Method for face milling the end surface of an end of a tube

Abstract

The invention relates to a method for face milling the end surface of an end of a cylindrical tube, having a circular tube cross section, by means of a milling tool. The milling tool (1) used comprises cutting edges (2), which run in a cutting-edge plane extending perpendicularly to the intended axis of rotation (R) of the milling tool (1). In the centre of the milling tool (1), a guide body (3) projects away from the cutting edges (2) perpendicularly to the cutting-edge plane, the outer contour of the guide body being configured such that the latter can be introduced into the end of the tube and, in the process, aligns the milling tool (1) in relation to the tube such that the axis of rotation (R) of the milling tool (1) substantially coincides with the central longitudinal axis of the tube. For the purpose of implementing the method, the guide body (3) of the milling tool (1) is introduced into that end of the tube which is to be worked on and, for the purpose of performing the milling work, the milling tool (1) is driven around its axis of rotation (R) by means of a drive unit. The cutting edges (2) are guided against the end surface of the end of the tube, while in the process the end surface of the end of the tube is subjected to face milling by way of the cutting edges (2). The method according to the invention makes it possible, even under difficult conditions and without any great level of skill being required, to produce planar end surfaces which run perpendicularly to the longitudinal axis of the tube.

Description

[0001] Method for face milling the end face of a pipe end

[0002] TECHNICAL FIELD

[0003] The present invention relates to a method for face milling the end face of a pipe end, a milling tool for use in carrying out the method, a tool set comprising such a milling tool and the use of the milling tool for face milling the end face of a pipe end according to the preambles of the independent patent claims.

[0004] STATE OF THE ART

[0005] Providing pipe ends with flat faces running perpendicular to the pipe's longitudinal axis, as is essential for mirror welding PE pipes, for example, is a well-known problem on construction sites. Particularly when already installed pipes need to be adjusted in length, it is difficult and requires considerable craftsmanship to simultaneously create a flat face running perpendicular to the pipe's longitudinal axis when cutting the pipes, or to achieve this through reworking.

[0006] PRESENTATION OF THE INVENTION

[0007] The task therefore arises to provide a procedure and tools for carrying out the procedure with which the problems described above do not occur or at least can be avoided as far as possible.

[0008] This problem is solved by the subject-matter of the independent patent claims.

[0009] According to these, a first aspect of the invention relates to a method for face milling the end face of a pipe end with a milling tool. The pipe can, in principle, be made of any conceivable material, in particular plastic or metal, or composite materials.

[0010] The milling tool comprises one or more cutting edges which run in a cutting plane extending perpendicular to the intended axis of rotation of the milling tool. A guide body projects away from the cutting edge(s) in the center of the milling tool and perpendicular to the cutting plane. The outer contour of the guide body is designed such that it can be inserted into a cylindrical pipe with a circular pipe cross-section and a specific diameter and in doing so aligns the milling tool with respect to the pipe such that the axis of rotation of the milling tool essentially coincides with a central longitudinal axis of the pipe. The term "specific diameter" here and below refers to a pipe diameter in which the guide body can be arranged without any appreciable radial play relative to the pipe longitudinal axis, so that the guide body is centered in the pipe cross-section by the pipe's inner wall.

[0011] The guide body of the milling tool is inserted into the end of a cylindrical pipe to be machined, which has a circular pipe cross-section with the specific diameter.

[0012] To carry out the milling work, the milling tool is driven around its axis of rotation by means of a drive unit and the cutting edge or edges is or are guided against the end face of the pipe end, with the cutting edge or edges face milling the end face of the pipe end.

[0013] In other words, the first aspect of the invention relates to a method for face milling the end face of one end of a cylindrical pipe with a circular pipe cross-section using a milling tool. The milling tool used comprises cutting edges which run in a cutting plane extending perpendicular to the intended axis of rotation of the milling tool. A guide body projects away from the cutting edges in the center of the milling tool perpendicular to the cutting plane, the outer contour of which guide body is designed in such a way that it can be inserted into the pipe end and in the process aligns the milling tool with respect to the pipe in such a way that the axis of rotation of the milling tool essentially coincides with the central longitudinal axis of the pipe.To perform the process, the guide body of the milling tool is inserted into the pipe end to be machined, and to perform the milling operation, the milling tool is driven around its rotational axis by a drive unit. The cutting edges are guided against the end face of the pipe end, while the cutting edges face the end face of the pipe end.

[0014] The milling tool can be driven using manual energy, e.g. using a drive unit designed as a crank, or using external energy, e.g. using a drive unit designed as a cordless screwdriver.

[0015] The method according to the invention makes it possible to produce flat end faces running perpendicular to the longitudinal axis of the pipe, even under difficult conditions and without great manual skill.

[0016] In a preferred embodiment of the method, the milling tool is guided manually during milling, preferably together with the drive unit. This allows the method to be performed practically anywhere with minimal effort.

[0017] It is advantageous if the milling tool is guided manually by grasping a handle of the milling tool, which is penetrated by a physical element for driving the cutting edges and is rotationally decoupled from this physical element and the cutting edges. In this way, precise and safe guidance of the tool is possible. Particular preference is given to process variants in which the end face of one end of a plastic pipe is milled flat, preferably a PE plastic pipe. With such variants, the advantages of the invention become particularly apparent, in particular if the end faces are subsequently to be butt-welded.

[0018] The guide body of the milling tool used in carrying out the method preferably has an axial extension along the rotation axis that corresponds to at least one times the specific diameter of the pipe, in particular at least one and a half times the specific diameter of the pipe. This ensures good guidance of the tool through the inner pipe wall.

[0019] In a further preferred embodiment of the method, a milling tool with several interchangeable guide bodies of different sizes is provided and used for milling, whereby it is possible to use the milling tool for face milling end faces of the ends of pipes of different specific diameters.

[0020] According to a further preferred embodiment of the method, a milling tool is used in which the guide body is rotationally coupled to the cutting edges, so that it rotates in the pipe during milling. Such milling tools can be constructed relatively simply and can be produced accordingly cost-effectively.

[0021] According to an alternative preferred embodiment of the method, a milling tool is used in which the guide body is rotationally decoupled from the cutting edges, so that it does not perform any rotational movement in the pipe during milling. Such milling tools have the advantage that they can be used even on sensitive internal pipe surfaces, e.g., with coatings, without the risk of damage.

[0022] A second aspect of the invention relates to a milling tool for use in carrying out the method according to the first aspect of the invention.

[0023] The milling tool comprises one or more cutting edges which run in a cutting plane extending perpendicular to the intended axis of rotation of the milling tool. A guide body projects away from the cutting edge(s) in the center of the milling tool, perpendicular to the cutting plane, the outer contour of said guide body being designed in such a way that the guide body can be inserted into a cylindrical pipe to be machined with the milling tool, having a circular pipe cross-section with a specific diameter, and in doing so aligns the milling tool with respect to the pipe in such a way that the axis of rotation of the milling tool essentially coincides with a central longitudinal axis of the pipe.

[0024] As already mentioned, the term "specific diameter" refers to a pipe diameter in which the guide body can be arranged without any significant radial play relative to the pipe's longitudinal axis, so that the guide body is centered in the pipe cross-section by the pipe's inner wall.

[0025] The milling tool advantageously has a coupling body for coupling to a drive unit (e.g. cordless screwdriver), which forms the end of the milling tool facing away from the cutting edges. This coupling body is preferably designed as a uniform polygonal cylinder contour, advantageously as a hexagonal cylinder contour. Such coupling bodies are particularly suitable for being firmly clamped in a chuck of a drive unit or for being loosely inserted into a corresponding coupling contour of a drive unit. In a preferred embodiment, the milling tool has a handle that can be gripped by hand, which is penetrated by a body for driving the cutting edges and is rotationally decoupled from this body and the cutting edges. This makes it possible to guide the milling tool precisely and safely by hand during milling.

[0026] The guide body of the milling tool advantageously has an axial extension along the rotation axis that corresponds to at least one times the specific diameter of a pipe to be machined, in particular at least one and a half times the specific diameter of a pipe to be machined. This ensures good guidance of the tool through the inner pipe wall.

[0027] According to a further preferred embodiment of the milling tool, the guide body is rotationally coupled to the cutting edges, so that it rotates in the pipe during milling. Such milling tools can be constructed relatively simply and can be produced accordingly cost-effectively.

[0028] According to an alternative preferred embodiment of the milling tool, the guide body is rotationally decoupled from the cutting edges, so that it does not perform any rotational movement in the pipe during milling. Such milling tools have the advantage that they can be used even on sensitive internal pipe surfaces, e.g., with coatings, without the risk of damage.

[0029] The milling tool advantageously comprises a base body for driving the cutting edges, which base body carries a preferably replaceable cutting body that provides the cutting edges. This makes it possible to replace the cutting body and / or to use the base body together with different cutting bodies. It is further preferred that the base body additionally also carries the guide body, which is advantageously also replaceable. This makes it possible to replace the guide body and / or to use the base body additionally together with different guide bodies.

[0030] Furthermore, it is preferred that the base body extends through the cutting body and the guide body, with the base body advantageously extending over practically the entire axial extent of the milling tool. This promotes simple and stable tool designs.

[0031] In such milling tool designs, it is further advantageous that the handle is penetrated by the base body. This enables particularly compact tool designs.

[0032] In a further preferred embodiment, the milling tool comprises a drive unit for driving the same during the intended milling operation.

[0033] In a preferred variant, the base body is firmly connected to the drive unit. Such an embodiment could, for example, be designed as a cordless tool that can be equipped with cutting bodies and associated guide bodies for various specific pipe diameters.

[0034] A third aspect of the invention relates to a tool set comprising a milling tool according to the second aspect of the invention and a plurality of interchangeable guide bodies of different sizes to enable the milling tool to be used for face milling the end faces of pipe ends with different specific diameters.

[0035] In a preferred embodiment, the tool set further comprises several interchangeable cutting bodies of different sizes.

[0036] Such tool sets represent preferred commercial forms of the invention. A fourth and final aspect of the invention relates to the use of the milling tool according to the second aspect of the invention for face milling the end face of a pipe end, more preferably the end of a plastic pipe, advantageously made of PE.

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Further preferred embodiments of the invention will become apparent from the dependent claims and from the following description with reference to the figures. These show:

[0039] Fig. 1 is a perspective view of a first milling tool according to the invention;

[0040] Fig. 2 is a perspective exploded view of the milling tool from Fig. 1;

[0041] Fig. 3 shows a longitudinal section through the milling tool from Fig. 1;

[0042] Fig. 4 is a perspective view of the base body of the milling tool from Fig. 1;

[0043] Fig. 5 is a perspective exploded view of the base body of Fig. 4;

[0044] Fig. 6 is a perspective view of the cutting body of the milling tool from Fig. 1 with a view of the front of the cutting body;

[0045] Fig. 7 is a perspective view of the cutting body of the milling tool from Fig. 1 with a view of the rear side of the cutting body;

[0046] Fig. 8 is a perspective view of a cutting insert of the milling tool from Fig. 1;

[0047] Fig. 9 is a plan view of the cutting plate from Fig. 8;

[0048] Fig. 10 is a section along the line AA in Fig. 9;

[0049] Fig. 11 is a perspective view of the guide body of the milling tool from Fig. 1;

[0050] Fig. 12 is a plan view of the guide body of Fig. 11; Fig. 13 is a section along the line BB in Fig. 12;

[0051] Fig. 14 is a perspective view of a second milling tool according to the invention, showing the cutting side of the milling tool;

[0052] Fig. 15 is a perspective view of the second milling tool according to the invention as shown in Fig. 14, with a view of the non-cutting side of the milling tool;

[0053] Fig. 16 is a perspective exploded view of the milling tool of Fig. 14; and

[0054] Fig. 17 shows a longitudinal section through the milling tool from Fig. 14;

[0055] WAYS OF IMPLEMENTING THE INVENTION

[0056] Figures 1 to 3 show a first milling tool 1 according to the invention, namely once in a perspective top view of the cutting side of the milling tool 1 (Fig. 1), once in a perspective exploded view (Fig. 2) and once in a longitudinal section (Fig. 3).

[0057] As can be seen, the milling tool 1 has four cutting edges 2 on its cutting side, which are formed by four replaceable cutting plates 12. The cutting plates 12 are fastened to a cutting body 6 with screws 13 in such a way that the four cutting edges 2 run in a cutting plane perpendicular to the intended axis of rotation R of the milling tool 1. A circular cylindrical guide body 3 projects away from the cutting edges 2 in the center of the milling tool 1 perpendicular to this cutting plane, the central longitudinal axis of which guide body coincides with the intended axis of rotation R of the milling tool 1.

[0058] Detailed views of the cutting body 6, one of the cutting plates 12 and the guide body 3 are shown in Figures 6 to 13.

[0059] The cutting body 6 and the guide body 3 are carried by a base body 5 which passes through them and extends over the entire axial extent of the milling tool 1.

[0060] As can be seen in conjunction with Figures 4 and 5, which show the base body 5 once in a perspective top view (Fig. 4) and once in a perspective exploded view (Fig. 5), the base body 5 consists of a main element 17, which forms a hexagonal shaft 7 at its end facing away from the cutting side of the milling tool 1, for clamping in the chuck of a cordless screwdriver.

[0061] In the center, the main element 17 has a flange 16 and an external thread 18, onto which the cutting body 6 is screwed with a corresponding internal thread 19, so that it abuts against the flange 16. In this way, the cutting body 6 is rotationally rigidly connected to the base body 5 in the intended direction of rotation of the milling tool 1.

[0062] At its cutting-side end, the main element 17 forms a circular-cylindrical bearing stub 20, onto which the guide body 3 is pushed with a corresponding receiving bore 21. The bearing stub 20 provides locking balls 10 at two opposite circumferential positions which, when the guide body 3 is mounted, engage in a circumferential groove 22 in the receiving bore 21 of the guide body 3 and thereby secure it axially on the bearing stub 20. As a result, the guide body 3 is fastened to the base body 5 but is rotationally decoupled from the base body 5 and the cutting body 6.

[0063] To assemble and disassemble the guide body 3, the locking balls 10 must be unlocked, which is done by axially pressing on the end of a release bolt 15 protruding from the front side of the bearing stub 20.

[0064] The exact structure and functioning of this locking mechanism can be seen from a combination of Figures 3 and 5. As can be seen, the unlocking bolt 15 is arranged in a central bore 23 in the center of the bearing stub 20 and is axially displaceable therein against the force of a spring 14. To prevent it from falling out, it has an elongated hole 24 through which a locking pin 11 extends radially through the bearing stub 20. The locking pin 11 is press-fitted and frictionally secured in radial bores 25 in the bearing stub.

[0065] The release bolt 15 has areas with different diameters, which are dimensioned and arranged in such a way that in the unactuated state it prevents a radial penetration of the locking balls 10 into the bearing stub 20 and in the actuated state it allows a radial penetration of the locking balls 10 into the bearing stub 20, whereby an assembly or disassembly of the guide body 3 is then possible.

[0066] As can be further seen from Figures 1 to 3, the milling tool 1 has a housing 26 on its side facing away from the cutting edges 2, through which the base body 5 with the cutting body 6 carried thereby passes and which forms a handle 4 which simultaneously serves as a connection piece for a vacuum cleaner hose. The housing 26 is mounted on the main element 17 of the base body 5 by means of a rolling bearing 9. The rolling bearing 9 is secured on the main element 17 by means of a snap ring 8.

[0067] Figures 14 to 17 show a second milling tool 1 according to the invention, once in a perspective top view of the cutting side of the milling tool 1 (Fig. 14), once in a perspective top view of the non-cutting side of the milling tool 1 (Fig. 15), once in a perspective exploded view (Fig. 16) and once in a longitudinal section (Fig. 17). As can be seen, the milling tool 1 has four cutting edges 2 on its cutting side, which cutting edges are formed by four replaceable cutting plates 12. The cutting plates 12 are fastened to a cutting body 6 with screws 13 in such a way that the four cutting edges 2 run in a cutting plane perpendicular to the intended axis of rotation R of the milling tool 1.A circular-cylindrical guide body 3 extends perpendicularly to the cutting plane at the center of the milling tool 1 from the cutting edges 2, the central longitudinal axis of which coincides with the intended rotational axis R of the milling tool 1. The cutting plates 12 are identical to those of the previously described milling tool 1 and are shown in detail in Figures 8 to 10.

[0068] The cutting body 6 is fastened to a flange section 29 of a one-piece base body 5 by two fastening screws 27 and is penetrated by an oval projection 28 of the base body 5, which projects from the flange section 29. At its end facing away from the cutting side of the milling tool 1, the base body 5 forms a hexagonal shank 7 for clamping in the chuck of a cordless screwdriver.

[0069] At the cutting-side end of the base body 5, the guide body 3 is fastened with a central fastening screw 26, which forms an axis about which the guide body 3 can rotate. As a result, the guide body 3 is rotationally decoupled from the base body 5 and the cutting body 6.

[0070] While preferred embodiments of the invention are described in the present application, it is to be clearly understood that the invention is not limited thereto and may be embodied in other ways within the scope of the following claims.

Claims

Patentan's Sayings 1. A method for face milling the end face of a pipe end, comprising the steps of: a) providing a milling tool (1) with one or more cutting edges (2) which run in a cutting plane perpendicular to a designated axis of rotation (R) of the milling tool (1), wherein a guide body (3) projects from the cutting edge(s) (2) in the center of the milling tool (1) perpendicular to the cutting plane, the outer contour of which guide body is designed such that it can be inserted into a cylindrical pipe with a circular pipe cross-section of a specific diameter and in the process aligns the milling tool (1) with respect to the pipe such that the axis of rotation (R) of the milling tool (1) substantially coincides with a central longitudinal axis of the pipe; b) providing a drive unit with which the milling tool (1) can be driven about its axis of rotation (R) for performing milling work;c) Inserting the guide body (3) of the milling tool (1) into one end of a cylindrical pipe with a circular pipe cross-section and the specified diameter; d) Driving the milling tool (1) with the drive unit and, in the process, e) guiding the cutting edges (2) against the end face of the pipe end, thereby face-milling the end face of the pipe end with the cutting edge(s) (2) of the milling tool (1); 2. Method according to claim 1, wherein the milling tool (1) is guided by hand, in particular together with the drive unit.

3. Method according to claim 2, wherein the milling tool (1) is guided manually by gripping a handle (4) of the milling tool (1), which is penetrated by a body (5, 6) for driving the cutting edges (2) and is rotationally decoupled from this body (5, 6) and the cutting edges (2).

4. Method according to one of the preceding claims, wherein a cordless screwdriver is used as the drive unit.

5. Method according to one of the preceding claims, wherein the end face of one end of a plastic pipe is milled flat, in particular a PE plastic pipe.

6. Method according to one of the preceding claims, wherein a milling tool (1) is provided, the guide body (3) of which has an axial extension along the rotation axis (r) which corresponds at least to one time the specific diameter of the pipe, in particular at least to one and a half times the specific diameter of the pipe.

7. Method according to one of the preceding claims, wherein a milling tool (1) is provided with a plurality of interchangeable guide bodies (3) of different sizes to enable use of the milling tool (1) for face milling end faces of the ends of pipes of different specific diameters.

8. Method according to one of the preceding claims, wherein the guide body (3) with the cutting edges (2) is rotationally coupled and rotates during milling in the pipe.

9. Method according to one of claims 1 to 7, wherein the guide body (3) is rotationally decoupled from the cutting edges (2) and does not perform any rotational movement relative to the pipe during milling.

10. Milling tool (1) for use in carrying out the method according to one of the preceding claims, comprising one or more cutting edges (2) which run in a cutting plane perpendicular to a designated axis of rotation (R) of the milling tool (1), wherein a guide body (3) projects from the cutting edge or edges (2) in the center of the milling tool (1) perpendicular to the cutting plane, the outer contour of the guide body being designed such that the guide body (3) can be inserted into a cylindrical pipe to be machined with the milling tool (1) and having a circular pipe cross-section of a certain diameter, and in the process aligns the milling tool (1) with respect to the pipe such that the axis of rotation (R) of the milling tool (1) substantially coincides with a central longitudinal axis of the pipe.

11. Milling tool (1) according to claim 10, wherein the milling tool (1) has a coupling body (7) for coupling to a drive unit, which is designed in particular as a uniform polygonal cylinder contour, in particular as a hexagonal cylinder contour, which forms the end of the milling tool (1) facing away from the cutting edges (2).

12. Milling tool (1) according to one of claims 10 to 11, wherein the milling tool (1) has a manually grippable handle (4) which is penetrated by a body (5, 6) for driving the cutting edges (2) and is rotationally decoupled from this body (5, 6) and the cutting edges (2).

13. Milling tool (1) according to one of the claims 10 to 12, wherein the guide body (3) has an axial extension along the rotation axis (R) which corresponds at least to one time the specific diameter of the pipe to be machined, in particular at least one and a half times the specific diameter of the pipe to be machined.

14. Milling tool (1) according to one of claims 10 to 13, wherein the guide body (3) is rotationally coupled to the cutting edges (2), in particular rigidly coupled.

15. Milling tool (1) according to one of claims 10 to 13, wherein the guide body (3) is rotationally decoupled from the cutting edges (2).

16. Milling tool (1) according to one of claims 10 to 15, wherein the milling tool (1) has a base body (5) for driving the cutting edges (2), which carries a particularly replaceable cutting edge body (6) which provides the cutting edges (2).

17. Milling tool (1) according to claim 16, wherein the base body (5) additionally carries the guide body (3), and in particular wherein the guide body (3) is replaceable.

18. Milling tool (1) according to claim 16 and claim 17, wherein the base body (5) passes through the cutting body (6) and the guide body (3) and in particular, wherein the base body (5) extends over the entire axial extent of the milling tool (1) 19. Milling tool (1) according to claim 12 and according to one of claims 16 to 18, wherein the handle (4) is penetrated by the base body (5).

20. Milling tool (1) according to one of claims 10 to 19, further comprising a drive unit for driving the milling tool (1) during the intended milling operation.

21. Milling tool according to one of claims 16 to 19 and according to claim 20, wherein the base body is fixedly connected to the drive unit.

22. Tool set comprising a milling tool (1) according to one of claims 10 to 21 and several interchangeable guide bodies (3) of different sizes, to enable use of the milling tool (1) for face milling end faces of the ends of pipes of different specific diameters.

23. Tool set according to claim 22, further comprising a plurality of interchangeable cutting bodies (6) of different sizes.

24. Use of the milling tool (1) according to one of claims 10 to 21 for face milling the end face of a pipe end, in particular the end of a plastic pipe, in particular made of PE.

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