JPH08177964A - Vibration proof device - Google Patents

Abstract

PURPOSE: To facilitate manufacture by simple construction and reduce the manufacturing cost by adjusting fluid resistance of liquid in a slender restricted passage so as to obtain damping effect due to liquid column resonance against vibration of various frequencies input from a vibration generating part. CONSTITUTION: Vibration generated in an engine is transmitted to a liquid chamber 13 through a vibration absorbing main body 10, electroviscous fluid in the liquid chamber 13 is moved through an orifice 18, and the vibration is absorbed by the passing resistance. An electrode plate 21 and the outside wall 24 of the lower end part of an outer cylinder 9 are made to carry a current through lead wires 22, 22A, viscosity of electroviscous fluid in the orifice 18 is adjusted, and because the orifice 18 is formed along a circular-arc-like protruded part 6 into a slender shape of long axial measure, even if engine vibration is generated extending over a wide range of frequency, various liquid column resonance vibration absorbing effects corresponding to these are obtained. In this way, manufacture is facilitated by simple construction and the manufacturing cost is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device interposed between a vibration generating portion and a vibration receiving portion, and more particularly to a vibration damping device which is filled with liquid and absorbs vibration by its flow resistance.

[0002]

2. Description of the Related Art As a vibration isolator used for automobile engine mounts, cab mounts, body mounts, etc., there is a normal liquid-filled vibration isolator having a liquid chamber partially formed of an elastic body inside. . In this device, the liquid chamber is divided into a plurality of small liquid chambers, and these small liquid chambers are communicated with each other by an orifice (that is, a restriction passage). For this reason,
When vibration occurs, the liquid in one small liquid chamber moves toward the other small liquid chamber through the orifice, and the vibration is absorbed and damped by the flow resistance of the liquid generated at that time.

Further, there has been proposed a device that uses the liquid as an electrorheological fluid and applies an electric field to change the viscosity of the liquid according to the strength of the liquid to prevent vibration (Japanese Patent Laid-Open No. 60-10482).
No. 8, JP-A-61-74930).

[0004]

However, in the former ordinary liquid or liquid-filled type vibration damping device, a plurality of orifices having different sizes are provided in order to cope with vibrations of different frequencies generated in an automobile or the like. , It must be a complicated structure to open and close each of these with valves.

Further, in the vibration isolator for applying an electric field to the electrorheological fluid to change the viscosity of the liquid, the length of the orifice is conventionally set to be short so that sufficient damping cannot be achieved. is there. Moreover, in such a device,
Since the electrodes for applying an electric field to the liquid are installed inside the device on both the positive electrode side and the negative electrode side, the internal structure of the device becomes complicated and the number of parts increases and the manufacturing cost generally increases. There has been a problem that when both electrode plates are arranged in parallel in the orifice which is a narrow passage at a constant interval, higher assembly precision is required and it is difficult to manufacture.

In view of the above circumstances, an object of the present invention is to provide a liquid-filled type vibration damping device which is easy to manufacture with a simple structure and which can be manufactured at a reduced cost.

[0007]

In order to achieve the above object, in the vibration isolator of the present invention, as described in claim 1, the vibration isolator is connected to either the vibration generator or the vibration receiver. A first member, a second member connected to the other of the vibration generating unit and the vibration receiving unit, the first member, and the second member
And an elastic body that is elastically deformed when vibration occurs, and a expandable and contractible liquid chamber having the elastic body as a part of a partition wall, and a plurality of small liquid chambers that partition the liquid chamber. In a partition member for partitioning at least a pair of small liquid chambers in the plurality of small liquid chambers, the vibration isolation device having: An elongated limiting passage communicating between the small liquid chambers, an electrorheological fluid filled in the plurality of small liquid chambers and the elongated limiting passage, and an inner wall surface of the elongated limiting passage are provided. And an electrode for changing the viscosity of the electrorheological fluid in the restriction passage by energizing the outer wall of the first member as a counter electrode.

[0008]

According to the present invention, a liquid chamber, a part of which is formed of an elastic body, is provided between the vibration generating part and the vibration receiving part, and the electro-viscous liquid is filled in the liquid chamber. Of the small liquid chambers, and at least a pair of the small liquid chambers of the small liquid chambers are partitioned by a partition member, and the liquid chambers are communicated with each other by an elongated restriction passage. Moreover, by installing an electrode on the inner wall surface of the elongated restriction passage along the stroke of the restriction passage and energizing it, the viscosity of the electrorheological liquid in the restriction passage is changed and the flow resistance thereof is adjusted.
That is, the damping effect due to the liquid column resonance can be obtained by adjusting the flow resistance of the liquid inside the elongated limiting passage with respect to the vibrations of various frequencies input from the vibration generating unit.

Further, in the present invention, one side wall (outer wall) of the limiting passage is the first member made of metal, and this outer wall is used as one electrode, and the other side of the inside of the limiting passage is used. The electrode plate installed on the wall surface is used as the other electrode to conduct electricity between both electrodes to apply an electric field to the electrorheological fluid. For this reason, it is not necessary to have a complicated structure in which both electrode plates are installed while maintaining a constant interval in a narrow restriction passage, and it is sufficient to install only the other electrode on the inner wall surface of the restriction passage. Can be reduced and the assembly becomes easy. Therefore, the manufacturing cost of the device can also be reduced.

As the electrorheological liquid, those disclosed in US Pat. No. 2,886,151 or No. 3,047,507 can be used. The polarity of the electrode is such that the first member, which is the outer wall of the restricted passage, is the negative electrode,
It is preferable that the positive electrode is an electrode plate installed on the inner wall surface of the restricted passage.

[0011]

First Embodiment A first embodiment according to the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view of a first embodiment according to the present invention. In FIG. 1, a base plate 2 of this vibration isolator 1 has a mounting bolt 3 projecting from the lower center thereof, and as an example, an automobile It is designed to be fixed to the body. Around the base plate 2 is a cylindrical standing wall portion 2A bent at a right angle, and an upper end portion of the standing wall portion 2A is a flange portion 2B bent at a right angle to the outside. The diaphragm 4 and the partition wall 5 are mounted on the flange portion 2B. An air chamber 8 is formed between the diaphragm 4 and the base plate 2. The air chamber 8 can communicate with the outside if necessary.

The surrounding of the partition wall 5 and the diaphragm 4 are the outer cylinder 9
Is caulked and fixed to the flange portion 2B by the lower end portion of the. The inner diameter of the upper end of the outer cylinder 9 is gradually increased, and the outer periphery of the vibration absorbing main body 10 is vulcanized and adhered. This vibration absorbing body 10
Is formed of rubber as an example. The outer periphery of the support 11 is vulcanized and adhered to the axial center of the vibration absorbing body 10. The mounting bolt 12 projecting from the axis of the support 11 is for fixing an engine (not shown) mounted on the support 11.

The vibration absorbing main body 10 forms a liquid chamber 13 together with the outer cylinder 9 and the diaphragm 4, and the liquid chamber 13 is filled with an electrorheological fluid (not shown). This electrorheological fluid is, for example, 40-60 wt% silicic acid, 30-
50 wt% low boiling organic phase, 50-10 wt% water,
And a mixture of 5% by weight of dispersion medium can be applied, for example isododecane. This electrorheological fluid exhibits the viscosity of a normal fluid under pressure when it is not energized, and has the property of becoming hard by changing its viscosity according to the electric field strength when energized.

As shown in FIG. 2, a through hole 16 is formed in the raised portion 6 formed in the central portion of the partition wall 5. The through hole 16 is closed by a partition cover plate 17 fixed to the raised portion 6 by heat welding, high frequency welding or the like. Therefore, the liquid chamber 13
The partition 5 and the partition cover plate 17 divide the partition into an upper small liquid chamber 14 and a lower small liquid chamber 15. Further, another raised portion 7 is formed at one end of the upper portion of the partition wall 5, and the partition wall cover plate 17 is fixed to the raised object 6 so that the raised object 7, the raised object 6 and the partition wall cover plate are formed. A C-shaped space passage, that is, an orifice 18, which is surrounded by 17 and 17, is formed in a plan view. The outer wall surface 24 facing the inner wall surface 23 of the orifice 18 is formed by the lower end portion of the outer cylinder 9 when the partition wall 5 and the partition cover plate 17 are fitted in the outer cylinder 9.

The orifice 18 has an upper small liquid chamber 14 and a lower small liquid chamber, respectively, through a circular hole 19 formed in the partition cover plate 17 and a cutout hole 20 formed by cutting out one end of the raised portion 6. It communicates with 15. Therefore, the liquids in the upper small liquid chamber 14 and the lower small liquid chamber 15 can flow through each other through the orifice 18 and generate resistance when passing through.

An electrode plate 21 is adhered to the inner wall surface 23 of the orifice 18 so as to be concentric with the C-shaped orifice 18 in a plan view. Here, as the counter electrode arranged so as to face the electrode plate 21, the outer wall surface 24 of the orifice 18 formed by the lower end portion of the outer cylinder 9 is filled. In this embodiment, the outer wall surface 24 is the negative electrode and the electrode plate 21 is the positive electrode. As shown in FIG. 1, lead wires 22 and 22A are fixedly connected to these electrodes and connected to a power source and control circuit (not shown).
An electric field is applied to the electrorheological fluid in 8.
The partition wall 5 in which the lead wire 22 is enclosed must be partially or wholly made of an insulating material such as synthetic resin or ceramics.
The distance between the electrode plate 21 and the outer wall surface 24 of the orifice 18 is, for example, 1 to 2 mm.

