Mitsubishi Denki Kabushiki Kaisha

Yoshihito Itou

Shiro Iwatani

Toshiaki Kashihara

Tatsuki Kouwa

The present invention provides an automotive rotary electric machine enabling brush abrasion limit detection reliability to be increased and stable brush abrasion limit detection indication to be performed. The construction thereof is provided with a detecting terminal for sensing a brush abrasion limit when a brush has abraded to a predetermined length by coming into contact with a coil spring that forces the brush, and a determining circuit constructed so as to compare output from the detecting terminal and a threshold value, to enter an ON state (a brush abrasion limit detection state) once the output exceeds the threshold value, and thereafter to maintain the ON state. Thus, because the ON state of the determining circuit is maintained even if output from the detecting terminal fluctuates due to vibration, noise, etc., false detection of the brush abrasion limit resulting from the fluctuations in the output from the detecting terminal can be prevented.

Automotive rotary electric machine

A system for controlling a vehicular generator, includes: a voltage controlling devicefor adjusting a generator output voltage of a generatorconnected to an in-vehicle batteryto a predetermined voltage, the voltage controlling deviceincluding an external voltage sensing terminal S for detecting an external voltage of the generator, and the generator output voltage being adjusted through on/off control of a field current of the generatorin accordance with the external voltage, in which an external control unitis inserted between the external voltage sensing terminal S and the batteryto cause a voltage drop. Consequently, it is possible to dispense with an exclusive input terminal for external signal, thereby enabling simple system configuration cost reduction.

System for controlling a vehicular generator

The brush abrasion detector is unnecessary to provide any detecting element for detecting limit of abrasion of a brush in the proximity of the brush. The brush abrasion detector includes: a brush located being slidably press-fitted to a slip ring provided at an end portion of a field winding of a generator, and supplying an excitation current from a battery to the field winding; a current detection circuit for detecting a current value flowing through the field winding via the brush; an output voltage detection circuit for detecting an output voltage value from the generator; and a brush abrasion determination circuit for determining abrasion state of the brush based on a current value detected by the current detection circuit or an output voltage value detected by the output voltage detection circuit.

Brush abrasion detector of vehicle generator

A control system for a vehicular generator is provided which can be simplified in construction as the entire system to achieve cost reduction by using only a single control terminal that takes in a control signal from outside and by employing the control signal composed of only three kinds of signals. The system includes a generatorhaving an armature coiland a field coil, a batteryto be charged by a power generation voltage, and a control circuitA that adjusts the power generation voltage by controlling to turn a field current supplied to the field coilon and off in accordance with a battery voltage. A single control terminal C is provided on the control circuitA, and an external control unitis connected to the control terminal C. The external control unitsupplies either one of a ground signal, an open signal and a pull-up signal to the control terminal C as a control signal in accordance with the battery voltage and an operating condition of the vehicle. The control circuitA interrupts the field current to stop power generation in response to the ground signal, adjust the power generation voltage to a first control voltage for normal time in response to the open signal, and adjusts the power generation voltage to a second control voltage higher than the first control voltage in response to the pull-up signal.

Growing community of inventors

Tokyo, Japan

Yoshihito Itou