JPH08296468A - Engine fuel ignition control method - Google Patents

Abstract

(57) [Abstract] [Purpose] Optimize the fuel ignition control method that controls the ignition command to the engine by the accelerator signal at the time of deceleration of the vehicle in the engine that uses alcohol as fuel, and eliminates the emission of unburned fuel (EN) An improvement that prevents deterioration of the function of a catalyst converter and extends the life of a spark plug. In an engine fuel ignition control method in which fuel is supplied by an accelerator operation and an ignition command is variably output to change a rotation speed, an output, and a torque, an accelerator signal is below a predetermined amount. At the same time, the ignition signal to the engine is stopped, and when the engine rotation speed drops to a predetermined amount, the ignition command is output again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel ignition control system for an engine, and more particularly to an engine using an alcohol as a fuel, and a fuel ignition system for controlling an ignition command to the engine by an accelerator signal during deceleration of the vehicle. Regarding control method.

[0002]

2. Description of the Related Art A fuel ignition control device and a fuel injection device used in a conventional alcohol engine will be described.
FIG. 3 shows an overall system diagram of the fuel ignition control device and the fuel injection device. In FIG. 3, the fuel supply circuit to the fuel injection nozzle 14 sucks alcohol fuel from the fuel tank 10 by the feed pump 11, and the fuel filter 1
It is supplied to the fuel injection pump 13 through the fuel cell 2. The fuel that has entered the fuel injection pump 13 is pressurized by a plunger (not shown), and an appropriate amount of fuel is injected into the combustion chamber at high pressure from a fuel injection nozzle 14 provided in each cylinder.
The remaining fuel returns to the fuel tank. The fuel injection pump 13 is a column type and is composed of a pump body 13B and a governor 13C. The pump main body 13B has a pressure feeding mechanism including a plunger and a cam shaft (not shown) for increasing the pressure of the fuel and feeding it to the injection pipe, and a mechanism for adjusting the amount of pressure feeding (injection amount). The adjusting mechanism determines the amount (injection amount) to be pumped in the moving chamber of the rack 13A. The governor 13C is mechanically connected to the rack 13A of the injection amount adjusting mechanism of the pump body, and controls the injection amount according to the rotation speed and the load. The governor is also connected to an accelerator 30 that increases or decreases the engine speed. The ignition system is provided with a relay circuit device 35, an ignition coil 21, and an ignition plug 22 for each cylinder. The relay circuit device 35 supplies a primary current by a signal from the ignition system controller 34, the ignition coil 21 generates a high voltage in the primary side coil and the secondary side coil, and the ignition plug 22 outputs the high voltage in the electrode. It discharges between and ignites the mixture with electric sparks.
The ignition system controller 34 includes an accelerator sensor 31, an engine camshaft cylinder determination sensor 32, a crankshaft rotation angle, a rotation speed sensor 33, and a rack sensor 3.
Ignition timing is controlled by each signal from 6.

[0003]

In the ignition timing control method having the above-described structure, in the fuel injection pump 13 of the alcohol engine and the device for electronically controlling the ignition timing, which has the following problems, when the vehicle is decelerated, for example, the accelerator is fully opened. In order to improve the life of the spark plug 22 in the fuel non-injection state when shifting from the full load to the accelerator off low idle, a control method of stopping the ignition can be considered, but the output of the accelerator sensor 31 due to the accelerator off is Although it immediately becomes zero and the ignition is immediately stopped by the control device, the fuel does not immediately become non-injection due to the delay in the return of the rack of the injection amount adjusting mechanism (not shown) of the fuel injection pump 13. Therefore, unburned fuel is discharged. The discharged unburned fuel enters a catalyst converter (not shown), and there is a problem that the fuel burns at the inlet portion and the function is deteriorated or stopped such as damage to the catalyst converter. When the accelerator is turned off to stop the ignition and then to the low idle, it is necessary to optimize the setting of the ignition restart timing. That is, if the ignition restart timing is advanced, the ignition stop period is shortened, and the life of the spark plug 22 cannot be improved. If it is too late, the fuel injection amount comes first and unburned fuel is discharged. If it is too late, the engine will stop.

The present invention focuses on the above-mentioned conventional problems, and relates to a fuel ignition control device for an engine, and more particularly to an engine using an alcohol as fuel, and an ignition command to the engine is issued by an accelerator signal during deceleration of the vehicle. It is an object of the present invention to provide an improved fuel ignition control method for controlling, eliminating the discharge of unburned fuel, preventing the deterioration of the function of the catalyst converter, and improving the life of the spark plug.

[0005]

In order to achieve the above object, in the first invention of the engine fuel ignition control method of the present invention, the fuel is supplied by the accelerator operation, and
In the engine fuel ignition control method, in which the ignition command is variably output to change the rotation speed, output, and torque, when the accelerator signal falls below a predetermined amount, the ignition signal to the engine is stopped and the engine rotation is stopped. When the speed drops to a predetermined amount, the ignition command is output again.

In the second invention, which is mainly based on the first invention, the ignition stop command to the engine is output after a predetermined time elapses from the time when the accelerator signal becomes zero or after the rack position becomes a predetermined amount or less. thing.

In the third invention mainly composed of the first invention or the second invention, the fuel is an alcohol.

According to a fourth aspect of the invention, which is mainly based on the first or second aspect, the accelerator signal of a predetermined amount or less is zero.

[0009]

According to the above control method, when the engine is an engine that uses an alcohol, the fuel of the engine is decelerated when the vehicle depresses the accelerator while the vehicle is running and the vehicle decelerates to a low idle. The injection amount shifts to low idle through the following process. That is, when the accelerator is turned off, the rack amount becomes zero from the high speed FULL state through the non-injection start region. After that, the zero state of the rack continues as the rotation speed decreases, and when the rotation speed becomes equal to or lower than a predetermined value, the zero state of the rack ends, and then the injection starts again through the end region of no injection to reach low idle. In this process, the engine is stopped and restarted by the following control. First, the ignition stop command is output when the accelerator is turned off and the accelerator signal becomes less than a predetermined value. Next, the ignition restart command decreases the engine speed due to the accelerator off,
The output is controlled when the rotational speed falls below a predetermined amount.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A fuel ignition control device for an alcohol engine and a fuel ignition control method for a fuel injection device according to the present invention will be described below with reference to the drawings. Note that the configurations of the engine fuel ignition control device and the fuel injection device are the same as those in FIG.

To facilitate understanding of the present invention, first, the relationship between the fuel injection amount (rack position) and the fuel ignition when the engine speed changes from high speed to low speed will be described with reference to FIG.
At the same time, how the output of the accelerator sensor and each characteristic change with time will be sequentially described from FIG. 5 to FIG. In FIG. 4, the vertical axis represents the rack position and the horizontal axis represents the engine rotation speed. The upper solid line P in the figure indicates the full load set of the injection pump, that is, the rack position FULL (injection amount FU at each rotation speed).
LL), the solid line Q on the right side is the over-rotation prevention governor 13C.
Shows high speed control by. Further, the lower solid line S in the figure shows a non-injection line in which fuel is not supplied. A hatching range S indicates a non-injection region where fuel is not supplied. An alternate long and short dash line R indicates a load line of the vehicle, and indicates that the rated point A and the low idle point F are in balance. Next, the operation will be described. 4 and FIG. 5 to FIG. 9 will be described with reference to FIG. 4 and FIGS. 5 to 9 in which the vehicle travel accelerator is depressed, that is, the accelerator is turned off from point A to decelerate to the low idle F. 5 to 9, the horizontal axis represents time in each figure, the vertical axis represents output of the accelerator sensor in FIG. 5, FIG. 6 is rotational speed, FIG. 7 is rack position, FIG. 8 is injection amount, and FIG. 9 is ignition. 4, reference numeral Ta corresponds to point A in FIG. 4, Tb corresponds to point B, and Tf corresponds to point F, respectively. A
When the accelerator is turned off at the point (Ta), the rack reaches a point B (Tb) due to a delay. Fuel is injected from point A (Ta) to point B (Tb). This state is shown in Figure 8.
The injection amount is indicated by the hatched region Z. Point B (Tb) is the start point of no injection, and thereafter B (Tb) → C (T
c) → D (Td) → E (Te) transitions without injection. Point C (Tc) is a point where ignition is stopped. Point D
(Td) is the point at which ignition is restarted, and therefore point C
From (Tc) to point D (Td), fuel is not injected and ignition is stopped. The point E (Te) is the end point of no injection on the low speed side, and the injection starts after the point E (Te). Point F (T
f) is the low idle point. Next, a method of stopping ignition and restarting ignition will be described. First, the ignition is stopped to turn off the accelerator, and the ignition command to the engine is output by a timer after a predetermined time has elapsed from when the accelerator signal becomes zero, and by the method after the rack position becomes zero. There is. The former method of outputting by a timer after a predetermined time has elapsed is shown by a time T1 from Ta to Tc in FIG. (Step 4 in the flow chart of FIG. 1) The latter method of outputting after the rack position reaches zero is Tc of FIG.
The time point C is shown. (Float chart step 3 in FIG. 2) Next, in the method for restarting ignition, the accelerator is turned off at Ta in FIG.
At 1, ignition is restarted at Td as shown in FIG. (Step 8 of the chart of FIG. 1 and the flowchart of FIG. 2)
Chart chart Step 7)

FIG. 1 is a flow chart of a fuel ignition control method (No. 1) for an engine according to the present invention. This ignition control method (No. 1) is a flow chart in which an ignition stop command to the engine is output after a predetermined time elapses from the time when the accelerator signal becomes zero, and will be sequentially described from step 1 to step 11. In step 1, it is determined whether or not the engine rotation speed is higher than a predetermined amount. When the amount is larger than the predetermined amount, the process proceeds to step 2, and when it is smaller, the process proceeds to step 10.
Proceed to. The predetermined amount of engine rotation speed is set from the test result for each reference engine from the beginning, and is stored in the spark plug system controller 34 of FIG. In step 2, it is judged whether or not the accelerator sensor output is zero. That is, as shown in FIG. 6, when the accelerator is turned off to shift to deceleration,
It is determined whether or not the accelerator sensor output is zero. When the accelerator sensor output is zero, the process proceeds to step 3, and when the accelerator sensor output is not zero, the process returns to step 1. In step 3, ignition stop control is started, and timer T starts time measurement. In step 4, the set timer time T
It is determined whether 1 is less than or equal to the actually measured timer time T.
In the following cases, the process proceeds to step 5, and when it exceeds, the process proceeds to step 6. The set timer time T1 is the same as the time to operate by the timer from the accelerator off of Ta to the ignition stop of Tc of FIG. 9, and is set from the test result for each reference engine from the beginning, and the spark plug system controller of FIG. It is stored in LA 34. In step 5, ignition is continued. After that, the process proceeds to step 4 again. In step 6, ignition is stopped. In step 7, the engine rotation speed is measured. In step 8, it is determined whether the set engine rotation speed NE1 is less than or equal to the actually measured engine rotation speed NE. In the following cases, the process proceeds to step 9, and when it exceeds, the process proceeds to step 6 again. The engine speed NE1 that has been set is the same as the NE1 shown in FIG. 6, and is set from the test results for each reference engine from the beginning and stored in the spark plug system controller 34 shown in FIG. In step 9, ignition is restarted. In step 10, normal control is performed by step 1 and step 9. Finished in step 11.

FIG. 2 is a flow chart showing the fuel ignition control method (No. 2) of the engine of the present invention. This ignition control method (No. 2) is a flow chart in which the ignition command to the engine is output after the accelerator signal reaches zero and the rack position falls below a predetermined amount. It will be explained in order. In step 1, it is determined whether or not the engine rotation speed is higher than a predetermined amount.
When it is larger than the predetermined amount, the procedure proceeds to step 2, and when it is smaller, the procedure proceeds to step 10. The predetermined amount of engine rotation speed was set from the test results for each reference engine from the beginning, and
It is stored in the spark plug system controller 34. In step 2, it is judged whether or not the accelerator sensor output is zero. That is, it is determined whether or not the accelerator sensor output of FIG. 5 is zero when the accelerator of Ta shown in FIG. 6 is turned off to shift to deceleration. When the accelerator sensor output is zero, the process proceeds to step 3, and when the accelerator sensor output is not zero, the process returns to step 1. In step 3, it is determined whether or not the rack position is below a predetermined amount. When the amount is less than the predetermined amount, the process proceeds to step 4, and when it exceeds the amount, the process proceeds to step 10. The predetermined rack position amount is set at point C of time Tc in FIG. 7 from the test result for each reference engine from the beginning, and is stored in the spark plug system controller 34 in FIG. In step 4, the engine rotation speed is measured. In step 5, ignition is stopped. Go to step 4 again. In step 6, it is judged whether or not the rack is zero. This determination may be omitted if the time is short. When the rack is zero, go to step 7, and when it is over zero, step 4 again.
Return to. In step 7, the set engine speed NE is set.
It is determined whether or not 1 is less than or equal to the measured engine speed NE. In the following cases, the process proceeds to step 8, and when it exceeds, the process proceeds to step 4 again. Set engine speed N
E1 is the same as NE1 in FIG. 6, and is set from the test results for each reference engine from the beginning and stored in the spark plug system controller 34 in FIG. In step 8, ignition is restarted. Step 9 is step 8 and step 1
Normally controlled by. In step 10, ignition is continued.
Go to step 3 again. Finished in step 11. As a result, compared with the conventional case, the control of ignition stop and ignition restart to the engine is optimally performed in the non-injection region, and the discharge of unburned fuel is eliminated.

[0014]

As described above, according to the present invention,
When the fuel is an engine that uses alcohol, when the vehicle decelerates, that is, when the engine speed changes from high speed to low speed,
When the accelerator signal falls below a predetermined amount, the ignition signal to the engine is stopped in the non-injection region of the fuel injection amount, and at the same time the engine speed is reduced to the predetermined amount and the ignition command is output again in the non-injection region of the fuel injection amount. To do. In this way, the fuel ignition control method is optimized, the unburned fuel is not discharged, and as a result, the functional deterioration and stoppage of the catalytic converter are improved, and the life of the spark plug can be improved. Can be expected.

[Brief description of drawings]

FIG. 1 is a flowchart showing an engine fuel ignition control method (No. 1) according to the present invention.

FIG. 2 is a flow chart showing a fuel ignition control method (No. 2) for an engine of the present invention.

FIG. 3 shows an overall system diagram of a fuel ignition control device and a fuel injection device.

FIG. 4 is an explanatory diagram showing the relationship between the fuel injection amount (rack position) and the fuel ignition when the engine speed changes from high speed to low speed.

FIG. 5 is a diagram illustrating a time series change of an accelerator sensor output.

FIG. 6 is a diagram illustrating a time series change in rotation speed.

FIG. 7 is a diagram illustrating a time series change of a rack position.

FIG. 8 is a diagram illustrating a time series change of an injection amount.

FIG. 9 is a diagram illustrating a time series change of ignition.

[Explanation of symbols]

 10 Fuel Tank 11 Feed Pump 12 Fuel Filter 13 Fuel Injection Pump 13A Rack 13B Pump Body 13C Governor 14 Injection Nozzle 20 Battery 21 Ignition Coil 22 Spark Plug 30 Accelerator 31 Accelerator Sensor 32 Cylinder Discrimination Sensor 33 Crankshaft Rotation Angle, Rotation Speed Sensor 34 Ignition system controller 35 Rack sensor

Claims (4)

[Claims] 1. In an engine fuel ignition control method in which fuel is supplied by an accelerator operation and an ignition command is variably output to change a rotation speed, an output, and a torque, an accelerator signal is a predetermined amount or less. When
A method for controlling fuel ignition of an engine, comprising: stopping an ignition signal to the engine and outputting an ignition command again when the engine speed drops to a predetermined amount. 2. An ignition stop command to the engine is output after a predetermined time has elapsed from when the accelerator signal became less than a predetermined amount or after the rack position of the fuel supply device became less than a predetermined amount. A fuel ignition control method for an engine according to claim 1. 3. The fuel ignition control method for an engine according to claim 1, wherein the fuel is an alcohol. 4. A fuel ignition control method for an engine according to claim 1, wherein an accelerator signal equal to or less than a predetermined amount is zero.