JPH04128524A - Fuel controller of engine - Google Patents

Abstract

PURPOSE:To prevent hesitation caused by flame-out due to fuel leakage of an ignition plug and flame-out itself at the acceleration initial stage and acquire smooth acceleration by carrying out capacity increase correction of fuel at the time of acceleration by means of capacity increase of fuel injection capacity only to a side port in a suction three-valve engine. CONSTITUTION:A suction air three-valve engine is provided with three suction ports respectively and individually open to a combustion chamber along the rough crank shaft direction for each cylinder, and a suction valve is respectively arranged on an opening part to the combustion chamber of each of the suction ports and simultaneously an ignition plug is arranged in the rough central part on the top part of the combustion chamber. In the above constitution, fuel is injected to each of the suction ports by a fuel injection means 51. Subsequently, the state of acceleration of the engine is detected by an acceleration detection means 54. Additionally, the fuel injection means 51 is controlled by a control means 52 so that it receives output of the acceleration detection means 54 and increases and corrects only the fuel injection capacity only to both side ports on both sides out of the three suction ports at the time of acceleration.

Description

Detailed Description of the Invention (Industrial Application gF) The present invention is an intake three-valve construction having three intake ports; 2S;
The present invention relates to a fuel control device, particularly one that injects and supplies fuel.

(Prior Art) Conventionally, as a multi-valve fuel control device having a plurality of intake valves for each cylinder, three intake valves each independently opening into a combustion chamber are disclosed, for example, in Japanese Utility Model Application Publication No. 131/1983. It is equipped with two intake ports and three intake valves corresponding to each intake port, and one fuel injection valve injects fuel to the center port in the middle of the three intake ports, and an auxiliary fuel injection valve that injects fuel to the site ports on both sides. However, during low-load operation of the engine, only the main fuel injector is operated and fuel is supplied only from the center port, thereby increasing the degree of stratification within the combustion chamber.1. a
There is no known system in which the main fuel injection valve and the auxiliary fuel injection valve are operated together during load operation to supply fuel 4 from the three intake ports, thereby forming a uniform mixture of irises. There is.

(Problem to be solved by the invention) By the way, the so-called polyvalent enine as described in the above publication
Due to the configuration of the valve mechanism, the intake valves and exhaust valves are arranged approximately along the camshaft direction, that is, the crankshaft direction, on the combustion chamber side and the other side, respectively, so that each of the corresponding independent intake ports is arranged. The openings of the exhaust ports and the combustion chambers are also lined up in the same manner. Therefore, especially for intake valves with 3 valves, that is, 3 intake ports, the center port of the 3 intake ports is arranged so that it intersects with the center of the cylinder bore on the extension line toward the combustion chamber side. There are many cases.

Furthermore, in a multi-valve engine, in view of the arrangement of intake and exhaust valves and combustibility as described above, the ignition plug is generally disposed approximately at the center of the top of the combustion chamber, that is, near the center line of the cylinder bore. Therefore, in the three-valve intake engine, the fuel injected and supplied to the central center port tends to collect near the spark plug after flowing into the combustion chamber.

Further, since the negative E1 generally increases suddenly when the engine accelerates, a notch air-fuel ratio is required to maximize the engine torque, and an increase in fuel is corrected. In this case, at the beginning of acceleration, that is, immediately after the accelerator is pressed, the amount of intake air increases by e from the steady state up to that point, or the corresponding fuel supply is slightly delayed, and the air-fuel ratio changes over time. Because it is in a leaky state, combustibility tends to deteriorate.

For this reason, when increasing the amount of fuel during acceleration in the above-mentioned 3-valve intake engine, the fuel 1 to 1 flowing into the combustion chamber from the center port tends to collect near the spark plug, so the amount is increased. When fuel flows in from the ignition plug, more fuel collects near the spark plug, and especially fuel that forms a wall flow and travels from the center port into the combustion chamber is easily transmitted to the ignition valve, wetting the spark plug and causing a misfire. This further worsens the combustibility (ignitability) in the early stages of acceleration, when combustibility tends to deteriorate, and causes so-called "strange reeds" during acceleration, which can lead to accidents.

