JP2008185152A - Fluid filled vibration absorbing device and engine mount using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel fluid filled vibration absorbing device simply constructed and tuned to stably reduce or avoid the occurrence of abnormal sounds and vibration which may result from negative pressure in a pressure receiving chamber. <P>SOLUTION: A partition member 38 uses an annular supporting metal fitting 40 with its center hole closed with a movable rubber film 56 and its outer peripheral edge supported by a second mounting bracket 14. On the other hand, an elastic rubber wall 64 protruding to a balancing chamber 82 and extending in the peripheral direction is formed at the outer peripheral edge of the movable rubber film 56 integrally with the movable rubber film 56, and an orifice passage 84 extending in the peripheral direction is formed on the outer periphery of the elastic rubber wall 64. When the movable rubber film 56 is elastically deformed toward the pressure receiving chamber 80, the torsion of the movable rubber film 56 is transmitted to the elastic rubber wall 64 to make the orifice passage 84 short-circuited to the balancing chamber 82. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vibration isolator that is suitably employed as, for example, an automobile engine mount and the like, and in particular, a fluid-filled anti-vibration system that obtains a vibration-proof effect based on the flow action of an enclosed incompressible fluid. The present invention relates to a vibration device.

  2. Description of the Related Art As a type of vibration isolator interposed between members constituting a vibration transmission system, a fluid-filled vibration isolator using a vibration isolating effect based on a flow action of an enclosed incompressible fluid has been known. Yes. The fluid-filled vibration isolator includes, for example, a first attachment member attached to one member to be anti-vibrated and a second attachment member attached to the other member to be anti-vibration connected by a main rubber elastic body. A pressure receiving chamber that is elastically connected and on both sides of the partition member supported by the second mounting member, a part of the wall portion is made of a main rubber elastic body, and an internal pressure fluctuation is caused at the time of vibration input; An orifice passage in which a part of the wall portion is formed of a flexible membrane and forms an equilibrium chamber whose volume is allowed to change by elastic deformation of the flexible membrane, and the pressure receiving chamber and the equilibrium chamber communicate with each other The structure is provided. In such a fluid-filled vibration isolator, an effective vibration isolating effect based on a fluid action such as a resonance action of a fluid that flows between the two chambers through the orifice passage is effective for vibration in the tuning frequency range of the orifice passage. For example, it has been suitably employed as an engine mount for automobiles.

  By the way, in the fluid-filled vibration isolator, when a shocking large load is input between the first mounting member and the second mounting member, abnormal noise and vibration that may be felt may occur. Such abnormal noise and vibration are considered to be caused by the occurrence of local negative pressure in the pressure receiving chamber. That is, when a large negative pressure is generated locally in the pressure receiving chamber, the gas dissolved in the enclosed incompressible fluid is separated, and bubbles that are understood as cavitation are formed. The water hammer pressure generated when the bubbles collapse is transmitted to the vehicle body via the first and second mounting members, etc., so that the above-mentioned abnormal noise and vibration are generated. It is.

  Therefore, for the purpose of solving such a problem, in Patent Document 1 (Japanese Patent Publication No. 7-107416), a movable rubber film is provided on a partition member that partitions the pressure receiving chamber and the equilibrium chamber, and the movable rubber film is provided. A structure has been proposed in which a notch is provided. According to this, when the relative pressure difference between the pressure receiving chamber and the equilibrium chamber becomes large, the notch formation portion is opened, and the fluid flows in the pressure receiving chamber and the equilibrium chamber through the opening portion. As a result, the negative pressure generated in the pressure receiving chamber is eliminated as quickly as possible, and abnormal sounds and vibrations that may be caused by cavitation can be reduced or avoided.

  However, in such a structure described in Patent Document 1, since a notch is opened even when a positive pressure fluctuation is generated in the pressure receiving chamber, the internal pressure of the pressure receiving chamber is increased by fluid flow through the notch. There is a risk of escaping to the equilibrium chamber. Therefore, it may be difficult to effectively obtain the amount of fluid flow through the orifice passage, which may make it difficult to achieve the desired vibration isolation performance.

  In addition, in the patent application 2 (Japanese Patent Laid-Open No. 2003-148548), which is the previous application, the present applicant switches between a short-circuit channel that short-circuits the orifice passage to the pressure-receiving chamber, and a communication state and a cut-off state of the short-circuit channel. A fluid-filled vibration isolator with a valve body has been proposed. In the fluid-filled vibration isolator described in Patent Document 2, when an excessive negative pressure is generated in the pressure receiving chamber, the valve body is deformed by a suction force exerted on the valve body due to the negative pressure in the pressure receiving chamber. By separating the opening from the opening of the short-circuit channel, the short-circuit channel is brought into a communication state, and the negative pressure in the pressure-receiving chamber is eliminated by flowing the sealed fluid from the equilibrium chamber side into the pressure-receiving chamber through the short-circuit channel. ing.

  However, as a result of further studies and experiments by the present inventor, it has become clear that there is still room for improvement in the fluid-filled vibration isolator described in Patent Document 2. That is, in the valve body formed of a thin rubber elastic body as shown in Patent Document 2, there is a possibility that cracks and the like may occur due to repeated opening and closing operations, and sufficient durability depending on the use environment or the like. It may be difficult to achieve. Further, in the structure described in Patent Document 2, the valve body is formed of a relatively small rubber elastic body, and accordingly, the area where the negative pressure in the pressure receiving chamber acts on the valve body is small. Therefore, it is necessary to tune the spring constant and the like of the valve body with high accuracy, and it may be difficult to stably realize the opening / closing operation of the valve body at the set negative pressure depending on a manufacturing error or the like.

Japanese Patent Publication No. 7-107416 JP 2003-148548 A

  Here, the present invention has been made in the background as described above, and the problem to be solved is that the generation of abnormal noise and vibration considered to be caused by the negative pressure in the pressure receiving chamber is simplified. It is an object of the present invention to provide a fluid-filled vibration isolator having a novel structure that can be stably reduced or avoided by the structure and tuning.

  Hereinafter, the aspect of this invention made | formed in order to solve such a subject is described. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible. Further, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or an invention that can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized based on thought.

  That is, according to the present invention, the first attachment member attached to one member to be vibration-proof connected and the second attachment member attached to the other member to be vibration-proof connected to each other by the main rubber elastic body. In addition, on both sides of the partition member supported by the second mounting member, a pressure receiving chamber in which a part of the wall part is configured by the main rubber elastic body, and a part of the wall part is a flexible membrane A fluid-filled vibration isolating device in which an incompressible fluid is sealed in the pressure receiving chamber and the equilibrium chamber, and an orifice passage is provided to communicate the pressure receiving chamber and the balance chamber with each other. The partition member is configured by using a ring-shaped support fitting, closing the center hole of the support fitting with a movable rubber film, and supporting the outer peripheral edge of the support fitting with the second mounting member. On the other hand, at the outer peripheral edge of the movable rubber film, the equilibrium An elastic rubber wall protruding in the circumferential direction and extending in the circumferential direction is formed integrally with the movable rubber film, and the orifice passage extending in the circumferential direction is formed on the outer peripheral side of the elastic rubber wall, so that the movable rubber film is in the pressure receiving chamber When the elastic rubber film is elastically deformed to the side, the distortion of the movable rubber film is transmitted to the elastic rubber wall, so that the orifice passage is short-circuited to the equilibrium chamber.

  In such a fluid-filled vibration isolator having a structure according to the present invention, when a shocking vibration load is input between the first mounting member and the second mounting member, it is generated in the pressure receiving chamber. Negative pressure can be reduced. That is, according to the present invention, when a large negative pressure is generated in the pressure receiving chamber, the negative pressure in the pressure receiving chamber acts on the movable rubber film, so that the movable rubber film is elastically deformed to be sucked and displaced toward the pressure receiving chamber. It is done. Then, the strain due to the elastic deformation of the movable rubber film is transmitted to the elastic rubber wall integrally formed with the movable rubber film, so that the elastic rubber wall is elastically deformed. As a result, the elastic rubber wall cannot substantially constitute the wall portion of the orifice passage on the equilibrium chamber side, and the orifice passage is short-circuited to the equilibrium chamber at the circumferential intermediate portion thereof. Thus, when an excessive negative pressure is generated in the pressure receiving chamber, the amount of fluid flowing between the pressure receiving chamber and the equilibrium chamber increases due to a short circuit of the orifice passage to the equilibrium chamber, and the negative pressure in the pressure receiving chamber is reduced. It is quickly reduced or eliminated. Therefore, it is possible to effectively reduce or avoid abnormal noise and vibration that are considered to be caused by cavitation.

  Moreover, according to the structure according to the present invention, the movable rubber film provided with the elastic rubber wall functioning as a valve body for switching the short-circuited state and the non-short-circuited state of the orifice passage so as to close the central hole of the annular reinforcing metal fitting. It can be elastically deformed along with the deformation. Therefore, it is possible to use a relatively thick rubber elastic body as the elastic rubber wall, and it is possible to achieve both improvement of the durability of the valve body and a stable negative pressure elimination effect.

  In the fluid-filled vibration isolator according to the present invention, the elastic rubber wall includes a reinforcing rod integrally formed with the support fitting at a portion where the opening to the pressure receiving chamber side of the orifice passage is located. The wall can be fixed.

  According to such a structure, the rigidity of the elastic rubber wall can be increased by fixing the reinforcing collar wall to the elastic rubber wall in the vicinity of the opening on the pressure receiving chamber side of the orifice passage. As a result, the elastic rubber wall can be effectively prevented from being elastically deformed in the vicinity of the opening on the pressure receiving chamber side of the orifice passage during normal vibration input, and the vibration isolation effect based on the fluid flow through the orifice passage can be achieved. It can be obtained effectively.

  In the fluid filled type vibration isolator according to the present invention, it is desirable that the movable rubber film is integrally formed with the elastic rubber wall so as to extend from an intermediate portion in the height direction of the elastic rubber wall.

  According to this, the elastic deformation of the elastic rubber wall is advantageously caused by the elastic deformation of the movable rubber film due to the excessive negative pressure in the pressure receiving chamber, and the abnormal noise and vibration due to cavitation can be effectively reduced. I can do it. The height direction of the elastic rubber wall refers to the protruding direction of the elastic rubber wall that protrudes toward the equilibrium chamber.

  Furthermore, in the fluid-filled vibration isolator having a structure according to the present invention, a structure in which the outer peripheral portion of the movable rubber film is a tapered portion that gradually inclines toward the equilibrium chamber side toward the outer peripheral side can be suitably employed. .

  Thereby, when the movable rubber film is sucked and displaced toward the pressure receiving chamber, elastic deformation of the elastic rubber wall can be advantageously caused. Therefore, it is possible to stably realize a short circuit of the orifice passage when a negative pressure is generated in the pressure receiving chamber. Therefore, cavitation noise can be effectively reduced or avoided.

  In the fluid-filled vibration isolator according to the present invention, a structure in which a thin portion is provided on at least a part of the circumference of the elastic rubber wall may be employed.

  By adopting such a structure, the elastic rubber wall can be deformed relatively easily in the thin portion. Therefore, when a negative pressure with an absolute value exceeding a preset value is generated in the pressure receiving chamber, the orifice passage is effectively short-circuited, generating abnormal noise and vibration that may be caused by cavitation. Can be reduced or avoided more advantageously.

  Further, in the fluid filled type vibration damping device according to the present invention, when the structure as described above is adopted, a recess may be formed in the middle portion in the height direction of the thin portion in the elastic rubber wall.

  By adopting such a structure, it is possible to make the elastic rubber wall elastically deformed more advantageously by partially thinning the elastic rubber wall at the location where the recess is formed. Therefore, when a negative pressure is generated in the pressure receiving chamber, the short-circuiting of the orifice passage can be effectively realized, and abnormal noise and vibration considered to be caused by cavitation can be effectively reduced or avoided.

  Further, the present invention uses the fluid-filled vibration isolator according to any one of claims 1 to 6 to attach the first attachment member to one of the power unit and the vehicle body, and to In an engine mount that is interposed between the power unit and the vehicle body and supports the vibration of the power unit against the vehicle body by attaching an attachment member to the other of the power unit and the vehicle body, The tuning frequency is set to a low frequency range corresponding to an engine shake input in a normal running state, and the elastic rubber wall partitions the equilibrium chamber and the orifice passage when the engine shake is input in a normal running state The elastic rubber wall is elastically deformed when a shocking heavy load is input. Also characterized in that the orifice passage has to be made to short-circuit the equilibrium chamber in the area where the elastic rubber wall

  In such an engine mount having a structure according to the present invention, when normal vibration is input, an engine shake that tends to cause a problem in the running state of the vehicle due to a high damping effect based on a fluid action such as a resonance action of a fluid that flows through the orifice passage. Effective anti-vibration effect is exhibited. On the other hand, when a shocking heavy load is input between the first mounting member and the second mounting member, for example, when overcoming a step, the movable rubber film receives the pressure by the negative pressure induced in the pressure receiving chamber. By being sucked to the chamber side, the elastic rubber wall that is integrally formed with the movable rubber film and forms a part of the wall portion of the orifice passage is elastically deformed by transmitting the distortion of the movable rubber film. The orifice passage is communicated with the equilibration chamber at an intermediate portion in the passage length direction. As a result, when a large negative pressure is generated in the pressure receiving chamber by a shocking large load input, the amount of fluid flowing through the orifice passage can be increased, and the negative pressure in the pressure receiving chamber can be made as much as possible. It is possible to eliminate it promptly.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  1 and 2 show an automobile engine mount 10 as an embodiment of the present invention. The engine mount 10 has a structure in which a first mounting bracket 12 as a first mounting member and a second mounting bracket 14 as a second mounting member are connected to a main rubber elastic body 16. The mounting bracket 12 is mounted on the power unit side (not shown), and the second mounting bracket 14 is mounted on the vehicle body side (not shown), so that the power unit is supported on the vehicle body in a vibration-proof manner. In the following description, in principle, the vertical direction refers to the vertical direction in FIG. 1 that is the substantially vertical direction when mounted on the vehicle and is the main vibration load input direction. 1 and 2 show a state in which the engine mount 10 is not attached.

  More specifically, the first mounting member 12 has a substantially cylindrical shape, and a flange portion 18 that extends radially outward is integrally formed at the upper end in the axial direction. Also, a bolt hole 20 that opens upward is formed on the central axis of the first mounting bracket 12, and a fixing bolt (not shown) is screwed into the bolt hole 20, whereby the first mounting bracket 12 is fixed to a power unit (not shown).

  Further, the second mounting bracket 14 has a thin-walled, large-diameter, generally cylindrical shape. The opening at the lower end in the axial direction has a stepped portion that extends radially outward and an axial direction from the outer peripheral edge of the stepped portion. A caulking piece 22 extending downward is integrally provided. Further, in the present embodiment, a bracket (not shown) is fitted and fixed to the second mounting bracket 14, and the second mounting bracket 14 is fixed by fixing the bracket to a vehicle body (not shown). It is designed to be fixed to the vehicle body.

  The first mounting bracket 12 and the second mounting bracket 14 are disposed on the same central axis. In the present embodiment, the first mounting bracket 12 is located above the second mounting bracket 14 in the axial direction. Are spaced apart from each other. A main rubber elastic body 16 is disposed between the first mounting bracket 12 and the second mounting bracket 14.

  The main rubber elastic body 16 has a generally frustoconical shape as a whole, and a large-diameter circular recess 24 that opens downward in the axial direction is formed on a lower end surface that is an end surface on the large-diameter side. Yes. The first mounting bracket 12 is embedded in the upper end that is the small-diameter side end of the main rubber elastic body 16, and the flange portion 18 is overlaid on the upper end surface of the main rubber elastic body 16. Is attached to the end portion of the main rubber elastic body 16 on the small diameter side by vulcanization. Further, the second mounting bracket 14 is larger than the main rubber elastic body 16 in a state where the second mounting bracket 14 is extrapolated with respect to the lower end that is the large-diameter side end of the main rubber elastic body 16. It is vulcanized and bonded to the outer peripheral surface of the radial end. As is clear from the above, in the present embodiment, the main rubber elastic body 16 is formed as an integrally vulcanized molded product including the first mounting bracket 12 and the second mounting bracket 14.

  In addition, a diaphragm 26 as a flexible film is assembled in the opening portion on the lower side in the axial direction of the second mounting bracket 14. The diaphragm 26 is formed of a thin rubber elastic body, and has a substantially circular dome shape that has sufficient slack and is easily deformed. A fixing metal fitting 28 is vulcanized and bonded to the outer peripheral edge of the diaphragm 26. The fixture 28 has a thin, large-diameter, generally cylindrical shape, and has a stepped shape having a step portion 30 at an axially intermediate portion. In addition, the upper side in the axial direction with a stepped portion 30 is a tapered cylindrical shape that gradually increases in diameter upward, and the lower side in the axial direction is a cylindrical shape that extends in the axial direction. In addition, a fixing flange portion 32 that extends radially outward is integrally formed in the upper end opening of the fixing bracket 28 over the entire circumference. Further, the outer peripheral edge of the diaphragm 26 is vulcanized and bonded to the lower end of the fixing metal 28, and the outer peripheral surface and inner peripheral surface of the fixing metal 28 are covered with a covering rubber layer 34 formed integrally with the diaphragm 26. It has been broken. The covering rubber layer 34 is formed so as to cover substantially the entire inner peripheral surface and outer peripheral surface of the fixture 28. Also, the covering rubber layer 34 is not formed on the fixing flange portion 32 formed integrally with the upper end portion of the fixing fitting 28, and the fixing flange portion 32 is exposed to the outside.

  Such a diaphragm 26 is assembled to the lower end portion in the axial direction of the second mounting bracket 14. That is, the fixing flange portion 32 of the fixing fitting 28 is caulked and fixed by the caulking piece 22 provided at the lower end portion of the second attachment fitting 14, and the fixing fitting 28 is fixedly supported by the second attachment fitting 14. Thus, the diaphragm 26 is disposed so as to cover the opening portion on the lower side in the axial direction of the second mounting bracket 14. Accordingly, the opening on the upper side in the axial direction of the second mounting bracket 14 is fluid-tightly closed by the main rubber elastic body 16, and the opening on the lower side in the axial direction of the second mounting bracket 14 is a diaphragm 26. A fluid-tight region 36 that is sealed from the outside is formed between the main rubber elastic body 16 and the diaphragm 26 on the inner peripheral side of the second mounting member 14. ing.

  In addition, an incompressible fluid is sealed in the fluid sealing region 36. In addition, although it does not specifically limit as this sealed fluid, Water, alkylene glycol, polyalkylene glycol, silicone oil, what mixed them, etc. are employ | adopted suitably. Furthermore, it is desirable to employ a low-viscosity fluid having a viscosity of 0.1 Pa · s or less in order to advantageously obtain an anti-vibration effect based on the fluid flow action described later.

  Furthermore, a partition member 38 is accommodated in the fluid sealing region 36. As shown in FIGS. 3 to 5, the partition member 38 has a thick disk shape as a whole, and in this embodiment, the partition member body 42 is fixed to the support metal fitting 40. Has been.

  As shown in FIGS. 6 and 7, the support fitting 40 has a thin annular plate shape as a whole. The support fitting 40 is formed with a reinforcing portion 44 extending toward the inner peripheral side at a part of the periphery. The reinforcing portion 44 is provided with a length of about 1/6 in the circumferential direction, and is bent from the horizontal plate portion 46 extending in the direction perpendicular to the axis, and the inner peripheral edge of the horizontal plate portion 46, and downward in the axial direction. It has a vertical plate portion 48 as an extending reinforcing wall. In addition, a communication hole 50 is provided in the horizontal plate portion 46 at a substantially central portion in the circumferential direction. Furthermore, in the present embodiment, the lower end portion of the vertical plate portion 48 is slightly curled to the inner peripheral side and reinforced.

  Furthermore, the support metal fitting 40 is integrally formed with a reinforcing rib 52 whose inner peripheral edge protrudes upwardly in a curled shape. The reinforcing rib 52 is provided at a position different from the reinforcing portion 44 in the circumferential direction in the support fitting 40 and is formed to extend over a length of about 5/6 circumference in the circumferential direction. In the present embodiment, a pair of edge cut portions 54 are provided between the portion of the support fitting 40 where the reinforcing ribs 52 are formed and the circumferential direction of the reinforcing portion 44. The edge cut portion 54 is formed in the inner peripheral edge portion of the support fitting 40 with an arc-shaped cutout structure, whereby the formation of the reinforcing rib 52 is easily realized.

  Further, a partition member main body 42 formed of a rubber elastic body is vulcanized and bonded to the support fitting 40. The partition member main body 42 has a substantially disc shape, and includes a movable rubber plate portion 56 and an orifice forming portion 58 as a movable rubber film.

  More specifically, the movable rubber plate portion 56 is formed at the central portion of the partition member main body 42 and is provided so as to extend in a direction substantially perpendicular to the axis within the central hole of the annular support bracket 40. . In addition, the movable rubber plate portion 56 in the present embodiment has a substantially disc shape with a predetermined thickness that extends in the direction perpendicular to the axis of the movable rubber plate portion 56 and has a shape that gradually slopes downward as the outer peripheral portion goes to the outer peripheral side. It is set as the taper part 60, and the substantially dish shape of the reverse direction is exhibited as a whole.

  An orifice forming portion 58 is formed on the outer peripheral edge of the partition member main body 42. The orifice forming portion 58 has an annular shape that continuously extends over the entire circumference in the circumferential direction, and is integrally formed with the movable rubber plate portion 56 over the entire circumference on the outer peripheral side of the movable rubber plate portion 56. . In the present embodiment, the orifice forming portion 58 includes a plate-shaped pressure-receiving chamber-side partition wall portion 62 that extends in a direction perpendicular to the axis, and an equilibrium chamber-side partition wall portion 64 as a cylindrical elastic rubber wall that extends in the axial direction. It is configured. In the present embodiment, the central hole of the support fitting 40 is fluid-tightly closed by the cooperation of the movable rubber plate portion 56 and the orifice forming portion 58.

  The pressure-receiving chamber-side partition wall 62 is formed so as to extend with a length of a little less than one round in the circumferential direction, and has a substantially C shape in plan view as shown in FIG. Further, the pressure receiving chamber side partition wall portion 62 in the present embodiment is configured such that the position of the upper end surface thereof is the same position in the axial direction as the upper end surface of the central portion of the movable rubber plate portion 56.

  Further, the pressure receiving chamber side partition wall portion 62 is formed with concave grooves 66 at a plurality of locations on the circumference. The concave grooves 66 are formed so as to open downward in the axial direction on the lower surface of the pressure receiving chamber side partition wall portion 62 and extend in the radial direction. In the present embodiment, the concave grooves 66 are spaced apart from each other at substantially equal intervals. It is formed in three places on the circumference. In the present embodiment, the thickness in the axial direction of the pressure receiving chamber side partition wall portion 62 in the portion where the concave groove 66 is formed is substantially equal to the thickness of the central portion of the movable rubber plate portion 56.

  Further, as shown in FIG. 4, the equilibrium chamber side partition wall 64 has a substantially cylindrical shape extending in a predetermined length in the axial direction, and extends axially from the inner peripheral edge of the pressure receiving chamber side partition wall 62. It is formed so as to extend downward. The equilibrium chamber side partition wall 64 is formed of a rubber elastic body and is allowed to be elastically deformed. A communication window 68 is formed at one place on the circumference of the equilibrium chamber side partition wall 64. The communication window 68 is a notched window portion formed at the lower end edge of the equilibrium chamber side partition wall portion 64, and is continuously formed over the entire length in the radial direction of the equilibrium chamber side partition wall portion 64. As a result, the equilibrium chamber side partition wall 64 has a substantially C-shape as viewed from the bottom, as shown in FIG.

  Thin wall portions 70 as thin portions are provided at a plurality of locations on the periphery of the equilibrium chamber side partition wall portion 64. The thin wall portion 70 is a portion which is thinned by forming notches opened in the outer peripheral surface and the lower end surface in the equilibrium chamber side partition wall portion 64. In the present embodiment, the thin wall portion 70 is the pressure receiving chamber side partition wall portion 62. Aligned with the concave groove 66 formed in the circumferential direction in the circumferential direction, it is provided at three locations on the circumference. Further, as shown in FIG. 4, the thin wall portion 70 in the present embodiment is formed so as to gradually become narrower in the circumferential direction toward the upper side in the axial direction, and the upper end portion thereof is a groove 66. The lower end portion is formed with a larger circumferential dimension than the concave groove 66, and the concave groove 66 is positioned at the circumferential center of the thin wall portion 70. Are aligned with each other.

  Furthermore, in this embodiment, as shown in FIGS. 4 and 5, a recess 72 as a circular recess opening in the outer peripheral surface is provided in the intermediate portion in the height direction of the thin wall portion 70. In addition, at the location where the recess 72 is formed, the equilibrium chamber side partition wall 64 is thinner. In this embodiment, the recess 72 is configured with a substantially arc-shaped curved surface as a bottom surface. In the present embodiment, the recess 72 is formed at a substantially central portion in the height direction of the equilibrium chamber side partition wall portion 64. Further, the height direction of the thin wall portion 70 (equilibrium chamber side partition wall portion 64) is a protruding direction of the equilibrium chamber side partition wall portion 64 in a state in which the partition member 38, which will be described later, is assembled to the second mounting bracket 14. In this embodiment, the axial direction of the engine mount 10 is used.

  Further, the equilibrium chamber side partition wall portion 64 is integrally formed so as to extend downward from the inner peripheral edge portion of the pressure receiving chamber side partition wall portion 62, so that the outer peripheral side of the equilibrium chamber side partition wall portion 64 has a radial direction. A notched circumferential groove 74 is formed that opens outward and axially downward and extends in the circumferential direction. Further, in the present embodiment, the cutout circumferential groove 74 is partitioned by a peripheral end partition wall 76 integrally formed with the equilibrium chamber side partition wall 64 at one place on the periphery. The peripheral end partition wall 76 is a wall portion of a rubber elastic body having a substantially rectangular block shape and expanding radially outward, and is integrally formed at one end in the circumferential direction of the equilibrium chamber side partition wall 64. Yes. Thereby, the notch circumferential groove 74 is formed so as to continuously extend over a predetermined length of slightly less than one circumference in the circumferential direction, and both circumferential ends of the notched circumferential groove 74 are circumferential end partition wall portions 76 in the circumferential direction. It is designed to be positioned on both sides of the.

  Such an orifice forming portion 58 is provided integrally with the movable rubber plate portion 56. That is, the tapered portion 60 provided on the outer peripheral portion of the movable rubber plate portion 56 is formed so as to extend from the inner peripheral surface of the orifice forming portion 58, and the central hole of the orifice forming portion 58 having a substantially annular shape. Is closed by the movable rubber plate portion 56. Thereby, the substantially disc-shaped partition member main body 42 provided with the movable rubber plate portion 56 and the orifice forming portion 58 is formed. In the present embodiment, the tapered portion 60 of the movable rubber plate portion 56 is formed so as to extend from a substantially central portion in the height direction of the equilibrium chamber side partition wall portion 64.

  Such a partition member main body 42 is vulcanized and bonded to the support fitting 40. That is, the inner peripheral portion of the support fitting 40 is fixed in a state of being embedded in the orifice forming portion 58, and the partition member 38 is constituted by an integral vulcanization molded product of the partition member main body 42 provided with the support fitting 40. . More specifically, the support bracket 40 has an inner peripheral portion of the horizontal plate portion 46 fixed to the pressure-receiving chamber side partition wall portion 62 of the orifice forming portion 58 and an outer peripheral portion radially outward from the partition member main body 42. The fixing portion 78 is protruded in the direction. Further, the vertical plate portion 48 constituting the reinforcing portion 44 of the support fitting 40 is fixed to a part of the circumference of the equilibrium chamber side partition wall portion 64 of the orifice forming portion 58, and the vertical plate portion 48 is fixed. In the portion, the equilibrium chamber side partition wall 64 is reinforced and deformation is limited.

  The partition member 38 having such a structure is disposed so as to spread in the direction perpendicular to the axis in the fluid sealing region 36. That is, the partition member 38 has the fixing portion 78 of the support fitting 40 overlapped with the stepped portion provided at the lower end of the second mounting fitting 14 from below in the axial direction, together with the fixing flange portion 32 of the fixing fitting 28. It is fixed by caulking pieces 22. Thereby, the partition member 38 is fixedly supported by the second mounting bracket 14 and spreads in the direction perpendicular to the axis between the axial directions of the main rubber elastic body 16 and the diaphragm 26.

  Thus, by arranging the partition member 38 in the fluid sealing region 36, the fluid sealing region 36 is divided into two in the axial direction across the partition member 38. As a result, a pressure receiving chamber 80 in which a part of the wall portion is constituted by the main rubber elastic body 16 and an internal pressure fluctuation is generated when vibration is input is formed on the upper side in the axial direction, which is one side across the partition member 38. In addition, an equilibrium chamber in which a part of the wall portion is formed of the diaphragm 26 on the lower side in the axial direction, which is the other side across the partition member 38, and the volume change is easily allowed by elastic deformation of the diaphragm 26. 82 is formed.

  Further, in the present embodiment, under the attached state of the partition member 38, the equilibrium chamber side partition wall portion 64 is provided so as to extend downward on the side of the equilibrium chamber 82 in the axial direction. The lower end surface of the equilibrium chamber side partition wall 64 is overlapped with the stepped portion 30 formed at the intermediate portion in the axial direction of the fixture 28 from above. In the present embodiment, in the covering rubber layer 34 attached to the inner peripheral surface side of the fixing bracket 28, a portion located in the vicinity of the step portion 30 is relatively thick, and such a thick portion The lower end of the equilibrium chamber side partition wall 64 is overlapped with an annular overlapping surface formed on the upper surface of the inner peripheral edge of the inner wall.

  As a result, a tunnel-like passage is formed on the outer peripheral side of the equilibrium chamber-side partition wall 64 using the notched peripheral groove 74 and extending in a predetermined length of slightly less than one turn in the circumferential direction. The tunnel-shaped passage is partitioned from the pressure receiving chamber 80 by the pressure receiving chamber side partition wall portion 62 and from the equilibrium chamber 82 by the equilibrium chamber side partition wall portion 64. In the present embodiment, the equilibrium chamber side partition wall portion 64 is pressed against the stepped portion 30 of the fixing bracket 28, and the lower surface of the equilibrium chamber side partition wall portion 64 and the upper surface of the stepped portion 30 (the above-described annular overlap). Surface) is fluidly superimposed. Further, in the present embodiment, the contact force of the equilibrium chamber side partition wall 64 with the fixing bracket 28 (the thick portion of the covering rubber layer 34) is appropriately set. As described later, during normal vibration input, The contact state between the equilibrium chamber side partition wall portion 64 and the fixing bracket 28 is maintained, and when a negative pressure larger than the set value is generated in the pressure receiving chamber 80, the equilibrium chamber side partition wall portion 64 and the fixing bracket 28 are fixed. The contact state of the metal fitting 28 can be released.

  Further, one end in the circumferential direction of the tunnel-shaped passage formed using the cutout circumferential groove 74 is positioned between the circumferential ends of the pressure-receiving chamber side partition wall 62 having a substantially C shape in plan view. I'm hurt. Thereby, the lateral plate portion 46 of the support fitting 40 is exposed to the pressure receiving chamber 80 at one end in the circumferential direction of the tunnel-shaped passage. Further, a communication hole 50 is positioned in the horizontal plate portion 46 exposed in the pressure receiving chamber 80, and one end in the circumferential direction of the tunnel-shaped passage is communicated with the pressure receiving chamber 80. On the other hand, the other end in the circumferential direction of the tunnel-shaped passage is formed on the inner peripheral side of the tunnel-shaped passage sandwiching the equilibrium chamber-side partition wall portion 64 through the communication window 68 formed in the equilibrium chamber-side partition wall portion 64. The equilibrium chamber 82 is communicated.

  As described above, the tunnel-shaped passage extends on the outer circumferential side of the equilibrium chamber side partition wall 64 by a predetermined length in the circumferential direction, and the circumferential ends thereof are communicated with the pressure receiving chamber 80 and the equilibrium chamber 82, respectively. An orifice passage 84 is formed to allow the pressure receiving chamber 80 and the equilibrium chamber 82 to communicate with each other using the tunnel-like passage. In the present embodiment, the orifice passage 84 is set so that the tuning frequency at which the anti-vibration effect based on the fluid flow action is exhibited is in a low frequency range of about a dozen Hz corresponding to the engine shake of an automobile. . The tuning frequency of the orifice passage 84 can be set by adjusting the ratio between the passage length of the orifice passage 84 and the passage sectional area.

  When the engine mount 10 having such a structure according to the present embodiment is mounted on an automobile, the resonance action of the fluid that is caused to flow through the orifice passage 84 with respect to an engine shake that is likely to cause a problem during normal driving, etc. A high damping effect based on the fluid action is effectively exhibited, and good vibration isolation performance can be realized.

  Particularly in this embodiment, the vicinity of the communication hole 50, which is the opening of the orifice passage 84 on the pressure receiving chamber 80 side, is reinforced by the reinforcing portion 44. Thereby, the rigidity of the wall portion of the orifice passage 84 at the end portion of the orifice passage 84 on the pressure receiving chamber 80 side can be increased, and the elastic deformation of the wall portion near the end portion of the orifice passage 84 on the pressure receiving chamber 80 side is advantageously limited. Is done. Therefore, fluid fluctuations in the pressure receiving chamber 80 are effectively generated during normal vibration input, and the fluid through the orifice passage 84 is generated based on the relative pressure difference between the pressure receiving chamber 80 and the equilibrium chamber 82. The amount of flow is effectively ensured, and the anti-vibration effect based on the fluid flow action is advantageously exhibited.

  Further, at the time of vibration input in a frequency range higher than the frequency range corresponding to the engine shake, the movable rubber plate portion 56 is elastically slightly deformed so that the pressure fluctuation in the pressure receiving chamber 80 is reduced or absorbed. It has become. As a result, for example, a significant increase in the dynamic spring constant is prevented against idling vibration, which is a problem when the automobile is stopped, and vibrations in middle to high frequencies such as a booming noise which is a problem when traveling. Vibration performance can be obtained.

  Further, under the normal vibration input state as described above, the equilibrium chamber side partition wall 64 and the fixing fitting 28 are maintained in fluid-tight contact with each other via the covering rubber layer 34, and the orifice passage 84 is formed. The state is maintained in a fluid-tight partition from the equilibrium chamber 82. Therefore, the pressure fluctuation in the pressure receiving chamber 80 is advantageously ensured, the fluid flow through the orifice passage 84 can be advantageously produced, and the desired vibration isolation performance is advantageously obtained with respect to the normal input vibration. Can be obtained. The contact state between the equilibrium chamber side partition wall 64 and the fixing bracket 28 under such a normal vibration input state is such that the equilibrium chamber side partition wall 64 is positioned in the axial direction with respect to the fixing bracket 28 under a non-load input state. It can be advantageously realized by abutting in a pre-compressed state by a fixed amount.

  In addition, in the present embodiment, the vertical plate portion 48 formed integrally with the support fitting 40 is fixed to the equilibrium chamber side partition wall portion 64 in the vicinity of the circumferential end portion of the orifice passage 84, so that the end portion of the orifice passage 84 is obtained. The rigidity of the equilibrium chamber side partition wall 64 in the vicinity is high. Therefore, the elastic deformation of the equilibrium chamber side partition wall 64 in the vicinity of the opening of the orifice passage 84 on the pressure receiving chamber 80 side is limited, and a short circuit of the orifice passage 84 to the equilibrium chamber 82 is more advantageous during normal vibration input. It is to be prevented.

  In addition, when a shocking large load is input between the first mounting bracket 12 and the second mounting bracket 14 and a large negative pressure is generated in the pressure receiving chamber 80, the pressure receiving chamber 80 is balanced. Due to the relative pressure difference in the chamber 82, the movable rubber plate portion 56 is sucked toward the pressure receiving chamber 80, and the movable rubber plate portion 56 is deformed as shown by a two-dot chain line in FIG.

  Here, when the movable rubber plate portion 56 is elastically deformed, the distortion accompanying the deformation of the movable rubber plate portion 56 is transmitted to the orifice forming portion 58 integrally formed on the outer peripheral side of the movable rubber plate portion 56. The equilibrium chamber side partition wall portion 64 constituting the orifice forming portion 58 is elastically deformed. More specifically, as indicated by a two-dot chain line in FIG. 1, the balance chamber side partition wall portion 64 of the orifice forming portion 58 is entirely axial in accordance with the upward displacement of the movable rubber plate portion 56. When lifted upward, the abutting force on the fixture 28 is reduced. In the present embodiment, the lower end portion of the equilibrium chamber side partition wall portion 64 is deformed so as to displace radially inward at the location where the thin wall portion 70 is formed, and the orifice passage 84 is in the equilibrium chamber 82 at the circumferential intermediate portion. Can be short-circuited.

  As a result, the amount of fluid flowing through the orifice passage 84 increases due to the passage length of the orifice passage 84 being shortened to reduce the flow resistance, and the negative pressure induced in the pressure receiving chamber 80 is reduced. It is possible to resolve it promptly. Therefore, it is possible to reduce or avoid the generation of abnormal noise and vibration that are considered to be generated when the bubbles generated by the negative pressure in the pressure receiving chamber 80 collapse.

  In particular, in this embodiment, in order to advantageously realize the deformation of the equilibrium chamber side partition wall portion 64 accompanying the deformation of the movable rubber plate portion 56, the thin wall portions 70 are provided at a plurality of locations on the circumference of the equilibrium chamber side partition wall portion 64. It has been. Thereby, at the location where the thin wall portion 70 is provided, the equilibrium chamber side partition wall portion 64 is easily deformed when the movable rubber plate portion 56 is deformed, and the cavitation noise is reduced or reduced by short-circuiting the orifice passage 84. Can advantageously be avoided.

  Further, in the present embodiment, a recess 72 is formed in the central portion of the thin wall portion 70, and the rigidity of the equilibrium chamber side partition wall portion 64 is smaller at the position where the recess 72 is formed. Therefore, the deformation of the equilibrium chamber side partition wall 64 is realized more advantageously, and the elimination of cavitation by short-circuiting the orifice passage 84 to the equilibrium chamber 82 can be effectively realized.

  Moreover, in the present embodiment, the outer peripheral edge of the movable rubber plate portion 56 is formed so as to extend from the intermediate portion in the axial direction of the equilibrium chamber side partition wall portion 64, and on the extension line to the outer peripheral side of the taper portion 60. A recess 72 is positioned. Therefore, the equilibrium chamber side partition wall portion 64 is advantageously deformed based on the distortion caused by the deformation of the movable rubber plate portion 56 transmitted to the equilibrium chamber side partition wall portion 64.

  Further, the equilibrium chamber-side partition wall 64 is pressed against the fixture 28 from above in the axial direction, so that the orifice passage 84 is partitioned from the equilibrium chamber 82. Therefore, when a positive pressure fluctuation is applied to the pressure receiving chamber 80, the orifice passage 84 is maintained in a state of being fluid-tightly partitioned from the equilibrium chamber 82. Therefore, when a positive pressure fluctuation occurs in the pressure receiving chamber 80, the fluid pressure in the pressure receiving chamber 80 is prevented from escaping to the equilibrium chamber 82 due to a short circuit of the orifice passage 84, and fluid flow through the orifice passage 84 is prevented. Can be produced advantageously. Thereby, the outstanding vibration-proof effect can be acquired advantageously.

  Further, when the movable rubber plate portion 56 returns to the initial position (initial shape), the equilibrium chamber side partition wall portion 64 is also restored to the initial shape, and the orifice passage 84 is fluid-tight from the equilibrium chamber 82 by the equilibrium chamber side partition wall portion 64. It is supposed to be separated. Therefore, it is possible to achieve both an effective anti-vibration effect that is exhibited against normal input vibration and a cavitation reduction effect that is exhibited when a heavy load is input.

  It should be noted that the generation level of abnormal noise caused by cavitation, which is 100 N or more in terms of dynamic spring, in the fluid-filled vibration isolator having a conventional structure in which measures for cavitation are not taken by measuring the generation level of abnormal noise is a structure according to the present invention. It was confirmed that by adopting a fluid-filled vibration isolator having an elastic rubber wall, it was possible to reduce the dynamic spring equivalent value to 12 to 20N. In addition, a fluid-filled vibration isolator equipped with a relief valve that is known to be extremely effective as a countermeasure against cavitation (by providing a valve that opens and closes according to the negative pressure level in the pressure receiving chamber, In the fluid-filled vibration isolator that reduces or avoids cavitation noise by reducing the pressure, there is experimental data that the noise generation level is about 12N in terms of dynamic spring, and measures against cavitation It is clear that the present invention is effective. In addition, in the fluid filled type vibration isolator constructed according to the present invention, there is almost no effect on the vibration isolating performance of the main body such as the damping effect against the low frequency vibration exhibited through the orifice passage, and the noise reduction. It was confirmed by experiments that it was possible to achieve both maintenance of excellent vibration isolation effect.

  As mentioned above, although one Embodiment of this invention was described, this is an illustration to the last, Comprising: This invention is not interpreted restrictively at all by the specific description in this Embodiment.

  For example, in the embodiment, the thin wall portions 70 are provided at a plurality of locations on the circumference of the equilibrium chamber side partition wall portion 64, but the specific shape and the like of the thin wall portion 70 is as described in the embodiment. It is not limited. Specifically, for example, the thin wall portion 70 may not necessarily be provided so as to be thin over the entire axial length of the equilibrium chamber side partition wall portion 64. A thin wall portion may be provided by forming a recess in the portion and partially thinning the equilibrium chamber side partition wall portion 64. In addition, the thin wall portion 70 in the above embodiment is formed by providing a notch-shaped recess that opens on the outer peripheral surface of the equilibrium chamber side partition wall portion 64 and extends over the entire length in the axial direction. A thin wall portion can also be realized by providing a notch or a recess so as to open on the inner peripheral surface of the chamber-side partition wall portion 64.

  In the above-described embodiment, an example in which the thin wall portions 70 are provided at three positions that are equally spaced in the circumferential direction has been described. However, the number of thin wall portions 70 and the positions where they are formed are appropriately set. Thus, the present invention is not construed as being limited by the embodiment.

  Further, the thin wall portion 70 is not essential, and the equilibrium chamber side partition wall portion 64 is formed with a constant thickness over substantially the entire circumference, so that the strain due to the displacement of the movable rubber plate portion 56 is transmitted, thereby achieving equilibrium. The entire chamber-side partition wall 64 may be deformed so that the orifice passage 84 is short-circuited to the equilibrium chamber 82.

  In the embodiment, the equilibrium chamber side partition wall 64 is formed to extend in the axial direction toward the equilibrium chamber 82 side. However, the equilibrium chamber side partition is not necessarily extended in the axial direction. It is not necessary to form, for example, you may make it the taper shape etc. which were formed so that it might incline and extend toward the equilibrium chamber 82 side.

  In the embodiment, the depression 72 is formed in the central portion of the thin wall portion 70 in the axial direction. However, the depression 72 is formed in an intermediate portion of the thin wall portion 70 in the height direction (projection direction). It does not necessarily have to be formed in the central portion.

  Further, the shape of the recess is not limited to the shape of the recess 72 specifically shown in the embodiment. That is, the recess may be, for example, a rectangular recess extending in the radial direction with a substantially constant rectangular cross section, a frustum-like shape or a conical recess that gradually increases in diameter toward the opening side, and the like. In addition, one recess may not necessarily be formed for each thin portion. For example, a plurality of recesses may be provided so as to be separated from each other in the protruding direction of the elastic rubber wall.

  Further, it is desirable that the recess is formed so as to open to the outer peripheral surface of the thin portion like the recess 72 shown in the above-described embodiment, thereby advantageously causing elastic deformation of the elastic rubber wall. I can do it. However, the recess only needs to be formed so as to overlap with the projection in the thickness direction (in the radial direction in the embodiment) of the elastic rubber wall with respect to the thin wall portion. For example, the recess is opened on the inner peripheral surface of the thin wall portion. It may be formed as such, or a plurality may be provided so as to open on both the outer peripheral surface and the inner peripheral surface.

  Further, in the above embodiment, the vertical plate portion 48 formed integrally with the support fitting 40 and fixed to the equilibrium chamber side partition wall portion 64 is provided, and in the vicinity of the pressure receiving chamber 80 side opening portion of the orifice passage 84, The vertical plate portion 48 is fixed to the equilibrium chamber side partition wall portion 64. However, there is no need for such a vertical plate portion 48, and by adjusting the fastening margin of the equilibrium chamber side partition wall 64 to the fixing bracket 28, the short circuit of the orifice passage 84 during normal vibration input is prevented. It is also possible to make it.

  Further, as shown in the embodiment, it is desirable that the movable rubber plate portion 56 is formed so as to extend from the intermediate portion in the axial direction of the equilibrium chamber side partition wall portion 64 to the inner peripheral side. However, when an excessive negative pressure is generated in the pressure receiving chamber 80 and the movable rubber plate portion 56 is sucked and displaced, the equilibrium chamber side partition portion 64 may be deformed. For example, the movable rubber plate The portion 56 may be formed so as to extend from the lower end in the axial direction of the equilibrium chamber side partition wall portion 64 to the inner peripheral side. The outer peripheral portion of the movable rubber plate portion 56 is balanced at the portion where the recess 72 is formed or the portion located on the front end side in the protruding direction of the equilibrium chamber side partition wall portion 64 (lower side in the axial direction in the embodiment). It is desirable to be connected to the room side partition wall 64.

  In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various changes, modifications, improvements and the like are added based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.

It is a longitudinal cross-sectional view which shows the engine mount for motor vehicles as one Embodiment of this invention, Comprising: The II sectional view taken on the line in FIG. The II-II sectional view taken on the line in FIG. 3 of the engine mount shown by FIG. The top view which shows the partition member which comprises the engine mount shown by FIG. The side view of the partition member shown by FIG. The bottom view of the partition member shown by FIG. The top view which shows the support metal fitting which comprises the partition member shown by FIG. The side view of the support metal fitting shown by FIG.

Explanation of symbols

10: Automotive engine mount, 12: First mounting bracket, 14: Second mounting bracket, 16: Rubber elastic body, 26: Diaphragm, 28: Fixing bracket, 30: Stepped portion, 34: Covered rubber layer, 38: partition member, 40: support fitting, 42: partition member body, 48: vertical plate portion, 56: movable rubber plate portion, 58: orifice forming portion, 60: taper portion, 64: equilibrium chamber side partition portion, 70: Thin wall part, 72: depression, 80: pressure receiving chamber, 82: equilibrium chamber, 84: orifice passage

Claims (7)

A first attachment member attached to one member to be vibration-proof connected and a second attachment member attached to the other member to be vibration-proof connected to each other by a main rubber elastic body, and the second On both sides of the partition member supported by the mounting member, a pressure receiving chamber in which a part of the wall is made of the main rubber elastic body, and an equilibrium chamber in which a part of the wall is made of a flexible film In the fluid-filled vibration isolator provided with an incompressible fluid in the pressure receiving chamber and the equilibrium chamber, and provided with an orifice passage communicating the pressure receiving chamber and the equilibrium chamber with each other,
One of the partition members is configured by using an annular support bracket to close the central hole of the support bracket with a movable rubber film and supporting the outer peripheral edge of the support bracket with the second mounting member. The orifice passage is formed integrally with the movable rubber film at the outer peripheral edge of the movable rubber film so as to protrude toward the equilibrium chamber and extend in the circumferential direction. When the movable rubber film is elastically deformed toward the pressure receiving chamber, the strain of the movable rubber film is transmitted to the elastic rubber wall, so that the orifice passage is short-circuited to the equilibrium chamber. A fluid-filled vibration isolator characterized by being made capable of being used.   2. The fluid-filled type according to claim 1, wherein a reinforcing flange wall integrally formed with the support fitting is fixed to the elastic rubber wall at a portion where an opening portion of the orifice passage toward the pressure receiving chamber is located. Anti-vibration device.   The fluid-filled vibration isolator according to claim 1 or 2, wherein the movable rubber film is integrally formed with the elastic rubber wall so as to extend from an intermediate portion in the height direction of the elastic rubber wall.   4. The fluid filled type vibration damping device according to claim 1, wherein an outer peripheral portion of the movable rubber film is a tapered portion that gradually inclines toward the balance chamber side toward the outer peripheral side. 5.   The fluid-filled vibration isolator according to any one of claims 1 to 4, wherein a thin wall portion is provided on at least a part of the circumference of the elastic rubber wall.   The fluid filled type vibration damping device according to claim 5, wherein a recess is formed in an intermediate portion in the height direction of the thin wall portion in the elastic rubber wall. Using the fluid filled type vibration damping device according to any one of claims 1 to 6, the first attachment member is attached to one of a power unit and a vehicle body, and the second attachment member is attached to the power unit. In an engine mount that is interposed between the power unit and the vehicle body and attached to the other side of the vehicle body to support the vibration of the power unit with respect to the vehicle body.
The tuning frequency of the orifice passage is set to a low frequency range corresponding to an engine shake input in a normal running state, and the elastic rubber wall is used for the equilibrium chamber and the orifice when the engine shake is input in a normal running state. The elastic rubber wall is elastically deformed when a shocking heavy load is input, and the orifice passage is short-circuited to the equilibrium chamber at the position where the elastic rubber wall is formed. An engine mount characterized by that.

Images