JP2001310620A - Air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the compatibility of restraint on the generation of a smell by the halting of a compressor with an extension of the stopping time of an engine (4) in case of the stop of a vehicle in an air conditioner for the vehicle, mounted on the vehicle exercising control over the stop of the engine (4) at least in case of the stop of the vehicle and having the compressor driven by the engine (4). SOLUTION: The operation of the compressor 1 is controlled according to a detection signal from a temperature detecting means 32 for detecting the temperature of an evaporator 9 in order to control the temperature of the evaporator 9. In case of the stop of the vehicle, the engine (4) is continuously in a halt condition until the temperature of the evaporator 9 becomes slightly higher than in case of travelling. Additionally, the temperature of the evaporator 9 is lowered to a prescribed temperature or less when the condition just before the stop of the vehicle is judged during the travelling.

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 mounted on a vehicle having a function of giving priority to stopping a vehicle engine over driving a refrigeration cycle when the vehicle is stopped.

[0002]

2. Description of the Related Art In recent years, for the purpose of environmental protection, vehicles (eco-run vehicles, hybrid vehicles, etc.) that automatically stop the engine when the vehicle is stopped (when engine power is not required) such as when waiting for a traffic light have been put to practical use. In the future, the number of vehicles that stop the engine when the vehicle stops will tend to increase.

In a vehicle air conditioner, the compressor of a refrigeration cycle is driven by a vehicle engine.
In the power saving (fuel consumption priority) mode provided by the economy switch as in Japanese Patent Publication No. 44, the vehicle stops when waiting for a traffic light, etc., and whenever the engine is stopped, the compressor also stops and the evaporator temperature rises. I do. When the condensed water on the evaporator surface dries out in the evaporator temperature rising process, the odor component dissolved in the condensed water separates from the condensed water and blows out into the vehicle cabin together with the blast air, causing discomfort to the occupants. .

Therefore, in Japanese Patent Application Laid-Open No. 11-198644, a compressor stop time capable of suppressing generation of an odor is calculated based on the condition of the evaporator suction air when the compressor is stopped due to a stop, and the elapsed time after the compressor is stopped is calculated. When the time exceeds the calculated time, there has been proposed a configuration in which the vehicle engine is restarted to return the compressor to the operating state even when the vehicle is stopped.

[0005]

The inventors of the present invention have conducted an experimental study on such a conventional apparatus, and as a result, it has been found that the following problems newly occur.

First, the control of the evaporator temperature in the vehicle air conditioner will be described. Since the compressor is driven by the vehicle engine, the electromagnetic clutch between the compressor and the vehicle engine is intermittently connected. The evaporator temperature is controlled to be maintained at a predetermined target temperature by interrupting the operation. Also, in part, a variable displacement compressor is used as a compressor, and the discharge capacity of the compressor is changed to adjust the flow rate of refrigerant discharged from the compressor so that the evaporator temperature is maintained at a predetermined target temperature. Some control is also known.

Here, in order to save the power of the vehicle engine, which is the driving source of the compressor, the target temperature of the evaporator temperature is increased and the operation rate of the intermittent operation of the compressor [compressor operation time / (compressor operation time) It is effective to decrease the operation time + compressor stop time)] or to lengthen the time of the small capacity operation state of the compressor.

Therefore, in order to save the power of the vehicle engine,
If the refrigeration cycle is operated while the target temperature of the evaporator temperature is raised to about 18 ° C. during running of the vehicle, the amount of condensed water generated in the evaporator decreases. Therefore, when the vehicle shifts from this state when the vehicle stops and the compressor is stopped, the condensed water on the evaporator surface dries out in a short time, and the air blown into the vehicle cabin emits an odor.

Therefore, in order to suppress odor, it is necessary to restart the vehicle engine in a short time after stopping the vehicle to operate the compressor. This violates the basic concept of eco-run vehicles in which the engine is stopped when the vehicle stops, and impairs the power-saving (fuel-saving) effect of the eco-run vehicles.

[0010] The present invention has been made in view of the above points,
In a vehicle air conditioner that is mounted on a vehicle that controls the engine 4 to stop at least when the vehicle is stopped and the compressor is driven by the engine, both suppression of generation of odor due to the stop of the compressor and extension of the engine stop time when the vehicle is stopped are compatible. The purpose is to improve.

[0011]

According to the first aspect of the present invention, when the vehicle is stopped, the temperature of the evaporator (9) is increased until the temperature of the evaporator (9) becomes higher than when the vehicle is running. In the vehicle air conditioner that continues to stop in (1), the temperature of the evaporator (9) is reduced to a predetermined temperature or less when the state immediately before the stop is determined during running of the vehicle.

According to this, when the vehicle is running, the evaporator (9)
Even when the power saving control of the vehicle engine (4) is performed by controlling the temperature of the evaporator (9) to be higher, the temperature of the evaporator (9) is reduced to a predetermined temperature or less immediately before the vehicle stops, and the evaporator (9) is controlled. The amount of condensed water can be increased.

As a result, when controlling to stop the engine (4) when the vehicle is stopped, after the engine (4) is stopped (ie, after the compressor (1) is stopped), condensed water on the evaporator surface is completely dried. You can extend the time until. Thereby, the stop time of the engine (4) at the time of stopping the vehicle can be extended while suppressing the generation of odor due to the stop of the compressor.

More specifically, as in the second aspect of the present invention, the target evaporator temperature on the low temperature side for preventing frost formation on the evaporator (9) during running of the vehicle, and the temperature of the engine (4). When controlling the temperature of the evaporator (9) based on the target evaporator temperature on the high temperature side for power saving, the predetermined temperature is set to a temperature lower than the target evaporator temperature on the high temperature side.

[0015] Further, as in the third aspect of the present invention, first determining means (S220) for determining a first target evaporator temperature necessary for controlling the temperature of air blown into the vehicle cabin; Second determining means (S230) for determining a second target evaporator temperature required for maintaining the humidity in the comfortable range, and a third determining means for determining a third target evaporator temperature required for preventing fogging of the window glass. Determining means (S240) and fourth determining means (S250) for finally determining the lowest temperature among the first to third target evaporator temperatures as the target evaporator temperature during running; When the time target evaporator temperature is higher than the predetermined temperature and the state immediately before the stop is determined, the temperature of the evaporator (9) may be reduced to the predetermined temperature or lower.

According to the third aspect of the present invention, the temperature of the evaporator (9) during running of the vehicle is adjusted to the minimum temperature required for controlling the temperature of air blown into the vehicle interior, controlling the humidity in the vehicle interior, and preventing fogging of the window glass. Control to temperature.

By the way, if the humidity in the air-conditioned space is maintained in a comfortable range, the user can feel the comfort without cooling. Therefore, in a season in which the outside air is in a low-humidity atmosphere, such as in the middle of spring and autumn, the second determining means (S23)
The second target evaporator temperature for humidity control according to 0) is maintained at a higher temperature. In such an intermediate period, the outside air temperature is in the intermediate temperature range, and the other first and third target evaporator temperatures can be both set to higher temperatures. Alternatively, the power saving effect of the vehicle engine (4) can be improved by the small-capacity driving.

In addition, even if the power saving control is performed while the target evaporator temperature is set to a higher temperature during running as described above, the target evaporator temperature is forcibly reduced when it is determined immediately before the vehicle stops. The same operation and effect as described above can be exhibited.

As in the fourth aspect of the present invention, the state immediately before stopping can be determined by a vehicle driving signal including at least a vehicle speed signal.

When the acceleration state of the vehicle is determined after determining the state immediately before the vehicle stops, the reduction of the temperature of the evaporator (9) to a predetermined temperature or less is canceled. You may.

According to this, even after judging the state immediately before stopping, the temperature of the evaporator (9) is returned to the original high temperature by the judgment of the acceleration state of the vehicle, and the engine (4) The power saving effect can be enhanced.

According to a sixth aspect of the present invention, there is provided a signal gradual change means for gradually changing and outputting a signal indicating the actual acceleration state of the vehicle with time, and an output signal of the signal gradual change means is provided. May be used to determine the acceleration state.

According to this, when the vehicle is in an acceleration state for a very short time, the acceleration state of the vehicle is not determined, and the reduction of the temperature of the evaporator (9) to a predetermined temperature or lower can be continued as it is.

The reference numerals in parentheses of the above means indicate the correspondence with specific means described in the embodiments described later.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is an overall configuration diagram of a first embodiment, and a refrigeration cycle R of a vehicle air conditioner is provided with a compressor 1 for sucking, compressing and discharging refrigerant. Have been. The compressor 1 has an electromagnetic clutch 2 for interrupting power, and the power of the vehicle engine 4 is transmitted to the compressor 1 via the electromagnetic clutch 2 and the belt 3. Electromagnetic clutch 2
The energization of the compressor 1 is interrupted by the air-conditioning electronic control device 5, and the operation of the compressor 1 is interrupted by the intermittent energization of the electromagnetic clutch 2.

The high-temperature, high-pressure superheated gas refrigerant discharged from the compressor 1 flows into the condenser 6, where it exchanges heat with the outside air blown by a cooling fan (not shown) to cool and condense the refrigerant. The refrigerant condensed in the condenser 6 then flows into the receiver 7, where gas and liquid of the refrigerant are separated inside the receiver 7,
Excess refrigerant (liquid refrigerant) in the refrigeration cycle R is stored in the receiver 7.

