Anti-vibration device

Abstract

Provided is an anti-vibration device capable of sufficiently reducing resonance magnification while suppressing reduction in weight and increase in dynamic magnification.　This anti-vibration device (1) is provided with a first attachment member (T1), a second attachment member (T2), and a ring-shaped mass member (F) that is connected to the first attachment member and the second attachment member via an elastic body part (B). The elastic body part includes a first elastic member (B1) that is connected at one end to the mass member and that extends on or near a first input / output shaft line (Q1), and a second elastic member (B2) that is connected at one end to the mass member and that extends on or near a second input / output shaft line (Q2). The end of the first elastic member on the mass member side and the end of the second elastic member on the mass member side are at different positions from each other, the center of gravity (FG) of the mass member is offset in a second input / output axial direction (Q2D) with respect to an input / output point (J), which is the intersection of the first input / output shaft line and the second input / output shaft line, and the second elastic member is composed of an elastic material having a higher damping force than the first elastic member.

Description

Anti-vibration device

[0001] The present invention relates to an anti-vibration device.

[0002] It is generally known that vibration isolation devices equipped with spring elements (elastic bodies) and mass elements (mass bodies) experience a resonance phenomenon at a specific vibration frequency (resonance frequency), causing the absolute spring constant to rise sharply and resulting in a deterioration in vibration absorption performance. While using high-damping rubber as the elastic body to suppress resonance is one option, high-damping rubber generally has a high dynamic ratio (absolute spring constant / static spring constant), which may result in a deterioration in ride comfort when the vibration isolation device is used in a vehicle, for example. Therefore, it is also known to further provide a dynamic damper consisting of a spring member and a mass member in the vibration isolation device to reduce the resonance ratio in the above-mentioned resonance phenomenon. For example, Patent Document 1 discloses providing a dynamic damper on the rod body of a torque rod.

[0003] WO02 / 42662A1

[0004] However, it was found that in order for the dynamic damper to sufficiently reduce the resonance magnification (resonance suppression) while suppressing the increase in dynamic magnification, the mass of the mass member of the dynamic damper must be significantly increased, which may lead to an increase in the weight of the entire device.

[0005] SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an anti-vibration device that can sufficiently reduce the resonance magnification while achieving weight reduction and suppressing an increase in the dynamic magnification.

[0006] [1] A vibration-damping device comprising: a first mounting member configured to be attached to one of a vibration generating unit and a vibration receiving unit; a second mounting member configured to be attached to the other of the vibration generating unit and the vibration receiving unit and spaced apart from the first mounting member; an elastic body portion; and a mass member connected to the first mounting member and the second mounting member via the elastic body portion and having a ring-shaped configuration in whole or in part, wherein the elastic body portion comprises one or more first elastic members connected to the mass member at one end and extending on or near a predetermined first input / output axis when viewed in the axial direction of the mass member; and one or more second elastic members connected to the first elastic member and extending on or near a predetermined second input / output axis as viewed in the mass member axial direction, wherein an end of the first elastic member on the mass member side and an end of the second elastic member on the mass member side are located at different positions in the circumferential direction of the mass member, and as viewed in the mass member axial direction, the center of gravity of the mass member is offset in the second input / output axis direction parallel to the second input / output axis with respect to an input / output point that is an intersection of the first input / output axis and the second input / output axis, and the second elastic members are made of an elastic material having a higher damping force than the first elastic members. This makes it possible to sufficiently reduce the resonance magnification while achieving weight reduction and suppressing an increase in dynamic magnification.

[0007] [2] The vibration-damping device according to [1], wherein a first input / output axis direction parallel to the first input / output axis as viewed in the axial direction of the mass member is the direction of a main vibration input to the vibration-damping device, thereby more reliably achieving both resonance suppression and low dynamic magnification.

[0008] [3] The vibration-damping device according to [1] or [2], comprising one mass member, two first mounting members arranged on both sides of the mass member in the axial direction, and a second mounting member arranged between the two first mounting members in the axial direction of the mass member and spaced apart from the two first mounting members, thereby achieving good vibration balance.

[0009] [4] The vibration-damping device according to [3], wherein the two first mounting members are each connected to the mass member via one of the first elastic members and one of the second elastic members, and the second mounting member is connected to the mass member via only one of the first elastic members, thereby making it possible to make it difficult for vibrations in the second input / output axis direction to be transmitted to the vibration receiving part.

[0010] [5] The vibration-damping device according to [3], wherein the two first mounting members and the two second mounting members are connected to the mass member via one of the first elastic members and one of the second elastic members, thereby further enhancing the resonance suppression effect.

[0011] [6] The anti-vibration device according to any one of [1] to [5], wherein the first input / output axis and the second input / output axis are perpendicular to each other when viewed in the axial direction of the mass member. This makes it possible to more appropriately exert the effects of the anti-vibration device for a vehicle when the anti-vibration device is mounted on a vehicle with the first input / output axis direction being the longitudinal direction of the vehicle and the second input / output axis direction being the vertical direction of the vehicle.

[0012] [7] The vibration-damping device according to [1] or [2], wherein the first mounting member is connected to the mass member via any one of the first elastic members and any one of the second elastic members, and the second mounting member is connected to the mass member via only any one of the first elastic members, thereby making it possible to make it difficult for vibrations in the second input / output axis direction to be transmitted to the vibration receiving part.

[0013] [8] The vibration-damping device according to [1] or [2], wherein the first mounting member and the second mounting member are connected to the mass member via one of the first elastic members and one of the second elastic members, respectively, thereby further enhancing the resonance suppression effect.

[0014] [9] The vibration-damping device according to claim [7] or [8], wherein an end portion of the first elastic member connected to the first mounting member that faces the first mounting member and an end portion of the second elastic member connected to the first mounting member that faces the first mounting member are positioned at substantially the same position in the axial direction of the mass member, thereby more effectively achieving both resonance suppression and low dynamic magnification.

[0015]

[10] The vibration-damping device according to [8], wherein an end portion of the first elastic member connected to the second mounting member that faces the second mounting member and an end portion of the second elastic member connected to the second mounting member that faces the second mounting member are positioned at substantially the same position in the axial direction of the mass member, thereby more effectively achieving both resonance suppression and low dynamic magnification.

[0016]

[11] An anti-vibration device according to any one of [1] to

[10] , wherein when vibration is input to the anti-vibration device in the direction of a first input / output axis parallel to the first input / output axis when viewed in the axial direction of the mass member, the center of gravity of the mass member rotates on an elliptical locus when viewed in the axial direction of the mass member.

[0017] According to the present invention, it is possible to provide an anti-vibration device that can sufficiently reduce the resonance magnification while achieving weight reduction and suppressing an increase in the dynamic magnification.

[0018] 1 is a side view schematically showing a vibration damping device according to a first embodiment of the present invention, as viewed from one side in the axial direction of the mass member (as viewed in the axial direction of the mass member). FIG. 2 is a perspective view schematically showing the vibration damping device of FIG. 1 as viewed obliquely. FIG. 3 is a plan view schematically showing the vibration damping device of FIG. 1 as viewed from a first side in the second input / output axial direction toward a second side in the second input / output axial direction. FIG. 4 is a perspective view schematically showing a vibration damping device according to a second embodiment of the present invention, as viewed obliquely. FIG. 5 is a plan view schematically showing the vibration damping device of FIG. 4 as viewed from a first side in the second input / output axial direction toward a second side in the second input / output axial direction. FIG. 6 is a perspective view schematically showing the vibration damping device of FIG. 6 as viewed obliquely. FIG. 7 is an explanatory diagram for explaining an overview of the operating principle of the vibration damping device according to each embodiment of the present invention. FIG. 8 is an explanatory diagram for providing a supplementary explanation of the elliptical locus in FIG. 9. FIG. 9 is an explanatory diagram for explaining in detail the operating principle of the vibration damping device according to each embodiment of the present invention. It is to be understood that the present invention is not limited to the above embodiment, and various changes and modifications may be made without departing from the spirit and scope of the present invention.

[0019] The vibration-damping device of the present invention can be used as various types of vibration-damping devices, but is particularly suitable for use as a vibration-damping device for vehicles, and is particularly suitable for use in devices where the vibration input direction is basically fixed to one direction, such as torque rods and motor mounts for electric vehicles.

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an anti-vibration device according to the present invention will be described below with reference to the drawings.

[0021] FIGS. 1 to 3 are drawings that schematically show an anti-vibration device 1 according to a first embodiment of the present invention. FIG. 1 is a side view that schematically shows the anti-vibration device 1 according to the first embodiment of the present invention as viewed from one side in the mass member axial direction FOD (as viewed in the mass member axial direction). FIG. 2 is a perspective view that schematically shows the anti-vibration device 1 of FIG. 1 as viewed obliquely. FIG. 3 is a plan view that schematically shows the anti-vibration device 1 of FIG. 1 as viewed from the first side Q2D1 in the second input / output axial direction toward the second side Q2D2 in the second input / output axial direction. FIGS. 4 and 5 are drawings that schematically show an anti-vibration device 1 according to a second embodiment of the present invention. FIG. 4 is a perspective view that schematically shows the anti-vibration device 1 according to the second embodiment of the present invention as viewed obliquely. FIG. 5 is a plan view that schematically shows the anti-vibration device 1 of FIG. 4 as viewed from the first side Q2D1 in the second input / output axial direction toward the second side Q2D2 in the second input / output axial direction. The appearance of the vibration damping device 1 according to the second embodiment when viewed in the axial direction of the mass member is the same as that shown in FIG. 6. FIGS. 6 and 7 are drawings that schematically show a vibration damping device 1 according to a third embodiment of the present invention. FIG. 6 is a side view that schematically shows the vibration damping device 1 according to the third embodiment of the present invention as viewed from one side in the axial direction FOD of the mass member (as viewed in the axial direction of the mass member). FIG. 7 is a perspective view that schematically shows the vibration damping device 1 of FIG. 6 as viewed obliquely. For ease of explanation, these embodiments will be described in parallel below. Unless otherwise specified, the matters described below can be applied to each of the examples (each embodiment and their modified examples) described in this specification.

[0022] In this specification, when describing the structure of the vibration isolation device 1, for convenience, unless otherwise specified, the description will be made of the structure when no input is applied to the vibration isolation device 1 and the vibration isolation device 1 is stationary and in its normal state (natural state), as shown in each of Figures 1 to 7.

[0023] As shown in FIGS. 1 to 7, in each embodiment of the present invention, the vibration isolator 1 includes a plurality of mounting members T1, T2, an elastic body portion B, and one mass member F.

[0024] The vibration-damping device 1 includes one or more first mounting members T1 and one or more second mounting members T2 as mounting members T1 and T2, respectively. The mounting members T1 and T2 are preferably made of rigid bodies. The first mounting member T1 is configured to be attached to one of the vibration generating unit and the vibration receiving unit by fastening or the like. The second mounting member T2 is configured to be attached to the other of the vibration generating unit and the vibration receiving unit by fastening or the like. In this example, the vibration-damping device 1 includes the first mounting member T1 attached to the vibration generating unit and the second mounting member T2 attached to the vibration receiving unit. The vibration generating unit is configured to input vibrations to the vibration-damping device 1, such as an engine in a vehicle. The vibration receiving unit is configured to receive vibrations output from the vibration-damping device 1, such as a vehicle body. The first mounting member T1 and the second mounting member T2 are configured separately from each other and are spaced apart (separated) from each other. 1 to 7, the vibration isolation device 1 includes two first mounting members T1 and one second mounting member T2. When the vibration isolation device 1 includes multiple first mounting members T1, the configurations of the first mounting members T1 are the same unless otherwise specified, and the matters described in this specification regarding the first mounting members T1 can be applied to each of the first mounting members T1. When the vibration isolation device 1 includes multiple second mounting members T2, the configurations of the second mounting members T2 are the same unless otherwise specified, and the matters described in this specification regarding the second mounting members T2 can be applied to each of the second mounting members T2.

[0025] The first mounting member T1 has a connecting portion T1c connected to the elastic body portion B, and a mounting portion T1t configured to be attached to one of the vibration generating portion and the vibration receiving portion by fastening, etc. The second mounting member T2 has a connecting portion T2c connected to the elastic body portion B, and a mounting portion T2t configured to be attached to the other of the vibration generating portion and the vibration receiving portion by fastening, etc.

