JP2009127823A - Cylindrical dynamic damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel cylindrical dynamic damper capable of providing an excellent damping effect and easily installable on a rotating shaft. <P>SOLUTION: The large diameter side mass fixing parts 20 of a pair of cylindrical metallic springs 14, 14 each having a tapered cylindrical part 18 at the axial intermediate portion, respectively, are secured to a cylindrical mass member 12. The small diameter side rotating shaft fixing parts 22 are secured onto the rotating shaft 16. At least one slit 24 which extends from the mass fixing part 20 to the tapered cylindrical part 18 is circumferentially formed in each cylindrical metallic spring 14. The cylindrical dynamic damper includes a damping member 26 shear-deformed due to the displacement of the cylindrical mass member 12 in the right-angled direction to the axis thereof which is allowed by the elastic deformation of the pair of cylindrical metallic springs 14, 14. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  In the present invention, a cylindrical mass member is extrapolated to a rotation shaft as a main vibration system and elastically connected via an elastic member, thereby constituting a sub vibration system for the rotation shaft to be damped. The present invention relates to a cylindrical dynamic damper.

  2. Description of the Related Art Conventionally, a cylindrical dynamic damper (dynamic vibration absorber) is known as a type of vibration damping device that is attached to a rotating shaft such as a drive shaft or propeller shaft of an automobile to absorb and suppress the vibration. . In general, a cylindrical dynamic damper is configured such that a cylindrical damper mass is extrapolated at a predetermined distance to the outer peripheral side of a rotary shaft, and the damper mass is rotated by a rubber elastic body interposed between the damper mass and the rotary shaft. It is made into the structure elastically connected and supported by. For example, those disclosed in Patent Document 1 (Japanese Patent Publication No. 07-47979), Patent Document 2 (Japanese Patent Laid-Open No. 2000-199542), and the like.

  However, in the conventional cylindrical dynamic damper as described above, the temperature dependence and amplitude dependence of the rubber elastic body are high, and therefore the tuning frequency may change due to changes in the environment and input vibration. there were. In particular, dynamic dampers mounted on automobiles may be exposed to temperature changes of ± 50 ° C or higher depending on the environment, running conditions, internal combustion engine, etc. is there. As a result, there has been a problem that the required damping effect is difficult to be exhibited stably.

  In order to deal with such problems, for example, it may be possible to adopt a plurality of dynamic dampers that are tuned differently, but in order to employ a plurality of dynamic dampers to the extent that the required damping effect is satisfied. In addition to the increase in cost and weight, there are inherent problems such as time-consuming work for mounting on the rotating shaft.

Japanese Patent Publication No. 07-47979 JP 2000-199542 A

  Here, the present invention has been made in the background as described above, and the problem to be solved is that temperature dependency and amplitude dependency are reduced, and damping force can be effectively obtained. In addition, by improving the degree of freedom in tuning, it is possible to provide an excellent vibration damping effect, and to provide a cylindrical dynamic damper having a novel structure that facilitates mounting work on a rotating shaft. .

  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. Further, 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 an invention that can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized based on thought.

  That is, a feature of the present invention is that a cylindrical dynamic damper that is attached to the rotating shaft in an extrapolated state and suppresses vibration to be damped of the rotating shaft has a cylindrical shape having an inner diameter larger than the outer diameter of the rotating shaft. Using a mass member and a pair of cylindrical metal springs having a tapered cylindrical portion at an axially intermediate portion, the large-diameter side end of each cylindrical metal spring is fixed to the axial end of the cylindrical mass member. In addition to the mass fixing portion, the small-diameter side end of each cylindrical metal spring is used as a rotary shaft fixing portion that is externally fixed to the rotary shaft. And at least one slit extending to the circumference is provided, and a damping member is provided that is shear-deformed in accordance with the displacement in the direction perpendicular to the axis of the cylindrical mass member that is allowed based on the elastic deformation of the pair of cylindrical metal springs. It is in a cylindrical dynamic damper.

  In the cylindrical dynamic damper having the structure according to the present invention, the damping member is subjected to shear deformation when the cylindrical mass member is displaced in the direction perpendicular to the axis due to the main vibration input. Since the elasticity of the member due to compressive deformation is sufficiently reduced, the main spring characteristics are exhibited by the pair of cylindrical metal springs. Thereby, the spring action by the damping member is suppressed, and the adverse effect on the damping effect due to the relatively large temperature dependency and amplitude dependency of the damping member is reduced or avoided. Moreover, the target damping force can be sufficiently obtained by shear deformation of the damping member. That is, the secondary vibration system as one mass-spring system according to the present invention uses the spring system mainly using the spring component of the cylindrical metal spring and the damping component of the damping member, and the mass of the cylindrical mass member. It consists of a mass system. Therefore, a stable damping effect can be obtained with respect to the vibration to be damped.

  In particular, in the cylindrical dynamic damper according to the present invention, the slit extending from the small-diameter side end of the cylindrical metal spring to the tapered cylindrical portion is formed, thereby rotating the rotating shaft fixing portion composed of the small-diameter side end. When the outer fitting is fixed to the shaft, a large-diameter deformation of the rotating shaft fixing portion is greatly allowed. As a result, a cylindrical dynamic damper with a cylindrical metal spring can be mounted on the rotating shaft, and both the fixed stability and the ease of mounting can be achieved with the cylindrical metal spring. Can be done.

  Further, the spring characteristics can be tuned and changed by using a slit formed in the cylindrical metal spring. That is, the degree of freedom in tuning can be improved with a simple structure based on design changes such as the size, shape, number, and arrangement of slits.

  For the damping member, for example, rubber materials such as natural rubber, styrene / butadiene rubber, butyl rubber and urethane rubber, resin materials such as polystyrene, polyester, polyvinyl chloride and thermoplastic elastomer, mica and carbon black, etc. Various damping materials obtained by adding the above fillers are employed. Preferably, the damping member includes a high damping material such as a high damping rubber such as butyl rubber, a styrenic thermoplastic elastomer, and a polymer gel such as hydrogel or organogel.

  Further, in the cylindrical dynamic damper according to the present invention, the mass fixing portion of the cylindrical metal spring has a straight cylindrical shape, and the mass fixing portion is fitted and fixed to the end of the cylindrical mass member. A structure may be employed. Thereby, the fixing structure of the cylindrical metal spring and the cylindrical mass member is simplified, and the efficiency of the manufacturing operation can be further improved. In addition, for the fixing of the mass fixing portion to the cylindrical mass member, the mass fixing portion is externally fixed to the outer peripheral surface of the cylindrical mass member, or is fixed to the inner peripheral surface of the cylindrical mass member. Embodiments to be included.

  Further, in the cylindrical dynamic damper according to the present invention, a structure in which slits are formed unevenly on the circumference of the cylindrical metal spring in the cylindrical metal spring may be employed. Here, the slits are formed unevenly on the circumference of the cylindrical metal spring. In addition to the width, length, and shape of the plurality of slits, the intervals between the slits are different in the circumferential direction. And various other aspects. Thereby, in a cylindrical metal spring, mutually different spring characteristics can be imparted in different axis-perpendicular directions. As a result, a plurality of natural tuning frequencies in the direction perpendicular to the axis of the cylindrical dynamic damper can be set in different directions. In addition, since the dynamic damper rotates together with the rotating shaft, as a result, an effective vibration damping effect is exhibited in a wide frequency range as a whole by connecting a plurality of tuning frequency ranges.

  In the cylindrical dynamic damper according to the present invention, a structure in which the damping member is configured by fixing the damping material made of a polymer material so as to cover the surface of the cylindrical metal spring may be employed. . According to this, the space for forming the damping member in the dynamic damper is reduced, and compactness is achieved. Further, by protecting the cylindrical metal spring with the damping member, it is possible to improve the durability and corrosion resistance of the spring.

  In the cylindrical dynamic damper according to the present invention, the damping member is formed of a damping material made of a polymer material and has a tapered cylindrical shape, and is inserted into or inserted into the cylindrical metal spring. The end of the damping member is fixed to the axial end of the cylindrical mass member, while the end of the damping member is fixed to the cylindrical metal spring. A structure that is attached in close contact with the end portion on the small diameter side may be employed. According to such a structure, mutual interference between the elastic deformation of the cylindrical metal spring and the shear deformation of the damping member is suppressed in the portion where the cylindrical metal spring and the damping member are spaced apart in the direction perpendicular to the axis. This prevents the main spring characteristic based on the elastic deformation of the cylindrical metal spring and the complicated design change of the damping force based on the shear deformation of the damping member.

  Furthermore, in the above-described cylindrical dynamic damper according to the present invention, the damping member has a tapered cylindrical shape that covers the entire outer peripheral surface of the cylindrical metal spring, and has a structure in which the cylindrical metal spring is externally arranged. Are preferably employed. According to such a structure, since the tapered cylindrical damping member functions as a seal member for protecting the cylindrical metal spring, it is possible to improve durability, corrosion resistance, and the like of the cylindrical metal spring.

  In the cylindrical dynamic damper according to the present invention, a structure in which an annular seal that protrudes inward in the radial direction and extends in the circumferential direction is formed in the opening portion on the small diameter side of the pair of cylindrical metal springs. May be. According to such a structure, when the cylindrical dynamic damper is mounted on the rotating shaft, the sealing performance between the mounting surfaces is improved by the annular seal interposed between the mounting surfaces by being compressed and deformed. . Therefore, foreign matter such as water and oil can be prevented from entering the inside of the cylindrical dynamic damper, and desired characteristics can be advantageously ensured. Note that it is preferable that the annular seal is integrally formed with the damping member in consideration of the manufacturing cost and the reduction in the number of parts.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described. First, FIGS. 1 and 2 show an automobile dynamic damper 10 as a first embodiment according to a dynamic vibration absorber as a cylindrical dynamic damper of the present invention. The automotive dynamic damper 10 has a cylindrical shape as a whole, and a cylindrical mass member 12 as a cylindrical mass member is arranged at the axial central portion, and on both axial sides sandwiching the cylindrical mass member 12. A cylindrical leaf spring 14 as a cylindrical metal spring is provided. The automobile dynamic damper 10 according to the present embodiment is mounted on a circular rod-shaped drive shaft 16 as a rotating shaft that constitutes a front axle of an FF vehicle, a rear axle of an FR vehicle, a front and rear axle of a 4WD vehicle, and the like. (See FIG. 4). In the following description, the axial direction of the dynamic damper 10 and the drive shaft 16 refers to the left-right direction in FIGS.

  Specifically, the cylindrical mass metal fitting 12 has a thick cylindrical shape extending in an axial direction with a substantially constant circular cross section, and is formed of an iron-based metal material having a large specific gravity. The inner diameter dimension d1 of the cylindrical mass fitting 12 is larger than the maximum outer diameter dimension of the drive shaft 16.

  On the other hand, the cylindrical leaf spring 14 is an elastic member formed of a thin metal material such as spring steel and has a cylindrical shape as a whole. Here, an intermediate portion in the axial direction of the cylindrical leaf spring 14 is a tapered cylindrical portion 18 whose diameter dimension gradually decreases from one axial direction to the other. A large-diameter side end and a small-diameter side end of the tapered tubular portion 18 are a mass fixing portion 20 that extends straight in the axial direction and a shaft fixing portion 22 as a rotating shaft fixing portion. The tapered tubular portion 18, the mass fixing portion 20, and the shaft fixing portion 22 can be integrally formed by, for example, subjecting a straight cylindrical metal fitting to a diameter expansion process.

