Fanuc Corporation

Ricoh Company, Ltd.

Fujitsu Fanuc Limited

Hisao Ishii

Yoshiyuki Nomura

Kanemasa Okuda

Masao Kamiguchi

Susumu Ito

Naoki Sato

Akihiko Fujimoto

Susumu Maekawa

Yukio Ogura

Masanobu Takemoto

Takashi Nagatomi

Kunio Kojima

Shinya Okamoto

Hiroshi Araki

Yoshihisa Akiyama

Hiroshi Kamada

The position of a feed shaft is monitored, the mean moving speed and moving frequency of the feed shaft are measured with every unit time for position correction, and a correction amount &dgr;n is determined from the speed and frequency according to an approximation formula and updated (c and c ). A position correction amount for a commanded position is determined from this correction amount, and the commanded position is corrected by the position correction amount (c to c ). The position correction amount for the commanded position is determined from this correction amount, and the commanded position is corrected by this position correction amount. Since the correction amount is determined according to the approximation formula, thermal displacement correction can be effected at all times without requiring any sensor. When the correction amount changes substantially (c ), the thermal displacement is measured by means of a sensor and used as the correction amount (c and c ), whereby accuracy is improved. The frequency of measurement by means of sensors is reduced, so that the machining time can be reduced.

Apparatus and method for thermal displacement correction for a machine tool

A method of correcting thermal displacement error in a driving system of a machine tool comprises forming a heat distribution model including the driving system, and finding an amount of drive in the driving system in the heat distribution model, estimating a heating value supplied to the heat distribution model depending upon the amount of drive, estimating a temperature distribution state in the distribution model by finding a time variation of heating value in the heat distribution model receiving supply of the estimated heating value, finding an amount of heat displacement in the driving system depending upon the temperature distribution state and finding a correction value for thermal displacement correction depending upon the amount of thermal displacement. It is thereby possible to correct the thermal displacement error in the driving system of the machine tool without a detector.

Thermal displacement correcting method of machine tool

Automatic tool changer

Tool exchange system for machining tools

When cutting workpiece into a desired number of closed loop configurations by means of a wire-cut, electric discharge machine provided with an automatic wire feed mechanism, electric discharge machining is started from a machining start hole made in the workpiece corresponding to each closed loop configuration and is performed to a point where the electric discharge machining operation is stopped, thus a part of the closed loop configuration is left uncut. After fixing at least one portion of each closed loop configuration to the workpiece and inserting the wire electrode into the machining start hole by the automatic wire feed mechanism, the electric discharge machining operation is resumed to cut off the remaining uncut part. In the case of the wire electrode breaking during the electric discharge machining operation, the wire electrode is inserted by the automatic wire feed mechanism into the machining start hole and is moved to the position where it breaks along the route where the machining operation has already been performed, and then the electric discharge machining operation is resumed.

Wire-cut, electric discharge machining method

A wire-cut, electric discharge machining method in which a wire is inserted into a machining start hole made in a workpiece to start electric discharge machining from the machining start hole, a bushing of a conductive material is pressed into a hole made in the workpiece to provide the machining start hole.

A curved reflector is disposed behind an elongated lamp for reflecting light from the lamp onto a document carrier in the form of a narrow elongated beam. The carrier is movable perpendicular to the beam for scanning a document placed on the carrier. One or more orifices are formed through the back of the reflector and a blower creates an air flow through the orifice and around the lamp for cooling the same.

Scanning light source

Growing community of inventors

Tokyo, Japan

Hisao Ishii