| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a hydraulic control device for an automatic transmission for preventing unintentional engagement of a friction engaging device by holding down the pumping capability of an electrically driven pump. <P>SOLUTION: Hydraulic pressure generated in the electrically driven pump H is supplied through an electric hydraulic pressure line I provided independently of a mechanical hydraulic pressure line G directly to the mechanical hydraulic pressure line G right before a pressure regulating valve F, and the back flow of hydraulic pressure supplied right before the pressure regulating valve F to a mechanically driven pump A is prevented by a back flow preventing means J. "Leak hydraulic pressure" in the electrically driven pump H is inhibited to lower the pump capability of the electrically driven pump H. Hydraulic pressure generated in the electrically driven pump H is given to the mechanical hydraulic pressure line G right before the pressure regulating valve F, and hydraulic pressure to be supplied to the friction engaging device C is controlled by the pressure regulating valve F. Thus, even when the electrically driven pump H has sudden discharge hydraulic pressure rise due to any trouble, the friction engaging device C to be in no engagement does not engage therewith to keep a vehicle safe. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
