EP1791677A1

EP1791677A1 - Method and device for grinding a cutting tool, especially a knife

Info

Publication number: EP1791677A1
Application number: EP05782443A
Authority: EP
Inventors: Joachim Droese; Andreas Gross
Original assignee: Zwilling JA Henckels AG; Heinz Berger Maschinenfabrik GmbH and Co
Current assignee: Zwilling JA Henckels AG; Heinz Berger Maschinenfabrik GmbH and Co
Priority date: 2004-09-03
Filing date: 2005-09-02
Publication date: 2007-06-06
Also published as: US20080188164A1; CN101052496A; DE102004063974A1; DE102004043157A1; WO2006024536A1

Abstract

The invention relates to a method for grinding a cutting tool, especially a knife. The aim of the invention is to provide a method which allows configuration of individual leaf or blade geometries at comparatively low costs. For this purpose, the cutting tool is contacted with the effective surface of a grinding device, and the cutting tool and the grinding device can be displaced in relation to each other by at least three degrees of freedom.

Description

Method and device for grinding a cutting tool, in particular a knife

The invention relates to a method and a device for grinding a cutting tool, in particular a knife.

As is known, the blade or the blade of a cutting tool is to be finished by means of grinding. By such a grinding process, the blade of the cutting tool not only receives its final shape, also the surface finish of the blade or the blade cutting edge is set to completion.

For the purposes of the invention, cutting tools are to be understood as meaning, in particular, knives. But other cutting tools, such as scissors, are included in the inventive method.

The term "knife" is to be understood in the general form according to the invention and includes a variety of types of knives, such as kitchen knives, chef's knives, fish knife, meat knife, Ausbeiner, cleaver, etc., this list is not exhaustive.

According to the grinding machining method known from the prior art, high-quality knives obtain their finish by a two-stage grinding process. In the first step, the blade or the blade of the knife is successively ground on the left and the right side, so that a Double conical cross section is created. As part of the grinding process, certain specified dimensions, for example, the back strength or the wading strength set. As a grinding tool are so-called cup wheels, in which the abrasive material is formed in the form of a ring, in a diameter of 450 mm to 710 mm depending on the size of the knife used. The cup wheel has a chamfer, so that the blade is inclined to the Lot of the grinding wheel axis at a certain angle. As a result of this geometry arrangement, the cut of the two leaf sides is slightly convex depending on the diameter of the disc. The geometry of the blade in the longitudinal direction is also dictated by the grinding wheel geometry. This known from the prior art arrangement is therefore useful, inter alia, to produce a certain stability of the blade against bending despite thinly ground Wate. This flexural rigidity thus necessarily results from the spatial arrangement of the blade and the grinding wheel geometry.

In a second step, the sheet is then tamped on both sides with similar geometry. "Spliced" means that with a finer abrasive grain, the surface roughness of the leaf sides ground in the first step is leveled The roughness characteristic values drop from about 10 μ to about 2 μ due to the plaque. which is characterized by an increase in the corrosion resistance of the leaf surface due to lower surface roughness.

The known from the prior art two-stage process, which is preferably carried out on robot-assisted machines, disadvantageously both investment funds for the machines and costs in terms of machine operation, abrasive consumption, coolant supply, footprint and correspondingly high dead times caused by Mehrfachrüstgänge. In addition, it is not possible with the arrangement known from the prior art, individually form different blade or blade geometries. In addition, the plumbing process is highly contaminant, requiring elaborate cleaning of both the machines and the finished cutting tools. Starting from the above-described prior art, it is an object of the invention to provide a method for grinding a cutting tool, in particular a knife, which allows the formation of individual blade or blade geometries and is also comparatively less costly. In addition, to be proposed with the invention, a device for grinding the blade of a cutting tool, in particular a knife.

To solve the above object, the method proposes a method for grinding a cutting tool, in particular a knife, in which the cutting tool is brought into contact with the working surface of a grinding device, wherein the cutting tool and the grinding device are moved relative to each other in at least three degrees of freedom.

The method implementation according to the invention advantageously allows the formation of arbitrary cutting tool geometries, that is, blade and / or blade geometry. In addition, a finishing of the cutting tool can be carried out with the method according to the invention, so that the necessary according to the method known from the prior art process step of Piiestens can be completely eliminated. In addition, with the method according to the invention an extremely short compared to the prior art process, that is, processing time can be achieved, so that the inventive method is extremely effective. Thus, tests have shown that machining time reductions of up to 50% can be achieved with the method according to the invention.

The inventive method is characterized in that the cutting tool and the grinding device are moved in at least three degrees of freedom relative to each other. Depending on the device used, this can be achieved in different ways. Thus, for example, be provided that the cutting tool performs no movement. In this case, the grinding device rotatably moves about an axis of rotation on the one hand and in at least two transverse directions translationally on the other hand. In overlay of these three movements of the grinder can the cutting tool to form an individually predetermined, that is arbitrarily specified grinding geometry can be edited.

As an alternative to the above-described method implementation, it may also be provided that the sliding device is stationary, that is does not move. In this case, the cutting tool is both rotationally about an axis of rotation and translationally moved in two transverse directions of movement, in combination of this movement performed by the cutting tool is also a result in its geometry individually, that is arbitrarily formed cutting tool.

