JPH03177635A - Vibration isolator - Google Patents

Abstract

PURPOSE:To reduce the manufacturing cost by arranging an intermediate cylinder having an enlarged diameter part and a reduced diameter part between an inner cylinder and an outer cylinder, by having a sealant held between this intermediate cylinder and the outer cylinder, by hanging an elastic body over the inner cylinder and the outer cylinder, by forming a liquid chamber in this elastic body and by providing a limiting passage passing through this liquid chamber. CONSTITUTION:In a vibration isolator 10, an inner cylinder 12 and an outer cylinder 14 are arranged in parallel and an intermediate cylinder 18 is provided between them. At both ends of the intermediate cylinder 18, an enlarged diameter part 18A is formed, whose outer circumferential surface is directly brought into contact with the both end parts of the outer cylinder 14 and the inner circumferential surface is sealed with a seal rubber 50 and a ring- shaped rubber 19. A body rubber 20 is hung over the inner cylinder 12 and the intermediate cylinder 18, and a liquid chamber 26 is provided in the body rubber 20. A limiting passage 32 is provided on the outer circumference of the intermediate cylinder 18, whose one end 32A communicates to a small liquid chamber 26A and the other end 32B to a small liquid chamber 26B, and vibration is absorbed by passing resistance of the limiting passage 32. As the limiting passage 32 is sealed by the vibration proof rubber 50, an O ring and its ring groove becomes unnecessary, which reduces the manufacturing cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vibration isolating device that is provided in a vehicle body and absorbs vibrations from an engine or the like.

[Conventional technology]

As a vibration isolator used as a vehicle engine mount, cab mount, body mount, etc., an inner cylinder, an intermediate cylinder, and an outer cylinder are arranged on parallel axes, and an elastic body is stretched between the inner cylinder and the intermediate cylinder. There is a so-called Bush-type vibration isolator. In this type of vibration isolator, a plurality of branch chambers are provided in the elastic body stretched between the inner cylinder and the intermediate cylinder, and these liquid chambers are formed between the outer cylinder and the intermediate cylinder. The vibration damping effect is improved by communicating through the restricted passage.

Therefore, in order to prevent liquid leakage from the restriction passage, both axial ends 100 of the intermediate cylinder 100 are
A concave ring groove 102 is formed on the outer peripheral surface of A, and a circle ring 104 is inserted into this ring groove 102 to improve the sealing performance between the intermediate cylinder 100 and the outer cylinder 106 and prevent liquid leakage from the restriction passage 112. ing.

However, in this vibration isolator, an OIJ ring 104 is prepared separately, and a concave ring groove 10 is provided in the intermediate cylinder 100.
Since cutting work is required to form 2, the product cost increases and the production efficiency of the product is not good.

Therefore, as shown in FIG. 11, by vulcanizing and adhering rubber 108 and 110 to the inner peripheral surface of the outer cylinder 106 and the outer peripheral surface of the intermediate cylinder 100, respectively, the rubber 108 and the rubber 11O are brought into contact with each other, and the outer cylinder It is also possible to improve the sealing performance of the restriction passage 112 by adding a drawing process to the passage 106.

However, in this structure, the intermediate cylinder 100 and the outer cylinder 106 are in indirect contact via the rubber 108 and 110, so when the outer cylinder 106 is squeezed, the sealing pressure is increased due to the difference in the pressure of the squeeze process. may be different.

In addition, when the vibration isolator is attached to a vehicle and an external force is applied to the outer cylinder 106 etc. in the axial direction (left and right direction in FIG. There is a possibility that the intermediate cylinder 100 will shift in the axial direction.

[Problem to be solved by the invention]

In consideration of the above facts, the present invention aims to provide a vibration isolating device that is low in cost and has good durability.

[Means to solve the problem]

The present invention includes an inner cylinder supported by one of a vibration generating part and a vibration receiving part, and a vibration generating part and a vibration receiving part arranged outside the inner cylinder so that an axis thereof faces in the axial direction of the inner cylinder. The outer cylinder is disposed between the inner cylinder and the outer cylinder, and an enlarged diameter part is formed at both ends in the axial direction, and a reduced diameter part is formed in the middle part. an intermediate cylinder whose outer periphery is in direct contact with the inner periphery of the outer cylinder; a sealing material disposed between the intermediate cylinder and the outer cylinder and sandwiched between the outer periphery of the reduced diameter portion of the intermediate cylinder and the inner periphery of the outer cylinder; ,
It is characterized by providing an elastic body that is stretched between the inner cylinder and the intermediate cylinder, a plurality of liquid chambers formed inside this elastic body, and a restriction passage that communicates the plurality of liquid chambers. .

