber on the outer edge side of the first elastic leg 4 can be reduced, so that even when the mounting angle θ2 of the first elastic leg 4 in the left-right direction is relatively small, it is possible to suppress the spring constant of the first elastic leg 4 in the same direction from becoming excessively high. Therefore, the vibration isolation device 1 can be given the desired spring characteristics.

[0047] Furthermore, the dimension L2 of the outer edge portion of the second elastic leg 5 is larger than the dimension L1 of the first elastic leg 4, and the radial dimension L4 of the second elastic leg 5 is larger than the radial dimension L3 of the first elastic leg 4. This ensures sufficient rubber for the second elastic leg 5, so that even if the second elastic leg 5 is compressed between the outer member 2 and the inner member 3 by a vertical load, the decrease in the durability of the second elastic leg 5 can be suppressed.

[0048] Furthermore, the dimensions L1 and L2 of the outer edge portions of each elastic leg 4 and 5 in the circumferential direction are the dimensions spanning both ends of the outer edge portion of each elastic leg 4 and 5 in the circumferential direction, and the circumferential ends of the outer edge portion of each elastic leg 4 and 5 are the points where the curvature of the inner circumferential surface of the elastic membrane 12 changes. In addition, the dimensions L3 and L4 of each elastic leg 4 and 5 in the radial direction are line segments along the mounting directions Db and Dc of each elastic leg 4 and 5, and are the lengths of the line segments connecting the outer circumferential surface of the inner member 3 (right side 35 or left side 36) to the circumferential center C1 of the outer edge portion of each elastic leg 4 and 5.

[0049] In this embodiment, the inner member 3 has a configuration in which the first side surface 35a is inclined to the right (lower right) from the upper end to the lower end. However, as shown by the dashed line in Figure 1, for example, the first side surface 35a' of the inner member 3 may be inclined to the left (lower left) from the upper end to the lower end. By inclining the first side surface 35a' to the lower left, the first elastic leg 4 is less likely to be compressed between the outer member 2 and the inner member 3 when a load in the inclination direction Da is applied, thereby effectively ensuring the durability of the first elastic leg 4.

[0050] Furthermore, the lower end 40 (lower end of the imaginary line V1) of the outer edge portion of the first elastic leg 4 is located to the right of the first side surface 35a and the second side surface 35b (right side surface 35) of the inner member 3, and in a vertical view, the lower edge 7 is formed at a position that overlaps with the entire second side surface 35b. This effectively prevents the first elastic leg 4 from being compressed between the outer member 2 and the inner member 3 (second side surface 35b) when a load in the inclined direction Da is applied.

[0051] In particular, in this embodiment, even when viewed in the inclined direction Da, the lower edge 7 is formed at a position that overlaps with the entire second side surface 35b, so that when a load in the inclined direction Da is applied, compression of the first elastic leg 4 does not occur between the outer member 2 and the inner member 3. Therefore, the durability of the first elastic leg 4 can be more effectively ensured.

[0052] In this embodiment, the distance L5 between the first elastic leg 4 and the lower stopper 9 in the vertical direction is formed to be narrower than the distance L6 between the second elastic leg 5 and the lower stopper 10. Therefore, when vertical vibration is input, the first elastic leg 4 can be brought into contact with the lower stopper 9, and then the second elastic leg 5 can be brought into contact with the lower stopper 10. In this way, by bringing each elastic leg 4 and 5 into contact with the lower stoppers 9 and 10 in sequence (suppressing simultaneous contact between each elastic leg 4 and 5 with the lower stoppers 9 and 10), it is possible to suppress a rapid increase in the spring constant of the vibration isolation device 1 when each elastic leg 4 and 5 comes into contact with the lower stoppers 9 and 10 (making the rise of the load in the load-deflection curve gentler).

[0053] Thus, in this embodiment, since the first elastic leg 4 and the lower stopper 9 make contact before the second elastic leg 5 and the lower stopper 10 make contact, the frequency of contact between the first elastic leg 4 and the lower stopper 9 tends to increase, and a relatively large load tends to act on the lower stopper 9. In other words, the durability of the lower stopper 9 tends to decrease compared to the lower stopper 10.

[0054] In contrast, in this embodiment, the cross-sectional area of ​​the lower stopper 9 is formed to be larger than the cross-sectional area of ​​the lower stopper 10 in a cross-section perpendicular to the axis O. That is, since a relatively large amount of rubber is secured in the lower stopper 9, the durability of the lower stopper 9 can be ensured even if the configuration causes contact between the first elastic leg 4 and the lower stopper 9 to occur before contact between the second elastic leg 5 and the lower stopper 10.

[0055] Although the present invention has been described above based on the above embodiments, it can be easily inferred that the present invention is not limited in any way to the above embodiments, and that various modifications and improvements are possible without departing from the spirit of the present invention.

[0056] In the above embodiment, the case where the outer member 2 is cylindrical was described, but the outer member 2 may also be elliptical or polygonal. Also, in the above embodiment, a detailed description of the fastening hole 30a of the inner member 3 was omitted, but the fastening hole 30a may be a female threaded hole into which the fastening member is screwed, or it may be an insertion hole (through hole) into which the fastening member is inserted.

[0057] In the above embodiment, the case in which the first side surface 35a of the inner member 3 is inclined to the right from the upper end to the lower end was described, but it is not necessarily limited to this. For example, the first side surface 35a of the inner member 3 may be inclined to the left from the upper end to the lower end, or it may extend in a substantially straight line in the vertical direction.

[0058] In other words, the overall shape of the outer surface of the inner member 3, including the right side surface 35 of the inner member 3, is not limited to the above-described form and can be changed as appropriate. Therefore, for example, some or all of the upper protrusions 31, 32 and lower protrusions 33 of the inner member 3 may be omitted, or other protrusions or recesses may be formed on the inner member 3 in addition to, or in place of, those protrusions 31-33.

[0059] In the above embodiment, the case where the dimension L1 of the outer edge portion of the first elastic leg 4 in the circumferential direction is smaller than the dimension L2 of the outer edge portion of the second elastic leg 5 was described, but it is not necessarily limited to this. For example, the dimension L1 of the outer edge portion of the first elastic leg 4 may be larger than the dimension L2 of the outer edge portion of the second elastic leg 5, or their dimensions L1 and L2 may be the same.

[0060] In the above embodiment, the elastic membrane 12 is connected to both circumferential ends of the outer edge portions of each elastic leg 4, 5, and in this case, the circumferential ends of the outer edge portions of each elastic leg 4, 5 are described as points where the curvature of the inner circumferential surface of the elastic membrane 12 changes. In contrast, for example, in a configuration in which the elastic membrane 12 is omitted, the boundary between the inner circumferential surface of the outer member 2 and both circumferential ends of each elastic leg 4, 5 corresponds to "both circumferential ends of the outer edge portions of each elastic leg 4, 5".

[0061] In the above embodiment, the case where the dimension L4 of the second elastic leg 5 is larger than the dimension L3 of the first elastic leg 4 in the radial direction was described, but this is not necessarily the only case. For example, the dimension L4 of the second elastic leg 5 may be smaller than the dimension L3 of the first elastic leg 4 in the radial direction, or their dimensions L3 and L4 may be the same.

[0062] In the above embodiment, the case was described in which the lower end 40 of the outer edge portion of the first elastic leg 4 is located to the right of the first side surface 35a and the second side surface 35b (right side surface 35) of the inner member 3, but it is not necessarily limited to this. For example, the lower end 40 of the outer edge portion of the first elastic leg 4 may be located to the left of the first side surface 35a and the second side surface 35b (right side surface 35) of the inner member 3.

[0063] In the above embodiment, an upper stopper 8 and a lower projection 33 that protrude from the outer circumferential surface of the inner member 3 toward the outer member 2 were given as examples of a stopper (first stopper) that protrudes along the vertical direction to restrict the displacement of the inner member 3, but the embodiment is not necessarily limited to this. For example, one or both of the upper stopper 8 and the lower projection 33 may be omitted, and a stopper equivalent to the upper stopper 8 and the lower projection 33 (a first stopper that protrudes along the vertical direction) may be made to protrude from the inner circumferential surface of the outer member 2 toward the inner member 3.

