Device for water-jet cutting and scoring

Abstract

The present invention relates to a water-jet cutting device comprising a table (1) for supporting a workpiece (4), and comprising a machining head (3) which is movable relative to the table (1) and has a nozzle (11) in order to direct a high-pressure water jet onto the workpiece (4). The aim of the invention is that of providing efficient machining. This aim is achieved in that a scoring wheel (16) is additionally provided on the machining head (3).

Description

[0001] WATERJET CUTTING AND SCORING DEVICE

[0002] The present invention relates to a water jet cutting device comprising a table for supporting a workpiece and a machining head which is movable relative to the table and which has a nozzle for directing a high-pressure water jet onto the workpiece.

[0003] Cutting plate-shaped workpieces using high-pressure water jets is known. The workpieces are placed or clamped on a table, and a machining head is moved across the workpiece along the planned cutting line. Typically, the table is stationary, and the machining head is mounted on a carriage that moves back and forth on a bridge along a horizontal axis (y-axis). This, in turn, can be moved relative to the table along another horizontal axis (x-axis), allowing the workpiece to be scanned in two dimensions. The relative movement between the machining head and the table is essential. The plane spanned by the x-axis and the y-axis is parallel to the plane of the table and thus typically also parallel to a workpiece placed or clamped on the table, such as a tile. One such solution is described, for example, in WO 2011 / 098067 A.

[0004] Such waterjet cutting devices make it possible to precisely cut tiles, for example, even with complex geometries. However, the possible cutting speed is limited, so the practical application of this process is often not advisable due to capacity and cost constraints.

[0005] The object of the invention is to develop a water jet cutting device in such a way that the rapid processing of a large number of workpieces is possible.

[0006] According to the invention, these above objects are achieved by additionally providing a scoring wheel on the machining head. Problem analysis has shown that a large proportion of the cuts to be made, for example in tiles or floor slabs, are simple and straight. This makes it possible to first score the workpieces and then break them along the scored edge. Scoring can be carried out at a significantly higher feed rate than cutting with a water jet. This makes it very flexible to make straight and simple cuts by scoring and then breaking at high speed, while cuts with more complex geometries, for example round cutouts, can be made precisely using water jet cutting. The particular advantage of the solution according to the invention is that these two operations can be carried out without repositioning orcan be performed on the same workpiece in one setup, if necessary. Of course, the device according to the invention also makes it possible to cut a first workpiece with only the water jet or to scratch another workpiece only, if necessary.

[0007] Preferably, the scoring wheel is arranged in the machining head so that it can move in a direction perpendicular to the plane of the table, i.e., along a generally vertical z-axis. In this way, the scoring wheel can be moved toward the workpiece without adjusting the height of the machining head, and it is particularly possible to scan the surface of the workpiece with the scoring wheel.

[0008] Preferably, the machining head is movable in both a first direction and a second direction parallel to the table. Alternatively, it is also possible for the machining head's mobility to be achieved by moving the table in the x-direction and the machining head in the y-direction, which is advantageous for particularly long workpieces. However, a fixed table is generally preferred because the moving masses are smaller. In particular, it is advantageous if the machining head can be moved in the second direction on a bridge that is movable relative to the table in the first direction.

[0009] Preferably, the machining head consists of a base unit and a rotating part that is rotatable relative to the base unit about a machining axis, which is preferably perpendicular to the plane of the table. This makes it possible to achieve a multi-axis movement of the nozzle that is advantageous for machining, while simultaneously allowing the scoring wheel to be rotated in such a way that it rolls correctly along the workpiece.

[0010] A particularly preferred embodiment of the invention provides that the nozzle can be pivoted relative to the rotating part about a tilting axis that intersects the machining axis at an acute angle, for example, 45°. In this way, the nozzle, which is normally oriented perpendicular to the plane of the table, can be moved into an inclined position. This makes it possible to cut bevels or, in the case of thicker workpieces, to correct cutting angle errors that may result from the expansion of the jet.

[0011] A compact and rigid design is achieved by attaching a scoring wheel holder directly next to the nozzle on the turned part. It is particularly advantageous if the scoring wheel is located in a plane that contains the machining axis. This naturally causes the contact force of the scoring wheel to act in the plane that contains the machining axis, so that any deformation caused by this force also occurs in this plane. Therefore, such deformation does not impair machining accuracy.

[0012] Preferably, an actuator is provided for moving the scoring wheel towards the table, which actuator is designed to press the scoring wheel onto the workpiece with a predetermined force. The actuator typically comprises at least one pneumatic cylinder for driving the wheel. This makes it possible, in particular, to implement a design in which the actuator has at least three modes: an idle mode, in which the scoring wheel is arranged away from the workpiece; a scanning mode, in which the scoring wheel is pressed onto the workpiece with low force without machining it; and a scoring mode, in which the workpiece is scored. This means that the scoring wheel can also be used as part of a positioning device that detects the distance between the nozzle and the workpiece. Precise determination of the distance is particularly important when the nozzle is tilted, since a change in the distance causes a lateral offset.

[0013] The distance between the nozzle and the workpiece is preferably detected by providing a displacement sensor to detect the movement of the scoring wheel in the direction of the table.

[0014] The present invention also relates to a method for machining workpieces, in which at least one waterjet cut and at least one machining operation in which the workpiece is scored are performed in a single clamping setup. In this context, the term "clamping" refers to both mechanical fixation by conventional clamping elements and, for sufficiently heavy workpieces, a support position, provided there is no risk of them moving relative to the table during machining.

[0015] Preferably, before a waterjet cut, the scoring wheel is lowered onto the workpiece in a scanning mode and the distance traveled is recorded. If it can be assumed that the surface of the workpiece is parallel to the plane of the table within narrow limits, as is the case with good quality tiles, for example, then this one-time measurement is sufficient for the entire machining process. If this is not the case, then during a waterjet cut the scoring wheel should be lowered onto the workpiece at predetermined intervals in a scanning mode and the distance traveled is recorded. For the most demanding requirements, however, it is also possible for the scoring wheel to be lowered continuously onto the workpiece during a waterjet cut and the distance traveled is recorded. In this case, it is necessary to guide the rotating part in such a way that a rolling movement of the scoring wheel is ensured.

[0016] In order to facilitate the breaking of the workpiece after machining, it is preferably provided that each machining operation is carried out in a straight line.

[0017] The invention will now be explained in more detail with reference to the exemplary embodiments illustrated in the figures. They show:

[0018] Fig. 1 shows a water jet cutting device according to the present invention in a front view;

[0019] Fig. 2 shows the water jet cutting device of Fig. 1 in a side view;

[0020] Fig. 3 shows a detail A of Fig. 2;

[0021] Fig. 4 shows the water jet cutting device from Fig. 1 to Fig. 3 in a plan view.

[0022] The water jet cutting device according to the invention shown in Fig. 1 to Fig. 4 basically consists of a table 1 arranged horizontally in the position of use, a bridge 2 movable along the x-axis and a processing head 3 movable along the y-axis on the bridge 2. A workpiece 4, for example a tile, is placed or clamped on the table 1.

[0023] The machining head 3 consists of a carriage 5 which can be moved in the y-direction, a base unit 6 which can be moved relative to the carriage 5 along the z-axis, i.e. vertically in the position of use, and a rotating part 7 which can be rotated relative to the base unit 6 about the z-axis.

[0024] The rotating part 7 is angled and has a bearing section 8, which accommodates the bearing 8a for the rotatable mounting relative to the base unit 6, and a receiving section 9, which is angled at an obtuse angle to the bearing section 8. A holder 10 with a rod 10a, which carries a nozzle 11, is rotatably attached to the receiving section 9. The holder 10 can rotate about a tilt axis 12, which intersects the z-axis at an angle of approximately 45°. In the normal position, which is shown in Fig. 2 and Fig. 3, the axis 13 of the nozzle 11 coincides with the z-axis. This means that the water jet emerging from the nozzle 11, which processes the workpiece 4, hits the workpiece 4 perpendicularly along the z-axis.

[0025] If the holder 10 is rotated from its normal position about the tilt axis 12, the nozzle 11 pivots with its axis 13 out of the plane spanned by the z-axis and the axis 12 of the holder 10, whereby, however, the intersection point 14 of the axis 13 of the nozzle 11 with the tilt axis 12 of the holder 10 remains unchanged and still lies on the z-axis, which thus also represents the machining axis. Ideally, the height of the base unit 6 and thus of the nozzle 11 is adjusted so that the intersection point 14 lies exactly in the plane of the workpiece 4, so that when the holder 10 is rotated, there is no lateral displacement of the point at which the water jet strikes the workpiece 4.

[0026] A scoring wheel holder 15 is detachably attached to the side of the bearing section 8 of the rotating part 7. At its lower end, a scoring wheel 16 is arranged, pneumatically extendable by an indicated actuator 17 in the form of a pneumatic cylinder. A displacement sensor 18 detects the movement of the scoring wheel 16 relative to the scoring wheel holder 15.

[0027] In an idle mode, the scoring wheel 16 can be retracted into the holder 15 and thus be inactive. In a scanning mode, the scoring wheel can be pressed onto the workpiece with a small force to detect the distance to the workpiece 4 without damaging it. This allows, as described above, the intersection point 14 to lie exactly in the plane of the workpiece 4. In a scoring mode, the workpiece is scored by applying a greater force while simultaneously moving the machining head 3 over the workpiece.

[0028] The plane of the scoring wheel 16, which is the drawing plane in Fig. 2 and Fig. 3, also contains the z-axis, ie the movement of the machining head 3 also takes place along this plane.

Claims

PATENT CLAIMS 1. Water jet cutting device with a table (1) for supporting a workpiece (4) and with a processing head (3) which is movable relative to the table (1) and which has a nozzle (11) for directing a high-pressure water jet onto the workpiece (4), characterized in that a scoring wheel (16) is additionally provided on the processing head (3).

2. Water jet cutting device according to claim 1, characterized in that the scoring wheel (16) is arranged in the processing head (3) so as to be movable in a direction z perpendicular to the plane of the table (1).

3. Water jet cutting device according to one of claims 1 or 2, characterized in that the processing head (3) is movable both in a first direction x and in a second direction y parallel to the table (1).

4. Water jet cutting device according to claim 3, characterized in that the processing head (3) is movable in the second direction y on a bridge (2) which is movable in the first direction x relative to the table (1).

5. Water jet cutting device according to one of claims 1 to 4, characterized in that the processing head (3) consists of a base unit (6) and a rotating part (7) which is rotatable relative to the base unit (6) about a processing axis z, which is preferably perpendicular to the plane of the table (1).

6. Water jet cutting device according to claim 5, characterized in that the nozzle (11) is pivotable relative to the rotating part (7) about a tilting axis (12) which intersects the machining axis z at an acute angle.

7. Water jet cutting device according to one of claims 5 or 6, characterized in that a scoring wheel holder (15) is attached to the rotating part (7) directly next to the nozzle (11).

8. Water jet cutting device according to one of claims 5 to 7, characterized in that the scoring wheel (16) lies in a plane which contains the machining axis z.

9. Water jet cutting device according to one of claims 1 to 8, characterized in that an actuator (17) for moving the scoring wheel (16) in the direction of the table (1) which is designed to press the scoring wheel (16) onto the workpiece (4) with a predetermined force.

10. Waterjet cutting device according to claim 9, characterized in that the actuator (17) of the scoring wheel holder (15) has at least three modes: an idle mode in which the scoring wheel (16) is arranged away from the workpiece (4); a scanning mode in which the scoring wheel (16) is pressed onto the workpiece (4) with low force without machining it; and a scoring mode in which the workpiece (4) is scored.

11. Water jet cutting device according to one of claims 9 or 10, characterized in that a displacement sensor (18) is provided for detecting the movement of the scoring wheel (16) in the direction of the table (1) together with the workpiece (4).

12. Method for machining workpieces, in which at least one water jet cut and at least one machining operation in which the workpiece (4) is scored are carried out in one clamping.

13. Method according to claim 12, characterized in that before a water jet cut, the scoring wheel (16) is lowered onto the workpiece (4) in a scanning mode and the distance of the lowering is recorded.

14. Method according to one of claims 12 or 13, characterized in that during the execution of a water jet cut, the scoring wheel (16) is lowered onto the workpiece (4) at predetermined intervals in a scanning mode and the distance of the lowering is recorded.

15. Method according to one of claims 12 or 13, characterized in that during a water jet cut the scoring wheel (16) is lowered continuously onto the workpiece (4) and the distance of the lowering is recorded.

16. Method according to one of claims 12 to 15, characterized in that each machining operation is carried out in a straight line.

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