JP6934844B2 - Vehicle air conditioner - Google Patents

Description

The present invention relates to a vehicle air conditioner provided with a heat pump cycle having a heating or dehumidifying heating function, and more particularly to a vehicle air conditioner provided with a strainer for capturing foreign matter in a refrigerant on a cycle path.

In the refrigeration cycle in which the refrigerant is circulated, foreign matter (contamination) is generated due to deterioration of the refrigerant and lubricating oil, corrosion of each component of the refrigeration cycle, and wear of sliding parts such as compressors. , There is a problem that it is mixed in the refrigerant.

Therefore, in order to capture such foreign substances in the refrigerant, for example, the configuration shown in Patent Document 1 below has been proposed.
This is provided on the suction side of the compressor of the refrigeration cycle, and a strainer is provided on the accumulator that separates the refrigerant flowing out of the evaporator into gas and liquid and returns the separated gas refrigerant to the compressor. Is provided with a mesh-like filter portion for capturing foreign matter (contamination) outside the oil return hole provided in the middle of the refrigerant outflow pipe. As a result, it is possible to suppress the generation of unintended abnormal noise and seizure of the compressor due to foreign matter being mixed in the refrigerant sucked into the compressor.

By the way, in recent years, instead of a refrigerating cycle having only a cooling function, a heat pump cycle having a heating or dehumidifying heating function is often used.
For example, as shown in FIG. 9, a compressor 10, a first heat exchanger 2 arranged in an air conditioning unit 1 and whose ventilation amount is adjusted by a damper 9, a first expansion device 11, and outside air. The vehicle interior heat exchanger 4 capable of exchanging heat with the heat exchanger 4, the second expansion device 14, and the second expansion device 14 are arranged in the air conditioning unit 1 and are arranged on the upstream side in the air conditioning unit 2 with respect to the first heat exchanger 2. The second heat exchanger 3 and the accumulator 12 are connected in a loop in at least this order, and the refrigerant flow path between the first heat exchanger 2 and the first expansion device 11 and the vehicle interior heat exchanger are connected. The refrigerant flow path between the 4 and the second expansion device 14 is connected via the first bypass flow path 16 provided with the first on-off valve 15, and the vehicle interior heat exchanger 4 and the second A second on-off valve 19 for blocking backflow is provided on the upstream side of the merging portion (A) with the first bypass flow path 16 in the refrigerant flow path between the expansion device 14 and the vehicle interior heat exchanger. A second bypass flow provided with a third on-off valve 17 is provided between the refrigerant flow path between the 4 and the second on-off valve 19 and the refrigerant flow path between the second heat exchanger 3 and the accumulator 12. A heat pump cycle connected via a path 18 has been proposed (see Patent Document 2).

Even in such a heat pump cycle, by adopting the accumulator 12 having the strainer 12c as shown in Patent Document 1, it is possible to prevent foreign matter from entering the compressor 10 and avoid the generation of unintended abnormal noise and seizure. It becomes possible.

JP-A-2009-139004 International release WO 2013/035130

However, in the above-mentioned heat pump cycle, the configuration is complicated because there are many control valves and cycle components and the piping is complicated as compared with the refrigeration cycle having only the cooling function. That is, there is a concern that the number of places where foreign matter is generated will increase and the amount of foreign matter will also increase. Therefore, in the configuration in which foreign matter is captured by the accumulator provided with the strainer described above, it is effective in preventing the inflow of foreign matter into the compressor to protect the compressor, but the accumulator from the discharge port of the compressor It is not possible to capture foreign matter flowing in the path leading to the inflow side.
In particular, in the throttle portion of the expansion device having a small passage area, there is a concern that foreign matter tends to accumulate and the desired valve opening cannot be obtained.

Therefore, in order to eliminate such inconvenience, in the cycle configuration shown in FIG. 9, on the refrigerant path on the upstream side of the first expansion device 11 and the second expansion device 14, that is, the first heat exchanger. It is also conceivable to dispose a strainer 20 (indicated by a broken line) that captures foreign matter in the refrigerant on the downstream side of No. 2 and on the upstream side of the branch portion C where the first bypass flow path 16 branches.
According to such a configuration, the strainer 20 is arranged on the upstream side of any of the expansion devices (first expansion device 11, second expansion device 14), and any operation of cooling, heating, and dehumidifying heating is performed. Since the refrigerant always flows through the strainer 20 even when the mode is selected, it can be expected to effectively prevent foreign matter from accumulating on the throttle portion of each expansion device.

However, in the configuration in which the strainer 20 is arranged on the downstream side of the first heat exchanger 2 and on the upstream side of the branch portion C where the first bypass flow path 16 branches, the refrigerant flowing out from the first heat exchanger 2 Is often in a gas phase state, and the flow velocity of the refrigerant becomes relatively high, so that there is a disadvantage that the strainer 20 significantly increases the passage resistance.
Further, a heat exchanger (external heat exchanger 4) arranged on the downstream side of the strainer 20, a branch portion C and a confluence portion A to which the first bypass flow path 16 is connected, and a second bypass. If foreign matter derived from the pipe connection portion at the branch portion D to which the flow path 18 is connected and further foreign matter derived from each pipe itself are present, the respective expansion devices (first expansion device 11, second expansion device 11 and second expansion device 11) are present. There is also the inconvenience that foreign matter accumulates on the device 14) and the strainer does not function sufficiently.

The present invention has been made in view of such circumstances, and in a vehicle air conditioner provided with a heat pump cycle capable of heating and dehumidifying and heating operation modes, the expansion device can be moved to each expansion device while suppressing an increase in passage resistance of the refrigerant path. The main issue is to provide an air conditioner for vehicles that can effectively prevent the accumulation of foreign matter.

In order to solve the above problems, the vehicle air conditioner according to the present invention includes a compressor, a first heat exchanger arranged in the air conditioner unit and the ventilation amount is adjusted by a damper, and the air conditioner unit. A second exchanger arranged upstream of the first heat exchanger in the air conditioning unit, an vehicle interior heat exchanger capable of exchanging heat with the outside air, and a refrigerant flow path are narrowed down. The compressor, the first inflator, which has a first inflator capable of closing and fully opening, a second inflator capable of narrowing and closing the refrigerant flow path, and an accumulator. The heat exchanger, the first inflator, the outdoor heat exchanger, the second inflator, the second heat exchanger, and the accumulator are connected in a loop at least in this order, and the first. A first refrigerant control unit is provided for a refrigerant flow path between the heat exchanger and the first expansion device and a refrigerant flow path between the passenger compartment outdoor heat exchanger and the second expansion device. Of the refrigerant flow paths between the vehicle interior heat exchanger and the second expansion device, which are connected via the first bypass flow path, upstream of the confluence portion with the first bypass flow path. Is provided with a second refrigerant control unit that blocks the flow of refrigerant from the merging portion to the upstream side, and the refrigerant flow path between the vehicle interior heat exchanger and the second refrigerant control unit and the second. The refrigerant flow path between the heat exchanger and the accumulator is connected via a second bypass flow path provided with a third refrigerant control unit, and the vehicle interior heat exchanger and the second expansion are connected. A strainer for catching foreign matter in the refrigerant is provided between the confluence portion and the second expansion device in the refrigerant flow path between the device and the device .
A third heat exchanger for cooling the heating element and a third expansion device capable of narrowing the refrigerant flow path are further provided, and the refrigerant between the vehicle interior heat exchanger and the second expansion device is further provided. The refrigerant flow path between the second heat exchanger and the accumulator was connected to the downstream side of the flow path from the confluence portion, and the third expansion device and the third heat exchanger were connected to each other. Connected via a branch flow path,
The strainer is characterized in that it is provided between the merging portion and the branch portion to which the branch flow path is connected in the refrigerant flow path between the vehicle interior heat exchanger and the second expansion device. It is said.

