Metal Drill

Abstract

A metal drill includes a cutting section and a drive section pointing away therefrom. The metal drill has at least two different functional coatings are provided which are designed at least in regions and are designed to permit machining of a metallic workpiece adapted to a respective application material. The drive section has, at least in sections, a polygonal, preferably hexagonal cross-sectional geometry.

Claims

1. A metal drill comprising: a cutting section; a drive section directed away from the cutting section, the drive section having, in at least one section, a polygonal cross-sectional geometry; and at least two different functional coatings formed at least in regions, the at least two functional coatings being configured to permit machining of a metallic workpiece in a manner adapted to a respective application material.

2. The metal drill according to claim 1, wherein the at least two functional coatings are designed to increase a surface hardness of the metal drill.

3. The metal drill according to claim 1, wherein a first functional coating of the at least two functional coatings is formed with titanium nitride and a second functional coating of the at least two functional coatings is formed with aluminum titanium nitride.

4. The metal drill according to claim 1, wherein the cutting section has a cutting head with two cutting edges and a guide section is arranged between the cutting section and the drive section.

5. The metal drill according to claim 4, wherein the cutting section has two helical flutes.

6. The metal drill according to claim 4, wherein the metal drill has an approximately constant diameter at least in a region of the cutting head and the cutting section.

7. The metal drill according to claim 4, wherein the cutting head is configured as a cone shell ground or a surface ground.

8. The metal drill according to claim 1, wherein the metal drill is formed of a high-speed steel.

9. The metal drill according to claim 1, wherein the drive section and the cutting section are roll-rolled, forged, and/or at least partially machined from solid.

10. The metal drill according to claim 1, further comprising a unique marking identifying a metallic workpiece the metal drill is configured to machine.

11. The metal drill according to claim 1, wherein the at least one section of the drive section has a hexagonal cross-sectional geometry.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The disclosure is explained in further detail in the following description with reference to exemplary embodiments shown in the drawings. Shown are:

[0027] FIG. 1 a side view of a metal drill,

[0028] FIG. 2 an enlarged side and top view of the cutting head of the metal drill of FIG. 1, with a cone shell ground,

[0029] FIG. 3 an enlarged side and top view of the metal drill of FIG. 1, with a surface ground, and

[0030] FIG. 4 a schematic view of a drilling system with four metal drills, each with two different coatings, and an optional uncoated metal drill for use on various metallic workpieces.

DETAILED DESCRIPTION

[0031] FIG. 1 shows a metal drill 100 having a cutting section 120 and a drive section 140 directed axially away therefrom. These are preferably designed to be rotationally symmetrical with respect to a longitudinal central axis 110.

[0032] The cutting section 120 has a cutting head 122 with a (drill) tip S, the cutting head 122 being adjoined by a flute section 132 pointing in the direction of the drive section 140 and having, by way of example, two flutes 128, 130 spirally coiled around one another. Illustratively, the cutting head 122 has two cutting edges 124, 126 oriented radially outwardly from the tip S for machining a hole 168 in a metallic workpiece 170 formed with an application material 172.

[0033] The flute 128 has a ground guide chamfer 152 and the flute 130 has a corresponding ground guide chamfer 154.

[0034] A cylindrical guide section 146 extends between the cutting section 120 and the drive section 140. This is preferably also designed to be rotationally symmetrical to the longitudinal center axis 110. At least in the region of the cutting head 122 and the cutting section 120, the metal drill 100 preferably has an approximately constant diameter D.sub.1, which here essentially corresponds to a diameter D.sub.2 of the guide section 146. The guide section 146, together with the drive section 140, forms a shaft section 160 of the metal drill 100.

[0035] The drive section 140 of the metal drill 100 has, at least in sections, a polygonal cross-sectional geometry 142 that is merely hexagonal by way of example here. This preferably has two axial sections A.sub.1,2, between which a fillet-like annular groove 142 extends. In principle, the drive section 140 can have any regular or irregular polygonal cross-sectional geometry that provides a form-fit connection with a tool holding of a tool that rotationally drives the metal drill 100, such as a hand drill or a pillar drill.

