JP2014088908A - Dynamic damper - Google Patents

Abstract

An object of the present invention is to prevent the occurrence of rust on the outer peripheral surface of a driving force transmission shaft by preventing foreign matter such as moisture and dust from entering a dynamic damper attached to the driving force transmission shaft. Provided is a dynamic damper capable of improving performance.
A main body portion 5a is provided with mounting portions 5d and 5e that are externally fitted to a driving force transmission shaft 2 on one end side and the other end side in the axial direction. A mass portion 5b that accommodates the weight 7 and protrudes radially outward, supports the mass portion 5b at both axial ends, and between the outer peripheral surface of the driving force transmission shaft 2 and the inner peripheral surface of the mass portion 5b. A support portion 5c that forms an annular space 6. The support portion 5c is made of an elastic member, and elastically deforms the support portion 5c to support the mass portion 5b so as to vibrate in the radial direction. In the dynamic damper 5 that attenuates the vibration 2, the annular space 6 is provided with a low-hardness elastic member 6 a that does not hinder the elastic deformation of the support portion 5 c without a gap.
[Selection] Figure 2

Description

  The present invention relates to a dynamic damper attached to a driving force transmission shaft such as a drive shaft of an automobile.

  A dynamic damper is attached to a driving force transmission shaft such as a drive shaft of an automobile in order to suppress vibrations such as bending vibration and torsional vibration generated when the driving force is transmitted. The dynamic damper includes a main body portion in which a through-hole through which the drive shaft is inserted is formed, and a mounting portion that is externally fitted to the drive shaft on one end side and the other end side in the axial direction. The main body portion is formed in a substantially cylindrical shape, and includes a mass portion that accommodates a weight and protrudes radially outward, and a support portion that supports the mass portion at both ends in the axial direction. An annular space is formed between the outer peripheral surface of the drive shaft and the inner peripheral surface of the mass portion, the support portion is made of an elastic member, and the mass portion can be vibrated in the radial direction by the elastic deformation of the support portion and the annular space. I support it. Then, by resonating the vibration generated with the rotation of the drive shaft with the vibration of the mass portion of the dynamic damper, the vibration energy is absorbed and the vibration at the time of driving force transmission is attenuated.

  By the way, in the case of a drive shaft of an automobile equipped with such a dynamic damper, since it is installed in a state exposed to the outside at the bottom of the vehicle body, foreign matters such as water droplets and dust are directly applied to the dynamic damper by running in the rain. It will be. For this reason, foreign matter such as moisture and dust is transferred from the space between the outer peripheral surface of the drive shaft and the axial end portions of the dynamic damper to the annular space formed between the drive shaft and the mass portion of the dynamic damper. It may gradually invade and remain. This residual foreign matter may lead to corrosion of the drive shaft due to deterioration of the dynamic damper or generation of rust over time. For this reason, the outer peripheral surface of the drive shaft is provided with a rust-proof coating that prevents the occurrence of rust. The rust prevention effect may be reduced. For example, Patent Document 1 discloses a technique in which a groove is formed on the outer peripheral surface of a drive shaft, and foreign matter that has entered between the dynamic damper and the drive shaft is discharged through the groove.

JP 2008-207608 A

  However, in the conventional technique described in Patent Document 1, since the groove is formed on the outer peripheral surface of the drive shaft, the rigidity of the drive shaft may be reduced. In addition, since the groove is formed on the outer peripheral surface of the drive shaft, there is a problem that the groove is not sufficiently coated with the rust and the rust preventive effect cannot be obtained.

  The present invention has been made to solve the above problems, and the problem to be solved by the present invention is that foreign matters such as moisture and dust enter the dynamic damper attached to the driving force transmission shaft. It is an object of the present invention to provide a dynamic damper capable of suppressing the occurrence of rust on the outer peripheral surface of the driving force transmission shaft and improving the durability of the driving force transmission shaft.

