JP3322003B2 - Engine fuel supply control device - Google Patents

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 or absence of fuel supply for each cylinder of an engine when shifting 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 During driving of a vehicle, if the driver is not stepping on the accelerator and the engine speed is higher than a predetermined value, it is necessary to prevent wasteful fuel consumption or to make the engine brake effective. The fuel supply to the engine is stopped. However, if the driver steps on the accelerator after the fuel supply to the engine is stopped, or if the engine speed becomes lower than a predetermined value, the fuel output to the engine is resumed and the output torque of the engine is reduced. It grows like a step. In a vehicle with a manual transmission, a vehicle with an automatic transmission in which a lock-up clutch is directly engaged at the time of deceleration, etc., in such a state, a torsional vibration occurs in the drive system, and the vehicle vibrates back and forth, so that the driver is instructed. Gives discomfort.

In order to prevent such inconvenience, Japanese Patent Application Laid-Open
According to Japanese Patent Publication No. 60-81446, when switching from a fuel supply stop state to a fuel supply state, the restart of fuel supply to some cylinders is delayed to smooth the output torque of the engine that changes in a step-like manner, and is generated in the drive train. It has been proposed to reduce torsional vibrations.

[0004]

Generally, when switching from the fuel supply stopped state to the fuel supply state, the longitudinal vibration generated in the vehicle has a maximum amplitude about 150 msec after the switch is detected. In this case, about 100 ms from the detection of switching
It is effective to control the inter-ec fuel injection. However, for example, in the case of a six-cylinder engine and the engine speed is around 1200 rpm, there are only five to six injection cylinders effective for control. 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 no control is performed. Of the drive shaft torque over time. In this conventional example, the fuel injection into the cylinder numbers 1, 3, and 5 is delayed by a predetermined injection delay restart time.
If a cylinder that delays the restart of fuel injection is set in advance as in the related art, the cylinder that injects immediately after the switching is detected is a cylinder that delays the restart of fuel injection (FIG. 7B) and a cylinder that does not delay the restart (FIG. 7B). 7A), the number of times that fuel injection is actually stopped out of the number of injection cylinders of 5 to 6 times is 2 to 3
Times and vary. Therefore, the timing at which the output torque of the engine is changed is different, and the drive shaft torque d by the control of the fuel injection pattern in FIG. 7A and the drive shaft torque e by the control of the fuel injection pattern in FIG. As a result, the drive shaft torque c when control is not performed cannot be effectively reduced.

When the engine torque is smoothly changed after the fuel injection is restarted by depressing the accelerator, the driver often feels that the acceleration is insufficient. In order to prevent such hesitation from occurring, instead of smoothing the engine torque at the same time as switching from the fuel injection stop state to the fuel injection state, the engine torque is temporarily reduced to reduce only undesired vibrations. Is preferably erased effectively. For this purpose, it is necessary to stop the fuel injection again for the cylinder that has once restarted the fuel injection. However, in the conventional control as described above, even if the restart of fuel injection can be delayed, it is difficult to stop the cylinder once restarted again within the control period.

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

[0007]

According to the present invention, there is provided a fuel supply control device for an engine, comprising: a fuel supply means for supplying fuel to each cylinder in accordance with an operating state of the engine; A fuel supply control device for an engine, the fuel supply control device comprising: a fuel supply stopping means for stopping the fuel supply by the means; and detecting that the fuel supply has been restarted by switching the fuel supply stopping means from operation to non-operation. Supply restart detection means, and when fuel supply is restarted in response to a signal from the fuel supply restart detection means, fuel is sequentially supplied to the cylinders according to a predetermined cylinder selection pattern starting with the cylinder at the fuel supply timing. Immediately after the supply is continuously performed for two or more cylinders, fuel supply restart control means is provided for stopping the fuel supply for one cylinder.

[0008]

According to the fuel supply control device for an engine of the present invention, as shown in the conceptual diagram of FIG. 1, the fuel supply is resumed by switching the operation of the fuel supply stop means from the operation to the non-operation. When detected by the detecting means, when the fuel supply is restarted in response to the signal from the fuel supply restart detecting means, the cylinders are sequentially switched to cylinders according to a predetermined cylinder selection pattern starting with the cylinder at the fuel supply timing. Immediately after the fuel supply is continuously performed for two or more cylinders, the fuel supply to the cylinders in accordance with a predetermined cylinder selection pattern starting with the cylinder at the fuel supply timing at which the fuel supply is stopped for one cylinder is performed. Immediately after the cylinders are continuously operated, fuel supply is stopped for one cylinder.

When the fuel supply is restarted in response to the signal from the fuel supply restart detecting means as described above, the fuel supply to the cylinders in order according to a predetermined cylinder selection pattern starting with the cylinder at the fuel supply timing. Immediately after the fuel supply restart control means performs two or more cylinders continuously, the fuel supply is stopped for 1
In order to perform the cylinder, even if the fuel supply cylinder is any cylinder immediately after the fuel supply stop means is switched from operation to non-operation,
The end time of fuel supply control for reducing vibration, the number of cylinders for stopping fuel supply, and the like can be reproduced in the same pattern on the time axis, and therefore, when the operation of the fuel supply stop means is switched from inactive to inactive The longitudinal vibration of the vehicle at the time of switching can be effectively reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fuel supply control device for an engine according to 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 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 crank angle and controls the timing, an engine speed sensor 9 that detects the engine speed Ne, and whether the throttle valve is at the idle opening TH. And an air flow meter 1 for detecting an intake air amount Q for detecting an engine load state.
With 1.

The microcomputer 2 has an input / output circuit 12 which receives a signal from the sensor group 1 and supplies an output signal to the igniter 3 and the injector group 4;
U13, a fuel injection start counter corresponding to a signal from the sensor group 1, and an initial predetermined value TI of a fuel injection start pattern.
ROM14 in which MPSR and RCVPTN are preset
And the initial predetermined value TIMPS read from the ROM 14
It includes a RAM 15 that stores R and RCVPTN to transfer information to and from the CPU 13, and a clock oscillator 16 that outputs a clock pulse that is a basis for calculation.

The igniter 3 includes a transistor 17 that opens and closes in response to an ignition signal, an ignition coil 18 that generates a high voltage when the transistor 17 is turned off by the ignition signal, and performs ignition. And a spark plug 20 installed for each cylinder.

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

First, at step 21, it is determined 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, another job is executed in step 22 and the control routine is terminated.

If it is determined in step 21 that the idle switch is not ON, it is determined in step 23 whether fuel injection has been stopped. If the fuel injection has not been stopped, another job is executed in step 22, and the control routine ends.

If it is determined in step 23 that the fuel injection has been 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 is sequentially stored in the cylinder. injection,
Initial predetermined value TIM for fuel injection start pattern for non-injection
PSR and RCVPTN are stored. These initial predetermined values TIMPSR and RCVPTN are stored in the ROM 14
The data is read from the CPU 13 (FIG. 2) from FIG. 2 and stored in the work RAM 15 (FIG. 2). Then step 2
In step 2, other jobs are executed, and the control routine ends.

FIG. 4 shows a predetermined cylinder selection pattern in which a cylinder to be injected with fuel immediately after resuming fuel injection is selected.
It is a flowchart which performs execution of fuel injection and non-injection to a cylinder sequentially. This routine is executed based on information from the control routine of FIG.

First, in step 26, it is determined whether or not the fuel injection has been shifted from the stopped state to the fuel injection state, that is, whether or not the value of the fuel injection start flag is 1. If the value of the fuel injection start flag is not 1, the fuel injection is stopped in step 27, and thereafter, in step 28, the fuel injection start flag and the fuel injection start counter are all cleared to 0, and this control routine is ended.

If it is determined in step 26 that the value of the fuel injection start flag is 1, in step 29, it is determined 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. Judge. 0
, Fuel injection is performed in step 30;
Thereafter, in step 28, the fuel injection start flag and the fuel injection start counter are all cleared to 0, and this control routine is terminated.

If it is determined in step 29 that the value of the fuel injection start counter is not 0, the flow proceeds to step 31 in which the fuel injection start counter is decremented. Next, at step 32, the initial predetermined value RC of the fuel injection start pattern
Based on the VPTN, the flag (C) stores information on 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 current control target cylinder, and 0 is stored when fuel injection is stopped.

