JP2015045453A - Integrated valve and drive system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integrated valve which can simplify a cycle constitution of a heat pump cycle while suppressing that a liquid phase refrigerant flows into a compressor via an intermediate-pressure refrigerant passage, and a drive system thereof.SOLUTION: A fixed throttle 17, a liquid phase side valve body 162, an air phase side valve body 161, and the like are accommodated in a body 140 and integrated, and the valve bodies 161, 162 are displaced by single drive means 18. The drive means 18 is switchable into a first mode in which an air phase refrigerant passage 141f is fully closed and a liquid phase refrigerant passage 142c is fully opened, a second mode in which the liquid phase refrigerant passage 142c is fully closed and the air liquid refrigerant passage 141f is fully opened, and a third mode in which the liquid phase refrigerant passage 142c is fully closed and the air phase refrigerant passage 141f is fully closed or slightly opened. Then, when a liquid flow-in condition that a liquid phase refrigerant flows into an intermediate-pressure refrigerant passage 15 is established, a drive system switches an operation mode of an integrated valve 14 to the third mode.

Description

  The present invention relates to an integrated valve applied to a heat pump cycle that can be switched to a gas injection cycle, and a drive system for the integrated valve, and is suitable for a vehicle air conditioner.

  Conventionally, high-temperature and high-pressure refrigerant discharged from a compressor of a heat pump cycle (vapor compression type refrigeration cycle) is used as an air conditioner applied to a vehicle such as an electric vehicle in which it is difficult to secure a heat source for heating the passenger compartment. Some heat sources heat the passenger compartment.

  As this type of heat pump cycle, the refrigerant is decompressed in two stages between the radiator and the evaporator, and a gas injection cycle in which a part of the intermediate pressure refrigerant (gas phase refrigerant) is merged with the refrigerant in the compression process in the compressor ( An economizer refrigeration cycle is known.

  For example, Patent Document 1 discloses a heat pump cycle that switches from a normal cycle (one-stage compression cycle) to a gas injection cycle (two-stage compression cycle) during heating operation in order to improve the coefficient of performance (COP) of the cycle during heating operation. It is disclosed.

  Here, the heat pump cycle that can be switched to the gas injection cycle requires a gas-liquid separation means that separates the gas-liquid refrigerant flowing out of the radiator, a switching means that switches the refrigerant circuit, and the like, compared to a normal one-stage compression cycle. There is a problem that the cycle configuration becomes complicated.

  Therefore, in Patent Document 1, in the heat pump cycle, the gas-liquid separation means necessary for realizing the gas injection cycle, the switching means for switching the refrigerant circuit, and the like are integrated as an integrated valve, thereby simplifying the cycle configuration. I am trying.

JP 2013-92354 A

  By the way, when the present inventors applied the integrated valve described in Patent Document 1 to a heat pump cycle, when the heat pump cycle is switched to the gas injection cycle, the liquid phase refrigerant is supplied to the compressor via the intermediate pressure refrigerant passage. It turns out that it may flow in. When the inflow of the liquid refrigerant into the compressor occurs, the lubricating oil existing in the compressor flows out, which causes a problem such as lack of lubricating oil inside the compressor, which is not preferable.

  When the present inventors investigated the cause of the above-mentioned trouble, the cause of the trouble became clear. Hereinafter, this point will be described based on the components of the integrated valve.

  FIG. 23 is a schematic diagram showing a configuration (hereinafter referred to as a study example) in which the integrated valve disclosed in Patent Document 1 is applied to a heat pump cycle that can be switched between a gas injection cycle and a normal cycle. In addition, the solid line arrow shown in FIG. 23 shows the flow of the refrigerant at the time of switching to the gas injection cycle during the heating operation, and the broken line arrow shown in FIG. 23 is the one at the time of switching to the normal cycle (one-stage compression cycle) during the heating operation. The flow of the refrigerant is shown.

  First, each component of the study example will be briefly described. The heat pump cycle 100 of the examination example includes an intermediate pressure port 101c that compresses the refrigerant sucked from the suction port 101a and discharges it from the discharge port 101b, and flows the intermediate pressure refrigerant in the cycle into the refrigerant in the compression process. A two-stage compression type compressor 101 is provided.

  From the upstream side to the discharge port 101b side of the compressor 101, the radiator 102, the decompression means 103, the integrated valve 104, the outdoor heat exchanger 105 functioning as an evaporator, and the gas-liquid refrigerant flowing out of the outdoor heat exchanger 105 The accumulator 106 etc. which isolate | separate are connected.

  The integrated valve 104 selectively opens and closes the gas-phase refrigerant passage 104c and the liquid-phase refrigerant passage 104d inside the body 104a in which the gas-liquid separation space 104b for separating the gas-liquid refrigerant flowing out from the decompression means 103 is formed. The valve body 104e and the fixed throttle 104f are accommodated. The valve body 104e is connected to the electric actuator 104h via the rod 104g. The gas-phase refrigerant passage 104c communicates with the intermediate pressure port 101c of the compressor 101 via the intermediate pressure refrigerant passage 107.

  The above is description of the heat pump cycle 100 which concerns on an examination example, and, below, the cause of the above-mentioned malfunction is demonstrated.

  During the normal cycle, the valve body 104e of the integrated valve 104 is set to a position where the gas-phase refrigerant passage 104c is closed and the liquid-phase refrigerant passage 104d is opened by the electric actuator 104h. In this case, since the liquid-phase refrigerant passage 104d is open, all of the refrigerant that has flowed out of the gas-liquid separation space 104b flows into the outdoor heat exchanger 105 that functions as an evaporator via the liquid-phase refrigerant passage 104d.

  When switching from this state to the gas injection cycle, in the integrated valve 104, the position of the valve body 104e is set to a position where the liquid-phase refrigerant passage 104d is closed and the gas-phase refrigerant passage 104c is opened by the electric actuator 104h.

  In this case, all of the liquid-phase refrigerant separated in the gas-liquid separation space 104b flows into the fixed throttle 104f by closing the liquid-phase refrigerant passage 104d. At this time, the flow rate of the refrigerant passing through the fixed throttle 104f is rapidly increased, so that the heat pump cycle 10 is balanced so that the pressure of the low-pressure refrigerant in the cycle is rapidly decreased.

  Then, due to a rapid pressure drop of the low-pressure refrigerant in the cycle, forming (boiling, bumping) occurs in the accumulator 106 on the downstream side of the fixed throttle 104 f, and surplus refrigerant stored in the accumulator 106 is sucked into the suction port 101 a of the compressor 101. Inhaled. This increases the flow rate of the refrigerant circulating in the cycle.

  Here, the time until the flow rate of the refrigerant circulating in the cycle increases is shorter than the time until the pressure difference before and after the fixed throttle 104f expands to a level at which all the liquid refrigerant flows through the fixed throttle 104f.

  For this reason, in the fixed throttle 104f, when the flow rate of the refrigerant circulating in the cycle increases, the liquid-phase refrigerant cannot completely flow through the fixed throttle 104f, and the liquid-phase refrigerant that cannot flow through the fixed throttle 104f is a gas-phase refrigerant. At the same time, the refrigerant flows out to the intermediate pressure refrigerant passage 107 via the gas-phase refrigerant passage 104c. As a result, the liquid-phase refrigerant flows into the compressor 101 through the intermediate pressure refrigerant passage 107.

  Such a malfunction occurs not only when the refrigerant circuit of the heat pump cycle 100 is switched, but also occurs when the load state of the compressor 101 increases abruptly in the gas injection cycle, for example. That is, in the transition period when the load state of the compressor 101 shifts to a high load state, the flow rate of the refrigerant passing through the fixed throttle 104f increases rapidly, and the refrigerant pressure after passing through the fixed throttle 104f rapidly decreases. So that the cycle is balanced. This is because, similarly to the switching of the refrigerant circuit in the heat pump cycle 100, forming (boiling, bumping) occurs in the accumulator 106, and the flow rate of the refrigerant circulating in the cycle increases.

  In view of the above, the present invention provides an integrated valve capable of simplifying the cycle configuration of the heat pump cycle while suppressing the liquid phase refrigerant from flowing into the compressor through the intermediate pressure refrigerant passage, and An object is to provide such a drive system.

  The present invention is directed to an integrated valve applied to a heat pump cycle 10 that can be switched to a gas injection cycle, and a drive system thereof.

In order to achieve the above object, in the invention described in claim 1,
Refrigerant inlet (141a) through which the refrigerant discharged from the compressor (11) of the heat pump cycle flows, gas-liquid separation space (141b) for separating the gas and liquid of the refrigerant flowing in from the refrigerant inlet, and intermediate pressure refrigerant passage (15 ) Through which the gas-phase refrigerant separated in the gas-liquid separation space flows out to the intermediate suction port (11c) side of the compressor, and the liquid separated in the gas-liquid separation space A body (140) formed with a liquid-phase side outlet (142b) through which the phase refrigerant flows out;
A gas-phase-side valve element (161) that changes the passage opening degree of the gas-phase refrigerant passage (141f) from the gas-liquid separation space to the gas-phase-side outlet,
A liquid-phase side valve element (162) for changing the passage opening degree of the liquid-phase refrigerant passage (142c) from the gas-liquid separation space to the liquid-phase side outlet;
Drive means (18) for displacing both the gas phase side valve body and the liquid phase side valve body;
A fixed throttle (17) for depressurizing the refrigerant flowing out to the liquid-phase side outlet when the liquid-phase side valve element closes the liquid-phase refrigerant passage,
The drive means is
When displacing the gas phase side valve element to the fully closed position that closes the gas phase refrigerant path, the liquid phase side valve element is configured to be displaced to the fully open position where the passage opening degree of the liquid phase refrigerant path is in a fully open state,
When the liquid phase side valve element is displaced to the fully closed position for closing the liquid phase refrigerant passage, the opening degree of the gas phase refrigerant passage is fully opened, and the opening degree of the gas phase refrigerant passage is from the fully open state. It is characterized in that it can be displaced to a smaller position.

  According to this, the fixed throttle, the liquid phase side valve element, and the gas phase side valve element are accommodated and integrated in the body, and the liquid phase refrigerant side valve element and the gas phase side valve element are integrated into a single drive means. The heat pump cycle that can be switched to the gas injection cycle can be realized with a simple cycle configuration.

  Specifically, all the refrigerant that has flowed out of the gas-liquid separation space flows out of the liquid-phase side outlet by setting the passage opening of the liquid-phase refrigerant passage to a fully open state with the gas-phase refrigerant passage closed. The refrigerant circuit can be switched to.

  In addition, by setting the opening degree of the gas-phase refrigerant passage to a fully open state with the liquid-phase refrigerant passage closed, the liquid-phase refrigerant separated in the gas-liquid separation space is decompressed with a fixed throttle, It is possible to switch to a refrigerant circuit that causes the gas-phase refrigerant flowing out from the separation space to flow out to the intermediate suction port side of the compressor.

  In particular, in the first aspect of the present invention, the opening degree of the gas-phase refrigerant path can be set to a smaller opening degree than that in the fully opened state with the liquid phase refrigerant path closed.

  According to this, when the liquid-phase refrigerant cannot flow through the fixed throttle, the gas-phase refrigerant passage is compressed through the intermediate pressure refrigerant passage by setting the passage opening of the gas-phase refrigerant passage to a passage opening smaller than the fully opened state. It is possible to suppress the liquid refrigerant from flowing into the intermediate suction port side of the machine. As a result, it is possible to suppress the occurrence of a malfunction of the compressor due to the inflow of the liquid phase refrigerant.

  Therefore, according to the present invention, it is possible to suppress the liquid phase refrigerant from flowing into the compressor through the intermediate pressure refrigerant passage while simplifying the cycle configuration of the heat pump cycle that can be switched to the gas injection cycle. Can do.

  The “passage opening” indicates the degree of opening of the refrigerant passage. The larger the passage opening, the closer the refrigerant passage is to the fully open state, and the smaller the passage opening, the more the refrigerant passages are fully closed. It will approach. In addition, the “position where the opening degree of the gas-phase refrigerant passage is smaller than the fully opened state” includes not only the position where the gas-phase refrigerant passage is opened but also the position where the gas-phase refrigerant passage is closed ( (Fully closed position) is also included.

In the invention according to claim 5,
Integrated valve (14) according to any one of claims 1 to 4,
A first mode in which the drive means is controlled to fully open the passage opening of the liquid phase refrigerant passage with the gas phase refrigerant passage closed, and the passage opening of the gas phase refrigerant passage with the liquid phase refrigerant passage closed. Drive control means (40a) for switching to a second mode in which the gas-phase refrigerant passage is closed and a third mode in which the passage opening of the gas-phase refrigerant passage is smaller than that in the full-open state with the liquid-phase refrigerant passage closed. With
The drive control means is characterized by controlling the drive means to switch to the third mode when a liquid inflow condition in which the liquid refrigerant flows into the intermediate pressure refrigerant passage is satisfied.

  In this way, the passage opening of the gas-phase refrigerant passage is made smaller than that in the fully open state with the liquid-phase refrigerant passage closed, under the condition that the liquid-phase refrigerant flows into the intermediate suction port of the compressor. By switching, the inflow of the liquid phase refrigerant into the gas phase refrigerant passage can be effectively suppressed. As a result, it is possible to effectively suppress the liquid refrigerant from flowing into the compressor via the intermediate pressure refrigerant passage.

  In addition, the code | symbol in the parenthesis of each means described in this column and the claim shows an example of a correspondence relationship with the specific means described in the embodiment described later.

It is a whole block diagram which shows the refrigerant circuit at the time of the cooling operation mode of the heat pump cycle which concerns on embodiment, and the dehumidification heating operation mode. It is a whole lineblock diagram showing the refrigerant circuit at the time of the 1st heating mode of the heat pump cycle concerning an embodiment. It is a whole block diagram which shows the refrigerant circuit at the time of the 2nd heating mode of the heat pump cycle which concerns on embodiment. It is an up-down direction sectional view showing the operation state at the time of the 1st mode of the integrated valve concerning an embodiment. It is an up-down direction sectional view showing the operation state at the time of the 2nd mode of the integrated valve concerning an embodiment. It is an up-down direction sectional view showing the operation state at the time of the 3rd mode of the integrated valve concerning an embodiment. It is principal part sectional drawing which shows the principal part of the integrated valve which concerns on embodiment. It is principal part sectional drawing for demonstrating the shutter function of the vapor phase side valve body of the integrated valve which concerns on embodiment. It is principal part sectional drawing for demonstrating the suppression effect of the refrigerant | coolant leakage of the integrated valve which concerns on embodiment. It is a graph which shows the correspondence of the operation mode of an integrated valve, and the position of a gas phase side valve body and a liquid phase side valve body. It is a flowchart which shows the flow of the switching control process of the operation mode in a heat pump cycle. It is a Mollier diagram for demonstrating the air_conditionaing | cooling operation mode of the heat pump cycle which concerns on embodiment. It is a Mollier diagram for demonstrating the 1st heating mode of the heat pump cycle which concerns on embodiment. It is explanatory drawing for demonstrating the relationship between the flow volume of the refrigerant | coolant which flows in into a fixed throttle, and the pressure difference before and behind a fixed throttle. It is a timing chart which shows the change of the throttle opening of the high stage side expansion valve at the time of switching to the 1st heating mode, the refrigerant pressure in a cycle, and the number of rotations of a compressor. It is a timing chart. It is a timing chart which shows the change of the throttle opening of the high stage side expansion valve, the refrigerant | coolant pressure in a cycle, and the rotation speed of a compressor at the time of the 1st heating mode when the load state of a compressor turns into a high load state. It is a flowchart which shows the flow of the mode switching control process of the integrated valve at the time of 1st heating mode. It is a Mollier diagram for demonstrating the 2nd heating mode of the heat pump cycle which concerns on embodiment. It is a Mollier diagram for demonstrating the 1st dehumidification heating mode of the heat pump cycle which concerns on embodiment. It is a Mollier diagram for demonstrating the 2nd dehumidification heating mode of the heat pump cycle which concerns on embodiment. It is a Mollier diagram for demonstrating the 3rd dehumidification heating mode of the heat pump cycle which concerns on embodiment. It is a Mollier diagram for demonstrating the 4th dehumidification heating mode of the heat pump cycle which concerns on embodiment. It is a typical block diagram of the heat pump cycle which concerns on the examination example.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, the heat pump cycle 10 including the integrated valve 14 of the present invention and the drive system for the integrated valve 14 is applied to an air conditioner 1 for an electric vehicle that obtains a driving force for vehicle traveling from an electric motor for traveling. Yes. In the vehicle air conditioner 1, the heat pump cycle 10 functions to adjust the temperature of the indoor blown air by using the indoor blown air blown into the vehicle interior, which is the air conditioning target space, as the heat exchange target fluid.

  The heat pump cycle 10 of the present embodiment includes a refrigerant circuit (FIG. 1) in a cooling operation mode for cooling the passenger compartment and heating while dehumidifying the passenger compartment (FIG. 1), and a refrigerant circuit in a heating operation mode for heating the passenger compartment. (FIGS. 2 and 3) can be switched.

  In the heat pump cycle 10 of the present embodiment, the refrigerant circuit in the first heating mode executed when the outside air temperature is extremely low (for example, 0 ° C. or less) as the heating operation mode as will be described later (FIG. 2). The refrigerant circuit (FIG. 3) in the second heating mode in which normal heating is performed can be switched.

  In the present embodiment, the refrigerant circuit in the first heating mode shown in FIG. 2 constitutes a gas injection cycle (two-stage compression cycle), and the refrigerant circuit in the cooling operation mode and the dehumidifying heating mode and the refrigerant circuit in the second heating mode are normal. Cycle (single-stage compression cycle). In the present embodiment, the first heating mode corresponds to an “injection mode” in which the gas-phase refrigerant flows into the intermediate pressure port 11c side of the compressor 11 via an intermediate pressure refrigerant passage 15 described later.

  Therefore, the heat pump cycle 10 of the present embodiment is configured as a cycle that can be switched to a gas injection cycle (two-stage compression cycle) and a normal cycle (one-stage compression cycle) other than the gas injection cycle. In addition, the whole block diagram of FIG. 1 has shown the refrigerant circuit at the time of switching to air_conditionaing | cooling operation mode and dehumidification heating operation mode, and the refrigerant circuit at the time of the whole block diagram of FIG. 2, FIG. 3 switching to heating operation mode Is shown. Moreover, in FIGS. 1-3, the flow of the refrigerant | coolant in each operation mode is shown by the solid line arrow.

The heat pump cycle 10 employs an HFC-based refrigerant (for example, R134a) as the refrigerant, and constitutes a vapor compression subcritical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the refrigerant critical pressure. Of course, HFO-based refrigerant (e.g., R1234yf) may be employed and carbon dioxide CO ₂ and the like. The refrigerant is mixed with refrigerating machine oil (lubricating oil) for lubricating the compressor 11, and a part of the refrigerating machine oil circulates in the cycle together with the refrigerant.

  Among the components of the heat pump cycle 10, the compressor 11 is disposed in the hood of the vehicle, and sucks, compresses and discharges the refrigerant in the heat pump cycle 10. The compressor 11 is configured by an electric compressor configured to house a compression mechanism that compresses a refrigerant in a compression chamber (not shown) and an electric motor that rotationally drives the compression mechanism inside a housing that forms an outer shell. .

  The housing of the compressor 11 includes a suction port 11a that sucks low-pressure refrigerant into the compression chamber, a discharge port 11b that discharges high-pressure refrigerant from the compression chamber, guides intermediate-pressure refrigerant in the cycle to the compression chamber, and serves as a refrigerant in the compression process. An intermediate pressure port (intermediate suction port) 11c to be joined is provided. Although not shown, the compressor 11 is provided with an oil sump for supplying lubricating oil to the sliding portion of the compression mechanism.

  As the compression mechanism of the compressor 11, a scroll type compression mechanism can be adopted. The compression mechanism of the compressor 11 is not limited to the scroll type compression mechanism, and various types such as a vane type compression mechanism and a rolling piston type compression mechanism can be adopted.

  Further, the compressor 11 allows the refrigerant to flow into the compression chamber from the intermediate pressure refrigerant passage 15 (described later) connected to the intermediate pressure port 11c, and the refrigerant flows from the compression chamber into the intermediate pressure refrigerant passage 15 side. A check valve (not shown) for prohibiting is incorporated. Thus, when the refrigerant pressure in the compression chamber becomes higher than the refrigerant pressure in the intermediate pressure refrigerant passage 15 (refrigerant pressure on the intermediate pressure port 11c side), the intermediate pressure refrigerant passage 15 passes from the compression chamber through the intermediate pressure port 11c. It is possible to prevent the refrigerant from flowing back to the side.

  The operation (rotation speed) of the electric motor is controlled by a control signal output from the air conditioning control device 40 described later, and either an AC motor or a DC motor may be adopted. And the refrigerant | coolant discharge capability of the compressor 11 is changed by this rotation speed control. Therefore, in this embodiment, the electric motor constitutes the discharge capacity changing means of the compressor 11.

  The refrigerant inlet side of the indoor condenser 12 is connected to the discharge port 11 b of the compressor 11. The indoor condenser 12 is disposed in an air conditioning case 31 of an indoor air conditioning unit 30 to be described later, radiates high-pressure refrigerant discharged from the compressor 11, and heats indoor blown air that has passed through an indoor evaporator 23 to be described later. It is a radiator.

  The refrigerant outlet side of the indoor condenser 12 is connected to the inlet side of the high stage expansion valve 13 that can depressurize the high-pressure refrigerant flowing out of the indoor condenser 12 until it becomes an intermediate-pressure refrigerant. The high-stage expansion valve 13 is an electric type that includes a valve body that can change the throttle opening degree and an electric actuator that includes a stepping motor that changes the throttle opening degree of the valve body. This is a variable aperture mechanism.

  The high stage side expansion valve 13 is configured to be able to be set to a throttling state that exhibits a pressure reducing action and a fully open state that does not exhibit a pressure reducing action. In other words, the high stage side expansion valve 13 of the present embodiment is configured to be able to be set to a throttled state in which the refrigerant flowing out from the indoor condenser 12 is decompressed at least until it becomes an intermediate pressure refrigerant.

  Specifically, the high-stage expansion valve 13 is configured to change the throttle opening in a range where the throttle passage area has an equivalent diameter of φ0.5 to φ3 mm when the refrigerant is decompressed. Further, when the throttle opening is fully opened, the high stage side expansion valve 13 can secure a throttle passage area of an equivalent diameter of about 10 mm so as not to exert the refrigerant decompression action. The operation of the high stage side expansion valve 13 is controlled by a control signal output from the air conditioning control device 40.

  The refrigerant inlet side of the integrated valve 14 is connected to the outlet side of the high stage side expansion valve 13. This integrated valve 14 is an integral part of the components required to make the heat pump cycle 10 function as a gas injection cycle, and serves as refrigerant circuit switching means for switching the refrigerant circuit of the refrigerant circulating in the cycle. Fulfills the function.

  Specifically, the integrated valve 14 includes a gas-liquid separation unit (gas-liquid separation space 141b) that separates the gas-liquid refrigerant, a fixed throttle 17 that decompresses the liquid-phase refrigerant separated by the gas-liquid separation unit, and a gas-liquid separation. The valve means 16 etc. which open and close the refrigerant path through which the refrigerant | coolant which flowed out from the means distribute | circulates are comprised integrally.

  The detailed configuration of the integrated valve 14 will be described with reference to FIGS. 4 to 6 are schematic vertical sectional views of the integrated valve 14. FIG. 4 shows a first mode in which the liquid-phase refrigerant passage 142c is fully opened with the gas-phase refrigerant passage 141f closed. FIG. 5 shows a cross-sectional view in the second mode in which the gas-phase refrigerant passage 141f is fully opened with the liquid-phase refrigerant passage 142c closed, and FIG. 6 shows the state with the liquid-phase refrigerant passage 142c closed. A sectional view in the third mode in which the gas-phase refrigerant passage 141f is fully closed or slightly opened is shown. In addition, the arrow which shows up and down in FIGS. 4-6 has shown the direction in the state which mounted the integrated valve 14 in the vehicle air conditioner 1. FIG.

  The integrated valve 14 has a body 140 that forms an outer shell thereof and accommodates the fixed throttle 17 and the valve means 16 therein. The body 140 is configured by a substantially rectangular tube-shaped metal block body (for example, aluminum) whose axial direction extends in the vertical direction. The body 140 according to the present embodiment includes an upper block 141 disposed on the upper side and a lower block 142 attached and fixed to the lower side of the upper block 141.

  In the upper block 141, a gas-liquid separation space 141b for separating the gas-liquid refrigerant flowing out from the high stage side expansion valve 13 is formed. The gas-liquid separation space 141b is formed in a columnar shape whose axial direction extends in the vertical direction.

  More specifically, the gas-liquid separation space 141b of the present embodiment has an internal volume that exhibits the maximum capacity of the cycle from the enclosed refrigerant volume when the amount of refrigerant enclosed in the cycle is converted to the liquid phase. It is set smaller than the surplus refrigerant volume obtained by subtracting the necessary refrigerant volume when the necessary refrigerant amount is converted into the liquid phase. That is, the internal volume of the gas-liquid separation space 141b of the present embodiment is such that the surplus refrigerant cannot be substantially accumulated even when the load fluctuation occurs in the cycle and the refrigerant circulation flow rate circulating in the cycle fluctuates. It has become. According to this, size reduction of the physique as the integrated valve 14 whole can be achieved.

  Further, the upper block 141 is formed with a refrigerant inlet 141a for allowing the refrigerant from the high stage side expansion valve 13 to flow into the outer wall surface thereof. The refrigerant inflow port 141a communicates with the gas-liquid separation space 141b through a refrigerant introduction hole 141g opened in the inner wall surface of the gas-liquid separation space 141b.

  Here, the refrigerant introduction passage 141h constituting the refrigerant passage from the refrigerant inlet 141a to the refrigerant introduction hole 141g is tangential to the inner wall surface of the gas-liquid separation space 141b when viewed from the axial direction of the gas-liquid separation space 141b. It is formed to extend.

  Thereby, the refrigerant that has flowed into the gas-liquid separation space 141b from the refrigerant inlet 141a swirls along the inner wall surface of the gas-liquid separation space 141b. And the gas-liquid of the refrigerant | coolant which flowed into the gas-liquid separation space 141b is isolate | separated by the centrifugal force which arises by this turning flow, and the isolate | separated liquid phase refrigerant | coolant falls to the downward side of the gas-liquid separation space 141b by gravity. In addition, the gas-liquid separation space 141b of the present embodiment constitutes a centrifugal-type gas-liquid separation means.

  Further, the upper block 141 is provided with a round tubular pipe portion 141c that is disposed inside the gas-liquid separation space 141b and coaxially with the gas-liquid separation space 141b. The refrigerant that has flowed into the gas-liquid separation space 141b swirls around the pipe portion 141c.

  The pipe portion 141c extends such that the lowermost lower end portion is positioned inside the gas-liquid separation space 141b, and the gas phase refrigerant separated in the gas-liquid separation space 141b is supplied to the lower end portion. An annular (doughnut-shaped) gas-phase-side inflow portion 141d for inflow is formed. Note that the gas-phase-side inflow portion 141d protrudes downward, and functions as a gas-phase-side valve seat portion to which a gas-phase-side valve body 161 described later contacts and separates.

  On the upper side of the gas-liquid separation space 141b of the upper block 141, a gas phase side outlet 141e formed on the outer wall surface of the upper block 141 and a through hole communicating with the internal space of the pipe portion 141c are formed. This through hole constitutes, together with the internal space of the pipe portion 141c, a gas phase refrigerant passage 141f through which the gas phase refrigerant separated in the gas-liquid separation space 141b flows out from the gas phase side outlet 141e. Although not shown, an intermediate pressure refrigerant passage 15 that guides the gas phase refrigerant to the intermediate pressure port 11c of the compressor 11 is connected to the gas phase side outlet 141e.

  Subsequently, when the lower block 142 is integrated with the upper block 141, an annular shape (in which the liquid-phase refrigerant separated in the gas-liquid separation space 141b flows into a position facing the gas-phase inflow portion 141d) ( A liquid phase side inflow portion 142a having a donut shape is formed. In addition, the liquid phase side inflow portion 142a is formed integrally with the lower block 142 so as to protrude upward, and serves as a liquid phase side valve seat portion to which a liquid phase side valve body 162 to be described later contacts and separates. Plays a function.

  The lower block 142 has a liquid phase side outlet 142b formed on the outer wall surface of the lower block 142, and a through hole communicating with the liquid phase side inflow portion 142a. This through-hole constitutes a liquid-phase refrigerant passage 142c through which the liquid-phase refrigerant separated in the gas-liquid separation space 141b flows out from the liquid-phase side outlet 142b.

  In addition, when the liquid phase side valve body 162 described later closes the liquid phase refrigerant passage 142c, the lower block 142 depressurizes the refrigerant flowing in from the gas-liquid separation space 141b and flows out to the liquid phase side outlet 142b side. A fixed diaphragm 17 is formed.

  Here, the pressure loss that occurs when the refrigerant passes through the liquid-phase refrigerant passage 142 c with the liquid-phase refrigerant passage 142 c open is extremely small compared to the pressure loss that occurs when the refrigerant passes through the fixed throttle 17.

  For this reason, in a state where the liquid phase refrigerant passage 142c is opened, the refrigerant flowing in from the liquid phase side inflow portion 142a is not decompressed by the fixed throttle 17, and is discharged through the liquid phase refrigerant passage 142. It flows out from 142b.

