JP2528694Y2 - Exhaust gas mixing device for turbocharged engines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application field] The present invention relates to an exhaust gas mixing device for a supercharged engine.

[Prior Art] An engine with a supercharger is as shown in FIG.

That is, the air cleaner a, the compressor c of the supercharger b,
The intercooler d is connected to the intake side of an engine f such as a diesel engine via an intake line e.

The turbine g of the supercharger b is connected to the exhaust side of the engine f via the exhaust line h, and the supercharger b in the exhaust line h
A bypass line i is provided between the suction side and the discharge side of the turbine g, and the bypass line i is connected to the bypass line i when the supercharging pressure of the intake air by the compressor c of the supercharger b exceeds a set value. An open waste gate valve j is provided.

The intake air is supercharged by an air cleaner a, supercharged by a compressor c of a supercharger b, cooled by an intercooler d, and then enters the intake side of the engine f and burns together with fuel oil.

The exhaust gas generated in the engine f by the combustion drives the compressor c from the exhaust side of the engine f through the turbine g of the supercharger b, and then is discharged from the exhaust line h to the atmosphere.

When the supercharging pressure of the intake air by the compressor c of the supercharger b exceeds a set value, the waste gate valve j operates to open the bypass line i, and a part of the exhaust gas is released to the bypass line i. As a result, the amount of exhaust gas passing through the turbine g decreases, the driving force of the supercharger b for the compressor c decreases, and the supercharging pressure of the intake air decreases.

On the other hand, in engines other than the turbocharged engine, part of the exhaust gas discharged from the exhaust line of the engine is returned to the intake line of the engine by utilizing a pressure difference between the exhaust line and the intake line. The so-called exhaust gas mixing is performed in which the combustion of fuel oil in the engine is suppressed by the exhaust gas returned to the engine and the combustion temperature is reduced to reduce the generation of NOx.

[Problem to be Solved by the Invention] However, when the engine is equipped with a supercharger, there is a problem as described below when attempting to mix exhaust gas.

That is, when a part of the exhaust gas is returned to the compressor c discharge side of the supercharger b in the suction line e of FIG.
Since the supercharging pressure acts on the intake air on the discharge side of the supercharger b, the pressure difference between the supercharger b and the exhaust line h becomes small, and a sufficient amount of exhaust gas can be returned to the intake line e. Absent.

The compressor c of the supercharger b in the suction line e
If a part of the exhaust gas is returned to the suction side, the temperature of the intake air and further the temperature of the supercharger b are increased by the returned exhaust gas, so that the durability of the suction line e is significantly reduced.

Therefore, in the turbocharged engine, exhaust gas mixing using the pressure difference between the exhaust line h and the suction line e cannot be performed.

The present invention has been made in view of the above-described circumstances, and also enables a supercharged engine to perform exhaust gas mixing using a pressure difference between an exhaust line and an intake line. It is an object of the present invention to provide an exhaust gas mixing device.

Means for Solving the Problems According to the present invention, a compressor of a supercharger is disposed in an intake line of an engine, and a turbine of a supercharger is disposed in an exhaust line of the engine. A bypass line with a waste gate valve is provided between the exhaust line and an exhaust throttle valve is provided downstream of the connection of the bypass line in the exhaust line in the exhaust gas flow direction. An exhaust gas mixing line with an exhaust gas mixing valve is connected from an intermediate position with the installation part to an intermediate position between the engine and the compressor in the intake line, and the opening can be adjusted in multiple stages with an exhaust throttle valve and exhaust gas mixing valve Exhaust gas mixing device for turbocharged engines, characterized by the connection of various multi-stage cylinders Things.

[Operation] The intake air passing through the intake line is applied with a supercharging pressure by the compressor of the supercharger on the way, is taken into the engine, and is burned together with the fuel oil inside the engine.

Exhaust gas generated by combustion in the engine passes through an exhaust line, passes through a turbine of a supercharger, drives a compressor, and is then discharged.

Here, when the waste gate valve of the bypass line is opened, a part of the exhaust gas in the exhaust line bypasses the turbine of the turbocharger and flows through the bypass line.
The amount of exhaust gas passing through the turbine of the supercharger decreases, and as a result, the driving force of the supercharger to the compressor decreases, and the supercharging pressure of the intake air in the suction line decreases.

In addition, when the exhaust line is throttled by the exhaust throttle valve, the pressure of the exhaust gas in the exhaust line on the upstream side in the exhaust gas flow direction from the exhaust throttle valve increases, and the pressure difference between the exhaust line and the suction line increases. .

Therefore, when the exhaust gas mixing valve of the exhaust gas mixing line is opened, due to the pressure difference between the exhaust line and the suction line,
The exhaust gas from the exhaust line is returned to the intake line via the exhaust gas mixing line, and the exhaust gas is mixed.

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

 1 to 4 show an embodiment of the present invention.

The air cleaner 1, the compressor 3 of the supercharger 2, and the intercooler 4 are connected to the intake side of an engine 9 such as a diesel engine via intake lines 5 to 8.

The turbine 10 and the exhaust throttle valve 11 of the supercharger 2 are connected to the exhaust side of the engine 9 via exhaust lines 12 to 14.

The exhaust throttle valve 11 has a configuration as shown in FIG.

A cylindrical second piston 16 having one end opened and a stopper 29 at an opening is slidably provided inside the casing 15, and a first piston 17 is slidably provided inside the second piston 16. A multistage type having air chambers 21, 22, and 23 between the first piston 17 and the second piston 16, on the side of the second piston 16 opposite the first piston 17, and on the side of the first piston 17 opposite the second piston 16 respectively. Is formed.

The first piston 17 of the cylinder 24 is connected to the rear end of a rod 25 that extends toward the second piston 16 and has a distal end that penetrates the casing 15, and the casing 15 of the air chamber 23 and the first piston
A spring 26 for urging the first piston 17 toward the second piston 16 is interposed between the second piston 16 and the first piston 17 on the surface of the other end opening of the second piston 16 on the air chamber 21 side. Pressing protrusion
Form 31.

The air chambers 21, 22, 23 of the cylinder 24 and the casing
15 Form ports 18, 19, and 20 that communicate with the outside.

Reference numeral 30 denotes a port 18 provided in the second piston 16 and the air chamber 21.
This is an air flow path that communicates with.

A butterfly valve 28 is rotatably provided at a position between the exhaust lines 13 and 14, the tip of the rod 25 of the cylinder 24 is connected to the butterfly valve 28 via a lever 27, and the butterfly valve 28 can be opened and closed by the cylinder 24. To

Turbine 1 of turbocharger 2 between exhaust lines 12 and 13 in FIG.
A bypass line 32 bypassing 0 is provided, and a waste gate valve 33 is provided in the bypass line 32.

The waste gate valve 33 is, as shown in FIG.
A supercharging pressure control actuator 38 in which the diaphragm 36 is pressed against a spring 35 by supplying air to the port 34, and a bypass line 32 provided integrally with the diaphragm 36 of the supercharging pressure control actuator 38 And a valve element 37 that opens and closes the inlet portion.

An exhaust gas mixing line 39 is connected from an exhaust line 13 between the turbine 10 and the exhaust throttle valve 11 of the supercharger 2 to an intake line 8 between the intercooler 4 and the engine 9 in FIG. An exhaust gas mixing valve 40 is provided in the mixing line 39.

The exhaust gas mixing valve 40 has a configuration as shown in FIG.

Inside the casing 41, a cylindrical second piston 42 having one end opened and having a stopper 55 at the opening is slidably provided, and the first piston 43 is slidably provided inside the second piston 42. Between the first piston 43 and the second piston 42,
The second piston 42 is opposite to the first piston 43, the first piston 43
A multi-stage cylinder 50 having air chambers 47, 48, 49 on the side opposite to the second piston 42 is formed. The cylinder 50 extends from the first piston 43 to the side opposite to the second piston 42, and the tip is a casing.
A rear end of a rod 51 that penetrates the first piston 43 is connected between the casing 41 of the air chamber 49 and the first piston 43.
A spring 52 for urging the second piston 42 toward
In addition, a projection 57 that pushes the first piston 43 is formed on a surface of the other end opening of the second piston 42 on the air chamber 47 side.

Also, the air chambers 47, 48, 49 of the cylinder 50 and the casing
41 Ports 44, 45, and 46 communicating with the outside are formed.

Reference numeral 56 denotes a port 44 provided in the second piston 42 and an air chamber 47.
This is an air flow path that communicates with.

A valve body that contacts the valve seat 53 formed in the exhaust gas mixing line 39
54 is provided, and the tip of the rod 51 of the cylinder 50 is connected to the valve element 54 so that the valve element 54 can be moved toward and away from the valve seat 53 by the cylinder 50.

Exhaust throttle valve 11 and waste gate valve in FIG.
33, air pipes 58 to 62 for supplying high-pressure air from an air tank (not shown) are connected to the ports 18, 19, 34, 44, and 45 of the exhaust gas mixing valve 40, respectively. Solenoid valves 63 to 67 are provided.

Also, ports for the exhaust throttle valve 11 and the exhaust gas mixing valve 40
20,46 are open to the atmosphere.

A control device 74 is provided for inputting a signal 68 indicating the number of revolutions and load from the engine 9 to obtain a mixing amount of exhaust gas, and sending a switching command 69 to 73 to each of the solenoid valves 63 to 67 based on the mixing amount of the exhaust gas. .

 Next, the operation will be described.

The intake air coming from the suction line 5 is filtered by the air cleaner 1, passes through the suction line 6, is supercharged by the compressor 3 of the supercharger 2, and then passes through the suction line 7 to the intercooler 4. The fuel is cooled, enters the intake side of the engine 9 through the intake line 8, and is burned together with the fuel oil.

Exhaust gas generated in the engine 9 by the combustion drives the compressor 3 from the exhaust side of the engine 9 through the turbine 10 of the supercharger 2 via the exhaust line 12, and the exhaust lines 13,1
Emitted to the atmosphere through 4.

At this time, the control device 74 inputs a signal 68 such as the number of revolutions and load of the engine 9 and is preset in the control device 74.
From the function indicating the relationship between the signal 68 and the exhaust gas mixing amount, an exhaust gas mixing amount is obtained, and each solenoid valve is determined based on the exhaust gas mixing amount.
Switching commands 69 to 73 are sent to 63 to 67, respectively.

Then, first, the solenoid valve 65 is switched by the switching command 71, and air is discharged through the air pipe 60 to the waste gate valve.
33, and the air pushes the diaphragm 36 of the waste gate valve 33, and the diaphragm 36
The valve body 37 integrally mounted on the
Open 32.

Then, the exhaust line 12 on the suction side of the turbine 10 of the supercharger 2
A part of the exhaust gas flowing through the turbocharger 2 is bypassed to the exhaust line 13 on the discharge side of the turbine 10 of the supercharger 2 through the bypass line 32, and the amount of the exhaust gas passing through the turbine 10 of the supercharger 2 is reduced. The driving force of the compressor 2 for the compressor 3 decreases, and the supercharging pressure of the intake air in the suction lines 7 and 8 decreases.

At the same time, the solenoid valve 63 or 64 is switched by the switching command 69 or 70.
Is switched, and air is sent to the port 18 or 19 of the exhaust throttle valve 11 and the air chambers 21 and 22 via the air pipe 58 or 59, and the first piston 17 or the second piston 16 is
Is pushed, and the butterfly valve 28 passes through the rod 25 and the lever 27.
Rotates to narrow the space between the exhaust lines 13 and 14.

Then, since the flow resistance from the exhaust lines 13 to 14 increases, the pressure of the exhaust gas in the exhaust line 13 increases, and the pressure difference between the exhaust line 13 and the suction line 8 increases.

Here, when reducing the exhaust gas mixing amount, the control device
74 sends a switching command 69 to the solenoid valve 63 to send the air in the air pipe 58 to the port 18 and the air chamber 21 of the exhaust throttle valve 11 to move the first piston 17.

Then, the first piston 17 is the stopper of the second piston 16
Because it can only move to the position stopped by 29,
The rod 25 moves slightly, the amount of rotation of the butterfly valve 28 connected to the rod 25 via the lever 27 also becomes small, and the amount of restriction between the exhaust lines 13 and 14 is reduced.

Conversely, when increasing the exhaust gas mixture,
74 sends a switching command 70 to the solenoid valve 64 to send the air in the air pipe 59 to the port 19 and the air chamber 22 of the exhaust throttle valve 11 to move the second piston 16.

Then, the second piston 16 largely moves the rod 25 with the first piston 17 by the projection 31, the rotation amount of the butterfly valve 28 connected to the rod 25 via the lever 27 also increases, and the second piston 16 moves between the exhaust lines 13 and 14. The aperture amount increases.

Furthermore, when increasing the exhaust gas mixing amount, the control device 74 sends switching commands 69 and 70 to the solenoid valves 63 and 64 at the same time,
Exhaust air from the air pipes 58 and 59 to the ports 18 and 19 of the exhaust throttle valve 11.
And the air is sent to the air chambers 21 and 22 so that the first and second pistons 16 and 17 are simultaneously moved.

Then, since the position of the stopper 29 of the second piston 16 moves, the first piston 17 can move the rod 25 more greatly, and the amount of rotation of the butterfly valve 28 connected to the rod 25 via the lever 27 also increases. Exhaust line
The aperture between 13 and 14 becomes larger.

Thus, the exhaust line is controlled by the three-stage cylinder 24.
The aperture between 13 and 14 is adjusted in three stages.

When the pressure difference between the exhaust line 13 and the suction line 8 is increased, the solenoid valve 66 or 67 is switched by the switching command 72 or 73.
Is switched, and the air is sent to the port 44 or 45 of the exhaust gas mixing valve 40 and the air chambers 47 and 48 via the air pipe 61 or 62, and the first piston 43 or the second piston
42 is pushed, the valve element 54 is separated from the valve seat 53 via the rod 51, and the exhaust gas mixing line 39 is opened.

As a result, a part of the exhaust gas of the exhaust line 13 is returned to the intake line 8 via the exhaust gas mixing line 39 due to the pressure difference between the exhaust line 13 and the intake line 8, thereby controlling the combustion of the engine 9. Low NOx is achieved.

Here, when reducing the exhaust gas mixing amount, the control device
74 sends a switching command 72 to the solenoid valve 66 to send the air in the air pipe 61 to the port 44 and the air chamber 47 of the exhaust gas mixing valve 40 to move the first piston 43.

Then, the first piston 43 is a stopper of the second piston 42
Because it can only move to the position stopped by 55,
The rod 51 moves slightly, the amount of movement of the valve body 54 relative to the valve seat 53 becomes small, and the opening degree of the exhaust gas mixing line 39 is suppressed to a small value.

Conversely, when increasing the exhaust gas mixture,
74 sends a switching command 73 to the solenoid valve 67 to send the air in the air pipe 62 to the port 45 and the air chamber 48 of the exhaust gas mixing valve 40 to move the second piston 42.

Then, the second piston 42 largely moves the rod 51 with the first piston 43 by the projection 57, the movement amount of the valve body 54 with respect to the valve seat 53 becomes large, and the opening degree of the exhaust gas mixing line 39 becomes large.

In order to further increase the exhaust gas mixing amount, the control device 74 sends a switching command 73 to the solenoid valves 66 and 67 at the same time, and the air in the air pipes 61 and 62 is supplied to the ports 44 and 45 of the exhaust gas mixing valve 40 and the air. The first and second pistons 42 and 43 are moved to the chambers 47 and 48 so as to be moved simultaneously.

Then, the position of the stopper 55 of the second piston 42 moves, so that the first piston 43 can move the rod 51 further, and the movement amount of the valve body 54 with respect to the valve seat 53 further increases, and the exhaust gas mixing line 39 Is larger.

In this way, the opening degree of the exhaust gas mixing line 39 is adjusted in three stages by the three-stage cylinder 50.

The waste gate valve 33 is separately operated to limit the supercharging pressure, which is the original purpose, in addition to the exhaust gas mixing.

Here, since exhaust gas mixing is not usually performed at the time of idling or high load, the operation of the waste gate valve 33 at the time of intermediate load is mainly for exhaust gas mixing, and the waste gate valve at the time of high load. The operation of 33 is mainly due to the limitation of the supercharging pressure.

Further, even when the waste gate valve 33 is opened with the exhaust throttle valve 11 being throttled to increase the pressure in the exhaust lines 12 and 13, the pressure in the bypass line 32 is higher than that in the turbine 10 at an intermediate load. Since the relationship that the loss is reduced is maintained, the function of reducing the supercharging pressure is sufficiently performed.

The exhaust gas mixing device of the turbocharged engine of the present invention
The present invention is not limited to the above-described embodiment, but can be applied to a turbocharged engine in general, and it is needless to say that various changes can be made without departing from the gist of the present invention.

[Effects of the Invention] As described above, according to the exhaust gas mixing device of the turbocharged engine of the present invention, the waste gate valve, the exhaust throttle valve, the exhaust gas mixing valve, and the like actively intervene between the exhaust line and the intake line. The exhaust gas can be mixed even with a supercharged engine, and the multi-stage cylinder is connected to the exhaust throttle valve and exhaust gas mixing valve to increase the opening degree in multiple stages. It is possible to achieve an excellent effect that adjustment can be performed and high controllability can be obtained.

[Brief description of the drawings]

FIG. 1 is a system diagram of one embodiment of the present invention, FIG. 2 is a detailed view of an exhaust throttle valve of FIG. 1, FIG. 3 is a detailed view of a waste gate valve of FIG. 1, and FIG. FIG. 5 is a detailed view of the exhaust gas mixing valve shown in the figure, and FIG. 5 is a system diagram of a conventional supercharged engine. In the figure, 2 is a supercharger, 3 is a compressor of the supercharger 2, 5, 6, 7, and
8 is an intake line, 9 is an engine, 10 is a turbine of the turbocharger 2, 11 is an exhaust throttle valve, 12, 13, 14 are exhaust lines, 32 is a bypass line, 33 is a waste gate valve, 39 is an exhaust gas mixing line, Reference numeral 40 denotes an exhaust gas mixing valve.

Claims (1)

(57) [Scope of request for utility model registration] 1. A turbocharger compressor is disposed in an intake line of an engine, and a turbocharger turbine is disposed in an exhaust line of the engine. A waste gate valve is provided between a suction side and a discharge side of the turbine in the exhaust line. The exhaust line is provided with an exhaust throttle valve downstream of the connection of the bypass line in the exhaust line in the exhaust gas flow direction, from an intermediate position between the connection of the bypass line in the exhaust line and the installation portion of the exhaust throttle valve. Connecting an exhaust gas mixing line with an exhaust gas mixing valve to an intermediate position between the engine and the compressor in the suction line,
Furthermore, an exhaust gas mixing device for a supercharged engine, wherein a multistage cylinder whose opening degree can be adjusted in multiple stages is connected to the exhaust throttle valve and the exhaust gas mixing valve.