JP2009281144A - Control device for internal combustion engine with turbocharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent generation of abnormal noise by avoiding a compressor from entering a surge area when an engine shifts from a heavy load condition to a light load condition in the engine having a throttle valve disposed in an intake passage at a downstream side of a turbocharger. <P>SOLUTION: Surge limit throttle opening (minimum throttle opening) for preventing the compressor from entering the surge area when the engine is shifted from a condition where the compressor of a turbocharger is rotating at high speed under a heavy load and high charging to a light load condition by returning an accelerator is calculated based on intake air quantity. The throttle valve is controlled with a limit (lower limit guard for target throttle opening) provided at a side closing the throttle valve based on the surge limit throttle opening. By such control, entrance of the surge area can be avoided and generation of abnormal noise can be prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine with a supercharger (for example, a diesel engine).

  For example, a turbocharger (supercharger) and an EGR device (exhaust gas recirculation device) are provided in a diesel engine mounted on a vehicle or the like.

  A turbocharger mounted on an engine generally includes a turbine (turbine wheel) that is rotated by exhaust gas flowing through an exhaust passage of the engine, a compressor (compressor impeller) that forcibly sends air in the intake passage to a combustion chamber, A turbine shaft connecting the turbine and the compressor is provided. In the turbocharger having such a structure, when exhaust gas is blown onto the turbine and the turbine rotates, the rotation is transmitted to the compressor via the turbine shaft. As the compressor rotates in this way, the air in the intake passage is forcibly sent into the combustion chamber.

  The EGR device recirculates a part of the exhaust gas discharged to the exhaust passage of the engine as a recirculation gas to the intake passage via the EGR passage (exhaust gas recirculation passage), and mixes it with the air-fuel mixture to lower the combustion temperature. This suppresses the generation of NOx. In such an EGR device, an EGR valve is provided in the EGR gas passage, and an exhaust gas recirculation amount (EGR gas amount) recirculated to the intake passage is controlled by the EGR valve.

  In addition, in a diesel engine equipped with a turbocharger, there is known one in which a throttle valve is arranged in an intake passage on the downstream side of the turbocharger (see, for example, Patent Documents 1 to 3).

  Thus, in a diesel engine equipped with a throttle valve, mainly in a light load range (1) a large amount of EGR is put in (reducing the pressure downstream of the EGR valve), (2) the exhaust temperature is raised (intake for catalyst activity) The throttle valve is closed for the purpose of reducing the air volume and raising the exhaust temperature. On the other hand, in the high load range, the throttle valve is opened and the intake pressure is increased with a turbocharger to increase the air volume and increase the output.

In Patent Document 1, in an engine including a supercharger driven by engine exhaust energy and an intake throttle valve disposed in an intake passage on the downstream side of the compressor of the supercharger, the rotational speed of the compressor is There is described a technique for preventing the occurrence of surging by providing an “annealing time” so that the intake throttle valve does not close until the pressure decreases, thereby preventing an increase in the pressure ratio before and after the compressor.
JP 2008-008241 A JP 2001-280144 A Japanese Patent Laid-Open No. 06-058173

  By the way, in the diesel engine described above, when the throttle valve is suddenly closed when the accelerator is returned to a light load from a state where the compressor is rotating at high speed with high load and high supercharging, the compressor rotates with inertia. As a result, the pressure on the downstream side of the compressor increases. In such a situation, for example, as shown in FIG. 7, the compressor enters a surge region determined by the relationship between the pressure ratio before and after the compressor (P2 / P1) and the air flow rate passing through the compressor, and abnormal noise is generated from the compressor. There is.

  The present invention has been made in view of such circumstances, and a turbocharger having a turbine disposed in an exhaust passage and a compressor disposed in an intake passage, and a downstream side of the supercharger. In a control device for an internal combustion engine with a supercharger provided with a throttle valve arranged in an intake passage, for example, when the accelerator is returned from a high load / high supercharge state to shift to a light load, the compressor enters a surge region. Therefore, an object of the present invention is to realize throttle control capable of avoiding this and preventing the generation of abnormal noise.

