JPH06218551A - NC plasma cutting method - Google Patents

Abstract

(57) [Summary] [Objective] To provide an NC plasma cutting method capable of extending the life of a plasma torch. [Composition] An NC plasma cutting machine 3 having an air generating source 1 and an oxygen generating source 2, a plasma power source 5 and a plasma torch 4 arranged in a factory, and a relay section 6 is arranged in the NC plasma cutting machine 3. Then, a switching valve 7 is arranged in the relay portion 6, an air tube 9 connected to the air generation source 1 and an oxygen tube 10 connected to the oxygen generation source 2 are connected to the upstream side of the switching valve 7, and the downstream side is connected to the downstream side. The plasma tube 11 connected to the plasma torch 4 is connected to the side,
An NC plasma cutting method in which the oxygen tube 10 and the plasma tube 11 are connected to cut an object to be cut at the time of cutting a welding butt portion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an NC plasma cutting method, and more particularly to an NC plasma cutting method used for cutting a metal material such as a steel plate at a high speed.

[0002]

2. Description of the Related Art Generally, N for cutting a metal material such as a steel plate
The C plasma cutting method is adopted. In this NC plasma cutting, a plasma current is supplied to a plasma torch from a plasma power source mounted on a cutting machine, and at the same time, a gas such as oxygen is supplied to cut a metal material. A mixed gas of argon and hydrogen or nitrogen is used.

This air plasma and oxygen plasma have advantages and disadvantages. That is, the former has advantages such as being suitable for cutting metal materials such as steel, stainless steel, and aluminum and having a relatively long life of electrodes, but since the bevel angle is relatively large and the cut surface is nitrided, welding is performed. Blow holes sometimes occur, which is a problem as a cutting method. For this reason, oxygen plasma has been generally used in recent years.

[0004]

By the way, in the above-mentioned oxygen plasma cutting, the plasma torch electrode,
The life of the nozzle is very short, about 1.5H, which is not only costly but also requires frequent replacement of the plasma torch electrode and nozzle, resulting in poor cutting efficiency. It was

From the above, it is conceivable that during welding, specifically, when cutting a portion where a predetermined butt welding is performed, cutting is performed using oxygen plasma, and other cutting is performed using air plasma. However, in this case, two cutting machines are required, and there is a problem that the equipment cost increases accordingly.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and includes an air source, an oxygen source, a plasma power source and a plasma torch arranged in a factory. An NC plasma cutting machine having the relay unit arranged in the NC plasma cutting machine, a switching valve arranged in the relay unit, and an air tube connected to the air generating source and the oxygen generation upstream of the switching valve. The oxygen tube connected to the source is connected, and the plasma tube connected to the plasma torch is connected on the downstream side, so that the oxygen tube and the plasma tube are connected at the time of cutting the welding butt portion to cut the object to be cut. NC
A plasma cutting method is provided. It should be noted that the air tube and the plasma tube are connected to efficiently cut the portion other than when the welding butt portion is cut.

[0007]

[Operation] According to the NC plasma cutting method, the oxygen plasma cutting necessary for cutting the welding butt portion by one NC cutting machine is performed, and the plasma torch electrode and the nozzle with a long life are used for other cutting. Plasma cutting can be performed.

[0008]

EXAMPLE An example of the NC plasma cutting method according to the present invention will be described below with reference to FIGS. 1 and 2. In FIG. 1, 1 is a compressor as an air generation source,
Reference numeral 2 is an oxygen production apparatus as an oxygen generation source, and the compressor 1 and the oxygen production apparatus 2 are arranged at predetermined positions in the factory.

Reference numeral 3 is an NC plasma cutting machine.
The C plasma cutting machine 3 includes a plasma torch 4, a separately installed plasma power source 5, and a relay section 6 (relay box). The relay section 6 includes at least a switching valve 7 and a switching switch 8. Are arranged. An air tube 9 connected to the compressor 1 and an oxygen tube 10 connected to the oxygen production apparatus 2 are connected to the upstream side of the switching valve 7, and a plasma connected to the plasma torch 4 is connected to the downstream side of the switching valve 7. The tube 11 is adapted to be connected.

The plasma power source 5 and the plasma torch 4 are
A wire 12 is connected via a changeover switch 8 on the way. Reference numeral 13 is a dryer for drying air, 14 is an operation button for operating the changeover switch 8, and 15 is an operation button for operating the changeover valve. With such a configuration, when a metal material such as a steel plate is cut by an NC plasma cutting machine, and when the cut portion is to be butt-welded with another processed member in a subsequent process, the switching valve 7 is operated. Oxygen tube 1
After connecting 0 and the plasma tube 11, while supplying oxygen from the oxygen production apparatus 2 to the plasma torch 4,
The changeover switch 8 is connected to supply a current from the plasma power source 5 to the plasma torch 4 to cut the object to be cut.

At this time, the cut surface is oxidized, but is not nitrided. Therefore, when butt welding is performed, there is no possibility of generating blowholes. On the other hand, when the cut portion is to be T-welded in a later process or simply to be finished by painting, the switching valve 7 is operated to connect the air tube 9 and the plasma tube 11 to connect the compressor 1 to the plasma torch. 4 is supplied with air and a current is passed from the plasma power source 5 to the plasma torch 4 to cut the metal material.

In this case, the cut surface is nitrided, but since there is no welding at such a portion, there is no problem in the next processing. According to the knowledge of the present inventors, when cutting a steel plate when building a ship, the cut portion of the butt weld is about 10%.
And the life of the plasma torch 4 is about 1.5H in oxygen plasma, while that of air plasma is about 4.
It becomes 0H, and the air plasma is approx.
2.5 times longer. Therefore, by combining the advantages of air plasma and oxygen plasma, there is an effect that replacement time can be saved together with cost reduction.

FIG. 2 shows another embodiment, in which, in addition to the air tube 9 and the oxygen tube 10, a hydrogen tube 16, a nitrogen tube 17 and an argon gas are provided upstream of the switching valve 7 mounted on the NC plasma cutting machine 3. Tube 18 is connected,
The hydrogen tube 16, the nitrogen tube 17, and the argon tube 18 are connected to a hydrogen cylinder, a nitrogen cylinder, and an argon cylinder, respectively, which are arranged in the collecting device 19.

Particularly, in the case of aluminum or stainless steel and a relatively thick plate, the switching valve 7 is operated to operate the argon tube 18 and the hydrogen tube 16, or the argon tube 1.
8 and the nitrogen tube 17 and the plasma tube 11 are connected to each other to supply the plasma torch 4 with argon and hydrogen or a mixed gas of argon and nitrogen. Of course, when such a mixed gas is used, it is necessary to replace the plasma torch 4 with a structure suitable for this in advance.

[0015]

According to the NC plasma cutting method of the present invention,
An NC plasma cutting machine having an air generating source and an oxygen generating source, a plasma power source and a plasma torch arranged in a factory, a relay section is arranged in the NC plasma cutting machine, and a switching valve is arranged in the relay section. , Connecting an air tube connected to the air generation source and an oxygen tube connected to the oxygen generation source on the upstream side of the switching valve, and connecting a plasma tube connected to the plasma torch on the downstream side at the time of cutting the welding butt portion. The object to be cut is cut by connecting the oxygen tube and the plasma tube.

Therefore, by operating the switching valve arranged in the relay section, different gas can be supplied to the plasma torch by one NC plasma cutting machine to cut the metal material appropriately. As a result, the cutting cost and the cutting work can be shortened.

[Brief description of drawings]

FIG. 1 is an overall system diagram in an example of an NC plasma cutting method according to the present invention.

FIG. 2 is an overall system diagram in another embodiment.

[Explanation of symbols]

1 Compressor 2 Oxygen Production Device 3 NC Plasma Cutting Machine 4 Plasma Torch 5 Plasma Power Supply 6 Relay Section [Relay Box] 7 Changeover Valve 8 Changeover Switch 9 Air Tube 10 Oxygen Tube 11 Plasma Tube 12 Wiring 13 Dryer 14, 15 Operation Button 16 Hydrogen tube 17 Nitrogen tube 18 Argon tube 19 Collecting device

Claims (1)

[Claims] 1. An N having an air source, an oxygen source, a plasma power source, and a plasma torch arranged in a factory.
A C plasma cutting machine, a relay section is arranged in the NC plasma cutting machine, a switching valve is arranged in the relay section, and an air tube connected to the air generation source and the oxygen generation source are provided upstream of the switching valve. NC connected to a plasma tube connected to the plasma torch on the downstream side, and connecting the oxygen tube and the plasma tube at the time of cutting the weld abutting part to cut the object to be cut. Plasma cutting method.