JP2635379B2 - Output control device for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an output control device for an internal combustion engine, and more particularly to a control device that appropriately controls output torque in accordance with the operation of a variable displacement compressor driven by the engine.

(Prior Art) As a conventional output control device for an internal combustion engine, an intake air amount is feedback-controlled with respect to a target idle speed in order to maintain a desired target aisle speed during idle operation of the engine, and the engine is driven by the engine. In order to obtain the target idle speed according to the operating state even during operation of the air-conditioning variable displacement type compressor that acts as an engine load, the intake air amount is determined according to the operating state of the compressor. The control is already proposed by the present applicant (Japanese Patent Application No. 63-63).
No. 099764).

(Problems to be Solved by the Invention) However, the control device proposed above sets an intake air amount according to the load torque of the compressor when applied in an operating region of the engine other than the idle operation, There was room for improvement in properly controlling the engine output torque.

That is, in general, the load applied to the engine to drive a variable displacement type compressor (hereinafter simply referred to as “load torque”) is variable according to the operating state of the compressor, for example, the compressor is variable in accordance with the stroke of the piston. These types have characteristics that change according to the stroke and discharge pressure of the piston and are almost proportional to the engine speed. Therefore, even when the operation state of the compressor changes under the same condition, when the engine speed is different, the amount of change in the load torque at the time of the change is different, and the load torque is larger as the engine speed is larger.

On the other hand, the above-mentioned proposed technique aims at idle speed control according to the operation of the compressor, that is, assuming a condition that the engine speed is constant, so that only the piston stroke and the discharge pressure are used as parameters. An increase value of the intake air amount during the operation of the compressor is set, and the increase value is set to a smaller value suitable for maintaining the idle speed.

Therefore, when the above technology is applied when the engine is operated in a higher rotation speed region other than the idling operation region, the amount of intake air that is increased during the operation of the compressor is insufficient, and thus the output torque of the engine is insufficient. Resulting in. As a result, a torque shock is generated particularly at the start of operation of the compressor or at the time of control for increasing the capacity, and abnormal fluctuations in the engine speed are caused. Inconvenience such as becoming occurs.

The present invention has been made in order to solve the above-described problems of the conventional technology, and according to the operation state of a variable displacement type compressor and over the entire range of the engine speed,
An object of the present invention is to provide an output control device for an internal combustion engine that can appropriately control the output of the engine and thereby prevent occurrence of torque shock and abnormal fluctuation of the engine speed.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a compressor driven by an internal combustion engine of a vehicle and having a variable capacity, and the internal combustion engine being operated in accordance with the operation of the compressor. In an output control device for an internal combustion engine including output increase correction means for maximally correcting the output torque of the engine, a load torque detection means for detecting a load torque of the compressor, a rotation speed detection means for detecting an engine rotation speed, Increasing value setting means for setting an output increasing value of the output increasing correcting means in accordance with outputs of the load torque detecting means and the rotational speed detecting means, wherein the increasing value setting means increases the output as the engine speed increases. Set the value to a larger value.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an overall configuration diagram of a fuel supply control device including an output control device according to the present invention, that is, an intake air amount control device.
Reference numeral 1 denotes, for example, a four-cylinder four-cycle internal combustion engine, to which an intake pipe 2 and an exhaust pipe 12 are connected. A throttle body 3 is provided in the middle of the intake pipe 2, and a throttle valve 3 'is provided therein. A throttle valve opening sensor (hereinafter referred to as “θ _TH sensor”) 4 is connected to the throttle valve 3 ′ to convert the valve opening of the throttle valve 3 ′ into an electric signal, and an electronic control unit (hereinafter “ECU”) is provided. 5).

A fuel injection valve 6 is provided in the intake pipe 2 between the engine 1 and the throttle body 3. This fuel injection valve 6 is provided for each cylinder slightly upstream of an intake valve (not shown) of the intake pipe 2, and each injection valve is connected to a fuel pump (not shown) and electrically connected to the ECU 5, The valve opening time of fuel injection is controlled by a signal from the ECU 5.