[0036] In the region of the cutting section 120 of the metal drill 100, a first functional coating F.sub.1 and a second functional coating F.sub.2 are provided, wherein the functional coatings F.sub.1,2 butt against each other here only exemplarily, forming a first boundary line 148. Illustratively, the first functional coating F.sub.1 extends from the tip S of the metal drill 100 to the boundary line 148 over an axial length L.sub.1, while the second functional coating F.sub.2 extends from the boundary line 148 to a second boundary line 150 and has an axial length of L.sub.2. The second boundary line 150 is between the cutting section 120 and the shaft section 160 of the metal drill 100, which is uncoated in this example. Both boundary lines 148, 150 have the form of a circular line here as an example. The sum of the axial lengths L.sub.1,2 of the functional coatings F.sub.1,2 corresponds here only by way of example to an overall length L of the cutting section 120, but may also deviate from the overall length.

[0037] The length L.sub.1 of the first functional coating F.sub.1 is preferably smaller than the length L, so that there always remains an axial circumferential area, albeit a small one, for forming the second functional coating F.sub.2 with the axial length L.sub.2. In addition, the shaft section 160 may also be provided with the first and/or the second functional coating F.sub.1,2, as appropriate. Among other things, this can reduce any wear in the region of the guide section 146 of the metal drill 100 when making deep holes in the metallic workpiece 170. The boundary lines 148, 150 can have a course deviating from the circular line shape and, for example, be rectangular, triangular, or sinusoidal, so that the functional coatings F.sub.1,2 are interlocked with one another, in particular in the region of the first boundary line 148, or engage in one another in the manner of interlocking without overlapping. Nevertheless, an overlapping formation of the functional coatings F.sub.1,2 is possible.

[0038] In principle, the at least two functional coatings F.sub.1,2 can be designed in any pattern on the metal drill 100. For example, a pattern in the form of continuous or interrupted axial longitudinal stripes running essentially parallel to the longitudinal center axis 110 is conceivable, with the functional coatings F.sub.1 and F.sub.2 alternating on the circumferential side in each case. As a result, the different physical properties of the functional coatings F.sub.1,2 can be used in close spatial proximity. Accordingly, for example, a spiral formation of the functional coatings F.sub.1,2 analogous to the course of the flutes 128, 130 of the metal drill is also possible.

[0039] The functional coatings F.sub.1,2 are preferably designed to increase the surface hardness of the metal drill 100 in a region near the surface of the cutting section 120 of the metal drill 100, but may also have friction-reducing or other functions. The first functional coating F.sub.1 can be realized with titanium nitride, for example, and the second functional coating F.sub.2 can be realized with aluminum titanium nitride, for example, wherein the aluminum titanium nitride can be provided with additives. Other possible material combinations for forming the first and second functional coatings F.sub.1,2 include, for example, titanium carbon nitride, titanium aluminum carbon nitride, chromium carbon nitride, zirconium nitride, titanium aluminum nitride, aluminum chromium nitride, aluminum titanium chromium nitride, aluminum titanium nitride-zirconium carbon nitride, tungsten carbide-carbon, aluminum nitrate silicon, and aluminum titanium nitride.

[0040] At least the cutting section 120 of the metal drill 100 is preferably designed with a high-speed steel (HSS). The cutting section 120 and the drive section 140 may be roll-rolled, forged, and/or at least partially machined from solid. The cutting section 120 and the drive section 140 may be integral or joined together in a suitable manner, which may be by friction welding, thermal shrinking, compression molding, or the like.

[0041] Preferably, the metal drill 100 has a unique marking 180 in the region of the guide section 146 that identifies a metallic workpiece 170 to be optimally machined with the present metal drill 100 that is designed with the application material 172. Due to the marking 180, the user can intuitively select a metal drill for machining that is best suited in each case. The marking 180 may comprise geometric area elements, any characters (letters and numbers) and/or graphics, pictograms, and combinations thereof. In the illustration of FIG. 1, the marking 180 is implemented only exemplarily with the four capital letters X. Deviating from the illustration of FIG. 1, the marking can also be implemented in the region of the drive section 140.

[0042] FIG. 2 shows the cutting head 122 of the metal drill 100 of FIG. 1, which is designed here in exemplary rotational symmetry with respect to the longitudinal center axis 110 and is ground illustratively in the manner of the standard cone shell ground 200. As a result, the two cutting edges 124, 126 are formed and a front surface 202 of the cutting head 122 forms an approximately cone-shaped enveloping surface.

[0043] FIG. 3 shows the cutting head 122 of the metal drill 100 of FIG. 1, which here, by way of example, is designed rotationally symmetrical to the longitudinal center axis 110 and, in contrast to the representation of FIG. 2, is ground illustratively in the manner of the so-called surface ground 210. This forms two cutting edges 212, 214. Due to the surface ground 210, two approximately trapezoidal planar surfaces 216, 218 are created, wherein the cutting edge 212 forms a longitudinal side of the planar surface 216 and the cutting edge 214 forms a longitudinal side of the planar surface 218.

[0044] FIG. 4 shows an exemplary drilling system 400, which here merely exemplifies a total of five metal drills 100, 420, 422, 424, 426 that are combined or housed in a storage unit 402 for convenient use by the user. The metal drills 100, 420, 422, 424, 426 each preferably in turn have a hexagonal drive section that is not designated for the sake of a better drawing overview.

[0045] Illustratively, the metal drill 100 has the functional coating F.sub.1 in the region of its cutting head 122 and the functional coating F.sub.2 in the remaining region of the cutting section 120 (see in particular FIG. 1). Deviating therefrom, the metal drill 420 has exemplary functional coatings F.sub.3,4, the metal drill 422 has exemplary functional coatings F5,6, and the metal drill 424 has exemplary functional coatings F.sub.7,8, while the metal drill 426 has exemplary design without coating.

[0046] The area proportions of the functional coatings F.sub.3, . . . , 8 in the region of the cutting sections of the metal drills 420, 422, 424 may differ from those of the metal drill 100 as shown. Each of the coated metal drills 100, 420, 422, 424 preferably has at least two or more functional coatings F.sub.1, . . . , 8 designed at least in some regions, at least in the region of its respective cutting section.

[0047] The functional coatings F.sub.3, . . . , 8, for example, are realized with other chemical compounds or substances compared to the first and second functional coating F.sub.1,2 and consequently have other physical parameters such as (micro-)hardness HV 0.5 according to Vickers, maximum permissible application temperature, coefficient of friction against 100Cr6 steel, or the like. Thus, each of the differently coated metal drills 100, 420, 422, 424 as well as the metal drill 426 without coating is particularly suitable for drilling a metallic workpiece made of a special application material such as steel, iron, cast iron, stainless steel, titanium, aluminum, copper, lead, etc., as well as metal alloys.

[0048] Due to the marking 180 of the metal drill 100 and the corresponding markings 432, 434, 436, 438 of the metal drills 420, 422, 424 as well as 426, an unambiguous selectability of the metal drill 100, 420, 422, 424, 426 best suited for the machining of a given metallic workpiece made of a certain application material by the user for achieving best possible working results is ensured. In order to permit particularly easy and convenient access by the user to the differently coated metal drills 100, 420, 422, 424 as well as the metal drill 426 without coating, these are preferably combined in a storage unit 402 in the form of a hard case 406 shown here only by way of example. In this example, the hard case 406 has a cuboid bottom portion 408 for holding the metal drills 100, 420, 422, 424, 426 and a transparent top portion 410. Instead of the hard case 406, a case-like or pocket-like soft case or other storage unit, such as a revolver magazine-like or cylindrical or cassette-like storage unit, may also be provided.