KR20060018945A - Wheel shaft production method - Google Patents

Abstract

The present invention relates to a hollow wheel shaft manufacturing method, and in particular, in the manufacture of the hollow wheel shaft to the gear mechanism of the rotational movement of the steering wheel, annealing, short and bond the material cut to the appropriate length to increase the ductility rust After removal, the film is formed on the surface, and the cold forging process is performed by pressing the material several times according to the shape of the product to form a stepped part in a plurality of places, and the serration process, the polishing and the rolling process are performed on both sides of the material. By manufacturing the gear part while serration processing at the end, and forming the bearing insert part at the middle part, manufacturing a hollow wheel shaft that can reduce equipment investment cost, improve product productivity and expect cost reduction effect. It is about a method.

Hollow wheel shaft, press, cold forging,

Description

Hollow wheel shaft production method

1 is a cross-sectional view showing a hollow wheel shaft of the present invention.

Figure 2 (a) ~ (e) is a view showing the manufacturing process of the present invention.

Explanation of symbols for main parts of the drawings

1: middle part, 2a, 2b: first double stepped part,

3: second step, 4: third step,

5: insert, 6: first serration,

7: gear part, 8: second serration,

9: bearing insert,

The present invention relates to a hollow wheel shaft manufacturing method, and more particularly to a method of manufacturing a hollow wheel shaft to reduce the equipment investment cost, improve the productivity of the product as well as to expect the effect of cost reduction.

In general, the wheel shaft is a function of transmitting the rotational movement of the steering wheel to the steering gear mechanism, and is installed between the steering column and the gearbox in the component layout of the vehicle.

Such a wheel shaft is formed in a hollow shape as shown in FIG. 1 and is provided with a plurality of step portions as a whole, and serrations are formed at both ends inside or outside, and a gear part is formed at one end portion outer circumferential surface thereof.

Conventionally, a hollow wheel shaft is manufactured by a swaging method.

Swaging machine is a molding machine that plastically deforms various metals according to the shape of a mold by compression or impact, and has less material loss than cutting, so that the strength of the material increases, and thus it is widely used for manufacturing tungsten.

In this way, the swaging method using the swaging machine is to forge by rotating the mold together with the main shaft and hitting the material, and it is mainly applied when the deformation angle between shafts is small in the longitudinal direction as the material flows in. The ram end of the swaging method Ram end forming is a process that presses the forming die linearly into or out of the workpiece. As the die or material does not rotate, it is possible to process asymmetrical or complicated cross-sections, and also to process inside and outside simultaneously in the processing of pipes. It has merit.

However, the conventional swaging method has a problem that can not increase the productivity of the product because the processing speed is very slow, about 2 ~ 4m per minute.

Therefore, the present invention for solving the above problems in the manufacture of the hollow wheel shaft to the gear mechanism of the rotational movement of the steering wheel annealing, short and bond the material cut to the appropriate length after rust removal while increasing the ductility A film is formed on the surface, and the cold forging process is performed by pressing the material several times according to the shape of the product to form stepped portions in a plurality of places, and the serration process, the polishing and the rolling process are performed on both ends of the material. By forming the gear part during the serration process and forming the bearing insert part in the middle part, it reduces the capital investment cost, improves the productivity of the product, reduces the cost and significantly reduces the noise in the work. It is an object of the present invention to provide a hollow wheel shaft manufacturing method that can be expected.

The present invention for achieving the above object,

In the manufacturing method of the hollow wheel shaft for transmitting the rotational movement of the steering wheel to the steering gear mechanism,

A cutting step of cutting the rod-shaped material introduced through the straightener into the required length;

An annealing, shot and bond treatment of the cut material to improve the ductility of the material and to form a film on the surface while removing the rust of the material;

A cold forging step of forming a second stepped portion and a third stepped portion to form a first double stepped portion on one side of the middle portion of the raw material by using a hydraulic press and gradually decreasing the diameter on one side thereof;

A serration process of processing a first serration inside the other side of the intermediate portion to form an insertion portion, and processing a second serration between the second step portion and the third step portion;                         

A polishing and rolling step of grinding the double stepped portion of the raw material to form a bearing inserting portion, and forming the gear portion by rolling on the outer circumferential surface of the third stepped portion; Characterized in that consisting of.

And, the cold forging process is characterized in that to form a first double-stepped portion by pressing with a hydraulic press in the state that the pin is not inserted into the material.

In addition, the cold forging process is characterized in that the second step portion is formed by performing a pressing step to reduce the inclination of the step portion after performing a pre-pressing process to increase the inclination of the step portion when processing the second step portion.

Surface polishing of the bearing insert in the polishing and rolling process is characterized in that the high-frequency pressure treatment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, FIGS. 1 and 2.

1 shows a hollow wheel shaft, in which a bearing inserting portion 9 is formed on one side (left side in the drawing) of the intermediate portion 1, the first double stepped portion 2a, 2b on the left side, The second step portion 3 and the third step portion 4 are formed, and the second serration 8 is formed between the second step portion 3 and the third step portion 4, and the third On the outside of the stepped portion 4, a gear portion 7 for engaging the gearbox is formed.

In addition, an insertion part 5 for connecting to a steering column is formed at the other side (right side in the drawing) of the intermediate part 1, and a first serration 6 is formed at an inner circumferential surface of the insertion part 5. Structure.

The manufacturing method of this invention is demonstrated for each process.

◆ Cutting Process ◆

The cutting process is a process of cutting the rod-shaped material introduced through a straightener into the required length, and the length of the material to be cut in this process is calculated by obtaining the volume of the finished product.

◆ Pretreatment Process ◆

It refers to the process of annealing, shorting and bonding the material cut to the required length.

Annealing (also known as annealing process) is to heat the material at a heating temperature of 800 ℃ or higher for more than 90 minutes, then gradually cools the material to refine the grains to increase the ductility, and the short process uses an annealing process using shot blasting or an acid treatment process. It is a process to remove the rust of material generated in

Then, after the short process, the bond process is performed again. This bond process is a process of lubricating the material to form a film to extend the life of the mold when pressing the material and to facilitate the molding of the product.

It is to remove the rust generated in the material in the annealing process while improving the ductility of the material through the pretreatment process as described above, and to form a film on the surface of the material.

◆ Cold Forging Process ◆

The cold forging process is to press the material several times to form the shape of the product.

First, the material prepared as shown in FIG. 2A is pressed by a hydraulic press to form double stepped portions 2a and 2b on one side of the intermediate portion 1 as shown in FIG. 2b.

At this time, the inside of the material is press-molded from the outside in the state of not inserting a separate pin for shape molding.

Thereafter, the second stepped portion 3 is formed on the left end of the raw material. First, pressing is performed while the pin is inserted into the raw material as shown in FIG. 2C ₁ so that the inclination angle of the second stepped portion 3a is increased. pressing and machining after the wire pressing the inclination angle of the second step (3b) as shown in Figure 2c is processed after ₂ also becomes smaller.

The post-pressing step may be performed immediately without the pre-pressing step in processing the second stepped portion 3.

After the second stepped part 3 is processed, pressing the third stepped part 4 on the outside thereof (see FIG. 2D ₁ ), and then reducing the outer shaft diameter of the third stepped part 4 as shown in FIG. 2D ₂ . Perform.

The portion in which the shaft diameter is reduced is the position at which the gear portion 7 is formed.

Through several pressing operations as described above, the outer shape of the wheel shaft is formed on the material.

◆ Serration Process ◆

As shown in FIG. 2E, the serration processing is performed by pressing the outside of the material in the state where the pin for serration processing is inserted into the other side (right side in the drawing) of the intermediate portion 1, thereby forming the first serration on the inner circumferential surface. The insertion part 5 in which 6) was formed is shape | molded.

Moreover, the 2nd serration 8 is processed in the part between the 2nd step part 3 and the 3rd step part 4 by a pressing operation.

◆ Polishing & Rolling Process ◆

The bearing inserting portion 9 is formed by pressing the double stepped portion 2b of the raw material, and the surface of the bearing inserting portion 9 is subjected to high frequency pressure reduction so that the bearing can be easily inserted.

Finally, a rolling operation is performed on the outer side of the third step portion 4 to form the gear portion 7.

According to the hollow wheel shaft manufacturing method of the present invention as described above, since the hollow wheel shaft is produced by the cold forging method, the product production time can be significantly shortened, and the product can be produced by cutting the material to the desired length. Therefore, the cost can be significantly reduced, and the equipment for producing the product can be made with a slight deformation from the hydraulic press, which is used in the past, so that the production equipment can be flexibly achieved.

As described above, in the present invention, in manufacturing a hollow wheel shaft in a gear mechanism, the rotational movement of the steering wheel is annealed, shorted, and bonded to a material cut to an appropriate length, thereby improving ductility and removing rust on the surface. Performs cold forging process that forms a film, and forms the stepped parts in multiple places by pressing the material several times according to the shape of the product, and performs serration on both ends of the material by performing the serration process and the polishing and rolling process. By forming the gear part during processing, and forming the bearing insert part in the middle part, it can reduce the capital investment cost, improve the productivity of the product, and reduce the cost and significantly reduce the noise in the work. The effect of providing a hollow wheel shaft manufacturing method can be expected.

Claims (4)

In the manufacturing method of the hollow wheel shaft for transmitting the rotational movement of the steering wheel to the steering gear mechanism, A cutting step of cutting the rod-shaped material introduced through the straightener into the required length; An annealing, shot and bond treatment of the cut material to improve the ductility of the material and to form a film on the surface while removing the rust of the material; The first stepped portion 2a, 2b is formed on one side of the middle portion 1 of the raw material using a hydraulic press, and then the second stepped portion 3 and the third stepped portion 4 are gradually reduced in diameter to one side thereof. Cold forging process for forming the mold; The first serration 6 is formed inside the other side of the intermediate portion 1 to form the insertion portion 5, and a second portion between the second step portion 3 and the third step portion 4. A serration step of processing the serration 8; A grinding and forging step of grinding the double stepped portion 2b of the raw material to form the bearing inserting portion 9, and forming the gear portion 7 by rolling on the outer circumferential surface of the third stepped portion 4; Hollow wheel shaft manufacturing method characterized in that consisting of. The method of claim 1, wherein the cold forging process is a hollow wheel shaft manufacturing, characterized in that to form a first double-stepped portion (2a, 2b) by pressing with a hydraulic press in the state that the pin is not inserted into the inside of the material Way. The method of claim 1, wherein the cold forging step is performed after the pre-pressing step of processing the stepped portion to increase the inclination of the stepped portion when the second stepped portion 4 is processed, and then the press step is carried out to reduce the inclination of the stepped portion to the second step. Hollow wheel shaft manufacturing method characterized in that the forming part (4). The method of claim 1, wherein the surface grinding of the bearing insert (9) in the polishing and rolling process is performed by a high-frequency low pressure treatment.

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