The fuel injection valve 6 and the throttle body 3 of the intake pipe 2
An air passage 17 communicating between the inside of the intake pipe 2 and the atmosphere is provided therebetween. An air cleaner 18 is attached to an open end of the air passage 17 on the atmosphere side, and an auxiliary air amount control valve 19 is arranged in the air passage 17. This auxiliary air amount control valve 19
Is a normally closed proportional solenoid valve, a valve body 19a capable of continuously changing the opening area of the air passage 17, a spring 19b for urging the valve body 19a in a valve closing direction, and the valve body when energized. An electromagnetic solenoid 19c for moving the valve 19a in the valve opening direction against the urging force of the spring 19b. The auxiliary air amount control valve 1
The current supplied to the solenoid 19c of the ninth is controlled by the ECU 5 so that the valve opening area is set according to the operating state and load state of the engine.

Further, between the fuel injection valve 6 and the air passage 17 of the intake pipe 2, an intake pipe absolute pressure sensor (hereinafter referred to as “P _BA
A sensor 8) is provided, and the absolute pressure signal converted into an electric signal by the _PBA sensor 8 is supplied to the ECU 5.

An engine cooling water temperature sensor (hereinafter referred to as “Tw sensor”) 10 is provided in the main body of the engine 1. The Tw sensor
Reference numeral 10 denotes a thermistor or the like, which is inserted into the peripheral wall of the engine cylinder filled with cooling water and supplies a detected water temperature signal to the ECU 5. Further, an engine speed sensor (hereinafter, referred to as “Ne sensor”) 11 as a speed detecting means is mounted around a camshaft or a crankshaft (not shown) of the engine 1. The Ne sensor 11 is located at a predetermined crank angle position every 180 ° rotation of the crankshaft of the engine 1, that is, at a crank angle position that is a predetermined crank angle before the top dead center (TDC) at the start of the intake stroke of each cylinder. Signal pulse (hereinafter referred to as “TDC signal pulse”),
This TDC signal pulse is sent to ECU5.

A compressor 20 that compresses a refrigerant for air conditioning is connected to the engine 1. The compressor 20 is of a variable displacement type swing plate type. That is, the drive shaft 21 of the compressor 20 and the rotating member 22 provided integrally with the
It is connected to the engine 1 via a pulley 23, a pulley 24 and an electromagnetic clutch 25. An inclined surface 22a is formed on the rotating member 22 on the side opposite to the drive shaft 21, and the rocking plate 26 is rotatably abutted on the inclined surface 22a while being biased by a spring 27.
A piston 28 is connected to the oscillating plate 26 via a rod 27, and the piston 28 reciprocates in the cylinder 29 to suck and compress the refrigerant. That is, the electromagnetic clutch
When the engine 25 is connected, the rotation of the engine 1 is controlled by the drive shaft 21 and the rotating member.
After being transmitted to the cylinder 22 and converted into a reciprocating motion of the swinging plate 26 and the piston 28, the refrigerant sucked into the cylinder 29 through a suction chamber (not shown) is compressed, and then is shown through a discharge chamber 30. Not discharged to the condenser. In addition, rocking plate
The inclination angle of 26 is controlled according to the balance between the suction pressure and the discharge pressure Pd, whereby the stroke _FSTR of the piston 28, that is, the capacity of the compressor 20, is controlled.

The tilt angle of the swing plate 26, that is, the stroke _{FSTR of the} piston 28 is detected. A stroke sensor 31 (hereinafter referred to as “ _FSTR sensor”) as load torque detecting means is connected, and supplies a detection signal to the ECU 5. The pressure of the inside thereof to the discharge chamber 30, i.e. PD ₁ switches 32 and PD ₂ switch 33 for detecting a delivery pressure Pd (load torque detecting means) is provided. For the former 32, the discharge pressure Pd is the first
The switch 33 is turned on when the predetermined pressure PD ₁ (for example, 9 kg / cm ² ) is higher than the first predetermined pressure PD _1.
A switch that is turned on when the pressure is larger than a _second predetermined pressure PD ₂ (for example, 14 kg / cm ² ), and these on-off signals are supplied to the ECU 5. Further, an ECU 5 is connected to an electromagnetic clutch 25, and is connected to an air conditioner (HAC) switch 34 which is turned on when the compressor 20 is operated by the engine 1, and supplies an on-off signal thereof.

The ECU 5 shapes input signal waveforms from various sensors, corrects a voltage level to a predetermined level, and converts an analog signal value to a digital signal value. The input circuit 5a has a function of a central processing unit (hereinafter referred to as a “CPU”). 5b, a storage means 5c for storing various calculation programs executed by the CPU 5b, calculation results, and the like, an output circuit 5d for supplying drive signals to the auxiliary air amount control valve 19 and the fuel injection valve 6, and the like. .

