JP2019070396A - Dynamic damper - Google Patents

Abstract

To provide a dynamic damper 11 which is capable of improving rigidity of a stopper 21 which regulates an eccentric amount of a damper mass 14, and further, capable of improving the rigidity of the stopper 21 without increasing the number of components of the dynamic damper 11, thereby sufficiently presenting a damper mass eccentric amount regulation effect and also prevents a region in which a vibration control effect can be obtained from being narrowed.SOLUTION: In the dynamic damper 11 in which the damper mass 14 is connected to an inner peripheral side of an outer pipe 12 via a damper rubber 12, the mass stopper part 21 is provided for regulating the eccentric amount of the damper mass 14 to a predetermined amount. The mass stopper part 21 is structured by partially bending the outer pipe 12 in a direction where the outer pipe becomes closer to the damper mass 14.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a dynamic damper according to a vibration isolation technology.

  Generally, as shown in FIGS. 4A and 4B, the dynamic damper 51 has a structure in which the damper mass 54 is connected to the inner peripheral side of the outer pipe 52 via the damper rubber 53. From this structure, the axial direction is It has a natural frequency in the direction perpendicular to the axis, in the direction of twist, and in the direction of prying.

  The dynamic damper 51 is mounted in the hollow propeller shaft 61 used to transmit the driving force of the vehicle, suppresses vibration of the propeller shaft 61, improves quietness during traveling, and reduces strength due to resonance of the propeller shaft 61 itself. It is used to suppress.

Japanese Patent Application Publication No. 2004-150543

  By the way, with the vehicle weight reduction etc. in recent years, the natural frequency of the direction perpendicular | vertical to the axial direction (radial direction) calculated | required by the dynamic damper 51 is falling. As the natural frequency decreases in the direction perpendicular to the axis, the damper mass 54 may be largely decentered at the rotational speed in the normal region, which may lead to rubber breakage. In addition, depending on the vehicle, the input in the normal region is large, which may lead to rubber breakage.

  As a conventional damper mass eccentricity countermeasure, as shown in FIG. 5, there is one in which a convex shape 55 made of a rubbery elastic body is provided as a stopper on the inner peripheral surface of the outer pipe 52 between damper rubbers 53 adjacent to each other. According to the above, the eccentricity of the damper mass 54 is restricted by the damper mass 54 coming into contact with the convex shape 55 at the time of excessive load input.

  However, in the structure of FIG. 5, since the convex shape 55 is made of a rubber-like elastic body, the rigidity required as a stopper can not be secured, and hence the damper mass eccentricity regulating effect may not be sufficiently obtained. As shown in the comparative example (dotted line) in the graph of FIG. 3, even if the stopper operation is performed by the damper mass 54 coming into contact with the convex shape 55 at point A, the convex shape 55 is compressed thereafter. Eccentricity tends to increase).

  It is also conceivable to set the radial clearance (interval) c between the damper mass 54 and the convex shape 55 small beforehand in anticipation of the compression of the convex shape 55 when the damper mass 54 contacts the convex shape 55. In this case, the timing at which the damper mass 54 comes in contact with the convex shape 55 is advanced, so the area in which the anti-vibration effect can be obtained is narrowed.

  In view of the above points, the present invention can increase the rigidity of the stopper that regulates the eccentricity amount of the damper mass, and can increase the rigidity of the stopper without increasing the number of components of the dynamic damper. It is an object of the present invention to provide a dynamic damper that can sufficiently exhibit the core amount regulation effect and does not narrow the area where the vibration isolation effect can be obtained.

  In order to solve the above problems, the dynamic damper of the present invention is a dynamic damper having a damper mass connected to the inner peripheral side of an outer pipe via a damper rubber, provided with a mass stopper portion for regulating the eccentricity amount of the damper mass to a predetermined amount. The mass stopper portion has a structure in which a part of the outer pipe is bent in a direction approaching the damper mass.

  As an embodiment, in the above-mentioned dynamic damper, the mass stopper portion has a structure in which an axial end of the outer pipe is bent in a direction approaching the damper mass over the entire circumference. .

  As an embodiment, in the above-mentioned dynamic damper, the mass stopper portion has a structure in which an axial end portion of the outer pipe is bent in a direction approaching the damper mass at a part on a circumference. Do.

  In the present invention, since the mass stopper portion has a structure in which a part of the outer pipe is bent in a direction approaching the damper mass, the rigidity of the mass stopper portion is determined not by rubber but by the rigidity of the outer pipe. Even if a mass stopper portion is provided as a part of the outer pipe in the dynamic damper provided with the outer pipe, the damper rubber and the damper mass, the number of components of the dynamic damper does not increase. Further, since the mass stopper portion whose rigidity is enhanced does not deform even when the load is inputted, it is not necessary to set the clearance between the damper mass and the mass stopper portion small beforehand. Therefore, the rigidity of the stopper which regulates the eccentricity amount of the damper mass can be enhanced from the above as the problem to be solved in the present invention, and the rigidity of the stopper can be enhanced without increasing the number of components of the dynamic damper. Thus, the damper mass eccentricity regulation effect can be sufficiently exhibited, and a dynamic damper can be provided without narrowing the area where the vibration isolation effect can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the dynamic damper which concerns on embodiment, (A) is the front view, (B) is the sectional drawing, and the DD sectional drawing in (A) It is a figure which shows the dynamic damper which concerns on other embodiment, (A) is the front view, (B) is the sectional drawing, and the EE sectional drawing in (A) Graph showing the result of comparative test It is a figure which shows the dynamic damper which concerns on a prior art example, (A) is the front view, (B) is sectional drawing cut | judged by the plane containing the central axis FIG. 8 is a view showing a dynamic damper according to another conventional example, and a sectional view cut by a plane perpendicular to the axis thereof

  As shown in FIG. 1, the dynamic damper 11 according to the embodiment is a shaft internal-type / inner-type dynamic damper mounted in a hollow portion of a propeller shaft (not shown) which is a rotation shaft.

