JPS61265340A - Electronic control fuel injecting device of internal combustion engine - Google Patents

Abstract

PURPOSE:To enable a stable fuel injection amount to be always ensured, according to the method wherein, even if detecting precision on the opening of a throttle valve is decreased due to a change with a time and regulation, based on an intake air negative pressure, a fuel injection amount depending upon each operating condition is renewed one by one. CONSTITUTION:In a control device 5, from the opening of a throttle valve 3 detected by a throttle sensor 4 and the detected number of revolutions of an engine, an intake air negative pressure stored in a RAM is researched. From the researched intake air negative pressure and the detected number of revolutions of an engine, a fuel injection amount stored in a ROM is reseached. In which case, when the opening change rate of the throttle valve 3 is decided to be below a given value, an intake air negative pressure stored in the RAM is renewed to an intake air negative pressure detected by a negative pressure sensor 6. After atmospheric pressure correction, based on the researched fuel injection amount, an injection pulse signal is outputted to a fuel injection valve 7 to inject fuel to an engine 1.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to an electronically controlled fuel injection system for an internal combustion engine.

<Prior art> Conventional electronically controlled fuel injection systems for internal combustion engines detect the opening of a throttle valve installed in the intake passage and the engine rotation speed, and determine the throttle valve opening and engine rotation from these detected values. There is one that searches for a preset fuel injection amount (or injection pulse width) based on speed. Then, the detected fuel injection amount is corrected based on the atmospheric pressure detected by the absolute pressure sensor, and the injection pulse signal is output to the fuel injection valve to inject the atmospheric pressure corrected fuel into the engine. We are trying to supply the quantity.

<Problems to be Solved by the Invention> However, in such conventional internal combustion electronically controlled fuel injection systems, the fuel injection amount is set based on the opening degree of the throttle valve, so the fuel injection amount is determined based on the intake air. It was necessary to detect the throttle valve opening with high accuracy in order to supply the engine with accurate response to the current situation. For this reason, it is necessary to strictly adjust the zero point of the throttle sensor (or idle position fIL adjustment) that detects the throttle valve opening at the time of assembly. It was also necessary to adjust the deviation with high precision.

The present invention has been made in view of the above-mentioned circumstances, and provides an internal combustion engine in which the throttle valve opening degree can be detected with high precision and the fuel injection amount can be set with high precision in response to changes in the throttle valve, etc. over time. The purpose is to provide an electronically controlled fuel injection device.

Means for Solving the Problems> For this reason, the present invention aims to improve the opening degree of a throttle valve C interposed in an intake passage B of an engine A as shown in FIG.

an opening detection means for detecting the engine rotational speed, a rotational speed detection means E for detecting the engine rotational speed, an intake negative pressure detection means F for detecting the intake negative pressure in the intake passage B, and a throttle valve opening and the engine rotational speed. a storage means G for storing a fuel injection amount corresponding to an operating condition based on an intake negative pressure; and a search for retrieving a fuel injection amount from the storage means G under the same operating condition as the detected throttle valve opening and engine rotational speed. Means H, a fuel injection device engineer that injects fuel to the engine based on the retrieved fuel injection amount, and fuel stored in the storage means G under the same operating conditions as the throttle valve opening and the engine rotational speed. The fuel injection device includes an updating means J that updates the injection amount to the fuel injection amount retrieved based on the detected intake negative pressure.

In this way, even if the detection accuracy of the throttle valve opening decreases due to changes over time, adjustments, etc., the fuel injection amount corresponding to each operating condition can be updated sequentially based on the intake negative pressure. A stable fuel injection amount can be ensured.

<Example> An example of the present invention will be described below based on FIG. 2.

In the figure, a throttle valve 3 is interposed in an intake passage 2 of an engine 1. Throttle sensor as an opening detection means for detecting the opening of the throttle valve 3? lE installed,
A throttle opening signal αl from the throttle sensor 4 is input to a control device 5, which will be described later. A negative pressure sensor 6 as negative pressure detection means for detecting the intake negative pressure in the intake passage 2 is provided on the wall of the intake passage 2 downstream of the throttle valve 3, and the intake negative pressure signal pvx of this negative pressure sensor 6 is controlled. It is input to the device 5. Further, a crank angle sensor (not shown) is provided as a rotation speed detection means for detecting the engine rotation speed,
The rotational speed signal N1 of this crank angle is transmitted to the control device 5.
has been entered. In addition, a detection signal p,
is input to the control device 5.

The control device 5 controls each of the signals α1 r pvt l P 1
, N1 according to the flowchart shown in FIG. 3, and the fuel injection amount (injection pulse width) by the fuel injection valve 7 is
control.

Note that 8 is an air cleaner.

Next, the operation will be explained according to the flowchart shown in FIG.

It is determined whether the engine is stopped at Sl.

If YES (for example, just before starting the aircraft or when the engine is stalled), the atmospheric pressure P1 detected by the atmospheric pressure sensor is read at N2, and the process returns to Sl.

Further, if NO at SL, that is, when the engine is started, the process advances to N3 and the detected throttle opening signal α
1, the intake negative pressure signal PVI, and the rotational speed signal N1. After calculating the rate of change of the throttle valve opening α in S4, it is determined whether the calculated rate of change is less than or equal to a predetermined value (S5).

When it is determined that the rate of change is less than a predetermined value, that is, the operating state of the engine is determined to be in a substantially steady state, the process proceeds to S6, and the intake negative value stored in the RAM serving as the first storage means in correspondence with the throttle valve opening α and the engine rotational speed N is The pressure is searched under the conditions that the detected throttle valve opening αl and the engine rotational speed N1 are the same as the throttle valve opening and the engine rotational speed in the RAM, and the process proceeds to step 87. Then, the fuel injection amount stored in the ROM serving as the second storage means in correspondence with the engine rotation speed and the intake negative pressure is stored in the ROM with the retrieved intake air pressure and the detected engine rotation speed Nl.
The engine speed and intake negative pressure are searched under the same conditions.

In S8, the intake negative pressure stored in the RAM is updated to the detected intake negative pressure under the same conditions as the throttle valve opening and the engine rotational speed. After the atmospheric pressure is corrected in S9, an injection pulse signal is output to the fuel injection valve 7 based on the fuel injection amount retrieved in 87 in S10, and fuel is injected into the engine 1 from the fuel injection valve T.

Further, when the rate of change exceeds a predetermined value in S5, it is determined that the operating state of the engine is in an accelerated state and the fluctuation in the intake negative pressure is large, and the process proceeds to Sll. Then, similarly to S6, after searching the intake negative pressure stored in the RAM under the condition that the throttle valve opening and the engine speed are the same, in S12, the searched intake negative pressure and the detected engine speed are the same. Search for fuel injection amount under conditions. After that, the process proceeds to 89, and the searched fuel injection amount is corrected to the atmospheric pressure based on the atmospheric pressure read in 82, so that the fuel injection amount corresponds to the intake air flow rate, and then the fuel injection valve T is controlled in 810. do.

Therefore, in this embodiment, the control device 5 constitutes a search means and an update means, and the control device 5 and the fuel injection valve T together constitute a multi-fuel injection device.

As explained above, since the intake negative pressure stored in correspondence with the throttle valve opening degree and the engine speed is updated to the intake negative pressure detected over time, the zero point adjustment of the throttle valve or the throttle valve The fuel injection amount corresponding to the intake air flow rate can be supplied to the engine with good responsiveness without detecting the opening degree with high precision and regardless of changes in the throttle valve or the like over time.

Although the fuel injection amount is stored in the ROM, the energization time of the injection pulse signal corresponding to the fuel injection amount may be stored in correspondence with the intake negative pressure and the engine rotation speed.

<Achievements of the Invention> As explained above, the present invention updates the intake negative pressure stored in the storage means with the intake negative pressure detected over time, so that the zero point adjustment of the throttle valve or the opening of the throttle valve is not necessary. Therefore, the fuel injection amount corresponding to the intake air flow rate can be supplied to the engine with high responsiveness, without detecting the temperature with high precision and regardless of changes in the throttle valve or the like over time.

[Brief explanation of the drawing]

FIG. 1 is a claim correspondence diagram of the present invention, FIG. 2 is a configuration diagram showing an embodiment of the present invention, and FIG. 3 is a flowchart of the same. 1... Engine 2... Intake passage 3... Throttle valve 4... Throttle sensor 5... Control device 6... Intake negative pressure sensor 7... Fuel injection valve time Applicant: Japan 1 Kokiki Co., Ltd. Agent Patent Attorney Fujio Sasajima 1 Inrei 2

Claims (3)

[Claims] (1) An opening detection means for detecting the opening of a throttle valve installed in the intake passage of the engine, a rotation speed detection means for detecting the engine rotation speed, and an intake negative pressure for detecting the intake negative pressure in the intake passage. a detection means, a storage means for storing a fuel injection amount corresponding to an operating condition based on a throttle valve opening, an engine rotational speed, and an intake negative pressure; A retrieval means for retrieving the fuel injection amount from the storage means, a fuel injection device that injects fuel to the engine based on the retrieved fuel injection amount, and a throttle valve opening and an engine rotational speed under the same operating condition. An electronically controlled fuel injection device for an internal combustion engine, comprising: updating means for updating the fuel injection amount stored in the storage means to the retrieved fuel injection amount based on the detected intake negative pressure. . (2) The storage means includes a first storage means for storing the intake negative pressure corresponding to the throttle valve opening and the engine rotation speed, and a second storage means for storing the intake negative pressure and the engine rotation speed,
The electronically controlled fuel injection system for an internal combustion engine according to claim 1, wherein the intake negative pressure stored in the first storage means is updated to the detected intake negative pressure. (3) The updating means updates the fuel injection amount stored in the storage means to the corrected fuel injection amount when the rate of change of the throttle valve opening is less than or equal to a predetermined value. An electronically controlled fuel injection device for an internal combustion engine according to item 1.