JP2017131897A - Laser processing device and copying control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser processing device for surely executing the copying movement of a laser processing head to a work having an opening part at high speed.SOLUTION: A laser processing device comprises a control part (71) for controlling a head driving part (KD) so as to copy-move a laser processing head (1) for irradiating a work (W) with a laser beam (LZ) to the work (W). The control part (71) determines a maximum hole overlapping distance (Lkma) from among a hole overlapping distance (Lk1-Lkn) being a distance in which a movement projection passage (Rb) overlaps on respective opening parts (Wk1-Wkn) when the movement projection passage (Rb) being projection to the work (W) of a predetermined movement passage (Ra) of the laser processing head (1) crosses a plurality of opening parts (Wk1-Wkn), and determines whether or not the laser processing head (1) can pass through an opening part (Wkma) for imparting the maximum hole overlapping distance (Lkma) by the copying movement, and controls so that the laser processing head (1) is passed by the copying movement on all of the plurality of opening parts (Wk1-Wkn) when determined as being passable by the copying movement.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laser processing apparatus and a scanning control method. In particular, the present invention relates to a laser processing apparatus and a scanning control method for performing a scanning movement of a laser processing head with respect to a workpiece surface having an opening.

When cutting a workpiece with a laser processing device, the movement when moving the laser processing head from the cutting end position to the piercing position that will be the pre-processing of the next cutting processing is based on copying instead of retracting movement. It may be an action.
The retreat movement is a movement in which the laser processing head is linearly moved at a rapid feed speed at a position where the nozzle tip is sufficiently separated from the workpiece surface.
The copying movement is a movement mode in which the laser machining head is moved along the shape of the workpiece surface while maintaining the distance from the workpiece surface at the nozzle tip to the same predetermined distance as that at the time of cutting, for example.

  The scanning movement speed is slower than the retraction movement speed to avoid collision between the nozzle and the work. However, if there are many parts to be processed on the work, if the retraction operation is executed each time, the laser machining head is moved to the work. There may be a case where the loss in the moving time for moving away from the surface becomes larger.

As described above, when the movement from the cutting end position to the next piercing position is performed by copying, if there is an opening on the workpiece surface, the laser processing head is caused to enter the opening for control when passing through the opening. It will also move in the direction.
For this reason, when passing through the opening, it is necessary to devise a method that considers movement toward the opening.
For example, Patent Document 1 discloses a control method for moving a laser processing head along a workpiece having a hole.

The control method described in Patent Document 1 includes a detection value of a displacement sensor that measures a vertical distance from the surface of a workpiece that is provided in a laser processing head and is horizontally arranged, or a speed value that is calculated from the detection value. By comparing with the reference detection value, the presence / absence of the workpiece on the tip side of the machining head (whether it is a hole) is determined. When it is determined that the workpiece is not present (a hole), the laser processing head is prohibited from moving up and down. When it is determined that the workpiece is present (removed from the hole), the prohibition of the vertical movement is canceled and the copying movement is performed. It is a method of executing.
Here, the opening includes a deep recess that is substantially regarded as an opening in the control of the copying movement.

JP 2011-034501 A

By the way, in order to improve the operation efficiency of the laser processing apparatus, it is desired that the scanning movement of the laser processing head from the cutting end position to the next piercing position is faster.
In the technique described in Patent Literature 1, when there are a plurality of openings on the copying movement route, the determination operation is executed for each opening. For this reason, when the workpiece that performs the copying movement has a large number of small holes such as punching metal, the number of determination operations for the movement distance increases, and the processing load of the control device increases and the control reliability is increased. There is room for improvement in that there is a risk of lowering and it is difficult to increase the speed.

  Accordingly, an object of the present invention is to provide a laser processing apparatus and a scanning control method capable of performing a scanning movement of a laser processing head with respect to a workpiece having an opening at a high speed and reliably.

In order to solve the above problems, the present invention has the following configuration and procedure.
1) a laser processing head for irradiating a workpiece with laser light;
A head drive unit that moves the laser processing head in three axial directions of XYZ;
A scanning control unit that controls the head driving unit to move the laser machining head in accordance with the workpiece;
With
The copying control unit
When a movement projection path, which is a projection of the predetermined movement path of the laser processing head onto the workpiece, crosses a plurality of openings, from among the punching distances that are the distances that the movement projection path is applied to each opening. Finding the maximum perforation distance, determining whether the laser processing head can pass through the opening that gives the maximum perforation distance, and if it is determined that it can pass, all of the plurality of openings Is a laser processing apparatus that controls to pass through by copying movement.
2) The copying control unit
The minimum hole contact distance is obtained from the hole contact distances, and it is determined whether or not the laser processing head can pass through the scanning movement through the opening that gives the minimum hole contact distance. In this case, in the laser processing apparatus according to 1), the laser processing head is allowed to pass through all of the plurality of openings by a retreating movement that moves at a position farther from the workpiece than the scanning movement. is there.
3) The copying control unit
The first opening and the second opening that are adjacent to each other among the plurality of holes are separated by one when the separation distance between the first opening and the second opening is smaller than a predetermined distance. The laser processing apparatus according to 1) or 2), wherein the laser processing apparatus is regarded as an opening and determines whether or not the copying movement is possible.
4) A scanning control method for moving a laser processing head that irradiates a workpiece with a laser beam in accordance with the workpiece,
When a movement projection path that is a projection of the predetermined movement path of the laser processing head onto the workpiece crosses a plurality of openings,
Obtaining a maximum hole distance from a hole distance that is a distance that the moving projection path is applied to each opening; and
Determining whether or not the laser processing head can pass by scanning movement through the opening that gives the maximum punching distance;
A step of determining that all of the plurality of openings are allowed to pass by copying movement when it is determined that they can pass;
Is a copying control method characterized by including:
5) obtaining a minimum hole contact distance from the hole contact distances;
Determining whether or not the laser processing head can pass by scanning movement through the opening that gives the minimum punching distance;
Determining that the laser processing head is allowed to pass through a retreating movement that moves the laser processing head at a position farther from the workpiece than the copying movement when it is determined that the scanning movement is impossible. ,
The scanning control method according to 4), including:
6) determining whether or not a separation distance between the adjacent first opening and second opening of the plurality of openings is smaller than a predetermined distance;
4) or wherein the first opening and the second opening are regarded as one opening when it is determined to be small, and it is determined whether or not the scanning movement is possible. The scanning control method according to 5).

  According to the present invention, it is possible to obtain an effect that the scanning movement of the laser processing head relative to the workpiece having the opening can be performed at high speed and reliably.

FIG. 1 is a block diagram for explaining a configuration of a laser processing apparatus 51 which is an example of a laser processing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic vertical sectional view for explaining the scanning movement of the laser processing head 1 in the laser processing apparatus 51. FIG. 3 is a flowchart for explaining a mode setting procedure by the copying control unit 74. FIG. 4 is a top view for explaining the case where the movement projection path Rb crosses one hole. FIG. 5 is a cross-sectional view at the Sec5-Sec5 position in FIG. FIG. 6 is a diagram for explaining the retraction movement of the laser processing head 1 along the retraction path Rt. FIG. 7 is a top view for explaining the movement projection path Rb crossing the two holes. FIG. 8 is a cross-sectional view at the Sec8-Sec8 position in FIG. FIG. 9 is a flowchart for explaining a procedure for determining and determining a moving method on the moving projection path Rb across two holes. FIG. 10 is a diagram for explaining the moving method determined and determined by the procedure shown in FIG. FIG. 11 is a top view for explaining the movement projection path Rc across three or more holes. FIG. 12 is a table for explaining the determination procedure of the moving method when the laser processing head 1 passes through three or more holes in the moving projection path Rc. FIG. 13 is a flowchart for explaining the determination procedure shown in the table of FIG. FIG. 14 is a flowchart for determining processing when the separation distance Ld between two adjacent holes is smaller than the return distance Lf. FIG. 15 is a top view for explaining a modified example of the procedure for determining the moving method of the laser processing head 1.

A configuration of a laser processing apparatus 51 as an example of the laser processing apparatus according to the embodiment of the present invention will be described with reference to the block diagram of FIG.
The laser processing device 51 includes a laser processing machine 61 and a control device 71 that controls the operation of the laser processing machine 61.
The laser beam machine 61 includes an X-axis motor M1 and a Y-axis motor M2 that move the workpiece W relatively to the X axis and the Y axis on a work table (not shown). Hereinafter, they are simply referred to as a motor M1 and a motor M2.

The laser processing machine 61 includes a laser processing head 1 having a nozzle 1n at a lower portion.
Laser light LZ is irradiated in a direction orthogonal to the surface Ws of the workpiece W from the tip 1np of the nozzle 1n.
In the following description, the surface Ws is also referred to as the upper surface Ws, assuming that the workpiece W is horizontally disposed and the laser light Lz is irradiated in the vertical direction.
The laser processing head 1 includes a distance sensor 2 that measures a gap G that is a distance (height) between the tip 1np of the nozzle 1n and the upper surface Ws of the workpiece W.

The laser processing machine 61 further contacts and disconnects the laser processing head 1 with respect to the workpiece W, a laser light source 3 that supplies laser light to the laser processing head 1, an assist gas source 4 that supplies assist gas to the laser processing head 1, and the laser processing head 1. Z-axis motor M3 (hereinafter referred to as motor M3) that moves in the vertical direction.
The motors M1 to M3 constitute a head drive unit KD that moves the laser processing head 1 in the XYZ triaxial directions.

The distance sensor 2 outputs the measured distance to the control device 71 as gap information J1.
Encoders M1e to M3e are attached to the motors M1 to M3, respectively, and driving amounts of the motors M1 to M3 are output to the control device 71.

The control device 71 includes a CPU (central processing unit) 72, a storage unit 73, and a copying control unit 74.
The CPU 72 mainly controls the overall operation of the laser processing apparatus 51.
The storage unit 73 stores a machining program PG supplied from the outside to the control device 71 and workpiece information J2 including information such as the shape and material of the workpiece W to be machined by the machining program PG.

  The copying control unit 74 controls copying movement that moves the laser processing head 1 along the surface shape while maintaining a predetermined gap G with respect to the surface Ws of the workpiece W. In addition, here, the description will be made assuming that the copying control unit 74 also controls the retreat movement operation that moves at a high speed at the upper end position of the vertical movement stroke that is higher than the position of the copying movement (far from the workpiece W). The retreat movement may be mainly controlled by the CPU 72.

  The machining program PG stored in the storage unit 73 includes machining conditions related to laser machining such as the output of the laser beam LZ, the moving speed of the laser machining head 1 during machining, and the gap G during machining, and the direction of each axis. Commands such as a movement command, a laser beam LZ ON / OFF command, and a scanning control execution command.

Next, the operation of the scanning movement performed by the laser processing apparatus 51 having the above-described configuration will be described.
First, referring to FIG. 2, the laser processing head 1 is moved from a cutting end position Ee after cutting a certain shape to a piercing position Ep that is a position for performing a piercing process that is a pre-processing of the next cutting process. The operation of moving along the movement route Ra will be described.

  In the following description, the movement path Ra means a three-dimensional path including a height component, and a path obtained by projecting the horizontal component of the movement path Ra onto the upper surface Ws of the workpiece W is referred to as a movement projection path Rb (see FIG. 4). ).

FIG. 2 is a schematic vertical sectional view along the moving projection path Rb.
FIG. 2 shows a case where an opening (including a recess) does not exist on the movement projection path Rb and the movement projection path Rb is flat in the workpiece W.
In FIG. 2, the horizontal direction is H and the vertical direction is V, which is defined by arrows. The workpiece W is arranged to extend in the horizontal direction, and the laser beam LZ (not shown in FIG. 2) from the nozzle 1n of the laser processing head 1 is directed toward the upper surface Ws of the workpiece W as described above. Irradiation is in a direction perpendicular to the upper surface Ws.

