Liquid sealed mount device

A rubber 12 is vulcanized and bonded integrally with an engine side mounting member 11 and a barrel member 14 for caulking and fixing a diaphragm 16. A car body side mounting member 13 is formed by injection molding a resin material on the outer circumference of the rubber 12. A seal is provided between the barrel member 14 and the diaphragm 16 by caulking the peripheral edge part of the diaphragm 16 with the barrel member 14.

BACKGROUND OF THE INVENTION

The present invention relates to a liquid sealed mount device for mounting a power plant on the car body.

A liquid sealed mount device is well known in which a mounting portion made of resin to be mounted on the side of a vibration generating portion such as an engine or a car body is injection molded in a rubber for damping (e.g., refer to patent document 1 and patent document 2).

Referring toFIGS. 7A and 7B, FIGS. 1 and 3 of patent document 1 will be described below. And referring toFIGS. 8A and 7B, FIGS. 1 and 2 of patent document 2 will be described below.

FIGS. 7A and 7Bare cross-sectional views showing the conventional liquid sealed mount device (conventional example 1) .

InFIG. 7A, a damping device100as the liquid sealed mount device comprises a bolt101attached on the engine side, a mounting member104including a top plate102and a tie arm103, an elastic body106that is vulcanized and bonded on the mounting member104, a support cylinder107made of resin and disposed to surround the elastic body106, a partition member111for partitioning a liquid chamber108within the elastic body106into two chambers, a diaphragm112disposed outside the partition member111, and a cap113press fit into an opening portion of the support cylinder107to fix the partition member111and the diaphragm112.

Referring toFIG. 7B, a way for manufacturing the damping device100will be described.

First of all, the mounting member104is placed in a mold for vulcanization to vulcanize the elastic body106and bond the elastic body106to the mounting member104.

Moreover, the elastic body106and the mounting member104are positioned within an injection mold, and molten resin material is injected into the mold, and molded while the support cylinder107is bonded with the elastic body106.

And in the liquid, the partition member111and the diaphragm112are inserted into the liquid chamber108within the elastic body106and the support cylinder107, and lastly the cap113is fitted into the inside of the support cylinder107.

FIGS. 8A and 8Bare cross-sectional views showing the conventional liquid sealed mount device (conventional example 2).

InFIG. 8A, a damping device120as the liquid sealed mount device comprises a top plate121attached on the engine side and a bolt shank122attached on the top plate121, an elastic body124that is vulcanized and bonded on a lower face of the top plate121and a cylindrical insert fitting123, an outer cylindrical member126disposed on the circumferential side of the insert fitting123and the elastic body124, a partition member127and a diaphragm128disposed inside the insert fitting123, and a lid member131disposed outside the diaphragm128and caulked and fixed by the insert fitting123.

Referring toFIG. 8B, a way for manufacturing the damping device120will be described.

First of all, the top plate121and the insert fitting123are set within a mold for molding the elastic body.

Then, rubber in molten state is injected into the mold, and the elastic body124is vulcanized and bonded to the top plate121and the insert fitting123.

Also, the top plate121, the insert fitting123and the elastic body124are set within a mold for molding the outer cylindrical member. Then, resin in molten state is injected into the mold to form the outer cylindrical member126around the insert fitting123.

And the partition member127, the diaphragm128and the lid member131are inserted into the insert fitting123, and the lid member131is caulked at the lower end portion of the insert fitting123.

InFIG. 7, the metallic cap113is fitted into the opening portion of the support cylinder107made of resin to fix the partition member111and the diaphragm112, and seal the liquid chamber108. Therefore, the bonding strength between the support cylinder107and the cap113may be lowered due to a variation in press fit of the cap113into the support cylinder107, a change with the passage of time, or a temperature variation, resulting in a lower sealing ability.

Thus, if the lid member131is caulked at the lower end portion of the insert fitting123, as shown inFIG. 8, the above-mentioned problem is solved. However, in the technique ofFIG. 8, the insert fitting123is extended from the upper to lower portion of the outer cylindrical member126, and further to the portion under the outer cylindrical member126, resulting in an increased weight of the damping device120as a whole, whereby there is less effect of reducing the weight by using the outer cylindrical member126made of resin in the damping device120.

If the existent parts are made lighter, in addition to the use of resin, the weight of the damping device or the liquid sealed mount device is further reduced.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a liquid sealed mount device having a lighter weight.

In order to accomplish the above object, the present invention provides a liquid sealed mount device comprising a first mounting member, a second mounting member made of resin, a rubber bridging the gap between the first mounting member and the second mounting member, a diaphragm for forming a liquid chamber sealing the liquid together with the rubber, a partition wall for partitioning the liquid chamber into two chambers, and an orifice provided in the partition wall for communicating two liquid chambers, characterized in that the rubber is vulcanized and bonded integrally with the first mounting member and a metallic barrel member for caulking and fixing the diaphragm, and the second mounting member is formed by injection molding a resin material on the outer circumference of the rubber, in which a seal is provided between the metallic barrel member and the diaphragm by caulking the peripheral edge part of the diaphragm with the metallic barrel member.

Since the second mounting member is formed on the outer circumference of the rubber by injection molding the resin material, the partition wall is supported via the rubber by the second mounting member, and the metallic barrel member is fixed by caulking the diaphragm alone, whereby the metallic barrel member is made smaller and lighter. Also, since the metallic barrel member is vulcanized and bonded integrally with the rubber, the variation in the bonding strength or sealing ability is suppressed as compared with the convention member press fit into the resin.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Throughout the figures, the same or like parts are designated by the same reference numerals.

FIG. 1is a cross-sectional view of a liquid sealed mount device according to the invention. The liquid sealed mount device10comprises an engine side mounting member11made of metal to be mounted on the engine, a cup-like rubber12vulcanized and bonded to the engine side mounting member11, a car body side mounting member13made of resin and injection molded in the rubber12to be mounted on the car body, a metallic barrel member14having the rubber12vulcanized and bonded, a diaphragm16caulked and fixed by the barrel member14, a liquid chamber17formed by the diaphragm16and the rubber12, a liquid18sealed within the liquid chamber17, and a partition wall23for partitioning the liquid chamber17into a main liquid chamber.21and a secondary liquid chamber22.

The engine side mounting member11comprises a base portion26having the rubber12vulcanized and bonded, and a plate-like portion27stood from the base portion26to be mounted on the engine, with a mounting hole28opened in the plate-like portion27.

The rubber12comprises a cone-shaped thickened portion31serving as the cup bottom, an upper barrel portion32provided integrally with a lower portion of the thickened portion31and having a larger inner diameter than the thickened portion31, and a lower barrel portion33provided integrally with a lower portion of the upper barrel portion32and covering the outside of the barrel member14.

The car body side mounting member13comprises a cylindrical portion36covering a lower portion of the rubber12, the side protruding portions37,37extending sideways from the upper portions of the cylindrical portion36, and the mounting fittings38,38embedded in the side protruding portions37,37.

The diaphragm16comprises a cylindrical frame member41, a diaphragm main body42made of rubber and vulcanized and bonded to the inside of the frame member41, and a rubber covering portion43vulcanized and bonded to the frame member41to cover the circumferential face of the frame member41.

The covering portion43serves as a seal member between the barrel member14and the diaphragm16, in which the sealing ability with the covering portion43is increased by caulking the diaphragm16with the barrel member14.

The partition wall23comprises a partition wall main body46, and a membrane (rubber barrier membrane)48provided to close a through hole47opened in the center of the partition wall main body46. The main liquid chamber21and the secondary liquid chamber22are communicated by forming a spiral orifice51in the partition wall main body46.

The membrane48serves to decrease the dynamic spring constant by absorbing a variation in the liquid pressure within the main liquid chamber21disposed on the side of the engine side mounting member11.

Referring toFIGS. 2 to 6, a way for manufacturing the liquid sealed mount device10will be described below.

FIGS. 2A and 2Bare first action views showing the way for manufacturing the liquid sealed mount device according to the invention.

FIG. 2Ashows a state in which the rubber12is vulcanized and bonded to the engine side mounting member11and the barrel member14. This molding is a first intermediate molding10A.

InFIG. 2B, the first intermediate molding10A as shown inFIG. 2Aand the mounting fittings38,38are positioned within an injection mold, and molten resin is injected into the mold to injection mold the car body side mounting member13in the rubber12. Herein, the molding is a second intermediate molding10B. InFIG. 2A, the barrel member14has the rubber12vulcanized and bonded, but the barrel member14may be joined with resin in this process.

FIGS. 3A and 3Bare second action views showing a way for manufacturing the liquid sealed mount device according to the invention.

InFIG. 3A, the second intermediate molding10B as shown inFIG. 2Bis soaked in the liquid, and the partition wall23and the diaphragm16are inserted in succession from the lower side into the second intermediate molding10B. Since this operation is performed in the liquid, the liquid is filled in the molding during the operation.

And the barrel member14is caulked with a small load not to cause a leakage of liquid from inside the molding. That is, the barrel member14is temporarily caulked. Herein, the molding is a third intermediate molding10C.

