JP5546415B2 - Liquid filled vibration isolator - Google Patents

Description

  The present invention relates to a liquid-filled vibration isolator that encloses a fluid, for example, used in a mount of an automobile engine or the like.

  Conventionally, as this type of liquid-filled vibration isolator, a rubber elastic body is interposed between the mounting bracket on the engine side and the support bracket on the vehicle body side, and the volume changes as the rubber elastic body deforms. In many cases, a liquid chamber is formed between the two members, the liquid chamber is divided into a pressure receiving chamber and an equilibrium chamber, and an orifice passage is provided to communicate the pressure receiving chamber and the equilibrium chamber. In such a liquid filled type vibration isolator, the liquid flows between the pressure receiving chamber and the equilibrium chamber via the orifice passage, so that the vibration from the engine is absorbed and damped.

  In addition, in such a liquid-filled vibration isolator, the support bracket itself is a bracket, in other words, a metal bracket in which a substantially cylindrical casing portion having a through hole and an attachment portion are integrally formed. There is known one in which a rubber elastic body is simultaneously molded in the casing portion. For example, in Patent Document 1, a substantially cylindrical second mounting bracket (corresponding to a bracket) formed so that a mounting portion through which a plurality of fixing holes are provided protrudes radially outward, A liquid-filled vibration isolator in which a main rubber elastic body is vulcanized and bonded is disclosed.

JP 2006-90531 A

  However, in the case where the rubber elastic body is simultaneously molded on the bracket as in the above-mentioned Patent Document 1, there are the following problems. That is, in the past, since the bracket was small, it was possible to mold a plurality of integrally vulcanized molded products (in which a rubber elastic body was simultaneously molded on the bracket) with a single mold, but today, Since a large bracket is required as the engine performance is improved, the number of integrally vulcanized molded products that can be molded with a single mold is limited, which increases the manufacturing cost of the liquid-filled vibration isolator. is there.

  Therefore, in order to reduce the manufacturing cost of the liquid-filled vibration isolator, a main spring portion in which a plurality of molds can be formed by one mold, for example, a mounting metal fitting and a metal pipe member (cylinder) connected by a rubber elastic body, It is conceivable to press fit into a through hole formed in the bracket.

  However, in such a press-fit structure, since the metal pipe member is fitted into the metal bracket, the main spring portion can be firmly fixed to the bracket, but the inner peripheral surface of the through hole of the bracket and the outer peripheral surface of the pipe member are Since the metal surfaces are in direct contact with each other, the sealing performance between them is very unstable, and there is a risk of fluid leakage.

  Therefore, by pressing the pipe member into the through hole formed in the bracket and pressing the end of the rubber elastic body vulcanized and bonded to the insertion tip of the pipe member against the orifice plate in which the orifice passage is formed, Although it is conceivable to perform sealing, in such a sealing structure, there is a possibility that one of the orifice ports of the orifice passage that opens facing the pressure receiving chamber is blocked.

  The present invention has been made in view of the above points, and the object of the present invention is to provide a liquid-filled vibration isolator having a bracket, even when the main spring portion is press-fitted into the through-hole of the bracket. An object of the present invention is to provide a technique for improving the sealing performance without blocking.

  In order to achieve the above object, in the present invention, a cylindrical body to which a rubber elastic body is vulcanized and bonded has a large-diameter cylindrical portion and a small-diameter cylindrical portion connected to the large-diameter cylindrical portion via a stepped portion. A small-diameter cylindrical portion is expanded so as to close a gap with the through-hole of the bracket by adopting a step structure and deforming the large-diameter cylindrical portion press-fitted into the through-hole of the bracket.

  Specifically, the first invention includes a metal cylinder, a mounting bracket that is disposed outside the cylinder and is substantially coaxial with the cylinder, and an outer peripheral surface of the mounting bracket. A rubber spring body interposed between the inner peripheral surface of the cylinder corresponding to this, a main spring portion having a through hole and a metal bracket attached to the engine side, An orifice plate fitted into the through-hole, and a diaphragm press-fitted into the through-hole so as to overlap the orifice plate, and press-fitting the cylindrical body into the through-hole from the opposite side of the diaphragm, The present invention is intended for a liquid-filled vibration isolator in which a volume-variable liquid chamber having the rubber elastic body, the inner peripheral surface of the through-hole, and the diaphragm as a part of a wall portion is formed.

