JP2008223876A - Vibration damping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration damping device with novel structure capable of improving damping performance while securing industrial productivity. <P>SOLUTION: In this abutting type vibration damping device, an independent mass member 14 is enclosed in a non-contacting state and jumping displaceably in a housing 12 of hollow sealed structure mounted on a vibrating member to be damped, and upon input of vibration, the independent mass member 14 jumps and displaces with respect to the housing 12, and is elastically abutted on the housing 12 on both sides in the vibration input direction. Powder 38 is interposed in gaps 30, 36, 32 between outer faces 28, 32, 32 of the independent mass member 14 and inner faces 22, 34, 34 of the housing 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vibration damping device that is attached to a vibration member in which vibration is a problem and reduces the vibration of the vibration member.

  Conventionally, various types of vibration control devices have been proposed in order to reduce the vibration of a vibration member in which vibration is a problem. As one of them, a dynamic damper is known in which a mass member is elastically supported by a vibration member to be damped via a spring member to constitute a sub vibration system for the vibration member. However, the dynamic damper has a problem that it is difficult to exert an effective damping effect only in a specific frequency range in which the natural frequency of the secondary vibration system is tuned.

  In view of this, the applicant previously described in Patent Document 1 that the independent mass member is housed and disposed in a non-adhering and displaceable manner with respect to the housing fixed to the vibration member so that the vibration can be input independently. We proposed a damping device that obtains a damping effect by elastically hitting the mass member against the housing, utilizing sliding friction at the time of hitting, energy loss due to collision, and the like. In such a vibration damping device, it is possible to exert a vibration damping effect against vibrations in a wide frequency range with a small mass.

  By the way, in the hitting vibration damping device as described above, in recent years, further improvement of the vibration damping performance has been demanded, and in particular, further improvement of the damping performance has been demanded. In order to meet such a demand, the present inventor has examined that it is desirable to sufficiently reduce the gap formed between the contact surface of the independent mass member and the housing.

  However, even when an attempt is made to make the gap formed between the contact surface of the independent mass member and the housing sufficiently smaller than 1 mm, preferably on the order of several hundred microns, when manufacturing the independent mass member or the housing, the dimensional error In view of industrial productivity in particular, there is a problem that it is extremely difficult to sufficiently reduce the gap formed between the contact surface of the independent mass member and the housing.

International Publication No. 00/14429 Pamphlet

  Here, the present invention has been made in the background as described above, and the problem to be solved is that it is possible to further improve the damping performance while ensuring industrial productivity. The object is to provide a vibration damping device having a novel structure.

  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.

  The present invention accommodates and disposes an independent mass member in a non-adhering and displaceable manner with respect to a housing having a hollow hermetic structure attached to a vibration member to be damped, and includes a surface of the independent mass member and an inner surface of the housing. When the vibration is input, the independent mass member jumps and displaces against the housing and elastically strikes the housing on both sides in the vibration input direction. The vibration damping device according to the present invention is characterized in that a powder smaller than the gap is interposed in the gap between the surface of the independent mass member and the inner surface of the housing.

  In the vibration damping device having such a structure according to the present invention, the independent mass member hits the housing through the powder when the vibration is input. In short, the gap between the contact surface of the independent mass member and the housing is substantially set by the powder so that the gap between the contact surface of the independent mass member and the housing is as small as the powder. It is set.

  Therefore, in designing and manufacturing processes of independent mass members and housings, the contact surfaces of the independent mass members and the housing should be large enough to accommodate the independent mass members in the housing in consideration of manufacturing errors. The gap dimension can be set to be substantially sufficiently small by setting the gap dimension therebetween while interposing the powder there. In particular, since the powder is smaller than the set gap size, after the independent mass member and the housing are manufactured, they are combined before and after the combination, and before the housing is sealed. The size of the gap between the contact surface of the independent mass member and the housing can be adjusted appropriately afterwards by simply putting powder between the contact surfaces of the mass member and the housing.

