WO2002016800A1

WO2002016800A1 - Liquid seal vibration control device

Info

Publication number: WO2002016800A1
Application number: PCT/JP2001/003420
Authority: WO
Inventors: Hideo Tadano; Hiroaki Takahashi
Original assignee: Toyo Tire & Rubber Co., Ltd.
Priority date: 2000-08-25
Filing date: 2001-04-20
Publication date: 2002-02-28
Also published as: JP2002070926A

Abstract

A liquid seal vibration control device capable of preventing an electrolytic corrosion of an intermediate fitting and an outer tube fitting due to adhesion of electrolyte thereto, providing an excellent sealing effect between both fittings, and maintaining a satisfactory vibrationproof characteristics, wherein a rubber elastic body forming an end part wall (13) is stuck, by vulcanization, on the outer peripheral surface of an inner tube fitting (11), the intermediate fitting (16) is stuck, by vulcanization, on the outer peripheral surface of the rubber elastic body, the rubber elastic body of the end part wall (13) is routed from at least one of the axial outside end and the inside end of both end cylindrical parts of the intermediate fitting (16) to the outer peripheral surface thereof, an inside unit is inserted into the outer tube fitting (12) so as to reduce the diameter of the outer tube fitting (12), the axial end part is caulked, a clearance between the caulked ends (12a) of the intermediate fitting (16) and outer tube fitting (12) is sealed by the extension part (17) of the rubber elastic body, and a clearance between the intermediate fitting (16) and the inner peripheral surface of the outer tube fitting (12) is sealed by the extension parts (17a) and (18a) routed to the outer peripheral surface, whereby a liquid leakage can be prevented.

Description

Description Liquid-filled anti-vibration device [Technical field]

The present invention relates to a vibration damping device used for a suspension bush or an engine mount of an automobile, and more particularly to a liquid filling type vibration damping device in which a vibration damping liquid is sealed.

(Background technology)

As a liquid filling type vibration damping device in which a liquid for vibration damping is filled, for example, a device as disclosed in Japanese Patent Publication No. Hei 7-26664 has been developed.

As shown in Fig. 10, this anti-vibration device consists of an inner cylinder (1) and an outer cylinder.

(2) An end wall made of a rubber elastic body that seals between both ends thereof (3)

(3) and a liquid chamber (4) formed between the end walls (3) and (3) on both sides and filled with a liquid such as silicon oil therein.

(1) and the outer tube fitting (2) are attached to the vehicle body and the suspension link (not shown), respectively, and the vibration between them is reduced by the rubber elasticity of the end wall (3) and the liquid chamber (3). 4) It absorbs by viscous resistance of the liquid inside.

Further, in the case of this vibration isolator, the rubber elastic body constituting each end wall (3) (3) on both sides is vulcanized and bonded to the outer peripheral surface of the inner cylindrical fitting (1), and the outer peripheral surface of the rubber elastic body is formed. The surface is vulcanized and bonded to an intermediate bracket (6). The inner unit, in which the end wall (3) (3) (rubber elastic body) and the intermediate fitting (6) are integrated with the inner cylinder fitting (1), fills the liquid chamber (4). Liquid tank filled with liquid Inside, the outer cylinder (2) is reduced in diameter while the outer cylinder (2) is reduced in diameter, and both ends of the outer cylinder (2) are caulked and fixed to the intermediate bracket (6). .

By the way, the outer cylinder fitting (2) is usually used by being press-fitted and fixed to a mating member such as a suspension link. However, with the recent demand for lighter automotive parts, the mating member has been changed to aluminum. It is being studied to form the outer cylinder fitting (2) with the same aluminum. However, even when the outer tube fitting (2) is formed of aluminum, it is desired that the intermediate fitting (6) be formed of an iron-based material from the viewpoint of reduction in manufacturing cost. If this is attempted, the above-mentioned conventional vibration isolator causes the following problems.

That is, in the case of the above-described conventional vibration isolator, when the assembly is completed as shown by the enlarged portion in FIG. 12, the outer peripheral surface of the intermediate fitting (6) and the outer end in the axial direction are connected to the outer cylindrical fitting ( 2), and the contact part between the intermediate fitting (6) and the outer fitting is exposed to the outside. Therefore, when the electrolyte solution (a) such as salt water is attached to the intermediate metal fitting (6) and the outer metal fitting (2), the scientifically unsatisfactory of the intermediate metal fitting (6) and the outer metal fitting (2) is obtained. Electrolytic corrosion occurs on the metal material on the side (for aluminum and iron, on the aluminum side), which tends to cause early deterioration of the product.

