JP4848548B2 - Expansion valve with solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an expansion valve with a solenoid valve of low costs having a power element capable of dispensing with design in which withstand pressure is taken into consideration. <P>SOLUTION: A valve seat to a valve element 25 of the expansion valve and a circular valve element 27 of a stop valve is composed of a piston 16 axially moved forward and backward, a high pressure introduction chamber 18 and a back pressure chamber 19 defined by the piston 16 are respectively connected to an intermediate chamber 20 through orifices 21, 22, and the intermediate chamber 20 is communicated to an expansion valve downstream side through a pilot valve hole 30 opened and closed by the solenoid valve 13. Thus when the electric power is not distributed to the solenoid valve 13, high pressure is introduced to the back pressure chamber 19 through the intermediate chamber 20, and the valve seal is pressed to the circular valve element 27 while separating the valve element 25 from a shaft 41. When the electric power is distributed to the solenoid valve 13, the intermediate chamber 20 is connected to low pressure, the valve seat is separated from the valve element 25, and the valve element 25 is brought into contact with the shaft to be placed under the control of the power element 12. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to an expansion valve with an electromagnetic valve, and more particularly to an expansion valve with an electromagnetic valve used for a rear circuit of an automotive air conditioner capable of independently air-conditioning a front side and a rear side in a vehicle interior.

  Conventionally, as an automotive air conditioner, a front evaporator and its expansion valve, a rear evaporator, and a rear-side air-conditioning control can be independently performed in a vehicle interior. A refrigeration cycle configured by arranging the expansion valve in parallel is used.

  These expansion valves are generally temperature-type expansion valves that sense the outlet temperature of the refrigerant that has exited from the front and rear evaporators and control the flow rate of the refrigerant that is supplied to the front and rear evaporators. ing. In the temperature type expansion valve, the power element senses the refrigerant outlet temperature of the front and rear evaporators, and the valve element is arranged upstream of the valve seat by the shaft extending through the valve hole according to the sensed temperature. The lift amount is controlled so that the refrigerant discharged from the front and rear evaporators maintains a predetermined degree of superheat.

  Thus, in a refrigeration cycle having independent refrigerant circuits on the front side and rear side in the passenger compartment, when the front side refrigeration cycle is used, the rear refrigeration cycle is not necessarily used. Absent. Therefore, an electromagnetic valve that functions as a stop valve is provided in the rear circuit so that the refrigerant does not flow when the rear refrigeration cycle is not used.

  As the electromagnetic valve and the expansion valve used for such applications, an expansion valve with an electromagnetic valve in which these are integrated is proposed in view of installation space, interconnection piping and cost.

  Here, when air conditioning is performed only on the front side, the circuit on the rear side is closed by closing the solenoid valve of the expansion valve with a solenoid valve. Even in such a case, the refrigerant inlet of the expansion valve with a solenoid valve is almost at the same high pressure as the refrigerant inlet of the expansion valve on the front side, and the refrigerant outlet of the expansion valve with the electromagnetic valve is the refrigerant of the front side expansion valve. The same low pressure as the outlet is applied. For this reason, when the expansion valve with a solenoid valve is opened to start the air conditioning on the rear side, a large flow of refrigerant flows into the rear evaporator at once due to a large differential pressure before and after the expansion valve with the solenoid valve. At that time, a very large flow noise of the refrigerant may occur.

  An expansion valve with a solenoid valve that reduces the flow noise of such a refrigerant is known (see, for example, Patent Document 1). According to this expansion valve with a solenoid valve, an expansion valve and a solenoid valve connected in series on the downstream side of the expansion valve are integrally formed, and the expansion valve has a notch groove in the valve seat so as to bypass it. The expansion valve outlet communicates with the pressure equalizing chamber of the power element via the small diameter communication passage, and the large diameter communication passage to the pressure equalizing chamber of the power element returns from the rear evaporator. It arrange | positions in the low pressure channel | path which allows the refrigerant | coolant to pass through, and is arrange | positioned in the state which hold | maintained airtight mutually, so that the refrigerant | coolant exit temperature of a rear evaporator may be detected.

  Thus, when the solenoid valve is closed, the upstream side thereof is equalized to a high pressure because the inlet and outlet of the expansion valve communicate with each other through the notch groove. The pressure equalization chamber of the power element is at a high pressure, so that the temperature sensing chamber of the power element senses the high temperature in the passenger compartment and the diaphragm that partitions the temperature sensing chamber and the pressure equalization chamber tries to displace in the valve opening direction. Overcoming the load, the high pressure pushes the diaphragm back in the valve closing direction. For this reason, the expansion valve is maintained in its closed state by a spring that urges the valve body in the valve closing direction.

