Method for processing tubes by cutting with a laser tube cutting machine and laser tube cutting machine

Abstract

The present invention relates to a method and a laser tube cutting machine for cutting a tube (2), comprising: a workpiece transfer device (7) for receiving the tube (2) and transferring the tube relative to a push-through device (10) that supports the tube (2), the tube being guided by clamping jaws (34) of the push-through device (10); a laser processing device (24) associated with the push-through device (10) and having a processing head (17) for directing a laser beam (16) emerging from the processing head (17) onto the tube (2); a tool (33) of the processing device (4) for machining the tube (2), the tool (33) being movable in at least one direction of movement relative to the tube (2); and at least one counter-holder (41) movable to a working position (46) for abutting against the tube (2), the at least one counter-holder (41) acting in a direction opposite to the direction of application of the force of the tool (33). [Selected figure] Figure 2

Description

Technical Field

[0001] The present invention relates to a method for cutting a tube in a laser tube cutting machine, and particularly to a laser tube cutting machine for performing this method.

Background Art

[0002] A laser tube cutting machine and a method for cutting a tube with such a laser tube cutting machine are known from German Patent Application Publication No. 102016106067 (A1). This laser tube cutting machine includes a workpiece moving device that holds a tube to be processed and moves the tube relative to a pushing device that supports the tube. The laser processing device is provided adjacent to the pushing device within the working space. The laser processing device includes a processing head that directs a laser beam onto the tube. In the working space adjacent to the laser processing device, a tool holder for accommodating a tool for machining the tube is also provided. This tool moves along a moving axis perpendicular to the longitudinal axis of the tube and can move towards the tube to be machined relative to the pushing device. During the cutting process of the tube, the tube is held by the clamping jaws of the pushing device. These clamping jaws have elastic energy when exceeding a preset clamping force, but this clamping force will not exceed during the laser cutting process because the force that the pushing device has to absorb does not occur. During machining, a large force exceeding the preset clamping force of the clamping jaws may occur. Due to the elastic energy of at least one clamping jaw, displacement of the tube within the pushing device may occur, which may result in incomplete machining or make machining impossible.

[0003] European Patent No. 2548691 (A1) describes a cutting device for machining a tube. This cutting device includes a catch lance having a clamping opening, and the catch lance is inserted into the tube to be processed during machining of the tube, and the clamping opening of the catch lance is positioned below the cutting point.

[0004] German Patent Application Publication No. 102016104107(A1) describes a workpiece support positioned between a workpiece moving device for receiving and displacing a pipe and a push-through device of a processing machine for cutting the pipe. A similar device is described in Chinese Patent No. 203621737(U).

[0005] A device for clamping a workpiece is known from German Patent Application Publication 102016221227(A1), which includes a workpiece moving device that receives a pipe to be processed, thereby moving the pipe to be processed relative to a pushing device.

[0006] Japanese Patent Publication No. 62-173129(A) discloses a machine for cutting pipes. This clamping device has a chuck that securely clamps the pipe through the chuck. Any lateral forces during machining are absorbed by the clamping force of the chuck. During the machining of the pipe, for example, while inserting threads into the outside of the pipe, a vibration damping device is additionally applied to the inside of the pipe to improve the machining quality. [Overview of the project] [Problems that the invention aims to solve]

[0007] The present invention aims to propose a method for processing pipes with a laser pipe cutting machine, as well as a laser pipe cutting machine itself, which enables further machining of pipes using tools in addition to laser processing. [Means for solving the problem]

[0008] The object of the present invention is solved by a method for cutting a tube in a laser tube cutting machine, wherein the tube is mechanically processed using a tool in addition to laser cutting, and at least one counter holder moves with the tool to a working position for contact with the tube before the machining of the tube begins. This counter holder is movable to the working position and is used to provide support for the tube and to counteract the introduction of force by the tool during machining. The counter holder can absorb forces that cannot be absorbed by the clamping jaws of the push-through device. As a result, both cutting or excising of the tube by laser light and machining of the tube with at least one tool can be performed sequentially in the laser tube cutting machine. Preferably, machining operations such as cutting, circulating drilling, grooving, broaching, grinding, brushing, and threading can be performed.

[0009] Furthermore, at least one counter holder is held stationary in the working position. The counter support absorbs the forces during cutting without elastic energy, regardless of the force the tool applies to the tube.

[0010] In another preferred embodiment of this method, the counter holder is made movable to a working position for contact with the outer surface of the pipe. This makes it easier to move it to the working position from the outside and to the stationary position when not in use.

[0011] Furthermore, the tools used to machine the pipe are fed into the pipe from the outside. Therefore, the counter holder and the machining forces exerted by the tools during machining act on the pipe from the outside, respectively.

[0012] In a more preferred embodiment of this process, the counter holder is positioned at a stationary location away from the pipe during laser cutting of the pipe, and is moved to a working position for contact with the tool before machining of the pipe. This prevents any contamination of the counter holder with burns, slag, etc., during laser cutting.

[0013] When a uniaxial force is applied to a pipe during processing, it is preferable to move a counter holder that cancels out the application of the uniaxial force to the working position. The pipe can then be processed without any displacement. The counter holder can directly absorb the reaction force of the pipe.

[0014] For easy control and force application of the tool to the tube, and for absorption of reaction forces by the counter holder, the counter holder and the tool preferably move along the same axis of movement. According to a preferred embodiment, this axis of movement is perpendicular to the longitudinal axis of the tube.

[0015] When a biaxial force is applied to a pipe by a tool during pipe cutting, it is preferable that the counter holder, which has a gripping device additionally provided to the counter holder, be moved to the working position relative to the pipe. Preferably, the counter holder acts against the introduction of a force in a first direction by the tool. Preferably, the gripping device cancels out the introduction of a force in a second direction perpendicular to the introduction of the force in the first direction by the tool, and as a result, the pipe is fixed by the counter holder and gripping device against the deflection of the two axes, i.e., against the introduction of forces in the first and second directions. Preferably, the first and second force application directions are aligned perpendicular to the longitudinal axis of the pipe.

[0016] In a more preferred embodiment of this method, the counter holder and / or gripping device can each include at least one pressing piece. In this way, reliable contact and absorption of reaction forces can be achieved during machining by the tool.

[0017] Advantageously, the gripping device has two opposing pressing pieces, which move in opposite directions toward the working position to contact the outside of the pipe. The pressing pieces can exert a clamping function on the pipe to fix the initial position of the pipe defined by the push-through device for subsequent machining.

[0018] More preferably, during the machining of the pipe, specifically when the pipe is in a stationary machining position in the workspace, the pressing piece has a point support, a planar support, or a rolling support. Alternatively, a rolling pressing piece can be transported to a counter holder and / or gripping device to contact the pipe. These rolling pressing pieces can be formed from rollers, balls, rolls, etc., and specifically used for machining the pipe, with superimposed lateral movement along the longitudinal axis of the pipe.

[0019] The fundamental objective of the present invention is further solved by a laser tube cutting machine for processing tubes by cutting, the laser tube cutting machine comprising: a workpiece moving device that receives the tube and moves the tube toward a push-through device that supports the tube and guides the tube by the clamping jaws of the push-through device; and a laser processing device having a processing head that directs a laser beam coming out of the processing head onto the tube and having at least one additional tool for machining the tube, the tool being movable in at least one direction of movement relative to the tube, and at least one counter holder being movable to a working position for contact with the tube, the working position acting in the opposite direction to the direction in which the force is applied by the tool. This makes it possible to easily support the tube during the introduction of force by machining on the tube using the tool.

[0020] Furthermore, the counter holder preferably has a drive unit that moves the counter holder to a working position and a stationary position. This allows the counter holder to be positioned as needed to contact and support the pipe. Specifically, the counter holder moves away from the pipe to a stationary position during laser cutting. The drive unit may include a pneumatic or hydraulic cylinder, an electric linear actuator, etc., for controlling lateral movement. The drive unit may also include an integrated lateral guide. Furthermore, the drive unit may be clamped or fixed in an extended position. Thus, the counter holder forms a fixed, immovable contact portion.

[0021] The counterholder preferably has at least one pressing piece, and this pressing piece has a point support, a linear support, a planar support, or a rolling support. Also, the design of the pressing piece may depend on the geometry of the tube.

[0022] Preferably, the pressing piece is made of an elastic material. Thereby, the tube to be processed can be positioned on the counterholder without damaging it.

[0023] According to a preferred embodiment, the counterholder can additionally have a gripping device that cancels the second reaction force, in contrast to the counterholder that absorbs the first reaction force. Specifically, when applying a biaxial force during machining such as milling, the tube can be reliably held by the gripping device. When applying a biaxial force, the counterholder can cancel the first reaction force, and the gripping device can cancel the second reaction force.

[0024] Preferably, the gripping device for absorbing the second reaction force of the tube acts perpendicular to the counterholder that absorbs the first reaction force.

[0025] To position the gripping device on the tube, it is preferable to provide two opposing pressing pieces, and these pressing pieces can be positioned relative to the tube using the clamping force acting on the tube. On the one hand, this allows for easy adaptation to different cross-sections of the tube to be processed. On the other hand, a sufficient clamping force can be applied through the gripping device without causing deformation of the tube.

[0026] Preferably, the pressing piece of the gripping device is movable by a drive unit. This drive unit can be sensor-controlled, and as a result, the clamping force adjusted by the tube can be set.

[0027] The present invention, as well as other advantageous embodiments and further embodiments thereof, will be described and explained in more detail below with reference to the embodiments shown in the drawings. The features cited from the description and the drawings can be applied individually or in any combination according to the present invention.

Brief Description of the Drawings

[0028] [Figure 1] It is a perspective view of a laser tube cutting machine. [Figure 2] It is a schematic side view of a piercing device having a machine tool and a counterholder. [Figure 3] It is a schematic view seen from above of the piercing device according to FIG. 2. [Figure 4] It is a schematic side view of an alternative embodiment of the counterholder of FIG. 2. [Figure 5] It is a schematic side view of a further alternative embodiment of the counterholder of FIG. 2.

Modes for Carrying Out the Invention

[0029] FIG. 1 schematically shows a laser tube cutting machine 1 which is intended for cutting a workpiece 2 which is in the form of a bar, specifically a tube. However, specifically, the outer shape is also to be understood as being in the form of a bar. This laser tube cutting machine 1 comprises a feeding device 3 for feeding the tube 2 to be cut in the laser tube cutting machine 1 laterally, for example by means of a loading device 19. This feeding device 3 feeds the tube 2 to be cut into a working space 20. In this working space 20, the tube is machined by a laser cutting device 24 for laser cutting the tube 2, specifically the bar-shaped part or the tubular part, and / or by a machining device 4 for machining using a tool 33. The tube 2, bar-shaped part or tubular part after machining is received by an ejection device 5 and ejected from the laser tube cutting machine 1. All the essential functions of the laser tube cutting machine 1 are controlled by a numerical control device 6.

[0030] The feeding device 3 comprises a rotary and feeding device that functions as a workpiece moving device 7, a machine bed 8 with guide rails 9, and a push-through device 10. The workpiece moving device 7 is motor-driven and can move in the feeding direction 11 on the guide rails 9. The pipe 2 to be fed is secured by a clamping device 12 of the workpiece moving device 7, which is rotatable in the direction of the two-way arrows 13, surrounding the fed pipe 2 from the outside and clamping it to a stationary position. The pipe 2 is supported by at least one workpiece support 14 integrated with the machine bed 8 while being fed into the push-through device 10 and / or during processing of the pipe 2. In the area of ​​the processing device 4, the workpiece 2 is guided and supported by the push-through device 10. The push-through device 10 is designed so that the clamped pipe 2 is guided in the feeding direction and not clamped to a fixed position. The pipe 2 is rotatable within the push-through device 10 about a rotation axis 13.

[0031] The laser cutting apparatus 24 includes a laser light source 15 for generating laser light 16, a processing head 17, and an optical guide 18 for guiding the laser light 16 from the laser light source 15 to the processing head 17. The laser light 16 exits the processing head 17 and is focused onto the outer surface of the pipe 2 at the processing position F in the workspace 20.

[0032] The tool holder 21 of the machining apparatus 4 is associated with the workspace 20 and / or adjacent to the cutting head 17, and can be moved by the guide 22 (Figure 2) at least within the workspace 20, so that the tool holder 21 with the tool 33 clamped inside can be moved to the machining point F and then removed from the machining point F.

[0033] Furthermore, a magazine 25 can be provided at a distance from the machining point F. This magazine 25 can be designed, for example, as a linear magazine or a turret magazine. Various tools 33, such as drilling machines, circulating drilling machines, tapping tools, or threading tools, can be stored in this magazine 25. The tool holder 21 is preferably movable in the Y direction at least between the magazine 25 and the machining point F, according to the bidirectional arrows 26 shown in the figure. If a linear magazine 25 is used, the tool holder 21 may be further movable in the Z direction. Alternatively, the magazine 25 may also be movable in the Z direction.

[0034] On the side of the pushing device 10, which is located away from the machine bed 8, is a discharge device 5, which discharges part or a portion of the workpiece cut from the pipe 2, as well as the remaining workpiece from the laser tube cutting machine 1.

[0035] Figure 2 shows a schematic side view of the press-through device 10. The press-through device 10 includes a plurality of clamping jaws 34 elastically housed within the press-through device 10. For example, four clamping jaws 34 are provided, which are arranged in pairs facing each other and at a 90° angle to one another. The clamping jaws 34 can be adjusted in relation to their clamping force. These clamping jaws 34 preferably have rollers 35 that contact the pipe 2 and can be used to guide the pipe 2 for laser cutting.

[0036] The counter holder 41 is located within the working space 20. The counter holder 41 includes a drive unit 42 that can move the pressing piece 43 of the counter holder 41 to the working position 46 shown in Figure 2. In this working position 46, the pressing piece 43 is in contact with the outside of the pipe 2. In a stationary position, not shown in more detail, the pressing piece 43 is positioned away from the pipe 2. Preferably, the positioning of the pressing piece 43 to the working position 46 and the stationary position further away is performed by lateral movement along the Y-axis. This lateral movement is controlled by the drive unit 42. The drive unit 42 can be provided by a pneumatic cylinder, a hydraulic cylinder, or an electric linear actuator. The counter holder 41 is controlled by a control device 6.

[0037] According to the first embodiment, the pressing piece 43 can be formed as a surface or a plate. Preferably, the contact surface 47 of the pressing piece 43 may be formed from an elastic material, specifically plastic, to avoid pressure points or scratches. Alternatively, the pressing piece 43 may have a circular or V-shaped edge that is curved in the direction of the pipe 2.

[0038] In Figure 2, the tool 33 is shown in the position just before the machined pipe 2 engages with the tool 33. When drilling a hole, the tool 33 is Y It moves outward along the axis of the tube 2. This results in a uniaxial force acting specifically in the Y direction. The counter holder 41 counteracts the introduction of this uniaxial force with a first reaction force. As a result, when the tool 33 introduces a force greater than the clamping force of the clamping jaws 34, the push-through device 10 can hold the tube 2 in the guide position. The counter holder 41 may be fixedly positioned in the working position 46. For example, the cylinder may have an integrated clamping or locking function for this purpose.

[0039] Figure 3 is a schematic diagram of the pipe-through device 10 with the tool 33 and counter holder 41 positioned relative to the pipe 2. The counter holder 41 engages with the outside of the pipe 2. The tool 33 is similarly fed into the opposite side of the outside of the pipe 2. This arrangement has the advantage of not being limited by the length of the pipe, which would otherwise require positioning inside the pipe using support lances or the like when processing the pipe 2.

[0040] Figure 4 is a schematic side view of an alternative embodiment of the counter holder 41. This counter holder 41 has a gripping device 51 in addition to a pressing piece 43 that counteracts the application of force in the first direction. The gripping device 51 forms a second reaction force that counteracts the introduction of force in a further direction, for example, the Z direction. In the case of machining with biaxial force introduction, such as milling, a second force introduction direction perpendicular to the first force introduction direction can be additionally counteracted.

[0041] The gripping device 51 has, for example, two opposing pressing pieces 43. These opposing pressing pieces 43 can be moved toward each other by the actuator 52 to engage with the outside of the pipe 2. As a result, a three-point support is provided to the pipe 2 using the pressing pieces 43 as counter supports 41. Thus, the pipe 2 can be held in defined positions in the Y and Z directions when force is applied by the tool 33. The force applied by the tool 33 in the X direction is absorbed by the workpiece moving device 7 because the pipe 2 is stabilized by the pressure and tension.

[0042] The actuator 52 of the gripping device 51 can control the tightening function. This tightening function acting on the pipe 2 can be greater than the preset tightening force of the tightening jaws 34. The adjustable tightening force is matched to the inherent rigidity of the pipe 2 in order to avoid deformation of the pipe 2.

[0043] The pressing piece 43 of the gripping device 51 can be designed to be similar to the pressing piece 43 of the counter holder 41.

[0044] Figure 5 shows an alternative embodiment of the counter holder 41 having the gripping device 51 of Figure 4. This embodiment differs in the design of the pressing piece 43. In the embodiment of Figure 5, the pressing piece 43 is formed by a rotatably mounted ball or roller. This has the advantage that, during machining by the tool 33, the workpiece moving device 7 can additionally move the pipe 2 along the longitudinal axis of the pipe 2, specifically in the X direction. In this way, guidance with minimal friction can be achieved. Alternatively, a non-rolling pressing piece made of a material with high sliding properties can be provided and supported.

Claims

1. A method for processing a tube (2) by cutting with a laser tube cutting machine (1), - The pipe (2) to be processed is held by the workpiece moving device (7) and moves in the X direction relative to the push-through device (10) that supports the pipe (2). - The tube (2) is processed by a laser cutting device (24), and during laser cutting, the tube (2) is guided and supported in the Y and Z directions by the clamping jaws (34) of the push-through device (10). - The pipe (2) is further mechanically processed using the tool (33) of the processing device (4), the tool (33) moves at least along the Y direction relative to the pipe (2), - At least one counter holder (41) is moved together with the tool (33) to a working position (46) for contact with the pipe (2) before the start of machining of the pipe (2), - The at least one tool (33) for machining the pipe (2) is fed into the pipe (2) from the outside, - When a uniaxial force is applied to the outside of the pipe (2) by machining using at least one tool (33), at least one counter holder (41) that cancels out the application of the uniaxial force is moved to the working position (46) so as to contact the outside of the pipe (2) at a position opposite to the tool (33), - The counter holder (41) and the tool (33) move along the same axis of movement, and move in opposite directions relative to the outside of the pipe (2), - A method characterized in that, when a biaxial force is applied to the pipe (2) by machining using at least one tool (33), the counter holder (41) and the gripping device (51) additionally provided on the counter holder (41) move to the working position (46) relative to the pipe (2), the counter holder (41) absorbs a first reaction force, and the gripping device (51) absorbs a second reaction force.

2. The method according to claim 1, characterized in that the at least one counter holder (41) is held stationary in the working position (46).

3. The method according to claim 1, characterized in that the at least one counter holder (41) is moved to abut against the outside of the pipe (2) and takes the working position (46).

4. The method according to claim 1, characterized in that the at least one counter holder (41) is positioned at a stationary position far from the pipe (2) during laser cutting of the pipe (2), and is moved to the working position (46) for contact with the pipe (2) before the machining of the pipe (2) using the tool (33).

5. The method according to claim 1, characterized in that the counter holder (41) absorbs a first reaction force, and the gripping device (51) absorbs a second reaction force perpendicular to the first reaction force of the counter holder (41).

6. The method according to claim 1, characterized in that the counter holder (41) and / or the gripping device (51) each include at least one pressing piece (43).

7. The method according to claim 6, characterized in that the gripping device (51) includes two opposing pressing pieces (43) that move in opposite directions to the working position (46) for contacting the outside of the pipe (2).

8. The method according to claim 6, characterized in that, during machining of the pipe (2) using the tool (33) to apply uniaxial or biaxial force, the point-shaped, linear, or planar pressing piece (43) is moved to contact the pipe (2).

9. The method according to claim 6, characterized in that during machining of the pipe (2), specifically during lateral movement of the pipe (2) along the longitudinal axis of the pipe (2), the rolling pressing piece (43) is moved to come into contact with the pipe (2).

10. A laser tube cutting machine for processing a tube (2) by cutting, - A workpiece moving device (7) that moves the pipe (2) in the X direction relative to a push-through device (10) that receives and supports the pipe (2), and guides and supports the pipe (2) in the Y and Z directions by the clamping jaw portion (34) of the push-through device (10), - A laser cutting device (24) is associated with the push-through device (10) and has a processing head (17) that directs a laser beam (16) coming out of the processing head (17) onto the pipe (2), - At least one tool (33) of a machining apparatus (4) for machining the pipe (2), the tool (33) being movable at least in the Y direction relative to the pipe (2) and applying a uniaxial force to the outside of the pipe (2), - The apparatus comprises at least one counter holder (41) which is movable on the same axis of movement as the tool (33) to a working position (46) for canceling out the application of the uniaxial force and contacting the pipe (2), and which acts on the outside of the pipe (2) in a direction opposite to the direction in which the force is applied by the tool (33), A laser tube cutting machine characterized in that the counter holder (41) additionally has a gripping device (51) that acts differently from the reaction force of the counter holder (41).

11. The laser tube cutting machine according to claim 10, characterized in that the counter holder (41) includes a drive unit (42) for moving the counter holder (41) to the working position (46) and the stationary position.

12. The laser tube cutting machine according to claim 10, characterized in that the counter holder (41) is fixed in a stationary state at the working position (46) by a releaseable locking device.

13. The laser tube cutting machine according to claim 10, characterized in that the counter holder (41) has at least one pressing piece (43) which is a point support, a linear support, a planar support, or a rolling support.

14. The laser tube cutting machine according to claim 10, characterized in that the counter holder includes at least one pressing piece made of an elastic material.

15. The laser tube cutting machine according to claim 10, characterized in that the gripping device (51) receives a second reaction force from the tube (2), and the second reaction force is directed perpendicular to the first reaction force of the counter holder.

16. The laser tube cutting machine according to claim 10, characterized in that the gripping device (51) includes at least two opposing pressing pieces (43) that engage the tube (2) with a clamping force.

17. The laser tube cutting machine according to claim 16, characterized in that the pressing piece (43) of the gripping device (51) is movable by a drive unit (52).

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