  The cylindrical body includes a large-diameter cylindrical portion on one side in the cylindrical axis direction that is the mounting bracket side in the cylindrical axial direction, and a small-diameter cylindrical portion on the other side in the cylindrical axis direction connected to the large-diameter cylindrical portion via a stepped portion. The through-hole is opposed to the small-diameter cylindrical portion connected to the large-diameter portion on one side in the cylinder axis direction facing the large-diameter cylindrical portion, and the large-diameter portion via a stepped portion. A small-diameter portion on the other side in the cylinder axis direction, and the large-diameter portion has an inner diameter larger than an outer diameter of the small-diameter cylindrical portion and smaller than an outer diameter of the large-diameter cylindrical portion. On the other hand, the small-diameter portion has an inner diameter larger than the outer diameter of the small-diameter cylindrical portion, and the small-diameter cylindrical portion is narrowed by the large-diameter cylindrical portion being press-fitted into the large-diameter portion. Thus, the other end in the tube axis direction is closed so that the end on the other side in the tube axis direction of the small diameter tube portion closes the gap with the inner peripheral surface of the small diameter portion. And it is characterized in that the spread in the cylinder radially outward as it goes in.

  According to the first invention, since the rubber elastic body is interposed not between the mounting bracket and the bracket but between the mounting bracket and the cylindrical body, even if the bracket is large, the rubber elastic body can be molded once. A plurality of main spring portions can be formed.

  And since the large diameter part of the through-hole of a bracket is formed so that the internal diameter is larger than the outer diameter of the small diameter cylindrical part of a cylinder, and smaller than the outer diameter of a large diameter cylindrical part, When assembling, when the cylinder is inserted into the through-hole from one side in the cylinder axis direction to the other side in the cylinder axis direction, the small-diameter cylinder part passes through the large-diameter part of the through-hole, while the large-diameter cylinder part is It catches on the large diameter part.

  Then, when the large-diameter cylindrical portion of the cylindrical body is press-fitted into the large-diameter portion and deformed so that the large-diameter cylindrical portion is narrowed, the step portion having high rigidity in the cylindrical radial direction becomes a fulcrum, and the small-diameter cylindrical portion becomes As it goes to the other side in the cylinder axis direction, it expands and deforms so as to be inclined outward in the cylinder radial direction. In this way, since the metal cylinder is press-fitted into the metal bracket, the main spring portion can be firmly fixed to the bracket, and the small-diameter cylinder portion has an end on the other side in the axial direction within the small-diameter portion. Since it spreads outward in the cylinder radial direction so as to close the gap with the peripheral surface, the sealing performance between the bracket and the main spring portion can be improved.

  Unlike the case where sealing is performed by pressing the insertion tip of the casing against the orifice plate in which the orifice passage is formed, the insertion tip of the small-diameter cylindrical portion (the end on the other side in the cylinder axial direction) is Since the sealing is performed by expanding outward in the direction, it is possible to reliably prevent the orifice opening opened in the liquid chamber from being blocked.

  As described above, in the liquid-filled vibration isolator connected to the bracket, even when the main spring portion is press-fitted into the through hole of the bracket, the sealing performance can be improved without blocking the orifice port.

  According to a second invention, in the first invention, the outer peripheral surface of the small-diameter cylindrical portion is formed by inclining outward in the cylindrical radial direction toward the other side in the cylindrical axis direction. A seal rubber portion that is thicker toward the one side in the cylinder axis direction is formed so as to fill a space between the outer peripheral surface of the small diameter cylindrical portion and the inner peripheral surface of the small diameter portion. is there.

  According to the second invention, between the outer peripheral surface of the small-diameter cylindrical portion and the inner peripheral surface of the small-diameter portion, which is formed by inclining outward in the cylindrical radial direction toward the other side in the cylindrical axis direction. Since the space is filled with the seal rubber portion, the sealing performance between the bracket and the main spring portion can be further enhanced.

  A third invention is characterized in that, in the first or second invention, the inner peripheral surface of the large-diameter portion is inclined outward in the cylinder radial direction toward one side in the cylinder axis direction. is there.

  According to the third invention, since the inner peripheral surface of the large diameter portion is inclined outward in the cylinder radial direction toward the one side in the cylinder axis direction, the cylinder can be easily inserted into the through hole of the engine bracket. Such an inclined surface can serve as a guide to promote deformation of the cylindrical body.

  According to the liquid-filled vibration isolator according to the present invention, the rubber elastic body is interposed between the mounting bracket and the cylindrical body, not between the mounting bracket and the bracket. A plurality of main spring portions can be formed by one molding.

  Further, by pressing the cylinder into the large-diameter portion and deforming so that the large-diameter cylindrical portion is narrowed, the other-diameter end of the small-diameter cylindrical portion closes the gap with the inner peripheral surface of the small-diameter portion. Moreover, since it has spread outward in the cylinder radial direction, the sealing performance between the bracket and the main spring portion can be enhanced.

  Furthermore, since the sealing is performed by expanding the end portion on the other side in the cylinder axial direction of the small-diameter cylindrical portion toward the outside in the cylindrical radial direction, it is possible to surely prevent the orifice port opened in the liquid chamber from being blocked. it can.

It is a perspective view which shows the liquid enclosure type vibration isolator which concerns on embodiment of this invention. It is the II-II sectional view taken on the line of FIG. It is sectional drawing explaining typically the state which press-fits a main spring part to the through-hole of a bracket. It is a perspective view which shows the state which fixed the liquid enclosure type vibration isolator to the attachment bracket. It is a perspective view which shows a stopper rubber. It is a figure which shows stopper rubber, The figure (a) is the sectional view on the AA line of the figure (c), The figure (b) is a front view which shows an outer surface, The figure (c) ) Is a longitudinal sectional view, FIG. 6D is a rear view showing the inner surface, and FIG. 8E is a sectional view taken along line EE in FIG. It is a perspective view which shows a reinforcement member. It is a figure explaining the mode of a deformation | transformation of a stopper rubber, The figure (a) shows the conventional thing which simultaneously molded the stopper rubber in the bracket, The figure (b) shows the thing of this embodiment. It is sectional drawing explaining the deformation | transformation behavior of a cylinder. It is a figure which shows the hole wall of a through-hole typically. It is sectional drawing which shows typically the cylinder deform | transformed by press-fitting in a through-hole. It is sectional drawing which shows a seal | sticker part, The same figure (a) shows the state before press injection, and the same figure (b) shows the press-fitted state.

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

-Overall structure-
1 and 2 are diagrams showing a liquid-filled vibration isolator according to the present embodiment. As shown in FIGS. 1 and 2, this liquid-filled vibration isolator 1 is an engine having a through hole 13 that is attached to a power plant (engine side) (not shown) formed by combining an engine and a transmission. A bracket 3, a main spring portion 5 press-fitted into the through-hole 13 from the lower side (one side in the cylinder axis direction), an orifice plate 7 inserted into the through-hole 13 from the upper side (the other side in the cylinder axis direction), A diaphragm 9 press-fitted into the through-hole 13 from the upper side so as to overlap the orifice plate 7; a pair of stopper rubbers (stopper portions) 11 attached to the engine bracket 3 from the side (outside in the cylinder radial direction); It has.

  The main spring portion 5 includes an aluminum alloy inner plate (mounting bracket) 25 connected to the vehicle body side, an aluminum alloy outer pipe (tubular body) 15, and rubber vulcanized and bonded to connect them. As shown in FIG. 3, the outer pipe 15 is press-fitted into the through hole 13 and attached to the engine bracket 3. Thus, the liquid-filled vibration isolator 1 of the present embodiment has a power so that the cylinder axis direction of the outer pipe 15 faces the vertical direction and the pair of stopper rubbers 11 face each other in the vehicle front-rear direction. It can be attached to the plant and the car body.

  In this liquid-filled vibration isolator 1, a buffer solution such as ethylene glycol is contained in a cavity defined by the inner peripheral surface of the engine bracket 3, the main spring portion 5 (specifically, the rubber elastic body 35), and the diaphragm 9. The cavity forms a liquid chamber 31 for absorbing and mitigating vibrations of the power plant input to the rubber elastic body 35. Thus, the interior of the liquid chamber 31 is divided up and down by the orifice plate 7, and the lower side thereof is a pressure receiving chamber 31 a whose volume is enlarged or reduced as the rubber elastic body 35 is deformed. The upper side of the chamber 31 is an equilibrium chamber 31b that absorbs fluctuations in the volume in the pressure receiving chamber 31a by expanding or reducing the volume by deformation of the diaphragm 9.

  As shown in FIG. 4, the liquid-filled vibration isolator 1 has a substantially inverted U-shape that is attached to a vehicle body side frame (not shown) so as to straddle the liquid-filled vibration-proof device 1 in the front-rear direction. The power plant is elastically supported by being attached to the vehicle body via the mounting bracket 21. The mounting bracket 21 includes an upper beam portion 21a extending substantially horizontally in the front-rear direction above the liquid-filled vibration isolator 1, and a pair of front and rear leg portions 21b extending downward from both front and rear ends of the upper beam portion 21a. The lower part 21c extends substantially horizontally in the front-rear direction below the liquid-filled vibration isolator 1 so as to connect the leg parts 21b. The lower ends 21d are fastened on the side frames. Thus, the liquid filled type vibration isolator 1 is attached to the mounting bracket 21 by fixing the inner plate 25 of the main spring portion 5 to the lower beam portion 21c.

  As a result, in the liquid filled type vibration damping device 1, for example, when the automobile is stopped and the engine is in an idle operation state, low-frequency idle vibration caused by torque fluctuation or the like is absorbed by the rubber elastic body 35, and the vehicle body Vibration transmission to is suppressed. On the other hand, when a large driving reaction force (torque) acts, for example, during a sudden acceleration of an automobile, the power plant tends to swing back and forth, a pair of stopper rubbers 11 (more specifically, outer ridges 51a described later) By contacting the leg portion 21b of the mounting bracket 21, the front and rear deformation of the rubber elastic body 35 is restricted, and when the power plant tries to swing up and down, a pair of stopper rubbers 11 (protrusions described later in more detail). The upper and lower deformations of the rubber elastic body 35 are restricted by the portion 61b) coming into contact with the upper beam portion 21a of the mounting bracket 21.

-Engine bracket, etc.-
The engine bracket 3 is made of an aluminum alloy, and the engine bracket 3 is formed with a through-hole 13 extending in the vertical direction for inserting the main spring portion 5 and the like as described above. In other words, the engine bracket 3 has such a shape that an attachment portion 3b for attaching the casing portion 3a to the power plant is integrally formed with the substantially cylindrical casing portion 3a having the through hole 13. The casing portion 3a is formed with a pair of mounting pedestal portions 3c each projecting in the cylinder radial direction from the outer peripheral surface and having a flat outer surface. The pair of mounting base portions 3c are for mounting the pair of stopper rubbers 11, and are formed so as to face each other in the front-rear direction. Further, on the upper surface and the lower surface of each mounting base portion 3c, concave groove portions 3d and 3e are formed, respectively, into which convex ridge portions 61a and 71a of a stopper rubber 11 described later are fitted.

  The through hole 13 of the casing part 3a is connected to the upper through hole 23 into which the orifice plate 7 and the diaphragm 9 are inserted, and the lower side into which the main spring part 5 is inserted. And a through hole 43. Thus, the inner diameter of the upper through hole 23 is formed larger than the inner diameter of the lower through hole 43.

  The stepped portion 33 is provided with a disc-shaped orifice plate 7 from above, and further, a substantially hat-shaped rubber diaphragm 9 is provided so as to cover the entire orifice plate 7 from above. . A substantially cylindrical reinforcing plate 19 is embedded on the outer peripheral side of the diaphragm 9, and the diaphragm 9 is inserted into the engine bracket 3 by being press-fitted into the upper through hole 23 from above. It is fixed in the fitted state. Further, in the state in which the diaphragm 9 is fitted and fixed in this manner, the outer periphery of the orifice plate 7 is surrounded by the upper seal rubber portion 9 a extending downward from the reinforcing plate 19.

  An annular orifice passage (not shown) is formed in the orifice plate 7 so as to extend in the circumferential direction, and one end of the orifice passage opens toward the pressure receiving chamber 31a below the liquid chamber 31, The other end of the orifice passage opens toward the equilibrium chamber 31b above the liquid chamber 31. The buffer solutions in the pressure receiving chamber 31a and the equilibrium chamber 31b circulate through the orifice passage so that the low-frequency vibration acting on the pressure receiving chamber 31a from the rubber elastic body 35 is attenuated. .

-Stopper rubber-
As shown in FIGS. 2, 5, and 6, the stopper rubber 11 includes a substantially rectangular stopper main body 51 that is held on the outer side surface (mounting base portion 3 c) of the casing portion 3 a, and the stopper main body 51. It has a pair of upper and lower stopper mounting portions 61, 71 extending from the upper end portion and the lower end portion to the inside in the cylinder radial direction, and is formed in a substantially U-shaped cross section. Thus, the stopper rubber 11 having a substantially U-shaped cross section is attached to the casing portion 3a so that the casing portion 3a is sandwiched between the upper and lower pair of stopper attaching portions 61 and 71 in the cylinder axis direction.

  Four outer ridges (projections) 51a extending in a direction perpendicular to the vertical direction and the front-rear direction (hereinafter referred to as the left-right direction) so as to form three outer grooves 51b on the outer surface of the stopper main body 51. Are formed on the inner side surface of the stopper main body 51 so as to form three inner grooves 51d extending in the left-right direction.

  Further, the upper stopper mounting portion 61 is formed with four protrusions 61b extending in the left-right direction so as to form three grooves 61c on the upper surface thereof, while the concave groove portion 3d of the casing portion 3a is formed on the lower surface thereof. An upper ridge portion 61a having a substantially inverted trapezoidal cross section and extending in the left-right direction and projecting downward is formed. On the other hand, on the upper surface of the lower stopper mounting portion 71, a lower convex strip portion 71 a that fits in the concave groove portion 3 e of the casing portion 3 a and extends in the left-right direction and protrudes upward is formed. Yes.

