Denso Corporation

Nippon Soken, Inc.

Tatsuya Kakehi

Noboru Nagase

Kiyoshi Nagata

Tsutomu Nakamura

Norihisa Imaizumi

Yasuhiro Fukagawa

Akihiro Konno

Kenji Matsuda

A motor control device controls a motor. The motor control device is provided separate from the motor. The motor control device includes a switch provided in an electrical conduction path for the motor. The motor control device detects a temperature of the switch. The motor control device controls the switch between an on state and an off state.

Motor control device

A fuel tank lid includes a lid part and a terminal. The lid part includes an inserted part inserted into an opening of a fuel tank, and a storage part storing a drive circuit. The terminal has a central portion covered by the inserted part and the storage part, a first end connected to a pump, and a second end connected to the drive circuit. The storage part includes a side wall that has a first opening and a second opening, an upper closure part that closes the first opening, and a lower closure part that closes the second opening. The fuel tank lid further includes a discharge structure positioned vertically lower than the upper closure part and discharging a fuel vapor that has travelled along an interface between the terminal and the lid part and entered a hollow space of the storage part, to an external atmosphere.

Fuel tank lid and fuel pump module having the same

A driving device for a piezoelectric actuator supplies charges and discharges the piezoelectric actuator through a charging switch and a discharging switch, respectively. The charging switch is repeatedly turned on and off thereby to charge and expand the piezoelectric actuator. The discharging switch is repeatedly turned on and off thereby to discharge and contract the piezoelectric actuator. The discharging switch is kept ON especially during a period from when the discharging switching control is terminated to when the charging switching control is started next. Thus, the piezoelectric voltage at the start of the next driving can be made substantially 0V.

Piezoelectric actuator driving device and method

A power supply voltage booster avoids inadequate step-up capability. In a voltage boosting circuit, a switching device connects and disconnects between the ground potential and one end of the coil, the other end of which is supplied with a supply voltage VB. The switching device is repeatedly turned ON and OFF such that the capacitor is electrically charged from the force in the coil when the switching device is turned off. A charging control circuit turns off the switching device when current flowing through the switching device into the coil is determined to have increased to a switch-off threshold value when the switching device is ON, and turns on the switching device upon determining that the charging current flowing to the capacitor from the coil decreases to a switch-on threshold value when the switching device is OFF. The charging control circuit sets the switch-off threshold value to a larger value as the supply voltage VB is lower. Thus, inadequacy of the step-up capability caused by a drop in the supply voltage VB can be avoided.

Power supply voltage booster

A fuel injection control apparatus drives piezoelectric actuators for opening and closing injectors of respective cylinders based on energy stored in a capacitor of a DC/DC converter. A current detecting resistor for controlling a boost switch to charge the capacitor is disposed at a position at which current flowing through the capacitor is not detected. Further, current detecting resistors for controlling the piezoelectric actuators are disposed at positions at which charging current from a diode to the capacitor is not detected. Thus, the charging of the capacitor can be performed even during the control for charging/discharging the piezoelectric actuator.

Piezoelectric actuator drive device

In a piezoelectric actuator control device for controlling operation of one or more piezoelectric actuators, when receiving a drive signal of a low level, a discharging switch is repeatedly turned on and off in order to discharge electric charge accumulated in the piezoelectric actuator. That is, the discharging switch is kept ON until a discharging current from a piezoelectric actuator reaches a peak threshold value Ip. When the discharging current reaches the peak threshold value Ip, the discharging switch is turned OFF and kept OFF until a discharging current from a piezoelectric actuator reaches a peak threshold value Ip. The device has a threshold value setting circuit for increasing the peak threshold value according to a discharging period of time.

Growing community of inventors

Anjo, Japan

Tatsuya Kakehi