Mitsubishi Electric Corporation

Oval Corporation

Hajime Iida

Kenji Ogawa

Hiroshi Gokan

Koji Atsumi

Hirokazu Kuge

Masahito Yoshimoto

A plurality of power supply circuits include a second power supply circuit for a CPU included in a control unit and a first power supply circuit for another circuit. An output voltage from the first power supply circuit is higher than an output voltage from the second power supply circuit. A range of input voltage is divided into three levels of voltage sub-ranges in accordance with a requirements specification. When the input voltage falls within a lower level voltage sub-range, both of an output function of the first power supply circuit and an output function of the second power supply circuit are stopped. When the input voltage falls within an intermediate level voltage sub-range, the output function of the first power supply circuit is stopped. When the input voltage falls within an upper level voltage sub-range, all circuits are controlled so as to operate.

Electric power steering apparatus

In an electric power steering device assisted by a brushless motor, an induced voltage from a brushless motor is detected when a main power supply is off. The motor is determined to be in a high rpm state when the induced voltage is in a first transient state from a voltage&#x2264;a high rpm detection threshold Th1 to a voltage&#x2265;Th1, thereby setting an intermittent excitation cycle of a revolution angle sensor connected to the motor to a short cycle. The motor is determined to be in a low rpm state when the induced voltage becomes a voltage&#x2265;a high rpm detection threshold Th2 after a wait period corresponding to an electrical angle between peaks or valleys of an output voltage has elapsed in a second transient state from a voltage&#x2265;Th1 to a voltage&#x2264;Th2, thereby setting the cycle to a long cycle.

Electric power steering device

A prover includes a measurement cylinder; a hydraulic cylinder coupled with a side of a downstream end of the measurement cylinder; a measuring piston that moves through a predetermined distance from an upstream side toward a downstream side through the measurement cylinder to eject a reference volume of fluid; and a piston rod that is movably accommodated in the hydraulic cylinder, and has the measuring piston and the piston rod separately constructed. The prover includes measurement standby position stop means, and when returning the measuring piston to a predetermined measurement standby position, the piston rod moves the measuring piston from the downstream side to the upstream side and the measurement standby position stop means stops the measuring piston at the predetermined measurement standby position, after which only the piston rod is caused to move from the upstream side to the downstream side and is accommodated in the hydraulic cylinder.

Piston prover

A piston prover comprises a measurement cylinder; a hydraulic cylinder coupled with a downstream end of the measurement cylinder; a measuring piston that moves a predetermined distance through the measurement cylinder during a measurement due to a fluid flow to eject a reference volume of fluid; and a piston rod that is movably in the hydraulic cylinder, wherein the measuring piston and the piston rod are separately constructed. When returning the measuring piston to a predetermined upstream measurement standby position, the piston rod moves the measuring piston to set the measuring piston at the predetermined measurement standby position, and thereafter only the piston rod is moved from upstream to downstream and is accommodated in the hydraulic cylinder.

Growing community of inventors

Tokyo, Japan

Hajime Iida