JPH0310345Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an engine equipped with two sets of exhaust superchargers (turbochargers).

[Conventional technology]

The energy of the exhaust gas, which was conventionally wasted into the atmosphere, is recovered by converting it into the rotational force of a turbine installed in the engine's exhaust passage, and the compressor installed in the coaxial intake system increases the filling efficiency of the air-fuel mixture. Engines equipped with exhaust gas superchargers are often used to improve output and fuel efficiency.

Incidentally, an engine has been developed that is equipped with two sets of superchargers, in which the supercharging pressure can be changed when the engine is rotating at low speeds and when the engine is rotating at high speeds, thereby improving combustion in each case.

In conventional engines with this type of exhaust supercharger,
As shown in FIG. 4, a turbine 6a is installed in the exhaust passage 11 of the intake and exhaust system of the engine 1, and a compressor 6b is installed in the intake passage 7 of the intake and exhaust system to be driven by the turbine 6a. A main exhaust supercharger (turbocharger) 6 is provided.

The overpressurized intake air from the compressor 6b is sent to the intake port 3 leading to the combustion chamber 2 of each cylinder through the intake manifold 5.
The combustion chamber 2 of each cylinder opens and closes as the intake valve opens and closes.
sent inward.

Exhaust gas discharged from the exhaust port 4 of the combustion chamber 2 of each cylinder is sent to an exhaust manifold 10 forming an exhaust passage of an intake/exhaust system, and is supplied from the exhaust manifold 10 via an exhaust passage 11 to the turbine 6a.

In addition, the intake and exhaust system of the engine 1 includes an exhaust passage 1.
2 and the turbine 8a installed in the turbine 8.
A sub-exhaust supercharger (turbocharger) 8 is provided, which is driven by a compressor 8b and a compressor 8b interposed in an intake passage 9 of the intake and exhaust system.

The overpressurized charge air from the compressor 8b is transferred to the intake air in the combustion chamber 2 of each cylinder through the charge air switching valve 19 as a supercharge throttle valve installed in the intake passage 9 and the intake manifold 5. The air is sent to the port 3 and into the combustion chamber 2 of each cylinder as the intake valve at the intake port 3 opens and closes.

Exhaust gas discharged from the exhaust port 4 of the combustion chamber 2 of each cylinder is sent to the exhaust manifold 10, and from the exhaust manifold 10 is passed to the turbine 8a through an exhaust passage 12 in which an exhaust switching valve 18 as an exhaust throttle valve is interposed. supplied to

Note that intake passages 13 and 14 are connected to each exhaust supercharger 6 and 8, respectively, and exhaust passages 15 and
Connect 16. Ends of each exhaust passage 15 and 16 communicate with an exhaust port 17.

In addition, an exhaust switching valve 1 is provided in the middle of the exhaust passage 12.
8. A supercharging air switching valve 19 is provided in the middle of the intake passage 9 so as to be openable and closable.

A relief valve 20 branches into the intake passage 9 between the supercharging air switching valve 19 and the sub-exhaust supercharger 8, and the branched intake air is released to the atmosphere through a relief port 21.

The exhaust switching valve 18 is opened and closed by air pressure from an operating air passage 22 branching from a portion of the intake passage 9 near the engine 1.

The supercharging air switching valve 19 and the relief valve 20 are operated by an air link mechanism 24 that is operated by the air pressure of a communication passage 23 that branches from the middle part of the operating air passage 22.
They are connected in such a way that they tend to open and close in opposite directions.

In a conventional engine with an exhaust supercharger, only the main exhaust supercharger 6 is operated when the engine 1 is rotating at a low speed.

In other words, since the exhaust pressure is weak, the exhaust switching valve 18
Once the spring force of
Close 2. At the same time, the air link mechanism 24 closes the supercharging air switching valve 19 and opens the relief valve 20.

As a result, the turbine 6a of the main supercharger 6 rotates in response to exhaust pressure, and the coaxial compressor 6b compresses the intake air.

Then, the intake air is supercharged from each intake port 3 to the combustion chamber 2 of each cylinder via the intake passage 7 and the intake manifold 5.

Since the exhaust switching valve 18 is closed, all exhaust gas discharged from the combustion chamber 2 of each cylinder via the exhaust manifold 10 is guided to the main exhaust supercharger 6. Furthermore, since the supercharging air switching valve 19 is closed, backflow of the charged air to the compressor 8b of the sub-exhaust supercharger 8 is prevented, and by opening the relief valve 20, the supercharging air is transferred to each cylinder. The supply to the combustion chamber 2 is completely stopped.

