JP2009108906A - Vibration damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration damper capable of effectively producing a two-stage stopper characteristic with respect to the input of a vibration load. <P>SOLUTION: A rubber bushing 11 includes an inner cylinder body 12, an outer cylinder body 13 to surround the inner cylinder body 12 axially outward, and a rubber elastic body 20 provided between the inner cylinder body 12 and the outer cylinder body 13 for connecting both the cylinder bodies to each other. A resin stopper 30 is projected toward an opening chamber 21 formed in the rubber elastic body 20 from the outer periphery of the inner cylinder body 12 so as to face a rubber swelled portion 22 provided in the inner peripheral surface of the outer cylinder body 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vibration isolator.

  Conventionally, as an anti-vibration device used for an engine mount, a suspension bush, etc. of an automobile, an apparatus in which an inner cylinder body and an outer cylinder body are coupled by a rubber elastic body interposed between both cylinder bodies is known (patent) Reference 1-5).

  For example, in Patent Document 1, the rubber elastic body protrudes inward from the inner peripheral surface of the outer cylinder to the hollow portions provided on both sides in the main load input direction, and the vibration displacement of the inner cylinder is detected. An anti-vibration device having a configuration in which a bulging portion that performs a stopper function is provided and a plurality of small cavities opened in the axial direction is provided in the bulging portion is described.

  6 and 7, the inner cylinder 12 protrudes inward from the inner peripheral surface of the outer cylinder 13 into the opening chambers 21 provided on both sides of the rubber elastic body 20 in the main load input direction. A torque rod A using a vibration isolator having a structure in which a rubber bulging portion 22 that functions as a stopper against vibration displacement of the rubber bulging portion 22 is provided and an opening 5 that opens in the axial direction is provided in the rubber bulging portion 22 is described. Has been.

In these vibration isolators, the dynamic spring constant in the main load input direction can be reduced because it is more easily elastically deformed up to a predetermined amplitude range than the rubber bulging portion 22 having no small cavity or opening 5. On the other hand, at the time of vibration with a large amplitude, the small cavity and the opening 5 are crushed and the wall surface is brought into close contact so that the spring force required as a stopper spring can be maintained, and a two-stage stopper characteristic is given to the input of the vibration load. I am doing so.
JP 2006-194330 A Japanese Patent Laid-Open No. 10-252811 JP 2006-349068 A JP 2007-077999 A Japanese Utility Model Publication No. 6-63953

  However, in the vibration isolator described in Patent Document 1, the dynamic spring constant is increased because the hole diameter of the small cavity provided in the bulging portion is small, and the vibration isolating characteristics against vibration with small amplitude are insufficient. There is a possibility that the stage stopper characteristics may not be sufficiently obtained. Further, in the vibration isolator shown in FIGS. 6 and 7, since the opening width in the circumferential direction of the opening 5 provided in the rubber bulging portion 22 is large, the amount of displacement with respect to vibration with a large amplitude increases, and the vibration isolating device The durability of the device may be reduced.

  The present invention has been made in view of such points, and an object of the present invention is to provide a vibration isolator capable of effectively exhibiting two-stage stopper characteristics with respect to an input of a vibration load. It is in.

  In order to achieve the above object, in the present invention, an elastically deformable resin stopper portion is provided so as to protrude from the outer periphery of the inner cylinder so as to face the rubber bulge portion.

  Specifically, the present invention relates to an inner cylindrical body, an outer cylindrical body that surrounds the radially outer side of the inner cylindrical body, and a rubber elastic body that is provided between the inner cylindrical body and the outer cylindrical body and connects the two. The following solutions were taken for the vibration isolator equipped with

That is, the invention of claim 1 is formed with opening chambers that open in the cylinder axis direction of the outer cylinder on both sides of the rubber elastic body in the main load input direction.
A rubber bulging portion that bulges into the opening chamber is provided on the inner peripheral surface of the outer cylindrical body,
The inner cylinder is provided with an elastically deformable resin stopper that protrudes from the outer periphery toward the opening chamber and faces the rubber bulge.

  According to the first aspect of the present invention, the resin stopper is provided so as to protrude from the outer periphery of the inner cylindrical body toward the opening chamber so as to face the rubber bulging portion. When the inner cylinder vibrates, the stopper comes into contact with the rubber bulge and the stopper is elastically deformed in the elastic region. Two-stage stopper characteristics can be obtained.

