JPH01199033A - Control device for vibration isolating device - Google Patents

Abstract

PURPOSE:To improve vibration isolating property by simultaneously changing a damping factor and a spring constant, by a method wherein, based on vibration detected by a single detecting means, viscosity of electric viscous fluid is changed at a given timing. CONSTITUTION:A pair of electrode plates 46 and 48 are situated to an orifice 40 to intercommunicate upper and lower small liquid chambers 32A and 32B partitioned from each other by means of a partition wall plate 38 and 8 diaphragm 16, and the interior thereof is filled with electric viscous fluid. Vibration from a vibration generating part B or to a vibration receiving part A is detected by a displacement sensor 92. In relation to the detected vibration, a pulse generating circuit 82 generates a pulse signal, having a double frequency and a phase displaced by a given amount, through a phase regulating circuit 84. A high voltage is applied on the electrode plates 46 and 48 through a high voltage generating circuit 80, and viscosity of the electric viscous fluid is increased. This constitution enables simultaneous change of a damping factor and a spring constant and improvement of vibration improvement.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a control device for a vibration isolator, and particularly to a control device for a vibration isolator, which is interposed between a vibration generating part and a vibration receiving part, and in which an electrorheological fluid is sealed. The present invention relates to a control device for a vibration isolator that absorbs vibrations using its viscous resistance.

[Conventional technology]

2. Description of the Related Art Some vibration isolators used in automobile engine mounts, cab mounts, bushings, body mounts, etc. are equipped with a liquid chamber partially made of an elastic body. This liquid chamber is divided into two small liquid chambers by a partition wall, and these small liquid chambers are communicated with each other through an orifice. In this vibration isolator, vibrations are absorbed by resistance when the liquid in one small liquid chamber moves toward the other small liquid chamber through an orifice when vibration occurs.

However, in order to deal with vibrations of different frequencies occurring in automobiles, etc., such a vibration isolator must have a structure in which a plurality of orifices of different sizes are provided and each of these orifices is opened and closed by a valve or the like. For this reason, a vibration isolator has been proposed that uses an electrorheological fluid as the fluid and applies an electric field to the electrorheological fluid to change the viscosity of the fluid according to the load (JP-A-60-104828, JP-A-60-104828; Showa 6
1-74930). However, in the vibration isolating device using the electrorheological fluid described above, resonance occurs at the resonance point, the vibration transmissibility becomes higher than in other frequency regions, and the vibration isolation performance in the vibration isolation region deteriorates due to damping. , there is a problem.

For this reason, conventionally, as shown in Japanese Patent Application Laid-Open No. 62-31738, speed detection sensors are attached to the vibration generating section and the vibration receiving section, respectively, and the electric field applied to the electrorheological fluid is controlled based on the outputs of these sensors. The damping coefficient is controlled and adjusted.

[Problem to be solved by the invention]

However, although the vibration isolator interposed between the vibration receiver and the vibration generator can be regarded as a vibration system including a dashpot with a damping coefficient C and a spring with a spring constant, In the conventional technology, only the damping coefficient is adjusted, and therefore, the spring constant changes due to the adjustment of the damping coefficient, and there is a problem in that the vibration isolation performance deteriorates particularly in the vibration isolation area. Furthermore, since two sensors are used, there is a problem that the structure becomes complicated and the cost increases.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a control device for a vibration isolator that has a simple structure, can be manufactured at low cost, and has good vibration damping performance.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a plurality of small liquid chambers formed by partitioning a liquid chamber partially made of an elastic body and filled with an electrorheological fluid; The electrorheological property is controlled by controlling the voltage applied to the electrode of a vibration isolator interposed between the vibration generating part and the vibration receiving part. In a control device for a vibration isolator that changes the viscosity of a fluid, a detection means for detecting vibration of either one of the vibration receiving section and the vibration generation section; a pulse signal generating means that generates a pulse signal that is twice as large and whose phase is shifted by a predetermined amount; and a voltage that applies a voltage to the electrode so that the viscosity of the electrorheological fluid increases in response to the generation of the pulse of the pulse signal. An application means is provided.

[Effect]

According to the present invention, a plurality of small liquid chambers formed by dividing a liquid chamber partially made of an elastic body and filled with an electrorheological fluid, and an orifice that communicates with the plurality of small liquid chambers are provided. A vibration isolator including a vibration absorber and an electrode disposed within the orifice is interposed between the vibration generator and the vibration receiver. The detection means detects vibration in either the vibration receiving section or the vibration generating section. The pulse signal generating means generates a pulse signal having a frequency twice that of the vibration detected by the detecting means and whose phase is shifted by a predetermined amount. The voltage applying means applies a voltage to the electrodes of the vibration isolator so that the viscosity of the electrorheological fluid increases in response to the generation of pulses of the pulse signal. There are some electrorheological fluids whose viscosity increases when a voltage is applied, and others whose viscosity decreases when a voltage is applied. Alternatively, a voltage may be applied in advance and wiped, and when a pulse is generated, the voltage application may be stopped to increase the viscosity.

In this way, by increasing the viscosity of the electrorheological fluid, the damping coefficient becomes larger, and the vibration is attenuated by the flow resistance when the electrorheological fluid moves, but the frequency is twice that of the vibration of the vibration receiving part or the vibration generating part. Since the viscosity increases at the timing when the phase is shifted by a predetermined amount, the damping coefficient and the spring constant change at the same time, thereby making it possible to improve the vibration isolation properties of the vibration isolation area.

The above electrorheological fluid
fluid or electroviscous f
luid), for example, US Pat. No. 288,615
No. 1, US Pat. No. 3,047,507, fluids whose viscosity changes significantly depending on the strength of the electric field can be used.

〔Effect of the invention〕

As explained above, according to the present invention, the viscosity of the electrorheological fluid in the orifice is changed at a predetermined timing based on the vibration detected by a single detection means, so the structure is simple and low cost. In addition to being easy to manufacture, the damping coefficient and spring constant can be changed at the same time to improve vibration isolation.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, a base plate 10 of the vibration isolator has a mounting bolt 12 protruding from the lower center thereof, and this mounting bolt 12 is fixed to a vibration generating section B. As shown in FIG. As the vibration generating section B, for example, the body of an automobile can be adopted.

The periphery of the base plate 10 is a cylindrical standing wall portion 10A bent at right angles, and the upper end of this standing wall portion 10A is a flange portion 10B bent outward at right angles. A diaphragm 16 and a partition wall 20 are mounted on this flange portion 10B. An air chamber 22 is formed between the diaphragm 16 and the base plate 10. This air chamber 22 may communicate with the outside as necessary.

The periphery of the partition wall 20 and the diaphragm 16 are caulked and fixed to the flange portion 10B by the lower end of the outer cylinder 24.

The inner diameter of the upper end of the outer cylinder 24 is gradually enlarged.
The outer periphery of the vibration absorbing main body 26 is vulcanized and bonded to the inner periphery of the main body 4 .

This vibration absorbing main body 26 is made of rubber, for example,
The lower end portion is an extension portion 26 that extends along the inner circumference of the outer cylinder 24.
A, and a part of this extension 26A is connected to the outer cylinder 24 and the partition wall 2.
It is sandwiched between 0 and 0.

The outer periphery of a support base 28 is vulcanized and bonded to the axial center of the vibration absorbing main body 26 . A mounting bolt 30 protruding from the axis of the support base 28 is fixed to a vibration receiver A mounted on the support base 28. As this vibration receiving part A, for example, an engine can be adopted.

The vibration absorbing main body 26 forms a liquid chamber 32 together with the outer cylinder 24 and the diaphragm 16, and the liquid chamber 32 is filled with an electrorheological fluid. For example, a mixture of 40 to 60% by weight of silicic acid, 30 to 50% by weight of a low boiling point organic phase, 50 to 10% by weight of water, and 5% by weight of a dispersion medium can be used as the electrorheological fluid. Indodecane (i
5ododekan) can be applied. This electrorheological fluid has the viscosity of a normal hydraulic fluid when it is not energized, and when energized, its viscosity changes and increases depending on the strength of the electric field.

As shown in FIG. 2, a through hole 36 is formed in the raised portion 2OA formed at the center of the partition wall 20. As shown in FIG. This through hole 36 is closed with a partition cover plate 38 that is fixed to the raised portion 2OA by heat welding, high frequency welding, or the like. For this reason, the liquid chamber 32
The upper liquid chamber 32A is connected to the partition wall 20 and the partition cover plate 38.
and a lower liquid chamber 32B.

A groove having a substantially C-shaped planar shape is bored in the raised portion 2OA,
The opening is closed by the partition cover plate 38 to form an orifice 40. This orifice 40 is connected to the bulkhead cover plate 3
A circular hole 42 formed in 8 and a circular hole 4 penetrating the partition wall 20
4, the longitudinal ends thereof communicate with the upper liquid chamber 32A and the lower liquid chamber 32B, respectively.

Therefore, the fluids in the upper liquid chamber 32A and the lower liquid chamber 32B can mutually flow through this orifice 40, creating resistance when passing through.

Electrode plates 46 and 48 are concentrically bonded to opposing surfaces of the inner periphery of the orifice 40, that is, to the side walls. As shown in FIG. 1, these electrode plates 46, 48 are connected to a high voltage generating circuit 80 by lead wires 50, 52 passing through the inside of the partition wall 20, and are energized when necessary.

The partition wall 20 in which the lead wires 50 and 52 are enclosed must be partially or entirely made of an insulating material such as synthetic resin or ceramics, and for example, the interval between the electrode plates 46 and 480 is 1 to 2 m.
It should be about m.

A displacement sensor 92 is attached to the vibration generating section B to detect the displacement y of the vibration of the vibration generating section B.

The displacement sensor 92 is connected to a phase adjustment circuit 84 that shifts the phase of the displacement y by a predetermined amount δ. The amount of phase shift of this phase adjustment circuit is determined in advance through experiments for each vibration isolator so as to obtain the optimum vibration damping effect.

The phase adjustment circuit 84 is connected to the base of the transistor Tr via the pulse generation circuit 82.

This pulse generation circuit 82 can be constructed of a zero cross point detector and a pulse generator that outputs a pulse of a predetermined width that rises at the zero cross point. The emitter of the transistor Tr is grounded, and the collector is connected to the power supply via the excitation coil L of the relay RY.゛One end of the contact S of the relay RY is connected to the power supply, and the other end is connected to the high voltage generation circuit 8.
Connected to 0. The high voltage generating circuit 80 is connected to the electrode plate 46.48 via the lead wire 50.52 as described above.

Next, the operation of this embodiment will be explained. The vibration generated in the vibration generating part B is transmitted to the vibration receiving part A via the support stand 28 of the vibration isolator, and is also transmitted to the vibration absorbing main body 26 via the support stand 28, where the vibration is caused by internal friction of the vibration absorbing main body 26. is attenuated.

The displacement y due to the vibration of the vibration generating section B is detected by the displacement sensor 92, the phase is adjusted by the phase adjustment circuit 84, and then input to the pulse generation circuit 82.

Here, as shown in FIG. 3, the vibration of the vibration generator B is y
=y, sin wt (where yo is amplitude, W is angular velocity, and t is time), the output of the phase adjustment circuit 84 is y=yOsin (wt + δ). The pulse generation circuit 82 detects the zero-crossing point of the signal output from the phase adjustment circuit 84, and as shown in FIG. Generate a signal. Pulse generation circuit 8
When a pulse is output from transistor Tr
Since the base current flows through the transistor, the transistor is turned on, and as a result, the excitation coil L is excited and the contact S of the relay RY is closed. High voltage is applied. As a result, the viscosity of the electrorheological fluid increases. On the other hand, when no pulse is output from the pulse generation circuit 82, the transistor Tr is turned off, so the contact S of the relay is turned off, and the high voltage is not applied to the electrode plates 46, 48 from the high voltage generation circuit 80, so that the electrorheological fluid is Viscosity does not increase.

On the other hand, the vibration generated in the vibration generator B and transmitted to the vibration absorbing main body 26 via the support base 28 is transmitted to the liquid chamber 32 via the vibration absorbing main body 26, so that the electrorheological fluid in the small liquid chamber 32A is It will move to the small liquid chamber 32B via the orifice 40. At this time, as explained above, the electrode plate 46
．． If a high voltage is applied to 48, the viscosity of the electrorheological fluid increases, so vibrations are attenuated by the flow resistance when the electrorheological fluid moves. On the other hand, when no voltage is applied to the electrode plates 46, 48, the viscosity of the electrorheological fluid does not increase, and therefore the vibration receiving section is prevented from being vibrated by the vibration of the vibration generating section.

FIG. 5 shows a comparison of the damping characteristics with the conventional example when the viscosity is controlled as described above. In addition, curve C1 in Fig. 5 is the damping characteristic when the viscosity is not controlled, curve C2 is the damping characteristic when a constant voltage (4 kV) is applied with a constant load, and curve C is the damping characteristic when the viscosity is not controlled.
3 shows the attenuation characteristics of this example.

By the way, when an engine is used as the vibration receiving part and a vehicle body is used as the vibration generating part, vibrations are generated over a wide range of frequencies. Therefore, by measuring the amount of phase shift that provides the optimum vibration damping effect when the vehicle body is vibrated at the fundamental frequency, and controlling the timing of energizing the electrode plates 46 and 48 based on this amount of phase shift, the above method can be achieved. The damping coefficient and spring constant are varied as described, which allows vibration absorption over a wide frequency band.

In particular, since the orifice 40 has a long shaft dimension, it can cope with engine vibrations occurring over a wide range.

Specifically, when this embodiment is applied to an engine mount, bouncing vibration of the engine may occur around 157, and rolling vibration may occur around 77.

On the other hand, the vibration isolator does not apply current to the electrode plates 46 and 48, but tunes the viscosity of the fluid to match the bouncing vibration of the engine, and when rolling vibration occurs, the electrode plate 46.
By applying current to 6.48 to create a potential difference between the electrodes and increasing the viscosity of the fluid, it is possible to shift the peak position of high attenuation to around 7 Hz.

Furthermore, when an electric field is applied to an electrorheological fluid, there is a response delay of several tens of m5ec from the time the electric field is applied until the viscosity of the viscous fluid changes. By determining the amount of phase shift by experiment so as to be obtained, it is possible to correct this response delay so that the viscosity changes at the required timing. In addition, although the above example explained an example of applying an electric field to an electrorheological fluid to increase its viscosity, it is possible to reduce the viscosity by applying an electric field depending on the components of the electrorheological fluid. The viscosity may be increased by decreasing the electric field and discontinuing the application of this electric field. Further, although an example in which control is performed using an analog circuit has been described above, control may be performed using a digital circuit such as a microcomputer.

Next, a vibration isolating device to which the present invention is applicable will be explained.

FIG. 6 shows a second vibration isolator to which the present invention is applicable (the vibration isolator in FIG. 1 is used as the first vibration isolator).

In this second vibration isolator, the outer periphery of the partition cover plate 38 in the first vibration isolator is bent at a right angle, and a cylindrical vertical wall portion 38
A and is in contact with the outer periphery of the raised portion 2OA, and the vertical wall 3
The lower end portion of 8A is further bent at a right angle to form a flange portion 38.
B, is in close contact with the upper surface of the partition wall 20, and is pressed against the partition wall 20 by the caulked portion at the lower end of the outer cylinder 24. Therefore, in this second vibration isolator, the space between the upper end of the partition wall 20 and the partition cover plate 38 can be reliably closed to form the orifice 40 without leakage.

A third vibration isolator is shown in FIG. 7(A). In this vibration isolator, an opening 56 is formed in the center of the partition cover plate 38, and a movable plate 58 is mounted within this opening 56.

This movable plate 58 has an enlarged diameter portion 58 at the end on the upper small liquid chamber 32A side.
A, and a stopper plate 60 is fixed to the lower liquid chamber 32B side. The outer diameters of the movable plate 58 and the stopper plate 60 are larger than the opening 56, and the distance between the movable plate 58 and the stopper plate 60 is larger than the wall thickness of the partition cover plate 38. Therefore, the movable plate 5
8 is capable of slight displacement (approximately 0.5 mm or less) in the thickness direction of the partition cover plate 38.

Therefore, in this vibration isolator, it is possible to absorb vibrations over a wide range by utilizing the change in the viscosity of the electrorheological fluid caused by energizing the electrode plates 46 and 48, and since the movable plate 58 can vibrate, it is possible to absorb particularly high-frequency minute vibrations. The dynamic spring constant does not increase even when the vibration is received, and therefore muffled sound can be reduced.

A fourth vibration isolator is shown in FIG. 7(B). This vibration isolator is provided with a member capable of minute displacement similar to the vibration isolator described above, but a steel plate 103 capable of minute displacement has a plurality of small holes and is sandwiched between elastic membranes 101 and 102. These elastic membranes 101 and 102 are the bulkhead cover plate 38,
The outer periphery is vulcanized and bonded to the partition wall 20 and has a gap with the iron plate 103, allowing the iron plate 103 to be slightly displaced. The other configurations are the same as those in FIG. 7(A), and the same effects can be obtained.

FIG. 8 shows a fifth vibration isolator.

In this vibration isolator, in addition to the structure of the first vibration isolator, a partition plate 62 is arranged in the upper liquid chamber 32A. This partition plate 62 is arranged approximately at the center of the upper liquid chamber 32A, and has a standing wall portion 62A bent at a substantially right angle around the periphery.
A flange portion 62 in which the lower end of 2A is further bent at a right angle.
B, and this flange portion 62B is pressed and fixed to the partition wall 20 by the lower end portion of the outer cylinder 24. Further, an opening 64 is formed in the center of the partition plate 62.

Therefore, the partition plate 62 substantially divides the upper liquid chamber 32A into two parts, which are communicated with each other through the opening 64.

As a result, in this vibration isolator, in addition to the first vibration isolator, the liquid column resonance generated near the opening 64 can be utilized to further reduce the dynamic spring constant at a specific frequency.

FIG. 9 shows a sixth vibration isolator, and FIG. 10 shows a cross section of this vibration isolator.

This vibration isolator has a through hole 36 in the first vibration isolator.
A plurality of (four in this embodiment) concentric electrode plates 66
．． 68.70.72. These electrode plates are supported by arms 74 that extend over the through holes 36. Further, the electrode plate 66 and the electrode plate 70 are connected to the arm 7.
Electrode plates 68, 72 are connected by similar leads 78 to the high voltage generating circuit 80 described above, by leads 76 passing through 4 and partition walls 20.

Further, the partition wall cover plate 38 has a through hole 38 that communicates with the through hole 36.
'C is formed, and this causes the through hole 38C to become the through hole 3.
6 and communicates with the upper liquid chamber 32A1 and the lower wavelet chamber 32B.

The intervals between the electrode plates 66 to 72 are approximately the same as the intervals between the electrode plates 46 and 48.

Therefore, in this vibration isolator, the cross-sectional area Sa of the orifice that communicates the upper liquid chamber 32A and the lower liquid chamber 32B through the through-hole 36.38C is larger than the cross-sectional area sb of the orifice 40.
The length of the orifice at the through holes 38C and 36 is shorter than the length of the orifice 40.

When absorbing vibration, electrode plates 46, 48 and electrode plates 66 to 72
The orifice 40 and the through hole 38 are
C, orifice 4 by varying the viscosity of the fluid at 36.
0 and the orifices of the through holes 38C and 36 can absorb various vibrations.

Through holes 36 and 38 are used to reduce muffled noise when driving at high speeds.
Preferably, fluid is allowed to pass freely through the orifice of C. In particular, it is also possible to solidify the fluid in the through holes 38C and 36 and communicate the upper liquid chamber 32A and the lower liquid chamber 32B substantially only through the orifice 40. In this case, if the electrode plates 46, 48 are not energized, the orifice 40 will exhibit the same characteristics as an orifice without the electrode plates 46, 48.

As a specific example, when the bouncing vibration of the engine is around 15 & and the pitching vibration is around 77, it is generally impossible to produce high damping at frequencies far apart from -. Therefore, the diameter and length of the orifice 40 are determined so that the frequency peak of the damping force is tuned to 157 when no potential difference is applied to the electrode plates 46, 48 of the orifice 40, and when pitching vibration occurs, the electrode plates 46, 48. It becomes possible to increase the viscosity of the fluid by applying an electric field between 48 and 48, thereby bringing the peak of the damping force to around 77. In this case, a potential difference is applied to the electrode plates 66 to 72 to solidify the fluid within the orifice in this area.

Furthermore, by solidifying the fluid within the orifice 40, the spring constant can be made considerably stiffer. This can be applied when a high load is suddenly applied and the spring constant is temporarily stiffened to prevent the engine from interfering with other parts.

In this vibration isolator, it is preferable that the ratio L/S between the length of the orifice and the cross-sectional area S in the orifice portion be 2 or more.

□A seventh vibration isolator is shown in FIG. 11, in which an elastic body 105 is further attached to the upper part of the support stand 28, and
is vulcanized and bonded to the plate 106 to which is fixed. As a result, fluid no longer flows through the orifice 40, and an increase in the spring constant when the pressure inside the upper liquid chamber 32A increases is reduced.

FIG. 12 shows an eighth vibration isolator.

This vibration isolator is an example applied to a car cab mount, and the upper end of a cylindrical lower vibration absorbing main body 118 made of rubber or the like is vulcanized and bonded to a base plate 116 that is fixed to a car body 112 with bolts 114. .

The inner periphery of a short metal tube 120 is vulcanized and bonded to the outer periphery of the lower end of the lower vibration absorbing main body 118, and a base plate 122 that is caulked and fixed to the short metal tube 120 is attached to the lower vibration absorbing main body 11.
It supports the lower end of 8.

The lower end of an inner cylinder 124 is fixed to the axial center of the base plate 122, and a mounting bolt 128 hanging from a cabin 126, which is a vibration generating part, passes through the inner cylinder 124. A nut 132 is tightened at the tip.

A flat plate 134 is fixed to the upper end of the inner cylinder 124, and between the short cylinder 136 caulked to the outer periphery of the flat plate 134 and the base plate 116 are upper and lower ends of an upper vibration absorbing main body 138 formed in a cylindrical shape using rubber or the like. are vulcanized and bonded.

The interior surrounded by the flat plate 134, the vibration absorbing bodies 118, 138, and the base plate 122 is a liquid chamber 140, which is filled with an electrorheological fluid like the liquid chamber 32 of each vibration isolator.

A partition wall 142 is disposed within the liquid chamber 32, and the liquid chamber 140
is divided into an upper liquid chamber 140A and a lower liquid chamber 140B. This partition wall 142 is mounted on a short tube 143 whose upper end is fixed to the base plate 116, and is suppressed and fixed to this short tube 143 by the lower end extension of the upper vibration absorbing main body 138.

A spacer 144 and a partition cover plate 14 are provided on this partition wall 142.
6 is attached to form an orifice 148 between the partition wall 142 and the cylindrical portion 142A. This orifice 148
has the same shape as the orifice 40 of each of the vibration isolators,
Circular hole 150 in partition wall cover plate 146 and circular hole 15 in partition wall 142
2 to the upper liquid chamber 140A and the lower liquid chamber 140B.

An inner cylinder 124 passes through the inner side of the cylindrical part 142A of the partition wall 142, and a cylindrical rubber 156 is vulcanized and bonded to a ring 154 that is slidably attached to the outer circumference of the inner cylinder 124.

Also in this vibration isolator, electrode plates 46 and 48 are attached to the outer periphery of the cylindrical portion 142A and the inner periphery of the spacer 144, respectively, in the orifice 148, facing each other, and generating high voltage through lead wires 50 and 52. The viscosity of the electrorheological fluid within the orifice 148 can be changed by applying current from the circuit 80.

Therefore, in this vibration isolator as well, the vibration absorption characteristics can be changed by changing the viscosity of the liquid in the orifice 148 when the cabin 126 vibrates.

In addition, with this vibration isolator, the vibration of the cabin 126 is transmitted to the base plate 122 via the mounting plate 128, so when the upper liquid chamber 140A is reduced, the lower liquid chamber 140B is
can be enlarged, and the fluid flow rate within the orifice 148 can be increased.

FIG. 13 shows a ninth vibration isolator.

The ninth vibration isolator has approximately the same configuration as the first to eighth vibration isolators described above, so the same parts are given the same reference numerals and explanations are omitted. The main difference is that a C-shaped orifice is provided. A support plate 160 provided with mounting bolts 30 is fixed to the top of the vibration absorbing main body 26 . Small liquid chamber 32A and small liquid chamber 32B
A partition wall 20 made of an insulating material is arranged to separate the two, and a thin-walled portion is formed approximately in the center of the partition wall 20. In addition, around the thin wall portion of the partition wall 20,
As shown in FIG. 14, which is a plan view of the partition wall 20, a substantially C-shaped through groove is bored, and substantially C-shaped electrode plates 162, 164, and 166 are arranged in parallel within this groove. A substantially C-shaped orifice 168.1 is formed between the electrode plate 162 and the electrode plate 164 and between the electrode plate 164 and the electrode plate 166.
70 is formed. And electrode plates 162, 164.
166 are each connected to the high voltage generation circuit 80 via each lead wire 172. According to this vibration isolator,
The electrode plates 162 and 166 are connected to the anode (or cathode) of the high voltage generation circuit, and the electrode plate 164 is connected to the cathode (or anode) of the high voltage generation circuit, and by controlling the voltage as described above, the inside of the orifice is The viscosity of the electrorheological fluid can be changed.

Next, a vibration-proof bushing to which the present invention is applicable will be explained.

A first anti-vibration bushing is shown in FIGS. 15-17.

In this anti-vibration bushing, a hollow shaft 210 is fixed to a base (not shown), and an outer cylinder 212 is disposed coaxially with this shaft 210, so that the outer cylinder 212 can be attached to an industrial machine or the like that is a source of vibration. It has become.

A cylindrical elastic body 214 made of rubber or the like is vulcanized and bonded to the outer periphery of the shaft 210 . The outer periphery of this elastic body 214 is
It is vulcanized and adhered to the inner circumference of 6.

By press-fitting the intermediate cylinder 216 into the outer cylinder 212, the elastic body 214 is substantially attached between the shaft 210 and the outer cylinder 212, and supports the outer cylinder 212 to the shaft 210. In such a first vibration-proof push, it is desirable that the outer cylinder 212 be made of an insulating material. Intermediate cylinder 216 and outer cylinder 21
2, an O-ring 218 is attached to the outer periphery of the intermediate cylinder 216.

The intermediate cylinder 216 has a pair of openings 22 on opposite sides of the axis.
0 is formed, and following this opening 220, an elastic body 2 is formed.
A portion of the outer circumference of 14 is cut out, thereby forming small liquid chambers 224 and 224 inside the outer cylinder 212. These chambers 224, 224 are filled with electrorheological fluid.

A groove is formed on the outer periphery of the intermediate cylinder 216 to communicate the pair of openings 220, and this groove forms a restriction passage 226 between the intermediate cylinder 216 and the inner periphery of the outer cylinder 212. Therefore, this restriction passage 226 communicates the pair of small liquid chambers 224, 224 with each other.

A stopper piece 228 is fixed to the outer periphery of the shaft 210, and the outer periphery of the stopper piece 228 is covered with a part of the elastic body 214. Therefore, this stopper piece 228
It has the role of a stopper that limits the amount of relative displacement in the radial direction between the outer cylinder 212 and the outer cylinder 212 to a predetermined position.

Electrode plates 230 and 232 are attached to the side walls of the restriction passage 226 and are disposed facing each other within the restriction passage 226. The spacing between these electrode plates 230 and 232 is preferably about 1 mm.

Further, these electrode plates 230 and 232 are connected to the high pulse generation circuit 82 shown in FIG. 1 via lead wires 234 and 236, respectively. These leads 234.2
36 passes through the interior of the intermediate cylinder 216. For this reason, it is preferable that the intermediate cylinder 216 is partially or entirely made of a synthetic material (sealed or made of an insulating material such as ceramics), or has a structure in which an insulating film is applied to the outer periphery of the lead wires 234 and 236.

Further, as explained in the vibration isolator, a displacement sensor is attached to the base or the vibration source.

When the vibration-proof bushing configured in this way is attached to the shaft 210 and the outer cylinder 212 to a base and an industrial machine (not shown),
Vibration passes through the outer cylinder 212 to the intermediate cylinder 216 and the elastic body 214.
transmitted to. The elastic body 214 absorbs the vibration by internal friction.

Further, due to this vibration, the fluid in the small liquid chambers 224, 224 passes through the restriction passage 226, and the vibration is also absorbed by the resistance during this passage.

Also, the electrode plate 230.2 is connected to the electrode plate 230.2 via the lead wires 234.236.
When electricity is applied to 32, the electric field increases in accordance with the amount of electricity applied, so that the viscosity of the electrorheological fluid in the restriction passage 226 gradually increases, and the resonant frequency of the fluid shifts to the lower frequency side. Therefore, the state can be changed from a state in which the electrode plates 230 and 232 are not provided, to a state in which the fluid in the restriction passage 226 is completely solidified (the dynamic spring constant increases), and a state in which the restriction passage 226 is closed. The flow resistance can be adjusted to absorb vibrations over a wide range of frequencies.

As an example, let us assume that the frequency at which shimmy occurs is 17 to 187, and in order to suppress this, it is sufficient to increase the voltage so that a large loss occurs at this frequency.

In this way, changing the spring constant can contribute to improving the ride comfort and handling stability of the vehicle.

Next, in Figures 18 and 19, a second anti-vibration bushing is shown.

In this anti-vibration bushing, an insulating plate 242 is interposed between the restriction passage 226 and the outer cylinder 212 in the anti-vibration bush. Therefore, in this anti-vibration bushing, the outer cylinder 21
The electrode plate 230.2 is also formed of a conductive material.
232 can maintain an insulated state.

Next, a third anti-vibration bushing is shown in FIGS. 20.21.

In this anti-vibration bushing, the outer periphery of the intermediate cylinder 216 and the outer cylinder 212
An elastic body 244 is interposed between the outer circumference and the outer periphery of the elastic body 244 . This elastic body 244 may be fixed to the outer periphery of the intermediate cylinder 216 in advance and press-fitted into the inner periphery of the outer cylinder 212, or the outer cylinder 212 may be made a little larger in advance, turned to the right, and placed over the intermediate cylinder 216. It may be fixed by caulking, or conversely, it may be fixed to the inner periphery of the outer cylinder 212 in advance and then press-fitted into the outer periphery of the intermediate cylinder 216. In these cases, it is preferable to squeeze the axial end of the outer cylinder 212 inward and caulk it to the intermediate cylinder 216.

Therefore, if the elastic body of this anti-vibration bushing is made of a non-conductive material, the insulation state of the electrode plates 230 and 232 can be maintained even when the outer cylinder 212 is made of a conductive material, and the liquid chamber can be kept in an insulated state. Seal can be ensured.

Next, a fourth anti-vibration bushing is shown in Figures 22 and 23.

In this anti-vibration bushing, the electrode plates 230 and 232 arranged inside the restriction passage 226 are arranged not on both sides of the restriction passage 226 in the width direction, but on the bottom surface near the shaft 210 and the outer peripheral surface near the outer cylinder 212. Therefore, in this anti-vibration bushing, if the intermediate tube 216 is made of an insulating material, the insulated state of the electrode plates 230 and 232 can be maintained even if the outer tube 212 is made of a conductive material.

A fifth anti-vibration bushing is shown in Figures 24 and 25.

This anti-vibration bushing has a ring groove 24 on the inner circumference of the outer cylinder 212.
A restriction passage 226 is formed between the ring groove 246 and the outer periphery of the cylindrical body 248 by the cylindrical body 248 that is press-fitted into the inner periphery of the outer cylinder 212 . Also ring groove 2
An electrode plate 230 is arranged on the bottom surface of the lead wire 34.
is connected to.

The cylindrical body 248 has circular holes 2 corresponding to the small liquid chambers 224 and 224.
50 are respectively formed, thereby restricting passages 226
are in communication with the small liquid chambers 224, 224. ring groove 2
A spacer 252 is attached to fill an unnecessary gap between 46 and the cylindrical body 248.

Further, the lead wire 36 is connected to the cylindrical body 248, so that the cylindrical body 248 constitutes the other electrode.

