JPH03118980A - Plasma cutting or welding torch - Google Patents

Abstract

PURPOSE:To eliminate the need for a high-frequency circuit and to miniaturize a power source part by providing an electrode movable on an axis concentrically with a nozzle on the inside of the nozzle to guide plasma gas and providing an elastic body to energize the electrode and a starting switch to bring the electrode into contact with the nozzle against the elastic body. CONSTITUTION:At the time of starting plasma cutting or welding, the tip of the electrode 14 comes into contact with the inner bottom of the nozzle 12 and an electric current is carried to the electron radiation surface 14a of the electrode 14 via the nozzle 12 from material 18 to be cut by pushing downward the starting switch 16. At the time of starting a plasma arc of plasma cutting or welding, when the starting switch 16 is released, the electrode 14 is pushed up to the maximum distance position from the mutual contact position with the nozzle 12 by pressing force of a compression spring 15. At this time, the moment the electrode 14 separates from the nozzle 12 the arc is generated and the arc is blown by plasma gas and transferred to the arc between the electron radiation surface 14a of the electrode 14 and the material 18 to be cut which can be cut. In this way, arc starting is made possible without necessitating the high-frequency circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to plasma cutting or bath torches.

Conventional technology An example of a conventional plasma cutting machine is shown in FIG.

In FIG. 2, one terminal of the DC power supply 1 is connected to one end of the capacitor 2, and is also connected to the object to be cut 4 via the coupling 3, and the negative terminal is connected to the other end of the capacitor 2. It is connected to electrode 5. As shown by arrow A, this @ electrode 5 is arranged concentrically inside a nozzle 6 that guides the plasma gas, and is arranged with the electron emitting surface at the lower end of the electrode 5 facing the opening 6a of the nozzle 6. .

With the above configuration, the capacitor 2 is connected to the coupling coil 3
The high frequency generated in
Direct current arc discharge is induced while ejecting plasma gas through a.

Problems to be Solved by the Invention The conventional high-frequency activation system described above has the problem of not only causing radio wave interference to televisions, radios, etc., but also causing malfunctions of peripheral electronic equipment. Furthermore, since the plasma cutting machine requires a high frequency circuit, there are problems in that it increases the cost and makes it impossible to reduce the size and weight of the power supply section.

The present invention solves the above-mentioned conventional problems, and can prevent radio wave interference to television receivers, radio receivers, etc. and malfunction of peripheral electronic equipment, and furthermore, can reduce the size and weight of the power supply unit and reduce the cost. It is an object of the present invention to provide a plasma cutting or welding torch that can reduce costs.

Means for Solving Section U In order to solve the above problems, the plasma cutting or welding torch of the present invention is arranged concentrically inside a nozzle for guiding plasma gas, and is in mutual contact with the nozzle. an electrode capable of axial movement from a normal position to a maximum separation position; an elastic body that biases the electrode toward the maximum separation position; and an axial movement of the electrode against the bias of the elastic body; It is equipped with an activation switch that is brought into contact with the nozzle.

Effect: With the above configuration, when starting the plasma cutting machine,
First, when you press and move the startup switch of the plasma cutting or welding torch, the electrode that is at the maximum separation position from the nozzle during normal operation will be biased toward this maximum separation position. The electrode moves axially toward the nozzle against the bias of the elastic body, contacts the nozzle, and current flows between the workpiece and the electrode through the nozzle.Next, the start switch is turned on. When the pressure is released, the nozzle and the electrode begin to separate from each other due to the urging force on the elastic body toward the maximum separation position from the nozzle, and at this moment, a plasma arc is generated between the nozzle and the electrode. Further, the electrode makes an axial movement toward the maximum separation position from the nozzle, but at this time, the plasma arc is blown by the plasma gas ejected from the nozzle opening toward the workpiece, and the plasma between the electrode and the workpiece is blown away. The process shifts to an arc, the startup of the plasma cutting machine is completed, and the workpiece can be cut or welded.

