CN111295261B

CN111295261B - Drilling tool

Info

Publication number: CN111295261B
Application number: CN201880071115.6A
Authority: CN
Inventors: H-P·菲斯尔; H·弗吕尔; 裘晓; R·威德曼; A·弗尔茨; S·松塔格
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2017-10-30
Filing date: 2018-10-09
Publication date: 2023-08-15
Anticipated expiration: 2038-10-09
Also published as: WO2019086212A1; DE102017219452A1; CN111295261A

Abstract

The invention relates to a drilling tool extending along a longitudinal axis, comprising a tool head, an attachment region for connecting the drilling tool with a suction device, a shank region arranged between the tool head and the attachment region, at least one transport channel extending along the shank region, wherein the transport channel is formed by grooves, which are arranged radially between a cover element and a shank element, respectively, wherein the shank element has at least one groove located on the outside. It is proposed that the transport channel has a substantially constant cross section.

Description

Drilling tool

Technical Field

Background

DE 10 2011 075769 A1 describes a drill bit with an inner channel which is arranged between the sleeve and the peripheral side of the base body.

Disclosure of Invention

The invention relates to a drilling tool extending along a longitudinal axis, comprising a tool head, an attachment region for connecting the drilling tool with a suction device, a shank region arranged between the tool head and the attachment region, at least one transport channel extending along the shank region, wherein the transport channel is formed by grooves, which are arranged radially between a cover element and a shank element, wherein the shank element has at least one groove located on the outside. It is proposed that the transport channel has a substantially constant cross section. Advantageously, the suction of cuttings in the drill hole can thereby be optimized.

The drilling tool is in particular designed as a rock drill bit, which is provided for a hammer drill. The drilling tool has an insertion end at its end facing away from the drilling tool head, which is designed to be coupled to a hand-held power tool (e.g., a hammer drill). Preferably, the drilling tool is configured in the region of the insertion end in such a way that it can be coupled to a tool receptacle of the hand-held power tool. In the region of the insertion end, the drilling tool can have, for example, form-locking elements embodied as special grooves, which form an SDS-plus interface or an SDS-max interface. In order to machine a workpiece, the drilling tool is brought into a rotating and linearly oscillating or striking state by means of the hammer drill. The drill penetrates into the workpiece in the feed direction of the drill during machining. The feed direction of the drilling tool extends coaxially to the longitudinal axis and extends from the insertion end in the direction of the drilling tool head. The longitudinal axis of the drilling tool corresponds in particular to the working axis or the rotation axis of the drilling tool. In this context, a drill head is to be understood as meaning, in particular, a region of the drill having at least one cutting body. The cutting body has at least one cutting element, which can be configured as a primary cutting element or as a secondary cutting element. The cutting element is composed in particular of a hard metal. Preferably, the hardness of the cutting element is higher than the hardness of the rod element. Each cutting element has at least one cutting edge. The cutting edge corresponds to the intersection of the cutting face and the free face of the cutting element. Preferably, each cutting element has a single cutting edge. Alternatively, the cutting element can also have a plurality of cutting edges which in particular merge into one another. The transport channel is in particular configured for transporting a fluid, in particular a gas flow, in the drilling tool. The transport channel is preferably arranged for sucking away drill cuttings in the drill hole during drilling. The drill cuttings are preferably transported against the feed direction of the drilling tool. The transport passage has a suction inlet and a suction outlet, and the distance between the suction inlet and the suction outlet corresponds to the length of the transport passage. The transport channel is preferably arranged eccentrically with respect to the longitudinal axis. The cuttings can enter the transport path through the suction inlet. Preferably, the drill head comprises at least one suction port. The suction opening and the suction opening can be arranged substantially parallel to each other, in particular substantially perpendicular to each other. In particular, the cutting body has at least two cutting elements, preferably at least three cutting elements, preferably at least four cutting elements. The connection of the cutting body to the drilling tool is achieved in particular by a material-locking connection. Preferably, the drill head is configured as a one-piece hard metal head, wherein the individual cutting bodies with the at least one cutting element are connected to the rod element by means of blunt surfaces, preferably by means of fusion welding. Alternatively, it is also conceivable for the drilling tool to have a cutout, into which the at least one cutting body is inserted and connected, in particular by means of a soldered connection. In this context, welded connections differ from soldered connections in particular in that the components to be connected are partially melted during the fusion connection. The attachment region has, in particular, at least one connecting element which is configured for connecting the drilling tool with a suction adapter. Preferably, the suction adapter is configured in such a way that it can be partially moved in relation to the drilling tool in the connected state. In particular, the suction adapter is supported in such a way that it is substantially immovable in the axial direction on the drilling tool and rotatable around the drilling tool, so that the suction adapter is substantially fixed in the axial direction on the drilling tool and the drilling tool is rotatable within the suction adapter. In particular, the suction adapter is fastened to the drilling tool with play. The suction opening is arranged in particular in the attachment region. Preferably, the transport channel is arranged partly in the attachment area. The rod element is preferably connected to the drill head, in particular to the cutting body, in a material-locking manner. Preferably, the rod element intersects the longitudinal axis of the drilling tool. The rod element in particular bears at least partially, preferably completely, axially against the drill head or against the cutting body. The lever element is in particular designed to transmit an impact impulse from the hand-held power tool to the drill head. The rod element is made of a metallic material, in particular steel.

