JPS60247022A - Fuel supply control device in engine - Google Patents

Abstract

PURPOSE:To prevent torque variations and power shortage, by carrying out the learning control of amount of recovery supply fuel upon release of fuel-cut. CONSTITUTION:A fuel-cut signal generating means (c) delivers a fuel-cut signal when an engine operates in a predetermined decelerating operation range. When the fuel-cut is released, a memory means (e) compensates the amount of supply fuel in accordance with the condition of engine combustion so that the amount of supply fuel has an optimum value corresponding to the operating condition of the engine, and the amount of supply fuel is learned when the amount of supply fuel is optimum. Further, this optimum amount of supply fuel is stored in the memory. With this arrangement, it is possible to prevent torque variations and power shortage.

Description

[Detailed description of the invention] (Technical field) The present invention relates to an engine fuel supply control device.

(Prior art) In general, in engines that perform fuel casing, it is necessary to supply an appropriate amount of fuel according to the operating condition when the fuel casing is released (hereinafter referred to as temporary recovery) so as not to impair drivability. be.

Conventional fuel supply control devices for this type of engine include:
For example, "Technical Manual ECC5L Series Engine" (Showa 5
There is something described in June 2010 (Published by Nissan Motor Co., Ltd.).

This device calculates a correction coefficient to correct the air-fuel ratio to the stoichiometric air-fuel ratio based on the output of an oxygen sensor installed in the exhaust passage, and also corrects the fuel supply amount using this correction coefficient to bring the air-fuel ratio to the stoichiometric air-fuel ratio. Feedbank control. In general, the oxygen sensor described above is capable of detecting other than the stoichiometric air-fuel ratio. Furthermore, when decelerating from high rotation, the fuel supply is stopped (a fuel cut is performed) to prevent the generation of unburned gas and save fuel. In this case, the fuel cut area varies depending on, for example, the cooling water temperature, and is referred to as the fuel supply amount at the time of recovery (hereinafter referred to as recovery supply amount Tr).
is set to a certain amount in advance.

On the other hand, in recent years, from the perspective of energy saving, lean air-fuel ratio (air-fuel ratio that is leaner than the stoichiometric air-fuel ratio; the same applies hereinafter)
Attempts have been made to provide feedback control to this, and one example of this type of control is described in Japanese Patent Application Laid-Open No. 56-89051. The oxygen sensor used in this device has a characteristic that its output voltage varies depending on the air-fuel ratio depending on the value of the injected current, and this characteristic is utilized to accurately feedback control the lean air-fuel ratio.

However, such conventional engine fuel supply control devices simply supply a fixed amount of fuel during recovery and then perform fill pack control, so they are susceptible to changes in engine performance over time and changes in operating conditions. Environmental changes (
For example, the above-mentioned amount of fuel may deviate from the optimal air-fuel ratio during recovery due to variations in the characteristics of individual engines (for example, changes in air density due to altitude differences, changes in outside temperature, etc.), variations in the characteristics of individual engines, and even variations in fuel injection characteristics. There was a problem that drivability deteriorated.

For example, if more fuel than the optimal value is supplied, the air-fuel ratio will be controlled to be richer than necessary, resulting in high output, causing the engine to accelerate even though it is decelerating, causing so-called engine shock. . On the other hand, if less fuel than the optimum value is supplied, the engine will be controlled to be leaner than necessary, resulting in insufficient output, and in the worst case, a misfire will occur and the engine will stop.

(Purpose of the Invention) Therefore, the present invention corrects the recovery supply amount based on the combustion state of the engine so that it becomes the optimum value corresponding to the operating condition when the engine cut is canceled, and also corrects the recovery supply amount when the optimum value is reached. By learning and memorizing the amount and setting the recovery supply amount based on this learned value during the next recovery, the engine output at the time of recovery can be optimized to match the operating condition and torque fluctuations and output shortages can be avoided. The purpose is to prevent this and improve engine drivability.

(Structure of the invention) FIG. 1 is an overall configuration diagram for clearly explaining the present invention.

The air-fuel ratio detection means a detects the air-fuel ratio in the exhaust gas, and the combustion state detection means d detects the combustion state of the engine. The operating state detection means detects the operating state of the engine, and the twin cut signal generating means C outputs a twin cut signal when the engine is within a predetermined deceleration operating range. On the other hand, when the fuel cut is canceled, the storage means e corrects the fuel supply amount based on the combustion state of the engine to the optimum value corresponding to the operating condition, and also learns the fuel supply amount when the optimum value is reached. This learned value is memorized. The supply amount control means f performs a fuel supply cut when the fuel cut signal is output, and when the output of the fuel cut signal is stopped, reads a learned value of the fuel supply amount corresponding to the operating state from the storage means e, and based on this learned value. The fuel supply amount when canceling the unit cut is set, and when a predetermined time has elapsed since the unit cut is canceled, the air-fuel ratio detection means a
Feedbank control of the fuel supply amount is performed based on the output of the air-fuel ratio so that the air-fuel ratio becomes the target air-fuel ratio. Then, the fuel supply means g supplies fuel to the engine based on the output of the supply amount control means f, so that the engine output during recovery is appropriately controlled.

(Example) Hereinafter, the present invention will be explained based on the drawings.

2 to 7 are diagrams showing a first embodiment of the present invention, which is an example in which the present invention is applied to a vehicle equipped with a manual transmission.

First, to explain the configuration, in FIG. 2, 1 is an engine, intake air is supplied from an air cleaner 2 through an intake pipe 3 to each cylinder, and fuel is injected by an injector 4 based on an injection signal Si. The intake air flow rate Qa is detected by an air flow meter 5, and a throttle valve 6 in the intake pipe 3 is detected.
controlled by The opening Cv of the throttle valve 6 is detected by a throttle valve opening sensor 7, and the rotation speed N of the engine 1 is detected by a crank angle sensor 8.

Further, the engagement/disengagement state of the clutch (the path shown in the figure) is detected by a clutch switch 9, and the clutch switch 9 outputs a clutch signal Sc representing the engagement/disengagement state of the clutch. The throttle valve opening sensor 7, crank angle sensor 8, and clutch switch 9 constitute an operating state detecting means 10.

The oxygen concentration in the exhaust gas is detected by an air-fuel ratio detection means 11, and the air-fuel ratio detection means 11 is composed of a wide range air-fuel ratio sensor 12 and a measurement circuit 13. The air-fuel ratio detection means 11 measures the oxygen concentration in the exhaust gas in a wide range of air-fuel mixtures ranging from lean air-fuel ratios to rich air-fuel ratios, as will be described in detail later, and outputs a voltage signal Vi representing the current air-fuel ratio. Furthermore, in this embodiment, the air-fuel ratio detection means 11 also has a function as a combustion state detection means for detecting the combustion state of the engine 1 by detecting the air-fuel ratio. Signals from the air flow meter 5, throttle valve opening sensor 7, crank angle sensor 8, clutch switch 9, and air-fuel ratio detection means 11 are input to a control unit 14, and the control unit 14 includes a unit cut signal generation means and a memory. It has a function as a supply amount control means and a supply amount control means.

The control unit 14 includes a CPU 21, ROM 22, RAM 23, I10 port 1, as shown in detail in FIG.
-24 and a constant voltage circuit.

The constant voltage circuit δ is directly supplied with DC power from the battery nail, and the constant voltage circuit 25 constantly supplies a constant voltage (for example, 5 V) to the RAM 23. Therefore, RAM
The stored data of No. 23 is retained even after the engine is stopped. On the other hand, the constant voltage circuit hole is supplied with the above DC power via the ignition switch, and when the constant voltage circuit is in the ON position, the CPU 21,
A constant voltage is supplied to the ROM 22 and the I10 boat 24. Therefore, the control unit 14 starts operating when the ignition switch 4 is placed in the ON position. C
The PU 21 takes in necessary external data from the I10 port 24 according to the program written in the ROM 22, performs arithmetic processing while exchanging data with the RAM 23, and processes processed data as necessary.
- output to I10 port U. Signals from the sensors 5, 7, 8, 9, and 10 are input to the I10 port U, and an injection signal Si is output from the I10 boat 24. The ROM 22 stores calculation programs for the CPU 21, and the RAM 23 stores data used in calculations in the form of a map or the like.

Here, the wide-range oxygen sensor 12 as the wide-range air-fuel ratio sensor has a measuring circuit 13,
are each constructed as shown in FIG. In FIG. 4, the wide area oxygen sensor I2 includes an alumina substrate 32 with high electrical insulation properties in which a heater wire 31 is embedded, and a first partition plate 3.
3, the first solid electrolyte 34, the second partition plate 35, and the second
A solid electrolyte 36 is sequentially laminated, the alumina substrate 32, the first partition plate 33 and the first solid electrolyte 34 define an air introduction part, and the first solid electrolyte 34 and the second partition plate 3
5 and the second solid electrolyte 36 define a reference oxygen chamber 38. The first and second solid electrolytes 34 and 36 are mainly composed of oxygen ion conductive zirconium oxide, etc., and the second solid electrolyte 36 has a small hole 3 that communicates with the reference oxygen chamber 3 days.
9 is formed.

The first solid electrolyte 34 has a reference electrode 40 facing the atmosphere introduction part 33 and a measurement electrode 41 facing the reference oxygen chamber 38.
The first solid electrolyte 34, the reference electrode 40, and the measurement electrode 41 constitute a sensor element section 42, which are each provided by a printing process. Pump electrodes 43 and 44 are provided on the second solid electrolyte 36 by a printing process, facing the reference oxygen chamber 38 and the outside through which the exhaust gas flows, and these second solid electrolyte 36 and pump electrodes 43 and 44 are connected to the pump element. 45. the heater wire 31;
Reference electrode 40, measurement electrode 41, and pump electrode 43.
44 has lead wire 46.47.48.49.50.51
is connected to the atmosphere introduction part 37 as shown by the arrow AIR in the figure.
Atmosphere is introduced as shown in . The pump element section 45
A pump current 1p is supplied between the pump electrodes 43 and 44 from a current supply circuit to be described later, and oxygen ions move in the second solid electrolyte 36 in the opposite direction to the pump current 1p.

The amount of movement of this oxygen ion is proportional to the value of the pump current ip, and by controlling the pump current 1p, the reference oxygen chamber 38
can maintain the oxygen concentration at a constant target value. In this embodiment, the pump current rp is controlled so that the oxygen concentration in the reference oxygen chamber 38 becomes the oxygen concentration in the exhaust gas at the stoichiometric air-fuel ratio. The sensor element section 42 detects whether the oxygen concentration in the reference oxygen chamber 38 is the target oxygen concentration. That is, the sensor element section 42 generates an electromotive force E according to the oxygen partial pressure ratio between the measurement electrode 41 facing the reference oxygen chamber 38 and the reference electrode 40 facing the atmosphere introduction section 37. This electromotive force E suddenly changes when the oxygen partial pressure at the measurement electrode 41, that is, the oxygen concentration in the reference oxygen chamber 3B, is the oxygen concentration at the stoichiometric air-fuel ratio. The pump current r is controlled by the measuring circuit 13 shown in FIG.
It controls p.

In FIG. 5, the measuring circuit 13 includes a subtraction circuit 61, a current supply circuit 62, a current value detection circuit 63, and a resistor R. The output voltage Vs of the sensor element section 42 is input to the subtraction circuit 61, and the subtraction circuit 61 subtracts the target voltage Va from the output voltage Vs of the sensor element section 42 to obtain a difference value Δ.
V (ΔV=K (Vs Va), where K is a constant) is output to the current supply circuit 62. This target voltage Va is set to the output voltage of the sensor element section 42 when the oxygen concentration in the reference oxygen chamber 38 is the same as the oxygen concentration in the exhaust gas in stoichiometric air-fuel conditions. However, as described above, the output voltage of the sensor element section 42 suddenly changes when the oxygen concentration in the reference oxygen chamber 38 reaches the stoichiometric air-fuel ratio. Therefore, the target voltage V
When a is set to approximately the middle value of the suddenly changing voltage of the sensor element section 42, the difference value Δ■ between the target voltage Va and the output voltage Vs of the sensor element section 42 is determined by the current oxygen concentration in the reference oxygen chamber 38 and the theoretical empty space. It represents the magnitude of the difference between the fuel ratio and the oxygen concentration, that is, the magnitude of the difference between the current air-fuel ratio of the reference oxygen chamber 38 and the stoichiometric air-fuel ratio. The current supply circuit 62 uses this difference value Δ
A pump current Ip is supplied to the pump electrodes 43 and blades via the resistor R so that V becomes zero, that is, so that the oxygen concentration in the reference oxygen chamber 38 becomes the oxygen concentration at the stoichiometric air-fuel ratio. Therefore, the magnitude of the pump current Ip represents the magnitude of the difference between the current oxygen concentration in the reference oxygen chamber on the third day and the oxygen concentration at the stoichiometric air-fuel ratio.

Furthermore, oxygen flows into and out of the reference oxygen chamber 38 through the small hole 39 in proportion to the oxygen partial pressure ratio between the outside and the reference oxygen chamber 38, and the oxygen concentration in the reference oxygen chamber 38 changes. Therefore, the pump current rp corresponds to the amount of oxygen in the exhaust gas flowing in and out through this small hole 39, and by detecting this pump current rp, it is possible to detect the oxygen partial pressure ratio between the reference oxygen chamber 38 and the exhaust gas. can. That is, by detecting the value of the pump current Ip, the oxygen concentration in the exhaust gas can be detected, and the air-fuel ratio in the exhaust gas can be detected. The value of this pump current 1p is detected by the current value detection circuit 63 as a voltage drop across the resistor R, and is output as a voltage signal Vi.

Therefore, when expressed in terms of the equivalence ratio (λ, λ - current air-fuel pressure air-fuel ratio/stoichiometric air-fuel ratio), the pump current rp becomes zero at λ-1 and takes a negative value ( The direction of the current flowing from the pump electrode 44 to the pump electrode 43,
That is, the direction in which oxygen in the reference oxygen chamber 38 is released to the outside is defined as positive. ), it becomes a positive value when λ>1. As a result, the air-fuel ratio can be continuously measured over a wide range from a lean air-fuel ratio to a rich air-fuel ratio.

Next, the effect will be explained.

Generally, in feedbank control, even if the control amount (air-fuel ratio) changes due to disturbances (engine load, etc.), a device is operated to detect this, compare it with a target value, and cancel the deviation.

Therefore, although the control amount can be made to match the target value with high precision, the control takes time.

In particular, when the controlled object is an engine and the controlled variable is the air-fuel ratio, the dead time is relatively long, and there is a limit even if differential operation is used to speed up the response, for example.

Therefore, when a disturbance occurs, we immediately predict the change in the control amount.
A control method that sends a manipulated variable (fuel amount, etc.) to counteract this will result in a faster response.

Feedforward control uses this idea,
If the response of the controlled object to disturbance is calculated in advance and the manipulated variable is set before detecting the controlled variable, responsiveness can be significantly improved.

However, in the case of feedforward control, if the precision of the control value is poor, it is difficult to take advantage of its advantages.

By the way, the air-fuel ratio is not yet detected during the recovery period (it is difficult to detect the air-fuel ratio at the same timing as recovery, and air-fuel ratio detection involves a time delay), so the feedback control is used to detect the air-fuel ratio. It is difficult to control to the target value. For this reason, conventionally, the recovery supply amount Tr has been set to a constant amount in advance. Although this is a form of feedforward control, the control value does not necessarily correspond to the operating state at the time of recovery, resulting in poor control accuracy.

Therefore, in this embodiment, we focused on the point that in order to take advantage of the advantages of feedforward control, it is only necessary to increase the accuracy of the control value, and the feedforward control value (in this embodiment, this is calculated from the combustion state immediately after recovery). The accuracy of the control value is improved by learning the optimum value of the supply amount (corresponding to the supply amount Tr) and storing this as a learned value corresponding to the operating state at that time.

FIG. 7 is a flowchart showing a fuel supply amount control program written in the ROM 22, and in the figure, P1 to
P+9 indicates each step of the flowchart. This program is executed, for example, once every engine revolution.

This program is broadly divided into operating state determination flow UHF.
, feedback flow FBF.

Recover Flow RF and Twin Cant Flow-FCF
Consisted of. The operating state determination flow UHF determines in steps P to P7 which of the following states A to C the operating state of the engine 1 corresponds to. A-C
The status is determined based on the following conditions, and these A to C
Depending on the state, the flow shifts to feed batter flow FBF1, recovery flow RF, and twin cant flow FCF.

A state: Clutch is neutral (separated state) at P-4
When the throttle valve 6 is not fully closed at P, or when the elapsed time t after the recovery time exceeds the predetermined recovery time tr at P7. Such a state corresponds to when the engine l is not in a deceleration state or when the feed bank control becomes possible after recovery. If it is determined that the state is A, the flow shifts to feedback flow FBF.

B state: At P-4, the clutch is connected, at P, the throttle valve 6 is fully closed, at P6, the rotation speed N is less than the engine rotation speed Nc, and at P7, the elapsed time t after the recovery period When the condition that is less than the recovery time tr is satisfied. This state is when the fuel cut is canceled and the fuel supply is restarted, and at this time the fuel flow shifts to the fuel and bar flow RF.

C state: When the conditions that the clutch is connected at P-4, the throttle valve 6 is fully closed at P, and N>Nc at PG are satisfied. This state is when a twin cut is performed during deceleration, and at this time the vehicle shifts to a twin cut flow FCF.

In the feedback flow FBF, a target air-fuel ratio is first set in accordance with the operating state of the engine 1 in P8, and a voltage signal Vi representing the current air-fuel ratio is read in P9. Next, PIO determines the deviation of the current air-fuel ratio from the target air-fuel ratio (ΔA/F)<ΔA/
F = current air-fuel ratio - target air-fuel ratio), and if there is no deviation (ΔA/F) and both match, the basic supply amount Tp (e.g. , T
The final supply amount is determined as it is without correcting p=-Q/N (where K is a constant). On the other hand, when there is a deviation (ΔA/F) in PIO, the basic supply amount Tp is corrected in PI3 according to the direction and magnitude of the deviation (ΔA/F) so that the current air-fuel ratio matches the target air-fuel ratio. Ship
Proceed to H. As a result, the air-fuel ratio is feedback-controlled and accurately maintained at the target air-fuel ratio.

Next, when the engine 1 is in the C state, the flow shifts to a twin cut flow FCF, and a twin cut is performed in step P13. Therefore, generation of unburned gas during deceleration can be prevented and fuel can be saved.

In the recovery flow RF, first, the learned value of the area corresponding to the current operating state is read out from the learned value of the recover supply amount Tr learned up to the previous time in the PI3, and the recover supply amount Tr is determined based on this learned value. . This recovery supply amount Tr corresponds to a control value when performing feedforward control as supply amount control during recovery, but as it is determined by incorporating the concept of learning control as described below, the control value is High accuracy.

In other words, as mentioned above, feedforward control can make the response extremely fast, but if the precision of the control value is poor, this advantage cannot be utilized (the response may deviate from the target). controllability is poor).

Therefore, we adopted the concept of learning control to control the control amount (air-fuel ratio).
By learning the control value when the value matches the target value, the accuracy of the feedforward control value is made extremely high.

Here, the concept of the present invention, which incorporates the advantages of feedforward control and learning control, can be summarized as follows.

First, when performing feedforward control, it is determined whether there is a deviation from the target value based on the output of the air-fuel ratio detection means 11, and if there is a deviation, feed is performed to eliminate this deviation in the next routine. Correct the forward control value. Note that when this deviation cannot be corrected at once, it is corrected sequentially within the recovery time tr or at each recovery time. Then, the recovery supply amount Tr, that is, the feedforward control value is made to match the target value, and the control value at this time is learned as the optimum value corresponding to the operating state at that time. Since this learned value is a value when the control amount=target value, its accuracy is extremely high, and it can be regarded as an optimal value that always compensates for changes in the device over time. This learned value is stored and held until the next rewriting timing. In this way, learning is performed for a wide range of changes in the operating state and operating conditions at the time of recovery, and the learned values in the corresponding area are rewritten and stored with the latest data.

In this way, by skillfully taking advantage of the advantages of each control and repeating the above process, the precision of the feedforward control value is made high.

Now, in order to perform the above-mentioned process, in this embodiment, the PI
The voltage signal Vi representing the air-fuel ratio at the time of recovery is read at S, and it is determined at Pl whether this air-fuel ratio is an appropriate value corresponding to the operating state at the time of recovery. If the value is not appropriate, recover the supply amount T so that the air-fuel ratio becomes appropriate using PIQ.
Correct the value of r. This correction result will be confirmed in the next routine. Then, within the recovery time tr, such a routine is repeated until an appropriate value is reached.

On the other hand, if the air-fuel ratio is an appropriate value at P+6, Pu8 learns the glue cover supply amount Tr at this time as the optimum value corresponding to the current operating state, and rewrites the learned value in the corresponding region.

Therefore, an optimal amount of fuel is always supplied during recovery, and the engine output corresponds to the operating state.

As a result, it is possible to prevent torque fluctuations and output shortages during recovery, thereby improving drivability. In addition, since the recovery supply amount Tr is always determined by the latest learned value, the engine output at the time of recovery is optimized regardless of variations in various characteristics or environmental changes in operating conditions as pointed out in the conventional example. be able to.

FIG. 8 (al to fal are timing charts for supply amount control.

When the vehicle is decelerated at timing t1 as shown in FIG. 8 (al) and enters the C state (see FIG. 8 (e)), fuel cassette is started as shown in FIG. As shown in C1, the air-fuel ratio gradually shifts to the lean side from timing t□, and the inside of the exhaust pipe is filled with atmosphere, and the torque decreases and becomes negative as shown in dl in the same figure. Torque refers to the torque that cannot be effectively removed externally from the output shaft of the engine, and refers to the rotational torque that overcomes the friction loss inside the engine and allows the engine to continue to rotate.For example,
When driving downhill, etc., the vehicle may be operated with a negative torque that is smaller than the torque required for idling. Next, when the B state is reached at timing t2, the fuel cartridge is stopped and the recovery supply amount Tr is reduced, as shown in FIG.
of fuel will be supplied. This recovery supply amount Tr is a value obtained by learning the supply amount up to the previous time, and is determined as the optimum value corresponding to the operating state at timing t2. Therefore, as shown in FIG. 8(C), the air-fuel ratio returns smoothly, and as shown at +d+ in the figure, the torque gradually increases without fluctuation and while maintaining a negative state. As a result, drivability during recovery can be improved. Then, when a predetermined recovery time tr has elapsed from timing t2 and reaches timing t3, the A state is determined and feedbank control of the air-fuel ratio is started to accurately control the air-fuel ratio to the target air-fuel ratio.

9 to 11 are diagrams showing a second embodiment of the present invention, in which the combustion state detection means and the contents of the cover flow RF are changed.

That is, in this embodiment, as shown in FIG. 9, a combustion monitoring sensor 71 serving as combustion state detection means is attached to a cylinder head 73 as a washer for a spark plug 72.

