Controller and control method for electric oil pump
View Patent ↗An electric oil pump (ELOP) provided in parallel to a mechanical oil pump driven by an engine supplies oil to a clutch of a transmission. The ELOP is rotated in advance of a request to operate the ELOP at a targeted relatively-low first preoperation rotational speed. When an actual rotational speed matches the first preoperation rotational speed and an actual current matches a threshold, the ELOP is rotated at a targeted relatively-high second preoperation rotational speed. At least when an actual rotational speed matches a second predetermined rotational speed not higher than the second preoperation rotational speed, it is determined that preoperation is completed. If the number of restarts during the preoperation as one operation history of the ELOP reaches or exceeds the predetermined number of times, the current supply to the ELOP is interrupted to limit the restart, thereby reducing the number of repeated restarts of the ELOP.
1. A controller for an electric oil pump which is provided in parallel to a mechanical oil pump driven by an internal combustion engine as a power source of a vehicle to supply oil to a transmission for the vehicle, and which is configured to supply oil to at least a part of the transmission, the controller comprising:
a microcomputer, wherein
the microcomputer is configured to implement a determination mode in which the electric oil pump is rotated at a second preoperation rotational speed in advance of a request to operate the electric oil pump, and at least when an actual rotational speed matches a second predetermined rotational speed not higher than the second preoperation rotational speed, it is determined that preoperation for the electric oil pump is completed,
the microcomputer is configured to implement a preoperation mode in which, under at least one condition that it is not yet determined that preoperation for the electric oil pump is completed, the electric oil pump is rotated at a first preoperation rotational speed that is lower than the second preoperation rotational speed and the second predetermined rotational speed, and also configured to shift the preoperation mode to the determination mode when the actual rotational speed matches the first preoperation rotational speed and an actual current matches a predetermined threshold, and
microcomputer is configured to limit restart of the electric oil pump when an integrated current value as an integrated value of current amounts supplied to the electric oil pump matches a value at which a temperature of a component of the electric oil pump reaches an allowable temperature.
2. The controller for the electric oil pump according to claim 1 , wherein the microcomputer is configured to ease limitation on restart of the electric oil pump when an oil temperature of the oil is increased by a predetermined temperature after the restart of the electric oil pump is limited.
3. The controller for the electric oil pump according to claim 2 , wherein the predetermined temperature is set according to a temperature of the at least the part of the transmission.
4. The controller for the electric oil pump according to claim 1 , wherein the microcomputer is configured to ease limitation on restart of the electric oil pump when a predetermined time has elapsed after the restart of the electric oil pump is limited.
5. The controller for the electric oil pump according to claim 4 , wherein the predetermined time is set according to a temperature of the at least the part of the transmission.
6. The controller for the electric oil pump according to claim 1 , wherein the microcomputer is configured to limit restart of the electric oil pump based on a current supply time corresponding to the time for supplying current to the electric oil pump.
7. The controller for the electric oil pump according to claim 1 , wherein the microcomputer is configured to limit restart of the electric oil pump based on a preoperation time required for the determination mode and the preoperation mode.
8. A controller for an electric oil pump which is provided in parallel to a mechanical oil pump driven by an internal combustion engine as a power source of a vehicle to supply oil to a transmission for the vehicle, and which is configured to supply oil to at least a part of the transmission, the controller comprising:
a microcomputer, wherein
the microcomputer is configured to implement a determination mode in which the electric oil pump is rotated at a second preoperation rotational speed in advance of a request to operate the electric oil pump, and at least when an actual rotational speed matches a second predetermined rotational speed not higher than the second preoperation rotational speed, it is determined that preoperation for the electric oil pump is completed,
the microcomputer is configured to implement a preoperation mode in which, under at least one condition that it is not yet determined that preoperation for the electric oil pump is completed, the electric oil pump is rotated at a first preoperation rotational speed that is lower than the second preoperation rotational speed and the second predetermined rotational speed, and also configured to shift the preoperation mode to the determination mode when the actual rotational speed matches the first preoperation rotational speed and an actual current matches a predetermined threshold, and
the microcomputer is configured to limit restart of the electric oil pump based on a result of comparing a number of restarts of the electric oil pump with a predetermined number of times, and the predetermined number of times is set based on a temperature of the at least the part of the transmission.
9. The controller for the electric oil pump according to claim 8 , wherein the predetermined number of times decreases when the temperature of the at least the part of the transmission increases, whereas the predetermined number of times increases when the temperature of the at least the part of the transmission decreases.
10. The controller for the electric oil pump according to claim 8 , wherein the microcomputer is configured to ease limitation on restart of the electric oil pump when an oil temperature of the oil is increased by a predetermined temperature after the restart of the electric oil pump is limited.
11. The controller for the electric oil pump according to claim 10 , wherein the predetermined temperature is set according to a temperature of the at least the part of the transmission.
12. The controller for the electric oil pump according to claim 8 , wherein the microcomputer is configured to ease limitation on restart of the electric oil pump when a predetermined time has elapsed after the restart of the electric oil pump is limited.
13. The controller for the electric oil pump according to claim 12 , wherein the predetermined time is set according to a temperature of the at least the part of the transmission.
14. A control method for an electric oil pump which is provided in parallel to a mechanical oil pump driven by an internal combustion engine as a power source of a vehicle to supply oil to a transmission for the vehicle, and which is configured to supply oil to at least a part of the transmission, the method comprising, under control of a control unit, the steps of:
implementing a determination mode in which the electric oil pump is rotated at a second preoperation rotational speed in advance of a request to operate the electric oil pump, and at least when an actual rotational speed matches a second predetermined rotational speed not higher than the second preoperation rotational speed, it is determined that preoperation for the electric oil pump is completed;
implementing a preoperation mode in which, under at least one condition that it is not yet determined that preoperation for the electric oil pump is completed, the electric oil pump is rotated at a first preoperation rotational speed that is lower than the second preoperation rotational speed and the second predetermined rotational speed, and also shifting the preoperation mode to the determination mode when the actual rotational speed matches the first preoperation rotational speed and an actual current matches a predetermined threshold; and
limiting, in the preoperation mode, restart of the electric oil pump when an integrated current value as an integrated value of current amounts supplied to the electric oil pump matches a value at which a temperature of a component of the electric oil pump reaches an allowable temperature.
15. A control method for an electric oil pump which is provided in parallel to a mechanical oil pump driven by an internal combustion engine as a power source of a vehicle to supply oil to a transmission for the vehicle, and which is configured to supply oil to at least a part of the transmission, the method comprising, under control of a control unit, the steps of:
implementing a determination mode in which the electric oil pump is rotated at a second preoperation rotational speed in advance of a request to operate the electric oil pump, and at least when an actual rotational speed matches a second predetermined rotational speed not higher than the second preoperation rotational speed, it is determined that preoperation for the electric oil pump is completed;
implementing a preoperation mode in which, under at least one condition that it is not yet determined that preoperation for the electric oil pump is completed, the electric oil pump is rotated at a first preoperation rotational speed that is lower than the second preoperation rotational speed and the second predetermined rotational speed, and also shifting the preoperation mode to the determination mode when the actual rotational speed matches the first preoperation rotational speed and an actual current matches a predetermined threshold; and
limiting, in the preoperation mode, the restart of the electric oil pump based on a result of comparing a number of restarts with a predetermined number of times, which is set based on a temperature of the at least the part of the transmission.