Cylindrical vibration-proofing device

Abstract

Provided is a cylindrical vibration-proofing device having a novel structure capable of preventing a resin outer member from being scraped when press-fitted into a collar member, while preventing the resin outer member from slipping out from the collar member.　In a cylindrical vibration-proofing device 10 (90) in which an inner shaft member 12 is inserted through a cylindrical resin outer member 14 (94), and the inner shaft member 12 and the resin outer member 14 (94) are connected by a body rubber elastic body 16, the resin outer member 14 (94) is provided with a slipping-out prevention protrusion 24 which protrudes on an outer peripheral surface and is inserted into a window part 50 (98) provided in a metal collar member 46 (92), and a relief part 36 (102) is provided to at least one of a fitting tip part to the collar member 46 in the resin outer member 14 and a tip edge part on the window part 98 side in a fitting surface 96 of the collar member 92 which is externally fitted to the resin outer member 94 nearer the fitting tip side than the window part 98.

Description

Cylindrical vibration isolator

[0001] The present invention relates to a cylindrical vibration isolator used, for example, as a subframe mount of an automobile.

[0002] Conventionally, a cylindrical vibration isolator used for a subframe mount of an automobile or the like has been known. As disclosed in, for example, Japanese Patent Application Laid-Open No. 2010-078101 (Patent Document 1), the cylindrical vibration isolator has a structure in which an inner shaft member and an outer cylinder member are connected by a main body rubber elastic body.

[0003] Japanese Patent Application Laid-Open No. 2010-078101

[0004] By the way, the outer cylinder member has conventionally been made of a metal such as iron or an aluminum alloy, but in Patent Document 1, it has been proposed to make the outer cylinder member of a synthetic resin for the purpose of reducing the weight of the cylindrical vibration isolator.

[0005] However, when a synthetic resin outer cylinder member (resin outer member) is used by being fitted into a collar member such as a subframe, etc., due to the continuous action of the fitting force directed to the inner circumference, changes (sagging) in shape and dimensions over time are likely to occur, and due to the sagging, the resistance to coming off decreases, and there is a risk that the resin outer member comes off from the collar member.

[0006] In Patent Document 1, it has also been proposed to secure the resistance to coming off by forming a circular retaining convex portion protruding from the outer peripheral surface of the resin outer member and locking it to a corresponding circular window portion in the collar member. In this Patent Document 1, the retaining convex portion is locked to the opening peripheral edge portion of the window portion in a state where the edge of the opening peripheral edge portion of the circular window portion bites into the peripheral wall surface of the circular retaining convex portion with a tapered shape.

[0007] However, with the structure of Patent Document 1, there is a concern that the resin outer member may be scraped at the edge of the window portion when it is pressed into the collar member. In particular, in partial window portions, the resin outer member, which is pushed inward in the portion outside the window portion, is prone to deforming to protrude outward in the window portion, and it has been found that the resin outer member is prone to getting stuck in the window portion and being scraped. Furthermore, if the interference fit of the resin outer member when it is pressed into the collar member is set to be large for purposes such as ensuring pull-out resistance or pre-compressing the main rubber elastic body during press-fitting, the resin outer member is more likely to be pressed against the edge of the window portion, which could particularly increase the likelihood of scraping of the resin outer member.

[0008] The problem to be solved by the present invention is to provide a cylindrical vibration damping device with a novel structure that can prevent the resin outer member from coming off the collar member while also preventing the resin outer member from being scraped when it is pressed into the collar member.

[0009] 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.

[0010] The first embodiment is a cylindrical vibration damping device in which an inner shaft member is inserted through a cylindrical resin outer member, and the inner shaft member and the resin outer member are connected by a main rubber elastic body, wherein the resin outer member is provided with a retaining projection that protrudes from its outer circumference and is inserted into a window provided in a metal collar member, and a relief portion is provided on at least one of the leading edge portion of the resin outer member that fits into the collar member and the leading edge portion on the window side of the fitting surface of the collar member that is fitted onto the resin outer member on the leading edge side of the window.

[0011] In the cylindrical vibration damping device constructed according to this embodiment, the retaining projection protruding from the outer surface of the resin outer member is inserted into the window portion of the collar member, thereby positioning the resin outer member relative to the collar member. As a result, even if the frictional force and other dislodgement resistance acting between the outer surface of the resin outer member and the inner surface of the collar member decreases due to aging of the resin outer member, the dislodgement of the resin outer member from the collar member is prevented by the locking of the retaining projection and the collar member. Therefore, while achieving weight reduction by using a resin outer member, the assembled state of the cylindrical vibration damping device relative to the collar member can be stably maintained.

[0012] In the process of fitting the resin outer member onto the collar member, the part of the resin outer member that is inserted beyond the retaining projection may be scraped by the edge of the window provided in the collar member as it passes through the opening of the window. Therefore, by providing a relief portion on at least one of the insertion tip portion of the resin outer member into the collar member and the window-side tip edge of the fitting surface of the collar member that is fitted onto the resin outer member beyond the insertion tip portion, when the resin outer member is press-fitted into the collar member, the insertion tip portion of the resin outer member is less likely to come into contact with the edge of the window on the fitting surface of the collar member. As a result, scraping of the resin outer member due to contact with the edge of the window as the insertion tip portion of the resin outer member passes through the opening of the window is prevented.

[0013] The second embodiment is a cylindrical vibration damping device as described in the first embodiment, wherein the leading edge of the resin outer member that fits into the collar member is provided with the relief portion relative to the collar member, and the relief portion is positioned on the fitting end side at a circumferentially corresponding position to the retaining projection.

[0014] In the cylindrical vibration damping device according to this embodiment, the tip portion of the resin outer member that fits into the collar member is provided with a relief portion for the collar member at a position corresponding to the retaining projection. As a result, the portion of the resin outer member that passes through the opening of the window portion at the tip portion that fits into the collar member is less likely to come into contact with the edge of the window portion due to the relief portion, thereby preventing the resin outer member from being worn down by the edge of the window portion.

[0015] The third embodiment is a cylindrical vibration isolation device described in the second embodiment, wherein the relief portion is a small-diameter portion in which the outer diameter is partially reduced.

[0016] In the cylindrical vibration damping device constructed according to this embodiment, the outer diameter of the resin outer member is reduced in the relief portion, so that the relief portion is separated inward from the inner surface of the collar member including the edge of the window portion. Therefore, when the relief portion passes through the opening of the window portion, it is possible to prevent the relief portion from contacting the edge of the window portion and to prevent abrasion of the resin outer member. Furthermore, according to this embodiment, the relief portion can be easily formed by a partial small-diameter portion.

[0017] The fourth aspect is a cylindrical vibration damping device as described in the third aspect, wherein the outer surface of the resin outer member in the small diameter portion has a tapered surface that inclins outward towards the outer circumference as it approaches the retaining projection in the axial direction.

[0018] In the cylindrical vibration isolation device constructed according to this embodiment, at the tip end of the resin outer member that is fitted into the collar member, where abrasion due to contact with the edge of the window portion is particularly likely to be a problem, the diameter of the resin outer member is made sufficiently small in the relief portion, thereby effectively preventing contact between the resin outer member and the edge of the window portion.

[0019] On the other hand, the portion of the relief section closest to the retaining projection is pushed inward by contact between the retaining projection and the inner surface of the collar member when passing through the opening of the window section, so contact with the edge of the window section is relatively less likely to be a problem. Therefore, by making the outer surface of the relief section tapered in the portion of the relief section closest to the retaining projection, it is possible to ensure the strength of the resin outer member which becomes partially thinned by the relief section, and to alleviate stress concentration by preventing abrupt changes in the cross-sectional shape.

[0020] The fifth embodiment is a cylindrical vibration damping device described in any one of the second to fourth embodiments, wherein the relief portion extends to the fitted tip of the resin outer member.

[0021] According to the cylindrical vibration isolation device constructed in accordance with this embodiment, a relief portion is provided that reaches the insertion tip of the resin outer member, thereby preventing abrasion of the resin outer member even at the insertion tip of the resin outer member, where abrasion by the edge of the window portion is likely to occur.

[0022] The sixth embodiment is a cylindrical vibration damping device described in any one of the second to fifth embodiments, wherein the collar member into which the resin outer member is fitted has a chamfered inner peripheral edge of the window portion located on the fitting tip side of the retaining projection.

[0023] According to the cylindrical vibration isolation device constructed in accordance with this embodiment, the chamfered shape of the inner peripheral edge of the window portion of the collar member also suppresses abrasion of the resin outer member due to contact with the inner peripheral edge of the window portion when the resin outer member is fitted into the collar member.

[0024] The seventh embodiment is a cylindrical vibration damping device as described in the first to sixth embodiments, wherein the relief portion for the resin outer member is provided on the edge of the fitting surface of the collar member that is fitted onto the resin outer member on the fitting tip side of the window portion, and the relief portion is inclined outward toward the fitting base end.

[0025] In the cylindrical vibration isolation device constructed according to this embodiment, the relief portion provided on the press-fit surface of the collar member is shaped to incline outward toward the outer circumference toward the base end of the insertion. As a result, when the insertion tip portion of the resin outer member passes through the opening of the window portion, the tip edge of the window portion on the press-fit surface of the collar member (the edge of the window portion) is less likely to dig into the resin outer member, and abrasion of the resin outer member by the edge of the window portion is prevented.

[0026] The eighth aspect is a cylindrical vibration damping device as described in the seventh aspect, wherein the inner circumferential surface of the relief portion has a maximum protrusion of 0.1 mm or more from the outer circumference relative to the fitting surface of the collar member.

[0027] In the cylindrical vibration damping device constructed according to this embodiment, the relief portion of the collar member is sufficiently far from the press-fit surface to the outer circumference, thereby more effectively preventing abrasion of the resin outer member due to contact with the edge of the window portion.

[0028] The ninth embodiment is a cylindrical vibration isolation device described in any one of the first to eighth embodiments, wherein the circumferential width dimension of the relief portion is 50% or more of the circumferential width dimension of the retaining projection.

[0029] According to the cylindrical vibration isolation device constructed in accordance with this embodiment, the circumferential width dimension of the relief portion is set to be sufficiently large compared to the circumferential width dimension of the retaining projection inserted into the window portion, thereby effectively preventing contact of the resin outer member with the edge of the window portion and preventing abrasion of the resin outer member when fitted into the collar member.

[0030] The tenth aspect is a cylindrical vibration damping device as described in the ninth aspect, wherein the circumferential width dimension of the relief portion is larger than the circumferential width dimension of the retaining projection, and the relief portion extends beyond the retaining projection on both sides.

[0031] According to the cylindrical vibration damping device with a structure conforming to this embodiment, the relief portion is provided to extend beyond the retaining projection on both sides, thereby more effectively preventing contact between the resin outer member and the edge of the window portion, and more effectively preventing wear of the resin outer member.

[0032] The eleventh embodiment is a cylindrical vibration damping device described in any one of the first to tenth embodiments, wherein a pair of retaining projections are provided on both radial sides of the resin outer member, and a pair of relief portions are provided on the resin outer member at circumferential positions corresponding to the pair of retaining projections.

[0033] According to the cylindrical vibration isolation device constructed in accordance with this embodiment, a pair of retaining protrusions are inserted into a pair of window portions of the collar member, preventing the resin outer member from coming out of the collar member on both radial sides, thereby enabling a well-balanced and large resistance to dislodgement.

[0034] By providing a pair of relief portions at circumferential positions corresponding to the pair of retaining protrusions, the wear of the resin outer member by the edges of the pair of window portions corresponding to the pair of retaining protrusions is prevented by the pair of relief portions.

[0035] According to the present invention, in a cylindrical vibration damping device equipped with a resin outer member, it is possible to prevent the resin outer member from coming off the collar member while also preventing the resin outer member from being scraped when it is pressed into the collar member.

[0036] Front view of the subframe mount as the first embodiment of the present invention Right side view of the subframe mount shown in Figure 1 Plan view of the subframe mount shown in Figure 1 Sectional view of IV-IV in Figure 1 Front view showing the subframe mount shown in Figure 1 Crossal view of VI-VI in Figure 5 Crossal view of VII-VII in Figure 5 Front view of the subframe mount as the second embodiment of the present invention Right side view of the subframe mount shown in Figure 8 Front view showing the subframe mount shown in Figure 8 Crossal view of the subframe mount shown in Figure 8 Crossal view of the subframe mount shown in the color member Front view showing the subframe mount as the third embodiment of the present invention in the state of being attached to fourth embodiment of the present invention in the state of being attached to the color member Crossal view of XIII-XIII in Figure 12 Crossal view of XIV-XIV in Figure 12

[0037] Embodiments of the present invention will be described below with reference to the drawings.

[0038] Figures 1 to 4 show a subframe mount 10 for automobiles as a first embodiment of a cylindrical vibration damping device with a structure according to the present invention. The subframe mount 10 has a structure in which an inner shaft member 12 is inserted through a cylindrical resin outer member 14, and the inner shaft member 12 and the resin outer member 14 are connected by a main rubber elastic body 16. In the following description, as a general rule, the vertical direction refers to the vertical direction in Figure 1, which is the axial direction, the front-rear direction refers to the left-right direction in Figure 2, and the left-right direction refers to the left-right direction in Figure 1.

[0039] The inner shaft member 12 has a thick, small-diameter, substantially cylindrical shape and extends straight with a substantially constant cross-sectional shape, as shown in Figure 4. The inner shaft member 12 is made of a rigid material, such as iron or aluminum alloy, or fiber-reinforced synthetic resin.

[0040] The resin outer member 14 is provided with a substantially cylindrical tubular portion 18. The tubular portion 18 is thinner and larger in diameter than the inner shaft member 12. The resin outer member 14 is made of synthetic resin, and is formed from, for example, polyamide, polyacetal, polybutylene terephthalate, polyethylene, polytetrafluoroethylene, etc. The resin outer member 14 may be formed from the above-mentioned synthetic resin material alone, but preferably it is formed from fiber-reinforced synthetic resin reinforced with glass fibers, carbon fibers, aramid fibers, etc.

[0041] A ring-shaped flange portion 20 that protrudes outward is integrally formed at the lower end of the resin outer member 14. The outer circumferential surface of the upper end of the resin outer member 14 is a tapered press-fit guide surface 22 that becomes smaller in diameter towards the top. The inner circumferential surface of the upper end of the resin outer member 14 protrudes inward compared to the inner circumferential surfaces of other parts, but the formation of the press-fit guide surface 22 makes it thinner towards the top.

[0042] The resin outer member 14 has a pair of retaining projections 24, 24 that protrude from the outer circumferential surface of the cylindrical portion 18. As shown in Figure 1, the retaining projections 24 are approximately square in shape when viewed in the front-to-back direction, and in this embodiment, they are approximately rectangular. As shown in Figures 2 to 4, the retaining projections 24 are provided on both sides in the radial direction (front-to-back direction). In the front-to-back direction, the retaining projections 24 have a pair of first convex opposite sides that extend circumferentially on a plane perpendicular to the axial direction at both ends in the axial direction, and a pair of second convex opposite sides that extend parallel to the axial direction at both ends in the circumferential direction.

[0043] As shown in Figure 4, the height of the retaining projection 24 protruding from the outer circumferential surface of the cylindrical portion 18 varies in the axial direction. More specifically, the protruding tip surface of the retaining projection 24 is a guide surface 30 at the top that inclines inward toward the inner circumference upward, and a locking surface 32 at the bottom that inclines outward toward the outer circumference upward. In addition, a tip surface 34 is provided between the guide surface 30 and the locking surface 32 on the protruding tip surface of the retaining projection 24, extending non-inclined with respect to the axial direction. The locking surface 32 constitutes the lower first convex side opposite side and extends circumferentially on a plane perpendicular to the axial direction.

[0044] It is desirable that the maximum protruding height dimension of the retaining convex portion 24 is smaller than the radial thickness dimension T of the cylindrical portion 18 of the resin outer member 14, and more preferably within the range of 1 / 4 to 1 / 2 of the thickness dimension T of the cylindrical portion 18. The axial length dimension of the retaining convex portion 24 is desirably within the range of 1 / 10 to 1 / 2 with respect to the axial length dimension of the cylindrical portion 18 of the resin outer member 14, and more preferably within the range of 1 / 7 to 1 / 4. The circumferential width dimension of the retaining convex portion 24 is desirably within the range of 1 / 20 to 1 / 3 with respect to the circumferential length of the cylindrical portion 18 of the resin outer member 14, and more preferably within the range of 1 / 15 to 1 / 8.

[0045] The inclination angle of the guide surface 30 with respect to the axial direction is smaller than the inclination angle of the locking surface 32 with respect to the axial direction. In the present embodiment, the inclination angle of the guide surface 30 with respect to the axial direction is constant, and the inclination angle of the locking surface 32 with respect to the axial direction is constant. Therefore, the axial length dimension of the guide surface 30 is larger than the axial length dimension of the locking surface 32. The inclination angle of the guide surface 30 is preferably desirably within the range of 2 to 10 degrees. The inclination angle of the locking surface 32 is preferably desirably within the range of 20 to 30 degrees. Note that the inclination angle of the guide surface 30 may vary in magnitude in the axial direction. Similarly, the inclination angle of the locking surface 32 may vary in magnitude in the axial direction. Therefore, the guide surface 30 and the locking surface 32 are not limited to being constituted by a single plane, and for example, they may be constituted by a plurality of planes having different inclination angles from each other, or may be constituted by a curved surface in which the inclination angle continuously changes.

[0046] The resin outer member 14 is provided with a pair of small-diameter portions 36, 36 as relief portions. The small-diameter portions 36 are provided at the upper end portion of the cylindrical portion 18, which is the fitting tip portion to the collar member 46 described later, in the resin outer member 14. The outer diameter dimension of the resin outer member 14 is partially reduced in the circumferential direction at the small-diameter portions 36. The pair of small-diameter portions 36, 36 are provided on both sides in one radial direction (front-rear direction). The pair of small-diameter portions 36, 36 may have different sizes and shapes from each other, but in the present embodiment, they have substantially the same size and shape.

[0047] As shown in FIGS. 1 and 3, a pair of small-diameter portions 36, 36 are provided at positions corresponding to the pair of retaining projections 24, 24 in the circumferential direction, on the fitting tip side of the resin outer member 14 with respect to the pair of retaining projections 24, 24. In the present embodiment, the circumferential centers of the pair of small-diameter portions 36, 36 and the circumferential centers of the pair of retaining projections 24, 24 are arranged so as to be substantially the same position in the circumferential direction. Therefore, the small-diameter portion 36 is arranged side by side with the retaining projection 24 in the axial direction, and is located on the upper side, which is the side opposite to the flange-shaped portion 20 with respect to the retaining projection 24. The small-diameter portion 36 and the retaining projection 24 are arranged slightly separated from each other in the axial direction in the present embodiment, but may be arranged continuously in the axial direction, for example.

[0048] It is desirable that the circumferential width dimension W1 of the small-diameter portion 36 is 50% or more with respect to the circumferential width dimension W2 of the retaining projection 24, and more preferably 80% or more (see FIG. 1). The circumferential width dimension W1 of the small-diameter portion 36 is more preferably larger than the circumferential width dimension W2 of the retaining projection 24. The circumferential width dimension W1 of the small-diameter portion 36 in the present embodiment is 200% or more with respect to the circumferential width dimension W2 of the retaining projection 24, and is not less than the circumferential width dimension W3 (see FIG. 5) of the window portion 50 of the color member 46 described later. The small-diameter portion 36 in the present embodiment is arranged at substantially the same position as the retaining projection 24 in the circumferential direction, and is provided so as to extend to both outer sides in the circumferential direction with respect to the retaining projection 24.

[0049] As shown in Figures 1 and 4, the small-diameter portion 36 extends to the upper end of the resin outer member 14 and is concave, opening to the outer circumferential surface and upper end surface of the resin outer member 14. In the portion of the resin outer member 14 where the small-diameter portion 36 is formed, the resin outer member 14 is thinner in the radial direction compared to other parts that are circumferentially away from the small-diameter portion 36. As shown in Figures 2 and 4, the outer circumferential surface of the resin outer member 14 in the small-diameter portion 36 has a cylindrical surface 38 at the top that extends non-inclined in the axial direction of the resin outer member 14, and a tapered surface 40 at the bottom that inclins outward as it goes downward toward the retaining projection 24 side. Therefore, the outer diameter of the portion of the resin outer member 14 formed by the bottom surface of the small-diameter portion 36 is approximately constant at the top and increases in diameter downward toward the bottom. In this embodiment, the small diameter portion 36 has both circumferential end faces that extend substantially perpendicular to the front-rear direction, but for example, they may extend substantially parallel to the front-rear direction or extend radially. Also, in this embodiment, as shown in Figure 1, the circumferential width dimension of the cylindrical surface 38 of the small diameter portion 36 is made larger than the circumferential width dimension W2 of the retaining projection 24.

[0050] The inclination angle of the tapered surface 40 with respect to the axial direction is not particularly limited, but is preferably in the range of 1 to 20 degrees, and more preferably in the range of 2 to 10 degrees. In this embodiment, the inclination angle of the tapered surface 40 with respect to the axial direction is approximately constant, but may vary in the axial direction, for example.

[0051] The maximum depth dimension D of the small-diameter portion 36 (depth dimension at the cylindrical surface 38) is preferably within the range of 1 / 4 to 2 / 3 times the radial thickness dimension T of the cylindrical portion 18 in the resin outer member 14, and more preferably within the range of 1 / 3 to 1 / 2 times (see Figure 4). This ensures sufficient separation distance of the small-diameter portion 36 from the collar member 46, which will be described later, while preventing excessive thinning of the resin outer member 14, thereby ensuring the strength of the resin outer member 14 and preventing cracking.

[0052] The inner shaft member 12 and the resin outer member 14 are connected by a main rubber elastic body 16. That is, the inner shaft member 12 is inserted into the inner circumference of the resin outer member 14, and the main rubber elastic body 16 is formed radially between the inner shaft member 12 and the resin outer member 14. The main rubber elastic body 16 has a thick, substantially cylindrical shape overall, with its inner circumferential surface vulcanized and bonded to the outer circumferential surface of the inner shaft member 12, and its outer circumferential surface vulcanized and bonded to the inner circumferential surface of the cylindrical portion 18 of the resin outer member 14. The main rubber elastic body 16 is formed as an integrally vulcanized molded product comprising the inner shaft member 12 and the resin outer member 14.

[0053] The lower end surface of the main rubber elastic body 16 is a curved surface with a concave groove that opens downward. On the outer circumference of the main rubber elastic body 16 beyond the groove, a first stopper portion 42 is provided that protrudes downward. The first stopper portion 42 is fixed to the lower surface of the flange-like portion 20 of the resin outer member 14 and protrudes downward from the flange-like portion 20. A second stopper portion 44 is integrally provided at the outer circumference end of the main rubber elastic body 16, covering the inner circumference of the upper surface of the resin outer member 14 and protruding upward from the resin outer member 14.

[0054] The subframe mount 10, having the structure described above, is fitted into a cylindrical collar member 46 and attached to the vehicle, as shown in Figures 5 to 7. The collar member 46, for example, constitutes a part of the vehicle's subframe and has a substantially cylindrical shape with mounting holes 48. The collar member 46 is a highly rigid member made of a metal such as iron.

[0055] The color member 46 has a pair of window portions 50, 50 formed on both sides in the front-rear direction. The window portions 50 are formed by passing through the peripheral wall of the mounting hole 48 in the radial direction. The window portions 50 are approximately rectangular in shape when viewed in the front-rear direction, and in this embodiment, they are approximately rectangular with rounded corners. The axial portions of the window portions 50 on both sides of the opening edge are a pair of first window-side opposite sides located on a plane perpendicular to the axial direction, and the circumferential portions on both sides are a pair of second window-side opposite sides extending approximately parallel to the axial direction.

[0056] The window portion 50 is formed, for example, by punching out a color member 46 in the radial direction (front-to-back direction), and as shown in Figure 7, the inner peripheral edge of the opening forms an angle of approximately 90 degrees. In the following description, the first inner peripheral edge 56 of the window portion 50 refers to the inner edge of the window portion 50 at the upper first window-side opposite side, and the second inner peripheral edge 58 of the window portion 50 refers to the inner edge of the window portion 50 at the lower first window-side opposite side.

[0057] The window portion 50 has a larger area in the front-to-back view compared to the retaining projection 24 of the resin outer member 14. Also, as shown in Figure 5, the ratio of the left-to-right width dimension of the window portion 50 to the vertical length dimension is greater than the ratio of the left-to-right width dimension of the retaining projection 24, and the window portion 50 has a flattened shape that is longer from left to right than the retaining projection 24.

[0058] The axial length dimension L3 of the window portion 50 is preferably larger than the axial length dimension of the retaining projection 24 of the resin outer member 14, and more preferably 1.05 times or more the axial length dimension of the retaining projection 24. Also, the circumferential width dimension W3 of the window portion 50 is larger than the circumferential width dimension W2 of the retaining projection 24 of the resin outer member 14. The circumferential width dimension W3 of the window portion 50 is preferably in the range of 1.1 to 3 times the circumferential width dimension W2 of the retaining projection 24, and more preferably in the range of 1.2 to 2 times.

[0059] The axial length dimension L3 of the window portion 50 is preferably within the range of 1 / 8 to 1 / 2 of the axial length dimension of the color member 46, and more preferably within the range of 1 / 5 to 1 / 3. Furthermore, the circumferential width dimension W3 of the window portion 50 is preferably within the range of 1 / 30 to 1 / 3 of the circumference of the color member 46, and more preferably within the range of 1 / 20 to 1 / 5.

[0060] The resin outer member 14 of the subframe mount 10 is fitted into the mounting hole 48 of the collar member 46. The outer diameter of the cylindrical portion 18 of the resin outer member 14 is slightly larger than the inner diameter of the collar member 46, so that the cylindrical portion 18 is fitted to the collar member 46 with a radial overlap. In addition, the flange-like portion 20 provided at the lower end of the resin outer member 14 abuts against the lower end surface of the collar member 46 in the vertical direction, thereby setting the axial relative position of the resin outer member 14 with respect to the collar member 46.

[0061] Since the outer circumferential surface of the upper end of the resin outer member 14 is a press-fit guide surface 22 that tapers upward, the resin outer member 14 is easily fitted onto the collar member 46 from below. In this embodiment, the minimum outer diameter of the press-fit guide surface 22 is smaller than the inner diameter of the collar member 46, and by inserting the upper end of the resin outer member 14 into the collar member 46, the resin outer member 14 and the collar member 46 can be positioned relative to each other radially before fitting.

[0062] The retaining projection 24 protruding from the outer surface of the resin outer member 14 is inserted into the window portion 50 of the collar member 46. The protruding tip surface of the retaining projection 24 is a guide surface 30 with an inclined shape that tapers towards the insertion direction on the side that fits into the collar member 46, making it easier for the collar member 46 to overcome the retaining projection 24 and easier to insert the retaining projection 24 into the window portion 50.

[0063] The lower opening edge of the window portion 50 (the opposite side of the first window) is located on the locking surface 32 of the retaining projection 24 and is locked to the retaining projection 24 in the axial direction. This makes it difficult for the resin outer member 14 to come loose from the collar member 46 due to downward displacement. In particular, since the cylindrical portion 18 of the resin outer member 14 made of synthetic resin is fitted into the collar member 46, a force directed inward from the collar member 46 is continuously applied to the cylindrical portion 18, and the cylindrical portion 18 may undergo plastic deformation (sagging) due to long-term deterioration, which may reduce the resistance of the cylindrical portion 18 to coming loose from the collar member 46. To address the specific challenges of the resin outer member 14, an axial locking structure is provided between the retaining projection 24 and the opening peripheral edge of the window portion 50 of the collar member 46. This ensures that even if the resistance to dislodgement due to fitting decreases due to wear of the cylindrical portion 18 of the resin outer member 14, the locking structure provided by the retaining projection 24 can stably secure the necessary resistance to dislodgement. Since the resin outer member 14 is made of synthetic resin, it offers a high degree of freedom in shape, allowing for a wide range of freedom in setting the shape and size of the retaining projection 24 protruding from the outer circumferential surface.

[0064] The locking surface 32 of the retaining projection 24, which is the locking portion for the first window-side opposite edge on the lower side of the window portion 50, has an inclined shape that slopes outward toward the outer circumference toward the tip side in the insertion direction. As a result, even if a relative axial displacement occurs between the retaining projection 24 and the window portion 50, the first window-side opposite edge remains stably positioned on the locking surface 32 of the retaining projection 24, thereby reliably preventing the resin outer member 14 from coming out of the collar member 46. In this embodiment, the second inner peripheral edge 58 of the first window-side opposite edge of the collar member 46 bites into the locking surface 32 of the retaining projection 24, resulting in a stronger retaining effect, and even if the relative axial position of the retaining projection 24 and the window portion 50 is shifted, the first window-side opposite edge of the window portion 50 is more easily locked in contact with the locking surface 32 of the retaining projection 24. Furthermore, the first window-side opposite side portion, which includes the second inner peripheral edge portion 58, extends circumferentially on a plane perpendicular to the axial direction.

[0065] Furthermore, in the retaining projection 24, the inclination angle of the locking surface 32 is greater than the inclination angle of the guide surface 30. As a result, the collar member 46 is guided by the guide surface 30 with a small inclination angle, making it easier for the collar member 46 to overcome the retaining projection 24, while the locking surface 32 with a large inclination angle effectively catches and locks onto the opposite side of the first window of the window 50, thereby providing greater resistance to the resin outer member 14 coming off the collar member 46.

[0066] The retaining projections 24 and window portions 50 are provided on both the radial sides of the resin outer member 14 and the collar member 46, respectively. Therefore, on both radial sides where each retaining projection 24 and window portion 50 is formed, resistance forces against the resin outer member 14 coming out of the collar member 46 are exerted, making it more difficult for the resin outer member 14 to come out of the collar member 46. Furthermore, since the resistance forces against the resin outer member 14 from the collar member 46 act on both radial sides, the moments caused by these resistance forces cancel each other out, preventing tilting (twisting displacement) of the resin outer member 14 and the collar member 46 caused by the resistance forces.

[0067] The first convex side opposite the retaining projection 24, which is composed of a locking surface 32, and the first window side opposite the window portion of the window portion 50, which is locked to the locking surface 32, both extend in a direction perpendicular to the axial direction. As a result, the locking portion between the locking surface 32 of the retaining projection 24 and the first window side opposite the window portion of the window portion 50 extends in a direction perpendicular to the axial direction. Therefore, the resistance force against axial dislodgement of the resin outer member 14 from the collar member 46 is exerted more efficiently by the locking between the locking surface 32 of the retaining projection 24 and the first window side opposite the window portion of the window portion 50.

[0068] Since the retaining projection 24 has a smaller axial width dimension compared to the window portion 50, as shown in Figure 5, the upper first protruding side of the retaining projection 24 and the upper first window side of the window portion 50 are separated from each other in the axial direction. As a result, an axial gap 60 is formed between the upper first protruding side of the retaining projection 24 and the upper first window side of the window portion 50 in the axial direction. The axial gap 60 is provided continuously along the entire circumferential length of the retaining projection 24.

[0069] Since the circumferential width dimension of the retaining projection 24 is smaller than that of the window portion 50, as shown in Figures 5 and 6, the second convex side opposite the retaining projection 24 and the second window side opposite the window portion 50 are separated from each other in the circumferential direction, and circumferential gaps 62 are formed between the second convex side opposite the second window side opposite the window portion. The circumferential gaps 62, 62 are provided continuously along the entire axial length of the retaining projection 24. Note that the circumferential gaps 62, 62 formed on both sides of the retaining projection 24 in the circumferential direction may have different circumferential width dimensions.

[0070] The circumferential gaps 62, 62 are continuous with the axial gap 60 at the upper end, and these circumferential gaps 62, 62 and the axial gap 60 form a gap 64 that extends continuously around the retaining projection 24 in an inverted U-shape. In this embodiment, as shown in Figure 5, the circumferential width dimension of the circumferential gap 62 is larger than the axial width dimension of the axial gap 60.

[0071] The formation of such a gap 64 allows for relative positional misalignment and dimensional errors between the retaining projection 24 on the resin outer member 14 and the window portion 50 of the collar member 46. Therefore, for example, it prevents the retaining projection 24 from overlapping the inner circumference of the collar member 46 in a position away from the window portion 50, and ensures that the locking surface 32 of the retaining projection 24 and the first window-side opposite edge on the lower side of the window portion 50 are stably locked together, thereby effectively achieving the desired retaining effect.

[0072] In this embodiment, the width dimension of the circumferential gap 62 is larger than the width dimension of the axial gap 60. As a result, the relative positional displacement in the circumferential direction between the retaining projection 24 of the resin outer member 14 and the window portion 50 of the collar member 46 is allowed to be larger than the relative positional displacement in the axial direction. Both the retaining projection 24 and the window portion 50 are located radially separated from the central axis of the subframe mount 10 and the collar member 46. As a result, even when the resin outer member 14 and the collar member 46 are displaced in the circumferential direction by a small rotation angle, the relative displacement between the retaining projection 24 and the window portion 50 tends to be relatively large. Therefore, in the circumferential direction where large positional displacements are likely to occur, the larger width dimension of the circumferential gap 62, 62 allows for greater tolerance of positional displacement, making it difficult for the retaining projection 24 to detach from the window portion 50 when the subframe mount 10 is attached to the collar member 46.

[0073] In this embodiment, the retaining projection 24 and the window portion 50 are each approximately rectangular in shape, and the first convex side opposite the retaining projection 24 and the first window side opposite the window portion 50, which are located across the axial gap 60, face each other at a constant distance in the circumferential direction. Therefore, relative positional displacement in the axial direction between the retaining projection 24 and the window portion 50 can be efficiently accommodated without excessively increasing the width dimension of the axial gap 60. Furthermore, the second convex side opposite the retaining projection 24 and the second window side opposite the window portion 50, which are located across the circumferential gaps 62, 62, face each other at a constant distance in the axial direction. Therefore, relative positional displacement in the circumferential direction between the retaining projection 24 and the window portion 50 can be efficiently accommodated without excessively increasing the width dimension of the circumferential gap 62.

[0074] However, since the resin outer member 14 is fitted into the collar member 46 in a reduced diameter state, there was a risk that the part of the resin outer member 14 on the side of the insertion tip (upper side) relative to the retaining projection 24 would enter the window portion 50 of the collar member 46 as it passed through the opening of the window portion 50, and come into contact with and be worn down by the first inner peripheral edge 56 of the window portion 50. Therefore, in the subframe mount 10 of this embodiment, a small diameter portion 36 is provided as a relief portion at a circumferential position corresponding to the retaining projection 24 of the resin outer member 14, and on the insertion tip side relative to the retaining projection 24. As a result, the outer diameter of the resin outer member 14 is partially reduced in the portion that may come into contact with the first inner peripheral edge 56 of the window portion 50. Furthermore, when fitting the resin outer member 14 into the color member 46, contact between the resin outer member 14 and the first inner peripheral edge 56 of the window portion 50 is avoided, thereby preventing the resin outer member 14 from being scraped by the first inner peripheral edge 56 of the window portion 50. As a result, damage to the resin outer member 14 is avoided, and the generation of shavings from the resin outer member 14 is prevented.

[0075] Because the relief portion is composed of a small-diameter portion 36, the resin outer member 14 is a continuous cylindrical shape in the circumferential direction even in the relief portion, and the fixing force exerted by fitting the resin outer member 14 onto the collar member 46 is more effectively exerted. In addition, the relief portion can be easily formed by partially reducing the outer diameter of the resin outer member 14.

[0076] The small-diameter portion 36 is a cylindrical surface 38 with the smallest diameter at the end of the resin outer member 14 that is fitted into the collar member 46, where abrasion due to contact with the first inner peripheral edge 56 of the window portion 50 is particularly likely to be a problem. Therefore, contact between the fitted end of the resin outer member 14 and the first inner peripheral edge 56 of the window portion 50 is effectively prevented by the small-diameter portion 36.

[0077] On the other hand, the portion of the small-diameter section 36 closest to the retaining projection 24 is pushed inward by contact between the retaining projection 24 and the inner circumferential surface of the collar member 46 when passing through the opening of the window section 50, so contact with the first inner circumferential edge 56 of the window section 50 is relatively unlikely to be a problem. Therefore, by making the outer circumferential surface of the portion of the small-diameter section 36 closest to the retaining projection 24 a tapered surface 40, it is possible to ensure the strength of the resin outer member 14 which is partially thinned by the small-diameter section 36, and to alleviate stress concentration by preventing abrupt changes in the cross-sectional shape.

[0078] Because the small-diameter portion 36 reaches the insertion tip of the resin outer member 14 and opens to the axial end face of the resin outer member 14, the small-diameter portion 36 can prevent abrasion of the resin outer member 14, even at the insertion tip of the resin outer member 14, where abrasion by the first inner peripheral edge 56 of the window portion 50 is likely to occur.

[0079] The circumferential width dimension W1 of the small diameter portion 36 is set to be 50% or more of the circumferential width dimension W2 of the retaining projection 24, which is set according to the circumferential width dimension W3 of the window portion 50. This effectively prevents the resin outer member 14 from being worn down by contact with the first inner peripheral edge 56 of the window portion 50. In particular, since the circumferential width dimension W1 of the small diameter portion 36 is larger than the circumferential width dimension W2 of the retaining projection 24, and the small diameter portion 36 extends to both outer sides in the circumferential direction beyond the retaining projection 24, contact between the resin outer member 14 and the first inner peripheral edge 56 of the window portion 50 is more effectively prevented. In this embodiment, since the circumferential width dimension W1 of the small diameter portion 36 is larger than the circumferential width dimension W3 of the window portion 50, contact between the resin outer member 14 and the first inner peripheral edge 56 of the window portion 50 is more advantageously prevented, and wear on the resin outer member 14 is further reduced.

[0080] Furthermore, in the state in which the subframe mount 10 is attached to the collar member 46 as shown in Figure 5, the distance L1 from the upper end of the collar member 46 to the lower end of the small diameter portion 36 is greater than the distance L2 from the upper end of the collar member 46 to the first inner peripheral edge portion 56 of the window portion 50. As a result, the lower end of the small diameter portion 36 is located below the first inner peripheral edge portion 56, and the lower end of the small diameter portion 36 is exposed to the window portion 50. Therefore, when the resin outer member 14 is fitted into the collar member 46, the first inner peripheral edge portion 56 of the window portion 50 does not come into contact with the resin outer member 14 below the small diameter portion 36, and the first inner peripheral edge portion 56 is located on the outer circumference side of the small diameter portion 36. As a result, abrasion of the resin outer member 14 due to pressure from the first inner peripheral edge portion 56 is reliably prevented from the start to the end of fitting the resin outer member 14 into the collar member 46.

[0081] The small-diameter portions 36 are provided at circumferential positions corresponding to the pair of retaining projections 24, 24. Therefore, abrasion of the resin outer member 14 by the first inner peripheral edges 56, 56 of the pair of window portions 50, 50 of the color member 46 is prevented by the small-diameter portions 36, 36.

[0082] While the dimensions of each component in the subframe mount 10 are not limited, for example, if the axial length (length of the press-fit surface) dimension L4 from the upper end of the retaining projection 24 to the lower end of the press-fit guide surface 22 in the resin outer member 14 in Figure 1 is long, the present invention is particularly applicable when wear of the resin outer member 14 is likely to become a problem. For example, when the axial length dimension L4 of the press-fit surface is larger than the axial length dimension L3 of the window portion 50, wear of the resin outer member 14 is particularly likely to become a problem, but wear can be suppressed by applying the structure of the present invention. Also, when the circumferential length dimension (circumferential width dimension W3) of the window portion 50 is large, wear of the resin outer member 14 is likely to occur, and the present invention can effectively suppress wear. Furthermore, the area of ​​the resin outer member 14 from the upper end of the retaining projection 24 to the lower end of the press-fit guide surface 22, excluding the small diameter portions 36, 36, is designated as the press-fit portion for the collar member 46, and the inner circumferential surface of the collar member 46 above the window portion 50 has a fitting surface that is fitted onto the aforementioned area of ​​the resin outer member 14.

[0083] Figures 8 and 9 show a subframe mount 70 as a second embodiment of the cylindrical vibration isolation device according to the present invention. In the following description, components and parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals in the figures and their descriptions are omitted.

[0084] The subframe mount 70 has a small-diameter portion 74 formed as a relief portion above the retaining projection 24 on the resin outer member 72. The small-diameter portion 74 in this embodiment is formed by providing a flat surface 76 perpendicular to the front-rear direction and a tapered surface 78 that is on the side of the retaining projection 24 closer to the retaining projection 24 than the flat surface 76, and is inclined outward toward the retaining projection 24, on the outer circumferential surface of the resin outer member 72. The small-diameter portion 74 in this embodiment has a simpler shape, consisting of two surfaces: the flat surface 76 and the tapered surface 78.

[0085] The flat surface 76 extends to the upper end of the resin outer member 72 and is also formed on the press-fit guide surface 22 that constitutes the upper end of the resin outer member 72. The upper part of the flat surface 76 formed on the press-fit guide surface 22 narrows in the circumferential direction as it goes upward. The lower part of the flat surface 76 that is off the press-fit guide surface 22 has a circumferential width that is approximately constant in the vertical direction, and the small diameter portion 74 is the part with the largest circumferential width.

[0086] The tapered surface 78 is a plane inclined at a substantially constant angle with respect to the axial direction, with its upper end continuous with the flat surface 76 and its lower end slightly separated upward from the retaining projection 24. The inclination angle of the tapered surface 78 is not particularly limited, but is preferably in the range of 1 to 10 degrees, and more preferably in the range of 2 to 5 degrees. The circumferential width dimension of the tapered surface 78 gradually decreases as it goes downward. In the front-to-back projection, the vertical length dimension of the tapered surface 78 is greater than or equal to the vertical length dimension of the flat surface 76, and is preferably in the range of 100 to 150% of the vertical length dimension of the flat surface 76.

[0087] The maximum circumferential width W1 of the small diameter portion 74 is preferably greater than 50% of the circumferential width W2 of the retaining projection 24, more preferably greater than 80%, and even more preferably greater than 100%. In this embodiment, the maximum circumferential width W1 of the small diameter portion 74 is preferably greater than the circumferential width W2 of the retaining projection 24. The circumferential widths of the upper and lower ends of the small diameter portion 74 are smaller than the circumferential width W2 of the retaining projection 24, but the circumferential width of the upper end of the small diameter portion 74 is greater than 50% of the circumferential width W2 of the retaining projection 24. Therefore, the circumferential width of the small diameter portion 74 is greater than 50% of the circumferential width W2 of the retaining projection 24 over the entire upper and lower length of the upper part composed of the flat surface 76.

[0088] As can be seen from Figure 10, which shows the mounting state of the color member 46, the maximum circumferential width dimension W1 of the small diameter portion 74 is larger than 50% of the circumferential width dimension W3 of the window portion 50 of the color member 46, and more preferably larger than 90% of the circumferential width dimension W3 of the window portion 50. In this embodiment, the case in which the maximum width dimension W1 of the small diameter portion 74 is smaller than the circumferential width dimension W3 of the window portion 50 is illustrated, but as in the first embodiment, the maximum width dimension W1 of the small diameter portion 74 may be larger than the circumferential width dimension W3 of the window portion 50.

[0089] In the resin outer member 72 equipped with such a small-diameter portion 74, similar to the first embodiment, abrasion caused by contact with the upper inner circumferential edge (first inner circumferential edge) of the window portion 50 of the collar member 46 is prevented by the small-diameter portion 74. In particular, at the insertion tip (upper end) where abrasion during fitting of the resin outer member 72 into the collar member 46 is a problem, the small-diameter portion 74 is composed of a flat surface 76, and both the circumferential width dimension and the depth dimension in the front-rear direction of the small-diameter portion 74 are sufficiently large, so contact between the upper inner circumferential edge of the window portion 50 and the resin outer member 72 is less likely to be a problem.

[0090] Figure 11 shows a subframe mount 10 attached to a collar member 80 as a third embodiment of the cylindrical vibration damping device according to the present invention. The collar member 80 has a chamfered first inner peripheral edge 82, which is the upper inner peripheral edge of the window portion 50, and the first inner peripheral edge 82 has a tapered surface that slopes upward toward the inner circumference. The tapered surface of the first inner peripheral edge 82 may be a linear inclined shape with a constant inclination angle, or it may be an inclined shape in which the inclination angle changes in steps or continuously. Therefore, the tapered surface of the first inner peripheral edge 82 may be obtuse by chamfering with a C-chamfer, or it may be curved by chamfering with an R-chamfer. Preferably, the angle that the tapered surface of the first inner peripheral edge 82 makes with the inner peripheral surface of the collar member 80 in the vertical cross-section shown in Figure 11 is greater than 90 degrees.

[0091] With the structure according to this embodiment, abrasion of the resin outer member 14 due to contact with the first inner peripheral edge 82 of the collar member 80 is less likely to occur due to the chamfered shape of the first inner peripheral edge 82. Even if a part of the resin outer member 14 that is outside the relief portion, such as the space between the retaining projection 24 and the small diameter portion 36 of the resin outer member 14, comes into contact with the first inner peripheral edge 82, abrasion of the resin outer member 14 can be reduced because the first inner peripheral edge 82 is chamfered and the angle between the tapered surface of the first inner peripheral edge 82 and the inner peripheral surface of the collar member 80 is obtuse. In this embodiment, the relief portion is composed of the small diameter portion 36 provided on the resin outer member 14 and the chamfer of the first inner peripheral edge 82 provided on the collar member 80, and relief portions are provided on both the resin outer member 14 and the collar member 80.

[0092] Figures 12 to 14 show a fourth embodiment of the cylindrical vibration damping device according to the present invention, in which the subframe mount 90 is attached to the collar member 92. As shown in Figures 13 and 14, the subframe mount 90 has a structure in which an inner shaft member 12 and a resin outer member 94 are connected by a main rubber elastic body 16.

