JP2004098975A - Air conditioner for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain generation of odor from an evaporator with improving fuel economy to the level of not sharply loosing air-conditioning feeling of an occupant overpassing the limit in an air conditioner for a vehicle loaded on an idle stop vehicle. <P>SOLUTION: In this air conditioner for a vehicle, a compressor 1 is stopped in stopping with idle stop and it is re-driven when temperature TE of an evaporator 5 is above a predetermined temperature TEO0 during stopping with idle stop. The predetermined temperature TEO0 is variably set to be a lower temperature as temperature distribution deviation of the evaporator 5 is larger just before stopping with idle stop. Thereby, even when the temperature distribution deviation is large, temperature increase up to the level of separating of odorous component at the coolant flow downstream part of the evaporator 5 can be restrained, and when the temperature distribution deviation is small, a time period from stopping of the compressor 1 to re-starting of it can be long, and thereby the fuel economy can be improved. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle air conditioner mounted on an idle stop vehicle that automatically stops a vehicle engine when the vehicle stops.
[0002]
[Prior art]
2. Description of the Related Art In recent years, vehicles for automatically stopping a vehicle engine when stopping at a traffic light or the like (idle stop vehicles such as hybrid vehicles) have been increasing in order to protect the global environment and improve fuel efficiency of vehicle engines. Vehicle air conditioners mounted on such an idle stop vehicle and driving a compressor of a refrigeration cycle by a vehicle engine are disclosed in Patent Documents 1 and 2 below.
[0003]
[Patent Document 1]
JP 2001-180260 A
[Patent Document 2]
JP, 2000-374288, A In the air-conditioning system, the compressor is stopped as much as possible when the vehicle stops at the idle stop to improve the fuel efficiency of the vehicle engine. When the compressor is stopped, the temperature TE of the evaporator rises.However, if the evaporator is sufficiently cooled while the vehicle is running, the air blown into the passenger compartment is generated by the heat capacity of the evaporator for several tens of seconds. Can be cooled. However, if the temperature TE of the evaporator becomes higher than the predetermined temperature TEO0 during the idle stop, the compressor is restarted so that the air conditioning feeling of the occupants during the idle stop is not exceeded beyond the limit. Driven.
[0005]
Incidentally, the compressors described in Patent Documents 1 and 2 are designed to be switched by a vehicle engine and a motor, and the compressor is re-driven by the motor during an idle stop stop, and thereafter, only the motor is driven. Then, when the power becomes insufficient, the compressor is driven by the engine.
[0006]
[Problems to be solved by the invention]
By the way, when the condensed water on the surface of the evaporator dries out in the process of increasing the evaporator temperature TE, the odor component dissolved in the condensed water is separated from the evaporator and blown out into the passenger compartment together with the blast air to the occupant. The problem of giving discomfort has conventionally been known.
[0007]
Here, the temperature of the downstream portion of the refrigerant flow in the evaporator is higher than that of the upstream portion, and the temperature distribution in the evaporator has a considerable deviation. Therefore, when the evaporator temperature TE is detected at a substantially central portion of the refrigerant flow as generally performed, the temperature is higher than the detected evaporator temperature TE in the downstream portion of the refrigerant flow of the evaporator.
[0008]
In the air conditioners described in Patent Documents 1 and 2, the predetermined temperature TEO0 is a fixed value regardless of the temperature distribution deviation of the evaporator. If it is large, the temperature will rise to such an extent that the odor component is released at the downstream side of the refrigerant flow of the evaporator as described above.
[0009]
The present invention has been made in view of the above points, and in a vehicle air conditioner mounted on an idle stop vehicle, while improving fuel efficiency to the extent that air conditioning feeling of occupants is not significantly impaired beyond the limit, evaporation The purpose is to suppress the generation of odor from the vessel.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, at least the compressor (1) of the refrigeration cycle driven by the vehicle engine (20) and the refrigerant circulates by the operation of the compressor (1). And an evaporator (5) for cooling the air blown out of the vehicle compartment. The compressor (1) is stopped when the vehicle is idle-stopped to automatically stop the vehicle engine (20). When the temperature (Te) becomes higher than the predetermined temperature (TEO0), the compressor (1) is driven again in the vehicle air conditioner.
It is characterized in that the predetermined temperature (TEO0) is variably set to a lower temperature as the temperature distribution deviation of the evaporator (5) immediately before the stop of the idle stop is larger.
[0011]
Thereby, when the compressor (1) is stopped at the time of the idle stop stop to improve the fuel efficiency, the temperature (Te) of the evaporator (5) becomes higher than the predetermined temperature (TEO0) during the idle stop stop. Since the compressor (1) is re-driven at the first time, it is possible to prevent the air conditioning feeling of the occupant from exceeding the limit and being significantly impaired.
[0012]
Moreover, since the predetermined temperature (TEO0) is set to be lower as the temperature distribution deviation of the evaporator (5) immediately before the vehicle stops at the idle stop is set to a lower temperature, the odor is reduced at the downstream of the refrigerant flow of the evaporator (5). It is possible to suppress a temperature rise to such an extent that the components are separated.
[0013]
When the temperature distribution deviation of the evaporator (5) immediately before the stop of the idle stop is small, the predetermined temperature (TEO0) is variably set to a high temperature, so that the predetermined temperature (TEO0) is fixed to a low temperature. Since the time from stopping the compressor (1) to restarting the compressor (1) can be lengthened, fuel efficiency can be improved.
[0014]
Here, as a specific means for estimating the magnitude of the temperature distribution deviation of the evaporator (5), as in the invention described in claim 2, as the refrigerant flow rate of the evaporator (5) immediately before the stop of the idle stop decreases, Considering that the deviation of the temperature distribution is large.
[0015]
Further, as specific means for estimating the refrigerant flow rate of the evaporator (5) immediately before the stop of the idle stop, the temperature (Te) of the evaporator (5) immediately before the stop of the idle stop is set as in the invention of claim 3. Higher refrigerant flow rates may be considered to be lower. Other examples of the refrigerant flow rate estimating means include a means for estimating from the capacity of the compressor (1) when the compressor (1) is of a variable capacity type, and a means for directly detecting the refrigerant flow rate.
[0016]
Further, in the invention described in claim 4, the compressor (1) is switchably driven by the vehicle engine (20) and the motor (21). When re-driven, it is characterized by being re-driven by the motor (21).
[0017]
As a result, the stop time of the vehicle engine (20) when the vehicle stops, that is, the idle stop stop time, can be lengthened, and the fuel efficiency can be improved.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0019]
FIG. 1 shows an overall configuration of a vehicle air conditioner according to an embodiment of the present invention. As is well known, the refrigeration cycle R for air conditioning includes a compressor 1, a condenser 2, a liquid receiver 3, an expansion valve 4 serving as a pressure reducing means, and an evaporator 5.
[0020]
The air-conditioning case 6 forms a passage through which the conditioned air flows into the vehicle interior, and the evaporator 5 is disposed in the air-conditioning case 6. The evaporator 5 is a cooling heat exchanger that cools the conditioned air, and cools the air by absorbing the low-pressure gas-liquid two-phase refrigerant from the expansion valve 4 from the air blown by the blower 7 and evaporating.
[0021]
The blower 7 has a centrifugal blower fan 7a and a fan drive motor 7b. Outside air or inside air is sucked into the suction port 7c of the blower 7 through an inside / outside air switching box (not shown). In the air-conditioning case 6, a heater core 8 is disposed downstream of the evaporator 5.
[0022]
The heater core 8 is a heating heat exchanger that heats conditioned air using hot water as a heat source. A bypass passage 8 a is formed in the air conditioning case 6 on the side (upper side) of the heater core 8. A plate-shaped air mix door 9 is rotatably provided adjacent to the heater core 8 in order to adjust the ratio of the amount of cold air passing through the bypass passage 8a and the amount of warm air passing through the heater core 8. The air mix door 9 is driven by a servo motor 9a.
[0023]
The air that has reached the desired temperature due to the mixing of the cold and hot air passes through the defroster opening 14, the face opening 15, and the foot opening 16, which are opened and closed by the blowing mode switching doors 11, 12, and 13, and the various parts in the vehicle interior (the inner surface of the window glass). , The upper body side of the occupant, the foot side of the occupant). The blowout mode switching doors 11, 12, and 13 are also driven by a servo motor (not shown) similarly to the air mix door 9. Note that warm water (cooling water) of the vehicle engine 20 circulates through the heater core 8.
[0024]
The vehicle engine 20 is a driving source for driving the vehicle and a driving source for auxiliary equipment such as the compressor 1. The motor 21 is a generator / motor (motor generator) that is driven by the vehicle engine 20 when the vehicle engine 20 is operating and acts as a generator. The motor 21 serves as a drive source for driving auxiliary equipment such as the compressor 1 when the vehicle engine 20 is stopped. It functions as a generator for charging and as a starting motor (starter) for starting the vehicle engine 20.
[0025]
More specifically, the motor 21 is a three-phase AC rotating electric machine. When the motor 21 operates as a motor, the motor 21 generates three-phase AC by generating a rotational force on a rotor by a three-phase AC voltage supplied from a drive circuit. When operating as a motor and as a generator, the rotor is driven to rotate by the vehicle engine 20 and becomes a three-phase AC generator that generates electromotive force. The three-phase AC voltage generated by the power generation action of the motor 21 is rectified into DC and charges the vehicle-mounted storage battery 50.
[0026]
An electromagnetic clutch 22 is provided on a crankshaft of the vehicle engine 20, and rotation of the vehicle engine 20 is transmitted to a crank pulley 23 via the electromagnetic clutch 22. The rotation of the crank pulley 23 is transmitted to the pulley 1a of the compressor 1 and the pulley 21a of the motor 21 via the belt 24. The pulley 1a of the compressor 1 is provided with an electromagnetic clutch 25, and the transmission of rotation to the compressor 1 is interrupted by the electromagnetic clutch 25.
[0027]
As described above, the compressor 1 is configured to be switched and driven by the vehicle engine 20 and the motor 21. That is, the compressor 1 is driven by the motor 21 when the vehicle engine 20 is stopped such as when the vehicle is stopped, but the compressor 1 is driven by the vehicle engine 20 when the vehicle engine 20 is operating (during vehicle running).
[0028]
Although not shown in FIG. 1, the rotation of the crank pulley 23 is also transmitted to auxiliary equipment such as a cooling water pump (not shown) and a hydraulic motor for driving a power steering via a belt 24. Therefore, when the vehicle engine 20 is stopped, these accessories can be driven by the motor 21 in the same manner as the compressor 1.
[0029]
Also, instead of the electromagnetic clutch 22 of the crankshaft of the vehicle engine 20, a clutch mechanism (1) that transmits rotational power only from the vehicle engine 20 to the crank pulley 23 side and cuts off power transmission from the motor 21 to the vehicle engine 20 side. Direction clutch). However, in this case, a dedicated starter is separately required for the engine start function.
[0030]
Further, a plurality of pulleys 1a are provided on the compressor 1, and a belt 24 for transmitting power from the vehicle engine 20 to the compressor 1 and a belt 24 for transmitting power from the motor 21 to the compressor 1 are separately provided on each pulley 1a. It may be provided.
[0031]
Further, the compressor 1 of the present embodiment is a variable displacement compressor capable of changing a discharge capacity (a refrigerant discharge amount per one rotation of the compressor). The configuration of the variable displacement compressor 1 is well known, and for example, the configuration described in Japanese Patent No. 2661121 can be used. The variable displacement compressor 1 of this known example has a swash plate connected to a rotating shaft, and the rotation of the swash plate reciprocates a piston that sucks, compresses, and discharges refrigerant.
[0032]
An electromagnetic pressure control device 1b for adjusting the control pressure acting on the swash plate is provided, and the control pressure is adjusted by the amount of current In supplied to the electromagnetic coil of the electromagnetic pressure control device 1b. . By adjusting the control pressure, the stroke of the piston can be changed by changing the inclination angle of the swash plate, and thereby the displacement can be changed. Therefore, the electromagnetic pressure control device 1b constitutes a variable capacity means, and the current amount In may be controlled by either continuous control or duty control.
[0033]
The vehicle engine 20, the motor 21, and the auxiliary equipment (including at least the air conditioner) include control units 30, 31, and 32, respectively. The control units 30, 31, and 32 are composed of a microcomputer and its peripheral circuits, and communicate signals between the control units. Power is supplied to these control units 30, 31, 32 from an in-vehicle storage battery 50 via an ignition switch 51 of the vehicle engine 20.
[0034]
The air-conditioning controller 32 includes, as input sensors, an outside air temperature sensor 33 that detects an outside air temperature Tam, an inside air temperature sensor 34 that detects a vehicle interior temperature Tr, a solar radiation sensor 35 that detects an amount of solar radiation Ts into the vehicle interior, and evaporation. The temperature is supplied to an evaporator temperature sensor 36 for detecting a blow-off air temperature (evaporator temperature) Te as a degree of cooling of the heater 5, a water temperature sensor 37 for detecting a hot water temperature Tw of the heater core 8, and an electromagnetic coil of the electromagnetic pressure control device 1b. A refrigerant flow sensor 44 for detecting the current amount In, a vehicle speed sensor 45 for detecting the vehicle speed SPD, and the like are connected.
[0035]
The signal from the vehicle speed sensor 45 may be input to the air-conditioning control unit 32 via the engine control unit 30.
[0036]
The air conditioner operation panel 38 disposed near the instrument panel in the vehicle compartment includes a temperature setter 39 for setting a set temperature Tset in the vehicle compartment, an air conditioner switch 40 for outputting an intermittent signal of the compressor 1, and a switching signal for a blowing mode. Operation switches such as a blowout mode switch 41 that outputs air, an air volume switch 42 that outputs an air volume switching signal of the blower 7, and an inside / outside air switching switch 43 that outputs an inside / outside air switching signal. The operation signals of these operating members are also controlled for air conditioning. Input to the unit 32.
[0037]
Next, the operation of the present embodiment will be described based on the flowchart of FIG. The air-conditioning control unit 32 performs calculations and processes according to the flowchart of FIG.
[0038]
(1) Normal Air-Conditioning Control Flow The control routine shown in FIG. 2 is started by turning on the ignition switch 51 of the vehicle engine. First, a signal is read in step S100.
[0039]
That is, a signal indicating the vehicle environment state such as the vehicle interior temperature Tr, the outside air temperature Tam, the hot water temperature (cooling water temperature) Tw, the solar radiation amount Ts, and the evaporator outlet temperature Te detected by the various sensors 33 to 37, and the air conditioning operation panel 38 , An operation signal from the engine control unit 30, a motor operation signal from the motor (MG) control unit 31, a current amount In supplied to the electromagnetic coil of the electromagnetic pressure control device 1b. And a signal such as a vehicle speed SPD is read.
[0040]
Next, in step S200, it is determined whether the air conditioner switch 40 is ON or OFF. When the air conditioner switch 40 is ON, the process proceeds to step S300, where the target outlet temperature TAO of the air blown into the vehicle interior, the target air volume level BLW of the blower 7, the target opening degree SW of the air mix door 9, and the target evaporator outlet temperature TEO. Is calculated in the same manner as in the normal auto air conditioner control.
[0041]
That is, the target outlet temperature TAO is the outlet temperature into the vehicle compartment necessary to maintain the vehicle interior at the set temperature Tset set by the occupant, and the TAO is calculated based on Tset, Tam, Tr, and Ts. The target airflow level BLW of the blower 7 is calculated based on TAO, the target opening degree SW of the air mix door 9 is calculated based on TAO, Te, Tw, and the target outlet temperature TEO of the evaporator 12 is TAO, Tam, etc. Is calculated based on
[0042]
Next, proceeding to step S400, in accordance with the vehicle speed SPD signal read in step S100, if the vehicle speed has not decreased and the vehicle has not started decelerating, the same as the normal auto air conditioner control calculated in step S300. The process proceeds to step S1300 with the calculation result.
[0043]
On the other hand, when the deceleration is started, the flow proceeds to the flow of the control at the time of deceleration and the control at the time of the idling stop stop after step S500 shown in FIG. In these controls after step S500, the compressor 1 is controlled by changing TEO, which is the calculation result of the normal automatic air conditioner control. The details of the air conditioning control flow during deceleration and during idle stop stop will be described later.
[0044]
In step S1300, various control signals for the air mix door target opening degree SW, the target evaporator outlet temperature TEO, and the target airflow level BLW calculated in step S300 are output to various control means.
[0045]
That is, the operating angle of the servo motor 9a for driving the air mix door 9 is controlled so that the actual opening of the air mix door 9 becomes the target opening SW. As for the air volume of the blower 7, the applied voltage of the drive motor 7b of the blower 7 is controlled so that the target air volume level BLW is obtained. The applied voltage control of the drive motor 7b may be not only continuous control but also pulse width modulation control (PWM control).
[0046]
As for the control of the compressor 1, the displacement of the variable displacement compressor 1 is variably controlled so that the actual evaporator outlet temperature Te detected by the temperature sensor 36 becomes the target value TEO. Even when the variable displacement compressor 1 has the minimum capacity, when the evaporator outlet temperature Te is lower than the target value TEO and when the compressor 1 does not need to be operated, the electromagnetic clutch 25 is shut off and the compressor 1 is stopped.
[0047]
(2) Air-conditioning control flow at the time of deceleration and idle stop stop The flow from step S500 shown in FIG. 3 is the flow of air-conditioning control (eco-run air-conditioning control) at the time of deceleration and idle stop stop. The time chart shown in FIG. 4 shows the vehicle speed SPD when the control is changed from the normal air-conditioning control, the air-conditioning control during deceleration, the air-conditioning control when idling stop is stopped, and the normal air-conditioning control in the process of decelerating and stopping the vehicle at the idle stop. It shows changes in the target evaporator temperature TEO, the evaporator temperature Te by the evaporator temperature sensor 36, and the current amount In as the discharge capacity of the compressor 1.
[0048]
First, in step S500, the current amount In _n-1 and the target blowing temperature TEOn _-1 supplied to the electromagnetic coil of the electromagnetic pressure control device 1b at that time are stored. Next, the process proceeds to step S600, in which the value of TEO calculated in step S300 is changed to the lower limit. The lower limit is a low temperature (for example, 3 to 4 ° C.) at which the evaporator 5 does not floss.
[0049]
Next, the process proceeds to step S700, in which it is determined whether or not the vehicle is decelerating based on the vehicle speed SPD signal or the like. If not, the process proceeds to step S1200 and the target outlet temperature TEO changed in step S600 is determined in step S300. Is returned to the value of the target outlet temperature TEO at the time of the normal air-conditioning control calculated in.
[0050]
On the other hand, if the vehicle is decelerating, the process proceeds to step S900, and the driving of the compressor 1 is controlled based on the lower limit TEO changed in step S600. That is, the capacity of the variable displacement compressor 1 is variably controlled so that the actual evaporator outlet temperature Te becomes the target value TEO. In the time chart of FIG. 4, the discharge capacity of the compressor 1 is maximized.
[0051]
Then, it is determined in step S900 whether or not the vehicle has stopped. If it is not determined that the vehicle has stopped, the process returns to step S700, and the deceleration-time air conditioning control in step S800 is continued. If it is determined that the vehicle is stopped, the process proceeds to step S1000, and a predetermined value TEO0 is calculated and set based on the current amount In _n-1 and the target blowing temperature TEOn _n-1 stored in step S500.
[0052]
Specifically, as the discharge capacity of the compressor 1 immediately before the stop of the idle stop is smaller, the temperature distribution deviation of the evaporator 5 immediately before the stop of the idle stop is considered to be larger, and the predetermined value TEO0 is set lower. In the present embodiment, as the value of the current amount In _n-1 is smaller, the discharge capacity is smaller. Further, it is considered that the higher the target outlet temperature TEOn _-1 immediately before the stop of the idle stop, the larger the temperature distribution deviation of the evaporator 5 immediately before the stop of the idle stop, and the predetermined value TEO0 is set lower.
[0053]
That is, the predetermined value TEO0 is set to be variable to a lower temperature as the temperature distribution deviation of the evaporator 5 immediately before the stop of the idle stop is larger, and to be set to a higher temperature as the temperature distribution deviation is smaller. The solid line TEOLo in FIG. 4 indicates the target evaporator temperature TEO and the actual evaporator temperature Te when the predetermined value TEO0 is set to a low temperature, and the one-dot chain line TEOHi in FIG. The table shows the values of the target evaporator temperature TEO and the actual evaporator temperature Te when TEO0 is set to a high temperature.
[0054]
When the compressor 1 is driven by the motor 21, the performance of the compressor 1 is reduced as compared with when the compressor 1 is driven by the vehicle engine 20. The value TEO0 is set to a temperature higher than the target outlet temperature TEOn _-1 immediately before the stop of the idle stop.
[0055]
Next, the process proceeds to step S1100 to perform idle stop vehicle stop air conditioning control. Specifically, when the actual temperature Te of the evaporator 5 rises and becomes equal to or more than the predetermined value TEO0, the compressor 21 is driven again by driving the motor 21. If the cooling capacity of the evaporator 5 is insufficient just by driving the motor 21, the vehicle engine 20 is started and the compressor 1 is driven using the engine 20 as a drive source as shown in a time chart of FIG. At the same time, the process proceeds to step S100, and normal air conditioning control is performed.
[0056]
As described above, according to the present embodiment, the compressor 1 is stopped at the time of the idle stop stop, and when the temperature TE of the evaporator 5 becomes higher than the predetermined temperature TEO0 during the idle stop stop, the compressor 1 is driven again. In the vehicular air conditioner, the predetermined temperature TEO0 is variably set to a lower temperature as the temperature distribution deviation of the evaporator 5 immediately before the stop of the idle stop is larger. Thereby, even if the temperature distribution deviation is large, it is possible to suppress the temperature from rising to such an extent that the odor component is separated at the downstream portion of the refrigerant flow of the evaporator 5, and when the temperature distribution deviation is small, The time from stopping the compressor 1 to restarting the compressor 1 can be lengthened, and the fuel efficiency can be improved.
[0057]
Further, in the present embodiment, since the temperature of the evaporator 5 is reduced by utilizing the deceleration energy by the deceleration-time air conditioning control in step S800, the time from when the idle stop is stopped to when the motor 21 is driven may be lengthened. And fuel efficiency can be further improved.
[0058]
Further, in the present embodiment, since the predetermined value TEO0 is set to a temperature higher than the target blowing temperature TEOn _-1 immediately before the stop of the idle stop, the time from the stop of the idle stop to the drive of the motor 21 is increased. Fuel economy can be further improved.
[0059]
(Other embodiments)
In the above-described embodiment, a case where a variable displacement compressor is used as the compressor 1 and the evaporator temperature Te is controlled to the target value TEO by variably controlling the capacity of the variable displacement compressor 1 is described. As described above, a normal fixed displacement type compressor is used as the compressor 1, and the operation of the fixed displacement type compressor 1 is intermittently operated by the electromagnetic clutch 25 to change the operating rate of the compressor 1 so as to discharge the evaporator. The temperature Te may be controlled to be equal to the target value TEO.
[0060]
In the above-described embodiment, the motor 21 also serving as a generator is used as a drive source of the compressor 1. However, the motor 21 is dedicated to a drive source of auxiliary machines such as the compressor 1 and the generator is separately provided. You may. Further, in the above-described embodiment, the compressor 1 and the drive motor 21 are configured separately, but the drive motor 21 may be configured integrally with the compressor 1. In short, any compressor drive mechanism that can drive the compressor 1 by the vehicle engine 20 when the engine is operating and drive the compressor 1 by the motor 21 when the engine is stopped. Therefore, the connection relationship among the compressor 1, the vehicle engine 20, the motor 21, and the generator can be variously changed.
[0061]
Further, the motor 21 may be omitted in implementing the present invention. Specifically, in the idle-stop vehicle-stop air conditioning control in step S1100, when the actual evaporator 5 temperature Te rises to a predetermined value TEO0 or more, the vehicle engine 20 is started, and the compressor 1 is driven using the engine 20 as a drive source. May be re-driven, and the process may proceed to step S100 to perform normal air conditioning control.
[0062]
FIG. 1 shows an example in which the engine control unit 30 outputs an on / off signal of the electromagnetic clutch 25 of the compressor 1 from the engine control unit 30. Of course, it is also possible to output from.
[0063]
In addition, it goes without saying that the engine control unit 30, the motor control unit 31, and the air conditioning control unit 32 separately illustrated in FIG. 1 may be integrated as one control device.
[0064]
Further, the vehicle air conditioner of the present invention is not limited to application to a passenger car, but may of course be applied to a bus.
[Brief description of the drawings]
FIG. 1 is an overall system diagram of a vehicle air conditioner according to an embodiment of the present invention.
FIG. 2 is a flowchart showing the operation of the system of FIG.
FIG. 3 is a flowchart showing a main part of FIG. 2;
FIG. 4 is a diagram showing a time chart by the system of FIG. 1;
[Explanation of symbols]
1 ... Compressor, 5 ... Evaporator, 20 ... Vehicle engine, TEO0 ... Predetermined temperature.

Claims (4)

A refrigerating cycle compressor (1) driven by at least a vehicle engine (20);
An evaporator (5) for circulating a refrigerant by the operation of the compressor (1) to cool the air blown into the vehicle interior;
When the vehicle engine (20) is automatically stopped at an idle stop, the compressor (1) is stopped,
When the temperature (Te) of the evaporator (5) becomes higher than a predetermined temperature (TEO0) during the stop of the idle stop, the compressor (1) is re-driven to provide a vehicle air conditioner. ,
An air conditioner for a vehicle, wherein the predetermined temperature (TEO0) is variably set to a lower temperature as the temperature distribution deviation of the evaporator (5) immediately before the stop of the idle stop increases. The predetermined temperature (TEO0) is variably set to a lower temperature on the assumption that the smaller the refrigerant flow rate of the evaporator (5) immediately before the idle stop is stopped, the larger the deviation of the temperature distribution is. Item 2. The vehicle air conditioner according to item 1. It is considered that the higher the temperature (Te) of the evaporator (5) immediately before the stop of the idle stop, the smaller the refrigerant flow rate is, and the predetermined temperature (TEO0) is variably set to a lower temperature. Item 3. The vehicle air conditioner according to item 2. The compressor (1) is switchably driven by the vehicle engine (20) and a motor (21),
The vehicle air conditioner according to any one of claims 1 to 3, wherein when the compressor (1) is restarted while the idle stop is stopped, the compressor (1) is restarted by the motor (21). apparatus.

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