JPS60138241A - Electronically controlled fuel injection device - Google Patents

Abstract

PURPOSE:To prevent an intermittent driving shock from occurring, by making a fuel injection cut so as to be checked at a time when the following conditions are satisfied in time of constant-speed driving control, in case of a device which cuts a flow of fuel injection when a throttle valve is fully closed for more than the specified period of time long and an engine speed is above the specified one. CONSTITUTION:In time of car driving, at a control part 10, when each condition that a signal indicating that 'full close' in a throttle valve opening sensor 20 continues for the specified period (for example, more than 0.5sec) and an engine speed to be secured out of the output of a crank angle sensor 19 is above the specified one (for example, 900r.p.m.) is entirely satisfied, a fuel injection cut command is emitted and thereby fuel injection out of an injector 27 is stopped. And, when a signal indicating that constant-speed driving control is under way is inputted from a constant speed driving controller 28, output of the said fuel injection cut command is checked. With this constitution, an intermittent driving shock due to a repetition of the suspension and resumption of fuel injection in time of driving a downward slope is thus prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an electronically controlled fuel injection system, and particularly to an electronically controlled fuel injection system.
This invention relates to improvements in radial cut control.

Prior Art and Problems In general, in conventional electronically controlled fuel injection systems, the throttle valve is fully closed for a certain period of time, for example 0.5 seconds or more, and when the engine speed is at a certain value, for example 900 rpm or more -C. For example, divination is performed by stopping fuel injection. This is to prevent heating of the catalytic converter, but for this reason, in a system where such an electronically controlled fuel injection device and a so-called constant speed cruise control device coexist, a long descent during constant speed cruise control is required. When riding on a hill, fuel injection is cut and restarted repeatedly at short intervals, resulting in intermittent shocks that make the ride less comfortable.

Fig. 1 is a diagram for explaining this problem, and shows the relationship between the vehicle speed, throttle opening, and electronically controlled fuel injection device fuel (2) injection cut state with respect to the set vehicle speed a of constant speed cruise control. 4) shows an example of this change. On a long downhill slope, it is necessary to fully close the throttle opening in order to maintain the set vehicle speed a, and when the throttle opening is fully open for more than a certain period of time, the electronically controlled fuel injection system detects this with a sensor. to cut fuel injection.

Therefore, the speed of the car decreases quickly. When the traveling vehicle speed becomes slightly lower than the set speed, the throttle opening becomes large again, and when the throttle opening is no longer zero, the electronically controlled fuel injection device resumes fuel injection. When the injection restarts, a shock occurs because torque is suddenly generated. When injection is restarted and the throttle opening gradually increases until the vehicle speed reaches a certain value above the set vehicle speed, the throttle opening decreases again, and if the target speed cannot be maintained, the throttle opening is fully closed. and fuel injection is also cut off. In a system that combines a conventional electronically controlled fuel injection device and a constant speed cruise control device, this cycle of fuel cut and restart is very short, for example, about 10 seconds. For this reason, as mentioned above, the intermittent stiffness (3) is repeated at short intervals, resulting in extremely poor riding comfort.

Purpose of the Invention The present invention has been made to solve such technical problems, and its purpose is to provide a system in which a constant speed cruise control device and an electronic 1i control fuel injection device coexist.
The purpose is to prevent the deterioration of riding comfort on long downhill slopes as described above.

Embodiment of the Invention FIG. 2 is a block diagram of essential parts showing an example of the hardware configuration of a system including an electronically controlled fuel injection device of the present invention. In the figure, reference numeral 10 denotes a control section of an electronically controlled fuel injection system, and a microcomputer 11 and a human interface circuit 13 . ROM 14 for storing programs, etc., RAM 15 for temporarily storing calculation results, etc. - A/I) converter 1 that converts the J'S11 signal into a digital signal
6. It consists of an output interface circuit 17 and a constant voltage power supply 18. The input ink face circuit 13 includes an output signal from a crank angle sensor provided in the distributor 19, which detects the reference position and rotation angle of the crank, and the cylinder position, and the opening degree of the sottle valve. The output signal of the throttle valve degree sensor 20, the output signal of the 02 sensor 21 that detects 1 degree of oxygen in the exhaust pipe,
An output signal from a starter 22 that detects when the engine is starting, an output signal from a vehicle speed sensor 23 that detects the current vehicle speed, and a signal from a constant speed cruise control device 28 indicating that constant speed cruise control is in progress are added. The A/D converter 16 receives the output voltage 7 of the air filter 24, the output signal of an intake temperature sensor 25 that detects the intake air temperature, and the output signal of an aeroflow meter 26 that detects the amount of intake air. Further, the output of the output interface circuit 17 is connected to the injector 27.

The constant speed cruise control device 28 uses a vehicle speed sensor 23 to detect and store the traveling speed of the automobile when a switch generally called a set switch is operated, compares the traveling vehicle speed thereafter with the stored vehicle speed, and controls the throttle using an actuator 29-. By automatically adjusting the valve opening degree, the vehicle speed is controlled to be maintained at a desired value even if the driver does not press the accelerator pedal (5), and its configuration is well known. In the present invention, a signal indicating that constant speed driving control is currently being taken is extracted from the constant speed driving control device 28, and is inputted to the input interface circuit 13 of the electronically controlled fuel injection device as described above. The signal indicating that the constant speed cruise control is in progress can be made using, for example, the output of a self-sustaining circuit in the constant speed cruise control device.

The microcomputer 11 has an A/D converter 16. Various signals from the input interface circuit 13 are read and known calculations are executed, and the signals are sent to the injector 27 via the output interface circuit 17 only at the timing and period determined by the calculation.
It injects more fuel. Since such normal fuel injection control is well known, detailed explanation thereof will be omitted.

In the present invention, in addition to such normal control, fuel injection determination is performed at certain intervals.

FIG. 3 is a flowchart 1 showing an example of a fuel injection determination process, and 81 to S4 represent each step (6). The microcomputer 11 is
A sensor installed in the distributor 19 determines whether the signal (generally the ON signal of the idle contact) continues for a predetermined period of time, e.g. The output signal of the crank angle sensor determines whether the engine speed is a predetermined number, e.g. 90 (lrpm) or less (SL, S2). If the condition is not met, the fuel injection cut determination process ends. do. The above conditions are the same as those conventionally used. If the above-mentioned conditions are satisfied, the microcomputer 11 next determines whether a signal indicating that constant speed driving control is in progress is input from the constant speed driving control device 28 (S3).
.

If the condition is not satisfied, the determination process is terminated, and if the condition is satisfied, fuel injection is performed (S4). Therefore, when driving down a long downhill slope, even if other conditions for fuel injection cut are satisfied, if constant speed driving control is in progress, injection cut is not performed, and fuel injection is repeatedly stopped and restarted. This prevents the shock from intermittent, resulting in improved riding comfort (7). In addition, in this way, fuel 1
If you do not cut the injection, the effectiveness of engine braking will be slightly reduced, but it will not have a negative impact on constant speed control (
Also, although the temperature of the catalytic converter rises a little, it does not reach the point of overheating.

FIG. 4 is a flowchart showing another example of the fuel injection cut determination process, and the difference from FIG. 3 is step S.
5 is added, and when it is determined in step s3 that constant speed driving control is being performed, the fuel injection amount is reduced to a certain value to create a so-called lean combustion state. In this way, the repetition of cutting and restarting fuel injection during constant speed driving control, which was conventionally performed, becomes a repetition of decreasing and returning the fuel injection amount, which can reduce fluctuations in torque by that much, thereby alleviating the shock. . Furthermore, compared to the process shown in FIG. 3, the effectiveness of engine braking can be improved and the temperature rise in the catalytic converter can be reduced. Note that a specific method for reducing the fuel injection amount may be to reduce the injection amount correction coefficient.

(8) FIG. 5 is a flowchart showing yet another example of the fuel injection cut determination process, and 510-315 indicate each step. This embodiment has two fully closed times for the throttle valve, which is one of the conditions for fuel injection cut. When the constant speed driving control is not in progress, the time is 0°5 seconds as in the conventional case, and when the constant speed driving control is in progress, the time is 0°5 seconds. It takes longer, for example, about 1 to 10 seconds. In this way, even if the throttle valve is fully closed, fuel injection is not cut immediately, so it is possible to lengthen the cycle of cutting and restarting fuel injection on long downhill slopes, and the number of shocks can be reduced. This can improve riding comfort.

DETAILED DESCRIPTION OF THE INVENTION As described in detail, the present invention provides an electronically controlled fuel injection device that starts injection of fuel when a throttle valve is fully closed for a predetermined time or more and the engine speed is a predetermined number or more. Since we have provided a means for detecting whether or not the running control is being performed, and a control means that does not cant the fuel injection even if the above conditions are satisfied if the constant speed running control is in progress, ( 9) Fuel injection is cut as before even on long downhill slopes,
The restart is not repeated in short cycles, and it is possible to improve riding comfort.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the problems of the conventional technology, FIG. 2 is a block diagram of essential parts showing an example of the hardware configuration of a system including the electronically controlled fuel injection device of the present invention, and FIGS. The figure shows a flowchart showing different embodiments of the fuel injection cut determination process, in which a microcomputer is shown, 19 is a distributor incorporating a crank angle sensor, 20 is a throttle opening sensor, and 28 is a constant speed running control device. Patent applicant: Fujitsu Ten Ltd. Representative Patent attorney: 1 person (10) outside the five departments of Tamamushiku Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] (1) In an electronically controlled fuel injection system that cuts fuel injection if the throttle valve is fully closed for a predetermined time or longer and the engine speed is a predetermined failure factor, during constant speed driving control. An electronically controlled fuel injection device characterized by comprising means for detecting whether or not the fuel injection is present, and a control means that does not cut the injection of fuel*1 even if the above conditions are satisfied during constant speed running control. . (2. The electronically controlled fuel injection device according to claim 1, wherein the electronically controlled fuel injection device reduces the amount of fuel injected when the condition is satisfied. (3) The electronically controlled fuel injection device according to claim 1. In the electronically controlled fuel injection device according to range 1, the predetermined time for fully closing the throttle valve under the above conditions is less than 1 second when constant speed driving control is not in progress.When constant speed driving control is in progress, it is set to 1 second to 10 seconds. An electronically controlled fuel injection device characterized by: (1)