JPS60168913A - Hollow drive shaft - Google Patents

Abstract

PURPOSE:To make it possible to effectively cope with vibrations or noises by making the natural frequency changeable without providing any different member such as a rubber damper, etc. by means of forming convex or concave lines in the cicumferential direction on a hollow shaft body in part. CONSTITUTION:A hollow drive shaft 10 is formed as one body using a metallic pipe. After the shaft body 10a is made solid at both ends of it, non-rotation sections 11, 12 are made around this solid portions. Around the shaft body 10a, convex lines 15, for example, are formed in the circumferential direction in a proper number along the axial direction of the shaft. The locations and number of the convex lines 15 are set effectively in terms of preventing the resonance. In this way, it is possible to change the natural frequency of the drive shaft 10 without using any different member such as a rubber damper, etc. and the occurrence of resonance can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a hollow drive shaft used as a wheel drive shaft of an automobile.

[Technical background of the invention and its problems]

A drive shaft used in an automobile is provided between a drive-side member 1 and a wheel-side member 2, as shown in FIG. 1, for example. Then, it rotates while receiving torque from the drive source and transmits the driving force to the wheels 3. For this reason, the drive shaft IO tends to generate torsional vibration, bending vibration, etc., and when this vibration matches the natural frequency of the drive system including the drive shaft, resonance occurs, causing noise.

For this reason, conventionally, in order to prevent resonance from occurring within the practical rotational speed range of the drive shaft, a rubber damper 4 was attached to the main body 10m of the drive shaft to change the natural frequency, as shown in FIG. Or by changing the diameter of the shaft body in various ways, the natural frequency is adjusted to prevent resonance.

However, when the rubber damper 4 is used as described above, there are problems in that the number of parts increases and additional space is required for mounting the damper. On the other hand, in order to prevent resonance by varying the diameter of the drive shaft, it is necessary to prepare many types of drive shafts, and moreover, a large number of trial manufacturing steps and tests must be performed for each size. Problems arose, such as the heavy burden required for prototyping.

[Purpose of the invention]

The present invention was made based on the above-mentioned circumstances, and its object is to provide a hollow drive shaft whose natural frequency can be changed without attaching a separate member such as a rubber damper.

[Summary of the invention]

The gist of the present invention resides in a hollow drive shaft in which a circumferential protrusion or groove is integrally formed in a part of a hollow shaft main body.

According to the above configuration, the natural frequency can be adjusted by appropriately selecting the position, number, etc. of the protruding stripes or four stripes. These convex or concave lines can be formed into a desired number and position by rolling or other plastic working. Therefore, there is no need for separate parts such as the conventionally used rubber bumpers, the number of parts does not increase, and even the same drive shaft can be given various natural frequencies, resulting in resonance. It is extremely effective in preventing the occurrence of

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. Figure 3 shows the hollow drive shaft 10
It shows. The drive shaft 10 is integrally formed from a metal pipe such as a steel pipe. For more details,
After cutting both ends of the metal pipe to a predetermined length using a swaging machine or the like, the main body part 1 is
Terminal section 10b located at both ends of 0 m.

10b is made into a solid material by hot age setting processing or the like.

Then, detent portions 11 and 12 are provided on the solid portion by serration processing by rolling or by forming splines. Note that the terminal section 1
Induction hardening is performed from 0b, 10b to the shaft body portion 10a.

Further, 13 and 14 are boot grooves. These boot grooves 1
3.14, the ends of rubber boots 5, 6 for dust protection, as illustrated in FIG. 1, are fixed.

As illustrated in FIG. 4, an appropriate number of protrusions 15 extending along the circumferential direction are formed in the shaft main body 10a in the axial direction.

The positions and number of the protrusions 15 are set to be effective in preventing resonance.

That is, the state before forming the protrusions 15 (see Fig. 3) is mounted on a bench and on an actual vehicle, and tests are conducted to check the vibration generation status, etc., and the presence or absence of resonance is investigated. . If resonance occurs, one protrusion I5 is formed by rolling or other appropriate plastic working, and the number of protrusions I5 is increased until resonance no longer occurs. Further, the same test as above is performed by changing the position where the protrusion 15 is provided, and the position considered to be most effective in preventing resonance is found. Note that the natural frequency can also be changed by forming grooves instead of protrusions.

If you find the optimal position and number of protrusions or concave strips through the above test, then
For car models, etc., resonance can be prevented in the practical rotation speed range.

Therefore, drive shafts with common specifications determined as described above may be installed in common vehicle models.

Note that if the resonance reference changes due to a change in vehicle type, etc., the position, number, etc. of the protrusions or concave lines must be reset in accordance with this change. However, in this case as well, it is only necessary to change the position, number, etc. of the protrusions or grooves, and there is no need to change the basic dimensions, shape, etc. of the drive shaft itself.

Therefore, according to the hollow drive shaft, there is no need to change the /4' iso size, which is required in the case of conventional drive shafts, in order to prevent the occurrence of resonance, and the burden required for prototyping is greatly reduced. Further, there is no increase in the number of parts as seen in the conventional damper system illustrated in FIG. 2, and this is an extremely effective means for suppressing noise and photographing peculiar to drive shafts.

In addition, although the above embodiment describes an integral hollow drive shaft manufactured from a single pipe, the present invention is not limited to this. For example, a hollow shaft main body and solid terminal parts located at both ends of the shaft are manufactured separately.
Of course, the present invention can also be applied to a separate hollow drive shaft in which these parts are connected to each other by friction welding or caulking. Moreover, the protruding stripes or the concave stripes may have a spiral shape.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to effectively deal with noise, vibration, etc. peculiar to drive shafts with a simple structure without increasing the number of parts.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing a wheel drive unit of an automobile, Fig. 2 is a side view showing a conventional drive shaft with rubber bumper A attached, and Fig. 3 is a cross-sectional view of a part of the hollow drive shaft used in the present invention. Side View FIG. 4 is a side view partially in section showing one embodiment of the present invention. DESCRIPTION OF SYMBOLS 10... Hollow drive shaft, 10a... Shaft body part, I5... Convex line or concave line.

Claims (1)

[Claims] A hollow drive shaft characterized in that a circumferentially extending convex or concave line is integrally formed in a part of a hollow shaft main body.