  Therefore, in the present invention, as described above, the substantial size of the gap between the contact surface of the independent mass member and the housing is corrected by using powder after manufacturing the parts, and is set to be sufficiently small and substantially constant. It becomes possible to do. As a result, the desired vibration damping effect based on the striking action of the independent mass member against the housing can be enjoyed stably without the need for remarkably sophisticated part dimension management that is a problem in industrial production. It becomes possible to do.

  In addition, in the vibration damping device structured according to the present invention, when the independent mass member strikes the housing, the vibration damping performance is improved based on the frictional action of the powder itself interposed between the bumping surfaces. The effect is also demonstrated. That is, at the time of hitting, the elastic hitting surface is complicated and elastically deformed so that the powder enters the elastic hitting surfaces of the independent mass member and the housing, or the powder itself is complicated. By performing elastic deformation, it is possible to improve the damping effect accompanying the elastic deformation between the striking surfaces. Also, when hitting, friction between powders will also occur, and based on this friction, further damping effect and vibration energy absorption effect will be exhibited, so that the damping performance can be improved. is there.

  By the way, the specific shape of the independent mass member and the housing adopted in the present invention is not particularly limited, and for example, the independent mass member such as a rectangular block shape or a ball shape and the inner peripheral surface shape corresponding to the outer peripheral surface shape. Such as a combination of housings, a combination of an independent mass member with a spherical outer peripheral surface and a housing with a polyhedral inner peripheral surface, the jumping displacement of the independent mass member in the vibration input direction to be damped and the impact on the housing are manifested Various structures are adopted.

  Here, the cross-sectional shape in the vibration input direction of the surface of the independent mass member and the cross-sectional shape in the vibration input direction of the inner surface of the housing are preferably similar to each other. As a result, the size of the gap between the independent mass member and the housing can be made substantially constant in the circumferential direction with the independent mass member positioned at the center of the displacement direction in the housing. By efficiently dispersing the body, it is possible to more stably enjoy the substantial reduction effect of the gap between the striking surfaces due to the presence of the powder.

  Particularly preferably, an independent mass member having a cylindrical outer peripheral surface is employed, and a housing having a cylindrical inner peripheral surface that is slightly larger than the outer peripheral surface of the independent mass member is employed. The configuration is such that the vibration to be damped is input in the direction perpendicular to the axis of the independent mass member and the housing, and the cylindrical outer peripheral surface of the independent mass member and the cylindrical inner peripheral surface of the housing abut against each other. The

  Thus, by making the contact surface into a similar cylindrical surface shape, the improvement of the damping effect and the improvement of the vibration damping effect by interposing the powder between the contact surfaces can be realized more efficiently. In other words, in the case of a similar cylindrical surface shape, assuming that the hitting surface does not deform, it will be a hit per line extending linearly in the axial direction. This is because the contact surface greatly extends on both sides in the circumferential direction and comes into contact with the surface. In short, in the case of a similar cylindrical surface hitting surface, assuming that the hitting surface does not deform, with the independent mass member hitting the housing, from the part that hits the center line to both sides in the circumferential direction The gap gradually becomes larger. This gradually changing gap exists as long as the size of the gap is made sufficiently small and a similar cylindrical contact surface is employed. However, by interposing the powder in the gap, the amount of the powder is automatically adjusted according to the size of the gap, so that the contact surface can be formed over a wide area. is there.

  As a result, the shear deformation accompanying the hitting of the contact rubber layer constituting the hitting surface can be efficiently generated in a wide region, and the damping effect and the vibration damping effect based thereon can be greatly improved. In addition to this, even in the powder intervened in the gap, the damping effect based on friction and deformation is exhibited over a wide region, and the intended vibration damping effect can be further improved. .

  In addition, by adopting an independent mass member with a cylindrical outer peripheral surface, rotation of the independent mass member around the central axis within the housing is allowed, and the contact portion of the independent mass member with respect to the housing appropriately changes in the circumferential direction. Will be. As a result, uneven wear or the like of the independent mass member is avoided, durability is improved, and a stable vibration damping effect can be obtained over a long period of time.

