Abstract: The object of the present invention is to provide a three-way valve reduced in the number of component parts and man-hours for assembling the component parts. A pressure chamber of a piston for urging a first main valve in a valve-closing direction by a spring, and a pressure chamber of a piston for urging a second main valve in a valve-opening direction against the urging force of a spring are connected to a medium-pressure port B via a pilot valve and a pressure passage. When the pilot valve is open, the pressure in the pressure chambers into which high-pressure fluid is introduced from a high-pressure port A via an orifice is permitted to escape to the medium-pressure port B, whereby the piston is pushed upward by the high pressure to open the first main valve, and a plug is urged by the spring to close the second main valve.

Abstract: To reduce the degree of influence of differential pressure on a pilot valve of a constant flow rate expansion valve. The constant flow rate expansion valve comprises a restriction passage for restricting the flow rate of refrigerant introduced from a refrigerant inlet port, a main valve for controlling the flow rate of refrigerant having flowed out from the restriction passage for discharging the refrigerant to a refrigerant outlet port, a piston for actuating the main valve in the valve-opening/closing direction by the differential pressure between intermediate pressure on the inlet port side of the main valve and pressure in a pressure chamber formed on the opposite side of the main valve, and a pilot valve for sensing the differential pressure proportional to the flow rate of refrigerant flowing through the restriction passage, thereby controlling the pressure in the pressure chamber set by a solenoid.

Abstract: To enable a control valve for a variable displacement compressor, which operates by sensing a differential pressure between discharge pressure and suction pressure or between the discharge pressure and crankcase pressure, to enhance compression efficiency inside the compressor. In the control valve for a variable displacement compressor, according to the present invention, after a valve element on a high pressure side closes a valve hole, a valve element on a low pressure side opens a valve hole. Therefore, it is possible to eliminate a region in which both the valves on the high pressure side and the low pressure side are simultaneously open. This makes it possible to prevent refrigerant introduced into a crankcase from being immediately delivered, which makes it possible to obtain a sufficient compression efficient.

Abstract: To provide an expansion valve capable of enhancing manufacturing efficiency of a body and yield from material, thereby reducing manufacturing costs thereof. According to the expansion valve of the present invention, a body is formed by die casting an aluminum alloy, and hence even when the body has a complicated shape, it is possible to easily manufacture the body. Further, even a valve seat, which is difficult to form by extrusion, can be formed integrally with the body, and hence the manufacturing efficiency of the body can be enhanced. Furthermore, component parts, such as the valve seat and the like, conventionally formed by cutting, are also formed integrally with the body by die casting, and hence it is possible to enhance yield from material to reduce manufacturing costs of the expansion valve.

Abstract: To provide a control valve for a variable displacement compressor, which is capable of stably operating in a pressure control area, and causing the compressor to quickly shift to operation with the minimum displacement. The control valve for a variable displacement compressor is capable of realizing stable pressure control, since a force applied to a valve element in a valve-closing direction increases when the valve element is in a pressure control area, and is balanced with a force applied to the valve element in a valve-opening direction by the pressure of refrigerant. Further, when the valve element moves past an end point of the pressure control area, the force applied to the valve element in the valve-closing direction decreases to thereby increase the valve-opening degree of a valve portion when the valve portion is fully open.

Abstract: The object of the present invention is to provide a simple-construction four-way switching valve which is simple in construction and excellent in sealability, performs switching of the operation mode without producing unusual noise, and is reduced in the number of manufacturing steps through elimination of externally-mounted parts for pressure passages. Main valves having a poppet valve structure constitute a three way switching valve which is operated by a pilot valve, for switching the high-pressure refrigerant introduced into the port T1 to the port T2 or to the port T3, and main valves which have a poppet valve structure and are switched by the differential pressure between the ports T2 and T3 constitute a low-pressure three-way switching valve. This makes it possible to improve the sealability, prevent unusual noise from being generated during switching of the operation mode, and simplify the construction.

Abstract: The object of the present invention is to provide a switching valve capable of increasing the opening stroke of a valve operated by a differential pressure while saving space, thereby reducing pressure loss. A first valve is disposed between an inlet port and a first outlet port. A pilot valve is provided between a back pressure chamber for a movable plug that holds a valve sheet disposed in a manner opposed to a valve seat, and the first outlet port, such that the first valve is operated by a solenoid. A second valve is arranged between the inlet port and a second outlet port. A back pressure chamber for a movable plug that holds a valve sheet disposed in a manner opposed to a valve seat and the first outlet port are communicated with each other. The second valve is opened by the differential pressure generated by closing of the first valve, and when the first valve is opened, the second valve is closed by the spring since the differential pressure is reduced to zero.

Abstract: An expansion device which is capable of reducing generation of untoward noise due to vibration of a valve element and suppressing a valve element suction phenomenon which occurs when high-pressure refrigerant flows through a variable orifice formed between a valve seat and the valve element. A damper chamber is formed by a cylinder formed in a housing formed with a valve seat, a piston integrally formed with a valve element, and an adjustment screw. When the valve element undergoes a sudden change in pressure of introduced refrigerant, the volume of the damper chamber changes to accommodate sudden motion of the valve element, whereby vibration of the valve element is suppressed, to reduce generation of untoward noise. The ratio (b/a) of the valve element diameter (b) of the valve element to the port diameter (a) of a valve hole is set to a value not larger than 1.

