JP3361533B2 - Electronic control unit for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotational speed of an internal combustion engine,
The present invention relates to an electronic control unit for an internal combustion engine that controls a fuel supply amount, an ignition timing, and the like based on intake air pressure and a throttle valve opening degree of a throttle or the like as parameters and control data obtained based on the parameters. 2. Description of the Related Art For example, as disclosed in Japanese Patent Application Laid-Open No. 56-96132, an opening degree of a throttle valve (throttle valve) for controlling an intake air amount to an engine is used as a control device for an engine of a motorcycle or the like. Data corresponding to the operating condition of the engine is selected from among engine operating parameters such as θth, intake pressure Pm to the engine, and engine speed Ne, and electronic control such as fuel injection amount and ignition timing. It is known to perform In this case, the rotation speed data Ne and the intake pressure Pm are selected when the engine is in a low load state, and the rotation speed data Ne and the throttle valve opening data θth are selected in a medium and high load state. An engine control amount (fuel injection amount, ignition timing, etc.) stored and set in a map form is output. As means for improving the torque and horsepower of the engine, it has been considered to open the intake duct in the direction of travel of the vehicle and to take in the vehicle speed while the vehicle is running. That is, the intake efficiency is improved by the dynamic pressure P corresponding to the vehicle speed V. [0005] However, when the intake efficiency is improved by such a dynamic pressure P, a problem arises particularly when performing control for deriving an engine control amount based on the rotation speed data Ne and the throttle valve opening data θth. That is, as the vehicle speed V increases, the vehicle speed wind increases, the amount of intake air using the vehicle speed wind increases, the intake efficiency is improved, and a larger output can be obtained. As described above, even when the throttle valve opening θth has the same value, the vehicle speed V increases to increase the vehicle speed wind and change the amount of air taken into the engine. Regardless of the change, in the conventional method (α-N method) of determining the control amount of the engine based on the information of the rotation speed Ne and the throttle valve opening θth, it is always possible to set only a constant engine control amount. Can not. Therefore, not only cannot proper engine control be performed, but also the effect that the effect cannot be sufficiently obtained despite setting the intake duct in the traveling direction of the vehicle for the purpose of improving the intake efficiency. there were. SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and detects a dynamic pressure P which fluctuates due to a change in an intake air amount in accordance with a change in a vehicle speed V. By setting the control amount of the internal combustion engine based on the dynamic pressure P in addition to the information on the rotational speed Ne and the throttle valve opening θth, the internal combustion engine capable of always executing appropriate internal combustion engine control. An object is to provide an electronic control device. An electronic control unit for an internal combustion engine according to the present invention determines a first control amount of the internal combustion engine based on the rotation speed Ne of the internal combustion engine and the throttle valve opening θth. Do
The first control amount setting means, the rotation speed Ne of the internal combustion engine and the suction speed
Second control of the internal combustion engine based on the intake pressure Pm of the air passage
Second control amount setting means for determining the amount;
At least one of these two control variables
A third control amount that is set based on one of the control amounts;
Control amount setting means. Then, the control means
The internal combustion engine is controlled based on the third control amount. This
