Control device of hybrid vehicle

Abstract

A control device of a hybrid vehicle including an engine, a power transmission device, a mechanical oil pump, an electric oil pump, a first rotating machine, and a second rotating machine, the control device comprises: a hybrid control portion; and a pump control portion controlling the first rotating machine to rotate the mechanical oil pump so as to cause the mechanical oil pump to discharge the hydraulic oil when it is determined that the temperature of the hydraulic oil is lower than the predetermined oil temperature, and controlling the motor dedicated to the electric oil pump to cause the electric oil pump to discharge the hydraulic oil when it is determined that the temperature of the hydraulic oil is higher than the predetermined oil temperature, at the time of running in the motor running mode.

What is claimed is: 
     
         1 . A control device of a hybrid vehicle including an engine, a power transmission device transmitting a power of the engine to drive wheels, a mechanical oil pump rotated together with a rotation of the engine to discharge a hydraulic oil used in the power transmission device, an electric oil pump rotated by a motor dedicated to the electric oil pump to discharge the hydraulic oil, a first rotating machine configured to raise a rotation speed of the engine, and a second rotating machine coupled to the drive wheels in a power transmittable manner, the control device comprising:
 a hybrid control portion causing the hybrid vehicle to run in a motor running mode in which at least the second rotating machine is used as a drive power source for running out of the first rotating machine and the second rotating machine with operation of the engine stopped;   a state determining portion determining whether a temperature of the hydraulic oil is lower than a predetermined oil temperature; and   a pump control portion controlling the first rotating machine to rotate the mechanical oil pump so as to cause the mechanical oil pump to discharge the hydraulic oil when it is determined that the temperature of the hydraulic oil is lower than the predetermined oil temperature, and controlling the motor dedicated to the electric oil pump to cause the electric oil pump to discharge the hydraulic oil when it is determined that the temperature of the hydraulic oil is higher than the predetermined oil temperature, at the time of running in the motor running mode.   
     
     
         2 . The control device of the hybrid vehicle according to  claim 1 , wherein
 the pump control portion causes the electric oil pump to discharge the hydraulic oil in addition to causing the mechanical oil pump to discharge the hydraulic oil, when it is determined that the temperature of the hydraulic oil is lower than the predetermined oil temperature.   
     
     
         3 . The control device of the hybrid vehicle according to  claim 1 , wherein
 the hybrid control portion enables the hybrid vehicle to run in a double drive motor running using both the first rotating machine and the second rotating machine as the drive power sources in a running region in which a required drive power is achieved by a single drive motor running using only the second rotating machine as the drive power source at the time of running in the motor running mode, and wherein   the hybrid control portion prohibits the double drive motor running and performs the single drive motor running when it is determined that the temperature of the hydraulic oil is lower than the predetermined oil temperature, and permits the double drive motor running when it is determined that the temperature of the hydraulic oil is higher than the predetermined oil temperature, at the time of running in the motor running mode.   
     
     
         4 . The control device of the hybrid vehicle according to  claim 1 , wherein
 the pump control portion controls the first rotating machine such that a rotation speed of the mechanical oil pump is made higher as the temperature of the hydraulic oil is lower, when it is determined that the temperature of the hydraulic oil is lower than the predetermined oil temperature.   
     
     
         5 . The control device of the hybrid vehicle according to  claim 1 , wherein
 the pump control portion controls the first rotating machine such that a rotation speed of the mechanical oil pump is made higher as a temperature of cooling water of the engine is lower, when it is determined that the temperature of the hydraulic oil is lower than the predetermined oil temperature.   
     
     
         6 . The control device of the hybrid vehicle according to  claim 1 , wherein
 the predetermined oil temperature is a lower limit value of a predefined high oil temperature region of the hydraulic oil in which the electric oil pump discharges the hydraulic oil at a flow rate required for the power transmission device.   
     
     
         7 . The control device of the hybrid vehicle according to  claim 1 , wherein
 the power transmission device includes a differential mechanism including a first rotating element to which the engine is coupled in a power transmittable manner, a second rotating element to which the first rotating machine is coupled in a power transmittable manner, and a third rotating element to which an output rotating member is coupled, wherein   the second rotating machine is coupled to the output rotating member in a power transmittable manner, and wherein   the hybrid control portion causes the second rotating machine to output a torque responsible for a reaction torque generated in the output rotating member in association with the control of the first rotating machine, when the first rotating machine is controlled by the pump control portion and the mechanical oil pump is rotated.   
     
     
         8 . The control device of the hybrid vehicle according to  claim 7 , wherein the hybrid vehicle includes a lock mechanism for non-rotatably fixing the first rotating element. 
     
     
         9 . The control device of the hybrid vehicle according to  claim 7 , wherein
 the power transmission device includes an automatic transmission constituting a portion of a power transmission path between the output rotating member and the drive wheels and having a plurality of engagement devices with which each of a plurality of gear positions is formed by engaging a predetermined engagement device of the plurality of engagement devices, and wherein   the pump control portion causes at least one oil pump out of the mechanical oil pump and the electric oil pump to discharge the hydraulic oil at a flow rate required for engagement of the engagement device.   
     
     
         10 . The control device of the hybrid vehicle according to  claim 1 , wherein
 the power transmission device includes an engagement device having an operation state switched by the hydraulic oil, and wherein   the pump control portion causes at least one oil pump out of the mechanical oil pump and the electric oil pump to discharge the hydraulic oil at a flow rate required for engagement of the engagement device.   
     
     
         11 . The control device of the hybrid vehicle according to  claim 10 , wherein
 the power transmission device includes an automatic transmission constituting a portion of a power transmission path between the engine and the drive wheels, and wherein   the engagement device is one of a plurality of engagement devices included in the automatic transmission and selectively engaged to establish each gear position of the automatic transmission.