Mitsubishi Heavy Industries Limited

Mitsubishi Heavy Industries Machine Tool Co., Ltd.

Mitsubishi Heavy Industries Machines Tool Co., Ltd.

Koh Ishii

Katsuyoshi Takeuchi

Kazunari Izawa

A transmission winding portion having a positive-polarity loop and a negative-polarity loop alternately formed so as to partially overlap with each other in the extending direction of a scale, arrangement of the positive-polarity loop and the negative-polarity loop being adjusted such that the positive-polarity loop and the negative-polarity loop on both sides with respect to the intermediate position in the longitudinal direction of the transmission winding portion are inverted; a first reception winding that covers the transmission winding portion in the width direction of the scale, that has a length, corresponding to the cycle of the cycle pattern of the transmission winding portion, and that is formed into a rectangular pattern; a second reception winding having a shape symmetrical to the first reception winding with respect to the intermediate position in the longitudinal direction of the transmission winding portion.

Electromagnetic induction type position detector

Stator electrode for rotation angle detector

A control unit of a linear scale includes: excitation current supplying device for causing excitation currents each having two different angular frequencies to flow through slider coils; sampling device for sampling induced voltage V induced in a scale coil, at a timing of t=(2j+1)&#x3c0;/(2&#x3c9;) (j: an integer); position detecting device for calculating Va(j) which is a sum of samples of the induced voltage at multiple sampling points, calculating an excitation position &#x3b1; at which the Va(j) is equal to 0, and setting the &#x3b1; as a detected position X; and abnormality detecting device for calculating Vb(j) which is a sum of absolute values of the induced voltage at multiple sampling points, comparing the Vb(j) with a threshold value, and determining that the electromagnetic induction type position detector is in an abnormal state when the Vb(j) is equal to or lower than the threshold value.

A communications system for a position detector comprises a position detector for detecting the amount of movement of a table, an A/D converter connected to the position detector, a numerical control device connected to the A/D converter and receiving a position signal converted by the A/D converter, and an information processor connected to the A/D converter via a USB capable of bidirectional communication. The information processor includes a storage section for preserving data and a program, a computing section for computationally operating the program, and a display section for indicating the results of computational operation by the computing section, and the data.

Communications system for position detector

A rotary absolute value scale includes a rotor in which two rotor side coil patterns provided with different pitches are laminated, and a stator in which two stator side coil patterns provided with different pitches are also laminated. A linear absolute value scale includes a slider in which two slider side coil patterns provided with different pitches are laminated, and a scale in which two scale side coil patterns provided with different pitches are also laminated.

Growing community of inventors

Ritto, Japan

Koh Ishii