| 摘要 |
A hydraulic control device for an automatic transmission is provided. The hydraulic control device can sets up any gear from a plurality of gears by causing any one of a plurality of frictional engagement elements to selectively carry out an engagement operation. The hydraulic control device includes: a regulator valve that regulates base oil pressure of hydraulic oil supplied from an oil pressure source; a relief valve provided in a lubricating oil passage connected from the regulator valve; and a line pressure switching section that sets up line pressure to low pressure to reduce the amount of lubricating oil in a region in which engagement hydraulic oil pressure does not require high engagement hydraulic oil pressure depending upon an operation state of a vehicle, and sets up the line pressure to high pressure when a target value of the engagement hydraulic oil pressure exceeds predetermined pressure.
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