JPH0311125A - Control of internal combustion engine equipped with exhaust turbine supercharger and device therefor - Google Patents

Abstract

PURPOSE:To hasten the operation start point of an actuator by reducing the back pressure for the supercharge pressure by acting the negative pressure on the downstream side of a throttle onto an actuator for operating a waste gate valve. CONSTITUTION:In the state where the change through the lapse of time of the operation state of an internal combustion engine 20 is gentle, the pressure in the negative pressure chamber 10b of an actuator 10 for operating a waste gate valve 9 is held at atmospheric pressure. When a throttle 6 is close sharply in the state where the internal combustion engine 20 is operated at a high revolution speed, the negative pressure generated on the downstream side of the throttle 6 is transmitted to the negative pressure chamber 10b through a communication pipe 25. Then, a diaphragm 11 is shifted, and the closing of a bypass pipe 8 is opened by a waste gate valve 9. Therefore, the revolution due to the inertia of a supercharger 7 in the case when the throttle valve 6 is closed can be reduced speedily by hastening the operation start point of the actuator 10.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method and device for controlling an internal combustion engine with an exhaust turbine supercharger, and is particularly suitable for an internal combustion engine installed in a vehicle such as an automobile. This invention relates to the control method and device used.

BACKGROUND OF THE INVENTION Generally, in internal combustion engines installed in vehicles such as automobiles, a supercharger that compresses intake air to increase intake air density is installed in order to increase output. .

One of the superchargers drives a compressor using the dynamic energy and thermal energy of the exhaust gas of the internal combustion engine,
There is an exhaust turbine supercharger that compresses intake air using this compressor. As a conventional example of an internal combustion engine equipped with this exhaust turbine supercharger, one having the structure shown in Fig. 3 is known. There is.

This internal combustion engine 1 has a large number (four in the illustrated example) of cylinders 2 (
2a to 2d), an intake pipe 4 and an exhaust pipe 5 connected to the internal combustion engine main body 3, a throttle 6 provided in the intake pipe 4, and an upstream side of the intake pipe 4. and an exhaust turbine supercharger 7 provided between the exhaust pipe 5 and the downstream side of the exhaust pipe 5; Bypass pipe 8 and this bypass passage 8
A waste gate valve 9 is provided in the intake pipe 4 between the exhaust turbine supercharger 7 and the throttle 6, and the waste gate valve 9 opens and closes the bypass pipe 8. An actuator 10 that operates the gate valve 9 is provided.

The actuator 10 is internally divided into two parts: a positive pressure chamber 10a that communicates with the intake pipe 4, and a negative pressure chamber 10b that is partitioned by the positive pressure chamber 10a and a diaphragm 11 and communicates with the atmosphere. The diaphragm 11 is connected to the wastegate valve 9 via a linkage 12.

When the throttle 6 of the internal combustion engine 1 is opened and the rotational speed Ne rises, and the flow becomes higher than the original model in which the exhaust pipe 5 flows, the dynamic energy and thermal energy of the exhaust gas are used to generate the exhaust turbine supercharger 7. A turbine 7a disposed in the exhaust pipe 5 of the turbine 7a is rotationally driven.
The compressor 7b integrated by the shaft 13 and disposed within the intake pipe 4 is rotated, thereby compressing the intake air in the intake pipe 4 and delivering high-density intake air to each cylinder 2 of the internal combustion engine main body 3. (This action is called supercharging, and the compression force of the intake air by the compressor 7b is called supercharging pressure).

As a result, the charging efficiency in the internal combustion engine 1 is increased and a high output is achieved.

On the other hand, when the throttle 6 is wide opened and the rotational speed Ne of the internal combustion engine 1 increases, the exhaust flow rate also increases, and accordingly, the rotations of the turbine 7a and compressor 7b in the exhaust turbine supercharger 7 also increase, and the supercharging pressure increases. is enhanced.

When this supercharging pressure exceeds the set value, the positive pressure chamber 10a of the actuator IO, which is communicated with the intake pipe 4,
The pressure inside can overcome the pressure in the negative pressure chamber tab that is communicated with the atmosphere and the elastic force of a set spring (not shown) provided in this negative pressure chamber 10b, and the actuator l
The diaphragm 11 of O is moved and the wastegate valve 9 is opened by this diaphragm 11.

As a result, the exhaust gas in the exhaust pipe S bypasses the turbine 7a and is sent to the downstream side of the turbine 7a, and as a result, the rotation of the turbine 7a and compressor 7b is suppressed, and an increase in supercharging pressure is suppressed. Ru.

[Problems to be Solved by the Invention] By the way, in the internal combustion engine 1 of the conventional configuration described above,
The following problems occur.

In other words, when the throttle 6 is quickly returned from a high-speed, high-load operating state of the internal combustion engine 1, or when the throttle 6 is suddenly opened and closed, the intake pipe 4 is blocked by the throttle 6 and the intake air flow rate is significantly reduced. Despite the restrictions, the compressor 7b of the exhaust turbine supercharger 7 tries to continue rotating due to its inertia, but as a result,
As shown by the chain line in FIG. 4, the compressor 7b is operated in the surging generation region immediately after the throttle 6 is closed, and at the same time, abnormal noise is generated due to the surging.

Especially in internal combustion engines installed in vehicles, it is desired to eliminate such abnormal noises and surge noises as much as possible, since they cause discomfort to drivers and passengers.

On the other hand, as a way to deal with such problems, the following ■~
■Measures are being considered.

(2) A silencer is installed at the suction part of the compressor 7b of the exhaust turbine supercharger 7.

(2) A relief valve is installed between the discharge part of the compressor 7b of the exhaust turbine supercharger 7 and the throttle 6.

■Smaller capacity compressor 7 with larger surge margin
Use b.

However, according to the method (2) above, when the surge sound has a low frequency, the capacity of the muffler becomes large and it is difficult to apply it to an actual machine, and according to the method (2), the set pressure of the relief valve is constant. As a result, it is not possible to eliminate all the surge noise that occurs under various operating conditions, and furthermore,
According to the method (2), it is possible to reduce the surge noise, but each of them causes problems such as a decrease in the output in the high rotation range of the internal combustion engine, and cannot be an effective method.

The present invention aims to solve the problems remaining in the conventional techniques.

[Means for Solving the Problems] The present invention provides a method and device for controlling an internal combustion engine with an exhaust turbine supercharger that can effectively solve the above-mentioned problems. The control method is
In particular, an exhaust turbine supercharger, a waste gate valve that is attached to the exhaust turbine supercharger and allows υF air to bypass the exhaust turbine supercharger, and a supercharging pressure of the exhaust turbine supercharger that is set to a set value. 1. A control method for an internal combustion engine, comprising: an actuator that receives this supercharging pressure and operates a wastegate valve (l'i'i'i) when the above boost pressure is reached, The second aspect is characterized in that when negative pressure is generated, this negative pressure is applied to the actuator to reduce back pressure relative to the boost pressure, thereby speeding up the actuation start point of the actuator. A control device for an internal combustion engine includes an exhaust turbine supercharger, a waste gate valve that is attached to the exhaust turbine supercharger and causes exhaust gas to bypass the exhaust turbine supercharger, and a waste gate valve that allows exhaust gas to bypass the exhaust turbine supercharger; An actuator that receives this supercharging pressure and operates the waste gate valve when the pressure reaches a set value, and a positive pressure chamber that receives the supercharging pressure of this actuator are installed on the upstream side of the internal combustion engine's throttle and torque. a first communication pipe that communicates with the first communication pipe, a check valve provided in the middle of the first communication pipe that allows only the flow of gas from the discharge portion toward the positive pressure chamber, and a check valve that bypasses the check valve. a throttle member that communicates the upstream side of the throttle with a positive pressure chamber; a second communication pipe that communicates a negative pressure chamber attached to the positive pressure chamber with the downstream side of the throttle; and the second communication pipe. A check valve is provided between the negative pressure chamber and allows gas to flow only from the negative pressure chamber toward the downstream side of the throttle, and a check valve is provided between the check valve and the negative pressure chamber to allow the negative pressure chamber to pass through the The invention is characterized by comprising a diaphragm member that communicates with the.

[Operation] According to the first aspect of the present invention, the negative pressure downstream of the throttle when the throttle is closed is used to advance the actuator's operation start point, thereby opening the wastegate valve and preventing sudden throttle closure. The rotation of the exhaust turbine supercharger due to inertia is decelerated at an early stage, thereby preventing the exhaust turbine supercharger from operating in a surging region.

According to the second aspect, in a normal supercharging state, the double check valves act to apply supercharging pressure to the positive pressure chamber of the actuator and communicate the negative pressure chamber of the actuator to the atmosphere. This maintains the supercharging effect.

Furthermore, when the maximum boost pressure is reached, the actuator is actuated by the boost pressure to open the wastegate valve, and the boost pressure is maintained constant.

When a condition that can enter the surging region occurs, such as when the throttle is suddenly closed, the negative pressure on the downstream side of the throttle is guided to the negative pressure chamber of the actuator through the second communication pipe to provide supercharging in the actuator. The back pressure against the pressure is reduced and the wastegate valve is opened to quickly decelerate the rotation due to inertia of the exhaust turbine supercharger.

Thereby, the control method is reliably implemented and surging is efficiently suppressed.

Examples] Hereinafter, the present invention will be explained based on FIGS. 1 and 2.

First, prior to explaining a method for controlling an exhaust turbine supercharged internal combustion engine according to a first aspect of the present invention, an embodiment of a control device according to a second aspect of the present invention will be described.

In the following description, the same reference numerals are used for parts common to those in FIG. 3 to simplify the description.

The original number 20 in FIG. 1 is an internal combustion engine with an exhaust turbine supercharger (hereinafter simply referred to as internal combustion engine) to which this embodiment is applied.
This internal combustion engine 20 has a plurality of cylinders 2 (2a to 2
d), an intake pipe 4, an exhaust pipe 5, a throttle 6, an exhaust turbine supercharger 7, a bypass pipe 8, a wastegate valve 9, an actuator IO, a diaphragm 111, and a link mechanism 12.

In addition, the exhaust turbine supercharger (hereinafter simply referred to as supercharger) 7 includes a turbine 7a, a compressor 7b, and a /yaft 13 that connects these, as shown in the conventional art.
It is equipped with

and between the positive pressure chamber 10a of the actuator 10 and the supercharger 7 of the intake pipe 4 and the throttle 6, and between the negative pressure chamber 10b of the actuator 10 and the downstream side of the throttle 6 of the intake pipe 4. , the rr sign part of this embodiment is provided.

Next, to explain these in detail, a first communication pipe 21 is attached to the positive pressure chamber 10a of the actuator 10, and this first communication pipe 21 connects the supercharger 7 and the throttle 6. It is communicated with the intake pipe 4 at this point.

In the middle of this first communication pipe 21, there is a reverse IF valve 22 that allows only the flow of gas from the intake pipe 4 to the positive pressure chamber IQa.
A bypass pipe 23 is provided which communicates the upstream side and the downstream side of the check valve 22, and a J-width wire 24 is provided on the bypass pipe 23 as a restricting member.

Further, a second communication pipe 25 is attached to the negative pressure chamber 10b of the actuator 10, and this second communication pipe 2
5, the intake pipe 4 is connected downstream of the throttle 6.
It is communicated to.

A check valve 26 is provided in the middle of the second communication pipe 25 to allow only the flow of the substrate from the intake pipe 4 toward the negative pressure chamber tab. room 10
A breather pipe 27 that communicates the negative pressure chamber 10b with the atmosphere is provided between the check valve 26 and the check valve 26, and the breather pipe 27 is provided with an orifice 28 that is a restricting member.

The waste gate valve 9, the actuator 10, the link mechanism 12, the two-speed passage pipes 21 and 25, the two check valves 22 and 26, the bypass pipe 23, and the two orifices 24 and 28
, and the breather pipe 27 constitute the control device C of this embodiment.

Next, the control method according to the first aspect of the present invention will be explained along with the operation of the control device C configured as described above.

In a state where the operating state of the internal combustion engine 20 changes gradually over time, the same operation as the conventional one is performed.

That is, as the output of the internal combustion engine 20 increases, the exhaust gas rotates the turbine 7a of the supercharger 7, and the compressor 7b is rotated via the shaft 13, so that the intake air is compressed by the compressor 7b. and is supplied to each cylinder 2 of the internal combustion engine 20.

In the above-mentioned operating state, the compressor 7b
The discharge pressure, that is, the supercharging pressure, acts on the diaphragm 11 from the positive pressure chamber 10a side of the actuator 1o via the check valve 22, and at this point, the throttle 6 is opened and the downstream side of the throttle 6 is is almost the same pressure as the supercharging pressure, and the check valve 26 prevents this pressure from being transmitted to the negative pressure chamber 10b, so that the pressure in the negative pressure chamber 10b is maintained at atmospheric pressure. .

Therefore, the above-mentioned supercharging operation is continued until the supercharging pressure reaches the maximum supercharging pressure set by the set spring provided in the actuator 10.

Furthermore, when the boost pressure reaches the maximum boost pressure, the diaphragm 11 of the actuator 10 is moved against the set spring and atmospheric pressure, and furthermore, the movement of the diaphragm 11 is caused by the link mechanism 12. is transmitted to the wastegate valve 9, and the bypass pipe 8 is opened.

As a result, the exhaust gas is passed through the bypass pipe 8 to the turbine 7a.
The rotation of the turbine 7a, that is, the rotation of the compressor 7b, is suppressed, and the boost pressure is maintained at the maximum boost pressure.

On the other hand, for example, if the throttle 6 is suddenly closed while the internal combustion engine 20 is operating at high speed, the balance between the deceleration effect of the flow of intake air in the intake pipe 4 and the rotational force due to the inertia of the compressor 7b Therefore, conditions may be met for the supercharger 7 to enter the surging region.

In this case, negative pressure is generated on the downstream side of the rapidly closed throttle 6, and this negative pressure is transmitted to the negative pressure chamber tab of the actuator 10 via the second communication pipe 25.

Since this negative pressure acts on the diaphragm 11 so as to cancel out the elastic force of the set spring and air particles acting on the diaphragm 11, the supercharging pressure and the elastic force of the set spring are reduced. The balance between air pressure and atmospheric pressure is disrupted, causing the diaphragm 11 to move.

When the diaphragm 11 is moved in this way,
By releasing the blockage of the bypass pipe 8 by the wastegate valve 9, the rotation of the turbine 7a, that is, the compressor 7b is suppressed, and the rotation thereof is quickly decelerated.

Therefore, the rotation of the supercharger 7 is decelerated before the supercharger 7 enters the surging region, thereby preventing the occurrence of surging and the generation of a surging sound. This phenomenon is shown by the chain line in Figure 2.

Furthermore, after the wastegate valve 9 is opened when the throttle 6 is suddenly closed as described above, the action of the orifices 24 and 28 causes the operation to occur after a certain period of time (this time is given by the orifices 24 and 28). (determined by the magnitude of the flow path resistance), the actuator 10
The positive pressure chamber 10a is equal to the reduced supercharging pressure of the intake pipe 4,
Further, the negative pressure chamber Job is made equal to the atmospheric pressure, and the normal supercharging operation state is restored.

It should be noted that the shapes and dimensions of each component shown in the above embodiments are merely examples, and can be variously changed based on the type and type of internal combustion engine to be applied, design requirements, etc.

For example, in the embodiment described above, the orifices 24 and 28 are shown as the throttle members, but a porous body, a variable throttle valve, a fiber, or the like may be used instead.

[Effects of the Invention] As explained above, the method for controlling an internal combustion engine with an exhaust turbine supercharger according to the first aspect of the present invention includes an exhaust turbine supercharger and an internal combustion engine installed alongside the exhaust turbine supercharger. , a waste gate valve that causes exhaust gas to bypass the exhaust turbine supercharger; and when the supercharging pressure of the exhaust turbine supercharger reaches a set value or more, the waste gate valve is actuated in response to this supercharging pressure. A control method for an internal combustion engine, comprising: an actuator for controlling a throttle of an internal combustion engine;
When negative pressure is generated on the side, this negative pressure is applied to the actuator to reduce the back pressure relative to the boost pressure, thereby speeding up the actuation start point of the actuator, and the following: It has excellent effects such as:

By using the negative pressure downstream of the throttle when the throttle is closed to advance the activation point of the actuator, the wastegate valve opens earlier, thereby reducing the rotation due to inertia of the exhaust turbine supercharger when the throttle is closed. By reducing the pressure at an early stage, it is possible to prevent the exhaust turbine supercharger from operating in a surging generation region and to prevent the generation of surge noise.

Further, the control device for an internal combustion engine according to a second aspect includes an exhaust turbine supercharger, a waste gate valve that is attached to the exhaust turbine supercharger and causes exhaust gas to bypass the exhaust turbine supercharger, and When the boost pressure of the exhaust turbine supercharger reaches a set value or higher, an actuator that receives this boost pressure to operate the wastegate valve and a positive pressure chamber that receives the boost pressure of this actuator are activated by internal combustion. a first communication pipe that communicates with the upstream side of the throttle of the engine; a check valve provided in the middle of the first communication pipe that allows only the flow of gas from the discharge portion toward the positive pressure chamber; a throttle member that communicates the upstream side of the throttle with the positive pressure chamber by bypassing the stop valve; a second communication pipe that communicates the negative pressure chamber attached to the positive pressure chamber with the downstream side of the throttle; A slot is provided in the middle of this second communication passage from the negative pressure chamber.

A check valve that only allows gas to flow toward the downstream side of the engine, and a throttle member that is provided between the check valve and the negative pressure chamber and communicates the negative pressure chamber with the atmosphere. It is characterized by the following excellent effects.

In addition to normal supercharging and suppressing the increase in supercharging pressure when the maximum supercharging pressure is reached, it is also effective in suppressing the increase in supercharging pressure when it reaches the maximum supercharging pressure. , the negative pressure on the downstream side of the throttle is guided to the negative pressure chamber of the actuator through a second communication pipe to reduce the back pressure of the supercharging pressure in the actuator, and the actuator is activated, that is, the waste gate valve is opened early to exhaust air. The rotation due to inertia of the turbine supercharger can be reduced.

Therefore, the control method described above can be carried out reliably, and the occurrence of surging and surge noise can be efficiently suppressed.

[Brief explanation of drawings]

1 and 2 show an embodiment of the second aspect of the present invention, in which FIG. 1 is a schematic diagram showing the entire device, and FIG. 2 is a mount for explaining the operation. Figures 3 and 4 are diagrams showing the relationship between discharge pressure and exhaust flow rate, and show a conventional example. Figure 3 is a schematic diagram showing the overall device, and Figure 4 is a diagram for explaining the operation. FIG. 3 is a diagram showing the relationship between compressor discharge pressure and exhaust flow rate. Fig. 2 6... Throttle, 7... (Exhaust turbine) Supercharger, 7a... Turbine, 7b... Compressor, 8
...Bypass pipe, 9..Wastegate valve,
10... Actuator, 10a... Positive pressure chamber, 10b... Negative pressure chamber, 20...
・Internal combustion engine (with exhaust turbine supercharger), 21...first communication pipe, 22...check valve, 23...bypass 1g, 2
4... Orifice, 25... Second communication pipe, 26.
...Check valve, 28...Orifice, C...Control device. Figure 4

Claims (2)

[Claims] (1) An exhaust turbine supercharger, a waste gate valve that is attached to the exhaust turbine supercharger and allows exhaust gas to bypass the exhaust turbine supercharger, and a supercharging pressure of the exhaust turbine supercharger that is set to a set value. an actuator that operates the wastegate valve in response to the supercharging pressure when the above-mentioned boost pressure is reached; A method for controlling an internal combustion engine with an exhaust turbine supercharger, characterized in that the negative pressure is applied to the actuator to reduce back pressure with respect to the supercharging pressure, thereby accelerating the start point of operation of the actuator. (2) an exhaust turbine supercharger; a waste gate valve that is installed alongside the exhaust turbine supercharger to allow exhaust gas to bypass the exhaust turbine supercharger; and a set value for the supercharging pressure of the exhaust turbine supercharger. When the above-mentioned pressure is reached, an actuator that receives this boost pressure operates the waste gate valve, and a first actuator that communicates the positive pressure chamber that receives the boost pressure of this actuator with the upstream side of the throttle of the internal combustion engine. a communication pipe, a check valve provided in the middle of the first communication pipe and allowing only the flow of gas from the discharge portion toward the positive pressure chamber, and a check valve that bypasses the check valve and connects the gas to the upstream side of the throttle. a throttle member that communicates with the positive pressure chamber; a second communication pipe that communicates the negative pressure chamber attached to the positive pressure chamber to the downstream side of the throttle; and a second communication pipe provided in the middle of the second communication pipe, a check valve that only allows gas to flow from the negative pressure chamber toward the downstream side of the throttle; and a throttle member that is provided between the check valve and the negative pressure chamber and communicates the negative pressure chamber with the atmosphere. A control device for an internal combustion engine with an exhaust turbine supercharger, comprising: