JP4447390B2 - Cooling method for heat generating equipment for vehicles - Google Patents

Description

  The present invention relates to a cooling method for a vehicle heat generating device.

Some vehicles equipped with an electric motor such as a hybrid vehicle and the electric vehicle perform driving / regenerative operation of the electric motor, that is, transfer of electric power between the motor and a battery via a power drive unit (inverter). . This inverter is mainly composed of components such as semiconductors, and is known to generate heat when the electric motor is operated, that is, in an energized state. In the electric motor, further increase in output is required, and the amount of heat generated by the inverter tends to increase with the space occupied by the electric motor. Therefore, a cooling device is generally added to improve the cooling performance of the inverter. Yes.
However, when a dedicated cooling device is provided for the heat generating device such as the inverter as described above, it is necessary to arrange dedicated piping, a radiator, an electric water pump, etc., which is disadvantageous in terms of installation space and the number of parts. It becomes. Therefore, as a method of cooling the heat generating device, a cooling device dedicated to the heat generating device is not provided, but a door is provided in the vicinity of the outlet duct of the air conditioner to guide the conditioned air to the heat generating device and cool the heat generating device. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 08-40088

However, in the cooling device described above, the amount of air supplied to the passenger compartment is relatively reduced when trying to cool a heat-generating device such as an inverter. For this reason, there is a problem that the quietness is impaired when the operating rotational speed of the blower is increased in order to secure the air volume into the passenger compartment.
In addition, there is a method of increasing the size of the blower in order to ensure the air volume while maintaining silence, but there is a problem that the installation space and cost of the blower increase.

  Accordingly, the present invention provides a cooling method for a vehicle heat generating device that maintains quietness, reduces installation space and cost, and improves the cooling performance of the heat generating device without impairing the cooling performance in the passenger compartment. is there.

In order to solve the above-mentioned problems, the invention described in claim 1 supplies refrigerant by a compressor (for example, the hybrid compressor 17 in the embodiment) driven by at least an engine (for example, the engine E in the embodiment). The air-conditioning refrigeration cycle (for example, the refrigeration cycle 29 in the embodiment), the blower, and the heat generating device that generates heat when driving the driven means (for example, the motor M in the embodiment) (for example, the power in the embodiment) drive unit 4) the evaporator before Symbol air conditioning refrigeration cycle (for example, a cooling method using a contact cooling apparatus for a vehicle heating device provided in the evaporator 28) in the embodiment, the air volume switch (e.g., The air volume switch s2 in the embodiment is on and the air conditioning switch (for example, in the embodiment) If the temperature of the heat generating device exceeds the predetermined upper limit temperature when the adjustment switch s1) is off, the air conditioning refrigeration cycle is forcibly cooled. When the air volume switch is off, the temperature of the heat generating device is higher than the predetermined temperature. If it is determined that the heat generating device is cooled by a blower, and if the temperature of the heat generating device is not reduced only by the blower, the compressor is driven to cool the heat generating device by the air conditioning refrigeration cycle, and the air conditioning refrigeration cycle The cooling by is performed based on the driving efficiency of the compressor, and the cooling by the blower is performed based on the vehicle speed or the engine speed .

The invention described in claim 2 is characterized in that, when the heat generating device is cooled only by the blower, the air is introduced from the inside or outside of the vehicle compartment from the lower temperature side.
By comprising in this way, the cooling efficiency of introduction air can be improved.

According to the first aspect of the present invention, the cooling method is switched according to the heat generation state of the heat generating device, so that the heat generating device can be efficiently cooled and the burden on the heat generating device can be reduced. There is an effect that fuel efficiency can be improved while improving reliability.

Moreover , since the said heat-emitting device can be cooled irrespective of a passenger | crew's air-conditioning operation, there exists an effect which can reduce a passenger | crew's burden.

