EP2283953B1 - Cutting blade and method for its production - Google Patents

Description

The present invention relates to a method for manufacturing a plurality of cutting blades for machines for slicing food products, in particular for high-performance slicers.

High-performance slicers are used to cut up food products, such as ham, sausage or cheese, with a high cutting rate. The cutting blades used for this purpose are exposed to high loads during operation, which is why there is a correspondingly increased wear. Depending on the product, therefore, a relatively frequent replacement of the respective cutting blade on the associated cutting device may be necessary, which is disadvantageous in terms of effectiveness.

The publication US 2007/0237589 A1 discloses a cutting blade for use in slicers for slicing food having a cavity inside. The US 2006/0090603 A1 and the US 2008/0250656 A1 reveal knives for the kitchen and leisure sector, for the production of which a hot isostatic pressing process is used. The publication JP 11-106801 discloses a method of making cutting tools using a hot isostatic pressing process.

The object of the invention is to simplify the production of cutting blades.

This object is achieved by a method for producing a plurality of cutting blades having the features of claim 1. According to the invention a, in particular cylindrical, stacking arrangement is provided from a plurality of basic bodies, a coating layer is applied by a hot isostatic pressing process on the stack assembly, in particular on a lateral surface of the stack assembly, and the stack assembly is separated to obtain a plurality of individual substrates with application layer. Through the use of such a stack arrangement, the manufacturing costs can be reduced because not every cutting blade is individually subjected to the energy-intensive HIP process.

The application layer of each basic body can be processed to produce a cutting area. In particular, grinding, milling or machining processes can be carried out.

A cutting blade produced according to the invention may have at least one working area, which is transferred both from an initial state to a finished state by means of a hot isostatic pressing process and also connected to a base body of the cutting blade and / or to another working area.

Thus, a working range of the cutting blade can be defined, which e.g. is exposed during operation to a special load. This working area of the cutting blade can be made of a special material which is optimized with regard to the special stress. By a hot isostatic pressing process (HIP process) is achieved on the one hand, that the work area is transferred from an initial state to a finished state. On the other hand, the connection between the working area and the adjacent blade areas is based on a hot isostatic press connection. Such a compound is particularly strong and durable, since the various areas merge into one another under the conditions of hot isostatic pressing at the interfaces, so that a similar connection is formed as in diffusion bonding. It can be provided in this way a cutting blade with stress-appropriate range division. For example, a single work area may be connected to a main body of the cutting blade. Alternatively, several different work areas can be provided. In certain applications, it may also be advantageous to provide no basic body, but only different work areas.

The working area can form a cutting area of the cutting blade, which in particular defines a radially outwardly pointing cutting edge of the cutting blade. This area is subjected to a particularly high load during cutting, so that it is advantageous to manufacture it from a special material, which has a finished state based on a HIP process. By limiting the use of the special material to the immediate cutting area, any associated higher costs can be minimized.

Alternatively, the working area may form a receiving or fastening area of the cutting blade. On the mounting area are usually special requirements to make, as this, for example, must absorb relatively high clamping forces. It may therefore be favorable to manufacture the fastening region from a special material which has a finished state based on a HIP process. Depending on the specification, both the cutting area and the receiving or fastening area of the cutting blade can be provided as a working area.

In the cutting blade, at least one working area may consist of a powder metallurgical steel. By using powder metallurgical steel (PM steel), the hardness and wear resistance of the work area can be increased. Powder metallurgy steels are lighter and can be produced with better dimensional tolerances than conventional steels, so that the use of powder metallurgy steel results in a good cost-benefit effect. In particular, workpieces with relatively complex shape can be easily manufactured. The formation of a workspace made of a powder metallurgy steel can thus provide a cutting blade of any desired shape with increased wear resistance, without using special steels that are difficult to process for this purpose. By limiting the use of powder metallurgy steel as a material to the work area, the increased cost associated with PM technology in combination with the HIP process can be minimized.

A main body of the cutting blade may consist of a non-powder metallurgical material. The main body, which depending on the application a considerable part of

Cutting knife forms, so it can be made in a simple and cost-effective manner as existing cutting blades. In particular, the base may be forged, cast or rolled steel.

The main body is preferably made of a material that does not undergo any significant change in properties in a subsequent to the hot isostatic pressing process curing process. This means that the main body behaves largely neutral during the hardening process to be carried out after the HIP process, so that curing of the HIP-based work areas does not lead to any fear of impairment of the non-HIP-based main body.

The main body of the cutting blade may be formed as a plate or disc.

The working region forming a cutting region of the cutting blade can be applied in particular to an outer peripheral region of a base body of the cutting blade. In the knife manufacture, therefore, the base body is first produced in a known manner, and in a subsequent processing step, a cutting region - e.g. made of powder metallurgical steel - applied.