[0026] When the vibration-damping device 1 includes a plurality of first mounting members T1, the first mounting members T1 may be configured separately from one another as in the embodiments of Figures 1 to 5, or may be configured integrally with one another by, for example, connecting the respective mounting portions T1t to one another as in the embodiments of Figures 6 to 7. When the vibration-damping device 1 includes a plurality of second mounting members T2, although not shown in the drawings, the second mounting members T2 may be configured separately from one another or may be configured integrally with one another by, for example, connecting the respective mounting portions T2t to one another.

[0027] The mass member F is connected to the first mounting member T1 and the second mounting member T2 via the elastic body portion B. The mass member F is preferably made of a rigid body. The mass member F has a ring-like shape, in whole or in part. In each of the embodiments shown in FIGS. 1 to 7, the mass member F has a ring-like shape (i.e., the entire ring-like shape). However, the mass member F may have a ring-like shape in part (e.g., a circumferential portion). Furthermore, the ring-like shape of the mass member F in whole or in part is a circular ring-like shape in each of the embodiments shown in FIGS. 1 to 7, but may be any ring-like shape other than a circular ring-like shape.

[0028] In this specification, for the sake of convenience, the central axis of the ring-shaped mass member F, which constitutes all or a part of the mass member F, is referred to as the "mass member axis (FO)", the direction parallel to the mass member axis (FO) is referred to as the "mass member axial direction (FOD)", the side of the mass member F farther from the center of the mass member F in the mass member axial direction (FOD) is referred to as the "mass member axial outer side", the side of the mass member axial direction (FOD) closer to the center of the mass member F is referred to as the "mass member axial inner side", the direction perpendicular to the mass member axis (FO) is referred to as the "mass member axial direction", the side closer to the mass member axis (FO) in the mass member axial direction is referred to as the "mass member inner peripheral side", the side farther from the mass member axis (FO) in the mass member axial direction is referred to as the "mass member outer peripheral side", the circumferential direction centered on the mass member axis (FO) is referred to as the "mass member circumferential direction", and the radial direction centered on the mass member axis (FO) is referred to as the "mass member radial direction".

[0029] Furthermore, in the vibration damping device 1, a predetermined first input / output axis Q1 and a predetermined second input / output axis Q2 are defined when the vibration damping device 1 is viewed from either side of the mass member axial direction FOD (when viewed in the mass member axial direction) ( FIGS. 1 and 6 ). The first input / output axis Q1 and the second input / output axis Q2 are each defined when viewed in the mass member axial direction and are fixed to the vibration damping device 1. The first input / output axis Q1 and the second input / output axis Q2 do not coincide with each other. The first input / output axis Q1 and the second input / output axis Q2 are each parallel to the mass member axial direction. When viewed in the mass member axial direction, the first input / output axis Q1 and the second input / output axis Q2 intersect with each other. In each of the embodiments shown in FIGS. 1 to 7 , when viewed in the mass member axial direction, the first input / output axis Q1 and the second input / output axis Q2 are perpendicular to each other.

[0030] For convenience, in this specification, as indicated by arrows in each drawing, a direction parallel to the first input / output axis (Q1) is referred to as the "first input / output axial direction (Q1D)," one side of the first input / output axial direction (Q1D) is referred to as the "first input / output axial direction first side (Q1D1)," and the other side of the first input / output axial direction (Q1D) is referred to as the "first input / output axial direction second side (Q1D2)." Also, a direction parallel to the second input / output axis (Q2) is referred to as the "second input / output axial direction (Q2D)," one side of the second input / output axial direction (Q2D) is referred to as the "second input / output axial direction first side (Q2D1)," and the other side of the second input / output axial direction (Q2D) is referred to as the "second input / output axial direction second side (Q2D2)."

[0031] For example, the vibration isolation device 1 may be oriented in use such that the mass member axial direction FOD is in the left-right direction of the vehicle, the first input-output axial direction Q1D is in the front-to-rear direction of the vehicle, and the second input-output axial direction Q2D is in the up-down direction of the vehicle. However, the vibration isolation device 1 may be oriented in any direction in use.

[0032] The elastic body portion B includes one or more first elastic members B1 and one or more second elastic members B2. In each of the embodiments shown in FIGS. 1 to 7, the first elastic members B1 and the second elastic members B2 are configured separately from each other. In the embodiment shown in FIGS. 1 to 3, the elastic body portion B includes three first elastic members B1 and two second elastic members B2. In each of the embodiments shown in FIGS. 4 to 7, the elastic body portion B includes three first elastic members B1 and three second elastic members B2. When the elastic body portion B includes multiple first elastic members B1, the configuration of each first elastic member B1 is similar unless otherwise specified, and the matters described in this specification regarding the first elastic member B1 can be applied to each first elastic member B1. When the elastic body portion B has multiple second elastic members B2, unless otherwise specified, the configuration of each second elastic member B2 is similar, and the matters described in this specification regarding the second elastic member B2 can be applied to each second elastic member B2.

[0033] The first elastic member B1 extends on or near the first input / output axis Q1 when viewed in the mass member axial direction. Consequently, the first elastic member B1 extends substantially in the first input / output axis direction Q1D when viewed in the mass member axial direction. In each of the embodiments shown in FIGS. 1 to 5, the first elastic member B1 extends on the first input / output axis Q1 when viewed in the mass member axial direction (FIG. 1). In the embodiment shown in FIGS. 6 and 7, the first elastic member B1 extends near the first input / output axis Q1 when viewed in the mass member axial direction (FIG. 6). The second elastic member B2 extends on or near the second input / output axis Q2 when viewed in the mass member axial direction. Consequently, the second elastic member B2 extends substantially in the second input / output axis direction Q2D when viewed in the mass member axial direction. In each of the embodiments shown in Figures 1 to 5, the second elastic member B2 extends on the second input / output axis Q2 when viewed in the axial direction of the mass member (Figure 1). In the embodiment shown in Figures 6 and 7, the second elastic member B2 extends near the second input / output axis Q2 when viewed in the axial direction of the mass member (Figure 6). Here, the expression "extending near the first input / output axis Q1" when viewed in the mass member axial direction means that, when the first elastic member B1 does not extend on the first input / output axis Q1 when viewed in the mass member axial direction, at least a portion of the first elastic member B1 passes on the first input / output axis Q1 or at a position separated from the first input / output axis Q1 by a distance not exceeding half the length of the first elastic member B1 (the length of a line segment connecting the circumferential center of the mass member of the mass member side end B1F of the first elastic member B1 and the center of the mounting member side end B1T of the first elastic member B1), and the acute angle formed by the line connecting the circumferential center of the mass member of the mass member side end B1F of the first elastic member B1 and the center of the mounting member side end B1T of the first elastic member B1 with respect to the first input / output axis Q1 is less than 45° (preferably 30° or less, more preferably 10° or less). The meaning of "the second elastic member B2 extending in the vicinity of the second input / output axis Q2" when viewed in the axial direction of the mass member is the same as above. In other words, for the vibration damping device 1 according to each embodiment of the present invention, the first input / output axis Q1 and the second input / output axis Q2 that satisfy the above-mentioned conditions can be defined and fixed to the vibration damping device 1.

