WO2010057706A1

WO2010057706A1 - Drilling tool for drilling and/or cutting device

Info

Publication number: WO2010057706A1
Application number: PCT/EP2009/062383
Authority: WO
Inventors: Helmut Duscha; Peter Keller-Sornig; Rainer Widmann; Massimo Anghileri; Hans-Peter Fuessl; Michalis Stefanopulos; Peter Schwaller; Wilhelm Eckert
Original assignee: Robert Bosch Gmbh
Priority date: 2008-11-24
Filing date: 2009-09-24
Publication date: 2010-05-27
Also published as: CN102223976A; EP2481505B1; EP2367654A1; EP2481505A1; ES2386113T3; RU2525950C2; CN102223976B; DE102008043998A1; EP2367654B1; RU2011125542A

Abstract

The invention relates to a drilling tool (1), in particular for drilling and/or cutting devices, for drilling in brickwork, concrete, stone and the like, comprising a drill head (5) and at least one cutting member (6), wherein the cutting member (6) is located at a free end (7) of the drill head (5), wherein a blade tip (34) of the cutting member (6) protrudes axially beyond the drill head (5) on the drilling direction side in the direction of a longitudinal axis (Ll) of the drilling tool (1) and wherein the cutting member (6) extends radially beyond the drill head (5), wherein the first cutting member (6) comprises at least two blades (16, 19) with blade edges (22, 23), wherein the blades (16, 19) extend radially outward from the blade tip (34), and wherein lateral surfaces (20, 21) that connect blade edges (22, 23) of the first cutting member (6), as seen in the direction of the longitudinal axis (Ll) of the drilling tool (1), between the blade tip (34) and the side surfaces (14, 15; 17, 18) comprise at least one section (B22, B23) having a curved profile that brakes a motion of drill cuttings directed radially outward.

Description

description

title

DRILLING TOOL FOR DRILLING AND / OR CHISEL EQUIPMENT

State of the art

EP 0 846 835 B1 discloses a concrete or rock drilling tool with helical discharge grooves, in which the cutting plate has reinforcements extending at the two radial end regions against the helical outlet of the discharge grooves. Although such rock drilling tools have a higher load capacity due to an increased use of material, comprehensive optimization, in particular also with regard to destruction performance, friction and material consumption, is not achieved with such rock drilling tools.

Disclosure of the invention

The object of the invention is to propose a drilling tool in which the cutting body also has an increased load capacity compared to a conventional cutting body with approximately the same hard metal volume, by which the maximum possible load or the service life is significantly increased.

According to the invention this object is achieved by a drilling tool having the features stated in the characterizing part of claim 1.

According to the invention, the cutting edges between the cutting tip and lateral surfaces, which connect the side surfaces, in each case at least one section with an arcuate, a - viewed in the longitudinal direction of the drilling tool - radial movement of the cuttings braking or inhibiting course. As a result, an improved entrainment of the cuttings around the axis of rotation is achieved. This leads to an improved removal of the drill cuttings via the drill head into the discharge groove or the removal grooves and thus to a reduction of accumulations of drill cuttings between the borehole wall and the drilling tool. This improved Supplying the cuttings in the discharge groove or the Abfuhrnuten leads overall to a reduction in the friction losses, in particular between the cutter body and the borehole wall, as less cuttings between the borehole wall and the drilling tool must be crushed. Thus, the service life of the drilling tool increases, since a wear process is minimized, by which the

Diameter of the cutter body is reduced.

In particular, the invention provides to form this arcuate portion of the cutting edge, as a concave-shaped cutting edge, which moves like a sickle in the direction of rotation of the drilling tool, wherein the observation takes place in the direction of the longitudinal extension of the drilling tool. With such a crescent-shaped course of the cutting edges or the clamping surfaces lying in the direction of rotation in front of the cutting edges, it is possible to retain cuttings in the annular impact field which surrounds the inner impact field processed by the tip until it is transported away by the discharge groove or removal grooves. Through this

Shaping the cutting edges, a radially outward directed flow of the material removed by the drilling tool is braked.