The present invention has been made in view of the above points, and its purpose is to prevent hedging during acceleration due to wetting of the spark plug when correcting the increase in fuel amount during acceleration in a three-valve intake engine. The second thing is to prevent acceleration and obtain smooth acceleration.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, when correcting the increase in fuel amount during acceleration in an intake 3-valve engine, a control μR is added to the increase in fuel to the center port; ing.

Specifically, the solution taken in the invention of claim (1) is that each cylinder is provided with three intake ports that open into the combustion chamber independently along the direction of the crankshaft, and the combustion of each intake port is The present invention is intended for a three-valve intake engine in which an intake valve is disposed at each opening to the chamber, and a spark plug is disposed approximately at the center of the top of the combustion chamber. Then, as shown in FIG. 1, fuel is injected into each of the intake ports. −
1 injection means 5], an acceleration detection means 54 that detects the acceleration state of the engine, and an output of this υ[] speed detection means 54, and upon acceleration, fuel is injected to the sight boats on both sides of the three intake ports. The control means 52 for controlling the fuel injection means 51 so as to increase only the quantity is configured to perform QK.

In addition, in the invention of claim (2), instead of the control means 52 in claim (1), the output of the acceleration detection means 54 is received, and during acceleration, the amount of fuel injection to the three intake ports is corrected to increase. , and the fuel injection means 51 is configured to delay the start of increase in the amount to the central sweater port among the three intake ports than the start of increase in the amount to the side ports on both sides thereof.
The configuration includes a control means 5'3 for controlling.

Furthermore, in the invention of claim (3), in claim (2), the control-T' stage 53 is configured to extend the delay time for starting the increase in the amount to the center port as the degree of acceleration increases. .

(For A') With the above configuration, in the invention of Claim (1), the control means 52 performs the increase correction of the fuel 11 injection at the time of acceleration only to the sight board). When the air-fuel ratio becomes lean due to a delay in supply response, which tends to result in poor combustibility, the increased amount of fuel will not flow into the combustion chamber from the center port and wet the spark plug, preventing misfires and accelerating. Prevents stiffness and provides smooth acceleration.

Further, in the invention of claim (2), the control means 53
During acceleration, the increase in fuel 11A m is corrected at the three intake ports, or the start of increase to the center port is delayed from the start of increase to the side boat, so the air-fuel ratio at the beginning of acceleration is in a lean state. When combustibility tends to deteriorate, the increased amount of fuel will not flow into the combustion chamber from the center port and wet the spark plug, preventing misfires and preventing hesitation during acceleration. increase; by the time correction starts late,
At the beginning of acceleration, the delay in the response of the produced fuel to the intake air is eliminated, the deterioration of combustibility is improved, and the influence of spark plug salt on the deterioration of combustibility is suppressed. On the other hand, after acceleration when the engine is under high load and output is required, the amount of fuel is increased at one intake port by increasing the amount of correction to the center port, improving the air utilization rate and increasing the output. This results in improved responsiveness and smoother acceleration.

Furthermore, in the invention of claim (3), the delay time for starting the increase in the amount to the center port is extended as the degree of acceleration increases. If the amount of delay is large and the air-fuel ratio stays flat for a long time at the beginning of acceleration, the start of increasing the amount to the center port will be delayed accordingly, and the spark plug will be adjusted more accurately depending on the acceleration state. In addition to preventing misfires due to salt leakage and hesitation at the beginning of acceleration, the air utilization rate at the center port after acceleration is reduced by white clay.
As a result, the output is improved and the response is improved, resulting in smoother acceleration with the TI.

(Embodiment) Hereinafter, FIGS. 2 and 3, which explain an embodiment of the present invention based on the drawings, illustrate an in-line four-cylinder engine with three intake valves equipped with a fuel control device according to an embodiment of the present invention. show. These figures show only one cylinder as a representative, or the other cylinders have the same configuration.

In these figures, 1 is the engine body, 2 is the printer's block, 3 is the printer's head which is joined to the two sides of the cylinder block 2, and 4 is the cam installed on the cylinder block 3. It's l\unong. A cylinder 5 is formed in the cylinder block 2, and a piston 6 is slidably inserted directly into the cylinder 5. Further, a combustion chamber 7 is formed within the cylinder 5, which is partitioned by two inclined walls 7a and 7b on the lower surface of the cylinder head 3 and the surface around the piston 6.

On the left side of the cylinder bore of the cylinder head 3, there are three independent first to third intake boats 8 that guide fresh air into the cylinder 5. 9. There are 10.

The first to third intake boats 8 to 10 each open at one end in the left inclined wall 7a of the combustion chamber 7, open at the other end in the left side wall of the cylinder head 3, and converge into one intake port 11. has been done.

The second intake boat (center port) 9 in the center is arranged so as to cover the center of the cylinder bore on its extension, and the first and third intake boats (side ports) 8.1
0 stands for both sides of the center port 9 in the crankshaft direction (
“They are arranged in rows.

Furthermore, on the right side of the cylinder bore of the cylinder head 3, there are two independent exhaust boats 12 that guide the exhaust gas inside the cylinder 5 to the outside.
．． There are 13. This independent exhaust bow) 12.1
One end of each of the exhaust ports 3 is opened in the right side inclined wall 7b of the combustion chamber 7, and the other end is assembled into one exhaust boat 4 on the right side wall of the cylinder head 3 and opened in the right side wall. Furthermore, the openings of the two independent exhaust boats 12 and 13 to the combustion chamber 7 are aligned in the crankshaft direction.

The above-mentioned Nrinida head 3 has the first to third intake bottoms 8 to]
Three first to third intake valves 1.5, 16.17 are provided corresponding to () to open and close the combustion chamber side openings of the first to third intake boats 8 to 10, respectively. Each intake valve 1
5 to 17 have an umbrella-shaped valve head disposed in the opening and a valve stem extending upward from the valve head, and the valve stem slides onto the cylinder head 3. Move freely in the bush 1
It is placed on the floor and can be moved up and down. These intake valves 1
5-] At the end of the valve shaft of 7 is a disc-shaped slot 11 and a seat 18.
, 18. 18 is installed, and this spring seat 18
, 1.8.18 and the cylinder head 3, valve springs 19, 19.19 are respectively compressed, and the spring force l causes each of the first to third intake valves 15 to 7 to move upward, In other words, it is biased in the valve closing direction. The intake valves 15 to 7 extend in the left side of the cam housing 4 in the crankshaft direction (cylinder row direction), and each of the first
~Three intake cams corresponding to the third intake valves 15 to 17",
An integrally formed intake camshaft 2] is provided. Each intake valve] 5 to 17 is connected to the intake camshaft 21 or the crankshaft (not shown).
), the intake cam 20.20
．． 20, and one end of each swing arm 23 is supported by a hydraulic lash adjuster 22, 22.22,
23. It is driven to open and close at a predetermined timing via 23.

In addition, there are two ports that correspond to the independent exhaust ports 12.13 and open and close the combustion chamber side openings of the independent exhaust ports 12.13, respectively.
A full exhaust valve 24.25 is provided. This exhaust valve 2
4.25 is a drive mechanism having the same configuration as each of the intake valves 15 to 17 described above.

That is, the exhaust valves 24 and 25 are arranged in an umbrella-shaped valve head or in the above-mentioned opening, and are slidably fitted into the cylinder head 3 at a valve shaft extending upward from the valve head. It is movable and is compressed between the spring seat 26.26 attached to the end of the valve shaft and the cylinder head 3! <It is biased in the valve closing direction by the spring force of the lub spring 27.27. An exhaust-only camshaft 28 is disposed above the exhaust valves 24, 25 on the right side of the cam 1 housing 4 in parallel with the intake-only force shaft 21. The exhaust valves 24 and 25 are rotatably driven by the exhaust-only camshaft 27 or the crankshaft, so that two exhaust cams 2g integrally formed with the exhaust-only camshaft 28,
2g, each end is a hydraulic lash adjuster 22
．． It is driven to open and close at predetermined timing via swing arms 23, 23 supported by 22.