  Further, the shape, size, structure, etc. of the tapered tubular portion 18, the mass fixing portion 20, and the shaft fixing portion 22 are appropriately changed in design according to required spring characteristics, manufacturability, etc. The tapered cylindrical portion 18 is formed into a multi-stage tapered cylindrical shape having different taper angles in a plurality of stages in the axial direction, or a tapered cylindrical portion 18 having a curved longitudinal sectional shape in which the taper angle continuously changes in the axial direction as a whole. It is also possible. Furthermore, the inner diameter dimension of the mass fixing portion 20 is slightly larger than the outer diameter dimension of the cylindrical mass fitting 12, and the inner diameter dimension of the shaft fixing portion 22 is smaller than the inner diameter dimension d1 of the cylindrical mass fitting 12. Yes.

  Further, each cylindrical leaf spring 14 is formed with a plurality of slits 24. The slit 24 penetrates the inner and outer surfaces of the tubular leaf spring 14, extends in the axial direction from the opening-side end edge of the shaft fixing portion 22 toward the connection-side end with the tapered tubular portion 18, and is a tapered tube. From the small-diameter side edge connected to the shaft fixing portion 22 of the cylindrical portion 18 to the vicinity of the large-diameter side edge, it extends in the generatrix direction of the tapered cylindrical portion 18 and has a notch shape as a whole. The rear end portion of the slit 24 positioned near the large-diameter side end portion of the tapered tubular portion 18, that is, near the mass fixing portion 20 of the tubular leaf spring 14, is gradually narrowed to reduce the stress concentration. It is bent or curved in such a way that it protrudes toward the mass fixing portion 20 side. The slit 24 extending from the shaft fixing portion 22 to the tapered cylindrical portion 18 extends with a substantially constant width dimension over the whole, so that it is axially viewed in plan view as shown in FIG. Although extending straight, the width of the slit may be changed, or may be inclined or curved with respect to the axial direction of the tubular leaf spring 14 in plan view.

  By forming such a slit 24 in the cylindrical leaf spring 14, the cylindrical leaf spring 14 also adjusts its spring characteristics by adjusting the shape, size, number, arrangement, etc. of the slit 24. It is possible. Needless to say, the spring characteristics of the cylindrical leaf spring 14 can be adjusted by changing the taper angle in addition to the material and the member thickness.

  In particular, in the present embodiment, as shown in FIG. 3, four slits 24 as described above are formed in the tubular leaf spring 14, and the two slits 24 a and 24 b are formed on the tubular leaf spring 14. It is made to oppose in the XX direction which is a uniaxial perpendicular direction. Further, in the YY direction as another uniaxial perpendicular direction orthogonal to the XX direction of the tubular leaf spring 14, one slit 24c is positioned on one side across the central axis of the tubular leaf spring 14. In addition, one slit 24d is positioned so as to be biased toward the slit 24a from the other side across the central axis of the cylindrical leaf spring 14. Thereby, the separation distance between the circumferential direction of the slit 24c and the slit 24a: L1, the separation distance between the circumferential direction of the slit 24a and the slit 24d: L2, and the separation distance between the circumferential direction of the slit 24d and the slit 24b: L3 Are different from each other, and the separation distance L4 between the slits 24b and 24c in the circumferential direction is the same as the separation distance L1 between the slits 24c and 24a in the circumferential direction.

  That is, in the tubular leaf spring 14 according to the present embodiment, the slits 24 are formed unevenly on the circumference of the tubular leaf spring 14, and on the basis thereof, different spring characteristics are obtained in different directions perpendicular to the axis. Has been granted.

  Further, a damping rubber 26 as a damping member is disposed on the tapered tubular portion 18 and the shaft fixing portion 22 in the tubular leaf spring 14. The damping rubber 26 is vulcanized and bonded by vulcanization so as to cover the entire surface of the tapered tubular portion 18 and the shaft fixing portion 22 with a substantially constant thickness. Each slit 24 of the cylindrical leaf spring 14 is also filled with a damping rubber 26, and when the damping rubber 26 is vulcanized, the slit 24 is used to make the inside of the tapered cylindrical portion 18 and the shaft fixing portion 22. The damping rubber 26 fixed to the peripheral surface side and the damping rubber 26 fixed to the outer peripheral surface side are integrally formed. In short, in the present embodiment, the tubular leaf spring 14 is an integrally vulcanized molded product including the damping rubber 26. Further, the inner diameter dimension d2 of the cylindrical body covered with the damping rubber 26 of the shaft fixing portion 22 is the minimum inner diameter dimension of the integrally vulcanized molded product. Inner diameter dimension: smaller than d1.

  The size, shape, etc. of the damping rubber 26 are appropriately set according to the required vibration isolation characteristics and damping coefficient, and are not particularly limited. In addition to the known rubber material, the material of the damping rubber 26 also employs a gel-like resin material such as a styrenic thermoplastic elastomer that exhibits a damping force upon deformation like a rubber, or a polymer gel such as hydrogel or organogel. Is possible. Specifically, as the rubber material, high-damping butyl rubber or the like is suitable, and high-damping material compositions described in Japanese Patent No. 3675216 and Japanese Patent No. 3468073 are also suitable.

  Further, on the outer peripheral surface of the mass fixing portion 20 of the cylindrical leaf spring 14, the surface of the damping rubber 26, etc., on the slit 24 or on the axial extension line of the slit 24, as necessary, protrusions, markings, painting, etc. A marking process may be applied, so that the formation positions of the slits 24 in the tapered cylindrical portion 18 and the shaft fixing portion 22 covered with the damping rubber 26 can be recognized.

  The axial ends of the cylindrical mass fittings 12 are respectively press-fitted into the pair of mass fixing portions 20 of the cylindrical leaf spring 14 provided with such a damping rubber 26, or the mass fixing portion 20 is the cylindrical mass. A pair of cylindrical leaf springs 14 and 14 are externally fitted and fixed to the cylindrical mass metal fitting 12 by being inserted around the axial end portion of the metal fitting 12 and being fitted and fixed by diameter reduction. Along with this fixing, the cylindrical mass fitting 12 and each cylindrical leaf spring 14 are concentrically arranged, and the tapered cylindrical portion 18 and the shaft fixing portion covered with the damping rubber 26 of each cylindrical leaf spring 14. 22 is assembled to the cylindrical mass fitting 12 so as to protrude outward in the axial direction from both axial ends of the cylindrical mass fitting 12.

  In the present embodiment, four slits 24a, 24b, 24c, 24d formed in one cylindrical leaf spring 14 and four slits 24a, 24b, 24c, 24d formed in the other tubular leaf spring 14 include: A pair of cylindrical leaf springs 14 and 14 are assembled to the cylindrical mass fitting 12 so as to overlap each other in a position projected in the axial direction. That is, the XX direction and the YY direction of the pair of cylindrical leaf springs 14 and 14 are positioned so as to overlap each other in the axial direction.

  The automotive dynamic damper 10 having the above-described structure is mounted on a drive shaft 16 as shown in FIG. 4, for example.

  The drive shaft 16 is a long rod-shaped rigid member having a hollow or solid circular cross section, and splined connection portions 28 and 28 are formed at both axial end portions. A universal joint (not shown) is assembled to the pair of connecting portions 28, 28, and one connecting portion 28 is connected to the output shaft of the final reduction gear device through the universal joint, and the other connecting portion 28 is connected. Are connected to the drive wheels.

  Further, between the central portion of the drive shaft 16 in the axial direction and each connecting portion 28, large-diameter ring-shaped locking portions 30, 30 are protruded with a predetermined distance in the axial direction. A locking groove 32 is formed between the 30 axial directions. The locking groove 32 is for supporting the end portion of the protective cover when the protective cover is externally attached to the drive shaft 16 so as to cover each connecting portion 28 with a protective cover (not shown).

  The drive shaft 16 according to the present embodiment, except for the connecting portion 28 and the locking portion 30, extends in the axial direction with a substantially constant circular cross section, and its outer diameter dimension is a cylindrical mass of the automotive dynamic damper 10. The inner diameter dimension of the metal fitting 12 is smaller than d1, and is equal to or slightly larger than the inner diameter dimension d2 of the shaft fixing portion 22 including the damping rubber 26 on both axial sides of the dynamic damper 10. The maximum outer diameter dimension of the drive shaft 16 is the outer diameter dimension d3 of the locking portion 30 and is smaller than the inner diameter dimension d1 of the cylindrical mass fitting 12, while the damping rubber 26 is provided. Further, the inner diameter dimension of the shaft fixing portion 22 is larger than d2. The outer diameter dimension of the locking part 30: d3 and the outer diameter dimension of the connecting part 28 are substantially the same.

  In order to mount the automotive dynamic damper 10 on the drive shaft 16 as described above, the dynamic damper 10 is extrapolated from any one of the connecting portions 28 on both sides of the drive shaft 16 in the axial direction, and the one connecting portion 28 and the pair of the paired The engaging portions 30 and 30 are moved in the axial direction, and are positioned at a target mounting position of the drive shaft 16 (in the present embodiment, a substantially axial center portion of the drive shaft 16). In this case, since the inner diameter dimension d2 of the shaft fixing portion 22 having the damping rubber 26 of the dynamic damper 10 is smaller than the outer diameter dimension d3 of the connecting portion 28 and the locking portion 30, the dynamic damper 10 is connected. The dynamic damper 10 can be easily externally attached to the drive shaft 16 by elastically deforming it so as to push it in the diameter-expanding direction when it is inserted in the axial direction beyond the portion 28 or the locking portion 30. Is possible. Thus, with the dynamic damper 10 positioned at the target mounting position of the drive shaft 16, the damping is based on the elasticity of the cylindrical leaf spring 14 and the elasticity of the damping rubber 26 attached to the shaft fixing portion 22. The inner peripheral surface of the rubber 26 is overlapped with the outer peripheral surface of the drive shaft 16 in close contact with each other, and the pair of shaft fixing portions 22 and 22 of the dynamic damper 10 are externally fixed to the drive shaft 16. In particular, the inner diameter dimension d2 of the shaft fixing portion 22 provided with the damping rubber 26 of the dynamic damper 10 before being attached to the drive shaft 16 is d2 ≦ in relation to the inner diameter dimension d2 ′ of the shaft fixing portion 22 after being attached. The outer diameter dimension of the drive shaft 16 is set to be larger than the inner diameter dimension d2 of the shaft fixing portion 22 in consideration of d2 ′. The fitting / fixing force of the dynamic damper 10 to the drive shaft 16 can be adjusted according to the value of d2'-d2.

  When the automobile dynamic damper 10 is mounted on the drive shaft 16 in this manner, the damper 10 and the drive shaft 16 are positioned substantially concentrically, and the tapered tubular portion 18 of the tubular leaf spring 14 is the small diameter side end portion. Gradually increases outward in the radial direction of the drive shaft 16 toward the end portion on the large diameter side. In addition, the cylindrical mass fitting 12 fixed to the mass fixing portion 20 on the large diameter side of the tapered cylindrical portion 18 is extrapolated around the drive shaft 16 at a predetermined distance.

  Thereby, the cylindrical mass metal fitting 12 is elastically supported with respect to the drive shaft 16 to which the shaft fixing portions 22 and 22 are fixed via the pair of tapered cylindrical portions 18 to which the damping rubber 26 is attached. ing. Based on the elastic deformation of the damping rubber 26 and the tapered cylindrical portion 18, the cylindrical mass fitting 12 is allowed to be displaced relative to the drive shaft 16.

  That is, the tapered cylindrical portion 18 that elastically supports the cylindrical mass fitting 12 has an axial cross-section inclined with respect to the axial direction of the dynamic damper 10 and the drive shaft 16, and a slit 24 is formed. Therefore, when the cylindrical mass fitting 12 is displaced in the direction perpendicular to the axis with respect to the drive shaft 16, the tapered cylindrical portion 18 can exhibit spring characteristics due to elastic deformation. In addition, along with the elastic deformation of the tapered cylindrical portion 18, the damping rubber 26 is subjected to shear deformation.

  In particular, the separation distance between the circumferential directions of the slits 24 in the four slits 24 a, 24 b, 24 c, 24 d formed in the cylindrical leaf spring 14 is appropriately changed, so that the slit 24 is arranged around the cylindrical leaf spring 14. Due to the uneven formation above, when the cylindrical mass fitting 12 is displaced in the direction perpendicular to the axis with respect to the drive shaft 16 during vibration such as bending resonance of the drive shaft 16, the directions perpendicular to each other are different from each other. The spring characteristics different from each other can be exhibited.

  Therefore, when the bending vibration of the drive shaft 16 to be damped is exerted on the dynamic damper 10 with the dynamic damper 10 mounted as described above, the displacement of the cylindrical mass fitting 12 with respect to the drive shaft 16 is a cylinder that is a metal spring. The leaf springs 14 and 14 are allowed with a large damping effect and a large damping effect. In other words, the cylindrical mass fitting 12 is displaced by vibration in response to the input of vibration to be damped. The vibration displacement of the cylindrical mass fitting 12 is caused by the tapered tubular portion 18 of the tubular leaf spring portion 14. This is expressed by a vibration system composed of one mass-spring system in which the elasticity of the above is a spring and the mass of the cylindrical mass fitting 12 is a mass. In short, this one vibration system functions as a sub-vibration system with respect to the drive shaft 16 as the rotation shaft, which is the main vibration system, and thereby exhibits a vibration reduction effect that is a dynamic damper effect.

  Moreover, in such a sub-vibration system, when the tapered cylindrical portion 18 is deformed, the main deformation mode of the damping rubber 26 is shear deformation, and a large damping force is exhibited while suppressing a large spring rigidity due to compression deformation. It becomes. Therefore, in addition to the spring characteristic of the tapered cylindrical portion 18 which is a metal spring, a large damping force by the damping rubber 26 is also exerted. As a result, regarding the dynamic damper effect by such a secondary vibration system, the vibration peak The reduction effect is exhibited. In short, not only the peak vibration due to the resonance of the vibration member, which has been a problem prior to the mounting of the dynamic damper 10, but also new peak vibrations that occur in the upper and lower frequency ranges of the initial peak vibration due to the dynamic damper effect. As a result, an effective vibration reduction effect is achieved in a wide frequency range as a whole.

  In addition, since the cylindrical leaf spring 14 that constitutes the sub-vibration system spring is constituted by a metal spring, the amplitude of the tuning frequency is larger than that of a dynamic damper in which a conventional spring is constituted by a rubber elastic body. The dependence and temperature dependence are greatly suppressed. As a result, a large amplitude change appears in the vibration to be damped by being exposed to a temperature change of 50 ° C. or higher, for example, in an automobile, or by changing the magnitude of the input vibration to several tens of times depending on the driving conditions. Even in such an environment, the change in the tuning frequency of the dynamic damper 10 is suppressed, and the intended damping effect can be stably obtained.

  Further, in the automotive dynamic damper 10 according to the present embodiment, the axial end of the dynamic damper 10 is securely attached to the drive shaft 16 by utilizing the elastic deformation action of the shaft fixing portion 22 made of a metal material such as spring steel. The outer fitting is fixed. As a result, for example, a cylindrical dynamic damper having a conventional structure shown in Patent Document 1 (Japanese Patent Publication No. 07-47979) and Patent Document 2 (Japanese Patent Application Laid-Open No. 2000-199542) has a damper mounted on the drive shaft. There is no need to fix and fix the fixing band from the outer peripheral side of the fitting fixing portion. In addition, in this embodiment, the shaft fixing portion 22 is integrally formed with the tapered cylindrical portion 18 and the mass fixing portion 20. Therefore, it is possible to effectively reduce the number of parts and simplify the mounting operation on the drive shaft 16.

  Here, a slit 24 extending from the opening edge of the shaft fixing portion 22 in the tubular leaf spring 14 to the vicinity of the large-diameter side end portion of the tapered tubular portion 18 is separated in the circumferential direction of the tubular leaf spring 14. By forming the plurality, a large amount of diameter expansion deformation of the cylindrical leaf spring 14 is ensured. Thereby, also in the dynamic damper 10 provided with the metal cylindrical leaf | plate spring 14, extrapolation mounting | wearing from the axial direction edge part of the drive shaft 16 like illustration using the diameter expansion deformation of the cylindrical leaf | plate spring 14 is carried out. Therefore, simplification of the mounting work can be achieved.

  Further, the tuning frequency setting can be changed with a simple structure based on the design change such as the size, shape, number, and arrangement of the slits 24 formed in the cylindrical leaf spring 14.

  In particular, in the present embodiment, the plurality of slits 24 are formed unevenly on the circumference of the cylindrical leaf spring 14, so that the cylindrical leaf spring 14 has mutually different axis-perpendicular directions (more precisely, the shaft fixing portion 22. Can be provided with different spring characteristics in the deformation direction in which the mass fixing portion 20 is swung and displaced in the direction perpendicular to the axis. Therefore, a plurality of natural tuning frequencies in the bending direction of the automotive dynamic damper 10 can be set in different bending directions. Here, since the dynamic damper 10 rotates together with the drive shaft 16, the vibration damping effect can be effectively exhibited in a wide frequency range in which a plurality of tuning frequency ranges are connected and broadened as a whole.

  Specifically, a test for confirming the vibration damping effect as described above was conducted. The result is shown in FIG. In Example 1 shown by the one-dot chain line in FIG. 5, the result of measuring the vibration level when the dynamic damper 10 for an automobile of the present embodiment is assembled to a test member equivalent to the drive shaft 16 and the test member is vibrated. It is. Further, in Example 2 indicated by a solid line in FIG. 5, a plurality of slits are formed uniformly on the circumference of the cylindrical leaf spring of the dynamic damper for automobile according to the present embodiment, thereby achieving a single frequency. It is the result of having measured the vibration level of the test member on the same test conditions as Example 1 about the dynamic damper for vehicles which is made into the structure according to the present invention and which was tuned. Moreover, the comparative example shown by the broken line in FIG. 5 is the result of measuring the vibration level of the test member in the same test state as in Examples 1 and 2 without attaching the damper to the test member.

  From the results shown in FIG. 5 as well, in the automotive dynamics according to the first and second embodiments having the structure according to the present invention, the damping effect is effective in the frequency range of the peak vibration, which is a problem of the drive shaft. It is recognized that

  In particular, in the automotive dynamic damper 10 of the first embodiment, a line connecting two newly generated peak vibrations in both the upper and lower frequency ranges of the initial peak vibration frequency range which is a problem due to the dynamic damper effect. It can be seen that the measurement result of the shape is a gentle shape as compared with that of the dynamic damper effect of the second embodiment. From this, it is considered that the slits 24 are formed unevenly on the circumference of the tubular leaf spring 14, so that a plurality of natural frequencies exist and a broad characteristic is realized as a whole.

  Further, in the present embodiment, the damping rubber 26 is vulcanized and bonded so as to cover the surface of the cylindrical leaf spring 14, whereby the tubular leaf spring 14 is formed as an integrally vulcanized molded product including the damping rubber 26. This reduces the number of parts and simplifies the work of assembling the cylindrical leaf spring 14 and the damping rubber 26.

  In addition, the damping rubber 26 is fixed to the surface of the shaft fixing portion 22 of the cylindrical leaf spring 14 and is sandwiched between the shaft fixing portion 22 and the drive shaft 16 when mounted on the drive shaft 16. The rubber 26 functions as a seal member. Therefore, the sealing performance between the mounting surface of the dynamic damper 10 and the drive shaft 16 can be improved with a simple structure.

  In addition, a combination structure of dynamic damper constituent members composed of a plurality of sets each including a plurality of types of cylindrical mass fittings 12 having different masses and a plurality of types of cylindrical leaf springs 14 and 14 having different spring characteristics. It is also possible to manufacture the dynamic damper 10 as illustrated in the body.

  That is, the cylindrical mass fitting 12 having a predetermined mass is selected and adopted from a plurality of types of mass fittings, and the cylindrical leaf spring 14 having a predetermined spring characteristic is selected from the plurality of types of cylindrical leaf springs having a spring characteristic. And adopt. Then, by combining each of the selected cylindrical mass fittings 12 and the cylindrical leaf spring 14, a secondary vibration system having a target tuning frequency can be realized. According to this, it is possible to quickly and efficiently provide a plurality of types of dynamic dampers 10 having different tuning frequencies upon request.

  Furthermore, in the automotive dynamic damper 10 having the above-described structure, the natural tuning frequency is adjusted as in the dynamic damper 34 according to the second embodiment of the present invention shown in FIGS. Is also possible. In addition, in the following description, about the member and site | part made into the substantially same structure as the said embodiment, the same code | symbol as the said embodiment is attached | subjected, and those detailed description is abbreviate | omitted.

  That is, in the dynamic damper 34, the inner diameter dimension d3 of the cylindrical mass fitting 36 having a cylindrical shape as the cylindrical mass member is slightly larger than the outer diameter dimension of the mass fixing portion 20 of the cylindrical leaf spring 14. Has been.

  The mass fixing portion 20 of each cylindrical leaf spring 14 is press-fitted and fixed to the opening side end portion of the cylindrical mass fitting 36, so that the tubular leaf spring 14 is inserted into the cylindrical mass fitting 36 in an inserted state. It is fitted and fixed.

  By adopting such a large-diameter cylindrical mass metal fitting 36, the circumferential length and outer diameter of the cylindrical mass metal fitting can be secured large, and the mass mass of the mass-spring system can be further increased. Become.

  In the first embodiment and the second embodiment, the cylindrical leaf spring 14 and the damping rubber 26 are integrally formed. However, they may be formed separately from each other.

  Specifically, as in the third embodiment of the present invention shown in FIGS. 8 and 9, damping rubbers 38 as damping members may be provided on both sides in the axial direction of the cylindrical mass fitting 12, respectively. .

  The damping rubber 38 as a whole has a cylindrical shape having a smaller diameter than the cylindrical leaf spring 14 and is made of a damping material made of a polymer material. In addition, one side in the axial direction of the damping rubber 38 is a cylindrical rubber portion 40 extending in a substantially constant circular cross section in the axial direction, and the other end in the axial direction is connected to the cylindrical rubber portion 40. The tapered rubber portion 42 has a diameter that gradually increases from the first side toward the other side in the axial direction. The degree of taper of the tapered rubber part 42 is made smaller than the degree of taper of the tapered tubular part 18 of the tubular leaf spring 14.

  Further, a stopper portion 44 extending in a circumferential direction with a substantially constant cross section is provided on the outer peripheral surface of the opening end portion of the cylindrical rubber portion 40 so as to protrude radially outward, and is integrally formed with the damping rubber 38. Yes. Here, the outer diameter of the cylindrical rubber portion 40 is substantially the same as the inner diameter of the shaft fixing portion 22 of the cylindrical leaf spring 14, and the outer diameter of the stopper portion 44 is equal to that of the shaft fixing portion 22. It is larger than the outer diameter.

  Further, on the inner peripheral surface of the opening end portion of the cylindrical rubber portion 40 of the damping rubber 38, a seal lip 46 extending in a circumferential direction as an annular seal with a substantially constant cross section protrudes radially inward. The damping rubber 38 is integrally formed. The stopper portion 44 and the seal lip 46 may extend continuously over the entire circumference in the circumferential direction, or may extend at a distance less than one circumference in the circumferential direction, or may be formed in a plurality spaced apart in the circumferential direction. Is possible. Further, the seal lip 46 is provided on the end side connected to the inner peripheral surface of the intermediate portion in the axial direction or the tapered rubber portion 42 instead of or in addition to the inner peripheral surface on the opening end side of the cylindrical rubber portion 40. You may form in an internal peripheral surface.

  The end on the large diameter side of each tapered rubber portion 42 is an end face (portion) on the radially inner side from the central portion in the thickness direction at the axial end of the cylindrical mass fitting 12 or the inside of the cylindrical mass fitting 12. It is vulcanized and bonded to the peripheral surface. That is, in this embodiment, the pair of damping rubbers 38 are integrally vulcanized with the cylindrical mass fitting 12 instead of the cylindrical leaf spring 14.

  In the integrally vulcanized molded product of the cylindrical mass metal fitting 12 provided with such a damping rubber 38, each cylindrical leaf spring 14 is extrapolated from both sides in the axial direction, and is attached to the mass fixing portion 20 of the cylindrical leaf spring 14. On the other hand, the axial end of the cylindrical mass fitting 12 is press-fitted and fixed. In addition, the cylindrical rubber portion 40 and the stopper portion 44 of the damping rubber 38 are deformed in a radially inward direction, or instead of or in addition thereto, the slit 24 of the tubular leaf spring 14 is used to fix the shaft. The shaft fixing portion 22 straddles the stopper portion 44 of the damping rubber 38 in the axial direction in a state in which the diameter of the portion 22 is expanded, and the shaft plate 14 or the damping rubber 38 is released from the deformation, thereby releasing the shaft. The inner peripheral surface of the fixed portion 22 and the outer peripheral surface of the cylindrical rubber portion 40 are overlapped with each other in a close contact state over substantially the whole. Further, the axial end portion of the shaft fixing portion 22 is abutted against the stopper portion 44 of the damping rubber 38 in the axial direction.

  As a result, the damping rubber 38 is inserted into the tubular leaf spring 14, and the tapered rubber portion 42 of the damping rubber 38 is separated from the tapered tubular portion 18 of the tubular leaf spring 14 by a predetermined distance in the direction perpendicular to the axis. Arranged. In this way, the damping rubber 38 and the tubular leaf spring 14 are formed separately from each other, and the tapered rubber portion 42 and the tapered tubular portion 18 that are mainly deformed by vibration input in the damping rubber 38 and the tubular leaf spring 14 are separated from each other. By arranging, interference with elastic deformation of each other can be suppressed.

  Further, when mounting on the drive shaft 16, the damping rubber 38 and the cylindrical leaf spring 14 are expanded and deformed while being extrapolated to the drive shaft 16, and the deformation is released, thereby removing the cylinder of the damping rubber 38. The shaft fixing portion 22 of the tubular leaf spring 14 is superposed on the drive shaft 16 via the rubber portion 40. The seal lip 46 formed integrally with the damping rubber 38 is interposed between the shaft fixing portion 22 and the drive shaft 16 via the damping rubber 38 while being compressed and deformed. And the mounting surface of the drive shaft 16 can be improved with a simple structure.

  Alternatively, as in the fourth embodiment of the present invention shown in FIGS. 10 and 11, the tubular leaf spring 14 is fitted and fixed inside the tubular mass metal fitting 12, and more than the tubular leaf spring 14. A damping rubber 50 as a damping member having a large-diameter tapered rubber portion 48 may be arranged on the tubular leaf spring 14 so as to cover substantially the entire outer peripheral surface of the tubular leaf spring 14. .

  That is, the mass fixing portion 20 of each cylindrical leaf spring 14 is press-fitted and fixed to the fitting groove 52 formed on the inner peripheral surface of the axial end portion of the cylindrical mass metal fitting 12.

  Further, the small-diameter side end and the large-diameter side end of the tapered rubber portion 48 of the damping rubber 50 are respectively a small-diameter rubber portion 54 and a large-diameter rubber portion 56 that extend in a substantially constant circular cross section in the axial direction. Further, the stopper portion 44 of the damping rubber 50 according to the present embodiment protrudes from the inner peripheral surface of the opening end portion of the large-diameter rubber portion 56, and the seal lip 46 of the damping rubber 50 is provided on the stopper portion 44. It protrudes from the protruding tip surface. Further, the degree of taper of the tapered rubber part 48 is made larger than the degree of taper of the tapered tubular part 18 of the tubular leaf spring 14.

  In the assembled body in which the mass fixing portion 20 of the cylindrical leaf spring 14 is fitted and fixed to the cylindrical mass fitting 12, each damping rubber 50 is extrapolated from both sides in the axial direction, and the tapered rubber portion in the damping rubber 50 is provided. A small-diameter side end 48 or a small-diameter rubber portion 54 is externally fitted and fixed to the shaft fixing portion 22 of the cylindrical leaf spring 14, and an axial end portion of the shaft fixing portion 22 is a stopper portion 44 of the damping rubber 50. The insertion end of the damping rubber 50 with respect to the cylindrical leaf spring 14 is defined by being abutted in the axial direction. Further, the seal lip 46 protrudes radially inward from the inner peripheral surface of the shaft fixing portion 22. Further, the inner peripheral surface of the large-diameter rubber portion 56 of the damping rubber 50 is overlaid on the outer peripheral surface of the axial end portion of the cylindrical mass metal fitting 12, and these overlapping surfaces are mutually attached using an adhesive or the like. It is fixed.

  Thereby, the damping rubber 50 is arranged on the tubular leaf spring 14 so as to cover the entire outer peripheral surface of the tubular leaf spring 14, and the tapered rubber portion 48 of the damping rubber 50 is covered with the tubular leaf spring 14. The taper cylindrical portion 18 is arranged at a predetermined distance in the direction perpendicular to the axis. As described above, the entire outer peripheral surface of the cylindrical leaf spring 14 is covered with the damping rubber 50, so that the damping rubber 50 functions as a sealing member for the tubular leaf spring 14. As a result, the durability of the tubular leaf spring 14 is improved. Improvement is achieved.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the specific descriptions in these embodiments, and various changes, modifications, and improvements based on the knowledge of those skilled in the art. Needless to say, any of these embodiments can be included in the scope of the present invention without departing from the spirit of the present invention.

  For example, the shape, size, structure, number, arrangement, and the like of the tapered cylindrical portion 18, the mass fixing portion 20, the shaft fixing portion 22, and the slit 24 in the cylindrical leaf spring 14 can be arbitrarily set. More specifically, in the first to fourth embodiments, the mass fixing part 20 and the shaft fixing part 22 may have a tapered cylindrical shape.

  Further, in the second embodiment in which the pair of cylindrical leaf springs 14 and 14 are inserted and arranged at both axial ends of the cylindrical mass metal fitting 12, the mass fixing portions 20 of the cylindrical leaf springs 14 are integrated with each other. A pair of cylindrical leaf springs 14 and 14 may be integrally formed with each other by forming one cylindrical body.

  Furthermore, another member or part may be provided between the tapered cylindrical portion and the mass fixing portion or between the tapered cylindrical portion and the shaft fixing portion in the cylindrical leaf spring.

  Further, in the above embodiment, the slits 24 formed in each cylindrical leaf spring 14 are all of the same standard having the same shape, size, etc. Of course it is possible.

  Further, a metal or resin fastening band that is fastened and fixed to the outer peripheral side of the mass fixing portion may be provided as necessary.

  In the third embodiment and the fourth embodiment, the damping rubber may be vulcanized and bonded to the cylindrical mass fitting. Furthermore, a covering rubber layer that covers the inner and outer peripheral surfaces of the cylindrical mass fitting or the entire surface of the cylindrical mass fitting may be formed integrally with the damping rubber.

  Further, in the first and second embodiments in which the damping rubber is fixed to the outer peripheral surface of the tubular leaf spring, for example, the axial end of the tubular mass fitting inside the tapered tubular portion of the tubular leaf spring; It is possible to obtain a greater damping force by providing a damping rubber that causes shear deformation in accordance with the displacement of the cylindrical mass fitting with respect to the mass fixing portion between the axial ends of the small-diameter side ends of the cylindrical leaf spring. Become.

  In addition, in the said embodiment, although the specific example of what applied this invention to the dynamic damper for drive shafts of a motor vehicle was demonstrated, this invention is mounted | worn with various rotating shafts other than a motor vehicle besides the propeller shaft of a motor vehicle. The present invention can also be applied to a cylindrical dynamic damper.

The top view of the dynamic damper for motor vehicles as a first embodiment of the present invention. II-II sectional drawing of FIG. The front view of the cylindrical leaf | plate spring which comprises the dynamic damper for motor vehicles of FIG. The longitudinal cross-sectional view which shows the state which mounted | wore the drive shaft with the dynamic damper for motor vehicles of FIG. The graph which shows the result of the test done in order to confirm the damping effect of the cylindrical dynamic damper which concerns on this invention. The top view of the dynamic damper for motor vehicles as 2nd embodiment of this invention. VII-VII sectional drawing of FIG. The top view of the dynamic damper for motor vehicles as 3rd embodiment of this invention. IX-IX sectional drawing of FIG. The top view of the dynamic damper for motor vehicles as 4th embodiment of this invention. XI-XI sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Dynamic damper for motor vehicles, 12: Cylindrical mass metal fitting, 14: Cylindrical leaf spring, 16: Drive shaft, 18: Tapered cylindrical part, 20: Mass fixing part, 22: Shaft fixing part, 24: Slit, 26 : Damping rubber

Claims (7)

In the cylindrical dynamic damper that is attached to the rotating shaft in an extrapolated state and suppresses vibration to be damped of the rotating shaft,
Using a cylindrical mass member having an inner diameter larger than the outer diameter of the rotating shaft and a pair of cylindrical metal springs having a tapered cylindrical portion at an axially intermediate portion, a large-diameter side end of each cylindrical metal spring The portion is a mass fixing portion that is fixed to the end portion in the axial direction of the cylindrical mass member, and the small-diameter side end portion of each cylindrical metal spring is a rotation shaft fixing portion that is externally fixed to the rotation shaft. On the other hand, in each cylindrical metal spring, at least one slit extending from the end on the small diameter side to the tapered cylindrical portion is formed on the circumference, and allowed based on elastic deformation of the pair of cylindrical metal springs. A cylindrical dynamic damper comprising a damping member that is sheared and deformed in accordance with a displacement in a direction perpendicular to the axis of the cylindrical mass member.   The cylindrical shape according to claim 1, wherein the mass fixing portion of the cylindrical metal spring has a straight cylindrical shape, and the mass fixing portion is fitted and fixed to an end portion of the cylindrical mass member. Dynamic damper.   The cylindrical dynamic damper according to claim 1 or 2, wherein the slit is formed unevenly on the circumference of the cylindrical metal spring in the cylindrical metal spring.   The cylindrical dynamic damper according to any one of claims 1 to 3, wherein the damping member is configured by fixing a damping material made of a polymer material so as to cover a surface of the cylindrical metal spring.   The damping member is formed of a damping material made of a polymer material, has a tapered cylindrical shape, and is spaced apart from the cylindrical metal spring in the direction perpendicular to the axis in an inserted state or an extrapolated state. And the large-diameter end of the damping member is fixed to the axial end of the cylindrical mass member, while the small-diameter end of the damping member is connected to the small-diameter end of the cylindrical metal spring. The cylindrical dynamic damper according to any one of claims 1 to 3, wherein the cylindrical dynamic damper is attached in close contact.   The cylindrical dynamic damper according to claim 5, wherein the damping member has a tapered cylindrical shape that covers the entire outer peripheral surface of the cylindrical metal spring, and is externally arranged on the cylindrical metal spring.   6. The cylindrical dynamic according to claim 1, wherein an annular seal protruding radially inward and extending in the circumferential direction is formed in an opening portion on a small diameter side of the pair of cylindrical metal springs. damper.

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