JP5884080B2 - Air conditioner for vehicles - Google Patents

Description

  The present invention relates to a vehicle air conditioner.

  Conventionally, for example, in a car equipped with a gasoline engine, a heat pump is used for cooling, while waste heat of the engine is used for heating. In recent years, hybrid vehicles with a small amount of engine waste heat, and electric vehicles that cannot use engine waste heat have become widespread. It has been developed. For example, Patent Document 1 discloses a vehicle air conditioner 100 as shown in FIGS. 9 (a) and 9 (b).

  The vehicle air conditioner 100 can switch between a cooling operation, a reheating and dehumidifying operation, a defrosting operation in which a refrigerant is circulated through the same flow path, and two dehumidifying and heating operations. Specifically, the vehicle air conditioner 100 includes a main circuit 110 in which a compressor 111, a first indoor heat exchanger 112, a first expansion valve 113, and a second indoor heat exchanger 114 are connected in this order. The first indoor heat exchanger 112 and the second indoor heat exchanger 114 are arranged in the duct 150 so that the second indoor heat exchanger 114 is located on the leeward side and the first indoor heat exchanger 112 is located on the leeward side. Has been.

  The main circuit 110 is provided with a first on-off valve 115 between the compressor 111 and the first indoor heat exchanger 112, and a check valve between the first indoor heat exchanger 112 and the first expansion valve 113. 116 is provided. A liquid receiver 117 is disposed between the check valve 116 and the first expansion valve 113, and an accumulator 118 is disposed between the second indoor heat exchanger 114 and the compressor 111.

  The vehicle air conditioner 100 also includes a bypass 120 including an outdoor heat exchanger 121 for allowing the refrigerant to flow by bypassing the first indoor heat exchanger 112 during the cooling operation. The bypass passage 120 branches from the main circuit 110 between the compressor 111 and the first on-off valve 115 and is connected to the main circuit 110 between the check valve 116 and the liquid receiver 117. In the bypass passage 120, a second on-off valve 125 is provided on the upstream side of the outdoor heat exchanger 121, and a check valve 122 is provided on the downstream side of the outdoor heat exchanger 121.

  Furthermore, the vehicle air conditioner 100 branches from the main circuit 110 between the liquid receiver 117 and the first expansion valve 113 and is connected to the bypass 120 between the outdoor heat exchanger 121 and the check valve 122. A dedicated heating path 130 branched from the bypass path 120 between the dedicated path 140, the second on-off valve 125, and the outdoor heat exchanger 121 and connected to the main circuit 110 between the second indoor heat exchanger 114 and the accumulator 118. It has. A second expansion valve 141 is provided in the first heating exclusive path 140, and a third opening / closing valve 135 is provided in the second heating exclusive path 130.

  During the cooling operation, the first on-off valve 115 and the third on-off valve 135 are closed, and the second on-off valve 125 is opened. As a result, the refrigerant discharged from the compressor 111 is serially connected in this order to the outdoor heat exchanger 121, the first expansion valve 113, and the second indoor heat exchanger 114, as indicated by solid arrows in FIG. 9A. To pass through. During the reheating and dehumidifying operation, the first on-off valve 115 is opened from the state during the cooling operation. As a result, the refrigerant flows in parallel through the outdoor heat exchanger 121 and the first indoor heat exchanger 112 as indicated by broken line arrows in FIG.

On the other hand, during the first dehumidifying and heating operation, the first on-off valve 115 is opened, and the second on-off valve 125 and the third on-off valve 135 are closed. As a result, the refrigerant discharged from the compressor 111 passes through the first indoor heat exchanger 112, the first expansion valve 113, and the second indoor heat exchanger 114 as shown by broken line arrows in FIG. 9B. Pass in series. During the second dehumidifying and heating operation, the third on-off valve 135 is opened from the state during the first dehumidifying and heating operation. As a result, the refrigerant flows in parallel through the first expansion valve 113, the first indoor heat exchanger 112, the second expansion valve 141, and the outdoor heat exchanger 121, as indicated by solid line arrows in FIG. 9B.

Japanese Patent Laid-Open No. 7-232547

  However, in the vehicle air conditioner 100 shown in FIGS. 9A and 9B, there is no means for adjusting the amount of refrigerant flowing through the outdoor heat exchanger 121 and the first indoor heat exchanger 112 during the reheating and dehumidifying operation. The capacity of the first indoor heat exchanger 112 that functions as a heat exchanger cannot be controlled.

  An object of this invention is to provide the vehicle air conditioner which can control the capability of an indoor condenser at the time of reheating dehumidification driving | operation in view of such a situation.

