JP2018162845A - Mount rubber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain variation of spring characteristics even when a load is applied to a mount rubber.SOLUTION: In a mount rubber of this invention, a first large diameter portion, a piller-like small diameter portion, and a second large diameter portion are integrally formed in a thickness direction, and the mount rubber has a through hole which penetrates through the first large diameter portion, the small diameter portion, and the second large diameter portion. The small diameter portion has at least one protrusion. A load applied to the mount rubber is absorbed by elastic deformation of the protrusion, and external force applied to the small diameter portion is alleviated. An increase of rigidity caused by thickness deviation due to the load applied to the mount rubber can be restrained, and, therefore, variation in spring characteristics can be restrained.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a mount rubber used for fixing a fastening part and a fastening part in a vehicle such as an automobile.

  In a vehicle such as an automobile, a mount rubber is used to fix a fastening part to an engine or a vehicle body, which is a part to be fastened, with a fixing member such as a bolt and a nut. The mount rubber is formed of an elastic body such as rubber and reduces vibration transmitted between the fastening part and the fastening part.

  A fastening part mounting structure using a mount rubber is described in Patent Documents 1 and 2, for example. A groove portion is formed on the outer periphery of the mount rubber, and the mounting rubber is mounted in the attachment hole of the fastening component so that the fastening component fits in the groove portion. A through hole through which a bolt is inserted is provided at the center of the mount rubber, and is fixed by a fixing member such as a bolt and a nut.

  By providing a spacer in the through-hole through which the bolt is inserted or adjusting the tightening amount of the bolt, the mount rubber is compressed with a predetermined force to obtain a constant spring characteristic. The vibration generated in the fastening part is absorbed and attenuated by the elastic deformation of the mount rubber, and the vibration transmitted to the fastened part is reduced.

JP 2002-13590 A JP 2008-236982 A

  The mount rubber is set to have a predetermined spring characteristic while being fixed by a fixing member such as a bolt and a nut. However, if a non-uniform load is applied from the fastening part to the mount rubber due to the displacement of the fastening part and the part to be fastened due to thermal expansion or an assembly error, the mount rubber becomes uneven and the rigidity of the uneven part increases. . When the rigidity increases, the spring characteristics of the mount rubber increase, and the spring characteristics change. Therefore, the mount rubber cannot sufficiently absorb vibration.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a mount rubber that can stably absorb vibration even when a non-uniform load is applied to the mount rubber with little variation in spring characteristics. And

The present invention includes the following aspects (1) to (5).
(1) The mount rubber of the present invention is a mount rubber in which a first large diameter portion, a columnar small diameter portion, and a second large diameter portion are integrally formed in a thickness direction, and the first large diameter portion A hole penetrating the small-diameter portion and the second large-diameter portion is provided, and the small-diameter portion includes at least one protrusion.
(2) In (1), the protrusion has a trapezoidal cross-sectional shape in the thickness direction.
(3) In (1) or (2), the small-diameter portion includes a plurality of the protruding portions.
(4) In any one of (1) to (3), the small-diameter portion includes a plurality of protrusions at different positions in the thickness direction.
(5) In any one of (1) to (4), a groove recessed in the thickness direction is formed in at least one of the first large diameter portion or the second large diameter portion. .

  According to the present invention, it is possible to provide a mount rubber that can stably absorb vibration even when a non-uniform load is applied to the mount rubber.

1 is a perspective view showing a structure of a mount rubber 1. FIG. 3 is a top view showing the structure of the mount rubber 1. FIG. 3 is a side view showing the structure of the mount rubber 1. FIG. It is sectional drawing in AA of FIG. 2 of the mount rubber 1. FIG. It is sectional drawing in BB of FIG. 3 of the mount rubber 1. FIG. It is a figure which shows the attachment structure of the fastening components by the mount rubber. It is a figure which shows low rigidity by a projection part. It is a perspective view which shows the other Example of the shape and arrangement | positioning of a projection part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 3 are views schematically showing the structure of the mount rubber 1 of the embodiment. FIG. 1 is a perspective view of the mount rubber 1, FIG. 2 is a top view as viewed from the upper side in the Z direction that is the thickness direction, and FIG. 3 is a side view as viewed from the Y direction perpendicular to the Z direction.

  As shown in FIGS. 1 to 3, the mount rubber 1 has an annular first large diameter portion 2 and second large diameter portion 3, and a columnar shape that connects the first large diameter portion 2 and the second large diameter portion 3. The small diameter portion 4 has a structure formed integrally. The mount rubber 1 is mounted in a mounting hole of the fastening component 11 so that the fastening component 11 is sandwiched between the first large diameter portion 2 and the second large diameter portion 3, and is a through hole provided in the central portion of the mount rubber 1 7 and a fixing member such as a nut provided on the fastened component 12 side. The outer shape of the first large diameter portion 2 and the second large diameter portion 3 may be the same shape or different shapes. For example, the diameter of the second large diameter portion 3 may be larger than the diameter of the first large diameter portion 2, but the diameter of the small diameter portion 4 is larger than any of the first large diameter portion 2 and the second large diameter portion 3. small.

  The mount rubber 1 is made of a rubber material. Rubber materials include natural rubber (NR), isopropylene rubber (IR), butadiene rubber (BR), styrene butadiene rubber (SBR), ethylene propylene rubber (EPDM), nitrile rubber (NBR), chloroprene rubber (CR), Rubber materials such as butyl rubber (IIR) and acrylic rubber (ACM) can be used, and these rubber materials may be used in combination. The rubber hardness is preferably about A20 to A80 in JISK6253 durometer type A.

  In this embodiment, as shown in FIG. 3, the protrusion part 5 is provided in the outer periphery of the small diameter part 4. As shown in FIG. FIG. 4 is a diagram schematically showing an AA cross section of FIG. As shown in the sectional view of FIG. 4, the side wall of the through hole 7 is flat and continuous. The protrusion 5 is provided at the approximate center in the thickness direction (Z direction) of the small diameter portion 4 and protrudes in the XY direction orthogonal to the Z direction. The cross-sectional shape of the protruding portion 5 is a trapezoidal shape in which the thickness of the tip portion is smaller than the thickness of the base portion in contact with the small diameter portion 4, and the protruding portion 5 and the first large diameter portion 2 or the second large diameter portion 3. There is a gap between them. When a load is applied to the protrusion 5 from the XY directions, the protrusion 5 is elastically deformed to absorb the load. Since the protrusion 5 is elastically deformed to absorb the load, the external force applied to the small diameter portion 4 from the XY direction is relaxed.

  The length by which the protruding portion 5 protrudes in the XY direction is such a length that the tip portion of the protruding portion 5 is inside the end portions of the first large diameter portion 2 and the second large diameter portion 3. Further, it is preferable that the length is 0.5 to 1.5 times the thickness of the base portion of the protrusion 5. If the length of the projection 5 is shorter than 0.5 times, the effect of reducing the external force due to the deformation of the projection 5 is small, and if the length of the projection 5 is longer than 1.5 times, the strength of the projection 5 is increased. It becomes weak and easy to break.

  FIG. 5 is a diagram schematically showing a BB cross section of FIG. 3. The mount rubber 1 is provided with four protrusions 5 having the same shape on the outer periphery of the small diameter portion 4 at every 90 degrees so as to absorb the load applied from the XY directions. The arrangement of the projections 5 is not limited to this, and the arrangement location may be changed based on the magnitude and direction of the predicted load. Moreover, you may arrange | position combining the projection part 5 of a different shape.

  As shown in FIG. 4, a groove 6 that is recessed in the thickness direction may be provided on at least one surface of the first large diameter portion 2 or the second large diameter portion 3. By providing the groove portion 6, when the mount rubber 1 receives a load from the XY direction, it is possible to suppress the mount rubber 1 from being unevenly thickened and increasing its rigidity. The groove portion 6 may be provided only on one of the first large diameter portion 2 or the second large diameter portion 3 or may be provided on both the first large diameter portion 2 and the second large diameter portion 3.

  As an embodiment, a cross section of a structure in which the fastening component 11 is fixed to the fastened component 12 using the mount rubber 1 is schematically shown in FIG. In a state where the mount rubber 1 is mounted in an attachment hole or the like of the fastening component 11, the fastening component 11 is held between the first large diameter portion 2 and the second large diameter portion 3. The protruding portion 5 protruding from the side surface of the small diameter portion 4 has its tip surface abutted against the inner wall of the mounting hole of the fastening part 11 and restricts the mount rubber 1 from moving in the XY direction.

  A nut 10 is fixed to the fastening part 12 by welding or the like. The fastening component 11 to which the mount rubber 1 is attached is fixed by a bolt 9 and a nut 10 inserted through the through hole 7 of the mount rubber 1. A spacer 8 that prevents excessive compression due to excessive tightening of the bolt is disposed in the through hole 7, and the mount rubber 1 is maintained at a predetermined thickness by the spacer 8. The spacer 8 may be integrated with the mount rubber 1 in advance to form a single component. Further, the mount rubber 1 may have a predetermined thickness by adjusting the tightening amount of the bolt without providing the spacer 8.

  The vibration generated in the fastening part 11 is absorbed and damped by the elastic deformation of the mount rubber 1. For this reason, the vibration transmitted to the to-be-fastened component 12 can be reduced. In the fixing structure of FIG. 6, when a load in the XY direction is applied from the fastening part 11 to the mount rubber 1 due to displacement due to thermal expansion or the like, the protrusion 5 is elastically deformed to absorb this. For this reason, a load from the XY direction is not directly applied to the small diameter portion 4, a change in rigidity of the mount rubber 1 due to uneven thickness can be reduced, and a variation in spring characteristics is suppressed.

  FIG. 7 shows the result of comparing the load deflection of the mount rubber 1 with the presence or absence of the protrusion 5 for the oval mount rubber 1. When there is a large assembling error between the components of the fastening component 11 and the fastened component 12, the relative position of the fastening component 11 and the fastened component 12 is adjusted by adjusting the attachment hole of the fastening component 11 to be a long hole. Fastened with fixing members such as bolts and nuts at the position. The mount rubber 1 to be mounted in the long hole-shaped attachment hole has a small-diameter portion 4 having an oval shape and a long hole-shaped through hole 7.

  FIG. 7A is a side view of the oval mount rubber 1 having the protrusions 5, and FIG. 7B is a CC cross section showing the arrangement of the protrusions 5 as viewed from the top. In the oval mount rubber 1, two protrusions 5 are provided on each long side, and columnar protrusions 13 connecting the first large diameter part and the second large diameter part are provided on each short side. By providing, the rigidity of the long side and the short side is adjusted.

  From the load and deflection graph of FIG. 7, the mount rubber 1 provided with the protrusions 5 (with protrusions) is a comparative example in which the protrusions 5 are not provided for both the load in the longitudinal direction and the short direction (protrusion). It can be seen that there is a large amount of deflection, low stiffness and low spring constant compared to (none). In the comparative example, the inclination of the graph is greatly different between the longitudinal direction and the short direction, and the rigidity is greatly different depending on the direction. On the other hand, in the oval mount rubber 1 provided with the protrusions 5, the rigidity on the long side and the short side is adjusted by the protrusions 5 and the columnar protrusions 13. The slope of the graph is almost the same in the hand direction, indicating that the stiffness is the same in both directions.

  Another embodiment of the shape and arrangement of the protrusion 5 is shown in FIG. The protrusion 5 may have a ring shape coaxial with the small diameter portion 4 as shown in FIG. 8A, or the protrusion 5 of FIG. 3 may be divided into two as shown in FIG. 8B. Further, as shown in FIG. 8C, the protruding portion 5 can be divided into upper and lower portions instead of the central portion of the small diameter portion 4.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications may be made within the scope of the gist of the present invention described in the claims. It can be changed.

DESCRIPTION OF SYMBOLS 1 Mount rubber 2 1st large diameter part 3 2nd large diameter part 4 Small diameter part 5 Protrusion part 6 Groove part 7 Through hole 8 Spacer 9 Bolt 10 Nut 11 Fastening part 12 Fastening part 13 Columnar protrusion part

Claims (5)

A mount rubber in which a first large diameter portion, a columnar small diameter portion and a second large diameter portion are integrally formed in the thickness direction,
A hole penetrating the first large diameter portion, the small diameter portion and the second large diameter portion;
The mount rubber, wherein the small diameter portion includes at least one protrusion.   The mount rubber according to claim 1, wherein the protrusion has a trapezoidal cross-sectional shape in the thickness direction.   The mount rubber according to claim 1, wherein the small diameter portion includes a plurality of the protrusions.   The mount rubber according to any one of claims 1 to 3, wherein the small-diameter portion includes a plurality of protrusions at different positions in the thickness direction.   5. The mount rubber according to claim 1, wherein a groove recessed in a thickness direction is formed in at least one of the first large diameter portion or the second large diameter portion. .

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