JP3261099B2 - Vehicle air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner. More specifically, the present invention relates to a vehicle air conditioner that enables efficient air conditioning even when an engine that drives a compressor stops intermittently.

[0002]

2. Description of the Related Art An air conditioner (hereinafter, referred to as an "air conditioner") provided in a vehicle rotates or drives a compressor by the driving force of an engine to cool or dehumidify air blown into a vehicle compartment.

[0003] In recent years, hybrid vehicles provided with an electric motor in addition to an engine as a driving source for traveling have been widely used in vehicles for the purpose of energy saving, and so-called eco-run vehicles and the like in which the engine is stopped when the vehicle is stopped. Considerations are being made. In such a hybrid vehicle or eco-run vehicle, the engine is intermittently stopped, and the rotation of the compressor is also stopped along with the stop of the engine.

On the other hand, an air conditioner provided in a vehicle is:
Generally, based on operating conditions such as a set temperature and environmental conditions such as a temperature in a vehicle compartment and a temperature outside the vehicle, a target outlet temperature is set so that the temperature in the vehicle compartment becomes the set temperature. In the air conditioner, the temperature of the air that has passed through the evaporator (the temperature after the evaporator) is set based on the outside air temperature (the target temperature after the evaporator), and the compressor is turned on / off so that the temperature after the evaporator becomes the target temperature after the evaporator. Or, the capacity of the compressor is controlled to enable efficient air conditioning.

[0005]

However, when the vehicle engine stops, the compressor stops regardless of the temperature after the evaporator. In an air conditioner, when the compressor stops, the cooling of the air by the evaporator also stops, so that not only the temperature of the air blown into the vehicle compartment but also the humidity rises, and there is a problem that the comfort in the vehicle compartment is impaired.

Particularly, in a hybrid vehicle or an eco-run vehicle, the engine is intermittently stopped, so that the comfort in the vehicle compartment is impaired. If the engine is started to rotate the compressor when the temperature after the evaporator rises in order to solve this, the energy saving effect will be impaired.

The present invention has been made in view of the above-mentioned circumstances, and proposes an air conditioner for a vehicle in which the comfort in a vehicle compartment is prevented from being impaired when an engine that rotationally drives a compressor is stopped. The purpose is to:

[0008]

The invention according to claim 1 is
An air conditioner for a vehicle that cools air blown into a vehicle interior by a refrigeration cycle including a compressor and an evaporator that are rotationally driven by an engine of a vehicle that is intermittently operated , wherein a post-evaporator temperature is a temperature of air that has passed through the evaporator. Temperature detecting means for detecting a temperature of the vehicle, a post-evaporator temperature setting means for setting a target post-evaporator temperature based on the environmental condition of the vehicle detected by the environmental condition detecting means, and a temperature detected by the temperature detecting means being the post-evaporator temperature setting means. and a control means for controlling driving of the compressor as was set as a target post-evaporator temperature by the estimating means an engine for driving the compressor to estimate whether the previous stop, said estimating means intermittently It is assumed that the engine has not stopped before driving.
And a post-evaporator temperature changing means for changing the target post-evaporator temperature set by the post-evaporator temperature setting means when the temperature is set.

According to the present invention, the engine is controlled according to the driving situation.
Vehicles with intermittent operation that repeatedly stops and starts the gin (for example,
For example, in a hybrid vehicle or an eco-run vehicle), a target post-evaporator temperature is set based on environmental conditions, and ON / OFF control of the compressor or control of compressor capacity is performed so that the post-evaporator temperature becomes the target post-evaporator temperature.

On the other hand, the estimation means estimates whether the engine for driving the compressor is likely to stop, while
When there is a high possibility that the engine will stop in the non- operation, the post-evaporator temperature changing means lowers the target post-evaporator temperature than the target post-evaporator temperature set by the post-evaporator temperature setting means. That is, the estimation
By means, before the engine is stopped in intermittent operation
The temperature after the target evaporator
If the evaporator is cooled, the engine stops and the
If the presser also stops, the comfort in the cabin may be impaired.
There is no. Also, when the engine stops, the compression
Eliminates the need to start the engine to drive the engine
Therefore, the energy saving of the vehicle is not impaired.

Thus , if the engine stops and the compressor also stops in the intermittent operation, the temperature of the evaporator is lower than the normal temperature. Therefore, it is possible to suppress an increase in the temperature of the air passing through the evaporator when the compressor is stopped, and to cause discomfort due to the air passing through the evaporator being blown into the vehicle compartment when the compressor is stopped. Can be prevented from occurring. In addition, since the temperature of the evaporator is lowered, it is possible to prevent the windshield glass from fogging.

[0012]

[0013]

According to a second aspect of the present invention, the estimating means includes a vehicle speed sensor, and estimates that the engine is stopped when the speed of the vehicle detected by the vehicle speed sensor falls below a predetermined speed. And

According to the present invention, whether or not the engine stops is estimated from the vehicle speed. That is, when the vehicle is running at a high speed, the possibility that the vehicle will stop within a relatively short time is extremely low, and therefore the possibility that the engine will stop is low. Therefore, it can be estimated that the engine does not stop.

When the vehicle speed is low, there is a high possibility that the vehicle stops after deceleration, so it can be estimated that the engine stops. Note that the reference speed for the determination can be set based on the time required for lowering the temperature of the evaporator and the time from the speed until the vehicle is substantially stopped.

As the estimating means, a throttle sensor for detecting the opening of the throttle valve of the engine and a brake sensor for detecting the operation of the brake pedal can be used in place of the vehicle speed sensor. By using this together with, it is possible to more accurately determine the possibility of stopping the engine.

According to a third aspect of the present invention, the environmental condition detecting means includes a solar radiation sensor for detecting an amount of solar radiation, and the post-evaporator temperature changing means sets a target post-evaporator temperature in accordance with the amount of solar radiation detected by the solar radiation sensor. It is characterized by determining whether or not to change.

According to the present invention, it is determined whether or not to change the target post-evaporator temperature based on the environmental conditions detected by the solar radiation sensor, that is, the amount of solar radiation.

Generally, the target post-evaporator temperature is set on the basis of the outside air temperature. However, even in the case where the outside air temperature is low and the sunshine is large and the amount of solar radiation is large, the comfort in the vehicle compartment is suddenly increased even when the compressor is stopped. It does not get worse.

From this, the temperature after the target evaporator is reduced only when the amount of solar radiation detected by the solar radiation sensor is low. As a result, it is possible to prevent the operation time of the compressor, which is a load on the engine, from being lengthened to lower the temperature after the target evaporator more than necessary, thereby preventing the energy saving effect from being reduced.

The environment outside the vehicle can be used as an environmental condition for determining whether or not to change the temperature after the target evaporator. For this reason, the humidity may be detected, and the wiper of the vehicle may operate. It may be detected whether or not it is performed.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 shows a schematic configuration of an air conditioner 10 applied as a vehicle air conditioner to this embodiment. The air conditioner 10 has an air inlet 1 at one open end.
An air-conditioning duct 18 is provided at the other open end, and an air outlet 16 is formed at the other open end, and the air-conditioning duct 18 is arranged in an instrument panel of the vehicle.

In the air conditioning duct 18, the blower fan 2
0, an evaporator 22, an air mix damper 24, and a heater core 26 are provided. A switching damper 28 is provided near the air inlets 12 and 14, and a mode switching damper 30 is provided near the air outlet 16. The air conditioner 10
By operating the blower motor 38, the blower fan 20 is rotationally driven to suck air from the air inlets 12 and 14 and send the air toward the evaporator 22. All of this air passes through the evaporator 22.
In the air conditioner 10, the switching damper 28 opens the air intake 12 communicating with the outside of the vehicle to enter the outside air introduction mode, and opens the air intake 14 communicating with the vehicle interior to enter the inside air circulation mode. Become.

The evaporator 22 forms a refrigeration cycle in which a refrigerant is circulated between the compressor 32, a condenser (not shown), an expansion valve, and the like.
This refrigeration cycle can use a general configuration,
Detailed description is omitted.

When the engine 34 is driven, the driving force of the engine 34 is transmitted and the compressor 32 is driven to rotate. The rotation of the compressor 32 causes the refrigerant to circulate between the evaporator 22 and cools the air passing through the evaporator 22.

An air mix damper 24 provided between the evaporator 22 and the heater core 26 separates an air passage passing through the heater core 26 and an air passage bypassing the heater core 26. The air separated by the air mix damper 24 is mixed near the outlet 26.

A cooling water circulation path is formed in the heater core 26 with the engine 34, and the cooling water is circulated in the heater core 26 by the operation of a circulation pump (not shown). Thereby, the air passing through the heater core 26 is
Heated by cooling water being heated by the engine 34.

