| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide piston structure for an automatic transmission restricted not to supply the oil pressure more than necessity. <P>SOLUTION: When the oil pressure for switching shift stage is supplied, each rib 22 of a first piston member 10 is moved toward a multiple disc clutch side by pushing force of a second cam surface 30 of a second piston member 12, resisting energizing force of a return spring 16, to rotate a body 20 of the first piston member 12 in a direction expressed with an arrow 50 when a first cam surface 26 of each rib 22 slips out of a second engagement groove 42 of a piston cover 14. A first cam surface 26 of each rib 22 is thereby engaged with a first engagement groove 40 of the piston cover 14 to fix the first piston member 10 (refer to Fig.2). As a result, even if supply of the oil pressure is stopped thereafter, the multiple disc clutch is maintained in the friction engagement state. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