Therefore, it is a heat pump cycle that can be switched to each operation mode of cooling / heating, heating, and dehumidifying / heating, and prevents the accumulation of foreign matter on the expansion device while suppressing an increase in passage resistance.
That is, since the first expansion device can be fully opened, the mode in which the first expansion device is fully opened and the refrigerant is allowed to flow is selected during the cycle operation, so that the first expansion device is to be deposited on the first expansion device. Foreign matter is washed away. Therefore, the accumulation of foreign matter can be prevented even if the strainer is not arranged on the upstream side of the first expansion device. Further, for the second expansion device, since the strainer is arranged in the path flowing into the second expansion device, it is possible to remove the foreign matter that is about to flow into the second expansion device. Moreover, the strainer is arranged between the confluence portion to which the first bypass flow path is connected and the second expansion device in the refrigerant flow path between the vehicle interior heat exchanger and the second expansion device. Therefore, the refrigerant passing through here is rarely a gas phase refrigerant (the operation mode for passing through the second expansion device is one of an operation mode in which a gas-liquid mixture state, an operation mode in which no flow occurs, and a circulation amount. The flow rate of the refrigerant flowing through the strainer is relatively slow when looking at the entire operating period of the heat pump (because it is often in one of the operating modes in which the parts flow). Therefore, it is possible to avoid an increase in passage resistance due to the provision of the strainer.

Further, a third heat exchanger for cooling the heating element and a third expansion device capable of narrowing the refrigerant flow path are further provided, and between the vehicle interior heat exchanger and the second expansion device. The refrigerant flow path between the second heat exchanger and the accumulator on the downstream side of the confluence portion of the refrigerant flow path of the above, and the third expansion device and the third heat exchanger. In the configuration in which the strainer is connected via the connected branch flow path, the strainer has the branch flow path from the merging portion of the refrigerant flow path between the vehicle interior heat exchanger and the second expansion device. Since it is provided between the connected branch portions, it is possible to obtain the above-mentioned effect while ensuring the cooling of the heating element by the third heat exchanger regardless of the operation mode.

Here, the strainer is a connection portion between pipes on the downstream side of the confluence portion of the refrigerant flow path between the vehicle interior heat exchanger and the second expansion device, or a joint of the confluence portion. It may be arranged in the part.
In such a configuration, the strainer can be attached or replaced when the pipe is connected or replaced, so that the strainer can be easily attached.
Further, in the above-described configuration, the accumulator may be further provided with an accumulator strainer that captures the foreign matter that has flowed into the accumulator.
In such a configuration, foreign matter can be collected by the accumulator, so that the inflow of foreign matter into the compressor can be suppressed more reliably.

As described above, according to the present invention, the compressor, the first heat exchanger, the first inflator, the outdoor heat exchanger, the second inflator, the second heat exchanger, and the accumulator At least in this order, they are connected in a loop, and a first refrigerant control unit is provided between the first heat exchanger and the first expansion device and between the vehicle interior heat exchanger and the second expansion device. Of the refrigerant flow paths between the vehicle interior heat exchanger and the second expansion device, which are connected via the first bypass flow path, the merging portion is upstream from the merging portion with the first bypass flow path. A second refrigerant control unit is provided to block the flow of refrigerant from the upstream side, and between the vehicle interior heat exchanger and the second refrigerant control unit and between the second heat exchanger and the accumulator. In a vehicle air conditioner having a cycle configuration connected via a second bypass flow path provided with a third refrigerant control unit, the first expansion device is used to narrow, close, and fully open the refrigerant flow path. The expansion device is capable of capturing foreign matter in the refrigerant between the confluence portion and the second expansion device in the refrigerant flow path between the vehicle interior heat exchanger and the second expansion device. Since a strainer is provided, it is possible to prevent foreign matter from accumulating on each expansion device while suppressing an increase in passage resistance even in a heat pump cycle that can switch to each operation mode of cooling / heating, heating, and dehumidifying / heating. It becomes.

FIG. 1 shows an example of an air conditioner for a vehicle according to the present invention, FIG. 1 (a) is an overall configuration diagram thereof, and FIG. 1 (b) shows states of an expansion device, an on-off valve, and a damper for each operation mode. It is a table shown in. FIG. 2 is a cross-sectional view showing an example in which a strainer is provided at a connecting portion between pipes. FIG. 3 is a cross-sectional view showing an example in which a strainer is arranged at the joint portion of the confluence portion (A), and FIG. 3A is a cross-sectional view showing an example in which the strainer is arranged at the pipe receiving portion of the joint portion. Is a cross-sectional view showing an example in which a strainer is arranged at a connection end portion of a pipe into which a pipe protruding from a joint portion is inserted. FIG. 4 is a diagram for explaining the flow of the refrigerant in each operation mode of the vehicle air conditioner shown in FIG. 1, and FIG. 4A is a diagram for explaining the flow of the refrigerant in the cooling operation mode, FIG. 4B. Is a diagram showing the flow of the refrigerant in the heating operation mode. 5A and 5B are views for explaining the flow of the refrigerant in each operation mode of the vehicle air conditioner shown in FIG. 1, and FIG. 5A is a diagram in which the refrigerant flows using the first and second bypass flow paths. It is a figure which shows the flow of the refrigerant in the dehumidifying heating operation mode, (b) is in the dehumidifying heating operation mode which flows a refrigerant only using the 1st bypass flow path without using the 2nd bypass flow path. It is a figure which shows the flow of the refrigerant of, (c) is a figure which shows the flow of the refrigerant in the dehumidifying heating operation mode in which the refrigerant flows without using the 1st and 2nd bypass flow paths. FIG. 6 shows another example of the vehicle air conditioner according to the present invention, FIG. 6A is an overall configuration diagram thereof, and FIG. 6B is an operation of the state of the expansion device, the on-off valve, and the damper. It is a table shown for each mode. FIG. 7 is a diagram for explaining the flow of the refrigerant in each operation mode of the vehicle air conditioner shown in FIG. 6, and FIG. 7A is a diagram for explaining the flow of the refrigerant in the cooling operation mode, FIG. 7B. Is a diagram showing the flow of the refrigerant in the heating operation mode. FIG. 8 is a diagram for explaining the flow of the refrigerant in each operation mode of the vehicle air conditioner shown in FIG. 6, and FIG. 8A is a diagram in which the refrigerant flows using the first and second bypass flow paths. It is a figure which shows the flow of the refrigerant in the dehumidifying heating operation mode, (b) is in the dehumidifying heating operation mode which flows a refrigerant only using the 1st bypass flow path without using the 2nd bypass flow path. It is a figure which shows the flow of the refrigerant of, (c) is a figure which shows the flow of the refrigerant in the dehumidifying heating operation mode in which the refrigerant flows without using the 1st and 2nd bypass flow paths. FIG. 9 is a diagram showing a conventional air conditioner for vehicles.

