JP4188116B2 - Vibration isolator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vibration isolator suitable for an engine mount or the like, and more particularly, to a device provided with a stopper and having reduced contact sound between the stopper and the vibration isolating rubber.
[0002]
[Prior art]
Various types of vibration isolator used for engine mounts and the like are known. For example, a cylindrical bush type engine mount has an anti-vibration rubber between the inner cylinder 1 and the outer cylinder 2 as schematically shown in FIG. 3, the stopper 4 is projected from the outer cylinder 2 side toward the inner cylinder 1 side, and when the inner cylinder 1 is excessively displaced downward, this is received by the stopper 4.
[0003]
[Patent Document 1]
JP-A-7-169642 [Patent Document 2]
Japanese Patent Laid-Open No. 2000-46097
[Problems to be solved by the invention]
In FIG. 8, when this engine mount is arranged so that the left-right direction of the figure is the front-rear direction of the vehicle, a large load is applied to the inner cylinder 1 at the time of large vibration, so that not only the vertical direction of the figure but also If it is greatly displaced in various directions substantially perpendicular to each other, a part of the anti-vibration rubber 3 may come into contact with the upper surface of the stopper 4 as indicated by a virtual line, and noise may be generated due to friction.
Therefore, it is desired to reduce the generation of abnormal noise due to such contact between the stopper 4 and the vibration isolating rubber 3, and the present invention aims to realize this requirement.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention of claim 1 is a vibration isolator in which a first attachment member attached to the vibration source side and a second attachment member attached to the vibration receiving side are connected by an anti-vibration rubber.
A liquid chamber is provided in the anti-vibration rubber, and a stopper that protrudes from one side of the first mounting member or the second mounting member to the other side is provided in the liquid chamber,
This stopper has a substantially trapezoidal shape including a receiving surface as a top and a side surface provided around the receiving surface, and a plurality of formed from the receiving surface to the side surface across the corner portion of the receiving surface and the side surface. a groove is provided, wherein the friction reducing unit is formed on the portion contacting vibration isolating rubber and including at least the corner portion of the surface of the stopper by the plurality of grooves, when the vibration isolating rubber is in contact with the corner portion, a corner The working liquid is allowed to escape by a groove straddling the part .
[0006]
According to a second aspect of the present invention, in the first aspect of the invention, the friction reducing portion has a contact area reducing structure by unevenness.
[0007]
According to a third aspect of the present invention, in the first or second aspect, the stopper has a substantially trapezoidal shape including a receiving surface and a side surface which are top portions, and the friction reducing portion is formed at a corner portion of the receiving surface and the side surface. It is characterized by that.
[0008]
According to a fourth aspect of the present invention, in the third aspect of the invention, the friction reducing portion includes a plurality of grooves formed across the corner portion.
[0009]
According to a fifth aspect of the present invention, in the first aspect, the first mounting member is an inner cylinder, and the second mounting member is an outer cylinder that surrounds the inner cylinder. And the stopper protrudes from the outer cylinder side to the inner cylinder side.
[0010]
【The invention's effect】
According to the first aspect of the present invention, since the friction reducing portion is provided in the stopper, when the anti-vibration rubber contacts the stopper, the friction is reduced and the generation of abnormal noise can be reduced.
[0011]
According to the second aspect of the present invention, since the contact area reducing structure made of unevenness is provided on the stopper, the friction reducing portion can be easily formed.
[0012]
According to the third aspect, since the stopper is substantially trapezoidal and the friction reducing portion is provided at the corner portion thereof, the friction at the time of contact at the corner portion where the anti-vibration rubber first comes into contact is reduced, and the abnormal noise is efficiently generated. Generation can be reduced.
[0013]
According to the fourth aspect, since the friction reducing portion according to the third aspect is configured by the groove straddling the corner portion, the friction reducing portion can be easily provided on the corner portion.
[0014]
According to the fifth aspect, the present invention can be easily applied to a cylindrical bush mount provided with a stopper.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment applied to an automotive cylindrical bush type engine mount will be described with reference to the drawings. 1 is a front view of the engine mount, FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1, FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. 5, and FIG. 7 is a cross-sectional view taken along line 7-7 in FIG.
[0016]
First, in FIGS. 1 to 3, the engine mount 10 includes an inner cylinder 11, an outer cylinder 12 that surrounds the inner cylinder 11, and a vibration isolating rubber 13 that connects between them. The inner cylinder 11 is a pipe-like member made of an appropriate rigid material such as metal, and is attached to an engine (not shown) which is a vibration source by a connecting member (not shown) such as a bolt passed through the hollow portion. The inner cylinder 11 forms a first attachment member.
[0017]
The outer cylinder 12 is a cylindrical member made of a suitably rigid material such as metal, and includes the outer cylinder 12 in an eccentric position and is attached to a vehicle body on the vibration receiving side (not shown) by a bracket 15. The outer cylinder 12 forms a second attachment member.
[0018]
In this embodiment, in the state shown in FIG. 1, the vertical direction is the vertical direction of the vehicle body, and this direction is the main vibration input direction Z for the engine mount 10. The left-right direction is the front-rear direction X of the vehicle body, and the left side of the figure is the front side of the vehicle body and the right side is the rear side of the vehicle body. In addition, let the axial direction of the inner cylinder 11 be a Y direction. The Y direction is the left-right direction of the vehicle body, and it is assumed that the left side in FIG. 2 is the left side of the vehicle and the right side is the right side of the vehicle.
[0019]
The anti-vibration rubber 13 is made of a known rubber-like material such as natural or synthetic, and floats and supports the inner cylinder 11 with respect to the outer cylinder 12 to exhibit a predetermined spring elasticity. Above the inner cylinder 11, a curb 16 penetrating in the axial direction of the inner cylinder 11 is formed, and a diaphragm 17 is formed on the inner surface of the outer cylinder 12 facing the inner cylinder 11 across the curb 16.
[0020]
Below the curb 16, left and right side walls 18 are formed. As shown in FIG. 2, a main liquid chamber 20 is formed between the side walls 18, and an incompressible known working liquid is sealed therein. A stopper 14 having a substantially trapezoidal shape in the cross section in the Y-axis direction in FIG. 2 is provided in the main liquid chamber 20 so as to protrude from the outer cylinder 12 toward the inner cylinder 11, and when the inner cylinder 11 is excessively displaced downward, It is supposed to take it.
[0021]
The diaphragm 17 defines a sub liquid chamber 21 between the inner surface of the outer cylinder 12 above the tick 16 and expands and contracts into the tick 16 to compensate for the volume change of the sub liquid chamber 21. Although it is a flexible member formed integrally with the rubber 13, it has a spring elasticity that is negligibly small as a rubber spring that constitutes the engine mount 10.
[0022]
The secondary liquid chamber 21 communicates with the main liquid chamber 20 through the orifice passage 22, and the liquid moves between the main liquid chamber 20 and the secondary liquid chamber 21 due to the volume change of the main liquid chamber 20 caused by the vertical movement of the inner cylinder 11. By flowing, the liquid column resonates at a predetermined vibration frequency in the orifice passage 22. The orifice passage 22 is a known damped orifice passage having a resonance point in a low frequency region.
[0023]
As is apparent from FIG. 3, the orifice passage 22 is formed between the inner peripheral surface of the outer cylinder 12 by the groove 23 formed in the outer peripheral portion of the stopper 14 and the groove 24 formed in the outer peripheral portion of the vibration isolating rubber 13. Is done.
[0024]
The anti-vibration rubber 13 includes an arm portion 25 that extends from the inner cylinder 11 back and forth in a cross section orthogonal to the axis of the inner cylinder 11 shown in FIG. The upper surface of the arm portion 25 faces the curb 16 and the lower surface faces the main liquid chamber 20. The left and right ends of the arm portion 25 are continuous with the side wall 18, and the arm portion 25 and the side wall 18 form an elastic wall portion of the main liquid chamber 20.
[0025]
The arm portion 25 is a main portion as an anti-vibration rubber that receives a load mainly due to elastic deformation in the shear direction, and its radially outer peripheral end portion in FIG. 3 is continuous with the outer peripheral portion 26, and the outer peripheral portion 26 has a diaphragm. It continues to 17. The anti-vibration rubber 13 includes a diaphragm 17, a side wall 18, an arm portion 25, and an outer peripheral portion 26 that are integrally formed continuously. The groove 24 is formed in the outer peripheral portion of the outer peripheral portion 26.
[0026]
Further, a covering portion 27 is formed around the inner cylinder 11 from the radially inner peripheral end portion of the arm portion 25, and a lower portion thereof serves as an upper stopper 28 protruding into the main liquid chamber 20. .
[0027]
The stopper 14 is arranged in the main liquid chamber 20 so as to form an interval between the side wall 18 and the determination in the illustrated initial state. However, when there is a large load input from the engine side to the inner cylinder 11 and the inner cylinder 11 is displaced downward and sinks greatly, the stopper 14 contacts the upper stopper 28 and receives it. Also, when the side wall 18 is greatly deformed in the left-right direction as indicated by the phantom line in FIG. 2 due to a large displacement in the axial direction of the inner cylinder 11 or when the gear is changed from forward to reverse, one of the arm portions 25 is When sinking and deforming like the phantom line in FIG. 4, the side wall 18 and the arm portion 25 come into contact with the stopper 14.
[0028]
As shown in FIGS. 4 to 7, the stopper 14 is made of a material having appropriate rigidity such as 6-6 nylon, and is formed integrally with the stopper main body 30 protruding into the main liquid chamber and the outer cylinder 12. And an arcuate outer peripheral portion 31 along the inner surface. The upper surface of the stopper main body 30 is substantially flat perpendicular to the Z direction, forms a receiving surface 32 for receiving the inner cylinder 11, and further includes left and right side surfaces 33 parallel to the right in the Z direction. However, the front and rear side surfaces 34 are relatively gentle slopes of about 45 ° (FIG. 4).
[0029]
4 and 5, the groove 36 extends from the receiving surface 32 to the left and right side surfaces 33 across the left and right corner portions 35 (see FIG. 7) extending in the longitudinal direction between the receiving surface 32 and the left and right side surfaces 33. A groove 36 is formed. A plurality and a suitable number of the grooves 36 are formed in the longitudinal direction along the corner portion 35 at the same time when the stopper 14 is formed, or are formed by machining afterward, and the central portion of the upper surface is discontinuous. However, it is optional to make it continuous. Due to the groove 36, the receiving surface 32 of the stopper 14 is uneven to form a contact area reducing structure.
[0030]
The stopper main body 30 is formed with a through hole 38 extending in the left and right directions on the front and rear sides of the central column portion 37. Further, as apparent in FIG. 5, notches 39 and 40 are formed in the center in the width direction at both ends in the circumferential direction of the arc-shaped outer peripheral portion 31, and the rear notch 40 is more than the front notch 39. It is getting bigger.
[0031]
As shown in FIG. 6, positioning protrusions 41 projecting substantially upward are formed at both ends of the rear notch 40 so as to be fitted and positioned with the lower end portion of the outer peripheral portion 26 of the vibration-proof rubber 13. ing.
[0032]
As shown in FIG. 7, a groove 23 having a substantially U-shaped cross section released outward is formed on the outer peripheral surface of the arc-shaped outer peripheral portion 31, and both ends in the longitudinal direction reach notches 39 and 40. The rear cutout 40 further communicates with the groove 24 to form an orifice passage 22 that communicates the main liquid chamber 20 and the sub liquid chamber 21.
5 and 6, the front notch 39 fits the front outer peripheral portion 26. Since the groove 24 is not formed in the outer peripheral portion 26 fitted into the notch 39, the orifice passage 22 stops here.
[0033]
Next, the operation of this embodiment will be described. In FIG. 3, when a large load is input to the inner cylinder 11 from the engine side and the inner cylinder 11 is excessively displaced downward, the inner cylinder 11 is received by the stopper 14. At this time, the upper stopper 28 comes into contact with the receiving surface 32, so that the impact is alleviated.
[0034]
Further, as shown in FIG. 2, a large load in the left-right direction is applied to the inner cylinder 11, and when the side wall 18 is greatly deformed as indicated by an imaginary line, it contacts the corner portion 35. At this time, a groove 36 is formed in the corner portion 35 from the receiving surface 32 to the left and right side surfaces 33, and the upper portion of the stopper main body 30 has a structure for reducing the contact area by the groove 36. Thus, friction at the time of contact with the side wall 18 is reduced, and generation of abnormal noise can be reduced.
[0035]
Moreover, since the stopper 14 has a substantially trapezoidal shape and a friction reducing portion is provided at the corner portion 35, the friction at the time of contact can be reduced at the corner portion 35 where the side wall 18 of the vibration isolating rubber 13 first contacts. Further, since the stopper main body portion 30 is provided with a contact area reducing structure made of unevenness by the groove 36, the friction reducing portion can be easily formed. In addition, the groove 36 straddling the corner portion 35 makes it easy for the working liquid to escape between the side wall 18 and the flow of the working liquid can be smoothed.
[0036]
Further, the collision between the stopper main body 30 and the side wall 18 can be mitigated, and the occurrence of hitting sound is further reduced. In addition, in the cylindrical bush mount provided with the stopper 14, it is only necessary to make a slight process or change on the surface side of the stopper 14, so that the cylindrical bush mount of the liquid seal type or the non-liquid seal type is used. Easy to apply.
[0037]
Further, if the groove 36 is formed on the front and rear end portions of the receiving surface 32 toward the front and rear side surfaces 34, the frictional noise at the time of contact with the arm portion 25 can be reduced. Such a contact may occur when the front and rear sides of the arm portion 25 are excessively displaced so as to sink in a gear change or the like from the forward side to the reverse side.
[0038]
In addition, this invention is not limited to the said Example, A various deformation | transformation and application are possible, for example, a friction reduction part is also possible by forming the surface with a suitable lubricant. Even when the structure for reducing the contact area is adopted, not only the formation of the grooves but also the projections and depressions may be formed by providing projections such as dots or ridges.
[0039]
In addition, at least the receiving surface 32 side of the stopper 14 may be formed of an elastic member. In this way, the generation of abnormal noise during contact can be alleviated. In this case, the receiving surface 32 can be made of the same kind or different kind of rubber from the anti-vibration rubber 13 or an elastic elastomer. However, the stopper main body 30 may also be integrally formed as an elastic body.
[0040]
Moreover, when the receiving surface 32 is used as an elastic body and the groove 36 is provided here, when the inner cylinder 11 is received, the portion is first compressed relatively easily around the groove 36, and then the entire receiving surface 32 is fully compressed. Since it is compressed, the amount of compression changes stepwise according to the amount of displacement on the inner cylinder 11 side, so that the stopper 14 can receive and receive a non-linear spring constant.
[0041]
Further, the vibration isolator may be either a liquid seal type or a non-liquid seal type. Moreover, it can be applied not only to the cylindrical bush type but also to various known types such as a conical mount. In addition, it can be used not only for engine mounts but also for suspensions and the like, and can also be applied to various uses other than automobiles. Further, the stopper may be provided so as to protrude from the reverse first mounting member side to the second mounting member side.
[Brief description of the drawings]
1 is a front view of an engine mount according to an embodiment. FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. ] Top view of stopper [FIG. 6] Sectional view taken along line 6-6 in FIG. 5 [FIG. 7] Sectional view taken along line 7-7 in FIG.
10: Engine mount, 11: Inner cylinder, 12: Outer cylinder, 13: Anti-vibration rubber, 14: Stopper, 20: Main liquid chamber, 21: Sub liquid chamber, 22: Orifice passage, 30: Stopper body, 32: Receiving surface, 33: Left and right side surfaces, 35: Corner part, 36: Groove

Claims (4)

In the vibration isolator in which the first attachment member attached to the vibration source side and the second attachment member attached to the vibration receiver side are connected by an anti-vibration rubber,
A liquid chamber in which a working liquid is sealed in the vibration isolating rubber is provided, and a stopper that protrudes from one side of the first mounting member or the second mounting member to the other side is provided in the liquid chamber,
This stopper has a substantially trapezoidal shape including a receiving surface which is a top portion and a side surface provided around the receiving surface, and a plurality of formed from the receiving surface to the side surface across the corner portion of the receiving surface and the side surface. A groove is provided, and a friction reducing portion is formed in a portion of the stopper surface that comes into contact with the anti-vibration rubber including at least the corner portion by the plurality of grooves, and when the anti-vibration rubber contacts the corner portion, the corner An anti-vibration device characterized in that the working liquid is allowed to escape by a groove straddling the part .   The first mounting member is an inner cylinder, and the second mounting member is an outer cylinder surrounding the inner cylinder, thereby forming a cylindrical bush as a whole, and the stopper from the outer cylinder side. 2. The vibration isolator according to claim 1, wherein the vibration isolator protrudes toward the inner cylinder.   The anti-vibration rubber includes a pair of side walls facing the axial direction of the inner cylinder, the stopper is disposed between the pair of side walls, and the side surface includes a surface facing the pair of side walls. The vibration isolator according to claim 2, wherein the groove is formed on a side surface of the vibration isolator.   The anti-vibration rubber includes an arm part that connects the inner cylinder and the outer cylinder and surrounds a part of the liquid chamber, and the side surface includes a surface that faces the arm part, and a surface that faces the arm part. The vibration isolator according to claim 2, wherein the groove is formed.

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