JP4985534B2 - Lubricating oil judgment device - Google Patents

Description

  The present invention relates to a lubricating oil determination device.

Conventionally, when an electric compressor is used in a refrigeration cycle device for a vehicle, oil that maintains a high electric resistance value even when mixed with refrigerant is used as lubricating oil mixed in the refrigerant.

  Generally, as a lubricating oil for an engine-driven compressor, an oil whose electric resistance value is reduced by being combined with the refrigerant when mixed with the refrigerant is used.

Also, an insulation monitoring unit suitable for detecting the insulation resistance of the electric compressor is disclosed (for example, see Patent Document 1).
JP 2004-104923 A

  In the vehicle refrigeration cycle apparatus including the above-described electric compressor, when lubricating oil for an engine-driven compressor is mistakenly mixed in the refrigerant, the electric resistance value of the mixed refrigerant is reduced, and the electric compressor is insulated. There arises a problem that the resistance decreases.

  An object of the present invention is to provide a lubricating oil determination device that can determine whether lubricating oil other than lubricating oil for an electric compressor is mixed in a refrigerant.

In order to achieve the above object, according to the first aspect of the present invention, the housing (11), the compression mechanism (30) disposed in the housing and compressing the refrigerant, and the compression mechanism (30) disposed in the housing are driven. And an inverter circuit (40) for outputting an alternating current to a stator coil (15) of the motor by a switching operation based on a voltage output from the battery, and an insulation for detecting an insulation resistance of the electric compressor Resistance monitoring means (1c);
Oil mixing determination means (S250) for determining whether lubricating oil other than lubricating oil for an electric compressor is mixed in the refrigerant based on a detection value of the insulation resistance monitoring means. .

  Thereby, it can be determined whether lubricating oil other than lubricating oil for electric compressors is mixed in the refrigerant.

In the invention according to claim 1 , the insulation resistance monitoring means (1c) outputs an output signal to the inverter circuit (40) and detects the insulation resistance based on the attenuation amount of the output signal. And
The inverter circuit (40) has a plurality of switching elements (SW1, SW2,... SW6) that output an alternating current to the stator coil (15) in accordance with switching.
First detection means (S200) for causing the insulation resistance monitoring means to detect a first detection value (R1) as the insulation resistance in a state where each of the plurality of switching elements is turned off;
Before the motor drives the compression mechanism, a switching element between the insulation resistance monitoring means and the stator coil (15) is turned on among the plurality of switching elements, and the insulation resistance monitoring means and the stator coil are turned on. (2) second detection means (S220) for detecting the second detection value (R2) as the insulation resistance by the insulation resistance monitoring means in a state in which the potential difference from (15) is eliminated;
Third detection means for detecting a third detection value (R3) as the insulation resistance by the insulation resistance monitoring means when the motor drives the compression mechanism and the stagnation of the refrigerant is eliminated in the housing. (S240)
The oil mixing determination means determines whether lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant based on the first, second, and third detection values. To do.

In the invention which concerns on Claim 2 , the said oil mixing determination means (S250)
A first absolute value (ΔR12) of a difference between the first detection value (R1) and the second detection value (R2) is not less than a first predetermined value (K1), and the third detection value. A second absolute value (ΔR32) of a difference between (R3) and the second detection value (R2) is equal to or greater than a second predetermined value (K2), and further, the third detection value (R3) and the second detection value (R3) When the third absolute value (ΔR31) of the difference from the detected value (R1) of 1 is within a predetermined range, it is determined that lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant. It is characterized by doing.

In the invention which concerns on Claim 3 , the said inverter circuit (40) outputs the said alternating current to the said stator coil (15) by using the output voltage of a power supply device as an input voltage,
An electrolytic capacitor (45) for stabilizing an output voltage output from the power supply device to the inverter circuit (40);
Before the motor drives the compression mechanism, the switching elements (SW4, SW5, SW6) between the insulation resistance monitoring means and the stator coil (15) among the plurality of switching elements are turned on and the insulation is performed. Charge / discharge control means (S320) for controlling the plurality of switching elements so as to charge / discharge the electrolytic capacitor in a state where the potential difference between the resistance monitoring means and the stator coil (15) is eliminated;
When the charge / discharge control unit controls the plurality of switching elements to charge / discharge the electrolytic capacitor in a state in which the potential difference between the insulation resistance monitoring unit and the stator coil (15) is eliminated, The second detection means causes the insulation resistance monitoring means to detect the second detection value (R2).

  Thereby, the self-heating of the electrolytic capacitor can be promoted by charging and discharging the electrolytic capacitor. For this reason, the electrolytic capacitor can be operated satisfactorily even at low temperatures.

In the invention which concerns on Claim 4 , it comprises the temperature determination means (S300) which determines whether the temperature of the said electrolytic capacitor is below predetermined temperature,
When the temperature determination unit determines that the temperature of the electrolytic capacitor is equal to or lower than a predetermined temperature, the charge / discharge control unit eliminates the potential difference between the insulation resistance monitoring unit and the stator coil (15). The plurality of switching elements are controlled so that the electrolytic capacitor is charged and discharged, and the second detection unit causes the insulation resistance monitoring unit to detect the second detection value (R2).

In the invention which concerns on Claim 5 , it comprises the stagnation cancellation determination means (S230) which determines whether the stagnation of the refrigerant | coolant was eliminated in the said housing,
The third detection means causes the insulation resistance monitoring means to detect the third detection value (R3) when the stagnation elimination determination means determines that the stagnation of the refrigerant has been eliminated in the housing. And

The invention according to claim 6 is characterized in that the stagnation elimination determination means determines that the stagnation of the refrigerant is eliminated in the housing when the fluctuation of the rotational torque of the motor falls within a predetermined range. .

The invention according to claim 7 is characterized in that the stagnation elimination determination means determines that the stagnation of the refrigerant is eliminated in the housing when the fluctuation of the angular velocity of the motor falls within a predetermined range.

The invention according to claim 8 is characterized in that the stagnation elimination determination means determines that the stagnation of the refrigerant has been eliminated in the housing after a predetermined period or more has elapsed after the motor starts driving the compression mechanism. To do.

In the invention according to claim 9, when the predetermined time has elapsed after the electric compressor is stopped, the first, second, and third detection means respectively detect the insulation resistance by the insulation resistance monitoring means. It is characterized by.

In the invention which concerns on Claim 10 , the said electric compressor comprises the refrigeration cycle apparatus which circulates the said refrigerant | coolant,
The refrigeration cycle apparatus includes an outdoor heat exchanger (110) that cools a refrigerant discharged from the electric compressor with outdoor air, a decompressor (120) that decompresses the refrigerant cooled by the outdoor heat exchanger, and the decompression An indoor heat exchanger (130) for evaporating the refrigerant decompressed by the chamber with room air,
First temperature detecting means (200) for detecting the temperature of the outdoor air;
Second temperature detecting means (210) for detecting the temperature of the indoor air,
When the difference between the detected temperature of the first detecting means and the detected temperature of the indoor air is equal to or greater than a predetermined value, the first, second and third detecting means are Each of the resistors is detected.

In the invention which concerns on Claim 11, after the said 3rd detection means detects the said 3rd detection value (R3) by the said insulation resistance monitoring means, when the said electric compressor stops and the predetermined period passes. The first and second detection means are configured to detect the first and second detection values (R1, R2) by the insulation resistance monitoring means,
The oil mixing determination means determines whether lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant based on the first, second, and third detection values. To do.

In the invention according to claim 12 , a memory (1b) for storing a self-diagnosis history;
Alarm means (1d) for issuing an alarm;
Insulation resistance determination means (S270) for determining whether the detected insulation resistance of the insulation resistance monitoring means is less than a certain value;
When the oil mixing determination means determines that lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant, and the detected insulation resistance of the insulation resistance monitoring means is less than a certain value, the insulation resistance determination means Is determined, alarm control means for controlling the alarm means (S280),
When the oil mixing determination means determines that lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant, and the detected insulation resistance of the insulation resistance monitoring means is a certain value or more, the insulation resistance determining means Storage control means (S260) for storing in the memory as the self-diagnosis history that lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant.
It is characterized by providing.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

  FIG. 1 shows an embodiment of an air conditioning system for a hybrid vehicle according to the present invention.

  The air conditioning system includes a hybrid ECU 1 and an air conditioner ECU 2. The hybrid ECU 1 includes a microcomputer 1a and a memory 1b.

  The microcomputer 1a performs communication processing with each of the air conditioner ECU 2, the electric compressor drive device 20, the battery ECU 1c, and the meter ECU 1e, and determination processing for determining erroneous mixing of lubricating oil, which will be described later. The memory 1b stores various data in addition to the computer program.

  The meter ECU 1e includes an alarm device 1d for alarming an occupant in addition to the vehicle speedometer and the engine tachometer. The alarm device 1d is an alarm means such as an alarm lamp or a buzzer.

  The battery ECU 1c constitutes an insulation resistance monitoring means for monitoring the insulation resistance of the electric compressor, and its specific configuration is disclosed in Patent Document 1 and will be briefly described below.

Battery ECU 1c includes signal source 5a, filter circuit 5d, and peak hold circuit 5e. Signal source 5a is connected to negative-side bus 41 (see FIG. 4) of inverter circuit 40 through resistance element 5b and capacitor 5c. The signal source 5a outputs an oscillation signal that oscillates at a predetermined cycle and whose voltage value periodically changes. The filter circuit 5d uses the voltage value at the common connection point between the resistance element 5b and the capacitor 5c as an input signal, and shapes the waveform of the input signal.

  The peak hold circuit 5e holds the peak value (see HS in FIG. 1) of the output signal of the filter circuit 5d and outputs this peak value to the microcomputer 1a of the hybrid ECU 1.

  Here, as the insulation resistance of the electric compressor 100 decreases, the output signal of the filter circuit 5d attenuates, so that the peak value held by the peak hold circuit 5e decreases. On the other hand, as the insulation resistance increases, the attenuation amount of the output signal of the filter circuit 5d decreases, so that the peak value held by the peak hold circuit 5e increases.

  Thus, the battery ECU 1c detects the peak value of the output signal of the filter circuit 5d as the insulation resistance of the electric compressor 100.

  As shown in FIG. 2, the electric compressor 100 constitutes a refrigeration cycle apparatus together with a condenser 110, a decompressor 120, and an evaporator 130. The electric compressor 100 and the condenser 110 are disposed in the engine room (outside the vehicle compartment). The decompressor 120 and the evaporator 130 are disposed in the passenger compartment.

  The electric compressor 100 sucks, compresses, and discharges the refrigerant. Lubricating oil is dissolved in this refrigerant. The specific structure of the electric compressor 100 will be described later.

  The condenser 110 is an outdoor heat exchanger that cools and condenses the refrigerant discharged from the electric compressor 100 by outside air (air outside the vehicle compartment). The decompressor 120 decompresses the refrigerant cooled by the condenser 110. The evaporator 130 is an indoor heat exchanger that evaporates the refrigerant from the decompressor 120 from the inside air (vehicle interior air) by an endothermic action.

Next, a specific structure of the electric compressor 100 will be described with reference to FIG.
FIG. 3 is a view showing the inside of the electric compressor.

  The electric compressor 100 includes a motor 10, a driving device 20, and a compression mechanism 30. The motor 10 rotationally drives the compression mechanism 30 via the rotary shaft 12.

  The motor 10 is a three-phase AC synchronous motor including a housing 11, a rotating shaft 12, a rotor 13, a stator core 14, and a stator coil 15. The housing 11 is made of a metal such as aluminum and has a substantially cylindrical shape. The housing 11 is provided with a suction port 11a and a discharge port 11b.

  The rotating shaft 12 is disposed in the housing 11 and is rotatably supported by bearings 12a and 12b. The rotating shaft 12 transmits the rotational driving force received from the rotor 13 to the compression mechanism 30. The bearing 12 a is supported by the housing 11 via the support portion 120. The bearing 12 b is supported by the bottom wall of the housing 11.

  The rotor 13 is made of a permanent magnet, is formed in a cylindrical shape, and is fixed to the rotating shaft 12. The rotor 13 rotates together with the rotating shaft 12 based on the rotating magnetic field generated from the stator core 14.

  The stator core 14 is disposed on the outer peripheral side in the radial direction with respect to the rotor 13 (rotating shaft 12) and is formed in an annular shape in the housing 11. The stator core 14 is made of a magnetic material such as ferrite and is supported from the inner peripheral surface of the housing 11.

  The stator coil 15 has a U-phase coil, a V-phase coil, and a W-phase coil and is star-connected, and is wound around the stator core 14. The U-phase coil, V-phase coil, and W-phase coil are connected to the drive device 20 via the terminal 17.

  Three terminals 17 are provided corresponding to each of the U-phase coil, the V-phase coil, and the W-phase coil. The three terminals 17 are fitted into the opening 11 c of the housing 11.

  Although one terminal 17 is shown in FIG. 3, the other two terminals 17 are omitted.

  The compression mechanism 30 is a scroll type compressor, and is rotated by the rotational driving force from the rotating shaft 12 of the motor 10 to suck, compress, and discharge the refrigerant. The driving device 20 is disposed on the outer surface of the housing 11. The driving device 20 constitutes an electric circuit that drives the motor 10. FIG. 4 shows an electric circuit configuration of the driving device 20.

  The drive device 20 includes an inverter circuit 40, a control circuit 50, and a temperature sensor 60. Inverter circuit 40 outputs a three-phase alternating current to stator coil 15 based on the output voltage of power supply device B.

  The inverter circuit 40 includes switching elements SW1, SW2, SW3, SW4, SW5, and SW6 and diodes D1, D2, D3, D4, D5, and D6.

  The switching elements SW1 and SW4 are connected in series between the negative side bus 41 and the positive side bus 42, and the switching elements SW2 and SW5 are connected in series between the negative side bus 41 and the positive side bus 42, and the switching elements SW3, SW3, The SW 6 is connected in series between the negative side bus 41 and the positive side bus 42. The negative electrode side bus 41 is connected to the battery ECU 1c.

  The common connection point T1 of the switching elements SW1 and SW4 is connected to the W-phase coil 1w, the common connection point T2 of the switching elements SW2 and SW5 is connected to the V-phase coil 1v, and the common connection point T3 of the switching elements SW3 and SW6. Is connected to the U-phase coil 1u.

  As the switching elements SW1, SW2,... SW6, for example, semiconductor switching elements such as insulated gate bipolar transistors and field effect transistors are used.

  The diodes D1, D2, D3, D4, D5, and D6 are disposed so as to be in antiparallel to the corresponding switching element among the switching elements SW1, SW2, SW3, SW4, SW5, and SW6.

  A power supply device B and a capacitor 45 are connected in parallel between the negative side bus 41 and the positive side bus 42. The capacitor 45 is an electrolytic capacitor, and constitutes a filter circuit that stabilizes the voltage output from the power supply device B to the inverter circuit 40. The control circuit 50 controls the switching elements SW1, SW2, SW3, SW4, SW5, and SW6. The temperature sensor 60 detects the temperature of the substrate on which the capacitor 45 is mounted as the ambient temperature of the capacitor 45.

In the present embodiment configured as described above, the refrigerant generally has a characteristic of accumulating at a location where the temperature is low. Since the temperature of the electric compressor 100 in the engine room tends to be lower than that of the evaporator 130 in the passenger compartment, the refrigerant accumulates on the suction port 11a side of the electric compressor 100 and the refrigerant stagnates in the housing 11. May occur. For this reason, as shown in FIG. 5 (c), the refrigerant may be immersed in the missing portion of the insulating coating of the stator coil 15 or the conductive exposed portion of the terminal 17 in the housing 11. In addition, the hatched part in FIG.5 (c) shows a refrigerant | coolant.

  Here, when engine-driven compressor lubricating oil other than the electric compressor lubricating oil is mixed in the refrigerant, the insulation resistance value of the refrigerant mixed with the engine-driven compressor lubricating oil decreases (FIG. 6). (See middle graph b).

  In FIG. 6, the resistance values (MΩ) on the vertical axis and the weight ratio of the refrigerant to the lubricating oil (= (lubricating oil) / (lubricating oil + refrigerant)) on the horizontal axis are graphs a, b, and c. Show. Graph c is an insulation resistance value of a refrigerant in which lubricating oil for engine-driven compressors is dissolved.

  Graph b shows the insulation resistance value of the refrigerant when the engine-driven compressor lubricating oil is mixed with the refrigerant in which the electric compressor lubricating oil is dissolved. Graph b is an insulation resistance value when the weight of the lubricating oil for engine-driven compressor mixed in the refrigerant is 1% when the weight of the lubricating oil for electric compressor is 100%. Graph a is an insulation resistance value of a refrigerant in which lubricating oil for an electric compressor is dissolved.

  In the present embodiment, the lubricating oil for the electric compressor is, for example, a POE (Polyol ester) oil, and the lubricating oil for the engine-driven compressor is, for example, a PAG (Polyalkylene Glycol) oil. The refrigerant is R134.

  In this way, since the insulation resistance value of the refrigerant mixed with the engine-driven compressor lubricating oil is small, as shown in the equivalent circuit on the motor 10 side in FIG. For this reason, the insulation resistance value of the electric compressor 100 decreases.

  In addition, resistance components RT1, RT2, and RT3 in FIG. 7 are equivalent resistance components for each phase generated between the terminal 17 and the housing 11 through the refrigerant, and the capacitance components CT1, CT2, and CT3 are through the refrigerant. This is an equivalent capacity component for each phase generated between the terminal 17 and the housing 11.

  The resistance component R0 is an equivalent resistance component generated between the stator core 14 and the housing 11 via the refrigerant, and the capacity component C0 is an equivalent capacity component generated between the stator core 14 and the housing 11 via the refrigerant.

  As described above, when engine-driven compressor lubricating oil different from the lubricating oil to be originally used is mixed, the refrigerant (lubricant) is contained in the housing 11 until the refrigerant is immersed in the missing portion of the insulating coating of the stator coil 15 or the terminal 17. When the oil (including oil) fell asleep, the leakage current could increase.

  Therefore, in the present embodiment, the hybrid ECU 1 executes determination processing for determining whether lubricating oil other than the lubricating oil for the electric compressor is erroneously mixed in the refrigerant.

  Hereinafter, specific processing of the hybrid ECU 1 will be described with reference to FIG.

  FIG. 8 is a flowchart showing processes of the hybrid ECU 1, the air conditioner ECU 2, and the drive device 20 of the electric compressor 100.

  First, in step S100, the air conditioner ECU 2 instructs the drive device 20 of the electric compressor 100 to rotate according to the target rotational speed through the hybrid ECU 1.

  At this time, the control circuit 50 of the driving device 20 maintains all the switching elements SW1, SW2,... SW6 of the inverter circuit 40 in the off state until receiving a permission signal described later.

  At this time, the microcomputer 1a of the hybrid ECU 1 detects the insulation resistance R1 by the battery ECU 1c in step S200 as the first detection means.

  Here, since each of switching elements SW4, SW5, and SW6 is in an OFF state, there is a potential difference between stator coil 15 (that is, U-phase coil, V-phase coil, and W-phase coil) and the output portion of battery ECU 1c. Has occurred.

  For this reason, the output signal of the battery ECU 1c does not reach the common connection points T1, T2, T3 from the negative bus 41. Therefore, it is impossible to detect the insulation resistance on the motor 10 side, that is, the insulation resistance that is lowered as the stator coil 15 and the terminal 17 are immersed in the refrigerant as described above. For this reason, the detected value (dotted line in FIG. 5) of the battery ECU 1c is different from the actual insulation resistance (solid line in FIG. 5).

  Next, the control circuit 50 of the driving device 20 determines whether or not the temperature of the capacitor 45 is low in step S300. Specifically, when the detected value of the temperature sensor 60 is equal to or higher than a predetermined temperature (for example, 0 degrees), it is determined that the temperature of the capacitor 45 is not low and NO is determined in step S300, and the process proceeds to step S310.

  At this time, the control circuit 50 turns on the switching elements SW4, SW5, and SW6 on the negative side bus 41 side with the switching elements SW1, SW2, and SW3 on the positive side bus 42 side turned off, respectively.

  Here, as the switching elements SW4, SW5, and SW6 are turned on, the potential difference between the common connection points T1, T2, and T3 and the output unit of the battery ECU 1c disappears.

  On the other hand, when the detected value of the temperature sensor 60 is lower than the predetermined temperature, the control circuit 50 determines that the temperature of the capacitor 45 is low and determines YES in step S300, and proceeds to step S320. At this time, the control circuit 50 controls the switching elements SW1, SW2,... SW6 in order to warm up the capacitor 45 while the motor 10 is stopped as charge / discharge control means.

  Specifically, as shown in FIG. 9, the switching element SW3 is switched with the switching elements SW1, SW2, SW5, and SW6 turned off and the switching element SW4 on the negative bus 41 side turned on.

  Here, as the switching element SW4 is turned on, the potential difference between the common connection point T1 and the output unit of the battery ECU 1c disappears.

  Here, when switching element SW3 is turned on, the discharge current from capacitor 45 flows to negative electrode side bus 41 through switching element SW3, U-phase coil 1u, W-phase coil 1w and switching element SW4. On the other hand, when the switching element SW3 is turned off, a charging current flows from the power supply device B to the capacitor 45.

  As described above, the capacitor 45 is charged and discharged as the switching element SW3 is switched, and the capacitor 45 itself generates heat. For this reason, the temperature of the capacitor 45 rises.

  As described above, when the control process of any one of step S310 and step S320 is being executed, the microcomputer 1a of the hybrid ECU 1 operates as the second detection unit by the battery ECU 1c in step S220. R2 is detected.

  Here, when the switching element SW4 is turned on, as described above, there is no potential difference between the common connection point T1 and the output part of the battery ECU 1c. For this reason, the output signal of the battery ECU 1c reaches the stator coil 15 through the diode D4. Therefore, the insulation resistance on the motor 10 side can be detected by the battery ECU 1c.

  Further, when the switching elements SW4, SW5, SW6 are turned on, as described above, there is no potential difference between the common connection points T1, T2, T3 and the output part of the battery ECU 1c. For this reason, the output signal of the battery ECU 1c reaches the stator coil 15 through the diodes D4, D5, and D6. Therefore, the insulation resistance on the motor 10 side can be detected by the battery ECU 1c.

  As described above, the insulation resistance on the motor 10 side can be detected as the insulation resistance R2.

  On the other hand, the control circuit 50 of the drive device 20 controls the inverter circuit 40 so as to rotate the motor 10 at the target rotational speed in step S330.

  At this time, the switching elements SW1, SW2,... SW5, SW6 perform a switching operation, so that a three-phase alternating current is output from the common connection points T1, T2, T3 to the stator coil 15 through the three terminals 17. The angular velocity of the three-phase alternating current corresponds to the target rotational speed described above.

  Along with this, a rotating magnetic field is generated in the stator coil 15. For this reason, the rotor 13 rotates in synchronization with the rotating magnetic field. Along with this, the rotating shaft 12 rotates according to the target rotational speed to drive the compression mechanism 30 (see FIG. 5A). Therefore, the compression mechanism 30 sucks, compresses, and discharges the refrigerant by the driving force of the rotating shaft 12.

  Along with this, the refrigerant from the evaporator 130 side flows into the suction port 11a side of the housing 11, and the refrigerant flows as shown by arrows in FIG. This refrigerant is compressed by the compression mechanism 30 and discharged from the discharge port 11b. Therefore, as shown in FIG. 5D, the amount of refrigerant that has fallen into the housing 11 is reduced. In addition, the oblique line in FIG.5 (d) shows a refrigerant | coolant.

  Next, in step S230, the microcomputer 1a of the hybrid ECU 1 determines whether or not the stagnation of the refrigerant in the housing 11 of the electric compressor 100 has been eliminated as stagnation elimination determination means.

  Specifically, it is determined whether or not a certain period Ta or more has elapsed after the processing in step S210. This means that the motor 10 determines whether or not a certain period Ta or more has elapsed after starting to drive the compression mechanism 30.

  When the elapsed time after the process of step S210 is shorter than the predetermined period Ta, it is determined as NO because the refrigerant stagnation in the housing 11 has not been eliminated, and the determination of step S230 is repeated.

  Thereafter, when a predetermined period Ta or more has elapsed after the processing in step S210, it is determined YES in step S230 because the stagnation of the refrigerant in the housing 11 has been eliminated. Then, it progresses to step S240 and the insulation resistance R3 is detected by battery ECU1c as a 3rd detection means.

  Here, in the process of step S330 described above, one of the switching elements SW4, SW5, and SW6 is turned on. For this reason, as in the case of step S220, the insulation resistance on the motor 10 side can be detected as the insulation resistance R3.

  Next, in step S250, the microcomputer 1a of the hybrid ECU 1 determines whether or not lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant based on the insulation resistances R1, R2, and R3.

  First, an absolute value | ΔR12 | of a difference ΔR12 (= R1−R2) between the insulation resistance R1 and the insulation resistance R2 is obtained, and it is determined whether or not the absolute value | ΔR12 | is equal to or greater than a first predetermined value (K1). To do.

  Next, an absolute value | ΔR32 | of a difference ΔR32 (= R3−R2) between the insulation resistance R3 and the insulation resistance R2 is obtained, and it is determined whether or not the absolute value | ΔR32 | is equal to or greater than a second predetermined value K2. .

  Further, an absolute value | ΔR31 | of a difference ΔR31 (= R3−R1) between the insulation resistance R3 and the insulation resistance R1 is obtained, and it is determined whether or not the absolute value | ΔR31 | is within the predetermined range W.

  Here, the absolute value | ΔR12 | is greater than or equal to the first predetermined value (K1), the absolute value | ΔR32 | is greater than or equal to the second predetermined value K2, and the absolute value | ΔR31 | is within the predetermined range W. If YES, it is determined that the lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant, and YES is determined in step S250.

  In this case, the process proceeds to step S260, and the fact that the lubricating oil other than the lubricating oil for the electric compressor is erroneously mixed in the refrigerant is recorded in the memory 1b as a diagnostic history of the self-diagnosis.

  When the absolute value | ΔR12 | is less than the first predetermined value (K1), only normal lubricating oil for the electric compressor is dissolved in the refrigerant, and lubricating oil other than the normal lubricating oil is erroneously mixed in the refrigerant. If not, NO is determined in step S250.

  When the absolute value | ΔR32 | is less than the second predetermined value K2, it is assumed that only normal lubricating oil for the electric compressor is dissolved in the refrigerant and that lubricating oil other than the normal lubricating oil is not mistakenly mixed in the refrigerant. In step S250, NO is determined.

  When the absolute value | ΔR31 | is larger than the upper limit value of the predetermined range W, the insulation resistance of an electrical device other than the inverter circuit 40 (for example, an inverter circuit for a traveling motor) among the electrical devices to which the power supply device B is connected. As a result of the decrease, NO is determined in step S250.

  When the absolute value | ΔR31 | is smaller than the lower limit value of the predetermined range W, it is determined that the detection values R1 and R3 of the battery ECU 1c are incorrect values due to noise or the like, and NO is determined in step S250.

  According to the present embodiment described above, the hybrid ECU 1 determines whether or not lubricating oil other than the lubricating oil for the electric compressor is erroneously mixed in the refrigerant using the insulation resistances R1, R2, and R3 as described above. When it is determined that the lubricating oil other than the lubricating oil for the electric compressor is erroneously mixed in the refrigerant, the lubricating oil other than the lubricating oil for the electric compressor is erroneously mixed in the refrigerant as a self-diagnosis history in the memory 1b. Record that it is.

  In a general hybrid vehicle, even if lubricating oil other than the lubricating oil for the electric compressor is mistakenly mixed with the refrigerant, the electric compressor 100 is fixed to the chassis via the traveling engine without affecting the lubrication of the electric compressor 100. Therefore, as long as the main body of the electric compressor 100 functions as an enclosure, the decrease in safety is small. However, by storing the self-diagnosis history (diag history) in the memory 1b, the enclosure is not damaged at the time of disassembly and maintenance. Attention can be encouraged and cleaning of the refrigeration cycle can be recommended during regular inspections.

  On the other hand, when the diagnosis history that the lubricating oil other than the lubricating oil for the electric compressor is erroneously mixed in the refrigerant is not stored in the memory 1b, it is possible to prevent the compressor from being replaced more than necessary. Can do.

  In the present embodiment, when the battery ECU 1c detects the insulation resistance R2, the capacitor 45 itself is heated by charging and discharging the capacitor 45, and the temperature of the capacitor 45 is increased.

  Here, when an electrolytic capacitor is used as the capacitor 45 of the power input section (filter circuit) of the inverter circuit 40, the equivalent series resistance (ESR) of the electrolytic capacitor increases when the electrolytic capacitor is at a low temperature, and the electrolytic current is caused by the ripple current. The voltage fluctuation between both terminals increases. In order to prevent the voltage fluctuation from exceeding the allowable value, it is necessary to limit the current. However, in order to discharge the liquid refrigerant and oil that have fallen from the inside of the housing 11, the motor 10 needs a large driving torque. It is necessary to pass a large current through the motor 10.

  In this embodiment, before driving the motor 10, when the battery ECU 1c detects the insulation resistance R2, the equivalent series resistance of the electrolytic capacitor is reduced by encouraging self-heating of the electrolytic capacitor by charging and discharging the capacitor 45. A necessary current can be supplied to the motor 10.

  At this time, since the motor 10 is stopped, the monitoring of the insulation resistance R2 is not hindered in a state where the refrigerant has stagnated in the housing 11. Further, since the operation of the capacitor 45 at −10 ° C. or more where the efficiency of the refrigerant R134a is reduced can be ensured, there is almost no contradiction due to the use of an electrolytic capacitor as the capacitor 45, which is advantageous for downsizing and cost reduction.

(Other embodiments)
In the above-described embodiment, when it is determined that the lubricating oil other than the lubricating oil for the electric compressor is erroneously mixed in the refrigerant, the lubricating oil other than the lubricating oil for the electric compressor is mistakenly stored as the self-diagnosis history in the memory 1b. Although an example in which the fact that it has been mixed is shown, it may be replaced with the following.

  In this case, the hybrid ECU 1 performs a determination process according to the flowchart of FIG.

  That is, when it is determined YES in step S250 that lubricating oil other than the lubricating oil for the electric compressor is erroneously mixed in the refrigerant, in the next step S270, the insulation resistance of the electric compressor 100 is determined as an insulation resistance determining means. It is determined whether it is below a certain level.

  Specifically, it is determined whether or not the absolute value | ΔR12 | is equal to or greater than a threshold value K12 (> K1). Next, it is determined whether or not the absolute value | ΔR32 | is equal to or greater than a threshold value K22 (> K2).

  Here, when the absolute value | ΔR12 | is equal to or greater than the threshold value K12 (> K1) and the absolute value | ΔR32 | is equal to or greater than the threshold value K22 (> K2), it is assumed that the insulation resistance of the electric compressor 100 is less than a certain level. It determines with YES in step S270.

  Accordingly, the alarm device 1d is controlled via the meter ECU 1e (alarm control means). At this time, the alarm device 1d warns the user that the insulation resistance of the electric compressor 100 is less than a certain level.

  Thereby, for example, in the case of a plug-in hybrid vehicle, it is possible to warn the user before leakage occurs during charging and the leakage breaker on the AC power supply side operates.

  On the other hand, when the absolute value | ΔR12 | is less than the threshold value K12 (> K1) or the absolute value | ΔR32 | is less than the threshold value K22 (> K2), it is determined that the insulation resistance of the electric compressor 100 is equal to or higher than a certain level. Then, the process proceeds to step S260, and the fact that lubricating oil other than the lubricating oil for the electric compressor is erroneously mixed in the refrigerant is recorded in the memory 1b as a self-diagnosis history.

In the above-described embodiment, an example is shown in which it is determined whether or not the stagnation of the refrigerant in the housing 11 of the electric compressor 100 has been eliminated by determining whether or not a certain period Ta has elapsed after the processing of step S210. However, the following may be used instead.
(1) It is determined whether or not the fluctuation of the rotational torque of the motor 10 is within a predetermined range, and when it is determined that the fluctuation of the rotational torque of the motor 10 is within the predetermined range TW, the refrigerant stagnation in the housing 11 Is determined to have been resolved. The rotational torque is estimated based on the three-phase alternating current output from the inverter circuit 40 to the stator coil 15. In this case, it is necessary to use a current detection sensor that detects a three-phase alternating current.
(2) It is determined whether or not the fluctuation of the angular velocity (ω) of the motor 10 is within a predetermined range. When the fluctuation of the angular velocity (ω) of the three-phase alternating current falls within a predetermined range, it is determined that the refrigerant stagnation in the housing 11 has been eliminated. The angular velocity is estimated based on the three-phase alternating current output from the inverter circuit 40 to the stator coil 15. In this case, it is necessary to use a current detection sensor that detects a three-phase alternating current.

  As described in the above (1) and (2), it is determined whether or not the refrigerant stagnation has been eliminated by the fluctuation of the rotational torque of the motor 10 or the fluctuation of the angular velocity. Therefore, the determination can be performed with high accuracy. Thus, the delay time of the determination timing can be shortened in determining that the refrigerant stagnation has been eliminated immediately after the electric compressor 100 is started. Therefore, when the battery ECU 1c detects the insulation resistance R3, it is possible to avoid interference of electrical devices other than the inverter circuit 40 connected to the power supply device B.

  In the above-described embodiment, the example in which the control circuit 50 performs the determination in step S300 using the detection value of the temperature sensor 60 has been described, but instead, the control circuit 50 is based on the operating state of the inverter circuit 40. The internal temperature of the capacitor 45 may be estimated, and the determination in step S300 may be performed using this estimated temperature.

  In the above-described embodiment, the insulation resistances R1, R2, and R3 may be detected by the battery ECU 1c when a predetermined time or more has elapsed after the electric compressor 100 is stopped.

  This is because the stagnation phenomenon of the refrigerant in the housing 11 of the electric compressor 100 does not occur unless a predetermined time or more elapses after the electric compressor 100 stops.

  Further, when the refrigerant temperature is low, the refrigerant in the housing 11 of the electric compressor 100 tends to stagnate, but when the refrigerant temperature is high, the refrigerant in the housing 11 of the electric compressor 100 hardly stagnates. Therefore, in the above-described embodiment, the insulation resistances R1, R2, and R3 may be detected by the battery ECU 1c only when the refrigerant temperature is low.

  In the above-described embodiment, the example in which the insulation resistances R1, R2, and R3 are detected regardless of the temperature difference between the inside and outside air has been shown. Instead, the detection value Tam of the outside air temperature sensor 200 (see FIG. 1). The absolute value | ΔT | (= | Tam−Tr |) of the difference ΔT between the detected value Tr and the detected value Tr of the internal air temperature sensor 210 is obtained, and when the absolute value | ΔT | R3 may be detected. This is because a refrigerant stagnation phenomenon in the housing 11 of the electric compressor 100 is likely to occur when the temperature difference between the inside and outside air is large.

  The outside air temperature sensor 200 and the inside air temperature sensor 210 may be independently connected to a communication network, but those connected to other ECUs may be used. For example, a temperature sensor 60 of an electric compressor can be used instead of the outside air temperature sensor. In this case, the hybrid ECU 1 needs to acquire detection values corresponding to the sensors 200 and 210 via a communication network to which other ECUs are connected.

  Here, the outside air temperature sensor 200 is a first temperature detecting means for detecting the air temperature outside the passenger compartment, and the inside air temperature sensor 210 is a second temperature detecting means for detecting the air temperature inside the passenger compartment.

  In the above-described embodiment, the example in which the insulation resistance R3 is detected by the battery ECU 1c after the insulation resistance R1 and R2 are detected by the battery ECU 1c has been described, but instead, the electric compressor 100 is detected after the insulation resistance R3 is detected. Insulation resistances R2 and R1 may be detected by the battery ECU 1c when a predetermined period of time elapses.

In this case, if the insulation resistances R2 and R1 are detected by the battery ECU 1c with the power switch (ignition switch) of the hybrid vehicle turned off,
It can be determined whether or not lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant during the period when the power switch is off.

  In the above-described embodiment, the output unit of the battery ECU 1c is connected to the negative side bus 41 of the inverter circuit 40. Instead, the output unit of the battery ECU 1c is connected to the positive side bus 42 of the inverter circuit 40. May be.

  In the above-described embodiment, an example in which a three-phase AC synchronous motor is used as the motor 10 has been shown, but a motor other than the three-phase AC synchronous motor may be used instead.

It is a figure showing an air-conditioning system of a hybrid car in one embodiment of the present invention. It is a figure which shows the structure of the refrigerating-cycle apparatus in the above-mentioned embodiment. It is sectional drawing which shows the structure of the electric compressor of FIG. FIG. 3 is an electric circuit diagram of the drive device of FIG. 2. It is a figure which shows the action | operation of the electric compressor of FIG. It is a graph which shows the resistance value of a refrigerant | coolant and lubricating oil. It is a circuit diagram which shows the equivalent circuit by the side of the motor when a refrigerant | coolant stagnates in an electric compressor. 2 is a flowchart showing processing of a hybrid ECU, an air conditioner ECU, and an electric compressor drive device of FIG. 1. It is a timing chart which shows the action | operation of the inverter of FIG. It is a flowchart which shows the process of hybrid ECU in the modification of the above-mentioned embodiment.

Explanation of symbols

1 Hybrid ECU
DESCRIPTION OF SYMBOLS 1a Microcomputer 1b Memory 1c Insulation monitoring part 10 Motor 11 Housing 12 Rotating shaft 13 Rotor 14 Stator core 15 Stator coil 17 Terminal 20 Drive device 30 Compression mechanism 40 Inverter circuit 45 Capacitor 50 Control circuit 60 Temperature sensor 100 Electric compressor SW1 Switching element SW2 Switching Element SW3 Switching element SW4 Switching element SW5 Switching element SW6 Switching element 41 Negative side bus 42 Positive side bus 100 Electric compressor

Claims (12)

Switching based on a housing (11), a compression mechanism (30) disposed in the housing and compressing the refrigerant, a motor (10) disposed in the housing and driving the compression mechanism, and a voltage output from the battery Insulation resistance monitoring means (1c) for detecting the insulation resistance of the electric compressor having an inverter circuit (40) for outputting an alternating current to the stator coil (15) of the motor by operation;
Oil mixing determination means (S250) for determining whether lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant based on the detection value of the insulation resistance monitoring means ;
The insulation resistance monitoring means (1c) outputs an output signal to the inverter circuit (40), and detects the insulation resistance based on the attenuation amount of the output signal.
The inverter circuit (40) has a plurality of switching elements (SW1, SW2,... SW6) that output an alternating current to the stator coil (15) in accordance with switching.
First detection means (S200) for causing the insulation resistance monitoring means to detect a first detection value (R1) as the insulation resistance in a state where each of the plurality of switching elements is turned off;
Before the motor drives the compression mechanism, a switching element between the insulation resistance monitoring means and the stator coil (15) is turned on among the plurality of switching elements, and the insulation resistance monitoring means and the stator coil are turned on. (2) second detection means (S220) for detecting the second detection value (R2) as the insulation resistance by the insulation resistance monitoring means in a state in which the potential difference from (15) is eliminated;
Third detection means for detecting a third detection value (R3) as the insulation resistance by the insulation resistance monitoring means when the motor drives the compression mechanism and the stagnation of the refrigerant is eliminated in the housing. (S240)
The oil mixing determination means determines whether lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant based on the first, second, and third detection values. Lubricating oil determination device. The oil mixing determination means (S250)
A first absolute value (ΔR12) of a difference between the first detection value (R1) and the second detection value (R2) is not less than a first predetermined value (K1), and the third detection value. A second absolute value (ΔR32) of a difference between (R3) and the second detection value (R2) is equal to or greater than a second predetermined value (K2), and further, the third detection value (R3) and the second detection value (R3) When the third absolute value (ΔR31) of the difference from the detected value (R1) of 1 is within a predetermined range, it is determined that lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant. The lubricating oil determination device according to claim 1 , wherein: The inverter circuit (40) outputs the alternating current to the stator coil (15) with an output voltage of a power supply device as an input voltage,
An electrolytic capacitor (45) for stabilizing an output voltage output from the power supply device to the inverter circuit (40);
Before the motor drives the compression mechanism, the switching elements (SW4, SW5, SW6) between the insulation resistance monitoring means and the stator coil (15) among the plurality of switching elements are turned on and the insulation is performed. Charge / discharge control means (S320) for controlling the plurality of switching elements so as to charge / discharge the electrolytic capacitor in a state where the potential difference between the resistance monitoring means and the stator coil (15) is eliminated;
When the charge / discharge control unit controls the plurality of switching elements to charge / discharge the electrolytic capacitor in a state in which the potential difference between the insulation resistance monitoring unit and the stator coil (15) is eliminated, The lubricating oil determination device according to claim 2 , wherein the second detection means causes the insulation resistance monitoring means to detect the second detection value (R2). Temperature determining means (S300) for determining whether or not the temperature of the electrolytic capacitor is equal to or lower than a predetermined temperature;
When the temperature determination unit determines that the temperature of the electrolytic capacitor is equal to or lower than a predetermined temperature, the charge / discharge control unit eliminates the potential difference between the insulation resistance monitoring unit and the stator coil (15). The plurality of switching elements are controlled so that the electrolytic capacitor is charged and discharged, and the second detection means causes the insulation resistance monitoring means to detect the second detection value (R2). Item 4. The lubricating oil determination device according to Item 3 . A stagnation elimination determination means (S230) for judging whether or not the refrigerant stagnation is eliminated in the housing;
The third detection means causes the insulation resistance monitoring means to detect the third detection value (R3) when the stagnation elimination determination means determines that the stagnation of the refrigerant has been eliminated in the housing. The lubricating oil determination device according to any one of claims 1 to 4 . The lubricating oil according to claim 5 , wherein the stagnation elimination determination unit determines that the refrigerant stagnation has been eliminated in the housing when a variation in rotational torque of the motor falls within a predetermined range. Judgment device. The lubricating oil determination according to claim 5 , wherein the stagnation elimination determination unit determines that the refrigerant stagnation has been eliminated in the housing when the fluctuation of the angular velocity of the motor falls within a predetermined range. apparatus. The lubrication according to claim 5 , wherein the stagnation elimination determination unit determines that the stagnation of the refrigerant has been eliminated in the housing after a predetermined period or more has elapsed after starting the driving of the compression mechanism by the motor. Oil judgment device. The first, second, and third detection means respectively detect the insulation resistance by the insulation resistance monitoring means when a predetermined time elapses after the electric compressor is stopped. The lubricating oil determination device according to any one of 8 . The electric compressor constitutes a refrigeration cycle device for circulating the refrigerant,
The refrigeration cycle apparatus includes an outdoor heat exchanger (110) that cools a refrigerant discharged from the electric compressor with outdoor air, a decompressor (120) that decompresses the refrigerant cooled by the outdoor heat exchanger, and the decompression An indoor heat exchanger (130) for evaporating the refrigerant decompressed by the chamber with room air,
First temperature detecting means (200) for detecting the temperature of the outdoor air;
Second temperature detecting means (210) for detecting the temperature of the indoor air,
When the difference between the detected temperature of the first detecting means and the detected temperature of the indoor air is equal to or greater than a predetermined value, the first, second and third detecting means are lubricating oil determination apparatus according to any one of claims 1, wherein the resistance to be detected, respectively 9. After the third detection means detects the third detection value (R3) by the insulation resistance monitoring means, when the electric compressor is stopped and a predetermined period elapses, the first and second The detection means is adapted to detect the first and second detection values (R1, R2) by the insulation resistance monitoring means,
The oil mixing determination means determines whether lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant based on the first, second, and third detection values. The lubricating oil determination device according to any one of claims 1 to 9 . A memory (1b) for storing a self-diagnosis history;
Alarm means (1d) for issuing an alarm;
Insulation resistance determination means (S270) for determining whether the detected insulation resistance of the insulation resistance monitoring means is less than a certain value;
When the oil mixing determination means determines that lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant, and the detected insulation resistance of the insulation resistance monitoring means is less than a certain value, the insulation resistance determination means Is determined, alarm control means for controlling the alarm means (S280),
When the oil mixing determination means determines that lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant, and the detected insulation resistance of the insulation resistance monitoring means is a certain value or more, the insulation resistance determining means Storage control means (S260) for storing in the memory as the self-diagnosis history that lubricating oil other than the lubricating oil for the electric compressor is mixed in the refrigerant.
The lubricating oil determination device according to any one of claims 1 to 11 , further comprising:

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