According to the invention described in claim 2 , since the cooling efficiency of the introduced air can be improved, there is an effect that the fuel consumption can be improved.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
In FIG. 1, reference numeral 1 denotes a hybrid vehicle. The hybrid vehicle 1 is provided with an engine E and a motor M that assists the driving force of the engine E. The engine E is of a so-called in-line 4-cylinder type, and at one end thereof, the motor M is provided between a transmission T, which is a transmission, and the engine E.
Here, the driving force of the engine E and the motor M is transmitted to the wheels W via the transmission T and the drive shaft 2. The motor M not only assists the driving force of the engine E but also performs a regenerative operation at the time of deceleration or the like.

The driving and regenerative operation of the motor M is performed by a power drive unit (PDU) 4 which is a heat generating device in response to a control command from a control unit (ECU) 3. The power drive unit 4 is connected to a high-voltage battery (BAT) 5 that exchanges electric energy with the motor M.
Furthermore, the hybrid vehicle 1 is equipped with a 12-volt auxiliary battery (12BAT) 6 for driving various auxiliary machines. The auxiliary battery 6 is connected to the battery 5 via a step-down converter (DV) 7 that is a DC / DC converter. Further, the auxiliary battery 6 is connected to the control device 3 via the power switch 8 of the control device 3. The control device 3 is connected with an air conditioning switch s1 and an air volume switch s2 of the air conditioning device.
Here, the step-down converter 7 steps down the voltage of the high-voltage battery 5 and charges the auxiliary battery 6. The control device 3 is connected to various sensors such as a vehicle speed sensor, an engine speed sensor, and a current sensor.

A transmission device 9 is provided at the other end of the engine E. The transmission device 9 is for linking an engine-driven compressor 10 (first compressor), which will be described later, with the engine E, and includes a pulley 12 provided on the engine E side via a rotary shaft 11, an engine The pulley 15 is provided on the side of the drive compressor 10 via a rotary shaft 13 and an electromagnetic clutch 14, and a belt 16 that interlocks the pulleys 12 and 15.
An actuator (not shown) that operates based on a control command from the control device 3 is connected to the electromagnetic clutch 14, and the actuator is operated to connect / disconnect the electromagnetic clutch 14.

  The engine-driven compressor 10 constitutes a part of a compressor unit (hereinafter referred to as a hybrid compressor) 17. The hybrid compressor 17 pumps the refrigerant vaporized in a so-called refrigeration cycle. In addition to the engine-driven compressor (EC) 10, the motor-driven compressor (MC) 18 (second second compressor) is used. Compressor). Specifically, the hybrid compressor 17 includes an engine-driven compressor 10 that is driven by the engine E and an electric motor DC in order to ensure the drive of an air conditioner or the like when the hybrid vehicle 1 is idling stopped (engine stopped). The compressor combines the motor-driven compressor 18 driven by the motor 19 and shares an input / output port. Therefore, the term “hybrid” is used in that either the engine E or the DC motor 19 can be driven.

  The motor-driven compressor 18 is connected to a DC motor (DCM) 19 as a drive source through a rotating shaft 20 and an electromagnetic clutch 21. Here, the electromagnetic clutch 21 is controlled to be connected and disconnected by the control device 3 in the same manner as the electromagnetic clutch 14 described above.

  The DC motor 19 is connected to the battery 5 via a compressor inverter (CINV) 22. The compressor inverter 22 is for driving the DC motor 19 and is connected to the control device 3. Then, temperature information from a temperature sensor (not shown) provided in the compressor inverter 22 and the power drive unit 4 is input to the control device 3. Here, the motor-driven compressor 18 can be driven and controlled by controlling the electric power supplied from the auxiliary battery 6 to the DC motor 19 by the compressor inverter 22.

  The hybrid compressor 17 is for pressure-feeding refrigerant to the pipe 23, and a condenser 25 is connected to the OUT side port 24a. The condenser 25 is used for so-called liquefaction to return the vaporized refrigerant to a liquid. A liquid receiver 26 is connected to the downstream side of the condenser 25, and an evaporator 28 is connected to the downstream side of the liquid receiver 26 via an expansion valve 27 that atomizes the refrigerant from the liquid. The IN side port 24 b of the hybrid compressor 17 is connected to the downstream side of the evaporator 28. The expansion valve 27 is arranged in the immediate vicinity of the evaporator 28 so that the atomized refrigerant is fed into the evaporator 28 without adhering to the refrigerant pipe.

