JPH08294778A - Method for starting plasma arc cutting and plasma arc cutting device - Google Patents

Abstract

PURPOSE: To eliminate influence on cutting of a discharged substance that is produced accompanying the formation of a hole, discharged on the surface of a material to be cutt, solidified and accumulated. CONSTITUTION: After a main arc is formed between an electrode and a material 1 to be cut so as to form a hole on the material 1, the circumference of the hole is cut including a part or all of the substance discharged accompanying the formation of the hole, and successively cutting is started for an objective cutting line. The device is provided with a transfer device 14 consisting of a body 12 for moving a torch 3 along the orthogonally crossing two directions and a carriage 13, and with a controller which controls the operation of the transfer device so that the torch 3 may be moved to a prescribed position in starting cutting, which, after forming a hole by controlling the operation of the torch when it reaches a prescribed position, cuts the circumference of the hole including a part or all of the discharged substance 4, and which controls the operation of the transfer device 14 so that cutting may be started for the objective cutting line successively to the cutting of the circumference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting starting method for starting cutting by eliminating the influence of an exhaust discharged along with the formation of a hole in a material to be cut, and a plasma cutting apparatus for carrying out this method. It is a thing.

[0002]

2. Description of the Related Art When a product is cut from a material to be cut such as a steel plate or a stainless steel plate by using a plasma cutting torch, the plasma cutting torch is opposed to a drilling position set in advance for a scrap portion of the material to be cut. Generally, a main arc is formed at the position to form a hole penetrating the material to be cut, and then the plasma cutting torch is moved to cut the product.

When forming a hole in a material to be cut, a melt or an oxide of a base material is generated as the hole grows, and the melt is discharged to the surface of the material to be cut and solidified until the hole penetrates. Accumulate or scatter in the air. For this reason, when the plasma cutting torch is held at the height at which it was cut and a hole was drilled, melts or spatters adhered to the plasma cutting torch and damaged, or the plasma cutting torch was cut. There is a possibility that a double arc may be generated by coming into contact with the discharged matter on the surface of the material.

Various methods for solving the above problems and forming a hole in the material to be cut and at the same time starting the cutting, for example,
A main arc is formed with the plasma cutting torch held at a predetermined height above the surface of the material to be cut, and the plasma cutting torch is lowered as the drilling progresses, and at the same time it is moved at a low speed in the desired direction to form a hole. A descending running start method of moving at a predetermined speed when penetrating, forming a main arc in a state of being held at a predetermined height, after the hole penetrates,
A fixed position start method in which the plasma cutting torch is moved down in the desired direction at the same time at the same time, a main arc is formed while the plasma cutting torch is held at a predetermined height, and the plasma cutting torch is moved up at a low speed while moving once. , When the hole penetrates, lower the plasma cutting torch to a predetermined height,
There has been proposed a re-climbing running start method and the like in which when the descent is completed, the descent is moved in a target direction at a predetermined speed.

[0005]

No matter which of the above-mentioned starting methods is adopted, the melt generated by the formation of the holes is discharged to the surface of the material to be cut and solidified and accumulated. The solidified discharge is affected by the gas flow injected from the plasma cutting torch and spreads over a wide area at a low height.Therefore, the target cutting is a small circle including the hole position, or the target cutting line is the hole. Emissions may accumulate on the cutting line when approaching the location. In this case, when the target cutting line is cut, the discharged product is cut at the same time, which may cause a problem that a notch is formed in the product.

Therefore, in the case of performing cutting that may cause the above problems, after forming a hole in the material to be cut, the operation of the plasma cutting torch is once interrupted and the discharge accumulated on the surface of the material to be cut is discharged. In reality, the object is removed, and then the plasma cutting torch is activated again to perform the cutting.

The object of the present invention is to eliminate the influence of this discharge even if the discharge generated along with the formation of holes and discharged on the surface of the material to be cut and solidified and accumulated is on the target cutting line. It is an object of the present invention to provide a cutting start method in plasma cutting capable of starting cutting and a plasma cutting apparatus for carrying out this method.

[0008]

In order to solve the above problems, a cutting start method in plasma cutting according to the present invention is
A method of starting cutting from the surface of a material to be cut using a plasma cutting torch, wherein a main arc is formed between an electrode and the material to be cut to penetrate the material to be cut at a predetermined position of the material to be cut. After forming the hole, the periphery of the hole containing a part or all of the discharge discharged on the surface of the material to be cut along with the formation of the hole is cut, and the cutting to the target cutting line is started following the cutting. It is characterized by doing.