  In addition, the contact and surface of the independent mass member and the housing, which are brought into contact with each other by interposing the powder, can be deformed flexibly based on the fluidity of each powder. Therefore, the flow or movement of the powder occurs in the powder layer at the time of hitting, and a larger friction is generated between the powders or at the contact portion between the powder and the independent mass member or the housing. As a result, the internal friction of the contact rubber layer and the powder layer and the external friction at the contact surface of the independent mass member and the housing work more efficiently, and a greater damping effect and thus a damping effect is exhibited. Will get.

  Note that the powder in the present invention is, for example, a powder using an organic compound such as wheat flour, a carbonate such as calcium carbonate, a powder of an inorganic compound such as a synthetic resin, or a metal oxide. It can be constituted by a mixture of a plurality of types. In particular, inorganic powders are preferably employed from the viewpoint of less deterioration due to the environment and deterioration with time.

  In the present invention, the amount of powder interposed in the gap between the surface of the independent mass member and the inner surface of the housing is not particularly limited. Of course, a space as a gap may remain between the contact surfaces of the independent mass members with respect to the housing, and the gap may be almost filled with powder.

  For the purpose of adjusting the size of the gap in the order of several hundred microns, in the present invention, a configuration employing a powder having a particle size in the range of 10 to 100 μm (for example, as an average value) is preferable. Adopted.

  Further, in the present invention, for the same reason, a configuration employing a powder having an average particle size of 1/2 or less of the gap size, more preferably 1/5 or less, and even more preferably 1/10 or less, Preferably employed. However, it is difficult to handle a powder having a too small particle size.

  In particular, by using a powder having a particle size of 10 to 100 μm as described above, friction between powders is more efficiently generated when the independent mass member strikes the housing. That is, when the particle size of the powder is smaller than 10 μm, the surface area of the powder becomes too small, and it becomes difficult to effectively generate friction between the powders. Is larger than 100 μm, the amount of powder intervened in the gap is reduced, and it may be difficult to ensure a large amount of friction generated between the powders.

  In the present invention, a configuration in which the size of the gap in the vibration input direction is 0.1 to 0.5 mm in a state where the independent mass member is brought close to one moving end with respect to the housing is suitably employed. .

  In the aspect employing such a configuration having the gap size, it is possible to more effectively obtain the friction generated between the powders when the independent mass member hits the housing. In other words, if the size of the gap in the vibration input direction is smaller than 0.1 mm with the independent mass member moved toward one moving end with respect to the housing, the dimensional error allowed in industrial production becomes severe. Therefore, problems such as an increase in manufacturing cost are likely to occur. In addition, since the gap becomes too small, the amount of powder intervened in the gap is reduced, and it may be difficult to sufficiently secure the friction generated between the powders. On the other hand, if the gap is larger than 0.5 mm, the required amount of powder increases, making the powder input operation cumbersome. It is feared that the intervening effect becomes difficult to be exhibited, and there is a risk that the performance becomes unstable due to a change in the amount of powder input.

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

  1 and 2 show a vibration damping device 10 as an embodiment of the present invention. The vibration damping device 10 has a structure in which a separate independent mass member 14 is accommodated and disposed so as to be relatively displaceable without being bonded to the housing 12, and the housing 12 is a vibration member (not shown) to be a vibration damping target. Z)). In the present embodiment, the main vibration of the vibration member is input to the vibration control device 10 in the vertical direction in FIG.

More specifically, the housing 12 according to the present embodiment includes a housing body 16 and a pair of lids 18 and 18. The housing body 16 is made of a rigid material such as steel or aluminum alloy, and has a thick cylindrical shape. In addition, it is also possible to employ | adopt a hard synthetic resin material as a forming material of the housing main body 16, In that case, the synthetic resin material which has an elasticity modulus of 5 * 10 < ³ > -5 * 10 < ⁴ > MPa is suitable. Adopted.

