A refrigeration apparatus includes: a usage-side expansion valve whose opening degree is changed in response to a change in a flow rate or a pressure of a refrigerant on the upstream side; a first expansion valve; and a controller. The controller exerts, in an oil recovery operation, an oil recovery first control on the first expansion valve to attain a first opening degree (an opening degree of increasing an opening degree of the usage-side expansion valve in relation to a reduction in the flow rate or the pressure of the refrigerant passing through the first expansion valve), to reduce the flow rate or the pressure of the refrigerant passing through the first expansion valve. The controller exerts an oil recovery second control following the oil recovery first control on the first expansion valve to attain a second opening degree (an opening degree that allows a liquid refrigerant to flow into a usage-side heat exchanger before the opening degree of the usage-side expansion valve is reduced in relation to an increase in the flow rate or the pressure of the refrigerant passing through the first expansion valve), to increase the flow rate or the pressure of the refrigerant passing through the first expansion valve.

An expansion valve is provided with a valve body including an inlet hole through which a refrigerant flows into a valve chamber, and a valve hole through which the refrigerant flows out from the valve chamber; a valve element configured to adjust an amount of the refrigerant flowing through the valve hole; a power element that is mounted to the valve body and configured to drive the valve element through a valve rod; a support member configured to support the valve element; a coil spring configured to press the valve element in a valve-closing direction through the support member; and a vibration isolation spring configured to prevent vibration of the valve element, wherein the vibration isolation spring is provided with an annular base portion disposed between the support member and the coil spring, and a plurality of leg portions that extend radially from the base portion.

An expansion valve is provided with a valve body including an inlet hole through which a refrigerant flows into a valve chamber, and a valve hole through which the refrigerant flows out of the valve chamber; a valve element configured to adjust an amount of the refrigerant flowing through the valve hole; a power element that is mounted to the valve body and configured to drive the valve element via a valve rod; a first vibration isolation spring provided in the valve chamber and configured to prevent vibration of the valve element; and a second vibration isolation spring that is in contact with the valve rod and configured to prevent vibration of the valve element.

A refrigerating system according to the invention includes a refrigerant circuit having at least one compressor, a condenser/gascooler, an intermediate pressure container, at least one evaporator and a respective expansion device before said at least one evaporator, and refrigerant pipes connecting said elements and circulating a refrigerant therethrough; a high pressure regulating device between the condenser/gascooler and the intermediate pressure container, expanding the refrigerant from a high pressure level to an intermediate pressure level; an intermediate pressure sensor sensing the intermediate pressure level; and a control unit controlling the high pressure regulating device. The control unit in operation limits the maximum refrigerant flow through the high pressure regulating device to a maximum flow value F.sub.Max, if the sensed intermediate pressure level exceeds a predetermined threshold value P.sub.IntTh.

A throttling device is equipped with a valve seat in which a valve port for connecting a primary chamber and a secondary chamber is formed, a needle valve, a needle section which is inserted into the valve port, a guide section for guiding a slide shaft of the needle valve, and a coil spring for biasing the needle valve in a valve-closing direction. The guide section and the coil spring are positioned on the primary chamber side. The position of the needle valve in the valve-closing direction is restricted by a stopper section in a manner such that the minimum gap between the needle valve and the valve port is maintained. Furthermore, the needle valve is not seated on the valve seat.

A vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.

An air conditioner includes a compressor, a condenser, an expansion valve, an evaporator, and a temperature detection unit. The temperature detection unit is attached to the condenser and is configured to detect a temperature of the refrigerant in the condenser. The expansion valve is configured to be capable of adjusting a flow rate per unit time of the refrigerant flowing through the expansion valve by adjusting a degree of opening of the expansion valve. The degree of opening of the expansion valve is increased when the temperature of the refrigerant detected by the temperature detection unit rises, and the degree of opening of the expansion valve is decreased when the temperature of the refrigerant detected by the temperature detection unit falls.

An air conditioner and a method for controlling the same are disclosed. The air conditioner implements a multistage expansion scheme by implementing serial connection between electronic expansion valves including in the R410A refrigerant-based air conditioner, and thus guarantees an optimum compression ratio in all cooling/heating load regions. Therefore, although cycle characteristics are changed by changing R410A refrigerant to R32 refrigerant, the air conditioner optimizes the cycle simply by controlling a degree of opening of electronic expansion valves, respectively. As described above, since the cycle optimization is implemented using the multistage expansion scheme in which legacy electronic expansion valves are coupled in series, the design modification is minimized without design modification of requisite constituent elements such as a heat exchanger, system implementation is facilitated, resulting in high efficiency in cost and productivity. Cooling/heating performance improvement and reliability guarantee are achieved under all load conditions, resulting in increased system efficiency.

A throttling device is equipped with a valve seat in which a valve port for connecting a primary chamber and a secondary chamber is formed, a needle valve, a needle section which is inserted into the valve port, a guide section for guiding a slide shaft of the needle valve, and a coil spring for biasing the needle valve in a valve-closing direction. The guide section and the coil spring are positioned on the primary chamber side. The position of the needle valve in the valve-closing direction is restricted by a stopper section in a manner such that the minimum gap between the needle valve and the valve port is maintained. Furthermore, the needle valve is not seated on the valve seat.

A vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.