  On the other hand, in a state where the liquid-phase refrigerant passage 142c is closed, the refrigerant flowing from the liquid-phase side inflow portion 142a is depressurized by the fixed throttle 17, and the refrigerant depressurized by the fixed throttle 17 is discharged from the liquid-phase side outlet 142b. leak.

  Here, as the fixed throttle 17, a nozzle, an orifice, or the like having a fixed throttle opening can be employed. In fixed throttles such as nozzles and orifices, the throttle passage area suddenly shrinks or expands rapidly, so that the flow rate of refrigerant passing through the fixed throttle as the pressure difference between the upstream side and downstream side (differential pressure between the inlet and outlet) changes. And the dryness of the fixed throttle upstream refrigerant can be self-adjusted (balanced).

  Specifically, when the pressure difference is relatively large, a balance is made so that the dryness of the fixed throttle upstream side refrigerant increases as the necessary circulation flow rate of the refrigerant that needs to circulate the cycle decreases. On the other hand, when the pressure difference is relatively small, it is balanced so that the dryness of the fixed throttle upstream side refrigerant decreases as the refrigerant circulation flow rate increases.

  Next, the valve means 16 that opens and closes the gas-phase refrigerant passage 141f and the liquid-phase refrigerant passage 142c, and the drive means 18 that displaces both the valve bodies 161 and 162 of the valve means 16 will be described.

  First, the valve means 16 will be described. The valve means 16 of the present embodiment changes the gas phase side valve element 161 that changes the passage opening degree of the gas phase refrigerant passage 141f and the passage opening degree of the liquid phase refrigerant passage 142c. A liquid phase side valve body 162 is provided.

  Each of the valve bodies 161 and 162 is disposed between a gas phase side inflow portion (gas phase side valve seat portion) 141d and a liquid phase side inflow portion (liquid phase side valve seat portion) 142a formed to face each other. Is arranged. More specifically, the gas phase side valve body 161 is disposed so as to face the gas phase side inflow portion 141d, and the liquid phase side valve body 162 is in the liquid phase side inflow on the lower side of the gas phase side valve body 161. It arrange | positions so that the part 142a may be opposed.

  The liquid-phase side valve body 162 covers a disc-shaped valve portion 162a that contacts and separates from the liquid-phase side inflow portion 142a, and a portion that exists between a valve portion 162a and a gas-phase-side valve body 161 in a rod described later. It is comprised with the member which integrated the provided annular cylindrical part 162b.

  The valve portion 162a is a portion facing the liquid phase side inflow portion 142a in the liquid phase side valve body 162, and a through hole having a size capable of sliding a rod 181 described later is formed at the center thereof. In addition, as shown in the cross-sectional view of the main part in FIG. 7, the area Sa2 of the valve portion 162a is larger than the opening area Sa1 of the liquid-phase inflow portion 142a (Sa2> Sa1).

  Further, a rubber-made first seal member 162c formed in an annular shape is formed at a portion contacting the liquid phase side inflow portion 142a on the lower surface side of the valve portion 162a and a second protrusion 181b of the rod 181 described later. Is arranged.

  As shown in FIG. 5, the first seal member 162c has a liquid phase side valve body 162 and a liquid phase side inflow portion 142a when the liquid phase side valve body 162 is displaced to a position where the liquid phase refrigerant passage 142c is closed. It functions as a member that improves the sealing performance.

  Further, as shown in FIG. 4, the first seal member 162c is in close contact with a second protrusion 181b of the rod 181 described later when the gas-phase side valve body 161 is displaced to a position where the gas-phase refrigerant passage 141f is closed. And it is also a member for suppressing that a refrigerant leaks from the crevice between liquid phase side valve element 162 and rod 181.

  Here, when the first seal member 162c is not provided, even if the gas-phase side valve body 161 closes the gas-phase refrigerant passage 141f, as shown by a one-dot chain line arrow A in FIG. There is a possibility that high-pressure refrigerant or liquid-phase refrigerant will flow into the gas-phase refrigerant passage 141f through the gap between the body 162 and the rod 181.

  Such refrigerant leakage is not preferable from the viewpoint of cycle performance and protection of the compressor 11. For example, when the high-pressure refrigerant flows into the intermediate pressure port 11c of the compressor 11 through the gas-phase refrigerant passage 141f and the intermediate pressure refrigerant passage 15 in the cooling operation mode, the temperature of the refrigerant discharged from the compressor 11 is more than necessary. As a result, the cycle performance decreases.

  For this reason, in this embodiment, when the gas-phase-side valve body 161 closes the gas-phase refrigerant passage 141f, the first seal member 162c and the second protrusion 181b are brought into close contact with each other. The first seal member 162c prevents the refrigerant from leaking from a gap between the liquid phase side valve body 162 and a rod 181 described later when the gas phase side valve body 161 closes the gas phase refrigerant passage 141f. The 2nd leakage suppression part which suppresses is comprised.

  Moreover, the cylindrical part 162b is formed in the shape where the upper end part which contacts the gaseous-phase-side valve body 161 protrudes upwards by expanding the internal diameter in the site | part on the gaseous-phase-side valve body 161 side. . The cylindrical portion 162b functions to suppress refrigerant leakage from a gap between a rod 181 and a valve portion 162a, which will be described later.

  On the other hand, the gas-phase side valve body 161 is configured by a disk-like member having a through hole having a size that allows a rod 181 (described later) to slide in the center thereof. And as shown in the principal part sectional view of Drawing 7, area Sb2 of gas phase side valve element 161 is larger than opening area Sb1 of gas phase side inflow part 141d (Sb2> Sb1).

  Here, in the present embodiment, the liquid-phase refrigerant separated in the gas-liquid separation space 141b falls to the lower side of the gas-liquid separation space 141b due to gravity.

  However, if the liquid-phase refrigerant is accumulated in the lower side of the gas-liquid separation space 141b, as shown in FIG. 8, when the gas-phase side valve element 161 opens the gas-phase-side inflow portion 141d, There is a possibility that the liquid phase refrigerant scatters to the refrigerant passage 141f side and the liquid phase refrigerant flows into the gas phase refrigerant passage 141f.

  Therefore, in the present embodiment, the area ratio of the area Sb2 of the gas phase side valve body 161 to the opening area Sb1 of the gas phase side inflow portion 141d is set to be the ratio of the area Sb2 of the liquid phase side valve body 162 to the opening area Sa1 of the liquid phase side inflow portion 142a. The area ratio of the area Sa2 is increased (Sb2 / Sb1> Sa2 / Sa1).

  Thus, by expanding the area Sb2 of the gas-phase side valve element 161 to be larger than the opening area Sb1 of the gas-phase-side inflow portion 141d, the gas-phase side valve element 161 can be opened when the gas-phase refrigerant passage 141f is opened. It can be made to function as a shutter which suppresses scattering of the liquid phase refrigerant to the phase refrigerant passage 141f side.

  In addition, a rubber-made second seal member 161a formed in an annular shape is disposed at a portion of the upper surface side of the gas phase side valve body 161 that contacts the gas phase side inflow portion 141d. As shown in FIG. 4, the second seal member 161a seals between the gas phase side valve body 161 and the gas phase side inflow portion 141d when the gas phase side valve body 161 closes the gas phase refrigerant passage 141f. It is a member for improving the property.

  In addition, a rubber-made third seal member 161b formed in an annular shape is disposed in a portion of the lower surface side of the gas phase side valve body 161 that is in contact with the cylindrical portion 162b of the liquid phase side valve body 162. . As shown in FIG. 4, the third seal member 161b is in close contact with the cylindrical portion 162b when the gas-phase side valve body 161 closes the gas-phase refrigerant passage 141f. It is a member for suppressing the refrigerant from leaking from a gap between the rod 181 described later.

  Here, when the third seal member 161b is not provided, even if the gas-phase side valve body 161 closes the gas-phase refrigerant passage 141f, as shown by a two-dot chain line arrow B in FIG. There is a possibility that high-pressure refrigerant or liquid-phase refrigerant will flow into the gas-phase refrigerant passage 141f through the gap between the valve body 161 and the rod 181.

  Such refrigerant leakage is not preferable from the viewpoint of cycle performance and protection of the compressor 11. For example, when the high-pressure refrigerant flows into the intermediate pressure port 11c of the compressor 11 through the gas-phase refrigerant passage 141f and the intermediate pressure refrigerant passage 15 in the cooling operation mode, the temperature of the refrigerant discharged from the compressor 11 is more than necessary. As a result, the cycle performance decreases.

  For this reason, in this embodiment, when the gas-phase-side valve body 161 closes the gas-phase refrigerant passage 141f, the third seal member 161b and the cylindrical portion 162b are brought into close contact with each other. Note that the third seal member 161b prevents the refrigerant from leaking from a gap between the gas phase side valve body 161 and a rod 181 described later when the gas phase side valve body 161 closes the gas phase refrigerant passage 141f. The 1st leakage suppression part which suppresses is comprised.

  Note that refrigerant leakage from the gaps between the valve bodies 161 and the rods 181 can be dealt with by arranging a seal member such as an O-ring in the gaps between the valve bodies 161 and the rods 181.

  However, when a seal member such as an O-ring is disposed in the gap between each valve body 161 and the rod 181, the seal member becomes an element (sliding resistance) that hinders the displacement of each valve body 161, 162. The operating force required when displacing the valve bodies 161 and 162 will increase. Such an increase in operating force causes an increase in the size of an electric actuator 182 of the driving means 18 described later, which is not preferable.

  For this reason, the structure which suppresses the refrigerant | coolant leakage from the clearance gap between each valve body 161 and the rod 181 with the 1st, 3rd seal member 162c, 161b arrange | positioned in the state spaced apart from the rod 181 like this embodiment. Is desirable.

  Next, the driving unit 18 will be described. The drive means 18 displaces both the valve bodies 161 and 162 to desired positions.

  Specifically, when the driving means 18 of the present embodiment displaces the gas phase side valve body 161 to the fully closed position that closes the gas phase refrigerant passage 141f, as shown in FIG. The liquid phase side valve body 162 is configured to be displaceable to a fully open position where the passage opening degree is in a fully open state.

  Further, when the driving means 18 displaces the liquid phase side valve body 162 to the fully closed position that closes the liquid phase refrigerant passage 142c, as shown in FIG. 5, the opening degree of the gas phase refrigerant passage 141f is in a fully open state. The gas phase side valve body 161 is configured to be displaceable at the fully open position.

  Furthermore, when the driving means 18 displaces the liquid-phase side valve body 162 to the fully closed position that closes the liquid-phase refrigerant passage 142c, as shown in FIG. 6, the opening degree of the gas-phase refrigerant passage 141f is more than the fully-open state. The gas-phase side valve element 161 is configured to be displaceable to a position (a fully closed position or a slightly opened position).

  Thus, the integrated valve 14 of this embodiment displaces the position of each valve body 161, 162 with the drive means 18, and the operation mode is changed into three modes, such as the 1st-3rd mode shown in FIG. Switching is possible.

  The driving means 18 of the present embodiment includes a rod 181 disposed so as to penetrate both the valve bodies 161 and 162, an electric actuator 182 that drives the rod 181 in the axial direction (vertical direction), each valve body 161, The elastic member 183 is provided between the two members 162.

  One end of the rod 181 is connected to the movable portion of the electric actuator 182, and the other end on the lower side is slidably received in a guide hole 142d formed in the lower block 142. The rod 181 of the present embodiment is arranged so that its axis coincides with the axis of the pipe portion 141c and penetrates the internal space of the pipe portion 141c.

  When the gas-phase side valve body 161 is displaced to a position where the gas-phase refrigerant passage 141f is opened, the rod 181 contacts the gas-phase side valve body 161 and is in contact with the gas-phase-side valve body 161. A first protrusion 181a is provided for applying a load in a direction away from 141d (downward). The first protrusion 181a is a bowl-shaped member that protrudes in a direction perpendicular to the axial direction of the rod 181 and is fixed to the upper side of the gas-phase-side valve body 161 in the rod 181 by caulking or the like.

  Further, when the liquid phase side valve body 162 is displaced to the position where the liquid phase refrigerant passage 142c is opened, the rod 181 contacts the liquid phase side valve body 162 and is liquid side with respect to the liquid phase side valve body 162. A second protrusion 181b is provided to apply a load in a direction (upward) away from the inflow portion 142a. The second protrusion 181 b is a bowl-shaped member that protrudes in a direction perpendicular to the axial direction of the rod 181, and is integrally formed with the rod 181 on the lower side of the liquid phase side valve body 162.

  The second projecting portion 181b of the present embodiment is formed in a shape in which a portion on the upper surface side protrudes upward so as to come into contact with the first seal member 162c when contacting the liquid phase side valve body 162. ing.

  Here, in this embodiment, the space | interval of the 1st, 2nd protrusion part 181a, 181b is larger than the space | interval between the gaseous-phase side inflow part 141d and the liquid phase side inflow part 142a. Thereby, in this embodiment, when the rod 181 is driven, the first and second protrusions 181a and 181b are not in contact with the gas phase side inflow portion 141d and the liquid phase side inflow portion 142a. It is possible.

  The electric actuator 182 displaces the valve bodies 161 and 162 by driving the rod 181 in the vertical direction. In this embodiment, a stepping motor is employed as the electric actuator 182.

  The operation of the electric actuator 182 of this embodiment is controlled by a control pulse output from the air conditioning controller 40 described later. When the electric actuator 182 is configured by a stepping motor, when the control pulse output from the air-conditioning control device 40 is stopped, the position of each valve element 161, 162 depends on the frictional force of the feed screw and the magnet holding torque. Retained.

  The elastic member 183 is a member that applies a load to the valve bodies 161 and 162 so as to be separated from each other, and is configured by a spring such as a coil spring. Specifically, the elastic member 183 applies a load to the gas phase side valve body 161 in a direction in contact with the gas phase side inflow portion 141d, and the liquid phase side inflow portion with respect to the liquid phase side valve body 162. It arrange | positions between each valve body 161, 162 so that a load may act in the direction which contacts 142a.

  The electric actuator 182 drives the rod 181 upward when the liquid phase refrigerant passage 142c is opened by the liquid phase side valve body 162. As a result, as shown in FIG. 4, the second protrusion 181b of the rod 181 and the liquid phase side valve body 162 come into contact with each other, and the liquid phase side valve body 162 is separated from the liquid phase side inflow portion 142a. A load is applied. At this time, the gas-phase refrigerant passage 141f is closed by displacing the gas-phase-side valve body 161 at a position where it abuts on the gas-phase-side inflow portion 141d due to the load of the elastic member 183.

