JP7009300B2 - Anti-vibration device - Google Patents

Description

The present disclosure relates to an anti-vibration device.

Anti-vibration devices are known as prior art. In the conventional anti-vibration device, the inner cylinder, the outer cylinder arranged coaxially with the inner cylinder so as to surround the outer circumference of the inner cylinder, and between the inner cylinder and the outer cylinder. Some are arranged and provided with a rubber elastic body that connects both cylinders to each other (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2004-353798

By the way, in the vibration isolator, in general, the spring ratio of the spring constant in the axial direction to the spring constant in the axial direction is extremely large (for example, 10 to 20). For this reason, for example, when the anti-vibration device is used as a link bush that is press-fitted into the cylinder portion of the suspension link of an automobile, the position of the anti-vibration device is displaced in the axial direction where the spring constant is relatively low at the time of assembling the anti-vibration device. There is a risk that the movement of the link will not be the desired movement. Furthermore, there is also a demand for lowering the prying rigidity so as not to hinder the movement of the link.

An object of the present disclosure is to reduce the prying rigidity while reducing the spring ratio of the spring constant in the axial direction to the spring constant in the axial direction of the vibration isolator.

In the present disclosure, a tubular or axial inner member having a bulging portion in which the axial central portion bulges radially outward from both ends is formed in the axial central portion of the outer peripheral surface, and the periphery of the inner member. An intermediate cylinder member having a recessed portion in the inner peripheral surface corresponding to the bulging portion in which the central portion in the axial direction is recessed radially outward from both ends, and around the intermediate cylinder member. An outer cylinder member provided so that the radial distance between the intermediate cylinder member and the bulge portion and the recess portion is smaller than the radial distance between the inner cylinder member and the intermediate cylinder member. An inner rubber elastic body that is provided between the intermediate cylinder member and the outer cylinder member to connect the two, and an outer rubber elastic body that is thinner in the radial direction than the inner rubber elastic body. It is a vibration isolation device equipped with.

According to this, a bulging portion in which the central portion in the axial direction bulges outward in the radial direction from both ends is formed in the central portion in the axial direction on the outer peripheral surface of the inner member, and the central portion in the axial direction has a diameter larger than that in both ends. Since the recessed portion recessed outward in the direction is formed in the portion corresponding to the bulging portion on the inner peripheral surface of the intermediate cylinder member, the inner rubber elastic body expands when an external force in the axial direction is input to the vibration isolator. It comes into contact with the protruding portion and the recessed portion and is less likely to be deformed in the axial direction, and the inner rubber elastic body is easily deformed when a prying external force is input to the vibration isolator. Therefore, it is possible to reduce the prying rigidity while reducing the spring ratio of the spring constant in the axial direction to the spring constant in the axial direction of the vibration isolator.

It is preferable that the bulging portion and the recessing portion overlap each other when viewed from the axial direction, and the intermediate cylinder member is composed of a plurality of divided bodies divided in the circumferential direction.

According to this, since the bulging portion and the recessing portion overlap each other when viewed from the axial direction, the inner rubber elastic body is placed on the bulging portion and the recessed portion when an external force in the axial direction is input to the vibration isolator. It will surely come into contact and will be less likely to be deformed in the axial direction. Therefore, the spring ratio of the spring constant in the axial direction to the spring constant in the axial direction of the vibration isolator can be made smaller.

The outer cylinder member is preferably a single body that is not divided.

By the way, the tubular or axial inner member in which the bulging portion configured as described above is formed, and the portion provided around the inner member and corresponding to the bulging portion on the inner peripheral surface are configured as described above. In a vibration isolator provided with an outer cylinder member having a formed recessed portion and a rubber elastic body provided between the inner member and the outer cylinder member to connect the two, the bulging portion and the recessed portion are used as axes. When viewed from the direction, the outer cylinder members need to be composed of a plurality of divided bodies divided in the circumferential direction when they are overlapped with each other. In this case, when the outer cylinder member is narrowed inward in the radial direction and then the force is released, the vibration isolator returns to the state before the outer cylinder drawing.

Here, according to the above configuration, since the outer cylinder member is a single body that is not divided, even if the force is released after the outer cylinder drawing process, the vibration isolator does not perform the outer cylinder drawing process. It is possible to suppress the return to the state of.

It is preferable that the outer diameter of the intermediate cylinder member and the inner diameter of the outer cylinder member are constant in the entire axial direction.

According to this, since the outer diameter of the intermediate cylinder member and the inner diameter of the outer cylinder member are constant in the entire axial direction, the radial thickness of the outer rubber elastic body does not change. Therefore, the spring constant in the axial direction of the vibration isolator can be uniformly reduced as compared with the case where the thickness changes. Therefore, the spring ratio of the spring constant in the axial direction to the spring constant in the axial direction of the vibration isolator can be surely reduced.

According to the present disclosure, it is possible to reduce the prying rigidity while reducing the spring ratio of the spring constant in the axial direction to the spring constant in the axial direction of the vibration isolator.

It is a perspective view which shows the vibration isolation device which concerns on embodiment. It is a front view which shows the anti-vibration device. FIG. 2 is a cross-sectional view taken along the line III-III of FIG.

Hereinafter, embodiments will be described in detail with reference to the drawings.

The vibration isolator 1 is used, for example, as a link bush that is press-fitted into a cylinder portion (not shown) of a suspension link of an automobile. As shown in FIGS. 1 to 3, the vibration isolator 1 includes an inner cylinder member 2 (inner member), an intermediate cylinder member 3, an outer cylinder member 4, an inner rubber elastic body 5, and an outer rubber elastic film 6. (Outer rubber elastic body) is provided. Note that FIGS. 1 to 3 show the state before the outer cylinder drawing process, which will be described later, for convenience.

The inner cylinder member 2 is made of metal. The inner cylinder member 2 has a cylindrical shape. The inner cylinder member 2 is a single body that is not divided. Both ends in the axial direction of the inner cylinder member 2 project outward in the axial direction from the outer cylinder member 4, respectively. At the central portion in the axial direction of the outer peripheral surface of the inner cylinder member 2, a bulging portion 20 is formed in which the central portion in the axial direction bulges outward in the radial direction from both ends. The outer peripheral surface of the bulging portion 20 has an arcuate cross-sectional shape. This arc is, for example, the center of rotation relative to the intermediate cylinder member 3 (or the outer cylinder member 4) of the inner cylinder member 2 when the prying external force is input to the vibration isolator 1 (specifically, the axial direction of the inner cylinder member 2). It is a part of the circumference centered on the center and the center in the direction perpendicular to the axis).

The intermediate cylinder member 3 is made of resin in order to achieve high dimensional stability and weight reduction. The intermediate cylinder member 3 has a cylindrical shape. The intermediate cylinder member 3 is composed of two divided bodies 30, 30 which are bisected in the circumferential direction. A slight gap is formed in the circumferential direction between the divided bodies 30 and 30. The length of the intermediate cylinder member 3 in the axial direction is slightly longer than the formed portion of the bulging portion 20 in the inner cylinder member 2. The intermediate cylinder member 3 is provided coaxially with the inner cylinder member 2 on the outer periphery of the bulging portion 20 of the inner cylinder member 2. A recessed portion 31 is formed in a portion of the inner peripheral surface of the intermediate cylinder member 3 corresponding to the bulging portion 20 in which the central portion in the axial direction is recessed radially outward from both ends. The inner peripheral surface of the recessed portion 31 has an arcuate cross-sectional shape. This arc is, for example, a part of the circumference centered on the center of rotation relative to the intermediate cylinder member 3 (or the outer cylinder member 4) of the inner cylinder member 2 when the prying external force is input to the vibration isolator 1.

The inner diameter of the recessed portion 31 is larger than the outer diameter of the bulging portion 20 of the inner cylinder member 2 at the same position in the axial direction. The inner diameters of both ends in the axial direction of the intermediate cylinder member 3 excluding the recessed portion 31 are larger than the outer diameter of the inner cylinder member 2 excluding the bulging portion 20 and smaller than the outer diameter of the axially central portion of the bulging portion 20. , It is a constant size over the entire axial direction. Both ends in the axial direction (inner end portions in the radial direction) of the recess portion 31 overlap with the central portion in the axial direction (outer end portion in the radial direction) of the bulging portion 20 when viewed from the axial direction. The outer diameter of the intermediate cylinder member 3 is a constant size over the entire axial direction. Both end faces of the intermediate cylinder member 3 are inclined and extended inward in the axial direction from the outer side in the radial direction to the inner side in the radial direction.

The outer cylinder member 4 is made of metal. The outer cylinder member 4 has a cylindrical shape. The outer cylinder member 4 is a single body that is not divided. The outer cylinder member 4 is provided coaxially with the intermediate cylinder member 3 on the outer periphery of the intermediate cylinder member 3. The outer cylinder member 4 has an axial length shorter than that of the inner cylinder member 2, and is longer than the formed portion of the bulging portion 20 in the inner cylinder member 2 and the intermediate cylinder member 3. The inner diameter of the outer cylinder member 4 is slightly larger than the outer diameter of the intermediate cylinder member 3, and has a constant size over the entire axial direction. That is, the radial distance between the outer cylinder member 4 and the intermediate cylinder member 3 is smaller than the radial distance between the bulging portion 20 of the inner cylinder member 2 and the recessed portion 31 of the intermediate cylinder member 3. The outer diameter of the outer cylinder member 4 is a constant size over the entire axial direction. The outer cylinder member 4 is squeezed inward in the radial direction after being integrally molded with vulcanization, which will be described later. In this outer cylinder drawing process, the inner rubber elastic body 5 is compressed, but the outer rubber elastic film 6 is hardly compressed.

The inner rubber elastic body 5 has a cylindrical shape. The inner rubber elastic body 5 is provided between the bulging portion 20 of the inner cylinder member 2 and the recessed portion 31 of the intermediate cylinder member 3 and connects the two 2 and 3. In the inner rubber elastic body 5, the central portion in the axial direction bulges outward in the radial direction from both ends. Circular straight portions 51 are formed on both end faces of the inner rubber elastic body 5 in the axial direction when viewed from the axial direction. The depth of the curly portion 51 reaches the vicinity of each end in the axial direction of the bulging portion 20 of the inner cylinder member 2. The twisting portion 51 reduces the prying rigidity and the torsional rigidity of the vibration isolator 1.

The outer rubber elastic film 6 has a cylindrical shape. The outer rubber elastic film 6 is provided between the intermediate cylinder member 3 and the portion of the outer cylinder member 4 corresponding to the intermediate cylinder member 3, and connects the two 3 and 4. The outer rubber elastic film 6 is a rubber thin film having an extremely thin radial thickness than the inner rubber elastic body 5. As a result, the inner rubber elastic body 5 mainly functions as a spring, and the outer rubber elastic film 6 hardly functions as a spring. Therefore, the vibration isolator 1 has a so-called double bush structure in which the intermediate cylinder member 3 is embedded in the rubber elastic bodies 5 and 6, but the intermediate cylinder member 3 is not embedded in the rubber elastic bodies 5 and 6. It behaves like a single-layer bush structure.

Rubber elastic films 7 are formed on the outer peripheral surfaces of the inner cylinder member 2 excluding the bulging portion 20, the axially both end surfaces of the intermediate cylinder member 3, and the axially both ends of the inner peripheral surface of the outer cylinder member 4. Rubber protrusions 70 for identifying the orientation of the vibration isolator 1 are formed on the rubber elastic films 7 formed on both end faces in the axial direction of the intermediate cylinder member 3. A notch 71 is formed at the boundary between the divided bodies 30 and 30 of the intermediate tubular member 3 in the rubber elastic film 7 formed on both end faces in the axial direction of the intermediate tubular member 3. The notch 71 is a portion corresponding to a fall suppressing portion provided in a mold for vulcanization integral molding (not shown). This collapse suppressing portion suppresses each divided body 30 from collapsing during vulcanization integral molding. The rubber elastic film 7 and the rubber protrusion 70 are integrally molded by vulcanization on the inner cylinder member 2, the intermediate cylinder member 3, and the outer cylinder member 4 together with the inner rubber elastic body 5 and the outer rubber elastic film 6.

The spring ratio of the static spring constant in the axial direction to the static spring constant in the axial direction of the vibration isolator 1 configured as described above is, for example, 1 to 6. This spring ratio is preferably 1 in that the inner rubber elastic body 5 is evenly deformed in each direction when an external force is input to the vibration isolator 1.

-effect-
From the above, according to the present embodiment, the bulging portion 20 in which the central portion in the axial direction bulges outward in the radial direction from both ends is formed in the central portion in the axial direction on the outer peripheral surface of the inner cylinder member 2. Since the recessed portion 31 in which the central portion is recessed radially outward from both ends is formed in the portion corresponding to the bulging portion 20 on the inner peripheral surface of the intermediate tubular member 3, the axial direction to the vibration isolator 1 When the external force is input, the inner rubber elastic body 5 abuts on the bulging portion 20 and the recessed portion 31 and is less likely to be deformed in the axial direction. Easy to pry and deform. Therefore, it is possible to reduce the prying rigidity while reducing the spring ratio of the static spring constant in the axial direction to the static spring constant in the axial direction of the vibration isolator 1.

Further, since the bulging portion 20 and the dented portion 31 overlap each other when viewed from the axial direction, the inner rubber elastic body 5 has the bulging portion 20 and the dented portion 20 when an external force in the axial direction is input to the vibration isolator 1. It surely abuts on the portion 31 and is less likely to be deformed in the axial direction. Therefore, the spring ratio of the static spring constant in the axial direction to the static spring constant in the axial direction of the vibration isolator 1 can be made smaller.

Further, since the outer cylinder member 4 is a single body that is not divided, even if the force is released after the outer cylinder drawing process is performed, the vibration isolator 1 returns to the state before the outer cylinder drawing process. Can be suppressed.

Further, since the outer rubber elastic film 6 having a thinner radial thickness than the inner rubber elastic body 5 is provided between the intermediate cylinder member 3 and the outer cylinder member 4 and connects the two 3 and 4, the inner side. Even if the rubber elastic body 5 is deteriorated, the intermediate cylinder member is formed by the outer rubber elastic film 6 having a relatively thin radial thickness as compared with the case where the outer cylinder member 4 is directly externally fitted to the intermediate cylinder member 3. It is possible to suppress the movement of 3 in the outer cylinder member 4 in the axial direction.

Further, since the outer rubber elastic film 6 having a thickness in the radial direction thinner than the inner rubber elastic body 5 is provided between the intermediate cylinder member 3 and the outer cylinder member 4, both 3 and 4 are connected to each other. Due to the outer rubber elastic membrane 6 having a relatively thin directional thickness, the compression ratio of the inner rubber elastic body 5 varies due to the dimensional variation of the intermediate tubular member 3 and the tubular portion of the suspension link, and eventually the vibration isolator 1 It can absorb and mitigate variations in spring characteristics.

Further, since the outer diameter of the intermediate cylinder member 3 and the inner diameter of the outer cylinder member 4 are constant in the entire axial direction, the radial thickness of the outer rubber elastic film 6 does not change. Therefore, the static spring constant in the axial direction of the vibration isolator 1 can be uniformly reduced as compared with the case where the thickness changes. Therefore, the spring ratio of the static spring constant in the axial direction to the static spring constant in the axial direction of the vibration isolator 1 can be surely reduced.

(Other embodiments)
In the above embodiment, the vibration isolator 1 is used as a link bush, but the present invention is not limited to this, and for example, it may be used as an engine mount.

Further, in the above embodiment, the inner member is composed of the inner cylinder member 2, but the present invention is not limited to this, and the inner member may be composed of a solid inner shaft member.

Further, in the above embodiment, the intermediate cylinder member 3 is made of resin, but the present invention is not limited to this, and the intermediate cylinder member 3 may be made of metal.

Further, in the above embodiment, the bulging portion 20 and the dented portion 31 overlap each other when viewed from the axial direction, but they do not have to overlap each other. In this case, the intermediate cylinder member 3 does not have to be composed of a plurality of divided bodies 30.

Further, in the above embodiment, the cross-sectional shape of the outer peripheral surface of the bulging portion 20 and the inner peripheral surface of the recessed portion 31 is arcuate, but the central portion in the axial direction bulges outward in the radial direction from both ends. As long as it is dented), its shape is not limited to an arc shape, and may be, for example, an elliptical shape or a triangular shape.

Further, in the above embodiment, the outer diameters of the intermediate cylinder member 3 and the outer cylinder member 4 are each set to a constant size over the entire axial direction, but the sizes may be changed. However, a constant size is desirable in terms of reducing the spring ratio of the static spring constant in the axial direction to the static spring constant in the axial direction of the vibration isolator 1.

Further, in the above embodiment, the outer rubber elastic film 6 hardly functions as a spring, but the present invention is not limited to this, and for example, by making the radial thickness slightly thicker than that of the above embodiment, the spring is slightly thicker. May function.

As described above, the present disclosure can be applied to anti-vibration devices and the like.

1 Anti-vibration device 2 Inner cylinder member (inner member)
20 bulging part 3 intermediate cylinder member 30 split body 31 recessed part 4 outer cylinder member 5 inner rubber elastic body 6 outer rubber elastic film (outer rubber elastic body)

Claims (4)

A cylindrical or axial inner member in which a bulging portion is formed in the axially central portion of the outer peripheral surface so that the axially central portion bulges radially outward from both ends.
An intermediate tubular member provided around the inner member and having a recessed portion in the inner peripheral surface corresponding to the bulging portion in which the central portion in the axial direction is recessed radially outward from both ends.
An outer cylinder member provided around the intermediate cylinder member so that the radial distance between the intermediate cylinder member and the intermediate cylinder member is smaller than the radial distance between the bulging portion and the recessed portion.
An inner rubber elastic body provided between the inner member and the intermediate cylinder member and connecting the two,
A vibration isolator provided between the intermediate cylinder member and the outer cylinder member, connecting the two, and having an outer rubber elastic body having a thickness thinner in the radial direction than the inner rubber elastic body. In claim 1,
The bulging portion and the recessing portion overlap each other when viewed from the axial direction.
The intermediate cylinder member is a vibration isolator composed of a plurality of divided bodies divided in the circumferential direction. In claim 2,
The outer cylinder member is a vibration isolator that is a single body that is not divided. In any one of claims 1 to 3,
A vibration isolator in which the outer diameter of the intermediate cylinder member and the inner diameter of the outer cylinder member are constant in the entire axial direction.

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