JP2010276190A - Vibration control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To vary a resonance frequency in a restricting passage in response to input vibration, without using an actuator and a control means. <P>SOLUTION: A partition member 5 is provided with a fixed member 50 having a cylindrical cylinder part 52 and a cover part 53 and a movable member 51 having a piston part 62. The cover part 53 is provided with a communicating hole 59b for communicating the inside of the cylinder part 52 with a main liquid chamber 7 and a check valve 61 for opening-closing the communicating hole 59b. The restricting passage 15 is defined by a fixed wall surface 55a formed in the fixing member 50 and a moving wall surface 67a formed in the movable member 51 and oppositely arranged to the fixed wall surface 55a. Among a cross-sectional shape and the flow passage length of the restricting passage 15, at least one changes, and the resonance frequency of the restricting passage 15 changes. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid-filled vibration isolator that is used when, for example, a vibration generating unit such as an automobile engine is mounted on a vibration receiving unit such as a vehicle body.

  Conventionally, as this type of vibration isolator, a cylindrical first mounting member connected to any one of the vibration generating unit and the vibration receiving unit, and any one of the vibration generating unit and the vibration receiving unit. A second mounting member to be connected, an elastic body that elastically connects the first mounting member and the second mounting member and closes one opening end of the first mounting member, and the other opening of the first mounting member A configuration including a diaphragm that closes the end and a partition member that divides a liquid chamber formed inside the first mounting member into a main liquid chamber and a sub liquid chamber is generally known.

  The above-described main liquid chamber is a liquid chamber in which a part of the partition wall is formed of an elastic body and the internal volume changes due to deformation of the elastic body. The above-described sub liquid chamber is a part of the partition wall formed of a diaphragm. It is a liquid chamber. Further, the above-described partition member is formed with a restriction passage that communicates the main liquid chamber and the sub liquid chamber. This restriction passage is a liquid flow channel that is tuned so that liquid column resonance occurs when the liquid in the liquid chamber flows when vibration of a specific frequency is input, and has a specific resonance frequency. Yes.

In the above-described conventional vibration isolator, when vibration of a specific frequency is input, the spring constant of the vibration isolator decreases due to the liquid column resonance action in the restriction passage, and the input vibration can be attenuated.
However, in the vibration isolator having the above configuration, when the frequency of the input vibration is other than the resonance frequency of the restriction passage, the spring constant of the vibration isolator becomes high. In particular, when the input vibration is a vibration on a higher frequency side than the resonance frequency of the restriction passage, the restriction passage is clogged and the spring constant of the vibration isolator becomes high.

Therefore, conventionally, as shown in Patent Document 1 below, for example, a vibration isolator capable of changing the resonance frequency of the restriction passage has been proposed. In this vibration isolator, an internal pressure absorbing film is provided on a part of the peripheral wall portion of the restriction passage, and a pressing member pressed against the internal pressure absorbing film is provided. This pressing member can be driven forward and backward by an actuator such as a solenoid disposed outside the first mounting member.
In the vibration isolator having the above-described configuration, the tension of the internal pressure absorbing film can be adjusted by moving the pressing member back and forth with the actuator. Thereby, the resonance frequency in the restriction passage can be varied, so that liquid column resonance can be caused in the restriction passage with respect to input vibration in a wide frequency range, and the vibration can be attenuated.

JP 2004-324837 A

  However, in the above conventional vibration isolator, since the actuator is provided outside the first mounting member, it is necessary to secure an installation space for the actuator, and there is a problem of cost increase due to the actuator. Furthermore, in the conventional vibration isolator described above, there is a problem that the actuator must be controlled so that the resonance frequency of the restriction passage becomes a frequency corresponding to the frequency of the input vibration, and complicated control means are required. To do.

  The present invention has been made in consideration of the above-described conventional problems, and provides a vibration isolator capable of varying the resonance frequency in the restriction passage according to the input vibration without using an actuator or a control means. The purpose of this is to reduce vibrations in the frequency range, and to save space and reduce costs.

  The vibration isolator according to the present invention includes a cylindrical first mounting member coupled to one of the vibration generating unit and the vibration receiving unit, a second mounting member coupled to the other, and the first mounting. An elastic body that elastically connects the member and the second mounting member; a liquid chamber in the first mounting member; a main liquid chamber on one side and a secondary liquid on the other side, the elastic body being part of the wall surface A partition member that divides the chamber into a chamber, and the partition member communicates with the main liquid chamber and the sub liquid chamber and forms a restriction passage that causes liquid column resonance when the liquid in the liquid chamber flows. In the liquid-sealed vibration isolator, the partition member is fixed to the inside of the first mounting member, and is provided at a cylindrical cylinder portion and an end portion of the cylinder portion on the main liquid chamber side. A fixing member having a lid portion arranged on the inside of the cylinder portion and opposed to the lid portion. A movable member having a piston portion, and the lid portion is provided with a communication hole that communicates the inside of the cylinder portion and the main liquid chamber, and a check valve that opens and closes the communication hole. The restriction passage is defined by a fixed wall surface formed on the fixed member and a movable wall surface formed on the movable member and opposed to the fixed wall surface. It is characterized in that at least one of the flow path lengths changes to change the resonance frequency of the restriction passage.