[0064] In the above embodiment, the case where the distance L5 between the first elastic leg 4 and the lower stopper 9 in the vertical direction is smaller than the distance L6 between the second elastic leg 5 and the lower stopper 10 was described, but it is not necessarily limited to this. For example, the distance L5 between the first elastic leg 4 and the lower stopper 9 in the vertical direction may be larger than the distance L6 between the second elastic leg 5 and the lower stopper 10, or the distances L5 and L6 may be the same. Also, one or both of the lower stoppers 9 and 10 may be omitted.

[0065] In the above embodiment, the case was described in which the cross-sectional area of ​​the lower stopper 9 is formed to be larger than the cross-sectional area of ​​the lower stopper 10 in a cross-section perpendicular to the axis O, but it is not necessarily limited to this. For example, the cross-sectional area of ​​the lower stopper 9 may be smaller than the cross-sectional area of ​​the lower stopper 10, or their cross-sectional areas may be the same. [Explanation of symbols]

[0066] 1. Vibration isolation device 2 Outer member 3. Inner member 33 Lower protrusion (first stopper) 35 Side view of the inner member 35a 1st side 35b 2nd side 4. First elastic leg (elastic leg) 5. Second elastic leg (elastic leg) 7. Lower part (suguri) 8. Upper stopper (first stopper) 9. Lower stopper (second stopper) 10. Lower stopper (3rd stopper) C1 Circumferential center of the outer edge portion of the first elastic leg C2 Circumferential center of the outer edge portion of the second elastic leg Db Mounting direction of the first elastic leg Dc Mounting direction of the second elastic leg Circumferential dimensions of the outer edge portion of the first elastic leg L1 Circumferential dimensions of the outer edge portion of the second elastic leg L2 Dimensions of the first elastic leg L3 in the mounting direction Dimensions of the L4 second elastic leg in the mounting direction L5 Distance between the first elastic leg and the second stopper L6 Distance between the second elastic leg and the third stopper O-axis

Claims

1. It comprises a cylindrical outer member, an inner member disposed on the inner circumference side of the outer member, elastic legs made of an elastic material connecting the outer surface of the inner member and the inner surface of the outer member, and a first stopper that protrudes along a first direction and restricts the relative displacement of the outer member and the inner member, The elastic leg comprises a first elastic leg connected to the inner member on one side in a second direction perpendicular to the first direction and the axial direction of the outer member, and a second elastic leg connected to the inner member on the other side in the second direction. A vibration isolation device characterized in that, when the direction connecting the axis of the outer member and the circumferential center of the outer edge portion of the first elastic leg is defined as the mounting direction of the first elastic leg, and the direction connecting the axis and the circumferential center of the outer edge portion of the second elastic leg is defined as the mounting direction of the second elastic leg, the angle of the mounting direction of the first elastic leg with respect to the second direction is smaller than the angle of the mounting direction of the second elastic leg with respect to the second direction.

2. The vibration isolation device according to claim 1, characterized in that the circumferential dimension of the outer edge portion of the first elastic leg is smaller than the circumferential dimension of the outer edge portion of the second elastic leg.

3. The vibration isolation device according to claim 2, characterized in that the dimensions of the second elastic leg in the mounting direction of the second elastic leg are larger than the dimensions of the first elastic leg in the mounting direction of the first elastic leg.

4. The side surface of the inner member to which the first elastic leg is connected comprises a first side surface extending from one side in the first direction to the other side, and a second side surface connected to the other end of the first side surface in the first direction and bending toward the other side in the second direction. On the other side of the inner member in the first direction, a groove is formed where both ends in the circumferential direction are demarcated by the first elastic leg and the second elastic leg. The vibration isolation device according to claim 1, characterized in that the aforementioned trim is formed at a position that overlaps with the entire second side surface in the first viewing direction.

5. The outer member is provided with a second stopper and a third stopper that protrude from the inner circumferential surface and restrict the displacement of the inner member by contact with the first elastic leg and the second elastic leg, The vibration isolation device according to claim 1, characterized in that the distance between the first elastic leg and the second stopper in the first direction is narrower than the distance between the second elastic leg and the third stopper in the first direction.

6. The vibration isolation device according to claim 5, characterized in that the cross-sectional area of ​​the second stopper is larger than the cross-sectional area of ​​the third stopper.

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