LOW-NOISE CONSTANT FLOW VALVE AND MANUFACTURING METHOD THEREOF FOR DECREASING HIGH-FREQUENCY NOISE BY BORING MANY HOLES THROUGH A CARTRIDGE

摘要

PURPOSE: A low-noise constant flow valve and a manufacturing method thereof are provided to prevent a noise source from transmitting to ears of persons by displacing a noise frequency band from an audio frequency range and to remove quickly the noise of a week audio frequency range in the air. CONSTITUTION: In a method for manufacturing a low-noise constant flow valve(5), noise is reduced by a cartridge(20) having a great number of noise holes for rising and displacing a noise source generated at a flow control throat of the constant flow valve from an audio frequency range. The low-noise constant flow valve is composed of an inlet port(10) of fluid; an outlet port(12) for rate-controlling and discharging the fluid inserted from the inlet port; a body integrated with the inlet and outlet ports; a guide(16) formed in the body; a spring(18) installed in the guide; the cartridge elastically supported by the spring and composed of a seat unit(22) and a valve port(24) of which one side is blocked; flow-through holes(26,26a) formed around the periphery of the valve port according to the rated flow; and a plurality of fine holes bored on the flow-through holes to pass the fluid.