Patent ID: 6352207
Filing Date: 2002-03-05
Classification: F16K,F25B

Abstract:
An expansion valve including a valve body having a high-pressure refrigerant passage for supplying a high-pressure refrigerant to an evaporator of a refrigeration system, and a low-pressure refrigerant passage for a low-pressure refrigerant discharged from said evaporator,a valve mechanism for regulating a flow rate of the high-pressure refrigerant in the high-pressure refrigerant passage, and a control mechanism having an airtight chamber filled with a temperature-sensing gas, a circular filling hole for filling the temperature-sensing gas into the airtight chamber, and a steel ball fixed by spot welding in said filling hole for sealing the filled airtight chamber, the control mechanism controlling the valve mechanism in accordance with a change in pressure in the airtight chamber caused by a change in volume of the temperature-sensing gas which is induced by a change in temperature of the low-pressure refrigerant flowing through said low-pressure refrigerant passage, wherein the spherical surface of said steel ball has a diameter d and said filling hole has an inner diameter D and wherein D/d is set to fall within a range from 0.6 to 0.85.