JPS5970841A - Fuel feeder for motorcycle engine - Google Patents

Abstract

PURPOSE:To obtain a good acceleration characteristic, by determining an acceleration fuel amount while applying a rotary speed as the main parameter in the case of a motorcycle engine. CONSTITUTION:Output signals from an engine temperature sensor 24 and an air flow meter 18 are input to an input/output circuit 36 of a control circuit 30 and converted into digital values. Further, an output pulse is input at each 180 deg. turn of a crank angle from a crank angle sensor 22, and a fuel injection pulse controlling an injector 60 is output in accordance with said output pulse. Further outputs of a throttle switch 22 and a starter switch 40 are input as signals of one bit. In accordance with these input signals, a computer 32 outputs both the control signal of a fuel pump to a pump 54 by the execution of a program and the fuel injection pulse to the injector 60 in response to the output pulse of the crank angle sensor. An injector pulse signal (B) is applied to the air flow meter, and an acceleration injection pulse A.TA is generated in accordance with detection of an acceleration condition.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a fuel supply system for a motorcycle engine.

[Background of the invention]

Digital computers are used to disinfect the fuel system of automobile engines. This automotive engine fuel supply system uses a digital meter to detect changes in intake air.
When the amount of change ΔQA in the intake air tank is larger than a predetermined value, fuel determined according to the amount of change ΔQA is injected. Hereinafter, this injection will be referred to as acceleration correction injection. Generally, fuel injection is performed in synchronization with engine rotation. Hereinafter, this injection will be referred to as normal injection. However, if the nitrogen intake into the engine suddenly increases, it is necessary to suddenly increase the amount of fuel supplied, so fuel is injected at a different timing from the regular injection. This is hereinafter referred to as accelerated injection. The fuel supply amount for this accelerated injection has generally been determined based on the amount of change ΔQA in the intake air.

Recently, there has been a demand for controlling motorcycle engines using digital computers. Accelerated injection is necessary to control a motorcycle engine, just as in a car. When the acceleration state is detected, the same 4f as a car! It was found that sufficient acceleration characteristics could not be obtained when the amount of supplied fuel was used as a secondary parameter using the change ΔQA of the intake nitrogen shield as a main parameter.

[Purpose of the invention]

An object of the present invention is to provide a fuel supply system for a motorcycle engine that provides good acceleration characteristics.

[Summary of the invention]

As mentioned above, when the acceleration fuel supply amount is determined as the main parameter of change in intake air amount ΔQAk, we investigated the cause of the problem in which good acceleration characteristics cannot be obtained. It was found that the rate of change in throttle opening relative to the accelerator operation value was very large. Therefore, it was found that the rate of change in intake air that increases with acceleration operation is determined by the structure of the intake pipe rather than depending on the amount of throttle operation.

It has been found that the change in intake air ΔQ and A when the motorcycle is accelerating is approximately the same as the change in intake air when the throttle is fully opened at once. In other words, the amount of change does not depend much on the amount of operation of the accelerator, and is a substantially constant amount of change.

Therefore, in the present invention, the acceleration fuel if is determined using the rotational speed N of the motorcycle engine as a main parameter. Further, as a result of experiments, it was confirmed that good acceleration characteristics could be obtained by determining the acceleration fuel using the engine rotational speed N as the main parameter.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a system diagram of a fuel supply device for a four-stroke motorcycle engine. Fireflies between the walls are supplied from the air cleaner 12 to the engine 16 at 1 lilJ fMl by the throttle 14 and are detected by a thermal air flow meter 18 provided at the outlet of the air cleaner 12. Also throttle t4
A throttle switch 20 is provided to detect the fully open state (minimum opening state) of the throttle. The engine is also provided with a crank angle sensor 22 that outputs a pulse every 180 rotations of the crank angle, and an engine temperature sensor 24, the outputs of which are input manually to a control system 30 consisting of a digital computer.

The fuel in the fuel tank 52 is pressurized by the pump 54,
The fuel is supplied to the injector 60 via the filter 56 and the damper 58, and the output pulse from the control circuit 30 supplies fuel according to the valve opening time of the injector.

FIG. 2 is a detailed block diagram of the neighbor control circuit 30. A digital computer 32 has built-in RAM and memory, and is connected to a ROM 34 and an input/output circuit 36 via a data bus 38. The output signals of the above-mentioned engine temperature sensor 24 and air flow meter 18 are inputted to the input/output circuit 36 and converted into digital signals. Further, an output pulse is manually generated from the crank angle sensor 22 every 180 degree rotation of the crank angle, and a fuel injection pulse for controlling the injector 60 is output in response to this pulse. 1 more
The outputs of the throttle switch 22 and starter switch 40 are input as bit signals.

In response to the above input signal, the computer 32 executes the program to output a fuel pump control signal to the pump 54, and outputs a fuel injection pulse to the injector io in response to the crank angle sensor output pulse as described above.

FIG. 3 is an explanatory diagram of the operation of the control circuit. (a) shows the output of the air flow meter. (b) shows the pulse signal applied to the injector, and the diagonal line shows the accelerated injection pulse. (c) shows the cutting edge of the crank angle sensor 24. In this embodiment, the crank angle sensor 22 outputs a pulse every 180 degree rotation of the crank angle.

Among the fuel injection pulses shown in (b), the normal injection pulse is (
C) It is created in synchronization with the crank angle sensor output.

On the other hand, an accelerated injection pulse shown by diagonal lines is generated in response to detection of an acceleration state.

