JPH10238588A - Damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damper, effectively producing an active damping effect, through simple structure. SOLUTION: A rigid partition member 16 and a mass member 18 are disposed at a mounting metal fitting 14, mounted on an object 12 to be damped, with a given distance therebetween in an exciting direction. The members 14, 16, and 18 are intercoupled in series through first and second rubber elastic substances 20 and 22. Meanwhile, a first operation air chamber 36 having a wall part, a part of which is formed of a rubber elastic substance 20, is formed between the mounting metal fitting 14 and the rigid partition member 16 and a second operation air chamber 48 having a wall, a part of which is formed of a rubber elastic substance 22, between the rigid partition member 16 and the mass member 18. By independently controlling the air pressure of the first and second air chambers 36 and 48, the mass member 18 is excited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damper mounted on a vibration damping object to reduce vibration in the vibration damping object, and more particularly to a vibration damper capable of actively reducing vibration.

[0002]

2. Description of the Related Art A dynamic vibration absorber (dynamic damper) has been widely known as one means for reducing the vibration of a vibration damping object such as an exhaust pipe of an automobile or a body where vibration is a problem. Have been. In recent years, in order to obtain a more advanced vibration damping effect, an active vibration damper that suppresses or controls the vibration of the vibration damping target by applying a vibration force to the vibration damping target has been proposed. As one type, Japanese Patent Application Laid-Open Nos. 3-292219 and 6-2
Japanese Patent No. 35438 discloses that a mass member is supported via a spring member with respect to an attachment member attached to an object to be damped, thereby forming a vibration system, and an electromagnetic force exerting an exciting force on the mass member of the vibration system. There is disclosed a vibration damper in which a driving mechanism is provided to exert a large excitation force on a vibration damping target by using a vibration action of a vibration system.

However, in such a conventional vibration damper,
Since the electromagnetic drive mechanism must be incorporated, there is a problem that an increase in size and weight cannot be avoided.
Moreover, in addition to the necessity of coils and magnets, the electromagnetic drive mechanism requires that the coils and magnets be incorporated with high dimensional accuracy in order to stably obtain the desired driving force. There is a problem that the structure is complicated, difficult to manufacture, and expensive. Furthermore,
In a conventional vibration damper using an electromagnetic drive mechanism, reliability and durability may become problems due to its complicated structure, and there is also a problem that it is difficult to cope with a failure.

Further, in the conventional vibration damper, an effective vibration damping effect utilizing the resonance action of the vibration system is exhibited in the natural frequency range of the vibration system constituted by the spring member and the mass member. It was difficult to obtain an effective damping effect for vibrations in other frequency ranges, and thus it was difficult to obtain an effective damping effect for a plurality of or wide frequency range vibrations. There was.

[0005]

Here, the inventions according to claims 1 to 4 are all made on the background of the above-mentioned circumstances, and the problem to be solved is a simple structure and a small number of parts. It is an object of the present invention to provide a vibration damper having a novel structure that is configured with a score and can exert an effective excitation force on a mass member of a vibration system, and can be advantageously reduced in size and weight. .

Further, the inventions according to claims 3 and 4 provide a vibration damper having a novel structure capable of exhibiting an effective vibration damping effect for a plurality of vibrations in a wide frequency range. It is also the purpose.

[0007]

In order to solve such a problem, the invention according to claim 1 comprises: (a) a mounting member to be mounted on a vibration damping target; and (b) vibration damping for the mounting member. A mass member that is spaced apart in the input direction of power vibration,
(C) a rigid partition member disposed between the mounting member and the mass member and separated from the mounting member and the mass member in a direction of input of vibration to be damped;
(D) a first rubber elastic body interposed between the mounting member and the rigid partition member to elastically connect the two members, and (e) between the rigid partition member and the mass member. (F) a part of a wall portion is constituted by the second rubber elastic body elastically connecting the two members, and (f) the first rubber elastic body; Sealed first working air formed between the members and exerting a relative displacement force on the rigid partition member relative to the mounting member in an input direction of vibration to be damped based on a change in internal pressure; (G) a first air supply / discharge passage for applying air pressure to the first working air chamber to cause a pressure change;
Part of the wall portion is constituted by the second rubber elastic body,
A sealing member formed between the rigid partition member and the mass member, and for exerting a relative displacement force on the rigid partition member in an input direction of vibration to be damped against the mass member based on a change in internal pressure; And (i) applying air pressure to the second working air chamber to produce a pressure change in the second working air chamber that is independent of the first working air chamber. And a second air supply / discharge path for the vibration damper.

