Vibration isolation device and vibration isolation mechanism

Abstract

This achieves both maintaining vibration isolation performance and reducing the manufacturing cost of vibration isolation devices. [Solution] The vibration isolation device 30 installed between the first member and the second member comprises a first support 40 fixed to the first member, a second support 50 fixed to the second member, and an elastic body 60 connecting the first support 40 and the second support 50. The first support 40 includes a circular first base portion 41 including a first fixed surface, and a first shaft portion 42 that protrudes from the first fixed surface along the central axis and is inserted into a mounting hole of the first member. The elastic body 60 includes a first side wall portion 61 covering the outer circumferential surface of the first base portion 41, and a vibration isolation portion 65 located between the first support 40 and the second support 50. The outer wall surface of the first side wall portion 61 includes a flat portion which is a plane that contacts a first projection for suppressing the rotation of the first support 40 about the central axis.

Description

Technical Field

[0001] The present disclosure relates to a technique for vibration prevention.

Background Art

[0002] Conventionally, vibration isolation devices for suppressing the propagation of vibration between a first member and a second member have been proposed. For example, Patent Document 1 discloses a configuration in which a plurality of anti-rotation portions are formed on the surface of a metal fastening seat portion on the side opposite to the elastic member in a vibration isolation device in which an elastic member is fixed to the metal fastening seat portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Regarding a metal fastening seat portion having a large number of protrusions as in Patent Document 1, there is a problem that the manufacturing cost is high. In view of the above circumstances, one aspect of the present disclosure aims to achieve both maintaining vibration isolation performance and reducing the manufacturing cost of the vibration isolation device.

Means for Solving the Problems

[0005] To solve the above problems, a vibration isolation device according to one aspect of the present disclosure is a vibration isolation device installed between a first member and a second member, comprising a first support fixed to the first member, a second support fixed to the second member, and an elastic body connecting the first support and the second support, wherein the first support includes a circular first base portion including a first fixed surface, and a first shaft portion protruding from the first fixed surface along a central axis and inserted into a mounting hole of the first member, the elastic body includes a first side wall portion covering the outer circumferential surface of the first base portion, and a vibration isolation portion located between the first support and the second support, the outer wall surface of the first side wall portion includes a planar portion which is a plane that contacts a first rotation suppression portion for suppressing the rotation of the first support about the central axis.

[0006] A vibration isolation mechanism according to one aspect of the present disclosure comprises a first member and a second member, and a vibration isolation device installed between the first member and the second member, wherein the vibration isolation device comprises a first support fixed to the first member, a second support fixed to the second member, and an elastic body connecting the first support and the second support, wherein the first support includes a circular first base portion including a first fixed surface, and a first shaft portion protruding from the first fixed surface along a central axis and inserted into a mounting hole of the first member, wherein the elastic body includes a first side wall portion covering the outer circumferential surface of the first base portion, and a vibration isolation portion located between the first support and the second support, wherein the outer wall surface of the first side wall portion includes a planar portion which is a plane that contacts a first rotation suppression portion for suppressing the rotation of the first support about the central axis. [Brief explanation of the drawing]

[0007] [Figure 1] This is a side view of the vibration isolation mechanism in the first embodiment. [Figure 2] This is a perspective view of the vibration isolation device. [Figure 3] This is a side view of the vibration isolation device. [Figure 4] This is a cross-sectional view of the vibration isolation device (cross-section of line IV-IV in Figure 6). [Figure 5] This is a cross-sectional view of the vibration isolation device (cross-section of the VV line in Figure 6). [Figure 6] This is a plan view of the vibration isolation device. [Figure 7] This is a plan view of the vibration isolation device. [Figure 8] This is a side view showing the vibration isolation device installed. [Figure 9] This is a perspective view of the vibration isolation device in the second embodiment. [Modes for carrying out the invention]

[0008] The embodiments for implementing this disclosure will be described with reference to the drawings. Note that the dimensions and scale of the elements in each drawing may differ from those of the actual product. Furthermore, the embodiments described below are illustrative examples of embodiments that may be envisioned when implementing this disclosure. Therefore, the scope of this disclosure is not limited to the embodiments exemplified below.

[0009] A: First Embodiment Figure 1 is a side view of the vibration isolation mechanism 100 in the first embodiment. As illustrated in Figure 1, the vibration isolation mechanism 100 of the first embodiment comprises a first structure 10, a second structure 20, and a plurality of vibration isolation devices 30. Each of the plurality of vibration isolation devices 30 is a device that suppresses (i.e., isolates) the propagation of vibrations between the first structure 10 and the second structure 20. The configuration of each of the plurality of vibration isolation devices 30 is common.

[0010] The first structure 10 is a structure that generates vibrations. Specifically, it is various mechanical devices mounted on mobile bodies such as electric vehicles. For example, the housing of an electric motor or auxiliary equipment (e.g., a cooling compressor or pump) is exemplified as the first structure 10. The first structure 10 includes a plurality of first members 11 installed at different positions. Each first member 11 is a bracket for installing the vibration isolation device 30. Each first member 11 has a first mounting hole 12 for installing the vibration isolation device 30. The first mounting hole 12 is a circular through hole.

[0011] The second structure 20 is a foundation that supports the first structure 10. For example, a vehicle frame mounted on a mobile body such as an electric vehicle is exemplified as the second structure 20. The second structure 20 includes a plurality of second members 21 installed at different positions. Each second member 21 is a bracket for installing the vibration isolation device 30. Each second member 21 has a second mounting hole 22 for installing the vibration isolation device 30. The second mounting hole 22 is a circular through hole.

[0012] The first member 11 and the second member 21 face each other. A vibration isolation device 30 is installed for each pair of the first member 11 and the second member 21. Specifically, a vibration isolation device 30 is installed between the first member 11 and the second member 21. The vibration isolation device 30 suppresses the propagation of vibrations between the first member 11 and the second member 21. In the above description, the case in which the first structure 10 is the vibration source is illustrated, but configurations in which the second structure 20 is the vibration source, or configurations in which both the first structure 10 and the second structure 20 are vibration sources, are also conceivable. Each vibration isolation device 30 is also used as an element to support the first structure 10. Multiple vibration isolation devices 30 may be installed between the first member 11 and the second member 21.

[0013] Figure 2 is a perspective view of the vibration isolation device 30, and Figure 3 is a side view of the vibration isolation device 30. The central axis C of the vibration isolation device 30 is shown in Figures 2 and 3. In the following explanation, the direction of the central axis C will be referred to as the "axial direction." The axial direction is distinguished into the Z1 direction and the Z2 direction. The Z1 direction is one direction along the central axis C, and the Z2 direction is the opposite direction to the Z1 direction. In addition, the direction of the circumference of a virtual circle of arbitrary diameter centered on the central axis C will be referred to as the "circumferential direction," and the direction of the radius of the virtual circle will be referred to as the "radial direction." In the radial direction, the direction opposite to the central axis C will be referred to as the "outside," and in the radial direction, the direction toward the central axis C will be referred to as the "inside."

[0014] As illustrated in Figures 2 and 3, the vibration isolation device 30 comprises a first support 40, a second support 50, and an elastic body 60. The first support 40 and the second support 50 are installed spaced apart from each other in the axial direction. The first support 40 is fixed to the first member 11. The second support 50 is fixed to the second member 21. The elastic body 60 connects the first support 40 and the second support 50. The first support 40 and the second support 50 can also be described as structures that support the elastic body 60.

[0015] The first support 40 and the second support 50 are structures with higher rigidity than the elastic body 60, and are formed from, for example, a metallic material. Various manufacturing techniques, such as forging or casting, can be used to manufacture the first support 40 and the second support 50. Examples of metallic materials used for the first support 40 and the second support 50 include stainless steel, SPCC (Steel Plate Cold Commercial), or SPHC (Steel Plate Hot Commercial). The first support 40 and the second support 50 may also be formed from, for example, a highly rigid resin material. Furthermore, the first support 40 and the second support 50 may be formed from the same material or from different materials.

[0016] The elastic body 60 is a vibration-absorbing member that absorbs vibrations generated in the first structure 10. The elastic body 60 is formed from an elastic material such as rubber. Examples of rubber materials that can be used for the elastic body 60 include chloroprene rubber (CR), silicone rubber (SR), acrylic rubber (ACM), urethane rubber (U), polyurethane rubber (PUR), vinyl methyl silicone rubber (VMQ), ethylene propylene diene rubber (EPDM), or fluororubber (FKM). The elastic body 60 may also be formed from a low-rigidity resin material, for example.

[0017] The first support 40, the second support 50, and the elastic body 60 are integrally formed by injection molding (i.e., insert molding) using a molding die such as a metal die or a resin die. Specifically, the vibration isolator 30 is manufactured by injecting a molten resin that becomes the material of the elastic body 60 into a molding die in which the first support 40 and the second support 50 are installed, and then demolding after the molten resin hardens. That is, the vibration isolator 30 is a molded product in which the first support 40, the second support 50, and the elastic body 60 are integrally formed.

[0018] In the above configuration, the vibration propagated from the first structure 10 to the first support 40 is absorbed by the elastic deformation of the elastic body 60. Similarly, the vibration propagated from the second structure 20 to the second support 50 is absorbed by the elastic deformation of the elastic body 60. That is, the vibration isolator 30 suppresses the propagation of vibration between the first structure 10 and the second structure 20.

[0019] FIG. 4 and FIG. 5 are cross-sectional views of the vibration isolator 30. A cross-section including the central axis C is shown in FIGS. 4 and 5. FIG. 6 is a plan view of the vibration isolator 30 as viewed from a viewpoint located in the Z1 direction with respect to the vibration isolator 30. The cross-sectional view taken along line IV-IV in FIG. 6 corresponds to FIG. 4, and the cross-sectional view taken along line V-V in FIG. 6 corresponds to FIG. 5.

[0020] As illustrated in FIGS. 4 to 6, the first support 40 is a structure including a first base portion 41 and a first shaft portion 42. The first base portion 41 and the first shaft portion 42 are integrally formed. However, the first shaft portion 42 may be formed separately from the first base portion 41 and fixed to the first base portion 41.

[0021] The first base portion 41 is a portion formed in a circular shape with an outer diameter D as viewed from the axial direction. The first base portion 41 is installed coaxially with the central axis C. Specifically, the first base portion 41 is a circular plate-like portion including a first fixing surface 411 and a first opposing surface 412 located on opposite sides of each other. The first fixing surface 411 is a circular flat surface facing in the Z1 direction, and the first opposing surface 412 is a circular flat surface facing in the Z2 direction. The first fixing surface 411 and the first opposing surface 412 are orthogonal to the axial direction. The plate thickness of the first base portion 41 is constant throughout the entire area of the first base portion 41.

[0022] The first shaft portion 42 is a cylindrical part that protrudes from the first fixed surface 411 in the Z1 direction along the central axis C. The first shaft portion 42 is installed coaxially with the first base portion 41. The outer diameter of the first shaft portion 42 is less than the outer diameter D of the first base portion 41. Therefore, as illustrated in Figure 6, when viewed from the axial direction, the outer circumferential surface of the first shaft portion 42 is located inside the outer circumferential surface of the first base portion 41. As illustrated in Figures 2 and 3, a helical screw groove is formed on the outer circumferential surface of the first shaft portion 42, centered on the central axis C.

[0023] As described above, the first support 40 is a rotating body about a central axis C. Therefore, compared to a configuration where the planar shape of the first base 41 is, for example, a polygon (i.e., a configuration where the first support 40 is a non-rotating body), it is easier to reduce the manufacturing cost of the first support 40. For example, the first support 40 can be manufactured by inexpensive rotary machining using a machining device such as a lathe.

[0024] Figure 7 is a plan view of the vibration isolation device 30 as seen from a viewpoint located in the Z2 direction relative to the vibration isolation device 30. As illustrated in Figures 4 to 7, the shape of the second support 50 and the shape of the first support 40 are the same. Specifically, as illustrated in Figures 4 and 5, the second support 50 is a structure that includes a second base 51 and a second shaft 52. The second base 51 and the second shaft 52 are formed integrally. However, the second shaft 52 may be formed separately from the second base 51 and fixed to the second base 51.

[0025] The second base portion 51 is a circular portion with an outer diameter D when viewed from the axial direction. The second base portion 51 is installed coaxially with the central axis C. Specifically, the second base portion 51 is a circular plate-like portion that includes a second fixed surface 511 and a second opposing surface 512 located on opposite sides of each other. The second fixed surface 511 is a circular flat surface facing in the Z2 direction, and the second opposing surface 512 is a circular flat surface facing in the Z1 direction. The second fixed surface 511 and the second opposing surface 512 are perpendicular to the axial direction. The plate thickness of the second base portion 51 is constant throughout the entire area of ​​the second base portion 51. As illustrated in Figures 4 and 5, the first opposing surface 412 of the first support 40 and the second opposing surface 512 of the second support 50 face each other with a gap between them in the axial direction.

[0026] The second shaft portion 52 is a cylindrical part that protrudes from the second fixed surface 511 in the Z2 direction along the central axis C. The second shaft portion 52 is installed coaxially with the second base portion 51. The outer diameter of the second shaft portion 52 is less than the outer diameter D of the second base portion 51. Therefore, as illustrated in Figure 7, when viewed from the axial direction, the outer circumferential surface of the second shaft portion 52 is located inside the outer circumferential surface of the second base portion 51. As illustrated in Figures 2 and 3, a helical screw groove is formed on the outer circumferential surface of the second shaft portion 52, centered on the central axis C.

[0027] As described above, the second support 50 is a rotating body about the central axis C. Therefore, compared to a configuration where the planar shape of the second base 51 is, for example, a polygon (i.e., a configuration where the second support 50 is a non-rotating body), it is easier to reduce the manufacturing cost of the second support 50. For example, the second support 50 can be manufactured by inexpensive rotary machining using a processing device such as a lathe.

[0028] As illustrated in Figure 4, the elastic body 60 is a structure in which a first side wall portion 61, a second side wall portion 62, a first covering portion 63, a second covering portion 64, and a vibration-damping portion 65 are integrally formed. The first side wall portion 61 and the first covering portion 63 are located at the ends of the elastic body 60 in the Z1 direction, and the second side wall portion 62 and the second covering portion 64 are located at the ends of the elastic body 60 in the Z2 direction. The boundaries between each adjacent portion among the multiple portions constituting the elastic body 60 are formed in an arc shape (R shape).

[0029] The vibration isolation section 65 is the part located between the first support 40 and the second support 50. Specifically, the vibration isolation section 65 is located between the first opposing surface 412 and the second opposing surface 512. The vibration isolation section 65 is a columnar part that is elongated in the axial direction and is installed coaxially with the central axis C. The vibration isolation section 65 of the first embodiment is a rectangular prism-shaped part with its corners formed in an arc shape (R shape). That is, the shape of the cross section perpendicular to the central axis C (hereinafter referred to as the "cross section") is a square with each corner formed in an arc shape (R shape).

[0030] The external dimension E of the vibration-damping section 65 in cross-section is constant along the central axis C. The external dimension E is the diameter of the circumscribed circle that circumscribes the cross-section of the vibration-damping section 65. Therefore, the external dimension E can also be expressed as the maximum dimension of the vibration-damping section 65 in cross-section. The external dimension E of the vibration-damping section 65 exceeds the outer diameter D of the first base section 41 and the second base section 51. As described above, in the first embodiment, since the external dimension E of the vibration-damping section 65 is constant along the central axis C, there is an advantage in that the external shape of the vibration-damping section 65 can be simplified.

[0031] As illustrated in Figures 4 and 5, the first side wall portion 61 is a portion that covers the outer circumferential surface of the first base portion 41. Specifically, the first side wall portion 61 is an annular or tubular portion that covers the outer circumferential surface of the first base portion 41 around its entire circumference. As mentioned above, since the first base portion 41 of the first support 40 is circular, the shape of the inner wall surface of the first side wall portion 61 as viewed from the axial direction is circular with the same diameter as the first base portion 41. The surface of the first side wall portion 61 in the Z1 direction (the end face facing the Z1 direction) is located in the same plane as the first fixed surface 411 of the first base portion 41.

[0032] As illustrated in FIG. 6, the outer shape of the first side wall portion 61 viewed from the axial direction is non-circular. The outer shape of the first side wall portion 61 in the first embodiment is a square shape in which each corner portion is formed in an arc shape. Specifically, the outer wall surface of the first side wall portion 61 is composed of a curved surface in which flat portions P1 and curved surface portions Q1 are alternately arranged along the circumferential direction. That is, the flat portion P1 and the curved surface portion Q1 constituting the outer wall surface of the first side wall portion 61 are adjacent to each other. The flat portion P1 is a plane parallel to the central axis C. On the other hand, the curved surface portion Q1 is constituted by a curved surface. Specifically, the curved surface portion Q1 is an arc surface (cylindrical surface) centered on an axis parallel to the central axis C. The radius of curvature of the curved surface portion Q1 is smaller than the radius of curvature of the first base portion 41.

[0033] As described above, while the first base portion 41 of the first support 40 is circular, the outer wall surface of the first side wall portion 61 covering the outer peripheral surface of the first base portion 41 is a polygonal shape including the flat portion P1 and the curved surface portion Q1. Therefore, as illustrated in FIG. 6, the thickness Ta of the first side wall portion 61 in the flat portion P1 is less than the thickness Tb of the first side wall portion 61 in the curved surface portion Q1 (Ta < Tb). The thickness Ta is the distance between the inner wall surface and the outer wall surface (that is, the flat portion P1) of the first side wall portion 61 on a straight line perpendicular to the flat portion P1 centered on the central axis C. The thickness Tb is the distance between the inner wall surface and the outer wall surface (that is, the curved surface portion Q1) of the first side wall portion 61 on a straight line passing through the curved surface portion Q1 centered on the central axis C. The thickness Tb is also expressed as the maximum value of the thickness of the first side wall portion 61. The ratio Tb / Ta of the thickness Tb in the curved surface portion Q1 to the thickness Ta in the flat portion P1 is, for example, 2 or more and 5 or less, and more preferably 3 or more and 4.5 or less. However, the numerical ranges described above are merely examples, and the specific numerical value of the ratio Tb / Ta may be arbitrarily changed.

[0034] In FIG. 6, the outer wall surface of the vibration isolation portion 65 is illustrated by a broken line. As illustrated in FIG. 6, the outer wall surface of the vibration isolation portion 65 is located inside the outer peripheral surface of the first base portion 41 when viewed from the axial direction. Also, the outer wall surface of the vibration isolation portion 65 is located outside the outer peripheral surface of the first shaft portion 42 when viewed from the axial direction. That is, the outer wall surface of the vibration isolation portion 65 is located in an annular region between the outer peripheral surface of the first base portion 41 and the outer peripheral surface of the first shaft portion 42 when viewed from the axial direction.

[0035] As illustrated in Figures 4 and 5, the first covering portion 63 is an annular portion that covers the area along the outer edge of the first opposing surface 412 of the first base portion 41. The first covering portion 63 connects the first side wall portion 61 and the vibration-damping portion 65. Specifically, the first covering portion 63 connects the end of the first side wall portion 61 in the Z2 direction to the end of the vibration-damping portion 65 in the Z1 direction. That is, the outer edge of the first covering portion 63 is connected to the edge of the first side wall portion 61 in the Z2 direction, and the inner edge of the first covering portion 63 is connected to the end of the vibration-damping portion 65 in the Z1 direction. The first covering portion 63 constitutes a step between the outer wall surface of the first side wall portion 61 and the outer wall surface of the vibration-damping portion 65.

[0036] As illustrated in Figures 4 and 5, the second side wall portion 62 is the part that covers the outer circumferential surface of the second base portion 51. Specifically, the second side wall portion 62 is an annular or tubular portion that covers the outer circumferential surface of the second base portion 51 around its entire circumference. As mentioned above, since the second base portion 51 of the second support 50 is circular, the shape of the inner wall surface of the second side wall portion 62 as viewed from the axial direction is circular with the same diameter as the second base portion 51. The surface of the second side wall portion 62 in the Z2 direction (the end face facing the Z2 direction) is located in the same plane as the second fixed surface 511 of the second base portion 51.

[0037] As illustrated in Figure 7, the outer shape of the second side wall portion 62 as viewed from the axial direction is non-circular. In the first embodiment, the outer shape of the second side wall portion 62 is square, with each corner formed in an arc shape. Specifically, the outer wall surface of the second side wall portion 62 is composed of curved surfaces in which flat portions P2 and curved portions Q2 are arranged alternately along the circumferential direction. That is, the flat portions P2 and curved portions Q2 that constitute the outer wall surface of the second side wall portion 62 are adjacent to each other. The flat portion P2 is a plane parallel to the central axis C. On the other hand, the curved portion Q2 is composed of a curved surface. Specifically, the curved portion Q2 is an arc surface (cylindrical surface) centered on an axis parallel to the central axis C. The radius of curvature of the curved portion Q2 is less than the radius of curvature of the second base portion 51.

[0038] As described above, the second base portion 51 of the second support 50 is circular, while the outer wall surface of the second side wall portion 62 covering the outer peripheral surface of the second base portion 51 is a polygonal shape including a flat portion P2 and a curved portion Q2. Therefore, as illustrated in FIG. 7, the thickness Ta of the second side wall portion 62 in the flat portion P2 is less than the thickness Tb of the second side wall portion 62 in the curved portion Q2 (Ta < Tb). The ratio Tb / Ta of the thickness Tb to the thickness Ta is, as described above, for example, 2 or more and 5 or less, and more preferably 3 or more and 4.5 or less. Note that the thickness Tb is also expressed as the maximum value of the thickness of the second side wall portion 62.

