Hydraulic control device for automatic transmission

A hydraulic control device for use in an automatic transmission including a fluid transmission apparatus, a lockup clutch capable of locking up the fluid transmission apparatus, and an automatic speed change mechanism changing a speed of rotation transmitted from the fluid transmission apparatus and transmitting the changed speed to driving wheels, wherein the hydraulic control device comprises:

• an oil pump that is driven in accordance with rotation of a driving source;
• a working pressure regulating portion that regulates a working pressure based on an oil pressure generated by the oil pump;
• a first lubricant supply passage for supplying a back pressure of the working pressure to a lubricant passage for lubricating the automatic speed change mechanism;
• and
• a lockup switch mechanism that turns on/off the lockup clutch by switching a supply/discharge path of the working pressure to/from the fluid transmission apparatus, the hydraulic control device comprising:
• a second lubricant supply passage, which is different from the first lubricant supply passage, for supplying the working pressure to the lubricant passage, wherein
• the second lubricant supply passage includes a first oil passage for supplying the working pressure to the lockup switch mechanism and a second oil pressure for supplying the working pressure, which is supplied to the lockup switch mechanism from the first oil passage, to the lubricant passage from the lockup switch mechanism,
• the first oil passage and the second oil passage are disconnected from each other when the lockup clutch is turned on by the lockup switch mechanism.