Honda Motor Co., Ltd.

Makito Nakasone

Koji Nakamura

Masamichi Harada

Kyohei Sakagami

Shigeji Nakano

Norihiro Akiyoshi

In a hydraulic control device switchable between a first state in which a first oil is supplied from a first pump to a hydraulic operation part via a bypass valve and a second state in which the first oil supplied from the first pump is pressurized by using the second pump and the pressurized first oil is supplied, as a second oil, to the hydraulic operation part, control that adds a correction hydraulic pressure of a predetermined amount to the hydraulic pressure of the oil discharged from a valve for adjusting the pressure of the oil supplied to the hydraulic operation part is performed when the second state is switched to the first state due to a stop or a low rotation state of the second pump.

Hydraulic control device

The disclosure provides a hydraulic control device capable of suppressing an excessive increase in the rotation speed of a second pump and stabilizing the discharge pressure of the second pump. The target rotation speed of the second pump for making a pressure value of a first oil close to an estimated value of a pressure value of a third oil is calculated, and a feedback amount with respect to the target rotation speed is calculated by subtracting the estimated value of the pressure value of the third oil from the pressure value of the first oil detected by a hydraulic sensor. Time regions for performing calculation of the feedback amount include an update region in which the feedback amount with respect to the target rotation speed is updated, and a hold region in which update of the feedback amount with respect to the target rotation speed is temporarily stopped.

Provided is a hydraulic control device in which in the rotation control of the second pump, the required discharge pressure of the second pump can be more reliably maintained below a predetermined pressure in the control that keeps the target rotation speed constant after the feedback control ends. In the rotation control of the second pump, in the control which keeps the target rotation speed constant after the feedback control ends, the rotation of the second pump is controlled by adding a predetermined addition rotation speed to the target rotation speed corresponding to the required discharge pressure. Since the required discharge pressure of the second pump can be maintained below a predetermined pressure in the fixed mode by the addition rotation speed, it can reliably obtain the effect of reducing the work load of the first pump and contribute to the improvement of the fuel efficiency of the vehicle.

The disclosure provides a hydraulic control device. The operating/stopping of the second pump is determined based on a value of a difference between a reduced work rate of the first pump when the second pump is operated and a power consumption of the second pump. In a state where the second pump is stopped, the power consumption of the second pump is calculated based on an estimated value of a pressure of oil supplied to the hydraulic operation part and an estimated value of a pressure of oil supplied from the first pump to another hydraulic operation part or a lubrication target operating at a lower pressure than the hydraulic operation part. In a state where the second pump is operated, the power consumption of the second pump is calculated based on an actual rotation speed and an actual torque of the second pump.

In a hydraulic control device switchable between a first state in which a first oil is supplied from a first pump to a hydraulic operation part via a bypass valve and a second state in which the first oil supplied from the first pump is pressurized by using the second pump and the pressurized first oil is supplied, as a second oil, to the hydraulic operation part, when the second pump is stopped in the second state, control that gradually decreases a target rotation speed of the second pump is performed, and rates at which the target rotation speed of the second pump decreases differ in a case where the second pump is stopped in an operation-allowed region and in a case where the second pump is stopped when the second pump is determined as in an operation-disallowed region.

In a hydraulic control device, a state determination unit of a control unit determines whether a second pump is in a boosting operation or in a transition state. If the state determination unit has determined that the second pump is in the boosting operation or in the transition state, a valve-opening detection unit determines whether a check valve is opened. If the valve-opening detection unit has determined that the check valve is opened, a controller stops the second pump or decreases the rotation number of the second pump.

In a hydraulic control device, a hydraulic sensor is provided on an intake side of a second pump where first oil is taken in and a line pressure sensor is provided on a discharging side of the second pump where the second oil is discharged. A control unit controls driving of the second pump by controlling a motor on the basis of an output pressure detected by the output pressure sensor or a line pressure detected by the line pressure sensor.

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Saitama, Japan

Makito Nakasone