InFIG. 3B, the third intermediate molding10C molded inFIG. 3Ais taken out of the liquid, and the barrel member14is caulked with a high load. That is, the barrel member is formally caulked. Thereby, the liquid sealed mount device10is completed. The process as indicated inFIG. 3Bmay be made in the liquid after the process as indicated inFIG. 3A.

FIG. 4is a cross-sectional view for explaining how to injection mold the car body side mounting member according to the invention, and showing a way for producing the molding as shown inFIG. 2B.

First of all, the first intermediate molding10A and the mounting fittings38,38are disposed within an injection mold60. The injection mold60includes an upper part62with an inlet port61opened, a lower part63of cylindrical shape, and a middle part64.

Molten resin is injected through the inlet port61into a cavity66.

And the second intermediate molding10B (seeFIG. 2B) is taken out of the injection mold60after resin is solidified.

InFIG. 1, since the cylindrical portion36of the car body side mounting member13covers the outside of the upper barrel portion32and the lower barrel portion33for the rubber12, the partition wall23press fit into the upper barrel portion32and the diaphragm16press fit into the lower barrel portion33are securely supported by the cylindrical portion36.

Accordingly, it is not required that the barrel member14is extended upwards to support the partition wall23, for example. Thereby, it is only necessary to support the diaphragm16by reducing the upper and lower sizes of the barrel member14. Consequently, the barrel member14is made smaller and lighter.

FIGS. 5A and 5Bare cross-sectional views for explaining how to caulk and fix the barrel member according to the invention.

FIG. 5Ashows a state immediately after the diaphragm16is press fit into the barrel member14. To temporarily fix the diaphragm16from this state, the barrel member14is bent around the entire circumference of the lower end portion as indicated by the imaginary line, whereby the diaphragm16is temporarily caulked.

And after temporary caulking, the barrel member14is bent almost at right angles around the entire circumference of the lower end portion, whereby the diaphragm16is formally caulked, as indicated inFIG. 5B.

The sealing ability between the barrel member14and the diaphragm16is attained in the resilient covering portion43by press fitting the diaphragm16into the barrel member14at the first step, and enhanced by the covering portion43by formally caulking the barrel member14at the second step.

FIG. 6is a flowchart showing a way for manufacturing the liquid sealed mount device according to the invention. InFIG. 6, STxx denotes the step number.

ST01. . Vulcanize and bond the rubber to the engine side mounting member and the barrel member (thereby producing the first intermediate molding).

ST02. . Dispose the first intermediate molding and the mounting fittings within the injection mold, and injection mold the car body side mounting member in the rubber (thereby producing the second intermediate molding).

ST03. . Press fit the partition wall and the diaphragm in succession into the second intermediate molding from the lower side in the liquid, and temporarily caulk the barrel member (thereby producing the third intermediate molding).

ST04. . Formally caulk the barrel member (thereby completing the liquid sealed mount device).

As described above inFIG. 1, with the invention, the car body side mounting member13is vulcanized and molded in the rubber12, whereby the partition wall23is supported via the rubber12by the car body side mounting member13. And since it is only required to caulk and fix the diaphragm16in the barrel member14, the barrel member14is made smaller and lighter.

Though the conventional barrel member has a complex structure, the barrel member14has a simple constitution of barrel in this invention, whereby the cost is reduced.

Moreover, in the liquid sealed mount device10of the invention, the barrel member14is temporarily caulked and then. formally caulked. Therefore, it is possible to confirm a liquid leakage after temporarily caulking the barrel member. If liquid leakage is confirmed at this time, the operation may be interrupted. Accordingly, in the case where the caulking process for the barrel member involves caulking alone, in the invention, the number of wasteful steps is less than when liquid leakage is found after caulking.

Also, the barrel member14has the rubber vulcanized and bonded on the circumferential face as described above inFIG. 1. However, the barrel member14may have the rubber vulcanized and bonded on both the inner and outer circumferential faces of the barrel member14, or on the inner circumferential face.

The above constitution of the invention has the following effects.

In the liquid sealed mount device of the invention, the rubber is vulcanized and bonded integrally with the first mounting member and the metallic barrel member for caulking and fixing the diaphragm, and the second mounting member is formed by injection molding a resin material on the outer circumference of the rubber, in which a seal is provided between the metallic barrel member and the diaphragm by caulking the peripheral edge part of the diaphragm with the metallic barrel member. Therefore, the partition wall is supported via the rubber by the second mounting member, and the metallic barrel member is fixed only by caulking the diaphragm alone, whereby the metallic barrel member is made smaller and lighter, and the liquid sealed mount device is made lighter.

Also, since the metallic barrel member is vulcanized and bonded integrally with the rubber, the variation in the bonding strength or sealing ability is suppressed as compared with the convention member press fit into the resin.