  Further, as shown in FIGS. 2 and 7, the stopper rubber 11 has a substantially rectangular main body 12 a corresponding to the stopper main body 51, and an inner side in the cylinder radial direction from the upper end and lower end of the main body 12 a. A metal reinforcing member 12 having a substantially U-shaped cross section having extending portions 12c and 12d extending therein is embedded. A rectangular opening 12b is formed in the main body 12a of the reinforcing member 12, and the main body 12a of the reinforcing member 12 has a substantially rectangular frame shape.

  Then, the stopper rubber 11 is formed by fitting the upper and lower convex ridges 61a and 71a protruding from the upper and lower stopper attaching portions 61 and 71 into the concave grooves 3d and 3e of the casing 3a. Thus, the stopper body 51 is attached to the casing 3a, whereby the stopper main body 51 is held on the outer side surface (mounting base 3c) of the casing 3a.

  Here, since an inner protrusion 51c that protrudes inward in the cylinder radial direction is formed on the inner side surface of the stopper main body 51, when the stopper rubber 11 is attached to the casing part 3a, the inner protrusion 51c acts to push the outer surface of the mounting base 3c inward in the cylinder radial direction. For this reason, since the stopper main body 51 is pushed outward in the cylindrical radial direction by the reaction force from the mounting base 3c, the upper and lower ridges 61a and 71a fitted in the grooves 3d and 3e are It will be pulled outward in the cylinder radial direction. As a result, the upper and lower ridges 61a and 71a projecting from the upper and lower stopper mounting portions 61 and 71 and the inner ridges 51c projecting inward in the cylinder radial direction are as if the casing 3a. The stopper rubber 11 is firmly attached to the casing portion 3a because it acts so as to be sandwiched in the cylinder radial direction. Therefore, even when the separate stopper rubber 11 is attached to the outer side surface of the engine bracket 3, the noise generated by the separation and contact between the inner side surface of the stopper rubber 11 and the outer side surface of the engine bracket 3 is repeated. Can be suppressed.

  Further, since the inner protrusion 51c is formed so as to form the inner groove 51d on the inner surface of the stopper main body 51, the presence of the inner groove 51d causes the inner surface of the stopper main body 51 to be attached to the mounting base. The contact area with the outer surface of the part 3c will decrease. Thereby, even when the inner side surface of the stopper rubber 11 and the outer side surface of the mounting base portion 3c are rubbed, generation of abnormal noise can be suppressed.

  Furthermore, since the opening 12b is formed in the main body 12a of the reinforcing member 12 embedded in the stopper main body 51, the stopper main body 51 is located at a portion corresponding to the opening 12b in the stopper main body 51. The reinforcing member 12 is not divided into the inner side and the outer side in the cylinder radial direction, and an appropriate rubber volume is secured. In addition, since the stopper main body 51 is formed with outer and inner grooves 51b and 51d extending in the left-right direction, the stopper main body 51 is deformed by crushing (filling) these grooves 51b and 51d. It is easy. In other words, even if the outer and inner protrusions 51a and 51c are deformed so as to swell up and down in response to a load, the bulge is absorbed by the outer and inner grooves 51b and 51d, so that the stopper main body 51 is deformed. It is easy to do. Thus, since the stopper main body 51 has an appropriate rubber volume and is formed in a shape that is easily deformed, it exhibits a soft spring characteristic.

  Here, in the conventional one in which the rubber elastic body 135 and the stopper rubber 111 are simultaneously molded on the engine bracket 103, when the stopper rubber 111 is deformed and the groove is filled, as shown by the white arrow in FIG. Since the stopper rubber 111 is deformed so as to escape in the vertical direction, the elastically supported power plant may be displaced too much. On the other hand, in the stopper rubber 11 according to the present embodiment, when the outer and inner protrusions 51a and 51c are deformed and the outer and inner grooves 51b and 51d are filled, the portion corresponding to the opening 12b in the stopper main body 51. However, since the deformation is suppressed by the main body portion 12a of the frame-shaped reinforcing member 12, as shown by the white arrow in FIG. 51 will exhibit a hard spring characteristic.

  As described above, it is possible to realize the stopper rubber 11 having a two-stage characteristic including a region that is greatly deformed and absorbs an impact when a load is input and a region that is not significantly deformed even when a load is input and suppresses displacement. It becomes possible.