[0093] As shown in Figure 13, the resin outer member 94 of the subframe mount 90 has a structure in which the small diameter portions 36, 36 are removed from the resin outer member 14 of the subframe mount 10 in the first embodiment. Therefore, when the resin outer member 94 is fitted into the collar member 92, the part of the inner circumferential surface of the collar member 92 that is fitted to the front end, beyond the window portions 98, 98 (described later), is a cylindrical fitting surface 96 that extends continuously around the entire circumference.

[0094] The color member 92 is provided with a pair of window portions 98, 98 on both sides in the front-rear direction. As shown in Figure 12, the window portions 98 are through holes that penetrate radially through the peripheral wall of the color member 92 with a roughly U-shaped cross-sectional shape, and the vertical length dimensions on both sides in the circumferential direction are larger than the vertical length dimension of the central part in the circumferential direction. As a result, the color member 92 is provided with a protruding piece 100 that extends toward the window portion 98 at the central part in the circumferential direction of the window portion 98. The protruding piece 100 is roughly the shape of a rounded rectangular plate, and the protruding tip constitutes a part of the upper edge of the window portion 98.

[0095] The protruding tip portion (lower end portion) of the protruding piece 100 is an inclined portion 102 that slopes outward toward the outer circumference toward the protruding tip, as shown in Figures 13 and 14. The inclined portion 102 extends linearly at a substantially constant inclination angle in the vertical cross-section shown in Figure 13, but the inclination angle may change gradually or in steps, for example, so that the inclination angle in the vertical direction increases toward the protruding tip. The base portion 104 of the protruding piece 100 on the protruding base end side (upper side) of the inclined portion 102 is not inclined toward the vertical direction.

[0096] Thus, the protruding tip portion of the protruding piece 100 in the color member 92 is an inclined portion 102 that slopes outward toward the protruding tip. As a result, the window portion 98 side of the fitting surface 96, which is provided on the fitting tip side of the window portion 98, is a relief portion located outward from the fitting surface 96. In this embodiment, the relief portion is composed of an inclined portion 102 that slopes outward toward the outer circumference as it goes toward the fitting base end side (downward side). When the subframe mount 90 is fitted into the color member 92, the inclined portion 102 is separated from the outer surface of the resin outer member 94, which prevents damage (scratches and abrasions) to the resin outer member 94 caused by the inner circumferential edge of the protruding tip of the protruding piece 100 being pressed against the resin outer member 94.

[0097] The inclined portion 102 of the protruding piece 100 has its maximum protrusion outward relative to the fitting surface 96 at its lower end, and it is desirable that the maximum protrusion amount d of the inner surface of the inclined portion 102 outward relative to the fitting surface 96 is 0.1 mm or more. Preferably, the maximum protrusion amount d of the inner surface of the inclined portion 102 outward relative to the fitting surface 96 is 0.5 mm or more, and more preferably 1.0 mm or more. As a result, when the subframe mount 90 is press-fitted into the collar member 92, the inner edge of the protruding tip of the protruding piece 100 separates from the resin outer member 94 outward, thus avoiding abrasion of the resin outer member 94 caused by contact between the inner edge of the protruding tip of the protruding piece 100 and the resin outer member 94.

[0098] The corner portion 106 formed by the inclined portion 102 and the base portion 104 on the inner circumferential surface of the protruding piece 100 is an obtuse angle (less than 180 degrees) with an angle θ greater than 90 degrees, so that the inclination angle (180-θ) of the inclined portion 102 with respect to the press-fitting direction (up and down direction) of the subframe mount 90 into the collar member 92 is smaller than 90 degrees. The angle θ of the corner portion 106 formed by the inclined portion 102 and the base portion 104 is preferably 120 degrees or more, and more preferably 150 degrees or more. As a result, even if the corner portion 106 formed by the inclined portion 102 and the base portion 104 on the inner circumferential surface of the protruding piece 100 is pressed against the resin outer member 94 when the subframe mount 90 is press-fitted into the collar member 92, the resin outer member 94 is less likely to be scraped by the corner portion 106. Furthermore, the angle θ of the corner 106 formed by the inclined portion 102 and the base portion 104 is less than 180 degrees, preferably 175 degrees or less, more preferably 170 degrees or less, and even more preferably 160 degrees or less. This makes it easier to position the protruding tip of the inclined portion 102 on the outer circumference side of the fitting surface 96, and effectively prevents the protruding tip of the inclined portion 102 from contacting the outer circumference surface of the resin outer member 94. Note that in the state shown in Figure 13, where the subframe mount 90 is press-fitted into the collar member 92, the corner 106 formed by the inclined portion 102 and the base portion 104 is located above the retaining projection 24 of the resin outer member 94. Therefore, the corner 106 does not come into contact with the retaining projection 24 during press-fitting, and the retaining projection 24 is not worn down by contact with the corner 106.

[0099] As described above, in this embodiment, the protruding piece 100 that constitutes the upper edge portion of the window portion 98 of the color member 92 is inclined outward at the inclined portion 102 and is separated outward from the resin outer member 94 of the subframe mount 90, thereby forming a relief portion that prevents the resin outer member 94 from being scraped when the subframe mount 90 is pressed into the resin outer member 94. The relief portion only needs to be provided on at least one of the resin outer member and the color member, and may be provided on the resin outer member as in the first to third embodiments, or on the color member as in the fourth embodiment. Furthermore, for example, it is also possible to use a combination of the relief portion on the resin outer member side shown in the first to third embodiments and the relief portion on the color member side shown in the fourth embodiment.

[0100] Although embodiments of the present invention have been described in detail above, the present invention is not limited by its specific description. For example, in the first embodiment, an example was shown in which the retaining projection 24 and the window portion 50 are formed on both sides in the radial direction, but the number of retaining projections 24 and window portions 50 is not limited to two; there may be one of each, or three or more of each. Furthermore, when multiple retaining projections 24 and window portions 50 are provided, it is desirable that they be evenly distributed in the circumferential direction, but the arrangement in the circumferential direction is not limited as long as the retaining projections 24 and window portions 50 are provided in positions corresponding to each other.

[0101] Furthermore, multiple sets of retaining projections 24 and window portions 50 may be provided at mutually different positions in the axial direction. Moreover, when multiple sets of retaining projections 24 and window portions 50 are provided in the circumferential direction, the axial positions of these multiple sets of retaining projections 24 and window portions 50 provided at different positions in the circumferential direction may be mutually different.

[0102] The shape of the retaining projection when viewed in the direction of protrusion is not necessarily limited to a square or rectangle, but may be a quadrilateral such as a trapezoid or parallelogram, or a triangle, a polygon with pentagons or more, or a circle including an oval. Similarly, the opening shape of the window is not necessarily limited to a square or rectangle, and various shapes can be used, just like the retaining projection. It is desirable that the retaining projection and the window that engages with the retaining projection have corresponding shapes when viewed in the direction of protrusion of the retaining projection 24, but they may have different shapes.

[0103] The guide surface 30 of the retaining projection 24 is not essential. For example, if an expanding tapered surface is formed on the inner circumferential surface of the opening portion of the collar member 46 into which the resin outer member 14 is fitted, even if the retaining projection 24 does not have a guide surface 30, the retaining projection 24 will be able to easily overcome the collar member 46 when the resin outer member 14 is fitted into the collar member 46. The tip surface 34 of the retaining projection 24 is not required, and for example, the guide surface 30 and the locking surface 32 may be provided directly and continuously without an intervening tip surface 34.

[0104] The axial length of the retaining projection 24 may be greater than the axial length of the window portion 50. In this case, a portion of the locking surface 32 of the retaining projection 24 may be positioned axially away from the window portion 50, thereby forming an axial gap 60.

[0105] The relief portion is not necessarily limited to being composed of a small-diameter portion 36 which reduces the outer diameter of the resin outer member 14. Specifically, for example, the relief portion may be in the shape of a notch that penetrates the resin outer member 14 in the radial direction. Furthermore, the relief portion can be composed of a combination of a recess shape and a notch shape; for example, a partial notch may be provided at the insertion tip of the small-diameter portion 36. The relief portion may be configured in such a way that it reduces or eliminates the contact force between the first inner peripheral edge 56 and the resin outer member 14 on the movement path, so as to reduce abrasion of the first inner peripheral edge 56 of the window portion 50 against the outer peripheral surface of the resin outer member 14 when the resin outer member is fitted into the collar member. For example, in order to reduce or eliminate the amount of radial press-fitting between the first inner peripheral edge 56 and the resin outer member 14 along such a movement path (radial forced fitting dimension), the inner diameter dimension (first inner peripheral edge 56) or outer diameter dimension (resin outer member 14) of the first inner peripheral edge 56 and the resin outer member 14 can be partially made different in a direction that allows them to move away from each other radially, thereby forming a relief portion (inner circumferential relief portion or outer circumferential relief portion) on at least one of the first inner peripheral edge 56 and the resin outer member 14.

[0106] The small-diameter portion does not necessarily have a tapered surface 40 (78) on which the outer diameter of the resin outer member 14 gradually changes; for example, it may have a shape on which the outer diameter of the resin outer member 14 changes in steps. Also, the small-diameter portion may be composed entirely of a tapered surface 40 (78) in the axial direction and may not have a cylindrical surface 38 as in the first embodiment or a flat surface 76 as in the second embodiment, and its depth may change gradually in the axial direction.

[0107] The relief portion only needs to reduce the abrasion of the resin outer member 14 by the first inner peripheral edge 56 of the window portion 50, and is not necessarily limited to completely avoiding contact between the first inner peripheral edge 56 and the resin outer member 14. Specifically, for example, even if the circumferential width of the relief portion is sufficiently narrower than that of the window portion 50, the portion where the relief portion is formed can be expected to suppress abrasion of the resin outer member 14 by the first inner peripheral edge 56. Therefore, the circumferential width dimension of the relief portion is not particularly limited, and the circumferential position of the relief portion may be offset circumferentially from the circumferential center of the retaining projection 24 and the window portion 50, as long as it is in a circumferential position corresponding to the retaining projection 24 and the window portion 50.

[0108] In the fourth embodiment, the protruding piece 100 was in the shape of a roughly rounded rectangular plate, but the protruding piece may have other shapes. Specifically, for example, it may be in the shape of a semicircular plate, or its thickness may change in the direction of protrusion. Also, for example, the inclined portion and the base portion may be smoothly curved and continuous without forming corners at least on the inner circumferential surface. Furthermore, the relief portion provided on the collar member does not necessarily have to be inclined as a whole with respect to the insertion direction; for example, only the end on the insertion tip side (base side) may be inclined, and the insertion base end side (protruding tip side) may be non-inclined. Also, when an inclined relief portion is provided on the inner circumferential surface of the collar member, the outer circumferential surface of the relief portion may be non-inclined.

[0109] In the first to fourth embodiments described above, subframe mounts 10, 70, and 90 were shown as examples of cylindrical vibration damping devices. However, the cylindrical vibration damping device according to the present invention is not limited to subframe mounts, but is also suitably applied to, for example, engine mounts, motor mounts, torque rods, suspension bushings, and the like.

[0110] 10 Subframe mount (Cylindrical vibration damping device of the first embodiment) 12 Inner shaft member 14 Resin outer member 16 Main rubber elastic body 18 Cylindrical part 20 Flange-shaped part 22 Press-fit guide surface 24 Removal projection 30 Guide surface 32 Locking surface 34 Tip surface 36 Small diameter part (relief part) 38 Cylindrical surface 40 Tapered surface 42 First stopper part 44 Second stopper part 46 Collar member 48 Mounting hole 50 Window part 56 First inner peripheral edge part (edge) 58 Second inner peripheral edge part 60 Axial gap 62 Circumferential gap 64 Gap 66 Fitting surface 70 Subframe mount (Cylindrical vibration damping device of the second embodiment) 72 Resin outer member 74 Small diameter part (relief part) 76 Flat surface 78 Tapered surface 80 Collar member (third embodiment) 82 First inner peripheral edge (relief portion) 90 Subframe mount (fourth embodiment cylindrical vibration isolation device) 92 Collar member 94 Resin outer member 96 Fitting surface 98 Window portion 100 Projection piece 102 Inclined portion (relief portion) 104 Base portion 106 Corner portion W1 Circumferential width dimension of small diameter portion W2 Circumferential width dimension of retaining projection portion W3 Circumferential width dimension of window portion D Maximum depth dimension of small diameter portion T Radial thickness dimension of cylindrical portion L1 Axial distance from the upper end of the collar member to the lower end of the small diameter portion L2 Axial distance from the upper end of the collar member to the first inner peripheral edge portion of the window portion L3 Axial length dimension of the window portion L4 Axial length dimension from the upper end of the retaining projection portion to the lower end of the press-fit guide surface d Maximum projection amount of the projection piece to the outer circumference relative to the fitting surface θ Angle between the inclined portion and the base portion on the inner circumferential surface of the projection piece

Claims

1. A cylindrical vibration damping device in which an inner shaft member is inserted through a cylindrical resin outer member, and the inner shaft member and the resin outer member are connected by a main rubber elastic body, wherein the resin outer member is provided with a retaining projection that protrudes from its outer circumference and is inserted into a window provided in a metal collar member, and a relief portion is provided on at least one of the leading edge portion of the resin outer member that fits into the collar member and the leading edge portion on the window side of the fitting surface of the collar member that is fitted onto the resin outer member on the leading edge side of the window.

2. The cylindrical vibration damping device according to claim 1, wherein the leading edge portion of the resin outer member that fits into the collar member is provided with the relief portion relative to the collar member, and the relief portion is positioned on the fitting end side at a circumferentially corresponding position to the retaining projection.

3. The cylindrical vibration damping device according to claim 2, wherein the relief portion is a small-diameter portion in which the outer diameter is partially reduced.

4. The cylindrical vibration damping device according to claim 3, wherein the outer surface of the resin outer member in the small diameter portion has a tapered surface that inclins toward the outer circumference as it moves toward the retaining projection in the portion close to the retaining projection in the axial direction.

5. The cylindrical vibration damping device according to any one of claims 2 to 4, wherein the relief portion extends to the fitted tip of the resin outer member.

6. The cylindrical vibration damping device according to any one of claims 2 to 5, wherein the collar member into which the resin outer member is fitted has a chamfered inner peripheral edge of the window portion located on the fitting tip side of the retaining projection.

7. The cylindrical vibration damping device according to any one of claims 1 to 6, wherein the relief portion for the resin outer member is provided on the edge of the fitting surface of the collar member that is fitted onto the resin outer member on the fitting tip side of the window portion, and the relief portion is inclined toward the outer circumference toward the fitting base end side.

8. The cylindrical vibration damping device according to claim 7, wherein the inner circumferential surface of the relief portion has a maximum protrusion of 0.1 mm or more from the outer circumference of the collar member relative to the fitting surface.

9. The cylindrical vibration isolation device according to any one of claims 1 to 8, wherein the circumferential width dimension of the relief portion is 50% or more of the circumferential width dimension of the retaining projection portion.

10. The cylindrical vibration damping device according to claim 9, wherein the circumferential width dimension of the relief portion is larger than the circumferential width dimension of the retaining projection, and the relief portion extends beyond the retaining projection to both outer sides.

11. The cylindrical vibration damping device according to any one of claims 1 to 10, wherein a pair of retaining projections are provided on both radial sides of the resin outer member, and a pair of relief portions are provided on the resin outer member at circumferential positions corresponding to the pair of retaining projections.

Images