Vehicle air conditioning device

Abstract

The vehicle air conditioner includes: a refrigeration cycle having a compressor, a condenser, an expansion valve, and an evaporator through which a refrigerant flows in sequence; a high-temperature heat medium circuit through which a high-temperature heat medium that has exchanged heat with the refrigerant in the condenser circulates; a low-temperature heat medium circuit through which a low-temperature heat medium that has exchanged heat with the refrigerant in the evaporator circulates; a connecting pipe connecting the high-temperature heat medium circuit and the low-temperature heat medium circuit; a plurality of outside vehicle heat exchangers into which the heat medium can be introduced; and a switching unit that can switch, for each of the plurality of outside vehicle heat exchangers, to a mode of connection to the high-temperature heat medium circuit, a mode of connection to the low-temperature heat medium circuit, and a mode of non-connection to either the high-temperature heat medium circuit or the low-temperature heat medium circuit.

Description

Technical Field

[0001] The present invention relates to an air conditioning device for a vehicle.

[0002] This application claims the priority of Japanese Patent Application No. 2020-15517 filed in Japan on January 31, 2020, and incorporates its content herein. Background Art

[0003] As an example of an air conditioning device for a vehicle mounted on a vehicle including an automobile and a truck, an air conditioning device for a vehicle described in Patent Document 1 below is known. The device described in Patent Document 1 includes: a refrigeration cycle having a compressor, an expansion valve, an evaporator (heat medium cooler) and a condenser (heat medium heater) and circulating a refrigerant; a first heat medium circuit for exchanging heat between the refrigerant and the heat medium by supplying a low-temperature heat medium to the evaporator; and a second heat medium circuit for exchanging heat between the refrigerant and the heat medium by supplying a high-temperature heat medium to a cooling water heater.

[0004] That is, each heat medium circuit forms an independent circulation path from the refrigeration cycle. Thus, while the refrigeration cycle can be completed outside the machine room, the thermal management of the vehicle can be performed.

[0005] During the operation of the vehicle air conditioning device connected to an outdoor heat exchanger that exchanges heat between the heat medium and external air (outdoor air of the machine room), when the external air temperature is above freezing and the temperature of the heat medium flowing in the radiator is below freezing, moisture in the air condensed on the surface of the outdoor heat exchanger sometimes freezes and frost adheres (frosting). If frosting progresses, it may hinder the ventilation performance of the radiator. Therefore, the device of Patent Document 1 employs the following structure: when frosting occurs, high-temperature cooling water is supplied to the radiator to remove the frost.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2014-234094 Summary of the Invention

[0009] Technical Problem to be Solved by the Invention

[0010] However, if a high-temperature heat medium is supplied to the radiator, the temperature of the heat medium becomes higher than the external air temperature, so heat cannot be absorbed from the external air. Thus, it may not be possible to perform heating operation based on a heat pump cycle.

[0011] The present invention has been completed to solve the above problems, and an object thereof is to provide an air conditioning device for a vehicle that can balance defrosting and heating operation.

[0012] Means for Solving Technical Problems

[0013] To solve the above problems, the vehicle air conditioner according to the present invention includes: a refrigeration cycle having a compressor, a condenser, an expansion valve, and an evaporator through which a refrigerant flows in sequence; a high-temperature heat medium circuit through which a high-temperature heat medium that has exchanged heat with the refrigerant in the condenser circulates; a low-temperature heat medium circuit through which a low-temperature heat medium that has exchanged heat with the refrigerant in the evaporator circulates; a connecting pipe connecting the high-temperature heat medium circuit and the low-temperature heat medium circuit; a plurality of outdoor heat exchangers into which the heat medium can be introduced; and a switching unit that can switch each of the plurality of outdoor heat exchangers to a mode of connection to the high-temperature heat medium circuit, a mode of connection to the low-temperature heat medium circuit, and a mode of non-connection to either the high-temperature heat medium circuit or the low-temperature heat medium circuit.

[0014] Advantages of the Invention

[0015] The vehicle air conditioner according to the present invention can balance defrosting and heating operations. Description of the Drawings

[0016] Figure 1 It is a system diagram showing the structure of the vehicle air conditioner according to the embodiment of the present invention, and is a diagram showing the operating state in the strong heating mode.

[0017] Figure 2 It is a system diagram showing the structure of the vehicle air conditioner according to the embodiment of the present invention, and is a diagram showing the state of defrosting the first outdoor heat exchanger in the heating defrosting mode.

[0018] Figure 3 It is a system diagram showing the structure of the vehicle air conditioner according to the embodiment of the present invention, and is a diagram showing the state of defrosting the second outdoor heat exchanger in the heating defrosting mode.

[0019] Figure 4 It is a cross-sectional view showing the structure of the valve device as the switching unit according to the embodiment of the present invention. [[ID=!29]]

[0020] Figure 5 It is Figure 4 a view in the direction of line A-A of

[0021] Figure 6 It is a schematic diagram showing the structure of the first communication path in the first valve element.

