JP2012117626A - Vibration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration control device achieving reduction in weight by forming both of an outer cylinder and a bracket with a resin material, in which a bush is effectively prevented from unintended falling-off from the bracket during the use or the like of the device.SOLUTION: The vibration control device includes: a bush 4 in which an inner cylinder 1 and an outer cylinder 2 disposed in parallel with each other are connected to each other by an elastic member 3 disposed between the inner cylinder 1 and the outer cylinder 2; and a bracket 6 having a cylindrical part 5 holding the bush 4 inside, wherein both of the outer cylinder 2 of the bush 4 and the bracket 6 are formed of a resin material. An outward flange 2a is disposed at one end of the outer cylinder 2, and a flat face 5b in surface-contact with the outward flange 2a is disposed at one end of the cylindrical part 5 of the bracket 6, and the flat face 5b of the bracket 6 and the flange 2a are fixed to each other.

Description

  The present invention relates to a bush formed by connecting an inner cylinder and an outer cylinder arranged in parallel with each other by an elastic body arranged between them, and a bracket having a cylindrical portion that holds the bush inside. The present invention relates to an anti-vibration device suitable for use as an engine mount, and in particular, proposes a technology that can effectively prevent the bush from coming out of the bracket in a device that achieves further weight reduction. Is.

  Conventionally, in this type of vibration isolator, both the outer cylinder of the bush and the bracket having the cylindrical portion that holds the bush are made of a metal material. When the bush formed by connecting the inner cylinder and the outer cylinder with an elastic body is assembled to the inside of the metal, the outer diameter is the same as or slightly larger than the inner diameter of the metal bracket. The bushing outer cylinder is press-fitted inside the metal bracket, so that the outer peripheral surface of the metal bushing outer cylinder is firmly frictionally engaged with the inner peripheral surface of the metal bracket to hold the bushing on the bracket. I was letting.

  Here, for the purpose of reducing the weight of the device, when the outer cylinder of the bush is formed of a resin material having a specific gravity smaller than that of the metal material, the resin-made bush outer cylinder is frictionally engaged inside the metal bracket. May cause damage to a resin outer cylinder that is weaker than a metal one when it is press-fitted with a force large enough to exert the required holding force based on Therefore, the holding force of the bush by the bracket cannot be increased as expected, and therefore, the bush may come out in the axial direction of the bracket.

  On the other hand, Patent Document 1 discloses that "an outer cylinder that is press-fitted into an outer cylinder (made of a resin material), an inner cylinder that is disposed inside the outer cylinder, and these outer cylinder and inner cylinder. And a cylindrical elastic body that is elastically connected to each other, and a recess is formed on one end in the axial direction of the outer cylinder over its entire circumference. In the outer cylinder, the diameter of the other end portion located on the other end side in the axial direction from the concave portion is reduced in diameter in a state where the restriction from the outer side in the radial direction to the one end side portion located on the one end side in the axial direction from the concave portion is released When it is deformed, there has been proposed a vibration isolator characterized in that the one end side portion is configured to warp radially outward around the concave portion. According to this vibration isolator, In addition to generating frictional force between the other end of the outer cylinder and the press-fit surface of the outer cylinder Becomes one end portion of the outer cylinder also allows to engage the portion continuing from one axial end to the press-fitting surface at the outer tube, the vibration damping device can be firmly fixed in the outer tube and ".

JP 2009-270586 A

By the way, when this type of vibration isolator is used for an application to be mounted on a vehicle, this type of vibration isolator itself, which is sometimes used as an engine mount of a vehicle, is requested from the request of low fuel consumption of the vehicle. Under a situation where further weight reduction is desired, the vibration reduction device described in Patent Document 1 in which only the outer cylinder is made of resin cannot achieve the required weight reduction. .
Therefore, it has been proposed that not only the outer cylinder of the bush but also the bracket that surrounds and holds the bush is made of a resin material.

  However, if both the outer cylinder of the bush and the bracket that holds the bush inside are made of resin, the resin bracket will also have low strength, and the bracket of the bush outer cylinder at the time of manufacturing the device When press-fitting into the inside of the cylindrical part, both the outer cylinder made of resin material and the bracket must be further reduced in order to prevent damage to both the outer cylinder and the bracket. Since the holding force of the bush is further reduced, a vibration isolator having a hook portion at one end portion of the outer cylinder as described in Patent Document 1 can also be used to prevent the bush from the bracket. The escape could not be prevented sufficiently.

  An object of the present invention is to solve such problems of the prior art, and the object of the invention is to further reduce weight by configuring the outer cylinder and the bracket with resin materials. In the anti-vibration device that realizes the above, an anti-vibration device that can effectively prevent unintentional withdrawal of the bush from the bracket when the device is used is provided.

  The vibration isolator of the present invention includes a bush formed by connecting an inner cylinder and an outer cylinder arranged in parallel to each other by an elastic member disposed between the inner cylinder and the outer cylinder, and the bush inside. A bracket having a cylindrical portion that is held on the outer cylinder, and the outer cylinder of the bush and the bracket are both formed of a resin material, and an outer flange is provided at one end of the outer cylinder, and the bracket A flat surface that is in surface contact with the outward flange is provided at one end of the cylindrical portion, and the flat surface of the bracket and the outward flange are mutually connected by, for example, ultrasonic welding, friction welding, laser welding, or the like. It is made to adhere.

  Preferably, the flange portion having the flat surface is provided at the one end of the cylindrical portion of the bracket, and the outward flange of the outer tube is extended to the outer peripheral side from the outer surface of the main body portion of the cylindrical portion. The flat surface of the flange portion of the bracket and the outward flange are fixed to each other in a region on the outer peripheral side of the outer surface of the main body portion of the cylindrical portion.

  By the way, at the end portion of the outer cylinder opposite to the outward flange side, at least part of the circumferential direction of the outer cylinder, the other end portion or the other end surface of the cylindrical portion of the bracket in a protruding posture toward the outer peripheral side. It is preferable to provide a hooking hooking portion that hooks onto the hook.

  In addition, it is preferable that this hooking part is divided and formed by the groove | channel provided in the outer peripheral surface of the edge part of an outer cylinder on the opposite side to the said outward flange side over the perimeter.

  According to the vibration isolator of the present invention, the outward flange provided at one end of the bushing outer cylinder and the flat surface provided at one end of the cylindrical portion of the bracket and in surface contact with the outward flange are connected to each other. By fixing the bushing, the bushing can be pressed without increasing the pressure input to the extent that both the low-strength resin bracket and the resinous bushing outer tube are damaged when the bushing is pressed into the cylindrical part of the bracket. While the outer cylinder can be press-fitted into the bracket, the bush holding force is reduced due to a decrease in pressure input. By securing a sufficiently strong connection between these members, the weight of the device can be reduced by making both the bracket and the bushing outer tube made of resin. Unintended escape fear of from Tsu door can be sufficiently removed.

  Here, for the purpose of further reducing the weight of the vibration isolator, even if the cylindrical portion of the bracket is made thin, a flange portion having a flat surface is provided at one end of the cylindrical portion of the bracket, By extending the outward flange of the outer cylinder to the outer peripheral side with respect to the outer surface of the main body portion of the cylindrical portion, for example, when performing ultrasonic welding, the flange portion of the bracket, which is close to each other, and Each of the outward flanges of the outer cylinder is joined to each other in a state where the outer peripheral part of the outer surface of the main body part of the cylindrical part is sandwiched by an ultrasonic welding device or the like. The flange portion and the outward flange of the outer cylinder can be fixed at a desired position under high joining accuracy.

  By the way, at least a part of the end portion of the outer cylinder on the side opposite to the outward flange, for example, at a plurality of locations in the circumferential direction, the outer peripheral side is not deformed by the inner peripheral surface of the cylindrical portion. When the hook engaging part that engages with the other end or the other end surface of the cylindrical part of the bracket is provided in the projecting position to the bracket, the cylindrical part of the bracket is connected to the outward flange and the outer peripheral side of the outer cylinder. Since it is sandwiched between and fixed to the hooking and engaging portion that protrudes toward the flange, it is possible to prevent the bush from coming out of the bracket in combination with the fixation of the outward flange to the flat surface of the cylindrical portion. The effect can be further enhanced.

  In this case, when the hook engaging portion is partitioned and formed by a groove provided on the outer peripheral surface of the outer cylinder on the side opposite to the outward flange side, over the entire circumference, the bush is attached to the bracket. Prior to assembly on the inside, a groove is provided in advance on the outer peripheral side of the end portion of the bushing outer cylinder without forming a hooking protrusion as a hooking engagement part protruding on the outer peripheral side in the bushing outer cylinder. Thus, when the press-fitting of the bushing outer cylinder into the cylindrical portion of the bracket is completed, only the portion of the outer cylinder on the distal end side than the groove is released from the restraint by the outer cylindrical portion on the outer peripheral side. The groove wall of the groove provided in the outer cylinder is elastically deformed and is engaged with the other end portion or the other end surface of the cylindrical portion, so that it is very easy to form the engaging portion on the outer cylinder. As such, improve the productivity of such anti-vibration devices It is possible.

It is a perspective view showing one embodiment of this invention. It is a longitudinal cross-sectional view containing the center axis line of the cylindrical part of a bracket of the apparatus shown in FIG. It is an expanded sectional view which shows the principal part of FIG. It is a longitudinal cross-sectional view which shows the modification of the cylindrical part of a bracket. It is an expanded sectional view which shows the other principal part of FIG. FIG. 6 is an enlarged sectional view showing the bush outer cylinder of FIG. 5 in a state before being press-fitted into the bracket. It is sectional drawing similar to FIG. 6 which shows the modification of the edge part of a bush outer cylinder. It is a longitudinal cross-sectional view which shows the assembly | attachment process of the vibration isolator of FIG. 2 only by the upper half part of a cylindrical part.

Embodiments of the present invention will be described below with reference to the drawings.
The anti-vibration device shown in FIG. 1 is formed by connecting an inner cylinder 1 and an outer cylinder 2 arranged in parallel to each other by an elastic member 3 arranged between them and made of a rubber material or the like. It comprises a bush 4 and a bracket 6 having a cylindrical portion 5 that holds the bush 4 inside.
Here, the engine mount to which the present invention is applied will be described as an example, but the present invention is naturally applicable to a bush type vibration isolator other than the engine mount.

Here, while the inner cylinder 1 is formed of, for example, a metal material or other rigid material, the outer cylinder 2 and the bracket 6 are both formed of a resin material such as polyamide, polypropylene, polybutene, or the like.
Thus, since the outer cylinder 2 and the bracket 6 are formed of a resin material having a specific gravity smaller than that of a metal material, the vibration isolator can be significantly reduced in weight. When used as an engine mount, it can contribute to the improvement of the fuel efficiency of the vehicle.

  By the way, in this vibration isolator in which the outer cylinder 2 and the bracket 6 are both made of resin, when the bush 4 is assembled to the bracket 6, the bush outer cylinder 2 is press-fitted into the cylindrical portion 5 of the bracket 6 under a large press-fit tightening allowance, the low-strength resin bracket 6 and the resin outer cylinder 2 may be damaged, Is small, the holding force of the bushing outer cylinder 2 will be insufficient. For example, the press-fitting length L in the axial direction of the outer cylinder 2 in the cylindrical portion 5 shown in FIG. The bush holding force is such that the resin bracket 6 and the resin outer cylinder 2 cannot be damaged by appropriately selecting the difference in diameter between the inner diameter of the cylindrical portion 5 and the outer diameter of the outer cylinder 2. Under the action, the outer peripheral surface of the bushing outer cylinder 2 is Friction engaged with the inner peripheral surface of Jo portion 5.

  By the way, in the present invention, in order to compensate for the low holding force of the bush 2 by the bracket 6, an outward flange 2a is provided over the entire circumference at one end located on the right side in FIG. As shown in the enlarged view of FIG. 3, a flat surface 5b that is in surface contact with the outward flange 2a is provided on the flange portion 5a at one end located on the right side of the shaped portion 5 as well. The outward flange 2a and the flat surface 5b are fixed to each other by, for example, ultrasonic welding, friction welding, laser welding, or the like.

According to this, the low bush holding force by the cylindrical portion 5 of the bracket 6 due to the fact that both the bracket 6 and the outer cylinder 2 are made of resin, the flat surface 5b of the cylindrical portion 5 and Since the bushing outer cylinder 2 can be effectively compensated by the fixing to the outward flange 2a, the bushing 4 can be prevented from unintentionally coming out of the bracket 6.
Here, in order to sufficiently enhance the mutual fixing force between the outward flange 2a and the flat surface 5b, both the bracket 6 and the outer cylinder 2 are made of the same kind of resin material selected from, for example, polyamide, polypropylene, polybutene and the like. It is preferable to form by.

  Here, as shown in FIGS. 4A and 4B, the flat surface of the cylindrical portion that makes the surface contact with the outward flange 2a of the outer cylinder 2 is the same as that of the cylindrical portions 15 and 25 that do not have the flange portion. Although it is possible to form the peripheral edge of the opening on one end side, it is possible to reduce the volume of the bracket to reduce the weight of the device, and the flat surface of the cylindrical portion and the outward flange of the outer cylinder From the viewpoint of ensuring the fixation, as shown in FIGS. 1 to 3, a flange portion 5 a formed with a flat surface 5 b is provided at one end of the cylindrical portion 5, and the outside of the outer cylinder 2 is further provided. The direction flange 2a extends to the outer peripheral side from the outer surface of the main body portion 5c of the cylindrical portion 5, and the flat surface 5b of the flange portion 5a of the cylindrical portion 5 and the outward flange 2a are It is preferable to fix in the region on the outer peripheral side of the outer surface of the main body portion 5c of the shaped portion 5 .

  That is, when the flat surface 5b of the cylindrical part 5 and the outward flange 2a of the outer cylinder 2 are fixed by, for example, ultrasonic welding, the flange part 5a having the flat surface 5b is provided on the cylindrical part 5. By providing, by the ultrasonic welding apparatus 100 as shown by a broken line in FIG. 3, the flange portion 5a and the outward flange 2a that are close to each other are sandwiched from the respective back surfaces of the mutually facing surfaces. It becomes possible to support the surface sufficiently sufficiently, and the fixed portion between the flat surface 5b and the outward flange 2a is a region on the outer peripheral side of the outer surface of the body portion 5c of the cylindrical portion 5 of the flat surface 5b. By applying the exciting force in the axial direction indicated by the arrow in the figure, which results in fusion bonding of the flat surface 5b with the outward flange 2a based on the operation of the welding apparatus 100, the welding apparatus 100 Since the displacement in the axial direction of the mutual adhering portions of the cylindrical portion 5 and the outer cylinder 2 can be firmly restrained, even when the vibration isolator is further reduced in weight by reducing the thickness of the cylindrical portion 5. The joining accuracy between the tubular portion 5 and the bushing outer tube 2 can be increased.

  As shown in FIG. 1, the elastic member 3 that connects the inner cylinder 1 and the outer cylinder 2 of the bush 4 is provided with necessary voids 3a and 3b penetrating in the axial direction of the inner and outer cylinders. In the vibration isolator capable of exhibiting different vibration suppression characteristics with respect to the input vibrations in the right and left directions in the front view and the front view, the flat surface 5b of the cylindrical portion 5 and the outward flange 2a are fixed to the bush. It is preferable to perform ultrasonic welding rather than the friction welding which melt-joins 4 based on the rotational displacement of the surroundings of 4 axis | shafts.

  Also, as shown in FIGS. 1 to 3 and 4 (a), the cylindrical portions 5 and 15 are cylindrical on the outer peripheral side of the flat surfaces 5b and 15b where the outward flange 2a of the outer cylinder 2 comes into surface contact. Since it is not an essential configuration of the present invention, the annular portions 5d and 15d that continuously extend from the portions 5 and 15 and extend in the axial direction and surround the outer peripheral side of the outward flange 2a are shown in FIG. In this way, the outward flange 2a can be brought into surface contact with the flat surface 25b in a posture exposed from the cylindrical portion 25.

By the way, at the end of the outer cylinder 2 opposite to the outward flange 2a, located on the left side in the drawing, as shown in an enlarged view in FIG. In the state where the press-fitting into 5 is completed, it is possible to provide a hook engaging portion 2b that is released from the reduced diameter posture and elastically returns to the outer peripheral side and engages with the other end portion or the other end surface of the cylindrical portion 5.
As a result, the cylindrical portion 5 is sandwiched between the outward flange 2a and the hooking portion 2b of the outer cylinder 2, and in any direction of the outer cylinder 2 in the axial direction of the cylindrical portion 5. Of the bush 4 is sufficiently compensated for the low bush holding force by the cylindrical portion 5 due to the fact that both the bracket 6 and the bush outer cylinder 2 are made of resin. The risk of slipping out can be more reliably removed.

The hook engaging portion 2b is formed by a groove 2c extending over the entire circumference of the outer peripheral surface of the end portion of the outer cylinder 2, as shown in FIG. 6 in a state before the bush 4 is press-fitted into the bracket. In accordance with this, when the press-fitting of the bushing outer cylinder 2 into the cylindrical part 5 having an inner diameter slightly smaller than the outer diameter of the outer cylinder 2 is completed, the cylindrical part is On the other end side of 5, only the portion of the end portion of the outer cylinder 2 that is released from the diameter-reducing deformation by the cylindrical portion 5 and on the tip side of the groove 2 c is enlarged and deformed based on its own elastic restoring force. By doing so, as shown in FIG. 5, the bush outer cylinder 2 is prevented from coming off when the groove wall on the front end side is caught on the other end or the other end face of the cylindrical portion 5.
In this case, the central part of the bushing outer cylinder 2 in the axial direction from the groove 2c is frictionally engaged with the inner peripheral surface of the cylindrical part 5 while being deformed by the cylindrical part 5 in a reduced diameter. Will be.

On the other hand, the hook engaging portion 2b is press-fitted into the bracket over the entire circumference of the end portion of the outer cylinder 32 or at a plurality of locations in the end portion as shown in FIG. Even in the previous state, it can be formed by providing in advance a protrusion 32c protruding from the outer peripheral surface of the central portion of the bushing outer cylinder 32 in the axial direction.
The protrusion 32c provided on the end portion of the outer cylinder 32 is not limited to the shape shown in the figure as long as it is caught on the other end or the other end surface of the cylindrical portion 5, and is formed in various shapes. be able to.

  In assembling the bush 4 to the bracket 6 in the vibration isolator as described above, for example, as shown in FIG. 8 (a), only the upper half of the cylindrical portion 5 is shown in a sectional view. The bush 4 in which the inner cylinder 1 and the outer cylinder 2 are connected to each other by the elastic member 3 is connected to the bracket 6 in the direction indicated by the arrow in the drawing from the end portion of the outer cylinder 2 opposite to the outward flange 2a side. After press-fitting into the cylindrical part 5 in a required reduced diameter state, the outward flange 2a of the outer cylinder 2 comes into contact with, for example, a self-melting protrusion 5e provided on the flat surface 5b of the cylindrical part 5 The bushing outer cylinder 2 is further press-fitted into the cylindrical portion 5 while an axial excitation force is applied by an ultrasonic welding apparatus (not shown) to melt the protrusion 5e with the outward flange 2a. Finally, as shown in FIG. 8B, the outward flange 2a is flattened. By surface contact with the surface 5b, the cross of these members can be carried out by fixed under melting of protrusions 5e.

  Here, the protrusion 5e that is provided on the flat surface 5b of the cylindrical portion 5 and contributes to joining with the outward flange 2a when performing ultrasonic welding is provided at one or a plurality of locations in the circumferential direction of the flat surface 5b. In addition to being able to be formed, although not shown in the figure, the protruding portion can be provided on the outward flange 2 a of the outer cylinder 2.

  Here, in the case where the hook engaging portion 2b described above is provided at the end portion of the outer cylinder 2 opposite to the outward flange 2a, as shown in FIGS. 8 (a) and 8 (b), the bush 4 Both of the press-fitting step into the bracket and the mutual welding step of the flat surface 5b of the cylindrical portion 5 and the outward flange 2a of the outer tube 2 performed at the end of the press-fitting step, At the same time that the flat surface 5b and the outward flange 2a are in surface contact, the hook portion 2b is engaged with the other end portion or the other end surface of the tubular portion 5, and each of the tubular portion 5 and the outer tube 2 is engaged. In this type of vibration isolator, selecting the length in the axial direction is such that a sufficiently large bush holding force by the cylindrical portion 5 cannot be expected because both the bracket 6 and the bush outer cylinder 2 are formed of a resin material. Unintentional removal of bush outer cylinder 2 Thereby preventing the out of use condition of the device, rattling of the bush 4 in the cylindrical portion within 5, therefore, from the viewpoint of effectively preventing the generation of noise due to the rattling.

DESCRIPTION OF SYMBOLS 1 Inner cylinder 2 Outer cylinder 2a Outward flange 2b Engagement part 2c Groove 32c Projection part 3 Elastic member 3a, 3b Space 4 Bush 5, 15, 25 Cylindrical part 5a Flange part 5b, 15b, 25b Flat surface 5d, 15d annular portion 5e protrusion 6 bracket 100 ultrasonic welding device

Claims (4)

A bush formed by connecting an inner cylinder and an outer cylinder arranged in parallel with each other by an elastic member disposed between the inner cylinder and the outer cylinder, and a cylindrical portion that holds the bush inside. A vibration isolator comprising a bracket, wherein the outer cylinder of the bush and the bracket are both formed of a resin material,
An outward flange is provided at one end of the outer cylinder, and a flat surface that is in surface contact with the outward flange is provided at one end of the cylindrical portion of the bracket, and the flat surface of the bracket and the outward flange are connected to each other. Anti-vibration device that is fixed.   A flange portion having the flat surface is provided at the one end of the cylindrical portion of the bracket, and an outward flange of the outer tube is extended to the outer peripheral side from the outer surface of the main body portion of the cylindrical portion. The vibration isolator according to claim 1, wherein the flat surface of the flange portion and the outward flange are fixed to each other in a region on the outer peripheral side of the outer surface of the main body portion of the cylindrical portion.   A hook engaging with the other end portion or the other end surface of the cylindrical portion of the bracket in a protruding posture toward the outer peripheral side at least in the circumferential direction of the end portion of the outer tube opposite to the outward flange side. The vibration isolator according to claim 1 or 2, further comprising a portion.   The anti-vibration device according to claim 3, wherein the hooking portion is defined by a groove provided on an outer peripheral surface of an end portion of the outer cylinder opposite to the outward flange side over the entire circumference.