  The dynamic damper 11 has an outer pipe (outer cylinder) 12 fitted to the inner peripheral surface of the hollow portion of the propeller shaft as its component parts, and a plurality of outer pipes 12 are circumferentially provided on the inner peripheral side of the outer pipe 12 The damper mass 14 is concentrically connected via the damper rubber (rubber foot) 13 of 5 equal allocations. The surface of the outer pipe 12 may be covered with a rubber-like elastic body integral with the damper rubber 13, and the surface of the damper mass 14 may also be covered with a rubber-like elastic body integral with the damper rubber 13. The outer pipe 12 and the damper mass 14 are each formed of a rigid material such as a predetermined metal.

  Further, a mass stopper portion 21 is provided for restricting the amount of eccentricity of the damper mass 14 with respect to the outer pipe 12 by a predetermined amount, and this mass stopper portion 21 serves as the damper mass 14 for one axial end portion 12 a of the outer pipe 12. It is configured to be bent in a direction approaching the outer peripheral surface 14a of.

  One axial end portion 12 a of the outer pipe 12 is bent over the entire circumference, whereby a mass stopper portion 21 is provided over the entire circumference of the outer pipe 12.

  The bending angle is set to an angle less than 90 degrees, and it is possible to adjust the size of the radial clearance (distance) c between the damper mass 14 and the mass stopper portion 21 depending on the magnitude of the bending angle. The bending angle may be 90 degrees or 90 degrees or more depending on the product specification and the like.

  In the dynamic damper 11 configured as described above, the mass stopper portion 21 has a structure in which one axial end portion 12 a of the outer pipe 12 is bent in a direction approaching the outer peripheral surface 14 a of the damper mass 14. The rigidity 21 is determined not by rubber but by the rigidity of the outer pipe 12. Therefore, the rigidity of the mass stopper portion 21 is enhanced as compared with the prior art.

  Further, since the mass stopper portion 21 is provided as a part of the outer pipe 12 in the dynamic damper 11 including the outer pipe 12, the damper rubber 13 and the damper mass 14, the number of components of the dynamic damper 11 is the same even if the mass stopper portion 21 is provided. It is considered equivalent to the above-mentioned prior art. Therefore, since the number of components of the dynamic damper 11 does not increase, cost increase due to the increase of the number of components can be avoided.

  Further, the mass stopper portion 21 whose rigidity is enhanced starts the stopper operation immediately when the damper mass 14 contacts the mass stopper portion 21 and thereafter, the mass stopper portion 21 is not deformed even if a load due to eccentricity is input. (When the damper mass 14 contacts the mass stopper portion 21 at point A as shown in the embodiment (solid line) in the graph of FIG. 3, the mass stopper portion 21 is not deformed even if a radial load due to eccentricity is input thereafter Because the mass eccentricity does not increase). Therefore, the radial clearance c between the damper mass 14 and the mass stopper portion 21 does not have to be set small in advance in view of the deformation of the mass stopper portion 21 as in the above-mentioned prior art, so that the region where the vibration damping effect can be obtained is narrowed Can be avoided.

  Therefore, the rigidity of the mass stopper portion 21 that regulates the eccentricity amount of the damper mass 14 can be enhanced, and the rigidity of the mass stopper portion 21 can be enhanced without increasing the number of components of the dynamic damper 11. Damper mass eccentricity regulation effect can be exhibited sufficiently, and the dynamic damper 11 can be provided without narrowing the area where the vibration isolation effect can be obtained.

  The mass stopper portion 21 may be provided not on the entire circumference of the outer pipe 12 but on a part of the circumference.

  That is, in another embodiment shown in FIGS. 2 (A) and 2 (B), the mass stopper portion 21 has a plurality of circumferentially arranged end portions 12a of the outer pipe 12 in the axial direction. At this time, the damper mass 14 is bent in a direction approaching the outer peripheral surface 14a of the damper mass 14, and according to this structure, the bending process of the outer pipe 12 is localized on the circumference, thus facilitating the bending process. can do.

11 Dynamic Damper 12 Outer pipe 12a One axial end 13 Damper rubber 14 Damper mass 14a Outer peripheral surface 21 Mass stopper portion (stopper)

Claims (3)

In a dynamic damper in which a damper mass is connected to the inner peripheral side of an outer pipe via a damper rubber,
Providing a mass stopper portion for regulating an eccentricity amount of the damper mass to a predetermined amount;
The dynamic damper, wherein the mass stopper portion has a structure in which a part of the outer pipe is bent in a direction approaching the damper mass. In the dynamic damper according to claim 1,
The dynamic damper, wherein the mass stopper portion has a structure in which an axial end portion of the outer pipe is bent in a direction approaching the damper mass over the entire circumference. In the dynamic damper according to claim 1,
The dynamic damper, wherein the mass stopper portion has a structure in which an axial end portion of the outer pipe is bent in a direction approaching the damper mass at a part on a circumference.

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