In the vibration damper having the structure according to the first aspect of the present invention, the mass member is elastically supported by the mounting member via the first and second rubber elastic bodies. Constitutes a vibration system, and the mass member is displaced and vibrated by repeatedly generating pressure changes in the first working air chamber and the second working air chamber.

Therefore, in such a vibration damper, it is sufficient to simply form a specific working chamber inside, and special members such as coils and permanent magnets are provided in order to constitute actuator means for exciting the mass member. There is no need to incorporate
As a result, a vibration damper capable of exhibiting an active vibration reduction effect is advantageously realized with a simple structure and a small number of components. In addition, such a vibration damper is excellent in manufacturability and inexpensive in cost because it has a small number of parts and does not require high dimensional accuracy unlike an electromagnetic drive mechanism.

Further, in the vibration damper having the structure according to the first aspect of the present invention, two independent working air chambers for exerting a displacement force on the mass member are provided.
By appropriately adjusting the air pressure exerted on these two working air chambers, the exciting force exerted on the object to be damped can be set over a very wide range, whereby a plurality of or wide frequency ranges can be set. It is also possible to obtain an effective vibration damping effect for the vibration at.

In addition, in such a vibration damper, it is possible to use the rigid partition member as a mass member by appropriately setting the mass of the rigid partition member. Since the system is configured, by utilizing the resonance action of each vibration system, etc.
There is also an advantage that a more effective vibration damping effect can be obtained with respect to vibrations in a plurality or a wide frequency range.

The invention described in claim 2 is the first invention.
In the vibration damper having a structure according to the invention described in the above, the air pressure applied to the first working air chamber and the second working air chamber, respectively, in synchronization with the frequency of vibration to be damped, substantially It is characterized in that an air pressure control device that fluctuates in the same phase is provided.

[0013] In the vibration damper having the structure according to the second aspect of the present invention, the air pressure is applied to the two independent working air chambers through the independent air supply / discharge passages. Responsiveness by air supply and exhaust is improved by reducing the resistance of the supply and exhaust pipes, and it is possible to exert a large amplitude or displacement force on the mass member,
A large excitation force can be exerted on the vibration damping target, and the vibration damping effect can be improved.

[0014] The invention according to claim 3 provides the invention according to claim 1.
Or, in the vibration damper having a structure according to the invention described in 2, the air pressure applied to the first working air chamber and the second working air chamber is synchronized with different frequencies of vibration to be damped. It is characterized in that a pneumatic pressure control device which fluctuates each is provided.

In the vibration damper having the structure according to the third aspect of the present invention, it is possible to apply a displacement force to the mass member in a form in which two different frequencies are combined. Therefore, an effective vibration damping effect can be obtained for two types of vibrations that are input simultaneously.

The invention described in claim 4 is the first invention.
4. A vibration damper having a structure according to any one of claims 3 to 3, wherein the air pressure applied to one of the first working air chamber and the second working air chamber is set to a substantially constant air pressure. , A pneumatic pressure control device for maintaining and changing the air pressure applied to one of the first working air chamber and the second working air chamber in synchronization with the frequency of the vibration to be damped. , Features.

In the vibration damper having the structure according to the fourth aspect of the present invention, by appropriately setting the air pressure of either the first working air chamber or the second working air chamber, Based on the air spring action of the working air chamber and the change in the wall spring stiffness of the working air chamber, the spring constant of the vibration system can be appropriately changed and set, whereby the natural frequency of the vibration system can be changed. Can be adjusted.