[0034] The first elastic member B1 has one end B1F connected to the mass member F. The other end B1T of the first elastic member B1 is connected to the connecting portions T1c, T2c of the first mounting member T1 or the second mounting member T2. The second elastic member B2 has one end B2F connected to the mass member F. The other end B2T of the second elastic member B2 is connected to the connecting portions T1c, T2c of the first mounting member T1 or the second mounting member T2.

[0035] 1 to 7, the first elastic member B1 and the second elastic member B2 (and thus the elastic body portion B) are each located on the inner circumferential side of the mass member F. Also, in each of the embodiments in FIGS. 1 to 7, the connecting portions T1c and T2c of the first mounting member T1 and the second mounting member T2 are each located on the inner circumferential side of the mass member F.

[0036] In each of the embodiments shown in FIGS. 1 to 7 , the end B1F of the first elastic member B1 on the mass member F side is located on the first side Q1D1 in the first input / output axial direction relative to the end B1T on the mounting member T1, T2 side. The end B1T of the first elastic member B1 on the mounting member T1, T2 side is connected to the first side Q1D1 in the first input / output axial direction of the connecting portion T1c, T2c of the first mounting member T1 or the second mounting member T2. Furthermore, the end B2F of the second elastic member B2 on the mass member F side is located on the first side Q2D1 in the second input / output axial direction relative to the end B2T on the mounting member T1, T2 side. The end B2T of the second elastic member B2 on the mounting member T1, T2 side is connected to the first side Q2D1 in the second input / output axial direction of the connecting portion T1c, T2c of the first mounting member T1 or the second mounting member T2.

[0037] The end B1F of the first elastic member B1 on the mass member F side and the end B2F of the second elastic member B2 on the mass member F side are located at different positions in the circumferential direction of the mass members. In each of the embodiments shown in FIGS. 1 to 7 , when viewed in the axial direction of the mass members, the end B1F of the first elastic member B1 on the mass member F side is located on ( FIG. 1 ) or in the vicinity ( FIG. 6 ) of the first input / output axis Q1, and the end B2F of the second elastic member B2 on the mass member F side is located on ( FIG. 1 ) or in the vicinity ( FIG. 6 ) of the second input / output axis Q2. When viewed in the axial direction of the mass members, the end B1F of the first elastic member B1 on the mass member F side is connected to a portion of the inner peripheral surface of the mass member F on the first side Q1D1 in the first input / output axis direction, and the end B2F of the second elastic member B2 on the mass member F side is connected to a portion of the inner peripheral surface of the mass member F on the first side Q2D1 in the second input / output axis direction.

[0038] When viewed in the mass member axial direction, the center of gravity FG of the mass member F (indicated by a star mark in FIGS. 1, 6, etc.) is offset in the second input / output axial direction Q2D from the input / output point J ( FIGS. 1 and 6 ). In each of the embodiments shown in FIGS. 1 to 7 , when viewed in the mass member axial direction, the center of gravity FG of the mass member F is offset toward the second side Q2D2 in the second input / output axial direction from the input / output point J. The input / output point J is the intersection of the first input / output axis Q1 and the second input / output axis Q2D from the mass member axial direction. In each of the embodiments shown in FIGS. 1 to 7 , the input / output point J is located on the inner peripheral side of the mass member F from the mass member axial direction. In each of the embodiments shown in FIGS. 1 to 7 , the connecting portions T1c, T2c of the first mounting member T1 and the second mounting member T2 are arranged at intervals from each other along the mass member axial direction FOD. The input / output point J is located on the connecting portions T1c and T2c of the first and second mounting members T1 and T2, respectively, when viewed in the axial direction of the mass members. More specifically, in each of the embodiments shown in Figures 1 to 7, the input / output point J is located on the center point of the connecting portions T1c and T2c of the first and second mounting members T1 and T2, respectively, when viewed in the axial direction of the mass members.

[0039] The elastic body portion B (and thus the first elastic member B1 and the second elastic member B2) may be made of any elastic material, such as rubber or resin. The second elastic member B2 is made of an elastic material with a higher damping force than the first elastic member B1. Here, the "damping force" of the elastic body portion B can be evaluated, for example, by tan δ (loss tangent). The first elastic member B1, which has a relatively low damping force and extends substantially in the first input / output axial direction Q1D, can be said to primarily function to support the mounting members T1 and T2 in the first input / output axial direction Q1D. On the other hand, the second elastic member B2, which has a relatively high damping force and extends substantially in the second input / output axial direction Q2D, can be said to primarily function to absorb vibrations in the second input / output axial direction Q2D by converting the vibrations into thermal energy.