FIG. 4 is a flowchart for detecting the acceleration state and calculating the acceleration injection amount, which is executed every fixed period of time, for example, every 10 m5 (a). In step 12, the output QA of the air 70-sensor is taken in and held in RAM, and it is compared with the outputs Q and A of the air flow meter held during the previous execution, and the difference Δ is calculated.
Calculate Q and A. Further, the engine speed N is calculated by taking the period from a counter that counts all pulse intervals of the crank angle sensor and calculating its reciprocal. This counter is provided in the input/output circuit, and each time the crank angle pulse is input, the count value is held in a register, the counter is reset, and the clock starts counting again. In step 14, it is determined whether the difference ΔQA is larger than a certain value, and the acceleration state is determined. If it is determined that there is an acceleration, the process moves to step 16, but if not, the execution of this program ends. In step 16, an acceleration coefficient A corresponding to the engine speed N is searched from a lookup table stored in advance using the engine speed UN as a parameter. This m-speed coefficient A indicates the rate of acceleration fuel increase.

In step 18, the injection amount TI of the previous regular injection is successively determined,
Multiply that value by acceleration coefficient A. That is, A −T I f!
Calculate cfit. At the same time as this total of 7Hiη is set to the input/output circuit, a special activation is applied to perform accelerated injection. As a result of this activation, a fuel injection pulse is output in the same way as when the crank angle sensor's blade pulse is input, and its pulse width becomes 1 direct A-TI as measured above.

FIG. 5 is a flowchart for calculating the normal injection pulse width, which is executed every fixed period of time, for example, every 20 m8eO. In step 22, the manual input QA and N input in the flowchart of FIG.
p′! ! -Calculate. At this time, the formula % Formula % (11 Next, in step 24, the engine temperature is taken in from the sensor 24, and based on this value, the correction coefficient K is searched from the lookup table.In step 26, the fuel injection amount T At the same time, the value is recorded in the RAM and used in step 18 of the car 4 diagram.Furthermore, this d1 calculation result is '1'.
Outputs I to the input/output circuit. As a result, this Nl' calculation result TI is calculated at the timing of the 1B sword pulse of the crank angle sensor.
A pulse with a pulse width corresponding to is applied to the injector,
Fuel is supplied.

[Effects of Implementation VII]

In this embodiment, the acceleration is determined by a program that is executed in short cycles (10 m), so responsiveness is good. Furthermore, since this flowchart is executed at regular intervals (10 "old system"), it is easy to detect the rate of change ΔQA of the intake air.Furthermore, with the engine rotation speed as a parameter, the Toguchi coupling coefficient is stored in the ROM. Since it is determined by searching from an up-table, even coefficients that change discontinuously can be selected arbitrarily, and arbitrary characteristics can be determined.This improves controllability.Also, the regular injection amount TI Since the acceleration fuel is determined by this acceleration coefficient A, the calculation is simple.In this example, the acceleration fuel was found from A and '1', but it can also be calculated by multiplying A and TP. Regulatory (goods) characteristics are obtained.

[Second Example] In the above example, an acceleration coefficient was determined based on the engine rotational speed N, and the acceleration injection amount was determined from this coefficient A and the normal injection amount. However, engine speed iN and intake air amount Q,
The accelerated injection amount can also be determined from A. The example is the fourth example.
This is shown at step 52 in the figure. This embodiment therefore performs step 52 in place of steps 16 and 18 of the flowchart of FIG.

The optimal acceleration injection amount is determined experimentally in advance using N and QA as parameters, and the value is stored in the ROM. If it is determined in step 14 that the acceleration state is present, step 1
4 to step 52.

In this step 52, the accelerated injection amount is searched and determined according to QA and N. This search result is set to the input/output circuit 36 in step 20, and is then used to start the acceleration injection! Multiply 111I. As a result, accelerated injection is performed at the value set in the input/output circuit.

[Effects of the second embodiment] In the second embodiment, the accelerated injection amount is determined by table search, so the processing time is short. Further, FIG. 4 shows a business luck processing routine, and by shortening the processing time of each step, the effect of reducing the total load on the p-calculator is significant. Furthermore, since the acceleration state determination step is provided in the cylinder speed routine and the sensor output capture routine, the acceleration response is improved.

〔Effect of the invention〕

As explained above, in the present invention, since the acceleration fuel amount is determined using the engine rotational speed KN as the main parameter, good acceleration characteristics can be obtained. It should be noted that substantially similar characteristics can be obtained with data of the period which is the reciprocal of the engine rotational speed N. In this application, period data can also be treated as data N representing the engine rotational speed.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention, FIG. 2 is a detailed block diagram of the control circuit shown in FIG. 1, FIG. 3 is an operation explanatory diagram, FIG. 4 is a flowchart showing an accelerated injection program, FIG. 5 is a flowchart showing the regular injection program. 18... Air flow meter, 20... Throttle switch, 22... Crank angle sensor, 24... Temperature i
Sey No. 1 I21 -240-

Claims (1)

[Claims] 1. A sensor that detects the operating state of the engine, a digital computer that calculates the fuel supply amount based on the sensor output, and a fuel supply means that supplies fuel based on the output of the digital computer, which supplies fuel to the engine according to the operating state of the engine. The digital computer has a function to use the acceleration state from the sensor output, a function to determine the acceleration fuel supply amount based on the engine speed when the acceleration state is detected, and a function to determine the acceleration fuel supply amount based on the engine speed when the acceleration state is detected. A fuel supply device for a motorcycle engine, characterized by having a function of instructing a fuel supply means to immediately supply acceleration fuel.