JP2011235722A - Control valve and air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner for a vehicle that enables good dehumidification performance etc. during heating operation, and a control valve suitable for the air conditioner.SOLUTION: A control valve 6 has a main valve body 124 that opens or closes a main passage connecting directly an upper side and a lower side passages by moving away from or contacting with a main valve hole 120. The main valve body 124 has a main valve 105 that is provided so as to partition the upper side passage, the lower side passage and a back pressure chamber 132, and an electromagnetically-driven pilot valve body 144 that regulates the opening ratio of a sub passage connecting the upper side and the lower side passages through the back pressure chamber 132 by moving away from or contacting with a sub valve hole 140. The pilot valve body 144 is provided with a pilot valve 106 operated, during opening of the main valve 105, so as to control a pressure on the upper side of the main valve 105 to approximate a set pressure according to a supply current value.

Description

  The present invention relates to a control valve that can control the flow of refrigerant from an upstream side to a downstream side, and more particularly, to a control valve that can be suitably applied to a vehicle air conditioner.

  In recent years, in vehicles equipped with an internal combustion engine, the combustion efficiency of the engine has improved, and it has become difficult for the cooling water used as a heat source to rise to the temperature required for heating. On the other hand, in a hybrid vehicle using both an internal combustion engine and an electric motor, the utilization rate of the internal combustion engine is low, so that it is more difficult to use such cooling water. There is no heat source by an internal combustion engine in an electric vehicle. For this reason, a heat pump type vehicle air conditioner that performs cycle operation using a refrigerant not only for cooling but also for heating to dehumidify and heat the vehicle interior has been proposed (see, for example, Patent Document 1).

  Such a vehicle air conditioner has a refrigeration cycle including a compressor, an outdoor heat exchanger, an evaporator, an indoor heat exchanger, etc., and the function of the outdoor heat exchanger is switched between heating operation and cooling operation. It is done. During the heating operation, the outdoor heat exchanger functions as an evaporator. At that time, the indoor heat exchanger dissipates heat while the refrigerant circulates through the refrigeration cycle, and the air in the passenger compartment is heated by the heat. On the other hand, the outdoor heat exchanger functions as a condenser during the cooling operation. At that time, the refrigerant condensed in the outdoor heat exchanger evaporates in the evaporator, and the air in the passenger compartment is cooled by the latent heat of evaporation. At that time, dehumidification is also performed.

Japanese Patent Laid-Open No. 9-240266

  However, in such a vehicle air conditioner, when the outdoor heat exchanger functions as an evaporator during heating operation, if the evaporation amount becomes larger than necessary, sufficient liquid refrigerant is supplied to the evaporator in the vehicle interior. May happen. In this case, the heat exchange in the evaporator is substantially not performed, so that the dehumidifying function in the vehicle interior cannot be properly maintained, and problems such as fogging of the window glass may occur. On the other hand, for example, if a refrigerant having a temperature lower than necessary is passed through the evaporator at an extremely low temperature, the evaporator may be frozen. Therefore, the inventor considered that such problems can be solved if the outdoor heat exchanger can function as an evaporator so that an appropriate amount of liquid refrigerant can be supplied to the evaporator in the passenger compartment. .

  One of the objects of the present invention is to provide a vehicle air-conditioning apparatus that can satisfactorily ensure dehumidifying performance during heating operation, and a control valve suitable for the vehicle air-conditioning apparatus.

  In order to solve the above-described problems, an aspect of the present invention provides a main passage that directly connects an upstream passage and a downstream passage in a pilot-operated control valve that can control the flow of refrigerant from the upstream side to the downstream side. A main valve body that opens and closes the main valve hole, and the main valve body is provided so as to partition the upstream side passage, the downstream side passage, and the back pressure chamber, and the upstream side passage The pilot valve body has an electromagnetically driven pilot valve body that can adjust the opening of the sub-passage that connects the downstream passage and the downstream passage through the back pressure chamber by making contact with and away from the sub-valve hole. And a pilot valve that operates to bring the pressure on the upstream side of the main valve close to the set pressure corresponding to the supply current value.

  According to this aspect, the pilot valve operates by electromagnetic drive, and the opening degree of the main valve can be adjusted by adjusting the opening degree of the sub passage. Since the upstream pressure can be controlled to be a set pressure corresponding to the supply current value, if the set pressure is set appropriately, the upstream pressure can be adjusted appropriately. For this reason, if the said control valve is provided between the heat exchanger and evaporator of a vehicle air conditioner, the flow volume of the refrigerant | coolant introduce | transduced into an evaporator can be ensured also at the time of heating operation. As a result, the humidity function in the passenger compartment can be properly maintained.

  Another aspect of the present invention is a vehicle air conditioner. This vehicle air conditioner is a compressor that compresses and discharges refrigerant, and an outdoor condenser that is disposed outside the vehicle cabin and functions as an outdoor condenser that dissipates heat during cooling operation, and as an outdoor evaporator that evaporates refrigerant during heating operation. A functioning outdoor heat exchanger, an indoor evaporator disposed in the passenger compartment to evaporate the refrigerant, and a downstream side of the outdoor heat exchanger when the indoor evaporator functions and the outdoor heat exchanger functions as an outdoor evaporator An electric control valve that controls the flow of refrigerant from the upstream side to the downstream side, a control unit that controls the supply current to the control valve and adjusts the pressure on the upstream side of the control valve, Is provided. The control valve has a main valve body that opens and closes a main passage directly connecting the upstream passage and the downstream passage in contact with and away from the main valve hole. The main valve body is connected to the upstream passage, the downstream passage, and the back passage. An electromagnetically driven motor that can adjust the opening of the main valve provided to partition the pressure chamber and the sub-passage that connects the upstream passage and the downstream passage through the back pressure chamber by making contact with and separating from the sub-valve hole. The pilot valve body includes a pilot valve that operates to bring the pressure on the upstream side of the main valve closer to the set pressure corresponding to the supply current value when the main valve is opened.

  According to this aspect, when the indoor evaporator functions during heating operation and the outdoor heat exchanger functions as the outdoor evaporator, the pressure on the upstream side of the control valve can be appropriately adjusted, and the refrigerant in the outdoor heat exchanger can be adjusted. The evaporation temperature and thus the evaporation amount can be adjusted. As a result, the amount of refrigerant evaporated in the indoor evaporator can be adjusted. That is, by securing the evaporation amount of the indoor evaporator, the flow rate of the refrigerant introduced into the indoor evaporator can be ensured even during heating operation, thereby maintaining the humidity function in the vehicle interior appropriately. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, the control valve suitable for the air conditioning apparatus for vehicles which can ensure the dehumidification performance etc. at the time of heating operation favorably, and the air conditioning apparatus for vehicles can be provided.

1 is a system configuration diagram illustrating a schematic configuration of a vehicle air conditioning apparatus according to a first embodiment. It is explanatory drawing showing operation | movement of the vehicle air conditioner. It is sectional drawing showing the specific structure of a 2nd control valve. It is explanatory drawing showing the operation state of a 2nd control valve. It is sectional drawing showing the structure and operation | movement of a differential pressure orifice. It is sectional drawing showing the specific structure of the 2nd control valve which concerns on 2nd Embodiment. It is explanatory drawing showing the operation state of a 2nd control valve. It is sectional drawing showing the specific structure of the 2nd control valve which concerns on 3rd Embodiment. It is explanatory drawing showing the operation state of a 2nd control valve. It is sectional drawing showing the specific structure of the 2nd control valve which concerns on 4th Embodiment. It is explanatory drawing showing the operation state of a 2nd control valve.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
First, a first embodiment of the present invention will be described. FIG. 1 is a system configuration diagram illustrating a schematic configuration of the vehicle air conditioning apparatus according to the first embodiment. In the present embodiment, the vehicle air conditioning apparatus of the present invention is embodied as an electric vehicle air conditioning apparatus.

  The vehicle air conditioner 1 includes a compressor 2, an indoor condenser 3, a first control valve 4, an outdoor heat exchanger 5, a second control valve 6, an evaporator 7, and an accumulator 8 that are sequentially connected by piping ( Refrigerant circulation circuit). The vehicle air conditioner 1 is a heat pump type air conditioner that performs air conditioning in the vehicle interior using the heat of the refrigerant in a process in which alternative refrigerant (HFC-134a) as a refrigerant circulates while changing its state in the refrigeration cycle. It is configured as. In the present embodiment, a bypass passage 9 that connects a passage connecting the outdoor heat exchanger 5 and the second control valve 6 and a passage connecting the evaporator 7 and the accumulator 8 is provided. A switching valve 11 is provided.

  The vehicle air conditioner 1 has a duct 10 in which heat exchange of air is performed, and an indoor blower 12, an evaporator 7, and an indoor condenser 3 are arranged from the upstream side of the air flow direction in the duct 10. An air mix door 14 is rotatably provided on the upstream side of the indoor condenser 3, and the ratio between the air volume passing through the indoor condenser 3 and the air volume bypassing the indoor condenser 3 is adjusted. Moreover, the outdoor air blower 16 is arrange | positioned so that the outdoor heat exchanger 5 may be opposed.

