JP2007270891A - Vibration isolation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration isolation device of a new structure capable of providing excellent vibration isolation effect by adopting a synthetic resin housing member. <P>SOLUTION: The housing member 12 is formed out of synthetic resin material and a straight part 36 extending with constant inner diameter dimension and a bottom part side taper part 38 of which diameter gets smaller toward a bottom wall. An abutment part 60 and a bottom part side extension part 56 is formed on an independent member 14 stored in the housing member 12. A gap dimension with the abutment part 60 in the straight part 36 is set smaller than the bottom part side extension part 56 in the bottom side part taper part 38 to make the abutment part 60 abut on the straight part 36 and to avoid the bottom part side extension part 56 from striking the bottom part side taper part 38. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vibration isolator that reduces vibrations in various vibration members to be vibration-isolated, and suppresses vibrations in, for example, automobile suspension members, subframes, body panels, engine units, mount brackets, exhaust system members, and the like. The present invention relates to a vibration isolator having a novel structure that can be advantageously employed in a vibration damping device for automobiles.

  Conventionally, as a technique for reducing vibrations that are problematic in various vibration members, (1) a mass damper in which a mass material is fixed to the vibration member, and (2) a mass material is connected to and supported by the vibration member via a spring material. There are known dynamic dampers and (3) vibration damping materials in which a sheet-like elastic material is attached to the surface of a vibration member. However, the above (1) mass damper and (2) dynamic damper both have a problem that a large mass material mass is required and a frequency range where an effective damping effect is exhibited is narrow. . In addition, the (3) vibration damping material has a problem that a large sticking area is required and the weight increases. Furthermore, the above (2) dynamic damper and (3) damping material have a problem that it is difficult to stably obtain the desired damping effect because the temperature dependence of the damping effect is high. .

  Therefore, the applicant of the present invention previously described in Patent Document 1 (International Publication WO00 / 14429) with a gap with respect to the hollow housing member that is provided by being integrally formed with the vibration member or being fixed thereafter. In addition, a vibration isolator with a structure in which an independent mass member is accommodated and displaceable without adhesion is proposed. In this vibration isolator, when the vibration is input, the independent mass member repeatedly jumps and displaces with respect to the housing member, and the vibration damping effect is exhibited by the impact of the independent mass member against the housing member. In particular, in the vibration isolator having such a structure, it is lighter and can obtain an effective vibration damping effect against vibrations over a wide frequency range as compared to the mass damper, the dynamic damper, or the vibration damping material as described above. It can be done.

  By the way, according to the further research of the present inventor, a structure in which the inner peripheral surface of the housing member has a circular cross section and a circular rod-shaped independent mass member having a circular outer peripheral surface that is slightly smaller than the inner peripheral surface is accommodated therein. It turned out to be particularly preferred. By adopting such a striking surface having a circular cross section, a more excellent vibration damping effect can be exhibited stably and over a long period of time. Although the technical reason has not yet been clarified sufficiently, the contact surface has a circular cross section, so that when the independent mass member and the housing member strike, the displacement direction of the independent mass member Contact with the inclined contact surface and friction are generated to improve the damping effect, the independent mass member rotates around the central axis in the housing, and the rotation of the independent mass member further causes contact with the housing member. It is presumed that the reason is that the contact part changes appropriately on the circumference.

  Further, according to further research by the present inventor, by adopting a synthetic resin material instead of a metal material as a housing member, it is possible to reduce the manufacturing cost and simplify the manufacturing process while ensuring a good vibration isolation effect. It became clear that can be planned.

  By covering and configuring the housing member with a synthetic resin material, an increase in the vibration mass can be avoided by suppressing the mass of the housing member, and handling and conveyance are facilitated. In addition, since the housing member made of synthetic resin can be expected to have a certain degree of elastic deformation as compared with metal, it can also be expected to improve the damping effect when hitting the independent mass member, and the metal independent mass member In some cases, it is not necessary to provide a cushioning material such as a rubber layer on the contact surface. Further, the housing member made of synthetic resin can be mass-produced with relatively simple equipment as compared with processing of a metal material. Furthermore, the housing made of synthetic resin has an advantage that the operation is easy because it can employ adhesion or welding when attaching to the bracket or the member to be damped as compared with the metal.

  However, when a synthetic resin housing member is employed, there is a significant problem with respect to the size of the gap provided between the inner peripheral surface of the housing member and the outer peripheral surface of the independent mass member.

  That is, in the anti-vibration device of the hit type in which the anti-vibration effect is obtained by hitting the housing member of the independent mass member as described above, in order to effectively obtain the anti-vibration effect, the outer peripheral surface of the independent mass member and It is important to set the gap between the housing member and the inner peripheral surface with a high precision with a minute value of about 1 mm or less. Therefore, for example, forming a cylindrical housing member by abutting a half-divided saddle-shaped two-part structure is extremely difficult to ensure sufficient dimensional accuracy at the abutting portion and is difficult to employ. In addition, it is necessary to integrally form a housing member having a hollow circular inner peripheral surface including a cylindrical peripheral wall that is integrally structured in the circumferential direction by injection molding or the like. Then, when manufacturing the housing member of the hollow circular inner peripheral surface by a resin material by injection molding or the like, the hollow circular inner peripheral surface is used in order to remove the molded product by pulling the molding die in the axial direction in the mold opening process. Therefore, there is a problem that it is difficult to set the gap between the outer peripheral surface of the independent mass member to be constant over the entire length in the axial direction. is there.

  In order to cope with this problem, the outer peripheral surface of the independent mass member and the housing are formed by attaching the same taper as the punching tape applied to the inner peripheral surface of the housing member to the outer peripheral surface of the independent mass member. It is also conceivable to make the gap between the inner peripheral surfaces of the members constant over the entire length in the axial direction.

  However, when such an axial taper is provided, the contact surface of the independent mass member with respect to the housing member is inclined with respect to the jumping direction of the independent mass member serving as the vibration input direction. Due to the inclination of the striking surface in the axial direction, it is inevitable that a component force in the axial direction is generated when the independent mass member jumps or strikes. As a result, the jumping of the independent mass member becomes unstable, and there is a problem that the vibration damping effect exerted by hitting is reduced.

International Publication WO00 / 14429

  Here, the present invention has been made in the background as described above, and has a novel structure capable of obtaining an excellent vibration damping effect by employing a housing member made of synthetic resin. The purpose is to provide

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

  That is, the feature of the present invention is that the independent mass member is accommodated in the cylindrical housing member in a non-adhering manner, and the independent mass member jumps against the housing member and repeatedly strikes when the vibration is input. In the vibration isolator, the housing member has a bottomed cylindrical shape having a bottom wall at one end in the axial direction, and is formed of a synthetic resin material integrally molded. A straight portion extending at a constant inner diameter in the central portion in the direction, and a bottom side taper portion gradually decreasing in diameter toward the bottom wall on the bottom side of the straight portion, and the other end in the axial direction of the housing member On the other hand, a mass accommodation space is formed by covering the opening of the part with a lid member, while the independent mass member accommodated in the mass accommodation space is An abutting portion having a solid circular rod shape extending with a constant outer diameter smaller than an inner diameter of the straight portion of the housing member, and being accommodated in the straight portion of the housing member; and the housing A bottom-side extending portion that extends in the axial direction from the corresponding contact portion in an outer peripheral surface shape smaller than the bottom-side tapered portion of the member and is accommodated in the bottom-side tapered portion of the housing member. And the gap dimension between the outer peripheral surface of the corresponding contact portion of the independent mass member and the inner peripheral surface of the straight portion of the housing member is such that the outer peripheral surface of the bottom side extending portion of the independent mass member and the housing When the independent mass member jumps with respect to the housing member due to vibration input, it is made smaller than the gap between the bottom side taper portion and the inner peripheral surface of the member. Part is the stray Striking against parts, in that so that striking of the bottom portion side tapered portion of the bottom portion side extending portion is avoided.

  In the vibration isolator having a structure according to the present invention, the housing member is integrally or separately formed with respect to the vibration member to be controlled. When the vibration of the vibration member is exerted on the housing member in such a mounted state, the independent mass member jumps and is displaced in the accommodation space formed inside the cylindrical housing member, and the independent mass member is displaced with respect to the housing member. Therefore, an effective vibration damping effect is exerted on the vibration member based on a collision action or a shearing action when the independent mass member strikes the contact member.

  Further, in the vibration isolator having a structure according to the present invention, the housing member is made of a synthetic resin material, so that it is lightweight and suitable for mass production and easily manufactured at low cost. It is possible. In addition, the housing member formed of a synthetic resin material exhibits a sound reduction effect as compared with a housing member formed of a metal material when hitting an independent mass member, and also has a damping effect when deformed. It can be used to improve the vibration control effect.

  Further, since the housing member is formed of a synthetic resin material, when the independent mass member strikes, the urging force in the jumping direction based on the elasticity of the housing member is applied to the independent mass member in the antigravity direction. It will be. Thereby, for example, even when an acceleration vibration of 1 G or less is input, an effective mass damping effect can be obtained by causing the independent mass member to jump using the elasticity of the housing member and hit the housing member. It becomes possible.

  Further, in the vibration isolator having the structure according to the present invention, the housing member is made of a synthetic resin material, so that the oxidative corrosion (rust) of the housing member is made as compared with the case where the housing member is made of metal. Can be prevented, and durability and damping performance can be stabilized.

  Here, in particular, in the vibration isolator according to the present invention, the housing member has a bottomed cylindrical shape, and on the inner peripheral surface, a straight portion is formed in the axial center portion, and on the bottom side thereof. A bottom side taper portion is formed. By having such a specific inner peripheral surface shape, the bottom side taper portion functions as a punching taper at the time of molding, so that it can be removed in the axial direction without problems and can be manufactured satisfactorily. In addition, in the central straight part, the independent mass member that jumped at the time of vibration input hits in the direction perpendicular to the axis, and generation of component forces in the axial direction etc. is suppressed at the time of hitting, and stable jumping and hitting are achieved. As a result, the intended damping effect can be effectively exhibited.

  In the present invention, the housing member can be formed integrally with the vibration member by constituting a part or the whole of the wall portion using the vibration member. The formed separate housing member can be integrally provided by being fixed to the vibration member by welding, bolts or the like.

  Further, in the present invention configured as described above, the axial length of the bottom side extension portion of the independent mass member is larger than the axial length of the bottom side taper portion of the housing member. A configuration in which is increased is preferably employed.

