Composite device

Abstract

To provide a composite device that can contribute to downsizing of a vehicular air conditioner or the like and secure cooling (radiation) performance of a switching element that switches a DC voltage to an AC voltage.SOLUTION: A composite device 1, which has a refrigerant compressing function and a heat medium heating function, includes: a first housing 2A in which a compression mechanism 3 that compresses a refrigerant and an electric motor 4 that drives the compression mechanism 3 are housed in series; a second housing 2B in which an electric heater 5 that heats a heat medium is housed; and a third housing 2C in which a motor driving circuit 20 and a heater control circuit 30 are housed. In the third housing 2C, first power switching elements Q1-Q6 of the motor driving circuit 20 are arranged so that the elements can be cooled by refrigerants flowing through a refrigerant inflow port 8 into the first housing 2A and can be cooled by heat media flowing through a heat medium inflow port 10 into the second housing 2B.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a combined device having a refrigerant compressing function and a heat medium heating function. [Background technology]

[0002] Patent Document 1 describes a vehicle air conditioner applicable to vehicles such as hybrid vehicles and electric vehicles. The vehicle air conditioner described in Patent Document 1 has a refrigerant circuit including an electric compressor that compresses a refrigerant, a radiator that dissipates heat from the refrigerant discharged from the electric compressor to heat air supplied to the vehicle cabin, an expansion valve that reduces the pressure and expands the heat-dissipated refrigerant, and a heat exchanger equivalent to an evaporator that exchanges heat between the reduced-pressure and expanded refrigerant and outside air. The vehicle air conditioner described in Patent Document 1 also has a heat medium heating electric heater that heats the heat medium to assist the radiator in heating the vehicle cabin, and a heat medium-air heat exchanger that heats the air supplied to the vehicle cabin with the heated heat medium. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-213765 Summary of the Invention [Problem to be solved by the invention]

[0004] The vehicle air conditioning system described in Patent Document 1 can compensate for the lack of heating capacity provided by the radiator. However, the vehicle air conditioning system described in Patent Document 1 has an electric compressor, a heat medium heater, and other components separately provided. This makes the system larger overall, leaving room for improvement in terms of installation space, etc.

[0005] The present invention aims to provide a composite device that contributes to the miniaturization of vehicle air conditioning systems and the like, and that can ensure the cooling (heat dissipation) performance of a switching element that converts DC voltage into AC voltage. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided a hybrid device having a refrigerant compression function and a heat medium heating function, the hybrid device including: a compression mechanism that compresses a refrigerant, an electric motor that drives the compression mechanism, a compressor housing that houses the compression mechanism and the electric motor in series and has a refrigerant inlet through which the refrigerant compressed by the compression mechanism flows into the compressor housing and a refrigerant outlet through which the refrigerant compressed by the compression mechanism flows out to the outside, an electric heater that heats a heat medium, a heater housing that houses the electric heater and has a heat medium inlet through which the heat medium heated by the electric heater flows into the heater housing and a heat medium outlet through which the heat medium heated by the electric heater flows out to the outside, a motor drive circuit that controls the electric motor, a heater control circuit that controls the electric heater, and a circuit housing that houses the motor drive circuit and the heater control circuit, wherein the compressor housing, the heater housing, and the circuit housing are integrally connected. The motor drive circuit has a switching element that converts DC voltage to AC voltage, and within the circuit housing, the switching element of the motor drive circuit is arranged so that it can be cooled by the refrigerant that flows into the compressor housing and also by the heat medium that flows into the heater housing. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a composite device that contributes to the miniaturization of vehicle air conditioning devices and the like, and that can ensure the cooling (heat dissipation) performance of a switching element that converts DC voltage to AC voltage. [Brief explanation of the drawings]

[0008] [Figure 1]FIG. 1 is a front view of a multifunction device according to an embodiment. [Figure 2] FIG. 2 is a right side view of the multifunction peripheral according to the embodiment. [Figure 3] FIG. 2 is a top view of the multifunction device according to the embodiment. [Figure 4] 3 is a partial schematic cross-sectional view of the composite device according to the embodiment, which corresponds to the cross-sectional view taken along line AA in FIG. 2. FIG. [Figure 5] FIG. 2 is a diagram illustrating an example of the configuration of a main part of a motor drive circuit of a multifunction peripheral according to an embodiment. [Figure 6] FIG. 2 is a diagram illustrating an example of the configuration of a main part of a heater control circuit of a multifunction peripheral according to an embodiment. [Figure 7] 4 is a partial schematic cross-sectional view of the composite device according to the embodiment, which corresponds to the cross-sectional view taken along line BB in FIG. 3. FIG. [Figure 8] FIG. 2 is a block diagram showing a schematic configuration of a control system of the multifunction peripheral according to the embodiment. [Figure 9] 4 is a flowchart showing an example of operation control of a refrigerant compression function. [Figure 10] 4 is a flowchart showing an example of operation control of a refrigerant compression function. [Figure 11] 10 is a flowchart illustrating an example of operation control of a heat medium heating function. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0010] 1 to 4 show a schematic configuration of a composite device 1 according to an embodiment of the present invention. Fig. 1 is a front view of the composite device 1 according to the embodiment, Fig. 2 is a right side view of the composite device 1 according to the embodiment, Fig. 3 is a top view of the composite device 1 according to the embodiment, and Fig. 4 is a partial schematic cross-sectional view of the composite device according to the embodiment, which corresponds to the AA cross-sectional view of Fig. 2.