The plasma cutting apparatus according to the present invention further includes a plasma cutting torch, a moving device including a main body and a carriage for moving the plasma cutting torch along two directions orthogonal to each other, and cutting from the surface of the material to be cut. When the plasma cutting torch is moved to a predetermined cutting start position, the operation of the moving device is controlled, and when the plasma cutting torch reaches the predetermined cutting start position, a hole is formed in the material to be cut. After controlling the operation of the plasma cutting torch and forming a hole, the periphery of the hole containing a part or all of the discharge discharged to the surface of the material to be cut is cut and the target cutting line is continued after the cutting. And a control device for controlling the operation of the moving device so as to start the cutting of the moving device.

In the above plasma cutting apparatus, a nozzle for injecting a fluid is arranged adjacent to the plasma cutting torch, and after cutting the periphery of the hole containing the discharged matter discharged on the surface of the material to be cut, the nozzle is discharged. It is preferable to control so that the fluid is ejected from.

[0011]

[Operation] In the cutting start method in the above plasma cutting,
A main arc is formed between the electrode attached to the plasma cutting torch (hereinafter simply referred to as the "torch") and the material to be cut,
A hole penetrating the material to be cut is formed at a predetermined position on the scrap side of the material to be cut, and thereafter, a part or all of the discharge product discharged to the surface of the material to be cut due to the formation of the hole is included. By cutting the periphery of the hole, the peripheral portion of the cut hole can be removed from the material to be cut. Further, the target cutting can be performed by starting the cutting of the target cutting line subsequent to the cutting around the hole.

That is, a molten material and an oxidized molten material of the base material are generated along with the formation of the holes, and these molten materials flow out along the surface of the formed hole and are discharged to the surface of the material to be cut. . The discharged melt is immediately cooled by the atmosphere and solidified. For this reason, the discharged material is not re-welded on the entire contact surface with the surface of the material to be cut, but is re-welded on the edge of the formed hole.

Therefore, if the re-welded portion of the discharged material and the material to be cut is separated, the solidified discharged material can be easily removed from the surface of the material to be cut. That is, by cutting around the formed hole including a part or all of the discharged material, the re-welded portion between the discharged material and the material to be cut can be cut and removed from the material to be cut. In particular, when a part of the discharged material is cut and cut, the remaining discharged material does not have a portion to be re-welded with the material to be cut, so by applying a slight force, for example, the action of the air flow injected from the torch. Can be removed from the surface of the material to be cut.

In the above plasma cutting device, when the cutting is started from the surface of the material to be cut, the control device controls the operation of the moving device to move the torch to a predetermined cutting start position, and the torch is moved to the cutting start position. When it reaches, the operation of the torch is controlled to form a hole in the material to be cut, and then the operation of the moving device is further controlled to include a part or all of the discharge discharged to the surface of the material to be cut. It is possible to cut around the hole and then start cutting to the target cutting line.
That is, the above cutting start method can be implemented.

In the above plasma cutting device, when the nozzle is arranged adjacent to the torch and the cutting of the periphery of the hole by the torch is completed and the nozzle is operated to eject the fluid, the material to be cut is Emissions left on top can be forcibly eliminated.

[0016]

Embodiments of the above-described cutting start method and plasma cutting apparatus will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a case where the cutting start method according to the present invention is applied to a running start method, FIG. 2 is a diagram illustrating a case where the cutting start method according to the present invention is applied to a fixed position start method, and FIG. FIG. 4 is a diagram illustrating the configuration of the plasma cutting device, and FIG. 4 is a block diagram of a control system of the plasma cutting device.

A cutting start method according to the present invention is shown in FIG.
This will be described with reference to FIG. First, a cutting start method in the case of adopting a descending running start method or a re-raising running start method will be described with reference to FIG.

In the running start method, after forming the main arc, the torch is moved at a low speed in the intended cutting direction. As shown in FIG.
The hole 2 formed in the hole gradually becomes deeper in the moving direction of the torch 3. In this starting method, since the slope 2a is formed on the rear side as the torch 3 moves, the melt of the base material and the oxidized base material flows along the slope 2a and is discharged to the surface of the material 1 to be cut. To form a solidified effluent mass 4.

