JPH05116529A - Method of controlling vehicle air compressor - Google Patents

Abstract

PURPOSE:To prevent an engine from overheating, by lowering the capacity of a variable volume type air compressor as the engine temperature increases during driving of the compressor. CONSTITUTION:A required capacity (CACDTY: duty ratio) for an air compressor 64 in accordance with a cooling water temperature Tw is stepwise determined. That is, the cooling water temperature Tw is compared with a low temperature set value ACDTw1, and if Tw>= ACDTw1, a set value TBCDY1 which is slightly smaller than a maximum value TBACDY is used. Then, Tw is compared with a middle set value ACDTw2, and if T'<w>>ACDT<w2>, a newest demand capacity CACDTYNEW is set is used a set value TBACDP<2> having a relatively small capacity. Next, T<w> is compared with a high temperature set value ACDT<w3>, and if T<w> >= ACDT<w3>, the newest required capacity CACDTYNEW is set to a minimum value TBACDY<3> so as to prevent an engine from overheating.

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 compressor control method capable of controlling the drive stop timing or the capacity of a variable capacity air conditioner compressor.

[0002]

2. Description of the Related Art Generally, in an air conditioner compressor mounted on a vehicle, a part of the output of the engine is used as a drive source, and the load applied to the engine varies greatly depending on whether the air conditioner compressor is driven or not driven.

For example, Japanese Patent Laid-Open No. 63-54558 uses a variable capacity air conditioner compressor to change the capacity according to the blowing temperature of the refrigerant gas to prevent the cooling capacity from becoming excessive or excessive. , A technique for relatively reducing the load on the engine is disclosed.

[0004]

However, if the air conditioner compressor is continuously driven as it is, for example, when the engine temperature is high, the engine temperature rises, resulting in overheating.

Further, when the air conditioner compressor is driven at the same time when the air conditioner switch is turned on, the engine load sharply increases, so that the engine speed drops (engine speed fluctuation). On the other hand, if you turn off the air conditioner switch and stop the drive of the air conditioner compressor at the same time,
Since the load is suddenly released, the engine speed rapidly rises (so-called upstroke), which deteriorates the driving feeling.

The present invention has been made in view of the above circumstances, and prevents the engine from overheating due to the driving of the air conditioner compressor, and prevents the driving feeling from deteriorating due to the load fluctuation immediately after the air conditioner compressor is driven or not driven. It is an object of the present invention to provide a vehicle air conditioner compressor control method that can be performed.

[0007]

1) In order to achieve the above object, a first vehicle air conditioner compressor control method according to the present invention comprises a procedure for detecting whether or not a variable capacity air conditioner compressor is in operation, and the capacity variable. And a procedure for detecting the engine temperature when the automatic air conditioner compressor is in operation and decreasing the capacity of the variable capacity air conditioner compressor as the engine temperature increases.

2) In order to achieve the above object, a second vehicle air conditioner compressor control method according to the present invention comprises a procedure for detecting whether or not an air conditioner switch is on, and a variable capacity air conditioner after a set time has elapsed after the air conditioner switch was turned on. It comprises a procedure for driving the compressor and a procedure for increasing the capacity of the air conditioner from a low capacity to a normal capacity after the capacity variable air conditioner compressor is driven.

3) In order to achieve the above object, a third vehicle air conditioner compressor control method according to the present invention comprises a procedure for detecting whether or not the air conditioner switch is on, and a variable capacity air conditioner after a set time has elapsed after the air conditioner switch was turned off. It is provided with a procedure of stopping the compressor and a procedure of reducing the capacity of the air conditioner to a low capacity side until the capacity variable air conditioner compressor is stopped after the air conditioner switch is turned off.

[0010]

1) In the first vehicle air conditioner compressor control method according to the present invention, it is first detected whether or not the variable capacity air conditioner compressor is in operation, and if the variable capacity air conditioner compressor is in operation, the engine temperature is detected. Is detected, and the capacity of the variable capacity air conditioner compressor is decreased as the engine temperature increases.

Since the capacity of the variable capacity air conditioner compressor is reduced in accordance with the increase in engine temperature, the load on the engine is reduced according to the temperature of the cooling water, and overheating can be avoided.

2) In the second vehicle air conditioner compressor control method according to the present invention, first, it is detected whether or not the air conditioner switch is turned on, and the variable capacity air conditioner compressor is driven after a set time has elapsed after the air conditioner switch was turned on.

The capacity of the air conditioner is increased from a low capacity to a normal capacity after the variable capacity air conditioner compressor is driven.

As a result, immediately after the air conditioner compressor is driven, a sudden load is not applied to the engine and it is possible to prevent the engine speed from dropping.

3) In the third vehicle air conditioner compressor control method according to the present invention, first, it is detected whether or not the air conditioner switch is turned on, and the variable capacity air conditioner compressor is stopped after the set time has elapsed after the air conditioner switch was turned off.

Further, the air conditioner capacity is reduced to the low capacity side until the variable capacity air conditioner compressor is stopped after the air conditioner switch is turned off.