Abstract: To provide a low-cost expansion device which is capable of changing a passage cross-sectional area of a restriction passage according to the pressure and temperature of introduced refrigerant, without provision of a high-pressure hermetically sealed space. The expansion device comprises a differential pressure valve for having the valve lift thereof controlled according to the differential pressure across the expansion device, and a temperature-sensing section for further controlling the valve lift of the differential pressure valve according to the temperature of refrigerant. The differential pressure valve includes a piston that has a larger outer diameter than that of a valve element and is integrally formed with the valve element.

Abstract: To provide a constant differential pressure valve which is compact in size and can be realized at low cost. In the constant differential pressure valve according to the present invention, a pipe forming a body thereof not only accommodates internal structures, such as a differential pressure control mechanism, a movable core, and a fixed core, but also serves as part of piping of a refrigeration cycle. Further, a solenoid section including a solenoid coil is disposed outside the pipe in a manner surrounding the same. Therefore, substantial integration of the differential pressure control mechanism into the piping of the refrigeration cycle can be achieved, which makes the entire constant differential pressure valve very simple in construction. As a result, reduction of the size of the constant differential pressure valve and resultant reduction of material costs and manufacturing costs can be achieved, which makes it possible to achieve low costs of the constant differential pressure valve.

Abstract: 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 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: To provide a control valve for a variable displacement compressor, including a first control valve that controls the flow rate of refrigerant flowing from a discharge chamber into a crankcase, and a second control valve that controls the flow rate of refrigerant flowing from the crankcase into the suction chamber, wherein suction pressure is sensed, and pressure in the crankcase is controlled such that suction pressure is held constant, which control valve is simplified in construction of the first and second control valves. A port (Ps) at suction pressure is formed on a side of a port (Pd) at discharge pressure, toward a solenoid, and ports (Pc1) and (Pc2) leading to and from a crankcase are formed on an opposite side of the port (Pd) to the aforementioned side, and a hollow cylindrical member is disposed in a manner extending over these ports.

Abstract: To provide a control valve for a variable displacement compressor, which is improved in slidability of a shaft that transmits a change in suction pressure to a valve element, and enhanced in controllability. In a control valve for a variable displacement compressor in which a plunger of a solenoid is divided into two, i.e. a first plunger and a second plunger, and a diaphragm is disposed therebetween for sensing suction pressure, the second plunger is held by a spring urging the second plunger in a direction away from the diaphragm, and is caused to be simply in contact with a shaft that transmits a change in the suction pressure sensed by the diaphragm to a valve element. With this construction, even when an attractive force is generated by a solenoid to move the second plunger, no couple of forces act on the shaft, and hence the shaft is prevented from being spoiled in slidability, which makes it possible to enhance controllability.

Abstract: The object of the present invention is to provide a switching valve capable of increasing the opening stroke of a valve operated by a differential pressure while saving space, thereby reducing pressure loss. A first valve is disposed between an inlet port and a first outlet port. A pilot valve is provided between a back pressure chamber for a movable plug that holds a valve sheet disposed in a manner opposed to a valve seat, and the first outlet port, such that the first valve is operated by a solenoid. A second valve is arranged between the inlet port and a second outlet port. A back pressure chamber for a movable plug that holds a valve sheet disposed in a manner opposed to a valve seat and the first outlet port are communicated with each other. The second valve is opened by the differential pressure generated by closing of the first valve, and when the first valve is opened, the second valve is closed by the spring since the differential pressure is reduced to zero.

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 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: A small sized and structurally simple capacity controller having a wide control range of a compressor with variable capacity adds a differential pressure to an inhalation pressure on an arbitrary level by a piston valve body actuated by a solenoid and by the inhalation pressure. The differential pressure is transmitted into a capacity variation mechanism of the compressor in order to change the capacity of the compressor.

Abstract: To provide a control valve for use in a variable displacement compressor, for fixed flow rate control, which can be constructed compact in size without necessitating pressure sensors for detecting a differential pressure. The control valve comprises a first valve having configuration of a check valve that opens and closes by the differential pressure between discharge pressure from a discharge chamber and discharge pressure at an outlet port of the compressor, a second valve that opens and closes by sensing the differential pressure between the discharge pressure Pdh and pressure in the crankcase, and a solenoid that sets the differential pressure across the first valve. The motion of a valve element of the first valve is transmitted to a valve element of the second valve via a shaft.

Abstract: To provide a control valve for a variable displacement compressor, which is capable of promptly restoring a high-sensitivity variable displacement compressor to a predetermined discharge capacity without causing hunting even when the rotational speed of the compressor is rapidly changed. A valve section controls the flow rate of refrigerant flowing from a discharge chamber to a crankcase, based on the differential pressure between discharge pressure and suction pressure.