  The compressor 2 is configured as an electric compressor that houses a motor and a compression mechanism in a housing, is driven by a supply current from a battery (not shown), and the discharge capacity of the refrigerant changes according to the rotational speed of the motor. As this compressor 2, various types of compressors such as a reciprocating type, a rotary type and a scroll type can be adopted. However, since the electric compressor itself is publicly known, the description thereof is omitted.

  The indoor condenser 3 is provided in the vehicle interior and functions as an auxiliary condenser that dissipates the refrigerant separately from the outdoor heat exchanger 5. That is, the high-temperature and high-pressure refrigerant discharged from the compressor 2 dissipates heat when passing through the indoor condenser 3. The air distributed according to the opening degree of the air mix door 14 undergoes heat exchange in the process of passing through the indoor condenser 3.

  The first control valve 4 adjusts the opening of the main passage that connects the indoor condenser 3 and the outdoor heat exchanger 5. The first control valve 4 includes a valve portion that opens and closes the main passage and a solenoid that drives the valve portion, and opens and closes the valve portion depending on the presence or absence of supply current. A bypass passage that bypasses the main passage before and after the first control valve 4 is provided, and an orifice 18 is provided in the bypass passage. Although the opening area of the orifice 18 is sufficiently smaller than the opening area when the first control valve 4 is opened, the orifice 18 is provided in parallel with the first control valve 4 in this way, so that the first control valve 4 Even when the valve is closed, the flow of the refrigerant at a predetermined flow rate is allowed.

  The outdoor heat exchanger 5 is disposed outside the passenger compartment and functions as an outdoor condenser that radiates the refrigerant that passes through the interior during the cooling operation, and functions as an outdoor evaporator that evaporates the refrigerant that passes through the interior during the heating operation. The outdoor blower 16 is a suction type blower, and introduces outside air by rotationally driving an axial fan with a motor. The outdoor heat exchanger 5 exchanges heat between the outside air and the refrigerant.

  The second control valve 6 adjusts the opening of the main passage that connects the outdoor heat exchanger 5 and the evaporator 7. The second control valve 6 includes a valve portion that opens and closes the main passage and a solenoid that drives the valve portion, and adjusts the opening of the valve portion according to the supply current value. The second control valve 6 is configured to be able to function as a constant pressure valve that operates so that its upstream pressure becomes a constant value (set pressure) corresponding to the supply current value. That is, the valve portion of the second control valve 6 operates autonomously so that the upstream pressure becomes a value associated with the supply current value to the solenoid.

  A bypass passage 13 is provided so as to bypass the front and rear of the second control valve 6, and a differential pressure orifice 20 is provided in the bypass passage 13. That is, when the differential pressure orifice 20 is provided in parallel with the second control valve 6 and the front-rear differential pressure becomes higher than a preset differential pressure (set differential pressure) even when the second control valve 6 is closed, Allow a predetermined flow rate of refrigerant flow. The differential pressure orifice 20 is formed by integrating a differential pressure valve and an orifice, and the opening area of the orifice is sufficiently smaller than the opening area when the second control valve 6 is fully opened. The structures of the second control valve 6 and the differential pressure orifice 20 will be described in detail later.

  The evaporator 7 is arrange | positioned in a vehicle interior, and functions as an indoor evaporator which evaporates the refrigerant | coolant which passes the inside. That is, the refrigerant having a low temperature and low pressure due to the passage of the second control valve 6 evaporates when passing through the evaporator 7. The air introduced from the upstream side of the duct 10 is cooled by the latent heat of vaporization. At this time, the cooled and dehumidified air is distributed into one that passes through the indoor condenser 3 and one that bypasses the indoor condenser 3 according to the opening of the air mix door 14. The air passing through the indoor condenser 3 is heated during the passage process. The air that has passed through the indoor condenser 3 and the bypassed air are mixed on the downstream side of the indoor condenser 3, adjusted to a target temperature, and supplied to the interior of the vehicle from a blower outlet (not shown). For example, the air is blown out from a vent outlet, a foot outlet, a differential outlet, or the like toward a predetermined position in the vehicle interior.

  The accumulator 8 is a device that separates and stores the refrigerant sent from the evaporator, and has a liquid phase part and a gas phase part. For this reason, even if liquid refrigerant more than expected is derived from the evaporator 7, the liquid refrigerant can be stored in the liquid phase part, and the refrigerant in the gas phase part can be derived to the compressor 2. As a result, the compression operation of the compressor 2 is not hindered. On the other hand, in the present embodiment, a part of the refrigerant in the liquid phase portion can be supplied to the compressor 2, and a necessary amount of lubricating oil can be returned to the compressor 2.

  The switching valve 11 switches whether or not the refrigerant derived from the outdoor heat exchanger 5 is allowed to flow through the bypass passage 9. In the present embodiment, the switching valve 11 is composed of an electromagnetically driven on / off valve that is opened by energization. In particular, when the external temperature is low and the evaporator 7 is expected to freeze, The control valve 6 is closed to block the passage leading to the evaporator 7, and the switching valve 11 is opened to open the bypass passage 9 that bypasses the evaporator 7. During that time, the evaporator 7 is warmed by the air passing through the duct 10, thereby preventing freezing. In addition, since a well-known thing can be used about such an on-off valve itself, the detailed description is abbreviate | omitted.

  The vehicle air conditioner 1 configured as described above is controlled by the control unit 100. The control unit 100 includes a CPU that executes various arithmetic processes, a ROM that stores various control programs, a RAM that is used as a work area for data storage and program execution, an input / output interface, and the like. Signals from various sensors and switches (not shown) installed in the vehicle air conditioner 1 are input to the control unit 100. The control unit 100 calculates the control amount of each actuator in order to realize the room temperature set by the vehicle occupant, and outputs a control signal to the drive circuit of each actuator. In the illustrated example, the control unit 100 performs the opening / closing control of the first control valve 4, the opening / closing control of the second control valve 6, the opening / closing switching control of the switching valve 11, the compressor 2, the indoor fan 12, the outdoor fan 16, and The drive control of the air mix door 14 is also executed.

  The control unit 100 has a PWM output unit that outputs a pulse signal having a duty ratio set in the drive circuit of the second control valve 6, but a detailed description thereof is omitted because the configuration itself is employed. To do. The control unit 100 determines the set pressure based on predetermined external information detected by various sensors such as the temperature inside and outside the vehicle interior and the temperature of the air blown from the evaporator 7 during heating operation, and the second control valve The energization control is performed so that the upstream pressure of 6 becomes the set pressure.

  In the present embodiment, since the suction pressure of the compressor 2 (the downstream pressure of the second control valve 6) is controlled to become the target pressure, the downstream pressure of the second control valve 6 is adjusted as a result. become. On the other hand, by independently controlling the upstream pressure by the second control valve 6, the liquid refrigerant can be reliably introduced into the evaporator 7 as described later, and the dehumidifying performance can be ensured. The control unit 100 sets an appropriate value of the upstream pressure of the second control valve 6 as a set pressure based on the external information, and supplies a current for realizing the set pressure to the second control valve 6. The valve portion of the second control valve 6 operates autonomously so as to obtain an upstream pressure corresponding to the supply current value, and adjusts the opening degree.

  Next, operation | movement of the refrigerating cycle of this embodiment is demonstrated. FIG. 2 is an explanatory diagram illustrating the operation of the vehicle air conditioner. (A) shows the state during cooling operation, (B) shows the state during heating operation, and (C) shows the state during specific heating operation. The “cooling operation” here is an operation state in which the cooling function functions more than the heating function, and the “heating operation” is an operation state in which the heating function functions more than the cooling function. The “operation” is a heating operation that does not cause the evaporator 7 to function substantially, and is appropriately executed during the heating operation according to the external environment or the like.

  The upper part of each figure shows a Mollier diagram for explaining the operation of the refrigeration cycle. The horizontal axis represents enthalpy, and the vertical axis represents various pressures. The lower part of each figure shows the operating state of the refrigeration cycle. Thick lines and arrows in the figure indicate the flow of the refrigerant, and symbols a to f correspond to those in the Mollier diagram. Further, “x” in the figure indicates that the flow of the refrigerant is blocked. The lower part of the figure corresponds to FIG. 1, but is simplified for convenience, for example, illustration of the air mix door 14 is omitted.

  As shown in FIG. 2A, during the cooling operation, the first control valve 4 is opened, while the main valve (described later) of the second control valve 6 is closed. The switching valve 11 blocks the bypass passage 9. At this time, the outdoor heat exchanger 5 functions as an outdoor condenser. That is, the refrigerant discharged from the compressor 2 circulates and compresses through the indoor condenser 3, the first control valve 4, the outdoor heat exchanger 5, the differential pressure orifice 20, the evaporator 7, and the accumulator 8 in this order. Return to Machine 2. A part of the refrigerant derived from the indoor condenser 3 passes through the orifice 18, but its flow rate is considerably smaller than the flow rate through the first control valve 4.

