Ohmic heating method and ohmic heating device

Abstract

The invention relates to an ohmic heating method and an ohmic heating device. Through the ohmic heating method and the ohmic heating device, the quenching or annealing of the back surface and tooth surface of a workpiece can be carried out in a roughly continuous operation period, and the high-precise quenching or annealing quality is easily obtained on the back surface or tooth surface while striving to improve the efficiencies of quenching or annealing. The ohmic heating method is characterized by comprising the following steps that a switching device is switched to a back surface side, so that one pair of first touch points contact the two ends of the heating range in the length direction of the back surface of the workpiece supported by a support device, the regulated frequency and output current for the back surface are supplied to the touch points from a power supply device, and then ohmic heating is carried out on the back surface; and after the step, the switching device is switched to a tooth surface side, so that one pair of second touch points contact the two ends of the heating range in the length direction of the tooth surface of the workpiece, the regulated frequency and output current for the tooth surface are supplied to the touch points from the power supply device, and then the ohmic heating is carried out on the tooth surface.

Description

technical field [0001] The present invention relates to an electric heating method and an electric heating device used for quenching or tempering the back surface and tooth surface of workpieces such as steering racks by electric heating. Background technique [0002] Originally, such an electric heating device is disclosed in, for example, Patent Document 1 (eg, Japanese Patent No. 4232973). This energized heating device is equipped with a pair of energized electrodes (contacts) arranged opposite to each other within the heating range along the length direction of the rack, a power supply device that supplies a current of a specified frequency to the energized electrodes, and an intermediate position from the opposing direction of the energized electrodes. A terminal portion extending in a horizontal direction substantially linearly intersecting the facing direction starts, and a predetermined current is supplied from the energizing electrode of the power supply unit throug...

AI Technical Summary

Problems solved by technology

[0003] However, this energized heating device makes a pair of contacts contact the tooth surface or the back of the rack, and then supplies the specified output current to the tooth surface or the back respectively, so as to achieve the purpose of heating the tooth surface or the back of the rack for quenching. However, after the back of the rack is quenched, it cannot continue to quench the tooth surface

Therefore, the quenching or tempering of the back of the rack and the tooth surface cannot be performed in a substantially continuous operation cycle, and there are problems such as low working efficiency and difficulty in guaranteeing the quality of quenching or annealing of the back of the rack or the tooth surface.

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