JPH02298648A - Electronic control type fuel injection device for engine - Google Patents

Abstract

PURPOSE:To improve the starting performance and acceleration performance at the cold time, by presuming octane number of fuel according to ignition timing set through knocking control, and increasing the quantity of fuel at the cold time according to the octane number. CONSTITUTION:The occurrence of knocking in an engine is detected by a means A. The ignition timing is controlled by a means B according to a detected signal from the means A. Fuel injection quantity at the time of cold engine is increased and corrected by means C. Namely, the ignition timing is retarded or advanced according to the existence of the occurrence of knocking. The ignition timing is controlled as ignition timing for the obtaining of maximum torque within the area of the no occurrence of knocking. As a result, as the higher the octane number of used fuel is the ignition timing for the occurrence of the knocking is shifted to an advance side, so that fuel increasing correction at the cold time as mentioned above is carried out.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electronically controlled fuel injection device for an engine that increases the fuel injection amount when the engine is cold according to the octane number of the fuel being used. be.

[Conventional technology]

Conventionally, high octane control ■ (compression ratio.

ignition timing, air-fuel ratio, etc.) and the control amount for low octane number, the octane number of the fuel used is detected based on the state of occurrence of knocking, and the octane number for high octane number stored above is determined according to the detection result. A control device that performs control by switching between a control amount and a low octane number control amount has been disclosed (for example, Japanese Patent Application Laid-Open No. 60-75730).

In addition, the ratio of aromatic hydrocarbons contained in the fuel used is detected, and the octane number of the fuel used is estimated according to this ratio of aromatic hydrocarbons. Sometimes, to prevent the plug from smoldering,
A control device that performs a reduction correction on the fuel injection amount has been disclosed (for example, Japanese Utility Model Application No. 169245/1983).

[Problem to be solved by the invention]

There is a characteristic that the temperature at which the fuel reaches the same distillation degree increases as the octane number increases. Therefore, when using high-octane fuel in a device where the fuel injection amount is set assuming low-octane fuel, the fuel may easily vaporize, especially when it is cold, so the required air pressure may be reduced. There were times when the fuel ratio could not be obtained, resulting in poor starting and poor acceleration.

However, in the above-mentioned apparatus, no measures have been taken to solve the above-mentioned problems.

The present invention has been made in order to solve the above-mentioned problems, and its purpose is to increase the amount of fuel injected during cold periods according to the octane number of the fuel used. The objective is to improve startability and acceleration when cold.

[Means to solve the problem]

Therefore, as shown in FIG. 1, the present invention includes a knocking detection means for detecting the occurrence of non-king in the engine, an ignition timing control means for controlling the ignition timing according to a signal from the knocking detection means, and an ignition timing control means for controlling the ignition timing according to a signal from the knocking detection means. The gist of the present invention is an electronically controlled fuel injection device including a correction means for increasing the amount of fuel injected during cold conditions in accordance with a set ignition timing.

(Operation) As described above, the non-king detecting means detects the occurrence of knocking in the engine. Based on this detection signal, the ignition timing control means retards the ignition timing when non-knocking occurs, and advances the ignition timing when knocking does not occur. Therefore, the ignition timing is controlled to obtain the maximum torque within a range where knocking does not occur.

Therefore, the higher the octane number of the fuel used, the more advanced the ignition timing at which knocking occurs, so the correction means performs an increase correction during cold conditions in accordance with the ignition timing controlled by the ignition timing control means. Performed for fuel injection amount.

〔Example〕

An embodiment of an engine to which the present invention is applied will be described below with reference to FIGS. 2 and 3.

FIG. 2 is a configuration diagram showing the configuration of the embodiment. In FIG. 2, engine 1 is a four-cylinder spark ignition type engine mounted on a vehicle. The intake pipe 2 of the engine 1 includes an intake temperature sensor 3 that detects the intake temperature from the upstream side, and a throttle opening sensor 5 that detects the throttle opening of the throttle valve 4.
, an intake pressure sensor 6 for detecting pressure on the downstream side of the throttle valve 4, and an electromagnetically actuated injection valve 7 for supplying fuel to the engine 1. The engine 1 is also provided with a spark plug 8, a temperature sensor 9 for detecting engine temperature (cooling water temperature), and a knock sensor 10 as a non-knocking detection means for detecting knocking. Further, the spark plug 8 is provided with an igniter 11 and a distributor 12, and the distributor 12 is provided with a rotation speed sensor 13 for detecting the engine rotation speed.

The signals from each of the above sensors are input to the ECU 15, and the ECU 1
5 outputs a control signal to the injection valve 7 and the igniter 11. In detail, the ECU 15 calculates the basic injection time width and basic ignition timing based on the intake pressure and rotation speed, corrects them based on the intake air temperature, throttle opening, engine temperature, and knock detection, and calculates the current injection time. The width and ignition timing are determined, and control signals corresponding to each are output.

In this embodiment, when knocking is detected by the knock sensor 10 during the knocking determination time (engine combustion period), the ignition timing is immediately retarded by a predetermined value,
When non-king is not detected, ignition timing control is performed to gradually advance the ignition timing.

Here, since the ignition timing advances as the octane number increases, the octane number of the fuel being used can be estimated by observing the ignition timing during the non-king determination period.

Next, fuel injection amount control processed by the ECU 15 will be explained based on the flowchart shown in FIG.

Steps 100 to 107 are ignition timing control means, and steps 108 to 110 are correction means.

First, in step 100, it is determined whether or not it is a knock determination period. If it is the knock determination period, it is determined in step 101 whether or not a non-king occurs. If knocking is occurring here, in step 102, the previous ignition timing AESA is retarded by 1 to a predetermined value and set as the current ignition timing AESA. In the following step 103, it is determined whether the current ignition timing AESA is smaller than the minimum advance amount ABSE1. Here, the minimum advance angle 1ABsE1 is the ignition timing determined by the intake pressure and rotation speed when regular fuel is used. If the current ignition timing AESA is smaller than the minimum advance angle ff1ABsE1, step 10
4, set the current ignition timing AESA to the minimum advance amount ABSEI.
Set to .

Further, if knocking has not occurred in step 101, the previous ignition timing AESA is advanced by 2 to a predetermined value in step 105, and the current ignition timing AESA is set as the current ignition timing AESA.

In the following step 106, it is determined whether or not the current ignition time wIAESA is larger than the maximum advance angle amount ABsE2. Here, the maximum advance angle fiABSE2 is the ignition timing determined by the intake pressure and rotation speed when high-octane fuel is used. and,
If the current ignition timing AESA is larger than the maximum advance angle 1ABsE2, in step 107, the current ignition timing pJ4A
Set EsA@maximum advance angle amount ABSE2.

Then, in step 108, an advance angle X is calculated to determine how far the current ignition timing AESA is advanced with respect to the minimum advance angle, 1ABsEl. In the following step 109, it is determined whether the advance angle X is larger than a predetermined value KESA (5° CA in this embodiment).

Here, when the advance angle X is larger than the predetermined value KESA, the warm-up increase correction coefficient FWL during cold time calculated separately in step 110 is changed to the correction coefficient KFU for high octane fuel.
The fuel injection amount is corrected to increase by RL.

FWL=FWLXKFtJEL Here, the warm-up increase correction coefficient is a correction coefficient when the engine is cold, and continues to increase until the coolant temperature reaches a predetermined value or higher.

Further, in step 109, the advance angle X is set to a predetermined value KESA.
When it is larger than that, no correction is made to the warm-up increase correction coefficient FWL.

Through the above processing, the octane number of the fuel used is estimated based on the advance angle X with respect to the minimum advance angle ABsE2 of MAE S A at the time of ignition set by knocking control. If the octane number of the fuel used is higher than a predetermined value, the warm-up increase coefficient FWL during cold time is corrected so that the fuel injection amount increases.

Therefore, when using high octane fuel, more fuel is delivered during cold periods than when using low octane fuel.

Therefore, since a desired air-fuel ratio can be obtained even when the engine is cold, starting performance and acceleration performance can be improved.

Furthermore, in this embodiment, the octane number is estimated based on the ignition timing set by the knock control, so it is possible to realize an inexpensive electronic control device for the engine by simply adding software without adding any new detection means. .

As another example, in this example, the ignition timing set by the non-king control is
If the advance angle exceeds a predetermined value, the warm-up increase correction coefficient is corrected, but as shown in Figure 4, the larger the advance amount from the minimum advance amount, the larger the warm-up increase correction coefficient. The correction coefficient may be set so as to.

Furthermore, in this example, the minimum advance amount, which is the ignition timing depending on each engine condition when regular fuel is used, is used as the basic ignition timing, and the octane number is estimated based on the advance angle from this basic ignition timing. The maximum advance amount, which is the ignition timing depending on each engine state when high-octane fuel is used, is used as the basic ignition timing, and the octane number may be estimated based on the retardation angle from this basic ignition timing.

In this embodiment, the warm-up increase correction coefficient is increased, but the increase correction coefficient may be increased after startup. Further, both the warm-up increase correction coefficient and the post-start increase correction coefficient may be increased.

〔Effect of the invention〕

The present invention focuses on the characteristic that the ignition timing is advanced as fuel with a higher octane number is used, and estimates the octane number from the ignition timing set by no-two-ton control. Then, the amount of fuel injection during cold time is increased according to the octane number. Therefore, there is an excellent effect of improving starting performance and acceleration performance when cold.

[Brief explanation of the drawing]

Fig. 1 is a diagram corresponding to claims, Fig. 2 is a configuration diagram of an embodiment to which the present invention is applied, Fig. 3 is a flowchart explaining the operation of the embodiment, and Fig. 4 is a basic ignition timing in another embodiment. It is a characteristic diagram of the advance angle amount and correction coefficient from . 10... Knocking detection means, 15... Ignition timing control means, 15... Correction means. Representative Patent Attorney Takashi Okabe (and 1 other person) Figure 2 Figure 3

Claims (1)

[Scope of Claims] Knocking detection means for detecting the occurrence of knocking in the engine; ignition timing control means for controlling ignition timing according to a signal from the knocking detection means; and ignition timing set by the ignition timing control means. 1. An electronically controlled fuel injection device for an engine, comprising: a correction means for increasing the fuel injection amount in a cold state in accordance with the above.