  That is, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 is condensed by passing through the indoor condenser 3 and the outdoor heat exchanger 5, is adiabatically expanded at the differential pressure orifice 20, and is supplied with cold / low-pressure gas-liquid. A two-phase refrigerant is introduced into the evaporator 7. And it evaporates in the process which passes the evaporator 7, and cools and dehumidifies the air in a vehicle interior. At this time, the opening degree of the air mix door 14 is appropriately adjusted, and the temperature of the air is adjusted.

  On the other hand, as shown in FIG. 2B, during the heating operation, the first control valve 4 is closed while the second control valve 6 is opened. The switching valve 11 blocks the bypass passage 9. At this time, the air mix door 14 is driven to have an appropriate opening degree according to the temperature setting. At this time, the outdoor heat exchanger 5 functions as an outdoor evaporator. That is, the refrigerant discharged from the compressor 2 circulates in the order of the indoor condenser 3, the orifice 18, the outdoor heat exchanger 5, the second control valve 6, the evaporator 7, and the accumulator 8, and circulates in the compressor 2. Return to.

  That is, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 is condensed through the indoor condenser 3, is adiabatically expanded at the orifice 18, is evaporated at the outdoor heat exchanger 5, and is further controlled by the second control valve 6. Is adiabatic and expanded in the form of a gas-liquid two-phase refrigerant of low temperature and low pressure and passes through the evaporator 7. That is, the refrigerant sequentially evaporates in the process of passing through the outdoor heat exchanger 5 and the evaporator 7, but the air in the passenger compartment is cooled and dehumidified by the latent heat of vaporization in the subsequent evaporator 7. In other words, the air cooled and dehumidified by the evaporator 7 is heated by passing through the indoor condenser 3, heated appropriately, and supplied into the vehicle.

  As shown in the upper part of FIG. 2B, at this time, the amount of evaporation in the outdoor heat exchanger 5 is adjusted by controlling the upstream pressure P 1 of the second control valve 6. As shown in the figure, when the set value (set pressure Pset) of the upstream pressure P1 is set relatively high, the evaporation amount in the outdoor heat exchanger 5 becomes relatively small as shown by the solid line portion ( The amount of evaporation in the evaporator 7 becomes relatively large). Conversely, when the set pressure Pset is set relatively low, the evaporation amount in the outdoor heat exchanger 5 becomes relatively large as shown by the two-dot chain line portion (the evaporation amount in the evaporator 7 is relatively high). To be smaller).

  The control unit 100 controls the amount of heat exchange in the evaporator 7 in the process of realizing the set temperature. At this time, by appropriately setting the set pressure Pset, the amount of evaporation of the circulating refrigerant in the outdoor heat exchanger 5 is controlled. Adjust. That is, the control unit 100 calculates the upstream pressure P1 of the second control valve 6 based on the external information and sets it as the set pressure Pset, and supplies the current for realizing the set pressure Pset to the second control valve 6. Supply. Thereby, the ratio of the evaporation amount between the outdoor heat exchanger 5 and the evaporator 7 can be adjusted, the evaporation amount in the evaporator 7 can be secured, and the dehumidifying function can be secured.

  Further, as shown in FIG. 2C, during the specific heating operation, the first control valve 4 is closed as in the heating operation. At this time, the second control valve 6 is closed, the switching valve 11 is opened, and the refrigerant passage is switched to the bypass passage 9. As a result, the differential pressure across the second control valve 6 decreases (substantially becomes zero), and the closed state of the differential pressure orifice 20 is also maintained. That is, the passage leading to the evaporator 7 is blocked and the bypass passage 9 is opened. For this reason, the refrigerant bypasses without passing through the evaporator 7. Thereby, since the low-temperature and low-pressure liquid refrigerant is temporarily not supplied to the evaporator 7, it is possible to suppress the temperature of the evaporator 7 from becoming extremely low and freezing. At this time, the evaporator 7 is warmed by the air passing through the duct 10.

  In the present embodiment, when the outside air temperature is a preset very low temperature (for example, −10 ° C. or lower), the control unit 100 performs the heating operation illustrated in FIG. 2B and the specific heating illustrated in FIG. The operation is used together with the operation, and control is performed so that these are switched alternately. Thereby, while ensuring dehumidification performance by heating operation, freezing of the evaporator 7 can be prevented by specific heating operation.

Next, a specific configuration of the second control valve 6 will be described.
FIG. 3 is a cross-sectional view illustrating a specific configuration of the second control valve. In the following description, for the sake of convenience, the positional relationship between the structures may be expressed based on the illustrated state.
The second control valve 6 is configured as a pilot-actuated control valve capable of controlling the flow of fluid so that the upstream pressure thereof becomes a set pressure corresponding to the supply current value. The second control valve 6 is configured by assembling a valve body 101 and a solenoid 102.

  The valve body 101 is configured by coaxially housing a main valve 105 and a pilot valve 106 in a bottomed cylindrical body 103. An inlet port 110 communicating with the upstream passage of the refrigeration cycle is provided on one side of the body 103, and an outlet port 112 communicating with the downstream passage of the refrigeration cycle is provided on the other side. . A partition wall 114 extending radially inward is provided in the center of the body 103. The partition wall 114 partitions the body 103 into a high pressure side pressure chamber 116 and a low pressure side pressure chamber 118. The pressure chamber 116 communicates with the inlet port 110 and the pressure chamber 118 communicates with the outlet port 112.

  A main valve hole 120 is formed by an annular inner peripheral portion of the partition wall 114, and a main valve seat 122 is formed by an upstream opening end portion thereof. A main valve body 124 is disposed in the pressure chamber 116. The main valve body 124 has a bottomed cylindrical main body, and the bottom peripheral edge of the main body opens and closes the main valve seat 122 to open and close the main valve 105. A plurality of legs 131 are extended downward from the inner periphery of the peripheral edge of the bottom (only one is shown in the figure), and are slidably supported by the inner peripheral surface of the main valve hole 120. ing.

  On the other hand, the upper end opening of the main valve body 124 is provided with a flange portion 126 extending outward in the radial direction, and is slidably supported on the inner peripheral surface of the body 103. A sealing O-ring 128 is fitted on the outer peripheral surface of the flange portion 126. The flange portion 126 divides the pressure chamber 116 into a high pressure chamber 130 and a back pressure chamber 132. An annular stopper 134 is press-fitted and fitted inside the flange 126 at the upper end opening of the main valve body 124. A plurality of legs 136 are extended upward from the inner peripheral edge of the stopper 134 (only one is shown in the figure) and extend to the inside of the solenoid 102.

  Further, a leak passage 138 having a small cross section that communicates the inside and the outside is formed in the side portion of the main valve body 124. That is, a part of the refrigerant introduced into the inlet port 110 is introduced into the internal space S of the main valve body 124 through the leak passage 138, passes through the inside of the stopper 134, and is introduced into the back pressure chamber 132. A sub valve hole 140 is formed in the center of the bottom of the main valve body 124 to communicate the inside and the outside in the axial direction. A sub valve seat 142 is formed by the upstream opening edge of the sub valve hole 140. As will be described later, the pilot valve element 144 constituting the pilot valve 106 is attached to and detached from the auxiliary valve seat 142 according to the control state to open and close the auxiliary valve hole 140. The passage connecting the high pressure chamber 130 and the pressure chamber 118 via the main valve 105 constitutes the “main passage” in the second control valve 6, and connecting the high pressure chamber 130 and the pressure chamber 118 via the pilot valve 106. The passage constitutes a “sub-passage” in the second control valve 6.

  The pilot valve body 144 is disposed in a hollow housing 146, a diaphragm 148 (flexible member) disposed so as to partition the inside of the housing 146 into a sealed space S1 and an open space S2, and the sealed space S1. A spring 150 (biasing member) and a reaction force transmission member 151 accommodated in the open space S2 are provided. The reaction force transmission member 151 has a plurality of legs 152 (only one is shown in the figure) that extends upward through the housing 146. The open space S <b> 2 communicates with the back pressure chamber 132 through the internal space S of the main valve body 124.

  The housing 146 includes a bottomed stepped cylindrical first housing 153 and a second housing 154 both made of stainless steel. The openings are abutted so that the outer edge of the diaphragm 148 made of a thin metal plate is sandwiched between the openings. Assembled. The housing 146 is formed in a container shape by performing outer periphery welding along the joint portion with the diaphragm 148 sandwiched between the first housing 153 and the second housing 154. Since this welding is performed in a vacuum atmosphere, the sealed space S1 is in a vacuum state, but the sealed space S1 may be filled with air or the like.

  The first housing 153 is fixed to the first plunger 171 of the solenoid 102 at the upper bottom thereof. The first housing 153 is provided with a through hole 155 through which each of the plurality of legs 152 of the reaction force transmission member 151 passes. The inside of the first housing 153 communicates with the internal space S through the through hole 155, and an intermediate pressure Pp is introduced. The diaphragm 148 detects the intermediate pressure Pp and is displaced in the opening / closing direction of the pilot valve 106. On the other hand, the center of the bottom portion of the second housing 154 protrudes in a conical shape downward, and the tapered portion constitutes a valve body portion 156 that is attached to and detached from the auxiliary valve seat 142.

  A disk 157 made of stainless steel is in contact with the end surface of the diaphragm 148 on the second housing 154 side, and a set load adjusting spring 150 is interposed between the disk 157 and the second housing 154. When the peripheral edge of the disk 157 is locked to the second housing 154, the downward displacement of the diaphragm 148 is restricted.

  A disc-shaped reaction force transmission member 151 made of stainless steel is in contact with the central portion of the surface of the diaphragm 148 on the first housing 153 side. At a plurality of locations on the outer peripheral portion of the reaction force transmission member 151, leg portions 152 that extend upward (that is, on the side opposite to the diaphragm 148) and project from the through hole 155 of the first housing 153 are provided. These legs 152 can be attached to and detached from the lower surface of the stopper 134 by the operation of the diaphragm 148.

  In the configuration as described above, the pressure P1 in the upstream high-pressure chamber 130 (referred to as “upstream pressure P1”) becomes the intermediate pressure Pp in the internal space S through the leak passage 138 and is introduced into the back pressure chamber 132. On the other hand, the pressure is reduced through the main valve 105 to a pressure P2 (referred to as “downstream pressure P2”). The intermediate pressure Pp varies depending on the open / close state of the pilot valve 106.

  On the other hand, the solenoid 102 has a bottomed cylindrical sleeve 170 attached to seal the upper end opening of the body 103. In the sleeve 170, a first plunger 171 (corresponding to “first movable iron core”) and a second plunger 172 (corresponding to “second movable iron core”) are accommodated so as to face each other in the axial direction. Has been. A bobbin 173 is provided on the outer periphery of the sleeve 170, and an electromagnetic coil 174 is wound around the bobbin 173. A case 176 is provided so as to cover the electromagnetic coil 174 from the outside. The sleeve 170 penetrates the case 176 in the axial direction. A current-carrying harness 178 is drawn out from the electromagnetic coil 174.

  The first plunger 171 has a cylindrical shape, and a plurality of slits 180 (one of which is shown in the figure) extending in the axial direction are provided on the outer peripheral portion thereof. The aforementioned leg portion 136 of the main valve body 124 extends upward through this slit 180. The pilot valve body 144 is joined to the lower end portion of the first plunger 171 at the upper end portion of the first housing 153. That is, the pilot valve body 144 operates integrally with the first plunger 171.

  The second plunger 172 has a cylindrical shape, and a partition wall 182 is provided at the center of the inside thereof. A ventilation hole is formed in the center of the partition 182. The second plunger 172 contacts and supports the upper end surface of the leg 136 at the lower end surface thereof. Between the first plunger 171 and the second plunger 172, a spring 184 (corresponding to an “urging member”) that biases the pilot valve body 144 in the valve closing direction via the first plunger 171 is interposed. ing. A spring 186 that biases the main valve body 124 in the valve closing direction via the second plunger 172 is interposed between the second plunger 172 and the sleeve 170. That is, the main valve body 124 can operate integrally with the second plunger 172.

The second control valve 6 configured as described above functions as a pilot-operated control valve capable of controlling the flow of fluid so that the upstream pressure becomes a set pressure corresponding to the supply current value. Hereinafter, the operation will be described in detail.
FIG. 4 is an explanatory diagram showing the operating state of the second control valve. FIG. 4 shows a control state in which the solenoid 102 is turned on (energized state) (corresponding to FIG. 2B). Note that FIG. 3 described above shows a state in which the solenoid 102 is turned off (corresponding to FIG. 2A).

  As shown in FIG. 3, the second control valve 6 does not perform constant pressure control in a state where the solenoid 102 is turned off, and maintains the valve closed state. At this time, the differential pressure orifice 20 functions as an expansion device as will be described later. That is, since no solenoid force acts on the second control valve 6, the pilot valve body 144 is urged in the valve closing direction by the spring 184, and the pilot valve 106 is closed. On the other hand, the main valve body 124 is biased in the valve closing direction by the spring 186 via the second plunger 172, and the main valve 105 is also closed. At this time, since the refrigerant is introduced into the back pressure chamber 132 from the upstream side through the leak passage 138, the intermediate pressure Pp becomes equal to the upstream pressure P1.

  On the other hand, as shown in FIG. 4, when the solenoid 102 is turned on, the second control valve 6 functions as a constant pressure valve that operates so that the upstream pressure P1 becomes a set pressure Pset corresponding to the supply current value. . That is, since the second control valve 6 is attracted by the solenoid force between the first plunger 171 and the second plunger 172, the pilot valve body 144 is urged in the valve opening direction, and the pilot valve 106 is opened. It becomes a valve state. As a result, the intermediate pressure Pp decreases, and the main valve body 124 operates in the valve opening direction under the influence of the differential pressure (P1-Pp) between the upstream pressure P1 and the intermediate pressure Pp, and the main valve 105 opens. I speak.

  At this time, the refrigerant introduced from the upstream side through the inlet port 110 is decompressed and expanded through the opened main valve 105, and is led out to the downstream side through the outlet port 112. Further, a part of the refrigerant introduced through the inlet port 110 is introduced into the back pressure chamber 132 through the leak passage 138, led out to the pressure chamber 118 through the pilot valve 106, and through the outlet port 112. Derived downstream. At this time, the opening degree of the main valve 105 is adjusted so that the upstream pressure P1 becomes the set pressure Pset.

  In this constant pressure control state, when the upstream pressure P1 becomes larger than the set differential pressure Pset, the intermediate pressure Pp increases, so that the diaphragm 148 is displaced in a direction to reduce the sealed space S1. At this time, since the reaction force transmission member 151 is locked to the stopper 134 by the solenoid force, the housing 146 moves relatively upward, and the opening degree of the pilot valve 106 is increased. As a result, since the intermediate pressure Pp decreases, the main valve body 124 operates in the valve opening direction and changes in the direction in which the upstream pressure P1 decreases.

  On the contrary, when the upstream pressure P1 becomes smaller than the set differential pressure Pset, the diaphragm 148 is displaced in the direction of expanding the sealed space S1. At this time, since the reaction force transmission member 151 is locked to the stopper 134 by the solenoid force, the housing 146 operates relatively downward, and the opening degree of the pilot valve 106 is reduced. As a result, since the intermediate pressure Pp increases, the main valve body 124 operates in the valve closing direction, and the upstream pressure P1 changes in the increasing direction. In this way, the upstream pressure P1 is maintained at the set pressure Pset.

FIG. 5 is a cross-sectional view showing the configuration and operation of the differential pressure orifice. (A) shows a valve closing start state, (B) shows a valve open state, and (C) shows a fully open state.
The differential pressure orifice 20 includes a cylindrical body 322 and a bottomed stepped cylindrical valve body 363 disposed in the body 322. The upstream end of the body 322 is provided with a port 324 communicating with the upstream passage, and the downstream end is provided with a port 326 communicating with the downstream passage. A stepped cylindrical guide member 328 is coaxially disposed at the center in the longitudinal direction of the body 322. The guide member 328 has a flange portion 330 extending radially outward in the upstream half thereof, and is press-fitted into the body 322 via the flange portion 330. A guide hole 329 is formed inside the guide member 328.

  A partition wall 332 extending radially inward is provided at a position upstream of the guide member 328 in the body 322. A valve hole 333 is formed by the annular inner peripheral portion of the partition wall 332. A valve seat 335 is formed by the downstream opening edge of the valve hole 333. A high pressure chamber 336 is formed on the upstream side of the partition wall 332, an intermediate pressure chamber 338 is formed between the partition wall 332 and the guide member 328, and a low pressure chamber 340 is formed on the downstream side of the guide member 328.

  The valve body 363 is formed by integrally forming a valve body portion 364 and an orifice portion 365, and the orifice portion 365 is disposed so as to penetrate the guide hole 329 and is slidably supported by the guide member 328. ing. The valve body portion 364 is disposed in the intermediate pressure chamber 338 and is connected to the upstream side of the orifice portion 365. A valve member 342 made of an elastic material (rubber in the present embodiment) is fitted to the distal end portion of the valve body portion 364. The valve body 363 opens and closes the communication path 159 when the valve member 342 is attached to and detached from the valve seat 335.

  The orifice portion 365 has an upstream end opened at the intermediate pressure chamber 338 and a downstream end opened at the low pressure chamber 340. That is, an orifice passage 366 having a small cross section that connects the intermediate pressure chamber 338 and the low pressure chamber 340 is formed inside the orifice portion 365. As illustrated, the orifice passage 366 is formed to extend in the opening / closing direction of the valve body 363. The orifice portion 365 has an outer diameter slightly enlarged at the connection portion with the valve body portion 364, and when the enlarged diameter portion is locked to the flange portion 330, the downstream displacement is restricted. A spring 169 (which functions as an “urging member”) for biasing the valve body 363 in the valve closing direction is interposed between the valve body portion 364 and the flange portion 330.

  With such a configuration, the upstream pressure P1 introduced from the upstream passage through the port 324 is reduced through the valve portion to become the intermediate pressure Pp3 in the intermediate pressure chamber 338, and further through the orifice passage 366. By reducing the pressure, the downstream pressure P2 is obtained. However, since the inner diameter A of the valve hole 333 is equal to the inner diameter B of the guide hole 329, the influence of the intermediate pressure Pp3 acting on the valve body 363 is cancelled. That is, the differential pressure orifice 20 functions as a differential pressure valve that opens when the front-rear differential pressure (P1-P2) exceeds a set value (second set differential pressure), and as a check valve that prevents backflow of refrigerant. Function. This set value is set by the load of the spring 169.

