Cylindrical vibration isolation device

Abstract

To provide a cylindrical vibration isolator having a novel structure which can accurately regulate the axial positions of a vibration isolator body and a collar member during their assembly while having a rubber-coated layer interposed between the vibration isolator body and the collar member.SOLUTION: A cylindrical vibration isolator 10 includes a vibration isolator body 12 pressure-inserted and fixed to an assembling hole 52 in a collar member 14 and assembled thereto, the vibration isolator body 12 being composed of an integral vulcanized molding in which an inner shaft member 16 is connected with an outer cylinder member 18 by a body rubber elastic body 20. A rubber-coated layer 34 is formed on an external peripheral surface of the outer cylinder member 18 of the vibration isolator body 12, while an open part 58 located on the external peripheral surface of the outer cylinder member 18 is provided in the collar member 14. The rubber-coated layer 34 on the outer cylinder member 18 spans from a region which is covered with the collar member 14 through to the open part 58. The collar member 14 is fixed to the outer cylinder member 18 such that the collar member 14 is locked to the rubber-coated layer 34 at an end edge part 59 of the release part 58.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a cylindrical vibration isolator applied to automobile engine mounts, motor mounts, subframe mounts, suspension bushes and the like. [Background Art]

[0002] Conventionally, cylindrical vibration isolators applied to automobile engine mounts, motor mounts, subframe mounts, suspension bushes and the like have been known. As disclosed in, for example, Japanese Patent Laid-Open No. 2015-161356 (Patent Document 1), the cylindrical vibration isolator has a vibration isolator main body in which an inner shaft member and an outer cylindrical member are connected by a main rubber elastic body, and has a structure in which the vibration isolator main body is press-fitted and fixed into an assembly hole of a collar member. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Laid-Open No. 2015-161356 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Incidentally, in the cylindrical vibration isolator of Patent Document 1, a covering rubber layer is formed on the outer peripheral surface of the outer cylindrical member, and the vibration isolator main body is fixed to the collar member in a rubber press-fitted state where the covering rubber layer is interposed between the outer cylindrical member and the collar member in the radial direction. This allows adjustment of press-fitting force and avoidance of damage during press-fitting, compared to the case where the outer cylindrical member is press-fitted and fixed so as to directly overlap the collar member.

[0005] However, when attempting to fix the vibration isolator main body and the collar member to each other in a rubber press-fitted state, there has been a risk that the vibration isolator main body is displaced in the pull-out direction relative to the collar member due to the elastic restoring force (springback) of the covering rubber layer crushed between the outer cylindrical member and the collar member.

[0006] The problem to be solved by the present invention is to provide a cylindrical vibration damping device with a novel structure that allows for precise definition of the axial position of the vibration damping device body and the collar member during assembly, while interposing a covering rubber layer between the vibration damping device body and the collar member. [Means for solving the problem]

[0007] The following describes preferred embodiments for understanding the present invention. However, each embodiment described below is illustrative and can be combined with others as appropriate. Furthermore, the multiple components described in each embodiment can be recognized and adopted as independently as possible, and can be combined with any component described in another embodiment as appropriate. Thus, the present invention is not limited to the embodiments described below, and various other embodiments can be realized.

[0008] The first embodiment is a cylindrical vibration damping device in which the vibration damping device body, which is made of an integrally vulcanized molded product in which an inner shaft member and an outer cylindrical member are connected by a main rubber elastic body, is assembled by press-fitting and fixing into the assembly hole of a collar member, wherein a covering rubber layer is formed on the outer circumferential surface of the outer cylindrical member in the vibration damping device body, while the collar member is provided with an opening located on the outer circumferential surface of the outer cylindrical member, and the covering rubber layer on the outer cylindrical member extends from the area covered by the collar member to the opening, and the collar member is fixed to the outer cylindrical member in a state of locking to the covering rubber layer at the edge of the opening.

[0009] In the cylindrical vibration isolation device constructed according to this embodiment, the outer cylindrical member is press-fitted and fixed to the collar member with the edge of the open portion of the collar member locked in the axial direction to the covering rubber layer fixed to the outer circumferential surface of the outer cylindrical member. Therefore, resistance to the outer cylindrical member coming out of the collar member (pull-out resistance) is also exerted by the locking between the edge of the open portion of the collar member and the covering rubber layer.

[0010] Since the covering rubber layer is provided on the outer circumferential surface of the outer cylindrical member not only in the open portion of the collar member but also in the area covered by the collar member, when the outer cylindrical member is press-fitted into the collar member, the covering rubber layer between the outer cylindrical member and the collar member is pushed out towards the open portion, thereby ensuring a large locking area with respect to the edge of the open portion of the collar member.

[0011] The second embodiment is a cylindrical vibration damping device as described in the first embodiment, wherein an outer flange-like portion is provided at the axial end of the outer cylindrical member, and the axial inner surface of the outer flange-like portion directly contacts and overlaps with the open end surface of the assembly hole in the collar member.

[0012] In the cylindrical vibration isolation device constructed according to this embodiment, the position of the press-fit end of the outer cylindrical member with respect to the collar member is determined by the contact between the outer flange-like portion of the outer cylindrical member and the open end face of the assembly hole in the collar member. In particular, since the outer flange-like portion of the outer cylindrical member and the open end face of the assembly hole in the collar member are in direct contact without the use of easily deformable materials such as rubber, the press-fit end of the outer cylindrical member with respect to the collar member can be precisely defined.

[0013] A third embodiment is a cylindrical vibration damping device described in the first or second embodiment, wherein an outer flange-like portion is provided at the axial end of the outer cylindrical member, and a partially notched portion is formed in the circumferential direction of the outer flange-like portion, and the main rubber elastic body and the covering rubber layer are integrally formed by filling the notched portion with rubber.

[0014] According to the cylindrical vibration isolation device with a structure conforming to this embodiment, the structure can be simplified and the number of rubber vulcanization molding steps can be reduced by integrally forming the covering rubber layer with the main rubber elastic body.

[0015] By using the filler rubber provided in the notched portion formed in the outer flange-like portion to integrally connect the main rubber elastic body and the covering rubber layer, it becomes easier to ensure the fluidity of the rubber material during molding between the inner circumferential main rubber elastic body and the outer circumferential covering rubber layer, compared to, for example, the case where the main rubber elastic body and the covering rubber layer are integrally connected so as to wrap around the outer flange-like portion. Therefore, even if the covering rubber layer is thinner than the main rubber elastic body, it becomes easier to prevent molding defects in the covering rubber layer and to form a proper covering rubber layer.

[0016] Furthermore, the outer flange-like portion can be exposed on both axial sides without being covered with rubber, and for example, the press-fit end of the outer cylindrical member into the collar member can be precisely defined by direct axial contact between the outer flange-like portion and the collar member.

[0017] The fourth embodiment is a cylindrical vibration damping device as described in the third embodiment, wherein a plurality of the notched portions having the filling rubber are provided in the circumferential direction of the outer cylindrical member.

[0018] According to the cylindrical vibration damping device constructed in accordance with this embodiment, filling rubber that connects the main rubber elastic body and the covering rubber layer is provided at multiple locations in the circumferential direction. For example, when the rubber material injected into the cavity of the main rubber elastic body is filled into the cavity of the covering rubber layer via the cavity of the filling rubber, the rubber material flows into the cavity of the covering rubber layer at multiple locations in the circumferential direction, making it less likely for molding defects in the covering rubber layer to occur.

[0019] The fifth embodiment is a cylindrical vibration damping device described in any one of the first to fourth embodiments, wherein the covering rubber layer is provided with a protruding portion that extends outward, and the edge of the open portion of the collar member is locked to the protruding portion of the covering rubber layer in at least a portion of the case.

[0020] According to the cylindrical vibration damping device having the structure according to the present embodiment, since the protruding portion protruding outward in the radial direction is formed in advance on the covering rubber layer, the collar member is easily locked to the covering rubber layer at the edge portion of the opening portion with a larger area. In addition, since the locking between the collar member and the covering rubber layer is achieved by the protruding portion without greatly deforming the covering rubber layer, damage caused by excessive deformation of the covering rubber layer can be easily avoided.

[0021] In a sixth aspect, in the cylindrical vibration damping device according to the fifth aspect, the protruding portion of the covering rubber layer extends in the circumferential direction, a plurality of the protruding portions are provided spaced apart from each other in the axial direction of the outer cylindrical member, and an edge portion of the opening of the collar member is locked to any one of the plurality of protruding portions.

[0022] According to the cylindrical vibration damping device having the structure according to the present embodiment, by locking the protruding portion extending in the circumferential direction with the edge portion of the opening in the collar member, a larger locking area can be secured, and falling out of the outer cylindrical member from the collar member can be more effectively prevented.

[0023] Since the plurality of protruding portions are provided spaced apart from each other in the axial direction, it is also possible to attach the vibration damping device main body of a common structure to a plurality of types of collar members having different axial positions of the edge portions of the opening portions.

[0024] In a seventh aspect, in the cylindrical vibration damping device according to any one of the first to sixth aspects, an axial dimension of the collar member is smaller than an axial dimension of the outer cylindrical member in at least a part of the circumferential direction, and the opening portion is provided axially outward of the collar member.

[0025] According to the cylindrical vibration damping device having the structure according to the present embodiment, by adjusting the axial dimensions of the outer cylindrical member and the collar member, the collar member having a simple structure such as a simple cylindrical shape can be locked to the covering rubber layer, for example, and falling out of the outer cylindrical member from the collar member can be prevented.

[0026] In an eighth aspect, in the cylindrical vibration isolator according to any one of the first to seventh aspects, the collar member is formed with a window portion penetrating in the radial direction, and the opening portion of the collar member is constituted by the window portion.

[0027] According to the cylindrical vibration isolator structured according to this aspect, by forming the window portion at an appropriate position of the collar member, locking between the collar member and the covering rubber layer can be achieved regardless of the axial length of the collar member.

[0028] In a ninth aspect, in the cylindrical vibration isolator according to any one of the first to eighth aspects, an inner peripheral corner portion of an edge of the opening portion in the collar member is formed into a chamfered shape having an inclined end surface that gradually increases in diameter toward the opening portion side.

[0029] According to the cylindrical vibration isolator structured according to this aspect, the compression reaction force of the covering rubber layer compressed between the outer cylinder member and the collar member acts on the inclined end surface of the collar member, whereby a component force of the compression reaction force of the covering rubber layer is exerted in a direction preventing the outer cylinder member from coming off the collar member, so that positioning and holding of the outer cylinder member and the collar member in the axial direction can be achieved more advantageously. Effects of the Invention

[0030] According to the present invention, in a cylindrical vibration isolator, while a covering rubber layer is interposed between the vibration isolator main body and the collar member, the axial position during assembly of the vibration isolator main body and the collar member can be accurately defined. Brief Description of the Drawings

[0031] [Figure 1] Perspective view showing a cylindrical vibration isolator as a first embodiment of the present invention [Figure 2] Front view of the cylindrical vibration isolator shown in Fig. 1 [Figure 3] III-III cross-sectional view of Fig. 2 [Figure 4] Right side view of the vibration isolator main body constituting the cylindrical vibration isolator shown in Fig. 1 [Figure 5] Bottom view of the vibration isolation device body shown in Figure 4. [Figure 6] Figure 4, section VI-VI [Figure 7] Figure 6, section VII-VII [Figure 8] Perspective view of the outer cylindrical member constituting the main body of the vibration isolation device shown in Figure 4. [Figure 9] Cross-sectional view of the outer cylindrical member shown in Figure 8. [Figure 10] Perspective view showing a cylindrical vibration damper as a second embodiment of the present invention. [Figure 11] Figure 10 is a cross-sectional view of a cylindrical vibration isolation device, and shows the cross-section corresponding to Figure 3. [Figure 12] Perspective view showing a cylindrical vibration damper as a third embodiment of the present invention. [Figure 13] Figure 12 is a cross-sectional view of a cylindrical vibration isolation device, and shows the cross-section corresponding to Figure 3. [Figure 14] Figure 13 is a cross-sectional view of the vibration isolation device body that constitutes the cylindrical vibration isolation device, and shows the cross-section corresponding to Figure 13. [Modes for carrying out the invention]

[0032] Embodiments of the present invention will be described below with reference to the drawings.

[0033] Figures 1 to 3 show a cylindrical vibration damping device 10 as a first embodiment of the present invention, which is suitably applied to, for example, engine mounts, motor mounts, subframe mounts, suspension bushings, etc., for automobiles. The cylindrical vibration damping device 10 has a structure in which the vibration damping device body 12 is press-fitted and fixed to a collar member 14. As shown in Figures 4 to 7, the vibration damping device body 12 has a structure in which an inner shaft member 16 and an outer cylindrical member 18 are connected by a main body rubber elastic body 20. In the following description, the vertical direction refers to the vertical direction in Figure 2, the left-right direction refers to the left-right direction in Figure 2, and the front-back direction refers to the left-right direction in Figure 3, which is the central axis direction.

[0034] The inner shaft member 16 is a highly rigid member formed from, for example, metal or fiber-reinforced synthetic resin, and has a thick-walled, small-diameter, substantially cylindrical shape. In this embodiment, it extends straight in the front-rear direction with a substantially constant cross-sectional shape, but the shape and size of the cross-section may change in the axial direction, for example, by providing a bulge portion with a larger diameter in the central part in the axial direction compared to the ends in the axial direction. Furthermore, the inner shaft member 16 is not limited to a cylindrical shape, but may also be in the shape of a solid rod.

[0035] The outer cylindrical member 18 is made of metal, synthetic resin, or the like, and has a substantially cylindrical shape with a thinner wall and larger diameter than the inner shaft member 16. The outer cylindrical member 18 is integrally formed with a cylindrical portion 22 extending in the front-rear direction and an outer flange-like portion 24 protruding outward from the front end of the cylindrical portion 22. As shown in Figures 4 and 7, the outer flange-like portion 24 extends continuously in the circumferential direction, and a pair of notched portions 26, 26 are partially formed in the circumferential direction on both sides in the left-right direction. The notched portions 26 are formed to penetrate the front end of the outer cylindrical member 18 from which the outer flange-like portion 24 protrudes in the left-right direction, and the axial dimension of the outer cylindrical member 18 is smaller in the portion where the notched portions 26 are formed than in other parts. Preferably, the circumferential width dimension (vertical width dimension) of the notched portions 26 is smaller than the diameter of the inner shaft member 16.

[0036] The outer cylindrical member 18 is externally positioned on the outer circumference of the inner shaft member 16, and the inner shaft member 16 and the outer cylindrical member 18 are elastically connected by the main rubber elastic body 20. The main rubber elastic body 20 has a thick, substantially cylindrical shape, with its inner circumferential surface vulcanized and bonded to the inner shaft member 16, and its outer circumferential surface vulcanized and bonded to the outer cylindrical member 18. The main rubber elastic body 20 is formed as an integrally vulcanized molded product comprising the inner shaft member 16 and the outer cylindrical member 18. In this embodiment, the main rubber elastic body 20 does not reach the axial ends of the inner shaft member 16 and the outer cylindrical member 18, and the respective axial end faces of the inner shaft member 16 and the outer cylindrical member 18 are exposed without being covered by rubber.

[0037] The main rubber elastic body 20 formed on the inner circumference of the outer cylindrical member 18 has a pair of axially penetrating holes 28, 28. The axially penetrating holes 28 are located on both the upper and lower sides of the inner shaft member 16 and penetrate the main rubber elastic body 20 in the front-to-back direction. As shown in Figure 7, the main rubber elastic body 20 has a pair of rubber arms 30, 30 that extend in the left-to-right direction between the upper and lower parts of the axially penetrating holes 28, 28.

[0038] As shown in Figures 6 and 7, a stopper rubber 32 protrudes from the outer circumference towards the inner circumference (inner shaft member 16 side) of the cut hole 28. The stopper rubber 32 is integrally formed with the main rubber elastic body 20 and protrudes inward in the vertical direction from the axial middle portion of the main rubber elastic body 20. The stopper rubber 32 is positioned opposite the inner surface of the inner circumference wall of the cut hole 28, separated by a predetermined stopper clearance in the vertical direction.

[0039] A covering rubber layer 34 is formed on the outer circumferential surface of the outer cylindrical member 18. As shown in Figures 4 and 5, the covering rubber layer 34 in this embodiment is composed of a plurality of circumferential rib-like portions 36 that protrude outward and extend in the circumferential direction, and a plurality of axial rib-like portions 38 provided between the axial directions of these circumferential rib-like portions 36.

[0040] The circumferential rib-like portion 36 extends continuously around the entire circumference of the outer cylindrical member 18 with a substantially constant cross-sectional shape. The surface of the circumferential rib-like portion 36 is composed of a front surface 40, an intermediate cylindrical surface 42, and a rear surface 44. The front surface 40 has an inner circumferential end that spreads out substantially perpendicular to the axis, and an outer circumferential end that is a curved surface that slopes backward toward the outer circumference. The intermediate cylindrical surface 42 is a substantially cylindrical surface that spreads out substantially parallel to the axial direction. The rear surface 44 is an inclined surface that slopes inward toward the rear, and its angle of inclination with respect to the axial direction is smaller than that of the front surface 40.

[0041] In this embodiment, three circumferential rib-like portions 36a, 36b, and 36c are provided spaced apart from each other in the axial direction. The front and central circumferential rib-like portions 36a and 36b have substantially the same shape, while the rear circumferential rib-like portion 36c has a slightly different shape from the other two. Specifically, the inclination angle of the rear surface 44 of the rear circumferential rib-like portion 36c changes in stages, with the inclination angle of the front portion, which is closer to the intermediate cylindrical surface 42, being smaller than the inclination angle of the rear surface 44 of the other two circumferential rib-like portions 36a and 36b, and the inclination angle of the rear portion, which is further from the intermediate cylindrical surface 42, being larger than the inclination angle of the rear surface 44 of the other two circumferential rib-like portions 36a and 36b. The axial distance between the circumferential rib-like portions 36a and 36b and the axial distance between the circumferential rib-like portions 36b and 36c are substantially the same.

[0042] In each of the circumferential rib-shaped portions 36a, 36b, and 36c, the inclination angle of the front surface 40 with respect to the axial direction is greater than the inclination angle of the rear surface 44 with respect to the axial direction. If the inclination angles of the front surface 40 and the rear surface 44 are not constant, the average value of the inclination angles can be used for comparison. In this embodiment, the maximum inclination angle of the front surface 40 of the circumferential rib-shaped portion 36c is greater than the maximum inclination angle of the rear surface 44.

[0043] The axial rib portion 38 extends linearly in the axial direction, and both its front and rear ends are integrally continuous with one of the adjacent circumferential rib portions 36, 36 in the axial direction. The projection height dimension of the axial rib portion 38 toward the outer circumference is smaller than the projection height dimension of the circumferential rib portion 36 toward the outer circumference, so that the circumferential rib portion 36 protrudes further toward the outer circumference than the axial rib portion 38. In this embodiment, multiple axial rib portions 38 are formed spaced apart from each other in the circumferential direction. As a result, in this embodiment, the covering rubber layer 34 is arranged in a grid pattern consisting of circumferential rib portions 36a, 36b, 36c and multiple axial rib portions 38, and multiple concave relief portions 46 are formed, surrounded by adjacent circumferential rib portions 36, 36 and adjacent axial rib portions 38, 38 in the axial direction.

[0044] The axial rib-shaped portion 38 located in front of the circumferential rib-shaped portion 36b in the axial center and the axial rib-shaped portion 38 located behind it are arranged in series in the axial direction, and the front axial rib-shaped portion 38 and the rear axial rib-shaped portion 38, which are arranged side by side in the axial direction, have substantially the same shape. In addition, the axial rib-shaped portion 38 located in the central part in the vertical direction is wider than the other axial rib-shaped portions 38. In this embodiment, the multiple axial rib-shaped portions 38 are shaped so as not to undercut when demolding the molding die in the left-right direction, thereby improving demolding performance. As a result, no axial rib-shaped portion 38 is formed in the central part in the left-right direction (see Figure 5).

[0045] The covering rubber layer 34 and the main rubber elastic body 20 are integrally formed by a filler rubber 48. As shown in Figure 7, the filler rubber 48 is provided by filling the notched portions 26, 26 of the outer cylindrical member 18, with its inner circumferential end integrally continuous with the main rubber elastic body 20 and its outer circumferential end integrally continuous with the covering rubber layer 34, thereby integrally connecting the main rubber elastic body 20 and the covering rubber layer 34. In this embodiment, a filler rubber 48 is provided in each of the pair of notched portions 26, 26, and the main rubber elastic body 20 and the covering rubber layer 34 are continuous at multiple locations (2 locations) in the circumferential direction by these multiple filler rubbers 48. The covering rubber layer 34 is provided with a strip-shaped connecting rubber 49 that connects the front circumferential rib-shaped portion 36 and the filler rubber 48. The connecting rubber 49 extends in the axial direction, and its circumferential width dimension is larger than that of the axial rib-shaped portion 38, thereby ensuring a large cross-sectional area. Since the main rubber elastic body 20 and the covering rubber layer 34 are integrally formed, the entire vibration isolation device body 12 is a single-piece vulcanized molded product.

[0046] In this embodiment, a gate mark 50 is formed on the front surface of the filler rubber 48. The gate mark 50 is the trace of a gate used to inject rubber material into the cavity of a molding die when molding the main rubber elastic body 20, the covering rubber layer 34, and the filler rubber 48, and the rubber material fills the cavity in the molded portion of the filler rubber 48.

[0047] The vibration isolation device body 12, which has this structure, is press-fitted and fixed to the collar member 14. As shown in Figures 8 and 9, the collar member 14 is a large-diameter, substantially cylindrical shape with an assembly hole 52 that penetrates in the axial direction, and is a highly rigid member made of metal or the like. The axial end faces of the collar member 14 are annular surfaces 54 on the outer circumference that spread out in a direction substantially perpendicular to the axis, and tapered surfaces 56 on the inner circumference that incline axially inward toward the inner circumference.

[0048] A window portion 58 is formed in the axial middle portion of the color member 14, serving as an open section. The window portion 58 has a roughly rounded rectangular cross-section and is a hole that penetrates radially. The window portion 58 is provided with a front edge portion 59 that extends in the circumferential direction. In this embodiment, the window portion 58 is formed on both the upper and lower sides and on both the left and right sides, providing four locations in the circumferential direction. In this embodiment, the window portion 58 is formed in the axial central portion, and the color member 14 has a shape that does not depend on its axial orientation.

[0049] The outer cylindrical member 18 of the vibration isolation device body 12 is press-fitted into the assembly hole 52 of the collar member 14 via a covering rubber layer 34. That is, the covering rubber layer 34 is compressed radially between the outer circumferential surface of the cylindrical portion 22 of the outer cylindrical member 18 and the inner circumferential surface of the collar member 14, and the outer cylindrical member 18 is positioned and attached to the collar member 14 in the axial direction by the friction of the compressed covering rubber layer 34. The front end surface of the collar member 14, which is the opening end of the assembly hole 52, directly abuts against and overlaps the outer flange-like portion 24 of the outer cylindrical member 18 without the use of rubber or the like, defining the press-fit end of the outer cylindrical member 18 to the collar member 14. In this embodiment, the circumferential rib-like portions 36a and 36c that protrude significantly outward in the covering rubber layer 34 are compressed throughout between the outer cylindrical member 18 and the collar member 14. The significant compression of the circumferential rib-like portions 36a and 36c ensures that the outer cylindrical member 18 and the collar member 14 are positioned with sufficient strength in the axial direction.

[0050] When the outer cylindrical member 18 is press-fitted into the collar member 14, the window portion 58 of the collar member 14 is located on the outer circumferential surface of the outer cylindrical member 18. Furthermore, the covering rubber layer 34 formed on the outer circumferential surface of the outer cylindrical member 18 extends from the area covered by the collar member 14 to the window portion 58 of the collar member 14. As shown in an enlarged view in Figure 3, the circumferential rib-like portion 36b in the axial middle of the covering rubber layer 34 fits into the window portion 58 of the collar member 14, and the collar member 14 is fixed to the outer cylindrical member 18 with the front end edge 59 of the window portion 58 axially locked to the circumferential rib-like portion 36b. As a result, the collar member 14 and the outer cylindrical member 18 are more firmly positioned in the axial direction, preventing springback of the outer cylindrical member 18 due to the elasticity of the covering rubber layer 34 and the filling rubber 48, and ensuring that the vibration damping device body 12 is mounted in the appropriate axial position relative to the collar member 14.

[0051] The circumferential rib portion 36b is deformed such that the portion located on the window portion 58 bulges outward due to radial compression between the outer cylindrical member 18 and the collar member 14 in the portion that is outside the window portion 58 in the circumferential and axial directions. As a result, the insertion amount of the circumferential rib portion 36b into the window portion 58 is increased, and the anti-dislodgement effect due to the engagement between the front end edge 59 of the window portion 58 and the circumferential rib portion 36b is more effectively exerted.

[0052] The circumferential rib-like portions 36b enter into each window portion 58 at four locations in the circumferential direction and engage with the front end edge portion 59 of each window portion 58 in the axial direction. As a result, the pull-out resistance of the outer cylindrical member 18 due to the engagement between the front end edge portion 59 of the window portion 58 and the circumferential rib-like portions 36b is exerted at each of the four locations in the circumferential direction, thereby more strongly preventing the outer cylindrical member 18 from coming out of the collar member 14. In particular, in this embodiment, since the four window portions 58, 58, 58, 58 are arranged substantially evenly in the circumferential direction, the pull-out resistance of the outer cylindrical member 18 due to the engagement between the front end edge portion 59 of each window portion 58 and the circumferential rib-like portions 36b acts in a well-balanced manner in the circumferential direction.

[0053] In this embodiment, the portion of the color member 14 that engages with the covering rubber layer 34 in the axial direction is the front end edge 59 of the window portion 58, which is set in the axial middle portion of the color member 14, rather than the axial end. This allows the color member 14 to engage with the covering rubber layer 34 in the axial direction regardless of the axial dimension of the color member 14. In this embodiment, the case in which the circumferential rib portion 36b is inserted into and locked in the window portion 58 is illustrated, but for example, depending on the axial length of the color member 14, the window portion 58 may be formed at the position where the circumferential rib portion 36a is inserted, so that the front end edge 59 of the window portion 58 engages with the circumferential rib portion 36a in the axial direction. In this way, even when the position of the window portion 58 on the color member 14 differs in the axial direction, it is possible to accommodate this with a common vibration isolation device body 12. In addition, in the color member 14, a window portion 58 can be formed at the position into which the circumferential rib portion 36c is inserted, or multiple window portions 58 can be formed at axial locations so that two or three selected from the circumferential rib portions 36a, 36b, and 36c are inserted.

[0054] Furthermore, since the front edge 59 of the window portion 58 located in the axial middle of the color member 14 engages with the covering rubber layer 34, the covering rubber layer 34 covering the outer circumferential surface of the outer cylindrical member 18 extends to both axial sides beyond the window portion 58 of the color member 14. As a result, rubber press-fitting areas are set on both axial sides of the engagement portion between the color member 14 and the covering rubber layer 34, thereby ensuring a large area for rubber press-fitting.

[0055] Figures 10 and 11 show a cylindrical vibration damping device 60 for automobiles as a second embodiment of a cylindrical vibration damping device with a structure according to the present invention. The cylindrical vibration damping device 60 has a structure in which the vibration damping device body 12 is press-fitted and fixed to a collar member 62. In the following description, components and parts that are substantially the same as those in the first embodiment will be denoted by the same reference numerals in the figures, and their descriptions will be omitted.

[0056] The collar member 62 has a large diameter and a substantially cylindrical shape, and its axial length is shorter than the cylindrical portion 22 of the outer cylindrical member 18, and in this embodiment, it is about half the length of the cylindrical portion 22. In addition, the collar member 62 does not have a window portion 58 like the collar member 14 in the first embodiment.

[0057] The collar member 62 is attached to the outer cylindrical member 18 of the vibration damping device body 12 in an external fit state via the covering rubber layer 34. The rear end edge 64 of the collar member 62 is located on the circumferential rib-shaped portion 36b of the covering rubber layer 34, with the front part of the circumferential rib-shaped portion 36b being compressed radially between the collar member 62 and the outer cylindrical member 18, and the rear part of the circumferential rib-shaped portion 36b being located behind the collar member 62 and exposed to the outside. As a result, the rear part of the circumferential rib-shaped portion 36b is overlapped in the axial direction with the rear end edge 64 of the collar member 62, and the collar member 62 is engaged in the axial direction with the circumferential rib-shaped portion 36b at the rear end edge 64. Thus, in this embodiment, the axial length dimension of the collar member 62 is smaller than that of the cylindrical portion 22 of the outer cylindrical member 18, so that the rear in the axial direction is an open portion, and the rear end edge, which is the edge of the open portion, is engaged in the axial direction with the covering rubber layer 34.

[0058] In this embodiment, the axial length of the collar member 62 is substantially constant in the circumferential direction, and the rear end edge 64 of the collar member 62 is engaged with the circumferential rib-shaped portion 36b in the axial direction over its entire circumference. This makes it possible to efficiently obtain a large amount of resistance to disengagement due to the engagement between the rear end edge 64 of the collar member 62 and the circumferential rib-shaped portion 36b. Note that the axial length of the collar member 62 may vary in the circumferential direction, and it is also possible to partially form an open portion in the circumferential direction by positioning the rear end of the collar member 62 partially forward in the circumferential direction, in which case the rear end edge of the collar member 62 is partially engaged with the circumferential rib-shaped portion 36b in the circumferential direction.

[0059] The rear end surface of the collar member 62, which constitutes the edge on the open side, has a chamfered shape at the inner circumferential corner, and the inner circumferential portion is a tapered surface 56 that gradually widens in diameter toward the open side (rear). The rear end surface of the collar member 62 is pressed against the circumferential rib-like portion 36b, at least the tapered surface 56. The circumferential rib-like portion 36b is compressed radially between the outer cylindrical member 18 and the collar member 62, and the elastic restoring force of the circumferential rib-like portion 36b acts as a pressing force toward the outer circumference of the collar member 62. This restoring force acts not only on the inner circumferential surface of the collar member 62, but also on the tapered surface 56 that widens inclined perpendicular to the axis. Furthermore, the component force of the pressing force acting on the tapered surface 56 toward the outer circumference acts as a force that pushes the collar member 62 forward in the axial direction, thereby biasing the collar member 62 to press against the outer flange-like portion 24, and positioning the outer cylindrical member 18 and the collar member 62 relative to each other at the appropriate axial position. This forward force acting on the tapered surface 56 also ensures that the outer cylindrical member 18 is held in the appropriate position relative to the collar member 62, preventing axial displacement between the outer cylindrical member 18 and the collar member 62 due to the springback of the covering rubber layer 34. In addition, the circumferential rib-like portion 36b itself receives a force that pushes it toward the rear end surface of the collar member 62 as a component force of the contact reaction force against the tapered surface 56, thereby stabilizing the securing of the rubber volume that contacts the rear end surface of the collar member 62 and improving the springback suppression effect of the collar member 62.

[0060] In this embodiment, an example is shown in which the collar member 62 engages with the circumferential rib portion 36b at its rear edge 64. However, depending on the axial length of the collar member 62, the rear edge 64 of the collar member 62 may be configured to engage with either the circumferential rib portion 36a or the circumferential rib portion 36b. Alternatively, by changing the axial position of the rear end of the collar member 62 in the circumferential direction, the rear edge 64 of the collar member 62 may be configured to engage with two or three selected circumferential rib portions 36a, 36b, and 36c. In this way, by providing multiple circumferential rib portions 36a, 36b, and 36c at mutually different positions in the axial direction, a common vibration damping device body 12 can be used to configure a retaining structure for multiple types of collar members 62 with mutually different rear end positions by engaging the rear edge 64 of the collar member 62 with the covering rubber layer 34.

[0061] Figures 12 and 13 show a third embodiment of a cylindrical vibration damper according to the present invention, which is a cylindrical vibration damper 70 for automobiles. The cylindrical vibration damper 70 has a structure in which a vibration damper body 72, which serves as the vibration damper body, is press-fitted and fixed to a collar member 74.

[0062] As shown in Figure 14, the vibration isolation device body 72 includes a covering rubber layer 76 fixed to the outer circumferential surface of the outer cylindrical member 18. The covering rubber layer 76 has three circumferential rib-like portions 36a, 36b, and 36c. In the covering rubber layer 76 of this embodiment, the front circumferential rib-like portion 36a and the middle circumferential rib-like portion 36b are substantially the same as in the first embodiment, while the rear circumferential rib-like portion 36c has a larger projection height dimension toward the outer circumferential surface. Therefore, the circumferential rib-like portion 36c faces the outer flange-like portion 24 in the axial direction on the outer circumferential side of the circumferential rib-like portions 36a and 36b.

[0063] The collar member 74 has a smaller axial length than the cylindrical portion 22 of the outer cylindrical member 18. In this embodiment, the collar member 74 has an axial length greater than half the axial length of the cylindrical portion 22, and is approximately the same as the distance between the axially opposing surfaces of the outer flange-like portion 24 and the circumferential rib-like portion 36c.

[0064] The vibration isolation device body 72 is attached to the collar member 74 by press-fitting the outer cylindrical member 18 into the collar member 74 via a covering rubber layer 76. When the vibration isolation device body 72 is attached to the collar member 74, the rear end of the collar member 74 is located behind the circumferential rib-shaped portions 36a and 36b, and the circumferential rib-shaped portions 36a and 36b are compressed radially between the outer cylindrical member 18 and the collar member 74.

[0065] The rear end surface (rear edge portion 64) of the collar member 74 is located in front of the circumferential rib portion 36c and is superimposed on the front surface 40 of the circumferential rib portion 36c in a state of contact or slight separation. The circumferential rib portion 36c, which has a large radial projection height dimension, overlaps with the collar member 74 in the axial projection. As a result, when the outer cylindrical member 18 attempts to move forward relative to the collar member 74, the engagement between the rear edge portion 64 of the collar member 74 and the circumferential rib portion 36c limits the relative forward movement of the outer cylindrical member 18 relative to the collar member 74, preventing the vibration damping device body 72 from coming off the collar member 74. In this embodiment, when the outer cylindrical member 18 is mounted on the collar member 74, the collar member 74 is located between the axially opposing surfaces of the protruding tip portion of the circumferential rib portion 36c, which is located on the outer circumference of the circumferential rib portions 36a and 36b, and the outer flange portion 24.

[0066] As shown in this embodiment, the edge of the open portion of the collar member does not necessarily have to be in a pre-engaged state pressed against the covering rubber layer. It may be positioned, for example, in close proximity in the axial direction to the covering rubber layer (circumferential rib portion) so that the outer cylindrical member can be quickly prevented from coming off the collar member by engagement.

[0067] For example, if the axial length dimension of the collar member 74 is smaller, the protruding height dimension of the circumferential rib portion 36a or 36b can be increased so that the circumferential rib portion 36a or 36b is used to prevent the collar member 74 from coming loose by engaging with it. Alternatively, the axial length dimension of the collar member 74 can be made different in the circumferential direction so that the rear end edge of the collar member 74 engages with two or three of the circumferential rib portions 36a, 36b, and 36c.

[0068] Although embodiments of the present invention have been described in detail above, the present invention is not limited by its specific description. For example, the covering rubber layer is not limited to a structure comprising circumferential rib-shaped portions 36 and axial rib-shaped portions 38 as shown in the above embodiments. Specifically, for example, it may be a cylindrical shape that covers the outer circumferential surface of the cylindrical portion 22 of the outer cylindrical member 18 with a substantially uniform thickness. When such a cylindrical covering rubber layer is adopted, the covering rubber layer can be provided with a portion that is compressed radially between the outer cylindrical member 18 and the collar member 14, and a portion that is located on the open portion of the collar member 14 and held with a thickness greater than the compressed portion, thereby allowing the open end edge of the open portion of the collar member 14 to be engaged with the covering rubber layer in the axial direction. Since the covering rubber layer is interposed in a compressed state between the outer cylindrical member 18 and the press-fitted outer fitting portion of the collar member 14, at the press-fitted outer fitting portion of the collar member 14, regardless of the shape of the covering rubber layer in the state before the collar member 14 is fitted, the covering rubber layer becomes thicker and bulges at the edge of the open portion of the collar member 14 and is locked to that edge.

[0069] In the above embodiment, a covering rubber layer having three circumferential rib-like portions was illustrated, but the circumferential rib-like portions may be one, two, or four or more. When multiple circumferential rib-like portions are formed, their shapes and sizes may differ from one another. Similarly, the number of axial rib-like portions is not particularly limited, and when multiple axial rib-like portions are provided, their shapes and sizes may differ from one another.

[0070] It is desirable that the covering rubber layer 34 is formed integrally and continuously with the main rubber elastic body 20, but it may be formed independently of the main rubber elastic body 20, or it may be made of a different material. Furthermore, in the above embodiment, a structure in which the covering rubber layer 34 and the main rubber elastic body 20 are integrally continuous via a filling rubber 48 that fills the notched portion 26 was illustrated, but the structure for integrally continuing the covering rubber layer 34 with the main rubber elastic body 20 is not particularly limited, and for example, a through hole can be formed in the cylindrical portion 22 of the outer cylindrical member 18, and the main rubber elastic body 20 and the covering rubber layer 34 can be integrally continued through the through hole. In this case, the notched portion 26 is not essential for the outer flange portion 24 of the outer cylindrical member 18, and the outer flange portion 24 can be provided continuously around its entire circumference.

[0071] In the collar member, the opening portion formed by the window portion 58 shown in the first embodiment and the opening portion provided axially rearward as shown in the second and third embodiments can be used in combination. This makes it possible to obtain a greater resistance to the outer cylindrical member 18 from the collar member.

[0072] The shape of the axial end face of the collar member is not limited to the shape having a tapered surface 56 as shown in the above embodiment, but may be, for example, an annular surface that widens in the direction perpendicular to the axis. Also, the axial end face of the collar member may be composed entirely of a tapered surface. The chamfer shape having an end face that gradually widens from the inner circumference to the outer circumference at the inner circumferential corner of the open portion of the collar member is not limited to the example C-chamfered tapered surface 56, but may be, for example, an R-chamfered curved surface. By using a curved surface, cracks in the coating rubber layer caused by pressure at the corner at the axial end of the collar member can be prevented. Furthermore, a chamfer shape similar to the tapered surface 56 can be set at the inner circumferential corner of the front edge 59 of the window portion 58 of the collar member 14 shown in the first embodiment to create an inclined end face.

[0073] The collar member is not limited to a thin-walled cylindrical member as shown in the above embodiment, nor is it limited to a cylindrical shape, as long as it has an assembly hole into which a cylindrical vibration damper is press-fitted and fixedly attached. Therefore, for example, the collar member can also be made from the mounting portion of the cylindrical vibration damper on a vehicle body side member such as a subframe. [Explanation of Symbols]

[0074] 10. Cylindrical Vibration Isolator (First Embodiment) 12 Vibration Isolator Main Unit 14 Color components 16 Inner shaft member 18 Outer cylindrical member 20 Main body rubber elastic body 22 Cylindrical part 24 Outer flange-like portion 26 Notched portion 28 slit holes 30 Rubber Arms 32 Stopper rubber 34. Covering rubber layer 36 (36a, 36b, 36c) Circumferential rib-like portion (protruding portion) 38 Axial rib-shaped section 40 front 42 Intermediate cylindrical surface 44 Rear 46 Concave relief section 48 Filling rubber 49 Connecting rubber 50 Gate marks 52 Assembly holes 54 Annular surface 56 Tapered surface 58 Window section (open section) 59 Front edge (edge ​​of the open section) 60. Cylindrical Vibration Isolator (Second Embodiment) 62 Color components 64 Rear edge (edge ​​of the open section) 70. Cylindrical Vibration Isolator (Third Embodiment) 72 Vibration Isolator Main Unit 74 Color components 76. Covering rubber layer

Claims

1. A cylindrical vibration damping device is assembled by press-fitting and fixing the main body of a vibration damping device, which is made of an integrally vulcanized molded product in which an inner shaft member and an outer cylindrical member are connected by a main rubber elastic body, into the assembly hole of a collar member. A covering rubber layer is formed on the outer circumferential surface of the outer cylindrical member in the vibration isolation device body, The aforementioned collar member is provided with an opening located on the outer circumferential surface of the outer cylindrical member, The covering rubber layer in the outer cylindrical member extends from the area covered by the color member to the open portion. A cylindrical vibration damping device in which the color member is fixed to the outer cylindrical member in a state of being locked to the covering rubber layer at the edge of the open portion.

2. The cylindrical vibration damping device according to claim 1, wherein an outer flange-like portion is provided at the axial end of the outer cylindrical member, and the axial inner surface of the outer flange-like portion directly contacts and overlaps with the open end surface of the assembly hole in the collar member.

3. The cylindrical vibration damping device according to claim 1 or 2, wherein an outer flange-like portion is provided at the axial end of the outer cylindrical member, a partially notched portion is formed in the circumferential direction of the outer flange-like portion, and the main body rubber elastic body and the covering rubber layer are integrally formed by filling the notched portion with rubber.

4. The cylindrical vibration damping device according to claim 3, wherein a plurality of the notched portions having the filling rubber are provided in the circumferential direction of the outer cylindrical member.

5. The aforementioned rubber coating layer is provided with protruding portions that extend outward, The cylindrical vibration damping device according to claim 1 or 2, wherein the edge of the open portion of the color member is locked in place with respect to the protruding portion of the covering rubber layer in at least a portion thereof.

6. The protruding portion of the covering rubber layer extends in the circumferential direction, Multiple of these protruding portions are provided spaced apart from each other in the axial direction of the outer cylindrical member, The cylindrical vibration damping device according to claim 5, wherein the edge of the open portion of the collar member is locked to any one of the multiple protruding portions.

7. The cylindrical vibration damping device according to claim 1 or 2, wherein the axial dimension of the collar member is smaller than the axial dimension of the outer cylindrical member in at least a portion of the circumferential direction, and the opening is provided axially outward of the collar member.

8. The cylindrical vibration damping device according to claim 1 or 2, wherein the collar member has a window portion that penetrates radially, and the open portion of the collar member is formed by the window portion.

9. The cylindrical vibration damping device according to claim 1 or 2, wherein the inner circumferential corner of the edge of the opening in the color member has a chamfered shape with an inclined end surface that gradually widens toward the opening.

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