Hydraulic control apparatus and hydraulic control method

A hydraulic control apparatus comprising:

• an electromagnetic valve that has
• a solenoid including a coil,
• a cylindrical valve body connected to the solenoid,
• an input port which is provided in an open manner on the valve body and communicates with a supply destination unit of oil,
• a spool which is installed in a cylindrical portion of the valve body with a valve spring setting a threshold value for communication and is operated by a resultant force of a hydraulic pressure of the input port and an electromagnetic force of the coil exceeding the threshold value for communication, and
• a control port which is installed side by side with the input port in the valve body and in which a communication and a disconnection to the input port are switched by the spool;
• a variable displacement pump which includes
• a housing that has a suction port communicating with a supply source of the oil and an ejection port communicating with the supply destination unit,
• a control chamber that is formed in the housing and communicates with the suction port, the ejection port, and the control port,
• a cam ring that is accommodated in the housing, sections the control chamber and the suction port, sections the control chamber and the ejection port, and is able to move in a direction in which the control chamber expands or contracts,
• a rotor configured to rotate about an axial line perpendicularly intersecting a direction, in which the cam ring is able to move, inside of the cam ring, and
• a plurality of vanes that are supported by the rotor to advance or retreat in a radial direction perpendicularly intersecting the axial line with a movement of the cam ring and that have outer end surfaces in the radial direction sliding an inner circumferential surface of the cam ring,
• wherein an outer circumferential surface of the cam ring has
• a pressure receiving surface on which an ejection pressure of oil ejected from the ejection port acts, and
• a pressing surface that faces the pressure receiving surface and is pressed against an opening surface of the suction port in an inner surface of the housing in response to the ejection pressure,
• the rotor rotates in accordance with a rotation drive of the supply destination unit, and
• the variable displacement pump changes an amount of the oil ejected to the supply destination unit through the ejection port in accordance with a pressure in the control chamber by the control chamber expanding or contracting;
• and
• a control unit that is electrically connected to the coil and controls a value of a necessary current applying to the electromagnetic valve required for generating the electromagnetic force,
• wherein the control unit has
• a state decision unit configured to determine a parameter indicating a load state of the supply destination unit;
• a target hydraulic pressure calculation unit configured to calculate a target hydraulic pressure value of the supply destination unit based on a target hydraulic pressure map indicating a correlation between the determined parameter indicating the load state and the target hydraulic pressure value, and
• a necessary current calculation unit configured to calculate the value of the necessary current based on a necessary current map indicating a correlation between the target hydraulic pressure value and the value of the necessary current.