Press machine and pressing method

Abstract

A press machine includes a lower die having a step portion for forming a bent portion on a side surface, a pad portion supported by a spring and disposed adjacent to the lower die in the horizontal direction, being movable upward and downward, an upper die disposed opposing the pad portion in the vertical direction, and a regulation portion. When the upper die moves downward and presses a steel plate between the upper die and the pad portion to form a bent portion in an edge portion of the steel plate, the regulation portion moves together with the upper die and regulates the motion of the edge portion of the steel plate protruding from the lower die in the horizontal direction, thereby preventing a wrinkle from forming in the edge portion of the steel plate.

Description

CROSS-REFERENCE OF THE INVENTION[0001]This application claims priority from Japanese Patent Application No. 2014-016719, filed on Jan. 31, 2014, the content of which is incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The invention relates to a press machine and a pressing method for forming a bent portion in an edge portion of a steel plate.[0004]2. Description of the Related Art[0005]For vehicle components, a thinned and high-strength member is used so as to enhance both the safety and economy. For this purpose, so-called hot press is known in which a steel plate heated to high temperature is quenched by cooling the plate with low-temperature press dies. In this method, a steel plate is heated to an austenitizing temperature or higher, and the steel plate is formed and rapidly cooled with a press machine simultaneously, completing quenching.[0006]A certain kind of vehicle component has a bent portion (step portion) wi...

AI Technical Summary

Benefits of technology

[0009]According to the examination by the inventor, as shown in FIG. 6, it was found that when a step height 101 of a bent portion of a steel plate 100 is large and the edge portion of the steel plate 100 is curved, a wrinkle 103 occurs in the curved portion 102 and the steel plate 100 is significantly folded, and these problems significantly occur by the hot press of pressing the heated and soften steel plate 100 although it may also occur by the cold press. This invention is directed to this problem.

[0010]A press machine includes a lower die having a step portion on its side surface, a pad portion supported by a spring and disposed adjacent to the lower die in a horizontal direction, an upper die disposed opposing the pad portion in the vertical direction, and a regulation portion movable together with the upper die upward and downward in the vertical direction. The pad portion is movable upward and downward in the vertical direction. The upper die and the pad portion are configured to hold a steel plate between them, the lower die is configured to form a bent portion at an edge portion of the steel plate held between the upper die and the pad portion, when the upper die and the regulation portion move downward, and the regulation portion is configured to regulate a movement of the edge portion of the st

Problems solved by technology

However, when the upper die is moved downward to draw the steel plate toward the step portion of the lower die, a wrinkle occurs in the end portion

Images