In a third alternative embodiment of the invention, both the cutting tool and the grinding device are moved. In this case, both the cutting tool and the grinding device are preferably moved rotationally about a respective associated axis of rotation. In addition, both the cutting tool and the grinding device are moved in translation, wherein it can be provided that the grinding device is moved translationally in the direction of a first direction of movement and the cutting tool is moved translationally in a second direction of movement, wherein the first and second directions of movement are transversely, preferably orthogonal to each other , It can also be provided that both the cutting tool and the grinding device are each moved translationally in two mutually perpendicular directions of movement.

It is crucial for the inventive method that grinding device and cutting tool are moved independently of each other, wherein in superimposition of the grinding device and / or the cutting tool relative movements a Schleifendgeometrie the cutting tool individually, that is generated arbitrarily specifiable. In this sense, the term "degree of freedom" means the relative degree of freedom resulting in superposition of the possible movements of the cutting tool on the one hand and the grinding device on the other hand.

As already indicated above, the surface of the cutting tool which is to be machined between the working surface of the grinding device and the surface of the cutting tool to be processed resulting relative movement can be generated in different ways. Thus, it can be provided that the grinding device is moved rotationally and / or translationally. It can also be provided that the cutting tool is moved rotationally and / or translationally. In what combination these possible movements are superimposed is not essential to the invention. Alone, it is important that the grinding device and the cutting tool are rotationally or translatorily moved so that, as a result, there is a movement overlay which is suitable for forming the desired cutting tool geometry, in particular blade geometry. For this purpose, it is provided according to a special feature of the invention that both the grinding device and the cutting tool are driven in rotation, in the same direction. Furthermore, the grinding device is translationally movable in a direction transverse to the direction of movement of the cutting tool. In order to form special blade geometries, it may moreover be provided that the cutting tool is moved rotationally about a further axis of rotation. The imagination knows no bounds.

According to a particular embodiment, the invention provides a method in which the cutting tool clamped in a holding device is guided past one of its leaf sides to be machined on a rotatably arranged grinding device, in which the active surface of the grinding device with the blade side of the cutting tool to be machined substantially in Line contact brought and the grinding device is moved transversely to its axis of rotation in dependence of the blade geometry to be generated.

According to this method implementation, the sheet side to be processed of the cutting tool clamped in a holding device is guided past the effective surface of the grinding device in a traversing movement. The grinding device is for example in the manner of a rotating cylinder, preferably annular, wherein the frontal surface of the annular cylinder has the abrasive as the active surface. The active surface of the grinding device is brought in the course of passing the sheet side to be processed with this substantially in line contact. The holding device and the grinding device are driven in such a way that the line contact between the sheet to be processed on the one hand and the grinding device on the other hand migrates over the surface of the sheet side to be processed in the direction transverse to the longitudinal extent of the sheet. Preferably, under computer control, the grinding device and / or the holding device is moved transversely to the axis of rotation of the grinding device as a function of the sheet geometry to be produced, that is to say the grinding device and / or the holding device are moved in the direction of the sheet side to be processed or in the opposite direction. and moved. In superposition of this translational movement of the grinding device with the movement of the holding device, a desired sheet geometry can be generated in an advantageous manner.

According to a first alternative of the above-described method implementation is provided that the holding device is rotatable and that the cutting tool on at least one part-circular path on the grinding device, d. H. the active surface of the grinding device is passed. Both the holding device and the grinding device are rotatable according to this embodiment. In this case, the holding device and the grinding device are preferably driven in the same direction, so that the grinding device and the cutting tool carried by the holding device perform an opposite relative movement in the region of their line contact.

In the course of carrying out the method, first the area of the later wate of the sheet side to be processed is brought into line contact with the effective surface of the grinding device. In order to be able to form the sharpest, that is to say thin, wad, the grinding device is arranged comparatively close to the side of the sheet to be processed. In the further course of the procedure, the sheet page to be processed is guided past the knitting surface of the grinding device while maintaining the line contact. To form, for example, a crowned blade geometry, the grinding device is moved in the course of passing on the sheet side to be processed translationally transversely to its axis of rotation in a direction away from the sheet side to be processed direction. In the course of this process, a sheet geometry with thin results ground wate and a comparatively thickly ground blade or blade body.

The above-described method has the advantage that, depending on the feed movement of the grinding device and / or the holding device, any desired sheet geometries can be formed. Unlike previously known from the prior art, not only crowned blade geometries can be formed, but it is possible to create any blade geometries. Thus, for example, cross-sectional or tapered wedge geometries, trapezoidal geometries or other types of geometry can be generated. In addition, it is possible to process the transition between the leaf side and leaf spine, for example in the form of a rounding. Such processing options are not possible with the known from the prior art method for grinding.

In addition, it is advantageous that a wear-related wear of the grinding device can be compensated by a translational adjusting movement transversely to the axis of rotation of the grinding device. The grinding result is therefore not affected by the wear caused by wear of the grinding device. Feed movement and adjustment of the grinding device are superimposed in the context of the process implementation to a total movement, so that regardless of a wear-related wear of the grinding device always the same grinding result is achieved.

Another advantage of the method according to the invention is that not only continuously extending blade geometries can be formed. It is also possible to form visible edges running in the transverse or longitudinal direction of the sheet. These visible edges arise as a result of a region-wise stronger material density and cause a technical stiffening, similar to a stiffening rib or a bead. Such an embodiment is particularly advantageous in the formation of comparatively thin cutting tool blades or blades. In general, namely, that a comparatively thin sheet provides a much better cutting result than a thick trained sheet. However, thin-formed sheets have the disadvantage that they have a corresponding to the sheet thickness low bending and / or Torsionsflächenmoment. As a result, a thinly-formed one tends Blade during bending to bend, which is perceived by the user as disadvantageous, because he can conduct the knife less well overall. An abrasive machining process according to the invention provides a remedy. Namely, this makes it possible to form a reinforcement outside the wading range, which stiffens the cutting tool blade as a whole, so that it is less susceptible to bending or torsional loads. Comparatively thin trained tool blades or blades can be stiffened so on the biaxial surface moment or the polar moment of area. As a consequence, knives can be formed which, because of the comparatively thin blade, have good cutting properties but at the same time are very dimensionally stable due to their stiffening. Such knives are not known from the prior art. Even blades with an asymmetric cross-section can be produced by this method.

The transition between the sheet side and the sheet back can be formed at will, for example rounded, by means of the method according to the invention. The grinding operation of the transition between the sheet side and the sheet back is made possible by a feed movement of the grinding device in the direction of the sheet side to be processed, as a result of which the sheet side is processed in the direction of the sheet back. Depending on the feed movement, a rounded transition or even an oblique transition between the sheet side and sheet back can be formed.

Unlike the prior art, the grinding device can be driven at a very high rotational speed. This is possible because, unlike the prior art, the grinding device is only brought into line contact with the sheet side to be processed. The designed for example as an annular cylinder grinding device can therefore be of a much smaller diameter than the known from the prior art cup wheels, which allows a much higher speed. The advantage of the higher speed is that when using a corresponding abrasive, which is arranged on the cylinder outer surface of the grinder, the sheet side to be processed can be ground in a process step in plush quality. Unlike previously known from the prior art, it is thus using the method according to the invention not necessary to perform the blade or sheet finish in a two-stage grinding process. Costly conversion operations can be omitted in an advantageous manner.

The grinding device is preferably designed as a tapered cylinder. Due to this shape of the grinding device automatically results in a rejuvenating to the tip of the sheet blade geometry.

According to an alternative embodiment, it is provided that the holding device is arranged translationally movable in at least two mutually transverse directions and that the cutting tool is guided past the effective surface of the grinding device in a superposition of these two directions of movement. In contrast to the above-described, first alternative, therefore, the holding device is not rotatable but arranged only translationally movable. It is provided that the holding device is translationally movable in at least two transverse directions, so that in the superposition of these two directions of movement of the recorded by the holding device cutting tool is preferably performed on at least one part-circular path. Thus, although the holding device is not arranged to be rotatable by itself, the cutting tool received by the holding device is guided past the grinding device on a path, preferably in the form of a circular path, at least partially circular, whereby this path results in a superposition of the translatory movements of the holding device. Advantage of this embodiment is that the entire machine system, that is, in particular, the machine parts carrying the holding device can be made much stiffer. Deviations from the desired grinding geometry, which could possibly occur as a result of insufficient rigidity of the entire device, are thus avoided. The grinding result corresponds to a superimposed translational movement of the holding device to that, as it adjusts to a rotatable holding device, so that can be achieved with the alternative embodiment of the invention, the advantages already described above. Whichever process variant is chosen is of decisive importance alone that the grinding device with the blade side of the cutting tool to be machined substantially in Placed line contact and is moved in dependence on the sheet geometry to be generated translationally transverse to the axis of rotation of the grinding device.

According to a further feature of the invention, it is provided that, in a first grinding operation, the one side of the sheet and, in a second grinding operation, the other side of the sheet are finished in one go. The grinding tools to be processed are thus first clamped for processing the one sheet side in the holding device provided for this purpose. Then, the grinding process is performed in the above-described manner. When this is finished, the cutting tools are re-clamped for the purpose of processing the other side of the sheet, and this still unprocessed sheet side is processed in a further grinding operation.

If the holding device according to the first embodiment of the invention rotatably formed, it can be provided that it is also arranged translationally transversely to its own axis of rotation movable. Velvet clamped cutting tool, the holding device can be moved up to the grinding device at the beginning of a grinding process. The effected during the grinding process feed movement is then realized alone on the translationally movable arrangement of the grinding device. If the holding device according to the second method alternative is arranged to be translationally movable in at least two directions which are transverse to one another, then the feed movement moved during the grinding process can take place both via the translationally movable arrangement of the grinding device and via the translationally movable arrangement of the holding device. A combined movement of holding device and grinding device is conceivable.

