Automatic tool changer

The invention relates to a tool changing device according to the preamble of claim 1.

For machine tools tool change devices are known in which a gripper takes out the tool from the tool base holder and a new begins. A built-in the machine tool clamping unit, the tool is off and clamped. The loosening and tightening of the tool is carried out by hand.

The patent application EP-A-01 25 529 a tool changing device is described in which the clamping screw is operated by a stationary mounted on the machine tool machines: On the machine tool, a tool holder receptacle is provided with a central bore into which a having a cylindrical portion to attack a change arm PROVIDED tool holder can be used. The tool holder is connected via a clamping unit with clamping screw with the tool holder. The cylindrical portion of the tool holder having a radial threaded bore. At the free end of an operationally independent of the machine tool changing arm is a motorized drivable connection pin having a fitting into the threaded bore of the cylindrical portion of the tool holder external threads. To replace the tool the connecting bolt of the changing arm is automatically screwed into the radial threaded bore of the tool holder. The threaded bore and the connecting pins are connected by prismatic centering recesses at the outer end of the replaceable head precisely positioned with each other. By fixedly mounted on the machine tool motor-driven screwdriver, the clamping screw is loosened in the chuck. The tool is withdrawn by the change arm and an identical alternate head arranged diametrically opposite the old change head on the change arm mounted. Subsequently, the clamping screw is tightened by the screwdriver.

It is a disadvantage of this device is that the replacement and releasing or clamping the tool is performed by means of two separate apparatuses. For the fixed position on the machine screwdriver not all machine tools is sufficient space. Another disadvantage of the tool exchange device described is that required for left and right die assemblies correspondingly modified versions of this device. The tool changing device is therefore not universally applicable. Finally, another disadvantage of the system that no more than two seats are provided for interchangeable heads on the changer arm. In machine tools with tool holders for several interchangeable heads by the tool change times are considerably longer.

A tool changing device according to the preamble of claim 1 is described in EP-A-0213399. This has a moveable relative to a transverse to the axis of the tool holder, rotatably mounted holder for a plurality of gripper hands, as well as a rotationally drivable screwdriver, which protrudes in the direction of the tool holder and during movement of the holder in the alignment position against an opening provided at the tool holder holding screw for the tool encounters and coupling means for rotating the retaining screw.

The invention has for its object to provide a tool changing device for a machine tool, are connected with the replaceable head and tool holder by an automatic clamping unit with integrated clamping screw that the automatic cancellation / tensioning and replacing axially or radially disposed to the machine axis tools through a single, of the machine tool independent device allows left and right die assemblies can operate alike.

This object is achieved by the listed in claim 1 characteristic combination.

Further developments of the invention are listed in the dependent claims 2 to 10th

In a specific embodiment, is located on a multiaxially movable lifting carriage, a rotatably mounted pivot arm. An associated drive enables clocked movement of the pivot arm to any angle. At the free end of the pivot arm, a gripper holder is arranged with at least four tool stations. In the swing arm also a Spannbitwelle is integrated, which is provided at both ends with a profile that can transmit torques. This Spannbitwelle can be moved axially so that it may be coupled to both the left and right with the clamping screw of the tool holder.

An embodiment of the subject invention is set forth in Figures 1 to 4, namely: FIG. <dl id="dl0001"><dt>FIG. 1a, b</dt><dd>the lifting carriage and the arm of the tool changer with gripper holders and Spannbitwelle in two different views,</dd><dt>FIG. 2</dt><dd>a vertical section through the plane II-II in Fig. 1, and</dd><dt>FIGS. 3 and 4</dt><dd>the tool change in schematic form.</dd></dl>

The tool changing device shown in Fig. 1 consists of a lifting carriage 1, on which a swiveling arm 2 is mounted. The arm carries a gripper holder 4 and is penetrated by the Spannbitwelle. 5 The operating independently of the machine tool lifting 1 can be moved in two or three axes. The fixed thereto pivot arm 2 has a square cross section and is rotatably mounted about the axis 6th The robotic arm can perform rotational movements of 2 x 180 °, preferably 4 x 90 ° or any other angle. The drive for the swivel arm can be advantageously integrated in the lifting. At the lower end of the swing arm is mounted on one of the four sides in the vertical direction about the axis 7 rotatable gripper holder. 4 The gripper holder is equipped with at least four tool grippers. 8 In the horizontal plane perpendicular to the axis 7 of the pivoting arm of a motor-driven, axially movable Spannbitwelle 5 is penetrated. The Spannbitwelle has at both ends a profile 9, can transmit torques.

In FIG. 2 is a cross section through the lower part of the swivel arm 2 with Spannbitwelle 5, the associated drive 10, 11 and of the device for the axial movement 12, shown thirteenth The engine 10 triebt via an intermediate shaft 11 to the Spannbitwelle fifth The engine is preferably equipped with an adjustable maximum torque for clockwise and anticlockwise rotation. The device for the axial movements consists of a compressed air connection 12 and a spring 13. When the compressed air connection 12 supplied with compressed air, the chamber 14 is filled with air and the Spannbitwelle 5 pushed to the left against the force of the spring 13 from the swivel arm second Stop the flow of compressed air, which is 5 Spannbitwelle pushed back by the spring 13 in the position shown. By limit switches 15 and 16 respectively desired axial position of Spannbitwelle is detected.

The tool change with the inventive device is shown in Fig. 3 and 4.

As can be seen in Fig. 3, the arm 2 moves so closer to the machine tool, that the tool head located in the tool holder 17 can be taken 18 from the gripper 8. The tool head is clamped. The Spannbitwelle 5 is engaged axially at slow rotation. After the coupling process, the tool holder voltage is achieved by the relaxing torque.

From Fig. 4 it can be seen that the Spannbitwelle 5 axially disengaged from the clamping position and the tool head 18 is separated by axially displacing the tool holder 17 or the gripper plate 19 from the tool holder 17. The gripper plate is then rotated and placed and braced a new tool in reverse steps.

The particular advantage of the present invention is that when changing tools devices in which the clamping screw of the automatic clamping unit is in the tool holder, the tool change can be carried out with an arm, are integrated into the gripper and clamping unit. By this device, the tool change can be carried out fully automatically with an operationally independent of the machine tool unit.

It is a further advantage of the device according to the invention that allowed by the rotatable mounting of the swiveling arm, the swiveling movement to any desired angle, both axially and radially arranged to the machine axis of tool stations can be reached. In connection with the inventively designed Spannbitwelle that allows particular to actuate both left and right tool holder changing systems, all in a plane angularly arranged in different toolholder systems are therefore operated in practice.