JP2009299772A - Liquid-sealed vibration control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid-sealed vibration control device capable of reducing shock of cavitation without causing a cost increase and instability in vibration control characteristic. <P>SOLUTION: A partition member 4 for partitioning a main liquid chamber 6 and a sub-liquid chamber 7, is composed of a skeleton part 21 composed of a high elastic material and a covering part 22 for covering the skeleton part 21 with a low elastic material lower in elasticity than this high elastic material. A thermoplastic resin is used as the high elastic material, and thermoplastic elastomer being the same in a base polymer as a high elastic resin is used as the low elastic material. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention comprises a central member, a cylindrical member disposed on the outer side in the radial direction of the central member, and a rubber member that is disposed between these members and connects these members to each other. A partition member that is liquid-tightly attached to the cylindrical member is disposed on one side in the axial direction, a main liquid chamber is formed between the partition member and the rubber member, and the partition of the main liquid chamber A liquid formed by providing a membrane member on the opposite side of the member, forming a secondary liquid chamber between the membrane member and the partition member, and communicating these liquid chambers through an orifice formed in the partition member. The present invention relates to a sealed vibration isolator, and particularly to a device capable of suppressing abnormal noise and abnormal vibration associated with a cavitation phenomenon in liquid.

  A central member, a cylindrical member disposed radially outward of the central member, and a rubber member that connects the members over the entire circumference between the members, on one side in the axial direction of the rubber member A partition member attached in a liquid-tight manner to the tubular member, a main liquid chamber is formed between the partition member and the rubber member, and the main liquid chamber is opposite to the partition member A liquid-filled vibration isolator formed by providing a membrane member on the side, forming a secondary liquid chamber between the partition member and the membrane member, and communicating these liquid chambers with each other through an orifice formed in the partition member, Conventionally known, this device is configured to give a desired vibration-proofing performance to the vibration when the central member and the cylindrical member are relatively displaced in the axial direction by the resonant action of the fluid passing through the orifice. For example, supporting the engine It used to reduce the vibrations transmitted to the vehicle body side from the engine.

  In such a liquid-filled vibration isolator, it has been known that abnormal noise or abnormal vibration occurs when a large vibration is suddenly input. Problems have become apparent with the reduction in the size and weight of the engine mount and the improvement in the quietness of the power unit including the engine. This is because when a large vibration is input, bubbles are generated in the vicinity of the partition member around the orifice entrance in the main liquid chamber, and the energy generated when the generated bubbles disappear becomes water hammer pressure and the surroundings It has been found that this is a so-called cavitation phenomenon in which abnormal noise or abnormal vibration is generated by vibrating a wall.

As a liquid-filled vibration isolator capable of effectively suppressing such a cavitation phenomenon, a partition member located in the vicinity of generating a lot of bubbles is divided into a partition metal fitting and a covering rubber vulcanized and bonded to this surface. There has been proposed a configuration in which the water hammer pressure is attenuated and relaxed by the covering rubber (see, for example, Patent Document 1).
JP 2004-204964 A

  However, in the conventional technology described above, first, since rubber is vulcanized and bonded to the partition metal fitting, the adhesive application process and the vulcanization process are inevitable, and the cost is high. For this purpose, it is necessary to make the partition metal thin in order to reduce the cost. In this case, in addition to lowering the rigidity as the partition member, the orifice itself, which plays a dominant role in the vibration isolation characteristics, is coated rubber. Therefore, there is a problem that the vibration-proof characteristic becomes unstable.

  The present invention has been made in view of such problems, and is a liquid that can suppress the generation of abnormal noise and abnormal vibration caused by the cavitation phenomenon without incurring high costs and instability of vibration isolation characteristics. An object of the present invention is to provide an enclosed vibration isolator.

<1> includes a central member, a cylindrical member disposed on the outer side in the radial direction of the central member, and a rubber member that is disposed between the members and connects the members, and the rubber member A partition member that is liquid-tightly attached to the cylindrical member is disposed on one side of the cylindrical member, and a main liquid chamber is formed between the partition member and the rubber member. A membrane member is provided on the opposite side of the partition member, a secondary liquid chamber is formed between the membrane member and the partition member, and these liquid chambers communicate with each other through an orifice formed in the partition member. In the liquid filled type vibration damping device, the partition member is constituted by a skeleton portion made of a highly elastic material and a covering portion that covers the skeleton portion with a low elastic material having lower elasticity than the high elastic material.
The liquid-encapsulated vibration isolator is made of a thermoplastic resin as the high-elasticity material and the thermoplastic elastomer having the same base polymer as the high-elasticity resin as the low-elasticity material.

  <2> is a liquid-filled vibration isolator in which the base polymer is PP (polypropylene) or PA (polyamide) in <1>.

  <3> is a liquid-filled vibration isolator according to <1> or <2>, wherein the surface area of the covering portion is 90% or more of the surface area of the partition member.

  <4> is a liquid-filled vibration damping device according to any one of <1> to <3>, wherein a thickness of the covering portion is set to 0.5 to 5 mm.

  <5> In any one of <1> to <4>, a flow path is formed around the partition member on the side facing the main liquid chamber by selectively vibrating in response to an input having a predetermined frequency or higher. A membrane accommodating chamber for accommodating the membrane configured to be provided, an opening communicating with the auxiliary liquid chamber on the bottom surface of the membrane accommodating chamber, and the covering portion also disposed on the surface of the membrane accommodating chamber. This is a liquid-filled vibration isolator.

  <6> is any one of <1> to <5>, wherein a pressing plate that closes the membrane housing chamber in a state in which the membrane is accommodated is attached to the partition member, and the main liquid chamber and the membrane are accommodated in the pressing plate. This is a liquid-filled vibration isolator formed with an opening hole that allows liquid to communicate with the chamber.

  <7> is any one of <1> to <6>, wherein the partition member is injected into the cavity of a coating portion molding die in which a molded skeleton portion is inserted, and the low elastic material is injected into the mold. It is a liquid-filled vibration isolator formed by curing with

  <8> is any one of <1> to <7>, wherein the main body is connected to the orifice formed in the partition member from the main liquid chamber. A liquid-filled vibration isolator configured to expand and contract a part of the flow path of the orifice by elastically deforming the valve body by a pressure difference between the main liquid chamber and the orifice. is there.

  According to <1>, the high elastic resin and the base polymer are used as the low elastic material constituting the covering portion that covers the skeleton while using the thermoplastic resin as the high elastic material constituting the skeleton of the partition member. Since the same thermoplastic elastomer is used, when the partition member is molded, the skeleton part is molded, and this is inserted into the mold for forming the cover part, and the low elastic material is injection molded to form the partition member easily. In addition, the high-elastic material and the low-elastic material can be bonded to each other without using an adhesive because the base polymer is the same and has good compatibility, and the thermoplastic resin is used as the skeleton part. Therefore, the partition member including the orifice wall can be made to have high rigidity, and as a result, stable vibration isolation characteristics can be obtained.

  According to <2>, since the base polymer is PP (polypropylene) or PA (polyamide), the partition member can be made inexpensive and the moldability is good, so that the yield can be improved. it can.

  <3> According to <3>, since the surface area of the covering portion is 90% or more of the surface area of the partition member, almost the entire surface of the partition member in contact with both liquid chambers can be covered with the covering portion. The water hammer pressure resulting from the can be effectively attenuated.

  <4> If the thickness of the covering portion is 0.5 to 5 mm, and the thickness is less than 0.5 mm, the water hammer pressure cannot be sufficiently attenuated and reduced to 5 mm. In the case of exceeding the above, it is not preferable in terms of cost, space, and weight, and in the case where the total thickness of the partition member is made constant, the skeleton portion is made thinner by the thickening of the covering portion. As a result, the rigidity of the partition member is lowered, the vibration-proof characteristic is unstable, and further, the caulking of the outer cylinder member 2 with respect to the partition member 4 is unnecessarily softened.

  <5> According to <5>, on the side of the partition member facing the main liquid chamber, a membrane that accommodates a membrane configured to selectively vibrate with respect to an input having a predetermined frequency or more to form a flow path therearound. In addition to providing the storage chamber, an opening communicating with the secondary liquid chamber is provided on the bottom surface of the membrane storage chamber, and the covering portion is also provided on the surface of the membrane storage chamber, so that the membrane vibrates in the membrane storage chamber. Thus, it is possible to suppress the generation of abnormal noise when hitting the surroundings.

  According to <6>, a pressing plate that closes the membrane housing chamber in a state in which the membrane is accommodated is attached to the partition member, and an opening that allows fluid communication between the main liquid chamber and the membrane housing chamber is attached to the pressing plate. Since the hole is formed, it is possible to increase the rigidity of the partition member in the vicinity of the storage chamber and prevent the vibration-proof performance from becoming unstable due to the deformation.

  According to <7>, since the partition member is formed by injecting the low elastic material into a cavity of a covering portion molding die in which a molded skeleton portion is inserted, and curing it in the die, the cost is low. This can be formed and high productivity can be achieved.

  According to <8>, a valve body protruding from the partition member main body into the opening is provided in the opening of the partition member that communicates from the main liquid chamber to the orifice formed in the partition member. Since it is elastically deformed due to the pressure difference between the main liquid chamber and the orifice and a part of the flow path of the orifice is expanded and contracted, when the main liquid chamber suddenly rises in pressure, the valve body is elastically deformed and the orifice Since the flow path is narrowed, the change in the liquid volume in the main liquid chamber can be suppressed, and the decrease in the liquid pressure (negative pressure) in the main liquid chamber during rebound, which causes cavitation, can be suppressed. Since it is configured integrally with the partition member main body, it is possible to prevent the generation of abnormal noise in comparison with the point of cost and the case where it is configured of metal.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing the liquid-filled vibration isolator of this embodiment in a cross section passing through its central axis. The liquid-filled vibration isolator 10 includes a central member 1 positioned at the center, and a central member 1. A cylindrical member 2 arranged on the outer side in the radial direction and a rubber member 3 for connecting the members 1 and 2 between the members 1 and 2 are provided. A partition member 4 attached in a liquid-tight manner to the shaped member 2 is disposed, a main liquid chamber 6 is formed between the partition member 4 and the rubber member 3, and the partition member 4 of the main liquid chamber 6 is sandwiched A membrane member 5 is provided on the opposite side, a secondary liquid chamber 7 is formed between the membrane member 5 and the partition member 4, and these liquid chambers 6, 7 communicate with each other through an orifice 8 formed in the partition member 4. Configured so that the center member 1 and the cylindrical member 2 have an orifice relative to the axial relative displacement. 8 can obtain a desired vibration damping capability by the resonance action of the liquid passing through the.

  Further, in the liquid-filled vibration isolator 10 configured as described above, when the vibration input exceeds a predetermined frequency, the main liquid chamber 6 and the auxiliary liquid are passed through the orifice 8 due to a response delay due to the viscosity of the liquid. Since the liquid cannot be moved between the chamber 7 and the sub liquid chamber 7 on the side of the partition member 4 facing the sub liquid chamber 7 in order to enable the liquid to move even in response to vibration input in the high frequency region. It is preferable to form a membrane accommodating chamber 9 having an opening 12 that allows fluid communication with the membrane 7 and accommodate the membrane 11 therein. Further, the membrane accommodating chamber 9 is closed while the membrane 11 is accommodated. It is preferable that the holding plate 13 to be attached is attached to the partition member 4 and the holding plate 13 is formed with an opening hole 14 that allows the liquid communication between the main liquid chamber 6 and the membrane storage chamber 9.

  The membrane 11 arranged in this way is made of, for example, a plate-like rubber material, vibrates with respect to a high frequency input of a predetermined frequency or more, and between the membrane 11 and the bottom surface of the membrane housing chamber 9 or between the membranes. 11 and the pressing plate 13, a gap that is not formed in a state where it does not vibrate is formed. Thus, from the opening 14 of the pressing plate 13, the outer peripheral surface of the membrane 11 and the inner peripheral surface of the membrane housing chamber 9 are formed. A flow path is formed through the gap 15 between the main liquid chamber 6 and the sub liquid chamber 7 through the gap 15 between the main liquid chamber 6 and the sub liquid chamber 7. Therefore, it is possible to obtain good vibration isolation characteristics even in a high frequency region.

  2 is a cross-sectional view showing the partition member 4, and FIG. 3 is a plan view of the partition member 4. The present invention is characterized in that the partition member 4 includes a skeleton 21 made of a highly elastic material, The cover portion 22 is configured to cover the skeleton portion 21 with a low-elasticity material having lower elasticity than the high-elasticity material. A thermoplastic resin is used as the high-elasticity material of the skeleton portion 21, and the low elasticity of the cover portion 22 is used. As the material, a thermoplastic elastomer having the same high-elasticity resin and the same base polymer is used. In FIG. 3, 18 denotes an opening that leads from the main liquid chamber 6 to the orifice 8, and 19 denotes an opening that leads from the orifice 8 to the sub liquid chamber 7.

  In this way, the partition member 4 is made sufficiently rigid by constituting the skeleton portion 21 with a resin of a highly elastic material, so that the deformation of the partition member 4 including the orifice forming portion is suppressed and the vibration isolation effect is stabilized. Further, the covering portion 22 made of a low elastic elastomer that covers the skeleton portion 21 attenuates the energy of the water hammer pressure accompanying the disappearance of bubbles generated in the vicinity of the partition member 4 in the main liquid chamber 6 due to the cavitation phenomenon. It is possible to relax and advantageously suppress abnormal noise and abnormal vibration caused by this.

  Here, the base polymer is preferably PPS (polyphenylene sulfide), PP (polypropylene), or PA (polyamide), and these materials are advantageous because they are inexpensive and have good moldability.

  The surface area of the covering portion 22 is preferably 90% or more of the surface area of the partition member 4. By doing so, all the portions of the partition member 4 that are in contact with the liquid can be covered, and abnormal noise and abnormal vibration can be covered. Can be more effectively suppressed.

  Further, the thickness of the covering portion is preferably 0.5 mm or more in order to effectively attenuate and reduce the energy of the water hammer pressure, and the thickness is in terms of cost, space, and weight. In such a case, it is preferable to reduce the water hammer pressure energy as much as possible under the condition that the energy of the water hammer pressure can be effectively attenuated and relaxed.

  It is preferable to dispose the covering portion on the surface of the membrane housing chamber 9 to suppress abnormal noise generated when the membrane 11 hits the surrounding wall surface.

  In order to form such a partition member 4, the following is advantageous in terms of cost. That is, a highly elastic material is injected into the cavity of the skeleton part forming mold and cured in the mold to form the skeleton part 21 as shown in FIG. 4, and then for the covering part forming as shown in FIG. The molded skeleton part 21 is inserted into the mold 31, and a low elastic material is injected into the cavity space 32 formed between the inside of the mold 31 and the inserted skeleton part 21 and cured to cover the coated part. The partition member 4 composed of the skeleton part 21 covered with 22 is preferably formed.

  Here, in order to form the cavity space 32 having a predetermined thickness between the molded skeleton part 21 and the inside of the mold 31, a plurality of small protrusions 33 that support the skeleton part 21 are provided inside the mold 31. Alternatively, a protrusion (not shown) may be provided on the skeleton portion 21 instead.

  In this way, the partition member 4 can be formed at a low cost by two-color molding. Further, in the present invention, the high elastic material constituting the skeleton part and the low elastic material constituting the covering part 22 are formed. Since the base polymer is the same, the bonding of these materials can be ensured.

  Here, it is preferable that the presser plate 13 is made of a low elastic material having a lower elasticity than the high elastic material, thereby effectively attenuating and mitigating the water hammer pressure accompanying the cavitation phenomenon.

  Further, the attachment of the pressing plate 13 to the partition member 4 is performed by integrally forming the protrusions 23 at a plurality of locations on the surface of the partition member 4 that receives the pressing plate 13 with the same material as the skeleton portion 21. It is preferable to form a through hole 25 through which the protrusion 23 passes, and after fixing the protrusion 23 into the through hole 25, the tip 24 of the protrusion 23 is melted by ultrasonic waves or heat and fixed by crimping. In addition, the pressing plate 13 can be attached to the partition member 4 without deforming the partition member 4.

  In the above, the case where the liquid-filled vibration isolator 10 has the membrane 13 has been described. However, the liquid-filled vibration isolator may not include the membrane, and in this case, as shown in the cross-sectional view of FIG. The member 44 is composed of a skeleton portion 41 and a covering portion 42 covering the skeleton portion 41, the skeleton portion 41 is composed of a highly elastic thermoplastic resin, and the covering portion 42 has a low elasticity that is lower in elasticity than the highly elastic resin material. By using thermoplastic elastomer and making these base polymers the same, it is possible to effectively suppress abnormal noise and abnormal vibration associated with the cavitation phenomenon at low cost.

  FIG. 7 is a plan view of a partition member shown as a modification of the embodiment corresponding to FIG. 3 of the embodiment. FIG. 8 is a plan view and a cross-sectional view showing the vicinity of the opening in a normal state. FIG. 9 is a plan view and a cross-sectional view showing the vicinity of the opening in a state where the pressure of the main liquid chamber is increased, and the partition member 4 is formed in the opening 18A of the partition member 4 leading from the main liquid chamber 6 to the orifice 8. A valve body 17 protruding from the partition member 4 is provided so as to be integrated with the partition member 4. Normally, the liquid passes through an opening other than the valve body 17, but the liquid enters and exits the orifice 8. When the pressure in the main liquid chamber 6 suddenly increases compared to the inside, the valve body 17 is elastically deformed by the differential pressure, and the valve body 17 is located in the center in the width direction of the flow path of the orifice 8 as shown in FIG. You can close the part and narrow the channel Is configured, thereby, suppress the variation of the amount of liquid in the main liquid chamber, causing cavitation, it can contribute to suppress the main liquid chamber of the liquid pressure drop during rebound (negative pressure).

  In the figure, reference numeral 19 denotes an opening that leads from the orifice 8 to the secondary liquid chamber 7.

  The liquid filled type vibration damping device according to the present invention can be used as an engine mount or body mount of an automobile.

It is sectional drawing which shows the liquid enclosure type vibration isolator of embodiment which concerns on this invention. It is sectional drawing which shows a partition member. It is a top view which shows a partition member. It is sectional drawing which shows the frame | skeleton part of a partition member. It is sectional drawing which shows the metal mold | die for coating | coated part formation of the state which inserted the frame | skeleton part. It is sectional drawing which shows the partition member of another aspect. It is a top view which shows the partition member of the liquid enclosure type vibration isolator of the modification of embodiment which concerns on this invention. It is the top view and sectional drawing which show the opening part vicinity of the partition member of the modification of embodiment in a normal state. It is the top view and sectional drawing which show the opening part vicinity of the partition member of the modification of embodiment in the state in which the pressure of the main liquid chamber increased.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Center member 2 Cylindrical member 3 Rubber member 4 Partition member 5 Membrane member 6 Main liquid chamber 7 Sub liquid chamber 8 Orifice 9 Membrane storage chamber 10 Liquid enclosure type vibration isolator 11 Membrane 12 Opening formed in the membrane storage chamber 13 Press plate 14 Opening portion formed in press plate 15 Clearance between outer peripheral surface of membrane and inner peripheral surface of membrane accommodating chamber 17 Valve body 18, 18A Opening portion 19 Opening portion 21 Skeletal portion 22 Covering portion 23 Partition member Protrusions 24 Protrusions tips 25 Through holes in pressing plate 31 Mold 32 Cavity space 33 Small protrusions supporting the skeleton part 41 Skeleton part 42 Covering part 44 Partition member

Claims (8)

A center member, a cylindrical member disposed radially outside the center member, and a rubber member disposed between the members and connecting the members to each other, and one axial side of the rubber member In addition, a partition member that is liquid-tightly attached to the cylindrical member is disposed, and a main liquid chamber is formed between the partition member and the rubber member, and the partition member of the main liquid chamber is sandwiched between the partition member and the rubber member. A membrane member is provided on the opposite side, a secondary liquid chamber is formed between the membrane member and the partition member, and these liquid chambers communicate with each other through an orifice formed in the partition member. In a liquid-filled vibration isolator constituted by a skeleton portion made of a highly elastic material and a covering portion that covers the skeleton portion with a low elastic material having lower elasticity than the high elastic material,
A liquid-filled vibration isolator using a thermoplastic resin as the high elastic material and a thermoplastic elastomer having the same base polymer as the high elastic resin as the low elastic material.   The liquid filled vibration isolator according to claim 1, wherein the base polymer is PP (polypropylene) or PA (polyamide). The liquid-filled vibration isolator according to claim 1 or 2, wherein a surface area of the covering portion is 90% or more of a surface area of the partition member.   The liquid filled type vibration damping device according to claim 1, wherein the covering portion has a thickness of 0.5 to 5 mm.   On the side of the partition member facing the main liquid chamber, there is disposed a membrane storage chamber for storing a membrane configured to selectively vibrate with respect to an input of a predetermined frequency or more to form a flow path around it. 5. A liquid-filled type protection according to claim 1, wherein an opening communicating with the sub liquid chamber is provided on the bottom surface of the membrane housing chamber, and the covering portion is also disposed on the surface of the membrane housing chamber. Shaker.   A holding plate for closing the membrane housing chamber in a state in which the membrane is housed is attached to the partition member, and an opening hole is formed in the holding plate to allow communication between the main liquid chamber and the membrane housing chamber. Item 6. A liquid-filled vibration isolator according to any one of Items 1 to 5.   The said partition member is formed by inject | pouring the said low elastic material into the cavity of the metal mold | die for coating | coated part in which the shape | molded frame | skeleton part was inserted, and making it harden | cure in a metal mold | die. Liquid-filled vibration isolator.   A valve body is provided at the opening of the partition member that communicates with the orifice formed in the partition member from the main liquid chamber, and protrudes into the opening integrally from the partition member main body. The liquid-filled vibration isolator according to any one of claims 1 to 7, which is configured to be elastically deformed by a pressure difference in the orifice so as to expand and contract a part of the flow path of the orifice.

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