Instrument introduction
The thermostat automatically adjusts the amount of water entering the radiator according to the cooling water temperature, and changes the water circulation range, so as to adjust the heat dissipation capacity of the cooling system and ensure that the engine works within the appropriate temperature range. The thermostat must be kept in good technical condition, otherwise it will seriously affect the normal operation of the engine. If the main valve of thermostat is opened too late, the engine will overheat; If the main valve is opened too early, the engine preheating time will be prolonged and the engine temperature will be too low.
In a word, the function of the thermostat is to prevent the engine from overcooling. For example, after the engine works normally, if there is no thermostat when driving in winter, the engine temperature may be too low. At this time, the engine needs to temporarily stop the water circulation to ensure that the engine temperature is not too low.
How this section works
The main thermostat used is wax thermostat. When the cooling temperature is lower than the specified value, the refined paraffin in the thermostat sensing body is solid. The thermostat valve closes the channel between the engine and the radiator under the action of the spring, and the coolant returns to the engine through the water pump for small circulation in the engine. When the coolant temperature reaches the specified value, the paraffin begins to melt and gradually becomes liquid, the volume increases and compresses the rubber tube to make it shrink. When the rubber pipe shrinks, it acts an upward thrust on the push rod, and the push rod has a downward reverse thrust on the valve to open the valve. At this time, the coolant flows back to the engine through the radiator and thermostat valve and then through the water pump for large circulation. Most of the thermostats are arranged in the outlet pipe of the cylinder head, which has the advantages of simple structure and easy to eliminate bubbles in the cooling system; The disadvantage is that the thermostat is often opened and closed during operation, resulting in oscillation.