  The invention according to claim 1 includes: a main body portion in which a through-hole through which the driving force transmission shaft is inserted is formed; and a mounting portion that is externally fitted to the driving force transmission shaft on one end side and the other end side in the axial direction. The main body portion is formed in a substantially cylindrical shape, accommodates a weight and protrudes radially outward, supports the mass portion at both axial ends, and an outer peripheral surface of the driving force transmission shaft And a support portion that forms an annular space between the inner peripheral surface of the mass portion, the support portion is made of an elastic member, and the mass portion is vibrated in the radial direction by elastic deformation of the support portion. In the dynamic damper for supporting and damping the vibration of the driving force transmission shaft, the annular space is provided with a low-hardness elastic member that does not hinder the elastic deformation of the support portion without any gap. To do.

  According to the invention of claim 1 configured as described above, the dynamic damper attached to the driving force transmission shaft is formed in the annular space between the support portion, the outer peripheral surface of the driving force transmission shaft, and the inner peripheral surface of the mass portion. Since the elastic member is arranged without a gap, it is possible to prevent intrusion of foreign matter. Since this elastic member is a low-hardness elastic member that does not hinder elastic deformation of the support portion, the support portion can support the mass portion so as to vibrate in the radial direction by elastic deformation. The dynamic damper can attenuate the vibration of the driving force transmission shaft by vibrating the mass portion in the radial direction, that is, by resonance. Therefore, without impairing the function of attenuating the vibration of the dynamic damper, it is possible to suppress the generation of rust on the outer peripheral surface of the driving force transmission shaft and improve the durability of the driving force transmission shaft.

  According to the present invention, the generation of rust on the outer peripheral surface of the driving force transmission shaft is suppressed by preventing the entry of foreign matter such as moisture and dust into the dynamic damper attached to the driving force transmission shaft. A dynamic damper capable of improving the durability of the shaft can be provided.

It is a side view which shows a drive shaft as a driving force transmission axis concerning an embodiment of the present invention partially in section. It is sectional drawing which shows the dynamic damper which concerns on embodiment of this invention.

Hereinafter, a dynamic damper according to an embodiment of the present invention will be described with reference to the drawings.
In this embodiment, the dynamic damper is mounted on a drive shaft that transmits driving force from the differential of the automobile to the wheels.

  As shown in FIG. 1, the drive shaft 1 is provided with an inboard joint 3 on one end side of an intermediate shaft 2 that is a driving force transmission shaft and an outboard joint 4 on the other end side of the intermediate shaft 2. It is configured.

  The inboard joint 3 of the drive shaft 1 is connected to a differential (not shown), and the outboard joint 4 of the drive shaft 1 is connected to a wheel mounting hub unit (not shown). It has become so.

  The inboard joint 3 is a tripod type constant velocity joint. Further, the outboard joint 4 is a Barfield type constant velocity joint.

The dynamic damper 5 is attached to an intermediate region in the axial direction of the intermediate shaft 2 of the drive shaft 1.
The dynamic damper 5 is mounted in the region between the inboard joint 3 and the outboard joint 4 in the intermediate shaft 2 to absorb vibration energy of the drive shaft 1 by resonance and absorb vibration of the drive shaft 1. It is to suppress.

  The dynamic damper 5 is a so-called shear type dynamic damper, and is externally fitted to the intermediate shaft 2 at one end side and the other end side in the axial direction, and a main body portion 5a in which a through hole 5f through which the intermediate shaft 2 is inserted is formed. Mounting portions 5d and 5e.

  As the dynamic damper 5 resonates with the natural vibration of the drive shaft 1, the vibration energy of the drive shaft 1 is absorbed and the vibration is attenuated.

  As shown in FIG. 2, the main body 5a includes a mass portion 5b and a support portion 5c that supports the mass portion 5b. The main body 5a is formed in a substantially cylindrical shape. The mass portion 5b accommodates the weight 7 and protrudes outward in the radial direction. The support part 5c supports the mass part 5b at both axial ends of the mass part 5b. Thereby, the annular space 6 is formed between the outer peripheral surface of the intermediate shaft 2 and the inner peripheral surface of the mass part 5b.

  The mass portion 5b and the support portion 5c are made of an elastic member, and are formed of a rubber material having elasticity, a synthetic resin material having elasticity, or the like. Due to the elastic deformation of the support portion 5c, the mass portion 5c can vibrate in the radial direction.