When the engine 1 rotates at high speed, the exhaust pressure overcomes the spring force of the exhaust switching valve 18 and the supply pressure of the operating air passage 22 increases, so that the exhaust switching valve 18 becomes open.

At the same time, the supercharging air switching valve 19 is in the open state and the relief valve 20 is in the closed state.

Therefore, the auxiliary exhaust supercharger 8 operates together with the main exhaust supercharger 6 to increase the supercharging pressure, thereby increasing the filling efficiency of the air-fuel mixture.

[Problem that the invention attempts to solve]

By the way, in this way, two sets of exhaust superchargers 6 and 8
In engine 1 equipped with this, the amount of air in the high-speed, high-load range is significantly increased, and combustion is significantly improved.
In the low speed and high load range, only a certain amount of increase in air volume can be expected.

In other words, the intake port 3 of the engine 1 is a so-called high swirl port (strong swirl intake hole), with a slight "twist" in the port passage.
A swirl of the air-fuel mixture is forcibly formed in the circumferential direction of the combustion chamber 2 during the intake stroke. This improves mixing efficiency. However, the swirl speed is constant regardless of the presence or absence of the exhaust supercharger, and the swirl ratio, which is the swirl speed relative to the engine rotation speed, does not change.

Therefore, even though two sets of exhaust superchargers 6 and 8 are provided, the swirl speed decreases in the low-speed, high-load operating range of the engine 1, so there is a problem that a significant improvement in combustion efficiency cannot be expected and the lining cost is high.

The present invention aims to solve these problems and provides an engine with an exhaust supercharger that improves the swirl ratio in the low speed and high load range and improves the combustion efficiency. The purpose is to

[Means for solving problems]

Therefore, the engine with an exhaust supercharger of the present invention has a turbine installed in the intake passage of the primary intake and exhaust system of the engine to be driven by the turbine installed in the exhaust passage of the primary intake and exhaust system of the engine. a main exhaust supercharger consisting of a compressor and a turbine installed in the exhaust passage of the secondary intake and exhaust system of the engine; a sub-exhaust turbocharger consisting of a compressor and a compressor, and an exhaust throttle installed in the exhaust passage of the secondary intake/exhaust system to control the flow rate of exhaust gas supplied to the turbine of the sub-exhaust turbocharger. and a supercharging air throttle valve that is interposed in the intake passage of the secondary intake/exhaust system and controls the flow rate of supercharging air sent out from the compressor of the sub-exhaust supercharger, and the exhaust throttle valve an actuator for the exhaust throttle valve that adjusts the opening of the above-mentioned supercharged air throttle valve; an actuator for the supercharged air throttle valve that adjusts the opening of the above-mentioned supercharged air throttle valve; a controller for supplying a control signal, a cooler is interposed in each of the intake passage of the primary intake and exhaust system and the intake passage of the secondary intake and exhaust system, and the intake passage of the primary intake and exhaust system is provided with a cooler. , a primary intake valve that operates over the entire operating range of the engine, a primary intake port for generating a swirl that generates a large swirl in the intake air sent to the combustion chamber of the engine, and a primary intake valve that operates over the entire operating range of the engine; The intake passage of the intake and exhaust system is equipped with a valve operation stop mechanism that operates in the low speed and high load operating range of the engine mentioned above.
It is characterized by being provided with a secondary intake valve and a swirl reduction secondary intake port that reduces the swirl of the intake air sent to the combustion chamber.

[Effect]

Since the exhaust supercharged engine of the present invention is configured as described above, in the low-speed, high-load operating range of the engine, control signals are supplied from the control device to the exhaust throttle valve actuator and the supercharging throttle valve actuator, respectively. The exhaust throttle valve and supercharging throttle valve are closed, air is supplied and exhausted only by the primary intake and exhaust system, and the air is sent to the combustion chamber through the cooler and the primary intake port for swirl generation. The filling efficiency of Qi is increased and a large swirl is generated.

In addition, in high-speed or low-load operating ranges of the engine, the exhaust throttle valve and the supercharging throttle valve are open, and air is supplied and exhausted by the primary intake and exhaust system and the secondary intake and exhaust system, and is passed through the cooler. The cooled charge air is sent to the combustion chamber through the primary intake port for generating swirl and the secondary intake port for reducing swirl, thereby increasing the charging efficiency and reducing the swirl.

〔Example〕

Hereinafter, an embodiment of the present invention will be explained with reference to the drawings. Figures 1 to 3 show an engine with an exhaust supercharger as an embodiment of the present invention, and Figure 1 is an overall configuration diagram thereof, All three figures are graphs for explaining the effect.

As shown in FIG. 1, the primary intake/exhaust system P of the engine 1 includes a turbine 6a installed in the exhaust passage 11 of the primary intake/exhaust system P, and a primary intake/exhaust system P to be driven by the turbine 6a. A main exhaust supercharger (turbocharger) 6 including a compressor 6b is provided in the intake passage 7 of the exhaust system P.

Then, the overpressurized supply air from the compressor 6b is transferred to the main intercooler 27 as a cooler,
The air is sent to the primary intake port 3a leading to the combustion chamber 2 of each cylinder through the main intake manifold 5a, and is sent into the combustion chamber 2 of each cylinder as the primary intake valve 28 in the primary intake port 3a opens and closes. .

Exhaust gas discharged from the primary exhaust port 4a and secondary exhaust port 4b of the combustion chamber 2 of each cylinder is sent to the exhaust manifold 10, which forms the exhaust passage of the primary intake/exhaust system P and the secondary intake/exhaust system S. Furthermore, it is supplied from the exhaust manifold 10 to the turbine 6a via the exhaust passage 11.

The secondary intake/exhaust system S of the engine 1 also includes a turbine 8a interposed in the exhaust passage 12 of the secondary intake/exhaust system S, and an intake air of the secondary intake/exhaust system S to be driven by the turbine 8a. A sub-exhaust supercharger (turbocharger) 8 consisting of a compressor 8b interposed in a passage 9 is provided.

The overpressurized supply air from the compressor 8b is passed through the supercharging air switching valve 19 as a supercharging throttle valve installed in the intake passage 9, the sub-intercooler 30 as a cooler, and the sub-supply air manifold 5b. , a secondary intake port 3 leading to the combustion chamber 2 of each cylinder
b, and is sent into the combustion chamber 2 of each cylinder as the secondary intake valve 29 with a conventionally known valve operation stop mechanism opens and closes in the secondary intake port 3b.

Further, the main intercooler 27 and the sub-intercooler 30 are configured as an air cooling type or a water cooling type, and are configured as an integral type or an independent type.

The main intercooler 27 is disposed on the upstream side of the refrigerant so that the amount of cooling is larger than that of the sub intercooler 30.

Primary exhaust port 4a leading to the combustion chamber 2 of each cylinder
The exhaust gas discharged from the secondary exhaust port 4b is sent to the exhaust manifold 10, and is supplied from the exhaust manifold 10 to the turbine 8a through an exhaust passage 12 in which an exhaust switching valve 18 as an exhaust throttle valve is interposed.

An exhaust switching valve 18 is interposed in the exhaust passage 12 between the exhaust manifold 10 and the turbine 8a.
is adapted to be driven by a cylinder 32 serving as an actuator for the exhaust throttle valve, and is always urged into the closed state by a return spring 32b.

The air in the working chamber 32a of the cylinder 32 is then transferred to the electromagnetic on-off valve 2 installed in the communication passage 23.
In the air pump communication state of No. 6, the air is sucked by the air pump 31 and the pressure in the working chamber 32a is reduced, so that the exhaust switching valve 18 becomes open (communicated).

Further, the electromagnetic on-off valve 26 is configured as a three-way switching valve, for example, and communicates the communication passage 23 with the atmosphere and disconnects it from the air pump 31, and communicates the communication passage 23 with the air pump 31. The air pump communicates with the air pump and is disconnected from the atmosphere, and the state is switched in response to a control signal from the control device 25.

The communication passage 23 also communicates with the working chamber 33a of the cylinder 33 as an actuator for the supercharging air throttle valve, and when the pressure inside the working chamber 33a is atmospheric pressure, the cylinder 33 is activated by the return spring 33b to operate the link mechanism. 24, the supercharging air switching valve 19 is closed and the relief valve 20 is opened.

Then, when the pressure in the working chamber 33a of the cylinder 33 is negative, the supercharging air switching valve 19 is opened and the relief valve 20 is closed through the link mechanism 24.

In addition, numerals 13 and 14 in FIG. 1 both indicate intake passages, 15 and 16 both indicate exhaust passages, 17 indicates an exhaust port, and 21 indicates an open port.

Since the engine with an exhaust supercharger as an embodiment of the present invention is configured as described above, when the engine 1 is rotating at low speed and under high load, the control device 2
A control signal is sent from 5 to the electromagnetic on-off valve 26,
The electromagnetic on-off valve 26 is brought into communication with the atmosphere, the air in the working chambers 32a, 33a becomes atmospheric pressure, and the cylinders 32, 33 release their return springs 32b, 33.
b, the exhaust switching valve 18 and the supercharging air switching valve 1
9 is in a closed state, and the relief valve 20 is in an open state.

As a result, the main exhaust supercharger 6 of the primary intake/exhaust system P
The overpressurized supply air from the compressor 6b is cooled by the main intercooler 27, and is supplied to the combustion chamber 2 of each cylinder via the primary intake manifold 5a and the primary intake valve 28. Ru.

At this time, the operation of the secondary intake valve 29 is stopped by the valve operation stop mechanism.

Then, the exhaust gas from the combustion chamber 2 of each cylinder is supplied to the turbine 6a via the exhaust manifold 10 and the exhaust passage 11, and the exhaust gas that rotationally drives the turbine 6a is sent to the exhaust port 17 through the exhaust passage 15.

At this time, the primary air intake port 3a generates a large swirl, so that combustion within the combustion chamber 2 is promoted and high output of the engine 1 can be obtained.

When the rotation of the engine 1 is high or the load is low, a control signal is sent from the control device 25 to the electromagnetic on-off valve 26, and the electromagnetic on-off valve 26 is placed in communication with the air pump, so that the air in the working chambers 32a and 33a is Air is discharged by the air pump 31, the exhaust switching valve 18 and the supercharging switching valve 19 are opened, and the relief valve 20 is closed.

As a result, the main exhaust supercharger 6 of the primary intake/exhaust system P
Both the sub-exhaust supercharger 8 of the secondary intake and exhaust system S operate, and the overpressurized supply air from the compressors 6b and 8b is cooled by the main intercooler 27 and the sub-intercooler 30, and the primary supply air is cooled. The air is supplied to the combustion chamber 2 of each cylinder via the manifold 5a, the primary intake valve 28, the secondary intake manifold 5b, and the secondary intake valve 29.

Then, the exhaust gas from the combustion chamber 2 of each cylinder is supplied to the turbines 6a, 8a via the exhaust manifold 10 and the exhaust passages 11, 12.
The exhaust gas that rotates a and 8a flows through the exhaust passages 15 and 8a.
16 to the exhaust port 17.

At this time, the primary intake port 3a and the secondary intake port 3b work together to supply air with a small swirl and a large amount of air to the combustion chamber 2, thereby making it possible to obtain high output from the engine 1. .

In this way, the operating state of only the main exhaust supercharger 6 and the operating state of both the main exhaust supercharger 6 and the auxiliary exhaust supercharger 8 can be changed to the state of the engine 1, as shown in FIG. You can switch depending on the
As shown in Fig. 3, it is possible to obtain a large output (see reference numeral A in the figure), and since the main intercooler 27 and sub-intercooler 30 are provided, it is possible to obtain a larger output (see the symbol A in the figure). (See symbol B in the figure).

Note that the exhaust switching valve 18 and the supercharging air switching valve 19 can be switched between the fully closed state and the fully open state by appropriately controlling the duty of the control signal sent from the control device 25 to the electromagnetic on-off valve 26. The degree of opening may be adjusted.

[Effect of idea]

As described in detail above, according to the engine with an exhaust supercharger of the present invention, the primary intake and exhaust system is driven by the turbine installed in the exhaust passage of the primary intake and exhaust system of the engine. a main exhaust supercharger consisting of a compressor installed in the intake passage of the
A sub-exhaust supercharger consisting of a turbine installed in the exhaust passage of the secondary intake/exhaust system of the engine and a compressor installed in the intake passage of the secondary intake/exhaust system to be driven by the turbine. An exhaust throttle valve is provided in the exhaust passage of the secondary intake/exhaust system to control the flow rate of exhaust gas supplied to the turbine of the auxiliary exhaust supercharger; an exhaust throttle valve actuator that adjusts the opening degree of the exhaust throttle valve, the actuator comprising a supercharge throttle valve that is interposed to control the flow rate of supercharge air sent from the compressor of the sub-exhaust supercharger; A supercharging throttle valve actuator that adjusts the opening degree of the supercharging throttle valve, and a control device that supplies a control signal to the exhaust throttle valve actuator and the supercharging throttle valve actuator, A cooler is interposed in each of the intake passage of the secondary intake and exhaust system and the intake passage of the secondary intake and exhaust system, and a cooler is installed in the intake passage of the primary intake and exhaust system, and a cooler is installed in the intake passage of the primary intake and exhaust system. A secondary intake valve and a primary intake port for generating a swirl that generates a large swirl in the intake air sent to the combustion chamber of the engine are provided, and the intake passage of the secondary intake and exhaust system is provided with a A secondary intake valve with a valve operation stop mechanism that operates in the load operating range, and a swirl reduction device 2 that reduces the swirl of the air supply sent to the combustion chamber.
With a simple configuration in which a secondary intake port is provided, the following effects and advantages can be obtained.

(1) The strength of the swirl can be selected by the primary intake port for generating swirl and the secondary intake port for reducing swirl, which improves the swirl ratio especially in low speed and high load ranges, significantly improving combustion. be done.

(2) Cooling the supply air increases the amount of air;
The effect of item 1 above is further enhanced, and
Its torque increases and NOx emissions decrease.

(3) Improved engine durability.

[Brief explanation of the drawing]

Figures 1 to 3 show an engine with an exhaust supercharger as an embodiment of the present invention. Figure 1 is its overall configuration, and Figures 2 and 3 are graphs for explaining its operation. FIG. 4 is an overall configuration diagram showing a conventional engine with an exhaust supercharger. 1...Engine, 2...Combustion chamber, 3a...Primary intake port, 3b...Secondary intake port, 4a...
Primary exhaust port, 4b... Secondary exhaust port, 5a
...Primary air supply manifold, 5b...Secondary air supply manifold, 6...Main exhaust supercharger (turbocharger), 6a...Turbine, 6b...Compressor,
7... Intake passage, 8... Sub-exhaust supercharger (turbocharger), 8a... Turbine, 8b... Compressor, 9... Intake passage, 10... Exhaust manifold, 11, 12... Exhaust passage, 13, 14...Intake passage, 15, 16...Exhaust passage, 17...Exhaust port, 18...Exhaust switching valve as exhaust throttle valve, 1
9...Supercharging air switching valve as a supercharging air throttle valve, 20
...Relief valve, 21...Opening port, 23...Communication passage,
24...Air link mechanism, 25...Control device,
26...Solenoid on-off valve, 27...Main intercooler as a cooler, 28...Primary intake valve, 29
... Secondary intake valve, 30 ... Sub-intercooler as a cooler, 31 ... Air pump, 32 ...
Cylinder as actuator for exhaust throttle valve,
32a... Working chamber, 32b... Return spring, 33...
...Cylinder as actuator for supercharging air throttle valve, 33a... Working chamber, 33b... Return spring, P
...Primary intake and exhaust system, S...Secondary intake and exhaust system.

Claims (1)

[Scope of utility model registration request] a main exhaust supercharger consisting of a turbine installed in the exhaust passage of the primary intake and exhaust system of the engine; and a compressor installed in the intake passage of the primary intake and exhaust system to be driven by the turbine; engine 2
The sub-exhaust supercharger includes a turbine installed in the exhaust passage of the secondary intake/exhaust system and a compressor installed in the intake passage of the secondary intake/exhaust system to be driven by the turbine, and an exhaust throttle valve interposed in the exhaust passage of the secondary intake/exhaust system to control the flow rate of exhaust gas supplied to the turbine of the sub-exhaust supercharger; an actuator for the exhaust throttle valve that controls the opening degree of the exhaust throttle valve; The primary intake/exhaust system includes a supercharging throttle valve actuator that adjusts the opening degree of the throttle valve, and a control device that supplies control signals to the exhaust throttle valve actuator and the supercharging throttle valve actuator. A cooler is interposed in each of the intake passage and the intake passage of the secondary intake/exhaust system, and the intake passage of the primary intake/exhaust system is provided with a primary intake valve that operates over the entire operating range of the engine. , a primary intake port for generating a swirl that generates a large swirl in the intake air sent to the combustion chamber of the engine; 2 with valve operation stop mechanism that operates
An engine equipped with an exhaust supercharger, characterized in that it is provided with a secondary intake valve and a swirl reduction secondary intake port that reduces the swirl of the intake air sent to the combustion chamber.