JPH0580583B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a fuel priority type electronically controlled fuel supply system,
In particular, it relates to improvements in its control method.

Prior Art Conventionally, in this type of fuel supply system, for example, as shown in FIG. 2, by providing means for modifying the command from the accelerator pedal,
One characteristic curve should be selected from a plurality of characteristic curves such as X, Y, Z, etc. set in advance for the stroke (accelerator stroke) S of the accelerator pedal, and should be supplied to the engine according to the characteristic curve. The present applicant's U.S. Patent Application No. 446385 (December 2, 1982) controls the fuel flow rate QF and thus realizes various engine operating characteristics and riding sensations.
It is known from Japan. However, in general, the fully open fuel flow rate QF' (at the engine speed N, the intake air amount of the engine corresponds to the opening degree of the throttle valve. The intake air amount when the throttle valve is fully open is the output air-fuel ratio. (which is the same as the maximum output fuel flow rate of the engine at the rotation speed N) is limited by the engine rotation speed N as shown in Fig. 3, so the change in accelerator stroke S Full fuel flow for
There is a so-called dead zone (shaded area in Figure 3) where QF' does not change, and this dead zone becomes extremely large, especially in the low rotation range, and therefore the effective operating range of the accelerator pedal is extremely narrow. As a result, the axle feeling becomes sensitive and
The effect obtained by setting multiple characteristic curves is no longer fully exhibited, and the fuel flow rate QF supplied to the engine becomes the full-open fuel flow rate QF' in the dead zone, so the accelerator stroke S has a relatively wide range. Since the full-open fuel flow rate QF' is given at full throttle, there are drawbacks such as a decrease in fuel efficiency due to excessive depression of the accelerator pedal.

Purpose In view of the above points, the present invention provides a fuel-priority type electronically controlled fuel supply system for an internal combustion engine having a means for changing the command from the accelerator pedal, by eliminating the dead zone of the accelerator stroke. A fuel-priority type that expands the effective operating range of the accelerator pedal to improve operability of the accelerator pedal, makes full use of the effects obtained by setting multiple characteristic curves, and improves fuel efficiency. The purpose is to provide an electronically controlled fuel supply device.

Overview This purpose is to provide a fuel-priority type electronically controlled fuel supply system for an internal combustion engine that has means for changing the command from the accelerator pedal so that the full fuel flow rate at the engine rotational speed N can be obtained at the maximum accelerator stroke. , the rotational speed N of the engine
The problem is solved by a fuel priority type electronically controlled fuel supply system characterized in that the correspondence between the fuel flow rate to be supplied to the engine and the accelerator stroke is controlled.

Embodiment The present invention will be described below with reference to an embodiment shown in the drawings. In FIG. 4, 10 is an engine; 12 is an engine;
is the throttle valve, 14 is the throttle valve 1
2 actuator, 16 fuel supply mechanism, 18
2 is a fuel injection device, 20 is an accelerator pedal, 22 is a position sensor for the accelerator pedal 20, 24 is a pressure sensor that detects the pressure upstream of the throttle valve 12, and 26 is a pressure sensor that detects the pressure downstream of the throttle valve 12. , 28 is a computer, and 30 is a rotation sensor. The above configuration is the same as that disclosed in, for example, Japanese Patent Laid-Open No. 57-91343, and all control of the fuel flow rate to be supplied to the engine is processed within the computer 28. Then the first
The control system of the present invention relating to the flow rate of fuel to be supplied to the engine will be explained with reference to the flowchart shown in the figure. First, the engine rotation speed N ₁ is detected by the rotation sensor 30, and the full-open fuel flow rate QF' ₁ at this time is calculated, and at the same time α is set such that 0<α<1, and the selected value is selected at this time as shown in FIG. Characteristic curve AB (in case of Fig. 5, same as characteristic curve X of Fig. 2)
The accelerator strokes S ₁ and S ₂ give a full-open fuel flow rate F′ ₁ and a smaller fuel flow rate αQF′ ₁ .
is required. Next, based on the full-open fuel flow rate QF′ ₁ and the accelerator stroke S ₁ , so that the full-open fuel flow rate QF′ ₁ becomes the full-open fuel flow rate QF′ 1 at the maximum accelerator stroke S ₀ .
A correction characteristic curve CD (see FIG. 5) of the fuel flow rate QF with respect to the accelerator stroke S is selected. Thus, the characteristic curve corresponding to the accelerator stroke S
According to _{the ACD} , the engine The fuel flow rate QF to be supplied to the fuel tank is controlled.

Effects of the Invention As described above, according to the present invention, based on the accelerator stroke and the full-open fuel flow rate limited by the engine speed, the full-open fuel flow rate is supplied to the engine at the maximum accelerator stroke. By controlling the desired fuel flow rate, there is no dead zone in the accelerator stroke, and the effective operating range of the accelerator pedal is widened over the entire range, making the accelerator pedal more operable. Therefore, multiple characteristic curves were set. It is extremely effective in that it is possible to fully utilize the effects specific to each characteristic curve obtained by the method, and also to prevent a decrease in fuel efficiency due to over-depression of the accelerator pedal. Since there is a relationship between them as shown in FIG. 6, fuel efficiency can be further reduced by appropriately selecting α.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing the control method of the fuel priority type electronically controlled fuel supply system according to the present invention;
The figure shows the characteristic curve of fuel flow control using the conventional method.
FIG. 3 is a graph showing the relationship between engine speed and full-open fuel flow rate, FIG. 4 is a schematic diagram of a fuel priority type electronically controlled fuel supply system, and FIG. 5 is a graph showing control of fuel flow rate by the device of the present invention. FIG. 6 is a graph showing a general relationship between engine torque and fuel efficiency. 10...engine, 12...throttle valve, 1
4... Actuator, 16... Fuel supply mechanism, 18
...Fuel injection device, 20...Accelerator pedal, 22...
Position sensor, 24, 26...Pressure sensor, 28
...Computer, 30...Rotation sensor.

Claims (1)

[Scope of Claims] 1. A fuel-priority type electronically controlled fuel supply system for an internal combustion engine having means for changing a command from an accelerator pedal, such that a full-open fuel flow rate at the engine rotational speed N is obtained at the maximum accelerator stroke. A fuel priority type electronically controlled fuel supply system characterized in that the correspondence between the fuel flow rate to be supplied to the engine and the accelerator stroke at the rotation speed N of the engine is controlled.