JP2011137477A - Liquid filled vibration damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of cavitation when the inside of a main liquid chamber is brought into a negative pressure condition and to suppress an increase in a dynamic spring constant in a liquid-sealed vibration control device with a cut formed in a movable plate. <P>SOLUTION: An engine mount 1 includes a connecting fitting 3, a support fitting 5, a rubber elastic body 7 for connecting them, an orifice board 9 partitioning a liquid chamber 11 varied in its volume along with the deformation of the rubber elastic body 7 into a pressure receiving chamber 21 and an equilibrium chamber 31, an orifice passage 19 for making the pressure receiving chamber 21 and the equilibrium chamber 31 communicated, and the movable plate 41 housed in a housing chamber 29 of the orifice board 9. In the central part of the housing chamber 29, spaces 29b, 29c for allowing the elastic deformation of the movable plate 41 exist. The movable plate 41 includes a central part 51 corresponding to the spaces 29b, 29c, and a peripheral edge part 61 around it, and the thickness of the central part 51 is thinner than that of the peripheral edge part 61. In the central part 51, a cut slit 71 passing through in a shaft line Z direction is formed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid-filled vibration isolator, and more particularly to a liquid-filled vibration isolator in which a cut is formed in a movable plate for absorbing fluid pressure fluctuations in a main liquid chamber.

  Conventionally, as an anti-vibration device such as an engine mount that effectively absorbs and attenuates engine vibration in a predetermined frequency range, a rubber elastic body is provided between the support bracket on the engine side and the support bracket on the vehicle body. And a liquid chamber formed between the connection fitting and the support fitting so that the volume changes with deformation of the rubber elastic body, and a partition that partitions the inside of the liquid chamber into a main liquid chamber and a sub liquid chamber There is known a liquid-filled vibration isolator including a member, an orifice passage communicating the main liquid chamber and the sub liquid chamber, and a movable plate housed in a housing chamber formed inside the partition member. .

  In such a liquid-filled vibration isolator, during normal vibration input, vibration damping is performed by the liquid column resonance action by the liquid flow in the orifice passage and the vibration damping effect of the rubber elastic body. In such a case, the vibration isolator itself may become an abnormal sound source.

  Such abnormal noise is generated by cavitation. More specifically, when a large vibration is input to the vibration isolator, the main liquid chamber becomes excessively negative pressure and the sealed liquid is saturated. A large number of bubbles are generated by lowering the vapor pressure, and the bubbles generated in this way are generated by an impact sound when the bubbles disappear.

  In order to prevent the main liquid chamber from being in such an excessive negative pressure state, for example, Patent Document 1 discloses that the movable plate is different from the movable plate arranged to partition the pressure receiving chamber and the equilibrium chamber. An opening that allows fluid flow from the equilibrium chamber to the pressure receiving chamber by cooperating with the central communication hole formed in the lid plate metal fitting in a state in which the displacement toward the pressure receiving chamber is constrained by the lid plate metal fitting (a tongue-like shape) And a fluid flow from the pressure receiving chamber to the equilibrium chamber through the opening in a state where the displacement of the movable plate to the equilibrium chamber side is restrained by the bottom wall with respect to the bottom wall. A liquid-filled vibration isolator provided with an inner contact portion for blocking is disclosed. According to this liquid-filled type vibration isolator, it is possible to quickly eliminate the excessive negative pressure generated in the pressure receiving chamber, and also to ensure the flow amount of the fluid flowing through the orifice passage so that the fluid flow action It is said that it is possible to exhibit an anti-vibration effect based on the above.

JP 2006-112607 A

  However, in the thing of the said patent document 1, since the press-release movable piece which comprises opening is formed thick similarly to the other site | part of a movable plate, a press-release movable piece becomes difficult to deform | transform, and opening is open. May be difficult to open.

  Moreover, in the thing of patent document 1, since a deformation | transformation to the equilibrium chamber side of a pressure release movable piece is prevented by an inner side contact part, there exists a possibility that the pressure of a pressure receiving chamber may rise and a dynamic spring constant may become high. .

  The present invention has been made in view of such a point, and the object of the present invention is a liquid-filled vibration isolator in which a cut is formed in a movable plate for absorbing fluid pressure fluctuation in the main fluid chamber. An object of the present invention is to provide a technique for reliably opening a notch when the main liquid chamber is in a negative pressure state, thereby suppressing the occurrence of cavitation and suppressing an increase in the dynamic spring constant.

  In order to achieve the above object, in the present invention, a space for allowing elastic deformation of the movable plate accommodated in the accommodating chamber formed inside the partition member toward the main liquid chamber side and the sub liquid chamber side. By forming the storage chamber and the movable plate so as to exist, the cut formed in the movable plate is easily opened when the main liquid chamber is in a negative pressure state.

  The first invention is a connecting metal fitting connected to the supported body side, a support metal fitting connected to the support body side, connecting both the metal fittings, and by axial deformation connecting both the metal fittings at least in the axial direction by elastic deformation. A relatively elastic rubber body, a liquid chamber formed between the connecting metal fitting and the support metal fitting so that the volume changes with deformation of the rubber elastic body, and a main liquid chamber inside the liquid chamber. A partition member that is partitioned into a secondary liquid chamber, an orifice passage that communicates the main liquid chamber and the secondary liquid chamber, and a movable member that is movably accommodated in the axial direction in a storage chamber formed inside the partition member. A liquid-filled vibration isolator having a plate, wherein the partition member is formed with a communication hole for communicating the storage chamber with each of the main liquid chamber and the sub liquid chamber. The central part of the movable plate is elastic to the main liquid chamber side and sub liquid chamber side of the movable plate. A space for allowing a shape exists, and the movable plate has a central portion corresponding to the space formed in a substantially disc shape and a peripheral portion around the central portion formed in a substantially annular shape, and The axial thickness of the central portion is thinner than the axial thickness of the peripheral portion, and a slit slit penetrating in the axial direction is formed in the central portion of the movable plate. It is a feature.

  According to the first invention, when a large vibration is input to the vibration isolator and the main liquid chamber is in a negative pressure state, the movable plate accommodated in the housing chamber so as to be movable in the axial direction is accommodated in the partition member. It is pressed against the surface of the main liquid chamber side that divides the chamber.

  Here, in the storage chamber, for example, the main liquid chamber side (sub liquid chamber side) surface of the partition member that divides the storage chamber is recessed in the main liquid chamber side (sub liquid chamber side), or the movable plate By allowing the main liquid chamber side (sub liquid chamber side) surface to be recessed into the sub liquid chamber side (main liquid chamber side), elastic deformation of the movable plate to the main liquid chamber side and sub liquid chamber side is permitted. There exists a space for Thus, even when the peripheral portion is pressed against the main liquid chamber side surface of the partition member that divides the storage chamber, the central portion of the movable plate is not restricted to the main liquid chamber side. Since it deform | transforms so that it may swell, the cut slit formed so that it may penetrate in an axial direction becomes easy to open.

  Since the slits are easily opened in this manner, the liquid can easily flow from the sub liquid chamber side to the main liquid chamber side, and the main liquid chamber side is quickly decompressed, thereby suppressing the occurrence of cavitation.

  Further, since the axial thickness of the central portion of the movable plate is thinner than the axial thickness of the peripheral portion, the central portion is more easily deformed more reliably. Furthermore, since the axial thickness of the central portion of the movable plate is formed thin, even if the partition member has a flat surface defining the storage chamber, the central portion of the peripheral portion By adjusting the position in the axial direction, a space for allowing the elastic deformation of the movable plate in the axial direction can be easily secured.

  In addition, since there is a space for allowing elastic deformation of the movable plate toward the sub liquid chamber, the main liquid chamber is in a pressed state and partitions the storage chamber. Even when the peripheral portion is pressed against this surface, the central portion of the movable plate is deformed to the sub liquid chamber side without being restricted from being deformed. By using such elastic deformation of the movable plate, the increase in the hydraulic pressure in the main liquid chamber is absorbed, so that the dynamic spring constant is larger than when there is no space on the sub liquid chamber side of the movable plate. Can be suppressed (membrane effect).

  According to a second aspect of the present invention, in the first aspect of the invention, the cut slit is formed so that both ends thereof are positioned at a boundary between a central portion and a peripheral portion of the movable plate. .

  According to the second aspect of the invention, since both ends of the slits are formed so as to be located at the boundary between the central portion and the peripheral portion of the movable plate, the thicknesses in the axial direction are different from each other. Even if the slits formed in the slits proceed in the radial direction, the peripheral portion having a thick axial direction functions as a stopper. Thereby, it can suppress that the notch | incision of a notch | slit slit advances to a radial direction.

  According to a third aspect of the present invention, in the second aspect of the present invention, in order to prevent the incision of the incision slit from proceeding along the outer periphery of the central portion on the inner peripheral surface of the peripheral portion of the movable plate, In the portion corresponding to the end of the slit, a protruding portion protruding radially inward is formed.

  According to the third aspect of the invention, the diameter formed in the portion corresponding to the end of the cut slit even if the cut of the cut slit whose progress in the radial direction is restricted proceeds along the inner peripheral surface of the peripheral portion. A protruding portion protruding inward in the direction functions as a stopper. Thereby, it can suppress that the notch | incision of an incision slit advances in the circumferential direction of a thin center part in the boundary of a center part and a peripheral part.

  According to a fourth invention, in any one of the first to third inventions, when the movable plate is deformed at a central portion of the movable plate where the cut slit is not formed, the partition member is provided. In this case, a protruding portion that protrudes toward the main liquid chamber side and / or the auxiliary liquid chamber side is formed so as to be in contact with a surface that is orthogonal to the axial direction and that partitions the space.

  According to the fourth aspect of the invention, for example, when the main liquid chamber is in a negative pressure state, the movable plate is deformed so as to swell toward the main liquid chamber, thereby projecting toward the main liquid chamber at the center of the movable plate. The protruding portion formed so as to abut the surface of the partition member perpendicular to the axial direction and partitioning the space. As a result, the protrusion that is in contact with the surface of the partition member serves as a fulcrum, and the movable plate is more easily deformed.

  According to a fifth invention, in any one of the first to fourth inventions, when the movable plate is deformed on a surface of the partition member perpendicular to the axial direction and defining the space, A protruding portion that protrudes toward the main liquid chamber side and / or the sub liquid chamber side is formed so as to abut on the central portion of the movable plate.

  According to the fifth invention, for example, when the main liquid chamber is in a negative pressure state, the movable plate is deformed so as to swell toward the main liquid chamber, thereby forming the partition member so as to protrude toward the sub liquid chamber. The projecting portion thus made contacts the central portion of the movable plate. As a result, the projecting portion in contact with the central portion of the movable plate serves as a fulcrum, and the movable plate is more easily deformed.

  According to a sixth invention, in any one of the first to fifth inventions, the space defines a surface of the partition member perpendicular to the axial direction and defining the storage chamber on the main liquid chamber side and / or Alternatively, a slope portion that is formed by being dented toward the sub liquid chamber side, and that slopes radially outward toward the movable plate side on the surface of the partition member that is parallel to the axial direction and that partitions the space. Is partially formed.

  According to the sixth invention, even if the space formed by denting the surface of the partition member is closed by the deformable movable plate, the slope portion partially formed on the surface partitioning the space Since the space and the storage chamber communicate with each other, the ease of liquid flow can be ensured.

  According to the liquid-filled vibration isolator according to the present invention, the accommodating chamber has a space for allowing elastic deformation of the movable plate toward the main liquid chamber side and the sub liquid chamber side. Even when the peripheral portion of the plate is pressed against the surface of the partition member on the main liquid chamber side, the deformation of the central portion of the movable plate is not restricted and deforms so as to swell toward the main liquid chamber side. As a result, the slit formed in the central portion is opened, so that the liquid can easily flow from the sub liquid chamber side to the main liquid chamber side, and the main liquid chamber side is quickly decompressed, thereby suppressing the occurrence of cavitation.

  Furthermore, since the axial thickness of the central portion of the movable plate is thinner than the axial thickness of the peripheral portion, the central portion is more easily deformed more reliably.

  Further, even when the main liquid chamber is pressed and the peripheral portion of the movable plate is pressed against the surface of the partition member on the sub liquid chamber side, the deformation of the central portion of the movable plate is not restricted. Due to the deformation to the liquid chamber side, the increase in the hydraulic pressure in the main liquid chamber is absorbed, and the increase in the dynamic spring constant can be suppressed.

1 shows an automotive engine mount which is an embodiment of a liquid-filled vibration isolator according to the present invention. FIG. 4A is a longitudinal sectional view showing the orifice plate and the movable plate, and FIG. 4B is a bottom view showing the movable plate. It is a perspective view which shows the upper side main-body part of an orifice board. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2. It is a longitudinal cross-sectional view which shows the deformation | transformation state of a movable plate typically. It is a longitudinal cross-sectional view which shows an orifice board and a movable plate. It is a longitudinal cross-sectional view which shows an orifice board and a movable plate. It is a longitudinal cross-sectional view which shows an orifice board and a movable plate. It is a top view which shows the shape of an incision slit.

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

-Overall structure of mount-
FIG. 1 shows an automobile engine mount which is an embodiment of a liquid-filled vibration isolator according to the present invention. The engine mount 1 includes an automobile engine and a transmission (not shown), which are collectively referred to as a power plant. Between the power plant and the vehicle body to support the static load of the power plant and to absorb or attenuate the vibration from the power plant to suppress the transmission of vibration to the vehicle body. ing. In the following description, the upper side in FIG. 1 is the upper side in the axis Z direction (hereinafter referred to as the upper side), and the lower side in FIG. 1 is the lower side in the axis Z direction (hereinafter referred to as the lower side).

  The engine mount 1 includes a substantially columnar coupling fitting 3 attached to a power plant as a supported body via a bracket (not shown), a cylindrical supporting fitting 5 attached to a vehicle body frame as a support, A rubber elastic body 7 that connects the metal fittings 3 and 5 and relatively displaces both the metal fittings 3 and 5 in the direction of the axis Z connecting the metal fittings 3 and 5 by elastic deformation is provided on the lower outer periphery of the support metal fitting 5. The pair of leg portions 35, 35 that are welded to each other are fixed to the vehicle body frame. The support metal 5 also functions as a case of the engine mount 1 together with a stopper metal 45 described later.

  The connecting fitting 3 has a flange portion 23 at an intermediate portion in the direction of the axis Z, a taper portion 33 narrowed downward is provided below the flange portion 23, and a shaft portion 13 is provided above the flange portion 23. Are formed. A bracket on the power plant side is attached to the upper end surface of the shaft portion 13, and a bolt (not shown) is screwed into the bolt hole 13a. The flange portion 23 has an annular shape centered on the axis Z, and annular stopper rubbers 37 and 47 are provided on the upper surface and the outer peripheral surface, respectively.

  Further, a passage 33 a is formed in the connection fitting 3 so as to extend downward from the lower end of the bolt hole 13 a and open to the tip of the tapered portion 33. The passage 33 a is smaller in diameter than the bolt hole 13 a and communicates with the bolt hole 13 a through a taper portion that extends upward, and serves as a path for supplying liquid to the liquid chamber 11. A sealing material 33b such as a steel ball is driven into the upper end of the passage 33a to seal the liquid chamber 11.

  The rubber elastic body 7 is vulcanized and bonded at the upper portion thereof to cover the lower taper portion 33 of the connection fitting 3, and the thick umbrella-like portion 17 extending radially downward from there is formed, A cylindrical portion 27 extending downward continuously from the lower end of the umbrella-shaped portion 17 is provided, and the cylindrical portion 27 is fixed to the inner periphery of the support fitting 5. The support fitting 5 has a double structure composed of an inner cylinder 15 and an outer cylinder 25, and the inner cylinder 15 is embedded and integrated in a cylindrical portion 27 of the rubber elastic body 7. The outer peripheral surface is fixedly bonded to the inner peripheral surface of the outer cylinder 25.

  Further, the cylindrical portion 27 of the rubber elastic body 7 has an inner diameter enlarged on the lower side to form an annular step portion, and an orifice disc (partition member) 9 is inserted from below as the step portion. In addition, a rubber diaphragm 59 is disposed so as to cover the orifice plate 9 from below. The diaphragm 59 has a bowl shape that opens upward as a whole. A thick portion 59a is formed around the opening edge, and a reinforcing member 59b is embedded in the thick portion 59a. The thick part 59a thus reinforced is superimposed on the lower surface of the orifice board 9 in a liquid-tight manner and is caulked from below by a flange 15b formed inwardly at the lower end of the inner cylinder 15 of the support fitting 5. The volume of the diaphragm 59 is greatly changed when the upwardly projecting annular portion and the downwardly projecting annular portion are inverted up and down.

  The lower end of the cylindrical portion 27 is closed by the diaphragm 59 whose volume changes as described above, and liquid is sealed inside the rubber elastic body 7 (between the connection fitting 3 and the support fitting 5), and the rubber elastic body 7 A liquid chamber 11 whose volume changes with the deformation is formed. The liquid chamber 11 is divided into upper and lower parts by an orifice plate 9, the upper side thereof is a pressure receiving chamber (main liquid chamber) 21, and the lower side, that is, the portion partitioned by the orifice plate 9 and the diaphragm 59 is an equilibrium chamber. (Sub-liquid chamber) 31. When the vibration from the power plant is input and the rubber elastic body 7 is deformed, the volume of the pressure receiving chamber 21 mainly changes, and the liquid receives the pressure received through the orifice passage 19 that connects the pressure receiving chamber 21 and the equilibrium chamber 31. It flows between the chamber 21 and the equilibrium chamber 31. As the liquid flows in and out, the diaphragm 59 is deformed as described above, and the volume of the equilibrium chamber 31 changes (volume compensation).

  The orifice board 9 is formed by combining a resin upper main body 39 and a lower main body 49 to form a relatively thick disk as a whole, and the storage chamber 29 formed therein is made of rubber. The movable plate 41 is accommodated so as to be movable in the axis Z direction. When an engine vibration having a relatively high frequency and a small amplitude is input, the movable plate 41 absorbs the fluid pressure fluctuation in the pressure receiving chamber 21 by vibrating in synchronization with the vibration.

  As shown in FIGS. 2A and 3, the upper main body 39 includes a disc-shaped top wall 39a and the outer peripheral end of the bottom surface of the top wall 39a on the side of the equilibrium chamber 31 in the axis Z direction (lower A circular outer side wall 39b extending to the side) and a circle concentrically with the outer side wall 39b and projecting downward from the lower surface of the top wall 39a on the inner side in the radial direction than the outer side wall 39b. And an annular inner wall 39c. The inner side wall 39c is thicker in the radial direction than the outer side wall 39b. In addition, the central top wall portion 39d inside the inner flange wall portion 39c of the top wall portion 39a has a smaller thickness in the axis Z direction than other portions of the top wall portion 39a.

  On the other hand, the lower main body portion 49 includes a disc-shaped bottom wall portion 49a and an annular outer side wall portion extending from the outer peripheral end portion on the upper surface of the bottom wall portion 49a to the pressure receiving chamber 21 side (upper side) in the axis Z direction. 49b and an annular inner side wall part 49c concentric with the outer side wall part 49b and extending radially inward of the outer side wall part 49b and upward from the upper surface of the bottom wall part 49a.

  Then, when the upper main body portion 39 and the lower main body portion 49 are concentrically overlapped, a storage chamber 29 for storing the movable plate 41 between the upper main body portion 39 and the lower main body portion 49, An orifice passage 19 is formed so as to surround the storage chamber 29.

  The storage chamber 29 is defined by the upper surface of the bottom wall portion 49a, the inner peripheral surface of the inner side wall portion 49c, the lower end surface and inner peripheral surface of the inner side wall portion 39c, and the lower surface of the central top wall portion 39d. The space is shaped like two large and small disks concentrically stacked in the axis Z direction. As shown in FIG. 3, there are eight through holes (communication holes) 39e in the top wall portion 39a (excluding the central top wall portion 39d) and the inner side wall portion 39c so that the storage chamber 29 communicates with the pressure receiving chamber 21. , 39e,... And four through holes (communication holes) 39f, 39f,. Similarly, twelve through holes (communication holes) 49d, 49d,... Are formed in the bottom wall portion 49a on the inner side of the inner flange wall portion 49c so that the storage chamber 29 communicates with the equilibrium chamber 31.

  The orifice passage 19 is a space defined by the upper surface of the bottom wall portion 49a, the inner peripheral surfaces of the outer ridge wall portions 39b and 49b, the outer peripheral surface of the inner ridge wall portions 39c and 49c, and the lower surface of the top wall portion 39a. One end of the balance chamber 31 faces the pressure receiving chamber 21 through an opening (not shown) on the upper surface of the upper main body 39 and the other end opens from the opening (not shown) opened on the lower surface of the lower main body 49. It faces. The orifice passage 19 is tuned to a vibration having a relatively low frequency and a large amplitude.

  On the other hand, a stopper fitting 45 having a cylindrical shape substantially the same diameter as the outer cylinder 25 is attached to the upper end of the support fitting 5 so as to surround the upper portion of the engine mount 1 such as the umbrella-like portion 17 of the rubber elastic body 7. It has been. A flange 45b projecting outward is formed at the lower end of the stopper fitting 45, and this flange 45b is placed on the upper end of the cylindrical portion 27 of the rubber elastic body 7 and formed outward at the upper end of the inner cylinder 15 inside thereof. The flange 15a is caulked by a U-shaped portion 25a formed at the upper end of the outer cylinder 25.

  The stopper fitting 45 regulates the relative displacement of the connecting fitting 3 in the front-rear direction by contacting the stopper rubber 47 of the flange 23. A flange 45a is formed at the upper end of the stopper fitting 45 so as to surround the shaft portion 13 of the connecting fitting 3 and extends toward the inner peripheral side. The lower surface of the flange 45a is connected to the stopper rubber 37 on the upper surface of the flange portion 23. By abutting, the upward displacement of the connection fitting 3 is regulated.

  FIG. 1 shows a state where a static load of the power plant is not applied to the engine mount 1, and the gap between the stopper rubber 37 on the upper surface of the flange 23 and the flange 45a on the upper end of the stopper fitting 45 is small. In the 1G state where the engine mount 1 is attached to an automobile to support the power plant and a static load is applied thereto, the rubber elastic body 7 is bent and the connecting fitting 3 is displaced downward, so that the gap becomes large.

-Structure of movable plate and storage chamber-
As described above, the storage chamber 29 is a space formed by concentrating two large and small disks concentrically in the direction of the axis Z, and the movable plate 41 is stored in a large disk-shaped space 29a on the equilibrium chamber 31 side. Has been. As a result, a space 29b for allowing elastic deformation of the movable plate 41 toward the pressure receiving chamber 21 is present above the movable plate 41 (on the pressure receiving chamber 21 side) in the central portion of the storage chamber 29. Become. In other words, the space 29b is formed by denting the lower surface of the upper body portion 39 that partitions the storage chamber 29 upward (the pressure receiving chamber 21 side).

  As shown in FIG. 2A, the movable plate 41 includes a central portion 51 formed in a substantially disc shape so as to face the space 29b, and a peripheral edge formed in a substantially annular shape around the central portion 51. Part 61. The movable plate 41 is integrally formed so that the upper surface of the central portion 51 and the upper surface of the peripheral portion 61 are flush with each other, and the thickness of the central portion 51 in the axis Z direction is the same as that of the peripheral portion 61 in the axis Z direction. It is thinner than the thickness. For this reason, although the upper surface of the bottom wall part 49a which divides the storage chamber 29 is formed flat, the central portion of the storage chamber 29 is located below the movable plate 41 (on the equilibrium chamber 31 side). A space 29c for allowing elastic deformation of the movable plate 41 toward the equilibrium chamber 31 is present. Specifically, the space 29 c is partitioned by the upper surface of the bottom wall portion 49 a, the inner peripheral surface of the peripheral edge portion 61, and the lower surface of the central portion 51.

  The movable plate 41 is formed with cut slits 71 penetrating in the direction of the axis Z so that both ends thereof are located at the boundary between the central portion 51 and the peripheral portion 61 of the movable plate 41 at a portion corresponding to the space 29b. ing. Specifically, as shown in FIG. 2 (b), two slits 71 and 71 are formed along the outer periphery of the central portion 51. Thus, since both ends 71a and 71a of the slit slit 71 are formed so as to be positioned at the boundary between the central portion 51 and the peripheral portion 61 of the movable plate 41, the thicknesses in the axis Z direction are different. When the incision of the incision slit 71 formed in the central portion 51 is going to proceed in the radial direction, the thick peripheral portion 61 functions as a stopper. Thereby, it can suppress that the notch | incision of the incision slit 71 advances to radial direction.

  Further, on the inner peripheral surface of the peripheral portion 61, in order to prevent the cut of the cut slit 71 from proceeding along the outer periphery of the central portion 51, the portion corresponding to the end 71a of the cut slit 71 is radially inward. Protruding portions 61 a, 61 a projecting from the lower end of the peripheral portion 61 to the lower surface of the central portion 51 are formed. Note that the upper ends of the protruding portions 61 a and 61 a are integrally connected to the lower surface of the central portion 51. As described above, the protrusions 61 a and 61 a are formed on the inner peripheral surface of the peripheral portion 61, so that the cut of the cutting slit 71 whose progress in the radial direction is restricted is along the inner peripheral surface of the peripheral portion 61. Even if it is going to proceed, the protrusion 61a functions as a stopper. Thereby, it is possible to suppress the cutting of the cutting slit 71 from proceeding along the outer periphery of the thin central portion 51 at the boundary between the central portion 51 and the peripheral portion 61.

  In addition, at the central portion of the upper surface of the central portion 51 of the movable plate 41, when the central portion 51 is deformed, the lower surface of the central top wall portion 39d (orthogonal disc that is perpendicular to the axis Z direction and defines the space 29b). 9 is formed so as to protrude toward the pressure receiving chamber 21 side. The upper protrusion 51a is less likely to generate abnormal noise when the tip of the upper protrusion 51a contacts the lower surface of the central top wall 39d when the central portion 51 is deformed to the pressure receiving chamber 21 side. Further, it is formed in a tapered shape.

  On the other hand, on the lower surface of the central portion 51 of the movable plate 41, when the central portion 51 is deformed at a position corresponding to the upper protruding portion 51a, the balance chamber 31 side is in contact with the upper surface of the bottom wall portion 49a. A lower protrusion 51b is formed to protrude from the bottom. Note that the lower protrusion 51b also has a tapered shape so that the noise generated by the tip of the lower protrusion 51b coming into contact with the upper surface of the bottom wall 49a is reduced, like the upper protrusion 51a. Is formed.

  Further, on the inner peripheral surface (the surface of the orifice plate 9 that is parallel to the axis Z direction and defines the space 29b) of the inner side wall portion 39c of the upper body portion 39, the radial direction is directed downward (movable plate 41 side). Four slope portions 39g, 39g,... Inclined outward are formed. In this way, even if the space 29b is temporarily blocked by the deformed central portion 51 of the movable plate 41 by forming the slope portions 39g, 39g, ... inclined radially outward, the slope portion 39g Since the space 29b and the storage chamber 29 communicate with each other, it is possible to ensure the ease of liquid flow.

  When the slope portions 39g, 39g,... Are formed, the liquid flow has directionality, so that the positional relationship between the slope portions 39g, 39g,. There is a need. For this reason, in the present embodiment, as shown in FIG. 4, four concave portions 61 b, 61 b,... Recessed radially inward are formed on the outer peripheral surface of the peripheral portion 61 of the movable plate 41. Four convex portions 49e, 49e,... Projecting radially inward are formed on the inner peripheral surface of the inner side wall portion 49c of the lower main body portion 49 so as to correspond to the concave portions 61b, 61b,. When the movable plate 41 is fitted into the lower main body 49, the four convex portions 49e, 49e,... Are engaged with the four concave portions 61b, 61b,. Rotation in the chamber 29 is suppressed, and the positional relationship between the slope portions 39g, 39g,... And the slits 71, 71 is maintained constant. In FIG. 4, the hatching of the movable plate 41 and the lower main body portion 49 is omitted in order to make the slope portions 39g, 39g,.

  In the engine mount 1 of the present embodiment configured as described above, the vibration in the high frequency region is absorbed by the elastic deformation of the rubber elastic body 7 during normal vibration input. At this time, large amplitude vibrations in a low frequency region such as an engine shake are absorbed and damped by the liquid column resonance action caused by the flow of the liquid in the orifice passage 19. Further, for engine vibration with relatively high frequency and small amplitude, such as idle vibration, the fluid pressure fluctuation in the pressure receiving chamber 21 is absorbed by the movable plate 41 vibrating in synchronization with this vibration.

  On the other hand, when a large vibration is input to the engine mount 1 and the pressure receiving chamber 21 is in a negative pressure state, such as when an automobile wheel rides on a curb or the like, an axis line is formed in the accommodation chamber 29 formed inside the orifice plate 9. The peripheral portion 61 of the movable plate 41 accommodated so as to be movable in the Z direction is pressed against the lower surface of the inner side wall 39c.

  Here, since the space 29b exists in the central portion of the accommodation chamber 29, even when the peripheral portion 61 of the movable plate 41 is pressed against the lower surface of the inner side wall portion 39c, the central portion 51 is The deformation is not restricted and the thickness in the direction of the axis Z is thin, so that it deforms so as to swell toward the pressure receiving chamber 21 in the space 29b. Then, when the upper projection 51a formed on the upper surface of the central portion 51 and projecting toward the pressure receiving chamber 21 comes into contact with the lower surface of the central top wall portion 39d, as shown in FIG. 51a serves as a fulcrum, and the portion where the cut slits 71, 71 of the central portion 51 of the movable plate 41 are formed is more easily deformed, whereby the cut slit 71 formed at the outer peripheral end of the central portion 51. , 71 open.

  By opening the slits 71 and 71 in this way, the liquid can easily flow from the equilibrium chamber 31 side to the pressure receiving chamber 21 side, and the pressure receiving chamber 21 side is quickly depressurized, thereby suppressing the occurrence of cavitation.

  On the other hand, when the inside of the pressure receiving chamber 21 is in a positive pressure (pressed) state, the movable plate 41 is pressed against the upper surface of the bottom wall portion 49a of the orifice plate 9, but the thickness in the axis Z direction of the central portion 51 is set to the peripheral portion 61. Since the space 29c for allowing elastic deformation of the movable plate 41 toward the balance chamber 31 is present below the movable plate 41 by making the thickness smaller than the thickness in the axis Z direction, The deformation of 51 is not restricted. By utilizing such elastic deformation of the central portion 51, an increase in the hydraulic pressure in the pressure receiving chamber 21 is absorbed, so that the dynamic spring constant is larger than when no space exists below the movable plate 41. It is possible to suppress the rise.

  Further, when the increase in the hydraulic pressure in the pressure receiving chamber 21 is large, the central portion 51 is further deformed so as to swell toward the equilibrium chamber 31 in the space, and is formed on the lower surface of the central portion 51. A lower protrusion 51b protruding in contact with the upper surface of the bottom wall 49a. Thus, when the lower projection 51b contacts the upper surface of the bottom wall portion 49a, the lower projection 51b serves as a fulcrum to form the cut slits 71 and 71 in the central portion 51 of the movable plate 41. This makes it easier to deform the part. Thereby, the slits 71 and 71 formed at the outer peripheral end of the central portion 51 are opened, and the liquid easily flows from the pressure receiving chamber 21 side to the equilibrium chamber 31 side, and an excessive increase in the hydraulic pressure in the pressure receiving chamber 21 is suppressed. .

-Effect-
According to this embodiment, a space 29 b for allowing elastic deformation of the movable plate 41 toward the pressure receiving chamber 21 is present in the central portion of the storage chamber 29 on the pressure receiving chamber 21 side of the movable plate 41. Therefore, even when the peripheral portion 61 is pressed against the lower surface of the inner wall 39c of the orifice board 9, the central portion 51 of the movable plate 41 swells toward the pressure receiving chamber 21 without being restricted from being deformed. It deforms as follows. As a result, a slit 71 formed so as to penetrate in the direction of the axis Z opens in a portion corresponding to the space 29b, and the liquid easily flows from the equilibrium chamber 31 side to the pressure receiving chamber 21 side. To reduce the occurrence of cavitation.

  Further, since the thickness of the central portion 51 of the movable plate 41 in the axis Z direction is thinner than the thickness of the peripheral portion 61 in the axis Z direction, the upper surface of the bottom wall portion 49a of the orifice plate 9 is formed flat. Even in such a case, by adjusting the position of the central portion 51 relative to the peripheral edge portion 61 in the axis Z direction, a space for allowing elastic deformation of the movable plate 41 in the axis Z direction can be easily secured. Furthermore, since the thickness of the central portion 51 of the movable plate 41 in the axis Z direction is thin, the central portion 51 is more easily deformed.

(Other embodiments)
The present invention is not limited to the embodiments, and can be implemented in various other forms without departing from the spirit or main features thereof.

  In the embodiment described above, the protrusions 51a and 51b are formed on the upper and lower surfaces of the central portion 51 of the movable plate 41. However, the present invention is not limited to this, and for example, as shown in FIG. In order to promote the deformation of the movable plate 41 toward the equilibrium chamber 31 at this time, the lower protrusion 51b may be formed only on the lower surface of the central portion 51. On the contrary, the pressure receiving chamber 21 has a negative pressure. The upper protrusion 51 a may be formed only on the upper surface of the central portion 51 in order to promote deformation of the movable plate 41 toward the pressure receiving chamber 21 when in the state.

  Moreover, in the said embodiment, although protrusion part 51a, 51b was formed one each on the upper and lower surfaces of the center part 51 of the movable plate 41, it is not restricted to this, For example, as shown in FIG.6 (b), a center part A plurality of lower projections 51b, 51b may be formed on the lower surface of 51, and as shown in FIG. 6C, a plurality of projections 51a, 51a, 51b, 51b and 51b may be formed. As described above, when the plurality of protrusions 51a, 51b,... Are formed, the protrusions 51a, 51b,... Come into contact with the lower surface of the central top wall portion 39d of the orifice plate 9 or the upper surface of the bottom wall portion 49a. , And the abnormal noise generated when the tips of the protrusions 51a, 51b,... Abut against the central top wall 39d or the bottom wall 49a can be further reduced.

  Furthermore, in the said embodiment, although the projection parts 51a and 51b were formed in the movable plate 41, it is not restricted to this, For example, when the center part 51 of the movable plate 41 deform | transforms as shown to Fig.7 (a). An upper projecting portion 9a projecting toward the equilibrium chamber 31 side is formed on the lower surface of the central top wall portion 39d of the orifice panel 9 so as to contact the central portion 51, and the pressure receiving chamber 21 side is formed on the upper surface of the bottom wall portion 49a. You may make it form the lower protrusion part 9b which protrudes in this. Further, as shown in FIG. 7B, a lower protrusion 51b is formed on the lower surface of the central portion 51 so as to promote deformation of the movable plate 41 toward the equilibrium chamber 31 when the pressure receiving chamber 21 is in a positive pressure state. At the same time, in order to promote the deformation of the movable plate 41 toward the pressure receiving chamber 21 when the pressure receiving chamber 21 is in a negative pressure state, an upper protrusion projecting toward the balance chamber 31 on the lower surface of the central top wall portion 39d of the orifice plate 9 is provided. You may make it form the part 9a.

  In the above embodiment, the movable plate 41 is formed so that the upper surface of the central portion 51 and the upper surface of the peripheral portion 61 are flush with each other, but the thickness of the central portion 51 in the axis Z direction is the axis of the peripheral portion 61. If it is thinner than the thickness in the Z direction, the present invention is not limited to this. For example, as shown in FIG. 8A, the central portion 51 is positioned at the central portion in the axis Z direction of the peripheral portion 61. The movable plate 41 may be formed. In this way, even if both the lower surface of the top wall portion 39a and the upper surface of the bottom wall portion 49a of the orifice plate 9 are formed flat (more specifically, the central top wall 39c of the upper body portion 39 is centered). Even if the wall 39d is not provided, a space for allowing elastic deformation in the axis Z direction of the movable plate 41 exists in the central portion of the storage chamber 29. Accordingly, the orifice board 9 can be easily manufactured.

  Furthermore, in the said embodiment, although the movable plate 41 was formed so that the upper surface of the center part 51 and the upper surface of the peripheral part 61 might become the same, it is not restricted to this, For example, as shown in FIG.8 (b) A step may be provided so that the upper surface of the central portion 51 protrudes closer to the pressure receiving chamber 21 than the upper surface of the peripheral portion 61. In this way, when the peripheral portion 61 of the movable plate 41 is pressed against the lower surface of the inner wall 39c, the central portion 51 is easily fitted in the space 29b. It is possible to reliably perform elastic deformation.

  Moreover, in the said embodiment, although the two slits 71 and 71 were formed so that the outer periphery of the center part 51 might be followed, it is not restricted to this, For example, as shown to Fig.9 (a), the slits 71 and 71 are cut | disconnected. ,... May be formed, or eight slits 71, 71,... May be formed as shown in FIG. Thus, if the length of each slit 71 is shortened, the ease of opening is inferior, but the vibration damping function during normal vibration input can be easily maintained. In these cases as well, it is desirable to form protrusions 61a, 61a,... At portions corresponding to the ends 71a of the respective slits 71.

  Furthermore, in the said embodiment, although the slits 71 and 71 were formed so that the outer periphery of the center part 51 might be followed, not only this but the slits 71 and 71 are shown, for example in FIG.9 (c), It may be formed in a semicircular arc shape protruding toward the center of the central portion 51, or may be formed in a straight line passing through the center of the central portion 51 as shown in FIG. 9 (d). ) May be formed in a cross shape that intersects at the center of the central portion 51, or may be formed in a straight line that does not pass through the center of the central portion 51, as shown in FIG. Also in these cases, both ends 71a, 71a of each cut slit 71 are positioned at the boundary between the central portion 51 and the peripheral portion 61, and the protrusions are formed at portions corresponding to the ends 71a of the cut slits 71. It is desirable to form 61a, 61a,. Moreover, in the thing of FIG.9 (c) and (f) in which the notch slit 71 is not formed in the center part of the center part 51, you may form upper side and / or lower side protrusion part 51a, 51b.

  Further, in the above embodiment, the central portion 51 is positioned so that the outer peripheral edge of the central portion 51 is located between the outer through holes 39e, 39e,... And the inner through holes 39f, 39f,. 51, but the central portion 51 is extremely (the outer peripheral edge of the central portion 51 is located on the inner side of the inner through holes 39f, 39f,..., And the through holes 39e, 39f,. It is small enough to be closed, or extremely (the outer peripheral edge of the central portion 51 is positioned outside the outer through holes 39e, 39e,..., And the through holes 39e, 39f,. Any size is acceptable as long as it is not big enough.

  Furthermore, in the said embodiment, although slope part 39g, 39g, ... was formed in the internal peripheral surface of the inner side wall part 39c of the upper side main-body part 39, if the ease of the flow of a liquid can be ensured, slope part 39g, 39g, ... need not be formed.

  Moreover, in the said embodiment, although the resin-made orifice board 9 was used, you may use not only this but an iron plate-made orifice board, for example.

  Furthermore, in the said embodiment, although the protrusion part 61a which protrudes to a radial inside is formed in the part corresponding to the edge 71a of the cut slit 71, the protrusion part 61a does not necessarily need to be formed.

  In the above embodiment, the liquid-filled vibration isolator of the present invention is applied to the so-called vertical engine mount 1. However, the present invention is not limited thereto, and can be applied to a horizontal engine mount. It can be applied not only to engine mounts but also to suspension bushings. Furthermore, it is not limited to automobile use.

  As described above, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  As described above, the present invention is useful for a liquid-filled vibration isolator having a notch formed in a movable plate for absorbing fluid pressure fluctuations in the main liquid chamber.

1 Engine mount (liquid-filled vibration isolator)
3 Connecting bracket 5 Support bracket 7 Rubber elastic body 9 Orifice panel (partition member)
9a Upper projection (projection)
9b Lower projection (projection)
11 Liquid chamber 19 Orifice passage 21 Pressure receiving chamber (main liquid chamber)
29 Storage chamber 29b Space 29c Space 31 Equilibrium chamber (sub-liquid chamber)
39e Through hole (communication hole)
39f Through hole (communication hole)
41 Movable plate 49d Through hole (communication hole)
51 Central portion 51a Upper protrusion (protrusion)
51b Lower protrusion (protrusion)
61 Peripheral part 61a Protruding part 71 Cut slit 71a End Z axis

Claims (6)

A coupling metal connected to the supported side, a support metal connected to the support, and a rubber elastic body that connects both the metal parts and relatively displaces the metal parts in the axial direction connecting at least the two metal parts by elastic deformation. And a liquid chamber formed between the connection fitting and the support fitting so that the volume changes with deformation of the rubber elastic body, and the interior of the liquid chamber is divided into a main liquid chamber and a sub liquid chamber A partition member, an orifice passage communicating the main liquid chamber and the sub liquid chamber, and a movable plate housed in a housing chamber formed inside the partition member so as to be movable in the axial direction. A liquid-filled vibration isolator,
The partition member is formed with a communication hole for communicating the storage chamber with each of the main liquid chamber and the sub liquid chamber,
In the central portion of the storage chamber, there is a space for allowing elastic deformation of the movable plate toward the main liquid chamber side and the sub liquid chamber side,
In the movable plate, a central portion corresponding to the space is formed in a substantially disc shape, a peripheral portion around the central portion is formed in a substantially annular shape, and an axial thickness of the central portion is , Thinner than the axial thickness of the peripheral portion,
A liquid filled type vibration damping device, wherein a cut slit penetrating in an axial direction is formed in a central portion of the movable plate. The liquid-filled vibration isolator according to claim 1,
The liquid-filled vibration isolator, wherein the slits are formed so that both ends thereof are located at the boundary between the central portion and the peripheral portion of the movable plate. The liquid-filled vibration isolator according to claim 2,
On the inner peripheral surface of the peripheral portion of the movable plate, in order to prevent the cut of the cut slit from proceeding along the outer periphery of the central portion, the portion corresponding to the end of the cut slit is radially inward. A liquid-filled vibration isolator having a protruding portion that protrudes. In the liquid enclosure type vibration isolator as described in any one of Claims 1-3,
In the central portion of the movable plate where the slits are not formed, when the movable plate is deformed, the partition member is in contact with a surface that is orthogonal to the axial direction and partitions the space. A liquid-filled type vibration damping device, characterized in that a projecting portion is formed on the main liquid chamber side and / or the sub liquid chamber side. In the liquid enclosure type vibration isolator as described in any one of Claims 1-4,
On the surface of the partition member that is orthogonal to the axial direction and that divides the space, when the movable plate is deformed, the main liquid chamber side and / or the auxiliary liquid are brought into contact with the central portion of the movable plate. A liquid-filled vibration isolator having a projecting portion protruding toward the chamber. In the liquid-filled vibration isolator according to any one of claims 1 to 5,
The space is formed by denting a surface of the partition member perpendicular to the axial direction and defining the storage chamber to the main liquid chamber side and / or the sub liquid chamber side,
A liquid part characterized in that a slope portion that inclines radially outward toward the movable plate side is partially formed on a surface of the partition member parallel to the axial direction and partitioning the space. Enclosed vibration isolator.

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