JPH07208252A - Control device of internal combustion engine - Google Patents

Abstract

PURPOSE:To correctly measure the pressure of an intake pipe having an independent throttle valve for each cylinder with one pressure sensor. CONSTITUTION:The pressure in an intake pipe measured by one pressure sensor 13 through a throttle valve 4 which is independently arranged to each intake pipe 2 for each cylinder of the internal combustion engine, a communicating pipe 10 to be communicated with each intake pipe 2 on the downstream side, an idling speed control valve 11 which is interposed between a bypass passage 12 connected to the upstream side of the throttle valve 4 of the intake pipe 2 and adjusts the bypass air flow rate in the idling, and the communicating pipe 10 is corrected by the correction coefficient according to the parameters based on the operational condition of the internal combustion engine. Various controlled variables of the internal combustion engine are calculated based on the corrected pressure in the intake pipe. The reliability of the measured values of the pressure in the intake pipe is improved with the simple constitution, and various precise controls can be made in the internal combustion engine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine control device which has an independent intake system for each cylinder and calculates various control amounts by using intake pipe pressure.

[0002]

2. Description of the Related Art Conventionally, as a method for measuring the intake air amount of an internal combustion engine (engine), a method of directly measuring the intake air amount (volume or mass) and a parameter (correlation with changes in the intake air amount ( Some of them indirectly measure by measuring the intake pipe pressure or throttle opening).

[0003]

Here, there is known an internal combustion engine having an independent intake system that positively utilizes the pulsating effect in order to improve the charging efficiency of the intake air amount.

By the way, if the former method is adopted for such an internal combustion engine, the intake air amount cannot be accurately measured due to the influence of the pulsation. Further, when the latter method is adopted, various error factors occur and the engine control becomes unstable when the intake air amount is small and the like.

As a prior art document relating to the latter method, the one disclosed in Japanese Patent Publication No. 45782/1993 is known. With this one, the throttle opening α
In the method of controlling the fuel injection amount based on the engine rotation speed (rotation speed of the internal combustion engine) N, a so-called α-N method, the bypass air flow rate for idle speed control is estimated and estimated from the throttle opening. A technique is disclosed in which the intake air amount is corrected by the bypass air flow rate and the idle speed is appropriately controlled.

In this α-N method, the detection accuracy of the throttle opening is extremely important, and it is necessary to control the assembly angle between the throttle valve and the throttle opening sensor, the leakage flow rate from the machining gap of the throttle valve, and the like. . On the other hand, when measuring the intake pipe pressure, there are some points to be solved. First, since each intake pipe is independent, a pressure sensor installed in only one cylinder cannot follow a change during a transition. Therefore, if a pressure sensor is installed for each cylinder, the frequency of measurement increases, the control becomes complicated, and the cost increases.

Therefore, the present invention has been made to solve the above problems, and in an internal combustion engine having an independent intake system, the intake pipe pressure can be appropriately obtained even with one pressure sensor. Providing an internal combustion engine control device that makes it possible to perform accurate control of the internal combustion engine by making appropriate corrections to the parameters that cause the measured values to shift and making the measured values of intake pipe pressure reliable It is what

[0008]

According to a first aspect of the present invention, there is provided an internal combustion engine control device, wherein a throttle valve is provided independently in each intake pipe of each cylinder of the internal combustion engine, and each of the throttle valves is provided downstream of the throttle valve. An idle speed that is interposed between a communication pipe that communicates the intake pipe, a bypass passage that is connected to the intake pipe upstream of the throttle valve, and the communication pipe, and that adjusts a bypass air flow rate when the internal combustion engine is idle. A control valve, one pressure sensor that measures the intake pipe pressure in each intake pipe via the communication pipe, and control that calculates various control amounts of the internal combustion engine based on the intake pipe pressure measured by the pressure sensor And a quantity calculation means.

According to a second aspect of the present invention, there is provided an internal combustion engine control device, wherein a throttle valve independently arranged in each intake pipe of each cylinder of the internal combustion engine and a communication for communicating the intake pipe downstream of the throttle valve. Pipe, a bypass passage connected upstream of the throttle valve of the intake pipe, and the communication pipe, and an idle speed control valve for adjusting a bypass air flow rate when the internal combustion engine is idle, and the communication One pressure sensor for measuring the intake pipe pressure in each of the intake pipes via a pipe, and a pressure for correcting the intake pipe pressure measured by the pressure sensor with a correction coefficient according to a parameter based on the operating state of the internal combustion engine. Compensation means and control quantity calculation means for calculating various control quantities of the internal combustion engine based on the intake pipe pressure corrected by the pressure correction means are provided.

According to a third aspect of the present invention, in the internal combustion engine control device, in addition to the means provided in the second aspect, the pressure correction means includes:
The correction coefficient is calculated so that the corrected intake pipe pressure decreases as the engine speed decreases.

According to a fourth aspect of the present invention, in addition to the means provided in the second or third aspect, the internal combustion engine control system further comprises: the pressure correction means for correcting the intake pipe pressure after the bypass air flow rate is increased. The correction coefficient is calculated so that

According to a fifth aspect of the present invention, in addition to the means provided in any one of the first to fourth aspects, the internal combustion engine control system comprises one communication pipe, which is adjusted by the idle speed control valve. The bypass air flow rate is distributed to each of the intake pipes, and the intake pipe pressure is measured by the pressure sensor.

[0013]

According to the first aspect of the present invention, the bypass air flow rate during idling and the communication pipe that connects the intake pipes downstream of the throttle valve that is independently arranged in each intake pipe for each cylinder of the internal combustion engine is adjusted. The idle speed control valve communicates with the upstream side and the downstream side of the throttle valve. Therefore, even if the throttle valve is independently arranged in each intake pipe, the bypass air flow rate at the time of idling of each cylinder is adjusted by one idle speed control valve. Then, the intake pipe pressure in each intake pipe is measured by one pressure sensor via the communication pipe, and various control amounts of the internal combustion engine are calculated based on the measured values.

According to a second aspect of the present invention, the flow rate of the bypass air at the time of idling and the communication pipes communicating with the intake pipes on the downstream side of the throttle valve independently arranged in each intake pipe of each cylinder of the internal combustion engine is adjusted. The idle speed control valve communicates with the upstream side and the downstream side of the throttle valve. Therefore, even if the throttle valve is independently arranged in each intake pipe, the bypass air flow rate at the time of idling of each cylinder is adjusted by one idle speed control valve. Then, the intake pipe pressure in each intake pipe is measured by one pressure sensor via the communication pipe, and the intake pipe pressure is corrected by a correction coefficient according to a parameter based on the operating state of the internal combustion engine. Various control amounts of the internal combustion engine are calculated based on the correction values.

In addition to the function of claim 2, the pressure correcting means of the internal combustion engine controller according to claim 3 calculates the correction coefficient such that the corrected intake pipe pressure becomes smaller as the engine speed decreases. By doing so, the fluctuation of the intake pipe pressure is appropriately corrected.

The pressure correction means of the internal combustion engine control device according to a fourth aspect of the present invention is, in addition to the function of the second or third aspect, corrected so that the corrected intake pipe pressure becomes smaller as the bypass air flow rate increases. By calculating the coefficient, the fluctuation of the intake pipe pressure is appropriately corrected.

The communication pipe of the internal combustion engine controller according to claim 5 is
In addition to the effect of any one of claims 1 to 4, 1
It is made up of a book, and the bypass air flow rate is distributed to each intake pipe in a well-balanced manner, and the intake pipe pressure fluctuation can be easily measured by setting the pressure sensor at the measurement position.

[0018]

EXAMPLES The present invention will be described below based on specific examples.

FIG. 1 is a block diagram showing the periphery of an intake pipe of an internal combustion engine controller according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 is a head portion of an internal combustion engine composed of four cylinders # 1 to # 4, 2 is an intake pipe, and the intake pipe 2 is fixed to the head portion 1 with bolts or the like. . Reference numeral 4 denotes a throttle valve provided in each intake pipe 2 for each cylinder, which is provided independently of each intake pipe 2 so as not to interfere with it. Reference numeral 5 denotes a drive shaft for opening and closing the throttle valve 4, and in the present embodiment, the throttle valve 4 for all cylinders is driven collectively. Reference numeral 10 denotes a communication pipe, which is arranged on the downstream side where the intake air of each intake pipe 2 is throttled by the throttle valve 4, and communicates the intake passage of each intake pipe 2 on the downstream side of the throttle valve 4. Reference numeral 11 is an idle speed control valve, 12 is a bypass passage, and the idle speed control valve 11 adjusts a bypass air flow rate through the bypass passage 12 at the time of idling and distributes it during an intake process of each cylinder, and also between the cylinders at the time of idling. The intake air amount is averaged. Reference numeral 13 is a pressure sensor for measuring the intake pipe pressure, which is the negative pressure in the intake pipe. The pressure sensor 13 is connected to a hose with an opening in a part of the communication pipe 10. It is configured to measure the intake system pressure.

FIG. 2 is a block diagram showing an input / output signal system of the internal combustion engine controller according to the embodiment of the present invention.

In FIG. 2, 20 is a control module, and the control module 20 is mainly
An A / D converter 21 that takes in an analog signal, an input circuit 22 that takes in a digital signal, and a C as a central arithmetic processing circuit.
It comprises a PU 23, a ROM 24 storing a control program, a RAM 25 storing various data, and an output circuit 26 outputting a control signal.

The analog signal is the control module 2
0 A / D converter 21 sequentially A according to the timetable
The data is D / D converted, digitized, and stored in the storage area of the RAM 25 allocated for each signal source. As the analog signal, an intake pipe pressure signal from the pressure sensor 13, a throttle opening signal from a throttle sensor (not shown) that uses a potentiometer, and a cooling water temperature signal from a water temperature sensor (not shown) that uses a thermistor resistance change There are an intake air temperature signal from an intake air temperature sensor (not shown) and others, a battery voltage signal, a fuel pressure signal, a supercharger pressure signal, an oxygen sensor signal and the like.

The digital signal is read by the input circuit 22 of the control module 20 in a timer cycle routine executed at fixed time intervals to read the state of the input port and stored in the storage area of the RAM 25 allocated for each signal source in bit units. It The digital signals include a rotation angle signal, an electric load signal, an air conditioner operation signal and others, a reference angle signal, a starter switch signal, an idle switch signal and the like.

The control output of the control module 20 includes an ISC (Idle Speed Control) control signal for controlling the opening of a typical idle speed control valve 11 and a fuel injection valve (not shown). Fuel injection signal and ignition device (not shown) for controlling time and its timing
There is an ignition control signal for controlling the energization time and the ignition timing.

The ISC control signal has an open loop control mode according to the cooling water temperature in the warm-up process after starting and a feedback control mode according to various loads to the internal combustion engine at the time of idling after warm-up. The opening degree of the valve 11 is changed to control the idle speed.

The fuel injection signal and the ignition control signal are calculated by interpolating the intake air amount and the engine speed at the time of calculation based on a map in which the intake air amount and the engine speed are assigned as parameters. Here, the engine speed is calculated from the input cycle time of the rotation angle signal. For example, from a rotation angle sensor (not shown) that generates signals at equal intervals of 12 pulses per crankshaft rotation (360 ° CA), 30 ° C.
The required time is measured for each A. That is, (rotational speed)
Is (revolutions per unit time), so (engine revolutions)
= (Unit measurement angle ÷ 360 °) × (unit time) ÷ (measurement time). Specifically, if the time required for 60 ° CA is 0.01 seconds, (60 ÷ 360) × 60 ÷ 0.01
= 1000 (rpm). The unit measurement angle is preferably as small as possible in order to improve the responsiveness, but it is preferable to be set to about the ignition interval in order to cancel the speed change in the combustion cycle.

On the other hand, the intake air amount is estimated from the intake pipe pressure and the charging efficiency for each engine speed. That is, the amount of air taken in is determined by the difference between atmospheric pressure and intake pipe pressure, and the back pressure on the exhaust side, but the back pressure itself is difficult to measure, so the filling efficiency is measured beforehand for each intake pipe pressure and engine speed. Then, a map is created and the filling efficiency at that time is interpolated based on the measurement of the intake pipe pressure.

In this embodiment, the intake pipe pressure of the independent intake system is measured via the communication pipe 10. The measured intake pipe pressure is used for the bypass passage 12 which is ISC controlled when the internal combustion engine is at a low rotational speed such as during idling.
Since it is affected by the bypass air flow rate of, the bypass air flow rate (l /
The true intake pipe pressure is estimated by calculating and multiplying the correction coefficient for

FIG. 3 is a partial sectional view taken along the line AA of FIG. Here, when the engine speed is low, as shown in the time chart of FIG. 4, the intake pipe pressure change in each intake pipe 2 for each cylinder is intermittent. Referring to the flow of intake air in the communication pipe 10 at time t1 in FIG. 4, the bypass air from the idle speed control valve 11 flows through the port of the # 2 cylinder, which is the intake process, as shown by the solid line arrow in FIG. The air leaking from the ports of the other cylinders also flows in as shown by the broken line arrow in FIG. 3, thereby affecting the measurement value of the pressure sensor 13. By the way, when the engine speed increases, the communication pipe 1
Since the discharge capacity of the air in 0 increases and the pressure loss in the throttle state of the throttle valve increases, the pressure difference between the cylinders decreases and the amount of leaked air decreases. Therefore, as shown in FIG. 10, the true intake pipe pressure is estimated by calculating and multiplying the correction coefficient based on the measured values of the engine speed (rpm) and the intake pipe pressure (mmHg). As a result, EGR
It is possible to obtain accurate control parameters even when the usage area changes due to ON / OFF of the (Exhaust Gas Recirculation) mechanism.

In other words, as the error factors, for example, when one of the four cylinders is in the intake stroke, the other three cylinders are not in the intake stroke, and the intake pipe pressures are different and averaged in the communicating pipe 10. Since this value is measured by the pressure sensor 13, it becomes a relatively large value. In addition, the idle speed control valve 11
The flow rate of the bypass air changes depending on the opening degree of, and the intake pipe pressure is affected by the flow rate.

As a countermeasure against this, the idle speed control valve 11
9 for correcting the measurement error of the intake pipe pressure by the bypass air flow rate corresponding to the opening degree (the step number from the fully closed position in the stepping motor type, the energization duty ratio in the solenoid type) and the communication pipe 10. The intake pipe pressure measured by the pressure sensor 13 is corrected by providing the map shown in FIG. 10 for correcting the measurement error of the intake pipe pressure depending on the engine speed due to the amount of leaked air from the cylinder other than the intake stroke. Then, an appropriate intake pipe pressure for various controls is calculated. By calculating the control amount such as the fuel injection amount and the ignition timing based on the corrected intake pipe pressure, the measurement error of the bypass air flow rate, the intake pipe 2 from the intake pipe 2 of the cylinder other than the intake stroke via the communication pipe 10 are calculated. It is possible to correct the measurement error due to the leaked air amount. By using the intake pipe pressure in which the measurement error is corrected, a more appropriate fuel injection amount and ignition timing control amount can be obtained, so that the required control can be achieved.

Next, the control module 20 used in the internal combustion engine controller according to one embodiment of the present invention.
The processing procedure of the CPU 23 will be described with reference to the flowcharts of FIGS. 5, 6, 7, and 8.

FIG. 5 shows a time synchronization routine executed at regular time intervals.

First, as a digital input process, the register of the input port of the digital signal input circuit 22 is read in step S101. Next, the process proceeds to step S102, the logical product (AND) of the current value and the previous value of the digital signal is calculated, and the process proceeds to step S103.
When both the previous value and the current value are at the Hi level “1”, that is, the input signal corresponding to the bit having the Hi level “1” twice is set to “1” and the content of the corresponding storage area of the RAM 25 is updated. To do. Next, the process proceeds to step S104, and R
The previous value of AM25 is updated and prepared for the next time.

Next, as an analog input process, the process proceeds to step S105, where each analog input connected to each channel of the A / D converter 21 is read as a channel counter value provided corresponding to the number of channels. It
Next, in step S106, the read channel counter and the storage area of the RAM 25 are selected as the relative address read of the RAM 25, and the A / D conversion value of the predetermined channel is set to the address of the predetermined storage area of the RAM 25. Remembered. Then, the process proceeds to step S107, where A /
Upon completion of D conversion, the data latched in the register is read and the storage value in the RAM 25 is updated. Next, in step S108, the channel counter is incremented and the next channel is selected, and in step S109, it is determined whether the channel counter has exceeded the number of channels and is overflowing. Step S10
If the channel counter exceeds the predetermined value in step 9, the process proceeds to step S110, and the channel counter is initialized to the head address. Note that step S109
If there is no overflow in step S110, step S110 is skipped and step S111 is entered to select the channel of the A / D converter 21. Next, step S112.
Then, the A / D conversion process is started, and this routine is finished. In addition, as the time synchronization routine, there is an ISC output process for controlling the opening degree of the idle speed control valve 11 and the like.

FIG. 6 shows an angle synchronization routine which is started and executed each time a rotation angle signal is generated.

First, in step S201, the angle counter in which the number of times the angle signal has been input is factored is read. Next, in step S202, the current time input from the register that latches the time of the free-run timer at the same time as the input of the angle signal is read, and the time difference from the previous time of the input stored in the RAM 25 is calculated. Then in step S203
Then, the time difference calculated in step S202 is set as the required time between the fixed angles, and the storage area of the RAM 25 designated by the relative address with the angle counter is updated.
Next, the process proceeds to step S204, and the input current time is stored and updated in the RAM 25 as the previous time. Next, the process proceeds to step S205, and after the calculation of the required time is completed, the angle counter is incremented, and step S2
At 06, it is determined whether the number of angle pulses overflows. When the number of angle pulses overflows in step S206, the process proceeds to step S207 and the angle counter is initialized. Note that step S2
If there is no overflow at 06, step S20
7 is skipped, the process proceeds to step S208, and it is determined whether the reference angle signal is input. Step S20
If the reference angle signal is input in step S209, step S209
Then, the angle counter is initialized. This allows
By fixing the reference angle signal to a specific angle position, the required angle position can be known based on the angle counter for each subsequent angle signal input. When the reference angle signal is not input in step S208, step S209 is skipped and the process proceeds to step S210. Based on the angle counter value, it is determined in step S210 whether it is fuel injection timing, and if so, step S2
11, the fuel injection process is executed, and in step S212, it is determined whether or not it is the ignition timing, and if so, the ignition process is executed in step S213, and this routine is ended. If the timing is not reached in step S210 and step S212, this routine is ended without executing the fuel injection process or the ignition process.

FIG. 7 shows a main routine which is always and continuously processed except for the synchronous processing.

First, as the engine speed calculation, the required time updated in the angle synchronization routine is used to calculate the average time between the predetermined angles, so that it is indicated by the relative address of the angle counter stored in the RAM 25 in step S301. A predetermined number of required time values are sequentially read from the leading address. Next, the process proceeds to step S302, and the required time read in step S301 is added as the cycle time accumulation process. Next, the process proceeds to step S303, the time calculated in step S302 is converted into the engine speed, the process proceeds to step S304, and the engine speed value stored in the RAM 25 is updated.

Next, as the intake pipe pressure calculation, step S
After shifting to 305 and reading the intake pipe pressure value stored in the RAM 25, the routine proceeds to step S306, where a leak air correction coefficient = 1 is set as an initial value. Next, the routine proceeds to step S307, where it is determined whether the engine speed is equal to or higher than a predetermined speed. If the determination in step S307 is NO and is less than or equal to the predetermined rotation speed, step S308
The correction coefficient of the leakage air corresponding to the engine speed (rpm) is changed from the map of FIG. 10 (the smaller the intake pipe pressure, the smaller the corrected intake pipe pressure as the engine speed decreases). Calculated). Next, the process proceeds to step S309, and the correction coefficient of the storage area in the RAM 25 is updated. If the determination in step S307 is YES, steps S308 and S309 are skipped. Next, the process proceeds to step S310, and the bypass air flow rate (l
/ Min) from the map of FIG. 9 (when the intake pipe pressure is lower than atmospheric pressure, the smaller the value,
It is calculated such that the corrected intake pipe pressure becomes smaller as the bypass air flow rate increases. Then step S311
Then, the ISC flow rate correction coefficient in the storage area in the RAM 25 is updated. Then, the process proceeds to step S312, and the intake pipe pressure is corrected using each correction coefficient.

Using the highly reliable intake pipe pressure corrected and calculated in this way, for example, the ignition timing calculation and the fuel injection amount calculation shown in FIG. 8 are executed. First, as the ignition timing calculation, in step S313, it is determined whether the throttle valve 4 is fully closed and the engine speed is within a predetermined idle state. If it is determined to be idle,
The process proceeds to step S314, and the ignition timing is interpolated based on the idle ignition map (not shown) corresponding to the engine speed at that time. Next, in step S315, the ignition timing due to the electric load such as the air conditioner is interpolated as the idle load correction. On the other hand, if it is determined in step S313 that the engine is not in the idle state, the engine speed and the intake pipe pressure corrected as described above are read out in step S316, and the process proceeds to step S317, based on the base ignition map (not shown). The base ignition timing is interpolated.
After the processing of step S315 or step S317, the process proceeds to step S318, and the ignition timing correction amount based on the cooling water temperature is calculated as the cooling water temperature correction. Then, the process proceeds to step S319, and the above-described ignition timing correction amount is added to complete the ignition timing correction.

Next, as a fuel injection amount calculation, step S
At 320, it is determined whether the engine is starting. For example, if the engine speed is 300 rpm or less, it is assumed that the engine is starting.
In step S321, in order to facilitate the starting rotation, the increase amount of the fuel injection amount at the time of starting is interpolated from the starting amount increase map based on the cooling water temperature. Next in step S32
Shifting to 2, the correction process based on the engine speed of the fuel injection amount is executed. In this process, as the engine speed becomes higher, the engine speed stabilizes, and therefore the amount of increase in the fuel injection amount is corrected so as to decrease. Next, the process proceeds to step S323, and the correction process based on the elapsed time from the start is executed. In this process, since the engine temperature rises with the passage of time, the amount of increase in the fuel injection amount is corrected so as to decrease. On the other hand, if it is determined in step S320 that it is not the time of starting, the process proceeds to step S324, and the engine speed and the intake pipe pressure corrected and calculated as described above are read out, and step S3
25, the basic injection amount based on the engine speed and the intake pipe pressure is interpolated. Next, the process proceeds to step S326, and the injection amount correction based on the cooling water temperature is executed as the cooling water temperature correction. Then, the process proceeds to step S327,
Air-fuel ratio feedback (F / B) correction of the injection amount is executed based on an output signal from an oxygen sensor (not shown) that detects the oxygen concentration in the exhaust gas, and this main routine ends.

As described above, the internal combustion engine control apparatus according to the present embodiment has the throttle valve 4 independently arranged in each intake pipe 2 for each cylinder of the internal combustion engine, and each intake pipe downstream of the throttle valve 4. 2 is connected between the communication pipe 10, the bypass pipe 12 connected to the upstream side of the throttle valve 4 of the intake pipe 2, and the communication pipe 10, and adjusts the bypass air flow rate when the internal combustion engine is idle. The idle speed control valve 11, one pressure sensor 13 for measuring the intake pipe pressure in each intake pipe 2 via the communication pipe 10, and various controls of the internal combustion engine based on the intake pipe pressure measured by the pressure sensor 13. The control module 20 is provided with a control amount calculation means that is achieved by the control module 20 that calculates the amount, and this can be the embodiment of claim 1.

Therefore, the flow rate of the bypass air at the time of idling with the communication pipe 10 communicating with each intake pipe 2 on the downstream side of the throttle valve 4 independently arranged in each intake pipe 2 of each cylinder of the internal combustion engine is adjusted. The idle speed control valve 11 communicates the upstream side and the downstream side of the throttle valve 4. Therefore, even if the throttle valve 4 is independently provided in each intake pipe 2, the single idle speed control valve 11 adjusts the bypass air flow rate during idle of each cylinder. Then, the intake pipe pressure in each intake pipe 2 is measured by one pressure sensor 13 via the communication pipe 10, and various control amounts of the internal combustion engine are calculated by the control amount calculation means based on the measured values.

Therefore, even if the throttle valve 4 is independently arranged in each intake pipe 2 for each cylinder of the internal combustion engine, the throttle valve 4
The assembling accuracy and detection accuracy of the throttle opening do not affect the measurement of the intake pipe pressure, and the intake pipe pressure in each intake pipe 2 is appropriately measured by one pressure sensor 13 via the communication pipe 10. To be done.

Further, the internal combustion engine control system of the present embodiment has the throttle valve 4 independently arranged in each intake pipe 2 of each cylinder of the internal combustion engine, and each intake pipe 2 downstream of the throttle valve 4. An idle speed that is interposed between the communication pipe 10 that communicates with the bypass pipe 12 that is connected to the upstream side of the throttle valve 4 of the intake pipe 2 and the communication pipe 10, and that adjusts the bypass air flow rate during idling of the internal combustion engine. The control valve 11, one pressure sensor 13 for measuring the intake pipe pressure in each intake pipe 2 via the communication pipe 10, and the intake pipe pressure measured by the pressure sensor 13 as a parameter based on the operating state of the internal combustion engine. Of the internal combustion engine based on the pressure correction means that is achieved by the control module 20 that corrects the correction coefficient according to the above, and the intake pipe pressure that is corrected by the pressure correction means. It is intended to and a control amount calculation means to be achieved by Joule 20 may be an embodiment of claim 2 the same.

Therefore, the bypass air flow rate at the time of idling is adjusted with the communication pipe 10 that communicates each intake pipe 2 on the downstream side of the throttle valve 4 that is independently arranged in each intake pipe 2 for each cylinder of the internal combustion engine. The idle speed control valve 11 communicates the upstream side and the downstream side of the throttle valve 4. Therefore, even if the throttle valve 4 is independently provided in each intake pipe 2, the single idle speed control valve 11 adjusts the bypass air flow rate during idle of each cylinder. Then, the intake pipe pressure in each intake pipe 2 is measured by one pressure sensor 13 via the communication pipe 10, and the measured value is a correction coefficient according to a parameter based on the operating state of the internal combustion engine by the pressure correction means. The control amount calculation means calculates various control amounts of the internal combustion engine based on the corrected intake pipe pressure.

Therefore, even if the throttle valve 4 is independently arranged in each intake pipe 2 for each cylinder of the internal combustion engine, the throttle valve 4
The accuracy of assembling and detecting the throttle opening of 1 does not affect the measurement of the intake pipe pressure.
The intake pipe pressure in each intake pipe 2 is measured by one pressure sensor 13, and the parameter that causes the measured value to deviate in the operating state of the internal combustion engine is appropriately corrected. The reliability of the value is improved, and various kinds of precise control in the internal combustion engine are possible.

Further, the pressure correction means achieved by the control module 20 of the internal combustion engine control system of the present embodiment calculates the correction coefficient such that the corrected intake pipe pressure becomes smaller as the engine speed decreases. The present invention can be used as the embodiment of claim 3.

Therefore, the correction value of the pressure correction means becomes appropriate, and therefore the intake pipe pressure measured by the pressure sensor 13 becomes highly reliable.

Furthermore, the pressure correction means achieved in the control module 20 of the internal combustion engine control system of this embodiment calculates the correction coefficient so that the corrected intake pipe pressure becomes smaller as the bypass air flow rate increases. Is what
This can be the embodiment of claim 4.