  That is, the differential pressure orifice 20 is closed as shown in FIG. 5A when the front-rear differential pressure (P1-P2) is smaller than the set value. At this time, the refrigerant flow in the communication path 159 is blocked. When the front-rear differential pressure (P1-P2) becomes larger than the set value, the differential pressure orifice 20 opens as shown in FIGS. 5B and 5C, and the refrigerant flow in the communication passage 159 is allowed.

  5A, in the state where the valve body 363 is seated on the valve seat 335, the intermediate pressure chamber 338 also has the downstream pressure P2 (intermediate pressure Pp3 = downstream pressure P2). ) And the downstream pressure P2 acts on the inside of the orifice passage 366 over the entire length thereof. As shown in FIG. 5B, the valve body 363 starts to move away from the valve seat 335, and at the same time, the intermediate pressure Pp3 approaches the upstream pressure P1, and the upstream pressure P1 acts on the upstream portion of the orifice passage 366. It becomes like this. Since there is also a pressure loss in the orifice passage 366, a pressure gradient is formed from the upstream end to the downstream end so that fluid friction in the valve opening direction acts on the valve body 363 by the refrigerant passing through the inside of the orifice passage 366. become. As a result, the opening of the valve body 363 is promoted at the same time as the opening of the valve body 363, and the valve body 363 can quickly settle down to the fully opened state as shown in FIG. That is, the valve body 363 can be prevented from staying at a minute opening as shown in FIG. 5B, and the function as the orifice (characteristics set for the orifice) can be exhibited well.

  In this embodiment, when the switching valve 11 is opened with the second control valve 6 closed as shown in FIG. 2C, the differential pressure across the differential pressure orifice 20 (P1-P2). Substantially approaches zero. Therefore, all of the main valve 105, the pilot valve 106, and the differential pressure orifice 20 can be closed. As a result, the refrigerant bypasses without passing through the evaporator 7. Thereby, since the low-temperature and low-pressure liquid refrigerant is temporarily not supplied to the evaporator 7, the temperature of the evaporator 7 is prevented from being extremely low and frozen.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The vehicle air conditioning apparatus according to the present embodiment is the same as the first embodiment except that the structure of the second control valve is different. For this reason, about the component similar to 1st Embodiment, the same code | symbol is attached | subjected etc., and the description is abbreviate | omitted suitably. FIG. 6 is a cross-sectional view illustrating a specific configuration of the second control valve according to the second embodiment.

  The second control valve 26 is configured by assembling the valve main body 201 and the solenoid 202, and is a pilot operated control valve capable of controlling the flow of fluid so that the upstream side pressure becomes a set pressure corresponding to the supply current value. It is configured.

  The valve body 201 is configured by housing a main valve 205 and a pilot valve 206 coaxially in a body 203. An inlet port 110 is provided on one side of the body 203 and an outlet port 112 is provided on the other side. The positional relationship of each port with respect to the body 203 is the same as that of the body 103 of the first embodiment. The opposite is true. An annular partition member 220 is press-fitted into the inner center of the body 103. The partition member 220 partitions the body 203 into a high pressure side pressure chamber 216 and a low pressure side pressure chamber 218. The pressure chamber 216 communicates with the inlet port 110, and the pressure chamber 218 communicates with the outlet port 112. A main valve hole 120 is formed by an annular inner peripheral portion of the partition member 220. A main valve body 224 is disposed so as to straddle the pressure chamber 216 and the pressure chamber 218. The main valve body 224 opens and closes the main valve 205 when a valve body portion 225 provided at the lower end thereof is inserted into and removed from the main valve hole 120.

  On the other hand, a flange portion 226 extending outward in the radial direction is provided at the upper end portion of the main valve body 224, and is slidably supported on the inner peripheral surface of the body 203. An O-ring 128 is fitted on the outer peripheral surface of the flange portion 226. The flange portion 226 divides the pressure chamber 218 into a back pressure chamber 132 and a low pressure chamber 230. In addition, the flange portion 226 is provided with a leak passage 138 having a small cross section that allows the back pressure chamber 132 and the low pressure chamber 230 to communicate with each other, and allows a predetermined amount of refrigerant to flow from the back pressure chamber 132 to the low pressure chamber 230. To do. A passage connecting the pressure chamber 216 and the low pressure chamber 230 via the main valve 205 constitutes a “main passage” in the second control valve 26, and connects the pressure chamber 216 and the low pressure chamber 230 via the pilot valve 206. The passage constitutes a “sub-passage” in the second control valve 26.

  The main valve body 224 is provided with an insertion hole 232 that penetrates the main body in the axial direction, and a sub valve hole 240 is formed by the lower end opening (upstream end), and the sub valve opens by the opening edge. A seat 242 is formed. A shaft 260 extending from the solenoid 202 is slidably inserted into the insertion hole 232, and a pilot valve body 244 is joined to the lower end portion of the shaft 260. The pilot valve body 244 opens and closes the pilot valve 206 by being attached to and detached from the auxiliary valve seat 242 from the upstream side (below) according to the control state. The insertion hole 232 is provided with a communication groove 246 extending in the longitudinal direction, and a pilot passage 262 is formed between the communication groove 246 and the shaft 260. The pilot passage 262 allows the auxiliary valve hole 240 and the back pressure chamber 132 to communicate with each other.

  The pilot valve body 244 has a tapered valve body portion that is attached to and detached from the sub-valve seat 242, and the distal end of the reduced diameter portion that extends upward from the valve body portion is in contact with the lower end surface of the shaft 260. A locking portion 248 that extends outward in the radial direction is provided at the lower end portion of the pilot valve body 244. The locking portion 248 functions as a pressure receiving portion that receives an urging force in the valve closing direction by a pressure sensitive member described later. A spring 249 that urges the pilot valve body 244 in the valve closing direction is interposed between the pilot valve body 244 and the main valve body 224.

  A power element 250 including a bellows 251 as a pressure sensitive member is provided at the lower end portion of the pilot valve body 244. That is, the power element 250 includes a bottomed cylindrical case 252 that is press-fitted into the lower end opening of the pilot valve body 244, and a bellows 251 that is disposed inside and extends and contracts in the axial direction. Consists of including.

  The bellows 251 has a sealed space S1 inside a flexible main body 253. The main body 253 has a bottomed cylindrical shape, and the lower end opening is sealed by welding to the bottom of the case 252. Since this welding is performed in a vacuum atmosphere, the sealed space S1 is in a vacuum state, but the sealed space S1 may be filled with air or the like. A stepped columnar core material 254 is disposed inside the main body 253, and the bottom portion of the core material 254 has a shape along the upper bottom portion of the main body 253. Between the bottom of the case 252 and the core material 254, a spring 256 that biases the main body 253 in the extending direction via the core material 254 is interposed. A communication hole 258 for communicating the inside and the outside is formed in the side portion of the case 252.

  That is, the main body 253 expands and contracts due to a pressure difference between the inside and outside, and the core material 254 is fitted to the pilot valve body 244 when the body 253 expands by a predetermined amount. Thereby, the urging force in the valve closing direction by the power element 250 is applied to the pilot valve body 244. On the other hand, when the main body 253 is reduced, the urging force by the power element 250 can be released. However, when the main body 253 is reduced by a predetermined amount, the lower end surface of the core material 254 is locked to the case 252, and the reduction amount is also restricted. .

  In the configuration as described above, the upstream pressure P1 passes through the pilot valve 206 and becomes the intermediate pressure Pp and is introduced into the back pressure chamber 132, while being reduced through the main valve 205 and becomes the downstream pressure P2. . The intermediate pressure Pp varies depending on the open / close state of the pilot valve 106.

  On the other hand, the solenoid 202 has a bottomed cylindrical sleeve 270 attached so as to seal the upper end opening of the body 203. The sleeve 270 is attached to the body 203 via an O-ring 265. A first plunger 271 and a second plunger 272 are accommodated in the sleeve 170 so as to be opposed to each other in the axial direction. A bobbin 273 is provided on the outer periphery of the sleeve 270, and an electromagnetic coil 274 is wound around the bobbin 273. A metal case 275 is provided so as to cover the electromagnetic coil 274 from the outside. Structures such as the case 275 and the sleeve 270 are covered and protected from the outside by a body 276 formed of a resin mold. . A collar 277 made of a magnetic member constituting a magnetic circuit together with the case 275 is embedded in the body 276. A part of the body 276 also functions as a connector part that exposes one end of the terminal 279 connected to the electromagnetic coil 274.

  The first plunger 271 has a cylindrical shape, and its lower end surface is disposed so as to be able to contact the upper surface of the main valve body 224 (the central upper surface of the flange portion 226). Between the first plunger 271 and the sleeve 270, a spring 278 (functioning as an “urging member”) for biasing the first plunger 271 in the valve opening direction of the main valve body 224 is interposed. That is, the main valve body 224 can operate integrally with the first plunger 271. The shaft 260 passes through the first plunger 271 along its axis, and the upper end thereof is in contact with the second plunger 272. That is, the pilot valve body 244 can operate integrally with the second plunger 272.

FIG. 7 is an explanatory diagram showing the operating state of the second control valve. FIG. 7 shows a control state in which the solenoid 202 is turned on (energized state). Note that FIG. 6 already described represents a state in which the solenoid 202 is turned off.
As shown in FIG. 6, the second control valve 26 does not perform constant pressure control in a state where the solenoid 202 is turned off, and maintains the valve closed state. That is, since the solenoid force does not act on the second control valve 26, the pilot valve body 244 is urged in the valve closing direction by the spring 249, and the pilot valve 206 is closed. For this reason, the intermediate pressure Pp is lowered, the main valve body 224 is urged in the valve closing direction, and the main valve 205 is also closed.

  On the other hand, as shown in FIG. 7, when the solenoid 202 is turned on, the second control valve 26 functions as a constant pressure valve that operates so that the upstream pressure P1 becomes the set pressure Pset corresponding to the supply current value. . That is, in the second control valve 26, since a suction force acts between the first plunger 271 and the second plunger 272 by the solenoid force, the pilot valve body 244 is urged in the valve opening direction, and the pilot valve 206 is opened. It becomes a valve state. As a result, the intermediate pressure Pp increases, so that the main valve body 224 operates in the valve opening direction under the influence of the differential pressure (Pp−P2) between the intermediate pressure Pp and the downstream pressure P2, and the main valve 205 is opened. I speak.

  At this time, the refrigerant introduced from the upstream side through the inlet port 110 is decompressed and expanded through the opened main valve 205 and led out to the downstream side through the outlet port 112. Further, a part of the refrigerant introduced through the inlet port 110 is introduced into the back pressure chamber 132 through the pilot valve 206 and led out downstream through the leak passage 138 and the outlet port 112. At this time, the opening degree of the main valve 205 is adjusted so that the upstream pressure P1 becomes the set pressure Pset.

  In this constant pressure control state, when the upstream pressure P1 becomes larger than the set differential pressure Pset, the bellows 251 is deformed in a direction to reduce the sealed space S1. As a result, the pilot valve body 244 operates in the valve opening direction, and the opening degree of the pilot valve 206 is increased. As a result, since the intermediate pressure Pp increases, the main valve body 224 operates in the valve opening direction and changes in the direction in which the upstream pressure P1 decreases. On the contrary, when the upstream pressure P1 becomes smaller than the set differential pressure Pset, the bellows 251 is deformed in the direction of expanding the sealed space S1. As a result, the pilot valve body 244 operates in the valve closing direction, and the opening degree of the pilot valve 206 is reduced. As a result, since the intermediate pressure Pp decreases, the main valve body 224 operates in the valve closing direction and changes in the direction in which the upstream pressure P1 increases. In this way, the upstream pressure P1 is maintained at the set pressure Pset.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. The vehicle air conditioning apparatus according to the present embodiment is the same as the second embodiment except that the structure of the second control valve is slightly different. For this reason, about the component similar to 2nd Embodiment, the same code | symbol is attached | subjected etc., and the description is abbreviate | omitted suitably. FIG. 8 is a cross-sectional view illustrating a specific configuration of the second control valve according to the third embodiment.

  The second control valve 36 is configured by assembling the valve main body 301 and the solenoid 202, and is a pilot-operated control valve capable of controlling the flow of fluid so that the upstream pressure thereof becomes a set pressure corresponding to the supply current value. It is configured.

  The valve body 301 is different from the valve body 201 of the second embodiment in that a temperature sensing part is provided at the lower end of the main valve body 323. That is, a cylindrical partition wall 325 is provided so as to extend downward from the lower end portion of the main valve body 323, and a sub valve chamber 327 is formed by the internal space of the partition wall 325. A spring receiving member 331 is press-fitted into the lower end opening of the partition wall 325. A disc-shaped spring receiving member 346 is detachably disposed at the lower end of the pilot valve body 344, and a spring 356 (temperature sensitive spring) is provided between the bottom of the main valve body 323 and the spring receiving member 346. And a spring 358 is interposed between the spring receiving member 346 and the spring receiving member 331. A spring 359 that biases the pilot valve body 344 in the valve closing direction is interposed between the pilot valve body 344 and the spring receiving member 346.

  The spring 356 is made of a so-called shape memory alloy, and detects the temperature of the auxiliary valve chamber 327 (that is, the refrigerant temperature in the upstream passage), and the spring load changes. That is, the spring 356 changes so that the spring rigidity (spring load) increases as the upstream temperature increases, and the spring rigidity (spring load) decreases as the upstream temperature decreases. In addition, since such a shape memory alloy spring itself is well-known, the detailed description is abbreviate | omitted. In the modification, a temperature sensitive element such as a bimetal may be used as the spring 356 instead of the shape memory alloy spring.

  FIG. 9 is an explanatory diagram showing the operating state of the second control valve. FIG. 9 shows a control state in which the solenoid 202 is turned on. Note that FIG. 8 described above shows a state in which the solenoid 202 is turned off.

  As shown in FIG. 8, the second control valve 36 does not perform constant pressure control in a state where the solenoid 202 is turned off, and maintains the valve closed state. That is, since the solenoid force does not act on the second control valve 36, the pilot valve body 344 is biased in the valve closing direction by the spring 359, and the pilot valve 306 is closed. For this reason, the intermediate pressure Pp decreases, the main valve body 323 is urged in the valve closing direction, and the main valve 305 is also closed.

  On the other hand, as shown in FIG. 9, when the solenoid 202 is turned on, the second plunger 272 is sucked by the first plunger 271, so that the pilot valve body 344 is urged through the shaft 260 in the valve opening direction. The pilot valve 306 is opened. At this time, the pilot valve body 344 abuts against the spring receiving member 346 and operates integrally as shown. The second control valve 36 functions as a constant pressure valve that operates so that the upstream pressure P1 becomes a set pressure Pset corresponding to the supply current value. However, in this embodiment, the spring 356 senses the temperature of the refrigerant in the pressure chamber 216 (upstream temperature T1) and changes the spring load, so that the upstream pressure P1 becomes the set pressure Pset as a result. The pilot valve body 344 operates.

  That is, in the constant pressure control state in which the upstream pressure P1 becomes the set differential pressure Pset, the refrigerant in the pressure chamber 216 is in a saturated state, and when the upstream pressure P1 becomes larger than the set differential pressure Pset, the upstream temperature T1 is also increased. Rise to correspond to. As a result, the spring load (spring stiffness) of the spring 356 increases. For this reason, the urging force in the valve opening direction loaded on the pilot valve body 344 becomes relatively large. As a result, the pilot valve body 344 operates in the valve opening direction, and the opening degree of the pilot valve 306 is increased. As a result, since the intermediate pressure Pp increases, the main valve body 323 operates in the valve opening direction and changes in the direction in which the upstream pressure P1 decreases.

  On the other hand, when the upstream pressure P1 becomes smaller than the set differential pressure Pset, the upstream temperature T1 also decreases substantially proportionally. As a result, the spring load (spring stiffness) of the spring 356 is reduced. For this reason, the urging force in the valve closing direction loaded on the pilot valve body 344 becomes relatively large. As a result, the pilot valve body 344 operates in the valve closing direction, and the opening degree of the pilot valve 306 is reduced. As a result, since the intermediate pressure Pp decreases, the main valve body 323 operates in the valve closing direction and changes in the direction in which the upstream pressure P1 increases. In this way, the upstream pressure P1 is maintained at the set pressure Pset.

  In this embodiment, an example is shown in which the spring 356 is formed of a shape memory alloy as a temperature sensing element. However, in a modified example, the spring 358 is also configured of a temperature sensing element such as a shape memory alloy. Also good. Further, at least one of the springs 356 and 358 may be formed of a temperature sensitive element such as a shape memory alloy or bimetal so that the same function can be realized.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. The vehicle air conditioning apparatus according to the present embodiment is the same as that of the first embodiment except for the second control valve and its peripheral structure. For this reason, the description of the same components as those in the first embodiment is omitted. FIG. 10 is a cross-sectional view illustrating a specific configuration of the second control valve according to the fourth embodiment.

  The second control valve 46 is configured by assembling the valve main body 401 and the solenoid 402, and is a pilot operated control valve capable of controlling the flow of fluid so that the upstream side pressure becomes a set pressure corresponding to the supply current value. It is configured. The second control valve 46 has a function of combining the second control valve 6 of the first embodiment and the differential pressure orifice 20. That is, although the differential pressure orifice 460 is provided also in the present embodiment, the differential pressure orifice 460 is not provided in parallel with the second control valve 46 and is incorporated as a part of the second control valve 46. .

  The valve body 401 is configured by housing a main valve 405 and a pilot valve 406 in a body 403 coaxially. A bottomed stepped cylindrical partition member 410 is press-fitted into the center of the body 403. A sealing O-ring 412 is interposed between the body 403 and the partition member 410. The partition member 410 partitions the body 403 into a pressure chamber 116 and a pressure chamber 118. A main valve hole 120 is formed by an inner peripheral portion of an annular opening provided on the bottom surface of the partition member 410, and a main valve seat 122 is formed by a downstream opening edge thereof. The main valve body 424 is disposed so as to straddle the pressure chamber 116 and the pressure chamber 118. An annular valve member 425 made of an elastic body (rubber in this embodiment) is fitted to the lower end portion of the main valve body 424, and the valve member 425 is attached to and detached from the main valve seat 122 from the downstream side. The main valve 405 is opened and closed.

  On the other hand, a flange portion 426 is provided at the upper end portion of the main valve body 424 and is slidably supported on the inner peripheral surface of the body 403. A bottomed cylindrical partition member 430 is press-fitted into the upper end portion of the body 403. The lower end portion of the partition member 430 is press-fitted so as to be inserted into the upper end portion of the partition member 410. An O-ring 432 for sealing is interposed between the partition member 430 and the partition member 410. The main valve body 424 forms a back pressure chamber 132 with the partition member 430. In the center of the bottom of the partition member 430, a sub valve hole 140 that communicates the inside and the outside is provided, and a sub valve seat 142 is formed by an upstream opening edge thereof.

  The pilot valve body 444 is connected to the solenoid 402 and is electromagnetically driven. A sub valve chamber 438 is formed between the partition member 430 and the solenoid 402, and the pilot valve body 444 is attached to and detached from the sub valve seat 142 from the sub valve chamber 438 side. A communication hole 434 that communicates the inside and the outside is provided in a side portion of the partition member 430, and a communication groove 436 that is parallel to the axis is formed in a part of the outer peripheral surface of the partition member 410. The communication hole 434, the communication groove 436, and the inner peripheral surface of the body 403 form a communication path 440 that allows the inlet port 110 and the sub valve chamber 438 to communicate with each other. For this reason, the upstream pressure P <b> 1 is introduced into the sub valve chamber 438 and the solenoid 402.

  The main valve body 424 includes a first communication passage 451 and a second communication passage 452 arranged in parallel so that the back pressure chamber 132 and the pressure chamber 118 communicate with each other. The first communication path 451 and the second communication path 452 are each formed in parallel to the axis of the main valve body 424. The intermediate portion of the first communication passage 451 is reduced in diameter to form an orifice 454, and the refrigerant having the intermediate pressure Pp in the back pressure chamber 132 is reduced in pressure through the orifice 454 and derived as the downstream pressure P2. Is done. On the other hand, a differential pressure orifice 460 is provided in the second communication passage 452. By opening the differential pressure orifice 460, a predetermined flow rate of refrigerant is allowed even when the main valve 405 and the pilot valve 406 are closed.

  A valve seat forming member 462 is fitted to a connection portion between the second communication passage 452 and the back pressure chamber 132. The valve seat forming member 462 is made of an elastic material (rubber or the like), and a tapered valve seat 455 projects from the surface of the second communication passage 452 side. On the other hand, a communication hole 453 for communicating the inside and the outside is provided in the side portion of the main valve body 424. With such a configuration, the communication state between the back pressure chamber 132 and the pressure chamber 118 by the second communication passage 452 is virtually cut off, while the high pressure chamber 130 and the pressure chamber 118 communicate with each other via the second communication passage 452. is doing.

  The differential pressure orifice 460 functions as a differential pressure valve (check valve) that opens when the front-rear differential pressure exceeds a predetermined value, and also functions as an orifice that restricts the refrigerant flow rate when the valve is opened. That is, the differential pressure orifice 460 includes a stepped cylindrical valve body 463 in which a valve body portion 464 and an orifice portion 465 are integrally formed. Then, when the valve body 464 is attached to and detached from the valve seat 455, the second communication passage 452 is opened and closed.

  The orifice portion 465 has a guide portion 466 whose outer diameter is slightly expanded at the center in the longitudinal direction, and is supported by the main valve body 424 by the guide portion 466. The lower half portion of the orifice portion 465 extends downward through the lower end portion of the main valve body 424. An orifice passage 457 is provided so as to penetrate the orifice portion 465 along the axis of the valve body 463, and an upper end thereof is opened at the second communication passage 452 and a lower end thereof is opened at the pressure chamber 118. That is, the orifice passage 457 is formed so as to extend in the opening / closing direction of the valve body 463.

  A portion of the main valve body 424 constituting the second communication passage 452 has an inner diameter gradually reduced toward the lower side, and a lower end portion thereof serves as a locking portion 467 that locks the guide portion 466 from below. Yes. In addition, a guide hole 468 is provided in the upper portion of the locking portion 467, and supports the guide portion 466 so as to be slidable. A spring 469 that biases the valve body 463 in the valve closing direction is interposed between the valve body portion 464 and the main valve body 424.

  In the configuration as described above, the upstream pressure P1 is introduced into the auxiliary valve chamber 438 through the communication passage 440 and then becomes the intermediate pressure Pp in the back pressure chamber 132 through the pilot valve 406. The pressure is reduced through the valve 405 or the differential pressure orifice 460 to become the downstream pressure P2. The intermediate pressure Pp varies depending on whether the pilot valve 406 is open or closed.

  On the other hand, the solenoid 402 is attached so as to seal the upper end opening of the body 403. A seal ring 439 is interposed between the solenoid 402 and the body 403. The solenoid 402 has a cylindrical sleeve 470, a cylindrical core 472 (which functions as a “fixed iron core”) fixed to the upper half of the sleeve 470, and the core 472 is disposed in the sleeve 470 so as to face the axial direction. Plunger 471 (functioning as a “movable iron core”). A bobbin 473 is provided on the outer periphery of the sleeve 470, and an electromagnetic coil 474 is wound around the bobbin 473. A metal case 475 is provided so as to cover the electromagnetic coil 474 from the outside, and the internal structure of the case 475 is covered and protected from the outside by a body 476 formed of a resin mold. A collar 477 made of a magnetic member that forms a magnetic circuit together with the case 475 is embedded in the body 476. A part of the body 476 also functions as a connector portion that exposes one end of the terminal 279 connected to the electromagnetic coil 474.

  The plunger 471 has a cylindrical shape and is press-fitted so that the lower half of the shaft 447 is inserted. The upper half of the shaft 447 passes through the core 472 and the upper end thereof is connected to a power element 480 described later. A pilot valve body 444 is integrally formed at the lower end portion of the shaft 447. A spring 478 for biasing the pilot valve body 444 in the valve closing direction via the plunger 471 is interposed between the plunger 471 and the core 472.

  A power element 480 is attached to the upper end portion of the core 472 so as to seal the solenoid 402 from above. The power element 480 includes a hollow housing 482 and a diaphragm 484 (corresponding to a “pressure-sensitive member”) disposed so as to partition the housing 482 into a sealed space S1 and an open space S2. Yes. The housing 482 includes a cover-like upper housing 486 made of stainless steel and a stepped cylindrical lower housing 488, and the outer edge of the diaphragm 484 made of a thin metal plate of stainless steel or the like is abutted against these openings. It is assembled so as to sandwich it.

  The housing 482 is formed in a container shape by performing TIG welding or the like along the outer periphery of the joint portion with the diaphragm 484 sandwiched between the upper housing 486 and the lower housing 488. The sealed space S1 constitutes a temperature-sensitive room, and after filling the upper housing 486 with a refrigerant gas or the like for maintaining a reference pressure, a hole provided in the center of the upper surface is sealed with a ball-shaped sealing body 490. It is sealed by doing. In this embodiment, the same kind of refrigerant as that circulating in the refrigeration cycle is filled. The sealing body 490 is made of, for example, stainless steel.

  On the inner peripheral surface of the lower housing 488, a female screw portion that is screwed into a male screw portion formed at the distal end portion of the core 472 is formed. The lower half 488 is screwed into the upper end of the core 472 so that the power element 480 is fixed to the solenoid 402. The open space S <b> 2 constitutes a pressure sensing chamber, and a part of the refrigerant introduced into the sub valve chamber 438 is introduced through a gap in the solenoid 402.

  A bottomed cylindrical disk 492 is disposed in contact with the center of the lower surface of the diaphragm 484. The front end surface of the shaft 447 is exposed in the lower housing 488, and the disk 492 is provided between the diaphragm 484 and the shaft 447. When the open end of the disk 492 is locked to the bottom of the lower housing 488, the bottom dead center position (the amount of displacement in the valve closing direction) of the diaphragm 484 is regulated.

  FIG. 11 is an explanatory diagram showing the operating state of the second control valve. FIG. 11 shows a control state in which the solenoid 402 is turned on. Note that FIG. 10 already described represents a state in which the solenoid 402 is turned off.

  As shown in FIG. 10, when the solenoid 402 is off, the second control valve 46 does not perform constant pressure control and functions only as an expansion device. That is, since the solenoid force does not act, the pilot valve body 444 is urged in the valve closing direction by the spring 478, and the pilot valve 406 is closed. For this reason, since the high-pressure refrigerant is not introduced into the back pressure chamber 132, the intermediate pressure Pp decreases, the differential pressure (P1-Pp) increases, the main valve body 424 operates in the valve closing direction, and the main valve 405 also The valve is closed.

  At this time, in the differential pressure orifice 460, if the differential pressure across the valve body 463 (P1-P2) becomes larger than the set differential pressure (valve opening differential pressure), the valve body 463 resists the biasing force of the spring 469. Operates in the valve opening direction. As a result, the differential pressure orifice 460 is opened. As a result, the refrigerant introduced from the upstream side through the inlet port 110 is decompressed and expanded by passing through the orifice passage 457 and is led to the downstream side through the outlet port 112. At this time, the valve body 463 is separated from the valve seat 455 and a differential pressure is generated in the orifice passage 457.

  That is, in the state where the valve body 463 is seated on the valve seat 455, the downstream pressure P2 is applied to the inside of the orifice passage 457 over the entire length thereof, and at the same time the valve body 463 starts to be separated from the valve seat 455. The upstream pressure P1 acts on the upstream portion of the orifice passage 457. Since there is also a pressure loss in the orifice passage 457, a pressure gradient is formed from the upstream end to the downstream end, and fluid friction in the valve opening direction acts on the valve body 463 by the refrigerant passing through the inside of the orifice passage 457. become. As a result, the opening of the valve body 463 is promoted simultaneously with the start of the valve opening, and the valve body 463 can quickly settle down to the fully opened state as shown in the figure. As a result, the valve body 463 can be prevented from staying at a very small opening, and the function as the orifice (characteristics set in the orifice) can be satisfactorily exhibited.

  On the other hand, when the solenoid 402 is turned on, the second control valve 46 functions as a constant pressure valve that operates so that the upstream pressure P1 becomes a set pressure corresponding to the external temperature and the supply current value, and as an expansion device. Also works. That is, since a suction force acts between the plunger 471 and the core 472 by the solenoid force, the pilot valve body 444 is urged in the valve opening direction, and the pilot valve 406 is opened. As a result, the intermediate pressure Pp increases, so that the main valve body 424 is opened under the influence of the differential pressure (Pp−P2) between the intermediate pressure Pp and the downstream pressure P2.

  At this time, the refrigerant introduced from the upstream side via the inlet port 110 is decompressed and expanded via the opened main valve 405 and is led to the downstream side via the outlet port 112. Further, a part of the refrigerant introduced through the inlet port 110 is introduced into the back pressure chamber 132 through the pilot valve 406, is decompressed and expanded through the orifice 454, and is led out to the pressure chamber 118. It is led out downstream via 112.

  In this constant pressure control state, when the upstream pressure P1 becomes larger than the set differential pressure Pset, the diaphragm 484 is displaced in the direction of reducing the sealed space S1 (the opening direction of the pilot valve body 444). The degree is increased. As a result, since the intermediate pressure Pp increases, the main valve body 424 operates in the valve opening direction and changes in the direction in which the upstream pressure P1 decreases. Conversely, when the upstream pressure P1 becomes smaller than the set differential pressure Pset, the diaphragm 484 is displaced in a direction in which the sealed space S1 is expanded (the valve closing direction of the pilot valve body 444). As a result, since the intermediate pressure Pp decreases, the main valve body 424 operates in the valve closing direction and changes in the direction in which the upstream pressure P1 increases. As a result, the upstream pressure P1 is maintained at the set pressure Pset.

  The set pressure Pset varies depending on the external temperature. That is, as the external temperature increases, the pressure in the sealed space S1 increases so as to reach a saturation pressure corresponding to the refrigerant temperature, and thus the urging force in the direction of closing the pilot valve 406 increases. That is, even if the supply current value is the same, the higher the external temperature, the higher the set pressure of the upstream pressure P1.

  Further, when the switching valve 11 is opened with the second control valve 46 closed, the front-rear differential pressure (P1-P2) of the differential pressure orifice 460 approaches substantially zero. For this reason, all of the main valve 405, the pilot valve 406, and the differential pressure orifice 460 can be closed. As a result, the refrigerant bypasses without passing through the evaporator 7. Thereby, since the low-temperature and low-pressure refrigerant is temporarily not supplied to the evaporator 7, the temperature of the evaporator 7 is prevented from being extremely low and frozen.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments, and various modifications can be made within the scope of the technical idea of the present invention. Nor.

  In the above-described embodiment, an example in which the vehicle air conditioning apparatus according to the present invention is applied to an electric vehicle has been described. However, the present invention can be provided to an automobile equipped with an internal combustion engine or a hybrid automobile equipped with an internal combustion engine and an electric motor. Needless to say. In the above-described embodiment, an example in which an electric compressor is employed as the compressor 2 has been described. However, a variable capacity compressor that performs variable capacity using the rotation of the engine may be employed.

  DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner, 2 Compressor, 3 Indoor condenser, 4 First control valve, 5 Outdoor heat exchanger, 6 Second control valve, 7 Evaporator, 8 Accumulator, 9 Bypass passage, 11 Switching valve, 13 Bypass Passage, 18 orifice, 20 differential pressure orifice, 26, 36, 46 second control valve, 100 control unit, 101 valve body, 102 solenoid, 103 body, 105 main valve, 106 pilot valve, 110 inlet port, 112 outlet port, 120 main valve hole, 122 main valve seat, 124 main valve body, 130 high pressure chamber, 132 back pressure chamber, 138 leak passage, 140 sub valve hole, 142 sub valve seat, 144 pilot valve body, 148 diaphragm, 151 reaction force transmission Member, 171 first plunger, 172 second plunger 201 Valve body, 202 Solenoid, 203 Body, 205 Main valve, 206 Pilot valve, 224 Main valve body, 230 Low pressure chamber, 240 Sub valve hole, 242 Sub valve seat, 244 Pilot valve body, 250 Power element, 251 Bellows, 252 Case, 262 Pilot passage, 271 First plunger, 272 Second plunger, 301 Valve body, 305 Main valve, 306 Pilot valve, 322 Body, 323 Main valve body, 333 Valve hole, 335 Valve seat, 336 High pressure chamber, 338 Intermediate Pressure chamber, 340 Low pressure chamber, 342 Valve member, 344 Pilot valve body, 363 Valve body, 365 Orifice part, 366 Orifice passage, 401 Valve body, 402 Solenoid, 403 body, 405 Main valve, 4 6 Pilot valve, 424 Main valve body, 425 Valve member, 444 Pilot valve body, 455 Valve seat, 457 Orifice passage, 460 Differential pressure orifice, 462 Valve seat forming member, 463 Valve body, 464 Valve body part, 465 Orifice part, 471 plunger, 472 core, 480 power element, 484 diaphragm.

Claims (4)

In a pilot operated control valve capable of controlling the flow of refrigerant from the upstream side to the downstream side,
A main passage directly connecting the upstream passage and the downstream passage has a main valve body that opens and closes the main valve hole, and the main valve body includes the upstream passage, the downstream passage, and a back pressure chamber. A main valve provided to partition
An electromagnetically driven pilot valve body capable of adjusting an opening degree of a sub-passage connecting the upstream-side passage and the downstream-side passage via the back pressure chamber by contacting and separating from the sub-valve hole; However, when the main valve is opened, a pilot valve that operates to bring the pressure on the upstream side of the main valve closer to a set pressure according to a supply current value;
A control valve comprising: A temperature sensing unit that senses a temperature upstream of the main valve hole and changes a load in an opening and closing direction of the pilot valve that is loaded on the pilot valve body according to the temperature;
2. The control valve according to claim 1, wherein the pilot valve operates such that a temperature on the upstream side of the main valve approaches a temperature corresponding to a supply current value when the main valve is opened. A temperature sensing unit that senses an external temperature and changes a load in an opening and closing direction of the pilot valve loaded on the pilot valve body according to the temperature;
The control valve according to claim 1, wherein the temperature sensing unit changes the set pressure in accordance with the external temperature. A compressor that compresses and discharges the refrigerant;
An outdoor heat exchanger that is arranged outside the passenger compartment and functions as an outdoor condenser that dissipates the refrigerant during cooling operation, while functioning as an outdoor evaporator that evaporates the refrigerant during heating operation;
An indoor evaporator disposed in the passenger compartment to evaporate the refrigerant;
When the indoor evaporator functions and the outdoor heat exchanger functions as an outdoor evaporator, it is provided at a position on the downstream side of the outdoor heat exchanger, and controls the flow of refrigerant from the upstream side to the downstream side. An electric control valve;
A control unit that controls the current supplied to the control valve to adjust the pressure on the upstream side of the control valve;
A vehicle air conditioning system comprising:
The control valve is
A main passage directly connecting the upstream passage and the downstream passage has a main valve body that opens and closes the main valve hole, and the main valve body includes the upstream passage, the downstream passage, and a back pressure chamber. A main valve provided to partition
An electromagnetically driven pilot valve body capable of adjusting an opening degree of a sub-passage connecting the upstream-side passage and the downstream-side passage via the back pressure chamber by contacting and separating from the sub-valve hole; However, when the main valve is opened, a pilot valve that operates to bring the pressure on the upstream side of the main valve closer to a set pressure according to a supply current value;
A vehicle air-conditioning / heating device comprising:

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