Eco-friendly vehicle and transmission hydraulic pressure control method for the same

Patent metadata

Field	Value
Publication number	US-11441673-B2
Application number	US-201916696444-A
Country	US
Kind code	B2
Filing date	Nov 26, 2019
Priority date	Mar 8, 2019
Publication date	Sep 13, 2022
Grant date	Sep 13, 2022

Abstract

An eco-friendly vehicle and a transmission hydraulic pressure control method for the same are provided. The vehicle includes an oil pump that estimates an inner temperature without using a temperature sensor. The method includes determining a driver request output and determining a required hydraulic pressure corresponding to the request output. A temperature of an oil pump unit is estimated to operate an electric oil pump to supply a hydraulic pressure to a transmission, based on the required hydraulic pressure and driving status information. An output torque is then adjusted based on the estimated temperature.

First claim

What is claimed is:

1. A transmission hydraulic pressure control method for an eco-friendly vehicle, comprising:
determining, by a controller, a driver request output;
determining, by the controller, a required hydraulic pressure that corresponds to the request output;
estimating, by the controller, a temperature of an oil pump unit to operate an electric oil pump to supply a hydraulic pressure to a transmission, based on the required hydraulic pressure and driving status information; and
adjusting, by the controller, an output torque based on the estimated temperature.

2. The transmission hydraulic pressure control method according to claim 1 , wherein the driving status information includes a driving time and a request torque.

3. The transmission hydraulic pressure control method according to claim 2 , wherein the estimating of the temperature of the oil pump unit is executed using a previously prepared temperature estimation expression.

4. The transmission hydraulic pressure control method according to claim 3 , wherein the temperature estimation expression is determined based on a correlation of between a driving time and a temperature according to the request torque on a required hydraulic pressure basis.

5. The transmission hydraulic pressure control method according to claim 1 , wherein the adjusting of the output torque includes determining whether the estimated temperature is less than a predetermined protective temperature.

6. The transmission hydraulic pressure control method according to claim 5 , further comprising:
determining, by the controller, the request torque to be the output torque when the estimated temperature is determined to be less than the predetermined protective temperature, based on results of the determination.

7. The transmission hydraulic pressure control method according to claim 5 , further comprising:
limiting, by the controller, the output torque to be less than a predetermined protective torque when the estimated temperature is determined to be greater than the predetermined protective temperature, based on results of the determination.

8. A non-transitory computer-readable recording medium recorded with a program to execute the transmission hydraulic pressure control method according to claim 1 .

9. An eco-friendly vehicle, comprising:
an electric oil pump configured to supply a hydraulic pressure to a transmission; and
an oil pump unit configured to acquire a driver request output, determine a required hydraulic pressure corresponding to the request output, estimate an inner temperature based on the required hydraulic pressure and driving status information, and adjust an output torque based on the estimated temperature, while operating the electric oil pump.

10. The eco-friendly vehicle according to claim 9 , wherein the driving status information includes a driving time and a request torque.

11. The eco-friendly vehicle according to claim 10 , wherein the oil pump unit is configured to estimate the inner temperature using a previously prepared temperature estimation expression.

12. The eco-friendly vehicle according to claim 11 , wherein the temperature estimation expression is determined based on a correlation of between a driving time and a temperature according to the request torque on a required hydraulic pressure basis.

13. The eco-friendly vehicle according to claim 9 , wherein the oil pump unit is configured to determine whether the estimated temperature is less than a predetermined protective temperature.

14. The eco-friendly vehicle according to claim 13 , wherein the oil pump unit is configured to instruct a hybrid controller to determine the request torque to be the output torque when the estimated temperature is less than the predetermined protective temperature.

15. The eco-friendly vehicle according to claim 13 , wherein the oil pump unit is configured to instruct a hybrid controller to limit the output torque to be less than a predetermined protective torque when the estimated temperature is greater than the predetermined protective temperature.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Kim Kyung Su
• Kim Hyeon Jun
• Kim Yong Hyun

Classifications

• B60W10/30

  including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps · CPC title

• F01M2001/0215

  Electrical pumps · CPC title

• F16H59/78

  Temperature · CPC title

• F16H61/0025 Primary

  Supply of control fluid; Pumps therefor · CPC title

• B60W50/10

  Interpretation of driver requests or demands · CPC title