[0040] As described above, in the vibration-damping device 1 according to each embodiment, the end B1F of the first elastic member B1 on the mass member F side and the end B2F of the second elastic member B2 on the mass member F side are located at different positions in the circumferential direction of the mass member. When viewed in the axial direction of the mass member, the center of gravity FG of the mass member F is offset in the second input / output axial direction Q2D from the input / output point J. The second elastic member B2 is made of an elastic material with a higher damping force than the first elastic member B1. Generally, the higher the damping force (e.g., tan δ) of an elastic material, the higher the dynamic magnification ratio. This makes the elastic material less suitable for use in a vibration-damping device from the standpoint of ride comfort, etc. In this regard, in each embodiment, the second elastic member B2 is made of an elastic material with a higher damping force than the first elastic member B1. Therefore, the damping force and therefore the dynamic magnification ratio of the entire elastic body portion B can be kept low compared to when both the first elastic member B1 and the second elastic member B2 are made of an elastic material with a high damping force. In each embodiment, the end B1F of the first elastic member B1 on the mass member F side and the end B2F of the second elastic member B2 on the mass member F side are located at different positions in the circumferential direction of the mass member, and the center of gravity FG of the mass member F is offset in the second input / output axial direction Q2D from the input / output point J as viewed in the mass member axial direction. This makes it possible to keep the weight of the mass member F low and, as described above, to keep the damping force of the elastic body portion B as a whole low, and thereby the dynamic magnification ratio, while also sufficiently reducing the resonance magnification ratio (the ratio of the spring constant K at the resonance frequency to the spring constant K near 0 Hz). More specifically, because the center of gravity FG of the mass member F is offset in the second input / output axial direction Q2D from the input / output point J as viewed in the mass member axial direction, when vibration is input to the vibration isolation device 1, a torque is generated to rotate the center of gravity FG of the mass member F along an elliptical locus FH ( FIG. 8 ), which will be described later.Furthermore, because the end B1F of the first elastic member B1 on the mass member F side and the end B2F of the second elastic member B2 on the mass member F side are located at different positions in the circumferential direction of the mass members, when vibration is input to the vibration-damping device 1, the mass member F tends to move substantially parallel to a line connecting the end B1F of the first elastic member B1 on the mass member F side and the end B2F of the second elastic member B2 on the mass member F side. This allows the vibration input to the vibration-damping device 1 to be distributed into vibration in the first input / output axial direction Q1D and vibration in the second input / output axial direction Q2D. Consequently, the elastic body B (particularly the second elastic member B2) can effectively convert the vibration into thermal energy and absorb the vibration. In this way, the vibration-damping device 1 of each embodiment mediates rotational motion between two translational kinetic energies with different vectors, allowing them to interact with each other. Furthermore, the vibration-damping device 1 of each embodiment uses a single mass member F to form a dynamic damper. Furthermore, the vibration isolation device 1 of each embodiment can achieve a low dynamic magnification while simultaneously using the resonance suppression function of a high-damping elastic material. In this way, it is possible to sufficiently reduce the resonance magnification while reducing the weight and suppressing an increase in the dynamic magnification.

[0041] Although the effects of the vibration isolation device 1 are as described above, the specific operating principle of the vibration isolation device 1 is not completely clear and is thought to be probably as follows. The operating principle of the vibration isolation device 1 will be considered below with reference to Figures 8 to 11. Note that Figures 8 to 11 illustrate the vibration isolation device 1 of the embodiment in Figures 6 to 7 as an example, but the following operating principle also applies to each of the embodiments in Figures 1 to 5. The vibration isolation device 1 illustrated in Figures 8 to 11 has a first mounting member T1 attached to a vibration generating part and a second mounting member T2 attached to a vibration receiving part, and is configured so that vibration in the first input / output axial direction Q1D is input to the first mounting member T1 as the principal vibration.

[0042] First, generally, when the following two conditions are met: (i) the mass is vibrating in two perpendicular directions, and (ii) the rotational speed is increasing or decreasing due to fluctuations in the inertia of the mass (rotating body), kinetic energy is exchanged in two perpendicular directions. The law of conservation of angular momentum is expressed as follows: In the above equation, I is the inertia (moment of inertia). Therefore, the energy E of a rotating body is expressed as follows: Therefore, E is r 2 Therefore, the closer to the central axis, the greater the energy (the closer to the center, the greater the potential gradient). These facts are important for understanding the operating principle of the vibration isolation device 1.

[0043] The operating principle of the vibration isolation device 1 will now be outlined with reference to Figure 8. In the vibration isolation device 1, for example, when the connecting portion T1c of the first mounting member T1 attached to the vibration generating section receives vibration input in the first input / output axial direction Q1D, the first elastic member B1 and the second elastic member B2 expand and contract, and the mass member F vibrates in the first input / output axial direction Q1D and the second input / output axial direction Q2D. Furthermore, due to a misalignment between the center of gravity FG of the mass member F and the input / output point J (and therefore the connecting portion T1c of the first mounting member T1), the mass member F rotationally vibrates such that the center of gravity FG of the mass member F rotates on an elliptical locus FH when viewed in the mass member axial direction.

[0044] Next, the operating principle of the vibration isolation device 1 will be explained in further detail with reference to Figures 9 to 11. Note that Figures 10 to 11 show differences in the position of the center of gravity FG of the mass member F, but for simplicity's sake do not show deformation or displacement of each part of the vibration isolation device 1. In the following explanation, "upper," "lower," "left," "right," etc. refer to the upper, lower, left, right, etc. when viewed from the respective drawings.

[0045] First, with reference to Figure 9, a supplementary explanation will be given of the elliptical locus FH (Figure 8) along which the center of gravity FG of the mass member F rotates. Regarding the elliptical locus FH shown in Figure 9, for example, the curve of the elliptical locus FH near A is considered to be part of a circle, and the position of its center is estimated. Near A, two tangents are drawn to the elliptical locus FH, and two perpendicular lines are drawn where the tangents meet the elliptical locus FH. The point where the perpendicular lines intersect can be considered to be the rotation center Pa(P) of the center of gravity FG of the mass member F near A. Similarly, the rotation centers Pb(P) and Pc(P) of the center of gravity FG of the mass member F near B and C are drawn, and the extension direction of the rotation radius FR is considered. Therefore, near A: The extension direction of the rotation radius FR is nearly horizontal. Near B: The extension direction of the rotation radius FR is at a 45° angle. Near C: The extension direction of the rotation radius FR is nearly vertical. With this in mind, the operating principle of the vibration isolation device 1 will be explained below.

[0046] First, in FIG. 10( a), the center of gravity FG of the mass member F is located at the leftmost end of the elliptical locus FH. At this time, the first elastic member B1 is fully extended, and the second elastic member B2 is contracted. Because the first elastic member B1 attempts to contract and the second elastic member B2 attempts to extend, the mass member F begins to move diagonally upward to the right. Here, the direction of the radius of rotation FR of the center of gravity FG of the mass member F, which connects the center of rotation P of the center of gravity FG of the mass member F and the center of gravity FG of the mass member F, extends close to the horizontal (first input / output axis direction Q1D). Therefore, when the first elastic member B1 contracts (the mass member F moves horizontally to the right), the potential gradient is an upward gradient, and the mass member F rotates accelerating clockwise around the center of rotation P, resulting in upward motion of the mass member F. This is the direction in which the second elastic member B2 attempts to extend, and energy is transferred from the first elastic member B1 to the second elastic member B2. The amount of transferred energy increases as the amount of energy stored when the first elastic member B1 contracts increases.

[0047] 10(b), the center of gravity FG of the mass member F is closest to the input / output point J (and thus the connecting portion T1c of the first mounting member T1) on the elliptical locus FH. At this time, the extension of the first elastic member B1 and the second elastic member B2 are both close to the neutral point (both extension and contraction are 0). The direction of the radius of rotation FR of the center of gravity FG of the mass member F is diagonal at 45°, and the center of rotation P is at the lower right, so the kinetic energy of the mass member F to the right is converted into kinetic energy in the upward direction. This action works more efficiently the faster the speed of the mass member F around the center of rotation P.

[0048] After that, in Figure 11(a), the center of gravity FG of the mass member F is at the rightmost end of the elliptical locus FH. At this time, the first elastic member B1 is contracted, and the second elastic member B2 is fully extended. Because the first elastic member B1 attempts to extend and the second elastic member B2 attempts to contract, the mass member F begins to move diagonally downward to the left. Here, the extension direction of the radius of rotation FR of the center of gravity FG of the mass member F, which connects the center of rotation P of the center of gravity FG of the mass member F and the center of gravity FG of the mass member F, is nearly horizontal. Therefore, when the first elastic member B1 expands (the mass member F moves horizontally to the left), the potential gradient is an upward gradient, and the mass member F rotates accelerating clockwise around the center of rotation P, resulting in downward motion of the mass member F. This is the direction in which the second elastic member B2 attempts to contract, and energy is transferred from the first elastic member B1 to the second elastic member B2. The amount of transferred energy increases as the energy accumulated when the first elastic member B1 is stretched increases.

[0049] 11(b), the center of gravity FG of the mass member F is located on the elliptical locus FH at the farthest point from the input / output point J (and thus the connecting portion T1c of the first mounting member T1). At this time, the extension of both the first elastic member B1 and the second elastic member B2 is close to the neutral point (both extension and contraction are 0). The direction of the radius of rotation FR of the center of gravity FG of the mass member F is diagonal at 45°, and since the center of rotation P is at the upper left, the kinetic energy of the mass member F to the left is converted into kinetic energy to the downward direction. This action works more efficiently the faster the speed of the mass member F around the center of rotation P.

[0050] The vibration isolation device 1 repeats the operations shown in Figures 10 and 11. To briefly summarize the above, when vibration is input to the vibration isolation device 1 in the first input / output axial direction Q1D, the center of gravity FG of the mass member F rotates on an elliptical locus FH when viewed in the mass member axial direction. As a result, vibration energy is transferred from the first elastic member B1 to the second elastic member B2, and in the second elastic member B2, which has a high damping force, the vibration energy is converted into thermal energy, thereby effectively absorbing the vibration. This concludes the discussion of the operating principle of the vibration isolation device 1.

[0051] The vibration isolation device according to the present invention is not limited to the vibration isolation device 1 of each of the above-described embodiments, but may include various modified examples. Below, we will explain preferred configurations and modified examples of the vibration isolation device 1. Unless otherwise specified, the various configurations described below can be suitably applied to each example described in this specification.

[0052] When viewed in the axial direction of the mass member, the first input / output axial direction Q1D is preferably the direction of the principal vibration input to the vibration damping device 1. In this case, the vibration input in the first input / output axial direction Q1D can be efficiently converted into the second input / output axial direction Q2D and can therefore be efficiently absorbed by the second elastic member B2. This more reliably achieves both resonance suppression and low dynamic magnification.

[0053] 1 and 6, it is preferable that the first input / output axis Q1 and the second input / output axis Q2 are perpendicular to each other when viewed in the mass member axial direction. This allows the vibration damping device 1 to more appropriately exhibit its effectiveness as a vehicle vibration damping device when, for example, the first input / output axis Q1D is the front-to-rear direction of the vehicle and the second input / output axis Q2D is the up-and-down direction of the vehicle. However, when viewed in the mass member axial direction, the first input / output axis Q1 and the second input / output axis Q2 may intersect with each other at any angle other than 90°.

[0054] As shown in each of the examples in Figures 1 to 7, the vibration isolation device 1 may include one mass member F, two first mounting members T1 arranged on both sides of the mass member axial direction, and a second mounting member T2 arranged between the two first mounting members T1 in the mass member axial direction and spaced apart from the two first mounting members T1. This improves vibration balance. In this case, as shown in each of the examples in Figures 1 to 7, it is preferable that, on the inner peripheral side of the mass member F, there be provided connecting portions T1c of the two first mounting members T1 arranged on both sides of the mass member axial direction, and a connecting portion T2c of the second mounting member T2 arranged between the connecting portions T1c of the two first mounting members T1 in the mass member axial direction.

[0055] 2 and 3, the first mounting member T1 (specifically, its connecting portion T1c) may be connected to the mass member F via any one of the first elastic members B11 (B1) and any one of the second elastic members B21 (B2), and the second mounting member T2 (specifically, its connecting portion T2c) may be connected to the mass member F via only one of the first elastic members B12 (B1). More specifically, in the example of FIGS. 2 and 3, the two first mounting members T1 (specifically, their connecting portions T1c) are each connected to the mass member F via any one of the first elastic members B11 (B1) and any one of the second elastic members B21 (B2), and the second mounting member T2 (specifically, its connecting portion T2c) is connected to the mass member F via only one of the first elastic members B12 (B1). Each first mounting member T1 is connected to a separate first elastic member B11 (B1). In this case, since the second mounting member T2 and the mass member F are not connected via the second elastic member B2, transmission of vibration in the second input / output axial direction Q2D is suppressed, thereby making it difficult for vibration in the second input / output axial direction Q2D to be transmitted to the vibration receiving member. In this case, it is preferable that the first mounting member T1 is attached to the vibration generating member and the second mounting member T2 is attached to the vibration receiving member. In this case, for example, when vibration in the first input / output axial direction Q1D is input to the first mounting member T1 attached to the vibration generating member, vibration in the second input / output axial direction Q2D generated by the movement of the mass member F and the elastic body portion B is difficult to transmit to the second mounting member T2 attached to the vibration receiving member.