That is, in this embodiment, the ECU 5 constitutes output increase correction means and increase value setting means.

The CPU 5b responds to the various engine parameter signals described above,
The operation state of the engine 1 is determined, and the valve opening command value ICMD of the auxiliary air amount control valve 19 is calculated in synchronization with the TDC signal pulse according to the determined engine operation state and the operation state of the compressor 20, and the like. A drive signal based on the valve opening command value ICMD is supplied to the auxiliary air amount control valve 19 via the output circuit 5d.
To the electromagnetic solenoid 19c.

The CPU 5b determines the operating state of the engine 1 based on a control program (not shown) according to the various engine parameter signals described above, and synchronizes the fuel injection valve 6 with the TDC signal pulse according to the determined engine operating state. calculated based on the following equation (1) the fuel injection time T _OUT to be opened, and supplies a drive signal based on the calculation result to the fuel injection valve 6.

T _OUT = Ti × K ₁ + K ₂ (1) Here, Ti indicates the basic fuel injection time of the fuel injection valve 6 and is determined according to, for example, the intake pipe absolute pressure _PBA and the engine speed Ne.

K ₁ and K ₂ are other correction coefficients and correction variable computed according to various engine parameter signals, such as fuel consumption characteristic according to engine operating conditions, the optimization of various properties such as the acceleration characteristics can be achieved Set to the required value.

FIG. 2 shows a flowchart of a subroutine for calculating the valve opening command value ICMD. This program is executed every time the TDC signal pulse is generated.

First, the stroke of the piston 28 (hereinafter, simply referred to as "stroke") reads the F _STR and the engine speed Ne (step 201). Next, first to third predetermined values IHAC, IHACAC and IHACDC which are applied as described later to set the air conditioner load term IHACn of the valve opening command value ICMD are calculated (step 202).

FIG. 3 shows a flowchart of a subroutine for performing this calculation. First, in step 301, the first to third predetermined values IHAC, IHACAC and IHACDC are stored in a table stored in the storage means 5c, respectively, in step 20 of FIG.
Search according to the stroke F _STR read in 1.

FIG. 4 shows this table, wherein the first and second predetermined values IHAC and IHACAC are set to positive values, and the third predetermined value IHACDC is set to negative values. Further, the absolute value of any given value is set to be larger as the stroke _FSTR is larger. This is because the load torque is equal to the stroke F _STR except when the stroke F _STR is near the full stroke.
This is because the intake air amount is set in accordance with such a load torque characteristic because it is almost proportional to _STR .

Furthermore, the second predetermined value IHACAC is set to a larger relationship to the first compared to a predetermined value IHAC, same stroke F _STR. More specifically, with respect to five criteria value F _{STR 1} to F _STR5 stroke F _STR (e.g., 5,20,50,80% of full stroke respectively), IHAC value fully opened opening 3,5,8
And 10%, and IHACAC values were similarly 4,6,10 and 12%,
DC values are similarly set to -4, -6, -9, and -10%, respectively, and between the reference values are obtained by interpolation calculation.

Returning to FIG. 3, in a step 302 following the step 301, the engine speed correction coefficient K _NAC is calculated from a table stored in the storage means 5c in accordance with the engine speed Ne read in the step 201 in FIG. Search for. FIG. 5 shows this table, and the rotation speed correction coefficient K _NAC is set to a larger value as the engine rotation speed Ne is larger. More specifically, the first to third reference values N _{NAC1 to} N _NAC3 (for example, 1,000, 1,500, 2,000
0 rpm) is set, and the engine speed correction coefficient K _NAC is set to the first predetermined value K _NAC1 (for example, 1.0) which is the smallest when the engine speed Ne is _{equal to} or less than the first reference value N _NAC1 . When the reference value _NAC2 is 2, a second value larger than the K _NAC1 value is used.
To the predetermined reference value K _NAC2 (for example, 2.0).
When it is _{equal to} or greater than _NAC3 , it is set to a third predetermined value K _NAC3 (for example, 3.0) which is _larger than the K _NAC2 value, and is obtained by interpolation between the reference values.

Returning to FIG. 3, in step 303 following step 302, the first and third
The predetermined values of IHAC, IHACAC and IHACDC and the step 302
The rotational speed correction coefficient K _NAC found by is calculated by the following equation (2),
Applying (3) and (4), these predetermined values IHAC, IHA
Calculate CAC and IHACDC.

IHAC = K _NAC × IHAC (2) IHACAC = K _NAC × IHACAC (3) IHACDC = K _NAC × IHACDC (4) IHAC value, IHACAC value and IHA calculated as described above
As will be described later, the CDC value is calculated during the steady-state operation of the compressor 20, immediately after the start of operation, and immediately after the stop of operation, by the air conditioner load item.
In addition to being set as IHACn, the air conditioner load term IHACn is applied as an addition term of the valve opening command value ICMD. Therefore, the intake air amount is set not only by the stroke _FSTR but also by the engine speed Ne as a parameter in accordance with the operation / stop of the compressor 20, so that the output torque of the engine 1 is adjusted in accordance with the change in the load torque. Control, torque shock and engine speed.
Ne fluctuation can be prevented.

In addition, the rotation speed correction coefficient K _NAC is set as described above based on the table of FIG.
The predetermined values IHAC, IHACAC and IHACDC are corrected to a larger value as the engine speed Ne is larger, so that the increase / decrease of the intake air amount due to the operation / stop of the compressor 20 is controlled to a larger value. The intake air amount can be controlled so as to match the above-described characteristic that the torque is substantially proportional to the engine speed Ne, and thus the output torque of the engine 1 can be more appropriately controlled.

Returning to FIG. 2, in step 203 following step 202, it is determined whether or not the HAC switch 34 is on, and whether or not the compressor 20 is being driven by the engine 1 immediately. If yes), HAC switch
It is determined whether or not 34 is turned on for the first time this time (step 204). When the answer is affirmative (Yes), the air conditioner load term IHACn is set to the second predetermined value IHACAC (the sixth predetermined value IHACAC).
At time t _{A in the} figure, the process proceeds to step 210 described later. That is, the air conditioner load term IHACn is set to a larger value IHACAC immediately after the electromagnetic clutch 25 of the compressor is engaged and the engine 1 is connected to the compressor 20 in synchronization with the ON of the HAC switch 34. . With such a setting, it is possible to increase the intake air amount in response to the increase in the engine load due to the connection with the compressor 20, and to prevent a decrease in the engine speed.

If the answer in step 204 is negative (No), that is, the HAC switch
If 34 is already on before the last time,
The last term IHACn- ₁ of the air conditioner load term is the first predetermined value IHA
It is determined whether it is larger than C (step 206). If this answer is affirmative (Yes), that is, if IHACn _-1 > IHAC is satisfied, the current term IHACn of the air conditioner load term is set to a difference obtained by subtracting a predetermined value ΔIHACAC (for example, 0.1%) from the previous value IHACn ₋₁ ( Step 207), negation (No), that is, IHACn ₋₁ ≦ IHAC
Is established, the current value IHACn of the air conditioner load term is set to the first predetermined value IHAC (step 208), and the flag FF
After setting BHAC to the value 1 (step 209), the process proceeds to step 210 described later. This flag F.FBHAC is the HAC switch 34
Is in the off state, the value is set to 0 in step 231 described later.

Thus, immediately after the HAC switch 34 is turned on, the second
The air conditioner load term IHACn set to the predetermined value IHACAC of
As long as the AC switch 34 keeps on being gradually decreased (Figure 6 time t _A ~t _B), after the start of operation of the compressor 20 after reaching the first predetermined value IHAC, the predetermined time period has elapsed, with feedback control is held by the IHAC value as being in a stable state, flag F.FBHAC is set to the value 1 (Figure 6 time t after _B).

In step 210, it is determined whether or not the PD ₁ switch (SW.) 32 is in the ON state, that is, the discharge pressure Pd is equal to the first predetermined pressure.
PD ₁ is determined is larger than or not. This answer is affirmative (Yes)
In the case of, it is further determined whether or not the flag F.FBHAC is set to the value 1 (step 212). When the answer is affirmative (Yes), the current value IAIn of the integral control term of the valve opening command value ICMD is changed from the previous value IAIn _-1 to the first increase value IHACSU.
Set B ₁ to the value obtained by subtracting (step 213), the process proceeds to step 214 which will be described later. Either is negative answer to the question of the step 211 or 212 (No), i.e., when the PD ₁ 32 is already turned on from a previous last or when the flag F.FBHAC is set to the value 0, the step The process directly proceeds to step 214 without executing step 213. As described above, the execution of the step 213, i.e. subtracts the first maximum value IHACSUB ₁ from the integral control term IAIn is, HAC switch 34 in a case where the PD ₁ switch 32 is turned on from the OFF state It is executed only when the feedback control after being turned on is in a stable state.

In step 214, it is determined whether or not the PD ₂ switch (SW.) 33 is in the ON state, that is, the discharge pressure Pd is equal to the second predetermined value.
It is determined whether it is greater than PD ₂ (> PD ₁ ). When the answer is affirmative (Yes), that is, when the compressor 20 is in the extremely high discharge pressure state, the PD ₂ switch 33 is turned on for the first time this time (step 215) and the flag F.FBHAC is set to a value of 1. It is determined whether or not there is (step 216). When the answer to both steps is affirmative (Yes), the current value IAIn of the integral control term is changed from its previous value IAIn _-1 to a second increase value IHACSUB ₂ (> IHACSUB ₁ ) and the first increase value IHACSUB. minus the difference between _1, IAIn _-1 - (IHACSU
After setting B ₂ -IHACSUB ₁ ) (step 217), if either of the answers in the above steps 215 or 216 is negative (No), the process directly proceeds to step 218 described later. Subtract the increase value IHACSUB ₁ from the second increased value IHACSUB ₂ first in step 217 is because the increase value IHACSUB ₁ of the first is subtracted already from the integral control term IAIn in step 213 .

In step 218, an increase term IHACSUB for the high discharge pressure of the compressor 20 (hereinafter simply referred to as "increase term") is set to a _second increase value IHACSUB2. Then, the integral control term IA
The learning value _IXREF of In described later is held at the value obtained up to the previous time (step 219). Further, the steps 205, 207 or
The current value IHACn of the air conditioner load term obtained in 208 and the increase value IHACSUB set in step 218 are applied to the following equation (5) to calculate the valve opening command value ICMD, and the program ends.

ICMD = IAIn + IHACn + IHACSUB + Ix (5) Here, Ix is a correction term set according to the power generation state of an AC generator (not shown), a target engine speed set according to the engine coolant temperature Tw and the like, and an actual engine speed Ne. And a correction term corresponding to an actual change in the engine speed Ne, and the like.

If the answer in step 214 is negative (No), that is, PD ₁ <Pd ≦ PD
₂ is satisfied, and therefore, when the compressor 20 is in the high discharge state, the PD ₂ switch 33 is turned off for the first time this time (step 221) and the flag F.FBHAC is set to 1
Is determined (step 222). When the answer to both steps is affirmative (Yes), the current value I
AIn is a value obtained by adding the difference (IHACSUB ₂ −IHACSUB ₁ ) between the first and second increase values to the previous value IAIn ₋₁ , IAIn ₋₁ + (IHAC
SUB ₂ -IHACSUB ₁ ) (step 223), and when either of the above steps is negative (No),
Proceed to step 224. In this step 224, the increase term IHACSU
B is set to the _first increase value IHACSUB1, and then the steps from step 219 are executed to end the program.

If the answer to step 210 is negative (No), that is, if Pd ≦ PD ₁ is satisfied and the compressor 20 is not in the high discharge pressure state, then the PD ₁ switch 32 is turned off for the first time (step 225). And whether the flag F.FBHAC is set to the value 1 (step 222). When the answer to both steps is affirmative (Yes), the current value IAIn of the integral control term is set to a value obtained by adding the first increase value IHACSUB1 to the previous value IAIn _-1 (step 227). Either of the above two steps is negative (No)
If so, go directly to step 228. This step 228
Then, the increase term IHACSUB is set to the value 0.

As described above, the increase term IHACSUB is set to the value 0 when the PD ₁ switch 32 is off, that is, when Pd ≦ PD ₁ is satisfied and the compressor 20 is not in the high discharge pressure state (step 22).
8) When the PD ₁ switch 32 is on and the PD ₂ switch 33 is off, that is, when PD ₁ <Pd ≦ PD ₂ is satisfied and the compressor 20 is in the high discharge pressure state, the first increase value IH
In ACSUB ₁ (step 224), when the PD ₂ switch 33 is ON, that is, when Pd> PD ₂ is satisfied and the compressor 20 is in the extremely high discharge pressure state, the second increase value IHACSUB ₂ is set (step 218). ) Are set, and are applied as the addition term of the valve opening command value ICMD in the equation (5) (see FIG. 6).

On the other hand, when the stroke _FSTR is near the full stroke, the load torque of the engine 1 increases as the discharge pressure Pd increases as the pressure applied to the piston 28 of the compressor 20 increases. Therefore, as described above, the load torque according to the discharge pressure Pd is set in accordance with the on / off state of the PD ₁ and PD ₂ switches 32 and 33, that is, by setting the increase term IHACSUB to be larger as the discharge pressure Pd is larger. Thus, an appropriate amount of intake air can be supplied in accordance with the increase in the engine output, and appropriate engine output control can be performed.

In this case, immediately after the on / off switching of the PD ₁ switch 32 or the PD ₂ switch 33, the steps 211 to 213 are performed.
As is clear from 215 to 217, 221 to 223 and 225 to 227, when the flag F.FBHAC is set to the value 1, the integral control term I
AIn is set to offset the increased value IHACSUB, the valve opening degree command value so applied to the equation (5) ICMD is not substantially changed (in FIG. 6 (d), the time tc~t _D) . If the rotation speed feedback control is continued when the predetermined time has elapsed after the operation of the compressor 20 and the increase correction is in a stable state, the integral control term IA for performing this feedback is provided.
In, proportional control terms etc. have already been increased to prevent a decrease in the number of revolutions that occurs with the gradual increase in the discharge pressure of the refrigerant,
If the increase correction is performed in synchronization with the turning on of the PD ₁ switch 32 or the PD ₂ switch 33 in this state, the increased amount of air becomes an excessive supply amount, which causes a temporary increase in the engine speed. become. Therefore, by reducing the integral control term of the feedback that has increased with the increase of the discharge pressure Pd as described above, the compressor 20
Can be excluded from the feedback term, so that even if the discharge pressure Pd increases, overshoot due to a large increase in the intake air amount can be prevented, and the stability of the rotation speed control can be improved. Conversely, when the discharge pressure Pd decreases, it is possible to prevent an abnormal decrease in the engine speed due to a large decrease in the intake air amount, and similarly to improve the stability of the control.

On the other hand, in the above-described case, when the flag F.FBHAC is set to the value 0, the integral control term IAIn is maintained at the previous value, so that the valve opening degree command value ICMD is immediately increased or decreased by the increase term IHACSUB ( (D) of FIG. 6, times t _G and t _H ). Thus, shortly after the operation of the compressor 20, if the discharge pressure Pd increases or decreases in a state where the increase correction control is not stable,
The amount of intake air can be immediately increased or decreased, and thus the responsiveness of control can be increased.

In step 229 following step 228, the stroke
A predetermined value F _{STRH in which} F _STR is larger than a predetermined value F _{STRL which} is low and higher than F _STRL
It is determined whether it is within a smaller predetermined range. When this answer is affirmative (Yes), that is, when F _STRL <F _STR <F _STRH holds, the learning term I _XREF which is set as the initial value of the integral control term IAIn at the start of the feedback control is expressed by the following equation (6).
(Step 230), and the process proceeds to Step 220.

Here, A is a constant, C _REF is a weighting factor set by a subroutine (not shown), and _IXREF ′ is a learning value obtained up to the previous time. As is clear from the above equation (6),
The weight coefficient C _REF determines the weight of the current value IAIn of the integral control term in the calculation of the learning value _{IXREF, and} the value sets the weight of the current value IAIn of the integral control term, that is, the calculation speed of the learning value _IXREF. Is done.

If the answer to step 229 is negative (No), that is, F _STR ≧ F _STRH
Alternatively, when F _STR ≦ F _STRL is satisfied, the above-mentioned step 219 and _subsequent steps are executed, and this program is terminated.

The predetermined value F _STRH is, for example, 6
Set as 5%. In the region equal to or less than the predetermined value F _STRH, the load torque of the compressor 20 is substantially obtained only by the stroke F _{STR, and} the load torque has already been added as an addition term.
Since the external load of the engine is removed from the integral control term IAIn without affecting the load of the compressor in the feedback control term, the integral control term IAIn contains the amount of intake air required under no load. It is a corresponding value.

Therefore, as described above, the calculation of the learning value I _XREF
By performing only when the stroke F _STR is smaller than the predetermined value F _STRH , it is possible to prevent a large fluctuation of the learning value _IXREF ,
This can be calculated to an appropriate value.

On the other hand, the stroke F _STR is not linear with respect to the output of the actual stroke of the F _STR sensor 31 at a predetermined value F _STRL smaller area. Therefore, since not be obtained an appropriate learning value I _XREF from the integral control term Iain, not calculated learned value I _XREF even when the F _STR ≦ F _STRL.

If the answer in step 203 is negative (No), that is, the HAC switch
When the compressor 34 is in the OFF state and the compressor 20 is in the stopped state, the flag F.FBHAC is set to a value of 0 (step 231), and then it is determined whether or not the HAC switch 34 is in the OFF state for the first time (step 231). Step 232). If the answer is affirmative (Yes), the current value IHACn of the air conditioner load term is set to the third predetermined value IHACDC (step 2).
33), proceed to step 228 and subsequent steps. Immediately after the HAC switch 34 is switched from the on state to the off state, the current value IHACn of the air conditioner load term is changed to the third predetermined value I which is a negative value.
The reason for setting the HACDC is to subtract the residual air since the intake air remains in the intake pipe immediately after the switching.

If the answer in step 232 is negative (No), that is, the HAC switch
If 34 is in the OFF state before the previous time, it is determined whether the previous value IHACn- ₁ of the air conditioner load term is smaller than 0 (step 234). This answer is affirmative (Yes), that is, IHAC
When n ₋₁ <0 holds, the current value I of the air conditioner load term
HACn is changed to its previous value IHACn- ₁ by a predetermined value ΔIHACDC (for example,
0.05%) (step 235),
If not (No), that is, if IHACn ₋₁ ≧ 0 is satisfied, the current value IHACn of the air conditioner load term is set to a value of 0 (step 236), and the process proceeds to step 228 and subsequent steps. HAC like this
The IHACn of the air conditioner load term when the switch 34 is off is
Immediately after switching to the off state, a third predetermined value IHAC
Is set to DC, then after this value has been gradually increased, is set to a value 0 (in Figure 6 the time t _E ~t _F, etc.).

In the above embodiment, the load torque is detected based on the stroke of the compressor and the discharge pressure.
The present invention is not limited to this, and the detection may be performed using another parameter that reflects the load torque.

Further, in the above-described embodiment, an example in which the output torque of the engine is controlled by the intake air amount has been described. However, the present invention is not limited to this. Control of the engine output by other methods, such as fuel supply control and ignition timing control Of course, it is also possible to make them.

(Effects of the Invention) As described above in detail, according to the present invention, the output increase value for increasing and correcting the output torque of the internal combustion engine having the variable displacement type compressor is determined by the load torque of the compressor and the engine speed. Set according to. Especially,
Since the output increase value is set to a larger value as the engine speed is larger, it is required to be adapted to a characteristic that the load torque of the compressor is larger according to the operation state of the compressor and the engine speed is larger. The engine output can be appropriately controlled over the entire range of the engine speed so as to match the torque, so that occurrence of torque shock, abnormal fluctuation of the engine speed, and the like can be prevented.

[Brief description of the drawings]

1 is an overall configuration diagram of a fuel supply control device including an output control device according to the present invention, FIG. 2 is a flowchart of a subroutine for calculating a valve opening command value ICMD, and FIG. 3 is a subroutine for calculating an air conditioner load term FIG. 4 is a diagram showing a table of air conditioner load terms applied in the subroutine of FIG. 3, FIG. 5 is a diagram showing a table of a similar rotational speed correction coefficient K _NAC , and FIG. FIG. 6 is a diagram showing changes in a valve opening command value ICMD and the like in the subroutine of FIG. 1 ... internal combustion engine, 5 ... electronic control unit (ECU) (output increase correction means, increase value setting means), 11 ...
... Engine speed (Ne) sensor (speed detection means), 20
…… Compressor, 28… Piston, 31 …… Stroke (F _STR ) sensor (load torque detecting means), 32,33… P
D ₁ , PD ₂ switch (load torque detecting means).

Claims (1)

(57) [Claims] 1. A compressor driven by an internal combustion engine of a vehicle and having a variable capacity.
An output control device for an internal combustion engine, comprising: an output increase correction unit that maximum corrects an output torque of the internal combustion engine in accordance with an operation of the compressor; a load torque detection unit that detects a load torque of the compressor; And an increase value setting means for setting an output increase value of the output increase correction means in accordance with outputs of the load torque detection means and the rotation number detection means. An output control device for an internal combustion engine, wherein the output increase value is set to a larger value as the engine speed increases.