JP2005273703A - Dynamic damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dynamic damper capable of independently attenuating two types of vibration of high frequency and low frequency generated on a pipe member such as a drive shaft for a vehicle. <P>SOLUTION: The dynamic damper 10 is provided with a disk shape attachment metal fitting 11 press-fitted in the drive shaft 1 and fixed to the drive shaft 1 in a condition vertical to an axial direction, a rod shaped center axis metal fitting 13 fixed on center on one surface side (left surface in a figure) of the attachment fitting 11 and vertically extending, a cylindrical mass metal fitting 14 coaxially arranged outward in radial direction of the center axis metal fitting 13 with keeping interval from the center axis metal fitting 13 and an attachment metal fitting11, a rubber elastic body 16 elastically connecting the attachment fitting 11, the center axis metal fitting 13 and the mass metal fitting 14, and a pair of recessed parts 18 extending in an axial direction on both sides of the center axis metal fitting 13 of the rubber elastic body 16 in radial direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a dynamic damper that is mounted in a pipe member such as a drive shaft, a propeller shaft, and a tube in a seat of a vehicle and attenuates vibration generated on the pipe member.

Conventionally, as this type of dynamic damper, for example, as shown in Patent Document 1, a long cylindrical metal elastic body, and a long cylindrical rubber elastic member that has a press-fit hole while bonding the mass body. It is known that the press-fitting hole of the elastic member is fixed to the joint part by being press-fitted into a damper mounting part that is attached to the joint part fixed to the propeller shaft and extends in the axial direction. In this dynamic damper, the elastic member is deformed in the compression direction, and its resonance frequency is set to a high frequency, and is used to attenuate high-frequency vibrations of the propeller shaft.
ACT 2-103543

In addition, as another dynamic damper, for example, as shown in Patent Document 2, an outer cylinder portion formed in a cylindrical shape is provided, and the central portion formed in a rod shape is provided in the outer cylinder portion inside, and the longitudinal direction of the propeller shaft A weight part formed with a hole penetrating the inside is provided, the weight part is fixed inside the outer cylinder part, and it is formed in a ring shape with a substantially H-shaped cross section with a rubber material so as to have a damping function, and the circumference There is known a structure in which a damping member in which a plurality of through holes are formed at equal intervals is provided and a damper portion is configured by an outer cylinder portion, a weight portion, and a damping member.
No. 7-29324

  By the way, in a pipe member such as a drive shaft, the generated vibration may include two types of vibration, a low frequency vibration in a range of about 100 to 400 Hz and a high frequency vibration of about 500 Hz. In order to attenuate such two types of vibrations, conventionally, two types of dynamic dampers having resonance frequencies tuned to the respective vibration frequencies have been used. However, there is a problem that the member cost of the dynamic damper becomes high and the mounting cost to the drive shaft becomes expensive. As described above, each of the conventional dynamic dampers corresponds to a single vibration frequency and does not have a function of simultaneously attenuating two types of vibrations.

  An object of the present invention is to provide a dynamic damper capable of independently attenuating two kinds of vibrations of a high frequency and a low frequency generated in a pipe member such as a drive shaft of a vehicle. And

  In order to achieve the above object, a structural feature of the present invention is a plate-like mounting bracket that is inserted into a mating pipe member by press fitting and fixed in a state perpendicular to the axial direction of the mating pipe member. A central shaft bracket that is fixed in the center on one side of the mounting bracket and extends vertically, and a cylindrical mass bracket that is disposed radially outward of the central shaft bracket and spaced from the central shaft bracket and the mounting bracket, A rubber elastic body that elastically connects between the central shaft bracket and the mass bracket, and a pair of straight portions extending in the axial direction on both sides in the radial direction across the central shaft bracket of the rubber elastic body is there.

  In the invention configured as described above, a pair of straight portions extending in the axial direction on both sides in the radial direction sandwiching the central shaft metal fitting of the rubber elastic body that elastically connects the mass metal fitting and the central shaft metal fitting. Provided. Therefore, in the radial direction connected by the rubber elastic body, the elastic constant of the rubber elastic body is increased by compressing and deforming the rubber elastic body, and as a result, high-frequency vibrations can be attenuated. In the radial direction in which the rubber elastic body is disposed, the rubber elastic body undergoes shear deformation, whereby the spring constant of the rubber elastic body is reduced, and as a result, low-frequency vibration can be attenuated. As described above, the dynamic damper according to the present invention can attenuate two types of vibrations of a high frequency and a low frequency that are generated in the mating pipe member independently.

  Further, since the value of the resonance frequency on the low frequency side can be adjusted by adjusting the axial length of the straight portion, the vibration can be appropriately attenuated according to the vibration frequency of the counterpart pipe member. Furthermore, since the mass metal is made heavy and the rubber elastic body is softened, the mass metal is easily swung with respect to vibration in the radial direction, but the movement of the mass metal is restricted by the central shaft metal. As a result, in the present invention, since the interference with the mating pipe member of the mass metal fitting is prevented, the vibration damping function of the dynamic damper is ensured.

  In the present invention, the straight portion may penetrate the rubber elastic body in the axial direction. As described above, since the straight portion penetrates the rubber elastic body in the axial direction, the rubber elastic body is sufficiently sheared and the resonance frequency of the dynamic damper can be set to the lowest frequency.

  In the present invention, it is possible to provide an axial rubber portion that extends in the axial direction from the rubber elastic body and connects between the mounting bracket and the end face of the mass bracket facing the mounting bracket. Thereby, in addition to the rubber elastic body, the axial rubber portion is also shear-deformed, thereby contributing to the low-frequency vibration damping of the dynamic damper. In addition, by providing the rubber part in the axial direction, the mass bracket is more stably supported by the mounting bracket, and the mass bracket is moved to the mounting bracket by the axial movement of the mass bracket subjected to the axial vibration. The inconvenience of collision is reliably prevented.

  Further, in the present invention, the mounting bracket may be provided with a flange portion extending in the axial direction on the outer peripheral edge contacting the inner peripheral surface of the mating pipe member. As described above, by providing the flange portion extending in the axial direction on the outer peripheral edge of the mounting bracket, the press-fitting of the mounting bracket to the mating pipe member is smoothly performed in a coaxial manner, so that the press-fit workability is further improved. . Further, the contact area between the mounting bracket and the mating pipe member is increased by the flange portion, so that the contact strength with the mating pipe member is increased, and the mounting bracket is securely fixed to the mating pipe member.

  In the present invention, the surface of the mounting bracket may be covered with a thin rubber coating layer. Thereby, the press-fitting of the mounting bracket to the mating pipe member is smoothly performed through the thin rubber coating layer. Moreover, since the mounting bracket is protected by the rubber coating layer, there is no need to perform rust prevention treatment.

  According to the present invention, by providing a pair of straight portions extending in the axial direction on both sides in the radial direction across the central shaft bracket of the rubber elastic body that elastically connects the mass bracket and the central shaft bracket. The high-frequency vibrations can be effectively damped in the radial direction connected by the rubber elastic body, and the low-frequency vibrations can be effectively damped in the radial direction in which the straight portions are arranged. As a result, in the present invention, vibrations of two different frequencies can be damped by the dynamic damper alone, so that the member cost and the attachment cost to the mating pipe member can be greatly reduced as compared with the conventional case. Further, since the value of the resonance frequency on the low frequency side can be adjusted by adjusting the axial length of the straight portion, the vibration can be appropriately attenuated according to the vibration frequency of the counterpart pipe member. Furthermore, the movement of the mass metal member in the radial direction is restricted by the central shaft metal fitting, so that interference with the mating pipe member of the mass metal fitting is prevented, and the vibration damping function of the dynamic damper is ensured.

Embodiments of the present invention will be described below with reference to the drawings.
1 and 2 are cross-sectional views taken along a line I-I of a dynamic damper inserted into a drive shaft (a mating pipe member) of a vehicle, which is a cylindrical rotating shaft having a hollow portion according to an embodiment. It is shown by the left side view. The dynamic damper 10 is inserted into the drive shaft 1 by press-fitting and fixed in a state perpendicular to the axial direction of the drive shaft 1, and one surface side of the mounting bracket 11 (illustrated) A round bar-shaped central shaft bracket 13 which is fixed at the center position on the left surface) and extends vertically, and is coaxially spaced apart from the central shaft bracket 13 and the mounting bracket 11 radially outward of the central shaft bracket 13. A cylindrical mass fitting 14, a rubber elastic body 16 elastically connecting the central shaft fitting 13 and the mass fitting 14, and a shaft elastically connecting the mounting fitting 11 and the mass fitting 14. A directional rubber portion 17 and a pair of straight portions 18 which are spaces extending in the axial direction on both radial sides sandwiching the central shaft fitting 13 of the rubber elastic body 16 are provided. In the embodiment, the drive shaft 1 mainly has a large diameter of about 40 to 50 mmφ.

  The mounting bracket 11 has an annular flange portion 12 that is bent at a right angle around the entire outer periphery and slightly protrudes to the other surface side (the right surface in the figure). The outer diameter of the flange portion 12 is the drive shaft 1. It is made slightly larger than the inner diameter of the drive shaft 1 for press-fitting into the drive shaft 1. The mass fitting 14 has an outer diameter smaller than the inner diameter of the drive shaft 1, the inner diameter is about three times the outer diameter of the central shaft fitting 13, and the axial length is shorter than the axial length of the central shaft fitting 13. It has become. The mass fitting 14 is axially separated from one surface of the mounting fitting 11 and is coaxially disposed between both axial ends of the central shaft fitting 13, and has a diameter between the inner peripheral surface and the central shaft fitting 13. The gap in the direction and the radial gap between the outer peripheral surface and the inner peripheral surface of the drive shaft 1 are substantially the same.

  The rubber elastic body 16 is provided between the axial direction from the vicinity of the left end in the axial direction of the mass metal fitting 14 to the right end, and approximately 1/4 of the circumferential direction of the inner peripheral surface of the attachment metal 11 and the outer circumference of the central shaft metal fitting 13 opposed thereto. The surface is elastically connected. The axial rubber portion 17 extends from the rubber elastic body 16 in the axial direction and connects between the mounting bracket 11 and one end face of the mass bracket 14 facing the mounting bracket 11 and has a substantially arc shape when viewed from the axial direction. ing. The rubber elastic body 16 and the axial rubber portion 17 are integrally formed by rubber vulcanization molding. The pair of straight portions 18 are disposed through the rubber elastic body 16 in the axial direction on both sides in the radial direction perpendicular to the rubber elastic body 16 and sandwiching the central shaft fitting 13.

  In the embodiment configured as described above, the central shaft bracket is attached to the rubber elastic body 16 that elastically connects the mass bracket 14 of the dynamic damper 10 inserted into the drive shaft 1 and the central shaft bracket 13. A pair of straight portions 18 penetrating in the axial direction are provided on both sides in the radial direction across 13. Therefore, in the radial direction connected by the rubber elastic body 16, the rubber elastic body 16 is compressed and deformed to increase its spring constant. As a result, the dynamic damper 10 attenuates vibrations at a high frequency of about 500 Hz. Can do. On the other hand, in the radial direction in which the straight portion 18 is disposed, the rubber elastic body 16 and the axial rubber portion 17 are subjected to shear deformation, whereby the spring constants of the rubber elastic body 16 and the axial rubber portion 17 are reduced. The dynamic damper 10 can attenuate low-frequency vibrations in the range of about 100 to 400 Hz.

 As a result, in the embodiment, the dynamic damper 10 can dampen two kinds of vibrations of a high frequency and a low frequency by itself, so that the member cost of the dynamic damper and the mounting to the drive shaft 1 can be reduced as compared with the conventional one. Cost is greatly reduced. Further, since the straight portion 18 penetrates the rubber elastic body 16 in the axial direction, the rubber elastic body 16 is sufficiently sheared and the resonance frequency of the dynamic damper 10 can be set to the lowest frequency. . Furthermore, since the mass metal member 14 is made heavy and the rubber elastic body 16 is softened, the mass metal member 14 is likely to swing with respect to vibration in the radial direction of the drive shaft 1. It is regulated by the shaft fitting 13. As a result, in the embodiment, interference between the mass metal fitting 14 and the drive shaft 1 is prevented, and the vibration damping function of the dynamic damper is ensured.

  Further, in the embodiment, by providing the axial rubber portion 17 following the rubber elastic body 16, in addition to the rubber elastic body 16, the axial rubber portion 17 is also shear-deformed, so that the low frequency of the dynamic damper 10 is obtained. Can contribute to vibration damping. Further, by providing the axial rubber portion 17, the mass metal fitting 14 is more stably supported by the mounting metal fitting 11, and the mass metal fitting 14, which has received axial vibration, moves in the axial direction. The disadvantage that 14 collides with the mounting bracket 11 is reliably prevented. Further, in the embodiment, by providing the flange portion 12 extending in the axial direction on the outer peripheral edge of the mounting bracket 11, the press-fitting of the mounting bracket 11 to the drive shaft 1 is smoothly performed coaxially. Workability is further enhanced. Further, since the contact area of the mounting bracket 11 with the drive shaft 1 is increased by the flange portion 12, the contact strength with the drive shaft 1 is increased, and the mounting bracket 11 is securely attached to the drive shaft 1.

Next, Modification 1 of the embodiment will be described.
In Modification 1, as shown in FIGS. 3 and 4, one surface side of the mounting bracket 11 including the flange portion 12 is covered with a thin rubber coating layer 21. Thereby, the press fitting of the mounting bracket 11 to the drive shaft 1 is smoothly performed through the thin rubber coating layer 21, and the labor of the press fitting work of the mounting bracket 11 is reduced. The mounting strength of the mounting bracket 11 to the drive shaft 1 is also ensured by the rubber coating layer 21. Further, since the mounting bracket 11 is protected by the rubber coating layer 21, it is not necessary to perform rust prevention treatment on one surface side of the mounting bracket 11.