  To achieve the above object, the present invention provides a turbocharger having a turbine disposed in an exhaust passage of an internal combustion engine (engine) and a compressor disposed in an intake passage of the internal combustion engine, and a downstream side of the supercharger. And a control device for an internal combustion engine with a supercharger provided with a throttle valve disposed in the intake passage of the engine. In such a control device for an internal combustion engine, the throttle valve is prevented from entering the surge region of the compressor. It is characterized by comprising throttle control means for controlling the throttle opening.

  In the present invention, as a specific configuration of the throttle control means, the surge limit throttle opening is calculated based on the intake air amount of the internal combustion engine (for example, the intake air amount detected by an air flow meter or the like) and the throttle valve is opened. A configuration in which the degree is controlled can be mentioned. More specifically, for example, as shown in FIG. 3, the surge limit pressure ratio (P2 / P1) and the compressor upstream pressure P1 are calculated based on the intake air amount (air flow rate), and the surge limit pressure ratio is calculated. The surge limit pressure P2 is calculated from (P2 / P1) and the pressure P1. And the pressure difference ([P2-Pin]: throttle valve front-rear pressure difference) between the surge limit pressure P2 (pressure upstream of the slot valve) and the pressure downstream of the throttle valve (intake manifold pressure) Pin, and the intake air amount A configuration in which a surge limit throttle opening (minimum throttle opening) is calculated with reference to a map using the control to control the throttle opening of the throttle valve can be mentioned.

  Further, as a specific configuration when performing such throttle control, a guard (limit) is provided on the closing side of the target throttle opening based on the surge limit throttle opening to control the throttle opening of the throttle valve. The configuration of performing

  Next, the operation of the present invention will be described.

  In the present invention, for example, the relationship between the pressure ratio before and after the compressor and the air flow rate passing through the compressor when the accelerator is returned to the light load from the state where the compressor is rotating at high speed with high load and high supercharging. The throttle opening is controlled so that it does not enter the surge region determined by (see FIG. 7). Specifically, a guard (limit) is provided on the closing side of the target throttle opening based on the surge limit throttle opening calculated according to the intake air amount, etc., so that the throttle valve throttle opening is prevented from entering the surge region. Control the degree. By such control, it is possible to avoid entering the surge region of the compressor and to prevent the generation of abnormal noise.

  In the prior art such as the technique described in Patent Document 1, for example, a delay time (experimentally adapted value) such as “annealing time” is provided, and the intake air throttle is reduced until the rotational speed of the compressor of the supercharger decreases. Since the valve is not closed, surging may not be reliably prevented if the delay time cannot be adjusted accurately. In contrast, in the present invention, the surge limit throttle opening (minimum throttle opening) is calculated based on the intake air amount (air flow rate through the compressor) and the like, and based on this, a guard is provided on the throttle valve closing side. Since it is provided to avoid entering the surge region, it is possible to more reliably prevent the generation of abnormal noise from the compressor.

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

  First, a diesel engine to which the present invention is applied will be described.

-Engine-
A schematic configuration of a diesel engine to which the present invention is applied will be described with reference to FIG. FIG. 1 shows only the configuration of one cylinder of the engine.

  A diesel engine 1 (hereinafter referred to as engine 1) shown in FIG. 1 is, for example, an in-cylinder direct injection four-cylinder diesel engine, and a piston 1c that reciprocates in a vertical direction is disposed in a cylinder block 1a constituting each cylinder. Is provided. The piston 1c is connected to the crankshaft 15 via the connecting rod 16, and the reciprocating motion of the piston 1c is converted into rotation of the crankshaft 15 by the connecting rod 16.

  A signal rotor 17 is attached to the crankshaft 15. A plurality of protrusions (teeth) 17a... 17a are provided on the outer peripheral surface of the signal rotor 17 at equal angles. An engine speed sensor (crank position sensor) 25 is disposed near the side of the signal rotor 17. The engine speed sensor 25 is, for example, an electromagnetic pickup, and generates a pulsed signal (output pulse) corresponding to the protrusion 17a of the signal rotor 17 when the crankshaft 15 rotates.

  The cylinder block 1a of the engine 1 is provided with a water temperature sensor 21 that detects the engine cooling water temperature. A cylinder head 1b is provided at the upper end of the cylinder block 1a, and a combustion chamber 1d is formed between the cylinder head 1b and the piston 1c.

