JPS5839015B2 - Hot forging method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot forging method for forging a workpiece while reheating the forging produced during forging.

In the conventional hot forging method in which the workpiece is forged in a heated state, the paris that is generated around the workpiece during forging is generally thinner than the thickness of the workpiece, so the temperature decreases faster than the formed part.

For this reason, as the machining process progresses, machining of the crisp portion becomes difficult, and the machining load during final forming increases rapidly.

Therefore, in the past, the workpiece was heated to a higher temperature and then subjected to forging, taking into account the temperature drop in the paring part.

However, heating the workpiece to high temperatures reduces the machining load in the finishing process, but at the same time causes scale and decarburization on the molded product, and the mold is also exposed to high temperatures, which causes the mold to wear out quickly and shorten its lifespan. There were drawbacks such as a noticeable drop in performance.

This invention was made with the purpose of improving such drawbacks, and provides a hot forging method in which a workpiece is forged while reheating the forging produced during forging, thereby reducing the quality of the molded product and the wear and tear of the mold. The aim is to reduce the pressurizing load in the finishing process while also preventing this.

An embodiment of the present invention will be described in detail below with reference to the drawings.

In the figure, 1 is a bolster of a forging press (not shown), 2 is a slide provided above the bolster 1 so as to be movable up and down, and a plurality of lower molds 3 are provided on the upper surface of the bolster 1 and the lower surface of the slide 2 for each process. and an upper mold 4 are attached.

These upper and lower molds 4°3 are, for example, upper and lower molds 4°, 4 for preforming.
2 and 3□.

3□, idle lower mold 33 for Paris heating, and upper and lower molds 4 for finishing molding. , 34 and upper and lower trimming molds 4.3. Therefore, a Paris heating device 5 such as a high frequency coil is embedded in the idle lower mold 33 for Paris heating so as to surround the cavity 3a.

Approximately 900℃ (conventionally 10℃) using a heating furnace (not shown)
The workpiece 6 heated to 00°C or higher is preformed in the upper and lower preforming molds 41, 42 and 31, 3□ in the first and second steps, and then reaches the idle lower mold 33 for Paris heating, where it is heated to B'J6a generated during preforming by Paris heating device 5
is reheated to approximately the same temperature as the workpiece 6.

The workpiece 6 with the reheated part 6a is finished by the next upper and lower finishing molds 44.34, and then processed by the upper and lower trimming molds 4.34. .

35, the paris 6a is removed from the workpiece 6, and a molded product can be obtained.

As described in detail above, this invention provides a pari heating process in the middle of the forging process, and after heating the paris generated during forging in this paris heating process, the process proceeds to the finishing process. There is no need to heat the workpiece to a high temperature in consideration of the temperature drop.

As a result, it is possible to prevent scale and decarburization from occurring in the molded product obtained, and the reduction in the heating temperature of the workpiece reduces wear and tear on the mold, thereby extending the life of the mold itself.

Also, since Paris maintains the same temperature as the workpiece,
The machining load in the finishing process can be reduced, and machining accuracy is further improved.

[Brief explanation of the drawing]

The drawing is an explanatory view showing one embodiment of a forging die used in the method of this invention. 5 is a Paris heating device, 6 is a workpiece, and 6a is a Paris.

Claims (1)

[Claims] 1. In a device in which a heated workpiece 6 is sequentially forged between a plurality of molds provided for each process, a heating device 5 is provided to heat the bar IJ 6a generated during forging in the middle of the processing process, and this heating A hot forging method characterized by forging the workpiece 6 while reheating the paris 6a part using the device 5.