With such a feature, when vibration is input from the vibration generating unit to the vibration isolator, the elastic body is elastically deformed along with the vibration input. At this time, if the frequency of the input vibration matches the resonance frequency of the restriction passage, the liquid in the liquid chamber flows through the restriction passage, and the spring constant of the vibration isolator decreases due to the liquid column resonance in the restriction passage. The input vibration is attenuated.
On the other hand, the hydraulic pressure of the main liquid chamber fluctuates with the elastic deformation of the elastic body, and the check valve is opened with the fluctuation of the hydraulic pressure of the main liquid chamber. That is, for example, when the check valve is a positive pressure valve, the check valve is opened when the hydraulic pressure in the main fluid chamber rises and becomes higher than the internal pressure of the cylinder portion. On the other hand, when the check valve is a negative pressure valve, the check valve is opened when the hydraulic pressure in the main fluid chamber decreases and becomes lower than the internal pressure of the cylinder portion. As a result, the inside of the cylinder portion and the main fluid chamber communicate with each other through the communication hole, and the fluid pressure inside the cylinder portion varies according to the fluid pressure variation in the main fluid chamber. In other words, the fluid pressure inside the cylinder is the maximum absolute value of the fluid pressure in the main fluid chamber that fluctuates, that is, the maximum positive pressure value in the main fluid chamber for positive pressure valves, and the main fluid chamber for negative pressure valves. It becomes equal to the most negative pressure value at. As a result, the movable member moves relative to the fixed member while the piston portion slides along the inner peripheral surface of the cylinder portion due to the hydraulic pressure inside the cylinder portion, and the movable wall surface of the movable member and the fixed wall surface of the fixed member And the resonance frequency of the restriction passage changes by changing at least one of the cross-sectional shape and the flow path length of the restriction passage formed by the fixed wall surface and the moving wall surface. In such a vibration isolator using liquid column resonance, the frequency at which the fluid pressure fluctuation is maximized is generally higher than the frequency at which the vibration transmissibility is minimized. Therefore, after the vibration transmissibility is minimized in the process of increasing the frequency, the liquid flows in the restricted passage by adjusting the reaction force of the spring so that the piston part just starts moving at the hydraulic pressure that starts to increase again. The spring constant of the vibration isolator is lowered by liquid column resonance in the limit passage, and the input vibration is attenuated.

  In the vibration isolator according to the present invention, it is preferable that the fixed wall surface and the moving wall surface are inclined with respect to the moving direction of the movable member.

  As a result, when the movable member moves relative to the fixed member while the piston portion slides along the inner peripheral surface of the cylinder portion due to the hydraulic pressure inside the cylinder portion, the cross-sectional shape of the restriction passage increases and the flow is increased. The road length becomes shorter. Therefore, the variation width of the resonance frequency of the restriction passage with respect to the stroke of the movable member is increased.

  In the vibration isolator according to the present invention, the restriction passage serves as a first restriction passage in which liquid column resonance occurs with respect to any one of input vibrations in different frequency ranges, and the sub-passage A first sub liquid chamber communicated with the main liquid chamber via the first restricting passage in which a liquid column resonance occurs with respect to an input vibration of any one of input vibrations in different frequency ranges; A second fluid communicated with the main liquid chamber via a second restriction passage in which liquid column resonance occurs with respect to any one of the input vibrations in different frequency ranges due to the flow of the liquid in the liquid chamber. And a secondary liquid chamber.

  As a result, when any one of the input vibrations in different frequency ranges is input, the liquid in the liquid chamber flows in the first restriction passage, and the liquid column resonance in the first restriction passage causes Vibration is damped. On the other hand, when either one of the input vibrations in different frequency ranges is input, the liquid in the liquid chamber flows through the second restriction passage and vibrates due to liquid column resonance in the second restriction passage. Is attenuated.

  According to the vibration isolator of the present invention, the resonance frequency in the restricted passage can be varied according to the input vibration without using an actuator or a control means, and vibrations in a wide frequency range can be attenuated. , Space saving and cost reduction can be achieved.

It is sectional drawing of the vibration isolator for demonstrating embodiment of this invention. It is a perspective view of an orifice member (constituent member of the first attachment member) for explaining an embodiment of the present invention. It is a perspective view of a cylinder part for explaining an embodiment of the invention. It is a perspective view of a movable member for explaining an embodiment of the invention. It is a perspective view of the bottom for explaining an embodiment of the invention. It is sectional drawing of the partition member for demonstrating embodiment of this invention. It is sectional drawing of the partition member for demonstrating embodiment of this invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a vibration isolator according to the present invention will be described with reference to the drawings.
In addition, the code | symbol O shown in FIG. 1 has shown the center axis line of the vibration isolator 1, and is only described as "the axis line O" below. A direction along the axis O is referred to as an “axial direction”, a direction perpendicular to the axis O is referred to as a “radial direction”, and a direction around the axis O is referred to as a “circumferential direction”.
Further, the lower side in FIG. 1 is a bounce side to which a static load (initial load) is input when the vibration isolator 1 is installed, and the upper side in FIG. 1 is a rebound side opposite to the input direction of the static load. In the following description, the bound side is “down” and the rebound side is “up”.

  First, the structure of the vibration isolator 1 in this Embodiment is demonstrated.

  As shown in FIG. 1, the vibration isolator 1 is an engine mount that supports an engine that is a vibration generating unit in an automobile to a vehicle body that is a vibration receiving unit. The vibration isolator 1 includes a cylindrical first attachment member 2 connected to a vehicle body (not shown), and a second attachment member disposed above the first attachment member 2 and connected to an engine (not shown). 3, an elastic body 4 that elastically connects the first and second mounting members 2, 3, and a partition member 5 disposed in the first mounting member 2. A liquid chamber 6 is formed inside one mounting member 2.

  The liquid chamber 6 is hermetically sealed by the elastic body 4 and a diaphragm 10 described later, and a liquid such as ethylene glycol or water is enclosed. The liquid chamber 6 is divided into an upper main liquid chamber 7 and lower sub liquid chambers 8 and 9 by a partition member 5 disposed inside the first mounting member 2. The main liquid chamber 7 is a liquid chamber formed with the elastic body 4 as a part of the partition wall, and the internal volume changes due to the deformation of the elastic body 13. The sub liquid chambers 8 and 9 are formed inside an orifice member 21 to be described later, and are defined below the first sub liquid chamber 8 and the first sub liquid chamber 8 partitioned by using the partition member 5 as a part of the partition wall. And a second sub-liquid chamber 9 which is formed and has a diaphragm 10 which will be described later as a part of the partition wall. The internal volume of the first secondary liquid chamber 8 changes due to the raising and lowering of a piston portion 62 described later, and the internal volume of the second secondary liquid chamber 9 changes due to the deformation of the diaphragm 10. The first sub-liquid chamber 8 is communicated with the main liquid chamber 7 or the second sub-liquid chamber 9 by leak means (not shown), and the liquid pressure in the first sub-liquid chamber 8 is changed to the main liquid chamber 7 or When the pressure becomes higher than that of the second sub liquid chamber 9, the liquid pressure in the first sub liquid chamber 8 is gradually released. As the above-described leakage means, for example, a minute hole formed in a cylinder portion 52, a lid portion 53, a piston portion 62, etc., which will be described later, or a clearance between the piston portion 62 and the cylinder portion 52 in a sliding contact portion may be used. Or the clearance gap of the fitting part of the cylinder part 52 and the cover part 53 etc. may be sufficient.