[0011] The composite device 1 according to the embodiment has a refrigerant compression function for compressing a refrigerant and a heat medium heating function for heating a heat medium separate from the refrigerant. In other words, the composite device 1 has a configuration in which a refrigerant compressor and a heat medium heating device are integrated.

[0012] The combined device 1 can be applied to the vehicle air conditioning system described above. That is, the combined device 1 can be incorporated into a refrigerant circuit through which a refrigerant circulates and a heat medium circuit through which a pump unit circulates a heat medium. The pump unit can be mainly composed of an electric pump. However, the pump unit is not limited to this, and can be any pump unit configured to circulate a heat medium within the heat medium circuit. For example, the refrigerant compression function unit of the combined device 1 can be incorporated into the refrigerant circuit and configured to compress refrigerant that has passed through an expansion valve and an evaporator (or an equivalent heat exchanger) and supply the compressed refrigerant to a radiator (refrigerant-air heat exchanger) that heats the air to be supplied into the vehicle cabin. Furthermore, the heat medium heating function unit of the combined device 1 can be incorporated into the heat medium circuit and configured to heat the heat medium that has passed through a heat medium-air heat exchanger that heats the air to be supplied into the vehicle cabin and supply the heated heat medium to the heat medium-air heat exchanger. The refrigerant and the heat medium can be selected arbitrarily. For example, a gas refrigerant can be used as the refrigerant, and a liquid can be used as the heat medium. Although not particularly limited, water (including water mixed with antifreeze) is usually used as the heat medium. Therefore, the heat medium heating function can also be called a water heating function.

[0013] 1 to 4, a compound device 1 has a housing 2. The housing 2 of the compound device 1 includes a first housing 2A, a second housing 2B, a third housing 2C, a first cover 2D, a second cover 2E, and a third cover 2F, which are integrally joined (fastened) together by fastening members such as bolts (not shown).

[0014] The first housing 2A is formed in a substantially cylindrical shape. A compression mechanism 3 that compresses a refrigerant and an electric motor 4 that drives the compression mechanism 3 are housed inside the first housing 2A in series in the axial direction. Although not particularly limited, the compression mechanism 3 may be a scroll compression mechanism including a fixed scroll and a movable (orbiting) scroll. An output shaft 4a of the electric motor 4 is connected to the compression mechanism 3 (for example, the movable (orbiting) scroll).

[0015] One of the two open ends of the first housing 2A (the lower open end in FIGS. 1 and 2), i.e., the open end of the first housing 2A on the compression mechanism 3 side, is closed by a first cover 2D. The first housing 2A, which houses the compression mechanism 3 and the electric motor 4 that drives it, can also be called a "compressor housing."

[0016] The second housing 2B is disposed to the side of the first housing 2A. The second housing 2B is formed in a substantially rectangular cylindrical shape. An electric heater 5 for heating a heat medium is accommodated inside the second housing 2B.

[0017] One of the two open ends of the second housing 2B (the lower open end in FIGS. 1 and 2) is closed by a second cover 2E. The second housing 2B that houses the electric heater 5 can also be called a "heater housing."

[0018] The third housing 2C is formed in a box shape with an open top. A motor drive circuit 20 that controls the electric motor 4 and a heater control circuit 30 that controls the electric heater 5 are housed inside the third housing 2C. Specifically, a circuit board 6 on which the motor drive circuit 20 and the heater control circuit 30 are mounted is housed inside the third housing 2C.

[0019] The bottom wall 7 of the third housing 2C closes the other open end of the first housing 2A (the upper open end in FIGS. 1 and 2), i.e., the open end of the first housing 2A facing the electric motor 4, and the other open end of the second housing 2B (the upper open end in FIGS. 1 and 2). This separates the interior of the first housing 2A from the interior of the third housing 2C, and separates the interior of the second housing 2B from the interior of the third housing 2C. In other words, the bottom wall 7 of the third housing 2C has a first partition 71 that separates the interior of the first housing 2A from the interior of the third housing 2C, and a second partition 72 that separates the interior of the second housing 2B from the interior of the third housing 2C. The first partition 71 and the second partition 72 are adjacent to each other.

[0020] The top surface (open end) of the third housing 2C is closed by a third cover 2F. The third housing 2C, which houses the motor drive circuit 20 and the heater control circuit 30, can also be called a "circuit housing."