  The weight 7 is made of a metal material such as aluminum, iron and various alloys, or an appropriate resin, and is embedded in the mass portion 5b by vulcanization molding. In addition, the weight 7 is managed in such a mass that the vibration of the drive shaft 1 is attenuated by resonance in consideration of the natural frequency according to the specification of the drive shaft 1 to which the dynamic damper 5 is mounted.

  In the annular space 6, for example, a low-hardness elastic member 6 a such as silicon rubber is disposed without a gap. The elastic member 6a is softer than the elastic member of the support portion 5c, and is a low-hardness elastic member 6a that does not hinder the elastic deformation of the support portion 5c. Therefore, the support portion 5c causes the mass portion 5b to move in the radial direction by elastic deformation. It can be supported so that it can vibrate. Further, the joint surfaces of the elastic member 6a and the elastic member 6a of the mass part 5b and the support part 5c are brought into close contact with an adhesive or the like so that no gap is formed even if the support part 5c is elastically deformed.

  The mounting portions 5 d and 5 e have an inner diameter that is substantially the same as the outer diameter of the intermediate shaft 2. The mounting portions 5 d and 5 e are externally fitted to the intermediate shaft 2 on one end side and the other end side in the axial direction and are tightened and attached by a fastening member 8. The fastening member 8 is formed in an annular shape, is made of an elastic material, and has a structure that can expand and contract in the radial direction. In this way, the dynamic damper 5 is mounted in a state of being axially positioned with respect to the intermediate shaft 2 of the drive shaft 1.

  According to the dynamic damper 5 configured as described above, the drive shaft 1 is installed in a state of being exposed to the outside at the bottom of the vehicle body, so that foreign matters such as water droplets and dust are caused to the dynamic damper 5 by running in the rain. It will take directly.

  For this reason, foreign matters such as moisture and dust are between the intermediate shaft 2 and the mass portion 5b of the dynamic damper 5 between the outer peripheral surface of the intermediate shaft 2 and the mounting portions 5d and 5e at both axial ends of the dynamic damper 5. However, since the elastic member 6a is disposed in the annular gap 6 without any gap, entry of foreign matter can be prevented.

  Since the elastic member 6a is a low-hardness elastic member 6a that does not hinder the elastic deformation of the support portion 5c, the support portion 5c can support the mass portion 5b so as to vibrate in the radial direction by elastic deformation. The dynamic damper 5 can attenuate the vibration of the drive shaft 1 by vibrating the mass portion 5b in the radial direction, that is, by resonance.

  Thereby, the generation | occurrence | production of the rust of the drive shaft 1 outer peripheral surface can be suppressed and the durability of the drive shaft 1 can be improved, without impairing the function which attenuates the vibration of the dynamic damper 5.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope of the invention described in the claims. For example, in this embodiment, an example is given in which a dynamic damper is applied to a drive shaft that is a driving force transmission shaft of an automobile, but it is applied to a driving force transmission shaft that is used in an automobile propeller shaft and various machine tools and devices. can do.

1: drive shaft, 2: intermediate shaft, 5: dynamic damper,
5a: body part, 5b: mass part, 5c: support part, 5d, 5e: mounting part,
5f: through hole, 6: annular space, 6a: elastic member, 7: weight, 8: fastening member

Claims (1)

A main body formed with a through hole through which the driving force transmission shaft is inserted;
A mounting portion fitted on the driving force transmission shaft at one end side and the other end side in the axial direction;
The main body is formed in a substantially cylindrical shape,
A mass part that accommodates the weight and protrudes radially outward;
While supporting the mass part at both axial ends,
A support portion that forms an annular space between an outer peripheral surface of the driving force transmission shaft and an inner peripheral surface of the mass portion;
Consisting of
In the dynamic damper, wherein the support portion is made of an elastic member, and the mass portion is supported so as to be able to vibrate in a radial direction by elastic deformation of the support portion, and the vibration of the driving force transmission shaft is attenuated.
The dynamic damper, wherein the annular space is provided with a low-hardness elastic member that does not hinder the elastic deformation of the support portion without a gap.

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