Therefore, in such a vibration damper, the air pressure of any one of the working air chambers is appropriately set in accordance with the frequency of the vibration to be damped, and the natural frequency of the vibration system is adjusted to the frequency of the vibration to be damped. , It is possible to obtain an effective vibration damping effect with respect to vibrations over a plurality of or wide frequency ranges.

It is, of course, possible to provide a plurality of pneumatic pressure control devices according to the second, third, and fourth aspects of the present invention and switch the pneumatic pressure control operation according to the vibration of the vibration damping target.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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.

First, FIG. 1 shows a vibration damper 10 according to a first embodiment of the present invention. This vibration damper 10
With respect to a mounting bracket 14 as a mounting member mounted on the vibrating body 12 as a vibration damping target, a partition bracket 16 as a rigid partition member and a mass bracket 18 as a mass member are respectively separated by a predetermined distance. They are arranged in series, and are elastically connected to each other by a first rubber elastic body 20 and a second rubber elastic body 22 interposed therebetween. In addition, in the vibration damper 10 of the present embodiment, effective vibration control is performed on vibration input in the vertical direction in FIG. 1 which is the serial arrangement direction of the partition metal 16 and the mass metal fitting 18 with respect to the mounting metal 14. The vibration effect can be exhibited.

More specifically, the mounting member 14 has a thick disk shape, and a mounting bolt hole 24 is formed in the center of the upper surface. Further, a first air supply / discharge passage 26 extending through the inside is formed in the mounting bracket 14, and one end of the first air supply / discharge passage 26 is formed on the outer peripheral surface of the mounting bracket 14. , The other end on the lower surface of the mounting bracket 14,
Each is opened. A port 28 for connecting an air pipe to the first air supply / discharge passage 26 is provided on the outer peripheral surface of the mounting bracket 14. Then, the upper surface of the mounting bracket 14 is superimposed on the vibrating body 12,
The mounting bolt 30 is screwed into the mounting bolt hole 24 and is fixed to the vibrating body 12.

The partitioning member 16 has a thin disk shape, and is arranged to face downward at a predetermined distance on the same central axis as the mounting member 14. The mounting member 14 and the partition member 16 are elastically connected by a first rubber elastic body 20 interposed between their facing surfaces. The first rubber elastic body 20 has a large-diameter tapered cylindrical shape whose diameter increases toward the lower side in the axial direction, and the outer peripheral edge of the mounting bracket 14 is vulcanized to the small-diameter side end. On the other hand, an annular block-shaped connecting fitting 32 is vulcanized and bonded to the large-diameter end. The connecting metal fitting 32 is placed on the upper surface of the outer peripheral edge of the partition metal fitting 16 and is fixed by a plurality of fixing bolts 34, so that the first rubber elastic body 20 allows the outer peripheral edge of the mounting metal fitting 14. The portion and the outer peripheral edge of the partition member 16 are elastically connected.

Further, since the mounting member 14 and the partition member 16 are connected by the first rubber elastic member 20 in this manner, the first rubber elastic member is provided between the opposing surfaces of the mounting member 14 and the partition member 16. The first working air chamber 36 is formed by an outer peripheral wall portion 20 and sealed from the external space. Then, for the first working air chamber 36,
A first air supply / discharge passage 26 formed in the mounting bracket 14 is open and communicated with the first air supply / discharge passage 26.
Supply and exhaust of air to and from the first working air chamber 36 are performed.

On the other hand, the mass metal fitting 18 has a thick circular block shape, and is located at a predetermined distance further below the partition metal fitting 16 on the same central axis as the mounting metal fitting 14 and the partition metal fitting 16. As a result, the partitioning member 16 is opposed to the mounting member 14 with the partition member 16 interposed therebetween. Further, a second air supply / discharge passage 38 extending through the inside of the mass metal fitting 18 is formed, and one end of the second air supply / discharge passage 38 is formed on the outer peripheral surface of the mass metal fitting 18. The other end is opened on the upper surface of the mass metal fitting 18, respectively. The opening of the second air supply / discharge passage 38 on the outer peripheral surface of the mass fitting 14 is provided with the mass fitting 1.
A recess 40 is formed on the outer peripheral surface of the recess 4, and a second air supply / discharge passage 38 is opened on the bottom surface of the recess 40. An opening end of the second air supply / discharge passage 38 on the outer peripheral surface of the mass metal fitting 14 is provided with a second air supply / discharge passage 38.
A port member 42 for connecting an air pipeline to the air hole is press-fitted and fixed, and protrudes into the recess 40.

The mass metal member 18 is elastically connected to the partition metal member 16 by a second rubber elastic body 22 interposed between their facing surfaces. The second rubber elastic body 22 has a large-diameter cylindrical shape, and a lower surface of an outer peripheral portion of the partition member 16 is vulcanized and bonded to an upper end in the axial direction, while the second elastic member 22 is vulcanized. A ring-shaped connecting fitting 44 is vulcanized and bonded to the lower end. Then, the connecting metal fitting 44 is placed on the upper surface of the outer peripheral edge of the mass metal fitting 18 and fixed by a plurality of fixing bolts 45, so that the outer peripheral edge of the partitioning metal fitting 16 is formed by the second rubber elastic body 22. The portion and the outer peripheral edge of the mass metal fitting 18 are elastically connected. In addition, the partition fitting 16 and the connecting fitting 4
In each of the facing surfaces of No. 4, at the vulcanization bonding portion of the second rubber elastic body 22, an annular projection 46 projecting in the opposite direction and entering the second rubber elastic body 22 is integrally formed. A large bonding area is secured to the second rubber elastic body 22.

Further, since the partition member 16 and the mass metal member 18 are connected by the second rubber elastic member 22 as described above, a second rubber elastic member is provided between the opposing surfaces of the partition metal member 16 and the mass metal member 18. A second working air chamber 48 is formed by forming an outer peripheral wall portion 22 and hermetically sealed from the external space. Then, for the second working air chamber 48,
A second air supply / discharge passage 38 formed in the mass fitting 18 is opened and communicated with the second air supply / discharge passage 38.
Supply and exhaust of air to and from the second working air chamber 48 are performed.

In the vibration damper 10 having the structure described above, as shown in the drawing, a mounting bracket 14 is fixed to a vibration body 12 to be damped, such as a body of an automobile, by a mounting bolt 30. In this way, the mounting bracket 14 and the partitioning bracket 1 can be moved in the vibration direction in which vibration is to be prevented in the vibrating body 12.
6. The vibration damper 10 is mounted on the vibration body 12 in a state where the mass metal fittings 18 and the first and second rubber elastic bodies 20 and 22 connecting them are positioned in series with each other. Becomes In the vibration damper 10 thus mounted, the mounting bracket 14 and thus the vibrating body 12
On the other hand, based on the elastic deformation of the first and second rubber elastic bodies 20 and 22,
The relative displacement is performed in the vibration direction in which the vibration is to be prevented.

The port 2 provided on the mounting bracket 14
8 and the port member 42 provided on the mass metal fitting 18,
The air pipes 50 and 51 are connected to each other. Through the air pipes 50 and 51, the first air supply / discharge path 26 is connected to the first switching valve 52 and the second air supply / discharge path is connected. 38 is connected to the second switching valve 54. Then, by the switching operation of the first switching valve 52,
The first working air chamber 36 is alternatively connected to the negative pressure source 56 and the atmosphere, and the second working air chamber 48 is switched by the switching operation of the second switching valve 54. , Is connected to the negative pressure source 56 and the atmosphere. As the negative pressure source 56, in addition to a negative pressure pump and an accumulator, in a motor vehicle, a negative pressure of an intake system of an internal combustion engine or the like is advantageously used. Also, as the first and second switching valves 52 and 54, electromagnetic valves and the like which can be switched at a high speed are preferably employed. Furthermore, these first and second switching valves 5
The switching operation of the switching devices 2 and 54 is controlled by a control device 58. In this embodiment, the air pressure control device is configured by the first and second switching valves 52 and 54 and the control device 58. .

Then, in such a vibration damper 10,
First switching valve 52 and / or second switching valve 54
Are switched to apply a negative pressure and an atmospheric pressure to the first working air chamber 36 and / or the second working air chamber 48 alternately. Thus, a displacement force is exerted on the mass metal fitting 18 in a direction (approach / separation direction) facing the mounting metal fitting 14. That is, the mounting metal 14 and the mass metal fitting 18 are opposed to each other in the vibration direction in which vibration is to be prevented, with the first working air chamber 36 and the second working air chamber 48 interposed therebetween. Based on the elastic deformation of the elastic body 20 or the second rubber elastic body 22, they are connected to each other so as to be relatively displaceable in the approaching / separating direction, so that the first working air chamber 36 or the second working air chamber 48 By applying pressure, the first rubber elastic body 20 or the second rubber elastic body 22 is elastically deformed, and the mass metal fitting 18 is displaced closer to the mounting metal 14 on the central axis.

The mass fitting 18 is displaced with respect to the mounting fitting 14 at a cycle corresponding to the switching cycle of the first switching valve 52 and the second switching valve 54. By adjusting the switching cycle of the switching valves 52 and 54, the mass metal fitting 18 can be vibrated at an arbitrary frequency and is applied to the first working air chamber 36 and / or the second working air chamber 48. By adjusting the magnitude of the negative pressure, it is possible to control the excitation force or amplitude exerted on the vibrating body 12 by the excitation of the mass metal fitting 18.

Therefore, the control unit 58 controls the vibrating body 12
Switching control of the first switching valve 52 and / or the second switching valve 54 in accordance with the frequency and amplitude of vibration of the vibrating body 12 to be damped based on the reference signal corresponding to the vibration state of By adjusting the negative pressure and the like, an effective excitation force is exerted on the vibrating body 12, and an effective vibration suppression effect or vibration control effect can be obtained. In particular, the mass metal fitting 18 and the first and second rubber elastic bodies 2
In the natural frequency range of the vibration system composed of 0, 22 and the like, a larger exciting force is efficiently exerted on the vibrating body 12 by the resonance action, so that a more excellent vibration suppression effect or vibration control is achieved. The effect is exhibited.

In particular, the vibration damper 10 structured as described above
In the above, the working air chamber formed between the mounting bracket 14 and the mass metal fitting 18 and vibrating the mass metal fitting 18 based on a pressure change is formed on both sides in the vibration direction of the mass metal fitting 18 by the partition metal 16 made of a rigid material. And for each working air chamber 36, 38 a separate switching valve 52,
Since air is supplied and discharged through the air passages 54 and the air conduits 50 and 51, the responsiveness of the mass metal fitting 18 by supplying and discharging air to and from the working air chambers 36 and 38 is advantageously ensured, and As a result, a large air chamber volume can be ensured, and the amplitude of the mass metal fitting 18 and thus the generated excitation force can be set large. That is, by applying the same phase air pressure change to the first working air chamber 36 and the second working air chamber 48, the mass metal fitting 18 can be largely displaced with excellent responsiveness. Since the vibrating force exerted on the vibrating body 12 by the vibration system including the mass metal fitting 18 and the first and second rubber elastic bodies 20 and 22, and furthermore, the vibration damping effect on the vibrating body 12 can be obtained extremely advantageously. is there.

Moreover, in the vibration damper 10, the first working air chamber 36 capable of exerting a displacement force on the mass metal fitting 18 is provided.
And the second working air chamber 48 are formed independently, and the supply and discharge of air to and from the working air chambers 36 and 48 are mutually independent by the first switching valve 52 and the second switching valve 54. Therefore, an effective vibration damping effect can be obtained with respect to various vibrations by controlling the air pressure of the two working air chambers 36 and 38.

That is, for example, the first working air chamber 36
The vibrating body 1 is displaced by changing the air pressure in the other air chamber while maintaining the air pressure in one of the air chambers 48 and the second working air chamber 48 constant.
When an exciting force is applied to the second air chamber 2, the air pressure of the one air chamber is changed to form a vibration system of the mass metal fitting 18 determined by the air spring and the wall spring rigidity due to the air pressure of the one air chamber. It is possible to adjust the spring constant of the supporting spring. Therefore, when the frequency of the vibration to be damped in the vibrating body 12 changes for some reason, the air pressure of one of the air chambers is changed to make the vibration system of the mass metal fitting 18 unique. The frequency can be adjusted to match the frequency of the vibration to be damped, so that even if the frequency range of the vibration to be damped changes, the mass An effective vibration damping effect based on the resonance action of the vibration system 18 can be exerted, and an excellent vibration damping effect can be exerted on any of a plurality of vibrations over a wide frequency range.

Further, by setting an appropriate mass to the partitioning member 16, the partitioning member 16 and the mass metal member 18 are made into a mass system, and the first rubber elastic body 20 and the second rubber elastic body 22 are formed.
, A vibration system having two degrees of freedom is configured as a spring system, so that the vibration damper 10 has a plurality of natural frequencies, and an effective vibration system based on the resonance action of the vibration system in each natural frequency region. It is also possible to obtain a great damping effect.

That is, for example, when vibrations to be damped in the vibrating body 12 occur simultaneously in two different frequency ranges, the natural frequency of the vibration system having the partition member 16 as a mass is determined. While tuning to the first vibration frequency range to be performed, the switching operation of the first switching valve 52 is performed in accordance with the first vibration frequency, while the natural frequency of the vibration system having the mass metal fitting 18 as a mass. Is tuned to a second vibration frequency range for which vibration is to be prevented, and the switching operation of the second switching valve 54 is performed in accordance with the second vibration frequency. It is possible to obtain an effective vibration damping effect against vibration.

In addition, the vibration damper 1 structured as described above
In the case of No. 0, since there is no need to incorporate an actuator member such as an electromagnetic driving means into itself, there is a great advantage that the structure is extremely simple, easy to manufacture, lightweight, compact and inexpensive. In addition, since the structure is simple, it has excellent durability and reliability, and has an advantage that it is easy to cope with a failure.

Further, in such a vibration damper 10, since the displacement force of the mass metal fitting 18 is obtained by using the negative pressure, especially in an automobile or the like using an internal combustion engine,
Since the negative pressure generated in the intake system or the like can be advantageously used, there is an advantage that no special driving energy generating means is required. When compressed air can be easily obtained, it is of course possible to displace the mass metal fitting 18 using positive pressure instead of negative pressure.

As described above, one embodiment of the present invention has been described in detail, but this is a literal example.
It should not be construed that the invention is limited only to such an embodiment.

For example, the shape and size of the partition fitting 16, the mass fitting 18, the first and second rubber elastic bodies 20, 22 and the like,
The material and the like are appropriately changed and set according to the magnitude and frequency of vibration to be damped in the vibration damper 10, and are not limited. As a specific example, FIG. 2 shows a vibration damper 62 employing a second rubber elastic body 60 having another shape as a second embodiment. The second rubber elastic body 60 has a tapered cylindrical shape whose diameter gradually increases from the partition fitting 16 toward the mass fitting 18. In the present embodiment, in order to facilitate the understanding, the same reference numerals as those in the first embodiment are used in the drawings for members and portions having the same structure as that of the first embodiment. Keep it. As described above, when the second rubber elastic member 60 having a tapered cylindrical shape is employed, the elastic deformation of the second rubber elastic member 60 in the displacement direction of the mass metal fitting 18 is caused not only by pure compression but also by shear deformation. Therefore, it is possible to set the spring constant of the vibration system of the second rubber elastic body 60 and thus the mass metal fitting 18 to be small, and to increase the spring constant in the direction perpendicular to the vibration direction in which vibration is to be prevented. As a result, it is also possible to reduce the adverse effects and the like caused by the swing of the mass metal fitting 18 in the direction perpendicular to the axis.

In each of the above-described embodiments, the active air damping effect is generated by applying a fluctuating air pressure to the working air chambers 36 and 48 to displace the partition member 16 and the mass metal member 18 to generate an exciting force. I was getting it, but in addition,
It is possible to obtain an effective passive vibration damping effect by using the vibration damper having the structure according to the present invention as a dynamic damper. In that case, for example, by applying a constant negative pressure or positive pressure to the first working air chamber 36 and the second working air chamber 48, the mass metal fitting 18 or the partition metal fitting 16 is used.
The natural frequency of the vibration system can be changed and controlled appropriately by changing the supporting spring constant of the vibration system constituted by This makes it possible to realize a sub-vibration system that can exhibit an excellent vibration absorbing effect.

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.

[0044]

As is apparent from the above description, any of the vibration dampers having the structure according to the first to fourth aspects of the present invention constitutes actuator means for exciting the mass member. The mass member is displaced based on the air pressure exerted from the outside without the need to incorporate the special member inside, and therefore the vibration damper capable of exhibiting the active vibration reduction effect has a simple structure. It can be advantageously realized with a small number of parts.

Further, in such a vibration damper, since two independent working air chambers for exerting a displacement force on the mass member are provided independently, the air pressure applied to these two working air chambers can be controlled independently. By adjusting to, the excitation force exerted on the vibration damping object can be set over a wide range, whereby an effective vibration damping effect can be obtained for vibrations in a plurality of or wide frequency ranges. It is also possible to obtain.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a vibration damper as a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a vibration damper as a second embodiment of the present invention.

[Explanation of symbols]

 10, 62 Vibration suppressor 12 Vibration body 14 Mounting bracket 16 Partition bracket 18 Mass bracket 20 First rubber elastic body 22, 60 Second rubber elastic body 26 First air supply / discharge path 36 First working air chamber 38 Second air supply / discharge path 48 Second working air chamber 52 First switching valve 54 Second switching valve 56 Negative pressure source

Claims (4)

[Claims] An attachment member attached to a vibration damping object, a mass member spaced apart in a direction of input of vibration to be damped with respect to the attachment member, and a space between the attachment member and the mass member In the mounting member and the mass member, a rigid partition member that is disposed apart from each other in the input direction of vibration to be damped, and interposed between the mounting member and the rigid partition member, A first rubber elastic body elastically connecting the two members, a second rubber elastic body interposed between the rigid partition member and the mass member, and elastically connecting the two members; Part of the wall portion is constituted by the first rubber elastic body,
A seal formed between the mounting member and the rigid partition member, the seal member exerting a relative displacement force on the rigid partition member in the input direction of vibration to be damped based on a change in internal pressure. A first working air chamber, a first air supply / discharge path for applying air pressure to the first working air chamber to generate a pressure change, and a wall portion formed by the second rubber elastic body. Partly composed,
A sealing member formed between the rigid partition member and the mass member, and for exerting a relative displacement force on the rigid partition member in an input direction of vibration to be damped against the mass member based on a change in internal pressure; And a second working air chamber for applying air pressure to the second working air chamber to cause the second working air chamber to generate a pressure change independent of the first working air chamber. A vibration damper having two air supply / discharge paths. 2. An air pressure control device which varies air pressures applied to said first working air chamber and said second working air chamber in substantially the same phase in synchronization with the frequency of vibration to be damped. The vibration damper according to claim 1 provided. 3. An air pressure control device for varying the air pressure applied to the first working air chamber and the second working air chamber in synchronization with different vibration frequencies to be damped. 3. The vibration damper according to 1 or 2. 4. An air pressure applied to one of the first working air chamber and the second working air chamber is set and maintained at a substantially constant air pressure. The vibration damper according to any one of claims 1 to 3, further comprising an air pressure control device that varies an air pressure applied to one of the two working air chambers in synchronization with a frequency of vibration to be damped.