PURPOSE: To prevent a flow rate from increasing, the temperature of hot water from dropping, and cold water from running out of a tap even if the hydraulic pressure of water supply by increasing the fluid resistance of a flow rate sensor momentarily through the operation of a control valve.
CONSTITUTION: When the hydraulic pressure of water supply rises, a large amount of water flows in a fluid intake 9 and passes through a slit 17, so that the flow rate of water to the 1st flow passage 12 increases. Then, the differential pressure between the fluid intake 9 and flow passage 12 increases owing to the fluid resistance of the slit 17 and the control valve 16 operates against a spring 15 so as to open a valve seat 14. Consequently, the flow rate of the flow passage 12 decreases and the flow rate in the 2nd flow passage 13 increases, so the vortex in a vortex chamber 11 becomes larger. Consequently, the fluid resistance of a sensor 2 increases abruptly to prevent the flow rate of hot water from increasing momentarily. At this time, the vortex increases, so a spherical body 18 also rotates quickly to increase pulses of a detector 21 abruptly, and a control circuit 7 receiving the pulses generates a signal to control the hot water to a specific flow rate through a flow rate valve 3, so that the control valve 16 is pressed back by the spring 15 to return to its initial state.
YOKOAJIRO YOSHIYUKI
YAMAMOTO YOSHIO