The invention further provides a cutting edge having an arcuate portion which extends over at least 50% of a nominal radius of the cutter body and in particular begins in or at a tip of the cutter body.

Alternatively, the invention provides a cutting edge in which the arcuate portion begins where the tip angle of the cutting tip of the cutting body changes abruptly and in particular decreases suddenly. In the two aforementioned embodiments of the cutting edge, an effect of the design according to the invention is ensured in an annular region around the longitudinal axis of the drilling tool. As a result, the drilling tool has a comparatively large effect.

The invention provides for the arcuate portion of the cutting edge to end there, where the cutting edge merges into the lateral surface of the cutting body. This makes it possible to exploit the positive properties of a curved cutting edge even in the outermost edge region and to obtain a drilling tool with particularly low friction losses.

Alternatively, the invention provides to guide the arcuate portion of the cutting edge to a defined by the shaft or the drill head circumference. In this way, a drilling tool is achieved whose cutting body is particularly robust in radially outer corner regions of the rake surfaces.

The invention provides to make the arcuate portion with a radius or more juxtaposed radii, wherein all radii are larger than one

Nominal radius of the cutting body. By such a dimensioning of the arcuate portion too much retention of cuttings is avoided.

According to the invention, the drilling tool has a first cutting body, in which each cutting edge of the cutting body, in the direction of the longitudinal extension of the

Drilling viewed across the width of the cutter body has a thickness which increases with increasing the radial distance from the cutting tip of a minimum thickness to a maximum thickness, wherein an increase in material in the direction of rotation of the drilling tool takes place before the cutting edge or on both sides of the cutting edge. As a result, the cutting body at each cutting edge with increasing radial

Distance from its longitudinal axis to an increasing volume, which allows for the rotational movement better absorption of the radially outwardly increasing separation forces. Finally, this special shaping of the cutting body allows more material to be destroyed with the drilling tool during striking in an annular impact field arranged around the cutting tip than with a conventionally shaped cutting body of comparable volume. A possibly reduced because of the shape of the separating body in a circular inner impact field destructive power is economically compensated in this area by an increased material removal by rotation, since a relatively small torque is sufficient for a rotary abrasion in the inner impact field.

According to the invention thus creates a drilling tool with a cutting body geometry, which is optimized for the concentric to the longitudinal axis changing loads and requirements and allows this individual adjustment of individual areas a higher maximum load of the drilling tool. For this purpose, the separating body in comparison to a conventional separating body in areas in which the load is above an average load, formed massive and this is the cutting body in areas where the load is below an average load, formed filigree.

Furthermore, the invention provides, side surfaces of the sheaths, with which the respective cutting edge is embedded in the drill head to arrange at an acute angle to each other, wherein planes in which the side surfaces lie, intersect in a cutting line, which the cutting body in the region passes through the opposite edge. By such a design, the different requirements, which arise with increasing radial distance from the longitudinal axis, usually meet relatively well.

The invention also provides side surfaces of the two cutting edges of the first

Cutting bodies, which pass into rake surfaces, to arrange in parallel planes or to arrange side surfaces of the two cutting edges, which pass into open spaces, in parallel planes. In this way, in particular provided in the drill head slot for receiving the cutting body by a simple machining operation, for example, with a grinding wheel produced.

The invention provides to form the cutting body as a cutting plate, which can be fastened in a slot formed in the drill head. Such a drilling tool can be produced as a result of optimizing the cutting body with a comparatively small amount of hard metal.

Alternatively, the invention provides for the cutting body to be formed as a solid carbide head, which can be placed on the drill head, in particular, in such a way that it can be put in place or positively connected to it. In comparison with conventional solid carbide heads, only a comparatively small amount of cemented carbide is required in order to achieve optimum work results or a good service life.

Furthermore, the invention provides to equip the drilling tool with a second and in particular a third cutting body, which are arranged in particular opposite and are formed as a minor cutting body, which are arranged at a distance from the first separating body on the drill head and wherein the secondary cutting body in each case only one Have cutting edge. By means of such secondary cutting bodies, it is possible, in particular for drilling tools with a nominal diameter of the first cutting body of more than 15 mm, to increase the drilling capacity.

Finally, the invention provides for the cutting edge of the secondary cutting body, viewed in the direction of the longitudinal axis of the drilling tool, to be formed as a cutting edge with side surfaces diverging in the radial direction, with an increase in material in the direction of rotation in front of a cutting edge or on both sides of the cutting edge. As a result, advantages can be achieved on the secondary cutting edges, which are comparable to the advantages achieved on the first cutting insert. In a preferred embodiment, the drilling tool according to the invention has a shank with at least one helical discharge groove, whereby a removal of the drill cuttings is advantageously favored.

In a further preferred embodiment, the inventive

Drill a Einsteckende, by which it can be formed as an advantageous replacement tool.

Further details of the invention are described in the drawing with reference to schematically illustrated embodiments.

Hereby shows:

FIG. 1a, 1b: schematic representations of two drilling tools;

Figure 2 to 4: a plan view of a first, second and third embodiment of a drilling tool;

FIGS. 5a to 5c show three partial views of a fourth embodiment of a drilling tool;

Figures 6a to 6c: three partial views of a fifth embodiment of a drilling tool;

Figure 7: a plan view of a sixth embodiment of a

drilling tool;

FIG. 8a: a schematic representation of a cutting body according to the invention and FIG

FIG. 8b: a schematic representation of a cutting body according to the prior art.

In Fig. 1 a, a schematically illustrated drilling tool 1 is shown in side view. The drilling tool 1 comprises a spigot 2, which is referred to as a so-called. SDS

Einsteckende is formed, a shaft 3, with Abfuhrnuten 4, a drill head 5 and a cutting body 6. The cutting body 6 is arranged at a free end 7 of the drill head 5 and designed as a cutting plate 8, which in a slot. 9 of the drill head 5 is attached.

Fig. 1 b also shows a schematically illustrated drilling tool 1 in side view. Also in this drilling tool 1 is followed by a shank 2, a shaft 3, which has helical Abfuhrnuten 4 and ends in a drill head 5, which a

Cutting body 6 carries. In contrast to the drilling tool shown in Fig. 1a, the cutting body 6 is designed as a solid carbide head 10, which rests predominantly flat on a free end 7 of the drill head 5 and is additionally embedded with a pin 1 1 in a recess 12.

The drilling tools 1 shown in FIGS. 1 a and 1 b each have a longitudinal axis L1.

FIG. 2 shows a first embodiment of a drilling tool 1, the basic structure of which corresponds to the drilling tool shown in FIG. 1a. In the

Top view, which is oriented in the direction of the longitudinal axis L1 of the drilling tool 1, a cutting body 6 with an hourglass-like contour 13 can be seen which essentially by side surfaces 14, 15 of a first blade 16, side surfaces 17, 18 of a second blade 19 and lateral surfaces 20, 21 is formed. The cutting edges 16, 19, which together form the cutting body 6, have transversely to their radial

Extension over a drill head 5 thicknesses D, which increase with increasing radial distance R1, R2 from a minimum thickness D1 to a maximum thickness D2. The cutting edges 16, 19 are divided by cutting edges 22, 23 in plan view in each case into a first part body I and a second part body Il, wherein the first part body I under clamping surfaces 24 and 25 and the second part body Il under open spaces 26 and

27 lie. The considerations are made assuming that the drilling tool 1 rotates leftward in a rotational direction w about the longitudinal axis L1 when drilling. By the side surfaces 14, 15 and 17, 18 of the cutting 16, 19 levels E1 to E4 are defined in each case, which intersect in respective opposite cutting edge 19 and 16 at an acute angle α, wherein a cutting line 28, the respective opposite cutting edge 19th or 16 passes through. Furthermore, the clamping surfaces 24, 25 associated side surfaces 14, 18 extending in planes E1 and E4, which are parallel to each other. Likewise, side surfaces 15, 17 which are assigned to the free surfaces 26, 27 extend in parallel planes E2, E3. The lateral surfaces 20, 21, which connect the side surfaces 14, 15 and 17, 18, have at least one

Section with a curved course, which corresponds to a nominal radius RN of the cutting body 6 and the drilling tool 1. Compared to a conventional, in plan view in the direction of a drill longitudinal axis substantially Rectangular cutting body, the drilling tool 1 according to the invention at its cutting body 6 with increasing radial distance from the longitudinal axis L1 and a cutting tip 34 on both sides of the cutting edges 22, 23 an increase in material. By this increase in material on the one hand, a larger-scale action of working as impact surfaces rake surfaces 24, 25 is achieved on the material to be destroyed and on the other hand, the cutting edges 22, 23 better supported in particular to a perimeter U5 of the drill head 5 out.

FIG. 3 shows a second embodiment variant of a drilling tool 1, the basic construction of which corresponds to the drilling tool shown in FIG. 1 a, wherein the drilling tool 1 is shown in plan view in the direction of a longitudinal axis L 1. In principle, in the drilling tool 1 shown in FIG. 3, reference is first made to the description of FIG. 2, wherein a contour 13 of the cutting body 6 and a profile of cutting edges 22, 23 are chosen in contrast to the embodiment shown in FIG is that with increasing radial

Distance from the longitudinal axis L1 exclusively in a lying in the direction of rotation w in front of the cutting edges 22, 23 first part bodies I an increase in material takes place. Such a configured drilling tool 1 is optimized in particular for a high fragmentation performance. Furthermore, the drilling tool 1 shown in FIG. 3 differs from the drilling tool shown in FIG. 2 by a second cutting body 29 and a third cutting body 30, which are formed as secondary cutting bodies 31, each having only one cutting edge S31 and in a drill head 5 spaced apart from the first cutting body 6 are arranged. Analogous to the first cutting body 6, the secondary cutting bodies 31 have a plan view in the direction of the longitudinal axis L1 transverse to their radial extent

Thickness d, which increases with increasing radial distance from the longitudinal axis L1 from a minimum thickness d1 to a maximum thickness d2. Like the first cutting body 6, the secondary cutting bodies 31 are also divided by their cutting edges 32, 33 into first and second body parts III, IV, whereby due to the course of the cutting edge 32 or 33 with increasing radial distance from the longitudinal axis L1 in front of and behind the cutting edges 22 and 33, an increase in material takes place.

FIG. 4 shows a third embodiment variant of a drilling tool 1, which corresponds to the first embodiment variant shown in FIG. 2 with respect to the design of a first cutting body 6. Furthermore, the third one

Embodiment as well as the second embodiment shown in FIG. 3 secondary cutting edges 31 on. Cutting edges 22, 23 of the cutting edges 16, 19 of the first cutting body 6 are in the direction of a longitudinal axis L1 of the drilling tool 1 viewed concavely and jump back against an imaginary, radially extending cutting edge opposite to the direction of rotation. Cutting edges 32, 33 of the minor cutting edges 31 also have, viewed in the direction of the longitudinal axis L1 of the drilling tool 1, such a curvature. All four sickle-like cutting edges 22, 23, 32, 33 have radii R22, R23, R32, R33 which are larger than a nominal radius RN of the cutting body 6.

FIGS. 5a to 5c show a fourth embodiment variant of a drilling tool 1 in two perspective partial views and in a plan view in the direction of a longitudinal axis L1 of the drilling tool 1. A cutting body 6 is as

Cutting plate 8 is formed, which is held in a slot 9 of a drill head 5. The cutting body 6 has a tip 34. The cutting body 34 with the cutting tip 34 designed as a centering tip has no cross-cutting edge and thus allows a better centering during tapping. An arcuate section B22 or B23 of a cutting edge 22 or 23 begins in one of the side views, as shown in FIGS 5a and 5b, viewed below the cutting tip 34 in particular at points P1, P2, in which a point angle ß changes abruptly. The arcuate sections B22, B23 end approximately at a defined by the drill head 5 perimeter U5. As a result, the cutting body 6 is held particularly stable and solid, in particular in corner regions 36, 37 of its clamping surfaces 24, 25.

In FIGS. 6a to 6c, a fifth embodiment of a drilling tool 1 is shown in analogy to FIGS. 5a to 5c. In contrast to the fourth embodiment, the fifth embodiment has a second and a third cutting body 29, 30, which are formed as a secondary cutting body 31. The secondary cutting bodies 31 are opposite and arranged in each case by about 90 ° degrees to a first cutting body 6. Just like the first cutting body 6, the second and third cutting bodies 29, 30 protrude in the axial direction along a longitudinal axis L1 of the drilling tool 1 via a drill head 5, wherein the first cutting body 6 projects the second and third cutting bodies 29, 30 in an arrow direction x a peak 34 surmounted by a height H, which is at least one third of a nominal radius RN of the first cutting body 6.

FIG. 7 shows a sixth embodiment of a drilling tool 1, the basic construction of which corresponds to the drilling tool shown in FIG. 1 b. In this embodiment, a cutting body 6 is designed as a solid carbide head 10, which largely flat on a free end 7 of a drill head. 5 the drilling tool 1 rests and is additionally embedded with a pin 1 1 in a recess 12 in the drill head 5.

In FIGS. 8a and 8b, a cutting body 6 according to the invention and a cutting body 100, which is known from the prior art and is rectangular in plan view, are each compared in plan view. In FIG. 8a, circular arcs 38 are used to indicate a circular ring 39 arranged concentrically with respect to a longitudinal axis L1. This circular ring 39 is taken over as a circular ring 101 corresponding to FIG. 8b. A comparison of the shaded areas F1 and F100 shown in FIGS. 8a and 8b now shows how an area or a volume of the cutting body 6 according to the invention increases with increasing radial distance R, R1 or R2 from the longitudinal axis L1 with respect to that in FIG. 8b, although the two cutting bodies 1, 100 have comparable total areas G6, G100 in plan view. If also the gable-shaped design of the cutting body 6 or 100 is taken into consideration, results in in

Top view of equal total areas G6, G100 a smaller volume V6 of the cutting body 6 according to the invention over a volume V100 of the cutter body 100, since the cutting body 6 is thicker there, where it is low in the direction of the longitudinal axis L1 considered and since the cutting body 6 is narrower there, where it is high in the direction of the longitudinal axis L1 considered.

The invention is not limited to illustrated or described embodiments. Rather, it includes developments of the invention within the scope of the patent claims.

Claims

claims

1. drilling tool (1) in particular for drilling and / or chiseling devices for drilling in masonry, concrete, rock and the like. Comprising a drill head (5) and - at least one cutting body (6),

- wherein the cutting body (6) at a free end (7) of the drill head (5) is arranged,

- Wherein the cutting body (6) with a cutting tip (34) the drill head (5) borehrichtungsseitig axially in the direction of a longitudinal axis (L1) of the drilling tool (1) surmounted and

- wherein the cutting body (6) projects radially beyond the drill head (5),

- wherein the first cutting body (6) comprises at least two cutting edges (16, 19) with cutting edges (22, 23),

- wherein the cutting edges (16, 19) extend radially outwards from the cutting tip (34), characterized in that cutting edges (22, 23) of the first cutting body (6), in the direction of the longitudinal axis (L1) of the drilling tool (1) seen, between the cutting tip (34) and the side surfaces (14, 15; 17, 18) connecting lateral surfaces (20, 21) at least a portion (B22, B23) having an arcuate, a radially outward movement of cuttings braking course ,

2. Drilling tool according to claim 1, characterized in that the arcuate portion (B22, B23) of the cutting edge (22, 23), viewed in the direction of the longitudinal axis (L1) of the drilling tool (1) is concavely curved and counter to the direction of rotation (w ) of the drilling tool (1) springs back.

3. Drilling tool according to claim 1 or 2, characterized in that the arcuate portion (B22, B23) of the cutting edge (22, 23) extends over at least 50% of a nominal radius (RN) of the cutting body (6) and in particular in or on a Tip (34) of the cutting body (6) begins.

4. Drilling tool according to one of claims 1 to 3, characterized in that the arcuate portion (B22, B23) of the cutting edge (22, 23), there begins where the point angle (ß) of the tip (34) of the cutting body (6 ) changed abruptly and in particular reduced by leaps and bounds.

5. Drilling tool according to claims 1 to 4, characterized in that the arcuate portion (B22, B23) of the cutting edge (22, 23) ends where the cutting edge (22, 23) in the lateral surface (20, 21) of the cutting body (6) passes.

6. Drilling tool according to claims 1 to 5, characterized in that the arcuate portion (B22, B23) of the cutting edge (22, 23) ends where the cutting edge (22, 23), in the direction of the longitudinal axis (L1) of the drilling tool (1), reaches a circumference (U5) defined by the shank (3) or the drill head (5).

7. Drilling tool according to claim 1, characterized in that the arcuate section (B22, B23) has a radius (R22, R23) or a plurality of aligned radii, which are larger than a nominal radius (RN) of the Cutting body (6).

8. Drilling tool according to one of the preceding claims, characterized in that each cutting edge (16, 19) of the first cutting body (6), viewed in the direction of the longitudinal axis (L1) of the drilling tool (1), transverse to its radial course a thickness (D ), which with increasing radial

Distance from the longitudinal axis (L1) of a minimum thickness (D1) to a maximum thickness (D2) increases, wherein an increase in material in the direction of rotation (w) in front of the cutting edge (22, 23) or on both sides of the cutting edge (22, 23).

9. Drilling tool according to one of the preceding claims, characterized in that side surfaces (14, 15, 17, 18) of the sheaths (16, 19) with which the respective cutting edge (16, 19) in the drill head (5) is embedded or touching the drill head (5), respectively defining planes (E1-E4) which, viewed in the direction of the longitudinal axis (L1) of the drilling tool (1), are at an acute angle (α) to each other and in particular separate in a cutting line (28), which passes through the separating body (6) in the respective opposite cutting edge (19, 16).

10. Drilling tool according to one of the preceding claims, characterized in that side surfaces (14, 15, 17, 18) of the two cutting edges (16, 19) of the first cutting body (6), which in clamping surfaces (24, 25) pass in parallel Layers (E1, E4) lie.

1 1. Drilling tool according to one of the preceding claims, characterized in that side surfaces (14, 15, 17, 18) of the two cutting edges (16, 19) of the first cutting body (6), which in open spaces (26, 27) merge in parallel planes (E2, E3) lie

12. Drilling tool according to one of the preceding claims, characterized in that the cutting body (6) as a cutting plate (8) is formed, which in a in the drill head (5) formed slot (9) can be fastened.

13. Drilling tool according to one of the preceding claims, characterized in that the cutting body (6) as solid carbide head (10) is formed, which on the drill head (5) can be fastened.

14. Drilling tool according to one of the preceding claims, characterized in that the drilling tool (1) has a second cutting body (29) and in particular a second and a third cutting body (29, 30), wherein the second and the third cutting body (29, 30) are in particular opposite each other and wherein the one or more cutting bodies (29, 30) are in particular formed as a secondary cutting body (31), which are arranged at a distance from the first separating body (6) and which each only one

Cutting edge (S31) have.

15. Drilling tool according to claim 14, characterized in that the cutting edge (S31) of the secondary cutting body (31), viewed in the direction of the longitudinal axis (L1) of the drilling tool (1), transversely to its radial extent has a thickness (d), which with Increasing radial distance from the longitudinal axis (L1) of the drilling tool (1) from a minimum thickness (d1) to a maximum thickness (d2) increases, in particular an increase in material in the direction of rotation (w) in front of a cutting edge (32, 33) or on both sides of Cutting edge (32, 33) takes place.