Grinding machine and method of operating a grinding machine

Abstract

A grinding machine includes a machine bed on which a workpiece spindle with a workpiece holder and a tool spindle with a tool holder are arranged. A workpiece held in the workpiece spindle, relative to a tool held in the tool holder, is displaceable along an X-axis running in a first direction parallel to the surface of the machine bed, is displaceable along a Y-axis, running in a second direction parallel to the surface of the machine bed, is displaceable along a Z-axis running perpendicular to the surface of the machine bed, is rotatable about an A-axis running parallel to the surface of the machine bed, and is rotatable about a C-axis running perpendicular to the surface of the machine bed. The tool spindle is completely kinematically separated from the workpiece spindle. Movements along the X-axis, about the A-axis and about the C-axis being carried out by the workpiece spindle.

Claims

1. A grinding machine (1) with a machine bed (10) on which a workpiece spindle (20) with a workpiece holder (21) and a tool spindle (40) with a tool holder are arranged in such a way that a workpiece held in the workpiece spindle (20), relative to a tool (41) held in the tool holder (40), is displaceable along an X-axis, which is an axis running in a first direction parallel to the surface of the machine bed (10), displaceable along a Y-axis, which is an axis running in a second direction parallel to the surface of the machine bed (10), displaceable along a Z-axis, which is an axis running perpendicular to the surface of the machine bed (10), rotatable about an A-axis, which is an axis running parallel to the surface of the machine bed (10), and rotatable about a C-axis, which is an axis running perpendicular to the surface of the machine bed (10), characterized in that the tool spindle (40) is completely kinematically separated from the workpiece spindle (20), with movements along the X-axis, about the A-axis and about the C-axis being carried out by the workpiece spindle (20) and movements along the Y-axis and along the Z-axis being carried out by the tool spindle (40).

2. The grinding machine (1) according to claim 1, characterized in that the grinding machine (1) has a tool changer (50) which is moveable together with the tool spindle (40) along the Y-axis and/or along the Z-axis.

3. The grinding machine (1) according to claim 2, characterized in that the tool changer (50) is rotatable about a BY-axis, which is an axis parallel to the axis of the tool spindle (40), and is displaceable in a direction along the BY-axis.

4. The grinding machine (1) according to claim 2, characterized in that the tool changer (50) has at least one coolant distributor (53) for cooling a tool (41) held by the tool spindle (40).

5. The grinding machine (1) according to claim 4, characterized in that the coolant distributor (53) is detachably arranged on the tool changer (50) so that the coolant distributor (53) can be replaced.

6. The grinding machine (1) according to claim 4, characterized in that the coolant distributor (53) is also rotated when rotating about the BY-axis.

7. The grinding machine (1) according to claim 1, characterized in that a cabin is arranged on the machine bed (10) which cabin defines a machine interior in which in particular the tool spindle (40) and the workpiece spindle (20) are arranged for machining workpieces and in that the cabin has corner doors through which the machine interior can be accessed.

8. The grinding machine (1) according to claim 1, characterized in that the grinding machine (1) has a robot (60) for changing workpieces.

9. The grinding machine (1) according to claim 8, characterized in that the robot (60) is arranged outside the work area in an automation cabin (61) and in that the workpiece spindle (20) can be moved into the automation cabin (61) on the X-axis, so that the robot arm (60) does not reach into the work area when changing the workpiece.

10. The grinding machine (1) according to claim 9, characterized in that an add-on module (80) is arranged on the machine bed (10), which extends the X-axis and carries the automation cabin (61).

11. The grinding machine (1) according to claim 8, characterized in that, adjacent to the automation cabin (61), there is a palletizing system (70).

12. A method of operating a grinding machine (1) according to claim 1, in which workpieces clamped successively at the workpiece spindle (20) are machined by grinding with one or more tools (41) clamped at the tool spindle (40), characterized in that the workpiece spindle (20) and/or the tool spindle (40) are moved kinematically decoupled from one another to carry out a workpiece change and/or to carry out a tool change.

13. The method according to claim 12, characterized in that the workpiece is changed with a robot (60) arranged outside the work area in an automation cabin (61), in that the workpiece spindle (20) with the workpiece holder (21) and the workpiece is moved into the automation cabin (61) along the X-axis.

14. The method according to claim 13, characterized in that the robot (60) and the workpiece spindle (20) are pre-positioned and the workpiece spindle (20) with the workpiece holder (21) and the workpiece is moved into the automation cabin (61) immediately after machining.

15. The method according to claim 13, characterized in that the A-axis is aligned parallel to or at a defined angle to the X-axis by rotating about the C-axis before it reaches the automation cabin (61).

16. The method according to claim 13, characterized in that, when the next workpiece to be machined is picked up, the movement in the direction of the X-axis needed for removing the workpiece from the workpiece holder (21) of the workpiece spindle (20) and/or for inserting the next workpiece into the tool holder (21) of the workpiece spindle (20) takes place by moving the workpiece spindle (20) along the X-axis.

17. The method according to claim 12, characterized in that the following steps are carried out during a tool change: gripping the tool holder with a gripper (52), releasing the spindle clamp, lifting the tool (41) by moving it parallel to the BY-axis, rotating the tool changer (50) about the BY-axis to the position of the new tool (41), inserting the new tool (41) by moving it parallel to the BY-axis, tightening the spindle clamp, opening the gripper (52).

Description

[0044] The invention is explained in more detail below with reference to figures that represent exemplary embodiments.

[0045] In the figures:

[0046] FIG. 1 shows a view of an exemplary embodiment of a grinding machine with the cabin removed, and

[0047] FIG. 2 shows a top view of components of the grinding machine of FIG. 1 in combination with an optional automation by a robot and a palletizing system

[0048] FIG. 1 shows an exemplary embodiment of a grinding machine 1 in which the cabin has been omitted for an unobstructed view of the work area of the grinding machine 1. Also not shown in FIG. 1 is a modular automation and palletizing system that can optionally be added to grinding machine 1 and is included in FIG. 2.

[0049] A machine bed 10, which is manufactured for the benefit of high accuracy in molding technology using mineral casting for improved vibration damping, carries workpiece spindle 20 and tool spindle 40.

[0050] Furthermore, machine bed 10 has integrated cable ducts, a gravity-driven drain with an outlet where an optional screen is placed, for coolant and lubricant, integrated pipes for lubrication, motor cooling, process cooling and grounding, and integrated level monitoring, which are not visible in the representation of FIG. 1 because they are covered by other components.

[0051] Workpiece spindle 20, whose workpiece holder 21, shown in FIG. 1 without a workpiece held therein, defines the horizontally running A-axis of grinding machine 1, is integrated in a T-slot table 22 which is displaceable horizontally along the X-axis and can be rotated about the vertically running C-axis on a carriage 23. Carriage 23 runs on rails which are arranged on machine bed 10 and which, like the linear motor which drives carriage 23 and the direct, absolute measuring system which monitors its position, are located under cover 24 and are therefore not visible in FIG. 1.

[0052] Tool spindle 40, which is shown in the representation of FIG. 1 with a tool 41 in the form of a grinding wheel pack held therein, is carried by a carriage 42 which is displaceable along the Z-axis in the vertical direction on a rail system arranged vertically on a further carriage 43, which rail system defines said vertical Z-axis, and which, like the drive and the position monitoring of carriage 41, is not visible because it is located under cover 44.

[0053] Further carriage 43 in turn runs on rails which are arranged on machine bed 10, and which, like the linear motor which drives further carriage 43 and the direct, absolute measuring system which monitors its position, are located under cover 45 in FIG. 1, and are therefore not visible. These rails define the Y-axis, which runs perpendicular to the X-axis and is also horizontal.

[0054] Accordingly, it is clearly apparent that in the case of grinding machine 1, tool spindle 20 is completely kinematically separated from workpiece spindle 40, with movements along the X-axis, about the A-axis and about the C-axis being carried out by workpiece spindle 20 and movements along the Y-axis and along the Z-axis being carried out by tool spindle 40.

[0055] Carriage 42 also carries a tool changer 50, which in this case is designed for a total of four tools, of which only tool 41 held by the tool spindle 40 at this time, is shown in FIG. 1 in order to show the setup of tool changer 50 in the figure in more detail.

[0056] Tool changer 50, which is, as a result, moved together with the tool spindle in the direction of the Y-axis and in the direction of the Z-axis, has a carrier plate 51 with four arms of equal length arranged in the shape of a cross, at the end of which a gripper 52 is arranged, which gripper, in the equipped state, carries a tool 41, in particular a grinding wheel pack. The carrier plate is rotatable about a driven BY-axis running parallel to the Y-axis; moreover, it can be moved in a direction parallel to this axis in the direction towards the viewer in FIG. 1.

[0057] This allows tool 41 held by tool spindle 40 during grinding to be gripped with associated gripper 52 when a tool change is necessary, and to lift it parallel to the BY-axis by a linear movement, which in FIG. 1 runs towards the viewer, after the spindle clamp has been released. Thereafter, the tool changer can be rotated, for example, 90° so that the next tool held by gripper 52 of the next arm is positioned to be inserted parallel to the BY-axis into the tool holder of tool spindle 40 by linear motion, which in FIG. 1 is in the direction away from the viewer, to activate the spindle clamp and then release it with gripper 52 in order to be able to continue machining. During processing, this gripper 52 thus remains in a position in which it only has to be closed the next time the tool is changed in order to grip tool 41 to be changed. In this way, a very quick tool change is possible because only minimal travel distances have to be covered.

[0058] Another special feature of tool changer 50, which is shown in FIG. 1, is the replaceable coolant distributors 53 associated with each of the arms and grippers 52, respectively. As can be seen in FIG. 1, coolant distributor 53 of each tool 41 held in tool spindle 40 is aligned in such a way that the coolant and lubricant needed can be sprayed directly to the desired location during the grinding process. Because coolant distributors 53 are replaceable, a coolant distributor 53 optimized for the grinding process with this tool can be set up directly even when tool changer 50 is equipped with different tools 41, together with each tool 41, which leads to a considerable improvement in cooling and lubrication. Advantageously, a sensor is provided on tool changer 50 in each case, which monitors whether an associated coolant distributor 53 is present and properly connected or not.

[0059] FIG. 2 shows a top view of components of grinding machine 1 of FIG. 1 in combination with an optional automation by a robot 60 and a palletizing system 70. Here, the entire setup that carries tool spindle 40 and the tool changer, as well as covers 24, 44 and 45 have been omitted so that additional detail of the machine bed, particularly the rails defining the X-axis and Y-axis, can be seen.

[0060] As can be seen in FIG. 2, robot 60 embodied as a robot arm is arranged in an automation cabin 61 which is open to the machine interior, which at this point is not delimited by a section of a cabin wall. Automation cabin 61 and robot 60 are carried in this case by an add-on module 80 arranged on machine bed 10, which add-on module 80 extends the X-axis, and the rail system that defines it, respectively, as can be deduced from the position of workpiece spindle 20 shown in the workpiece changing position and the T-slot table 22 carrying it, and carriage 23.

[0061] Palletizing system 70 is located on the side of the robot 60 opposite T-slot table 22. Accordingly, robot 60 can deposit machined workpieces in palletizing system 70 with a simple pivoting movement, grip a new workpiece blank to continue machining and feed it to the workpiece spindle 20 without reaching into the machine interior or the work area. It is particularly advantageous if the movement of robot 60 is designed in such a way that robot 60 is pre-positioned with its workpiece gripper in such a way that, when the finished workpiece is transferred, carriage 23 moves a section of the workpiece still held in workpiece holder 21 into the opened workpiece gripper of robot 60, which then grips it before it is released and when the next workpiece blank is transferred to workpiece spindle 20, carriage 23 moves a section of the workpiece still held in the workpiece gripper of robot 60 into open workpiece holder 21 of workpiece spindle 20, which then fixes it with an expansion chuck, for example, before the workpiece gripper of robot 60 lets go. Since the movement of carriage 23 along the X-axis is faster and more precisely controlled than that of robot 60, time is not only saved, but transfer errors are also effectively avoided.

LIST OF REFERENCE NUMERALS

[0062] 1 grinding machine [0063] 10 machine bed [0064] 20 workpiece spindle [0065] 21 workpiece holder [0066] 22 T-slot table [0067] 23 carriage [0068] 24 cover [0069] 40 tool spindle [0070] 41 tool [0071] 42 carriage [0072] 43 carriage [0073] 44 cover [0074] 45 cover [0075] 50 tool changer [0076] 51 carrier plate [0077] 52 gripper [0078] 53 coolant distributor [0079] 60 robot [0080] 61 automation cabin [0081] 70 palletizing system [0082] 80 add-on module