Hereinafter, examples of the vehicle air conditioner according to the present invention will be described with reference to the drawings.

FIG. 1 shows a vehicle air conditioner according to the present invention, wherein the vehicle air conditioner is mounted on, for example, an automobile, and the first and second heat exchangers 2 and 2 are arranged in the air conditioner unit 1. 3 and an vehicle interior heat exchanger 4 which is arranged outside the air conditioning unit 1 and can exchange heat with the outside air.

An inside / outside air switching device 5 is provided on the most upstream side of the air conditioning unit 1, and the inside air inlet 5a and the outside air inlet 5b are selectively opened by the intake door 6. The inside air or outside air selectively introduced into the air conditioning unit 1 is sucked by the rotation of the blower 7 and sent to the first and second heat exchangers 2 and 3, where the heat is exchanged to obtain a desired outlet. It is supplied from 8a to 8c into the vehicle interior.

The first heat exchanger 2 is arranged on the downstream side in the air flow direction in the air conditioning unit with respect to the second heat exchanger 3, and on the upstream side in the air flow direction of the first heat exchanger 2. A damper 9 is provided. The damper 9 can be changed from the position where the air volume passing through the first heat exchanger 2 is maximum (heating position: opening 100%) to the position where it is minimum (cooling position: opening 0%). By adjusting the opening degree, the ratio of the air passing through the first heat exchanger 2 and the air bypassing the first heat exchanger 2 can be adjusted. The damper 9 is sometimes called an air mix door.

The inflow side 2a of the first heat exchanger 2 is connected to the discharge side α of the compressor 10, and the outflow side 2b of the first heat exchanger 2 is the inflow of the first expansion device (E-1) 11. It is connected to the side 11a. Further, the outflow side 3b of the second heat exchanger 3 is connected to the suction side β of the compressor 10 via the accumulator 12. The first heat exchanger 2 is sometimes called an indoor radiator or an inner capacitor. Although not shown, an electric heat generating type heating device may be arranged on the downstream side of the first heat exchanger 2.

The outflow side 11b of the first expansion device 11 is connected to the inflow side 4a of the vehicle interior heat exchanger 4, and the outflow side 4b of the vehicle interior heat exchanger 4 is a check valve (second refrigerant control unit). It is connected to the inflow side 3a of the second heat exchanger 3 via the 13 and the second expansion device (E-2) 14. Therefore, the compressor 10, the first heat exchanger 2, the first inflator 11, the passenger compartment outdoor heat exchanger 4, the check valve 13, the second inflator 14, the second heat exchanger 3, and the accumulator 12 , A refrigerant circulation cycle connected in a loop in the order of the compressor 10 is formed.

Further, the refrigerant flow path between the outflow side 2b of the first heat exchanger 2 and the inflow side 11a of the first expansion device 11, and the inflow of the outflow side 13b of the check valve 13 and the second expansion device 14. The refrigerant flow path to and from the side 14a is connected by a first bypass flow path 16 having a first on-off valve (V-1: corresponding to a first refrigerant control unit) 15. Further, between the refrigerant flow path between the outflow side 4b of the vehicle interior heat exchanger 4 and the inflow side 13a of the check valve 13 and the outflow side 3b of the second heat exchanger 3 and the inflow side 12a of the accumulator 12. Is connected to the refrigerant flow path of No. 1 by a second bypass flow path 18 opened and closed by a second on-off valve (V-2: corresponding to a third refrigerant control unit) 17.

Here, in the above-described configuration example, the first expansion device 11 uses an electromagnetic expansion valve capable of narrowing, closing, and fully opening the refrigerant flow path by a control signal from the outside. Further, the second expansion device 14 uses an electromagnetic control valve capable of narrowing and closing the refrigerant flow path by a control signal from the outside. Further, the check valve 13 may be replaced with a third on-off valve (V-3) 19 that opens and closes the flow path. The check valve 13 and the third on-off valve (V-3) 19 correspond to the second refrigerant control unit.

Then, among the refrigerant flow paths between the outflow side 4b of the vehicle interior heat exchanger 4 and the inflow side 14a of the second expansion device 14, the first bypass flow path 16 merges from the merging portion (A) to the first. A strainer 20 that captures foreign matter in the refrigerant is arranged between the expansion device 14 and 2.
The strainer 20 may be provided with, for example, a mesh-like filter member in the middle of the pipe for capturing foreign matter in the refrigerant, or may be provided in the joint provided at the confluence portion (A).

As a configuration in which the strainer 20 is provided in the middle of the pipe, the strainer 20 may be housed inside a pipe joint connecting the pipes. For example, as shown in FIG. 2, the pipe joint 21 has a flare bolt 22 fixed to the outer periphery of the expanded end portion (diameter expanded portion P1a) of one pipe P1 and the end portion of the other pipe P2. It is configured to have a flare nut and 24 which are locked to the brim portion 23 formed in the above and are rotatably exteriorized, and a seal member (seal member) (the end portion of the other pipe P2 is attached to the end portion of the one pipe P1). For example, it is inserted via an O-ring (25), the end of one pipe P1 and the brim 23 are brought into contact with each other in the axial direction, and the flare nut 24 is screwed into the flare bolt 22 to maintain this state. In the case of a configuration in which the pipe is tightened in the axial direction, the strainer (filter member) 20 is inserted inside the enlarged diameter portion P1a of one pipe P1 and then the end portion of the other pipe P2 is inserted to attach the pipe. May be good.

Further, as an example of providing the strainer 20 at the merging portion (A), when the strainer 20 is accommodated in the connecting portion between the block joint 30 forming the merging portion (A) and the pipe P1 connected to the second expansion device 14. good. For example, as the block joint 30, a three-way block joint is used, and as shown in FIG. 5A, the end of the pipe P1 is sealed to the female side joint portion 31 of the block joint 30 by a sealing member (for example, O-ring) 32. When the fastening plate 34 is fixed to the block joint 33 with a bolt 35 so as to press the flange portion 33 provided at the end of the pipe P1 against the female side joint portion 31. May be attached by inserting the strainer (filter member) 20 inside the female side joint portion 31 and then inserting the end portion of the pipe P1. Further, as shown in FIG. 5B, the end portion of the pipe P1 is externally fitted to the male side joint portion 36 of the block joint 30 via a seal member (for example, an O-ring) 32 to maintain that state. Therefore, when the fastening plate 34 is fixed to the block joint 30 with a bolt 35 so as to press the flange portion 33 at the end of the pipe P1 from behind, a strainer (filter member) 20 is installed inside the end of the pipe P1. After the insertion, the end portion of the pipe P1 may be fitted onto the male side joint portion 36 to be attached.

