DEVICE FOR STABILIZING A WORKPIECE IN A MACHINE TOOL

Abstract

A device for stabilizing a workpiece, in particular a thin-walled workpiece mounted in a machine tool, comprises at least one base; and a plurality of stabilizing elements. The stabilizing elements protrude away from one surface of the base, wherein the stabilizing element comprises a cylinder and a rod arranged therein and the rod can be driven hydraulically to move in the axial direction of the stabilizing element such that the rod of at least two of the stabilizing elements can be brought into contact with one surface of the workpiece.

Claims

1. A device (1) for stabilizing a workpiece, in particular a thin-walled workpiece (4) mounted in a machine tool, comprising: a. at least one base (30); and b. a plurality of stabilizing elements (10) protruding away from one surface of the base, wherein the stabilizing element comprises a cylinder and a rod arranged therein and the rod can be driven hydraulically to move in the axial direction of the stabilizing element such that the rod of at least two of the stabilizing elements can be brought into contact with one surface of the workpiece.

2. The device according to claim 1, wherein the stabilizing element can be pneumatically driven to move in the axial direction of the stabilizing element.

3. The device according to claim 1, wherein the device comprises a first base (30a) and a second base (30b) and a first group of the plurality of the stabilizing elements (10a) arranged on the first base (31) and a second group of the plurality of the stabilizing elements (10b) arranged on the second base (32).

4. The device according to claim 3, wherein when the device is mounted in the machine tool, the stabilizing elements are driven hydraulically and controlled in a way that the first group of stabilizing elements can be brought into contact with a first surface of the workpiece and the second group of stabilizing elements can be brought into contact with the second surface of the workpiece, which is the opposite surface of the first surface of the workpiece.

5. The device according to claim 1, wherein on each base the stabilizing elements are distributed on the surface of the base with equal distances to each other.

6. The device according to claim 1, wherein the stabilizing element comprises a piston (12) arranged inside the cylinder and the rod is mounted thereon to follow the movement of the piston.

7. The device according to claim 6, wherein the piston can be hydraulically pushed into a position that one end of the rod stands out of the cylinder, in particular, a rod head (14) is provided on the top of the rod and can be brought into a direct contact with one surface of the workpiece.

8. The device according to claim 1, wherein an opening (15) is formed on a wall of the cylinder, in particular on the bottom of the cylinder for supplying a hydraulic fluid, in particular oil into the cylinder to act an axial force on the piston.

9. The device according to claim 8, wherein the opening is configured to throttle the hydraulic fluid flowing out of the cylinder when the stabilizing element is brought into contact with the surface of the workpiece, in particular the opening has a funnel shape.

10. The device according to claim 1, wherein the interior of the cylinder is divided by the piston into an upper chamber and a lower chamber, and a ventilation means is operationally connected to the upper chamber and when the ventilation means is activated, air can be supplied from the ventilation means to the upper chamber to force the piston to move to the bottom of the cylinder.

11. The device according to claim 1, wherein the top surface of the base is configure to have a similar shape as the surface of the workpiece, in particular a curved shape.

12. The device according to claim 1, wherein a slave clamping means is provided on at least one end of the base for clamping the device into the machine tool.

13. The device according to claim 1, wherein an automatic clamping element is arranged on the surface of the base opposite to the surface on which the stabilizing elements are provided.

14. A machine tool comprising a master clamping means (50) to clamp the device according to claim 1 in the machine tool, wherein a first fluid channel for supplying the hydraulic fluid and a second fluid channel for supplying the air are embedded in the master clamping means.

15. The machine tool according to claim 14, wherein a main inlet for supplying the hydraulic fluid into the stabilizing elements is integrated in each slave clamping means and the first fluid channel in the master clamping means is directly coupled to the main inlet in the slave clamping means by mounting the device into the machine tool.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] A more particular description of the principles briefly described above will be rendered in the following by reference to specific embodiments thereof, which are illustrated in the drawings. These drawings illustrate exemplary embodiments of the disclosure and are not therefore to be considered to limit its scope. The principles of the disclosure are described and explained with details through the use of the accompanying drawings in which:

[0033] FIG. 1 illustrates a device for supporting a workpiece;

[0034] FIG. 2 illustrates a front view of the stabilizing element;

[0035] FIG. 3 illustrates a section view of the stabilizing element;

[0036] FIG. 4 illustrates one embodiment of the device; and

[0037] FIG. 5 illustrates the device mounted in a machine tool.

EXEMPLARY EMBODIMENTS

[0038] FIG. 1 illustrates a device 1 for stabilizing a workpiece, which is in particular a thin-walled workpiece mounted in a machine tool. In order to machine the thin-walled workpiece it must be stably clamped in the machine tool. The device comprises a base 10 and a plurality of stabilizing elements 10 fixedly mounted on the top surface of the base. In this embodiment, the base has an elongated body and a curved top surface to adapt the shape to the workpiece. By this way, supporting force vertically to the surface of the workpiece can be acted by the stabilizing element. On the top surface of the base, a plurality of holes 4 are provided and each hole receives one stabilizing element. In order to accommodate assemblies for supplying hydraulic and pneumatic fluid into the stabilizing element, the base is designed to be at least partially hollow.

[0039] In this embodiment, the stabilizing elements are provided at three rows. On the each row, more than four stabilizing elements are provided to be able to stabilize a workpiece having a relative larger surface. FIG. 1 shows an example that all the stabilizing elements have the same dimension.

[0040] The structure of the stabilizing element is shown in detail in FIGS. 2 and 3. FIG. 3 is a section view of along the A-A line. Each stabilizing element comprises a cylinder 11 and a piston 12. The cylinder has a tubular shape and two portions formed in one part. The lower portion is a cylinder base 11a for stably mounting the cylinder on the base of the device by fixing means. The upper portion 11b is cylinder body to accommodate the piston therein and stands upwards on the base 30. A piston 12 and a rod 13 formed in one integrated part are arranged in the hollow space inside of the cylinder body to be able to move in the axial direction of the cylinder. The piston and the rod are formed in one single part but have different diameters. The diameter of the piston is designed to correspond to the inner diameter of the cylinder. A piston guide ring 17 and a piston sealing means 16 are provided on the piston. The piston guide ring serves to avoid the mechanical contact between the piston and the inner surface of the cylinder and reduce the lateral force. On the upper part of the interior of the cylinder, a cylinder cap 20 is fixedly mounted on the inner surface of the cylinder to form a closed inner space in the cylinder. The rod protrudes from a through hole in the middle of the cylinder cap. A rod guide ring 22 and a rod sealing means 21 are arranged in a recess formed on the inner surface of the cylinder cap. A rod head 14 having a ball shape is mounted on the top of the rod to be brought into directly contact with the workpiece being machined. The rod head can be made of elastic material. An inlet opening 15 is provided on the cylinder base for supplying the hydraulic fluid into the interior of the cylinder to enable the piston to reciprocate in the axial direction of the cylinder. The interior of the cylinder is divided by the piston into a lower chamber 25 and an upper chamber 24. The rod is arranged in the upper chamber. The hydraulic fluid is received in the lower chamber and push the piston move into the direction of the workpiece.

[0041] Before the machining, a ventilating means, e.g. a nozzle is activated to force the piston to be pushed to an initial position, this means the piston moves to the bottom of the lower chamber on the side of the cylinder base by the air pressure. The ventilating means includes an air chamber 28, which is communicably connected to the upper chamber 24 of the cylinder and separated from the low chamber and upper chamber by a separating means 26, for example a wall . The air chamber can be closed by a closing means. The device is mounted in the machine tool by keeping the piston of all stabilizing elements in the initial position. After the device is mounted in the machine tool and the workpiece is mounted above the device, the ventilating means is deactivated and the lower chamber of all cylinders are supplied by hydraulic fluid to push the piston in the direction of the workpiece. The piston is pushed by the hydraulic fluid in the axial direction to bring the rod head into contact with the surface of the workpiece. When at least a part of rod heads contact the workpiece, the valve to supply the fluid is closed. During the machining, the at least a part of the pistons can be moveable to adapt to the shape variation of the workpiece due to the force generated by the machining tool thereon. After the machining, the pistons are forced to move back to the initial position by activating the ventilating means to dismount the device from the machine tool.

[0042] FIG. 4 depicts an embodiment to stabilize the workpiece from both sides, from the top side of the workpiece and from the bottom side of the workpiece. The device has a first base 30a and a second base 30b. An automatic clamping element 5 is provided one the bottom of the base, namely the opposite side of arranging the stabilizing elements. The automatic clamping element serves for loading the device by a robot. In this configuration, the stabilizing elements of a first group 10a are driven to move downwards to stabilize the workpiece from the top, while the stabilizing elements of a second group 10b are driven to move upwards to stabilize the workpiece from the bottom. On each base, two slave clamping means 31a, 32a, 31b, and 32b are provided on the end of the base for clamping the device into the machine tool. The main inlets for supplying the hydraulic fluid and pneumatic fluid are embedded in the slave clamping means.

[0043] FIG. 5 shows the status in that the device is clamped in the masterclamping means 50, 51 of the machine tool. Fluid channels for supplying the hydraulic fluid and the pneumatic fluid are embedded in the master clamping means but is not visible in FIG. 5. The device is clamped through the 0-point clamp connector to the master clamping means. By mounting the device into the machine tool, through the slave clamping means and the master clamping means, the fluid channels in the master clamping means are coupled directly to the main inlets embedded in the slave clamping means.

[0044] In further, the hydraulic fluid supplied into the first group of stabilizing elements can flows into the second group of stabilizing elements or vice versa, since the main inlets for the first base and the second base can be connected through the fluid channels in the master clamping means.

[0045] In this embodiment, the hydraulic fluid is supplied into the fluid channel in the master clamping means and then distributed into the first group of the stabilizing element through the first main inlet in the first slave means and into the second group of the stabilizing elements through the second main inlet in the second slave means. If during the machining, the force from the workpiece acting on one or more stabilizing elements in the first group are increased, the hydraulic fluid flows out of the lower chamber of the cylinder of these stabilizing elements of the first group and flow further into the stabilizing elements of the second group to adjust the position of the piston of stabilizing elements of the second group.