TOOL HOLDER, AND CHISEL SUPPORT AND DRILLING BIT FOR A DRILL HEAD
A drill head including a tool holder, chisel supports mounted thereon and drill bits. According to this invention, the chisel supports can be separated from the tool holder.
1. Field of the Invention
This invention relates to a tool holder for a drill head with a fastening shank through which a mud channel passes and with a support structure fastened directly or indirectly to the fastening shank.
This invention also relates to a drill bit support for a drill head, with a support head on which a bearing section of a drill bit that can be fastened in rotary fashion.
This invention also relates to a drill bit for rotary attachment to a drill bit support.
2. Discussion of Related Art
Drill heads are used to dig drilling holes in the ground for construction projects. To do so, the drill heads are fastened at one end to a drill pipe. The rotation and the advancing motion of a drive unit are transferred to the drill head by the drill pipe.
For example, horizontal drilling machines are known, which are used to produce a relatively horizontal bore in the ground. This is done to drive the drill head under roads, buildings, or the like. Usually, the drill heads have a tool holder that holds drill bits, which are supported in sockets in rotary fashion. When the drill head is driven through the ground, the drill bits roll against the material to be removed and break it free. This causes it to fragment so that it can be flushed away with a mud emulsion. The mud emulsion is supplied to the drill heads via the drill pipe. The drill heads are subject to wear and thus must be regularly replaced.
SUMMARY OF THE INVENTIONOne object of this invention is to provide a drill bit support and a drill bit, which are designed so that they are optimized with regard to wear.
This object and others of this invention relating to the tool holder are attained if the support structure has tool sockets offset from one another in the circumference direction for accommodating drill bit supports in a replaceable fashion.
According to this invention, there is a wear system in which the tool holder has an interface for the replaceable coupling of the drill bit support. Consequently, the tool holders and the drill bit supports can be replaced independently of one another in accordance with their wear state. This achieves an optimization of the service life of the individual tool components.
According to one embodiment of this invention, it is possible for the tool sockets to be embodied or shaped in the form of insertion sockets. Thus, the drill bit supports can be easily changed and precisely positioned, even in the rough conditions of worksite operations and in installation situations with limited accessibility.
In this connection, it is particularly advantageous if the tool sockets have an insertion opening, which opens in the direction oriented away from the fastening shank or in a radially outward direction. Thus, the drill bit supports can be inserted into the insertion sockets from the front side or the rear side of the drill head. Alternatively, the insertion socket can also be embodied or shaped in the form of a guide projection onto which the drill bit support can be slid.
A tool holder according to this invention can be embodied or formed so that in the region of the tool socket, a fastening receptacle, in particular a screw receptacle, is provided, which opens in the direction toward the fastening shank and is accessible from there. Thus, the screw receptacle is oriented so that the screw head of a fastening screw is inserted into the screw receptacle and is favorably positioned with regard to wear. In particular, it is then not exposed to the abrasive wear action.
A possibility for exact positioning of the drill bit supports is provided in a simple way if the tool sockets have two guide grooves or guides situated on opposite sides from each other.
Thus, a favorable centering is achieved if the guide grooves are laterally delimited by two flanks, which extend in the longitudinal direction of the groove and are oriented at an angle relative to each other. This design is also load-optimized. The wall sections of the tool sockets that form the grooves become thicker in the direction toward the bottom of the groove and thus have a large load cross-section at the location in which the highest loads occur.
Preferably, the tool sockets each at least partially comprises two guide projections and outlet channels formed between the guide projections of adjacent tool sockets. The rock material that is removed with the supplied emulsion can be conveyed away via the outlet channels.
One object of this invention relating to the drill bit support is achieved if an insertion lug is directly or indirectly coupled to the support head of the drill bit support. With this insertion lug, the drill bit support can be inserted into a correspondingly embodied tool socket of the tool holder. It can then be replaced independently of the tool holder, each as a function of its individual wear state. This achieves a wear-optimized design. With its insertion lug, the drill bit support can be quickly and simply attached to the tool holder and detached from it again.
The insertion lug can have guide pieces on two opposing sides. With these guide pieces, it can be inserted, for example, into grooves of the tool holder, in order to thus achieve a reliable and exact positioning.
For a load-optimized design, the guide pieces can have two guide surfaces that are oriented at an angle relative to each other and are connected to each other via a connecting section. The guide pieces widen out starting from their free ends and thus have their maximum cross-section in the region in which they connect to the drill bit support and therefore have a load-optimized design.
In one embodiment of this invention, the insertion lug has a support lug at its free end and this support lug produces an additional stable attachment.
For example, it is also possible for the support lug to transition into the guide pieces in a way that results in an easy-to-produce geometry.
A drill bit support according to this invention can also be embodied so that the insertion lug is delimited by a convex inner surface and/or a convex outer surface. In the region of the convex inner surface, the drill bit support can correlate with a correspondingly concave recess of the tool holder. The matching convex/concave regions in the vicinity of the inner surface produce an interface, which, like a key in a lock, promotes the association of the correct drill bit support with a tool holder. The convex outer surface of the drill bit support reduces the number of possible weak points of the bore wall and thus contributes to a wear-optimized layout of the tool design. The convex shape also achieves a thickening of the insertion lug cross-section and thus a greater stability.
A drill bit support according to this invention can have a support head that supports a bearing section and labyrinth seal parts are positioned or situated in the transition region from the support head to the bearing section. These labyrinth seal parts can be put together with corresponding labyrinth seal parts of a drill bit in order to thus produce a labyrinth seal. This labyrinth seal counteracts the penetration of rock material and thus protects the bearing section and a bearing contained therein.
A drill bit can be simply affixed to a drill bit support so that the bearing section has a circumferential groove for accommodating a clamping element. The clamping element can then be connected to the drill head with form-locking engagement and/or frictional, nonpositive engagement.
In one embodiment according to this invention, the central longitudinal axis formed by the bearing section extends at an angle in the range between 30° and 90° in relation to the outer surface. This achieves an optimization of the bearing pressure on the bearing between the drill bit and the tool support. It is advantageous for this angular range to lie between 50° and 70°. This also produces an outer surface of the drilling tool that is functional and easy to shape.
One object of this invention is also achieved with a drill bit for coupling to a drill bit support in rotary fashion. The drill bit has an outer surface with hard material elements. The drill bit also has a bearing receptacle. In the region of the bearing receptacle, the drill bit according to this invention has labyrinth seal parts, which can be put together with labyrinth seal parts of the drill bit support to form a labyrinth seal. This labyrinth seal counteracts the penetration of rock material, thus using simple means to effectively protect the bearing receptacle from wearing action.
In order to also maintain a reliable position-fixing relative to the drill bit support, even when there are abrupt and uneven loads on the drill bit, it is possible according to this invention for the bearing receptacle to have an end surface that supports a support element of hard material. This support element can cooperate with a counterpart support element or a counterpart surface of the drill bit support.
This invention is explained in greater detail below in view of an exemplary embodiment shown in the drawings, wherein:
Drill bit supports 20 can be mounted in the tool sockets 13. The design of the drill bit support 20 is shown in greater detail in
The insertion lug 21 has a support head 26 with a bearing section 26.3 formed integrally onto it. In the transition region to the bearing section 26.3, the support head 26 has an annular shoulder 26.1 extending around it, which is adjoined by a circumferential groove 26.2. The shoulder 26.1 and the groove 26.2 constitute or form labyrinth seal parts. The cylindrical bearing section 26.1 is first adjoined by a concave transition 26.4 in order to adapt its size to a reduced-diameter connector piece at the end. A circumferential groove 26.5 is incorporated into the connector piece. The bearing section 26.3 terminates at its end with an end surface 26.7. As shown in
As shown in
The tool combination composed of the drill bit support 20 and drill bit 30 can be inserted into a tool socket 13 of the tool holder 10. For this purpose, the insertion lug 21 is slid into the tool socket 13, which is embodied or shaped in the form of an insertion socket. In the process of this, the guide surfaces 22.1 of the guide pieces 22 slide along the flanks 13.3 of the guide grooves 13.2. The insertion movement of the drill bit support 20 is limited by the support surfaces 23.2 that come to rest against corresponding counterpart surfaces of the tool sockets 13. Then the fastening screw 12.2 can be inserted through the screw receptacle 12.1 and screwed into a threaded hole 21.1 of the insertion lug 21.
As shown in
After all three drill bit supports 20 are fastened to the tool holder 10, the drill head is ready for use. During engagement of the tool, the tool holder 10 and with it, the drill bit support 20, rotates around the rotation axis R. As this occurs, the drill bits 30 come into engagement with the material to be removed. Because of the rotating motion, the drill bits 30 roll in the drilling hole and the hard material elements 34 cut into the material to be removed. An emulsion is supplied via the mud channel 15, which is sprayed out in the region of the nozzle 15.1. The emulsion flushes out the removed and crushed material, where the emulsion then flows out via the outlet channels 14.1. The drill bits 30 are designed differently from one another in the region of or near their outer surface 31 so that the rotating rows of hard material elements 34 of one drill bit 30 can travel in a respective groove 32, 33 of the adjacent drill bit 30.
During engagement of the tool, the above-described tool combination experiences wear. Consequently, the drill bit 30, the drill bit support 20, and the tool holder 10 undergo continuous wear. Depending on the wear state, according to this invention, the tool holder 10, the drill bit support 20, and the drill bits 30 can each be individually replaced. For tool replacement, the drill head is detached from the drilling lance. To accomplish this, the screw connection between the fastening shank 11 and the drilling lance is disconnected. The drill bit support 20 can then be detached by simply unscrewing the fastening screw 12.2 from the tool holder 10. The drill bit 30 can be pressed out from the drill bit support 20. In the course of this, the clamping element 29.1, due to the geometry of the grooves 26.5 and 35, is deflected radially inward and thus disengages from the groove 35 of the drill bit 30. The drill bit 30 can then be slid off of the drill bit support 20.
As shown in
As shown in
As shown in
As shown in
The insertion lug 21 supports a tool head 26, which has a bearing section 26.3 integrally formed onto it.
The embodiment of the tool head 26 and drill bit 30 is selected to be similar or essentially identical to that of the embodiment according to
Claims
1. A tool holder (10) for a drill head with a fastening shank (11) having at least one mud channel (15) passing through or associated with the at least one mud channel (15) and having a support structure (12) fastened directly or indirectly to the fastening shank (11), the tool holder (10) comprising the support structure (12) having tool sockets (13) offset from one another in a circumference direction.
2. The tool holder (10) according to claim 1, wherein the tool sockets (13) are formed as insertion sockets.
3. The tool holder (10) according to claim 2, wherein the tool sockets (13) have an insertion opening which opens in a direction oriented away from the fastening shank (11) or in a radially outward direction and/or the tool socket (13) has a protruding guide region (13.1) with guide surfaces.
4. The tool holder (10) according to claim 3, wherein near the tool socket (13) a fastening receptacle (12.1) being a screw receptacle positioned which opens in a direction toward the fastening shank (11) and being accessible from the opening.
5. The tool holder (10) according to claim 4, wherein the tool sockets (13) have guide grooves (13.2) on opposite sides from each other.
6. The tool holder (10) according to claim 5, wherein the guide grooves (13.2) are each delimited by two flanks (13.3) which extend in a longitudinal direction of the groove.
7. The tool holder (10) according to claim 6, wherein the tool sockets (13) each at least partially comprises two guide projections (13.1), and outlet channels (14.1) are formed between the guide projections (13.1) of the adjacent tool sockets (13).
8. A drill bit support (20) for a drill head with a support head (26), on which a drill bit (30) can be fastened to a bearing section (26.3) in a rotary fashion, comprising an insertion lug (21) directly or indirectly coupled to the support head (26).
9. The drill bit support (20) according to claim 8, wherein the insertion lug (21) has guide pieces (22) on two opposite sides.