  The first mounting member 2 includes an outer cylinder 20 that extends in the axial direction about the axis O, and a cylindrical orifice member 21 that is disposed inside the outer cylinder 20. The outer cylinder 20 is a cylinder part that can be divided into an upper outer cylinder part 22 and a lower outer cylinder part 23.

  The upper outer cylinder part 22 is a cylinder part that constitutes the upper part of the outer cylinder 20, and the elastic body 4 is joined thereto. As a schematic configuration of the upper outer cylindrical portion 22, a cylindrical peripheral wall portion 24, an upper flange portion 25 provided at the upper end of the peripheral wall portion 24, and a lower flange portion 26 provided at the lower end of the peripheral wall portion 24, I have. The upper flange portion 25 is a plate portion that protrudes radially outward from the upper end of the peripheral wall portion 24, and is formed over the entire periphery of the peripheral wall portion 24. The lower flange portion 26 is a plate portion that protrudes radially outward from the lower end of the peripheral wall portion 24, and is formed over the entire periphery of the peripheral wall portion 24. The upper flange portion 25 and the lower flange portion 26 are vertically opposed to each other, and vertical ribs 22 a protruding from the outer peripheral surface of the peripheral wall portion 24 are arranged between the upper flange portion 25 and the lower flange portion 26. It is installed. The upper and lower ends of the vertical rib 22a are connected to the upper flange portion 25 and the lower flange portion 26, respectively, and a plurality of the vertical ribs 22a are arranged at intervals in the circumferential direction.

  The lower outer cylinder part 23 is a cylinder part constituting the lower part of the outer cylinder 20, and is connected in series below the upper outer cylinder part 22 with the axis O as a common axis. The schematic configuration of the lower outer cylinder portion 23 includes a cylindrical peripheral wall portion 27, a flange portion 28 provided at the upper end of the peripheral wall portion 27, and a bracket portion 29 provided at the lower end of the peripheral wall portion 27. ing. The peripheral wall part 27 of the lower outer cylinder part 23 is a cylindrical cylinder part similar to the peripheral wall part 24 of the upper outer cylinder part 22, and the inner diameter of the peripheral wall part 27 of the lower outer cylinder part 23 is the upper outer cylinder part. 22 has the same diameter as the inner diameter of the peripheral wall 24. The flange portion 28 is a plate portion that protrudes radially outward from the upper end of the peripheral wall portion 27, and is formed over the entire periphery of the peripheral wall portion 27. The flange portion 28 is overlapped and bolted to the lower flange portion 26 of the upper outer cylinder portion 22 described above, whereby the upper outer cylinder portion 22 and the lower outer cylinder portion 23 are connected. Further, on the upper surface of the inner peripheral portion of the flange portion 28, a stepped portion 28 a that is recessed stepwise extends along the inner edge of the flange portion 28 over the entire circumference. The bracket portion 29 is a substantially L-shaped plate portion in cross-section, and protrudes from the outer peripheral surface of the peripheral wall portion 27 and is suspended from the lower surface of the flange portion 28. The bracket portion 29 is provided with a leg portion 29a protruding outward in the radial direction, and the leg portion 29a is connected to a vehicle body (not shown).

  A diaphragm 10 that closes the lower opening of the outer cylinder 20 is provided at the lower end of the outer cylinder 20 described above. The diaphragm 10 is a bowl-like rubber film joined to the lower end portion of the lower outer cylinder portion 23, and the outer edge portion thereof is vulcanized and bonded to the lower end portion of the lower outer cylinder portion 23. A rubber film 11 covering the inner peripheral surface of the peripheral wall portion 24 of the lower outer cylinder portion 23 is integrally formed on the outer edge portion of the diaphragm 10. The rubber film 11 is extended to the surface of the stepped portion 28a. In addition, the diaphragm 10 can also use the elastic body which consists of synthetic resins etc. besides rubber | gum.

  The orifice member 21 is an annular member disposed coaxially with the outer cylinder 20 with the axis O as a common axis, and is disposed between the elastic body 4 and the diaphragm 10. As shown in FIG. 2, a circumferential groove 21a extending in the circumferential direction is formed on the outer peripheral surface of the orifice member 21, and as shown in FIG. By being blocked by the peripheral wall portion 27 (rubber film 11) of the side outer cylinder portion 23, a low frequency orifice 12 (second restriction passage) that connects the main liquid chamber 7 and the second sub liquid chamber 9 is formed. Yes.

  More specifically, as shown in FIG. 2, the orifice member 21 includes a cylindrical cylindrical portion 21b extending in the axial direction and an upper wall of the low frequency orifice 12 protruding radially outward from the upper end of the cylindrical portion 21b. A lower wall portion 21d of the low frequency orifice 12 that protrudes radially outward from the outer peripheral surface of the cylindrical portion 21b and is spaced below the upper wall portion 21c, and an upper wall portion 21c. And a plurality of support wall portions 21e arranged at intervals in the circumferential direction. The upper wall portion 21c has a larger diameter than the lower wall portion 21d, and protrudes outward in the radial direction over the entire circumference. As shown in FIG. 1, the outer peripheral portion of the upper wall portion 21 c is placed on the step portion 28 a of the lower outer cylinder portion 23, and the lower flange portion 26 of the step portion 28 a and the upper outer cylinder portion 22. Is sandwiched between. Thereby, the orifice member 21 is supported inside the outer cylinder 20.

  The low-frequency orifice 12 described above is a liquid flow path formed by the cylindrical portion 21b, the upper wall portion 21c, the lower wall portion 21d, and the peripheral wall portion 27 (rubber film 11) of the lower outer cylindrical portion 23. The outer cylinder 20 extends along the circumferential direction. The low frequency orifice 12 is liquid column resonance (resonance phenomenon) in the liquid flowing through the low frequency orifice 12 when vibration in a low frequency range (for example, 8 Hz to 15 Hz) such as shake vibration is input to the vibration isolator 1. ) To dampen the vibration, and is tuned so that liquid column resonance occurs with respect to the low-frequency vibration in the vehicle. Further, as shown in FIG. 2, the wall surfaces 12a and 12b at both ends of the low frequency orifice 12 in the flow path length direction are inclined in the flow path length direction (circumferential direction). More specifically, the wall surface 12a on one end side in the channel length direction is inclined downward from one end side in the channel length direction toward the other end side, and the wall surface 12b on the other end side in the channel length direction. Is inclined downward from one end side to the other end side in the flow path length direction.

  Further, the orifice member 21 is formed with a main liquid chamber side opening 13 for communicating one end of the low frequency orifice 12 in the flow path length direction and the main liquid chamber 7 shown in FIG. A sub liquid chamber side opening 14 is formed to communicate the other end portion of the 12 flow path length direction and the second sub liquid chamber 9. The main liquid chamber side opening 13 is formed in the upper wall portion 21c and the cylinder portion 21b of the orifice member 21, and the inner edge of the upper portion of the orifice member 21 extends from the radial intermediate portion of the upper wall portion 21c to the lower wall portion 21d. The upper wall portion 21c and the cylindrical portion 21b are cut out from the upper surface. The auxiliary liquid chamber side opening 14 is formed in the lower wall portion 21d of the orifice member 21 and has a shape obtained by cutting off the end portion of the lower wall portion 21d on the other end side in the flow path length direction of the low frequency orifice 12. is doing.

  As shown in FIG. 1, the second mounting member 3 is a mounting member connected to the engine via an engine bracket (not shown), and is disposed on the upper side in the axial direction of the first mounting member 2 and has an axis O. Is arranged around the center. As a schematic configuration of the second mounting member 3, a substantially truncated cone-shaped anchor portion 30 that is gradually reduced in diameter as it goes downward, and a plate-shaped joint portion 31 that is erected on the upper surface of the anchor portion 30 are provided. ing.

  The elastic body 4 is a rubber body that closes the upper opening of the outer cylinder 20, and has an outer peripheral surface that has a mountain shape with a gradually reduced diameter and a lower surface that is recessed. Yes. The lower portion of the elastic body 4 is vulcanized and bonded to the upper inner peripheral surface of the peripheral wall portion 24 of the upper outer cylinder portion 22 and the upper surface of the inner peripheral portion of the upper flange portion 25. On the other hand, the upper portion of the elastic body 4 is vulcanized and bonded to the outer peripheral surface and the lower surface of the anchor portion 30 of the second mounting member 3. A rubber film 40 that covers the inner peripheral surface of the peripheral wall 24 of the upper outer cylinder 22 is integrally formed at the lower end of the elastic body 4. The rubber film 40 is formed under the upper outer cylinder 22. It extends to the lower surface of the flange portion 26. In addition, as the elastic body 4, it is also possible to use an elastic body made of synthetic resin or the like in addition to rubber.

The partition member 5 includes a fixed member 50 fixed to the first mounting member 2 and a movable member 51 provided to be movable with respect to the fixed member 50, and a high-frequency orifice 15 described later is formed. ing.
The fixing member 50 includes a cylinder portion 52 having a top shape and a lid portion 53 provided at an end portion of the cylinder portion 52 on the main liquid chamber 7 side (upper side).

  As shown in FIGS. 1 and 3, the cylinder portion 52 includes a top wall portion 54 disposed perpendicular to the axis O, and a cylindrical peripheral wall portion 55 suspended from the lower surface of the outer peripheral portion of the top wall portion 54. A rising wall portion 56 erected on the upper surface of the outer peripheral portion of the ceiling wall portion 54, a support portion 57 protruding radially outward from the outer edge of the ceiling wall portion 54, and a lower surface of the central portion of the ceiling wall portion 54 And a cylindrical bearing portion 58 that is suspended from the bottom.

The top wall portion 54 is a plate portion having a circular shape in plan view, and a shaft through hole 54a communicating with the bearing portion 58 is formed at the center, and a plurality of communication holes 54b are formed around the shaft through hole 54a. It is formed at intervals in the direction.
The rising wall portion 56 is a cylindrical wall portion to which the lid portion 53 is attached. The bearing portion 58 is a cylindrical tube portion through which a shaft member 17 described later is inserted to support the upper portion of the shaft member 17. The rising wall portion 56 and the bearing portion 58 are each a cylindrical tube portion extending with the axis O as the central axis, and the plurality of communication holes 54b described above are arranged inside the rising wall portion 56 in plan view. It is installed.

The peripheral wall portion 55 is a cylindrical portion disposed coaxially with the bearing portion 58 with the axis O as a common axis. The inner peripheral surface of the peripheral wall portion 55 has a straight cylindrical shape with the same diameter over the entire axial direction. On the other hand, the outer peripheral surface (fixed wall surface 55a) of the peripheral wall portion 55 has a tapered shape that is gradually reduced in diameter as it goes downward, and is inclined with respect to the axial direction.
The support portion 57 is a plate portion that is placed on the upper surface of the support wall portion 21e of the orifice member 21 and is fixed with screws or the like. The support portion 57 protrudes from the outer edge of the top wall portion 54 in a substantially convex shape and has a peripheral shape. A plurality are arranged at intervals in the direction.

  As shown in FIG. 1, the lid portion 53 is a lid body that is attached to the rising wall portion 56 described above, and is disposed so as to face the main liquid chamber 7. As a schematic configuration of the lid portion 53, a top wall portion 59 disposed perpendicular to the axis O and a peripheral wall portion 60 suspended from the outer edge of the top wall portion 59 are provided.

The top wall portion 59 is a circular plate portion in plan view having a diameter larger than the outer diameter of the rising wall portion 56, and is disposed above the rising wall portion 56. The ceiling wall 59 has a plurality of insertion holes 59a through which convex portions 61a of a check valve 61, which will be described later, are inserted, and a plurality of cylinders 52 (inside the rising wall 56) and the main liquid chamber 7 communicating with each other. A communication hole 59b is formed. The insertion hole 59a is disposed in the central portion of the top wall portion 59, and the plurality of communication holes 59b are disposed around the insertion hole 59a at intervals in the circumferential direction.
The peripheral wall portion 60 is a cylindrical portion that is fitted to the outer periphery of the rising wall portion 56, and the peripheral wall portion 60 and the rising wall portion 56 are press-fitted and fitted.
Further, an O-ring seal rubber 18 is interposed between the lower surface of the ceiling wall portion 59 and the upper end surface of the rising wall portion 56.

  The lid 53 is provided with a check valve 61 that opens and closes the communication hole 59b due to a hydraulic pressure difference between the cylinder 52 and the main fluid chamber 7. The check valve 61 opens the communication hole 59b when the internal pressure of the main liquid chamber 7 becomes higher than the internal pressure of the cylinder portion 52, and allows the liquid to flow from the main liquid chamber 7 into the cylinder portion 52. This is a positive pressure valve that closes the communication hole 59b when the internal pressure of the main liquid chamber 7 becomes lower than the internal pressure of the cylinder portion 52 and restricts the flow of liquid from the cylinder portion 52 to the main liquid chamber 7.

  More specifically, the check valve 61 is a plate member having a circular shape in plan view and made of an elastic body such as elastically deformable rubber. The check valve 61 is disposed perpendicular to the axis O and is disposed between the top wall 59 of the lid 53 and the top wall 54 of the cylinder 52 (inside the rising wall 56). It is in close contact with the top wall 59 of the lid 53 from the cylinder part 52 side (lower side) and closes the communication hole 59b. The check valve 61 has an upper surface formed perpendicular to the axis O, is in close contact with the lower surface of the top wall 59 of the lid 53, and has a tapered surface with the lower surface inclined with respect to the axis O. The check valve 61 gradually decreases in thickness toward the outer side in the radial direction. Further, a cylindrical convex portion 61 a that is inserted into the insertion hole 59 a of the lid portion 53 protrudes from the upper surface of the central portion of the check valve 61, and a circular shape is formed on the lower surface of the central portion of the check valve 61. A recess 61b is formed.

The movable member 51 includes a piston portion 62 that is fitted inside the cylinder portion 52 so as to be slidable in the axial direction, and a cylindrical peripheral wall portion 63 that is arranged inside the orifice member 21 (tubular portion 21b). I have.
The movable member 51 described above is provided so as to be movable in the axial direction along the shaft member 17 disposed on the axis O. The shaft member 17 is a rod-shaped member that is inserted inside an insertion tube portion 66 that will be described later, and the upper end portion of the shaft member 17 is inserted inside the bearing portion 58 of the fixed member 50 to be a recess 61 b of the check valve 61. The lower end portion of the shaft member 17 is inserted inside a bearing portion 75 of a bottom cylindrical member 70 described later.

  The piston portion 62 is a plate portion that closes the inside of the cylinder portion 52 in a liquid-tight state, and is disposed to face the lid portion 53. As shown in FIG. 1 and FIG. 4, the piston portion 62 has a schematic configuration in which an annular plate-like disc portion 64 disposed perpendicular to the axis O and an outer edge of the disc portion 64 is erected. A rising portion 65 and an insertion tube portion 66 that is suspended from the inner edge of the disk portion 64 and through which the shaft member 17 is inserted are provided. The rising portion 65 is a cylindrical wall portion extending along the outer edge of the disk portion 64, and the outer peripheral surface of the rising portion 65 is in sliding contact with the inner peripheral surface of the cylinder portion 52. The insertion tube portion 66 is a cylindrical tube portion that extends in the axial direction about the axis O.

  The peripheral wall portion 63 is a cylindrical portion disposed coaxially with the insertion tube portion 66 and the orifice member 21 with the axis O as a common axis, and the piston portion 62 is disposed inside the peripheral wall portion 63 in plan view. Yes. The peripheral wall part 63 includes an upper tapered cylinder part 67 and a straight cylindrical part 68 connected to the lower end of the tapered cylinder part 67.

  The inner peripheral surface (moving wall surface 67a) of the tapered cylindrical portion 67 has a tapered shape that is gradually expanded in diameter as it goes upward, and is inclined with respect to the axial direction. Further, the lower end of the inner peripheral surface of the tapered cylindrical portion 67 is bulged radially inward from the inner peripheral surface of the straight cylindrical portion 68, and the inner peripheral surface of the tapered cylindrical portion 67 and the inner peripheral surface of the straight cylindrical portion 68 are A step is formed between them. On the other hand, the outer diameter of the tapered cylindrical portion 67 and the outer diameter of the straight cylindrical portion 68 are the same, and the outer peripheral surfaces of the tapered cylindrical portion 67 and the straight cylindrical portion 68 (peripheral wall portion 63) are formed in a straight cylindrical shape extending in the axial direction. Has been. Further, the outer diameters of the tapered cylindrical portion 67 and the straight cylindrical portion 68 (the peripheral wall portion 63) are smaller than the inner diameter of the orifice member 21, and a gap is formed between the outer peripheral surface of the peripheral wall portion 63 and the inner peripheral surface of the orifice member 21. It has been opened.

  The above-described piston portion 62 and the peripheral wall portion 63 are connected via a plurality of connecting portions 69. The connecting portion 69 is a wall portion that is erected from the inner peripheral surface of the lower end portion of the tapered cylindrical portion 67 of the peripheral wall portion 63 and connected to the lower surface of the outer peripheral portion of the disk portion 64 of the piston portion 62. A plurality of the connecting portions 69 are arranged at intervals in the circumferential direction, and the piston portion 62 is supported by the plurality of connecting portions 69.

  Further, as shown in FIG. 1, the inner peripheral surface (moving wall surface 67a) of the tapered cylindrical portion 67 is opposed to the fixed wall surface 55a of the peripheral wall portion 55 of the fixing member 50 with an interval therebetween. The high-frequency orifice 15 is defined by the fixed wall surface 55a and the moving wall surface 67a. The high-frequency orifice 15 causes liquid column resonance in the liquid flowing through the high-frequency orifice 15 when vibration in a high-frequency region (for example, about 20 to 200 Hz) such as a booming sound or idle vibration is input to the vibration isolator 1. This is a liquid path for attenuating the vibration, and is tuned so that liquid column resonance occurs with respect to vibration of the lowest frequency (for example, 20 Hz) among the vibrations in the high frequency range described above.

  More specifically, the high-frequency orifice 15 is a liquid flow path that connects the first secondary liquid chamber 8 formed inside the orifice member 21 and the main liquid chamber 7 formed above the partition member 5. Note that the space between the fixed wall surface 55a and the movable wall surface 67a that does not oppose does not function as the high-frequency orifice 15, and the space between the opposed portions of the fixed wall surface 55a and the movable wall surface 67a is the high-frequency orifice 15. It becomes.

  As shown in FIGS. 1 and 5, a bottom portion 16 that closes the lower end of the orifice member 21 is provided at the lower end portion of the orifice member 21. The second secondary liquid chamber 9 is separated. The bottom portion 16 includes a bottom tube member 70 having a substantially bottomed cylindrical shape that is fitted inside the straight tube portion 68 of the peripheral wall portion 63 of the movable member 51 so as to be slidable in the axial direction. A pressing member 71 that is pressed and held, and a membrane 72 that is interposed between the bottom tube member 70 and the pressing member 71.

  The bottom cylinder member 70 includes a circular bottom plate portion 73 arranged perpendicular to the axis O, a cylindrical peripheral wall portion 74 standing on the outer edge of the bottom plate portion, and the center of the upper surface of the bottom plate portion 73. A cylindrical bearing portion 75 erected on the part, and a flange portion 76 circumferentially provided along the outer periphery of the bottom plate portion 73 are provided. The bottom plate portion 73 is formed with a plurality of openings 73a disposed around the bearing portion 75 at intervals in the circumferential direction. The peripheral wall portion 74 is a cylindrical tube portion whose outer diameter is substantially the same as the inner diameter of the straight tube portion 68, and is slidably fitted inside the straight tube portion 68. The bearing portion 75 is a cylindrical portion that extends in the axial direction about the axis O. The flange portion 76 is an annular plate portion disposed on the radially outer side of the bottom plate portion 73, and is sandwiched between the lower end portion of the orifice member 21 and the bottom plate portion 77 of the pressing member 71 over the entire circumference. ing.

The holding member 71 is a lid-like member that is attached to the lower end portion of the orifice member 21, and includes a bottom plate portion 77 disposed perpendicular to the axis O and a peripheral wall erected from the outer edge of the bottom plate portion 77. Part 78. The bottom plate portion 77 is formed with a plurality of openings 77a that are disposed around the axis O at intervals in the circumferential direction. The peripheral wall portion 78 is press-fitted to the outer periphery of the lower end portion of the orifice member 21.
The membrane 72 is a circular disk-like member made of an elastic body such as rubber, for example, and is disposed perpendicular to the axis O. The outer periphery of the membrane 72 is sandwiched between the bottom plate portion 73 of the bottom cylinder member 70 and the bottom plate portion 77 of the pressing member 71.

  Further, the vibration isolator 1 is provided with a coil spring (bias member) (not shown) that biases the above-described movable member 51 upward. The coil spring is provided around the outer periphery of the bearing portion 58 of the movable member 51 and the bearing portion 75 of the bottom cylindrical member 70, and between the disk portion 64 of the piston portion 62 and the bottom plate portion 73 of the bottom cylindrical member 70. Is intervened.

  Next, the operation of the vibration isolator 1 having the above configuration will be described.

  In the vibration isolator 1 having the above-described configuration, the second mounting member 3 is connected to an engine (not shown) via an engine side bracket (not shown), and the first mounting member 2 is connected to a vehicle body (not shown). Thus, it is interposed between the engine and the vehicle body.

When the above-described engine is operated, the high-frequency vibration is transmitted to the second mounting member 3 of the vibration isolator 1 through the engine-side bracket, and the elastic body 4 is elastically deformed.
At this time, when the input vibration is the vibration of the lowest frequency (for example, 20 Hz) among the high-frequency vibrations, the frequency of the input vibration and the resonance frequency of the high-frequency orifice 15 coincide with each other, as shown in FIG. The member 51 does not move, and the liquid in the liquid chamber 6 passes between the main liquid chamber 7 and the first sub liquid chamber 8 through the high frequency orifice 15, and liquid column resonance occurs in the high frequency orifice 15. . Thereby, the spring constant of the vibration isolator 1 is lowered by liquid column resonance in the high-frequency orifice 15, the input vibration is attenuated, and the vibration transmitted to the vehicle body side is reduced.

On the other hand, when the input vibration is a high-frequency vibration among the high-frequency vibrations, the frequency of the input vibration is higher than the resonance frequency of the high-frequency orifice 15. Fluctuates, and the check valve 61 is opened along with the fluid pressure variation of the main fluid chamber 7. More specifically, when the second mounting member 3 moves downward (bound) relative to the first mounting member 2 due to high-frequency vibration, the elastic body 4 is elastically deformed and the volume of the main liquid chamber 7 is reduced. As a result, the fluid pressure in the main fluid chamber 7 increases. As a result, when the hydraulic pressure in the main fluid chamber 7 becomes higher than the hydraulic pressure in the cylinder portion 52 (the hydraulic pressure between the piston portion 62 and the lid portion 53), the check valve 61 is elastically bent downward and deformed. Then, the communication hole 59b formed in the lid portion 53 is opened, and the inside of the cylinder portion 52 and the main liquid chamber 7 are communicated with each other through the communication hole 59b. Thereby, the hydraulic pressure in the cylinder part 52 rises according to the hydraulic pressure in the main liquid chamber 7.
When the hydraulic pressure in the cylinder portion 52 and the hydraulic pressure in the main fluid chamber 7 become equal, the check valve 61 returns to its original shape by the elastic action, and the communication hole 59b is blocked by the check valve 61. Is done.

  Thereafter, when the second mounting member 3 moves upward (rebounds) relative to the first mounting member 2 due to the reaction of the bounce described above, the elastic body 4 is elastically deformed to increase the volume of the main liquid chamber 7. The fluid pressure in the main fluid chamber 7 decreases. At this time, since the check valve 61 is maintained in the closed position, the communication hole 59b remains closed, and the hydraulic pressure in the cylinder portion 52 does not decrease even if the hydraulic pressure in the main fluid chamber 7 decreases. Therefore, the hydraulic pressure in the cylinder part 52 becomes equal to the maximum positive pressure value in the main liquid chamber 7 that fluctuates.

  As the hydraulic pressure in the cylinder portion 52 increases, the movable member 51 moves downward while the piston portion 62 slides along the inner peripheral surface of the cylinder portion 52 as shown in FIG. The moving wall surface 67a of the member 51 is separated from the fixed wall surface 55a of the fixed member 50, the sectional shape of the high-frequency orifice 15 formed by the fixed wall surface 55a and the moving wall surface 67a is enlarged, and the flow path length is shortened. As a result, the resonance frequency in the high frequency orifice 15 increases. In the vibration isolator 1 using such a liquid column resonance, since the frequency at which the hydraulic pressure fluctuation is maximized is generally higher than the frequency at which the vibration transmissibility is minimized, the vibration transmissibility is increased in the process of increasing the frequency. After the pressure reaches a minimum, the reaction force of the spring is adjusted so that the piston portion 62 starts to move with the liquid pressure that starts to rise again, so that the main liquid chamber 7 and the first sub liquid chamber 8 pass through the high frequency orifice 15. The liquid is reciprocated between the two and a liquid column resonance occurs in the high-frequency orifice 15 through which the liquid flows. Therefore, the spring constant of the vibration isolator 1 is reduced, the input vibration is attenuated, and the vibration transmitted to the vehicle body side is reduced. In addition, since the seal rubber 18 is interposed between the upper end surface of the rising wall portion 56 of the cylinder portion 52 of the fixing member 50 and the lower surface of the top wall portion 59 of the lid portion 53 of the fixing member 50, the hydraulic pressure changes. On the other hand, the movable member 51 can be moved more accurately.

  On the other hand, when the vehicle is traveling, vibration having a relatively low frequency, that is, low-frequency vibration having a larger amplitude and smaller frequency (for example, 8 Hz to 15 Hz) than the above-described high-frequency vibration is input. At this time, the hydraulic pressure in the main liquid chamber 7 fluctuates as the second mounting member 3 is repeatedly moved in the vertical direction by the low-frequency vibration (movement that alternately repeats movement in the bounce side and movement in the rebound direction). An internal pressure difference is generated between the main liquid chamber 7 and the second sub liquid chamber 9. In this case, the liquid in the liquid chamber 6 passes between the main liquid chamber 7 and the second sub liquid chamber 9 through the low frequency orifice 12. At this time, the low-frequency orifice 12 is tuned so that the liquid crystal resonance occurs in the flow path length and the cross-sectional area with respect to the low-frequency vibration, so that the liquid column resonance occurs in the liquid flowing through the low-frequency orifice 12. The generated low frequency vibration is attenuated and the vibration transmitted to the vehicle body is reduced.

  According to the vibration isolator 1 having the above-described configuration, the resonance frequency in the high-frequency orifice 15 can be varied according to the frequency of the input high-frequency vibration without using an actuator or control means. Therefore, it is possible to attenuate high-frequency vibrations in a wide frequency range, and it is possible to save space and reduce costs.

  Further, in the above-described vibration isolator 1, the fixed wall surface 55 a and the moving wall surface 67 a are tapered surfaces that are inclined with respect to the moving direction of the movable member 51, and the movable member 51 is moved by the hydraulic pressure inside the cylinder portion 52. When moved downward, the cross-sectional shape of the high-frequency orifice 15 is increased and the flow path length is shortened, so that the resonance frequency of the high-frequency orifice 15 is efficiently increased. That is, the change width of the resonance frequency of the high-frequency orifice 15 with respect to the moving stroke of the movable member 51 becomes larger than when either the cross-sectional shape or the flow path length changes. Therefore, the moving stroke of the movable member 51 can be shortened, and the vibration isolator 1 can be downsized.

  In the vibration isolator 1 described above, in addition to the high-frequency orifice 15 that communicates the main liquid chamber 7 and the first sub-liquid chamber 8, the low-frequency orifice that communicates the main liquid chamber 7 and the second sub-liquid chamber 9. When a high frequency vibration is input, liquid column resonance occurs in the high frequency orifice 15 to attenuate the input vibration. When a low frequency vibration is input, the low frequency orifice 12 is provided. Since liquid column resonance occurs and the input vibration is damped, vibration isolation performance can be exhibited against both high frequency vibration and low frequency vibration.

As mentioned above, although the embodiment of the vibration isolator according to the present invention has been described, the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist thereof.
For example, in the above-described embodiment, the fixed wall surface 55a and the moving wall surface 67a are inclined with respect to the moving direction of the movable member 51, but the present invention is not limited to this. For example, the fixed wall surface and the moving wall surface may be formed perpendicular to the moving direction of the movable member. In this case, the movement of the movable member relative to the fixed member changes the cross-sectional area of the restriction passage, but the flow path length does not change. Further, the fixed wall surface and the moving wall surface may be formed in parallel to the moving direction of the movable member. In this case, the flow path length of the restriction passage is changed by the movement of the movable member relative to the fixed member, but the cross-sectional area is not changed.

  In the above-described embodiment, the restriction passage formed by the fixed wall surface 55a and the moving wall surface 67a is the high-frequency orifice 15 corresponding to high-frequency vibration, and the restriction passage formed by the circumferential groove 21a of the orifice member 21 is In the present invention, the resonance frequency of the high frequency orifice 15 and the low frequency orifice 12 can be changed as appropriate, and the fixed wall surface and the movement can be changed. The restriction passage formed by the wall surface may be tuned so as to correspond to the low frequency range vibration, and the other restriction passage formed may be tuned so as to correspond to the high frequency range vibration.

In the above-described embodiment, as the hydraulic pressure in the main fluid chamber 7 increases, the positive pressure check valve 61 opens to move the movable member 51 downward, and the resonance frequency in the high-frequency orifice 15 increases. However, according to the present invention, a check valve is attached to the upper surface of the ceiling wall 59 of the lid 53, and the check valve is a negative pressure valve that opens as the liquid pressure in the main liquid chamber 7 decreases. It is also possible to adopt a configuration in which the check valve is opened along with the decrease in the hydraulic pressure 7 so that the movable member 51 moves upward and the resonance frequency in the high-frequency orifice 15 decreases.
Further, in the above-described embodiment, the check valve 61 opens and closes the communication hole 59b due to the hydraulic pressure difference between the inside of the cylinder portion 52 and the main fluid chamber 7, but the present invention responds to input vibration. For example, a check valve that is opened and closed by transmitting vibration stress can be used.

In the above-described embodiment, the low-frequency orifice 12 (second restriction passage) is formed in the orifice member 21. However, in the present invention, a second restriction passage may be formed in addition to the orifice member 21. . For example, the second restriction passage may be formed by grooving a part of the outer cylinder 20, or the second restriction passage may be formed by grooving a part of a caulking portion of a diaphragm ring that holds the diaphragm. May be.
Furthermore, in the present invention, the second restriction passage (low frequency orifice 12) can be omitted. For example, a configuration in which the orifice member 21, the pressing member 71, and the membrane 72 are omitted, the bottom cylinder member 70 is fitted to the outer cylinder 20, and the diaphragm 10 is joined to the outer peripheral portion of the bottom cylinder member 70.

  Further, in the above-described embodiment, the first sub liquid chamber 8 and the second sub liquid chamber 9 are separated by the bottom portion 16, but the present invention omits the membrane 72 and the pressing member 71, and It is also possible to make the liquid chamber 8 and the second sub liquid chamber 9 communicate with each other.

  In the above-described embodiment, the compression type vibration isolator 1 in which a positive pressure is applied to the main liquid chamber 7 when a support load is applied has been described. However, the main liquid chamber 7 is positioned on the lower side in the vertical direction. In addition, the auxiliary liquid chambers 8 and 9 are mounted so as to be positioned on the upper side in the vertical direction, and can be applied to a suspension type vibration isolator in which a negative pressure is applied to the main liquid chamber 7 when a support load is applied.

  In the above-described embodiment, the first mounting member 2 is connected to the vehicle body (vibration receiving portion), and the second mounting member 3 is connected to the engine (vibration generating portion). The attachment member 2 may be connected to the engine (vibration generating portion), and the second attachment member 3 may be connected to the vehicle body (vibration receiving portion).

  Further, the vibration isolator according to the present invention is not limited to the engine mount of the vehicle, but can be applied to the vibration isolator other than the engine mount. For example, the present invention can be applied to a mount of a generator mounted on a construction machine, or can be applied to a mount of a machine installed in a factory or the like.

  In addition, in the range which does not deviate from the main point of this invention, it is possible to replace suitably the component in above-mentioned embodiment with a well-known component, and you may combine the above-mentioned modification suitably.

DESCRIPTION OF SYMBOLS 1 Anti-vibration device 2 1st attachment member 3 2nd attachment member 4 Elastic body 5 Partition member 6 Liquid chamber 7 Main liquid chamber 8 First sub liquid chamber (Sub liquid chamber, 1st sub liquid chamber)
9 Second secondary liquid chamber (second secondary liquid chamber)
12 Low frequency orifice (second restricted passage)
15 High-frequency orifice (restricted passage, first restricted passage)
50 fixed member 51 movable member 52 cylinder portion 53 lid portion 55a fixed wall surface 62 piston portion 67a moving wall surface

Claims (3)

A cylindrical first mounting member coupled to one of the vibration generating unit and the vibration receiving unit, and a second mounting member coupled to the other;
An elastic body that elastically connects the first mounting member and the second mounting member;
A partition member that partitions the liquid chamber in the first mounting member into a main liquid chamber on one side and a sub liquid chamber on the other side, the elastic body being a part of a wall surface;
A liquid-filled vibration isolator in which the partition member is connected to the main liquid chamber and the sub liquid chamber and a restriction passage is formed in which liquid column resonance occurs when the liquid in the liquid chamber flows. ,
The partition member is fixed to the inner side of the first mounting member, and includes a cylindrical cylinder portion and a fixing member provided on an end portion of the cylinder portion on the main liquid chamber side, and the cylinder portion A movable member having a piston portion disposed inside and facing the lid portion,
The lid portion is provided with a communication hole that communicates the inside of the cylinder portion and the main liquid chamber, and a check valve that opens and closes the communication hole.
The restriction passage is defined by a fixed wall surface formed on the fixed member and a movable wall surface formed on the movable member and disposed opposite to the fixed wall surface,
An anti-vibration device according to claim 1, wherein at least one of a cross-sectional shape and a flow path length of the restriction passage changes to change a resonance frequency of the restriction passage. The vibration isolator according to claim 1,
The anti-vibration device, wherein the fixed wall surface and the movable wall surface are inclined with respect to the moving direction of the movable member. In the vibration isolator according to claim 1 or 2,
The restriction passage is a first restriction passage in which liquid column resonance occurs with respect to any one of input vibrations in different frequency ranges,
The sub liquid chamber is communicated with the main liquid chamber via the first restricting passage in which liquid column resonance occurs with respect to any one of the input vibrations in different frequency ranges. And the fluid in the liquid chamber is communicated with the main liquid chamber via a second restriction passage in which liquid column resonance occurs with respect to any one of the input vibrations in different frequency ranges due to the circulation of the liquid. And a second auxiliary liquid chamber.

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