Furthermore, there are plug holes 30 or 1 in the cylinder head 3 and cam I\Using 4 above the combustion chamber 7! 'Through.'

A dot large plug 3 is provided in this plug hole 30.
The combustion chamber 717j is mounted with its ignition point 31a facing approximately the center of the combustion chamber 717j.

An intake passage 32 is connected to the left side wall of the cylinder head 3 so as to communicate with the intake port.

This intake passage 32 includes, in order from the upstream side, a throttle valve 33 for adjusting the amount of intake air, an overhead tank 34 for absorbing intake pulsation, and a sight board 1 as an injection means 5. A site injector 35 for injecting and supplying fuel to the 8 and][] and a center injector 36 for injecting and supplying fuel to the center port 9 are provided.

As shown by the dashed line in FIG. It has a small nozzle that is disposed at the connection part of the intake passage 32 to the intake port 11 on the downstream side and injects fuel only into the center port 9, and the operation of both of them is controlled by the control unit 50.

In addition, 1. Exhaust port 14 is on the right side wall of /rigoda head 30.
The υll communication path 37 is connected so as to communicate with the υll communication path 37.

Furthermore, in FIG. intake passage 32
43 is a water temperature sensor that detects the temperature of the engine cooling water inside the water jacket 2a of the cylinder block 2; 44 is a water temperature sensor that is installed in the distributor 38 and detects the crank angle from the rotation of the distributor 37 (two pairs); Crank angle sensor, 4
Reference numeral 5 denotes a rotational speed sensor as a rotational speed detection means for detecting the engine rotational speed, and 46 an accelerator pedal position sensor that detects the amount of depression of the accelerator pedal 39, that is, the accelerator opening degree.The output signals of these sensors are as follows. It is input to the control unit 5 [1].

Next, fuel injection control in the control unit 50, that is, the side injector 35 and the center injector 3
The operation control of No. 6 will be explained.

As is well known, in normal steady operating conditions, the fuel 1-1 from the site injector 35 and the center injector 36 is determined based on the map based on the operating conditions at that time, such as the engine speed and load. Injection 2 is calculated, the pulse width of the corresponding actuation signal is determined, and at a predetermined injection timing, the actuation signal with the above pulse width is sent from the site injector 35 and the center injector 36 to the site port 8, 10 and the center port 9, respectively. Fuel or injection supplied. Furthermore, when the accelerator pedal is depressed and the acceleration state is entered, the flowchart shown in Fig. 4 is executed to perform fuel injection control (4) and fuel (2) during acceleration separately from the fuel 1 injection control in the fixed-rate operation described above. Control based on 1. is performed. That is, in the figure, after the start, in step S, the intake negative pressure PB corresponding to the engine load and the accelerator differential value G that determines the degree of acceleration of the engine speed R1 are read as operating conditions.

Here, the accelerator differential value G is a value obtained by calculating the amount of change in the accelerator opening from the output signal of the accelerator pedal position sensor 46 and differentiating this with respect to time. Next step S2
It is determined whether the engine is in an acceleration state or not. This is fixed depending on whether it is larger than the accelerator @ minute value G or the preset accelerator differential value.
If so, it is determined that the vehicle is not accelerating, and the process returns to step S1.

On the other hand, if G > k (YES), it is determined that the time is accelerating, and the process proceeds to step 83 and subsequent steps, and an increase correction of the fuel injection amount during acceleration is executed. First, in step S3, the fuel 11 increase during acceleration is calculated as the above-mentioned accelerator differential 1c.

