JPS60222540A - Electronic control type fuel injection device - Google Patents

Abstract

PURPOSE:To enable relieving of idle vibration due to reduction in the number of revolutions of an engine, by a method wherein an increase value during correction of an idle increase is gradually increased from zero to a given increase amount in a given time spent starting with complete explosion time. CONSTITUTION:When en engine is started, an increase amount is set to the rich side than an increase ratio during fundamental injection amount by an increase amount setting means 32 during the starting, and the engine is smoothly migrated to a complete explosion state. Upon completion explosion, setting means 31, 33, and 34 for a fundamental increase amount, an increase amount after the starting, and an idle increase amount, respectively, are actuated, and a fundamental injection amount, always brought to a theoretical air-fuel ratio with the aid of the means 31, is gradually decreased from an injection amount during the starting to a fundamental injection amount by means of the means 32. An idle increase correction is gradually increased from an increase amount value 0 to a total increase amount value in a given time spent starting with a complete explosion time by means of the means 34. This, even if fuel adhered to an intake air passage is rapidly evaporated right after complete explosion, prevents the whole of airfuel mixture from becoming excessively rich, and prevents the occurrence of temporary decreases in the number of revolutions.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electronically controlled fuel injection device that performs electronically controlled fuel increase correction when starting an engine.

(Prior Art) Generally, in an engine equipped with an electronically controlled fuel injection device, an increase in fuel is corrected when the engine is started. That is, when starting the engine (i.e., during cranking), the injection amount is increased by a certain amount as shown by region G in FIG. 1(A) (increase ratio px > /-0 (=basic injection amount)). While the start-up correction is performed to improve the startability of the engine, after the engine starts, that is, after complete explosion, the increase value is changed to the increase value of the above-mentioned start-up increase correction, as shown in the area shown in FIG. 4 (A). It performs so-called startup increase correction, which gradually decreases the injection amount from In Fig. 4(A), area C
As shown in the figure, idle increase correction, which increases the amount of fuel by a certain amount, is performed in parallel to increase the engine speed and stabilize the idle speed. The starter quantity increase correction and the idle quantity increase correction are performed by increasing the fuel quantity by a predetermined amount on top of the basic injection quantity in area d in FIG. ψ (A). In addition, the increase ratio shown in Figure (A) represents the ratio between the total injection amount after correction and the basic injection amount. The case where only the injection amount is injected is shown.

However, in this conventional electronically controlled fuel injection system, the increase correction amount at the time of idle increase correction is shown in Figure 1 (
As shown in B), it was set to increase rapidly from zero to the full increase value at the time of complete engine explosion.
%), the curve L in Fig. ψ (A)
As shown in the fuel injection characteristic diagram shown in 1, the total injection amount immediately after the complete explosion of the engine is larger than the total injection amount at the time of starting fuel injection correction (i.e., fuel injection ratio p1 < fuel injection ratio PJL), and therefore, An incidental condition is that the fuel that adheres to the intake passage during cranking and has accumulated V% is rapidly vaporized and sucked into the cylinder immediately after the engine completely explodes, causing the air-fuel ratio of the mixture to become temporarily rich. As a result of the synergistic effect of Idle speed n
If the engine speed drops below zero and unpleasant engine vibration (idling vibration) occurs, or if the shift lever is put into the driving range when the engine speed drops in a car with an automatic transmission, the engine stalls. There were some problems that could occur.

Incidentally, a known example of an electronically controlled fuel injection device that performs idle increase correction during engine idling operation is, for example, Utility Model Publication No. 57-2603! ; There are some as shown in the publication No.

(Object of the Invention) In view of the above-mentioned problems of the conventional electronically controlled fuel injection device, the present invention has been developed to provide an injector that can be used immediately after the complete explosion of an engine.

The object of the present invention is to provide an electronically controlled fuel injection device that prevents a temporary drop in rotational speed, thereby reducing idling vibration and improving driving characteristics.

(Structure of the Invention) The electronically controlled fuel injection device of the present invention has a basic I for setting the basic injection amount of fuel as shown in the control block diagram of the ts1 diagram.
I-shot kill setting means; startup increase setting means for setting a predetermined injection amount so that the air-fuel ratio of the air-fuel mixture is smaller than the air-fuel ratio at the basic injection amount when cranking the engine; and when the engine is completely detonated. a start-up increase setting means for gradually decreasing the predetermined injection amount over a predetermined period of time; and in addition to the basic injection amount, increasing the amount of fuel for a predetermined period of time or less from the time of complete combustion of the engine when the engine is idling. and an idle increase setting means for gradually increasing the value from zero to a predetermined increase value, and setting the set time elapsed diameter to the predetermined increase value, so that the air-fuel ratio of the mixture temporarily becomes excessive at the engine complete explosion TM diameter. This feature is characterized in that it prevents a dark state from occurring.

(Embodiments) Hereinafter, the electronically controlled fuel injection device of the present invention will be explained based on the embodiments shown in FIGS. 1 to 3.1. FIG. 2 shows an overall system diagram of a fuel supply system of a fuel injection type automobile gasoline engine l equipped with an electronically controlled fuel injection device according to an embodiment of the present invention.

An injector 9 is attached to an intake passage 2 of an engine l. Further, on the outer end side of this intake passage 2, an intake manifold ψ is provided with a surge tank 10 at an intermediate position, a throttle valve is provided on the intake upstream side of the surge tank IO, and an air cleaner t is provided on the most upstream side of the intake manifold. An intake pipe j provided with an air flow meter 7 is connected in sequence.

A bypass air passage l/ that bypasses the throttle valve r is formed in the intake manifold t, and the bypass air passage // opens when the engine l is cold started to increase the amount of intake air. An air valve 2 is installed which acts to increase the idle speed of the engine.

Furthermore, a pressure regulator, 21?, is located at the surge tank 10 position of the intake manifold L. ! +! The negative pressure introduction pipe 23 for I use is opened, and the injection pressure of the fuel that is pressurized and sent to the injector 9 side by the fuel pump 20 and injected into the intake passage λ from the injector 9 is equal to that in the surge tank 10. (that is, when the intake negative pressure is large, the fuel injection pressure is decreased, and when the inverse %Q intake negative pressure is small, the fuel injection pressure is increased). In addition, in Fig. 2, the symbol /
9 is a fuel tank, 2/ is a low pressure side fuel filter, and 2 is a high pressure side fuel filter.

On the other hand, the amount of fuel injected from the injector is controlled by a controller/lr. This controller/lr
As shown in FIG. , the engine speed signal outputted from the ignition enrichment coil 17 (and the engine temperature signal 9 outputted from the water temperature sensor/4', the start signal S6 outputted from the ignition enrichment switch 16, and the output from the throttle sensor 13). The throttle opening signal S is input as a factor for controlling the injection amount.In addition, the start signal output from the ignition switch 16 depends on the ON state of the ignition switch 16 (
That is, the (H) signal indicating the engine cranking state) and the OFF state of the engine switch (i.e.,
It is output as a (L) signal which indicates a complete explosion state).

The configuration of this control 'IBH/l and the specific fuel injection amount control system by the controller/1 will be explained below.
m3 diagram will be explained by using them together on each figure.

The control Her is constituted by basic injection amount setting means 31, starting amount increase setting means 32, starting amount increasing setting means 33, and idle amount increasing setting means 31, as shown in 113th IJ.

The basic injection amount setting means 3/ is set after the complete engine explosion, that is, as a start signal from the ignition switch 16 (L
) When the signal is input, it acts as if setting the basic fuel injection based on the intake air amount and engine speed (see area d* in FIG. 3(A)). Note that the basic injection amount is corrected (air-fuel ratio correction) by the air-fuel ratio signal S1 input from the 02 sensor lj.

The starting increase setting means 32 sets the fuel injection amount so that the air-fuel ratio of the mixture becomes smaller than the air-fuel ratio at the time of the basic injection amount (that is, richer than the stoichiometric air-fuel ratio) during engine cranking. This is to improve the startability of the engine by making sure that the engine has not fully exploded (the start signal is in the H state) and that the engine speed is below the cranking speed (for example, 00 rpm). It is activated by detecting the cranking state of the engine from two points (detected by signal 5), and outputs a start-up increase correction signal Sll to the drive circuit 3S side. In addition, this increase correction at startup is performed in the area ε in Fig. 3 (^).
The increase ratio is P2 > /,
It is set to 0 (that is, the fuel injection amount at the time of startup is corrected to increase by an amount indicated by the increase ratio (PS!-/-0) rather than the basic injection amount). Note that this injection amount is corrected to increase or decrease according to the engine temperature signal S4 from the water temperature sensor III (that is, the lower the engine temperature is, the more the injection kill amount is increased).

The after-start increase setting means 33 sets the start-up increase setter l!
! Increase correction amount (E
3 (A
)) The injection amount is set so as to gradually decrease between A starting increase correction signal is output to the amount setting means 31. Incidentally, this post-start increase setting means 33
The increase correction amount set by is further corrected according to the engine temperature (that is, the injection amount is increased as the engine temperature becomes lower).

The idle amount increase setting means 3II is for increasing the fuel injection amount as a whole by adding a predetermined injection amount to the basic injection amount during engine idling operation, as shown in area C in FIG. 3(A). , the engine is completely exploded and the start signal S6 is in the L state), the throttle opening is set to the idle opening, and the engine speed is below the idle speed (for example, /000 rpm). The control described above is carried out, and an idle increase correction signal S9 is output to the basic injection amount setting means 31.

Also, the increase characteristics during idle increase correction are shown in Figure 3 (B
), the increase value is gradually increased from zero to the specified increase value (increase achieved 81100%) during a predetermined time (timer setting) tb (tb = 2 - Tl) from the engine complete explosion, and the increase value is increased for a predetermined time. After tb elapses, the increase value is set to be fixed at the predetermined increase value.

Next, the injection amount 5III determined by the controller/lr will be specifically explained using an example in which the engine is cold-started and the engine is idled after the start. First, when the engine is cranked, , starting increase setting means 3.
2 is activated, and the increase ratio is set to an increase ratio greater than the increase ratio 1.0 at the time of the basic injection amount, as shown in area C in FIG. 3(A), and the air-fuel ratio of the mixture becomes the stoichiometric air-fuel ratio. It is set on the richer side. Therefore, the startability of the engine is improved, and the engine smoothly transitions from a cranking state to a complete combustion state.

When the engine completely explodes (time τl), in response to the start signal 55 (=L) from the ignition switch 16, the basic injection amount setting means 3/, the starting amount increase setting means 33, and the idle amount increase setting means 31I are activated. Each operation is started.

First, the basic injection amount is controlled by the basic injection amount setting means 31 based on the intake air amount and the engine speed so that the air-fuel ratio of the mixture always matches the stoichiometric air-fuel ratio.

On the other hand, the starting injection amount (increase ratio h) set by the starting increasing amount setting means 32 is determined by the starting diameter increasing setting means M133 at the time of complete explosion of the engine (as shown in FIG. 3(A)). The starting injection amount is gradually decreased from the starting injection amount to the basic injection amount of increase ratio /,0 over the period of tg seconds from fi Tl ) to the time award.

Further, the idle amount increase correction is performed by the idle amount increase setting means 31I.
According to the increase characteristics translated into Figure 3 (B), the increase correction amount is calculated in tb seconds (H) from the time of complete explosion of the engine to time T2.
<tg) to gradually increase from the increase value zero to the full increase value, and after tb seconds have elapsed, the control is such that it is fixedly set to the full increase value.

As a result, the fuel injection amount changes from cranking to time T3 when the starting slow increase correction ends, as shown in the fuel injection characteristic diagram shown by curve L2 in FIG. ) to the increase ratio PL (a state in which only idle increase correction has been performed). Therefore, even if the fuel adhering to the intake passage of the engine suddenly vaporizes and is sucked into the cylinder immediately after the engine completely explodes, the air/fuel mixture as a whole will be reduced immediately after the engine completely explodes. An over-concentrated state will not occur, and as a result, a temporary drop in engine speed immediately after the engine complete explosion can be prevented.

As mentioned above, as a method to prevent the air-fuel ratio of the air-fuel mixture from becoming temporarily overrich immediately after the engine has completely exploded, for example, the increase value of the idle increase correction can be changed to Even if the weight is increased rapidly immediately after detonation, and instead the increase value of the post-start increase correction is reduced by the amount corresponding to the increase value of the idle increase correction at the engine complete explosion diameter, the result is as shown in Figure 3. (A
), this type of entanglement has no problem with entanglement when the engine is running at idle; however, when the engine is started immediately after starting, the engine This is unsuitable because the amount of IRII rapidly decreases at the time of complete explosion (because the amount increased by the idle amount increase correction is lost), resulting in a drop in engine speed.

(Effects of the Invention) The electronically controlled fuel injection device of the present invention provides a starting increase correction that increases the injection amount during engine cranking compared to the basic injection amount when starting the engine, and a starting increase correction that increases the injection amount during engine cranking compared to the basic injection amount. A starter increase correction is performed in which the increase correction amount at the time of correction is reduced after a predetermined time, and an idle increase correction is performed in which the injection amount is added by a predetermined amount on top of the basic injection amount during idling operation after the engine has completely exploded. In the electronically controlled fuel injection system, the increase value during the idle increase correction is gradually increased from zero to the predetermined increase value over a predetermined period of time after the engine complete explosion. As in the case of conventional electronically controlled fuel injection systems, in which the value is suddenly increased from zero to a predetermined increase value at the time of complete engine explosion, the air-fuel ratio in the mixing section is temporarily overrich immediately after the engine complete explosion. The engine speed does not drop when approaching a station, and as a result, the large-amplitude idling vibration caused by a drop in engine speed is alleviated, making it possible to run the engine quietly. This has the effect of preventing the engine from stalling easily and improving the operating characteristics of the engine.

[Brief explanation of the drawing]

FIG. 1 is a control block diagram of an electronically controlled fuel injection device of the present invention, and FIG. 2 is a system diagram of a fuel supply system of an automobile engine equipped with an electronically controlled fuel injection device according to an embodiment of the present invention. Figure 3 (A) is a fuel injection characteristic diagram of the electronically controlled fuel injection system shown in Figure 2, and Figure 3 (B) is the increase in amount during idle volume increase correction in the electronically controlled fuel injection system shown in the m2 diagram. Characteristic diagrams, Figure 1 (A) is a fuel injection characteristic diagram in a conventional electronically controlled fuel injection system, Figure V (B) is an increase characteristic diagram during idle volume increase correction in a conventional electronically controlled fuel injection system, 11 Figure (C) is an engine speed curve in a conventional electronically controlled fuel injection device.・ l...- Engine... Intake passage 3... Exhaust passage l... Intake manifold! ... Intake pipe 7 ... Air flow meter t ... Throttle valve 9 ... Injector 13 ... Throttle sensor /l ... Water temperature sensor 7B ... 02 Sensor 16...Ignition switch 17...Ignition coil/I...Controller, 20...Fuel pump 31...Basic injection amount setting means 32... - Start-up amount increase setting means 33... Start-up amount increase setting means 31I... Idle amount increase setting means 3S... Drive circuit

Claims (1)

[Claims] 1. A basic injection amount setting means for setting the basic injection amount of fuel based on the intake air amount and the engine rotational speed, and a means for setting the air-fuel ratio of the mixture to be smaller than the air-fuel ratio at the basic injection amount when the engine is cranking. A start-up increase setting means for setting a predetermined injection amount; a start-up increase setting means for gradually decreasing the predetermined injection amount over a predetermined period of time from the time of engine complete explosion; idling increase setting means for gradually increasing the increase value from zero to a predetermined increase value in a set time that is less than or equal to the predetermined time from the complete explosion of the engine at the time of the engine, and setting the increase value to the predetermined increase value after the set time has elapsed; An electronically controlled fuel injection device characterized by: