Anti-vibration device

Abstract

To provide a vibration control device which achieves improvement of its durability and displacement restriction force while preventing a displacement restriction part from affecting spring characteristics.SOLUTION: A hanger rubber HR is attached to a space between a vehicle body and an exhaust pipe and includes: a first base part 1 provided with a first attachment part 1a to be attached to a vehicle body; a second base part 2 which is provided spaced apart from the first base part in a vertical direction and provided with a second attachment part 2a to be attached to an exhaust pipe; a pair of connection parts 3, 4 which connects the first base part 1 and the second base part 2 with each other; and an annular displacement restriction part 5 which encloses the first attachment part 1a and the second attachment part 2a and restricts a range in which the attachment parts 1a, 2a attached to a support and a supported body can be displaced in a direction such that the attachment parts 1a, 2a separate from each other. In an area where the displacement restriction part 5 is arranged is located at an inner side in a lateral direction relative to the pair of connection parts 3, 4. First spaces SP1 are respectively provided between the displacement restriction part 5 and the pair of connection parts 3, 4.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Patent Document 1 discloses an automobile exhaust pipe vibration-proof support (vibration-proof device) having an H-shaped space in the center of a substantially disk-shaped rubber elastic member, the H-shaped space being made up of a horizontally long space and vertically long spaces provided at both ends of the horizontal space, and mounting holes (mounting parts) on both sides of the horizontally long space. A belt-shaped rubber elastic restraining member having a fiber cord (displacement limiting part) embedded therein is embedded in the entire peripheral edge of the substantially disk-shaped rubber elastic member. Patent Documents 2 to 4 also disclose vibration-proof devices in which displacement limiting parts are embedded in the entire peripheral edge of a rubber elastic member, similar to Patent Document 1.

[0003] Furthermore, Patent Documents 5 to 7 disclose vibration-isolating devices in which a displacement limiting portion is disposed on the outer circumferential side of a rubber elastic member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Jpn. Jpn. Published No. 63-13056 [Patent Document 2] U.S. Patent No. 6,264,164 [Patent Document 3] JP 2010-229888 A [Patent Document 4] U.S. Pat. No. 4,893,778 [Patent Document 5] U.S. Patent No. 7,575,216 [Patent Document 6] JP 2009-108946 A [Patent Document 7] German Patent No. 102008021206 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, anti-vibration devices are attached to a supporting body and a supported body, and are required to absorb vibrations of the supporting body and the supported body while limiting their displacement. For example, in the case of an anti-vibration device that is placed between a vehicle body (supporting body) and an exhaust pipe (supported body) located below the vehicle body and supports the exhaust pipe by suspending it from the vehicle body, as the weight of the exhaust pipe increases, the anti-vibration device is required to have a greater force (hereinafter referred to as "displacement limiting force") to limit the displacement of the exhaust pipe away from the vehicle body.

[0006] However, it has been found that in configurations in which the displacement limiting portion is embedded in the entire periphery of the vibration-isolating device, as in Patent Documents 1 to 4, cracks are likely to occur, particularly in the boundary between the displacement limiting portion and the rubber elastic member, and sufficient durability may not be obtained. Furthermore, it has been found that in such configurations, the displacement limiting portion affects the spring characteristics of the vibration-isolating device, and the vibration-isolating device may not have the desired spring characteristics.

[0007] It was also found that in configurations such as those in Patent Documents 5 to 7, in which the displacement limiting part is arranged on the outer periphery of the peripheral end part of the vibration-damping device, the displacement limiting part does not provide sufficient displacement limiting force to limit the displacement between the support body and the supported body.

[0008] The present invention has been made in consideration of the above points, and has an object to increase the durability and displacement limiting force of a vibration isolation device while not affecting the spring characteristics by using a displacement limiting portion. [Means for solving the problem]

[0009] A first invention is a vibration-damping device attached between a support and a supported object having elasticity or viscoelasticity, the device comprising: a first base having a first mounting portion attached to the support; a second base having a second mounting portion provided vertically spaced apart from the first mounting portion and attached to the supported object; a pair of connecting portions connecting the first base and the second base to each other, the pair of connecting portions including a first connecting portion provided on one side of the lateral positions of the first mounting portion and the second mounting portion, and a second connecting portion provided on the other side of the lateral positions of the first mounting portion and the second mounting portion from the first connecting portion; and an annular displacement limiting portion surrounding the first mounting portion and the second mounting portion and limiting the range in which both mounting portions attached to the support and the supported object can be displaced in a direction away from each other, the region in which the displacement limiting portion is arranged is laterally inward of the pair of connecting portions, and a first space is provided between the displacement limiting portion and the first connecting portion, and between the displacement limiting portion and the second connecting portion,

[0010] According to the first invention, the annular displacement limiting portion surrounds the first mounting portion and the second mounting portion, and therefore the tension applied in the circumferential direction of the displacement limiting portion can limit the range of displacement of the two mounting portions so that they move away from each other. Here, the shorter the overall circumferential length of the displacement limiting portion, and the closer the extension direction (circumferential direction) of the displacement limiting portion is to the direction in which the two mounting portions move away from each other, the easier it is to limit the displacement of the two mounting portions so that they move away from each other due to the tension applied in the circumferential direction of the displacement limiting portion. In the first invention, the region in which the displacement limiting portion is arranged is laterally inward from the pair of connecting portions, and therefore the overall circumferential length of the displacement limiting portion can be made shorter than a configuration in which the displacement limiting portion is arranged laterally outward from the pair of connecting portions or a configuration in which the displacement limiting portion is embedded in the pair of connecting portions. In addition, a first space is provided between the displacement limiting portion and the first connecting portion, and between the displacement limiting portion and the second connecting portion, respectively, and therefore the region in which the displacement limiting portion is arranged is narrowed in the lateral direction, and it is easier to make the extension direction of the displacement limiting portion follow the vertical direction in which the two mounting portions move away from each other. As a result, the tension applied in the circumferential direction of the displacement limiting portion makes it easier to limit the range of displacement of the two mounting portions so as to move away from each other, and the displacement limiting force becomes stronger.

[0011] Furthermore, according to the first aspect of the present invention, since the first space is provided between the displacement limiting part and both connecting parts, the displacement limiting part is less likely to cause cracks in the vibration-damping device, and the displacement regulating part is less likely to affect the spring characteristics of the vibration-damping device. As a result, the displacement limiting part can increase the durability and displacement limiting force of the vibration-damping device while not affecting the spring characteristics.

[0012] In a second aspect of the present invention, in the first aspect of the present invention, a second space is provided on the inner peripheral side of the displacement limiting portion.

[0013] According to this second invention, a second space is provided on the inner side of the displacement limiting portion, making it easier to adjust the spring characteristics of the entire vibration-damping device by changing the size and shape of the second space, further increasing the freedom in setting the spring characteristics of the vibration-damping device.

[0014] A third invention is the anti-vibration device according to the second invention, wherein one side and the other side in the horizontal direction are formed symmetrically to each other, and the pair of connecting parts include a first part that is connected to the first base and extends away from a horizontal center part as it approaches the second base side in the vertical direction, and a second part that is connected to the second base side of the first part and extends closer to the horizontal center part as it approaches the second base side in the vertical direction and is connected to the second base, and the displacement limiting part is a first limiting portion extending from a periphery of the first space toward the second mounting portion and extending away from the horizontal center as it approaches the second mounting portion in the vertical direction, and a second limiting portion connected to the second mounting portion side of the first limiting portion and approaching the horizontal center as it approaches the second mounting portion in the vertical direction, extending to the periphery of the second mounting portion, and a ratio L1 / L2 obtained by dividing the length L1 of the first space along the vertical direction by the length L2 of the second space along the vertical direction is 1.2 or more and 1.5 or less.

[0015] In a fourth aspect of the present invention, in the third aspect of the present invention, the difference L1-L2 obtained by subtracting the length L1 of the first space along the vertical direction from the length L2 of the second space along the vertical direction is 5.6 mm or more and 9.2 mm or less. By setting the lengths L1 and L2 as described above as in the third or fourth aspect of the present invention, the durability of the vibration isolation device can be increased and the entire vibration isolation device can be configured to have desired spring characteristics.

[0016] A fifth invention is the third or fourth invention, wherein the displacement limiting portion is composed of the first limiting portion and the second limiting portion, and a ratio L3 / L0 obtained by dividing a length L3 of each of the pair of connecting portions by a length L0 of a half circumference of the displacement limiting portion is 0.4 to 0.6, inclusive. Note that this length L3 is the length along the extension direction of each of the pair of connecting portions.

[0017] According to this fifth invention, by setting the ratio L3 / L0, obtained by dividing the length L3 of each of a pair of connecting parts by the half circumference length L0 of the displacement limiting part, to be 0.4 or more and 0.6 or less, the durability of the vibration-damping device can be increased and the entire vibration-damping device can be configured to have the desired spring characteristics. Effect of the Invention

[0018] As described above, according to the present invention, the displacement limiting portion can increase the durability and displacement limiting force of the vibration isolation device while not affecting the spring characteristics. [Brief description of the drawings]

[0019] [Figure 1] FIG. 2 is a plan view showing a hanger rubber according to the embodiment. [Diagram 2] FIG. 2 is a view corresponding to FIG. 1 and relating to a first modified example of the embodiment. [Diagram 3] FIG. 10 is a view corresponding to FIG. 1 and relating to a second modified example of the embodiment. [Figure 4] FIG. 11 is a view corresponding to FIG. 1 and relating to a third modified example of the embodiment. [Diagram 5] FIG. 11 is a view corresponding to FIG. 1 and relating to a fourth modified example of the embodiment. [Figure 6]1 is a graph (hysteresis curve) showing the load (vertical axis) when the distance (horizontal axis) between the first mounting portion and the second mounting portion is changed. [Figure 7] 1 is a graph showing the dynamic spring constant (left vertical axis) and loss factor (right vertical axis) versus vibration frequency (horizontal axis) at a load of 30 N. [Figure 8] 1 is a graph showing dynamic spring constant (left vertical axis) and loss factor (right vertical axis) versus vibration frequency (horizontal axis) at a load of 80 N. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following description of preferred embodiments is merely exemplary in nature and is not intended to limit the present invention, its applications, or its uses.

[0021] The hanger rubber HR (vibration isolation device) is attached between the vehicle body (support) and the exhaust pipe (supported object) to support the exhaust pipe relative to the vehicle body and absorb vibrations between the exhaust pipe and the vehicle body. In the following, "upper", "lower", "left" and "right" are used to indicate relative positions on the hanger rubber HR in relation to Fig. 1, with the up-down direction being referred to as the "vertical direction" and the left-right direction being referred to as the "lateral direction". Additionally, "front" refers to the front side in Fig. 1, and "back" refers to the back side in Fig. 1.

[0022] - Composition of hanger rubber - The hanger rubber HR is made of an elastic body and is formed in a substantially circular shape as shown in Fig. 1. The left side (one side in the horizontal direction) and the right side (the other side in the horizontal direction) of the hanger rubber HR are formed symmetrically with respect to the horizontal center, and the upper side and the lower side are formed symmetrically with respect to the vertical center.

[0023] The diameter of the hanger rubber HR is, for example, about 60 to 70 mm, and the thickness in the front-back direction of the hanger rubber HR is, for example, about 25 to 35 mm. The elastic body constituting the hanger rubber HR is formed from a composition containing a rubber component such as natural rubber (NR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), isoprene rubber (IR), butyl rubber (IIR), acrylonitrile-butadiene rubber (NBR), acrylic rubber (ACM, AEM), ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM), vinyl methyl silicone rubber (VMQ), or a rubber component that is a mixture of these.

[0024] The hanger rubber HR comprises a first base 1 provided with a first mounting portion 1a to be attached to the vehicle body, and a second base 2 provided with a second mounting portion 2a to be attached to the exhaust pipe, which is disposed below and spaced apart from the first mounting portion 1a. The first base 1 constitutes the upper portion of the hanger rubber HR, including the upper outer peripheral surface of the hanger rubber HR. The second base 2 constitutes the lower portion of the hanger rubber HR, including the lower outer peripheral surface of the hanger rubber HR.

[0025] The first mounting portion 1a and the second mounting portion 2a are configured with holes h penetrating in the front-to-back direction so that the vehicle body side shaft portion (not shown) and the exhaust pipe side shaft portion (not shown) are inserted therethrough and attached to the vehicle body and the exhaust pipe, respectively. A plurality of gaps s continuous with the hole h are formed in the circumferential direction on the upper inner peripheral surface of the hole h constituting the first mounting portion 1a. Similarly, a plurality of gaps s continuous with the hole h are formed in the circumferential direction on the lower inner peripheral surface of the hole h constituting the second mounting portion 2a. The plurality of gaps s soften the inner peripheral surface of each hole h, making it easy to insert the vehicle body side shaft portion and the exhaust pipe side shaft portion into each hole h.

[0026] The hanger rubber HR includes a rectangular first stopper 1b protruding from the left-right center of the first base 1 toward the second base 2, and a substantially rectangular second stopper 2b protruding from the left-right center of the second base 2 toward the first base 1. In addition, in Fig. 1, the boundaries between the bases 1, 2 and the stoppers 1b, 2b are indicated by dashed lines.

[0027] The left and right side surfaces of the first stopper 1b are aligned along the vertical direction and are curved in a generally arc shape toward the outside in the horizontal direction at the connection portion with the first base 1. The left and right side surfaces of the second stopper 2b are aligned along the vertical direction and are curved in a generally arc shape toward the outside in the horizontal direction at the connection portion with the second base 2.

[0028] When the hanger rubber HR is deformed and the first base 1 and the second base approach each other, the lower end surface of the first stopper 1b and the upper end surface of the second stopper 2b come into contact with each other and function as stoppers, thereby preventing the first mounting portion 1a and the second mounting portion 2a from coming too close to each other. For this reason, the lower end surface of the first stopper 1b and the upper end surface of the second stopper 2b face each other approximately parallel so that they can easily come into contact with each other on their entire surfaces.

[0029] The hanger rubber HR has a pair of connecting parts 3, 4 that connect the first base 1 and the second base 2 to each other. The pair of connecting parts 3, 4 is composed of a first connecting part 3 and a second connecting part 4 that are spaced apart from each other in the horizontal direction. The first connecting part 3 and the second connecting part 4 are both formed integrally with the first base 1 and the second base 2. In FIG. 1, the boundaries between each of the bases 1, 2 and each of the connecting parts 3, 4 are indicated by two-dot chain lines.

[0030] The first connecting portion 3 is provided to the left of the lateral positions of the first mounting portion 1a and the second mounting portion 2a. The second connecting portion 4 is provided to the right of and away from the first connecting portion 3, and is provided to the right of the lateral positions of the first mounting portion 1a and the second mounting portion 2a.

[0031] Each of these pair of connecting parts 3, 4 is composed of a first part 3a, 4a which is the upper half and a second part 3b, 4b which is the lower half. The first part 3a of the first connecting part 3 is connected to the left end of the first base part 1, and extends away from the horizontal center as it approaches the second base part 2 in the vertical direction. The second part 3b of the first connecting part 3 is connected to the lower part of the first part 3a, and extends closer to the horizontal center as it approaches the second base part 2 in the vertical direction and is connected to the left end of the second base part 2. In this way, the first connecting part 3 extends from the left end of the first base part 1 in an arc shape curved along the left outer peripheral surface of the hanger rubber HR, and is connected to the left end of the second base part 2.

[0032] The first part 4a and the second part 4b of the second connecting part 4 have the same configuration as the first part 3a and the second part 3b of the first connecting part 3, but are reversed from left to right. That is, the second connecting part 4 extends from the right end of the first base part 1, curving in an arc shape along the right outer peripheral surface of the hanger rubber HR, and is connected to the right end of the second base part 2.

[0033] The hanger rubber HR has an annular displacement limiting portion 5 surrounding the first attachment portion 1a and the second attachment portion 2a (see the broken line in FIG. 1). The displacement limiting portion 5 limits the range within which the attachment portions 1a, 2a attached to the supporting body and the supported body can be displaced in the direction away from each other. The displacement limiting portion 5 is configured to have a width of about 25 mm in the front-back direction by overlapping multiple threads extending in the circumferential direction, which are made of, for example, aramid fiber, polyester fiber (Tetron (registered trademark), etc.), acrylic fiber, Kevlar (registered trademark) fiber, rayon, etc. Note that the displacement limiting portion 5 may have a width by winding a single thread multiple times.

[0034] The displacement limiting part 5 is disposed so that the first connecting part 3 and the second connecting part 4 are located on the outer periphery side. The area where the displacement limiting part 5 is disposed is laterally inward of the pair of connecting parts 3, 4, i.e., to the right of the first connecting part 3 and to the left of the second connecting part 4.

[0035] 1, the displacement limiting portion 5 is formed in a generally diamond shape with its vertical length longer than its horizontal length and with its vertices facing each other at a portion located above the first mounting portion 1a and a portion located below the second mounting portion 2a. The displacement limiting portion 5 is made up of a first limiting portion 5a constituting the upper half and a second limiting portion 5b constituting the lower half.

[0036] The first limiting portion 5a has its upper portion embedded in the first base portion 1 and is disposed so that its circumferential direction follows the periphery of approximately the upper half of the first mounting portion 1a. The first limiting portion 5a extends from the upper side of the left-right central portion of the first mounting portion 1a in the lower left and right directions, respectively. The first limiting portion 5a extends from the periphery of the first mounting portion 1a toward the second mounting portion 2a, and extends away from the horizontal central portion as it approaches the second mounting portion 2a in the vertical direction.

[0037] The second limiting portion 5b is connected to the second mounting portion 2a side of the first limiting portion 5a, approaches the horizontal center as it approaches the second mounting portion 2a in the vertical direction, and extends to the periphery of the second mounting portion 2a. The second limiting portion 5b has its lower portion embedded in the second base portion 2, and is disposed so that its circumferential direction follows the periphery of approximately the lower half of the second mounting portion 2a.

[0038] As shown in FIG. 1, the displacement limiting portion 5 is embedded in the thin wall portion t that is continuous with the first base portion 1 and the second base portion 2. The thin wall portion t is formed along the displacement limiting portion 5. At the connection portion with the first base portion 1, the inner peripheral side surface (the side surface surrounding the second space SP2 described later) of the thin wall portion t is continuous with the side surfaces of the first base portion 1 and the first stopper 1b in a substantially arc shape. At the connection portion with the second base portion 2, the inner peripheral side surface of the thin wall portion t is continuous with the side surfaces of the second base portion 2 and the second stopper 2b in a substantially arc shape. Note that the displacement limiting portion 5 may be exposed and not embedded in the thin wall portion t, and the hanger rubber HR may not be provided with the thin wall portion t.

[0039] A first space SP1 is provided between the left side portion of the displacement limiting portion 5 and the first connecting portion 3. A first space SP1 is also provided between the right side portion of the displacement limiting portion 5 and the second connecting portion 4. The left first space SP1 is surrounded by the right side surface of the first connecting portion 3 and the left side surface of the thin-walled portion t in which the left side portion of the displacement limiting portion 5 is embedded. The right first space SP1 is surrounded by the left side surface of the second connecting portion 4 and the right side surface of the thin-walled portion t in which the right side portion of the displacement limiting portion 5 is embedded. Both the left and right first spaces SP1, SP1 extend in an approximately arc shape along the first connecting portion 3 and the second connecting portion 4, respectively.

[0040] A second space SP2 is provided on the inner periphery side of the displacement limiting portion 5. The second space SP2 is surrounded by the inner periphery side surfaces of the left and right thin-walled portions t, t, the inner periphery surfaces of the first base portion 1 and the second base portion, the left and right side surfaces of the first stopper 1b and the second stopper 2b, and the end surfaces where the stoppers 1b, 2b face each other. That is, the shape of the second space SP2 is determined by the shapes of the side surfaces and end surfaces of the base portions 1, 2, the stoppers 1b, 2b, and the thin-walled portion t.

[0041] --Setting parameters L0 to L3-- If the length of half the circumference of the displacement limiting portion 5 is L0, the length along the vertical direction of the first space SP1 is L1, the length along the vertical direction of the second space SP2 is L2, and the length along the circumferential direction of each of the pair of connecting portions 3, 4 is L3, then from the viewpoint of increasing the durability of the hanger rubber HR and giving the hanger rubber HR the desired spring characteristics, it is preferable to set these parameters L0 to L3 as follows:

[0042] The hanger rubber HR may be susceptible to cracks occurring in the area between the mounting parts 1a, 2a (holes h) and the second space SP2 due to deformation of the area caused by vibrations that cause the mounting parts 1a, 2a to move away from each other. This can be suppressed, for example, by making the length L1 larger relative to the length L2, or by making the length L3 larger relative to the length L0. From this viewpoint, it is preferable to satisfy at least one of the conditions that the difference L1-L2 is 5.6 mm or more, that the ratio L1 / L2 is 1.2 or more, and that the ratio L3 / L0 is 0.4 or more, and it is more preferable to satisfy all three of these conditions. From the same viewpoint, it is even more preferable to make the ratio L3 / L0 0.5 or more.

[0043] It is also desirable that the hanger rubber HR not become too soft when the mounting portions 1a, 2a are displaced apart from each other, and this can be achieved, for example, by not making the length L1 too large relative to the length L2, or by not making the length L3 too large relative to the length L0. From this point of view, it is preferable to satisfy at least one of the conditions that the difference L1-L2 is 9.2 mm or less, that the ratio L1 / L2 is 1.5 or less, and that the ratio L3 / L0 is 0.6 or less, and it is more preferable to satisfy all three of these conditions.

[0044] --Action and Effects-- According to this embodiment, the annular displacement limiting portion 5 surrounds the first mounting portion 1a and the second mounting portion 2a, and therefore the tension applied in the circumferential direction of the displacement limiting portion 5 can effectively limit the range of displacement of the mounting portions 1a, 2a so that they move away from each other. Here, the shorter the overall circumferential length of the displacement limiting portion 5 is, and the closer the extension direction (circumferential direction) of the displacement limiting portion 5 is to the direction in which the mounting portions 1a, 2a move away from each other, the easier it is to limit the displacement of the mounting portions 1a, 2a so that they move away from each other, due to the tension applied in the circumferential direction of the displacement limiting portion 5. In this embodiment, the region in which the displacement limiting portion 5 is disposed is laterally inward of the pair of connecting portions 3, 4, and therefore it is easier to shorten the overall circumferential length of the displacement limiting portion 5 compared to a configuration in which the displacement limiting portion 5 is disposed laterally outward of the pair of connecting portions 3, 4 or a configuration in which the displacement limiting portion 5 is embedded in the pair of connecting portions 3, 4. In addition, a first space SP1 is provided between the displacement limiting part 5 and the first connecting part 3, and between the displacement limiting part 5 and the second connecting part 4, so that the area in which the displacement limiting part 5 is arranged is narrowed in the horizontal direction, and the circumferential direction of the displacement limiting part 5 is easily aligned with the vertical direction in which the mounting parts 1a, 2a move away from each other. As a result, the tension applied in the circumferential direction of the displacement limiting part 5 makes it easier to limit the range in which the mounting parts 1a, 2a move away from each other, and the displacement limiting force is increased.

[0045] Furthermore, according to this embodiment, the first space SP1 is provided between the displacement limiting part 5 and both connecting parts 3, 4, so that the displacement limiting part 5 is less likely to cause cracks in the hanger rubber HR, and the displacement regulating part 5 is less likely to affect the spring characteristics of the hanger rubber HR. As described above, the displacement limiting part 5 can increase the durability and displacement limiting force of the hanger rubber HR without affecting the spring characteristics.

[0046] According to this embodiment, the pair of connecting parts 3, 4 include the first parts 3a, 4a that extend away from the horizontal center as they move vertically from the first base 1 toward the second base 2, and the second parts 3b, 4b that extend toward the horizontal center as they move vertically from the first parts 3a, 4a toward the second base 2, so that they can deform to expand or contract in the horizontal direction and absorb vibrations of the support and the supported object. The displacement limiting part 5 includes the first limiting part 5a that extends away from the horizontal center as it moves from the periphery of the first mounting part 1a toward the second mounting part 2a, and the second limiting part 5b that follows the first limiting part 5a and approaches the horizontal center as it moves toward the second mounting part 2a, so that they can deform to expand or contract in the horizontal direction with the deformation of the pair of connecting parts 3, 4. While the mounting parts 1a, 2a are vibrating with a relatively small amplitude where the distance between them is smaller than the predetermined distance, the displacement limiting part 5 is deformable in such a way that the tension applied in the circumferential direction of the displacement limiting part 5 is small, so that the displacement of the mounting parts 1a, 2a away from each other is not restricted, and the effect of the pair of connecting parts 3, 4 absorbing vibration is not affected. On the other hand, when the mounting parts 1a, 2a become larger than the predetermined distance, the extension direction (circumferential direction) of the first limiting part 5a and the second limiting part 5b becomes closer to the vertical direction (the inclination angle from the vertical direction becomes smaller), and the tension applied in the circumferential direction of the displacement limiting part 5 becomes larger, restricting the displacement of the mounting parts 1a, 2a away from each other. Therefore, the displacement limiting part 5 is more likely to restrict the displacement of the mounting parts 1a, 2a away from each other so as not to impede the vibration absorbing effect of the hanger rubber HR.

[0047] Furthermore, according to this embodiment, the displacement limiting portion 5 is provided with the first space SP1 disposed from the first connecting portion 3 and the second connecting portion 4, respectively, so that the displacement limiting portion 5 can easily function independently of the first connecting portion 3 and the second connecting portion 4. In other words, it is easy to configure the first connecting portion 3 and the second connecting portion 4 to have desired spring characteristics. Also, it is easy to adjust the spring characteristics of the entire hanger rubber HR by changing the size and shape of the first space SP1, so that the degree of freedom in setting the spring characteristics of the hanger rubber HR is increased.

[0048] In addition, according to this embodiment, a second space SP2 is provided on the inner peripheral side of the displacement limiting portion 5, so that the spring characteristics of the entire hanger rubber HR can be easily adjusted by changing the size and shape of the second space SP2, further increasing the degree of freedom in setting the spring characteristics of the hanger rubber HR.

[0049] Furthermore, according to this embodiment, by setting each of the parameters L0 to L3, the durability of the hanger rubber HR can be increased and the entire hanger rubber HR can be configured to have desired spring characteristics.

[0050] (Modification of the embodiment) The hanger rubber HR according to the modified embodiment will be described below. Note that the description of the configuration common to the above embodiment will be omitted.

[0051] A hanger rubber HR according to a first modified embodiment is shown in Fig. 2. The hanger rubber HR according to this modified embodiment is formed longer vertically than that of the above-mentioned embodiment. The upper end of the first base portion 1 and the lower end of the second base portion 2 are flat surfaces parallel to the horizontal direction.

[0052] A hanger rubber HR according to a second modified embodiment is shown in Fig. 3. The hanger rubber HR according to this modified embodiment is formed in a vertically elongated, approximately elliptical shape. The pair of connecting parts 3, 4 extend approximately linearly in the vertical direction. The displacement limiting part 5 extends approximately linearly in the vertical direction on the lateral inner side of the pair of connecting parts 3, 4. The hanger rubber HR is not provided with stoppers 1b, 2b, and no gap part s is formed on the inner peripheral surface of the hole h of each mounting part 1a, 2a.

[0053] A hanger rubber HR according to a third modified embodiment is shown in FIG. 4. The upper outer peripheral surface of the first base 1 and the lower outer peripheral surface of the second base 2 are both formed in a substantially arc shape. The tangential direction of the outer peripheral surface of the first connecting portion 3 does not coincide with the tangential direction of the outer peripheral surface of the first base 1 at the connection portion with the first base 1, and a gentle recess 6a is formed on the outer peripheral surface of the connection portion between the first connecting portion 3 and the first base. Similar recesses 6b, 6c, and 6d are formed on each outer peripheral surface of the connection portion between the first connecting portion 3 and the second base 2, the connection portion between the second connecting portion 4 and the first base 1, and the connection portion between the second connecting portion 4 and the second base 2. The first stopper 1b is formed so as to be wider on the lateral outward side as it goes downward. The second stopper 2b is formed so as to be wider on the lateral outward side as it goes upward.

[0054] A hanger rubber HR according to a fourth modified embodiment is shown in Fig. 5. The hanger rubber HR according to this modified embodiment is formed to be vertically long. The upper outer peripheral surface of the first base portion 1 and the lower outer peripheral surface of the second base portion 2 are both formed to be approximately arc-shaped. The displacement limiting portion 5 has a bulging portion at the vertical center that curves so as to bulge outward in the horizontal direction.

[0055] (Other embodiments) The hanger rubber HR does not have to be symmetrical from left to right or from top to bottom.

[0056] The elastic body constituting the hanger rubber HR is not limited to being made of rubber, and the hanger rubber HR may be made of a viscoelastic body.

[0057] The hanger rubber HR does not necessarily have to be provided with the second space SP2, and the first base portion 1 and the second base portion 2 may be continuous with each other without any gap therebetween.

[0058] Furthermore, the vibration-isolating device according to the present invention is not limited to the hanger rubber HR attached to the vehicle body and the exhaust pipe. The vibration-isolating device may be attached to a supporting body and a supported body, at least one of which vibrates, and may absorb the vibrations and limit the displacement. For example, the device may be used to hang advertising boards in trains, stations, and other places where vibrations occur frequently, and may also be used for suspension vibration isolation in houses. EXAMPLES

[0059] A hanger rubber having a generally circular shape as shown in FIG. 1 was manufactured, and a static spring characteristic evaluation test, a dynamic spring characteristic evaluation test, and a durability evaluation test were performed.

[0060] [Example 1] In Example 1, a substantially circular hanger rubber with a length of 71 mm, a width of 61 mm, and a thickness of 28 mm was manufactured using a composition containing vinyl methyl silicone rubber (VMQ) as a rubber component. The displacement limiting portion was wound with aramid thread to a width of 25 mm, and was embedded in the first base portion and the second base portion as shown in FIG. 1. The half circumference length L0 of the displacement limiting portion was 70.2 mm, the length L1 along the vertical direction of the first space was 27.9 mm, the length L2 along the vertical direction of the second space was 22.3 mm, and the length L3 of each connecting portion was 31.8 mm. The other configurations were as shown in FIG. 1.

[0061] [Comparative Example 1] In Comparative Example 1, a hanger rubber was produced in the same manner as in Example 1, except that no displacement limiting portion was provided.

[0062] -Static spring characteristic evaluation test- A load was applied to the manufactured hanger rubbers of Example 1 and Comparative Example 1 so as to displace the first and second mounting parts in directions moving away from each other and toward each other at a constant speed. Figure 6 shows the load (vertical axis) and displacement (horizontal axis) changed as described above. Note that the origin of the graph in Figure 6 is the natural state where no load is applied to the hanger rubber, a positive displacement corresponds to a displacement in which the two mounting parts move away from each other, and a negative displacement corresponds to a displacement in which the two mounting parts move toward each other.

[0063] As can be seen from Fig. 6, in the hanger rubber of Example 1, the load was almost proportional to the displacement until the displacement reached a certain value in the positive direction, but when the displacement exceeded the certain value, the load suddenly increased. This shows that the displacement limiting portion limits the displacement of the first and second mounting portions from each other, and that the displacement limiting portion is functioning effectively.

[0064] In contrast to this, the hanger rubber of Comparative Example 1 was not provided with a displacement limiting portion, unlike Example 1, so that even if the displacement exceeded the predetermined value, the load increased almost in proportion to the displacement.

[0065] In addition, it can be seen that when the displacement is equal to or less than the predetermined value, the load on the hanger rubber of Example 1 is about the same as that of Comparative Example 1. From this, it can be said that the displacement regulating portion does not significantly affect the static spring characteristics.

[0066] In both Example 1 and Comparative Example 1, when the displacement reaches a predetermined value in the negative direction, the load in the negative direction (the load required to move both mounting parts closer to each other) increases suddenly. This is because the lower end surface of the first stopper and the upper end surface of the second stopper come into contact with each other and function as stoppers.

[0067] --Dynamic spring characteristic evaluation test-- A load of 30N was applied to displace the first and second mounting parts in the direction away from each other, and from this state, the hanger rubber was vibrated so as to repeat displacement in the direction in which the first and second mounting parts move away from each other and in the direction in which they move toward each other with an excitation amplitude of ±0.2mm and a frequency of 0 to 150Hz, and the static-dynamic ratio (storage spring constant / tangential spring constant under a load of 30N) and loss factor (tanδ) were measured. The measurement results are shown in Figure 7. In addition, a load of 80N was applied to displace the first and second mounting parts in the direction in which they move away from each other, and the measurement results obtained by vibrating them under the same conditions are shown in Figure 8.

[0068] 7 and 8, even when the frequency changes in the range of 0 to 150 Hz, the static-dynamic ratio of the hanger rubber of Example 1 shows a transition almost equivalent to that of Comparative Example 1. This shows that the influence of the presence of the displacement limiting part on the dynamic characteristics is effectively suppressed.

[0069] [Examples 2 to 5] In Examples 2 to 5, hanger rubbers were produced in the same manner as in Example 1, except that the parameters L0 to L3 were changed as shown in Table 1.

[0070] [Table 1]

[0071] -Durability evaluation test- The hanger rubbers of Examples 2 to 5 were vibrated under the same conditions until cracks appeared in the rubber part of the hanger rubber. They were rated A, B, C, and D in order of the number of vibrations required until cracks appeared. That is, A has the highest durability and D has the lowest durability. As can be seen from Table 1, Example 2 (L1 / L2=1.40, L1-L2=8.9 mm, L3 / L0=0.513) has particularly high durability.

[0072] From the above, it can be seen that by appropriately setting each of the parameters L0 to L3, it is possible to increase the durability and displacement limiting force of the vibration isolation device while preventing the displacement limiting portion from affecting the spring characteristics. [Industrial Applicability]

[0073] The present invention is useful for vibration isolation devices. [Explanation of symbols]

[0074] 1 1st base 1a First mounting part 2 Second base 2a Second mounting part 3 1st connection part 3a First part of the first connecting part 3b Second part of the first connection 4 2nd connection part 4a 1st part of the 2nd connecting part 4b Second part of the second connecting part 5 Displacement limiting section 5a First Restriction 5b Second Restriction SP1 1st space SP2 2nd space

Claims

1. A vibration isolation device having elasticity or viscoelasticity and attached between a support and a supported object, A first base portion provided with a first mounting portion that is attached to the support; A second base portion having a second mounting portion provided vertically apart from the first mounting portion and attached to the supported object; A pair of connecting portions connecting the first base portion and the second base portion to each other, a first connecting portion provided on one side in the lateral direction relative to the lateral positions of the first mounting portion and the second mounting portion; a second connecting portion provided apart from the first connecting portion on the other side in the lateral direction and provided on the other side in the lateral direction of the first mounting portion and the second mounting portion; A pair of connecting parts including: a ring-shaped displacement limiting portion that surrounds the first mounting portion and the second mounting portion and limits a range in which both mounting portions attached to the supporting body and the supported body can be displaced in directions away from each other; Equipped with a region in which the displacement limiting portion is disposed is laterally inward of the pair of connecting portions, A first space is provided between the displacement limiting portion and the first connecting portion, and between the displacement limiting portion and the second connecting portion. Anti-vibration device.

2. 2. The vibration isolation device according to claim 1, A vibration-isolating device, wherein a second space is provided on the inner peripheral side of the displacement limiting portion.

3. 3. The vibration isolation device according to claim 2, The vibration isolation device is formed so that one side and the other side in the lateral direction are symmetrical to each other, The pair of connecting portions are a first portion connected to the first base portion and extending away from a lateral center portion as it extends toward the second base portion in a vertical direction; a second portion connected to the second base portion side of the first portion, extending toward the second base portion side in the vertical direction and approaching a center portion in the horizontal direction, and connected to the second base; Including, The displacement limiting portion is a first limiting portion extending from a periphery of the first mounting portion toward the second mounting portion and extending away from a horizontal center portion as it approaches the second mounting portion in a vertical direction; a second limiting portion connected to the second mounting portion side of the first limiting portion, approaching a horizontal center portion as it approaches the second mounting portion in a vertical direction, and extending to a periphery of the second mounting portion; Including, A vibration-isolating device, wherein a ratio L1 / L2 obtained by dividing a length L1 of the first space along the vertical direction by a length L2 of the second space along the vertical direction is 1.2 or more and 1.5 or less.

4. 4. The vibration isolation device according to claim 3, A vibration-isolating device, wherein a difference L1-L2 obtained by subtracting a length L1 of the first space along the vertical direction from a length L2 of the second space along the vertical direction is 5.6 mm or more and 9.2 mm or less.

5. 5. The vibration isolation device according to claim 3, The displacement limiting portion is composed of the first limiting portion and the second limiting portion, A vibration-isolating device, wherein a ratio L3 / L0 obtained by dividing a length L3 of each of the pair of connecting portions by a length L0 of half a circumference of the displacement limiting portion is 0.4 or more and 0.6 or less.

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