10. The drill bit support (20) according to claim 9, wherein the guide pieces (22) have two guide surfaces (22.1), and flanks (13.3) oriented at an angle relative to each other and connected to each other by a connecting section (22.2).
11. The drill bit support (20) according to claim 10, wherein the insertion lug (21) has a support lug (23) at a free end.
12. The drill bit support (20) according to claim 11, wherein the support lug (23) transitions into the guide pieces (22).
13. The drill bit support (20) according to claim 12, wherein the insertion lug (21) is delimited by a flat inner surface (24) and/or by a convex outer surface (25).
14. The drill bit support (20) according to claim 13, wherein the support head (26) supports a bearing section (26.3) and labyrinth seal parts are positioned in a transition region from the support head (26) to the bearing section (26.3).
15. The drill bit support (20) according to claim 14, wherein the bearing section (26.3) has a circumferential groove (26.5) for accommodating a clamping element (29.1).
16. The drill bit support (20) according to claim 15, wherein a central longitudinal axis (ML) formed by the bearing section (26.3) is oriented at an angle (a) in a range between 70° and 90° relative to the outer surface (25).
17. The drill bit support (20) according to claim 16, wherein the guide pieces (22) on the insertion lug (21) are asymmetrical relative to the central longitudinal plane (L) extending in the longitudinal direction of the insertion lug.
18. A drill bit (30) for a rotatable coupling to a drill bit support (20), having an outer surface (31) with hard material elements (34) and a bearing receptacle (37), the drill bit (30) comprising: near the bearing receptacle (37), a circumferential groove (38) accommodating a clamping element (29.1) adjustable between two clamping positions.
19. The drill bit (30) according to claim 18, wherein the labyrinth seal parts are positioned near the bearing receptacle (37).
20. The drill bit (30) according to claim 19, wherein the bearing receptacle (37) has an end surface that supports a support element (39) of a hard material.
21. The drill bit (30) according to claim 18 for mounting on a tool support (20) according to claim 8.
22. The tool holder (10) according to claim 1, wherein near the tool socket (13) a fastening receptacle (12.1) being a screw receptacle positioned which opens in a direction toward the fastening shank (11) and being accessible from the opening.
23. The tool holder (10) according to claim 1, wherein the tool sockets (13) have guide grooves (13.2) on opposite sides from each other.
24. The tool holder (10) according to claim 1, wherein the tool sockets (13) each at least partially comprises two guide projections (13.1), and outlet channels (14.1) are formed between the guide projections (13.1) of the adjacent tool sockets (13).
25. The drill bit support (20) according to claim 8, wherein the insertion lug (21) has a support lug (23) at a free end.
26. The drill bit support (20) according to claim 8, wherein the insertion lug (21) is delimited by a flat inner surface (24) and/or by a convex outer surface (25).
27. The drill bit support (20) according to claim 8, wherein the support head (26) supports a bearing section (26.3) and labyrinth seal parts are positioned in a transition region from the support head (26) to the bearing section (26.3).
28. The drill bit support (20) according to claim 8, wherein the bearing section (26.3) has a circumferential groove (26.5) for accommodating a clamping element (29.1).
29. The drill bit support (20) according to claim 13, wherein a central longitudinal axis (ML) formed by the bearing section (26.3) is oriented at an angle (a) in a range between 70° and 90° relative to the outer surface (25).
30. The drill bit support (20) according to claim 8, wherein the guide pieces (22) on the insertion lug (21) are asymmetrical relative to the central longitudinal plane (L) extending in the longitudinal direction of the insertion lug.
31. The drill bit (30) according to claim 18, wherein the bearing receptacle (37) has an end surface that supports a support element (39) of a hard material.
Type: Application
Filed: Jun 28, 2012
Publication Date: Aug 7, 2014
Inventors: Karl Kammerer (Fluorn-Winzeln), Wolfgang Essig (Rosenfeld)
Application Number: 14/131,640
International Classification: E21B 10/20 (20060101); E21B 10/22 (20060101);