JPS6345414A - Internal combustion engine associated with double stage exhaust turbo supercharger - Google Patents

Abstract

PURPOSE:To increase the output of an engine under intermediate and low output zones, by opening an opening regulation valve arranged in the way of a bypass piping under said zones. CONSTITUTION:When a high output is requested during when an engine is operating in an intermediate or low output zone, an opening regulation valve 26 is opened so as to inject fuel from an injection valve 28a and ignite said fuel thus feeding continuous combustion energy from an external combuster 28 through a bypass piping 24 to a turbine 14b. Consequently, kinetic energy being received by the turbine 14b increases thus increasing the supercharge pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement of an internal combustion engine with a two-stage exhaust turbocharger, which is equipped with two stages of exhaust turbochargers.

(Prior art and its problems) This type of internal combustion engine with a two-stage exhaust turbo supercharger has a great effect on increasing output in the high output range, but in the medium and low output range, the low pressure side supercharger The supercharging efficiency is low, which creates resistance, and in the medium and low output range (the 1st stage supercharged internal combustion engine has a larger increase in output).

By the way, regarding the internal combustion engine with two-stage exhaust turbo supercharger,
Japanese Patent Application Laid-Open No. 47-43606 has been known.

In this prior art, FIG. 7.8 (please refer to the publication) discloses a technique to avoid increasing the output of a two-stage exhaust turbocharged internal combustion engine, but in the case of FIG. 7,
In the medium to low power range, there is a risk that combustion gas from the external combustor may flow backwards due to the pressure difference between the intake path and the exhaust path.

Further, in the case of FIG. 8, there is no disclosure of a technique for controlling the flow of supercharged intake air to the external combustor depending on the operating state of the internal combustion engine.

(Objective of the Invention) An object of the present invention is to provide an internal combustion engine with a two-stage exhaust turbo supercharging that can increase the output in the medium and low output range.

(Structure of the Invention) 1) Technical Means The present invention provides a two-stage exhaust turbo supercharger in which an internal combustion engine is provided with a two-stage exhaust turbo supercharger consisting of a high-pressure side supercharger and a low-pressure side supercharger. At the internal combustion engine, a bypass piping is installed to take out a part of the supercharged intake air compressed by the blower of the high pressure side supercharger.
The end of the bypass piping is connected to the part of the exhaust path that connects the turbine of the high-pressure side supercharger and the turbine of the low-pressure side supercharger. This is a two-stage exhaust turbo supercharger internal combustion engine characterized by being provided with an opening adjustment valve that is controlled to open in a medium and low output range.

(2) A part of the compressed supercharged intake air from the blower of the high-pressure side supercharger is taken out to the bypass piping by the opening adjustment valve that opens in the low output range during operation, and is continuously connected to the intake air taken out by the external combustor. Combustion energy is added and supplied to the turbine of the low-pressure side supercharger, improving the supercharging capacity of the low-pressure side supercharger and increasing output.

(Example) In FIG. 1 showing the internal combustion layer employing the present invention, 10
For example, a diesel engine. The diesel engine 10 is equipped with a well-known two-stage exhaust turbocharger consisting of a high-pressure side supercharger 12a and a low-pressure side supercharger 112b, and the turbines 14a and 14b of this two-stage turbocharger are The exhaust path 16 of the diesel engine 10 is connected. Similarly, the air intake path 20 of the f easel engine 10 is connected to the 10 engines 13a and 18t. This intake path 20 is provided with an intercooler 228.22b.

A bypass pipe 24 is branched and connected between the blower 188 and the part of the exhaust path 16 that connects the turbine 14a and the turbine 14b, and an opening adjustment valve 26 is connected in the middle of the bypass pipe 24 from the blower 188 side. , external combustor 28
are interposed in sequence.

A governor (not shown) of the diesel engine 10 is provided with a tachometer 30 that detects the rotation speed of the diesel engine 10, and a detection signal 30a from the tachometer 30 is input to a microcomputer 32 (signal processing device). has been done. Further, an exhaust gas thermometer 34 is provided at the exhaust outlet of the diesel engine 10 to measure the exhaust gas temperature of the diesel engine 10 and detect the engine output, and the detection signal 34a from the exhaust gas thermometer 34 is also transmitted to the microcomputer.
32.

This microcomputer 32 receives detection signals 30a, 3
The operating state of the diesel engine 10 is determined based on 4a, and a control signal V' is sent to control the opening/closing of the opening adjustment valve 26 so that the diesel engine 10 is in a medium/low speed rotation/high load operating section.
2a is now output. Also, control signal 3
2a is an injection valve 28a of an external combustor 28, and an ignition device 28b
is also input, and the function of injecting and combusting fuel in an amount corresponding to the amount of supercharged intake air flowing through the bypass pipe 24 from the injection valve 28a is omitted.

Next, the effect will be explained. Regarding ff1lfi in Figure 1,
For example, if the atmospheric pressure of the intake air drawn into the blower 18b of the low-pressure side supercharging 112b is po, then the pressure of the supercharging intake air compressed by the blower 18b is increased to Pl. Further, the supercharged intake air pressurized by the blower 18a of the high-pressure side supercharger 1'2a is supplied to the diesel engine 10 with its pressure rising to P2.

The pressure of the exhaust gas discharged from the exhaust path 16 of the diesel engine 10 is P3, which drives the turbine 14a of the high-pressure side supercharger 12a, and the exhaust gas that has been pressure sawed down to P4 flows to the turbine 14b, and further to the turbine 14b. and return to PO again.

Therefore, when the diesel engine 10 is operating, regardless of the rotation speed and load of the diesel engine 10, P
2 has a higher pressure than P4. Therefore, the gap 1fJ, the regulating valve 2
6 is an open valve, and a portion of the supercharged intake air flows from the blower 18a toward the turbine 14b due to a pressure difference of P2 >> P4.

In an internal combustion engine with a two-stage exhaust turbo supercharger like the previous three,
Pressure difference P4-Po of low pressure side supercharging fi12b at medium and low output
However, the microcomputer 32 determines the operating state of the diesel engine 10 and sets the supercharging pressure P1 of the low-pressure side supercharging 112b. Or, when high output is required in an operating state where the exhaust pressure P4 is equal to Po, the opening adjustment valve 26 is closed to 11 valves, fuel is injected and ignited from the injection valve 28a, and the external combustor 28 is injected with fuel. continuous combustion energy is supplied from the bypass pipe 24 to the turbine 14b.

Therefore, the kinetic energy received by the turbine 14b increases, and the boost pressure of the blower 18b increases. Therefore, even in operating conditions where the low-pressure side supercharger ell 2b does not generate supercharging pressure, the supercharging capacity of the low-pressure side supercharger n12b is improved, and the supercharged intake air supplied from the intake path 20 to the diesel engine 10 is improved. pressure increases significantly.

As shown in FIG. 2, the characteristic (It increases significantly from characteristic Y.

Naturally, the amount of intake air flowing through the bypass pipe 24 and the amount of fuel injected from the injection valve 28a vary depending on the operating state of the diesel engine 10, but the microcomputer 32 determines the operating state of the diesel engine 10 and adjusts it to that operating state. Outputs the corresponding υItllll signal 32a,
Amount of intake air flowing from the bypass pipe 24 and the injection valve 28a
The amount of fuel injected from the engine is always controlled to the optimum level.

(Effects of the Invention) As explained above, the internal combustion Naruto with two-stage exhaust turbo supercharging according to the present invention has a bypass pipe 24 for taking out a part of the supercharged intake air compressed by the blower 14a of the high pressure side supercharging R12a. The ends of the bypass piping 24 are connected to the turbine 14a of the high-pressure side supercharging 112a of the exhaust path 16 and the low-pressure side supercharging IE11.
An opening adjustment valve is connected to the part that connects the turbine 12b of 2b, and is controlled to open in the middle and low output range depending on the operating state between the external combustor 2B and the internal combustion engine, in the middle of this bypass piping 24. 26, the following effects are achieved.

When the low-pressure side supercharger 12b is in an operating state in which it does not generate supercharging pressure, and when the medium-low speed rotation is high and negative 4F1, the opening adjustment valve 2
6 is opened, fuel is injected from the injection valve 28a, and continuous combustion energy is generated in the external combustor 28)! can be supplied from the bypass pipe 24 to the turbine 14b, the kinetic energy received by the turbine 14b increases, and the supercharging pressure of the blower 18b can be increased. For this reason, conventionally, even in an operating state where the low pressure side supercharger 12b does not generate supercharging pressure (acting as exhaust or suction resistance), the low pressure side supercharger 1ff12
It is possible to improve the supercharging capacity of b, and the intake path 20
The output of the day-pillar engine 10 can be increased as shown by characteristic X in FIG. 2 by significantly increasing the pressure of the supercharged intake air supplied to the diesel engine 10 from the engine.

(Another Embodiment) (1) The present invention is applicable not only to the above-mentioned diesel engine but also to all internal combustion engines such as gasoline engines.

[Brief explanation of the drawing]

The first is a structural diagram showing an internal combustion engine adopting the present invention, the second
The figure is a graph showing output-rotation speed characteristics. 10...
Diesel engine, 12a... High pressure side supercharger, 12
b...Low pressure side supercharger, 16...Exhaust route, 20...
・Intake path, 24... Bypass piping, 26... Opening adjustment valve, 28... External combustion ♂, 32... Microcomputer - Particularly Applicant 1 Yanmar Diesel Co., Ltd. No. 1 J4 No. 2 Diagram @ Rotation number T For procedural amendment (method) % formula % 2. Name of the invention 2-stage exhaust turbo supercharging internal combustion engine 3. Relationship with the case of the person making the amendment Patent applicant address Chayamachi, Kita-ku, Osaka No. 1 No. 32 Name (678) Yanmar Diesel Co., Ltd. Representative Representative Director Atsushi Yamaoka 4, Agent address Chiyoda Building East Building 7N, 2-9-4 Higashitenma, Kita-ku, Osaka (@530) 5. Amended Date of order (starting gate) October 2, 1986
8th (1) "1st" in 4th line on page 10 of the specification is amended to "Figure 1". Hereinafter, F

Claims (1)

[Claims] In an internal combustion engine equipped with a two-stage exhaust turbo supercharger consisting of a high-pressure side supercharger and a low-pressure side supercharger, the compressed air is compressed by the blower of the high-pressure side supercharger. A bypass pipe is provided to take out a portion of the supercharged intake air, and the end of the bypass pipe is connected to the part of the exhaust path that connects the turbine of the high-pressure side supercharger and the turbine of the low-pressure side supercharger. 1. An internal combustion engine with a two-stage exhaust turbo supercharger, characterized in that an opening adjustment valve is provided that is controlled to open in a medium to low output range according to the operating conditions of an external combustor and an internal combustion engine.