In such an electronic control unit for an internal combustion engine, a control amount determined based on the rotational speed Ne detected by the rotational speed detecting means and the throttle valve opening θth detected by the throttle valve opening detecting means is determined by a dynamic pressure detecting means. The first control amount of the internal combustion engine is determined by correction based on the dynamic pressure P detected in step ( 1 ). The electronic control unit for an internal combustion engine configured as described above has, for example, an intake duct opened in the traveling direction of the vehicle, and receives a dynamic pressure P corresponding to the vehicle speed. Basically, the control amount of the internal combustion engine can be obtained from the internal combustion engine rotation speed Ne and the throttle valve opening degree θth. In particular, when the vehicle is running, the dynamic pressure P corresponding to the vehicle speed is increased. It is detected, and the control amount is corrected based on the dynamic pressure P. Therefore, in the control device that takes in the dynamic pressure P, appropriate internal combustion engine control is always executed. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a basic configuration of a control circuit section constituted by a microcomputer and the like for performing electronic control of the internal combustion engine 11. The intake pressure taking in a detection signal from an intake pressure sensor set for the internal combustion engine 11 is shown. Pm detection means
12, cranking detection means 13 for detecting a signal from a rotation angle sensor of the engine 11, a rotation speed Ne detection means 14 for capturing a detection signal from a rotation sensor set on the rotation axis of the engine 11,
And a throttle (throttle valve) opening θth detecting means 15 for taking in a detection signal from a throttle opening sensor. In this control circuit, a reference dynamic pressure search means 16 constituted by a storage device storing the reference dynamic pressure Pmo when the vehicle speed is zero is set. Here, the cranking angle detecting means 13 determines whether or not cranking is being performed by the starter signal, and the intake pressure during this cranking is detected as atmospheric pressure by the atmospheric pressure detecting means 17,
Further, the output from the atmospheric pressure correcting means 18 for correcting the intake pressure at the time of the dynamic pressure “0” is supplied to the reference dynamic pressure searching means 16 based on the atmospheric pressure. In the reference dynamic pressure searching means 16, for example, when the throttle valve opening θth is 10 °, 20 °,
..., 80 ° each, and the rotation speed Ne is 1000 rpm, 2
The reference dynamic pressure Pmo is stored as a map in relation to each of 000 rpm,. The reference dynamic pressure search circuit 16 is supplied with detection data of the intake pressure Pm from the intake pressure detecting means 12 and the rotational speed Ne from the rotational speed detecting means 14, and receives the reference dynamic pressure based on the rotational speed Ne. Search for pressure Pmo. Then, based on the difference between the retrieved reference dynamic pressure Pmo and the intake pressure Pm at that time, the dynamic pressure detecting means 19 detects the dynamic pressure P. The signal Pm from the intake pressure detecting means 12 and the detection signal Ne from the rotational speed detecting means 14 are calculated by the first calculating means 2
Supply 0. Then, the first engine control amount is calculated by the first calculating means 20. Also, the rotation speed detecting means 14
, A detection signal θth from the throttle opening detection means 15, and a detection signal P from the dynamic pressure detection means 19.
Is supplied to the second calculating means 21. Then, the second calculation means 21 calculates a second engine control amount. The control amounts calculated by the first and second calculation means 20 and 21 are selected by the selection means 22 according to the control situation of the engine 11, and the selected control amount is determined by the engine (internal combustion engine). It is supplied to the control means 23 and is used for controlling the amount of fuel supplied to the internal combustion engine 11, the ignition timing, and the like. Here, the selection means 22 selects one of the first engine control amount from the first calculation means 20 and the second engine control amount from the second calculation means 21. However, for example, a gradual change unit that gradually changes the first engine control amount to the second engine control amount may be included. FIG. 2 shows the configuration of an engine (internal combustion engine) 31 in which fuel injection control, ignition timing control, and the like are performed electronically and peripheral devices. In the intake pipe 32 of the engine 31,
Air containing dynamic pressure is introduced, and the intake air is guided to the cylinder of the engine 31 via the air cleaner 33. And
The intake pipe 32 is provided with a throttle valve (throttle valve) 34 operated by an accelerator pedal (not shown) to control the amount of intake air. The engine 31 is provided with a rotation angle sensor 35 for detecting the state of rotation of the engine 31 so that a cylinder discrimination signal and an angle signal of the engine 31 are detected. Based on the angle signal, an engine speed signal Ne is obtained. Is required. An intake pipe pressure sensor 36 is provided so as to communicate with the intake pipe 32, and an opening degree sensor 37 is provided for the throttle valve 34.
And the throttle valve angle θth are obtained. The intake pipe 32 is provided with an intake air temperature sensor 38 for detecting the temperature of the intake air and a water temperature sensor 39 for detecting the temperature of the cooling water of the engine 31. Then, the detection signals of the intake air temperature and the water temperature, and the above sensors 35 and 3
The detection signals from the respective devices 6 and 37 are supplied to a control device 40 comprising an electronic control unit constituted by a microcomputer, for example, to calculate an appropriate fuel injection amount and an ignition timing, and to calculate an intake pipe based on these calculation results. A fuel injection command is given to an injector 41 provided in a portion 32, and an ignition command is given to a spark plug. At the time of calculating the fuel injection amount and the ignition timing, an atmospheric pressure correction that recognizes the intake pressure taken when the starter signal (not shown) is turned on as the atmospheric pressure, a water temperature sensor 39, an intake temperature sensor 38, and the like. The correction is performed based on the detection signal from the sensor, and a command is given from the control device 40 to the injector 41 and the ignition plug. FIG. 3 illustrates an air intake portion of the intake pipe 32. The intake pipe 32 has an intake duct 321 that opens in front of the vehicle body, and a dynamic pressure P corresponding to the traveling speed of the vehicle is taken in. It has become. Then, the intake air taken in through the intake duct 321 is guided to the throttle valve portion via the air cleaner 33, and the intake air passing through the throttle valve portion is introduced into the engine 31. By improving the intake efficiency by the dynamic pressure P in this manner, effective combustion can be obtained in the engine 31. In the electronic control device shown in the embodiment,
The DJ system for calculating the basic fuel injection amount based on the intake pressure Pm of the engine 31 and the rotation speed Ne of the engine 31, and the basic fuel injection based on the opening degree θth of the throttle valve 34 of the engine 31 and the rotation speed Ne of the engine 31. The α-N method for calculating the quantity is used together. FIG. 4A shows an idle rotation state (low load operation) in a state where the rotation speed Ne of the engine 31 is kept constant.
5 shows an example of a change state of the intake pressure Pm and the throttle opening θth in which the load is gradually increased from the state of FIG. As is apparent from this figure, when the load changes from "0" to full load, the intake pressure Pm decreases exponentially and the throttle opening .theta.th increases almost exponentially. In consideration of such considerations, in this embodiment, the intake pressure Pm is mainly used as a parameter when the engine 31 is in a low load state, and the throttle opening θth is mainly used as a parameter in a medium or high load state. .
In this manner, the operation control of the engine 31 is performed using the parameter having a large rate of change with respect to the load variation over the entire operation range from the “0” load state to the full load state. The selection of the parameters of the intake pressure Pm and the throttle opening θth is performed by selecting a preset value of the detection value of the opening θth, for example, both the intake pressure Pm and the throttle opening θth shown in FIG. The comparison is made with the values θth1 and θth2 near the intersection F of the curve. For example, when the detected value of the throttle opening θth is smaller than the set value θh1, the control amount is determined mainly according to the detected value of the intake pressure Pm, and the fuel injection amount is controlled. When the throttle opening θth increases and exceeds the throttle opening θth2, a control amount mainly corresponding to the detected value θth of the throttle opening is determined, and the fuel injection amount control corresponding to the control amount is determined. Is executed. Further, when the value of the throttle opening θth is between the set values θth1 and θth2, the detected value Pm of the intake pressure and the throttle opening θth are used as shown in FIG. 4B. The value determined by performing the weighting is adopted as the control amount, and the engine 31 is controlled. As shown in FIG. 3, the intake duct of the intake pipe 32
When the 321 is set to open in the direction of travel of the vehicle,
The absolute pressure Pm of the intake pipe 32 changes as shown in FIG. 4C depending on the dynamic pressure P during running of the vehicle. That is, as shown by the solid line, the absolute intake pressure when the vehicle speed wind is "0"
In contrast to Pm0, the absolute intake pressure Pm when there is a vehicle speed wind is indicated by a broken line.
As the vehicle speed increases, it becomes relatively large. When the intake duct 321 is opened in the vehicle traveling direction and the control is performed using both the DJ method and the α-N method, the control is performed in the α-N method. The control amount shifts by the increase of the intake pressure due to the dynamic pressure P. Therefore, in the control device shown in this embodiment, the dynamic pressure P is corrected at the time of controlling the α-N method. FIG. 5 shows a control device 30 for calculating the fuel injection amount.
2 shows the flow of the process. First, in step 101, the opening information θth obtained by converting the detection signal from the throttle valve opening sensor 37 into a digital signal is read. In step 102, the read throttle valve opening θth is compared with a set value θth2. If it is determined that the detected opening degree θth exceeds the set opening degree θth2, step 103
To set the weight constant K of the DJ method and the α-N method to “1”.
And control is performed only by the α-N method.
If it is determined in step 102 that the detected value θth is smaller than the set value θth2, the routine proceeds to step 104, where DJ is performed.
K is searched for the weight constant of the method and the α-N method, or control is performed only by the DJ method. In step 105, the intake pressure Pm obtained by converting the detection output signal from the pressure sensor 36 into a digital signal is read. Further, in step 106, the rotation angle
For example, the rotational speed Ne of the engine 31 obtained based on a pulse signal generated at every 180 ° CA is read. In the next step 107, the intake pressure Pm0 corresponding to the rotational speed Ne in the state where the vehicle speed wind stored in advance is "0" and the dynamic pressure P is "0" is determined by the rotational speed Ne at that time and the throttle opening. The storage device is searched based on the degree θth and read. The intake pipe pressure Pm0 when the vehicle wind speed is "0" is
As described above, one of the components of the control device 40 is mapped.
Stored in the storage device. In step 108, the intake pipe pressure Pmo taken in step 107 is corrected based on the following formula using the intake pressure taken in during cranking, that is, the atmospheric pressure. Pmo ← Pmo × (acquired atmospheric pressure / 760) In step 109, the intake pipe pressure Pm0 at the time of the vehicle speed wind “0” obtained in step 108, and the current vehicle speed
Intake pipe pressure P with dynamic pressure P applied when wind is present
m, the pressure increase DPm due to the dynamic pressure P is expressed as “DP
m = Pm-Pm0 ". Then, at step 110, the fuel injection increase FRA is obtained based on the pressure increase DPm due to the dynamic pressure P. At step 111, α-N, that is, the throttle is opened. Based on the degree θth and the engine speed Ne, the fuel injection time width Tθth · N is searched from a map of the throttle opening degree θth and the speed Ne that are adapted in advance.
At 112, the fuel injection width TP · N is retrieved from a map of the intake pipe pressure Pm and the rotational speed Ne that is previously adjusted, based on DJ, that is, the intake pipe pressure Pm and the rotational speed Ne. In step 113, the basic fuel injection width TB is
It is obtained from the weighting of α-N and DJ. For α-N, weighting K, intake pipe pressure θth and rotational speed N adapted in advance
e, the fuel injection width Tθth · N retrieved from the map and the fuel injection increment F obtained from the pressure rise DPm due to the dynamic pressure P.
Obtain from RA. For DJ, the weighting K
From the fuel injection width TP · N retrieved from the map of the intake pipe pressure Pm and the rotational speed Ne that are previously adapted. In step 114, the final injector drive is determined based on the basic fuel injection width TB determined in step 113, the acceleration / deceleration state, correction values β such as the water temperature and intake air temperature, and the injector operating time γ determined from the battery voltage. Find the time width TAU. Then, in the next step 115
The final drive time TAU obtained in 114 is output to the injector 41, and fuel is injected within the time width. In the above-described embodiment, the fuel injection control has been described.
It is also possible to use the α-N method and the DJ method together and correct the region of the α-N method by the pressure increase DPm due to the dynamic pressure P. Further, in the embodiment, the control amount is set by switching between the DJ system and the α-N system in accordance with the load state of the engine.
Alternatively, the control amount may be set in consideration of the dynamic pressure P. Further, in the embodiment, the dynamic pressure P is detected based on the detection result of the intake pressure sensor 36, and the control amount is set in consideration of the dynamic pressure P. For example, the rotational speed N when the vehicle speed wind is zero is used.
The dynamic pressure P may be obtained from the intake air amount per unit time corresponding to e and the throttle valve opening degree θth, and the actual intake air amount per unit time when the vehicle is running. And the dynamic pressure P may be obtained based on information from the vehicle speed sensor. As described above, in the electronic control unit for an internal combustion engine according to the present invention, the DJ system and the α-N system are used in combination, and the state of “0” load is changed to the state of full load. The fuel injection control of the internal combustion engine is performed using the parameter having a large rate of change with respect to the load variation over the entire operation range up to. In such control, the engine control using the dynamic pressure P obtained as the vehicle travels is always executed accurately, and the intake efficiency is improved using the dynamic pressure P corresponding to the vehicle speed. In this case, accurate engine control in consideration of the dynamic pressure is performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram schematically illustrating an electronic control unit for an internal combustion engine according to an embodiment of the present invention. FIG. 2 is a diagram showing a specific configuration example of an apparatus according to the embodiment. FIG. 3 is a diagram showing the intake pipe portion shown in FIG. 2 taken out. FIG. 4A is an intake pipe pressure Pm corresponding to an engine load.
FIG. 4B is a diagram showing a change in throttle valve opening θth, FIG. 4B is a diagram showing the state of a weighting constant K corresponding to the throttle valve opening θth, and FIG. 4C is a diagram showing the relationship between the intake pipe absolute pressure and the vehicle speed. FIG. 5 is a flowchart for explaining the flow of the operation of the embodiment. [Description of Signs] 11, 31: engine, 12: intake pressure detecting means, 13: cranking detecting means, 14: rotational speed detecting means, 15: throttle opening detecting means, 16: reference dynamic pressure detecting means, 17 ... Atmospheric pressure detecting means, 18 ... Atmospheric pressure correcting means, 19 ... Dynamic pressure P detecting means, 20,
21: first and second calculation means, 22: selection means, 23: engine control means, 32: intake pipe, 321: intake pipe duct, 34
... throttle valve, 35 ... rotation angle sensor, 36 ... intake pipe pressure sensor, 37 ... opening degree sensor, 40 control device, 41 ... injector, 42 ... spark plug.

Continuation of front page       (56) References JP-A-1-315635 (JP, A)                 JP-A-61-4837 (JP, A)                 JP-A-61-101632 (JP, A)                 JP-A-64-66449 (JP, A)                 JP-A-56-96132 (JP, A)                 62-110533 (JP, U)                 Actual opening 58-102380 (JP, U)

Claims (1)

(57) [Claim 1] A rotation speed detecting means for detecting a rotation speed Ne of an internal combustion engine, and an opening degree θ of a throttle valve for controlling an intake air amount to the internal combustion engine.
throttle opening detection means for detecting th, and intake pressure detection for detecting intake pressure Pm downstream of the throttle valve
Means for determining a first control amount of the internal combustion engine based on the rotation speed Ne detected by the rotation speed detection means and the throttle valve opening θth detected by the throttle valve opening detection means . Control amount setting
Determining means, the rotational speed Ne detected by the rotational speed detecting means and the intake air.
Internal combustion based on the intake pressure Pm detected by the pressure detecting means.
Second control amount setting means for determining a second control amount of the engine
And the first control amount and the second control based on an operation state.
A third control amount based on at least one of the
And a control means for controlling the internal combustion engine based on the third control amount.
Stage and provided with an open intake duct so that the dynamic pressure P is captured by the vehicle speed wind, the intake pressure detecting dynamic pressure P by the vehicle speed wind
And a dynamic pressure detection means for detecting, based on the intake pressure Pm detected by unit, the first control amount setting means, the rotational speed detected rotation speed Ne and the throttle valve opening degree detected by the detection means The control amount determined based on the throttle valve opening θth detected by the means is corrected by the dynamic pressure P detected by the dynamic pressure detection means to determine the first control amount of the internal combustion engine . An electronic control unit for an internal combustion engine.