  That is, for vibrations with small amplitude, such as engine idle vibration, the dynamic spring constant in the main load input direction is reduced by suppressing the vibration only by elastic deformation of the stopper portion, and the first stage of the stopper characteristics. A long linear region is ensured. On the other hand, for vibrations with large amplitude, such as during sudden acceleration of an automobile, the rubber bulge is elastically deformed following elastic deformation within the elastic region of the stopper, thereby increasing the dynamic spring constant and the stopper spring. The necessary spring force can be maintained. Thereby, the stopper characteristic of two steps can be effectively exhibited with respect to the input of the vibration load.

The invention of claim 2 is the invention according to claim 1,
The stopper portion includes a main body portion fitted to the outer peripheral surface of the inner cylindrical body, a pair of protrusion portions protruding from both ends in the width direction of the main body portion toward the opening chamber, and tips of the pair of protrusion portions. A pair of abutting portions that extend inward in the width direction of the main body portion, face the rubber bulging portion, and have their tips abutted against each other.

  According to the second aspect of the present invention, when the inner cylinder vibrates in the main load input direction, the pair of contact portions extending inward in the width direction of the main body portion contact the rubber bulge portion. The abutment part is elastically deformed so that it bends toward the main body with the tip of the protrusion as a fulcrum, and the rubber bulge part is elastically deformed. Can be demonstrated.

The invention of claim 3 is the invention of claim 2,
The partition chamber partitioned by the main body portion, the projecting portion, and the contact portion in the stopper portion is provided with a rubber bulging portion that bulges from the surface of the main body portion into the partition chamber. It is a feature.

  According to the invention of claim 3, when the inner cylinder vibrates in the main load input direction, the pair of abutting portions abut against the rubber bulge portion and bend toward the main body portion with the tip of the protruding portion as a fulcrum. If elastically deformed, the tip of the abutting portion abuts on the rubber bulging portion in the compartment and no longer bends. Therefore, an excessive pressing force is applied to the contact portion of the stopper portion to exceed the elastic region, which is advantageous in preventing the stopper portion from being damaged.

The invention of claim 4 is the invention according to claim 1,
The tip of the stopper portion is characterized in that a cross section viewed from the cylinder axis direction of the inner cylinder is formed in a substantially Y shape.

  According to the fourth aspect of the present invention, when the inner cylinder vibrates in the main load input direction, the distal end portion of the stopper portion formed in a substantially Y shape is placed on the inner peripheral surface of the outer cylinder body. The rubber bulges come into contact with the base end portions of the branches that are substantially Y-shaped, and the stoppers are elastically deformed in the elastic region. Subsequently, the rubber bulges are elastically deformed. On the other hand, it is possible to effectively exhibit a two-stage stopper characteristic.

Invention of Claim 5 in any one of Claims 1 thru | or 4,
A portion of the stopper portion that is in contact with the inner peripheral surface of the outer cylindrical body or the rubber bulging portion is covered with a rubber layer.

  According to the fifth aspect of the present invention, since the portion of the stopper portion that contacts the inner peripheral surface of the outer cylindrical body or the rubber bulging portion is covered with the rubber layer, the stopper portion is the inner peripheral surface of the outer cylindrical body or Since this rubber layer functions as a buffer rubber when it comes into contact with the rubber bulging portion, vibration can be attenuated more efficiently.

  As described above, according to the present invention, the vibration spring constant in the main load input direction is reduced by suppressing the vibration only by elastic deformation of the stopper portion with respect to the vibration having a small amplitude such as an idle vibration of the engine. While the linear region of the first stage of the stopper characteristic is secured long, the rubber bulging portion is followed by elastic deformation within the elastic region of the stopper portion for vibrations with a large amplitude, such as during sudden acceleration of an automobile. By elastically deforming, the dynamic spring constant is increased so that the necessary spring force can be maintained as a stopper spring, so that two-stage stopper characteristics can be effectively exhibited with respect to the input of a vibration load.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature and is not intended to limit the present invention, its application, or its use.

<Embodiment 1>
FIG. 1 is a cross-sectional view showing a configuration of a rubber bush 11 as a vibration isolator according to Embodiment 1 of the present invention. The rubber bush 11 is used, for example, in a connecting portion on the power plant side of the torque rod A as shown in FIG. The torque rod A is not shown, but the lower end of the engine and transmission (power plant) mounted horizontally in the engine room of the automobile is connected to a vehicle body side member such as a rear subframe so that the power plant is excessively large. This is for restricting the rocking.

  The torque rod A shown in FIG. 2 is fitted into an aluminum alloy bracket 10 in which small insertion holes 10a and large insertion holes 10b are provided in parallel at both ends in the longitudinal direction, and the respective insertion holes 10a and 10b. It consists of rubber bushes 1 and 11. The rubber bush 1 is fitted into the small fitting hole 10a, and the inner cylinder 2 is connected to the lower part of the power plant by a bolt or the like (not shown). Similarly, the inner cylinder 12 of the rubber bush 11 fitted into the large insertion hole 10b is connected to a member on the vehicle body side. A through hole 10c for weight reduction is formed in an intermediate portion (main shaft portion of the torque rod A) of the bracket 10 sandwiched between the two insertion holes 10a and 10b.

  The torque rod A that connects the lower part of the power plant to the rear vehicle body side member has a longitudinal direction (axial direction of the main shaft portion) when the power plant tilts backward due to the reaction force during a rapid acceleration of the automobile. A large tensile load acts, and this is input to the rubber bush 11 as a main load in the radial direction. Therefore, since the rubber bush 11 is required to quickly attenuate the backlash caused by receiving such a large main load, it is necessary to increase the dynamic spring constant. However, if the dynamic spring constant is too high, there is a possibility that the anti-vibration characteristic cannot be exhibited sufficiently for vibrations with small amplitudes such as engine idle vibrations.

  Therefore, in the present invention, the rubber bush 11 on the vehicle body side is configured to be able to effectively exhibit a two-stage stopper characteristic with respect to the input of the vibration load. Specifically, the rubber bush 11 includes a metal inner cylinder 12, a metal outer cylinder 13 that surrounds the radially outer side of the inner cylinder 12, and a space between the inner cylinder 12 and the outer cylinder 13. Are provided with a rubber elastic body 20 that connects the two, and a resin stopper 30 provided on the outer periphery of the inner cylinder 12. More precisely, the inner cylinder 12 is connected to the outer cylinder 13 via the main body 31 of the stopper 30 and the rubber elastic body 20.

  Opening chambers 21 that open in the cylinder axial direction of the outer cylinder 13 are formed on both sides of the rubber elastic body 20 in the main load input direction, and both sides of the rubber elastic body 20 in the direction perpendicular to the main load input direction are main springs. Parts 23 and 23. A rubber bulging portion 22 that bulges into the opening chamber 21 is provided on the inner peripheral surface of the outer cylindrical body 13.

  The inner cylinder 12 is provided with an elastically deformable stopper portion 30 that protrudes from the outer periphery thereof into the opening chamber 21 and faces the rubber bulging portion 22. Specifically, the stopper portion 30 includes a substantially rectangular main body portion 31 fitted to the outer peripheral surface of the inner cylindrical body 12 and a pair of protrusions projecting into the opening chamber 21 from both widthwise ends of the main body portion 31. A pair of projecting portions 32, 32 and a pair of abutting portions that extend from the distal ends of the pair of projecting portions 32, 32 toward the inner side in the width direction of the main body 31 to face the rubber bulging portion 22 and whose distal ends are butted together. And contact portions 33, 33. The stopper portion 30 is formed with a compartment 25 defined by a main body portion 31, a projecting portion 32, and a contact portion 33.

  Further, the surfaces of the pair of protrusions 32 and 32 and the contact portions 33 and 33 are covered with a rubber layer 24 formed integrally with the rubber elastic body 20. When the contact portion 33 contacts the inner peripheral surface of the outer cylindrical body 13 or the rubber bulging portion 22, the rubber layer 24 functions as a buffer rubber, so that vibration can be attenuated more efficiently. . In addition, in the rubber bush 11 of this Embodiment 1, although it has set it as the structure which covered the surface of the protrusion part 32 and the contact part 33 with the rubber layer 24, it is not limited to this form, The resin part is exposed. The contact portion 33 may be in contact with the rubber bulging portion 22.

  When the power plant mounted horizontally on the car body of the automobile tilts backward due to a reaction force during acceleration and the like, and the tensile load acts in the longitudinal direction of the torque rod A attached to the lower part of the rubber bush 11, The load is input as a radial main load, and the inner cylinder 12 and the outer cylinder 13 are relatively displaced in the main load input direction. At this time, the main spring portion 23 of the rubber elastic body 20 is bent, the rubber elastic body 20 is relatively elastically deformed, and the contact portion 33 of the stopper portion 30 is in contact with the rubber bulging portion 22 so that the stopper portion Since 30 functions as a stopper for restricting the relative displacement between the inner cylinder 12 and the outer cylinder 13, excessive deformation of the main spring portion 23 of the rubber elastic body 20 can be prevented even when a large main load is input. Sex can be secured.