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

FIG. 5 shows a predetermined cylinder selection pattern in which the cylinder to be injected with fuel immediately after the restart of fuel injection is selected.
It is a flowchart which performs setting of fuel injection and non-injection to a cylinder sequentially. This routine is also executed based on 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
, The initial predetermined value RCVP of the fuel injection start pattern
Based on the TN, the flag (C ′) stores information on whether or not the next control target cylinder performs fuel injection. In this case, for example, 1 is stored when fuel is injected into the next cylinder to be controlled, and 0 is stored when fuel injection is stopped. In step 37, the flag (C ')
Is determined to be 1 in step 38, the next cylinder is stored in the RAM 15 (FIG. 2) as a fuel injection cylinder. If it is not 1, then step 3
9, the next cylinder is set to the RAM1
5 (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 shows an example of a fuel injection pattern to the cylinder by the control of the present invention. FIG. 6B shows another example of a fuel injection pattern to the cylinder by the control of the present invention. And the time variation 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 stop 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. Fuel injection can be performed during the value TIMPSR, and the drive shaft torque a when control is not performed can be controlled like the drive shaft torque b by the control of the present invention.

As described above, in the present embodiment, the fuel injection control end time for reducing the vibration and the fuel supply are stopped immediately after the transition from the fuel injection stop state to the fuel injection state, regardless of the fuel supply cylinder. The number of cylinders to be performed can be reproduced in the same pattern on the time axis, so that the longitudinal vibration of the vehicle immediately after the transition from the fuel injection stop state to the fuel injection state can be effectively reduced.

The present invention is not limited to the above-described embodiment, and many modifications and changes are possible. For example,
The shift from the fuel injection stop state to the fuel injection state is determined based on the on / off state of the idle switch or the magnitude of the engine speed. However, 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 vehicle speed V detected by the vehicle speed sensor 6 (FIG. 2), 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
The accelerator depression amount based on the detected idle opening TH from 0 (FIG. 2) and the accelerator depression speed read out via the input / output circuit 12 (FIG. 2) and processed by the CPU 13 (FIG. 2). The determination can also be made based on the magnitude or the like.

As described above, according to the fuel supply control device for an engine of the present invention, when the fuel supply is restarted in response to the signal from the fuel supply restart detecting means, the cylinder at the fuel supply time is set to the first position. The fuel supply to the cylinders is sequentially performed according to the predetermined cylinder selection pattern described above, and immediately after two or more cylinders are continuously performed by the fuel supply restart control means, the fuel supply is stopped for one cylinder. Regardless of the fuel supply cylinder immediately after switching from operation to non-operation, the end time of fuel supply control to reduce vibration, the number of cylinders to stop fuel supply, etc. are reproduced in the same pattern on the time axis 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.

[Brief description of the drawings]

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

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

FIG. 3 is a flowchart for determining a shift from a fuel injection stop 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 beginning with a cylinder on which fuel is injected immediately after restarting fuel injection.

FIG. 5 is another flowchart in which fuel injection and non-injection are sequentially performed on cylinders in accordance with a predetermined cylinder selection pattern starting with a cylinder on which fuel is injected immediately after restarting fuel injection.

FIG. 6A is an example of a fuel injection pattern to a cylinder by the control of the present invention, B is another example of a fuel injection pattern to the cylinder by the control of the present invention, and C is a time change of the drive shaft torque. It 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]

DESCRIPTION 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 Air flow 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 coolant temperature θ Angle signal Ne Engine speed TH Idle opening Q Intake air amount a, c Drive shaft torque when no control is performed b Control of the present invention Drive shaft torque by controlling the fuel injection pattern of FIG. 7A e Drive shaft torque by controlling the fuel injection pattern of FIG. 7B

Claims (1)

(57) [Claims] 1. A fuel supply means for supplying fuel to each cylinder according to an operation state of an engine, and a fuel supply stop means for stopping fuel supply by the fuel supply means according to a predetermined engine load. In the fuel supply control device for an engine, fuel supply restart detection means for detecting that fuel supply has been restarted by switching from operation to non-operation of the fuel supply stop means, and a signal from the fuel supply restart detection means When the fuel supply is restarted in response to the fuel supply, immediately after two or more cylinders are continuously supplied with fuel in accordance with a predetermined cylinder selection pattern starting with the cylinder at the fuel supply timing, And a fuel supply resumption control means for stopping the fuel supply for one cylinder.