JP2013248901A - Vehicle air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prolong idle stop.SOLUTION: When idle stop is not in operation, an air conditioner ECU 5 calculates normal control TEO as target evaporator temperature TEO, and turns ON/OFF a compressor 1 so that an evaporator blow-out temperature Te comes close to the normal control TEO. When the idle stop is started, the air conditioner ECU 5 calculates reduction control TEO as the target evaporator temperature TEO, and ON/OFF-controls the compressor 1 so that the evaporator blow-out temperature Te comes close to the reduction control TEO until the next idle stop is started.

Description

  The present invention relates to a vehicle air conditioner applied to a vehicle that stops a traveling engine while the vehicle is stopped.

  In a vehicle (for example, a hybrid vehicle or an idle stop vehicle) that functions as an idle stop that stops the traveling engine while the vehicle is stopped, the traveling engine is stopped when the air conditioning compressor is driven using the traveling engine as a power source. At the same time, the air conditioning compressor also stops. For this reason, when idle stop is carried out, the temperature of the evaporator rises. Therefore, in summer, the temperature of the conditioned air blown into the passenger compartment rises, so that the comfort in the passenger compartment is deteriorated and the anti-fogging property is deteriorated.

  In the prior art described in Patent Document 1 for solving this problem, when the traveling engine is determined to be before stopping (that is, before the vehicle is stopped), the target evaporator temperature (that is, the evaporator) calculated from the thermal load in the passenger compartment. The air conditioning compressor is controlled so that the temperature of the evaporator is lower than the target value of the temperature. As a result, it is possible to delay the rise in the temperature of the evaporator after the idling stop is performed, and it is possible to extend the period during which the idling stop is performed without deteriorating comfort and anti-fogging properties in the passenger compartment. .

JP 2000-16071 A

  In the above-mentioned Patent Document 1, when it is determined that the traveling engine is not stopped, the rise in the evaporator temperature can be delayed by controlling the air conditioning compressor so as to lower the evaporator temperature below the target evaporator temperature. However, the time from when the traveling engine is determined to be before stopping until the traveling engine is actually stopped is very short. For example, if it is determined that the driving engine is not stopped when the brake is started, it takes about 5 to 15 seconds from the start of braking until the vehicle stops. During this period, the temperature of the evaporator is reduced to lower the evaporator temperature. Even if the compressor is controlled, there is a problem that the temperature of the evaporator (that is, the cooling heat exchanger) is not sufficiently lowered before the engine is stopped, and the effect of extending the idle stop time is small.

  An object of the present invention is to provide a vehicle air conditioner that makes it possible to sufficiently extend the idle stop time.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a vehicle air conditioner that is applied to a vehicle having an idle stop function of stopping the travel engine (4) when the vehicle is stopped.
A compressor (1) which constitutes a refrigeration cycle apparatus (R) and compresses a refrigerant by kinetic energy output from the traveling engine;
A cooling heat exchanger (9) for constituting the refrigeration cycle apparatus and cooling air with the refrigerant;
An air outlet (51, 53, 55) for blowing the conditioned air that has passed through the cooling heat exchanger into the passenger compartment;
Temperature detection means (32) for detecting the temperature of the cooling heat exchanger;
Control means (S7, S9, S20 to S26, S26a, S25a, S24c) for controlling the compressor so that the temperature detected by the temperature detection means approaches the target temperature;
Calculation means (S25) for calculating a first target temperature as the target temperature based on a thermal load in the vehicle interior;
When the idle stop is not performed, the control unit sets the target temperature to the first target temperature, and when the idle stop is performed, the control unit performs the next idle stop. The target temperature is set to a second target temperature that is equal to or lower than the first target temperature.

  In the first aspect of the present invention, when the idling stop is performed once, the target temperature is set to the second target temperature until the next idling stop is performed. Therefore, the idling stop is performed once. Then, the temperature of the evaporator can be sufficiently lowered before the next idle stop is performed. For this reason, the temperature which blows off from a blower outlet to a vehicle interior can fully be lowered | hung. Therefore, the time for performing the idle stop can be sufficiently extended.

  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.

It is a figure which shows the structure of the vehicle air conditioner in 1st Embodiment of this invention. It is a flowchart which shows the control processing of the air-conditioner ECU in the said 1st Embodiment. It is a flowchart which shows the control processing of the air-conditioner ECU in the said 1st Embodiment. It is a figure for demonstrating the control processing of the air-conditioner ECU of FIG. It is a figure for demonstrating the control processing of the air-conditioner ECU of FIG. It is a flowchart which shows the control processing of the air-conditioner ECU in 2nd Embodiment of this invention. It is a flowchart which shows the control processing of the air-conditioner ECU in 3rd Embodiment of this invention. It is a figure which shows the relationship between the idle stop implementation time in 3rd Embodiment, and the fall width | variety of the fall control TEO. It is a flowchart which shows the control processing of the air-conditioner ECU in 4th Embodiment of this invention. It is a figure for demonstrating the action | operation in 4th Embodiment. It is a flowchart which shows the control processing of the air-conditioner ECU in 5th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are given the same reference numerals in the drawings in order to simplify the description.

(First embodiment)
A vehicle air conditioner according to a first embodiment of the present invention will be described below with reference to FIG.

  The refrigeration cycle apparatus R of the vehicle air conditioner shown in FIG. 1 is provided with a compressor 1 that sucks, compresses, and discharges refrigerant by kinetic energy output from the traveling engine 4. Specifically, the compressor 1 has an electromagnetic clutch 2, and kinetic energy (power) output from the traveling engine 4 is transmitted to the compressor 1 via the electromagnetic clutch 2 and the belt 3. Energization of the electromagnetic clutch 2 is intermittently performed by an electronic control unit (hereinafter referred to as an air conditioner ECU 5), and the operation of the compressor 1 is intermittently performed by energization of the electromagnetic clutch 2.

  As the compressor 1, a fixed displacement compressor having a constant refrigerant discharge capacity is used. Then, the high-temperature and high-pressure superheated gas refrigerant discharged from the compressor 1 flows into the condenser 6, where the refrigerant is cooled and condensed by exchanging heat with outside air blown from a cooling fan (not shown). The refrigerant condensed in the condenser 6 then flows into the liquid receiver 7, where the gas-liquid refrigerant is separated inside the liquid receiver 7, and surplus refrigerant (liquid refrigerant) in the vapor compression refrigeration cycle apparatus R is obtained. It is stored in the liquid receiver 7.

  The liquid refrigerant from the liquid receiver 7 is depressurized to a low pressure by an expansion valve (decompressor) 8 and becomes a low-temperature low-pressure gas-liquid two-phase state. The expansion valve 8 is a temperature type expansion valve having a temperature sensing part 8a that senses the temperature of the outlet refrigerant of the evaporator 9. The low-temperature and low-pressure refrigerant from the expansion valve 8 flows into the evaporator (cooling heat exchanger) 9. The evaporator 9 is installed in the air conditioning case 10 of the vehicle air conditioner, and the low-temperature and low-pressure refrigerant flowing into the evaporator 9 absorbs heat from the air in the air-conditioning case 10 and evaporates. The outlet of the evaporator 9 is coupled to the suction side of the compressor 1 and constitutes a closed circuit with the above-described cycle components.

  In the air conditioning case 10, a blower 11 is disposed on the upstream side of the evaporator 9, and the blower 11 is provided with a centrifugal blower fan 12 and a blower drive motor 13. An inside / outside air switching box 14 is disposed on the suction side of the blower fan 12, and the inside / outside air switching door 14 a in the inside / outside air switching box 14 opens and closes the outside air introduction port 14 b and the inside air introduction port 14 c. Thereby, outside air (vehicle compartment outside air) or inside air (vehicle compartment air) is switched and introduced into the inside / outside air switching box 14. The inside air inlet 14c is opened downward on the passenger seat side in the vicinity of the vehicle interior instrument panel 100. The inside / outside air switching door 14a is driven by a servo motor 14e.

  Among the air conditioners for vehicles, the air conditioning unit 15 part arranged on the downstream side of the blower 11 is arranged at the center position in the vehicle width direction inside the instrument panel in the front part of the vehicle interior. Offset on the passenger side. An air mix door 19 is disposed in the air conditioning case 10 on the downstream side of the evaporator 9. On the downstream side of the air mix door 19, a hot water heater core (heating heat exchanger) 20 that heats the inside air (or outside air) using cooling water (hot water) of the traveling engine 4 as a heat source is installed. A hot water pipe H that circulates cooling water using a pump 20a is provided between the traveling engine 4 and the hot water heater core 20.

  A bypass passage 21 that bypasses the hot water heater core 20 and flows air is formed on the side (upper part in the drawing) of the hot water heater core 20 of the present embodiment. The air mix door 19 is a rotatable plate-like door and is driven by a servo motor 22. The air mix door 19 adjusts the air volume ratio between the hot air passing through the hot water heater core 20 and the cool air passing through the bypass passage 21, and the air blown into the vehicle interior by adjusting the air volume ratio of the cold / hot air. Adjust the temperature.

  Hot air from the hot water heater core 20 and cold air from the bypass passage 21 are mixed in the air mixing unit 17 to produce conditioned air at a desired temperature. Further, in the air conditioning case 10, on the downstream side of the air mixing unit 17, blowout openings 42, 43, 44 are provided to blow the conditioned air created in the air conditioning case 10 into the vehicle interior that is the air conditioning target space. Is provided. As the blowing openings 42, 43, 44, a defroster opening 42, a face opening 43, and a foot opening 44 are provided. The blowout openings 42, 43, 44 are opened and closed by opening / closing mechanisms 46, 47, 48. The opening / closing mechanisms 46, 47, and 48 are rotationally driven by a servo motor 70 via a link mechanism.

  The opening / closing mechanism 48 is a defroster door that opens and closes the blowing opening 42. The opening / closing mechanism 46 is a face door that opens and closes the face opening 43. The opening / closing mechanism 47 is a face door that opens and closes the foot opening 44.

  A defroster duct 50 is connected to the defroster opening 42, and conditioned air is blown from the defroster outlet 51 at the tip of the defroster duct 50 toward the inner surface of the vehicle front window glass.

  A face duct 52 is connected to the face opening 43, and conditioned air is blown out from the face outlet 53 at the tip of the face duct 52 toward the upper body of the occupant.

  A foot duct 54 is connected to the foot opening 44 so that conditioned air is blown from the foot outlet 55 at the tip of the foot duct toward the feet of the occupant.

  Next, an outline of the electric control unit in the present embodiment will be described.

  The air conditioner ECU 5 shown in FIG. 1 is an electronic control unit that includes a known microcomputer including a CPU, a ROM, a RAM, and the like, and peripheral circuits thereof. The air conditioner ECU 5 performs an air conditioning control process as the computer program is executed. The air conditioner ECU 5 performs the air conditioning control process, based on the detection signals of the sensors 32 to 36, the output signals of the switches 37a to 37e, and the output signal of the engine ECU 80, and the electromagnetic clutch 2, the servo motors 14e, 22, and 70. , And the blower drive motor 13 are controlled.

  The sensor 32 is disposed at a site on the downstream side of the air flow of the evaporator 9 and detects an air temperature blown out from the evaporator 9 (hereinafter referred to as an evaporator blowout temperature Te). The sensor 33 detects the temperature of the air in the vehicle interior (hereinafter referred to as the vehicle interior temperature Tr). The sensor 34 detects the temperature of the air outside the passenger compartment (hereinafter referred to as the outside air temperature Tam). The sensor 35 detects the amount of solar radiation Ts in the passenger compartment. The sensor 36 detects the temperature Tw of the cooling water of the traveling engine 4.

  The operation switch 37a is a setting switch for setting the set temperature Tset. The operation switch 37b is a setting switch for setting the air volume. The operation switch 37c is a switch for setting the blowing mode. The operation switch 37d is a switch for operating / stopping the compressor 1. The operation switches 37 a to 37 d are provided on the air conditioning control panel 37.

  The engine ECU 80 is an electronic control device for controlling the traveling engine 4. The engine ECU 80 of the present embodiment causes the traveling engine 4 to perform idle stop, and when the traveling engine 4 is subjected to idle stop, the traveling engine 4 is stopped by the idle stop. Is output to the air conditioner ECU 5. The idle stop is to stop the traveling engine 4 when the vehicle is temporarily stopped due to, for example, traffic jam or waiting for a signal.

  Next, the operation of this embodiment in the above configuration will be described. The air conditioner ECU 5 executes main control processing according to the computer program. FIG. 2 is a flowchart showing the main control process. The execution of the main control process is started when the ignition switch of the traveling engine 4 is turned on.

  First, in step S1, flags and timers are initialized, and in the next step S2, operation signals of the operation switches 37a to 37f of the air conditioning control panel 37 are read. In the next step S3, a vehicle environmental state signal, that is, a detection signal from the sensors 32-36, 38, 39a, 39b, 39c, etc. is read.

  Subsequently, in step S4, a target blowing temperature TAO of the conditioned air blown into the vehicle interior is calculated. This target blowing temperature TAO is a blowing temperature required for maintaining the passenger compartment at the set temperature Tset of the temperature setting switch 37a, and is calculated based on the following Equation 1.

TAO = Kset × Tset−Kr × Tr
−Kam × Tam−Ks × Ts + C (Equation 1)
However, Tr: Vehicle interior temperature detected by the inside air sensor 33 Tam: Outside air temperature detected by the outside air sensor 34 Ts: Solar radiation amount detected by the solar radiation sensor 35 Kset, Kr, Kam, Ks: Control gain C: For correction Next, in step S5, the target air blowing amount B of the air blown by the blower 11, specifically, the blower voltage Ve that is the applied voltage of the blower driving motor 13 is determined based on the target blowing temperature TAO. The method for determining the blower voltage Ve is well known. The blower voltage (target air volume) Ve is increased on the high temperature side (maximum heating side) and the low temperature side (maximum cooling side) of the target blowing temperature TAO, and the target blowing temperature TAO is intermediate. Reduce the blower voltage (target air volume) Ve in the temperature range.

  Next, in step S6, the inside / outside air mode is determined. For example, as the target blowing temperature TAO increases from the low temperature side to the high temperature side, the setting may be switched from the all-inside air mode → the inside / outside air mixing mode → the all outside air mode.

  Next, in step S7, a target evaporator temperature TEO is calculated by a sub-control process described later, and the electromagnetic clutch 2 is turned on / off based on the calculated target evaporator temperature TEO and the evaporator outlet temperature Te. decide.

  Next, in step S8, the target opening degree SW of the air mix door 19 is calculated by the following formula 2 based on the target outlet temperature TAO, the evaporator outlet temperature Te, and the hot water temperature Tw.

SW = [(TAO−Te) / (Tw−Te)] × 100 (%) (Equation 2)
Here, the target opening degree SW of the air mix door 19 sets the maximum cooling position of the air mix door 19 (solid line position in FIG. 1) to 0%, and the maximum heating position of the air mix door 19 (dotted line position in FIG. 1). Is expressed as a percentage with 100%.

  Next, it progresses to step S9 and a control signal is output to various actuator parts (2, 13, 14e, 22, 70) so that the control state determined by said step S5-S8 may be obtained. When it is determined in the next step S10 that the control cycle τ has elapsed, the process returns to step S2.

  Next, sub-control processing for calculating the target evaporator temperature TEO in the present embodiment will be described. FIG. 3 is a flowchart showing the sub-control processing.

  First, in step S20, the set temperature Tset set by the operation switch 37a is read. Next, in step S21, the outside air temperature Tam detected by the sensor 34 is read. Next, in step S22, the amount of solar radiation Ts in the passenger compartment detected by the sensor 35 is read. Next, in step S23, the vehicle interior temperature Tr detected by the sensor 33 is read. In the next step S24, it is determined based on the output signal of the engine ECU 80 whether or not idling has been stopped. At this time, when the idling stop is not performed, it is determined as NO, the process proceeds to step S25, and a target value (hereinafter referred to as normal value) for performing the normal control based on the target blowing temperature TAO calculated in step S4. (Referred to as control TEO) is calculated as the target evaporator temperature TEO.

  In FIG. 4, the horizontal axis represents the target blowing temperature TAO, the vertical axis represents the target evaporator temperature TEO, and the graph a shows the relationship between the target blowing temperature TAO and the normal control TEO.

  When the target blowing temperature TAO is in the intermediate temperature range, the normal control TEO has the highest value. When the target blowing temperature TAO is lower than the intermediate temperature range, the normal control TEO has the lowest value, and the target blowing temperature TAO has the intermediate temperature range. Is higher than the normal control TEO.

  Based on the graph a and the target outlet temperature TAO calculated in step S4, the normal control TEO is calculated.

  Further, in step S24, when the idling stop is performed, it is determined as YES, the process proceeds to the next step S26, and the target evaporator temperature TEO is determined based on the target outlet temperature TAO calculated in step S4. A target value (hereinafter referred to as a decrease control TEO) for performing the TEO decrease control is calculated. The lowering control TEO is set to a temperature lower than the lowest value of the normal control TEO by a predetermined value (= the lowest value of the normal control TEO−the predetermined value).

  Steps S7, S9, and S20 to S26 correspond to the control means according to the claims. Step S25 corresponds to calculation means according to the claims.

  Next, specific control processing of the air conditioner ECU 5 of the present embodiment will be described.

  First, when the idle stop is not performed, the normal control TEO is calculated as the target evaporator temperature TEO (step S25). Accordingly, the electromagnetic clutch 2 is ON / OFF controlled based on the evaporator outlet temperature Te and the normal control TEO (steps S7 and S9). At this time, when the evaporator outlet temperature Te is equal to or lower than (normal control TEO-ΔT), the electromagnetic clutch 2 is turned off to turn off the compressor 1. On the other hand, when the evaporator outlet temperature Te is higher than (normal control TEO + ΔT), the electromagnetic clutch 2 is turned on to turn on the compressor 1. As a result, the evaporator outlet temperature Te approaches the normal control TEO.

  Here, ΔT is a temperature set for giving hysteresis characteristics to the ON / OFF control of the electromagnetic clutch 2.

  Thereafter, when the idle stop is performed, a decrease control TEO is calculated as the target evaporator temperature TEO (step S26). Accordingly, the electromagnetic clutch 2 is ON / OFF controlled based on the evaporator outlet temperature Te and the decrease control TEO (steps S7 and S9). Accordingly, the compressor 1 is turned off by turning off the electromagnetic clutch 2 when the evaporator blowout temperature Te is equal to or lower than (decrease control TEO-ΔT). On the other hand, when the evaporator outlet temperature Te is higher than (decrease control TEO + ΔT), the compressor 1 is turned on by turning on the electromagnetic clutch 2. As a result, the evaporator outlet temperature Te approaches the decrease control TEO.

  According to the present embodiment described above, the air conditioner ECU 5 calculates the normal control TEO as the target evaporator temperature TEO when the idling stop is not performed, and the compressor so that the evaporator outlet temperature Te approaches the normal control TEO. 1 is turned ON / OFF. Thereafter, when the idle stop is performed, the air conditioner ECU 5 calculates the decrease control TEO as the target evaporator temperature TEO, and brings the evaporator outlet temperature Te close to the decrease control TEO until the next idle stop is performed. Thus, the compressor 1 is ON / OFF controlled.

  In the prior art, when the traveling engine 4 is determined to be before stopping, the target evaporator temperature TEO is decreased, but the time from when the traveling engine 4 is determined to be before stopping until the traveling engine is actually stopped. Tw is very short. For this reason, the temperature of the evaporator 9 is not sufficiently lowered before the traveling engine 4 is stopped, and it is impossible to perform idling stop for a long period of time (see FIGS. 5A to 5D).

  On the other hand, in the present embodiment, when the idle stop is performed, the air conditioner ECU 5 causes the electromagnetic clutch 2 to approach the evaporator blowout temperature Te to the decrease control TEO until the next idle stop is performed. The compressor 1 is controlled to be turned on / off. For this reason, it is possible to lengthen the period during which the electromagnetic clutch 2 is turned on / off so that the evaporator outlet temperature Te approaches the decrease control TEO. Therefore, the evaporator outlet temperature Te can be sufficiently reduced. Therefore, it is possible to prolong the idle stop (see FIGS. 5E to 5H).

(Second Embodiment)
In the first embodiment, the example in which it is determined in step S24 whether or not the idling stop has been performed has been described. Instead, in the present embodiment, the idling stop is performed during a certain period in step S24. An example of determining whether or not has been performed will be described.

  FIG. 6 is a flowchart showing the sub control processing by the air conditioner ECU 5 of the present embodiment.

  In the present embodiment, once the idle stop is performed, each process of steps S20, S21, S22, and S23, and the YES determination process in step S24, even if the state in which the idle stop is not performed is continued thereafter. And the calculation process of the reduction | decrease control TEO in step S26 is each repeated. For this reason, once the idling stop is performed, the calculation of the decrease control TEO (second target temperature) is repeated.

  After that, if the idle stop is performed as described above and the state where the idle stop is not performed for a certain period or more after the determination of YES is made in step S24, the idle stop is not performed within the certain period in step S24. Determine NO. Accordingly, the process proceeds to step S25, and the normal control TEO is calculated.

  According to the present embodiment described above, even if the idle stop is performed once and the decrease control TEO is calculated as the target evaporator temperature TEO, if the idle stop is not stopped for a certain period thereafter, the target evaporation is performed. The normal control TEO (first target temperature) is calculated as the vessel temperature TEO. Therefore, once the idling stop is performed, the evaporator outlet temperature Te decreases. However, if the state where the idling stop is not performed for a certain period thereafter continues, the evaporator outlet temperature Te can be increased.

(Third embodiment)
In the first embodiment described above, the example in which the decrease control TEO is set to a temperature lower than the minimum value of the normal control TEO by a predetermined value has been described. Instead, in the present embodiment, the decrease control TEO is changed. An example to be performed will be described.

  FIG. 7 shows a flowchart showing sub-control processing by the air conditioner ECU 5 of the present embodiment. In FIG. 7, steps having the same reference numerals as those in FIG. 3 indicate the same steps.

  In the present embodiment, once an idle stop is performed and YES is determined in step S24, an idle stop execution period estimated to be performed next is estimated in the next step S26a.

  Specifically, once the idle stop is performed as described above, the time during which the engine is stopped by the implemented idle stop (hereinafter referred to as the engine stop time) is measured. The measured engine stop time is estimated as an idle stop execution period that is expected to be executed next.

  Next, in step S26, the reduction control TEO is calculated using the estimated idle stop execution period and the normal control TEO.

  Specifically, a value obtained by subtracting the decrease width ΔW from the normal control TEO (= normal control TEO−reduction width ΔW) is set as the decrease control TEO. FIG. 8 shows the relationship between the reduction width ΔW and the idle stop period.

  The longer the idle stop period, the greater the reduction width ΔW. Therefore, the lowering TEO decreases as the idle stop execution period becomes longer. In this way, the decrease control TEO can be obtained based on the idle stop execution period.

  According to the present embodiment described above, once an idle stop is performed, it is estimated as an idle stop execution period that is expected to be performed next, and the estimated idle stop execution period becomes longer. The lowering width ΔW is increased. As a result, the lowering TEO can be lowered as the idle stop execution period expected to be executed next becomes longer. For this reason, the evaporator blowing temperature Te can be lowered in preparation for an idle stop that is expected to be performed next. On the other hand, when the execution time of the idle stop that is expected to be performed next is short, the reduction width ΔW can be reduced, so that energy loss during vehicle travel can be suppressed.

  In the third embodiment, the example in which the reduction width ΔW is obtained according to the idle stop execution period has been described. Instead of this, as shown in the following (a) and (b), the traffic jam information, the waiting time of the traffic light The reduction width ΔW may be obtained based on road traffic information such as

  (A) When the traffic jam information in the traveling direction of the vehicle is acquired from the road unit by the road-to-vehicle communication device, the decrease width ΔW is increased as the traffic distance of the vehicle in the traveling direction of the vehicle is longer. In other words, it is determined that the longer the congestion distance, the longer the idle stop execution period expected to be executed next. As a result, the longer the congestion distance of the vehicle, the lower the decrease control TEO.

  (B) When the standing time of the traffic signal at the intersection in the vehicle traveling direction (that is, the red signal display period) is acquired from the road device by the road-to-vehicle communication device, the lowering width ΔW is increased as the standing time of the traffic light is longer. In other words, it is determined that the longer the standing time of the traffic light, the longer the idle stop execution period expected to be executed next. As a result, the lower the TEO for decrease control, the lower the standing time of the traffic light.

  In addition, instead of road traffic information such as traffic jam information and traffic signal waiting time, the reduction width ΔW may be obtained based on vehicle position information and vehicle operation status.

  In the fourth embodiment, the example in which the reduction width ΔW is obtained according to the idle stop execution period has been described, but instead, as in the following (c), (d), (e), and (f) The lowering width ΔW may be increased as the thermal load in the passenger compartment increases.

  (C) When the target blowing temperature TAO is used as a parameter indicating the heat load in the passenger compartment, the lowering width ΔW is increased as the target blowing temperature TAO is lower.

  (D) The lowering width ΔW is increased as the passenger compartment temperature detected by the interior air sensor 33 increases.

  (E) The lowering width ΔW is increased as the outside air temperature detected by the outside air sensor 34 increases.

  (F) The decrease width ΔW is increased as the amount of solar radiation detected by the solar radiation sensor 35 increases.

(Fourth embodiment)
In the present embodiment, an example will be described in which when idling stop is performed and YES is determined in step S24, the decrease control TEO is calculated in step 26 and the target air flow rate is calculated.

  FIG. 9 shows a flowchart showing sub-control processing by the air conditioner ECU 5 of the present embodiment. In FIG. 9, steps having the same reference numerals as those in FIG. 3 indicate the same steps.

  In the present embodiment, when the reduction control TEO is calculated in step S26, in the next step 27, the target air blowing amount Ba is calculated based on the reduction control TEO.

  The target air volume Ba is an air volume that is a predetermined amount ΔB lower than the target air volume B obtained based on the target blowing temperature TAO in step S5 of FIG. 2 (= target air volume B−predetermined amount ΔB). The predetermined amount ΔB is set so as to increase as the decrease control TEO decreases. Thereby, the target air volume Ba can be reduced as the decrease control TEO decreases.

For example, when a blower amount of 150 m ³ / h is generated by the blower 11 (see FIG. 10A), the idle stop is performed, YES is determined in step S24, and the reduction control is performed in step 26. When TEO is calculated and the target evaporator temperature TEO is lowered from, for example, 10 degrees to 1 degree, the temperature of the air blown out from the evaporator 9 is lowered. For this reason, the temperature of the air-conditioning wind which a passenger | crew senses falls.

Therefore, in the present embodiment, the target air blowing amount Ba can be reduced as the decrease control TEO decreases. For this reason, even if idling stop is performed and instead of the normal control TEO, the decrease control TEO is calculated and the temperature of the air blown out from the evaporator 9 decreases, the amount of air blown by the blower 11 is reduced to 150 m ^3. When the speed is lowered from / h to 100 m ³ / h (see FIG. 10C), it is possible to suppress a decrease in the temperature of the conditioned air experienced by the passenger.

  However, when the target air volume Ba calculated in step 27 is smaller than the minimum air volume Min that can be blown by the blower 11 (target air volume Ba <minimum air volume Min), the actual target air volume of the air blower 11 is set to the minimum air volume. Set to Min. The opening degree of the air mix door 19 is corrected according to the difference ΔH between the target air flow rate Ba and the minimum air flow rate Min.

  Specifically, the opening degree of the air mix door 19 is corrected so as to increase the warm air passing through the hot water heater core 20 and decrease the cool air passing through the bypass passage 21 as the difference ΔH increases. That is, the heating amount (reheat amount) of air by the hot water heater core 20 is increased. Thereby, even if the target air volume Ba calculated | required in the said step 27 is smaller than the minimum air volume Min which can blow with the air blower 11, it can suppress that the temperature of the air conditioned wind which a passenger | crew senses falls.

  As described above, even when the idling stop is performed and the decrease control TEO is calculated instead of the normal control TEO, it is possible to suppress a change in the comfort experienced by the occupant.

(Fifth embodiment)
In the present embodiment, an example will be described in which the normal control TEO is calculated even when the idling stop is performed when the automobile is located on the expressway.

  In the present embodiment, a GPS receiver for acquiring vehicle position information and a navigation ECU for storing map information are used to calculate the normal control TEO and the decrease control TEO.

  FIG. 11 is a flowchart showing a sub control process by the air conditioner ECU 5 of the present embodiment. In FIG. 11, steps having the same reference numerals as those in FIG. 3 indicate the same steps.

In the present embodiment, after the processing of steps S20 to S23, the position information of the vehicle is acquired by the GPS receiver in step S24b. Along with this,
Based on the acquired position information of the vehicle and map information stored in advance in the navigation ECU, it is determined whether or not the vehicle is located in the expressway (step S24c). At this time, when the navigation ECU determines that the vehicle is located not on the expressway but on a general road, it determines NO in step S24c. In this case, each process of step S24 and step S25 (or step S26) is implemented similarly to the said 1st Embodiment.

  On the other hand, when the automobile is located on the expressway, it is determined that the automobile is located on the expressway based on the map information stored in advance and the location information acquired by the GPS receiver. In this case, YES is determined in the step S24c, the process proceeds to the next step S25a, and the normal control TEO is calculated in the same manner as in the step S25.

  According to this embodiment described above, when it is determined YES in step S24c that the automobile is located on the highway, the process proceeds to the next step S25a to calculate the normal control TEO.

  Generally, when driving on a high-speed road lane, idle stop is not performed unless traffic jams or accidents occur. For example, when an idle stop is performed in a highway service area to calculate a drop control TEO, and the electromagnetic clutch 2 is turned on / off based on the drop control TEO, the air temperature blown from the evaporator 9 is Decline and give the passenger a sense of incongruity.

  Therefore, in this embodiment, when it is determined YES in step S24c because the vehicle is located on the highway, the process proceeds to next step S25a to calculate the normal control TEO. For this reason, for example, even if the idle stop is performed in the service area of the expressway, the passenger does not feel uncomfortable due to the temperature of the air blown from the evaporator 9.

(Other embodiments)
In each of the above embodiments, the example using the sensor 32 arranged at the downstream side of the air flow of the evaporator 9 as the temperature detecting means for detecting the temperature of the cooling heat exchanger has been described. A sensor 32 disposed on the surface of the evaporator 9 may be used as temperature detection means for detecting the temperature of the cooling heat exchanger.

  In each of the above embodiments, the heat load in the passenger compartment is used as the target outlet temperature TAO in order to calculate the target evaporator temperature TEO, but instead of this, the passenger compartment temperature Tr, the outside air temperature Tam, and the solar radiation amount Ts. The target evaporator temperature TEO may be obtained using any one of the detections as a heat load in the passenger compartment.

In each of the above-described embodiments, once the idling stop is performed, the example in which the target evaporator temperature TEO is set to the decrease control TEO (second target temperature) until the next idling stop is described. Instead of this, the following (1) and (2) may be used.
(1) When a change in the vehicle speed occurs, it may be determined that there is a possibility that the idle stop is performed, and the target evaporator temperature TEO may be set to the decrease control TEO until the next idle stop is performed. . In this case, it is determined that there is a possibility that the idle stop may be performed when the average vehicle speed decreases or when the vehicle speed rapidly decreases.
(2) It may be determined whether or not there is a possibility that an idle stop is performed using a GPS receiver of a car navigation system, road-to-vehicle communication, vehicle-to-vehicle communication, or the like. For example, there is a possibility that idling stop may be performed when vehicle position information is acquired by a GPS receiver, road-to-vehicle communication, vehicle-to-vehicle communication, etc., and it is determined that the vehicle is traveling in the city based on this position information. It may be determined that there is. Alternatively, it may be determined that there is a possibility that an idle stop may be performed when traveling on a road in a traffic jam.

  In each of the above embodiments, the example in which the decrease control TEO is set to a temperature lower than the minimum value of the normal control TEO by a predetermined value has been described, but instead of this, the minimum value of the normal control TEO is used as the decrease control TEO. The following temperature may be set.

DESCRIPTION OF SYMBOLS 1 Compressor 4 Driving engine 2 Electromagnetic clutch 3 Belt 5 Air conditioner ECU
6 Condenser 7 Receiver 8 Expansion valve 8a Temperature sensing part 9 Evaporator (heat exchanger for cooling)
20 Hot water heater core (heat exchanger for heating)
32 sensor (temperature detection means)
33 sensor 34 sensor 35 sensor 37a operation switch 80 engine ECU
R Refrigeration cycle equipment

Claims (5)

A vehicle air conditioner applied to a vehicle having an idle stop function of stopping a traveling engine (4) when the vehicle is stopped,
A compressor (1) which constitutes a refrigeration cycle apparatus (R) and compresses a refrigerant by kinetic energy output from the traveling engine;
A cooling heat exchanger (9) for constituting the refrigeration cycle apparatus and cooling air with the refrigerant;
An air outlet (51, 53, 55) for blowing the conditioned air that has passed through the cooling heat exchanger into the passenger compartment;
Temperature detection means (32) for detecting the temperature of the cooling heat exchanger;
Control means (S7, S9, S20 to S26, S26a, S25a, S24c) for controlling the compressor so that the temperature detected by the temperature detection means approaches the target temperature;
Calculation means (S25) for calculating a first target temperature as the target temperature based on a thermal load in the vehicle interior;
When the idle stop is not performed, the control unit sets the target temperature to the first target temperature, and when the idle stop is performed, the control unit performs the next idle stop. The vehicle air conditioner is characterized in that the target temperature is set to a second target temperature that is equal to or lower than the first target temperature.   The said control means sets a target temperature to the said 1st target temperature, when the said idle stop is not implemented over a fixed period after the said idle stop is implemented, The target temperature is characterized by the above-mentioned. Vehicle air conditioner.   When the idle stop is performed, the control means estimates an idle stop execution time predicted to be executed next, and the second target temperature is increased as the estimated idle stop execution time becomes longer. The vehicle air conditioner according to claim 1, wherein the air conditioner is set to be low. A blower (11) for generating an air flow for blowing the conditioned air that has passed through the cooling heat exchanger from the air outlet into the vehicle interior;
The control means controls the blower so that the amount of air passing through the cooling heat exchanger is reduced when the idle stop is performed compared to when the idle stop is not performed. The vehicle air conditioner according to any one of claims 1 to 3.   The control means sets the first target temperature to the target temperature even when the idle stop is performed when it is determined that the vehicle is traveling on an expressway. The vehicle air conditioner according to any one of 4.

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