SU1237091A3 - Electronic unit injection system for internal combustion engine - Google Patents

Abstract

An electronic fuel injection system for internal combustion engines (1) is described. The main characteristic of this sytem lies in the fact that it comprises first means (7) for supplying the said fuel to at least one injector (5) with a supply pressure which is variable with respect to the pressure in an injection manifold (2) in dependence on a predetermined law, and second means (60) for determining variable delivery times of the said injector (5).

Description

2. Pop-up system 1, characterized in that the fuel pressure regulator contains a device having two chambers separated by at least one elastic membrane, while the chambers are connected

FIELD OF THE INVENTION The invention relates to the field of engine building, in particular, to internal combustion engine control systems, namely electronic fuel injection control systems for internal combustion engines.

The aim of the invention is to improve the accuracy of controlling the amount of fuel injected using a single injector to supply fuel to several engine cylinders.

Figure 1 shows the block diagram of the electronic fuel injection system; Fig. 2 shows a fuel pressure regulator equipped with a single membrane i,; FIG. 3 shows the same, equipped with two membranes; FIG. 4 shows the dependence of the amount of fuel supply on the duration of the control signal received on the injector; in fig. 5 - the same, in davi- ability from a vacuum in the intake manifold at a constant time for opening the injector.

The device contains an engine i with four cylinders, equipped with a suction manifold 2, the injector

3 electromagnetic type, which is the only injector for several cylinders and is located in the intake manifold 2 in front of the throttle valve 4 through the air flow, an electronic unit 5 for controlling fuel injection through the injector and the ignition moment connected to it engine temperature sensor 6, incoming sensor 7 air, rotational speed sensor 8, engine shaft phase sensor 9 (not shown), dilution sensor 10 connected by means of a pneumatic channel 11 to the throttling space of the intake manifold

respectively, for sensing the pressure in the intake manifold and for supplying pressure to the injector, the membrane acting on the element limiting the flow of fuel to the discharge channel of it to the reservoir.

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2 and an ignition module 12, the injector 3 being provided with a fuel pressure regulator 13. connected to the fuel tank via a drain channel 14 and a fuel supply channel 15 connected to pneumatic channel II of the rarefaction sensor 10 and to the fuel channel 16 of the injector 3 and Beaten with the electronic unit 5 control device 17.

The regulator 13 contains lower 18 and upper housing 19, which are connected to each other along the rim by means of a ring 20 folded in such a way as to compress the annular edge of the flexible membrane 21, which defines the upper chamber 22 within the housing 19 and the lower chamber 23 within housing 18. Chamber 22 communicates with pneumatic channel 1 via a connecting tube, chamber 23 communicates with channels 16 and 15 also via connecting tubes.

In the center of the membrane 21, the body 24 is strengthened, the lower part of which causes the seat for the flat valve 25, which co-operates with the connecting hole 26 together with the connecting tube on the channel 1. In this flat valve 25, the coil spring 27 acts on the body 24. The body 24 is located on the other side of the membrane 21 is the support plate 28, on which the spiral spring 29 presses, and this spring with its other end acts on the plate 30, which is installed by means of an adjusting screw 31.

The regulator 13 (fig.Z) is equipped with two elastic membranes 32 and 33, having different sizes, which are crimped along the edges of the upper 34 and 35 intermediate housings, as well as

31

respectively, an intermediate 35 and lower 36 buildings. The intermediate housing 35 defines the intermediate chamber 37, while the upper housing 34 and, respectively, the lower housing 36 define the upper 38 and lower 39 chambers. The different housings 34-36 are preloaded by four bolts.

Pneumatic channel 11 communicates with chamber 38, fuel supply channel 15 and fuel channel 16 with chamber 39. A bolt 40 is fixed on the membrane 32 in the center, which with its upper end holds plate 41, on which there is a spiral spring 42, the other end of which presses a plate 43 held by an adjustable threaded rod 44 screwed into the housing 34. From the lower end side, the bolt 40 is joined to the flat valve 45, which closes the opening communicating with the drainage channel.

The electronic unit 5 contains a central processing unit (CPU), a read-only memory (ROM), an analog-to-digital conversion unit, and a time - master unit.

Electronic ignition system works as follows.

The basis of the system is the existence of a direct correlation between the pressure in the intake manifold 2 and the amount of fuel necessary to achieve the correct force of the mixture in the combustion chamber. This correlation depends on air temperature and engine speed, but is a function that grows (normal) with pressure in the manifold.

The pressure at which the fuel is supplied to the injector 3 through the channel 16 is forcibly changed by means of the pressure control device 17 linearly with the pressure in the manifold 2.

The fuel under pressure is supplied from the fuel pump through the fuel supply channel 15 to the inlet of the regulator 13, the fuel pressure.

The fuel pressure regulator 13 adjusts the pressure depending on a predetermined law determined by the haacteristics of the regulator 13 itself, relative to the pressure in the inlet collector 2.

370914

By choosing the appropriate design characteristics of the injector 3 and the pressure regulator 13, the operation zone of the device is arranged in such a way that it includes the necessary working area of the engine.

In the permanent memory (ROM) of the electronic control unit 5, the correspondence between the input to values (pressure Pc, in the intake manifold 2) and the rotational speed signal of the engine 1, which provides a binary number defining the working time for the injector 3, is tabooed. 15, this number is corrected in the following table depending on the signal that detects the air temperature in collector 2 in order to detect a signal corresponding to changes in air density in collector 2 due to temperature fluctuations.

If necessary, the electronic control unit 5 may have programs for changing the magnitude of the output signal 25 under various operating conditions of the type:

idle changes to increase or decrease the fuel feed rate; 30 acceleration correction;

start correction (for example, by detecting the water temperature value in engine 1 by means of sensor 6);

 correction of the specific control moment of the injector 3; slowdown correction; ignition timing correction.

In the proposed electronic injection system, it is possible to change the pressure supply to the injector, depending on a given law, determined by the characteristics of the fuel pressure regulator 13, and also due to

5 controlling the regulator 13 by means of the pressure in the intake manifold 2 further downstream of the throttle valve 4.

In accordance with this electronic

0, the control unit 5 determines the operational time required for the injector 3 in order to determine the necessary feed rate as a function of the variability of the fuel supply pressure; the signal controlling the electronic control unit 5 is actually determined by determining the pressure in the manifold 2.

512370916

The proposed system can be applied, the method can be modified with a set of injectors from the response of the signal at block 5 of the adjustment of their characteristics to the control, and can also be missing. flow rate changes, actuate the air temperature sensor.

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Compiled by P. Filippov L.Gratillo Tehred editor O.Sopko

Order 3102/60 Circulation 523Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Z zhgorod, ul. Project, 4

Phag.5 fnax

Proofreader M.Samborsk

Claims (1)

1. ELECTRONIC FUEL INJECTION SYSTEM FOR THE INTERNAL COMBUSTION ENGINE, comprising an injector located in the intake manifold in front of the throttle body by the air flow, an electronic unit for controlling fuel injection through the injector and the ignition moment, and sensors for temperature of the engine and the incoming air, rotation frequency connected to it phases of the engine shaft, a rarefaction sensor connected by means of a pneumatic channel to the throttle space of the intake manifold, and an ignition module, the injector being equipped with a regulator m of fuel pressure connected to the fuel tank via fuel drain and supply channels, which is characterized by the fact that, in order to improve the accuracy of regulation of the amount of injected fuel, § the fuel pressure regulator is connected to the pneumatic channel of the rarefaction sensor and to the fuel inlet of the injector. SU <„, 1237091 AZ Fig. 1 are respectively suitable for sensing the pressure in the intake manifold and for supplying pressure to the injector, wherein the membrane acts on the element restricting the fuel flow to the discharge channel into the reservoir. Z. The system according to π.1, I distinguish hz by the fact that the fuel pressure regulator contains a device having two chambers separated by at least one elastic membrane, while the chambers are connected1