JP2015025540A - Vibration isolator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration isolator capable of suppressing transmission of sliding noise to a vibration receiving portion side, in a non-adhesion type vibration isolator.SOLUTION: A vibration isolator includes: a bracket 12 (first mounting member) connected to a vibration generating portion side; an inner cylinder 14 (second mounting member) connected to a vibration receiving portion side; and a rubber elastic body 16 (elastic body) slidably connected to the bracket 12, fixed while applying pre-compression to the inner cylinder 14, and disposed between the bracket 12 and the inner cylinder 14 without adhesion.

Description

  The present invention relates to a vibration isolator used for an engine mount of an automobile.

  For example, in a vehicle such as a passenger car, a vibration isolator as an engine mount is disposed between an engine that is a vibration generating unit and a vehicle body that is a vibration receiving unit. This vibration isolator attenuates the vibration, so that the transmission of vibration to the passenger compartment can be suppressed.

  In the vibration isolator, vibration is damped by arranging an elastic body between an inner cylinder and an outer cylinder which are vibration generating parts or vibration receiving parts. In recent years, for the purpose of improving manufacturing efficiency and reducing costs, a type in which the vibration receiving portion or the vibration generating portion and the elastic body are not bonded is used.

JP 2008-249032 A

  Patent Document 1 describes a vibration isolator in which an inner cylinder connected to a vibration generating unit side is press-fitted into a hole of an elastic body, and the elastic body is slidably held on an external body frame.

  In the vibration isolator configured in this way, when vibration is input from the vibration generating unit to the prevention device, the external body frame and the elastic body slide, and the sliding sound is transmitted as noise to the vehicle interior. There was an inconvenience.

  The present invention has been made in consideration of the above-described facts, and an object of the present invention is to provide a vibration isolator that suppresses noise transmission to the passenger compartment.

  The vibration isolator according to claim 1 of the present invention includes a first mounting member connected to the vibration generating unit side, a second mounting member connected to the vibration receiving unit side, and a sliding member relative to the first mounting member. An elastic body that is movably connected, fixed by pre-compression with respect to the second mounting member, and disposed non-adhered between the first mounting member and the second mounting member. It is characterized by that.

  In the vibration isolator according to claim 1 of the present invention, the elastic body and the second mounting member are not bonded but are fixed by pre-compression, and thus do not slide with each other. Accordingly, no sliding noise is generated between the second mounting member on the vibration receiving portion side and the elastic body at the time of vibration input, and transmission of the sliding noise into the vehicle interior is suppressed.

  On the other hand, since the first mounting member and the elastic body on the vibration generating unit side are slidably connected to each other, the stress concentration in the elastic body is suppressed, and the durability of the elastic body is improved.

  Here, as a configuration that enables the first mounting member and the elastic body to slide, a frictional force that acts between the elastic body and the first mounting member acts between the elastic body and the second mounting member. It is conceivable to make it smaller than the friction force.

  The term “connection” means that the members are in contact with each other in a state where vibration can be transmitted between the two members at least when vibration is input.

  The vibration isolator according to claim 2 of the present invention is the vibration isolator according to claim 1, wherein the elastic body is slidably held inside the first attachment member, and the second attachment is provided inside. The member is pre-compressed and fixed.

  In the vibration isolator according to claim 2 of the present invention, since the elastic body is slidably held inside the first mounting member on the vibration generating portion side, the elastic body slides with each other at the time of vibration input. Stress concentration is suppressed, and the durability of the elastic body is improved.

  On the other hand, since the second mounting member on the vibration receiving portion side is fixed to the inside of the elastic body by pre-compression, the elastic body and the second mounting member do not slide relative to each other at the time of vibration input, and a sliding sound is generated. Transmission to the passenger compartment is suppressed.

  The vibration isolator according to claim 3 of the present invention is the vibration isolator according to claim 1, wherein the elastic body slidably holds the first mounting member on the inside, and the second mounting member It is pre-compressed and fixed inside.

In the vibration isolator according to claim 3 of the present invention, since the first mounting member on the vibration generating side is slidably held inside the elastic body, the elastic body slides with each other when vibration is input. Stress concentration is suppressed, and the durability of the elastic body is improved.

  On the other hand, since the elastic body is fixed to the inside of the second mounting member on the vibration receiving portion side by pre-compression, the elastic body and the second mounting member do not slide relative to each other at the time of vibration input, and a sliding sound is generated. Transmission from the second mounting member to the passenger compartment is suppressed.

  A vibration isolator according to a fourth aspect of the present invention is the vibration isolator according to any one of the first to third aspects, wherein a low friction coating treatment is applied to the connection surface of the first mounting member to the elastic body. It is characterized by having been given.

  In the vibration isolator according to claim 4 of the present invention, the sliding surface of the first mounting member with respect to the elastic body can be achieved with a simple process by applying a low friction coating process to the connection surface of the first mounting member with respect to the elastic body. Can be improved. As a result, stress concentration on the elastic body can be reliably reduced, and the durability of the elastic body can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, in a non-adhesion type vibration isolator, it can suppress that a sliding sound is transmitted to the vibration receiving part side.