−Main spring part−
The inner plate 25 of the main spring portion 5 has a substantially rectangular bottom plate portion 55b and a side plate portion 55a extending downward from one side edge in the longitudinal direction of the bottom plate portion 55b. Part 55 and a substantially top-like inner pipe part 45 in which the bottom plate part 55b of the mounting plate part 55 is bulged upward. The inner pipe portion 45 is arranged substantially coaxially with the outer pipe 15 so that the upper end portion thereof is positioned at the approximate center of the lower end opening portion of the outer pipe 15 of the main spring portion 5, and corresponds to the outer peripheral surface thereof. A rubber elastic body 35 is interposed between the inner peripheral surface of the outer pipe 15 to be performed. On the other hand, the mounting plate portion 55 bends the side beam portion on the other side in the longitudinal direction of the bottom plate portion 55b so as to sandwich the lower beam portion 21c of the mounting bracket 21 from the left and right together with the side plate portion 55a and caulk the lower surface thereof. Further, the lower beam portion 21c is attached from above.

  A mortar-shaped concave portion 35 a is formed on the lower inner peripheral side of the rubber elastic body 35, and the peripheral surface of the concave portion 35 a is bonded to the outer peripheral surface of the inner pipe portion 45. The rubber elastic body 35 has a substantially truncated cone shape extending radially outward from the entire circumference of the inner pipe portion 45 and extending obliquely upward. The outer peripheral surface of the upper portion of the rubber elastic body 35 is the outer pipe 15. Bonded to the inner peripheral surface. Thus, the upper part of the rubber elastic body 35 that is bonded and fixed to the inner periphery of the outer pipe 15 has a relatively thick cylindrical shape that opens upward, and its upper end 35b is the outer pipe 15's. The upper end portion 15e is covered. Then, by fitting the outer pipe 15 into the lower through-hole 43, the liquid filled type vibration isolator 1 has the rubber elastic body 35 and the inner peripheral surface of the lower through-hole 43 as a part of the wall portion. A variable volume liquid chamber 31 is formed.

  By the way, in the structure in which the metal outer pipe 15 is press-fitted into the through hole of the metal engine bracket 3, the metal surfaces are in direct contact with each other. There is a risk.

  Therefore, in the liquid-filled vibration isolator 1 of the present embodiment, the outer pipe 15 is not in a cylindrical shape with a constant diameter, but is on the inner plate 25 side in the cylinder axis direction in order to improve the sealing performance with the engine bracket 3. A lower large-diameter cylindrical portion 15c and an upper small-diameter cylindrical portion 15a having an outer diameter smaller than that of the large-diameter cylindrical portion 15c and connected to the large-diameter cylindrical portion 15c through a step portion 15b. It has a step structure. The reason why such a two-stage structure is adopted is as follows.

  That is, in the two-stage structure in which the small-diameter cylindrical portion 15a is connected to the large-diameter cylindrical portion 15c through the step portion 15b, as shown in FIG. 9, when the large-diameter cylindrical portion 15c is tightened and deformed in the cylindrical radial direction, The inner peripheral surface of the lower through-hole 43 of the lower side of the engine bracket 3 by utilizing the property that the step portion 15b having high rigidity in the cylinder radial direction becomes a fulcrum and the small diameter cylindrical portion 15a expands upward and outward in the cylindrical radial direction. This is to fill a gap between the outer peripheral surface of the outer pipe 15 and the outer pipe 15. In addition, the code | symbol 15d in a figure is a flange part formed by bend | folding the lower end part of the large diameter cylinder part 15c to a cylinder radial direction outer side.

  Thus, the lower through-hole 43 of the engine bracket 3 is formed so as to correspond to the outer pipe 15 having the two-stage structure, as shown in FIG. 43c and an upper small-diameter portion 43a that is continuous with the large-diameter portion 43c through a stepped portion 43b and faces the small-diameter cylindrical portion 15a. The large-diameter portion 43c is formed so that its inner diameter is larger than the outer diameter of the small-diameter cylindrical portion 15a and smaller than the outer diameter of the large-diameter cylindrical portion 15c. It is formed larger than the outer diameter of the portion 15a.

  The large-diameter portion 43c is inclined 1.5 ° so as to incline toward the outside in the cylinder radial direction toward the lower side in order to ensure the draft of the mold when the engine bracket 3 is molded. As described above, since the large-diameter portion 43c is inclined, in the liquid-filled vibration isolator 1 of this embodiment, the large-diameter cylindrical portion 15c can be easily inserted into the large-diameter portion 43c, and the large-diameter portion 43c There is also an advantage that the portion 43c serves as a guide that promotes deformation of the large-diameter cylindrical portion 15c.