Here, when the solenoid valve is opened, the pressure equalizing chamber of the power element communicates with the inlet side of the rear evaporator via the small-diameter communication path, so that the pressure in the pressure equalizing chamber gradually decreases. As the pressure in the pressure equalizing chamber decreases, the power element gradually drives the valve body in the valve opening direction so that the lift amount corresponds to the temperature sensed by the temperature sensing chamber. In other words, the expansion valve gradually opens without opening immediately even when the solenoid valve is opened, so that a large flow noise is generated due to the expansion valve opening suddenly with a high differential pressure across the expansion valve. Occurrence is suppressed.
JP 2003-130500 A

  However, according to the conventional expansion valve with a solenoid valve, in order to realize a slow valve opening operation when the solenoid valve is opened, a high pressure is applied to the pressure equalizing chamber of the power element during the valve closing operation. Therefore, the same power element as that of the front expansion valve cannot be used, and the power element has to be excellent in pressure resistance, resulting in an increase in manufacturing cost.

  The present invention has been made in view of these points, and an object of the present invention is to provide a low-cost expansion valve with a solenoid valve having a power element that does not require a design considering pressure resistance.

  In the present invention, in order to solve the above problems, the power element integrates an expansion valve function for driving the valve body in a valve opening or closing direction via a shaft and a stop valve function for opening and closing the refrigerant passage by an electromagnetic valve. In the expansion valve with a solenoid valve, the valve is opened and closed by the valve element on the end surface opposite to the side where the power element is disposed, so that the valve element can move forward and backward along the shaft. A valve hole is defined by a piston communicating with a port through which the refrigerant after throttle expansion is led through the communication hole, and an end face of the piston opposite to the side where the power element is located, and the valve body is defined by A high pressure introduction chamber accommodated in a state of being urged in a direction in contact with the shaft; a back pressure chamber defined by an end face of the piston on the side where the power element is provided; A pilot valve hole communicated with the high pressure introduction chamber via a first orifice, communicated with the back pressure chamber via a second orifice, and opened and closed by the electromagnetic valve with respect to the communication hole of the piston. An expansion chamber with an electromagnetic valve, wherein the piston has a pressure receiving area on the back pressure chamber side larger than a pressure receiving area on the high pressure introduction chamber side. The

  According to such an expansion valve with a solenoid valve, opening and closing of the refrigerant passage as a stop valve function is performed by moving a piston constituting a valve seat of the stop valve, and the movement of the piston is performed by the solenoid valve in the back pressure chamber. Is switched to high pressure or low pressure. Thereby, the high pressure introduced into the high pressure introduction chamber is transmitted only to the back pressure chamber, and is not transmitted to the power element.

  In the expansion valve with a solenoid valve of the present invention, since the piston constituting the valve seat of the stop valve is moved by switching the pressure in the back pressure chamber to high pressure or low pressure with the solenoid valve, the high pressure is up to the power element. Therefore, there is an advantage that a low-cost expansion valve with a solenoid valve can be provided because a low pressure sensing type generally used for a power element can be used.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a system diagram showing a configuration example of an automotive air conditioner to which an expansion valve with an electromagnetic valve according to the present invention is applied.

  This automotive air conditioner is capable of independently air-conditioning the front side and the rear side of a passenger compartment, and includes a compressor 1, a condenser 2, a receiver 3, a temperature expansion valve 4, a front The refrigeration cycle of the front-side air conditioner is constituted by the evaporator 5, and the expansion valve 6 with a solenoid valve and the rear evaporator 7 according to the present invention are connected in parallel with the circuits of the expansion valve 4 and the front evaporator 5. And constitutes a part of the refrigeration cycle of the rear-side air conditioner.

  The high-temperature and high-pressure refrigerant compressed by the compressor 1 is sent to the condenser 2, where it is heat-exchanged with the air outside the passenger compartment and condensed. The condensed refrigerant is separated into gas and liquid by the receiver 3, and the liquid refrigerant is sent to the expansion valve 4 and the expansion valve 6 with a solenoid valve. In the expansion valve 4, the liquid refrigerant is squeezed and expanded to form a low-temperature / low-pressure gas-liquid mixed refrigerant and sent to the front evaporator 5. The front evaporator 5 evaporates the refrigerant sent from the expansion valve 4 by exchanging heat with the air in the front passenger compartment or the air outside the passenger compartment introduced into the passenger compartment, and the gas refrigerant evaporated here Is returned to the compressor 1. At this time, the expansion valve 4 detects the refrigerant temperature at the outlet of the front evaporator 5 and controls the flow rate of the refrigerant sent to the front evaporator 5 so that the refrigerant at the outlet has a predetermined degree of superheat. .

