Hydraulic control unit of vehicle drive system

A hydraulic control unit of a drive system of a vehicle including an automatic transmission having a plurality of hydraulic actuators, and an oil pump device configured to pressurize a working fluid for controlling the hydraulic actuators, comprising:

• a first electromagnetic valve for generating a first hydraulic pressure to operate a first hydraulic actuator of the plurality of hydraulic actuators;
• a second electromagnetic valve for generating a second hydraulic pressure to operate a second hydraulic actuator of the plurality of hydraulic actuators;
• a first oil passage connected to the first electromagnetic valve so that a source pressure for the first hydraulic pressure is applied to the first electromagnetic valve;
• a second oil passage connected to the second electromagnetic valve so that a source pressure for the second hydraulic pressure is applied to the second electromagnetic valve;
• a third oil passage connected to the oil pump device and the second oil passage such that a pressure of the working fluid delivered from the oil pump device and flowing through the third oil passage is regulated to a predetermined value;
• a manual valve which is operated to connect and disconnect the first oil passage, the third oil passage and a drain oil passage to and from each other, in response to an operation of a manually operated shifting device by an operator of the vehicle, such that the first oil passage is connected to the third oil passage when the shifting device is placed in a first operating position, while the first oil passage is connected to the drain oil passage when the shifting device is placed in a second operating position;
• an accumulator connected to the first oil passage;
• and
• a check valve provided in the second oil passage, to prevent a flow of the working fluid in a direction from the second electromagnetic valve toward the third oil passage.