  Here, with respect to vibration with a small amplitude, such as engine idle vibration, after the abutment portion 33 of the stopper portion 30 abuts against the rubber bulging portion 22, the protruding portion that becomes the base end portion of the abutment portion 33 The contact portion 33 is elastically deformed so as to bend inward of the compartment 25 with the tip of 32 as a fulcrum. As described above, since the dynamic spring constant in the main load input direction is reduced by suppressing the vibration only by the elastic deformation of the contact portion 33, a long first linear region of the stopper characteristic is ensured. Can do.

  On the other hand, with respect to vibration with a large amplitude, such as during sudden acceleration of an automobile, the rubber bulging portion 22 is elastically deformed following the elastic deformation in the elastic region of the abutting portion 33 of the stopper portion 30. The spring constant is increased so that the spring force required as a stopper spring can be maintained. Thereby, the vibration resulting from the main load input is effectively damped by the two-stage stopper characteristics, and the swing of the power plant during acceleration / deceleration can be quickly damped.

  FIG. 3 is a graph showing the relationship between the load and the deflection of the rubber bush 11 according to Embodiment 1 of the present invention and the conventional rubber bush. In FIG. 3, the solid line 50 indicates the characteristics of the rubber bush 11 of the present invention, the broken line 51 indicates the characteristics of the rubber bush described in FIGS. 6 and 7, and the two-dot chain line 52 indicates the characteristics of the rubber bush described in Patent Document 1.

  As shown in FIG. 3, each rubber bush shows a two-stage stopper characteristic, but the rubber bush 11 according to the first embodiment has a longer first-stage linear region than the conventional rubber bush. You can see that it is secured. That is, the rubber bush 11 according to the first embodiment reduces the dynamic spring constant in the main load input direction for vibrations with a small amplitude, while increasing the dynamic spring constant for vibrations with a large amplitude. The necessary spring force can be maintained. Thereby, compared with the conventional rubber bush, a two-stage stopper characteristic can be effectively exhibited with respect to the input of the vibration load.

  As described above, according to the rubber bush 11 as the vibration isolator according to the first embodiment, the resin stopper portion 30 is opened from the outer periphery of the inner cylindrical body 12 so as to face the rubber bulging portion 22. 21 so that when the inner cylinder 12 vibrates in the main load input direction, the contact portion 33 of the stopper portion 30 contacts the rubber bulging portion 22 and the contact portion 33 is elastic. By elastically deforming in the region and subsequently elastically deforming the rubber bulging portion 22, a two-stage stopper characteristic can be obtained with respect to the input of the vibration load.

  That is, for a small amplitude vibration such as an engine idle vibration, the dynamic spring constant in the main load input direction is reduced by suppressing the vibration only by the elastic deformation of the contact portion 33 of the stopper portion 30, and the stopper A long linear region in the first stage of characteristics is secured. On the other hand, with respect to vibration with a large amplitude, such as during sudden acceleration of an automobile, the rubber bulging portion 22 is elastically deformed following the elastic deformation in the elastic region of the abutting portion 33 of the stopper portion 30. The spring constant is increased so that the spring force required as a stopper spring can be maintained. Thereby, the stopper characteristic of two steps can be effectively exhibited with respect to the input of the vibration load.

<Modification>
FIG. 4 is a view corresponding to FIG. 1 showing a modification of the rubber bush 11 of the first embodiment. As shown in FIG. 4, a rubber bulging portion 22 that bulges into the compartment 25 is formed on the surface of the main body portion 31 of the stopper portion 30. Other configurations are the same as those of the first embodiment.

  With such a configuration, when the inner cylindrical body 12 vibrates in the main load input direction, the contact portion 33 contacts the rubber bulging portion 22 and the tip of the protruding portion 32 serves as a fulcrum toward the main body portion 31 side. When elastically deforming so as to bend, the tip of the contact portion 33 contacts the rubber bulging portion 22 in the compartment 25 and does not bend any further. Therefore, an excessive pressing force is applied to the contact portion 33 of the stopper portion 30 to exceed the elastic region, which is advantageous in preventing the stopper portion 30 from being damaged.

<Embodiment 2>
FIG. 5 is a cross-sectional view showing a configuration of a rubber bush 41 as a vibration isolator according to Embodiment 2 of the present invention. Since the difference from the first embodiment is only the shape of the stopper portion 45, the same parts as those of the first embodiment are denoted by the same reference numerals and only the differences will be described below.