[0022] Figure 7 It is a perspective view showing the structure of the first valve element.

[0023] Figure 8It is a schematic diagram showing the structure of the second communication path in the second spool valve.

[0024] Figure 9 It is a perspective view showing the structure of the second spool valve.

[0025] Figure 10 It is a schematic diagram showing the structure of the third communication path in the third spool valve.

[0026] Figure 11 It is a perspective view showing the structure of the third spool valve.

[0027] Figure 12 It is a schematic diagram showing the structure of the fourth communication path in the fourth spool valve.

[0028] Figure 13 It is a perspective view showing the structure of the fourth spool valve. Detailed implementation mode

[0029] (Structure of vehicle air conditioner)

[0030] Hereinafter, with reference to Figures 1 to 13 , the vehicle air conditioner 100 according to the embodiment of the present invention will be described. The vehicle air conditioner 100 is mounted on transportation equipment (vehicles) such as automobiles and trucks. That is, the temperature difference between the inside and outside of the vehicle is adjusted by the vehicle air conditioner 100. As Figure 1 shown, the vehicle air conditioner 100 includes a refrigeration cycle 1, a high-temperature heat medium circuit 2, a low-temperature heat medium circuit 3, a first connection pipe 41, a second connection pipe 42, a third connection pipe 43, a fourth connection pipe 44, and a switching unit 5. In addition, in Figures 1 to 3 , the pipes in the open state are represented by solid lines, and the pipes in the cut-off state are represented by dotted lines.

[0031] The refrigeration cycle 1 has a refrigerant pipe 11 as a pipe for refrigerant to flow, a compressor 12, a condenser 13, an expansion valve 14, and an evaporator 15 arranged on the refrigerant pipe 11. These compressor 12, condenser 13, expansion valve 14, and evaporator 15 are arranged in sequence on the refrigerant pipe 11. And, when the refrigeration cycle 1 operates, the refrigerant also passes through each device in sequence.

[0032] The compressor 12 pressurizes and transports the refrigerant in the refrigerant pipe 11. Thus, the pressure and temperature of the refrigerant after passing through the compressor 12 increase compared with the refrigerant before passing through. The condenser 13 exchanges heat between the refrigerant flowing into the condenser 13 and the heat medium (described later) flowing in the high-temperature heat medium circuit 2. The expansion valve 14 sharply decreases the temperature by reducing the pressure of the refrigerant passing through the expansion valve 14. The evaporator 15 exchanges heat between the refrigerant flowing into the evaporator 15 and the heat medium (described later) flowing in the low-temperature heat medium circuit 3.

[0033] The high-temperature heat medium circuit 2 includes: a high-temperature heat medium pipeline 23 that introduces cooling water into the condenser 13; a heater core 21 and a cooler core 22 that are arranged in parallel with each other on the high-temperature heat medium pipeline 23; and a high-temperature heat medium pump 24 that pressurizes and transports the heat medium. That is, the heat medium flowing out from the condenser 13 can branch and flow into the heater core 21 and the cooler core 22 respectively. The heater core 21 and the cooler core 22 are heat exchangers arranged on the indoor side of the vehicle. The heater core 21 and the cooler core 22 exchange heat between the indoor air and the outdoor air and the heat medium. In addition, during the heating operation, the following operation can be performed: First, the air is cooled by the cooler core 22 to remove moisture, and then the air is heated by the heater core 21 to suppress the rise of indoor humidity while increasing the room temperature.

[0034] The low-temperature heat medium circuit 3 includes: a low-temperature heat medium pipeline 33 that introduces the heat medium into the evaporator 15; a first outdoor heat exchanger 31 and a second outdoor heat exchanger 32 that are arranged in parallel with each other on the low-temperature heat medium pipeline 33; and a low-temperature heat medium pump 34 that pressurizes and transports the heat medium. That is, the heat medium flowing out from the evaporator 15 can branch and flow into the first outdoor heat exchanger 31 and the second outdoor heat exchanger 32 respectively. These first outdoor heat exchanger 31 and second outdoor heat exchanger 32 are heat exchangers arranged on the outdoor side of the vehicle. The first outdoor heat exchanger 31 and the second outdoor heat exchanger 32 exchange heat between the outdoor air and the heat medium.

[0035] The first connecting pipeline 41 and the second connecting pipeline 42 are pipes connecting the high-temperature heat medium circuit 2 and the low-temperature heat medium circuit 3. That is, the heat medium flows through these first connecting pipeline 41 and second connecting pipeline 42. The first connecting pipeline 41 and the second connecting pipeline 42 are arranged in parallel. That is, the high-temperature heat medium circuit 2 and the low-temperature heat medium circuit 3 can be connected by at least one of these first connecting pipeline 41 and second connecting pipeline 42 according to the operating state (operation mode) of the vehicle air conditioner 100.

[0036] The third connecting pipe 43 and the fourth connecting pipe 44 are also pipes connecting the high-temperature heat medium circuit 2 and the low-temperature heat medium circuit 3. That is, the heat medium flows through these third connecting pipe 43 and fourth connecting pipe 44. The third connecting pipe 43 and the fourth connecting pipe 44 are arranged in parallel. That is, according to the operating state (operation mode) of the vehicle air conditioner 100, the high-temperature heat medium circuit 2 and the low-temperature heat medium circuit 3 can be connected by at least one of these third connecting pipe 43 and fourth connecting pipe 44 in addition to at least one of the above-mentioned first connecting pipe 41 and second connecting pipe 42. And, in the present embodiment, only on the third connecting pipe 43 is arranged a vehicle-mounted device 90 which is an auxiliary equipment of the vehicle. As an example of this vehicle-mounted device 90, specifically, a battery can be cited.

[0037] The path of the cooling water flowing through the high-temperature heat medium circuit 2, the low-temperature heat medium circuit 3, the first connecting pipe 41, the second connecting pipe 42, the third connecting pipe 43 and the fourth connecting pipe 44 can be switched by the switching unit 5. In other words, by switching the flow path of the cooling water, the operating state (operation mode) of the vehicle air conditioner 100 is switched.

[0038] The switching unit 5 is a valve device (switching valve) capable of switching the flow state of the heat medium between a plurality of flow paths connected thereto. As Figure 1 shown, in the present embodiment, one switching unit 5 is provided at each of a plurality of (8) connection parts connecting the respective flow paths. The switching unit 5 provided at the connection part on the side closer to the cooler core 22 among the two connection parts of the first connecting pipe 41 and the second connecting pipe 42 among these 8 switching units 5 is defined as the first valve device 51.

[0039] The switching units 5 provided at the two branch points between the heater core 21 and the cooler core 22 in the high-temperature heat medium circuit 2 are respectively defined as the second valve device 52 and the third valve device 53. The third valve device 53 is provided at the branch point on the side between the cooler core 22 and the condenser 13 and on the side where the above-mentioned high-temperature heat medium pump 24 is provided. The second valve device 52 is provided at the branch point on the side between the cooler core 22 and the condenser 13 and on the side where the above-mentioned high-temperature heat medium pump 24 is not provided.

[0040] The switching unit 5 provided at the connection part on the side closer to the cooler core 22 among the two connection parts of the third connecting pipe 43 and the fourth connecting pipe 44 is defined as the fourth valve device 54.

[0041] In the same manner, the switching unit 5 provided at the connection part on the side closer to the second outside vehicle heat exchanger 32 among the two connection parts of the first connecting pipe 41 and the second connecting pipe 42 is defined as the fifth valve device 55.

[0042] The switching units 5 provided at the two branch points between the first external heat exchanger 31 and the second external heat exchanger 32 in the low-temperature heat medium circuit 3 are respectively set as a sixth valve device 56 and a seventh valve device 57. The sixth valve device 56 is provided at the branch point between the first external heat exchanger 31 and the second external heat exchanger 32 and on the side where the low-temperature heat medium pump 34 is provided. The seventh valve device 57 is provided at the branch point between the first external heat exchanger 31 and the second external heat exchanger 32 and on the side where the low-temperature heat medium pump 34 is not provided.

[0043] The switching unit 5 provided at the connection part closer to the second external heat exchanger 32 among the two connection parts of the third connection pipe 43 and the fourth connection pipe 44 is set as an eighth valve device 58.

[0044] In Figures 1 to 3 the marks marked near each switching unit 5 indicate the open states of the respective switching units 5. Hereinafter, with reference to Figures 4 to 13 the specific structure of the switching unit 5 will be described, and with reference to the open states indicated by the respective marks, Figures 1 to 3 examples of the operation modes of the vehicle air conditioner 100 will be described.

[0045] (Structure of the switching unit)

[0046] As Figure 4 shown, the switching unit 5 has a plurality (4) of valve cores 6, a valve housing 7 that houses these valve cores 6 and forms a plurality (4) of flow paths 71, 72, 73, 74, and an actuator 8 that drives the valve cores 6.

[0047] Each valve core 6 is in a cylindrical shape extending along the axis O. Inside the valve housing 7, four valve cores 6 are arranged along the direction of the axis O. Each valve core 6 is driven by the actuator 8, whereby it can advance and retreat along the axis O inside the valve housing 7 and can rotate around the axis O. That is, by advancing and retreating the valve core 6 along the axis O direction, any one of the four valve cores 6 with different shapes can be selectively used. The detailed structure of each valve core 6 will be described later.

[0048] The valve housing 7 covers the four valve cores 6 from the outer peripheral side with respect to the axis O and is in a cylindrical shape. And, as Figure 5 shown, four flow paths 71, 72, 73, 74 that communicate with at least one of the above-mentioned high-temperature heat medium circuit 2 and low-temperature heat medium circuit 3 are formed in the valve housing 7. Each of the flow paths 71, 72, 73, 74 extends radially at intervals of 90° in the circumferential direction with the axis O as the center. The positions of each of the flow paths 71, 72, 73, 74 in the axis O direction are the same.

[0049] As Figure 6 and Figure 7As shown, in one of the four valve elements 6 (the first valve element 61), four opening portions (first opening portions H1) are formed which open in four directions at intervals of 90° in the circumferential direction with respect to the axis O. Further, a pair of the first opening portions H1 adjacent to each other in the circumferential direction among these four first opening portions H1 communicate with each other through a first communication path C1 formed inside the first valve element 61, respectively. Figure 6 Schematically shows the shape of the first valve element 61 and corresponds to the symbols described in Figures 1 to 3 . For example, in the first valve device 51, the second valve element 62 is selected, and according to the posture of the second valve element 62, the high-temperature heat medium circuit 2 is brought into a state of communicating with the first connection pipe 41 and the second connection pipe 42. In the following description, the type of the valve element 6 selected in this way and its posture are indicated by the markings in Figures 1 to 3 .

[0050] As Figure 8 and Figure 9 show, in one of the four valve elements 6 (the second valve element 62), three opening portions (second opening portions H2) are formed which open in three directions at intervals in the circumferential direction with respect to the axis O. Further, these three second opening portions H2 communicate with each other through a second communication path C2 formed inside the second valve element 62. In addition, the intervals in the circumferential direction between the respective second opening portions H2 are not uniform. That is, when viewed from the axis O direction, the second communication path C2 has a T shape. Therefore, only any three of the four flow paths 71, 72, 73, 74 are brought into a communicating state through the second valve element 62. Figure 8 Schematically shows the shape of the second valve element 62 and corresponds to the symbols described in Figures 1 to 3 .

[0051] As Figure 10 and Figure 11 show, in one of the four valve elements 6 (the third valve element 63), two opening portions (third opening portions H3) are formed which open in two directions at intervals of 180° in the circumferential direction with respect to the axis O. Further, these third opening portions H3 communicate with each other through a third communication path C3 formed inside the third valve element 63. Only any two of the four flow paths 71, 72, 73, 74 are brought into a communicating state through the third valve element 63. Figure 10 Schematically shows the shape of the third valve element 63 and corresponds to the symbols described in Figures 1 to 3 .

[0052] As Figure 12 and Figure 13As shown, in one of the four valve elements 6 (the fourth valve element 64), four openings (fourth openings H4) are formed which open in four directions at intervals of 90° in the circumferential direction with respect to the axis O. And, a pair of the fourth openings H4 located on both sides in the diametrical direction with respect to the axis O among these four fourth openings H4 communicate with each other through fourth communication paths C4 respectively formed inside the fourth valve element 64. The two fourth communication paths C4 are bent inside the fourth valve element 64 respectively so as not to interfere with each other in the direction of the axis O. In addition, in Figure 13 , in order to avoid complication of the drawing, only one of the fourth communication paths C4 is shown, and the illustration of the other fourth communication path C4 is omitted. Only any two of the four flow paths 71, 72, 73, 74 are in a communicating state through the fourth valve element 64. Figure 12 Schematically shows the shape of the fourth valve element 64 and corresponds to the symbols described in Figures 1 to 3 .

[0053] (Strong heating mode)

[0054] Next, with reference to Figure 1 , the operation in the "strong heating mode", which is one of the operation modes of the vehicle air conditioner 100, will be described. In addition, the flow paths of the refrigerant and the heat medium described below are realized by setting each switching unit 5 to the state shown by the markings in Figure 1 .

[0055] In this mode, in the high-temperature heat medium circuit 2, the heat medium circulates from the high-temperature heat medium pump 24 via the heater core 21 in the direction toward the condenser 13. In the refrigeration cycle 1, heat exchange occurs between the refrigerant in the refrigerant pipe 11 and the heat medium in the high-temperature heat medium pipe 23. That is, the heat medium is heated by absorbing heat from the refrigerant in the condenser 13. The heat of the heated heat medium is released from the heater core 21 and is sent as air flow by an indoor fan (not shown) disposed near the cooler core 22 to the interior of the vehicle.

[0056] And, at this time, in the low-temperature heat medium circuit 3, the heat medium that has exchanged heat with the refrigerant in the evaporator 15 is introduced into both of the two outdoor heat exchangers (the first outdoor heat exchanger 31 and the second outdoor heat exchanger 32). That is, the refrigerant is heated by absorbing heat from the heat medium in the evaporator 15. The heat of the heated refrigerant is transferred to the heat medium flowing in the high-temperature heat medium circuit 2 in the condenser 13 through the refrigeration cycle 1 (refrigerant pipe 11). As described above, in the strong heating mode, by introducing the heat medium into both of the two outdoor heat exchangers (the first outdoor heat exchanger 31 and the second outdoor heat exchanger 32), heat exchange can be promoted and the heating performance can be improved.

[0057] (Heating and defrosting mode)

[0058] Next, referring to Figure 2 , the operation in the "heating and defrosting mode", which is one of the operation modes of the vehicle air conditioner 100, will be described. In addition, the refrigerant and heat medium flow paths described below are realized by setting each switching unit 5 to the state indicated by the marks in Figure 2 .

[0059] In this mode, in the high-temperature heat medium circuit 2, in the same manner as in the strong heating mode, the heat medium circulates from the high-temperature heat medium pump 24 via the heater core 21 toward the condenser 13. In the refrigeration cycle 1, heat exchange occurs between the refrigerant in the refrigerant pipe 11 and the heat medium in the high-temperature heat medium pipe 23. That is, the heat medium is heated by absorbing heat from the refrigerant in the condenser 13. The heat of the heated cooling water is released from the heater core 21 and is sent as air supply to the interior by an indoor fan (not shown) disposed near the cooler core 22.

[0060] On the other hand, in the low-temperature heat medium circuit 3, the low-temperature heat medium that has exchanged heat with the refrigerant in the evaporator 15 is introduced only into one of the outside heat exchangers (the second outside heat exchanger 32). At this time, in the same manner as in the above heating mode, the refrigerant is heated by absorbing heat from the low-temperature heat medium in the evaporator 15. The heat of the heated refrigerant is transferred to the heat medium flowing in the high-temperature heat medium circuit in the condenser 13 through the refrigeration cycle 1 (refrigerant pipe 11). And the other (remaining) outside heat exchanger (the first outside heat exchanger 31) is connected to the high-temperature heat medium circuit 2 through the second connection pipe 42 and the fourth connection pipe 44. Thus, the relatively high-temperature heat medium flowing in the high-temperature heat medium circuit 2 flows into the first outside heat exchanger 31 through the fourth connection pipe 44. When frost adheres to the surface of the first outside heat exchanger 31 (in the case of frosting), the first outside heat exchanger 31 is heated by the high-temperature heat medium, thereby removing the frost. Then, the high-temperature heat medium returns to the high-temperature heat medium circuit 2 through the second connection pipe 42.

[0061] In addition, by adopting the path as shown in Figure 3 , conversely, heating can also be performed by the first outside heat exchanger 31 and defrosting can be performed by the second outside heat exchanger 32. As described above, in the heating and defrosting mode, while defrosting can be performed by one of the first outside heat exchanger 31 and the second outside heat exchanger 32, heating can be performed by the other.

[0062] (Function and effect)

[0063] As described above, according to the present embodiment, in the strong heating mode, for example, compared with a structure having only one outdoor heat exchanger, by introducing the heat medium into all of the first outdoor heat exchanger 31 and the second outdoor heat exchanger 32, the heating performance can be improved. Further, in the heating and defrosting mode, the heat medium is introduced only into a part of the outdoor heat exchangers, and the remaining outdoor heat exchangers are in a state of being connected to the high-temperature heat medium circuit 2. Here, the heat medium flowing in the high-temperature heat medium circuit 2 is relatively high-temperature compared with the heat medium flowing in the low-temperature heat medium circuit 3 and the remaining outdoor heat exchangers and has a temperature higher than the freezing point of water. Therefore, when frost forms on the remaining outdoor heat exchangers, defrosting can be performed with the high-temperature heat medium. As described above, it is possible to balance the heating operation based on one of the outdoor heat exchangers and the defrosting in the other outdoor heat exchanger.

[0064] Moreover, according to the above structure, the temperature of the heat medium introduced into all the outdoor heat exchangers is lower than the outside air temperature, whereby the heating performance can be further improved.

[0065] Furthermore, according to the above structure, the temperature of the heat medium introduced into the remaining outdoor heat exchangers is higher than the outside air temperature and higher than the freezing point of water, whereby defrosting in the remaining outdoor heat exchangers can be performed more quickly and efficiently.

[0066] Moreover, according to the above structure, by moving the plurality of valve elements 6 forward and backward or rotating around the axis O in the valve housing 7, the communication states of the plurality of flow paths 71, 72, 73, 74 can be switched. In particular, it is possible to unify only one structure for a plurality of required valve devices (conversion unit 5). Also, it is possible to easily increase the connection parts, so that the expandability of the device can be ensured. In addition, the process of selecting and installing a suitable type from a variety of valve devices during manufacturing can be omitted. As a result, the manufacturing cost and maintenance cost can be reduced.

[0067] According to the above structure, by using the first valve element 61, a pair of mutually adjacent flow paths among the four flow paths 71, 72, 73, 74 can be connected through the first communication path C1. Further, by rotating the first valve element 61 around the axis O, two of the four flow paths 71, 72, 73, 74 can be selectively connected. Thereby, the communication states of the flow paths 71, 72, 73, 74 can be switched with high degrees of freedom.

[0068] According to the above structure, by using the second valve element 62, three of the four flow paths 71, 72, 73, 74 can be connected to each other through the second communication path C2. Further, by rotating the second valve element 62 around the axis O, three of the four flow paths 71, 72, 73, 74 can be selectively connected. Thereby, the communication states of the flow paths 71, 72, 73, 74 can be switched with high degrees of freedom.

[0069] According to the above structure, by using the third spool valve 63, two of the four flow paths 71, 72, 73, and 74 can be connected to each other through the third communication path C3. Moreover, by rotating the third spool valve 63 about the axis O, two of the four flow paths 71, 72, 73, and 74 can be selectively connected. Thus, the connection state of the flow paths 71, 72, 73, and 74 can be converted with a high degree of freedom.

[0070] According to the above structure, by using the fourth spool valve 64, two flow paths located on both sides in the diametrical direction among the four flow paths 71, 72, 73, and 74 can be connected to each other through the fourth communication path C4. Moreover, by rotating the fourth spool valve 64 about the axis O, two of the four flow paths 71, 72, 73, and 74 can be selectively connected. Thus, the connection state of the flow paths 71, 72, 73, and 74 can be converted with a high degree of freedom.

[0071] (Other embodiments)

[0072] As described above, with reference to the drawings, the embodiments of the present invention have been described in detail. In addition, the specific structure is not limited to the above embodiments, and also includes design changes and the like within the scope not departing from the gist of the present invention. For example, in the vehicle air conditioner 100 described above, by appropriately switching the states of the respective switching units 5, it is possible to operate not only in the strong heating mode and the heating defrosting mode, but also in other modes including the refrigeration mode and the like.

[0073] <Note>

[0074] The vehicle air conditioner described in each embodiment is understood, for example, in the following manner.

[0075] (1) The vehicle air conditioner 100 according to the first mode includes: a refrigeration cycle 1 having a compressor 12, a condenser 13, an expansion valve 14, and an evaporator 15 through which a refrigerant circulates in sequence; a high-temperature heat medium circuit 2 through which a high-temperature heat medium that has exchanged heat with the refrigerant in the condenser 13 circulates; a low-temperature heat medium circuit 3 through which a low-temperature heat medium that has exchanged heat with the refrigerant in the evaporator 15 circulates; connecting pipes 41, 42, 43, 44 that connect the high-temperature heat medium circuit and the low-temperature heat medium circuit; a plurality of in-vehicle heat exchangers 21, 22 into which the heat medium can be introduced; a plurality of out-of-vehicle heat exchangers 31, 32 into which the heat medium can be introduced; and a switching unit 5 that can switch, for each of the plurality of out-of-vehicle heat exchangers, to a mode of being connected to the high-temperature heat medium circuit, a mode of being connected to the low-temperature heat medium circuit, and a mode of not being connected to either the high-temperature heat medium circuit or the low-temperature heat medium circuit.

[0076] According to the above structure, in the strong heating mode, for example, compared with the structure having only one outdoor heat exchanger, by introducing the cooling water into all of the first outdoor heat exchanger 31 and the second outdoor heat exchanger 32, the heating performance can be improved. Further, in the heating and defrosting mode, the low-temperature heat medium is introduced only into a part of the outdoor heat exchangers 31 and 32, and the remaining outdoor heat exchangers 31 and 32 are in a state of being connected to the high-temperature heat medium circuit 2. Here, the high-temperature heat medium flowing in the high-temperature heat medium circuit 2 is relatively high in temperature compared with the low-temperature heat medium flowing in the low-temperature heat medium circuit 3 and the remaining outdoor heat exchangers 31 and 32. Therefore, when frost forms on the remaining outdoor heat exchangers 31 and 32, defrosting can be performed by the high-temperature heat medium. As described above, according to the above structure, heating operation based on one of the outdoor heat exchangers 31 or 32 and defrosting in the other outdoor heat exchanger 32 or 31 can be performed simultaneously.

[0077] (2) In the vehicle air conditioner 100 according to the second mode, in the refrigeration cycle 1, in the strong heating mode, the temperature of the refrigerant is adjusted so that the temperature of the heat medium exchanging heat with the refrigerant in all of the outdoor heat exchangers 31 and 32 is lower than the outside air temperature.

[0078] According to the above structure, the temperature of the heat medium introduced into all of the outdoor heat exchangers 31 and 32 is lower than the outside air temperature, whereby the heating performance can be further improved.

[0079] (3) In the vehicle air conditioner 100 according to the third mode, in the refrigeration cycle 1, in the heating and defrosting mode, the temperature of the refrigerant is adjusted so that the temperature of the heat medium exchanging heat with the refrigerant in the remaining outdoor heat exchanger 31 or 32 is higher than the freezing point of water.

[0080] According to the above structure, the temperature of the heat medium introduced into the remaining outdoor heat exchanger 31 or 32 is higher than the freezing point of water, whereby defrosting in the remaining outdoor heat exchanger 31 or 32 can be performed more quickly and efficiently.

[0081] (4) In the vehicle air conditioner 100 according to the fourth mode, the switching unit 5 is a plurality of valve devices capable of changing the flow states of the high-temperature heat medium circuit 2 and the low-temperature heat medium circuit 3, and includes: a plurality of valve cores 6, which are cylindrical with the axis O as the center and are arranged along the direction of the axis O, and can rotate around the axis O; a valve housing 7, which covers the plurality of valve cores 6 and forms four flow paths 71, 72, 73, and 74 communicating with at least one of the high-temperature heat medium circuit 2 and the low-temperature heat medium circuit 3; and an actuator 8, which moves the plurality of valve cores 6 forward and backward along the direction of the axis O in the valve housing 7 and rotates around the axis O.

[0082] According to the above structure, a plurality of valve elements 6 are moved forward and backward or rotated around the axis O in the valve housing 7, thereby enabling the switching of the communication states of a plurality of flow paths 71, 72, 73, 74. In particular, a plurality of required valve devices can be unified into one structure. Moreover, the connection parts can be easily added, so the developability of the device can be ensured. In addition, the process of selecting and installing a suitable type from a variety of valve devices during manufacturing can be omitted. As a result, the manufacturing cost and maintenance cost can be reduced.

[0083] (5) In the vehicle air conditioner 100 according to the fifth aspect, one of the plurality of valve elements 6 is a first valve element 61. The first valve element 61 is formed with a first opening H1 that opens in four directions at intervals in the circumferential direction with respect to the axis O, and is formed with a first communication path C1 that connects a pair of the first openings H1 adjacent to each other in the circumferential direction inside the valve element 6.

[0084] According to the above structure, a pair of adjacent flow paths among the four flow paths 71, 72, 73, 74 can be connected through the first communication path C1. Moreover, by rotating the first valve element 61 around the axis O, two of the four flow paths 71, 72, 73, 74 can be selectively connected. Thus, the communication states of the flow paths 71, 72, 73, 74 can be switched with a high degree of freedom.

[0085] (6) In the vehicle air conditioner 100 according to the sixth aspect, one of the plurality of valve elements 6 is a second valve element 62. The second valve element 62 is formed with a second opening H2 that opens in three directions at intervals in the circumferential direction with respect to the axis O, and is formed with a second communication path C2 that connects the three second openings H2 inside the valve element 6.

[0086] According to the above structure, three of the four flow paths 71, 72, 73, 74 can be connected to each other through the second communication path C2. Moreover, by rotating the second valve element 62 around the axis O, three of the four flow paths 71, 72, 73, 74 can be selectively connected. Thus, the communication states of the flow paths 71, 72, 73, 74 can be switched with a high degree of freedom.

[0087] (7) In the vehicle air conditioner 100 according to the seventh aspect, one of the plurality of valve elements 6 is a third valve element 63. The third valve element 63 is formed with a third opening H3 that opens in two directions at intervals in the circumferential direction with respect to the axis O, and is formed with a third communication path C3 that connects the two third openings H3 inside the valve element 6.

[0088] According to the above structure, two of the four flow paths 71, 72, 73, and 74 can be interconnected through the third communication path C3. Moreover, by rotating the third valve element 63 about the axis O, two of the four flow paths 71, 72, 73, and 74 can be selectively communicated. Thus, the communication state of the flow paths 71, 72, 73, and 74 can be switched with a high degree of freedom.

[0089] (8) In the vehicle air conditioner 100 according to the eighth aspect, one of the plurality of valve elements 6 is a fourth valve element 64. The fourth valve element 64 is formed with a fourth opening portion H4 that opens in four directions at intervals in the circumferential direction with respect to the axis O, and is formed with a fourth communication path C4 that communicates a pair of the fourth opening portions H4 located on both sides in the diametrical direction with respect to the axis O inside the valve element.

[0090] According to the above structure, two of the four flow paths 71, 72, 73, and 74 located on both sides in the diametrical direction can be interconnected through the fourth communication path C4. Moreover, by rotating the fourth valve element 64 about the axis O, two of the four flow paths 71, 72, 73, and 74 can be selectively communicated. Thus, the communication state of the flow paths 71, 72, 73, and 74 can be switched with a high degree of freedom.

[0091] Symbolic description

[0092] 100 - Vehicle air conditioner, 1 - Refrigeration cycle, 2 - High-temperature heat medium circuit, 3 - Low-temperature heat medium circuit, 5 - Conversion unit, 6 - Valve element, 7 - Valve housing, 8 - Actuator, 11 - Refrigerant pipeline, 12 - Compressor, 13 - Condenser, 14 - Expansion valve, 15 - Evaporator, 21 - Heater core, 22 - Cooler core, 23 - High-temperature heat medium pipeline, 24 - High-temperature heat medium pump, 31 - First outdoor heat exchanger, 32 - Second outdoor heat exchanger, 33 - Low-temperature heat medium pipeline, 34 - Low-temperature heat medium pump, 41 - First connecting pipeline, 42 - Second connecting pipeline, ings, 43 - Third connecting pipeline, 44 - Fourth connecting pipeline, 51 - First valve device, 52 - Second valve device, 53 - Third valve device, 54 - Fourth valve device, 55 - Fifth valve device, 56 - Sixth valve device, 57 - Seventh valve device, 58 - Eighth valve device, 61 - First valve element, 62 - Second valve element, 63 - Third valve element, 64 - Fourth valve element, 71, 72, 73, 74 - Flow paths, 90 - Vehicle-mounted equipment, C1 - First communication path, C2 - Second communication path, C3 - Third communication path, C4 - Fourth communication path, H1 - First opening portion, H2 - Second opening portion, H3 - Third opening portion, H4 - Fourth opening portion, O - Axis.

Claims

1. An air conditioning device for a vehicle, comprising: A refrigeration cycle having a compressor, a condenser, an expansion valve, and an evaporator through which a refrigerant circulates in sequence; A high-temperature heat medium circuit through which a high-temperature heat medium that has exchanged heat with the refrigerant in the condenser circulates; A low-temperature heat medium circuit through which a low-temperature heat medium that has exchanged heat with the refrigerant in the evaporator circulates; A connecting pipe connecting the high-temperature heat medium circuit and the low-temperature heat medium circuit; A plurality of external heat exchangers capable of introducing the heat medium; And A switching unit that can switch, for each of a plurality of outside heat exchangers, to a mode of being connected to the high-temperature heat medium circuit via the connecting pipe, a mode of being connected to the low-temperature heat medium circuit via the connecting pipe, and a mode of not being connected to either the high-temperature heat medium circuit or the low-temperature heat medium circuit; The switching unit is a plurality of valve devices capable of changing the flow states of the high-temperature heat medium circuit and the low-temperature heat medium circuit, and has: A plurality of valve cores, which are cylindrical with an axis as the center and are arranged along the axis direction and can rotate around the axis; A valve housing that covers the plurality of valve cores and forms four flow paths that communicate with at least one of the high-temperature heat medium circuit and the low-temperature heat medium circuit; And An actuator that moves the plurality of valve cores forward and backward along the axis direction within the valve housing and rotates around the axis.

2. The air conditioning device for a vehicle according to claim 1, wherein In the refrigeration cycle, in the strong heating mode, the temperature of the refrigerant is adjusted to a state where the temperature of the heat medium that exchanges heat with the refrigerant in all the outside heat exchangers is lower than the outside air temperature.

3. The air conditioning device for a vehicle according to claim 1, wherein In the refrigeration cycle, in the heating and defrosting mode, the temperature of the refrigerant is adjusted to a state where the temperature of the heat medium that exchanges heat with the refrigerant in the outside heat exchanger connected to the high-temperature heat medium circuit is higher than the freezing point of water.

4. The air conditioning device for a vehicle according to any one of claims 1 to 3, wherein One of the plurality of valve cores is a first valve core, and the first valve core is formed with a first opening portion that opens in four directions at intervals in the circumferential direction with respect to the axis, and a first communication path that connects a pair of the first opening portions adjacent to each other in the circumferential direction inside the valve core.

5. The air conditioning device for a vehicle according to any one of claims 1 to 3, wherein One of the plurality of valve cores is a second valve core, and the second valve core is formed with a second opening portion that opens in three directions at intervals in the circumferential direction with respect to the axis, and a second communication path that connects the three second opening portions inside the valve core.

6. The air conditioning device for a vehicle according to any one of claims 1 to 3, wherein One of the plurality of valve cores is a third valve core, and the third valve core is formed with a third opening portion that opens in two directions at intervals in the circumferential direction with respect to the axis, and a third communication path that connects the two third opening portions inside the valve core.

7. The vehicle air-conditioning device according to any one of claims 1 to 3, wherein one of the plurality of valve elements is a fourth valve element, the fourth valve element is formed with a fourth opening portion that opens in four directions at intervals in the circumferential direction with respect to the axis, and is formed with a fourth communication path that communicates a pair of the fourth opening portions located on both sides in the diametrical direction with respect to the axis inside the valve element.

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