Method for tipping a cutter head of an end-milling cutter

[0002] 1. Field of the Invention

[0003] This invention relates to a method for tipping a cutter head of an end-milling cutter with a hard alloy material. This invention also relates to an end-milling cutter for a coal cutting, road cutting or mining machine having a cutter head tipped with a hard alloy material.

[0004] 2. Description of Related Art

[0005] Conventionally, a hard alloy material for end-milling cutters has a sintered material, with components of tungsten, carbide and cobalt. The sintered hard alloy elements can be inserted into a receiver of the cutter head and soldered into it.

[0006] It is one object of this invention to provide a method for tipping a cutter head of an end-milling cutter with a hard alloy material, by which an end-milling cutter is simply produced, with which especially wear-resistant and tough hard alloy materials can be developed.

[0007] It is another object of this invention to provide an end-milling cutter of the type mentioned above but with a tip, made of hard alloy material, distinguished by a high degree of wear-resistance and toughness.

[0008] In accordance with a method of this invention, a hard alloy material in the form of a bulk material is introduced into a receiver of the cutter head, and hollow spaces formed between the particles of hard alloy material are filled, at least partially, with a bonding agent, which links the hard alloy particles. With this type of end-milling cutter manufacture, tipping with a hard alloy material occurs in situ, by means of which a low cost and effective production run is achieved.

[0009] It is also possible by the method of this invention to match the material of the hard alloy particles and the bonding agent to each other. Thus it is possible to establish the toughness of the hard alloy material by the bonding agent, and to establish the wear resistance of the hard alloy material by the hard alloy particles. Depending on the intended use, it is possible to match properties of the material by varying the material of the hard alloy particles and the bonding agent, as well as by varying the proportions of the components.

[0010] In accordance with a preferred embodiment of this invention, a soldering powder is added to the hard alloy material as the bonding agent. The soldering powder is changed into a molten state by means of the action of heat.

[0011] Thus, overall in the molten state the bonding agent developed as a solder is taken up by capillary action into the hollow spaces formed between the hard alloy particles. A very even distribution of the solder can thus be achieved. One prerequisite is that appropriate capillary cross sections are available in the bulk material by means of the surface geometry and/or the size of the hard alloy particles.

[0012] Extremely wear-resistant hard alloy materials can be realized if WC/W₂C mixed carbides are introduced into the receiver of the cutter head as the hard alloy particles. To be able to develop particularly impact-resistant structures, a copper filler material, for example a cupreous manganese solder, is introduced as a bonding agent into the hollow spaces formed between the hard alloy particles.

[0013] An end-milling cutter of this invention can be distinguished by the hard alloy material that has particles of hard alloy melted carbide, which are linked together by a bonding agent. The particles of hard alloy melted carbide have a particularly great wear resistance. WC/W₂C mixed carbides in particular can be used as particles of hard alloy melted carbide. These can be linked to each other by a solder matrix made of cupreous manganese.

[0014] If the proportion of the particles of hard alloy melted carbide in the hard alloy material is 60 to 90%, particularly impact-resistant structures can be produced because of the high proportion of bonding agent.

[0015] The hard alloy material can form a cutter tip of the cutter head and/or a wear-protection element for the cutter head of the end-milling cutter in accordance with this invention.

[0016] This invention is explained in greater detail by preferred embodiments represented in the drawings, wherein:

[0017] FIG. 1 shows a partial sectional side view of a cutter head of a round-shaft cutter with a cutter tip inserted into the cutter head; and

[0018] FIG. 2 shows a partial sectional side view of a cutter head of a round-shaft cutter with a cutter tip inserted and with an additional wear-protection element.

[0019] A cutter head 10 of a round-shaft cutter is shown in FIG. 1. Round-shaft cutters of this type are used to cut floor coverings, in particular road surfaces. The variation represented in FIG. 1 can be used for cutting concrete. A receiver 11 is cut into the cutter head 10. The receiver 11 receives a cutter tip 12. The cutter tip 12 projects with a work section 13 past the cutter head 10. In the present example, the work section is concavely designed. To produce the cutter tip, a bulk material of WC/W₂C mixed carbides is filled into the receiver 11. A hood-shaped cover is placed on the cutter head 10 for shaping the work section 13. Then a cupreous manganese soldering powder is inserted into an inlet opening of the hood-shaped cover and is changed into the molten form by induction. The solder flows into the hollow spaces formed between the WC/W₂C mixed carbides by the action of gravity. Depending on the geometry of the hollow spaces, the penetration of the liquid solder into the structure of the hollow spaces is aided by a capillary effect. It is also possible to mix the solder powder directly with the WC/W₂C mixed carbides in order to achieve an even distribution of the solder. Preferably the proportion of WC/W₂C mixed carbides is 70 to 80% of the material of the cutter tip 12. The remainder is formed by the cupreous manganese solder matrix. This high proportion of the matrix leads to particularly impact-resistant structures with a simultaneously high wear resistance.

[0020] A further embodiment of this invention is shown in FIG. 2. The cutter tip 12 of this round-shaft cutter is not made in situ, as in FIG. 1, but as a separate component. This separate component can be inserted into the receiver 11 of the cutter head 10 and fixed in place, for example by soldering. The cutter tip 12 is also made of WC/W₂C mixed carbides, which are linked to each other by a cupreous manganese soldering matrix.

[0021] The cutter head 10 of this round-shaft cutter is equipped with a wear-protection element 14 in addition to the cutter tip 12. An annular, peripheral receiver 15 is cut, for this purpose, into the cutter head 10. The receiver 15 is also filled with a hard alloy material of WC/W₂C mixed carbides and cupreous manganese. Similar to FIG. 1, the wear-protection element 14 can be made in situ or as a separate element, which is subsequently installed in the receiver 15.