The evaporator 28 evaporates the atomized refrigerant so as to remove the surrounding air or heat of the heat generating device, and is disposed in the introduction passage 30. That is, the hybrid compressor 17, the condenser 25, the liquid receiver 26, the expansion valve 27, and the evaporator 28 constitute a refrigeration cycle (air conditioning refrigeration cycle) 29 that is a heat exchanger.
A power drive unit 4 as a heat generating device is provided in close contact with the lower surface of the evaporator 28.

  On the upstream side of the evaporator 28 in the introduction passage 30, a blower (blower) 31 that receives a control command from the control device 3 and sends introduction air toward the evaporator 28 is disposed. On the downstream side of the evaporator 28, a heater core 32 that heats the introduced air cooled through the evaporator 28 by the heat of the engine E is disposed. Specifically, the introduction air sent by the blower 31 is cooled by being blown to the evaporator 28, and the cooled introduction air is temperature-adjusted by the heater core 32 and then is conditioned air into the vehicle interior. It will be sent.

  As shown in FIG. 2, an outside air inlet 33 for introducing air and an inside air inlet 34 are provided adjacent to the upstream side of the blower 31. A switching door 35 is slidable between the outside air introduction port 33 and the inside air introduction port 34 for switching between introduction of outside air (position indicated by a chain line in FIG. 2) or inside air circulation (position indicated by a solid line in FIG. 2). Is provided. An introduction passage 30 is provided from the outside air introduction port 33 and the inside air introduction port 34 to the vehicle interior via the switching door 35. The switching door 35 is controlled by the control device 3 so as to automatically introduce low-temperature introduced air based on detection results of an outside air temperature sensor and an inside air temperature sensor (not shown) connected to the control device 3. ing.

  In the introduction passage 30, the blower 31, the evaporator 28, and the heater core 32 are sequentially arranged toward the vehicle interior. In addition, an air mix damper 36 that blocks the introduced air cooled by the evaporator 28 is rotatably provided on the upstream side of the heater core 32. By rotating the air mix damper 36, the air volume of the introduced air blown to the heater core 32 is adjusted, and as a result, the temperature of the cooled introduced air is adjusted and supplied to the vehicle interior as conditioned air. It will be.

  An exhaust passage 37 for exhausting the introduced air is branched in the introduction passage 30. The exhaust passage 37 is disposed from the downstream side of the air mix damper 36 to the outside air introduction port 33, and the exhaust port 38 and the outside air introduction port 33 of the exhaust passage 37 are integrally formed. Further, an exhaust door (door) 39 that is operated by a control command from the control device 3 is provided at a branch point between the exhaust passage 37 and the introduction passage 30 so as to be freely opened and closed. By changing the opening degree of the exhaust door 39, the flow rate of the introduced air supplied to the introduction passage 30 and the exhaust passage 37 can be adjusted.

  Specifically, when the control device 3 closes the introduction passage 30 side, the exhaust passage 37 is opened (indicated by a chain line in FIG. 2), and even if the blower 31 is operated, Air-conditioned air is not sent. That is, even if the blower 31 is operated regardless of the occupant's intention, the occupant does not feel uncomfortable. Further, when the opening degree of the exhaust door 39 is adjusted and stopped at the intermediate operation position, the conditioned air is released to the exhaust passage 37 side even when the air volume requested by the occupant is small. The power drive unit 4 is cooled by the sufficient amount of introduced air while suppressing the air volume of the conditioned air supplied to the passenger compartment.

  The evaporator 28 shown in FIG. 3 is a so-called vertical type, and a plurality of heat radiation fins 40 are provided on the outer peripheral surface of the evaporator 28. A power drive unit 4 is provided in contact with the lower surface of the evaporator 28. Specifically, since the refrigerant once evaporated and cooled and liquefied at the lower part of the evaporator 28 is collected by gravity (indicated by a chain line in FIG. 3), a liquid pool is generated. This is a part with good cooling efficiency. Therefore, the heat of the power drive unit 4 can be efficiently removed by bringing the power drive unit 4 that generates heat into contact with the lower portion of the evaporator 28. The power drive unit 4 may be fixed by adhesion or welding in addition to contacting the evaporator 28.

