WO2011031754A1

WO2011031754A1 - Pipe-machining apparatus with a cutting device

Info

Publication number: WO2011031754A1
Application number: PCT/US2010/048123
Authority: WO
Inventors: Andreas Frank
Original assignee: Illinois Tool Works Inc.
Priority date: 2009-09-09
Filing date: 2010-09-08
Publication date: 2011-03-17
Also published as: DE102009040840A1

Abstract

The invention relates to a pipe machining apparatus Pipe-machining apparatus with a cutting device, wherein the cutting device is movable relative to a pipe to be machined in an advancing direction (102) running radially with respect to the centre longitudinal axis of the pipe and in a cutting direction (101) running in the circumferential direction of the pipe, and wherein the cutting device has a tool holder (10) for fastening tools (40, 50) for machining of the pipe. In order, in a manner which is easy to realize but nevertheless effective, to be able to execute a plurality of machining steps in one operation using one pipe-machining apparatus, it is provided according to the invention a first tool (40) and a second tool (50) are fastened to the tool holder (10) in such a manner that, during the pipe machining, in which the cutting device moves relative to the pipe both in the advancing direction (102) and in the cutting direction (41) of the first tool (40) moves ahead of a cutting edge (51) of the second tool (50) both in the cutting direction (101) and in the advancing direction (102).

Description

Pipe-machining apparatus with a cutting device

The present invention relates to a pipe-machining apparatus with a cutting device in accordance with the preamble of independent patent claim 1.

According thereto, the invention relates in particular to a pipe-machining apparatus with a cutting device, wherein the cutting device is movable relative to a pipe to be machined in an advancing direction running radially with respect to the center longitudinal axis of the pipe and in a cutting direction running in the circumferential direction of the pipe, and wherein the cutting device has a tool holder for fastening tools for machining of the pipe.

A pipe-machining apparatus of this type is generally known in principle from the prior art. For example, the publication US 5,054,342 A describes a pipe-machining apparatus in the form of a pipe severing apparatus which can be fastened on the outside of a pipe to be machined. The pipe-machining apparatus known from this prior art has three radially displaceable clamping jaws which are in the shape of a circular arc and clamp the pipe in regions. Furthermore, a tool guide is provided, said tool guide surrounding, in the shape of a circular arc, the pipe which is to be machined and positioning two cutting tools, which are arranged offset by 180°, around the periphery of the pipe. Thin-walled pipes can be severed using said pipe-machining apparatus.

Secondly, pipe-machining apparatuses are also known for a metal-removing machining of pipe ends. A metal- removing machining of this type is frequently required as a preparatory step for a welding process or other machining process.

For example, the publication EP 033 588 A describes a pipe-machining apparatus for the metal-removing machining of pipe ends. For this purpose, the apparatus has a frame in which a hollow rod and, next to one another, a motor, a transmission arrangement and a tool holder are arranged. Furthermore, a clamping device for clamping a pipe end to be machined to the pipe- machining apparatus is provided. The drive shaft of the motor is connected to the tool holder by a transmission arrangement consisting of a belt drive and a planetary mechanism. The tool holder with the cutting tool is formed on one side, as seen from the hollow rod, and - because of the planetary mechanism - is arranged eccentrically .

Accordingly, different machining apparatuses are known for the different machining operations, such as, for example, for the severing of pipes or the beveling of pipe ends. In practice, a respective tool suitable for the particular machining operation (severing operation, metal-removing operation) has to be fastened to a tool holder of the pipe-machining apparatus for the individual working operations. The different machining operations each place different demands on the properties of the tool and of the tool material. For example, when severing or cutting off a pipe end, the cutting edge of the cutting tool is only in contact with the pipe being machined in a relatively small region, which has the consequence of the cutting edge of the tool being subjected to relatively high loads. On the other hand, when beveling a pipe end, the cutting surface of a machining tool comes into contact with a relatively large region of the pipe end, which reduces the loads acting on the individual regions of the cutting surface. Even if, in comparison to the cutting edge of a tool designed for a pipe severing operation - the cutting edge of a tool designed for metal-removing machining is exposed to lower loads, overall, nevertheless, relatively large forces are introduced into the tool during metal-removing machining, since the cutting edge is in contact with a relatively large region of the pipe end. The tool has to transmit said forces to the tool holder.

Since the tools used for beveling a pipe end have to be designed differently in a structural and functional respect than tools serving to sever pipes, said tools are customarily fastened to different tool holders such that the working operations of severing and of beveling can be carried out separately from each other, which increases the machining time and the operating costs, in particular if a pipe is to be entirely machined (severing and beveling), for example for a welding operation.

If both machining operations (severing and beveling) are undertaken simultaneously by an individual tool, the tool is subject to a high degree of wear because of the different types of load and has to be exchanged after a relatively short time, which likewise increases the operating costs of the pipe-machining apparatus. If, on the other hand, it is attempted to optimize one tool simultaneously for the different uses, the manufacturing thereof turns out to be correspondingly complicated and expensive. In particular, it is difficult to design the different regions of a tool to differ in hardness. On the basis of this definition of the problem, the invention is based on the object of developing a pipe- machining apparatus of the type mentioned at the beginning to the effect that a plurality of machining steps can be executed in one operation in a manner which is easy to realize but is nevertheless effective.

This object is achieved according to the invention by the subject matter of independent claim 1. Advantageous developments of the solution according to the invention are indicated in the dependent patent claims.

According thereto, a pipe-machining apparatus is proposed, which pipe-machining apparatus is equipped, according to the invention, with a cutting device, wherein the cutting device is movable relative to a pipe to be machined in an advancing direction running radially with respect to the center longitudinal axis of the pipe and in a cutting direction running in the circumferential direction of the pipe. It is conceivable in this case for the pipe-machining apparatus to be fastenable to the pipe to be machined with the aid of a clamping device in such a manner that the cutting device can move in the circumferential direction around the pipe to be machined. In this case, the movement of the cutting device in the circumferential direction of the pipe corresponds to the movement in the cutting direction, since, during said movement, a groove can be placed by the cutting device into the casing surface of the pipe to be machined. On the other hand, the cutting device also has to be movable in the advancing direction relative to the pipe to be machined such that the depth of the groove brought about in the casing surface of the pipe during the movement in the cutting direction can be increased. The distance by which the cutting device can move in the advancing direction relative to the casing surface of the pipe to be machined defines which wall thicknesses can be machined with the pipe-machining apparatus .

In order to be able to execute a plurality of machining steps in one operation using the pipe-machining apparatus according to the invention, the cutting device has a tool holder which is designed such that at least two machining tools can be fastened thereto at the same time. In a preferred realization of the pipe-machining apparatus according to the invention, a first tool of the at least two tools which can be fastened to the tool holder is designed for severing a pipe to be machined, wherein the cutting edge of said first tool is designed for cutting a groove running in the circumferential direction of the pipe in the pipe casing surface during the machining of the pipe.

A second tool designed for metal-removing machining is furthermore preferably fastenable to the tool holder, wherein the cutting edge of said second tool is designed for beveling the groove formed by the cutting edge of the first tool during the machining of the pipe.

So that the formation of the cutting groove and the beveling thereof can be carried out in one operation, according to the invention the first tool and the second tool of the at least two machining tools are fastened to the tool holder in such a manner that, during the pipe machining, in which the cutting device moves relative to the pipe both in the advancing direction and in the cutting direction, the cutting edge of the first tool moves ahead of the cutting edge of the second tool both in the cutting direction and in the advancing direction. This special arrangement of the at least two machining tools on the tool holder of the cutting device therefore has the effect that, when the cutting device is moved in the advancing and cutting directions relative to the pipe to be machined, the first tool which moves ahead of the second tool forms a cutting groove in the casing surface of the pipe whereas the second tool engages in said cutting groove and brings about, for example, metal-removing machining of the groove edge. It is apparent that the depth of the groove provided by the first tool in the casing surface of the pipe to be machined depends on the distance by which the cutting device or the cutting edge of the first tool is moved in the advancing direction relative to the pipe to be machined. The advantages which can be obtained with the solution according to the invention are obvious. In particular, a pipe-machining apparatus having a tool holder is proposed, wherein two different tools, i.e. tools for two different machining operations, can be fastened to said tool holder. During the machining of a pipe, said tool holder with the two tools fastened thereto is moved relative to the pipe to be machined in such a manner that, during said relative movement, the two tools are used for the purpose of machining of the pipe The movement of the tool holder relative to the pipe to be machined is realized by the tool holder, which forms part of a cutting device, being movable in an advancing direction and in a cutting direction relative to the pipe to be machined.

As already indicated, the term "advancing direction" used here is to be understood as meaning a direction running radially to the center longitudinal axis of the pipe to be machined. Secondly, the term "cutting direction" used here is intended to be understood as meaning a direction which runs perpendicularly to the advancing direction and in particular runs in the circumferential direction of the pipe to be machined. In principle, it is conceivable for the pipe-machining apparatus to be fastened to the pipe to be machined, for example with the use of corresponding clamping clips. In this case, the cutting device is connected to the pipe-machining apparatus in such a manner that the latter is movable in the cutting and in the advancing direction relative to the pipe to be machined. In order for the second tool which is fastened to the tool holder to be able to bring about metal- removing machining in an effective a manner as possible, it is preferred for the second tool to be fastened to the tool holder in such a manner that the cutting edge of the second tool encloses an acute angle, i.e. an angle of less than 90°, with the advancing direction.

As already explained, relatively high forces act on the corresponding tools during the machining of a pipe, and therefore particular measures have to be taken in order to fasten the tool securely to the tool holder. In particular, care has to be taken to ensure that the tool does not slip relative to the tool holder during the machining of the pipe, since otherwise the cutting edge of the tool will no longer lie on the desired line relative to the surface of the pipe to be machined.

In the solution according to the invention, in which at least two tools are fitted onto one and the same tool holder, wherein each individual tool is designed for a specific working operation, the forces acting on the respective tools during the machining of the pipe are precisely foreseeable in advance. This makes it possible to be able, in order to fasten the respective tools to the tool holder, to form associated receptacles in the tool holder, which receptacles receive the corresponding tools. In this case, the forces acting on the tool during the machining of the pipe are transmitted into a side surface of the corresponding receptacle of the tool holder. This embodiment permits the tool to be fastened to the tool holder in a manner which is easy to realize but is nevertheless effective, it basically being ensured that the tool cannot be displaced relative to the tool holde . In detail, in a preferred realization of the pipe- machining apparatus according to the invention, the tool holder has a first receptacle for receiving the first tool, the first tool, in the state thereof in which it is held in the first receptacle, being in contact at least in regions by means of a side surface opposite the cutting direction with a receiving surface of the first receptacle. Via said contact, the forces introduced into the first tool during the machining of the pipe are passed on to the tool holder and from there into the cutting device or pipe-machining apparatus. The provision of side surfaces into which the forces occurring during the machining of the pipe are introduced can in particular also avoid the occurrence of force peaks, which is a frequent cause of rapid material fatigue.

On the other hand, it is likewise conceivable, of course, for the tool holder to have a second receptacle for receiving the second tool, the second tool, in the state thereof in which it is held in the second receptacle, being in contact at least in regions by means of a side surface opposite the cutting direction with a side surface of the second receptacle. As a result, forces such as the forces which occur during the metal-removing machining and are introduced into the second tool can be introduced into the tool holder without there being the risk of the second tool being displaced relative to the tool holder.

