Arcing circuit for plasma arc cutting

Abstract

The invention discloses an arcing circuit for plasma arc cutting. The arcing circuit comprises a cutting torch, a direct-current power source, a pulse current circuit, a high-frequency high-voltage ignition circuit, an arc striking relay and an arc striking circuit, the arc striking relay and the arc striking circuit are serially connected between an anode of the direct-current power source and a nozzle of the cutting torch sequentially, a cathode of the direct-current power source is connected with an electrode of the cutting torch, the anode of the direct-current power source is further used for being connected with a workpiece, the arc striking circuit comprises an energy storing and releasing element, a unilateral connecting element, an energy discharging resistor and a switch, one end of the unilateral connecting element is connected with a normally-open end of the arc striking relay through the energy storing and releasing element while the other end of the same is connected with the nozzle of the cutting torch, and the energy discharging element and the switch are serially connected to be parallelly connected with the energy storing and releasing element. The arc striking circuit is adopted to replace a conventional arc striking resistor, a high-power arc striking resistor used in a conventional non-contact arc striking mode is abandoned, and capacitive components nearly free of loss are adopted, so that power loss in the process of arc striking is reduced and working safety of the components is improved.

Description

technical field [0001] The invention belongs to the technical field of plasma arc cutting, and more specifically relates to an arc starting circuit for plasma arc cutting. Background technique [0002] Plasma arc cutting is a cutting method that relies on a high-temperature and high-speed plasma arc beam to melt and evaporate part of the metal of the workpiece, blow it away from the substrate, and form a cutting kerf with the movement of the plasma arc cutting torch. At present, there are two methods for plasma cutting equipment to generate arcs. One is contact arcing. When starting the arc, the nozzle must be short-circuited with the workpiece. This method is difficult to start the arc on the workpiece with stains and rust. The surface is covered with insulation The metal plate of the protective film is almost impossible to cut, and the nozzle is easily damaged. [0003] Another method that is more commonly used today is non-contact arc ignition, which does not require con...

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Problems solved by technology

[0009] Aiming at the defects of the prior art, the purpose of the present invention is to provide an arc starting circuit for plasma arc cutting, which aims to solve the problems in the prior art that the arc starting resistance is easily damaged, the success rate of arc starting is low, and the nozzle is easy to be damaged.

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