JP3893979B2 - Cylindrical vibration isolator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cylindrical vibration isolator that is suitably used, for example, as a vehicle differential mount or engine mount.
[0002]
[Prior art]
Conventionally, for example, when a differential is mounted on a vehicle, a cylindrical vibration isolator such as a diff mount that supports the differential on the vehicle body is used. As such a cylindrical vibration isolator, as shown in FIGS. 7 and 8, a main shaft member 5 formed in a cylindrical shape and fitted with an annular stopper 51 at the center portion of the outer peripheral surface thereof, and on the outer side of the main shaft member 5. The outer cylinder member 6 disposed substantially coaxially at a distance, and the main shaft member 5 and the outer cylinder member 6 are interposed between the main cylinder member 6 and the main cylinder member in the radial main vibration input direction. 5, a rubber elastic body 7 having a pair of stems 71 and 72 penetrating in the axial direction provided on both sides of the shaft 5, a mounting base 81 held at one end of the main shaft member 5, and extending from the mounting base 81 in the axial direction. A rubber elastic stopper member 8 (see FIG. 9 and FIG. 10) is inserted and arranged in one curb 71 of the rubber elastic body 7 and has a stopper portion 84 having a circular cross section in the direction perpendicular to the axis. Things are known.
[0003]
This cylindrical vibration isolator is attached and used by connecting and fixing the main shaft member 5 to one of the mounting portions of the vehicle body and the differential, and connecting and fixing the outer cylinder member 6 to one of the other mounting portions. Is done. In this case, the rubber elastic body 6 is attached so that the pair of straights 71 and 72 are positioned at a position along the main vibration input direction (the differential load input direction) in the radial direction of the cylindrical vibration isolator. 7 and 8 are attached so that the main vibration input direction is the vertical direction in the figure, and the differential load is applied to the main shaft member 5. .
[0004]
When vibration is input to the cylindrical vibration isolator, the rubber elastic body 7 interposed between the main shaft member 5 and the outer cylinder member 6 is elastically deformed, so that the vibration is effectively damped. . At this time, since the rubber elastic body 7 is provided with the pair of curls 71 and 72, the compressive strain and the tensile strain of the rubber elastic body 7 are alleviated, thereby improving the durability of the rubber elastic body 7. ing. In addition, since this cylindrical vibration isolator usually has a large amount of differential movement, the excessive elastic displacement between the main shaft member 5 and the outer cylinder member 6 is restricted to ensure the durability of the rubber elastic body 7. In addition to the annular stopper 51 fitted to the main shaft member 5, an elastic stopper member 8 into which a stopper portion 84 is inserted and disposed in the straight 71 is also provided.
[0005]
[Problems to be solved by the invention]
By the way, the stopper portion 82 of the elastic stopper member 8 is formed in accordance with the curved surface shape of the spindle 71 on the main shaft member 5 side and the outer cylinder member 6 side, and the cross-sectional shape in the circumferential direction is usually substantially constant. It is formed to have an arc shape. When a large vibration is input to the cylindrical vibration isolator, the stopper portion 84 and the rubber elastic body 7 are strongly pressed against each other, so that there is a high possibility that abnormal noise is generated. Or by applying silicon to suppress the generation of abnormal noise.
[0006]
However, since the embossing cannot be performed directly on the elastic stopper member 8 by machining, the die is very expensive because the elastic stopper member 8 is manually processed on the mold for vulcanization molding. This has led to an increase in costs. Also, when silicon is applied, the cost is inevitable because silicon is expensive.
[0007]
The present invention has been made in view of the above circumstances, and it is an object to be solved to provide a cylindrical vibration isolator capable of realizing a measure for suppressing abnormal noise generation at low cost.
[0008]
[Means for solving the problems, actions and effects of the invention]
The cylindrical vibration isolator according to the first aspect of the present invention that solves the above-described problem includes a main shaft member, an outer cylindrical member that is disposed substantially coaxially at a distance to the outside of the main shaft member, and the main shaft member. A rubber elastic body having a straightness penetrating in the axial direction, which is interposed between the outer cylinder member and integrally connecting the two, a mounting base held at one end of the main shaft member, and an axial direction from the mounting base And an elastic stopper member having a stopper portion having a circular cross section in the direction perpendicular to the axis, the elastic stopper member including The stopper portion of the member extends in a circumferential direction from the center portion toward both ends on a plane perpendicular to the axis, and is formed so as to gradually increase greatly toward the outer peripheral side or the inner peripheral side toward the both ends. Adopting means to have By that.
[0009]
In the cylindrical vibration isolator of the present invention, when a large radial vibration is input to the cylindrical vibration isolator, the main shaft member and the outer cylinder member move relative to each other in the radial direction so that the rubber elastic body Elastically deforms. As a result, an excessive relative displacement between the main shaft member and the outer cylinder member is caused when the stopper portion of the elastic stopper member inserted and arranged in the rubber elastic body is sandwiched and compressed by the rubber wall of the rubber elastic body. Is elastically regulated.
[0010]
At this time, the raised portion provided in the stopper portion is formed so as to gradually increase toward the outer peripheral side or the inner peripheral side toward the both ends, so that both ends of the raised portion are directed toward the central portion. It touches the wall surface in turn. Therefore, the surface of the stopper portion on which the bulging portion protrudes, the bulging portion first abuts against the wall surface, and the bulging portion abuts stepwise from both ends toward the central portion. Does not touch. This reliably reduces abnormal noise that is likely to occur when large vibrations are input.
[0011]
In addition, since the protruding part in the present invention can be easily formed when the elastic stopper member is formed by vulcanization molding, it is possible to avoid a significant increase in cost.
[0012]
Therefore, since the cylindrical vibration isolator of the present invention is provided with the above-described raised portion in the stopper portion of the elastic stopper member, it is possible to realize a measure for suppressing the occurrence of abnormal noise at a low cost.
[0013]
In the elastic stopper member according to the present invention, at least the stopper portion is formed of an elastic body such as rubber or resin. The hardness of the stopper portion is set in accordance with the hardness of the rubber elastic body having the straightness where the stopper portion is inserted and arranged. The raised portion provided in the stopper portion extends in the circumferential direction from the central portion toward both ends on a plane perpendicular to the axis, and is formed so as to gradually increase toward the outer peripheral side or the inner peripheral side toward the both ends. Therefore, it is provided so as to be paired on both sides of the central portion. One or a plurality of the raised portions may be provided in the axial direction of the stopper portion.
[0014]
And the cylindrical vibration isolator which concerns on invention of Claim 2 WHEREIN: The invention of Claim 1 WHEREIN: The said protruding part has the circular-arc-shaped cross-sectional shape formed with the bending rate different from the bending rate of the said stopper part. The means of having is adopted.
[0015]
According to this means, the raised portion provided in the stopper portion can be set by an easy method. In addition, if the bending rate of a protruding part is made smaller than the bending rate of a stopper part, a protruding part will be formed so that it may protrude to the outer peripheral side of a stopper part. On the contrary, if the bending rate of the raised portion is larger than the bending rate of the stopper portion, the raised portion is formed so as to rise toward the inner peripheral side of the stopper portion.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
FIG. 1 is a cross-sectional view taken along the direction perpendicular to the axis of the cylindrical vibration isolator according to the present embodiment, and is a cross-sectional view taken along the line I-I in FIG. 2, and FIG. FIG. 2 is a cross-sectional view taken along line II-II in FIG.
[0018]
The cylindrical vibration isolator according to the present embodiment is used as a differential mount. As shown in FIGS. 1 and 2, the main shaft member 1 having an annular stopper 11 and the outer side of the main shaft member 1 are spaced apart from each other. A rubber elastic body 3 having a pair of straight edges 31 and 32 which are interposed between the outer cylinder member 2 and the main shaft member 1 and the outer cylinder member 2 which are coaxially arranged apart from each other and which penetrate in the axial direction; And an elastic stopper member 4 having a stopper portion 44 provided with 45. 1 and 2, the main shaft member 1 is connected and fixed to the differential mounting portion, and the outer cylinder member 6 is connected and fixed to the vehicle body mounting portion. Is shown in a state in which the main shaft member 1 is loaded.
[0019]
The main shaft member 1 is formed of a ferrous metal into a thick cylindrical shape. An annular stopper 11 is fitted to the central portion of the outer peripheral surface of the main shaft member 1 so as to protrude radially outward from the outer peripheral surface of the main shaft member 1.
[0020]
The outer cylinder member 2 is formed in a cylindrical shape by an iron-based metal plate, has an inner diameter that is larger than the outer diameter of the main shaft bracket 1, and is formed to be slightly shorter than the main shaft bracket 1. The outer cylinder member 2 is disposed substantially coaxially at a distance from the outside of the main shaft member 1. In this case, the main shaft member 1 and the outer cylinder member 2 are slightly decentered in the vertical direction in the figure because the main shaft member 1 is loaded with a differential load.
[0021]
The rubber elastic body 3 is formed in a substantially cylindrical shape by integrally vulcanizing a rubber material together with the main shaft fitting 1 and the outer cylinder member 2. The rubber elastic body 3 is vulcanized and bonded to the outer peripheral surface of the main shaft 1 and the inner peripheral surface of the outer cylindrical member 2, and is interposed between the two to integrally connect them. A pair of straight edges 31, 32 penetrating in the axial direction and having an arcuate cross section are provided at both side positions of the main shaft 1 in the radial direction of the rubber elastic body 3 so as to be axially symmetric.
[0022]
The elastic stopper member 4 is integrally formed by vulcanization molding of a rubber material. As shown in FIGS. 3 and 4, the elastic stopper member 4 extends in an axial direction from an oblong mounting base 41 having a circular mounting hole 42 at the center thereof, and one end of the mounting base 41. The cross-sectional shape in the direction perpendicular to the axis includes a stopper portion 44 formed in an arc shape with a substantially constant thickness. The stopper portion 44 is formed in accordance with the curved shapes of the main shaft member 1 side and the outer cylinder member 2 side of the straight 31 provided on the rubber elastic body 3. A central portion of the stopper portion 44 in the axial direction is formed so as to extend in the circumferential direction from the central portion toward both ends on a plane perpendicular to the shaft, and gradually increase toward the outer peripheral side toward both ends. A raised portion 45 is provided. The raised portion 45 has an arc-shaped cross-sectional shape with a substantially constant thickness formed at a bending rate smaller than the bending rate of the stopper portion 44 on a plane perpendicular to the axis . Thereby, a concave portion 46 formed by a difference in bending rate between the stopper portion 44 and the raised portion 45 is formed at a portion where the raised portion 45 on the inner peripheral surface of the stopper portion 44 is provided.
[0023]
As shown in FIGS. 1 and 2, the elastic stopper member 4 has the mounting hole 42 of the mounting base 41 in the state where the stopper 44 is inserted and disposed in one curl 31 of the rubber elastic body 3. It is attached by being fitted and fixed to the outer periphery of the one end portion. In this case, the stopper portion 44 inserted and arranged in the curb 31 has a circumferential central portion of the inner peripheral surface thereof in contact with the inner wall surface of the curb 31 and both circumferential ends of the raised portion 45 of the outer peripheral surface of the curb 31. The state is in contact with the outer wall surface.
[0024]
The cylindrical vibration damping device of the present embodiment configured as described above is attached by connecting and fixing the main shaft member 1 to the differential mounting portion and connecting and fixing the outer cylinder member 6 to the mounting portion of the vehicle body. 1 and FIG. 2 are obtained. In this case, the main vibration input direction (the differential load input direction) in the radial direction to the cylindrical vibration isolator is the vertical direction in the figure.
[0025]
When a large radial vibration is input to the cylindrical vibration isolator, the main shaft member 1 and the outer cylindrical member 2 are relatively moved in the radial direction, and the rubber elastic body 3 is elastically deformed. As a result, the stopper portion 44 of the elastic stopper member 4 inserted and arranged in the curb 31 of the rubber elastic body 3 is sandwiched and compressed by the wall surface of the curb 31 of the rubber elastic body 3, so that the main shaft member 1 and the outer cylinder are compressed. Excessive relative displacement with the member 2 is elastically restricted.
[0026]
At this time, the raised portion 45 provided on the stopper portion 44 is formed so as to gradually increase toward the outer periphery as it goes to both ends, so in order from the both ends of the raised portion 45 toward the center portion. Immediately abuts against the wall surface. Accordingly, the surface of the stopper portion 44 on the side where the raised portion 45 protrudes is because the raised portion 45 first abuts against the wall surface 31 and the raised portion 45 abuts stepwise from both ends toward the central portion. The whole surface does not contact at the same time. This reliably reduces abnormal noise that is likely to occur when large vibrations are input.
[0027]
In addition, since the raised part 45 provided in the stopper part 44 can be easily formed when the elastic stopper member 4 is formed by vulcanization molding, a significant increase in cost can be avoided.
[0028]
As described above, in the cylindrical vibration isolator according to the present embodiment, the raised portion 45 as described above is provided in the stopper portion 44 of the elastic stopper member 4, so that a measure for suppressing the occurrence of abnormal noise is realized at low cost. can do.
[0029]
In addition, the raised portion 45 provided in the stopper portion 44 of the present embodiment is formed to have an arc-shaped cross-sectional shape with a bending rate different from the bending rate of the stopper portion 44, and thus the raised portion 45 can be easily formed. It can be set by a method.
[0030]
The raised portion 45 of the present embodiment is formed so that the raised portion 45 is raised to the outer peripheral side of the stopper portion 44 by making it smaller than the bending rate of the stopper portion 44, but FIG. 5 and FIG. Like the elastic stopper member 4a shown, the bending rate of the raised portion 45a may be made larger than the bending rate of the stopper portion 44a so that the raised portion 45a rises toward the inner peripheral side of the stopper portion 44a. Even in this case, the same effect as in the case of the above embodiment can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view taken along a direction perpendicular to the axis of a cylindrical vibration isolator according to an embodiment of the present invention, and is a cross-sectional view taken along the line II in FIG.
FIG. 2 is a cross-sectional view taken along the axial direction of the cylindrical vibration isolator according to the embodiment of the present invention, and is a cross-sectional view taken along the line II-II in FIG.
FIG. 3 is a front view of the elastic stopper member according to the embodiment of the present invention viewed from the axial direction.
FIG. 4 is a side view of an elastic stopper member according to an embodiment of the present invention.
FIG. 5 is a front view of an elastic stopper member according to a modification of the present invention viewed from the axial direction.
FIG. 6 is a side view of an elastic stopper member according to a modification of the present invention.
7 is a cross-sectional view taken along a direction perpendicular to the axis of a conventional cylindrical vibration isolator, and is a cross-sectional view taken along the line VII-VII in FIG.
8 is a cross-sectional view taken along the axial direction of a conventional cylindrical vibration isolator, and is a cross-sectional view taken along the line VIII-VIII in FIG.
FIG. 9 is a front view of a conventional elastic stopper member as viewed from the axial direction.
10 is a cross-sectional view taken along the axial direction of a conventional elastic stopper member, and is a cross-sectional view taken along line XX in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 5 ... Main shaft member 2, 6 ... Outer cylinder member 3, 7 ... Rubber elastic body 4, 4a, 8 ... Elastic stopper member 11, 51 ... Annular stopper 31, 32, 71, 72 ... Straight 41, 81 ... Mounting base 42 ... Mounting hole 44, 44a, 84 ... Stopper portion 45, 45a ... Raised portion 46 ... Recessed portion

Claims (2)

A main shaft member;
An outer cylinder member disposed substantially coaxially at a distance from the outside of the main shaft member;
A rubber elastic body having a straightness penetrating in the axial direction;
A mounting base portion held at one end of the main shaft member, and a stopper portion extending in the axial direction from the mounting base portion and inserted into the straight portion of the rubber elastic body, and having a circular arc cross-sectional shape in the direction perpendicular to the axis. In a cylindrical vibration isolator provided with an elastic stopper member,
The stopper portion of the elastic stopper member is formed so as to extend in the circumferential direction from the central portion toward both ends on a plane perpendicular to the axis, and gradually increase toward the outer peripheral side or the inner peripheral side toward the both ends. A cylindrical vibration isolator having a raised portion.   The cylindrical vibration isolator according to claim 1, wherein the raised portion has an arcuate cross-sectional shape formed at a bending rate different from the bending rate of the stopper portion.

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