WATER-JET CUTTING METHOD, WATER-JET CUTTING MACHINE AND WORKPIECE HOLDER

Abstract

A water-jet cutting method, in which a workpiece is cut on a water-jet cutting machine by using a water jet, which can contain abrasive particles, wherein, during the cutting machining, the workpiece to be cut is held on at least two holding surfaces, which are arranged on opposite sides of a passage opening defining a predetermined cutting machining area is provided. The disclosed further relates to a workpiece holder for a water-jet cutting machine and to a water-jet cutting machine having such a workpiece holder.

Claims

1. A water-jet cutting method, in which a workpiece is cut on a water-jet cutting machine using a water jet which can contain abrasive particles, comprising: during the cutting machining, seating the workpiece to be cut on at least two seating surfaces which are arranged on opposite sides of a through-opening which defines a predetermined cutting machining area.

2. The water-jet cutting method as claimed in claim 1, comprising positioning the workpiece prior to the cutting machining in a predetermined position and clamped in this position, wherein the positioning of the workpiece is carried out with reference to a coordinate system of the water-jet cutting machine.

3. The water-jet cutting method as claimed in claim 1, wherein during the cutting machining the workpiece to be cut is held at least between a lower exchangeable plate and an upper exchangeable plate, forming a sandwich arrangement, and in that the sandwich arrangement is pressed in the direction of the seating surfaces, wherein the lower exchangeable plate preferably lies on the seating surfaces.

4. The water-jet cutting method as claimed in claim 3, wherein the lower exchangeable plate is produced from a foamed material, wherein the foamed material comprises foamed plastic.

5. The water-jet cutting method as claimed in claim 3, wherein the upper exchangeable plate produced from a non-foamed plastic.

6. The water-jet cutting method as claimed in claim 3, wherein at least the lower exchangeable plate is positioned prior to the cutting machining in a predetermined position, especially with reference to a coordinate system of the water-jet cutting machine.

7. The water-jet cutting method as claimed in claim 3, wherein a section of the workpiece is cut out, wherein the separating cut is divided into two separating cut sections, and after executing the first separating cut section and prior to executing the second separating cut section, at least the lower exchangeable plate, but preferably both the lower exchangeable plate and the upper exchangeable plate, is/are rotated or replaced by another exchangeable plate of similar type.

8. The water-jet cutting method as claimed in claim 1, wherein a support bracket butts against the underside of the workpiece or against the underside of the sandwich arrangement with supporting effect during the cutting machining.

9. A workpiece holder for a water-jet cutting machine, wherein the workpiece holder has at least two seating surfaces which are arranged on opposite sides of a through-opening which defines a predetermined cutting machining area.

10. The workpiece holder as claimed in claim 9, wherein provision is made for at least one clamping unit which can be transferred into at least one clamping position in which it presses a workpiece, held in the workpiece holder, downward in the direction of the seating surfaces, wherein the clamping unit preferably has a pressure plate of frame like design which at least in the clamping position is arranged above a workpiece to be clamped.

11. The workpiece holder as claimed in claim 9, wherein provision is made for first stops which are designed for the positioning of a workpiece, held in the workpiece holder, within a horizontal plane, wherein the first stops preferably define at least two first stop surfaces which are arranged at a predetermined angle to each other, especially at an angle of 90, wherein the predetermined angle can especially be altered.

12. The workpiece holder as claimed in claim 11, wherein provision is made for a clamping device which is designed for the purpose of pressing a workpiece, held in the workpiece holder, against the first stops, wherein the clamping device preferably has at least two clamping elements which can be moved forward and backward in different directions to each other, especially in directions which are perpendicular to each other.

13. The workpiece holder claimed in either of claim 11, wherein between the seating surfaces and the first stops provision is made for second stops which are arranged in an offset manner in relation to the first stops, wherein the second stops preferably define at least two stop surfaces which are arranged at a predetermined angle to each other, especially at an angle of 90, and which extend especially parallel to stop surfaces of the first stops, wherein the first stop surfaces preferably project inward over the second stop surfaces in the direction of the through-opening.

14. The workpiece holder as claimed claim 9, wherein provision is made for a support bracket which extends at least partially beneath the seating surfaces and has a free end which is arranged on a common level with the seating surfaces, wherein the support bracket preferably has a U-shaped section, wherein oppositely disposed legs of the U-shaped section, of which one defines the free end, preferably have a length of at least 50 cm.

15. A water-jet cutting machine having a workpiece holder as claimed in claim 9.

Description

BRIEF DESCRIPTION

[0028] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0029] FIG. 1 shows a schematic perspective view of a section of a water-jet cutting machine according to an embodiment of the present invention, wherein a jet collecting tank of the water-jet cutting machine is shown transparently for better representation;

[0030] FIG. 2 shows a schematic perspective partial view of a workpiece holder of the water-jet cutting machine shown in FIG. 1;

[0031] FIG. 3 shows a perspective partial view of a workpiece holder shown in FIG. 2, in which are held a lower exchangeable plate and a workpiece; and

[0032] FIG. 4 shows a schematic perspective partial view of the arrangement shown in FIG. 3 in a state in which the workpiece has been machined.

DETAILED DESCRIPTION

[0033] The figures show a section of a water-jet cutting machine 1 according to an embodiment of the present invention or components of this. The water-jet cutting machine 1 comprises a nozzle 2, connected to a high-pressure pump, not shown in more detail, which serves for the purpose of forming a water jet 3 which is generated by the high-pressure pump. The water-jet cutting machine also comprises a jet disperser, in the present case in the form of a parallelepipedal, water-filled jet collecting tank 4. Above the jet collecting tank 4 provision is made for a workpiece holder 5 which is designed in such a way that a workpiece 6 to be machined can be positioned and fixed on it with reference to a machine-dedicated coordinate system 7 which is defined by X-, Y- and Z-axes.

[0034] The workpiece holder 5 comprises a baseplate 8 of frame-like design with a rectangular through-opening 9 which defines a predetermined cutting machining area for machining a workpiece 6 which is held in the workpiece holder 5. Formed on the upper side of the baseplate, at the side of the through-opening 9, are four seating surfaces 10 which in the present case lie opposite each other in pairs and directly adjoin the through-opening 9. For the positioning of a workpiece 6, provision is made for first stop means which in the present case define two first stop surfaces 11 which are arranged on a common level and define an angle of 90 within the X-Y plane. Between the baseplate 8 and the first stop means provision is also made for second stop means which in the present case define two second stop surfaces 12 which extend parallel to the first stop surfaces 11 and also include an angle of 90 within the X-Y plane. Both the first stop surfaces 11 and the second stop surfaces 12 are formed on a separate L-shaped body 13 in this embodiment, wherein the regions of the first stop surfaces 11 which are adjacent to each other as well as those of the second stop surfaces 12 are separated from each other by a groove 14 which extends through the body 13 in the Z-direction and is basically in the shape of an arc in cross section. The workpiece holder 5 also comprises a clamping device 15, in the present case arranged on the upper side of the baseplate 8, with two clamping elements 5 which are arranged at the same height as the first stop surfaces 11 and on sides of the through-opening 9 opposite these, wherein one of the clamping elements 16 can be moved forward and backward in the X-direction and other of the clamping elements 16 can be moved forward and backward in the Y-direction, as is indicated by arrows. Mounted on the underside of the baseplate 8, in a manner to pivot around a Z-axis, is a support bracket of U-shaped design, the free end 18 of which engages in the through-opening 9 and terminates flush with the upper side of the baseplate 8 in the Z-direction. The oppositely disposed legs of the U-shaped section of the support bracket 17 in the present case have a length of at least 50 cm.

