Cylindrical vibration isolator

Abstract

The present application provides a new structure of cylindrical vibration isolator, which can achieve high dynamic spring characteristics under small input and low dynamic spring characteristics under large input with high precision according to required characteristics. In the cylindrical vibration isolator (10), the inner shaft member (16) and the outer cylinder member (18) are connected through the main rubber elastic body (20), the outer cylinder member is installed in the inner insertion state capable of sliding along the axial direction relative to the mounting cylinder portion (50), the outer cylinder member is divided in the circumferential direction and can be deformed or displaced in the radial direction, a pair of fastening members (14, 14) are arranged on both sides of the axial direction of the main rubber elastic body, the main rubber elastic body is fixedly installed on the inner circumferential surface of the outer cylinder member, and the adjusting elastic body (38) for pressing the fastening member on both sides in the axial direction is integrally formed with the main rubber elastic body, and the sliding resistance between the outer circumferential surface of the outer cylinder member and the inner circumferential surface of the mounting cylinder portion (50) in the axial direction can be set according to the pressing force of the fastening member on the adjusting elastic body.

Description

Technical Field

[0001] This invention relates to a cylindrical vibration damping device for use in suspension mechanisms of motor vehicles, etc. Background Technology

[0002] Previously, cylindrical vibration damping devices for motor vehicle suspension mechanisms and the like were known. These cylindrical vibration damping devices have a structure in which an inner shaft member and an outer cylinder member are elastically connected using a main rubber elastomer. Examples of cylindrical vibration damping devices include the bushing described in Japanese Patent Application Publication No. 63-051943 (Patent Document 1). Furthermore, by installing the inner shaft member and the outer cylinder member onto each of the vibration-damping connection members, these vibration-damping connection members are connected in a vibration-damping manner.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Published in Japanese Patent Application Publication No. 63-051943 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, while telescopic dampers, for example, improve ride stability by increasing the axial spring constant at the initial input stage, a large axial spring constant can worsen vibration conditions and reduce ride comfort. Therefore, it is preferable that the axial spring constant of the telescopic damper used in the suspension mechanism increases rapidly at the initial input stage to achieve good ride stability, and is less suppressed under large input conditions that affect ride comfort.

[0008] In response, Patent Document 1 describes an outer cylinder member installed in an inserted state on a mounting cylinder (cylinder body). When a predetermined axial load is applied, the outer cylinder member slides axially relative to the mounting cylinder. Consequently, under low-input conditions where the outer cylinder member does not slide relative to the mounting cylinder, the axial spring constant increases rapidly. Furthermore, under high-input conditions where the outer cylinder member slides relative to the mounting cylinder, the increase in the axial spring constant is suppressed, thus providing good ride comfort based on low-motion spring characteristics.

[0009] However, in the structure of Patent Document 1, it is difficult to set the load threshold for the outer cylinder component sliding out relative to the mounting cylinder, making it difficult to accurately balance driving performance and ride comfort. Furthermore, it is difficult to adjust the spring characteristics of the cylindrical vibration damping device after manufacturing, making it difficult to meet different spring characteristic requirements with a single cylindrical vibration damping device.

[0010] The problem solved by the present invention is to provide a novel cylindrical vibration damping device that can achieve high dynamic spring characteristics when the input is small and low dynamic spring characteristics when the input is large, respectively, according to the required characteristics, so as to obtain the target spring characteristics.

[0011] means for solving problems

[0012] Hereinafter, preferred embodiments for mastering the present invention will be described. However, the embodiments described below are merely illustrative and can be appropriately combined with each other. Furthermore, the multiple constituent elements described in each embodiment can be identified and used as independently as possible, and can also be appropriately combined with any constituent element described in other embodiments. Therefore, the present invention is not limited to the embodiments described below, and various other embodiments can be implemented.

[0013] The first method is a cylindrical vibration damping device in which an inner shaft member and an outer cylinder member are connected by a main body rubber elastomer. The outer cylinder member is installed in an inserted state relative to the mounting cylinder in an axially sliding state. At least a portion of the outer cylinder member is divided in the circumferential direction so that it can deform or displace in the radial direction. A pair of fastening members are arranged on both axial sides of the main body rubber elastomer. The main body rubber elastomer is fixedly installed on the inner circumferential surface of the outer cylinder member. An adjusting elastomer that presses the pair of fastening members on both axial sides is integrally formed with the main body rubber elastomer. The axial sliding resistance between the outer circumferential surface of the outer cylinder member and the inner circumferential surface of the mounting cylinder can be set according to the pressing force of the pair of fastening members on the adjusting elastomer.

[0014] According to the cylindrical vibration damping device formed in accordance with this method, the greater the amount of compression deformation of the adjusting elastic body caused by the contact of the fastening member, the stiffer the spring in the axial direction of the cylindrical vibration damping device. Therefore, by appropriately setting the amount of compression deformation of the adjusting elastic body caused by the fastening member, the spring characteristics of the cylindrical vibration damping device can be tuned.

[0015] Furthermore, by allowing the outer cylinder component to slide axially relative to the mounting cylinder, it is possible to utilize both high dynamic spring characteristics for small axial inputs when the outer cylinder component does not slide relative to the mounting cylinder and low dynamic spring characteristics for large axial inputs when the outer cylinder component slides relative to the mounting cylinder.

[0016] The sliding resistance acting between the outer cylinder member and the mounting cylinder can be set by adjusting the axial distance between the opposing surfaces of a pair of fastening members and by adjusting the amount of compression deformation of the adjusting elastomer caused by the contact of the fastening members. Therefore, it is possible to easily and accurately set the threshold for switching between the high dynamic spring characteristics that occur when the outer cylinder member does not slide relative to the mounting cylinder and the low dynamic spring characteristics that occur when the outer cylinder member slides relative to the mounting cylinder.

[0017] The second method is a cylindrical vibration damping device according to the first method, wherein the fastening member and the outer cylinder member are axially opposed, and the adjusting elastomer is arranged on the axially opposed surface of the outer cylinder member and the fastening member, and the main rubber elastomer and the adjusting elastomer are integrally formed by connecting rubber on the inner circumference of the outer cylinder member.

[0018] According to the cylindrical vibration damping device formed in accordance with this method, since the adjusting elastomer is provided on the axial opposing surface of the outer cylinder member relative to the fastening member, the adjusting elastomer is sandwiched between the opposing surfaces of the outer cylinder member and the fastening member, thereby enabling efficient compression deformation.

[0019] Furthermore, the adjusting elastomer is integrally connected to the main rubber elastomer via a connecting rubber on the inner circumference of the outer cylinder component. Thus, when the adjusting elastomer undergoes radial bulging deformation accompanied by axial compressive deformation, the deformation of the adjusting elastomer is transmitted to the main rubber elastomer via the connecting rubber. Therefore, when the adjusting elastomer is compressed and deformed by the pressure of the fastening member, the main rubber elastomer deforms in a manner that pushes the outer cylinder component outwards, pressing the outer cylinder component against the mounting cylinder. Therefore, the sliding resistance of the outer cylinder component relative to the mounting cylinder can be set based on the amount of compression deformation of the adjusting elastomer.

[0020] The third method is the cylindrical vibration damping device according to the second method, wherein the outer cylinder member is formed as a groove-shaped cross-section with an opening towards the inner periphery, the outer cylinder member has a peripheral wall portion extending along the axial direction and a pair of bearing portions protruding towards the inner periphery from both axial ends of the peripheral wall portion, the adjusting elastomer is fixedly installed on the axial outer surface of the pair of bearing portions respectively, and the inner side of the outer cylinder member surrounded by the peripheral wall portion and the pair of bearing portions is filled with the main rubber elastomer.

[0021] According to the cylindrical vibration damping device formed in accordance with this method, since the main rubber elastomer is arranged in a filled state inside the outer cylinder member which is formed in a groove-shaped cross section, the rubber volume of the main rubber elastomer can be largely ensured on the inner circumference of the outer cylinder member, thereby efficiently obtaining the force acting on the outer cylinder member towards the outer circumference transmitted from the self-adjusting elastomer to the main rubber elastomer.

[0022] By forming the outer cylinder component into a groove-shaped section, the axial alignment of the outer cylinder component and the fastening component can be largely ensured by utilizing a pair of bearing parts constituting the sidewall. This allows for an increase in the fixed installation strength of the adjustable elastomer relative to the outer cylinder component, and enables the shape and size of the adjustable elastomer to be set with a greater degree of freedom.

[0023] The fourth method is a cylindrical vibration damping device according to any one of the first to third methods, wherein the fastening member is formed in the shape of an annular plate, and the inner circumferential portion of the fastening member has a positioning portion that is axially positioned relative to the inner shaft member.

[0024] According to the cylindrical vibration damping device formed in accordance with this method, the positioning of the fastening member relative to the inner shaft member in the axial direction by the positioning part allows for high-precision setting of the amount of compression deformation of the adjusting elastomer caused by the pressure of the fastening member.

[0025] The fifth method is the cylindrical vibration damping device according to the fourth method, wherein the inner shaft member has a specified member, the specified member is disposed between the axial opposing surfaces of the pair of fastening members, and specifies the distance between the axial opposing surfaces of the pair of fastening members, and the abutting portion of the pair of fastening members that abuts against the specified member is the positioning portion.

[0026] According to the cylindrical vibration damping device formed in accordance with this method, by using the axial length of the specified member to specify the distance between the axially opposing surfaces of a pair of fastening members, the amount of compressive deformation of the adjusting elastomer caused by the fastening member can be set with high precision.

[0027] The sixth method is a cylindrical vibration damping device according to the fourth or fifth method, wherein the positioning part of the fastening member is composed of an inner abutting part that abuts against the inner shaft member from the outer side of the axial direction, and an elastic body abutting part that abuts against the adjusting elastic body from the outer side of the outer peripheral portion of the fastening member is provided, and the abutting surfaces of the inner abutting part and the elastic body abutting part in the fastening member that abut against the adjusting elastic body are at different positions in the axial direction.

[0028] According to the cylindrical vibration damping device formed in accordance with this method, by setting the contact surface of the inner contact portion of the fastening member that abuts against the inner shaft member and the contact surface of the elastic body contact portion that abuts against the adjusting elastic body at different positions in the axial direction, the amount of compression deformation of the adjusting elastic body caused by the contact of the fastening member can also be adjusted.

[0029] The seventh method is a cylindrical vibration damping device according to any one of the first to sixth methods, wherein the cylindrical vibration damping device has a cylindrical body, which is fixedly assembled to the vibration damping connection object member to form the mounting cylindrical part, the outer cylindrical member is installed in the cylindrical body in an in-line state that can slide along the axial direction, and the cylindrical vibration damping device is provided with an anti-detachment part that limits the amount of movement caused by the sliding of the outer cylindrical member relative to the cylindrical body in the axial direction.

[0030] According to the cylindrical vibration damping device formed in accordance with this method, the outer cylinder component can slide relative to the cylindrical body, and the anti-detachment part can prevent the outer cylinder component from falling off the cylindrical body.

[0031] Invention Effects

[0032] According to the present invention, the high-motion spring characteristics under small input and the low-motion spring characteristics under large input can be realized with high precision according to the required characteristics, thereby obtaining the target spring characteristics. Attached Figure Description

[0033] Figure 1 This is a cross-sectional view showing the bushing as a first embodiment of the present invention.

[0034] Figure 2 It constitutes Figure 1 A perspective view of the integrally vulcanized molded bushing shown.

[0035] Figure 3 yes Figure 1 The front view of the integrally vulcanized molded article shown.

[0036] Figure 4 yes Figure 1 The cross-sectional view of the integrally vulcanized molded article shown is equivalent to Figure 5 A diagram of section IV-IV.

[0037] Figure 5 yes Figure 3 VV sectional view.

[0038] Figure 6 It means Figure 1 The load-deflection characteristic curve of the bushing is shown.

[0039] Figure 7 This is a cross-sectional view showing the bushing as a second embodiment of the present invention.

[0040] Figure 8 This is a perspective view of an integrally vulcanized molded article constituting a bushing as another embodiment of the present invention.

[0041] Figure 9 yes Figure 8A cross-sectional view of the integrally vulcanized molded article shown.

[0042] Figure 10 This is a cross-sectional view showing part of a bushing as part of another embodiment of the present invention.

[0043] Figure 11 This is a cross-sectional view showing part of a bushing as part of another embodiment of the present invention.

[0044] Explanation of reference numerals in the attached figures

[0045] 10: Bushing (first embodiment, cylindrical vibration damping device);

[0046] 12: Bushing body;

[0047] 14: Fastening components;

[0048] 16: Inner shaft component;

[0049] 18: Outer cylinder components;

[0050] 20: Main body rubber elastomer;

[0051] 22: Fixed installation components;

[0052] 24: Inner cylinder components;

[0053] 26: External structural metal parts;

[0054] 28: Bottom wall (peripheral wall);

[0055] 30: Side wall (bearing part);

[0056] 32: Inner peripheral part;

[0057] 34: Peripheral part;

[0058] 35: One-piece vulcanized molded product;

[0059] 36: Incision;

[0060] 38: Adjusting the elastomer;

[0061] 40: Connecting rubber;

[0062] 42: Positioning section;

[0063] 44: Elastomer contact portion;

[0064] 46: Bolted components;

[0065] 48: Nut;

[0066] 50: Outer sleeve (installation sleeve part);

[0067] 52: Reduction section (anti-detachment section);

[0068] 54: Armband;

[0069] 60: Bushing (Second embodiment, cylindrical vibration damping device);

[0070] 62: Bushing body;

[0071] 64: Fastening components;

[0072] 66: Inner shaft component;

[0073] 68: Inner contact part (positioning part);

[0074] 70: One-piece vulcanized molded product (another method);

[0075] 72: Outer cylinder components;

[0076] 74: Main body rubber elastomer;

[0077] 80: Bushing (another type);

[0078] 82: Outer cylinder components;

[0079] 84: Main body rubber elastomer;

[0080] 90: Bushing (another type);

[0081] 92: Fastening components. Detailed Implementation

[0082] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0083] exist Figure 1 In the first embodiment of the cylindrical vibration damping device according to the invention, a motor vehicle bushing 10 is shown in a vehicle-mounted configuration. The bushing 10 has a structure in which a pair of fastening members 14, 14 are mounted on the bushing body 12. In the following description, the vertical direction generally refers to... Figure 1 The up and down directions and the left and right directions refer to... Figure 1 The orthogonal direction of the paper (described later) Figure 3 The left-right direction), and the front-back direction refers to the axial direction. Figure 1 The left and right directions in the middle.

[0084] The bushing body 12 has an inner shaft member 16 and an outer cylinder member 18 that are elastically connected by a main body rubber elastomer 20. In this embodiment, the bushing body 12 is formed in a plane-symmetrical shape about a plane orthogonal to the axial direction. In addition, the bushing body 12 is formed in a rotationally symmetrical shape about a central axis of 180°.

[0085] In this embodiment, the inner shaft member 16 is generally cylindrical in shape and consists of a fixed mounting member 22 fixedly mounted on the inner circumferential surface of the main rubber elastomer 20 and an inner cylinder member 24 disposed on the inner circumferential side of the fixed mounting member 22 as a defined member. Figures 2-5 As shown, the fixed mounting component 22 is formed into a generally cylindrical shape, with the axial ends of its inner circumferential surface facing outwards and its diameter increasing. For example... Figure 1 As shown, the inner cylinder member 24 is formed into a generally cylindrical shape with a diameter smaller than that of the fixed mounting member 22, is thicker in the radial direction than the fixed mounting member 22, and has a larger axial dimension than the fixed mounting member 22. Both the fixed mounting member 22 and the inner cylinder member 24 are made of metal, and the inner cylinder member 24 is inserted into the fixed mounting member 22 in a press-fit state.

[0086] The outer cylinder component 18 is generally formed into a cylindrical shape, such as... Figures 2-5 As shown, it is composed of a pair of outer structural metal parts 26, 26 arranged radially opposite each other. The outer structural metal part 26 has a U-shaped groove-shaped cross section opening towards the inner circumference, extending circumferentially for less than half a circumference. More specifically, the outer structural metal part 26 has a bottom wall 28 as a cylindrical circumferential wall portion, and a pair of side walls 30, 30 as bearing portions protruding towards the inner circumference at both axial ends of the bottom wall 28. The pair of outer structural metal parts 26, 26 are arranged such that they radially sandwich the inner shaft member 16, and the outer cylindrical member 18 is inserted into the inner shaft member 16. The circumferential ends of the pair of outer structural metal parts 26, 26 are separated from each other in the circumferential direction, and the outer cylindrical member 18 is divided at two circumferential locations. The outer cylindrical member 18 is formed with a plane-symmetric shape about a plane orthogonal to the axial direction. In addition, the outer cylindrical member 18 is formed with a rotationally symmetric shape about a central axis of 180°.

[0087] The main rubber elastomer 20 is formed in a ring shape, such as Figure 5 As shown, the inner circumferential portion 32 is thinner than the outer circumferential portion 34 in the axial direction. The axial width dimension of the inner circumferential portion 32 of the main body rubber elastomer 20 is smaller than the distance between the opposing surfaces of a pair of sidewalls 30, 30 in the outer cylinder member 18.

[0088] The wider outer peripheral portion 34 of the main rubber elastomer 20 is fixedly mounted on the inner surface of the outer cylinder member 18, which has a groove-shaped cross-section. The inner side of the groove of the outer cylinder member 18, which is surrounded by the bottom wall 28 and the side walls 30, 30, is filled by the outer peripheral portion 34 of the main rubber elastomer 20. The main rubber elastomer 20 is fixedly mounted on the inner peripheral surface of the outer cylinder member 18. The inner peripheral portion 32 of the main rubber elastomer 20 protrudes inward from the outer cylinder member 18, and its inner peripheral surface is fixedly mounted on the fixing mounting member 22 that constitutes the inner shaft member 16. In this embodiment, the main rubber elastomer 20 is formed as an integral vulcanized molded product 35 having the fixing mounting member 22 and the outer cylinder member 18.

[0089] like Figure 3 , Figure 4 As shown, the main rubber elastomer 20 has cutouts 36, 36 that open outwards between the outer structural metal parts 26, 26 in the circumferential direction. The bottom of the inner surface of the cutout 36, serving as the inner circumferential surface, extends axially in a V-shaped cross-section, and the two circumferentially separated sides extend laterally in the left and right directions, respectively, and expand substantially parallel to each other in the circumferential direction. Figure 4 As shown, in the portion of the main rubber elastomer 20 where the cut 36 is formed, only the inner circumferential end of the inner circumferential portion 32 is continuous in the circumferential direction.

[0090] like Figure 5 As shown, an adjusting elastic body 38 is fixedly installed on the side wall 30 of the outer structural metal part 26 constituting the outer cylinder component 18. The adjusting elastic body 38 is formed of rubber elastomer and is fixedly installed on the axial outer surface of the side wall 30, substantially covering the entire axial outer surface of the side wall 30. The adjusting elastic body 38 is continuous with the main rubber elastomer 20 through the connecting rubber 40 covering the inner circumferential surface of the side wall 30, and is integrally formed with the main rubber elastomer 20 through the connecting rubber 40. The adjusting elastic body 38 integrally formed with the main rubber elastomer 20 is provided on both axial sides of the main rubber elastomer 20. The adjusting elastic body 38 is fixedly installed on a pair of side walls 30, 30 respectively.

[0091] In this embodiment, the outer cylinder member 18 has a groove-shaped cross-section, and an adjusting elastomer 38 is fixedly installed on the axial outer surface of the sidewall 30 that extends approximately perpendicular to the axis. Therefore, the fixed installation area of ​​the adjusting elastomer 38 relative to the outer cylinder member 18 can be greatly ensured, thereby improving the fixed installation strength. Furthermore, the size and shape of the adjusting elastomer 38 can be set with a large degree of freedom.

[0092] like Figure 1 As shown, a pair of fastening members 14, 14 are arranged on both axial sides of the bushing body 12. The fastening member 14 is an annular plate-shaped component, and in this embodiment, it is integrally formed with a substantially constant thickness. The inner peripheral end of the fastening member 14 becomes a positioning portion 42 that coincides axially with the inner cylinder member 24, and the outer peripheral end becomes an elastic body abutment portion 44 that is pressed axially relative to the adjusting elastic body 38. In this embodiment, the positioning portion 42 and the elastic body abutment portion 44 of the fastening member 14 extend in a direction perpendicular to the axis on substantially the same plane. The inner diameter of the fastening member 14 is substantially the same as the inner diameter of the inner cylinder member 24, and its outer diameter is larger than the inner diameter of the side wall 30 of the outer cylinder member 18 and smaller than the outer diameter of the bottom wall 28 of the outer cylinder member 18. In this embodiment, the outer diameter of the fastening member 14 is substantially the same as the inner diameter of the bottom wall 28 of the outer cylinder member 18.

[0093] The positioning portions 42 at the inner peripheral ends of a pair of fastening members 14, 14 coincide with the inner cylinder member 24 of the inner shaft member 16 from both axial sides. The fastening members 14, 14, coinciding with the inner cylinder member 24, fasten the positioning portions 42, 42 axially inward by bolt members 46 inserted into the inner shaft member 16 and nuts 48 screwed into the bolt members 46. The positioning portions 42, 42 press against the inner cylinder member 24, which serves as a defined component, from both axial sides. Thus, the fastening members 14, 14 are fixed to the inner shaft member 16 and are arranged to protrude outward from the inner shaft member 16. Furthermore, the fastening members 14, 14 are axially positioned relative to the inner shaft member 16 by the abutment of the positioning portions 42, 42 against the inner cylinder member 24, and the distance between the axially opposing surfaces of the fastening members 14, 14 is defined by the axial length dimension of the inner cylinder member 24. The elastic abutment portions 44, 44 of the fastening members 14, 14 are disposed on both axial sides of the main rubber elastic body 20 and are disposed opposite to the side walls 30, 30 of the outer cylinder members 18 in the axial direction. An adjusting elastic body 38 integrally formed with the main rubber elastic body 20 is disposed on the axially opposite surface of the side walls 30, 30 of the outer cylinder members 18 to the elastic abutment portions 44, 44.

[0094] Bolt member 46 forms part of or is mounted on one of the vibration-damping connection components. Furthermore, bushing 10 is mounted on one of the vibration-damping connection components by mounting bushing body 12 and a pair of fastening members 14, 14 to one end of bolt member 46. It should be noted that examples of vibration-damping connection components include vehicle body, subframe (suspension components), etc.

[0095] An outer sleeve 50, which forms the mounting sleeve portion, is installed on the outer sleeve member 18 of the bushing body 12. The outer sleeve 50 is formed into a generally cylindrical shape and is installed in an inserted state on the bottom walls 28, 28 of the outer sleeve member 18. The axial length dimension of the outer sleeve 50 is larger than that of the outer sleeve member 18. In this embodiment, it is larger than the distance between the axial outer surfaces of a pair of fastening members 14, 14 disposed on the two axial outer sides of the bushing body 12.

[0096] The two axial ends of the outer sleeve 50 are formed as reduced-diameter portions 52, 52, serving as anti-detachment parts. The reduced-diameter portion 52 is formed into a conical shape that slopes inward toward the outer axial direction. The minimum inner diameter of the reduced-diameter portion 52 is smaller than the outer diameter of the outer sleeve member 18 and the outer diameter of the fastening member 14. Furthermore, the outer sleeve member 18 abuts against the reduced-diameter portion 52 via the fastening member 14, thereby preventing the bushing 10 from falling off the outer sleeve 50.

[0097] The outer sleeve 50 is fixedly mounted to the other vibration damping connection target sleeve in the suspension mechanism, namely the arm collar 54 of the connecting rod arm, for example by pressing or other methods. Thus, the outer sleeve member 18 is mounted to the other vibration damping connection target member (connecting rod arm) via the outer sleeve 50, and the outer sleeve 50 and the arm collar 54 constitute the mounting sleeve of this embodiment.

[0098] The outer cylinder member 18 is installed in the outer sleeve 50 in an inserted state that allows it to slide axially. That is, the outer peripheral surface of the outer cylinder member 18 coincides with the inner peripheral surface of the outer sleeve 50 in a pressed state, and frictional resistance acts between the outer cylinder member 18 and the outer sleeve 50. Moreover, if the axial force acting on the outer cylinder member 18 exceeds the frictional resistance acting between the outer peripheral surface of the outer cylinder member 18 and the inner peripheral surface of the outer sleeve 50, the outer cylinder member 18 will be displaced axially relative to the outer sleeve 50.

[0099] If the outer cylinder component 18 slides relative to the outer sleeve 50, then as Figure 6 As shown, even if the relative axial displacement between the inner shaft member 16 and the outer sleeve 50 increases, the spring characteristics of the bushing 10 can be prevented from becoming stiff. That is, as indicated by the spring characteristics of the bushing 10... Figure 6 As shown in (a) to (c), before the outer cylinder member 18 slides relative to the outer sleeve 50, the spring of the bushing 10 stiffens as the relative axial displacement between the inner shaft member 16 and the outer sleeve 50 increases. On the other hand, when the outer cylinder member 18 begins to slide relative to the outer sleeve 50, the increase in load corresponding to the increase in the relative axial displacement between the inner shaft member 16 and the outer sleeve 50 can be reduced or avoided, thereby preventing the spring of the bushing 10 from stiffening. Furthermore, Figure 6 The (d) shown by the double-dotted line is the spring characteristic when the outer cylinder member 18 and the outer sleeve 50 are fixed and do not slip.

[0100] Thus, according to this embodiment, the bushing 10 does not slip relative to the outer sleeve 50 in areas with low input load, exhibiting high-dynamic-spring characteristics. On the other hand, it slips relative to the outer sleeve 50 in areas with high input load, exhibiting low-dynamic-spring characteristics. Therefore, for example, if the bushing 10 is applied to a suspension mechanism, excellent handling stability due to high-dynamic-spring characteristics is achieved in the initial stage of low input load, and good ride comfort is achieved through vibration insulation and other effects due to low-dynamic-spring characteristics when the load increases.

[0101] Here, the axial spring characteristics of the bushing 10 can be adjusted by setting the amount of compression deformation of each adjusting elastomer 38 through a pair of fastening members 14, 14.

[0102] That is, when using bolt member 46 and nut 48 to bring a pair of fastening members 14, 14 close together and press them against inner cylinder member 24, such as Figure 1 As shown, a pair of fastening members 14, 14 are pressed against the adjusting elastic bodies 38 of the bushing body 12, and the adjusting elastic bodies 38 are compressed axially between the side wall 30 of the outer cylinder member 18 and the fastening members 14.

[0103] As the axial compression deformation of the adjusting elastic body 38 caused by the contact of the fastening member 14 increases, the axial spring stiffens. Therefore, by appropriately adjusting the amount of compression deformation of the adjusting elastic body 38 caused by the contact of the fastening member 14, the axial spring characteristics of the adjusting elastic body 38 can be adjusted, thereby adjusting the axial spring characteristics of the bushing 10.

[0104] Furthermore, when the adjusting elastomer 38 is compressed axially, it deforms in a manner that bulges outwards. This deformation is transmitted via the connecting rubber 40 to the integrally formed main body rubber elastomer 20, causing the main body rubber elastomer 20 to deform outwards. Since the main body rubber elastomer 20 is disposed on the inner circumference of the outer cylinder member 18, the outer cylinder member 18 is pressed outwards as the main body rubber elastomer 20 deforms.

[0105] In this embodiment, the inward bulging deformation of the main rubber elastomer 20 is limited by the cylindrical fixing member 22, thus enabling more efficient outward bulging deformation of the main rubber elastomer 20. Furthermore, since the main rubber elastomer 20 is disposed in a filled state within the inner circumference of the groove-shaped outer cylinder member 18, the large diameter of the bushing 10 can be suppressed, and a larger rubber volume of the main rubber elastomer 20 can be ensured within the inner circumference of the outer cylinder member 18, thereby efficiently achieving the effect of the main rubber elastomer 20 pressing the outer cylinder member 18 towards the outer circumference.

[0106] Since the outer cylinder component 18 is composed of a pair of mutually separated outer structural metal parts 26, 26, when the main rubber elastomer 20 fixedly mounted on the inner circumferential surface of the outer cylinder component 18 is to deform outward, the forces acting on the upper and lower outer sides act on these outer structural metal parts 26, 26, causing them to displace in a mutually separating manner. As a result, the outer surfaces of the bottom walls 28, 28 of the outer structural metal parts 26, 26 constituting the outer circumferential surface of the outer cylinder component 18 are pressed more forcefully relative to the inner circumferential surface of the outer sleeve 50. Therefore, by adjusting the amount of compression deformation of the adjusting elastomer 38 caused by the pressing force of the pair of fastening members 14, 14, the radial contact pressure of the outer cylinder component 18 relative to the outer sleeve 50 can be adjusted. If the radial contact pressure between the outer cylinder component 18 and the outer sleeve 50 is adjusted in this way, the axial sliding resistance between the outer circumferential surface of the outer cylinder component 18 and the inner circumferential surface of the outer sleeve 50 can be adjusted.

[0107] By adjusting the frictional resistance between the mating surfaces of the outer cylinder member 18 and the outer sleeve 50, the threshold load at which the outer cylinder member 18 begins to slide relative to the outer sleeve 50 can be adjusted. Therefore, by adjusting the axial compression deformation of each adjusting elastomer 38 generated by the pair of fastening members 14, 14, the threshold load at which the outer cylinder member 18 begins to slide relative to the outer sleeve 50 can be set.

[0108] For example, Figure 6 Figures (a) to (c) show the changes in spring characteristics under different conditions of compressive deformation of the adjusting elastic body 38 in bushing 10. More specifically, (a) represents the case with the minimum compressive deformation of the adjusting elastic body 38, (c) represents the case with the maximum compressive deformation of the adjusting elastic body 38, and (b) represents the case where the compressive deformation of the adjusting elastic body 38 is greater than that in (a) but less than that in (c). Figure 6 As the compressive deformation of the adjusting elastomer 38 increases, the load thresholds (A, B, C on the vertical axis) at which sliding begins also increase. This can be interpreted as follows: as the compressive deformation of the adjusting elastomer 38 increases, the frictional resistance acting between the outer cylinder member 18 and the outer sleeve 50 increases, and the sliding of the outer cylinder member 18 relative to the outer sleeve 50 will not generate a larger load input. Therefore, by adjusting the compressive deformation of the adjusting elastomer 38, the load thresholds at which the outer cylinder member 18 begins to slide relative to the outer sleeve 50 can be set with high precision and simplicity according to the required performance.

[0109] The amount of compression deformation of the adjustable elastic body 38 can be set with high precision and simplicity according to the length of the inner cylinder member 24 disposed between the axially opposing surfaces of the pair of fastening members 14, 14. That is, if the length of the inner cylinder member 24 is increased, the amount of compression deformation of the adjustable elastic body 38 decreases, and if the length of the inner cylinder member 24 is decreased, the amount of compression deformation of the adjustable elastic body 38 increases. Therefore, for example, by preparing a variety of inner cylinder members 24 with different lengths and selecting an inner cylinder member 24 of a length corresponding to the required characteristics from these various inner cylinder members 24, it is possible to make the parts other than the inner cylinder member 24 a common structure, and to obtain a variety of bushings 10 with different spring characteristics.

[0110] exist Figure 7 In this paper, a second embodiment of the cylindrical vibration damping device of the present invention is shown, namely a bushing 60 for motor vehicles. The bushing 60 includes a bushing body 62 and a pair of fastening members 64, 64. In the following description, the same reference numerals are used in the drawings for components and parts that are substantially the same as those in the first embodiment, and thus the description is omitted.

[0111] The bushing body 62 has a structure in which the inner shaft member 66 and the outer cylinder member 18 are elastically connected by the main rubber elastomer 20. The inner shaft member 66 is formed into a generally cylindrical shape with thick walls and a small diameter, and the inner circumferential portion 32 of the main rubber elastomer 20 is fixedly mounted on its outer circumferential surface. The inner shaft member 66 is installed on the bolt member 46 in an inserted state. The bushing body 62 of this embodiment is an integrally vulcanized molded product having the inner shaft member 66 and the outer cylinder member 18 and the main rubber elastomer 20.

[0112] A pair of fastening members 64, 64 are arranged on both sides of the inner shaft member 66 along its axial direction. The fastening member 64 is a ring-shaped member, and has an inner abutment portion 68 at its inner peripheral end that protrudes axially inward as a positioning portion. In this embodiment, the fastening member 64 is formed by bending its inner peripheral end along the axial direction to extend circumferentially with an L-shaped cross-section, and the inner abutment portion 68, which serves as the positioning portion, is integrally formed with the elastic body abutment portion 44. The fastening member 64 is, for example, a stamped metal part obtained by stamping a metal blank.

[0113] A pair of fastening members 64, 64 are pressed against the axial end faces of the inner shaft member 66 by having their inner abutment portions 68, 68 in an abutment state. They are then fastened by bolt members 46 and nuts 48. This sets the axial distance between the opposing surfaces of the elastic abutment portions 44, 44 in the pair of fastening members 64, 64. In this embodiment, the inner shaft member 66 constitutes the defining member, and the inner abutment portions 68, 68 constitute the positioning portion. The elastic abutment portion 44 of the fastening member 64 is pressed against the adjusting elastic body 38, which is compressed by being sandwiched between the side wall 30 of the outer cylinder member 18 and the outer peripheral end of the fastening member 64 axially.

[0114] The axial compressive deformation of the adjusting elastic body 38 based on a pair of fastening members 64, 64 can be adjusted not only by the axial length dimension of the inner shaft member 66, which is a specified member, but also by the axial length dimension of the inner abutment portion 68 of the fastening member 64. Therefore, in this embodiment, by adjusting the axial length dimension of the inner abutment portion 68, the axial compressive deformation of the adjusting elastic body 38 can be adjusted without changing the axial length dimension of the inner shaft member 66.

[0115] In this embodiment, by adjusting the axial length of the inner abutment portion 68 in the fastening member 64, the abutment surface of the inner shaft member 66 (i.e., the protruding front end surface of the inner abutment portion 68) and the abutment surface of the adjusting elastic body 38 in the elastic body abutment portion 44 are positioned differently in the axial direction. This allows for adjusting the load threshold at which the outer cylinder member 18 begins to slide relative to the outer sleeve 50 while simultaneously using the bushing body 62 containing the inner shaft member 66 as a common structure and adjusting the amount of compression deformation of the adjusting elastic body 38. For example, by preparing various fastening members 64 with different axial lengths of the inner abutment portion 68 and appropriately selecting a fastening member 64 that corresponds to the required spring characteristics, the sliding of the outer cylinder member 18 relative to the outer sleeve 50 can be controlled.

[0116] The embodiments of the present invention have been described in detail above, but the present invention is not limited thereto, although it has been described through its specific description. For example, regarding the cross-sectional shape of the outer cylinder member, the groove shape shown in the above embodiment is preferred for effectively acting the force in the outward peripheral direction generated by the fastening of the adjusting elastomer 38, but shapes other than a rectangular cross-section groove shape may also be used.

[0117] In the bushing body 12 of the above embodiment, the outer cylinder member 18 is composed of mutually independent outer structural metal parts 26, 26 extending circumferentially with a length of less than half a circumference, and is formed with slits 36, 36 formed on both radial sides of the main rubber elastomer 20. However, for example, it is also possible to use... Figure 8 , Figure 9 The structure is as shown in the integrated vulcanized molded article 70. That is, the integrated vulcanized molded article 70 is a C-shaped component formed by dividing a portion of the outer cylinder member 72 in the circumferential direction, and a cutout 36 is provided on the main body rubber elastomer 74 at a position corresponding to the divided portion of the outer cylinder member 72. The integrated vulcanized molded article 70 with such a structure deforms the outer cylinder member 72 by adjusting the axial compression of the elastomer 38, thereby opening the cut portion. Therefore, if the integrated vulcanized molded article 70 of this technical solution is used instead of the bushing body 12 of the first embodiment described above, the load threshold at which the outer cylinder member 72 begins to slide relative to the outer sleeve 50 can be adjusted by adjusting the axial compression deformation of the elastomer 38, thereby obtaining the same effect as the above embodiment. In this way, the outer cylinder member only needs to be divided in at least a portion in the circumferential direction to allow for expansion-shaped deformation, and the number of divided portions can be one or more.

[0118] The adjusting elastomer is not limited to a structure disposed on the axial outer surface of the outer cylinder member as described in the above embodiments. Specifically, for example, Figure 10The outer cylinder member 82 of the bushing 80 shown does not have the side walls 30, 30 as in the above embodiment. It is integrally formed into a generally cylindrical shape with a circumferentially truncated portion and is fixedly installed on the outer peripheral surface of the main rubber elastomer 84. The main rubber elastomer 84 has adjusting elastomers 38 on both axial sides, and the adjusting elastomers 38 protrude to a position further outward in the axial direction than the outer cylinder member 82. In this embodiment, the main rubber elastomer 84 and the adjusting elastomers 38 are not separated by the side walls 30 as in the above embodiment. The outer peripheral portion 34 of the main rubber elastomer 84 and the adjusting elastomers 38 are integrally formed continuously in the axial direction. Furthermore, the adjusting elastomers 38 and the main rubber elastomer 84 are compressed axially by a pair of fastening members 14, 14, thereby deforming the outer cylinder member 82 outward in an expanded diameter shape, adjusting the contact pressure of the outer cylinder member 82 against the outer sleeve 50.

[0119] The main rubber elastomer does not necessarily need to be fixedly installed on the inner shaft member. For example, the inner circumferential surface of the main rubber elastomer can coincide with the inner shaft member in a non-fixed installation manner. In this case, the inner shaft member does not necessarily need to be provided with the fixed installation member 22 and the inner cylinder member 24 as shown in the above embodiment. For example, the inner shaft member can also be constituted by the bolt member 46. In addition, the main rubber elastomer can be separated from the inner shaft member when the fastening member 14 is not pressed against the adjusting elastomer 38. In this case, by pressing the fastening member 14 against the adjusting elastomer 38, the main rubber elastomer deforms in a radially expanding manner, and the inner circumferential surface of the main rubber elastomer abuts against the inner shaft member, thereby ensuring the force acting on the outer cylinder member 18 towards the outer periphery from the main rubber elastomer.

[0120] For example, by making the axial dimensions of the positioning portion 42 of the fastening member 14 that coincides with the inner cylinder member 24 and the axial dimensions of the elastic body abutment portion 44 of the fastening member 14 that presses against the adjusting elastic body 38 different from each other, the amount of compression of the adjusting elastic body 38 by the fastening member 14 can be adjusted without changing the length of the inner cylinder member 24. To make the axial dimensions of the positioning portion 42 and the elastic body abutment portion 44 different from each other, for example, the axially protruding inner abutment portion 68 as described in the second embodiment can be used as the positioning portion. Furthermore, by making the positioning portion 42 of the fastening member 14 that coincides with the inner cylinder member 24 thinner or thicker, and / or by making the elastic body abutment portion 44 of the fastening member 14 that presses against the adjusting elastic body 38 thicker or thinner, the difference in axial dimensions between the positioning portion 42 and the elastic body abutment portion 44 can also be achieved. For example, by locally providing separate thick-walled members relative to a ring-shaped member with a constant thickness, it is also possible to locally thicken the fastening member in at least one of the positioning portion 42 and the elastic body abutment portion 44. It should be noted that in Figure 11 The example shown is a bushing 90 with a thin-walled fastening member 92 having a positioning part 42.

[0121] The fastening member 14 can also be integrally provided on the inner shaft member 16. Specifically, for example, one fastening member 14 can be integrally provided on the head of the bolt member 46, and the other fastening member 14 can be integrally provided on the nut 48. Thus, by adjusting the amount of screwing of the nut 48 relative to the bolt member 46, the amount of compression deformation of the elastic body 38 can be adjusted.

[0122] In the second embodiment described above, the inner abutment portion 68 of one fastening member 14 may protrude more axially than the inner abutment portion 68 of the other fastening member 14, so that the inner abutment portion 68 of one fastening member 14 coincides with the inner circumferential surface of the main rubber elastomer 20 to form an inner shaft member. In this case, the axial distance between the elastomer abutment portions 44, 44 of the fastening members 14, 14 can be set by axially abutting the inner abutment portions 68 of one fastening member 14 and the inner abutment portions 68 of the other fastening member 14, 14, thereby setting and adjusting the amount of compression deformation of the elastomer 38.

[0123] The pair of fastening members are not limited to being substantially identical (symmetrical) to each other as described in the above embodiments; they can also be different from each other. Examples of such a pair of different fastening members include those with different axial dimensions of the inner abutment portion, different thickness dimensions, different outer diameter dimensions, and different shapes when viewed axially. Furthermore, it is also possible to consider a case where one fastening member is integrally formed with the inner shaft member, while the other fastening member is separate from the inner shaft member.

[0124] In the above embodiments, an example is shown where the mounting cylinder is composed of an outer sleeve 50, which is a cylindrical body, and an arm ring 54, which is a vibration-damping connection target cylinder. However, the mounting cylinder may also be composed solely of the vibration-damping connection target cylinder. In short, the outer cylinder member of the cylindrical vibration-damping device according to the present invention can be directly inserted into the vibration-damping connection target cylinder, thereby being mounted to the vibration-damping connection target cylinder in a slidable manner without passing through the cylindrical body.

[0125] It should be noted that the specific structure of the mounting cylinder and the like can be appropriately designed according to the application location of the cylindrical vibration damping device. The cylindrical vibration damping device involved in this invention only requires a mechanism that can adjust the axial connection characteristics using a pair of fastening members. For example, in the case where the mounting cylinder is constructed using vibration damping connection members as described in the above embodiment, the cylindrical vibration damping device of this invention can also be identified as having a form without a mounting cylinder. Furthermore, as long as the axial connection characteristics are adjusted, set, or tuned using a pair of fastening members, it is not limited to the above embodiment illustrating its application to suspension bushings; this invention can be applied to various cylindrical vibration damping devices. For example, as a cylindrical vibration damping device requiring axial connection characteristics, in addition to suspension bushings as exemplified, specific examples include vibration damping devices for structures as described in Japanese Patent Application Publication No. 2016-061364, and body reinforcement devices as described in Japanese Patent Application Publication No. 2016-084066. The cylindrical vibration damping device of the present invention can also be applied when the body bracket, differential bracket, engine bracket, etc. are designed to input loads and vibrations not only in the axial direction but also in the direction perpendicular to the axis.

[0126] In the above embodiment, the anti-detachment part is formed by the reduced diameter portion 52 of the outer sleeve 50, but the structure of the anti-detachment part is not limited. Specifically, for example, for the portion of the bolt member 46 that extends axially outward beyond the outer sleeve 50, a stop portion that protrudes outward and has a diameter larger than that of the outer sleeve 50 is provided. By the axial contact between this stop portion and the outer sleeve 50, it is also possible to prevent the bushing 10 from moving axially to one side relative to the outer sleeve 50 (equivalent to...). Figure 1 (The right side) may detach. In this case, the reduced diameter portion 52 on the axial side may be omitted, and the anti-detachment portion on the axial side may be composed of a stop portion.

Claims

1. A cylindrical vibration isolator (10, 60) in which an inner shaft member (16, 66) and an outer cylinder member (18, 72, 82) are joined by a main rubber elastic body (20, 74, 84), the outer cylinder member (18, 72, 82) is installed in an inner insertion state capable of sliding in an axial direction with respect to a mounting cylinder portion (50), characterized in that at least a portion of the outer cylinder member (18, 72, 82) is divided in a circumferential direction and is capable of deforming or displacing in a radial direction, a pair of fastening members (14, 64, 92) are disposed on both axial sides of the main rubber elastic body (20, 74, 84), the main rubber elastic body (20, 74, 84) is fixedly installed on an inner peripheral surface of the outer cylinder member (18, 72, 82), and an adjustment elastic body (38) that presses the pair of fastening members (14, 64, 92) on both axial sides is integrally formed with the main rubber elastic body (20, 74, 84), a sliding resistance in the axial direction between an outer peripheral surface of the outer cylinder member (18, 72, 82) and an inner peripheral surface of the mounting cylinder portion (50) is capable of being set according to a pressing force of the pair of fastening members (14, 64, 92) on the adjustment elastic body (38), the fastening members (14, 64, 92) are formed in a ring plate shape, a positioning portion (42, 68) that is positioned in the axial direction with respect to the inner shaft member (16, 66) is provided on an inner peripheral portion of the fastening members (14, 64, 92), and the pair of fastening members (14, 64, 92) are pressed against both axial end surfaces of the inner shaft member (66) by abutting the positioning portions (42, 68) against the both axial end surfaces of the inner shaft member (66).

2. The cylindrical vibration isolator (10, 60) according to claim 1, characterized in that the fastening members (14, 64, 92) are opposed in the axial direction with respect to the outer cylinder member (18, 72), the adjustment elastic body (38) is disposed on an axial opposite surface of each of the fastening members (14, 64, 92) in the outer cylinder member (18, 72), and the main rubber elastic body (20, 74) and the adjustment elastic body (38) are integrally connected and integrally molded by a connecting rubber (40) on an inner peripheral surface of the outer cylinder member (18, 72).

3. The cylindrical vibration isolator (10, 60) according to claim 2, characterized in that the outer cylinder member (18, 72) is formed in a groove-shaped cross section that is open toward an inner peripheral surface, the outer cylinder member (18, 72) has a peripheral wall portion (28) that extends in the axial direction and a pair of receiving portions (30) that protrude toward the inner peripheral surface from both axial end portions of the peripheral wall portion (28), the adjustment elastic body (38) is fixedly installed on an axial outer surface of each of the pair of receiving portions (30), and an inner side of the outer cylinder member (18, 72) surrounded by the peripheral wall portion (28) and the pair of receiving portions (30) is filled with the main rubber elastic body (20, 74). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4. The cylindrical vibration isolator (10, 60) according to claim 1, characterized in that the inner shaft member (16, 66) is provided with a prescribed member disposed between the axially opposite faces of the pair of fastening members (14, 64, 92) and prescribing the distance between the axially opposite faces of the pair of fastening members (14, 64, 92), the abutting portions of the pair of fastening members (14, 64, 92) that abut against the prescribed member are the positioning portions (42, 68).

5. The cylindrical vibration isolator (60) according to claim 1, characterized in that the positioning portions (42, 68) of the fastening members (64, 92) are constituted by inner abutting portions that abut against the inner shaft member (66) from the outer side in the axial direction, an elastic body abutting portion (44) that abuts against the adjustment elastic body (38) from the outer side in the axial direction is provided at the outer peripheral portion of the fastening member (64, 92), the abutting faces of the inner abutting portions of the fastening members (64, 92) that abut against the inner shaft member (66) and the abutting faces of the elastic body abutting portions (44) that abut against the adjustment elastic body (38) are different in position in the axial direction.

6. The cylindrical vibration isolator (10, 60) according to any one of claims 1 to 3, characterized in that the cylindrical vibration isolator (10, 60) has a cylindrical body that is fixedly fitted to a vibration-isolation-connection-object member to constitute the mounting cylinder portion (50), the outer cylinder member (18, 72, 82) is mounted in an inner-inserted state capable of sliding in the axial direction to the cylindrical body, and the cylindrical vibration isolator (10, 60) is provided with a detachment-preventing portion (52) that limits the amount of movement resulting from the sliding in the axial direction of the outer cylinder member (18, 72, 82) relative to the cylindrical body.

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