DE102019209221B4 - Process for fragmenting cutting of a plate-shaped workpiece - Google Patents

Abstract

Method for cutting a panel-shaped workpiece (10) by means of a processing beam, comprising: cutting at least one separating cut (11) for dividing the panel-shaped workpiece (10), characterized in that the cutting of the separating cut (11) involves the cutting of at least one preliminary cut (12 , 42) and the following cutting at least one includes at least one cut (11) completing the cut (18, 20, 22, 24, 38), whereby the pre -cut (12, 42) with a crossing point (14, 50) with a further pre -cut (16 ) of a further separating cut (13) or with a good part contour (35), and wherein the preliminary cut (12, 42) has an end section (26, 28, 46) on which the completing cut (18, 20, 22, 24, 38) and which the completing cut (18, 20, 22, 24, 38) crosses.

Description

Background of the Invention

The invention relates to a method for cutting a plate-shaped workpiece, in particular a remaining plate-shaped workpiece, by means of a processing beam, in particular by means of a laser beam, comprising: cutting at least one separating cut for dividing the plate-shaped workpiece.

When laser cutting plate-shaped workpieces, a residual grid of the plate-shaped workpiece remains after the good parts have been cut free, also known as the residual workpiece. Out of DE 10 2010 042 561 B3 , JP 2002 337 040 A or JPH05127721 it is known to divide the remaining residual lattice into smaller residual lattice sections with the laser beam.

Out of U.S. 8,716,625 B2 it is known to use the laser beam to cut waste parts (slugs) from plate-shaped workpieces into smaller pieces that can be better discharged from the process. Intersecting lines and then a spiral contour are cut into the waste part.

When the skeleton is divided into smaller sections and the separating cut is complete, i.e. it extends to the outer edge of the panel-shaped workpiece or to the workpiece parts that have been cut free (good parts), at least one residual skeleton section becomes free, i.e. it is no longer connected to the panel-shaped workpiece or the workpiece connected to the workpiece panel.

If scrap skeleton sections become free, it can happen that the sections that become free move against each other. Such a displacement can arise, for example, as a result of the cutting gas pressure acting during cutting. This can lead to a height offset of the sections along the separating cut, which has a negative effect if two or more separating cuts for dividing the residual skeleton intersect: For example, when cutting a second separating cut at the crossing point between the first separating cut and the second separating cut, the workpiece parts are in opposite directions offset in height, the cutting head, usually the cutting nozzle, can collide with a section of the workpiece, which can lead to damage to the cutting head and, in the worst case, to a machine downtime.

A similar problem can occur if the separating cut for dividing the scrap skeleton is adjacent to a good part that has already been cut free. If the good part is tilted during free cutting, the cutting head can collide with the tilted good part at the crossing point between the separating cut and the contour of the good part.

In the JP 2015-116 604 A describes a laser cut-off processing method that enables workpiece parts to be cut and separated without scrap parts colliding with a laser processing head, even if the scrap parts tend to partially overhang the top of a workpiece. The laser cut-off processing is performed in a direction away from the scrap when the scrap is cut and separated from the workpiece.

object of the invention

The object of the present invention is to improve process reliability when producing separating cuts for dividing a plate-shaped workpiece.

Description of the invention

This object is achieved by a method of the type mentioned at the outset, in which the cutting of the separating cut comprises the cutting of at least one preliminary cut and the subsequent cutting of at least one cut that completes the separating cut. The pre-cut comprises a crossing point with a further pre-cut of a further separating cut or with a good part contour and the pre-cut has an end section on which the completing cut meets and which the completing cut intersects.

According to the invention, it is proposed to subdivide the separating cut(s) into sections during dividing cutting and to first cut a crossing point of crossing separating cuts or a crossing point of a separating cut with a good part contour as preliminary cuts, i.e. before all further cuts. In this way, the area at risk of collision is cut first, before the separating cut is completed by at least one subsequent cut and the plate-shaped (residual) workpiece is divided along the separating cut. Before the separating cutting, there is not yet a risk of a collision at the crossing point, since there is no height offset.

In the case of two intersecting separating cuts, the crossing point, as the area at risk of collision, is the first to be cut, usually in the form of a cross or of intersecting preliminary cuts.

In one variant, when cutting the pre-cut, the good part contour and the preferably linear pre-cut starting from the crossing point are cut together, with the end section being formed on the pre-cut. In the event that the scrap skeleton separating cut borders on a good part contour, the good part contour is extended by the pre-cut. In this case, at the beginning or at the end of the cutting of the good part contour, the pre-cut is cut, the end section of which is spaced far enough from the crossing point with the good part contour that the cutting head cannot collide with a possibly tilted good part.

The separating cuts are only completed in subsequent process steps so that the remaining skeleton sections can be freed. As a rule, this is done in such a way that a respective completing cut runs only as far as an end section of the preliminary cut. In this way it can be ensured that there is a sufficient distance to the crossing point to avoid a collision with the cutting head. Further cuts can be made between the preliminary cuts and the completing cuts for dividing the (remaining) workpiece in order to cut free good parts or waste parts (slugs) from the workpiece. As a rule, the preliminary cuts (with the exception of the final contours, see below) and the completing cuts are linear, but this is not absolutely necessary.

To ensure that the finishing cut meets the end portion of the precut, the finishing cut meets or crosses the end portion of the precut at an angle.

In a variant, the end section of the pre-cut forms an end contour which, at least in sections, runs transversely (i.e. not parallel, in particular perpendicularly) to the direction of the pre-cut. The final contour thus has at least one section that deviates from the rest of the shape, which is usually rectilinear, of the precut. Typically, the completing cut crosses the final contour or the section running transversely to the direction of the pre-cut, so that the completing cut reliably meets the pre-cut. In this way it can be ensured that the separating cut is actually completed even in the event of heat distortion or displacement of the workpiece or the remaining skeleton sections that are produced and the remaining skeleton section is cut free as desired.

In a further development, the end section of the further pre-cut has a further end contour which, at least in sections, runs transversely (i.e. not parallel, in particular perpendicularly) to the direction of the further pre-cut. Another completing cut, which completes another separating cut, crosses the further end contour or the transverse section of the further end contour. In this way it can be ensured that the further separating cut, which includes the further preliminary cut and the further completing cut, is actually completed and the remaining skeleton section is cut free, even in the event of heat distortion or displacement of the workpiece or the resulting residual skeleton parts.

In a further development, the end contour and/or the further end contour has/have a section of a polygon, preferably a triangle or a square, or an arc of a circle. All of these shapes have at least one section that runs transversely to the pre-cut and can be hit by the cut that completes the separating cut.

Preferably, the end contour and/or the further end contour is/are cut as a circular arc, particularly preferably the length of the circular arc is between a semicircle and a three-quarter circle, in particular the circular arc forms a three-quarter circle. Since round contours can be cut at higher speeds than square contours, the maximum process speed can be achieved in this way. If the final contour is designed as a three-quarter circle, it also has the maximum possible extent transverse to the pre-cut, which leads to the highest level of process reliability when completing the separating cut.

The circular arc of the end contour preferably has a diameter of at least 3 mm. This enables the final contour to be cut at the highest possible speed. As the thickness of the plate-shaped workpiece increases, the diameter of the final contour is preferably selected to be correspondingly larger.

In one variant, the end contour and/or the further end contour starts with a rounding from a linear section of the precut and/or the further precut. The rounded transition between the preliminary cut and the final contour is preferably in the form of an arc of a circle in order to be able to cut at the highest possible speed. The diameter or radius of the rounding is preferably at least half as large as the diameter or radius of the circular arc of the final contour. The diameter or radius of the rounding particularly preferably corresponds to the diameter or radius of the circular arc.

Further advantages of the invention result from the description and the drawing. as well According to the invention, the features mentioned above and those detailed below can be used individually or collectively in any combination. The embodiments shown and described are not to be understood as an exhaustive list, but rather have an exemplary character for the description of the invention.

character list

• 1 : shows an example of two separating cuts with a crossing point between two crossing pre-cuts,
• 2 : shows an example of two separating cuts, each of which has an intersection point with a good part contour,
• 3 : shows, by way of example, different shapes of a final contour of a pre-cut, and
• 4 : shows an example of a fillet at the transition between a linear section and a final contour of a rough cut.

In 1 is a schematic representation of a plate-shaped workpiece 10 (residual skeleton), which is divided into four sections by a separating cut 11 (hereinafter: first separating cut 11) and a further separating cut 13 (hereinafter: second separating cut 13), i.e. the separating cuts 11, 13 extend to to the outer edge of the plate-shaped workpiece 10, which is not illustrated.

As in 1 can be seen, the two mutually perpendicular separating cuts 11 and 13 intersect at an intersection point 14. In order to prevent a cutting head (not shown) from colliding with upstanding, freely separated sections of the workpiece 10 during separating cutting in the area of the intersection point 14, the divided into sections: The first separating cut 11 consists of a first preliminary cut 12 and two completing cuts 18 and 20. The second separating cut 13 consists of a second preliminary cut 16 and two further completing cuts 22 and 24.

• In einem ersten Verfahrensschritt wird der erste Vorschnitt 12 geschnitten. Der erste Vorschnitt 12 verläuft geradlinig, wobei an den Endabschnitten des zweiten Vorschnitts 15 jeweils eine Endkontur 26, 28 gebildet ist. Die Endkonturen 26, 28 haben die Form von Dreiviertelkreisen und verlaufen abschnittsweise quer zur (horizontalen) Richtung des ersten Vorschnitts 12.

When cutting the workpiece 10 separately, the procedure is as follows:

• In a first method step, the first pre-cut 12 is cut. The first pre-cut 12 runs in a straight line, with an end contour 26, 28 being formed on the end sections of the second pre-cut 15 in each case. The end contours 26, 28 are in the form of three-quarter circles and in sections run transversely to the (horizontal) direction of the first pre-cut 12.

In a subsequent method step, the second pre-cut 16, which likewise runs in a straight line except for the two end contours 30, 32 forming a three-quarter circle, is cut. When the second pre-cut 16 is cut, it crosses the first pre-cut 12 at the crossing point 14. Since the two separating cuts 11, 13 are only completed in subsequent process steps with the aid of the completing cuts 18, 20, 22 and 24 (see below), there is no danger that the cutting head collides with a separated or tilted section of the workpiece 10 when crossing the crossing point 14 .

The first separating cut 11 is completed by the two completing, linear cuts 18 and 20. The first completing cut 18 meets the first preliminary cut 12 in the area of the first end contour 28 and intersects the first three-quarter circular end contour 28. The second completing cut 20 meets of the second end contour 26 on the first pre-cut 12 and thereby intersects the second, three-quarter circular end contour 26.

Accordingly, the second separating cut 13 is completed by the further completing linear cuts 22 and 24: The first further completing cut 22 intersects the first further end contour 32 of the further preliminary cut 16 and the second further completing cut 24 intersects the second further end contour 30 of the second Precut 16.

The order in which the completing cuts 18, 20, 22, 24 are cut is fundamentally arbitrary. It is essential that the area of the crossing point 14 is cut first before the separating cuts 11 and 13 are completed. The length of the preliminary cuts 12, 16 and thus the distance between the completing cuts 18, 20, 22, 24 and the crossing point 14 is selected to be large enough that when the separating cuts 11, 13 are completed there is no risk of the cutting head colliding. It is understood that the in 1 The crossing point 14 shown and the points shown at the ends of the other contours are only used to clarify the illustration, but no punctiform contours are cut during separating cutting.

In 2 a plate-shaped (residual) workpiece 10 with a rectangular good part 34 is shown schematically. When the good part 34 is cut, a linear preliminary cut 42 is cut, which crosses the rectangular good part contour 35 at a crossing point 50 . The linear pre-cut 42 is cut together with the good part contour 35 and can be cut at the beginning or at the end of the cutting of the first good part contour 35 . When the good part 34 is cut, the precut 42 is cut at the same time with its associated end contour 46, which also has the shape of a three-quarter circle.

Also with the in 2 Workpiece 10 shown is completed in the separating cutting of the first preliminary cut 42 by a completing cut 38 to a first separating cut 39. The completing, linear cut 38 crosses or intersects the precut 42 at the end contour 46, as in connection with FIG 1 is described.

The point at which the completing cut 38 intersects the precut 42 should be at a sufficient distance from the good part contour 35 or from the crossing point 50 . In this way it can be ensured that the good part 34 cut free, which may be tilted in relation to the (residual) workpiece 10, does not collide with the cutting head.

In the example shown, the completing cut 38 has an end section 37 on which a further completing cut 36 meets, so that the completing cut 38 simultaneously forms a further preliminary cut of the first separating cut 39 . A second separating cut 13 crosses the further preliminary cut 38 of the first separating cut 39 at a further crossing point 52. The second separating cut 13 consists as in FIG 1 from a second pre-cut 16 and two further completing cuts 22, 24. The second pre-cut 16 has two end contours 30, 32 which form a three-quarter circle. In addition, the good part contour 35 can be connected to a further pre-cut (not shown). In this way, the remainder of the workpiece 10 can be divided into several smaller workpiece parts.

In 3 Examples of four different geometries of end contours 56, 58, 60, 62 of a respective pre-cut 64 are shown. In the 3 The two end contours 56 and 58 shown on the left are examples of sections of a polygon: the end contour 56 shown at the top left is a section of a triangle and the end contour 58 shown at the bottom left is a section of a rectangle. The end contour 60 shown at the top right is designed in the shape of a semicircle. The end contour 62 shown at the bottom right is designed in the shape of a three-quarter circle. Both end contours 60, 62 have a diameter D on. The end contour 62 shown at the bottom right in the form of a three-quarter circle represents the preferred end contour, since a higher process speed can be achieved with round contours and a three-quarter circle also has a large transverse extension to the remaining pre-cut 64 and thus a high level of process reliability can be achieved when completing a respective separating cut can.

The diameter D is preferably in 3 circular end contours 60, 62 shown on the right are at least 3 mm. In the case of thicker workpieces 10, the diameter D can optionally be selected to be significantly larger than 3 mm. The size of the diameter D can be adapted to the thickness of the workpiece 10, for example by increasing the diameter D as the workpiece thickness increases.

In 4 1 shows another example of an end contour 62 in the form of a three-quarter circle formed on a precut 64. FIG. The linear section of the preliminary cut 64 merges into the three-quarter circle of the end contour 62 in the form of a rounding 66 . In the example shown, the rounding 66 forms an arc of a circle, more precisely approximately a quarter of a circle. The diameter D' of the rounding 66 is preferably at least half the diameter D of the end contour 62. In the example shown, the diameter D' of the rounding 66 is the same as the diameter D of the three-quarter circle of the end contour 62. As in 4 can also be seen that the arcuate rounding 66 is curved in the opposite direction to the arcuate end contour 62 .

Claims (10)

Method for cutting a panel-shaped workpiece (10) by means of a processing beam, comprising: cutting at least one separating cut (11) for dividing the panel-shaped workpiece (10), characterized in that cutting the separating cut (11) involves cutting at least one preliminary cut (12 , 42) and the following cutting at least one includes at least one cut (11) completing the cut (18, 20, 22, 24, 38), whereby the pre -cut (12, 42) with a crossing point (14, 50) with a further pre -cut (16 ) of a further separating cut (13) or with a good part contour (35), and wherein the preliminary cut (12, 42) has an end section (26, 28, 46) on which the completing cut (18, 20, 22, 24, 38) and which the completing cut (18, 20, 22, 24, 38) crosses. procedure after claim 1 , characterized in that when cutting the pre-cut (42), the good part contour (35) and the pre-cut (42) starting from the crossing point (50) and on which the end section (46) is formed are cut. procedure after claim 1 or 2 , characterized in that the end section of the pre-cut (12, 42) forms an end contour (26, 28, 46) which, at least in sections, runs transversely to the direction of the pre-cut (12, 42). Method according to one of the preceding claims, characterized in that an end section of the further pre-cut (16) forms a further end contour (30, 32) which runs at least in sections transversely to the direction of the further pre-cut (16). procedure after claim 3 or 4 , characterized in that the completing cut (18, 20, 38) of the separating cut (11) crosses the end contour (26, 28, 46) and/or a further completing cut (22, 24) of the further separating cut (13) crosses the further Final contour (30, 32) crosses. Procedure according to one of claims 3 until 5 , characterized in that the end contour (26, 28, 46) and/or the further end contour (30, 32) has a section of a polygon or an arc of a circle (60, 62). procedure after claim 6 , characterized in that the length of the circular arc is between a semicircle (60) and a three-quarter circle (62). procedure after claim 6 or 7 , characterized in that the circular arc (60, 62) has a diameter (D) of at least 3 mm. Procedure according to one of claims 3 until 8th , characterized in that the end contour (62) and/or the further end contour (62) with a rounding (66) starts from a linear section of the pre-cut (64) or the further pre-cut. procedure after claim 9 , characterized in that a diameter (D ') of the rounding (66) is at least half as large as the diameter (D) of the circular arc (62).

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