JP2001063307A - Hollow drive shaft for front-wheel-drive vehicle and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce weight as a hollow structure, eliminating the process of hardening by work hardening, and reduce noise generated at the time of rotation by forming a hollow drive shaft composed of a pipe material, forming both ends of the hollow drive shaft as a small diameter shaft part having a wall thickness by diameter contracting work, and applying work hardening by thinly forming a part formed between the small diameter shaft parts by means of ironing. SOLUTION: In one end of a pipe material 1, its outer diameter is contracted by dies so as to form a small diameter shaft part 3, and its wall thickness is set to about 4.5 to 5.0 mm. A core metal is inserted tightly as possible from the other end side of the pipe material 1, and ironing is carried out so as to set the wall thickness of the pipe material 1 to about 1.5 to 2.0 mm by dies remaining a range having a prescribed length on the other end part side. After that, the core metal is drawn out, and the diameter of a wall thickness part of the other end of the pipe material 1 is contracted in the same way as the case of the small diameter shaft part 3 by the dies so as to form a small diameter shaft part 7. Serrations 8, 9 for connecting to a front wheel driving system are worked on outer peripheral parts of the small diameter shaft parts 3, 7. It is thus possible to provide a hollow driven shaft wherein work hardening is applied by ironing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a drive shaft for a front wheel drive vehicle, and more particularly to a hollow drive shaft and a method for manufacturing the same.

[0002]

2. Description of the Related Art In a front-wheel drive type automobile, rotation output through an output shaft of an engine is transmitted to left and right front wheels through left and right drive shafts, respectively, so that the vehicle travels.

A conventional drive shaft for driving a front wheel is a product obtained by cutting a hollow rod-shaped steel material into a predetermined shape and then hardening the surface.

[0004]

However, in the above-mentioned conventional drive shaft, the round bar material is cut and then subjected to surface quenching (induction quenching), so that processing takes a considerable amount of time and not only increases the cost, but also increases the cost. Since the weight is increased, there is a problem in that the weight of the vehicle body is prevented from being reduced, and noise is easily generated when transmitting rotation.

SUMMARY OF THE INVENTION In view of the above, the present invention achieves weight reduction by using a hollow drive shaft for a front-wheel drive vehicle, and at the same time eliminates the need for quenching by work hardening, thereby reducing man-hours and achieving mass production. Another object of the present invention is to reduce noise during rotation.

[0006]

As a means for solving the above-mentioned problems, the present invention relates to a pipe made of a pipe material, whose both ends are reduced in diameter to form small-diameter shafts, and the small-diameter shafts are thinned by ironing. A hollow drive shaft of a front wheel drive vehicle, which is formed to have work hardening,
And forming a small-diameter shaft portion by reducing the diameter of one end of the pipe material with a die, and inserting the core metal as tightly as possible from the other end of the pipe material after reducing the diameter of one end and the other end of the pipe material. A process of ironing the outer periphery excluding the required length range to a predetermined thickness, and forming a small-diameter shaft portion by reducing the diameter of the other end remaining as a pressed wall after the ironing by a die. And manufacturing the hollow drive shaft of the front wheel drive vehicle. The ironing process in the above manufacturing is preferably performed with an ironing amount that gives a margin extending in the circumferential direction of the pipe material, in order to obtain a shaft that is strong against twisting.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1A is a cross-sectional view of a pipe material 1 used in the present invention, and FIG. 1B shows a case where a bonderite treatment (thinning treatment) is applied to an intermediate portion of the pipe material 1 excluding both ends. FIG. However, this bonderite processing need not necessarily be performed, but the following description shows the case where the pipe material 1 of FIG. 1B is used.

The material of the pipe member 1 is JIS
Using STKM (carbon steel), tensile strength 35 kg / mm ² -8
0 kg / mm ² is used. The outer diameter D of the pipe material 1
Is 40 to 45φ, thickness T is 3 to 5 mm, and length L is 400 to
It is about 600 mm.

As shown in FIG. 2, one end 1A of the pipe member 1 is formed into a small-diameter shaft portion 3 by using a die 2 to reduce the outer diameter d to 25 ± 5 mm. At this time, the thickness t of the small diameter shaft portion 3
₁ is 4.5 to 5.0 mm.

[0011] Then, leaving the range of the other end 1B side of the pipe member 1 as much as possible tightly inserting the core metal 4, the predetermined its end 1B side of the length L ₁ as shown in FIG. 3 the die 5 Thickness t
Ironing is performed so that ₂ is 1.5 to 2.0 mm.
In this processing, the thickness t ₂ is determined by the cored bar 4 and the die 5, so that the thickness t ₂ is accurately and uniformly formed. At this time, the ironing amount is set to such an extent that a margin extending in the circumferential direction of the pipe material 1 remains.

Thereafter, the mandrel 4 is removed and the other end 1 of the pipe material 1 is removed.
The small-diameter shaft portion 7 is formed by reducing the diameter of the thick portion left in B in the same manner as in the case of the small-diameter shaft portion 3 as shown in FIG.

As shown in FIG. 5, serrations 8, 9 for connection to the front wheel drive system are formed on the outer periphery of the small diameter portions 3, 7, respectively.

As a result, both ends become small-diameter shaft portions 3 and 7,
A hollow drive shaft having a work hardened between the small diameter shaft portions 3 and 7 by ironing is obtained. Since the hollow drive shaft thus obtained is work-hardened as described above, it is not necessary to perform induction hardening, and it is only necessary to perform additional processing such as shot peening if necessary. By providing a margin that can extend in the circumferential direction of the pipe material 1 during the ironing process, a structure that is strong in the torsional direction can be obtained.

[0015]

As described above, according to the present invention, since the drive shaft of the front wheel drive vehicle has a hollow structure, the weight of the portion can be greatly reduced and no noise is generated during rotation. . Also, in manufacturing, it can be obtained by reducing the diameter with a die and ironing, so there is no need for precise cutting, etc. In addition, the hardness increases by work hardening by ironing, and the induction hardening that was conventionally essential is also unnecessary. Man-hours can be significantly reduced, mass production is possible, and it can be obtained at low cost. Further, since the small-diameter shaft portions at both ends are thick, it is possible to carry out necessary post-processing such as serration on the outer periphery without any trouble, and it is possible to secure sufficient strength.

[Brief description of the drawings]

FIG. 1 shows a pipe material used in the present invention;
(A) is a cross-sectional view, and (B) is a cross-sectional view when a bonderite process is performed.

FIG. 2 is a sectional view showing a step of forming a small-diameter shaft portion at one end of a pipe material.

FIG. 3 is a cross-sectional view illustrating an ironing process of an intermediate portion of a pipe material.

FIG. 4 is a sectional view showing a step of forming a small-diameter shaft portion at the other end of the pipe member.

FIG. 5 is a front view showing the completed hollow drive shaft.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe material 2, 5, 6 Die 3, 7 Small diameter shaft part 4 Core metal 8, 9 Serration

Claims (3)

[Claims] 1. A small-diameter shaft portion made of a pipe material and having both ends formed by reducing the diameter to form a small-diameter shaft portion. The small-diameter shaft portion is formed to be thin by ironing to provide work hardening. The hollow drive shaft of a front wheel drive vehicle. 2. A process of reducing the diameter of one end of a pipe material by a die to form a small-diameter shaft portion, and reducing the diameter of one end and inserting a core metal as tightly as possible from the other end of the pipe material. Ironing the outer periphery of the other end of the material excluding the required length range to a predetermined thickness, and reducing the diameter of the other end left as a thick wall after the ironing by using a die to reduce the diameter. Forming a shaft portion. 14. A method of manufacturing a hollow drive shaft for a front wheel drive vehicle, comprising: 3. The method of manufacturing a hollow drive shaft for a front wheel drive vehicle according to claim 2, wherein the ironing is performed by an ironing amount that gives a margin extending in a circumferential direction of the pipe material.