  An oil pan 18 for storing lubricating oil is provided below the cylinder block 1a of the engine 1. The lubricating oil stored in the oil pan 18 is pumped up by an oil pump through an oil strainer that removes foreign matters during operation of the engine 1 and further purified by an oil filter, and then the piston 1c, the crankshaft 15, and the connecting oil. It is supplied to the rod 16 and used for lubrication and cooling of each part. The lubricating oil supplied in this way is used for lubrication and cooling of each part of the engine 1 and then returned to the oil pan 18 and stored in the oil pan 18 until it is pumped up again by the oil pump. Is done.

  The cylinder head 1 b of the engine 1 is provided with an injector (fuel injection valve) 2 for directly injecting fuel into the combustion chamber 1 d of the engine 1. A common rail (accumulation chamber) 3 is connected to the injector 2, and fuel in the common rail 3 is injected from the injector 2 into the combustion chamber 1 d while the solenoid valve of the injector 2 is open. The common rail 3 is provided with a rail pressure sensor 24 for detecting the pressure (rail pressure) of the high-pressure fuel in the common rail 3. A supply pump 4 that is a fuel pump is connected to the common rail 3.

  The supply pump 4 is driven by the rotational force of the crankshaft 15 of the engine 1. By driving the supply pump 4, fuel is supplied from the fuel tank 10 to the common rail 3 and the injector 2 is opened at a predetermined timing. The fuel is injected into the combustion chamber 1d of each cylinder of the engine 1. The injected fuel is combusted in the combustion chamber 1d and exhausted as exhaust gas. The valve opening timing (injection period) of the injector 2 is controlled by an ECU (Electronic Control Unit) 100 described later.

  On the other hand, an intake passage 11 and an exhaust passage 12 are connected to the combustion chamber 1 d of the engine 1. An intake valve 13 is provided between the intake passage 11 and the combustion chamber 1d. By opening and closing the intake valve 13, the intake passage 11 and the combustion chamber 1d are communicated or blocked. Further, an exhaust valve 14 is provided between the exhaust passage 12 and the combustion chamber 1d. By opening and closing the exhaust valve 14, the exhaust passage 12 and the combustion chamber 1d are communicated or blocked. The opening / closing drive of the intake valve 13 and the exhaust valve 14 is performed by each rotation of the intake camshaft and the exhaust camshaft to which the rotation of the crankshaft 15 is transmitted.

  In the intake passage 11, an air cleaner 8, an air flow meter 22 that detects an intake air amount (air flow rate), an intake air temperature sensor 23 (built in the air flow meter 22), a throttle valve 7, and the like are arranged. The throttle valve 7 is disposed in the intake passage 11 on the downstream side of the compressor 52 of the turbocharger 5 described later. An intake manifold pressure sensor 28 for detecting the pressure (intake manifold pressure) in the intake manifold 11 a is disposed in the intake passage 11 downstream of the throttle valve 7.

  A catalyst device 9 and the like are disposed in the exhaust passage 12. The catalyst device 9 includes a NOx storage reduction catalyst 91 and a DPNR catalyst 92.

The NOx occlusion reduction type catalyst 91 occludes NOx in a state where a large amount of oxygen is present in the exhaust gas, has a low oxygen concentration in the exhaust gas, and has a reducing component (for example, an unburned component (HC) of the fuel). In a state where a large amount exists, NOx is reduced to NO ₂ or NO and released. NO NOx released as NO ₂ or NO, the N ₂ is further reduced due to quickly reacting with HC or CO in the exhaust. Further, HC and CO are oxidized to H ₂ O and CO ₂ by reducing NO ₂ and NO.

  The DPNR catalyst 92 is, for example, a NOx occlusion reduction catalyst supported on a porous ceramic structure, and PM (particulate matter) in the exhaust gas is collected when passing through the porous wall. Further, when the air-fuel ratio of the exhaust gas is lean, NOx in the exhaust gas is occluded by the NOx occlusion reduction type catalyst, and when the air-fuel ratio becomes rich, the occluded NOx is reduced and released. Further, the DPNR catalyst 92 carries a catalyst that oxidizes and burns the collected PM (for example, an oxidation catalyst mainly composed of a noble metal such as platinum).

  The engine 1 is equipped with a turbocharger (supercharger) 5 that supercharges intake air using exhaust pressure. The turbocharger 5 is configured by a turbine 51 disposed in the exhaust passage 12 and a compressor 52 disposed in the intake passage 11, and the turbine 51 disposed in the exhaust passage 12 is rotated by the energy of the exhaust. Thus, the compressor 52 arranged in the intake passage 11 rotates. Then, the intake air is supercharged by the rotation of the compressor 52, and the supercharged air is forcibly sent into the combustion chamber 1 d of each cylinder of the engine 1.

  The turbocharger 5 is a variable nozzle type turbocharger, and a variable nozzle vane mechanism 53 is provided on the turbine 51 side. By adjusting the opening of the variable nozzle vane mechanism 53, the supercharging pressure of the engine 1 is adjusted. be able to. The opening degree of the variable nozzle vane mechanism 53 is adjusted by an actuator 54 such as a DC motor controlled by the ECU 100. In the intake passage 11 on the downstream side of the compressor 52 of the turbocharger 5, an intercooler 55 for cooling the intake air that has been compressed by the compressor 52 and has reached a high temperature is provided.

  Further, an EGR device 6 is mounted on the engine 1. The EGR device 6 is a device that reduces the combustion temperature in the cylinders by reducing part of the exhaust gas into the intake air, thereby reducing the amount of NOx generated. The EGR device 6 communicates the intake passage 11 and the exhaust passage 12 with each other. The EGR passage 61, an EGR valve 62 provided in the EGR passage 61, an EGR cooler (not shown), and the like are configured. By adjusting the opening degree of the EGR valve 62, the intake air is introduced from the exhaust passage 12. The EGR amount (exhaust gas recirculation amount) introduced into the passage 11 can be adjusted.

  Each part such as the engine 1, the actuator 54 of the turbocharger 5, the throttle valve 7, and the EGR valve 62 is controlled by the ECU 100.

-ECU-
As shown in FIG. 2, the ECU 100 includes a CPU 101, a ROM 102, a RAM 103, a backup RAM 104, and the like.

  The ROM 102 stores various control programs, maps that are referred to when the various control programs are executed, and the like. The CPU 101 executes various arithmetic processes based on various control programs and maps stored in the ROM 102. The RAM 103 is a memory that temporarily stores calculation results of the CPU 101, data input from each sensor, and the like. The backup RAM 104 is a nonvolatile memory that stores data to be saved when the engine 1 is stopped, for example. Memory.

  The CPU 101, the ROM 102, the RAM 103, and the backup RAM 104 are connected to each other via the bus 107, and are connected to the input interface 105 and the output interface 106.

  The input interface 105 includes a water temperature sensor 21, an air flow meter 22, an intake air temperature sensor 23, a rail pressure sensor 24, an engine speed sensor 25, a throttle opening sensor 26 that detects the opening of the throttle valve 7, an accelerator pedal depression amount ( An accelerator opening sensor 27 for detecting the accelerator opening) and an intake manifold pressure sensor 28 for detecting the intake manifold pressure on the downstream side of the throttle valve 7 are connected.

  The output interface 106 is connected to the injector 2, the throttle valve 7, the actuator 54 that adjusts the opening degree of the variable nozzle vane mechanism 53 of the turbocharger 5, the EGR valve 62, and the like.

  Then, the ECU 100 executes various controls of the engine 1 including fuel injection control (opening / closing control of the injector 2) and the following throttle control based on the outputs of the various sensors described above.

-Throttle control-
First, in the engine 1 of this example, the throttle opening degree of the throttle valve 7 is controlled by the ECU 100. Specifically, according to the operating state of the engine 1 based on the accelerator opening (injection amount) detected by the accelerator opening sensor 27, the engine speed detected by the engine speed sensor 25, and the like. The throttle opening of the throttle valve 7 is controlled so that the intake air amount (target intake air amount) is obtained. More specifically, the actual throttle opening of the throttle valve 7 is detected using the throttle opening sensor 26, and the actual throttle opening coincides with the throttle opening (target throttle opening) at which the target intake air amount can be obtained. Thus, the throttle motor (not shown) of the throttle valve 7 is feedback-controlled.

  Further, the throttle control executed in this example will be specifically described. For example, mainly in the light load range, (1) a large amount of EGR is added to lower the pressure on the downstream side of the EGR valve 62. (2) Control is performed to close the throttle valve 7 for the purpose of increasing the exhaust temperature by reducing the intake air amount for the catalytic activity of the catalyst device 9. On the other hand, in a high load range, the throttle valve 7 is opened and the intake air pressure is increased by the turbocharger 5 to increase the air amount and increase the output.

  By the way, in the engine 1 shown in FIG. 1, that is, the engine 1 in which the throttle valve 7 is disposed in the intake passage 11 on the downstream side of the turbocharger 5 (compressor 52), as described above, the load is high and the turbocharging is high. When the throttle valve 7 is suddenly closed when the accelerator 52 is returned to a light load from a state where the compressor 52 is rotating at a high speed, a surge region (see FIG. 7) is entered, and an abnormal noise is generated from the compressor 52. May occur.

  In order to eliminate such a point, in this example, the surge limit throttle opening that enters the surge region (region where abnormal noise is generated) is calculated based on the intake air amount, and the closed side of the throttle valve 7 is calculated based on this. This is characterized by controlling the throttle valve 7 with a limitation to avoiding the occurrence of abnormal noise by avoiding entering the surge region.

  The specific processing will be described with reference to the block diagram of FIG. Each process shown in FIG. 3 is executed in ECU 100.

  (S1) The accelerator opening is read from the output signal of the accelerator opening sensor 27, the engine speed is read from the output signal of the engine speed sensor 25, and the target throttle is determined from the accelerator opening (injection amount) and the engine speed. Calculate the opening. The target throttle opening calculated in this process S1 is hereinafter also referred to as “target throttle opening based on operating conditions”.

  (S2) The intake air amount (air flow rate) is read from the output signal of the air flow meter 22, and the surge limit pressure ratio (P2 / P1) is calculated using the intake air amount with reference to the map shown in FIG. The map for calculating the surge limit pressure ratio (P2 / P1) used in this process S2 is the flow rate of air passing through the compressor 52 of the turbocharger 5 and the pressure ratio before and after the compressor 52 (upstream of the compressor 52 shown in FIG. This is a map obtained by mapping the surge limit line (see FIG. 7) based on the characteristics (compressor characteristics) of the turbocharger 5 using the ratio of the pressure P1 on the side and the pressure P2 on the downstream side as a parameter. And stored in the ROM 102 of the ECU 100.

  (S3) Using the intake air amount (air flow rate) read from the output signal of the air flow meter 22, the pressure P1 on the upstream side of the compressor 52 is estimated with reference to the map of FIG.

  The map shown in FIG. 5 is a map that takes into account the pressure loss of the air cleaner 8, and is stored in the ROM 102 of the ECU 100. In the map of FIG. 5, the larger the air flow rate (intake air amount), the smaller the pressure P1 on the upstream side of the compressor 52 becomes (a value lower than the atmospheric pressure). .

  (S4) Using the surge limit pressure ratio (P2 / P1) calculated in the process S2 and the estimated value of the pressure P1 calculated in the process S3, the pressure P1 is used as the surge limit pressure ratio (P2 / P1). Is multiplied by the estimated value to determine the surge limit pressure P2.

  (S5) The pressure difference obtained by reading the intake manifold pressure from the output signal of the intake manifold pressure sensor 28 and subtracting the intake manifold pressure Pin from the surge limit pressure P2 obtained in the above-described process S4 (pressure difference before and after the throttle valve 7: [Ps−Pin] ) And the surge limit throttle opening is calculated by referring to the map shown in FIG. 6 using the pressure difference (Ps−Pin) and the intake air amount (air flow rate) read from the output signal of the air flow meter 22. To do.

  The map shown in FIG. 6 uses the flow rate of air passing through the throttle valve 7 and the pressure difference between the front and rear of the throttle valve 7 as parameters, and the upstream side (front side) pressure P2 of the throttle valve 7 is the downstream side (rear side) pressure. When the pressure is larger than Pin (intake manifold pressure) (P2> Pin), the throttle valve 7 can be closed by an amount corresponding to the pressure difference before and after that, that is, the pressure difference between the front and rear of the throttle valve 7 (P2−Pin). In consideration of the above, a value obtained by empirically obtaining the surge limit throttle opening in advance through experiments, calculations, and the like is mapped and stored in the ROM 102 of the ECU 100. In the map of FIG. 6, the surge limit throttle opening is set according to the air flow rate so that the surge limit throttle opening is on the open side (opening is larger) as the air flow rate is larger.

  (S6) Of the target throttle opening based on the operating condition calculated in the above-described process S1 and the surge limit throttle opening calculated in the above-described process S5, the larger throttle opening is selected and selected The throttle valve 7 is controlled with the throttle opening thus set as the target throttle opening. Specifically, for example, when the operating region of the engine 1 is a light load region, the target throttle opening based on the operating condition calculated from the accelerator opening and the engine speed is small, and the intake air amount and the throttle valve When the surge limit throttle opening calculated from the pressure difference (P2−Pin) of FIG. 7 is larger than the target throttle opening based on the above operating conditions, the closing side of the target throttle opening is determined by the surge limit throttle opening. The throttle valve 7 is controlled so that the actual throttle opening is not smaller than the surge limit throttle opening.

  In the throttle control of this example, for example, when the compressor 52 of the turbocharger 5 is rotating at high speed with high load and high supercharging, when the accelerator is returned to shift to a light load, before and after the compressor 52 A guard is provided on the closing side of the target throttle opening to control the throttle opening of the throttle valve 7 so as not to enter a surge region (see FIG. 7) determined by the relationship between the pressure ratio and the air flow rate passing through the compressor 52. Therefore, entering the surge region of the compressor 52 can be avoided, and abnormal noise can be prevented.

  In addition, the intake air amount and intake manifold pressure are detected (actually measured), and the surge limit throttle opening is calculated based on these measured values to regulate the closing side of the throttle opening, reflecting the current operating state. Thus, appropriate throttle control can be executed, and this can more reliably prevent the generation of abnormal noise in the surge region.

-Other embodiments-
In the above example, the example in which the present invention is applied to the throttle control of the in-cylinder direct injection four-cylinder diesel engine has been described. However, the present invention is not limited thereto, It can also be applied to throttle control of a diesel engine with an arbitrary number of cylinders. Further, the present invention is not limited to an in-cylinder direct injection diesel engine, but can be applied to throttle control of other types of diesel engines.

  Further, the present invention is not limited to a diesel engine, and the present invention can be applied to throttle control of a port injection gasoline engine or an in-cylinder direct injection gasoline engine.

  In the above example, the present invention is applied to throttle control of an engine equipped with a variable nozzle turbocharger. However, the present invention is not limited to this, and a turbocharger not equipped with a variable nozzle mechanism is installed. It can also be applied to throttle control of the engine.

It is a schematic structure figure showing an example of a diesel engine to which the present invention is applied. It is a block diagram which shows the structure of control systems, such as ECU. It is a control block diagram which shows the content of the throttle control which ECU performs. It is a figure which shows the map for the front-back pressure ratio (P2 / P1) calculation of a compressor. It is a figure which shows the map for the pressure P1 estimation of the upstream of a compressor. It is a figure which shows the map for surge limit throttle opening calculation. It is a figure which shows the surge area | region of a compressor.

Explanation of symbols

1 engine (diesel engine)
DESCRIPTION OF SYMBOLS 11 Intake passage 11a Intake manifold 12 Exhaust passage 5 Turbocharger 51 Turbine 52 Compressor 6 EGR apparatus 62 EGR valve 7 Throttle valve 22 Air flow meter 25 Engine speed sensor 26 Throttle opening sensor 27 Accelerator opening sensor 28 In manifold pressure sensor 100 ECU

Claims (3)

A turbocharger having a turbine disposed in an exhaust passage of an internal combustion engine and a compressor disposed in an intake passage of the internal combustion engine, and a throttle valve disposed in an intake passage downstream of the supercharger. In a control device for an internal combustion engine with a feeder,
A control apparatus for an internal combustion engine with a supercharger, comprising throttle control means for controlling a throttle opening of the throttle valve so as not to enter a surge region of the compressor. The control device for an internal combustion engine with a supercharger according to claim 1,
The control device for an internal combustion engine with a supercharger, wherein the throttle control means calculates a surge limit throttle opening based on an intake air amount of the internal combustion engine and controls a throttle opening of the throttle valve. The control apparatus for an internal combustion engine with a supercharger according to claim 2,
The control of the internal combustion engine with a supercharger, wherein the throttle control means controls the throttle opening of the throttle valve by providing a guard on the closing side of the target throttle opening based on the surge limit throttle opening apparatus.

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