JP2016075379A - Dynamic damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dynamic damper of a new structure in which a resonance frequency of a mass-spring system can be set under a high degree of freedom in both axial direction and a direction perpendicular to an axis while preventing a reduction of durability of an elastic connector and an increased displacement in oscillation in a twisting direction of a mass.SOLUTION: A dynamic damper 10 comprises: a cylindrical fixing member 12 fixed to a cylindrical vibrator 28 under its inner inserted state; a mass 14 provided on an inner peripheral side of the fixing member 12; a plurality of elastic connectors 16 extending from an inner peripheral surface of the fixing member 12 toward the mass 14 formed on a periphery; and the fixing member 12 and the mass 14 being relatively connected in resiliency by a plurality of elastic connectors 16a to 16d for these members. The elastic connectors 16 are extended from the fixing member 12 toward the mass 14 with curved shape where an inclination angle in a peripheral direction in respect to a radial line is changed in a radial direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a dynamic damper that is attached to a cylindrical vibration body such as a propeller shaft in an inserted state and absorbs vibration energy of the cylindrical vibration body.

  Conventionally, a dynamic damper for reducing vibration is attached to a propeller shaft or the like that constitutes a power transmission system of an automobile. The dynamic damper is, for example, a mounting pipe as a cylindrical mounting member that is mounted in a cylindrical vibration body such as a propeller shaft in an inserted state as disclosed in Japanese Patent Application Laid-Open No. 2002-235802 (Patent Document 1). 2 and an inner weight 4 as a mass body on the inner peripheral side of the mounting pipe, and the mounting pipe and the inner weight are elastically coupled to each other by a plurality of mounting rubbers 5 as elastic coupling bodies. Has a structure. The dynamic damper includes a mass-spring system in which the inner weight is a mass and the mount rubber is a spring, and the inner weight is displaced in a resonance state with respect to the vibration input from the cylindrical vibrating body. The vibration energy of the shaped vibrator is absorbed as the kinetic energy of the inner weight, and the intended vibration damping effect is exhibited.

  By the way, in the dynamic damper, it is necessary to set the resonance frequency of the mass-spring system according to the frequency of the vibration that is a problem in the cylindrical vibrator, and in practice, the resonance frequency can be set to a lower frequency. Thus, a large degree of freedom in tuning can be obtained.

  However, in the dynamic damper disclosed in Patent Document 1, it is difficult to set the resonance frequency of the mass-spring system to a low frequency with respect to the vibration input in the direction perpendicular to the axis, and the frequency tuning that exhibits the damping effect is difficult. There was a risk that the degree of freedom would be limited. That is, in the structure of Patent Document 1, the mount rubber undergoes shear deformation with respect to axial vibration input, and the spring component of the mass-spring system is mainly used as the shear spring of the mount rubber. Thus, the resonance frequency of the mass-spring system can be set to a low frequency. On the other hand, for vibration input in a direction perpendicular to the axis, the mount rubber undergoes compression or tensile deformation in the radial direction, and the spring component of the mass-spring system is mainly the compression spring or tension spring of the mount rubber. There is a problem in that it is difficult to set the resonance frequency of the mass-spring system to a low frequency because the spring constant becomes larger than when the vibration is input in the axial direction.

  In order to set the resonance frequency of the mass-spring system low, it is conceivable that the mounting rubber is thinned in the axial direction and the springs in the axial direction and the axis perpendicular direction are set small. However, if the mounting rubber is thinned in the axial direction, the inner weight is likely to swing and displace in the twisting direction with respect to the mounting pipe, and the deflection of the inner weight may adversely affect the vibration state of the cylindrical vibrator. There is.

  Although it is conceivable to increase the mass of the inner weight, in order to increase the mass of the inner weight with the same material, it is necessary to enlarge the inner weight in at least one of the axial direction and the direction perpendicular to the axis. . However, when the axial dimension of the inner weight is increased, the moment in the twisting direction acting on the inner weight is increased, and there is a concern that the vibration state is deteriorated due to an increase in deflection displacement. On the other hand, when the inner weight is enlarged in the direction perpendicular to the axis, the distance between the mounting pipe and the inner weight in the radial direction is shortened, and the free length of the mounting rubber for elastically connecting the mounting pipe and the inner weight in the radial direction is reduced. For this reason, the spring constant of the mount rubber is increased, and the durability may be adversely affected.

