JP2003285618A - Air conditioner for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the shortage of room cooling immediately after vehicle running is resumed after engine stop in a vehicle that automatically stops the vehicle engine when the vehicle is stopped. <P>SOLUTION: In an air conditioner for vehicle including a variable displacement compressor of refrigeration cycle driven by a vehicle engine and mounted on a vehicle that automatically stops the vehicle engine when the vehicle is stopped, and also including an air-conditioning evaporator for cooling in-cabin blown air by a refrigerant that is circulated by operation of the compressor, acceleration-cut control for compulsively reducing the discharge capacity of the variable displacement compressor is started when it is judged that a predetermined acceleration condition of the vehicle engine occurs. Also, in a step S20 and step S30 of the above air conditioner for vehicle, when it is judged that the predetermined acceleration condition occurs for the first time immediately after the vehicle restarts to run since the vehicle engine is automatically stopped when the vehicle is stopped, a step S40 is followed and the acceleration cut- control is inhibited. <P>COPYRIGHT: (C)2004,JPO

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 that automatically stops a vehicle engine when the vehicle is stopped and driving a compressor of a refrigeration cycle by the vehicle engine.

[0002]

2. Description of the Related Art In recent years, vehicles (eco-run vehicles such as hybrid vehicles) that automatically stop the vehicle engine when the vehicle is stopped such as waiting for a signal have been put into practical use for the purpose of protecting the global environment and improving the fuel efficiency of the vehicle engine. Therefore, the number of vehicles that automatically stop the vehicle engine when the vehicle is stopped tends to increase in the future.

In a vehicle air conditioner, a compressor of a refrigeration cycle is usually driven by a vehicle engine. Therefore, in the above eco-run vehicle, the vehicle is stopped by waiting for a signal or the like, and every time the vehicle engine is stopped. The compressor also stops and the temperature of the cooling evaporator rises. As a result, the temperature of the air blown into the passenger compartment rises, which causes a problem that the cooling feeling of the occupant is impaired. However, if the cooling evaporator is sufficiently cooled while the vehicle is traveling, the air blown into the vehicle compartment can be cooled by the heat capacity of the cooling evaporator for several tens of seconds.

On the other hand, when the vehicle starts from a stopped state, a large output is required for the vehicle engine. Therefore, the driving load of the compressor on the vehicle engine is reduced to ensure the accelerating property of the vehicle engine. "Cut control" has been conventionally adopted. This acceleration cut control is, specifically, when the acceleration state of the vehicle engine is determined by the depression amount of the accelerator pedal or the like, in the case of a fixed displacement compressor, the electromagnetic clutch is disengaged to stop the compressor. In the case of a variable capacity compressor, the discharge capacity of the compressor is reduced to a small capacity.

[0005]

However, in the eco-run vehicle, when the effect of the acceleration cut control on the vehicle interior cooling state is actually evaluated, the compressor stops while the vehicle is stopped and the cooling evaporator is cooled. Since the vehicle restarts from the state where the temperature rises, if the compressor is stopped or the discharge capacity of the compressor is reduced by the acceleration cut control immediately after the restart of the vehicle, the cooling evaporator immediately after the restart of the vehicle is restarted. It was found that the temperature of the air blown out of the vehicle increased further than when it was stopped, and the lack of cooling in the vehicle compartment became more pronounced.

In view of the above points, an object of the present invention is to eliminate a shortage of cooling in a vehicle in which the vehicle engine is automatically stopped when the vehicle is stopped, immediately after the vehicle resumes running after the vehicle is stopped.

[0007]

In order to achieve the above object, according to the invention as set forth in claim 1, the invention is mounted on a vehicle that automatically stops the vehicle engine (4) when the vehicle is stopped, and is driven by the vehicle engine (4). Refrigeration cycle compressor (1)
And a cooling evaporator (9) that circulates a refrigerant by the operation of the compressor (1) to cool the air blown into the vehicle compartment, and determines the acceleration state of the vehicle engine (4) to determine the compressor (1 ) In a vehicle air conditioner that performs acceleration cut control for forcibly reducing the capability of (4), when a predetermined condition that represents a state immediately after the vehicle restarts after the vehicle engine (4) automatically stops when the vehicle is stopped is determined. Is characterized by prohibiting the acceleration cut control.

As a result, immediately after the vehicle resumes running after the vehicle is stopped, the capacity reduction of the compressor (1) due to the acceleration cut control is prohibited, and the capacity of the cooling evaporator (9) is fully exerted. , The lack of cooling can be solved.

