Electric Oil Pump Device

Abstract

An electric oil pump device includes an electric oil pump driven by a motor and a microcomputer that adjusts a control parameter of feedback control related to a motor current value or a motor rotation speed based on an oil temperature estimated based on a relationship between at least one of a hydraulic pressure, the motor current value, or a torque of the electric oil pump and at least one of an oil discharge amount or the motor rotation speed of the electric oil pump.

1 . An electric oil pump device comprising:
 an electric oil pump including a motor and driven by the motor; and   a controller that estimates an oil temperature based on a relationship between at least one of a hydraulic pressure, a motor current value, or a torque of the electric oil pump and at least one of an oil discharge amount or a motor rotation speed of the electric oil pump detected during operation of the electric oil pump, and adjusts a control parameter of feedback control related to the motor current value or the motor rotation speed based on the estimated oil temperature.   
     
     
         2 . The electric oil pump device according to  claim 1 , wherein the controller determines an excessive or deficient state of at least one of the hydraulic pressure or the oil discharge amount of the electric oil pump based on the estimated oil temperature, and adjusts the control parameter of the feedback control related to the motor current value or the motor rotation speed so as to avoid the excessive or deficient state. 
     
     
         3 . The electric oil pump device according to  claim 2 , wherein
 the excessive and deficient states include the deficient state of at least one of the hydraulic pressure or the oil discharge amount of the electric oil pump in a case in which the estimated oil temperature is less than a first threshold and the excessive state of at least one of the hydraulic pressure or the oil discharge amount of the electric oil pump in a case in which the estimated oil temperature is greater than a second threshold, and   the controller adjusts the control parameter based on the estimated oil temperature so as to avoid at least one of the deficient state or the excessive state.   
     
     
         4 . The electric oil pump device according to  claim 1 , further comprising a table in which the estimated oil temperature during the operation of the electric oil pump and the control parameter are associated with each other, wherein
 the controller adjusts the control parameter based on the table.   
     
     
         5 . The electric oil pump device according to  claim 1 , wherein the controller adjusts the control parameter based on a correlation formula in which a correlation between the estimated oil temperature during the operation of the electric oil pump and the control parameter is defined. 
     
     
         6 . The electric oil pump device according to  claim 1 , wherein the controller controls the motor by PID control including proportional control, integral control, and differential control, and adjusts a proportional gain of the proportional control, an integral gain of the integral control, and a differential gain of the differential control as the control parameter. 
     
     
         7 . The electric oil pump device according to  claim 1 , wherein the controller estimates the oil temperature at a predetermined control cycle, and repeatedly adjusts the control parameter of the feedback control related to the motor current value or the motor rotation speed based on the oil temperature estimated at the predetermined control cycle. 
     
     
         8 . The electric oil pump device according to  claim 1 , wherein the controller estimates the oil temperature based on the motor current value and the motor rotation speed at least during steady operation of the electric oil pump or at a time of activating the electric oil pump, and adjusts the control parameter of the feedback control related to the motor current value or the motor rotation speed based on the estimated oil temperature.