Hot-pressing apparatus

Abstract

Disclosed is a hot-pressing apparatus capable of quenching a workpiece at a sufficient cooling rate. The hot-pressing apparatus performs a hot-press forming of a workpiece using a lower die and an upper die, in which a cooling channel and a cooling channel, and a plurality of gas-introduction paths and a plurality of gas-introduction paths through which heat-conducting gas flows are provided in the lower die and the upper die. The plurality of gas-introduction paths penetrate through the dies. The hot-press forming is performed while the heat-conducting gas is supplied to the areas between the dies and the workpiece from the plurality of gas-introduction paths opening on the forming surfaces of the dies.

Description

TECHNICAL FIELD[0001]The present invention relates to a hot-pressing apparatus which presses and cools a heated workpiece at the same time.BACKGROUND ART[0002]Conventionally, a hot-pressing apparatus is widely known which causes a die to press a workpiece, such as a steel plate, heated to above a temperature at which an austenite structure appears, and at the same time, quenches the workpiece by bring the die into contact with the workpiece.[0003]A technique on the hot-pressing apparatus is publicly known which enables the die to suitably cool the workpiece during the quenching by providing water channels through which cooling water to cool the die flows in the die (for example, see Patent Literature 1).[0004]However, since the pressed workpiece deforms because of spring back, uneven thickness thereof and the like, a gap is formed between the workpiece and the die during the quenching. Consequently, a contact area between the surface of the workpiece and the forming surface of the d...

AI Technical Summary

Benefits of technology

[0010]The present invention makes it possible to quench a workpiece at a sufficient cooling rate, and to prevent hardness of some parts in the workpiece from being smaller than a predetermined value.

Problems solved by technology

However, since the pressed workpiece deforms because of spring back, uneven thickness thereof and the like, a gap is formed between the workpiece and the die during the quenching.

Consequently, a contact area between the surface of the workpiece and the forming surface of the die decreases during the quenching, which causes a problem that some parts in the workpiece are not cooled at a sufficient cooling rate (e.g. 30 [° C. / sec] and above), and hardness of some parts in the workpiece is smaller than a predetermined value.

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