As described above, since the melted discharge flows along the slope 2a, it is firmly re-welded at the upper edge 2b of the hole 2. Therefore, after forming the hole 2 penetrating the material to be cut 1, as shown in FIG. 3A, the periphery of the hole 2 including a part or the whole of the mass 4 of the discharged matter is cut to obtain a mass. It is possible to cut the re-welded portion between the cutting edge 4 and the upper edge 2b of the hole 2 into a circular shape to separate it from the material to be cut 1 and to remove the lump 4 left from the material to be cut.

That is, when the upper edge 2b around the hole 2 is cut so as to include a part or all of the lump 4 of the discharged material, the periphery of the hole 2 is cut into a substantially circular shape centered on the hole 2. Therefore, the cut circular member is dropped and removed from the material 1 to be cut as scrap in a state where a part or all of the lump 4 is re-welded to the upper edge 2b of the hole 2. When the lump 4 is left on the material 1 to be cut by the cutting, the lump 4 is blown away by the gas injected from the torch 3 and is removed from the material 1 to be cut.

Next, a cutting start method when the fixed position start method is adopted will be described with reference to FIG. This fixed position start method is to form the hole 2 in the material 1 to be cut without moving the torch after forming the main arc.

The molten material of the base material and the oxide generated during the formation of the hole 2 is discharged in a relatively wide range around the hole 2 and solidifies and accumulates, and the mass of the discharged material centered around the hole 1 is discharged. 4 is formed. The mass 4 is re-welded with the upper edge of the hole 2 and integrated with the material 1 to be cut. Therefore, by cutting the periphery of the hole 2 including a part or all of the lump 4, the re-welded portion between the lump 4 and the upper edge 2b of the hole 2 is cut into a circular shape as in the above-described embodiment. It is possible to separate the lump 4 left from the cut material 1 and to leave it from the surface of the cut material.

Next, the plasma cutting device will be described with reference to FIGS. Main body 12 on rail 11 laid in parallel
A moving device 14 including a carriage 13 and a carriage 13 is mounted. The main body 12 is configured as a gate type frame having a saddle 12a and a garter 12b arranged in a direction orthogonal to the rail 11. A traverse rail 15 is provided on the garter 12b, and a carriage 13 having the torch 3 attached to the traverse rail 15 is mounted so as to traverse.

A traveling motor 16 is arranged on the saddle 12a of the main body 12, and a traverse motor 17 is arranged on the carriage 13. Therefore, by controlling the driving of the traveling motor 16 and the traverse motor 17, the torch 3 can be moved in a desired direction.

A nozzle 18 is provided adjacent to the torch 3. This nozzle 18 is a fluid (eg compressed air, oxygen, etc.)
Has a function of removing the lump 4 of the discharged matter left on the material to be cut 1 when the material is jetted to make a hole in the material to be cut 1 and after cutting the periphery of the hole 2 after the drilling, It is connected to an air compressor or a blower via a solenoid valve (not shown).

A control device for controlling the operation of the traveling motor 16, the traverse motor 17, the torch 3, the nozzle 18, etc. is built in a control panel 19 mounted on the saddle 12a of the main body 12. This control device is constituted by a numerical control (NC) device, and as shown in FIG. 4, a calculation unit 21a, a cutting program and a program and a hole for forming a hole 2 in the material 1 to be cut at the start of cutting. A storage unit 21 in which a program or the like for cutting the periphery of the hole 2 is written subsequent to the formation of 2.
b, the control unit 21 including a temporary storage unit 21c that temporarily stores cutting information such as the plate thickness and cutting speed of the material 1 to be cut, and the material 1 to be cut
It has an input device 22 for inputting the cutting information and graphic information to be cut, and an interface 23. Incidentally, 24 is a driver of the traveling motor 16, and 25 is a driver of the traverse motor 17.

In the plasma cutting apparatus configured as described above, cutting information such as the plate thickness and cutting speed of the material to be cut 1 by the input device 22, graphic information according to the shape of the graphic to be cut,
Information on the drilling position, information on whether or not to cut the periphery after drilling, etc. are input and stored in the temporary storage unit 21c.

Next, when a disconnection start signal is generated from the input device 22, the disconnection program written in the storage unit 21b,
And the traveling motor from the control unit 21 according to the entered information.
Drive signals for 16 and traverse motor 17 are generated,
12 and the carriage 13 move to move the torch 3 to a predetermined drilling position.

When the torch 3 reaches a predetermined position, the control unit
An operation start signal is generated from 21 to the torch 3, a pilot arc is formed inside the torch 3, a main arc is continuously formed between the torch 3 and the material to be cut 1, and a running start method or a fixed position start method is performed. To be done.

When the information indicating that the peripheral cutting is to be performed after the hole is drilled, a drive signal for cutting the small circle is generated from the control unit 21 to the traveling motor 16 and the traverse motor 17 according to a preset program. Then, the periphery of the hole 2 including a part or the whole of the discharged matter discharged to the material to be cut 1 is cut. When the cutting around the hole 2 is completed, the control unit 21
From this, an operation signal is generated to the nozzle 18, and in response to this signal an electromagnetic valve (not shown) is opened for a predetermined time to inject compressed air, and the lump 4 of the discharged matter left on the material 1 to be cut is eliminated.

After that, a drive signal for moving the torch 3 in the direction of the target cutting line corresponding to the inputted figure is generated in each of the motors 16 and 17, and the figure can be cut.

[0032]

As described above in detail, in the cutting start method for plasma cutting according to the present invention, one of the discharged substances discharged around the material to be cut around the hole formed in the material to be cut. Even if a part of the discharge is left on the material to be cut by removing the re-welded portion of the discharge and the material to be cut as scrap by cutting including the part or the whole, This exhaust can be blown off by the gas injected from the torch. Therefore, even when the punching position is close to the target cutting line, the discharged matter does not adversely affect the cutting.

In the plasma cutting apparatus according to the present invention,
By controlling the operation of the torch and the moving device for moving the torch in the two orthogonal directions, the control section controls the drilling of the material to be cut and the continuous cutting of the periphery of the hole.

By providing a nozzle for ejecting fluid adjacent to the torch, when the periphery of the hole is cut,
It is characterized in that the discharged matter left on the material to be cut can be forcibly removed from the material to be cut.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a case where a cutting start method according to the present invention is applied to a running start method.

FIG. 2 is a diagram illustrating a case where the cutting start method according to the present invention is applied to a fixed position start method.

FIG. 3 is a diagram illustrating a configuration of a plasma cutting device.

FIG. 4 is a block diagram of a control system of the plasma cutting device.

[Explanation of symbols]

 1 material to be cut 2 hole 2a slope 2b upper edge 3 torch 4 waste mass 11 rail 12 body 12a saddle 12b garter 13 carriage 14 moving device 15 traverse rail 16 travel motor 17 traverse motor 18 nozzle 19 control panel 21 control unit 21a calculation 21b Storage 21c Temporary storage 22 Input device 24, 25 Driver

Claims (3)

[Claims] 1. A method of starting cutting from the surface of a material to be cut using a plasma cutting torch, wherein a main arc is formed between an electrode and the material to be cut, and the material to be cut is cut at a predetermined position. After forming a hole that penetrates the material, cut around the hole containing a part or all of the discharge discharged to the surface of the material to be cut in accordance with the formation of the hole, and then perform the target cutting after the cutting. A method for starting cutting in plasma cutting, characterized by starting cutting for a wire. 2. A plasma cutting torch, a moving device including a main body and a carriage for moving the plasma cutting torch along two directions orthogonal to each other, and the plasma cutting torch when starting cutting from the surface of a material to be cut. Controlling the operation of the moving device so as to move it to a predetermined cutting start position, and operating the plasma cutting torch so as to form a hole in the material to be cut when the plasma cutting torch reaches the predetermined cutting start position. To cut the periphery of the hole containing part or all of the discharge discharged to the surface of the material to be cut after forming the hole and to start cutting to the target cutting line subsequent to the cutting. A plasma cutting device having a control device for controlling the operation of a moving device. 3. A nozzle for ejecting a fluid is arranged adjacent to the plasma cutting torch, and the fluid is ejected from the nozzle after cutting around the hole containing the discharged matter discharged on the surface of the material to be cut. The plasma cutting device according to claim 2, wherein the plasma cutting device is controlled as follows.