JPH09264369A - Viscous fluid sealed vibration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease the dynamic spring constant in the high-frequency range without deteriorating damping properties in the low-frequency range by attaching a stirring plate in a state where an elastic member provided on one side in the axial direction is previously compressed in the axial direction of an inner fitting by the specified amount. SOLUTION: An elastic member 60 is a spring washer-like spring body, and a stirring plate 50 is pressed to an inner fitting 12 with specified energizing force by a shoulder bolt 70. When force exceeding energizing force, to be generated by the flowing resistance of viscous fluid is applied to the stirring plate 50 in the direction separated from the inner fitting end 12, the stirring plate 50 is separated from the inner fitting end 12, next, when the force to be applied to the stirring plate 50 is reversed after the vibrating direction is reversed, the flowing resistance is eliminated, and the stirring plate 50 is again pressed and returned to the inner fitting end 12 by energizing force of the elastic member. At this time, damping force by the flowing resistance is not temporarily generated, and the dynamic spring constant in high-frequency can be decreased. Accordingly, transmitting force of high-frequency vibration can be decreased without decreasing damping force of low-frequency vibration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration support device mounted between a vibrating body and a support member in vehicles, industrial machines and the like.

[0002]

2. Description of the Related Art As a conventional viscous fluid-filled type vibration damping device,
The stirring plate provided in the internal liquid chamber often has a structure in which it is fixed to the end of the inner metal fitting. However, in the case of this structure, it is known that, particularly in the high frequency vibration band, the dynamic spring constant increases as the viscous resistance increases, and the insulation of vibration becomes disadvantageous. In order to solve this phenomenon, as shown in FIG. 5, a stirring plate is attached to the inner metal fitting via an elastic member, or as shown in FIG. 6, the stirring plate is attached to the inner metal fitting so as to be floatable by a predetermined amount and elastically. Is proposed. (For example, JP-A-59-73650 and JP-A-61-52743)

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention 2
In each of the examples, the effect of reducing the dynamic spring constant at the high frequency can be realized, but on the other hand, the originally intended damping characteristic in the low frequency range is that the inner metal fitting and the stirring plate are relatively Inevitably, it has a drawback that it decreases with the loss of viscous resistance due to the fact that it is movable. SUMMARY OF THE INVENTION It is an object of the present invention to provide a viscous fluid filled type vibration damping device which does not impair the damping characteristics in the low frequency range and reduces the dynamic spring constant in the high frequency range.

[0004]

In order to achieve the above object, a viscous fluid-filled type vibration damping device proposed by the present invention is provided in a liquid chamber and is provided with a flow resistance of the viscous fluid due to vertical vibration of an inner metal fitting. If a stir plate that generates damping force is attached to the end of the inner metal fitting with a predetermined precompression by an elastic member, and if flow resistance exceeding the predetermined precompression load occurs, the stir plate will It is characterized in that it is configured to be in a floating state with respect to the metal fitting.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a viscous-fluid-filled type vibration damping device of the present invention includes an inner metal fitting 10 provided with a bolt for assembling a vibrating body (not shown), and a bottom provided concentrically on the outer periphery thereof. An outer metal fitting 20 having a lid 22 and an assembling hole 21 for a support member (not shown), and an inner metal fitting 10 and an outer metal fitting 20 are bonded to each other to elastically support a vibrating body (not shown). The rubber elastic body 30, the viscous fluid 41 enclosed in the liquid chamber 40 surrounded by the rubber elastic body 30, and the liquid chamber side end 12 of the inner metal fitting 10 are attached via the elastic member 60 by the stepped mounting bolt 70. Stirring plate 50
And is constituted by. The plate-shaped plate 80 is a stopper plate that is integrally attached to the inner metal member 10 and that prevents the rubber elastic body 30 from excessively deforming,
Reference numeral 91 is a rivet that seals the viscous fluid 41.

The elastic member 60 shown here is a spring washer-shaped spring body, and an initial height of 7 mm is compressed by 2.5 mm by setting the length of the stepped bolt 70 to a predetermined length. It is fixed in the state where it was made. Since the elastic body 60 has a compression spring constant of 50 ^N / mm, the stirring plate 50 is in a state of being pressed against the inner metal fitting end 12 by the urging force of 250 ^N.

Therefore, the stirring plate 50 is moved by the flow resistance of the viscous fluid in the direction away from the end 12 of the inner metal fitting.
When a force exceeding 50 ^N is applied, the stirring plate 50 is separated from the inner metal fitting end portion 12, and from this state, when the direction of vibration is reversed and the force applied to the stirring plate 50 is reversed, viscous fluid is generated. Stirrer plate 5 with no flow resistance
0 is pushed back to the inner metal fitting end 12 by the urging force of the elastic member. At this time, the damping force due to the flow resistance of the viscous fluid is temporarily not generated, and as a result, the dynamic spring constant at high frequencies can be reduced.

Generally, the resistance of the stirring plate in the viscous fluid is proportional to the speed thereof, so in the viscous fluid-filled type vibration damping device of the present invention, the spring characteristic of the elastic member to be used and the amount of preliminary compression are appropriately selected. This makes it possible to obtain the conventional damping characteristics in the low frequency vibration band and, at the same time, to prevent the transmission of vibration in the high frequency vibration band.

Next, another embodiment of the present invention will be described with reference to FIG. 2. This drawing shows an embodiment in which the configurations of the elastic member and the stirring plate in the embodiment of FIG. 1 are changed. Cross-sections are shown and the same numbers are used for the other parts. That is, the elastic members 61 and 62 in this figure are made of rubber materials that are vulcanized and adhered to the upper and lower surfaces of the stirring plate 50, respectively, and the stirring plate 50 is in a state in which the elastic members 61 and 62 are pre-compressed by a predetermined size by stepped bolts. And, it is assembled to the end of the inner metal fitting. In this case, the stirring plate 50 is provided with a flow hole 51 for adjusting the flow resistance of the stirring plate 50.

More specifically, as shown in FIG. 3A, an elastic member 6 made of a rubber material that is vulcanized and bonded to the stirring plate 50.
1, 62 are molded with a height dimension of l _{0 in} the figure, and are compressed to l ₁ by a stepped portion provided on the assembly bolt when assembled to the inner metal fitting liquid chamber side end portion. There is. In this case, the difference from the above embodiment is that when the compression spring constants of the elastic members 61 and 62 are K ₁ and K ₂ , as shown in FIG. In this relationship, the combined spring constant K is the elastic member 6
Within the range of the compression amount a + b of _{1 and} 62, K = K ₁ + K ₂ , and when exceeding this range, each has a separate spring constant, and K = K ₁ or K = K ₂ .

That is, in this case, even if the vibrating resistance of the inner metal fitting increases in the axial direction and the displacement speed increases, the elastic members 61 and 62 are proportional to the displacement within the range of the preliminary compression amount. Although a reaction force is generated due to this, when the range is exceeded, the increase in reaction force is suppressed low, and one of the elastic members floats from the inner metal fitting 10 and returns in the opposite vibration direction. At this time, the resistance force of the viscous fluid ceases to act, and the effect of reducing the transmission force with respect to high-frequency and large-displacement vibrations can be more remarkably obtained. In addition, the elastic member 6
By forming 1 and 62 with a rubber-like elastic body,
It is possible to prevent the generation of hammering noise and abnormal noise on the contact surface between the inner metal fitting end 12 and the bolt 70.

Next, FIG. 4 shows an essential part of an embodiment showing another embodiment of the present invention. This figure shows that the inner metal fitting end side of the stirring plate is a vulcanized and bonded rubber elastic body 6 as in the above embodiment.
1 and the opposing surface uses a metallic disc spring 63, and a cushioning member 65 made of a rubber-like elastic body is arranged between the elastic member 63 and the stirring plate 50.

The buffer member 65 can prevent abnormal noise when the elastic member 63 and the stirring plate 50 come into contact with each other due to vibration.

【The invention's effect】

As described above, in the present invention, in low-frequency vibration with a slow vibration speed, vibration is transmitted in high-frequency vibration with a high vibration speed without reducing the damping force of the viscous fluid. It is possible to reduce the force and prevent abnormal noise generated from each movable part due to vibration.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a viscous fluid-filled type vibration damping device of the present invention.

FIG. 2 is another embodiment of the viscous fluid-filled type vibration damping device of the present invention.

FIG. 3 is an explanatory diagram showing a main part of the embodiment of FIG.

FIG. 4 is a cross-sectional view of essential parts of a viscous fluid-filled type vibration damping device according to still another embodiment of the present invention.

FIG. 5 is a sectional view showing a conventional technique.

FIG. 6 is a sectional view showing a conventional technique.

[Explanation of symbols]

 10 Inner Metal Fitting 11 Vibrating Body Mounting Bolt 12 Inner Metal Fitting End Surface 20 Outer Metal Fitting 21 Outer Metal Fitting Mounting Part 30 Rubber Elastic Body 40 Liquid Chamber 41 Viscous Fluid 50 Stirring Plate 60, 61, 62, 63 Elastic Member 65 Buffer Member 70 Stirring Plate Mounting Bolt 90 Lid body

Claims (3)

[Claims] 1. A bottomed tubular outer metal member having mounting means for attaching to a vibrating body, an outer metal member concentrically arranged on an outer peripheral portion of the inner metal member, and for mounting to a support body, and the outer side. A liquid chamber is formed on the bottom side of the outer metal member by a cylindrical rubber elastic body that connects the metal members in a liquid-tight manner and supports the vibrating body, and a liquid chamber is formed in the liquid metal chamber at the end of the inner metal member. In a viscous fluid-filled type vibration damping device in which a disc-shaped stirring plate for partitioning in the axial direction is attached and a viscous fluid is filled in the liquid chamber, the stirring plate is provided at least on one side in the axial direction. A viscous fluid-filled type vibration damping device, wherein the elastic member is attached in a state of being pre-compressed by a predetermined amount in the axial direction of the inner metal member. 2. The viscous fluid-filled type vibration damping device according to claim 1, wherein the elastic member is a spring body made of a rubber-like elastic material. 3. A cushioning member made of a rubber-like elastic body is provided between the agitating plate or the end of the inner metal fitting with which the elastic member abuts.
The viscous fluid-filled vibration damping device described.