Under the normal temperature of paraffin in solid, the water temperature below 76 ℃, the main valve fully closed, the by-pass valve fully open, by

Cylinder head out of the water by the by-pass pipe directly into the pump, so called the minor cycle. Because only in water pump and water

Flow between water jacket, without going through the radiator, and the flow rate is small, so the cooling intensity is weak.

When the engine water temperature of 76 ℃ above, paraffin gradually became liquid volume increase, forcing rubber

Hose shrinkage, thus on the centre rod lower cone upward thrust. As a result of the rod top fixed, therefore in

Heart stem produces the reverse thrust downward to rubber hose and inductor, overcomes the spring tension to gradually open the main valve,

The opening of the by-pass valve decreases.

When the engine temperature rise to 88 ℃, the main valve fully open, by-pass valve fully closed, all of cooling water

Flowing through the radiator, known as the systemic circulation. Due to the cooling water flow lines long, large flow, cooling intensity is strong

. The role of the thermostat In the cooling system of diesel engine is equipped with thermostat, thermostat can along with the diesel engine

Water temperature and load change with the change of the strength of the cooling fluid circulation, change the cooling fluid circulation route and flow,

Keep the temperature of the diesel engine, shorten the time of the diesel engine hot start, reduce the consumption of diesel fuel, reduce

Friction pair parts wear and tear. 1. The minor cycle for without going through the radiator coolant tiny coolant cooling water cycle

Ring. Before the hot start, diesel engine cooling fluid temperature below 76 ℃, thermostat valve closed, the Lord

Valve is opened, the cooling liquid by the bypass valve into the cooling water pump inlet, and after the pump pressure cooling water flow back

Sets. Without going through the radiator coolant flow, only in the minor cycle between water jacket and water pumps.