As a result, it is possible to avoid a sudden decrease in the load on the engine when the air conditioner compressor is released, and to prevent the engine speed from rising.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a flow chart showing a capacity control procedure of a variable capacity air conditioner compressor, FIG. 2 is a flow chart showing a control signal output procedure to a capacity variable air conditioner compressor, and FIG.
5 is a flow chart showing the control procedure of the air conditioner clutch relay, FIG. 6 is a flow chart showing the timer setting procedure, FIG. 7 is a schematic view of the engine, FIG. 8 and FIG. 9 are configuration diagrams of the control device, and FIG. FIG. 11 is an explanatory view showing a judgment flag in a hysterisis state, FIG. 11 is an explanatory view showing a cooling water temperature judgment flag in a hysteresis state, and FIG. 12 is a time chart of an air conditioner clutch relay, an air conditioner compressor capacity, and an engine speed according to ON / OFF of an air conditioner switch. FIG. 13 is a schematic diagram of a variable capacity air conditioner compressor.

[Structure of engine control system] In FIG.
Reference numeral 1 in the drawing denotes an engine body, which shows a 6-cylinder horizontally opposed engine. In this engine body 1, a cylinder block 2 is divided into two banks (a left bank on the right side and a right bank on the left side) on both sides of a crankshaft 1a as a center. #
A cylinder group of 5 cylinders is arranged, # 2, # 4, # in the left bank
A cylinder group of 6 cylinders is arranged.

In each cylinder head 3 of each bank,
Each intake port 4 is formed, and an intake manifold 5 is connected to each intake port 4. Resonance tubes 6a and 6b are connected to the upstream side of the intake manifold 5 corresponding to the banks, and a variable intake valve 11c is provided in a passage 6c connecting the resonance tubes 6a and 6b. The resonance pipes 6a and 6b, the passage 6c, and the variable intake valve 11c constitute a variable resonance supercharging system.

Further, the upstream sides of the resonance tubes 6a and 6b are communicated with the surge tank 7 through the throttle chambers 11a and 11b.

An intake pipe 8 is provided upstream of the surge tank 7.
An air cleaner 9 is attached via the air cleaner 9, and an intake air amount sensor (a hot film type air flow meter in the figure) 10 is provided immediately downstream of the dust air cleaner 9.

Further, each of the throttle chambers 11a,
Throttle valves 11c and 11d (so-called twin throttle valves) are provided in 11b, and one throttle valve 11c is provided with a throttle opening sensor 12a and an idle switch 12b for detecting the throttle valve fully closed.
And are lined up.

Further, the throttle chamber 11a,
A downstream side of the throttle valves 11c and 11d of 11b is communicated with a passage 6d, and an idle speed control (ISC) valve 13 is provided in an air bypass passage 6e which communicates the passage 6d with the surge tank 7.

An injector 14 is disposed immediately upstream of each intake port 4 of each cylinder of the intake manifold 5, and the tip of each injector of each cylinder head 3 is exposed to the combustion chamber. A spark plug 15 is attached. The ignition coil 15 a is directly attached to the terminal portion of the ignition plug 15 and connected to the igniter 16.

The injector 14 includes a fuel tank 1
Fuel is pressure-fed from an in-tank type fuel pump 18 provided inside 7 through a fuel filter 19 and regulated by a pressure regulator 20.

Further, a cooling water temperature sensor 21 is exposed to a cooling water passage (not shown) formed in the cylinder block 2, and right bank knock sensors 22a, 22a, 22a, 22d are provided in the banks of the cylinder block 2, respectively. A left bank knock sensor 22b is attached, and the exhaust ports 23 of the cylinder heads 3 are connected to the exhaust pipes 24a and 24b provided for each bank.

The right bank O ₂ sensor 25a and the left bank O ₂ sensor 2 are connected to the exhaust pipes 24a and 24b, respectively.
5b, the catalytic converters 26a and 26b are respectively provided on the downstream sides of the O ₂ sensors 25a and 25b, and the catalytic converter 27 is further provided on the downstream merging portion of the catalytic converters 26a and 26b. Has been done.

On the other hand, a crank angle detecting crank rotor 29 and a group cylinder discriminating crank rotor 30 are mounted on the crank shaft 1a of the engine main body 1 with a predetermined gap therebetween. In addition, each crank rotor 29, 3
On the outer periphery of 0, a first crank angle sensor 31 and a second crank angle sensor 32, each of which is composed of an electromagnetic pickup or the like for detecting a protrusion as an object to be detected, are provided in pairs. Further, a cam angle sensor 34 is provided opposite to the outer periphery of the cam rotor 33a axially attached to the cam shaft 33. The cam angle sensor 34 determines the compression top dead center of a specific cylinder, and the individual cylinders are determined by the cam pulse from the cam angle sensor 34 and the group determination pulse from the second crank angle sensor 32.

The crank rotors 29, 30,
Slits may be provided on the outer periphery of the cam rotor 33a instead of the protrusions, and both crank angle sensors 31, 3 may be provided.
2. The cam angle sensor 34 is not limited to an electromagnetic sensor such as an electromagnetic pickup, but may be an optical sensor or the like.

[Circuit Configuration of Controller] Meanwhile, FIG. 8 and FIG.
In the figure, reference numeral 40 is an engine control unit (ECU) composed of a microcomputer, and the ECU 40 is a main computer 4 that performs ignition timing control, fuel injection control and the like.
1 and a dedicated sub computer 4 for performing knock detection processing
It is composed of two computers 2 and 2.

Further, the constant voltage circuit 4 is provided in the ECU 40.
3 is built in, and a stabilizing voltage is supplied from the constant voltage circuit 43 to each part. The constant voltage circuit 43 is connected to a battery 45 via a relay contact of an ECU relay 44, and the relay coil of the ECU relay 44 is a key switch 46.
It is connected to the battery 45 via. Further, the fuel pump 18 is connected to the battery 45 via a relay contact of a fuel pump relay 47.

The main computer 41 is a main C
PU48, ROM49, RAM50, backup RA
M50a, timer 51, serial interface (S
The CI) 52 and the I / O interface 53 are connected to each other via a bus line 54. A backup voltage is constantly applied to the backup RAM 50a via the constant voltage circuit 43.

The input port of the I / O interface 53 has an intake air amount sensor 10, a throttle opening sensor 12a, a cooling water temperature sensor 21, and a right bank O ₂ sensor 2.
5a, left bank O ₂ sensor 25b is A / D converter 57a
Connected through the idle switch 1
2b, the first and second crank angle sensors 31, 32, and the cam angle sensor 34 are connected, and the battery 45 is connected to monitor the battery voltage.

Further, the I / O interface 53 is provided.
A starter switch 61 for detecting a starting state is connected to the input port of the.

An igniter 16 is connected to the output port of the I / O interface 53, and further an I
The relay coil of the air conditioner clutch relay 65 that operates the connection / disconnection of the SC valve 13, the injector 14, and the magnet clutch 64a of the variable capacity compressor 64 is connected via the drive circuit 57b.

On the other hand, the sub-computer 42 is a sub-CP.
U66, ROM67, RAM68, timer 69, SCI
70 and an I / O interface 71 are connected to each other via a bus line 72.

At the input port of the I / O interface 71, the first and second crank angle sensors 31, 3 are provided.
2, the cam angle sensor 34 is connected, the right bank knock sensor 22a, the left bank knock sensor 22b
, Respectively, an amplifier 73, a frequency filter 74, and an A / D
It is connected via a converter 75.

Each of the knock sensors 22a and 22b includes, for example, a vibrator having substantially the same natural frequency as the knock vibration,
This resonance type knock sensor is composed of a piezoelectric element that detects the vibration acceleration of this vibrator and converts it into an electric signal.The vibration that is transmitted to the cylinder block by the combustion pressure wave during the engine's explosion stroke is detected. The waveform is output as a knock signal.

The knock signal is amplified to a predetermined level by the amplifier 73, a necessary frequency component is extracted by the frequency filter 74, and converted from analog data to digital data by the A / D converter 75.

The main computer 41 and the sub computer 42 are connected by a serial line via SCIs 52 and 70, and the output port of the I / O interface 71 of the sub computer 42 is connected to the main computer 41. It is connected to the input port of the I / O interface 53.

The main computer 41 calculates the ignition timing based on the crank pulse, and when the predetermined ignition timing is reached, outputs an ignition signal to the corresponding cylinder, while
The sub-computer 42 calculates the engine speed from the crank pulse input interval, and based on the engine speed and the engine load, each knock sensor 22a, 2
Whether a knock signal is generated or not is set by setting a sample section of the knock signal from 2b, and at the sample section, the knock signal from each of the knock sensors 22a and 22b is A / D-converted at high speed to faithfully convert the vibration waveform into digital data. To judge.

The result of the determination as to whether or not the knock has occurred is output to the I / O interface 71 of the sub-computer 42, and when the knock has occurred, the sub-computer 42 sends the main computer 41 through a serial line via the SCIs 70 and 52. The knock data is read in, and the main computer 41 immediately delays the ignition timing of the corresponding cylinder based on the knock data to avoid knock.

Reference numeral 81 is an air conditioner control unit for setting each control operation of the air conditioning system 91.
CPU 82, ROM 83, RAM 84, backup R
The AM 84a and the I / O interface 85 are connected via a bus line 86, and a stabilizing voltage is supplied to each part from a constant voltage circuit 88 connected to the battery 45 via an ignition switch 87.

An air conditioner control panel 89 including an air conditioner switch and an I / O interface 53 of the main computer 41 are connected to the input port of the I / O interface 80. The main computer 41 controls the air conditioner control unit 81. Required capacity for variable capacity air conditioner compressor 64 (C
ACDTY) signal is output.

Further, the output port of the I / O interface 85 is connected with a variable capacity control valve 111, which is a duty solenoid valve provided in the variable capacity air conditioner compressor 64, via a drive circuit 98, and the demand is met. The control signal corresponding to the capacity (CACDTY) signal is output, and the I
Connected to the input port of the / O interface 53,
A signal indicating whether the air conditioner switch is turned on is output.

Further, I of the air conditioner control unit 81
The input port of the / O interface 85 is connected to a solar radiation sensor 92 that detects a change in the amount of solar radiation and an outside air temperature sensor 93 that detects the outside air temperature, and the outlet temperature of an evaporator 94 provided in the air conditioning system 91 is set. An evaporator temperature sensor 95 for detecting and a heater core temperature sensor 97 for detecting the temperature of the heater core 96 through which the cooling water from the engine 1 flows are connected.

Further, the I / O interface 85 is used.
To the output port of the internal / external air switching servo motor 99, the relay coil of the blower relay 100 via the drive circuit 98,
The air mix servo motor 101, the outlet switching servo motor 102, the main fan relay 103 and the sub fan relay 104, and the switch display portions of the air conditioner control panel 89 are connected.

The inside / outside air switching servomotor 99 switches the air blown from the air outlet of the air conditioning passage 91a to either inside air, outside air, or both inside and outside air in response to a control signal from the air conditioner control unit 81.

Further, the contacts of the blower relay 100 are connected to the blower fan 105 provided in the air conditioning passage 91a, and the blower fan 105 is driven by the ON operation of the blower relay 100.

Furthermore, the above air mix servomotor 1
Reference numeral 01 controls the opening degree of the air mix dampers 106a and 106b by a control signal from the air conditioner control unit 81 to change the mixing ratio of warm air and cold air.

The air outlet switching servomotor 102 operates the differential damper 107a and the vent damper 107b in response to a control signal from the air conditioner control unit 81 to switch the air outlet.

The variable capacity air conditioner compressor 64 is
As shown in FIG. 13, the capacity is controlled by duty-controlling the variable capacity control valve 111 by a control signal (duty signal) from the air conditioner control unit 81. That is, the larger the duty ratio of the control signal for the variable displacement control valve 111, the more the solenoid coil 11
The exciting force due to 1a increases and the variable displacement control valve 111
Of the wobble chamber 113 due to a decrease in the amount of refrigerant leakage between the suction chamber 112 and the wobble chamber 113.
The internal pressure P _W is increased, and the wobble chamber pressure P _W acting on the rear surface of the piston 114 is increased relative to the discharge pressure and the suction output acting on the top surface of the piston 114, so that the piston 114 is stemmed. The inclination angle α of the wobble plate 116 supported via 115 becomes small, and the variable capacity air conditioner compressor 64 reduces the refrigerant discharge amount and the capacity.

Further, the smaller the duty ratio of the control signal, the larger the valve opening of the variable displacement control valve 111,
The amount of refrigerant leak in the wobble chamber 113 increases, and the piston 11
4, the wobble chamber pressure P acting on the back surface of the piston 114 relative to the discharge pressure and suction output acting on the top surface thereof.
_{As W} decreases, the inclination angle α of the wobble plate 116
Is increased, the refrigerant discharge amount of the variable capacity air conditioner compressor 64 is increased, and the capacity is increased.

[Operation] Next, the operation of the embodiment having the above configuration will be described.

(Variable capacity air conditioner compressor capacity control procedure) The control routine shown in FIG.
It is executed by the main computer 41 at a predetermined time interval. First, at step (hereinafter abbreviated as "S") 101, it is determined whether or not the air conditioner clutch relay 65 is ON by the control data. In case of, it progresses to S106. The ON / OFF of the air conditioner clutch relay 65 is set by an air conditioner clutch relay control procedure described later.

When it is judged that the air conditioner clutch relay 65 is ON and the routine proceeds to S102, it is judged whether the air conditioner switch provided on the air conditioner control panel 89 is ON or not based on the output signal of the air conditioner control unit 81,
When it is ON, it is determined that the air conditioner compressor 64 is driven, and the process proceeds to S103.

In S101 and S102, the energization status of the magnet clutch 64a of the variable capacity air conditioner compressor 64 is determined. That is, the air conditioner clutch relay 65 and the air conditioner clutch relay 65 do not operate at the same timing as ON / OFF of the air conditioner switch and ON / OFF of the air conditioner clutch relay 65 as shown in the air conditioner clutch relay control procedure described later and the time chart of FIG. It is necessary to determine the operating status of both switches.

Then, when proceeding from S102 to S103,
Cooling water temperature T _W and low temperature set value ACDT _W1 (for example, 10
(5 ° C.), and if T _W <ACDT _W1 , proceed to S108, and if T _W ≧ ACDT _W1 , proceed to S104.

In S104, the cooling water temperature T _W is compared with the medium temperature set value ACDT _W2 (for example, 107 ° C.), and T _W
<If ACDT _W2, the process proceeds to S109, where T _W ≧ ACDT _W2
In case of, it progresses to S105.

In S105, the cooling water temperature T _W is compared with the high temperature set value ACDT _W3 (for example, 109 ° C.), and T
_{When W} <ACDT _W3, the process proceeds to S110, where T _W ≧ ACDT
_{If W3,} the process proceeds to S111.

It should be noted that each of the above set values includes ACDT _W1 <A
There is a relationship of CDT _W2 <ACDT _W3 .

At S106 to S111, the required capacity (C) for the air conditioner compressor 64 is determined according to the driving condition of the air conditioner compressor 64 and the cooling water temperature T _W.
ACDTY: duty ratio) is set stepwise.

That is, when it is determined in S101 that the air conditioner clutch relay 65 is OFF and the process proceeds to S106,
Since the drive of the air conditioner compressor 64 is stopped,
Required capacity CAC for this air conditioner compressor 64
Set the latest required capacity CACDTY _NEW to the set value T in order to reduce the load when the compressor is re-driven by reducing DTY.
BACDY ₅ (for example, the duty ratio of 86%) is set at _{(CACDTY NE W ← TBACDY 5)} .

In this embodiment, the larger the duty ratio, the smaller the capacity of the air conditioner compressor 64.

In S102, the air conditioner switch is turned off.
When it is determined that F (however, the air conditioner clutch relay 65 is ON) and the routine proceeds to S107, the air conditioner clutch relay 65 is turned off after a predetermined delay time (elapsed time t _{3 to} t ₄ in FIG. 12, the details will be described later). ), The latest required capacity CACDTY _NEW is set at a setting value TBACDY ₄ (for example, 68%) with a slightly larger duty ratio (C
ACDTY _NEW ← TBACDY ₄ ).

Meanwhile, when the air conditioner clutch relay 65 has an air conditioner switch in ON, S102 is determined to ON at S101, since the air-conditioner compressor 64 is normally driven (the elapsed time t ₂ ~t ₃ in FIG. 12), S108 to S
At 111, the capacity of the air conditioner compressor 64 is set according to the cooling water temperature Tw to prevent engine overheating.

That is, when it is judged that T _W <ACDT _W1 in S103, the cooling water temperature T _W is in the range of substantially the set temperature, so in S108, the latest required capacity CACDTY is set so as to maximize the capacity of the air conditioner compressor 64. _NEW is set with the maximum value TBACDY (for example, a duty ratio of 14%) (CACDTY _NEW ← TBACDY).

If it is determined in S104 that T _W <ACDT _W2 (hence ACDT _W1 ≤T _W <ACDT _W2 ), in S109 the set value TBACDY ₁ (for example, 32%, which is slightly smaller than the maximum value TBACDY). ) To set (CACDTY _NEW ← TBACDY ₁ ).

Further, when it is determined in S105 that T _W <ACDT _W3 (hence ACDT _W2 ≤T _W <ACDT _W3 ), in S110, the engine load by the air conditioner compressor 64 is reduced because the cooling water temperature T _W is slightly high. Latest required capacity to prevent overheating CACDTY _NEW
Is a set value TBACDY ₂ (for example, 50
%) To set (CACDTY _NEW ← TBACD
Y ₂ ).

When it is determined in S105 that T _W ≧ ACDT _W3 , the cooling water temperature T _W is high, so that S111
Then, set the latest required capacity CACDTY _NEW to the minimum value TBA.
Set with CDY ₃ (for example, 68%) (CACDTYNE
W ← TBACDY ₃ ), prevent engine overheating.

Note that TBACDY <
TBACDY ₁ <TBACDY ₂ <TBACDY ₃ ≤T
There is a relationship of BACDY ₄ <TBACDY ₅ .

When the process proceeds from any of S106 to S111 to S112, the latest required capacity CACDTY _NEW set at each step is compared with the upper limit value MAX (for example, 95%), and CACDTY _NEW ≥MAX. In the case of S114, when CACDTY _NEW <MAX, the process proceeds to S113.

When the process proceeds to S113, the latest required capacity C
ACDTY _NEW and the lower limit value MIN (e.g., 5%) compared with the proceeds to S115 if the _{CACDTY NEW ≦ MIN, CACDTY NEW>} MIN ( thus, MAX ≧ CA
If CDTY _NEW > MIN), proceed to S116.

The steps S112 and S113 are provided to prevent the latest required capacity CACDTY _NEW from being set to an abnormal value due to the influence of noise or the like. Then, in S114, the required capacity CACDTY is set at the upper limit value MAX (CACDTY ← MAX). S11
In 5, the required capacity CACDTY is set at the lower limit value MIN (CACDTY ← MIN). In S116, the required capacity CA
Set CDTY with the latest required capacity CACDTY _NEW (CACDTY ← CACDTY _NEW ).

Then, in S117, the above S114 to S11 are performed.
The requested capacity CACDTY set in any one of 6 is set, transmitted to the air conditioner control unit 81, and the routine exits.

As shown in FIG. 2, the air conditioner control unit 81 outputs a control signal corresponding to the required capacity CACDTY to the variable capacity control valve 111 of the air conditioner compressor 64 at a predetermined timing and exits the routine. The control signal is output and held by a latch or the like until the next routine is executed.

(Control procedure for air conditioner clutch relay) FIG.
The flowchart shown in FIG. 5 is executed by the main computer 41 of the ECU 40 at predetermined time intervals. First, in S301, S303, and S304, the OFF condition of the air conditioner clutch relay 65 is determined.

In S301, the starter switch 61 is turned on.
If it is ON, it is determined that the OFF condition of the air conditioner clutch relay 65 is satisfied, and S302
The count value C after the starter is turned OFF for counting the elapsed time after the starter switch 61 is turned ON → OFF.
Set COUNT _ST with the setting value ACTIM ₁ (COUNT
_ST ← ACTIM ₁ ) and proceed to S340.

If it is determined in S301 that the starter switch 61 is OFF and the process proceeds to S303, the starter O
Determine whether the count value COUNT _ST after FF is 0,
When it is 0, it is determined that the OFF condition of the air conditioner clutch relay 65 is not satisfied, and the process proceeds to S304. When COUNT _ST ≠ 0, it is determined that the OFF condition is satisfied because the engine rotation is still unstable because the set time has not elapsed after engine start. Then S3
Go to 05 and count value COUNT after the starter is OFF
After subtracting _ST (COUNT _ST ← COUNT _ST -1),
Proceed to S340.

Then, when proceeding from S303 to S304, it is judged whether the air conditioner switch provided on the air conditioner control panel 89 is ON or not, and if it is ON, the process proceeds to S306, and if it is OFF, the process proceeds to S307.

When the operation proceeds to S306, the air conditioner switch is turned on →
The elapsed time after turning off timer operation flag FLAG _{AC OFF} is cleared (FLAG _{AC OFF} ← 0), and the process proceeds to S308.

At S308, the value of the throttle full-open region transition time count flag FLAG _TIMTH which is set to 1 within the set time after the throttle is fully opened is referred to, and FLA is set.
When G _{TI MTH} = 1, the process proceeds to S309, FLAG _TIMTH =
If 0, the process proceeds to S312.

In step S309, the count value COUNT _TH , which is counted up by the timer setting procedure described later and indicates the elapsed time after the throttle is fully opened, is compared with the set value TACC1. When COUNT _TH > TACC1, the set time after the throttle is fully opened has elapsed. If yes, go to S310 and _count ≤
When it is determined that the set time has not elapsed after the TACC1 throttle is fully opened and the engine is not yet stabilized, it is determined that the OFF condition of the air conditioner clutch relay 65 is satisfied, and the process proceeds to S340.

After proceeding to S310, after clearing the throttle full-open region transition time count flag FLAG _{TI MTH} (FLAG _TIMTH ← 0), at S311, the throttle full-open discriminating flag FLAG showing that the throttle is in the fully-open region.
Set _TH (FLAG _TH ← 1) and proceed to S312.

Then, from S308 or S311 to S
When proceeding to 312, the above-mentioned throttle full-open discrimination flag FLA
If it is determined that the throttle is fully open with FLAG _TH = 1 by referring to the value of G _TH , proceed to S313, and FLAG _TH
When = 0, the process proceeds to S314. When the process proceeds to S313, the throttle opening fully open region determination value ALPAC is set to the set value ALPACL.
Set at (for example, 60 °) (ALPAC ← ALPAC
L), the process proceeds to S315. Further, when the routine proceeds to S314, the throttle opening fully open region determination value ALPAC is set to the set value ALPAC.
H (however, ALPACH> ALPACL, eg 70
℃) (ALPAC ← ALPACH), S315
Go to.

As shown in FIG. 10, control hunting at the time of fully open region determination can be avoided by providing the throttle opening fully open region determination value ALPAC with hysteresis.

When the process proceeds from S313 or S314 to S315, the throttle opening TH is compared with the throttle opening fully open area determination value ALPAC, and TH>
When it is determined by the ALPAC that the throttle is fully open S3
16 and if TH ≦ ALPAC, proceed to S317 and clear the throttle fully open determination flag FLAG _TH (FLAG
After setting _TH ← 0), proceed to S319.

Further, when proceeding to S316, the value of the throttle full-open discrimination flag FLAG _TH is referred to, and FLAG _TH = 0.
In the case of, it is judged that it is the first routine after the throttle is fully opened, and S
Proceeding to 318, the throttle fully open region transition time count flag FLA for counting the elapsed time after fully opening the throttle.
After setting G _TIMTH (FLAG _TIMTH ← 1), S3
Proceed to 40.

Then, from S316 or S317 to S
Proceeding to 319, the air conditioner clutch relay 65 is currently O
Whether it is N or not is judged by the control data, and when it is OFF, S
If it is ON, the process proceeds to step S323.

When the process proceeds to S320, the condition of the air conditioner switch is judged from OFF → ON after the set time has elapsed, the value of the flag FLAG _{A / C} which is set to 1 is referred to, and if FLAG _{A / C} = 0, the process proceeds to S321. , FLA
If G _{A / C} = 1 then proceed to S323.

In step S321, the air conditioner switch OFF → ON elapsed time timer operating flag FLAG _ACON is set (FLAG _ACON to count the elapsed time after the air conditioner switch OFF → ON according to the timer setting procedure described later.
_ACON ← 1), proceed to S322. The count value COUNT _ACON and the set time ACEN, which are counted in the timer setting procedure described later and indicate the elapsed time after the air conditioner switch is turned off
Compare with T (equivalent to 0.3 sec, for example)
If T _ACON ≧ ACENT, turn off the air conditioner switch →
After turning on, it is determined that the set time has elapsed, the process proceeds to S323, and CO
If UNT _ACON <ACENT, it is determined that the time is within the set time, and the process proceeds to S340.

S319, S320, or S322
From S323 to S323, the air conditioner switch state determination flag FLAG _{A / C} is set (FLAG _{A / C} ← 1), and S32
_Go to step 4 and turn off the air conditioner switch → After turning on, clear the elapsed time timer operation flag FLAG _ACON (FLAG _ACON ←
After 0), the process proceeds to S333.

On the other hand, if it is determined in S304 that the air conditioner switch is OFF and the flow proceeds to S307, the air conditioner switch is turned OFF, and then the elapsed time timer operating flag FLAG
_ACON is cleared (FLAG _ACON ← 0), and the throttle fully open determination flag FLAG _TH is cleared in S325 (FLAG _ACON ← 0).
_TH ← 0), after clearing the throttle fully open region transition time count flag FLAG _TIMTH in S326 (FLAG
_TIMTH ← 0), the process proceeds to S327.

Then, in S327, it is determined whether the air conditioner clutch relay 65 is currently ON based on the control data. If it is ON, the process proceeds to S328, and if it is OFF, S340.
Go to. In S328, the value of the air conditioner switch state determination flag FLAG _{A / C} is referred to, and if FLAG _{A / C} = 1 (within the set time after turning ON _/ OFF the air conditioner switch) S32
9. If FLAG _{A / C} = 0, proceed to S340.

At S329, the air conditioner switch is turned ON → O.
Air conditioner switch O to count elapsed time after FF
N → OFF elapsed time timer operation flag FLAG _ACOFF
After setting (FLAG _ACOFF ← 1), proceed to S330.

In S330, the count value COUNT _ACOFF and the set time ACCLTM, which are counted in the timer setting procedure described later and indicate the elapsed time after the air conditioner is turned ON → OFF, are set.
(For example, 8 seconds equivalent) and compare, COUNT _ACOFF
If ≧ ACCLTM, proceed to S331, COUNT
_{If ACOFF} <ACCLTM, proceed to S333.

After proceeding to S331, after clearing the air conditioner switch state determination flag FLAG _{A / C} (FLAG _{A / C} ←
0), in S332, the flag FLAG _ACOFF for determining the elapsed time timer after turning the air conditioner switch ON → OFF is cleared (FLAG _ACOFF ← 0), and the process proceeds to S340.

Then, from S324 or S330 to S
At 333, the cooling water temperature determination flag FLAG _TW is set to 1 when the cooling water temperature is just before overheating.
Value is referred to, and if FLAG _TW = 1 then proceed to S334,
If FLAG _TW = 0, proceed to S335.

In S334, the cooling water temperature determination value ACCLTW indicating that the temperature is about to be overheated is set to the low temperature side set value A.
Set with CCLTWL (ACCLTW ← ACCLTW
L), the flow proceeds to S336, and in S335, the cooling water temperature determination value ACCLTW is set at the high temperature side set value ACCLTWH (ACCLTW ← ACCLTWH), and the flow proceeds to S336.

As shown in FIG. 11, control hunting at the time of determining the cooling water temperature can be avoided by providing the cooling water temperature determination value ACCLTW with hysteresis.

It should be noted that the low temperature side set value ACLCLTWL and the high temperature side set value ACCLTWWH are the high temperature set value AC in the above-mentioned variable capacity air conditioner compressor capacity control procedure.
For DT _W3 , ACDT _W3 <ACCLTWL <ACCL
There is a TWH relationship.

Then, when the flow proceeds to S336, the cooling water temperature T _W
And the cooling water temperature determination value ACCLTW are compared, and T _W <
In case of ACCLTW, the process proceeds to S337, and the cooling water temperature discrimination flag FLAG _TW is cleared (FLAG _TW ← 0) and then S33.
Proceed to 9. Further, if T _W ≧ ACCLTW, the cooling water temperature T
_If the cooling water temperature rises despite the reduction of the engine load by reducing the air conditioner compressor capacity with the increase of _W , proceed to S338 to set the cooling water temperature discrimination flag FLAG _TW in order to perform the air conditioning cutoff. (FLAG
_{After TW} ← 1), proceed to S340.

In S339, the air conditioner clutch relay 6
Set 5 to ON (A / C, CLH, RELAY ← O
N), exit the routine. Further, when the process proceeds to S340, the air conditioner clutch relay 65 is set to OFF (A /
C, CLH, RELAY ← OFF), exit the routine.

(Timer Setting Procedure) FIG. 6 is a flowchart for executing an interrupt every set time, and sets each of the above count values.

First, in S401, the value of the throttle fully open region transition time count flag FLAG _TIMTH is referred to
If AG _TIMTH ← 1, the process proceeds to S402, and the count value COUNT _{TH is} set to count the elapsed time after the throttle is fully opened.
Count up (COUNT _TH ← COUNT _TH +
1), the process proceeds to S404. In addition, in step S401, the FLAG
_{If TIMTH} ← 0, proceed to S403 and count value COU above
Clear NT _TH (COUNT _TH ← 0) and proceed to S404.

At S404, the air conditioner switch is turned off.
Refer to the value of the elapsed time after ON timer flag FLAG _ACON , and if FLAG _ACON = 1, proceed to S405 and count up the count value COUNT _ACON to count the elapsed time after turning off the air conditioner switch (ON
NT _ACON ← COUNT _ACON +1), proceed to S407. If FLAG _ACON = 0 in S404, the process proceeds to S406, and after the count value COUNT _ACON is cleared (COUNT _ACON ← 0), the process proceeds to S407.

At S407, the air conditioner switch is turned ON → O.
Referring to the value of the post-FF elapsed time timer operation flag FLAG _ACOFF , if FLAG _ACOFF = 1, proceed to S408
If LAG _ACOFF = 0, proceed to S409.

At S408, the count value COUNT _{ACOFF is} set to count the elapsed time after the air conditioner is turned on.
Count up (COUNT _ACOFF ← COUNT
_{ACOF F} +1), _exit the routine. Further, when the process proceeds to S409, after the count value COUNT _ACOFF is cleared (COUNT _ACOFF ← 0), the routine exits.

FIG. 12 illustrates a representative example of the operation of the air conditioner clutch relay 65 and the air conditioner compressor capacity setting procedure executed based on each of the above flow charts.

When the air conditioner compressor 64 is in the non-driving state, the required capacity CACDTY for this air conditioner compressor 64 is set to the low capacity TBACDY _5. First, when the air conditioner switch provided on the air conditioner control panel 89 is turned on, the timer routine is started. Is started (elapsed time t ₁ ).

Then, the set time ACENT (for example, 0.
After 3 seconds), the air conditioner clutch relay 65 is turned on and the required capacity CACD of the air conditioner compressor 64 is reached.
TY is set according to the cooling water temperature T _W (elapsed time t ₂ ).

By the way, the air conditioner compressor 64
However, even if the required capacity CACDTY is output, the capacity of the air conditioner compressor 64 does not immediately increase from the low capacity TBACDY ₅ , but the wobble plate 116 (see FIG. 13) tilts as shown by the broken line in the figure. There is a response delay (for example, 5 to 6 seconds) until the predetermined capacity is reached.

If the air conditioner switch is turned off,
The air conditioner clutch relay 65 does not turn off immediately, and the required capacity CAC for the air conditioner compressor 64
DTY is set to the medium capacity TBACDY ₄ side (elapsed time t ₃ ). At this time as well, similarly to the above, the capacity of the air conditioner compressor 64 is gradually reduced to a predetermined capacity with a certain response delay.

After the air conditioner switch is turned off, the air conditioner clutch relay 65 is turned off after a set time ACCLTM (for example, 8 sec) has elapsed, and the required capacity CACDTY for the air conditioner compressor 64 is set to the low capacity TBACDY ₅ again ( Elapsed time t ₄ ).

In this way, the air conditioner switch is turned off → O
At N hours (elapsed time t ₁ ), the air conditioner compressor 64
The required capacity CACDTY for the
_{Since 5} is given and the capacity CACDTY is started after the set time ACENT has passed, the capacity CACDTY of the air conditioner compressor 64 can be gradually started. At this time, the required capacity is accompanied by a response delay. The capacity corresponding to CACDTY is reached.

As a result, the load on the engine by the air conditioner compressor 64 is not abruptly applied, and the temporary drop in engine speed (engine speed fluctuation) as indicated by the broken line in FIG. 12D is eliminated. This is particularly effective when the engine load of the air conditioner compressor 64 is relatively large and the engine is idle.

When the air conditioner switch is turned ON → OFF (elapsed time t ₃ ), the required capacity CACDTY for the air conditioner compressor 64 is not suddenly set to 0, but the air conditioner clutch relay 65 is kept in the ON state until the set time ACCLTM elapses. Since the required capacity CACDTY at this time is set to the set capacity TBACDY ₄ , and then the air conditioner clutch relay 65 is turned off and the required capacity CACDTY is set to the set capacity TBACDY ₅ , the capacity of the air conditioner compressor 64 is Gradually decreases. As a result, the load on the engine by the air conditioner compressor 64 does not decrease suddenly, and as shown by the broken line in FIG. Fluctuation) disappears.

[0120]

As described above, according to the present invention,
The effects listed below are achieved.

1) As described in claim 1, if the capacity of the variable capacity air conditioner compressor is decreased in accordance with the increase of the engine temperature, the load on the engine is reduced according to the temperature of the cooling water, and the overheat is caused. Can be avoided in advance.

2) As described in claim 2, when the variable capacity air conditioner compressor is driven after the set time has elapsed after the air conditioner switch is turned on, and thereafter the air conditioner capacity is increased from the low capacity to the normal capacity, The load on the engine due to the air conditioner compressor is not suddenly applied, and it is possible to prevent the engine speed from dropping.

3) As described in claim 3, the air conditioner compressor is stopped after the set time has elapsed after the air conditioner switch is turned off, and the air conditioner capacity is reduced to the low capacity side until the air conditioner compressor is stopped. By doing so, it is possible to avoid a sudden decrease in the load on the engine when the air conditioner compressor is deactivated, and to prevent the engine speed from rising.

[Brief description of drawings]

FIG. 1 is a flowchart showing a capacity control procedure of a variable capacity air conditioner compressor.

FIG. 2 is a flowchart showing a control signal output procedure for a variable capacity air conditioner compressor.

FIG. 3 to FIG. 5 are flowcharts showing the procedure of the air conditioner clutch relay.

[Fig. 4] Same as above

[FIG. 5] Same as above

FIG. 6 is a flowchart showing a timer setting procedure.

FIG. 7 is a schematic diagram of an engine.

8 and 9 are configuration diagrams of a control device.

[FIG. 9] Same as above

FIG. 10 is an explanatory diagram showing hysteresis of a throttle fully open region determination flag.

FIG. 11 is an explanatory diagram showing hysteresis of a cooling water temperature determination flag.

FIG. 12 is a time chart of an air conditioner clutch relay, an air conditioner compressor capacity, and an engine speed when the air conditioner switch is turned on and off.

FIG. 13 is a schematic diagram of a variable capacity air conditioner compressor.

[Explanation of symbols]

64: Variable capacity air conditioner compressor T _W : Engine temperature (cooling water temperature)

Claims (3)

[Claims] 1. A procedure for detecting whether or not a variable capacity air conditioner compressor is in operation, and an engine temperature is detected when the variable capacity air conditioner compressor is in operation, and the variable capacity air conditioner is increased as the engine temperature increases. And a procedure for reducing the capacity of the compressor. 2. A procedure for detecting whether or not the air conditioner switch is on, a procedure for driving the variable capacity air conditioner compressor after a set time has elapsed after the air conditioner switch is turned on, and an air conditioner capacity from when the variable capacity air conditioner compressor is driven. And a procedure for increasing the capacity from a low capacity to a normal capacity. 3. A procedure for detecting whether or not the air conditioner switch is on, a procedure for stopping the variable capacity air conditioner compressor after a set time has elapsed after the air conditioner switch is turned off, and a function for changing the variable capacity air conditioner compressor after the air conditioner switch is turned off. Until then, there is provided a procedure for reducing the capacity of the air conditioner to the low capacity side.