JPS61197836A - Vibration preventing device - Google Patents

Abstract

PURPOSE:To lower dynamic spring constant in vibration of large amplitude and improve durability of elastic separating member by forming a mounting portion of the elastic separating member separating a liquid chamber in bent form and avoiding stress concentration against large load. CONSTITUTION:A liquid chamber 26 is separated into two liquid chambers 26A and 26B by a diaphragms 16 and an elastic separating member 32 fit to the center of the diaphragm 16. And both the liquid chambers 26A and 26B are communicated by an orifice 40 provided on the diaphragm 16. And the elastic separating member 32 is mounted by a bent form bent portion 33, and its contact area is enlarged.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vibration isolating device that is interposed between a vibration generating section and a vibration receiving section and absorbs and damps vibrations.

[Background Art and Issues to be Solved] A vibration isolating device is used in which a liquid is injected into a hollow body made of an elastic material and the liquid is divided into a plurality of small liquid chambers via restriction passages. In this vibration isolator, vibrations applied to one liquid chamber cause the liquid to move between it and the other liquid chamber, and the vibrations are absorbed by the resistance generated in the control road.

However, with this type of vibration isolator, the restriction passage becomes clogged during high frequency vibrations, resulting in an increase in dynamic magnification, and the vibration absorption characteristics at high frequencies are low. In some cases, this may cause the ride comfort of the vehicle to deteriorate.

For this reason, conventional vibration isolators that use minute vibrations on the partition walls that partition the liquid chamber allow the volume of the liquid chamber to be changed by the vibration of the diaphragm even after the restriction passage becomes clogged during high-frequency vibration, thereby reducing the dynamic magnification. It is designed to allow

However, even in a vibration isolating device having such a diaphragm, there is a problem that the dynamic magnification increases during large amplitude vibrations, and the vibration absorption characteristics deteriorate.

For this reason, the applicant has already proposed a vibration isolator that does not increase dynamic magnification at low frequencies during large amplitude vibrations (
(Patent Application No. 187365/1982).

Taking these facts into consideration, the present invention has been developed to prevent the dynamic magnification from increasing at low frequencies during large-amplitude vibrations even with a vibration isolator having a restricted passage, and to prevent the installation of elastic partition members used therein. The purpose is to obtain a reliable vibration isolator.

[Summary and operation of the invention] In the vibration isolating device according to the present invention, the hollow part of the vibration absorbing body, which is interposed between the vibration generating part and the vibration receiving part and is mainly made of a hollow body of an elastic material, is used as a liquid chamber, The liquid chamber is divided into a plurality of small liquid chambers by an elastic partition member, and the mounting area of the elastic partition member is bent to increase the mounting area.

Therefore, in the present invention, the elastic partition member used to partition the liquid chambers suppresses the volume change when the internal pressure of one liquid chamber increases and reduces the dynamic magnification even when the restriction passage becomes clogged. The elastic partition member is securely attached by the bent attachment portion to cope with a large load and avoid stress concentration.

[Embodiment of the Invention] FIG. 1 shows a vibration isolating device according to a first embodiment of the present invention, which is an embodiment applied to an engine mount of an automobile.

A port 12 is fixed to the lower center of the base plate 10, and is adapted to be fixed to the body of an automobile (not shown). A flange 14 is integrally formed at the upper end of the cylindrical portion 10A extending from the periphery of the base plate 10, and a partition plate 16 is fixed thereto. The periphery of a diaphragm 18 is clamped and fixed between the partition plate 16 and the seven langes 14, and an air chamber is formed between the diaphragm 18 and the base plate 10.

Further, the lower end portion of a cylindrical rubber 20 constituting the vibration absorbing body is vulcanized and bonded to the upper part of the partition plate 16. This rubber 2
A top plate 22 is vulcanized and bonded to the upper end of the engine 0, and bolts 24 protruding from the top plate 22 are used to secure an engine (not shown).