Next, the operation of the present invention will be described. The base plate 2 is fixed to a vehicle body (not shown) through the mounting bolts 3, and the engine mounted on the support 11 is fixed by the mounting bolts 12. . Vibration generated in the engine is the support 1
1 is transmitted to the vibration absorbing main body 10 and the vibration is absorbed by internal friction of the vibration absorbing main body 10. This vibration is mainly due to the vibration absorption 1
Since it is transmitted to the liquid chamber 13 via 0, the electrorheological fluid in the liquid chamber 13 moves through the orifice 18, and the vibration is absorbed by the passage resistance during this movement. next,
Since the vibration of the engine is generated over a wide range of frequencies, the electrode plate 21 and the outer wall surface 24 of the lower end of the outer cylinder 9 are energized via the lead wires 22 and 22A accordingly. This causes the electrorheological fluid in the orifice 18 to gradually increase in viscosity. Therefore, if the energization amount is controlled according to the vibration absorption frequency, the vibration can be absorbed over a wide range. In particular, the orifice 18 is the arc-shaped raised portion 6
Since it has a long and slender shape with a long axial dimension, it is possible to obtain various liquid column resonance vibration absorption effects even when engine vibration occurs over a wide range of frequencies.

Specifically, when this embodiment is applied to an engine mount, the bouncing vibration of the engine may occur around 15 Hz and the rolling vibration may occur around 7 Hz. On the other hand, the anti-vibration device does not energize the electrode plate 21 and the outer wall surface 24, tunes the viscosity of the fluid so as to match the bouncing vibration of the engine, and when the rolling vibration occurs, the electrode plate 21 and the outer wall 24 are tuned. By energizing the wall surface 24 and applying a potential difference between the electrodes to increase the viscosity of the fluid, the peak position of high attenuation can be shifted to around 7 Hz.

Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the three electrode plates 25, 26, 27 are arranged along the arc-shaped ridge 6 in the orifice 18 of the first embodiment so as to be coaxial with each other. Therefore, an elongated orifice will be constructed between these electrodes. In addition, since the electric field between the electrodes is inversely proportional to the distance between the electrodes, in this respect, a large electric field can be applied to the electrorheological fluid to efficiently change the viscosity. In this case, the plurality of electrode plates are alternately set to the positive electrode and the negative electrode.

It is also possible to apply a larger number of electrode plates according to the second embodiment. Further, as described above, the first member has only a portion corresponding to the outer wall surface 24 of the limiting passage used as an electrode as a metal member and the other portion as another material such as ceramics or synthetic resin. You can

[0021]

In the vibration isolator according to the present invention, the first member connected to one of the vibration generating portion or the vibration receiving portion and the second member connected to the other of the vibration generating portion or the vibration receiving portion. An elastic member interposed between these members, a liquid chamber that uses the elastic member as a part of a partition wall and is filled with an electrorheological fluid, and a plurality of small liquid chambers that divide the liquid chamber, At least one pair of small liquid chambers communicates with each other, and one electrode is installed on the inner wall of the limited passage to energize the first member as its counter electrode to fill the inside of the limited passage. Since the viscosity of the generated electrorheological fluid is changed, vibrations of various frequencies input to the first or second member are efficiently absorbed, and as described above, the first member is used as an electrode. The number of parts is reduced by using it and the structure of the device It is simplified, and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a first embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a partition wall and an electrode plate of FIG.

FIG. 3 is a longitudinal sectional view showing a second embodiment of the present invention.

FIG. 4 is an exploded perspective view showing a partition wall and an electrode plate of FIG.

[Explanation of symbols]

 1 Anti-vibration device 2 Base plate 3 Mounting bolt 4 Diaphragm 5 Partition wall 6 Raised part 7 Raised part 8 Air chamber 9 Outer cylinder 10 Absorbing body 11 Supporting base 12 Mounting bolt 13 Liquid chamber 14 Upper small liquid chamber 15 Lower small liquid Chamber 16 Through hole 17 Partition cover plate 18 Orifice 19 Circular hole 20 Notch hole 21 Electrode plate 22 Lead wire 22A Lead wire (counter electrode) 23 Inner wall surface 24 Outer wall surface 25 Electrode plate 26 Electrode plate 27 Electrode plate

Claims (1)

[Claims] 1. A first member connected to either one of the vibration generating section and the vibration receiving section; a second member connected to the other of the vibration generating section and the vibration receiving section; An elastic body that is provided between the first member and the second member and that elastically deforms when vibration occurs, and an expandable and contractible liquid chamber that uses the elastic body as a part of a partition wall are provided.
A vibration isolation device further comprising a plurality of small liquid chambers for partitioning the liquid chamber, wherein the partition member for partitioning at least a pair of small liquid chambers among the plurality of small liquid chambers comprises the first member. An elongated limiting passage provided in the partition member as an outer wall and communicating between the pair of small liquid chambers, and an electrorheological fluid filled inside the plurality of small liquid chambers and the elongated limiting passage, An electrode that is provided along the inner wall surface of the elongated restriction passage, and that changes the viscosity of the electrorheological fluid in the restriction passage by energizing the outer wall of the first member as a counter electrode. Anti-vibration device.