In this way, unlike conventional methods, high frequencies are not used during startup, so there is no noise generation, and there is no radio wave interference to television receivers, radio receivers, etc., and there is no interference such as malfunction of surrounding electronic equipment. It also disappears. Furthermore, a high-frequency circuit (spark oscillation circuit, high-frequency transformer, coupling coil, high-frequency capacitor, etc.) is not required in the power supply section, and a plasma cutting or welding torch can be obtained in which the power supply section can be made smaller and lighter, and the cost can be reduced.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

1(aHb) and 1(c) are configuration diagrams of a plasma cutting machine including a plasma cutting or welding torch, which is an embodiment of the present invention, and FIG. 1(a) shows the standby state,
b) shows the state at startup, and FIG. 1(C) shows the state at plasma arc. In FIG. 1(a), the orifice 11
The lower end of the nozzle 12 has an opening 12a at its tip.
is fixed, and the upper end is fixed to a torch outer skin 13 made of a resin material. These orifices 11 and nozzles 12
An electrode 14 having an electron emitting surface 14a at the lower end and a collar portion 14b at the upper end is arranged concentrically with the orifice 11 and the nozzle 12 inside the electron 4I! 14 brim portion 14b
and the large-diameter stepped portion 11a of the orifice 11 in which the flange portion 14b is accommodated. A compression spring 15 is interposed to bias I. In addition, a small hole 1 is provided in the peripheral wall of the orifice 11.
1b is provided, and as shown by arrow B, the plasma gas is guided inside to swirl around the electrode 14, and the nozzle 1
It is configured to eject from the opening 12a of No. 2.

In addition, the torch outer shell 13 has electricity! A hole 13a is provided concentrically with f114, and a starting switch 16 is provided in this hole 13a.
is inserted so that its tip is in contact with the upper end surface of the electrode 14. Further, the positive end of the DC power source 17 is connected to the object 18 to be cut, and the negative end is connected to the electrode 14. Furthermore, the orifice 11 is an insulator and insulates the nozzle 12 and the electrode 14.

With the above configuration, when waiting for plasma cutting or welding, as shown in FIG. 1(a), the compression spring 15
is pushed upwards, and electric! f114 is at the maximum separation position from the nozzle 12.

Here, when starting plasma cutting or welding, the first t
g As shown in (b), by pressing the starting switch 16 downward, the tip of the electrode 14 comes into contact with the inner bottom surface of the nozzle 12, and the current flows from the object 18 to the nozzle 12.
The electrons flow to the electron emitting surface 14a of the electrode 14 via the electron beam.

Next, when starting the plasma arc for plasma cutting or welding, as shown in FIG.
2 will be pushed up to the maximum distance position. At this time, the electric fl! 14 is nozzle 12
An arc is generated at the moment of separation, and the arc is blown by the plasma gas and transfers to an arc between the electron emitting surface 14a of the electrode 14 and the object to be cut 18, making it possible to cut the object to be cut 18. It is what it is.

In this way, arc starting can be performed very easily without requiring high frequency at the time of starting.

Therefore, there is no need for high frequencies over a very wide band, from several KHz to several MHz, as in the past, so there is no noise, and there is no radio interference to television receivers, radio receivers, etc. While it has the effect of not causing any damage to electronic equipment, it also eliminates the need for high-frequency circuits (spark oscillation circuits, high-frequency transformers, coupling coils, high-frequency capacitors, etc.), which reduces the cost and size of the power supply section. Helpful.

Effects of the Invention As described above, according to the present invention, it is possible to prevent radio wave interference to television receivers, radio receivers, etc. without requiring the aid of high frequency waves at startup, and also to prevent radio wave interference to television receivers, radio receivers, etc.
High frequency transformer, spark gap, coupling coil,
This eliminates the need for high-frequency capacitors (such as high-frequency capacitors), making the power supply section smaller and lighter and contributing to significant cost reductions. Furthermore, unlike the method of fixing the electrode and sliding the nozzle, the method of the present invention turns on the starting switch,
It is very similar to the conventional high frequency activation method that turns off, and has superior operability.

[Brief explanation of drawings]

1(a), 1(b), and 1(c) are configuration diagrams of a plasma cutting machine including a torch for plasma cutting or welding according to an embodiment of the present invention, and FIG. FIG. 1(b) is a diagram showing the state when the plasma arc is started. FIG. 1(C) is a diagram showing the state during plasma cutting or welding. U
1 is a block diagram of a plasma cutting machine including a conventional plasma cutting or welding torch. 12... Nozzle, 14... Electrode, 15... Compression spring, 16... Starting switch, B... Plasma gas.

Claims (1)

[Claims] 1. An electrode arranged concentrically with the nozzle inside a nozzle that guides plasma gas and capable of axial movement from a position of mutual contact with the nozzle to a maximum separation position in a steady state; A torch for plasma cutting or welding, comprising: an elastic body that biases the electrode; and an activation switch that moves the electrode in an axial direction against the bias of the elastic body and brings it into contact with the nozzle.