  In addition, the electric actuator 182 drives the rod 181 downward when the gas-phase-side valve body 161 opens the gas-phase refrigerant passage 141f. As a result, as shown in FIG. 5, the first protrusion 181a of the rod 181 and the gas phase side valve body 161 come into contact with each other, and the gas phase side valve body 161 is separated from the gas phase side inflow portion 141d. A load is applied. At this time, the liquid phase refrigerant passage 142c is closed by the liquid phase side valve body 162 being displaced to a position where it abuts on the liquid phase side inflow portion 142a due to the load of the elastic member 183.

  Here, when the liquid phase refrigerant passage 142c and the gas phase refrigerant passage 141f are closed by the valve bodies 161 and 162, the electric actuator 182 includes the projections 181a and 181b, respectively, the gas phase side inflow portion 141 and the liquid phase. The rod 181 is driven to a position not in contact with the side inflow portion 142.

  As a result, as shown in FIG. 6, no load is applied to each valve body 161, 162 from each projection 181a, 181b, and each valve body 161, 162 is placed at a position where it abuts on each inflow portion 141d, 142a by the load of the elastic member 183. As the valve bodies 161 and 162 are displaced, both the refrigerant passages 141f and 142c are closed.

  When the liquid-phase refrigerant passage 142c is closed and the gas-phase refrigerant passage 141f is opened slightly, the electric actuator 182 includes the protrusions 181a and 181b that are connected to the gas-phase-side inflow portion 141 and the liquid-phase-side inflow portion. The rod 181 is driven slightly downward from a position that does not contact 142.

  As a result, the first protrusion 181a of the rod 181 contacts the gas phase side valve body 161, and a load is applied to the gas phase side valve body 161 in a direction away from the gas phase side inflow portion 141d. The phase-side valve body 161 is slightly displaced to a position at which the gas-phase refrigerant passage 141f is opened. At this time, the liquid phase refrigerant passage 142c is closed by the liquid phase side valve body 162 being displaced to a position where it abuts on the liquid phase side inflow portion 142a due to the load of the elastic member 183.

  Returning to FIGS. 1 to 3, the refrigerant inlet side of the outdoor heat exchanger 20 is connected to the liquid-phase side outlet 142 b of the integrated valve 14. The outdoor heat exchanger 20 is disposed in the bonnet, and exchanges heat between the refrigerant circulating inside and the air outside the vehicle (outside air) blown from the blower fan 21. The outdoor heat exchanger 20 functions as an evaporator that evaporates the refrigerant in the first and second heating modes and exerts a heat absorbing action, and functions as a radiator that radiates the refrigerant in the cooling operation mode and the like. It is an exchanger.

  The refrigerant inlet side of the low stage side expansion valve 22 is connected to the refrigerant outlet side of the outdoor heat exchanger 20. The low stage side expansion valve 22 depressurizes the refrigerant that flows out of the outdoor heat exchanger 20 and flows into the indoor evaporator 23 in the cooling operation mode or the like. The basic configuration of the low stage side expansion valve 22 is the same as that of the high stage side expansion valve 13, and its operation is controlled by a control signal output from the air conditioning controller 40.

  The refrigerant inlet side of the indoor evaporator 23 is connected to the outlet side of the low stage side expansion valve 22. The indoor evaporator 23 is disposed in the air conditioning case 31 of the indoor air conditioning unit 30 on the upstream side of the air flow of the indoor condenser 12, and evaporates the refrigerant during the cooling operation mode or the dehumidifying heating operation mode to absorb heat. It is a heat exchanger that cools the air blown into the vehicle interior by exhibiting the above.

  The inlet side of the accumulator 24 is connected to the refrigerant outlet side of the indoor evaporator 23. The accumulator 24 separates the gas-liquid refrigerant flowing into the accumulator 24 and stores excess refrigerant. Further, the suction port 11 a of the compressor 11 is connected to the gas phase refrigerant outlet side of the accumulator 24. Therefore, the indoor evaporator 23 is connected so as to flow out to the suction port 11 a side of the compressor 11.

  Further, on the refrigerant outlet side of the outdoor heat exchanger 20, there is a bypass passage 25 that guides the refrigerant flowing out of the outdoor heat exchanger 20 to the inlet side of the accumulator 24 by bypassing the low-stage expansion valve 22 and the indoor evaporator 23. It is connected.

  A bypass opening / closing valve 251 is disposed in the bypass passage 25. The bypass opening / closing valve 251 is an electromagnetic valve that opens and closes the bypass passage 25, and its opening / closing operation is controlled by a control signal output from the air conditioning controller 40.

  The bypass on-off valve 251 of the present embodiment functions to switch the cycle configuration (refrigerant flow path) by opening and closing the bypass passage 25. Therefore, the bypass on-off valve 251 of this embodiment constitutes a refrigerant flow path switching unit that switches the refrigerant flow path of the refrigerant circulating in the cycle. Note that the pressure loss that occurs when the refrigerant passes through the bypass on-off valve 251 is extremely small relative to the pressure loss that occurs when the refrigerant passes through the low-stage expansion valve 22.

  Accordingly, the refrigerant flowing out of the outdoor heat exchanger 20 flows into the accumulator 24 via the bypass passage 25 when the bypass on-off valve 251 is open, and low when the bypass on-off valve 251 is closed. It flows into the indoor evaporator 23 through the stage side expansion valve 22.

  Next, the indoor air conditioning unit 30 will be described. The indoor air conditioning unit 30 is arranged inside the instrument panel (instrument panel) at the foremost part of the vehicle interior to form an outer shell of the indoor air conditioning unit 30 and to the interior of the room air blown into the vehicle interior. It has an air conditioning case 31 that forms an air passage. And the air blower 32, the above-mentioned indoor condenser 12, the indoor evaporator 23, etc. are accommodated in this air passage.

  On the most upstream side of the air flow in the air conditioning case 31, an inside / outside air switching device 33 that switches and introduces vehicle interior air (inside air) and outside air is disposed. The inside / outside air switching device 33 continuously adjusts the opening area of the inside air introduction port for introducing the inside air into the air conditioning case 31 and the outside air introduction port for introducing the outside air by the inside / outside air switching door, so that the air volume of the inside air and the outside air are adjusted. The air volume ratio with the air volume is continuously changed.

  On the downstream side of the air flow of the inside / outside air switching device 33, a blower 32 that blows air sucked through the inside / outside air switching device 33 toward the vehicle interior is arranged. The blower 32 is an electric blower that drives a centrifugal multiblade fan (sirocco fan) with an electric motor, and the number of rotations (air flow rate) is controlled by a control signal output from the air conditioning control device 40.

  On the downstream side of the air flow of the blower 32, the indoor evaporator 23 and the indoor condenser 12 are arranged in the order of the indoor evaporator 23 → the indoor condenser 12 with respect to the flow of the indoor blown air. In other words, the indoor evaporator 23 is disposed on the upstream side of the air flow with respect to the indoor condenser 12.

  Further, a bypass passage 35 is provided in the air conditioning case 31 to flow the blown air after passing through the indoor evaporator 23, bypassing the indoor condenser 12, on the downstream side of the air flow of the indoor evaporator 23. An air mix door 34 is disposed on the upstream side of the air flow of the indoor condenser 12.

  The air mix door 34 adjusts the air volume ratio between the air volume that passes through the indoor condenser 12 and the air volume that passes through the bypass passage 35 in the blown air that has passed through the indoor evaporator 23, and the heat of the indoor condenser 12. It is a heat exchange capacity adjustment means for adjusting the exchange capacity. The air mix door 34 is driven by a servo motor (not shown) whose operation is controlled by a control signal output from the air conditioning controller 40.

  Further, on the downstream side of the air flow of the indoor condenser 12 and the bypass passage 35, blown air heated by exchanging heat with the refrigerant in the indoor condenser 12 and blown air not heated through the bypass passage 35 are present. A merge space 36 for merging is provided.

  In the most downstream part of the air flow of the air conditioning case 31, an opening hole is formed through which the blown air merged in the merge space 36 is blown out to the vehicle interior that is the air conditioning target space. Specifically, the defroster opening hole 37a that blows the conditioned air toward the inner side surface of the front window glass of the vehicle, the face opening hole 37b that blows the conditioned air toward the upper body of the passenger in the vehicle interior, and the conditioned air toward the feet of the passenger A foot opening hole 37c to be blown out is formed.

  The air flow downstream side of each of the opening holes 37a to 37c is connected to a face air outlet, a foot air outlet, and a defroster air outlet provided in the vehicle interior via ducts that form air passages.

  Further, a defroster door 38a that opens and closes the defroster opening hole 37a, a face door 38b that opens and closes the face opening hole 37b, and a foot door 38c that opens and closes the foot opening hole 37c are arranged on the upstream side of the air flow of each opening hole 37a to 37c. ing. Each door 38a-38c comprises the blowing mode switching means which switches the blowing mode of the air to a vehicle interior. Each door 38a to 38c is driven by a servo motor (not shown) whose operation is controlled by a control signal output from the air conditioning control device 40.

  Next, the electric control unit of this embodiment will be described. The air conditioning control device 40 includes a known microcomputer including a CPU, a ROM, a RAM, and the like and peripheral circuits thereof. The air conditioning control device 40 performs various calculations and processing based on a control program stored in a ROM or the like, and controls each control device (compressor 11, high stage expansion valve 13, integrated valve 14, bypass) connected to the output side. The operation of the on-off valve 251 and the blower 32).

  A sensor group 41 for various air conditioning controls is connected to the input side of the air conditioning control device 40. The sensor group 41 includes an inside air sensor that detects the temperature in the vehicle interior, an outside air sensor that detects the outside air temperature, a solar radiation sensor that detects the amount of solar radiation in the vehicle interior, an evaporator temperature sensor that detects the temperature of the indoor evaporator 23, and a compressor. 11 is a discharge pressure sensor that detects the pressure of the high-pressure refrigerant discharged from No. 11.

  Further, an operation panel (not shown) arranged near the instrument panel is connected to the input side of the air conditioning control device 40, and operation signals from various air conditioning operation switches provided on the operation panel are input. As various air conditioning operation switches provided on the operation panel, specifically, an operation switch of the vehicle air conditioner 1, a temperature setting switch for setting the passenger compartment temperature, a selection switch between the cooling operation mode and the heating operation mode, and the like are provided. It has been.

  Here, the air-conditioning control device 40 is configured such that control means for controlling the operation of each control device connected to the output side is integrally configured, but the configuration for controlling the operation of each control device (hardware and Software) constitutes control means for controlling the operation of each control device.

  For example, in this embodiment, the structure (hardware and software) which controls the integrated valve 14 in the air-conditioning control apparatus 40 comprises the drive control means 40a. In this embodiment, the integrated valve 14 and the drive control means 40a constitute a drive system for the integrated valve 14. The drive control means 40 a in the air conditioning control device 40 may be configured by a control device different from the air conditioning control device 40.

  Next, the operation of the vehicle air conditioner 1 of the present embodiment will be described. The vehicle air conditioner 1 can be switched to a cooling operation mode, a heating operation mode, and a dehumidifying heating operation mode. Switching between the operation modes is performed by a control process of the air conditioning control device 40.

  The operation mode switching control process executed by the air conditioning control device 40 of the present embodiment will be described with reference to the flowchart of FIG. The control routine shown in FIG. 11 starts when the operation switch of the vehicle air conditioner 1 is turned on (ON operation) on the operation panel.

  As shown in FIG. 11, first, various signals are read from the various air conditioning control sensor group 41 and the operation panel (S10), and the operation mode of the heat pump cycle 10 is determined based on the read various signals (S12). .

  In the present embodiment, the operation mode of the vehicle air conditioner 1 is determined according to the detection switch of the operation panel, the temperature setting switch, and the detected values of the outside air temperature sensor.

  For example, when the setting temperature of the setting switch is equal to or lower than the detection value of the outside air temperature sensor, when the selection switch on the operation panel is set to cooling, the operation mode is determined to be the cooling operation mode. When the operation mode is determined to be the cooling operation mode, the operation mode flag is set to a value (for example, 0) indicating “cooling”.

  And when the setting temperature of a setting switch is higher than the detection value of an outside air temperature sensor, if the selection switch of an operation panel is set to air_conditioning | cooling, an operation mode will be determined to dehumidification heating operation mode. When the operation mode is determined to be the dehumidifying / heating operation mode, the operation mode flag is set to a value (for example, 1) indicating “dehumidifying / heating”.

  Further, when the outside air temperature is extremely low (for example, the detected value of the outside air temperature sensor is 0 ° C. or less), when the selection switch on the operation panel is set to heating, the refrigerant circuit of the heat pump cycle 10 is gas-injected. The first heating mode is determined as a cycle (two-stage compression cycle). When the operation mode is determined to be the first heating mode, the operation mode flag is set to a value (for example, 2) indicating “first heating”.

  Then, when the outside air temperature is not extremely low, when the selection switch on the operation panel is set to heating, the second heating mode in which the refrigerant circuit of the heat pump cycle 10 is set to the normal one-stage compression cycle is determined. When the operation mode is determined to be the second heating mode, the operation mode flag is set to a value (for example, 3) indicating “second heating”.

  Subsequently, it is determined whether or not the operation mode determined in step S12 is the cooling operation mode (S14), and when it is determined that the operation mode is the cooling operation mode, the cooling control process is executed (S16). .

  Subsequently, it is determined whether or not to stop the air conditioning (S18). If it is determined not to stop the air conditioning, the process returns to step S10 to read various signals again. On the other hand, when it is determined to stop the air conditioning, the operation mode switching control is finished. Whether or not to stop the air conditioning may be determined, for example, based on whether or not the operation switch is turned off.

  As a result of the determination process in step S14, when it is determined that the cooling operation mode is not selected, it is determined whether or not the first heating mode is selected (S20). As a result, when it determines with it being 1st heating mode, 1st heating control processing is performed (S22) and it transfers to step S18 after that.

  On the other hand, as a result of the determination process in step S20, if it is determined that the first heating mode is not selected, it is determined whether or not the second heating mode is selected (S24). As a result, when it determines with it being the 2nd heating mode, a 2nd heating control process is performed (S26), and it transfers to step S18 after that.

  As a result of the determination process in step S24, when it is determined that it is not the second heating mode, a dehumidification heating control process is executed (S28), and then the process proceeds to step S18. Each determination of steps S14, S20, and S24 is processed based on the value of the operation mode flag set in step S12.

  Next, the contents of the control process executed in steps S16, S22, S26, and S28 of FIG. 11 and the operation of the vehicle air conditioner 1 in each operation mode will be described.

(A) Cooling control processing (cooling operation mode)
In the cooling control process, the air conditioning control device 40 fully opens the high stage side expansion valve 13 (a state in which the pressure reducing action is not exerted), the low stage side expansion valve 22 is in a throttling state (a state in which the pressure reducing action is exerted), The valve 251 is closed.

  Further, the air-conditioning control device 40 controls the electric actuator 182 so that the gas phase side valve body 161 is displaced to the fully closed position of the gas phase refrigerant passage 141f and the liquid phase side valve body 162 is displaced to the fully open position of the liquid phase refrigerant passage 142c. In contrast, a control pulse is output. Thereby, as shown in FIG. 4, the integrated valve 14 is switched to the first mode in which the opening degree of the liquid-phase refrigerant passage 142c is fully opened while the gas-phase refrigerant passage 141f is closed.

  Therefore, in the heat pump cycle 10, as shown by the solid line arrow in FIG.

  With this refrigerant circuit configuration, the air conditioning control device 40 reads the detection signal of the sensor group 41 for air conditioning control and the operation signal of the operation panel, and calculates the target blowing temperature TAO, which is the target temperature of the air blown into the passenger compartment. Furthermore, the operating state of each control device connected to the output side of the air conditioning control device 40 is determined based on the calculated target blowing temperature TAO and the detection signal of the sensor group.

  For example, the control signal output to the electric motor of the compressor 11 is determined as follows. First, the target evaporator outlet temperature TEO of the indoor evaporator 23 is determined based on the target outlet temperature TAO with reference to a control map stored in the air conditioning controller 40 in advance. And the control signal output to the electric motor of the compressor 11 is determined so that the detected value (blowing air temperature) of the evaporator temperature sensor approaches the target evaporator blowing temperature TEO.

  As for the control signal output to the low-stage side expansion valve 22, the target supercooling degree that is determined in advance so that the degree of supercooling of the refrigerant flowing into the low-stage side expansion valve 22 approaches the COP substantially to the maximum value. It is decided to approach.

  Regarding the control signal output to the servo motor of the air mix door 34, the air mix door 34 closes the air passage of the indoor condenser 12, and the total flow rate of the blown air after passing through the indoor evaporator 23 is the bypass passage 35. Is determined to pass.

  Then, the control signal determined as described above is output to each control device. Thereafter, reading of each signal → calculation of the target blowout temperature TAO → determination of the operating state of each control device → output of the control signal at every predetermined control period until the operation stop of the vehicle air conditioner 1 is requested by the operation panel The control routine is repeated. Such a control routine is repeated in the other operation modes.

Therefore, in the heat pump cycle 10 of the cooling operation mode, as shown in the Mollier diagram of FIG. 12, the inflow high pressure refrigerant discharged from the outlet port 11b of the compressor 11 (a ₁₁ point in FIG. 12) to the indoor condenser 12 To do. At this time, since the air mix door 34 closes the air passage of the indoor condenser 12, the refrigerant flowing into the indoor condenser 12 flows out of the indoor condenser 12 without radiating heat to the indoor blowing air.

  Since the high-stage expansion valve 13 is fully opened, the refrigerant flowing out of the indoor condenser 12 is almost not decompressed by the high-stage expansion valve 13 and enters the gas-liquid separation space 141b in the integrated valve 14. Inflow.

  At this time, the refrigerant flowing into the gas-liquid separation space 141b is in a gas phase state having a superheat degree, but the gas phase refrigerant passage 141f is fully closed by the gas phase side valve body 161. Therefore, the refrigerant that has flowed into the gas-liquid separation space 141b flows into the liquid-phase refrigerant passage 142c without flowing out from the gas-phase side outlet 141e, as shown in FIG. The refrigerant that has flowed into the gas-liquid separation space 141 b is almost completely decompressed by the fixed throttle 17 without being reduced in pressure because the liquid-phase refrigerant passage 142 c is fully opened by the liquid-phase side valve body 162. And flows out from the liquid-phase side outlet 142b of the integrated valve 14.

The refrigerant flowing out from the liquid-phase side outlet 142b of the integrated valve 14 flows into the outdoor heat exchanger 20, and heat is exchanged with the outside air blown from the blower fan 21 in the outdoor heat exchanger 20 to dissipate heat (FIG. 12). A ₁₁ points → b ₁₁ points). Since the bypass on / off valve 251 is closed, the refrigerant that has flowed out of the outdoor heat exchanger 20 enters the throttled low-stage expansion valve 22 until it becomes a low-pressure refrigerant. reduced pressure is expanded in manner _{(b 11} points in FIG. 12 → _{c 11} points).

The refrigerant decompressed by the low stage side expansion valve 22, flows into the indoor evaporator 23, and absorbs heat from the air in-room air blown from the blower 32 to evaporate (c ₁₁ points in FIG. 12 → d ₁₁ points ). Thereby, indoor ventilation air is cooled.

The refrigerant flowing out of the indoor evaporator 23 flows into the accumulator 24 and is separated into gas and liquid. Then, the suction port 11a of the separated gas-phase refrigerant compressor 11 is sucked from the _{(e 11} points in FIG. 12), it is compressed again _{(e 11} points in FIG. 12 → _{a1 11} points → _{a 11} points). In addition, the liquid phase refrigerant | coolant isolate | separated in the accumulator 24 is stored in the accumulator 24 as a surplus refrigerant | coolant which is not required in order to exhibit the refrigerating capacity for which the cycle is requested | required.

Here, the reason why the point d _{11 and the} point e ₁₁ are different in FIG. 12 is that the pressure loss generated in the gas phase refrigerant flowing through the refrigerant pipe from the accumulator 24 to the suction port 11a of the compressor 11 and the gas phase refrigerant are This represents the amount of heat absorbed from the outside (outside air). Therefore, in an ideal cycle, it is desirable that d ₁₁ points and e ₁₁ points match. The same applies to the following Mollier diagram.

  As described above, in the cooling operation mode, since the air passage of the indoor condenser 12 is closed by the air mix door 34, the blown air cooled by the indoor evaporator 23 can be blown out into the vehicle interior. Thereby, cooling of a vehicle interior is realizable.

(B) 1st heating control process (1st heating mode)
In the first heating control process, the air-conditioning control device 40 opens the high stage expansion valve 13 in a throttled state (a state in which a pressure reducing action is exerted), fully closes the low stage expansion valve 22, and opens the bypass on-off valve 251. State.

  In the first heating control process, basically, the air-conditioning control device 40 is configured so that the gas-phase side valve element 161 is fully open in the gas-phase refrigerant passage 141f and the liquid-phase side valve element 162 is in the entire liquid-phase refrigerant passage 142c. A control pulse is output to the electric actuator 182 so as to be displaced to the closed position. Thereby, as shown in FIG. 5, the integrated valve 14 is switched to the second mode in which the opening degree of the liquid-phase refrigerant passage 142c is fully closed with the gas-phase refrigerant passage 141f opened.

  Accordingly, the heat pump cycle 10 is switched to a refrigerant circuit through which a refrigerant flows, that is, a refrigerant circuit of a gas injection cycle, as indicated by a solid arrow in FIG.

  With the configuration of the refrigerant circuit, the air conditioning control device 40 determines the operating state of each control device connected to the output side of the air conditioning control device 40 based on the target blowing temperature TAO and the detection signal of the sensor group 41. In the first heating mode, the control signal output to the high stage side expansion valve 13 flows out from the indoor condenser 12 so that the refrigerant pressure in the indoor condenser 12 becomes a predetermined target high pressure. The degree of supercooling of the refrigerant is determined to be a predetermined target degree of supercooling. For the control signal output to the servo motor of the air mix door 34, the air mix door 34 closes the bypass passage 35, and the entire flow rate of the blown air after passing through the indoor evaporator 23 passes through the indoor condenser 12. To be determined.

Therefore, in the heat pump cycle 10 in the first heating mode, as shown in the Mollier diagram of FIG. 13, the high-pressure refrigerant (point ₁₂ a in FIG. 13) discharged from the discharge port 11 b of the compressor 11 goes to the indoor condenser 12. Inflow. The refrigerant flowing into the indoor condenser 12, the blower 32 is blown from the radiating heat cabin blown air by heat exchange through the interior evaporator 23 (a ₁₂ point of FIG. 13 → b ₁₂ points). Thereby, vehicle interior blowing air is heated.

The refrigerant flowing from the indoor condenser 12 is isenthalpic depressurize expansion in to have the high-stage expansion valve 13 to a stop state until the intermediate-pressure refrigerant (b ₁₂ points in FIG. 13 → c1 ₁₂ points) . The intermediate-pressure refrigerant decompressed by the high-stage expansion valve 13 is a refrigerant inlet 141a flows into the gas-liquid separation space 141b gas-liquid separation of the integrated valve 14 (c ₁₂ points in FIG. 13 → c2 _{12 points, 12} points _c → _{c3 12} points).

As shown in FIG. 5, the liquid-phase refrigerant separated in the gas-liquid separation space 141b is completely closed by the liquid-phase side valve body 162. It is decompressed and expanded in an enthalpy manner until it becomes (c12 ₁₂ points → c4 ₁₂ points in FIG. 13), and flows out from the liquid phase side outlet 142b.

Further, the gas-phase refrigerant separated in the gas-liquid separation space 141b flows out from the gas-phase side outlet 141e of the integrated valve 14 because the gas-phase refrigerant passage 141f is fully opened by the gas-phase side valve body 161. It flows into the intermediate pressure port 11c side of the compressor 11 ( ₁₂ points c2 in FIG. 13).

The refrigerant flowing into the intermediate pressure port 11c merges with the refrigerant in the compression process of the compressor 11 (a1 ₁₂ points in FIG. 13) and is compressed (a2 ₁₂ points in FIG. 13).

Subsequently, the refrigerant flowing out from the liquid phase side outlet 142b of the integrated valve 14 flows into the outdoor heat exchanger 20 and exchanges heat with the outside air blown from the blower fan 21 to absorb heat (c4 _{12 in} FIG. 13). Point → d ₁₂ points).

The refrigerant flowing out of the outdoor heat exchanger 20 flows into the accumulator 24 via the bypass passage 25 and is separated into gas and liquid because the bypass on-off valve 251 is in the open state. The compressed again separated gas-phase refrigerant is sucked from the suction port 11a of the compressor 11 (e ₁₂ points in FIG. 13). On the other hand, the separated liquid-phase refrigerant is stored in the accumulator 24 as surplus refrigerant that is not necessary for exhibiting the refrigerating capacity required for the cycle.

  As described above, in the first heating mode, the heat of the refrigerant discharged from the compressor 11 by the indoor condenser 12 is dissipated to the vehicle interior blown air, and the heated room blown air is blown out into the vehicle interior. it can. Thereby, heating of a vehicle interior is realizable.

  Further, in the first heating mode, the low-pressure refrigerant decompressed by the fixed throttle 17 is sucked from the suction port 11a of the compressor 11, and the intermediate-pressure refrigerant decompressed by the high stage side expansion valve 13 is sent to the intermediate pressure port 11c. A gas injection cycle (economizer-type refrigeration cycle) can be configured to flow in and merge with the refrigerant in the pressure increasing process.

  Accordingly, the refrigerant refrigerant having a low temperature can be sucked into the compressor 11, and the compression efficiency in the compressor 11 can be improved. As a result, the COP of the heat pump cycle 10 as a whole can be improved.

  Here, in the first heating mode, when the gas-phase refrigerant passage 141 f is always fully open, the liquid-phase refrigerant flows into the gas-phase refrigerant passage 141 f and passes through the intermediate-pressure refrigerant passage 15. Liquid phase refrigerant may be sucked.

  According to the investigation by the present inventors, such a problem is caused by the initial stage of switching from another operation mode to the first heating mode, and when the load state of the compressor 11 is a predetermined high load state during the first heating mode. It has been found that this is likely to occur during the transition period. Hereinafter, the cause of the problem that the liquid refrigerant flows into the gas-phase refrigerant passage 141f in the first heating mode will be described with reference to FIGS.

  Here, FIG. 15 shows the high-stage side expansion valve 13, the refrigerant pressure in the cycle, and the compressor 11 when the operation mode is switched from the other operation mode (assuming the second heating mode in the present embodiment) to the first heating mode. It is a timing chart which shows the change of rotation speed. In addition, time Ta1 shown in FIG. 15 has shown the switching timing from other operation modes to 1st heating mode. Further, among the refrigerant pressures in FIG. 15, the solid line P1 indicates the pressure change of the high-pressure refrigerant discharged from the compressor 11, the dotted line P2 indicates the pressure change of the low-pressure refrigerant sucked into the compressor 11, and the alternate long and short dash line P3 indicates the fixed throttle 17. The refrigerant pressure change before passing and the two-dot chain line P4 show the refrigerant pressure change after passing through the fixed throttle 17. This also applies to the refrigerant pressure change shown in FIG.

  As shown in FIG. 15, when the operation mode is changed to the first heating mode (time Ta1), the liquid-phase refrigerant passage 104d is fully closed by the liquid-phase side valve body 162, All of the liquid-phase refrigerant separated in the liquid separation space 141 b flows into the fixed throttle 17. As a result, the flow rate of the refrigerant passing through the fixed throttle 17 increases rapidly.

  As shown in FIG. 14, the refrigerant flow rate Gr has a characteristic proportional to the pressure difference ΔP (= Pin−Pout) before and after the fixed throttle 17. For this reason, when the flow rate of the refrigerant passing through the fixed throttle 17 is increased (Gr1 → Gr2: Gr1 <Gr2), the cycle is balanced so that the pressure of the low-pressure refrigerant in the cycle rapidly decreases (see dotted line P2 in FIG. 15). ).

  Then, due to a rapid pressure drop of the low-pressure refrigerant in the cycle, forming (boiling, bumping) occurs in the accumulator 24 on the downstream side of the fixed throttle 17, and surplus refrigerant stored in the accumulator 24 is sucked into the intake port 11a of the compressor 11. Inhaled. This increases the flow rate of the refrigerant circulating in the cycle.

  Here, the time until the flow rate of the refrigerant circulating in the cycle increases is until the pressure difference ΔP (= P3−P4) before and after the fixed throttle 17 increases to a level at which all the liquid-phase refrigerant can flow through the fixed throttle 17. Is shorter than the time (time Ta1 to time Ta2 in FIG. 14).

  For this reason, in the fixed throttle 17, when the flow rate of the refrigerant circulating in the cycle increases, all of the liquid-phase refrigerant cannot be flowed, and the liquid-phase refrigerant that cannot be flowed through the fixed throttle 17 is the gas-phase refrigerant. At the same time, the refrigerant flows into the intermediate-pressure refrigerant passage 15 via the gas-phase refrigerant passage 141f.

  As described above, when switching from the state in which another operation mode is being executed or the air-conditioning stop state to the first heating mode, the liquid-phase refrigerant flows into the gas-phase refrigerant passage 141f, and the intermediate-pressure refrigerant passage 15 The liquid phase refrigerant may be sucked into the compressor 11 via the.

  FIG. 16 is a timing chart showing changes in the high-stage side expansion valve 13, the refrigerant pressure in the cycle, and the rotation speed of the compressor 11 when the load state of the compressor 11 becomes a high load state. In addition, time Tb1 shown in FIG. 16 has shown the timing when the load state of the compressor 11 became a high load state.

  As shown in FIG. 16, in a steady period (a period up to time Tb1) in which the load state of the compressor 11 is low, the pressure difference ΔP (= P3-P4) before and after the fixed throttle 17 is large and fixed with respect to the refrigerant flow rate. The diaphragm 17 can sufficiently flow the liquid phase refrigerant.

  From this state, during the transitional period (time Tb1) in which the rotation speed of the compressor 11 suddenly increases due to a change in the set temperature of the passenger compartment and the load state of the compressor 11 shifts to a high load state (time Tb1). The flow rate of the refrigerant passing through 17 increases rapidly.

  As a result, the cycle is balanced so that the pressure of the low-pressure refrigerant in the cycle rapidly decreases (see dotted line P2 in FIG. 16). Then, due to the rapid pressure drop of the low-pressure refrigerant in the cycle, forming occurs in the accumulator 24 on the downstream side of the fixed throttle 17, and surplus refrigerant stored in the accumulator 24 is sucked into the suction port 11a of the compressor 11. As a result, the flow rate of the refrigerant circulating in the cycle increases. As a result, the fixed throttle 17 cannot completely flow the liquid refrigerant, and the liquid refrigerant that cannot flow through the fixed throttle 17 passes through the gas-phase refrigerant path 141f together with the gas-phase refrigerant. 15 flows into.

  Thus, even during the execution of the first heating mode, in the transition period when the load state of the compressor 11 shifts to the high load state, the liquid-phase refrigerant flows into the gas-phase refrigerant passage 141f, and the intermediate-pressure refrigerant The liquid refrigerant may be sucked into the compressor 11 through the passage 15.

  In the present embodiment, as a countermeasure against the problem that the liquid phase refrigerant is sucked into the compressor 11 through the intermediate pressure refrigerant passage 15, the liquid inflow condition in which the liquid phase refrigerant flows into the intermediate pressure refrigerant passage 15 is satisfied. The operation mode of the integrated valve 14 is switched to the third mode.

  The mode switching process of the integrated valve 14 of this embodiment will be described with reference to the flowchart of FIG. Note that the control routine of FIG. 17 is a process executed in the first heating mode.

  As shown in FIG. 17, first, it is determined whether or not the previous operation mode of the heat pump cycle 10 is not the first heating mode but another operation mode (S241). That is, it is determined whether or not the operation mode of the heat pump cycle 10 is an initial stage in which the operation mode other than the first heating mode is switched to the first heating mode. In the determination process of step S241, it is determined whether or not the previous operation mode flag matches the current operation mode flag. If they do not match, it is determined that the previous operation mode is another operation mode.

  As a result of the determination process in step S241, when it is determined that the previous operation mode is an operation mode other than the first heating mode, the liquid inflow condition is satisfied and the compression is performed via the intermediate pressure refrigerant passage 15. There is a possibility that the liquid refrigerant is sucked into the machine 11.

  For this reason, the air-conditioning control apparatus 40 switches the operation mode of the integrated valve 14 to the third mode, and executes the injection suppression operation (S242). Specifically, in the air conditioning control device 40, the liquid phase side valve body 162 is in the fully closed position of the liquid phase refrigerant passage 142c, and the gas phase side valve body 161 is in the fully closed position (or slightly open position) of the gas phase refrigerant passage 141f. A control pulse is output to the electric actuator 182 so as to be displaced to. As a result, the integrated valve 14 is switched to the third mode in which the gas-phase refrigerant passage 141f has a passage opening smaller than that in the fully opened state with the liquid-phase refrigerant passage 142c closed. In this third mode, as shown in FIG. 6, the liquid phase refrigerant separated in the gas-liquid separation space 141b is decompressed and expanded in an enthalpy manner until it becomes a low pressure refrigerant in the fixed throttle 17, and the liquid phase side It flows out from the outflow port 142b.

  At this time, since the gas-phase refrigerant passage 141f is fully closed or slightly opened by the gas-phase side valve body 161, the liquid-phase refrigerant hardly flows into the gas-phase refrigerant passage 141f via the fixed restrictor 17. It flows out from the liquid phase side outlet 142b. The gas-phase refrigerant separated in the gas-liquid separation space 141b is inflow into the gas-phase refrigerant passage 141f because the gas-phase refrigerant passage 141f is fully closed or slightly opened by the gas-phase side valve body 161. Is limited.

  Returning to FIG. 17, after switching the operation mode of the integrated valve 14 to the third mode, it is determined whether or not a predetermined return condition is satisfied (S243).

  In the present embodiment, the return condition in step S243 is set to a condition that is satisfied when a predetermined reference time has elapsed since switching to the third mode. The reference time is set to the time required for the pressure difference before and after the fixed throttle 17 to increase to a level at which all of the liquid refrigerant can flow through the fixed throttle 17 after the operation mode of the heat pump cycle 10 is switched to the first heating mode. Has been. Note that the reference time may be set, for example, based on the longer one of the time from time Ta1 to time Ta2 shown in FIG. 15 and the time from time Tb1 to time Tb2 shown in FIG.

  As a result of the determination processing in step S243 shown in FIG. 17, if it is determined that the return condition is not satisfied, the process returns to step S242. That is, until the return condition is satisfied, the operation mode of the integrated valve 14 is maintained in the third mode.

  Further, when it is determined that the return condition is satisfied as a result of the determination processing in step S243, it is considered that the pressure difference before and after the fixed throttle 17 has expanded to a level at which all the liquid refrigerant can flow through the fixed throttle 17. It is done.

  For this reason, the air-conditioning control apparatus 40 switches the operation mode of the integrated valve 14 to the second mode, and executes the injection operation (S244). Specifically, the air-conditioning control device 40 is electrically operated so that the liquid phase side valve body 162 is displaced to the fully closed position of the liquid phase refrigerant passage 142c and the gas phase side valve body 161 is displaced to the fully open position of the gas phase refrigerant passage 141f. A control pulse is output to the actuator 182. Thereby, as shown in FIG. 5, the integrated valve 14 is switched to the second mode in which the opening degree of the gas-phase refrigerant passage 141f is fully opened while the liquid-phase refrigerant passage 142c is closed.

  On the other hand, as a result of the determination process in step S241, when it is determined that the previous operation mode is not an operation mode other than the first heating mode, the transient state in which the load state of the compressor 11 shifts to a predetermined high load state. It is determined whether it is a period (S245).

  In the present embodiment, the difference between the target rotational speed output to the electric motor of the compressor 11 and the current rotational speed of the electric motor (= target rotational speed−current rotational speed) is not less than a predetermined reference value. When it becomes, it determines with it being the transition period in which the load state of the compressor 11 transfers to a high load state.

  On the other hand, when the difference between the target rotational speed output to the electric motor of the compressor 11 and the current rotational speed of the electric motor is smaller than the reference value, the load state of the compressor 11 transitions to a high load state. It is determined that it is not the period.

  As a result, when it is determined that the load state of the compressor 11 is in a transitional period in which the compressor 11 shifts to a predetermined high load state, the liquid inflow condition is satisfied, and the compressor 11 is passed through the intermediate pressure refrigerant passage 15. Liquid phase refrigerant may be sucked.

  For this reason, the air-conditioning control device 40 switches the operation mode of the integrated valve 14 to the third mode, and executes the injection suppression operation until a predetermined return condition is satisfied (S242, S243).

  On the other hand, when it is determined that the load state of the compressor 11 is not a transitional period in which the compressor 11 shifts to a predetermined high load state, the pressure difference before and after the fixed throttle 17 is expanded to a level at which all the liquid-phase refrigerant can flow through the fixed throttle 17. it seems to do. For this reason, the air-conditioning control apparatus 40 switches the operation mode of the integrated valve 14 to the second mode, and executes the injection operation (S244).

  Subsequently, it is determined whether or not a process end condition for ending the first heating control process is satisfied (S246). When it is determined that the process end condition is satisfied, the first heating control process is ended, and the process end condition is determined. When it is determined that is not established, the process returns to step S241. The process end condition is a condition that is satisfied when the operation switch of the vehicle air conditioner 1 is turned off when the operation mode is switched.

  As described above, in the first heating mode of the present embodiment, when there is a high possibility that the liquid refrigerant does not completely flow through the fixed throttle 17, the operation mode of the integrated valve 14 is changed to the fully open gas-phase refrigerant passage 141f. The mode is switched to the third mode in which the passage opening is smaller than the state.

  According to this, it becomes possible to suppress the liquid phase refrigerant from flowing into the intermediate pressure port 11 c side of the compressor 11 through the intermediate pressure refrigerant passage 15. As a result, it is possible to suppress the occurrence of the malfunction of the compressor 11 due to the liquid phase refrigerant flowing in. In the present embodiment, the determination process in steps S241 and S245 in FIG. 17 constitutes a success / failure determination unit that determines whether or not the liquid inflow condition is satisfied.

(C) Second heating control process (second heating mode)
In the second heating control process, the air-conditioning control device 40 throttles the high stage side expansion valve 13 (a state that exerts a pressure reducing action), the low stage side expansion valve 22 is fully closed, and the bypass on-off valve 251 is opened. State.

  Further, the air-conditioning control device 40 controls the electric actuator 182 so that the gas phase side valve body 161 is displaced to the fully closed position of the gas phase refrigerant passage 141f and the liquid phase side valve body 162 is displaced to the fully open position of the liquid phase refrigerant passage 142c. In contrast, a control pulse is output. Thereby, as shown in FIG. 4, the integrated valve 14 is switched to the first mode in which the opening degree of the liquid-phase refrigerant passage 142c is fully opened while the gas-phase refrigerant passage 141f is closed.

  Therefore, in the heat pump cycle 10, as shown by the solid line arrow in FIG.

  With the configuration of the refrigerant circuit, the air conditioning control device 40 determines the operating state of each control device connected to the output side of the air conditioning control device 40 based on the target blowing temperature TAO and the detection signal of the sensor group 41. In the second heating mode, the control signal output to the high stage side expansion valve 13 flows out from the indoor condenser 12 so that the refrigerant pressure in the indoor condenser 12 becomes a predetermined target high pressure. The degree of supercooling of the refrigerant is determined to be a predetermined target degree of supercooling. For the control signal output to the servo motor of the air mix door 34, the air mix door 34 closes the bypass passage 35, and the entire flow rate of the blown air after passing through the indoor evaporator 23 passes through the indoor condenser 12. To be determined.

Therefore, in the heat pump cycle 10 in the second heating mode, as shown in the Mollier diagram of FIG. 18, the high-pressure refrigerant discharged from the discharge port 11 b of the compressor 11 (point a _{13 in} FIG. 18) goes to the indoor condenser 12. Inflow. The refrigerant flowing into the indoor condenser 12, the blower 32 is blown from the radiating heat cabin blown air by heat exchange through the interior evaporator 23 (a ₁₃ point of FIG. 18 → b ₁₃ points). Thereby, vehicle interior blowing air is heated.

The refrigerant flowing from the indoor condenser 12, is isenthalpic depressurize expansion in the high stage side expansion valve 13 which has a stop state until a low-pressure refrigerant (b ₁₃ points in FIG. 18 → c ₁₃ points), It flows into the gas-liquid separation space 141b of the integrated valve 14. The refrigerant that has flowed into the gas-liquid separation space 141b flows out of the liquid-phase side outlet 142b through the liquid-phase refrigerant passage 142c without flowing out of the gas-phase side outlet 141e, as in the cooling operation mode.

Low-pressure refrigerant flowing from the liquid phase side outlet 142b flows into the outdoor heat exchanger 20, and outside air heat exchanger that has been blown from the blower fan 21 absorbs heat (c ₁₃ points in FIG. 18 → d ₁₃ points). The refrigerant flowing out of the outdoor heat exchanger 20 flows into the accumulator 24 via the bypass passage 25 and is separated into gas and liquid because the bypass on-off valve 251 is in the open state. The separated gas-phase refrigerant is sucked from the suction port 11a of the compressor 11 _{(e 13} points in FIG. 18).

  As described above, in the second heating mode, the heat of the refrigerant discharged from the compressor 11 by the indoor condenser 12 is dissipated to the vehicle interior blown air, and the heated room blown air is blown into the vehicle interior. it can. Thereby, heating of a vehicle interior is realizable.

  Here, the effect of executing the second heating mode when the heating load is relatively low, such as when the outside air temperature is high, is described with respect to the first heating mode. In the first heating mode, since the gas injection cycle can be configured as described above, the COP of the heat pump cycle 10 as a whole can be improved.

  That is, theoretically, if the rotation speed of the compressor 11 is the same, the first heating mode can exhibit higher heating performance than that in the second heating mode. In other words, the rotation speed (refrigerant discharge capacity) of the compressor 11 necessary for exhibiting the same heating performance is lower in the first heating mode than in the second heating mode.

  However, the compression mechanism has a maximum efficiency rotational speed at which the compression efficiency is maximized (peak), and the compression efficiency is greatly reduced when the rotational speed is lower than the maximum efficient rotational speed. For this reason, when the compressor 11 is operated at a rotation speed lower than the maximum efficiency rotation speed when the heating load is relatively low, the COP may decrease in the first heating mode.

  Therefore, in the present embodiment, when the outside air temperature is high and the heating load is low during execution of the first heating mode, the mode is switched to the second heating mode, and the outside air temperature becomes low during the execution of the second heating mode. When the load becomes high, the mode is switched to the first heating mode.

  Thereby, the operation mode which can exhibit high COP can be selected among 1st heating mode and 2nd heating mode. Therefore, even when the rotation speed of the compressor 11 becomes equal to or lower than the reference rotation speed during the execution of the first heating mode, the COP of the heat pump cycle 10 as a whole is improved by switching to the second heating mode. Can be made.

(D) Dehumidification heating control processing (dehumidification heating operation mode)
In the dehumidifying and heating control process, the air conditioning control device 40 brings the expansion valves 13 and 22 into a fully open state or a throttle state, and closes the bypass opening and closing valve 251.

  Further, the air-conditioning control device 40 controls the electric actuator 182 so that the gas phase side valve body 161 is displaced to the fully closed position of the gas phase refrigerant passage 141f and the liquid phase side valve body 162 is displaced to the fully open position of the liquid phase refrigerant passage 142c. In contrast, a control pulse is output. Thereby, as shown in FIG. 4, the integrated valve 14 is switched to the first mode in which the opening degree of the liquid-phase refrigerant passage 142c is fully opened while the gas-phase refrigerant passage 141f is closed.

  Therefore, in the heat pump cycle 10, the refrigerant circuit is switched to the same refrigerant circuit as that in the cooling operation mode, that is, the refrigerant circuit through which the refrigerant flows as shown by the solid line arrow in FIG.

  With the configuration of the refrigerant circuit, the air conditioning control device 40 determines the operating state of each control device connected to the output side of the air conditioning control device 40 based on the target blowing temperature TAO and the detection signal of the sensor group 41.

  For example, for the control signal output to the servo motor of the air mix door 34, the air mix door 34 closes the bypass passage 35, and the entire flow rate of the blown air after passing through the indoor evaporator 23 passes through the indoor condenser 12. To be determined. Furthermore, in the dehumidifying and heating mode of the present embodiment, the throttle openings of the high stage side expansion valve 13 and the low stage side expansion valve 22 are changed according to the temperature difference between the set temperature and the outside air temperature. Specifically, the four stages of dehumidifying and heating operation modes of the first to fourth dehumidifying and heating modes are executed as the target blowing temperature TAO increases.

(D-1) 1st dehumidification heating mode In 1st dehumidification heating mode, the high stage side expansion valve 13 is made into a full open state, and the low stage side expansion valve 22 is made into a throttle state. Therefore, although the cycle configuration is exactly the same as that in the cooling operation mode, the air mix door 34 fully opens the air passage of the indoor condenser 12, so the state of the refrigerant circulating in the cycle is shown by the Mollier line in FIG. It changes as shown in the figure.

That is, as shown in FIG. 19, the high-pressure refrigerant discharged from the discharge port 11 b of the compressor 11 (point a _{14 in} FIG. 19) flows into the indoor condenser 12 and is cooled by the indoor evaporator 23. The heat is exchanged with the dehumidified vehicle interior air to dissipate heat ( ₁₄ points in FIG. 19 → ₁₄ points in b1). Thereby, vehicle interior blowing air is heated.

The refrigerant that has flowed out of the indoor condenser 12 flows in the order of the high-stage expansion valve 13 → the integrated valve 14 and flows into the outdoor heat exchanger 20 in the same manner as in the cooling operation mode. The high-pressure refrigerant flowing into the outdoor heat exchanger 20 exchanges heat with the outside air blown from the blower fan 21 to dissipate heat (b1 ₁₄ points → b2 ₁₄ points in FIG. 19). The subsequent operation is the same as in the cooling operation mode.

  As described above, in the first dehumidifying / heating mode, the vehicle interior blown air cooled and dehumidified by the indoor evaporator 23 can be heated by the indoor condenser 12 and blown out into the vehicle interior. Thereby, dehumidification heating of a vehicle interior is realizable.

(D-2) Second Dehumidifying Heating Mode Next, when the target blowing temperature TAO becomes higher than a predetermined first reference temperature during execution of the first dehumidifying heating mode, the second dehumidifying heating mode is set. Executed. In the second dehumidifying and heating mode, the high stage side expansion valve 13 is set to the throttled state, and the throttle opening degree of the low stage side expansion valve 22 is set to the throttled state that is increased compared to the first dehumidifying and heating mode. Therefore, in the second dehumidifying and heating mode, the state of the refrigerant circulating in the cycle changes as shown in the Mollier diagram of FIG.

That is, as shown in FIG. 20, the high-pressure refrigerant discharged from the discharge port 11b of the compressor 11 (a ₁₅ point in FIG. 20), as in the first dehumidification and heating mode, and flows into indoor condenser 12, Heat is exchanged with the air blown into the passenger compartment cooled and dehumidified by the indoor evaporator 23 to dissipate heat ( ₁₅ points in FIG. 20 → ₁₅ points in b1). Thereby, vehicle interior blowing air is heated.

The refrigerant that has flowed out of the indoor condenser 12 is decompressed in an enthalpy manner until it becomes an intermediate-pressure refrigerant having a temperature higher than the outside air temperature by the high-stage expansion valve 13 that is in a throttled state (b1 in FIG. 20 at ₁₅ points). → b2 ₁₅ points). The intermediate pressure refrigerant decompressed by the high stage side expansion valve 13 flows into the outdoor heat exchanger 20 through the integrated valve 14 as in the cooling operation mode.

And the intermediate pressure refrigerant | coolant which flowed into the outdoor heat exchanger 20 heat-exchanges with the external air ventilated from the ventilation fan 21, and thermally radiates (b2 ₁₅ point-> b3 ₁₅ point of FIG. 20). The subsequent operation is the same as in the cooling operation mode.

  As described above, in the second dehumidifying and heating mode, as in the first dehumidifying and heating mode, the vehicle interior blown air that has been cooled and dehumidified by the indoor evaporator 23 is heated by the indoor condenser 12 into the vehicle interior. Can be blown out. Thereby, dehumidification heating of a vehicle interior is realizable.

  At this time, in the second dehumidifying and heating mode, since the high stage side expansion valve 13 is in the throttle state, the temperature of the refrigerant flowing into the outdoor heat exchanger 20 can be lowered compared to the first dehumidifying and heating mode. Therefore, the temperature difference between the temperature of the refrigerant in the outdoor heat exchanger 20 and the outside air temperature can be reduced, and the amount of heat released from the refrigerant in the outdoor heat exchanger 20 can be reduced.

  As a result, it is possible to increase the refrigerant pressure in the indoor condenser 12 without increasing the refrigerant circulation flow rate that circulates the cycle with respect to the first dehumidifying and heating mode, and from the indoor condenser 12 than in the first dehumidifying and heating mode. The temperature to be blown out can be increased.

(D-3) Third Dehumidifying Heating Mode Next, during the execution of the second dehumidifying heating mode, the target blowing temperature TAO becomes higher than a predetermined second reference temperature (second reference temperature> first reference temperature). In this case, the third dehumidifying heating mode is executed. In the third dehumidifying and heating mode, the throttle opening of the high stage side expansion valve 13 is set to a throttled state smaller than that in the second dehumidifying and heating mode, and the throttle opening of the low stage side expansion valve 22 is set to be lower than that in the second dehumidifying and heating mode. increase. Accordingly, in the third dehumidifying heating mode, the state of the refrigerant circulating in the cycle changes as shown in the Mollier diagram of FIG.

That is, as shown in FIG. 21, the high-pressure refrigerant discharged from the discharge port 11b of the compressor 11 (point a _{16 in} FIG. 21) flows into the indoor condenser 12 as in the first and second dehumidifying heating modes. Then, heat is exchanged with the air blown into the passenger compartment that has been cooled and dehumidified by the indoor evaporator 23 to dissipate heat (a ₁₆ points → b ₁₆ points in FIG. 21). Thereby, vehicle interior blowing air is heated.

The refrigerant that has flowed out of the indoor condenser 12 is decompressed in an enthalpy manner until it becomes an intermediate pressure refrigerant having a temperature lower than the outside air temperature by the high-stage expansion valve 13 in a throttled state (b ₁₆ points in FIG. 21). → c1 ₁₆ points). The intermediate pressure refrigerant decompressed by the high stage side expansion valve 13 flows into the outdoor heat exchanger 20 through the integrated valve 14 as in the cooling operation mode.

The intermediate-pressure refrigerant that has flowed into the outdoor heat exchanger 20 absorbs heat by exchanging heat with the outside air blown from the blower fan 21 (c1 ₁₆ points → c2 ₁₆ points in FIG. 21). Furthermore, the refrigerant that has flowed out of the outdoor heat exchanger 20 is decompressed in an isoenthalpy manner by the low-stage expansion valve 22 (c2 ₁₆ points → c3 ₁₆ points in FIG. 21), and flows into the indoor evaporator 23. The subsequent operation is the same as in the cooling operation mode.

  As described above, in the third dehumidifying and heating mode, similarly to the first and second dehumidifying and heating modes, the vehicle interior blown air cooled by the indoor evaporator 23 and dehumidified is heated by the indoor condenser 12. Can be blown into the passenger compartment. Thereby, dehumidification heating of a vehicle interior is realizable.

  At this time, in the third dehumidifying and heating mode, the outdoor heat exchanger 20 is caused to act as an evaporator by reducing the throttle opening of the high stage side expansion valve 13. The heat absorption amount of the refrigerant in the outdoor heat exchanger 20 can be increased.

  As a result, the suction refrigerant density of the compressor 11 can be increased with respect to the second dehumidifying heating mode, and the refrigerant pressure in the indoor condenser 12 can be increased without increasing the compressor rotation speed. The temperature blown out from the indoor condenser 12 can be increased more than in the dehumidifying and heating mode.

(D-4) Fourth Dehumidifying Heating Mode Next, during the execution of the third dehumidifying heating mode, the target outlet temperature TAO becomes higher than a predetermined third reference temperature (third reference temperature> second reference temperature). In this case, the fourth dehumidifying and heating mode is executed. In the fourth dehumidifying and heating mode, the throttle opening of the high stage side expansion valve 13 is set to a throttled state smaller than that in the third dehumidifying and heating mode, and the low stage side expansion valve 22 is fully opened. Therefore, in the fourth dehumidifying heating mode, the state of the refrigerant circulating in the cycle changes as shown in the Mollier diagram of FIG.

That is, as shown in FIG. 22, (a ₁₇ point in FIG. 22) the high-pressure refrigerant discharged from the discharge port 11b of the compressor 11, first, similarly to the second dehumidification and heating mode, flows into indoor condenser 12 Then, heat is exchanged with the air blown into the passenger compartment that has been cooled and dehumidified by the indoor evaporator 23 to dissipate heat (a point _{17 in} FIG. 22 → b point ₁₇ ). Thereby, vehicle interior blowing air is heated.

The refrigerant that has flowed out of the indoor condenser 12 is decompressed in an enthalpy manner until it becomes a low-pressure refrigerant having a temperature lower than the outside air temperature by the high-stage expansion valve 13 that is in the throttled state (b ₁₇ point in FIG. 22 → c1 ₁₇ points). The low-pressure refrigerant decompressed by the high stage side expansion valve 13 flows into the outdoor heat exchanger 20 through the integrated valve 14 as in the cooling operation mode.

And the low-pressure refrigerant | coolant which flowed into the outdoor heat exchanger 20 heat-exchanges with the external air ventilated from the ventilation fan 21, and absorbs heat (c1 ₁₇ point-> c2 ₁₇ point of FIG. 22). Furthermore, the refrigerant that has flowed out of the outdoor heat exchanger 20 flows into the indoor evaporator 23 without being depressurized because the low-stage expansion valve 22 is fully open. The subsequent operation is the same as in the cooling operation mode.

  As described above, in the fourth dehumidifying and heating mode, the vehicle interior blown air cooled and dehumidified by the indoor evaporator 23 is heated by the indoor condenser 12 as in the first to third dehumidifying and heating modes. Can be blown into the passenger compartment. Thereby, dehumidification heating of a vehicle interior is realizable.

  At this time, in the fourth dehumidifying and heating mode, the outdoor heat exchanger 20 is caused to act as an evaporator, and the throttle opening degree of the higher stage side expansion valve 13 is set to be higher than that in the third dehumidifying and heating mode. Since it is reduced, the refrigerant evaporation temperature in the outdoor heat exchanger 20 can be lowered. Therefore, the temperature difference between the refrigerant temperature and the outside air temperature in the outdoor heat exchanger 20 can be expanded more than in the third dehumidifying and heating mode, and the heat absorption amount of the refrigerant in the indoor condenser 12 can be increased.

  As a result, the suction refrigerant density of the compressor 11 can be increased with respect to the third dehumidifying heating mode, and the refrigerant pressure in the indoor condenser 12 can be increased without increasing the rotational speed. The temperature blown out from the indoor condenser 12 can be increased more than in the dehumidifying and heating mode.

  In the vehicle air conditioner 1 of the present embodiment described above, various cycle configurations are realized by switching the refrigerant circuit of the heat pump cycle 10 as described above, and appropriate cooling, heating, and dehumidifying heating in the vehicle interior are achieved. realizable.

  Furthermore, in the vehicle air conditioner 1 applied to the electric vehicle as in the present embodiment, the waste heat of the engine cannot be used for heating the vehicle interior as in a vehicle equipped with an internal combustion engine (engine). Therefore, it is extremely effective that a high COP can be exhibited regardless of the heating load in the heating operation mode as in the heat pump cycle 10 of the present embodiment.

  Moreover, in this embodiment, since the integrated valve 14 which integrally comprised a part of component apparatus required in order to function the heat pump cycle 10 as a gas injection cycle is employ | adopted, the heat pump cycle which comprises a gas injection cycle Ten cycle configurations can be simplified. As a result, it is possible to improve the mountability of the heat pump cycle 10 on the mounting object.

  Further, in the integrated valve 14 of the present embodiment, the single driving means 18 performs gas-liquid separation of the refrigerant, opening and closing of the liquid-phase refrigerant passage 142c and the gas-phase refrigerant passage 141f, and decompression of the liquid-phase refrigerant. Can do. According to this, the heat pump cycle 10 that can be switched to the gas injection cycle can be realized with a simple cycle configuration.

  Specifically, by setting the passage opening degree of the liquid-phase refrigerant passage 142c to a fully open state with the gas-phase refrigerant passage 141f closed, all of the refrigerant flowing out of the gas-liquid separation space 141b It is possible to switch to a refrigerant circuit that flows out from the outlet 142b.

  Further, the liquid-phase refrigerant separated in the gas-liquid separation space 141b is decompressed by the fixed throttle 17 by setting the passage opening degree of the gas-phase refrigerant passage 141f to a fully open state with the liquid-phase refrigerant passage 142c closed. At the same time, the refrigerant circuit can be switched to allow the gas-phase refrigerant to flow out to the intermediate pressure port 11c side of the compressor 11.

  In particular, the integrated valve 14 of the present embodiment can set the passage opening of the gas-phase refrigerant passage 141f to a smaller passage opening than the fully opened state with the liquid-phase refrigerant passage 142c closed.

  According to this, when the liquid refrigerant cannot flow through the fixed throttle 17, by setting the passage opening of the gas-phase refrigerant passage 141f to a passage opening smaller than the fully opened state, the intermediate pressure refrigerant passage 15 is Therefore, it is possible to suppress the liquid-phase refrigerant from flowing into the intermediate pressure port 11c side of the compressor 11. As a result, it is possible to suppress the occurrence of the malfunction of the compressor 11 due to the liquid phase refrigerant flowing in.

  Therefore, according to the integrated valve 14 of the present embodiment, the liquid phase refrigerant flows into the compressor 11 through the intermediate pressure refrigerant passage 15 while simplifying the cycle configuration of the heat pump cycle 10 that can be switched to the gas injection cycle. Can be suppressed.

  Further, in the drive system for the integrated valve 14 of the present embodiment, the gas-phase refrigerant passage is in a state where the liquid-phase refrigerant passage 142c is closed under the condition that the inflow of the liquid-phase refrigerant into the intermediate pressure port 11c of the compressor 11 is assumed. The passage opening of 141f is switched to a passage opening smaller than the fully opened state.

  According to this, the inflow of the liquid phase refrigerant into the gas phase refrigerant passage 141f is suppressed, and the liquid phase refrigerant is effectively prevented from flowing into the compressor 11 through the intermediate pressure refrigerant passage 15. Can do.

