JPH0828322A - Fuel supply control device for engine - Google Patents

Abstract

PURPOSE:To effectively suppress reciprocating oscillations generated on a vehicle when a fuel supply stopping condition is shifted to a fuel supply condition. CONSTITUTION:When it is judged that a fuel injection stopping condition is shifted to a fuel injection condition based on signals from sensor groups by a CPU 13, specified values of a fuel injection restarting delay time and fuel injection starting pattern are read out from a ROM 14. The specified values are stored in a RAM 15. Fuel injection into sequential cylinders are restarted by specified times according to the fuel injection starting pattern housed in the RAM 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine fuel supply for controlling the presence / absence of fuel supply for each cylinder of an engine at the time of transition from a fuel supply stop state to a fuel supply state in order to suppress longitudinal vibration generated in a vehicle. The present invention relates to a control device.

[0002]

2. Description of the Related Art While the vehicle is traveling, if the engine speed is higher than a predetermined value, mainly when the driver is not stepping on the accelerator, in order to prevent wasteful fuel consumption and to make a great effect of engine braking. The fuel supply to the engine is stopped. However, if the driver depresses the accelerator after the fuel supply to the engine is stopped or the engine speed becomes lower than a predetermined value, the output torque of the engine is reduced because the fuel supply to the engine is restarted. It grows in steps. In a vehicle with a manual transmission, a vehicle with an automatic transmission that directly connects the lock-up clutch during deceleration, etc., in such a state, torsional vibration occurs in the drive system and the vehicle vibrates back and forth. It causes discomfort.

In order to prevent such inconvenience
In the 60-81446 publication, when switching from the fuel supply stopped state to the fuel supply state, delaying the resumption of fuel supply to some cylinders smoothes the output torque of the engine that changes stepwise and is generated in the drive system. It has been proposed to reduce the torsional vibrations that occur.

[0004]

Generally, when the fuel supply is switched from the fuel supply stop state to the fuel supply state, the longitudinal vibration generated in the vehicle reaches its maximum amplitude about 150 msec after the switching is detected. In this case, about 100 ms from the time of switching detection
It is effective to control the fuel injection between ec, but for example, when the engine speed is around 1200 rpm in a 6-cylinder engine, the number of injection cylinders effective for control is only 5 to 6. FIG. 7A is an example of a fuel injection pattern to a cylinder by conventional control, B is another example of a fuel injection pattern to a cylinder by conventional control, and C is a case where these controls are performed and a case where no such control is performed. It is a time change of the drive shaft torque in the case. In this conventional example, fuel injection into cylinder numbers 1, 3 and 5 is delayed by a predetermined injection delay restart time.
When the cylinder that delays the restart of fuel injection is set in advance as in the conventional case, the cylinder that injects immediately after the switching is detected is the cylinder that delays the restart of fuel injection (FIG. 7B) and the cylinder that does not delay it (FIG. 7B). 7A), the number of times of actually stopping fuel injection is 2 to 3 out of the number of injection cylinders of 5 to 6 times.
It fluctuates with times. Therefore, the timing of changing the output torque of the engine is different, and there is a large variation in the vehicle vibration reduction effect between the drive shaft torque d by the control of the fuel injection pattern of FIG. 7A and the drive shaft torque e by the control of the fuel injection pattern of FIG. 7B. The drive shaft torque c cannot be effectively reduced when it is generated and is not controlled.

When the engine torque is changed smoothly after the accelerator is depressed to restart the fuel injection, the driver often feels insufficient acceleration. In order to prevent such hesitation from occurring, the engine torque should not be smoothed at the same time as switching from the fuel injection stopped state to the fuel injection state, but the engine torque should be temporarily reduced to prevent undesired vibration. Is preferably erased effectively. For this purpose, it may be necessary to stop the fuel injection again for the cylinder that once restarted the fuel injection. However, with the conventional control as described above, it is difficult to stop the cylinder once restarted within the control period even if the restart of fuel injection can be delayed.

An object of the present invention is to provide a fuel supply control device for an engine, which effectively suppresses longitudinal vibration generated in a vehicle when a fuel supply stop state is changed to a fuel supply state.

