CN112139672B

CN112139672B - Method for the split cutting of plate-shaped workpieces

Info

Publication number: CN112139672B
Application number: CN202010581875.0A
Authority: CN
Inventors: T·罗勒; F·埃西希
Original assignee: Trumpf Werkzeugmaschinen SE and Co KG
Current assignee: Trumpf Werkzeugmaschinen SE and Co KG
Priority date: 2019-06-26
Filing date: 2020-06-23
Publication date: 2022-03-18
Anticipated expiration: 2040-06-23
Also published as: CN112139672A; DE102019209221B4; DE102019209221A1

Abstract

The invention relates to a method for the split cutting of plate-shaped workpieces (10), in particular plate-shaped residual workpieces, by means of a machining beam. The method comprises cutting at least one separating cut (11) for splitting the plate-shaped workpiece (10), wherein the cutting of the separating cut (11) comprises cutting of at least one pre-cut (12) and subsequent cutting of at least one cut (18, 20) that completes the separating cut (11), wherein the pre-cut (12) comprises a further pre-cut (16) with a further separating cut (13) or an intersection (14) with a good piece contour, and wherein the pre-cut (12) has end sections (28, 26) that meet the completing cut (18, 20).

Description

Method for the split cutting of plate-shaped workpieces

Technical Field

The invention relates to a method for cutting plate-shaped workpieces, in particular plate-shaped residual workpieces, by means of a machining beam, in particular by means of laser beam splitting, comprising: at least one separation cut for splitting the plate-like workpiece is cut.

Background

When a plate-shaped workpiece is laser cut, a remaining lattice of the plate-shaped workpiece, also referred to as a remaining workpiece, remains after good pieces are cut out. It is known from DE102010042561B3, JP2002337040A or JPH05127721 to split the remaining grid into smaller remaining grid sub-blocks with a laser beam.

US8,716,625B2, it is known to separate the remnants (slugs) of a plate-shaped workpiece into smaller sub-pieces which can be better removed from the process by means of a laser beam. Here, first, intersecting lines are cut out of the excess material, and then a spiral-shaped contour is cut out.

When the separating slits are completely executed with the remaining grid divided into smaller partial pieces, i.e. up to the outer edge of the plate-shaped workpiece or up to the cut-out workpiece part (good part), at least one remaining grid partial piece becomes free, i.e. it is no longer connected to the plate-shaped workpiece or workpiece plate.

When the remaining grid subblocks become free, it occurs: the sub-blocks that become free move relative to each other. This movement can be produced, for example, by the cutting gas pressure acting during the cutting. This can lead to a staggering of the sub-blocks along the height of the separation cuts, which has a negative effect when two or more separation cuts for dividing the remaining grid intersect each other: if, for example, the workpiece parts are offset in height relative to one another at the point of intersection between the first separating slit and the second separating slit when cutting the second separating slit, a collision of the cutting head, generally of the cutting nozzle, with a sub-block of the workpiece can occur, which can lead to damage of the cutting head and, in the worst case, to a standstill.

Similar problems occur when the separating cuts used to split the remaining grid abut the good pieces that have been cut out. If the good product tips over when it is cut out, a collision of the cutting head with the tipped good product may occur at the intersection between the separation cut and the contour of the good product.

Disclosure of Invention

The invention aims to provide the following steps: the process reliability in producing the separation cut for splitting the plate-like workpiece is improved.

The object is achieved by a method of the type mentioned at the beginning in that the cutting of the separating cut comprises the cutting of at least one precut and the subsequent cutting of at least one cut which completes the separating cut (referred to below as a completing cut). The precut here comprises an intersection with a further precut of a further separating cut or with the contour of the good part and has an end section which meets the completing cut.

According to the invention, the separating cuts during the splitting cut are divided into sections and the intersections of the separating cuts intersecting one another or the intersection of a separating cut with the good product contour are first cut as pre-cuts, i.e. before all further cuts. In this way, the impact-critical region is first cut, only then is the separating cut completed by at least one subsequent cut and the plate-shaped (remaining) workpiece split along the separating cut. There is no risk of collision at the intersection point before the separation cut, since there is no height offset.

In the case of two separate incisions that intersect one another, the intersection point is first cut as a region at risk of collision, and more precisely generally in the form of a cross or a precut that intersects one another.

In one variant, the good product contour is cut together with a preferably linear pre-cut starting from the intersection point when cutting the pre-cut, wherein the end section is formed on the pre-cut.

In the case where the separation cuts of the remaining grid abut on the good product profile, the good product profile is expanded with pre-cuts. In this case, the precut is cut at the beginning or at the end of the cutting of the good product profile, the end sections of which are spaced apart from the intersection of the good product profile by such a distance that no collision of the cutting head with a possibly tipped-over good product occurs.

The separation cut is only completed in a subsequent method step, so that the remaining grid sub-blocks can be freed. This is generally carried out in such a way that the corresponding completion incision extends only over the end section of the precut. In this way it can be ensured that sufficient space to the point of intersection is left to avoid collision with the cutting head. Additional cuts can be made between the precut and the completion cut for splitting (remaining) the workpiece in order to cut good pieces or remnants (slugs) from the workpiece. The precut (except for the end profile, see below) and the completion cut extend generally linearly, but this is not absolutely necessary.

To ensure that: the completion cut meets the end section of the precut, and the completion cut may meet or intersect the end section of the precut at an angle.

In one variant, the end sections of the precut form end profiles which extend at least in sections transversely (i.e. not parallel, in particular perpendicular) to the direction of the precut. The end contour thus has at least one section which differs from the otherwise generally linear shape of the pre-cut. In general, the completion incision intersects the end contour or the section extending transversely to the direction of the pre-incision, so that the completion incision reliably meets the pre-incision. In this way it can be ensured that: in the event of thermal deformation or displacement of the workpiece or of the remaining grid partial block formed, the separating cut can also be practically completed and the remaining grid partial block can be cut out as desired.

In a development, the end section of the further pre-cut has a further end contour which extends at least in sections transversely (i.e. non-parallel, in particular perpendicular) to the direction of the further pre-cut. The further completion incision, which completes the further separation incision, intersects the further end contour or a transversely extending section of the further end contour. In this way it is ensured that: in the event of thermal deformation or displacement of the workpiece or of the remaining grid section formed, the further separating cuts, which comprise further preliminary cuts and further completion cuts, are also actually completed and the remaining grid partial pieces are cut out.

In a further development, the end contour and/or the further end contour has a section of a polygon, preferably a section of a triangle or a quadrilateral, or has a circular arc. All these shapes have at least one section extending transversely to the pre-cut and can meet the cut that completes the separation cut.

Preferably, the end contour and/or the further end contour is cut into a circular arc, particularly preferably the length of the circular arc lies between a semicircle and a triple-quarter circle, in particular the circular arc forms a triple-quarter circle. Since round profiles can be cut at a higher speed than angular profiles, a maximum process speed can be achieved in this way. Furthermore, if the end contour is configured as a three-quarter circle, it has the largest possible extent transversely to the pre-cut, which leads to the highest process reliability in the completion of the separation cut.

Preferably, the arc of the end profile has a diameter of at least 3 mm. This enables: the end profile can be cut at as high a speed as possible. In the case of an increased thickness of the plate-shaped workpiece, the diameter of the end contour is preferably selected to be correspondingly larger.

In one variant, the end contour and/or the further end contour emanates from the linear section of the pre-cut and/or the further pre-cut with rounded corners. The rounded transitions between the precuts and the end profile are preferably embodied in the shape of a circular arc in order to be able to cut at as high a speed as possible. Preferably, the diameter and radius of the rounded portion are at least half as large as the diameter and radius of the circular arc of the end profile. Particularly preferably, the diameter and the radius of the rounded portion correspond to the diameter and the radius of the circular arc.

Drawings

Further advantages of the invention result from the description and the drawings. The features mentioned above and those yet to be mentioned below can likewise be used in accordance with the invention on their own or in any combination in the case of a plurality of features. The embodiments shown and described are not to be understood as exhaustive enumeration but rather have exemplary character for the interpretation of the present invention.

The figures show:

FIG. 1: the intersection between two separation cuts and two intersecting pre-cuts is shown schematically,

FIG. 2: two separate cuts are shown by way of example, each having an intersection with the contour of the good piece,

FIG. 3: different shapes of end profiles exemplarily showing pre-cuts, an

FIG. 4: one example of a rounded corner at the transition between the linear section of the pre-cut and the end profile is shown.

Detailed Description

Fig. 1 schematically shows a plate-shaped workpiece 10 (residual grid) which is split into four partial pieces by a separating kerf 11 (hereinafter referred to as a first separating kerf 11) and a further separating kerf 13 (hereinafter referred to as a second separating kerf 13), i.e. the

separating kerfs

11, 13 extend as far as an outer edge, not shown, of the plate-shaped workpiece 10.

As can be seen in fig. 1, the two

separating cuts

11 and 13, which run perpendicular to one another, intersect at an intersection point 14. In order to avoid collision of the not illustrated cutting head with the cut-out upright sub-block of the workpiece 10 during the separating cut in the region of the intersection point 14, the two

separating cuts

11, 13 are divided into sections: the first separation cut 11 comprises a first precut 12 and two

completion cuts

18 and 20. The second separation cut 13 comprises a second precut 16 and two

further completion cuts

22 and 24.

In this case, the following is carried out during the separation of the cut workpiece 10:

a first precut 12 is cut in a first method step. The first precut 12 extends straight, wherein an

end contour

26, 28 is formed on each of the two end sections of the second precut 15. The end profiles 26, 28 have the shape of a three-quarter circle and extend in sections transversely to the (horizontal) direction of the first precut 12.

In a later method step, a second precut 16 is cut, which likewise extends straight, except for two

end profiles

30, 32 forming a triple-quarter circle. When the second precut 16 is cut, it intersects the first precut 12 at the point of intersection 14. Since the two

separation incisions

11, 13 are only completed in a subsequent method step by means of the completion incisions 18, 20, 22 and 24 (see below), there is no risk: the cutting head collides with a severed or tipped sub-block of the workpiece 10 as it moves over the intersection point 14.

The first separation incision 11 is completed by two

linear completion incisions

18 and 20. The first completion cut 18 meets the first precut 12 in the region of the first end contour 28 and intersects the three-quarter circular first end contour 28. The second completion cutout 20 meets the first precut 12 at the second end contour 26 and intersects the three-quarter circular second end contour 26 here.

Accordingly, the second separation cut 13 is completed by further linear completion cuts 22 and 24: the first further completion cut 22 here intersects the first further end contour 32 of the further precut 16, while the second further completion cut 24 intersects the second further end contour 30 of the second precut 16.

The order in which the

supplementary cuts

18, 20, 22, 24 are cut is in principle arbitrary. Importantly, the method comprises the following steps: first, a cut is made in the region of the intersection point 14, and only then is the separation cuts 11 and 13 completed. The length of the

precuts

12, 16 and thus the distance of the completion cuts 18, 20, 22, 24 from the point of intersection 14 are selected to be so great that there is no risk of a collision of the cutting heads when the separation cuts 11, 13 are completed. It is clear that the point of intersection 14 shown in fig. 1 and the points shown on the ends of the remaining contour are only for illustrative visual representation, but that no point-like contour is cut out in the separating cut.

Fig. 2 schematically shows a plate-like (residual) workpiece 10 and a rectangular good piece 34. In cutting the good piece 34, a linear pre-cut 42 is cut that intersects the rectangular good piece outline 35 at an intersection point 50. The linear pre-cuts 42 are cut along with the good piece profiles 35 and are cut at the beginning or end of the cutting of the first good piece profile 35. The good piece 34 is thus cut simultaneously with the precut 42 and its corresponding end contour 46, which likewise has the shape of a three quarter circle.

In the workpiece 10 shown in fig. 2, during the separating cut, the first precut 42 is completed by the completion cut 38 into the first separating cut 39. The linear completion cut 38 intersects the pre-cut 42 at the end contour 46, as described in connection with fig. 1.

The point at which the completion cut 38 intersects the pre-cut 42 should be spaced sufficiently from the good profile 35 or from the intersection point 50. In this way it can be ensured that: the cut good pieces 34, which in some cases tip over with respect to the (remaining) workpiece 10, do not collide with the cutting head.

The completion incision 38 has an end section 37 in the example shown, with which end section 37 the further completion incision 36 meets, so that the completion incision 38 simultaneously forms a further precut of the first separation incision 39. The second separation cut 13 intersects the further pre-cut 38 of the first separation cut 39 at a further intersection point 52. The second separating cut 13 comprises, as shown in fig. 1, a second precut 16 and two further completing

cuts

22, 24. The second precut 16 has two

end profiles

30, 32 which form a triple quarter circle. In addition, good product profiles 35 can be connected with further (not shown) precuts. In this way, the remaining workpiece 10 can be divided into a plurality of smaller workpiece portions.

Fig. 3 shows examples of four different geometries of the end profiles 56, 58, 60, 62 of the respective precuts 64. The two

end profiles

56 and 58 shown on the left in fig. 3 are examples of polygonal segments: the end contour 56 shown at the top left is a triangular section, while the end contour 58 shown at the bottom left is a rectangular section. The end contour 60 shown at the top right is constructed in a semicircular manner. The end contour 62 shown on the lower right is three quarters circularly configured. The two

end profiles

60, 62 have a diameter D. The end contour 62 shown on the lower right in the form of a three-quarter circle is a preferred end contour, since a high process speed can be achieved by means of the circular contour and the three-quarter circle also has a large lateral extent to the remaining pre-cut 64 and thus enables a high process reliability in the completion of the corresponding separation cut.

Preferably, the diameter D of the rounded end profiles 60, 62 shown on the right in fig. 3 is at least 3 mm. In the case of thicker workpieces 10, the diameter D can be selected, if appropriate, to be significantly greater than 3 mm. The dimension of the diameter D can be adapted to the thickness of the workpiece 10, for example by increasing the diameter D in the case of an increase in the thickness of the workpiece.

Fig. 4 shows a further example of an end profile 62 in the form of a three-quarter circle formed on a precut 64. The linear section of the precut 64 transitions into the three quarters of the circle of the end contour 62 in the form of a rounded corner 66. The rounded corners 66 form circular arcs in the example shown, more precisely approximately quarter circles. The diameter D' of the radiused portion 66 is preferably at least half as large as the diameter D of the end profile 62. In the example shown, the diameter D' of the rounded portion 66 is as large as the diameter D of the triple quarter circle of the end profile 62. It can also be seen in fig. 4 that the rounded corner 66 is curved in the opposite direction to the rounded end contour 62.

Claims

1. A method for the split cutting of plate-shaped workpieces (10) by means of a machining beam, comprising:

cutting out at least one separating cut (11) for splitting a plate-shaped workpiece (10),

characterized in that said cutting of the separation cut (11) comprises at least one pre-cut and a subsequent cutting of at least one completion cut that completes the separation cut (11),

wherein the pre-cut comprises an intersection with a further pre-cut (16) of a further separating cut (13) or with a good piece profile (35), and wherein the pre-cut has an end section which meets the completing cut.

2. Method according to claim 1, characterized in that a good product profile (35) and a pre-cut starting from the intersection with the good product profile are cut while cutting the pre-cut, on which the end section is formed.

3. Method according to claim 1 or 2, characterized in that the end sections of the pre-cuts form end profiles (26, 28, 46) which extend at least in sections transversely to the direction of the pre-cuts.

4. Method according to claim 1 or 2, characterized in that the end sections of the further pre-cut (16) form a further end profile (30, 32) which extends at least sectionally transversely to the direction of the further pre-cut (16).

5. A method according to claim 3, characterized in that the completion cut of the separation cut (11) intersects the end profile (26, 28, 46).

6. Method according to claim 4, characterized in that a further completion cut (22, 24) of the further separation cut (13) intersects the further end profile (30, 32).

7. Method according to claim 3, characterized in that the end profile (26, 28, 46) has a section of a polygon or has a circular arc.

8. Method according to claim 4, characterized in that the further end profile (30, 32) has a section of a polygon or has a circular arc.

9. Method according to claim 7 or 8, characterized in that the length of the circular arc lies between a semicircle (60) and a triquetrum (62).

10. Method according to claim 7 or 8, characterized in that the circular arc has a diameter (D) of at least 3 mm.

11. Method according to claim 3, characterized in that the end profile starts from the linear section of the pre-cut with a rounded corner (66).

12. Method according to claim 4, characterized in that the further end profile starts from the linear section of the further pre-cut with a rounded corner (66).

13. The method of claim 11, wherein the end profile has a circular arc, and the diameter (D') of the rounded portion (66) is at least half as large as the diameter (D) of the circular arc.

14. Method according to claim 12, characterized in that the further end profile has a circular arc, the diameter (D') of the rounded portion (66) being at least half as large as the diameter (D) of the circular arc.

15. Method according to claim 1 or 2, characterized in that the plate-shaped workpiece is a plate-shaped residual workpiece.