Composite device

Abstract

The purpose of the present invention is to provide a composite device which can contribute to the miniaturization of a vehicle air-conditioning device or the like and which can ensure the cooling (heat dissipation) performance of a switching element that converts a DC voltage to an AC voltage. A composite device (1) having a refrigerant compression function and a heat medium heating function comprises: a first housing (2A) in which a compression mechanism (3) for compressing a refrigerant and an electric motor (4) for driving the compression mechanism (3) are accommodated in series; a second case (2B) in which an electric heater (5) for heating the heat medium is housed; and a third case (2C) in which the motor drive circuit (20) and the heater control circuit (30) are housed. In the third housing (2C), first power switching elements (Q1-Q6) of the motor drive circuit (20) are disposed so as to be capable of being cooled by a refrigerant flowing into the first housing (2A) from the refrigerant inlet (8), and also so as to be capable of being cooled by a heat medium flowing into the second housing (2B) from the heat medium inlet (10).

Description

Technical Field

[0001] The invention relates to a composite device with a refrigerant compression function and a heat medium heating function. Background Art

[0002] Patent document 1 describes a vehicle air conditioning device that can be applied to vehicles such as hybrid vehicles and electric vehicles. The vehicle air conditioning device described in Patent document 1 has a refrigerant circuit including the following structure: an electric compressor that compresses the refrigerant, a radiator that dissipates heat from the refrigerant discharged from the electric compressor and heats the air supplied to the vehicle cabin, an expansion valve that decompresses and expands the refrigerant after heat dissipation, and a heat exchanger equivalent to an evaporator that performs heat exchange between the decompressed and expanded refrigerant and the outside air. In addition, in order to assist the radiator in heating the vehicle cabin, the vehicle air conditioning device described in Patent document 1 has a heat medium heating electric heater that heats the heat medium, and a heat medium-air heat exchanger that heats the air supplied to the vehicle cabin with the heated heat medium. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2014-213765 Summary of the invention Technical problem to be solved by the invention

[0004] The vehicle air conditioning device described in Patent Document 1 can make up for the lack of heating capacity of the radiator. However, in the vehicle air conditioning device described in Patent Document 1, an electric compressor, a heat medium heating electric heater, etc. are provided separately. Therefore, the device is enlarged as a whole, and there is room for improvement in terms of installation space, etc.

[0005] An object of the present invention is to provide a composite device that can contribute to miniaturization of a vehicle air conditioner or the like and can ensure cooling (heat dissipation) performance of a switching element that converts a DC voltage into an AC voltage. Technical solutions to technical problems

[0006] According to one aspect of the present invention, a composite device having a refrigerant compression function and a heat medium heating function is provided. The composite device includes: a compression mechanism for compressing the refrigerant; a motor for driving the compression mechanism; a compressor housing, the compressor housing accommodates the compression mechanism and the motor in series, and has a refrigerant inlet for allowing the refrigerant compressed by the compression mechanism to flow into the interior and a refrigerant outlet for allowing the refrigerant compressed by the compression mechanism to flow out to the outside; an electric heater for heating the heat medium; a heater housing, the heater housing accommodates the electric heater, and has a heat medium inlet for allowing the heat medium heated by the electric heater to flow into the interior and a heat medium outlet for allowing the heat medium heated by the electric heater to flow out to the outside; a motor drive circuit for controlling the motor; a heater control circuit for controlling the electric heater; and a circuit housing, the circuit housing accommodates the motor drive circuit and the heater control circuit, and the compressor housing, the heater housing, and the circuit housing are coupled as one. The motor drive circuit has a switching element that converts a DC voltage into an AC voltage. In the circuit housing, the switching element of the motor drive circuit is configured to be cooled by the refrigerant flowing into the compressor housing and also by the heat medium flowing into the heater housing. Effects of the Invention

[0007] According to the present invention, it is possible to provide a composite device that can contribute to miniaturization of a vehicle air conditioner or the like and can ensure cooling (heat dissipation) performance of a switching element that converts a DC voltage into an AC voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a front view of the composite device according to the embodiment. Figure 2 It is a right side view of the composite device according to the embodiment. Figure 3 It is a top view of the composite device according to the embodiment. Figure 4 is a partial schematic cross-sectional view of the composite device involved in the embodiment, which is equivalent to Figure 2 FIG. 20 is an AA cross-sectional view of the embodiment of the present invention. Figure 5 FIG. 1 is a diagram showing a configuration example of a main part of a motor drive circuit of a composite device according to an embodiment. Figure 6 It is a diagram showing a configuration example of a main part of a heater control circuit of a composite device according to an embodiment. Figure 7 is a partial schematic cross-sectional view of the composite device involved in the embodiment, which is equivalent to Figure 3 FIG. BB cross-sectional view. Figure 8 This is a block diagram showing a schematic configuration of a control system of a multi-purpose device according to an embodiment. Fig. 9 This is a flowchart showing an example of the operation control of the refrigerant compression function. Fig.10 This is a flowchart showing an example of the operation control of the refrigerant compression function. Fig.11 This is a flowchart showing an example of the operation control of the heat medium heating function. DETAILED DESCRIPTION

[0009] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0010] Figure 1 to Figure 4 A schematic configuration of a composite device 1 according to an embodiment of the present invention is shown. Figure 1 is a front view of the composite device 1 according to the embodiment, Figure 2 is a right side view of the composite device 1 according to the embodiment, Figure 3 is a top view of the composite device 1 according to the embodiment, Figure 4 is a partial schematic cross-sectional view of the composite device involved in the embodiment, which is equivalent to Figure 2 FIG. 20 is an AA cross-sectional view of the embodiment of the present invention.

[0011] The combined device 1 according to the embodiment has a refrigerant compression function for compressing the refrigerant and a heat medium heating function for heating a heat medium different from the refrigerant. That is, the combined device 1 has a structure in which a refrigerant compressor and a heat medium heating device are integrated.

[0012] The composite device 1 can be applied to the vehicle air conditioning device as described above. That is, the composite device 1 can be assembled in a refrigerant circuit in which the refrigerant circulates and a heat medium circuit in which the pump unit circulates the heat medium for use. The pump unit can be mainly composed of an electric pump. However, it is not limited to this, and the pump unit only needs to have a structure that allows the heat medium to circulate in the heat medium circuit. For example, the refrigerant compression function unit of the composite device 1 can be configured to be assembled in the refrigerant circuit, compress the refrigerant passing through the expansion valve and the evaporator (or a heat exchanger equivalent to the evaporator), and provide the compressed refrigerant to the radiator (refrigerant-air heat exchanger) that heats the air provided to the vehicle compartment. In addition, the heat medium heating function unit of the composite device 1 can be configured to be assembled in the heat medium circuit, heat the heat medium passing through the heat medium-air heat exchanger that heats the air provided to the vehicle compartment, and provide the heated heat medium to the heat medium-air heat exchanger. In addition, the refrigerant and the heat medium can be selected arbitrarily, for example, a gaseous refrigerant can be used as the refrigerant, and a liquid can be used as the heat medium. In addition, although not particularly limited, water (including water mixed with antifreeze etc.) is generally used as the heat medium. Therefore, the heat medium heating function may also be referred to as the water heating function.

[0013] Reference Figure 1 to Figure 4 The composite device 1 has a housing 2. The housing 2 of the composite 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 coupled (fastened) by fastening members such as bolts (not shown).

[0014] The first housing 2A is formed in a substantially cylindrical shape. A compression mechanism 3 for compressing the refrigerant and a motor 4 for driving the compression mechanism 3 are accommodated in series in the axial direction inside the first housing 2A. Although not particularly limited, the compression mechanism 3 may be a scroll compression mechanism including a fixed scroll and a movable (rotating) scroll. In addition, the output shaft 4a of the motor 4 is connected to the compression mechanism 3 (for example, the movable (rotating) scroll).

[0015] One of the two opening ends of the first housing 2A ( Figure 1 , Figure 2 The lower opening end in the middle (i.e., the opening end on the compression mechanism 3 side of the first housing 2A) is closed by the first cover portion 2D. In addition, the first housing 2A that accommodates the compression mechanism 3 and the motor 4 that drives the compression mechanism 3 can also be called a "compressor housing".

[0016] The second housing 2B is disposed on 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 opening ends of the second housing 2B ( Figure 1 , Figure 2 The lower open end of the housing 2B is closed by the second cover 2E. In addition, the second housing 2B that accommodates the electric heater 5 may also be referred to as a "heater housing".

[0018] The third housing 2C is formed into a box shape with an open top surface. The third housing 2C contains a motor drive circuit 20 for controlling the motor 4 and a heater control circuit 30 for controlling the electric heater 5. Specifically, a circuit board 6 on which the motor drive circuit 20 and the heater control circuit 30 are mounted is contained 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 ( Figure 1 , Figure 2 The upper opening end in the middle) that is, the opening end of the motor 4 side of the first housing 2A and the other opening end of the second housing 2B ( Figure 1 , Figure 2 The upper opening end of the first shell 2A is formed in the bottom wall 7 of the third shell 2C. Thus, the interior of the first shell 2A and the interior of the third shell 2C are separated, and the interior of the second shell 2B and the interior of the third shell 2C are separated. That is, the bottom wall 7 of the third shell 2C has a first separation portion 71 that separates the interior of the first shell 2A and the interior of the third shell 2C, and a second separation portion 72 that separates the interior of the second shell 2B and the interior of the third shell 2C. In addition, the first separation portion 71 and the second separation portion 72 are adjacent to each other.

[0020] The upper surface (opening end) of the third housing 2C is closed by the third cover portion 2F. The third housing 2C that houses the motor drive circuit 20 and the heater control circuit 30 may also be referred to as a "circuit housing".

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

[0022] A refrigerant inlet 8 is formed on the first shell 2A for allowing the refrigerant circulating in the refrigerant circuit to flow into the interior. The refrigerant to flow in is, for example, a refrigerant that has passed through an expansion valve and an evaporator (or a heat exchanger equivalent thereto), that is, a low-temperature and low-pressure refrigerant. In the present embodiment, the refrigerant inlet 8 is provided at a portion on the third shell 2C side of the first shell 2A, that is, in the vicinity of a first partition 71 that separates the interior of the first shell 2A from the interior of the third shell 2C. Preferably, the refrigerant inlet 8 is configured to allow the refrigerant circulating in the refrigerant circuit to flow into the first shell 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 interior of the first shell 2A through the refrigerant inlet 8 flows in the interior of the first shell 2A and is sucked into the compression mechanism 3. The refrigerant sucked into the compression mechanism 3 is compressed by the compression mechanism 3, becomes a high-temperature, high-pressure refrigerant, and is discharged from the compression mechanism 3. The discharged (high-temperature, high-pressure) refrigerant flows out from the refrigerant outlet 9 formed in the first shell 2A, and is provided to the above-mentioned radiator (refrigerant-air heat exchanger), for example.

[0024] In this embodiment, the refrigerant outlet 9 is provided at a position on the first cover portion 2D side of the first shell 2A, that is, at Figure 1 , Figure 2 Therefore, in the present embodiment, the refrigerant flowing into the first shell 2A from the refrigerant inlet 8 flows in the first shell 2A from the refrigerant inlet 8. Figure 1 , Figure 2 The upper side of the flow is directed toward the lower side.

[0025] In addition, the first partition 71 can be cooled by the (low-temperature and low-pressure) refrigerant flowing into the first housing 2A through the refrigerant inlet 8, and the motor 4 can be cooled by the refrigerant flowing inside the first housing 2A. In addition, 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 provided with a heat medium inlet 10 for allowing the heat medium circulating in the heat medium circuit to flow into the interior. The heat medium flowing in is, for example, the heat medium passing through the heat medium-air heat exchanger, that is, a low-temperature heat medium. In the present embodiment, the heat medium inlet 10 is provided at a portion of the second housing 2B on the third housing 2C side, that is, near the second partition 72 that partitions the interior of the second housing 2B from the interior of the third housing 2C and at Figure 1 The inner side of Figure 2 Preferably, the heat medium inlet 10 is configured to allow the refrigerant circulating in the heat medium circuit to flow into the second shell 2B so that at least a portion of the heat medium flows along the second partition portion 72 .

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

[0028] In the present embodiment, the heat medium outlet 11 is provided near the second partition 72 that partitions the interior of the second housing 2B and the interior of the third housing 2C. Figure 1 The front side of Figure 2 Therefore, in this embodiment, the heat medium that flows into the second housing 2B from the heat medium inlet 10 is moved along the second partition 72 in the second housing 2B. Figure 2 , Figure 4 The right side flows towards the left side.

[0029] The second partition 72 can be cooled by the (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 constitute a 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 motor 4 and the power supply line from the heater control circuit 30 to the electric heater 5 extend through the bottom wall 7 of the third housing 2C in an airtight and liquidtight state.

[0031] Next, refer to Figure 5 and Figure 6 , the motor drive circuit 20 that controls (drives) the motor 4 and the heater control circuit 30 that controls the electric heater 5 will be described.

[0032] Figure 5 2 is a diagram showing an example of the main structure of the motor drive circuit 20. In the present embodiment, the motor drive circuit 20 is configured to convert a DC voltage from an external power supply into a three-phase AC voltage and supply the voltage to the motor 4, thereby controlling (driving) the motor 4. The motor drive circuit 20 includes a smoothing unit 21, a first power module 22, and a first drive circuit 23.

[0033] The smoothing unit 21 is connected between a power line and a ground line of an external power source, and smoothes a DC voltage from the external power source. 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 switch elements (hereinafter referred to as "first power switch elements") Q1 to Q6 and six diodes D1 to D6. Although not particularly limited, the first power switch elements Q1 to Q6 may be IGBTs (insulated gate bipolar transistors). The first power module 22 controls the first power switch elements Q1 to Q6 through PMW, converts the DC voltage from the external power supply smoothed by the smoothing unit 21 into a three-phase AC voltage, and provides it to the motor 4.

[0035] Specifically, the first power module 22 includes a U-phase arm, a V-phase arm, and a W-phase arm which are provided in parallel with each other between a power line of the external power source and a 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 anti-parallel 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 anti-parallel to 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 anti-parallel to the first power switching elements Q5 and Q6, respectively.

[0039] In addition, the midpoints of the U, V, and W phase arms are connected to the other ends of the U, V, and W phase coils of the motor 4 that are star-connected at their respective ends. That is, the midpoint of the power switching elements Q1 and Q2 of the U phase arm is connected to the U phase coil, the midpoint of the power switching elements Q3 and Q4 of the V phase arm is connected to the V phase coil, and the midpoint of the power switching elements Q5 and Q6 of the W phase arm is connected to the W phase coil.

[0040] Therefore, the first power module 22 controls the ratio between the conduction period of the first power switch elements Q1, Q3, Q5 on the power line side of each phase arm and the conduction period of the first power switch elements Q2, Q4, Q6 on the ground line side (PWM control), thereby being able to convert the DC voltage from the external power supply smoothed by the smoothing unit 21 into a three-phase AC voltage and provide it to the motor 4, thereby being able to drive the motor 4 and the compression mechanism 3.

[0041] The first drive circuit 23 performs on / off driving (PWM control) of the first power switching elements Q1 to Q6 based on a control signal (PWM signal) from a control unit 15 of the composite device 1 described later.

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

[0043] Figure 6 3 is a diagram showing a configuration example of a main part of the motor drive circuit 30. In the present embodiment, the heater control circuit 30 is configured to apply a voltage of a high-voltage power supply to the electric heater 5, and includes a second power module 31 and a second drive circuit 32.

[0044] The second power module 31 includes two power switch elements (hereinafter referred to as "second power switch elements") Q7 and Q8 for controlling the power supply to the electric heater 5. The second power switch elements Q7 and Q8 may be IGBTs, similar to the first power switch elements Q1 to Q6 of the motor drive circuit 20. In the present embodiment, the second power switch element Q7 of the two second power switch elements Q7 and Q8 is arranged on the output side (voltage side) of the high voltage power supply closer to the electric heater 5, and the other second power switch element Q8 is arranged on the ground side closer to the high voltage power supply than 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 controlling the temperature of the heat medium heated by the electric heater 5 .

[0046] The second drive circuit 32 performs on / off driving (PWM control) of the second power switching elements Q7 and Q8 based on a control signal (PWM signal) from a control unit 15 of the composite device 1 described later.

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

[0048] Here, refer to Figure 7 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 composite device 1 according to the embodiment will be described. Figure 7 is a partial schematic cross-sectional view of the composite device 1 (equivalent to Figure 3 BB cross-sectional view of FIG).

[0049] As described above, the motor drive circuit 20 and the heater control circuit 30 are mounted on the circuit substrate 6 and housed inside the third housing 2C. Figure 7 As shown, the circuit substrate 6 is mounted on a plurality of substrate mounting portions 12 provided inside the third housing 2C, for example. In the present embodiment, the plurality of substrate mounting portions 12 are respectively formed in a sleeve shape 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 substrate 6 is mounted on the upper surface of the plurality of substrate mounting portions 12 by screws 13.

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

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

[0052] In addition, the second power switching elements Q7 and Q8 of the motor drive circuit 30 are mounted on the surface of the circuit substrate 6 mounted on the substrate mounting portion 12 on the side of the bottom wall 7 of the third shell 2C, and are respectively in thermal contact with a portion of the second partition portion 72 on the side of the first partition portion 71, and preferably in thermal contact with a portion of the second partition portion 72 adjacent to the first partition portion 71 (separated by a boundary).

[0053] In addition, “thermal contact with X” means a state in which heat exchange with X is possible, including a case of direct contact with X, a case of proximity to X, and a case of indirect contact with X via a heat exchange component with high thermal conductivity.

[0054] Figure 8 1 is a block diagram showing a schematic structure of a control system of the composite device 1 according to the embodiment. The composite device 1 includes a control unit 15 for controlling the overall operation of the composite device 1. In the present embodiment, an operation / stop command of a refrigerant compression function, an operation / stop command of a heat medium heating function, etc. are input to the control unit 15 from a higher-level control device (for example, a control device of the above-mentioned vehicle air conditioning device).

[0055] In addition, detection signals of various detection units are input to the control unit 15, such as a rotation speed detection unit 51 for detecting the rotation speed of the motor 4, a first temperature detection unit 52 for detecting the temperature of the first power switch elements Q1 to Q6, and a second temperature detection unit 53 for detecting the temperature of the second power switch elements Q7 and Q8. In addition, the rotation speed detection unit 51 can also calculate the rotation speed of the motor 4. The first temperature detection unit 52 can detect a value related to the temperature of the first power switch elements Q1 to Q6, and the second temperature detection unit 53 can detect a value related to the temperature of the second power switch elements Q7 and Q8.

[0056] In addition, in the present embodiment, the control unit 15 can be configured to be communicatively connected to a pump control device 60, which controls the pump unit that causes the heat medium to circulate in the heat medium circuit, and by outputting an action request of the pump unit (hereinafter referred to as "pump action request") to the pump control device 60, the pump unit is operated via the pump control device 60, that is, the heat medium is circulated in the heat medium circuit.

[0057] In addition, the control unit 15 controls the operation of the refrigerant compression function and the heat medium heating function of the composite device 1 based on the command from the upper control device and the detection results of the various detection units. The operation control of the refrigerant compression function and the operation control of the heat medium heating function by the control unit 15 will be described below.

[0058] Fig. 9 , Fig.10 1 is a flowchart showing an example of the operation control of the refrigerant compression function performed by the control unit 15 .

[0059] In step S1, the control unit 15 determines whether an operating command for the refrigerant compression function is input. If an operating command for the refrigerant compression function is input (step S1: Yes), the control unit 15 proceeds to the process of step S2.

[0060] In step S2, the control unit 15 activates the refrigerant compression function. That is, the control unit 15 outputs a control signal (PWM signal) corresponding to the operation instruction of the refrigerant compression function to the first drive circuit 23, and drives the first power switch elements Q1 to Q6 to be turned on / off, thereby activating the motor 4 and activating the refrigerant compression function.

[0061] In step S3, the control unit 15 determines whether the rotation speed of the 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 step S4.

[0062] In step S4, the control unit 15 determines whether a stop command of the refrigerant compression function is input. If a stop command of the refrigerant compression function is input (step S4: Yes), the control unit 15 proceeds to the process of step S5, and if a stop command of the refrigerant compression function is not 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 motor 4 and stops the operation of the refrigerant compression function by stopping the output of the control signal (PWM signal) of the first drive circuit 23. Then, when the operation of the refrigerant compression function is stopped, the control unit 15 ends this process.

[0064] In the process of step S3 , when the motor speed is lower than the predetermined speed (step S: Yes), that is, when the motor 4 is operating at a low speed lower than the predetermined speed, the control unit 15 proceeds to the process of step S6 .

[0065] In step S6 , the control unit 15 detects the temperature of the first power switching elements Q1 to Q6 (hereinafter referred to as “first switching element temperature”). 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 above the 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 above 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 (> the 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 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 unit is operated, and the heat medium circulates in the heat medium circuit (that is, the heat medium flows inside the second housing 2B).

[0069] In step S10, the control unit 15 determines whether a stop command of the refrigerant compression function is input. When a stop command of the refrigerant compression function is input (step S10: Yes), the control unit 15 proceeds to step S11, outputs the cancellation of the pump operation request to the pump control device 60, and then proceeds to the process of step S5. That is, the control unit 15 stops the operation of the refrigerant compression function. On the other hand, when a stop command of the refrigerant compression function is not input (step S11: No), the control unit 15 returns to the process of step S6.

[0070] In the process of step S8, when the temperature of the first switching element is above the second threshold temperature (step S8: yes), the control unit 15 enters the process of step S12 to forcibly stop the action of the refrigerant compression function. That is, the control unit 15 immediately stops the output of the control signal (PWM signal) to the first drive circuit 23. This is to achieve overheat protection of the first power switching elements Q1 to Q6. Then, when the action of the refrigerant compression function is forcibly stopped, the control unit 15 ends this process. In addition, when the pump action request has been output to the pump control device 60, the control unit 15 outputs the cancellation of the pump action request to the pump control device 60.

[0071] Fig.11 This is a flowchart showing an example of the operation control of the heat medium heating function performed by the control unit 15 .

[0072] In step S21, the control unit 15 determines whether an operation command of the heat medium heating function is input. Then, when an operation command of the heat medium heating function is input (step S21: Yes), the control unit 15 proceeds to the process 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 the operation instruction of the heat medium heating function to the second drive circuit 32, and drives the second power switch elements Q7 and Q8 to be turned on / off, thereby activating the motor 5 and activating the heat medium heating function.

[0074] In step S23 , the control unit 15 detects the temperature of the second power switching elements Q7 and Q8 (hereinafter referred to as “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 step S25.

[0076] In step S25, the control unit 15 determines whether a stop command of the heat medium heating function is input. When a stop command of the heat medium heating function is not input (step S25: No), the control unit 15 returns to the process of step S23. On the other hand, when a stop command of the heat medium heating function is input (step S25: Yes), the control unit 15 proceeds to the process 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 drive 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 process.

[0078] In the process of step S24, when the temperature of the third switching element is higher than the third threshold temperature (step S24: yes), the control unit 15 enters the process of step S27 to forcibly stop the operation of the heat medium heating function. That is, the control unit 15 immediately stops the output of the control signal (PWM signal) to the second drive circuit 32. This is to achieve overheat protection of the second power switch elements Q7 and Q8. Then, when the operation of the heat medium heating function is forcibly stopped, the control unit 15 ends this process.

[0079] According to the composite device 1 according to the embodiment, the following effects can be obtained.

[0080] The composite device 1 includes a first housing (compressor housing) 2A in which a compression mechanism 3 for compressing a refrigerant and a motor 4 for driving the compression mechanism 3 are serially housed, a second housing (heater housing) 2B in which an electric heater 5 for heating a heat medium is housed, and a third housing (circuit housing) 2C in which a motor drive circuit 20 for controlling the motor 4 and a heater control circuit 30 for controlling the electric heater 5 are housed. The first housing 2A has a refrigerant inlet 8 for allowing the refrigerant compressed by the compression mechanism 3 to flow into the interior, and a refrigerant outlet 9 for allowing the refrigerant compressed by the compression mechanism 3 to flow out to the outside, and the second housing 2B has a heat medium inlet 10 for allowing the heat medium heated by the electric heater 5 to flow into the interior, and a heat medium outlet 11 for allowing the heat medium heated by the electric heater 5 to flow out to the outside. Moreover, the first housing 2A, the second housing 2B, and the third housing 2C are coupled to form a whole.

[0081] Such a composite device 1 can function as a refrigerant compressor (electric compressor) for compressing the refrigerant and a heat medium heating device for heating the heat medium, and can heat the heat medium while compressing the refrigerant. Therefore, the composite device 1 can be applied to the vehicle air conditioning device as described above. Moreover, by applying the composite device 1 to the vehicle air conditioning device, the vehicle air conditioning device can be miniaturized compared to the existing structure that has an electric compressor and a heat medium heating device separately.

[0082] In addition, in the third housing 2C, the first power switch elements Q1 to Q6 of the motor drive circuit 20 are configured to be cooled by the refrigerant flowing into the first housing 2A and the heat medium flowing into the second housing 2B. Specifically, the first power switch elements Q1 to Q6 are configured to be in thermal contact with a portion of a first partition 71 that partitions the interior of the first housing 2A and the interior of the third housing 2C on the side of a second partition 72 that partitions the interior of the second housing 2B and the interior of the third housing 2C, the refrigerant inlet 8 of the first housing 2A is provided near the first partition 71, and the heat medium inlet 10 of the second housing 2B is provided near the second partition 72.

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

[0084] In addition, the control unit 15 is configured to output the pump operation request to the pump control device 60 that controls the pump unit that circulates the heat medium in the heat medium circuit when the motor 4 (i.e., the refrigerant compression function) operates at a low speed below a specified speed, thereby operating the pump unit to cause the heat medium to flow inside the second shell 2B.

[0085] When the motor 4 is operated at a low speed, the refrigerant flowing into the first housing 2A decreases, and the cooling performance of the refrigerant on the first partition 71 and the cooling performance of the first power switch elements Q1 to Q6 is reduced. In the present embodiment, when the motor 4 is operated at a low speed, the pump operation request is output to the pump control device 60, so that the heat medium flows in the second housing 2B. Therefore, the portion of the first partition 71 on the second partition 72 side is cooled by the heat medium, and as a result, the first power switch elements Q1 to Q6 can be cooled by the heat medium. That is, the reduction in the cooling performance of the refrigerant on the first power switch elements Q1 to Q6 can be compensated by cooling with the heat medium. Therefore, even when the motor 4 is operated at a low speed, the cooling (heat dissipation) performance of the first power switch elements Q1 to Q6 can be ensured.

[0086] In addition, the control unit 15 is configured to output the pump operation request to the pump control device 60 when the temperature of the first power switching elements Q1 to Q6 is higher than the first threshold temperature. Therefore, the reduction in the cooling performance of the first power switching elements Q1 to Q6 by the refrigerant can be effectively and efficiently compensated by utilizing the cooling of the heat medium.

[0087] Furthermore, the control unit 15 is configured to forcibly stop the refrigerant compression function (motor 4) when the temperature of the first power switching elements Q1 to Q6 is higher than the second threshold temperature (> the first threshold temperature). Therefore, the first power switching elements Q1 to Q6 can be protected from overheating.

[0088] In addition, in the above-mentioned embodiment, the control unit 15 outputs the pump action request to the pump control device 60. However, this is not limited to this. The control unit 15 may also be configured to output the pump action request to a control device other than the pump control device 60 (for example, the upper control device), and provide the pump control device 60 with an action instruction of the pump unit from the control device. That is, the pump control device 60 only needs to operate the pump unit based on the pump action request output from the control unit 15, and "outputting the pump action request to the pump control device 60" includes the case where the pump action request is indirectly output to the pump control device 60 via other control devices.

[0089] In addition, the control unit 15 may also change the pump action requirement (content) according to the temperature of the first power switch elements Q1 to Q6. For example, the pump action requirement may also include flow rate information of the heat medium circulating in the heat medium circuit, and the control unit 15 outputs the pump action requirement to the pump control device 60, so that the higher the temperature of the first power switch elements Q1 to Q6, the greater the flow rate of the heat medium circulating in the heat medium circuit (i.e., the flow rate of the heat medium flowing inside the second housing 2B).

[0090] In addition, in the above embodiment, the motor drive circuit 20 and the heater control circuit 30 are mounted on one circuit substrate 6. However, this is not limiting. The motor drive circuit 20 and the heater control circuit 30 may be mounted on separate circuit substrates, or the motor drive circuit 20 and / or the heater control circuit 30 may be split and mounted on a plurality of circuit substrates.

[0091] In the above description, the case where the composite device 1 is applied to a vehicle air conditioner is mainly described. However, the composite device 1 is not limited thereto. The composite device 1 can be applied to various devices or systems using an electric compressor for compressing a refrigerant and a heat medium heating device for heating a heat medium.

[0092] As mentioned above, although the embodiment of the present invention has been described, the present invention is not limited to the above-mentioned embodiment, and it is needless to say that deformation and modification can be made based on the technical idea of ​​the present invention. Description of symbols

[0093] 1…combined device, 2…housing, 2A…first housing (compressor housing), 2B…second housing (heater housing), 2C…third housing (circuit housing), 3…compression mechanism, 4…motor, 5…electric heater, 6…circuit substrate, 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 unit, 71…first partition, 72…second partition, Q1 to Q6…first power switch element (switching element of the motor drive circuit), Q7, Q8…second power switch element.

Claims

1. A composite device having a refrigerant compression function and a heat medium heating function, characterized in that: Include: A compression mechanism for compressing the refrigerant; an electric motor for driving the compression mechanism; a compressor housing that accommodates the compression mechanism and the electric motor in series therein and has a refrigerant inlet for allowing the refrigerant compressed by the compression mechanism to flow into the interior and a refrigerant outlet for allowing the refrigerant compressed by the compression mechanism to flow out to the outside; An electric heater for heating a heat medium; a heater housing that accommodates the electric heater and has a heat medium inlet for allowing the heat medium heated by the electric heater to flow into the interior and a heat medium outlet for allowing the heat medium heated by the electric heater to flow out to the outside; a motor drive circuit for controlling the motor; a heater control circuit for controlling the electric heater; as well as a circuit housing that accommodates the motor drive circuit and the heater control circuit therein; The compressor housing, the heater housing and the circuit housing are coupled as one body. The motor drive circuit has a switching element for converting a DC voltage into an AC voltage. In the circuit housing, the 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.

2. The composite device according to claim 1, characterized in that 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 disposed near the first partition portion. The heat medium inlet of the heater housing is provided near the second partition portion. In the circuit case, the switching element of the motor drive circuit is arranged so as to be in thermal contact with a portion of the first partition portion on a side close to the second partition portion.

3. The composite device according to claim 1 or 2, characterized in that: It is used in a refrigerant circuit that circulates the refrigerant and a heat medium circuit that circulates the heat medium through a pump unit. The composite device further comprises: a rotation speed detection unit configured to detect the rotation speed of the motor; and a control unit that controls the overall operation of the composite device and is configured to be able to communicate with a pump control device that controls the pump unit, The control unit is configured to output a pump operation request to the pump control device when the electric motor is operated 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 into the heater case.

4. The composite device according to claim 3, characterized in that further comprising a temperature detection unit for detecting the temperature of the switching element of the motor drive circuit, The control unit outputs a pump operation request to the pump control device when the temperature of the switching element of the motor drive circuit is equal to or higher than a first threshold temperature when the electric motor is operated at a low rotation speed equal to or lower than a predetermined rotation speed.

5. The composite device according to claim 4, characterized in that The control unit forcibly stops the motor when the temperature of the 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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