JP2000343227A - Cutting method of workpiece with plasma arc cutting device and plasma arc cutting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a cutting work process by cutting a remained uncut part at a single work process, and eliminating a secondary work which is carried out as a separate process. SOLUTION: In the method of cutting a workpiece W with a plasma arc cutting device which cuts a workpiece W by moving a plasma torch 7 to a terminal point of cutting different from a starting point of cutting across a cut-off position where cut-off grooves formed by cutting the workpiece by a plasma arc 29 cross each other while a plasma torch 7 generating a plasma arc 29 is moved from a starting point of cutting and the workpiece W is cut by the plasma arc 29, the plasma torch 7 is returned to a location C beyond the cut-off position along the cut-off groove after moving the plasma torch 7 to the terminal point of cutting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a workpiece cutting method and a plasma processing apparatus in a plasma processing apparatus for cutting a workpiece by a plasma arc, and more particularly, to a plasma capable of cutting a workpiece by a single processing without any uncut portion. An object of the present invention is to provide a workpiece cutting method and a plasma processing apparatus in a processing apparatus.

[0002]

2. Description of the Related Art For example, to cut a work using a plasma processing apparatus, as shown in FIG. 10, a plasma torch is cut from a cutting start point S opened at an arbitrary position of a work W by an arrow shown in FIG. And the workpiece W is moved by the plasma arc generated from the tip of the plasma torch.
And the product 101 is cut off.

Here, as shown in FIG. 11, a cutting start point S and a cutting end point E are provided at a different position not on the cutting groove 103 formed by cutting the work W, and the above-mentioned product 101 is processed. The work W is cut by employing a so-called off-line piercing method.

More specifically, while moving the plasma torch 105 shown in FIG. 12 from the cutting start point S in the direction shown by the arrow in FIG.
07, the workpiece W is cut, the plasma torch 105 is cut by the plasma arc 107, and the cut groove 103 is cut through an intersecting cut-off portion to reach the cutting end point E. The cutting process is completed by moving.

[0005]

However, at the cut-off portion where the cutting grooves 103 intersect as described above, the work W
May be left uncut, and the product 101 may be partially connected to the workpiece W. For example, as shown in FIGS. 11 and 12, when the upper end points of both ends of the opening of the cutout portion are A and B, and the lower end points are A ′ and B ′, the plasma arc 107
Since the trailing end follows the moving speed of the torch 05, the trailing end is delayed with respect to the torch leading end. That is, the plasma arc 107
Is that when the torch tip side reaches point A, the tail end side has not yet reached point A '.

When the plasma torch 105 reaches the cut-off portion, the arc instantaneously shifts from the point A to the point B on the tip side of the torch, and instantaneously falls on the tail end side without passing through the point A '. It moves to B '. Therefore, the vicinity of the point A ′ (the hatched portion in FIGS. 12 and 13) remains without being cut by the plasma arc 107, and the product 101 cannot be separated from the work W. In particular, in the case of a stainless steel work W having a thickness of 10 mm or more, a cutting failure due to the above uncut portion easily occurs. Therefore, conventionally, the remaining portion is cut in another step.

Accordingly, the present invention has been proposed to solve the above-mentioned problems, and it is an object of the present invention to provide a workpiece cutting method and a plasma processing apparatus in a plasma processing apparatus which eliminates cutting defects and does not require secondary processing. is there.

[0008]

According to the first and third aspects of the present invention, the plasma torch is first moved to a cutting end point by passing through a cut-off portion where cutting grooves intersect with each other, and then the plasma torch is moved. Is returned along the cut groove to a position beyond the cut-off portion.

As described above, even if the plasma arc first passes through the cut-off portion and remains uncut, if the plasma torch is returned to a position beyond the cut-off portion along the cutting groove, the outgoing plasma arc is removed. Is followed in the opposite direction, the arc spreads over the uncut portion (the arc concentrates), and the uncut portion is cut.

