JP2008128368A - Vibration control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of cavitation in a main liquid chamber. <P>SOLUTION: An insertion hole 20 larger in opening area than other through holes 23 and opened toward the outer peripheral edge part of a movable plate 18, is included in a plurality of through holes 23 formed in a first partition plate 21, and a radially outer part 20a located at an outer end in the radial direction of the first partition plate 21 is extended along the outer peripheral edge of the movable plate 18 on the inner peripheral surface of the insertion hole 20 and located radially outward from the other through holes 23. When vibration of amplitude with a threshold value or more is applied to an outer cylinder 11 or a mounting member 12 to drop the pressure of liquid in the main liquid chamber 16, the movable plate 18 is brought into close contact with the first partition plate 21 by the pressure difference to close the plurality of through holes 23, and a facing part, facing the insertion hole 20, of the movable plate 18 enters the insertion hole 20 to allow the main liquid chamber 16 and an auxiliary liquid chamber 17 to communicate with each other through the insertion hole 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vibration isolator that is applied to, for example, automobiles and industrial machines and absorbs and attenuates vibrations of a vibration generating unit such as an engine.

As this type of vibration isolator, conventionally, for example, as shown in Patent Document 1 below, an outer cylinder connected to one of a vibration generating part and a vibration receiving part, and an axial end of this outer cylinder A mounting member disposed on the inner side and connected to one of the vibration generating unit and the vibration receiving unit, and the mounting member and the outer cylinder are elastically connected to each other, and an opening at one axial end of the outer cylinder A rubber elastic part that closes the opening, a diaphragm that closes an opening at the other axial end of the outer cylinder, and a liquid-filled space enclosed by the rubber elastic part and the diaphragm inside the outer cylinder, A partition part is provided for partitioning into a main liquid chamber whose elastic part is a part of the partition wall and a sub liquid chamber whose diaphragm is a part of the partition part, and these partition parts are mutually connected in the axial direction of the outer cylinder. Spaced The first and second partition plates, a movable plate housed between these partition plates, an orifice fitted inside the outer cylinder and communicating the main liquid chamber and the sub liquid chamber; There is known a configuration in which a plurality of through holes are formed in the first and second partition plates at positions facing the movable plate, respectively.
JP-A-2005-351350

  However, in the conventional vibration isolator, when the vibration of a large amplitude acts on the outer cylinder or the mounting member and the pressure of the liquid in the main liquid chamber suddenly decreases, the allowable passage flow rate of the liquid in the orifice is insufficient. The change in pressure could not be absorbed, and cavitation occurred in the main liquid chamber, possibly causing abnormal noise.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a vibration isolator capable of preventing cavitation from occurring in the main liquid chamber.

In order to solve the above-described problems and achieve such an object, the vibration isolator of the present invention includes an outer cylinder connected to one of the vibration generating unit and the vibration receiving unit, and the axial direction of the outer cylinder. A mounting member disposed on the inner side of the one end portion and connected to either the vibration generating portion or the vibration receiving portion, and elastically connecting the mounting member and the outer cylinder, and one axial end portion of the outer cylinder A rubber elastic part that closes the opening in the outer cylinder, a diaphragm that closes the opening in the other axial end of the outer cylinder, and a liquid-filled space that is closed by the rubber elastic part and the diaphragm inside the outer cylinder A partition part that divides the main elastic chamber having the rubber elastic part as a part of the partition and a sub liquid chamber having the diaphragm as a part of the partition, the partition part being a shaft of the outer cylinder. Spaced apart from each other in the direction The first and second partition plates, a movable plate housed between these partition plates, an orifice fitted inside the outer cylinder and communicating the main liquid chamber and the sub liquid chamber; The first partition plate is disposed on the main liquid chamber side, and the second partition plate is disposed on the sub liquid chamber side, and each of these partition plates has a plurality of positions at positions facing the movable plate. A vibration isolator having a through hole formed therein, wherein the plurality of through holes formed in the first partition plate have a larger opening area than other through holes and are directed toward an outer peripheral edge of the movable plate. And a radially outer portion located at the radially outer end of the first partition plate extends along the outer peripheral edge of the movable plate. And located outside of the other through hole in the radial direction, the outer cylinder or When the pressure of the liquid in the main liquid chamber drops due to vibration with an amplitude greater than a threshold acting on the mounting member, the pressure difference causes the movable plate to be in close contact with the first partition plate to block the plurality of through holes. In addition, the main liquid chamber and the auxiliary liquid chamber are configured to communicate with each other through the insertion hole by allowing a facing portion of the movable plate facing the insertion hole to enter the insertion hole. To do.
In the present invention, the insertion hole is formed in the first partition plate disposed on the main liquid chamber side, and the vibration of the amplitude greater than the threshold acts on the outer cylinder or the mounting member, so that the pressure of the liquid in the main liquid chamber suddenly increases. When the pressure drops, the main liquid chamber communicates with the sub liquid chamber through the insertion hole by causing the opposing portion facing the insertion hole to enter the insertion hole at the outer peripheral edge of the movable plate. Therefore, when the pressure of the liquid in the main liquid chamber suddenly drops, the liquid in the sub liquid chamber can be sucked into the main liquid chamber not only through the orifice but also through the insertion hole. Thus, cavitation can be prevented from occurring in the main liquid chamber.
Furthermore, since it is not necessary to provide a new valve body in order to achieve such an effect, it is possible to prevent an increase in the manufacturing cost of the vibration isolator.

Here, the radially outward portion of the inner peripheral surface of the insertion hole gradually increases outward in the radial direction of the first partition plate from the surface on which the movable plate is disposed toward the back surface. It may be a first inclined surface extending toward the surface.
In this case, since the radially outer portion of the inner peripheral surface of the insertion hole is the first inclined surface, the movable plate is moved after the outer peripheral edge portion of the movable plate has entered the insertion hole as described above. It is possible to suppress sliding resistance between the outer peripheral edge of the movable plate and the inner peripheral surface of the insertion hole when restoring and deforming. As a result, when the movable plate is restored and deformed, the outer peripheral edge portion can be easily returned between the first and second partition plates, and the anti-vibration performance of the anti-vibration device is always stable. Can be demonstrated.

In addition, the portion of the outer peripheral surface of the movable plate that is connected to the opposing portion on the outer side in the radial direction of the movable plate moves from the surface on the second partition plate side toward the back surface on the first partition plate side in the movable plate. The second inclined surface may be gradually extended outward in the radial direction of the movable plate.
In this case, on the outer peripheral surface of the movable plate, the portion that continues to the opposite portion in the radial direction of the movable plate is the second inclined surface, so that the outer peripheral edge of the movable plate is inserted into the insertion hole as described above. It is possible to suppress the sliding resistance between the outer peripheral edge portion of the movable plate and the inner peripheral surface of the insertion hole when the movable plate is restored and deformed after the portion is entered. As a result, when the movable plate is restored and deformed, the outer peripheral edge portion can be easily returned between the first and second partition plates, and the anti-vibration performance of the anti-vibration device is always stable. Can be demonstrated.

  According to this invention, it is possible to prevent cavitation from occurring in the main liquid chamber.

Hereinafter, an embodiment of a vibration isolator according to the present invention will be described with reference to FIGS. 1 to 3. The vibration isolator 10 is arranged inside the outer cylinder 11 connected to one of the vibration generating part and the vibration receiving part, and at one end portion in the axial direction of the outer cylinder 11, and the vibration generating part and the vibration receiving part An attachment member 12 connected to one of the other, an elastic member 13 that elastically connects the attachment member 12 and the outer cylinder 11, and closes an opening at one axial end of the outer cylinder 11, A diaphragm 14 that closes the opening at the other axial end of the cylinder 11, and a liquid enclosure space that is closed by the rubber elastic part 13 and the diaphragm 14 inside the outer cylinder 11, a main liquid chamber 16 and a secondary liquid described later. And a partition 15 that partitions the chamber 17.
Each of these members is provided coaxially with the central axis O. The liquid enclosure space is filled with, for example, ethylene glycol, water, silicone oil or the like.

 The partition 15 includes first and second partition plates 21 and 22 that are spaced apart from each other in the axial direction of the outer cylinder 11, and a movable plate 18 that is housed between the partition plates 21 and 22. And an orifice 19 that is fitted inside the outer cylinder 11 and communicates with the main liquid chamber 16 and the sub liquid chamber 17. The first partition plate 21 is disposed on the main liquid chamber 16 side, and the second partition plate 22 is disposed on the sub liquid chamber 17 side. The partition plates 21 and 22 are respectively positioned at positions facing the movable plate 18. A plurality of through holes 23 are formed.

Here, the distance between the first and second partition plates 21 and 22 is larger than the thickness of the movable plate 18, and the movable plate 18 changes the pressure of the liquid in the main liquid chamber 16 and the sub liquid chamber 17. Thus, the first and second partition plates 21 and 22 can move about ± 0.5 mm in the direction of the central axis O. In addition, the movable plate 18 is formed in a disk shape with a rubber-like elastic material.
When the vibration isolator 10 is mounted on, for example, an automobile, the attachment member 12 is connected to an engine as a vibration generating unit, while the outer cylinder 11 is connected to a vehicle body as a vibration receiving unit via a bracket (not shown). As a result, transmission of engine vibration to the vehicle body can be suppressed.

The outer cylinder 11 includes a small diameter portion 11a on one end side in the axial direction, a large diameter portion 11b on the other end side in the axial direction, and a step portion 11c that connects the small diameter portion 11a and the large diameter portion 11b. ˜11c are arranged coaxially with the central axis O and are integrally formed.
Further, in the illustrated example, the mounting member 12 is provided with a cylindrical body 12a having an internal thread portion formed on the inner peripheral surface thereof, and projecting outward in the axial direction on the other axial end surface of the cylindrical body 12a. And a wall portion 12b. The cylindrical body 12 a is provided coaxially with the outer cylinder 11 in a state where one end in the axial direction protrudes outward in the axial direction from the opening surface at one axial end of the outer cylinder 11.

The rubber elastic portion 13 includes a portion located inside the outer cylinder 11 in the cylindrical body 12a, a block-shaped main body portion 13a in which the wall portion 12b is embedded, and a radial direction from the outer peripheral side of the cylindrical body 12a. A leg portion 13b that gradually extends toward one end of the outer cylinder 11 toward the outside, and an inner peripheral surface of the outer cylinder 11 from the tip of the leg portion 13b toward the other axial end of the outer cylinder 11 And a covering portion 13c extending along, and these 13a to 13c are integrally formed.
Among these, the tip of the leg portion 13 b is vulcanized and bonded to the inner peripheral surface at one end portion of the outer cylinder 11. Further, the covering portion 13c is vulcanized and bonded to the entire area of the inner peripheral surface of the outer cylinder 11 where the tip of the leg portion 13b is not vulcanized and bonded. Thereby, the inner peripheral surface of the outer cylinder 11 is covered with the tip of the leg portion 13b and the covering portion 13c over the entire area.

  Here, the main liquid chamber 16 has the rubber elastic portion 13 as a part of the partition wall, and its internal volume changes with the deformation of the rubber elastic portion 13, and the sub liquid chamber 17 has the diaphragm 14 as a part of the partition wall. The internal volume changes according to the pressure change of the sealed liquid.

  The orifice 19 of the partition portion 15 is a ring-shaped body, and in this embodiment, the orifice 19 is fitted to the surface of the covering portion 13c that covers the portion that continues to the step portion 11c on the inner peripheral surface of the large diameter portion 11b of the outer cylinder 11. Yes. The orifice 19 has an orifice passage 19a extending in the circumferential direction on the outer peripheral surface thereof, a first passage 19b for communicating the orifice passage 19a and the main liquid chamber 16, and an orifice passage 19a and a sub-liquid. A second passage 19c that communicates with the chamber 17 is formed, and the main liquid chamber 16 and the sub liquid chamber 17 communicate with each other through the orifice passage 19a, the first passage 19b, and the second passage 19c.