  The small-diameter cylindrical portion 15a of the outer pipe 15 is inserted into the lower through-hole 43 of the engine bracket 3 formed in this way from below, and the large-diameter cylindrical portion 15c until the flange portion 15d hits the lower end of the casing portion 3a. As shown in FIG. 11, the large-diameter cylindrical portion 15c is press-fitted into the large-diameter portion 43c and is narrowed, so that the small-diameter cylindrical portion 15a has an upper end portion 15e that is in contact with the inner peripheral surface of the small-diameter portion 43a. As it goes upward, it expands outward in the cylinder radial direction so as to close the gap. Thereby, in the liquid-filled vibration isolator 1 of the present embodiment, the upper end portion 35b of the rubber elastic body 35 (not shown in FIG. 11) is formed so as to wind up the upper end portion 15e of the outer pipe 15. However, the sealability between the engine bracket 3 and the main spring portion 5 is enhanced by being pressed against the inner peripheral surface of the small diameter portion 43a.

  Here, since the small diameter cylindrical portion 15a is deformed so as to expand outward as it goes upward, as shown in FIG. 11, between the outer peripheral surface of the small diameter cylindrical portion 15a and the inner peripheral surface of the small diameter portion 43a. Thus, a space 41 having a substantially triangular cross section is formed. Therefore, in the liquid-filled vibration isolator 1 of the present embodiment, in order to further improve the sealing performance, as shown in FIG. 12 (a), the upper and lower portions projecting outward in the cylinder radial direction on the outer peripheral surface of the small diameter cylinder portion 15a. A lower seal rubber portion 35 c provided with a three-stage seal lip 35 d and thicker toward the bottom is formed integrally with the rubber elastic body 35.

  Thus, by forming the lower seal rubber portion 35c that becomes thicker as it goes downward, the large-diameter cylindrical portion 15c is press-fitted into the large-diameter portion 43c, and as the small-diameter cylindrical portion 15a goes upward, the cylindrical radial direction When expanded outward, as shown in FIG. 12B, the lower seal rubber portion 35c creates a space 41 having a substantially triangular cross section between the outer peripheral surface of the small diameter cylindrical portion 15a and the inner peripheral surface of the small diameter portion 43a. In addition, since the seal lip 35d is pressed against the inner peripheral surface of the small diameter portion 43a, the sealing performance between the engine bracket 3 and the main spring portion 5 is further enhanced.

  As described above, in the liquid-filled vibration isolator 1 of the present embodiment, the seal by expanding outward in the cylinder radial direction as the small-diameter cylindrical portion 15a of the outer pipe 15 goes upward, and the lower seal rubber portion 35c have a small diameter. By providing a two-stage seal called a seal by filling a space 41 having a substantially triangular cross section between the outer peripheral surface of the cylindrical portion 15a and the inner peripheral surface of the small diameter portion 43a, the through hole 13 of the engine bracket 3 is provided with an outer It is possible to enhance the sealing performance between the both 3 and 15 while having a structure in which the pipe 15 is press-fitted.

  Further, the sealing is not performed by pressing the upper end portion 15e of the rubber elastic body 35 against the lower surface of the orifice plate 7, but by pressing the upper end portion 15e of the rubber elastic body 35 against the inner peripheral surface of the small diameter portion 43a. Therefore, by pressing the outer pipe 15, it is possible to reliably avoid closing one end of the orifice passage 7 a that opens toward the pressure receiving chamber 31 a below the liquid chamber 31. .

-Effect-
According to the present embodiment, since the main spring portion 5 and the stopper rubber 11 and the engine bracket 3 are separated, the plurality of main spring portions 5 and the stopper rubber 11 can be formed by one molding.

  Further, since the engine bracket 3 made of aluminum alloy, the outer pipe 15 and the inner plate 25 are used, the liquid-filled vibration isolator 1 can be reduced in weight.

  Further, since the metal outer pipe 15 is press-fitted into the metal engine bracket 3, the main spring portion 5 can be firmly fixed to the engine bracket 3.

  Further, when the large-diameter cylindrical portion 15c of the outer pipe 15 is press-fitted into the large-diameter portion 43c and deformed so that the large-diameter cylindrical portion 15c is narrowed, the small-diameter cylindrical portion 15a has an upper end 15e whose inner peripheral surface is the small-diameter portion 43a So as to close the gap between the engine bracket 3 and the main spring portion 5, the sealing performance between the engine bracket 3 and the main spring portion 5 can be improved.

  Furthermore, a space 41 between the outer peripheral surface of the small-diameter cylindrical portion 15a and the inner peripheral surface of the small-diameter portion 43a formed by inclining outward in the cylindrical radial direction as the outer peripheral surface of the small-diameter cylindrical portion 15a goes upward. Since it is filled with the lower seal rubber portion 35c, the sealing performance between the engine bracket 3 and the main spring portion 5 can be further enhanced.

  Further, since the inner peripheral surface of the large-diameter portion 43c is inclined outward in the cylinder radial direction as it goes downward, the outer pipe 15 can be easily inserted into the lower through hole 43 of the engine bracket 3, and the inclined surface As a guide, deformation of the outer pipe 15 can be promoted.