  On the other hand, each of the pair of lids 18 and 18 is made of a rigid material such as steel, an aluminum alloy, or a hard synthetic resin material, and has a disk shape as a whole. Each lid 18 has its outer peripheral edge overlapped with the opening peripheral edge of the housing body 16 and is fixed by welding, bonding, or the like. Thereby, each opening part of the housing main body 16 is covered with the cover body 18, and the housing 12 of the airtight structure in which the accommodation space 20 extended in the longitudinal direction with the substantially constant circular cross section was formed is comprised. ing. That is, the housing 12 of the present embodiment includes a cylindrical inner peripheral surface 22 that extends substantially straight in the axial direction with a substantially constant circular cross section.

  Further, the independent mass member 14 of the present embodiment has a structure in which the surface of the mass metal fitting 24 is covered with a contact rubber film 26 as a contact rubber layer, and the surface is formed of the contact rubber film 26. In particular, in this embodiment, the entire surface of the mass metal fitting 24 formed of a high specific gravity material such as steel and having a substantially constant circular cross section and extending straight is formed of a conventionally known rubber material. The contact rubber film 26 is covered with a substantially constant thickness. That is, the independent mass member 14 of the present embodiment includes a cylindrical outer peripheral surface 28 that extends straight in the axial direction with a substantially constant circular cross section. In particular, in the present embodiment, the circular outer peripheral surface 28 has a circular shape. The cross section is a similar shape that is slightly smaller than the circular cross section of the cylindrical inner peripheral surface 22 of the housing 12. Note that the contact rubber film 26 of the present embodiment is bonded to the surface of the mass fitting 24 at the same time as the vulcanization molding.

  Therefore, the abutting rubber film 26 advantageously obtains a vibration damping effect based on the contact of the independent mass member 14 against the housing 12 and a reduction effect of a hitting sound generated when the independent mass member 14 strikes the housing 12. In addition, the Shore D hardness of ASTM standard D2240 is preferably set to 80 or less, more preferably 20 to 40.

  In the present embodiment, the mass of the mass metal fitting 24, the spring constant of the contact rubber film 26, and the like are appropriately set so that the independent mass member 14 greatly jumps and displaces using a resonance characteristic in a specific frequency range. Has been.

  The independent mass member 14 having such a structure is accommodated in the accommodating space 20 of the housing 12 so as to be relatively displaceable without adhesion, and as shown in FIG. With the independent mass member 14 positioned on the same central axis, the cylindrical outer peripheral surface 28 (cylindrical outer peripheral surface 28 of the abutting rubber film 26) constituting a part of the surface of the independent mass member 14 and the housing 12. The size of the gap 30 with the cylindrical inner peripheral surface 22 constituting a part of the inner surface is 0.05 mm to 0.25 mm, preferably 0.1 mm to 0.15 mm. In other words, the dimension of the gap 30 in a state where the independent mass member 14 is brought close to one moving end with respect to the housing 12 is 0.1 mm to 0.5 mm, preferably 0.2 mm to 0.3 mm. is there. FIG. 3 shows a state in which a powder 38 to be described later does not exist, and each member is not hatched.

  Further, as shown in FIG. 2, with the independent mass member 14 positioned at the center in the axial direction of the housing 12, the axial end surface 32 constituting a part of the surface of the independent mass member 14 and the housing 12. A gap 36 having a predetermined size is also formed between the inner surface 34 of the lid 18 constituting a part of the surface.

  Further, powder 38 is interposed in the gaps 30, 36, 36 between the surfaces 28, 32, 32 of the independent mass member 14 and the inner surfaces 20, 34, 34 of the housing 12. This powder 38 is a powder using an organic compound such as wheat flour, a carbonate such as calcium carbonate, a powder of an inorganic compound such as a synthetic resin or a metal oxide, or a mixture of a plurality of types. In particular, in this embodiment, the particle size is 10 μm to 100 μm.