[0010] In the present invention, the plasma torch may have an appropriate number of arbitrary positions between a predetermined position before the cut-off portion where the cutting grooves intersect and the position of the cut-off portion. After temporarily stopping the plasma torch while holding the arc, the plasma torch is moved to the cutting end point beyond the cut-off portion.

By doing so, there is no cut in the cut-off portion and the cut is made.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

As shown in FIGS. 1 and 2, the plasma processing apparatus according to the present embodiment has a work clamper 3 for clamping a work (not shown) on a work table 1.
It has. The work clamper 3 clamps the work and positions and fixes the work on the work table 1.

As shown in FIGS. 1 and 2, a plasma torch 7 serving as a processing head is movably provided above the work table 1. The plasma torch 7 is guided by a guide rail 17 provided on the floor surface 9 on a frame 11 erected on the floor surface 9 and is movable in the X direction by an X-axis driving servomotor 13. The beam member 15 is provided. And
The plasma torch 7 includes a Y-axis driving servomotor 1
9 makes it movable in the Y direction along the beam member 15.

A control unit 21 for controlling the plasma torch 7 so as to be movable in the X and Y directions is connected to the plasma processing apparatus. In the control unit 21, FIG.
As shown in the figure, the plasma torch 7 is moved from the cutting start point S to the product contour shape as shown by the arrow, and the plasma torch 7 is caused to pass through the cut-off portion where the cutting groove 23 formed by the plasma arc intersects, thereby starting the cutting. After moving the plasma torch 7 to a cutting end point E different from the point S, control is performed so that the plasma torch 7 is returned to a position beyond the cutout portion along the cutting groove 23 along the same path. .

Specifically, as shown in FIGS. 4 and 6,
The upper end points of both ends of the cut-off portion where the cut grooves 23 intersect each other are A and B, the lower end points are A 'and B', the cut start point is point S, the cut end point is point E, and the cut end portion is Point C beyond the point
Then, the plasma torch 7 is moved from the point C to the cutting end point E through the points A and B as shown in FIG. 5 and then returned to the point C again. In addition, from point A to point C
The distance L is a distance that can cover at least the part that has not been cut.

In order to return the plasma torch 7 from the cutting end point E to the point C, a conventional program is executed by using a CAM (Computer).
Aided Manufacturing) or G code correction.

As shown in FIGS. 1 and 2, the control section 21 is provided with a memory 25 which is a position storage means for detecting and storing the moving position of the plasma torch 7. The memory 25 stores position information in the X direction and the Y direction in which the plasma torch 7 sequentially moves.

Next, a method of cutting a workpiece using the above-mentioned plasma processing apparatus will be described.

First, the work W clamped by the work clamper 3 is positioned at a predetermined position on the work table 1. Next, in response to a command from the control unit 21, the plasma torch 7 is driven by the X-axis driving servomotor 13 and the Y-axis.
The workpiece W is sent to the cutting start point S of the workpiece W by the axis driving servomotor 19. At this time, the movement position of the plasma torch 7 is stored in the memory 25.

Then, the plasma torch 7 is moved in the direction indicated by the arrow as shown in FIG. 3 in response to a command from the control section 21 and moves to the cutting end point E through the cut-off section. I'm sullen. At this time, the plasma torch 7 moves from the point C to the cutting end point E, and the work W is cut by the plasma arc 29.
The 'part may remain without being cut. Therefore, the plasma torch 7 is returned from the cutting end point E to the point C where the plasma torch 7 is stored in the memory 25 along the cutting groove 23 again.

Then, as shown in FIG. 6, the direction of the plasma arc 29 generated from the plasma torch 7 at this time is such that the plasma torch 7 is moved from the point C to the cutting end point E as shown in FIG. In this case, the direction of the plasma arc 107 is reversed, and the arc on the tip side of the torch shifts from the point B to the point A at a stretch, but the arc on the tail end side is the uncut portion of the point A ′ (the hatched portion in FIG. 6). The uncut portion can be cut by the plasma arc 29 because the portion passes as if licking.