  Next, FIG. 4 shows the upper limit value of the blower rotational speed with respect to the vehicle speed when the vertical axis represents the blower rotational speed and the horizontal axis represents the vehicle speed. The upper limit value of the blower rotation speed is set to about 1000 rpm when the vehicle speed is “0”. When the vehicle speed increases, the upper limit value is gradually increased and the vehicle speed becomes about 150 km / h (for example, about 125 ° C.). Even if the vehicle speed further increases, the upper limit value remains constant. That is, the area below the solid line in FIG. 4 is the blower operation permission area when the air volume switch s2 is off. The engine speed may be replaced with the vehicle speed on the horizontal axis. Further, the blower rotational speed on the vertical axis may be replaced with the duty (DUTY) of the blower control current.

  Next, the cooling control processing of the power drive unit will be described based on the flowcharts shown in FIGS. In the following description, the control device will be described as an ECU and the power drive unit will be described as a PDU for convenience.

First, in step S1, it is determined whether or not the PDU temperature T5 is higher than the PDU target temperature T4 (for example, about 105 ° C.). If the determination result is “YES” (high), the process proceeds to step S2, and if the determination result is “NO” (T4 or less), this process ends and the process returns.
Next, in step S2, it is determined whether or not the air volume switch is on. If the determination result is “YES” (on), the process proceeds to step S3. If the determination result is “NO” (off), the process proceeds to step S24 in FIG.

Next, in step S3, it is determined whether or not the exhaust door is closed. If the determination result is “YES” (closed), the process proceeds to step S4. If the determination result is “NO” (not closed), the process proceeds to step S10, and the exhaust door is closed and the process of step S3 is performed again. repeat.
In step S4, the blower is blown at the set level. In step S5, it is determined whether the air conditioning switch (A / C) is on. When the determination result is “YES” (on), the process proceeds to step S6, and when the determination result is “NO” (not on), the process proceeds to step S16 in FIG. In step S6, it is determined whether the indoor temperature T2 (for example, about 25 ± 5 ° C.) is lower than the indoor set temperature T1 (for example, about 25 ° C.). If the determination result is “YES” (low), the process proceeds to step S7, and if the determination result is “NO” (not low), the process proceeds to step S12 in FIG. Here, the indoor set temperature T1 is a temperature set when the air conditioning switch is on.

  Specifically, when the indoor temperature T2 is higher than the indoor set temperature T1, the amount of refrigerant supplied to the evaporator is increased, and the indoor temperature T2 and the temperature T5 of the power drive unit 4 are controlled to be reduced. When T2 is equal to or lower than the indoor set temperature T1, the process proceeds to cool the PDU by reducing the amount of refrigerant supplied to the evaporator.

  In step S7, an efficient driving method is performed by the control unit (ECU) from the vehicle state based on the efficiency map of the engine driven compressor shown in FIG. 11, the efficiency map of the motor driven compressor shown in FIG. 12, and signals from various sensors. Judgment is made, the hybrid compressor is driven or continuously driven, and the process proceeds to step S8.

  Here, FIG. 11 shows a map of engine-driven compressor efficiency (engine drive efficiency map) with respect to the magnitude of the load (vertical axis) and the rotational speed of the engine E (horizontal axis). In the efficiency map, the efficiency is improved in the upper left area, and the efficiency is decreased in the lower right area. That is, the efficiency is improved as the rotational speed is small and the load is large, and the efficiency is degraded as the rotational speed is large and the load is small. For the convenience of illustration, the illustration of the region where the load is larger than 1 is omitted (hereinafter the same applies to FIG. 12).

  FIG. 12 shows a map of the efficiency of the motor-driven compressor (drive efficiency map of the electric motor) with respect to the load size (vertical axis) and the rotational speed of the DC motor (horizontal axis). In FIG. 12, contrary to FIG. 11 described above, the efficiency is deteriorated in the upper left region, and the efficiency is improved in the lower right region. That is, the efficiency increases as the rotational speed increases and the load decreases, and the efficiency decreases as the rotational speed decreases and the load increases. Based on the efficiency maps shown in FIGS. 11 and 12, the control device appropriately selects a driving method of the hybrid compressor so as to obtain the best efficiency, and controls the electromagnetic clutch, the inverter for the compressor, and the like. Is output.

  In step S8, it is determined whether the PDU temperature T5 is decreasing. If the determination result is “YES” (decrease), the process proceeds to step S9. If the determination result is “NO” (not decreased), the process proceeds to step S11, and control is performed from the compressor efficiency map and the vehicle state. The apparatus determines an efficient method, increases the compressor rotation speed, and performs the process of step S8 again. In addition, although the temperature of the introduction air through an evaporator falls by performing the process of step S11, in order to prevent that indoor temperature T2 falls too much, the temperature of air-conditioning wind is adjusted with a heater core and an air mix damper. The

In step S9, it is determined whether or not the PDU temperature T5 is lower than a temperature 5 ° C. lower than the PDU target temperature T4. If the determination result is “YES” (low), the process is terminated and the process returns to the normal air conditioner control process. If the determination result is “NO” (T4−5 ° C. or higher), the process returns to step S7. Repeat the process.
The process of step S9 determines whether or not the PDU temperature T5 is sufficiently lowered with reference to a temperature 5 ° C. lower than the PDU target temperature T4 to prevent hunting. 4 is not limited to 5 ° C. (hereinafter, the same applies to step S18, step S17, and step S27).

  In step S12, as in step S7 described above, the control device determines an efficient driving method from the efficiency map of each compressor and the vehicle state, and the hybrid compressor is driven or continuously driven, and the process proceeds to step S13. In step S13, it is determined whether or not both the room temperature T2 and the PDU temperature T5 are reduced. If the determination result is “YES” (reducing), the process proceeds to step S14. If the determination result is “NO” (not decreasing), the process proceeds to step S15. The control device determines an efficient method from the compressor efficiency map and the vehicle state, increases the compressor rotation speed, and performs the process of step S13 again.

  In step S14, it is determined whether or not the PDU temperature T5 is lower than a temperature 5 ° C. lower than the PDU target temperature T4. If the determination result is “YES” (low), the process is terminated and the process returns to the normal process. If the determination result is “NO” (not low), the process returns to step S12 and the above-described process is repeated again.

  Next, in step S16, it is determined whether or not the PDU temperature T5 is decreasing. If the determination result is “YES” (reduced), the process proceeds to step S17, and if the determination result is “NO” (not decreased), the process proceeds to step S18. In step S17, it is determined whether or not the PDU temperature T5 is lower than a temperature 5 ° C. lower than the PDU target temperature T4. If the determination result is “YES” (low), the process is terminated and the process returns. If the determination result is “NO” (not low), the process returns to step S16 and the above-described process is repeated.

  In step S18, it is determined whether or not the PDU temperature T5 is higher than a temperature that is 10 ° C. lower than the upper limit temperature T3 of the PDU. If the determination result is “YES” (high), the process proceeds to step S19. If the determination result is “NO” (not high), the process returns to step S16 and the above-described processing is repeated. In step S18, the temperature is set to 10 ° C. lower than the upper limit temperature T3. However, the temperature is not limited to 10 ° C. as long as the temperature is sufficiently lower than the upper limit temperature T3 of the PDU (the same applies to step S30 below).

  In step S19 (air conditioning control means), the controller determines an efficient driving method from the efficiency map of each compressor and the vehicle state, and the hybrid compressor is driven or continuously driven, and the process proceeds to step S20. In step S20, it is determined whether or not the PDU temperature T5 is decreasing. If the determination result is “YES” (reducing), the process proceeds to step S21. If the determination result is “NO” (not decreasing), the process proceeds to step S23, and control is performed from the compressor efficiency map and the vehicle state. The apparatus determines an efficient method, increases the compressor rotation speed, and repeats the process of step S19 again.

  In step S21, it is determined whether or not the PDU temperature T5 is lower than a temperature 15 ° C. lower than the PDU upper limit temperature T3. If the determination result is “YES” (low), the process proceeds to step S22. If the determination result is “NO” (not low), the process returns to step S19 and the above-described processing is repeated. In step S22, the compressor is stopped and the process returns to step S16. Here, by performing the process of step S21 via the process of step S19 after the determination process of step S18, it can be determined that the PDU temperature T5 is reliably reduced by the process of step S19. In step S21, the temperature is set to 15 ° C. lower than the upper limit temperature T3. However, the temperature is not limited to 15 ° C. as long as the temperature is lower than the PDU temperature T5 (eg, T5 <T3-10 ° C.) in step S18. (The same applies to step S33).

  In step S24, it is determined whether or not the exhaust door is open. When the determination result is “YES” (open), the process proceeds to step S25, and when the determination result is “NO” (closed), the process proceeds to step S28 and the exhaust door is opened, and the process of step S24 is repeated. In step S24, the state where the exhaust door closes the introduction passage, that is, the state where the exhaust passage is open is set to “open”, and the state where the exhaust door opens the introduction passage, that is, the exhaust passage is closed. Is in the closed state.

  In step S25, the control device determines the vehicle speed, and the blower is driven and continuously driven. In step S26, it is determined whether the PDU temperature T5 is decreasing. If the determination result is “YES” (reducing), the process proceeds to step S27, and if the determination result is “NO” (not decreasing), the process proceeds to step S29. In step S27, it is determined whether or not the PDU temperature T5 is lower than a temperature 5 ° C. lower than the PDU target temperature T4. If the determination result is “YES” (low), the process ends and the process returns. If the determination result is “NO” (not low), the process returns to step S25 and the above-described processes are repeated.

In step S29, it is determined whether the blower rotation can be increased with respect to the vehicle speed. When the determination result is “YES” (can be increased), the process proceeds to step S35, and when the determination result is “NO” (cannot be increased), the process proceeds to step S30. In step S35, the rotation speed of the blower is increased, and the process returns to step S29 to repeat the above-described processing.
In step S30, it is determined whether or not the PDU temperature T5 is higher than a temperature that is 10 ° C. lower than the PDU upper limit temperature T3. If the determination result is “YES” (high), the process proceeds to step S31. If the determination result is “NO” (not high), the process returns to step S25 and the above-described processing is repeated.

In step S31 (air conditioning control means), the control device determines an efficient driving method from the efficiency map of each compressor and the vehicle state, and the hybrid compressor is driven or continuously driven, and the process proceeds to step S32. In step S32, it is determined whether the PDU temperature T5 is decreasing. If the determination result is “YES” (reduced), the process proceeds to step S33, and if the determination result is “NO” (not decreased), the process proceeds to step S36.
In step S36, the control device determines an efficient method from the compressor efficiency map and the vehicle state, increases the compressor rotation speed, and repeats the process of step S31 again.

  In step S33, it is determined whether or not the PDU temperature T5 is lower than a temperature 15 ° C. lower than the PDU upper limit temperature T3. If the determination result is “YES” (low), the process proceeds to step S34. If the determination result is “NO” (not low), the process returns to step S31 and the above-described processing is repeated. In step S34, the compressor is stopped and the process returns to step S25 to repeat the above-described processing.

  That is, when the occupant turns on the air conditioning switch s1 and the air volume switch s2, the conditioned air is sent into the vehicle interior while cooling the power drive unit 4 using the blower 31 and the refrigeration cycle 29, and the air conditioning. When the switch s1 is off and the air volume switch s2 is on, the power drive unit 4 is cooled only by the blower 31. When the air conditioning switch s1 is off and the air volume switch s2 is off, if the PDU temperature T5 is higher than the PDU target temperature T4, the conditioned air is sent into the vehicle interior by the exhaust door 39. The power drive unit 4 is cooled by the blower 31 in a state where the power is cut off. Further, an upper limit value of the blower rotational speed based on the engine rotational speed is set so as to suppress the operation sound of the blower 31 so that the occupant does not feel uncomfortable by operating the blower 31 even when the air volume switch s2 is off. Set. If the temperature of the power drive unit 4 does not decrease even when the rotational speed of the blower 31 is increased to the upper limit value, the hybrid compressor 17 is driven and the power drive unit 4 is cooled by the refrigeration cycle 29.

  Therefore, according to the first embodiment described above, the power drive unit 4 can be cooled without reducing the air volume of the conditioned air supplied through the introduction passage 30 into the vehicle interior. The power drive unit 4 can be cooled by the evaporator 28 and the blower 31 to improve fuel efficiency.

 In addition, since the supply of conditioned air to the passenger compartment can be blocked by the exhaust door 39, the hybrid compressor 17 and the blower 31 are operated regardless of the on / off operation of the air conditioning switch s1 and the air volume switch s2 by the passenger. Since the power drive unit 4 can be cooled without supplying conditioned air into the room, the burden on the power drive unit 4 can be reduced and the merchantability can be improved.

 Furthermore, since the refrigerant tends to accumulate in the lower portion of the evaporator 28, the power drive unit 4 can be efficiently cooled, and therefore, further improvement in fuel consumption can be achieved.

  Then, by setting the rotation speed of the blower 31 according to the vehicle speed and the engine rotation speed, the power drive unit 4 is cooled without causing the passenger to feel the operation sound of the blower 31 due to road noise or engine drive sound. Therefore, further improvement in merchantability can be achieved.

Furthermore, the cooling reaction time corresponding to the temperature of the power drive unit 4 can be shortened, and the width in which the temperature of the power drive unit 4 increases and decreases can be kept constant. Thus, the burden on the power drive unit 4 can be reduced.
Since the arrangement space can be reduced by sharing the outside air introduction port 33 and the exhaust port 38, the degree of freedom of arrangement of the outside air introduction port 33 and the discharge port 38 can be increased.

  Further, since the output of the engine-driven compressor 10 can be assisted by the motor-driven compressor 18 when the occupant steps on the accelerator, the power drive unit 4 can be cooled while the driving force of the engine E is sufficiently secured. Since this is possible, drivability can be improved.

  Further, the power drive unit 4 is efficiently cooled by gradually switching the cooling method from cooling by the blower 31 alone to cooling using the refrigeration cycle 29 in accordance with the heat generation state of the power drive unit 4. Therefore, fuel efficiency can be improved while improving the reliability of the power drive unit 4.

And since the cooling process of the said power drive unit 4 is performed by the said control apparatus 3 irrespective of operation of a passenger | crew's air conditioning switch s1 and the air volume switch s2, operation by a passenger | crew is unnecessary and it can reduce a passenger | crew's burden. it can.
Moreover, since the cooling efficiency can be improved by selecting and introducing air having a lower temperature, the fuel efficiency can be improved.

 Next, a second embodiment of the present invention will be described with reference to FIG. Since the second embodiment is obtained by changing the branch point between the exhaust passage 37 and the introduction passage 30 of the first embodiment described above, the same portions are denoted by the same reference numerals. The description of the compressor unit (hybrid compressor 17) described in the first embodiment is omitted.

 As shown in FIG. 13, a heater core 32 is arranged on the vehicle interior side of the introduction passage 30 as in the first embodiment described above. An air mix damper 36 is provided on the upstream side of the heater core 32. An exhaust passage 37 is branched from the side of the heater core 32, and an exhaust door 41 is provided at the branch point so as to be freely opened and closed. This exhaust door 41 adjusts the flow rate of the introduction air supplied from the blower 31 with the control command from the control device 3 in the introduction passage 30 and the exhaust passage 37, and the exhaust passage 37 is to be fully opened. In this case, the leading end of the exhaust door 41 is brought into contact with the heater core 32 and the supply of the introduced air to the heater core 32 is blocked by the air mix damper 36, so that the entire amount of the introduced air in the introduction passage 30 is exhausted. It will be led to the passage 37.

