JP2002039258A - Pneumatic type active vibration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic type active vibration control device having a switching valve having fresh structure capable of applying a pressure fluctuation on a working air chamber by switching controlling selective connection of the working air chamber to a plurality of air pressure sources different in a pressure value. SOLUTION: By effecting continuous rotation operation of a rotary valve element 90 of a rotary valve 91 by an electric motor 86, the working air chamber 54 is selectively switched and connected to a plurality of air pressure sources 98 and 100 at a period corresponding to the rotation period of the rotary valve element 90.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration connecting member or an anti-vibration support member which is disposed between a vibrating body and an anti-vibration target member to reduce transmission vibration to the anti-vibration target member, and to an anti-vibration member. The present invention relates to a vibration damping device, such as a vibration damper, which is directly attached to reduce the vibration of the vibration damping target member. The present invention relates to a pneumatic active vibration isolator capable of exhibiting a typical vibration isolating effect.

[0002]

2. Description of the Related Art Conventionally, as one type of vibration isolator for reducing vibration in a member to be subjected to vibration isolation, a first mounting member and a second mounting member which are separated from each other are connected by a rubber elastic body. A working air chamber that directly or indirectly exerts an external force on the main rubber elastic body is formed,
By connecting an external air passage to the working air chamber and applying a variation in air pressure transmitted through the external air passage to the working air chamber, vibration of the vibration-proof member to which the first or second mounting member is attached is There has been proposed an active vibration damping device that can reduce or positively reduce the vibration. For example, Japanese Patent Application Laid-Open Nos. 10-184770, 10-184770, and 10-169705
That is described in Japanese Patent Publication No. In such an active vibration isolator utilizing air pressure fluctuations, it is not necessary to incorporate a vibration means such as an electromagnetic driving means into the vibration isolator, and the number of parts is reduced and manufacturability is improved. Reduction in weight and weight can be advantageously achieved. For example, application to various types of vibration-damping target members other than engine mounts and body mounts for automobiles is being studied.

In such an active vibration isolator of the pneumatic vibration type, for example, the working air chamber is provided with a switching valve through an external air pipe in order to apply a pressure change to the working air chamber from the outside. The working air chamber is alternately and repeatedly communicated with two pneumatic pressure sources having different pressures by a switching operation of the switching valve. More specifically, for example, by adopting a negative pressure source and the atmosphere as two air pressure sources, performing a switching operation of the switching valve at an appropriate cycle, and repeating the negative pressure supply to the working air chamber and opening to the atmosphere, A pressure fluctuation corresponding to the switching operation cycle of the switching valve is applied to the working air chamber.

However, in the conventional active vibration isolator, a switching valve for switching between supply to the working air chamber and opening to the atmosphere is formed in a separate housing from the active vibration isolator, and is provided on the external air line. It is difficult to manufacture, handle, and assemble because of the necessity of disposing them in the same space. It is also necessary to secure a separate space for disposing the switching valve, resulting in an increase in the size of the entire device. There was a problem.

In addition, as a switching valve, a reciprocating spool valve or a poppet valve driven by a solenoid, which is often used in a pneumatic line, is simply used as it is. In some cases, it was difficult to ensure the source switching cycle with sufficient speed and accuracy.

[0006]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an alternative to a working air chamber for a plurality of air pressure sources having different pressure values. By switching and controlling the connection
An object of the present invention is to provide a pneumatic active vibration damping device having a switching valve means having a novel structure capable of exerting a pressure fluctuation on a working air chamber.

[0007]

An embodiment of the present invention which has been made to solve such a problem will be described below. The components employed in each of the embodiments described below can be employed in any combination as possible. In addition, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or based on the invention ideas that can be understood by those skilled in the art from the descriptions. It should be understood that it is recognized on the basis of.

That is, in the first aspect of the present invention, the first mounting member and the second mounting member which are separated from each other are connected by the main rubber elastic body, and the first mounting member and the second mounting member are directly connected to the main rubber elastic body. A working air chamber that applies an external force indirectly or indirectly is formed, and an external air passage is connected to the working air chamber so that a fluctuation in air pressure transmitted through the external air passage is exerted on the working air chamber. In a pneumatic active vibration isolator, a rotary valve having a rotary valve body housed and disposed in a housing having a closed structure and located in an air pressure path that applies air pressure to the working air chamber through the external air passage; An electric motor for continuously rotating the rotary valve body is provided, and the working hole connected to the working air chamber and the pressure value of the rotary valve housing are different from each other. By forming a plurality of pneumatic holes connected to the pneumatic pressure source and opening the pneumatic holes at different positions in the housing, the rotation of the rotary valve body causes the working holes to be moved with respect to the plurality of pneumatic holes. The reason is that the connection is made alternatively.

In such an embodiment, in particular, several tens Hz
The switching operation of the pneumatic source in the above high frequency range is required with high precision. In addition to the pneumatic active type vibration damping device, a rotary valve with a rotary valve body is used in combination. The rotating valve body is continuously rotated by an electric motor, whereby the working air chamber is selectively provided to a plurality of air pressure sources at a cycle corresponding to the rotation cycle of the switching valve. , So that the air pressure fluctuates on the working air chamber at a frequency corresponding to the rotation cycle of the switching valve. Then, an external force is directly or indirectly applied to the main rubber elastic body based on the air pressure fluctuation of the working air chamber, so that a destructive or positive vibration damping effect is exerted.

In the active vibration isolator of this aspect, a rotary valve is employed as a switching valve and is continuously rotated by an electric motor.
Since the air pressure source connected to the working air chamber can be switched at a cycle corresponding to the rotation speed of the valve, the air pressure to the working air chamber is smaller than when a conventional solenoid driven reciprocating valve is used. The operation of the switching connection of the source and the control of the air pressure fluctuation of the working air chamber become smooth, and the pressure can be controlled with high accuracy up to a higher frequency range. It is possible to obtain an effective active vibration isolation effect.

The electric motor employed in the present embodiment for driving the rotary valve body to rotate is designed to ensure the switching connection frequency and phase of the air pressure source with respect to the working air chamber with high accuracy and to achieve the desired active control. In order to stably obtain the vibration effect, it is desirable to employ a synchronous motor, and it is also possible to employ a step motor. In particular, by using an electric motor with high control accuracy such as a stepping motor, for example, by controlling the opening amount of a connection passage of an air pressure source to the working air chamber, vibration in pressure applied to the working air chamber can be reduced. It is also possible to approach a sine waveform that is effective at that time.

In the present embodiment, three or more air pressure sources having different pressure values may be employed in accordance with the waveform of vibration to be damped, but at least two air pressure sources are sufficient. Further, at least one opening portion to the housing of the air passage connected to each air pressure source and the working air chamber may be formed at least one per circumference, but three or more openings may be formed according to the waveform of vibration to be damped. It is also possible to employ, for example, in the case of damping a plurality of types of complex vibrations having different frequencies, the opening positions of the air passages connected to the respective air pressure sources may be different from each other in the circumferential direction. . Also,
It is also possible to employ atmospheric pressure as one of the plurality of pneumatic sources, which can substantially reduce the number of pneumatic sources required.

