JPH05231164A - Supercharge pressure controller for internal combustion engine equipped with exhaust turbine supercharger - Google Patents

Abstract

PURPOSE:To suppress the generation of the uncombustible HC and particulates and prevent the increase of supercharge pressure over the allowable max. value by the simple device constitution having high reliability, as for a supercharge pressure controller for a Diesel engine equipped with an exhaust turbine supercharger. CONSTITUTION:An all-time closed type bypass control valve 12 is arranged in a bypass passage 10 which makes a detour around an exhaust turbine. The actuator 14 of the control valve 12 is equipped with a supercharge pressure chamber 20 and an atmospheric pressure chamber 22 which are dividedly formed by a diaphragm 18. The supercharge pressure chamber 20 is connected to an intake passage on the downstream side of a compressor through a supercharge pressure introducing passage 36, and when the supercharge pressure increases over a certain supercharge pressure, the control valve 12 is opened through a link mechanism 30. An accelerator interlocked rod 40 is connected with an accelerator pedal 46 through an accelerator link 44, and when the stepping-ON quantity of the accelerator pedal 46 is leas than a certain stepping-ON quantity, the second rod 26 is pushed rightward by the accelerator interlocked rod 40, and the control valve 12 is opened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boost pressure control system for an internal combustion engine equipped with an exhaust turbine supercharger.

[0002]

2. Description of the Related Art An exhaust turbine supercharger having an exhaust turbine arranged in an engine exhaust passage and a compressor connected to the exhaust turbine and arranged in the engine intake passage is provided, and intake air downstream of the compressor is provided. Place a throttle valve in the passage,
A bypass passage is branched from the exhaust passage upstream of the exhaust turbine to connect the bypass passage to the exhaust passage downstream of the exhaust turbine, and a normally closed bypass control valve controlled by an actuator is provided in the bypass passage, that is, a so-called waste gate valve. A supercharging pressure control device for an internal combustion engine equipped with an exhaust turbine supercharger is known (see Japanese Patent Laid-Open No. 56-522). In this internal combustion engine with an exhaust turbine supercharger, an actuator for controlling the above-mentioned bypass control valve, a diaphragm connected to the bypass control valve via a valve rod,
It has a first pressure chamber and a second pressure chamber that are separated by this diaphragm. A compression spring for urging the diaphragm toward the closing direction of the bypass control valve is provided in the first pressure chamber, and the first pressure chamber is provided with a first switching passage and an electromagnetic switching valve capable of communicating with the atmosphere. It is connected to the intake passage downstream of the throttle valve. On the other hand, the second pressure chamber is the second
Is connected to the intake passage between the compressor and the throttle valve. Normally, the bypass control valve is held in the closed state by the spring force of the compression spring provided in the first pressure chamber, so that the exhaust gas exhausted from the engine cylinder is made to flow into the exhaust turbine at this time.

On the other hand, when the engine is operated at a low load with a small opening of the throttle valve, the pressure difference between the upstream side and the downstream side of the throttle valve increases, and a large negative pressure is generated in the intake passage downstream of the throttle valve. The negative pressure generated in the intake passage downstream of the throttle valve is guided into the first pressure chamber of the actuator via the first communication passage, while the pressure generated in the intake passage upstream of the throttle valve is passed through the second communication passage. Are introduced into the second pressure chamber. Thus, during engine low load operation, the pressure difference between the pressure in the first pressure chamber and the pressure in the second pressure chamber increases, and as a result, the bypass control valve is opened against the spring force of the compression spring. As a result, a part of the exhaust gas discharged from the engine cylinder bypasses the exhaust turbine and flows in the bypass passage, so that the amount of exhaust gas flowing into the exhaust turbine is reduced, and as a result, it is supercharged by the compressor. The supercharging pressure can be reduced. Even if the exhaust gas amount is small and the engine is operated under a low load and the exhaust gas is exhausted into the exhaust turbine for supercharging, the supercharging pressure does not rise sufficiently because the exhaust gas amount is small. Instead, the pressure of the exhaust gas rises due to the driving of the exhaust turbine, and as a result, the engine output rather decreases. However, in this internal combustion engine with an exhaust turbine supercharger, as described above, a portion of the exhaust gas flows around the exhaust turbine during low engine load operation, so it is possible to prevent the engine output from decreasing.

Further, in this internal combustion engine with an exhaust turbine supercharger, when the supercharging pressure exceeds a predetermined constant supercharging pressure during the engine high speed and high load operation, the first operation is performed by the switching action of the electromagnetic switching valve. The pressure chamber is opened to the atmosphere, and as a result, the bypass control valve is opened to allow a part of the exhaust gas to bypass the exhaust turbine. In this way, the supercharging pressure is controlled so as not to exceed a predetermined constant supercharging pressure. As a result, the supercharging pressure is prevented from exceeding the design strength of each part of the engine, and in particular, the combustion pressure does not exceed the maximum allowable pressure and the engine speed does not exceed the dangerous engine speed.

[0005]

In the internal combustion engine with the exhaust turbine supercharger, as described above, the engine is always closed when the engine is operating at low load and when the supercharging pressure exceeds a certain supercharging pressure at high engine speed and high load. The bypass control valve is opened. However, for that purpose, it is necessary to control the switching of the electromagnetic switching valve arranged in the first communication passage in accordance with the supercharging pressure as described above. Therefore, an electronic control device for controlling the switching of the electromagnetic switching valve and It is necessary to provide a detection means for detecting the boost pressure. As a result, the supercharging pressure control device becomes complicated as a whole, and there is a problem that reliability is reduced. Further, as described above, the bypass control valve is opened by using the pressure difference between the upstream side and the downstream side of the throttle valve during engine low load operation. There is a problem that the boost pressure control device cannot be applied.

[0006]

In order to solve the above problems, according to the present invention, an exhaust turbine disposed in an engine exhaust passage and a compressor connected to the exhaust turbine and disposed in the engine intake passage. In an internal combustion engine with an exhaust turbine supercharger, the bypass passage for connecting the exhaust passages upstream and downstream of the exhaust turbine or the bypass passage for connecting the intake passages downstream and upstream of the compressor with each other is provided in the bypass passage. A normally closed bypass control valve, which is controlled by an actuator, is arranged in the compressor, and the bypass control valve is opened when the supercharging pressure generated in the intake passage downstream of the compressor exceeds a predetermined constant supercharging pressure. In addition, the depression amount of the accelerator pedal is less than the depression amount of the accelerator pedal that generates the above-mentioned predetermined constant supercharging pressure. Provide interlocking means for interlocking the bypass control valve with the accelerator pedal only when the predetermined depression amount is less than or equal to a predetermined depression amount, and through the interlocking device when the depression amount of the accelerator pedal is equal to or less than the predetermined constant depression amount. The bypass control valve is opened.

[0007]

The bypass control valve is opened when the supercharging pressure generated in the intake passage downstream of the compressor exceeds a predetermined constant supercharging pressure. Further, when the depression amount of the accelerator pedal is equal to or smaller than a predetermined constant depression amount, the bypass control valve is made to interlock with the accelerator pedal through the interlocking means, and as a result, the bypass control valve is opened. When the bypass control valve is opened in this way and when a bypass passage is provided in the exhaust passage, part of the exhaust gas discharged from the engine cylinder flows in the bypass passage so as to bypass the exhaust turbine, while When the bypass passage is provided in the passage, a part of the air discharged from the compressor is returned to the intake passage upstream of the compressor through the bypass passage. As a result, the boost pressure can be reduced in any case.

[0008]

1 and 2 show the case where the present invention is applied to a diesel engine with an exhaust turbine supercharger. Referring to FIG. 1, 1 is an engine body, 2 is an intake manifold,
Reference numeral 3 is an exhaust manifold, 5 is an intake passage connected to the intake manifold 2, 6 is an exhaust passage connected to the exhaust manifold 3, and 8 is an exhaust turbine supercharger. The exhaust turbine supercharger 8 is an exhaust turbine 8a arranged in the exhaust passage 6.
And a compressor 8b arranged in the intake passage 5, and the exhaust turbine 8a and the compressor 8b are directly connected to each other. The bypass passage 10 is branched from the exhaust passage 6 upstream of the exhaust turbine 8a, and the bypass passage 10 is connected to the exhaust passage 6 downstream of the exhaust turbine 8a. A normally closed bypass control valve 1 is provided in the bypass passage 10.
2, a so-called waste gate valve 12 is arranged, and this bypass control valve 12 is controlled by an actuator 14. In FIG. 1, each arrow indicates the flow of intake air or the flow of exhaust gas.

Next, the configurations of the bypass control valve 12 and its actuator 14 will be described with reference to FIGS. 1 and 2. As shown in FIG. 2, the actuator 14
Includes a diaphragm 18 that is hermetically mounted in the housing 16, and a supercharging pressure chamber 20 and an atmospheric pressure chamber 22 that are separated by the diaphragm 18. A first rod 24 extending through the atmospheric pressure chamber 22 and a second rod 26 arranged in the supercharging pressure chamber 20 are fixed to the central portion of the diaphragm 18, respectively. As shown in FIG. 2, the first rod 24 and the second rod 26 are connected to the housing 1
6 are arranged coaxially with each other. First
The rod 24 is connected via the link member 28 to the bypass control valve 1
Connected to 2. Therefore, the first rod 24 and the link member 28 form a link mechanism 30 that connects the bypass control valve 12 and the diaphragm 18. Atmospheric pressure chamber 2
A second compression spring 32 for urging the diaphragm 18 toward the valve closing direction of the bypass control valve 12 is provided inside the valve 2. On the other hand, a supercharging pressure introducing hole 34 is formed on the wall surface of the housing 16 forming the supercharging pressure chamber 20, and the supercharging pressure introducing hole 34 is provided through the supercharging pressure introducing passage 36 to the intake air downstream of the compressor 8 b. It is connected to the passage 5 (see FIG. 1). Therefore compressor 8
The supercharging pressure P generated in the intake passage 5 downstream of the compressor 8b by compressing the intake air by b is introduced into the supercharging pressure chamber 20 of the actuator 14 through the supercharging pressure introducing passage 36. Therefore, the bypass control valve 12 is normally held in the closed state by the spring force of the first compression spring 32, and when the supercharging pressure P exceeds a predetermined constant supercharging pressure P ₀ , the bypass control valve 12 becomes the first The valve is opened against the spring force of the compression spring 32.

A cylindrical guide member 38 is fixed on the inner end surface of the housing 16 forming the supercharging pressure chamber 20. The guide member 38 is arranged so as to be coaxial with the above-mentioned second rod 26 fixed to the diaphragm 18. A stepped cylindrical accelerator interlocking rod 40 is axially slidably arranged in the guide member 38, and a second recess is formed in a recess 40a formed on the end surface of the large diameter portion of the accelerator interlocking rod 40. The rod 26 is adapted to be inserted. Therefore, the diaphragm 18, the first rod 24, the second rod 26, and the accelerator interlocking rod 40
Are arranged coaxially. An accelerator link connecting member 42 is fixed on the end of the accelerator interlocking rod 40 protruding from the end surface of the housing 16, one end of an accelerator link 44 is connected to the accelerator link connecting member 42, and the other end of the accelerator link 44 is an accelerator. It is connected to the pedal 46. A second compression spring 48 that urges the accelerator interlocking rod 40 toward the diaphragm 18 is provided between the stepped end surface of the accelerator interlocking rod 40 and the inner end surface of the housing 16 that faces the stepped end end surface. Is inserted. Therefore, the accelerator interlocking rod 40 is always interlocked with the accelerator pedal 46 via the accelerator link 44, and the smaller the depression amount L of the accelerator pedal 46 is, the closer the accelerator interlocking rod 40 is to the diaphragm 18, that is, to the right in FIG. It is designed to be used.
In the embodiment shown in FIGS. 1 and 2, when the depression amount L of the accelerator pedal 46 is smaller than a predetermined constant depression amount L ₀ , the bottom surface 40b of the recess 40a of the accelerator interlocking rod 40 has the second rod 26, as will be described later. End face 26a of
As a result, the bypass control valve 12 is made to interlock with the accelerator pedal 46 and open.

In the embodiment shown in FIGS. 1 and 2, fuel is injected from a fuel injection valve (not shown) into the engine combustion chamber. The fuel injection amount injected from this fuel injection valve is determined based on the depression amount L of the accelerator pedal 46 and the engine speed N. As the overall tendency of the fuel injection amount, when the engine speed N is the same, the fuel injection amount increases as the depression amount L of the accelerator pedal 46 increases, and when the depression amount L of the accelerator pedal 46 is the same, the engine rotation speed. The fuel injection amount increases as N increases. When the fuel injection amount increases, the amount of exhaust gas discharged from the engine combustion chamber also increases. As a result, the output of the exhaust turbine supercharger 8 increases and the supercharging pressure P in the intake passage 5 downstream of the compressor 8b rises. As a result, the engine load is increased. Therefore, in the embodiment shown in FIGS. 1 and 2, as the overall tendency of the boost pressure P, the boost pressure P increases as the depression amount L of the accelerator pedal 46 increases when the engine speed N is the same, and the accelerator pressure P increases. When the depression amount L of the pedal 46 is the same, the boost pressure P increases as the engine speed N increases.

Next, the operation of the supercharging pressure control device shown in FIGS. 1 and 2 will be described with reference to FIGS. Note that FIG. 3 shows an operating state during engine low load operation, FIG. 4 shows an operating state during engine medium load operation, and FIG. 5 shows an operating state during engine high rotation and high load operation. There is. As mentioned above, accelerator interlocking rod 4
0 is the accelerator pedal 4 at all times via the accelerator link 44.
6, the accelerator interlocking rod 40 is moved to the right side in FIG. 3 as the depression amount L of the accelerator pedal 46 becomes smaller. When the depression amount L of the accelerator pedal 46 is reduced to a predetermined constant depression amount L _{0, the} bottom surface 40b of the recess of the accelerator interlocking rod 40 is brought into contact with the end surface 26a of the second rod 26. The amount L of depression of the accelerator pedal 46 is the constant amount L of depression.
_When it becomes smaller than _0, the second rod 26 is moved as the accelerator interlocking rod 40 is moved further to the right.
Then, the first rod 24 is pushed by the accelerator interlocking rod 40 and moved to the right side, and as a result, the bypass control valve 12 is opened via the link member 28 as shown in FIG. In this way, during the engine low load operation in which the depression amount L of the accelerator pedal 46 is smaller than the constant depression amount L ₀ , that is, when the engine operating state is in the engine low load operating region Rr shown in FIG. The valve is opened in conjunction with the pedal 46. Further, in the engine low load operation region Rr, the accelerator pedal 46
The smaller the depression amount L of the bypass control valve 1
The opening degree of 2 becomes larger. The boundary line B ₁ shown in FIG. 6 corresponds to the engine operating state in which the depression amount L of the accelerator pedal 46 is equal to the constant depression amount L ₀ .

When the bypass control valve 12 is opened during the engine low load operation as described above, a part of the exhaust gas discharged from the engine combustion chamber flows through the bypass passage 10 as shown by an arrow W in FIG. It flows and is discharged into the exhaust passage 6 downstream of the exhaust turbine 8a. That is, a part of the exhaust gas discharged from the engine combustion chamber bypasses the exhaust turbine 8a and flows. Therefore, the amount of exhaust gas flowing into the exhaust turbine 8a is reduced, and as a result, the exhaust turbine 8a and the compressor 8
The rotation speed of b is reduced, and thus the boost pressure P in the intake passage 5 downstream of the compressor 8b is reduced. If the exhaust gas discharged from the engine combustion chamber during the engine low load operation is made to flow entirely into the exhaust turbine 8a, the supercharging pressure P becomes too high and the air-fuel mixture formed in the engine combustion chamber becomes lean. As a result, the combustion temperature lowers and a large amount of unburned HC and particulates are generated. Further, since the amount of exhaust gas is small during engine low load operation, the supercharging efficiency by the exhaust turbine supercharger 8 is relatively low. Therefore, at this time, all the exhaust gas is exhausted from the exhaust turbine 8a.
The exhaust turbine 8
There is also a problem that the engine output is greatly affected by the increase in the exhaust gas pressure due to the driving of a, and as a result, the engine output is rather decreased. On the other hand, in the embodiment shown in FIGS. 1 and 2, the bypass control valve 12 is opened during engine low load operation so that a part of the exhaust gas flows around the exhaust turbine 8a. P is decreased, and as a result, the air-fuel ratio of the air-fuel mixture formed in the engine combustion chamber is decreased, and thus the combustion temperature is increased, so that the generation of unburned HC and particulates can be suppressed. Further, a part of the exhaust gas is bypassed to the exhaust turbine 8a, so that the reduction of the engine output can be prevented.

From the state shown in FIG. 3, the accelerator pedal 4
When 6 is depressed, the accelerator interlocking rod 40 is moved to the left side in FIG. 3 as the depression amount L of the accelerator pedal 46 increases. At this time, the first rod 2
The fourth and second rods 26 are moved to the left by following the movement of the accelerator interlocking rod 40 by the spring force of the first compression spring 32, and as a result, the opening degree of the bypass control valve 12 is reduced. Next, when the depression amount L of the accelerator pedal 46 increases to the above-mentioned constant depression amount L ₀ , the bypass control valve 12 is closed. Next, when the depression amount L of the accelerator pedal 46 becomes larger than the constant depression amount L ₀ , the accelerator interlocking rod 40 is moved further to the left side, and as a result, as shown in FIG. The end surface 26a of the 2 rod 26 separates. Therefore, in the engine operating region where the depression amount L of the accelerator pedal 46 is larger than the constant depression amount L ₀ , that is, in the engine operating region above the boundary line B ₁ in FIG. Is released, and as a result, the bypass control valve 12 is operated independently of the accelerator pedal 46. At this time, the bypass control valve 12 is opened / closed according to the pressure in the supercharging pressure chamber 20, that is, the supercharging pressure P in the intake passage 5 downstream of the compressor 8b. When the supercharging pressure P is equal to or lower than a predetermined constant supercharging pressure P ₀ , that is, when the engine operating state is in the engine operating region R _m shown in FIG. 6, the bypass control valve 12 is set as shown in FIG. The closed state is maintained by the spring force of the first compression spring 32. In this way, during the engine medium load operation and the engine low speed high load operation, the bypass control valve 12 is kept closed, and as a result, all the exhaust gas discharged from the engine combustion chamber is caused to flow into the exhaust turbine 8a. .. As a result, the intake air can be supercharged to the maximum capacity of the exhaust turbine supercharger 8, so that the supercharging pressure P can be favorably increased and thus the engine output can be improved.

On the other hand, when the pressure in the supercharging pressure chamber 20, that is, the supercharging pressure P exceeds the above constant supercharging pressure P ₀ , the diaphragm 18 receives the supercharging pressure P as shown in FIG. 5 is deformed to the right in FIG. 5 against the spring force of the first compression spring 32, and as a result, the bypass control valve 1
2 is opened. In the embodiment shown in FIGS. 1 and 2, the boost pressure P increases as the amount L of depression of the accelerator pedal 46 increases and the engine speed N increases as described above. Hence the engine operating state is the bypass control valve 12 against the spring force of the first compression spring 32 opens when in the high engine speed and high load operating region R _h shown in FIG. The boundary line B ₂ shown in FIG. 6 corresponds to the engine operating state in which the supercharging pressure P reaches the constant supercharging pressure P ₀ when the bypass control valve 12 is closed. Thus, when the bypass control valve 12 is opened when the supercharging pressure P exceeds the constant supercharging pressure P ₀ , a part of the exhaust gas discharged from the engine combustion chamber bypasses the exhaust turbine 8a. Flow, and as a result, the rotation speeds of the exhaust turbine 8a and the compressor 8b are reduced, and as a result, the supercharging pressure P is reduced. When the supercharging pressure P is reduced to the constant supercharging pressure P _{0 in} this way, the bypass control valve 12 is closed again by the spring force of the first compression spring 32. Therefore, the bypass control valve 12 is operated so that the supercharging pressure P is maintained at the predetermined constant supercharging pressure P ₀ in the engine high rotation and high load operation region R _h . This constant supercharging pressure P ₀ , that is, the valve opening pressure of the bypass control valve 12 is the first compression spring 32 as can be seen from the above description.
The spring force of the first compression spring 32 is determined so that the constant supercharging pressure P ₀ becomes the maximum supercharging pressure allowed by the engine. Thus, it is possible to prevent the combustion pressure from exceeding the maximum allowable pressure or the engine speed N from exceeding the dangerous engine speed.

As described above, in the embodiment shown in FIGS. 1 to 6, the depression amount L of the accelerator pedal 46 is a constant depression amount L.
_The normally closed bypass control valve 12 is opened during the engine low load operation smaller than ₀ and during the engine high speed high load operation in which the supercharging pressure P exceeds the constant supercharging pressure P ₀ . At this time, the supercharging pressure P is simple as described above without using an electromagnetic switching valve, a sensor for detecting supercharging pressure, an electronic control device for switching control of the electromagnetic switching valve, or the like.
Can be controlled, so that high reliability can be secured.

Next, another embodiment will be described with reference to FIG. The same reference numerals are used for the same components as those of the embodiment shown in FIGS. 1 and 2. In the embodiment shown in FIGS. 1 and 2, the bypass passage 10 that bypasses the exhaust turbine 8a is provided, but in the embodiment shown in FIG. 7, a bypass passage 60 that bypasses the compressor 8b is used instead.
Is provided. That is, as shown in FIG. 7, the bypass passage 60 is branched from the intake passage 5 downstream of the compressor 8b, and the bypass passage 60 is connected to the intake passage 5 upstream of the compressor 8b. A normally closed bypass control valve 12 is arranged in the bypass passage 60, and the bypass control valve 12 is controlled by an actuator 14. These bypass control valve 12, actuator 14, boost pressure introducing passage 36 and accelerator link 44 are shown in FIGS.
It has the same structure as the embodiment shown in FIG.

In the embodiment shown in FIG. 7, the bypass control valve 12 is opened and closed as in the case of the embodiment shown in FIGS. That is, the depression amount L of the accelerator pedal 46
Is smaller than the constant depression amount L ₀ , the bypass control valve 12 is opened by being linked with the accelerator pedal 46 during engine low load operation. Further, when the supercharging pressure P exceeds the constant supercharging pressure P ₀ during the engine high speed / high load operation, the bypass control valve 12 is opened by the supercharging pressure P. On the other hand, in the engine operating states other than these engine operating states, the bypass control valve 12 is kept closed by the spring force of the first compression spring 32. When the bypass control valve 12 is opened, the compressor 8b
A part of the air discharged from is returned to the intake passage 5 upstream of the compressor 8b via the bypass passage 60. Thus, as in the case of the embodiment shown in FIGS. 1 and 2, when the bypass control valve 12 is opened, the supercharging pressure P in the intake passage 5 downstream of the compressor 8b is reduced.

Although the present invention has been described so far as applied to a diesel engine with an exhaust turbine supercharger, the present invention can also be applied to a spark ignition internal combustion engine with an exhaust turbine supercharger.

[0020]

The bypass control valve is opened when the accelerator pedal depression amount is equal to or less than a predetermined constant depression amount, thereby reducing the supercharging pressure in the intake passage downstream of the compressor. It is possible to suppress the generation of unburned HC and particulates. Further, by opening the bypass control valve when the supercharging pressure exceeds a predetermined constant supercharging pressure, the supercharging pressure is prevented from exceeding the constant supercharging pressure. Thus, it is possible to prevent the engine combustion pressure from exceeding the maximum allowable pressure or the engine speed from exceeding the dangerous speed. Further, such supercharging pressure control can be performed with a simple configuration without using a sensor for detecting the supercharging pressure, an electromagnetic switching valve, an electronic control device for switching control of the electromagnetic switching valve, or the like. , High reliability can be secured.

[Brief description of drawings]

FIG. 1 is an overall view of a diesel engine with an exhaust turbine supercharger.

FIG. 2 is a side sectional view showing details of a bypass control valve and its actuator.

FIG. 3 is a side sectional view similar to FIG. 2 for explaining the operation of the bypass control valve and the actuator during engine low load operation.

FIG. 4 is a side sectional view similar to FIG. 2 for explaining the operation of the bypass control valve and the actuator during engine medium load operation and engine low rotation and high load operation.

FIG. 5 is a side sectional view similar to FIG. 2 for explaining the operation of the bypass control valve and the actuator at the time of high engine rotation and high load operation.

FIG. 6 is a diagram showing an engine operating region in which the bypass control valve opens and an engine operating region in which the bypass control valve closes.

FIG. 7 is an overall view showing another embodiment of a diesel engine with an exhaust turbine supercharger.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine main body 5 ... Intake passage 6 ... Exhaust passage 8 ... Exhaust turbine supercharger 8a ... Exhaust turbine 8b ... Compressor 10 ... Bypass passage 12 ... Bypass control valve 14 ... Actuator 18 ... Diaphragm 36 ... Supercharging pressure introduction passage 44 … Accelerator link 46… Accelerator pedal 60… Bypass passage

Claims (1)

[Claims] 1. An internal combustion engine with an exhaust turbine supercharger, comprising: an exhaust turbine arranged in an engine exhaust passage; and a compressor connected to the exhaust turbine and arranged in an engine intake passage. A bypass passage for connecting the upstream and downstream exhaust passages or a bypass passage for connecting the downstream and upstream intake passages of the compressor with each other is provided, and a normally closed bypass control valve controlled by an actuator is arranged in the bypass passage. However, when the supercharging pressure generated in the intake passage downstream of the compressor exceeds a predetermined constant supercharging pressure, the bypass control valve is opened and the depression amount of the accelerator pedal is Below a predetermined constant depression amount that is smaller than the depression amount of the accelerator pedal that generates the predetermined constant supercharging pressure Only when the bypass control valve is interlocked with the accelerator pedal, interlocking means is provided, and the bypass control valve is opened via the interlocking means when the accelerator pedal depression amount is equal to or less than the predetermined constant depression amount. Boost pressure control device for internal combustion engine with exhaust turbine supercharger.