  Similarly, in the expansion valve 6 with a solenoid valve, the liquid refrigerant separated from the gas and liquid by the receiver 3 is squeezed and expanded to form a low-temperature / low-pressure gas-liquid mixed refrigerant and sent to the rear evaporator 7. The rear evaporator 7 evaporates the refrigerant sent from the expansion valve 6 with a solenoid valve by exchanging heat with the air in the vehicle interior on the rear side, and the evaporated gas refrigerant is used as an expansion valve with a solenoid valve. 6 is returned to the compressor 1. At this time, the expansion valve 6 with a solenoid valve detects the temperature and pressure of the refrigerant returned from the rear evaporator 7 and sends the refrigerant to the rear evaporator 7 so that the refrigerant at the outlet has a predetermined degree of superheat. The flow rate is controlled.

  When the rear-side air conditioner is not used, the expansion valve 6 with a solenoid valve blocks the internal refrigerant passage so that the refrigerant does not flow through the rear-side circuit. Next, a specific configuration example of such an expansion valve 6 with a solenoid valve will be described.

  2 is a longitudinal sectional view showing a configuration example of the expansion valve with a solenoid valve according to the first embodiment in a state in which the solenoid valve is off, FIG. 3 is an enlarged sectional view of a main part of FIG. 2, and FIG. It is a longitudinal cross-sectional view which shows the structural example of the expansion valve with a solenoid valve which concerns on this embodiment in the state at the time of a solenoid valve being ON.

  The expansion valve 6 with a solenoid valve according to the first embodiment has a body 11, and a power element 12 for detecting the temperature and pressure of the refrigerant returned from the rear evaporator 7 is attached to the upper side of the figure. A solenoid valve 13 is attached to the side of the body 11.

  The body 11 has an axial hole 14 dug from the end surface opposite to the side on which the power element 12 is attached to the middle in the longitudinal direction. A cylindrical valve seat guide 15 is press-fitted inside the axial hole 14, and the valve seat guide 15 and the axial hole 14 located behind the valve seat guide 15 are capable of moving forward and backward in the axial direction. Is arranged. The opening end of the axial hole 14 is closed by an adjusting screw 17, and the piston 16 defines the closed cylindrical space into two pressure chambers, a high pressure introduction chamber 18 and a back pressure chamber 19. Will be. The high pressure introduction chamber 18 and the back pressure chamber 19 communicate with an intermediate chamber 20 formed by inserting the electromagnetic valve 13 into a hole formed in the side surface of the body 11 via orifices 21 and 22, respectively.

  The piston 16 has a small-diameter portion that is guided in the axial direction by the valve seat guide 15 and a large-diameter portion that is guided in the axial direction by the axial hole 14 on the back side. A communication hole 23 is formed in the large-diameter portion of the piston 16 so as to cross the inside of the piston 16 so as to cross the piston 16. The small-diameter portion penetrates from the intersection of the communication hole 23 toward the high-pressure introduction chamber 18. The valve hole 24 is formed.

  Although not shown, the high-pressure introduction chamber 18 is formed in a direction perpendicular to the plane of the drawing and communicates with a port that receives a high-temperature / high-pressure refrigerant from the receiver 3. A valve body 25 for opening and closing the valve hole 24 is disposed in the high pressure introduction chamber 18 and constitutes a throttle portion of the expansion valve. The valve body 25 is urged in the valve closing direction by a spring 26, and the urging force is adjusted by the screwing amount of the adjusting screw 17 into the axial hole 14. The valve body 25 is also an annular valve body 27 that abuts against the end face of the piston 16 around the valve hole 24 when the tip is sufficiently inserted into the valve hole 24 and the throttle portion of the expansion valve is substantially closed. Holding. The annular valve body 27 is made of a flexible material, and forms a stop valve that can block the refrigerant passage in the expansion valve 6 with an electromagnetic valve in cooperation with the piston 16.

  The communication hole 23 of the piston 16 communicates with a port 28 formed on the side surface of the body 11, and the refrigerant expanded and expanded by the throttle portion can be supplied from the port 28 to the rear evaporator 7.

  The communication hole 23 of the piston 16 is also communicated with the intermediate chamber 20 by a pilot valve hole 30 of the electromagnetic valve 13. The pilot valve hole 30 has an inner diameter (passage cross-sectional area) larger than that of the orifices 21 and 22. A cylindrical valve seat 31 concentric with the pilot valve hole 30 protrudes from the intermediate chamber 20, and a valve body 32 is disposed so as to be able to contact with and separate from the cylindrical valve seat 31. The valve body 32 is held by a plunger 34 which is disposed in the sleeve 33 so as to be movable back and forth in the axial direction. One end of the sleeve 33 is fitted into a fixture 35 attached to a hole formed in the side surface of the body 11, and a core 36 is fixed to the other end so as to close the open end. A spring 37 is disposed between the plunger 34 and the core 36, and biases the valve body 32 held by the plunger 34 in a direction in which the valve body 32 is seated on the cylindrical valve seat 31. A coil 38 and a yoke 39 are provided around the sleeve 33 and the core 36.

  The back pressure chamber 19 is provided with a spring 40 that urges the piston 16 toward the valve body 25 side. As a result, when the pressure in the back pressure chamber 19 is substantially equal to the pressure in the high pressure introduction chamber 18, the stepped portion that forms the boundary between the small diameter portion and the large diameter portion of the piston 16 is applied to the valve seat guide by the biasing force of the spring 40. It is moved until it abuts against 15.

  In the piston 16, a shaft 41 that transmits the driving force of the power element 12 to the valve body 25 is disposed through the large diameter portion. When the piston 16 is urged by the spring 40 of the back pressure chamber 19 and the stepped portion of the piston 16 is in contact with the valve seat guide 15, that is, the expansion valve 6 with an electromagnetic valve serves as a stop valve. In order to prevent the driving force from the power element 12 from being transmitted to the valve body 25 when it is functioning, it is dimensioned so as to be separated from the valve body 25 without fail.

  The body 11 is also connected to the port 42 to which the low pressure pipe from the rear evaporator 7 is connected to the same side as the port 28 to which the low pressure pipe to the rear evaporator 7 is connected, and to the high pressure pipe from the receiver 3. A port 43 to which a return low-pressure pipe to the compressor 1 is connected is formed on the same side as the port to be connected. The port 42 and the port 43 communicate with each other by a low-pressure passage orthogonal to the inside of the body 11. ing.

  The power element 12 includes a metal upper housing 44 and a lower housing 45, and a flexible thin film is provided between the upper housing 44 and the lower housing 45 so as to partition a space surrounded by these. A metal diaphragm 46 is disposed. The space surrounded by the diaphragm 46 and the upper housing 44 is filled with a gas having the same or equivalent characteristics as the refrigerant circulating in the refrigeration cycle, and constitutes a temperature sensitive room. A diaphragm receiving plate 47 is disposed in a space surrounded by the diaphragm 46 and the lower housing 45. The diaphragm receiving plate 47 has a function of transmitting the displacement of the diaphragm 46 to the shaft 41 and restricting the downward displacement of the diaphragm 46 with the flat portion of the lower housing 45 as a stopper.

  The shaft 41 that transmits the displacement of the diaphragm 46 to the valve body 25 is held by a cylindrical holder 48 that extends in the longitudinal direction of the body 11 through the low-pressure passage. The holder 48 is integrally formed with a radially outwardly extending flange portion at the end of the power element 12, and the flange portion is attached to the body 11 when the lower housing 45 is screwed to the body 11. It is supposed to be fixed. The end of the holder 48 on the piston 16 side is inserted into a hole formed in the body 11 from the intersection center of the low-pressure passage toward the back pressure chamber 19.

  The flange portion of the holder 48 is provided with a spring 49 that applies a lateral load to the shaft 41. The spring 49 has a function of suppressing vibration in the axial direction of the shaft 41 caused by pressure fluctuation of the refrigerant supplied to the expansion valve 6 with the electromagnetic valve. The flange portion of the holder 48 is also formed with a pressure equalizing hole 50 that opens a space in which the diaphragm receiving plate 47 is disposed to a low pressure passage communicating with the port 42 and the port 43.