[0056] Alternatively, as in each example of Figures 4 to 7, the first mounting member T1 (specifically, its connecting portion T1c) may be connected to the mass member F via any one of the first elastic members B11 (B1) and any one of the second elastic members B21 (B2), and the second mounting member T2 (specifically, its connecting portion T2c) may be connected to the mass member F via any one of the first elastic members B12 (B1) and any one of the second elastic members B22 (B2). More specifically, in each of the examples shown in Figures 4 to 7, the two first mounting members T1 (specifically, their connecting portions T1c) are each connected to the mass member F via one of the first elastic members B11 (B1) and one of the second elastic members B21 (B2), and the second mounting members T2 (specifically, their connecting portions T2c) are each connected to the mass member F via one of the first elastic members B12 (B1) and one of the second elastic members B22 (B2). Each first mounting member T1 is connected to a different first elastic member B11 (B1) and a different second elastic member B21 (B2). This allows for a greater resonance suppression effect compared to the example shown in Figures 2 and 3, in which the second mounting members T2 and the mass member F are not connected via the second elastic member B2. In this case, there is almost no difference in the effect obtained between when the first mounting member T1 is attached to the vibration generating part and the second mounting member T2 is attached to the vibration receiving part and when the first mounting member T1 is attached to the vibration receiving part and the second mounting member T2 is attached to the vibration generating part.

[0057] 1 to 7, it is preferable that the elastic body portion B includes a first elastic member B11 (B1) that connects the first mounting member T1 (specifically, its connecting portion T1c) to the mass member F, and a first elastic member B12 (B1) that connects the second mounting member T2 (specifically, its connecting portion T2c) to the mass member F. In this case, it is preferable that the mounting members T1, T2 are each connected to a separate first elastic member B1, as in the examples of FIGS.

[0058] 1 to 7, it is preferable that the elastic body portion B includes a second elastic member B21 (B2) that connects the first attachment member T1 (specifically, the connecting portion T1c) and the mass member F. In this case, when multiple first attachment members T1 are provided as in the examples of Figures 1 to 7, it is preferable that each first attachment member T1 is connected to a separate second elastic member B21 (B2).

[0059] As in the examples of Figures 4 to 7, the elastic body portion B may include a second elastic member B22 (B2) that connects the second mounting member T2 (specifically, the connecting portion T2c) and the mass member F. This can further enhance the resonance suppression effect. When the first mounting member T1 and the second mounting member T2 are each connected to the second elastic member B2 as in the examples of Figures 4 to 7, it is preferable that each mounting member T1, T2 is connected to a separate second elastic member B2.

[0060] 1 to 7, when the first mounting member T1 (specifically, its connecting portion T1c) is connected to the mass member F via one of the first elastic members B11 (B1) and one of the second elastic members B21 (B2), it is preferable that the end B1T of the first elastic member B11 (B1) connected to the first mounting member T1, which is on the first mounting member T1 side, and the end B2T of the second elastic member B21 (B2) connected to the first mounting member T1, which is on the first mounting member T1 side, are located at substantially the same position in the mass member axial direction FOD. This allows for more effective resonance suppression and low dynamic magnification.

[0061] 4 to 7, when the second mounting member T2 (specifically, its connecting portion T2c) is connected to the mass member F via one of the first elastic members B12 (B1) and one of the second elastic members B22 (B2), it is preferable that the end B1T of the first elastic member B12 (B1) connected to the second mounting member T2, which is located on the second mounting member T2 side, and the end B2T of the second elastic member B22 (B2) connected to the second mounting member T2, which is located on the second mounting member T2 side, are located at substantially the same position in the mass member axial direction FOD. This allows for more effective resonance suppression and low dynamic magnification.

[0062] 1 to 7 , when the mass member F is ring-shaped, the attachment portions T1t, T2t of the attachment members T1, T2 may be located outside the mass member F. In this case, as in the examples of FIGS. 1 to 7 , the attachment members T1, T2 may extend in any direction between the connecting portions T1c, T2c and the attachment portions T1t, T2t, respectively. For example, they may extend perpendicular to the mass member axis and pass through a through hole Fh provided in the mass member F, or they may extend in the mass member axial direction FOD and pass through an open end face of the mass member F on either side in the mass member axial direction FOD. In the examples of FIGS. 1 to 5 , the first attachment member T1 extends in the mass member axial direction FOD between the connecting portions T1c, T2c and the attachment portion T1t and passes through an open end face of the mass member F on either side in the mass member axial direction FOD. The attachment portion T1t is located outward in the mass member axial direction FOD from the connecting portion T1c. The first attachment member T1 in the examples shown in FIGS. 6 and 7 extends in the direction perpendicular to the mass member axis (more specifically, in the first input / output axial direction Q1D) between the connecting portion T1c and the attachment portion T1t and passes through a through hole Fh provided in the mass member F. The attachment portion T1t is located on a first side Q1D1 in the first input / output axial direction from the connecting portion T1c. The second attachment member T2 in the examples shown in FIGS. 1 to 7 extends in the direction perpendicular to the mass member axis (more specifically, in the first input / output axial direction Q1D) between the connecting portion T2c and the attachment portion T2t and passes through a through hole Fh provided in the mass member F. The attachment portion T2t is located on a second side Q1D2 in the first input / output axial direction from the connecting portion T2c.

[0063] The vibration-damping devices according to the examples and comparative examples were each evaluated by analysis, as described below. For the analysis, analytical models of the vibration-damping devices according to the examples and comparative examples were created. The model of the vibration-damping device according to the comparative example, although not shown, had a torque rod configuration in which a dynamic damper consisting of an elastic member and a mass member was attached to a rod main body connecting a large bushing and a small bushing. In this torque rod, the tan δ of the elastic member of the large bushing was 0.05, the tan δ of the elastic member of the small bushing was 0.2, the tan δ of the elastic member of the dynamic damper was 1.0, and the ratio M1:M2 of the mass M1 of the rod main body functioning as a mass member to the mass M2 of the dynamic damper's mass member was 100:100. The tan δ of the elastic member of a typical dynamic damper is approximately 0.2 or less. The tan δ of the elastic member of the dynamic damper used in the comparative example was much higher than typical ones, and elastic members with such high tan δ are rarely used in actual products. Furthermore, in a typical torque rod with a dynamic damper, the ratio of the mass M2 of the dynamic damper's mass member to the mass M1 of the rod body is approximately 10%, but in the comparative example, this ratio was significantly increased. Increasing the mass to this extent in an actual product is not realistic in the automotive field, where weight reduction is particularly required. In the comparative example, the tan δ and mass were set as described above to achieve as much resonance suppression and low dynamic magnification as possible in a torque rod with a dynamic damper. The vibration-damping device model according to the example had the configuration shown in Figures 6 and 7. The vibration-damping device 1 of the example had the same material (physical properties) throughout, and the thickness of each portion was adjusted to achieve rigidity or elasticity in each portion. In the vibration-damping device 1, the tan δ of each first elastic member B1 was 0.05, the tan δ of each second elastic member B2 was 1.0, and the mass of the mass member F was the same as the mass M1 of the rod body in the comparative example. In other words, since the vibration-damping device 1 of the embodiment has only one mass member F, the total mass of the mass member is half that of the comparative example (the sum of the mass M1 of the rod body and the mass M2 of the dynamic damper mass member), resulting in a significant weight reduction.In the example, the tan δ of each first elastic member B1 was set to 0.05, so that a low dynamic magnification similar to that of the comparative example could be achieved.