  In this way, by setting the bottom-side extended portion of the independent mass member to be longer in the axial direction than the bottom-side tapered portion of the housing member, when the independent mass member jumps and displaces within the housing space of the housing member, the independent mass A configuration that easily prevents the bottom-side extending portion of the member from hitting the housing member can be realized. As a result, the contact of the independent mass member with the straight portion of the housing member is stably generated, and the intended vibration damping effect can be more effectively and stably exhibited.

  Further, in the vibration isolator according to the present invention, the outer peripheral surface of the bottom side extension portion of the independent mass member has a tapered taper shape that gradually decreases in diameter toward the tip in the axial direction. A configuration in which the taper angle of the outer peripheral surface of the protruding portion is made larger than the taper angle of the bottom side taper portion of the housing member is suitably employed.

  In this way, by reducing the diameter of the extending portion on the bottom side of the independent mass member as a taper angle larger than the taper portion on the bottom side of the housing member, similarly to the case where the axial length is relatively adjusted and set as described above. In addition, it is possible to realize a configuration that easily prevents the bottom-side extending portion of the independent mass member from hitting the housing member.

  It should be noted that the relative setting of the axial length and the relative setting of the taper angle as described above between both the bottom-side extension portion of the independent mass member and the bottom-side taper portion of the housing member are the same. It can also be used in combination.

  Further, in the vibration isolator according to the present invention, the housing member is formed with an opening side taper portion gradually increasing in diameter toward the opening portion on the opening portion side of the straight portion, The clearance dimension between the inner peripheral surface of the opening side taper portion and the outer peripheral surface of the independent mass member is such that the outer peripheral surface of the contact portion of the independent mass member and the inner peripheral surface of the straight portion of the housing member A configuration in which the size of the gap between the independent mass member and the opening side tapered portion is avoided is preferably employed.

  By providing such an opening-side taper portion on the housing member, an axial direction for demolding after molding while securing a contact area of the independent mass member in the straight portion at the axial central portion of the housing member It becomes possible to give a draft taper more advantageously. Therefore, the housing member can be more easily manufactured while sufficiently securing the vibration damping effect based on the contact of the independent mass member with the housing member.

  Further, in the vibration isolator having the opening side taper portion provided in the housing member, the independent mass member extends from the contact portion in the axial direction opposite to the bottom side extension portion, and the housing. Also in the portion of the member that is accommodated in the opening-side taper portion, a configuration that extends in the axial direction with the same constant outer diameter as that of the corresponding contact portion is suitably combined and employed.

  That is, the independent mass member adopts a simple shape that extends in the axial direction with a constant outer diameter as it is from the straight portion of the central portion in the axial direction, and against the opening side taper portion of the housing member when the independent mass member jumps. By avoiding hitting, it is possible to easily prevent instability of the displacement of the independent mass member resulting from hitting the opening side tapered portion.

  In the vibration isolator according to the present invention, the independent mass member is formed of a solid metal material, and the outer peripheral surface of the independent mass member is an inner periphery of the housing member formed of a synthetic resin material. A configuration that directly hits the surface is preferably employed.

  According to such a configuration, it is possible to advantageously secure a mass mass due to a metal having a large specific gravity in the independent mass member, and to obtain an effective vibration damping effect by utilizing a damping action by the synthetic resin material forming the housing member. Can be obtained. In particular, a thin rubber layer is formed on at least one of the inner peripheral surface of the housing member and the outer peripheral surface of the independent mass member, so that the impact sound is reduced or attenuated when hitting. Although it is possible to further improve the vibration damping effect by the above, it is possible to form the rubber layer by directly hitting the independent mass member against the housing member without forming the rubber layer as in this configuration. It is possible to obtain a sufficient damping effect while avoiding problems such as complicated manufacturing and a decrease in accuracy of the gap size at the contact portion between the housing member and the independent mass member.

  Further, in the vibration isolator according to the present invention, the lid member is formed with an inward protrusion that enters inward in the axial direction from the axially open end of the housing member, and the independent protrusion A configuration in which the axially moving end of the mass member is limited is preferably employed.

  By adopting such a lid member provided with an inward projection, the inward projection protrudes inward in the axial direction from the abutting portion of the housing member and the lid member, and the independent mass member extends in the axial direction. The moving end can be limited by the inward protrusion. As a result, even when there is a step or the like at the abutting portion of the housing member and the lid member, it is avoided that the independent mass member hits the portion, and the independent mass member is caused by hitting such a step or the like. There is no such thing that the hit state becomes unstable.

As described above, in the vibration isolator constructed according to the present invention, the synthetic resin housing member is realized with good manufacturing workability, and such a synthetic resin housing member is adopted. Therefore, it is possible to provide a large amount of vibration isolator capable of exhibiting an excellent vibration damping effect at a low cost.

  First, the vibration isolator 10 as one Embodiment of this invention is shown by FIGS. 1-3. The vibration isolator 10 has a structure in which an independent mass 14 as an independent mass member is accommodated and disposed in a non-adhesive manner with respect to a hollow case housing 12 as a housing member. The case housing 12 is fixed and attached to a vibration member (not shown) to be a vibration isolation target. In addition, when the vibration of the vibration member is applied to the case housing 12 under such a mounted state, the independent mass 14 jumps in the case housing 12 and repeatedly strikes the inner surface of the case housing 12, thereby exhibiting a vibration damping effect. It has come to be.

  More specifically, the case housing 12 includes a housing body 16 and a lid 18 as a lid member, as shown in FIG. The housing body 16 has a bottomed cylindrical shape with a circular cross section as a whole. The shape of the outer peripheral surface 20 is not particularly limited, and a polygonal shape, a polyhedral shape, or the like can be adopted. However, in this embodiment, the outer peripheral surface 20 is a cylindrical outer peripheral surface.

  On the other hand, the shape of the inner peripheral surface 22 is a cylindrical inner peripheral surface extending linearly on one axis. In particular, in the present embodiment, a bottom side boundary line 26 extending in the circumferential direction is set at a portion closer to the bottom wall portion 24 as a bottom wall than the central portion in the axial direction. Further, an opening side boundary line 30 extending in the circumferential direction is set in a portion closer to the opening 28 than the central portion in the axial direction.

  The inner peripheral surface on the bottom wall portion 24 side with the bottom-side boundary line 26 is a tapered bottom-side tapered surface 32 that gradually decreases in diameter toward the bottom wall portion 24. Further, the inner peripheral surface on the opening 28 side across the opening-side boundary line 30 is a tapered opening-side tapered surface 34 that gradually increases in diameter toward the opening 28.

  Furthermore, the central part located between the bottom part side boundary line 26 and the opening part side boundary line 30 among the inner peripheral surfaces 22 of the housing body 16 is a straight surface 36 extending in a cross-sectional shape having a constant inner diameter. In addition, the bottom side boundary line 26 between the straight surface 36 and the bottom side taper surface 32 and the opening side boundary line 30 between the straight surface 36 and the opening side taper surface 34 have a clear bending point in the longitudinal section. In addition, a curved shape that is smoothly connected with an appropriate curvature may be used.

  As is clear from this, the housing body 16 of this embodiment includes a bottom side taper portion 38 that forms the bottom side taper surface 32, a straight portion 40 that forms the straight surface 36, and an opening portion taper surface 34. The opening side taper portion 42 to be formed is included.

  Further, the opening 28 of the housing body 16 has an outer diameter that is reduced from the opening edge to a predetermined length in the axial direction, so that the lid fits at the opening end of the opening 28. A portion 44 is formed. In the present embodiment, the opening 28 in which the cover fitting portion 44 is formed in the housing main body 16 has a substantially constant inner diameter. That is, the inner peripheral surface of the opening 28 is a cylindrical surface that spreads with a constant inner diameter from the axial end that is the maximum outer diameter of the opening-side tapered surface 34 to the opening edge of the housing body 16. ing.

  And the cover body 18 is assembled | attached with respect to the cover fitting part 44 in such a housing main body 16. FIG.

  The lid 18 has a disk shape having an outer diameter substantially the same as the outer diameter of the housing main body 16, and an outer fitting cylindrical portion 46 that projects from the outer peripheral edge to one side in the axial direction is integrally formed. ing. The cover 18 is fixed to the opening 28 of the housing main body 16 by externally fitting the external fitting cylindrical portion 46 to the cover fitting portion 44 of the housing main body 16.

  The lid 18 can be fixed to the housing main body 16 by press-fitting the external fitting cylinder portion 46, but it is desirable to fix the lid 18 by bonding or welding in order to firmly fix it. Further, a locking mechanism portion such as a concave-convex engaging portion or a screw at a position corresponding to the inner peripheral surface of the outer fitting cylindrical portion 46 in the lid 18 and the outer peripheral surface of the lid fitting portion 44 of the housing body 16. It is also possible to perform mechanical fixing by providing a screwed portion made of a groove and a thread.

  Further, the lid 18 is integrally formed with an inward projection 48 at the center thereof. The inward projecting portion 48 is spaced from the inner peripheral side of the outer fitting tube portion 46 and projects in the axial direction on the central axis of the lid 18. In particular, in the present embodiment, the inward projecting portion 48 is formed so as to project with a circular cross section having an outer diameter smaller than the opening side tapered surface 34 of the housing body 16.

  Then, in a state where the lid body 18 is assembled to the opening end portion of the housing body 16, the inward protrusion 48 of the lid body 18 enters from the opening end portion of the housing body 16 toward the axially inward direction. It is positioned. In the present embodiment, the inward protrusion 48 is projected into the housing body 16 to the extent that it reaches the opening-side tapered surface 34 of the housing body 16. The inward projection 48 limits the axial movement end of the independent mass 14 accommodated in the housing body 16.

  In this way, the lid 18 is assembled to the opening 28 of the housing main body 16, thereby covering the opening 28 of the housing main body 16, thereby forming the case housing 12. In the case housing 12, a mass accommodating space 50 that is cut off from the external space is defined. The independent mass 14 is accommodated in the mass accommodating space 50.

The mass accommodating space 50 formed in this way has an axial internal dimension: LA ₁ that is smaller than the depth dimension of the case housing 12 by the protruding height of the inward protrusion 48 in the lid 18. Have. Further, the inner diameter dimension of the mass accommodating space 50 is set to a constant inner diameter dimension: φDA on the straight surface 36.

  Here, the housing body 16 is formed of a suitable synthetic resin material such as polypropylene, polycarbonate, nylon, or the like, or a fiber reinforced material thereof. In particular, in this embodiment, it is formed of a thermoplastic synthetic resin material. Further, the material of the lid 18 is not particularly limited, but is preferably formed of a synthetic resin material or a rubber material similar to the housing body 16. In particular, by employing the lid 18 formed of a thermoplastic synthetic resin material, the lid 18 can be welded to the housing body 16.

  Further, the mass accommodating space 50 formed in the case housing 12 may be fluid-tightly sealed with respect to the external space. In order to realize such a sealed structure, it is effective to continuously weld or bond the lid 18 to the housing body 16 over the entire circumference. Alternatively, a sealing material such as an O-ring can be disposed at the assembly part of the lid 18 to the housing body 16.

  The housing body 16 has a bottomed cylindrical shape having a bottom wall portion 24 and a peripheral wall portion that is long in the axial direction. For example, the housing body 16 is advantageously manufactured by being integrally formed by suitably adopting injection molding. Can be done.

  The molding die for molding the outer peripheral surface 20 of the housing main body 16 is divided into a plurality of parts on the circumference of the housing main body 16 in addition to the molding die that is released in the axial direction of the housing main body 16, and is outside in the direction perpendicular to the axis. A split mold or the like that is released in the direction can be appropriately employed without any particular structural limitation. On the other hand, the molding die for molding the inner peripheral surface 22 of the housing body 16 is preferably a rod-shaped one that extends integrally in the axial direction. With such an integral rod-shaped molding die, the bottom side taper surface 32, the straight surface 36 and the opening side taper surface 34 constituting the inner peripheral surface 22 of the housing body 16 are integrally molded. .

  As a result, the bottom-side tapered surface 32, the straight surface 36, and the opening-side tapered surface 34 are continuously formed on the same central axis with extremely high accuracy without causing stepped surfaces or the like at the boundary lines 26 and 30. Thus, it can be integrally formed to give the desired shape of the inner peripheral surface 22.

  Here, the bottom taper surface 32 is provided with a taper that gradually increases in diameter in the direction of removing the molding die on the inner peripheral surface 22 after molding (the direction of demolding). Accordingly, in the portion where the bottom side taper surface 32 is formed, the forming taper surface shape can be provided as a taper taper at the time of demolding on the outer peripheral surface of the deepest portion (tip portion) of the rod-shaped forming die. It will be. As a result, the long bottomed cylindrical inner peripheral surface 22 can be easily and stably formed by the single rod-shaped forming die as described above.

  In particular, in the present embodiment, since the opening side taper surface 34 is also provided over a predetermined length in the opening portion of the inner peripheral surface 22 of the housing body 16, the opening side taper surface 34 is also formed on the housing body. When 16 is formed, it functions effectively so as to provide a taper with respect to the molding die of the inner peripheral surface 22. As a result, the desired deep bottomed cylindrical inner peripheral surface 22 can be provided more advantageously in the housing body 16 by a single rod-shaped molding die.

  The inclination angle θA between the bottom side taper surface 32 and the opening side taper surface 34 in the housing body 16 is not particularly limited, and an inclination angle (θB) given to the independent mass 14 described later is also taken into consideration. For example, it is preferably set to 0.1 degree ≦ θA ≦ 20 degrees, and more preferably 1 degree ≦ θA ≦ 10 degrees. If the lid is covered and the taper angle is too small, the function as a taper taper at the time of molding may not be sufficiently exerted. This is because it may be difficult to ensure the safety.

  On the other hand, the independent mass 14 has a solid circular rod shape as a whole as shown in FIG.

  The independent mass 14 is made of a metal material having a high specific gravity such as iron and has a solid rod shape extending straight in the axial direction with a circular cross section. In addition, a boundary line 52 is formed on the outer peripheral surface of the independent mass 14 so as to continuously extend in the circumferential direction at the intermediate portion in the axial direction. Then, one side in the axial direction from the boundary line 52 (left side in FIG. 5) has a tapered outer peripheral surface 54 that gradually decreases in diameter toward the tip in the axial direction, and a tapered portion 56 as a bottom side extending portion. It is said that. The tapered portion 56 has a smaller outer peripheral surface shape than the bottom side tapered portion 38 of the housing body 16.

  In the independent mass 14, the boundary line 52 is set so as to be biased toward the tapered portion 56 rather than the center in the axial direction. Thereby, the axial direction length of the contact part 60 mentioned later rather than the taper part 56 is enlarged. The taper portion 56 of the independent mass 14 is accommodated on the bottom side taper portion 38 side of the housing body 16, while the contact portion 60 is accommodated in the opening side taper portion 42 and the straight portion 40.

  On the other hand, in the independent mass 14, the other side in the axial direction from the boundary line 52 (the right side in FIG. 5) has a cylindrical outer peripheral surface 58 extending over the entire length in the axial direction with a circular cross section having a constant outer diameter. It is set as the contact part 60 which has. In addition, the boundary line 52 may be a curved shape that is smoothly connected with an appropriate curvature in addition to a clear bending point in the longitudinal section.

  When vibration is input to the vibration isolator 10 and the independent mass 14 jumps and displaces in the case housing 12, the contact portion 60 contacts the straight surface 36 of the straight portion 40 of the case housing 12. As a result, the vibration control effect is exhibited.

Further, the axial length dimension LB ₁ of the independent mass 14 is set to be smaller by a predetermined dimension than the axial internal dimension LA ₁ of the mass accommodating space 50 in the case housing 12. Further, the outer diameter dimension of the independent mass 14 is set such that the outer diameter dimension of the contact portion 60: φDB is smaller than the inner diameter dimension of the straight portion 40 of the mass accommodating space 50 in the case housing 12: φDA. .

Furthermore, the axial length: LB ₂ of the tapered portion 56 in the independent mass 14 is made larger than the axial length: LA ₂ of the bottom side tapered portion 38 of the mass receiving space 50 in the case housing 12. In short, the boundary line 52 of the independent mass 14 forms the bottom portion of the case housing 12 with the axial front end face 64 on the tapered portion 56 side of the independent mass 14 superimposed on the inner surface of the bottom wall portion 24 of the case housing 12. It is designed to be positioned closer to the opening 28 than the side boundary line 26.

  The tapered portion 56 of the independent mass 14 has an inclination angle: θB set equal to or larger than the inclination angle: θA of the bottom side tapered surface 32 of the case housing 12. That is, θB ≧ θA.

  Thus, as long as the independent mass 14 jumps and translates relative to the case housing 12 in a state where the independent mass 14 is accommodated in the mass accommodation space 50 of the case housing 12, that is, the center of the independent mass 14. The independent mass 14 does not hit the bottom side taper surface 32 of the case housing 12 unless the shaft tilts a predetermined amount or more in the twisting direction with respect to the central axis of the case housing 12.

In the present embodiment, in the axial direction of the case housing 12, the axial length LA ₃ of the straight surface 36 is set to be equal to or more than ¼ of the axial total length LA ₁ of the mass accommodation space 50. More preferably, it is set to the center in the substantially axial direction with a length of 1/3 or more. Further, the axial length of the bottom side taper surface 32: LA _2, the axial length of the mass housing space 50: against LA _1, it is desirable to set the 2/5 or less, more preferably It is set to 1/3 or less.

Furthermore, also in the independent mass 14, it is preferable that the axial length LB _{3 of the} contact portion 60 is set to 1/4 or more of the axial total length LB ₁ , and more preferably 1/3 or more. Is set at the center in the axial direction. The axial length LB ₂ of the taper portion 56 is preferably set to 4/7 or less, more preferably 2/5 or less of the total axial length.

  The inclination angle θA of the bottom-side tapered surface 32 of the case housing 12 is desirably set to 0.5 degrees ≦ θA ≦ 30 degrees, and more preferably 1 degree ≦ θA ≦ 20 degrees. If the lid is inclined and the angle of inclination: θA is too small, the taper action at the time of molding is not sufficiently exhibited, whereas if it is too large, it is difficult to efficiently secure the mass of the independent mass 14. . Further, as described above, the inclination angle θB of the tapered portion 56 of the independent mass 14 is set to an inclination angle equal to or less than the inclination angle θA of the bottom side tapered surface 32, but the difference between θA and θB is It is desirable to set it to 10 degrees or less, more preferably 5 degrees or less, and even more preferably 1 degree or less. It is because it becomes difficult to ensure the mass of the independent mass 14 efficiently when the difference is increased.

  In the present embodiment, the independent mass 14 is also in the axial direction end opposite to the taper portion 56, that is, the end portion on the side positioned in the opening side taper portion 42 in the case housing 12. Extends straight up to the end in the axial direction and has a straight shape extending with a constant outer diameter.

  However, for example, the axial direction end opposite to the tapered portion 56 in the independent mass 14 is increased in diameter toward the axial end at an inclination angle equal to or smaller than the opening-side tapered surface 34 of the case housing 12. By using the tapered portion, it is possible to secure a more efficient mass mass.

  Alternatively, for example, the axial end portion of the independent mass 14 opposite to the tapered portion 56 may have a tapered surface shape that gradually decreases in diameter toward the axial end portion in the same manner as the tapered portion 56. In particular, it is also advantageous to form tapered portions 56, 56 having the same shape on both sides in the axial direction of the independent mass 14 so that the independent mass 14 has a symmetrical shape in the axial direction. In such a symmetrical independent mass 14, there is no need to distinguish between the axial directions. Therefore, when inserting and assembling the case housing 12, it is not necessary to distinguish between the axial directions, and the work becomes easy. In addition, since the weight balance on both sides in the axial direction is improved, when the independent mass 14 jumps in the case housing 12, the tilting is effectively suppressed, and the jump displacement can be stabilized.

  In the vibration isolator 10 in which the independent mass 14 having the above-described structure is accommodated in the mass accommodating space 50 of the case housing 12, the independent mass 14 is arranged in the central portion in the axial direction in the mass accommodating space 50. FIG. 2 and FIG. 3 show the state of being positioned on the same central axis. It should be noted that under the mounting state in the actual apparatus, the independent mass 14 is placed in the mass accommodating space 50 by the action of gravity, and vibration is applied to the independent mass 14 from the case housing 12. However, here, it is assumed that the independent mass 14 is virtually positioned coaxially in the mass accommodating space 50.

Under such an arrangement state of the independent mass 14 in the center of the mass accommodation space 50, a continuous gap 62 is formed between the entire surface of the independent mass 14 and the entire inner surface of the mass accommodation space 50. The size of the gap 62, the axial length of the bottom side tapered portion 38 of the housing body 16 such as described above: the axial length of the tapered portion 56 of the LA ₂ independent mass 14: difference between LB _2, and the housing Based on the difference between the inclination angle of the bottom side taper portion 38 of the main body 16: θA and the inclination angle of the taper portion 56 of the independent mass 14: θB, the size of the gap 62 in the contact portion 60 of the independent mass 14: δa is The size of the gap 62 in the tapered portion 56 is set to be smaller than δb. That is, in the size of the gap 62 shown in FIGS.

  In particular, in the present embodiment, the gap 62 in the contact portion 60 of the independent mass 14 can be obtained even when the axial front end surface 64 on the tapered portion 56 side of the independent mass 14 is superimposed on the inner surface of the bottom wall portion 24 of the case housing 12. The size: δa is set to be smaller than the size of the gap 62 in the tapered portion 56: δb. As a result, as described above, as long as the independent mass 14 is displaced in a translational manner, the independent mass 14 strikes the case housing 12 only at the contact portion 60.

  The radial gap δa between the independent mass 14 and the case housing 12 is preferably 0.05 to 2.0 mm, and more preferably 0.1 to 1.0 mm. If the gap in the radial direction: δa is too small, an allowable error in manufacturing the component becomes small and the manufacturing becomes difficult, and the gap 62 is substantially lost due to the component error. This is because the effect may not be exhibited. On the other hand, if the radial gap: δa is too large, the impact of the independent mass 14 on the case housing 12 will be too great, resulting in the occurrence of sound and the like. This is because it may become a problem.

  Further, in the present embodiment, the size of the gap 62 between the opening-side tapered surface 34 in the opening-side tapered portion 42 of the housing main body 16 and the outer peripheral surface of the independent mass 14 is equal to the straight in the straight portion 40 of the housing main body 16. The size of the gap 62 between the surface 36 and the contact portion 60 of the independent mass 14 is larger than δa. Accordingly, as long as the independent mass 14 is jumped and displaced in translation, the contact between the independent mass 14 and the housing main body 16 at the opening side taper portion 42 is avoided.

Further, the difference between the axial length of the independent mass 14: LB ₁ and the axial internal dimension of the case housing 12: LA ₁ is sufficiently large so as not to inhibit the jumping displacement of the independent mass 14 in the direction perpendicular to the axis. In addition, the large displacement in the axial direction can be regulated so that the contact portion 60 of the independent mass 14 repeats striking without causing a large relative displacement in the axial direction with respect to the straight surface 36 of the case housing 12. Set to

  The vibration isolator 10 having the above-described structure is fixed to a vibration member (not shown) whose case housing 12 is a vibration control target so that the central axis of the case housing 12 faces in the horizontal direction. It will be attached to.

  Under such a mounted state, for example, the vibration of the vibration member mounted with the case housing 12 such as a power unit, subframe, and body in an automobile exerts on the case housing 12 in a substantially vertical direction (vertical direction in FIGS. 1 to 3). Then, vibration is transmitted from the case housing 12 to the independent mass 14, and the independent mass 14 jumps and is displaced in the mass accommodating space 50. As a result, the independent mass 14 repeatedly hits the inner surface of the mass accommodating space 50 in the case housing 12 vertically and vertically, and as a result, an effective damping effect is exerted on the vibration member. .

  Here, since the case housing 12 is made of a synthetic resin material, it is lightweight and can be mass-produced at a low cost. Moreover, in the case housing 12 formed of a synthetic resin material, when the independent mass 14 is struck, the sound reduction effect is exhibited as compared with the housing member formed of a metal material, and the damping when deformed. The action is exhibited and the vibration damping effect can be improved.

  In addition, since the urging force in the jumping direction based on the elasticity of the case housing 12 formed of a synthetic resin material is applied to the independent mass 14 in the antigravity direction when the independent mass 14 strikes, the independent mass 14 14 jumps more efficiently and hits the case housing 12 with a large force. As a result, the intended damping effect can be more effectively exhibited.

  Thus, the case housing 12 formed of the synthetic resin material can be advantageously manufactured for the first time by the specific shape including the bottom side tapered surface 32 and the straight surface 36 as described above, and can be realized. In addition, since the independent mass 14 having a specific shape including the tapered portion 56 and the abutting portion 60 corresponding thereto is used in combination, the independent mass 14 strikes the case housing 12 in the direction perpendicular to the axis, thereby stabilizing the strike. It was possible to make effective and effective vibration control effects.

  In the present embodiment, since the case housing 12 is formed of a synthetic resin material, it is possible to suppress erosion due to oxidation as compared with the case where the case housing 12 is formed of a metal material. In particular, the housing member is exposed to the outside air when attached to the vibration member, and when it is attached to an automobile, it may be exposed to rain or splashing water from the road surface. There is a concern about the progress of rust generated on the outer surface to the inner surface. When the rust progresses, not only the strength of the case housing 12 is lowered, but also the gap size with the independent mass 14 and the impact characteristics when the independent mass 14 is hit are changed, and the vibration damping performance is adversely affected. However, in the case housing 12 formed of a synthetic resin material, the generation of rust on the outer peripheral surface 20 is completely avoided, and the progress of oxidative corrosion (rust) to the inside is also prevented. In particular, when the mass housing space 50 in the case housing 12 has a fluid-tight sealed structure, oxidation of the independent mass 14 inside is advantageously prevented. As a result, the intended damping effect is more stably and effectively exhibited.