[0007]

A fuel supply control device for an engine according to the present invention comprises a fuel supply means for supplying fuel to successive cylinders of the engine according to an operating state, and the fuel supply according to the load of the engine. A fuel supply control device including a fuel supply stop means for stopping the fuel supply by the means, and a fuel supply restart for detecting that the fuel supply is restarted by switching the operation of the fuel supply stop means to the non-operation. When the fuel supply is restarted in response to the signal from the detection means and the fuel supply resumption detection means, the fuel is supplied to the sequential cylinders according to a predetermined cylinder selection pattern starting with the cylinder to which the fuel is supplied immediately after the restart. And a fuel supply resuming control means for resuming the operation for a predetermined number of times.

[0008]

In the engine fuel supply control device of the present invention, as shown in the conceptual diagram of FIG. 1, the fuel supply is resumed by switching the fuel supply stopping means from operating to non-operating. Is detected by the fuel supply resumption detecting means, when the fuel supply is resumed in response to the signal from the fuel supply resumption detecting means, a predetermined cylinder selection pattern starting with the cylinder to which the fuel is supplied immediately after the restart is followed. The fuel supply is restarted a predetermined number of times by the fuel supply restart control means.

In this way, when the fuel supply is restarted from the fuel supply stopped state, the fuel supply is restarted a predetermined number of times in a sequential cylinder according to a predetermined cylinder selection pattern starting with the cylinder to which the fuel is supplied immediately after the restart. Therefore, regardless of which cylinder is the fuel supply cylinder immediately after the fuel supply stop means is switched from the operating state to the non-operating state, the end time of the fuel supply control for reducing the vibration, the number of cylinders to stop the fuel supply, etc. It is possible to reproduce the same pattern as above, and therefore it is possible to effectively reduce the longitudinal vibration of the vehicle at the time of switching from the operation of the fuel supply stopping means to the non-operation.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an engine fuel supply control apparatus of the present invention will be described in detail with reference to the drawings. FIG. 2 is a schematic configuration diagram of the engine fuel supply control device of the present invention. This fuel supply control device includes a sensor group 1 having various sensors,
The microcomputer 2 includes a microcomputer 2 that receives signals from the sensor group 1 and performs various calculations, and an ignition device 3 and an injector group 4 to which output signals from the microcomputer 2 are supplied.

The sensor group 1 includes a gear position sensor 5 for detecting a gear position G of the transmission, a vehicle speed sensor 6 for detecting a vehicle speed V, and an engine water temperature sensor 7 for measuring an engine water temperature C.
An angle sensor 8 that outputs an angle signal θ for each predetermined angle of the crank angle and controls the timing, an engine speed sensor 9 that detects an engine speed Ne, and whether or not the throttle valve is at the idle opening TH. A throttle switch 10 for detecting whether or not, and an air flow meter 1 for detecting an intake air amount Q for detecting a load state of the engine.
1 and.

The microcomputer 2 receives the signal from the sensor group 1 and supplies an output signal to the ignition device 3 and the injector group 4, and an CP.
U13, the fuel injection start counter corresponding to the signal from the sensor group 1, and the initial predetermined value TI of the fuel injection start pattern
ROM 14 in which MPSR and RCVPTN are preset
And the initial predetermined value TIMPS read from the ROM 14.
It has a RAM 15 for storing R and RCVPTN to exchange information with the CPU 13, and a clock oscillator 16 for outputting a clock pulse which is the basis of calculation.

The ignition device 3 includes a transistor 17 that opens and closes in response to an ignition signal, an ignition coil 18 that ignites when a high voltage is generated when the transistor 17 is turned off by an ignition signal, and a distributor 19. , A spark plug 20 provided for each of the square cylinders.

The operation of this example will be described. FIG. 3 is a flowchart for determining the transition from the fuel injection stopped state to the fuel injection state. This routine determines the transition from the fuel injection stopped state to the fuel injection state based on the ON / OFF of the idle switch, and is executed, for example, every 10 msec.

First, at step 21, it is judged whether or not the idle switch is ON based on a signal from the throttle switch 10 (FIG. 2). Idle switch is ON
If so, other jobs are executed in step 22, and this control routine is ended.

If it is determined in step 21 that the idle switch is not ON, it is determined in step 23 whether the fuel injection is stopped or not.
The determination is made based on the intake air amount Q detected from (FIG. 2). If the fuel injection is not stopped, another job is executed in step 22 and this control routine is ended.

When it is determined in step 23 that the fuel injection is stopped, the fuel injection start flag is set to 1 and the fuel injection start counter for measuring the elapsed time after the start of the fuel injection control and the fuel to the successive cylinders injection,
Initial predetermined value TIM for the fuel injection start pattern for non-injection
The PSR and RCVPTN are stored respectively. These initial predetermined values TIMPSR and RCVPTN are stored in the ROM 14
It is read from (FIG. 2) to the CPU 13 (FIG. 2) and stored in the working RAM 15 (FIG. 2). Then step 2
In step 2, other jobs are executed, and this control routine ends.

FIG. 4 shows a predetermined cylinder selection pattern in which the cylinder to which the fuel is injected immediately after the fuel injection is restarted is selected.
It is a flow chart which directly performs fuel injection and non-injection to a sequential cylinder. This routine is executed based on the information from the control routine of FIG.

First, at step 26, it is judged whether the fuel injection stop state is changed to the fuel injection state, that is, whether the value of the fuel injection start flag is 1. When the value of the fuel injection start flag is not 1, the fuel injection is stopped in step 27, and then the fuel injection start flag and the fuel injection start counter are all cleared to 0 in step 28, and this control routine is ended.

When it is determined in step 26 that the value of the fuel injection start flag is 1, it is determined in step 29 whether the fuel injection control has been performed for a predetermined time, that is, whether the value of the fuel injection start counter is 0. To judge. 0
If so, perform fuel injection in step 30,
After that, in step 28, the fuel injection start flag and the fuel injection start counter are all cleared to 0, and this control routine ends.

If it is determined in step 29 that the value of the fuel injection start counter is not 0, the fuel injection start counter is decremented in step 31. Next, at step 32, an initial predetermined value RC of the fuel injection start pattern
Based on the VPTN, the flag (C) stores information as to whether or not the current control target cylinder performs fuel injection. In this case, for example, 1 is stored when fuel is injected into the control target cylinder, and 0 is stored when fuel injection is stopped.

In step 33 after step 32,
It is determined whether fuel is injected into the control target cylinder this time, that is, whether the value of the flag (C) is 1. When the value of the flag (C) is 1, fuel is injected into the cylinder to be controlled this time in step 34, and this control routine ends. If the value of the flag (C) is not 1, step 35
At this time, the fuel injection to the cylinder to be controlled this time is stopped, and this control routine is ended.

FIG. 5 shows a predetermined cylinder selection pattern in which the cylinder to which fuel is injected immediately after the fuel injection is restarted is selected.
6 is a flowchart for setting fuel injection and non-injection in a sequential cylinder. This routine is also executed based on the information from the control routine of FIG. In this example, it is determined at any time whether the next control target cylinder is fuel injection or non-injection, and control data for another control routine for actually executing fuel injection or non-injection is created. . Step 36
At the initial predetermined value RCVP of the fuel injection disclosure pattern
Based on TN, the flag (C ′) stores information as to whether or not the next control target cylinder will perform fuel injection. In this case, for example, 1 is stored when the fuel is injected into the next control target cylinder, and 0 is stored when the fuel injection is stopped. When the flag (C) is determined to be 1 in step 37, the next cylinder is stored in the RAM 15 (FIG. 2) as a fuel injection cylinder in step 38. When it is determined that the value is not 1, step 39
RAM15 as the next cylinder in which fuel injection is stopped
(FIG. 2). Then, based on the data stored in the RAM 15, actual fuel injection and non-injection are executed in another control routine. Other operations are the same as the control routine of the flowchart of FIG.

FIG. 6A is an example of a fuel injection pattern for a cylinder under the control of the present invention, B is another example of a fuel injection pattern for a cylinder under the control of the present invention, and C is a case where these controls are performed. And the change over time of the drive shaft torque when control is not performed. In the control according to the present invention, as shown in FIGS. 6A and 6B, regardless of the number of the fuel injection cylinder immediately after the transition from the fuel injection stopped state to the fuel injection state, the predetermined value of the fuel injection counter is determined according to the predetermined value RCVPTN of the fuel injection pattern. The fuel injection can be executed during the value TIMPSR, and the drive shaft torque a when the control is not performed can be controlled like the drive shaft torque b according to the control of the present invention.

As described above, in this embodiment, the fuel supply is stopped for the end time of the fuel injection control for reducing the vibration regardless of which cylinder is the fuel supply cylinder immediately after the transition from the fuel injection stop state to the fuel injection state. It is possible to reproduce the number of cylinders and the like that are operated in the same pattern on the time axis, and therefore it is possible to effectively reduce the longitudinal vibration of the vehicle immediately after the transition from the fuel injection stopped state to the fuel injection state.

The present invention is not limited to the above-described embodiment, but various modifications and changes can be made. For example,
The transition from the fuel injection stopped state to the fuel injection state is judged based on the on / off state of the idle switch or the magnitude of the engine speed, but the shift based on the gear position G of the transmission detected by the gear position sensor 5 (FIG. 2). The gear ratio of the machine,
The magnitude of the vehicle speed V detected by the vehicle speed sensor 6 (FIG. 2), the magnitude of the engine water temperature C measured by the engine water temperature sensor 7 (FIG. 2), the engine speed detected by the engine speed sensor 9 (FIG. 2) Ne size, throttle switch 1
0 (FIG. 2), the accelerator pedal depression amount based on the idle opening TH, the accelerator pedal depression speed read out via the input / output circuit 12 (FIG. 2) and processed by the CPU 13 (FIG. 2). The judgment can be made based on the size.

[0027]

As described above, according to the fuel supply control device for an engine of the present invention, when the fuel supply is restarted from the fuel supply stop state as described above, a predetermined cylinder headed with the cylinder to which the fuel is supplied immediately after the restart is provided. Since the fuel supply is restarted a predetermined number of times according to the cylinder selection pattern of No. 3, in order to reduce the vibration regardless of which cylinder is the fuel supply cylinder immediately after the operation of the fuel supply stopping means is switched to the non-operation. It is possible to reproduce the end time of the fuel supply control, the number of cylinders to stop the fuel supply, etc. in the same pattern on the time axis, and therefore the longitudinal vibration of the vehicle at the time of switching the operation of the fuel supply stop means to the non-operation is effective. Can be reduced to

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a fuel supply control device for an engine of the present invention.

FIG. 2 is a schematic configuration diagram of a fuel supply control device for an engine of the present invention.

FIG. 3 is a flowchart for determining a transition from a fuel injection stopped state to a fuel injection state.

FIG. 4 is a flowchart for performing fuel injection and non-injection on successive cylinders in accordance with a predetermined cylinder selection pattern in which a cylinder to which fuel is to be injected is headed immediately after restarting fuel injection.

FIG. 5 is another flowchart in which fuel injection and non-injection are sequentially performed to the cylinders according to a predetermined cylinder selection pattern in which the cylinder to which the fuel is injected immediately after the fuel injection is restarted is selected.

FIG. 6A is an example of a fuel injection pattern into a cylinder under the control of the present invention, B is another example of a fuel injection pattern into a cylinder under the control of the present invention, and C is a change over time of the drive shaft torque. Is.

FIG. 7A is an example of a fuel injection pattern to a cylinder by conventional control, B is another example of a fuel injection pattern to a cylinder by conventional control, and C is a time change of drive shaft torque. .

[Explanation of symbols]

1 Sensor Group 2 Microcomputer 3 Ignition Device 4 Injector Group 5 Gear Position Sensor 6 Vehicle Speed Sensor 7 Engine Water Temperature Sensor 8 Angle Sensor 9 Engine Rotation Sensor 10 Throttle Switch 11 Airflow Meter 12 Input / Output Circuit 13 CPU 14 ROM 15 RAM 16 Clock Oscillator 17 Transistor 18 Ignition coil 19 Distributor 20 Spark plug G Gear position V Vehicle speed C Engine water temperature θ Angle signal Ne Engine speed TH Idle opening Q Intake air amount a, c Drive shaft torque b when control is not performed Control of the present invention 6 d Drive shaft torque d by controlling the fuel injection pattern of FIG. 6A e Drive shaft torque by controlling the fuel injection pattern of FIG. 6B

Claims (1)

[Claims] 1. A fuel supply means for supplying fuel to successive cylinders of an engine according to an operating state, and a fuel supply stopping means for stopping fuel supply by the fuel supply means according to the load of the engine. In the fuel supply control device, a fuel supply resumption detecting means for detecting that the fuel supply is restarted by switching from the operation of the fuel supply stopping means to the non-operation, and responding to a signal from the fuel supply resumption detecting means. When restarting the fuel supply, the fuel supply restart control means is configured to restart the fuel supply to the sequential cylinders according to the predetermined cylinder selection pattern starting with the cylinder to which the fuel is to be supplied immediately after the restart for a predetermined number of times. A fuel supply control device for an engine, wherein: