摘要:
A vacuum chamber-forming method for forming a vacuum chamber in a power element of a control valve for a variable capacity compressor through a reduced number of steps. A power element is assembled in the atmospheric air by arranging a disk, a diaphragm, a disk, a spring and an upper housing on a lower housing, caulking the periphery of the lower housing to the periphery of the upper housing, and then soldering the junction of the upper and lower housings. The assembled power element is placed in a vacuum container, and a small hole formed in the upper housing is subjected to spot welding in the vacuum atmosphere, whereby the small hole is sealed by a weld metal.
摘要:
A control valve includes a body having a crankcase communicating port, a discharge chamber communicating port and a suction chamber communicating port, which are arranged in this order from one end side of the body, a solenoid, provided at the other end side of the body, for driving a main valve in accordance with the amount of current supplied, a power element, provided in an inner space surrounded by the body and the solenoid, capable of exerting the drive force to resist the solenoidal force created by a displacement of a pressure-sensing member of the power element, and a shaft by which the drive force of the power element is adjustable by adjusting the fixed position of one end side of the shaft, the shaft being fixed to one end of the body and the other end of the shaft being joined with the power element.
摘要:
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. In parallel with the main valve are arranged the pilot valve, the pressure chamber, and a fixed orifice in series in the direction of flow of refrigerant. This makes it possible to apply only the same level of differential pressure as that of small differential pressure applied to opposite end faces of the piston to the pilot valve, thereby making it possible to lessen the degree of influence of differential pressure on the pilot valve.
摘要:
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. Therefore, when a solenoid is not energized, it is possible to ensure a sufficient flow rate of refrigerant, thereby making it possible to cause the compressor to quickly shift to operation with the minimum displacement.
摘要:
The object of the present invention is to provide a method of operating a refrigeration cycle which is capable of preventing oil from staying in an evaporator and ensures high coefficient of performance as well as sufficient circulation of oil. An electronic expansion valve is controlled such that during normal operation, refrigerant is always in a superheated state at the outlet of an evaporator, and the refrigerant is periodically forced to have negative superheat for a predetermined time by a superheat control device. Thus, during normal operation, the refrigerant sucked into a variable displacement compressor always has superheat, whereby the refrigeration cycle can operate with high coefficient of performance and an engine driving the variable displacement compressor can be operated at high fuel efficiency. Also, the refrigerant is temporarily controlled so as to have negative superheat. Accordingly, lubricating oil stayed in the evaporator can be made to flow out to the variable displacement compressor, thus making it possible to prevent the compressor from seizing due to shortage of the lubricating oil.
摘要:
A differential pressure valve simplified in construction includes a piston integrally formed with a main valve element and arranged on the upstream side of a main valve to define a chamber for introducing refrigerant from an inlet port. The piston has an orifice and a refrigerant passage for communicating with a chamber on a back surface side of the piston. The chamber is configured such that it can be connected, via a refrigerant passage and a pilot valve element, to a chamber on the downstream side of the main valve, which communicates with an outlet port.
摘要:
To provide a control valve for a variable displacement compressor, which can be realized with a simple construction, while being equipped with the function of a check valve to be disposed at an outlet port of the compressor. The control valve for a variable displacement compressor includes a main valve that sets a cross-sectional area-fixed passage in which the passage cross-sectional area thereof is substantially constant when refrigerant flows between a discharge chamber and an outlet port of the compressor, and closes the cross-sectional area-fixed passage due to inversion of the magnitudes of pressure across the cross-sectional area-fixed passage when the compressor is not in operation, a pilot valve that controls the flow rate of refrigerant flowing from the discharge chamber to a crankcase in a manner interlocked with the differential pressure across the cross-sectional area-fixed passage received by the main valve, and a solenoid that is capable of setting a valve lift of the pilot valve by an external signal. The pilot valve controls the flow rate of refrigerant allowed to flow into the crankcase so as to make constant the differential pressure across the cross-sectional area-fixed passage, to thereby provide control such that the flow rate of refrigerant allowed to flow to the outlet port of the compressor is constant.
摘要:
To provide a small-sized solenoid-driven flow-regulating expansion valve which can be realized at low cost. In a flow-regulating expansion valve according to the present invention, a pipe forming a body thereof not only accommodates internal structures, such as a flow-regulating mechanism, a movable core, and a fixed core, but also serves as a 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 flow-regulating mechanism in the piping of the refrigeration cycle can be achieved, which makes the entire flow-regulating expansion valve very simple in construction. As a result, reduction of the size of the flow-regulating expansion valve and resultant reduction of material costs and manufacturing costs can be achieved, which makes it possible to achieve low costs of the flow-regulating expansion valve.
摘要:
To provide an expansion device that is configured compact in size and capable of effectively preventing an abnormal rise in pressure within the expansion device caused by the differential pressure across the expansion device. An expansion device according to the present invention cancels part of refrigerant pressure by a pressure-canceling structure. More specifically, by the amount of pressure received by a valve-closing pressure-receiving surface, the elastic force required of a spring can be reduced. As a result, a small-sized spring can be employed as the spring, and the entire expansion device can be made compact in construction. Further, when the differential pressure across the expansion device has become equal to or higher than a predetermined value, a relief mechanism enables refrigerant flowing in from the upstream side to escape into a passage other than a refrigerant passage through a valve element. This makes is possible to prevent an abnormal rise in the refrigerant pressure inside the expansion device, thereby preventing breakage or the like of the internal components.
摘要:
A four-way switching valve free from leakage of a refrigerant is disclosed. The valve includes two three-way switching valves arranged side by side, each having a pressure-regulating chamber, a piston, and a plug coaxially arranged. One of the pressure-regulating chambers selectively communicates with a low-pressure chamber or a high-pressure chamber via a three-way solenoid valve. The other pressure-regulating chamber communicates with another chamber in which the pressure increases or decreases as the pressure within one of the pressure-regulating chambers decreases or increases. As a result, refrigerant leakage is prevented, in turn preventing degradation of the refrigerating power of a system.