[0064] Vibration characteristics were evaluated by analysis using models of the example and the comparative example. In the vibration-damping device 1 of the example, vibration was input to the first mounting member T1 in the first input / output axial direction Q1D. The results are shown in FIGS. 12 and 13 , respectively. FIG. 12 shows the analysis results for the example, and FIG. 13 shows the analysis results for the comparative example. In FIGS. 12 and 13 , the horizontal axis represents frequency (Hz), and the vertical axis represents spring constant K (N / mm). As can be seen from FIGS. 12 and 13 , both examples achieved substantially the same resonance magnification (the ratio of the spring constant K at the frequency at resonance to the spring constant K near 0 Hz). Furthermore, the resonance magnification was sufficiently reduced, being less than 2.0. Therefore, the example achieved a low dynamic magnification and resonance suppression effect similar to those of the comparative example, while achieving a significantly lighter weight than the comparative example.

[0065] The vibration-damping device of the present invention can be used as various types of vibration-damping devices, but is particularly suitable for use as a vibration-damping device for vehicles, and is particularly suitable for use in devices where the vibration input direction is basically fixed to one direction, such as torque rods and motor mounts for electric vehicles.

[0066] 1: Vibration isolation device, T1: First mounting member (mounting member), T1c: Connecting portion, T1t: Mounting portion, T2: Second mounting member (mounting member), T2c: Connecting portion, T2t: Mounting portion, B: Elastic portion, B1, B11, B12: First elastic member, B1F: End portion on mass member side, B1T: End portion on mounting member side, B2, B21, B22: Second elastic member, B2F: End portion on mass member side, B2T: End portion on mounting member side, F: Mass member, Fh: Through hole, FO: Mass member axis, FOD: Mass member axial direction, FG: Center of gravity of mass member, FH: Ellipse locus, P, Pa, Pb, Pc: Center of rotation of center of gravity of mass member, FR: Radius of rotation of center of gravity of mass member, Q1: First input / output axis, Q1D: First input / output axis direction, Q1D1: First side in the first input / output axis direction, Q1D2: Second side in the first input / output axis direction, Q2: Second input / output axis, Q2D: Second input / output axis direction, Q2D1: First side in the second input / output axis direction, Q2D2: Second side in the second input / output axis direction, J: Input / output point

Claims

1. A vibration-damping device comprising: a first mounting member configured to be attached to one of a vibration generating unit and a vibration receiving unit; a second mounting member configured to be attached to the other of the vibration generating unit and the vibration receiving unit and spaced apart from the first mounting member; an elastic body portion; and a mass member connected to the first mounting member and the second mounting member via the elastic body portion and forming a whole or partial ring shape, wherein the elastic body portion includes: one or more first elastic members having one end connected to the mass member and extending above or near a predetermined first input / output axis when viewed in the axial direction of the mass member; and one or more second elastic members having one end connected to the mass member and extending above or near a predetermined second input / output axis when viewed in the axial direction of the mass member; an end of the first elastic member on the mass member side and an end of the second elastic member on the mass member side are located at different positions from each other in the circumferential direction of the mass member, a vibration-proof device, wherein, when viewed in the axial direction of the mass member, the center of gravity of the mass member is offset in a second input / output axial direction parallel to the second input / output axis with respect to an input / output point which is the intersection of the first input / output axis and the second input / output axis, and the second elastic member is made of an elastic material having a higher damping force than the first elastic member.

2. An anti-vibration device as described in claim 1, wherein a first input / output axial direction parallel to the first input / output axial line when viewed in the axial direction of the mass member is the direction of the main vibration input to the anti-vibration device.

3. An anti-vibration device as described in claim 1, comprising: one mass member; two first mounting members arranged on both sides of the mass member in the axial direction; and a second mounting member arranged between the two first mounting members in the axial direction of the mass member and spaced apart from the two first mounting members.

4. The vibration-damping device described in claim 3, wherein the two first mounting members are each connected to the mass member via one of the first elastic members and one of the second elastic members, and the second mounting member is connected to the mass member only via one of the first elastic members.

5. An anti-vibration device as described in claim 3, wherein the two first mounting members and the second mounting member are each connected to the mass member via one of the first elastic members and one of the second elastic members.

6. The vibration isolation device according to claim 1, wherein, when viewed in the axial direction of the mass member, the first input / output axis and the second input / output axis are perpendicular to each other.

7. An anti-vibration device as described in claim 1, wherein the first mounting member is connected to the mass member via any one of the first elastic members and any one of the second elastic members, and the second mounting member is connected to the mass member only via any one of the first elastic members.

8. The vibration-isolating device as described in claim 1, wherein the first mounting member and the second mounting member are each connected to the mass member via one of the first elastic members and one of the second elastic members.

9. An anti-vibration device as described in claim 7, wherein the end of the first elastic member connected to the first mounting member on the first mounting member side and the end of the second elastic member connected to the first mounting member on the first mounting member side are positioned at substantially the same position in the axial direction of the mass member.

10. An anti-vibration device as described in claim 8, wherein the end of the first elastic member connected to the second mounting member on the second mounting member side and the end of the second elastic member connected to the second mounting member on the second mounting member side are positioned at substantially the same position in the axial direction of the mass member.

11. An anti-vibration device as described in claim 1, wherein when vibration is input to the anti-vibration device in the direction of a first input / output axis parallel to the first input / output axis when viewed in the axial direction of the mass member, the center of gravity of the mass member rotates on an elliptical locus when viewed in the axial direction of the mass member.

Images