The opening and closing of the first and second expansion devices 11, 14 and the on-off valves 15, 17, 19 and the opening and closing of the damper 9 are controlled by a control signal from the control unit 50. The control unit 50 is known in itself and includes an input circuit including an A / D converter, a multiplexer, etc., an arithmetic processing circuit including a ROM, RAM, a CPU, etc., an output circuit including a drive circuit, etc., and has an outside temperature. The outside air temperature signal from the outside air temperature sensor 51 that detects the above, the inside air temperature sensor 52 that detects the vehicle interior temperature, various signals for setting the operation mode, and the like are input, and these signals are input according to a predetermined program. It is designed to be processed.

In particular, when the dehumidifying / heating operation mode is set, the mode of dehumidifying / heating can be switched according to the outside air temperature, and if the outside air temperature is in the range of 0 to 10 ° C. (If), in order to increase the heat absorption capacity, two systems of flow using the vehicle interior heat exchanger 4 and the second heat exchanger 3 as heat exchangers are formed (from the first heat exchanger 2). The dehumidifying / heating operation mode (hereinafter referred to as the dehumidifying / heating mode (Parallel)) is set in which the refrigerant flows in parallel to the vehicle interior heat exchanger 4 and the second heat exchanger 3. Further, if the outside air temperature is in the range of 18 to 25 ° C. (when the outside air load is a relatively high medium heat load), the first heat exchanger 2 and the passenger compartment outside heat exchanger are used to increase the heat dissipation capacity. Dehumidifying and heating operation mode (hereinafter, dehumidifying and heating mode (hereinafter, dehumidifying and heating mode) It is set to (Series)). Further, if the outside air temperature is in the intermediate temperature range of 10 to 18 ° C. (when the outside air load is a relatively low medium-low heat load), the first heat exchanger 2 is used without using the outdoor heat exchanger 4. Only the second heat exchanger 3 is used as a heat exchanger, and only the second heat exchanger 3 is used as a heat absorber (the refrigerant from the first heat exchanger 2 flows by bypassing the vehicle interior heat exchanger 4) dehumidifying and heating operation mode. (Hereinafter referred to as dehumidifying / heating mode (By-Pass)).

The above-mentioned dehumidifying / heating operation mode determines which dehumidifying / heating operation mode to operate based on the above-mentioned outside air temperature at the initial stage of cycle operation, but the vehicle interior temperature is the target after a lapse of time. When approaching a temperature (for example, 25 ° C.), the dehumidifying / heating mode (Parallel) is switched to the dehumidifying / heating mode (By-Pass) regardless of whether or not the outside temperature of the vehicle is changed, and the dehumidifying / heating mode (By-Pass) is also used. You may switch from -Pass) to dehumidifying and heating mode (Series).

Next, among the control operations by the control unit 50, the expansion device (first expansion device (E-1) 11, second expansion device (E-2) 14), control valve (first on-off valve 15, Specific control operation examples of the second on-off valve 17, the third on-off valve 19) and the damper 9 will be described for each operation mode. In each operation mode, the blower 7 rotates according to the instruction from the control unit 50, the air that has passed through the inside / outside air switching device 5 is sent to the second heat exchanger 3, and then toward the first heat exchanger 2. It flows.

First, when the operation mode is set to the cooling operation mode, the control unit 50 fully opens the first expansion device (E-1) 11 and the second expansion device (E-1) 11 as shown in FIG. 4A. The expansion device (E-2) 14 of the above is squeezed. When the first and second on-off valves 15 and 17 are closed and the check valve 13 is replaced by the on-off valve 19, the on-off valve 19 is opened and the damper 9 is placed in the cooling position (opening 0%). Position).

Then, the compressed refrigerant discharged from the discharge side α of the compressor 10 passes through the first heat exchanger 2 without radiating heat because there is no air passing through the first heat exchanger 2, and passes through the first expansion device 11. Enter the passenger compartment heat exchanger 4. At this time, since the first expansion device 11 is fully open, it enters the vehicle interior heat exchanger 4 without being decompressed and expanded here, and after being radiated (condensed) here, the check valve 13 (or the check valve 13) (or The second expansion device 14 is reached via the third on-off valve 19) and the strainer 20, and the pressure is reduced by the second expansion device 14 to enter the second heat exchanger 3, where heat is absorbed (evaporation vaporization). After that, it is returned to the compressor 10 via the accumulator 12.
Therefore, the air sent from the upstream side of the air conditioning unit 1 is cooled by the second heat exchanger 3, bypasses the first heat exchanger 2, and is supplied to the vehicle interior as it is as cold air.

Further, in this cooling operation mode, since the first expansion device 11 is in the fully open state, even if foreign matter in the refrigerant is accumulated in the flow path of the first expansion device 11, a large amount and a high flow velocity are obtained. The refrigerant circulates at once, and the accumulated foreign matter is washed away. Further, since the strainer 20 is provided between the merging portion (A) and the second expansion device 14, foreign matter is contained in the refrigerant flowing from the merging portion (A) toward the second expansion device 14. Even when they are mixed, the foreign matter is captured by the strainer 20, and the inconvenience of clogging the second expansion device 14 is eliminated.

Moreover, since the strainer 20 is arranged between the merging portion A to which the first bypass flow path 16 is connected and the second expansion device 14, the refrigerant passing through the merging portion A passes through the vehicle interior heat exchanger 4. Since the refrigerant is in a gas-liquid mixed state that has passed through, the flow velocity is relatively slow because the volume of the refrigerant is reduced. Therefore, it is possible to avoid an increase in passage resistance due to the provision of the strainer 20.

Next, when the operation mode is set to the heating operation mode, the control unit 50 throttles the first expansion device 11 and sets the second expansion device 14 as shown in FIG. 4 (b). close. Further, when the first on-off valve 15 is closed, the second on-off valve 17 is opened, and the check valve 13 is replaced by the on-off valve 19, the on-off valve 19 is closed and the damper 9 is opened at the heating position (open). Set to 100% degree position).

Then, the compressed refrigerant discharged from the discharge side α of the compressor 10 is dissipated (condensed and liquefied) by the first heat exchanger 2, decompressed by the first expansion device 11, and reaches the vehicle interior heat exchanger 4. After being absorbed (evaporated and vaporized) here, it is returned to the compressor 10 via the accumulator 12 through the second on-off valve 17.
Therefore, the air sent from the upstream side of the air conditioning unit 1 passes through the second heat exchanger 3, but is not heat exchanged, and is all guided to the first heat exchanger 2 to be heated and warm air. It is supplied to the passenger compartment as.

In such a heating operation mode, the first expansion device 11 is throttled, but when the operation mode is switched to the fully open operation mode, a large amount of refrigerant having a high flow velocity will flow at once. Although foreign matter may be temporarily deposited, it will eventually be removed.

When the operation mode is set to the dehumidifying / heating operation mode and the outside air temperature is 0 to 10 ° C., the dehumidifying / heating operation mode (parallel) for a low heat load is set as shown in FIG. 5 (a). When the control unit 50 is set, the first and second expansion devices 11 and 14 are throttled, the first and second on-off valves 15 and 17 are opened, and the check valve 13 is replaced by the on-off valve 19. , The on-off valve 19 is closed, and the opening degree of the damper 9 is set to an arbitrary intermediate position.

Then, the compressed refrigerant discharged from the discharge side α of the compressor 10 is radiated (condensed and liquefied) by the first heat exchanger 2 and decompressed by the first expansion device 11 to reach the vehicle interior heat exchanger 4. After being absorbed (evaporated and vaporized) here, it is returned to the compressor 10 via the accumulator 12 through the second on-off valve 17. At the same time, the refrigerant that has passed through the first heat exchanger 2 reaches the second expansion device 14 via the strainer 20 through the first bypass flow path 16, where the pressure is reduced and the second heat exchange occurs. After being absorbed (evaporated and vaporized) by the vessel 3, it is returned to the compressor 10 via the accumulator 12.
Therefore, the air sent from the upstream side of the air conditioning unit 1 is dehumidified by the second heat exchanger 3, heated when passing through the first heat exchanger 2, and used as dry warm air. It is supplied indoors.

In such an operation mode, the first expansion device 11 and the second expansion device 14 are narrowed down, but in the first expansion device 11, when the operation mode is switched to a fully open operation mode. In addition, since a large amount of the refrigerant having a high flow velocity flows at once, it is possible to remove the accumulated foreign matter, and in the second expansion device 14, the strainer 20 causes the foreign matter in the refrigerant to be removed on the upstream side of the second expansion device 14. Since it is captured, there is no inconvenience of clogging.

Moreover, since the strainer 20 is arranged between the confluence portion A to which the first bypass flow path 16 is connected to the second expansion device 14, the refrigerant flowing through the second bypass flow path 18 does not flow in. Therefore, the flow velocity of the refrigerant flowing through the strainer 20 becomes relatively slow. Therefore, it is possible to avoid an increase in passage resistance due to the provision of the strainer 20.

Next, when the operation mode is set to the dehumidification / heating operation mode, when the outside air temperature is 10 to 18 ° C., as shown in FIG. 5 (b), the dehumidification / heating operation mode for medium and low heat loads Set to (By-Pass), the control unit 50 fully closes the first expansion device 11, throttles the second expansion device 14, opens the first on-off valve 15, and opens the second on-off valve 17. When closing and substituting the check valve 13 with the on-off valve 19, the on-off valve 19 is closed and the opening degree of the damper 9 is set to an arbitrary intermediate position.

Then, the compressed refrigerant discharged from the discharge side α of the compressor 10 is dissipated (condensed and liquefied) by the first heat exchanger 2, bypasses the vehicle interior heat exchanger 4, and flows through the first bypass passage 16. After that, it reaches the second expansion device 14 via the strainer 20, is depressurized by the second expansion device 14, and is supplied to the second heat exchanger 3. Then, after absorbing heat in the second heat exchanger 3, it is returned to the compressor 10 via the accumulator 12.
Therefore, the air sent from the upstream side of the air conditioning unit 1 is dehumidified by the second heat exchanger 3, heated when passing through the first heat exchanger 2, and used as dry warm air. It is supplied indoors.

Even in such an operation mode, foreign matter in the refrigerant is captured by the strainer 20 arranged between the confluence portion A of the first bypass flow path 16 and the second expansion device 14, so that the second expansion The accumulation of foreign matter on the device 14 is avoided.

In this operation mode, the refrigerant reaching the second expansion device 14 may be a gas phase refrigerant, but is cooled in the first heat exchanger 2. Therefore, the flow velocity of the refrigerant passing through the strainer 20 is often lower than that of the refrigerant passing through the discharge side α of the compressor 10 and the inflow side 2a of the first heat exchanger 2. Moreover, it is limited that this operation mode is selected and operated. Further, the circulation amount of the refrigerant is increased in this operation mode when it is desired to obtain a large amount of heat for heating the blown air in the first heat exchanger 2, and the operating speed of the compressor 10 is increased. From the viewpoint of energy saving, it is preferable to operate an electric heating device (not shown) arranged in the vicinity of the downstream side of the first heat exchanger 2 rather than extremely increasing the circulation amount of the refrigerant. Therefore, even if the operation mode shown in FIG. 5B is selected, there is no substantial increase in passage resistance due to the provision of the strainer 20.

Further, when the operation mode is set to the dehumidification / heating operation mode and the outside air temperature is 18 to 25 ° C., as shown in FIG. 5 (c), the dehumidification / heating operation mode for medium heat load ( The control unit 50 is set to Series), the first expansion device 11 is fully opened, the second expansion device 14 is throttled, the first on-off valve 15 is closed, the second on-off valve 17 is closed, and the check is stopped. When the valve 13 is replaced by the on-off valve 19, the on-off valve 19 is opened and the opening degree of the damper 9 is set to an arbitrary intermediate position.

Then, the compressed refrigerant discharged from the discharge side α of the compressor 10 is dissipated (condensed and liquefied) by the first heat exchanger 2, and is not depressurized by the first expansion device 11 to the vehicle interior heat exchanger 4. After being radiated (condensed and liquefied) again here, it is sent to the second expansion device 14 via the strainer 20, where it is depressurized and supplied to the second heat exchanger 3. Then, after absorbing heat in the second heat exchanger 3, it is returned to the compressor 10 via the accumulator 12.
Therefore, the air sent from the upstream side of the air conditioning unit 1 is dehumidified by the second heat exchanger 3, heated when passing through the first heat exchanger 2, and used as dry warm air. It is supplied indoors.

In such an operation mode, as in the cooling operation mode, the first expansion device 11 is in a fully open state, so that when foreign matter in the refrigerant is accumulated in the flow path of the first expansion device 11. However, a large amount of refrigerant with a high flow velocity flows at once, and the accumulated foreign matter is washed away. Further, since the strainer 20 is provided between the merging portion (A) and the second expansion device 14, foreign matter is mixed in the refrigerant flowing from the merging portion (A) toward the second expansion device 14. Even if this is the case, the foreign matter will be captured by the strainer 20, and the inconvenience of clogging the second expansion device 14 will be eliminated.

Moreover, since the strainer 20 is arranged between the confluence portion A to which the first bypass flow path 16 is connected to the second expansion device 14, the refrigerant passing therethrough is the first heat exchanger 2. And since the refrigerant is in a gas-liquid mixed state that has passed through the vehicle interior heat exchanger 4, the flow velocity of the refrigerant flowing through the strainer 20 is relatively slow. Therefore, it is possible to avoid an increase in passage resistance due to the provision of the strainer 20.

In the above configuration, the strainer 20 is provided between the confluence portion (A) and the second expansion device 14 while allowing the first expansion device 11 to be fully opened. It is possible to avoid the inconvenience that the expansion device is clogged with foreign matter, but in order to more reliably prevent the foreign matter flowing into the compressor, the accumulator 12 captures the foreign matter in the refrigerant passing therethrough. A strainer 12c may be provided.

The above configuration shows an example of a heat pump cycle capable of cooling, heating, and dehumidifying and heating the passenger compartment. However, with respect to the above configuration, for example, as shown in FIG. 6, heat generated by a battery (storage battery) or the like is generated. A third heat exchanger 42 may be further added to cool the body 45. That is, with respect to the cycle configuration of FIG. 1, the second heat exchanger 3 is on the downstream side of the merging portion (A) of the refrigerant flow path between the vehicle interior outdoor heat exchanger 4 and the second expansion device 14. The refrigerant flow path between the accumulator 12 and the accumulator 12 is connected via a branch flow path 40. Then, the third expansion device 41 and the third heat exchanger 42 are arranged in series on the branch flow path 40, and the refrigerant flowing from the merging portion (A) to the downstream side is transferred to the second expansion device 14. And to the third expansion device 41.
In this example, the third expansion device 41 shows an example in which an electromagnetic expansion valve capable of throttled the refrigerant flow path by a control signal from the control unit 50 is used, but it is fixed if it is not necessary to change the throttle amount. An orifice may be used instead.

In this configuration, the strainer 20 is connected to the branch flow path 40 from the merging portion (A) of the refrigerant flow paths between the vehicle interior heat exchanger 4 and the second expansion device 14. It is provided between the branch site (B).
Even in such a configuration, even if the strainer 20 is provided with, for example, a mesh-like filter member that captures foreign matter in the refrigerant in the middle of the piping as shown in FIG. 2, as shown in FIG. , It may be provided in the joint provided at the confluence portion (A).

The heating element 45 is, for example, a battery (storage battery) that supplies electric power to a vehicle traveling motor. When the battery is charged, it generates heat, and this heat may shorten the life of the battery. However, it is expected that the life of the product will be extended by suppressing the temperature rise by cooling. As another example, the heating element 45 includes an electronic circuit that controls a running state of an electric vehicle, and is expected to prevent unintended bugs in the electronic circuit and extend the product life by cooling the heating element 45.

In the above-described configuration shown in FIG. 6, next, the expansion device by the control unit 50 (first expansion device (E-1) 11, second expansion device (E-2) 14, third expansion device (E). -3) 41), specific control operation examples of the control valve (first on-off valve 15, second on-off valve 17, third on-off valve 19) and damper 9 will be described for each operation mode. In each operation mode, the blower 7 rotates according to the instruction from the control unit 50, the air that has passed through the inside / outside air switching device 5 is sent to the second heat exchanger 3, and then toward the first heat exchanger 2. It flows.

First, when the operation mode is set to the cooling operation mode, the control unit 50 fully opens the first expansion device (E-1) 11 and the second expansion device (E-1) 11 as shown in FIG. 7A. The expansion device (E-2) 14 of the above is squeezed, and the third expansion device (E-3) 41 is squeezed. When the first and second on-off valves 15 and 17 are closed and the check valve 13 is replaced by the on-off valve 19, the on-off valve 19 is opened and the damper 9 is placed in the cooling position (opening 0%). Position).

Then, the compressed refrigerant discharged from the discharge side α of the compressor 10 passes through the first heat exchanger 2 without radiating heat because there is no air passing through the first heat exchanger 2, and passes through the first expansion device 11. Enter the passenger compartment heat exchanger 4. At this time, since the first expansion device 11 is fully open, it enters the vehicle interior heat exchanger 4 without being decompressed and expanded here, and after being radiated (condensed) here, the check valve 13 (or the check valve 13) (or The second expansion device 14 is reached via the third on-off valve 19) and the strainer 20, and the pressure is reduced by the second expansion device 14 to enter the second heat exchanger 3, where heat is absorbed (evaporation vaporization). After that, it is returned to the compressor 10 via the accumulator 12.
At the same time, the refrigerant flowing out of the vehicle interior heat exchanger 4 reaches the third expansion device 41 via the strainer 20, is decompressed by the third expansion device 41, and enters the third heat exchanger 42. After being absorbed (evaporated and vaporized) here, it is returned to the compressor 10 via the accumulator 12.

Therefore, the air sent from the upstream side of the air conditioning unit 1 is cooled by the second heat exchanger 3, bypasses the first heat exchanger 2, and is supplied to the vehicle interior as it is as cold air. Further, the heating element 45 is cooled by the third heat exchanger 42.

Further, in this cooling operation mode, since the first expansion device 11 is in the fully open state, even if foreign matter in the refrigerant is accumulated in the flow path of the first expansion device 11, a large amount and a high flow velocity are obtained. The refrigerant circulates at once, and the accumulated foreign matter is washed away. Further, since the strainer 20 is provided between the merging portion (A) and the branching portion (B), the strainer 20 is provided from the merging portion (A) toward the second expansion device 14 and the third expansion device 41. Even if foreign matter is mixed in the flowing refrigerant, it can be captured by the strainer 20, and there is no inconvenience that the second expansion device 14 and the third expansion device 41 are clogged.

Moreover, since the strainer 20 is arranged between the confluence portion A and the branch portion B to which the first bypass flow path 16 is connected, the refrigerant passing therethrough has passed through the vehicle interior heat exchanger 4. Since the refrigerant is in a liquid-mixed state, the flow velocity is relatively slow because the volume of the refrigerant is reduced. Therefore, it is possible to avoid an increase in passage resistance due to the provision of the strainer 20.

Next, when the operation mode is set to the heating operation mode, the control unit 50 throttles the first expansion device 11 and closes the second expansion device 14, as shown in FIG. 7B. , The third expansion device 41 is squeezed. Further, when the first on-off valve 15 is closed, the second on-off valve 17 is opened, and the check valve 13 is replaced by the on-off valve 19, the on-off valve 19 is closed and the damper 9 is opened at the heating position (open). Set to 100% degree position).

Then, the compressed refrigerant discharged from the discharge side α of the compressor 10 is dissipated (condensed and liquefied) by the first heat exchanger 2, decompressed by the first expansion device 11, and reaches the vehicle interior heat exchanger 4. After being absorbed (evaporated and vaporized) here, it is returned to the compressor 10 via the accumulator 12 through the second on-off valve 17.
At the same time, the refrigerant flowing out of the vehicle interior heat exchanger 4 passes through the bypass flow path 16 and reaches the third expansion device 41 via the strainer 20, and is depressurized by the third expansion device 41. It enters the heat exchanger 42 of No. 3, where it is endothermic (evaporated and vaporized) and then returned to the compressor 10 via the accumulator 12.

Therefore, the air sent from the upstream side of the air conditioning unit 1 passes through the second heat exchanger 3, but is not heat exchanged, and is all guided to the first heat exchanger 2 to be heated and warm air. It is supplied to the passenger compartment as. Further, the heating element 45 is cooled by the third heat exchanger 42.

In such a heating operation mode, the first expansion device 11 is throttled, but when the operation mode is switched to the fully open operation mode, a large amount of refrigerant having a high flow velocity flows at once, so that foreign matter is temporarily discharged. Even if it is deposited, it will be removed eventually. Further, since the strainer 20 is provided between the merging portion (A) and the branching portion (B), foreign matter is mixed in the refrigerant flowing from the merging portion (A) toward the third expansion device 41. Even if it is done, it can be captured by the strainer 20, and the inconvenience that the third expansion device 41 is clogged is eliminated.
Moreover, since the strainer 20 is arranged between the merging portion A to which the first bypass flow path 16 is connected and the branch portion B to which the branch flow path 40 is connected, the second bypass flow path 18 is provided. Since the flowing refrigerant does not flow in, the flow velocity of the refrigerant flowing through the strainer 20 becomes relatively slow. Therefore, it is possible to avoid an increase in passage resistance due to the provision of the strainer 20.

When the operation mode is set to the dehumidifying / heating operation mode and the outside air temperature is 0 to 10 ° C., the dehumidifying / heating operation mode (parallel) for a low heat load is set as shown in FIG. 8 (a). Once set, the control unit 50 throttles the first expansion device 11, the second expansion device 14, and the third expansion device 41. When the first and second on-off valves 15 and 17 are opened and the check valve 13 is replaced by the on-off valve 19, the on-off valve 19 is closed and the opening of the damper 9 is set to an arbitrary intermediate position. Set.

Then, the compressed refrigerant discharged from the discharge side α of the compressor 10 is radiated (condensed and liquefied) by the first heat exchanger 2 and decompressed by the first expansion device 11 to reach the vehicle interior heat exchanger 4. After being absorbed (evaporated and vaporized) here, it is returned to the compressor 10 via the accumulator 12 through the second on-off valve 17. At the same time, the refrigerant that has passed through the first heat exchanger 2 reaches the second expansion device 14 via the strainer 20 through the first bypass flow path 16, where the pressure is reduced and the second heat exchange occurs. After being absorbed (evaporated and vaporized) by the vessel 3, it is returned to the compressor 10 via the accumulator 12.
Further, the refrigerant that has passed through the bypass passage 16 reaches the third expansion device 41 via the strainer 20, is depressurized by the third expansion device 41, enters the third heat exchanger 42, and absorbs heat (here). After being evaporated and vaporized, it is returned to the compressor 10 via the accumulator 12.

Therefore, the air sent from the upstream side of the air conditioning unit 1 is dehumidified by the second heat exchanger 3, heated when passing through the first heat exchanger 2, and used as dry warm air. It is supplied indoors. Further, the heating element 45 is cooled by the third heat exchanger 42.

In such an operation mode, all the inflating devices (first inflating device 11, second inflating device 14, third inflating device 41) are narrowed down, but in the first inflating device 11. When the operation mode is switched to the fully open operation mode, a large amount of the refrigerant having a high flow velocity flows at once, so that it is possible to remove the accumulated foreign matter, and the second expansion device 14 and the third expansion device 14 and the third In the expansion device 41, foreign matter in the refrigerant is captured by the strainer 20 on the upstream side thereof, so that there is no inconvenience of clogging.

Moreover, the strainer 20 is arranged between the merging portion A to which the first bypass flow path 16 is connected to the branch portion B to which the branch flow path 40 is connected, and the refrigerant flowing through the second bypass flow path 18 is provided. Since it does not flow in, the flow velocity of the refrigerant flowing through the strainer 20 becomes relatively slow. Therefore, it is possible to avoid an increase in passage resistance due to the provision of the strainer 20.

When the operation mode is set to the dehumidification / heating operation mode and the outside air temperature is 10 to 18 ° C., as shown in FIG. 8B, the dehumidification / heating operation mode for medium and low heat loads (By- Pass), the control unit 50 fully closes the first expansion device 11, throttles the second expansion device 14, and throttles the third expansion device 41. Further, when the first on-off valve 15 is opened, the second on-off valve 17 is closed, and the check valve 13 is replaced by the on-off valve 19, the on-off valve 19 is closed and the opening degree of the damper 9 is arbitrarily adjusted. Set to the intermediate position.

Then, the compressed refrigerant discharged from the discharge side α of the compressor 10 is radiated (condensed and liquefied) by the first heat exchanger 2, bypassing the vehicle interior heat exchanger 4 and passing through the first bypass flow path 16. It flows and reaches the second expansion device 14 via the strainer 20. Then, after the pressure is reduced by the second expansion device 12, it is supplied to the second heat exchanger 3, and after absorbing heat by the second heat exchanger 3, it is returned to the compressor 10 via the accumulator 12.
At the same time, the refrigerant that has passed through the bypass flow path 16 reaches the third expansion device 41 via the strainer 20, is depressurized by the third expansion device 41, and enters the third heat exchanger 42. Here, after being absorbed (evaporated and vaporized), it is returned to the compressor 10 via the accumulator 12.

Therefore, the air sent from the upstream side of the air conditioning unit 1 is dehumidified by the second heat exchanger 3, heated when passing through the first heat exchanger 2, and used as dry warm air. It is supplied indoors. Further, the heating element 45 is cooled by the third heat exchanger 42.

Even in such an operation mode, foreign matter in the refrigerant is captured by the strainer 20 arranged between the merging portion A to which the first bypass flow path 16 is connected and the branch portion B to which the branch flow path 40 is connected. Therefore, foreign matter does not accumulate on the second expansion device 14 and the third expansion device 41.

In this operation mode, the refrigerant reaching the second expansion device 14 and the third expansion device 41 may be a gas phase refrigerant, but is cooled by the first heat exchanger 2. Therefore, the flow velocity of the refrigerant passing through the strainer 20 is often lower than that of the refrigerant passing through the discharge side α of the compressor 10 and the inflow side 2a of the first heat exchanger. Moreover, it is limited that this operation mode is selected and operated. Further, the circulation amount of the refrigerant is increased in this operation mode when it is desired to obtain a large amount of heat for heating the blown air in the first heat exchanger 2, and the operating speed of the compressor 10 is increased. From the viewpoint of energy saving, it is preferable to operate an electric heating device (not shown) arranged in the vicinity of the downstream side of the first heat exchanger 2 rather than extremely increasing the circulation amount of the refrigerant. Therefore, even if the operation mode shown in FIG. 8B is selected, there is no substantial increase in passage resistance due to the provision of the strainer 20.

Further, when the operation mode is set to the dehumidification / heating operation mode and the outside air temperature is 18 to 25 ° C., as shown in FIG. 8C, the dehumidification / heating operation mode for medium heat load ( The control unit 50 is set to Series), the first expansion device 11 is fully opened, the second expansion device 14 is throttled, and the third expansion device 41 is throttled. Further, when the first on-off valve 15 is closed, the second on-off valve 17 is closed, and the check valve 13 is replaced by the on-off valve 19, the on-off valve 19 is opened and the opening degree of the damper 9 is arbitrarily adjusted. Set to the intermediate position.

Then, the compressed refrigerant discharged from the discharge side α of the compressor 10 is dissipated (condensed and liquefied) by the first heat exchanger 2, and is not depressurized by the first expansion device 11 to the vehicle interior heat exchanger 4. After being radiated (condensed and liquefied) again here, it is sent to the second expansion device 14 via the strainer 20, where it is depressurized and supplied to the second heat exchanger 3. Then, after absorbing heat in the second heat exchanger 3, it is returned to the compressor 10 via the accumulator 12.
At the same time, the refrigerant flowing out of the vehicle interior outdoor heat exchanger 4 reaches the third expansion device 41 via the strainer 20, and is decompressed by the third expansion device 41 to be decompressed by the third heat exchanger 42. After being absorbed (evaporated and vaporized) here, it is returned to the compressor 10 via the accumulator 12.

Therefore, the air sent from the upstream side of the air conditioning unit 1 is dehumidified by the second heat exchanger 3, heated when passing through the first heat exchanger 2, and used as dry warm air. It is supplied indoors. Further, the heating element 45 is cooled by the third heat exchanger 42.

In such an operation mode, as in the cooling operation mode, the first expansion device 11 is in a fully open state, so that when foreign matter in the refrigerant is accumulated in the flow path of the first expansion device 11. However, a large amount of refrigerant with a high flow velocity flows at once, and the accumulated foreign matter is washed away. Further, since the strainer 20 is provided between the merging portion (A) and the branching portion (B), the strainer 20 is provided from the merging portion (A) toward the second expansion device 14 and the third expansion device 41. Even if foreign matter is mixed in the flowing refrigerant, it can be captured by the strainer 20, and there is no inconvenience that the second expansion device 14 and the third expansion device 41 are clogged.

Moreover, since the strainer 20 is arranged between the confluence portion A to which the first bypass flow path 16 is connected to the branch portion B to which the branch flow path 40 is connected, the refrigerant passing therethrough is the first. Since the refrigerant is in a gas-liquid mixed state that has passed through the heat exchanger 2 and the heat exchanger 4 outside the vehicle interior, the flow velocity of the refrigerant flowing through the strainer 20 is relatively slow. Therefore, it is possible to avoid an increase in passage resistance due to the provision of the strainer 20.

In the above, the mode for carrying out the invention has been described, but it goes without saying that the embodiment can be appropriately changed without departing from the object of the present invention. For example, the configuration for switching the operation mode using the outside air temperature as an index when the dehumidifying / heating operation mode is set has been described, but instead of this, a cooling temperature detecting means is provided directly to the second heat exchanger 3 or downstream. A predetermined cooling temperature may be set at the same time, and the operation mode of the dehumidifying / heating operation may be switched depending on whether or not the temperature detected by the cooling temperature detecting means exceeds the predetermined cooling temperature. Further, a heating temperature detecting means is provided directly or downstream in the first heat exchanger 2, and an operation mode of dehumidifying and heating operation is performed depending on whether or not the temperature detected by the heating temperature detecting means exceeds a predetermined heating temperature. May be switched.

1 Air conditioning unit 2 1st heat exchanger 3 2nd heat exchanger 4 Outdoor heat exchanger 11 1st expansion device 12 Accumulator 10 Compressor 15 1st on-off valve (V-1)
14 Second expansion device 16 First bypass flow path 17 Second on-off valve (V-2)
18 Second bypass flow path 19 Third on-off valve (V-3)
20 Strainer 40 Branch flow path 41 Third expansion device 42 Third heat exchanger 45 Heating element

Claims (3)

The compressor (10), the first heat exchanger (2) arranged in the air conditioning unit (1) and whose ventilation amount is adjusted by the damper (9), and the first heat exchanger (2) arranged in the air conditioning unit. A second exchanger (3) arranged on the upstream side in the air conditioning unit, an outdoor heat exchanger (4) capable of exchanging heat with the outside air, and a refrigerant flow path are narrowed down. It has a first expansion device (11) capable of closing and fully opening, a second expansion device (14) capable of narrowing and closing the refrigerant flow path, and an accumulator (12). death,
The compressor (10), the first heat exchanger (2), the first inflator (11), the outdoor heat exchanger (4), the second inflator (14), the first. The heat exchanger (3) of 2 and the accumulator (12) are connected in a loop at least in this order.
Between the refrigerant flow path between the first heat exchanger (2) and the first expansion device (11) and between the vehicle interior heat exchanger (4) and the second expansion device (14). Is connected to the refrigerant flow path of the above via a first bypass flow path (16) provided with a first refrigerant control unit (15).
Of the refrigerant flow paths between the vehicle interior heat exchanger (4) and the second expansion device (14), on the upstream side of the merging portion (A) with the first bypass flow path (16). A second refrigerant control unit (13, 19) for blocking the flow of the refrigerant from the merging portion to the upstream side is provided, and the vehicle interior heat exchanger (4) and the second refrigerant control unit (13, 19) are provided. ) And the refrigerant flow path between the second heat exchanger (3) and the accumulator (12) are provided with a second refrigerant control unit (17). Connected via the bypass flow path (18)
Of the refrigerant flow paths between the vehicle interior heat exchanger (4) and the second expansion device (14), between the merging portion (A) and the second expansion device (14). A strainer (20) for capturing foreign matter in the refrigerant is provided .
A third heat exchanger (42) for cooling the heating element (45) and a third expansion device (41) capable of narrowing the refrigerant flow path are further provided.
Of the refrigerant flow paths between the passenger compartment outdoor heat exchanger (4) and the second expansion device (14), the downstream side of the confluence portion (A) and the second heat exchanger (3). The refrigerant flow path between the accumulator (12) and the accumulator (12) is connected via a branch flow path (40) connecting the third expansion device (41) and the third heat exchanger (42). ,
The strainer (20) has a branch flow path (40) from the merging portion (A) of the refrigerant flow paths between the vehicle interior heat exchanger (4) and the second expansion device (14). An air conditioner for a vehicle, which is provided between the branch portion (B) to which the air conditioner is connected. The strainer (20) connects pipes on the downstream side of the confluence portion (A) of the refrigerant flow paths between the vehicle interior heat exchanger (4) and the second expansion device (14). The vehicle air conditioner according to claim 1 , wherein the air conditioner is arranged at a portion or a joint portion of the confluence portion (A). The vehicle air conditioner according to claim 1 or 2 , wherein the accumulator (12) is provided with an accumulator strainer (12c) for capturing foreign matter flowing into the accumulator (12).

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