JP2021092267A - Liquid seal bush and method of manufacturing liquid seal bush - Google Patents

Abstract

To easily assemble an inner cylinder to the inside of an intermediate cylinder.SOLUTION: In an intermediate cylinder 13, an intermediate part 22 located on the inner side in an axial direction than both end portions in the axial direction, is equipped with a pair of end parts 35 integrally formed with both end portions in the axial direction in the intermediate cylinder, independently, and a coupling member 36 coupling the pair of end parts in the axial direction. On an outer peripheral surface facing the outside in a diametrical direction at the end part, an installation recessed portion 43 in which the coupling member is fitted is formed. Parts of side surfaces of the coupling member and the installation recessed portion is made to be inclined surfaces 52a and 54a extending in a direction inclining in both of axial and circumferential direction, and abut on or come close to each other.SELECTED DRAWING: Figure 4

Description

The present invention relates to a liquid-sealed bush and a method for manufacturing the liquid-sealed bush.

Conventionally, an outer cylinder attached to either one of a vibration generating portion and a vibration receiving portion, and an inner cylinder attached to the other and provided inside the outer cylinder, and between the outer cylinder and the inner cylinder. The provided intermediate cylinder and an elastic body connecting the outer peripheral surface of the inner cylinder and the inner peripheral surface of the intermediate cylinder are provided, and two liquid chambers and these liquid chambers are communicated with each other inside the outer cylinder. A liquid sealing bush provided with an orifice passage is known.
As this type of liquid sealing bush, for example, as shown in Patent Document 1 below, two through holes are formed in the intermediate cylinder at intervals in the circumferential direction, and elastic bodies are formed in the intermediate cylinder in the circumferential direction. A liquid chamber is defined inside the through hole by being connected to the inner peripheral surface of the intermediate portion located between the adjacent through holes and the opening peripheral edge of the through hole on the inner peripheral surface of the intermediate cylinder. It is known that the orifice passage is provided between the outer peripheral surface of the intermediate portion and the inner peripheral surface of the outer cylinder.

Japanese Unexamined Patent Publication No. 2010-138938

However, in the conventional liquid-sealed bush, when the inner cylinder is assembled inside the intermediate cylinder prior to injection molding the unvulcanized rubber to form an elastic body, a protrusion or the like provided on the inner cylinder is formed. For example, it may be caught in an intermediate cylinder, which may make this assembly difficult.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid-sealed bush and a method for manufacturing a liquid-sealed bush in which an inner cylinder can be easily assembled inside an intermediate cylinder.

In order to solve the above problems, the present invention proposes the following means.
The liquid-sealed bush according to the present invention is attached to an outer cylinder attached to either one of a vibration generating portion and a vibration receiving portion, and an inner cylinder provided inside the outer cylinder, and the outer cylinder. An intermediate cylinder provided between the cylinder and the inner cylinder, and an elastic body connecting the outer peripheral surface of the inner cylinder and the inner peripheral surface of the intermediate cylinder are provided, and two inside the outer cylinder. A liquid sealing bush provided with a liquid chamber and an orifice passage for communicating these liquid chambers with each other, and in the intermediate cylinder, from both ends in the axial direction along the central axis of the liquid sealing bush, in the axial direction. Two through holes are formed in a portion located inside at intervals in the circumferential direction, and the elastic body is an intermediate portion of the intermediate cylinder located between the through holes adjacent to each other in the circumferential direction. The liquid chamber is defined inside the through hole by being connected to the inner peripheral surface of the through hole and the opening peripheral edge of the through hole on the inner peripheral surface of the intermediate cylinder, and the orifice passage is formed by the intermediate portion. The intermediate portion is provided between the outer peripheral surface of the outer cylinder and the inner peripheral surface of the outer cylinder, and the intermediate portion is paired with a pair of end portions integrally formed with both ends in the axial direction of the intermediate cylinder. A mounting recess for fitting the connecting member is formed on an outer peripheral surface of the end portion facing outward in the radial direction, and the connecting member and the connecting member are provided. A part of the side surface of each of the mounting recesses is an inclined surface extending in a direction in which it is inclined in both the axial direction and the circumferential direction, and is in contact with or close to each other.

According to the present invention, the intermediate portion includes a pair of end portions integrally formed with both ends in the axial direction of the intermediate cylinder, and a connecting member for axially connecting the pair of end portions. Therefore, before the pair of end portions are axially connected via the connecting member, the through hole formed in the intermediate cylinder can be opened in the axial direction. Therefore, even if the inner cylinder is provided with protrusions or the like, for example, with the protrusions or the like positioned between the both ends in the axial direction of the intermediate cylinder, both ends in the axial direction of the intermediate cylinder may be provided. By moving the protrusions and the like so that they are close to each other in the axial direction and the protrusions and the like are located inside the through hole, the inner cylinder is moved to the inside of the intermediate cylinder without causing the protrusions and the like to interfere with the intermediate cylinder. Can be assembled to. As a result, when the inner cylinder is assembled inside the intermediate cylinder prior to injection molding the unvulcanized rubber to form an elastic body, the protrusions and the like provided on the inner cylinder interfere with the intermediate cylinder. It becomes possible to make it difficult, and this assembly can be easily performed.
Since the intermediate portion includes a pair of end portions integrally formed with both ends in the axial direction of the intermediate cylinder and a connecting member for connecting the pair of end portions in the axial direction, the connecting member can be formed. If the axial lengths are different, the axial length of the liquid sealing bush can be different even if the axial end of the intermediate cylinder and the member integrally formed with the end are the same. This makes it possible to easily obtain a plurality of types of liquid-sealed bushes having different axial lengths.
Since a part of the side surface of each of the connecting member and the mounting recess is an inclined surface extending in a direction in which it is inclined in both directions in the axial direction and the circumferential direction, and is in contact with or close to each other, a pair of ends. When the portions are connected in the axial direction via the connecting member, the relative circumferential and axial positions of the connecting member and the end portion can be easily and accurately determined.

A part of the side surface of each of the connecting member and the mounting recess may be in contact with each other, and the rest may be separated from each other.