JP 2002-235802 A

  The present invention has been made in the background of the above-mentioned circumstances, and the problem to be solved is that the axial direction is prevented while preventing a decrease in durability of the elastic coupling body and an increase in deflection displacement in the twisting direction of the mass body. An object of the present invention is to provide a dynamic damper having a novel structure in which the resonance frequency of the mass-spring system can be set with a large degree of freedom in any direction perpendicular to the axis.

  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.

  That is, the first aspect of the present invention includes a cylindrical mounting member that is attached to the cylindrical vibrator in an inserted state, and a mass body is disposed on the inner peripheral side of the mounting member. A dynamic damper in which a plurality of elastic coupling bodies extending from the inner peripheral surface of the mounting member toward the mass body are formed on the circumference, and the mounting member and the mass body are elastically coupled to each other by the plurality of elastic coupling bodies. The elastic coupling body is characterized by extending from the mounting member toward the mass body with a curved shape in which a circumferential inclination angle with respect to a radial line changes in the radial direction.

  According to the dynamic damper having the structure according to the first aspect as described above, while securing the mass of the mass body in the structure in which the outer diameter dimension is limited for the attachment in the insertion state with respect to the cylindrical vibrator. Thus, it is possible to set the frequency at which the intended vibration damping effect is exhibited to a lower frequency. That is, since the elastic coupling body has a shape that curves and extends in the circumferential direction, the free length of the elastic coupling body can be increased without changing the size and shape of the mounting member and the mass body, It becomes possible to set the spring of an elastic coupling body small. Therefore, the resonance frequency of the mass-spring system that uses the mass body as the mass component and the elastic coupling body as the spring component can be set to a lower frequency, and the frequency can be tuned freely so that the damping effect is exhibited. The degree is increased.

  In addition, since the elastic coupling body is curved and extended in the circumferential direction, shear deformation mainly occurs in the elastic coupling body with respect to the relative displacement of the mounting member and the mass body in the radial direction. Due to the low spring can be obtained. As described above, not only when the vibration is input in the axial direction but also when the vibration is input in the direction perpendicular to the axis, the resonance frequency of the mass-spring system can be easily set to a low frequency by the low spring of the shear spring.

  Further, since the free length of the elastic coupling body is ensured without increasing the distance between the mounting member and the mass body in the radial direction, it is not necessary to downsize the mass body in the direction perpendicular to the axis. As a result, the mass of the mass body is maintained without increasing the axial dimension, and an increase in the moment in the twisting direction due to the extension of the mass body in the axial direction is avoided. Displacement is suppressed. As a result, it is possible to prevent the deflection displacement of the mass body from adversely affecting the vibration state of the cylindrical vibrating body.

  Moreover, since it is not necessary to reduce the axial dimension of the elastic coupling body in order to lower the spring, the mounting member and the mass body are elastically coupled by the elastic coupling body over a wide range in the axial direction. The relative deflection displacement with respect to the member is suppressed. Therefore, it is prevented that the vibration state of the cylindrical vibrating body is deteriorated by the deflection displacement of the mass body. In particular, since the elastic coupling body is curved in the circumferential direction, and the free length in the direction connecting the mounting member and the mass body is large, the axial dimension of the elastic coupling body is relatively large. However, a sufficiently small spring can be realized in the axial direction and the direction perpendicular to the axis.

  In the present invention, it is desirable that the inclination angle of the elastic coupling body is continuously changed. For example, an aspect in which the inclination angle smoothly changes with a common tangent is desirable rather than a change with a polygonal angle. Thereby, a significant concentration of stress and strain can be avoided when the elastic coupling body is deformed, and the durability can be further improved, and a stable spring characteristic by a smooth load-deflection characteristic can be obtained more advantageously. It becomes possible.

  According to a second aspect of the present invention, in the dynamic damper described in the first aspect, the plurality of elastic coupling bodies are all inclined in the same circumferential direction with respect to the radial line.

  According to the second aspect, since the inclination directions of the plurality of elastic coupling bodies are the same circumferential direction, the deformation directions due to cooling after molding of the respective elastic coupling bodies are all the same circumferential direction. Is done. Therefore, the initial distortion of the elastic coupling body is automatically reduced or eliminated by the rotation of the mass body in the circumferential direction with respect to the mounting member. For example, the mounting member intended to reduce the initial distortion of the elastic coupling body It may be possible to omit the diameter reduction process.