[0021] In the combined device 1, the refrigerant compression function (refrigerant compressor) is realized mainly by the compression mechanism 3, the electric motor 4, and the motor drive circuit 20, and the heat medium heating function (heat medium heating device) is realized mainly by the electric heater 5 and the heater control circuit 30.

[0022] The first housing 2A is formed with a refrigerant inlet 8 for allowing the refrigerant circulating through the refrigerant circuit to flow into the interior. The refrigerant to be introduced is, for example, a refrigerant that has passed through an expansion valve and an evaporator (or an equivalent heat exchanger), i.e., a low-temperature, low-pressure refrigerant. In this embodiment, the refrigerant inlet 8 is provided in a portion of the first housing 2A on the third housing 2C side, i.e., near a first partition 71 that separates the interior of the first housing 2A from the interior of the third housing 2C. Preferably, the refrigerant inlet 8 is configured to allow the refrigerant circulating through the refrigerant circuit to flow into the first housing 2A so that at least a portion of the refrigerant flows along the first partition 71.

[0023] The (low-temperature, low-pressure) refrigerant that flows into the first housing 2A through the refrigerant inlet 8 flows inside the first housing 2A and is drawn into the compression mechanism 3. The refrigerant drawn into the compression mechanism 3 is compressed by the compression mechanism 3 and becomes high-temperature, high-pressure refrigerant, which is then discharged from the compression mechanism 3. The discharged (high-temperature, high-pressure) refrigerant flows out from a refrigerant outlet 9 formed in the first housing 2A and is supplied to, for example, the above-mentioned radiator (refrigerant-air heat exchanger).

[0024] In this embodiment, the refrigerant outlet 9 is provided in a portion of the first housing 2A on the first cover 2D side, i.e., in a position spaced apart in the up-down direction in Figures 1 and 2 from the refrigerant inlet 8. Therefore, in this embodiment, the refrigerant that flows into the first housing 2A from the refrigerant inlet 8 flows inside the first housing 2A from the top to the bottom in Figures 1 and 2.

[0025] The first partition 71 can be cooled by the (low-temperature, low-pressure) refrigerant flowing into the first housing 2A through the refrigerant inlet 8, and the electric motor 4 can be cooled by the refrigerant flowing inside the first housing 2A. The refrigerant inlet 8, the interior of the first housing 2A, and the refrigerant outlet 9 constitute a part of the refrigerant circuit.

[0026] The second housing 2B is formed with a heat medium inlet 10 for allowing the heat medium circulating through the heat medium circuit to flow into the second housing 2B. The heat medium to be introduced is, for example, a heat medium that has passed through the heat medium-air heat exchanger described above, i.e., a low-temperature heat medium. In this embodiment, the heat medium inlet 10 is provided in a portion of the second housing 2B on the third housing 2C side, that is, near the second partition 72 that separates the interior of the second housing 2B from the interior of the third housing 2C, and on the far side in FIG. 1 (the right side in FIG. 2). Preferably, the heat medium inlet 10 is configured to allow the heat medium circulating through the heat medium circuit to flow into the second housing 2B so that at least a portion of the heat medium flows along the second partition 72.

[0027] The (low temperature) heat medium that has flowed into the second housing 2B through the heat medium inlet 10 flows inside the second housing 2B, and is heated by the electric heater 5 during this process. The heated heat medium flows out from the heat medium outlet 11 formed in the second housing 2B and is supplied to, for example, the heat medium-air heat exchanger described above.

[0028] In this embodiment, the heat medium outlet 11 is provided near the second partition 72 that separates the interior of the second housing 2B from the interior of the third housing 2C and on the near side in Fig. 1 (left side in Fig. 2). Therefore, in this embodiment, the heat medium that flows into the second housing 2B from the heat medium inlet 10 flows inside the second housing 2B along the second partition 72 from right to left in Figs. 2 and 4.

[0029] The second partition 72 can be cooled by a (low-temperature) heat medium flowing into the second housing 2B through the heat medium inlet 10. The heat medium inlet 10, the interior of the second housing 2B, and the heat medium outlet 11 form part of the heat medium circuit.

[0030] Although not shown in the figure, the power supply line from the motor drive circuit 20 to the electric motor 4 and the power supply line from the heater control circuit 30 to the electric heater 5 each extend through the bottom wall 7 of the third housing 2C in an airtight and liquidtight manner.

[0031] Next, the motor drive circuit 20 that controls (drives) the electric motor 4 and the heater control circuit 30 that controls the electric heater 5 will be described with reference to FIGS.

[0032] 5 is a diagram showing an example of the configuration of the main parts of the motor drive circuit 20. In this embodiment, the motor drive circuit 20 is configured to control (drive) the electric motor 4 by converting a DC voltage from an external power supply into a three-phase AC voltage and supplying the AC voltage to the electric motor 4. The motor drive circuit 20 has a smoothing unit 21, a first power module 22, and a first driver circuit 23.

[0033] The smoothing unit 21 is connected between the power supply line and the ground line of the external power supply, and smooths the DC voltage from the external power supply. Although not particularly limited, the smoothing unit 21 may be composed of, for example, a plurality of electrolytic capacitors.

[0034] The first power module 22 includes six power switching elements (hereinafter referred to as "first power switching elements") Q1 to Q6 and six diodes D1 to D6. Although not particularly limited, the first power switching elements Q1 to Q6 may be IGBTs (insulated gate bipolar transistors). By PWM-controlling the first power switching elements Q1 to Q6, the first power module 22 converts the DC voltage from an external power supply, which has been smoothed by the smoothing unit 21, into a three-phase AC voltage and supplies it to the electric motor 4.

[0035] Specifically, the first power module 22 has a U-phase arm, a V-phase arm, and a W-phase arm that are provided in parallel with one another between the power supply line of the external power supply and the ground line.

[0036] Two first power switching elements Q1 and Q2 are connected in series to the U-phase arm, and diodes D1 and D2 are connected in antiparallel to the first power switching elements Q1 and Q2, respectively.

[0037] Two first power switching elements Q3 and Q4 are connected in series to the V-phase arm, and diodes D3 and D4 are connected in antiparallel to each of the first power switching elements Q3 and Q4, respectively.

[0038] Two first power switching elements Q5 and Q6 are connected in series to the W-phase arm, and diodes D5 and D6 are connected in antiparallel to each of the first power switching elements Q5 and Q6, respectively.

[0039] The midpoints of the U-, V-, and W-phase arms are connected at one end to the other end of the star-connected U-, V-, and W-phase coils of the electric motor 4. That is, the midpoints of power switching elements Q1 and Q2 of the U-phase arm are connected to the U-phase coil, the midpoints of power switching elements Q3 and Q4 of the V-phase arm are connected to the V-phase coil, and the midpoints of power switching elements Q5 and Q6 of the W-phase arm are connected to the W-phase coil.

[0040] Therefore, by controlling (PWM-controlled) the ratio between the ON period of the first power switching elements Q1, Q3, Q5 on the power line side of each phase arm and the ON period of the first power switching elements Q2, Q4, Q6 on the ground line side, the first power module 22 can convert the DC voltage from the external power source smoothed by the smoothing unit 21 into a three-phase AC voltage and supply it to the electric motor 4, thereby driving the electric motor 4 and the compression mechanism 3.

[0041] The first driver circuit 23 drives (PWM control) the first power switching elements Q1 to Q6 to turn them on and off based on a control signal (PWM signal) from a control unit 15 of the compound apparatus 1, which will be described later.

[0042] That is, in this embodiment, the control unit 15 controls the operation of the motor drive circuit 20 (first power switching elements Q1 to Q6), and further the operation of the electric motor 4 and the compression mechanism 3 (refrigerant compression function).

[0043] 6 is a diagram showing an example of the configuration of the main parts of the heater control circuit 30. In this embodiment, the heater control circuit 30 is configured to apply the voltage of the high-voltage power supply to the electric heater 5, and has a second power module 31 and a second driver circuit 32.

[0044] The second power module 31 includes two power switching elements (hereinafter referred to as "second power switching elements") Q7, Q8 that control the supply of electricity to the electric heater 5. The second power switching elements Q7, Q8 may be IGBTs, similar to the first power switching elements Q1 to Q6 of the motor drive circuit 20. In this embodiment, of the two second power switching elements Q7, Q8, one second power switching element Q7 is provided on the output side (voltage side) of the high-voltage power supply relative to the electric heater 5, and the other second power switching element Q8 is provided on the ground side of the high-voltage power supply relative to the electric heater 5.

[0045] The second power module 31 controls the second power switching elements Q7 and Q8 (PMW control) to turn on / off the power supply to the electric heater 5, thereby controlling the temperature of the electric heater 5 and further the temperature of the heat medium heated by the electric heater 5.

[0046] The second driver circuit 32 drives (PWM control) the second power switching elements Q7 and Q8 to turn them on and off based on a control signal (PWM signal) from a control unit 15 of the compound apparatus 1, which will be described later.

[0047] That is, in this embodiment, the control unit 15 controls the operation of the heater control circuit 30 (second power switching elements Q7, Q8), and further the operation of the electric heater 5 (heat medium heating function).

[0048] Here, the arrangement structure of the first power switching elements Q1 to Q6 of the motor drive circuit 20 and the second power switching elements Q7 and Q8 of the heater control circuit 30 in the compound device 1 according to this embodiment will be described with reference to Fig. 7. Fig. 7 is a partial schematic cross-sectional view of the compound device 1 (corresponding to the cross-sectional view taken along line BB in Fig. 3).

[0049] As described above, the motor drive circuit 20 and the heater control circuit 30 are mounted on the circuit board 6 and housed inside the third housing 2C. As shown in Fig. 7, the circuit board 6 can be attached to a plurality of board mounting portions 12 provided inside the third housing 2C. In this embodiment, each of the plurality of board mounting portions 12 is formed in the shape of a boss protruding from the bottom wall 7 of the third housing 2C (in a direction away from the first housing 2A and the second housing 2B), and the circuit board 6 is attached to the upper surface of the plurality of board mounting portions 12 with screws 13.

[0050] The first power switching elements Q1 to Q6 of the motor drive circuit 20 and the second power switching elements Q7 and Q8 of the heater control circuit 30 are arranged in positions within the third housing 2C where they can be cooled by the refrigerant flowing into the first housing 2A from the refrigerant inlet 8 and the heat medium flowing into the second housing 2B from the heat medium inlet 10.

[0051] Specifically, the first power switching elements Q1 to Q6 of the motor drive circuit 20 are mounted on the surface of the circuit board 6 attached to the board mounting portion 12 on the bottom wall 7 side of the third housing 2C, and each is in thermal contact with a portion of the first partition portion 71 on the second partition portion 72 side, preferably a portion adjacent (via a boundary) to the second partition portion 72 of the first partition portion 71.

[0052] In addition, the second power switching elements Q7 and Q8 of the heater control circuit 30 are mounted on the surface of the circuit board 6 attached to the board mounting portion 12 on the bottom wall 7 side of the third housing 2C, and are each in thermal contact with a portion of the second partition portion 72 on the first partition portion 71 side, preferably a portion of the second partition portion 72 adjacent to the first partition portion 71 (via a boundary).

[0053] Note that "in thermal contact with X" means being in a state where heat exchange with X is possible, and includes direct contact with X, proximity to X, and indirect contact with X via a heat exchange member with high thermal conductivity.

[0054] 8 is a block diagram showing a schematic configuration of a control system of the compound device 1 according to the embodiment. The compound device 1 has a control unit 15 that controls the overall operation of the compound device 1. In this embodiment, a command to activate / stop the refrigerant compression function, a command to activate / stop the heat medium heating function, etc. are input to the control unit 15 from a higher-level control device (for example, the control device of the above-mentioned vehicle air conditioner).

[0055] Control unit 15 also receives detection signals from various detectors, such as a rotation speed detector 51 that detects the rotation speed of electric motor 4, a first temperature detector 52 that detects the temperature of first power switching elements Q1-Q6, and a second temperature detector 53 that detects the temperature of second power switching elements Q7, Q8. Rotation speed detector 51 may calculate the rotation speed of electric motor 4. First temperature detector 52 may detect a value correlated with the temperature of first power switching elements Q1-Q6, and second temperature detector 53 may detect a value correlated with the temperature of second power switching elements Q7, Q8.

[0056] Furthermore, in this embodiment, the control unit 15 is communicably connected to a pump control device 60 that controls the pump section that circulates the heat medium within the heat medium circuit, and is configured to be able to operate the pump section via the pump control device 60, i.e., circulate the heat medium within the heat medium circuit, by outputting an operation request for the pump section (hereinafter referred to as a "pump operation request") to the pump control device 60.

[0057] The control unit 15 is configured to control the operation of the refrigerant compression function and the heat medium heating function of the combined device 1 based on commands from the higher-level control device and detection results from the various detection units. The operation control of the refrigerant compression function and the heat medium heating function by the control unit 15 will be described below.

[0058] 9 and 10 are flowcharts showing an example of the operational control of the refrigerant compression function by the control unit 15. In FIG.

[0059] In step S1, the control unit 15 determines whether or not an operation command for the refrigerant compression function has been input. If an operation command for the refrigerant compression function has been input (step S1; YES), the control unit 15 proceeds to the processing of step S2.

[0060] In step S2, the control unit 15 activates the refrigerant compression function. That is, the control unit 15 drives the first power switching elements Q1 to Q6 to turn ON / OFF by outputting a control signal (PWM signal) corresponding to an operation command of the refrigerant compression function to the first driver circuit 23, thereby operating the electric motor 4 and activating the refrigerant compression function.

[0061] In step S3, the control unit 15 determines whether the rotation speed of the electric motor 4 (hereinafter referred to as "motor rotation speed") is equal to or less than a predetermined rotation speed. If the motor rotation speed exceeds the predetermined rotation speed (step S3; NO), the control unit 15 proceeds to the processing of step S4.

[0062] In step S4, the control unit 15 determines whether or not a command to stop the refrigerant compression function has been input. If a command to stop the refrigerant compression function has been input (step S4; YES), the control unit 15 proceeds to the process of step S5, and if a command to stop the refrigerant compression function has not been input (step S4; NO), the control unit 15 returns to the process of step S2.

[0063] In step S5, the control unit 15 stops the operation of the refrigerant compression function. That is, the control unit 15 stops the output of the control signal (PWM signal) to the first driver circuit 23, thereby stopping the electric motor 4 and stopping the operation of the refrigerant compression function. Then, when the operation of the refrigerant compression function is stopped, the control unit 15 ends this flow.

[0064] In the process of step S3, if the motor rotation speed is equal to or lower than the predetermined rotation speed (step S; YES), that is, if the electric motor 4 is operating at a low rotation speed equal to or lower than the predetermined rotation speed, the control unit 15 proceeds to the process of step S6.

[0065] In step S6, the control unit 15 detects the temperatures of the first power switching elements Q1 to Q6 (hereinafter referred to as "first switching element temperatures"). This detection is performed based on the detection signal of the first temperature detection unit 52.

[0066] In step S7, the control unit 15 determines whether the first switching element temperature detected in step S6 is equal to or higher than a first threshold temperature. If the first switching element temperature is lower than the first threshold temperature (step S7; NO), the control unit 15 proceeds to the process of step S4, and if the first switching element temperature is equal to or higher than the first threshold temperature (step S7; YES), the control unit 15 proceeds to the process of step S8.

[0067] In step S8, the control unit 15 determines whether the first switching element temperature detected in step S6 is equal to or higher than the second threshold temperature (>first threshold temperature). If the first switching element temperature is lower than the second threshold temperature (step S8; NO), the control unit 15 proceeds to the process of step S9.

[0068] In step S9, the control unit 15 outputs the pump operation request to the pump control device 60. As a result, the pump section operates and the heat medium circulates within the heat medium circuit (i.e., the heat medium flows inside the second housing 2B).

[0069] In step S10, the control unit 15 determines whether or not a command to stop the refrigerant compression function has been input. If a command to stop the refrigerant compression function has been input (step S10; YES), the control unit 15 proceeds to step S11, outputs a cancellation of the pump operation request to the pump control device 60, and then proceeds to the processing of step S5. That is, the control unit 15 stops the operation of the refrigerant compression function. On the other hand, if a command to stop the refrigerant compression function has not been input (step S11; NO), the control unit 15 returns to the processing of step S6.

[0070] If, in the process of step S8, the first switching element temperature is equal to or higher than the second threshold temperature (step S8; YES), the control unit 15 proceeds to the process of step S12 and forcibly stops the operation of the refrigerant compression function. That is, the control unit 15 immediately stops outputting the control signal (PWM signal) to the first driver circuit 23. This is to protect the first power switching elements Q1 to Q6 from overheating. Then, after forcibly stopping the operation of the refrigerant compression function, the control unit 15 ends this flow. Note that, if the pump operation request has already been output to the pump control device 60, the control unit 15 outputs a cancellation of the pump operation request to the pump control device 60.

[0071] FIG. 11 is a flowchart showing an example of the operational control of the heat medium heating function by the control unit 15.

[0072] In step S21, the control unit 15 determines whether or not an operation command for the heat medium heating function has been input. If an operation command for the heat medium heating function has been input (step S21; YES), the control unit 15 proceeds to the processing of step S22.

[0073] In step S22, the control unit 15 activates the heat medium heating function. That is, the control unit 15 outputs a control signal (PWM signal) corresponding to an operation command for the heat medium heating function to the second driver circuit 32 to drive the second power switching elements Q7 and Q8 to turn on and off, thereby operating the electric heater 5 and activating the heat medium heating function.

[0074] In step S23, the control unit 15 detects the temperatures of the second power switching elements Q7 and Q8 (hereinafter referred to as the “second switching element temperature”). This detection is performed based on the detection signal of the second temperature detection unit 53.

[0075] In step S24, the control unit 15 determines whether the second switching element temperature detected in step S23 is equal to or higher than the third threshold temperature. If the third switching element temperature is lower than the third threshold temperature (step S24; NO), the control unit 15 proceeds to the process of step S25.

[0076] In step S25, the control unit 15 determines whether or not a command to stop the heat medium heating function has been input. If a command to stop the heat medium heating function has not been input (step S25; NO), the control unit 15 returns to the processing of step S23. On the other hand, if a command to stop the heat medium heating function has been input (step S25; YES), the control unit 15 proceeds to the processing of step S26.

[0077] In step S26, the control unit 15 stops the operation of the heat medium heating function. That is, the control unit 15 stops the output of the control signal (PWM signal) to the second driver circuit 32, thereby stopping the electric heater 5 and stopping the operation of the heat medium heating function. Then, when the operation of the heat medium heating function is stopped, the control unit 15 ends this flow.

[0078] If the third switching element temperature is equal to or higher than the third threshold temperature in the process of step S24 (step S24; YES), the control unit 15 proceeds to the process of step S27 and forcibly stops the operation of the heat medium heating function. That is, the control unit 15 immediately stops outputting the control signal (PWM signal) to the second driver circuit 32. This is to protect the second power switching elements Q7 and Q8 from overheating. Then, after forcibly stopping the operation of the heat medium heating function, the control unit 15 ends this flow.

[0079] The composite device 1 according to the embodiment provides the following advantages.

[0080] The combined device 1 includes a first housing (compressor housing) 2A that houses, in series, a compression mechanism 3 that compresses a refrigerant and an electric motor 4 that drives the compression mechanism 3, a second housing (heater housing) 2B that houses an electric heater 5 that heats a heat medium, and a third housing (circuit housing) 2C that houses a motor drive circuit 20 that controls the electric motor 4 and a heater control circuit 30 that controls the electric heater 5. The first housing 2A has a refrigerant inlet 8 through which the refrigerant compressed by the compression mechanism 3 flows into the inside and a refrigerant outlet 9 through which the refrigerant compressed by the compression mechanism 3 flows out to the outside, while the second housing 2B has a heat medium inlet 10 through which the heat medium to be heated by the electric heater 5 flows into the inside and a heat medium outlet 11 through which the heat medium heated by the electric heater 5 flows out to the outside. The first housing 2A, the second housing 2B, and the third housing 2C are integrally joined.

[0081] Such a combined device 1 can function as a refrigerant compressor (electric compressor) that compresses a refrigerant and a heat medium heating device that heats a heat medium, and can heat the heat medium while compressing the refrigerant. Therefore, the combined device 1 can be applied to the vehicle air conditioning system described above. By applying the combined device 1 to a vehicle air conditioning system, it is possible to reduce the size of the vehicle air conditioning system compared to a conventional configuration that has an electric compressor and a heat medium heating device separately.

[0082] Furthermore, within the third housing 2C, first power switching elements Q1 to Q6 of motor drive circuit 20 are arranged so as to be cooled by the refrigerant that has flowed into the first housing 2A and the heat medium that has flowed into the second housing 2B. Specifically, first power switching elements Q1 to Q6 are arranged so as to be in thermal contact with a portion of first partition 71 that separates the interior of first housing 2A from the interior of third housing 2C, on the side of second partition 72 that separates the interior of second housing 2B from the interior of third housing 2C. Refrigerant inlet 8 of first housing 2A is provided near first partition 71, and heat medium inlet 10 of second housing 2B is provided near second partition 72.

[0083] The portion of first partition 71 facing second partition 72 is cooled not only by the refrigerant flowing into first housing 2A, but also by the heat medium flowing into second housing 2B. Therefore, first power switching elements Q1 to Q6 are cooled by heat exchange with the portion of first partition 71 facing second partition 72, which can be cooled by the refrigerant flowing into first housing 2A and the heat medium flowing into second housing 2B. This ensures the cooling (heat dissipation) performance of first power switching elements Q1 to Q6.

[0084] Furthermore, when the electric motor 4 (i.e., the refrigerant compression function) is operating at a low rotation speed below a predetermined rotation speed, the control unit 15 outputs the pump operation request to the pump control device 60 that controls the pump section that circulates the heat medium within the heat medium circuit, thereby operating the pump section to flow the heat medium inside the second housing 2B.

[0085] When the electric motor 4 is operating at low speed, the amount of refrigerant flowing into the first housing 2A decreases, reducing the refrigerant's ability to cool the first partition 71 and, ultimately, the first power switching elements Q1-Q6. In this embodiment, when the electric motor 4 is operating at low speed, the pump operation request is output to the pump control device 60, causing the heat medium to flow into the second housing 2B. This causes the heat medium to cool the portion of the first partition 71 facing the second partition 72, thereby enabling the heat medium to cool the first power switching elements Q1-Q6. In other words, the reduction in the refrigerant's ability to cool the first power switching elements Q1-Q6 can be compensated for by the heat medium cooling. Therefore, the cooling (heat dissipation) performance of the first power switching elements Q1-Q6 is ensured even when the electric motor 4 is operating at low speed.

[0086] Furthermore, when the temperatures of the first power switches Q1 to Q6 are higher than a first threshold temperature, the control unit 15 is configured to output the pump operation request to the pump control device 60. This makes it possible to effectively and efficiently compensate for the decline in the cooling performance of the refrigerant for the first power switches Q1 to Q6 by cooling with the heat medium.

[0087] Furthermore, the control unit 15 is configured to forcibly stop the operation of the refrigerant compression function (electric motor 4) when the temperature of the first power switching elements Q1 to Q6 becomes equal to or higher than a second threshold temperature (>first threshold temperature), thereby protecting the first power switching elements Q1 to Q6 from overheating.

[0088] In the above-described embodiment, the control unit 15 outputs the pump operation request to the pump control device 60. However, this is not limited to this. The control unit 15 may be configured to output the pump operation request to a control device other than the pump control device 60 (for example, the higher-level control device), and the higher-level control device may issue an operation command for the pump section to the pump control device 60. In other words, the pump control device 60 may operate the pump section based on the pump operation request output from the control unit 15, and "outputting the pump operation request to the pump control device 60" includes indirectly outputting the pump operation request to the pump control device 60 via another control device, etc.

[0089] Furthermore, the control unit 15 may change (the content of) the pump operation request in accordance with the temperatures of the first power switching elements Q1 to Q6. For example, the pump operation request may include flow rate information of the heat medium circulating through the heat medium circuit, and the control unit 15 may output the pump operation request to the pump control device 60 such that the flow rate of the heat medium circulating through the heat medium circuit (i.e., the flow rate of the heat medium flowing inside the second housing 2B) increases as the temperatures of the first power switching elements Q1 to Q6 increase.

[0090] In the above-described embodiment, the motor drive circuit 20 and the heater control circuit 30 are mounted on one circuit board 6. However, this is not limited to this. The motor drive circuit 20 and the heater control circuit 30 may be mounted on separate circuit boards, or the motor drive circuit 20 and / or the heater control circuit 30 may be divided and mounted on multiple circuit boards.

[0091] The above description mainly focuses on the case where the combined device 1 is applied to a vehicle air conditioning system. However, the combined device 1 is not limited to this. The combined device 1 can be applied to various devices and systems that use an electric compressor for compressing a refrigerant and a heat medium heater for heating a heat medium.

[0092] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that modifications and changes can be made based on the technical concept of the present invention. [Explanation of symbols]

[0093] REFERENCE SIGNS LIST 1...combined device, 2...housing, 2A...first housing (compressor housing), 2B...second housing (heater housing), 2C...third housing (circuit housing), 3...compression mechanism, 4...electric motor, 5...electric heater, 6...circuit board, 7...bottom wall, 8...refrigerant inlet, 9...refrigerant outlet, 10...heat medium inlet, 11...heat medium outlet, 15...control unit, 20...motor drive circuit, 30...heater control circuit, 51...rotation speed detection unit, 52...first temperature detection unit, 53...second temperature detection unit, 60...pump control device, 71...first partition, 72...second partition, Q1 to Q6...first power switching element (switching element of motor drive circuit), Q7, Q8...second power switching element

Claims

1. A composite device having a refrigerant compression function and a heat medium heating function, a compression mechanism that compresses a refrigerant; an electric motor that drives the compression mechanism; a compressor housing that houses the compression mechanism and the electric motor in series therein and has a refrigerant inlet through which the refrigerant compressed by the compression mechanism flows into the compressor housing and a refrigerant outlet through which the refrigerant compressed by the compression mechanism flows out of the compressor housing; an electric heater for heating the heat medium; a heater housing that accommodates the electric heater therein and has a heat medium inlet through which a heat medium to be heated by the electric heater flows into the heater housing and a heat medium outlet through which the heat medium heated by the electric heater flows out of the heater housing; a motor drive circuit for controlling the electric motor; a heater control circuit that controls the electric heater; a circuit housing that accommodates the motor drive circuit and the heater control circuit therein; Including, the compressor housing, the heater housing, and the circuit housing are integrally joined together; the motor drive circuit has a switching element that converts a DC voltage into an AC voltage; In the circuit housing, a switching element of the motor drive circuit is arranged so as to be cooled by the refrigerant flowing into the compressor housing and also by the heat medium flowing into the heater housing. Composite device.

2. the interior of the compressor housing and the interior of the circuit housing are separated by a first partition, and the interior of the heater housing and the interior of the circuit housing are separated by a second partition adjacent to the first partition, the refrigerant inlet of the compressor housing is provided near the first partition portion, the heat medium inlet of the heater housing is provided in the vicinity of the second partition portion, Within the circuit housing, a switching element of the motor drive circuit is disposed so as to be in thermal contact with a portion of the first partition portion on a side closer to the second partition portion. The composite device according to claim 1 .

3. The device is used by being incorporated into a refrigerant circuit in which a refrigerant circulates and a heat medium circuit in which a heat medium circulates using a pump unit. a rotation speed detection unit that detects the rotation speed of the electric motor; a control unit configured to control the overall operation of the composite device and to be able to communicate with a pump control device that controls the pump unit; further comprising The control unit is configured to output a pump operation request to the pump control device when the electric motor is operating at a low rotation speed equal to or lower than a predetermined rotation speed, thereby operating the pump unit to cause the heat medium to flow inside the heater housing. The composite device according to claim 1 or 2.

4. a temperature detection unit that detects the temperature of a switching element of the motor drive circuit; the control unit outputs a pump operation request to the pump control device when the electric motor is operating at a low rotation speed equal to or lower than a predetermined rotation speed and when the temperature of a switching element of the motor drive circuit is equal to or higher than a first threshold temperature. The composite device according to claim 3 .

5. 5. The compound apparatus according to claim 4, wherein the control unit forcibly stops the electric motor when the temperature of a switching element of the motor drive circuit reaches or exceeds a second threshold temperature that is higher than the first threshold temperature.

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