[0039] In FIG. 7, the outer wall surface of the vibration-proof portion 65 is illustrated by a broken line. As illustrated in FIG. 7, the outer wall surface of the vibration-proof portion 65 is located inside the outer peripheral surface of the second base portion 51 when viewed in the axial direction. Further, the outer wall surface of the vibration-proof portion 65 is located outside the outer peripheral surface of the second shaft portion 52 when viewed in the axial direction. That is, the outer wall surface of the vibration-proof portion 65 is located in the annular region between the outer peripheral surface of the second base portion 51 and the outer peripheral surface of the second shaft portion 52 when viewed in the axial direction.

[0040] As illustrated in FIGS. 4 and 5, the second covering portion 64 is an annular portion that covers the region along the outer peripheral edge of the second opposing surface 512 of the second base portion 51. The second covering portion 64 connects the second side wall portion 62 and the vibration-proof portion 65. Specifically, the second covering portion 64 connects the end portion in the Z1 direction of the second side wall portion 62 and the end portion in the Z2 direction of the vibration-proof portion 65. That is, the outer peripheral edge of the second covering portion 64 is connected to the edge portion in the Z1 direction of the second side wall portion 62, and the inner peripheral edge of the second covering portion 64 is connected to the end portion in the Z2 direction of the vibration-proof portion 65. The second covering portion 64 constitutes a step between the outer wall surface of the second side wall portion 62 and the outer wall surface of the vibration-proof portion 65.

[0041] Figure 8 is a side view showing the vibration isolation device 30 installed between the first member 11 and the second member 21. As illustrated in Figure 8, the first member 11 includes a first mounting surface 13. The first mounting surface 13 is a plane facing in the Z2 direction. Similarly, the second member 21 includes a second mounting surface 23. The second mounting surface 23 is a plane facing in the Z1 direction. That is, the first mounting surface 13 and the second mounting surface 23 face each other with a gap between them in the axial direction. The vibration isolation device 30 is installed between the first mounting surface 13 and the second mounting surface 23.

[0042] The first shaft portion 42 of the first support 40 is inserted into the first mounting hole 12 of the first member 11. That is, with the first shaft portion 42 inserted into the first mounting hole 12, the first support 40 is fixed to the first member 11. A fastener 71 is used to fix the first support 40 to the first member 11. The fastener 71 is, for example, a nut. Specifically, the first support 40 is fastened to the first member 11 by the engagement of a screw groove formed on the outer circumferential surface of the first shaft portion 42 and a screw groove formed on the inner circumferential surface of the fastener 71. With the first support 40 fixed to the first member 11, the first fixing surface 411 of the first base portion 41 and the surface of the first side wall portion 61 are in close contact with the first installation surface 13 of the first member 11.

[0043] As illustrated in Figures 6 and 8, a plurality of first protrusions 14 are formed on the first mounting surface 13 of the first member 11. Each first protrusion 14 contacts a planar portion P1 of the first side wall portion 61 of the first support 40. Specifically, different first protrusions 14 contact mutually orthogonal planar portions P1 of the first side wall portion 61. The number and position of the first protrusions 14 may be changed as desired.

[0044] During the process of rotating the fastener 71 to fix the first support 40 to the first member 11, a circumferential torque acts on the first support 40. In the first embodiment, the rotation of the first support 40 is suppressed by the contact of the first projection 14 with the planar portion P1 of the first side wall portion 61. Therefore, the possibility of twisting occurring in the vibration-damping portion 65 of the elastic body 60 due to the rotation of the first support 40 can be reduced. In other words, a decrease in vibration-damping performance due to twisting of the vibration-damping portion 65 can be suppressed. As can be understood from the above explanation, the first projection 14 is an element (first rotation suppression portion) for suppressing the rotation of the first support 40 about the central axis C.

[0045] The second shaft portion 52 of the second support 50 is inserted into the second mounting hole 22 of the second member 21. That is, with the second shaft portion 52 inserted into the second mounting hole 22, the second support 50 is fixed to the second member 21. A fastener 72 is used to fix the second support 50 to the second member 21. The fastener 72 is, for example, a nut. Specifically, the second support 50 is fastened to the second member 21 by the engagement of a screw groove formed on the outer circumferential surface of the second shaft portion 52 and a screw groove formed on the inner circumferential surface of the fastener 72. With the second support 50 fixed to the second member 21, the second fixing surface 511 of the second base portion 51 and the surface of the second side wall portion 62 are in close contact with the second installation surface 23 of the second member 21.

[0046] As illustrated in Figures 7 and 8, a plurality of second protrusions 24 are formed on the second mounting surface 23 of the second member 21. Each second protrusion 24 contacts a planar portion P2 of the second side wall portion 62 of the second support 50. Specifically, different second protrusions 24 contact mutually orthogonal planar portions P2 of the second side wall portion 62. The number and position of the second protrusions 24 may be changed as desired.

[0047] In the process of rotating the fastener 72 to fix the second support 50 to the second member 21, a circumferential torque acts on the second support 50. In the first embodiment, the rotation of the second support 50 is suppressed by the contact of the second projection 24 with the planar portion P2 of the second side wall portion 62. Therefore, the possibility of twisting occurring in the vibration-damping portion 65 of the elastic body 60 due to the rotation of the second support 50 can be reduced. In other words, a decrease in vibration-damping performance due to twisting of the vibration-damping portion 65 can be suppressed. As can be understood from the above explanation, the second projection 24 is an element (second rotation suppression portion) for suppressing the rotation of the second support 50 about the central axis C.

[0048] As described above, the first side wall portion 61 functions as an element that suppresses the rotation of the first support 40 by contacting the first projection 14. Similarly, the second side wall portion 62 functions as an element that suppresses the rotation of the second support 50 by contacting the second projection 24. On the other hand, the vibration-damping portion 65 functions as an element that absorbs vibrations between the first support 40 and the second support 50. In other words, in the first embodiment, the function of suppressing rotation (first side wall portion 61 and second side wall portion 62) and the function of absorbing vibrations (vibration-damping portion 65) are realized by different parts of the elastic body 60.

[0049] As described above, in the first embodiment, the thickness Ta of the first sidewall portion 61 in the flat portion P1 is less than the thickness Tb of the first sidewall portion 61 in the curved portion Q1. Therefore, the rigidity of the first sidewall portion 61 in the flat portion P1 is greater than the rigidity of the first sidewall portion 61 in the curved portion Q1. Consequently, compared to a configuration in which the thickness Ta of the first sidewall portion 61 in the flat portion P1 exceeds the thickness Tb of the first sidewall portion 61 in the curved portion Q1, the rotation of the first support 40 can be effectively suppressed by the contact of the first projection 14 of the first sidewall portion 61 with the flat portion P1. The same applies to the second support 50.

[0050] In the first embodiment, as described above, the outer wall surface of the vibration-damping section 65 is located inside the outer circumferential surface of the first foundation section 41 when viewed from the axial direction. With this configuration, compared to the configuration in which the outer wall surface of the vibration-damping section 65 is located outside the outer circumferential surface of the first foundation section 41, vibrations from the first support 40 or the second support 50 are effectively transmitted to the elastic body 60. Therefore, the propagation of vibrations between the first structure 10 and the second structure 20 can be effectively suppressed. In addition, compared to the configuration in which the outer wall surface of the vibration-damping section 65 is located outside the outer circumferential surface of the first foundation section 41, there is also the advantage that the amount of material used to form the elastic body 60 can be reduced. Although the above description has focused on the first support 40, the same effect can be achieved with the second support 50 as well.

[0051] Furthermore, in the first embodiment, the outer wall surface of the vibration-damping section 65 is located outside the outer circumferential surface of the first shaft section 42 when viewed from the axial direction. Compared to the embodiment in which the outer wall surface of the vibration-damping section 65 is located inside the outer circumferential surface of the first shaft section 42, the vibration of the first structure 10 or the second structure 20 can be effectively absorbed by the elastic body 60. Therefore, the propagation of vibrations between the first structure 10 and the second structure 20 can be effectively suppressed. Although the above description has focused on the first support 40, the same effect can be achieved with the second support 50 as well.

[0052] B: Second Embodiment A second embodiment will now be described. For elements whose function is the same as in the first embodiment, the same reference numerals as in the first embodiment will be used, and detailed descriptions of each will be omitted as appropriate.

[0053] Figure 9 is a perspective view of the vibration isolation device 30 in the second embodiment. As illustrated in Figure 9, the vibration isolation portion 65 of the elastic body 60 in the second embodiment is a cylindrical portion. That is, the external dimension E in the cross-section of the vibration isolation portion 65 is the diameter of the vibration isolation portion 65. The external dimension E of the vibration isolation portion 65 is constant along the central axis C. Similar to the first embodiment, the outer wall surface of the vibration isolation portion 65 is located inside the outer circumferential surface of the first base portion 41 when viewed from the axial direction, and outside the outer circumferential surface of the first shaft portion 42 when viewed from the axial direction.

[0054] The same effects as in the first embodiment are achieved in the second embodiment as well. As can be understood from the examples of the first and second embodiments, since the elastic body 60 includes a first side wall portion 61, a second side wall portion 62, and a vibration-damping portion 65, the shape of the vibration-damping portion 65 (especially the cross-sectional shape) can be selected independently of the outer shapes of the first side wall portion 61 and the second side wall portion 62. In the configuration of Patent Document 1, the elastic member is limited to a shape (so-called drum shape) in which the diameter changes continuously depending on the axial position such that the diameter of the central part in the axial direction is less than the diameter of both ends. In contrast to the configuration of Patent Document 1, according to the present disclosure, as illustrated in the examples of the first and second embodiments, it is possible to improve the degree of freedom of the shape (e.g., cross-sectional shape or dimensions, etc.) of the vibration-damping portion 65. For example, the shape of the vibration-damping portion 65 is selected so as to ensure the second moment of area necessary for absorbing vibrations, depending on the vibration characteristics assumed for the first structure 10 or the second structure 20. The vibration-damping portion 65 of the elastic body 60 may be shaped such that the diameter of the axial central portion is less than the diameters of the ends.

[0055] C: Variant The following are examples of specific modifications that may be added to the embodiments exemplified above. Two or more embodiments may be arbitrarily selected from the following examples and merged as appropriate, provided they do not contradict each other.

[0056] (1) In the embodiments described above, the first side wall portion 61 is shown as having a square shape including arc-shaped corners, but the shape of the first side wall portion 61 can be changed arbitrarily. For example, the total number of corners of the polygon constituting the first side wall portion 61 can be changed arbitrarily. Also, the shape of the first side wall portion 61 may be, for example, an elongated shape in a specific direction when viewed from the axial direction (e.g., oval). However, from the viewpoint of suppressing the rotation of the first support 40 by contact with the first projection 14, an embodiment in which the outer wall surface of the first side wall portion 61 includes a flat portion P1 is preferred. In the above description, the focus has been on the first support 40, but similar modifications can be applied to the second support 50.