In this case, since a part of the side surfaces of the connecting member and the mounting recess are in contact with each other and the rest are separated from each other, the entire side surface of the connecting member and the mounting recess is brought into contact with each other. Therefore, the liquid sealing bush can be easily formed.

The inclined surfaces of the connecting member and the mounting recess may come into contact with each other.

In this case, since the inclined surfaces of the connecting member and the mounting recess are in contact with each other, when the pair of end portions are connected in the axial direction via the connecting member, the connecting member and the end portions are relative to each other. It is possible to reliably and accurately determine each position in the circumferential direction and the axial direction.

The mounting recess may be formed non-penetrating in the radial direction and may have a bottom surface facing outward in the radial direction.

In this case, since the mounting recess is formed so as not to penetrate in the radial direction and has a bottom surface facing outward in the radial direction, when the pair of end portions are connected to each other in the axial direction via the connecting member, The relative radial positions of the connecting member and the end portion can be easily and accurately determined.

In the method for manufacturing a liquid-sealed bush according to the present invention, an unvulcanized rubber is injection-molded to form the elastic body in a state where the inner cylinder is arranged inside the intermediate cylinder, and the intermediate cylinder and the inner cylinder are formed. A liquid seal having an injection step of forming a main body rubber in which the cylinders are connected via the elastic body and a press-fitting step of press-fitting the main body rubber into the outer cylinder to form the liquid seal bush of the present invention. A method for manufacturing a bush, wherein a part of the side surfaces of the connecting member and the mounting recess is brought into contact with each other during the injection step, and the rest is axially spaced from each other so as to leave a gap in the axial direction. In the state of being separated from each other, an axial compression force is applied to the intermediate cylinder, and a part of the side surfaces of the connecting member and the mounting recess is slidably contacted with each other, and the axial gap in the remaining portion. After narrowing, the unvulcanized rubber is injection-molded to form the elastic body.

According to the present invention, during the injection process, an axial compressive force is applied to the intermediate cylinder to make a part of the side surfaces of the connecting member and the mounting recess slide in contact with each other while narrowing the axial gap in the remaining portion. After that, since the unvulcanized rubber is injected to form the elastic body, it is possible to prevent the unvulcanized rubber from entering the outer edge of the intermediate cylinder in the axial direction.
That is, when a compressive force in the axial direction is applied to the intermediate cylinder to bring a part of the side surfaces of the connecting member and the mounting recess into sliding contact with each other, an axial reaction force is generated in this portion, and the intermediate cylinder has a reaction force in the axial direction. The axial outer end opening edge of the intermediate cylinder is pressed against the press that presses the axial outer end opening edge in the axial direction and applies an axial compressive force to the intermediate cylinder, and the press and the intermediate cylinder are axially oriented. It is possible to suppress the formation of a gap between the outer end and the opening edge of the.

According to the present invention, the inner cylinder can be easily assembled inside the intermediate cylinder.

It is sectional drawing in the central part in the axial direction of the liquid sealing bush which concerns on one Embodiment of this invention. FIG. 1 is a cross-sectional view taken along the line II-II of FIG. It is the figure which looked at the through hole from the outside in the radial direction in the state which the inner cylinder was assembled inside the intermediate cylinder. It is the figure which looked at the intermediate part from the outside in the radial direction in the state which the inner cylinder was assembled inside the intermediate cylinder. It is a cross-sectional view of a part of the 1st annular protrusion. It is a cross-sectional view of the position corresponding to the VI-VI line arrow view shown in FIG. 4 in the liquid-sealed bush according to the embodiment of the present invention.

Hereinafter, the liquid sealing bush according to the embodiment of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the liquid sealing bush 1 is attached to the outer cylinder 11 attached to one of the vibration generating portion and the vibration receiving portion, and to the other, and inside the outer cylinder 11. An elastic body 14 that connects the inner cylinder 12 provided, the intermediate cylinder 13 provided between the outer cylinder 11 and the inner cylinder 12, the outer peripheral surface of the inner cylinder 12 and the inner peripheral surface of the intermediate cylinder 13. , And two liquid chambers 15 and an orifice passage 16 that communicates these liquid chambers 15 with each other are provided inside the outer cylinder 11.

In the illustrated example, two orifice passages 16 are provided. A liquid such as ethylene glycol, water, or silicone oil is sealed in the liquid chamber 15 and the orifice passage 16. The number of orifice passages 16 may be one.
The liquid is injected into the liquid chamber 15 and the orifice passage 16 by communicating, for example, the liquid chamber 15 and the orifice passage 16 with a sealed tank in which the liquid is stored in a depressurized state.

The outer cylinder 11, the inner cylinder 12, and the intermediate cylinder 13 are arranged coaxially with the common axis (central axis) O. Hereinafter, the direction along the common axis O is referred to as an axial direction, the direction intersecting the common axis O when viewed from the axial direction is referred to as a radial direction, and the direction orbiting around the common axis O is referred to as a circumferential direction. In the axial direction, the central portion side of the liquid sealing bush 1 is referred to as the inside, and the side away from the central portion of the liquid sealing bush 1 is referred to as the outside.
The central portions of the outer cylinder 11, the inner cylinder 12, the intermediate cylinder 13, the elastic body 14, the liquid chamber 15, and the orifice passage 16 in the axial direction coincide with each other.

The inner cylinder 12 includes a first cylinder 12a, a second cylinder 12b that surrounds the first cylinder 12a from the outside in the radial direction, an outer peripheral surface of the first cylinder 12a, and an inner peripheral surface of the second cylinder 12b. It is provided with a connecting rubber 12c for connecting the above. When viewed from the axial direction, the inner peripheral surface and the outer peripheral surface of the first tubular body 12a and the inner peripheral surface of the second tubular body 12b have a circular shape. The second tubular body 12b is made of, for example, a synthetic resin material. The inner cylinder 12 does not have to have the connecting rubber 12c. Further, the first tubular body 12a and the second tubular body 12b may be integrally formed.

The intermediate cylinder 13 is made of, for example, a synthetic resin material. The intermediate cylinder 13 is fitted in the outer cylinder 11. A covering rubber 26 is provided on the outer peripheral surface of the intermediate cylinder 13. The coated rubber 26 is integrally formed with the elastic body 14. The covering rubber 26 is in pressure contact with the inner peripheral surface of the outer cylinder 11.

In the intermediate cylinder 13, two through holes 13a are formed at portions located inside in the axial direction from both ends in the axial direction at intervals in the circumferential direction. In the illustrated example, the two through holes 13a are formed to have the same shape and the same size. The two through holes 13a face each other in the radial direction over the entire area. The two through holes 13a do not have to face each other in the radial direction. The through holes 13a are formed in the entire axial direction in the portion of the intermediate cylinder 13 located inside the axial direction from both ends in the axial direction.

Hereinafter, the portion of the intermediate cylinder 13 that is located inside the axial direction from both ends in the axial direction and is located between the through holes 13a that are adjacent to each other in the circumferential direction is referred to as an intermediate portion 22.
The axial size of the intermediate portion 22 is larger than the axial size at the axial end of the intermediate cylinder 13. The inner peripheral surface of each intermediate portion 22 is a flat surface extending straight in one direction in a cross-sectional view orthogonal to the common axis O over the entire length in the axial direction. As shown in FIG. 4, each intermediate portion 22 has a rectangular shape that is long in the axial direction when viewed from the radial direction.
Orifice passages 16 are separately provided between the outer peripheral surface of each intermediate portion 22 and the inner peripheral surface of the outer cylinder 11.

At least a part of the inner surface of each of the liquid chamber 15 and the orifice passage 16 is defined by a rubber material. The axial size of the liquid chamber 15 is larger than the axial size of the orifice passage 16, and the orifice passage 16 opens at the central portion of the liquid chamber 15 in the axial direction. The orifice passage 16 is a groove portion formed on the outer peripheral surface of the covering rubber 26 and extends in the circumferential direction, and is separately provided on the outer peripheral surface of each intermediate portion 22 of the intermediate cylinder 13.

The elastic body 14 is made of a rubber material. The elastic body 14 is connected to the inner peripheral surface of the intermediate portion 22 and the opening peripheral edge of the through hole 13a on the inner peripheral surface of the intermediate cylinder 13, so that the liquid chamber 15 is defined inside the through hole 13a. There is. The elastic body 14 is connected over the entire circumference of the opening peripheral edge of the through hole 13a on the inner peripheral surface of the intermediate cylinder 13. Of the elastic body 14, at least a portion connected to the opening peripheral edge of the through hole 13a on the inner peripheral surface of the intermediate cylinder 13 defines a part of the inner surface of the liquid chamber 15.

As shown in FIGS. 1 and 2, the liquid chamber 15 is provided with a stopper protrusion 17 that projects outward in the radial direction and can come into contact with the inner peripheral surface of the outer cylinder 11. The stopper protrusion 17 protrudes outward in the radial direction from the outer peripheral surface of the second tubular body 12b of the inner cylinder 12. The stopper protrusion 17 is provided at the central portion in the axial direction of each of the inner cylinder 12 and the liquid chamber 15. Of the stopper protrusions 17, at least the outer end portion in the radial direction is formed of an elastic material. In the illustrated example, the entire stopper protrusion 17 is made of a rubber material. The stopper protrusion 17 is integrally formed with the elastic body 14. A radial gap is provided between the radial outer end of the stopper protrusion 17 and the inner peripheral surface of the outer cylinder 11.

On the outer peripheral surface of the inner cylinder 12, two protrusions 12e protruding outward in the radial direction are formed at each portion that faces the through hole 13a of the intermediate cylinder 13 in the radial direction at intervals in the axial direction. Has been done. It is not necessary to form the protrusion 12e on the inner cylinder 12. Two protrusions 12e adjacent to each other in the axial direction sandwich the stopper protrusion 17 in the axial direction. The protrusion 12e is formed on the outer peripheral surface of the second cylinder 12b of the inner cylinder 12.

In the vertical cross-sectional view along the axial direction, of the surface of the protrusion 12e, the surface facing the outside in the axial direction extends inward in the axial direction from the inside to the outside in the radial direction, and the intermediate cylinder 13 It extends substantially parallel to the opening peripheral edge of the through hole 13a on the inner peripheral surface of the above. In the vertical cross-sectional view, of the surface of the protrusion 12e, the surface facing the stopper protrusion 17 along the axial direction extends straight along the radial direction and is axially separated from the stopper protrusion 17. The protrusion 12e is located inside the stopper protrusion 17 in the radial direction.

In the intermediate cylinder 13, a first annular protrusion 21 that protrudes outward in the radial direction and extends continuously over the entire circumference is provided at both ends in the axial direction located outside the liquid chamber 15 and the orifice passage 16 in the axial direction. It is formed. The first annular protrusion 21 is fitted in the outer cylinder 11. A plurality of first vertical holes 31, 32, 33, which are recessed inward in the radial direction and penetrate in the axial direction, are formed on the outer peripheral surface of the first annular protrusion 21 at intervals in the circumferential direction. The first vertical holes 31 to 33 are partially filled with the covering rubber 26, and the covering rubber 26 straddles the outer peripheral surface of the first annular protrusion 21 in the axial direction. A part of the covering rubber 26 is filled in all of the plurality of first vertical holes 31 to 33. The inner peripheral surface of the outer cylinder 11 is pressed against the outer peripheral surface of the first annular protrusion 21 via the covering rubber 26.

As shown in FIG. 4, among the plurality of first vertical holes 31 to 33, the first vertical hole (hereinafter referred to as the corresponding vertical hole) 31 having the same position in the circumferential direction as the intermediate portion 22 is the other first vertical hole. The axial length is longer than the holes 32 and 33. The depth (diameter size) of the corresponding vertical hole 31 is deeper than the depth of the other first vertical holes 32 and 33. The inner surface of the corresponding vertical hole 31 is connected to the outer peripheral surface of the intermediate portion 22 without a step in the axial direction. The width (magnitude in the circumferential direction) of the inner end portion in the axial direction of the corresponding vertical hole 31 becomes narrower toward the inside in the axial direction.

A plurality of corresponding vertical holes 31 are provided in the first annular protrusion 21 in each portion having the same position in the circumferential direction as the two intermediate portions 22. Corresponding vertical holes 31 are provided in the first annular protrusion 21 at the same positions in the circumferential direction as the intermediate portion 22 at the same intervals in the circumferential direction. One corresponding vertical hole 31 is provided in the first annular protrusion 21 at the same position as the central portion in the circumferential direction of the intermediate portion 22 in the circumferential direction.

Here, as shown in FIGS. 3 and 5, the intermediate cylinder 13 is provided with a vertical parting line PL extending in the axial direction at a position separated from the first vertical holes 31 to 33 in the circumferential direction. ..
Of the plurality of first vertical holes 31 to 33, the size of the first vertical hole (hereinafter referred to as a proximity vertical hole) 32 located closest to the vertical parting line PL in the circumferential direction is the size of the other first vertical hole. It is larger than the size of 31 and 33 in the circumferential direction. Of both end faces in the circumferential direction of the proximity vertical hole 32, the inclination angle of one end surface 32a far from the vertical parting line PL with respect to the radial direction is larger than the inclination angle of the other end surface 32b close to the vertical parting line PL with respect to the radial direction. ing. It should be noted that each of these inclination angles is the smaller angle of the radial angle. Of the plurality of first vertical holes 31 to 33, the depth of the proximity vertical holes 32 is shallower than the depths of the other first vertical holes 31 and 33. The depth of the proximity vertical hole 32 becomes shallower as the distance from the vertical parting line PL increases in the circumferential direction. In a cross-sectional view orthogonal to the common axis O, the length of the one end surface 32a is longer than the length of the other end surface 32b.

On the outer peripheral surface of the first annular protrusion 21, the radial position of the portion (hereinafter referred to as the mold split portion) 21a located on the vertical parting line PL is the first vertical holes 31 to 33 adjacent to each other in the circumferential direction. It is located inward in the radial direction from the other protruding parts located between each other. The mold split portion 21a has a flat surface. The size of the mold split portion 21a in the circumferential direction is the largest among the plurality of protrusions located between the first vertical holes 31 to 33 adjacent to each other in the circumferential direction on the outer peripheral surface of the first annular protrusion 21. It has become. The vertical parting line PL is located at the center of the mold split portion 21a in the circumferential direction.

At both ends of the intermediate cylinder 13 in the axial direction, the portions located outside the first annular protrusion 21 and the vertical parting line PL in the axial direction project outward in the radial direction, extend in the circumferential direction, and extend outward. A second annular protrusion 24 fitted in the cylinder 11 is formed.
In the intermediate cylinder 13, a lateral parting line (not shown) extending in the circumferential direction is provided at a portion of the second annular protrusion 24 that is connected to the inner end surface in the axial direction. That is, in the intermediate cylinder 13, the portion including the second annular protrusion 24 located outside in the axial direction with respect to the inner end surface in the axial direction of the second annular protrusion 24 is a molding die that moves in the axial direction. In addition, in the intermediate cylinder 13, the first annular protrusion 21 and the end portion 35 located inside in the axial direction with respect to the inner end surface in the axial direction of the second annular protrusion 24 are included and connected to each other. The portion excluding the member 36 is formed by a pair of half-split molding dies in which the pair of intermediate portions 22 approach and separate from each other in the radial direction.

The radial outer ends of the first annular protrusion 21 and the second annular protrusion 24 are located at equivalent positions in the radial direction. The second annular protrusion 24 is located inside the intermediate cylinder 13 in the axial direction with respect to the outer edge of the outer end in the axial direction. Of the outer peripheral surface of the intermediate cylinder 13, a portion located on the outer side in the axial direction from the second annular protrusion 24 extends inward in the radial direction toward the outer side in the axial direction. As shown in FIG. 2, at both ends of the intermediate cylinder 13 in the axial direction, both ends of the outer cylinder 11 in the axial direction are separately crimped to portions located outside the second annular protrusion 24 in the axial direction. It is fixed.
Both ends in the axial direction on the inner peripheral surface of the intermediate cylinder 13 are radially opposed to the outer peripheral surface of the inner cylinder 12. Both ends in the axial direction on the inner peripheral surface of the intermediate cylinder 13 are located at positions in the same radial direction with respect to the outer edge in the radial direction of the protrusion 12e of the inner cylinder 12.

A plurality of second vertical holes 25, which are recessed inward in the radial direction and penetrate in the axial direction, are formed on the outer peripheral surface of the second annular protrusion 24 at intervals in the circumferential direction. The shapes and sizes of the plurality of second vertical holes 25 are the same as each other.
The second vertical hole 25 is filled with a part of the covering rubber 26, and the covering rubber 26 straddles the outer peripheral surface of the second annular protrusion 24 in the axial direction. The covering rubber 26 is provided over the entire area in the axial direction on the outer peripheral surface of the intermediate cylinder 13. All of the plurality of second vertical holes 25 are filled with a part of the covering rubber 26. The inner peripheral surface of the outer cylinder 11 is pressed against the outer peripheral surface of the second annular protrusion 24 via the covering rubber 26.

As shown in FIGS. 3 and 4, in the first annular protrusion 21 and the second annular protrusion 24 located at the same axial end on the outer peripheral surface of the intermediate cylinder 13, a plurality of second vertical holes 25 are formed. All of them, except for the second vertical hole 25, which has the same position in the circumferential direction as the vertical parting line PL, face the first vertical holes 31 to 33 in the axial direction. The second vertical hole 25, which has the same position in the circumferential direction as the vertical parting line PL, is axially opposed to a portion of the outer end surface of the first annular protrusion 21 that is connected to the mold split portion 21a.

The internal volume of the first vertical holes 31 to 33 is equal to or larger than the internal volume of the second vertical holes 25.
In the illustrated example, the circumferential and axial sizes of the first vertical holes 31 to 33 are larger than the circumferential and axial sizes of the second vertical holes 25.
For example, the circumferential and axial sizes of the first vertical holes 31 to 33 may be equal to or less than the circumferential and axial sizes of the second vertical holes 25, and the first vertical holes 31 to 31 The internal volume of 33 may be smaller than the internal volume of the second vertical hole 25.

As shown in FIG. 2, on the outer peripheral surface of the intermediate cylinder 13, each position sandwiching the liquid chamber 15 and the orifice passage 16 from both sides in the axial direction extends over the entire length in the circumferential direction and is pressure-welded to the inner peripheral surface of the outer cylinder 11. Each of the main seal protrusions 23 is provided separately. The main seal protrusions 23 are provided at both ends in the axial direction on the outer peripheral surface of the intermediate cylinder 13. The main seal protrusion 23 is provided between the first annular protrusion 21 and the second annular protrusion 24, which are located at the same axial end of the intermediate cylinder 13. The main seal protrusion 23 is formed of a rubber material and is tilted inward in the axial direction. The main seal protrusion 23 is integrally formed with the covering rubber 26.

On the outer peripheral surface of the intermediate cylinder 13, an end seal protrusion 19 extending over the entire length in the circumferential direction and pressed against the inner peripheral surface of the outer cylinder 11 is provided at a portion located outside the main seal protrusion 23 in the axial direction. There is. The end seal protrusion 19 is provided on a portion of the outer peripheral surface of the intermediate cylinder 13 located outside the second annular protrusion 24 in the axial direction, and both ends in the axial direction on the inner peripheral surface of the outer cylinder 11 are pressure-welded. doing. The thickness of the end seal protrusion 19 becomes thicker toward the outside in the axial direction. The end seal protrusion 19 is formed integrally with the covering rubber 26.

A recess 18 is formed on the outer peripheral surface of the covering rubber 26, which is continuous from the inside in the axial direction with respect to the main seal protrusion 23, and is recessed inward in the radial direction. The recess 18 extends continuously over the entire length in the circumferential direction. The recess 18 is provided between the first annular protrusion 21 and the second annular protrusion 24, which are located at the same axial end of the intermediate cylinder 13.

The elastic body 14, the stopper protrusion 17, the covering rubber 26, the main seal protrusion 23, and the end seal protrusion 19 are integrally formed by injection molding of unvulcanized rubber. These elastic bodies 14 and the like are formed by insert molding using the inner cylinder 12 and the intermediate cylinder 13 as insert products. The gate portion at the time of injection molding is provided on the inside of the main seal protrusion 23 in the axial direction, for example, the stopper protrusion 17. The gate portion at the time of injection molding may be located outside the main seal protrusion 23 in the axial direction.

As shown in FIGS. 3 and 4, the intermediate portion 22 has a pair of end portions 35 integrally formed with both ends in the axial direction of the intermediate cylinder 13 and a pair of end portions 35 in the axial direction. A connecting member 36 for connecting is provided. The outer peripheral surfaces of the end portion 35 and the connecting member 36 are connected without a step. The outer peripheral surfaces of the end portion 35 and the connecting member 36 are integrally covered with the covering rubber 26.

The end portion 35 is formed in a plate shape with the front and back surfaces facing in the radial direction. The end portion 35 has a rectangular shape that is long in the circumferential direction when viewed from the outside in the radial direction.
The connecting member 36 is formed in a plate shape in which the front and back surfaces (front surfaces) face in the radial direction. The side surface of the connecting member 36 is a wall surface extending in the radial direction. The connecting member 36 is provided over the entire length in the axial direction in the intermediate portion 22. The connecting member 36 includes a main body 51 that has a rectangular shape that is long in the circumferential direction when viewed from the outside in the radial direction, and a protruding portion 52 that protrudes outward from the main body 51 in the axial direction. The connecting member 36 has a line-symmetrical shape with respect to a vertical line extending in the axial direction through the central portion in the circumferential direction of the intermediate portion 22 when viewed from the outside in the radial direction. The connecting member 36 has a line-symmetrical shape with respect to a horizontal line extending in the circumferential direction through the central portion in the axial direction of the intermediate portion 22 when viewed from the outside in the radial direction.

Of the main body 51, the middle portion sandwiched between both ends in the axial direction in the axial direction is located inside in the radial direction from both ends in the axial direction. The middle portion of the main body 51 is inserted between the end portions 35 that are adjacent to each other in the axial direction. An axial gap is provided between the middle portion of the main body 51 and the inner end surface in the axial direction of the end portion 35. The middle portion of the main body 51 and the inner end surface of the end portion 35 in the axial direction may be brought into contact with each other. The groove portion serving as the orifice passage 16 is formed in a portion of the outer peripheral surface of the covering rubber 26 that covers the middle portion of the main body portion 51.

The protruding portions 52 are provided at both ends in the axial direction of the main body portion 51. When viewed from the outside in the radial direction, each protrusion 52 becomes smaller in the circumferential direction toward the outside in the axial direction, and exhibits a triangular shape having an apex angle pointed toward the outside in the axial direction. Of the projecting portions 52, the side surfaces of the connecting member 36 extending in the plate thickness direction, which coincide with the radial direction, are two inclined surfaces 52a extending in both axial and circumferential directions. The two inclined surfaces 52a form the apex angle. The central portions of the protruding portion 52 and the main body portion 51 in the circumferential direction coincide with each other. The circumferential length of the protruding portion 52 at the inner end portion in the axial direction is about one-third of the circumferential length of the main body portion 51.

A mounting recess 43 into which the connecting member 36 is fitted is formed on the outer peripheral surface of the end portion 35 facing outward in the radial direction. The mounting recess 43 is formed so as not to penetrate in the radial direction, and has a bottom surface facing outward in the radial direction. The side surface of the mounting recess 43 is a wall surface extending in the radial direction. In the illustrated example, the side surface of the mounting recess 43 is a wall surface that rises from the bottom surface toward the outside in the radial direction. The mounting recess 43 may penetrate the end portion 35 in the radial direction. The inner peripheral surface of the connecting member 36 is in contact with the bottom surface of the mounting recess 43.
The mounting recess 43 includes a lateral groove 53 and an overhanging recess 54.

The lateral groove portion 53 is formed at the inner end portion in the axial direction of the end portion 35 and extends in the circumferential direction. The lateral groove portion 53 is formed over the entire length in the circumferential direction at the end portion 35. The lateral groove portion 53 is open to both end faces in the circumferential direction and the inner end faces in the axial direction among the end portions 35. The outer end portion in the axial direction on the inner peripheral surface of the main body portion 51 is in contact with the bottom surface of the lateral groove portion 53.
The side surface of the lateral groove portion 53 extending in the plate thickness direction of the end portion 35, which coincides with the radial direction, extends in the circumferential direction and faces inward in the axial direction. The side surface of the lateral groove portion 53 is separated from the outer end surface in the axial direction of the main body portion 51 to the outside in the axial direction. The side surface of the lateral groove portion 53 may come into contact with the outer end surface of the main body portion 51 in the axial direction.