A hollow portion formed by the top plate 22, the rubber 20, and the diaphragm 18 is filled with liquid to form a liquid chamber 26.

The partition plate 16 has a circular hole 28 in the center as shown in FIG.
is provided, and the upper end of the sleeve 30 is integrally connected to the periphery of the circular hole 28.

The outer circumferential portion of the elastic partition member 32 is vulcanized and bonded to the inner circumferential portion of the sleeve 30 . The elastic partition member 32 has a disk shape and is preferably made of an elastic material such as rubber that can be bent by a certain amount.

Here, a part of the inner peripheral surface of the sleeve 30 is a bent part 33 that protrudes in a ring shape in the direction of reducing the inner diameter. Therefore, the elastic partition member 32 whose outer peripheral surface is attached to the bent portion 33 has a large contact area with the bent portion 33, and has high strength. It is preferable that the thickness of the elastic partition member 32 gradually decreases as it moves away from the bent portion 33 and reaches the center.

In this way, the partition plate 16 is connected to the liquid chamber 2 together with the elastic partition member 32.
6 is divided into an upper liquid chamber 26A and a lower liquid chamber 26B.

An abutment plate 34 is fixed to the lower part of the partition plate 16. A cylindrical sleeve 36 integrally projects from the inner circumference of the contact plate 34 and is fixed to the outer circumference of the sleeve 30.

Further, a rectangular groove 38 is formed at the connection portion between the abutment plate 34 and the sleeve 36, extending over approximately two-thirds of the circumference of the sleeve 36. For this reason, the bulkhead plate 16. An orifice 40, which is a restricted passage, is provided between the sleeve 30, the abutment plate 34, and the sleeve 36, and this orifice 40 has one end formed in a circular hole 42 formed in the partition plate 16, and the other end formed in the groove 38. It communicates with the upper liquid chamber 26A and the lower liquid chamber 26B through circular holes 44 formed at the bottom.

Next, the operation of this embodiment will be explained.

The base plate 10 is fixed to the body of an automobile (not shown) via the top plate 12, and the engine is mounted on the top plate 22 and fixed with bolts 24 to complete the assembly.

Engine vibrations are absorbed by internal friction generated within the rubber 20, but especially when the vibration frequency is low, the orifice 4
Vibration is absorbed by the resistance of the liquid flowing through the upper liquid chamber 26A, lower liquid chamber 26B, etc.

Furthermore, when the frequency of vibration is large, the orifice 40 becomes clogged, but the elastic partition member 32 bends by a predetermined amount and moves toward the upper liquid chamber 26A or the lower liquid chamber 26B to absorb the pressure increase. Vibration can be absorbed by

Furthermore, since the elastic partition member 32 is used in this embodiment, the bulk elasticity of the liquid chamber 26A after the orifice 40 becomes clogged (when the internal pressure of the upper liquid chamber 26A is increased by a unit internal pressure) The reciprocal of the changed volume of the upper liquid chamber 26A) can be suppressed to a low level, and even with large amplitude vibrations, the dynamic magnification can be kept at 2 or less.

Even during such deformation of the elastic partition member 32, since the elastic partition member 32 is vulcanized and bonded to the sleeve 30 over a wide area via the bent portion 33, a large stress is concentrated on the attachment portion to the sleeve 30. This can improve durability.

FIG. 3 shows a vibration isolator according to a second embodiment of the present invention.

In this embodiment, the inner circumferential end of the partition plate 16 is once bent in the axial direction, and then bent in the axial direction of the circular hole 28, and this bent part has a cross-sectional shape that is a concave half-shaped part facing downward. A circular bent portion 46 is formed.

On the other hand, the upper end portion of the sleeve 45 that comes into contact with the inner periphery of the sleeve 36 corresponds to this semicircular upper bent portion 46 and forms a semicircular bent portion 48 that is concave upward.

Further, the elastic partition member 32 has an outer circumferential portion thicker than a central portion, and the outer circumferential portion has a circular bulge portion 32A in cross section.

Therefore, this elastic partition member 32 has a semicircular bent portion 46.4.
8, the elastic partition member 32 is reliably attached to the partition plate 16 and the sleeve 45, and the elastic partition member 32 partially closes the orifice 40.

Therefore, in this embodiment as well, the elastic partition member 32 is firmly attached as in the previous embodiment, and can have the same effect.

Next, FIG. 4 shows a vibration isolating device according to a third embodiment of the present invention.

In this embodiment, unlike the previous embodiments, a sleeve 30 is projected upward from the partition plate 16, and the upper end of the sleeve 30 is bent in the axial direction, and the tip is bent at a right angle to form an upright bent portion. It is 51.

Further, the outer periphery of the abutment plate 34 is fixed to the partition plate 16 to form an orifice 40 between the abutment plate 34 and the sleeve 30, but the abutment plate 34 is closed at its axial center by a lid member 53. A plurality of small holes 55 are formed through the lid member 53.

The vicinity of the outer periphery of the elastic partition member 32 is vulcanized and bonded to the bent portion 51, and the center portion of the elastic partition member 32 is bonded to the lid member 5.
3, and when deformed in the direction of the lower liquid chamber 26B, this lid material 5
3, the amount of movement is limited.

Therefore, in this embodiment, the amount of downward movement of the elastic partition member 32 is limited by the lid member 53, and when moving upward, it is bonded to the bent portion 51 over a wide area. The larger installation has strength.

A portion of the outer periphery of the elastic partition member 32 enters between the inside of the sleeve 30 and the outer periphery of the abutting plate 34 to close the space between the abutting plate 34 and the sleeve 30.

Next, FIG. 5 shows a fourth embodiment of the present invention.

In this embodiment, the bent portion 51 of the third embodiment is changed to a bent portion 57 whose cross-sectional shape is reversed to a semicircular shape, and the elastic partition member 32 is fixed more firmly than in the previous embodiment.

Therefore, this embodiment is suitable for a case where the inner circumferential portion of the contact plate 34 does not have the lid member 53 as in the previous embodiment, and the elastic partition member 32 is configured to directly face the lower liquid chamber 26B.

[Effects of the Invention] As explained above, in the vibration isolating device according to the present invention, the divided liquid chambers are communicated with each other via the restriction passage, and elastic members are provided in the partitions of the plurality of liquid chambers, so that large amplitude vibrations are prevented. It has the excellent effect of being able to lower the dynamic spring constant at the same time and making the attachment of the elastic member stronger.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of the vibration isolator according to the present invention, FIG. 2 is an exploded perspective view showing parts for forming the orifice shown in FIG. 1 (partition member 32 is omitted), Third
FIG. 4 is a sectional view showing a second embodiment of the invention, FIG. 4 is a sectional view showing a third embodiment of the invention, and FIG. 5 is a sectional view showing a fourth embodiment of the invention. 16... Partition plate, 20... Rubber, 26... e-liquid chamber, 26A-- upper liquid chamber, 26B... lower liquid chamber. 28... circular hole. 30... Sleeve, 32.ψψ elastic partition member. 32A fist - bulging part, 33.51.57 fist - bent part, 401 - orifice, 46.48 - φ - semicircular bent part.

Claims (3)

[Claims] (1) A hollow chamber that is interposed between the vibration generating section and the vibration receiving section and mainly consists of a hollow body made of an elastic material and mainly acts as a vibration absorber is used as a liquid chamber, and this liquid chamber is divided into a plurality of small liquid chambers using elastic partition members. A vibration isolator characterized in that the mounting area of the elastic partition member is curved to increase the mounting area. (2) The vibration isolator according to claim 1, wherein the mounting portion is an inner peripheral portion of a through hole formed in a partition plate that partitions a liquid chamber. (3) The vibration isolator according to claim 1, wherein the mounting portion is a bent plate inserted into the elastic partition member.