[0057] (2) In the embodiments described above, an example was given in which the first projection 14 of the first member 11 contacts the planar portion P1 of the first side wall portion 61 of the elastic body 60. However, the structure that suppresses the rotation of the first support 40 by contacting the planar portion P1 of the first side wall portion 61 is not limited to the first projection 14 exemplified in the embodiments described above. For example, in the process of rotating the fastener 71 to fix the first support 40 to the first member 11, the rotation of the first support 40 may be suppressed by bringing a jig separate from the vibration isolation mechanism 100 into contact with the planar portion P1 of the first side wall portion 61. In other words, the first projection 14 may be omitted. The first projection 14 in the first embodiment and the jig that contacts the planar portion P1 of the first side wall portion 61 are collectively expressed as an element (first rotation suppression part) for suppressing the rotation of the first support 40 about the central axis C.

[0058] In the above explanation, we have conveniently focused on the first support 40, but similar modifications can be applied to the second support 50. For example, in the process of rotating the fastener 72 to fix the second support 50 to the second member 21, the rotation of the second support 50 may be suppressed by bringing a jig, separate from the vibration damping mechanism 100, into contact with the flat portion P2 of the second side wall 62. In other words, the second projection 24 may be omitted. In the first embodiment, the second projection 24 and the jig that contacts the flat portion P2 of the second side wall 62 are collectively represented as elements (second rotation suppression part) for suppressing the rotation of the second support 50 about the central axis C.

[0059] (3) The notation "nth" (where n is a natural number) in this application is used solely as a formal and convenient label to distinguish each element in notation and has no substantive meaning whatsoever. Therefore, there is no room for restrictive interpretation of the position or manufacturing order of each element based on the notation "nth".

[0060] D: Note From the forms exemplified above, the following configuration can be understood, for example.

[0061] A vibration isolation device according to one aspect of the present disclosure (Aspect 1) is a vibration isolation device installed between a first member and a second member, comprising a first support fixed to the first member, a second support fixed to the second member, and an elastic body connecting the first support and the second support, wherein the first support includes a circular first base portion including a first fixed surface, and a first shaft portion protruding from the first fixed surface along a central axis and inserted into a mounting hole of the first member, the elastic body includes a first side wall portion covering the outer circumferential surface of the first base portion, and a vibration isolation portion located between the first support and the second support, the outer wall surface of the first side wall portion includes a planar portion which is a plane that contacts a first rotation suppression portion for suppressing the rotation of the first support about the central axis. In the above aspect, since the first base portion of the first support is circular, the manufacturing cost of the first support can be easily reduced compared to a form in which the planar shape of the first base portion is, for example, polygonal. On the other hand, the first side wall portion of the elastic body that covers the outer circumferential surface of the first base portion includes a flat portion that is in contact with the first rotation suppression portion. The rotation of the first support is suppressed by the contact of the first rotation suppression portion with the flat portion of the first side wall portion. Therefore, in the process of fixing the first support to the first member with the first shaft portion inserted into the mounting hole of the first member, the possibility of twisting occurring in the vibration-damping portion of the elastic body due to the rotation of the first support can be reduced. In other words, a decrease in vibration-damping performance due to twisting of the vibration-damping portion can be suppressed.

[0062] In a specific example of Embodiment 1 (Embodiment 2), the outer wall surface of the first side wall further includes a curved surface which is adjacent to the circumferentially oriented curved surface of the flat surface, and the thickness of the first side wall in the flat surface is less than the thickness of the first side wall in the curved surface. In the above embodiment, since the thickness of the first side wall in the flat surface is less than the thickness of the first side wall in the curved surface, the rigidity of the flat surface of the first side wall exceeds the rigidity of the curved surface of the first side wall. Therefore, compared to a configuration in which the thickness of the first side wall in the flat surface exceeds the thickness of the first side wall in the curved surface, the rotation of the first support can be effectively suppressed by the contact of the first rotation suppression part with the flat surface of the first side wall.

[0063] In a specific example of Embodiment 1 or Embodiment 2 (Embodiment 3), the outer shape of the first side wall as viewed from the direction of the central axis is a polygonal shape with arc-shaped corners. According to the above embodiments, the outer shape of the first side wall can be simplified.

[0064] In any specific example of Embodiments 1 to 3 (Embodiment 4), the external dimensions of the vibration-isolating portion in a cross-section perpendicular to the central axis are constant along the central axis. According to the above embodiments, the external shape of the vibration-isolating portion can be simplified.

[0065] In any specific example of Embodiments 1 to 4 (Embodiment 5), the outer wall surface of the vibration-isolating part is located inside the outer circumferential surface of the first foundation when viewed from the direction of the central axis. According to the above embodiments, compared to the embodiment in which the outer wall surface of the vibration-isolating part is located outside the outer circumferential surface of the first foundation, vibrations of the first support or the second support are effectively transmitted to the elastic body. Therefore, the propagation of vibrations between the first member and the second member can be effectively suppressed. In addition, compared to the embodiment in which the outer wall surface of the vibration-isolating part is located outside the outer circumferential surface of the first foundation, there is also the advantage that the amount of material used to form the elastic body can be reduced.

[0066] In any specific example of Embodiments 1 to 5 (Embodiment 6), the outer wall surface of the vibration-damping section is located outside the outer circumferential surface of the first shaft section when viewed from the direction of the central axis. In this embodiment, compared to the embodiment in which the outer wall surface of the vibration-damping section is located inside the outer circumferential surface of the first shaft section, vibrations of the first support or the second support can be effectively absorbed by the elastic body. Therefore, the propagation of vibrations between the first member and the second member can be effectively suppressed.

[0067] In any specific example of Embodiments 1 to 6 (Embodiment 7), the second support includes a circular second base portion including a second fixed surface, and a second shaft portion projecting from the second fixed surface along a central axis and inserted into a mounting hole of the second member. The elastic body further includes a second side wall portion covering the outer circumferential surface of the second base portion, and the outer wall surface of the second side wall portion includes a planar portion which is a plane that contacts a second rotation suppression portion for suppressing the rotation of the second support about the central axis. In the above embodiment, since the second base portion of the second support is circular, the manufacturing cost of the second support is easier to reduce compared to an embodiment in which the planar shape of the second base portion is, for example, polygonal. On the other hand, the second side wall portion of the elastic body that covers the outer circumferential surface of the second base portion includes a planar portion which is a plane that contacts the second rotation suppression portion. The rotation of the second support is suppressed by the contact of the second rotation suppression portion with the planar portion of the second side wall portion. Therefore, in the process of fixing the second support to the second member with the second shaft inserted into the mounting hole of the second member, the possibility of twisting occurring in the elastic vibration-damping part due to the rotation of the second support can be reduced. As described above, the deterioration of vibration-damping performance caused by twisting of the vibration-damping part can be suppressed.

[0068] A vibration isolation mechanism according to one aspect of the present disclosure comprises a first member and a second member, and a vibration isolation device installed between the first member and the second member, wherein the vibration isolation device comprises a first support fixed to the first member, a second support fixed to the second member, and an elastic body connecting the first support and the second support, wherein the first support includes a circular first base portion including a first fixed surface, and a first shaft portion protruding from the first fixed surface along a central axis and inserted into a mounting hole of the first member, wherein the elastic body includes a first side wall portion covering the outer circumferential surface of the first base portion, and a vibration isolation portion located between the first support and the second support, wherein the outer wall surface of the first side wall portion includes a planar portion which is a plane that contacts a first rotation suppression portion for suppressing the rotation of the first support about the central axis. [Explanation of Symbols]

[0069] 100…Vibration isolation mechanism, 10…First structure, 11…First member, 12…First mounting hole, 13…First mounting surface, 14…First projection, 20…Second structure, 21…Second member, 22…Second mounting hole, 23…Second mounting surface, 24…Second projection, 30…Vibration isolation device, 40…First support, 41…First base part 41, 411…First fixing surface, 412… First opposing surface, 42...First shaft portion, 50...Second support, 51...Second base portion, 511...Second fixed surface, 512...Second opposing surface, 52...Second shaft portion, 60...Elastic body, 61...First side wall portion, 62...Second side wall portion, 63...First covering portion, 64...Second covering portion, 65...Vibration isolation portion, P1...Flat portion, Q1...Curved portion, P2...Flat portion, Q2...Curved portion.

Claims

1. A vibration isolation device installed between a first member and a second member, A first support fixed to the first member, A second support fixed to the second member, It comprises an elastic body connecting the first support and the second support, The first support is A circular first base including a first fixed surface, It includes a first shaft portion that protrudes from the first fixed surface along the central axis and is inserted into the mounting hole of the first member, The elastic body is The first side wall portion covers the outer circumferential surface of the first foundation portion, It includes a vibration-damping section located between the first support and the second support, The outer wall surface of the first side wall includes a flat portion which is a plane that contacts the first rotation suppression portion for suppressing the rotation of the first support about the central axis. Vibration isolation device.

2. The outer wall surface of the first side wall portion further includes a curved surface portion which is a curved surface adjacent to the circumferential direction of the flat portion, The thickness of the first side wall in the flat portion is less than the thickness of the first side wall in the curved portion. Vibration isolation device according to claim 1.

3. The outer shape of the first side wall portion, as viewed from the direction of the central axis, is a polygonal shape with arc-shaped corners. Vibration isolation device according to claim 1.

4. The external dimensions of the vibration-damping section in a cross-section perpendicular to the central axis are constant along the central axis. Vibration isolation device according to claim 1.

5. The outer wall surface of the vibration-damping section is located inside the outer surface of the first foundation section when viewed from the direction of the central axis. Vibration isolation device according to claim 1.

6. The outer wall surface of the vibration-damping section is located outside the outer surface of the first shaft portion when viewed from the direction of the central axis. Vibration isolation device according to claim 1.

7. The second support is, A circular second base including a second fixed surface, It includes a second shaft portion that protrudes from the second fixed surface along the central axis and is inserted into the mounting hole of the second member, The elastic body is It further includes a second side wall portion that covers the outer circumferential surface of the second foundation portion, The outer wall surface of the second side wall includes a flat portion which is a plane that contacts the second rotation suppression portion for suppressing the rotation of the second support about the central axis. Vibration isolation device according to claim 1.

8. First member and second member, The device comprises a vibration isolation device installed between the first member and the second member, The vibration isolation device is, A first support fixed to the first member, A second support fixed to the second member, It comprises an elastic body connecting the first support and the second support, The first support is A circular first base including a first fixed surface, It includes a first shaft portion that protrudes from the first fixed surface along the central axis and is inserted into the mounting hole of the first member, The elastic body is The first side wall portion covers the outer circumferential surface of the first foundation portion, It includes a vibration-damping section located between the first support and the second support, The outer wall surface of the first side wall includes a flat portion which is a plane that contacts the first rotation suppression portion for suppressing the rotation of the first support about the central axis. Vibration isolation mechanism.

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