Improvement
Improvement of folding temperature control driving element
Shanghai University of engineering and technology has developed a new type of thermostat based on paraffin thermostat and a cylindrical coil spring copper based shape memory alloy as temperature control driving element. When the starting cylinder temperature of the thermostat is low, the bias spring compresses the alloy spring to close the main valve and open the auxiliary valve for small circulation. When the coolant temperature rises to a certain value, the memory alloy spring expands and compresses the bias spring to open the main valve of the thermostat. With the increase of coolant temperature, the opening of the main valve gradually increases, and the auxiliary valve gradually closes for large circulation.
As a temperature control unit, the memory alloy makes the valve opening action relatively gentle with the change of temperature, which is conducive to reducing the thermal stress impact on the cylinder block caused by the low-temperature cooling water in the water tank when the internal combustion engine is started, and improving the service life of the thermostat. However, the thermostat is modified from the wax thermostat, and the structural design of the temperature control driving element is limited to a certain extent.
Improvement of folding valve
The thermostat has a throttling effect on the coolant. The power loss of the internal combustion engine caused by the loss of coolant flowing through the thermostat can not be ignored. In 2001, Shuai Liyan and Guo Xinmin of Shandong Agricultural University designed the valve of the thermostat as a thin cylinder with holes on the side wall, formed a liquid flow channel from the side holes and middle holes, and selected brass or aluminum as the material of the valve, Make the valve surface smooth, so as to reduce the resistance and improve the working efficiency of the thermostat.