The overhanging recess 54 projects outward from the lateral groove 53 in the axial direction. The shape and size of the overhanging recess 54 as seen from the outside in the radial direction are the same as the shape and size of the protruding portion 52 of the connecting member 36 as seen from the outside in the radial direction. The inner peripheral surface of the protruding portion 52 is in contact with the bottom surface of the overhanging recess 54.
Of the overhanging recesses 54, the side surfaces of the end portions 35 extending in the plate thickness direction, which coincide with the radial direction, are two inclined surfaces 54a extending in the directions of inclining in both the axial direction and the circumferential direction. Each inclined surface 54a is in contact with or close to the inclined surface 52a of the protruding portion 52. In the illustrated example, the inclined surfaces 52a and 54a of the protrusion 52 and the overhanging recess 54 are in contact with each other. The inclined surfaces 52a and 54a of the protrusion 52 and the overhanging recess 54 are in contact with each other over the entire area. Of the inclined surfaces 52a and 54a of the protruding portion 52 and the overhanging recess 54, a part of the inclined surfaces 52a and 54a may be brought into contact with each other, and a part of the covering rubber 26 may be positioned in the other gap portion.
From the above, among the side surfaces of the connecting member 36 and the mounting recess 43, the inclined surfaces 52a and 54a are in contact with each other, and the axial outer end surface of the main body 51 and the side surface of the lateral groove 53 are separated from each other. ..
The side surface of the connecting member 36 includes an inclined surface 52a of the protruding portion 52, an axial outer end surface of the main body 51, and a circumferential outer end surface of the main body 51, and the side surface of the mounting recess 43 is a lateral groove portion. The side surface of 53 and the inclined surface 54a of the overhanging recess 54 are provided.

A first engaging portion 41 and a second engaging portion 42 that engage with each other are separately formed on the end portion 35 and the connecting member 36. One of the first engaging portion 41 and the second engaging portion 42 is formed in a concave shape, and the other is formed in a convex shape, so that the first engaging portion 41 and the second engaging portion 42 may be formed. It is fitted to one of them.
In the illustrated example, the first engaging portion 41 formed on the end portion 35 is formed in a convex shape, and the second engaging portion 42 formed on the connecting member 36 is formed in a concave shape. As the first engaging portion 41 and the second engaging portion 42, for example, a configuration in which they are welded to each other may be adopted.

The first engaging portion 41 projects radially outward from the bottom surface of the mounting recess 43. The radial size of the first engaging portion 41 is larger than the depth of the mounting recess 43. The first engaging portion 41 is provided at the central portion in the circumferential direction of the end portion 35. The first engaging portion 41 is provided so as to straddle the lateral groove portion 53 and the overhanging recess 54. The central portion of the first engaging portion 41 in the axial direction is located at the same axial position as the side surface of the lateral groove portion 53. The first engaging portion 41 is located on the outer side in the axial direction from the inner end surface in the axial direction at the end portion 35. The first engaging portion 41 has a rectangular shape when viewed from the outside in the radial direction, and is provided in a direction in which two of the four rectangular sides extend in the circumferential direction and the remaining two sides extend in the axial direction. ing.

Microprojections 41a that come into contact with the inner surface of the second engaging portion 42 are separately formed on both end surfaces of the first engaging portion 41 in the circumferential direction. The microprojections 41a are formed in a ridge shape extending in the radial direction. The microprojection 41a is formed over the entire length in the radial direction of the first engaging portion 41. The microprojection 41a is provided at the central portion in the axial direction of the first engaging portion 41. The size of the microprojection 41a in the circumferential direction is, for example, about 0.1 mm to 0.5 mm.
The microprojection 41a is not limited to a ridge shape extending in the radial direction, but may be formed in a dot shape or the like, and is a position of the first engaging portion 41 that is axially separated from the central portion in the axial direction. It may be provided in. The microprojection 41a does not have to be formed on the first engaging portion 41.

The second engaging portion 42 is a through hole formed in the connecting member 36. The second engaging portion 42 may be a non-penetrating recess or the like formed on the inner peripheral surface of the connecting member 36. The second engaging portion 42 is provided so as to straddle the outer end portion in the axial direction of the main body portion 51 and the protruding portion 52. The second engaging portion 42 is provided at the central portion of the connecting member 36 in the circumferential direction. The second engaging portion 42 has a rectangular shape when viewed from the outside in the radial direction, and is provided in a direction in which two of the four rectangular sides extend in the circumferential direction and the remaining two sides extend in the axial direction. ing. The axial size of the second engaging portion 42 is larger than the axial size of the first engaging portion 41.

On the outer peripheral surface of the connecting member 36, retaining protrusions 45 and 46 projecting outward in the radial direction are formed. A plurality of retaining protrusions 45 and 46 are formed on the outer peripheral surface of the connecting member 36. The retaining protrusions 45 and 46 have a circular shape when viewed from the outside in the radial direction. The outer diameters of the plurality of retaining protrusions 45 and 46 are equal to each other. As shown in FIG. 6, in the cross-sectional view orthogonal to the common axis O, the outer end faces of the retaining protrusions 45 and 46 in the radial direction extend along the inner peripheral surface of the outer cylinder 11. The radial outer end surfaces of the retaining protrusions 45 and 46 may be appropriately changed, for example, to be flat surfaces.

As shown in FIGS. 2 and 4, one of the plurality of retaining protrusions 45 and 46 (hereinafter referred to as the first retaining projection 45) is formed on the outer peripheral surface of the connecting member 36 with respect to the first engaging portion 41 and the first engaging portion 41. It is formed in a portion adjacent to the second engaging portion 42 on the outer side in the axial direction. The first retaining protrusion 45 is provided at the central portion of the connecting member 36 in the circumferential direction. The first retaining protrusion 45 is provided at the outer end portion of the protruding portion 52 in the axial direction. The radial positions of the outer end faces of the first retaining protrusion 45 and the first engaging portion 41 in the radial direction are equivalent to each other.

