JPH0425640A - Vibration isolator - Google Patents

Abstract

PURPOSE:To make it applicable to a large amplitude mechanical vibration by interposing one side of the actuators, adding amplifying mechanism to a vibrating element, between two structures of a vibrating source, and superposing each mechanical vibration output of the vibration and the actuator on each other. CONSTITUTION:Each of actuators 40, 50 is one that is amde up of adding an amplifying mechanism, magnifying the extent of amplitude in the mechanical vibration, to a vibrating element being composed of laminating piezoelectrical ceramics in pile. Each of acceleration censors 60, 61 is attached to an engine side mount jig 4 and a platelike fitting 14 on a rubber base 12, and likewise each of acceleration sensors 62, 63 is attached to a body side mount jig 5 and a supporter 20. Then, each output of these acceleration sensors 60-63 is inputted into an actuator controller 64 which gives an electric vibration conformed to each output of these sensors 60-63 to each vibrating element of both these actuators 40, 50.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vibration isolator that prevents or suppresses the propagation of mechanical vibrations.

[Prior art] JP-A-63-53617 and JP-A-63-261
Japanese Patent No. 300 describes an active vibration isolator in which an actuator is a vibration element that converts electrical vibration into mechanical vibration. Specifically, a structure in which an actuator and a load sensor are connected in series is interposed between two structures, at least one of which is a vibration source, and an acceleration sensor is provided in the vibration source structure. The mechanical vibration of the vibration source structure is converted into electric vibration by the sensor and the acceleration sensor, and based on the electric vibration output, electric vibration input is given to the vibrating element. The active mechanical vibration of the actuator actively cancels out the mechanical vibration of the vibration source, thereby preventing the propagation of this vibration. As an example of the vibrating element, one in which piezoelectric ceramics are layered is cited.

[Problems to be Solved by the Invention] The vibration element made of laminated piezoelectric ceramics used in the above-mentioned vibration isolator has a vibration density of at most 1 μm per 1 mm of the element size, for example.
Only minute dimensional changes on the order of m can be obtained. On the other hand, the amplitude of mechanical vibration of a vibration-proof mount for an automobile engine, for example, is generally about ±0.5 mm to about ±0.05 mm.

Therefore, in order to prevent the mechanical vibration of the engine from being transmitted to the body using the conventional active vibration isolator described above, it is necessary to adopt a vibration element as large as 10 cm to 1 m, which is impossible. Ta.

An object of the present invention is to provide an active vibration isolator applicable to large amplitude mechanical vibrations.

[Means for Solving the Problems] A vibration isolating device according to the present invention includes an actuator that is formed by adding a width expanding mechanism that expands the amplitude of the mechanical vibration to a vibration element that converts electrical vibration into mechanical vibration. It is placed between two structures to superimpose the vibration to be damped and the mechanical vibration output of the actuator, and a sensor is installed in the propagation path of the vibration to be dampened, and the output of this sensor is Based on this, a control means is provided for applying an electric vibration input to the actuator in conjunction with the vibration to be damped.

[Function] The vibration isolating device of the present invention converts the mechanical vibration to be damped by the sensor into electrical vibration and outputs the electrical vibration.

This electric vibration is applied to the vibration element through the control means as an electric signal linked to the vibration to be damped. This vibrating element converts a given electrical signal into mechanical vibration with minute amplitude. The amplitude of this minute amplitude mechanical vibration is expanded by the width expanding mechanism and becomes the actuator mechanical vibration output.

This actuator mechanical vibration output between the two structures is superimposed in the vibration propagation path to be damped, thereby canceling out unwanted mechanical vibrations and achieving the purpose of vibration damping.

Embodiment FIG. 1 is a sectional view of a vibration isolator according to an embodiment of the present invention, and is an example of a case where a conventional liquid damping type engine mount and an active vibration isolator are used together in an automobile.

On the bottom surface of the engine 2 and the top surface of the body 3, the engine 2
engine 2 to prevent mechanical vibrations from propagating to body 3.
Mounting jig for the liquid-damped engine mount IO supporting the 4. '5 are fixedly installed, respectively.

This liquid damped engine mount It is as follows.

A plate-shaped metal fitting 14 is attached to the upper part of the rubber base 12 whose lower surface is formed in a concave shape, and a bolt 16 is inserted upward into this metal fitting 14.
Or it is permanently installed. Further, an outer cylindrical metal fitting 18 is provided which extends downward in a cylindrical shape on the outer periphery of the tapered lower part of the rubber base 12.
is permanently installed. A lower end portion of the outer cylindrical metal fitting 18 is coupled to an open end portion of a bottomed support body 20 having a substantially concave cross section. A bolt 22 is fixed to the support body 20 in a downward direction. An elastic flexible member 24 in the form of a membrane wall is sandwiched between the outer cylinder fitting 18 and the support body 20, and this flexible member 24 closes the upper opening of the support body 20. The structure of the rubber substrate 10 is such that a liquid 26 is sealed in a chamber formed between the body 12 and the elastic flexible member 24. This chamber is divided into two upper and lower liquid chambers 32. by a rigid partition plate 30 having an orifice 28.
It is divided into 34 sections. The outer peripheral edge of the partition plate 30 is sandwiched and held between the outer cylinder fitting 18 and the support body 20 together with the peripheral edge of the elastic flexible member 24 . Orifice 28
has the required length and cross-sectional area to allow fluid 26 to flow between the two fluid chambers 32,34. The space between the support body 20 and the elastic flexible member 24 is an air chamber 36.

The liquid damping type engine mount lO described above is arranged between the engine 2 and the body 3 in the following manner.

The upper part of the engine mount IO is secured to a washer 42 by a bolt 1B fixed to the plate-shaped metal fitting 14, with the actuator 40 inserted between the engine-side mount jig 4 and the plate-shaped metal fitting 14 on the rubber base 12. It is attached to the mounting jig 4 using a nut 44. The lower part of the engine mount 10 is secured with a washer by a bolt 22 fixed to the support body 20 with another actuator 50 inserted between the bottom of the support body 20 and the body-side mount jig 5. 52 and nuts 54 to be attached to the mounting jig 5. The actuators 40 and 50 each have a vibrating element made of laminated piezoelectric ceramics with a width-expanding mechanism added thereto to magnify the amplitude of the mechanical vibration, as will be specifically explained later.

Acceleration sensors 80 and 61 are attached to the engine side mount jig 4 and the plate-shaped metal fitting 14 on the rubber base 12, respectively, and acceleration sensors 62 and 83 are attached to the body side mount jig 5 and the support body 20, respectively. installed. The outputs of these acceleration sensors Go, 81, 62, and 63 are input to the actuator control device 64, and this control device 64 generates electric vibrations according to the outputs of the acceleration sensors 60, 61, and 62, 63 to both actuators at 40° and 50 degrees. Give to element.

FIG. 2 is a longitudinal sectional view showing the detailed structure of the actuator 40. However, similar structures can be adopted for other actuators 50 as well.

A vibrating element 70 formed by vertically stacking piezoelectric ceramics is embedded in a plate-shaped housing 71.

A seal rubber 72 is pasted on the upper surface of the vibrating element 70 to prevent the liquid injected into the chamber 73 above from coming into contact with the vibrating element 70. However, the lowermost cross section of the liquid chamber 73 is the same size as the vibrating element 70, and the cross section becomes smaller toward the top. The lower part 4 between the upper parts of the liquid chamber 73 is closed with a rubber film 75 attached to the upper surface of the housing 71, and the liquid in the liquid chamber 73 is sealed. When the vibrating element 70 extends in the vertical direction, the liquid in the liquid chamber 73 transmits pressure upward according to Pascal's principle, and the rubber membrane 75 swells significantly at the lower portion 4 between the upper parts of the liquid chamber. That is, the vibration element 70 is placed here.
A widening mechanism 76 is formed to expand the amplitude of mechanical vibration. Engine 2 detected by acceleration sensors 60 and 61
The relative mechanical vibration between the plate-like metal member 14 and the metal plate 14 is canceled by the mechanical vibration of the actuator 40 controlled by the actuator control device 64. That is, in the vibration process of the engine 2, when the engine 2 is lowered, the height of the bulge of the rubber film 75 is reduced by the same amount, and when the engine 2 is raised, the height of the bulge of the rubber film 75 is increased.

However, if the liquid chamber 73 is filled with incompressible rubber instead of liquid, a similar actuator 40 can be constructed without using the seal rubber 73 and the rubber film 75. Note that the relative mechanical vibration detected by the acceleration sensor 82.133 on the body 3 side is used to control the actuator 50.

By employing this structure, the thickness of the actuator 40 can be suppressed to, for example, 1 cm or less for the liquid-damped engine mount 10, which is approximately 10 cm in diameter and 10 cm in height. Furthermore, the vibration element 70 has a resistance of 350 kg per cross-sectional area ICm2 against the static load and dynamic load of the engine 2.
It has a sufficiently high load capacity of approximately gf. Moreover, 5H
It can handle mechanical vibrations in a wide frequency range of 500 Hz to 500 Hz.

Next, modifications of the actuator 40 shown in FIGS. 3 to 14 will be described.

In the actuator 40 shown in FIG. 3, a vibrating element 80 formed by laminating piezoelectric ceramics in the left-right direction is embedded in a dish-shaped housing 82 with a lid 81.

Both left and right end surfaces of the vibrating element 80 are in contact with a piston 83 that is slidable in the left-right direction. This piston 83
The outside of the housing 82 is a liquid chamber 84 extending upward, and a small-area upper opening 85 is closed with a rubber film 86 stuck to the top surface of the housing 82 to seal the liquid inside the liquid chamber 84. When the vibrating element 80 extends in the left-right direction, the pressure of the liquid in the liquid chamber 84 is transmitted upward via the piston 83, and the liquid chamber upper opening 8
At position 5, the rubber membrane 86 swells greatly. That is, a width expanding mechanism 87 is formed that expands the amplitude of the mechanical vibration of the vibration element 80 in accordance with the area ratio between the outer end surface of the piston 83 and the upper opening 85 of the liquid chamber. However, if the liquid chamber 84 is filled with incompressible rubber instead of liquid, there is no need to provide the rubber membrane 86.

The actuator 40 shown in FIGS. 4 to 11 employs a pantograph type widening mechanism.

In the actuator 40 shown in FIG. 4, a connecting member 91 is joined to the end of a vibrating element 90 formed by laminating piezoelectric ceramics in the left-right direction, and one end of two upper and lower arms 92 and 93 is connected to this connecting member 91. are each supported.

The other end of the upper arm 92 is pivoted to the end of the upper plate 94, and the end of the lower arm 93 is pivoted to the end of the lower plate 95. That is, a width expanding mechanism 96 that expands the amplitude of mechanical vibration of the vibration element 90 is formed here.

In the actuator 40 shown in FIG. 5, U
The top of a leaf spring 101 bent in a letter-like shape is in contact with the top of the leaf spring 101, and both ends of the leaf spring 101 are pivotally supported by the ends of the upper plate 102 and the lower plate 103, respectively, to form a width expanding mechanism 104. There is.

The actuator 40 shown in FIG.
0b is used. The left vibration element 110a includes the inner surface of the left bent portion of a flexible support member 111 having a flat O-shaped cross section with an open top, and the top of a leaf spring 112 bent in a U shape and supported at both ends by the support member ill. It is sandwiched between the outer surface and the outer surface.

The right vibrating element 110b is held between the inner surface of the right bent portion of the support member 111 and the outer surface of the top of a similar U-shaped leaf spring 113.

In other words, the width expanding mechanism l1 in which the end portions 114 and 115 of the support member 111 are the points of action on the engine side mount jig 4
6 is formed.

The way the support member H1 and the leaf spring 112 are connected may be changed as shown in FIG. 7. Actuator 40 in FIG.
Here, the left vibration element 110a is sandwiched between the outer surface of the left bent portion of the support member 111 and the top inner surface of the leaf spring 112, while the right vibration element 110b is held between the outer surface of the right bent portion of the support member 111 and the top of the leaf spring 113. A width expanding mechanism 117 is formed which is sandwiched between the inner surface and the end portions 114 and 115 of the support member 111 as points of action.

In the actuator 40 shown in FIG. 8, a vibrating element 120 in which piezoelectric ceramics are laminated in the left-right direction is arranged inside a flexible support member 121 having a flat O-shaped cross section.

A pressurizing screw 122 is screwed inward into the left and right bent portions of this support member 121, and the tip of this screw is connected to the outer surface of a contact plate 123 joined to the end surface of the vibration element 120 via a ball 124. and touch it. As a result, the vibration element 12
A widening mechanism 125 is formed to widen the amplitude of the zero mechanical vibration. However, unlike the cases shown in FIGS. 4 to 7, the thickness of the actuator 40 becomes smaller when the vibration element 120 extends.

The actuator 4o shown in FIG. 9 has a vibrating element 130 disposed inside a flexible support member 131, as in the case of FIG.
32 is screwed in, and the tip of the pressurizing screw 132 is brought into contact with the end surface of the vibrating element 130 via the contact plate 133 and the ball 134. However, the difference is that notches 135 are provided in each of the upper and lower arms of the support member 131 to facilitate deformation of these parts. This makes the operation of the width expanding mechanism 13B smooth.

In the actuator 4o of FIG. 10, a vibrating element 140 in which piezoelectric ceramics are laminated in the left-right direction is disposed inside a flexible support member having a flat rectangular cross section and consisting of upper and lower plates 141 and side plates 142. Both ends of the vibrating element 140 are supported by pressurizing screws 143 screwed into the side plate 142.

Further, a rigid support column 144 is arranged along the vibrating element 140, and both ends of this column are pivotally supported by the side plate 142. A notch 1 is provided approximately in the center of the upper and lower plates 141 to facilitate deformation.
45 are provided. When the vibrating element 140 extends, a compressive force acts on the upper and lower plates 141, causing the upper and lower plates 141 to deform, thereby increasing the thickness of the actuator 40. This forms a width-expanding mechanism 146 that expands the amplitude of mechanical vibration of the vibration element 140.

The actuator 40 in FIG. 11 is the width expanding mechanism 9 in FIG.
6 as a unit, which are stacked in two layers, one above the other. The upper unit 147 includes vibration elements 90.1. Upper plate 9
4.1, Lower plate 95. l and upper and lower arms 92.1, 93.
Consists of 1. The lower unit 148 includes a vibration element 90.2,
Top plate 95. L lower plate 95.2 and upper and lower arms 92.2.9
Consists of 3.2. In other words, the lower plate 95 of the upper unit 147
, ] are shared by the upper plate of the lower unit 148. According to this width widening mechanism 149, a width widening ratio twice that of the case shown in FIG. 4 can be obtained. An even larger width expansion ratio can be obtained by combining three or more stages of width expansion mechanisms.

The actuator 40 shown in FIGS. 12 to M14 applies the lever principle to a width expanding mechanism.

The actuator 40 shown in FIG. 12 uses a vibrating element 150 formed by vertically stacking piezoelectric ceramics. This vibrating element 150 is placed inside the bent portion of the L-shaped support member 151, and the horizontal arm 152 is placed above the vibrating element 150. The base of the horizontal arm 152 has an end surface connected to the upright portion of the support member 151 by a leaf spring 153, and a contact plate 15 joined to the upper end surface of the vibration element 150.
4 through the ball 155. The tip of the horizontal portion of the L-shaped support member 151 and the tip of the horizontal arm 152 are connected by a rubber membrane 15B. In other words, horizontal arm 1
A width widening mechanism 158 is formed in which a tip end 157 of 52 serves as a point of action for the engine side mount jig 4. Note that the rubber film 156 functions to pull back the horizontal arm tip 157 that has moved upward.

In the actuator 40 shown in FIG. 13, a vibrating element 160 formed by laminating piezoelectric ceramics in the vertical direction is installed in a recess 16 provided at the lower peripheral edge of the engine side mount jig 4.
It is embedded in 1.

A horizontal arm 162 is arranged below the vibrating element 160.

This horizontal arm 162 extends from the lower end of the mount jig 4 to the upper part of the engine mount 10.
It extends to the vicinity of the bolt 16 fixed to the. The end surface of the base of the horizontal arm 162 is connected to the side surface of the mount jig 4 by a leaf spring 163, and abuts via a ball 165 against the lower surface of a contact plate 164 joined to the lower end surface of the vibrating element 160. In other words, the tip 16 of the horizontal arm 162
A widening mechanism 167 is formed as a point of action on the plate-shaped metal fitting 14 of the engine mount 10.

The actuator 4o in FIG. 14 includes four vibrating elements 170a made of vertically stacked piezoelectric ceramics,
170b, 170c, and 170d are used. Four arms 171a, 171b extend from the bolt 16 fixed to the plate metal fitting 14 at the top of the engine mount 10.

171c and 171d are extended accordingly. However, the two lower arms 171a and 171b are provided between the bottom plate 4a of the mount jig 4 and the metal plate 14, and the remaining two upper arms 171c and 171d are located at a higher position than the mount jig bottom plate 4a. established in Lower arm 171a
, 171b sandwich the lower vibrating elements 170a, 170b between them and the plate-shaped metal fitting 14 at the base, and their tips abut against the lower surface of the mount jig bottom plate 4a. upper arm 171c,
171d holds the lower vibrating element 170cA70d between it and the holding plate 172 at the base, and its tip abuts against the upper surface of the mount jig bottom plate 4a. The holding plate 172 is attached to the bolt 16
It is screwed into a nut 44 and fixed together with the washer 42. As a result, the vibration elements 170a, 170
A widening mechanism 173 is formed to expand the amplitude of the mechanical vibrations 170b, 170c, and 170d. When the mount jig 4 is lowered during the vibration process of the engine, all the arms 171a and 171b are moved by the same size.

Lower the tips of 171c and 171d. For this purpose, the two lower vibration elements 170a and 170b are contracted, and at the same time the two lower vibration elements 170c and 170d are expanded. When the mount jig 4 is raised, the vibration elements 170a, 17
0b.

170e and 170d are made to perform the opposite operation.

Now, the embodiment described above is an example in which the active vibration isolator is used in combination with the conventional liquid damping type engine mount 10, but the embodiment shown in FIG. It is used for

In the actuator 41 of the vibration isolator shown in FIG. 15, the top of a leaf spring 181 bent in a U-shape is attached to each end of a vibration element 180 in which piezoelectric ceramics are laminated in the left-right direction, as in the case of FIG. is in contact with this leaf spring 181
Both ends of the vibration element 180 are pivotally supported by the ends of the upper plate 182 and the lower plate 183, respectively, thereby forming a width expanding mechanism 184 of the vibrating element 180. Flat anti-vibration rubber 1 on the upper surface of the upper plate 182
85 is attached, and a bolt 186 whose head is embedded in this vibration-proof rubber 185 projects upward. This bolt 18
The upper part of the vibration isolator is attached to a mounting jig 4 fixed to the lower surface of the engine 2 by means of B. A flat anti-vibration rubber 187 is similarly attached to the lower surface of the lower plate 183, and a bolt 18g whose head is embedded in the anti-vibration rubber 187 projects downward. The mount jig 5 is fixed to the lower part of the vibration isolator or the upper surface of the body 3 using this bolt 188.
mounted on.

Acceleration sensors eo and e1 are attached to the engine side mount jig 4 and the upper plate 1g2 of the actuator 41, respectively, and acceleration sensors 62 and 83 are attached to the body side mount jig 5 and the lower plate 183 of the actuator 41, respectively. . These acceleration sensors 60, 61, 62.8
The output of No. 3 is input to the actuator control device 64 as in the case of FIG. give.

Modifications of this type of vibration isolator are shown in FIGS. 16 and 17.

The vibration isolator shown in Fig. 16 has upper and lower vibration isolators 185° and 187°.
The shape of the plate-shaped metal fitting 186a is attached to the vibration-proof rubber 185 formed in a concave shape on the lower surface.
A bolt 186 is fixed upwardly to this metal fitting 186a. Further, a plate-shaped metal fitting 188a is attached below the vibration-proof rubber 187 whose upper surface is formed in a concave shape, and this metal fitting 188a
A bolt 188 is fixed downwardly. Other points are the same as those in FIG. 15.

In the vibration isolating device shown in FIG. 17, the lower vibration isolating rubber is omitted, and bolts 188 are directly fixed to the lower plate 183 of the actuator 41. The shape of the upper vibration isolating rubber 185 is the same as that shown in FIG. 16, and a bolt 186 is fixed to a plate-shaped metal fitting 186a.

However, in the case of FIGS. 15 and 16, whether an acceleration sensor was attached to the lower plate 183 of the actuator 41 or
In the case of FIG. 17, this can be omitted.

The vibration isolator shown in FIG. 18 is also used in place of the liquid damping type engine mount IO in automobiles, and employs an actuator 42 applying Pascal's principle as in the case of FIGS. 2 and 3. ing.

This vibration isolator includes a housing 191 that accommodates a vibration element 190 formed by stacking piezoelectric ceramics in the vertical direction, and an upper plate 193 connected above the housing 191 with elastic rubber 192. The vibration element 190 is inserted into a vertically long hole provided in the housing 191. A piston 194 is inserted into the cavity so as to be slidable in the vertical direction via means such as an O-ring, and an actuator chamber 195 is formed below which accommodates the vibration element 190.

Below this actuator chamber 195 is a pressurized bolt 19.
8 is screwed upward, and presses the vibration element 190 against the lower surface of the piston 194 via a spring 197. The hole above the piston 194 is filled with liquid to form the liquid chamber 19.
It is B. The lower cross section of this liquid chamber 198 is the same size as the piston 194, and the cross section becomes smaller toward the top.

A piston 199 is inserted into the upper end of the liquid chamber 198, and this piston 199 passes through the connecting rubber 192 and reaches the lower surface of the upper plate 193. The housing 191 has a downward bolt 200 for connection to the body side mount jig 5.
Upward bolts 201 for connection to the engine side mount jig 4 are fixed to the upper plate 193, respectively.

When the vibrating element 190 extends, the liquid in the liquid chamber 19g transmits pressure upward, and the upper plate 193 is greatly lifted up via the piston 199. That is, a width expanding mechanism 202 that expands the amplitude of mechanical vibration of the vibration element 190 is formed here.

As shown in FIG. 19, the piston 199 is omitted, and a thin tube 2 extending from the upper end of the liquid chamber 198 to the lower surface of the upper plate 193
03 may be provided in the connecting rubber 192 to configure the width expanding mechanism 204. The rest of the structure of the actuator 43 is the same as that shown in FIG. 18, so a description thereof will be omitted.

FIG. 20 is a longitudinal sectional view showing a unit type cylinder that can be used in the vibration isolator of the type shown in the previous two figures.

A vibrating element 21 made of piezoelectric ceramics laminated vertically is housed in a cylinder 211. A piston 212 is slidable vertically inside the cylinder 211 via means such as an O-ring. An actuator chamber 213 that accommodates the vibration element 210 is formed below.
The piston 212 is screwed upward and presses the vibration element 210 in the actuator chamber 213 against the lower surface of the piston 212. The space above the piston 212 is filled with liquid to form a liquid chamber 215. At the upper end of the cylinder 211, a seal member 216 and a pressurizing bolt 217 seal the upper end of the liquid chamber 215. At this time, the pressurized bolt 217
The piston 212 is pressed downward through the . Liquid chamber 2
A pore 219 is provided in the cylinder 211 on the side surface of the cylinder 215 . A small piston is inserted into the small hole 219, or the part that touches the outside is covered with rubber. That is, the vibration element 210 is adjusted according to the area ratio between the piston 212 and the pore 219.
An actuator 44 formed with a widening mechanism 220 is configured to expand the amplitude of the mechanical vibration. In addition, piston 2
A seal rubber 221 is pasted on the top surface of the actuator chamber 213 to prevent liquid from flowing out into the actuator chamber 213.

FIG. 21 shows another seal structure for preventing contact between the vibrating element and the liquid in the unit type cylinder.

A piston 232 is inserted into the cylinder 231 so as to be slidable in the vertical direction via means such as an O-ring, and an actuator chamber 233 that accommodates the vibration element 230 is formed in the lower part, and a liquid chamber 234 is formed in the upper part. . cylinder 23
A lid member 235 is screwed onto the lower end of the piston 232, and this lid member presses the vibration element 230 against the lower surface of the piston 232. Moreover, within the actuator chamber 233, the seal rubber membrane 236 extends from the lower surface of the piston 232 to the inner surface of the lid member 235. Therefore, the liquid in the liquid chamber 234 leaks from the circumferential surface of the piston 232 and enters the actuator chamber 2.
Even if the temperature reaches 33, the vibrating element 230 will not get wet, and deterioration of the vibrating element 230 can be prevented.

Note that, although the relationship shown in FIGS. 4 and 11 is limited, a large width expansion ratio can also be obtained by combining multiple stages of a single width expansion mechanism. In addition, all of the vibration isolating devices described above as embodiments are intended to prevent the mechanical vibrations of the engine from being transmitted to the body of an automobile, but the present invention is designed to prevent the transmission of mechanical vibrations from the engine to the body of an automobile. It can be applied to all cases where the propagation of mechanical vibrations between parts is prevented or suppressed.

[Effects of the Invention] As explained above, the vibration isolator according to the present invention employs, as an actuator for canceling mechanical vibration, a vibrating element in which a widening mechanism for expanding the amplitude of the mechanical vibration is added to the vibrating element. Therefore, it is applicable to large amplitude mechanical vibrations.

Therefore, it is suitably used as an active vibration isolator in engine mounts for automobiles and the like. Moreover, it exhibits a vibration-proofing effect by following the mechanical vibrations of the engine, for example.
It can be used both when driving at a constant speed and when idling.

[Brief Description of the Drawings] Figure 1 is a longitudinal sectional view of a vibration isolator according to an embodiment of the present invention used in conjunction with a conventional liquid damping engine mount in an automobile, and Figure 2 shows the structure of the actuator in the previous figure. 3 to 14 are longitudinal sectional views showing other structural examples of the actuator, and FIG. 15 is another embodiment of the present invention used in place of a conventional liquid damping type engine mount in an automobile. 16 is a longitudinal sectional view showing a modification of the previous figure, FIG. 17 is a longitudinal sectional view showing another modification, and FIG. 18 is a longitudinal sectional view showing a conventional liquid damping device for automobiles. A partially cutaway side view of a vibration isolator according to still another embodiment of the present invention used in place of an engine mount, FIG. 19 is a partially cutaway side view showing a modification of the previous figure, and FIG. 20 is a front two FIG. 21 is a longitudinal sectional view showing a modification of the unit type cylinder shown in the previous figure. FIG. 21 is a partial vertical sectional view showing a modification of the unit type cylinder shown in the previous figure. Explanation of symbols 2...-Automobile engine, 3... Automobile body, 10... Liquid damping type engine mount, 40, 41,
42, 43, 44.50... actuator, 60.
61, 62. If3... Acceleration sensor, 64... Actuator control device, 70.80, 90.90. l, 90.2, 100, 11
0a, 110b, 120, 130° 140.150,
160, 170a, 170b, 170e, 170d, 1
80. 190.210,230... Vibration element, 76.87.
96.104.116.117.125,138,14
6,149,158°167.173,184.202
, 220... widening mechanism. Patent applicant: Toyo Tire & Rubber Industries, Ltd. Toyota Motor Corporation Figure 3 Figure 5 Figure 6 Figure 8 Figure 9 Figure 14 Figure 15\ Figure 18 Figure 19 Figure 21 Figure Addition

Claims (1)

[Claims] 1. An actuator, which is made up of a vibration element that converts electrical vibrations into mechanical vibrations and a width-spreading mechanism that expands the amplitude of the mechanical vibrations, is interposed between two structures, one of which is a vibration source. A vibration isolating device characterized in that the vibration to be damped is superimposed on the mechanical vibration output of the actuator. 2. In the vibration isolating device according to claim 1, a sensor for converting mechanical vibration into an electrical signal is provided in the propagation path of the vibration to be damped, and vibration isolating is attempted for the actuator based on the output of this sensor. A vibration isolator equipped with a control means that provides an electrical vibration input linked to vibration.