The cover element is arranged in particular completely within the envelope curve circumscribing the rod element. The cover element can be connected to the rod element in a form-locking and/or force-locking manner or can also be connected to the rod element in a material-locking manner. The cover element can be composed of a metallic material and/or of a plastic-containing material. In particular, the cross-section of the transport channel is substantially constant along at least 90% of the length of the transport channel, preferably along at least 95% of the length of the transport channel. The orientation of the cross section depends on the course of the transport channel. Preferably, the transport channel in the region of the rod extends substantially parallel to the longitudinal axis, thus resulting in an orientation of the cross section perpendicular to the longitudinal axis. Preferably, the frame line of the profile of the transport channel is configured substantially straight between the suction opening and the suction opening. Alternatively, it is also conceivable for the frame line to extend helically, in particular with a constant or varying slope, around the longitudinal axis from the suction opening to the suction opening.

It is further proposed that the cover element protrudes at least partially into the drill head. Advantageously, the suction opening can thereby be arranged closer to the tip. In particular, the cover element projects into the cutting body in such a way that a subsection of the transport channel is formed between the cover element and the cutting body. Alternatively, it is also conceivable for the cover element to terminate flush with the end of the rod element facing the drill head.

It is furthermore proposed that the transport channel extends straight, in particular parallel to the longitudinal axis. Alternatively, it is also conceivable for the grooves forming the transport channels to extend in a curved manner, in particular helically around the longitudinal axis of the drilling tool.

It is furthermore proposed that the transport channel has a front suction opening on the end face, which is arranged in the region of the drill head, wherein the ratio between the cross section of the suction opening and the cross section of the transport channel is at least 0.5, in particular at least 0.7, preferably at least 0.85. Advantageously, a particularly high air volume flow can thereby be achieved in the region of the drill head. Alternatively, it is also conceivable that the cross section of the suction opening corresponds substantially to the cross section of the transport channel.

It is furthermore proposed that the cover element has a suction opening in the attachment region, wherein the recess changes, in particular becomes smaller, in the region of the suction opening. Alternatively, it is also conceivable that the suction opening is formed only partially by the cover element. Preferably, the recess terminates with the suction opening.

It is furthermore proposed that the cover element is configured in a replaceable manner. Advantageously, the cover element can thereby be replaced with a high degree of wear. In particular, the cover element is configured in a tool-free manner. For example, it is conceivable that the cover element is fastened in the recess by a force-locking and/or form-locking connection (for example a slot/key connection or a dovetail connection) that can be released without tools, the connection being designed such that the cover element snaps in if the connection is successful.

It is furthermore proposed that the cover element is locally reinforced. In particular, the cover element is constructed in a reinforced manner in the region thereof subjected to high loads. Advantageously, the service life of the drilling tool can thereby be increased. Preferably, the cover element is made of plastic, which is reinforced in the front region by a metallic material.

It is further proposed that the lever element has at least one recess located on the outside. Advantageously, the transport channel can be unfolded by means of a groove between the lever element and the cover element located on the outside. In this context, an outer groove is to be understood as a groove which opens radially outwards with respect to the longitudinal axis. Preferably, the groove located on the outside is arranged in the circumferential side of the lever element.

It is furthermore proposed that the recess in the rod element is open in the axial direction at the end face end of the rod element. Preferably, the groove on the outside is configured to be open in the axial direction at the end of the rod element facing the drill head. Advantageously, the production of the suction opening can thereby be simplified and optimized.

Drawings

Other advantages will be derived from the following description of the drawings. The figures, description and claims contain numerous features in combination. Those skilled in the art will also suitably observe the features individually and combine them into other meaningful combinations. The reference numerals of the substantially mutually corresponding features of the different embodiments of the invention have the same numerals and letters representing the embodiments.

The drawings show:

FIG. 1 is a schematic view of a tool system;

FIG. 2a is a longitudinal cross-sectional view of a drilling tool according to the present invention;

FIG. 2b is a perspective view of the drilling tool according to FIG. 2 a;

FIG. 3 is a perspective view of an alternative embodiment of the drilling tool;

FIG. 4 is a perspective view of another alternative embodiment of the drilling tool;

FIG. 5 is a longitudinal cross-sectional view of another alternative embodiment of the drilling tool;

FIG. 6a is a perspective view of another alternative embodiment of the drilling tool;

fig. 6b is a longitudinal section of the drilling tool according to fig. 6 a.

Detailed Description

Fig. 1 shows a schematic view of a tool system 200. Tool system 200 includes drilling tool 10, hand-held power tool 300, and suction apparatus 400. The hand-held power tool 300 is embodied, for example, as a hammer drill. The hand-held power tool 300 has a tool receptacle 302 which is designed to receive a tool insert, which is designed as a drilling tool 10, for example. The hand-held power tool 300 has a drive unit, not shown, comprising an electric motor and a transmission comprising a pneumatic impact mechanism. By means of the drive unit and the transmission, the drilling tool 10 can be driven in a coupled state in a manner that it rotates about the longitudinal axis 12 of the drilling tool 10 and oscillates or impacts linearly along the longitudinal axis 12.

The drilling tool 10 is configured as a rock drill bit and is shown in an enlarged view in fig. 2 a. In addition, a perspective view of the drilling tool 10 is shown in fig. 2 b. The drilling tool 10 is provided in particular for producing a borehole in a workpiece 14, which is constructed, for example, as a masonry. The drill hole is created by percussive movement of the drill 10 along the longitudinal axis 12 and rotational movement of the drill 10 about the longitudinal axis 12. The drilling tool 10 has an insertion end 16 that is configured to couple the drilling tool 10 with the hand-held power tool 300.

The insertion end 16 is essentially cylindrical in shape and has a form-locking element 18, which is configured as an elongated recess. The tool holder 302 of the hand-held power tool 300 has a corresponding form-locking element, not shown, which is connected in the coupled state to the form-locking element 18 of the drilling tool 10. From the insertion end 16, the drilling tool 10 has an attachment region 20, a stem region 22 and a tool head 24 extending longitudinally along it for connecting the drilling tool 10 with the suction adapter 402. The front end of the drill 10 is formed by the drill head 24 and the rear end of the drill 10 is formed by the insertion end 16.

The suction adapter 402 is connected via a hose 403 to a suction device 400, which is configured as an industrial cleaner. The suction adapter 402 and the drilling tool 10 are rotatably connected with respect to each other. The drilling tool 10 is completely surrounded by the suction adapter 402 in the attachment region 20. The drilling tool 10 has a connecting element 26 in the attachment region 20, which is configured as an externally encircling groove. The suction adapter 402 has a corresponding connecting element 404, which is configured as a rubber ring. In the connected state, the connecting elements 26, 404 engage in one another in such a way that the suction adapter 402 is axially fixed.

In fig. 2b, a perspective view of the drill head 24 and the shank region 22 adjoining it is shown. The drill head 24 is constructed as a solid metal head and has a single cutting body 28. The cutting body 28 comprises four cutting elements 30, in particular two main cutting elements 32 and two auxiliary cutting elements 34. The cutting body 28 is configured as a star or cross, wherein the cutting elements 30 extend radially outwards from the center of the cutting body 28. A recess 29 is formed in the cutting body 28 between the cutting elements 30. The cutting body 28 is constructed in one piece. The primary cutting elements 32 and the secondary cutting elements 34 are alternately arranged in a circumferential direction 36 about the longitudinal axis 12. The drill head 34 has a tip 38 embodied as a centering tip, which protrudes on the end face in such a way that it initially contacts the workpiece 14. The drilling tool 10 has a rod element 40 and two cover elements 42 in the rod region 22. At its end facing the drill head 28, the shank element 40 has a junction 41 embodied as a blunt surface, by means of which the cutting body 28 is connected to the shank element 40 by means of a welded connection. A transport channel 44 for transporting drill cuttings out of the drill hole is arranged radially between the rod element 40 and the cover element 42. Transport channel 44 extends completely through rod region 22 along longitudinal axis 12. The transport channel 44 has a suction opening 46 through which drill cuttings can enter the transport channel 44 during production of the drill hole and a suction opening 48 through which the drill cuttings leave the transport channel 44.

The rod element 40 has two outer grooves 45 which extend straight and parallel to the longitudinal axis 12 through the rod region 22. The recess 45 is configured to be open in the axial direction at its end facing the drill head 24, and the recess 45 is closed in the axial direction at its end facing away from the drill head 24. Furthermore, the grooves 45 in the lever element 40 open radially outwards along its longitudinal extension. In the radial direction, the recess 45 in the rod region 22 is closed by the cover element 42 in such a way that the transport channel 44 in the rod region 22 is closed in the circumferential direction 36. The cover element 42 is illustratively connected to the lever element 40 in a material-locking manner. The transport channels 44 each have a cross section 50 that is substantially constant. The cross section 50 of the transport channel 44 is configured to be constant over the entire rod region 22. In other words, the profile of the transport channel 44 has a substantially straight frame line. In particular, the frame line is configured to be straight along substantially the entire transport path 44, preferably between the suction opening 46 and the suction opening 48.

The suction opening 46 is arranged in the region of the drill head 24. The suction port 46 is formed by an axially open end of the transport passage 44. The suction opening is laterally delimited by a lever element 40 and a cover element 42. The cross section 47 of the suction port 46 extends substantially perpendicular to the longitudinal axis 12 of the drilling tool 10. The cross section 47 of the suction opening 46 corresponds substantially to the cross section of the transport channel 44 in the shaft region 22. In particular, the cover element 42 ends flush with the lever element 40 on the end side, so that the suction opening 46 is formed immediately before the cutting body 28. Preferably, the cover element 42 terminates at the engagement face 41 of the lever element 40. In particular, the outer groove 45 in the rod element 40 is shaped in such a way that it merges flush into the recess 29 between the cutting elements 30 of the cutting body 28.

The radially outer groove 45 of the lever element 40 ends in the attachment region 20. In particular, the groove 45 in the rod element 40 located on the outside is configured to be closed in the axial direction in the attachment region 20 by a continuous tapering of the cross section in the axial direction. The length of the cover element 42 is configured such that the recess 45 is not completely closed by the cover element 42 in the attachment region 20, thus forming a suction opening 48. The suction opening 48 opens substantially perpendicular to the suction opening 46 or in a radial direction relative to the longitudinal axis 12 of the drilling tool 10.

