| 摘要 |
PURPOSE:To enable reducing of a fuel cost, by a method wherein, on a comparatively flat road, a cooling water temperature control valve is left in a high-temperature control by a low-speed gear switch, and when running up a slope, the operation of the low-speed gear switch is released by a running-up-slope detector, and temperature of cooling water is caused to rise at a low-load range. CONSTITUTION:A negative pressure switch 5 is brought to OFF under a low load condition on a flat road, a suction pressure of a suction pipe 8 is guided to a water temperature control valve 10 through an electromagnetic valve 4, a control valve 12 is pulled, and thereby a working point of a thermostat 14 is raised, an opening valve temperature thereof rises, and temperature of cooling water is controlled at a high temperature zone. In which case, if a low speed gear switch 6 is set to a low speed gear, it is brought to an OFF condition. When running up a slope, a running-up-slope detecting switch 7 is turned ON, and temperature of cooling water is switched to a low temperature side. In the case of a high speed gear, the gear switch 6 is turned ON, the switch 5 is turned ON in case a suction negative pressure is below a set value, an electromagnetic valve 4 is switched, paths 4a and 4b are connected to each other to bring the inside of a negative pressure chamber 11 to the air, a control rod 12 is depressed, a working point of a shaft 13 is lowered, and the valve-opening temperature of the thermostat 14 falls. |