The present invention has been made in view of the above, and it is possible to reliably prevent electrolytic corrosion of an intermediate metal fitting or an outer cylindrical metal fitting even when an electrolytic solution such as salt water adheres, and furthermore, to prevent the outer peripheral surface of the intermediate metal fitting from being damaged. An object of the present invention is to provide a liquid-filled type vibration damping device that has an excellent sealing effect with an outer tube fitting and can maintain good vibration damping characteristics.

[Disclosure of the Invention]

The present invention that solves the above-mentioned problem is arranged on both ends of the inner cylindrical metal fitting and the outer peripheral side thereof. A liquid-filled vibration isolator in which a liquid chamber is formed between both end walls made of rubber elastic material is sealed between the two end portions of the placed outer cylindrical metal fitting. The rubber elastic body of each end wall is vulcanized and adhered to the outer peripheral surface of the inner cylindrical fitting, and is made of a metal different from that of the outer cylindrical fitting and is substantially in the liquid chamber between the cylindrical parts at both ends. An intermediate metal fitting having a corresponding opening is vulcanized and adhered to the outer peripheral surface of the rubber elastic body, and the inner unit formed in this way is inserted into the outer cylindrical metal fitting. In the liquid filled type vibration damping device in which the portion is caulked and fixed to the intermediate metal fitting, the rubber elastic body of each end wall is wound around the axially outer end of the intermediate metal fitting and is wound around the outer end. The axially outer end of the middle fitting and the swaged end of the outer fitting are formed by the extension of the rubber elastic body. The gap is sealed, and at least one of the axially outer end of the intermediate fitting and the axially inner end of the cylindrical portion is extended around the outer peripheral surface of the cylindrical portion by extending the extended portion of the rubber-like body. A ridge portion of a ridge in the circumferential direction is formed on the outer periphery of the extending portion which is wrapped around the outer peripheral surface, and the ridge line portion is tightly sealed to the inner peripheral surface of the outer cylindrical fitting to seal. In the case of the liquid filled type vibration damping device of the present invention, the inner peripheral surface side of the intermediate fitting is completely covered with the rubber elastic body, and the rubber elastic body is provided between the axial outer end of the intermediate fitting and the swaged end of the outer cylindrical fitting. It is sealed by the extension of the body, so that the intermediate metal fitting is not exposed to the outside, so that the electrolyte such as salt water does not adhere to the intermediate metal fitting and the contact portion between the intermediate metal fitting and the outer cylindrical metal fitting. No electrolytic corrosion occurs.

In addition, the extended portion of the rubber elastic body wrapped around the outer periphery of the cylindrical portion at both ends of the intermediate fitting is strongly adhered to the inner peripheral surface of the outer tubular fitting by linear contact with the ridge line of the ridge on the outer periphery. By doing this, the gap between the inner peripheral surface of the outer cylinder fitting and the cylindrical part of the intermediate fitting can be reliably and satisfactorily maintained in a sealed state, the liquid leakage in the liquid chamber can be prevented, and the vibration isolating property can be maintained satisfactorily. The present invention also provides the liquid-filled type vibration damping device, wherein the extension portion of the rubber elastic body that does not go around the outer peripheral surface at both the axially outer end of the intermediate fitting and the axially inner end of the cylindrical portion. The diameter of the cylindrical portion is reduced via the front extension portion by the reduction of the diameter of the outer metal fitting.

In this case, the extended portion of the rubber elastic body is securely in close contact with the outer tube fitting to achieve a good sealing action, reliably prevent liquid leakage, and furthermore, the middle portion of the cylindrical portion of the intermediate member and the outer tube fitting. Since the gaps can be kept in a non-contact state, even if the electrolytic solution invades between the intermediate fitting and the outer casing, there is no possibility that electrolytic corrosion occurs in the intermediate fitting and the outer casing.

Further, the present invention provides the liquid-filled type vibration damping device, wherein the rubber elastic body is formed so that only one of the axially outer end of the intermediate metal fitting and the axially inner end of the cylindrical portion extends around the outer peripheral surface. An extension is provided, and one side thereof is reduced in diameter by the extension of the outer cylinder through the extension. Thereby, the extended portion of the rubber elastic body is securely brought into close contact with the outer cylindrical metal fitting to achieve a good sealing action, and it is possible to more reliably prevent the liquid from leaking. By forming the cylindrical portion into a tapered shape, the cylindrical portion also functions to prevent the metal tube from coming off in the axial direction.

[Brief description of drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view of the same.

FIG. 3 is a cross-sectional view showing the same embodiment in a state before assembly.

FIG. 4 is a sectional view showing still another embodiment of the present invention.

FIG. 5 is a cross-sectional view showing still another embodiment of the present invention.

FIG. 6 is an explanatory diagram of a mold used for carrying out the present invention.

FIG. 7 is a perspective view of the middle mold of the mold in FIG. FIG. 8 is a front view of an internal unit of the liquid-filled type vibration damping device according to the present invention.

FIG. 9 is a sectional view taken along line AA of FIG.

FIG. 10 is a cross-sectional view showing a conventional technique.

[Best mode for carrying out the invention]

Next, embodiments of the present invention will be described based on examples shown in the drawings. FIGS. 1 and 2 show a liquid filled type vibration damping device according to the present invention. The vibration damping device is formed in a substantially columnar shape as a whole, and is made of an inner cylindrical fitting (11) and an aluminum-made fitting disposed on the outer peripheral side thereof. The outer cylinder fitting (12) is connected at both axial ends by a pair of end walls (13) (13) made of rubber elastic material. A liquid chamber (14) filled with a liquid such as silicone oil is formed at two locations facing each other across the inner cylinder fitting (11) (the liquid chamber 14 in FIG. 1 shows only one of them). These liquid chambers (14) (14) communicate with each other by an orifice (15) described later. The orifice (15) allows the liquid to flow between the liquid chambers (14) and (14) when the inner cylinder (11) and the outer cylinder (12) are vertically displaced relative to each other. The input vibration is attenuated by applying resistance to the liquid.

Here, the rubber elastic body constituting each end wall (13) (13) on both sides is integrated in the outer peripheral region of the inner cylinder fitting (11), and the inner peripheral surface of the rubber elastic body is the inner cylinder. It is vulcanized and bonded to the outer peripheral surface of the metal fitting (11) during the molding. The following metal fittings (16) made of iron-based metal are vulcanized and bonded to the outer peripheral surface of the rubber elastic body.

That is, the intermediate fitting (16) includes two cylindrical portions (16a) and (16b) at both ends which are vulcanized and bonded to the outer peripheral surface of the end walls (13) and (13), and these cylindrical portions (16a) An opening substantially corresponding to the liquid chamber (14) (14) is formed between (16b). And a pair of beam portions (16c) connected to each other so that each beam portion (16c) has a reduced diameter mainly at the center portion with respect to the outer peripheral surfaces of both cylindrical portions (16a) (16b). It has an arc shape. Each of the beam portions (16c) forms a passage having a rectangular cross section with the inner peripheral surface of the outer cylinder fitting (12), and the passage communicates with the orifice (15) communicating between the liquid chambers (14) and (14). ). The inner peripheral side of the beam part (16c) is continuously vulcanized to the rubber elastic body of the partition part (35) (35) separating the liquid chambers (14) (14) from the end wall (13). Glued.

The inner unit in which the inner cylinder fitting (11) and the intermediate fitting (16) are integrally bonded to the rubber elastic body of the end wall (13) as described above is filled in the liquid chamber (14). In order to reduce the diameter of the outer cylinder (12) by squeezing the outer cylinder (12) in this state, the end of the outer cylinder (12) in the axial direction is squeezed. It is integrated with the outer tube fitting (12) by caulking.

Here, the rubber elastic body of the end wall (13), which is vulcanized and bonded to the intermediate fitting (16), wraps around the axially outer end of the intermediate fitting (16) as shown in FIG. The extended portion (17) of the rubber elastic body covers from the inner peripheral surface of the intermediate fitting (16) to the vicinity of the outer peripheral corner at the axially outer end of the intermediate fitting (16). This extension (17) is, as described above,

When the end of (12) is finally bent inward and crimped, as shown in Fig. 1, it is crushed by the axially crimped end (12a) of the outer tube fitting (12), A seal is provided between the axially outer end face (19) of the intermediate fitting (16) and the swaged end (12a) of the outer tubular fitting (12).

As shown in FIGS. 1 and 3, the extending portion (17) extends from the outer end (19) of the intermediate fitting (16) to the outer peripheral surface, that is, the cylindrical portion (16a).

It extends further to the outer peripheral surface (22a) (22b) of (16b). (17a) indicates an extended portion that is wrapped around the outer peripheral portion. This extension The part (17a) is provided with a ridge line part (17b) of a ridge that is continuous in the circumferential direction on the outer periphery, so that the part (17a) can be strongly adhered to the outer cylinder fitting (12) in line contact, so that the sealing action is good. To be able to fulfill.

That is, according to the configuration, the axially outer end face of the intermediate fitting (16)

In addition to sealing between the caulked end (12a) of the outer metal fitting (12) and the outer metal fitting (12), the intermediate metal fitting (16) and the outer metal fitting ( 12) in a non-contact manner, and a good seal can be maintained between the inner peripheral surface of the outer tube fitting (12) and the cylindrical portions (16a) (16b) of the intermediate fitting (16). I have.

In particular, the above effect can be obtained only by the extending portion (17a). However, in the embodiment shown in the figure, in the axially inner end of the cylindrical portion (16a) (16b) of the intermediate fitting (16), Also, the rubber elastic body is moved from the inner end surface (34) to the outer peripheral surface.

(22a) An extension is formed so as to be hung around (22b), and (18a) indicates an extension part wrapped around its outer periphery. The extended portion (18a) is formed continuously over the entire circumference including the continuous portion of the cylindrical portions (16a) (16b) and the beam portion (16c). As for the extension (18a), a ridge line (18b) of a ridge that is continuous in the circumferential direction is provided on the outer periphery of the extension (18a) in the same manner as described above, and a sealing action between the extension and the outer cylinder (12) is provided. To be able to perform well.

By providing the extension (18a) that goes around the outer periphery also on the inner end side, even if the outer cylinder fitting 12 is drawn and reduced in diameter during assembly, the inner extension is provided. The portion (18a) and the outer extending portion (17a) can favorably maintain a sealed state between the cylindrical portion (16a) (16b) of the intermediate fitting (16) and the outer tubular fitting (12), Liquid leakage can be reliably prevented. In addition, since the cylindrical portion (16a) (16b) of the intermediate fitting (16) and the outer tubular fitting (12) can be completely kept in a non-contact state, the rubber elastic body may be damaged. Even if the intermediate metal fittings (16) may come into contact with the electrolyte due to electrical shock, electrolytic corrosion of the outer metal fittings (12) is prevented.

As for the extending portions (17a) and (18a) of the rubber elastic body that go around the outer peripheral surface of the cylindrical portion (16a) (16b) of the intermediate fitting (16), as shown in FIGS. It is not limited to those formed together, but may be formed only on one side.

For example, in the embodiment of FIGS. 4 and 5, in addition to the rubber elastic body of the end wall (13) wrapping around the axially outer end of the intermediate fitting (16), the cylindrical part (16a) of the intermediate cylinder (16) The rubber elastic body of the end wall (13) is wrapped around the outer peripheral surface from the inner end surface (34) only on the axial inner end side of (16b). Also in this case, the extended portion (18a) wrapped around the outer periphery is provided with a ridge portion (18b) of a ridge that is continuous in the circumferential direction on the outer periphery, so that the sealing action can be satisfactorily performed. In the case of this embodiment, the outer cylindrical fitting (12) is drawn and reduced in diameter, so that the axially inner end face (34) of the cylindrical portion (16a) (16b) of the intermediate fitting (16). Side is reduced in diameter through the extension portion (18a) of the rubber elastic body, and becomes in a state of being tapered.

Also in this embodiment, the extension (17) can seal between the outer end surface (19) of the intermediate metal fitting (16) and the caulked end (12a) of the outer metal fitting (12). The extended portion (18a) that has been in contact with the outer tube fitting (12) can securely seal the liquid chamber (14). In addition, the tapered shape of the cylindrical portions (16a) and (16b) of the intermediate fitting (16) can also prevent the outer tubular fitting (12) from coming off in the axial direction.

Next, a method of manufacturing the vibration isolator of the above-described embodiment will be described with reference to the embodiment shown in FIGS.

As shown in Fig. 6, the inner unit is attached to the mold (20) by the inner cylinder fitting (11) and It is manufactured by setting the intermediate metal fittings (16), and vulcanizing and molding the rubber elastic bodies constituting the end walls (13) (13) in the mold (20).

The mold (20) includes an upper mold (20a) and a lower mold (20b) that open and close in the axial direction of the intermediate metal fitting (16), that is, the vertical direction in FIG.

It is composed of a pair of middle sized molds (20c) and (20c) that open and close in the radial direction of (16), that is, in the left-right direction in FIG. The procedure for closing the mold (20) is as follows: First, the lower mold in which the inner cylinder fitting (11) and the intermediate fitting (16) are set.

For (20b), the middle molds (20c) and (20c) are closed, and then the upper mold

(20a) is closed.

The upper die (20a) and the lower die (20b) are provided with substantially frustoconical protrusions (25) that are in contact with the entire inner peripheral surface of the end of the inner cylindrical fitting (11). The inner cylindrical fitting (11) is positioned by the projection (25). The distal end of the projection (25) does not come into contact with the inner peripheral surface of the inner tube fitting (11).

The upper die (20a) and the lower die (20b) have the outer edges of the cylindrical portions (16a) (16b) of the intermediate metal fitting (16), which are the axial outer ends of the intermediate metal fitting (16). Each of the cylindrical recesses (21a) and (21b) to be accommodated is formed, but these recesses (21a) and (21b) are formed slightly larger in diameter than the cylindrical portions (16a) and (16b). In addition, the distance between the bottom surfaces of the concave portions (21a) and (21b) when the mold is closed is formed to be slightly longer than the length of the intermediate fitting. That is, in the upper die (20a) and the lower die (20b), the positioning of the intermediate bracket (16) is not performed.

—On the other hand, the positioning of the intermediate bracket (16) is performed by a pair of middle dies (20c) (20c). At this time, in order to form the extension pieces (17a) and (18a) on the outer peripheral surface of the intermediate fitting (16), a medium-sized piece is attached to the inner end face (34) of the cylindrical part (16a) (16b) of the intermediate fitting (16). (20c) By contacting a part of The positioning of the bracket (16) in the mold (20) is performed.

Here, the medium size (20c) will be described in detail with reference to FIG. Note that the medium size (20c) and (20c) of the pair have substantially the same shape, and for convenience, the medium size (20c) on the right side in FIG. 6 will be described as an example.

The middle mold (20c) has a curved surface (24c) along the outer peripheral surface (22a) (22b) of the cylindrical portion (16a) (16b) and the outer peripheral surface (22c) of the beam portion (16c) of the intermediate fitting (16). ). On this curved surface (24), the beam (16c) of the intermediate fitting (16) is sandwiched, and is located between the two cylindrical parts (16a) (16b), and on the inner peripheral side of the intermediate fitting (16). A pair of bulging portions (26) (26) protruding toward each other are formed. The bulges (26) and (26) define a liquid chamber (14) between the inner unit and the outer tube fitting (12) when they are assembled.

On the upper wall (28) and lower wall (30) of the bulging portion (26), elongated projections (32) having a substantially rectangular cross section are provided in the opening and closing direction of the medium-sized (20c), that is, in the left-right direction in FIG. It is formed.

The thickness of the bulging portion (26) is the thickest at the base end on the curved surface (24) side, and gradually becomes thinner toward the inner circumferential end of the cylindrical portion (16a) (16b). (See part B in Fig. 6). Specifically, of the protrusions (32) and (32), only the portion near the curved surface (24) (see the portion C in FIG. 6) is the inner end face of each of the cylindrical portions (16a) and (16b) facing each other. (34) The thickness of each bulging portion (26) is set so as to abut the end face located on the liquid chamber (14) side, that is, the end face located on the liquid chamber (14) side.

In addition, portions of the medium-sized (20c) adjacent to the curved surface (24) are located above and below the bulging portions (26) and (26) in FIG. 7, respectively, and have cylindrical portions (16a) and (16b). Opposing portions (38a) and (38b) are formed on the outer peripheral surfaces (22a) and (22b), respectively. The upper edge (41) of the opposing portion (38a) and the lower edge (42) of the opposing portion (38b), which are both ends in the vertical direction in FIG. 7, are cut into a tapered shape over the entire circumference. It is configured so that even if the middle dies (20c) and (20c) are closed, they are separated from the two cylindrical portions (16a) and (16b).