  As shown in FIG. 5, the inner cylinder 12 of the rubber bush 41 is provided with an elastically deformable stopper portion 45 that protrudes from the outer periphery thereof into the opening chamber 21 and faces the rubber bulging portion 22. Yes. Specifically, the stopper portion 45 includes a ring-shaped main body portion 46 fitted to the outer peripheral surface of the inner cylindrical body 12, and a base end portion 47 that protrudes and extends from the outer periphery of the main body portion 46 into the opening chamber 21. And a pair of abutting portions 48 and 48 branched from the distal end of the base end portion 47 so that the cross section of the stopper portion 45 viewed from the cylindrical axis direction of the inner cylindrical body 12 is substantially Y-shaped, A relative displacement between the inner cylindrical body 12 and the outer cylindrical body 13 is restricted by a predetermined value or more. A main body 46 of the stopper 45 is embedded in the rubber elastic body 20. Further, the contact surface 49 that faces the rubber bulging portion 22 at the branched portion of the base end portion 47 and the contact portions 48 and 48 is concave corresponding to the surface shape of the rubber bulging portion 22 facing this. Is formed.

  In the rubber bush 41 of the second embodiment, the surface of the contact portion 33 is not covered with the rubber layer, and the resin portion is exposed, and the resin portion is exposed to the rubber bulging portion 22 and the outer cylindrical body 13. However, the present invention is not limited to this configuration, and the surface of the contact portion 33 may be covered with a rubber layer so as to function as a buffer rubber.

  As described above, according to the rubber bush 41 as the vibration isolator according to the second embodiment, when the inner cylindrical body 12 vibrates in the main load input direction, the stopper portion 45 formed in a substantially Y shape. The rubber bulging portion 22 abuts on the inner peripheral surface of the outer cylindrical body 13 and the abutting surface 49 at a location where the stopper portion 45 branches in a substantially Y shape, so that the stopper portion 45 is in the elastic region. Therefore, the rubber bulging portion 22 is elastically deformed, so that a two-stage stopper characteristic can be effectively exhibited with respect to the input of the vibration load.

  As described above, the present invention can provide a highly practical effect that it is possible to provide an anti-vibration device that can effectively exhibit a two-stage stopper characteristic with respect to an input of a vibration load. Therefore, it is extremely useful and has high industrial applicability.

It is sectional drawing which shows the structure of the rubber bush as a vibration isolator which concerns on Embodiment 1 of this invention. It is a top view which shows the structure of the torque rod using the bush. It is a graph which shows the relationship between the load and bending of the rubber bush which concerns on this Embodiment 1, and the conventional rubber bush. It is the FIG. 1 equivalent view which shows the modification of the bush. It is sectional drawing which shows the structure of the rubber bush which concerns on this Embodiment 2. FIG. It is a perspective view which shows the structure of the torque rod using the conventional rubber bush. It is a top view which shows the structure of the torque rod using the conventional rubber bush.

Explanation of symbols

11 Rubber bush (anti-vibration device)
DESCRIPTION OF SYMBOLS 12 Inner cylinder 13 Outer cylinder 20 Rubber elastic body 21 Open chamber 22 Rubber bulging part 24 Rubber layer 25 Compartment room 30 Stopper part 31 Main-body part 32 Projection part 33 Contact part

Claims (5)

An anti-vibration device comprising an inner cylinder, an outer cylinder surrounding the radially outer side of the inner cylinder, and a rubber elastic body that is provided between the inner cylinder and the outer cylinder and connects the two There,
On both sides of the rubber elastic body in the main load input direction, an opening chamber is formed that opens in the cylinder axis direction of the outer cylinder body,
A rubber bulging portion that bulges into the opening chamber is provided on the inner peripheral surface of the outer cylindrical body,
The vibration isolating device is characterized in that the inner cylinder body is provided with an elastically deformable resin stopper portion that protrudes from the outer periphery toward the opening chamber and faces the rubber bulging portion. In claim 1,
The stopper portion includes a main body portion fitted to the outer peripheral surface of the inner cylindrical body, a pair of protrusion portions protruding from both ends in the width direction of the main body portion toward the opening chamber, and tips of the pair of protrusion portions. And a pair of abutting portions each extending toward the inside in the width direction of the main body, facing the rubber bulging portion, and having their tips abutted against each other. In claim 2,
The partition chamber partitioned by the main body portion, the projecting portion, and the contact portion in the stopper portion is provided with a rubber bulging portion that bulges from the surface of the main body portion into the partition chamber. Anti-vibration device characterized. In claim 1,
The tip of the stopper portion is formed in a substantially Y-shaped cross section as viewed from the cylinder axis direction of the inner cylinder. In any one of Claims 1 thru | or 4,
An anti-vibration device characterized in that an inner peripheral surface of the outer cylindrical body or a portion in contact with the rubber bulging portion in the stopper portion is covered with a rubber layer.

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