PURPOSE: To try prevention of overheating of a heating element, by driving the opening and shutting of choke valve by bimetal to operate due to heating element, connecting the feeler element of positive-going temperature characteristics and negative-going temperature characteristics to the closed circuit which includes heating element and power source in a series.
CONSTITUTION: When the temperatures of both feeler elements 11, 12 are lower than that at the point a, with connecting the power source 10, angular position of bimetal 2, that is, the opening of choke valve 1 increases gradually along with passing of the time as shown in the curve A, both feeler elements 11, 12 reaches the temperature of point b due to the temperature rise of atmosphere with temperature rise of the internal combustion engine, the temperature rises quickly until it reaches the temperature of point c. In the case that the periphery temperature is initially in a range of a-b, when the power source 10 is connected the opening of choke valve 1 increases quickly as shown in the curve B from the beginning. At the temperature over the point C, since component resistance value of both feeler elements 11, 12 rises quickly, the current through the heating element 3 is small. Consequently overheating of the heating element 3 may be prevented
IMADA KUNIO
TOMIKAWA TAKAAKI
| JPS5273237A | 1977-06-18 |