That is, when the mold (20) is closed, the upper edge (41) and the lower edge (42) are respectively formed by the concave portions (21a) (21a) of the upper mold (20a) and the lower mold (20b). A cavity is defined to form an extension (17a) contiguous with 21b). That is, the outer edges of the cylindrical portions (16a) and (16b) are separated from the mold when the mold is closed.

At the boundary between the facing portions (38a) and (38b) and the bulging portions (26) and (26), concave grooves (40) and (40) are formed, respectively. The rubber elastic body corresponding to the extension (18a) is also vulcanized and bonded to the edge on the (14) side, that is, the outer periphery of the inner edge (34) on the cylindrical portion (16a) (16b). It is configured as follows.

In particular, the upper edge (41), the lower edge (42), and the concave groove (40) corresponding to the inner edge are formed by extending the outer edge and the inner edge of the cylindrical portion (16a) (16b). It is formed so as to form a shape corresponding to the outer shape having the ridge portions (17b) and (18b) of the protruding portions (17a) and (18a).

Incidentally, (43) is an orifice projection forming an orifice.

When the middle mold (20c) is moving in the mold closing direction or the mold opening direction, the tip of the bulging portion (26) (26) is thin, so that the intermediate fitting (16) is in the middle mold ( 20c) is not held and fixed, but when the pair of middle dies (20c) and (20c) abut against each other and the molds are closed, the liquid chamber (14) k side of each cylindrical portion (16a) (16b) Each cylindrical surface (16a) (16b) facing the upper wall (28) or lower wall (30) The protrusion (32) (see C in Fig. 6) abuts. Then, the intermediate fitting (16) is held and fixed to the middle die (20c) by these projections (32).

Therefore, as shown in FIGS. 8 and 9, a groove 36 is formed on each end wall (13) (13) by the projection (32). At both ends of the groove (36), each projection (32) is in contact with the inner end surface (34) of the cylindrical portion (16a) (16b), so that each inner end surface (34) ( 34) is exposed. However, the extending portion (18a) that goes around the outer peripheral surface of the cylindrical portions (16a) (16b) is continuous in the circumferential direction.

Also, the upper edge (41) of the opposing portion (38a) and the lower edge of the opposing portion (38b)

(42) forms a cavity continuously with the recesses (21a) and (21b) of the upper mold (20a) and the lower mold (20b), so that the outer end face of the intermediate fitting (16) is formed.

(19) is completely covered by the extension (17a). Further, an extension (18a) is formed at the concave groove (40) (40) at the boundary between the facing part (38a) (38b) and the bulge (26).

When molding the inner unit in this way, the cylindrical part of the intermediate fitting (16) is used.

The projections are formed so that the inner end faces (34) and (34) of (16a) and (16b) are pushed outward from inside toward the axial direction outside of these cylindrical parts (16a) and (16b).

(32) By supporting with (32), the outer edge of the cylindrical portion (16a) (16b), that is, the axial outer edge of the intermediate fitting (16) can be separated from the mold (20). Therefore, a sufficient amount of extension (17a) made of a rubber elastic body is added to the outer peripheral surface of the intermediate fitting (16), that is, the outer peripheral surfaces (22a) and (22b) of the cylindrical portions (16a) and (16b). When the inner unit and the outer tube bracket (12) are assembled, the intermediate unit (16) and the outer tube bracket (12) can be securely held in a sealed state. Since the metal fittings are completely out of contact, it is possible to reliably prevent the occurrence of electrolytic corrosion between the two.

Also, make sure that the middle bracket (16) is securely attached to the middle mold (20c) with the mold closed. Since it is held and fixed, it is possible to reliably prevent the set displacement that occurs when the intermediate fitting (16) is set in the mold (20).

The projections (32) are not necessarily provided on both the upper wall (28) and the lower wall (30) of the bulging portion (26). When the pair of middle dies (20c) are closed, the intermediate fittings are not provided. If (16) is held and fixed, the number can be reduced as appropriate. C Also, when the mold is closed, the opposing portions (38a) and (38b) are removed from the outer peripheral surfaces (22a) and (22b) of the cylindrical portions (16a) and (16b). The rubber elastic body may be completely separated and vulcanized and bonded to the entire outer peripheral surfaces (22a) and (22b).