  In order to solve the above-described problems, a vehicle air conditioner according to the present invention is a vehicle air conditioner capable of switching between a heating operation, a cooling operation, and a reheating and dehumidifying operation, and includes a compressor, an indoor condenser, and a first expansion mechanism. And an indoor heat exchange circuit in which the indoor evaporator is connected in this order, an outside air inlet, an inside air inlet, and an outlet to the vehicle interior, and the indoor condenser and the indoor evaporator are inside the indoor evaporator. A duct arranged so that air that has passed through the condenser can pass through the indoor condenser, an outdoor heat exchanger, and a second expansion mechanism, and one end on the second expansion mechanism side includes the first expansion mechanism and the second expansion mechanism An outdoor heat exchange path connected to the indoor heat exchange circuit between the indoor evaporators, and the outdoor heat of the outdoor heat exchange path branched from the indoor heat exchange circuit between the compressor and the indoor condenser First connected to the other end of the exchanger side An entanglement path, a second communication path branched from the indoor heat exchange circuit between the indoor evaporator and the compressor and connected to the other end of the outdoor heat exchange path, and the outdoor heat exchange in the indoor heat exchange circuit An on-off valve disposed between a position where one end of the path is connected and a position where the second communication path branches; and the other end of the outdoor heat exchange path during the cooling operation and the reheating and dehumidifying operation. The second state is switched to the first state that communicates with the indoor heat exchange circuit through one communication path, and the other end of the outdoor heat exchange path communicates with the indoor heat exchange circuit through the second communication path during the heating operation. And a channel selection means that can be switched.

  According to the above configuration, when the on-off valve is closed during the heating operation, the refrigerant discharged from the compressor passes through the indoor condenser, the first expansion mechanism, the second expansion mechanism, and the outdoor heat exchanger in this order for compression. Inhaled again by the machine. When the on-off valve is opened, the refrigerant that has passed through the first expansion mechanism is also guided to the indoor evaporator, so that air flowing in the duct can be dehumidified. On the other hand, during the cooling operation and the reheating and dehumidifying operation, the refrigerant discharged from the compressor can flow in parallel to the outdoor heat exchanger and the indoor condenser. At this time, since the refrigerant that has passed through the outdoor heat exchanger and the refrigerant that has passed through the indoor condenser merge via separate expansion mechanisms, the capacity of the indoor condenser can be controlled by these expansion mechanisms.

It is a schematic block diagram of the vehicle air conditioner which concerns on 1st Embodiment of this invention, and shows the flow of the refrigerant | coolant at the time of heating operation. It is a schematic block diagram of the vehicle air conditioner which concerns on 1st Embodiment of this invention, and shows the flow of the refrigerant | coolant at the time of air_conditionaing | cooling operation and reheating dehumidification operation. The schematic block diagram of the vehicle air conditioner of the modification of 1st Embodiment. It is a schematic block diagram of the vehicle air conditioner which concerns on 2nd Embodiment of this invention, and shows the flow of the refrigerant | coolant at the time of heating operation. It is a schematic block diagram of the vehicle air conditioner which concerns on 3rd Embodiment of this invention, and shows the flow of the refrigerant | coolant at the time of heating operation. It is a schematic block diagram of the vehicle air conditioner which concerns on 3rd Embodiment of this invention, and shows the flow of the refrigerant | coolant at the time of air_conditionaing | cooling operation and reheating dehumidification operation. (A) And (b) is a figure which shows the example which divided | segmented the external air inlet and the internal air inlet. The schematic block diagram of the vehicle air conditioner of the modification of 3rd Embodiment It is a schematic block diagram of the conventional vehicle air conditioner, (a) shows the refrigerant | coolant flow at the time of air_conditionaing | cooling operation, reheating dehumidification operation, and defrost operation, (b) shows the refrigerant | coolant flow at the time of dehumidification heating operation. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description relates to an example of the present invention, and the present invention is not limited to these.

(First embodiment)
1 and 2 show a vehicle air conditioner 1A according to a first embodiment of the present invention. This vehicle air conditioner 1A is capable of switching between heating operation, cooling operation, and reheating dehumidification operation, and includes a duct 5 for taking outside air into the vehicle interior and circulating the inside air, and a heat pump for circulating the refrigerant A circuit 10 and a control device 7 (in FIG. 1, only a part of a signal line is drawn for simplification of the drawing) are provided. 1 and 2 schematically show the shape of the duct 5, and the actual shape of the duct 5 may be swollen or swelled in accordance with the space where the duct 5 is installed. Good.

  The duct 5 has an outside air introduction port 5a for introducing outside air into the duct 5 and an inside air introduction port 5b for introducing inside air into the duct 5 at one end portion, and the other end portion. The air outlet 5c for blowing out the temperature-adjusted air into the passenger compartment. Although illustration is omitted, in the vicinity of the outside air introduction port 5a and the inside air introduction port 5b, the amount of outside air introduced into the duct 5 from the outside air introduction port 5a and the inside air introduction port 5b are introduced into the duct 5. An intake damper that adjusts the ratio of the amount of inside air is arranged. Moreover, the blower outlet 5c may be branched into several, such as a defroster blower outlet, a face blower outlet, and a foot blower outlet.

  In the duct 5, a blower 51 that generates an air flow from one end of the duct 5 toward the other end is disposed. The blower 51 may be a blower or a fan. Further, the blower 51 can be arranged not near the outside air inlet 5a and the inside air inlet 5b but near the outlet 5c.

The heat pump circuit 10 includes a loop-shaped indoor heat exchange circuit 2, an outdoor heat exchange path 3, which is three linear flow paths, a first communication path 4A, and a second communication path 4B. The refrigerant circulating in the heat pump circuit 10, R134a, R410A, HFO- 1234yf, HFO-1234ze, in addition to such CO _2, other HFC system, HC-based and available.