  According to a third aspect of the present invention, in the dynamic damper described in the second aspect, the plurality of elastic coupling bodies have the same shape as each other, and the plurality of elastic coupling bodies are evenly arranged on the circumference. It is what is arranged.

  According to the third aspect, the spring characteristics of the plurality of elastic coupling bodies that elastically support the mass body are substantially the same, and the plurality of elastic coupling bodies are arranged uniformly on the circumference, thereby When the direction and the direction perpendicular to the axis are input, the deflection displacement of the mass body due to the unbalance of the support spring is prevented, and the intended vibration damping effect can be obtained effectively. In addition, since the plurality of elastic coupling bodies have substantially the same shape, the deformation amounts after the molding of the elastic coupling bodies are substantially the same, and the initial strain of the elastic coupling body is more efficiently reduced or reduced. Is avoided.

  According to a fourth aspect of the present invention, in the dynamic damper described in any one of the first to third aspects, the end on the attachment member side and the end on the mass body side of the elastic coupling body, They are arranged at positions that do not overlap each other in the radial projection.

  According to the fourth aspect, the elastic coupling body is hardly subjected to compressive deformation and tensile deformation between the mounting member and the mass body in the radial direction with respect to radial vibration input, and mainly causes shear deformation. It has become. Therefore, in the spring component of the mass-spring system, the compression spring and the tension spring of the elastic coupling body are reduced, so that the shear spring becomes dominant, thereby reducing the spring.

  According to a fifth aspect of the present invention, in the dynamic damper described in any one of the first to fourth aspects, the end on the attachment member side and the end on the mass body side of the elastic coupling body are Also, the dimension in the circumferential direction is made larger than the intermediate portion of the elastic coupling body.

  According to the fifth aspect, durability is improved by forming both end portions where stress is easily concentrated at the time of vibration input in the elastic coupling body with large dimensions in the circumferential direction. Furthermore, since the intermediate portion of the elastic coupling body is formed with a smaller dimension in the circumferential direction than both ends, the spring of the elastic coupling body is reduced, and the degree of freedom in tuning the resonance frequency of the mass-spring system is increased. Can be obtained.

  According to a sixth aspect of the present invention, in the dynamic damper described in any one of the first to fifth aspects, a fitting elastic body is fixed to an outer peripheral surface of the mounting member, and the cylindrical vibration is provided. The inner peripheral surface of the body and the outer peripheral surface of the mounting member are indirectly in contact with each other with the fitting elastic body interposed therebetween, so that the mounting member is attached to the cylindrical vibrator in an inserted state. .

  According to the sixth aspect, both the error of the inner diameter dimension of the cylindrical vibrator and the error of the outer diameter dimension of the mounting member are allowed by the fitting elastic body, and the dynamic damper is against the cylindrical vibrator. Thus, problems such as the inability to insert and insufficient fixation of the dynamic damper to the cylindrical vibrator are avoided.

  According to the present invention, since the elastic coupling body that elastically connects the mounting member and the mass body has a curved shape in which the circumferential inclination angle with respect to the radial line gradually changes in the length direction, the mounting member and It is possible to obtain a large free length of the elastic coupling body without changing the size and shape of the mass body. Therefore, even in the case of an insertion type dynamic damper in which the outer diameter dimension of the mounting member is limited by the internal dimension of the cylindrical vibrating body, the elastic coupling body is suppressed while suppressing the deflection displacement in the twisting direction of the mass body. It is possible to set the spring small, and a large degree of tuning freedom in the frequency range where the desired vibration damping action is exhibited can be obtained.

The front view which shows the dynamic damper as 1st embodiment of this invention. The right view of the dynamic damper shown in FIG. III-III sectional drawing of FIG. IV-IV sectional drawing of FIG. It is a longitudinal cross-sectional view which shows the mounting state to the propeller shaft of the dynamic damper shown in FIG. 1, Comprising: The figure corresponded in the VV cross section of FIG. VI-VI sectional drawing of FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  1-4 show a dynamic damper 10 as a first embodiment of the present invention. The dynamic damper 10 has a structure in which a cylindrical mounting member 12 and a mass member 14 as a mass body are elastically coupled to each other by a coupling rubber 16 as an elastic coupling body.