  And the sealing member is arrange | positioned at the connection part in each part, and airtightness is hold | maintained. That is, in the piston 16, a groove is formed on the outer periphery of the small diameter portion, and the V packing 51 is fitted therein to seal the clearance in the sliding portion between the small diameter portion and the inner wall of the valve seat guide 15. ing. Similarly, the large-diameter portion of the piston 16 is also provided with a groove on its outer periphery, and a V-packing 52 is fitted therein, so that the sliding portion between the large-diameter portion and the inner wall of the axial hole 14 is fitted. The clearance is sealed. The large-diameter portion of the piston 16 also has a V-packing 53 disposed around a hole through which the shaft 41 passes to seal the clearance at the sliding portion between the piston 16 and the shaft 41. In the high pressure introduction chamber 18, an O-ring 55 is fitted in a groove formed between the adjustment screw 17 and the spring receiving member 54 fitted thereto, and the screwed portion of the adjustment screw 17 is sealed. The electromagnetic valve 13 has a groove formed on the outer periphery of the fixture 35, and an O-ring 56 is fitted therein to seal the mounting portion of the electromagnetic valve 13 to the body 11. The threaded portion of the power element 12 to the body 11 has a groove formed on the end surface of the body 11 facing the flat portion of the lower housing 45, and is sealed by fitting an O-ring 57 therewith. Further, an O-ring 58 is disposed at a portion where the holder 48 is inserted into the body 11 from the low pressure passage, and seals the high pressure refrigerant from leaking from the back pressure chamber 19 to the low pressure passage.

  In the expansion valve 6 with an electromagnetic valve having the above configuration, when the rear air conditioner is not used, the electromagnetic valve 13 is in a non-energized state. For this reason, since the plunger 34 is urged away from the core 36 by the spring 37, the valve body 32 held by the plunger 34 is seated on the cylindrical valve seat 31 and the intermediate chamber 20 is closed. It is in. As a result, the high pressure P 1 introduced into the high pressure introduction chamber 18 is introduced into the intermediate chamber 20 through the orifice 21, and further introduced into the back pressure chamber 19 from the intermediate chamber 20 through the orifice 22. . At this time, the pressure P1 in the high pressure introduction chamber 18, the pressure P2 in the intermediate chamber 20, and the pressure P3 in the back pressure chamber 19 are substantially equal. The piston 16 is subjected to substantially the same pressures P1 and P3 at both ends, but the pressure receiving area of the large diameter portion is larger than the pressure receiving area of the small diameter portion, and a large load is applied to the large diameter portion. As shown in FIGS. 2 and 3, the step is stopped at a position where the stepped portion is in contact with the valve seat guide 15. At this time, for example, the temperature of the rear passenger compartment is high, the power element 12 directly senses the temperature, the diaphragm 46 is displaced most downward in the figure, and the shaft 41 that transmits the displacement to the valve body 25 is provided. Even if it has moved to the bottom, the piston 16 is moved beyond the control range of the valve element 25 by the power element 12, and the shaft 41 and the valve element 25 are separated. Accordingly, the tip of the valve body 25 enters the valve hole 24, is further urged by the spring 26, and the annular valve body 27 is pressed against the end face of the piston 16 around the valve hole 24. Since the hole 24 is closed, the flow of the refrigerant is completely stopped, the refrigerant does not flow through the rear circuit, and the expansion valve is in a function stop state.

  Next, when using the rear air conditioner, the solenoid valve 13 is energized. As a result, the plunger 34 is attracted and adsorbed by the core 36 against the urging force of the spring 37, so that the valve body 32 is separated from the cylindrical valve seat 31 and the electromagnetic valve 13 is opened. At this time, the solenoid valve 13 functions as a pilot valve because the pilot valve hole 30 is smaller than the valve hole 24. The pilot valve hole 30 of the electromagnetic valve 13 has a larger passage cross-sectional area than the orifices 21 and 22, so that the refrigerant in the intermediate chamber 20 is more than the high-pressure refrigerant introduced into the intermediate chamber 20 through the orifice 21. The amount led out to the communication hole 23 through the pilot valve hole 30 increases. Therefore, the pressure P2 in the intermediate chamber 20 is gradually reduced, and the pressure P3 in the back pressure chamber 19 is gradually reduced accordingly. As the pressure P3 in the back pressure chamber 19 gradually decreases, the piston 16 slowly moves upward in the figure by the high pressure P1 in the high pressure introduction chamber 18 and the biasing force of the spring 26. At this time, first, the valve body 25 that has moved together with the piston 16 comes into contact with the shaft 41. At this point, the movement of the valve body 25 is stopped, and then only the piston 16 moves away from the valve body 25, and eventually The piston 16 moves until the end surface of the large diameter portion comes into contact with the inner wall of the back pressure chamber 19 on the power element 12 side, and is in a state as shown in FIG. At this time, the pressure P2 of the intermediate chamber 20 and the pressure P3 of the back pressure chamber 19 are substantially equal to the low pressure P4 of the port 28.

  Thereafter, the expansion valve 6 with a solenoid valve operates as a normal expansion valve. That is, as shown in FIG. 4, the valve seat formed on the piston 16 moves away from the valve body 25 and the expansion valve opens, and the valve body 25 is urged by the spring 26 so that it always contacts the end surface of the shaft 41. The power element 12 is placed under control. When the expansion valve is opened, the high-temperature and high-pressure refrigerant supplied from the receiver 3 flows into the valve hole 24 through a gap between the valve body 25 and the valve seat. At this time, the high-temperature and high-pressure refrigerant is squeezed and expanded to become a low-temperature and low-pressure gas-liquid mixed refrigerant, and is sent from the port 28 to the rear evaporator 7 through the communication hole 23.

  In the rear evaporator 7, the refrigerant supplied from the expansion valve 6 with the electromagnetic valve is evaporated by exchanging heat with the air in the vehicle interior on the rear side, and the evaporated refrigerant is returned to the expansion valve 6 with the electromagnetic valve. In the expansion valve 6 with a solenoid valve, the refrigerant returned from the rear evaporator 7 enters the port 42 and is returned from the port 43 to the compressor 1. At this time, in the expansion valve 6 with a solenoid valve, the diaphragm 46 of the power element 12 senses the temperature and pressure of the refrigerant that has passed through the low-pressure passage between the port 42 and the port 43, and the diaphragm according to the temperature and pressure of the refrigerant. The displacement of 46 is transmitted to the valve body 25 through the diaphragm receiving plate 47 and the shaft 41 to control the refrigerant flow rate.

  Thus, immediately after the solenoid valve 13 is energized, the expansion valve 6 with the solenoid valve is fully opened by a slow operation, and thereafter, the temperature of the refrigerant returned from the rear evaporator 7 is predetermined. The lift amount of the valve body 25 is controlled so as to maintain the degree of superheat, and the operation of the normal expansion valve is such that the flow rate of the refrigerant sent to the rear evaporator 7 is controlled.

  FIG. 5 is a longitudinal sectional view showing a configuration example of the expansion valve with a solenoid valve according to the second embodiment in a state where the solenoid valve is off, and FIG. 6 is a diagram of the expansion valve with a solenoid valve according to the second embodiment. It is a longitudinal cross-sectional view which shows a structural example in the state at the time of a solenoid valve being ON.

  Compared with the expansion valve 6 with a solenoid valve according to the first embodiment, the expansion valve 6a with a solenoid valve according to the second embodiment has an O disposed between the back pressure chamber 19 and the low pressure passage. High pressure is not applied to the ring 58 so that high pressure refrigerant leakage to the low pressure passage does not occur. That is, according to the expansion valve 6a with an electromagnetic valve, the piston 16 is integrally formed with a guide portion 60 that is held in a manner that it can be moved forward and backward in the axial direction by a hole into which the end portion of the holder 48 on the piston 16 side is inserted. Yes. The back pressure chamber 19 has a space adjacent to the hole into which the end portion of the holder 48 is inserted and has a diameter larger than that. The V packing 61 is disposed in the space and receives one end of the spring 40. The spring receiving member 62 is press-fitted. As a result, the gap between the guide portion 60 of the piston 16 and the inner wall of the back pressure chamber 19 is sealed by the V packing 61, and the hole in which the O-ring 58 is disposed is connected to the guide portion 60 and the large diameter portion of the piston 16 and the shaft. When the solenoid valve 13 is in a non-energized state and the pilot valve hole 30 of the solenoid valve 13 is closed, the solenoid valve 13 is in a non-energized state. No high pressure has been introduced into the plant. The space surrounded by the O-ring 58 and the end surface of the guide portion 60 functions as a damper chamber and functions to suppress a rapid movement of the piston 16 in the axial direction.

  About another structure, it is the same as the expansion valve 6 with a solenoid valve which concerns on 1st Embodiment. Therefore, when the solenoid valve 13 is in a non-energized state, as shown in FIG. 5, the pilot valve hole 30 is closed, and the high-pressure introduction chamber 18 is connected to the back via the orifice 21, the intermediate chamber 20, and the orifice 22. It communicates with the pressure chamber 19. As a result, the piston 16 resists the urging force of the spring 26 by the urging force acting in the direction of the valve body 25 and the urging force of the spring 40 due to the difference in pressure receiving area between the large diameter portion and the small diameter portion. The expansion valve 6a with a solenoid valve is completely closed.

  When the solenoid valve 13 is energized, the solenoid valve 13 is opened and the intermediate chamber 20 communicates with the low pressure port 28 to become a low pressure. Accordingly, the pressure in the back pressure chamber 19 gradually becomes low. The piston 16 gradually moves away from the valve body 25, and finally stops at the position shown in FIG. Thereafter, the position of the piston 16 does not change, and the lift amount of the valve body 25 is controlled by the power element 12.

  FIG. 7 is a longitudinal sectional view showing a configuration example of the expansion valve with a solenoid valve according to the third embodiment in a state where the solenoid valve is off, and FIG. 8 is a diagram of the expansion valve with a solenoid valve according to the third embodiment. It is a longitudinal cross-sectional view which shows a structural example in the state at the time of a solenoid valve being ON.

  The expansion valve 6b with a solenoid valve according to the third embodiment is a valve seat seal in which the valve seat of the piston 16 presses against the annular valve body 27 as compared with the expansion valve 6a with a solenoid valve according to the second embodiment. The force is strengthened, and the spring 40 that has been biased in the direction in which the piston 16 is pressed against the annular valve body 27 is eliminated.

  That is, in the expansion valve 6b with the electromagnetic valve, the V packing 51 that seals the clearance of the sliding portion between the small diameter portion of the piston 16 and the valve seat guide 15 is held on the valve seat guide 15 side. As a result, the effective pressure receiving area where the piston 16 receives high pressure in the high pressure introduction chamber 18 is an area of a circle whose diameter is the outer diameter of the small diameter portion, and expansion with a solenoid valve according to the first and second embodiments. Since it can be made considerably smaller than the valves 6 and 6a, the force for urging the piston 16 in the direction of the power element 12 is reduced. The sealing force can be increased. Therefore, in this embodiment, the configuration is further simplified by eliminating the need for a spring that biases the piston 16 in the direction in which the piston 16 is pressed against the annular valve body 27. The valve seat guide 15 is provided with a washer 63 so that the V packing 51 does not fall off due to the movement of the piston 16 in the axial direction.

  According to the expansion valve 6b with the solenoid valve having the above configuration, when the solenoid valve 13 is in a non-energized state, as shown in FIG. 7, the pilot valve hole 30 is closed and the high-pressure introduction chamber 18 is an orifice. 21, communicated with the back pressure chamber 19 through the intermediate chamber 20 and the orifice 22. As a result, the piston 16 is pressed against the annular valve element 27 against the urging force of the spring 26 by the urging force acting in the direction of the valve element 25 due to the difference in pressure receiving area between the large diameter part and the small diameter part. The attached expansion valve 6b is completely closed.

  When the solenoid valve 13 is energized, the solenoid valve 13 is opened and the intermediate chamber 20 communicates with the low pressure port 28 to become a low pressure. Accordingly, the pressure in the back pressure chamber 19 gradually becomes low. The piston 16 gradually moves away from the valve element 25, and finally stops at the position shown in FIG. Thereafter, the position of the piston 16 does not change, and the lift amount of the valve body 25 is controlled by the power element 12.

It is a system figure showing an example of composition of a car air-conditioner to which an expansion valve with a solenoid valve by the present invention is applied. It is a longitudinal cross-sectional view which shows the structural example of the expansion valve with a solenoid valve which concerns on 1st Embodiment in the state at the time of a solenoid valve being OFF. It is a principal part expanded sectional view of FIG. It is a longitudinal cross-sectional view which shows the structural example of the expansion valve with a solenoid valve which concerns on 1st Embodiment in the state at the time of a solenoid valve being ON. It is a longitudinal cross-sectional view which shows the structural example of the expansion valve with a solenoid valve which concerns on 2nd Embodiment in the state at the time of a solenoid valve being OFF. It is a longitudinal cross-sectional view which shows the structural example of the expansion valve with a solenoid valve which concerns on 2nd Embodiment in the state at the time of a solenoid valve being ON. It is a longitudinal cross-sectional view which shows the structural example of the expansion valve with a solenoid valve which concerns on 3rd Embodiment in the state at the time of a solenoid valve being OFF. It is a longitudinal cross-sectional view which shows the structural example of the expansion valve with a solenoid valve which concerns on 3rd Embodiment in the state at the time of a solenoid valve being ON.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Receiver 4 Expansion valve 5 Front evaporator 6, 6a, 6b Expansion valve 7 Rear evaporator 11 Body 12 Power element 13 Solenoid valve 14 Axial hole 15 Valve seat guide 16 Piston 17 Adjustment screw 18 High pressure introduction chamber 19 Back pressure chamber 20 Intermediate chamber 21, 22 Orifice 23 Communication hole 24 Valve hole 25 Valve body 26 Spring 27 Annular valve body 28 Port 30 Pilot valve hole 31 Tubular valve seat 32 Valve body 33 Sleeve 34 Plunger 35 Fixing tool 36 Core 37 Spring 38 Coil 39 Yoke 40 Spring 41 Shaft 42, 43 Port 44 Upper housing 45 Lower housing 46 Diaphragm 47 Diaphragm receiving plate 48 Holder 49 Spring 50 Equal pressure hole 51, 52, 53 V packing 54 Spring receiving Member 55, 56, 57, 58 O-ring 60 Guide part 61 V packing 62 Spring receiving member 63 Washer

Claims (9)

In the expansion valve with an electromagnetic valve, in which the power element integrates the expansion valve function for driving the valve body in the valve opening or closing direction via the shaft and the stop valve function for opening and closing the refrigerant passage by the electromagnetic valve,
A valve hole that is opened and closed by the valve body is opened on the end surface opposite to the side where the power element is provided, and is arranged along the shaft so as to be able to advance and retreat in the axial direction. A piston in communication with a port for extracting the refrigerant after expansion by expansion,
A high-pressure introduction chamber defined by an end face of the piston opposite to the side where the power element is located and accommodated in a state where the valve body is urged in a direction in contact with the shaft;
A back pressure chamber defined by the end face of the piston on the side of the power element;
A pilot valve communicated with the high-pressure introduction chamber via a first orifice, communicated with the back pressure chamber via a second orifice, and opened and closed by the electromagnetic valve with respect to the communication hole of the piston. An intermediate chamber communicated through a hole;
An expansion valve with an electromagnetic valve, wherein the piston has a pressure receiving area on the back pressure chamber side larger than a pressure receiving area on the high pressure introduction chamber side.   The expansion valve with an electromagnetic valve according to claim 1, wherein the pilot valve hole has a passage cross-sectional area larger than that of the first orifice and the second orifice.   The valve body has a shape that is closed by being inserted into the valve hole, and an annular valve body that is closed by abutting against an end face of the piston around the valve hole has a stop valve function. The expansion valve with a solenoid valve according to claim 1, wherein the expansion valve is provided as a valve body.   When the solenoid valve closes the pilot valve hole, the piston is moved in the valve closing direction beyond the control range of the valve body by the power element to a position away from the shaft. The expansion valve with an electromagnetic valve according to claim 1.   The back pressure chamber has a first seal member disposed on the outer periphery of the piston closer to the power element than the communication hole, and a second seal member disposed around a hole through which the shaft of the piston passes. 2. The expansion valve with an electromagnetic valve according to claim 1, wherein a third seal member is disposed around the shaft on the power element side of the back pressure chamber.   The back pressure chamber has a first seal member disposed on the outer periphery of the piston closer to the power element than the communication hole, and extends from the piston to the power element side so as to surround the shaft. The expansion valve with an electromagnetic valve according to claim 1, wherein the expansion valve is formed by disposing a second seal member on the outer periphery of the electromagnetic valve.   A seal member is disposed on an outer periphery of the piston in a portion where the valve hole communicating with the communication hole is provided to seal a sliding portion between the high pressure introduction chamber and the communication hole. The expansion valve with a solenoid valve according to claim 1.   A seal member is disposed on the inner periphery of a valve seat guide that holds the outer periphery of the piston in a portion in which the valve hole communicating with the communication hole is provided so as to advance and retract in the axial direction, and the high-pressure introduction chamber and the communication hole 2. The expansion valve with a solenoid valve according to claim 1, wherein the pressure receiving area on the high pressure introduction chamber side is reduced by sealing a sliding portion between the expansion valve and the electromagnetic valve.   2. The expansion valve with an electromagnetic valve according to claim 1, wherein the back pressure chamber includes a spring for biasing the piston.

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