Fujikoki Corporation

Tokyo Electron Limited

Masakatsu Minowa

Kazuhiko Watanabe

Masamichi Yano

Kazuto Kobayashi

Two case members of the same shape are attached to the body of an expansion valve and a temperature sensing drive element through sound insulating members. Each of the two case members is formed having upper retaining and retainable portions at its upper part and lower retaining and retainable portions at its lower part. The upper retaining portion, upper retainable portion, lower retaining portion, and lower retainable portion of one of the case members are in engagement with the upper retainable portion, upper retaining portion, lower retainable portion, and lower retaining portion, respectively, of the other case member.

Expansion valve

A method for preventing hunting of a thermal expansion valve used to control the flow of refrigerant supplied to an evaporator in a refrigeration cycle. A refrigeration apparatus is provided with a compressor, a condenser, a receiver, an expansion valve, and an evaporator connected in this order, spherically activated carbon made of phenol having pore sizes fit for molecular sizes of a working fluid is prepared; and the spherically activated carbon is provided into the expansion valve; whereby hunting, or the repeated opening and closing of the expansion valve, is prevented.

Method for preventing hunting of expansion valve within refrigeration cycle

A system and method for preventing hunting of a thermal expansion valve used to control the flow of refrigerant supplied to an evaporator in a refrigeration cycle. A refrigeration apparatus is provided with a compressor, a condenser, a receiver, an expansion valve, and an evaporator connected in this order, spherically activated carbon made of phenol having pore sizes fit for molecular sizes of a working fluid is prepared; and the spherically activated carbon is provided into the expansion valve; whereby hunting, or the repeated opening and closing of the expansion valve, is prevented.

System for preventing hunting of expansion valve within refrigeration cycle

A thermal expansion valve includes an adsorbent &prime; placed inside a temperature sensing unit , wherein an activated carbon having pore sizes fit for the molecular sizes of a temperature-responsive working fluid sealed inside the temperature sensing unit is utilized as said adsorbent &prime;, so that the adsorption quantity of the adsorbent will be fixed.

Thermal expansion valve

A heat transmission retardant member is formed of a cup-like shaped resin material utilizing nylon or polyacetals, comprising a collar , and a thick-walled cylinder portion having at the lower end thereof a tapered portion . Said retardant member contacting the outer surface of a heat-sensing driven member . Said retardant member is mounted to said driven member so as to cover the outer surface thereof and being mounted outside the second refrigerant passage , said cylinder portion defining a space between the exterior of the driven member and the interior of said cylinder portion . By the existence of the activated carbon , the hunting phenomenon and the invasion of the refrigerant to a lower chamber is prevented, and the heat from the heat transmission retardant member is transmitted to the heat sensing driven member via space which enables to provide a further retardation to the response of the valve to the temperature change of the refrigant exiting the evaporator. The hunting is further suppressed effectively.

Reference &prime; refers to a heat-sensing driven member constituting a thermal expansion valve formed by a stainless steel material and the like and having in the inside thereof an adsorbent , with a collar formed to the outside of the opening of the heat-sensing driven material &prime;. A protrusion and a groove is formed to said collar in the downward direction of the drawing. Said protrusion and said groove are formed to the whole perimeter of said collar . Moreover, a diaphragm formed for example of stainless steel material is inserted to said heat-sensing driven member &prime; through an opening formed to the center area thereof until it contacts said protrusion , and said diaphragm is fixed to said heat-sensing driven member &prime;. As a result, the diaphragm is welded by said protrusion between said collar and said support member . The end of the diaphragm is sandwiched between housings and and fixed to position by welding.

A heat transmission retardant member which is a cylinder-shaped resin tube made of nylon or polyacetals is mounted between an adsorbent and an inner wall of a hollow portion of a heat-sensing driven member with a space &prime; between said inner wall. The hollow portion of said heat-sensing driven member includes said adsorbent said heat transmission retardant member made of resin, and said space &prime;. Said heat transmission retardant member comprises plural protrusions, and by positioning said protrusions to contact said inner wall, said space &prime; is formed. Since said space &prime; is formed between said inner wall of the hollow portion of said heat-sensing driven member and said heat transmission retardant member not only is the heat transmission to the granular activated carbon delayed by the heat transmission retardant member, but said space also effectively delays the transmission of the temperature variation of the refrigerant to the heat transmission retardant member. Thus, hunting of the valve is even further effectively suppressed.

A heat transmission retardant member is formed of a cup-like shaped resin material utilizing nylon or polyacetals, comprising a collar formed to the outside of the upper end thereof, and a thick-walled cylinder portion having at the lower end thereof a tapered portion . Said retardant member is positioned so that the upper end contacts a support member &prime;, said collar is supported by the inner surface of a housing , the outer surface of said cylinder portion contacts the inner surface of said housing , and the end of said tapered portion is inserted to a second hole and contacting the outer surface of a heat-sensing driven member and further positioned within a lower chamber defined by a diaphragm . Said retardant member is mounted to said driven member so as to cover the outer surface thereof and being mounted outside the second refrigerant passage , said tapered portion defining a space between the exterior of the driven member and the interior of said cylinder portion . Not only is the hunting phenomenon suppressed by the existence of the activated carbon, but the invasion of the refrigerant to the lower chamber is prevented, and the heat from the heat transmission retardant member is transmitted to the heat-sensing driven member via space which enables to provide a further retardation to the response of the valve to the temperature change of the refrigerant exiting the evaporator. The hunting is further suppressed effectively.

An expansion valve has a housing with a hole extending through its outer wall. A plug body seals the hole after a heat sensing gas, which senses the temperature of the gas-phase refrigerant passing through the expansion valve, is pressurized in the housing through the hole. The plug body, which is made from a cut metallic material, seals the hole to maintain the pressurized gas in the housing. The plug body is welded to the housing by an electrical weld. A corrosion inhibitor can be applied around the weld periphery to prevent corrosion from forming at the weld areas. The plug body has a line contact portion formed by a tapered surface, e.g., a conical portion, with a plurality of concentrically arranged a line contact portion, which has spaced projections. These projections can be formed, for instance, by cutting circumferentially around the tapered surface. The spacings between the spaced projections form a plurality of weld areas that can securely seal the plug body at the line contact portion to the housing.

Growing community of inventors

Tokyo, Japan

Masakatsu Minowa