EP0703022B1 - Method of clearing a round of metal - Google Patents

Description

The invention relates to a method for splitting a Round plate made of metal, the splitting of the circumference of the round plate from the inside towards a steadily increasing deepening and The gap is widened. The invention further relates to a device for performing the method the preamble of claim 15.

Splitting a round plate made of metal using a splitting roller on a press machine is a well known and common one Forming process in the field of spinning technology (see e.g. BE-A-714 551). This splitting is used to produce rotationally symmetrical parts, for example of pulleys. It is suitable also for press parts with a central hub area. The split is usually at the beginning of a transformation, which is carried out in several steps, with the Split the circumferential area of the round plate into two wings which is followed by further pushing operations or other processing steps can be reshaped. Corresponding the desired or required material distribution on the two wings of the peripheral area the splitting takes place either symmetrically or also asymmetrical.

A disadvantage of the known method of splitting a round plate made of metal by means of a split roller on one Press machine to see that for the splitting process very high Radial forces are exerted on the circular blank have to. Relative, in particular, in the case of blanks from one hand thin and on the other hand relatively hard material, e.g. Steel, this can easily lead to inaccuracies in the course of the gap, which causes deviations from the desired Distribution of material to the wings created during splitting of the circumferential area. The risk is particularly great of such deviations in asymmetrical columns, because here those acting between the split roll and the round blank Forces are unbalanced, causing errors in the splitting process favored. In addition, the split rollers must be made of very hard and therefore expensive material to be made to sufficient To achieve downtimes. Nevertheless, split roles are subject high wear in the known splitting process, which is relatively common post-processing or replacement which requires split rollers.

It is therefore the task of specifying a method for splitting a round blank made of metal and a device for carrying out the method, which enable a higher accuracy of the splitting process and thus an improved product quality and in which longer service lives of the tools used, in particular those with the round blank interacting roles.

With regard to the method, the object is achieved according to the invention solved in that at least the area of the gap bottom with an energy beam for heating and / or splitting locally is applied.

By using an energy beam at the bottom of the gap largely avoided the high tensions which usually a conventional, purely mechanical one Splitting process occur. The effect of the energy beam can consist on the one hand that this the area of The base of the fissure is strongly heated at a narrowly limited point. This leads to structural softening of the blank material. This prevents the build-up of structural stresses and the occurrence of work hardening. Furthermore enables the softened material is faster and lighter mechanical splitting process.

According to a further aspect of the invention, the energy beam also be selected and set so that this Detach material from the material structure of the round blank, melted or evaporated. With such a very high energy Beam will split, i.e. separating the both halves of the disk, executed by the energy beam itself. Only the expansion is used in this procedure then carried out mechanically.

A preferred embodiment of the method according to the invention is that the energy beam is a laser or is a plasma jet. While a laser beam is high energy A plasma beam also shows light Matter particles on. In contrast to the very precise but elaborate lasers can be done with a plasma beam high energy transfer with relatively little effort can be achieved.

There is a further development of the method according to the invention in that the splitting from the circumference of the round blank inwards towards steadily increasing depth and expansion of the Split occurs and that combined and at the same time by means of thermally effective laser radiation in the gap area locally heated and mechanically split and / or expanded becomes.

Due to the invention simultaneously with the mechanical Exposure to the laser radiation The blank becomes the one required for the mechanical shaping of the blank Effort reduced significantly. Hereby will have all the disadvantages of exercising high forces are avoided and it will be improved Accuracy achieved during the splitting process. The with the invention performed material distributions on the two wings of the split circumferential area the round blank can thus be a desired one or approach the required distribution much better. This also leads to an improved quality of the the further deformations produced workpieces. At the same time are for splitting and / or expanding the round blank rolls lower hardness can be used or alternatively essential extended service life of the rollers achievable, which saves time and costs can be saved.

A preferred embodiment of the method according to the invention provides for the heating of the round blank in the gap area through the energy beam until the metal softens takes place and that the round blank in the softened state by a Splitting roll is split and expanded. With this configuration the process of splitting takes place Rounds through the splitting roll, but the splitting process through the softening caused by the energy beam of the metal with much lower forces can.

An alternative preferred embodiment of the method according to the invention suggests that the heating of the round blank in the gap area through the energy beam to liquefaction or Evaporation of the metal takes place and so through the energy beam immediately the gap is generated and that the Gap is widened by an expanding roller. At this The design of the process itself becomes the gap itself generated by the energy beam, so that only a widening of the gap by means of a widening roll is also required is, which causes the mechanical forming forces be reduced to a minimum.

According to a further embodiment, it is advantageous that at least the heated area on the Inert gas is applied to the blank. Through the protective gas becomes the heated or melted area on the blank shielded from the surrounding atmosphere. This will undesirable oxide formation in the melted material avoided. The protective gas can be supplied locally through a nozzle limited supply. Furthermore, the whole Process under a protective gas atmosphere, for example in a protective gas room.

In a preferred embodiment of the invention it is advantageous that the energy beam is a water cutting jet is. By this very fine high pressure water jet Material particles from the blank material for the formation of gaps separated out. In combination with a mechanical expanding roller the water cutting jet performs a defined Direction in the splitting process.

To target the thermal energy by means of laser radiation a desired, relatively small area of the round blank To be able to introduce, it can be provided that a converging focused energy beam is used, the Energy beam itself or the focusing of the energy beam so that the focus is always on the The bottom of the gap is, and the gap is continuously widened is that the focused energy beam is shadow-free reached the bottom of the gap. By using it a converging laser beam will also ensures that areas of the blank or a device, the unintentionally out of focus from the laser beam are only slightly warmed, so that damage or accidents are avoided here.

To avoid that of the energy beam in the round blank introduced thermal energy before contact of the heated Blank area with the split and / or expanding roller drains strongly, it can be provided that in the circumferential direction Ronde seen the energy beam at an angular distance between 10 ° and 90 ° before the splitting or expanding roll meets the round blank. The optimal concrete one in individual cases Angular distance depends, for example, on the speed of rotation the round blank when splitting, according to the thermal conductivity and reflective properties of the metal from which the round plate exists, and according to the power of the laser, and is expediently determined in practice by tests.

The energy beam can essentially be during splitting in the radial direction or alternatively essentially in Tangent direction of the round plate meet this, one another alternative is that the energy beam during splitting at a variable angle on the Ronde hits. Here too, the concrete selection is based the optimal impact angle for the individual application according to the material properties and forming properties the round blank to be formed and is in the Practice can best be determined by experiment.

Around the area on which the energy beam emits thermal energy is introduced into the circular blank, as far as possible the course adapt the gap to be created or just created, it is proposed that an energy beam with a oval or rectangular beam cross-section and one accordingly oval or rectangular focus is applied the longer axis of the oval or rectangle being longitudinal of the gap. While splitting the energy beam is tracked by a tracking device in such a way that the energy beam always focuses on the gap bottom is.

The second part of the task, regarding a device to carry out the process is based on a Device with a spinning machine, which at least one drivable spindle with a chuck to hold the Ronde and at least one at least in the radial direction of the Blank has adjustable slit and / or expanding roll, solved in that at least one device for generation a focusable energy beam is provided, which at least locally applied to the area of the gap base for heating and / or splitting.

The device for carrying out the method is advantageous a known press with conventional Components that are only used to carry out the process to be supplemented with at least one beam generating device is. This addition requires a relatively minor one additional technical effort, which makes the device at relatively low cost to implement the method according to the invention can be enabled.

Preferred arrangements of the split and / or expanding roller and of the laser are given in claims 16, 17 and 18.

Furthermore, it can be provided for the device that this one non-contact, the temperature of which Energy beam hit area of the round blank as well as performance and / or focusing and / or positioning the beam generating device, has controlling and monitoring measuring and control device. By means of such a measuring and control device it is ensured that always for the respective forming required amount of heat exactly in the round blank, in particular is introduced into the gap bottom, so that it not to overheat or too little warming can come.

It is preferably provided that the device Has CNC control and that the aforementioned measuring and Control device is integrated in the CNC control. Today's spinning machines are practically always with one CNC control equipped with relatively little Effort regarding additional measuring devices and additional program parts for the integration of measuring and Control device for the acquisition, control and monitoring the temperature of the one hit by the energy beam Area of the circular blank as well as the power, focus and positioning of the beam generating device can be expanded is.

Preferred embodiments of the invention consist in that as a beam generating device, a laser, a plasma beam generator or a water cutting jet device is provided.

According to an advantageous embodiment of the invention provided that a preheater, especially a Induction system, is provided for heating the blank. The round blank can reach a temperature of several 100 ° C be preheated so that when exposed to a laser beam the desired one without long delays Changes in structure.

In another embodiment it is advantageous that a laser beam generator one or more Laser beams generated at different locations can be conducted via control devices. Through optical Guiding devices such as glass fibers or mirrors can be used in this way Laser beams from a single laser beam generator, for example to several splitting devices according to the invention, be directed. Several laser beams can be used here simultaneously or alternately a single laser beam the different devices. Consequently can be the number of necessary costly laser beam generators be reduced.

An advantageous embodiment of the invention exists also in that on the round blank, especially in the area of A coating to reduce reflection, for example graphite. For an efficient Introducing energy into the workpiece by means of Laser is a low reflection of the laser beam on the Workpiece surface necessary. To reduce reflection according to the invention a coating with a matt and black agent applied. Has been particularly useful graphite powder was found.

Fig. 1

eine erste Vorrichtung zur Durchführung des Verfahrens in schematischer Darstellung und

Fig. 2

zwei geänderte Ausführungen der Vorrichtung ebenfalls in schamtischer Darstellung.

Embodiments of the invention are described below with reference to a drawing. The figures in the drawing show:

Fig. 1

a first device for performing the method in a schematic representation and

Fig. 2

two modified versions of the device also in shameful representation.

FIG. 1 of the drawing shows a press machine Device 1 for splitting a round blank 5. The device 1 has a spindle 2, which is shown in section and which by means of a feed 21, the here is covered, the blank 5 carries torsion-proof.

Furthermore, the device 1 comprises a splitting and expanding roller 3, which is rotatably mounted on a roll holder 31. The axis of rotation 30 of the roller 3 runs parallel to the Axis of rotation 20 of the spindle 2. The roller 3 is with the roller holder 31 on a support 33 in the radial direction of the round blank 5 movable in the direction of the arrow 39. Below the support 33 is part of a machine bed 32 which Device 1 indicated.

Finally, FIG. 1 also shows a laser 4 as Beam generating device on one on the roll holder 31 attached further support 41 in the direction of the movement arrow 49 is movable. By means of the laser 4 a converging energy or laser beam 40 can be generated, which strikes the round blank 5 in a focus 40 '. The laser 4 is with his support 41 over a not shown Adjusting device adjustable so that the laser beam 40th also essentially always in the radial direction of the round blank 5 runs and is aligned with the gap bottom.

When performing the rounding process is a prefabricated blank 5, here a flat, circular metal disc, on the chuck 21 on the Spindle 2 attached and secured against rotation there, for example by means of a counterhold. The spindle 2 is then rotated together with the round blank 5, such as this is indicated by the movement arrow 28. Furthermore the laser 40 is turned on, whereby the laser beam 40 is generated with its focus 40 '. At the same time, the Nip roll 3 by moving the roll holder 31 on the Support 33 delivered to the right to circumference 50 of the round blank 5.

This is due to the laser beam generated by the laser 4 metal forming the round blank 5 on the peripheral region 50 of the round blank warmed and thereby softened, which leads to the circumference 50 delivered split roller 3 comparatively easily into the metal penetrate and can generate a gap 51. Under further rotation of the round blank 5 in the direction of the arrow 28 and further delivery of the split roll 3, which is in the sense of the rotating arrow 38 passively rotates, the gap 51 increases deepened and widened. The fact that the laser 4 on the roller holder 31 of the nip roller 3 sits, the focus 40 'of the laser beam 40 steadily so without further measures tracked that he always on the bottom 52 of the groove 51st meets. This ensures an optimal introduction of the laser beam 40 transferred thermal energy in the peripheral area 50 of the round 5 reached.

Furthermore, the arrangement of the laser 4 in immediate Neighborhood to nip roll 3 by the laser beam 40 transferred thermal energy relatively close to the engagement area the split roll 3 with the circular blank 5 so that a premature heat drain is excluded.

After the above-described creation of the gap 51 can then the blank 5 by means of further reshaping finished workpiece.

Figure 2 of the drawing shows two alternative configurations of the device 1, these alternative configurations differ from the device 1 according to FIG. 1 in that that the laser 4 or 4 'is now independent of the Splitting or expanding roller 3 is movable.

The device 1 according to FIG. 2 is also a spinning machine, which is shown here schematically in sections. The spindle 2 is again in the right part of the illustration recognizable, on which the blank 5 is arranged non-rotatably. To the left of the round blank 5 is the splitting and expanding roll 3 visible on her roll holder 31 by means of the support 33 relative to the machine bed 32 in the radial direction of the Ronde 5 is movable. There is a first one above roll 3 Laser 4 shown here, regardless of the roll holder 31 with its own support 43 in the sense of the movement arrows 49 is movable. The direction of travel is here perpendicular to the direction of travel of the roll holder 31 and selected to the axis of the spindle 2. Farther the position of the laser 4 relative to the round blank 5 is selected such that the laser beam 40 that can be generated by the laser 4 essentially tangentially meets the circumference 50 of the round blank 5.

In the illustration in FIG. 2, the gap 51 is circumferential 50 of the circular blank 5 has already been produced in part, the Laser 40 by moving along its support 43 so it is tracked that the focus 40 ′ of the laser beam 40 always hits the bottom 52 of the gap 51.

An alternative arrangement and orientation is based on a Second laser 4 'shown in the upper right part of Figure 2. In this embodiment of the device 1 is the laser 4 'aligned in the radial direction of the round blank 5 and in its longitudinal direction and in a direction parallel to that laser beam 40 that can be generated by it in the sense of the movement arrow 49 movable. By appropriate tracking of the Lasers 4 'along its own support provided here 43 is achieved in this embodiment that the focus 40 'of the laser beam 40 always on the bottom 52 of the gap 51 hits.

Except with a single laser 4 or 4 'the device can 1 can also be equipped with two lasers 4 and 4 ', if necessary.

By means of the laser beam 40 can with appropriate power not just a softening of the round 5 forming Metal can be achieved, but also if necessary Liquefaction or evaporation in the laser beam 40 or its focus 40 'hit areas. At this The gap 51 in the circumference 50 of the round blank 5 is then executed generated directly by the laser beam 40, then the role 3 here only the function of an expanding role which widens the gap and thus ensures that the converging laser beam 40 even when the Gap 51 without shading to the bottom 52 of the gap 51 can reach. In the last version described are expedient still means for the removal of the liquefied and / or vaporized metal to be provided in the drawing are not specifically shown.

Claims (24)

1. Method for cleaving a circular metal blank (5), in which a cleaving and a mechanical enlarging of the gap (51) takes place from the circumference (50) of the blank (5) towards the inside, characterized in that at least the area of the gap base (52) is locally subject to the action of an energy beam (40) for heating and/or cleaving.
2. Method according to claim 1, characterized in that the energy beam (40) is a laser or plasma beam.
3. Method according to claim 1 or 2, characterized in that the cleaving takes place from the circumference (50) of the circular metal blank (5) towards the inside, accompanied by constantly increasing deepening and enlarging of the gap (51) and that in combination and simultaneously by means of a thermally acting laser radiation, the blank (5) is locally heated and mechanically split and/or enlarged in the gap area.
4. Method according to one of the claims 1 to 3, characterized in that the heating of the circular metal blank (5) in the gap area takes place through the energy beam (40) up to the softening of the metal and that in the softened state the blank (5) is cleaved and enlarged by a cleaving roll (3).
5. Method according to one of the claims 1 to 3, characterized in that the heating of the circular metal blank (5) in the gap area through the energy beam (40) takes place up to the liquefaction or vaporization of the metal and consequently through the energy beam (40) the gap (51) is directly produced and that the gap (51) is enlarged by an enlarging roll (3).
6. Method according to one of the claims 1 to 5, characterized in that at least the heated area on the circular metal blank (5) is subject to the action of inert gas.
7. Method according to one of the claims 1 and 4 to 6, characterized in that the energy beam (40) is a water cutting jet.
8. Method according to one of the preceding claims, characterized in that use is made of a convergent, focussed energy beam (40), the energy beam (40) or the focussing of the energy beam (40) being so tracked that the focus (40') is always located on the base (52) of the gap (51) and in which the gap (51) is so constantly enlarged that the focussed beam (40) passes in shading-free manner to the base (52) of the gap (51).
9. Method according to one of the preceding claims, characterized in that, considered in the circumferential direction of the circular metal blank (5), the energy beam (40) strikes said blank (5) with an angularly spacing between 10 and 90° in front of the cleaving or enlarging roll (3).
10. Method according to one of the preceding claims, characterized in that, during cleaving, the energy beam (40) strikes the circular metal blank (5) substantially in the radial direction.
11. Method according to one of the claims 1 to 9, characterized in that, during cleaving, the energy beam (40) strikes the circular metal blank (5) substantially in the tangential direction.
12. Method according to one of the claims 1 to 9, characterized in that, during cleaving, the energy beam (40) strikes the circular metal blank (5) under a variable angle.
13. Method according to one of the preceding claims, characterized in that use is made of an energy beam (40) with an oval or rectangular beam cross-section and a corresponding oval or rectangular focus (40'), the longer axis of the oval or rectangle being in the longitudinal direction of the gap (51).
14. Method according to one of the preceding claims, characterized in that to the circular metal blank (5), particularly in the area of the gap base (52), a coating is applied, e.g. of graphite for reducing reflection.
15. Apparatus for cleaving a circular metal blank (5), particularly for performing the method according to one of the claims 1 to 13, with a spinning lathe, which has at least one rotatable spindle (2) with a chuck (21) for receiving the circular metal blank (5) and at least one cleaving and/or enlarging roll (3) infeedable at least in the radial direction of the blank (5), characterized in that there is at least one device (4, 4') for generating a focussable energy beam, which locally acts on at least the area of the gap base (52) for heating and/or cleaving.
16. Apparatus according to claim 15, characterized in that the cleaving and/or enlarging roll (3) and the beam generator (4, 4') are located on a common support (33).
17. Apparatus according to claim 16, characterized in that the beam generator (4, 4') is movable relative to the cleaving and/or enlarging roll (3) along an axis running in the longitudinal direction of the beam (40) generatable by it.
18. Apparatus according to claim 15, characterized in that the cleaving and/or enlarging roll (3) and the beam generator (4, 4') are arranged on a separate support in each case and are movable independently of one another.
19. Apparatus according to one of the claims 15 to 18, characterized in that a measuring and control device operating in contact-free manner is provided, which determines the temperature of the area of the circular metal blank (5) encountered by the energy beam (40), as well as determining, controlling and monitoring the power and/or focussing and/or positioning of the beam generator (4, 4').
20. Apparatus according to one of the claims 15 to 19, characterized in that a CNC control is provided and that the measuring and control device is integrated into the CNC control.
21. Apparatus according to one of the claims 15 to 20, characterized in that the beam generator (4, 4') is a laser or plasma beam generator.
22. Apparatus according to one of the claims 15 to 20, characterized in that the beam generator (4, 4') is a water cutting jet device.
23. Apparatus according to one of the claims 15 to 22, characterized in that a preheating device, particularly an induction system, is provided for heating the circular metal blank (5).
24. Apparatus according to claim 21, characterized in that a laser beam generator generates one or more laser beams, which can be guided by guides to different use points.

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