  The indoor heat exchange circuit 2 includes a compressor 21, an indoor condenser 22, a first expansion valve 23, and an indoor evaporator 25, which are connected in this order by refrigerant piping. In the indoor heat exchange circuit 2, an on-off valve 24 is provided between the first expansion valve 23 and the indoor evaporator 25, and an accumulator 27 is provided between the indoor evaporator 25 and the compressor 21. .

  The compressor 21 is driven by an electric motor (not shown), compresses the refrigerant sucked from the suction port, and discharges it from the discharge port. The electric motor may be disposed inside the compressor 21 or may be disposed outside. For example, in an electric vehicle, the electric motor may be a vehicle driving motor.

  The indoor condenser 22 and the indoor evaporator 25 are arranged in the duct 5 so that air that has passed through the indoor evaporator 25 can pass through the indoor condenser 22. The indoor evaporator 25 and the indoor condenser 22 perform heat exchange between the inside air and / or outside air supplied by the blower 51 and the refrigerant.

  In the present embodiment, the indoor evaporator 25 is arranged in the duct 5 such that the first air passage 5A passing through the indoor evaporator 25 and the second air passage 5B not passing through the indoor evaporator 25 form a layer. Has been. Similarly, the indoor condenser 22 is also arranged in the duct 5 so that the third air passage 5C passing through the indoor condenser 22 and the fourth air passage 5D not passing through the indoor condenser 22 form a layer. Yes. Further, in the duct 5, there are a first partition plate 52 that partitions the first air passage 5A and the second air passage 5B, and a second partition plate 53 that partitions the third air passage 5C and the fourth air passage 5D. It is arranged. The indoor evaporator 25 and the indoor condenser 22 may be located on opposite sides of the first partition plate 52 and the second partition plate 53, or may be located on the same side.

  Furthermore, in the duct 5, the 1st adjustment damper 61 which adjusts the ratio of the air volume which flows through the 1st air path 5A, and the air volume which flows through the 2nd air path 5B, and the air volume and the 4th air path which flow through the 3rd air path A second adjustment damper 62 that adjusts the ratio of the amount of air flowing through 5D is provided. In the present embodiment, the second adjustment damper 62 is disposed between the first partition plate 52 and the second partition plate 53, and the first adjustment damper 61 is disposed on the windward side of the first partition plate 52. That is, the swing shaft of the first adjustment damper 61 is attached to the windward end of the first partition plate 52, and the swing shaft of the second adjustment damper 62 is attached to the windward end of the second partition plate 53. It has been. However, the first adjustment damper 61 is disposed in the reverse direction between the first partition plate 52 and the second partition plate 53, and the second adjustment damper 62 is disposed in the reverse direction on the leeward side of the second partition plate 53. Also good.

  The first adjustment damper 61 swings between a heat exchanger side blocking position that blocks the first air path 5A and a bypass side blocking position that blocks the second air path 5B, and the second adjustment damper 62 is It swings between a heat exchanger side blocking position that blocks the three air paths 5C and a bypass side blocking position that blocks the fourth air path 5D. In the following description, for simplification of description, the position of the first adjustment damper 61 where the air volume flowing through the first air path 5A and the air volume flowing through the second air path 5B are equal is defined as an equal position and an equal position. An intermediate position between the bypass side cutoff position is referred to as a bypass side suppression position, and an intermediate position between the uniform position and the heat exchanger side cutoff position is referred to as a heat exchanger side suppression position. On the other hand, for the second adjustment damper 62, the position located on the line connecting the leeward end of the first partition plate 41 and the windward end of the second partition plate 42 is an equal position, the equal position and the bypass side. An intermediate position between the shut-off positions is referred to as a bypass-side restraining position, and an intermediate position between the uniform position and the heat exchanger-side shut-off position is referred to as a heat exchanger-side restraining position.

  The first expansion valve 23 is an example of an expansion mechanism that expands the refrigerant. As the expansion mechanism, a positive displacement expander that recovers power from the expanding refrigerant may be employed. In addition, a valve whose opening degree can be changed can be used as the expansion valve, and an electric expansion valve, a valve whose opening degree changes in two or more stages, a temperature type expansion valve, or the like may be adopted.

The on-off valve 24 is for making it possible to select two modes for the heating operation. That is, the heating operation includes a first heating operation in which the on-off valve 24 is closed and a second heating operation in which the on-off valve 24 is opened. The on-off valve 24 may be arranged on the downstream side of the indoor evaporator 25, but is preferably arranged on the upstream side of the indoor evaporator 25 as in the present embodiment.
This is to prevent low temperature refrigerant from flowing into the indoor evaporator 25 when the indoor evaporator 25 is not used.

  The outdoor heat exchange path 3 includes an outdoor heat exchanger 31 and a second expansion valve 32. One end 3 a on the second expansion valve 32 side of the outdoor heat exchange path 3 is connected to the indoor heat exchange circuit 2 between the first expansion mechanism 23 and the on-off valve 24.

  The outdoor heat exchanger 31 is disposed, for example, at the front of an automobile, and performs heat exchange between the running air of the vehicle and the outside air supplied by the fan 33 and the refrigerant. The outdoor heat exchanger 31 functions as a condenser during the cooling operation and the reheating and dehumidifying operation, and functions as an evaporator during the heating operation. Similar to the first expansion valve 23, the second expansion valve 32 is an example of an expansion mechanism that expands the refrigerant.

  The first communication path 4A branches from the indoor heat exchange circuit 2 between the compressor 21 and the indoor condenser 22, and is connected to the other end 3b of the outdoor heat exchange path 3 on the outdoor heat exchanger 31 side. The second communication path 4B branches from the indoor heat exchange circuit 2 between the indoor evaporator 25 and the accumulator 27 and is connected to the other end 3b of the outdoor heat exchange path 3. In the present embodiment, a three-way valve 41 is provided at a location where the first communication path 4 </ b> A and the second communication path 4 </ b> B are connected to the other end 3 b of the outdoor heat exchange path 3.

  The three-way valve 41 is an example of the flow path selection means of the present invention, and is switched to the first state (the state shown in FIG. 2) during the cooling operation and the reheating dehumidifying operation, and the second state (shown in FIG. 1) during the heating operation. State). The three-way valve 41 connects the other end 3b of the outdoor heat exchange path 3 to the indoor heat exchange circuit 2 through the first communication path 4A in the first state, and connects the other end 3b of the outdoor heat exchange path 3 to the second state in the second state. The indoor heat exchange circuit 2 is communicated with the communication path 4B. In addition, as a flow-path selection means of this invention, it is also possible to use the on-off valve provided in each of the 1st connection path 4A and the 2nd connection path 4B instead of the three-way valve 41. FIG.

  The compressor 21 and the various valves 23, 24, 32, 41, the first adjustment damper 61 and the second adjustment damper 62 described above are controlled by the control device 7. The control device 6 is connected to an operation panel (not shown) disposed in the passenger compartment, and performs a heating operation, a cooling operation, and a reheating dehumidifying operation. Hereinafter, the operation of the vehicle air conditioner 1A during each operation will be described.

<Heating operation>
During the heating operation, the control device 7 switches the three-way valve 41 to the second state. Thereby, the distribution of the refrigerant through the first communication path 4A is prohibited, and the distribution of the refrigerant through the second communication path 4B is permitted.

  As described above, the heating operation includes the first heating operation in which the on-off valve 24 is closed and the second heating operation in which the on-off valve 24 is opened. The on-off valve 24 is closed only during the first heating operation.

(1) 1st heating operation The 1st heating operation is performed when dehumidification is not required, for example at the time of starting. During the first heating operation, the refrigerant discharged from the compressor 21 passes through the indoor condenser 22, the first expansion valve 23, the second expansion valve 32, and the outdoor heat exchanger 31, as indicated by solid arrows in FIG. It passes in series in this order and is sucked into the compressor 21 again.

  In the first heating operation, one of the first expansion valve 23 and the second expansion valve 32 is fully opened or has a constant opening, and the other is adjusted so that the refrigerant sucked into the compressor 21 is in a predetermined overheated state. . Specifically, the temperature of the refrigerant sucked into the compressor 21 is detected by the temperature sensor 8, and the expansion valve is adjusted so that the temperature difference between the detected temperature and the saturation temperature on the low pressure side becomes a predetermined value. Is called.

  For air volume adjustment in the duct 5, the second adjustment damper 62 is set at the bypass side cutoff position. Although the 1st adjustment damper 61 is set to the heat exchanger side interruption | blocking position, when the indoor evaporator 25 is not wet with dew condensation water etc., since a refrigerant | coolant does not flow, it may be set to any position.

(2) Second heating operation In the present embodiment, the second heating operation is performed when dehumidification is necessary. During the second heating operation, the refrigerant discharged from the compressor 21 is divided into two tributaries after passing through the indoor condenser 22 and the first expansion valve 23, as indicated by broken line arrows in FIG. These tributaries merge after passing separately through the second expansion valve 32, the outdoor heat exchanger 31 and the indoor evaporator 25, and are sucked into the compressor 21 again.

  The first expansion valve 23 is adjusted so that the refrigerant sucked into the compressor 21 is in a predetermined overheated state. On the other hand, the second expansion valve 32 is adjusted so that the ratio of the refrigerant amount flowing to the indoor evaporator 25 and the refrigerant amount flowing to the outdoor heat exchanger 31 is appropriate. For example, since the outdoor heat exchanger 31 generally has a larger size than the indoor evaporator 25, the distribution ratio of the refrigerant may be determined according to the difference in size.

  For air volume adjustment in the duct 5, the second adjustment damper 62 is set at the bypass-side cutoff position, and the first adjustment damper 61 is set at, for example, the heat exchanger-side suppression position or the equivalent position. Thereby, the air flowing in the duct 5 is dehumidified by the indoor evaporator 25 and then heated by the indoor condenser 22.

(3) Defrosting operation When frost adheres to the outdoor heat exchanger 31 during the heating operation or at a predetermined interval, the control device 7 shifts from the heating operation to the dehumidifying operation. Specifically, the control device 7 switches the three-way valve 41 to the first state, and controls the first expansion valve 23 to be fully closed or a low opening degree. Thereby, the high temperature refrigerant | coolant discharged from the compressor 21 can be guide | induced to the outdoor heat exchanger 31, and the frost adhering to the outdoor heat exchanger 31 can be melt | dissolved.

  During the defrosting operation, the second expansion valve 32 is adjusted so that the refrigerant sucked into the compressor 21 is in a predetermined overheated state.

  If the outside air temperature is 0 ° C. or higher, the second expansion valve 32 is controlled to be fully closed while the three-way valve 41 is switched to the second state, and only the gas refrigerant passes through the indoor evaporator 25 to the compressor 5. By adjusting the first expansion valve 23 and / or the second adjustment damper 62 so as to return, defrosting is performed using outside air of 0 ° C. or higher while heating is performed with the amount of heat corresponding to the input of the compressor 5. be able to.

<Cooling operation>
During the cooling operation, the control device 7 switches the three-way valve 41 to the first state. Thereby, the circulation of the refrigerant through the first communication path 4A is permitted, and the circulation of the refrigerant through the second communication path 4B is prohibited.

  Further, the control device 7 controls the first expansion valve 23 to be fully closed or a low opening degree. As a result, all or most of the refrigerant discharged from the compressor 21 passes through the outdoor heat exchanger 31, the second expansion valve 32, and the indoor evaporator 25 in this order in series as shown by the solid arrows in FIG. Then, it is sucked into the compressor 21 again.

  The second expansion valve 32 is adjusted so that the refrigerant sucked into the compressor 21 is in a predetermined overheated state. Regarding the air volume adjustment in the duct 5, the first adjustment damper 61 is set at the bypass-side cutoff position, and the second adjustment damper 62 is set, for example, at the heat exchanger-side cutoff position.

  When the first expansion valve 23 is fully closed, the outdoor heat exchanger 31 branches from the indoor heat exchanger circuit 2 between the indoor condenser 22 and the first expansion valve 23 to the outdoor side on the other end 3b side. It is preferable that an escape path (not shown) connected to the heat exchange path 3 is provided and the refrigerant and oil accumulated in the indoor condenser 22 are allowed to escape through the escape path.

<Reheating dehumidification operation>
During the reheating and dehumidifying operation, the control device 7 switches the three-way valve 41 to the first state. Thereby, the circulation of the refrigerant through the first communication path 4A is permitted, and the circulation of the refrigerant through the second communication path 4B is prohibited.

  During the reheating and dehumidifying operation, the refrigerant is expanded by both the first expansion valve 23 and the second expansion valve 32. That is, the refrigerant discharged from the compressor 21 is first divided into two tributaries as indicated by broken line arrows in FIG. One tributary passes through the outdoor heat exchanger 31 and the second expansion valve 32, and the other tributary passes through the indoor condenser 22 and the first expansion valve 23. After that, those tributaries merge. The combined refrigerant passes through the indoor evaporator 25 and is sucked into the compressor 21 again.

  As described above, since the refrigerant that has passed through the outdoor heat exchanger 31 and the refrigerant that has passed through the indoor condenser 22 merge via separate expansion valves, the capacity of the indoor condenser 22 can be controlled by these expansion valves. .

  The second expansion valve 32 is adjusted so that the refrigerant sucked into the compressor 21 is in a predetermined overheated state. On the other hand, the first expansion valve 23 is adjusted so that the refrigerant flowing out of the indoor condenser 22 is in a predetermined supercooled state.

  For air volume adjustment in the duct 5, the first adjustment damper 61 is set at the bypass-side cutoff position, and the second adjustment damper 62 is set at, for example, the heat exchanger-side suppression position or the equivalent position. Thereby, the air flowing in the duct 5 is dehumidified by the indoor evaporator 25 and then heated by the indoor condenser 22.

<Modification>
It is also possible to heat or cool the outside air introduced into the duct 5 by utilizing the inside air discharged outside the passenger compartment for ventilation. In order to achieve this, for example, as shown in FIG. 3, the flow of the internal air discharged outside the passenger compartment flows across the duct 5 immediately downstream of the external air introduction port 5 a and the internal air introduction port 5 b in the duct 5. The heat exchanger 9 may be arranged so as to form a path. The heat exchanger 9 may be a total heat exchanger or a sensible heat exchanger. As the heat exchanger 9, a publicly known one can be used. As an example, a heat exchanger having a structure shown in FIG. 2 of Japanese Patent Application Laid-Open No. 2010-76506 (corrugated plates with orthogonal wave directions are alternately sandwiched between flat plates). Are laminated).

(Second Embodiment)
FIG. 4 shows a vehicle air conditioner 1B according to the second embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof may be omitted. This is the same in the third embodiment described later.

  In the vehicle air conditioner 1B of the present embodiment, an electromagnetic valve 26 is provided between the indoor evaporator 25 of the indoor heat exchange circuit 2 and the position where the second communication path 4B branches. The electromagnetic valve 26 can be switched between a decompressed state in which the refrigerant flowing out from the indoor evaporator 25 is decompressed to a predetermined pressure and a non-depressurized state in which the refrigerant is allowed to pass through, and corresponds to the decompressing mechanism of the present invention.

  The solenoid valve 26 is switched to a non-depressurized state during the cooling operation and the reheating dehumidification operation. On the other hand, during the second heating operation in which the on-off valve 24 is opened, the electromagnetic valve 26 is switched to the reduced pressure state when ice adheres to the indoor evaporator 25 or under conditions where ice can adhere to the indoor evaporator 25. During the first heating operation, since the refrigerant does not flow into the indoor evaporator 25, the electromagnetic valve 26 may be switched between the non-depressurized state and the depressurized state.

  The fact that ice has adhered to the indoor evaporator 25 can be known, for example, by installing an air flow meter on the leeward side of the indoor evaporator 25 and detecting the decrease in the air flow. Alternatively, a temperature sensor may be provided in the indoor evaporator 25, and it may be determined that ice has adhered to the indoor evaporator 25 when a temperature drop in the indoor evaporator 25 is detected. The condition that ice can adhere to the indoor evaporator 25 is, for example, when the temperature of the air supplied to the indoor evaporator 25 is equal to or lower than a predetermined temperature (for example, 5 ° C.). Alternatively, opening the on-off valve 24 may be a condition that allows ice to adhere to the indoor evaporator 25.

  During the second heating operation, the refrigerant discharged from the compressor 21 is divided into two tributaries after passing through the indoor condenser 22 and the first expansion valve 23, as indicated by broken line arrows in FIG. These tributaries merge after passing separately through the second expansion valve 32 and the outdoor heat exchanger 31, the indoor evaporator 25 and the electromagnetic valve 26, and are sucked into the compressor 21 again. At this time, the second expansion valve 32 is adjusted so that the refrigerant before joining flowing out of the outdoor heat exchanger 31 is in a predetermined overheated state.

  Since the electromagnetic valve 26 is disposed on the downstream side of the indoor evaporator 25, the temperature of the refrigerant in the indoor evaporator 25 is made higher than the temperature of the refrigerant in the outdoor heat exchanger 31 when the electromagnetic valve 26 is switched to a reduced pressure state. Can also be high. Thereby, the ice adhering to the indoor evaporator 25 can be melted, or the ice can be prevented from adhering to the indoor evaporator 25 in advance.

<Modification>
In the above-described embodiment, the electromagnetic valve 26 that can be switched between the decompression state and the non-decompression state is employed as the decompression mechanism of the present invention. However, as the decompression mechanism, an electromagnetic valve or an expansion valve that can be switched not only to the decompressed state and the non-depressurized state but also to the closed state that prohibits the circulation of the refrigerant may be employed. In this case, since the electromagnetic valve also functions as an on-off valve, the on-off valve 24 can be omitted. Alternatively, the pressure reducing mechanism may be configured by a fixed throttle such as an orifice or a capillary tube and a bypass path with an on-off valve that bypasses the fixed throttle.

(Third embodiment)
5 and 6 show a vehicle air conditioner 1C according to a third embodiment of the present invention. In the vehicle air conditioner 1 </ b> C of the present embodiment, the duct 5 is provided with a heating exhaust port 54 and a cooling exhaust port 56. In the present embodiment, the indoor evaporator 25 and the indoor condenser 22 are configured such that the first air passage 5A is continuous with the fourth air passage 5D and the second air passage 5B is continuous with the third air passage 5C. The first partition plate 52 and the second partition plate 53 are located on opposite sides of each other.

  In the present embodiment, each of the indoor evaporator 25 and the indoor condenser 22 is selectively supplied not only with a mixture of the outside air from the outside air introduction port 5a and the inside air from the inside air introduction port 5b but also one of the outside air and the inside air. It is possible. In order to realize this, for example, as shown in FIGS. 7A and 7B, the outside air introduction port 5 a and the inside air introduction port 5 b are configured in an L-shaped cross section, and they are divided by the dividing plate 58. A pair of intake dampers 59 may be disposed with the dividing plate 58 interposed therebetween.

  The heating exhaust port 54 is for discharging the air cooled by the indoor evaporator 25 to the outside of the vehicle compartment during the second heating operation in which the on-off valve 24 is opened. A heating discharge damper 55 that opens and closes the heating exhaust port 54 is attached to the duct 5.

  The heating exhaust damper 55 has a swing shaft on the leeward side of the heating exhaust port 54, and swings inward from the closed position where the heating exhaust port 54 is closed so that the heating exhaust port 54 is moved. open. That is, the heating exhaust damper 55 guides the air that has passed through the indoor evaporator 25 to the heating exhaust port 54 when the heating exhaust port 54 is opened. In the present embodiment, the heating exhaust damper 55 closes the heating exhaust port 54 and the leading end of the heating exhaust damper 55 approaches or comes into contact with the first partition plate 52 to block the first air passage 5A. It is possible to swing between the blocking position.

  The cooling exhaust port 56 is for discharging the air heated by the indoor condenser 22 during the cooling operation to the outside of the passenger compartment. A cooling discharge damper 57 that opens and closes the cooling exhaust port 56 is attached to the duct 5.

  The cooling exhaust damper 57 has a swing shaft on the leeward side of the cooling exhaust port 56, and swings inward from the closed position where the cooling exhaust port 56 is closed so that the cooling exhaust port 56 is opened. open. That is, the cooling exhaust damper 57 guides the air that has passed through the indoor condenser 22 to the cooling exhaust port 56 when the cooling exhaust port 56 is opened. In the present embodiment, the cooling exhaust damper 57 closes the cooling exhaust port 56 and the tip of the cooling exhaust damper 57 approaches or comes into contact with the second partition plate 53 to block the third air passage 5C. It is possible to swing between the blocking position.

  The heating discharge damper 55 is operated during the second heating operation, and the cooling discharge damper 57 is operated during the cooling operation. The heating discharge damper 55 can also be operated during the defrosting operation.

(1) Second Heating Operation First, the case where the heating discharge damper 55 is set at the blocking position will be described. In this case, one of outside air and inside air may be selectively supplied to the indoor evaporator 25, or a mixture of outside air and inside air may be supplied. When the outside air is supplied to the indoor evaporator 25, the indoor evaporator 25 functions as another outdoor heat exchanger, so that the performance of the vehicle air conditioner 1C can be improved. On the other hand, since the temperature of the inside air has already been adjusted by heating, if the inside air is discharged to the outside through another opening, the energy required to adjust the temperature of the inside air is wasted. On the other hand, if the inside air is supplied to the indoor evaporator 25 and deprived of heat from the inside air, the energy can be efficiently used.

  When the heating discharge damper 55 is set at a position other than the shut-off position and the heating exhaust port 54 is opened, the second heating operation described above and the second heating operation described in the first embodiment are combined.

(2) Defrosting operation In this embodiment, the following defrosting operation can be performed in addition to the defrosting operation described in the first embodiment.

  First, when the defrosting operation in which the outside air temperature is 0 ° C. or more described in the first embodiment is performed, outside air or a mixture of outside air and inside air is supplied to the indoor evaporator 25, and the heating exhaust damper 55 heats the exhaust. If the opening 54 is opened, the indoor heat exchange circuit 2 can realize a normal refrigeration cycle.

  Further, the three-way valve 41 is switched to the first state, the second expansion valve 32 is adjusted so that the refrigerant sucked into the compressor 21 is in a predetermined overheat state, and the first expansion valve 23 is moved from the outdoor heat exchanger 31. It adjusts so that the refrigerant | coolant which flows out may become a predetermined | prescribed overheating state. Then, by supplying outside air or a mixture of outside air and inside air to the indoor evaporator 25 and opening the heating exhaust port 54 by the heating discharge damper 55, heating can be performed while defrosting.

  Further, when performing the defrosting operation in which the three-way valve 41 described in the first embodiment is switched to the first state and the first expansion valve 23 is fully closed or controlled to a low opening degree, the heating discharge damper 55 is used for heating. The exhaust port 54 may be opened.

(3) Cooling operation In the cooling operation when the cooling exhaust port 56 is opened, various valves are controlled in the same manner as in the reheating and dehumidifying operation. That is, the first expansion valve 23 is not controlled to be fully closed or opened to a low degree, but is adjusted so that the refrigerant flowing out of the indoor condenser 22 is in a predetermined supercooled state. On the other hand, the second expansion valve 32 is adjusted so that the refrigerant sucked into the compressor 21 is in a predetermined overheated state.

  First, the case where the cooling discharge damper 57 is set at the blocking position will be described. In this case, either the outside air or the inside air may be selectively supplied to the indoor condenser 22 or a mixture of outside air and inside air may be supplied. When the outside air is supplied to the indoor condenser 22, the indoor condenser 22 works as another outdoor heat exchanger, so that the performance of the vehicle air conditioner 1C can be improved. On the other hand, since the temperature of the inside air is already adjusted by cooling, if the inside air is discharged to the outside through another opening, the energy required for adjusting the temperature of the inside air is wasted. On the other hand, if the inside air is supplied to the indoor condenser 22 and heated after being given heat, the energy can be efficiently utilized.

  When the cooling exhaust damper 57 is set at a position other than the shut-off position and the cooling exhaust port 56 is opened, the cooling operation described above and the cooling operation described in the first embodiment are combined.

  In addition, if the 1st expansion valve 23 is controlled to a full close or a low opening degree in the state which set the discharge damper 57 for cooling to the closed position, the air_conditionaing | cooling operation demonstrated in 1st Embodiment can also be performed.

<Modification>
In the above embodiment, both the heating exhaust port 54 and the cooling exhaust port 56 are provided in the duct 5, but only one of them may be provided in the duct 5.

  Further, the indoor heat exchange circuit 2 may be provided with an electromagnetic valve 26 that can be switched between the decompression state and the non-decompression state described in the second embodiment. An electromagnetic valve or an expansion valve that can be switched between a reduced pressure state and a closed state may be provided.

  Furthermore, the outside air introduced into the duct 5 can be heated or cooled using the inside air discharged outside the passenger compartment for ventilation. In order to realize this, for example, as shown in FIG. 8, the flow of the internal air exhausted outside the passenger compartment flows across the duct 5 immediately downstream of the external air inlet 5 a and the internal air inlet 5 b in the duct 5. The heat exchanger 9 may be arranged so as to form a path. The heat exchanger 9 is as described in the modification of the first embodiment.

1A to 1C Vehicle air conditioner 2 Indoor heat exchange circuit 21 Compressor 22 Indoor condenser 23 First expansion valve (first expansion mechanism)
24 On-off valve 25 Indoor evaporator 26 Solenoid valve (pressure reduction mechanism)
3 outdoor heat exchange path 3a one end 3b other end 31 outdoor heat exchanger 32 second expansion valve (second expansion mechanism)
4A 1st communication path 4B 2nd communication path 41 Three-way valve (flow path selection means)
DESCRIPTION OF SYMBOLS 5 Duct 5a Outside air introduction port 5b Inside air introduction port 5c Outlet 54 Heating exhaust port 55 Heating discharge damper 56 Cooling exhaust port 57 Cooling discharge damper

Claims (11)

A vehicle air conditioner capable of switching between heating operation, cooling operation and reheating dehumidification operation,
An indoor heat exchange circuit in which a compressor, an indoor condenser, a first expansion mechanism, and an indoor evaporator are connected in this order;
It has an outside air introduction port, an inside air introduction port, and an air outlet to the vehicle interior, and the indoor condenser and the indoor evaporator are arranged inside such that air that has passed through the indoor evaporator can pass through the indoor condenser. Arranged ducts,
An outdoor heat exchanger including an outdoor heat exchanger and a second expansion mechanism, one end of the second expansion mechanism side being connected to the indoor heat exchange circuit between the first expansion mechanism and the indoor evaporator;
A first communication path branched from the indoor heat exchange circuit between the compressor and the indoor condenser and connected to the other end of the outdoor heat exchange path on the outdoor heat exchanger side;
A second communication path branched from the indoor heat exchange circuit between the indoor evaporator and the compressor and connected to the other end of the outdoor heat exchange path;
An on-off valve disposed between a position where one end of the outdoor heat exchange path is connected in the indoor heat exchange circuit and a position where the second communication path branches;
During the cooling operation and the reheating and dehumidifying operation, the other end of the outdoor heat exchange path is switched to the first state that communicates with the indoor heat exchange circuit through the first communication path, and during the heating operation, A flow path selecting means switched to a second state in which the other end communicates with the indoor heat exchange circuit through the second communication path;
Bei to give a,
The heating operation includes a heating operation in which the on-off valve is opened,
An air conditioner for a vehicle in which air passes through the indoor evaporator and the indoor condenser in this order and is dehumidified during heating operation in which the on-off valve is opened .   The duct flows through an air passage that passes through the indoor condenser, an air passage that does not pass through the indoor condenser, an amount of air that flows through the air passage that passes through the indoor condenser, and an air passage that does not pass through the indoor condenser. The vehicle air conditioner of Claim 1 provided with the damper which adjusts a ratio with an airflow. The vehicle air conditioner according to claim 1 or 2 , wherein the on-off valve is disposed between a position where one end of the outdoor heat exchange path is connected and the indoor evaporator. Wherein in the indoor heat exchanger circuit inside evaporator and the second communication path is disposed between the position where the branch, further comprising a pressure reducing mechanism can be switched in a reduced pressure state and a non-vacuum state, according to claim 3 Vehicle air conditioner. The on-off valve is a decompression mechanism that is arranged between the indoor evaporator and the position where the second communication path branches in the indoor heat exchange circuit and can be switched between a decompression state, a non-decompression state, and a closed state. The vehicle air conditioner according to claim 1 or 2 , wherein the vehicle air conditioner is configured. The depressurization mechanism is switched to a non-depressurized state during the cooling operation and the reheating and dehumidifying operation, and when ice adheres to the indoor evaporator during the heating operation or under conditions where ice can adhere to the indoor evaporator in is switched to a reduced pressure state, air-conditioning system according to claim 4 or 5. The heating operation may further include a warm Boun rolling off valve is that closed,
Wherein the opening and closing valve is heating operation is opened, the refrigerant sucked into the compressor is adjusted the first expansion mechanism to a predetermined overheated state, according to any one of claims 1 to 6 Vehicle air conditioner. The duct is provided with a heating exhaust port for discharging the air cooled by the indoor evaporator to the outside of the passenger compartment during the heating operation in which the on- off valve is opened ,
A heating exhaust damper that opens and closes the heating exhaust port, and further includes a heating exhaust damper that guides air that has passed through the indoor evaporator to the heating exhaust port when the heating exhaust port is opened. Item 8. The vehicle air conditioner according to Item 7 . Wherein during cooling operation and the reheat dehumidification operation, the refrigerant sucked into the compressor the second expansion mechanism to a predetermined overheated state is adjusted, according to any one of claims 1-8 Vehicle air conditioner. The vehicle air conditioner according to claim 9 , wherein the first expansion mechanism is adjusted so that the refrigerant flowing out of the indoor condenser has a predetermined degree of supercooling during the cooling operation and the reheating and dehumidifying operation. The duct is provided with a cooling exhaust port for discharging the air heated by the indoor condenser during the cooling operation to the outside of the passenger compartment,
A cooling exhaust damper that opens and closes the cooling exhaust port, and further includes a cooling exhaust damper that guides air that has passed through the indoor condenser to the cooling exhaust port when the cooling exhaust port is opened. Item 11. The vehicle air conditioner according to any one of Items 1 to 10 .

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