Engine with variable flow rate oil pump

An engine with a variable flow rate oil pump including a main pump section and a subsidiary pump section having mutually different discharge rates, and an oil pressure-adjusting valve that adjusts supply oil pressure from the main pump section and the subsidiary pump section to oil pressure supply destinations, the engine comprising:

• a main discharge passage that extends from the main pump section;
• a subsidiary discharge passage that extends from the subsidiary pump section and joins the main discharge passage via the oil pressure-adjusting valve;
• a subsidiary relief passage that extends from the oil pressure-adjusting valve to the suction side of the subsidiary pump section;
• a main relief passage that extends from the oil pressure-adjusting valve to the suction side of the main pump section separately from the subsidiary relief passage;
• and
• a check valve that is provided on the downstream side of the oil pressure-adjusting valve in the subsidiary discharge passage and cuts off the flow of oil from the main discharge passage side to the oil pressure-adjusting valve side,
• wherein the oil pressure-adjusting valve has a main pressure-adjusting chamber for adjusting the discharge rate of the main pump section, a subsidiary pressure-adjusting chamber for adjusting the discharge rate of the subsidiary pump section, and a valve body that performs partitioning between the main pressure-adjusting chamber and the subsidiary pressure-adjusting chamber in an oil-tight manner.