  As mentioned above, although embodiment of this invention has been explained in full detail, this invention is not limited at all by the description. For example, in the embodiment described above, the opening side taper surface 34 is also provided on the opening 28 side of the case housing 12, but the taper surface on the opening 28 side has a depth dimension in the housing body 16 and a bottom portion. In consideration of the axial length of the side taper surface 32 and the straight surface 36, etc., it is provided as necessary and is not necessarily provided.

Further, a contact rubber made of a thin rubber layer is formed by vulcanization adhesion so as to cover the entire outer peripheral surface of the independent mass 14, or at least cover the cylindrical outer peripheral surface 58. It is also possible to provide it so as to cover it, whereby it is possible to alleviate the impact when the independent mass 14 strikes the case housing 12, to prevent sound hitting, and to further improve the damping effect. Such a contact rubber may be provided on the entire inner surface of the mass housing space 50 of the case housing 12 or at least the straight surface 36 in addition to or instead of the independent mass 14.

The longitudinal cross-sectional view which shows the vibration isolator as one Embodiment of this invention. II-II sectional drawing in FIG. III-III sectional drawing in FIG. The longitudinal cross-sectional view which shows the case housing in FIG. The longitudinal cross-sectional view which shows the independent mass in FIG.

Explanation of symbols

10: Vibration isolator, 12: Case housing, 14: Independent mass, 16: Housing body, 18: Cover body, 24: Bottom wall portion, 28: Opening portion, 38: Bottom side taper portion, 40: Straight portion, 42 : Tapered portion on the opening side, 48: Inward projecting portion, 50: Mass accommodating space, 56: Tapered portion, 60: Abutting portion, 62: Clearance

Claims (7)

In a vibration isolator in which an independent mass member is accommodated and disposed in a cylindrical housing member in a non-adhesive manner, and the independent mass member jumps against the housing member and repeatedly strikes upon vibration input,
The housing member has a bottomed cylindrical shape having a bottom wall at one end in the axial direction, and is formed of an integrally molded product of a synthetic resin material. The housing member has a constant inner diameter at a central portion in the axial direction. An extending straight portion and a bottom side taper portion that gradually decreases in diameter toward the bottom wall on the bottom side of the straight portion are formed, and the opening at the other axial end of the housing member is a lid member While the mass storage space is formed by being covered, the independent mass member received and disposed in the mass storage space has a constant outer diameter smaller than the inner diameter of the straight portion of the housing member. An abutting portion having a solid circular rod shape extending and accommodated in the straight portion of the housing member, and a bottom side taper portion of the housing member And has a bottom-side extending portion that extends in the axial direction from the corresponding contact portion and is accommodated in the bottom-side tapered portion of the housing member, and has a corresponding shape of the independent mass member. The clearance dimension between the outer peripheral surface of the contact portion and the inner peripheral surface of the straight portion of the housing member is such that the outer peripheral surface of the bottom-side extending portion of the independent mass member and the bottom-side tapered portion of the housing member When the independent mass member jumps with respect to the housing member due to vibration input, the corresponding contact portion with respect to the straight portion is made smaller than the size of the gap between the inner peripheral surface and the inner circumferential surface. An anti-vibration device characterized in that, when hitting, the bottom side extending portion is prevented from hitting the bottom side tapered portion.   2. The vibration isolation device according to claim 1, wherein the axial length of the bottom-side extending portion of the independent mass member is larger than the axial length of the bottom-side tapered portion of the housing member. apparatus.   In the independent mass member, the outer peripheral surface of the bottom side extending portion has a tapered shape that gradually decreases in diameter toward the tip in the axial direction, and the taper angle of the outer peripheral surface of the bottom side extending portion is determined by the housing. The vibration isolator according to claim 1 or 2, wherein the vibration isolator is larger than a taper angle of the bottom side taper portion of the member.   The housing member has an opening-side taper portion that gradually increases in diameter toward the opening portion on the opening side of the straight portion, and an inner peripheral surface of the opening-side taper portion. The clearance dimension between the outer peripheral surface of the independent mass member is made larger than the clearance dimension between the outer peripheral surface of the contact portion of the independent mass member and the inner peripheral surface of the straight portion of the housing member. The vibration isolator according to any one of claims 1 to 3, wherein the independent mass member is prevented from hitting the opening side taper portion.   Also in the portion where the independent mass member extends from the contact portion in the axial direction opposite to the bottom side extension portion and is accommodated in the opening side taper portion of the housing member, the same as the corresponding contact portion. The vibration isolator according to claim 4 which extends in the axial direction with a constant outer diameter.   The independent mass member is formed of a solid metal material, and the outer peripheral surface of the independent mass member directly hits the inner peripheral surface of the housing member formed of a synthetic resin material. The vibration isolator according to any one of claims 1 to 5. The lid member is formed with an inner protrusion that enters inward in the axial direction from the axial opening end of the housing member, and the axial movement end of the independent mass member is limited by the inner protrusion. The vibration isolator according to any one of claims 1 to 6.

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