  As the powder 38, any powder conventionally used for vibration reduction and sound absorption can be used. For example, vermiculite powder, gold mica powder, wet silica powder, Acrylic resin powder such as spherical silica powder, ultra-fine acrylic powder, talc powder, calcium silicate powder, fluororesin powder, perlite powder, bentonite powder, Shirasu balloon, Ishimatsuko, Bullulan, fused silica Powder, graphite, crystalline cellulose powder, silicon carbide powder, nylon powder, acrylic powder coating, polyester powder coating, wheat flour such as strong powder and thin flour, dolomite powder, carbon fiber powder, titanium dioxide powder, heavy Calcium carbonate powder such as carbonaceous calcium carbonate powder, vinyl chloride resin powder, polymethyl methacrylate powder, silicone powder, electrofused magnesia powder, full fat milk, Ferrite calcined powders such as cerium ferrite magnetic powder, carbon black powder, and chlorinated titanium oxide powder can all be used, but from the viewpoint of less deterioration due to the environment and deterioration over time, inorganic compounds These powders are preferably employed.

  Further, as a method of interposing the powder 38 in the gaps 30, 36, 36 between the surfaces 28, 32, 32 of the independent mass member 14 and the inner surfaces 22, 34, 34 of the housing 12, for example, an independent mass member manufactured in advance is used. The independent mass member 14 in which the powder 38 is attached to the surfaces 28, 32, 32 of the 14 is inserted into the housing body 16, and in this state, each opening portion of the housing body 16 is covered with the lid 18; After the independent mass member 14 is inserted into the housing main body 16, the powder 38 is put into the housing main body 16 from the other opening portion in a state where one opening portion of the housing main body 16 is closed by the lid body 18. A method of covering the other opening portion of the housing body 16 with the lid 18, a method of combining them, or a state in which the powder 38 is substantially filled in the housing body 16. After turning, insert the independent mass member 14 to push the excess powder 38, then, such a method for covering the openings at both ends of the housing body 16 with the lid 18, 18 is employed.

  In order to attach the powder 38 to the surfaces 28, 32, 32 of the independent mass member 14, for example, the independent mass member 14 may be rolled and adhered on the layer of the powder 38 existing on a plane. is there. In that case, in order to further increase the deposition efficiency, it is possible to deposit a liquid that easily evaporates on the surface of the independent mass member 14.

  By the way, in this embodiment, the independent mass member 14 having the powder 38 attached to the surfaces 28, 32, 32 is formed from the other opening portion with respect to the housing main body 16 whose one opening portion is covered with the lid body 18. After the insertion, the gaps 30, 36 between the surfaces 28, 32, 32 of the independent mass member 14 and the inner surfaces 22, 34, 34 of the housing 12 are covered by a method of covering the other opening of the housing body 16 with the lid 18. 36, a powder 38 is interposed.

  The gaps 30, 36, 36 between the surfaces 28, 32, 32 of the independent mass member 14 and the inner surfaces 22, 34, 34 of the housing 12 do not need to be filled with the powder 38. In the gaps 30, 36, 36 between the surfaces 28, 32, 32 of the independent mass member 14 and the inner surfaces 22, 34, 34 of the housing 12, spaces may remain together with the powder 38. The filling degree of the powder 38 and the remaining degree of the space can be appropriately adjusted in consideration of the required attenuation performance and the like. Further, by adjusting the filling degree of the powder 38 and the remaining degree of the space, it is possible to adjust the degree that the independent mass member 14 jumps independently from the housing 12 in the vibration input direction.

  Although the vibration damping device 10 having such a structure is not illustrated, for example, an appropriate mounting bracket is attached to the outer peripheral surface of the housing 12, and the vibration member (not illustrated) is attached to the housing 12 via the mounting bracket. To be fixedly attached.

  When the vibration of the vibration member is input to the housing 12 with the vibration damping device 10 fixed to the vibration member in this way, the independent mass member 14 jumps independently from the housing 12 in the vibration input direction. In this embodiment, in particular, in the present embodiment, the cylindrical outer peripheral surface 28 of the independent mass member 14 and the cylindrical inner surface of the housing 12 are in contact with each other. The peripheral surface 22 hits. As a result, a damping effect based on energy loss, sliding friction, and the like due to the contact of the independent mass member 14 with the housing 12 is exhibited.

  Therefore, in the vibration damping device 10 having the above-described structure, the gaps 30, 36, 36 between the surfaces 28, 32, 32 of the independent mass member 14 and the inner surfaces 22, 34, 34 of the housing 12, particularly vibrations. Since the powder 38 is interposed in the gap 30 between the cylindrical outer peripheral surface 28 of the independent mass member 14 and the cylindrical inner peripheral surface 22 of the housing 12, which becomes a gap in the input direction, the independent mass member 14. It is possible to make the contact surface of the housing 12 with respect to the housing 12 substantially larger (in particular, larger on both sides in the circumferential direction) than when the powder 38 is not interposed in the gap 30. As a result, when the independent mass member 14 hits the housing 12, it is possible to widen a range in which friction due to contact occurs. Further, in the contact rubber film 26, it is possible to widen a range in which elastic deformation based on the contact of the independent mass member 14 with the housing 12, that is, internal friction (attenuation) is generated. In addition, it is possible to cause friction between the powders 38 due to an impact when the independent mass member 14 hits the housing 12.

  Therefore, in the vibration damping device 10 having the above-described structure, it is possible to generate a larger friction when the independent mass member 14 hits the housing 12, and as a result, the damping performance is further improved. Can be achieved.

  Further, in the vibration damping device 10 having the above-described structure, the dimensions of the gaps 30, 36, 36 (particularly the gap 30 in the vibration input direction) due to the dimensional error in manufacturing the independent mass member 14 and the housing 12. Can be substantially eliminated by interposing the powder 38 in the gaps 30, 36, 36 (especially the gap 30 in the vibration input direction). 12. As a result, the industrial productivity of the vibration damping device 10 can be advantageously ensured. In addition, the substantial size of the gaps 30, 36, and 36 can be changed after the independent mass member 14 and the housing 12 are manufactured without performing post-processing such as cutting on the housing 12. Therefore, it is possible to ensure that the desired vibration control effect is stably exhibited.

  Furthermore, in the present embodiment, since the independent mass member 14 is positively jumped and displaced using the elasticity of the contact rubber film 26, the independent mass member 14 strikes the housing 12. It is possible to advantageously secure an impact force based on the above, and as a result, it is possible to improve the vibration damping performance.

  In particular, in the present embodiment, the mass of the mass metal fitting 24, the spring constant of the contact rubber film 26, etc. are appropriately set so that the independent mass member 14 is greatly jumped and displaced in a specific frequency range using the resonance characteristics. Therefore, it is possible to further improve the vibration damping performance in the specific frequency range.

  Therefore, in the present embodiment, the bias to the specific frequency range of the vibration suppression effect improved by positively jumping and displacing the independent mass member 14 is broadened by improving the damping performance as described above. As a result, the vibration suppression effect improved by actively jumping and displacing the independent mass member 14 is not limited to vibrations in a specific narrow frequency range, but a plurality or a wide range. It is possible to effectively exhibit vibrations in the frequency range.

  Further, in this embodiment, when the independent mass member 14 hits the housing 12, the gaps 30, 36, 36 between the surfaces 28, 32, 32 of the independent mass member 14 and the inner surfaces 22, 34, 34 of the housing 12. The independent mass member 14 is slid along the inner surface of the housing 12 by the powder 38 interposed between the inner surface 22 and the surface 28, 32, 32 of the independent mass member 14 and the inner surface 22, 34, 34 of the housing 12. It is also possible to increase the friction caused by the above.

  Furthermore, in this embodiment, the powder 38 is always interposed in the gaps 30, 36, 36 between the surfaces 28, 32, 32 of the independent mass member 14 and the inner surfaces 22, 34, 34 of the housing 12. Therefore, it can be advantageously maintained that the independent mass member 14 strikes the housing 12 via the powder 38. As a result, the desired damping effect can be stably exhibited.

  In the present embodiment, the cross-sectional shape of the independent mass member 14 in the vibration input direction of the surfaces 28, 32, and 32 and the cross-sectional shape of the inner surfaces 22, 34, and 34 of the housing 12 in the vibration input direction are similar. Therefore, it is possible to secure a large contact surface of the independent mass member 14 against the housing 12. As a result, when the independent mass member 14 strikes the housing 12, it is possible to generate friction due to contact in a wider range, and to generate greater internal friction (damping) in the contact rubber film 26. It becomes possible. In addition, since the amount of the powder 38 to which the impact based on the contact of the independent mass member 14 with the housing 12 is increased, the friction between the powders 38 can be further increased.

  Therefore, in the vibration damping device 10 of the present embodiment, it is possible to generate a larger friction when the independent mass member 14 strikes the housing 12, and as a result, the damping performance can be further improved. It becomes possible.

  In particular, in the present embodiment, the cross-sectional shape in the vibration input direction of the surfaces 28, 32, and 32 of the independent mass member 14 and the cross-sectional shape in the vibration input direction of the inner surfaces 22, 34, and 34 of the housing 12 are both circular. Therefore, when the independent mass member 14 strikes the housing 12, the contact rubber film 26 is positively sheared and the vibrational energy absorption effect associated with the shear deformation is more efficiently exhibited. It becomes possible.

  Further, since the cross-sectional shape of the independent mass member 14 in the vibration input direction is circular, the independent mass member 14 rotates around the central axis in the housing 12 and the independent mass member 14 strikes the housing 12. The part and the contact part of the independent mass member 14 with respect to the housing 12 in a state where no vibration is input are appropriately changed in the circumferential direction. As a result, the durability of the independent mass member 14 can be ensured, and a stable damping effect can be exhibited over a long period of time.

  Furthermore, in this embodiment, since the particle size of the powder 38 is 10 μm to 100 μm, the friction generated between the powders 38 when the independent mass member 14 strikes the housing 12 is advantageously ensured. This makes it possible to advantageously realize an improvement in damping performance.

  Furthermore, in this embodiment, the size of the gap 30 in the vibration input direction is set to 0.1 mm to 0.5 mm in a state where the independent mass member 14 is brought close to one moving end with respect to the housing 12. In addition, it is possible to advantageously secure the friction generated between the powders 38 when the independent mass member 14 strikes the housing 12, thereby making it possible to advantageously realize an improvement in damping performance.

  In addition, the independent mass member 14 and the housing 12 can be manufactured in consideration of manufacturing dimensional errors, and thereby the industrial mass of the independent mass member 14 and the housing 12 and the vibration damping device 10 can be increased. Can be advantageously secured.

  Furthermore, in this embodiment, since the independent mass member 14 with the powder 38 attached to the surfaces 28, 32, 32 is inserted into the housing body 16, the powder 38 functions as a slip agent. By fulfilling this, it is possible to advantageously realize the interpolating operation of the independent mass member 14 into the housing body 16.

  Incidentally, the vibration damping device 10 having the structure according to the present embodiment as described above is attached to the vibration member, the vibration member is subjected to frequency sweep excitation, and the resonance characteristic of the vibration damping device 10 is measured by frequency analysis. An example is shown in FIGS. Therefore, in the vibration damping device 10 used for this measurement, the cylindrical outer peripheral surface 28 of the independent mass member 14 and the cylindrical inner surface of the housing 12 in a state where the independent mass member 14 and the housing 12 are positioned on the same central axis. The dimension 30 of the gap 30 with respect to the peripheral surface 22 is set to 0.1 mm. Further, as the powder 38, a thin powder is employed, and the particle size thereof is about 30 μm. Further, the independent mass member 14 is rolled around the central axis on the powder 38 to adhere the powder 38 to the surface 28 of the independent mass member 14, and the independent mass member 14 having the powder 38 adhered to the surface 28 is removed. The independent mass member is formed by inserting the other opening portion of the housing body 16 into the housing body 16 covered with the lid body 18 from one opening portion and then covering the other opening portion of the housing body 16 with the lid body 18. 14 was accommodated in the housing 12. Furthermore, the jumping displacement of the independent mass member 14 relative to the housing 12 is allowed with the powder 38 interposed in the gap 30. In the vibration damping device as a comparative example including the same housing 12 and independent mass member 14 as the vibration damping device 10 of the present embodiment, a structure in which the powder 38 is not interposed in the gaps 30, 36, 36 ( The same measurement was performed for the comparative example, and the results are also shown in FIGS. 4 and 5.

As is clear from the measurement results shown in FIG. 4, the vibration damping device 10 having the structure according to the present embodiment has a larger resonance magnification in a wider frequency range than the vibration damping device having the conventional structure. . Further, when the loss factor is calculated for each of the vibration damping device 10 having the structure according to the present embodiment and the vibration damping device having the conventional structure from the measurement result shown in FIG. 4, the vibration damping device having the conventional structure is 0. .9, but the vibration damping device 10 of the present embodiment was 1.2. In the loss factor, the frequency at the peak value of the resonance magnification is f _0, and the frequency on the low frequency side of the frequency indicating a value 3 dB below the peak value is f ₁ , while the frequency on the high frequency side is f ₂ And calculated by the following formula.

(F ₂ −f ₁ ) / f ₀

  Further, as is clear from the measurement results shown in FIG. 5, the vibration damping device 10 having the structure according to the present embodiment has a graph slope (phase slope with respect to frequency) as compared with the vibration damping device of the conventional structure. ) Is loose, it can be seen that resonance occurs over a wide frequency range.

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

  For example, a housing in which a housing space extending in the longitudinal direction with a rectangular cross section is formed is used, and the housing space of the housing is independent and extends in the longitudinal direction with a rectangular cross section that is slightly smaller than the rectangular cross section of the housing space. A mass member may be accommodated.

  It is also possible to form the powder from an elastic material. In this case, when the independent mass member strikes the housing, the powder itself is elastically deformed, so that not only friction due to contact between the powders but also internal friction (attenuation) of the powder itself can occur. As a result, the damping performance can be further improved.

  Furthermore, the gap may be filled with powder, and the gap may be substantially eliminated. That is, although the space exists between the particles, the independent mass member and the housing may be continuously provided in the radial direction through the powder over the entire circumference. Even in such a case, if a vibration having an acceleration of a certain level or more is input, the contact rubber layer and / or the powder is elastically deformed, so that the independent mass member is substantially free from the housing. It will be repeatedly hit and separated. As a result, it is possible to obtain the same effect as in the above embodiment.

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

Sectional drawing which shows the damping device as one Embodiment of this invention. II-II sectional drawing of FIG. Explanatory drawing which shows the state which positioned the independent mass member and the housing on the same central axis. The graph which shows the relationship between resonance magnification and frequency. The graph which shows the relationship between a phase and frequency.

Explanation of symbols

10: damping device, 12: housing, 14: independent mass member, 22: cylindrical inner peripheral surface, 26: abutting rubber film, 28: cylindrical outer peripheral surface, 30: gap, 32: end surface in the axial direction, 34: Inner surface, 36: gap, 38: powder

Claims (5)

An independent mass member is accommodated and disposed in a non-adhering and displaceable manner with respect to a housing having a hollow sealed structure attached to a vibration member to be damped, and the surface of the independent mass member and the inner surface of the housing At least one of the contact rubber layers is formed, and when the vibration is input, the independent mass member jumps and displaces with respect to the housing, and elastically strikes the housing on both sides in the vibration input direction. In such a vibration control device,
A vibration damping device, wherein a powder smaller than the gap is interposed in a gap between the surface of the independent mass member and the inner surface of the housing.   The vibration damping device according to claim 1, wherein a cross-sectional shape of the surface of the independent mass member in the vibration input direction and a cross-sectional shape of the inner surface of the housing in the vibration input direction are similar to each other.   While the independent mass member has a cylindrical outer peripheral surface, the housing has a cylindrical inner peripheral surface, and when a vibration is input, the cylindrical outer peripheral surface of the independent mass member and the housing The vibration damping device according to claim 2, wherein the cylindrical inner peripheral surface abuts against the cylindrical inner peripheral surface.   The vibration damping device according to any one of claims 1 to 3, wherein a particle diameter of the powder is 10 to 100 µm.   The dimension of the said clearance gap in a vibration input direction is 0.1-0.5 mm in the state which brought the said independent mass member close to one moving end with respect to the said housing. The vibration control device described in 1.

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