AU2010226897A1 - Lathe tool, in particular boring tool - Google Patents

Description

AUSTRALIA Patents Act COMPLETE SPECIFICATION (ORIGINAL) Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: Kennametal Inc. Actual Inventor(s): Horst Manfred Jsger, Berthold Heinrich Zeug Address for Service and Correspondence: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: LATHE TOOL, IN PARTICULAR BORING TOOL Our Ref: 895455 POF Code: 1425/1425 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1 - 2 Lathe tool, in particular boring tool 5 The present application is a divisional application from International patent application number PCT/EP2009/002405, the entire disclosure of which is incorporated herein by reference. 10 Background of the Invention The invention relates to a lathe tool, in particular a multi-piece boring tool composed from at least one 15 borer body and a borer head which can be coupled thereto. The tool is generally a rotary tool for machining a workpiece. The tool is of multi-piece, in particular of 20 two-piece, design and comprises a receiving part and a front part. In the case of a boring tool, the receiving part is the boring body and the front part is the boring head. In the case of a milling tool, the receiving part would be a milling cutter shank and the 25 front part would be a milling cutter head. These two parts extending along a center axis (axial direction) are detachably fastened to one another via a driver connection. The latter has two coupling pairs separate from one another and arranged eccentrically with 30 respect to the center axis. Each of the coupling pairs is in this case formed by two interlocking coupling elements, namely, on the one hand, a driver pin and, on the other hand, a receiving pocket completely enclosing said driver pin. The coupling elements serve firstly to 35 transmit the torque forces between the two parts. Secondly, the two coupling elements also serve to orient the two parts in alignment with one another; i.e. the two parts are centered relative to one another 3 and with respect to the center axis via the coupling elements. EP-A-1 524 052 discloses a boring tool with a boring 5 head and a boring body. An intermediate disc is inserted between the boring head and the boring body. The discussion of documents, acts, materials, devices, articles and the like is included in this specification 10 solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed 15 before the priority date of each claim of this application. Throughout the description and claims of this specification, the word "comprise" and variations of 20 the word, such as "comprising" and "comprises", is not intended to exclude other additives, components, integers or steps. 25 Object of the Invention A preferred object of the invention is to improve a tool of the type mentioned at the beginning with respect to its running performance. 30 Summary of the Invention According to the present invention there is provided a multi-piece boring tool composed from at least one 35 borer body, a borer head which can be coupled thereto, a supporting element arranged between the borer body and the borer head which, for forming a sliding section, has an annular region projecting beyond the 4 lateral surface of the borer body and of the borer head. In accordance with an embodiment of the invention, a 5 supporting element is mounted in the coupling region, that is to say in the region of the parting line between borer body and borer head. The supporting element can be produced from a specially adapted material and serves to specifically stabilize the tool 10 in the coupling region. The supporting element serves to dampen any movements or vibrations of the borer body and of the borer head relative to one another. In particular, opposed vibrations of borer head and borer body are to be reduced or neutralized in order to 15 reduce the vibration wear of the tool. In addition, the transmission of solid-borne sound in the region of the parting line between borer body and borer head is to be reduced or eliminated. This reduction in the transmission of solid-borne sound also leads to an 20 improvement in the properties of the tool. Such tools are especially suitable for transverse bores of considerable depth in workpieces. In addition, the tools are also suitable for bores having oblique bore 25 exits. In a first configuration, the supporting element is configured as a disk which is plane-parallel to the end faces, adjacent to one another, of borer body and borer 30 head. This disk-shaped supporting element preferably projects like a sliding ring segment beyond the lateral surfaces of borer body and borer head and thus supports the boring tool relative to the bore wall. In this way, the course of the boring tool in the bore is 35 stabilized, while the cutting edges in the borer head can machine the bore wall. A further preferred embodiment of the supporting element has a ring-like integrally formed portion which 5 overlaps the lateral surfaces either of the borer body or of the borer head or of borer body and borer head at the same time. This embodiment has the advantage that the supporting element bears like a 5 sliding ring against a large area of the bore wall. In addition, in a bowl-like configuration of the supporting element having a basic body configured as a plane-parallel disk and an annular integrally formed portion, especially good mounting of the borer body and 10 of the borer head in the coupling region is ensured. In a further configuration, recesses corresponding to the flutes formed in the borer body and in the borer head can be provided in the supporting element in order to optimize the chip removal. The comparatively large 15 outer circumferential surface of the ring-like integrally formed portion on the supporting element enables the attachment of special guide elements for guiding the boring tool on the bore wall. These guide elements can be strip-shaped or bulged or