Fujikoki Corporation

Fujikori Corporation

Mitsuya Fujimoto

Kazuhiko Watanabe

Masamichi Yano

An expansion valve includes a valve body, a valve, a power element, and an aluminum heat sensing shaft. The heat sensing shaft has a hole that makes the heat transfer area of the heat sensing shaft small. Consequently, in a refrigeration system the response of the expansion valve is relatively insensitive to changes in a heat load of an evaporator. Thus, unwanted hunting phenomenon in the refrigeration system is prevented.

Expansion valve

The expansion valve of the present invention comprises of a heat sensing shaft,equipped to the expansion valve,and a diaphragm,contacting its surface, a large stopper portion,for receiving the diaphragm,a large radius portion,movably inserted to the lower pressure activate chamber,and contacting the back surface of the stopper portion,at one end surface and the center of the other end surface formed at the projection,and a rod portion,whose one end surface fit to the projection,of the large radius portion,and the other end surface continuing from the valve means,wherein a concave,is formed on the outer peripheral of said projection,This concave,is the fitting means for fitting the resin,having low heat transmission rate to the heat sensing shaft in order to prevent the occurrence of hunting phenomenon.

An expansion valve includes a valve body, a valve, a power element, and an aluminum heat sensing shaft. The heat sensing shaft has a hole with a bottom reaching a heat sensing portion thereof. The hole makes the heat transfer area of the heat sensing shaft small. Consequently, in a refrigeration system the response of the expansion valve is relatively insensitive to changes in a heat load of an evaporator. Thus, unwanted hunting phenomenon in the refrigeration system is prevented.

A valve body of a thermal type expansion valve comprises of a fist path 32 and a second path 34 as the valve body 30, and a rod member 316 forming a heat sensing shaft 36f is a shaft having a small diameter, and according to the displacement of the diaphragm 361 of the power element member 36, the shaft is driven back and forth crossing the path 34. The rod member 316 has an overall length whose ratio is 17 to 28 against the outer diameter size, and is formed not to buckle against the stress added in the axial direction, which contributes to the miniaturization and lighter weight of the valve as a whole.

Thermal expansion valve

The expansion valve of the present invention comprises of a heat sensing shaft 36f equipped to the expansion valve 10 and a diaphragm 36a contacting its surface, a large stopper portion 312 for receiving the diaphragm 36a, a large radius portion 314 movably inserted to the lower pressure activate chamber 36c and contacting the back surface of the stopper portion 312 at one end surface and the center of the other end surface formed at the projection 315, and a rod portion 316 whose one end surface fit to the projection 315 of the large radius portion 314 and the other end surface continuing from the valve means 32b, wherein a concave 317 is formed on the outer peripheral of said projection 315. This concave 317 is the fitting means for fitting the resin 101 having low heat transmission rate to the heat sensing shaft in order to prevent the occurrence of hunting phenomenon.

An expansion valve comprises an orifice 30 formed in a valve body 10 and a valve member 9 fixed to a movable member 18. Movement of a diaphragm 4 is transmitted to an actuating rod 17 via a member 16, and the actuating rod 17 actuates the movable member 18 to control the opening rate of the path between the valve member 9 and the orifice 30. A seat nut member 100 affixed to the orifice 30 has a large-diameter hole 108 and a small-diameter hole 110 directly communicating with each other. Hot pressurized refrigerant introduced into the large-diameter hole 108 heats a seat portion at the exit of the large-diameter hole, and prevents moisture in the refrigerant from freezing there.

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Tokyo, Japan

Mitsuya Fujimoto