Method for bending metal material, bending machine, bending-equipment line, and bent product

Abstract

A method, bending machine, and bending equipment line for bending a workpiece involves successively or continuously feeding the workpiece held by a supporting unit from an upstream side of the supporting unit, and performing bending at a downstream side of the supporting unit. The bending method includes: supporting the metal material with a movable roller die; controlling the position of the movable roller die and / or the moving speed of the metal material; heating the metal material in a temperature range in which the heated portion can be plastically deformed and in a temperature range in which quenching can be performed, by using a heating unit that is provided around the outer circumference of the metal material, to apply a bending moment to the heated portion; and rapidly cooling the heated portion, by using a cooling unit that is provided around the outer circumference of the metal material.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for bending a metal material, a bending machine, and a bending-equipment line, and more particularly, to a method for effectively bending a metal material through a two-dimensional continuous bending operation in which the metal material is two-dimensionally bent in different directions (for example ending in a S shape) or a three-dimensional continuous bending operation in which the metal material is three-dimensionally bent in different directions, to a bending machine and a bending-equipment line to which the bending method can be applied, and to a bent product made by the bending machine or the bending-equipment line. BACKGROUND ART [0002] In recent years, demands for structural metal materials having high strength and light weight have increased in consideration of global environment. For example, in an automobile industry, there are growing demands for a safe car body and high-strength and light-weight parts of a...

AI Technical Summary

Benefits of technology

[0011] As described above, a technique for bending a metal material in various bending shapes to be applied to various parts of an automobile is demanded with reexamining the structures of the parts of an automobile. Meanwhile, it is desirable that the metal material have a tensile strength of 900 MPa or more, preferably, 1300 MPa or more, in order to reduce the weight of the metal material. In this case, a metal tube having a tensile strength of about 500 to 700 MPa is bent as a starting material and a thermal treatment is performed on the bent metal tube to improve the strength of the metal tube, thereby obtaining a metal material having high strength.

Problems solved by technology

However, in the grab bending method disclosed in Japanese Patent Application Publication No. 50-59263 and Japanese Patent No. 2816000, since the feeding speed of the metal tube varies significantly, the cooling speed cannot be accurately controlled, and a high degree of quenching accuracy cannot be ensured, which makes it difficult to prevent the occurrence of non-uniform distortion.

Thus, products made by the grab bending method are not suitable for parts of an automobile.

Further, the bending machine disclosed in Japanese Patent No. 3195083 is based on push-through bending, but does not disclose a technique for performing hot working on a metal tube having low strength as a starting material and then performing quenching on the heated metal tube to increase the strength of the metal tube so as to obtain a metal material having high strength.

In addition, the metal material is likely to have seizure defects on the surface of the movable gyro die due to heating.

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