can be 20 designed in other geometries for improving the concentric running of the tool in the bore. These guide elements can be integrally embedded in the outer surface of the ring element. However, it is also possible to fix them in the ring element in a clamping 25 manner. In a further configuration, the supporting element can have a coating, in particular in the region of the ring-like integrally formed portion. This coating can 30 serve to prevent the wear on the outer surface of the ring relative to the bore wall. The coating can also influence the other vibratory and transmission properties of the tool. 35 In a further embodiment of the invention, the ring-like integrally formed portion, in particular in the configuration as a receiving bowl, can at the same time be configured as a flexural spring. In this configuration, the ring element applies a spring force 6 to the bore wall and thus counters drifting of the tool away from its centered position with the acting spring force. The tool is therefore resiliently guided on the bore wall. In this way, the supporting element 5 forms a damping member for the tool relative to the workpiece to be machined. Description of the Figures 10 Exemplary embodiments of the invention are explained below in more detail with reference to the figures. In the drawing, partly in schematic illustration: fig. 1 shows an overall view of a section of a first 15 embodiment of the boring tool with supporting element, fig. 2 shows an exploded illustration of the boring tool shown in fig. 15, fig. 3 shows a view of the coupling surface of the 20 borer head according to fig. 15, fig. 4 shows a view of a supporting element according to fig. 15 designed as a plane-parallel disk, fig. 5 shows a plan view of the coupling surface of the borer body from fig. 15, 25 fig. 6 shows the exploded illustration of a borer body and of a supporting element having a two-sided receiving bowl, fig. 7 shows the exploded illustration from fig. 20 having a supporting element with a receiving 30 bowl effective in the direction of the borer body, fig. 8 shows an exemplary embodiment, modified compared with the exemplary embodiment shown in fig. 21, of a supporting element with an 35 enlarged receiving bowl, fig. 9 shows an embodiment of the supporting element having guide elements on the outer circumferential surface of the annular integrally formed portion, 7 fig. 10 shows an embodiment of an annular integrally formed portion configured as a flexural spring and as a receiving bowl, and fig. 11 shows a section through the ring-like 5 integrally formed portion shown in fig. 24 and configured as a flexural spring. Parts having the same effect are provided with the same designation in the figures. The driver connection is 10 described below with reference to a boring tool in various embodiment variants. The driver connection can also be generally applied to other cutting tools for coupling two parts of a tool. The individual features described below with respect to the various variants 15 and design configurations, provided they are not mutually exclusive, can also be combined with one another. Description of the Exemplary Embodiments 20 The borer head 4 in fig. 1 has, on its cutting side 62, the boring point 10 and two cutting tips 12 opposite one another at the circumference. Furthermore, coolant passages 65 and fastening means 66 are provided in the 25 region of the borer head 4. The fastening means 66 serve, for example, to fasten the cutting tips 12 or to fasten cutting tip holders or the like. The head coupling side 67 is remote from the cutting 30 side 62 of the borer head 4. The head coupling side 67 has that end face of the borer head 4 which faces the borer body 6. From this end face on the head coupling side 67, in the exemplary embodiment, two driver pins 18 project from the head coupling side 67 in the 35 direction of the borer body 6. The driver pins 18 again also have the rear openings of the coolant passages 65. That side of the borer body 6 which faces the borer head 4 is the shank coupling side 70. The shank 8 coupling side 70 and the head coupling side 67 form the coupling region between borer body 6 and borer head 4. Two receiving pockets 20 designed to be complementary to the driver pins 18 are formed in the 5 surface of the shank coupling side 70. Coolant passages 65 can again be seen in the receiving pockets 20, said coolant passages 65 being in alignment with the coolant passages 65 in the borer head 4 in the final assembled state. The coolant passages 65 therefore pass through 10 the entire boring tool. Finally, both the borer head 4 and the borer body 6 each have a centering bore 72. Flanks 73 on the borer head 4 and on the borer body 6 and helical flutes 15 incorporated between the flanks 73 can also be seen. 15 The tool mounting end (not shown in the figures) of the borer body 6 is remote from the shank coupling side 70 on the borer body 6. With the tool mounting end, the borer body 6 is clamped in place in the boring tool. 20 In the exemplary embodiment according to fig. 1 and fig. 2, the supporting element 75 designed as a plane parallel plate is arranged between the borer head 4 and the borer body 6. The supporting element 75 has 25 through-openings 76 corresponding to the outer contour of the driver pins 18. By means of the through-openings 76, the supporting element 75 is slipped onto the borer head 4 in a simple manner, the driver pins 18 passing through the supporting element 75 in the through 30 openings 76. The driver pins 18 thus form a form fit with the supporting element 75. For the final assembly, shown in fig. 1, of the tool, the driver pins 18 first of all pass through the through-openings 76 in order to then engage in the receiving pockets 20 in the borer 35 body 6 in a form-fitting manner. The supporting element 75 also has a centering bore 72. Furthermore, the supporting element 75 has recesses 77 corresponding with the flutes 15.

9 It can be seen from the illustration in fig. 1 that the supporting element 75 projects beyond the lateral surface, formed by the flanks 73, of the borer head 4 and of the borer body 6. In the finally assembled 5 boring tool, the supporting element 75 therefore forms a protruding annular region 78 which projects beyond the envelope surface of the boring tool, namely of the borer head 4 and of the borer body 6. During the boring operation, the supporting element 75 bears with this 10 annular region 78 against the bore wall and thus guides the tool relative to the bore wall. The exploded illustration in fig. 6 shows a borer body 6 identical to figs 1 to 5. In the exemplary embodiment 15 according to fig. 6, the supporting element 75 has a ring-like integrally formed portion 79. The integrally formed portion 79 overlaps both the head coupling side 67 of the borer head 4 and the shank coupling side 70 of the borer body 6 in the direction of the center axis 20 8 of the boring tool. The supporting element 75 shown in fig. 6 therefore forms a two-sided receiving bowl for receiving both the head coupling side 67 of the borer head 4 and the shank coupling side 70 of the borer body 6. 25 In contrast thereto, the exemplary embodiment of the supporting element 75 shown in fig. 7 has only one annular integrally formed portion 79, which extends in the direction of the center axis 8 of the boring tool 30 toward the shank coupling side 70 of the borer body 6. In other words, the annular integrally formed portion 79 only overlaps the shank coupling side 70 of the borer body 6 and at the same time bears as a plane parallel plate against the head coupling side 67 of the 35 borer head 4. In contrast thereto, the annular integrally formed portion 79 in the exemplary embodiment shown in fig. 6 overlaps both the shank coupling side 70 of the borer 10 body 6 and the head coupling side 67 of the borer head 4 and thus forms a double-sided receiving bowl for both the shank coupling side 70 of the borer body 6 and the head coupling side 67 of the borer head 5 4. The exemplary embodiment according to fig. 7, on the other hand, forms only one receiving bowl for the borer body 6, namely the shank coupling side 70 of the borer body 6. 10 The exemplary embodiment shown in fig. 8 again shows a supporting element 75 having a receiving bowl which is effective only with regard to the borer body 6 and a plane-parallel plate bearing against the borer head 4. In contrast to the exemplary embodiment shown in fig. 15 7, the annular integrally formed portion 79 overlaps the shank coupling side 70 of the borer body 6 by a considerably greater amount in this exemplary embodiment. When the tool is assembled, the extent of the integrally formed portion 79 in the direction of 20 the center axis 8 is considerably greater than in the exemplary embodiment shown in fig. 7. In this way, it is possible to arrange guide elements 81 on the annular integrally formed portion 79. 25 The exemplary embodiment shown in fig. 9 shows, as an example of such guide elements 81, guide studs attached in pairs to the annular integrally formed portion 79. These guide elements 81 slide on the bore wall during the machining process. 30 The exemplary embodiment shown in fig. 10 again shows a supporting element 75 having a receiving bowl effective only in the direction of the borer body 6. In this case, the annular integrally formed portion 79 is 35 configured as a flexural spring. For this purpose, a spring slot 82 is made in the annular integrally formed portion 79. Furthermore, it can be seen from the illustration in fig. 11 that the guide elements 81 are pushed from the borer body 6 into the annular 11 integrally formed portion 79. On account of its spring action, the annular integrally formed portion 79 is resiliently mounted on the boring tool in the transverse direction 83 running transversely to the 5 center axis 8. The supporting element 75 is thus designed as a flexural spring element. It is of course possible for all the embodiments in fig. 7 to fig. 10, with regard to the configuration of 10 the supporting element 75 as a receiving bowl in relation to the borer body 6, to also be equally applied to the borer head 4. Configurations are also conceivable in which a receiving bowl acting on both sides overlaps not only the shank coupling side 70 of 15 the borer body 6 but also a smaller region of the head coupling side 67 of the borer head 4.

12 List of designations 2 Boring tool 4 Borer head 6 Borer body 8 Center axis 10 Borer point 12 Cutting tip 14 Discharge opening 15 Flute 16 Clamping screw 18 Driver pin 20 Receiving pocket 22, 22' Coolant bore 24, 24' Fastening bore 26 Coolant passage 28 Outer bearing surface 30 Driver surface 32 Compensating element 34 Fastening shank 36 Shank receptacle 38 Headless setscrew 40 Tool 42 Through-hole 44 Receptacle 46 Dog point 48 Clamping pin 50 Receiving opening 52 Clamping element 54 Recess 62 Cutting side 65 Coolant passage 66 Fastening means 67 Head coupling side 70 Shank coupling side 13 72 Centering bore 73 Flank 75 Supporting element 76 Through-opening 77 Recess 78 Annular region 79 Integrally formed portion 81 Guide element 82 Spring slot 83 Transverse direction ri, r 2 Radius of curvature Rotation angle

Claims (12)

1. A multi-piece boring tool composed from at least 5 one borer body, a borer head which can be coupled thereto, a supporting element arranged between the borer body and the borer head which, for forming a sliding section, has an annular region projecting beyond the lateral surface of the borer body and of the 10 borer head.

2. The tool as claimed in claim 1, wherein the supporting element comprises a disk which is plane parallel to the end faces, assigned to one another in 15 the coupling region, of borer body and borer head.

3. The tool as claimed in claim 2, further comprising a ring-like integrally formed portion on the supporting element in such a way that the integrally formed 20 portion partly overlaps the lateral surface of the borer body or of the borer head or both lateral surfaces in the coupling region.

4. The tool as claimed in claim 3, wherein the disk 25 and the integrally formed portion in each case form a receiving bowl for the ends of the borer body and of the borer head in the coupling region.

5. The tool as claimed in one of claims 1 to 4, 30 further comprising recesses corresponding to the flutes formed in the borer body and in the borer head.

6. The tool as claimed in one of claims 3 to 5, further comprising guide elements on the outer 35 circumferential surface of the ring-like integrally formed portion for guiding the boring tool on the bore wall. 15

7. The tool as claimed in one of claims 3 to 6, wherein the supporting element is at least partly coated. 5

8. The tool as claimed in claim 7, further comprising a wear-inhibiting coating.

9. The tool of claim 8, wherein the wear-inhibiting coating is located on the outer circumferential surface 10 of the ring-like integrally formed portion.

10. The tool as claimed in one of claims 3 to 9, further comprising wear-inhibiting elements on the outer circumferential surface of the annular integrally 15 formed portion.

11. The tool as claimed in one of claims 3 to 10, wherein the ring-like integrally formed portion is configured as a flexural spring. 20

12. A multi-piece boring tool substantially as hereinbefore described with reference to the accompanying drawings.