Thermal hydro-mechanical drawing forming method for dot matrix self-impedance electrical heating plates

Abstract

The invention relates to a thermal hydro-mechanical drawing forming method for dot matrix self-impedance electrical heating plates, and belongs to the technical field of the thermal hydraulic forming of the plates. The method comprises the following steps of: fully filling liquid into a cavity of a female die serving as a liquid pond; when the plates are driven by a male die to enter the female die, forming the plates by reverse pressure generated when the liquid is compressed; embedding pin type electrodes inside pressure plates according to the distribution of dot matrixes, and performing self-impedance electrical heating on flanges of the plates by using contact resistors between the electrodes and the plates; adjusting the distribution of temperature fields of the flanges by changing the distribution law of the dot matrixes of the electrodes and adjusting the heating current of each heating electrode; adjusting the flow stress of heating points by changing the temperature of each mass point on the flanges so as to control the flow of metal by the asynchronous flow of the metal mass points on the flanges; and coordinating the deformation process of the metal by the asynchronousdeformation of each mass point on the flanges due to the temperature to fulfill the aim of improving the limit drawing ratio of the plates. The method has the advantages that: the heating speed is high, the effect is good, the plates can be heated controllably and flexibly, and the forming limit of the plates is improved.

Description

Technical field: [0001] The lattice self-resistance electric heating sheet metal warm and liquid-filled deep drawing forming method of the present invention belongs to the technical field of sheet metal warm forming. Background technique: [0002] Sheet metal hydraulic warm forming is one of the development trends of sheet metal hydraulics. By heating the sheet blank at the flange part, the drawing resistance can be reduced and the ultimate drawing ratio of the sheet can be improved. It is usually used to embed heating resistors inside the pressing plate and the cavity to heat the flange part, such as figure 2 Shown. The flange is heated by the heating method of embedded resistance, the heating flexibility is low, the controllability is poor, and the formed temperature field is relatively uniform, which is not conducive to the differential control of metal flow. In sheet metal forming, coordinate and control the metal flow of each particle in the deformation zone, and use the a...

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Problems solved by technology

The flange is heated by the heating method of buried resistance, which has low heating flexibility and poor controllability, and the formed temperature field is relatively uniform, which is not conducive to the differential control of metal flow

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