JP4555364B2 - Liquid-filled vibration isolator - Google Patents

Description

  The present invention relates to a liquid-filled vibration isolator.

  Conventionally, as described in, for example, Patent Document 1 below, a first fixture, a cylindrical second fixture, and a rubber-like elastic material that connects the first fixture and the second fixture. A diaphragm comprising a vibration base and a rubber film attached to the second fixture and forming a liquid sealing chamber between the vibration isolating base and the first liquid chamber and the diaphragm side on the side of the vibration isolating base. A partition body for partitioning into the second liquid chamber and an orifice for communicating the first liquid chamber and the second liquid chamber, and forming the partition body with an elastic partition film and an annular orifice for housing the elastic partition film. 2. Description of the Related Art There is known a liquid-filled vibration isolator that includes a member and a first lattice portion and a second lattice portion that restrict the amount of displacement of the elastic partition film from both sides of the film surface.

  In such a liquid filled type vibration isolator, when a large amplitude low frequency vibration occurs, the liquid flows through the orifice between the first liquid chamber and the second liquid chamber, and the vibration is attenuated by the liquid flow effect. Further, when high-frequency vibration with a small amplitude is generated, the elastic partition film is reciprocally deformed to absorb the liquid pressure in the first liquid chamber and reduce the vibration. According to the above-described conventional structure, the impact when the elastic partition membrane collides with the first lattice portion and the second lattice portion is transmitted to the second attachment device through the rigid orifice forming member, and from the second attachment device. There is a problem that noise is transmitted to the vehicle body side and causes noise in the vehicle interior.

On the other hand, the following Patent Document 2 discloses a partition for partitioning the first liquid chamber and the second liquid chamber for the purpose of preventing abnormal noise due to impact from being transmitted to the vehicle interior without impairing the above-mentioned vibration isolation characteristics. It has been proposed to construct the body as follows. That is, the partition body is a pair of partitions that are connected to each other via an annular orifice forming member, a rubber wall that closes between the inner peripheral surfaces, and a connecting portion that penetrates the rubber wall and sandwiches the rubber wall in the axial direction. The displacement amount in the axial direction of the pair of partition plates is regulated by the rubber wall.
JP 2006-144806 A JP 2006-207672 A

  With the configuration disclosed in Patent Document 2, the displacement amount of the pair of partition plates is regulated by the rubber wall, so that the vibration is attenuated by the liquid flow effect by the orifice with respect to the large amplitude vibration in the low frequency range. The vibration can be reduced by reducing the dynamic spring constant due to the reciprocating motion of the partition plate against the minute amplitude vibration in the high frequency range. In addition, since the partition plate is supported by the rubber wall, it is possible to suppress transmission of abnormal noise into the vehicle interior.

  As described above, according to the configuration disclosed in Patent Document 2, it is possible to achieve both the damping performance in the low frequency range and the low dynamic spring in the high frequency range, but recently, the required level is further increased. . In response to this requirement, for example, when the rubber wall is made thin overall or the elastic modulus of the material constituting the rubber wall is lowered, the partition plate can be easily reciprocated with respect to high-frequency vibrations, and the dynamic spring constant is set. Can be reduced. On the other hand, however, the above measures impair the effect of restricting displacement of the partition plate by the rubber wall during low-frequency, large-amplitude vibration, and decrease the damping performance.

  The present invention has been made in view of the above points, and achieves both a higher level of damping performance improvement for low-frequency large-amplitude vibration and a reduction in dynamic spring constant for high-frequency fine-amplitude vibration than ever before. An object of the present invention is to provide a liquid-sealed vibration isolator that can be used.

  The liquid-filled vibration isolator according to the present invention includes a first mounting tool, a cylindrical second mounting tool, and a vibration-proof base made of a rubber-like elastic material that connects the first mounting tool and the second mounting tool. A diaphragm made of a rubber-like elastic film that is attached to the second fixture and forms a liquid sealing chamber between the vibration isolating substrate and the first liquid chamber on the side of the vibration isolating substrate. A partition body for partitioning into a second liquid chamber on the diaphragm side, and an orifice for communicating the first liquid chamber and the second liquid chamber are provided. The partition body is provided with an annular orifice forming member that is provided inside the peripheral wall portion of the second fixture and that forms the orifice, and an elastic material made of a rubber-like elastic material that blocks between the inner peripheral surface of the orifice forming member. The wall includes a pair of partition plates that are connected to each other via a connecting portion that penetrates the radial center of the elastic wall and sandwiches the elastic wall in the axial direction of the elastic wall. The elastic wall includes a boundary line portion extending in the circumferential direction, a thin wall portion having a wall surface arranged to face and separate from the plate surface of the partition plate on the inner peripheral side of the boundary line portion, On the outer peripheral side of the boundary line portion, a thick wall is formed with a stepped thickness with respect to the thin wall portion with the boundary line portion as a boundary, and the radially outer side between the partition plate and the plate surface. And a thick wall portion having a wall surface that forms a gradually widening gap.

