Method for clamping a tool or a workpiece and device for performing the method

Abstract

The invention relates to a method of clamping a tool or a workpiece, using an electric actuator (1) having a housing (2) attached to a work spindle of a machine tool and in which a threaded spindle (3) for moving jaws of a chuck is axially displaceable, and an electric servomotor (4) having a rotor connected with a drive wheel (6) that moves a nut (7) on the threaded spindle (3), a first sensor being associated with the threaded spindle (3) for detecting the axial position thereof, and a second sensor being associated with the spindle nut (7) for detecting the axial position thereof, and including the method step of determining the position of the threaded spindle (3) by the first sensor when a slight axial force occurs due to contact of the clamping jaws with the tool or the workpiece, and continued movement of the spindle nut (7) until a specified sensor difference (12) between the first sensor and the second sensor is determined by the second sensor. The invention further relates to an apparatus for carrying out the method.

Description

technical field [0001] The invention relates to a method for clamping a tool or workpiece with an electric clamp comprising a housing fixed to the working spindle of a machine tool, in which a screw is axially adjustable for adjusting the jaws of a chuck, and also It consists of an electric servo motor whose rotor is in driving connection with the drive wheel of the nut of the adjusting screw, wherein a first sensor for detecting the axial position of the screw is attached to the screw, and a second sensor for detecting the axial position of the nut is attached to the nut. Two sensors, the method comprises the method steps of determining the position of the screw by means of a first sensor when a slight axial force is generated due to the abutment of the jaws against the tool or workpiece, and continuously adjusting the nut until the position of the screw is determined by means of the second sensor. A given sensor difference from the second sensor. The subject of the inventio...

AI Technical Summary

Problems solved by technology

The practical application of the electric gripper disclosed in DE 10 2006 015 918 A1 has already given the aspect to be improved with regard to stroke control, since the analog length measurement by the sensors used is relatively inaccurate

Furthermore, it is problematic to make full use of the motor torque in order to control the clamping force achieved, which likewise involves relatively high inaccuracies

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