Hydraulic control device

A hydraulic control device comprising:

• a pump for discharging oil;
• a first predetermined portion configured to receive the oil discharged from the pump;
• a first channel establishing a communication between the pump and the first predetermined portion;
• a second channel branched from the first channel for supplying oil to a second predetermined portion arranged separately from the first predetermined portion;
• a flow passage area regulation unit arranged on the second channel, the flow passage area regulation unit equipped with a spool moving in a direction for increasing a flow passage area when an oil pressure in the second channel increases and moving in a direction for decreasing a flow passage area when the oil pressure in the second channel decreases, the spool possessing an outer peripheral surface, the flow passage area regulation unit including a biasing member retained in a space formed in the spool, the biasing member biasing the spool in a direction to reduce a dimension of the flow passage area of the second channel for lubricating oil;
• and
• a bypass channel provided separately from a portion of the second channel where the spool disconnects the second channel, the bypass channel establishing a communication between an upstream side and a downstream side of the second channel relative to the flow passage area regulation unit, the bypass channel supplying oil to the second predetermined portion even in a closed state in which the spool disconnects the second channel, the bypass channel being an annular groove on the outer peripheral surface of the spool so that oil flows on the outer peripheral surface of the spool along the annular groove.