Here, the first partition plate 21 is extended along the radial direction at the inner peripheral surface of the ring-shaped orifice 19 at the end on the side of the secondary liquid chamber 17 so as to close the opening surface. The first partition plate 21 and the orifice 19 are integrally formed of, for example, a metal material. The second partition plate 22 includes a top plate portion 22a that is circular when viewed from above, a peripheral wall portion 22b that is suspended from the outer periphery of the top plate portion 22a, and radially outward from the opening edge of the peripheral wall portion 22b. And a flange-like portion 22c provided so as to be integrally formed with, for example, a metal material. The top plate portion 22a and the peripheral wall portion 22b of the second partition plate 22 are flanged so as to protrude from the opening end surface on the side of the secondary liquid chamber 17 toward the inside of the secondary liquid chamber 17 in the ring-shaped orifice 19. The shape portion 22 c is disposed on the opening end surface of the orifice 19 on the side of the secondary liquid chamber 17.
As described above, the movable plate 18 is housed in a space surrounded by the first partition plate 21, the top plate portion 22 a of the second partition plate 22, and the peripheral wall portion 22 b of the second partition plate 22, and the second partition plate The movement of the creeping direction and the movement around the central axis O are restricted by the inner circumferential surface of the peripheral wall portion 22b of the 22.

  In the present embodiment, the plurality of through holes 23 formed in the first partition plate 21 have an opening area larger than that of the other through holes 23 as shown in FIG. An insertion hole 20 opened toward the peripheral edge is provided. On the inner peripheral surface of the insertion hole 20, the radially outer portion 20 a located at the outer end in the radial direction of the first partition plate 21 extends along the outer peripheral edge of the movable plate 18 and other penetrations It is located outside the hole 23 in the radial direction of the first partition plate 21.

  In the illustrated example, the insertion hole 20 has a larger opening area than the plurality of through holes 23 formed in the second partition plate 22, and is formed in the first partition plate 21. In addition, the insertion hole 20 is formed in a generally fan shape in a bottom view of the first partition plate 21, and the three top portions forming the sector shape are formed in a convex curved shape toward the radially outer side of the insertion hole 20. ing. Further, the circumferential length of the radially outer portion 20 a of the insertion hole 20 is, for example, about one quarter of the circumferential length of the movable plate 18.

  In the present embodiment, the radially outer portion 20a of the inner peripheral surface of the insertion hole 20 extends from the front surface 21a where the movable plate 18 is disposed in the first partition plate 21, as shown in FIG. The first inclined surface gradually extends outward in the radial direction of the first partition plate 21 toward 21b. In the example shown in the drawing, this inclined surface and the opening edge 20b of the radially outer portion 20a on the surface 21a of the first partition plate 21 each have a convex curved shape toward the radially inner side of the insertion hole 20. Is formed.

  Furthermore, in the present embodiment, the portion of the outer peripheral surface of the movable plate 18 that enters the insertion hole 20 as described later is located on the first partition plate 21 side from the surface 18a on the second partition plate 22 side of the movable plate 18. The second inclined surface gradually extends outward in the radial direction of the movable plate 18 toward the rear surface 18b. In the illustrated example, the entire outer periphery of the movable plate 18 is the second inclined surface. Further, the inclined surface and the outer peripheral edge 18 c on the back surface 18 b of the movable plate 18 are each formed in a curved surface shape that is convex outward in the radial direction of the movable plate 18.

  In the above configuration, the outer peripheral edge 18c of the movable plate 18 is more radially outward than the opening edge 20b on the surface 21a of the first partition plate 21, and the radially outer portion 20a and the first partition plate. It arrange | positions radially inner side rather than the connection part 21c with the back surface 21b of 21. FIG.

  As described above, when the vibration having a minute amplitude (for example, ± 0.5 mm or less) acts on the outer cylinder 11 or the mounting member 12 and the pressure of the liquid in the main liquid chamber 16 changes, the movable plate 18 is moved to the first position. The first and second partition plates 21 and 22 are vibrated in the direction of the central axis O to open and close the through hole 23, the storage space between the first and second partition plates 21 and 22, and the main liquid The rubber elastic portion 13 is vibrated while the chamber 16 and the auxiliary liquid chamber 17 are in communication, and this vibration is absorbed and attenuated.

