Jtekt Corporation

Tomohiro Niwa

Masashi Fuji

Satoru Mikamo

Hiroshi Kawamura

Toshihiro Takahashi

Yuichi Toyama

Toshiaki Murakami

Hiroyuki Takahashi

Shigetoshi Yamaguchi

Takaya Tanikawa

Fumihiro Kawakami

Yoshinobu Muramoto

Naoki Kinouchi

Junya Honda

Hiroki Maeda

Kenichi Toyozumi

Takahito Hashimoto

Masato Saijo

Kosuke Tsukahara

Masataka Tsujihashi

A motor controller includes individual drive circuits, a plurality of energization systems, and a processing circuit that outputs a plurality of individual control signals. The processing circuit executes a first calculation process, a second calculation process, a third calculation process, and a fourth calculation process for each of the energization systems. The first calculation process is a process of calculating individual current command values. The second calculation process is a process of calculating the estimated temperatures of protection targets. The third calculation process is a process of calculating individual limit values. The fourth calculation process is a process of calculating the individual control signals based on the individual current command values that are limited by the individual limit values. The processing circuit calculates the estimated temperatures of the protection targets where current of a target system flows.

Motor controller

An ECU independently controls power supply to two winding systems in a motor on a per-winding-system basis based on current command values each calculated for a corresponding winding system in accordance with a target assist torque. When a first winding system fails, the ECU transitions from a first state in which the ECU causes the winding groups of the two winding systems to produce the target assist torque to a second state in which the ECU causes the winding group of the other normal winding system to produce the target assist torque. If the current command value for the normal winding system is equal to or below a current threshold value that is set with reference to zero or a value close to zero when the failed winding system recovers to its normal state in the second state, the ECU transitions from the second state to the first state.

Vehicle control apparatus

A vehicle control apparatus capable of protecting a pre-charge circuit is provided. When a voltage has entered an operating voltage range, a microcomputer determines whether a preset period has elapsed from then. Upon determining that the preset period has elapsed, the microcomputer starts initial check. To carry out the initial check, the microcomputer starts charging a capacitor for power supply stabilization of a drive circuit by turning on the pre-charge circuit and, when the charging of the capacitor is completed, turns on a power supply relay provided on a power supply line that connects between a battery and the drive circuit.

A first microcomputer is configured to identify the cause (a content of the abnormality) of a communication abnormality based on a combination of whether communication through a first communication line is established, whether communication through a second communication line is established, and whether a second clock is normal. Specifically, the first microcomputer separately determines whether the communication abnormality between the first microcomputer and a second microcomputer is simply due to an abnormality in the first communication line and the second communication line, or due to stop of a function of the second microcomputer. The second microcomputer is configured to identify the cause of the communication abnormality based on a combination of whether the communication through the first communication line is established, whether the communication through the second communication line is established, and whether a first clock is normal.

Motor control device

When one of two winding systems fails, an ECU transitions from a first state in which a target assist torque is produced using winding groups of the two winding systems to a second state in which using the remaining normal winding system. When the failed winding system has recovered to normal during an operation in the second state, the ECU carries out initial check that is inspection of the winding system recovered to normal prior to starting the power supply as follows. The ECU omits, from items of the initial check of the winding system recovered to normal, a specific item that is set as an item susceptible to an induced voltage generated in the winding group of the winding system recovered to normal as the motor is driven using the winding group of the normal winding system and carries out only the remainder items of the initial check.

If a B system microcomputer is reset and reactivated while an A system microcomputer is operating normally, tasks of the A system microcomputer and tasks of the B system microcomputer can be synchronized. The B system microcomputer is reset when voltage applied to a battery decreases and falls below an operation guarantee voltage. Thereafter, when the applied voltage becomes equal to or higher than the operation guarantee voltage and the B system microcomputer is activated, the B system microcomputer outputs a request signal for requesting a synchronization signal to the A system microcomputer. The A system microcomputer outputs the synchronization signal synchronized with a periodic task. The B system microcomputer determines an execution timing of the periodic task based on the synchronization signal.

A steering control device capable of suppressing a reduction in reliability even in the case where the redundancy of the power source is increased is provided. A steering ECU includes two control systems in which different external power sources are connected to two drive circuits. The low potential sides of the drive circuits and the low potential sides of the corresponding external power sources are independently connected to each other via power source ground lines for the two control systems. The low potential sides of the drive circuits are connected to each other via an internal ground. Two current detection circuits are provided between the power source ground lines and the internal ground to detect power source ground current values, respectively. The steering ECU includes microcomputers that detect a ground abnormality on the basis of the results of detection performed by the current detection circuits.

Motor control device and steering control device

A wave washer is used for a shaft supporting device of an electric power steering system. The wave washer has an annular portion and six outward protrusions. The annular portion has first protrusions that protrude in a first axial direction and second protrusions that are formed so as to continuous with the first protrusions and that protrude in a second axial direction. Each outward protrusion protrudes from an outer periphery of the annular portion in a radially outward direction of the radial direction of the annular portion.

Wave washer, rotary shaft supporting device including the wave washer, and electric motor including the rotary shaft supporting device

In an electric power steering system, a motor drive controller that has an inverter circuit board and a control circuit board housed in a control case is provided so as to overlap a control case fixation surface formed at an end portion of a gear housing in the axial direction of a steering shaft, so that it is possible to reduce the projection in the axial direction of a motor as compared to the conventional one. In addition, a metallic board is used for the inverter circuit board and the inverter circuit board is fixed to the control case fixation surface so as to be in surface contact therewith, so that it is possible to efficiently dissipate the heat generated on the inverter circuit board into the gear housing and a fixation support plate.

Electric power steering system

A motor includes a cylindrical stator. The stator includes a stator core having teeth, which project inwardly in the radial direction, and coils, which are formed by winding a conductive wire onto each tooth with first and second insulators. The first insulator includes a support extending axially from an outer restriction wall. Each of first to third bus bars is supported by the support of the first insulator in a state in which a main portion is exposed. The main portions of the first to third bus bars are thus in contact with ambient air.

Growing community of inventors

Okazaki, Japan

Tomohiro Niwa