JPS5828550A - Electronically controlled fuel injector for multicylinder internal combustion engine with auxiliary intake passages - Google Patents

Abstract

PURPOSE:To improve the performance of an engine including auxiliary intake passages for conducting intake jets to the combustion chambers when the load on the engine is light, by operating the fuel injection valves of the cylinders in their ignition order to keep the distribution of fuel appropriate. CONSTITUTION:In a four-cylinder engine, auxiliary intake throttle valves 40a- 40d are provided in intake passages 15a-15d ramified from a surge tank 14 to the cylinders and auxiliary intake passages including jet ports 48a-48d opened near intak valves are provided detouring the auxiliary intake throttle valves. Fuel injection valves 34a-34d are installed downstream to the throttle valves 40a-40d. The injection valves 34a-34d are operated in prescribed ignition order by an injection valve drive circuit 62 which is regulated by an electronic controller 26 which determines an injected fuel quantity on the basis of an ignition signal and the air flow rate signal of an air flow meter 18 and sends out a fuel injection instructing signal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present vhW14 relates to a spark ignition internal combustion engine O fuel supply technology, and more specifically, to an electronically controlled fuel injection system for a multi-cylinder internal combustion engine.

Fuel supply methods for spark-ignition internal combustion engines can be roughly divided into two types: a method using a carburetor and a method using a fuel injection valve. The latter is a relatively recently developed technology that has been attracting attention in recent years from various perspectives including exhaust gas countermeasures. .

That is, the main advantage of the fuel injection method in a spark-ignition internal combustion engine is that by providing two fuel injection valves in each cylinder's intake boat, each injection valve can inject a similar amount of fuel to each other. Since it is possible to equalize the amount of fuel supplied to each combustion chamber, the problem of fuel distribution between cylinders inherent in the carbureted IIK system is solved, and as a result, the engine becomes leaner. Na II! HC making it possible to convert foundry mixtures.

It is possible to reduce the generation of harmful unburned organisms such as CO. The first method of making a fuel injection valve is a continuous injection method that injects fuel continuously from the injector, and a pulse injection method that injects fuel intermittently. It is adapted to be excited by an injection command in the form of a pulse. This system is called an electronically controlled fuel injection system (EFI), and the technology to which the present invention is directed also belongs to this system. In the conventional electronically controlled fuel injection system, 411i
The fuel injection timing is set so that all fuel injection valves are injected at the same time (simultaneous injection method), and the number of injections depends on the engine operating cycle. ! !
Fi is twice once in a row.

On the other hand, in today's engines, whether fuel-injected or carburetor-based, the intake port profile is generally relatively large in diameter and straight in order to maximize power output during high-load, high-speed operation. ◎ However, if the intake port is shaped like this, sufficient turbulence will not be generated in the mixture sucked into the combustion chamber during low-speed, low-negative W operation. ,
If the flame propagation speed is increased, the flame cannot be sharpened. A method of generating a turbulent flow of Kll air intensity during low-speed, low-load operation is to forcibly generate a swirling flow in the combustion chamber by making the intake port a helical shape or by using a shroud valve. However, these methods have a problem in that the ventilation resistance to the intake air mixture flow increases, resulting in a decrease in filling efficiency during high-speed, high-load operation. Therefore, in a carburetor type engine, artificially operated 1. If a first throttle valve and an auxiliary throttle valve located downstream of the first throttle valve are fully closed only at low loads, the main intake passage between the first throttle valve and the auxiliary throttle valve can be connected by a pipe. A sub-intake passage branch pipe is led to the communication pipe, and is branched from the communication pipe to the K111 outlet near the intake port, and a sub-intake passage that bypasses the auxiliary throttle valve is created with the upper P pipe, the communication passage, and the branch pipe. When the load is low, the auxiliary throttle valve is closed or slightly closed, and a strong mixture jet is ejected from the auxiliary intake passage to promote the generation of turbulent O in the combustion chamber to improve combustion, while at high load the KF
In this specification, an umbrella (Japanese Patent Laid-Open No. 53137320) is proposed to prevent a decrease in output by fully opening the main intake vent vi to minimize intake resistance.
For convenience, this method will be abbreviated as the sub-intake passage type turbulence generation method.

When applying the upper adjustment air overflow type TIL generation system to an engine that has a conventional O vaporization IlI, the rigid air overflow ysoh branch pipe is located downstream of the vaporization (one throttle) valve. ] Since a homogeneous air-fuel mixture is formed in the carburetor, even if the air-fuel mixture is divided into the branch pipes of the auxiliary intake passage, the fuel distribution between the cylinders will not deteriorate. However, the intake manifold is O! Branch tube or individual O intake port) Klil! Due to the combination of the conventional injection system that simultaneously injects the mI air and the above-mentioned mI air aS type tII-generation system, the oxygen distribution between the cylinders deteriorates, and the sub-intake passage improves the combustion performance. ! There was a problem in which the engine torque change increased due to the decrease in sacrifice ratio O fluctuation. ・Zero*@ is intended to eliminate the above problem tS, &40
The idea is to combine the electronically controlled fuel injection system with the upper rigid ventilation hole and the two vertical holes to provide a fuel supply device with a blackened fuel distribution system. It secures O output during high-speed, high-load operation, and prevents O-torque during low-speed, low-load operation, making it possible to run the engine with a dilute (1-ton) fuel mixture, thereby improving operating costs. The present invention aims to reduce the harmful exhaust gas components O◎ The present invention solves the above deterioration of fuel distribution by simultaneously injecting the fuel at a certain period of time and causing a drop in the intake port of each cylinder. When the cylinder that contains the fuel reaches the intake capacity 11, it flows through the communication pipe and flows into that cylinder.As a result, the intake line is sequentially
Based on the knowledge that the amount of fuel entering the eye is destroyed by 1%, the present invention is based on the following points.
In order to prevent this, a synchronous independent injection system is proposed in which the fuel injection valves of each cylinder are activated in sequence according to the ignition order.Hereinafter, embodiments will be described with reference to the attached drawings. 01111
1 shows the metal body arrangement of the engine with zero bag 110 electronically controlled fuel injection system tAt, II intention is the th yaor
It is an x-n sectional view. The figure shows a four-cylinder engine, and as is well known, a cylinder head 6 equipped with a valve system and intake/exhaust ports is attached on top of the four cylinder tabs 4 in which cylinder pores 2a to 24 are formed. 27 A fuel hook 10 is installed between the piston 8 and the cylinder head 6 that reciprocate therein. cylinder head 6
0 Intake KFi mold air manifold 12 and surge tank 1-4 are attached to KII, and this intake manifold 13 cylinder head SKm! Ink base 13 and several m
0 consisting of four branch pipes 15a to 15d extending from
For the moldy air, there is an air cleaner 16, a friend O air flow meter 18 that measures the intake air flow rate, and a sutotle pulp 20f.
It is guided to the surge tank 14 through the throttle body 22 equipped with it, and the intake manifold 12! ! 026, which is designed to be used as a fuel hook, is inserted through the intake port 24 formed in the cylinder head 6. Well-known electronic control system: The L-ET (ECU) controls the intake air flow from the air flow meter 18.
j, St-"f Intake temperature dragon installed in the flow meter 28
From the O intake temperature signal, the signal from the throttle position sensor 30 installed on throttle day 22, the O signal from the cooling water temperature sensor 32, the signal from the engine rotational speed sensor (a!!l not shown). , etc., to calculate the fuel injection amount and output the fuel injection command signal.◎The intake manifold 12 has fuel injection valves 34a to 34 for each cylinder.
Each fuel injection valve 34 is supplied with fuel from a fuel pump (not shown) via a fuel hose 36 and a delivery pipe 38.The fuel injection valve 34 is an omniscient electromagnetic injection system having a solenoid pipe. A valve injects fuel into the intake port 24 in response to an injection command signal from the electronically controlled Enit 26.
Spray toward.

Each intake manifold branch pipe 15 has an auxiliary throttle valve 401 to
40d are provided, and these are Kfk so as to be interlocked by a common axis 4mKX.The 0 axis 42 is, for example, v#[@
55-75531 KR indicating f'Lf control valve 44
>1. Auxiliary throttle valve 4 when operating the engine at low load
On the other hand, in the cylinder head 6,
A 4-diameter jet port 48 substantially parallel to the intake port 24
a to 48d are formed for each cylinder C, these O
As is clear from the new surface of the jet port shown in Fig. 2 and indicated by a dot in Fig. 1, the intake valve! 5GOJI
Ports 24f) are opened in the vicinity of the terminal end in a direction approximately tangential to IIK, so that when air is sucked in from these jet ports, a turbulent flow or a stool is created in the firing chamber. . Each jet port 48 is in communication with each other by a longitudinally extending communication passage 52 formed in the base 13 of the two-fold 120, while this communication S is connected, for example, to the wall of the intake manifold branch pipe IBe. 1
1 completed*, the auxiliary throttle 9 valve 401 is connected to the surge tank 14t) Pl*Wc through the ii passage 54 ◎Passage s4, communication 9152% Jet ports 481 to 4g4 are
With this configuration, when the auxiliary throttle valves 40a to 40 are fully closed during low-load operation of the engine, intake air is exclusively supplied from the rigid intake passage, and no turbulence fLt occurs in the combustion chamber. In order to generate the ignition pulse, there is a distributing valve shown by the reference number s6 at the bottom of Figure 1, and its rotating shaft has a rotor for generating ignition pulses with eight protrusions and a rotor for cylinder discrimination having one protrusion. On the other hand, the ignition pulse detection sensor 5 is installed at a position corresponding to each rotor on the housing tQj of the distributor.
8 and a cylinder discrimination sensor 60 are installed.

Each of the fuel injection valves 34a to 34d is sequentially operated by an injection valve drive circuit 62 according to the ignition order. 311 is a block diagram of an electronically controlled injection device including this injection valve drive circuit 62. , the ignition pulse detection sensor 58 (@1 mmN) of the distributor 56 is connected to the electronic control unit 26 via the waveform shaper 64 and the flip-flop 6.
and one input terminal of the shift register I68. On the other hand, the cylinder discrimination center T60 provided in the distributor 56 is connected to the other input terminal of the shift register metal 8 in consideration of the other waveform shaper 70. The fuel injection command signal output S of the electronic control unit 26 and the output section of the shift register 680, which are connected to
72d is connected to the pace Kg of transistors 74m-74d via a resistor. Each transistor 74a to 74d
The collector is for each fuel injection, valve renoids 76a to 76.
It is connected to the power supply via dl, and the construction ivy is grounded. In addition, solenoid 76 is installed in the IN cylinder, 76bFi 2nd cylinder Km 76c is installed in the 3rd cylinder, and 76d is installed in the 1L cylinder.
Each corresponds to the 14th cylinder.

Next, the operation of this electronically controlled I&fuel injection system will be explained with reference to FIG. 4 and the subsequent drawings. As the ignition pulse generation rotor of the distributor 56 rotates in conjunction with the engine crankshaft, the ignition pulse detection sensor 58 outputs an electrical signal. This electrical compensation is shaped by a waveform shaper 64 to obtain the pulse signal shown in Figure 4 (a). This pulse signal is frequency-divided by a 7-rip, 70-rub 66 to obtain a pulse signal of IIE4, etc., which is input to one terminal of a shift register 68. A signal from the cylinder discrimination sensor 60 is input as a shift pulse to the other terminal of the shift register. Therefore, the pulse signals in Fig. 4, etc.) are sequentially shifted to the right.
, the shift register 68 outputs a pulse signal corresponding to one of FIGS. 4(c) to 4(f) to each AND gate 72. On the other hand, as is well known, the electronic control unit 26 determines the injection amount based on the signal from the air flow meter 18 and the ignition signal, and sends the I! to AND gate 72. Figure 4 (g) K
A fuel injection command signal is output. therefore,
Each AND gate 72a to 72d is shown in FIG. 4(c) to (f).
%1 only when the pulse of and the pulse of -) in the same figure overlap.
Outputs # signal. Triggered by this output signal, the collector and emitter of each of the transistors 74a to 74d are brought into conduction, and the current of the fuel injection valve's trenoid 76 and 76dK flows to inject fuel. In Fig. 3, the solenoid of the fuel injection valve is No. 1 from the top. @3. The fourth and second cylinders correspond to each other, and the ignition of each cylinder is performed in this order, so fuel injection is also performed in accordance with the ignition order. This situation will be clear from the injection timing chart of the MIFI 11E5Z, which is shown in comparison with the conventional MIFI system.

In the next case where the conventional electronically controlled fuel injection system is combined with the auxiliary intake passage type lL keyaki method, fuel flows in through the auxiliary intake passage communication IIt, so that each cylinder O! Gihi is II
There were fluctuations as shown in @It(a).

Zero light sequentially removes each cylinder's O fuel injector according to the ignition order, so if a certain cylinder has an intake line of 1iK, the hot and other O air injectors will be injected from the air intake boat to the jet boat and through the series a II.
ll) The condition of the incoming air-fuel mixture is the Oka et al. condition for every cylinder. Therefore, each cylinder o! ! The fuel ratio is uniform as shown in Figure 6 (b)! , it is possible to minimize torque fluctuation during low load crawling operation.

[Brief explanation of the drawing]

1111Q 4-cylinder Nishijin O-kura layout with electronically controlled fuel injection system Ii diagram, l! Figure 2 shows the IN diagram ■-[1l
Diagram l1 and diagram Sa are block diagrams of the injection valve drive circuit, 11g
Figure 4 is a waveform diagram showing changes in pulse signals over time, Figure 2 is an injection timing chart, and Figure 6 is a graph comparing air-fuel ratios o*-. ---Intake i two-hold O division tube, 20--throttle knob, 24--intake boat, 26--electronic control unit, 34--・・Fuel injection valve, 40・・
... Auxiliary throttle valve, 48 ... Jet boat, 5
0...Intake valve, 52...Communication path, 54
... Passage, 62 ... Injection valve drive path a,
66...Flip-flop, 68...Shift register, 72...AND gate, 74...
... Transistor, 76 ... Injection valve solenoid 0 Patent applicant Tori Jidofu Kogyo Co., Ltd. Patent attorney Akira Seki Patent attorney Kazuyuki Nishidate Patent attorney Yoshi 1) Masayuki Patent Attorney Akiyuki Yamaguchi Figure 4 (9) Prisoner 5 Figure 6

Claims (1)

[Claims] An auxiliary intake throttle valve is installed in each intake passage downstream of the main intake throttle valve of a multi-cylinder internal combustion engine, and the auxiliary intake throttle valve is almost fully closed during low-load operation. Sub-intake passage t- which bypasses the throttle valve and opens near the intake valve
In an electronically controlled fuel injection koji acid for a multi-cylinder internal combustion engine equipped with an aWK air passage, the fuel injection valve of each cylinder is designed to inject an intake jet from the K11ll intake passage during low load operation of the engine. Electronically controlled fuel injection koji acid that can be created sequentially according to the ignition order of each cylinder.