As described above, since the plasma torch 7 is returned to a position beyond the cut-off portion through the same processing path and is re-processed, a portion which has not been completely cut by the first processing can be cut. There is no need to separately cut off the work, and the work cutting work can be simplified.

For example, in the above-described embodiment, the plasma torch 7 is returned from the cutting end point E to the point C. However, as shown in FIG. Is also good. Alternatively, when moving the plasma torch 7 from the point C to the point A, the processing speed is reduced and the point A is reduced.
Then, the moving speed may be set to a speed close to zero, and the uncut portion may be cut. In addition, several in-positions are inserted between point C and point A to reduce the processing speed,
The uncut portion may be cut.

Further, as shown in FIG. 3, the controller 21 moves the plasma torch 7 from the cutting start point S to the product contour shape as shown by the arrow, and cuts the plasma torch 7 by a plasma arc. Before passing through the cut-off portion, the plasma torch 7 is temporarily stopped while holding the arc at an arbitrary position between a preset position before the cut-off portion and the position of the cut-off portion. After that, the plasma torch 7 is controlled to move beyond the cut-off portion to the cutting end point.

Specifically, as shown in FIGS. 7 and 8, the upper and lower ends of the open end of the cut-off portion where the cutting grooves 23 intersect each other are I and I ', and the cut-off portion is located in front of the cut-off portion. A preset position, for example, a position of 5 mm is set as a point F. Then, the plasma torch 7 is temporarily stopped while the arc is held at an appropriate number of arbitrary positions between the points I and F, for example, points G and H.

Next, by moving over the cut-off portion to the cutting end point E and performing cutting, the cut-off portion I '
It is possible to eliminate the uncut portion at the point. Therefore,
The secondary processing for cutting off which has been performed in a separate step can be eliminated.

The cutting processing shown in FIGS. 7 and 8 can be executed by a processing program shown in FIG. 9 using, for example, CAM or NC code. The stop is temporarily performed at the two points G and H. However, the stop may be performed at any number of points as long as the number is one or more. In this case, the work W
As a thick plate of mild steel. Further, although the description has been made using G00 (in-position) in order to improve the arc delay, the plasma torch 7 may be temporarily stopped by another method such as G code or M code.

[0029]

The present invention is embodied in the form described above and has the following effects.

According to the method for cutting a workpiece in the plasma processing apparatus according to the first aspect of the present invention, after moving the plasma torch to the cutting end point, the plasma torch is moved along the cutting groove to a position beyond the cut-off portion. Since the plasma torch is returned, the uncut portion can be cut off when the plasma torch is returned, and the secondary processing for cutting off performed in a separate process can be eliminated.

According to the method for cutting a workpiece in the plasma processing apparatus according to the second aspect of the present invention, an appropriate number of plasma torches are set between a preset position before the cut-off portion and the position of the cut-off portion. After suspending the plasma torch while holding the arc at an arbitrary position, the plasma torch is moved to the cutting end point beyond the cut-off portion, so that the uncut portion at the cut-off portion is left uncut. In this case, the secondary processing for cutting off which has been performed in a separate process can be eliminated.

According to a third aspect of the present invention, there is provided a plasma processing apparatus, comprising: a position storage means for detecting and storing a moving position of a plasma torch; Through the cut-off part where the cutting grooves formed by cutting each other intersect,
After moving the plasma torch to a cutting end point different from the cutting start point, a control unit that controls the plasma torch to return to a position beyond the cut-off portion along the cutting groove is provided. Thereby, the part left uncut by one processing can be cut without performing the secondary processing for cutting off.

According to the workpiece cutting apparatus in the plasma processing apparatus of the present invention, the position storage means for detecting and storing the moving position of the plasma torch, and moving the plasma torch from a cutting start point to perform the above-mentioned operations. In a state where the arc is held at an appropriate number of arbitrary positions between a preset set position before the cut-off portion where the cut grooves formed by cutting with the plasma arc intersect with each other and the position of the cut-off portion. After temporarily stopping the plasma torch, by providing a control unit that controls the plasma torch to move to the cutting end point beyond the cut-off unit, the cutting can be performed without any uncut portion in the cut-off unit. And the secondary processing for cutting off, which has been performed in a separate step, can be eliminated.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing a plasma processing apparatus of the present embodiment.

FIG. 2 is a front view schematically showing the plasma processing apparatus of the present embodiment.

FIG. 3 is a diagram showing a moving trajectory of a plasma torch when cutting a workpiece.

FIG. 4 is an enlarged view of a main part of a crossing portion of a cutting groove in a movement locus of the plasma torch shown in FIG.

FIG. 5 is a diagram in which the plasma torch is returned from a cutting end point E to a point C which is a position beyond the cut-off portion again.

FIG. 6 is a diagram showing a movement trajectory of a plasma arc when the plasma torch is returned from a cutting end point E to a point C which is a position beyond the cut-off portion again.

FIG. 7 is an enlarged view of a main part at an intersection of cutting grooves instead of FIG. 4;

FIG. 8 is a diagram showing a state when the plasma torch is moved from a point F to a point I in FIG.

9 is an example of a processing program for moving a plasma torch from point F to point I in FIG.

FIG. 10 is a diagram showing a moving trajectory of a plasma torch when cutting a workpiece by a conventional method.

FIG. 11 is an enlarged view of a main part at an intersection of cut grooves in a movement locus of the plasma torch shown in FIG. 7;

FIG. 12 is a view showing a state in which an uncut portion is formed without being cut by a plasma arc in a conventional cutting method.

FIG. 13 is an enlarged view of a main part showing a state where an uncut portion is formed without being cut by a plasma arc in a conventional cutting method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Work table 7 Plasma torch 21 Control part 23 Cutting groove 25 Memory 27 Product 29 Plasma arc

Claims (4)

[Claims] 1. A cutting section in which a workpiece is cut by a plasma arc while a plasma torch for generating a plasma arc is moved from a cutting start point, and cut grooves formed by the plasma arc intersect. In the plasma processing apparatus for cutting the work by moving the plasma torch to a cutting end point different from the cutting start point, wherein the plasma torch is moved to the cutting end point. Thereafter, returning the plasma torch to a position beyond the cut-off portion along the cutting groove, a workpiece cutting method in the plasma processing apparatus. 2. A cut-off section in which a workpiece is cut by a plasma arc while a plasma torch for generating a plasma arc is moved from a cutting start point, and cut grooves formed by the plasma arc intersect. In the work cutting method in a plasma processing apparatus that cuts the work by moving the plasma torch to a cutting end point different from the cutting start point by passing through the cutting start point, the plasma torch is pre-cut before the cut-off portion. After suspending the plasma torch while holding the arc at an appropriate number of arbitrary positions between the set position and the position of the cut-off portion, cut the plasma torch beyond the cut-off portion A workpiece cutting method in a plasma processing apparatus, wherein the workpiece is moved to an end point. 3. A plasma processing apparatus for cutting a workpiece by a plasma arc generated from the tip of the plasma torch while moving the plasma torch, wherein: a position storage means for detecting and storing a moving position of the plasma torch; The plasma torch was moved to the cutting start point and passed through a cut-off portion where cutting grooves formed by cutting by the plasma arc intersect, and the plasma torch was moved to a cutting end point different from the cutting start point. A plasma processing apparatus further comprising: a control unit that controls the plasma torch to return to a position beyond the cut-off portion along the cutting groove. 4. A plasma processing apparatus for cutting a workpiece by a plasma arc generated from the tip of the plasma torch while moving the plasma torch, wherein: a position storage means for detecting and storing a moving position of the plasma torch; The cutting groove formed by being moved from the cutting start point and cut by the plasma arc has an appropriate number of positions between a preset set position before the cut-off portion and the position of the cut-off portion where the cut grooves intersect each other. After temporarily stopping the plasma torch while holding the arc at an arbitrary position, a control unit that controls the plasma torch to move to the cutting end point beyond the cut-off portion is provided. Plasma processing equipment.