CN103357805A - Method for forging formation of pin track - Google Patents

Abstract

The invention discloses a forging forming method of a pin rail, the steps of which are: heating, billet making, pre-forging, final forging, edge trimming, and thermal correction; the feature is that the pre-forging die and the final forging die are an integral die , The production efficiency is improved, and the wall thickness of the mold is more than doubled, which effectively avoids the cracking of the mold and improves the service life of the mold. At the same time, this method also uses a trimming die, including a trimming punch and a trimming die. The effective containment area of the trimming punch and the pin rail forging is the top and side surfaces of the forging tooth shape, the top and side surfaces of the wide and narrow ribs, The containment area is large, and it is not easy to produce defects such as warping, slumping, and bell mouth.

Description

Forging forming method of pin rail

technical field

The invention belongs to the field of forging forming, and relates to a forging forming method of a pin rail.

Background technique

At present, domestic pin rails have begun to develop from the previous methods of split welding and integral casting to integral forging. The molds for integral forging are basically designed with a single mold, and the wall thickness of this mold is thin and prone to cracking. A set of molds will be scrapped after producing about 1800 forgings, which seriously wastes funds and affects the production progress of products. Moreover, when cutting the edge, the current two-step cutting method is adopted. First, the tooth-shaped middle skin is cut, and then the rough edge of the outer peripheral parting surface is cut. At the same time, the height of the wide and narrow ribs is not enough to accommodate the two ends; in the second step, the punch will first contact the top surface of the raised wide and narrow ribs, causing the two ends to be upset and collapsed. , In the process of cutting the outer circumference and connecting the skin, the effective accommodation in the height direction of the pin rail is not enough, resulting in the middle warping, which increases the scrap rate.

Contents of the invention

In order to overcome the above disadvantages, the present invention provides a forging forming method of a pin rail, which improves the service life of the mold and improves production efficiency. At the same time, defects such as warpage, slump, and bell mouth of pin rail forgings are eliminated.

In order to solve the above problems, the technical solution of the present invention is: a forging forming method of a pin rail, the steps of which are:

First, put the billet into a medium-frequency induction heating furnace and heat it to 1240~1290°C, and make the billet into a shape basically similar to the pre-forging cavity by means of roll forging, die forging, and flattening.

Secondly, the pre-forging die and the final forging die are designed as an integral die, the distance between the pre-forging cavity and the final forging cavity is 190mm~220mm, and the distance between the pre-forging cavity or the final forging cavity and the outer wall of the mold should be Greater than 150mm. First put a piece of pin rail blank into the pre-forging cavity of the overall mold for pre-forging, then put the pre-forged pin rail blank into the final forging cavity of the overall mold, and then take a piece without pre-forging The forged pin-rail blank is put into the pre-forging cavity of the overall mold, and the final forging of the previous pin-rail and the pre-forging of the next pin-rail are completed at the same time, and the forging is carried out in sequence.

Secondly, design a trimming die, including a trimming punch and a trimming die, and the effective containment surface of the trimming punch for the pin-rail forging includes the top and side surfaces of the tooth profile of the pin-rail forging, and the top and side surfaces of the wide and narrow ribs. And use the trimming die to trim the pin rail forgings.

Finally, the pin rails are corrected.

Beneficial effects of the present invention: the upper die of the final forging die and the upper die of the pre-forging die are made into a whole, the lower die of the final forging die and the lower die of the pre-forging die are made into a whole, and its wall thickness is more than twice the original, effectively It avoids the occurrence of mold cracking, improves the service life of the mold, and because the pre-forging and final forging are carried out at the same time, the production efficiency is greatly improved. In the process of edge trimming, the tooth-shaped intermediate skin and the burrs of the outer peripheral parting surface are simultaneously cut on the same edge trimming die, and the effective containment area of the edge trimming punch for the pin rail forging is changed from the local area of the top surface of the previous wide and narrow ribs. The contact is changed to full contact between the punch and the top and side surfaces of the tooth shape of the forging, and the top and side surfaces of the wide and narrow ribs, which increases the effective containment area by nearly 4 times, and effectively solves defects such as warping, slump, and bell mouth.

Description of drawings

The specific embodiment of the present invention is described in further detail below in conjunction with accompanying drawing, wherein:

Fig. 1 is the mold cavity structure schematic diagram of integral mould;

Figure 2a is a cross-sectional state diagram when the edge trimming punch is trimming;

Fig. 2b is a cross-sectional view of A-A in Fig. 2a;

Fig. 3 is a three-dimensional structure diagram of a pin rail forging.

Detailed ways

To implement the pin rail forging molding method described in the present invention, the equipment that needs to be used includes: medium frequency induction heating furnace, Ф930 roll forging machine, KP8000 forging press, 800T trimming machine, and 1250T correction machine. The molds that need to be used are: integral mold and trimming mold.

The forging process steps of the pin rail are as follows:

The first step, heating. Put the blank into a medium frequency induction heating furnace and heat it to 1240~1290°C.

The second step is blank making. Use Ф930 roll forging machine and KP8000 forging press to make the heated billet into a shape basically similar to the pre-forging cavity by means of roll forging, die forging, and flattening. The initial forging temperature is ≥1220°C.

The third step is pre-forging and final forging. As shown in Figure 1, the pre-forging die and the final forging die are designed as an integral die, the distance between the pre-forging cavity 2 and the final forging cavity 3 is 190mm~220mm, and the pre-forging cavity 2 or the final forging cavity 3 The distance from the outer wall of the mold should be greater than 150mm.

First put a pin rail blank into the pre-forging cavity of the overall mold for pre-forging, then put the pre-forged pin rail blank into the final forging cavity of the overall mold, and then take a piece without pre-forging The finished pin rail blank is put into the pre-forging cavity of the overall mold, and the final forging of the previous pin rail and the pre-forging of the subsequent pin rail are completed at the same time, and the forging is carried out in sequence. Final forging temperature ≥ 1050°C.

The fourth step is to cut the edges eagerly. As shown in Figure 2a and Figure 2b, design a trimming die, including trimming punch 4 and trimming die 5, and use the trimming die to install on the 800T trimming machine, put the pin rail forging 6 into the trimming concave On the mold, and trimming; trimming temperature ≥ 950 ℃. During the trimming process, the effective containment area of the punch and the forging includes: the top and side surfaces of the tooth shape, and the top and side surfaces of the wide and narrow ribs.

The fifth step is thermal correction. Calibrate on a 1250T calibration machine. Calibration temperature ≥ 800 ℃.

The warping degree of the pin rail forging 6 forged by the above method is ≤3 mm, and there is no phenomenon of slump and bell mouth; 5498 forgings are produced using the integral mold without cracks.

Claims (3)

1. A forging forming method of pin rail, is characterized in that, comprises the following steps: First, put the billet into a medium-frequency induction heating furnace and heat it to 1240~1290°C, and make the billet into a shape basically similar to the pre-forging cavity by means of roll forging, die forging, and flattening. Secondly, the pre-forging die and the final forging die are designed as an integral die, the distance between the pre-forging cavity and the final forging cavity is 190mm~220mm, and the distance between the pre-forging cavity or the final forging cavity and the outer wall of the mold should be Greater than 150mm. First put a piece of pin rail blank into the pre-forging cavity of the overall mold for pre-forging, then put the pre-forged pin rail blank into the final forging cavity of the overall mold, and then take a piece without pre-forging The forged pin-rail blank is put into the pre-forging cavity of the overall mold, and the final forging of the previous pin-rail and the pre-forging of the next pin-rail are completed at the same time, and the forging is carried out in sequence. Secondly, design a trimming die, including a trimming punch and a trimming die, and the effective containment surface of the trimming punch for the pin-rail forging includes the top and side surfaces of the tooth profile of the pin-rail forging, and the top and side surfaces of the wide and narrow ribs. And use the trimming die to trim the pin rail forgings. Finally, the pin rails are corrected. 2. The forging forming method of the pin rail according to claim 1, characterized in that: the mold used for the pre-forging and final forging is designed as an integral mold. 3. The forging forming method of the pin rail according to claim 1, characterized in that: the trimming punch used for hot trimming, its effective containing surface includes the forging tooth-shaped surface, the top surface and the side surface of the wide and narrow ribs.

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