  According to the above configuration, the elastic wall is partitioned and formed by the boundary line portion into the thin wall portion on the inner peripheral side and the thick wall portion on the outer peripheral side, and the thin wall portion on the inner peripheral side is between the partition plate. It is formed away from the partition plate so as to ensure a predetermined clearance. For this reason, the thin wall portion serves as a low-rigidity portion and the partition plate can be easily reciprocated in the axial direction with respect to fine amplitude vibration in a high frequency range, and the dynamic spring constant can be reduced. On the other hand, for large amplitude vibrations in the low frequency range, the thick wall portion on the outer peripheral side disposed opposite to the partition plate through a gap gradually widening toward the radially outer side is a partition plate as a high-rigidity portion. The reciprocating displacement can be effectively regulated. Therefore, the improvement of the damping performance for the low frequency large amplitude vibration and the reduction of the dynamic spring constant for the high frequency fine amplitude vibration can be achieved at a high level.

  In the above configuration, the boundary line portion may be formed thinner than the thin wall portion by a groove extending in the circumferential direction provided on at least one wall surface of the elastic wall. In this way, by forming the boundary line portion between the thin wall portion and the thick wall portion as a low-rigidity portion that is thinner than the thin wall portion, the partition plate is arranged in the axial direction against high-frequency fine amplitude vibration. By making it easier to reciprocate, the dynamic spring constant can be reduced.

  In the above configuration, the distance between the wall surface of the thin wall portion and the plate surface of the partition plate facing the wall surface is the same as the wall surface of the thick wall portion and the plate surface of the partition plate facing the wall surface. It may be set larger than the maximum dimension of the gap. By setting in this way, the reciprocating range of the partition plate is determined by the gap in the thick wall portion on the outer peripheral side, and the thin wall portion on the inner peripheral side is prevented from contacting the partition plate even during large amplitude vibration. be able to. Therefore, it is possible to prevent abnormal noise due to the collision between the thin wall portion on the inner peripheral side and the partition plate during large amplitude vibration.

  In the above configuration, the thick wall portion contacts the plate surface of the partition plate at the inner peripheral edge, and the wall surface of the thick wall portion is between the plate surface of the partition plate on the outer peripheral side of the contact portion. The gap may be formed so as to gradually increase toward the radially outer side. In this way, by causing the inner peripheral edge of the thick wall portion to be in contact with the partition plate, it is possible to prevent the generation of noise due to the collision between the two. Further, since only the inner peripheral edge is in contact, the reciprocating displacement of the partition plate by the thin wall portion at the time of high frequency fine amplitude is not hindered. In addition, by providing the gap that gradually widens on the outer peripheral side of the contact portion, the contact area between the thick wall portion and the partition plate increases sequentially and smoothly from the inner peripheral side to the outer peripheral side during large amplitude vibration. The effect of restricting the displacement of the partition plate can be enhanced without causing abnormal noise.

  In the above-described configuration, the wall surface of the thick wall portion and the plate surface of the partition plate facing the wall surface are each in the form of an inclined surface positioned radially outward in the axial direction of the elastic wall. The thin wall portion may be formed with a constant thickness in the radial direction. Thereby, the said displacement control effect of the partition plate in large amplitude vibration and the said reciprocating displacement effect of the partition plate at the time of a high frequency fine amplitude vibration can be exhibited more effectively.

  In the above-described configuration, the outer peripheral portion of the elastic wall that is bonded and fixed to the inner peripheral surface of the orifice forming member protrudes outward in the axial direction with respect to the inclined wall surface of the thick wall portion. A raised portion that increases the rigidity of the outer peripheral portion of the elastic wall may be provided. By providing such a raised portion, it is possible to increase the rigidity of the outer peripheral portion of the elastic wall and further enhance the effect of restricting the displacement of the partition plate during large amplitude vibration.

  In the above configuration, even if a convex portion that protrudes radially inward and increases the rigidity of the outer peripheral portion of the elastic wall is provided on the inner peripheral surface of the orifice forming member to which the outer peripheral portion of the elastic wall is bonded and fixed. Good. By providing such a convex part, the rigidity of the outer peripheral part of an elastic wall can be raised and the displacement control effect of a partition plate at the time of a large amplitude vibration can further be heightened.

  In the above configuration, the outer peripheral portion of the elastic wall that is bonded and fixed to the inner peripheral surface of the orifice forming member has the inclined surface shape of the thick wall portion on the wall surface on the first liquid chamber side of the elastic wall. A raised portion that protrudes toward the first liquid chamber side with respect to the wall surface is provided, and a tip of the raised portion is provided so as to be positioned closer to the first liquid chamber side than the first liquid chamber side end of the orifice forming member. Good. In addition, a convex portion projecting radially inward is provided on the inner peripheral surface of the orifice forming member to which the outer peripheral portion of the elastic wall is bonded and fixed at the base portion of the elastic wall on the second liquid chamber side. The side surface of the convex portion on the second liquid chamber side is formed on a straight surface orthogonal to the axial direction of the elastic wall, and the side surface of the convex portion on the second liquid chamber side is formed when the elastic wall is formed. It may be a pressing surface in the axial direction with respect to the molding die.

