JPS60251220A - Production of outside cylinder for uniform joint - Google Patents

Abstract

PURPOSE:To produce an outside cylinder for a uniform joint having required characteristics without subjecting said cylinder to a hardening and tempering treatment by subjecting a controlled rolling material which is made into a finely sized structure state to warm forging at a specific temp. and to finishing by cold ironing then subjecting the prescribed section thereof to high-frequency hardening. CONSTITUTION:The blank material which is made into the finely sized structure state by controlled rolling is heated to the temp. below 600-720 deg.C A1 transformation point by a heating means such as high-frequency heating and is subjected to warm forging. The material is then allowed to cool and is finished by cold ironing so that the necessary parts accuracy is assured. Ironing can be executed at about 20% average ironing rate with a carbon steel contg. about 0.4-0.5% carbon by weight in this state. The section of the outside cylinder of the uniform joint for which wear resistance is required is further subjected to high-frequency hardening to harden the surface. The stage for production is thus reduced and the outside cylinder for the uniform joint is produced at a low cost.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for manufacturing a constant velocity joint outer cylinder, and more specifically, in manufacturing a conventional constant velocity joint outer cylinder, the following steps are required after hot forging. Manufacture of a constant velocity joint outer cylinder that can secure the necessary characteristics as a constant velocity joint outer cylinder even if quenching and tempering treatment is abolished, and that can reduce manufacturing costs by shortening the manufacturing process. It depends on the method.

[Prior art]

Conventionally, constant velocity joint outer cylinder (Gl type, BJ type,
In the production of DOJ type, REBRO type, etc., carburizing and induction hardening treatments are generally used as a means to harden the surface of race surfaces such as roller grooves or ball grooves that require wear resistance. .

When the surface of the constant velocity joint outer cylinder where wear resistance is required as described above is hardened by induction hardening, a carbon steel material such as JIS standard 543C to 555C is used, and after hot forging, annealing is performed. It was usual to perform hardening and tempering, then machine the entire surface of the material, then induction hardening and low temperature tempering, and finally finish by grinding.

This is because if polishing of the race surface after hot forging and induction hardening is abolished, surface decarburization during the quenching and tempering process is unavoidable, making it impossible to ensure surface hardness.

In addition, when manufacturing a constant velocity joint outer cylinder without machining the race surface, it is important to adjust the atmosphere during the quenching and tempering treatment to be non-decarburized and non-carburized.
There was a problem in that it was difficult to control.

Incidentally, recently, attempts have been made to ensure component accuracy by cold ironing after warm forging or hot forging, and to eliminate machining of race surfaces such as roller grooves and ball grooves.

However, this manufacturing method has the problem that if decarburization or carburization is involved during the quenching and tempering process, the quality of induction hardening on race surfaces such as roller grooves and ball grooves in the subsequent process will not be stable. .

For this reason, although attempts have been made to perform quenching and tempering treatment after hot forging in a non-oxidizing atmosphere, it is difficult to completely prevent some decarburization and carburization, and In order to completely prevent carburization, etc., atmospheric gas is used and sufficient atmosphere control is required.
There was a problem in that heat treatment costs rose significantly.

[Purpose of the invention]

The present invention was made in order to solve the problems of the prior art as described above, and the parts of the constant velocity joint outer cylinder where wear resistance is required are surface hardened by induction hardening. In the method of manufacturing a constant velocity joint outer cylinder, even if the quenching and tempering treatment, which was essential in the production of constant velocity joint outer cylinders using the conventional hot forging method, is abolished, the inner part necessary for a constant velocity joint outer cylinder is Hardness HV20
0 or more) 1. It is possible to secure induction hardening characteristics such as surface hardness and induction hardening depth, as well as excellent induction hardening distortion characteristics, and furthermore, it is possible to shorten the manufacturing process and reduce manufacturing costs. The purpose of the present invention is to provide a method for manufacturing a constant velocity joint outer cylinder that can be used.

[Structure of the invention]

According to the present invention, this purpose is to improve the race surface and other parts of the constant velocity joint outer cylinder that require wear resistance.
A method for manufacturing a constant velocity joint outer cylinder whose surface is hardened by induction hardening, using a material that has been made into a fine grained structure by controlled rolling, and by heating means such as high frequency heating.
A of 00 to 720℃, heated to a temperature below the transformation point, cooled to warm forging temperature, and then cold-finished to ensure the necessary part precision, and then tested for wear resistance in the constant velocity joint outer cylinder. This is achieved by a method for manufacturing a constant velocity joint outer cylinder, which is characterized in that the portions where this is required are subjected to induction hardening to harden the surface.

[Action of the invention]

Hereinafter, the effects of the present invention will be explained.

The manufacturing process of a constant velocity joint outer cylinder according to the method of the present invention is shown in FIG. 1 in comparison with a conventional process.

A feature of the method of the present invention is that whereas hot-rolled materials were used in the conventional process, the method of the present invention uses so-called controlled-rolled materials, which are rolled by controlling the billet temperature. In addition, the forging method is a warm forging method compared to the conventional hot forging method.

The reason for using a controlled-rolled material here is that by using a controlled-rolled material, it is possible to secure an internal hardness of Hv200 or more, which is necessary for a constant-velocity joint outer cylinder, and at the same time, it is possible to ensure a fine-grained material suitable for induction hardening. This is because it is possible to form a granular structure.

The warm forging temperature is preferably 600 to 720° C., which is below the transformation point, by heating means such as high frequency heating.

When warm forging is performed in this temperature range, the material hardly transforms into a two-phase region, so the fine grained structure of the material is maintained, and the induction hardening characteristics during induction hardening performed in the subsequent process are improved. This is because it becomes uniform, the necessary induction hardening depth can be secured, and excellent induction hardening distortion can be achieved.

That is, A. If the temperature is higher than the transformation point, this is undesirable because it induces structural transformation and changes the material structure.

In addition, the reason why the warm forging temperature is below the A1 transformation point of 600 to 720°C is that within this warm forging temperature range,
This is because after warm forging, it is possible to ensure the same internal hardness as when quenching and tempering treatment is performed after hot forging.

Note that if the temperature is lower than 600℃, work hardening occurs during warm forging, and cracks are likely to occur during the cold ironing process in the subsequent process, but if cracking is not a problem, this manufacturing method can also be used at temperatures below 600℃. It goes without saying that it is possible to apply

Next, in the method of the present invention, a cold ironing finish is performed without performing quenching and tempering treatment, but this is because the roller grooves and balls in which the rollers and balls of the constant velocity joint outer cylinder roll, This is to ensure the accuracy of the race surfaces such as grooves and the inner and outer profiles of the cup.

Although the ironing required for finishing by cold ironing differs depending on the warm forging temperature and the material, if the carbon steel has a carbon content of 0.4 to 0.5% by weight, the average ironing rate is 20.
% ironing process is possible, and therefore sufficient accuracy of the race surface can be ensured.

As a result of the above, according to the method for manufacturing a constant velocity joint outer cylinder of the present invention, machining of the race surface and inner and outer profiles can be made unnecessary in manufacturing the constant velocity joint outer cylinder. be.

〔Example〕

Hereinafter, the present invention will be described in detail based on the accompanying drawings.

The processing steps of the method of the present invention will be specifically explained based on the first embodiment of manufacturing a constant velocity joint outer cylinder shown in FIG.

The material used was a controlled rolled material of JIS standard 545C that had been subjected to beering, the material hardness was in the range of Hv 180 to 220, and the ferrite crystal grain size was 7 or more.

Then, this material is cut into a size suitable for manufacturing a constant velocity joint outer cylinder.

Thereafter, shot blasting was performed as necessary to clean the surface of the material, and after preheating to 100 to 150 DEG C., graphite coating was applied.

Then, it was heated before warm forging using a high-frequency heating device.

The heating temperature for warm forging at this time was A, and the maximum temperature of the material was 720°C so as not to exceed the transformation point.

Next, after heating before warm forging, the four steps shown in FIG. 3 were performed by warm forging in the order of (a), (b), (c), and (d).

After warm forging in this manner, it was subjected to shot blasting treatment, and was further lubricated with Bonderite and Bonda Lube.

Thereafter, the inner and outer profiles of the constant velocity joint outer cylinder cup portion, and the race surfaces such as roller grooves and ball grooves were finished by cold machining.

Next, after machining the necessary parts, induction hardening and low-temperature tempering were performed, and finally, the shaft was ground to form the finished constant velocity joint outer cylinder.

4 and 5 show other embodiments of constant velocity joint outer cylinders that can be manufactured by applying the method of the present invention.

The manufacturing process is shown in FIGS. 2 and 3 and is the same as the manufacturing process of the constant velocity joint outer cylinder in the first embodiment, so a description thereof will be omitted.

〔Effect of the invention〕

As is clear from the above, according to the method for manufacturing a constant velocity joint outer cylinder according to the present invention, the parts of the constant velocity joint outer cylinder that require wear resistance are surface hardened by induction hardening. In the method of manufacturing a constant velocity joint outer cylinder, even if the quenching and tempering treatment, which was essential in the production of constant velocity joint outer cylinders using the conventional hot forging method, is abolished, the inner part necessary for a constant velocity joint outer cylinder is Hardness.

It is possible to secure induction hardening characteristics such as surface hardness and induction hardening depth, as well as excellent induction hardening distortion characteristics.Moreover, it is possible to shorten the manufacturing process and significantly reduce manufacturing costs. There are advantages

[Brief explanation of the drawing]

Figure 1 is a comparison of the constant velocity joint outer cylinder manufacturing process between the method of the present invention and the conventional method. FIG. 2 is a diagram showing the constant velocity joint outer cylinder of the first embodiment. FIG. 3 is an explanatory diagram showing the warm forging process of the constant velocity joint outer cylinder of the first embodiment. FIGS. 4 and 5 are diagrams showing other embodiments to which the method of the present invention can be applied. Dee Kaito Toyota Motor Vehicle 1 (Kizumi Figure 2 Figure 3)

Claims (1)

[Scope of Claims] 1. A method for manufacturing a constant velocity joint outer cylinder in which parts of the constant velocity joint outer cylinder that require wear resistance, such as race surfaces, are hardened by induction hardening, the method comprising: by controlled rolling; Using a material with a finely sized structure, it is heated to an A temperature of 600 to 720℃ using heating means such as high frequency heating.
After heating to a temperature below the transformation point, allowing it to cool after warm forging, and then ensuring the necessary part accuracy through cold processing and finishing, parts of the constant velocity joint outer cylinder that require wear resistance are On the other hand, a method for manufacturing a constant velocity joint outer cylinder, which is characterized by surface hardening by induction hardening.