JP4467820B2 - Operation control device for fuel injection type 4-cycle engine - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an operation control device suitable for, for example, a so-called water motorcycle engine or outboard motor engine.
[0002]
[Prior art]
Conventionally, as an operation control device suitable for a water motorcycle engine or an outboard motor engine, the intake negative pressure and the engine rotation speed (rpm) are reduced in the operation range on the side where the throttle valve opening is small (low speed rotation / low load side). The fuel injection amount is determined on the basis of the throttle valve opening and the engine injection speed is determined based on the throttle valve opening and the engine rotational speed in the operating range where the throttle valve opening is large (high speed rotation / high load side). is there.
[0003]
[Problems to be solved by the invention]
By the way, in the conventional engine operation control device, the air (oxygen) density decreases when the atmospheric pressure becomes low. In general, the air density decreases from the atmospheric pressure, and the injection amount is reduced to reduce the air-fuel ratio. Control is performed to maintain the proper level.
[0004]
However, in the case of an independent throttle intake fuel injection engine, the injection amount on the low throttle valve opening side is determined from the intake negative pressure and the engine rotation speed, and the injection amount on the high throttle valve opening side is the throttle valve opening and engine rotation speed. Is determined from. Since the intake negative pressure is affected by the atmospheric pressure, the correction of only the air density is not sufficient, and there is a concern that the air-fuel ratio becomes rich.
[0005]
The present invention has been made in view of the above-mentioned problems, and provides an engine operation control device that can perform atmospheric pressure correction suitable for each fuel injection amount determination method and appropriately control the air-fuel ratio. Is an issue.
[0006]
[Means for Solving the Problems]
In the first aspect of the present invention, the first fuel injection amount is obtained based on the intake negative pressure and the engine speed in the first operating range where the throttle valve opening is equal to or less than the first predetermined opening . In a fuel injection type four-cycle engine operation control device in which a second fuel injection amount is obtained based on a throttle valve opening and an engine rotational speed in a second operating region that is greater than a second predetermined opening and greater than a predetermined opening .
In the first operating region, the first fuel by the first correction value set to a small correction value as the atmospheric pressure is smaller (%) The impact of the intake negative pressure due and atmospheric pressure to the air density by atmospheric pressure Correct the injection amount,
In the second operating region, the second fuel injection amount is corrected by the second correction value set to a smaller correction value (%) as the atmospheric pressure is smaller as an influence of the atmospheric pressure on the air density,
In the region where the atmospheric pressure is smaller than the predetermined value, the first correction value is set to a value smaller than the second correction value, and the first correction value is smaller than the second correction value decreases the second fuel injection amount. Is characterized by greatly reducing the first fuel injection amount .
[0007]
According to a second aspect of the present invention, in the first aspect, the ISC valve is disposed in a bypass passage that bypasses the throttle valve, and the degree of opening of the ISC valve increases as the throttle opening increases in the first operating range. The ISC valve control means is provided which is enlarged and is fixed to be fully open at least in a portion near the first operation region of the second operation region .
[0008]
According to a third aspect of the present invention, the first fuel injection amount is obtained based on the intake negative pressure and the engine speed in the first operating range where the throttle valve opening is equal to or less than the first predetermined opening, and the throttle valve opening is set to the first predetermined opening. In a fuel injection type four-cycle engine operation control device in which a second fuel injection amount is obtained based on a throttle valve opening and an engine speed in a second operating region that is greater than a second predetermined opening that is greater than the opening.
In the first operating region, the first fuel injection amount is corrected by first correcting means for correcting the influence of the atmospheric pressure on the air density and correcting the influence of the atmospheric pressure on the intake negative pressure. In the region, the second fuel injection amount is corrected by the second correction means for correcting the influence of the atmospheric pressure on the air density,
An ISC valve is disposed in a bypass passage that bypasses the throttle valve, and the opening of the ISC valve is increased as the throttle opening is increased in the first operating range, and at least the second operating range of the second operating range is set. An ISC valve control means that is fixed fully open is provided near the one operating range.
[0009]
[Effects of the invention]
According to the first aspect of the present invention, the first fuel injection amount is corrected by the first correcting means in the first operating region, and the second fuel injection amount is corrected by the second correcting device in the second operating region. The correction according to the determination method of the first and second fuel injection amounts is possible. That is, the first fuel injection amount determined based on the intake negative pressure can be corrected by taking into account not only the influence of the atmospheric pressure on the air density but also the influence of the atmospheric pressure on the intake negative pressure. It becomes possible to control with higher accuracy.
[0010]
Further , the first and second fuel injection amounts are corrected with the first correction value and the second correction value set to smaller correction values (%) as the atmospheric pressure is smaller, and the second correction value is the second fuel injection. Since the first correction value is made to decrease the first fuel injection amount more greatly than to reduce the amount, the fuel injection more effectively conforms to the first fuel injection amount set by the intake negative pressure and the engine speed. The amount can be corrected.
[0011]
According to the invention of claim 3, since the opening of the ISC valve provided in the bypass passage that bypasses the throttle valve is increased as the throttle valve opening increases in the first operating region, in the first operating region, There is a concern that the air-fuel ratio changes due to a change in the opening of the ISC valve. In the present invention, since the opening of the ISC valve is changed in the first operating range in which the fuel injection amount is obtained from the intake negative pressure, the increase in air due to the change in the opening of the ISC valve can be detected by the change in the intake negative pressure. As a result, the influence of the ISC valve on the air-fuel ratio can be reduced. In addition, since the first and second fuel injection amounts are corrected by the first and second correction means separately in the first operation area and the second operation area, the first correction means (first correction value) is changed. It is possible to set a correction value corresponding to the change in the air-fuel ratio due to the change in the opening of the ISC valve.
[0012]
Further, the fuel injection amount is obtained from the throttle valve opening in the second operating range, and the increase in the air amount due to the change in the opening of the ISC valve cannot be detected. Since the opening of the ISC valve is fixed near the operating range, the deviation of the air-fuel ratio from the desired value due to the change in the opening of the ISC valve can be prevented as much as possible.
[0013]
Embodiment
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0014]
1 to 6 are views for explaining an operation control device for a water motorcycle engine according to an embodiment of the present invention, FIG. 1 is a side view of a water motorcycle equipped with the engine of the present embodiment, and FIG. 3 is a block diagram of an engine operation control system, FIG. 3 is a two-dimensional map showing the relationship between the throttle valve opening, the operating region, and the ISC valve opening, FIGS. 4 and 5 are fuel injection amount setting three-dimensional maps, FIG. Is a fuel injection amount correction two-dimensional map.
[0015]
In the figure, reference numeral 1 denotes a water motorcycle, which includes a hull 2, an engine 3 housed and mounted in the hull 2, a propulsion unit 4 disposed at the rear of the hull 2 and driven by the engine 3. It has.
[0016]
The hull 2 has a box-like shape in which a lid-plate-like deck 6 is mounted on a so-called bathtub-shaped hull 5 and both are sealed together by a gunnel 7. A hatch 8 is mounted on the deck 6 above the engine 3 so as to be openable and closable forward with a front end hinge 8a as a fulcrum, and a storage case opening / closing lid 9 is mounted on the hatch 8 so as to be openable and closable forward. . Further, a steering handle 10 is disposed at the rear part of the hatch 8, and the steering handle 10 swings the jet port 11 of the propulsion unit 4 to the left and right to control the surface traveling boat 1 to the left and right. It comes to be suitable. A saddle-type seat 12 is mounted behind the steering handle 10 of the hull 2.
[0017]
The propulsion unit 4 is provided with a suction duct 13 at the rear part of the hull 2, an impeller 14 is provided in the middle of the duct 13, and a jet port 11 is provided at the rear end part so as to be able to swing left and right. 14 is driven by a propeller shaft 15. The suction port 13 a of the suction duct 13 is open to the bottom surface of the hull 2.
[0018]
The engine 3 is a fuel injection type 4-cycle 4-cylinder engine. The engine 3 connects a piston 3a slidably inserted into a cylinder bore to a crankshaft 3c by a connecting rod 3b, and opens and closes an intake valve 3f and an exhaust valve 3g at the combustion chamber side openings of the intake passage 3d and the exhaust passage 3e. The intake valve 3f and the exhaust valve 3g are configured to be opened and closed by the intake cam shaft 3h and the exhaust cam shaft 3i. 3j is a spark plug, and the output shaft of the engine 3 is connected to the propeller shaft 15.
[0019]
A fuel injection valve 16 is disposed in the intake passage 3d, and fuel in the fuel tank 17 is supplied to the fuel injection valve 16 by a fuel pump 18. A throttle valve 19 is disposed upstream of the fuel injection valve 16 in the intake passage 3d.
[0020]
A bypass passage 25 for bypassing the throttle valve 19 is provided. The upstream end of the bypass passage 25 is connected to an intake silencer connected to the upstream end of the intake passage 3d, and the downstream end is connected to the downstream side of the throttle valve 19 in the intake passage 3d. An ISC valve 25 a is interposed in the bypass passage 25. The opening degree of the ISC valve 25a is controlled by a step motor 25b based on a control signal d from the control unit 20.
[0021]
The control unit 20 performs operation control of the engine 3 such as ignition timing control, fuel injection timing, and injection amount control. The control unit 20 detects from various sensors such as an engine speed sensor 21, a throttle opening sensor 22, an engine temperature sensor 23, an intake pressure sensor 24, an exhaust gas O ₂ sensor 26, a hydraulic pressure sensor 27, and a fuel level sensor 28. A signal is input to obtain an optimum operating condition, a fuel injection control signal a for the fuel injection system, an ignition timing control signal b for the ignition system, a fuel pump control signal c for the fuel pump 18, and an ISC valve for the ISC valve 19b. A valve control signal d is output.
[0022]
In the storage unit of the control unit 20, an upper limit value (about 6 degrees in the present embodiment) of the throttle opening for operating the ISC valve 25a is set and stored as an ISC valve operation set value. Further, a throttle opening-ISC valve opening two-dimensional map shown in FIG. 3B is stored.
[0023]
Further, the storage unit of the control unit 20 stores intake negative pressure and engine speed in the first operating region (DJ region, specifically, the region where the throttle valve opening is 6 degrees or less) on the side where the throttle valve opening is small. The first fuel injection amount three-dimensional map (see FIG. 4) for obtaining the first fuel injection amount based on the speed, and the second operating region (α-N region, specifically, the throttle valve opening larger side) A second fuel injection amount three-dimensional map (see FIG. 5) for determining the second fuel injection amount based on the throttle valve opening and the engine speed in the throttle valve opening 9 ° region or more) is stored. . In the present embodiment, the boundary between the DJ area and the α-N area is a transition area (see FIG. 3A).
[0024]
In the DJ region, DJ control using the first fuel injection amount three-dimensional map is performed, and the intake negative pressure (Qm) detected by the intake pressure sensor 24 and the engine rotational speed sensor in the map shown in FIG. The fuel injection amount (Bmn) is obtained based on the engine speed (Cn) detected by the engine 21.
[0025]
In the α-N region, α-N control is performed using the second fuel injection amount map, and the throttle opening (Km) detected by the throttle opening sensor 22 in the map shown in FIG. 5 and the engine speed. A fuel injection amount (Amn) is obtained based on (Cn).
[0026]
In the transition region, the DJ control and the α-N control are mixed. For example, when the throttle valve opening is 7.5 degrees, 50% of the first fuel injection amount obtained from the map of FIG. 4 and 50% of the second fuel injection amount obtained from the map of FIG. Is required.
[0027]
The control unit 20 further determines the first fuel injection amount determined based on the first fuel injection amount map in the first operating region and the second fuel injection amount map in the second operating region. A two-dimensional map (see FIG. 6) for correcting the second fuel injection amount and the fuel injection amount obtained in the transition region based on the atmospheric pressure is stored.
[0028]
In FIG. 6, the DJ correction value curve is a first correction means for correcting the first fuel injection amount (Bmn) based on the influence on the air density by the atmospheric pressure and the influence on the intake negative pressure by the atmospheric pressure. Function. The α-N correction value curve functions as second correction means for correcting the second fuel injection amount based on the influence of the atmospheric pressure on the air density. In the transition region, a correction value obtained by mixing the DJ correction value and the α-N correction value is used.
[0029]
Here, in FIG. 6, when the DJ correction value curve and the α-N correction value curve are compared, the DJ control, that is, the correction value (%) when the throttle valve opening is 6 degrees or less is α-N. It is set smaller than the control value, that is, the correction value (%) when the throttle valve opening is 9 degrees or more. This means that the DJ correction value reduces the first fuel injection amount more greatly in the DJ control than the α-N correction value reduces the second fuel injection amount in the α-N control. In other words, this indicates that the influence of the atmospheric pressure on the determination of the fuel injection amount in the DJ control is larger than the influence in the α-N control.
[0030]
That is, in the DJ control, the fuel injection amount is determined by the intake negative pressure. Therefore, when the atmospheric pressure decreases (increases toward the negative pressure side), the intake negative pressure also increases. The fuel ratio becomes rich. Therefore, in this embodiment, this problem is prevented by further reducing the first fuel injection amount by reducing the correction value.
[0031]
Next, the effect of this embodiment is demonstrated.
The opening degree control of the ISC valve 25a is performed as follows. The control unit 20 reads the current throttle valve opening and the ISC valve opening, determines the target ISC valve opening corresponding to the detected throttle valve opening based on the two-dimensional map of FIG. An ISC valve control signal d set so as to reduce the difference between this and the detected ISC valve opening is output to the step motor 25b.
[0032]
In this way, in the DJ region where the throttle valve opening is 6 degrees or less, which is the set value for operating the ISC valve, the ISC valve opening increases as the throttle valve opening increases, and when the throttle valve opening is 6 degrees. The throttle valve is fully open, and is fixed fully open in the α-N region where the throttle valve opening is larger.
[0033]
The fuel injection amount is determined by the following procedure. When the throttle valve opening is in the DJ region of 6 degrees or less, the control unit 20 determines the first fuel injection amount based on the DJ control three-dimensional map of FIG. A first corrected fuel amount that takes into account the influence of the atmospheric pressure on the air density and intake negative pressure is obtained by integrating the fuel injection amount and the DJ correction value (%) obtained from the DJ correction value curve of FIG. The control signal a corresponding to the first corrected fuel amount is output to the fuel injection valve 16, and the first corrected fuel is injected from the fuel injection valve 16.
[0034]
Further, when the throttle valve opening is in the α-N region of 9 degrees or more, the second fuel injection amount is obtained based on the three-dimensional map for α-N control in FIG. 5, and the obtained second fuel injection amount and A second corrected fuel amount that takes into account the influence of the atmospheric pressure on the air density is obtained by integration with the α-N correction value (%) obtained from the α-N correction value curve of FIG. A corresponding control signal a is output to the fuel injection valve 16, and the second corrected fuel is injected from the fuel injection valve 16.
[0035]
Furthermore, when the throttle valve opening is in the transition region of 6 to 9 degrees, the first correction fuel amount obtained from the DJ control map and corrected by the DJ correction value, and α-N The second corrected fuel amount obtained from the control map and further corrected by the α-N correction value is mixed at a rate corresponding to the throttle valve opening, and the amount of fuel determined thereby is obtained from the fuel injection valve 16. Be injected.
[0036]
As described above, in the present embodiment, the DJ correction value in the DJ control and the α-N correction value in the α-N control are provided separately, so that the correction value according to the method for determining the fuel injection amount is set. This makes it possible to achieve an appropriate air-fuel ratio with higher accuracy. That is, in the DJ control, the fuel injection amount is set based on the intake negative pressure and the engine speed, while in the α-N control, the fuel injection amount is set based on the throttle opening and the engine speed. . In the DJ control, the atmospheric pressure affects not only the air density but also the intake negative pressure. Therefore, the air flow rate is detected more than the actual amount, and an amount of fuel corresponding to this is injected. It becomes rich. In the present embodiment, since the correction value is made separate as described above, the DJ correction value is set to a value smaller than the α-N correction, and the fuel is decreased more in the first operation region than in the second operation region. Therefore, it is possible to prevent the fuel amount from becoming excessive and the air-fuel ratio from becoming rich.
[0037]
In the present embodiment, since DJ control and α-N control are mixed in the transition region between the DJ region and the α-N region, switching from DJ control to α-N control is possible. It is performed smoothly and the problem that the driving feeling deteriorates at the time of switching can be avoided.
[0038]
Further, since the opening of the ISC valve 25a is increased as the throttle valve opening increases in the first operating range in which the fuel injection amount is obtained from the intake negative pressure, the air increase due to the change in the opening of the ISC valve 25a is taken into account. As a result, the influence of the ISC valve 25a on the air-fuel ratio can be mitigated. In addition, since the first and second fuel injection amounts are corrected by the first and second correction values which are different in the first operation region and the second operation region, the first correction value is used as the opening degree of the ISC valve 25a. It is possible to set a correction value corresponding to the change of the air-fuel ratio due to the change. From this point, the air-fuel ratio can be controlled to a desired value.
[0039]
Further, the fuel injection amount is obtained from the throttle valve opening in the second operation region, and the increase in the air amount due to the change in the opening of the ISC valve cannot be detected, but the first operation which is greatly influenced by the ISC valve in the second operation region. Since the opening of the ISC valve 25a is fixed in the region and the transition region, a deviation from the desired value of the air-fuel ratio due to a change in the opening of the ISC valve can be prevented as much as possible.
[Brief description of the drawings]
FIG. 1 is a side view of a water motorcycle equipped with an engine according to an embodiment of the present invention.
FIG. 2 is a block diagram of an operation control apparatus for an engine according to the embodiment.
FIG. 3 is a two-dimensional map showing the relationship between the throttle valve opening, the operating region, and the ISC valve opening stored in the control unit of the operation control apparatus.
FIG. 4 is a fuel injection amount three-dimensional map stored in a control unit of the operation control apparatus.
FIG. 5 is a fuel injection amount setting three-dimensional map stored in a control unit of the operation control apparatus.
FIG. 6 is a two-dimensional map for fuel injection amount correction stored in a control unit of the operation control apparatus.
[Explanation of symbols]
3 Fuel injection type 4-cycle engine 19 Throttle valve 20 Control unit (operation control device)
25 Bypass passage 25a ISC valve DJ 1st operation area α-N 2nd operation area

Claims (3)

In the first operating range where the throttle valve opening is equal to or less than the first predetermined opening , the first fuel injection amount is obtained based on the intake negative pressure and the engine speed, and the throttle valve opening is larger than the first predetermined opening. In a fuel injection type four-cycle engine operation control device in which the second fuel injection amount is obtained based on the throttle valve opening and the engine rotational speed in the second operating region above a predetermined opening .
In the first operating region, the first fuel by the first correction value set to a small correction value as the atmospheric pressure is smaller (%) The impact of the intake negative pressure due and atmospheric pressure to the air density by atmospheric pressure Correct the injection amount,
In the second operating region, the second fuel injection amount is corrected by the second correction value set to a smaller correction value (%) as the atmospheric pressure is smaller as an influence of the atmospheric pressure on the air density,
In the region where the atmospheric pressure is smaller than the predetermined value, the first correction value is set to a value smaller than the second correction value, and the first correction value is smaller than the second correction value decreases the second fuel injection amount. An operation control device for a fuel injection type 4-cycle engine, wherein the first fuel injection amount is greatly reduced . The ISC valve is disposed in a bypass passage that bypasses the throttle valve according to claim 1, and the opening of the ISC valve is increased as the throttle opening increases in the first operating range, and the second operation is performed. An operation control device for a fuel injection type four-cycle engine, characterized in that an ISC valve control means for fixing the valve to a fully open position is provided at least near the first operation region . In the first operating range where the throttle valve opening is equal to or less than the first predetermined opening, the first fuel injection amount is obtained based on the intake negative pressure and the engine speed, and the throttle valve opening is larger than the first predetermined opening. In a fuel injection type four-cycle engine operation control device in which the second fuel injection amount is obtained based on the throttle valve opening and the engine rotational speed in the second operating region above a predetermined opening.
In the first operating region, the first fuel injection amount is corrected by first correcting means for correcting the influence of the atmospheric pressure on the air density and correcting the influence of the atmospheric pressure on the intake negative pressure. In the region, the second fuel injection amount is corrected by the second correction means for correcting the influence of the atmospheric pressure on the air density,
An ISC valve is disposed in a bypass passage that bypasses the throttle valve, and the opening of the ISC valve is increased as the throttle opening is increased in the first operating range, and at least the second operating range of the second operating range is set. An operation control device for a fuel injection type four-cycle engine, characterized in that an ISC valve control means is provided that is fixed fully open at a portion close to one operation region.

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