(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 above embodiment, the cylinder axis direction of the outer pipe 15 is directed in the vertical direction. However, the present invention is not limited to this, and the cylinder axis direction of the outer pipe 15 may be inclined according to the application, and the diaphragm 9 It may be located on the side.

  Moreover, in the said embodiment, although the hole wall of the large diameter part 43c of the lower side through-hole 43 of the engine bracket 3 was inclined 1.5 degree, it is not restricted to this, For example, by giving a cutting in a post process, The wall may not be inclined, and the hole wall may be inclined more than 1.5 °. In addition, a preferable inclination | tilt angle is the range of 0-10 degrees.

  Furthermore, in the said embodiment, although the upper end part 35b of the rubber elastic body 35 formed so that the upper end part 15e of the outer pipe 15 may be wound was pressed on the internal peripheral surface of the small diameter part 43a, it is not restricted to this. For example, the upper end portion 15e of the outer pipe 15 is not wound by the upper end portion 35b of the rubber elastic body 35, and the inner diameter of the small diameter portion 43a and the outer diameter of the small diameter cylindrical portion 15a are adjusted. You may make it press 15e directly on the internal peripheral surface of the small diameter part 43a.

  Moreover, in the said embodiment, although the outer pipe 15 made from an aluminum alloy was used, it is not restricted to this, For example, you may use an iron outer pipe.

  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 that encloses a fluid, which is used in mounts for automobile engines and the like.

1 Liquid-filled vibration isolator 3 Engine bracket (bracket)
5 Main spring part 13 Through hole 15 Outer pipe (cylinder)
15a Small diameter cylindrical portion 15b Stepped portion 15c Large diameter cylindrical portion 15e Upper end (end on the other side in the cylinder axis direction)
25 Inner plate (mounting bracket)
31 Liquid chamber 35 Rubber elastic body 41 Space 43 Lower through hole (through hole)
43c Large diameter portion 43b Step portion 43a Small diameter portion 35c Lower seal rubber portion (seal rubber portion)

Claims (3)

A metal cylinder, a mounting bracket mounted on the vehicle body side, which is arranged outside the cylinder and substantially coaxially with the cylinder, an outer peripheral surface of the mounting bracket, and an inner peripheral surface of the corresponding cylindrical body A main spring portion having a rubber elastic body interposed therebetween,
A metal bracket attached to the engine side with a through hole,
An orifice plate fitted into the through hole;
A diaphragm press-fitted into the through hole so as to overlap the orifice plate,
By pressing the cylindrical body into the through hole from the opposite side of the diaphragm, a variable volume liquid chamber is formed with the rubber elastic body, the inner peripheral surface of the through hole, and the diaphragm as a part of the wall portion. A liquid-filled vibration isolator,
The cylindrical body includes a large-diameter cylindrical portion on one side in the cylindrical axial direction that is the mounting bracket side in the cylindrical axial direction, and a small-diameter cylindrical portion on the other side in the cylindrical axial direction that is connected to the large-diameter cylindrical portion via a stepped portion. Have
The through-hole has a large-diameter portion on one side in the cylinder axial direction facing the large-diameter cylindrical portion, and a small-diameter on the other side in the cylindrical axis facing the small-diameter cylindrical portion, which is connected to the large-diameter portion via a stepped portion. A portion, and
The large diameter portion has an inner diameter larger than an outer diameter of the small diameter cylindrical portion and smaller than an outer diameter of the large diameter cylindrical portion, while the small diameter portion has an inner diameter outside the small diameter cylindrical portion. Formed larger than the diameter,
In the small diameter cylindrical portion, the large diameter cylindrical portion is press-fitted into the large diameter portion and is narrowed so that the end on the other side in the cylinder axial direction of the small diameter cylindrical portion forms a gap with the inner peripheral surface of the small diameter portion. A liquid-filled vibration isolator that expands outward in the cylinder radial direction toward the other side in the cylinder axis direction so as to be closed. The liquid-filled vibration isolator according to claim 1,
On the outer peripheral surface of the small-diameter cylindrical portion, the outer peripheral surface of the small-diameter cylindrical portion and the inner periphery of the small-diameter portion formed by inclining outward in the cylindrical radial direction toward the other side in the cylindrical axis direction. A liquid-filled vibration damping device, wherein a seal rubber portion that is thicker toward one side in the cylinder axis direction is formed so as to fill a space between the surface and the surface. The liquid-filled vibration isolator according to claim 1 or 2,
The liquid-filled vibration damping device, wherein an inner peripheral surface of the large-diameter portion is inclined outward in the cylinder radial direction toward one side in the cylinder axis direction.

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