  More specifically, the attachment member 12 is a highly rigid member formed of iron, aluminum alloy, fiber-reinforced synthetic resin, or the like, and has a thin cylindrical shape with a large diameter. Further, the outer diameter dimension of the attachment member 12 is set smaller than the inner diameter dimension of the propeller shaft 28 described later.

  Further, a fitting rubber 18 as a fitting elastic body is fixed to the outer peripheral surface of the mounting member 12. The fitting rubber 18 has a substantially annular shape, and an inner peripheral portion on the mounting member 12 side protrudes to the outer peripheral side with a substantially constant axial dimension, and the outer peripheral portion has an axial end surface. Each is a tapered surface, and the axial dimension gradually decreases toward the outer peripheral side. In the present embodiment, a pair of fitting rubbers 18 and 18 are formed, and the pair of fitting rubbers 18 and 18 are arranged side by side at a predetermined distance in the axial direction.

  The mass member 14 has a solid substantially cylindrical shape, and in this embodiment, the mass member 14 is formed of a metal having a high density and a relatively low price, such as a rubber elastic body, an elastomer, or a synthetic resin. Etc., and is not particularly limited to metal. The mass member 14 has an outer diameter dimension smaller than an inner diameter dimension of the mounting member 12 and an axial dimension larger than the axial dimension of the mounting member 12.

  And the mass member 14 is inserted in the inner peripheral side of the attachment member 12, and the attachment member 12 and the mass member 14 are arrange | positioned on the same central axis, Between the radial directions of these attachment members 12 and the mass member 14, The connecting rubber 16 is disposed.

  The connecting rubber 16 has a longitudinal shape extending in a direction substantially perpendicular to the axis from the inner peripheral surface of the mounting member 12 toward the outer peripheral surface of the mass member 14. The end portion on the outer peripheral side of the connecting rubber 16 is fixed to the inner peripheral surface of the mounting member 12 via the outer peripheral cylindrical portion 20, and the end portion on the inner peripheral side of the connecting rubber 16 is the inner peripheral cylindrical portion. The mounting member 12 and the mass member 14 are elastically connected to each other by a connecting rubber 16. The length direction of the connecting rubber 16 refers to the direction connecting the mounting member 12 and the mass member 14, and the width direction of the connecting rubber 16 refers to the substantially circumferential direction orthogonal to the length direction.

  The outer peripheral cylindrical portion 20 and the inner peripheral cylindrical portion 22 are both substantially cylindrical rubber layers integrally formed with the connecting rubber 16, and the outer peripheral surface of the outer peripheral cylindrical portion 20 is vulcanized to the inner peripheral surface of the mounting member 12. While being bonded, the inner peripheral surface of the inner peripheral cylindrical portion 22 is vulcanized and bonded to the outer peripheral surface of the mass member 14. In other words, the outer peripheral cylindrical portion 20 and the inner peripheral cylindrical portion 22 are integrally connected by the connecting rubber 16, and the outer peripheral cylindrical portion 20 is vulcanized and bonded to the inner peripheral surface of the mounting member 12. By attaching the portion 22 to the outer peripheral surface of the mass member 14 by vulcanization, the attachment member 12 and the mass member 14 are elastically connected to each other by the connecting rubber 16. In the present embodiment, the axial dimension of the intermediate portion in the longitudinal direction of the connecting rubber 16 is made smaller than the axial dimensions of the outer peripheral cylindrical portion 20 and the inner peripheral cylindrical portion 22, and the spring in the intermediate portion of the connecting rubber 16 is It has been made smaller. Further, the outer peripheral cylindrical portion 20 fixed to the inner peripheral surface of the mounting member 12 and the fitting rubbers 18 and 18 fixed to the outer peripheral surface of the mounting member 12 are mutually connected through a communication hole (not shown) penetrating the mounting member 12. It is connected to and is integrally formed.