[Effect]

In the present invention having the above configuration, vibrations are absorbed by the internal friction of the elastic body. Vibrations that are not absorbed by the elastic body are transmitted to the liquid chamber via the elastic body, and the liquid in the liquid chamber is absorbed by moving through the restricted passage.

The restriction passage is sealed by a sealing material, and the sealing pressure of the sealing material is maintained constant by the diameter-reduced portion of the intermediate cylinder.

In addition, even if an external force is applied in the axial direction of the vibration isolator, the expanded diameter part of the intermediate cylinder is in direct contact with the inner peripheral surface of the outer cylinder, eliminating relative movement between the intermediate cylinder and the outer cylinder. It is possible to prevent misalignment between the cylinder and the cylinder.

[First Embodiment] FIGS. 1 to 4 show a vibration isolating device 10 to which the present invention is applied.
A first embodiment is shown.

As shown in FIGS. 1 and 2, in this vibration isolator (2) 0, a metal inner cylinder 12 and a metal outer cylinder 14 are arranged with parallel shafts. In this embodiment, the inner cylinder 12 is fixed to an engine (not shown) serving as a vibration generating part, and the outer cylinder 14 is fixed to a vehicle body (not shown) serving as a vibration receiving part.

As shown in FIG. 2, a thin film rubber 16 is disposed on the inner circumferential surface of the axially intermediate portion of the outer cylinder 14, and is vulcanized and bonded to the outer cylinder 14 except for a portion that is the diaphragm portion 16A. . Further, as shown in FIG. 1, seal rubber 50 as a sealing material thicker than the thin film rubber 16 is vulcanized and bonded to the outer cylinder 14 on both sides of the thin film rubber 16 in the axial direction.

The thin film rubber 16 side of the seal rubber 50 is a thick wall portion 5.
0A is formed, and a thin thin portion 50B is continuously formed on the side of the seal rubber 50 opposite to the thin film rubber 16.

An inner cylinder 12 and an outer cylinder 14 are provided between the inner cylinder 12 and the outer cylinder 14.
A metal intermediate cylinder 18 is disposed parallel to the axis. As shown in FIG. 4, enlarged diameter portions 18 are formed on the inner peripheral surface of the axial end portion 14A of the outer cylinder 14 at both axial ends of the intermediate cylinder 18.
The outer circumferential surfaces of A are in direct contact to ensure engagement between the outer cylinder 14 and the intermediate cylinder 18. A ring-shaped rubber 19 is vulcanized and adhered to the inner circumferential surface of this enlarged diameter portion 18A, and sealing is performed at two locations, the sealing rubber 50 and the rubber 19. Said enlarged diameter part 1
The end portion 14A of the outer cylinder 14 is folded back into a substantially U-shape and swaged to the end surface of the outer cylinder 14 and the rubber 19 to connect the outer cylinder 14 and the intermediate cylinder 18.
are integrated. A reduced diameter portion 18B is continuously formed on the axial center side of the intermediate cylinder 18 of the enlarged diameter portion 18A, and is in pressure contact with the thin wall portion 50B of the seal rubber 50. Further, the thick inner portion 50A of the seal rubber 50 is in pressure contact with the outer periphery of the recess 30 formed in the axially intermediate portion of the intermediate cylinder 18.

As shown in FIGS. 1 and 2, a main body rubber 20 as an elastic body is stretched between the inner cylinder 12 and the intermediate cylinder 18. Since the metal fitting 24 is disposed below the axially intermediate part of the inner cylinder 12 (lower part in Figure 1), the main body rubber 20 in this part protrudes downward in Figure 1, and in the vertical direction in Figure 1. It serves as a stopper when the inner cylinder 12 moves.

Further, between the main body rubber 20 and the intermediate cylinder 18 (on the upper side of FIG. 1), a hollow part 22 is provided as a gap part.
The elasticity of the main body rubber 20 is adjusted.

As shown in FIG. 1, a liquid chamber 26 is provided on the opposite side of the hollowed out portion 22 (lower side in FIG. 1) via the inner cylinder 12, and contains water and water.
A liquid such as oil is sealed.

The liquid chamber 26 is formed by filling water, oil, etc. into a notch 2OA provided from the outer circumference of the main body rubber 20 toward the inner cylinder 12.

Inside this liquid chamber 26 is a main body rubber 2 that forms this liquid chamber 26.
A partition plate 28 having a substantially hat-shaped cross section is disposed from the outside of the housing. A peripheral edge portion 28A of the partition plate 28 is held between the intermediate tube 18 and the diaphragm portion 16A. Further, the U-shaped intermediate portion 28B enters into the liquid chamber 26 through a notch 18D formed in the recess 30 of the intermediate cylinder 18, and divides the liquid chamber 26 into small liquid chambers 26A and 26B. The recess 30 near the notch 18D restricts movement of the partition plate 28 in the direction of the inner cylinder 12 (upward in FIG. 1).

After assembly, the outer periphery of the recess 30 of the intermediate cylinder 18 forms a restriction passage 32 between the inner periphery of the thin film rubber 16 and the seal rubber 50, as shown in FIG.

As shown in FIG. 2, this restriction passage 32 has one end 32A in the longitudinal direction connected to the small liquid chamber 20 through the notch 2OA of the main body rubber 20.
6A, the other end 32B is connected to the small liquid chamber 26B by the end 28D of the partition plate 28 coming into contact with the end 18F of the intermediate cylinder 18.
It is connected to.

A diaphragm 116A, which is a part of the thin film rubber 16 and approaches the part corresponding to the partition plate 28 away from the outer cylinder 14 toward the partition plate 28, faces the partition plate 28 and forms the outer wall of the small liquid chamber 26B. The small liquid chamber 26B can be expanded or contracted.

As shown in FIG. 3, a rectangular notch 44 is formed in the outer cylinder 14 at a portion corresponding to the diaphragm portion 16A of the thin film rubber 16, and the long side is in the circumferential direction and the short side is in the axial direction. The surface of the diaphragm portion 16A on the side opposite to the small liquid chamber 26B faces the outside air.

When manufacturing the vibration isolator 10 according to this embodiment, first, the main body rubber 20 is vulcanized and bonded between the inner cylinder 12 and the intermediate cylinder 18. This main body rubber 20 is provided with a notch 2OA for forming a liquid chamber 26 corresponding to the notch 18D of the intermediate cylinder 18.

On the other hand, a thin film rubber 16 and a seal rubber 50 are vulcanized and bonded to the inner peripheral surface of the outer cylinder 14. In this case, a concave diaphragm portion 16A is formed in the thin film rubber 16, and this diaphragm portion 16A corresponds to the notch 44 of the outer cylinder 14. Therefore, this diaphragm portion 16A is not vulcanized and bonded.

When the inner cylinder 12 and the intermediate cylinder 18, which are integrated by vulcanizing and adhering the main body rubber 20, are inserted into the outer cylinder 14 in the liquid, the liquid chamber 26 and the restriction passage 32 are filled with liquid. That will happen. In this state, a drawing process is performed to reduce the outer diameter of the outer cylinder 14.

Next, the axial end portion 14A of the outer tube 14 is brought into contact with the end surface of the intermediate tube 18 and the rubber 19, and is bent and caulked to complete the vibration isolator 10.

Next, the operation of the first embodiment will be explained.

Vibrations generated in the engine are transmitted to the inner cylinder 12 via a bracket (not shown), but the vibrations are absorbed by the internal friction of the main body rubber 20. In addition, vibrations that are not absorbed by the main body rubber 20 are transmitted to the liquid chamber 26 via the main body rubber 20, so as the liquid in the liquid chamber mutually moves through the restriction passage 32, the vibration is absorbed by the passage resistance during movement. be done.

In the vibration isolator 10 according to the present invention, the restriction passage 32 is sealed with a seal rubber 50.

Moreover, since the reduced diameter portion 18B is formed in the intermediate cylinder 18, when the outer cylinder 14 is squeezed, the thin film portion 50B
is sealed at a constant pressure, and a constant sealing pressure can be ensured at the thin wall portion 50B.

Therefore, there is no need to prepare a separate ○ ring etc. for the restriction passage 3.
The sealing performance of No. 2 does not deteriorate. Therefore, intermediate cylinder 1
Since there is no need to perform a cutting process to form a ring groove for accommodating the ○ ring in 8, the product cost can be suppressed and the production efficiency of the product can be increased.

In addition, when the engine vibrates in the axial direction of the vibration isolator 10 due to driving on a rough road, etc., the vibration is transmitted to the intermediate cylinder 1 through the inner cylinder 12 and the main body rubber 20.
8 in the axial direction. Even if it vibrates in the horizontal direction in the figure, the enlarged diameter portion 18A of the intermediate cylinder 18 is in direct contact with the inner circumferential surface of the outer cylinder 14, so the frictional resistance is large, and the end 1 of the outer cylinder 14
4A is caulked to the intermediate cylinder 18, so that the intermediate cylinder 18 and the outer cylinder 14 will not shift in the axial direction. Thereby, the durability of the vibration isolator 10 can be improved.

Although the thin film rubber 16 and the seal comb 50 are formed separately in this embodiment, they may be formed integrally.

[Second Embodiment] FIG. 5 shows a second embodiment of the vibration isolator 10 according to the present invention.

In this embodiment, the seal rubber 50 is vulcanized and bonded not to the outer cylinder 14 (see FIG. 4) but to the reduced diameter portion 18B and the recess 30 of the intermediate cylinder 18. The outer diameter of the seal rubber 50 is formed to be slightly larger than the outer diameter of the enlarged diameter portion 18A of the intermediate cylinder 18, so that it can come into pressure contact with the inner circumferential surface of the outer cylinder 14. Further, on the outer peripheral surface of the seal rubber 50, there are a plurality of (three in the embodiment) ring-shaped glue 60 that protrude in the radial direction and extend along the outer periphery of the intermediate cylinder 18 at intervals in the axial direction of the intermediate cylinder 18. It is formed.

Therefore, by providing the ridge 60, the seal rubber 50
Since the outer cylinder 14 and the outer cylinder 14 are more strongly pressed against each other, the sealing performance of the restriction passage 32 is improved.

Furthermore, a ring-shaped glue ridge 60 is provided protruding from the rubber 19 vulcanized and bonded to the inner circumferential surface of the enlarged diameter portion 18A of the intermediate cylinder 18. Therefore, when the end 14A (see FIG. 4) of the outer cylinder 14 is caulked, the end 14A and the rubber 19 are pressed together more strongly, and the sealing performance of the rubber 19 is also improved.

[Third Embodiment] FIGS. 6 to 9 show a third embodiment of the vibration isolating device 10 according to the present invention.
An example is shown.

As shown in FIG. 8, a seal rubber 50 is vulcanized and bonded to the axially intermediate portion of the intermediate cylinder 18. This seal rubber 50
A ring-shaped glue joint 60 is provided in a portion corresponding to the reduced diameter portion 18B of the intermediate cylinder 18 so as to protrude in the radial direction.

Further, the axially intermediate portion of the seal rubber 50 is a diaphragm portion 74, and the diaphragm portion 74 is connected to the notch 18 of the intermediate cylinder 18.
It protrudes from D into the recessed portion 22 and forms the outer wall of the sub-liquid chamber 76.

As shown in FIGS. 7 and 9, in this embodiment, an orifice unit 70 made of an insulating material such as synthetic resin or ceramics is disposed in the recess 30 of the intermediate cylinder 18.

As shown in FIG. 9, the orifice unit 70 is composed of a pair of semicircular orifice unit pieces 70A and 70B. Both ends of OA and 70B are brought into contact to form a ring shape. As a result, the 7th
As shown in the figure, a sub-liquid chamber 76 is formed above the inner cylinder 12, and a main liquid chamber 72 is formed below. Sub-liquid chamber 76
The main liquid chamber 72 is filled with electrorheological fluid. The electrorheological fluid may include, for example, 40% to 60% by weight of silicic acid, 30% to 50% by weight of a low-boiling organic phase, and 50% by weight of a low-boiling organic phase.
A mixture of from 10% to 10% by weight of water and 5% by weight of a dispersion medium can be used, for example indodecane. The electrorheological fluid has the viscosity of a normal hydraulic fluid when no electricity is applied, and when electricity is applied, the viscosity changes depending on the electric field strength and the viscosity increases.

Said orifice unit piece? A groove is formed in the OA and 70B to form a restriction passage 78.

A number of 80.82 electrodes are attached to the restriction passage 78 facing each other, and these are connected to a control device (not shown) via conductive wires (not shown).

In this embodiment, the electrode plate 80 is set as a positive pole, and the electrode plate 82 is set as a negative pole.

As shown in FIGS. 7 and 9, the orifice unit piece 7
Openings 84A and 84B are formed in 0A and 70B, respectively (FIG. 9 shows only the opening 84B formed below the orifice unit pieces 70A and 70B), and the main liquid chamber 72 and The sub-liquid chamber 76 is the opening 84.
A and 84B communicate with each other, allowing electrorheological fluid to flow back and forth between the main liquid chamber 72 and the sub-liquid chamber 76.

In this embodiment, in the case of minute vibrations of extremely low frequency such as during engine shaking, the electrode plates 80 and 82 are energized through conductive wires.

Then, the viscosity of the electrorheological fluid within the restriction passage 78 increases, preventing the electrorheological fluid from moving within the restriction passage 78, thereby making it possible to absorb extremely low frequency vibrations.

In addition, in the first to third embodiments, the end 14A of the outer cylinder 14 is caulked to the intermediate cylinder 8, but the outer cylinder 1 is not necessarily caulked to the intermediate cylinder 8.
There is no need to caulk the end portion 14A of 4 to the intermediate cylinder 18.

〔Effect of the invention〕

As explained above, the present invention has the excellent effect of being able to improve the sealing performance of the restriction passage without arranging a circle ring or the like on the intermediate cylinder, and suppressing an increase in product costs. .

Further, since the intermediate cylinder and the outer cylinder are brought into direct contact with each other, it is possible to prevent the intermediate cylinder and the outer cylinder from shifting, thereby providing an excellent effect of improving the durability of the product.

[Brief explanation of drawings]

1 to 4 show a first embodiment of the vibration isolating device according to the present invention, FIG. 1 is a sectional view taken along the line II in FIG. 2, and FIG. 3 is an exploded perspective view, FIG. 4 is a partially enlarged view of FIG. 1, and FIG. 5 is an intermediate view corresponding to FIG. 4 showing a second embodiment of the vibration isolator according to the present invention. A partially enlarged sectional view of the cylinder, FIGS. 6 to 9 show a third embodiment of the vibration isolator according to the present invention, FIG. 6 is a sectional view taken along the line VI-VI in FIG. Fig. 6 is a sectional view taken along the line ■-■, Fig. 8 is a sectional view corresponding to Fig. 6 of the intermediate cylinder before insertion into the outer cylinder, Fig. 9 is an exploded perspective view, and Fig. 10 is a conventional vibration isolator. FIG. 11 is a partial sectional view of the intermediate cylinder corresponding to FIG. 5 showing another conventional vibration isolator. DESCRIPTION OF SYMBOLS 10... Vibration isolator, 12... Inner cylinder, 14... Outer cylinder, 18... Intermediate cylinder, 18A... Expanded diameter part, 18B... Reduced diameter part, 20... Main body rubber (Elastic body), 26...Liquid chamber, 32...Restriction passage, 50...Seal rubber (sealing material).

Claims (1)

[Claims] (1) An inner cylinder supported by one of the vibration generating part and the vibration receiving part, and an inner cylinder arranged on the outside of the inner cylinder so that the axis faces the axial direction of the inner cylinder. an outer cylinder supported by the other one, and an outer cylinder disposed between the inner cylinder and the outer cylinder, with an enlarged diameter part formed at both ends in the axial direction and a reduced diameter part in the middle part, and an outer periphery of the enlarged diameter part. an intermediate cylinder in direct contact with the inner periphery of the outer cylinder; a sealing material disposed between the intermediate cylinder and the outer cylinder and sandwiched between the outer periphery of the reduced diameter portion of the intermediate cylinder and the inner periphery of the outer cylinder; It is characterized by providing an elastic body stretched between the inner cylinder and the intermediate cylinder, a plurality of liquid chambers formed inside the elastic body, and a restriction passage communicating the plurality of liquid chambers. Anti-vibration device.