  Further, when vibration having an amplitude larger than the minute amplitude and smaller than a threshold value (for example, ± 3 mm) is applied to the outer cylinder 11 or the mounting member 12, and the pressure of the liquid in the main liquid chamber 16 changes, the outer cylinder 11 or the mounting member 12 is movable. The plate 18 is in close contact with the surface 21 a of the first partition plate 21 or the top plate portion 22 a of the second partition plate 22 and closes the through hole 23. As a result, the communication between the main liquid chamber 16 and the sub liquid chamber 17 through the storage space is maintained, and the liquid is passed between the main liquid chamber 16 and the sub liquid chamber 17 only through the orifice 19. This vibration is absorbed and damped by being circulated.

 Further, when vibration having an amplitude equal to or greater than the threshold value acts on the outer cylinder 11 or the attachment member 12 and the pressure of the liquid in the main liquid chamber 16 suddenly decreases, the pressure difference causes the movable plate 18 to move. By close contact with the surface 21 a of the first partition plate 21 and closing the through hole 23 of the first partition plate 21, the opposing portion of the movable plate 18 that faces the insertion hole 20 enters the insertion hole 20. The liquid in the main liquid chamber 16 is sucked into the main liquid chamber 16 from the sub liquid chamber 17 through the insertion hole 20 by communicating the main liquid chamber 16 and the sub liquid chamber 17 through the insertion hole 20. Absorbs a rapid pressure drop.

As described above, according to the vibration isolator 10 according to the present embodiment, the insertion hole 20 is formed in the first partition plate 21 arranged on the main liquid chamber 16 side, and the outer cylinder 11 or the attachment member 12 has a threshold value or more. When the pressure of the liquid in the main liquid chamber 16 suddenly decreases due to the vibration of the amplitude of, an opposing portion facing the insertion hole 20 at the outer peripheral edge of the movable plate 18 enters the insertion hole 20. Thus, the main liquid chamber 16 and the sub liquid chamber 17 are configured to communicate with each other through the insertion hole 20, so that when the pressure of the liquid in the main liquid chamber 16 suddenly decreases, The liquid can be sucked into the main liquid chamber 16 not only through the orifice 19 but also through the insertion hole 20, and cavitation can be prevented from occurring in the main liquid chamber 16.
Furthermore, since it is not necessary to provide a new valve body in order to achieve such effects, it is possible to prevent an increase in the manufacturing cost of the vibration isolator 10.

  Moreover, in this embodiment, since the said radial direction outer part 20a in the internal peripheral surface of the insertion hole 20 becomes the said 1st inclined surface, the outer peripheral edge part of the movable plate 18 in the insertion hole 20 as mentioned above. It is possible to suppress the sliding resistance between the outer peripheral edge portion of the movable plate 18 and the inner peripheral surface of the insertion hole 20 when the movable plate 18 is restored and deformed. Thereby, when the movable plate 18 is restored and deformed, the outer peripheral edge portion can be easily returned between the first and second partition plates 21 and 22, and the vibration isolation device 10 Performance can always be demonstrated stably.

 Furthermore, in the present embodiment, on the outer peripheral surface of the movable plate 18, the portion that continues to the opposed portion on the radially outer side of the movable plate 18 is the second inclined surface. The sliding resistance between the outer peripheral edge portion of the movable plate 18 and the inner peripheral surface of the insertion hole 20 when the movable plate 18 is restored and deformed after the outer peripheral edge portion of the movable plate 18 enters the inside is suppressed. It becomes possible. Thereby, when the movable plate 18 is restored and deformed, the outer peripheral edge portion can be easily returned between the first and second partition plates 21 and 22, and the vibration isolation device 10 Performance can always be demonstrated stably.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the embodiment, one insertion hole 20 is formed, but the number thereof may be any. Moreover, although the fan shape was shown by the bottom view of the 1st partition plate 21 as the insertion hole 20, the shape may be any. Furthermore, the form of the 1st partition plate 21 and the 2nd partition plate 22 is not restricted to the said embodiment, The space which can accommodate the movable board 18 between these 1st, 2nd partition plates 21 and 22 is obtained. Any may be used.

