JPH08135456A - Supercharging pressure control device for internal combustion engine - Google Patents

Abstract

PURPOSE: To avoid rapid reduction of supercharging pressure on the way of acceleration operation of a vehicle, and change supercharging pressure into a constant fully open supercharging pressure by controlling supercharging pressure in such a way that high side fully open supercharging pressure is gradually reduced When restrict control of supercharging pressure by high side fully open supercharging pressure is passed a prescribed time so as to change supercharging pressure into low side constant fully open supercharging pressure. CONSTITUTION: When an internal combustion engine 2 is started, it is judged by output of a throttle sensor 134 whether condition of acceleration is constant acceleration or rapid acceleration. At the time of constant acceleration, supercharging pressure by a supercharger 52 is restricted to constant supercharging pressure. On the other hand, at the time of rapid acceleration, a constant duty value is retrieved by characteristics of constant accelerating pressure which is found out by engine rotating speed, and also a correction duty value for rapid acceleration is retrieved, and then both values are summed up so as to obtain the summation duty value of the high side fully open supercharging pressure higher than constant supercharging pressure. When restrict control of supercharging pressure by the high side fully open supercharging pressure is passed a prescribed time, the high side fully open supercharging pressure is subtracted per a set value and per a set time from the high side fully open supercharging pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supercharging pressure control system for an internal combustion engine, and more particularly, it can prevent a rapid decrease in supercharging pressure during acceleration operation of a vehicle and prevent torque shock. And a supercharging pressure control device for an internal combustion engine capable of improving drivability.

[0002]

2. Description of the Related Art Some internal combustion engines mounted on vehicles or the like are equipped with a supercharger in order to improve fuel consumption rate and output. The supercharger can improve the combustibility by supercharging the intake air to the internal combustion engine, and can improve the fuel consumption rate and the output.

An internal combustion engine equipped with a supercharger is provided with a supercharging pressure control device for controlling the supercharging pressure to a fully-open supercharging pressure so that the supercharging pressure does not unnecessarily rise when the throttle valve is fully opened. There is one provided. An example of such a boost pressure control device is disclosed in Japanese Patent Laid-Open No. 3-182630.

The supercharging pressure control device disclosed in this publication is
The opening of the waste gate valve of the supercharger is feedback-controlled by the duty ratio control type actuator to converge the supercharging pressure to the target supercharging pressure.In the area where the throttle opening is less than the predetermined opening, the waste gate is opened. A feedback control is performed by setting a limit value for the duty ratio so that the valve opening does not fall below a predetermined value, and from this control state, the throttle opening exceeds the predetermined opening and the boost pressure does not converge to the target boost pressure. Feedback control is performed while maintaining the limit value of the duty ratio when shifting to, and when the boost pressure does not converge to the target value even after a predetermined time elapses, the waste gate valve opening tends to decrease. By changing the limit value of the ratio and performing feedback control, it is possible to prevent the overshoot reduction of the boost pressure during sudden acceleration. It is intended.

[0005]

By the way, in the conventional supercharging pressure control device, as shown in FIG. 10, at the time of steady full-open acceleration in which the throttle valve is fully opened at a speed less than a predetermined value, supercharging by the supercharger is performed. By controlling the pressure to be a steady full open supercharging pressure (broken line), the supercharging pressure is controlled so as not to exceed the steady full opening supercharging pressure which is the regulation value.

Further, in the conventional supercharging pressure control device,
At the time of sudden full-open acceleration when the throttle valve is fully opened at a speed equal to or higher than a predetermined value, the steady-state full-open supercharging pressure that regulates the supercharging pressure by the supercharger is set to the high-side full-opening higher than the steady-state full-open supercharging pressure. By controlling the supply pressure (solid line) to increase for a predetermined time, the regulation value of the supercharging pressure at the time of sudden full-open acceleration of the throttle valve becomes the high-side full-open supercharging pressure higher than the steady full-open supercharging pressure for the predetermined time. By increasing it, the supercharging pressure is allowed to rise above the steady full opening supercharging pressure to improve the acceleration performance of the vehicle.

However, in the conventional supercharging pressure control device, when the regulation control of the supercharging pressure by the high side fully opening supercharging pressure has passed a predetermined time, the high side fully opening supercharging pressure is immediately reduced to a steady full opening pressure. It is controlled to change to supply pressure.

Therefore, the conventional supercharging pressure control device immediately changes to the steady full opening supercharging pressure at the end of the regulation control by the high side full opening supercharging pressure. Therefore, as shown by the solid line in FIG. In the middle of, the supercharging pressure is suddenly reduced from the high side full opening supercharging pressure to the low side steady full opening supercharging pressure, and as shown in FIG. 11, there is an inconvenience that torque shock is generated and driveability deteriorates.

[0009]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention provides an internal combustion engine with a supercharger for supercharging intake air, and detects the opening state of a throttle valve of the internal combustion engine. A throttle sensor is provided to control the supercharging pressure by the supercharger to a steady full-open supercharging pressure at the time of steady full-open acceleration in which the throttle valve is fully opened at a speed less than a predetermined value. At the time of sudden full-open acceleration that is fully opened at the above speed, the steady-state full-open supercharging pressure that regulates the supercharging pressure by the supercharger is set to the high-side full-open supercharging pressure higher than the steady full-open supercharging pressure for a predetermined time. When the regulation control of the supercharging pressure by the high-side full-open supercharging pressure increased to the high side has passed a predetermined time, the high-side full-open supercharging pressure is gradually reduced and the steady full-open supercharging is performed. Control to change to pressure Characterized in that a means.

[0010]

According to the structure of the present invention, the supercharging pressure control device is
During rapid full-open acceleration when the throttle valve is fully opened by the control means at a speed equal to or higher than a predetermined value, the steady full-open supercharging pressure that regulates the supercharging pressure is set to the high-side full-open supercharging pressure higher than the steady full-open supercharging pressure. When the regulation control of the supercharging pressure by the high-side full-open supercharging pressure exceeds the predetermined time, the high-side full-open supercharging pressure is gradually reduced to a steady full-open supercharging pressure. By controlling as much as possible, the supercharging pressure does not suddenly drop during the acceleration operation of the vehicle.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 9 show an embodiment of the present invention. In FIG. 9, 2 is an internal combustion engine, 4 is a cylinder block, 6 is a cylinder head, 8 is a cylinder head cover, 10 is a piston, 12 is a combustion chamber, 14 is an intake valve, 1
6 is an exhaust valve.

In the internal combustion engine 2 mounted on the vehicle (not shown), an air cleaner 18, an intake pipe 20, a throttle body 22, a surge tank 24 and an intake manifold 26 are sequentially connected and provided, and a pipe intake passage 28 and a body are provided. The intake passage 30, the tank intake passage 32, and the manifold intake passage 34 are sequentially connected to the combustion chamber 12. A throttle valve 36 is provided in the body intake passage 30 of the throttle body 22.
Is provided.

Further, the internal combustion engine 2 is provided with an exhaust manifold 38 and an exhaust pipe 40 which are sequentially connected to each other, and the combustion chamber 1
2, the manifold exhaust passage 42 and the pipe exhaust passage 44 are sequentially connected. First and second catalysts 46 and 48 are provided in the exhaust gas passage 44 of the exhaust pipe 40. Reference numeral 50 is a blow-by gas passage that connects the inside of the cylinder head cover 8 and the pipe intake passage 28 on the downstream side of the air cleaner 18.

The internal combustion engine 2 is provided with a supercharger 52 for supercharging intake air. The supercharger 52 is provided in the intake pipe 2
The compressor 54 provided in the middle of 0 is driven by the turbine 56 provided in the middle of the exhaust pipe 40. An intercooler 58 is provided in the intake pipe 20 between the compressor 54 and the throttle body 22.

The internal combustion engine 2 is provided with an exhaust bypass passage 60 connecting the upstream manifold exhaust passage 42 and the downstream pipe exhaust passage 44 of the turbine 56, and a waste gate valve 62 is provided in the exhaust bypass passage 60. It is provided. The waste gate valve 62 has a link mechanism 64.
To the actuator 66.

An actuator 66 for operating the waste gate valve 62 uses a diaphragm 68 to actuate the pressure chamber 7
The spring 7 is divided in the direction of 0 to reduce the pressure chamber 70.
2 is provided. The diaphragm 68 is connected to the waste gate valve 62 by a link mechanism 64. The pressure chamber 70 is connected to the pipe intake passage 28 on the downstream side of the compressor 54 by the pressure introduction passage 74 and is connected to the pipe intake passage 28 on the upstream side of the compressor 54 by the pressure derivation passage 76. A supercharging pressure adjusting valve 78 is provided in the middle of the pressure derivation passage 76.

The boost pressure adjusting valve 78 is provided in the pressure outlet passage 7.
By opening and closing 6, the pressure chamber 7 of the actuator 66
The supercharging pressure acting through the pressure introduction passage 74 is adjusted to 0, and the waste gate valve 62 is operated to release a part of the exhaust pressure to the pipe exhaust passage 44 downstream of the turbine 56.
The supercharging pressure is regulated so that it does not exceed the full-open supercharging pressure that is the regulation value.

Reference numeral 80 is an air bypass passage, reference numeral 82 is an air bypass valve, reference numeral 84 is a bypass adjusting valve, and reference numerals 86 and 88 are check valves. The bypass adjusting valve 84 adjusts the intake pipe pressure of the body intake passage 30 and the intake pipe pressure and the atmospheric pressure of the tank intake passage 32 via the check valves 86 and 88, and causes the air bypass valve 82 to act. 82 is operated to adjust the amount of air bypass from the downstream side of the compressor 54 to the upstream pipe intake passage 28.

Reference numeral 90 is an EGR passage, and reference numeral 92 is an EGR control valve. The EGR control valve 92 is set to E
The intake pipe pressure of the tank intake passage 32 is introduced through the GR operating pressure passage 94, and the EGR passage 90 is opened / closed to adjust the amount of exhaust gas recirculated to the manifold intake passage 34.

In the internal combustion engine 2, a fuel injection valve 96 is attached to the intake manifold 22 so as to be directed toward the combustion chamber 12. The fuel injection valve 96 is connected to the fuel tank 100 via a fuel supply passage 98. In the fuel tank 100, the fuel pump 10 for supplying fuel to the fuel supply passage 98.
2 is provided. A fuel filter 104 is provided in the fuel supply passage 98.

A regulator 106 for adjusting the fuel pressure is provided in the middle of the fuel supply passage 98. The regulator 106 is connected to the fuel tank 96 by a fuel return passage 108. The regulator 106 introduces the intake pipe pressure of the tank intake passage 32 through the regulator pressure passage 110, adjusts the fuel pressure, and returns excess fuel to the fuel tank 96 through the fuel return passage 108.

The fuel tank 96 has an evaporation passage 112.
Is communicated with the canister 114. The canister 114 uses the purge passage 116 to connect the throttle body 2
It communicates with the second body intake passage 30. Purge passage 1
A one-way check valve 118 is provided in the middle of 16.

One end of an idle air passage 120 communicates with the body intake passage 30 on the upstream side of the throttle valve 36. The other end of the idle air passage 120 communicates with the tank intake passage 32 of the surge tank 24.
An idle adjustment valve (ISC valve) 122 is provided in the middle of the idle air passage 120.

The internal combustion engine 2 includes a tank intake passage 32.
A pressure sensor 126 for introducing and detecting the intake pipe pressure of the above is detected by a detection pressure passage 124, a water temperature sensor 130 for detecting a cooling water temperature of a cooling water passage 128 formed in the intake manifold 22 is provided, and a tank intake of the surge tank 24 is provided. An intake air temperature sensor 132 for detecting the intake air temperature of the passage 32 is provided,
A throttle sensor 134 for detecting the opening position of the throttle valve 36 and the opening / closing speed of the throttle valve 36 is provided so that the O ₂ sensor 13 faces the pipe exhaust passage 44 on the downstream side of the turbine 56.
6 is provided.

The supercharging pressure adjusting valve 78, the bypass adjusting valve 84, the fuel injection valve 96, the fuel pump 100, the idle adjusting valve 122, the pressure sensor 126, the water temperature sensor 130, the intake air temperature sensor 132, and the throttle sensor 134.
The O ₂ sensor 136 and the O ₂ sensor 136 are connected to the control means 140 that constitutes the supercharging pressure control device 138.

The control means 140 includes an ignition mechanism 142.
Distributor 144 and ignition coil 1
46 is connected to the first and second catalysts 46 and 48.
A thermo fuse 148 facing the tube exhaust passage 44 is connected via an alarm relay 150 and a warning lamp 152, and a fuse 154, a main switch 156, and a battery 158 are connected.

Control means 14 of the supercharging pressure control device 138
In 0, as a signal of the operating state of the internal combustion engine 2, for example,
Intake pipe pressure and water temperature sensor 1 detected by the pressure sensor 126
The cooling water temperature detected by 30, the intake air temperature detected by the intake air temperature sensor 132, the opening state of the throttle valve 36 detected by the throttle sensor 134, the oxygen concentration detected by the O ₂ sensor 136, the distributor 144 and the ignition coil 146. The number of revolutions of the internal combustion engine based on the signal is input.

Control means 140 of supercharging pressure control device 138
Controls the supercharging pressure together with the ignition timing and the fuel injection amount of the internal combustion engine 2 by these input signals. This supercharging pressure control device 138 is controlled by the control means 140 so as to regulate the supercharging pressure by the supercharger 52 to the steady full opening supercharging pressure at the time of steady full-open acceleration in which the throttle valve 36 is fully opened at a speed less than a predetermined value. When the throttle valve 36 is fully opened at a speed equal to or higher than a predetermined value, the steady full-charging supercharging pressure that regulates the supercharging pressure by the supercharger 52 is set to a higher side than the steady full-charging supercharging pressure. The full-open supercharging pressure is controlled to be increased for a predetermined time t, and when the supercharging pressure regulation control by the high-side full-open supercharging pressure exceeds the predetermined time t, the high-side full-open supercharging pressure is gradually reduced to a steady state. The control is performed to change to the full open supercharging pressure.

In this embodiment, as shown in FIGS. 1 to 6, when a predetermined time t has elapsed, the high side full-open supercharging pressure is subtracted by a set value Δa every set time Δt, so that the high side is increased. The control is performed such that the full open supercharging pressure is gradually reduced to change to the steady full open supercharging pressure.

Next, the operation of this embodiment will be described.

As shown in FIG. 1, when the control means 140 starts the internal combustion engine 2 and the program starts (step 200), it is in a steady operation state (step 20).
2) If the throttle opening is increasing due to the opening state of the throttle valve 36 detected by the throttle sensor 134 (step 204), acceleration is determined (step 206).

In this judgment (step 206),
It is determined whether the throttle valve 36 is in the steady full-open acceleration in which the throttle valve 36 is fully opened at a speed less than a predetermined value or in the sudden full-open acceleration in which the throttle valve 36 is fully opened at a speed equal to or more than the predetermined value.

In this determination (step 206), when the throttle valve 36 is fully opened at a speed less than a predetermined value and the steady full-open acceleration is performed (step 206: NO), the process returns to (step 202) and the supercharger 52 operates. The supercharging pressure is controlled so as to be regulated to the steady full open supercharging pressure.

As shown in FIG. 2, for example, the control means 140 retrieves and obtains the steady duty value A of the steady full opening supercharging pressure from the characteristics of the steady full opening acceleration supercharging pressure determined by the engine speed. By performing duty control of the boost pressure adjusting valve 78 with the steady duty value A, the pressure leading passage 76 is opened and closed to adjust the boost pressure acting on the pressure chamber 70 of the actuator 66, and the waste gate valve 62 is operated. A part of the exhaust pressure is released to the pipe exhaust passage 44 downstream of the turbine 56, and the supercharging pressure is regulated so as not to exceed a steady-state full-open supercharging pressure that is a regulation value.

In the above determination (step 206), when the throttle valve 36 is fully opened at a speed equal to or higher than a predetermined value for rapid full-open acceleration (step 206: YES), steady full-open acceleration supercharging determined by the engine speed is performed. The steady duty value A is retrieved from the pressure characteristics (step 208),
The correction duty value B for sudden full-open acceleration is searched (step 210), the correction duty value B is added to the steady duty value A, and the high side full open supercharging pressure higher than the steady full opening supercharging pressure is added. Obtain the duty value A + B (step 21)
2).

The correction duty value B is, for example, as shown in FIG.
As shown in, it is obtained from a one-dimensional table determined by the engine speed. In FIG. 3, the correction duty value B
Is set to 1000 rpm, 2000 rpm ... 7
For engine speeds of 000 rpm and 8000 rpm,
x _1, is set the correction duty value of _{x 2 ...... x 7, x 8} . The control means 140 reads the correction duty value x _n corresponding to the set n000 rpm as the correction duty value B according to the engine speed that rises during the sudden full-open acceleration.

The control means 140 includes a throttle valve 36.
Is a full-open acceleration that is fully opened at a speed equal to or higher than a predetermined value (step 206: YES), the steady-state full-open supercharging pressure that regulates the supercharging pressure is regulated by the added total duty value A + B. Increase the high side full open supercharging pressure higher than the supply pressure and keep this high side full opening supercharging pressure for a predetermined time t (step 214) so that the supercharging pressure does not exceed the high side full opening supercharging pressure. Regulate.

As a result, the control means 140 duty-controls the boost pressure adjusting valve 78 for a predetermined time t by the added duty value A + B of the high side full open boost pressure, thereby opening / closing the pressure derivation passage 76 and opening the actuator 66. The supercharging pressure acting on the pressure chamber 70 of the turbine 56 is adjusted, and the waste gate valve 62 is operated to partially discharge the exhaust pressure of the turbine 56.
Is discharged to the pipe exhaust passage 44 on the downstream side, and the supercharging pressure is regulated so as not to exceed the high-side full-open supercharging pressure which is a regulation value higher than the steady full-open supercharging pressure.

When a predetermined time t of the regulation control of the supercharging pressure by the high-side full-open supercharging pressure in the above (step 214) has elapsed, as shown in FIG. 4, the correction duty value B (the predetermined time t when the predetermined time t has elapsed). Engine speed n over time
The set value Δa is subtracted from the corrected duty value x _n corresponding to 000 rpm for each set time Δt (step 21
6) It is determined whether the corrected duty value B has become zero "0" (step 218).

When the corrected duty value B is larger than zero (step 218: B> 0), the value is held for the set time Δt (step 220) and (step 216).
Return to In (step 216), when the set time Δt elapses, the set value Δa is further subtracted from the corrected duty value B. Subtraction of the set value Δa from the corrected duty value B for each set time Δt (step 216)
Until the correction duty value B becomes zero (step 21
8: B ≦ 0) Implemented. If the value does not become zero in the calculation, the value that approaches the value of zero is truncated to be zero.

As a result, the control means 140 subtracts the set value Δa from the high-side full-open supercharging pressure for each set time Δt when the regulation control of the supercharging pressure by the high-side full-open supercharging pressure has passed the predetermined time t. As a result, the high-side full-open supercharging pressure is gradually reduced and controlled to change to the steady full-open supercharging pressure.

When the corrected duty value B becomes zero (step 218: B≤0), the supercharging pressure is regulated by the steady duty value A of the steady full opening supercharging pressure so as not to exceed the steady full opening supercharging pressure. (Step 222) and (Step 202)
Return to This control ends (step 224) when the internal combustion engine 2 is stopped.

As described above, the supercharging pressure control device 138 uses the control means 140 to control the steady full opening supercharging pressure that regulates the supercharging pressure during rapid full opening acceleration in which the throttle valve 36 is fully opened at a speed equal to or higher than a predetermined value. Control is performed such that the high side full opening supercharging pressure higher than the steady full opening supercharging pressure is increased for a predetermined time t,
When the regulation control of the supercharging pressure by the high-side full-open supercharging pressure has passed a predetermined time t, the high-side full-open supercharging pressure is gradually reduced to a steady full-open supercharging pressure so that the vehicle is controlled. It is possible to prevent the supercharging pressure from being sharply reduced during the acceleration operation of, and it is possible to smoothly reduce the high-side full-open supercharging pressure and change it to the steady-state full-open supercharging pressure.

Therefore, the supercharging pressure control device 138 is
As shown in FIG. 5, when the throttle valve 36 is fully opened at a speed equal to or higher than a predetermined value, the steady full supercharging pressure (broken line) that regulates the supercharging pressure by the supercharger 52 is set to the steady full opening supercharging pressure. When the predetermined time t elapses by controlling the high side full-open supercharging pressure on the higher side (solid line) to increase for a predetermined time,
By controlling to gradually decrease the high-side full open supercharging pressure and gradually change it to the steady full open supercharging pressure, it is possible to prevent the supercharging pressure from being sharply lowered during the acceleration operation of the vehicle, and to make it smooth. The high-side full open supercharging pressure can be reduced to change to the steady full open supercharging pressure.

As a result, this boost pressure control device 138
As shown in FIG. 6, it is possible to prevent a rapid decrease in supercharging pressure (dashed line) during acceleration operation of a conventional vehicle, to smoothly decrease supercharging pressure (solid line), and to generate a torque shock. Can be prevented, and drivability can be improved.

When the regulation control of the supercharging pressure by the high side full opening supercharging pressure has passed the predetermined time t, the high side full opening supercharging pressure is gradually reduced to the steady full opening supercharging pressure. Not only the embodiment but also, for example, as shown in FIG. 7 and FIG.

(Step 200) to (Step 2) of FIG.
14) and (step 218) to (step 224)
1 is the same processing as (Step 200) to (Step 214) and (Step 218) to (Step 224) in FIG. 1, so that the characteristic (Step 216) will be mainly described.

That is, in (step 216) of FIG. 7, when a predetermined time t of the regulation control of the supercharging pressure by the high side full open supercharging pressure in (step 214) has elapsed, as shown in FIG. Corrected duty value B when elapsed
(Engine speed n000 rpm after a predetermined time t has elapsed
The correction duty value x _n ) corresponding to is multiplied by the setting coefficient K for each set time Δt, and it is determined whether or not the correction duty value B becomes zero "0" (step 218). The setting coefficient K is set to 0 ≦ K ≦ 1.

When the corrected duty value B is larger than zero (step 218: B> 0), the value is held for the set time Δt (step 220) and (step 216).
Return to In (step 216), when the set time Δt has elapsed, the correction duty value B is further multiplied by the set coefficient K. This correction duty value B is multiplied by the setting coefficient K for each set time Δt (step 216) until the correction duty value B becomes zero (step 218: B
≦ 0) performed.

As a result, when the regulation control of the supercharging pressure by the high-side full-open supercharging pressure has passed the predetermined time t, the setting coefficient K is multiplied from the high-side full-open supercharging pressure at every set time Δt, so that the above-mentioned operation is performed. It is possible to control to gradually reduce the high-side full-open supercharging pressure at a change rate different from the example to change to the steady full-open supercharging pressure.

Therefore, the supercharging pressure control device 138 is
The same effects as those of the above-described embodiment can be obtained, and the high-side full-open supercharging pressure can be gradually reduced in a curve to be changed to the steady-state full-open supercharging pressure. The change can be smoothly decreased, and the high-side full open supercharging pressure can be smoothly decreased to change to the steady full open supercharging pressure.

As a result, the boost pressure control device 138
Can prevent a rapid decrease in supercharging pressure during acceleration of the vehicle, prevent torque shock from occurring, and improve drivability.

The setting coefficient K can be set so that the sudden full opening supercharging pressure shown by the solid line in FIG. 5 is smoothly changed to the steady full opening supercharging pressure shown by the broken line. As a result, the change in the supercharging pressure during the acceleration operation of the vehicle can be reduced more smoothly, and the high-side full-open supercharging pressure can be smoothly reduced to the steady full-open supercharging pressure. It is possible to prevent a sudden decrease in the supercharging pressure during the acceleration operation, and to prevent the occurrence of a torque shock, thereby improving drivability.

[0054]

As described above, according to the present invention, the supercharging pressure control device has the high-side full-open supercharging pressure when the regulation control of the supercharging pressure by the high-side full-open supercharging pressure has passed the predetermined time. Is controlled to gradually change to a low-side steady-state full-open supercharging pressure so that the supercharging pressure does not drop sharply during the acceleration operation of the vehicle as in the past, and it smoothly The full open supercharging pressure can be reduced to change to the steady full open supercharging pressure.

Therefore, the supercharging pressure control device can prevent a rapid decrease in the supercharging pressure during acceleration of the vehicle.
It is possible to prevent the occurrence of torque shock and improve drivability.

[Brief description of drawings]

FIG. 1 is a flowchart of boost pressure control showing an embodiment of the present invention.

FIG. 2 is a diagram showing characteristics of a steady full supercharging pressure.

FIG. 3 is a diagram showing a table of correction duty values at the time of sudden full-open acceleration.

FIG. 4 is a diagram showing set values when gradually reducing the high-side full-open supercharging pressure.

FIG. 5 is a timing chart of throttle opening, supercharging pressure, and engine speed.

FIG. 6 is a diagram showing a torque when gradually reducing the high-side full-open supercharging pressure.

FIG. 7 is a flowchart of supercharging pressure control showing another embodiment of the present invention.

FIG. 8 is a diagram showing a setting coefficient when the high-side full-open supercharging pressure is gradually reduced.

FIG. 9 is a system configuration diagram of a supercharging pressure control device.

FIG. 10 is a timing chart of throttle opening, supercharging pressure and engine speed showing a conventional example.

FIG. 11 is a diagram showing a torque when reducing the high-side full-open supercharging pressure.

[Explanation of symbols]

 2 Internal combustion engine 36 Throttle valve 52 Supercharger 62 Waste gate valve 66 Actuator 78 Supercharging pressure adjusting valve 134 Throttle sensor 138 Supercharging pressure control device 140 Control means

Claims (1)

[Claims] 1. A supercharger for supercharging intake air is provided in an internal combustion engine, a throttle sensor for detecting an opening state of a throttle valve of the internal combustion engine is provided, and the throttle valve is fully opened at a speed lower than a predetermined value. During steady full-open acceleration, the supercharging pressure by the supercharger is controlled to be regulated to the steady full-open supercharging pressure, and when the throttle valve is fully opened at a speed equal to or higher than a predetermined value, the supercharging pressure by the supercharger is controlled. The above-mentioned steady full opening supercharging pressure is controlled to be increased to a high side full opening supercharging pressure higher than this steady full opening supercharging pressure for a predetermined time, and the high side full opening supercharging pressure is increased to this high side. An internal combustion engine provided with a control means for controlling to gradually reduce the high-side full-open supercharging pressure to change to the steady-state full-open supercharging pressure when the regulation control of the supercharging pressure exceeds a predetermined time. Boost pressure control device.