The working region forming a cutting region of the cutting blade can be formed at least partially annularly, in particular partially annularly, and / or in the form of a closed ring. In a circular knife, such a cutting region thus extends continuously around the blade axis in a continuous manner. With a sickle knife In particular, the cutting area can extend along a spiral-shaped partial ring.

Between the work area and a base body and / or between several work areas with each other, a flush transition can be provided. A flush transition facilitates cutting and avoids hygienic problems that could be caused by edges, grooves or protrusions.

The cutting blade can be designed as, in particular both rotating and planetary encircling circular blade or as, in particular rotating, sickle, spiral or Cuttermesser. Since the work area is e.g. is applied in a subsequent processing step on a previously provided base body, no major changes in manufacturing are necessary for the production of a cutting blade.

For producing a cutting blade, a base body can be provided and at least one working area connected to the base body can be produced by means of a hot isostatic pressing process. The main body can also be made of a HIP-based material, so that the HIP process both the base body and the work area are transferred to a finished state and at the same time a firm connection between the body and work area is made. The main body also forms a working area in this case.

Possible developments of the invention are also specified in the dependent claims, the drawings and the description.

Fig. 1

zeigt eine vereinfachte Draufsicht auf ein Schneidmesser.

Fig. 2A

zeigt eine Querschnittsansicht einer Stapelanordnung aus mehreren Grundkörpern, die zum erfindungsgemäßen Herstellen einer Mehrzahl von Schneidmessern bereitgestellt wird.

Fig. 2B

zeigt die Stapelanordnung gemäß Fig. 2A mit einer aufgebrachten Auftragsschicht.

Fig. 3

zeigt eine erfindungsgemäße Anordnung aus mehreren getrennten Grundkörpern mit einer jeweiligen Auftragsschicht.

Fig. 4

zeigt eine Querschnittsansicht eines erfindungsgemäß fertig bearbeiteten Schneidmessers.

The invention will be described below with reference to the drawings.

Fig. 1

shows a simplified plan view of a cutting blade.

Fig. 2A

shows a cross-sectional view of a stacking arrangement of a plurality of basic bodies, which is provided for producing a plurality of cutting blades according to the invention.

Fig. 2B

shows the stack arrangement according to Fig. 2A with an applied coating layer.

Fig. 3

shows an inventive arrangement of several separate basic bodies with a respective application layer.

Fig. 4

shows a cross-sectional view of an inventively finished cutting blade.

According to Fig. 1 For example, a high-performance slicer comprises a cutting blade 11 having a central working area 12, an annular base body 13 and a likewise annular outer working area 14.

The central work area 12 consists of a solid body, which can be converted by means of a HIP process from a fixed initial state to a finished state. The outer working area 14 consists of a powder metallurgical material, which can likewise be converted from a powdery initial state into a finished state by means of a HIP process. The main body 13 is made of conventional rolled steel.

The cutting blade 11 is subjected to a HIP process during production, by means of which both the central working area 12 and the outer working area 14 are brought to a finished state. In particular, the powder metallurgical material of the outer working area 14 is sintered to a solid state. During the HIP process there is also a fixed connection between the central work area 12 and the base body 13 and between the base body 13 and the outer working area 14. In a subsequent processing step the cutting blade 11 is subjected to a hardening process. The main body 13 of the conventional steel undergoes no significant change in its mechanical properties in this hardening process, ie it behaves substantially neutral during curing after hot isostatic pressing.

After curing, the cutting blade 11 can be subjected to further processing steps. In particular, it can be processed in such a way that the circumference of the outer working area 14 forms a cutting edge 21 pointing radially outward. Furthermore, 12 bushings for fastening the cutting blade 11 to an associated blade receptacle of the high-performance slicer can be provided in the central work area. In the finished cutting blade 11, the outer working area 14 thus forms a cutting area, while the central working area 12 forms a receiving or fastening area. The central working area 12 and the outer working area 14 provide in the highly loaded portions of the knife edge and the knife attachment optimized material sections, which contribute significantly to an increase of the machine or blade life.

The cutting blade 11 is in Fig. 1 merely as an example as both a knife axis M rotating and planetary rotating circular knife shown. Alternatively, it could also be designed as a purely rotating sickle, spiral or craft knife. During operation of the associated high-performance slicer, a product is delivered by means of a product feed to the cutting blade 11 so as to cut off product slices from the product and supply them to further processing.

With reference to Fig. 2A, 2B . 3 and 4 Now, a method of manufacturing a plurality of cutting blades 11 will be described. According to Fig. 2A a cylindrical stacking arrangement 23 is provided of a plurality of superposed and each separated by an intermediate layer 25 basic bodies 13 which consist for example of an austenitic Cr-Ni steel (for example, material number 1.4301). The intermediate layers 25 may for example consist of an Al ₂ O ₃ film. The stacked base body 13 are then braced against each other for fixing and to prevent cavitation. The stack assembly 23 is then encapsulated by a sleeve, not shown, wherein between the lateral surface 26 of the stack assembly 23 and the sleeve wall, a cavity is provided, which is filled in a subsequent manufacturing step with a powder metallurgical material. The encapsulated stack assembly 23 is then vibrated to mechanically densify the powder metallurgical material in the cavity and expel any voids present. The sleeve is then sealed tight and subjected to a HIP process. The HIP process sinters the powder metallurgical material in the cavity to a homogeneous, dense solid. The intermediate layers 25 prevent a HIP-related connection of the base body 13 with each other. After completion of the HIP process, the sleeve is opened and the stack assembly 23, which is now a in Fig. 2B has shown application layer 27 is removed. The application layer 27 is initially present in soft-annealed form.

The main body 13 are then separated from each other by the stack assembly 23 is severed at the level of the intermediate layers 25, for example by cutting off. The resulting blanks 29, so the individual base body 13 with respective coating layer 27, which in Fig. 3 can then be used to smooth the surface and the Adjusting a uniform material thickness are ground flat. Depending on the application, surface grinding may be followed by bending, pressing and / or machining. Furthermore, the knife blanks 29 are subjected to a hardening process, preferably a vacuum-based volume heat treatment. The mechanical properties of the base body 13 are not affected in the curing process, since the corresponding steel material behaves largely neutral to the curing. After hardening, the finishing of the knife blanks 29 is carried out by milling and / or grinding, in each case finally a cutting blade 11 having a cutting plane S according to FIG Fig. 4 to obtain, which has a sintered cutting portion 14.

Since in the described method a plurality of base bodies 13 are simultaneously subjected to a HIP process, in particular the energy costs can be reduced.

It should be noted that the main body 13 of the finished cutting blade 11 in FIG Fig. 4 is shown only simplified. Depending on the type of knife, different holes may be provided for attachment purposes or a separate attachment area. Furthermore, the base body 13 for stabilization or stiffening not shown bulges or elevations.

Since powder metallurgy materials are more moldable than conventional steels, the sintered cutting area 14 may also have a relatively complicated geometric shape.

LIST OF REFERENCE NUMBERS

11

cutting blade

12

central workspace

13

body

14

outer work area

21

cutting edge

23

stack assembly

25

liner

26

lateral surface

27

application layer

29

blade blank

M

blade axis

S

cutting plane

Claims (12)

1. A method of manufacturing a plurality of cutting blades for machines for slicing food products, in particular for high-speed slicers,
   characterised by the steps:

   - providing a stack arrangement (23) of a plurality of base bodies (13);

   - applying a deposition layer (27) to the stack arrangement (23) by means of a hot isostaic pressing process; and

   - separating the stacked arrangement (23) in order to obtain a plurality of individual base bodies (13) with a deposition layer (27).
2. A method in accordance with claim 1,
   characterised in that
   the stack arrangement (23) has a cylindrical shape.
3. A method in accordance with claim 1 or claim 2,
   characterised in that
   the application of the deposition layer (27) onto the stack arrangement (23) takes place onto a jacket surface of the stack arrangement.
4. A method in accordance with any one of the preceding claims,
   characterised in that
   a cylindrical stack arrangement is provided of a plurality of base bodies (13) arranged above one another and respectively separated by an intermediate layer (25).
5. A method in accordance with any one of the preceding claims,
   characterised in that
   the deposition layer (27) of each base body (13) is processed for producing a cutting region.
6. A method in accordance with any one of the preceding claims,
   characterised in that
   the deposition layer (27) is applied as a powder metallurgical steel.
7. A method in accordance with any one of the preceding claims,
   characterised in that
   the base bodies (13) each comprise a non-powder metallurgical material.
8. A method in accordance with claim 7,
   characterised in that
   each base body (13) is produced from a material which undergoes substantially no change in properties in a hardening process subsequent to the hot isostatic pressing process.
9. A method in accordance with any one of the preceding claims,
   characterised in that
   the base bodes (13) are each configured as a plate or as a disk.
10. A method in accordance with any one of the preceding claims,
    characterised in that
    the respective deposition layer (27) forming a cutting region of the cutting blade (11) is configured at least as part-ring shaped, in particular as part-circular ring shaped, and/or in the form of a closed ring.
11. A method in accordance with any one of the preceding claims,
    characterised in that
    a flush transition is provided between the deposition layer (27) and each base body (13).
12. A method in accordance with any one of the preceding claims,
    characterised in that
    each cutting blade (11) is configured as a circular blade, in particular both a rotating circular blade and a circular blade revolving in a planetary motion, or as a scythe blade, spiral blade or cutter blade, each in particular rotating.

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