JP2004340312A - Liquid sealed mount - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a hammering noise accompanying a motion of a sub-diaphragm 6. <P>SOLUTION: A pressure inducing chamber D communicating with both liquid chambers A and B via pressure inducing holes 51e and 52b is formed in a partition 5 arranged to divide into the first liquid chamber A at an elastic body 3 and the second liquid B at a diaphragm 4 side. In the pressure inducing chamber D, the sub-diaphragm 6 can be displaced in the thickness direction and is arranged to block between both the liquid chambers A and B, and a liquid pressure releasing passage L consisting of a slit is formed in the sub-diaphragm 6. When vibration with large amplitude is input, a part of the pressure in working liquid at a high pressure side is released into a low pressure side through the liquid pressure releasing passage L owing to the pressure difference between the liquid chambers A and B acting on the sub-diaphragm 6 to reduce the pressure difference so as to relax collision force of the sub-diaphragm 6 with the partition 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention belongs to the anti-vibration technology, and is used as anti-vibration support means for, for example, an engine of an automobile, and is a liquid encapsulation that buffers and reduces vibration by deformation of an elastic body and movement of a working liquid accompanying the deformation. Regarding the expression mount.
[0002]
[Prior art]
Conventionally, as an engine mount that supports a power unit including an engine and a transmission in a vehicle in a vibration-proof manner, a liquid-filled mount that absorbs and reduces vibration by deformation of an elastic body and movement of a working liquid accompanying the elastic body has been known. 2. Description of the Related Art As this type of liquid-filled mount, for example, a mount disclosed in Patent Literature 1 below is conventionally known.
[0003]
[Patent Document 1]
JP-A-7-269633 (FIG. 1)
[0004]
That is, the liquid-filled mount has a structure in which an outer cylindrical first mounting member and an inner second mounting member are connected by a conical elastic body made of a rubber-like elastic material. Between the elastic body and the diaphragm provided above the elastic body, the partition defines a lower liquid chamber on the elastic body side and an upper liquid chamber on the diaphragm side, and both liquid chambers are formed in the partition. They communicate with each other through orifices. A pressure guiding chamber communicating with the two liquid chambers is formed in the partition, and a sub-diaphragm (denoted as a membrane rubber in Patent Document 1) can be displaced in the thickness direction in the pressure guiding chamber. Further, it is arranged so as to close the space between the two liquid chambers.
[0005]
In this liquid-filled mount, the first mounting member is connected to the vehicle body side and the second mounting member is connected to the power unit side including the engine, and the weight of the power unit is elastically suspended by an elastic body. When the input vibration is caused by idling of the engine or the like, the pressure change in the lower liquid chamber due to the repetitive deformation of the elastic body between the first mounting member and the second mounting member causes the pressure change in the pressure guiding chamber. Absorbed by the resonance of the sub-diaphragm, the dynamic spring constant is reduced, and the vibration transmission is insulated. If the input vibration is of low frequency and large amplitude due to shock from the road surface while the vehicle is running, the hydraulic fluid repeatedly flows through the orifice as the volume of the lower fluid chamber changes due to deformation of the elastic body. The vibration is quickly converged by the damping effect at this time.
[0006]
[Problems to be solved by the invention]
However, in this type of liquid-filled mount, when a large-amplitude vibration due to a shock from the road surface or the like is input, the sub-diaphragm in the impulse chamber receives a sudden change in pressure in the lower liquid chamber, so that the impulse chamber is There was a problem that the inner wall (partition wall) violently collided and a tapping sound was generated.
[0007]
The present invention has been made in view of the above-described problems, and a technical problem thereof is to reduce a tapping sound accompanying the operation of the sub-diaphragm.
[0008]
[Means for Solving the Problems]
As a means for effectively solving the above-described technical problem, the liquid-filled mount according to claim 1 is a cylindrical first mounting member connected to the support body side, and is disposed on the inner periphery thereof to be supported. A second mounting member connected to the vibrating body side, an elastic body joined between the first mounting member and the second mounting member, a diaphragm having an outer peripheral edge sealed to the first mounting member, and the elastic body And a partition formed with an orifice formed so as to separate the liquid sealing space between the diaphragm into the first liquid chamber on the elastic body side and the second liquid chamber on the diaphragm side and communicating the two liquid chambers, A sub-diaphragm formed in the partition wall and disposed in the pressure-guiding chamber communicating with the two liquid chambers, the sub-diaphragm being arranged to be displaceable in the thickness direction and closing between the two liquid chambers. Hydraulic release passage consisting of holes It is obtained by forming.
[0009]
In the liquid sealing mount according to the second aspect, in the configuration described in the first aspect, at least a part of the hydraulic pressure release passage overlaps with the pressure guiding hole communicating the pressure guiding chamber and the two liquid chambers. It is provided in.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of a liquid-filled mount according to the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a liquid-filled mount according to a first embodiment, FIG. 2 is a view of a partition 5 in FIG. 1 viewed from a first liquid chamber A side, and FIG. FIG. 4 is an enlarged half sectional view, and FIG. 4 is a plan view showing the sub-diaphragm 6 in FIG.
[0011]
As shown in FIG. 1, the liquid-filled mount includes a first mounting member 1, a second mounting member 2 disposed on an inner periphery thereof, and a first mounting member 1 and a second mounting member 2. , A diaphragm 4 above the outer peripheral edge 4 a of which is sealed to the first mounting member 1, and a liquid sealing space between the elastic body 3 and the diaphragm 4 on the elastic body 3 side ( A partition 5 is provided so as to be separated into a first liquid chamber A on the lower side and a second liquid chamber B on the side of the diaphragm 4 (upper side), and a sub-diaphragm 6 held in the partition 5.
[0012]
The first mounting member 1 has a cylindrical shape, and has a cylindrical metal case 11 and a metal outer press-fitted to the outer peripheral surface of a small-diameter portion 11a stepped at the lower end thereof. And a ring 12. The first mounting member 1 is connected to a body frame side corresponding to the support body side by a bolt (not shown) at a mounting arm 12a formed integrally with the outer ring 12.
[0013]
The second mounting member 2 is integrally connected to a metal cup-shaped flange 21 arranged on the inner periphery of the first mounting member 1 by welding or the like on the bottom lower surface thereof, and the lower end of the second mounting member 2 is formed outside the first mounting member 1. And a metal inner cylinder 22 extending below the ring 12. The second mounting member 2 is tightened to an engine-side bracket 24 corresponding to the supported vibrator according to claim 1 through a bolt 23 screwed into a female screw hole on the inner periphery of the inner cylinder 22. You.
[0014]
The elastic body 3 is made of a rubber-like elastic material, and is formed from the outer periphery of the conical side wall portion of the cup-shaped flange 21 of the second mounting member 2 which is open upward, and the case of the first mounting member 1. It has a substantially conical shape extending obliquely downward toward the inner surface of the step portion 11 and the small diameter portion 11a. Since the elastic body 3 is a main body that elastically supports a load of a power unit including an engine and a transmission, which are supported vibration bodies, the elastic body 3 has a sufficiently large thickness and a distortion when subjected to vertical deformation. It is formed thicker toward the inner circumference so as to be substantially uniform on the inner circumference side and the outer circumference side.
[0015]
The case 11 in the first mounting member 1, the cup-shaped flange 21 and the inner cylinder 22 in the second mounting member 2, and the elastic body 3 form an integral vulcanized molded body. That is, in the vulcanized molded body, the case 11, the cup-shaped flange 21 and the inner cylinder 22 connected to each other are positioned and set in a predetermined rubber vulcanization mold (not shown), and the mold is clamped. An unvulcanized rubber material is filled into a molding cavity defined between the case 11 and the cup-shaped flange 21 and the inner cylinder 22 by a mold, and is heated and pressed to vulcanize the elastic body 3. The molding and the vulcanization bonding of the elastic body 3 to the case 11, the cup-shaped flange 21, and the inner cylinder 22 are simultaneously performed.
[0016]
The elastic body 3 has an elastic film 31 extending from the outer peripheral portion thereof so as to cover the inner peripheral surface of the case 11 of the first mounting member 1 and an elastic film extending from the inner peripheral portion so as to cover the inner surface of the cup-shaped flange 21. The film 32 is formed continuously.
[0017]
A caulking portion 11b having a substantially U-shaped cross section is formed at an upper end portion of the case 11 in the first mounting member 1, and an outer peripheral edge 4a of the diaphragm 4, an outer peripheral portion of the partition wall 5, and a lower flange portion 6a of the cover 6 are mutually connected. It is fixed to the caulking portion 11b in a state of being closely contacted. The outer peripheral portions of the partition wall 5 and the cover 6 are sealed by an elastic film 31 extending from the inner peripheral surface of the case 11 to the inner surface of the caulking portion 11b.
[0018]
The diaphragm 4 is made of a rubber-like elastic material, is formed to be sufficiently thinner than the elastic body 3, and is formed in a substantially flat plate shape to allow smooth displacement and deformation. . The outer peripheral edge 4 a in which the metal reinforcing ring 41 is buried is closely fitted to the outer peripheral portion of the partition wall 5 and is fixed by the swaging portion 11 b of the case 11.
[0019]
The partition wall 5 includes an upper plate 51 and a lower plate 52 which are formed into a disc shape with metal or synthetic resin. As shown in FIGS. 2 and 3, a locking projection 51 a is formed at the center of the lower surface of the upper plate 51, and an inner peripheral hole of the lower plate 52 is fitted to the locking projection 51 a. As a result, the upper plate 51 and the upper plate 51 are combined in a superposed state.
[0020]
A peripheral groove 51b extending in the circumferential direction is formed in the outer peripheral portion of the lower surface of the upper plate 51 in the partition wall 5, and the peripheral groove 51b is formed in the outer peripheral portion of the lower plate 52 existing so as to cover the lower side. Defines an orifice C extending in a substantially C-shape in the circumferential direction. One end of the orifice C is opened to a lower first liquid chamber A through an opening 52a opened in the lower plate 52, and the other end is opened to an upper second liquid chamber A through an opening 51c opened in the upper plate 51. It is open to the liquid chamber B.
[0021]
On the inner peripheral side of the orifice C, a flat annular pressure guide is formed by a shallow annular concave portion 51d formed on the inner peripheral side of the end groove 51b on the lower surface of the upper plate 51 and the lower plate 52 existing below the shallow annular concave portion. A chamber D is formed. The pressure-guiding chamber D communicates with the lower first liquid chamber A through a number of pressure-guiding holes 52b formed in the lower plate 52, and a plurality of pressure-guiding holes 51e formed in the upper plate 51. And the upper second liquid chamber B.
[0022]
The sub-diaphragm 6 is made of a rubber-like elastic material and is formed into a disk shape. The sub-diaphragm 6 is provided in the pressure guiding chamber D of the partition wall 5 so as to block the space between the first liquid chamber A and the second liquid chamber B. As shown in FIG. 3, the inner peripheral hole 6 a is substantially in close contact with the inner peripheral wall of the pressure guiding chamber D, and the outer peripheral edge 6 b is substantially in close contact with the outer peripheral wall of the pressure guiding chamber D. Further, the sub-diaphragm 6 has a thickness t smaller than the inner dimension s above and below the pressure guiding chamber D, and therefore can be displaced in the pressure guiding chamber D in the thickness direction (up and down).
[0023]
The sub-diaphragm 6 is formed with a hydraulic pressure release passage L penetrating in the thickness direction. In the present embodiment, as shown in FIGS. 2 and 4, the hydraulic pressure release passage L includes a plurality (for example, eight) of slits 61 provided at equal intervals in the circumferential direction and radially extending in the radial direction. At least a part thereof overlaps the pressure guiding holes 52b and 51e in the partition wall 5.
[0024]
The liquid sealing space including the first liquid chamber A, the second liquid chamber B, the orifice C, and the pressure guiding chamber D is filled with an incompressible hydraulic fluid having an appropriate viscosity, such as silicone oil. The working fluid is fixed by swaging the partition wall 5 and the diaphragm 4 into the swaging portion 11b of the case 11 integrated with the elastic body 3 and the second mounting member 2 in the liquid such as the silicone oil stored in the liquid tank. Thereby, a part of the liquid is confined.
[0025]
In the liquid-filled mount configured as described above, the mounting arm 12a of the outer ring 12 in the first mounting member 1 is connected to the vehicle body frame side, and the second mounting member 2 is connected to the engine-side bracket 24. The power unit including the engine is elastically supported on the vehicle body frame. In this mounting state, when the vertical vibration V is input from the power unit or the road surface while the vehicle is traveling, the first mounting member 1 and the second mounting member 2 are repeatedly vertically displaced relative to each other, and the two mounting members 1 and 2 are repeatedly displaced. The vibration V is effectively absorbed by the elasticity of the elastic body 3 that is repeatedly deformed between them.
[0026]
When the input vibration V is a continuous and small-amplitude medium / high frequency vibration caused by, for example, engine vibration during idling of the engine, the sub-diaphragm 6 resonates and repeats up and down in the pressure guiding chamber D. Due to the displacement, the change in the liquid pressure of the first liquid chamber A due to the deformation of the elastic body 3 is absorbed. For this reason, the dynamic spring of the mount is lowered, and the transmission of vibration is effectively insulated.
[0027]
When the input vibration V is a large-amplitude, low-frequency vibration caused by a shock input, such as when the vehicle is running on a road surface or when the vehicle is running, the first mounting member 1 is moved upward together with the body frame. In the first half cycle in which the second mounting member 2 is displaced downward together with the power unit due to the dismounting or dropping, the lower part of the case 11 in the first mounting member 1 and the cup-shaped flange 21 in the second mounting member 2 In the meantime, as the elastic body 3 is compressed, the volume of the first liquid chamber A is increased, so that the liquid pressure in the first liquid chamber A becomes a negative pressure. For this reason, due to the pressure difference between the first liquid chamber A and the second liquid chamber B introduced into the pressure guiding chamber D through the pressure guiding holes 52b and 51e, the sub-diaphragm 6 is displaced downward in the pressure guiding chamber D to partition the partition. 5 and the hydraulic fluid moves from the second fluid chamber B to the first fluid chamber A through the orifice C. In the next half cycle, that is, in the rebound process, the volume of the first liquid chamber A shifts to the reduction process, so that the sub-diaphragm 6 is displaced upward in the pressure guiding chamber D and pressed against the upper plate 51 of the partition wall 5. At the same time, the hydraulic fluid moves from the first liquid chamber A to the second liquid chamber B through the orifice C.
[0028]
The liquid column resonance frequency of a vibration system including the hydraulic fluid in the orifice C as a mass and a spring system including the elastic body 3 and the diaphragm 4 forming the first fluid chamber A and the second fluid chamber B is as follows. The vibration is tuned to the frequency range of the vibration due to the above-mentioned shock input. Therefore, the repetitive movement of the hydraulic fluid in the orifice C is promoted by the liquid column resonance, and the high damping due to the viscosity of the hydraulic fluid occurs. , The vibration V is quickly converged.
[0029]
Further, when a large amplitude vibration is input due to the above-described shock or the like, a part of the hydraulic fluid is partially removed by the pressure difference between the liquid chambers A and B acting on the sub-diaphragm 6 through the pressure guiding holes 52b and 51e. Of the sub-diaphragm 6 against the inner surface of the partition wall 5 (the lower plate 52 or the upper plate 51), the impact force is reduced. You.
[0030]
Note that the flow rate of the hydraulic fluid passing through the hydraulic pressure release passage L, in other words, the action of alleviating the collision of the sub-diaphragm 6 with a large amplitude vibration input depends on the number, size, shape, etc. of the hydraulic pressure release passages L. You. However, at this time, the flow rate of the hydraulic fluid passing through the orifice C is reduced by an amount corresponding to the flow rate passing through the hydraulic pressure release passage L, as compared with the conventional structure having no hydraulic pressure release passage L, That is, since the damping force by the orifice C decreases, the flow rate of the hydraulic pressure release passage L needs to be set appropriately. Further, by appropriately restricting the flow rate in the hydraulic pressure release passage L, a decrease in the damping force at the orifice C can be compensated for by the damping force generated in the hydraulic pressure release passage L.
[0031]
FIGS. 5 to 8 are plan views of the sub-diaphragm 6 showing an example of the shape of the hydraulic pressure release passage L as another embodiment of the present invention.
[0032]
In the embodiment shown in FIG. 5, the hydraulic pressure release passage L has a plurality of slits 61 formed in a circular arc concentric with the disk-shaped sub-diaphragm 6 and formed at equal intervals in the circumferential direction. In the embodiment of FIG. 7, the hydraulic pressure release passage L is formed of a slit 61 extending in a C-shape or U-shape on the outer periphery of the inner peripheral hole of the sub-diaphragm 6, and in the form of FIG. 8 comprises a plurality of small holes 62 formed at equal intervals in the circumferential direction. In the embodiment shown in FIG. 8, the hydraulic pressure release passage L comprises a slit 61 extending in a C-shape around the outer periphery of the inner peripheral hole of the sub-diaphragm 6. The gap G is made larger than the slit 61 of FIGS. 4, 5 and 6. In any case, the slit 61 or the small hole 62 is formed so that at least a part thereof overlaps with the pressure guiding holes 52b and 51e of the partition wall 5 shown in FIG. 2 or FIG.
[0033]
Also in these embodiments, the hydraulic pressure release passage L of the sub-diaphragm 6 has the same operation and effect as the first embodiment. In particular, as shown in FIGS. 6 and 8, the hydraulic pressure release passage L has a C-shaped or U-shaped slit 61 or an arc-shaped slit 61 as shown in FIG. When a pressure difference acts on the sub-diaphragm 6, the valve-like portion 61a inside the slit 61 bends to the low-pressure side in a responsive manner like a reed valve and releases the pressure instantaneously. 6 can be more effectively reduced. In addition, when the sub-diaphragm 6 is pressed against the lower plate 52 or the upper plate 51, the valve-shaped portion 61a immediately closes, so that a decrease in the flow rate at the orifice C can be suppressed as much as possible.
[0034]
Further, instead of forming the slits 61 and the small holes 62, the sub-diaphragm 6 may be formed of porous foamed rubber to have a hydraulic pressure release passage formed by a large number of fine small holes (open cells). It is valid. In this case, in addition to the above-described action of alleviating the collision force due to the release of the pressure, the cushioning property of the sub-diaphragm 6 itself is increased by the internal bubbles, and the generation of a tapping sound can be effectively suppressed.
[0035]
In the above-described embodiment, the power unit suspension type in which the elastic body 3 is provided below the partition 5 and the diaphragm 4 is provided above the partition 5 as shown in FIG. The present invention can be implemented in a similar manner in a case where the diaphragm 4 is provided on the side.
[0036]
【The invention's effect】
According to the liquid-filled mount according to the first aspect of the present invention, when a large-amplitude vibration is input, the pressure difference between the first liquid chamber and the second liquid chamber acting on the sub-diaphragm causes the pressure of the high-pressure side hydraulic fluid to increase. Is released to the low-pressure side through the hydraulic pressure release passage of the sub-diaphragm, and the pressure difference is reduced, so that the collision force of the sub-diaphragm against the partition is alleviated, and as a result, the hitting sound can be reduced.
[0037]
According to the liquid-filled mount according to the second aspect of the present invention, since the hydraulic pressure release passage overlaps with the pressure guiding hole of the partition wall, the pressure difference can be reduced more smoothly, and the tapping sound can be effectively reduced. can do.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a liquid-filled mount according to a first embodiment of the present invention.
FIG. 2 is a view of a partition wall 5 in FIG. 1 as viewed from a first liquid chamber A side.
FIG. 3 is a half sectional view showing a part of FIG. 1 in an enlarged manner.
FIG. 4 is a plan view showing a sub-diaphragm 6 in FIG.
FIG. 5 is a plan view of a sub-diaphragm 6 showing a shape example of a hydraulic pressure release passage L as another embodiment of the present invention.
FIG. 6 is a plan view of a sub-diaphragm 6 showing a shape example of a hydraulic pressure release passage L as another embodiment of the present invention.
FIG. 7 is a plan view of a sub-diaphragm 6 showing a shape example of a hydraulic pressure release passage L as another embodiment of the present invention.
FIG. 8 is a plan view of a sub-diaphragm 6 showing a shape example of a hydraulic pressure release passage L as another embodiment of the present invention.
[Explanation of symbols]
1 First mounting member 2 Second mounting member 24 Engine side bracket (supported vibration body side)
3 Elastic body 4 Diaphragm 5 Partition wall 51 Upper plate 51e, 52b Pressure guide hole 52 Lower plate 6 Sub-diaphragm 61 Slit 61a Valve portion 62 Small hole A First liquid chamber B Second liquid chamber C Orifice D Pressure guiding chamber L Hydraulic pressure Open passage

Claims (2)

A cylindrical first mounting member (1) connected to the support side, a second mounting member (2) arranged on the inner periphery thereof and connected to the supported vibrator side (24), and the first mounting member An elastic body (3) joined between (1) and the second mounting member (2); a diaphragm (4) having an outer peripheral edge (4a) sealed to the first mounting member (1); The liquid sealing space between the body (3) and the diaphragm (4) is separated into a first liquid chamber (A) on the elastic body (3) side and a second liquid chamber (B) on the diaphragm (4) side. And a partition (5) formed with an orifice (C) communicating with the liquid chambers (A, B), and the liquid chambers (A, B) formed in the partition (5). A sub-diaphragm (6) displaceable in the thickness direction into a pressure-guiding chamber (D) communicating with the sub-diaphragm and disposed so as to close between the two liquid chambers (A, B); Comprising a liquid-sealed mounting, characterized in that a slit (61) or small holes hydraulic open passage consisting of (62) (L) in the sub-diaphragm (6). At least a part of the hydraulic pressure release passage (L) is provided at a position where it overlaps with the pressure guiding holes (51e, 52b) communicating the pressure guiding chamber (D) and the two liquid chambers (A, B). The liquid-sealed mount according to claim 1.

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