EP2159013A1 - Cutting and scoring tool and method for its production - Google Patents

Abstract

A cutting bevel (3) with a flat, curved shape has an average surface roughness of not more than between 0.5 and 0.8 mu m and an arithmetical mean deviation of the roughness profile of not more than between 0.07 and 0.20 mu m according to DIN EN ISO 4287. A blade (1) has a thickness (D) between 0.3 and 2.0 mm, preferably about 0.7 mm.

Description

The invention relates to a cutting and scoring tool, preferably for a pressure cut, consisting of a band-shaped blade with a cutting edge and at least one cutting chamfer formed on a blade longitudinal side, starting from the cutting edge. Furthermore, the invention relates to a method for producing such a tool.

Such a tool is used in the paper processing and cartonboard industry to produce blanks for cartons or cartons from a paperboard, paperboard or even plastic material. This is usually done by punching devices that record the blade-shaped tools with at least the cutting process perpendicular to the material plane blade so that the present on a blade longitudinal cutting edge penetrates perpendicular to the material plane by lifting or rotational movement in the material. As a result, the blanks can be cut out on the one hand and on the other hand also scored to form fold lines by only partial cutting, embossed, grooved or grooved, wherein the fold lines a folding of the blank, z. B. allow for a box.

There are known cutting and scoring lines, which have either a ground chamfer or a chamfered chamfer. The ground chamfer can have a minimal hollow ground, resulting in excellent sharpness, so that a low punching pressure is required. However, the dimensional accuracy of such a chamfer is not satisfactory for all purposes.

By scraping is meant a machining, in which the workpiece to be machined relative to a stationary tool, for. B. a carbide tipped or the like is moved, d. H. The steel strip is pulled longitudinally through at least one drawing station to form the chamfer. Shaved chamfers have a very good dimensional stability due to their preparation in the drawing process, so that they are used for high demands on the dimensional accuracy. However, since the chamfer is weakly convex, the sharpness of this chamfer is small, and it does not act cutting, but pressing on the material, so that higher punching pressures are required.

In order to combine the advantages of the scraped and ground chamfer, the EP 0 234 009 B2 a cutting and scribe line consisting of a steel blade with a beveled chamfer formed on a blade longitudinal side, the blade being hardened in the area of the chamfer and the chamfer having a finish in the hardened area starting from the tip of the chisel. In the following sees the EP 0 234 009 B2 before that the hardened area is about 3/10 to 5/10 mm - measured from the tip of the tip - and the degree of hardness is about 66 HRc and that the chamfer in the hardened area, in particular to a final hardness in the range of 50 to 64 HRc, preferably in the range of 57 to 59 HRc, is tempered. Such tools have proven themselves in practice. The tool has a comparatively increased service life, and the formation of cutting dust is largely avoided. The cutting and scoring tool has a schabriefenfreie from the tip of the claw-free honed surface. The bevel angle of the fine grinding is in an advantageous embodiment about 45 ° to 60 °.

The DE 20 2007 013 402 U1 describes a cutting line for cutting sheet materials comprising a steel strip having a cutting edge, two side surfaces and a spine, further comprising first planar facets on both sides of the steel strip, a first rounded transition between the side surfaces and the first facets, and a second rounded transition between the first facets and the cutting edge. Here, the point angle at the cutting edge is greater than the angle between the first facets. To produce the second rounded transition, second facets may be introduced on both sides of the steel strip between the first facets and the cutting edge. At this known cutting line is provided in preferred embodiments that the first and the second rounded transition, the first facets and / or the second facets are polished. As a result, a simple production of the transitions and a smoothing of the Schabriefen be achieved in order to reduce the accumulated dust volume.

The high demands on the tools used for cutting and scoring are derived from the fact that the cut material must have a high quality of cut or quality. This includes adherence to a geometrically accurate cut surface, the absence of banding and undulating lobes in the cutting direction, the absence of cracks in front of the cutting edge, low roughness of the cut surface, and a minimal amount of cutting dust. For the tools, this means the lowest possible production costs and short trimming times when resizing the punching dies, that a high cutting edge, namely a very low height tolerance of the blade, dimensional accuracy of the chamfer, high tool life, in particular by strength and hardness of the blade, and the aim is to ensure that the cutting process proceeds optimally with regard to a cutting (non-pressing) penetration into the material to be punched and with regard to a low punching pressure by means of minimal cutting resistance and small frictional forces during cutting.

The invention has for its object to further improve a cutting and scoring tool of the type mentioned in such a way that it better satisfies the said complex requirements, and to provide a method for its production.

According to the invention, this is achieved for the tool in that the cutting bevel has an average roughness depth R _Z of not more than 0.8 μm and an arithmetic mean roughness R _a of not more than 0.20 μm according to DIN EN ISO 4287 (or earlier standard DIN 4768).

By definition, the average roughness depth R _Z is the mean value of the single roughness depths of successive individual measuring sections, with individual roughness being the vertical distance of the highest from the deepest profile point in a measuring section understand is. The average roughness R _a is the arithmetic mean of the amounts of all profile values of the roughness profile.

For the inventive method for producing the cutting and scoring tool according to the invention, the object is achieved in that by a stepped, wet and / or dry running finish micromachining on the cutting bevel values of the average roughness R _z of not more than 0.8 microns and of an arithmetic mean roughness R _a of not more than 0.20 μm in accordance with DIN EN ISO 4287.

In a preferred embodiment of the tool according to the invention, it can be provided that the cutting bevel has an average roughness depth R _Z of not more than 0.7 μm, preferably not more than 0.5 μm, and an arithmetic mean roughness R _a of not more than 0.10 μm , preferably not more than 0.07 microns, according to DIN EN ISO 4287 has.

The invention is based on the finding that the surface quality of the cutting bevel corresponding to the averaged surface roughness R _Z and the arithmetic mean roughness R _{a are} in direct causal relationship with the cutting action of the cutting and scoring tool according to the invention. For example, under otherwise unchanged conditions, a punching force reduction can be achieved by 30 to 50 percent. In case of extreme straightness, a height tolerance of the cutting edge in the range of 0.002 mm to +/- 0.02 mm per running meter can be achieved, whereby the dressing time can be significantly reduced.

The inventive values of the average roughness R _z and the arithmetic mean roughness R _a can be achieved by means of a special finish micromachining step-wet and / or dry-using grinding wheels having a Mohs hardness of more than 9 or a Knoop hardness of over 4500 and also includes the use of leather, felt and fleece to treat the chamfer surface. In the abrasive bodies, it may preferably be cubic boron nitride or diamond, z. B. in granulation of 150 to 240 US mesh or 280 to 600 US mesh according to ASTM E 11 or in resin bond as B64-46 or D54-15, the concentration of Abrasive is tuned to the process and can be in particular at 1 to 4 carats per cm ³ .

Prior to finish micromachining, the cutting bevel may be scraped, ground, etched and / or eroded. A preferred technological variant consists in that the phase is ground and / or scraped in a manner known per se, then hardened, tempered and ground.

The hardening can be realized inductively, by means of laser, plasma or electron beam, preferably with air cooling and optionally under protective gas. Hardening can be done before and / or after the finish micromachining.

For grinding, preferably 800 to 1500, preferably 1000 and 1200, round grain grinding wheels - grain size distributions according to the standard of FEPA (Fédération Europeene des Fabricants de Produits Abrasifs) for abrasive grains - are used, in particular no grinding along the cutting and scoring tool according to the invention but the discs with respect to their direction of rotation transversely to the longitudinal axis of the cutting and scoring tool according to the invention are placed standing on the chamfer surface.

Fig. 1

im Querschnitt und vergrößert gegenüber der natürlichen Größe, eine erste Ausführungsform eines erfindungsgemäßen Schneid- und Ritzwerkzeuges,

Fig. 2

in einer der Fig. 1 entsprechenden Darstellung, eine zweite Ausführungsform eines erfindungsgemäßen Schneid- und Ritzwerkzeuges,

Fig. 3

ein Profilogramm der Oberfläche einer Schneidfase eines nicht erfindungsgemäßen Schneid- und Ritzwerkzeuges,

Fig. 4

ein Profilogramm der Oberfläche einer Schneidfase eines erfindungsgemäßen Schneid- und Ritzwerkzeuges,

Fig. 5 bis 8

weitere Ausführungsformen eines erfindungsgemäßen Schneid- und Ritzwerkzeuges.

Further advantageous embodiments of the invention are contained in the subclaims and the following description. On the basis of several embodiments shown in the accompanying drawing figures, the invention will be explained in more detail. Show it:

Fig. 1

in cross-section and enlarged in relation to the natural size, a first embodiment of a cutting and scoring tool according to the invention,

Fig. 2

in one of the Fig. 1 corresponding representation, a second embodiment of a cutting and scoring tool according to the invention,

Fig. 3

a profilogram of the surface of a cutting bevel of a cutting and scoring tool not according to the invention,

Fig. 4

a profilogram of the surface of a cutting bevel of a cutting and scoring tool according to the invention,

Fig. 5 to 8

further embodiments of a cutting and scoring tool according to the invention.

In the various figures of the drawing, like parts are always provided with the same reference numerals, so that they are usually described only once in each case.

As first Fig. 1 shows, there is a cutting and scoring tool according to the invention, which is preferably used for a pressure cut, from a band-shaped blade 1 with a cutting edge 2 and at least one formed from the cutting edge 2 Schneidfase 3 on a blade longitudinal side 4. A between cutting chamfer and a center plane XX formed by the blade 1 tip angle μ at the cutting edge 2 may be in a range of 20 ° to 90 °, preferably in the range of 30 ° to 54 °.

According to the invention, it is provided that the cutting bevel 3 has an average roughness depth R _Z of not more than 0.8 μm and an arithmetic mean roughness R _a of not more than 0.20 μm according to DIN EN ISO 4287. Such values are indicated by the profile picture P3 in FIG Fig. 1 indicated, which a section of the in Fig. 4 represents illustrated profilogram according to the invention.

Preferably, the chamfer 3 may have an average roughness R _z of not more than 0.7 μm, in particular not more than 0.6 μm, and an arithmetic mean roughness R _a of not more than 0.10 μm, preferably not more than 0 , 07 μm, according to DIN EN ISO 4287.

In the execution according to Fig. 1 , but also in the comments according to Fig. 2 . 7 and 8 , The blade longitudinal sides 4 are each formed symmetrically to the center plane XX by the blade 1 and have two similar cutting chamfers 3.

In the statements according to Fig. 5, 6 It is provided that the blade longitudinal sides 4 are formed asymmetrically with respect to a longitudinal plane YY by the cutting edge 2 and have two dissimilar, especially unequal large cutting chamfers 3. It could also be present only a cutting chamfer 3.

To produce the blade of the tool according to the invention, a known technological treatment can be carried out by pulling a flat material made of spring band steel for the blade 1 with a thickness of 0.4 to 2 mm in a hard metal drawing block, so that one or both sides Cutting chamfer 3 is generated. This is called a so-called scraped bevel. The chamfer 3 is made with a certain excess, in particular with an oversize 2/100 to 4/100 mm. The cutting bevel 3 is now - at least in a tip region 5 - hardened, preferably induction hardened with a depth of insertion of 3/10 to 5/10 mm measured from the cutting edge 2 of. The curing is preferably carried out to a hardness of 66 HRc. After curing, tempering takes place in the same region 5, preferably to a final temper hardness of 57 to 59 HRc. Thereafter, the chamfer 3 can receive a fine grinding, which is carried out such that the existing after scraping oversize is removed. As a result, the softer outer skin of the hardened and tempered Schneidfase 3 is taken away at the same time. By this fine grinding, which can be advantageously carried out with an added grinding wheel, the dimensional accuracy of the scraped Schneidfase 3 is not impaired, but is prevented by the fine ship that grooves occur in the chamfer surface.

This is followed according to the invention for setting the values of the average roughness depth R _Z and the arithmetic mean roughness R _{a of} the cutting bevel 3, followed by a special finish micromachining. This can in particular in several successive steps stepped - wet and / or dry - using abrasive with a Mohs hardness of over 9 or a Knoop hardness of over 4500 run.

U. a. For example, in the course of the finish micromachining of the chamfer 3, a lapping process with the abovementioned abrasives may be used, the abrasives being distributed in a liquid or paste. The cutting chamfer 3 is provided with a Lapping disc processed, with a lapping mixture is between this and the cutting bevel 3, which is a suspension of carrier medium (Läppflüssigkeit), possibly lubricant and Läppkorn (abrasive). As Läppflüssigkeiten example, medium-viscosity all-purpose oils are suitable. The concentration of the abrasive particles is tuned to the process and may in particular be 1 to 4 carats per cm ³ .

In the abrasive bodies, it may preferably be cubic boron nitride or diamond, z. B. in granulation of 150 to 240 US mesh or 280 to 600 US mesh according to ASTM E 11 or on a disc in resin bond as B64-46 or D54-15 act. (B is boron nitride, D is diamond, data 64-46 and 54-15 refer to grain sizes according to FEPA).

Leather, felt, wool, silk, fleece and porous neoprene can preferably also be used in the intermediate and / or finishing stage of the cutting bevel 3.

With the cutting and scoring tool according to the invention punching force reductions can be achieved by 30 to 50 percent and a height tolerance of the cutting edge of not more than +/- 0.02 mm per meter, so that the dressing time can be significantly reduced.

While at the in Fig. 1 The first and second embodiments, which are formed on both sides and symmetrically formed, are each directly adjacent to a wall section 6 whose surface runs parallel to the center plane XX of the blade 1 Fig. 2 illustrated second cutting embodiment of a cutting and scoring tool according to the invention that each Schneidfase 3 each adjacent to a standing at a smaller angle to the center plane XX Anschlußfase 7, which then connects to the wall section 6, the surface parallel to the mid-plane XX of the blade. 1 runs.

The not cutting acting Anschlußfase 7 requires no special finish micromachining. It can - as usual for the production of chamfers and also, as already mentioned, for the first method section for the production of the chamfer 3 applicable be prepared by processes or process steps such as scraping, grinding, fine grinding, etching and / or erosion. For this purpose, an average roughness R _z and an arithmetic mean roughness R _a according to DIN EN ISO 4287 are characteristic, which are significantly greater than the respective inventively provided values. Such surface quality values for the terminal bevel 7 are indicated by the profile image P7 in FIG Fig. 2 indicated, which a section of the in Fig. 3 represented profilogram with known on cutting chamfers existing surface quality.

3 and 4 contain the recorded profilograms and the values of the average roughness depth R _Z and the arithmetic mean roughness R _a . The average roughness _Ra on the surface of the present invention formed bevel ( Fig. 4 ) is 0.07 .mu.m and the average roughness R _z is 0.43 .mu.m, while the corresponding values of the non-inventively designed surface of the terminal bevel 7 at 0.12 .mu.m and 0.88 .mu.m.

3 and 4 contain further and more detailed information about the measuring device and the measuring parameters. For the measurement, the stylus method was used, using the surface roughness tester "Surftest 301" Mitutoyo was used. The stylus method is a method for the metrological description of surfaces, wherein for roughness measurement a probe tip made of diamond is moved at a constant speed over the surface of the sample. The roughness measurement is based on the DIN 4762, 4768, 4772, 4775 and ISO 4288 standards. The measuring profile results from the vertical positional shift of the probe tip, which is usually detected by an inductive distance measuring system. For the metrological description of a surface, the standardized roughness parameters, such as the average roughness depth R _Z and the arithmetic mean roughness R _a , are obtained from the measurement profile. For this purpose, DIN EN ISO 4287 is binding. Out 3 and 4 However, it is clear that the device works according to the corresponding Japanese standard JIS2001. In particular, from the FIGS. 3 and 4 The details of the filter used, the evaluation length, the cut-off wavelength λ _C and the feed are to be taken. When comparing the profilograms, it should be noted that the measurements according to Fig. 4 at twice the feed rate ("M-Gesch") as in Fig. 3 were made. As a further measured value, the average roughness Rq contained at 0.16 ( Fig. 3 ) or 0.08 μm ( Fig. 4 ) lies. By definition, the average roughness value Rq is the root mean square value of all profile values of the roughness profile.

In the Fig. 5 to 8 shown further embodiments of a cutting and scoring tool according to the invention show that this can be produced in a variety of forms. Thus, it has already been described that in the embodiments according to Fig. 5, 6 it is provided that the blade longitudinal sides 4 are formed asymmetrically and have two non-uniform cutting chamfers 3. Here, the cutting chamfers 3 in these, as well as the previous embodiments, just trained.

But it is also possible that the cutting bevel 3 is curved, as this FIGS. 7 and 8 demonstrate.

Thus, the execution according to Fig. 7 a cutting chamfer 3, which is curved over its entire length with a first radius of curvature R1 and passes over a second radius of curvature R2 in the wall portion 6, whose surface is parallel to the center plane XX of the blade 1.

Fig. 8 shows a cutting and scoring tool according to the invention, in which the cutting bevel 3 at least two continuously merging areas 3a, 3b, and that at least a first, arranged in the vicinity of the cutting edge 2 region 3a with - seen in cross section - convex curvature and at least one at the convex portion 3a subsequent second region 3b with - seen in cross-section - concave curvature. The latter is located in the vicinity of the transition point of the cutting bevel 3 to the wall portion 6, whose surface is parallel to the center plane XX of the blade 1. The cutting bevel 3 has - seen in cross section - at least partially an approximately S-shaped or inverted S-shaped contour.

The invention is not limited to the illustrated embodiments, but also includes all the same in the context of the invention embodiments. Thus, with regard to further advantageous technical features with which the person skilled in the art can provide the invention without departing from the scope thereof, reference is made to those already made mentioned EP 0 234 009 B2 , but also in terms of the possible geometric design of the blade 1 and the chamfers 3, 7 in full on the DE 197 41 089 A1 , the DE 10 2007 031 904 A1 and the EP 1 10 685 B1 directed.

Furthermore, the invention has hitherto not been limited to the feature combination defined in claim 1, but may also be defined by any other combination of specific features of all individually disclosed individual features. This means that in principle virtually every individual feature of claim 1 can be omitted or replaced by at least one individual feature disclosed elsewhere in the application. In this respect, the claim 1 is to be understood only as a first formulation attempt for an invention.

reference numeral

1

blade

2

cutting edge

3

bevel

3a

convex range of 3

3b

concave area of 3

4

Sound long side

5

tip area

6

Wall section of 1

7

Terminal chamfer between 3 and 6

D

Thickness of 1 (6)

P3

Profile of 3 (according to the invention)

P7

Profile of 7

R1

Radius of 3

R2

Radius at the transition 3/6

R _Z

roughness

R _a

roughness

X X

Middle level of 1

Y-Y

Longitudinal plane from 1 through 2 ( Fig. 5, 6 )

Claims (23)

Cutting and scoring tool, preferably for a pressure cut, consisting of a band-shaped blade (1) with a cutting edge (2) and with at least one cutting edge (3) formed on a blade longitudinal side (4) starting from the cutting edge (2),
characterized in that the cutting bevel (3) has an average roughness (R _Z ) of not more than 0.8 μm and an arithmetic mean roughness (R _a ) of not more than 0.20 μm according to DIN EN ISO 4287. Cutting and scoring tool according to claim 1,
characterized in that the cutting bevel (3) has an average roughness (R _Z ) of not more than 0.7 μm, preferably not more than 0.5 μm, and an arithmetic mean roughness (R _a ) of not more than 0.10 μm , preferably not more than 0.07 microns, according to DIN EN ISO 4287 has. Cutting and scoring tool according to claim 1 or 2,
characterized in that the cutting chamfer (3) is flat. Cutting and scoring tool according to claim 3,
characterized in that the cutting chamfer (3) is curved (R1, R2, 3a, 3b) is formed. Cutting and scoring tool according to one of claims 1 to 4,
characterized in that the blade (1) has a thickness (D) in the range of 0.3 to 2.0 mm, preferably a thickness (D) of about 0.7 mm. Cutting and scoring tool according to one of claims 1 to 5,
characterized in that the blade longitudinal sides (4) symmetrical to the center plane (XX) by the blade (1) are formed and have two similar cutting chamfers (3). Cutting and scoring tool according to one of claims 1 to 5,
characterized in that the blade longitudinal sides (4) with respect to a longitudinal plane (YY) by the cutting edge (2) are asymmetrical and have two dissimilar, especially unequal large Schneidfasen (3) or only one Schneidfase (3). Cutting and scoring tool according to one of claims 1 to 7,
characterized in that a point angle (μ) at the cutting edge (2) in the range of 20 ° to 90 °, preferably in the range of 30 ° to 54 °. Cutting and scoring tool according to one of claims 1 to 8,
characterized in that the blade (1) is hardened in a tip region (5) in the vicinity of the cutting edge (2), preferably in the region of the cutting bevel (3), in particular to 66 HRc. Cutting and scoring tool according to one of claims 1 to 9,
characterized in that the blade (1) in a tip region (5) in the vicinity of the cutting edge (2), preferably in the region of the cutting bevel (3), tempered, in particular to a final hardness in the range of 50 to 64 HRc, preferably in the range from 57 to 59 HRc, tempered, is. Cutting and scoring tool according to one of claims 1 to 10,
characterized in that the cutting bevel (3) is scraped, ground, etched and / or eroded. Cutting and scoring tool according to one of claims 1 to 11,
characterized in that the cutting bevel (3), in particular in the hardened tip region (5), starting from the cutting edge (2) is processed by fine grinding, wherein the Abbeiffmaß the fine grinding is preferably 2/100 to 4/100 mm. Cutting and scoring tool according to one of claims 1 to 12,
characterized in that the blade (1) consists of spring band steel. Cutting and scoring tool according to one of claims 1 to 13,
characterized in that the values of the average roughness (R _Z ) and the arithmetic mean roughness (R _a ) are adjusted by a stepped, wet and / or dry finish micromachining process using grinding wheels of a Mohs hardness greater than 9 or a Knoop hardness of over 4500 expires. Cutting and scoring tool according to one of claims 1 to 14,
characterized in that the values of the average surface roughness (R _Z), and the arithmetic average roughness (R _a) using abrasives of cubic boron nitride or diamond are set. Cutting and scoring tool according to one of claims 1 to 15,
characterized in that the values of the mean roughness (R _Z ) and the arithmetic mean roughness (R _a ) are determined using grits in a grit size of 150 to 240 US mesh or 280 to 600 US mesh according to ASTM E 11 or in synthetic resin bond B64-46 or D54-15 are set. Cutting and scoring tool according to one of claims 1 to 16,
characterized in that the values of the mean roughness (R _Z ) and the arithmetic mean roughness (R _a ) are set using abrasives in a concentration of 1 to 4 carats per cm ³ . Cutting and scoring tool according to one of claims 1 to 17,
characterized in that the values of the mean roughness depth (R _Z ) and the arithmetic mean roughness (R _a ) by means of a particular Stepped finishing micro-machining can be set, which includes a treatment of the surface of the cutting bevel (3) with leather, felt, wool, silk, fleece and / or porous neoprene. Cutting and scoring tool according to one of claims 1 to 18,
characterized in that the values of the average roughness (R _Z ) and the arithmetic mean roughness (R _a ) are adjusted by means of a finish micromachining employing a lapping mixture which is a suspension of abrasive bodies in a carrier medium, optionally a lubricant contains. Method for producing a cutting and scoring tool according to one of Claims 1 to 19,
characterized in that by a stepped, wet and / or dry running finish micromachining on the Schneidfase (3) values of an average roughness (R _Z ) of not more than 0.8 microns and an arithmetic mean roughness (R _a ) of not more be set as 0.20 μm according to DIN EN ISO 4287. Method according to claim 20,
characterized in that the finish micromachining is accomplished using abrasive articles having a Mohs hardness greater than 9 or a Knoop hardness greater than 4500. Method according to claim 20 or 21,
characterized in that the blade (1) before and / or after the finishing micromachining in a tip region (5) in the vicinity of the cutting edge (2), preferably in the region of the cutting bevel (3), in particular to 66 HRc, is cured. Method according to one of claims 20 to 22,
characterized in that the blade (1) in a tip region (5) in the vicinity of the cutting edge (2), preferably in the region the cutting bevel (3), tempered, in particular to a final hardness in the range of 50 to 64 HRc, preferably in the range of 57 to 59 HRc, annealed, is.

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