JP7524043B2 - Strut mount - Google Patents

Description

The present invention relates to a strut mount, and in particular to a strut mount that can increase the static spring constant during large amplitude vibration while decreasing the dynamic spring constant during small amplitude vibration in a vibration-isolating base in which each part is made of the same elastic body.

In the suspension mechanism of vehicles such as automobiles, the rod tip of the shock absorber is elastically connected to the vehicle body via a strut mount, thereby preventing vibrations from the wheel side from being transmitted to the vehicle body. For example, the strut mount disclosed in Patent Document 1 has a flange that projects radially outward from a cylindrical inner member to which the rod tip is attached, and an annular vibration-proof base made of elastic material that covers both sides of the flange is sandwiched between a pair of stoppers on an outer member that is attached to the vehicle body.

Furthermore, this strut mount has a vibration-isolating base formed by overlapping urethane on a portion of the circumference of the annular rubber. This increases the static spring constant during large amplitude vibrations (large input forces) to ensure steering stability, while lowering the dynamic spring constant during small amplitude vibrations to suppress the transmission of vibrations from the wheel side to the vehicle body side.

JP 2010-90995 A

However, in the technology disclosed in Patent Document 1, the vibration-isolating base is constructed from two different types of elastic bodies, which increases the number of parts and manufacturing steps of the vibration-isolating base, and also increases the risk of fatigue due to contact friction between the different elastic bodies.

The present invention was made to solve the above-mentioned problems, and aims to provide a strut mount that can increase the static spring constant during large amplitude vibration while decreasing the dynamic spring constant during small amplitude vibration in a vibration-isolating base in which each part is composed of the same elastic body.

To achieve this objective, the strut mount of the present invention comprises an inner member attached to the tip of the rod of a shock absorber, an outer member that surrounds the outer periphery of the inner member and is attached to the vehicle body, and an annular vibration-proof base that is interposed between the inner member and the outer member and is composed of the same elastic body in each part. One of the inner member or the outer member has a pair of stopper surface parts that sandwich the vibration-proof base in the circumferential direction in the opposing direction, and the other of the inner member or the outer member has a plate part that is sandwiched between the pair of stopper surface parts via the vibration-proof base. The vibration-proof base has a plurality of first and second protrusions that protrude from the plate part side to the stopper surface part side and are distributed in the circumferential direction. The first protrusions are pre-compressed between the plate part and the stopper surface part, and there is a gap of 0.05 to 0.5 mm between the second protrusions and the stopper surface part.

The strut mount of the present invention comprises an inner member attached to the rod tip of a shock absorber, an outer member surrounding the outer periphery of the inner member and attached to the vehicle body, and an annular vibration-proof base interposed between the inner member and the outer member and each part made of the same elastic body, wherein one of the inner member or the outer member comprises a pair of stopper surface parts that sandwich the vibration-proof base in the circumferential direction in the opposing direction, and the other of the inner member or the outer member comprises a plate part sandwiched between the pair of stopper surface parts via the vibration-proof base, and the vibration-proof base comprises a plurality of first and second protrusions that protrude from the plate part side to the stopper surface part side and are distributed in the circumferential direction, and the first and second protrusions are pre-compressed between the plate part and the stopper surface part, and the pre-compression amount of the second protrusion is less than the pre-compression amount of the first protrusion.

According to the strut mount of claim 1, the annular vibration-isolating base, each part of which is made of the same elastic body, has a plurality of first and second protrusions that protrude from the plate part side to the stopper surface part side and are distributed in the circumferential direction. Since the first protrusions are pre-compressed between the plate part and the stopper surface part, the distance between the plate part and the stopper surface part is stabilized. Since there is a gap of 0.05 to 0.5 mm between the second protrusions and the stopper surface part, when vibrations with an amplitude smaller than this gap are input to the vibration-isolating base (hereinafter referred to as "small amplitude vibration"), the second protrusions do not come into contact with the stopper surface part, and the dynamic spring constant of the vibration-isolating base can be reduced.

On the other hand, when vibrations with an amplitude equal to or greater than the gap between the second protrusion and the stopper surface are input to the vibration-isolating base (hereinafter referred to as "large amplitude vibration"), the second protrusion comes into contact with the stopper surface, and the static spring constant of the vibration-isolating base can be increased. As a result, in a vibration-isolating base in which each part is made of the same elastic body, it is possible to increase the static spring constant during large amplitude vibration while decreasing the dynamic spring constant during small amplitude vibration, i.e., the static-dynamic ratio of the vibration-isolating base can be reduced.

Furthermore, when large amplitude vibrations with amplitudes less than twice the gap between the second protrusion and the stopper surface are input to the vibration-isolating base (hereinafter referred to as "medium amplitude vibrations"), the amount of compression of the second protrusion that comes into contact with the stopper surface is small, so the static spring constant and dynamic spring constant during medium amplitude vibrations can be kept low. This makes it difficult for shocks and vibrations during medium amplitude vibrations to be transmitted from the strut mount to the vehicle body.
The circumferential dimension of the base end of the first protrusion on the plate side is smaller than the circumferential dimension of the base end of the second protrusion on the plate side, thereby making it possible to further reduce the dynamic spring constant of the vibration-isolating base during small amplitude vibration and to further increase the static spring constant of the vibration-isolating base during large amplitude vibration.

According to the strut mount of claim 2, the annular vibration-proof base, each part of which is made of the same elastic body, has a plurality of first and second protrusions that protrude from the plate part side to the stopper surface part side and are distributed in the circumferential direction. Since the first and second protrusions are precompressed between the plate part and the stopper surface part, the distance between the plate part and the stopper surface part is stabilized. The precompression amount of the second protrusion is less than the precompression amount of the first protrusion. As a result, when a vibration of a relatively small amplitude is input to the vibration-proof base (hereinafter referred to as "when there is a small amplitude vibration"), the compression amount of the first and second protrusions is almost the same as the precompression amount. Therefore, when there is a small amplitude vibration, the characteristics of the first protrusion, which has a large amount of precompression, become dominant and determine the dynamic spring constant of the vibration-proof base, and the dynamic spring constant of the vibration-proof base can be reduced.

On the other hand, when a vibration of a relatively large amplitude is input to the vibration-isolating base (hereinafter referred to as "during large amplitude vibration"), the compression amount of not only the first protrusion but also the second protrusion increases, and the static spring constants of both the first protrusion and the second protrusion can be increased, thereby increasing the static spring constant of the vibration-isolating base. As a result, in a vibration-isolating base in which each part is composed of the same elastic body, it is possible to increase the static spring constant during large amplitude vibration while decreasing the dynamic spring constant during small amplitude vibration, i.e., it is possible to reduce the static-dynamic ratio of the vibration-isolating base.
According to the strut mount of claim 3, as with the strut mount of claim 1, there is a gap of 0.05 to 0.5 mm between the second protrusion and the stopper surface portion, so that the dynamic spring constant of the vibration-isolating base can be lowered during small amplitude vibration while the static spring constant of the vibration-isolating base can be increased during large amplitude vibration, and the static spring constant and dynamic spring constant can be kept low during medium amplitude vibration.
The radial dimension of the base end of the first protrusion on the plate side is smaller than the radial dimension of the base end of the second protrusion on the plate side. This makes it easier to reduce the contact area between the first protrusion and the stopper surface and to increase the contact area between the second protrusion and the stopper surface. As a result, the dynamic spring constant during small amplitude vibration, in which the characteristics of the first protrusion dominate, can be further reduced, and the static spring constant during large amplitude vibration, in which the characteristics of the second protrusion as well as the characteristics of the first protrusion have a large effect, can be further increased.

According to the strut mount of claim 4 , the radial dimension of the first protrusion decreases toward the tip on the stopper surface side. This makes it possible to increase the contact area between the first protrusion and the stopper surface during large amplitude vibration, while decreasing the contact area between the first protrusion and the stopper surface during small amplitude vibration. Therefore, in addition to the effects of any of claims 1 to 3 , it is possible to increase the static spring constant during large amplitude vibration, while decreasing the dynamic spring constant during small amplitude vibration.

According to the strut mount of claim 5 , the first protrusion and the second protrusion are separated in the circumferential direction, so that the stress when the first protrusion and the second protrusion are compressed can be dispersed, making it difficult for the vibration-isolating base to crack, etc. Furthermore, because deformation of the second protrusion accompanying deformation of the first protrusion can be suppressed, in addition to the effects of any of claims 1 to 4 , the increase in the static spring constant according to the amount of compression of the second protrusion can be stabilized, and the static spring constant of the vibration-isolating base according to the input vibration can be stabilized.

FIG. 2 is a cross-sectional view of the strut mount according to the first embodiment. FIG. 2 is a plan view of the vibration-isolating base and the inner member. 3 is a cut-away end view of the vibration-isolating base and the inner member taken along line III-III in FIG. 2. FIG. 11 is a cross-sectional view of a strut mount according to a second embodiment.

Preferred embodiments will now be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of a strut mount 10 in a first embodiment. The strut mount 10 is an anti-vibration device that is installed between a shock absorber rod (not shown) and the vehicle body (not shown) in an automobile suspension mechanism (suspension mechanism, not shown) to reduce vibrations transmitted from the wheel side to the vehicle body side.

The strut mount 10 comprises a cylindrical inner member 11 to which the tip of the shock absorber rod is fastened, an outer member 14 which is fastened to the vehicle body, and a vibration-isolating base 30 which connects the inner member 11 and the outer member 14. Note that the cross-sectional view of the strut mount 10 in Figure 1 shows a cross section including the axis C of the inner member 11 (the axis of the shock absorber rod).

The inner member 11 is a cylindrical member made of a metal such as steel or aluminum alloy, and has an annular plate portion 12 that extends radially outward from the upper end. The plate portion 12 is a flat plate perpendicular to the axis C. The tip of the shock absorber rod is inserted into the inner periphery of the inner member 11 and fastened to the rod tip, thereby attaching the inner member 11 to the rod tip.

The vibration-isolating base 30 is an annular member made of the same elastic material so as to cover the upper, lower and outer peripheral surfaces of the plate portion 12. In this embodiment, the elastic material is rubber, but the elastic material may be made of a thermoplastic elastomer, a foamed synthetic resin or the like. The vibration-isolating base 30 is vulcanization-bonded to the plate portion 12.

The outer member 14 includes a tube wall portion 15 on whose inner circumferential side the vibration-isolating base 30 is housed, a lower wall portion 16 that protrudes radially inward from the lower end of the tube wall portion 15, a cylindrical retaining portion 17 that extends from the lower end of the tube wall portion 15 below the lower wall portion 16, a fixing portion 18 that protrudes radially outward from a portion of the circumference of the tube wall portion 15, and a cover body 19 made of a metal such as steel that covers the upper end of the tube wall portion 15. The tube wall portion 15, the lower wall portion 16, the retaining portion 17, and the fixing portion 18 are integrally formed from a metal such as steel.

The tube wall portion 15 is a cylindrical portion centered on the axis C, and the inner peripheral surface 15a restricts the radial movement of the vibration-isolating base 30. At the upper end of the tube wall portion 15, an opening 15b is formed by recessing the inner peripheral surface 15a in a stepped shape. After the vibration-isolating base 30 is housed inside the tube wall portion 15, the lid body 19 is fitted into this opening 15b, and the lid body 19 and the tube wall portion 15 are welded or fused together, thereby fixing the lid body 19 to the tube wall portion 15.

The lower wall portion 16 is an annular portion centered on the axis C, and supports the vibration-isolating base 30 from below. A part of the inner member 11 passes along the inner periphery of the lower wall portion 16. The lower wall portion 16 has an annular stopper surface portion 16a that faces the plate portion 12 of the inner member 11 in the vertical direction (the direction of the axis C) with the vibration-isolating base 30 sandwiched therebetween.

The holding portion 17 is a cup-shaped portion to which a bound bumper (not shown) that acts as a stopper when the shock absorber is compressed is attached. The fixing portion 18 is a portion that is attached to the vehicle body by bolts or the like.

When the lid 19 is fixed to the tube wall 15, it is the part that holds the vibration-isolating base 30 by sandwiching it between the stopper surface 16a of the bottom wall 16. The part of the lid 19 that faces the stopper surface 16a in the vertical direction is the annular stopper surface 19a. Therefore, the stopper surfaces 16a and 19a sandwich the vibration-isolating base 30 in the vertical direction (opposing direction), and sandwich the plate portion 12 of the inner member 11 in the vertical direction via the vibration-isolating base 30.

Next, the detailed configuration of the vibration-isolating base 30 will be described with reference to Figures 2 and 3 in addition to Figure 1. Figure 2 is a plan view of the vibration-isolating base 30 and the inner member 11. Figure 3 is a cut-away end view of the vibration-isolating base 30 and the inner member 11 taken along line III-III in Figure 2.

As shown in Figures 1 and 2, the vibration-isolating base 30 comprises an annular base 30a of a predetermined thickness that covers the upper, lower and outer peripheral surfaces of the plate portion 12, and a plurality of first protrusions 31 and second protrusions 32 that protrude from the base 30a (on the plate portion 12 side) toward the stopper surface portions 16a and 19a, respectively. The base 30a, the plurality of first protrusions 31 and the second protrusions 32 are integrally molded from the same elastic body.

The multiple first protrusions 31 and second protrusions 32 are distributed around the circumferential direction of the vibration-proof base 30. Specifically, the first protrusions 31 and the second protrusions 32 are arranged alternately around the circumferential direction, and three each of the first protrusions 31 and the second protrusions 32 are arranged rotationally symmetrically on one side of the plate portion 12. The first protrusions 31 and the second protrusions 32 are also located at the same position on the upper and lower sides of the plate portion 12. Note that the positions of the first protrusions 31 and the second protrusions 32 may be shifted between the upper and lower sides of the plate portion 12, for example, so that the second protrusions 32 are located on the opposite side of the plate portion 12 to the first protrusions 31.

The first protrusions 31 are formed at a height that allows them to be pre-compressed between the plate portion 12 and the stopper surface portions 16a, 19a. In FIG. 1, the first protrusions 31 before pre-compression are shown by two-dot chain lines, and the pre-compressed first protrusions 31 are shown by solid lines. The difference in height of the first protrusions 31 before and after pre-compression is the amount of pre-compression. The first protrusions 31, which are distributed in the circumferential direction, are pre-compressed between the plate portion 12 and the stopper surface portions 16a, 19a, so that the distance between the plate portion 12 and the stopper surface portions 16a, 19a sandwiching the vibration-isolating base 30 is stable.

The first protrusion 31 has a radial dimension that gradually decreases from the base end on the base 30a side (plate portion 12 side) toward the tip end on the stopper surface portions 16a, 19a side, and the axial cross section (cross section in FIG. 1) is formed in a substantially triangular shape. As shown in FIG. 3, the first protrusion 31 has a circumferential dimension that gradually decreases from the base end toward the tip end, and the circumferential cross section (cross section in FIG. 3) is also formed in a substantially triangular shape.

As shown in FIG. 1, the second protrusion 32 is formed at a height that does not contact the stopper surface portions 16a, 19a when the vibration-isolating base 30 is not subjected to vibration and the load of the vehicle body is applied to the resting state. In the resting state, the minimum gap G between the second protrusion 32 and the stopper surface portions 16a, 19a is 0.05 to 0.5 mm.

The radial dimension of the second protrusion 32 gradually decreases from the base end on the base 30a side to the tip on the stopper surface portions 16a, 19a side, and the axial cross section (cross section in FIG. 1) is formed to be approximately trapezoidal. The tip of the second protrusion 32 is formed by a substantially flat surface with a slightly raised radial center. Also, as shown in FIG. 3, the tip of the second protrusion 32 is approximately parallel to the plate portion 12 at the circumferential end face (the height is approximately constant in the circumferential direction).

As shown in Figures 2 and 3, the first protrusion 31 and the second protrusion 32 are separated in the circumferential direction. The top and bottom surfaces of the base 30a are exposed by the bottom surface of the recess 33 between the first protrusion 31 and the second protrusion 32. The thickness from the plate portion 12 to the bottom surface of the recess 33 is the thickness of the annular base 30a, and the height from the bottom surface of the recess 33 is the height of the first protrusion 31 and the second protrusion 32. In addition, the boundary portion of the thickness from the plate portion 12 to the bottom surface of the recess 33 with the base 30a is the base end of the first protrusion 31 and the second protrusion 32.

The radial dimension L1 of the base end of the first protrusion 31 is smaller than the radial dimension L2 of the base end of the second protrusion 32. In addition, the circumferential dimension L3 of the base end of the first protrusion 31 is smaller than the circumferential dimension L4 of the base end of the second protrusion 32.

According to the strut mount 10 described above, the first protrusion 31 is pre-compressed between the plate portion 12 and the stopper surface portions 16a, 19a, while in a stationary state, there is a gap G of 0.05 to 0.5 mm between the second protrusion 32 and the stopper surface portions 16a, 19a. Therefore, when vibrations with an amplitude smaller than this gap G are input to the vibration-isolating base 30 (hereinafter referred to as "small amplitude vibration"), the second protrusion 32 does not come into contact with the stopper surface portions 16a, 19a, and the dynamic spring constant of the vibration-isolating base 30 is determined by the characteristics of the first protrusion 31. Therefore, the dynamic spring constant of the vibration-isolating base 30 during small amplitude vibration can be reduced, thereby suppressing the transmission of vibration from the wheel side to the vehicle body side.

On the other hand, when vibrations of an amplitude equal to or greater than the gap G between the second protrusion 32 and the stopper surface portions 16a, 19a are input to the vibration-isolating base 30 (hereinafter referred to as "large amplitude vibration"), not only the first protrusion 31 but also the second protrusion 32 hits the stopper surface portions 16a, 19a. Therefore, the static spring constant of the vibration-isolating base 30 during large amplitude vibration can be increased, and the handling stability of the vehicle using the strut mount 10 can be ensured. As a result, the static spring constant during large amplitude vibration can be increased in the vibration-isolating base 30, each of which is composed of the same elastic body, while the dynamic spring constant during small amplitude vibration can be reduced. In other words, the static-dynamic ratio of the vibration-isolating base 30 can be reduced, and both the suppression of vibration transmission to the vehicle body and handling stability can be achieved.

Furthermore, when large amplitude vibrations with an amplitude (1 mm or less) of less than twice the gap G between the second protrusion 32 and the stopper surface portions 16a, 19a are input to the vibration-proof base 30 (hereinafter referred to as "medium amplitude vibrations"), the amount of compression of the second protrusion 32 that hits the stopper surface portions 16a, 19a is small. This allows the static spring constant and dynamic spring constant of the vibration-proof base 30 to be kept low during medium amplitude vibrations, making it difficult for shocks and vibrations during medium amplitude vibrations to be transmitted from the strut mount 10 to the vehicle body.

The radial dimension of the first protrusion 31 decreases toward the tip, so that the contact area between the first protrusion 31 and the stopper surface portions 16a, 19a during large amplitude vibration can be increased while the contact area between the first protrusion 31 and the stopper surface portions 16a, 19a during small amplitude vibration can be reduced. This allows the static spring constant of the vibration-isolating base 30 to be increased during large amplitude vibration while the dynamic spring constant of the vibration-isolating base 30 to be decreased during small amplitude vibration.

The tip of the second protrusion 32 is a substantially flat surface, and the height of the second protrusion 32 in the circumferential cross section is substantially constant. This allows the static spring constant of the vibration-isolating base 30 to increase rapidly during large amplitude vibration when the second protrusion 32 comes into contact with the stopper surface portions 16a, 19a. This improves the handling stability of a vehicle using the strut mount 10.

However, since the generally flat surface at the tip of the second protrusion 32 is slightly raised in the radial center (the radial dimension of the tip of the second protrusion 32 becomes smaller toward the very tip), the static spring constant of the vibration-isolating base 30 can be increased gradually in the initial stage of contact between the second protrusion 32 and the stopper surface portions 16a, 19a. This makes it difficult for the impact generated when the second protrusion 32 comes into contact with the stopper surface portions 16a, 19a to be transmitted to the vehicle body.

The first protrusion 31 and the second protrusion 32 are separated in the circumferential direction, and the recess 33 is provided between them, so that the stress generated when the first protrusion 31 and the second protrusion 32 are compressed can be dispersed by the recess 33, making it difficult for cracks to occur in the vibration-proof base 30. Furthermore, the deformation of the second protrusion 32 accompanying the deformation of the first protrusion 31 can be suppressed by the recess 33, so that the size of the gap G between the second protrusion 32 and the stopper surface portions 16a, 19a during small amplitude vibration and the increase in the static spring constant of the vibration-proof base 30 according to the amount of compression of the second protrusion 32 during large amplitude vibration can be stabilized.

The radial dimension L1 of the base end of the first protrusion 31 is smaller than the radial dimension L2 of the base end of the second protrusion 32. This makes it easier to reduce the contact area between the first protrusion 31 and the stopper surface portions 16a, 19a, and therefore the dynamic spring constant of the vibration-proof base 30 during small amplitude vibration, when the characteristics of the first protrusion 31 are dominant, can be further reduced. Furthermore, since the radial dimension L2 is larger than the radial dimension L1, it is easier to increase the contact area between the second protrusion 32 and the stopper surface portions 16a, 19a, and therefore the static spring constant of the vibration-proof base 30 during large amplitude vibration, when not only the characteristics of the first protrusion 31 but also the characteristics of the second protrusion 32 have a large effect, can be further increased.

Similarly, the circumferential dimension L3 of the base end of the first protrusion 31 is smaller than the circumferential dimension L4 of the base end of the second protrusion 32, so that the dynamic spring constant of the vibration-isolating base 30 during small amplitude vibration can be further reduced, and the static spring constant of the vibration-isolating base 30 during large amplitude vibration can be further increased. As a result, the strut mount 10 can further suppress the transmission of vibration to the vehicle body, and can further improve steering stability.

Next, the second embodiment will be described with reference to FIG. 4. In the first embodiment, a case where there is a gap G between the second protrusion 32 and the stopper surface portions 16a, 19a in a stationary state is described. In contrast, in the second embodiment, a case where the second protrusion 42 abuts against the stopper surface portions 16a, 19a even in a stationary state is described. Note that the same parts as in the first embodiment are given the same reference numerals and the following description will be omitted. FIG. 4 is a cross-sectional view of a strut mount 40 in the second embodiment.

The vibration-isolating base 41 of the strut mount 40 comprises a base 30a of a predetermined thickness that covers the upper, lower and outer peripheral surfaces of the plate portion 12, and a plurality of first protrusions 31 and second protrusions 42 that protrude from the base 30a (on the plate portion 12 side) toward the stopper surface portions 16a and 19a, respectively. The base 30a, the plurality of first protrusions 31 and the second protrusions 42 are integrally molded from the same elastic body (e.g. rubber).

The positional relationship between the multiple first protrusions 31 and the second protrusions 42 is the same as the positional relationship between the multiple first protrusions 31 and the second protrusions 32 in the first embodiment. The second protrusions 42 are different from the second protrusions 32 in the first embodiment only in height, but are substantially the same in shape, radial dimension L2, and circumferential dimension L4 as the second protrusions 32.

The second protrusion 42 is formed at a height that allows it to be pre-compressed between the plate portion 12 and the stopper surface portions 16a, 19a. In FIG. 4, the second protrusion 42 before pre-compression is shown by a two-dot chain line, and the pre-compressed second protrusion 42 is shown by a solid line. The difference in height of the second protrusion 42 before and after pre-compression is the amount of pre-compression. Since the multiple first protrusions 31 and second protrusions 42 that are distributed in the circumferential direction are pre-compressed between the plate portion 12 and the stopper surface portions 16a, 19a, the distance between the plate portion 12 and the stopper surface portions 16a, 19a sandwiching the vibration-isolating base 41 is stabilized.

The height of the second protrusion 42 before pre-compression is lower than the height of the first protrusion 31 before pre-compression, so the amount of pre-compression of the second protrusion 42 is less than the amount of pre-compression of the first protrusion 31. As a result, when vibration of a relatively small amplitude (e.g., less than 0.5 mm) is input to the vibration-proof base 41 (hereinafter referred to as "small amplitude vibration"), the compression amount of the first protrusion 31 and the second protrusion 42 is almost the same as the amount of pre-compression. Therefore, during small amplitude vibration, the characteristics of the first protrusion 31, which has a large amount of pre-compression, become dominant and determine the dynamic spring constant of the vibration-proof base 41, and the dynamic spring constant of the vibration-proof base 41 can be reduced.

On the other hand, when vibrations of a relatively large amplitude (e.g., 0.5 mm or more) are input to the vibration-isolating base 41 (hereinafter referred to as "large amplitude vibration"), the compression amount of not only the first protrusion 31 but also the second protrusion 42 increases. Therefore, during large amplitude vibration, the static spring constants of both the first protrusion 31 and the second protrusion 42 can be increased, and the static spring constant of the vibration-isolating base 41 can be increased. As a result, in the vibration-isolating base 41, each part of which is composed of the same elastic body, it is possible to increase the static spring constant during large amplitude vibration while decreasing the dynamic spring constant during small amplitude vibration.

The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments, and it can be easily imagined that various improvements and modifications are possible within the scope of the present invention. The shapes and dimensions of the inner member 11, outer member 14, and vibration-isolating bases 30, 41 may be modified as appropriate. For example, a pair of annular stopper surface portions that sandwich the vibration-isolating bases 30, 41 in opposing directions may be provided on the inner member, and a plate portion that is sandwiched between the pair of stopper surface portions via the vibration-isolating bases 30, 41 may be provided on the outer member.

In the above embodiment, the first protrusion 31 and the second protrusions 32, 42 are separated in the circumferential direction, but this is not necessarily limited to this. The first protrusion 31 and the second protrusions 32, 42 may be continuous in the circumferential direction. In addition, the bottom surface of the recess 33 between the first protrusion 31 and the second protrusions 32, 42 is not limited to the base 30a, and the base 30a may be omitted so that the bottom surface of the recess 33 becomes the plate portion 12. In this case, the first protrusion 31 and the second protrusions 32, 42 protrude from the plate portion 12. Furthermore, in this case, the first protrusion 31 and the second protrusions 32, 42 may not be integrally molded, and the first protrusion 31 and the second protrusions 32, 42, which are separate bodies, may be made of the same (same type) elastic body.

In the above embodiment, the tip of the second protrusion 32, 42 is described as being substantially flat, but this is not necessarily limited to this. The tip of the second protrusion 32, 42 may be provided with a circumferentially extending protrusion or multiple projections and recesses, or the axial cross section of the tip may be V-shaped, inverted V-shaped, or broken line shaped. This can reduce the impact when the second protrusion 32, 42 comes into contact with the stopper surface 16a, 19a.

REFERENCE SIGNS LIST 10, 40 Strut mount 11 Inner member 12 Plate portion 14 Outer member 16a, 19a Stopper surface portion 30, 41 Vibration-isolating base 31 First protruding portion 32, 42 Second protruding portion

Claims (5)

A strut mount comprising: an inner member attached to a rod tip of a shock absorber; an outer member surrounding an outer periphery of the inner member and attached to a vehicle body; and an annular vibration-isolating base interposed between the inner member and the outer member, each portion of which is made of the same elastic body,
one of the inner member and the outer member includes a pair of stopper surface portions that sandwich the vibration-isolating base in a circumferential direction in opposing directions,
the other of the inner member and the outer member includes a plate portion sandwiched between a pair of the stopper surface portions via the vibration-isolating base,
the vibration-isolating base includes a plurality of first protruding portions and a plurality of second protruding portions that protrude from the plate portion side toward the stopper surface portion side and are distributed in a circumferential direction,
the first protrusion is pre-compressed between the plate portion and the stopper surface portion,
There is a gap of 0.05 to 0.5 mm between the second protrusion and the stopper surface,
A strut mount, characterized in that a circumferential dimension of a base end of the first protrusion on the plate portion side is smaller than a circumferential dimension of a base end of the second protrusion on the plate portion side . A strut mount comprising: an inner member attached to a rod tip of a shock absorber; an outer member surrounding an outer periphery of the inner member and attached to a vehicle body; and an annular vibration-isolating base interposed between the inner member and the outer member, each portion of which is made of the same elastic body,
one of the inner member and the outer member includes a pair of stopper surface portions that sandwich the vibration-isolating base in a circumferential direction in opposing directions,
the other of the inner member and the outer member includes a plate portion sandwiched between a pair of the stopper surface portions via the vibration-isolating base,
the vibration-isolating base includes a plurality of first protruding portions and a plurality of second protruding portions that protrude from the plate portion side toward the stopper surface portion side and are distributed in a circumferential direction,
the first protruding portion and the second protruding portion are pre-compressed between the plate portion and the stopper surface portion,
A strut mount, comprising: a first protrusion having a lower pre-compression amount than a second protrusion having a lower pre-compression amount. A strut mount comprising: an inner member attached to a rod tip of a shock absorber; an outer member surrounding an outer periphery of the inner member and attached to a vehicle body; and an annular vibration-isolating base interposed between the inner member and the outer member, each portion of which is made of the same elastic body,
one of the inner member and the outer member includes a pair of stopper surface portions that sandwich the vibration-isolating base in a circumferential direction in opposing directions,
the other of the inner member and the outer member includes a plate portion sandwiched between a pair of the stopper surface portions via the vibration-isolating base,
the vibration-isolating base includes a plurality of first protruding portions and a plurality of second protruding portions that protrude from the plate portion side toward the stopper surface portion side and are distributed in a circumferential direction,
the first protrusion is pre-compressed between the plate portion and the stopper surface portion,
There is a gap of 0.05 to 0.5 mm between the second protrusion and the stopper surface,
A strut mount, characterized in that a radial dimension of a base end of the first protrusion on the plate portion side is smaller than a radial dimension of a base end of the second protrusion on the plate portion side. 4. The strut mount according to claim 1 , wherein the first protrusion has a radial dimension that decreases toward a tip end on the stopper surface side. 5. The strut mount according to claim 1, wherein the first protrusion and the second protrusion are spaced apart in the circumferential direction.

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