It is calculated based on a map from the intake negative pressure Pa and the engine rotational speed R, and the corresponding pulse width f of the activation signal of the side injector 35 is determined. Next, the process proceeds to step S4, and the crank angle C= at which the temporary injection of the increased amount of fuel from the side injector 35 ends is determined. This is determined by calculating the amount of advance of the crank angle during the period required for the injection of the pulse width f, and adding this to the crank angle at the time when the acceleration that starts the temporary injection is detected. Then, the process proceeds to the next step S5, in which the side injector 35 starts temporary injection of the increased amount of fuel during acceleration in response to the activation signal having the pulse width f. Then, in step S6, it is determined whether the crank angle CA has reached the crank angle CE at which the temporary injection of the side injector 35 ends. Here, if No, the crank angle cE has not yet reached the end of injection, the injection continues and waits for the crank angle to advance to the end of the injection crank angle CE. When the crank angle CA reaches the crank angle CE at which the injection ends (YES), the process advances to step S7, where the temporary injection from the side injector 35 is ended, and the process returns.

In the above flow, through steps S1 and S2,
It constitutes an acceleration detection means 54 that detects the acceleration state of the engine, receives the output of the acceleration detection means 54 in steps S3 to S7, and when accelerating, the three intake ports 8, 9.1
A control means 52 is configured to control the side injector 35 so as to increase only the amount of fuel injected into the site ports 8 and 10 on both sides.

Therefore, in the above embodiment, when the acceleration state of the engine is detected, the acceleration fuel increase correction is performed by the site injector 35.
Since this is performed only by temporary injection from the engine, the increased amount of fuel during acceleration flows only into the side ports 8 and 10. Therefore, when the air-fuel ratio at the beginning of acceleration is temporarily lean and combustibility tends to deteriorate, the increased amount of fuel flows into the combustion chamber 7 from the center port 9 and wets the ignition point 31a of the spark plug 31. It is possible to prevent misfire due to smoldering of the spark plug, prevent hesitation caused by misfire during acceleration, and achieve smooth acceleration.

The next FIG. 5 is a flowchart showing control of fuel increase during acceleration, which is different from the above embodiment, and will be explained. In the same figure, after starting, the intake negative pressure PB, engine speed R, and accelerator differential value G are read as operating conditions using the steering knob Q+, and it is determined whether the engine is in an accelerating state using the steering knob Q2. . These steps Q1 and G2 are
This is the same as steps S1 and S2 in FIG. 4 above. Then, if YES in step Qco, which is during acceleration, proceed to step Q3, and temporarily inject the amount of fuel increased during acceleration from the site injector 35; The pulse width fS of the operation signal of the side injector 35 corresponding to the calculation is calculated based on the value R and the pulse width fS of the operation signal of the side injector 35 is determined. Next, proceed to step Q4,
Temporary injection from the site injector 35 is started in response to the activation signal having the pulse width fs described above. And the next step
The crank angle CSE at which the temporary injection of the site injector 35 ends is determined using the knob Q5. This is done by calculating the amount of advance of the Kranich angle during the period required for the injection where r<Rus width fS, and adding it to the crank angle at the time when the acceleration of the side injector 35 to start injection is detected. and ask. Next, the process proceeds to step Q6, where it is determined whether or not the acceleration determination made in step Q2 was also in the acceleration state last time. In other words, this is to determine whether a new acceleration state has been detected this time, or whether the acceleration has continued from the previous time.

Here, if the answer is NO since the previous acceleration state was not present, that is, if the current acceleration state is newly entered, the process proceeds to step Q7, and the delay time Δt for the start of temporary injection corresponding to the increased amount of acceleration from the center injector 36 is set. do. This is calculated based on a map from the value of the accelerator differential value G, and the larger the value of G, that is, the larger the degree of acceleration, the more the delay time △t
is designed to take a large value. Then, the process advances to the next step Q8. On the other hand, if the answer in step Q6 is YES, which was the previous acceleration state, that is, if the acceleration is continuing, the process directly advances to step Q8. And step Q
In step 8, it is determined whether or not the set delay time Δt has elapsed. Here, if NO again, the delay time Δt has not elapsed, the process advances to step Q9, and the crank angle CA
It is determined whether CSE has reached the crank angle CSE at which the temporary injection of the site injector 35 ends. At this point, if the crank angle C5E has not yet reached the end of injection, the process returns to step Q8. On the other hand, if the answer is YES since the crank angle CSE has reached the end of the injection, the process proceeds to step QIO, where the temporary injection of the side injector 35 is ended and the process returns. On the other hand, if it is YES in step Q8 that the delay port 3 time Δt has elapsed, the process proceeds to step Qn, and the temporary injection amount corresponding to the acceleration fuel increase from the center injector 36 is set to the accelerator differential value G5, the intake negative pressure PB, Calculate from the engine rotation speed R based on the map, and the center injector 3
Determine the pulse width fc of the actuation signal No. 6.

Next, the process proceeds to step Qν, and the crank angle CCS at which the temporary injection from the center injector 36 is started is determined. This is the delay time t in the crank angle when the first acceleration is detected.
It is determined by adding the crank angle advance angle 2 required for the elapsed time. Next, proceed to step Q+3, and the center injector 36
Kranik angle cc E ) f at the end of the temporary injection: Determine. This is because the above-mentioned crank angle Ccs at the start of injection is 1. It is determined by adding up the Clark angle advance amount for the period required for the injection of the pulse width fC. Then, in the next step QI4, the crank angles C5E, Ces, and CCE determined above are compared to determine the order in which the crank angles are rotated. Then, in the next bet 77' Q I5, determined in step Q- above,
Each crank angle C9ECC5 according to the order of rotation angle.
, CCE, the end of the temporary injection of the side injector 35 (CSE), and the start of the temporary injection of the sensor 36 (Ccs), respectively.

Se:, Tie＞” ;'-? End of temporary injection of Kuta 36 (
Return CcF) to length i[.

In -170-, steps Q1 and Q? Acceleration detection means 54 detects the acceleration state of Uni, :.
Configure and...! The output of the acceleration detection means 54 is received by the output ports Q3 to Q+s, and the three intake ports) 8 are detected during acceleration.
．． 9. ] Correct the increase in the amount of fuel 4 injection to the CI, and start increasing the amount to the center boat 9 in the center among the three intake ports 8, 9, and 10, and start increasing the amount to the side ports 8 and 10 on both sides. The control means 53 for controlling the side injectors 35 and the center injector 36 is configured such that the delay time is extended as the degree of acceleration increases.

Therefore, in the embodiment shown in FIG. 5, when the engine is in an acceleration state or acceleration is detected, the acceleration fuel increase correction is first performed by temporarily injecting an increased amount of acceleration fuel from the site engine shector 35. , a delay time t is set for the end of the temporary injection of the acceleration fuel of the center injector 36 according to the degree of acceleration at that time, and this delay time t
is lengthened as the degree of acceleration increases. Then, after this delay time has elapsed, the central controller 36 also starts a temporary injection. Therefore, at the beginning of acceleration, the increased amount of fuel during acceleration flows only into the side ports 8 and ]0 and does not flow into the center port h9, so the air-fuel ratio may temporarily change due to a delay in the response of fuel supply at the beginning of acceleration. 1; When the condition is such that combustibility tends to deteriorate, the increased amount of fuel will not flow from the sensor board 9 into the combustion chamber 7, and the ignition point 31a of the spark plug 31 will be kept away from the center port 9. Since the increased amount of fuel 1, 1 does not get wet, it is possible to prevent a misfire due to smoldering of the ignition plug, and it is possible to prevent hesitation caused by a misfire at the beginning of acceleration. Furthermore, if the response delay in fuel supply at the beginning of acceleration is resolved and the deterioration of combustibility is improved, the deterioration of combustibility caused by wetting the spark plug due to the increased amount of fuel will be suppressed, and conversely, the deterioration of combustibility due to the increased amount of fuel will be suppressed, and conversely, the deterioration of combustibility will be suppressed. In the second half of acceleration when the output is required, temporary injection of the additional acceleration fuel from the center injector 36 is started after the delay time t or i, so the three intake ports h8 and 9.10 By increasing the amount of fuel, the air utilization rate can be improved, which can increase output, which can improve response and provide smoother acceleration.

In particular, the delay time t is extended as the degree of acceleration increases, so when the degree of acceleration is large, that is, a sudden increase in the amount of intake air causes a response delay of the fuel supply to increase, resulting in a delay in the initial acceleration. When the air-fuel ratio remains lean for a long time, the center injector 36
This means that the start of the temporary injection will be delayed, making it possible to more accurately prevent misfires due to wet spark plugs depending on the acceleration state, while improving response and achieving smooth acceleration.

(Effects of the Invention) As explained above, according to the engine fuel control device of the invention of claim (1), in an intake three-valve engine, an increase in fuel during acceleration; -4
Since the injection is increased, it prevents misfires due to the fuel temperature of the spark plug when the combustibility worsens in the early stages of acceleration.
It is possible to prevent hesitation caused by misfire at the beginning of acceleration and obtain smooth acceleration.

Further, in the invention of claim (2), the fuel increase correction is performed by increasing the fuel injection amount to the three intake ports during acceleration, but the increase in the fuel injection amount to the center boat is started from the side port. Since the fuel injection is delayed from the start of the increase in fuel injection, when combustibility tends to deteriorate in the early stages of acceleration, misfires due to wetting of the spark plug are prevented, and hesitation caused by misfires in the early stages of acceleration is prevented. At the same time, in the second half of acceleration, the air utilization rate is improved to increase output and response, resulting in smoother acceleration.

Furthermore, in the invention of claim (3), the delay time for starting fuel increase correction to the center port during acceleration in claim (2) is extended as the degree of acceleration increases. When the period of deterioration of combustibility in the early stages of acceleration becomes longer, the start of adding more personnel to the center port is delayed in response to this, making it possible to perform more precise control according to the acceleration state and prevent misfires. In addition to preventing this, it is possible to improve response and obtain smoother acceleration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention. 2 to 4 show embodiments of the present invention, and FIG.
- plane perspective view, Figure 3 is a sectional view taken along the il line in Figure 2;
FIG. 4 is a flowchart showing control in control uni-soto. FIG. 5 shows another embodiment of the present invention, and is a flowchart showing control in the control unit. 1... Engine body 7 - Combustion chamber 8... First intake port (side boat) 9... Second
Intake port (center port) 10...Third intake port (side port) 31...Spark plug 35 Side injector (fuel injection means) 36...
Center injector (fuel injection means) 46...Accelerator pedal position sensor 50...Control unit 51...Fuel injection means 52.53...Control means 54...Acceleration detection means

Claims (3)

[Claims] (1) Three intake ports that open into the combustion chamber independently are provided for each cylinder approximately along the crankshaft direction, and an intake valve is provided at the opening of each intake port to the combustion chamber. In addition, in the three-intake valve engine in which the spark plug is disposed approximately at the center of the top of the combustion chamber, there is provided a fuel injection means for injecting fuel into each of the intake ports, and an acceleration detection means for detecting an acceleration state of the engine. and control means for receiving the output of the acceleration detection means and controlling the fuel injection means so as to increase the amount of fuel injected only to the side ports on both sides of the three intake ports during acceleration. Features: Engine fuel control device. (2) Each cylinder is provided with three intake ports that open into the combustion chamber independently along the direction of the crankshaft, and an intake valve is provided at the opening of each intake port to the combustion chamber. In addition, in the three-intake valve engine in which the spark plug is disposed approximately at the center of the top of the combustion chamber, there is provided a fuel injection means for injecting fuel into each of the intake ports, and an acceleration detection means for detecting an acceleration state of the engine. , upon receiving the output of this acceleration detection means, increases the amount of fuel injected into the three intake ports during acceleration, and starts increasing the amount of fuel to the center port of the three intake ports to the side ports on both sides thereof. A fuel control device for an engine, comprising a control means for controlling the fuel injection means so as to delay the start of increase in the amount of fuel. (3) The fuel control device for an engine according to claim (2), wherein the control means extends the delay time for starting the increase in fuel to the center port as the degree of acceleration increases.