One of the plurality of retaining protrusions 45 and 46 (hereinafter referred to as the second retaining projection 46) is provided on the outer peripheral surface of the connecting member 36 in the circumferential direction with respect to the first engaging portion 41 and the second engaging portion 42. It is formed in the adjacent part with. The second retaining protrusions 46 are separately provided on both sides of the connecting member 36 that sandwich the first engaging portion 41 and the second engaging portion 42 in the circumferential direction. The second retaining protrusion 46 is farther from the first engaging portion 41 and the second engaging portion 42 than the first retaining protrusion 45. The second retaining protrusions 46 are provided at both ends of the connecting member 36 in the circumferential direction. The second retaining protrusions 46 are provided one by one at the four corners of the main body 51 when viewed from the outside in the radial direction. As shown in FIG. 6, the radial outer end surface of the second retaining projection 46 is inclined along the inner peripheral surface of the outer cylinder 11 in the cross-sectional view.
In addition, only one of the first retaining projection 45 and the second retaining projection 46 may be formed on the outer peripheral surface of the connecting member 36.

Then, when vibration is input to the liquid sealing bush 1, the elastic body 14 is elastically deformed and the internal volumes of the two liquid chambers 15 fluctuate, so that the liquid in the liquid chamber 15 passes through the orifice passage 16. Vibration is dampened and absorbed by circulating and causing liquid column resonance.

Next, a method of manufacturing the liquid-sealed bush 1 will be described.

A molded part in which the first annular protrusion 21, the second annular protrusion 24, and the end portion 35 are integrally formed, and the connecting member 36 are separately formed by injection molding. At this time, in the intermediate cylinder 13, the portion including the second annular protrusion 24 located outside in the axial direction with respect to the inner end surface in the axial direction of the second annular protrusion 24 is a molding die that moves in the axial direction. The intermediate cylinder 13 includes the first annular protrusion 21 and the end portion 35, which are formed by a mold and are located inside the second annular protrusion 24 in the axial direction with respect to the inner end surface in the axial direction. The portion excluding the connecting member 36 is formed by a pair of half-split molding dies in which the pair of intermediate portions 22 approach and separate from each other in the radial direction.

Next, with the protrusion 12e of the inner cylinder 12 sandwiched in the axial direction by the two molded parts, the two molded parts are brought closer to each other in the axial direction, and the protrusion 12e is inside the through hole 13a. Move it so that it is located at. Then, the connecting member 36 is arranged in the mounting recess 43, and the first engaging portion 41 is fitted into the second engaging portion 42.

Here, in the state of the molded part and the connecting member 36 before being assembled, the angle formed by the inclined surface 52a of the protruding portion 52 when viewed from the outside in the radial direction is the inclined surface 54a of the overhanging recess 54. It is larger than the angle that the eggplant makes. Therefore, as described above, simply by arranging the connecting member 36 in the mounting recess 43 and fitting the first engaging portion 41 into the second engaging portion 42, the protruding portion 52 and the overhanging recess 54 are respectively. Only a part of the inclined surfaces 52a and 54a are in contact with each other, and the outer end surface in the axial direction of the main body 51 and the side surface of the lateral groove portion 53 are largely separated from each other in the axial direction. It is displaced outward in the axial direction with respect to the connecting member 36.

In this state, while heating at least the end portion 35 and the connecting member 36, an axial compressive force is applied to the outer edge of the intermediate cylinder 13 in the axial direction over the entire area, and the protruding portion 52 and the overhanging recess 54 are each applied. While sliding the inclined surfaces 52a and 54a together, the gaps in the axial direction on the side surfaces of the connecting member 36 and the mounting recess 43 are narrowed, and then the unvulcanized rubber is injection-molded to form the elastic body 14 and the coated rubber 26 and the like. Form. As a result, the main body rubber 10 in which the intermediate cylinder 13 and the inner cylinder 12 are connected via the elastic body 14 is formed (injection step).
Then, the main body rubber 10 is press-fitted into the outer cylinder 11 (press-fitting step), and both ends of the outer cylinder 11 in the axial direction are separately crimped.

As described above, according to the liquid sealing bush 1 according to the present embodiment, the intermediate portion 22 has a pair of end portions 35 and a pair of ends, which are integrally formed with both ends in the axial direction of the intermediate cylinder 13. Since the connecting member 36 that connects the portions 35 to each other in the axial direction is provided, the penetration formed in the intermediate cylinder 13 before the pair of end portions 35 are axially connected via the connecting member 36. The hole 13a can be opened in the axial direction. Therefore, even if the inner cylinder 12 is provided with the protrusion 12e, the protrusion 12e is located between both ends of the intermediate cylinder 13 in the axial direction, for example, in the axial direction of the intermediate cylinder 13. By moving both ends so that the protrusions 12e are closer to each other in the axial direction and the protrusions 12e are located inside the through hole 13a, the inner cylinder 12 is placed in the middle without causing the protrusions 12e to interfere with the intermediate cylinder 13. It can be assembled inside the cylinder 13. As a result, when the inner cylinder 12 is assembled inside the intermediate cylinder 13 prior to injection molding the unvulcanized rubber to form the elastic body 14, the protrusion 12e provided on the inner cylinder 12 is inserted in the middle. It becomes possible to make it difficult for the cylinder 13 to interfere with the cylinder 13, and this assembly can be easily performed.

The intermediate portion 22 includes a pair of end portions 35 integrally formed with both ends in the axial direction of the intermediate cylinder 13, and a connecting member 36 for axially connecting the pair of end portions 35 to each other. Therefore, if the axial lengths of the connecting members 36 are different, even if the axial end portion of the intermediate cylinder 13 and the member integrally formed with the end portion 35 are the same, the shaft of the liquid sealing bush 1 It is possible to make the lengths in different directions, and it is possible to easily obtain a plurality of types of liquid sealing bushes 1 having different lengths in the axial direction.
A part of the side surface of each of the connecting member 36 and the mounting recess 43 is an inclined surface 52a, 54a extending in a direction in which it is inclined in both the axial direction and the circumferential direction, and is in contact with or close to each other. Therefore, when connecting the pair of end portions 35 to each other in the axial direction via the connecting member 36, the relative circumferential and axial positions of the connecting member 36 and the end portions 35 can be easily and accurately determined. Can be done.

Since some of the side surfaces of the connecting member 36 and the mounting recess 43 are in contact with each other and the rest are separated from each other, the entire side surfaces of the connecting member 36 and the mounting recess 43 are brought into contact with each other. In comparison, the liquid sealing bush 1 can be easily formed.

Since the inclined surfaces 52a and 54a of the connecting member 36 and the mounting recess 43 are in contact with each other, when the pair of end portions 35 are connected to each other in the axial direction via the connecting member 36, the connecting member 36 and The relative circumferential and axial positions of the end portion 35 can be reliably and accurately determined.

Since the mounting recess 43 is formed so as not to penetrate in the radial direction and has a bottom surface facing outward in the radial direction, when the pair of end portions 35 are connected to each other in the axial direction via the connecting member 36, The relative radial positions of the connecting member 36 and the end portion 35 can be easily and accurately determined.

According to the method for manufacturing the liquid-sealed bush 1 according to the present embodiment, an axial compressive force is applied to the intermediate cylinder 13 during the injection process, and a part of the side surfaces of the connecting member 36 and the mounting recess 43 is slid against each other. After narrowing the axial gap in the remaining part while making contact, the unvulcanized rubber is injected to form the elastic body 14 and the like, so that the unvulcanized rubber is formed on the outer edge of the intermediate cylinder 13 in the axial direction. It is possible to suppress the entry.
That is, when a compressive force in the axial direction is applied to the intermediate cylinder 13 to bring a part of the side surfaces of the connecting member 36 and the mounting recess 43 into sliding contact with each other, an axial reaction force is generated in this portion. The axial outer end opening edge of the intermediate cylinder 13 is pressed in the axial direction to apply an axial compressive force to the intermediate cylinder 13, and the axial outer end opening edge of the intermediate cylinder 13 is pressed against the press. It is possible to suppress the formation of a gap between the intermediate cylinder 13 and the outer end opening edge in the axial direction.

The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, in the above-described embodiment, the main seal protrusion 23 is tilted inward in the axial direction, but the main seal protrusion 23 may be tilted outward in the axial direction as appropriate.
Stopper protrusion 17, coated rubber 26, main seal protrusion 23, end seal protrusion 19, recess 18, first annular protrusion 21, second annular protrusion 24, first vertical hole 31, second vertical hole 25, It is not necessary to provide the first engaging portion 41, the second engaging portion 42, the first retaining protrusion 45, and the second retaining projection 46.

The liquid-sealed bush 1 may be applied to a torsion beam type rear suspension, a vehicle engine mount, a generator mount mounted on a construction machine, a machine mount installed in a factory or the like, and the like.

In addition, it is possible to replace the components in the above-described embodiment with well-known components as appropriate without departing from the spirit of the present invention, and the above-mentioned modifications may be appropriately combined.

1 Liquid sealing bush 10 Main body rubber 11 Outer cylinder 12 Inner cylinder 13 Intermediate cylinder 13a Through hole 14 Elastic body 15 Liquid chamber 16 Orifice passage 22 Intermediate part 35 End part 36 Connecting member 43 Mounting recess 52a, 54a Inclined surface O Common shaft (center) Axis)

Claims (5)

An outer cylinder attached to either one of the vibration generating portion and the vibration receiving portion, and an inner cylinder attached to the other and provided inside the outer cylinder.
An intermediate cylinder provided between the outer cylinder and the inner cylinder,
An elastic body connecting the outer peripheral surface of the inner cylinder and the inner peripheral surface of the intermediate cylinder is provided.
A liquid sealing bush provided with two liquid chambers and an orifice passage communicating these liquid chambers inside the outer cylinder.
In the intermediate cylinder, two through holes are formed at portions located inside the axial direction from both ends in the axial direction along the central axis of the liquid sealing bush at intervals in the circumferential direction.
The elastic body is formed on the inner peripheral surface of the intermediate portion of the intermediate cylinder located between the through holes adjacent to each other in the circumferential direction, and on the opening peripheral edge of the through hole on the inner peripheral surface of the intermediate cylinder. By being connected, the liquid chamber is defined inside the through hole, and the liquid chamber is defined.
The orifice passage is provided between the outer peripheral surface of the intermediate portion and the inner peripheral surface of the outer cylinder.
The middle part is
A pair of end portions integrally formed with both ends in the axial direction of the intermediate cylinder,
A connecting member for connecting the pair of the end portions in the axial direction is provided.
A mounting recess for fitting the connecting member is formed on the outer peripheral surface facing outward in the radial direction at the end portion.
A part of the side surface of each of the connecting member and the mounting recess is an inclined surface extending in a direction in which the connecting member and the mounting recess are inclined in both directions in the axial direction and the circumferential direction, and the liquid is in contact with or close to each other. Sealed bush. The liquid sealing bush according to claim 1, wherein a part of the side surfaces of the connecting member and the mounting recess is in contact with each other and the rest is separated from each other. The liquid sealing bush according to claim 2, wherein the inclined surfaces of the connecting member and the mounting recess are in contact with each other. The liquid-sealing bush according to any one of claims 1 to 3, wherein the mounting recess is formed so as not to penetrate in the radial direction and has a bottom surface facing outward in the radial direction. With the inner cylinder disposed inside the intermediate cylinder, unvulcanized rubber is injection-molded to form the elastic body, and the intermediate cylinder and the inner cylinder are connected via the elastic body. The injection process to form rubber and
It has a press-fitting step of press-fitting the main body rubber into the outer cylinder.
The method for manufacturing a liquid-sealed bush for forming the liquid-sealed bush according to any one of claims 1 to 4.
At the time of the injection step, a part of the side surfaces of the connecting member and the mounting recess is brought into contact with each other, and the rest is separated from each other in the axial direction so as to leave a gap in the axial direction. An axial compressive force is applied to the intermediate cylinder to narrow the axial gap in the rest while sliding a part of the side surfaces of the connecting member and the mounting recess, and then unvulcanized. A method for manufacturing a liquid-sealed bush, in which rubber is injection-molded to form the elastic body.

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