The optimum focal length of the laser beam LZ is different between the cutting process using the laser beam LZ and the piercing process. Specifically, since the optimum focal length is longer in the piercing process, the distance (height) from the upper surface Ws of the workpiece W to the tip 1np of the nozzle 1n is greater in the piercing process than in the cutting process. Long (high) setting control.
That is, the gap G is larger in the piercing gap Gp in the piercing process performed at the beginning of the hole processing than the cutting gap Gc in the cutting process.

When the CPU 72 moves the laser processing head 1 to the cutting end position Ee through the cutting process, the supply of the laser light and the assist gas from the laser light source 3 and the assist gas source 4 is stopped.
The CPU 72 controls the movement of the laser processing head 1 to the piercing position Ep in cooperation with the copying control unit 74.

The copying control unit 74 refers to the machining program PG and the workpiece information J2 stored in the storage unit 73 before the laser machining head 1 performs the cutting process and reaches the cutting end position Ee, until the next piercing position Ep. The information on the surface shape of the workpiece W corresponding to the moving projection path Rb is acquired.
The copying control unit 74 determines in advance from the acquired information which mode A, B1 to B3 the movement to the piercing position Ep is performed in the procedure shown in FIG. 3 which is a flowchart. deep.

The copying control unit 74 first determines whether or not there is an opening on the moving projection path Rb (S1).
Here, the opening is a portion where no workpiece exists, and includes a hole, a cut portion, and the like. Moreover, since the deep recessed part exceeding the measurement range of the distance sensor 2 is also substantially regarded as a hole, it shall be included in the opening here. In the following description, a case where the opening is a hole will be described.
If it is determined that there is no hole, execution of movement in mode A is determined (S2).
If it is determined that there is a hole, the number of holes is determined to branch as follows (S3).
When it is determined that the number of holes is 1, the movement execution in the mode B1 is determined (S4).
When it is determined that the number of holes is 2, the movement execution in the mode B2 is determined (S5).
When it is determined that the number of holes is 3 or more, execution of movement in mode B3 is determined (S6).

That is, in the movement of the laser processing head 1, the laser processing apparatus 51 performs the mode A movement when there is no hole on the movement projection path Rb, and performs the mode B1 movement when there is one hole. The movement of mode B2 is performed when there are two holes, and the movement of mode B3 is performed when there are three or more holes.
Hereinafter, the movement of mode A, mode B1, mode B2, and mode B3 will be described in detail.

(Mode A)
Mode A is a mode in which the laser machining head 1 is moved along.

  The copying control unit 74 drives the motor M1 and the motor M2 to linearly move the laser processing head 1 at a constant speed V1 (hereinafter also referred to as a copying speed V1) toward the piercing position Ep. In this movement, the scanning control unit 74 controls the motor M3 so as to maintain the gap G as a constant scanning gap Ga based on the gap information J1. The scanning gap Ga is set equal to the cutting gap Gc, for example.

  The scanning speed V1 is set at a speed that can maintain the gap G as much as possible without causing the nozzle 1n to collide with an unexpectedly steep convex shape of the upper surface Ws of the workpiece W. For example, it may be set at a lower speed than the moving speed in the retreat movement.

In FIG. 2, when the laser processing head 1 moves by a distance La by the scanning movement and reaches a predetermined ascent start position Eep, the scanning control unit 74 drives the motor M3 in addition to the motor M1 and the motor M2 to drive the laser processing head. Raise 1 diagonally.
The horizontal speed component V2 of the speed Vu, which is the obliquely rising speed, is set as the scanning speed V1. A rising speed V3, which is a speed component in the vertical direction of the speed Vu, is a rising speed under the scanning control.
When the laser processing head 1 reaches the piercing position Ep which is the piercing gap Gp, the movement in the mode A is finished.

The copying control unit 74 obtains the rising start position Eep as follows.
When the horizontal distance between the rising start position Eep and the piercing processing position Ep is Lp,
Since the time for moving the horizontal distance Lp at the scanning speed V1 is equal to the time for moving the difference between the piercing gap Gp and the scanning gap Ga at the rising speed V3,
Lp = V2 * (Gp-Ga) / V3 (Formula 1)
Is calculated as the position indicated by.

(Mode B1)
Next, the movement in mode B1 executed when there is one hole in the movement projection path Rb will be described.
In mode B1, when there is one hole on the moving projection path Rb of the laser processing head 1, the scanning control unit 74 obtains the horizontal distance applied to the hole in the moving projection path Rb, and based on the hole applying distance, In this mode, it is determined and determined whether the laser processing head 1 is allowed to pass through the scanning movement or the retraction movement with respect to the hole.

The movement projection path Rb when executing the mode B1 will be described with reference to FIG.
As shown in FIG. 4, the movement projection path Rb from the cutting end position Ee of the cutting process line Ca to the piercing position Ep in the next cutting process is a straight path, and is indicated by a one-dot chain line arrow.
A hole Wh1 is already formed in the workpiece W, and the movement projection path Rb is set so as to cross the hole Wh1 at a position Eh1 and a position Eh2.

  FIG. 5 is a cross-sectional view at the Sec5-Sec5 position in FIG. 4 and is a view cut along a vertical plane including the moving projection path Rb.

The copying control unit 74 calculates a hole contact distance Lh1 (see FIG. 4) applied to the hole Wh1 on the moving projection path Rb based on the machining program PG and the workpiece information J2.
That is, the horizontal distance between the start position Eh1 and the end position Eh2 of the movement projection path Rb on the hole Wh1 is calculated as the hole distance Lh1.

Here, the copying control unit 74 sets a distance (approach limit) as a minimum value allowed in the distance (height) from the upper surface Ws of the workpiece W to the tip 1np of the nozzle 1n in the scanning movement of the laser processing head 1. Height) is preset as the approach limit gap Gm.
The approach limit gap Gm is set to a value smaller than the scanning gap Ga. An example of the set value is, for example, about 1/2 to 1/3 of the scanning gap Ga.

When the gap G becomes infinite in the gap information J1 from the distance sensor 2 due to the scanning movement, the laser processing device 51 lowers the laser processing head 1 to follow it.
Therefore, when the laser processing head 1 is moved along the movement path Ra, if the lower position of the tip 1np of the nozzle 1n enters the hole beyond the position Eh1, the gap G in the gap information J1 from the distance sensor 2 is substantially changed. Become infinite.
In order to follow this, the laser processing head 1 moves at a scanning speed V1 in the horizontal direction and descends at a substantially constant lowering speed V4 (see arrow instruction Da).

  Therefore, if the scanning control unit 74 moves the hole hooking distance Lh1 at the scanning speed V1, the workpiece at the tip 1np of the nozzle 1n at the position Eh2 that is the edge of the portion where the workpiece W exists from the hole Wh1. It is determined whether or not the height from W becomes less than the approach limit gap Gm due to the descent. That is, it is determined whether or not the following (Expression 2) is satisfied.

Assuming that the time for moving the punching distance Lh1 at the scanning speed V1 is time T1 (T1 = Lh1 / V1) and the descending distance of the laser processing head 1 when the punching distance Lh1 is moved is Dd1, Dd1 = V4 × T1. Because
Gm> Ga-V4 * T1 = Ga-Dd1 (Formula 2)
It is.

When (Formula 2) is not satisfied (see FIG. 5), the copying control unit 74 determines that the distance G1 between the tip 1np of the nozzle 1n and the upper surface Ws of the workpiece W at the position Eh2 is equal to or greater than the approach limit gap Gm. This is the case.
In this case, when the laser processing head 1 reaches the position Eh2, the scanning control unit 74 operates the motor M3 to move the laser processing head 1 to a position where the height of the tip 1np from the workpiece W becomes the scanning gap Ga. Increase (see symbol Db).
Thereafter, the laser processing head 1 is moved again along the movement path Ra by the scanning gap Ga, and when reaching the rising start position Eep, the laser processing head 1 is moved upward to the piercing processing position Ep as the piercing gap Gp.

When (Expression 2) is satisfied (see FIG. 6), that is, the scanning control unit 74 determines that the distance G1 between the tip 1np of the nozzle 1n and the upper surface Ws of the workpiece W at the position Eh2 is less than the approach limit gap Gm. In this case, the copying control unit 74 executes the movement of the moving path Ra of the laser processing head 1 including the retracting movement.
The retreat path Rt, which is a retreat movement path, is a path that has a height position different from that of the movement path Ra, is located farther (higher) than the movement path Ra than the work W, and the movement projection path Rb is the same. is there.
That is, as shown in FIG. 3, in mode B1, it is determined whether or not (Equation 2) is satisfied (S4-1), and if satisfied, the retreat movement is executed (S4-2), and if not satisfied, , (S2) and the mode A which is a copying movement is executed.

FIG. 6 is a diagram for explaining the retreat movement that moves along the retreat path Rt.
When the laser processing head 1 reaches the position Eh1, the copying control unit 74 cancels the copying control and shifts the movement of the laser processing head 1 to the retreat movement through the retreat path Rt.

The retreat movement is a movement in which the laser processing head 1 is raised to a retreat height that is the uppermost position of the movement stroke in the vertical direction, and then moved horizontally at the fast feed speed V5.
The retreat height is a distance between the tip 1np of the nozzle 1n and the upper surface Ws of the work W, and is indicated here as a retreat gap Gt.

  When the laser processing head 1 reaches the piercing position Ep as the retraction gap Gt by the horizontal movement in the retreat movement, the copying control unit 74 resumes the copying control, drives the motor M3, and the tip of the nozzle 1n. The retraction movement is completed by lowering at a lowering speed V4 so that the distance between 1 np and the upper surface Ws of the workpiece W becomes the piercing gap Gp.

As described above, when there is one hole on the movement projection path Rb from the cutting end position Ee to the next piercing processing position Ep, the scanning control unit 74 performs laser processing based on the processing program PG and the workpiece information J2. The movement of the head 1 is selectively executed from two modes, a first movement mode (mode A) and a second movement mode (mode B1).
The first movement mode (mode A) is a mode in which the copying movement is continued and passed through the hole Wh1.
The second movement mode (mode B1) is a mode in which the copying movement is shifted to the retracting movement and the hole Wh1 is passed.

  That is, the scanning control unit 74 continues the scanning movement when the lowering distance Dd of the laser processing head 1 during the movement of the hole engagement distance Lh1 applied to the hole Wh1 is equal to or smaller than the preset allowable lowering distance Dk. The movement mode (mode A) is selected and executed. In addition, when the allowable lowering distance Dk is exceeded, the second movement mode (mode B1) for shifting from the copying movement to the retracting movement is selected and executed. The allowable descending distance Dk is calculated as Dk = Ga−Gm.

(Mode B2)
Next, the case where two holes exist on the movement projection path Rb in the workpiece W will be described with reference to FIGS.
In mode B2, when there are two holes on the movement projection path Rb of the laser processing head 1, the scanning control unit 74 obtains the hole distance of each of the two holes, and performs the scanning movement for the larger hole distance. It is determined whether or not passage is possible. In this mode, when it is determined that it is possible, the determination is made such that both holes are allowed to pass through the copying movement without determining the smaller hole engagement distance.

FIG. 7 is a top view of the workpiece W as seen from above, as in FIG. In FIG. 7, the movement projection path Rb of the laser processing head 1 from the cutting end position Ee of the cutting processing line Ca to the piercing processing position Ep for the next cutting processing is indicated by a one-dot chain line arrow as a linear path. ing.
FIG. 8 is a vertical sectional view at the Sec8-Sec8 position in FIG.
FIG. 9 is a flowchart for explaining a procedure for determining and determining a moving method when the two holes Wh2 and Wh3 are passed in the movement of the laser processing head 1 along the movement path Ra.
FIG. 10 is a diagram for explaining the moving method determined and determined by the procedure shown in FIG.

In the following description of mode B2 (and mode B3), the horizontal distance required to raise the laser processing head 1 by the allowable lowering distance Dk, which is the difference between the scanning gap Ga and the approach limit gap Gm, is set as the return distance Lf. To do.
Lf is
Lf = Dk × V1 / V3
Indicated by
In the following description, for easy understanding, a case will be described in which the separation distance Ld between a plurality of holes on the moving projection path Rb and the moving projection path Rc (described later) is equal to or greater than the return distance Lf. The case where the separation distance Ld is less than the return distance Lf will be described later.

As shown in FIG. 7, the movement projection path Rb is set linearly from the cutting end position Ee to the piercing position Ep, and crosses the holes Wh2 and Wh3 already formed in the workpiece W.
Specifically, the movement projection path Rb is set so as to cross between the position Eh3 and the position Eh4 for the hole Wh1 and cross between the position Eh5 and the position Eh6 for the hole Wh2.
As described above, the separation distance Ld23 between the hole Wh2 and the hole Wh3 is equal to or greater than the return distance Lf.

As shown in FIG. 9, the copying control unit 74 obtains the hole distance of each hole based on the machining program PG and the workpiece information J2.
Specifically, as shown in FIG. 8, in the movement projection path Rb, a hole distance Lh2 that is a horizontal distance from the position Eh3 at which the movement starts to the hole Wh2 to the position Eh4 at which the movement ends, and the start of the engagement to the hole Wh3. A hole distance Lh3, which is a horizontal distance from the position Eh5 to the position Eh6 at the end of hooking, is obtained (S21).

The copying control unit 74 determines whether or not the punching distance Lh2 is larger than the punching distance Lh3 (S22).
In the case of Yes, Lh2 is set to Lhma and Lh3 is set to Lhmi (S23).
In the case of No, Lh3 is set to Lhma and Lh2 is set to Lhmi (S24).
That is, the larger one of the punching distances Lh2 and Lh3 is Lhma, and the smaller one is Lhmi.

Next, the scanning control unit 74 obtains the descending distance Ddma of the laser machining head 1 in the same manner as the descending distance Dd1 of the mode B1 with respect to the punching distance Lhma (S25).
That is, since the time Tma for moving the holed distance Lhma at the scanning speed V1 is Tma = Lhma / V1, the descending distance Ddma of the laser processing head 1 at the holed distance Lhma can be obtained by Ddma = V4 × Tma. it can.

The copying controller 74 determines that the calculated descending distance Ddma is
Gm> Ga-Ddma (Formula 3)
It is determined whether or not the condition is satisfied (S26).

When it is determined in step (S26) that (Equation 3) is not satisfied (No), the copying control unit 74 moves the laser processing head 1 for both holes Wh1 and Wh2 without copying. It is determined that it is allowed to pass only (S27).
This step is also illustrated in FIG. That is, in FIG. 3, in mode B2, it is determined whether (Equation 3) is satisfied (S5-1). If not satisfied, the process proceeds to (S2) and mode A which is a copying movement is executed.
If the condition is satisfied, a retraction movement or a movement including a retraction movement described below is executed (S5-2).
Steps (S5-1) and (S5-2) in FIG. 3 correspond to steps (S26) and steps (S29) to (S31) in FIG. 9, respectively.

In the case of reaching this step (S27), if Lh3> Lh2 in FIG. 8, Lhma = Lh3. As shown in FIG. 10A, Ddma = Dd3 and Dd3> Dd2. As a result, the laser processing head 1 can pass through the scanning movement as indicated by the locus Dc1 in FIG. 10A for both the holes Wh2 and Wh3.
The locus Dc1 is a locus of the tip 1np of the nozzle 1n in the laser processing head 1.

If (Equation 3) is not satisfied, the laser machining head 1 is moved in a scanning manner in which the control is performed by following the hole Whmi having the smallest hole distance Lhmi as well as the hole Whmi having the largest hole distance Lhma. The position of the tip 1np of the nozzle 1n does not become less than the approach limit gap Gm.
Accordingly, for the hole Whmi, which is the hole engagement distance Lhmi, the laser machining head 1 is moved only by copying without determining whether the tip 1np descending distance of the nozzle 1n is lowered to be less than the approach limit gap Gm. Can pass through the holes Wh2 and Wh3 and move to the piercing position Ep.

When it is determined in step (S26) that (Equation 3) is satisfied (Yes), the descent distance Ddmi is obtained for the hole-engaging distance Lhmi (S28).
That is, since the time Tmi for moving the hole distance Lhmi at the scanning speed V1 is Tmi = Lhmi / V1, the descent distance Ddmi of the laser processing head at the hole distance Lhmi can be obtained by Ddmi = V4 × Tmi. .

The copying controller 74 determines that the calculated descending distance Ddmi is
Gm> Ga-Ddmi (Formula 4)
It is determined whether or not the condition is satisfied (S29).

  When it is determined in step (S29) that (Expression 4) is not satisfied (No), the laser processing head 1 is allowed to pass through one hole Whma (here, hole Wh2) by retraction and the other hole Whmi (here) Then, it is determined that the hole Wh3) is allowed to pass through the copying movement (S30).

In the case of reaching this step (S30), for example, in FIG. 8, if Lh2> Lh3, Lhma = Lh2, Lhmi = Lh3. As shown in FIG. 10B, Dd2> Dk and Dd3 <Dk.
Accordingly, the scanning control unit 74 moves the laser machining head 1 along a locus Dc2 that allows the hole Wh2 to pass scanning by the retraction movement in the retreating gap Gt after releasing the scanning control, and the hole Wh3 passes by the copying movement by the copying control. . The locus Dc2 is the locus of the tip 1np of the nozzle 1n in this case.

  If it is determined in step (S29) that (Equation 4) is satisfied (Yes), it is determined that the laser processing head 1 is allowed to pass through the retreat movement together with the hole Whma and the hole Whmi (hole Wh2 and hole Wh3) (S31). .

In the case of reaching this step (S31), for example, if Lh2> Lh3 in FIG. 8, Lhma = Lh2, Lhmi = Lh3. As shown in FIG. 10C, Dd2> Dk and Dd3> Dk.
Accordingly, the laser processing head 1 is moved along the locus Dc3 through which both the hole Wh2 and the hole Wh3 pass through the retreat movement. The locus Dc3 is a locus of the tip 1np of the nozzle 1n in this case.

  According to the procedure of the above mode B2, the determination of the moving method for passing the two holes may be performed only once in step (S26). As a result, the processing load of the copying control unit 74 is reduced, the movement of the laser processing head 1 from the cutting end position Ee to the piercing processing position Ep is accelerated, and the reliability of the copying movement is improved.

(Mode B3)
Next, a case where there are three or more holes (n: an integer of 3 or more) on the movement projection path Rb in the workpiece W will be described with reference to FIGS.
The n holes are holes Wk1 to Wkn.

  In mode B3, when there are three or more holes on the moving projection path Rb of the laser processing head 1, the scanning control unit 74 obtains the hole distance of each hole, and the maximum hole distance and the minimum hole distance are obtained. Based on either one of the distances or both, it is determined whether to pass each corresponding hole by copying movement or by retreating movement. On the other hand, it is a mode in which determination is not performed for other hole contact distances, and a hole corresponding to the other hole contact distance is determined and executed, such as passing through movement based on the determined movement.

FIG. 11 is a top view of the workpiece W as viewed from above, similarly to FIGS. 4 and 7. In FIG. 11, the movement projection path Rc of the laser processing head 1 from the cutting end position Ee of the cutting processing line Ca to the piercing processing position Ep for the next cutting processing is indicated by a one-dot chain line arrow as a linear path. ing.
FIG. 12 is a table for explaining a procedure for determining whether the laser processing head 1 is to be copied or retracted when passing through the holes Wk1 to Wkn.
FIG. 13 is a flowchart for explaining the determination procedure shown in the table of FIG.

  Here, in FIG. 11, the separation distances Ldk12, Ldk23 (not shown)... Ldk (n−1) n (not shown) between adjacent holes are equal to or greater than the return distance Lf as described above. .

  The movement projection path Rc is set linearly from the cutting end position Ee to the piercing position Ep, and in this example, it crosses three or more n holes Wk1 to Wkn already formed in the workpiece W. Yes.

  After the determination in step (S3) (FIG. 3), the copying control unit 74 reads a plurality of holes from the machining program PG and the workpiece information J2 stored in the storage unit 73 before the machining of the cutting machining line Ca is completed. The punching distances Lk1 to Lkn of Wk1 to Wkn are acquired (FIG. 13: S31).

  For example, as shown in FIG. 11, the hole hooking distance Lk1 is a horizontal distance between a hooking start position Ek1 and an end position Ek2 in the hole Wk1. The hole hooking distance Lk2 is a horizontal distance between the hook start position Ek3 and the end position Ek4 in the hole Wk2. The hole hooking distance Lkn is a horizontal distance between the hook start position Ek (2n−1) and the end position Ek2n in the hole Wkn.

  The scanning gap Ga, the cutting gap Gc, the approach limit gap Gm, the piercing gap, and the respective speeds are the same as those in the modes B1 and B2.

The copying control unit 74 obtains the maximum punching distance Lkma that is the maximum value and the minimum punching distance Lkmi that is the minimum value from the acquired punching distances Lk1 to Lkn (S32).
Hereinafter, of the holes Wk1 to Wkn, the hole having the maximum hole covering distance Lkma is referred to as a hole Wkma, and the hole having the minimum hole covering distance Lkmi is referred to as a hole Wkmi.

The scanning control unit 74 determines the lowering distance Dma of the laser processing head 1 corresponding to the maximum hole covering distance Lkma when the hole Wkma is passed through the scanning movement in the same manner as the lowering distance Dd1 of the mode B1 ( S33).
That is, since the time Tma for moving the maximum punching distance Lkma at the scanning speed V1 is Tma = Lkma / V1, the descending distance Ddma of the laser machining head 1 at the maximum punching distance Lkma is obtained by Ddma = V4 × Tma be able to.

  The copying control unit 74 determines whether or not the calculated descending distance Ddma satisfies the above (Equation 3) (S34).

When it is determined that (Equation 3) is not satisfied (No), the copying control unit 74 determines that the laser processing head 1 is allowed to pass through only the copying movement that does not involve retraction movement for all the holes Wk1 to Wkn. (S35).
The determination pattern from step (S34) to step (S35) is referred to as determination pattern P1.
This step is also illustrated in FIG. That is, in FIG. 3, in mode B3, it is determined whether (Equation 3) is satisfied (S6-1), and if not satisfied, the process proceeds to (S2) to execute mode A which is a copying movement.
If the condition is satisfied, a retraction movement or a movement including a retraction movement described below is executed (S6-2).
Steps (S6-1) and (S6-2) in FIG. 3 correspond to steps (S34) and steps (S36) to (S39) in FIG. 13, respectively.

  As shown in FIG. 12, in the determination pattern P1, when the copying control unit 74 determines in step (S34) that the maximum punching distance Lkma can be passed by copying movement (◯), in step (S35). This is a pattern for determining that all holes can be passed by copying movement (◯).

When it is determined that (Equation 3) is satisfied (Yes), the copying control unit 74 obtains the descending distance Ddmi of the laser processing head 1 with respect to the minimum punching distance Lkmi (S36).
That is, since the time Tmi for moving the minimum punching distance Lkmi at the scanning speed V1 is Tmi = Lkmi / V1, the descending distance Ddmi of the laser processing head 1 at the minimum punching distance Lkmi is obtained by Ddmi = V4 × Tmi. be able to.

  The copying control unit 74 determines whether or not the calculated descending distance Ddmi satisfies the above (Equation 4) (S37).

When the copying control unit 74 determines that (Equation 4) is not satisfied, the hole Wkmi corresponding to the minimum hole contact distance Lkmi passes through the copying movement, and the other holes are released by the copying movement after releasing the copying control. (S38).
The determination pattern from step (S34) through steps (S36) and (S37) to step (S38) is defined as determination pattern P2.

In the determination pattern P2, as shown in FIG. 12, the copying control unit 74 performs the first determination that the copying through the copying movement is impossible (Δ) with respect to the maximum punching distance Lkma that becomes Yes in step (S34). In addition, in step (S37), the determination pattern is obtained when the second determination is made that it is possible to pass (No) in the scanning movement that is No for the minimum punching distance Lkmi.
In this case, the scanning control unit 74 allows the hole Wkmi corresponding to the minimum hole contact distance Lkmi to pass through the copy movement, and from the hole corresponding to the second smallest hole contact distance Lkmi2 which is the remaining hole to the maximum hole contact distance Lkma. It is determined that the hole Wkma corresponding to is canceled by the copying control and is allowed to pass by retraction.

When it is determined in step (S37) that (Equation 4) is satisfied, the copying control unit 74 determines that all the holes Wk1 to Wkn are allowed to pass through the retreat operation (S39).
The determination pattern of step (S37) and step (S39) is referred to as determination pattern P3.

  In the determination pattern P3, as shown in FIG. 12, the copying control unit 74 performs the first determination that the copying in the copying movement is impossible (Δ) for the maximum hole distance Lkma that becomes Yes in step (S34). In addition, in step (S37), the determination pattern is obtained when the second determination is made that the minimum punching distance Lkmi cannot be passed by copying movement (Δ). In this case, the scanning control unit 74 determines that the scanning control is canceled and all the holes Wk1 to Wkn are allowed to pass through the retreat movement.

According to the procedure of the above mode B3, the determination of the moving method for passing three or more holes is performed once in step (S34) or in steps (S34) and (S37) regardless of the number of holes. It only takes two times.
As a result, the processing load of the copying control unit 74 is reduced, the movement of the laser processing head 1 from the cutting end position Ee to the piercing processing position Ep is accelerated, and the reliability of the copying movement is improved.

Next, the case where the separation distance Ld between two adjacent holes is smaller than the return distance Lf will be described with reference to FIG.
The copying control unit 74 obtains the separation distance Ld as well as the punching distance in step (S21) in mode B2 and step (S31) in mode B3.
Then, the copying control unit 74 determines and determines the two holes that give the separation distance Ld as two holes as they are according to the procedure shown in FIG. 14 based on the obtained separation distance Ld, or regards it as one hole. Determine whether to determine.

For example, for the hole WA and the hole WB that are adjacent on an arbitrary movement projection path, the scanning control unit 74 obtains a separation distance LdAB between the holes (S41).
Next, it is determined whether or not the obtained separation distance LdAB is equal to or greater than the return distance Lf (S42).

When it is determined as Yes (Yes), the hole WA and the hole WB are set as two holes as they are (S43), and the subsequent determination of the mode B2 and the mode B3 is performed.
If it is determined as No (No), the hole contact distance LkA of the hole WA, the separation distance LdAB, and the hole contact distance LkB of the hole WB are added to calculate the estimated hole contact distance LkAB (S44). .
The copying control unit 74 sets the hole WA and the hole WB as one look-up hole WAB having the look-and-hang distance LkAB (S45), and performs subsequent determination of the mode B2 and the mode B3.
According to this presumed hole setting procedure, it is possible to determine the moving method by regarding the plurality of holes as the number of holes smaller than the actual number.
As a result, the number of determination processes can be reduced, the processing load of the scanning control unit 74 is reduced, the movement of the laser processing head 1 from the cutting end position Ee to the piercing processing position Ep is accelerated, and copying is performed. The certainty of movement is improved.

  The embodiment of the present invention is not limited to the above-described configuration and procedure, and may be modified as long as it does not depart from the gist of the present invention.

FIG. 15 is a top view of the workpiece W for explaining a modified example of the procedure for determining the moving method of the laser machining head 1, and shows the movement path Rd1 from the cutting end position Ee to the piercing machining position Ep to the workpiece W. A moving projection path Rd that is a projection is described.
The moving projection path Rd crosses the hole WJ1 and the hole WJ2.

  As shown in FIG. 15, the movement projection path Rd includes a horizontal distance Lj3 between the cutting end position Ee and the position Ej1 at which the hole WJ1 starts to be engaged, a hole engagement distance Lj1 of the hole WJ1, and a hole WJ1 and a hole WJ2. Are separated into sections of a separation distance Ldj1 between the two, a hole hooking distance Lj2 of the hole WJ2, and a horizontal distance Lj4 between the hooking end position Ej4 of the hole WJ2 and the piercing position Ep.

The speed in the horizontal direction under the scanning control of the laser processing head 1 is the above-described scanning speed V1.
On the other hand, the descending speed V4 and the ascending speed V3 under the scanning control of the laser processing head 1 are, for example, the speeds represented by the following (Expression 5) and (Expression 6), respectively.
V4 = C1 × (C2-Ga) (Formula 5)
V3 = C1 × (Ga−C3) (Formula 6)
C1 is a predetermined gain constant, C2 is a predetermined upper limit value of the gap G, C3 is a predetermined lower limit value of the gap G, and Ga is the scanning gap Ga described above. It is.

  Further, the scanning control unit 74 stops moving upward and moves horizontally when the upper limit value C2 of the gap G is reached during oblique movement during scanning movement under scanning control of the laser processing head 1. Further, when the lower limit value C3 of the gap G is reached by the oblique lowering during the copying movement, the lowering is stopped and the horizontal movement is controlled.

Under these conditions, the scanning control unit 74 uses the scanning speed V1, the descending speed V4, the ascending speed V3, the machining program PG, and the workpiece information J2, and the position of the tip 1np of the nozzle 1n in each section. Is obtained by calculation or the like.
When the gap G of the obtained trajectory is equal to or larger than the approach limit gap Gm in all sections, the laser processing head 1 is moved along.
Further, when the distance is less than the approach limit gap Gm, the copying control is canceled at the position where the distance is less than the approach limit gap Gm, the process shifts to the evacuation operation, is moved horizontally to the piercing position, and then the copying control state is set to the piercing gap Gp. Lower.

According to this method, in the scanning movement of the laser processing head 1, since the ascending / descending in the portion where the workpiece W other than the hole exists is taken into consideration, the trajectory can be predicted with high accuracy. Therefore, the laser processing head 1 can be moved to the piercing position by scanning control with a smaller approach limit gap Gm.
This is effective when the scanning gap Ga and the piercing gap Gp are very small with respect to the retraction gap Gt, and the movement time is shortened compared to the case where the retraction movement is included.

In mode B3, the copying control unit 74 may control as follows.
That is, if it is determined that the descending distance Ddmi corresponding to the minimum punching distance Lkmi is No in step (S37), the determination of step (S37) is similarly performed for the descending distance corresponding to the second smallest punching distance.
If this determination is No, the determination of step (S37) is performed in order from the smallest, such as the descending distance corresponding to the third smallest hole distance.
Then, when the determination of step (S37) becomes Yes for the q-th hole engagement distance from the smallest, holes Wk1 to Wk (q-1), which are the first to q-1th holes, are passed by copying movement. And the holes Wkq to Wkn, which are the q-th to n-th holes, are allowed to pass through the retreat movement.

The control device 71 is not limited to the one provided in the laser processing device 51, and may be provided outside.
The copying control unit 74 is not limited to the one provided in the control device 71, and may be provided outside.

Although the laser processing apparatus 51 according to the embodiment has been described with the workpiece W positioned horizontally and the workpiece W being irradiated with laser light from vertically above the laser processing head, the present invention is not limited to this. Any laser beam that irradiates the workpiece W in a direction orthogonal to the workpiece W may be used.
In this case, the configuration of the laser processing apparatus 51 is such that the horizontal direction is replaced with the extending direction of the workpiece W and the vertical direction is replaced with the orthogonal direction with respect to the workpiece W.

The target of the hole engagement distances Lh <b> 1 to Lh <b> 3 is not limited to the hole, but as described above, is an opening including a cut portion and a deep recess.
Other, the perforated distances Lk1 to Lkn, LkA, LkB, Lhma, Lhmi, the estimated perforated distance LkAB, the maximum perforated distance Lkma, the maximum perforated distance, Lkmi, and the minimum perforated distance Lkmi, Similarly, not only the hole but also an opening including a cut portion and a deep recess is targeted.

DESCRIPTION OF SYMBOLS 1 Laser processing head, 1n nozzle, 1np tip part 2 Distance sensor, 3 Laser light source, 4 Assist gas source 51 Laser processing apparatus, 61 Laser processing machine, 71 Control apparatus 72 CPU (central processing unit), 73 Memory | storage part, 74 Copy Control part Ca Cutting process line Dc1, Dc2 Trajectory Dd, Dd1 to Dd3, Ddma, Ddmi Lowering distance Dk Permissible lowering distance Ee Cutting end position, Eep Ascent start position Eh1 to Eh6, Ek1 to Ek2n, Ej1, Ej4 Position Ep Piercing position G gap Ga scanning gap, Gc cutting gap, Gm access limit gap Gp piercing gap, Gt retraction gap, G1 distance J1 gap information, J2 work information KD head drive unit Ld, Ld23, Ldk12, LdAB, Ldj1 separation distance Lf return distance, Lh1 ~ Lh3 Hole distance Lk1 to Lkn, LkA, LkB, Lhma, Lhmi Hole distance LkAB Look-up hole distance Lkma Maximum hole distance, Lkmi Minimum hole distance, Lp Horizontal distance LZ Laser light M1 to M3 motor, M1e to M3e encoder PG machining program, P1 to P3 determination patterns Ra, Rd1 travel path, Rb, Rc, Rd travel projection path Rt retreat path T1, Tma, Tmi time Vu speed, V1 scanning speed, V2 speed component, V3 rise speed V4 fall Speed, V5 Rapid feed speed W Workpiece, WAB lookout hole, Ws Upper surface (surface)
WA, WB, Wh1, Wh2, Wh3, Whma, Whmi, Wk1-Wkn, WA, WB, WJ1, WJ2

Claims (6)

A laser processing head for irradiating a workpiece with laser light;
A head drive unit that moves the laser processing head in three axial directions of XYZ;
A scanning control unit that controls the head driving unit to move the laser machining head in accordance with the workpiece;
With
The copying control unit
When a movement projection path, which is a projection of the predetermined movement path of the laser processing head onto the workpiece, crosses a plurality of openings, from among the punching distances that are the distances that the movement projection path is applied to each opening. Finding the maximum perforation distance, determining whether the laser processing head can pass through the opening that gives the maximum perforation distance, and if it is determined that it can pass, all of the plurality of openings Laser processing device that controls to pass through by copying movement. The copying control unit
The minimum hole contact distance is obtained from the hole contact distances, and it is determined whether or not the laser processing head can pass through the scanning movement through the opening that gives the minimum hole contact distance. 2. The laser processing apparatus according to claim 1, wherein the laser processing head is caused to pass through a retreating movement in which the plurality of openings are moved at positions farther from the workpiece than the scanning movement. The copying control unit
The first opening and the second opening that are adjacent to each other among the plurality of holes are separated by one when the separation distance between the first opening and the second opening is smaller than a predetermined distance. The laser processing apparatus according to claim 1, wherein the laser processing apparatus is regarded as an opening and determines whether or not the copying movement is possible. A scanning control method for moving a laser processing head that irradiates a workpiece with a laser beam in accordance with the workpiece,
When a movement projection path that is a projection of the predetermined movement path of the laser processing head onto the workpiece crosses a plurality of openings,
Obtaining a maximum hole distance from a hole distance that is a distance that the moving projection path is applied to each opening; and
Determining whether or not the laser processing head can pass by scanning movement through the opening that gives the maximum punching distance;
A step of determining that all of the plurality of openings are allowed to pass by copying movement when it is determined that they can pass;
A scanning control method comprising: Obtaining a minimum punching distance from the punching distance;
Determining whether or not the laser processing head can pass by scanning movement through the opening that gives the minimum punching distance;
Determining that the laser processing head is allowed to pass through a retreating movement that moves the laser processing head at a position farther from the workpiece than the copying movement when it is determined that the scanning movement is impossible. ,
The scanning control method according to claim 4, further comprising: Determining whether a separation distance between the first opening and the second opening adjacent to each other among the plurality of openings is smaller than a predetermined distance;
5. The apparatus according to claim 4, wherein when it is determined that the second opening is small, the first opening and the second opening are regarded as one opening, and it is determined whether or not the copying movement is possible. Alternatively, the copying control method according to claim 5.

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