Further, the opening positions of the working hole and the pneumatic hole in the housing of the rotary valve are not particularly limited, and are formed at appropriate positions that can be switched and connected by the rotary valve body. Specifically, for example, air pressure holes are formed in the outer peripheral wall surface of the housing or the axial end surface of the housing, and are provided in the cylindrical outer peripheral wall portion of the rotary valve body, or in a disk plate portion extending in a direction perpendicular to the axis. By opening and closing those pneumatic holes by the communicating holes that
It is possible to open / close the pneumatic holes with the working air chamber.

In the rotary valve, a plurality of pneumatic holes connected to different pneumatic sources should be alternatively connected to the working holes. Are not connected to each other, so that adverse effects such as a decrease in the pressure of the air pressure source due to the connection between the air pressure sources can be avoided.

According to a second aspect of the present invention, there is provided a pneumatic active vibration isolator having a structure according to the first aspect, wherein the rotary valve has a first pneumatic pressure source having different pressure values from each other. With the first air pressure hole and the second air pressure hole connected to the second air pressure source, while configuring the plurality of air pressure holes, with the rotation operation of the rotary valve body,
The working hole is selectively and alternately connected to the first and second pneumatic holes. In this embodiment, the rotary valve is rotated at a constant speed at a substantially constant cycle,
Since the working air chamber is connected alternately to the two pneumatic pressure sources, it is possible to advantageously generate a sine-wave-like air pressure fluctuation in the working air chamber at a frequency corresponding to the rotation speed of the rotary valve. Becomes

A third aspect of the present invention is a pneumatic active vibration isolator having a structure according to the first or second aspect, wherein the active hole and the pneumatic hole in the rotary valve are provided. At least one is characterized in that an opening amount adjusting means for adjusting an area of an opening connected by the rotary valve body is provided. In this embodiment, by changing and adjusting the opening area of the connection portion between the working hole and the pneumatic hole, the width of the air pressure fluctuation exerted on the working air chamber, and further, the external vibration applied to the rubber elastic body of the main body is increased. The amplitude of the force can be adjusted, and therefore
For example, by changing and adjusting the opening area of the connecting portion between the working hole and the pneumatic hole according to the magnitude of the vibration to be damped, the active damping effect can be more efficiently obtained.

According to a fourth aspect of the present invention, there is provided a pneumatic active vibration isolator having a structure according to any one of the first to third aspects, wherein the rotary valve is provided on a wall of the working air chamber. And the working hole formed in the housing is directly opened to the working air chamber. In this embodiment, the length of the air pressure transmission path from the point where the air pressure fluctuation occurs due to the switching of the valve to the working air chamber can be set as small as possible. There is an advantage that the decrease in the air pressure fluctuation width due to the resistance is reduced, and the air pressure fluctuation can be efficiently transmitted to the working air chamber.

According to a fifth aspect of the present invention, there is provided a pneumatic active vibration isolator having a structure according to any one of the first to fourth aspects, wherein the housing of the rotary valve includes Are opened in the peripheral wall surface around the central axis of the rotary valve body, and the plurality of pneumatic holes are selectively formed by the rotary valve body which is slid in the circumferential direction on the peripheral wall surface. The working holes are sequentially opened to communicate with the housing, and the working hole is opened at one end wall surface in the axial direction of the housing, and the air pressure applied to the housing through the air pressure hole connected to the housing is applied to the working hole. The electric motor for driving the rotary valve is disposed on the other side in the axial direction of the housing, while the electric motor is applied to the working air chamber. In this aspect, the space for forming the working hole and the plurality of pneumatic holes in the housing and the space for disposing the electric motor can be efficiently secured, and the overall size can be reduced.

According to a sixth aspect of the present invention, there is provided a pneumatic active vibration isolator having a structure according to any one of the first to fifth aspects, wherein a part of a wall is formed by the main rubber elastic body. And a non-compressible fluid is sealed therein to form a pressure receiving chamber in which a pressure change is generated at the time of vibration input, and another part of the wall of the pressure receiving chamber is elastically supported so as to be displaceable. The working air chamber is provided on the side opposite to the pressure receiving chamber with the vibrating member interposed therebetween, and the vibrating member is elastically vibrated by air pressure fluctuation applied to the working air chamber. It is characterized in that the displacement is controlled to change the pressure in the pressure receiving chamber. In this embodiment, the exciting force is applied to the exciting member by the air pressure variation applied to the working air chamber, and the exciting force is input to the pressure receiving chamber as an external pressure variation. Thus, the pressure fluctuation of the pressure receiving chamber is exerted on the main rubber elastic body, and is transmitted from the main rubber elastic body to the space between the first mounting member and the second mounting member as an exciting force. The Rukoto. Therefore, at the time of vibration input, by exerting a pressure fluctuation corresponding to the input vibration on the working air chamber, the pressure fluctuation generated in the pressure receiving chamber due to the elastic deformation of the main rubber elastic body is positively adjusted,
Vibration exerted on the vibration isolation target member through the rubber elastic body of the main body can be reduced, and the like, and effective vibration isolation characteristics can be exhibited according to the input vibration.

According to a seventh aspect of the present invention, there is provided a pneumatic active type vibration damping device having a structure according to the sixth aspect, wherein the action hole formed in the housing of the rotary valve is directed outward of the housing. The working air chamber is formed by the housing by disposing the vibrating member at the opening of the housing and covering the working hole in a fluid-tight manner with the vibrating member. In this aspect, the vibrating member is supported by using the housing of the rotary valve, and the working air chamber is formed, so that the rotary valve is incorporated into the vibration isolator. Therefore, a special space for disposing the rotary valve is not required, and the handleability is improved, and the overall compactness can be advantageously achieved.

According to an eighth aspect of the present invention, there is provided a pneumatic active vibration isolator having a structure according to any of the sixth and seventh aspects, wherein a part of the wall is formed of a flexible film. An equilibrium chamber in which an incompressible fluid is formed and whose volume change is allowed is formed independently of the pressure receiving chamber, and a first orifice passage communicating the equilibrium chamber with the pressure receiving chamber is formed. The feature is that it did. In this embodiment, a flow action such as a resonance action of the fluid through the first orifice passage is generated based on a relative pressure change caused between the pressure receiving chamber and the equilibrium chamber at the time of vibration input. It will be. Therefore, by utilizing the flow action of the fluid, it is possible to exert a passive vibration damping effect based on the resonance action of the fluid against another frequency vibration different from the operation cycle of the rotary valve. .

According to a ninth aspect of the present invention, in the pneumatic active vibration isolator having a structure according to any of the sixth to eighth aspects, the pressure receiving chamber is connected to the second mounting member. Is divided into two parts by the partition member supported by the above, a part of the wall portion is constituted by the main rubber elastic body on one side sandwiching the partition member, and the pressure is directly applied by the elastic deformation of the main rubber elastic body. In addition to forming the main liquid chamber in which the fluctuation is generated, a part of the wall is formed by the vibrating member on the other side of the partition member, and the pressure fluctuation is directly caused by the displacement of the vibrating member. It is characterized in that a sub-liquid chamber to be generated is formed, and further, a second orifice passage communicating the main liquid chamber and the sub-liquid chamber with each other is provided. In this embodiment, the pressure fluctuation caused in the main liquid chamber based on the elastic deformation of the main rubber elastic body at the time of the vibration input is applied to the sub liquid chamber through the second orifice passage, and the air pressure with respect to the vibrating member is increased. The pressure fluctuation generated in the sub liquid chamber based on the action of the exciting force is applied to the main liquid chamber through the second orifice passage. Therefore, it is possible to obtain a passive vibration damping effect against input vibration by utilizing the resonance action of the fluid that is caused to flow through the second orifice passage, or it is possible to generate a vibration in the auxiliary liquid chamber. By applying the pressure fluctuation to the main liquid chamber with high transmission efficiency, it is possible to improve the active vibration isolation effect.

In the ninth aspect, when the eighth aspect is also employed, it is desirable to set the tuning frequency of the second orifice passage higher than the tuning frequency of the first orifice passage.
Thereby, the effect of improving the vibration isolating effect based on the resonance action of the fluid caused to flow through both orifice passages,
It can be enjoyed advantageously.

According to a tenth aspect of the present invention, there is provided a pneumatic active vibration isolator having a structure according to the eighth aspect, wherein the second mounting member is provided with a tubular portion. The first mounting member is disposed at a distance from one of the openings in the axial direction of the portion, and the cylindrical rubber is elastically connected to the first mounting member and the second mounting member. While the one axial opening of the shape part is covered in a fluid-tight manner,
The other opening in the axial direction of the tubular portion is covered with the flexible film in a fluid-tight manner, and the axially intermediate portion of the tubular portion is fluid-tightly partitioned by a partition wall extending in a direction perpendicular to the axis. The first orifice which forms the pressure receiving chamber on one side in the axial direction with the partition wall therebetween, forms the equilibrium chamber on the other side in the axial direction, and further connects the pressure receiving chamber and the equilibrium chamber to each other. The passage is formed in the outer peripheral portion of the partition, and the partition is used as a housing of the rotary valve, so that the passage is located at the center of the partition and is parallel to the central axis of the cylindrical portion. It is characterized in that a rotary valve provided with a rotary valve body that can be rotated about a central axis is provided. In such an embodiment, a compact pneumatic active vibration damping device having a rotary valve incorporated therein can be realized, and can be suitably used as, for example, an engine mount for an automobile.

According to an eleventh aspect of the present invention, in the pneumatic active vibration isolator having a structure according to any one of the first to fifth aspects, the first mounting member and the second Either one of the mounting members is attached to the vibration-proof target member, the other of the first mounting member and the second mounting member,
The sub-vibration system is constituted by elastically connecting and supporting the vibration-proof member with the main rubber elastic body, and a part of the wall of the working air chamber is formed by the main rubber elastic body. With this configuration, a vibration force is applied to the sub-vibration system by air pressure fluctuations applied to the working air chamber. According to such an embodiment, by exerting air pressure fluctuation on the working air chamber,
The sub-vibration system is vibrated, and the vibrating force is exerted from the first mounting member to the vibration-proof member. Therefore, by controlling the generated excitation force, that is, the fluctuation of the air pressure transmitted to the working air chamber, by a rotary valve, the vibration in the vibration-isolation target member can be offset and the vibration-proof effect can be exerted. A vibration damper can be advantageously implemented.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an engine mount 10 for an automobile according to an embodiment of the present invention. The engine mount 10 has a structure in which a first mounting member 12 as a first mounting member and a second mounting member 14 as a second mounting member are elastically connected by a main rubber elastic body 16. I have. Then, the first mounting bracket 12 is mounted on the power unit of the vehicle, while the second mounting bracket 14 is mounted on the body of the vehicle as a vibration-proof object, so that the power unit is supported on the body in a vibration-proof manner. It has become. In the following description, the vertical direction refers to the vertical direction in the figure in principle.

More specifically, the first mounting member 12 has a substantially inverted truncated cone-shaped block shape, and has a screwed portion 18 integrally formed integrally with the screwing portion 18 projecting axially upward from the large-diameter end surface. The first mounting member 12 is fixedly attached to a power unit (not shown) of a vehicle by a screw hole 20 provided in the screwing portion 18. Further, a flange-shaped stopper portion 22 protruding radially outward is integrally formed on the outer peripheral surface of the large-diameter end portion of the first mounting member 12.

A rubber elastic body 16 is vulcanized and bonded to the first mounting member 12. The main rubber elastic body 16 has a large-diameter generally frustoconical shape as a whole that expands downward and has a large-diameter concave portion 24 that is open at the large-diameter end face. The first mounting member 12 is arranged on the same central axis in a state of being inserted downward in the axial direction from the side end surface, and is vulcanized and bonded. A large-diameter cylindrical metal sleeve 26 is superposed and vulcanized and bonded to the outer peripheral surface of the large-diameter end portion of the main rubber elastic body 16. Further, the main rubber elastic body 16 is
Of the metal sleeve 26
Rubber 27 covering the outer peripheral surface of the main body rubber elastic body 1
6 and are formed integrally. Thus, the main rubber elastic body 16 is formed as an integrally vulcanized molded product having the first mounting member 12 and the metal sleeve 26.

On the other hand, the second mounting member 14 has a large-diameter substantially stepped cylindrical shape, and the upper portion in the axial direction is a large-diameter portion 30 with a step portion 28 formed at an intermediate portion in the axial direction interposed therebetween. The lower part in the axial direction is a small diameter part 32. A thin seal rubber layer 34 covering almost the entire surface is provided on the inner peripheral surface of the small-diameter portion 32 and is vulcanized and adhered. An opening on the small-diameter portion 32 side has a substantially thin disk shape. A diaphragm 36 made of a thin rubber film having the following structure is provided. The outer peripheral edge of the diaphragm 36 is vulcanized and bonded to the peripheral edge of the opening of the second mounting bracket 14, so that the second mounting bracket 14 The lower opening is fluid-tightly closed. In the present embodiment, the diaphragm 36 is
The diaphragm is formed integrally with the sealing rubber layer, and a flexible film is formed by the diaphragm.

The large diameter portion 30 of the second mounting member 14 is externally inserted into the metal sleeve 26 and fitted and fixed by press-fitting, drawing or the like, so that the rubber elastic body 1
6 is fixed to the outer peripheral surface. Thus, the first mounting bracket 12 and the second mounting bracket 14 are arranged on substantially the same central axis so as to be separated from each other in the axial direction which is the main input direction of the vibration to be damped. Are elastically connected by a main rubber elastic body 16. Also, the second mounting bracket 1
By fixing the large diameter portion 30 to the main rubber elastic body 16, the upper opening of the second mounting member 14 is closed by the main rubber elastic body 16 in a fluid-tight manner.

The stopper 2 of the first mounting member 12
2, a cushion rubber 38 protrudes upward in the axial direction and is formed integrally with the main rubber elastic body 16, and a large load is applied between the first fitting 12 and the second fitting 14. When input, the stopper portion 22 is brought into contact with a stopper member (not shown) fixedly provided on the second mounting member 14 side via the cushion rubber 38, so that the first mounting member The amount of relative displacement between the second mounting member 14 and the second mounting member 14 in the direction of separation is buffered.

A partition member 40 serving as a partition portion is accommodated in the second mounting member 14 at an intermediate portion in the axial direction, and is provided with a rubber elastic body 16 and a diaphragm 3.
6 is disposed at an intermediate portion between the opposing surfaces. The partition member 40 is formed of a hard material such as a metal or a synthetic resin, has a circular block shape having a cylindrical outer peripheral surface, and is fitted into the small-diameter portion 32 of the second mounting member 14. The cylindrical outer peripheral surface is fluid-tightly fixed to the small-diameter portion 32 with the seal rubber layer 34 interposed therebetween by press-fitting the small-diameter portion 32 or drawing the small-diameter portion 32. By the partition member 40 being assembled in the second mounting member 14 in this manner, the region formed between the main rubber elastic body 16 and the diaphragm 36 and sealed with respect to the external space is fluidized by the partition member 40. Is divided into two,
Thus, above the partition member 40, a pressure receiving chamber 42 in which a part of the wall portion is formed of the main rubber elastic body 16 and a pressure change accompanying the elastic deformation of the main rubber elastic body 16 is generated at the time of vibration input. On the other hand, on the lower side of the partition member 40,
A part of the wall is constituted by the diaphragm 36, and the equilibrium chamber 44 is formed in which the volume change is easily allowed based on the deformation of the diaphragm 36.

The pressure receiving chamber 42 and the equilibrium chamber 44 respectively contain water, alkylene glycol, polyalkylene glycol, silicone oil,
Alternatively, a mixture or the like thereof is filled and sealed.
The incompressible fluid has a viscosity of 0.1 in order to advantageously obtain a fluid action such as a resonance action of the fluid described below.
A low-viscosity fluid of P · s or less is suitably employed.

The partition member 40 is formed with a substantially mortar-shaped central recess 46 which is opened at the center of the upper surface.
An annular locking projection 48 protruding upward in the axial direction is integrally formed. A vibration rubber elastic plate 50 as a vibration member having a disk shape of a predetermined thickness is superimposed on the opening of the central recess 46, and the vibration rubber elastic plate 5
, A cylindrical locking metal member 52 that is vulcanized and bonded to the outer peripheral surface
However, at the lower end portion, the locking projection 48 of the partition member 40 is provided.
And is caulked and fixed to the locking projection 48.
As a result, the opening of the central recess 46 is
0, and is covered in a fluid-tight manner by the pressure receiving chamber 42.
A working air chamber 54 independent of the balance chamber 44 is formed.

Further, the pressure receiving chamber 42 formed between the main rubber elastic body 16 and the opposing surface of the partition member 40 has a disk-shaped partition as a partition member formed of a hard material such as metal or synthetic resin. The plate 56 is accommodated and disposed so as to spread in the direction perpendicular to the axis of the second mounting member 14. The outer peripheral edge of the partition plate 56 is formed by the step portion 28 of the second mounting member 14 and the rubber elastic body. The body 16 is fixed to the second mounting member 14 by being squeezed and held between the axial end surfaces thereof. Thus, the pressure receiving chamber 42 is fluid-tightly partitioned between the main rubber elastic body 16 and the partition member 40 with the partition plate 56 therebetween. A part of the wall is formed of the main rubber elastic body 16 between the main rubber elastic body 16 and the partition plate 56, and the pressure change accompanying the elastic deformation of the main rubber elastic body 16 at the time of vibration input is directly performed. While a main liquid chamber 58 to be generated is formed, a sub liquid chamber 60 in which a part of a wall portion is constituted by a vibrating rubber elastic plate 50 is formed between the partition plate 56 and the partition member 40. I have.

A substantially disk-shaped orifice member 62 made of a hard material such as metal or synthetic resin is superposed on the lower surface of the partition plate 56, and the outer peripheral edge of the orifice member 62 is formed by a partition. Along with the outer peripheral edge of the plate 56, it is fixed to the second mounting member 14 by being squeezed and held between the step portion 28 of the second mounting member 14 and the axial end face of the main rubber elastic body 16. . This orifice member 62
An outer peripheral portion of the upper surface is provided with an annular peripheral groove 64 which is open on the upper surface and extends in the peripheral direction. The peripheral groove 64 is covered with a partition plate 56 to extend in the peripheral direction.
6 are formed. One end of the upper annular flow path 66 in the circumferential direction is connected to the main liquid chamber 58 through the communication hole 68, and the other end in the circumferential direction is connected to the sub liquid chamber 60 through the communication hole 70. The main liquid chamber 5
The fluid flow through the upper annular flow path 66 is allowed between the sub-liquid chamber 8 and the sub liquid chamber 60 based on the pressure difference between the two chambers 58 and 60.

The circumferential groove 6 in the orifice member 62
The inner peripheral wall portion 4 is externally fitted and fixed in close contact with a locking fitting 52 vulcanized and bonded to the vibration rubber elastic plate 50.
Thereby, the sub liquid chamber 60 is substantially defined between the vibrating rubber elastic plate 50 and the orifice member 62. Also, as is clear from the above description, in the present embodiment,
A second orifice passage is defined by the upper annular passage 66. In the present embodiment, the main liquid chamber 58 is set so that the resonance frequency of the fluid that is caused to flow through the upper annular flow path 66 is a vibration frequency on the high frequency side to be damped, for example, an idling vibration frequency of about 30 Hz. Considering the wall spring stiffness of the sub liquid chamber 60 and the density of the enclosed fluid,
The flow path length and flow path cross-sectional area of the upper annular flow path 66 are set.

Further, in the outer peripheral portion of the partition member 40, a concave groove 72 which is open to the outer peripheral surface and extends in the circumferential direction is formed, and the concave groove 72 is covered by the small diameter portion 32 of the second mounting member 14. Thus, a lower annular flow path 74 is formed. The lower annular flow path 74 has one end formed with a through hole 77 formed in an annular passage 76 formed between the partition member 40 and the orifice member 62 on the outer peripheral side of the vibrating rubber elastic plate 50. Through this annular passage 7
6, through the through-hole 78 formed in the orifice member 62 and to the upper annular flow passage 66, and is communicated with the main liquid chamber 58 through the annular passage 76 and the upper annular flow passage 66. I have. The other end of the lower annular flow path 74 is directly communicated with the equilibrium chamber 44 through the through hole 80. As a result, the main liquid chamber 5 passes through the lower annular passage 74, the annular passage 76 and the upper annular passage 66.
Between the chamber 8 and the equilibrium chamber 44, a fluid flow is generated based on the pressure difference between the two chambers 58 and 44.

As apparent from the above description, in this embodiment, the first orifice passage 75 is formed by the lower annular passage 74, the annular passage 76, and the upper annular passage 66.
Are configured in cooperation. And in this embodiment,
The resonance frequency of the fluid caused to flow through the first orifice passage 75 constituted by the lower annular flow passage 74 and the like is a vibration frequency on the low frequency side to be damped, for example, a shake vibration frequency of about 10 Hz, In consideration of the wall spring rigidity of the main liquid chamber 58 and the equilibrium chamber 44, the density of the sealed fluid, and the like, the flow path length and the flow path cross-sectional area of the lower annular flow path 74 and the like are set.

On the other hand, at the center of the partition member 40,
A hollow valve cavity 82 is formed at a central portion in the axial direction and spreads in a disk shape around the central axis. A circular motor housing recess 84 is formed at the center of the lower bottom wall portion of the valve cavity 82, and an electric motor 86 is fitted into the motor housing recess 84 to be fixed. It is assembled. This electric motor 86
AC type or DC type can be adopted, for example, brushless motor, stepping motor, synchronous motor, etc.
An electric motor capable of setting or controlling the number of revolutions with high accuracy is preferably employed. The output shaft 88 of the electric motor 86 projects from the valve cavity 82 and is located on the central axis of the valve cavity 82. A valve rotating body 90 as a rotary valve body housed and disposed in the valve cavity 82 is fixed to the output shaft 88, and the valve cavity 8
2, the valve rotating body 90 is rotated. In the present embodiment, the housing is formed by the partition member 40, and the partition member 40
The rotary valve 91 is constituted by the valve rotating body 90 and the rotary valve 91.

The valve rotating body 90 has a central boss 92 having a small cylindrical shape and an outer peripheral wall 94 having an outer dimension slightly smaller than the inner diameter of the valve cavity 82. Boss 92 and outer peripheral cylinder wall 9
4 are radially spaced apart on the same central axis, and are integrally connected and fixed by a plurality of (three in this embodiment) spokes 96 extending in the radial direction. The axial dimension of the central boss 92 and the outer peripheral wall 94 is slightly smaller than the axial dimension of the valve cavity 82, while the spoke 96 has the axial dimension of the valve cavity 82. Are sufficiently smaller than the dimension in the axial direction.

The central boss portion 92 is connected to the electric motor 8.
The valve rotor 90 is rotated around the central axis in the valve cavity 82 by being externally fitted to the output shaft 88 and being fixed so as not to rotate relatively. At the time of such rotation operation, the outer peripheral cylindrical wall portion 94 of the valve rotating body 90 is slidably contacted with the peripheral wall surface of the valve cavity 82 and both axial wall surfaces while maintaining a substantially close contact state. .

Further, in the partition member 40 forming the valve cavity 82, first and second air through holes 98 and 100 extending in the radial direction are formed in the axial middle portion. First and second air holes 98,
100 defines two pneumatic holes. These first and second air through holes 98 and 100 are
0 is formed at a portion substantially opposed in one radial direction. In each case, a radially inner end is opened to the peripheral wall surface of the valve cavity 82, while a radially outer end is formed at the partition member 40. Of the second mounting member 14 and through a through hole 102 formed through the small-diameter portion 32 of the second mounting member 14. The opening portions of the first and second air through holes 98 and 100 on the peripheral wall surface of the valve cavity 82 correspond to the valve cavity 8.
2 is covered and closed by the outer peripheral wall 94 of the valve rotating body 90 disposed in the inside.

The outer peripheral cylindrical wall portion 94 of the valve rotating body 90
At each of a plurality of locations (three locations in the present embodiment) located at a predetermined distance from each other in the circumferential direction, notch holes 104 are formed, and the outer peripheral cylindrical wall portion 94 is substantially formed by the notch holes 104. It is divided in the circumferential direction. Then, the valve rotor 90 is rotated, and the notch hole 10 is formed.
4 are the first and second air holes 9 in the partition member 40.
The first and second air holes 98 and 100 are opened and communicated with the valve cavity 82 through the cutout holes 104 when they are aligned with the opening portions of the valve openings 8 and 100.

The position of the cutout hole 104 is such that the relative position in the circumferential direction is different from the relative position in the circumferential direction of the first and second air through holes 98 and 100 formed in the partition member 40. When the valve rotor 90 is rotated at a constant speed, the plurality of notches 104 allow the first air passage 98 and the second air passage 100 to be formed at a substantially constant cycle. The openings are alternately opened in the valve cavity 82. Specifically, in the present embodiment, as clearly shown in FIG. 2, the opening positions of the first air through hole 98 and the second air through hole 100 in the partition member 40 into the valve cavity 82 are On the other hand, three notches 104 are formed in the outer peripheral wall 94 of the valve rotating body 90 at a relative angle of 120 degrees around the central axis. The cross-sectional area of the first and second air holes 9
The cross-sectional area is approximately the same as 8,100. As a result, the inside of the valve cavity 82 is alternately connected and communicated with the first air through hole 98 and the second air through hole 100 at a cycle of 1/3 of the rotation cycle of the valve rotating body 90. It has become so.

Further, in the partition wall member 40 forming the valve cavity 82, an operation hole 106 penetrating in the axial direction is formed in the upper wall portion in the axial direction.
Has an opening at the center of the bottom of a central recess 46 formed in the partition member 40. Thus, the valve cavity 82 is always in communication with the working air chamber 54 through the working hole 106. In other words, the upper end portion of the working hole 106 communicated with the valve cavity 82 is tapered in an upward direction, and the large-diameter opening portion is covered with the vibration rubber elastic plate 50. , A working air chamber 54 is formed.

In the gin mount 10 constructed as described above, the first air passage 98 is opened to the atmosphere in the mounted state, and communicates with the atmosphere as the first air pressure source. On the other hand, an external air line 108 is connected to the second air passage 100, and a negative pressure such as a negative pressure pump or an accumulator as a second air pressure source is supplied through the external air line 108. Source 109
Is connected.

As a result, the engine mount 10
, The electric motor 86 is operated to rotate the valve rotor 9
0, the valve cavity 82 and thus the working air chamber 54 are alternately connected to the atmosphere and the negative pressure source 109 at a cycle corresponding to the rotation cycle of the valve rotating body 90, and the working air chamber When the atmospheric pressure and the negative pressure are alternately applied to the air chamber 54, air pressure fluctuation is applied to the working air chamber 54. Therefore, the air pressure fluctuation of the working air chamber 54 is applied as a vibration driving force to the lower surface of the vibrating rubber elastic plate 50, so that the vibrating force based on the pressure difference between the auxiliary liquid chamber 60 and the working air chamber 54. Is the vibration rubber elastic plate 50
As described above, when the pressure of the working air chamber 54 is changed at a predetermined cycle, a periodic exciting force acts on the exciting rubber elastic plate 50.

Then, as a result of pressure fluctuations occurring in the sub-liquid chamber 60 due to the action of the vibrating force on the vibrating rubber elastic plate 50, a relative pressure change between the main liquid chamber 58 and the sub-liquid chamber 60 is caused. , A fluid flow through the second orifice passage (upper annular passage 66) is generated between the main liquid chamber 58 and the sub liquid chamber 60, and based on the flow action of the fluid, The fluctuation in the pressure in the sub liquid chamber 60 is transmitted to the main liquid chamber 58, and the pressure in the main liquid chamber 58 is positively changed, whereby a destructive or active vibration damping effect is exerted. In particular, in the present embodiment, since the pressure transmission efficiency in the frequency range of the idling vibration is improved by the resonance action of the fluid caused to flow through the second orifice passage 66, the active vibration isolation against the idling vibration is performed. The effect can be exhibited particularly effectively.

The engine mount 10 of the present embodiment
In this case, when a low-frequency large-amplitude vibration such as a shake is input, the main liquid chamber 5
8, a pressure change is generated, and a fluid flow through the first orifice passage 75 is generated based on a relative pressure difference generated between the main liquid chamber 58 and the equilibrium chamber 44 due to the pressure change. Will be squeezed. Then, based on the resonance action of the fluid, a passive vibration damping effect (damping effect) can be effectively exerted against low frequency vibration.

When a vibration such as a shake is input, a relative pressure fluctuation occurs between the main liquid chamber 58 and the sub liquid chamber 60, but the input vibration is caused by a low frequency vibration such as a shake. Since the amplitude is larger than the high frequency vibration such as the idling vibration, the amount of change in the volume of the auxiliary liquid chamber 60 is limited by the spring rigidity of the vibrating rubber elastic plate 50, the contact with the partition member 40, and the like. By restricting the amount of fluid flow through the second orifice passage 66, the amount of fluid flow between the main liquid chamber 58 and the equilibrium chamber 44 through the first orifice passage 75 can be sufficiently ensured. The desired vibration damping effect based on the resonance action of the fluid caused to flow through the orifice passage 75 can be effectively exerted.

As described above, in the engine mount 10 having the above-described structure, passive vibration based on the resonance action of the fluid caused to flow through the first orifice passage 75 with respect to low-frequency vibration such as shaking. On the other hand, for a high-frequency vibration such as an idling vibration, the rotation speed of the valve rotating body 90 by the electric motor 86 is adjusted according to the vibration for the purpose of the vibration prevention. An active anti-vibration effect can be effectively exerted.

In this case, in particular, in order to alternately switch between the first and second pneumatic pressure sources (atmosphere and negative pressure source 109) connected to the working air chamber 54, a specific motor driven by an electric motor 86 is used. Since the rotary valve 91 having the structure is adopted, and the rotary valve 91 and the electric motor 86 as a driving means thereof are incorporated in the engine mount 10, the above-described effective vibration damping effect is exhibited. The engine mount 10 as a possible active vibration isolator can be realized in a compact size.

Further, since the connection of the air pressure source to the working air chamber 54 is switched by a rotary valve, the connection of the working air chamber 54 to the working air chamber 54 is reduced as compared with the case where a conventional reciprocating switching valve is employed. It becomes easy to control the switching cycle of the air pressure source up to a high frequency range with high accuracy, and as a result, it is possible to stably obtain an active vibration isolation effect even in a high frequency range vibration.

Next, FIGS. 3 and 4 show another structural example of a rotary valve which can be suitably adopted in the engine mount according to the first embodiment as a second embodiment of the present invention. I have. In the present embodiment, members and portions having the same structure as the first embodiment are denoted by the same reference numerals as those in the first embodiment in the drawings, and their detailed descriptions are given. Description is omitted.

That is, in the present embodiment, the partition member 40
The first air passage 98 and the second air passage 100 at
Are formed so as to be open with respect to the axial lower end face of the valve cavity 82, are radially opposed to each other across the output shaft 88, and are formed 180 degrees apart in the circumferential direction.

The valve rotator 90 is mounted on the center boss 9.
2 and the outer peripheral cylindrical wall portion 94 are connected to each other at a lower end side in the axial direction by a disk-shaped connecting plate 110 extending in a direction perpendicular to the axis, and the connecting plate 110 connects the lower end surface of the valve cavity 82 in the axial direction. The openings of the opened first and second air through holes 98 and 100 are covered with a fluid-tight cover. An opening window 112 is formed in the connection plate 110 of the valve rotating body 90 so as to extend in an area of about 1/3 in the circumferential direction.
Is rotated around the central axis, so that the opening window 1 is opened.
Only the first and second air passage holes 98 and 100 located at the 12 openings are alternatively opened and communicated with the valve cavity 82 alternately.

Therefore, in the engine mount of the present embodiment employing the rotary valve 113 having such a structure, the same effects as those of the engine mount 10 of the first embodiment can be effectively exhibited. is there.

Further, FIGS. 5 and 6 show, as a third embodiment of the present invention, still another structural example of a rotary valve which can be suitably employed in the engine mount according to the first embodiment. I have. In the present embodiment, members and portions having the same structure as the first embodiment are denoted by the same reference numerals as those in the first embodiment in the drawings, and their detailed descriptions are given. Description is omitted.

That is, in the present embodiment, the valve cavity 82 in which the valve rotating body 90 is accommodated is formed in the partition member 40 with a central axis extending in the direction perpendicular to the axis, and the valve rotating body accommodated therein is formed. 90 is
It can be rotated around a central axis in a direction perpendicular to the axis. In addition, the valve rotating body 90 of the present embodiment includes:
Each of the pair of communication windows 1 has a bottomed cylindrical shape, and is rotated around a central axis so as to penetrate through a cylindrical wall portion.
The first air passage 120 and the second air passage 122 opened on the peripheral wall surface of the valve cavity 82 by the openings 14 and 116 are selectively and alternately opened through the communication windows 114 and 116. , Is communicated with the working air chamber 54 through the hollow interior of the valve rotor 90 disposed in the valve cavity 82.

In the present embodiment, the first and second air passages 120 and 122 are opened at the same position on the circumference and at different positions in the axial direction with respect to the peripheral wall surface of the valve cavity 82. At the same time, a pair of first communication windows 114, 114 communicated with the first air passage 120 and a pair of second communication windows communicated with the second air passage 122 are formed in the cylindrical wall portion of the rotary valve 90. Windows 116, 116
Are formed with a phase difference (relative angle) of 90 degrees from each other.

A rotating shaft 118 projecting outward in the axial direction is fixed to the bottom wall of the valve rotating body 90, and the rotating shaft 118 connects the small-diameter portion 32 of the second mounting member 14. It penetrates and protrudes outside. Then, the rotating shaft 118 is rotationally driven by an electric motor 86 disposed on the outer peripheral side of the small diameter portion 32 of the second mounting member 14 and fixed to the second mounting member 14 by welding or the like. The valve rotating body 90 is rotated around the central axis.

Therefore, in the engine mount of the present embodiment employing the rotary valve 123 having such a structure, the same effects as those of the engine mount 10 in the first embodiment can be effectively exhibited. is there.

FIG. 7 shows a specific example of an active vibration damper 124 according to a fourth embodiment of the present invention. In addition, in this embodiment, about the member and site | part which were made into the structure similar to 1st Embodiment, respectively,
The same reference numerals as in the first embodiment denote the same in the drawings, and a detailed description thereof will be omitted.

That is, in the vibration damper 124, the mass metal fitting 128 serving as the second mounting member is elastically moved by the rubber elastic body 130 serving as the main rubber elastic body with respect to the mounting fitting 126 serving as the first mounting member. The mass fitting 128 is pneumatically excited with respect to the mounting fitting 126 by the atmosphere as the first air pressure source and the negative pressure applied from the negative pressure source 109 as the second air pressure source. You can do it. And the mass fitting 12
By vibrating the vibration system including the rubber member 8 and the rubber elastic body 130 with air pressure, an active vibration damping effect can be exerted on a vibration-proof target member (not shown) to which the mounting bracket 126 is attached. In particular, the mass metal fitting 128
By using the resonance action of a vibration system (sub-vibration system) including the rubber elastic body 130 and the rubber elastic body 130, it is possible to obtain a more effective vibration damping effect.

More specifically, the mounting member 126 has a thick circular block shape and is formed of a hard material such as metal. At the center of the upper surface of the mounting bracket 126, a mounting bolt 132 that protrudes upward is fixedly mounted. The mounting bolt 132 causes the mounting bracket 126 to perform vibration suppression (not shown) such as a vehicle body. It is designed to be fixedly attached to a member to be mounted.

The mounting bracket 126 has an inverted mortar-shaped central recess 134 which is opened at the center of the lower surface in the axial direction. Further, the mounting bracket 126 has a hollow structure, in which a valve cavity 82 is formed, and the valve rotating body 90 is housed and arranged in the valve cavity 82, so that a rotary valve 91 is formed. I have. The structure of the rotary valve 91 is the same as that of the first embodiment. In the drawing, the same reference numerals as those in the first embodiment are assigned to the corresponding members and parts, and the details are given. Detailed description is omitted.

On the other hand, the mass metal fitting 128 is formed of a material having a high specific gravity such as an iron-based metal, has a solid block shape, and is opposed to the mounting metal 126 so as to be spaced downward in the axial direction. .

On one side of the mass metal fitting 128 in the axial direction, a ring-shaped connection metal fitting 136 is spaced apart from each other on the same central axis, and the mass metal fitting 128 and the connection metal fitting 136 are formed in an annular shape. It is elastically connected by a rubber elastic body 130. The rubber elastic body 130 has a tapered cylindrical shape whose diameter gradually decreases toward the lower side in the axial direction, and the small diameter side end face is formed in a conical shape protruding from the central portion of the upper end face in the axial direction of the mass metal fitting 128. Trapezoidal connection part 138
Is vulcanized and adhered to the outer peripheral surface. Also, the mass fitting 128
An inner lower corner portion of the connection fitting 136 opposed to the outer peripheral surface of the connection portion 138 is chamfered in a round shape, and the large diameter end surface of the rubber elastic body 130 is added to the round surface 140. Sulfur adhesive. In short, the outer peripheral surface of the connecting portion 138 of the mass metal fitting 128 and the round surface 140 of the connecting metal member 136 are opposed to each other with a substantially parallel facing surface separated from each other. A rubber elastic body 130 is interposed between the opposing faces of the face 140 and integrally vulcanized and adhered.

Then, the connecting fitting 136 is attached to the mounting fitting 12.
6 is fixed with bolts or the like, so that the mass metal fitting 128
It is elastically supported by 30. In particular, in the present embodiment, the rubber elastic body 130 is disposed on the same central axis as the mass metal fitting 128, and the center of gravity of the mass metal fitting 128 is located on the elastic main axis of the rubber elastic body 130. Thereby, based on the elastic deformation of the rubber elastic body 130, the mass metal fitting 128 can be stably displaced in the center axis direction with respect to the mounting metal 126. In the present embodiment, the rubber elastic body 130 and the mass fitting 1
It is preferable that the mounting is performed in a state where the central axis of the reference numeral 28 extends in a substantially vertical direction which is also the direction of the vibration to be damped in the member to be damped, thereby further stabilizing the displacement of the mass metal fitting 128. Can be

Further, the mass metal fitting 1 is attached to the mounting metal 126.
28, the opening of the central recess 134 formed on the lower surface of the mounting bracket 126 is fluid-tightly covered.
The working air chamber 54 is formed between the opposed surfaces of the mounting bracket 126 and the mass metal fitting 128, including the outer peripheral space.

In the vibration damper 124 having such a structure, the valve rotating body 90 is rotated by the electric motor 86, and the atmospheric pressure and the negative pressure are alternately applied to the working air chamber 54 to generate air pressure fluctuation. By tightening, the pneumatic excitation force is exerted on the mass metal fitting 128, and the auxiliary vibration system is excited.

Therefore, the rotation speed of the valve rotor 90 is
By adjusting the vibration according to the vibration frequency to be damped and applying the exciting force generated in the sub-vibration system to the member to be damped, the vibration that is a problem in the member to be damped is offset. The anti-vibration effect can be obtained.

Also, in the vibration damper 124 of this embodiment, a rotary valve 91 and an electric motor 86 having a specific structure are used to exert air pressure fluctuation on the working air chamber 54. Since it is incorporated, the vibration damper 124 as an active vibration isolator capable of exhibiting the effective vibration damping effect as described above can be realized in a compact size.

Further, since the connection of the air pressure source to the working air chamber 54 is switched by a rotary valve, the connection to the working air chamber 54 is made smaller than when a conventional reciprocating switching valve is employed. It is easy to control the switching cycle of the air pressure source up to a high frequency range with high accuracy, and as a result, it is possible to stably obtain an active vibration damping effect even in a high frequency range vibration.

Although some embodiments of the present invention have been described above in detail, these are merely examples,
The present invention is not construed as being limited by the specific description in these embodiments.

For example, in each of the above-described embodiments, a rotary valve is incorporated in an anti-vibration device such as an engine mount or a vibration damper. It is also possible to arrange a rotary valve on the road. As a rotary valve employed in this case, for example, only the mounting bracket 126 of the vibration damper 124 shown in FIG. By connecting to a working air chamber in the vibration damping device described above, it is also possible to adopt as a rotary valve, and a specific structure can be easily understood. I do.

In the engine mount 10 according to the first embodiment, the equilibrium chamber 44 and the first orifice passage 75 are arbitrarily adopted in accordance with required vibration damping characteristics and the like. It is not necessarily required.

Further, in the engine mount 10 according to the first embodiment, the partition plate 56 and the orifice member 62 are arbitrarily adopted according to required vibration isolation characteristics and the like, and are not necessarily provided. There is no.

Further, it is possible to provide an opening amount adjusting means for adjusting the area of the opening of the air pressure hole. In the following description, members and portions having the same structure as in the first embodiment are denoted by the same reference numerals as those in the first embodiment in the drawings, respectively, so that detailed descriptions thereof are given. Is omitted.

More specifically, as shown in FIG. 8, a shutter sleeve 142 as an opening amount adjusting means is disposed between the peripheral wall of the valve cavity 82 and the opposing surface of the outer peripheral cylindrical wall 94 of the valve rotor 90. Set up. The shutter sleeve 142 has a cylindrical shape having an outer diameter slightly smaller than the peripheral wall of the valve cavity 82 and an inner diameter slightly larger than the outer diameter of the outer cylinder wall 94 of the valve rotating body 90. The valve cavity 82 is disposed so as to be in close contact with the peripheral wall of the valve cavity 90 and the outer peripheral wall 94 of the valve rotator 90 so as to be rotatable relative to each other. The dimensions are almost the same. A through-hole 144 is formed at a position corresponding to the air through-hole 148 so as to extend radially therethrough with a substantially constant cross-sectional area, and the size of the cross-sectional area is substantially equal to the cross-sectional area of the air through-hole 148. It is the same size.

By adjusting the position of the through hole 144 with respect to the air through hole 148, the opening amount of the air through hole 148 is adjusted. For example, the center of the sectional area of the through hole 144 is When the position of the through hole 144 is adjusted so as to coincide with the center of the cross sectional area of the air through hole 148, the opening amount of the air through hole 148 is maximized, and the cross sectional area is equal to the cross sectional area of the air through hole 148.

Here, by employing the shutter sleeve 142 as described above, it is possible to adjust the opening amount of the air through hole 148, and hence the exciting force exerted on the exciting rubber elastic plate (50) Can be adjusted.

Further, at least one through hole 144 for adjusting the opening amount is sufficient, and the air through hole 148 for adjusting the opening amount may be connected to either the atmosphere side or the negative pressure side.

Furthermore, in the above embodiment, the notch 1
By reducing the opening areas of the window 04, the opening window 112, and the communication windows 114 and 116, it is also possible to limit the excitation force.

In addition, it goes without saying that the present invention can be applied to not only engine mounts and vibration dampers for automobiles, but also to anti-vibration devices for automobiles or various devices other than automobiles. It is.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, the present invention can be implemented in a form in which various changes, modifications, improvements, and the like are made.
It goes without saying that all such embodiments are included in the scope of the present invention without departing from the spirit of the present invention.

[0089]

As is apparent from the above description, the active vibration damping device having the structure according to the present invention employs a rotary valve and operates the rotary valve body continuously to rotate. Since the air chamber is switched and connected to a plurality of air pressure sources at a frequency corresponding to the rotation cycle of the rotary valve body, by controlling the number of rotations of the rotary valve body, air pressure fluctuations exerted on the working air chamber are controlled. Frequency can be controlled with high precision. Compared to the case of using a conventional reciprocating valve body, it operates with higher accuracy and more easily at a frequency corresponding to the vibration to be damped up to a higher frequency range. It is possible to control the pressure of the air chamber, and it is possible to improve the active vibration isolation effect against vibration in a high frequency range.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an engine mount as one embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view of another rotary valve suitably adopted in the engine mount shown in FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV in FIG. 3;

FIG. 5 is a cross-sectional view of an engine mount employing still another rotary valve.

FIG. 6 is a sectional view taken along line VI-VI of the valve rotor shown in FIG. 5;

FIG. 7 is a longitudinal sectional view of a vibration damper according to a fourth embodiment of the present invention.

FIG. 8 is a cross-sectional view of a rotary valve provided with a shutter sleeve.

DESCRIPTION OF SYMBOLS 10 Engine mount 12 First mounting bracket 14 Second mounting bracket 16 Body rubber elastic body 40 Partition member 54 Working air chamber 86 Electric motor 90 Valve rotating body 91 Rotary valve 98 First air through hole 100 Second air passage 106 Working hole 108 External air line 109 Negative pressure source

Claims (11)

[Claims] An external force is applied directly or indirectly to a main body rubber elastic body by connecting a first mounting member and a second mounting member spaced apart from each other with a main body rubber elastic body. In a pneumatic active vibration isolator, a working air chamber is formed, and an external air passage is connected to the working air chamber so that a fluctuation in air pressure transmitted through the external air passage is exerted on the working air chamber. A rotary valve having a rotary valve body housed and disposed in a housing having a sealed structure and located in an air pressure path that applies air pressure to the working air chamber through the external air passage, and continuously rotates the rotary valve body of the rotary valve. An electric motor is provided, and a plurality of working holes connected to the working air chamber and a plurality of pneumatic pressure sources having different pressure values are provided in the housing of the rotary valve. By forming the air pressure holes and opening them at different positions in the housing, the operation hole is selectively connected to the plurality of air pressure holes by the rotation operation of the rotary valve body. A pneumatic active vibration isolator. 2. In the rotary valve, the plurality of pneumatic holes are formed by a first pneumatic hole and a second pneumatic hole connected to a first pneumatic source and a second pneumatic source having different pressure values. 2. The device according to claim 1, wherein the working hole is selectively and alternately communicated with the first and second pneumatic holes as the rotary valve body rotates. Pneumatic active vibration isolator. 3. The rotary valve according to claim 1, wherein at least one of the working hole and the pneumatic hole in the rotary valve is provided with an opening amount adjusting means for adjusting an area of an opening connected by the rotary valve body. The pneumatic active vibration isolator according to claim 1. 4. The working air chamber according to claim 1, wherein a housing of the rotary valve is fixed to a wall of the working air chamber, and the working hole formed in the housing is directly opened to the working air chamber. 4. The pneumatic active vibration isolator according to any one of claims 1 to 3. 5. In the housing of the rotary valve, the plurality of pneumatic holes are opened in a peripheral wall around a central axis of the rotary valve body, and the rotation is slid in the circumferential direction on the peripheral wall. The plurality of pneumatic holes are selectively opened sequentially by a valve body to communicate with the housing, and the working hole is opened at one axial end wall surface of the housing to be communicated with the housing. The electric motor for driving the rotary valve body is disposed on the other axial side of the housing while applying air pressure applied to the inside of the housing through the air pressure hole to the working air chamber through the working hole. The pneumatic active vibration isolator according to any one of claims 1 to 4. 6. A pressure receiving chamber in which a part of a wall portion is formed by the main rubber elastic body and an incompressible fluid is sealed to form a pressure receiving chamber in which a pressure change is generated at the time of vibration input. The other part of the wall portion is constituted by a vibrating member elastically supported so as to be displaceable, and the working air chamber is provided on a side opposite to the pressure receiving chamber with the vibrating member interposed therebetween. 6. The pneumatic active vibration isolator according to claim 1, wherein the vibration member is elastically vibrated and displaced by the air pressure fluctuation exerted on the pressure receiving chamber to control the pressure fluctuation in the pressure receiving chamber. apparatus. 7. The vibrating member is disposed in an opening portion of the working hole formed in the housing of the rotary valve to the outside of the housing, and the vibrating member covers the working hole in a fluid-tight manner. 7. The active pneumatic vibration isolator according to claim 6, wherein the working air chamber is formed by the housing. 8. An equilibrium chamber filled with an incompressible fluid, wherein a part of the wall is made of a flexible membrane and volume change is allowed, is formed independently of the pressure receiving chamber. 8. The active pneumatic vibration isolator according to claim 6, wherein a first orifice passage communicating the equilibrium chamber with the pressure receiving chamber is formed. 9. The pressure receiving chamber is divided into two parts by a partition member supported by the second mounting member, so that one side of the partition member is sandwiched between the pressure receiving chamber and the main rubber elastic body to form a part of a wall. Is formed to form a main liquid chamber in which pressure fluctuation is directly caused by elastic deformation of the main rubber elastic body,
On the other side of the partition member, a part of the wall is formed by the vibrating member to form a sub-liquid chamber in which pressure fluctuation is directly caused by displacement of the vibrating member, and further, The pneumatic active vibration isolator according to any one of claims 6 to 8, further comprising a second orifice passage communicating the main liquid chamber and the sub liquid chamber with each other. 10. A cylindrical portion is provided on the second mounting member, and the first mounting member is provided at a distance from one opening in the axial direction of the cylindrical portion. The one axial opening of the cylindrical portion is fluid-tightly covered by the main rubber elastic body elastically connecting the mounting member and the second mounting member, while the other axial opening of the cylindrical portion is provided. Is fluid-tightly covered with the flexible membrane, and the axially intermediate portion of the cylindrical portion is fluid-tightly partitioned by a partition wall extending in a direction perpendicular to the axis, so that one side in the axial direction sandwiching the partition wall And the equilibrium chamber is formed on the other side in the axial direction, and the first orifice passage for interconnecting the pressure receiving chamber and the equilibrium chamber is formed in the outer peripheral portion of the partition. On the other hand, such a partition part is used as a housing of the rotary valve. 9. A rotary valve having a rotary valve body, which is located at a central portion of the partition wall portion and is rotated around a rotation central axis parallel to a central axis of the tubular portion, is provided. 4. The pneumatic active vibration isolator according to 1. 11. One of the first mounting member and the second mounting member is mounted on a vibration-proof member, and the other of the first mounting member and the second mounting member is mounted on the vibration-proof member. Along with constituting a single sub-vibration system by elastically connecting and supporting the main body rubber elastic body to the vibration target member,
2. A vibrating force is exerted on the sub-vibration system by a change in air pressure exerted on the working air chamber by forming a part of a wall portion of the working air chamber with the main rubber elastic body. 6. The pneumatic active vibration isolator according to any one of claims 1 to 5.