In order for it to be possible for the cutting groove formed by the first tool during machining of a pipe to be completely remachined by the second tool, it is preferred for the vertical projections of the cutting edge of the first tool and of the cutting edge of the second tool onto the surface of the pipe to be machined to at least partially overlap in the extent of said surface along the longitudinal axis of the pipe. Accordingly, during the cutting operation, the respective cutting edges cover that region of the pipe which is to be machined without a gap. On the other hand, it is preferred for the first and second tools to be designed and arranged relative to the tool holder in such a manner that the vertical projection of the tool holder onto the surface of the pipe to be machined falls into a region which is limited in the extent thereof along the longitudinal axis of the pipe by the extent of the vertical projection of the cutting edge of the first tool and the extent of the vertical projection of the cutting edge of the second tool.

As already indicated, it is preferred if the first and/or second tool are/is accommodated in a corresponding receptacle formed in the tool holder. In this case, it is appropriate to releasably fix the tool to the tool holder, for example with the aid of a screw. Since the forces introduced into the tool during the machining of the pipe are introduced substantially into a side edge of the receptacle, the screw for the releasable fixing of the tool to the tool holder obtains only a small force transmission function (if any at all) . The screw can be of correspondingly small dimensions. In this case, it is in principle preferred if the screw head of the screw is recessed in a depression formed in the associated tool so that said screw head does not come into contact with the pipe to be machined.

The tools should preferably be designed as an indexable tip such that, if the cutting edge becomes worn, the tool, in the rotated state, can be fastened again to the tool holder and can be inserted into the associated receptacle of the tool holder. An exemplary embodiment of a tool holder which can be used in the pipe-machining apparatus according to the invention is described below with reference to the attached drawings, in which:

Fig. 1 shows a perspective view of a tool holder which can be used in the pipe- machining apparatus according to the invention ;

Fig. 2 shows a further perspective view of the tool holder according to fig. 1;

Fig. 3 shows a side view of the tool holder according to fig. 1;

Fig. 4 shows a top view of the tool holder according to fig. 1 counter to the cutting direction;

Fig. 5 shows a side view of the tool holder according to fig. 1 counter to the advancing direction; Fig. 6 shows a perspective detailed view of a first tool holder;

Fig. 7 shows a perspective detailed view of a second tool holder;

Fig. 8 shows a side view of a tool counter to the cutting direction;

Fig. 9 shows a top view of the tool according to fig. 8;

Fig. 10 shows a further side view of the tool according to fig. 8; and Figs, lla-c each show perspective views of different embodiments of tool holders. Fig. 1 and fig. 2 each illustrate, in a perspective view, a tool holder 10 which can be used in one possible embodiment of the pipe-machining apparatus according to the invention. The tool holder 10 illustrated in fig. 1 and fig. 2 is designed such that two machining tools 40, 50 can be fastened thereto at the same time. A pipe-machining apparatus which has a cutting device together with the tool holder 10, which is illustrated in fig. 1 and fig. 2, is therefore suitable for executing a plurality of pipe-machining steps in one operation.

In the exemplary embodiment of the tool holder 10 illustrated in the drawings, the first tool 40 is designed as a cutting tool which has a corresponding cutting edge 41. Said cutting edge 41 is designed for cutting a groove running in the circumferential direction of the pipe in the pipe casing surface during the machining of a pipe (not illustrated in the drawings) .

On the other hand, the second tool 50 fastened to the tool holder 10 is designed as a tool for metal-removing machining, the second tool 50 having a cutting edge 51 for this purpose.

A pipe-machining apparatus which is equipped with a cutting device which has the tool holder 10 illustrated by way of example in the drawings can be fastened to the pipe to be machined in such a manner that the cutting device can move in the circumferential direction around the pipe to be machined. In this case, the movement of the cutting device in the circumferential direction of the pipe corresponds to the movement in the cutting direction 101, since, during said movement, a groove can be placed into the casing surface of the pipe to be machined by the cutting device or by the cutting edge 41 of the first tool 40.

On the other hand, the cutting device is also movable in the advancing direction 102 relative to the pipe to be machined, and therefore the depth of the groove brought about in the casing surface of the pipe during the movement in the cutting direction 101 can be increased .

Fig. 1 and fig. 2 illustrate the cutting direction 101 and the advancing direction 102 with the aid of corresponding arrows.

It can be gathered in particular from the illustrations in figures 3 to 5 that, in the exemplary embodiment of the tool holder 10, the cutting edge 41 of the first tool 40 moves ahead of the cutting edge 51 of the second tool 50 both in the cutting direction 101 and in the advancing direction 102. It is thereby possible for the formation of the cutting groove and the beveling of the cutting groove to be carried out in one operation since, during a movement of the cutting device in the advancing and cutting directions relative to the pipe to be machined, the first tool 40 which moves ahead of the second tool 50 forms a cutting groove in the casing surface of the pipe whereas the second tool 50 engages in said cutting groove and brings about metal-removing machining of the groove edge.

In order to be able to securely fasten the two tools 40, 50 to the tool holder 10, the tool holder 10 has two receptacles 20, 30. The first receptacle 20, which is illustrated in detail in fig. 6, serves to receive the first tool 40, the first tool 40, in the state thereof in which it is held in the first receptacle 20, being in contact at least in regions by means of a side surface opposite the cutting direction 101 with a receiving surface 21 of the first receptacle 20. On the other hand, the second receptacle 30 (cf. fig. 7) serves to receive the second tool 50, wherein the second tool 50, in the state thereof in which it is held in the second receptacle 30, being in contact at least in regions by means of a side surface opposite the cutting direction 101 with a side surface 32 of the second receptacle 30.

In detail, fig. 6 shows a perspective partial view of the first receptacle 20 counter to the cutting direction 101. As is apparent from fig. 6, the first receptacle 20 has a first receiving surface 21 which is oriented perpendicularly to the cutting direction 101 and parallel to the advancing direction 102. In other embodiments, the first receiving surface 21 may be inclined with respect to a plane which is oriented perpendicularly to the cutting direction 101 and parallel to the advancing direction 102 such that said receiving surface encloses an angle of < 45° with the plane .

As illustrated in fig. 6, the first receiving surface 21 has a threaded bore 25 for receiving a fastening means, in particular a screw 45. Said fastening means 45 serves to fix the first tool 40 in the first receptacle 20.

On a side facing away from the cutting edge 41 of the first tool 40, the first tool 40 is in contact with a side surface 23 of the receptacle 20, wherein said side surface 23 is oriented parallel to the cutting direction 101 and perpendicularly to the advancing direction 102. Said side surface 23 serves to absorb the forces which are exerted on the tool 40 during machining of a pipe and in particular during movement of the cutting device in the advancing direction 102 relative to the pipe such that the fastening means 45 (screw) can be of co respondingly smaller dimensions. As already mentioned, the fastening means 45 serves primarily not to transmit force from the first tool 40 into the tool holder 10 but in order to fix the first tool 40 in the first receptacle 20. As an alternative to the embodiment of the first receptacle 20 illustrated in fig. 6, it is of course conceivable for the side surface 23 to be inclined with respect to a plane which is oriented parallel to the cutting direction 101 and perpendicularly to the advancing direction 102 such that the side surface 23 encloses an angle of < 45° with said plane.

In the case of the first receptacle 20 which is illustrated in fig. 6, the two cheek surfaces 22, 24 of the receptacle 20 are arranged on either side of the side surface 23 and are oriented parallel to the cutting direction 101. The two cheek surfaces 22, 24 are in contact with corresponding surfaces of the first tool 40 and thereby absorb lateral forces which would otherwise result in a rotating movement of the first tool 40 about the fastening means 45. Of course, it is, however, also conceivable for the side surface 23 and the cheek surfaces 22, 24 not to be oriented parallel to the cutting direction 101 but rather to protrude beyond the receiving surface 21.

The first tool 40 is shaped in such a manner that it has surfaces which correspond to the receiving and side surfaces 21, 23 and to the cheek surfaces 22, 24 and form a sheet-like contact with the regions 21, 22, 23 and 24 of the receptacle 20 in the state of the first tool 40 in which it is fastened in the receptacle 20. Furthermore, the first tool 40 is dimensioned in such a manner that it only protrudes slightly beyond the edge 26 of the receiving surface 21 in the advancing direction 102, and the excess length is smaller than the distance between the edge 26 and the threaded bore 25.

As illustrated in fig. 4, the first tool 40 has a bore which is arranged centrally with respect to the longitudinal center axis of the tool 40 and through which the fastening means 45 is guided. In the embodiment illustrated, a screw which is recessed in a depression 44 concentrically with respect to the bore 42 of the first tool 40 is used as the fastening means 45.

The small excess length of the first tool 40 beyond the edge 26 of the receiving surface 21 results, in conjunction with the relatively large distance of the edge 26 from the threaded bore 25, in a small tensile load being exerted on the fastening means 45. In conjunction with the load alleviation provided by the side surface 23 and the cheek surfaces 22, 24, the fastening means 45 can therefore be of relatively small dimensions and can be more easily fastened and released The first tool 40 can therefore be changed in an extremely short amount of time.

Fig. 7 illustrates, in a perspective detailed view, the second receptacle 30 which is formed in the tool holder 10 in order to receive the second tool 50. As illustrated, the second receptacle 30 has a receiving surface 31 which is oriented substantially parallel to the cutting direction 101. As an alternative to this, it is conceivable for the receiving surface 31 to enclose an angle < 45° with a plane oriented parallel to the cutting direction 101. In the embodiment of the second receptacle 30 that is illustrated in fig. 7, the receiving surface 31 has two threaded bores 36, 37 for receiving fastening means 55, 56 (screws) with which the second tool 50 can be fixed in the second receptacle 30. On a side facing away from the cutting edge 51 of the second tool 50, the second tool 50 is in contact with first and second side surfaces 32, 33 of the second receptacle 30. Said first and second side surfaces 32, 33 are formed parallel to the cutting edge 51. In addition, the first side surface 32 is oriented substantially perpendicularly to the cutting direction 101. However, it is also conceivable, of course, for the first side surface 32 to enclose an angle of <45° with a plane oriented parallel to the cutting edge and perpendicularly with respect to the cutting direction 101.

In the embodiment of the second receptacle 30 that is illustrated in fig. 7, the second side surface 33 protrudes over the receiving surface 31 from the first side surface 32. The second tool 50 is in a sheet-like contact with the first and second side surfaces 32, 33 by means of corresponding side surfaces. In this case, the first side surface 32 absorbs the compressive forces which are exerted on the second tool 50 via the tool holder 10 during machining of the pipe in the cutting direction 101 and thereby alleviates the load on the fastening means 55, 56 (screws). The second side surface 33 is also capable, by means of the transmitting arrangement thereof, of absorbing tilting moments which may occur at the second tool 50 during the cutting operation. Two side surfaces 34, 35 which form a stop for the second tool 50 are provided on a side of the second receptacle 30 that faces the first receptacle 20. In detail, in the embodiment of the second receptacle 30 that is illustrated in fig. 7, the side surface 35 is arranged perpendicularly to the receiving surface 31 and side surface 32, wherein the side surface 34 connects the receiving surface 31 to the side surface 35 at an oblique angle. As an alternative thereto, it is also conceivable, however, for the side surfaces 32 and 33 to be arranged in such a manner that they and therefore also the cutting edge 51 of the second tool 50 are mounted further upstream in the cutting direction 101 towards the first tool 40 such that, during the beveling operation, owing to the oblique plane formed by the cutting edge 51, the force acting counter to the cutting direction 101 exerts a force component on the second tool 50 perpendicularly to the cutting direction 101 and presses the second tool 50 against the side surface 35.

In the illustrated embodiment of the tool holder 10, the second tool 50 has two bores 52 which are arranged centrally along an axis of symmetry and through which the fastening means 55, 56 are guided. The fastening means 55, 56 are preferably screws which are recessed in the depressions 54 of the fastening bores 52 of the second tool 50.

As illustrated in figures 8 to 10, the second tool 50 is preferably designed in such a manner that it has surfaces which correspond to the receiving and side surfaces 31, 32, 33, 34 and 35 and which are in sheet- like contact with said receiving and side surfaces 31 to 35 when the second tool 50 is accommodated in the second receptacle 30. The special arrangement of the receiving and side surfaces 31 to 35 of the second receptacle 30 leads to the forces acting on the second tool 50 during metal-removing machining, such as, for example, during beveling, to be primarily absorbed by the side surfaces 32 to 35 of the second receptacle 30 and to only a relatively small loading of the fastening means 55, 56 occurring. For this reason, the fastening means 55, 56 can be of corresponding smaller dimensions, which also makes it possible, inter alia, to change the second tool 50 within a very short period of time.

The first receptacle 20 is preferably arranged on the tool holder 10 on the region mounted furthest upstream in the advancing direction 102 and in the cutting direction 110, as a result of which it is ensured that first of all the cutting edge 41 of the first tool 40 enters the pipe to be machined. Similarly, the first receptacle 20 with the first tool 40 is mounted upstream in the cutting direction 101 from the second receptacle 30 with the second tool 50 such that it is ensured that the second tool 50 only bevels the pipe edge which has already been cut off.

In order to clarify the relative arrangement of the tools 40, 50 to each other, the subsidiary line 103 is drawn in fig. 4, said subsidiary line running in the advancing direction 102 and making contact with that border of the first tool 30 which extends furthest in the direction of the second tool 50 perpendicular to the advancing direction 102 and cutting direction 101. The second receptacle 30 and the second tool 50 are mounted downstream of the first tool 50 counter to the cutting direction 101. The cutting edge 51 encloses the bevel angle with the subsidiary line 103 and, at increasing distance from the subsidiary line 103, is also at an increasing distance from the first tool 40 counter to the advancing direction 102. The cutting edge 51 of the second tool 50 is in contact with or intersects the subsidiary line 103. Similarly, that end of the cutting edge 51 of the second tool 50 which faces away from the subsidiary line 103 is at a greater distance from the subsidiary line 103 in comparison to the tool holder 10, and therefore the cutting edge 51 protrudes from the second receptacle 30 beyond the tool holder 10, thus ensuring that, over the entire width perpendicularly to the advancing direction 102 and cutting direction 101, only the tools 40, 50 come into contact with the pipe to be machined and no part of the tool holder 10 is damaged by contact with the pipe.

The tools 40, 50 may be designed as indexable tips which, after rotation about an axis of symmetry, can again be fastened in their respective receptacle 20, 30 and in each case bring a different cutting edge into contact with the pipe to be machined, thus increasing the service life of the tool. The present invention is not restricted to a pipe-machining apparatus which has the tool holder 10 which is illustrated in the drawings and is described above. On the contrary, individual combinations of the invention disclosed herein are conceivable .

Figures lla-c each illustrate, in a perspective view, different embodiments of tool holders 10 which are suitable for use in the pipe-machining apparatus according to the invention. The tool holder 10 illustrated in fig. 11a substantially corresponds to the tool holder already shown above with reference to the illustrations in figures 1 and 2. In order to avoid repetitions, reference is made to the previous explanations .

The tool holder 10 shown in fig. lib differs from the tool holder shown in fig. 11a in that the second tool 50 which is accommodated in the second receptacle 30 differs from the second tool 50 which is accommodated in the associated receptacle 30 of the tool holder 10 according to fig. 11a. In detail, in the embodiment of the tool holder 10 as is illustrated in fig. lib, the second tool 50 has a shorter cutting edge 51 in comparison to the second tool according to fig. 11a. The tool holder 10 shown in fig. 11c substantially corresponds to the tool holder shown in fig. lib, but, in the embodiment illustrated in fig. 11c, the second tool 50 is accommodated at a different position in the second receptacle 30. This is possible in particular by the second receptacle 30 of the tool holder 10 having a plurality of threaded bores 36, 37, 38 and 39 which are spaced apart from one another and are formed in the side surface 31 in order to receive corresponding fastening screws 55, 56.

Accordingly, the tool holder 10 is also suitable for receiving differently designed second tools 50.

Claims

Patent Claims

1. Pipe-machining apparatus with a cutting device, wherein the cutting device is movable relative to a pipe to be machined in an advancing direction (102) running radially with respect to the centre longitudinal axis of the pipe and in a cutting direction (101) running in the circumferential direction of the pipe, and wherein the cutting device has a tool holder (10) for fastening tools (40, 50) for machining of the pipe, characterized in that a first tool (40) and a second tool (50) are fastened to the tool holder (10) in such a manner that, during the pipe machining, in which the cutting device moves relative to the pipe both in the advancing direction (102) and in the cutting direction (101), a cutting edge (41) of the first tool (40) moves ahead of a cutting edge (51) of the second tool (50) both in the cutting direction (101) and in the advancing direction (102).

2. Pipe-machining apparatus according to Claim 1, wherein the cutting edge (41) of the first tool (40) is designed for cutting a groove running in the circumferential direction of the pipe in the pipe casing surface during the machining of the pipe.

3. Pipe-machining apparatus according to Claim 2, wherein the cutting edge (51) of the second tool (50) is designed for bevelling the groove formed by the cutting edge (41) of the first tool (40) during the machining of the pipe.

4. Pipe-machining apparatus according to Claim 1 or 2, wherein the cutting edge (51) of the second tool (50) is designed for bevelling an end of the pipe during the machining of the pipe.

5. Pipe-machining apparatus according to one of the preceding claims, in particular according to Claim 3 or 4, wherein the cutting edge (51) of the second tool (50) encloses an acute angle with the advancing direction (102) .

6. Pipe-machining apparatus according to one of the preceding claims, wherein the tool holder (10) has a first receptacle (20) for receiving the first tool (40), the first tool (40), in the state thereof in which it is held in the first receptacle (20), being in contact at least in regions by means of a side surface opposite the cutting direction (101) with a receiving surface (21) of the first receptacle (20) .

7. Pipe-machining apparatus according to one of the preceding claims, wherein the tool holder (10) has a second receptacle (30) for receiving the second tool (50), the second tool (50), in the state thereof in which it is held in the second receptacle (30) , being in contact at least in regions by means of a side surface opposite the cutting direction (101) with a side surface (32) of the second receptacle (30) .

8. Pipe-machining apparatus according to one of the preceding claims, wherein the vertical projections of the cutting edge (41) of the first tool (40) and of the cutting edge (51) of the second tool (50) onto the surface of the pipe to be machined at least partially overlap in the extent of said surface along the longitudinal axis of the pipe.

9. Pipe-machining apparatus according to one of the preceding claims, wherein the vertical projection of the tool holder (10) onto the surface of the pipe to be machined falls into a region which is limited in the extent thereof along the longitudinal axis of the pipe by the extent of the vertical projection of the cutting edge (41) of the first tool (40) and by the extent of the vertical projection of the cutting edge (51) of the second tool (50) .

10. Pipe-machining apparatus according to one of the preceding claims, wherein the first and/or second tool (40, 50) are/is fastened releasably to the tool holder (10) .

11. Pipe-machining apparatus according to one of the preceding claims, wherein the first and/or second tool (40, 50) are/is fastened to the tool holder (10) with the aid of at least one screw (45, 55, 56) in each case .

12. Pipe-machining apparatus according to Claim 10, wherein the screw head of the at least one screw (45, 55, 56) is recessed in a depression (44, 54) formed in the associated tool (40, 50) .

13. Pipe-machining apparatus according to one of the preceding claims, wherein the first tool (40) and/or second tool (40, 50) are/is designed as an indexable tip in such a manner that the tool (40, 50), in the rotated state, is fastenable again to the tool holder (10), and in particular is insertable in the associated receptacle (20, 30) of the tool holder (10) .

14. Pipe-machining apparatus according to one of the preceding claims, wherein the tool holder (10) is designed in such a manner that different, second tools (50) are fastenable thereto.