Therefore, the correction value of the pressure correction means becomes appropriate, and therefore the intake pipe pressure measured by the pressure sensor 13 becomes highly reliable.

Furthermore, the communication pipe 10 of the internal combustion engine control system of the present embodiment is composed of one pipe, which distributes the bypass air flow rate adjusted by the idle speed control valve 11 to each intake pipe 2 and the intake air by the pressure sensor 13. This is the position where the pipe pressure is measured, and this can be the embodiment of claim 5.

Therefore, the bypass air flow rate adjusted by the idle speed control valve 11 and passing through the single communicating pipe 10 is ideally distributed, and the measurement position of the pressure sensor 13 can be made less susceptible to the pulsation of the internal combustion engine. .

Therefore, the intake pipe pressure measured by the pressure sensor 13 is stable and highly reliable.

By the way, if the measurement of the intake pipe pressure is performed in a time-synchronized manner, as shown in the time chart of FIG. 4, the measurement error may increase depending on the sampling timing when the suction process of the cylinder is switched. Therefore, when the continuous measured value of the intake pipe pressure is larger than the previous value by a predetermined value or more, updating to the measured value is prohibited. Then, a method may be used in which the intake pipe pressure value that does not include the measured ripple is used for control by multiplying the next determination value by a coefficient.

In the above embodiment, the intake pipe pressure is corrected by the bypass air flow rate adjusted by the idle speed control valve. However, the opening information of the idle speed control valve, which is a factor for determining the bypass air flow rate, is used. Alternatively, the intake pipe pressure may be corrected using the stroke information or the duty ratio of the control signal as a parameter.

Further, in the above embodiment, one communication pipe 10 is used.
ISC air (intake air for ISC control) is distributed at the same time as the measurement position of the intake pipe pressure, but in order to make the response delay of the intake pipe pressure smaller, in addition to the communication pipe 10 that distributes ISC air, The communication tube may be provided with a communication tube dedicated to pressure measurement.

[0060]

As described above, according to the internal combustion engine control apparatus of the first aspect, the intake pipes are provided downstream of the throttle valve independently arranged in each intake pipe of each cylinder of the internal combustion engine. The upstream and downstream sides of the throttle valve are communicated with each other by the communicating pipe and the idle speed control valve that adjusts the bypass air flow rate during idle, and the idle speed control valve controls the bypass air flow rate during idle for each cylinder. The intake pipe pressure in each intake pipe is measured by one pressure sensor via the communication pipe, and various control amounts of the internal combustion engine are calculated by the control amount calculation means based on the measured value. As described above, the intake pipes on the downstream side of the throttle valve are communicated with each other through the communication pipes, and a pressure sensor is provided for each cylinder in order to continuously measure the intake pipe pressure in each intake pipe with one pressure sensor. The cost is greatly reduced. Further, in this configuration, it is not necessary to switch the measurement order in synchronization with the crank angle for each cylinder, and it is not necessary to specially manage the assembling accuracy and the detecting accuracy of the throttle opening of the throttle valve.

According to the second aspect of the present invention, the internal combustion engine controller controls the intake pipe for each cylinder of the internal combustion engine at the time of idling with the communication pipe communicating with each intake pipe downstream of the throttle valve independently arranged. The idle speed control valve that adjusts the bypass air flow rate communicates with the upstream side and the downstream side of the throttle valve, and the idle speed control valve adjusts the bypass air flow rate during idle of each cylinder, and the intake pipes through the communication pipes. The intake pipe pressure in the pipe is measured by one pressure sensor, the measured value is corrected by a pressure correction means by a correction coefficient according to a parameter based on the operating state of the internal combustion engine, and control is performed based on the corrected intake pipe pressure. Various control amounts of the internal combustion engine are calculated by the amount calculation means. As described above, the intake pipes on the downstream side of the throttle valve are communicated with each other through the communication pipes, and a pressure sensor is provided for each cylinder in order to continuously measure the intake pipe pressure in each intake pipe with one pressure sensor. The cost is greatly reduced. Also,
With this configuration, it is not necessary to switch the measurement order in synchronization with the crank angle of each cylinder, and it is not necessary to specially manage the assembling accuracy and detection accuracy of the throttle opening of the throttle valve. Then, the intake pipe pressure measured by the pressure sensor is corrected based on the operating state of the internal combustion engine, and an appropriate intake pipe pressure for various controls is calculated. By calculating the control amount such as the fuel injection amount and the ignition timing based on the corrected intake pipe pressure, the measurement error of the bypass air flow rate and the leakage air from the intake pipe of the cylinder other than the intake stroke through the communication pipe are calculated. It is possible to correct the measurement error due to the quantity. By using the intake pipe pressure in which the measurement error is corrected, an appropriate fuel injection amount and ignition timing control amount can be obtained, so that required control can be achieved.

According to the pressure correcting means of the internal combustion engine controller of the third aspect, in addition to the effect of the second aspect, the correction coefficient is set so that the corrected intake pipe pressure becomes smaller as the engine speed decreases. By being calculated, the fluctuation of the intake pipe pressure is appropriately corrected, and the intake pipe pressure measured by the pressure sensor can be made highly reliable.

According to the pressure correction means of the internal combustion engine controller of claim 4, in addition to the effect of claim 2 or claim 3,
Since the correction coefficient is calculated so that the corrected intake pipe pressure becomes smaller as the bypass air flow rate increases, fluctuations in the intake pipe pressure are properly corrected, and the intake pipe pressure measured by the pressure sensor is reliable. It can be expensive.

According to the communication pipe of the internal combustion engine control device of claim 5, in addition to the effect of any one of claims 1 to 4, it is adjusted by an idle speed control valve and passed through one communication pipe. The bypass air flow rate is ideally distributed, the pulsation of the internal combustion engine is less likely to be affected even at the measurement position of the pressure sensor, and the intake pipe pressure measured by the pressure sensor can be made stable and highly reliable.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a mechanical configuration of an internal combustion engine controller according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a control module and input / output signals used in the internal combustion engine controller according to one embodiment of the present invention.

FIG. 3 is a partial cross-sectional view taken along the line AA of FIG.

FIG. 4 is a time chart showing a change in intake pipe pressure of each cylinder of the internal combustion engine controller according to the embodiment of the present invention.

FIG. 5 is a flow chart showing a time synchronization routine of the control module of the internal combustion engine controller according to the embodiment of the present invention.

FIG. 6 is a flowchart showing an angle synchronization routine of a control module of the internal combustion engine controller according to one embodiment of the present invention.

FIG. 7 is a flowchart showing a main routine of a control module of the internal combustion engine controller according to the embodiment of the present invention.

FIG. 8 is a flowchart following FIG. 7 showing a main routine of a control module of the internal combustion engine controller according to one embodiment of the present invention.

FIG. 9 is a map showing a correction coefficient using as parameters the bypass air flow rate and the intake pipe pressure of the internal combustion engine controller according to the embodiment of the present invention.

FIG. 10 is a map showing a correction coefficient with the engine speed and the intake pipe pressure as parameters of the internal combustion engine controller according to one embodiment of the present invention.

[Explanation of symbols]

 1 (internal combustion engine) head part 2 intake pipe 4 throttle valve 10 communication pipe 11 idle speed control valve 12 bypass passage 13 pressure sensor 20 control module 21 A / D converter 22 input circuit 23 CPU 26 output circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area F02P 5/15 F02P 5/15 B

Claims (5)

[Claims] 1. A throttle valve independently provided in each intake pipe for each cylinder of an internal combustion engine, a communication pipe communicating with each intake pipe downstream of the throttle valve, and a throttle valve for the intake pipe. An idle speed control valve that is interposed between a bypass passage connected to the upstream side of the internal combustion engine and the communication pipe, and that adjusts a bypass air flow rate during idling of the internal combustion engine; Internal combustion engine control, comprising: one pressure sensor for measuring intake pipe pressure; and control amount calculation means for calculating various control amounts of the internal combustion engine based on the intake pipe pressure measured by the pressure sensor. apparatus. 2. A throttle valve independently arranged in each intake pipe of each cylinder of an internal combustion engine, a communication pipe communicating with each intake pipe downstream of the throttle valve, and a throttle valve of the intake pipe. An idle speed control valve that is interposed between a bypass passage connected to the upstream side of the internal combustion engine and the communication pipe, and that adjusts a bypass air flow rate during idling of the internal combustion engine; One pressure sensor for measuring the intake pipe pressure, a pressure correction unit for correcting the intake pipe pressure measured by the pressure sensor with a correction coefficient according to a parameter based on the operating state of the internal combustion engine, and the pressure correction unit. An internal combustion engine control device, comprising: a control amount calculation means for calculating various control amounts of the internal combustion engine based on the corrected intake pipe pressure. 3. The internal combustion engine control according to claim 2, wherein the pressure correction means calculates the correction coefficient such that the corrected intake pipe pressure becomes smaller as the engine speed decreases. apparatus. 4. The pressure correction means calculates the correction coefficient so that the corrected intake pipe pressure becomes smaller as the bypass air flow rate increases.
Alternatively, the internal combustion engine controller according to claim 3. 5. The communication pipe is composed of a single pipe, which distributes a bypass air flow rate adjusted by the idle speed control valve to each of the intake pipes, and serves as a measurement position of the intake pipe pressure by the pressure sensor. Claim 1 to claim 4
The internal combustion engine control device according to claim 1.