US 5,513,113 AGranted

Method of and device for correcting position of cutting-edge of tool in numerically controlled machine tool

AssigneesMurata Kikai Kabushiki Kaisha, Nissan Motor Co., Ltd.

InventorsYasuaki Okada, Shinji Yoshikawa, Eishiro Urano

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Abstract

A method of and device for correcting a cutting-edge position of a tool installed in a numerically controlled machine. The device includes a CPU which operates a basic processing program, taking a cutting-edge position correction value thereinto, a judging unit for judging whether a temperature of the main spindle table is in a normal condition or an abnormal condition when exchanging the old tool for the new tool, a normal position correcting unit for detecting a movement amount of tool table necessary to bring the cutting-edge of the new tool into contact with a cutting-edge detecting sensor, an abnormal position correcting unit for detecting the movement amount of tool table necessary to bring the cutting-edge of the old tool into contact with the cutting-edge detecting sensor, and cutting ability adjusting unit for memorizing a dimensional change of the work machined as the cutting ability correction value of the tool in the abnormal condition. The normal and abnormal position correcting units memorize a difference between the movement amount including the cutting-edge position correction value on memory at that time and the predetermined standard dimension, as the normal and abnormal cutting-edge position correction value for the new tool, respectively.

Claims5

Dependent claims

A method of correcting a cutting-edge position of a tool installed in a numerically controlled machine having a bed, a main spindle table fixed on the bed, a main spindle rotatably supported by the main spindle table for carrying a work to be machined, a tool table movably mounted on the bed, a tool for machining the work and a cutting-edge detecting sensor mounted on either the main spindle table or the bed for detecting a position of a cutting-edge of the tool, said numerically controlled machine tool being operated in accordance with a basic processing program into which a difference between a movement amount of the tool table and a predetermined standard dimension is provided as a cutting-edge position correction value, the movement amount of the tool table being at a distance necessary to bring the cutting-edge of the tool into contact with the cutting-edge detecting sensor, the method comprising the steps of:

judging whether a temperature of the main spindle table is in a normal condition or an abnormal condition when exchanging an old tool for a new tool;
in the normal condition,
regarding the movement amount of the tool table as a normal movement amount of the tool table having the new tool;
and
providing a difference between the normal movement amount and the predetermined standard dimension into the basic processing program, as the cutting-edge position correction value for the new tool;
or
in the abnormal condition,
regarding the movement amount of the tool table as an abnormal movement amount of the tool table having the old tool;
replacing the predetermined standard dimension with the abnormal movement amount as a newly determined standard dimension;
establishing a difference between the newly determined standard dimension and a position of a cutting-edge of the new tool as the cutting-edge position correction value for the new tool;
regarding a machined dimensional change, which can be obtained from a relationship thereof with wear amount of cutting-edge by preceding experiments, as a cutting ability correction value of the new tool;
and
providing the cutting-edge position correction value for the new tool and the cutting ability correction value thereof into the basic processing program.

10 more elements

A device for correcting a position of cutting-edge of a tool installed in a numerically controlled machine having a bed, a main spindle table fixed on the bed, a main spindle rotatably supported by the main spindle table for carrying a work to be machined, a tool table movably mounted on the bed, a tool for machining the work and a cutting-edge detecting sensor mounted on either the main spindle table or the bed for detecting a position of a cutting-edge of the tool, said numerically controlled machine tool being operated in accordance with a basic processing program into which a difference between a movement amount of the tool table and a predetermined standard dimension is provided as a cutting-edge position correction value, the movement amount of the tool table being at a distance necessary to bring the cutting-edge of the tool into contact with the cutting-edge detecting sensor, the device comprising:

a central processing unit which operates the basic processing program, taking the cutting-edge position correction value thereinto;
judging means for judging whether a temperature of the main spindle table is in a normal condition or abnormal condition when exchanging an old tool for a new tool;
normal position correcting means for detecting the movement amount of tool table necessary to bring the cutting-edge of the new tool into contact with the cutting-edge detecting sensor, the normal position correcting means memorizing a difference between the movement amount of the tool table and the predetermined standard dimension as a normal cutting-edge position correction value for the new tool;
abnormal position correcting means for detecting the movement amount of tool table necessary to bring the cutting-edge of the old tool into contact with the cutting-edge detecting sensor, the abnormal position correcting means memorizing a difference between the movement amount of the tool table and the predetermined standard dimension as an abnormal cutting-edge position correction value for the old tool;
and
cutting ability adjusting means for memorizing a dimensional change of the work machined as the cutting ability correction value of the new tool in the abnormal condition, the dimensional change being obtained from a relationship thereof with wear amount of cutting-edge by preceding experiments.

3 more elements

Dependencies are inferred from the claim text.