JP2009274725A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner capable of protecting a motor driving circuit of an electric compressor even when the electric compressor is stopping. <P>SOLUTION: The air conditioner has a refrigerating cycle 100 comprising the electric compressor 110 in which a compressing mechanism 111 for sucking and compressing refrigerant and an electric motor 112 for driving the compressing mechanism 111 are integrally formed and a motor driving circuit 113 is cooled by the sucked refrigerant sucked by the compressing mechanism 111, and a control device 200 for controlling operation of the motor driving circuit 113 and the refrigerating cycle 100. In the air conditioner, even when the compressing mechanism 111 is in a stop state, the control device 200 operates the motor 112 by the motor driving circuit 113 to make the compressing mechanism 111 in an operation state when temperature Ti of the motor driving circuit 113 exceeds predetermined temperature, and varies a condition of supplying air to be heat-exchanged with the refrigerant circulating in the refrigerating cycle 100 so as to decrease temperature of the sucked refrigerant. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an air conditioner in which an electric compressor driven by a motor is used as a compressor for compressing a refrigerant in a refrigeration cycle, and a circuit for driving the motor is protected by the refrigerant. It is suitable for use in an air conditioner.

  As a conventional refrigeration cycle of an air conditioner, as shown in Patent Document 1, for example, an electric compressor is used as a compressor for compressing a refrigerant. This electric compressor is provided with a compression unit, a motor for driving the compression unit, and a motor drive circuit for driving the motor in the housing body, and circuit components (heat generating components) in the motor drive circuit. Is arranged at a position where heat can be exchanged with the suction refrigerant of the compression section.

  When the temperature of the circuit component becomes equal to or higher than the predetermined temperature during the operation of the electric compressor, the flow rate of the suction refrigerant is increased by increasing the rotation speed of the motor to the predetermined rotation speed, and the circuit component is cooled by this refrigerant. The cooling operation can be continued without stopping the motor.

JP 2003-139069 A

  However, when the compression unit is in a stopped state, the temperature of the circuit components may increase due to, for example, radiant heat from the engine in the engine room.

  This invention is made in view of the said point, Comprising: It is providing the air conditioner which enables protection of the motor drive circuit of an electric compressor even when an electric compressor stops.

  In order to achieve the above object, the present invention employs the following technical means.

In the first aspect of the present invention, the compression mechanism (111) for sucking and compressing the refrigerant and the electric motor (112) for driving the compression mechanism (111) are integrally formed, and the compression mechanism (111) is A refrigeration cycle (100) comprising an electric compressor (110) in which a motor drive circuit (113) for driving a motor (112) is cooled by a suction refrigerant sucked;
In an air conditioner having a motor drive circuit (113) and a control device (200) for controlling the operation of the refrigeration cycle (100),
When the temperature (Ti) of the motor drive circuit (113) exceeds a predetermined temperature even when the compression mechanism (111) is stopped, the control device (200) is driven by the motor drive circuit (113). And the compression mechanism (111) is activated, and the supply condition of air exchanged with the refrigerant circulating in the refrigeration cycle (100) is varied to reduce the temperature of the intake refrigerant. .

  Thereby, even when the refrigeration cycle (100) is stopped, when the temperature (Ti) of the motor drive circuit (113) exceeds a predetermined temperature, the refrigerant in the refrigeration cycle (100) is circulated and sucked refrigerant. Thus, the motor drive circuit (113) can be effectively cooled.

  In the second aspect of the present invention, the variable air supply condition is characterized in that the amount of cooling air supplied to the refrigerant condensing condenser (120) provided in the refrigeration cycle (100) is increased. Yes.

  As a result, the pressure and temperature of the high-pressure side refrigerant in the refrigeration cycle (100) are reduced, and accordingly, the pressure and temperature of the low-pressure side refrigerant can be reduced. (113) can be used for cooling.

  In the invention described in claim 2, specifically, as in the invention described in claim 3, the increase in the amount of cooling air is caused by the ability of the cooling fan (121) to supply the cooling air to the condenser (120). Can be handled by raising

  In the fourth aspect of the invention, the change in the air supply condition is to reduce the amount of air-conditioning air supplied to the refrigerant evaporation evaporator (150) provided in the refrigeration cycle (100). It is a feature.

  As a result, the pressure of the low-pressure side refrigerant in the refrigeration cycle (100) can be reduced, and accordingly, the temperature of the low-pressure side refrigerant can be reduced, so that the temperature of the intake refrigerant is reduced to cool the motor drive circuit (113). Can be used for

  In the invention described in claim 4, specifically, as in the invention described in claim 5, the decrease in the amount of air in the air-conditioning air is caused by the blower (151) supplying the air-conditioning air to the evaporator (150). ) Can be reduced.

  According to the sixth aspect of the present invention, the air-conditioning air supplied to the refrigerant evaporation evaporator (150) provided in the refrigeration cycle (100) is selected from indoor air or outdoor air. The air supply condition is variable by supplying air conditioning air to the evaporator (150), and the switching means (320) has a low temperature between indoor air and outdoor air. It is characterized by selecting the air of the direction.

  As a result, the heat absorption of the refrigerant in the evaporator (150) can be reduced and the temperature of the refrigerant can be lowered, so that the temperature of the drawn refrigerant can be lowered and used for cooling the motor drive circuit (113).

  In contrast to the sixth aspect of the present invention, as in the seventh aspect of the present invention, the air supply condition can be changed by supplying air conditioning air to the evaporator (150) and switching means (320). ), Indoor air may be selected from indoor air and outdoor air.

  As a result, the indoor air and the outdoor air are normally kept at a lower temperature by the operation of the refrigeration cycle (100), so that the indoor air as in the invention of claim 6 is maintained. A means for comparing the temperature of the air with the temperature of the outdoor air is not required, and air with a low temperature can be simply supplied to the evaporator (150).

  As in the eighth aspect of the invention, the motor drive circuit (113) is suitable for use integrally with the electric compressor (110), and is a compact motor drive circuit integrated type. An electric compressor (110) can be used.

  Furthermore, if the refrigeration cycle (100) and the control device (200) are applied to those used for a vehicle as in the invention described in claim 9, the external temperature mounted in an engine room, for example, Even when the environment is severe, the motor drive circuit (113) can be effectively protected.

  In addition, the code | symbol in the parenthesis attached | subjected to each said means shows the correspondence with the specific means of embodiment description later mentioned.

1 is a schematic diagram illustrating an overall configuration of a vehicle air conditioner in which an electric compressor integrated with a motor drive circuit is disposed in a refrigeration cycle. It is a characteristic view for a control device to judge the temperature area of a motor drive circuit. It is a control flowchart which a control device performs in order to protect an inverter circuit at the time of an electric compressor operation. It is a control flowchart which a control apparatus performs in order to protect an inverter circuit at the time of an electric compressor stop.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram showing an overall configuration of a vehicle air conditioner 10 in which an electric compressor 110 integrated with a motor drive circuit is disposed in a refrigeration cycle 100. 2 is a characteristic diagram for the control device 200 to determine the temperature range of the motor drive circuit 113, and FIGS. 3 and 4 are controls performed by the control device 200 to protect the motor drive circuit 113 of the electric compressor 110. FIG. It is a flowchart.

  As shown in FIG. 1, a vehicle air conditioner (hereinafter referred to as an air conditioner) 10 according to the present invention is mounted on a hybrid vehicle (applicable to other fuel cell vehicles, electric vehicles, etc.). An indoor unit 300 in which the evaporator 150 in the refrigeration cycle 100 is disposed in the air conditioning case 310, and a control device 200 that controls the operation of the refrigeration cycle 100 and various devices (described in detail later) in the indoor unit 300; Consists of.

  The refrigeration cycle 100 is a well-known cycle in which an electric compressor 110, a condenser 120, a receiver 130, an expansion valve 140, and an evaporator 150 are sequentially connected to form a closed circuit.

  The condenser 120 is a heat exchanger that cools and condenses the refrigerant discharged from the electric compressor 110 (described later in detail). The condenser 120 is provided with a cooling fan 121 that forcibly supplies cooling air in order to effectively cool the refrigerant flowing inside. The operation of the cooling fan 121 is controlled by a control device 200 described later.

  The receiver (gas-liquid separator) 130 is a container that separates the refrigerant flowing out of the condenser 120 into a gas-phase refrigerant and a liquid-phase refrigerant and flows out the liquid-phase refrigerant, and stores excess refrigerant in the refrigeration cycle 100. .

  The expansion valve 140 is a decompression means that decompresses the liquid-phase refrigerant that has flowed out of the receiver 130, and the evaporator 150 is a heat exchanger that evaporates the refrigerant decompressed by the expansion valve 140 and cools the air-conditioning air. is there. Here, the expansion valve 140 is a temperature-type expansion valve that adjusts the valve opening so that the degree of refrigerant superheating on the outlet side of the evaporator 150 becomes a predetermined value.

  The electric compressor 110 is disposed between the condenser 120 provided with the cooling fan 121 and the engine (not shown) in the engine room of the vehicle, and is fixed to the engine, such as an exhaust manifold of the engine. Receives exhaust heat (radiant heat).

  The electric compressor 110 includes a compression mechanism 111 that sucks and compresses refrigerant (a scroll-type compression mechanism in this example) and an electric motor 112 that drives the compression mechanism 111 (a three-phase brushless DC motor in this example). And an inverter circuit 113 for driving the motor 112, which are integrally formed.

  The compression mechanism 111 and the motor 112 are housed in an aluminum alloy compression mechanism housing 111a and a motor housing 112a, respectively. The housing 111a is arranged such that the compression mechanism 111 and the motor 112 are coaxially arranged in series. , 121a are joined together so that the compression mechanism 111 and the motor 112 are integrally formed.

  The motor housing 112a has a suction port 112b connected to the refrigerant outlet side of the evaporator 150, and the compression mechanism housing 111a has a discharge port 111b connected to the refrigerant inlet side of the condenser 120. Is formed. Therefore, the suction refrigerant sucked from the evaporator 150 side by the operation of the compression mechanism 111 reaches the compression mechanism 111 after flowing through the motor housing 112a, is compressed by the compression mechanism 111, and is discharged to the condenser 120 side. Is done.

  The inverter circuit (corresponding to the motor drive circuit in the present invention) 113 is disposed in the casing 113a, and the casing 113a is fixed to the side wall 122c (upper side in FIG. 1) of the motor housing 112a. Thus, the inverter circuit 113 is formed integrally with the motor 112.

  The inverter circuit 113 has a switching element that is ON / OFF controlled by a control device 200 (to be described later) via a control circuit (not shown). By switching, the motor 112 is operated and the rotation speed is varied.

  In addition, some circuit components (for example, photocouplers) constituting the control circuit in the inverter circuit 113 cannot secure sufficient heat resistance, and the switching element can be a heat source that generates heat due to power loss. The inverter circuit 113 is disposed so as to be close to the side wall 112c of the motor housing 112a, and is cooled by the refrigerant flowing through the motor housing 112a as described above.

  The inverter circuit 113 (especially the switching element) is provided with a temperature sensor 113b for detecting the temperature Ti of the inverter circuit 113 and a current sensor 113c for detecting a current value flowing through the inverter circuit 113. The sensors 113b and 113c The detection signal from is input to the control device 200 described later.

  The indoor unit 300 is provided with a blower 151, an inside / outside air switching door 320, a heater 330, etc. in addition to the evaporator 150 described above in a resin air conditioning case 310, and an instrument panel in the vehicle interior. It is mounted inside.

  The blower 151 takes air-conditioning air into the air-conditioning case 310 and supplies the air-conditioning air to the evaporator 150 and the heater 330, and is provided on the upstream side of the evaporator 150. The operation of the blower 151 is controlled by a control device 200 described later.

  On the further upstream side of the blower 151, an inside / outside air switching door for selecting and taking in either the cabin air (inside air) or the cabin outside air (outside air) as air conditioning air (corresponding to the switching means in the present invention) 320 is provided. The inside / outside air switching door 320 is controlled by a control device 200 described later in its rotational position (a position where either the inside air side or the outside air side is opened).

  An inside air temperature sensor 320a for detecting the inside air temperature is provided in a region connected to the inside air side of the inside / outside air switching door 320, and an outside air temperature sensor 320b for detecting the outside air temperature in a region connected to the outside air side of the inside / outside air switching door 320. The temperature signals detected by the sensors 320a and 320b are input to the control device 200 described later.

  A heater 330 is provided on the downstream side of the evaporator 150 to heat the air for air conditioning using engine warm water as a heating source. Between the evaporator 150 and the heater 330, an air mix door 340 for adjusting the mixing ratio of the air cooled by the evaporator 150 and the air heated by the heater 330 is provided. The operation of the door 340 is controlled by the control device 200 described later.

  A plurality of air outlets 350 are provided on the downstream side of the heater 330 of the air conditioning case 310, and are connected to a predetermined part in the passenger compartment.

  The control device 200 detects each of the temperature sensor 113b, the current sensor 113c, the inside air temperature sensor 320a, the outside air temperature sensor 320b, an air conditioner request signal (not shown) input by the user, a set temperature signal (not shown), and the like. Based on the signal, the operation of the inverter circuit 113 (that is, the motor 112, the compression mechanism 111), the cooling fan 121, the blower 151, the inside / outside air switching door 320, and the air mix door 340 is controlled.

  In addition, as shown in FIG. 2, the control device 200 stores in advance a characteristic diagram in which the temperature region of the inverter circuit 113 is divided into a plurality of regions (A, B, C, D in order from the lowest temperature region), The operations of the cooling fan 121, the blower 151, and the inside / outside air switching door 320 are controlled in accordance with a temperature range corresponding to the detected temperature (the predetermined temperature in the present invention and corresponding to B, C, and D). (Details will be described later).

  Next, the operation of the air conditioner 10 based on the above configuration will be described. First, as basic control, upon receiving an air conditioner request signal, the control device 200 uses a set temperature signal, temperature signals from the inside air temperature sensor 320a and the outside air temperature sensor 320b, and the like based on a predetermined arithmetic expression. Calculate the required blowing temperature. Then, the rotational speed of the motor 112 is adjusted via the inverter circuit 113 in accordance with the calculated required blowout temperature, and the compression mechanism 111 is operated at the target rotational speed. In addition, the cooling fan 121 and the blower 151 are operated at the target rotational speed, and the rotational positions of the inside / outside air switching door 320 and the air mix door 340 are changed to the target positions.

  The air for air conditioning is taken in from the open side of the inside / outside air switching door 320 by the blower 151, supplied to the evaporator 150, and cooled by the refrigerant flowing through the evaporator 150. The mixing ratio of the cooled air and a part of the air heated by the heater 330 is adjusted by the air mix door 340, and the air-conditioning air that has been adjusted to the set temperature is discharged from the outlet 350. Be blown out.

  Here, the inverter circuit 113 is cooled by the suction refrigerant flowing in the motor housing 112a. However, depending on the operation state of the inverter circuit 113, the state of radiant heat from the engine, and the like, the inverter circuit 113 is not sufficient with the suction refrigerant alone. May not be adequately cooled. In the present invention, control for solving such cooling insufficiency is provided, which will be described below with reference to the flowcharts shown in FIGS.

  First, as shown in FIG. 3, the control device 200 performs each initialization and initial setting (step S100), and reads various input signals as described above (step S110). When it is determined in step S120 that there is a request for operation of the compression mechanism 111 (there is an air conditioner request signal or the operation of the compression mechanism 111 is required based on the required blowing temperature), the temperature Ti of the inverter circuit 113 obtained from the temperature sensor 113b is determined in step S130. It is determined whether it belongs to area A in the characteristic diagram. If it is determined that the temperature Ti of the inverter circuit 113 belongs to the lowest region A, the compression mechanism 111 is operated at the target rotational speed in step S140. This corresponds to the case of the normal control.

  If it is determined NO in step S130, it is determined in step S150 whether the temperature Ti of the inverter circuit 113 belongs to the B region that is one rank higher than the A region. If it is determined that it belongs to the B region, the rotation is performed in step S160. Determine if number drop protection is required. Here, the rotation speed reduction protection is to forcibly stop the compression mechanism 111 in order to protect the inverter circuit 113 if the motor supply current value in the inverter circuit 113 exceeds the allowable current value. (Step S180) If it is determined that this is not necessary, the rotational speed of the motor 112 is varied (increased or decreased) in Step S170, and the temperature of the intake refrigerant is actively decreased to cool the inverter circuit 113. To increase.

  Here, according to the knowledge of the present inventors, the temperature characteristic of the inverter circuit 113 with respect to the number of revolutions of the motor 112 is determined according to the balance between the cooling effect due to the increase in the amount of sucked refrigerant and the heat generation amount of the inverter circuit 113 itself. It becomes the one that takes the minimum value at the rotation speed. That is, when the rotational speed of the motor 112 is relatively low (lower than a predetermined rotational speed), the amount of refrigerant sucked increases and the cooling effect increases as the rotational speed of the motor 112 is increased. The temperature Ti decreases. On the other hand, when the rotational speed of the motor 112 is relatively high (when the rotational speed is higher than the predetermined rotational speed), the amount of heat generated by the motor drive circuit 113 itself increases as the rotational speed of the motor 112 is increased, and cooling by the suction refrigerant is performed. In order to exceed the effect, the temperature Ti of the inverter circuit 113 increases.

  Therefore, in step S170, first, when the rotational speed of the motor 112 is lower than the predetermined rotational speed, the rotational speed is increased via the inverter circuit 113, and conversely, when it is higher, the rotational speed is decreased. Then, the rotational speed of the cooling fan 121 of the condenser 120 is increased (the capacity of the cooling fan 121 is increased) to increase the amount of cooling air. Further, the rotation position of the inside / outside air switching door 320 is changed so that the air having the lower temperature can be taken in from the air temperature obtained by the inside air temperature sensor 320a and the outside air temperature sensor 320b, and the air having the lower temperature is evaporated. Supply to the vessel 150.

  Then, the temperature Ti of the inverter circuit 113 approaches the minimum value side and decreases due to the variable (increase and decrease) of the rotation speed of the motor 112. In addition, the pressure and temperature of the high-pressure side refrigerant in the refrigeration cycle 100 are reduced by the increase in the cooling air volume by the cooling fan 121, and accordingly, the pressure and temperature of the low-pressure side refrigerant are reduced. Further, the low-temperature air supplied to the evaporator 150 suppresses the heat absorption of the refrigerant, and the refrigerant temperature decreases. Thus, the inverter circuit 113 is effectively cooled by the temperature drop of the amount of refrigerant sucked into the motor housing 112a.

  If it is determined NO in step S150, it is further determined in step S190 whether or not the temperature Ti of the inverter circuit 113 belongs to the C region which is one rank higher than the B region. As in step S160, it is determined whether or not rotation speed reduction protection is necessary. If it is determined that there is no need for rotation speed reduction protection, the cooling refrigerant temperature is further increased in step S210 by lowering the temperature of the suction refrigerant with respect to step S170.

  That is, in step S210, in addition to changing the rotational speed of the motor 112 in step S170, increasing the rotational speed of the cooling fan 121 of the condenser 120, and changing the rotational position of the inside / outside air switching door 320, the rotational speed of the blower 151 is decreased. (Lowering the capacity of the blower 151) to reduce the blown air amount (air amount of air for air conditioning).

  Then, the pressure of the low-pressure side refrigerant of the refrigeration cycle 100 is lowered due to the decrease in the amount of air blown by the blower 151, and the temperature of the low-pressure side refrigerant is lowered accordingly, so the temperature of the refrigerant sucked into the motor housing 112a is changed to step S170. The inverter circuit 113 is effectively cooled.

  If it is determined NO in step S190, the temperature Ti of the inverter circuit 113 belongs to the highest D region in the characteristic diagram, and if NO is determined in step S200, it is necessary to protect the engine speed from falling. In step S220, the compression mechanism 111 is forcibly stopped.

  On the other hand, when it determines with there being no driving | operation request | requirement of the compression mechanism 111 by step S120, it progresses to step S230 or less shown in FIG. In step S230 and subsequent steps, even if the compression mechanism 111 is in a stopped state (the refrigeration cycle 100 is in a stopped state), the temperature Ti of the inverter circuit 113 is increased due to, for example, radiant heat from the engine in the engine room, and may be damaged. Therefore, the flow is to prevent the problem.

  That is, in step S230, it is determined whether or not the temperature Ti of the inverter circuit 113 belongs to the A region, and if it is determined that it belongs to the A region, the cooling of the inverter 113 is not particularly required, and the compression mechanism 111 is stopped ( Step S240).

  If NO is determined in step S230, it is determined whether or not the temperature Ti of the inverter circuit 113 belongs to the B region in step S250. If it is determined that the temperature Ti belongs to the B region, the inverter circuit 113 is cooled in step S260. . That is, in step S260, the motor 112 is operated via the inverter circuit 113, the compression mechanism 111 is activated, the cooling fan 121 is activated, the rotation position of the inside / outside air switching door 320 is changed, and the inside air and outside air are changed. Try to take in the cooler air.

  Then, the refrigerant circulates in the refrigeration cycle 100 by the operation of the compression mechanism 111, and the inverter circuit 113 is cooled by the sucked refrigerant. In addition, by operating the cooling fan 121, the pressure and temperature of the high-pressure side refrigerant are lowered, and accordingly, the pressure and temperature of the low-pressure side refrigerant are lowered. Furthermore, the temperature of the low-pressure side refrigerant is lowered by supplying low-temperature air to the evaporator 150, and the inverter 113 is effectively cooled by the intake refrigerant whose temperature is lowered.

  If NO is determined in step S250, it is determined whether or not the temperature Ti of the inverter circuit 113 belongs to the C region in step S270, and if it is determined that it belongs to the C region, whether or not the rotation speed reduction protection is necessary in step S280. Determine whether. If the rotation speed lowering protection is not required, the temperature of the suction refrigerant is further lowered in step S290 with respect to step S260.

  That is, in step S290, the rotational speed of the motor 112 is varied in the same manner as in steps S170 and S210 described above. Then, the rotational speed of the cooling fan 121 is increased to increase the amount of cooling air, and the rotation position of the inside / outside air switching door 320 opens the side that takes in the lower temperature air between the inside air and the outside air. Further, the rotational speed of the blower 151 is lowered to reduce the amount of blown air supplied to the evaporator 150.

  Then, the temperature Ti of the inverter circuit 113 approaches the minimum value side and decreases due to the variable rotation speed of the motor 112. Then, the temperature of the low-pressure side refrigerant is reduced by increasing the cooling air volume of the cooling fan 121, and the low-temperature side refrigerant is supplied to the evaporator 150 so that the temperature of the low-pressure side refrigerant is lowered. Further, since the temperature of the low-pressure side refrigerant is lowered due to the reduction in the amount of air blown by the blower 151, the temperature of the refrigerant sucked into the motor housing 112a is further lowered with respect to step S260, and the inverter circuit 113 is effectively cooled. The

  If it is determined in step S270 that no (temperature Ti of the inverter circuit 113 is in the D region) and it is determined in step S280 that it is not possible (reduction of rotation speed is necessary), the compression mechanism 111 is stopped in step S300.

  In step S220 and step S300, the compression mechanism 111 is stopped in the control flow, but actually, it is used for the determination in step S190 and step S270 in accordance with the upper limit temperature at which the inverter circuit 113 can rise. By setting the C region, the compression mechanism 111 is prevented from being stopped, and the stop of the compression mechanism 111 is a safety control in the event of an emergency.

  As a result, the temperature Ti of the inverter circuit 113 can be reduced by varying (increasing or decreasing) the rotational speed of the motor 112 in accordance with the rotational speed of the motor 112. In addition, the supply conditions of the air that exchanges heat with the refrigerant circulating in the refrigeration cycle 100 can be varied (increase in the cooling air volume of the cooling fan 121, decrease in the air volume of the blower 151, and intake of low-temperature air into the evaporator 150) ), The temperature of the low-pressure side refrigerant can be effectively lowered, and the inverter circuit 113 can be effectively cooled by the refrigerant having the lowered temperature. Therefore, the motor drive circuit 113 is not stopped without stopping the motor 112. Can be protected.

  Further, even when the compression mechanism 111 is stopped (when the refrigeration cycle 100 is stopped), the motor 112 is operated in accordance with the temperature Ti of the inverter circuit 113 so that the refrigerant in the refrigeration cycle 100 is circulated. As a result, the inverter circuit 113 can be effectively protected.

(Second Embodiment)
In the first embodiment, in determining the rotation position of the inside / outside air switching door 320, the temperature of the inside air and the outside air are compared and the air for the air conditioning having the lower temperature is taken in, but this is not limitative. As a simple method, the inside air temperature sensor 320a and the outside air temperature sensor 320b may be eliminated, and the rotation position of the inside / outside air switching door 320 may be controlled so that the inside air is simply taken.

  This is because the inverter circuit 113 is particularly required to be cooled when the outside air temperature is high and the required cooling capacity of the air conditioner 10 is large. In such a case, the inside air and the outside air are operated by the operation of the refrigeration cycle 100. This is because the inside air is usually kept at a lower temperature.

(Other embodiments)
In the above embodiment, as a method of reducing the temperature of the low-pressure side refrigerant of the refrigeration cycle 100, the cooling air volume of the cooling fan 121 is increased, the air volume of the blower 151 is decreased, and the low temperature side air is taken into the evaporator 150. Although three are used in combination (in combination) (steps S170, S210, S260, S290), the present invention is not limited to this, and depending on the temperature rise state of the inverter circuit 113, each may be handled independently. good.

  For example, only an increase in the cooling air volume of the cooling fan 121 is woven in step S170, and only a decrease in the air volume of the blower 151 is woven in step S210.

  Further, the variable amount of cooling air to the condenser 120 and the amount of air blown to the evaporator 150 do not correspond to the ability of each cooling fan 121 and fan 151 (variable rotation speed). You may make it respond | correspond by the door (a rotation door, a slide door, etc.), a shutter (a rotation shutter, a curtain type shutter, etc.) etc. which were provided in the air circulation part.

  Further, although the inverter circuit 113 has been described as being integrally formed with the motor 112, the inverter circuit 113 may be separately provided with respect to the compression mechanism 111 or the motor 112.

  The air conditioner 10 may be applied not only to a vehicle but also to a domestic air conditioner or a refrigerator such as a refrigerator.

  Further, although the compression mechanism 111 has been described as a scroll-type compression mechanism, it may be another type of compression mechanism such as a rotary type or a vane type, and the motor 112 is different from the three-phase brushless DC motor. An AC motor or the like may be used.

  Moreover, in the said embodiment, although applied to the general electric compressor 110, not only this but the case where the compression mechanism 111 is driven by drive sources other than the motor 112 via power transmission devices, such as a belt, The present invention can also be applied to a hybrid type compressor that can switch between the case where the compression mechanism 111 is driven by the motor 112.

10 Vehicle air conditioner (air conditioner)
DESCRIPTION OF SYMBOLS 100 Refrigeration cycle 110 Electric compressor 111 Compression mechanism 112 Motor 113 Inverter circuit (motor drive circuit)
DESCRIPTION OF SYMBOLS 120 Condenser 121 Cooling fan 150 Evaporator 151 Blower 200 Control apparatus 320 Inside / outside air switching door (switching means)

Claims (9)

A compression mechanism (111) for sucking and compressing the refrigerant and an electric motor (112) for driving the compression mechanism (111) are integrally formed, and the suction refrigerant sucked by the compression mechanism (111) A refrigeration cycle (100) comprising an electric compressor (110) in which a motor drive circuit (113) for driving the motor (112) is cooled;
In the air conditioner having the motor drive circuit (113) and the control device (200) for controlling the operation of the refrigeration cycle (100),
When the temperature (Ti) of the motor drive circuit (113) exceeds a predetermined temperature even when the compression mechanism (111) is stopped, the control device (200) is controlled by the motor drive circuit (113). The motor (112) is operated to bring the compression mechanism (111) into an operating state, and the supply condition of the air that exchanges heat with the refrigerant flowing through the refrigeration cycle (100) is varied to change the temperature of the intake refrigerant. The air conditioner characterized by lowering.   The variable of the air supply condition increases the amount of cooling air supplied to the refrigerant condensing condenser (120) provided in the refrigeration cycle (100). Air conditioner. The condenser (120) is provided with a cooling fan (121) for supplying the cooling air,
The air conditioner according to claim 2, wherein the increase in the amount of cooling air is performed by increasing the capacity of the cooling fan (121).   The variable air supply condition reduces the air amount of air-conditioning air supplied to a refrigerant evaporation evaporator (150) provided in the refrigeration cycle (100). The air conditioner described. A blower (151) for supplying the air for air conditioning to the evaporator (150);
The air conditioner according to claim 4, wherein the reduction of the air amount of the air for air conditioning is executed by lowering the capacity of the blower (151). The air conditioning air supplied to the refrigerant evaporation evaporator (150) provided in the refrigeration cycle (100) has switching means (320) for selecting either indoor air or outdoor air,
The air supply condition can be changed by supplying air for air conditioning to the evaporator (150), and by the switching means (320), the air having the lower temperature of the indoor air and the outdoor air. The air conditioner according to claim 1, wherein the air conditioner is selected. The air conditioning air supplied to the refrigerant evaporation evaporator (150) provided in the refrigeration cycle (100) has switching means (320) for selecting either indoor air or outdoor air,
The air supply condition can be varied by supplying air for air conditioning to the evaporator (150) and selecting the indoor air from the indoor air and the outdoor air by the switching means (320). The air conditioner according to claim 1.   The air conditioner according to any one of claims 1 to 7, wherein the motor drive circuit (113) is integrally formed with the electric compressor (110).   The air conditioner according to any one of claims 1 to 8, wherein the refrigeration cycle (100) and the control device (200) are used for a vehicle.

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