 As another aspect of the second embodiment, as shown in FIG. 14, a branch point of the exhaust passage 37 is provided on the upstream side of the heater core 32, and an exhaust door 42 is provided openably and closably here. As a result, the power drive unit 4 can be cooled without wastefully depriving the heat of the heater core 32. As a result, it is advantageous in that fuel efficiency can be further improved.

Therefore, according to the second embodiment described above, in particular, the exhaust door 41 can be reduced in size, so that there is an advantage that the manufacturing cost can be reduced and the vehicle weight can be reduced to improve the fuel consumption.
Further, since the heat of the heater core 32 is not wasted due to the cooling of the power drive unit 4, it is possible to improve the cooling efficiency and further improve the fuel consumption.

 The present invention is not limited to the above-described embodiment. For example, in addition to the vertical evaporator, an inclined evaporator shown in FIG. 15 and a horizontal evaporator shown in FIG. A portion where liquid pool is likely to occur may be provided in the lower part of the evaporator, and the power drive unit may be provided in contact with the lower surface. In addition to the hybrid compressor, an engine-driven compressor or a motor-driven compressor may be used alone. Further, in addition to the power drive unit, it may be used for a step-down converter and a compressor inverter. Furthermore, the present invention can be applied to other types of vehicles such as fuel cell vehicles other than hybrid vehicles.

1 is an overall configuration diagram of a first embodiment of the present invention. It is a partial block diagram of 1st Embodiment of this invention. It is a side view of the evaporator of 1st embodiment of this invention. It is a graph of the blower operation permission area | region of 1st Embodiment of this invention. It is a flowchart of the power drive unit cooling process of 1st Embodiment of this invention. It is a flowchart of the power drive unit cooling process of 1st Embodiment of this invention. It is a flowchart of the power drive unit cooling process of 1st Embodiment of this invention. It is a flowchart of the power drive unit cooling process of 1st Embodiment of this invention. It is a flowchart of the power drive unit cooling process of 1st Embodiment of this invention. It is a flowchart of the power drive unit cooling process of 1st Embodiment of this invention. It is an efficiency map of the engine drive compressor of 1st embodiment of this invention. It is an efficiency map of the motor drive compressor of 1st embodiment of this invention. It is a partial block diagram of 2nd Embodiment of this invention. It is a partial block diagram of the other form of 2nd embodiment of this invention. It is a side view equivalent to FIG. 2 of the other form of this invention. It is a side view equivalent to FIG. 3 of the other form of this invention.

Explanation of symbols

E Engine M Motor s1 Air conditioning switch s2 Airflow switch 4 Power drive unit (heat generating equipment)
10 Engine driven compressor (first compressor)
17 Hybrid compressor (second compressor)
18 Motor driven compressor 27 Expansion valve 28 Evaporator 29 Refrigeration cycle (refrigeration cycle for air conditioning)
30 Introduction passage 31 Blower (blower)
32 Heater core 33 Outside air introduction port 37 Exhaust passage 38 Exhaust port 39 Exhaust door (door)
S19, S31 Air conditioning control means

Claims (2)

Heat generation for a vehicle provided with an air-conditioning refrigeration cycle and a blower for supplying refrigerant at least by a compressor driven by an engine, and a heat-generating device that generates heat when the driven means is driven in contact with an evaporator of the air-conditioning refrigeration cycle It is a cooling method using a device cooling device,
When the air flow switch is on and the air conditioning switch is off, if the temperature of the heat generating device exceeds a predetermined upper limit temperature, the air conditioning switch is forcibly cooled by the refrigeration cycle for air conditioning, and when the air flow switch is off, the temperature of the heat generating device is the predetermined temperature. If it is determined that the temperature is higher than the temperature, the heat generating device is cooled by a blower, and if the temperature of the heat generating device is not reduced only by the blower, the compressor is driven to cool the heat generating device by an air conditioning refrigeration cycle,
The cooling by the air-conditioning refrigeration cycle is performed based on the driving efficiency of the compressor, and the cooling by the blower is performed based on the vehicle speed or the engine rotational speed .   Inside and outside the vehicle compartment when cooling the heat-generating equipment with only the blower. The method for cooling a vehicle heat-generating device according to claim 1, wherein air is introduced from a lower temperature.

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