Fig. 3 shows a perspective view of an alternative embodiment of drilling tool 10 a. The drill 10a differs, inter alia, in the length of the cover member 42 a. Unlike the previous embodiments, the cover element 42 does not terminate at the level of the engagement surface 41 of the lever element 40, but rather protrudes into the drill head 24a or into the cutting body 28 a. Thus, the cover element 42a is arranged in the recess 29a between the cutting elements 30 a. In particular, the cover element 42a extends to immediately before the start of the cutting face of the cutting element 30 a. The transport channel 44 thus has two subsections, wherein the transport channel 44 is delimited in the first subsection in the radial direction by the cover element 42a and the rod element 40a and in the second subsection in the radial direction by the cover element 42a and the cutting body 28 a. The cross section of the transport channel 44 in the first subsection essentially corresponds to the cross section of the transport channel 44 in the second subsection. However, it is also conceivable to reduce the cross section in the second subsection in order to generate a higher speed of the air volume flow in the region of the drill head 24 a. In particular, the cross section of the second subsection corresponds to at least 25%, preferably at least 50%, preferably at least 75% of the cross section of the first subsection in the shaft region.

Fig. 4 shows a perspective view of another alternative embodiment of drilling tool 10 b. Unlike the previous embodiment, the drilling tool 10b, and in particular the rod element 40b, has four grooves 45b, 49b located on the outside. The grooves 45b, 49b located on the outside are evenly spaced apart from one another in the circumferential direction and have substantially the same cross section in the rod region 22 b. The grooves 45b, 49b open in the axial direction and end at the same height at the front end, in particular in the region of the engagement surface 41b of the lever element 40 b. Two recesses 45b, which are closed in the radial direction by the cover element 42b, are assigned to the transport channel 44b and are provided for sucking away the drill cuttings. The other two recesses 49b are open in the radial direction and form an inflow channel 66b which is provided to increase the air volume flow in the region of the drill head 24 b. The hollows 29b between the cutting elements 30b of the cutting body 28b are attached to the ends of the grooves 45b, 49b. The groove 49b forming the inflow channel 66b is configured to be shorter than the groove 45b associated with the transport channel 44 b. In particular, the groove 49b forming the inflow channel 66b terminates at the stem region 22 b.

Fig. 5 shows a longitudinal cross-sectional view of another alternative embodiment of drilling tool 10 c. In this embodiment, the drilling tool 10c has a cover element 42c that is configured in a reinforced manner. The cover element 42c is constructed in a reinforced manner, in particular at its end facing the drill head 24c, in order to resist high temperatures and wear during drilling. The cover element 42c is made of plastic, wherein the cover element 42c has a reinforcing element 43c in the form of a sheet metal part in the end facing the drill head 24 c. Illustratively, the cover element 42c can be manufactured by an injection molding process in which the encapsulation reinforcement element 43c is injection molded. Alternatively, it is also conceivable to connect the reinforcing element 43c to the cover element 42c in a material-locking manner, for example by adhesive bonding. Furthermore, it is also conceivable to connect the reinforcing element 43c to the cover element 42c in a form-locking manner, for example by fitting a metal cap over the end face end of the cover element 42 c. It is also conceivable for the cover element 42c to be constructed in two parts, wherein a more heat-resistant subsection (which is made of metal, for example) is arranged in the region facing the drill head 24c, and a less heat-resistant subsection (which is made of plastic, for example) is arranged in the region facing the insertion end.

Fig. 6a shows a perspective view of another alternative embodiment of drilling tool 10 d. Fig. 6b furthermore shows a longitudinal section of the drilling tool 10 d. The drilling tool 10d, in particular the rod element 40d, has four grooves 45d located on the outside. The grooves 45d located on the outside are uniformly spaced apart from each other in the circumferential direction and have substantially the same cross section in the rod region 22 d. The recess 45d ends open in the axial direction at the front end at the same height, in particular in the region of the engagement surface 41b of the lever element 40 b. The recesses 45d are each closed in the radial direction by means of the cover element 42d, whereby a transport channel 44d is formed. The cover element 42d likewise ends at the level of the engagement surface 41 d. The cover element 42d is configured in a reinforced manner in its region facing the drill head 24 d. The reinforcement is achieved by the thickened portion 43 d. In particular, the cross section of the cover member 42d increases in the front region, thereby improving the heat resistance of the cover member 42d. In particular, the cross-section of the cover element 42d increases by at least 100%, preferably at least 150%. The cover element 42d is illustratively constructed in one piece. However, it is also conceivable to reinforce the cover element 42d additionally by a metal component in the region of the thickened portion 43 d.

Claims

1. A drilling tool extending along a longitudinal axis (12), comprising a tool head (24), an attachment region (20) for connecting the drilling tool (10) with a suction device (400), a shaft region (22) arranged between the tool head (24) and the attachment region (20), at least one transport channel (44) extending along the shaft region (22), wherein the shaft region (22) has a shaft element (40) and a cover element (42), wherein the shaft element (40) has at least one groove (45) located on the outside, the cover element (42) covering the groove (45) in the radial direction and thereby forming a first subsection of the transport channel (44) between the cover element (42) and the shaft element (40),

it is characterized in that the method comprises the steps of,

the tool head (24) is designed as a one-piece hard metal head, wherein a single cutting body (28) having cutting elements (30) is connected to the rod element (40) by means of blunt surfaces (41), and the cover element (42) protrudes at least partially into the recess between the cutting elements of the cutting body (28) of the tool head (24) and thereby forms a second subsection of the transport channel (44) between the cutting body (28) and the cover element (42).

2. Drilling tool according to claim 1, characterized in that the transport channel (44) extends straight and/or the cover element is locally reinforced and/or the transport channel (44) has a substantially constant cross section (50).

3. Drilling tool according to claim 1 or 2, wherein the transport channel is substantially delimited radially by an envelope curve circumscribing the rod element (40).

4. Drilling tool according to claim 1 or 2, characterized in that the transport channel (44) has a front suction opening (46) at the end, which is arranged in the region of the drill head (24), wherein the ratio between the cross section (47) of the suction opening (46) and the cross section (50) of the transport channel (44) is at least 0.5.

5. Drilling tool according to claim 1 or 2, characterized in that the cover element (42) has a suction opening (48) in the attachment region (20), wherein the recess (45) changes in the region of the suction opening (48).

6. Drilling tool according to claim 1 or 2, characterized in that the cover element (42) is constructed in a replaceable manner.

7. Drilling tool according to claim 1 or 2, characterized in that the rod element has at least two mutually different grooves located on the outside, wherein at least one groove is assigned to the transport channel and at least one further groove forms an inflow channel.

8. Drilling tool according to claim 1, characterized in that the cover element is made of plastic, which is reinforced in the front region by a metallic material.

9. Drilling tool according to claim 1 or 8, wherein the cover element is reinforced in the front region by a thickening.

10. Drilling tool according to claim 1 or 2, wherein the drilling tool is a rock drill bit.

11. Drilling tool according to claim 2, wherein the transport channel (44) extends parallel to the longitudinal axis (12).

12. A drilling tool according to claim 3, wherein the transport channel (44) is radially delimited by the cover element (42).

13. Drilling tool according to claim 4, characterized in that the ratio between the cross-section (47) of the suction opening (46) and the cross-section (50) of the transport channel (44) is at least 0.7.

14. Drilling tool according to claim 4, characterized in that the ratio between the cross-section (47) of the suction opening (46) and the cross-section (50) of the transport channel (44) is at least 0.85.

15. Drilling tool according to claim 5, characterized in that the recess (45) is smaller in the region of the suction opening (48).