In addition, the second inclined surface is formed over the entire circumference of the movable plate 18. However, the second inclined surface may be formed on the outer circumferential surface of the movable plate 18 at least at a portion connected to the opposed portion at the radially outer side of the movable plate 18.
Further, the first and second inclined surfaces have been configured to have convex curved surfaces as described above, but instead of this, for example, they may be linearly extending planes, or these first and second inclined surfaces may be formed. 1. The second inclined surface may not be formed.

  Cavitation can be prevented from occurring in the main liquid chamber.

It is a longitudinal cross-sectional view of the vibration isolator shown as one Embodiment which concerns on this invention. It is a bottom view of the partition part shown in FIG. FIG. 3 is a partially enlarged longitudinal sectional view of a partition portion shown in FIGS. 1 and 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Anti-vibration apparatus 11 Outer cylinder 12 Mounting member 13 Rubber elastic part 14 Diaphragm 15 Partition part 16 Main liquid chamber 17 Sub liquid chamber 18 Movable plate 18a Movable plate surface 18b Movable plate back surface 19 Orifice 20 Insertion hole 20a Radially outward Part 21 First partition plate 21a Front surface of first partition plate 21b Back surface of first partition plate 22 Second partition plate 23 Through hole

Claims (3)

An outer cylinder coupled to one of the vibration generator and the vibration receiver;
A mounting member that is disposed on the inner side in one axial end portion of the outer cylinder and connected to either the vibration generating portion or the vibration receiving portion;
A rubber elastic portion that elastically connects the mounting member and the outer cylinder, and closes an opening at one axial end of the outer cylinder;
A diaphragm for closing the opening at the other axial end of the outer cylinder;
Inside the outer cylinder, a liquid sealed space closed by the rubber elastic portion and the diaphragm, a main liquid chamber having the rubber elastic portion as a part of the partition, and a sub liquid chamber having the diaphragm as a part of the partition And a partition part for partitioning,
The partition portion is fitted into the first and second partition plates arranged at an interval in the axial direction of the outer cylinder, a movable plate accommodated between the partition plates, and the inner side of the outer cylinder. And an orifice for communicating the main liquid chamber and the sub liquid chamber,
The first partition plate is disposed on the main liquid chamber side, the second partition plate is disposed on the sub liquid chamber side, and each of the partition plates has a plurality of through holes at positions facing the movable plate. An anti-vibration device formed,
The plurality of through holes formed in the first partition plate are provided with insertion holes that have a larger opening area than the other through holes and open toward the outer peripheral edge of the movable plate,
On the inner peripheral surface of the insertion hole, a radially outer portion located at an outer end in the radial direction of the first partition plate extends along the outer peripheral edge of the movable plate, and the other through hole. Is located more outward in the radial direction than
When a vibration having an amplitude greater than or equal to a threshold value acts on the outer cylinder or the mounting member and the pressure of the liquid in the main liquid chamber decreases, the pressure difference causes the movable plate to be in close contact with the first partition plate. The through hole is closed, and the main liquid chamber and the sub liquid chamber are communicated with each other through the insertion hole by allowing a portion of the movable plate facing the insertion hole to enter the insertion hole. An anti-vibration device characterized by that. The vibration isolator according to claim 1,
The radially outer portion of the inner peripheral surface of the insertion hole gradually toward the radially outer side of the first partition plate as it goes from the front surface on which the movable plate is disposed to the back surface of the first partition plate. An anti-vibration device characterized in that the first inclined surface extends. The vibration isolator according to claim 1 or 2,
In the outer peripheral surface of the movable plate, the portion that is continuous with the opposing portion in the radially outward direction of the movable plate gradually increases from the surface on the second partition plate side to the back surface on the first partition plate side in the movable plate. An anti-vibration device characterized in that the second inclined surface extends outward in the radial direction of the movable plate.

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