电子节温器工作原理（Working principle of electronic thermostat）

电子节温器工作原理（Working principle of electronic thermostat） 电子节温器工作原理(Working principle of electronic thermostat) The working principle of electronic thermostat Electronic control engine cooling system in the popular Audi APF (1.6L inline 4 cylinder engine) has been applied, the coolant temperature in the system regulation, cooling fluid circulation (temperature control), The cooling fan work is decided by the engine load and engine control unit control, The equipment compared to the traditional cooling system of engine is better at partial load of the fuel economy and lower emissions of CO / HO. Two, the cooling system layout and cooling liquid distribution unit The electronic control cooling system with minimal change to change the traditional cooling cycle, completed the re arrangement of cooling: distribution of coolant flange and the thermostat a signal synthesis unit, The engine cylinder Hugh does not need any temperature adjusting device. Three, the temperature adjusting unit (actuator, temperature regulation function is equivalent to the traditional thermostat) Four, the temperature adjusting unit in the condition of the state 1. engine cold start. When the load is small when the engine during cold start, warm up, as with the traditional cooling system, in order to make the engine to normal operating temperature as quickly as possible, for the small circulation system. In the cold start, warm and small load, cooling fluid through the cylinder head, distributor plane flows, at this time, the small circulation valve is opened, the coolant flow directly through the small valve return pump at. The formation of small cycles. In the small load after warm-up, the coolant temperature is 95 - 110 C. 2. engine full load When the engine full load operation, requiring higher cooling capacity. The control unit according to the calculated values obtained by the sensor signal conditioning unit load voltage to the temperature, dissolved wax, The circulation valve open, connected cycle. At the same time, the closure of small circulation channel, cut off the small cycle. At full load the cold to mouth liquid temperature of 85 - 95 C. Five, with the engine electronic control cooling system control unit and system principle 1. with the electronic control cooling system of the engine control unit The engine control system is the SIMOS3.3 system, the "computer" has been a characteristic diagram of the electronic control cooling system in the program, compared with the traditional engine control unit function increases, It receives sensor signals sent to the electronic control cooling system and actuator drive electronic control system, and the design of the monitoring circuit of electronic control cooling system, Therefore, the electronic control cooling system has the function of self diagnosis and included in the engine control system of self diagnosis, can By using V.A.S5051 / V.A.G5051 / V.A.G5052 self diagnosis. 2. input and output signals The input signal of the engine control unit: radiator reflux temperature; heater control potentiometer. The engine control unit output signal: temperature regulating unit load voltage; cooling fan control (two fans were used to separate output signals). The 3. basic working principle The sensor system necessary for the acquisition of information, the engine control unit to calculate the information time, and the corresponding control according to the calculation results: The activation of the heating resistance, open circulation, regulating the coolant temperature The activation of the cooling fan, rapidly reducing the coolant temperature 4. warm wind control (1) when the temperature knob switch is in the "non closed" position, that is to say, As long as the temperature control knob is not closed, the microswitch is open, two-way valve activates N147, And through the vacuum driven heat exchanger (heater) coolant shutoff valve (the repairman often said that the warm water valve), open the. (2) the use of warm air vehicles in the process of air conditioning temperature control knob on the control panel (G267) driver intention recognition (temperature), To adjust the temperature of cooling liquid. When the temperature knob is in the 70% position, the coolant temperature will reach 95 degrees celsius. The vehicle in the heating process, the driver of the vehicle identification by potentiometer heating requirements, Adjust the temperature of the cooling liquid, so that it is in the appropriate temperature range (if the temperature difference reaches 25 DEG C, is considered incorrect). 5. the two coolant temperature sensor (G62 and G83) and cooling fan control actual coolant temperature value through two different points of identification in the circulatory system, The transmission to the engine control unit and a voltage signal. The coolant temperature at the outlet of the actual value of the coolant to coolant flange 1 collection; Coolant temperature 7 coolant temperature sensor and circuit diagram of the actual position value of 2 in the radiator before the outlet collection. The characteristics of pre cooling liquid in "computer" in the value and temperature value of 1 phase comparison, Give a pulse signal to the heating resistor load voltage thermostat; 1 and 2 comparing the temperature value, adjusting the radiator fan. If the coolant temperature G62 damage, The coolant temperature control to 95 DEG C for alternative values, and a fan with 1 stalls often turn; if the coolant temperature sensor G83 damage control function, 1 stalls often turn fan; If one temperature exceeds the limit, the fan 2 stalls to be activated; if two sensors are damaged, the maximum voltage value is loaded sub heating resistance, and fan 2 stalls often turn. When the engine full load with sufficient cooling capacity, in order to improve the cooling capacity, the control unit is provided with two speed fan motor. Depending on the difference engine and radiator outlet outlet temperature to control the fan speed. The engine control unit is stored in Figure two characteristics of fan intervention or cut off, They are the decisive factor of engine speed and air flow (engine load). If a fault occurs in the output end of the first fan, second fan is activated (alternative); If a fault occurs in the output end of the second fan, the control unit will fully open the thermostat (safe mode). After the engine is switched off, due to the influence of temperature, The fan will continue to operate for a period of time; the speed of more than 100km / h, the fan doesn't work, because of higher speed, unable to provide additional cooling fan; The vehicle with traction or air conditioning, two fan motor work (big circulation). 6. temperature control unit F265 control When at the start or stop condition, no voltage loading: temperature regulation unit heating system is not heating and cooling liquid paraffin, but body heating temperature regulation unit, The open loop; heating resistance in expansion temperature adjusting unit in paraffin; according to the characteristics of heating resistance diagram of paraffin wax, paraffin expansion displacement of X, The temperature adjusting unit of mechanical adjustment through the displacement; heating by the engine control unit sends a pulse signal to complete; degree of heating is determined by the pulse width and time. (