According to a further feature of the invention can be provided that the movements of the grinding device and / or cutting tool are performed oscillating, both in terms of rotational and translational movement. The frequency of the oscillating movement is advantageously adjustable and can also be varied during the grinding process. With respect to the rotational movement of both the grinding device and the cutting tool may be provided in this context that the oscillating movement performed by a certain angle is, the grinding device or the cutting tool so to speak, moved up and down. The same can be provided for one or more of the translational movements, which then results in a reciprocating motion.

To solve the above object is proposed on the device side, a device for grinding a cutting tool, in particular a knife, with a holding device for receiving the cutting tool to be machined and a grinding device, wherein the holding device and the grinding device with respect to at least three degrees of freedom relative to each other are arranged.

As already described with reference to the method according to the invention, the special feature of the device according to the invention is that the holding device receiving the cutting tool to be machined is movable relative to the grinding device, holding device and grinding device being arranged so as to be movable relative to one another with respect to at least three degrees of freedom. This embodiment makes it possible to position the effective surface of the grinding device in any position relative to the cutting tool to be machined. As a result, any cutting tool geometry can be formed using the apparatus according to the invention, in particular the blade sides of the cutting tool can be machined, whereby the formation of convex, concave, prism-shaped leaf sides and the like is possible. The imagination knows no limits. Also, the leaf sides can be provided with a visible edge, which technically takes over the function of a reinforcing rib or bead. This can also produce relatively thin-ground blades that have a high bending moment or Torsionsflächenmoment thanks to the reinforcing rib or bead so that the cutting tools are bending or torsionally rigid despite their relatively thin blade geometry.

The holding device of the device according to the invention is designed according to a special feature of the invention as a cylinder, preferably in the manner of a drum cylinder. The outer surface of the cylinder carries several Retaining elements for the preferred inclusion of several cutting tools to be machined.

The holding device is rotatably formed, wherein in the case of the embodiment of the holding device as a cylinder, a rotational movement of the holding device about the longitudinal axis of the cylinder is possible. During a rotational movement of the holding device, the cutting tools are guided past the Wirkoberfiäche the grinding device.

The grinding device is formed according to a further feature of the invention as an annular cylinder, wherein the outer surface of the ring forms the provided with an abrasive active surface of the grinding device. The grinding device is designed to be translationally movable in a direction transverse to the axis of rotation, so that an arbitrary point of the blade surface of the cutting tool can be approached in superposition with the movement of the holding device.

According to a further feature of the invention it is provided that either the cutting tool or the grinding device can be tilted about the respective axis of rotation. Thus, skew alignments between the leaf side of the cutting tool to be processed on the one hand and the effective surface of the grinding device on the other hand can be adjusted. This makes it possible to form different blade widths in the longitudinal direction of the cutting tool in a particularly simple manner.

According to the invention, the device has a computer unit for controlling the rotational and translatory movement movements of the holding device and / or grinding device. The entire grinding process can therefore be carried out fully computer-controlled computerized.

The device according to the invention proves to be advantageous over the prior art, in particular because grinding of the cutting tool can be carried out in a comparatively short time. Compared to the prior art can be achieved with the inventive device grinding processing shortening of up to 50%. In order to the device according to the invention proves to be much more effective than the devices known from the prior art.

Another advantage of the device according to the invention is the fact that the preferably designed as an annular cylinder grinding device can be driven with vegleichsweiser high speed. Due to this fact, the knitting surface of the grinding device may be provided with an abrasive of fine grain size. As a result, the cutting tool to be machined can be finished in only one process step with the device according to the invention. Post-processing, for example in the form of a plumb, can be completely eliminated. Thus, a process implementation using the device according to the invention also proves to be extremely cost-effective.

Further features and advantages of the invention will become apparent from the description with reference to the following figures. Showing:

Figure 1 is a schematic top view of the blade of a knife.

FIG. 2 is a schematic side view of the blade of a blade according to FIG. 1; FIG.

3 is a schematic diagram of the device according to the invention according to a first alternative;

3a shows a schematic representation of the device according to the invention according to a second alternative;

Fig. 4 is a schematic detail view of Fig. 3;

5 is a sectional view of the knife blade according to section line V-V of FIG. 2.

Fig. 6 is a sectional view of the knife blade according to section line Vl-Vl of FIG. 2; 7 is a sectional view of the knife blade according to section line VII-VII of FIG. 2;

8 shows the exemplary illustration of a blade cross-section according to a first embodiment;

9 shows the exemplary illustration of a blade cross-section according to a second embodiment;

10 shows the exemplary embodiment of a blade cross-section according to a third embodiment;

11 shows the exemplary embodiment of a blade cross-section according to a fourth embodiment;

12a shows the exemplary embodiment of a blade cross-section according to a fifth embodiment;

FIG. 12 b, in a modification of FIG. 12 a, shows the exemplary embodiment of a blade cross-section according to a fifth embodiment;

13 is an exemplary representation of an apparatus for carrying out the method according to the invention in a first embodiment and

14 shows an exemplary representation of an apparatus for carrying out the method according to the invention in a second embodiment.

The method according to the invention and the device according to the invention are described by way of example with reference to the following FIGS. 1 to 14. The description is not limiting and is only for the better understanding of the invention. Like parts are shown in FIGS. provided with the same reference numerals. Fig. 1 shows a schematic representation of the top in a partial section a ^' knife 1. To recognize the knife blade 2 and the adjoining thereto in the longitudinal direction of the knife handle, not shown in the figure crop 3. Formed are the sheet 2 and the crop 3 made of a steel, for example an alloyed steel.

Fig. 2 shows the knife 1 shown in Fig. 1 from above in a side view. The knife blade 2 and the crop 3 following it in the longitudinal direction 19 can also be seen here. As can be seen from FIG. 2, the blade tip is 4, the blade back is 7 and the blade, that is the burr, 8 designated.

For the final grinding of both the left and the right leaf side is used in the Fign. 3 and 3a in two alternative embodiments schematically illustrated device.

Like the Fign. 3 and 3a, the device is formed from a holding device 11 for receiving the knives 1 to be processed on the one hand and a grinding device 12 on the other hand. According to the embodiment of FIG. 3, the holding device 11 is formed as a cylinder body having on its outer surface in FIG. 3, not shown holding elements for the arrangement of the knife 1. The holding device 11 is rotatably mounted and is rotationally driven in the direction of rotation 15 in the course of grinding. The holding device 11 can also be arranged to be translationally movable in the direction of movement 13.

The grinding device 12 is designed in the manner of a conically tapering cylinder, as can be seen in particular in FIG. 4. The length of the grinding device 12 in the longitudinal direction 19 is formed corresponding to the length of the blade 2 to be processed of the blade 1, as also FIG. 4 can be removed. The grinding device 12 is rotatably arranged as well as the holding device 11, wherein the grinding device 12 in the direction of rotation 16 and the holding device 11 are driven in the direction of rotation 15. In this case, holding device 11 and grinding device 12 rotate in the same direction, so that they are in opposite directions in the contact area. The grinding device 12 is also In the direction of movement 14 arranged translationally movable and can be moved in translation in the direction of the holding device 11 or from this away depending on the desired geometry to be formed sheet geometry. The front side, that is, the outer peripheral side carries the cylindrical grinding device 12 an unspecified in the figure abrasive. The provided with the abrasive outer surface of the grinding device 12 thus represents the effective surface of the grinding device 12.

The method according to the invention for grinding is carried out as described below:

The knives 1 to be processed are clamped in the holding device 11 for the purpose of processing the first side of the sheet 2, using the retaining elements 11 correspondingly formed holding elements. Then holding device 11 and grinding device 12 are set in rotary motion. The holding device 11 is moved up to the grinding device 12 with the knives 1 arranged thereon. A contact between knife 1 and grinder 12 is not given at this time.

As a result of the rotational movement of the holding device 11, the knife 1 arranged thereon are guided past the grinding device 12 with its sheet side to be processed on a circular path. For the purpose of grinding, the grinding device 12 is now brought into line contact with the sheet sides of the knife 1 to be processed, for which purpose the grinding device 12 is moved in the direction of the holding device 11 in accordance with the direction of movement 14. Due to the rotational movement of the holding device 11, the knives 1 to be processed are first brought into contact with the grinding device 12 in the region of their later wate. While the sheet pages to be processed are guided past the grinding device 12 as a result of the rotational movement of the holding device 11, it is moved in the direction of movement 14 by the holding device 11 in a translatory manner. As a result of this movement of the grinder 12, the blade 2 is provided with a geometry as exemplified in FIGS. 8 to 12b is shown. As an alternative to the above-described method implementation, it may also be provided that the grinding device 12 is additionally moved in the height direction 23.

According to an alternative device variant, which is shown in Fig. 3a, the holding device 11 is not rotatable about an axis of rotation 22, but formed in the height direction 25 and in the feed direction 27 transiently movable. For the purpose of translational movement in the feed direction 27, the holding device 11 has an infeed axis 26 and for the purpose of adjustment in the vertical direction 25 via a corresponding vertical axis 24.

The knife 1 carried by the holding device 11, as already described above with reference to FIG. 3, moves past the grinding device 12 on a circular path. However, in contrast to the embodiment according to FIG. 3, this circular movement of the knife 1 does not result from the fact that the holding device 11 itself rotates about an axis of rotation, but rather by an overlapping of the translatory movement of the holding device 11 in the vertical direction 25 and feed direction 27 These two translational movements a model performed by the knife 1 circular motion is modeled, so that adjusts the previously described grinding result in an advantageous manner. Advantage of the device alternative according to Fig. 3a is that the holding device 11 receiving machine parts can be made much stiffer in a simple manner. In this respect, a method implementation with a device according to the method variant according to FIG. 3a is to be preferred. Decisive but also in the variant of Fig. 3a alone is that a movement of grinding device 12 on the one hand and holding device 1 1 on the other hand carried out such that the grinding device 12 and the blade to be machined 1 are brought into line contact.

The particular advantage of the method lies in the fact that the blade geometry can be formed almost arbitrarily, because this results solely by the selected feed movement and the diameter of the grinding device 12 in the direction of movement 14. The closer the grinding device 12 as part of the process to be processed Knife is introduced, the more material is removed. In addition, over the Advance movement of the grinding device 12, the subsequent blade geometry are determined accurately, and so, for example, continuously extending leaf sides, as shown for example in FIGS. 8 and 9, are formed. Also, prismatic blade geometries can be created, as shown for example in FIGS. 10 and 11 are shown. Asymmetrical blade cross sections, such as for right and left handers, can also be formed, as shown in FIGS. 12a and 12b show.

Unlike the prior art, according to the inventive method, the leaf sides to be processed and the grinding device are brought into line contact only substantially. A full-surface processing of the sheet 2 does not take place. From the Fign. 3 and 3a it can be seen that due to the movable arrangement of the holding device 11, the sheet side to be processed and the grinding device are first brought in line in the area of the later Wate 8 of the sheet 2 in line contact. In the further process step, the holding device 11 is guided past the grinding device, as a result of which the line contact between the sheet side and the grinding device travels downwards in the direction of the sheet back. In superposition of these movements, the grinding device 12, as described above, moved in the direction of movement 14 translational. As a result of this movement overlay, the later material thickness of the blade 2 of the blade 1 can be adjusted as desired, over the entire extent of the sheet in the transverse direction.

Fig. 4 shows the schematic representation of FIG. 3 in sections in a view from above. Shown here is a knife blade 2 and the cutter blade 2 sibling grinding device 12. The grinding device 12 rotates about the rotation axis 21, whereas the sheet 2 rotates about the axis defined by the holding device 1 1 rotation axis 22. For better clarity, the knife blade 2 and the grinding device 12 are shown spaced apart in Fig. 4. In the course of the procedure, the knife blade 2 and the grinding device 12 are in line contact, as previously described with reference to FIG.

The grinding device 12 is designed as a tapered cylinder, whereby automatically a sheet geometry with tapering in the direction of the blade tip Cross section results. The cylinder outer surface 18 of the grinder 12 is provided with abrasives of appropriate grain size. Since the grinding device 12 is only in line contact with the sheet 2 to be processed, the outer diameter of the grinding device 12 can be made correspondingly small. This allows a comparatively high rotational speed of the grinding device 12. Due to the comparatively high rotational speed of the grinding device 12, the abrasives arranged on the outer surface 18 can be particles of very small size. In only one procedure, the knife blade 2 can be ground and tapped. A two-stage processing, that is, first grinding and then pleating, is not required in an advantageous manner.

If one side of the sheet 2 has been finished in accordance with the procedure described above, then the knives 1 are to be re-clamped for the purpose of processing the other side of the sheet. In the manner described above, the second side of the sheet 2 is then processed.

The Fign. FIGS. 8 to 12a show possible blade geometries by way of example. The Fign. 8 and 9 show a substantially continuous blade geometry. Starting at the thinly ground Wate 8, the course of the blade geometry in the direction of the sheet back is essentially spherical. The dashed line

10 indicates the initial geometry of the untreated sheet 2.

The Fign. FIGS. 10 and 11 show a difference from FIGS. 8 and 9 not continuously formed sheet contour. The marked in the Fign. 10 and

11 drawn sheet contour by a visible as a visible edge 9 projection. This projection serves as a reinforcing rib or bead and stiffens the sheet 2 against bending or torsional moments. The formation of an edge 9 permitted by the method according to the invention makes it possible to provide relatively thin sheets 2 which, however, are not susceptible to bending or torsional stresses due to their stiffening caused by the edge 9. In the Fign. FIGS. 12a and 12b show a variant of FIG. 8 in which an asymmetric cut has been applied. Here, the benefits of a straight cut are combined with the increased bending moment on the other side. Fig. 2 shows a schematic side view of the formation of an edge 9, as shown in the Querschnittsdarsteliung according to FIGS. 10 or 11 can be seen. As can be seen from Fig. 2, the edge 9 may be formed over the entire length of the sheet 2 in the longitudinal direction 19.

The Fign. 5 to 7 show cross-sectional views corresponding to the section lines V, VI and VII of FIG. 2. It can be clearly seen from these cross-sectional representations that the mate ha I strength of the sheet 2 in the direction of the crop 3 increases. This blade geometry can be adjusted as desired with the method according to the invention as a function of the translational movement of the grinding device 12.

With the method according to the invention, asymmetrically designed blade geometries can also be produced in a simple manner, as shown by way of example in FIGS. 12a and 12 shown. Asymmetrically designed grinding geometries are used, for example, the formation of knives for left or right handed.

Advantageously, the method according to the invention also makes it possible to process the transition between the sheet side on the one hand and the sheet backs 7 on the other hand. This can be bevelled, for example, as shown in FIGS. 10 to 11, or rounded as shown in FIGS. 8 and 9 shown, are formed. An additional processing of the transition between the leaf side and leaf spine is in any case not required after completion of the grinding process according to the invention.

Also, using the method according to the invention in a procedural train, the transition between sheet 2 and crop 3 can be processed. This transition may, for example, as shown in FIGS. 1 and 4 can be seen, be formed in the form of a rounding 20.

The grinding device 12 wears off due to wear as part of the process implementation. Nevertheless, in order to always be able to achieve consistent and reproducible grinding results, the wear-related wear of the grinding device 12 must be compensated. This is achieved according to the invention in that the grinding device 12 as a function of occurring Wear symptoms trained and / or adjusted in the direction of movement 14. Adjusting movement and feed movement of the grinding device 12 are superimposed to a total movement to be made, which is automatically set computer-assisted. In order to detect the adjustment movement to be set to compensate for the wear-related wear of the grinding device, corresponding sensors are provided, so that the method according to the invention can be operated fully automatically.

13 shows a device 28 according to the invention in a first embodiment. It has a workpiece unit 45, a tool unit 46 and an operating unit 47, which will be described in more detail below.

The workpiece unit 45 comprises the holding device 11, which in turn carries the cutting tool 1 to be processed or the cutting tools 1 to be processed. The holding device 11 is designed as a drum cylinder and receives the cutting tools 1 to be machined on the outside surface side.

The holding device 1 1 is coupled to a drive unit 38, which is designed for example as a motor. The drive unit 38 rotatably drives the holding device 11 in the direction of the movement 39 about the axis of rotation 38.

The holding device 11 and the associated rotary drive 38 are flanged to a machine block 36. This machine frame 36 is supported by a machine bed and can be moved translationally in the direction of movement 41. The machine frame 36 is translatable about its vertical axis in the direction of movement 40 and can be moved by the angle γ. Since the holding device 11 is flanged to the machine frame 36, the movement of the machine frame 36 transmits to the holding device 1 1, so that this total both rotationally and translationally, as described above, can be moved.

The tool unit 46 substantially comprises the grinding device 12. This is formed substantially annular, wherein the ring outer surface carries as the active surface 29, the abrasive. The grinding device 12 is around the Rotary axis 32 rotatably disposed, wherein for driving the grinding device 12, a drive unit 31 is provided in the form of preferably a motor.

The grinding device 12 can also be moved translationally, in the direction of movement 30, which is transverse, preferably orthogonal to the axis of rotation 32.

The tool unit 46 further comprises a dressing tool 33. This dressing tool 33, like the grinding device 12, is of annular design and can be rotated around the rotation axis 35 by means of a drive unit 34. If necessary, the outer surface of the annular dressing tool can be brought into contact with the kneading surface 29 of the grinding device 12 for dressing the grinding device 12, for which purpose the grinding device 12 can be moved up to the dressing tool 33 in the direction of movement 30.

As a third unit, the device 28 includes the control unit 47. This consists essentially of a electronic components receiving the control cabinet 42. This cabinet 42 is provided with a control panel 44 through which the entire device 28 can be computer controlled. In terms of communication technology, the electrical cabinet 42 is connected both to the workpiece unit 45 and to the tool unit 46 via corresponding cable connections which are guided in a cable channel 43.

An alternative embodiment of the device according to the invention is shown in FIG. 14. In contrast to the embodiment according to FIG. 13, the holding device 11 is not itself rotatable by the axis of rotation 38 shown in FIG. Thus, the device 28 according to the embodiment of FIG. 14 allows the processing of only one cutting tool. An advantage of the embodiment according to FIG. 14, however, is that the workpiece unit 45 can be made much stiffer due to the lacking rotational movement of the holding device 11 than the workpiece unit 45 according to FIG. 13. Thus, the device according to the exemplary embodiment according to FIG as advantageous if conditioned by lack of machine rigidity under certain circumstances Deviations in the grinding result must be avoided. Otherwise, the device according to FIG. 14 corresponds to that according to FIG. 13.

Both according to the embodiment of FIG. 13 and according to the embodiment of FIG. 14, the grinder 12 may be formed as a grindstone, as a belt grinder or the like.

C o m p a n c ia l e s t e s

1 knife 28 device

2 sheets 29 active surface

3 crop 30 direction of movement

4 ^■ Blade tip 31 Drive unit

7 leaves move 32 rotation axis

8 Waiting 33 Dressing tool

9 longitudinal edge 34 drive unit

10 Initial geometry 35 Rotation axis

11 holding device 36 machine block

12 grinding device 37 rotation axis

13 Direction of movement 38 Drive unit

14 Direction of movement 39 Movement

15 Direction of rotation 40 Direction of movement

16 Direction of rotation 41 Direction of movement

17 Line contact 42 Control cabinet

18 Cylinder outer surface 43 Cable duct

19 Longitudinal direction 44 Control panel

20 Rounding 45 Workpiece unit

21 rotation axis 46 tool unit

22 Rotary axis 47 Control unit

23 height direction

24 vertical axis holding device

25 height direction

26 infeed axis holding device

27 delivery direction

α angle ß angle

Y angle

Claims

claims:

A method of grinding a cutting tool, in particular a knife, in which the cutting tool is brought into contact with the working surface of a grinding device, wherein the cutting tool and the grinding device are moved in at least three degrees of freedom relative to each other.

2. The method according to claim 1, characterized in that the grinding device is moved rotationally and / or translationally.

3. The method according to claim 1 or 2, characterized in that the cutting tool is moved rotationally and / or translationally.

4. The method according to any one of claims 1 to 3, characterized in that the loop end geometry of the cutting tool is generated by the superposition of the rotational and / or translational movement of the grinding device and the rotational and / or translational movement of the cutting tool.

5. The method according to any one of the preceding claims, characterized in that the grinding device is rotatory and translationally moved in at least one direction transverse to the axis of rotation.

6. The method according to any one of the preceding claims, characterized in that the cutting tool is rotationally and translationally moved at least in a direction transverse to the axis of rotation.

7. The method according to any one of the preceding claims, characterized in that the cutting tool is moved translationally in a lying perpendicular to the surface normal of the effective surface of the grinding device direction.

8. The method according to any one of the preceding claims, characterized in that the cutting tool is rotatably moved about a rotational axis lying parallel to the axis of rotation of the grinding device.

9. The method according to any one of the preceding claims, characterized in that the cutting tool and the grinding device are driven in the same direction with respect to their respective rotational movement.

10. The method according to any one of the preceding claims, characterized in that the cutting tool is driven to oscillate with respect to its translational and / or rotational movement with a predetermined frequency.

11. The method according to any one of the preceding claims, characterized in that the grinding device is driven to oscillate with respect to its translational and / or rotational movement with a predetermined frequency.

12. The method according to any one of the preceding claims, characterized in that the grinding device is driven in terms of their rotational movement with a higher speed compared to the rotational movement of the cutting tools.

13. The method according to any one of the preceding claims, characterized in that the grinding device is driven with respect to its rotational movement with a predetermined rotational speed.

14. The method according to any one of the preceding claims, characterized in that the cutting tool is driven with respect to its rotational movement with a predetermined rotational speed.

15. The method according to any one of the preceding claims, characterized in that the rotational speed of the grinding device and / or the rotational speed of the cutting tool in the course of the procedure is optionally set.

16. The method according to any one of the preceding claims, characterized in that the blade of the cutting tool is processed.

17. The method according to any one of the preceding claims, characterized in that in a first grinding operation, the one sheet side and in a second grinding machining the other sheet side of the cutting tool is finished in one go.

18. The method according to any one of the preceding claims, characterized in that the transition region between the leaf side and crop processed, preferably rounded.

19. The method according to any one of the preceding claims, characterized in that the transition region between the leaf side and leaf spines edited, preferably rounded.

20. The method according to any one of the preceding claims, wherein the clamped in a holding device cutting tool with one of its leaf sides to be machined past the effective surface of a rotatably mounted grinding device, wherein the active surface of the grinding device with the blade side of the cutting tool to be machined in substantially line contact brought and the grinding device is moved transversely to its axis of rotation as a function of the sheet geometry to be generated.

21. The method according to claim 20, characterized in that the holding device is rotatable and the cutting tool is guided past on at least one part-circular path on the active surface of the Schieifeinrichtung.

22. The method according to claims 20 or 21, characterized in that the knitting surface of the grinding device is brought in the longitudinal direction of the blade side of the cutting tool to be machined with this over the entire length substantially in line contact.

23. The method according to claim 20, characterized in that the holding device is arranged translationally movable in at least two transverse directions and the cutting tool is guided in a superposition of these two directions of movement of the knitting surface of the grinding device.

24. The method according to claim 20, characterized in that the cutting tool is guided past in a superposition of the two translational directions of movement on at least one part-circular path on the effective surface of the grinding device.

25. The method according to any one of the preceding claims, characterized in that the wear-related wear of Wirkoberfiäche the grinding device is compensated by a translational adjusting movement of the grinding device transversely to its axis of rotation.

26. The method according to any one of the preceding claims, characterized in that the holding device together with the clamped cutting tool is moved up to the grinding device at the beginning of grinding.

27. An apparatus for grinding a cutting tool, in particular a knife, with a holding device for receiving the cutting tool to be machined and a grinding device, wherein the holding device and the grinding device are arranged relative to each other at least three degrees of freedom movable.

28. The apparatus according to claim 27, characterized in that the holding device is rotatable.

29. The apparatus of claim 27 or 28, characterized in that the holding device is designed to be translationally movable.

30. Device according to one of claims 27 to 29, characterized in that the holding device is designed to be translationally movable in two mutually transverse directions.

31. Device according to one of claims 27 to 30, characterized in that the holding device is formed translationally movable longitudinally and transversely to its axis of rotation.

32. Device according to one of claims 27 to 31, characterized in that the holding device is cylindrical.

33. Apparatus according to claim 32, characterized in that the holding device has on its outer cylindrical surface a plurality of holding elements for simultaneously receiving a plurality of cutting tools.

34. Device according to one of claims 27 to 33, characterized in that the holding device has a longitudinal extent, which exceeds the longitudinal extension of a cutting tool received by the holding device.

35. Device according to one of claims 27 to 34, characterized in that the grinding device is rotatable.

36. Device according to one of claims 27 to 35, characterized in that the grinding device is formed transversely movable transversely to its axis of rotation.

37. Device according to one of claims 27 to 36, characterized in that the grinding device is designed in the manner of a ring, wherein the outer surface of the ring forms the provided with an abrasive Wirkoberfiäche the Schieifeinrichtung.