As described above, according to the liquid filled type vibration damping device of the present invention, the space between the axially outer end of the intermediate fitting and the caulked end of the outer tubular fitting is sealed by the extension of the rubber elastic body on each end wall. As a result, the intermediate metal fitting is not exposed to the outside, and the electrolytic solution such as salt water does not adhere to the contact portion between the intermediate metal fitting and the outer cylindrical metal fitting, so that such electrolytic corrosion can be reliably prevented.

In addition, the extended portion of the rubber elastic body wrapped around the outer periphery of the cylindrical portion at both ends of the intermediate fitting is strongly adhered to the inner peripheral surface of the outer tubular fitting by linear contact with the ridge line of the ridge on the outer periphery. As a result, it is possible to reliably and satisfactorily maintain the seal between the inner peripheral surface of the outer cylindrical member and the cylindrical portion of the intermediate member, prevent liquid leakage in the liquid chamber, and maintain good vibration isolation characteristics.

In particular, at both the axially outer end of the intermediate metal fitting and the axially inner end of the cylindrical part, an extension part of a rubber elastic body wrapped around the outer peripheral surface is provided, and the cylindrical part is extended forward by reducing the diameter of the outer cylindrical metal fitting. When the diameter is reduced through the portion, the above-mentioned sealing action is more effectively performed, and both metal fittings can be kept in a non-contact state, so that electrolytic corrosion occurs even if an electrolytic solution enters between the metal fittings. There is no fear.

Also, only one side of the axially outer end of the intermediate metal fitting and the axially inner end of the cylindrical part is provided with a rubber elastic body extension extending around the outer peripheral surface, and one side thereof is compressed with the outer cylindrical metal fitting. In the case where the diameter is reduced via the extending portion depending on the diameter, In addition to achieving a good sealing action, the cylindrical part of the intermediate fitting has a tapered shape, so that it also functions to prevent the external fitting from coming off in the axial direction, and furthermore has excellent durability.

[Industrial applicability]

The liquid filled type vibration damping device of the present invention is suitably used as a vibration damping device used for a suspension bushing engine mount of an automobile or the like.

Claims

Scope of the request The space between both ends of the inner cylindrical member and both ends of the outer cylindrical member arranged on the outer peripheral side thereof is sealed by end walls made of a rubber elastic body, respectively. A liquid chamber having a liquid chamber formed therebetween, wherein the rubber elastic body of each end wall is vulcanized and adhered to the outer peripheral surface of the inner cylinder fitting, and An intermediate fitting made of a different metal and having an opening substantially corresponding to the liquid chamber between the cylindrical portions at both ends is vulcanized and bonded to the outer peripheral surface of the rubber elastic body. In a liquid filled type vibration damping device, which is inserted into an outer cylinder fitting, the outer cylinder fitting is reduced in diameter, and both ends thereof are caulked and fixed to the intermediate fitting.

The rubber elastic body of each end wall is wrapped around the axially outer end of the intermediate fitting, and the axially outer end of the intermediate fitting and the swaged end of the outer cylindrical fitting are extended by the extended portion of the rubber elastic body wrapped around the outer end. At least one of the axially outer end of the intermediate fitting and the axially inner end of the cylindrical portion, and extending the rubber elastic body over the outer peripheral surface of the cylindrical portion. In addition to the wraparound, a ridge portion of a circumferential ridge is formed on the outer periphery of the extension portion wrapped around the outer peripheral surface, and the ridgeline portion is brought into close contact with the inner peripheral surface of the outer cylinder to seal. Liquid filled type vibration damping device.

A rubber elastic body extending around the outer peripheral surface is provided on both the axially outer end of the intermediate fitting and the axially inner end of the cylindrical part, and the cylindrical part is moved forward by reducing the diameter of the outer cylindrical fitting. 2. The liquid filled type vibration damping device according to claim 1, wherein the diameter is reduced through an extension portion.

An extension portion of a rubber elastic body is provided around only one of the axially outer end of the intermediate fitting and the axially inner end of the cylindrical portion, and the other end is provided with an outer cylindrical fitting. The diameter is reduced through the extension part by the diameter reduction The liquid-filled type vibration damping device according to claim 1,