  By providing such a raised part and a convex part, the rigidity of the outer peripheral part of an elastic wall can be raised and the displacement control effect of the partition plate at the time of a large amplitude vibration can further be heightened. Further, on the first liquid chamber side of the partition body, a protruding portion is provided on the elastic wall as a means for increasing the rigidity, and since this protruding portion is made of a rubber-like elastic material, the vibration-proof base is excessively displaced. Even when it hits the raised portion, it is possible to prevent the vibration-proof substrate from being damaged. Further, on the second liquid chamber side of the partition, a convex portion is provided on the inner peripheral surface of the orifice forming member as a means for increasing the rigidity, and the side surface of the convex portion on the second liquid chamber side is defined as the axial direction. It is formed on an orthogonal straight surface. Therefore, at the time of molding the elastic wall, the mold can be pressed against the side surface of the straight convex part to seal the rubber-like elastic material so that it does not leak out of the cavity, thereby suppressing the generation of burrs. Can do.

  As described above, according to the present invention, it is possible to achieve both a high level of improvement in damping performance against low-frequency large-amplitude vibration and a reduction in dynamic spring constant against high-frequency fine-amplitude vibration.

  Hereinafter, a liquid-filled vibration isolator according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a longitudinal sectional view of a liquid-filled vibration isolator 10 according to an embodiment. The vibration isolator 10 includes an upper first attachment 12 attached to an automobile engine, a lower cylindrical second attachment 14 attached to a vehicle body frame, and a rubber-like elastic material for connecting them. And an anti-vibration substrate 16.

  The first fixture 12 is a cylindrical metal fitting disposed above the axial center portion of the second fixture 14, and a stopper portion 18 that protrudes in a flange shape toward the radially outward Ko is formed at the lower end portion. Yes. Further, a mounting bolt 20 protrudes upward at the upper end and is configured to be attached to the engine side via the bolt 20.

  The second fixture 14 includes a cylindrical tubular fitting 22 and a cup-shaped bottom fitting 24 on which the vibration-proof base 16 is vulcanized, and a downward mounting bolt 26 projects from the center of the bottom fitting 24. It is configured to be attached to the vehicle body side via the bolt 26. The lower end of the cylindrical fitting 22 is fixed by caulking to the upper end opening of the bottom fitting 24 by a caulking portion 28. Reference numeral 30 denotes a stopper fitting fixed by caulking to the upper end portion of the cylindrical fitting 22, and exerts a stopper action with the stopper portion 18 of the first fixture 12. Reference numeral 32 denotes a stopper rubber that covers the upper surface of the stopper fitting 30.

  The anti-vibration base 16 is formed in a truncated cone shape, and its upper end is vulcanized and bonded to the first fixture 12 and its lower end is vulcanized and bonded to the upper end opening of the cylindrical fitting 22. A rubber film-like seal wall portion 34 covering the inner peripheral surface of the cylindrical metal fitting 22 is connected to the lower end portion of the vibration isolation base 16.

  A diaphragm 38 made of a flexible rubber film is attached to the second fixture 14 so as to face the lower surface of the vibration-isolating base 16 in the axial direction X and form a liquid sealing chamber 36 between the lower surface. The liquid is enclosed in the liquid enclosure chamber 36. The liquid enclosure chamber 36 is partitioned by a partition 40 into a first liquid chamber 36A on the vibration isolation base 16 side and a second liquid chamber 36B on the diaphragm 38 side. The first liquid chamber 36A and the second liquid chamber 36B. Are communicated with each other through an orifice 42 as a throttle channel. The first liquid chamber 36A is a main liquid chamber in which the vibration isolation base 16 forms part of the chamber wall, and the second liquid chamber 36B is a sub-liquid chamber in which the diaphragm 38 forms part of the chamber wall.

  As shown in FIGS. 1 and 2, the partition 40 includes an annular orifice forming member 44 provided inside a cylindrical peripheral wall portion 14 </ b> A of the second fixture 14, and an inner peripheral surface of the orifice forming member 44. 44A includes an elastic wall 46 made of a rubber elastic body in which the outer peripheral portion 46A is vulcanized and bonded to the inner peripheral surface 44A, and a pair of upper and lower partition plates 48 and 50 that sandwich the elastic wall 46 in the axial direction X thereof. Become.

  The orifice forming member 44 is a member made of a rigid body that forms an orifice 42 extending in the circumferential direction C (see FIG. 5) between the peripheral wall portion 14A of the second fixture 14 and the inner periphery of the peripheral wall portion 14A. The seal wall 34 is fitted. More specifically, the orifice forming member 44 includes a cylindrical portion 44B disposed coaxially with the peripheral wall portion 14A of the second fixture 14, and outwardly in a U-shaped cross section on the outer peripheral side of the cylindrical portion 44B. An open groove 44C is provided. The inner peripheral surface of the cylindrical portion 44B is the inner peripheral surface 44A. Further, the orifice 42 is formed between the groove portion 44 </ b> C and the peripheral wall portion 14 </ b> A of the second fixture 14.

  As shown in FIG. 1, the orifice forming member 44 is clamped and fixed by a reinforcing metal fitting 38 </ b> A embedded in the outer peripheral edge of the diaphragm 38 and a receiving step 16 </ b> A formed on the outer periphery of the lower end of the vibration isolating base 16. ing. Specifically, a reinforcing metal fitting 38A provided on the outer peripheral edge portion of the diaphragm 38 is fixed by caulking portions 28 of the second mounting tool 14, and via a rubber portion of the diaphragm 38 covering the inner peripheral edge portion of the reinforcing metal fitting 38A. The lower end portion of the orifice forming member 44 is supported by the reinforcing metal fitting 38A.

  In FIG. 5, reference numeral 52 is a first opening for communicating the orifice 42 and the first liquid chamber 36A, and reference numeral 54 is a second opening for communicating the orifice 42 and the second liquid chamber 36B. It is provided on the forming member 44.

  The elastic wall 46 has a circular shape in plan view, and its outer peripheral portion 46A is vulcanized and bonded to the inner peripheral surface 44A of the cylindrical portion 44B of the orifice forming member 44 as shown in FIG. The elastic wall 46 includes a circular through hole 56 that penetrates in the axial direction X at the radial center, and annular ridges 58 that project in the axial direction X are provided on both front and back sides around the through hole 56. It has been.

  As shown in FIG. 2, the pair of partition plates 48 and 50 are connected to each other via a columnar connecting portion 60 that passes through the through hole 56, and are integrally formed by a rigid body such as a resin material. One (upper side) partition plate 48 of them constitutes a part of the chamber wall of the first liquid chamber 36A, that is, is arranged facing the first liquid chamber 36A. Further, the other (lower) partition plate 50 constitutes a part of the chamber wall of the second liquid chamber 36B, that is, is arranged facing the second liquid chamber 36B. The displacement amount in the axial direction X of the pair of partition plates 48 and 50 is restricted by the elastic wall 46.

  The connecting portion 60 is configured by fixing the tip end surfaces of columnar connecting convex portions 60A provided at the center portions of the upper and lower partition plates 48 and 50 by ultrasonic welding or the like. Around the connecting portion 60, annular grooves 62 are provided in which the upper and lower ridges 58 of the elastic wall 46 are fitted. Further, a circular pinching protrusion 63 is provided around the annular groove 62 so as to protrude in the axial direction X and hold the elastic wall 46 from both the front and back sides.

  The pair of partition plates 48 and 50 are formed to have an outer shape smaller than that of the elastic wall 46 in plan view (see FIGS. 2 and 5). That is, the outer peripheral edges 48A, 50A of the partition plates 48, 50 are terminated on the radially inner side Ki side of the inner peripheral surface 44A of the orifice forming member 44 where the outer peripheral edge of the elastic wall 46 is located.

  As shown in FIGS. 4 and 6, the elastic wall 46 includes a boundary line portion 64 extending in the circumferential direction C, a thin wall portion 66 provided on the inner peripheral side of the boundary line portion 64, and an outer peripheral side of the boundary line portion 64. And a thick wall 68 provided on the wall.

  The boundary line portion 64 is a ring-shaped boundary portion that divides the thin wall portion 66 and the thick wall portion 68. In this example, the boundary line portion 64 is approximately between the connecting portion 60 and the orifice forming member 44 in the radial direction K. The center position is set (see FIG. 2). Further, the boundary line portion 64 is a concave groove 70 extending in the circumferential direction C provided on both the front and back wall surfaces of the elastic wall 46 (that is, the wall surface on the first liquid chamber 36A side and the wall surface on the second liquid chamber 36B side). Thus, it is formed as a low rigidity portion that is thinner than the thin wall portion 66 on the inner peripheral side. The concave groove 70 is formed in a circular shape in plan view extending continuously over the entire circumference in the circumferential direction C.

  The thin wall portion 66 is a ring-shaped elastic wall portion adjacent to the inner peripheral side of the boundary line portion 64 as shown in FIG. 6, and between the pair of partition plates 48 and 50 as shown in FIG. Are spaced apart from each other in the axial direction X. That is, the front and back wall surfaces 66A of the thin wall portion 66 are disposed to face and separate from the plate surfaces 48B and 50B of the partition plates 48 and 50 (see FIG. 3). On both sides, a predetermined space 72 filled with liquid is secured between the partition plates 48 and 50.

  As shown in FIG. 4, the thin wall portion 66 is formed in a flat plate shape having a constant thickness in the radial direction K. As shown in FIG. 3, the inner peripheral edge portion of the thin wall portion 66 is held in a compressed state in the axial direction X by the pressing protrusions 63 and 63 of the pair of partition plates 48 and 50. Therefore, the predetermined space 72 is secured between the thin wall portion 66 and the partition plates 48 and 50 on the radially outer side Ko of the sandwiched inner peripheral edge portion. Further, in this portion, the first plate surfaces 48B, 50B of the partition plates 48, 50 facing the thin wall portion 66 are formed in a straight surface shape orthogonal to the axial direction X, so that the space 72 is formed in the radial direction K. Are formed at regular intervals.

  On the other hand, as shown in FIG. 4, the thick wall portion 68 is thickened in a stepped manner on the outer peripheral side of the boundary line portion 64 with respect to the thin wall portion 66 with the boundary line portion 64 as a boundary. Is formed. That is, the thick wall portion 68 is formed in a thick shape outside the discontinuous portion by being discontinuously thickened so that the wall thickness suddenly changes from the boundary line portion 64. As shown in FIG. 6, the thick wall portion 68 is a ring-shaped elastic wall portion adjacent to the outer peripheral side of the boundary line portion 64.

