Body mount

Abstract

To provide a body mount capable of providing a seat part having high stopper strength while preventing a crack of a resin outer cylinder member.SOLUTION: The body mount 1 includes an outer cylinder member 2 made of resin, an inner cylinder member 3 disposed in a hollow portion of the outer cylinder member 2, and a rubber elastic body 4 interposed between the outer cylinder member 2 and the inner cylinder member 3, wherein the outer cylinder member 2 is press-fitted and fixed to an insertion hole 10a of a holder 10, wherein the outer cylinder member 2 has a protrusion portion 5 protruding inward in a radial direction from an inner circumferential surface 2c, the protrusion portion 5 has a hollow structure penetrating in an axial direction, and a plurality of ribs 7 extending in the axial direction are formed on an inner surface of the protrusion portion 5. The rubber elastic body 4 has a stopper part 4a covering the rib 7 and projecting from one end of the outer cylinder member 2.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a body mount. [Background technology]

[0002] Body mounts are used as vibration-damping devices for vehicle suspension mechanisms, etc., and are constructed by placing an elastic material between an inner cylindrical member and an outer cylindrical member. In use, the outer cylindrical member is press-fitted into an insertion hole in a holder on the suspension member side, and the inner cylindrical member is inserted onto a bolt on the body side and tightened with a nut.

[0003] One known body mount of this type is one in which a highly rigid stopper seat is provided at the tip of an outer tubular member and this seat is covered with a stopper made of an elastic material. For example, Patent Document 1 discloses a technology in which a pair of protrusions are formed at the tip of a resin outer tubular member at a circumferentially spaced-apart position, and the thickness of these protrusions is made thicker than the remaining portions to form seats. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-62977 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the body mount described in Patent Document 1, the tip of the outer tube member is partially thickened to form a seat, which creates a rigidity difference along the circumferential direction of the tip of the outer tube member, posing a problem in that the outer tube member is more likely to crack when the body mount is press-fitted into the holder.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a body mount that can provide a seat portion with high stopper strength while preventing cracking of a resin outer cylindrical member. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention provides a body mount comprising an outer tube member made of resin, an inner tube member arranged in a hollow portion of the outer tube member, and an elastic body interposed between the outer tube member and the inner tube member, wherein the outer tube member is press-fitted and fixed into an insertion hole of a holder, wherein the outer tube member has a protrusion protruding radially inward from its inner surface, the protrusion having a hollow structure that penetrates the outer tube member in the axial direction, a rib extending in the axial direction formed on the inner surface of the protrusion, and the elastic body has a stopper portion that covers the rib and protrudes from one end of the outer tube member. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a seat portion having high stopper strength while preventing cracking of the resin outer cylindrical member. Objects, configurations, and effects other than those described above will become apparent from the following description of the embodiment. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective view of a body mount according to the embodiment. [Figure 2] FIG. 2 is a perspective view of the body mount as seen from the upside down direction of FIG. 1. [Figure 3] FIG. [Figure 4] FIG. 2 is a vertical cross-sectional view of the body mount. [Figure 5] FIG. 1 is a cross-sectional view of a body mount. [Figure 6] FIG. 2 is a perspective view of an outer cylinder member provided on the body mount. [Figure 7] FIG. 7 is a perspective view of the outer cylindrical member, seen from the upside down direction of FIG. 6. [Figure 8] FIG. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 8. [Figure 10]FIG. 10 is a cross-sectional view showing a state in which the body mount is assembled into the insertion hole of the holder. [Figure 11] FIG. 10 is a vertical cross-sectional view of a body mount according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] FIG. 1 is a perspective view of a body mount according to an embodiment, FIG. 2 is a perspective view of the body mount viewed from the upside down direction of FIG. 1, FIG. 3 is a front view of the body mount, FIG. 4 is a vertical cross-sectional view of the body mount, and FIG. 5 is a horizontal cross-sectional view of the body mount.

[0012] As shown in Figures 1 to 5, the body mount 1 of the embodiment is configured to include an outer tube member 2, an inner tube member 3 arranged within the hollow portion of the outer tube member 2, and a rubber elastic body 4 interposed between the outer tube member 2 and the inner tube member 3 to connect them together.

[0013] The inner cylinder member 3 is a cylindrical member made of metal and is disposed in the center of the body mount 1. The inner cylinder member 3 has a hollow hole 3a that penetrates along the axial direction, and is fixed to the vehicle body side such as a frame via a bolt that is inserted into the hollow hole 3a. Both vertical ends of the inner cylinder member 3 protrude from both vertical ends of the outer cylinder member 2.

[0014] The outer cylindrical member 2 is a cylindrical member made of resin, and is arranged radially outwardly of and spaced apart from the inner cylindrical member 3. An outer peripheral surface 2a of the outer cylindrical member 2 is a portion that is press-fitted into an insertion hole of a holder (described later) on the suspension member side.

[0015] 6 is a perspective view of the outer tube member 2, FIG. 7 is a perspective view of the outer tube member 2 viewed from the upside down direction to that of FIG. 6, FIG. 8 is a front view of the outer tube member 2, and FIG. 9 is a cross-sectional view taken along line IX-IX of FIG.

[0016] The outer tube member 2 is a resin molded product formed by injection molding. As shown in FIGS. 6 to 9, the outer tube member 2 has an outer peripheral surface 2a with a constant diameter from the upper end to the lower end in the axial direction. In other words, the outer peripheral surface 2a of the outer tube member 2 is a press-fit portion without any recesses. A flange portion 2b having a larger diameter than the outer peripheral surface 2a is integrally formed at one end of the outer tube member 2. The flange portion 2b is formed at the end opposite the press-fitting direction when the outer tube member 2 is press-fitted into the insertion hole of the holder, and functions as a stopper that determines the press-fit position of the outer tube member 2. In the following description, of the two axial ends of the outer tube member 2, the side without the flange portion 2b (the upper side in FIG. 7) will be referred to as one end, and the side with the flange portion 2b will be referred to as the other end.

[0017] Protrusions 5 that protrude radially inward are integrally formed at two locations on the inner peripheral surface 2c of the outer cylindrical member 2. These protrusions 5 have a hollow structure with through holes 6 that extend in the axial direction of the outer cylindrical member 2, and are arranged at positions that are 180 degrees apart with the inner cylindrical member 3 in between.

[0018] The protrusion 5 has an arc-shaped portion 5a that faces the inner circumferential surface 2c via the through hole 6, and a pair of connecting portions 5b that support both ends of the arc-shaped portion 5a and connect to the inner circumferential surface 2c. The thickness of the connecting portions 5b is approximately the same as the thickness between the outer circumferential surface 2a and the inner circumferential surface 2c, making it less likely that sink marks will occur at the connection points between the connecting portions 5b and the inner circumferential surface 2c during molding.

[0019] The through hole 6 has a shape in which the outer circumferential dimension contacting the inner circumferential surface 2c is longer than the inner circumferential dimension contacting the arc-shaped portion 5a, so that the protrusion 5 has an annular wall whose outer shape is approximately trapezoidal in plan view, and has increased strength against external pressure from the radial direction.

[0020] The protrusion 5 is formed along a range extending from one end of the outer tube member 2 to partway inside the inner circumferential surface 2c. The arc-shaped portion 5a of the protrusion 5 is set to the same height as one end of the inner circumferential surface 2c. The connecting portion 5b of the protrusion 5 is connected to the inner circumferential surface 2c at a position inward of the one end of the outer tube member 2, and has a notch 5c that is stepped down from one end of the arc-shaped portion 5a (see FIG. 7). In other words, the protrusion 5 is connected to the inner circumferential surface 2c via the connecting portion 5b while avoiding contact with the one end of the outer tube member 2.

[0021] A plurality of axially extending ribs 7 are formed at intervals in the circumferential direction on the inner surface of the arc-shaped portion 5a of the protrusion 5, and in this embodiment, three ribs 7 are arranged in a comb-like pattern. These ribs 7 extend from one end of the protrusion 5 to partway along the inner surface of the arc-shaped portion 5a, and function as seats for the stopper portions 4a of the rubber elastic body 4, which will be described later.

[0022] The rubber elastic body 4 is interposed between the outer tube member 2 and the inner tube member 3, and elastically connects the outer tube member 2 and the inner tube member 3. The rubber elastic body 4 is vulcanized and bonded to the inner circumferential surface 2c of the outer tube member 2 and the outer circumferential surface of the inner tube member 3 by injecting molten rubber between the outer tube member 2 and the inner tube member 3 and cooling it. At this time, the injected molten rubber is also supplied to the inside of the through-hole 6 of the protrusion 5 and the portion covering the protrusion 5, so that the rubber elastic body 4 is interposed between the outer tube member 2 and the inner tube member 3 so as to encase the protrusion 5. In addition, because a notch 5c is formed in the connecting portion 5b of the protrusion 5, the injected molten rubber is also injected into the through-hole 6 through the notch 5c.

[0023] Then, by cooling the injected molten rubber, a pair of stopper portions 4a are formed on the rubber elastic body 4, covering the protrusions 5 and protruding from one end of the outer cylindrical member 2. Here, multiple ribs 7 are formed on the inner surface of the arc-shaped portion 5a of the protrusions 5, and these ribs 7 have high rigidity in the axial direction and function as seats that absorb external forces from the stopper portions 4a. Furthermore, because the rubber elastic body 4 is interposed between the outer cylindrical member 2 and the inner cylindrical member 3 so as to encase the protrusions 5, the removal force of the rubber elastic body 4 is increased, making it difficult to remove from the outer cylindrical member 2. Furthermore, because a pair of protrusions 5 facing each other across the inner cylindrical member 3 is present inside the rubber elastic body 4, the spring force of the rubber elastic body 4 in the direction in which these protrusions 5 face each other is increased.

[0024] FIG. 10 is a cross-sectional view showing the state in which the body mount 1 is assembled into the insertion hole 10a of the holder 10 on the suspension member side.

[0025] When assembling the body mount 1 to the holder 10, as shown in Fig. 10, one end of the outer tubular member 2 without the flange portion 2b is inserted into the insertion hole 10a, and then the outer tubular member 2 is pressed toward the inside of the insertion hole 10a (downward in Fig. 10) until the flange portion 2b abuts against the opening edge of the insertion hole 10a. This causes the outer peripheral surface 2a of the outer tubular member 2 to be press-fitted into the inner peripheral surface of the insertion hole 10a, generating a force that presses the outer tubular member 2 radially inward, and the body mount 1 is fixed to the holder 10.

[0026] At this time, the entire outer peripheral surface 2a of the body mount 1, which has no recesses, is in close contact with the inner peripheral surface of the insertion hole 10a, ensuring a sufficient contact area between the outer peripheral surface 2a and the insertion hole 10a and maintaining a high force for removal from the holder 10. In addition, multiple highly rigid ribs 7 are formed on the inner surface of the protrusion 5 that protrudes radially inward from the inner peripheral surface 2c of the outer cylindrical member 2, allowing the outer cylindrical member 2 to be configured as a resin molded product with little difference in rigidity in the circumferential direction, thereby suppressing cracking of the body mount 1 when it is press-fitted.

[0027] As described above, the body mount 1 according to this embodiment can provide the following advantageous effects.

[0028] The body mount 1 according to this embodiment is configured by interposing a rubber elastic body 4 between an inner tube member 3 and a resin outer tube member 2, and the outer tube member 2 has a hollow protrusion 5 formed on its inner circumferential surface 2c that protrudes radially inward, a rib 7 extending in the axial direction formed on the inner surface of this protrusion 5, and a stopper portion 4a formed on the rubber elastic body 4 that covers the rib 7 and protrudes from the outer tube member 2. This allows the highly rigid rib 7 to be disposed on the inner surface of the protrusion 5 that protrudes from the inner circumferential surface 2c of the outer tube member 2, and achieves a resin outer tube member 2 with little difference in rigidity in the circumferential direction, thereby suppressing the occurrence of cracks in the outer tube member 2 during press-fitting.

[0029] Furthermore, because the rubber elastic body 4 surrounding the protrusion 5 enters the through-hole 6, the removal force of the rubber elastic body 4 is increased, making it difficult to remove from the outer tube member 2, and the spring force of the rubber elastic body 4 in the direction facing the protrusion 5 is increased. Moreover, there is no need to provide a recess on the outer peripheral surface 2a of the outer tube member 2, and the outer peripheral surface 2a without a recess can be brought into close contact with the insertion hole 10a of the holder 10 over a wide area, thereby preventing a decrease in the removal force from the holder 10.

[0030] In addition, in this embodiment, multiple ribs 7 are arranged in a comb-like pattern at intervals around the circumferential direction of the protrusion 5, thereby increasing the stopper strength of the ribs 7 that function as a seat for the stopper portion 4a.

[0031] Furthermore, in this embodiment, the protrusion 5 is composed of an arc-shaped portion 5a facing the inner circumferential surface 2c and a pair of connecting portions 5b supporting both ends of the arc-shaped portion 5a, and by making the axial length of the connecting portion 5b connecting to the inner circumferential surface 2c shorter than that of the arc-shaped portion 5a, a stepped notch 5c is formed at the circumferential end of the arc-shaped portion 5a, so that the molten rubber injected between the outer tube member 2 and the inner tube member 3 can be reliably guided from the notch 5c into the through hole 6. However, the arc-shaped portion 5a and the connecting portion 5b may be set to the same height without providing such a notch 5c.

[0032] Furthermore, in this embodiment, a pair of protrusions 5 are provided at positions that are 180 degrees apart across the inner tube member 3. Therefore, for example, by assembling the pair of protrusions 5 in a direction that faces each other in the left-right direction of the vehicle body, left-right vibrations of the vehicle body can be suitably absorbed by the rubber elastic body 4, the spring force of which is increased by the presence of the protrusions 5, and large vibrations that occur when the vehicle accelerates or decelerates can be suitably absorbed by the rubber elastic body 4 in parts where the protrusions 5 are not present.

[0033] (Variation) FIG. 11 is a vertical cross-sectional view of a body mount 1 according to a modified example, and parts corresponding to those in FIGS. 1 to 9 are given the same reference numerals.

[0034] 11, in the body mount 1 according to the modified example, the axial length of the arc-shaped portion 5a of the protrusion 5 is the same as that of the rib 7, and the rib 7 is formed along the entire length of the inner surface of the arc-shaped portion 5a. With this configuration, the axial length of the rib 7 is longer, further increasing the stopper strength of the rib 7.

[0035] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention. The present invention covers all technical matters included in the technical ideas described in the claims. The above-described embodiments are preferred examples, but a person skilled in the art can realize various alternatives, modifications, variations, or improvements from the contents disclosed in this specification, and these are included in the technical scope described in the appended claims.

[0036] For example, in the above embodiment, two protrusions 5 are provided on the inner peripheral surface 2c of the outer cylindrical member 2, sandwiching the inner cylindrical member 3, at 180 degrees from each other, but the number of protrusions 5 is not limited to two and may be one or three or more. In this case, the rib 7 does not necessarily have to be formed on all of the protrusions 5, as long as it is formed on the inner surface of at least one of the protrusions 5.

[0037] In the above embodiment, the protrusion 5 is formed from one end of the outer cylindrical member 2 to a position partway to the other end, but the protrusion 5 may be formed to the same length as the entire length of the outer cylindrical member 2. [Explanation of symbols]

[0038] 1 Body Mount 2. Outer cylinder member 2a Outer surface 2b Flange part 2c Inner surface 3. Inner cylinder member 3a Hollow hole 4. Rubber elastic body (elastic body) 4a Stopper part 5 Protrusion 5a Arc-shaped part 5b Connecting part 5c Notch 6 through holes 10 Holder 10a Insertion hole

Claims

1. an outer cylinder member made of resin; an inner cylindrical member disposed in a hollow portion of the outer cylindrical member; an elastic body interposed between the outer cylindrical member and the inner cylindrical member, In a body mount in which the outer cylindrical member is press-fitted and fixed into an insertion hole of a holder, the outer cylindrical member has a protrusion protruding radially inward from an inner circumferential surface, the protrusion has a hollow structure that penetrates the outer cylindrical member in the axial direction, An axially extending rib is formed on the inner surface of the protrusion, The elastic body has a stopper portion that covers the rib and protrudes from one end of the outer cylindrical member. Characterized by a body mount.

2. 2. The body mount according to claim 1, The ribs are formed in plurality at intervals in the circumferential direction of the protrusion. Characterized by a body mount.

3. 3. The body mount according to claim 2, The protrusion has a notch at an end in the circumferential direction. Characterized by a body mount.

4. 2. The body mount according to claim 1, The protrusions are provided at two positions that are 180 degrees apart from each other across the inner cylindrical member. Characterized by a body mount.

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