| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To enable lubrication oil to bypass an oil cooler in the optimal condition while suppressing considerable change in equipment design, increase in the number of components, and enlargement of a device regarding an automatic transmission. <P>SOLUTION: The automatic transmission drives a switching valve 1 for switching supply of hydraulic oil to a hydraulic operation mechanism by electrical control in accordance with a shift range position selected by a driver. The automatic transmission is equipped with the oil cooler 5 in the middle of a supply passage for supplying the lubrication oil to lubrication-requiring portions 7, 8 inside the transmission. The switching valve 1 has a bypass position for directly supplying the hydraulic oil to the lubrication-requiring portions 7, 8 not through the oil cooler 5. When a determination portion 32a determines extremely low temperature of the oil, which means decrease in oil flow rate to the lubrication-requiring portions 7, 8, the switching valve 1 is shifted to the bypass position. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