FIG. 3 is a sectional view taken along line 1-1 of FIG. It is a perspective view of the vibration isolator which concerns on embodiment of this invention. It is a perspective view of the rubber elastic body which concerns on embodiment of this invention.

  A vibration isolator according to an embodiment of the present invention will be described with reference to the drawings.

  In the present specification, “axis” means an axis of the vehicle body side inner cylinder 14 described later, and “axial direction” means an extending direction of the axis of the vehicle body side inner cylinder 14. Further, when used for an engine side bracket 12 and a rubber elastic body 16 which will be described later, the vehicle body side when the bracket 12 and the rubber elastic body 16 are integrally assembled to the vehicle body side inner cylinder 14 as the vibration isolator 10. It is expressed by the relationship with respect to the axis of the inner cylinder 14.

  Further, in the present embodiment, the “oval” in the axial direction view means that the end of the semicircle and the end of the semicircle are connected by a straight line, and the “axis” in the oval means both end portions. Means the one that passes through the midpoint of the line segment connecting the centers of the semicircles.

  The vibration isolator 10 is used, for example, as an engine mount in a vehicle, and attenuates and absorbs vibrations input from an engine that is a vibration generating unit to a vehicle body that is a vibration receiving unit, and suppresses vibration transmission to the vehicle body. It is.

  As shown in FIG. 1, the vibration isolator 10 includes a rubber elastic body 16 disposed between an engine side bracket (hereinafter referred to as “bracket”) 12 and a vehicle body side inner cylinder 14. The vibration isolator 10 is a non-adhesive type vibration isolator in which the bracket 12 and the rubber elastic body 16 and the rubber elastic body 16 and the vehicle body side inner cylinder 14 are not bonded to each other.

  The bracket 12 is a substantially rectangular body, and has an elliptical hole 18 in the thickness (axis) direction for inserting the rubber elastic body 16 shown in FIG.

  An annular convex portion 20 is formed on the upper portion of the hole portion 18 so as to be inserted into an annular concave portion 24 of the rubber elastic body 16 to be described later for locking the bracket 12.

  As shown in FIG. 3, the rubber elastic body 16 includes a cylindrical portion 22 that is oblong in the axial direction, an annular recess 24 that is formed on the upper side in the axial direction, and a flange portion 26 that is formed on the upper end in the axial direction. Prepare. The cylindrical portion 22 and the flange portion 26 are oval having the same shape when viewed in the axial direction. An annular recess 24 into which the annular projection 20 of the bracket 12 is inserted is formed between the cylindrical portion 22 and the flange portion 26. Furthermore, the rubber elastic body 16 is formed with a through hole 28 penetrating in the axial direction at the center.

  Further, the outer diameter of the rubber elastic body 16 is formed to be the same as the inner diameter of the hole 18 (excluding the annular convex portion 20) of the bracket 12. Therefore, even if the rubber elastic body 16 is inserted into the hole 18 of the bracket 12, the rubber elastic body 16 is not pre-compressed by the bracket 12. As a result, the bracket and the rubber elastic body 16 can slide with respect to each other.

  Further, the rubber elastic body 16 has a hole portion of the bracket 12 so that the extending direction of the flat portion 22A, which is an elliptical straight portion viewed in the axial direction, coincides with the main vibration direction (vehicle longitudinal direction in this embodiment) FR. 18, the bracket 12 and the rubber elastic body 16 can slide relative to each other in the main vibration direction FR.

  The bracket 12 is prevented from falling off the rubber elastic body 16 by inserting the annular convex portion 20 of the bracket 12 into the annular concave portion 24 of the rubber elastic body 16.

  The vehicle body side inner cylinder 14 has an outer diameter slightly larger than the inner diameter of the through hole 28 of the rubber elastic body 16, and is press-fitted (precompressed) into the through hole 28 and fixed. A bolt 32 is inserted into the through hole 30 of the vehicle body side inner cylinder 14. Therefore, the vehicle body side inner cylinder 14 disposed together with the rubber elastic body 16 between the vehicle body side upper bracket 34 and the vehicle body side lower bracket 36 is connected between the brackets 34 and 36 attached to the vehicle body side by fastening the nut 38. It is sandwiched between.

  The operation of the vibration isolator 10 thus configured will be described.

  When vibration is input from the engine side to the vibration isolator 10 via the bracket 12, the vibration input from the bracket 12 is attenuated and absorbed by the rubber elastic body 16, and the vehicle body-side inner cylinder 14 and the brackets 34 and 36 are used for the vehicle. Transmission to the room is suppressed.

  At this time, since the rubber elastic body 16 and the bracket 12 are configured to be slidable, for example, they slide relative to each other along the axial direction to absorb and attenuate vibrations.

  In particular, when vibration in the main vibration (vehicle body front-rear) direction FR is input to the vibration isolator 10, the planar portion 22A of the rubber elastic body 16 is disposed along the main vibration direction FR. And the rubber elastic body 16 slide well with each other to efficiently absorb and attenuate vibrations.

  Further, since the rubber elastic body 16 and the bracket 12 are slidable with each other, stress concentration on the rubber elastic body 16 can be suppressed, and the durability of the rubber elastic body 16 can be improved.

  On the other hand, since the vehicle body side inner cylinder 14 is press-fitted (precompressed) into the through hole 28 of the rubber elastic body 16 and fixed, when the vibration is input, the vehicle body side inner cylinder 14 and the rubber elastic body 16 are not. Even if they are bonded, they do not slide on each other. Therefore, it is possible to prevent the sliding sound of the vehicle body side inner cylinder 14 and the rubber elastic body 16 from being transmitted as noise to the vehicle interior. That is, the ride comfort of the vehicle occupant can be improved.

[Other Embodiments]

  In the above embodiment, the rubber elastic body 16 and the vehicle body side inner cylinder 14 are fixed by pre-compression, and the rubber elastic body 16 and the bracket 12 can be slid without pre-compression. Although the effect | action of this invention was achieved, it is not restricted to this.

  That is, the bracket 12 and the rubber elastic body 16 are configured to be slidable so that the friction force acting between the vehicle body side inner cylinder 14 and the rubber elastic body 16 acts between the bracket 12 and the rubber elastic body 16. Any configuration may be used as long as it is a non-adhesive configuration in which the frictional force is reduced.

  Therefore, for example, even when the rubber elastic body 16 is pre-compressed and inserted into the hole 18 of the bracket 12, the vehicle body side inner cylinder 14 and the rubber elastic body 16 are press-fitted into the through hole 28 of the rubber elastic body 16. If the frictional force acting on the bracket 12 and the rubber elastic body 16 is smaller than the acting frictional force, the bracket 12 and the rubber elastic body 16 can be slidable.

  Further, as a method of reducing the frictional force acting between the bracket 12 and the rubber elastic body 16, from the beginning of the manufacture of the bracket 12, the inner peripheral surface of the hole portion 18 of the bracket 12 with which the rubber elastic body 16 abuts upon vibration input. It is also conceivable to perform a low friction coating process that reduces the friction coefficient of the surface of the hole 18. For example, a coating process that includes a lubricating material such as a fluororesin or molybdenum disulfide.

  Thereby, the frictional force between the bracket 12 and the rubber elastic body 16 can be reduced more simply than the frictional force between the rubber elastic body 16 and the vehicle body side inner cylinder 14 so that both can be slid.

  In the above embodiment, the vehicle body side inner cylinder 14 is press-fitted and fixed to the hole 18 of the rubber elastic body 16 so that the vehicle body side inner cylinder 14 does not slide with respect to the rubber elastic body 16 when vibration is input. However, as long as the pre-compression is applied between the vehicle body side inner cylinder 14 and the rubber elastic body 16, the mode is not limited. For example, it is conceivable that pre-compression is applied by inserting the vehicle body side inner cylinder 14 in a state in which the diameter of the through hole 28 of the rubber elastic body 16 is expanded.

  In the present embodiment, the vehicle body side that is the vibration receiving portion is the vehicle body side inner cylinder 14 and the engine side that is the vibration generating portion is the bracket 12, but the reverse is also possible. In this case, the bracket 12 and the rubber elastic body 16 may be fixed, and the rubber elastic body 16 and the vehicle body side inner cylinder 14 may be slidable.

  In the present embodiment, the rubber elastic body 16 (and the hole 18 of the bracket 12) has an oval shape when viewed in the axial direction, but the present invention is not limited to this. For example, it may be circular or other shapes in the axial direction view. Moreover, although the cylindrical part 22 and the flange part 26 were made into the same shape in the axial direction view, it is not limited to this, It is good also as a different shape.

10 Vibration isolator 12 Bracket (first mounting member)
14 Inner cylinder (second mounting member)
16 Rubber elastic body (elastic body)
18 holes (connection surface)

Claims (4)

A first attachment member coupled to the vibration generating unit side;
A second attachment member coupled to the vibration receiving portion side;
It is slidably connected to the first mounting member, fixed to the second mounting member with pre-compression, and non-adhered between the first mounting member and the second mounting member. An established elastic body,
An anti-vibration device comprising:   The vibration isolator according to claim 1, wherein the elastic body is slidably held inside the first mounting member, and the second mounting member is pre-compressed and fixed inside.   The vibration isolator according to claim 1, wherein the elastic body holds the first mounting member slidably on the inner side and is pre-compressed and fixed on the inner side of the second mounting member.   The vibration isolator according to any one of claims 1 to 3, wherein a connection surface of the first mounting member to the elastic body is subjected to a low friction coating process.

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