| 摘要 |
PURPOSE:To control a thermostat to set a low temperature of cooling fluid in the range of high speed of an engine, by sensing the delivery pressure of a water pump so as to drive the thermostat in the valve opening direction, when a valve opening temperature of the thermostat is switched ''high'' under a low load while ''low'' under a high load. CONSTITUTION:The shaft 3B of a thermostat 2 supported between a water outlet 16 and an outlet housing 17 is adapted to a control piece 4 mounted on a diaphragm 6, and a valve opening temperature is switched in accordance with a load caused by the intake negative pressure introduced into a negative pressure chamber 7. Further, a diaphragm 18 is secured to the control piece 4, so that the pump delivery pressure is introduced into a water pressure chamber 19 above the diaphragm 18 through passages 21C, 21B, 21A. Accordingly, if an engine comes to be operated in the range of high speed, the pump delivery pressure increases to lower the control piece 4, causing the thermostat 2 to be driven in the valve opening direction. |