Further, the connecting rubber 16 has a concave curved surface 24 whose one surface in the width direction is curved in the circumferential direction, and a convex curved surface 26 whose other surface in the width direction is curved in the circumferential direction. Both sides of the direction are curved in the same circumferential direction. Accordingly, the connecting rubber 16 has a curved shape in which the inclination angle with respect to the radial line gradually changes in the length direction. In the present embodiment, as shown in FIG. 1, the radial direction of the elastic center line (C) The inclination angle with respect to the line (R) increases as going to the outer peripheral side. Specifically, as shown in FIG. 1, the angle (θ ₂ ) between the tangent (L ₂ ) and the radial line (R) at the outer peripheral end of the elastic center line (C) of the connecting rubber 16 is the elastic center. It is larger than the angle (θ ₁ ) formed by the tangent (L ₁ ) and the radial line (R) at the inner peripheral end of the line (C) (θ ₁ <θ ₂ ). By adopting such a connecting rubber 16 having a curved shape, the connecting rubber 16 has a length dimension that is larger than the distance between the opposing surfaces in the radial direction of the mounting member 12 and the mass member 14. Free length is secured. A plurality of connecting rubbers 16 are formed as will be described later. FIG. 1 exemplarily shows a radial line (R) and an elastic center line (C) for one connecting rubber 16a. did. Further, an inclination angle (θ ₁ ) with respect to the radial line (R) at the inner peripheral end of the elastic center line (C) and an inclination angle (θ ₂ ) with respect to the radial line (R) at the outer peripheral end of the elastic center line (C). ) With respect to the radial line (R) at a point on the elastic center line (C) and the inclination angle with respect to the radial line (R) at another point on the elastic center line (C). However, they should be different from each other. However, the inclination angle of the connecting rubber 16 with respect to the radial line (R) does not need to change over the whole, and may be partially constant.

  Furthermore, the connecting rubber 16 is positioned so that the outer peripheral end surface connected to the outer peripheral cylindrical portion 20 and the inner peripheral end surface connected to the inner peripheral cylindrical portion 22 are separated in the circumferential direction without overlapping each other in the radial projection. Yes. As a result, the connecting rubber 16 is hardly compressed in the radial direction between the mounting member 12 and the mass member 14 with respect to the relative displacement of the mounting member 12 and the mass member 14 in the radial direction, and shear deformation mainly occurs. It is like that.

  Furthermore, as for the connection rubber | gum 16, the outer peripheral end part connected to the outer peripheral cylinder part 20 and the inner peripheral end part connected to the inner peripheral cylinder part 22 are both made larger in the circumferential direction dimension than the intermediate part of the length direction. Yes. In this way, the inner and outer peripheral end portions of the connecting rubber 16 connected to the outer peripheral cylindrical portion 20 and the inner peripheral cylindrical portion 22 are increased in circumferential length, so that the connecting rubber tends to concentrate stress during deformation. Durability is improved at the inner and outer peripheral ends of 16. In addition, since the intermediate portion of the connecting rubber 16 has a relatively narrow width in the circumferential direction, the spring of the connecting rubber 16 can be reduced.

  Further, a plurality of connecting rubbers 16 are formed on the circumference, and in this embodiment, four connecting rubbers 16a, 16b, 16c, and 16d are formed on the circumference. Further, in the present embodiment, the four connecting rubbers 16a to 16d are formed of a single material, have substantially the same shape, and have substantially the same spring characteristics. In addition, the four connecting rubbers 16a to 16d are arranged substantially evenly on the circumference of the mounting member 12 and the mass member 14, and the mounting member of the mass member 14 with respect to axial and radial inputs to be described later The relative rotation with respect to 12 and the twisting displacement are prevented.

  Further, the four connecting rubbers 16a to 16d have substantially the same shape as each other, so that they are inclined and curved in the same direction in the circumferential direction. That is, the four connecting rubbers 16a to 16d of the present embodiment are all inclined clockwise in the circumferential direction with respect to the radial line, and are inclined clockwise in the circumferential direction with respect to the radial line as going to the outer peripheral side. Is getting bigger. As a result, the four connecting rubbers 16a to 16d contract in substantially the same direction by cooling after vulcanization molding, so that the attachment member 12 and the mass member 14 rotate relative to each other in the circumferential direction. The initial strain is quickly reduced or eliminated, and the durability of the connecting rubber 16 is improved. As described above, since the initial distortion of the connecting rubber 16 is automatically reduced or eliminated, it is not necessary to perform the drawing process on the mounting member 12 after the vulcanization molding of the connecting rubber 16, thereby reducing the number of manufacturing steps. Is possible.

  The attachment member 12 and the mass member 14 are elastically connected by the connecting rubber 16, so that the dynamic damper 10 has the first mass having the mass member 14 as a mass component and the connecting rubber 16 as a spring component. A spring system is configured. The resonance frequency of the first mass-spring system is tuned in accordance with the frequency of the vibration to be controlled which is a problem in the propeller shaft 28 described later.

  The dynamic damper 10 having such a structure is attached to a propeller shaft 28 as a cylindrical vibrator as shown in FIGS. That is, in the dynamic damper 10, the mounting member 12 is inserted into the propeller shaft 28, and the fitting rubber 18 is pressed against the inner peripheral surface of the propeller shaft 28, so that the mounting member 12 and the propeller shaft 28 face each other in the radial direction. It is narrowed between the faces. In this manner, the outer peripheral surface of the mounting member 12 is indirectly brought into contact with the inner peripheral surface of the propeller shaft 28 via the fitting rubber 18, and the mounting member 12 is mounted on the propeller shaft 28 in an inserted state. As a result, the dynamic damper 10 is attached to the propeller shaft 28 in an inserted state.

  When the vibration of the propeller shaft 28 is exerted on the mounting member 12 of the dynamic damper 10, the mass member 14 elastically supported via the connecting rubber 16 is displaced relative to the mounting member 12 and the propeller shaft 28. . As a result, the vibration energy of the propeller shaft 28 is absorbed as the kinetic energy of the mass member 14 and the vibration control action is exerted on the propeller shaft 28 that is the vibration isolation target member, so that the vibration of the propeller shaft 28 is reduced. It has become. In particular, since the resonance frequency of the first mass-spring system in the dynamic damper 10 is set in accordance with the frequency of the main input vibration in the axial direction and the direction perpendicular to the axial direction, the intended damping action is effective. Has come to be demonstrated.

  In the dynamic damper 10 of the present embodiment, since the mounting member 12 is elastically supported by the propeller shaft 28 via the fitting rubber 18, the mass component including the mounting member 12, the mass member 14, and the connecting rubber 16, A second mass-spring system is constituted by the spring component of the fitting rubber 18. Thereby, also in the second mass-spring system, the vibration energy of the propeller shaft 28 is absorbed as the kinetic energy of the mass component, so that it is possible to obtain a more excellent vibration damping performance. For example, if the resonance frequency of the second mass-spring system is tuned to a frequency different from the resonance frequency of the first mass-spring system, the vibration suppression effect is applied to a plurality of types of vibrations having different frequencies. Can be obtained.

  In the dynamic damper 10 having the structure according to this embodiment, since the connecting rubber 16 is curved, a large free length of the connecting rubber 16 is secured, and the axial direction and the axis perpendicular to the connecting rubber 16 are secured. The spring constant in the direction is set small. As a result, the resonance frequency of the first mass-spring system in the dynamic damper 10 can be set to a lower frequency, and the first mass-spring system has a higher degree of freedom in tuning. It is possible to effectively obtain the vibration damping action in the region.

  Moreover, since the connecting rubber 16 has a shape that curves in the circumferential direction, the free length of the connecting rubber 16 is set large, so that the free length of the connecting rubber 16 can be increased without reducing the diameter of the mass member 14. Can be secured. Accordingly, it is not necessary to increase the axial dimension of the mass member 14 in order to secure mass, and the moment in the twisting direction acting on the mass member 14 is reduced, so that an increase in deflection displacement is prevented and the propeller is prevented. An adverse effect on the vibration state of the shaft 28 is prevented.

  In addition, since the free length of the connecting rubber 16 is set to be large and the spring is reduced, the axial dimension of the connecting rubber 16 is set to be relatively large so that the deflection displacement of the mass member 14 in the twisting direction is reduced. It can also be prevented more effectively.

  Further, since the connecting rubber 16 extends while being inclined with respect to the radial line, the intermediate portion of the connecting rubber 16 undergoes shear deformation with respect to the radial vibration input. Therefore, in the spring component of the first mass-spring system, the shear spring component of the connecting rubber 16 is dominant, and the resonance frequency of the mass-spring system can be set with a large degree of freedom by reducing the spring. . Furthermore, since the connecting rubber 16 has an intermediate portion in the length direction that is narrower in the circumferential direction than both end portions, the spring constant can be set smaller.

  Moreover, in the present embodiment, the outer peripheral end and the inner peripheral end of the connecting rubber 16 are positioned so as to deviate from each other in the circumferential direction so as not to overlap each other in the radial projection. Therefore, the compression spring and the tension spring of the connecting rubber 16 are further reduced with respect to the vibration input in the radial direction, and a low spring by the shear spring component is realized.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited by the specific description. For example, the specific shape and the number of formed elastic coupling bodies are examples, and can be appropriately changed according to required spring characteristics, durability, and the like.

  Furthermore, it is desirable that all of the plurality of elastic coupling bodies be curved in the same circumferential direction. For example, at least one elastic coupling body is opposite to at least one other elastic coupling body in the circumferential direction. It may be curved. In addition, after vulcanization molding of the elastic coupling body, the elastic coupling body is pre-compressed in the length direction by subjecting the mounting member 12 to a diameter reduction process such as an eight-way drawing, so that an initial strain of the elastic coupling body is obtained. Can be reduced, and durability can be improved.

  Furthermore, it is desirable that one elastic coupling body is curved in the same circumferential direction as a whole. For example, the shape in which the bending direction changes in the circumferential direction opposite to the middle in the radial direction (for example, as viewed in the axial direction). In addition, an S-shaped elastic connection body may be employed.

  Moreover, in the said embodiment, although the structure by which the connection rubber | gum 16 as an elastic coupling body was directly vulcanized-bonded with respect to the mass member 14 as a mass body is illustrated, for example, an elastic coupling body of A structure in which the inner cylinder member is fixed to the inner peripheral surface can also be adopted. Specifically, for example, a small-diameter cylindrical inner cylinder member is vulcanized and bonded to the inner peripheral surface of the connecting rubber 16, and the inner cylinder member and the mounting member 12 are elastically connected to each other by the connecting rubber 16. A structure in which the mass member 14 and the mounting member 12 are elastically connected by the connecting rubber 16 by post-fixing the mass member 14 to the member by means such as press-fitting can also be adopted. According to this, by selecting one appropriately from a plurality of mass members 14 having different masses and fixing the selected mass member 14 to the inner cylinder member, a common vulcanized molded product can be used. Different types of dynamic dampers can be obtained.

  Furthermore, the shape of the mass body is not limited to a cylindrical shape, and a polygonal column shape, a cylindrical shape, a spherical shape, an irregular shape, and the like may be appropriately employed.

  The fitting rubber 18 shown in the above embodiment is merely an example of a fitting elastic body, and the shape and the like can be changed as appropriate. Specifically, for example, it is not necessary to provide two fitting elastic bodies side by side in the axial direction, and only one may be formed.

10: dynamic damper, 12: mounting member, 14: mass member (mass body), 16: connecting rubber (elastic connecting body), 18: fitting rubber (inserting elastic body), 28: propeller shaft (cylindrical vibrator) )

Claims (6)

A cylindrical attachment member that is attached to the cylindrical vibration body in an inserted state is provided, and a mass body is disposed on the inner peripheral side of the attachment member. From the inner peripheral surface of the attachment member to the mass body In the dynamic damper in which a plurality of elastic connecting bodies extending toward the periphery are formed on the circumference, and the attachment member and the mass body are elastically connected to each other by the plurality of elastic connecting bodies,
The dynamic damper is characterized in that the elastic coupling body extends from the mounting member toward the mass body with a curved shape in which a circumferential inclination angle with respect to a radial line changes in the radial direction.   The dynamic damper according to claim 1, wherein the plurality of elastic coupling bodies are all inclined in the same circumferential direction with respect to the radial line.   The dynamic damper according to claim 2, wherein the plurality of elastic coupling bodies have the same shape as each other, and the plurality of elastic coupling bodies are evenly arranged on the circumference.   The end part on the attachment member side and the end part on the mass body side in the elastic coupling body are arranged at positions where they do not overlap each other in radial projection. Dynamic damper.   The end portion on the attachment member side and the end portion on the mass body side in the elastic coupling body are both larger in the circumferential dimension than the intermediate portion of the elastic coupling body. Dynamic damper described in 1.   A fitting elastic body is fixed to the outer peripheral surface of the mounting member, and the inner peripheral surface of the cylindrical vibrating body and the outer peripheral surface of the mounting member are indirectly in contact with each other with the fitting elastic body interposed therebetween. The dynamic damper according to any one of claims 1 to 5, wherein the attachment member is attached to the cylindrical vibrator in an inserted state.

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