The liquid refrigerant from the receiver 7 is decompressed to a low pressure by an expansion valve (decompression means) 8, and enters a low-pressure gas-liquid two-phase state. The expansion valve 8 is a temperature-type expansion valve having a temperature sensing portion 8a for sensing the temperature of the refrigerant at the outlet of the evaporator 9. This expansion valve 8
Flows into the evaporator (cooling heat exchanger) 9. The evaporator 9 is installed in an air conditioning case 10 of a vehicle air conditioner, and the 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 connected to the suction side of the compressor 1 and forms a closed circuit by the above-mentioned 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 drive motor 13. An inside / outside air switching box 14 is arranged on the suction side of the blower fan 12, and an inside / outside air switching door 14a in the inside / outside air switching box 14 opens and closes an outside air inlet 14b and an inside air inlet 14c.
Thereby, outside air (vehicle outside air) is stored in the inside / outside air switching box 14.
Alternatively, the inside air (vehicle interior air) is switched and introduced. The inside / outside air switching door 14a is an electric drive unit 14 including a servomotor.
Driven by e.

In the ventilation system of the air conditioner, the air-conditioning unit 15 disposed downstream of the blower 11 is usually disposed at the center position in the vehicle width direction inside the instrument panel at the front of the passenger compartment. It is arranged offset to the passenger seat side with respect to 15 units.

An air mix door 19 is arranged in the air conditioning case 10 downstream of the evaporator 9. On the downstream side of the air mix door 19, a hot water heater core (heating heat exchanger) 20 for heating air using hot water (cooling water) of the vehicle engine 4 as a heat source is installed. On the side (upper part) of the hot water type heater core 20, a bypass passage 21 for flowing air while bypassing the hot water type heater core 20 is formed.

The air mix door 19 is a rotatable plate-like door, and is driven by an electric drive device 22 composed of a servomotor. The air mix door 19 adjusts the ratio of the amount of hot air passing through the hot water heater core 20 and the amount of cool air passing through the bypass passage 21. By adjusting the ratio of the amount of cool and hot air, the air blown into the vehicle compartment is adjusted. Adjust the temperature. Therefore, in this example, the air mix door 19
This constitutes a means for adjusting the temperature of the air blown into the vehicle interior.

A hot air passage 23 extending upward from the lower side is formed downstream of the hot water heater core 20, and the hot air from the hot air passage 23 and the cool air from the bypass passage 21 are mixed in the air mixing section 24. Thus, air at a desired temperature can be produced.

Further, in the air-conditioning case 10, a blowing mode switching unit is provided downstream of the air mixing unit 24. That is, a defroster opening 25 is formed in the upper surface of the air-conditioning case 10, and the defroster opening 25 blows air to the inner surface of the vehicle windshield through a defroster duct (not shown). The defroster opening 25 is
It is opened and closed by a rotatable plate-shaped defroster door 26.

A face opening 27 is formed on the upper surface of the air-conditioning case 10 at a position rearward of the vehicle from the defroster opening 25, and the face opening 27 is formed through a face duct (not shown). It blows air toward. The face opening 27 is opened and closed by a rotatable plate-like face door 28.

In the air-conditioning case 10, a foot opening 29 is formed below the face opening 27,
The foot opening 29 blows air toward the feet of the occupant of the passenger compartment through a foot duct (not shown). The foot opening 29 is a rotatable plate-like foot door 3.
It is opened and closed by 0.

The above-mentioned blow mode doors 26, 28, 30
Is connected to a common link mechanism (not shown), and an electric drive device 31 composed of a servomotor is connected via the link mechanism.
Driven by

Next, an outline of the electric control unit according to the present embodiment will be described. As the temperature sensor of the evaporator 9, a temperature sensor 32 composed of a thermistor is provided. The temperature sensor 32 is disposed in the air conditioning case 10 at a position immediately after the air is blown out of the evaporator 9 and detects the evaporator blowout temperature Te.

The air-conditioning electronic control unit 5 includes, in addition to the temperature sensor 32, a well-known sensor 33 for detecting an internal temperature Tr, an external temperature Tam, a solar radiation amount Ts, a hot water temperature Tw, and the like for air-conditioning control. To 36, a detection signal is input. Also,
The air-conditioning control panel 37 installed near the instrument panel in the vehicle compartment has operation switches 37a to 37e manually operated by the occupants.
The operation signals of the operation switches 37 a to 37 e are also input to the air-conditioning electronic control device 5.

As the operation switch, specifically, a temperature setting switch 37 for generating a temperature setting signal Tset
a, an air volume switch 37b for generating an air volume switching signal, a blowing mode switch 37c for generating a blowing mode signal, an inside / outside air switching switch 37d for generating an inside / outside air switching signal, an air conditioner switch 37e, an economy switch 37f, and the like.