  As shown in FIG. 3, the thick wall portion 68 includes a wall surface 68 </ b> A that forms a gap 74 that gradually increases toward the radially outward Ko side between the second plate surfaces 48 </ b> C and 50 </ b> C of the partition plates 48 and 50. It is formed on both the front and back sides. Specifically, the thick wall portion 68 is in contact with the second plate surfaces 48C and 50C of the upper and lower partition plates 48 and 50 at the inner peripheral edge thereof, and on the outer peripheral side of the contact portion 76, the thick wall wall 68 is provided. The wall surface 68A of the portion 68 forms the gap 74 that gradually increases toward the radially outward Ko side between the second plate surfaces 48C and 50C of the partition plates 48 and 50 facing the wall surface 68A. The contact portion 76 is preferably configured to contact the thick wall portion 68 without being pressed in the axial direction X, and is provided in a line contact state over the entire circumference in the circumferential direction C.

  Further, the wall surface 68A of the thick wall portion 68 and the second plate surfaces 48C and 50C of the partition plates 48 and 50 facing the wall surface 68A are closer to the axially outward Xo side of the elastic wall 46 toward the radially outward Ko side. It is formed in the shape of an inclined surface. Therefore, the thick wall portion 68 is gradually formed thicker toward the radially outward Ko side. In addition, the slopes of the inclined surfaces of the second plate surfaces 48C and 50C of the partition plates 48 and 50 are set to be slightly larger than the inclined surfaces of the wall surface 68A of the thick wall portion 68. The gap 74 is formed so as to gradually become wider toward the side Ko.

  As shown in FIG. 3, the distance between the wall surface 66 </ b> A of the thin wall portion 66 and the first plate surfaces 48 </ b> B and 50 </ b> B of the partition plates 48 and 50 facing the wall surface 66 </ b> A is the wall surface of the thick wall portion 68. 68A and the second plate surfaces 48C and 50C of the partition plates 48 and 50 opposed thereto, which are larger than the maximum dimension of the gap 74 (the gap in the axial direction X of the gap 74 at the radially outer end). Is set. Thereby, even when a large amplitude vibration is input, the thin wall portion 66 does not contact the partition plates 48 and 50, and the range of movement of the partition plates 48 and 50 is only the gap 74 in the thick wall portion 68 on the outer peripheral side. It is comprised so that it may be prescribed | regulated.

  Further, in order to increase the rigidity of the base portion of the elastic wall 46 with respect to the orifice forming member 44 and enhance the displacement regulating effect of the pair of partition plates 48 and 50 at the time of low frequency and large amplitude, the following configuration is adopted. Yes.

  That is, first, the outer peripheral portion 46A of the elastic wall 46 bonded and fixed to the inner peripheral surface 44A of the orifice forming member 44 has an inclined surface shape of the thick wall portion 68 on the wall surface on the first liquid chamber 36A side. A raised portion 78 is provided to protrude from the wall surface 68 </ b> A toward the axially outward Xo side, i.e., the first liquid chamber 36 </ b> A side. As shown in FIG. 6, the raised portion 78 has an annular shape extending over the entire circumferential direction C. Further, as shown in FIG. 3, the protruding portion 78 has a tip end (that is, an outer end in the axial direction X) 78 </ b> A that is closer to the first liquid chamber 36 </ b> A than the first liquid chamber side end 44 </ b> D of the orifice forming member 44. Located on the side. Further, the raised portion 78 is formed so as to protrude beyond the upper surface of the partition plate 48 on the first liquid chamber 36A side toward the axial direction outward Xo side.

  Second, the inner peripheral surface 44A of the orifice forming member 44 to which the outer peripheral portion 46A of the elastic wall 46 is bonded and fixed protrudes radially inward Ki at the base portion of the elastic wall 46 on the second liquid chamber 36B side. A convex portion 80 is provided. As shown in FIG. 3, the convex portion 80 is formed in an inclined surface shape in which the side surface 80A of the elastic wall 46 in the axial direction X center side is positioned on the radially inner side Ki toward the axial direction outward Xo side. In addition, the side surface 80B on the second liquid chamber 36B side is formed on a straight surface orthogonal to the axial direction X of the elastic wall 46. The side surface 80B on the second liquid chamber side having a straight surface is a portion used as a pressing surface in the axial direction X of the mold when the elastic wall 46 described later is molded. Therefore, the base portion of the second liquid chamber 36B of the elastic wall 46 is formed in a state in which the convex portion 80 is embedded so as to cover the top surface 80C excluding the side surface 80B and the side surface 80A on the center side.

  Reference numeral 82 denotes an air vent hole penetrating in the axial direction X provided in the partition plates 48, 50. As shown in FIG. 5, a plurality of (here, four) are provided in the circumferential direction C of the partition plates 48, 50. ) Are distributed. The air vent hole 82 is provided so that the space 72 between the thin wall portion 66 and the partition plates 48 and 50 communicates with the first liquid chamber 36A or the second liquid chamber 36B. When the vibration isolator 10 is manufactured, the space 72 is evacuated and used to fill the space 72 with a liquid.

  The liquid-filled vibration isolator 10 can be manufactured as follows.

  First, when the partition body 40 is manufactured, the elastic wall 46 is vulcanized and formed on the orifice forming member 44. At the time of vulcanization molding, as shown in FIG. 7, the first mold 92 for molding the wall surface of the elastic wall 46 on the first liquid chamber 36A side and the second wall for forming the second liquid chamber 36B of the elastic wall 46 are formed. A rubber material is injected into a cavity 96 formed between the first die 92 and the second die 94 using a molding die 90 composed of the die 94, and the elastic wall 46 is vulcanized.

  At this time, in order to prevent rubber burrs from being generated at the base portion of the elastic wall 46 to the orifice forming member 44, the first mold 92 is disposed at the base portion of the elastic wall 46 on the first liquid chamber 36 </ b> A side. By pressing in the axial direction X against the one liquid chamber side end 44D, leakage of the rubber material from the cavity 96 is prevented.

  On the other hand, at the base portion of the elastic wall 46 on the second liquid chamber 36B side, the step surface 94A of the second mold 94 is axially oriented with respect to the straight surface side surface 80B of the convex portion 80 provided on the orifice forming member 44. Press against X. Thereby, the leakage of the rubber material from this portion is prevented, and the generation of rubber burrs can be suppressed. Here, if the elastic wall is bonded and fixed to the flat inner peripheral surface of the orifice forming member without providing such a convex portion as in the above-mentioned Patent Document 2, the first inner peripheral surface of the orifice forming member 44 is fixed. It is necessary to seal the rubber material by bringing the outer peripheral surface of the type 2 94 into close contact. However, due to the dimensional tolerance of the orifice forming member 44, it is difficult to seal the second die 94 with no gap, and rubber burrs are likely to occur. On the other hand, by using the side surface 80B of the convex portion 80 as the pressing surface in the axial direction X as in the present embodiment, rubber burrs can be prevented without such a problem, which is advantageous.

  After the elastic wall 46 is vulcanized and molded in this way, as shown in FIG. 4, the partition plates 48 and 50 are sandwiched from both the front and back sides of the elastic wall 46, and the connecting portion 60 is fixed by ultrasonic welding or the like. The partition body 40 shown in FIG. 2 is obtained.

  Next, using the partition body 40 and the vulcanized molded part of the first fixture 12, the cylindrical fitting 22, and the anti-vibration base 16 obtained by separately vulcanization molding, the cylindrical fitting in liquid. The partition body 40 is inserted into the interior of 22. In that case, since the air vent holes 82 are provided in the partition plates 48 and 50, the air can be extracted from the space 72 between the thin wall portion 66 and the partition plates 48 and 50 to fill the space 72 with the liquid. And the performance of the partition body 40 can be ensured.

  In this way, the partition body 40 is inserted, and after the diaphragm 38 is further covered, it is taken out from the liquid, covered with the bottom fitting 24, and the cylindrical fitting 22 and the bottom fitting 24 are caulked and fixed by the caulking portion 28. The liquid-filled vibration isolator 10 can be manufactured by sealing the stopper metal 30 in the upper end opening of the cylindrical metal member 22 and sealing the liquid.

  In the liquid-filled vibration isolator 10 of the present embodiment configured as described above, when a small amplitude vibration in a high frequency region is generated, the pair of partition plates 48 and 50 are reciprocated together to form the first. The vibration can be reduced by absorbing the liquid pressure in the liquid chamber 36A. In particular, in the present embodiment, the elastic wall 46 is partitioned and formed by the boundary line portion 64 into a thin wall portion 66 on the inner peripheral side and a thick wall portion 68 on the outer peripheral side, and the thin wall portion on the inner peripheral side. 66, the partition plates 48 and 50 are spaced apart from the partition plates 48 and 50 so as to ensure a predetermined space 72. Therefore, with respect to high-frequency fine amplitude vibration, the partition wall 48, 50 can be easily reciprocated in the axial direction X with the thin wall portion 66 as a low-rigidity portion, and the dynamic spring constant can be effectively reduced. .

  Further, since the boundary line portion 64 is formed thinner than the thin wall portion 66 by the circumferentially extending concave grooves 70 provided on both the front and back surfaces of the elastic wall 46, it is a partition against high frequency fine amplitude vibration. The plates 48 and 50 can be further reciprocated in the axial direction X, and the dynamic spring constant can be further effectively reduced. The concave groove 70 may be provided on only one of the front and back wall surfaces of the elastic wall 46, but it is more preferable to provide the groove 70 on both sides.

  On the other hand, when a large amplitude vibration in the low frequency region occurs, the displacement amount of the pair of partition plates 48 and 50 is regulated by the elastic wall 46, so that the liquid passes through the orifice 42 and the first liquid chamber 36A and the second liquid. The liquid can be circulated between the chambers 36B, and the vibration can be attenuated by the liquid flow effect. In particular, according to the present embodiment, the partition plates 48 and 50 are formed by the thick wall portions 68 on the outer peripheral side that are disposed to face the partition plates 48 and 50 through the gap 74 that gradually increases toward the radially outward Ko side. The reciprocating displacement can be effectively regulated.

  Further, the thick wall portion 68 contacts the partition plates 48 and 50 at the inner peripheral edge, and the gap 74 is formed between the thick wall portion 68 and the partition plates 48 and 50 on the outer peripheral side of the contact portion 76. Therefore, it is possible to prevent the generation of abnormal noise due to the collision between the thick wall portion 68 and the partition plates 48 and 50. Further, during large amplitude vibration, the contact area between the thick wall portion 68 and the partition plates 48 and 50 increases gradually and smoothly from the inner periphery side to the outer periphery side, and the partition plates 48 and 50 are displaced without causing abnormal noise. The regulatory effect can be enhanced. Furthermore, since the contact portion 76 is only the inner peripheral edge of the thick wall portion 68, the reciprocating displacement of the partition plates 48 and 50 by the thin wall portion 66 at the time of high frequency fine amplitude is not hindered.

  In the present embodiment, the raised portion 78 is provided on the outer peripheral portion 46A of the elastic wall 46, and the convex portion 80 is provided on the inner peripheral surface 44A of the orifice forming member 44 to which the outer peripheral portion 46A is bonded and fixed. Further, the rigidity of the outer peripheral portion 46A of the elastic wall 46 can be increased, and the displacement restriction effect of the partition plates 48 and 50 at the time of large amplitude vibration can be further enhanced. Further, since the raised portion 78 provided on the first liquid chamber 36A side is made of rubber, even if the vibration-isolating base 16 is excessively displaced downward and hits the raised portion 78, the vibration-isolating base 16 is damaged. Can be prevented.

  In the present embodiment, the distance between the wall surface 66A of the thin wall portion 66 and the first plate surfaces 48B and 50B of the partition plates 48 and 50 opposed to the wall surface 68A of the thick wall portion 68 and this wall surface 68A. Is set larger than the maximum dimension of the gap 74 between the second plate surfaces 48C and 50C of the partition plates 48 and 50 facing each other. Therefore, the range in which the partition plates 48 and 50 reciprocate is determined only by the gap 74 in the thick wall portion 68 on the outer peripheral side, and the thin wall portion 66 on the inner peripheral side not only has a small amplitude vibration but also has a large amplitude vibration. Also, it does not contact the partition plates 48 and 50. Therefore, it is possible to prevent abnormal noise due to the collision between the thin wall portion 66 and the partition plates 48 and 50 during large amplitude vibration.

  FIGS. 8 to 10 show the movement in the axial direction X of the liquid-filled vibration isolator 10 according to the above embodiment and the liquid-filled vibration isolator according to the conventional example having the partition shown in Patent Document 2. It is the graph which showed the characteristic. 8 and 9, the characteristic for large amplitude vibration (amplitude = ± 1.0 mm) in the low frequency region, and the characteristic for the small amplitude vibration (amplitude = ± 0.05 mm) in the high frequency region in FIG. Each is shown.

  As shown in FIGS. 8 and 9, in the embodiment, the dynamic spring constant and damping coefficient at the time of low-frequency large-amplitude vibration are higher than those of the conventional example, and the damping performance against large-amplitude vibration is excellent. . Further, as shown in FIG. 10, in the embodiment, the dynamic spring constant at the time of high-frequency fine amplitude vibration is low and the anti-vibration effect is excellent as compared with the conventional example.

  As described above, according to the present embodiment, the improvement in the damping performance with respect to the low frequency large amplitude vibration and the reduction of the dynamic spring constant with respect to the high frequency fine amplitude vibration can be achieved at a higher level than ever before.

  In the above embodiment, the concave groove 70 is continuously provided over the entire circumference of the elastic wall 46 in order to increase the effect of reducing the dynamic spring constant in the high frequency range, but is not necessarily continuous over the entire circumference. For example, you may provide intermittently in the circumferential direction. When interrupted, the interrupted portion of the concave groove 70 serves as a bridging portion that connects the thin wall portion 66 on the inner peripheral side of the boundary line portion 64 and the thick wall portion 68 on the outer peripheral side. In doing so, the rubber flow between the thin wall portion 66 and the thick wall portion 68 can be ensured, and the moldability can be improved.

  INDUSTRIAL APPLICABILITY The present invention can be used as various anti-vibration devices for automobiles, such as engine mounts for automobiles, in which vibration bodies and supports are coupled in an anti-vibration manner, and can also be used for various vehicles other than automobiles.

1 is a longitudinal sectional view of a liquid-filled vibration isolator according to an embodiment of the present invention. Longitudinal sectional view of the partition of the vibration isolator The principal part expanded sectional view of the partition Exploded longitudinal sectional view of the partition Top view of the partition Plan view of orifice forming member and elastic wall vulcanization molding constituting the partition Expanded cross-sectional view of the main part during molding of the vulcanized molded body Graph showing the relationship between frequency and dynamic spring constant during low-frequency and large-amplitude vibration Graph showing the relationship between frequency and damping coefficient during low-frequency large-amplitude vibration A graph showing the relationship between frequency and dynamic spring constant during high-frequency, small-amplitude vibration

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Liquid enclosure type vibration isolator 12 ... 1st fixture 14 ... 2nd fixture, 14A ... Peripheral wall part 16 ... Anti-vibration base | substrate 36 ... Liquid enclosure chamber 36A ... 1st liquid chamber, 36B ... 2nd liquid chamber 38 ... diaphragm 40 ... partition body 42 ... orifice 44 ... orifice forming member 44A ... inner peripheral surface 44D ... first liquid chamber side end 46 ... elastic wall 46A ... outer peripheral part 48 ... upper partition plate 48B ... first plate Surface, 48C ... Second plate surface 50 ... Lower partition plate, 50B ... First plate surface, 50C ... Second plate surface 60 ... Connection portion 64 ... Boundary line portion 66 ... Thin wall portion, 66A ... Wall surface 68 ... Thickness Meat wall part 68A ... wall surface 70 ... concave groove 74 ... gap 76 ... contact part 78 ... raised part 78A ... tip 80 ... convex part, 80B ... side surface 90 on the second liquid chamber side ... mold C ... circumferential direction Ko ... radially outward, Ki ... radially inward X ... axial direction

Claims (8)

A first fixture, a cylindrical second fixture, a vibration-proof base made of a rubber-like elastic material connecting the first fixture and the second fixture, and the second fixture attached to the second fixture. A diaphragm made of a rubber-like elastic film forming a liquid sealing chamber between the vibration isolating substrate and a partition that partitions the liquid sealing chamber into a first liquid chamber on the vibration isolating substrate side and a second liquid chamber on the diaphragm side And a liquid-filled vibration isolator comprising an orifice for communicating the first liquid chamber and the second liquid chamber,
The partition is
An annular orifice forming member provided inside the peripheral wall portion of the second fixture to form the orifice;
An elastic wall made of a rubber-like elastic material that plugs between the inner peripheral surfaces of the orifice forming member;
A pair of partition plates that are connected to each other via a connecting portion that penetrates the radial center of the elastic wall, and sandwiches the elastic wall in the axial direction of the elastic wall;
The elastic wall includes a boundary line portion extending in a circumferential direction, a thin wall portion having a wall surface spaced from and opposed to a plate surface of the partition plate on an inner peripheral side of the boundary line portion, and the boundary line On the outer peripheral side of the part, it is thickened in a stepped manner with respect to the thin wall part with the boundary line part as a boundary, and gradually widens radially outward from the plate surface of the partition plate A thick wall portion having a wall surface that forms a gap,
A liquid-filled vibration isolator characterized by that.   2. The liquid according to claim 1, wherein the boundary line portion is formed thinner than the thin wall portion by a groove extending in a circumferential direction provided on at least one wall surface of the elastic wall. Enclosed vibration isolator.   The distance between the wall surface of the thin wall portion and the plate surface of the partition plate facing the wall surface is greater than the maximum dimension of the gap between the wall surface of the thick wall portion and the plate surface of the partition plate facing the wall surface. The liquid-filled vibration isolator according to claim 1 or 2, wherein the liquid-filled vibration isolator is set to be larger.   The thick wall portion contacts the plate surface of the partition plate at the inner peripheral edge, and the wall surface of the thick wall portion is radially outward from the outer peripheral side of the contact portion with the plate surface of the partition plate. The liquid-filled vibration isolator according to any one of claims 1 to 3, wherein the gap gradually increases toward the side.   The wall surface of the thick wall portion and the plate surface of the partition plate facing the wall surface are each formed in an inclined surface shape that is located on the outer side in the axial direction of the elastic wall toward the radially outer side. The liquid-filled vibration isolator according to claim 1, wherein the thin wall portion is formed to have a constant thickness in a radial direction.   On the outer peripheral portion of the elastic wall that is bonded and fixed to the inner peripheral surface of the orifice forming member, the elastic wall protrudes outward in the axial direction with respect to the inclined wall surface of the thick wall portion. The liquid-filled type vibration damping device according to claim 5, further comprising a raised portion that increases the rigidity of the outer peripheral portion.   The convex part which protrudes radially inward and raises the rigidity of the outer peripheral part of the elastic wall is provided on the inner peripheral surface of the orifice forming member to which the outer peripheral part of the elastic wall is bonded and fixed. Liquid-filled vibration isolator. The outer peripheral portion of the elastic wall, which is bonded and fixed to the inner peripheral surface of the orifice forming member, has a wall surface on the first liquid chamber side of the elastic wall with respect to the inclined wall surface of the thick wall portion. A raised portion is provided on the first liquid chamber side, and the tip of the raised portion is located closer to the first liquid chamber side than the first liquid chamber side end of the orifice forming member;
On the inner peripheral surface of the orifice forming member to which the outer peripheral portion of the elastic wall is bonded and fixed, a convex portion protruding radially inward is provided at the base portion on the second liquid chamber side of the elastic wall, The side surface of the convex portion on the second liquid chamber side is formed on a straight surface perpendicular to the axial direction of the elastic wall, and the side surface of the convex portion on the second liquid chamber side is formed when the elastic wall is formed. The liquid-filled vibration isolator according to claim 5, which is a pressing surface in the axial direction against the mold.

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