Therefore, the air heated by the heater core 26 near the outlet 16 and the air cooled by the evaporator 22 by bypassing the heater core 26 are mixed, and the mixed air is blown out as conditioned air. It is blown out from the mouth 16. At this time, in the air conditioner 10, by controlling the opening degree of the air mix damper 24 to adjust the amount of air passing through the heater core 26 and the amount of air bypassing the heater core 26, the temperature of the conditioned air blown from the outlet 16 ( Blowout air temperature) can be controlled.

On the other hand, the outlet 16 includes a VENT outlet 40, a HEAT outlet 42 and a defroster outlet 4.
The system is roughly divided into three systems. VENT outlet 40
Is composed of a center register 40A, side registers 40B, 40C and the like arranged on the front instrument panel, and mainly blows out conditioned air toward the occupant seated in the front seat. The HEAT outlet 42 includes a foot outlet 42A opened toward the feet of the occupant seated in the front seat and a foot outlet 42B opened toward the feet of the occupant seated in the rear seat. It is configured.
Further, the defroster outlet 44 is constituted by a center defroster 44A and side defrosters 44B and 44C, and mainly blows out conditioned air toward the windshield glass.

When the VENT outlet 40, the HEAT outlet 42, and the defroster outlet 44 are opened and closed by the mode switching damper 30, the air conditioner 10 operates in the VENT mode in which air is blown out from the VENT outlet 40, the HEAT mode. HEAT mode in which air is blown out from outlet 42, DEF mode in which air is blown out from defroster outlet 44, VENT outlet 40 and HEAT
A Bi-LEVEL mode for blowing air from the outlet 42 and a HEAT / DEF mode for blowing air from the HEAT outlet 42 and the defroster outlet 44 are provided.

The air conditioner 10 includes an air conditioner ECU 36 having a microcomputer. Connected to the air conditioner ECU 36 are servo motors 46A, 46B, 46C for operating the switching damper 28, the air mix damper 24, and the mode switching damper 30, and a controller 48 for driving the blower motor 38.

The air conditioner ECU 36 includes an outside air temperature sensor 50 for detecting the temperature outside the vehicle, a room temperature sensor 52 for detecting the temperature inside the vehicle, and a solar radiation sensor 5 for detecting the amount of solar radiation.
4. A post-evaporator temperature sensor 56 for detecting the temperature of the air passing through the evaporator 22, a vehicle speed sensor 58 for detecting the running speed of the vehicle, a water temperature sensor 60 for detecting the temperature of the cooling water of the engine 34, and an operation panel 62 are connected. ing.

Further, the air conditioner ECU 36 is connected to the engine ECU 64, and when the compressor 32 is turned on while the engine 34 is operating, the engine ECU 6 is turned on.
4 to output a request for driving the compressor 32. When there is a drive request for the compressor 32, the engine ECU 64
Turn on the magnet switch (not shown) to set the engine 34
Is transmitted to the compressor 32. Thus, the compressor 32 is rotationally driven by the driving force of the engine 34.

On the other hand, as shown in FIG. 2, an operation panel 62 has an outlet switching dial 68 for switching the outlet 16, a blower air volume switching dial 70 for switching a blower level which is an air volume of the outlet 16, and a set temperature. A set temperature dial 72 to be changed, an auto mode switch 74 operated when selecting the auto mode, an inlet switch 7 for switching between an inside air circulation mode and an outside air introduction mode.
6. Air conditioner switch 7 for turning on / off air conditioner 10
8 and a FULL switch 66 for selecting the maximum capacity of the air conditioner 10 are provided. The operation state of each switch on the operation panel 62 is read by the air conditioner ECU 36.

When the operation of the auto mode is instructed by operating the auto mode switch 74 and the air conditioner switch 78, the air conditioner ECU 36 activates the engine ECU.
A request to turn on the magnet switch is issued to
Based on environmental conditions such as room temperature and a set temperature, the target blow temperature, the opening degree of the air mix damper 24, the blower level (air volume of the blower fan 20), the blow mode, and the like are set. Perform air-conditioning operation.

When performing the air conditioning operation in the manual mode with the auto mode switch 74 turned off, the air conditioner ECU 36 sets the target outlet temperature and the opening degree of the air mix damper 24 based on the set temperature and environmental conditions. The result of this setting and the blowing mode set by the outlet switching dial 68, the blower air volume switching dial 7
It operates based on the blower level set by 0.

At this time, the target outlet temperature T _AO is obtained from the set temperature T _SET , the room temperature _Tr , the outside air temperature T _O , and the amount of solar radiation ST.
It is obtained by the following equation.

T _AO = k ・ T _SET -k ₂・ T _r -k ₃・ T
_O -k ₄ · ST + C _{(however, k 1, k 2, k} 3, k 4, C is a predetermined constant) On the other hand, the air temperature T _A, the engine 34 is the temperature of the evaporator after the temperature T _E and the heater core 36 determined by the temperature T _W and opening S of the air mixing damper 24 of the cooling water. At this time, the evaporator temperature TE and the cooling water temperature T _E are set so that the blow temperature T _A becomes the target blow temperature T _AO.
The opening degree S of the air mix damper 24 is calculated based on _W , and the servo motor 46B is controlled based on the calculation result.

As described above, the basic configuration of the air conditioner 10 is substantially the same as that of a conventionally known vehicle air conditioner.

In the air conditioner 10, an outside air temperature sensor 50 is provided in addition to the inside air circulation mode or the outside air introduction mode.
The target post-evaporator temperature T _EO is determined based on environmental conditions detected by environmental condition detecting means, such as the outside air temperature T _O detected by the vehicle speed sensor 58, the vehicle speed V detected by the vehicle speed sensor 58, and the solar radiation amount ST detected by the solar radiation sensor 54,
As post-evaporator temperature T _E is the target post-evaporator temperature T _EO, and controls the on / off compressor 32.

FIGS. 3A to 3D are diagrams used when the air conditioner ECU 36 determines the evaporator temperature T _EO based on the outside air temperature T _O , the vehicle speed V, and the solar radiation ST. I have. The air conditioner ECU 36 stores a map of the target post-evaporator temperature T _EO with respect to the outside air temperature T _O based on the solar radiation amount ST and the vehicle speed V. The air conditioner ECU 36 calculates the target post-evaporator temperature T _EO based on this map. The ON / OFF of the compressor 32 (the cooling capacity by the compressor 32) is controlled so that the determined temperature T _E after the evaporator becomes the target temperature T _EO after the evaporator.

That is, the air conditioner ECU 36 sets the solar radiation amount ST in a plurality of stages (in the present embodiment, as an example,
(3 stages of medium and weak), divided into an outside air introduction mode and an inside air circulation mode, and a target post-evaporator temperature T _EO with respect to the outside air temperature T _O is set for each of them.

On the other hand, the air conditioner ECU 36 determines whether or not the vehicle may stop based on the vehicle speed V detected by the speed sensor 58. If the vehicle speed V is high, there is no possibility that the vehicle will stop in a short time and turn off the engine 34, but if the vehicle speed is low, there is a possibility that the vehicle will stop and turn off the engine 34.

From here, the air conditioner ECU 36 calculates the vehicle speed V
When the vehicle is traveling at or below a predetermined speed V ₀ (eg, 65 km / h), it is estimated that the vehicle may stop. When the air conditioner ECU 36 determines that there is a high possibility that the vehicle will be stopped, the target post-evaporator temperature T _EO
So that when the engine 34 is stopped, the temperature of the evaporator 22 is lower than a required temperature.

At this time, if it can be determined that, for example, the windshield glass is less likely to be fogged even if the air that has passed through the evaporator 22 while the compressor 32 is stopped is blown into the vehicle interior, the target post-evaporator temperature T _EO is determined. Although it is not changed, in particular, the amount of solar radiation S determined to be highly likely to fog the windshield glass
When T is small, the target post-evaporator temperature T _EO is lowered, and the evaporator 22 is cooled in advance.

That is, in the outside air introduction mode, even if the compressor 32 is stopped, the air blown into the vehicle interior from the air outlet 16 does not cause the windshield glass to be fogged as long as it is in the sunshine or more. Vehicle speed V
Is lower, the target post-evaporator temperature T _EO is determined based on the insolation ST and the outside air temperature T _O.

On the other hand, as shown in FIGS. 4 (A) and 4 (B), in the case of low solar radiation, when air passing through the evaporator 22 in a state where the compressor 32 is stopped is blown into the vehicle interior, anti-fogging is performed. If the vehicle speed V is lower than the speed V ₀ and it is determined that there is a high possibility that the vehicle stops, the target post-evaporator temperature T _EO is determined to be higher than the speed V ₀ . Set so that it is lower than when it is high.

[0049] Thus, the engine 34 is to suppress an increase in the post-evaporator temperature T _E by stopping the compressor 32 to the stop.

As shown in FIG. 5A, the compressor 32 includes, for example, a post-evaporator temperature sensor 56.
When the post-evaporator temperature T _E for detecting drops than after the target evaporator temperature T _EO by the off, post-evaporator temperature T _E is turned on when 1 ℃ higher than after the target evaporator temperature T _EO.

As shown in FIG. 5B, the amount of solar radiation ST is equal to a predetermined value ST ₁ , ST ₂ , ST ₃ , ST ₄ (S
T ₁ <ST ₂ <ST ₃ <ST ₄ ) is set (for example, ST ₁
= 210 w / m ² , ST ₂ = 310 w / m ² , ST ₃ = 42
0 w / m ² , ST ₄ = 470 w / m ² ), and the predetermined value ST ₁ to
Solar radiation intensity as to ST ₄ to the reference (insolation large), it is determined in sunlight the (in solar radiation amount) and solar radiation weakly (insolation small).

The operation of this embodiment will be described below.

When the operating conditions are set and the operation is instructed by operating the switches on the operation panel 62, the air conditioner 10 reads the operating conditions, detects the environmental conditions by the sensors, and calculates the target outlet temperature T _AO. Then, the air-conditioning operation is started based on the calculated target outlet temperature T _AO .

[0054] Incidentally, air conditioning ECU36 sets the target post evaporator temperature T _EO when performing air conditioning of the passenger compartment, after the target evaporator evaporator after the temperature T _E detected by post-evaporator temperature sensor 56 the temperature T _EO
On / off control of the compressor 32 is performed so that

FIG. 6 shows the temperature T after the target evaporator.
The outline of _EO setting is shown. This flowchart is
When the operation of the air conditioner 10 is instructed, it is executed at predetermined time intervals.

In this flowchart, the setting of the suction port switch 76 is read in the first step 100, and then the solar radiation amount ST detected by the solar radiation sensor 54 and the outside air temperature T _O detected by the outside air temperature sensor 50 are read (step 102). , 104).

Thereafter, at step 106, the amount of solar radiation ST
It is determined whether or not there is little, that is, whether or not the solar radiation is weak. If the solar radiation is strong (intensity of solar radiation or during solar radiation), a negative determination is made and the process proceeds to step 108. This step 108
Then, the setting by the suction switch 76 (suction mode)
A solar radiation ST, sets the target post-evaporator temperature based on the outside air temperature T _O. That is, in the case of the outside air introduction mode, the target post-evaporator temperature T _EO is set from the map based on FIGS. 3A and 3B, and in the case of the inside air circulation mode, FIGS. The target post-evaporator temperature T _EO is set from the map based on (D).

On the other hand, when the solar radiation is weak, an affirmative determination is made in step 106 and the routine proceeds to step 110. In step 110, the vehicle speed V detected by the vehicle speed sensor 58 is read.

Thereafter, at step 112, it is determined whether the vehicle speed V is lower than the predetermined speed V ₀ , that is, while the vehicle is running at a speed higher than the predetermined speed V ₀ ,
It is determined whether the possibility that the engine 34 stops in a short time is low, or whether the vehicle is running at a speed lower than the predetermined speed V ₀ and the possibility that the engine stops in a short time is high. I do.

Here, when the vehicle speed V is equal to or lower than the predetermined speed V ₀ , it is estimated that there is a high possibility that the engine 34 will stop, and an affirmative determination is made in step 112 and the process proceeds to step 114. When the vehicle speed V is higher than the predetermined speed V ₀ , it is estimated that the engine 34 does not stop, and
A negative determination is made in step 12, and the process proceeds to step 116.

In step 114, FIG.
From the map based on (C), the suction mode and the amount of solar radiation S
The target post-evaporator temperature T _EO is set based on T and the outside air temperature T _O. Also, in step 116, FIG.
The target post-evaporator temperature T _EO is set from the map based on (B) or FIG. 3 (D).

Accordingly, for example, under the condition that the compressor 32 stops in response to the stop of the engine 34 and the passengers in the passenger compartment are uncomfortable or the windshield glass is easily fogged, the vehicle speed V becomes the predetermined speed V _0. When the temperature falls below, the target post-evaporator temperature T _EO is also lowered. By controlling the compressor 32 based on the target post-evaporator temperature T _EO , the post-evaporator temperature T _E also decreases.

[0063] post-evaporator temperature T _E at this time, since it is to be lower than the temperature after the normal of the evaporator to be comfortable in the passenger compartment, the post-evaporator temperature T _E
Even compressor 32 is stopped in, since still lower temperature T _E after evaporation than normal, the evaporator 22
Even if the air that has passed through the vehicle is blown into the passenger compartment, the occupant does not feel uncomfortable. That is, even if the compressor 32 is stopped together with the engine 34, the interior of the vehicle can be kept in a comfortable air-conditioned state, and the windshield glass does not fog.

As a result, it is not necessary to start the stopped engine for the purpose of maintaining the comfort of the vehicle interior, and the comfort of the vehicle interior can be maintained while maintaining the energy saving effect.

On the other hand, the air conditioner ECU 36 stops the compressor 32 instead of lowering the target post-evaporator temperature T _EO when it is simply estimated from the vehicle speed V that the engine 34 is likely to stop. The target post-evaporator temperature T _EO is reduced only under environmental conditions where comfort is impaired. That is, without lowering the temperature T _EO after target evaporator according to the vehicle speed V when in sunlight little or solar radiation, solar radiation amount ST and the outside air temperature T
_The target post-evaporator temperature T _EO is set based on _O and the blowing mode.

As a result, the load on the engine 34 caused by turning on the compressor 32 unnecessarily can be reduced, and a higher energy saving effect can be obtained. [Second Embodiment] FIG.
1 shows a schematic configuration of a hybrid vehicle 80 provided with an air conditioner 10 applied to the present embodiment. In the second embodiment described below, an example in which the air conditioner 10 is installed in the hybrid vehicle 80 will be described. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals. And description thereof is omitted.

The hybrid vehicle 80 is provided with an electric motor (hereinafter referred to as a “running motor 82”) as a driving source for running, in addition to the engine 34. Engine 3
4 is connected to an engine starter 84, and the engine 3
4. A battery 86 is connected to the engine starting device 84 and the traveling motor 82.

The driving of the engine 34, the engine starting device 84 and the traveling motor 82 is controlled by the engine ECU 64 and the hybrid ECU 88. The engine starting device 84 also has a function of charging the battery 86 by generating power by the driving force of the engine 34.

When the hybrid vehicle 80 stops at an intersection or the like, for example, it has an engine stop function of stopping the engine 34 while the vehicle is stopped. Motor 8
2 is driven. In addition, the driving motor 82 is driven according to the load during driving of the engine 34 to improve the fuel efficiency of the engine 34, that is, to save energy.

The engine ECU 64 is provided with an air conditioner E
When there is a request to turn on the compressor 32 from the CU 36, a magnet switch (not shown) is turned on and the engine 34 is turned on.
Is transmitted to the compressor 32, and if the engine 34 is stopped, the engine 34 is started.

[0071] The air conditioner 10 sets a target outlet air temperature T _AO based on the environmental conditions detected by the set operating conditions and the sensors or the like on the operation panel 62, the target outlet air temperature T _AO and blower level, An air-conditioning operation is performed based on operating conditions such as a blowing mode. Air conditioner 1
0 is the amount of solar radiation S even when provided on the hybrid vehicle 80.
Based on T, the outside air temperature T _O , the suction mode, and the vehicle speed V, the target post-evaporator temperature T _EO is set to perform the air-conditioning operation.

FIG. 8 schematically shows control of the compressor 32 of the air conditioner 10 when the compressor 32 is provided in the hybrid vehicle 80. Incidentally, air conditioning ECU36, when FULL switch 66 of the operation panel 62 shown in FIG. 2 is turned on, as shown in FIG. 9 (A), the post-evaporator temperature T _E is substantially minimum temperature (e.g., 3 ° C.) The compressor 32 is turned on / off so as to be maintained. Further, as shown in FIG. 9 (B), air conditioning ECU36 the vehicle speed V of the hybrid vehicle 80, when more than a predetermined speed (e.g. 10 km / h), the post-evaporator temperature T _E is relatively high temperatures (e.g. 12 ° C.), the temperature difference (T _E ) when turning off the compressor 32 and turning on the compressor 32
Is ON at 25 ° C.) so that the compressor 32 is not turned on more than necessary.

[0073] In other words, when the vehicle stops as described above,
The engine 34 is stopped.
By driving the engine 34 on demand, fuel efficiency can be improved.
Absent. Therefore, by using this example, the engine
34 is not driven, and the fuel efficiency can be improved.

The flowchart shown in FIG. 8 is executed when the ignition switch is turned on. In the first step 130, the air conditioner switch 7 on the operation panel 62 is turned on.
8 is turned on, and the next step 13
In 2, it is confirmed whether or not the FULL switch 66 is turned on. Here, when the air conditioner switch 78 is turned off, a negative determination is made in step 130, and the routine proceeds to step 134, where the compressor 32 is stopped without requesting to turn on the compressor 32.

When the air conditioner switch 78 is turned on,
FULL when the switch 66 is turned on (YES judgment in step 132), the process proceeds to step 136, on / off control of the compressor 32 so as to keep the post-evaporator temperature T _E to a minimum temperature (Fig. 9 (A)
Reference, maximum capacity control). At this time, the compressor 32
When the engine 34 is stopped, the engine ECU 64 starts the engine 34 and drives the compressor 32 in response to the request for turning on the engine 34.

On the other hand, the air conditioner switch 78 is turned on,
In a normal operation state in which the FULL switch 66 is turned off (an affirmative determination in step 130 and a negative determination in step 132), the vehicle speed V is confirmed in step 138. That is, it is determined whether the vehicle speed V is extremely low.

Here, when the vehicle speed V is extremely low (Yes at step 138), the routine proceeds to step 140, where control is performed so that the compressor 32 is turned on to the minimum necessary (relaxation control). That is, on the compressor 32 at post-evaporator temperature T _E shown in FIG. 9 (B) /
OFF control is performed.

On the other hand, when the vehicle speed V of the hybrid vehicle 80 is equal to or higher than the predetermined speed (step 138).
In step 142, the routine proceeds to step 142, where normal control for turning on / off the compressor 32 based on the target post-evaporator temperature T _EO is executed.

At the time of the normal control, as shown in the first embodiment, the target evaporator post-evaporator temperature T _EO is set based on the vehicle speed V in addition to the insolation ST, the outside air temperature T _O and the suction mode. , The target post-evaporator temperature T
On / off control of compressor 32 based on _EO (FIG. 5
(Refer to (A)).

Thus, the vehicle speed V of the hybrid vehicle 80
Is higher than the speed V _O , the target post-evaporator temperature T _EO is set to a temperature at which the compressor 32 can be efficiently driven to keep the vehicle interior comfortable.
When the temperature becomes equal to or less than _O, the target post-evaporator temperature T _EO is reduced in consideration of maintaining the comfort when the engine 34 is stopped.

Therefore, the vehicle speed V of the hybrid vehicle 80
Becomes extremely low, the vehicle stops, and the process proceeds to the relaxation control in step 140, the compressor 32 is not turned on because the temperature of the evaporator 22 is lowered, and the compressor 32 is turned on. Even if it is not performed, the comfort in the vehicle compartment is not impaired, and the antifogging property can be secured.

As described above, the air conditioner 10 is
In addition, even if the compressor 32 is stopped intermittently, the comfort in the vehicle compartment can be maintained and the hybrid vehicle 8
Zero energy savings are not lost.

In this embodiment, the vehicle speed sensor 58 is used as the estimating means.
A throttle sensor for detecting the opening of the throttle valve 4 and a brake switch for detecting whether or not the brake pedal is depressed may be used. The vehicle speed sensor 58
By using the throttle sensor and the brake switch together, the stop of the engine 34 of the vehicle can be more accurately estimated, and the compressor 32 can be efficiently driven.

In the present embodiment, the amount of solar radiation is detected as an environmental condition, and it is determined whether or not the target post-evaporator temperature T _EO should be reduced based on the detection result. A wiper switch, a humidity sensor, or the like may be used as a means for detecting whether or not the indoor comfort is impaired or the windshield glass is likely to be fogged.

That is, when the wiper switch is turned on, the environment is high in humidity, and when the compressor 32 stops and the temperature of the evaporator 22 rises, the dehumidifying ability decreases. This not only impairs the comfort of the vehicle interior but also tends to cause fogging. In such a case, by lowering the temperature of the evaporator 22 before the compressor 32 stops, it is possible to suppress the occurrence of fogging and the like even when the compressor 32 stops.

The present embodiment described above does not limit the configuration of the present invention. The present invention relates to a vehicle having a configuration in which the engine is intermittently stopped so as to save energy, such as a hybrid vehicle or an eco-run vehicle. Of course, the present invention can be applied to general vehicles. That is, even in a vehicle in which the ignition key is turned off and the engine is stopped, immediately after the engine is stopped, the temperature of the evaporator 22 is low. Can be.