The blow mode switch 37c is used to manually switch between the face mode, the foot mode, the bi-level mode, the foot differential mode, and the defroster mode. The air conditioner switch 37e generates an on / off signal for the compressor 1 and generates a signal for setting the target temperature TEO of the evaporator 9 to a lower temperature for preventing frost. The economy switch 37f generates an on / off signal for the compressor 1 and sets a target temperature T for the evaporator 9.
A signal is generated to raise EO from a lower temperature to prevent frost to a higher temperature.

The air conditioning electronic control unit 5 is connected to an engine electronic control unit 38. The engine air conditioning electronic control unit 5 sends the air conditioning electronic control unit 5 a rotation speed signal and a vehicle speed signal of the vehicle engine 4. Is entered.

As is well known, the engine electronic control unit 38 integrates a fuel injection amount, an ignition timing, and the like to the vehicle engine 4 based on a signal from a group of sensors (not shown) for detecting an operation state and the like of the vehicle engine 4. It is to control it. Further, in an eco-run vehicle and a hybrid vehicle to which the present invention is applied, a rotation speed signal of the vehicle engine 4, a vehicle speed signal,
When the stop state is determined based on a brake signal or the like, the engine electronic control unit 38 automatically stops the vehicle engine 4 by shutting off the power supply of the ignition device, stopping the fuel injection, and the like.

After the engine is stopped, when the vehicle is shifted from the stopped state to the start state by the driving operation of the driver, the engine electronic control unit 38 determines the start state of the vehicle based on an accelerator signal or the like, and the vehicle engine is controlled. Start 4 automatically. The air-conditioning electronic control unit 5 outputs an engine restart request signal based on, for example, an increase in the evaporator outlet temperature Te after the vehicle engine 4 is stopped.

The electronic control unit 5 for air conditioning and the electronic control unit 24 for the engine are composed of a well-known microcomputer including a CPU, a ROM, a RAM, and the like, and peripheral circuits thereof. The air-conditioning electronic control unit 5 includes an engine control signal output unit that outputs a stop permission / stop prohibition signal of the vehicle engine 4 and a signal of a restart request after the engine is stopped, a compressor intermittent control unit using the electromagnetic clutch 2, and inside / outside air. Inside / outside air suction control unit by switching door 14a, air volume control unit of blower 11, temperature control unit by air mix door 19, outlet 2
It has a blowout mode control unit by switching between 5, 27, and 29, and the like.

Next, the operation of the present embodiment in the above configuration will be described. The flowchart of FIG. 2 shows the outline of the control processing executed by the microcomputer of the air-conditioning electronic control device 5, and the control routine of FIG.
Starts when the ignition switch is turned on and power is supplied to the control device 5.

First, in step S1, flags, timers and the like 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 signal of the vehicle environment state, that is, a detection signal from the sensors 32 to 36, a vehicle operation signal from the engine electronic control unit 38, and the like are read.

Subsequently, in step S4, a target blowing temperature TAO of the conditioned air blown into the vehicle compartment is calculated. The target outlet temperature TAO is set in the vehicle interior by a temperature setting switch 37a.
Is a blowout temperature required to maintain the set temperature Tset of the above formula, and is calculated based on the following mathematical expression 1.

[0048]

## EQU1 ## TAO = Kset × Tset−Kr × Tr−Kam × Tam
−Ks × Ts + C, where Tr: internal temperature detected by the internal air sensor 33 Tam: external temperature detected by the external air sensor 34 Ts: solar radiation detected by the solar radiation sensor 35 Kset, Kr, Kam, Ks: control gain C : Correction Constant Next, in step S5, a target air blowing amount of the air blown by the blower 11, that is, a blower voltage Ve which is an applied voltage of the blower driving motor 13 is determined based on the TAO. The method of 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 low temperature side (maximum cooling side) of the TAO, and the blower voltage is set in the intermediate temperature range of the TAO. Voltage (target air volume)
Reduce Ve.

Next, the inside / outside air mode is determined in step S6. In the inside / outside air mode, for example, the inside air mode is set when the inside temperature Tr is higher than or equal to a predetermined temperature with respect to the set temperature Tset and is significantly higher (at the time of a high cooling load). Alternatively, as the TAO increases from the low temperature side to the high temperature side, the entire inside air mode → the inside / outside air mixing mode →
The setting may be switched to the all outside air mode.

Next, in step S7, the blowing mode is determined according to the TAO. As is well known, as the TAO rises from the low-temperature side to the high-temperature side, the blowing mode is switched and set in the face mode → the bi-level mode → the foot mode.

Next, in step S8, the target opening degree SW of the air mix door 19 is set to the above TAO and the evaporator blowout temperature T.
e, and the hot water temperature Tw is calculated by the following equation (2).

[0052]

## EQU2 ## SW = [(TAO-Te) / (Tw-Te)]
× 100 (%) Here, the target opening degree SW of the air mix door 19 is 0% at the maximum cooling position (solid line position in FIG. 1) of the air mix door 19, and the maximum heating position of the air mix door 19 (FIG. 1).
(Dashed-dotted line position) is 100%.

Next, the routine proceeds to step S9, where the intermittent operation (ON-OFF) of the compressor operation is determined. In other words, the target evaporator temperature TEO is compared with the evaporator blowout temperature Te detected by the temperature sensor 32 to determine the voltage Vc applied to the electromagnetic clutch 2 and to determine the intermittent operation (ON-OFF) of the compressor operation. I do. Details of step S9 will be described later with reference to FIG.

Next, the process proceeds to step S10, and the control state determined in steps S5 to S9 is obtained.
Various actuator units (2, 13, 14e, 22, 3
A control signal is output to 1). When the elapse of the control cycle τ is determined in the next step S11, the process returns to step S2.

FIG. 3 shows a specific example of a method of determining the intermittent operation (ON-OFF) of the compressor operation in step S9. First, in step S100, the air conditioner switch 37 is set.
e is ON or not, and the result of this determination is Y
In the case of ES, the process proceeds to step S110, and a target evaporator temperature TEO1 for preventing frost (for maximum cooling) is determined. Specifically, TE is set to a minimum temperature range (usually in a range of about 3 ° C. to 4 ° C.) in which frost (frost formation) of the evaporator 9 can be prevented.
Determine O1.

If the result of the determination in step S100 is NO
In the case of, it is determined in step S120 whether or not the economy switch 37f is ON. If the result of this determination is NO, an OFF signal for the compressor 1 is output in step S130.

On the other hand, when the economy switch 37f is ON, the process proceeds to step S140, and it is determined whether the vehicle is at a stop. The determination at the time of stopping can be performed by various methods. In this example, the vehicle speed is set to the first predetermined value (for example, 1
0 km / h) or less is determined as a stop.

When the vehicle speed is higher than the first predetermined value, that is, when the vehicle is traveling, the process proceeds to step S150, and the target evaporator temperature TEO2 for power saving control is determined. TEO2 for power saving control is the target evaporator temperature TEO1 for preventing frost.
A higher temperature is used to reduce the compressor operating rate, thereby achieving a power saving of the vehicle engine 4. Specifically, TEO2 for power saving control is set to a temperature of about 14 to 15 ° C.

Next, in step S160, it is determined whether the target evaporator temperature TEO (TEO1 or TEO2) is higher than a predetermined value Tx. Here, the predetermined value Tx is lower than the target evaporator temperature TEO2 for power saving control and higher than the target evaporator temperature TEO1 for preventing frost (for example, 11 ° C.). Therefore, TEO for preventing frost
When 1 is set, the determination in step S160 is N
The result is O, the process proceeds to step S170, and TEO1 is held as it is.

On the other hand, when the target evaporator temperature TEO2 for power saving control is set, the determination in step S160 is YES, and the process proceeds to step S180 to determine whether the vehicle is in a state immediately before stopping. This determination can also be made by various methods. In this example, the vehicle speed is lower than a second predetermined value (for example, 20 km / h) higher than the first predetermined value (for example, 10 km / h), and In addition, when the braking operation is performed by the occupant and the brake signal is ON, that is, the state immediately before stopping can be determined based on the AND condition between the low vehicle speed state and the braking state.

When the vehicle is not in the state immediately before stopping, the process proceeds to step S170, and the target evaporator temperature TEO2 for power saving control is maintained as it is. On the other hand, when the vehicle is in the state immediately before stopping, the process proceeds to step S190, and the target evaporator temperature TEO2 for power saving control is set to the predetermined temperature Tx (= 1).
1 ° C).

If it is determined in step S140 that the vehicle has stopped, the flow advances to step S200 to determine the target evaporator temperature TEO3 for stopping. The target evaporator temperature TEO3 for stopping is set to the target evaporator temperature TEO for power saving control in order to give priority to stopping the engine over the air conditioning (cooling) function.
Set temperature higher than 2. Specifically, the compressor ON-side target temperature of TEO3 for stopping is set to about 23 ° C.

In step S 210, the target evaporator temperatures TEO 1, TEO 2, TEO 3 determined in steps S 170, S 190, and S 200 are compared with the actual evaporator outlet temperature Te detected by the temperature sensor 32. , ON and OFF of the compressor 1 are determined.

Here, Tz shown in the map in step S210 is a hysteresis width for preventing the intermittent hunting of the compressor 1, and each target evaporator temperature TEO1, TEO
O2, TEO3 compressor ON side target temperature a and compressor OF
This is a difference from the F-side target temperature b. In the case of TEO1 and TEO2, the control is performed when the vehicle is running, and the compressor 1 can be intermittently controlled by the electromagnetic clutch 2. Therefore, the value is usually set to a small value such as Tz = 1 ° C.

On the other hand, in the case of TEO3, the control is performed when the vehicle is stopped, and the engine 4 is turned ON and OFF. Therefore, Tz is increased to about 10 ° C., and the frequent ON and OFF of the engine 4 is suppressed. I do. Specifically, when the compressor ON-side target temperature a of TEO3 is set to 23 ° C. as described above, the compressor OFF-side target temperature b of TEO3 is set to about 12 ° C.

By the way, based on the target evaporator temperature TEO2 for power saving control during running of the vehicle, the evaporator outlet temperature Te
Is controlled to a higher temperature, the dehumidifying ability of the evaporator 9 is reduced and the amount of condensed water retained in the evaporator 9 is reduced. However, according to the first embodiment, the state immediately before stopping Is determined, in step S190, the target evaporator temperature TEO2 for power saving control is forcibly set to the predetermined temperature Tx (= 11).
° C).

As a result, the dehumidifying capacity of the evaporator 9 can be increased immediately before the vehicle stops, and the amount of condensed water retained in the evaporator 9 can be increased in advance. Therefore, the target evaporator temperature TEO for stopping
Even if the compressor ON-side target temperature 3 of 3 is set to a temperature (for example, 23 ° C.) higher than the target evaporator temperature TEO2 for power saving control, it is possible to prevent the condensed water on the surface of the evaporator 9 from drying out. As a result, it is possible to achieve both suppression of the generation of odor from the air blown into the vehicle compartment when the vehicle is stopped and prolonging the stop time of the engine 4 (improving fuel economy).

In the first embodiment, the case where the target evaporator temperature TEO2 for power saving control is fixed to a constant value has been described as an example. However, as shown in FIG. It may be corrected. That is, if the outside air temperature is 25
In the high temperature range exceeding ℃, the TEO2 is corrected to the low temperature side according to the rise of the outside air temperature to secure the cooling capacity, and in the low temperature range where the outside air temperature falls below 10 ℃, the dehumidification capacity to prevent the fogging of the window glass In order to secure the TE,
O2 may be corrected to the low temperature side.

In the first embodiment, the predetermined temperature T
Although the case where x is fixed to a constant value has been described as an example, similarly to the target evaporator temperature TEO2 for power saving control, the predetermined temperature Tx also changes according to the rise in outside air temperature in a high temperature range and the fall in outside air temperature in a low temperature range. May be corrected to the low temperature side.

(Second Embodiment) FIG. 5 is a flowchart showing the control according to the second embodiment. In FIG. 5, step S140 and steps S160 to S210 are shown.
Is the same process as in FIG. 3, and a description thereof will be omitted.

In the second embodiment, the target evaporator temperature TEO for the intermittent control of the compressor 1 is determined based on a concept different from that of the first embodiment. That is, if the relative humidity is in a comfortable area (usually, a wide range of about 25 to 65% RH), the user of the air-conditioned space performs cooling (cooling and dehumidification) by the evaporator 9.
It is known that comfort is felt over a relatively wide temperature range without action, that is, without operation of the compressor 1.

Therefore, in the second embodiment, a humidity sensor for detecting the relative humidity in the passenger compartment is added as an air conditioning control sensor, and the relative humidity in the passenger compartment is maintained near the upper limit of the comfortable area (for example, near 60%). Target evaporator temperature T
Determine EO. As a result, the operation rate of the compressor 1 is reduced, and the power saving effect of the vehicle engine 4 is improved. And
In the determination of the target evaporator temperature TEO based on such a concept, the TEO reduction control immediately before the stop described in the first embodiment is further combined.

The humidity sensor is provided at an appropriate place in the vehicle interior,
For example, the humidity sensor is installed around the instrument panel. If the humidity sensor is integrally formed with the inside air sensor 33, the humidity sensor can be integrated with the inside air sensor 33 and attached to the vehicle body at one time, which is convenient. The detection signal of the humidity sensor is input to the control device 5 in the same manner as the sensors 32 to 36 described above.

Next, the control according to the second embodiment will be described in detail with reference to FIG.
From 0, the process proceeds to step S220, and a target evaporator temperature TEO4 for room temperature control determined from the target blow-out temperature TAO calculated in step S4 of FIG. 2 is determined. This TEO4 is determined in order to obtain the evaporator temperature necessary for controlling the temperature inside the vehicle. Therefore, TEO4 is determined to decrease with a decrease in TAO as illustrated in the map of FIG.

Next, in step S230, a target evaporator temperature TEO5 for controlling the interior of the vehicle to a comfortable humidity range is determined. The humidity control TEO 5 is determined so that the vehicle interior relative humidity detected by the humidity sensor is maintained near the target relative humidity (for example, around 60%). More specifically, As illustrated in the map of FIG. 7, when the vehicle interior relative humidity exceeds 60%, the TEO5 becomes a lower temperature T1 (for example, 11 ° C.), and increases when the vehicle interior relative humidity is less than 50%. Temperature T2 (for example, 18 ° C.). As described above, by switching the TEO 5 between two levels in accordance with the actual relative humidity of the vehicle interior, the relative humidity of the vehicle interior can be maintained near the target relative humidity (for example, around 60%).

Next, at step S240, a target evaporator temperature TEO6 for anti-fog control of the vehicle window glass is determined. Here, the factors of the fogging of the vehicle window glass are roughly divided into the temperature of the window glass and the humidity of the air in the vehicle interior. That is, the lower the temperature of the window glass and the higher the humidity of the vehicle interior air, the more easily the window glass becomes cloudy.

Therefore, in step S240, as illustrated in the map of FIG. 8, as the temperature of the window glass decreases and the humidity of the vehicle interior air increases, TE
O6 is determined to decrease. More specifically, T is determined based on the temperature of the window glass and the humidity of the vehicle interior air so that the relative humidity near the inner surface of the window glass is maintained at about 90%.
EO6 is determined.

The temperature of the window glass is the outside temperature Tam,
It can be calculated (estimated) based on the vehicle speed, the defroster outlet temperature, the internal temperature Tr, and the like.

Next, in step S250, the above 3
The lowest temperature among the target evaporator temperatures TEO4 to TEO6 is finally determined as the target evaporator temperature TEO during traveling. At times other than immediately before stopping the vehicle, the target evaporator temperature TEO during the traveling is maintained as it is in step S170, and the intermittent operation of the compressor 1 is determined based on the target evaporator temperature TEO during the traveling in step S210.

In the season in which the outside air is in a low humidity atmosphere, such as in the middle of spring and autumn, the target evaporator temperature T for controlling the vehicle interior humidity is used.
EO5 is normally maintained at the higher temperature T2 in FIG. Further, in such an intermediate period, the outside air temperature is in the intermediate temperature range, and the other two target evaporator temperatures TEO6 are both high. Therefore, the operating rate of the compressor 1 is reduced to save the vehicle engine 4. The power effect can be improved.

During power travel, such power saving control (for example,
Even if TEO = 18 ° C.), if it is determined immediately before the stop in step S180, the process proceeds to step S190 and TE
O = Tx (11 ° C.) and evaporator 9 immediately before stopping
And the amount of condensed water retained in the evaporator 9 can be increased in advance.

Accordingly, in the second embodiment, as in the first embodiment, both the effect of suppressing the generation of odor from the air blown into the vehicle interior when the vehicle is stopped and the fuel saving effect by extending the stop time of the engine 4 are achieved. it can.

(Third Embodiment) In the third embodiment, when the acceleration state of the vehicle is determined after determining the state immediately before stopping in the first and second embodiments, the predetermined temperature Tx of the target evaporator temperature is determined. Cancel the reduction to, and
The target evaporator temperature is returned to the running evaporator temperature TEO. Here, the acceleration state of the vehicle can be determined based on an operation signal of an accelerator pedal, an acceleration signal of a vehicle speed, and the like.

According to the third embodiment, the temperature of the evaporator 9 is returned to the original high temperature by the determination of the acceleration state of the vehicle even after the state immediately before the stop is determined, thereby saving the engine 4. Power effect can be exhibited.

In the third embodiment, there is provided a signal gradual change means for gradually changing and outputting a signal indicating the actual acceleration state of the vehicle with time, and the acceleration based on the output signal of the signal gradual change means is provided. The state may be determined. Here, as a specific example of the signal gradual change means, there is a time constant processing means for changing the output exponentially with respect to time when the input signal changes.

When the acceleration state is determined based on the output signal of the signal gradual change means as described above, the acceleration state of the vehicle is not determined when the acceleration state is extremely short, and the temperature of the evaporator 9 is not higher than a predetermined temperature. Can be continued as it is.

(Fourth Embodiment) In the first and second embodiments, the vehicle speed is constant (for example, 20 km / h).
When the braking signal is ON at a lower speed and the occupant performs the braking operation, that is, the state immediately before the stop is determined based on the AND condition between the low vehicle speed state and the braking state, In the fourth embodiment, the state immediately before stopping is determined based on the AND condition that the vehicle speed is lower than a certain vehicle speed and the deceleration rate is a predetermined value (for example, 0.5 m / s ² ) or higher.

(Other Embodiments) In the above embodiment, the case where the temperature sensor 32 for detecting the evaporator air temperature Te is used as the temperature sensor for detecting the evaporator temperature has been described. It is possible to use a temperature sensor for detecting the evaporator fin temperature or the like as the temperature sensor for detecting the temperature.

In the above-described embodiment, an example in which the present invention is applied to an eco-run vehicle in which the vehicle engine 4 is stopped when the vehicle is stopped has been described. However, both the vehicle engine and the traveling electric motor are mounted, and the vehicle engine 4 is stopped when the vehicle is stopped. The present invention may be applied to a hybrid vehicle that stops the operation.

Further, in the above embodiment, the example in which the state immediately before the stop is determined by the air-conditioning control device 5 has been described. It may be made to communicate with the control device 5 for use. Similarly, in the case of a hybrid vehicle, a state immediately before stopping is determined by a hybrid control device that controls the rotation speed of the traveling electric motor, and the determination result is communicated to the air conditioning control device 5. Good.

[Brief description of the drawings]

FIG. 1 is an overall system diagram of a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating an outline of the entire air conditioning control according to the first embodiment.

FIG. 3 is a flowchart illustrating a main part of air conditioning control according to the first embodiment.

FIG. 4 is a characteristic diagram of a target evaporator temperature according to the first embodiment.

FIG. 5 is a flowchart showing a main part of air conditioning control according to a second embodiment.

FIG. 6 is a characteristic diagram of a target evaporator temperature for room temperature control according to a second embodiment.

FIG. 7 is a characteristic diagram of a target evaporator temperature for humidity control according to a second embodiment.

FIG. 8 is a characteristic diagram of a target evaporator temperature for window glass anti-fog according to a second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Compressor, 4 ... Vehicle engine, 9 ... Evaporator, 32 ... Evaporator temperature sensor.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroki Nakamura 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside Denso Corporation (72) Inventor Yuji 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Denso Corporation (72) Inventor Mitsuyo Omura 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside Denso Corporation (72) Inventor Eiji Takahashi 1-1-1, Showa-cho, Kariya City, Aichi Prefecture Inside Denso Corporation

Claims (6)

[Claims] An air conditioner mounted on a vehicle that controls to stop an engine (4) at least when the vehicle is stopped, comprising: an evaporator (9) for cooling air blown into a vehicle cabin; ) Driven by the evaporator (9)
A compressor (1) that compresses and discharges the refrigerant that has passed through the evaporator (9);
2) the temperature of the evaporator (9) is controlled by controlling the operation of the compressor (1) based on the detection signal of the temperature detecting means (32). The stop of the engine (4) is continued until the temperature of (9) becomes higher than that during the running of the vehicle. Further, when the state immediately before the stop is determined during the running of the vehicle,
An air conditioner for a vehicle, wherein the temperature of the evaporator (9) is reduced to a predetermined temperature or lower. 2. A target evaporator temperature on a low temperature side for preventing frost formation of the evaporator (9) during running of a vehicle, and a target evaporator temperature on a high temperature side for power saving of the engine (4). The vehicle according to claim 1, wherein the temperature of the evaporator (9) is controlled based on the target temperature, and the predetermined temperature is lower than a target evaporator temperature on the high temperature side. Air conditioner. 3. A first determining means (S2) for determining a first target evaporator temperature required for controlling the temperature of air blown into the vehicle interior.
20), a second determining means (S230) for determining a second target evaporator temperature required to maintain the humidity in the passenger compartment in a comfortable range, and a third target evaporation required to prevent fogging of the window glass. Third determining means (S240) for determining the temperature of the evaporator; fourth determining means (S250) for finally determining the lowest temperature among the first to third target evaporator temperatures as the target evaporator temperature during traveling. Further, when the traveling target evaporator temperature is higher than the predetermined temperature during traveling of the vehicle, when determining the state immediately before stopping,
The vehicle air conditioner according to claim 1, wherein the temperature of the evaporator (9) is reduced to the predetermined temperature or lower. 4. The air conditioner for a vehicle according to claim 1, wherein the state immediately before the stop is determined based on a vehicle driving signal including at least a vehicle speed signal. 5. The method according to claim 1, wherein when the acceleration state of the vehicle is judged after judging the state immediately before the stop, the reduction of the temperature of the evaporator to a predetermined temperature or less is canceled. 5. The vehicle air conditioner according to any one of 4. 6. A signal gradual change means for gradually changing a signal indicating an actual acceleration state of a vehicle with time and outputting the signal, and determining the acceleration state based on an output signal of the signal gradual change means. The vehicle air conditioner according to claim 5, wherein: