JPH0329630Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a fluid-filled mount used as a support device for an internal combustion engine or the like.

[Conventional technology]

For example, in an automobile engine, a fluid-filled mount, which is a vibration isolating device shown in Figure 2, is used to suppress changes in attitude due to rapid torque fluctuations that occur due to sudden acceleration, sudden deceleration, etc. is used. In the figure, reference numeral 1 denotes a flat center member with a mounting bolt 2 protruding outward (upward in the figure) and welded to the center, and reference numeral 3 a center member with a mounting bolt 4 mounted in the center in the opposite direction to the bolt 2 ( In other words, it is a substantially dish-shaped case member that is protruded and welded downward (in the figure), and a diaphragm 6, a partition wall 7, and an annular flange member 8 are fixed to the inside of the peripheral edge 5 of the case member 3 by caulking. . A substantially cylindrical elastic body 9 made of a rubber material is bonded between the flange member 8 and the center member 1. In other words, the center member 1 and the case member 3 are connected to each other through the elastic body 9 and the flange member 8. and are elastically connected. The partition wall 7 includes a diaphragm 6 and an elastic body 9.
A fluid chamber 10 formed between the two and filled with a working fluid.
into a first fluid chamber 10a on the elastic body 9 side and a second fluid chamber 10b on the diaphragm 6 side. In addition, between the two substantially dish-shaped plates 7a and 7b which are overlapped with each other and which constitute the partition wall 7, there are a required number of small holes 12 bored in both the plates 7a and 7b. ... forms a valve chamber 13 that communicates with both the first and second fluid chambers 10a, 10b, and within the valve chamber 13 is a disc-shaped disk that can freely reciprocate in the axial direction (vertical direction in the figure). A subdiaphragm 14 is interpolated.

The fluid-filled mount configured as described above connects either the center member 1 or the case member 3 to the machine base, and the other to the supported object such as the engine.
It absorbs vibrations between the two. This vibration absorption utilizes the vibration absorption characteristics of the elastic body 9. In addition, when relatively large amplitude and low frequency vibrations are input, the first and second vibration absorption characteristics are used depending on the direction of the input. The working fluid in one of the fluid chambers 10a and 10b flows into the valve chamber 13 through the small hole 12 and presses and moves the sub-diaphragm 14 toward the other fluid chamber. When the small hole 12 on the side of the fluid chamber is closed and stopped, the working fluid in one fluid chamber flows into the other fluid chamber through the orifice 11, that is, the elasticity of the elastic body 9 and the center member 11 The vibrations are damped by the flow resistance of the working fluid against the oscillation. When the input vibration is a high frequency vibration with a small amplitude, the working fluid flows into both fluid chambers 10.
Vibration is damped simply by flowing between a, 10b and the valve chamber 13 according to the direction of input.

[Problem that the invention attempts to solve]

However, in the conventional fluid-filled mount, since the elastic body 9 is made of a rubber material, the elastic body 9 is moved in the radial direction by the pressure of the working fluid in the first fluid chamber 10a, which changes depending on the input direction. For example, when a large load F of a certain level or more is input in the direction of the arrow, the first fluid chamber 10a
As the internal pressure increases, the elastic body 9 expands toward the outside diameter as shown by the broken line in the figure, and the working fluid "escapes", so that sufficient damping force due to flow resistance when passing through the orifice 11 is generated. It is easy to become unobtainable.

In the fluid-filled mount shown in FIG. 3, metal reinforcing rings 15 and 16 are embedded in the elastic body 9 in order to prevent the elastic body 9 from expanding and contracting in the radial direction as described above. As shown by the broken line in this mount, some degree of radial deflection is unavoidable, and with this configuration, the spring constant of the elastic body 9 in the axial direction (vertical direction in the figure) becomes high. This creates new problems.

In view of the above problems, the present invention aims to provide a fluid-filled mount that eliminates the loss of damping force when large-amplitude, low-frequency vibrations are input.

[Means for solving problems]

The fluid-filled mount of the present invention, which is a means for achieving the above object, has a center member that is fixed to either the machine base side or the supported object side, and a case member that is fixed to the other side. connected via a bellows made of a resin material, a diaphragm is stretched inside the case member, and the center member;
A fluid chamber is formed by a bellows and a diaphragm, the fluid chamber is divided into two chambers by a partition wall having an orifice, and a rubber member is connected to the outer peripheral side of the bellows to connect the center member and the case member. A cylindrical elastic body is arranged, and a cylindrical airtight space is set between the bellows and the elastic body.

[Effect]

Due to the nature of the material, bellows made of metal or resin have a characteristic that they are difficult to expand toward the outer circumference even when high pressure is applied from the inner circumference. In addition, the volume and internal pressure of the airtight space between the bellows and the elastic body disposed on the outer circumferential side of the bellows changes as the bellows expands and contracts, and as the bellows contracts and the internal pressure of the fluid chamber on the inner circumferential side increases. This increases the internal pressure of the bellows and prevents the bellows from expanding against the internal pressure of the fluid chamber.
Further, the cylindrical elastic body disposed on the outer peripheral side of the bellows has a function of protecting the bellows.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings. In addition, in this example, the second
The same reference numerals are given to the parts having the same configuration as those of the conventional example shown in FIGS.

That is, the fluid-filled mount has a first
As shown in the figure, a metal molded bellows 17 is welded 18 between the center member 1 and the flange member 8a which is caulked and fixed to the inside of the peripheral edge 5 of the case member 3. Therefore, it has an airtightly joined structure, in other words, the center member 1 and the case member 3 are elastically connected via the metal molded bellows 17 (including the flange member 8a). A cylindrical elastic body 19 made of a rubber material is arranged on the outer peripheral side of the bellows 17 to connect the center member 1 and the case member 3.
A cylindrical airtight space 20 is set between the elastic body 7 and the elastic body 19 . 8b is a second flange member for fixing the elastic body 19 to the case member 3.

The fluid-filled mount with the above configuration uses a metal molded bellows 17 instead of the conventional rubber elastic body.
Because of the material characteristics of the bellows 17, the bellows 17 is difficult to expand toward the outer circumference even if high pressure is applied to the bellows 17 from the inner circumference. Further, an airtight space 20 set between the bellows 17 and the elastic body 19 changes its volume and internal pressure as the bellows 17 expands and contracts, and the fluid chamber 1
As the internal pressure of the bellows 17 increases, it is increased to counteract the internal pressure of the fluid chamber 10a, thereby also suppressing the expansion of the bellows 17 toward the outer circumferential side.

Furthermore, the fluid-filled mount having the above configuration is
Since it has both the metal molded bellows 17 and the elastic body 19, it is possible to expand the degree of freedom in design when setting the spring constant compared to the conventional example. That is, the spring rigidity of the bellows 17 can be increased to decrease the spring rigidity of the elastic body 19, or conversely, the spring rigidity of the bellows 17 can be decreased to increase the spring rigidity of the elastic body 19, or a compromise can be achieved. In particular, when the spring stiffness of the bellows 17 is set to be small and the spring stiffness of the elastic body 19 is set to be large, buckling (breakage of the waist) of the bellows 17 can be prevented. Buckling of the bellows 17 is likely to occur when vibration is input in the F' direction in FIG. 1, that is, obliquely to the central axis.

Furthermore, the fluid-filled mount having the above configuration is
A cylindrical rubber elastic body 19 is arranged on the outer circumferential side of the metal bellows 17 so that the bellows 17 is surrounded by the elastic body 19. This can prevent the bellows from tearing and leaking the working fluid inside.

[Effect of idea]

The fluid-filled mount of the present invention has the following effects due to the above structure and operation.

A: Because a bellows made of metal or resin is used in place of the conventional rubber elastic body, due to the material characteristics of the bellows, even if high pressure is applied to the bellows from the inner circumference, the bellows will not move toward the outer circumference. Not easy to expand. In addition, the airtight space set between the bellows and the elastic body changes its volume and internal pressure as the bellows expands and contracts, and as the internal pressure of the fluid chamber increases, the internal pressure increases to counteract the internal pressure of the fluid chamber. This also makes it possible to suppress expansion of the bellows toward the outer circumference. Therefore, according to the present invention, loss in damping force due to the expansion can be prevented and the damping effect can be improved.

B When setting the spring constants of the bellows and elastic body that are installed together, if the spring stiffness of the bellows is set to be small and the spring stiffness of the elastic body is set to be large, buckling (breakage at the waist) of the bellows can be effectively prevented. can do.

C. A cylindrical rubber elastic body is placed on the outer periphery of the metal or resin bellows, and the elastic body surrounds the bellows, so if a foreign object hits the bellows, the bellows This can prevent the internal working fluid from leaking out due to tearing. The fluid-filled mount is intended to support an automobile engine as a supported body, and the foreign objects may include stones, gravel, and other objects on the road that are scattered when the automobile is running.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a fluid-filled mount according to an embodiment of the present invention, and FIGS. 2 and 3 are longitudinal sectional views of conventional fluid-filled mounts. 1...Center member, 3...Case member, 6...
... diaphragm, 7 ... partition, 8a, 8b ... flange member, 10 ... fluid chamber, 10a ... first fluid chamber, 10b ... second fluid chamber, 11 ... orifice, 17 ... metal molded bellows, 18...Welding part, 19...Elastic body, 20...Airtight space.

Claims (1)

[Scope of utility model registration request] The center member 1 fixed to either the machine base side or the supported body side and the case member 3 fixed to the other side are connected via a bellows 17 made of a metal material or a resin material. A diaphragm 6 is stretched inside the case member 3, and a fluid chamber 10 is formed by the center member 1, the bellows 17, and the diaphragm 6, and the fluid chamber 10 is divided into two chambers 10a by a partition wall 7 having an orifice 11. ,1
0b, and a cylindrical elastic body 19 made of a rubber material that connects the center member 1 and the case member 3 is arranged on the outer peripheral side of the bellows 17, and a cylindrical elastic body 19 is arranged between the bellows 17 and the elastic body 19. airtight space 20
Fluid-filled mount with .