JPS5996446A - Non-synchronous fuel injection method for internal- combustion engine under acceleration - Google Patents

Abstract

PURPOSE:To increase the asynchronous portion of fuel injection amount in the initial period of acceleration by furnishing a circuit to convert the throttle valve degree-of-opening signal into asynchronous form. CONSTITUTION:The degree of opening of a throttle valve is sensed, and the signal obtained therethrough is converted into a one in asynchronous form. The accelerating condition is sensed through the change amount of the asynchronized signal, and if a specific level is exceeded, asynchronous injection shall be carried out. Thereby a larger amount of asynchronous injection can be made in the initial period of acceleration to assure an enhanced accelerating performance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for asynchronous fuel injection during acceleration of an internal combustion engine, and particularly to a method for asynchronous fuel injection during acceleration of an internal combustion engine. The present invention relates to an improvement in an asynchronous fuel injection method during acceleration of an internal combustion engine, in which asynchronous fuel is injected during acceleration when the rate of change of a given throttle valve opening signal exceeds a set value.

2. Description of the Related Art One of the methods for supplying an air-fuel mixture at a predetermined air-fuel ratio to the combustion chamber of an internal combustion engine such as an automobile engine uses an electronically controlled fuel injection device. This means that the fuel 'fr' in the engine
: Injectors for injecting the air are arranged in several engine cylinders in the intake manifold of, for example, an Eva engine, and the valve opening time of the injectors is controlled according to the operating state of the engine 1, for example, the engine rotation speed and the intake pipe pressure. In particular, the air-fuel mixture with a constant Pfr air-fuel ratio is supplied to the engine combustion chamber.

In automobile engines equipped with such electronically controlled fuel injection devices, fuel injection synchronized with steady engine rotation (referred to as synchronous injection) usually results in fuel shortage during acceleration and the air-fuel ratio becomes lean. 1.For example, during acceleration when the rate of change of the throttle valve opening signal given according to the throttle valve opening exceeds a set value, the synchronous injection In addition, so-called asynchronous injection is performed, in which fuel is injected asynchronously regardless of the engine rotation angle.

We are trying to improve acceleration performance.

However, in the past, the relationship between the throttle valve opening and the throttle valve opening signal was linear, and this combined with the slow movement of the throttle valve at the beginning of acceleration, as shown in FIG. 1.

Due to the lack of asynchronous fuel at the beginning of acceleration, the air-fuel ratio temporarily becomes lean, which not only causes problems in acceleration response and drivability during full-throttle racing due to the lack of output shaft torque, but also causes harmful components in the exhaust gas. On the other hand, after acceleration, the amount of asynchronous fuel increases more than necessary, the air-fuel ratio temporarily becomes rich, and the excessive output shaft torque reduces drivability and exhaust gas. The problem was that the purification performance deteriorated.

The present invention was made to solve the problems of the previous dα conventional method, and it is possible to supply a large amount of asynchronous fuel at the beginning of acceleration.
Therefore, it is an overall object of the present invention to provide a method for asynchronous injection during acceleration of an internal combustion engine, which can improve acceleration performance, drivability, exhaust gas purification performance, etc.

The present invention provides a method for asynchronous fuel injection during acceleration of an internal combustion engine, in which asynchronous fuel is injected during acceleration when the rate of change of a throttle valve opening signal given in accordance with the throttle valve opening exceeds a set value. As shown in FIG. 2, the relationship between the throttle valve opening and the throttle valve opening signal is made nonlinear, and the asynchronous injection is controlled using the nonlinearized throttle valve opening signal. All objectives C have been achieved.

With reference to the drawings below, the method of asynchronous fuel injection during acceleration of an internal combustion engine according to the present invention has been adopted. An embodiment of an electronically controlled fuel injection device that senses the amount of intake air for an automobile engine will be described in detail.

As shown in FIG. 3, this embodiment includes an air cleaner 12 for taking in outside air and a flow of intake air i! An air flow meter 14 for detecting Lk, and the air flow meter 14
built into. An intake temperature sensor 16 for detecting the temperature of intake air and a throttle body 18 are provided, and the throttle body 18 is opened and closed in conjunction with an accelerator pedal (not shown) provided in the driver's seat. a throttle valve 20 for controlling the flow rate of intake air;
As shown in FIG. 4, a voltage signal VT proportional to the opening of the front throttle valve 20 (including a potentiometer that outputs R'i and an idle switch) is installed on a shaft that rotates in conjunction with zero. A throttle sensor 22, a surge tank 24 for completely preventing intake air interference, and an intake manifold 26 are installed.An injector 2B for injecting fuel toward each intake boat of the engine 1O, and an exhaust manifold 30 are installed. , a destroyer 32 having a destroyer shaft metal that rotates in conjunction with the rotation of the crankshaft of the engine IO; a crank angle sensor 34 built into the destroyer 32 that outputs a crank angle signal in accordance with the rotation of the destroyer shaft; A water temperature sensor 36 disposed in the cylinder block 10a of the engine IO is used to detect the entire engine cooling water temperature, and during normal operation, the intake air amount determined from the air 70-meter 14 output and the crank angle sensor 34 output The basic injection time is determined according to the engine speed determined from A synchronous injection signal is output to the injector 28 so that the corresponding fuel is injected in synchronization with the engine rotation, while a change in the throttle valve opening signal VTHR', which is a nonlinearized output signal VTHR of the throttle sensor 22. It is comprised of an electronic control unit (hereinafter referred to as ECU) 38 that outputs an asynchronous injection signal to the injector 28 during acceleration when the speed exceeds a set value.

As shown in detail in FIG. 5, the EC03B includes a central processing unit (referred to as CPU) 40 consisting of, for example, a microprocessor for performing various calculation processes, the output of the crank angle sensor 34, and the throttle sensor 22. an input interface 42 for directly receiving digital signals such as the idle switch output, an intake air amount signal output from the air flow meter 14, and the intake mixture sensor 16;
Output intake temperature signal - Output signal VTI (R) of the throttle sensor 22 A digital converter (referred to as A/D converter) 44, a read-only memory (referred to as ROM) 46 for storing all control programs and glaze data, etc., and a read-only memory (referred to as ROM) 46 for temporarily storing calculation data, etc. in the CPU 40. A random access memory (referred to as RAM) 48 and the CP
According to the calculation result in U40, the injector 2
8, etc., and a common bus 52 that connects all of the component devices.

The action will be explained below.

The asynchronous injection in this embodiment is executed according to the throttle sensor output analog-to-digital conversion request interrupt routine as shown in FIG. That is, step 10 is entered with a throttle sensor output analog-to-digital conversion request generated every fixed time period 1, for example, 8 mS;
The output signal of the throttle sensor 2z is converted into a digital signal by the converter 44 and transmitted. Next, the process proceeds to step 102, where a throttle valve opening signal V is determined from the intake dimension i and the throttle sensor output signal V T HR using a non-linear relationship, for example, as shown in FIG.
Find THR”2j. Next, proceed to step 103,
As shown in the following equation, the current throttle/sottle valve opening signal V
The amount of change in the throttle valve opening signal △V T HR', which is determined by subtracting the throttle valve opening signal V T F (R' (OLI)) from the previous cycle, from THR' (NEW) is greater than the set value REF. Determine whether or not.

△VTHR'=VTHR,'(NEW)-'VTHR'
(OLD)-(1) This step 103 is to prevent asynchronous injection from occurring during one deceleration and slight acceleration.

If the determination result of the throttle valve 1030 is positive, that is, during acceleration when the rate of change of the throttle valve opening signal is greater than or equal to the set value, the process proceeds to step 104 and the electronic data is stored in the ROM 46 - for example, as shown in FIG. The relationship between V T HR' and the asynchronous injection lid ASYTAU is expressed as follows: Throttle valve opening signal - bow change amount △VT) Find the asynchronous injection lid ASYTA, U.Also, in order to increase the asynchronous injection amount at the beginning of acceleration, it is possible to change the characteristics as shown in Fig. 8, but in this case,
Since the number of asynchronous injections itself remains unchanged, sufficient effects may not always be obtained.

After step 104, the process proceeds to step 105, where the asynchronous injection lid A, 5YTAU is set to the minimum flow rate of 1TAU of the injector.
It is determined whether the value is equal to or greater than REF. This step 10
5 is the minimum flow rate of the injector for one fuel injection f
This is to ensure accuracy in controlling the amount of fuel injection by setting it to F or more.

If the determination result in step 105 is positive, the process proceeds to step 106, where the asynchronous injection amount A S Y T A U
(9) Execute asynchronous one-shot by After step 106 is completed, or if the results of the previous steps 103 and 105 are negative, this routine ends.

In this embodiment, since the output signal of the throttle sensor 22 is made non-linear in the ECU 3B, the throttle sensor 22 is not linearized as in the conventional case. can be used, and the device can be constructed at low cost. Further, the throttle sensor is easier to adjust and manufacture than when the output signal of the throttle sensor itself has nonlinear characteristics.

However, the method of completely nonlinearizing the throttle valve opening signal is not limited to this, and the method for making the throttle valve opening signal fully nonlinear is as follows.
It is also possible to make the relationship with R non-linear as shown in FIG. 9, for example. In this case, the program within the ECU 38 is simplified.

Although the previous embodiment was applied to an automobile engine equipped with an electronically controlled fuel injection device that senses the amount of intake air, the scope of application of the present invention is not limited thereto. It is clear that the invention can be similarly applied to a general internal combustion engine equipped with other electronically controlled fuel injection devices.

As explained above, according to the present invention, more asynchronous fuel can be injected at the beginning of acceleration, and acceleration performance can be improved. Further, since the necessary fuel is supplied when necessary, it has excellent effects such as improved drivability and exhaust gas purification performance.

[Brief explanation of drawings]

FIG. 1 shows a conventional example. FIG. 2 is a diagram showing an example of the relationship between the throttle valve opening and the state of change in engine output shaft torque; FIG. A sectional view 2 including a partial block diagram showing the configuration of an embodiment of an intake air amount sensing type electronically controlled fuel injection device for an automobile engine in which the method of asynchronous fuel injection during acceleration of an internal combustion engine according to the present invention is adopted. FIG. 4 is a diagram showing the output characteristics of the throttle sensor used in the embodiment, and FIG. 5 is a diagram showing the output characteristics of the throttle sensor used in the embodiment. Similarly, a block diagram showing the configuration of the electronic control unit,
FIG. 6 is a flowchart showing a throttle sensor output analog-to-digital conversion request interrupt routine for performing asynchronous injection, and FIG. FIG. 8 is a diagram showing an example of the relationship between the output and the throttle valve opening signal, and FIG. 9 is a diagram showing an example of the relationship between the amount of change in the throttle valve opening signal and the asynchronous injection amount. FIG. 7 is a diagram showing an example of the relationship between the throttle valve opening of the throttle sensor and the throttle sensor output signal in a modification of the invention. 10...Engine, 14...Air flow meter 20
°... Throttle valve-22... Throttle sensor, 28... Injector, 32... Test review, 34... Crank angle sensor 38... Electronic control unit. Agent Takaya Ron (and 1 other person) - Taikou → Norito Gaeya Shunyaji

Claims (1)

[Claims] (1) In an asynchronous fuel injection method during acceleration of an internal combustion engine, in which asynchronous fuel is injected during acceleration when the rate of change of a throttle valve opening signal given in accordance with the throttle valve opening exceeds a set value, 1. A method for asynchronous fuel injection during acceleration of an internal combustion engine, characterized in that the relationship between the throttle valve opening and the throttle valve opening signal is made non-linear so that a large amount of asynchronous fuel is injected at the beginning of acceleration.