[0035] Above the baseplate 8 and the components which are mounted on this, provision is made for a clamping unit 19 which can be transferred into at least one clamping position in which it presses a workpiece 6, held in the workpiece holder, downward in the direction of the seating surfaces 10. The clamping unit 19, which also forms a part of the workpiece holder 5, has a pressure plate 20 of frame-like design which extends within an X-Y plane and by means of pressure elements, not shown in more detail, can be moved upward and downward in the Z-direction, as is indicated by the arrows 21.

[0036] For arranging a workpiece 6 in the workpiece holding device 5, in a first step a lower exchangeable plate 22 is laid upon the seating surfaces 10 and brought into contact with the second stop surfaces 12, as a result of which a defined positioning of the lower exchangeable plate 22 is effected. The lower exchangeable plate 22 in the present case is of parallelepipedal shape and formed from a hard foam, wherein the thickness of the lower exchangeable plate 22 is chosen to be significantly thicker than that of the workpiece 6 and the dimensions of the lower exchangeable plate 22 in the X- and Y-directions are slightly larger than that of the workpiece 6. In a further step, the workpiece 6 is laid on the lower exchangeable plate 22 and brought into contact with the first stop surfaces 11, with which an alignment of the workpiece 6 is associated. After this, the clamping elements 16 are moved in the direction of the workpiece 6 until these press the workpiece 6 tightly against the first stop surfaces 11 and correspondingly fix it. In a subsequent step, an upper exchangeable plate 23, which in the present case is produced from non-foamed polystyrene, is laid upon the workpiece 6, wherein the dimensions of the upper exchangeable plate 23 in the X- and Y-directions correspond in the main to those of the lower exchangeable plate 22 and the thickness is significantly smaller than that of the lower exchangeable plate 22. In a further step, the pressure plate 20 is lowered and pressed onto the upper exchangeable plate 23 until the entire sandwich arrangement, which is formed from the lower exchangeable plate 22, the workpiece 6 and the upper exchangeable plate 23, is clamped with a predetermined pressure between the seating surfaces 10 and the pressure plate 20. After that, the support bracket 17 is positioned beneath the lower exchangeable plate 22, especially in a position in which cutting is not to be carried out. Now, the machining of the workpiece can be carried out, wherein the water jet 3, which discharges from the nozzle 2 and with which by choice abrasive particle can be admixed, cuts through the entire sandwich arrangement and is then collected in the jet collecting tank 4. FIGS. 3 and 4 show by way of example the workpiece 6 after the execution of a first separating cut section 24 and after the execution of a second separating cut section 25 which are carried out in order to cut out an area 26 from the workpiece 6. The workpiece 6 which is shown in FIG. 3 is already provided with the first separating cut section 24. After the execution of this first separating cut section 24 and prior to the execution of the second separating cut section 25, at least the lower exchangeable plate 22 is rotated or replaced by an exchangeable plate 22 of a similar design. Preferably, however, both the lower exchangeable plate 22 and the upper exchangeable plate 23 are rotated or replaced by other exchangeable plates 22, 23 of a similar design. In this way, the effect of the cut out area 26 of the sandwich construction being able to fall into the jet collecting tank 4 after producing the second separating cut section 25 is prevented. The machining accuracy is also increased since the workpiece 6 during separation remains clamped in and positioned. The previously described design of the workpiece holder 5 ensures the reproducible positioning of the workpiece 6 despite the exchange of the exchangeable plates 22, 23.

[0037] Although the invention has been fully illustrated and described in detail by means of the preferred exemplary embodiments, the invention is not limited by the disclosed examples and other variations can be derived therefrom by the person skilled in the art without departing from the extent of protection of the invention. This applies particularly with regard to the specific embodiment and number of the seating surfaces 10, the stop surfaces 11 and 12, the clamping elements 16 and the clamping unit 19. So, for example the angles which include the seating surfaces 10 as well as the stop surfaces 11 can differ from 90 or be variably adjustable. Also, the seating surfaces 10 and 11 do not have to be formed on a separate body 13.

[0038] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0039] For the sake of clarity, it is to be understood that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements.