JPS5810146A - Output controlling method of spark-ignition internal- combustion engine - Google Patents

Abstract

PURPOSE:To improve a thermal efficiency by a method wherein a mixture gas is heated by a discharged heat of the engine, the heating temperature is controlled to control an output of the engine and a pumping loss of the engine under a partial load is eliminated. CONSTITUTION:In a heat exchanger 8, one end of the heating chamber 11 is communicated with a discharged gas manihold of the main body 4 of the engine through a discharged gas branch passage 13 and the heating chamber 11 surrounds an outer circumference of the intake pipe 10, several heat pipes 14 are extended from the inside of the heating chamber 11 into the intake 10, a plurality of rows of heat pipes 14 are radially arranged and fins 15 are provided in order to improve a thermal efficiency. In a range of partial load, the gas is heated by a heat of the discharged gas through the heat exchanger 8 when the gas passes through the intake pipe 10. The gas is suctioned into the combustion chamber 5 through the intake valve 6 and then combustioned therein. Thus, it is possible to eliminate a pumping loss and improve a thermal efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an output control method for a spark ignition internal combustion engine such as a gasoline engine.

Conventionally, the output control of an internal combustion engine as described above has generally been performed using a throttle valve, as illustrated in FIG. In FIG. 1, reference numeral 1 is an intake system, 2& is a carburetor, 3 is a throttle valve provided in the intake passage of the carburetor 2, 4 is an engine body, and 5 is a III combustion chamber provided in the engine body 4.
The combustion chamber 5 communicates with the intake system 1 via an intake valve 6, and communicates with the exhaust system via an exhaust valve 1. In such an engine, the output is controlled by controlling the boost pressure with the throttle valve 3 installed in the intake system 1.
Bumping loss is large during partial load.

That is, the output N of the internal combustion engine mentioned above is determined by the fuel flow rate G (
Since it is proportional to kMs), it is NCCG.

If the air-fuel ratio is λ (A/G, where A (kMs) is the air flow rate), it can be replaced with NCcA/λ.

The displacement of the engine is V (CO), and the rotation speed is n (rpa).
Then, since AOcρVn (where ρ is the air density), Noc, oVn/λ---(1), and since v, n, and λ can be regarded as almost constants, NC
It becomes Cρ.

Also, the pressure pb on the downstream side of the throttle valve in the intake system (corresponding to the suction pipe boost), 11 degrees is T (if the absolute side is 1, then ρ
Since ωPb /T, the above equation (1) is NQll'P
b /T---(2). In this engine, the throttle valve causes a pressure drop in the air-fuel mixture to control the output Iil, so the pressure on the upstream side of the throttle valve is
If the pressure drop due to the throttle valve is ΔP, then the output is Pb-Po-ΔP (3). Bumping loss Lp is 1poC(p'j -Pb) if back pressure is P'
Dairy with milk.

Therefore, in order to reduce the pumping loss in the partial load range of the engine, it is recommended to delay the closing timing of the intake valve.
E Paper (No, 800794. Con
trollin.

Engine 1load by Means
of ,Late Intake Valve C
1 osino), and was also published in Japanese Unexamined Patent Publication No. 11/1983.
This is proposed in Publication No. 2814. However, these Taiichi methods have problems such as a complicated mechanism, troublesome output control, and an excessive amount of burned gas remaining in the cylinder in a low load range.

This invention was made by focusing on the fact that from the above equation (3), Noc(PO-ΔP)/T---(4), and the density changes by changing the temperature of the air-fuel mixture. At a suitable place between the position corresponding to the throttle valve position of the intake system and the intake valve, the exhaust heat of the engine is used to heat the air-fuel mixture, and the heating temperature is controlled.
By combusting the air-fuel mixture whose heating temperature is controlled and controlling the engine output, the above-mentioned problem can be solved with a relatively simple configuration that prevents excessive residual burnt gas from remaining in the cylinder even in the low load range. The engine can be operated stably without any problems, and furthermore, when ΔP is 0. P.

Since is constant, NQII! 1/T, it is possible to eliminate or sufficiently reduce the pumping loss, greatly improving fuel efficiency in the partial load range, and by controlling the heating temperature, it is also possible to control the output. The object of the present invention is to provide a method for easily controlling the output of a spark ignition internal combustion engine.

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 2 and 3. In FIGS. 2 and 3, the symbol @8 is a heat exchanger, and this heat exchanger 8 connects between the carburetor 2 of the intake system 1, which does not have a throttle valve, and the intake manifold 9 of the engine body 4. It is integrated into the suction pipe 1G that communicates with it. In addition, in the heat exchange I8, one end of the heating chamber 11 is communicated with the exhaust manifold 12 of the engine main body 4 via the exhaust distribution passage 13, and the heating chamber 11 is formed surrounding the outer periphery of the intake pipe 10. A large number of heat pipes 14 extend from the heating chamber 11 into the suction pipe 10, and these heat pipes 14 are arranged radially in a plurality of rows, and are provided with fins 15 to improve heat exchange efficiency.

The other end of the heating chamber 11 communicates with the exhaust manifold 12! ! 18 through an exhaust path [1116], and a vJIll valve 17 is provided at the outlet of this exhaust gas recirculation path 16. In addition, in Fig. 2, 5 is a combustion chamber, 6 is an intake valve,
7 is an exhaust valve.

In the spark-ignition gasoline engine according to one embodiment of the present invention configured as described above, the air-fuel mixture produced by the carburetor 2 is
In the partial load region, when passing through the suction pipe 10, the heat exchanger 8
The combustion gas is heated by the heat of the exhaust gas, is sucked into the combustion chamber 5 through the intake valve 6, and is combusted, and the combustion gas is discharged through the exhaust valve 1, the exhaust manifold 12, and the exhaust pipe 18. Further, as shown by the arrow in FIG. It is returned to the atmosphere. The beat pipe 14 performs a circulation in which the heat medium sealed inside the heating chamber 11 evaporates, is cooled by heat exchange with the mixture in the suction pipe 10, is condensed, and is returned to the interior of the heating chamber 11. , the air-fuel mixture in the suction pipe 10 can be efficiently heated. Then, by controlling the opening degree of the control valve 11g) by an appropriate means such as operation with an operating lever, the flow of the exhaust gas to the heating chamber 11 is controlled to change the heated concentration of the mixture,
Controls engine output by changing the density of the air-fuel mixture. In this case, the engine output increases as the concentration of the air-fuel mixture decreases, so in the case of full load, the III valve 11 is closed (all 11 exhaust recirculation passages 1G) to prevent heating of the air-fuel mixture. It's okay.

Another embodiment of the invention shown in FIG. 4 differs in construction from the embodiment shown in FIGS. 2 and 3 in that an auxiliary throttle valve 19 is provided in the carburetor 2. Therefore, parts corresponding to those in FIG. 2 are given the same reference numerals in FIG. 4, and their explanation will be omitted.

In the embodiment shown in FIG. 4, since there is a response delay if only the -jiMI valve 17 is operated, the throttle valve 19 is opened and closed during sudden acceleration and deceleration to compensate for the response delay, and the maximum thermal maximum is adjusted as necessary. Even when more heat is required, the throttle valve 19 is used as an aid.

In this way, the control method according to the present invention can be applied to an engine, such as an engine installed in an automobile, which has frequent load fluctuations such as sudden acceleration and deceleration.

The conventional method shown in FIG. 1, one embodiment of this statement shown in FIGS. 2 and 3, and another embodiment shown in FIG. As is clear from comparing b) and (0), the pumping loss is Lp cX
Knee (Pr - Pb) There is a large pumping loss as shown by diagonal lines in Fig. 5(a) in the conventional method, whereas in the control method according to an embodiment of the present invention, the pumping loss is large as shown in Fig. 5(b).
In the control method of the other embodiment, the suction pipe negative pressure pb is smaller than in the conventional method, so the pumping loss is small as shown by diagonal lines in FIG. 5(0).

In addition, in the present invention, the heat exchanger is not necessarily limited to that of the above embodiments, and any suitable heat exchanger can be used. Further, the present invention is applicable to heating means, as long as the air-fuel mixture is heated using exhaust heat of the engine, such as cooling water after cooling the engine body instead of exhaust gas, and the heating temperature is controlled. The control means can be changed as appropriate, and the heating portion may also be a suction manifold.

Further, although this embodiment has been described using a carburetor type fuel supply system, a fuel injection type fuel supply system is also applicable.

As explained above, the output method according to the present invention is as follows:
The engine's exhaust heat is used to heat the air-fuel mixture, and the heating concentration is controlled to control the engine's output, which eliminates or reduces pumping at partial loads and significantly improves thermal efficiency, or fuel efficiency. 9 can be achieved early on for one aircraft, improving drivability, improving fuel-air mixture distribution by promoting fuel vaporization, and making it easier to control output with a Western-style configuration. Furthermore, it has the advantage of being able to operate the engine stably even in the low load range.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the configuration of the engine body and intake system of a conventional spark-ignition internal combustion engine, FIG. 2 is an explanatory diagram of the configuration of essential parts of a spark-ignition internal combustion engine according to an embodiment of the present invention, and FIG. The figure is a cross-sectional view taken along the line ■-■ in FIG. ) is an explanatory diagram showing the pumping loss of a conventional engine and the pumping loss of two embodiments according to the present invention. 1... Intake system, 2... Carburizer, 3... Throttle valve, 4... Engine body, 5... Combustion chamber, 6...
Suction valve, 1...Exhaust valve, 8...Heat exchanger, 9...
Suction manifold, 10... Suction pipe, 11... Heating chamber, 12... Exhaust manifold, 13... Exhaust branch flow path, 14... Heat pipe, 15... Fin, 1
6... Exhaust recirculation path, 11... Control valve, 18... Exhaust pipe, 19... Throttle valve. 9- Figure 1 Figure 2 11i4WI 2 Figure 6 (0) (1) ) (C)

Claims (1)

[Claims] Heat exchanges exhaust heat from the engine with the air-fuel mixture at a suitable location between the intake valve and the intake valve, corresponding to the throttle valve position of the intake system.
The mixture is heated and the heating concentration is controlled, heating 8! A method for controlling the output of a spark ignition internal combustion engine, the method comprising controlling the output of the engine by combusting an air-fuel mixture whose temperature is controlled.