Aisan Kogyo Kabushiki Kaisha

Yukihiko Yato

Hisashi Yamamoto

A pump unit may include a pump configured to increase a pressure of diesel fuel and discharge the diesel fuel to a fuel passage in which a filter is disposed, and a controller configured to control an operation of the pump. The controller may be configured to execute freeze avoidance control in which the operation of the pump is controlled using an index that indicates a degree of clogging of the filter caused by the diesel fuel freezing. In the freeze avoidance control, the controller may be configured to apply a higher load to the pump as the degree of clogging of the filter indicated by the index is higher.

Pump unit

When the duty command value is less than or equal to a threshold value, the motor control device performs the complementary PWM control, and when the duty command value is greater than the threshold value, it sets, for the first element, a first period in which the first element remains turned on and a second period in which control is performed with a corrected duty cycle to turn off the first element for a longer period, and performs average PWM control of which average duty cycle in a total period of the first and second periods is same as a set duty cycle. The motor control device turns on the second element while the first element is turned off in the second period.

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Obu, Japan

Yukihiko Yato