JPS6062637A - Fuel injection device of engine - Google Patents

Abstract

PURPOSE:To facilitate exchange of a fuel injection valve and thereby make an injection amount control device useable for various purposes by evaluating a basic fuel injection amount in responce to the amount of intake air and then evaluating the width of an injection pulse. CONSTITUTION:A fuel injection device includes a signal detecting means 19 for detecting an intake air amount supplied to an engine 1 or a signal associated therewith and an arithmetic operation means 21 for evaluating the injection amount of fuel supplied to the engine 1 in responce to the output of the signal detecting means 19. Further, it includes an injection valve driving signal arithmetic operation means 22 operating an injection valve driving signal in responce to the fuel injection amount from the fuel injection amount airthmetic operation means 21, and a fuel injection valve 8 driven in responce to the injection valve driving signal from the injection valve driving signal arithmetic operation means 22. During engine operation, a fuel injection amount in responce to an intake air amount is evaluated, and thereafter an injection valve driving signal (fuel injection time) corresponding to a fuel injection valve being used is evaluated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel injection device for an engine, and more particularly to an improvement of a fuel injection ffi Ill ti11 device.

(Prior Art) Conventionally, as a fuel injection device for this type of engine, for example, pulse width data of many injection pulses (basic fuel injection time data) is used to input intake air amount or related signals, such as intake negative pressure and engine The pulse width of the injection pulse corresponding to the intake air amount is inputted and memorized in advance according to the engine operating state determined by the rotation speed, and when the engine is running, the pulse width of the injection pulse corresponding to the intake air amount is immediately calculated from the pulse width data of the injection pulse. It reads out the relevant signals and outputs them as injection valve drive signals to the fuel injection valves (thereby adjusting the amount of fuel injection supplied to the engine and adjusting the air-fuel ratio of the mixture supplied to the engine). There are known devices that adjust and control the air-fuel ratio to a set air-fuel ratio (for example, Japanese Patent Application Laid-Open No. 57-1431
(Refer to Publication No. 35, etc.) By the way, when fuel injection valves of different types do not inject the same amount of fuel even if they receive injection pulses with the same pulse width, the injection valve drive signal (injection pulse) The characteristics of the fuel injection port are different for each type.

Therefore, in the conventional system described above, when replacing a fuel injector with one with different injection quantity characteristics as necessary, the pulse width data of the injection pulse corresponding to that fuel injector must be input and stored from the beginning each time. It needed to be fixed, and the work was troublesome and cost me $41'! The disadvantage is that the fuel injection amount control device is less versatile than the 10% valve.

(Objective of the Invention) The object of the present invention is to divide the process from detection of the intake air amount or a signal related thereto to generation of an injection valve drive signal according to the intake air amount into two stages. The basic fuel injection amount is calculated according to the intake air amount based on the signal.
Next, based on this, the fuel injection time (pulse width of the injection pulse) that is primarily determined for the fuel injection valve to be used is calculated, which makes it easier when replacing the fuel injection valve with one with different injection amount characteristics. In this way, only the fuel injection time characteristic with respect to the fuel injection amount at the latter stage of the injection valve drive signal generation process needs to be changed again, thereby making it possible to perform the work associated with replacing the fuel injector with one having a different injection amount characteristic. The object of the present invention is to reduce and simplify the costs and thereby improve the versatility of the fuel injection control device for various fuel injection valves.

(Structure of the Invention) In order to achieve the above object, the structure of the present invention is as shown in FIG. 1, as shown in FIG. , a fuel injection amount calculation means 21 which calculates the fuel injection m to be supplied to the engine 1 according to the output of the signal detection means; It consists of an injection valve drive signal calculation means 22 that calculates a valve drive signal, and a fuel injection valve 8 that is driven according to the injection valve drive signal of the injection valve drive signal calculation means 22, and when the engine is running,
First, the fuel f'31 (injector m) corresponding to the intake air m is calculated, and then the injector drive signal (fuel injection time) corresponding to the fuel injector used is calculated.

(Effects of the Invention) Therefore, according to the present invention, the injection valve drive signal to the fuel injection valve is calculated based on the fuel injection amount calculated according to the intake air amount. When replacing the injection amount characteristics, it is only necessary to change the fuel injection time characteristics for the fuel injection amount of the fuel injection valve, that is, the calculation contents of the injection valve drive signal calculation means, and the work associated with the replacement can be minimized and This can be easily done, and therefore the versatility of the fuel injection amount control device can be improved.

(Example) Hereinafter, an example as a specific example of the technical means of the present invention will be described in detail based on the drawings.

In FIG. 2, 1 is an engine, 2 is a combustion chamber formed by a cylinder 3 formed in the engine 1, and a piston 4 slidably inserted into the cylinder 3, and 5 is an air cleaner at one end. 6 to the atmosphere, and the other end to the combustion chamber 2 for supplying intake air to the combustion chamber 2.In the intake passage 5, there is provided a l for controlling the amount of intake air.
l′! A throttle valve 1' and a fuel injection valve 8 for injecting and supplying fuel are provided upstream of the throttle valve 7, respectively. Further, reference numeral 9 denotes an exhaust passage with one end opening into the combustion chamber 2 and the other end opening into the atmosphere for discharging exhaust gas from the combustion chamber 2. A device 10 is provided. Note that 11 is an intake valve provided at the opening of the intake passage 5 to the combustion chamber 2;
2 is an exhaust valve provided at the frontage of the exhaust passage 9 to the combustion chamber 2, and 13 is an intake heating position a for heating the downstream side of the throttle valve 7 in the intake passage 5 with engine cooling water.

Further, 14 is a throttle opening sensor that detects the opening of the throttle valve 7, 13 is a negative pressure sensor that detects the intake negative pressure downstream of the throttle valve 7 in the intake passage 5, and 16 is the cooling water temperature of the intake air heating device 13. Cooling water temperature sensor that detects 1
7 is an air-fuel ratio sensor consisting of a 02 sensor that detects the air-fuel ratio based on 1 degree of oxygen lIr in the exhaust gas upstream of the catalyst device 10 in the exhaust passage 9; 18 is an engine rotation speed sensor that detects the rotation speed of the engine 1; The negative pressure sensor 15 and the engine speed sensor 18 constitute a signal detection means 19 configured to detect a signal related to the amount of intake air supplied to the engine 1.

Further, the detection signals of the respective sensors 14 to 18 are transmitted to the fuel injection valve 8.
are respectively input to a controller 2o that drives and controls the .

Inside the controller 1-20, as shown in FIG. 4, a large number of fuel injection data corresponding to the intake air amount are input and stored in correspondence with the engine speed and the intake negative pressure. In addition, as shown in FIG. 5, the fuel injection time (pulse width of the injection pulse) characteristic of the fuel injection valve 8, which is temporarily determined with respect to the fuel injection rJJu, is input and stored in advance.

Next, the operation of the controller 2o will be explained based on the flowchart of FIG. First, after starting, all values in the controller 20 are initialized in the m1 step s1, the current intake negative pressure is read out based on the negative pressure signal of the negative pressure sensor 15 in the second step S2, and the current intake negative pressure is read out in the third step S2. J5 is in S3 and the current engine speed is not read out based on the output of the rotation speed sensor 18.

Next, in a fourth step s4, a fuel injection amount corresponding to the current intake air m is calculated from the fuel injection m data based on the current intake negative pressure and engine rotation speed, and then,
In the fifth step S5, the pulse width of the injection pulse to be outputted to the fuel injection valve 8 is calculated from the fuel injection time characteristic of the fuel injection valve 8 based on the fuel injection value (2) read above.

Then, in the sixth step S6, the injection timing of the injection pulse (for example, the piston top dead center) is met, and in the seventh step $7, the injection pulse with the above-mentioned pulse width is used as the injection valve drive signal to fuel 1'! 1 injection Q] is output to the valve 8, drives the fuel injection valve 8, and returns.

Therefore, rJJffl for fuel in the fourth step S4
By calculating the fuel injection amount according to the intake air amount from the data, the engine 1 A fuel injection amount calculation means 21 is configured to calculate the amount of fuel injection to be supplied to the fuel injection amount.

Also, by calculating the pulse width of the injection pulse (injector drive signal) according to the fuel injection amount in the fifth step S5,
An injection valve drive signal calculation means 2 that calculates an injection valve drive signal according to the fuel injection m of the fuel injection m calculation means 21.
2.

Therefore, in the above embodiment, when replacing the fuel injection valve 8 with one having a different fuel injection amount characteristic with respect to the injection pulse, there is no need to newly store the fuel injection amount data in FIG. If only the fuel injection time (pulse width) characteristics of the fuel injection valve 8 shown in FIG. 5 are changed to match the fuel injection time characteristics of the replaced fuel injection valve, the combustion injection m from the replaced fuel injection valve can be Since the amount of intake air m can be adjusted to an appropriate amount according to the amount of intake air m, the work associated with replacing the fuel injection valve can be minimized and made easy, thereby reducing fuel injection! The versatility of the 8m control device can be greatly improved.

In the above embodiment, the fuel injection amount corresponding to the intake air amount was calculated according to the engine operating state determined by the intake negative pressure signal of the negative pressure sensor 15 and the engine rotation speed signal of the rotation speed sensor 18, etc. Of course, the fuel injection m may be calculated according to the intake air m by providing a signal detection means that directly detects the intake air.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIGS. 2 to 5 show embodiments of the present invention, FIG. 2 is an overall schematic configuration diagram, and FIG. 3 is a flowchart diagram showing the operation of the controller. FIGS. 4 and 5 are diagrams showing the memory contents of controller 1-0-, respectively. DESCRIPTION OF SYMBOLS 1... Engine, 8... Fuel injection valve, 19... Signal detection means, 21... Fuel injection m calculation means, 22...
- Injection valve drive signal calculation means. Applicant: Toyo Kogyo Co., Ltd. 4th cause, 5th cause! -γ Kenoto 0 negative “Physical size 1i Figure 3

Claims (1)

[Claims] (1) Signal detection means for detecting the amount of intake air supplied to the engine or a signal related thereto, and fuel injection amount calculation means for calculating the amount of fuel injection rJJ supplied to the engine according to the output of the signal detection means , an injection valve drive 4r3@ calculation means for calculating an injection valve drive signal according to the fuel injection amount of the fuel injection rJJ amount calculation means; 1. A fuel injection device for an engine, comprising a fuel injection valve.