JPH07280013A - Vibration isolating bushing - Google Patents

Abstract

PURPOSE:To prevent the biting phenomenon at a flange part when an elastic body is press fit and assembled to an outer cylindrical body while the original vibration isolating property based on the deformation of a trimmed window part is secured, and prevent the generation of the abnormal noise during the use. CONSTITUTION:An inner cylindrical body 1 is connected to an outer cylindrical body 2 with a rubber elastic body, and trimmed window parts 4, 5 passing through the rubber elastic body in the X-axial direction of the respective cylindrical bodies are provided in the rubber elastic body at the position on each side where the inner cylindrical body is held from the vibration input direction. Thin-walled corrugated connecting walls 6a, 7a connecting the center position in the circumferential direction of opposite surfaces 34, 35, 36, 37 which are opposite in the orthogonal direction to the cylindrical axis of each trimmed window part are integrated with the rubber elastic body so as to be extended in the whole area in the cylindrically axial direction. A flange part engaged with an end surface of the outer cylindrical body is integrated with the rubber elastic body through expansion in the outer circumferential direction at each end in the cylindrically axial direction. Weakest parts 61a, 71a to be broken by the vibration input are formed on the bent part of each connecting wall, and a root part is formed to shift in a smooth curved surface to the opposite surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in, for example, a suspension bush of an automobile, and has a rubber elastic body having a cavity formed at a position in a vibration input direction for exhibiting a predetermined vibration damping characteristic. Regarding

[0002]

2. Description of the Related Art Conventionally, as this type of anti-vibration bush, as shown in FIGS. 9 and 10, a rubber elastic body having an inner cylinder a and an outer cylinder b interposed between a and b is used. The inner cylinder a is connected by c, and the inner cylinder a is in the vibration input direction (vertical direction in FIG. 9).
It is known that a rubber elastic body c sandwiched from both sides is formed with empty windows d and d penetrating in the cylinder axis X direction of the inner cylindrical body a as a space (for example, Japanese Utility Model Laid-Open No. 1-9696). See the bulletin). That is, by changing the size and the forming range of each of the draft windows d, the vibration damping characteristics are changed and adjusted according to the part to which the vibration damping bush is applied. Further, in such a vibration-proof bush, generally, for the purpose of relative positioning of the rubber elastic body c and the outer cylindrical body b in the cylinder axis X direction, protection of the end surface of the outer cylindrical body b, etc. The peripheral edges of both ends in the cylinder axis X direction are enlarged to form flange portions e that engage with the end surface of the outer cylinder body b. Then, in such a vibration-proof bush, first, the rubber elastic body c is formed by using the inner cylindrical body a as an insert material.
Is vulcanized and molded integrally with the inner cylinder a, and then the rubber elastic body c of the integrally molded product f (see FIG. 11) is press-fitted into the outer cylinder b to be assembled.

[0003]

However, in the above-mentioned conventional vibration-proof bushing, since each of the window parts d is formed in a predetermined circumferential range centered on the cylinder axis X of the rubber elastic body c, The outer peripheral portion of the rubber elastic body c in the circumferential range g, g in which the both opening windows d of the integrally molded product f are formed,
The thickness is thinner than that of the outer peripheral portion of the rubber elastic body c in the circumferential range h of the solid portion where the both window portions d, d are not formed, and the waist becomes weak. Therefore, when the integrally molded product f is press-fitted into the outer cylindrical body b at the time of manufacturing, the progress of the outer peripheral part of the circumferential ranges g, g in which the both vent windows d, d are formed. As shown in FIG. 11, the flange portion e of the solid portion in the circumferential range h, h is relatively delayed as compared with the outer circumferential portion of the solid portion in the circumferential range h, h. Even if it comes out to the front end side in the press-fitting direction and engages with its end face, the flange portion e in the circumferential range g, g corresponding to the above-mentioned both opening windows d, d
However, there is a case where a biting phenomenon occurs that is still left inside the outer cylindrical body b.

When this biting phenomenon occurs, in order to eliminate this biting, the integrally molded product f is once press-fitted more than necessary so that the flange portion e of the entire circumferential range g, h is fitted to the outer cylindrical body b. It is necessary to alternately perform the work of pushing out from the front end side in the press-fitting direction and then pushing it in the opposite direction to expose the flange portion e on the rear end side in the press-fitting direction to the outside of the outer cylindrical body b. For this reason, the work of assembling the anti-vibration bush is time-consuming, resulting in an increase in the takt time and an increase in the manufacturing cost.

In use, the rubber elastic body c is largely deformed as a large load such as an impact force is applied to the one of the inner cylinder a and the outer cylinder b in the vibration input direction. There is a case where a relatively moves in the vibration input direction and one stopper portion i of the rubber elastic body c presses against the facing surface j of the draft window portion d. In this case, an abnormal noise is generated when leaving in the opposite direction after the pressure contact, and similarly, an abnormal noise is generated when the other stopper part i is pressed against and separated from the facing surface j of the other window part d. .

On the other hand, in order to deal with such a problem, it is also necessary to secure the original anti-vibration characteristic based on the deformation of the window parts d, d.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an elastic body for connecting an inner cylinder and an outer cylinder with each other in an axial direction of the inner cylinder. In a vibration-isolating bush in which a space extending to the outer cylinder and a flange portion that engages with the end surface of the outer cylindrical body are formed, while ensuring the original vibration-damping characteristics, the elastic body is press-fitted into the outer cylindrical body during assembly. The purpose is to prevent the flange from being caught, and at the same time to prevent the generation of abnormal noise during use.

[0008]

In order to achieve the above object, the invention according to claim 1 provides an inner cylinder, an outer cylinder arranged to surround the inner cylinder, and an outer cylinder. An elastic body is provided between the inner cylinder and the inner cylinder to connect the inner peripheral surface of the outer cylinder and the outer peripheral surface of the inner cylinder to each other. And one or more cavities extending in the cylinder axis direction are formed at the end faces in the direction of the cylinder, and the flanges at the both ends in the cylinder axis direction are expanded in diameter to cover both end faces of the outer cylinder. It is assumed that the elastic body is connected to the outer cylindrical body by being pressed into the outer cylindrical body in the cylinder axis direction of the inner cylindrical body. In this structure, at least one of linear portions extending in the cylinder axis direction of both facing surfaces of the cavity facing each other in the direction orthogonal to the cylinder axis of the inner cylinder is connected to the cavity.
The two thin connecting walls are integrally formed with the elastic body.

According to a second aspect of the present invention, in the first aspect of the invention, the connecting wall is formed at least in the region of the elastic body on the front end side in the press-fitting direction of the elastic body.

According to a third aspect of the present invention, in the first aspect of the invention, the connecting wall is formed continuously over substantially the entire region of the cavity in the cylinder axis direction.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the connecting wall has a cross-sectional shape that expands in the left-right direction with respect to the direction orthogonal to the cylinder axis of the inner cylinder. It is configured to be formed.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the connecting wall has a cross-section in a skewed shape extending obliquely with respect to a direction orthogonal to the cylinder axis of the inner cylinder. It is configured to be formed.

According to a sixth aspect of the present invention, in the first aspect of the invention, the connecting wall at an intermediate position between both facing surfaces of the void has a weakest portion having a thinner wall thickness than other portions. The structure is formed so as to extend in the cylinder axis direction.

The invention according to claim 7 is the same as claim 1.
In the invention described above, the root portion of the connecting wall in the vicinity of both facing surfaces is formed so as to be continuous with a curved surface that smoothly bends with respect to the both facing surfaces.

[0015]

With the above construction, in the invention according to claim 1,
Since both facing surfaces of the void are connected to each other by the connecting wall, the inner peripheral portion and the outer peripheral portion of the elastic body in the void forming region divided by the existence of the void are connected by the connecting wall. become. As a result, when the elastic body is assembled by press-fitting into the outer cylinder body, the outer peripheral portion of the elastic body in the space forming region receives a resistance force in a direction opposite to the press-fitting direction due to friction with the inner peripheral surface of the outer cylinder body. Also, the outer peripheral portion of the elastic body is pulled toward the inner peripheral side of the elastic body through the connecting wall to be almost at the same time as the outer peripheral portion of the elastic body in the range other than the portion where the void is formed,
It proceeds at almost the same relative press-fitting speed. Therefore, it is possible to suppress or prevent the occurrence of a progress delay at the time of press-fitting the outer peripheral portion of the elastic body in the void formation region with respect to the region without a void, and the phenomenon of biting of the flange portion of the elastic body due to this progress delay. It is possible to prevent the occurrence of.

In addition, since the connecting wall connects the linear portions extending in the cylinder axis direction of the two opposing surfaces of the cavity with each other, and the connecting wall is formed thin, it is in use. In, even if vibration is input between the inner cylinder and the outer cylinder in the direction connecting the voids, the expansion or breakage of the connecting wall ensures the vibration-damping characteristics based on the deformation of the voids. Is achieved within a range that does not change much from the original anti-vibration characteristics. In addition, even if a large load such as impact force is applied to press the opposing surfaces of the void into contact with each other, the press contact is made with the thin connecting wall interposed therebetween. It is possible to avoid the generation of abnormal noise during the pressure contact-separation between the surfaces which are independent of each other and which are independent of each other.

According to the second aspect of the present invention, in addition to the function of the first aspect of the present invention, since the connecting wall is formed at least in the region of the elastic body on the front end side in the press-fitting direction of the elastic body, It is possible to effectively prevent the occurrence of the biting phenomenon of the flange portion on the front end side in the press-fitting direction at the time of assembly by press-fitting with the outer cylindrical body.

According to the third aspect of the present invention, in addition to the effect of the first aspect of the present invention, the connecting wall is formed continuously over substantially the entire area of the inner cylinder in the cylinder axis direction.
According to the invention described in claim 1, it is possible to surely prevent the biting phenomenon at the time of assembling and the generation of the abnormal noise at the time of use.

According to the invention described in claim 4, in addition to the operation according to the invention described in claim 1, the connecting wall has a corrugated shape which expands in the left-right direction with respect to the direction orthogonal to the cylinder axis of the inner cylinder. Therefore, when the space is deformed due to the input of vibration during use, the connecting wall expands and contracts as the opposing surfaces of the space move closer to each other. For this reason,
The deformation of the void is performed without being affected by the connecting wall, and the original vibration damping property based on the deformation of the void is exhibited.

According to the fifth aspect of the present invention, in addition to the effect of the first aspect of the invention, the cross section of the connecting wall has an oblique shape extending obliquely with respect to the direction orthogonal to the cylinder axis of the inner cylinder. Since it is formed so as to be the same as in the case of the invention described in claim 4, the deformation of the void accompanying the vibration input is performed without being affected by the connecting wall, and the original deformation based on the deformation of the void is performed. Anti-vibration property is exhibited.

Further, in the invention described in claim 6, in addition to the operation according to the invention described in claim 1, the wall thickness of the connecting wall at the intermediate position between the opposing surfaces of the cavity is made thinner than other portions. Since the weakest portion is formed so as to extend in the cylinder axis direction, it is likely to be broken by receiving an external force in the pulling direction. Therefore, when the elastic body is deformed due to the vibration input, even if the connecting wall connects the opposing surfaces in a straight line at the shortest distance, the elastic body is deformed to receive a tensile force and thus the above-mentioned maximum. By breaking at the weak part, the subsequent deformation of the void is performed according to the input vibration without being affected by the connecting wall at all and is based on the deformation of the void regardless of the cross-sectional shape of the connecting wall. The original anti-vibration property is exhibited.

Further, in the invention according to claim 7, in addition to the operation according to the invention according to claim 1, the root portion of the connecting wall in the vicinity of both facing surfaces of the void is smooth against the both facing surfaces. Since it is formed so that it is curved and continuous,
Even if a repeated tensile force acts on the root of the connecting wall due to the deformation of the void due to the input of vibration, the concentration of stress is prevented and the occurrence of cracks at the root is prevented. It is possible to prevent the crack from developing into the elastic body itself due to the crack in the root portion.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> FIGS. 1 and 2 show an anti-vibration bush according to a first embodiment of the present invention, in which 1 is an inner cylinder,
Reference numeral 2 denotes an outer cylinder body which is arranged on the outer peripheral side of the inner cylinder body 1 at a predetermined interval in a direction coaxial with the cylinder axis X of the inner cylinder body 3, and 3 denotes the outer cylinder body 2 and the inner cylinder body 1. It is inserted between 1 and 2
2 and 5 are rubber elastic bodies for joining and connecting the two with each other, 4 and 5 are a pair of open window portions as voids for adjusting the vibration damping characteristics of the rubber elastic body 3 to predetermined values, and 6 and 7 are the open window portions 4 , 5 are thin connecting walls.

The inner cylinder 1 is set to be longer than the outer cylinder 2 by a predetermined dimension, so that it can be attached to a vehicle body of an automobile, for example, by a bolt (not shown) that penetrates the inner cylinder 1 as a vibration receiving portion. Has become. Further, the outer cylinder body 2 can be attached via a bracket which holds the periphery of the outer cylinder body 2 or the outer cylinder body 2 itself as a vibration source, for example, to a suspension component member on the tire side of an automobile. ing.

The rubber elastic body 3 is formed by vulcanization integrally with the inner cylindrical body 1 so as to surround the inner cylindrical body 1 and have a substantially cylindrical shape coaxial with the cylindrical axis X. The rubber elastic body 3 has the opening window part 4 at one side position in one direction (vertical direction in FIG. 1) orthogonal to the cylinder axis X with the inner cylinder body 1 sandwiched therebetween, and the extraction window part at the other side position. Each part 5 is formed so as to penetrate in the cylinder axis X direction. The inner cylindrical body 1 and the outer cylindrical body 2 are interposed between the vibration source and the vibration receiving portion so that the vibration from the vibration source is input in the vertical direction (hereinafter referred to as the vibration input direction). It is supposed to be done. The both opening windows 4 and 5 are formed in a range and a size so that predetermined vibration damping characteristics can be obtained according to the vibration source of the portion to which the vibration damping bush is applied. In the embodiment, approximately 45 degrees to the left and right with respect to the circumferential direction about the cylinder axis X, centering on an axis including the cylinder axis X and extending in the vibration input direction (hereinafter referred to as a vibration input shaft; see Y in FIG. 1). Is formed into a substantially fan shape within the inner angle range. Then, the rubber elastic body 3 in a portion other than the formation range of the both window portions 4 and 5 (portions on both sides in the left-right direction sandwiching the inner cylindrical body 1 in FIG. 1) is the solid portion 3
0 and 30, and elastic support between both the inner cylindrical body 1 and the outer cylindrical body 2 is mainly performed by the both solid portions 30 and 30.

In the rubber elastic body 3, stopper portions 31, 32 (32 are shown only in FIG. 1) protruding in the vibration input direction from the inner cylindrical body 1 side with respect to the both extraction windows 4, 5. ) Is integrally formed with the rubber elastic body so that excessive deformation does not occur due to external force such as vibration input in the vibration input direction. In addition, the rubber elastic body 3
Flange portions 33, 33 are formed at both ends in the cylinder axis X direction. The outer peripheral edge of each of the flange portions 33 is expanded so as to have an outer diameter substantially the same as that of the outer cylindrical body 2,
The outer cylinder 2 is adapted to engage with and cover the edge of the outer cylinder 2 in the cylinder axis X direction.

The connecting wall 6 and the connecting wall 7 are integrally formed with the rubber elastic body 3 in the window 4 and the window 5, respectively. The connecting wall 6 is a pair of opposing surfaces facing each other in the vibration input direction of the draft window 4, that is,
The top surface 34 of the stopper portion 31 on the inner peripheral side and the inner surface 3 on the outer peripheral side
5 for connecting with each other, and these opposing surfaces 3
The linear portions extending over the entire area of the window 4 in the direction of the cylinder axis X are connected to each other at positions where the vibration input shafts 4, 35 intersect the vibration input shaft Y. Similarly, the connecting wall 7 has linear portions extending in the cylinder axis X direction at positions where the top surface 36 of the stopper portion 32 of the draft window portion 5 and the inner surface 37 on the outer peripheral side intersect the vibration input axis Y. Are connected. In other words, the connecting walls 6 and 7 are arranged so that the facing surfaces 3 of the draft windows 4 and 5 are provided over the entire area of the draft windows 4 and 5 in the cylinder axis X direction.
The substantially central positions of 4, 35, 36 and 37 in the circumferential direction are connected to each other.

Then, both facing surfaces 36 of the window part 5,
As shown in FIG. 3, a weakest portion 71, which is locally thinner than the other portions, is formed on the connecting wall 7 at an intermediate position between 37, and the facing surfaces 34, 34 of the draft window portion 4, The weakest portion 61 is similarly formed on the connecting wall 6 at an intermediate position between the 35. The weakest portions 61 and 71 mainly resist the shearing force acting in the later-described press-fitting in the cylinder axis X direction, while being perpendicular to the cylinder axis X due to the vibration input (vertical direction in FIG. 1).
It is formed to have a thickness and a shape such that it will be broken by the tensile force of. In addition, both facing surfaces 3 of the connecting wall 7
Roots 72, 73 near 6, 37 are the opposite surfaces 3
6 and 37 are formed so as to be continuous with curved surfaces that smoothly bend, and both facing surfaces 3 of the connecting wall 6
The roots in the vicinity of 4, 35 are also formed so as to be continuous with a curved surface similar to the case of the connecting wall 7, although detailed illustration is omitted.

The anti-vibration bush having the above-mentioned structure is first prepared by inserting the inner cylindrical body 1 into the molding die to form the rubber elastic body 3.
Is integrally vulcanized with the inner cylindrical body 1 to form an integrally molded product 8, and then the integrally molded product 8 is formed on the inner peripheral surface 21 of the outer cylindrical body 2.
It is assembled by pressing in the cylinder axis X direction. When the rubber elastic body 3 is vulcanized and molded, a pair of insertion windows are inserted into the molding die in the direction of the cylinder axis X of the inner cylinder 1 to form the pair of draft windows 4, 5. .
At this time, each of the above-mentioned insertion dies is constituted by, for example, a pair of split dies, and a molding rubber material is inserted into a gap of a minute interval between the mating surfaces of the split dies to form a predetermined shape by a portion similar to a flash. It suffices to form both the connecting walls 6 and 7 above.

Next, the operation and effect of the first embodiment having the above structure will be described.

When the integrally molded product 8 is pressed into the outer cylindrical body 2 in the direction of the arrow in FIG. 2 during the assembly of the vibration-proof bushing, the outer peripheral surface 38 of the rubber elastic body 3 becomes the outer cylindrical body 2 of the outer cylindrical body 2. Due to the friction with the inner peripheral surface 21, a resistance force is applied in a direction relatively opposite to the press-fitting direction of the inner cylindrical body 1. At this time, since the two open windows 4 and 5 are connected to each other in the direction orthogonal to the cylinder axis X by the connecting walls 6 and 7 at the substantially central positions in the circumferential direction, the both open windows 4 and 5 are formed. The resistance force received by the outer peripheral surface 38 of the rubber elastic body 3 in the range is transmitted to the rubber elastic body 3 on the inner peripheral side via the connecting walls 6 and 7. As a result, the outer peripheral side portion of the inner peripheral side portion of the rubber elastic body 3 which is separated from the inner peripheral side portion by the existence of the both vent window portions 4 and 5 is supported, and both solid portions 30 and 30 are supported. It is possible to avoid or suppress the delay in the advance of the outer peripheral surface 38 in the above-described outer peripheral surface 38 in the formation range of the punched window when press-fitting. Therefore, the outer peripheral surface 38 in the above-mentioned draft window forming range
And the degree of progress of press fitting with the outer peripheral surface 38 in the formation range of both solid parts 30, 30 can be made substantially the same, and the part of the above-mentioned draft window forming range in the flange part 33 on the front end side in the press fitting direction. The portion of the solid portion forming range and the portion of the solid portion forming range can be taken out from the front end of the outer cylindrical body 2 in the press-fitting direction and engaged with each other almost at the same time. As a result, in the case of the conventional anti-vibration bush without both the connecting walls 6 and 7 (see FIG. 9), the progress of the press-fitting of the outer peripheral surface of the rubber elastic body c in the draft window forming range g, g is made solid. In this embodiment, the phenomenon of biting of the flange portion e of the draft window forming ranges g and g, which may occur due to the relative delay of the forming ranges h and h relative to the outer peripheral surface, is reliably prevented in the present embodiment. Therefore, the assembling work can be facilitated, speeded up, and the number of steps can be reduced.

Then, when the inner cylinder 1 and the outer cylinder 2 are used in a state where they are attached to the vibration source or the vibration receiving portion, vibration is transmitted from the side of the outer cylinder 2 in the vibration input direction, for example, downward in FIG. When input, the rubber elastic body 3 is deformed so that the upper window part 4 is expanded in the vertical direction and the lower window part 5 is contracted so that the outer cylindrical body 2 is moved downward relative to the inner cylindrical body 1. After the relative displacement of the outer cylindrical body 2 to the inner cylindrical body 1, the upper hollowed window 4 is contracted in the vertical direction and the lower hollowed window 5 is expanded to move the outer cylindrical body 2 upward with respect to the inner cylindrical body 1. Is relatively displaced, and this is repeated to prevent vibration. At the time of the above-mentioned vibration input, a vertical pulling force acts on each connecting wall 6, 7 with the expansion of each draft window 4, 5 in the vertical direction, and this pulling force causes each connecting wall 6, 7 to move. The weakest parts 61 and 71 are broken,
Subsequent enlarging / reducing deformation of the punched window portions 4 and 5 is performed without being affected by the connecting walls 6 and 7. For this reason, the connecting walls 6 and 7 have a cross-sectional shape so as to connect the facing surfaces 34, 35, 36 and 37 of the draft windows 4 and 5 linearly at the shortest distance as in the present embodiment. Even if it is formed, it is possible to obtain the original anti-vibration characteristic based on the deformation of each of the draft windows 4 and 5 against the vibration input.

Further, each root portion 7 of both the connecting walls 6 and 7 is
2, 73 are opposed surfaces 34, which form the punched windows 4 and 5,
Since it is formed so as to be continuous with a curved surface that smoothly bends with respect to 35, 36, 37, it is repeated for the root portions 72, 73 of the connecting walls 6, 7 as the space is deformed by the input of vibration. Even if the tensile force of the root portion acts, it is possible to prevent the stress from concentrating and suppress or prevent the occurrence of cracks at the root portions 72, 73.
It is possible to prevent the development of cracks in the rubber elastic body 3 itself due to the cracks 2, 73. As a result, it is possible to prevent the durability of the rubber elastic body 3 from decreasing due to the formation of the connecting walls 6 and 7.

Furthermore, each of the above-mentioned window parts 4, such as impact force,
5, even if a large load is applied to press the two opposing surfaces 34, 35, 36, 37 of each other into contact with each other, the contact-separation thereof does not matter before or after the breakage at the weakest portions 61, 71. It is in a state in which thin connecting walls 6 and 7 which are easily deformed are interposed therebetween. As a result, in the case of the conventional window part d without the connecting walls 6 and 7 (see FIG. 9), an abnormal noise is generated due to the pressure contact-separation between the mutually opposed surfaces i and j, which are independent of each other. This can be avoided in this embodiment.

<Second Embodiment> FIG. 4 shows an anti-vibration bush according to a second embodiment of the present invention. In this second embodiment, a connecting wall having a corrugated cross-sectional shape is provided in each of the draft windows 4 and 5. In the figure, 3a is an inner cylindrical body 1 and an outer cylindrical body 2.
Is a rubber elastic body that connects the two with each other, and 6a is integrally formed with the rubber elastic body 3a in the upper window 4 of the rubber elastic body 3a and 7a is formed in the lower window 5 of the rubber elastic body 3a. It is a thin wall connecting wall.

Similar to the first embodiment, the connecting walls 6a and 7a extend in the direction orthogonal to the cylinder axis X of the draft windows 4 and 5 over the entire area of the draft windows 4 and 5 in the cylinder axis X direction. The two opposing surfaces 34, 35, 36, 37 (in the vertical direction in FIG. 4) are connected to each other at substantially central positions in the circumferential direction. The cross-sections of the connecting walls 6a and 7a are formed so as to have a corrugated shape that expands in the left-right direction with respect to the vertical direction, and the opposing surfaces 34 and 35 of the extraction window portions 4 and 5, respectively.
It is configured to be able to expand and contract following the change in the above-mentioned vertical spacing of 36 and 37.

Further, as shown in an enlarged sectional view in FIG. 5, an intermediate portion between the opposing surfaces 34, 35, 36, 37 of the connecting walls 6a, 7a (only the connecting wall 7a is shown in FIG. 5). The bent part of the position is made thinner than other parts,
This bent portion has the same structure as that of the first embodiment, that is, the weakest portion 61a configured to withstand the shearing force in the cylinder axis X direction at the time of press-fitting and to be broken by the vertical pulling force at the time of vibration input. , 71a are formed.

Further, as shown in FIG. 5, the root portion 7 of each of the connecting walls 6a, 7a (only the connecting wall 7a is shown in FIG. 5) in the vicinity of the facing surfaces 34, 35, 36, 37.
2a and 73a are formed so as to be continuous with curved surfaces that smoothly bend with respect to the opposing surfaces 36 and 37, respectively.
Even if a repeated pulling force is applied to the root portions 72a and 73a due to the vibration input, no cracks are generated. That is, the action of the tensile force makes it difficult for stress to concentrate on a specific portion.

Since the other structure of the vibration-proof bush is the same as that of the first embodiment, the same members are designated by the same reference numerals and the description thereof will be omitted. Although not shown in FIG. 4, flange portions 33 (see FIG. 2) having the same structure as those of the first embodiment are integrally formed on the outer peripheral edges of the rubber elastic body 3a at both ends in the cylinder axis X direction. There is.

Each of the connecting walls 6a and 7a having the above-described structure has, for example, the shape of the mating surface of each of the pair of split molds that constitutes the insertion mold for forming each of the punched window portions 4 and 5, and the connecting wall 6a. ，
The rubber elastic body 3a can be integrally formed by vulcanizing the rubber elastic body 3a with a corrugated shape corresponding to 7a and using such an insertion die.

In the case of the second embodiment, the connecting walls 6a and 7a are formed in a corrugated shape so that the facing surfaces 34, 35, 36 and 37 of the draft windows 4 and 5 in the vertical direction. When the rubber elastic body 3a receives a deforming force due to vertical vibration input to the inner cylinder body 1 or the outer cylinder body 2, it is possible to expand and contract according to the change in the interval of The draft windows 4 and 5 can be freely expanded and contracted in the vertical direction without being affected by the connecting walls 6a and 7a. As a result, the original anti-vibration characteristics based on the deformation of the respective punched windows 4 and 5 can be reliably obtained.

In addition, in the second embodiment, the outer peripheral surface 38 of the rubber elastic body 3a in the area where both the window portions are formed is connected to each connecting wall 6.
Since the rubber elastic body 3a is supported by the inner peripheral side portion of the rubber elastic body 3a via a and 7a, the rubber elastic body 3a vulcanized integrally with the inner cylindrical body 1 is press-fitted into the outer cylindrical body 2. It is possible to prevent or suppress the progress delay of the outer peripheral surface 38 in the above-mentioned both window forming regions and prevent the occurrence of the biting phenomenon of the flange portion 33 (see FIG. 2) on the front end side in the press-fitting direction. Therefore, by corrugating the connecting walls 6a and 7a as in the second embodiment, it is possible to prevent the above-mentioned biting phenomenon during assembly without impairing the original anti-vibration characteristics. further,
Even when a large load is applied such that the expansion deformation of each of the draft windows 4 and 5 exceeds the maximum extension dimension of each of the connecting walls 6a and 7a, each of the connecting walls 6a and 7a is broken at the weakest portions 61a and 71a. As a result, the original anti-vibration characteristic based on the deformation of each of the punched windows 4 and 5 can be obtained more reliably. In addition, each of the connecting walls 6
Since the root portions 72a and 73a of the a and 7a are transferred to the facing surfaces 34, 35, 36 and 37 by the smooth curved surface, the root portions 72a and 7a are transferred to the facing surfaces 34, 35, 36 and 37, as in the first embodiment.
The occurrence of cracks at 3a is avoided, and the roots 72, 73
It is possible to prevent the crack from developing into the rubber elastic body 3a itself due to the crack.

<Third Embodiment> FIG. 6 shows an anti-vibration bush according to a third embodiment of the present invention. In this third embodiment, two connecting walls each having a corrugated cross-sectional shape are arranged in each of the draft windows 4 and 5. In the figure, 3b is a rubber elastic body that connects the inner cylindrical body 1 and the outer cylindrical body 2 to each other, and 6b and 6b are 7b and 7b in the upper window 4 of the rubber elastic body 3b. Are a pair of thin-walled connection walls integrally formed with the rubber elastic body 3b in the lower window part 5.

The pair of connecting walls 6b, 6b are formed in the same wavy shape as the connecting wall 6a of the second embodiment, and are located at positions separated from each other on both sides in the circumferential direction with the vibration input shaft Y interposed therebetween. The linear portions of the opposing surfaces 34, 35 extending in the entire cylinder axis X direction are connected to each other. The pair of connecting walls 7b, 7b are also formed in the same corrugation as the connecting wall 7a of the second embodiment, and are located at positions separated from each other on the left and right sides in the circumferential direction with the vibration input shaft Y interposed therebetween. The linear portions of the opposing surfaces 36, 37 extending in the entire cylinder axis X direction are connected to each other. Then, each pair of connecting walls 6b, 6b, 7b, 7b
Is the both facing surfaces 34 of the two punched window portions 4, 5, respectively.
It is configured to be able to expand and contract following changes in the vibration input direction intervals of 35, 36 and 37. Further, the pair of connecting walls 6b, 6b, 7b, 7b are formed with the weakest portions having the same configuration as in the second embodiment, and the root portions of the respective connecting walls 6b, 6b, 7b, 7b, 7b, 7b, 7b, 7b. It is formed so as to transition to 37 with a smooth curved surface.

Since the other structure of the vibration-proof bush is the same as that of the first embodiment, the same members are designated by the same reference numerals and the description thereof will be omitted. Although not shown in FIG. 6, flange portions 33 (see FIG. 2) having the same structure as those of the first embodiment are integrally formed on the outer peripheral edges of both ends of the rubber elastic body 3b in the cylinder axis X direction. There is.

Each pair of connecting walls 6b, 6b having the above structure,
7b and 7b are, for example, three divided dies which are insertion dies for forming the respective opening windows 4 and 5, and the shape of each mating surface of the adjacent divided dies is the above-mentioned connecting walls 6b, 6b and 7b. ，
The rubber elastic body 3b can be integrally formed by vulcanization molding using a corrugated shape corresponding to 7b and using an insertion die composed of such three divided dies.

In addition, in the case of the third embodiment, in addition to the operation and effect of the second embodiment, each pair of connecting walls 6b, 6
By b, 7b, 7b, the facing surfaces 34, 35, 36, 37 of the draft windows 4, 5 are connected at two positions separated from each other in the circumferential direction. In order to support the outer peripheral surface 38 of the rubber elastic body 3b on the inner peripheral side of the rubber elastic body 3b, one connecting wall 6a, 7a is provided for each of the punched windows 4, 5 of the second embodiment. It is possible to support with a higher supporting rigidity as compared with the case where it is performed. This prevents the occurrence of a delay in the advance of the outer peripheral surface 38 in the above-mentioned window forming region when the integrally molded product of the inner cylindrical body 1 and the rubber elastic body 3b is press-fitted into the outer cylindrical body 2. As compared with the above case, it is possible to more reliably achieve the prevention of the occurrence of the biting phenomenon of the flange portion 33 in the formation range of each of the above-mentioned removal window portions on the front end side in the press-fitting direction.

<Fourth Embodiment> FIG. 7 shows an anti-vibration bush according to a fourth embodiment of the present invention. In the fourth embodiment, a connecting wall having an oblique cross-sectional shape is arranged in each of the draft windows 4 and 5. In the figure, 3c is a rubber elastic body that connects the inner cylindrical body 1 and the outer cylindrical body 2 to each other, 6c is inside the window 4 on the upper side of this rubber elastic body 3c, and 7c is on the lower side. The rubber elastic bodies 3 are respectively provided in the window parts 5.
It is a thin connecting wall integrally formed with c.

The connecting wall 6c is located at a predetermined distance from the vibration input axis Y of the top surface 34 of the stopper portion 31 in the vibration input direction of the extraction window portion 4 to the right side in the circumferential direction. With respect to the vibration input shaft Y, a linear portion in the entire cylinder axis X direction and a linear portion in the entire inner surface 35 spaced apart from the vibration input shaft Y by a predetermined dimension in the circumferential direction on the left side in the cylinder axis X direction are arranged. It is formed so as to extend obliquely and connect to each other. Further, the connecting wall 7c is a cylinder located at a predetermined distance leftward in the circumferential direction from the vibration input axis Y of the top surface 36 of the stopper portion 32 among the opposing surfaces 36 and 37 of the extraction window portion 5 in the vibration input direction. A linear portion in the entire area in the X-axis direction and a linear portion in the entire cylindrical surface in the X-axis direction in the inner surface 37 at a predetermined distance from the vibration input axis Y to the right in the circumferential direction are oblique to the vibration input axis Y. Are formed so as to extend to and are connected to each other. In other words, both facing surfaces 34 of both the above-mentioned window parts 4 and 5 due to the vibration input,
It is easy to follow the expansion and contraction of the vibration input direction intervals of 35, 36, and 37. In addition, the connection walls 6c,
7c is formed with the weakest portion having the same structure as that of the first embodiment, and the root portions of the weakest portions are the facing surfaces 34, 3 respectively.
5, 36 and 37 are formed so as to move with a smooth curved surface.

Since the other structures of the vibration-proof bush are the same as those of the first embodiment, the same members are designated by the same reference numerals and the description thereof will be omitted. Although not shown in FIG. 7, flange portions 33 (see FIG. 2) having the same structure as those of the first embodiment are integrally formed on the outer peripheral edges of both ends of the rubber elastic body 3c in the cylinder axis X direction. There is.

Each of the connecting walls 6c and 7c having the above-described structure has, for example, a shape of a mating surface of a pair of split molds that form an insertion mold for forming each of the punched window portions 4 and 5, and the connecting walls 6c and 7c. 7
It can be integrally formed by vulcanization molding of the rubber elastic body 3c using an insertion mold composed of such a pair of split molds in a skewed shape corresponding to c.

In addition, in the case of the fourth embodiment, in addition to the action and effect of the first embodiment, the connecting walls 6c and 7c are
Both facing surfaces 34, 35, 3 of the two punched window portions 4, 5 respectively
6 and 37 are formed so as to be able to follow the approach and separation of the vibration input direction with respect to the vibration input direction. Deformation is shown. Therefore, each of the connecting walls 6c, 7
To prevent the occurrence of the biting phenomenon of the flange portion 33 due to c,
It is possible to achieve it without impairing the original anti-vibration characteristics due to the deformation of the respective punched window portions 4 and 5.

<Other Embodiments> The present invention is based on the above first to first embodiments.
The present invention is not limited to the fourth embodiment and includes various other modified examples. That is, in the first embodiment, the connecting walls 6 and 7 are formed over the entire area in the cylinder axis X direction, but the present invention is not limited to this, and for example, as shown by 6d in FIG. ) It may be formed only on the front end side portion. That is, when the rubber elastic body 3 is press-fitted into the outer cylinder body 2, in particular, the outer peripheral surface 38 of the portion on the front end side in the press-fitting direction.
Since a strong resistance force is exerted on the outer peripheral surface 38 of each of the draft window forming regions of this portion by the connecting walls 6d and 7d (7d is not shown in FIG. 8), the draft window forming regions of the respective draft window portions are formed. This is because the progress delay of the outer peripheral surface 38 can be suppressed and the occurrence of the biting phenomenon of the flange portion 33 can be prevented. In addition, the connecting wall 6 shown by the chain double-dashed line in FIG.
As in e, the range in which the connecting wall is formed with respect to the cylinder axis X direction may be an intermediate range in the cylinder axis X direction. Even in this case, the resistance force that the outer peripheral surface 38 of the rubber elastic body 3 receives when the outer peripheral surface 38 is press-fitted into the outer cylindrical body 2 is the connecting walls 6e and 7e (7 in FIG. 8).
can be transmitted to the rubber elastic body 3 portion on the inner peripheral side via (e is not shown), and the outer peripheral surface 38 in each draft window forming range can be transmitted.
Can be suppressed compared to the case where the connecting walls 6e and 7e are not provided, and the occurrence of the biting phenomenon of the flange portion 33 can be prevented. The connecting walls 6d, 7d,
Alternatively, the aspect of the forming range of 6e and 7e in the cylinder axis X direction can be similarly applied to the second to fourth examples.

In the first embodiment, the weakest portions 61 and 71 are provided on the connecting walls 6 and 7, but the invention is not limited to this, and the weakest portions 61 and 71 may not be provided. In this case, even if the weakest part is not provided, by setting the thickness and strength of the connecting walls 6 and 7 themselves so that they can be ruptured along with the vibration input, the original vibration isolation characteristics are ensured. While preventing the bite phenomenon, that is, both can be achieved.

Also in the above second to fourth embodiments, the connecting walls 6a-
Although the weakest portions 61a and 71a are provided at 6c and 7a to 7c, the present invention is not limited to this, and the weakest portions 61a and 71a may not be provided. In this case, even if the weakest part is not provided, for example, the maximum extension dimension of the connecting walls 6a to 6c and 7a to 7c in the vibration input direction is set to be equal to or larger than the maximum deformation dimension of the expansion windows 4 and 5 on the expansion side. As a result, it is possible to prevent the biting phenomenon, that is, to achieve both at the same time while ensuring the vibration damping characteristics.

In the above-mentioned first to fourth embodiments, the shape of the pair of open windows 4 and 5 is different between the one side (upper side) and the other side (lower side) sandwiching the inner cylinder 1 in the vibration input direction. The anti-vibration characteristics on each side are different as described above, but the present invention is not limited to this, and both shapes may be the same depending on the required anti-vibration characteristics, or other shapes may be used. Good.

In the above-mentioned first to fourth embodiments, the vibration-proof bushes provided with the draft windows 4 and 5 penetrating in the cylinder axis X direction as the cavities are shown, but the invention is not limited to this, and it is not limited to this. The present invention may be applied to an anti-vibration bush provided with a concave space that is open at the end surface of the rubber elastic body in the cylinder axis X direction and that extends inward in the cylinder axis X direction, even if it does not penetrate.

Further, in the above-mentioned first to fourth embodiments, the anti-vibration bush having the pair of draft windows 4 and 5 is shown, but the present invention is not limited to this, and the number of draft windows may be one. It may be 3 or more.

Further, in the above-mentioned first to fourth embodiments,
Although the rubber elastic bodies 3 and 3a to 3c are shown as the elastic bodies, the elastic bodies are not limited to the elastic bodies and may be synthetic resin elastic bodies, for example, as long as the material provides a predetermined vibration damping characteristic. Even in this case, there are the same problems as the rubber elastic body, and the connecting wall can be formed by the same manufacturing method.

[0061]

As described above, according to the vibration-proof bushing of the invention described in claim 1, since both facing surfaces of the void are connected to each other by the connecting wall, they are separated by the presence of the void. It is possible to connect the inner peripheral portion and the outer peripheral portion of the elastic body in the empty space forming range, so that when the elastic body is press-fitted into the outer cylinder body, the elastic body outer peripheral portion in the empty space forming range is assembled. Even if a resistance force is applied in the direction opposite to the press-fitting direction due to friction with the inner peripheral surface of the outer cylindrical body, the resistance force is transmitted to the inner peripheral side of the elastic body through the connecting wall and the outer peripheral surface of the elastic body is transmitted. Therefore, it is possible to suppress or prevent the occurrence of a progress delay at the time of press-fitting the outer peripheral portion of the elastic body in the void forming range with respect to the outer peripheral portion of the elastic body in the area having no void. For this reason, it is possible to prevent the occurrence of the phenomenon of the flange portion of the elastic body being caught in the outer cylinder body due to the occurrence of the above-mentioned advance delay, and the assembly manufacturing can be performed easily and speedily.

In addition, since the connecting wall connects the linear portions extending in the cylinder axis direction of the two facing surfaces of the cavity with each other, and the connecting wall is formed thin, it is in use. In, even if vibration is input between the inner cylinder and the outer cylinder in the direction connecting the voids, the original vibration-damping characteristics based on the deformation of the voids due to extension or breakage of the connecting wall It is possible to secure it. Furthermore, even if a large load such as impact force that presses the opposing surfaces of the void is input, the press contact is made with the thin connecting wall interposed therebetween. It is possible to prevent abnormal noise from being generated when the opposing surfaces of the two opposing surfaces are pressed and separated from each other.

According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the connecting wall is provided at least in the cylinder axial direction region of the elastic body at the front end side in the press-fitting direction with respect to the outer cylinder body. Since it is formed, it is possible to effectively prevent the occurrence of the biting phenomenon of the flange portion on the front end side in the press-fitting direction when assembled by press-fitting the elastic body and the outer cylindrical body.

According to the invention described in claim 3, in addition to the effect of the invention described in claim 1, since the connecting wall is formed continuously over substantially the entire region in the cylinder axis direction of the cavity,
According to the invention described in claim 1, it is possible to surely prevent the biting phenomenon at the time of assembly and the generation of abnormal noise during use.

According to the invention described in claim 4, in addition to the effect of the invention described in claim 1, the connecting wall expands in the left-right direction with respect to the direction whose cross section is orthogonal to the cylinder axis of the inner cylinder. Since it is formed in a wavy shape, when the space deforms due to vibration input during use, the connecting wall expands and contracts as the opposing surfaces of the space move away from each other, The place can be deformed according to the input vibration without being affected by the connecting wall, and the original vibration-damping property based on the deformation of the void can be surely obtained. Therefore, it is possible to prevent the occurrence of the phenomenon of biting of the flange portion due to the existence of the void without impairing the original vibration-damping property based on the void.

According to the invention described in claim 5, in addition to the effect of the invention described in claim 1, the connecting wall has an obliquely extending cross section with respect to a direction orthogonal to the cylinder axis of the inner cylinder. Since it is formed in a line shape, the deformation of the void due to the vibration input is performed without being affected by the connecting wall, as in the case of the invention according to claim 4, and the deformation of the void is prevented. Based on this, it is possible to prevent the occurrence of the phenomenon of biting of the flange portion due to the presence of the void without impairing the original anti-vibration characteristics.

According to the invention of claim 6, in addition to the effect of the invention of claim 1, the connecting wall at the intermediate position between both facing surfaces of the void has a thinner wall thickness than other portions. Since the weakest part is formed so as to extend in the cylinder axis direction, when the elastic body is deformed due to vibration input, the connecting wall connects the opposing surfaces in a straight line at the shortest distance. Also, since the elastic body is deformed to receive a tensile force and break at the weakest portion, the void can be deformed according to the input vibration without being affected by the connecting wall. As a result, regardless of the cross-sectional shape of the connecting wall, it is possible to prevent the occurrence of the bite phenomenon of the flange portion due to the existence of the void without impairing the original vibration isolation characteristics based on the deformation of the void. You can

Further, according to the invention described in claim 7, in addition to the effect of the invention described in claim 1, the root portion of the connecting wall in the vicinity of both facing surfaces of the void is opposed to the both facing surfaces. Since it is formed so as to transition with a smoothly curved curved surface, even if repeated tensile force acts on the root of the connecting wall due to deformation of the cavity due to vibration input, concentration of stress is prevented Thus, it is possible to prevent the occurrence of cracks at the root portion. As a result, it is possible to prevent the crack from developing into the elastic body itself due to the crack in the root portion, and it is possible to prevent the durability of the elastic body from being deteriorated.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is an exploded cross-sectional view taken along the line AA of FIG.

FIG. 3 is an enlarged view of a lower connecting wall of FIG. 1.

FIG. 4 is a view corresponding to FIG. 1 showing a second embodiment.

5 is an enlarged view of the lower connecting wall of FIG. 4. FIG.

FIG. 6 is a view corresponding to FIG. 1 showing a third embodiment.

FIG. 7 is a view corresponding to FIG. 1 showing a fourth embodiment.

FIG. 8 is a view corresponding to FIG. 2 showing another aspect.

FIG. 9 is a side view showing a conventional vibration damping bush.

10 is a sectional view taken along line BB in FIG.

FIG. 11 is a view corresponding to FIG. 10 showing a biting phenomenon at the time of press fitting.

[Explanation of symbols]

1 Inner cylinder 2 Outer cylinder 3,3a, 3b, 3c Rubber elastic body (elastic body) 4,5 Opening window (vacant space) 6,6a, 6b, 6c, 6d, 6e Connection wall 7,7a, 7b , 7c Connection wall 33 Flange portion 34, 36 Top surface (opposing surface) of stopper portion 35, 37 Inner surface of facing window portion (opposing surface) 61, 61a, 71, 71a Weakest portion 72, 72a, 73, 73a Root portion X cylinder axis

Claims (7)

[Claims] 1. An inner cylinder, an outer cylinder arranged to surround the inner cylinder, and an inner peripheral surface of the outer cylinder interposed between the outer cylinder and the inner cylinder. An elastic body that connects the outer peripheral surface of the inner cylindrical body to each other is provided, and this elastic body has one or two openings that open in the end surface of the inner cylindrical body in the cylinder axial direction and extend in the cylinder axial direction.
With the above-mentioned space formed, the peripheral edges of both ends in the cylinder axis direction are expanded to form flange portions that cover both end surfaces of the outer cylinder, and the elastic body is different from the outer cylinder. A vibration-isolating bush connected to the outer cylinder by being press-fitted in the cylinder axis direction of the inner cylinder, wherein the void is opposed to each other in a direction orthogonal to the cylinder axis of the inner cylinder. An anti-vibration bush, characterized in that at least one thin connecting wall for connecting the linear portions extending in the cylinder axis direction on both opposing surfaces of the void is formed integrally with the elastic body. 2. The vibration-isolating bush according to claim 1, wherein the connecting wall is formed in at least a region of the elastic body on the front end side in the press-fitting direction of the elastic body. 3. The vibration-isolating bush according to claim 1, wherein the connecting wall is formed continuously over substantially the entire area of the cavity in the cylinder axis direction. 4. The vibration-isolating bush according to claim 1, wherein the connecting wall is formed in a corrugated shape whose lateral cross section expands in the left-right direction with respect to the direction orthogonal to the cylinder axis of the inner cylinder. 5. The vibration-isolating bush according to claim 1, wherein the connecting wall is formed in a skewed shape whose cross section extends obliquely with respect to a direction orthogonal to the cylinder axis of the inner cylinder. 6. The weakest portion having a wall thickness smaller than that of the other portion is formed on the connecting wall at an intermediate position between both facing surfaces of the void so as to extend in the cylinder axis direction. Anti-vibration bush. 7. The anti-vibration bush according to claim 1, wherein a root portion of the connecting wall in the vicinity of both facing surfaces is formed so as to be continuous with a curved surface that smoothly bends with respect to the both facing surfaces.