Next, a second modification of the embodiment will be described.
In the second modification, as shown in FIGS. 5 and 6, a straight portion 23 with respect to the rubber elastic body 16 is provided in a part in the axial direction, specifically, in the range from the left end side in the axial direction to the center in the axial direction. The rubber connecting portion 24 is left in the axial direction portion following the portion 23. As a result, if the axial length of the straightened portion 23 is short, the spring constant of the rubber elastic body 16 is increased and the shearing deformation is difficult to occur, and the rubber elastic body is increased by increasing the axial length of the straightened portion 23. The spring constant of 16 is reduced to facilitate shear deformation, and accordingly, the resonance frequency of the dynamic damper 10 is increased or decreased. As a result, according to the second modification, the value of the resonance frequency on the low frequency side can be adjusted within a range of about 100 to 400 Hz by adjusting the axial length of the straight portion 23, so that the drive shaft The vibration on the low frequency side can be appropriately damped according to the vibration frequency of 1.

  In the above-described embodiments and modifications, the axial rubber portion 17 is provided that extends in the axial direction from the rubber elastic body 16 and connects between the mounting bracket 11 and the end surface of the mass bracket 14 facing the mounting bracket 11. If necessary, the axial rubber portion 17 can be omitted. Moreover, in the said Example and modification, although the attachment metal fitting is made into disk shape, it can replace with this and a attachment metal fitting can also be made into a rectangular shape. Moreover, in each said Example and modification, although the flange part is provided in the outer periphery of the attachment metal fitting, this can also be omitted as needed.

  In each of the above embodiments and modifications, the dynamic damper is inserted and used in the drive shaft. However, other dynamic shafts such as a propeller shaft or pipe members such as a pipe in a seat are used. Can be used to attenuate the radial vibration. In addition, the dynamic dampers shown in the above embodiments and modifications are merely examples, and can be implemented in various forms without departing from the spirit of the present invention.

  According to the present invention, the dynamic damper attached in the mating pipe member such as a drive shaft is provided on both sides in the radial direction with the central shaft metal fitting of the rubber elastic body elastically connecting between the mass metal fitting and the central shaft fitting. By providing a pair of straight portions extending in the axial direction, high-frequency vibrations can be effectively performed in the radial direction connected by rubber elastic bodies, and low-frequency vibrations can be effectively achieved in the radial direction where the straight portions are arranged. It can be damped, which is useful because it can greatly reduce the member cost and the cost of attachment to the mating pipe member.

It is sectional drawing of the II line direction of FIG. 2 which shows the dynamic damper inserted by the drive shaft of the motor vehicle which is an Example of this invention. It is a left view which shows the dynamic damper. It is sectional drawing of the III-III line direction of FIG. 4 which shows the dynamic damper inserted by the drive shaft of the motor vehicle which is the modification 1 of an Example. It is a left view which shows the dynamic damper. It is sectional drawing of the VV line direction of FIG. 6 which shows the dynamic damper inserted by the drive shaft of the motor vehicle which is the modification 2 of an Example. It is a left view which shows the dynamic damper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Dynamic damper, 11 ... Mounting metal fitting, 12 ... Flange part, 13 ... Center axis metal fitting, 14 ... Mass metal fitting, 16 ... Rubber elastic body, 17 ... Axial rubber part, 18 ... Straight part, 21 ... Rubber coating layer, 23 ... Tickling part, 24 ... Rubber connecting part.

Claims (5)

A plate-like mounting bracket that is inserted into the mating pipe member by press fitting and fixed in a state perpendicular to the axial direction of the mating pipe member;
A central shaft bracket fixed vertically on one side of the mounting bracket and extending vertically;
A cylindrical mass fitting disposed radially outward of the central shaft fitting and spaced apart from the central shaft fitting and the mounting bracket;
A rubber elastic body that elastically connects between the central shaft fitting and the mass fitting;
A dynamic damper comprising a pair of straight portions extending in the axial direction on both sides in the radial direction across the central shaft fitting of the rubber elastic body. The dynamic damper according to claim 1, wherein the straight portion penetrates the rubber elastic body in an axial direction. 3. The axial rubber portion that extends in an axial direction from the rubber elastic body and connects between the mounting bracket and an end face of the mass fitting facing the mounting bracket, is provided. Dynamic damper. 4. The dynamic according to claim 1, wherein the mounting bracket is provided with a flange portion extending in an axial direction at an outer peripheral edge that contacts an inner peripheral surface of the mating pipe member. 5. damper. The dynamic damper according to any one of claims 1 to 4, wherein a surface of the mounting bracket is covered with a thin rubber coating layer.

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