JPS63179149A - Fuel control device for engine - Google Patents

Abstract

PURPOSE:To prevent the occurrence of torque shock during slow acceleration, by a method wherein when fuel feed is restored from a deceleration running state in which the feed of fuel is stopped, a current amount of a change in a throttle opening is detected, and fuel feed is restored at a rate of change in an increase amount which is increased as an amount of a change is increased. CONSTITUTION:When the deceleration state of an engine is detected by a deceleration detecting means 4, a fuel feed stop means 5, stopping the feed of fuel from a fuel feed means 3, is provided. A fuel feed restoring means 7 is provided for releasing a stop of fuel feed, effected by a fuel feed stop means 5, when a deceleration release detecting means 6 detects that an engine is released from a deceleration state. The fuel feed restoring means 7 is also adapted to output a signal to a fuel feed means 3 so that fuel is fed in a given rate of change so as to satisfy demand fuel. The rate of change is corrected by a rate of change correcting means 9 so that the more an amount of a change in a throttle opening detected by a throttle opening change amount detecting means 8 is increased, the more the rate of the change is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a fuel control 2+1 device for an engine that stops the supply of fuel during deceleration operating conditions.

(Prior Art) Conventionally, an engine fuel control device has stopped the supply of fuel during deceleration operation, and when restoring the fuel supply from the fuel supply stop state, it has gradually stopped the fuel supply in order to reduce the shock. A technique for increasing and returning to normal is known, for example, as seen in Japanese Patent Publication No. 56-38781.

(Problem to be Solved by the Invention) However, in the device that stops fuel supply during deceleration operation as described above, when transitioning from deceleration operation state to acceleration operation state, fuel is gradually supplied at a constant increase rate. If you perform a return, torque shock may occur during slow acceleration,
There is a possibility that the acceleration performance during sudden acceleration may be insufficient.

In other words, for example, if the degree of increase in m at the time of return is set in accordance with a sudden acceleration state, the fuel supply amount will suddenly increase during slow acceleration, and in addition to the torque shock caused by just starting fuel supply, a large torque will be generated. A shock occurs. On the other hand, if the degree of retraction at the time of return is set in accordance with the slow acceleration state, the increase in fuel value relative to the required fuel amount will be delayed during sudden acceleration, resulting in a decrease in acceleration response.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a fuel control device for an engine that achieves both prevention of torque shock and acceleration responsiveness when fuel supply is restored from a state where fuel supply is stopped during deceleration operation. That is.

(Means for Solving the Problems) The fuel control device of the present invention includes fuel supply means that receives the output of an operating state detection means for detecting the operating state of the engine and supplies fuel to the engine according to the operating state. and a fuel supply stop means for receiving the output of the deceleration detecting means for detecting the deceleration state of the engine, and stopping the supply of fuel by the fuel supply means after the deceleration state is detected, further comprising: a fuel supply return means that receives an output from a deceleration release detection means that detects that the deceleration has been released, and supplies fuel at a predetermined rate of change so that the required fuel corresponds to the operating state when the deceleration state is released; and a rate of change correction means that receives the output of a throttle opening change amount detection means that detects a change amount of the throttle opening degree, and corrects the rate of change so that the larger the change amount of the throttle opening degree is, the larger the change rate is. It is characterized by:

FIG. 1 is a block diagram for clearly showing the configuration of the present invention.

The engine 1 is provided with a fuel supply means 3 that receives an output from an operating state detection means 2 that detects the operating state of the engine and supplies fuel according to the operating state.

Further, the deceleration state of the engine 1 is detected by the deceleration detection means 4, and the fuel supply stop means 5 receives the output of the deceleration detection means 4, and when the deceleration state is detected, the fuel supply means 3
Stopping the fuel supply.

Further, when the deceleration release detection means 6 detects that the deceleration state of the engine 1 is released, the fuel supply return means 7
As a result, the stoppage of fuel supply by the fuel supply stop means 5 is canceled, and a signal is output to the fuel supply means 3 to supply fuel at a predetermined rate of change so as to obtain the required fuel according to the operating state. It is something.

Further, a throttle opening change amount detecting means 8 is provided for detecting the amount of change in the throttle opening degree, and the output of this throttle opening degree change old detecting means 8 is outputted to a change rate correcting means 9.

The rate of change correction means 9 corrects the rate of change by the fuel supply return means 7 to increase as the amount of change in the throttle opening degree increases, that is, the degree of acceleration increases.

(Function) In the above-described fuel control device, when the engine enters a deceleration operation state, the fuel supply stop means stops the fuel supply, and when the deceleration state is released, the amount of change in the throttle opening at that time is The larger the change ω, the greater the rate of change in the fuel supply is restored, and by supplying fuel corresponding to the acceleration state, torque shock during slow acceleration can be eliminated and good acceleration performance can be obtained.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 2 is an overall configuration diagram of a specific example.

An air cleaner 12, an air flow meter 13, and a throttle valve 14 are installed in the intake passage 11 that supplies intake air to the engine 1 from the upstream side, and an air-fuel ratio sensor 16, A catalytic converter 17 is interposed in each case.

Further, a fuel injection valve 18 for injecting and supplying fuel is disposed at the downstream end portion of the intake passage 11, and this fuel injection valve 18
, fuel is supplied from the fuel tank 19 through a fuel supply passage 23 that includes a low-pressure side filter 20 , a fuel pump 21 , and a high-pressure side filter 22 , and excess fuel is passed through a fuel pressure regulator 24 and returned to the fuel tank 19 through a return passage 25 . be returned.

The fuel supply from the fuel injection valve 18 is controlled by a control signal (fuel injection pulse) from a control unit 26 to the fuel injection valve 18. The control unit 26 includes the throttle valve 1
In addition to the throttle opening signal from the throttle sensor 27 that detects the opening of the engine 4 and the engine rotation signal from the rotation sensor 28 that detects the engine rotation speed, detection signals from the air flow meter 13, the air-fuel ratio sensor 16, etc. Each is input.

The control unit 26 basically calculates the fuel injection amount corresponding to the operating state according to the intake air m and the engine speed, and outputs a corresponding fuel injection pulse to the fuel injection valve 18 to achieve a predetermined value. The system injects and supplies fuel. In addition, the deceleration state is detected from the throttle opening degree and engine speed, and when deceleration occurs, fuel supply is stopped, while when the deceleration state is canceled and the transition is made to an acceleration state, etc., the deceleration state is detected according to the operating state after cancellation. When the requested fuel is started to be injected and supplied, the fuel supply is restored at a predetermined rate of change, and this rate of change is corrected according to the degree of acceleration. The degree of acceleration is detected from the amount of change in the throttle opening, and the rate of change in fuel increase m is corrected in accordance with the amount of change in the throttle opening, so that the larger the amount of throttle change, the greater the rate of change in fuel increase m. This is to control the return.

Next, the operation of the control unit 26 will be explained based on the flowchart shown in FIG. This flowchart only shows a fuel control routine for returning fuel from a fuel supply stop state during deceleration. After the start, various signals such as throttle opening TV and engine rotation speed N are read in step S1, and based on these signals, it is determined in step S2 whether or not the fuel cut zone is reached. This fuel cut zone is a region where the throttle opening degree TV is fully open and the engine speed N is a predetermined value (for example, 2000 rpm or more).

Then, when the operating state is in the fuel cut zone and the determination in step S2 is YES, it is determined in step S3 whether or not the state has transitioned to an acceleration state. This determination is made based on whether the current throttle opening degree TV is larger than the previous throttle opening degree Tvo, and the determination in step S3 is made when the throttle opening degree TV shifts to an acceleration state in which it is operated in an increasing direction. When becomes YES, the timer value CE is counted in step S4. This counting of the timer value CE continues N times until the determination in step S2 or step S3 becomes No and the timer ffl CE is reset in step S5.

Step S6 is to determine whether or not the throttle opening degree TV has reached a predetermined opening degree TV1 or more, and this predetermined opening degree TVs is set, for example, to the timing when an idle switch that closes when the throttle is fully opened opens. , the determination is made in response to whether the idle switch is on or off. Then, the idle switch is turned off when the throttle opening TV reaches the predetermined opening TVr), and the determination in step S6 is YES.
When S is reached, the timer value GE counted in step S4 is read in step S7, and this timer value GE is
Fuel return gradient C according to (111th increase maximum fuel pulse width)
is obtained from the table (S8).

The timer value CE corresponds to the time required for the throttle opening TV to be opened to a predetermined opening TV t, and the smaller the value, the more rapid acceleration is required;
Correspondingly, the fuel return gradient C is set to a large value when the timer value CE is short, and the rate of increase in the pulse width becomes large.

After calculating the gradient C at the time of return as described above, if it is determined in step S9 that the operating state has moved outside the fuel cut zone, fuel supply recovery is executed based on the gradient C in step S10. be.

As shown in FIG. 4, the execution of the above-mentioned fuel supply restoration starts with determining the minimum amount of fuel m T s that can be ignited at 8 points at the start of supply.
is supplied, and then, based on the gradient C, a required injection pulse T2. corresponding to the operating state is supplied. Until the value corresponding to T3 is reached, the amount of fuel is increased at a large rate of change as shown by the broken line A during rapid acceleration, and at a small rate of change as shown by the solid line B during slow acceleration. Thereby, the fuel can be increased ω in accordance with the acceleration state corresponding to the amount of change in the throttle opening, and fuel control can be executed in accordance with the required output characteristics. Incidentally, the fuel amount may be increased gradually based on the gradient C from the beginning when the fuel supply is restored.

(Effects of the Invention) According to the present invention as described above, when the fuel supply is restored from a deceleration operation state where the fuel supply is stopped, the amount of change in the throttle opening at that time is detected and the change is detected. By making the fuel supply return at a higher rate of increase as the amount increases, the fuel supply corresponds to the acceleration state, eliminating torque shock during slow acceleration, and providing good performance during sudden acceleration. It is possible to obtain acceleration performance.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an engine fuel control device to clearly demonstrate the configuration of the present invention, Fig. 2 is an overall configuration diagram of a specific example engine, and Fig. 3 is a flowchart diagram to explain the operation of the control unit. , FIG. 4 is a characteristic diagram showing the fuel supply characteristics at the time of return. 1...Engine 2...Operating state detection means 3...Fuel supply means 4...Deceleration detection means 5...Fuel supply stop means 6...Deceleration release detection means 7...Fuel supply return means 8...Throttle opening change amount detection means 9...
... Rate of change correction means 14 ... Throttle valve 18 ... Fuel injection valve 26 ... Control unit 27 ...
・Throttle sensor 28...Rotation sensor

Claims (1)

[Claims] (1) Operating state detection means for detecting the operating state of the engine; fuel supply means that receives the output of the operating state detection means and supplies the engine with fuel according to the operating state; and detects the deceleration state of the engine. A fuel control device for an engine, comprising: a deceleration detecting means; and a fuel supply stop means that receives an output of the deceleration detecting means and stops supplying fuel by the fuel supply means when a deceleration state is detected. a deceleration release detection means for detecting that the deceleration state has been released; and a predetermined change in response to the output of the deceleration release detection means so that when the deceleration state is released, the required fuel is in accordance with the operating state. a fuel supply return means for returning fuel supply at a certain rate; a throttle opening change detection means for detecting a change in throttle opening; and a throttle opening change detection means for detecting an output from the throttle opening change detection means; 2. A fuel control device for an engine, comprising: a rate of change correction means for correcting the rate of change of the fuel supply return means to increase as the value increases.