JP3963676B2 - Supercooled degree expansion valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a supercooling degree control type expansion valve used during a refrigeration cycle of a vehicle air conditioner, and in particular, refrigeration of a vehicle air conditioner having a so-called dual air conditioner structure that air-conditions a front seat side space and a rear seat side space. The present invention relates to a supercooling degree control type expansion valve suitable for application to a cycle.
[0002]
[Prior art]
In the refrigeration cycle of an air conditioner for vehicles, the refrigerant flow rate is controlled according to fluctuations in the degree of supercooling and dryness of the accumulator that separates gas and liquid by storing excess refrigerant on the outlet side of the evaporator and the high-pressure refrigerant that is discharged from the condenser. There is known a refrigeration cycle using a throttle channel (orifice) to be controlled and a supercooling degree control type expansion valve comprising a differential pressure valve for controlling the refrigerant to have a predetermined degree of supercooling.
[0003]
A configuration example of a refrigeration cycle having a dual air conditioner configuration in which the front seat side space and the rear seat side space of the vehicle are specially air-conditioned using such a type of refrigeration cycle will be described below.
[0004]
FIG. 4 is a system diagram showing a configuration example of a refrigeration cycle having a dual air conditioner configuration.
This system mixes the cold air generated by the refrigeration cycle for the air conditioning on the front seat side and the warm air generated from the engine cooling water, and the air conditioning for the rear seat side is performed by the cold air or hot air generated by the refrigeration cycle. It is configured. That is, the refrigeration cycle on the front seat side includes a compressor 101 that compresses the refrigerant, a condenser 102 that condenses the compressed high-temperature and high-pressure refrigerant, a check valve 103, and a supercooling degree control type expansion that decompresses the condensed refrigerant. It comprises a valve 104, an evaporator 105 disposed on the front seat side for evaporating the decompressed refrigerant, and an accumulator 106, and the refrigeration cycle on the rear seat side includes a supercooling degree control type expansion valve 104 and an evaporator 105 on the front seat side. The supercooling degree control type expansion valve 107 disposed in parallel with the heat exchanger 108 disposed on the rear seat side, functioning as an evaporator during cooling operation, functioning as a condenser during heating operation, and a check valve 109 It is configured. The supercooling degree control type expansion valve 107 is provided with a check valve 110 in parallel so as to bypass the refrigerant flowing from the heat exchanger 108, and on the downstream side of the evaporator 105, an engine cooling water is provided. A heater 111 having a heat source as a heat source is disposed. This system includes a four-way switching valve 112 that is connected to the compressor 101, the condenser 102, the heat exchanger 108, and the check valve 109 and performs switching between cooling operation and heating operation.
[0005]
In the refrigeration cycle having such a configuration, during the cooling operation, the four-way switching valve 112 is switched to the refrigerant passage as shown by a solid line in the figure, and the refrigerant that has been compressed from the compressor 101 is transferred to the four-way switching valve. 112, flows through the condenser 102 and the check valve 103, and then splits into two, one through the supercooling control expansion valve 104 and the evaporator 105 on the front seat side, and the other on the rear seat side The supercooling degree control type expansion valve 107, the heat exchanger 108, the four-way switching valve 112, and the check valve 109 are joined by the accumulator 106 and returned to the compressor 101.
[0006]
During the heating operation, the four-way switching valve 112 is switched to the refrigerant passage as shown by a broken line in the figure, and the refrigerant that has been compressed and discharged from the compressor 101 is first sent from the four-way switching valve 112 to the rear seat side. The heat flows through the heat exchanger 108 and the check valve 110, and then returns to the accumulator 106 through the front-seat supercooling degree expansion valve 104 and the evaporator 105.
[0007]
[Problems to be solved by the invention]
In the configuration example of the refrigeration cycle as described above, the rear seat side supercooling control type expansion is necessary because the refrigerant is throttled and expanded during cooling operation and not expanded during heating operation. A check valve is provided in parallel with the valve.
[0008]
However, in the past, the rear-seat supercooling control type expansion valve and the check valve were configured separately from each other. There is a problem that the man-hour for mounting the air conditioner on the vehicle increases.
[0009]
An object of the present invention is to provide a supercooling degree control type expansion valve that can reduce the installation space and the number of installation steps by integrating the functions of the check valve.
[0010]
[Means for Solving the Problems]
In the present invention, in order to solve the above problem, expansion means for constricting and expanding the refrigerant flowing in the first direction during the cooling operation of the refrigeration cycle, and flowing in the second direction opposite to the first direction during the heating operation Passage means for allowing the refrigerant to pass without being squeezed and expanded , the passage means receiving a refrigerant flowing in the first direction and a second refrigerant passage receiving the refrigerant flowing in the second direction. And a valve body disposed so as to be able to contact and separate from the first refrigerant passage side facing the valve seat, and the expansion means is the valve body of the passage means And a differential pressure valve for controlling the refrigerant flowing in the first direction to have a predetermined degree of supercooling, and formed integrally with the valve body of the passage means on the downstream side of the differential pressure valve. supercooling having a throttle channel which opens into the second refrigerant passage Controlled expansion valve is provided.
[0011]
According to such a supercooling degree control type expansion valve, the refrigerant received in the first refrigerant passage during the cooling operation is throttled and expanded by flowing through the expansion means, and the second refrigerant passage during the heating operation. The refrigerant received in the flow flows so as to bypass the expansion means via the passage means. As described above, since the supercooling degree control type expansion valve having a function of allowing the refrigerant flowing in the reverse direction to flow as it is can be provided, the conventional supercooling degree control type expansion valve and the check valve are configured. As a result, the mounting space can be reduced and the number of mounting steps such as high-pressure refrigerant piping can be reduced.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view showing a configuration of a supercooling degree control type expansion valve according to an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view taken along the line aa in FIG.
[0013]
The supercooling degree control type expansion valve 1 is provided with refrigerant passages 4 and 6 from the left and right sides of the body 2 constituting the body block, respectively. A condenser 102 is connected to the refrigerant passage 4 via, for example, a check valve 103 shown in FIG. 4, and high-pressure refrigerant is supplied thereto during cooling operation of the refrigeration cycle. In FIG. 1, a high-pressure refrigerant is supplied from the refrigerant passage 4 as indicated by an arrow 5, and the supplied refrigerant is expanded and output from the refrigerant passage 6.
[0014]
A cylindrical space 8 is formed in the body 2 from the lower side of FIG. 1 so that the refrigerant passages 4 and 6 communicate with each other. The cylindrical space 8 includes a small-diameter space 81 formed so as to be connected to the refrigerant passage 6 and a large-diameter space 82 formed so as to be connected to the refrigerant passage 4. A valve seat 10 is formed on a connecting surface having 82 steps.
[0015]
In the space 82 formed in the body 2, the valve body 12 is disposed so as to be able to advance and retract in the axial direction so as to face the valve seat 10. The valve body 12 has a columnar shape having a diameter larger than the diameter of the space 81, and as shown in FIG. 2, the three foot pieces 14 are in contact with the peripheral wall surface of the small diameter space 81 on the upper surface thereof. The foot 14 is formed and serves as a guide when the valve body 12 moves back and forth in the axial direction. An annular slit 16 is formed on the upper surface of the valve body 12 so as to be concentric with the axis of the valve body 12 and at a predetermined depth, and the lower surface of the valve body 12 is offset from the axis. Three through holes 18 for the slits 16 are formed at the positions. The slit 16 and the through hole 18 of the valve body 12 constitute a throttle channel for adiabatic expansion of the high-pressure refrigerant.
[0016]
An annular protrusion 20 is formed on the lower surface of the valve body 12, and a housing 26 constituting a space 24 for accommodating the valve body 22 is attached thereto. The valve body 22 is formed at a position where three foot pieces 28 integrally formed extending upward from the outer periphery of the valve body 22 can come into contact with the inner wall surface of the housing 26. Is a guide when moving back and forth in the axial direction. A tapered surface 30 is formed on the lower surface portion of the valve body 22. Further, an oil passage 32 having a minute cross-sectional area is formed in the axial position of the valve body 22 so as to penetrate the valve body 22.
[0017]
An opening 36 is formed on the lower side of the housing 26, and a peripheral portion of the opening 36 constitutes a valve seat 38 that contacts the tapered surface 30 of the valve body 22. Reference numeral 40 denotes a spring which acts to press the valve body 22 against the valve seat 38, and 42 denotes a cap for closing the space 8 of the body 2.
[0018]
That is, the valve body 12 is enclosed in the cylindrical space 82 by the cap 42 while being seated on the valve seat 10 by the spring 44 having a weak spring force. The housing 26 housing the valve body 22 together with the spring 40 is guided along a cylindrical guide hole 46 formed inside the cap 42, and moves forward and backward integrally with the valve body 12 in the axial direction. Do. Note that the lower end portion of the housing 26 is provided with, for example, three sliding contact portions that are in sliding contact with the inner peripheral surface of the guide hole 46 on the outer peripheral surface thereof, and a gap between the sliding contact portions allows the refrigerant to pass therethrough. It is a passage for.
[0019]
An O-ring 50 for sealing the space 8 is fitted on the outer periphery of the cap 42. Further, 52 and 54 are strainers for filtering the refrigerant passing through the refrigerant passages 4 and 6, respectively, and 56 and 58 are screw holes for fixing the main body block of the supercooling degree control type expansion valve 1.
[0020]
Next, the operation when the cooling operation is performed at the normal refrigerant pressure in the supercooling degree control type expansion valve 1 configured as described above will be described.
In normal load operation, when high-pressure refrigerant from the condenser is supplied to the refrigerant passage 4, the refrigerant is filtered by the strainer 52, enters the space 82, and acts on the valve body 12 and the valve body 22. The high-pressure refrigerant acts on the valve body 12 in the same direction as the urging force of the spring 44, and causes the valve body 12 to be seated on the valve seat 10 so as to close the direct flow path between the valve body 12 and the space 81. For the valve body 22, the high-pressure refrigerant enters the guide hole 46 of the cap 42, acts on the valve body 22 through the opening 36 of the housing 26, and resists the urging force of the spring 40. It acts in the direction of pushing away from 38. Therefore, the valve body 22 operates so as to come in contact with and separate from the valve seat 38 in accordance with the balance between the differential pressure between the upstream side and the downstream side and the biasing force of the spring 40, and the space in the housing 26. The flow rate of the refrigerant introduced into 24 is controlled by differential pressure.
[0021]
Thus, the refrigerant that has passed through the valve body 22 that operates as a differential pressure valve is expanded by passing through the slit 16 through the through-hole 18 formed in the valve body 12, and becomes a low-temperature refrigerant that has been decompressed. Then, it is sent from the refrigerant passage 6 to the heat exchanger on the rear seat side.
[0022]
When the refrigeration cycle is operated at a low load or when the compressor is rotating at a low speed, the entire refrigeration cycle is in a low pressure state. Therefore, the valve element 22 is seated on the valve seat 38 by the spring 40 and is closed. Although retained, there is a slight flow of refrigerant through the oil passage 32 formed in the valve body 22. By this flow, circulation of the lubricating oil for the compressor mixed in the refrigerant can be secured, and the seizure of the compressor is prevented.
[0023]
FIG. 3 is a cross-sectional view showing an operation state during heating operation of the supercooling degree control type expansion valve according to the embodiment of the present invention. 3, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0024]
During the heating operation, the flow of the refrigerant is reversed, and the high-pressure refrigerant condensed in the heat exchanger on the rear seat side is supplied to the refrigerant passage 6 from the direction indicated by the arrow 7.
The high-pressure refrigerant supplied from the refrigerant passage 6 to the space 81 directly acts on the large-diameter valve body 12, pulls the valve body 12 away from the valve seat 10 against the biasing force of the spring 44 having a weak spring force, and the space 82 to open the flow path. As a result, the refrigerant supplied to the refrigerant passage 6 flows directly to the refrigerant passage 4 via the space 81, the valve hole, and the space 82.
[0025]
At this time, the valve body 22 in the housing 26 is seated on the valve seat 38 by the biasing force of the spring 40. Thus, the supercooling degree control type expansion valve 1 can squeeze and expand the refrigerant in the flow direction during the cooling operation, and simply allow the refrigerant in the flow direction during the heating operation to pass therethrough.
[0026]
【The invention's effect】
As described above, according to the supercooling degree control type expansion valve of the present invention, for the refrigerant in the flow direction during the cooling operation, the first valve body is closed and the first valve body is closed. The refrigerant is throttled and expanded by the second valve body and the throttle channel constituting the accommodated differential pressure valve, and for the refrigerant in the flow direction during the heating operation, the first valve body opens and the refrigerant is The diaphragm can be passed without being expanded.
[0027]
Therefore, when applied to a refrigeration cycle of a so-called dual air conditioner that air-conditions the front seat side space and the rear seat side space, the functions of the conventional supercooling degree control type expansion valve and check valve are combined into one supercooling function. Because it can be realized with a degree-controlled expansion valve, there is no need to install a conventional supercooling degree-controlled expansion valve and a check valve separately, reducing the installation space and reducing the number of mounting steps such as high-pressure refrigerant piping. Can do.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a supercooling degree control type expansion valve according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view taken along the line aa in FIG.
FIG. 3 is a cross-sectional view showing an operating state during heating operation of the supercooling degree control type expansion valve according to the embodiment of the present invention.
FIG. 4 is a system diagram showing a configuration example of a refrigeration cycle having a dual air-conditioner configuration.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Supercooling degree control-type expansion valve 2 Body 4, 6 Refrigerant passage 8 Space 10 Valve seat 12 Valve body 14 Foot piece 16 Slit 18 Through-hole 20 Annular projection 22 Valve body 24 Space 26 Housing 28 Foot piece 30 Tapered surface 32 Oil passage passage 36 Opening 38 Valve seat 40 Spring 42 Cap 44 Spring 46 Guide hole 50 O-ring 52, 54 Strainer 81 Small diameter space 82 Large diameter space

Claims (4)

Expansion means for constricting and expanding the refrigerant flowing in the first direction during the cooling operation of the refrigeration cycle; and passage means for allowing the refrigerant flowing in the second direction opposite to the first direction during the heating operation to pass without constricting and expanding. equipped with a,
The passage means includes a valve seat formed between a first refrigerant passage receiving the refrigerant flowing in the first direction and a second refrigerant passage receiving the refrigerant flowing in the second direction; A valve body disposed so as to be able to contact and separate from the valve passage from the refrigerant passage side,
The expansion means includes a differential pressure valve that controls the refrigerant stored in the valve body of the passage means to flow in the first direction to have a predetermined degree of supercooling, and the passage means on the downstream side of the differential pressure valve. A supercooling degree control type expansion valve having a throttle passage formed integrally with the valve body and opened to the second refrigerant passage . 2. The supercooling degree control type expansion valve according to claim 1, wherein the valve body of the passage means is urged in a direction to be seated on the valve seat by a spring having a weak spring force. 2. The supercooling degree control type expansion valve according to claim 1, wherein the differential pressure valve includes a bypass means for passing a minimum refrigerant flow rate required for the compressor even in a closed state. 4. The supercooling degree control type expansion valve according to claim 3, wherein the bypass means is a passage having a minute cross-sectional area formed through the valve body of the differential pressure valve.

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