Abstract: An object of the invention is to provide a variable displacement compressor which is capable of using a solenoid control valve which does not require a large solenoid force. The compressor is configured such that an electromagnetic proportional flow rate control valve is arranged in a refrigerant passage leading from a discharge chamber to a condenser, that a differential pressure regulating valve is arranged in a refrigerant passage leading from the discharge chamber to a crank chamber, and that a fixed orifice is arranged in a refrigerant passage leading from the crank chamber to a suction chamber, whereby the differential pressure regulating valve senses a differential pressure Pd, Pd′ generated across the electromagnetic proportional flow rate control valve, for control of pressure introduced into the crank chamber.

Abstract: The object of the present invention is to provide a control valve for a variable displacement compressor, which is capable of controlling the variable displacement compressor to the minimum capacity without using an electromagnetic clutch, and can be constructed without accommodating a solenoid in a pressure chamber. A plunger of a solenoid is formed by a first plunger and a second plunger, and a diaphragm is disposed between them, for sensing suction pressure Ps, such that the first plunger controls a valve element via a shaft, with component elements of the solenoid except for the first plunger being disposed on a side of the diaphragm where the atmospheric pressure is received. Further, when the solenoid is not energized, the high suction pressure Ps urges the second plunger toward the core via the diaphragm, and a spring causes the first plunger to urge the valve element to the fully open position, which enables the variable displacement compressor to be controlled to the minimum capacity.

Abstract: To provide a capacity control valve for a variable displacement compressor, which is capable of returning lubricating oil contained in refrigerant into a crank chamber efficiently by a simple construction.

Abstract: To provide a low-cost block-type expansion valve containing a strainer. A block-type expansion valve is configured such that a hollow cylindrical strainer is arranged in a space for introducing high-pressure liquid refrigerant, in a manner surrounding a valve element, and the refrigerant introduced into a refrigerant pipe-connecting hole is permitted to flow into a space on the upstream side of the valve element 17 via the strainer. Therefore, since the shape of a body is not substantially changed, it is possible to provide the expansion valve at low costs by suppressing an increase in the manufacturing costs to the cost of the strainer.

Abstract: The object of the present invention is to provide a solenoid valve-equipped expansion valve simplified in construction. A common valve element in which a valve element of an expansion valve and a valve element of a stop valve are integrally formed as a unitary member is disposed such that the common valve element can be axially movably guided by a shaft having the driving force of a power element transmitted thereto. A first core of a solenoid, holding the common valve element, is urged by a spring such that the common valve element is seated on a valve seat. When the solenoid is energized, the first core holding the common valve element is attracted by a second core rigidly fixed to the shaft such that the common valve element operates with the shaft in an interlocked fashion. As a result, when the solenoid is deenergized, the common valve element can function as a stop valve, whereas when the solenoid is energized, the common valve element can function as an expansion valve.

Abstract: The object of the present invention is to provide a capacity control valve for a variable displacement compressor that controls flow rate without the need for increased solenoid power. A compact, low-cost capacity control valve is provided as an integrated structure of a first control valve and a second control valve. The first control valve, placed on a passageway of refrigerant discharged from a variable displacement compressor, functions as a variable orifice whose cross-sectional area can be set as desired by varying the power of a solenoid unit. Part of the refrigerant discharged at pressure PdH is supplied to the crank chamber, in which the pressure is Pc. The second control valve controls this refrigerant flow to the crank chamber in such a way that the differential pressure between upstream pressure PdH and downstream pressure PdL of the discharged refrigerant will be regulated at a specified level.

Abstract: The object of the present invention is to provide a proportional valve which does not open or close by itself and is free of internal leakage. A valve element is formed integrally with a piston having a cross-sectional area equal to that of a valve hole constituting a valve seat, and a diaphragm having an outer peripheral portion secured to a body by a holder is disposed in contact with a pressure-receiving end face of the piston. The diaphragm is mounted in a displaced state such that when the valve element is seated on the valve seat, the pressure receiving area of the diaphragm is at a maximum and is equal to that of the valve element. Change in the pressure receiving area of the valve element corresponding to the lift amount thereof is canceled out by change in the pressure receiving area of the diaphragm corresponding to the amount of displacement thereof, thus preventing the valve from opening or closing by itself due to the difference between the pressure receiving areas.

Abstract: The object of the present invention is to provide a differential pressure control valve capable of preventing refrigerant from leaking along the outer periphery of a piston for actuating a main valve. An annular diaphragm has an inner peripheral edge portion clamped between a main valve piston and a fixing ring secured to the main valve piston, and an outer peripheral edge portion clamped between a body and a cylindrical member secured to the body, and the cylindrical member slidably receives the main valve piston. Thus, the outer periphery of the main valve piston is completely sealed by the diaphragm and inlet pressure P1 is introduced from a refrigerant introduction chamber into a piston chamber only through an orifice, whereby characteristics of the differential pressure control valve can be stabilized.

Abstract: A refrigerating cycle is capable of performing both an operation in which the maximum cooling power is desired to be unleashed and an operation in which the most excellent performance coefficient is attained. A refrigerating cycle is configured such that a differential pressure-regulating valve forming a pressure-reducing device is arranged between a condenser and a receiver. As a result, by setting the differential pressure regulated by the differential pressure-regulating valve 3 to 0, it is possible to cause the refrigerating cycle to perform an operation in which the maximum cooling power is desired to be unleashed, whereas by setting the same to a desired value, it is possible to cause the same to perform an operation in which an excellent performance coefficient is attained.

Abstract: To provide an air conditioning system which simultaneously eliminates shortage of lubricating oil of a variable displacement compressor and degradation of cooling efficiency of the system. An air conditioning system is configured to have a variable displacement compressor under flow rate control by a proportional flow rate control solenoid valve forming a variable orifice in a discharge-side refrigerant flow passage, and a constant differential pressure valve for controlling a differential pressure (PdH−PdL) across the variable orifice, developed depending on a flow rate Qd of refrigerant, to a constant level, and an expansion valve of a normal charge type. By providing the expansion valve of the normal charge type, it is possible to always hold refrigerant at an outlet of an evaporator in a superheated state, whereby even during low load operation, high cooling efficiency can be maintained.

Abstract: The object of the present invention is to provide a constant flow rate expansion valve which is sufficiently reduced in leakage of refrigerant. A constant flow rate expansion valve includes a refrigerant passage having a fixed flow path cross-sectional area smaller than that of a refrigerant inlet, a differential pressure control valve for controlling the differential pressure (P1−P2) between an inlet pressure P1 and an intermediate pressure P2 generated by refrigerant flowing through the refrigerant passage to be constant, and a solenoid capable of setting the differential pressure by the value of an electric current externally supplied. In the differential pressure control valve, a piston and a valve element integrally formed with each other sense the differential pressure (P1−P2), change a gap between the valve element and a valve seat such that the differential pressure is held constant, and adiabatically expand the refrigerant at the gap.

Abstract: The object of the present invention is to provide an expansion valve that suppresses noise generated when an air conditioner is started, and achieves saving of driving force. The stroke of a valve element is set such that refrigerant flows at a flow rate 1.0 to 1.4 times the flow rate corresponding to the set tonnage. This limits the valve lift of the valve in the fully open state during start-up such that it provides a flow rate of refrigerant only 1.0 to 1.4 times the flow rate corresponding to the set tonnage. This prevents an unnecessary and excessive amount of refrigerant from flowing, whereby it is possible to reduce flow noise of refrigerant during start-up. Further, since the excessive amount of flow of refrigerant is reduced, it is possible to achieve saving of driving force.

Abstract: The object of the present invention is to provide a method of controlling a refrigeration cycle such that maximum refrigerating capacity can be educed when the refrigeration cycle is started, the driving torque of a variable displacement compressor can be reduced when an automotive vehicle performs standing start or acceleration, and the refrigeration cycle can be operated with the maximum efficiency in a steady operating condition.

Abstract: The object of the present invention is to provide a three-way switching valve having a valve mechanism compact in size, and capable of changing a flow of a high-pressure fluid, without internal leakage of the fluid. A compact pilot-operated three-way switching valve changes a flow of a fluid introduced into an inlet port such that the fluid is caused to flow into a first outlet port or a second outlet port. Pressures in pressure-regulating chambers above pistons are selectively guided into a passage by a pilot valve having a pilot valve element, plugs including respective valve seats, and a spring. The passage leads one of the pressures to the first outlet port or the second outlet port via a check valve having valve, and a valve element. The check valve causes a very small amount of fluid permitted to flow so as to keep main valves open and closed, respectively, to flow to the downstream side of an open one of the main valves, whereby internal leakage of fluid is prevented.

Abstract: A displacement control valve which is capable of shortening a time period for transition in operating displacement, and operating without necessitating a large solenoid force even if the size of the valve is increased so as to increase the amount of refrigerant. A differential pressure-sensing section is separated from a valve section, and caused to sense the differential pressure by a small-diameter piston rod such that even a small-sized solenoid section can set a differential pressure. A valve element, which is formed to have a larger diameter than that of the piston rod to increase the amount of refrigerant, is configured to operate as a member formed in one piece with a shaft.

Abstract: A displacement control valve that performs transition between operating capacities in a reduced time period. A valve element for introducing refrigerant from a discharge chamber into a pressure-regulating chamber after reducing discharge pressure Pd of the refrigerant to pressure Pc1, and a valve element for introducing refrigerant having pressure Pc2 from the pressure-regulating chamber into a suction chamber under suction pressure Ps are configured to open and close in an interlocked fashion, and a displacement control valve is comprised of the valve elements and a solenoid section that applies to a solenoid force corresponding to a predetermined differential pressure to these valve elements.

Abstract: The object of the present invention is to provide a capacity control valve for a variable displacement compressor, which is not adversely affected by pressure from a pressure-regulating chamber in actual operation.

Abstract: To provide an outflow prevention device which is capable of preventing refrigerant from flowing out into a vehicle compartment even when an evaporator has ruptured.

Abstract: The object of the present invention is to provide a capacity control valve for a variable displacement compressor, which is not adversely affected by pressure from a pressure-regulating chamber. A three-way valve structure is formed in which a high-pressure valve element and a low-pressure valve element are integrally formed at both ends, and valve seats with valve holes having the same diameter are arranged in a manner opposed to the respective valve elements. A discharges pressure is supplied from the upstream side of the valve seat, and a suction pressure is supplied from the downstream side of the valve seat. Pressures from a pressure-regulating chamber are received at the downstream side of the high-pressure valve element and the upstream side of the low-pressure valve element.

Abstract: An object of the invention is to provide a low-cost in-car sensor equipped with an aspirator fan motor, which is capable of detecting temperature and humidity. A thermistor for detecting temperature and a humidity sensor are arranged at desired positions on a mounting board, and the temperature and humidity of air drawn from an air inlet port and exhausted from an air outlet port are detected. At the same time, the use of electronic circuit components forming a voltage regulator circuit and a filter circuit for coping with electromagnet interference which have been employed in a brushless motor drive circuit for the aspirator fan motor is shared by the humidity sensor. This makes it possible to reduce the number of electronic circuit components necessary for the humidity sensor, and provide a low-cost in-car sensor equipped with an aspirator fan motor, enabling construction of a more inexpensive automotive air conditioner.