  Moreover, the integrated valve 14 of this embodiment is displaced to the position of each valve body 161, 162 by the simple drive means 18 provided with the rod 181, the electric actuator 182, and the elastic member 183, and the operation mode of the integrated valve 14 is carried out. Can be switched to three modes such as the first to third modes. According to this, simplification of the integrated valve 14 which can suppress that a liquid phase refrigerant | coolant flows in into the intermediate pressure port 11c side of the compressor 11 via the intermediate pressure refrigerant path 15 can be achieved.

  Moreover, the integrated valve 14 of this embodiment covers a part of rod 181 with the cylindrical part 162b of the liquid phase side valve body 162, and the first and third seal members 162c, 161b are provided on the valve bodies 161, 162, respectively. It is set as the structure which provides.

  According to this, when the gas-phase refrigerant passage 141f is closed by the gas-phase side valve body 161, the liquid-phase refrigerant enters the gas-phase refrigerant passage 141f through the gaps between the rod 181 and the valve bodies 161 and 162. Inflow can be suppressed.

  Furthermore, a third seal member 161b is provided in a portion of the gas phase side valve body 161 that contacts the cylindrical portion 162b, not in the gap between the rod 181 and each valve body 161, 162, and the liquid phase side valve body 162 is provided. A first seal member 162c is provided at a portion in contact with the second protrusion 181b.

  According to this, since each sealing member 162c, 161b does not contact the rod 181, without increasing the sliding resistance when each valve body 161, 162 is displaced, the rod 181 and each valve body 161, 162 between It can suppress that a refrigerant | coolant leaks through the clearance gap between them.

  Further, in the present embodiment, the area ratio of the area Sb2 of the gas phase side valve body 161 to the opening area Sb1 of the gas phase side inflow portion 141d is set to be the ratio of the liquid phase side valve body 162 to the opening area Sa1 of the liquid phase side inflow portion 142a. The area ratio of the area Sa2 is increased (Sb2 / Sb1> Sa2 / Sa1).

  Thus, by expanding the area Sb2 of the gas-phase side valve element 161 to be larger than the opening area Sb1 of the gas-phase-side inflow portion 141d, the gas-phase side valve element 161 can be opened when the gas-phase refrigerant passage 141f is opened. It can be made to function as a shutter which suppresses scattering of the liquid phase refrigerant to the phase refrigerant passage 141f side. Thereby, it can suppress that the liquid phase refrigerant | coolant isolate | separated in the gas-liquid separation space 141b flows in into the gaseous-phase refrigerant path 141f, without providing a dedicated member.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, In the range described in the claim, it can change suitably. For example, various modifications are possible as follows.

  (1) In the above-described embodiment, the example in which the heat pump cycle 10 is applied to the vehicle air conditioner 1 for an electric vehicle has been described. However, the heat pump cycle 10 travels from an engine (internal combustion engine) and a traveling electric motor, for example. It is effective when applied to a vehicle in which engine waste heat may become insufficient as a heat source for heating, such as a hybrid vehicle that obtains a driving force for use.

  Further, the heat pump cycle 10 may be applied to, for example, a stationary air conditioner, a cold / hot storage, a liquid heating device, and the like. Further, when applied to a liquid heating device, a liquid-refrigerant heat exchanger is adopted as a use-side heat exchanger, and a liquid pump or flow rate adjustment for adjusting the flow rate of liquid flowing into the liquid-refrigerant heat exchanger as a flow rate adjusting means. A valve may be employed.

  (2) In the above-described embodiment, examples in which various operation modes are realized by switching the refrigerant circuit of the heat pump cycle 10 using the expansion valves 13 and 22, the integrated valve 14, the bypass on-off valve 251, and the like have been described. However, it is not limited to this.

  The heat pump cycle 10 may be configured to be able to switch between a gas injection cycle and a normal cycle other than the gas injection cycle. For example, the heat pump cycle 10 may have a configuration in which only the heating operation mode including the first heating mode and the second heating mode can be realized, or a configuration in which only the first heating mode and the cooling operation mode can be realized. It may be. Of course, the provision of various operation modes is effective in that the temperature of the heat exchange target fluid (blast air) can be adjusted appropriately.

  (3) In the above-mentioned embodiment, although the example which switches 1st heating mode and 2nd heating mode based on external temperature was demonstrated, it is not limited to this, For example, based on the rotation speed of the compressor 11, You may make it switch between 1st heating mode and 2nd heating mode. Specifically, when the rotation speed of the compressor 11 becomes equal to or lower than the reference rotation speed (maximum efficiency rotation speed) during execution of the first heating mode, the second heating mode is switched to the second heating mode. What is necessary is just to switch to 1st heating mode, when it becomes more than the rotation speed which added predetermined amount predetermined with respect to the reference | standard rotation speed inside. This also makes it possible to select an operation mode in which a high COP can be exhibited among the first heating mode and the second heating mode.

  (4) In the above-described embodiment, an example of adopting a substantially rectangular tube appearance as the shape of the body 140 has been described. However, the shape of the body 140 is not limited to this, and the body 140 is mounted on a mounting object. You may employ | adopt the shape suitable for a mounting space. According to this, the mounting property to the mounting target object as the heat pump cycle 10 whole can be improved further.

  (5) From the viewpoint of reducing the size of the integrated valve 14 as a whole as in the above-described embodiment, the internal volume of the gas-liquid separation space 141b is set to a volume that cannot substantially store surplus refrigerant. However, the present invention is not limited to this. That is, the internal volume of the gas-liquid separation space 141b may be set to a volume that can store excess refrigerant.

  (6) In the above-described embodiment, an example in which the gas-liquid separation space 141b constitutes a centrifugal separation type gas-liquid separation means has been described. However, the present invention is not limited to this, and according to the required gas-liquid separation performance, gravity A configuration in which gas-liquid separation is performed by the action of the above or the action of surface tension may be employed.

  (7) As in the above-described embodiment, the gas-phase side valve element 161 is allowed to function as a shutter that suppresses the scattering of the liquid-phase refrigerant toward the gas-phase refrigerant passage 141f when the gas-phase refrigerant passage 141f is opened. Although desirable, it is not limited to this. For example, a shutter member is added between the gas phase side inflow portion 141d and the liquid phase side inflow portion 142a to suppress scattering of the liquid phase refrigerant to the gas phase refrigerant passage 141f when the gas phase refrigerant passage 141f is opened. May be.

  (8) In the above-described embodiment, the example in which the driving unit 18 is configured by the rod 181, the electric actuator 182, and the elastic member 183 has been described, but the present invention is not limited to this. The drive unit 18 may be configured by other mechanisms as long as the operation mode of the integrated valve 14 can be switched to three modes such as the first to third modes illustrated in FIG. 10.

  (9) As in the above-described embodiment, the first and third seal members 162c and 161b arranged in a state of being separated from the rod 181 suppress refrigerant leakage from the gaps between the valve bodies 161 and the rod 181. However, the present invention is not limited to this. When the gap between each valve element 161 and the rod 181 is small and refrigerant leakage hardly causes a problem, the seal members 162c and 161b may be omitted.

  (10) In the above-described embodiment, the example in which the stepping motor is employed as the electric actuator 182 of the driving unit 18 that displaces the valve unit 16 has been described. However, the present invention is not limited thereto, and for example, a servo motor is employed as the electric actuator 182. May be.

  (11) As in the above-described embodiment, in the initial stage in which the operation mode of the vehicle air conditioner 1 is switched to the first heating mode, and in the transition period in which the load state of the compressor 11 shifts to the high load state, the integrated valve 14 Although it is desirable to switch the operation mode to the third mode, the present invention is not limited to this. For example, only when the operation mode of the vehicle air conditioner 1 is switched to the first heating mode, the operation mode of the integrated valve 14 is switched to the third mode, or the load state of the compressor 11 transitions to the high load state. Only in the period, the operation mode of the integrated valve 14 may be switched to the third mode.

  (12) In the above-described embodiment, the operation mode switching control process of the vehicle air conditioner 1 and the mode switching process of the integrated valve 14 have been described with reference to the flowcharts of FIGS. 11 and 17. The flowchart is merely an example, and the processing content shown in the flowchart may be realized by other processing.

  (13) In the above-described embodiment, the elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Needless to say.

  (14) In the above-described embodiment, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, it is clearly indicated that it is particularly essential and clearly specified in principle. It is not limited to the specific number except in a limited case.

  (15) In the above-described embodiment, when referring to the shape, positional relationship, etc. of the component, etc., unless specifically stated, and in principle limited to a specific shape, positional relationship, etc. The positional relationship is not limited.

140 Body 141a Refrigerant inlet 141b Gas-liquid separation space 141e Gas phase side outlet 142b Liquid phase side outlet 15 Intermediate pressure refrigerant passage 161 Gas phase side valve element 162 Liquid phase side valve element 17 Fixed throttle 18 Driving means

Claims (7)

An integrated valve applied to a heat pump cycle (10) switchable to a gas injection cycle,
Refrigerant inlet (141a) through which the refrigerant discharged from the compressor (11) of the heat pump cycle flows, gas-liquid separation space (141b) for separating the gas and liquid of the refrigerant flowing in from the refrigerant inlet, and intermediate pressure refrigerant passage (15) the gas-phase refrigerant separated in the gas-liquid separation space via the gas-phase side outlet (141e) for flowing out to the intermediate suction port (11c) side of the compressor, and the gas-liquid separation space A body (140) having a liquid-phase side outlet (142b) for allowing the separated liquid-phase refrigerant to flow out;
A gas phase side valve element (161) for changing a passage opening degree of a gas phase refrigerant path (141f) from the gas-liquid separation space to the gas phase side outlet,
A liquid phase side valve element (162) that changes the passage opening degree of the liquid phase refrigerant path (142c) from the gas-liquid separation space to the liquid phase side outlet port;
Drive means (18) for displacing both the gas phase side valve element and the liquid phase side valve element;
A fixed throttle (17) that depressurizes the refrigerant that flows out to the liquid-phase side outlet when the liquid-phase side valve element closes the liquid-phase refrigerant passage;
The driving means includes
When the gas-phase side valve element is displaced to the fully-closed position for closing the gas-phase refrigerant path, the liquid-phase side valve element is displaced to the fully-open position where the opening degree of the liquid-phase refrigerant path is fully open. Composed of
When the liquid-phase side valve element is displaced to the fully-closed position for closing the liquid-phase refrigerant passage, the opening degree of the gas-phase refrigerant passage is fully opened, and the opening degree of the gas-phase refrigerant passage is An integrated valve characterized in that it is configured to be able to be displaced to a position smaller than the fully open state. Inside the body, a liquid phase side valve seat part (142a) where the liquid phase side valve element comes in contact with and separates from each other, and a gas phase side valve seat part (141a) where the gas phase side valve body comes in contact with and separates from each other. Is formed as
Each of the liquid phase side valve element and the gas phase side valve element is disposed between the liquid phase side valve seat part and the gas phase side valve seat part,
The driving means includes
A rod (181) disposed so as to penetrate both the gas phase side valve body and the liquid phase side valve body;
An electric actuator (182) for driving the rod in the axial direction;
The gas phase side valve element is disposed between the liquid phase side valve element and applies a load to the gas phase side valve element in a direction in contact with the gas phase side valve seat part, and the liquid phase side An elastic member (183) for applying a load to the side valve body in a direction in contact with the liquid phase side valve seat portion,
When the gas phase side valve element is displaced to a position where the gas phase refrigerant passage is opened, the rod contacts the gas phase side valve element and contacts the gas phase side valve element with respect to the gas phase side valve element. When the liquid phase side valve element is displaced to a position where the liquid phase refrigerant passage is opened, and the first protrusion (181a) that applies a load in a direction away from the seat part, the liquid phase side valve element is brought into contact with the liquid phase side valve element. A second projecting portion (181b) for applying a load to the liquid phase side valve body in a direction away from the liquid phase side valve seat portion,
When the first protrusion and the gas phase side valve body come into contact with each other and a load is applied to the gas phase side valve body in a direction away from the gas phase side valve seat portion, the elastic member causes The liquid phase side valve element is displaced to a position where it abuts on the liquid phase side valve seat by a load,
When the second protrusion and the liquid phase side valve body come into contact with each other and a load is applied to the liquid phase side valve body in a direction away from the liquid phase side valve seat portion, the elastic member causes 2. The integrated valve according to claim 1, wherein the gas phase side valve body is displaced to a position where the gas phase side valve seat portion comes into contact with a load. The liquid phase side valve body covers a valve portion (162a) that contacts and separates from the liquid phase side valve seat portion, and a portion of the rod that exists between the liquid phase side valve portion and the gas phase side valve body. An annular cylindrical portion (162b) provided
The gas-phase-side valve body has a first leak for suppressing a refrigerant from leaking through a gap formed between the rod and the gas-phase-side valve body at a portion in contact with the cylindrical portion. A suppression portion (161b) is provided;
The liquid-phase side valve element is a second part for suppressing the refrigerant from leaking through a gap formed between the rod and the liquid-phase side valve element at a portion in contact with the second protrusion. The integrated valve according to claim 2, wherein a leakage suppression unit (162 c) is provided.   The area ratio (Sb2 / Sb1) of the area (Sb2) of the part facing the liquid phase side valve seat part in the gas phase side valve body to the opening area (Sb1) in the gas phase side valve seat part is the liquid phase. That the area ratio (Sa2 / Sa1) of the area (Sa2) of the part facing the liquid phase side valve seat part in the liquid phase side valve element to the opening area (Sa1) in the side valve seat part is larger. The integrated valve according to claim 2 or 3, characterized in that: Integrated valve (14) according to any one of claims 1 to 4,
Controlling the driving means to change the operation mode of the integrated valve into a first mode in which the opening degree of the liquid-phase refrigerant passage is fully opened while the gas-phase refrigerant passage is closed; A second mode in which the opening of the gas-phase refrigerant passage is fully opened in the closed state; and a passage opening in which the opening of the gas-phase refrigerant passage is smaller than that in the fully-open state in the state of closing the liquid-phase refrigerant passage. Drive control means (40a) for switching to the third mode,
The drive system is characterized in that the operation mode of the integrated valve is switched to the third mode when a liquid inflow condition for allowing the liquid phase refrigerant to flow into the intermediate pressure refrigerant passage is satisfied.   The liquid inflow condition is determined when the operation mode of the heat pump cycle is switched to an injection mode in which the gas-phase refrigerant flows into the intermediate suction side of the compressor via the intermediate pressure refrigerant passage, or the injection 6. The drive system according to claim 5, wherein the drive system is a condition that is satisfied in a transition period in which the load state of the compressor shifts to a predetermined high load state during the mode.   The drive system according to claim 5 or 6, wherein the drive control means switches to the second mode when a predetermined return condition is satisfied after switching to the third mode.

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