[0087]

As described above, according to the present invention, the engine of the vehicle intermittently driven by the estimating means is stopped.
By lowering the temperature after the target evaporator when it is estimated that the temperature of the air passing through the evaporator will not increase even if the compressor stops due to the stop of the engine, comfortable air conditioning in the vehicle interior Can be kept in condition.

In a hybrid vehicle or an eco-run vehicle,
There is no need to start the stopped engine to maintain the comfort of the vehicle interior, and an excellent effect that the comfort of the vehicle interior can be maintained while maintaining the energy saving effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an air conditioner applied to an embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating an example of an operation panel for setting operating conditions of the air conditioner.

3 (A) to 3 (D) are diagrams showing the target post-evaporator temperature with respect to the outside air temperature, respectively. FIG. 3 (A) is the outside air introduction mode when the vehicle speed is equal to or lower than a predetermined value, and FIG. (C) shows a case where the vehicle speed is lower than a predetermined value in the inside air circulation mode, and (D) shows a case where the vehicle speed is higher than the predetermined value in the inside air circulation mode.

FIGS. 4A and 3B are FIGS. 3A to 3
It is a diagram which shows the target after-evaporator temperature with respect to the outside air temperature according to the vehicle speed based on (D), (A) is the case of the insolation weak in the outside air introduction mode, (B) is the case of the insolation weak in the inside air circulation mode. Is shown.

FIG. 5A is a diagram showing ON / OFF of a compressor based on a temperature after an evaporator, and FIG. 5B is a diagram showing a stage of a solar radiation amount with respect to a detection value of a solar radiation sensor.

FIG. 6 is a flowchart illustrating an outline of setting of a target post-evaporator temperature according to the first embodiment.

FIG. 7 is a schematic configuration diagram of a hybrid vehicle according to a second embodiment.

FIG. 8 is a flowchart showing an outline of a compressor on / off control based on a post-evaporator temperature according to a second embodiment.

FIG. 9A is a diagram showing ON / OFF of a compressor based on a temperature after an evaporator at the time of maximum capacity control,
(B) is a diagram showing ON / OFF of a compressor based on a temperature after an evaporator at the time of relaxation control.

[Explanation of symbols]

Reference Signs List 10 air conditioner (vehicle air conditioner) 22 evaporator 32 compressor 34 engine 36 air conditioner ECU (evaporator temperature setting means, control means, estimating means, evaporator temperature change means) 50 outside air temperature sensor 54 solar radiation sensor 56 evaporator temperature sensor (temperature) Detecting means) 58 Vehicle speed sensor (estimating means) 62 Operation panel 64 Engine ECU 80 Hybrid vehicle

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yuji Takeo 1-1-1, Showa-cho, Kariya-shi, Aichi Pref. Denso Co., Ltd. (56) References JP-A-7-172158 (JP, A) JP-A-10-84603 (JP, A) JP-A-4-283118 (JP, A) JP-A-3-86620 (JP, A) JP-A-61-201919 (JP, U) JP-A-57-168408 (JP, U) 57-113221 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60H 1/32

Claims (3)

(57) [Claims] 1. An air conditioner for a vehicle that cools air blown into a vehicle cabin by a refrigerating cycle including a compressor and an evaporator that are rotated by an engine of a vehicle that is intermittently operated , the temperature of the air passing through the evaporator. Temperature detecting means for detecting the post-evaporator temperature, evaporator temperature setting means for setting the target post-evaporator temperature based on the environmental conditions of the vehicle detected by the environmental condition detecting means, and the temperature detected by the temperature detecting means is Control means for controlling the drive of the compressor so that the target evaporator temperature set by the evaporator post-temperature setting means, and estimating means for estimating whether or not the engine driving the compressor is before the stop, Before the estimating means stops the engine in intermittent operation,
And a post-evaporator temperature changing means for changing the target post-evaporator temperature set by the post-evaporator temperature setting means when it is estimated that the post-evaporator temperature setting means is lower. Wherein said estimating means includes a vehicle speed sensor, when the speed of the vehicle detected by the vehicle speed sensor reaches a predetermined or less, according to claim 1 wherein said engine and estimates to be stopped for a vehicle air-conditioning system. 3. The method according to claim 1, further comprising: a solar radiation sensor for detecting an amount of solar radiation as the environmental condition detecting means. The vehicle air conditioner according to claim 1 or 2, wherein the determination is performed.