According to a second aspect of the present invention, a compressor (1) for a refrigeration cycle, which is mounted on a vehicle that automatically stops the vehicle engine (4) when the vehicle is stopped, and is driven by the vehicle engine (4), and a compressor. A cooling evaporator (9) that circulates a refrigerant by operating the machine (1) to cool the air blown into the vehicle compartment, and determines the acceleration state of the vehicle engine (4) to determine the capacity of the compressor (1). In the vehicular air-conditioning system for performing the acceleration cut control for forcibly lowering the predetermined value, when the predetermined condition representing the state immediately after the vehicle restarts after the vehicle engine (4) automatically stops when the vehicle is stopped, It is characterized in that the threshold value for determining the acceleration state is changed by a predetermined amount so that it is difficult to determine the acceleration state as compared with the case where the condition is not determined.

Thus, the threshold value for determining the acceleration state can be changed immediately after the vehicle resumes running after the vehicle is stopped so that the acceleration state is not substantially determined. As a result, similarly to the first aspect, it is possible to prevent the capacity shortage of the compressor (1) due to the acceleration cut control immediately after the restart of the traveling, thereby solving the insufficient cooling.

The compressor (1) according to claims 1 and 2
Of the capacity of the compressor means that the discharge capacity of the compressor (1) is reduced.
It also includes all of the operation stoppage of the compressor (1).

According to the invention described in claim 3, claim 1
Alternatively, in 2 above, the predetermined condition specifically means that the vehicle speed is less than the predetermined vehicle speed.

According to the invention described in claim 4, claim 1
Alternatively, in 2 above, the predetermined condition may be, specifically, that the elapsed time after the traveling of the vehicle is restarted is less than the predetermined time.

According to the invention of claim 5, claim 1
Alternatively, in 2, the predetermined condition may be, specifically, a period until the information related to the actual temperature of the cooling evaporator (9) reaches a value corresponding to the predetermined temperature or less.

According to the invention of claim 6, claim 1
In 2 or 2, the predetermined condition is, specifically, until the difference between the information related to the actual temperature of the cooling evaporator (9) and the target value of the information decreases to a predetermined value or less. May be

[0016] As in the invention of claim 7, in claim 1, the predetermined condition is, specifically, even when the acceleration state is judged for the first time after the restart of the vehicle. Good.

According to the invention described in claim 8, claim 1
In the above, the predetermined condition may be that the number of times of determination of the acceleration state is within a predetermined number after the traveling of the vehicle is restarted.

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

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is an overall configuration diagram of the first embodiment, and a refrigeration cycle R of a vehicle air conditioner is provided with a compressor 1 that sucks, compresses, and discharges a refrigerant. ing. The compressor 1 is a variable capacity compressor configured so that the discharge capacity can be changed. The variable displacement compressor 1 is provided with a pulley 2, the power of the vehicle engine 4 is transmitted to the compressor 1 via a belt 3, and the compressor 1 is rotationally driven.

The variable displacement compressor 1 is also provided with an electromagnetic displacement control mechanism 1a for variably controlling the discharge displacement. The variable displacement compressor 1 can be specifically configured by a well-known swash plate compressor, and specifically, the pressure (control pressure) in the swash plate chamber in which the swash plate is arranged is controlled by an electromagnetic capacity control mechanism. 1a, thereby changing the inclination angle of the swash plate to change the working stroke of the piston, and the discharge capacity of the compressor 1 is changed to a minimum capacity and a maximum capacity (10%) near 0%.
0% capacity) can be continuously changed.

On the other hand, the electromagnetic capacity control mechanism 1a changes the control pressure by utilizing the discharge pressure and the suction pressure of the compressor 1, and the electromagnetic mechanism 1b whose electromagnetic force is adjusted by the control current In, and It has a control valve body 1c which is displaced by the balance between the electromagnetic force of the electromagnetic mechanism 1b and the suction pressure, and the control valve body 1c adjusts the pressure loss of the passage for guiding the discharge pressure of the compressor 1 into the swash plate chamber. It is designed to change the control pressure.

According to this, the target current of the suction pressure is set by the control current In of the electromagnetic capacity control mechanism 1a, and the discharge capacity of the compressor 1 is controlled so that the actual suction pressure becomes the target pressure. Since the suction pressure is almost the same as the refrigerant evaporation pressure of the evaporator 9, the temperature of the evaporator 9 (refrigerant evaporation temperature) can be controlled by controlling the suction pressure.

The control current In of the electromagnetic capacity control mechanism 1a is variably controlled by the output of the air conditioning electronic control unit 5 described later. Further, since the variable displacement compressor 1 of this example can reduce its discharge capacity to the minimum capacity around 0%, it does not have an electromagnetic clutch for power interruption. However, the operation of the compressor 1 may be completely stopped by adding an electromagnetic clutch for power interruption.

The high-temperature, high-pressure superheated gas refrigerant discharged from the compressor 1 flows into the condenser 6 and exchanges heat with the outside air blown from a cooling fan (not shown) to be cooled and condensed. The refrigerant condensed in the condenser 6 next flows into the liquid receiver 7, the gas-liquid of the refrigerant is separated inside the liquid receiver 7, and the surplus refrigerant (liquid refrigerant) in the refrigeration cycle R is received by the liquid receiver 7. It is stored inside.

The liquid refrigerant from the liquid receiver 7 is decompressed to a low pressure by the expansion valve 8 which constitutes a decompression means, and becomes a low pressure gas-liquid two-phase state. The expansion valve 8 is a thermal expansion valve having a temperature sensing portion 8a that senses the temperature of the outlet refrigerant of the evaporator 9. The low pressure refrigerant from the expansion valve 8 flows into the evaporator 9. This evaporator 9
Is a cooling heat exchanger installed in the air conditioning case 10 of the 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. Evaporator 9
Is connected to the suction side of the compressor 1 and forms a closed circuit by the cycle components described above.

In the air conditioning case 10, a blower 11 is arranged 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. The inside / outside air switching box 14 is disposed on the suction side of the blower fan 12, and the inside / outside air switching door 14a in the inside / outside air switching box 14 opens and closes the outside air introducing port 14b and the inside air introducing port 14c.
As a result, the outside air (air outside the passenger compartment) enters the inside / outside air switching box 14.
Alternatively, the inside air (air inside the vehicle) is switched and introduced. The inside / outside air switching door 14a is an electric drive device 14 including a servomotor.
driven by e. .

Inside the air conditioning case 10, an air mix door 19 is arranged downstream of the evaporator 9. On the downstream side of the air mix door 19, a hot water heater core 20 is installed as a heating heat exchanger that heats the air using the hot water (cooling water) of the vehicle engine 4 as a heat source.

A bypass passage 21 that bypasses the hot water heater core 20 and allows air (cool air) to flow is formed on the side (upper portion) of the hot water heater core 20. The air mix door 19 is a rotatable plate-shaped door, and is driven by an electric drive device 22 including a servomotor.

The air mix door 19 adjusts the air volume ratio between the warm air passing through the hot water heater core 20 and the cold air passing through the bypass passage 21. Adjust the blown air temperature of. Therefore, in this example, the air mix door 19 constitutes a temperature adjusting means for the air blown into the vehicle interior.

A warm air passage 23 extending from the lower side to the upper side is formed on the downstream side of the hot water heater core 20, and warm air from the warm air passage 23 and cold air from the bypass passage 21 are mixed in the air mixing section 24. Air at a desired temperature can be created.

Further, in the air conditioning case 10, a blowout mode switching section is formed on the downstream side of the air mixing section 24. That is, the air-conditioning case 10 has a defroster opening 25 that blows air toward the inner surface of the vehicle windshield, a face opening 27 that blows air toward the upper half of the passenger in the passenger compartment, and a foot that blows air toward the feet of the passenger in the passenger compartment. The opening 29 is formed. Then, the defroster opening 25, the face opening 27, and the foot opening 29.
Is opened and closed by a defroster door 26, a face door 28, and a foot door 30, each of which is composed of a rotatable plate-shaped door.

Blowout mode doors 26, 28, 30 described above
Are connected to a common link mechanism (not shown), and an electric drive device 31 composed of a servomotor is connected via this link mechanism.
Driven by.

The temperature sensor 32 of the evaporator 9 is the air conditioning case 1
It is arranged at a position immediately after the air is blown out of the evaporator 9 within 0, and detects the evaporator blowing temperature Te. Here, the detection signal of the temperature sensor 32 of the evaporator 9 is used to variably control the discharge capacity of the compressor 1 and maintain the evaporator outlet temperature Te at the target evaporator temperature TEO, as in a normal air conditioner. To be done.

In addition to the temperature sensor 32, the electronic control unit 5 for air conditioning has an inside air temperature Tr, an outside air temperature Tam, an amount of solar radiation Ts, a hot water temperature Tw, and a high pressure side pressure Ph of the refrigeration cycle R for controlling the air conditioning. A detection signal is input from a well-known sensor group 35 that detects the like. Further, the air conditioning control panel 36 installed near the instrument panel in the passenger compartment is provided with an operation switch group 37 that is manually operated by an occupant.
The operation signal 7 is also input to the air conditioning electronic control unit 5.

The operation switch group 37 includes a temperature setting switch 37a for generating a temperature setting signal Tset, an air volume switch 37b for generating an air volume switching signal, an air blowing mode switch 37c for generating an air blowing mode signal, and an inside / outside air switching signal. There are provided an inside / outside air switching switch 37d, an air conditioner switch 37e for generating an ON / OFF signal of the compressor 1, and the like.

Here, when an off signal is output from the air conditioner switch 37e, the compressor 1 is forcibly set to the minimum capacity state by the control device 5. Also, the air conditioner switch 37e
When the ON signal is output from the compressor 1, the compressor 1 is operated with the discharge capacity controlled by the controller 5.

Further, the air-conditioning electronic control unit 5 is connected to the engine electronic control unit 38. From the engine electronic control unit 38 to the air-conditioning electronic control unit 5, the rotation speed signal, the vehicle speed signal of the vehicle engine 4, An accelerator pedal depression amount signal or the like is input.

As is well known, the engine electronic control unit 38 comprehensively determines the fuel injection amount, ignition timing, etc. to the vehicle engine 4 based on a signal from a sensor group (not shown) for detecting the operating condition of the vehicle engine 4. That is controlled in a controlled manner. Furthermore, in the eco-run vehicle that is the target of this embodiment,
When the stop state is determined based on the rotation speed signal, the vehicle speed signal, the brake signal, etc. of the vehicle engine 4, the engine electronic control unit 38 automatically shuts down the vehicle engine 4 by shutting off the power of the ignition device, stopping the fuel injection, or the like. Stop.

When the driver releases the brake pedal and depresses the accelerator pedal to start the engine after the engine is stopped, the electronic control unit 38 for the engine determines the starting operation of the vehicle based on the accelerator signal or the like. , The vehicle engine 4 is automatically started.

The air-conditioning electronic control unit 5 and the engine electronic control unit 38 are composed of a well-known microcomputer including a CPU, a ROM, a RAM and the like and its peripheral circuits.

Next, the operation of the first embodiment having the above structure will be described. First, the overall operation of the vehicle air conditioner shown in FIG. 1 will be described. When the vehicle is traveling, the vehicle engine 4 drives the compressor 1 and the refrigerant discharged from the compressor 1 circulates in the refrigeration cycle R. Then, the low-temperature low-pressure gas-liquid two-phase refrigerant whose pressure has been reduced by the expansion valve 8 flows into the evaporator 9, and this low-pressure refrigerant absorbs heat from the air blown by the blower 11 and evaporates to blow air. Is cooled and dehumidified,
It becomes cold wind.

The outlet temperature Te of the evaporator 9 is controlled so as to reach the target evaporator temperature TEO by variably controlling the discharge capacity of the compressor 1 as described later. Then, the cold air after passing through the evaporator 9 is distributed to the ventilation passage of the heater core 20 and the bypass passage 21 according to the opening degree of the air mix door 19, and the temperature is adjusted. The conditioned air after the temperature adjustment blows out from the defroster opening 25, the face opening 27, or the foot opening 29 into the vehicle interior to air-condition the vehicle interior.

On the other hand, when the vehicle is stopped from the running state, the engine electronic control unit 38 determines the stopped state and automatically stops the vehicle engine 4. As a result, the compressor 1
Is also stopped, and the evaporative cooling action of the refrigerant in the evaporator 9 is stopped. However, for a while, the cooling of the blown air can be continued due to the heat capacity of the evaporator 9 and the evaporation of condensed water of the evaporator.

When the driver performs a starting operation after the vehicle has stopped, the engine electronic control unit 38 determines the starting state of the vehicle based on the accelerator signal or the like, and automatically starts the vehicle engine 4. It is started and the vehicle shifts to a running state. As a result, the compressor 1 is restarted and the cooling action of the evaporator 9 is restarted.

Next, the discharge capacity control and the acceleration cut control of the variable capacity compressor 1 according to the first embodiment will be specifically described with reference to FIG. FIG. 2 is a flowchart of the discharge capacity control and the acceleration cut control of the variable displacement compressor 1 in the air conditioning overall control executed by the microcomputer of the air conditioning electronic control unit 5.

First, in step S10, the vehicle engine 4
Accelerator pedal depression amount ACC (%) and vehicle speed S
Read PD (km / h). Next, in step S20, it is determined whether or not the vehicle engine 4 is in a predetermined acceleration state based on the accelerator pedal depression amount and the vehicle speed.

The determination in step S20 is specifically made as shown in FIGS. That is, FIG. 3 is a control map stored and held in the ROM of the control device 5, which distinguishes the acceleration state and the normal operation state of the vehicle engine 4.
Threshold values ACH, A of accelerator pedal depression amount ACC
CL is determined according to the vehicle speed SPD. In particular,
Threshold values ACH, ACL as vehicle speed SPD increases
Is rising. The difference between the upper threshold value ACH and the lower threshold value ACL is a hysteresis width for preventing hunting in acceleration cut control.

Then, as shown in FIG. 4, when the accelerator pedal depression amount ACC is in a region larger than the upper threshold value ACH, it is determined that the vehicle engine 4 is in an accelerating state. That is, it is determined whether the acceleration cut condition is satisfied. On the other hand, when the accelerator pedal depression amount ACC is in a region smaller than the lower threshold ACL, it is determined that the vehicle engine 4 is in the normal operation state.

To give a concrete example, for example, the vehicle speed SPD =
When the accelerator pedal depression amount ACC becomes 20% from 0 km / h (stopped state), the acceleration state of the vehicle engine 4 is determined, and the vehicle speed SPD is determined by continuing this acceleration state.
Becomes 30 km / h, the accelerator pedal depression amount A
Even if CC is reduced to 13%, it is still within the acceleration judgment range. Furthermore, the vehicle speed SPD rises to 50 km / h
Then, when the accelerator pedal depression amount ACC decreases to 8%, it is determined that the vehicle engine 4 has transitioned to the normal operating state.

When the acceleration state is determined by the above determination method in step S20, it is determined in the next step S30 whether or not this acceleration state is the first determination after the traveling is restarted. Then, when the vehicle is in the first acceleration state after the traveling is restarted, the process proceeds to step S40, the acceleration cut control is prohibited, and the control current In is calculated.

That is, in step S40, when calculating the control current In for the discharge capacity control of the variable displacement compressor 1, the control current I is calculated by the original calculation method according to the cooling heat load.
Calculate n. Specifically, the control current In is calculated by a control formula such as proportional-plus-integral (PI) control according to the deviation between the actual blowout temperature Te of the evaporator 9 and the target evaporator temperature TEO.

In this example, when the control current In becomes small, the compressor discharge capacity changes to the small capacity side, and when the control current In becomes large, the compressor discharge capacity changes to the large capacity side. Is configured. Therefore, when the cooling heat load is high, that is, the larger the deviation of (Te-TEO) is, the calculated value of In is increased and the discharge capacity of the variable capacity compressor 1 is increased.

As is well known, the target evaporator temperature TEO is usually set to a temperature slightly higher than 0 ° C. in order to prevent the frost of the evaporator 9, and the air-conditioning environmental condition, specifically, For example, it is a value that varies according to changes in the target outlet temperature TAO of the conditioned air blown into the passenger compartment and the outside air temperature Tam.

In the next step S50, the above step S
The control current In calculated in 40 is used as the electromagnetic capacity control mechanism 1
Then, the discharge capacity of the compressor 1 is set to a capacity corresponding to In.

While the first acceleration state after the restart of the vehicle is continued, the determination result of YES in step S30 is continued, and the control state of the discharge capacity according to the cooling heat load in step S40 is continued. It

When the vehicle speed SPD rises or the accelerator pedal depression amount ACC decreases with the passage of time after the vehicle restarts, the accelerator pedal depression amount ACC becomes lower than the lower threshold ACL. When entering a small area, it is determined in step S20 that the vehicle engine 4 is in a normal operation state. As a result, the process directly proceeds from step S20 to step S40, and the prohibition state of the acceleration cut control is continued. That is, the original calculation method of the control current In according to the cooling heat load is continued.

After that, the accelerator pedal depression amount ACC
When, for example, the vehicle engine 4 shifts to the acceleration state again due to the increase of, the determination in step S20 becomes YES, and the process proceeds to step S30. In this case, since the vehicle is in the second acceleration state after the traveling is restarted, the determination in step S30 is NO.
Then, the process proceeds to step S60, and the control current In for which the acceleration cut control is executed is calculated.

Specific examples of this acceleration cut control are shown in FIGS.
5, the control current I in the case where the vehicle engine 4 shifts to the acceleration state between the times t0 and t1 is described.
This is a specific example of calculation of n, and the control current In at time t0 immediately after shifting to the acceleration state is
The current value F5 (Ph) determined by the refrigeration cycle high pressure side pressure Ph at 0 is reduced.

This current value F5 (Ph) is determined so as to increase in proportion to the increase in the refrigeration cycle high pressure side pressure Ph, as shown in FIG. Here, since the refrigeration cycle high-pressure side pressure Ph has a relationship of increasing as the cooling heat load of the evaporator 9 increases, when the cooling heat load is low, the current value F5 (P
When h) becomes small and the cooling heat load is high, the current value F5
(Ph) becomes large.

In this example, since the maximum value of the control current In is 0.75 A, the current value F5 (Ph) immediately after shifting to the acceleration state changes according to the characteristic shown in FIG. Accordingly, the value is determined to be sufficiently smaller than the maximum value.

Then, FIG. 7 shows a current value F which increases according to the elapsed time from time t0 immediately after the acceleration state is shifted.
6 (t).

As shown in FIG. 5, when the time elapses from the time t0, the control current In becomes In = F5 (Ph) + F6.
It is calculated as (t), increases with the lapse of time, and returns to the current value before the shift to the acceleration state.

The control current In for which the acceleration cut control is executed is calculated as described above, and the calculated value of the control current In is output to the electromagnetic capacity control mechanism 1a in step S50 to discharge the compressor 1. The capacity is reduced to a capacity corresponding to In, the compressor drive load of the vehicle engine 4 is reduced, and the acceleration of the vehicle engine 4 is secured.

Next, the function and effect of the first embodiment will be described with reference to FIG. FIG. 8 shows changes in the evaporator outlet temperature Te and the control current In with respect to changes in the vehicle speed SPD and the accelerator pedal depression amount ACC, in comparison between the conventional technique (broken line) and the first embodiment (solid line). The term “eco-run stop” in FIG. 8 refers to a state in which the vehicle engine 4 is automatically stopped by the automatic control of the control device 38 when the vehicle is stopped.

In FIG. 8, in a state before the stop of the eco-run, for example, the vehicle is traveling at a constant speed SPD = 50 km / h, and the accelerator pedal depression amount ACC at that time is running.
Is 8%. During this constant speed traveling, the variable displacement compressor 1
The control current I is stable at about 0.5 A, and the evaporator outlet temperature Te is stable at about 6 ° C.

When the accelerator pedal depression amount ACC is set to 0 to decelerate from the above-described constant speed running and the vehicle stops, the vehicle engine 4 is automatically stopped and the eco-run stop state is set. In this eco-run stopped state, the compressor 1 also stops with the stop of the vehicle engine 4, so the evaporator outlet temperature Te gradually rises. In FIG. 8, it is assumed that the evaporator outlet temperature Te has risen to 15 ° C.

Next, when the vehicle is restarted from the state where the eco-run is stopped, when the operator releases the brake pedal and depresses the accelerator pedal, the control device 38 determines this starting operation and the vehicle engine 4 automatically operates. Will be restarted. At this time, when the driver depresses the accelerator pedal by, for example, 20% to accelerate the vehicle, in the conventional technique, it is determined that the vehicle engine 4 is in the accelerating state based on the determination criteria of FIGS. 3 and 4, and the control current In is indicated by a broken line. As shown, the discharge capacity of the compressor 1 is forcibly reduced to a small value (for example, 0.3 A) regardless of the cooling heat load. That is, in the prior art, the evaporator cut-off temperature Te rises as shown by the broken line by performing the acceleration cut control immediately after the restart of the vehicle after the eco-run is stopped, which causes insufficient cooling and gives an occupant a discomfort. .

On the other hand, in the first embodiment,
In step S30 of FIG. 2, it is determined whether the acceleration state of the vehicle engine 4 is the first acceleration state after the vehicle running is restarted after the eco-run is stopped. If the acceleration state is the first acceleration state, the process proceeds to step S40 to accelerate the vehicle. Since the cut control is prohibited and the original control current In corresponding to the cooling heat load of the evaporator 9 is calculated, the control current In is calculated as the maximum value of 075A immediately after the restart of the vehicle after the eco-run stop. .

As a result, the discharge capacity of the compressor 1 becomes the maximum capacity and the compressor 1 exhibits the maximum capacity, so that the circulating refrigerant flow rate in the cycle becomes the maximum. Therefore, the evaporator 9
The cooling capacity is maximized, and the evaporator outlet temperature Te can be rapidly lowered toward the target evaporator temperature TEO. As a result, the shortage of cooling immediately after the restart of the vehicle after the eco-run is stopped can be resolved.

In the first embodiment, as described above,
In step S30 of FIG. 2, it is determined whether the acceleration state of the vehicle engine 4 is the first acceleration state after the restart of the vehicle running after the eco-run is stopped. It is determined whether it is within a predetermined number of times (for example, the second time or the third time) after restarting the vehicle, and if the acceleration state after restarting the vehicle after stopping the eco-run is within the predetermined number of times, the acceleration cut control is prohibited. You may do it.

According to this, although the period in which the acceleration of the vehicle engine 4 is sacrificed becomes long, the effect of ensuring the cooling performance immediately after the restart of the vehicle after the stop of the eco-run can be improved.

(Second Embodiment) In the first embodiment, it is judged whether or not the acceleration state of the vehicle engine 4 is the first acceleration state after restarting the vehicle after the eco-run stop or within a predetermined number of times. However, in the second embodiment, the threshold value for determining the acceleration state after the restart of the vehicle after the eco-run stop makes it difficult to determine the acceleration state. Change to.

FIG. 9 shows the control of the second embodiment, and steps with the same reference numerals as in FIG. 2 are the same processing. In the second embodiment, the vehicle speed SPD and the accelerator pedal depression amount ACC are read in step S10, and it is determined in step S70 whether or not the vehicle has just restarted after the eco-run stop. That is, it is determined whether or not the predetermined condition indicating immediately after the restart of the vehicle is satisfied. Specifically, it is determined whether or not the vehicle speed SPD has risen above a predetermined vehicle speed after the vehicle travel is resumed.

When the vehicle speed SPD is lower than the predetermined vehicle speed after the vehicle is restarted, the determination in step S70 becomes YES, the process proceeds to step S80, and the threshold value for accelerating state determination described in FIG. Threshold value ACH, AC
“Threshold values ACH ′, ACL ′” higher than “L” are set. This higher "threshold ACH ', ACL'"
As shown in FIG. 10, the threshold value of the accelerator pedal depression amount ACC for determining whether or not the vehicle is in the acceleration state is set sufficiently higher than the normal “threshold value ACH, ACL”.
Setting this "threshold value ACH ', ACL'" makes it difficult to determine the acceleration state.

When the vehicle speed SPD rises above the predetermined vehicle speed after the vehicle is restarted, the routine proceeds to step S90, where the normal "threshold AC
H, ACL ”is set.

Then, in the next step S20, it is determined whether or not the vehicle engine 4 is in the accelerating state based on the above-mentioned normal "threshold ACH, ACL" or higher "threshold ACH ', ACL'". To do.

Here, immediately after the vehicle restarts after the eco-run is stopped, by using a higher "threshold value ACH ', ACL'", the accelerator pedal depression amount ACC based on the normal start operation is all lowered. Side threshold ACL '
Results below. Therefore, since the acceleration state immediately after the vehicle travel is restarted is determined as a normal driving state, the process proceeds from step S20 to step S40, the acceleration cut control is prohibited, and the control current In is calculated.

As a result, similarly to the first embodiment, the discharge capacity of the compressor 1 is set to the maximum capacity immediately after the traveling of the vehicle is restarted,
When the cooling capacity of the evaporator 9 is maximized, the evaporator outlet temperature Te
Can be rapidly reduced toward the target evaporator temperature TEO.

On the other hand, when the vehicle speed SPD increases above the predetermined vehicle speed after the vehicle restarts, the normal "threshold values ACH, ACL" set in step S90 are compared with the accelerator pedal depression amount ACC. Since it is determined whether the vehicle engine 4 is in the accelerating state, thereafter, the accelerating state is determined normally, and if the accelerating state is determined, the acceleration cut control is executed in step S60 to execute the vehicle engine 4 Secure the acceleration of.

(Other Embodiments) In the first embodiment, the acceleration state of the vehicle engine 4 is determined by determining whether the acceleration state is the first acceleration state after restarting the vehicle after the eco-run stop or within a predetermined number of times. Although it has been decided to prohibit or execute the cut control, the determination of the number of acceleration states after the vehicle traveling is restarted is abolished in the first embodiment, and instead, immediately after the vehicle traveling is restarted as in the second embodiment. A predetermined condition (for example, vehicle speed SPD
Is less than a predetermined vehicle speed), acceleration cut control may be prohibited while this predetermined condition is satisfied, and acceleration cut control may be executed when this predetermined condition is not satisfied. .

In the first and second embodiments, as the predetermined condition indicating immediately after the restart of the vehicle traveling, instead of the vehicle speed SPD, it is determined whether or not the elapsed time after the restart of the vehicle is less than the predetermined time. Good.

In the first and second embodiments, it is determined whether or not the actual blown-air temperature Te of the evaporator 9 has dropped to a temperature equal to or lower than the predetermined temperature as the predetermined condition immediately after the vehicle restarts. Good.

In the first and second embodiments, whether or not the difference between the actual blown air temperature Te of the evaporator 9 and the target evaporator temperature TEO has decreased to a predetermined value or less is set as the predetermined condition immediately after the vehicle restarts. Alternatively, it may be determined.

In the above case, the fin surface temperature of the evaporator 9 and the refrigerant pipe surface temperature of the evaporator 9 may be detected instead of the blown air temperature Te of the evaporator 9. In short,
Any information that is substantially related to the temperature of the evaporator 9 can be used.

In the first and second embodiments, when the eco-run is stopped for a long time and the evaporator outlet temperature Te rises above a predetermined temperature, it is determined whether the evaporator outlet temperature Te rises. The signal for requesting the restart of the vehicle engine 4 may be output from the electronic control unit for air conditioning 5 to the electronic control unit for engine 38. As a result, the engine electronic control unit 38 starts the vehicle engine 4, restarts the compressor 1, and restarts the cooling operation of the evaporator 9.

In the first and second embodiments, a variable displacement compressor is used as the compressor 1 and the discharge capacity of the variable displacement compressor 1 is forcibly reduced to reduce the compressor drive load. Although the acceleration cut control is executed, a fixed displacement type compressor in which transmission of engine power is intermittently performed by an electromagnetic clutch is used as the compressor 1, and when the acceleration state is determined, the electromagnetic clutch is cut off to fix the fixed displacement type compressor. It is well known in the related art to execute the acceleration cut control by stopping the operation of No. 1, and the present invention may be applied to this well known control system.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing discharge capacity control of the compressor according to the first embodiment.

FIG. 3 is a characteristic diagram of a threshold value for determining an acceleration state in the first embodiment.

FIG. 4 is an explanatory diagram of a specific determination method based on the threshold value of FIG.

FIG. 5 is a characteristic diagram for determining a discharge current control current in the first embodiment.

FIG. 6 is a characteristic diagram showing the relationship between the discharge current control current and the refrigeration cycle high pressure side in the first embodiment.

FIG. 7 is a characteristic diagram showing the relationship between the elapsed time after the start of the acceleration cut control and the control current of the discharge capacity in the first embodiment.

FIG. 8 is an operation explanatory diagram showing a comparison between the first embodiment and changes in the control current for the evaporator outlet air temperature and the discharge capacity of the prior art.

FIG. 9 is a flowchart showing discharge capacity control of the compressor according to the second embodiment.

FIG. 10 is a characteristic diagram of threshold values for determining an acceleration state in the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Variable capacity compressor, 1a ... Capacity control mechanism, 4 ... Vehicle engine, 5 ... Air-conditioning electronic control device (control means), 9 ...
Evaporator.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B60H 1/32 B60H 1/32 623N (72) Inventor Takahashi Tsunehiro 1-chome, Showa-cho, Kariya city, Aichi prefecture In stock company DENSO (72) Inventor Yukishi Kato 1 Toyota-cho, Toyota-shi, Aichi F-term in Toyota Motor Corporation (reference) 3L011 AC02

Claims (8)

[Claims] 1. A compressor (1) for a refrigeration cycle, which is mounted on a vehicle that automatically stops a vehicle engine (4) when the vehicle is stopped, and which is driven by the vehicle engine (4); And an evaporator (9) for cooling that cools the air blown into the vehicle compartment by circulating the refrigerant by operation, and determines the acceleration state of the vehicle engine (4) to force the capacity of the compressor (1). In a vehicular air-conditioning system for performing an acceleration cut control to reduce the acceleration cut, when a predetermined condition representing a state immediately after the vehicle engine (4) is automatically stopped when the vehicle is stopped and the vehicle is restarted is determined, the acceleration cut is performed. A vehicle air conditioner characterized by prohibiting control. 2. A refrigeration cycle compressor (1) mounted on a vehicle that automatically stops a vehicle engine (4) when the vehicle is stopped, and driven by the vehicle engine (4); And an evaporator (9) for cooling that cools the air blown into the vehicle compartment by circulating the refrigerant by operation, and determines the acceleration state of the vehicle engine (4) to force the capacity of the compressor (1). In a vehicular air-conditioning system that performs acceleration cut control to reduce to a predetermined value, when the predetermined condition that represents a state immediately after restart of traveling of the vehicle is determined after the vehicle engine (4) automatically stops when the vehicle is stopped, the predetermined condition is determined. The vehicle air conditioner is characterized in that the threshold value for determining the acceleration state is changed by a predetermined amount to a side that makes it difficult to determine the acceleration state, as compared to when not determining. 3. The vehicle air conditioner according to claim 1, wherein the predetermined condition is that the vehicle speed is less than the predetermined vehicle speed. 4. The vehicle air conditioner according to claim 1, wherein the predetermined condition is that an elapsed time after the vehicle is restarted is less than a predetermined time. 5. The predetermined condition is a period until the information related to the actual temperature of the cooling evaporator (9) reaches a value corresponding to a predetermined temperature or less. Or the vehicle air conditioner described in 2. 6. The predetermined condition is until the difference between the information related to the actual temperature of the cooling evaporator (9) and the target value of the information is reduced to a predetermined value or less. The vehicle air conditioner according to claim 1 or 2. 7. The vehicle air conditioner according to claim 1, wherein the predetermined condition is a time when the acceleration state is determined for the first time after the traveling of the vehicle is resumed. 8. The air conditioner for a vehicle according to claim 1, wherein the predetermined condition is that the number of times the acceleration state is determined is within a predetermined number after the vehicle resumes traveling.