Abstract: In a vehicle air conditioner, a controller is configured (i) to set a target cooling temperature of air cooled by a cooling heat exchanger, (ii) to control an operation of a compressor based on a cooling temperature and the target cooling temperature of the cooling heat exchanger, and (iii) to determine a traveling state of the vehicle. The controller is configured to set a normal target temperature as the target cooling temperature when the vehicle is traveling with a normal condition, and to set a modified target temperature higher than the normal target temperature as the target cooling temperature when the vehicle starts decelerating. In addition, the controller is configured to cause the compressor to stop operating when the vehicle starts decelerating, and to cause the compressor to restart operating when the cooling temperature detected by a temperature sensor is equal to or higher than the modified target temperature.

Abstract: A temperature sensitive rod is communicated with a diaphragm that is displaceable in response to a pressure difference between an internal pressure of a sealed space, in which a temperature sensitive medium is sealed, and a pressure of a low pressure refrigerant outputted from an evaporator. A blind hole, which opens to the sealed space, is formed in an inside of the temperature sensitive rod. The temperature sensitive medium is a mixture gas of the refrigerant and an inert gas. A mixing ratio of the inert gas in the temperature sensitive medium corresponds to a ratio of an equivalent diameter of the blind hole relative to a depth of the blind hole in such a manner that a time constant of heat conduction from the temperature sensitive rod to the temperature sensitive medium is kept within a desired time constant range.

Abstract: A temperature sensitive rod is communicated with a diaphragm that is displaceable in response to a pressure difference between an internal pressure of a sealed space, in which a temperature sensitive medium is sealed, and a pressure of a low pressure refrigerant outputted from an evaporator. A blind hole, which opens to the sealed space, is formed in an inside of the temperature sensitive rod. The temperature sensitive medium is a mixture gas of the refrigerant and an inert gas. A mixing ratio of the inert gas in the temperature sensitive medium corresponds to a ratio of an equivalent diameter of the blind hole relative to a depth of the blind hole in such a manner that a time constant of heat conduction from the temperature sensitive rod to the temperature sensitive medium is kept within a desired time constant range.

Abstract: A gas-liquid separator (accumulator) is arranged at a refrigerant suction side of a compressor of a refrigerant cycle system mounted in a vehicle. The gas-liquid separator includes a gas-liquid separation portion for separating refrigerant into gas refrigerant and liquid refrigerant, and a liquid refrigerant storage portion for storing therein the separated liquid refrigerant. In the gas-liquid separator, the gas-liquid separation portion is arranged approximately vertically, and the liquid refrigerant storage portion is arranged approximately horizontally with respect to the approximately vertically arranged gas-liquid separation portion. Therefore, mounting performance of the gas-liquid separator in the vehicle can be effectively improved while gas-liquid separation can be accurately performed.

Abstract: A refrigeration cycle device for a vehicle includes a condition detecting unit for detecting a condition that an inner pressure of the refrigerant cycle exceeds a control set pressure, and a pressure reducing unit for reducing a pressure of the refrigerant at a low pressure side of a refrigerant cycle when the condition is detected. For example, when the condition detecting unit detects the condition, the pressure reducing unit starts up a compressor of the refrigerant cycle so as to reduce the pressure at the low pressure side in the refrigerant cycle.

Abstract: The internal heat exchanger 15 for exchanging heat between the refrigerant, which has passed through the gas cooler 11 for cooling the refrigerant, and the refrigerant, which is before the suction into the compressor 10, are arranged in a space on the rear side of the fan shroud 32 with respect to the vehicle and on the outer circumferential side of the blower 31. As a space which has not been conventionally put into effective use is utilized, it is unnecessary to ensure a new space for arranging the internal heat exchanger 15 in the engine compartment.

Abstract: In an ejector cycle with an ejector including a nozzle for decompressing refrigerant, a variable throttle is disposed upstream from the nozzle of the ejector to decompress and expand high-pressure refrigerant flowing from a radiator. For example, the variable throttle decompresses and expands the high-pressure refrigerant in a gas-liquid two-phase state at an upstream position from the nozzle of the ejector. The variable throttle controls a throttle opening degree so that a refrigerant super-heating degree at a refrigerant outlet side of an evaporator or at a refrigerant suction side of a compressor becomes in a predetermined range. Accordingly, the ejector cycle has an improved nozzle efficiency and an improved ejector efficiency in a wide load variation range of the ejector cycle.

Abstract: A gas-liquid separator (accumulator) is arranged at a refrigerant suction side of a compressor of a refrigerant cycle system mounted in a vehicle. The gas-liquid separator includes a gas-liquid separation portion for separating refrigerant into gas refrigerant and liquid refrigerant, and a liquid refrigerant storage portion for storing therein the separated liquid refrigerant. In the gas-liquid separator, the gas-liquid separation portion is arranged approximately vertically, and the liquid refrigerant storage portion is arranged approximately horizontally with respect to the approximately vertically arranged gas-liquid separation portion. Therefore, mounting performance of the gas-liquid separator in the vehicle can be effectively improved while gas-liquid separation can be accurately performed.

Abstract: In an ejector cycle with an ejector including a nozzle for decompressing refrigerant, a variable throttle is disposed upstream from the nozzle of the ejector to decompress and expand high-pressure refrigerant flowing from a radiator. For example, the variable throttle decompresses and expands the high-pressure refrigerant in a gas-liquid two-phase state at an upstream position from the nozzle of the ejector. The variable throttle controls a throttle opening degree so that a refrigerant super-heating degree at a refrigerant outlet side of an evaporator or at a refrigerant suction side of a compressor becomes in a predetermined range. Accordingly, the ejector cycle has an improved nozzle efficiency and an improved ejector efficiency in a wide load variation range of the ejector cycle.