A part of the elastic body 214 wraps around the outer periphery of the intermediate cylinder 216 in this anti-vibration bushing, and therefore, this part of the elastic body 214 that wraps around ensures a seal between the intermediate cylinder 216 and the inner periphery of the cylinder 248. I'm going to

Next, a sixth anti-vibration bushing is shown in Figures 26 and 27.

In this anti-vibration bushing, a shaft 210 is made of an insulating synthetic resin or ceramics, and a ring groove 254 is formed on the outer periphery of the shaft 210, and an intermediate cylinder 258 is press-fitted through a ring 256 on the outer periphery of the shaft 210. The space between them is a restricted passage 226. For this purpose, an opening 260 is formed in the intermediate cylinder 258 to communicate with the small liquid chambers 224, 224. The opening 260 also communicates with a through hole 262 formed in the stopper piece 228, thereby communicating the restriction passage 226 with the small liquid chambers 224, 224 through the opening 260 and the through hole 262.

The electrode plate 230 in this anti-vibration bushing has a ring groove 25
4, and the intermediate tube 258 constitutes the other electrode plate.

Also, in this anti-vibration bushing, a part of the elastic body 214 is formed around the outer periphery of the intermediate cylinder 216, as in the above-mentioned anti-vibration bushing, thereby ensuring a secure seal between the bushing and the outer cylinder 212. .

Next, a seventh anti-vibration bushing is shown in Figures 28 and 29. This anti-vibration bushing has a structure in which the electrode plate 232 of the fourth anti-vibration bushing is omitted, and the outer cylinder 212 made of a conductive material serves as the other electrode plate.

Next, FIG. 30.31 shows an eighth anti-vibration bushing. In this anti-vibration bushing, the ring groove 25 formed on the outer periphery of the shaft 210 is similar to the sixth anti-vibration bushing.
4 and the through hole 262 that passes through the stopper piece 228 communicates with the small liquid chambers 224 and 224, but this anti-vibration bushing differs in that electrode plates 230 and 232 are arranged on both sides of the ring groove 254. ing.

Next, a ninth anti-vibration bushing is shown in Figures 32 and 33.

In this anti-vibration bushing, a restricted passage 226 is formed through the shaft 210, into which the electrode plates 230, 232 are arranged. Therefore, like the first vibration-proof bushing, the intermediate cylinder 2
It is not necessary to form a restrictive passage 226 to the outer periphery of 16.

However, unlike the first anti-vibration bushing, the shaft 210 cannot be formed into a cylindrical shape, so screw holes 64 are formed from both ends of the shaft 210 in the axial direction, and the screw holes 64 protrude from a base (not shown) into the screw holes 64. The screw shaft is screwed together.

Next, a tenth anti-vibration bushing is shown in Figures 34 and 35.

This anti-vibration bushing is provided with a vibration shaft 266 that radially passes through the shaft 210, and both ends of the vibration shaft 266 are located within the small liquid chambers 224 and 224, respectively.
It is 68.270.

Also, the interval between these enlarged diameter portions 268 and 270 is 2.10 mm
It is slightly larger than the external shape.

Therefore, in this anti-vibration bushing, the vibration shaft 266 slightly vibrates in the radial direction of the shaft 210 at a predetermined frequency, thereby making it possible to absorb vibrations at a specific frequency.

The other configurations are the same as the first anti-vibration bushing.

The vibration shaft 266 may be attached to the outer cylinder 212 side instead of the shaft 210.

Next, an eleventh anti-vibration bushing is shown in Figures 36 and 37.

In this anti-vibration bushing, the vibration shaft 266 in the anti-vibration bushing is eccentrically formed from the axis of the shaft 210,
This differs in that the shaft 210 is hollow so that a mounting shaft can pass through its axial center.

Next, a twelfth anti-vibration bushing is shown in FIGS. 38-40.

In this vibration-proof bushing, in addition to the restriction passage 226 in the first vibration-proof bushing, a restriction passage 226A is formed on the opposite outer periphery of the intermediate cylinder 216, so that the small liquid chambers 224, 224 are connected to the restriction passage 226, the restriction passage 226A.

However, the electrode plate 230.232 in this anti-vibration bushing
is arranged only in the restricted passage 226, and the restricted passage 2
26A. As a result, the restricted passage 2
Only the viscosity of the electrorheological fluid within 26 can be changed.

Next, FIGS. 41 to 44 show a thirteenth anti-vibration bushing.

In this anti-vibration bushing, an insulating plate 271 with an opening-shaped cross section is provided inside the restriction passage 226 connecting the small liquid chamber 22 and the small liquid chamber 24.
is attached, and electrode plates 230 and 232 are arranged at one end in the width direction and the center in the width direction of this insulating plate 271. Therefore, the inside of the restriction passage 226 is divided into restriction passages 226C and 26D by the electrode plate 232, and the small liquid chambers 224 and 224 are divided into restriction passages 226C and 26D.
are connected to each other via.

The film 272 that supplies electricity to the electrode plates 230 and 232 has a conductive material 274 and 27 inside it, as shown in FIG.
6 passes through the elastic body 214, and this film 272
By being embedded therein, power is supplied through the exposed portions 274A, 276A of the conductive material 274, 276. The film 272 can be vulcanized and bonded to the elastic body 214,
Even if the elastic body 214 is deformed, stress concentration around the film 2720 is small.

However, if possible, it is desirable to insulate the intermediate cylinder 216 by embedding it in an insulating material such as synthetic resin or ceramics.

Therefore, in this anti-vibration bushing, the electrode plate 230.23
By energizing 2, the viscosity of the electrorheological fluid in the restriction passage 226C can be changed and the passage resistance can be changed.
The electrorheological fluid in the restricted passage 226D can always obtain a constant resistance value regardless of the amount of current applied.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is an exploded perspective view showing the partition part of the vibration isolator shown in Fig. 1, and Fig. 3 is a line showing the output waveforms of the displacement sensor and the phase adjustment circuit. figure,
FIG. 4 is a diagram showing the output waveform of the pulse generation circuit, FIG. 5 is a diagram comparing the attenuation characteristics of this embodiment and the conventional example, and FIG. 6 is a diagram showing the second prevention to which the present invention can be applied. 7(A) and (B) are sectional views showing third and fourth vibration isolating devices to which the present invention is applicable, and FIGS. 8 and 9 are sectional views showing the present invention, respectively. 10 is a sectional view showing the fifth and sixth vibration isolators to which
1 and 12 are vertical cross-sectional views showing seventh and eighth vibration isolators to which the present invention is applicable, and FIG. 13 is a vertical cross-sectional view showing a ninth vibration isolator to which the present invention is applicable. Fig. 14 is a plan view of the partition wall of the ninth vibration isolator, and Fig. 15 is a longitudinal cross-sectional view showing the first vibration isolator bushing (corresponding to the cross section taken along line xv-xv in Fig. 16).
, FIG. 16 is a sectional view taken along the line XVI-XVI in FIG. 15 (7),
Fig. 17 is an exploded perspective view showing the main parts of Fig. 15 (the elastic body is omitted), and Fig. 18 is a longitudinal cross-sectional view showing the second anti-vibration bushing (cross-sectional view taken along the xV■-xvm line in Fig. 19). Equivalent to)
, FIG. 19 is a sectional view taken along the line XIX-XIX in FIG.
Figure 0 is a vertical cross-sectional view (corresponding to the cross section taken along line xX-xX in Figure 21) showing the third anti-vibration bushing, Figure 21 is a cross-sectional view taken along line XXI-XXI in Figure 20, and Figure 22 is 23 is a cross-sectional view taken along the line XVI-XVI in FIG. 22, and FIG. 24 is a longitudinal cross-sectional view showing the anti-vibration bushing No. 4 (corresponding to the cross section taken along the line xxn-XX■ in FIG. Longitudinal cross-sectional view showing bush (
Corresponding to the cross section taken along the line XIX-XIX in Figure 25), 25th
The figure is a sectional view taken along the line xx-xX in FIG. 24, and FIG. 26 is a longitudinal sectional view showing the sixth anti-vibration bushing (XX
X
28 is a longitudinal sectional view showing the seventh anti-vibration bushing (corresponds to the xxvm-xx ■■ line sectional view in Fig. 29), and Fig. 29 is the XX I X section in Fig. 28. -XX
I X-ray cross-sectional view, Figure 30 is a longitudinal cross-sectional view showing the eighth anti-vibration bushing (corresponds to the XXX-XXX cross-section in Figure 31), Figure 31 is Figure 30 (7) XXXI-XXXIX
2 is a longitudinal cross-sectional view showing the ninth vibration-proof bushing (corresponding to the cross-section taken along the line Xxxn-xxxn in FIG. 33);
Fig. 33 is a sectional view taken along the line XXXIII-XXI of Fig. 32 (7), and Fig. 34 is a longitudinal sectional view showing the tenth anti-vibration bushing (corresponding to the sectional view taken along the line XXXIV-XXX IV in Fig. 35).
, FIG. 35 is a cross-sectional view taken along the line XXXV-XXXV in FIG. 34 (7), and FIG. 36 is a vertical cross-sectional view showing the eleventh vibration-proof bushing
Fig. 37 (It) corresponds to the XXXVI-XXXVI line cross section), Fig. 37 is XXXvn-xxxvn of Fig. 36.
38 is a longitudinal sectional view showing the 12th anti-vibration bushing (corresponding to the XXXVIII-XXXVI line section in FIG. 39 and the XXXvm-xxxvm line section in FIG. 40 (7)); Figure 38 117) XXX I X-
XXX I X-ray sectional view, Figure 40 is Figure 38 (7)
41 is a longitudinal sectional view showing the thirteenth anti-vibration bushing (XXXXI-X in FIG. 42).
(corresponds to the cross section along line XXXI), Figure 42 corresponds to the X in Figure 41.
43 is an exploded perspective view showing the relationship between the electrodes and the conductive film in this anti-vibration bushing, and FIG. 44 is a sectional view of the film. 16... Diaphragm, 20... Partition wall, 26... Vibration absorbing main body, 32... Liquid chamber, 32A... Upper liquid chamber, 32B... Lower liquid chamber, 38... Partition cover plate, 40... Orifice, 46.48.66.68.70.72... Electrode plate, 80... High voltage generation circuit, 82... Pulse generation circuit.

Claims (1)

[Claims] (1) a plurality of small liquid chambers formed by partitioning a liquid chamber partially made of an elastic body and filled with an electrorheological fluid; and an orifice that communicates the plurality of small liquid chambers; a vibration isolator that changes the viscosity of the electrorheological fluid by controlling a voltage applied to the electrode of a vibration isolator interposed between a vibration generator and a vibration receiver, the vibration isolator comprising: an electrode disposed in an orifice; In the control device of the apparatus, a detection means for detecting vibration of either the vibration receiving section or the vibration generating section;
pulse signal generating means for generating a pulse signal having twice the frequency and having a predetermined amount of phase shift relative to the vibration detected by the detecting means; A control device for a vibration isolator, comprising: voltage applying means for applying a voltage to the electrode so as to increase viscosity.