WO2012163897A1

WO2012163897A1 - Drill

Info

Publication number: WO2012163897A1
Application number: PCT/EP2012/060005
Authority: WO
Inventors: Günter Stiebitz; Matthias Mack
Original assignee: Swg Schraubenwerk Gaisbach Gmbh
Priority date: 2011-06-01
Filing date: 2012-05-29
Publication date: 2012-12-06
Also published as: EP2714311A1; DE102011076890A1

Abstract

The invention relates to a drill containing a drill shaft (1), which is produced for example by extrusion and which has a clamp-in section (2) formed at one end of the drill shaft in the form of a hexagon with or without recesses. A separately produced drill head (10) made of hard metal is fastened to the opposite free end face (7) of the drill shaft (1) in such a way that there is a form closure between the drill shaft (1) and the drill head (10) in the rotational direction of the drill. The form closure can be established in different ways. For example, pins (12) that are arranged in grooves (13) of the drill head (10) and that protrude beyond the end side (11) of the drill head (10) facing the drill shaft (1) can be provided, which pins engage in the corresponding grooves (3) of the drill shaft (1).

Description

description

drill

The invention relates to a drill, in particular a twist drill.

Twist drills have a drill shank which has slots for chip removal running obliquely to the longitudinal axis. At the one end of the drill shank a clamping end is formed, which is adapted to the usual tool holders. At the opposite end of the drill shank a drill head is formed, which has drill bits and takes over the actual drilling work.

Classic drills of this type are made of one piece of metal. For rock drills, the insertion of a cutting tip is known.

It is also known to form a drill in two parts, comprising a steel drill stem and a tungsten carbide drill head. The grooves of the drill shank can be made by a machining process or by rolling. At the end of the drill, a clamping end to be machined only is formed (EP 2253401 A1).

It is also known to produce a drill shank with helical grooves by extrusion molding (WO 2010/142458 A 2).

The invention is based on the object to provide a drill that can be produced inexpensively and still delivers good work results. To solve this problem, the invention proposes a drill with the features mentioned in claim 1. Further developments of the invention are the subject of dependent claims. - -

The proposed by the invention drill thus contains a drill shank with grooves. At the one end of this shaft a clamping end is formed. This is produced by a relatively inexpensive process of the drill shank with its clamping end. The drill head, which has a more complicated shape, is manufactured separately and then connected to the end facing away from the chuck end of the drill shank. It takes place in the circumferential direction, d. H. in the direction in which the larger forces occur during drilling, a positive connection. In the axial direction, a frictional connection can be sufficient, since forces occur at most in the compression direction.

Drills having such helical grooves are often referred to as twist drills, although the shape of the grooves is not a spiral shape.

The production of the drill shank with the grooves can be done in different ways, both by machining and by rolling rollers.

The forming and arranging the clamping end can be done by cutting or non-cutting machining.

In a further development of the invention it can be provided that the drill shank has a flat end surface. The initially mentioned positive connection in the direction of rotation can therefore be done at another location. The flat end face of the drill shank and the cooperating planar mating face of the drill head serve to transfer the pressing force required during drilling to the drill head in such a way that it maintains its orientation with respect to the axis of rotation of the drill.

In a further development of the invention can be provided that - - The drill shank has an end portion in which its appearance, its arrangement and / or its cross section with respect to the rest of the drill shank is changed. Preferably, in said end region, the mentioned in the direction of rotation positive locking of the drill head relative to the drill shank.

One way in which the end portion may be formed according to the invention in a further development is that the end portion relative to the rest of the drill shank has a modified shape.

Another possibility proposed by the invention is that although the end section has the same shape as the drill shank in front of the end section, the shape is smaller or differently arranged relative to the drill shank. For example, it is conceivable that the end section has a geometrically similar but reduced cross-sectional shape as the previous part of the drill shank.

It is also possible that the end portion has the same cross-sectional shape, but this is oriented differently. If, for example, the drill shank is coiled, then it is conceivable that the end section is no longer coiled, but extends in a straight line in the axial direction. The spiral grooves pass into the grooves of the end section. There are also provided combinations of these possibilities according to the invention.

It has already been mentioned that drills have grooves, in particular helically arranged grooves, which serve for chip removal. Since the chips are formed on the drill head, preferably the drill head also has such grooves, which merge into the grooves of the drill shank. - -

A possibility proposed by the invention, as a form-fit can be realized in the direction of rotation, is that the drill head has over its parting surface to the drill shank projecting, engaging in grooves of the drill shank projections. If, for example, the drill shank has four helical grooves, or even four grooves arranged in a straight line, the drill head can likewise have four projections which engage in the grooves in the region of the end section of the drill shank. If the grooves in the drill shank are helical, the projections of this helical shape are adapted.

There are also other numbers of grooves or projections possible, preferably between two and six grooves and projections.

A further possibility proposed by the invention for implementing the positive connection in the direction of rotation may be that the drill head is designed as a cap which is placed on the end of the drill shaft. The cap has a cross-sectional shape corresponding to the cross-sectional shape of the end portion of the drill shank, particularly the end portion of the drill shank.

The outer diameter of the drill head may be equal to the outer diameter of the drill shank when the end portion has a smaller cross-section than the drill shank in front of the end portion. Then the cap can bridge this difference.

But it is also conceivable that the outer diameter of the drill head to twice the wall thickness of the cap is greater than the outer diameter of the drill shank. Yet another possibility for positive connection in the direction of rotation may be that the drill on the preferably flat front side of the drill shank a polygonal Zap- - - fen, which engages in a complementarily shaped recess in the drill shaft facing the end face of the drill head.

For example, this pin can have the cross-sectional shape of a regular hexagon.

According to the invention, the drill shank can have between two and six grooves, in particular four grooves and an equal number of ribs.

It has already been mentioned that the drill stem is made of a material that is less hard to allow production by extrusion. The drill shank itself does not contribute to the actual drilling process, which is why a lower hardness is sufficient. According to the invention, however, the drill head may be made of hard metal. The drill head itself is very small in the axial direction of the drill, so that the cost for the production and processing of the drill head in relation to a production of the entire drill bit made of hard metal is low.

The connection, which permanently holds the drill head to the drill shank, can be done by welding, soldering, gluing or the like. The clamping end can according to the invention have a polygonal, in particular hexagonal, cross section. It is also possible that the chucking end has SDS shape.

In development of the invention can be provided that the drill shank is made by extrusion. It is used for this purpose, a material that can be deformed by extrusion. - -

In yet another embodiment of the invention can be provided that the clamping end is formed at the end of the shaft, ie by a process without the formation of chips. Further features, details and advantages of the invention will become apparent from the claims and the abstract, the wording of which is incorporated by reference into the content of the description, the following description of preferred embodiments of the invention and with reference to the drawing. Hereby show:

Figure 1 is a side view of a drill according to the invention with not yet attached drill head;

FIG. 2 is an enlarged view of the upper end of the drill;

Figure 3 perspective, the assignment between the drill head and drilling rschaft; Figure 4 is an end view of the drill;

FIG. 5 is a perspective view of the drill of FIGS. 1 to

4; Figure 6 is a representation corresponding to Figure 1 of a second

embodiment;

Figure 7 is the front view of the drill of Figure 6; Figure 8 shows a section through the drill head of the embodiment according to

Figure 6; , ,

Figure 9 is a representation corresponding to Figure 3;

Figure 10 is a representation corresponding to Figure 5 of the embodiment of Figure 6;

Figure 1 1 is a side view of a drill of a third embodiment;

Figure 12 is a representation corresponding to Figure 2 of the front

end;

Figure 13 is an end view;

Figure 14 is a representation corresponding to Figure 3;

Figure 15 is a perspective view of the drill of Figure 1 1;

Figure 16 is a side view of another embodiment; Figure 17 is an enlarged view of the end of the drill of

Figure 16;

Figure 18 is an end view of the drill; Figure 19 is a perspective view of the connection between

Drill head and drill shank;

Figure 20 is a representation corresponding to Figure 5 and 10 of the embodiment of Figure 16;

Figure 21 is a side view of a drill of another embodiment; - -

FIG. 22 shows the assignment between drill head and drill shank;

Figure 23 is an end view of the end surface of the drill shank;

FIG. 24 is a perspective view of the association between the drill head and the drill collar;

Figure 25 is a perspective view of the drill of Figure 21;

Figure 26 shows one end of the drill shank;

Figure 27 shows another end of a drill shank; Figure 28 is a third end of a drill shank;

Figure 29 is an end of a drill stem according to a fourth embodiment; FIG. 30 shows the end of the drill shank of the embodiment according to FIG. 21.

The drill shown in Figure 1 in a side view shortly before its completion contains a drill shank 1, at its one lower end in Figure 1, a clamping end 2 is formed with a cross section in the form of a regular hexagon. The drill shank comprises four grooves 3 which extend in the form of a right-hand screw over the length of the drill shank 1 until they reach a boundary 4 at which an end region 5 of the drill shank 1 begins. From this boundary 4, the grooves 3 then extend straight, just like the ribs 6, which separate the grooves 3 from each other. The end of the drill shank 1 opposite the chuck end 2 ends in a flat face. - 7.

The drill shank 1 is produced by extrusion. For the clamping end 2 facing away from the working end of the drill a drill head 10 is provided, which is made of hard metal. This drill head 10 has a plane end face 1 1, which is associated with the end face 7 of the drill shank 1 and this is opposite. Laterally, the drill head 10 includes a total of four pin-like projections 12 which are arranged in the grooves 13 of the drill head 10 and projecting beyond the drill shaft 1 facing end face 1 1 of the drill head 12.

Similar to the drill shank 1, the drill head 10 includes ribs 16 and grooves 13 which correspond in their arrangement, shape and size to the grooves 3 and ribs 6 of the drill shank.

The drill is completed by the drill head 10 is pushed onto the drill shank 1 until its end face 1 1 bears against the end face 7 of the drill shank. In this case, the projections 12 of the drill head 10 come to lie in the grooves 3 'of the drill shank 1. By the engagement of the projections 12 in the grooves 3 'of the drill shank 1 creates a positive fixing in the direction of rotation. In the assembled state takes place at the end 14 of the projections 12, a weld between the projections 12 and the drill shank first This is shown at reference numeral 15.

FIG. 4 shows how the projections 12 between which ribs 6 and 16 are arranged. The perspective view of Figure 5 explains the type of composition again. There you can also see the cutting edges of the drill head. - -

In the embodiment of FIGS. 1 to 5, in the end region 5 of the drill shank the cross-sectional shape is the same as in the preceding region of the drill shank, but in the axial direction there is no longer any rotation of the cross-sectional shape. This makes it possible that the projections 12 are formed in a straight line. Their projecting over the end face 1 1 length corresponds to the axial length of the end portion 5. The embodiment shown in Figures 6 to 10, initially differs in that the end portion 5 of the drill shank 1 has a reduced outer diameter. The shape of the end region can best be seen from FIG. 9. The cross-sectional shape corresponds to the cross-sectional shape of the drill shank in front of the end region, with the difference that the cross-sectional shape is geometrically similar but reduced in size. As a result, grooves 3 'and arranged between the grooves ribs 6' are formed. The separation point 4 between the drill shank 1 in front of the end region 5 and the end region 5 itself forms a step.

The drill head 20 has an outer shape which, except for the missing protrusions 12, corresponds to the outer shape of the drill head 10 of the previous embodiment. The drill head 20 thus has ribs 16 and grooves 13 lying between the ribs. A recess 21 extends from the end side facing the drill shank 1 into the drill head 20, the shape of which is complementary to the outer shape of the end region 5 of the drill shank 1. The recess 21 extends deep into the drill head 20. The recess 21 has a flat bottom 22, which corresponds to the end face 7 of the end portion 5 of the drill shank 1. The drill head 20 is placed on the end portion until it rests on the separation point 4 formed as a step. Then also the bottom 22 of the recess 21 of the drill head lies flat on the forehead - - surface 7 of the end 5 on. Then, at the indicated point 25, a welding takes place between the drill shank 1 and the drill head 20. The geometrically similar shape of the end region 5 ensures that the grooves 13 of the drill head 20 merge into the grooves 3 of the drill shank.

In the embodiment shown in FIGS. 1 to 15, there is again a difference in the end region 5. While in the two preceding embodiments the cross-sectional shape continues axially linearly in the end region, the turning of the grooves 3 and the ribs continues 6 continues in reduced end area. Since the drill head 30 is formed as a cap, the ribs 16 and the grooves 13 of the drill head 30 are coiled. Otherwise, the connection is similar to that of the embodiment of FIGS. 6 to 10, i. the drill head 30 is placed as a cap on the end portion 5 until it rests on the formed by the separation point 4 stage. Because of the spiraling of the grooves 3 'and ribs 6' in the end region 5, the placement itself takes place in a screwing motion. Subsequently, a welding or soldering takes place again.

The embodiment of FIGS. 16 and 20 again uses a solid drill head 40 with a flat end face facing the end of the drill shank. In the grooves 13 of the drill head 40, pin-like projections 42 are fastened or arranged, whose projecting over the end face of the drill head 40 parts 44 are angled so that they follow the shape of the grooves 3 of the drill shank. After placing the drill head 40, which also takes place with a small rotational movement, the projections 42 are welded in the region of its end portion with the drill shank 1.

In the embodiment of FIGS. 16 to 20, the grooves 13 and ribs 16 of the drill head 40 are again rectilinear as in the embodiment of FIGS. Of course, it would also be possible for the ribs 16 and grooves 13 to continue the helical shape of the drill shank 1 also in the region of the drill head 40, similar to the embodiment of FIGS. 1 to 15.

Figures 21 to 25 show a fifth embodiment of a drill according to the invention. On the flat end face 7 at the end of the drill shank 1, a pin 51 is formed, which has a hexagonal cross-section. The diameter of the pin is significantly smaller than the diameter of the end face 7. The drill head 50 includes a flat end face 1 1, from which a recess leads into its interior, which is the shape of the pin 51 complementary. After placing the drill head 50 is a weld along the separation point between the two parts.

The following figures 26 to 30 again show different types of the end region of the drill shank on the side to which the drill head is to be attached. The end region 5 of Figure 26 corresponds to the embodiment of Figure 1 to 5. The cross-sectional shape of the end portion 5 is identical to the cross-sectional shape of the drill shank to the separation point 4. However, the orientation of the cross-sectional shape in the axial direction then no longer changes, while the orientation in the preceding Area of the drill shank twisted in the axial direction.

FIG. 27 shows the end of the drill shank 1 of the embodiment according to FIGS. 7 to 10. The cross-sectional shape in the end region 5 is geometrically reduced in a similar manner to the cross-sectional shape in the preceding region of the drill shank. The orientation of the cross-sectional shape no longer changes in the axial direction in the end region, while it is continuously twisted in the axial direction in the preceding region. - -

FIG. 28 shows the end of the drill shaft, as it is formed in the embodiment according to FIG. 16 to FIG. There is virtually no end area in which anything changes in the appearance, orientation, shape, or size of the drill shank 1.

FIG. 29 shows an end region 5 of the drill shank 1 corresponding to the embodiment according to FIGS. 1 to 15. In the end region, the cross-sectional shape is geometrically similar to the previous part of the drill shank 1, and the orientation of the cross-sectional shape also twists in the end region when advancing in the axial direction ,

Finally, FIG. 30 shows the end of the drill shank corresponding to the embodiment according to FIGS. 21 to 25.

Claims

claims

1. drills, in particular spiral drill, with

1.1 a drill shank (1),

1.2 one at the one end of the drill shank (1) arranged clamping end (2),

1.4 a at the clamping end (2) facing away from the end of the drill shank (1) mounted drill head (10, 20, 30, 40, 50), the

1.5 is made separately and

1.6 is positively connected in the direction of rotation of the drill with the drill shank (1).

2. A drill as claimed in claim 1, wherein the drill shank (1) has an end surface (7).

3. Drill according to claim 1 or 2, wherein the drill shank (1) has an end portion (5) with respect to the cross section of the drill shank (1) changed cross section and / or appearance.

4. Drill according to one of the preceding claims, wherein the

Boring head (10, 40) on its parting surface (1 1) to the drill shank (1) projecting, in grooves (3) of the drill shank (1) engaging projections (12, 44).

5. Drill according to one of the preceding claims, wherein the drill head (20, 30) is designed as a cap which is placed on the end of the drill shank (1).

6. Drill according to one of the preceding claims, with a on the end face (7) of the drill shank (1) arranged mehr- angular pin (57) and a complementary recess in the drill shank (1) facing end face (1 1) of the drill head (50).

A drill according to any one of the preceding claims, wherein the drill shank (1) has between two and six grooves (3) and an equal number of ribs (6).

A drill according to any one of the preceding claims, wherein the drill head (10, 20, 30, 40, 50) is made of cemented carbide.

A drill according to any one of the preceding claims, wherein the drill head (10, 20, 30, 40, 50) is connected to the drill shank (1) by welding, soldering, gluing or the like.

Drill according to one of the preceding claims, wherein the clamping end (2) has a polygonal cross-section, in particular as a square or hexagon is formed.

Drill according to one of the preceding claims, in which the drill shank (1) is produced by extrusion, in particular spiral presses.

12. Drill according to one of the preceding claims, wherein the

Clamping end (2) at one end of the drill shank (1) is formed.