The combustion monitoring sensor 71 is molded as a washer with a piezoelectric element 74 sandwiched between electrodes 75 and 76 as shown in FIG. is spark plug 7
2 on the piezoelectric element 74, and at this time, the piezoelectric element 7
The combustion state is monitored from the voltage value generated at 4.

Figure 11 shows the beam cover flow RF, and in the figure P
. . . ~Px5 indicates each step of the flowchart. First, the learned value of the region corresponding to the current operating state is read out from the learned values of the learned air-fuel ratio learned up to the previous time in Pyu 1, and the recovery supply amount Tr is determined based on this learned value.

Note that the learning air-fuel ratio read this time corresponds to the target air-fuel ratio that is optimal for the current operating condition, and since learning control is performed, its accuracy is extremely high as in the first embodiment. Next, in step P, it is determined whether or not the torque generated at the time of recovery is appropriate. If not, in step P3, the value of the recovery supply amount Tr is corrected so that the torque becomes appropriate.

On the other hand, if the torque is appropriate at Pl, the voltage signal Vt representing the air-fuel ratio at the time of recovery is read at PH. And P
At s, the air-fuel ratio at this time is learned as the optimum value corresponding to the current operating state, and the learned value in the corresponding region is rewritten and stored as the learning air-fuel ratio.

Therefore, in this embodiment, since the engine torque during recovery is precisely monitored, the recovery supply amount Tr is determined more precisely than in the first embodiment, and the drivability can be further improved.

(Effects) According to the present invention, the engine output when the fuel cartridge is released can be optimized to correspond to the operating condition, and torque fluctuations and insufficient output can be prevented, thereby improving engine drivability.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of the present invention, FIGS. 2 to 7 are diagrams showing a first embodiment of the invention, FIG. 2 is a schematic configuration diagram thereof, and FIG. 3 is a circuit configuration diagram of its control unit. , FIG. 4 is a sectional view of the wide range oxygen sensor, FIG. 5 is a circuit configuration diagram of its measurement circuit, FIG. 6 is a diagram showing the relationship between the pump current of the air-fuel ratio detection means and the air-fuel ratio, and FIG. 7 is a flowchart showing the fuel supply control program, FIG.
(e) is a timing chart for explaining the effect, and FIGS. 9 to 11 are diagrams showing a second embodiment of the present invention,
Figure 9 is a sectional view of the installation of the combustion monitoring sensor, and Figure 10 (
al is a plan view of the combustion monitoring sensor, FIG. 10 (bl is a sectional view taken along the line X-X in FIG. 10(a), and FIG. 11 is a flowchart showing the recovery flow. 1--1 engine; 4-----Fuel supply means, 10-----Operating state detection means, 11-----Air-fuel ratio detection means, 14-----Control unit (fuel cartridge signal generation means, storage means, Supply amount control means) 71 ---- Combustion state detection means. Agent Patent Attorney Ugagun Part Figure 9 Figure 10 (0) (b)

Claims (1)

[Claims] a) air-fuel ratio detection means for detecting the air-fuel ratio in exhaust gas; b) operating state detection means for detecting the operating state of the engine; and C) when the engine is within a predetermined deceleration operating range. a fuel cartridge signal generation means for outputting a fuel cartridge signal; d) a combustion state detection means for detecting the combustion state of the engine; and e) when the fuel cartridge is released, the fuel supply amount is adjusted to correspond to the operating state based on the combustion state of the engine. a storage means for correcting the fuel supply amount to the optimum value, learning the fuel supply amount when the value is the optimum value, and storing this learned value; When it is stopped, the learned value of the fuel supply amount corresponding to the operating state is read from the storage means, and based on this learned value, the fuel supply amount when canceling the fuel cartridge is set. a supply amount control means for feedback controlling the fuel supply amount so that the air-fuel ratio becomes a target air-fuel ratio based on the output of the fuel ratio detection means; and g) a fuel supply for supplying fuel to the engine based on the output of the supply amount control means. A fuel supply control device for an engine, comprising: means;