JPH1122494A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively compensate the driving torque of an auxiliary machine by calculating the driving torque of the auxiliary machine from the intake passage area of an intake air flow regulating means, and adding it to an engine torque to calculate the total engine output torque. SOLUTION: In the drive of an auxiliary machine F, an intake air flow regulating valve C is interlocked to the load of the accessory F to change the intake passage area, whereby the driving torque of the auxiliary machine is compensated. Namely, in a control device D, the intake passage area change quantity of the intake air flow regulating valve C is calculated, and the auxiliary machine driving torque is calculated form the calculated change quantity of the intake passage area. According to the operating state of an engine E, a target driving torque is calculated, and the target driving torque is added to the anxiliary machine driving torque to calculate a target total output torque. A target total intake passage area is calculated from the target total engine output torque and the operating state of the engine E, and the intake passage area is subtracted from the target total intake passage area to calculate a target throttle opening, and a throttle B is controlled according to it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an internal combustion engine capable of compensating a driving torque of an auxiliary device driven by the internal combustion engine irrespective of an air-fuel ratio and maintaining a stable idling rotational speed. .

[0002]

2. Description of the Related Art As a conventional control apparatus for an internal combustion engine, for example, an intake air amount adjusting means as disclosed in Japanese Patent Application Laid-Open No. 8-135473 is used, and suction is performed so as to balance the drive torque of a hydraulic pump for power steering. By compensating the drive torque of the power steering hydraulic pump by increasing the amount of air, the drive torque of the power steering pump changes due to the steering being turned off during idle operation, and the engine rotational speed is temporarily reduced. 2. Description of the Related Art A control device for an internal combustion engine that prevents the engine from falling down is known.

[0003]

For example, in an internal combustion engine that supplies fuel directly into a cylinder, for example, during idling operation,
Since the air-fuel ratio is largely changed according to the operating state of the internal combustion engine, the pressure downstream of the throttle increases as the intake air amount increases. Here, although the intake passage area and the passing air flow rate are almost proportional, the gain of the air flow rate with respect to the intake passage area is, as shown in FIG. 6, due to the relationship between the upstream pressure P ₁ and the downstream pressure P ₂ . Change. That is, in the super-lean region where the stoichiometric air-fuel ratio and the air-fuel ratio are 40, there is a problem that even in the same intake passage area, the super-lean region is smaller.

In the conventional internal combustion engine described above, the fuel injection amount is set so that the target air-fuel ratio is obtained from the intake air amount.
In the case of a super-lean region such as 0, there is a problem that the torque generated by the engine is smaller than in the case of the stoichiometric air-fuel ratio.

If the air-fuel ratio is changed to solve such a problem, the driving torque of the auxiliary machine may not be compensated.

The present invention has been made in view of the above situation, and an object of the present invention is to provide a drive torque of an auxiliary machine driven by an internal combustion engine with an air-fuel ratio (difference between an outside air pressure and a manifold pressure). It is an object of the present invention to provide a control device for an internal combustion engine that can stably maintain an idling rotational speed by compensating independently of pressure.

[0007]

In order to achieve the above-mentioned object, the invention described in claim 1 is to change the area of the intake passage in conjunction with the load of the accessory while the accessory is being driven. The technical premise of the present invention is a control device for an internal combustion engine which is configured to have an intake air amount adjusting means for compensating for the driving torque of the auxiliary equipment. Intake passage area change amount calculating means for calculating the amount, auxiliary machine drive torque calculating means for calculating an auxiliary machine drive torque from the change amount of the intake passage area, and calculating a target drive torque in accordance with an operation state of the internal combustion engine. Engine torque commanding means, target total engine output torque calculating means for calculating the target total engine output torque by adding the accessory drive torque and the target drive torque, and the target total engine output torque and the operation of the internal combustion engine. Target total intake passage area calculating means for calculating a target total intake passage area from the situation; target throttle opening degree calculating means for subtracting the intake passage area from the target total intake passage area to calculate a target throttle opening degree; And a throttle operating means for operating the throttle so that the opening is attained.

[0008] In the present invention, the auxiliary device may be configured as follows.
It is a hydraulic pump for power steering as described in the above, or a compressor for an air conditioner as described in the third aspect.

In the present invention, the target total intake passage area calculating means may include a target total intake passage area at least using the target total engine output torque and a target air-fuel ratio. Is calculated.

[0010]

According to the first aspect of the invention, the driving torque of the auxiliary machine driven by the internal combustion engine is always compensated regardless of the magnitude of the pressure difference between the upstream and downstream of the inflow air amount adjusting valve. be able to.

According to the second aspect of the present invention, the driving torque of the hydraulic pump for power steering driven by the internal combustion engine is controlled irrespective of the magnitude of the pressure difference between the upstream and downstream of the inflow air amount adjusting means. , Can always be compensated.

According to the third aspect of the present invention, the driving torque of the air conditioner compressor driven by the internal combustion engine is always compensated regardless of the magnitude of the pressure difference between the upstream and downstream of the inflow air amount adjusting means. can do.

In the invention described in claim 4, even when the total suction passage area is calculated based on the air-fuel ratio, compensation is always made irrespective of the magnitude of the pressure difference between the upstream and downstream of the inflow air amount adjusting means. Can be.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the accompanying drawings.

FIG. 1 shows an overall configuration of a control system for an internal combustion engine according to an embodiment of the present invention. In FIG. 1, reference symbol A denotes an engine torque command means for determining a target generated torque of the engine. And a means for determining the target intake passage area. Reference numeral B denotes a throttle, which adjusts the throttle so as to have a predetermined intake passage area. The code C is
This is an intake air amount adjusting means for changing an intake passage area in accordance with a force generated by the auxiliary device. Reference numeral D is a control device for an internal combustion engine according to the present embodiment. Symbol E is an engine,
A torque corresponding to the amount of air passing through the throttle and the intake air amount adjusting means is generated. Reference numeral F denotes an accessory, which is directly or indirectly connected to the output shaft of the engine and is driven by the engine.

Next, FIG. 2 shows a basic system configuration for implementing the present control system. In FIG. 2, reference numeral 1 denotes a hot wire type air flow sensor, which measures the amount of air supplied to an intake pipe. . Reference numeral 2 denotes a bypass passage for supplying air to the engine by bypassing the throttle valve. The supply air amount is adjusted by the auxiliary air valve 3. Reference numeral 4 denotes a throttle valve, which opens and closes in conjunction with an accelerator pedal (not shown). Reference numeral 5 indicates an intake manifold,
Reference numeral 6 denotes an intake pipe, reference numeral 7 denotes an exhaust pipe, reference numeral 8 denotes a cylinder block, reference numeral 9 denotes a cylinder head, reference numeral 10 denotes a combustion chamber, reference numeral 11 denotes a piston, and reference numeral 12 denotes a connecting rod. . Reference numerals 13 and 14 denote intake valves and exhaust valves, which open and close in synchronization with rotation of a crankshaft (not shown).

Reference numeral 15 denotes an injector, which injects an amount of fuel specified by an engine control unit (ECU) 20. Reference numeral 16 denotes an ignition plug, which ignites fuel in the combustion chamber at a timing commanded by the engine control unit 20. Symbol 17 is
An O ₂ sensor that detects the presence or absence of oxygen in the exhaust gas. Reference numeral 19 denotes a water temperature sensor, which detects the temperature of the engine cooling water. This engine control unit (E
The CU) 20 performs time measurement, arithmetic processing, storage, and instructions to the actuator. Reference numeral 21 denotes a throttle control module (TCM) which gives a command to a motor directly connected to the throttle so that the throttle has a predetermined opening. Reference numeral 22 denotes an intake flow rate adjusting valve,
The opening is changed according to the hydraulic pressure on the discharge side of the power steering pump.

Next, sensors and actuators required for the control system will be described.

The throttle opening sensor is of a potentiometer type and outputs a signal corresponding to the amount of depression of the accelerator pedal. The signal is sent to the engine control unit 2
Input to 0.

The electric throttle adjusts the opening based on an opening command from the engine control unit 20.

As shown in FIG. 3, for example, as shown in FIG. 3, the intake flow rate adjusting hand valve 22 is operated by pressing a piston by a hydraulic pressure generated by a hydraulic pump for power steering, and opening and closing a valve directly connected to the piston. The area of the intake passage is changed to adjust the flow rate of the passing air. An encoder is directly connected to the valve, and the displacement of the piston is measured.

The ignition plug 16 ignites fuel at a command ignition timing from the engine control unit 20.

The injector 15 supplies a command amount of fuel from the engine control unit 20 to the engine.

In the engine control unit 20,
The engine speed measurement, target speed calculation, idle determination, ignition timing calculation, and the like are performed every 10 msec or every combustion.

FIG. 4 shows a basic configuration of the engine control unit 20, and FIG. 5 shows a control flowchart thereof.

Hereinafter, the processing in each step of FIG. 5 will be described.

In step S101, a signal which is directly connected to the valve of the intake air amount adjusting means and detects the displacement of the valve by the potentiometer is read, and the opening degree of the valve is obtained.

In step S102, the intake passage area is determined from the valve opening by referring to a map of valve characteristics.
In the present embodiment, the map is referred to, but may be obtained by calculation.

In step S103, the intake flow rate during sonic operation is calculated from the intake passage area, the torque generated by the engine is calculated from the calculated inflow air amount, and the calculated torque is used as the accessory drive torque. In the present embodiment, the inflow air amount is calculated once, but it may be calculated directly or by referring to a map.

In step S104, the required engine torque is calculated according to the operating condition of the engine.

In step S105, step S103
The target total engine output torque is calculated by adding the accessory drive torque obtained in step (1) and the engine torque obtained in step S104.

In step S106, the amount of intake air (Q) is calculated based on the air-fuel ratio set for the engine to generate the target total engine output torque, and the atmospheric pressure (Patm) and Manifold pressure (Pma
n), the target total intake passage area (A) is calculated with reference to the map. Although the map is referred to in the present embodiment, it can be obtained by the following equation (1).

[0033]

(Equation 1)

In step S107, step S106
The intake passage area of the throttle is calculated by subtracting the intake passage area of the intake air amount adjusting means determined in step S102 from the target total intake passage area determined in step S102.

By controlling the engine control unit 20, the excess or deficiency of the driving torque of the auxiliary equipment can be compensated by the throttle opening, so that the difference in pressure between the upstream and downstream of the intake air flow control valve 22 can be obtained. In addition, the driving torque of the auxiliary machine F can be compensated.

[0036]

As described above, in the control apparatus for an internal combustion engine according to the first aspect of the present invention, the drive torque of the auxiliary machine is calculated from the intake passage area of the intake air flow rate adjusting means. Since the total engine output torque is calculated by adding to the engine torque, the pressure difference between the upstream and downstream of the intake air flow control valve changes, the flow characteristics change, and the drive torque of the auxiliary equipment can be compensated correctly. Even if it is not, the excess or deficiency can be compensated by the throttle opening, so that the drive torque of the auxiliary machine can be compensated regardless of the pressure difference between the upstream and downstream of the intake air flow control valve.

In determining the intake passage area of the electronically controlled throttle, the intake passage area of the intake air flow control valve is taken into account. Can be adjusted.

According to the second aspect of the present invention, the drive torque of the hydraulic pump for power steering can be compensated even if the pressure difference between the upstream and downstream of the intake air flow control valve changes. .

Further, according to the third aspect of the invention, the driving torque of the compressor for the air conditioner can be compensated even if the pressure difference between the upstream and downstream of the intake air flow control valve changes.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of a control system for an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a specific configuration of the control device.

FIG. 3 is an explanatory diagram showing a configuration example of an intake air amount adjusting means in the control device.

FIG. 4 is a block diagram showing a basic configuration of the control device.

FIG. 5 is a flowchart of control in an engine control unit of the control device.

FIG. 6 is a graph showing characteristics of intake air flow depending on pressures upstream and downstream of an intake air flow control valve.

[Explanation of symbols]

 A engine torque command means B throttle C intake air amount adjustment means D control device for internal combustion engine E engine F auxiliary equipment 20 engine control unit (ECU) 22 intake flow rate adjustment valve

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 41/08 310 F02D 41/08 310 41/14 320 41/14 320C 41/16 41/16 E

Claims (4)

[Claims] An intake air amount adjusting means for compensating for a driving torque of an auxiliary machine by changing an intake passage area in conjunction with a load of the auxiliary machine during driving of the auxiliary machine. A control device for an internal combustion engine, comprising: an intake passage area change amount calculating unit that calculates an intake passage area change amount of the intake air amount adjusting unit; and an auxiliary device that calculates an auxiliary device driving torque from the intake passage area change amount. Drive torque calculation means, engine torque command means for calculating a target drive torque according to the operation state of the internal combustion engine, and a target for calculating the target total engine output torque by adding the accessory drive torque and the target drive torque Total engine output torque calculating means; target total intake passage area calculating means for calculating a target total intake passage area from the target total engine output torque and the operating state of the internal combustion engine; Target throttle opening calculating means for calculating the target throttle opening by subtracting the intake passage area;
A control device for an internal combustion engine, comprising: throttle operation means for operating a throttle so as to attain the target throttle opening. 2. The control device for an internal combustion engine according to claim 1, wherein the auxiliary device is a hydraulic pump for power steering. 3. The control device for an internal combustion engine according to claim 1, wherein the auxiliary device is a compressor for an air conditioner. 4. The target total intake passage area calculating means calculates a target total intake passage area using at least the target total engine output torque and a target air-fuel ratio. The control device for an internal combustion engine according to any one of the above.