| 摘要 |
PROBLEM TO BE SOLVED: To definitely suppress overheating of a power unit comprising an engine and an automatic transmission.SOLUTION: When a temperature of a power unit P exceeds a specific value, a generated heat calculation unit M2 and a released heat calculation unit M3 calculate an amount of heat generation and an amount of heat release of the power unit P respectively. A rotation rate calculation unit M4 calculates a rotation rate of an engine at which the amount of heat generation exceeds the amount of heat release, and a change gear ratio determination unit M5 determines a change gear ratio of an automatic transmission T which can hold the rotation rate of the engine. While a change gear control unit M6 shifts the speed of the automatic transmission T to the described change gear ratio, the temperature of the power unit P holds the change gear ratio until the temperature of the power unit P becomes a specific value, and then the overheat of the power unit P is definitely suppressed and the operation force of the power unit P is ensured at a maximum. Additionally, the need of a large size radiator and an oil cooler are eliminated, thereby preventing increases in the cost, weight and size. |
