JP2005307926A - Atmospheric pressure detection device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To renew atmospheric pressure from suction pressure without using an atmospheric pressure sensor in a system in which an intake air control valve is arranged on the upstream side or the downstream side of a throttle valve provided in an air intake passage of every cylinder of an independent air-intake type internal combustion engine. <P>SOLUTION: In the case where the degree TA of throttle opening of the throttle valve 4 detected by a throttle opening degree sensor 23 is within a predetermined operation range, where the number of revolutions NE of the internal combustion engine 1 detected by a crank angle sensor 25 is within a predetermined operation range, where the intake air control valve opening degree ACVA of the intake air control valve 9 detected by an intake air control valve opening degree sensor 28 exceeds a predetermined opening degree, or where the suction pressure PM detected by a suction pressure sensor 22 exceeds a predetermined value, the atmospheric pressure is renewed from the suction pressure PM. As described above, without directly detecting the atmospheric pressure, it is possible to adequately renew the atmospheric pressure only by sequentially taking in the suction pressure PM when the predetermined operation conditions or the like are satisfied. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an atmospheric pressure detection device for an internal combustion engine that detects an atmospheric pressure of an ambient environment based on a detected value of an intake pressure in an intake passage for each cylinder of an independent intake internal combustion engine. This can be reflected in the fuel injection amount supplied to each cylinder of the internal combustion engine.

  2. Description of the Related Art Conventionally, it is known to maintain an operating state of an internal combustion engine satisfactorily by detecting the atmospheric pressure in the environment surrounding the internal combustion engine and correcting the fuel injection amount according to the atmospheric pressure, for example. At this time, in the system in which the atmospheric pressure sensor is arranged and the atmospheric pressure is detected from the detection result, there is a problem that the cost increase is unavoidable and the price of the entire system is increased.

As what copes with this, what was disclosed by Unexamined-Japanese-Patent No. 2002-30981 is known. This technique shows a technique for detecting the atmospheric pressure without incurring an increase in cost based on a detection value of an intake pressure sensor disposed in an intake passage of an internal combustion engine.
JP 2002-30981 A (pages 2 to 3)

  By the way, in the above, when applied to an internal combustion engine with independent intake, the intake pressure of a specific cylinder is detected by an intake pressure sensor disposed in the intake passage (engine intake pipe), and based on the intake pressure. To seek atmospheric pressure.

  Here, in a system in which intake control valves are arranged in parallel for the purpose of adjusting the intake flow velocity upstream or downstream of the throttle valve provided in the intake passage of the internal combustion engine, the atmospheric pressure is reduced based on the intake pressure. There was nothing to calculate. In such a system, when the intake control valve is in a closed state, there is a phenomenon that the intake pressure becomes a value far from the atmospheric pressure even if the throttle valve is open and close to the exhaust stroke. At this time, even if an attempt is made to obtain the atmospheric pressure based on the intake pressure, an incorrect atmospheric pressure is calculated.For example, the correction according to the atmospheric pressure with respect to the fuel injection amount becomes inappropriate, and the operating state of the internal combustion engine is rejected. There was a problem of becoming unstable.

  Therefore, the present invention has been made to solve such a problem, and an intake control valve is disposed upstream or downstream of a throttle valve disposed in an intake passage for each cylinder of an internal combustion engine of independent intake. An object of the present invention is to provide an atmospheric pressure detection device for an internal combustion engine that can accurately update the atmospheric pressure based on the intake pressure without using an atmospheric pressure sensor.

  According to the atmospheric pressure detection apparatus for an internal combustion engine of claim 1, in the internal combustion engine composed of four cylinders of independent intake, the throttle opening of the throttle valve detected by the throttle opening detection means is in the predetermined operating range. Or when the engine rotational speed of the internal combustion engine detected by the rotational speed detection means is in a predetermined operating range, or disposed upstream or downstream of the throttle valve detected by the intake control valve opening degree detection means The intake control valve opening degree of the intake control valve that controls the intake air amount introduced into each cylinder of the internal combustion engine in cooperation with the opening / closing timing of the throttle valve is over the predetermined opening degree and is on the open side, or the intake pressure At least one condition among the cases where the intake pressure downstream of the throttle valve disposed in the intake passage for each cylinder detected by the detection means exceeds a predetermined value and becomes high When it is satisfied, based on the intake pressure downstream of the throttle valve disposed in an intake passage of each cylinder detected by the intake pressure detecting unit, the atmospheric pressure is updated by atmospheric updating means. As a result, the atmospheric pressure is accurately updated by simply taking in the intake pressure when the predetermined operating conditions are satisfied without directly detecting the atmospheric pressure.

  In the atmospheric pressure updating means in the atmospheric pressure detecting device for an internal combustion engine according to claim 2, when the intake control valve opening degree by the intake control valve opening degree detecting means is fully closed or less than a predetermined opening degree, the intake pressure is almost equal to the atmospheric pressure. Assuming that there is no equal operating state, updating of the atmospheric pressure based on the intake pressure is prohibited. This prevents an erroneous update of the atmospheric pressure due to the intake pressure.

  In the atmospheric pressure update means in the atmospheric pressure detection apparatus for an internal combustion engine according to claim 3, when the abnormality of the intake control valve or the intake control valve opening degree detection means is known, the update of the atmospheric pressure based on the intake pressure is prohibited. This prevents an erroneous update of the atmospheric pressure due to the intake pressure.

  In the atmospheric pressure update means in the atmospheric pressure detection device for an internal combustion engine according to claim 4, the intake control valve opening degree of the intake control valve by the intake control valve opening degree detection means in a period other than at least the intake stroke of the combustion cycle is a predetermined opening degree. When it is below, it is impossible to update the atmospheric pressure based on the intake pressure, assuming that there is no operation state in which the intake pressure is substantially equal to the atmospheric pressure. This prevents an erroneous update of the atmospheric pressure due to the intake pressure.

  In the atmospheric pressure update means in the atmospheric pressure detection device for an internal combustion engine according to claim 5, when the intake control valve or the intake control valve opening degree detection means is abnormal at least during a period other than the intake stroke in the combustion cycle, the intake pressure is high. Since the operating state that is substantially equal to the atmospheric pressure is not known, updating of the atmospheric pressure based on the intake pressure is prohibited. This prevents an erroneous update of the atmospheric pressure due to the intake pressure.

  In the atmospheric pressure update means in the atmospheric pressure detecting device for an internal combustion engine according to claim 6, it is an exhaust stroke period in an operation state in which the intake pressure in at least the intake stroke period of the combustion cycle is not more than a predetermined value. However, since the intake pressure cannot be expected to be substantially equal to the atmospheric pressure, updating of the atmospheric pressure based on the intake pressure is prohibited. This prevents an erroneous update of the atmospheric pressure due to the intake pressure.

  Hereinafter, the best mode for carrying out the present invention will be described based on examples.

  FIG. 1 is a schematic configuration diagram showing an internal combustion engine consisting of four-stroke two-cylinder with independent intake to which an atmospheric pressure detection device for an internal combustion engine according to an embodiment of the present invention is applied, and peripheral devices thereof. In this embodiment, two cylinders are assumed as a plurality of cylinders, but only one of them will be described.

  In FIG. 1, the internal combustion engine 1 is configured as a four-cycle two-cylinder (# 1 cylinder and # 2 cylinder) spark ignition type, and its intake air passes through an air cleaner 2, an intake passage 3, and a throttle valve 4 from the upstream side. The fuel is mixed with fuel injected from an injector (fuel injection valve) 5 in the intake passage 3 and supplied to the cylinder from the intake port 6 as an air-fuel mixture having a predetermined air-fuel ratio. An ignition plug 7 is disposed in the cylinder head of the internal combustion engine 1, and a high voltage is applied from the ignition coil / igniter 8 to the ignition plug 7 at each ignition timing, and the air-fuel mixture in the cylinder is ignited. The exhaust gas burned in the cylinder of the internal combustion engine 1 passes through the three-way catalyst 13 disposed on the downstream side of the exhaust passage 12 from the exhaust port 11 and is discharged into the atmosphere. Further, on the upstream side of the throttle valve 4 in the intake passage 3, in cooperation with the opening / closing timing of the throttle valve 4, the intake flow velocity on the downstream side of the throttle valve 4 is increased, and atomization of the fuel injected from the injector 5 is promoted. An intake control valve 9 is provided for this purpose.

  An intake air temperature sensor 21 is disposed in the air cleaner 2, and the intake air temperature THA [° C.] flowing into the air cleaner 2 is detected by the intake air temperature sensor 21. An intake pressure sensor 22 is disposed in the intake passage 3, and the intake pressure sensor 22 detects an intake pressure PM [kPa: kilopascals] on the downstream side of the throttle valve 4. The throttle valve 4 is provided with a throttle opening sensor 23, which detects the throttle opening TA [°] of the throttle valve 4. A water temperature sensor 24 is disposed in the cylinder block of the internal combustion engine 1, and the coolant temperature THW [° C.] in the internal combustion engine 1 is detected by the water temperature sensor 24.

  A crank angle sensor 25 is disposed on a crankshaft (not shown) of the internal combustion engine 1, and an engine rotational speed NE [rpm] of the internal combustion engine 1 is detected by a crank angle signal from the crank angle sensor 25. Further, a cam angle sensor 26 is disposed on the cam shaft (not shown) of the internal combustion engine 1, and the cam shaft rotation angle θ 2 [° CA (Crank Angle) of the internal combustion engine 1 is determined by the cam angle signal from the cam angle sensor 26. Corner)] is detected. Further, the intake control valve 9 is driven by an actuator 27 made of an electric motor, and the intake control valve opening degree ACVA of the intake control valve 9 is detected by an intake control valve opening degree sensor 28.

  On the other hand, the fuel pumped up from the fuel tank 31 by the fuel pump 32 is pumped in the order of the fuel pipe 33, the fuel filter 34, the fuel pipe 35, and the delivery pipe 36, and is supplied to the injector 5 of each cylinder. Excess fuel in the delivery pipe 36 is returned into the fuel tank 31 through a path of a pressure regulator 37 and a return pipe 38. The pressure regulator 37 adjusts the fuel pressure in the delivery pipe 36 so that the differential pressure between the fuel pressure (fuel pressure) in the delivery pipe 36 and the intake pressure becomes constant.

  An ECU (Electronic Control Unit) 40 that controls the operating state of the internal combustion engine 1 includes a CPU 41 as a central processing unit that executes various known arithmetic processes, a ROM 42 that stores a control program, a control map, and various data. The RAM 43, the B / U (backup) RAM 44, etc. are stored as logical operation circuits. The input port is used to input the detection signals from the various sensors and the power supply voltage VB [V: volts] from the battery 29. 45 and various actuators such as the injector 5, fuel pump 32, intake control valve 9, output port 46 that outputs each control signal to the ignition coil / igniter 8, and the like via a bus 47. The power supply voltage VB from the battery 29 is directly input into the ECU 40, divided, and then input to an A / D conversion port (not shown) to detect the voltage level.

  Next, based on the flowchart of FIG. 2 showing the processing procedure of the atmospheric pressure update in the surrounding environment of the internal combustion engine 1 by the CPU 41 in the ECU 40 used in the atmospheric pressure detection device of the internal combustion engine according to one embodiment of the present invention, This will be described with reference to FIGS. Here, FIG. 3 is an intake stroke → compression stroke → combustion (expansion) stroke → intake pressure PM [kPa] in an exhaust stroke, which is a combustion cycle of one cylinder of the internal combustion engine 1 composed of four cylinders of independent intake 4 cycles. It is a time chart which shows the behavior of. FIG. 4 is a time chart showing transition states of various sensor signals and various control amounts corresponding to the processing of FIG. This atmospheric pressure update routine is repeatedly executed by the CPU 41 every time a crank angle signal is input.

  In FIG. 2, first, in step S101, it is determined whether the engine speed NE of the internal combustion engine 1 is within a predetermined operating range based on the crank angle signal detected by the crank angle sensor 25. When the determination condition of step S101 is satisfied, that is, when the engine speed NE is in the predetermined operating range [from time t0 to time t1 (from ignition switch ON operation to immediately before cranking start) shown in FIG. 4, time t2 to time t3 (At the time of idle operation), from time t3 to time t4 (at the time of acceleration operation), from time t4 to time t5 (at the time of steady operation)], it is determined that the atmospheric pressure detection condition based on the intake pressure PM is satisfied, and the process proceeds to step S102 . In step S102, it is determined whether the throttle opening degree TA detected by the throttle opening degree sensor 23 is within a predetermined operation range. In this determination, the throttle opening degree TA is used as the load of the internal combustion engine 1, but the intake pressure PM detected by the intake pressure sensor 22 can also be used. When the determination condition in step S102 is satisfied, that is, when the throttle opening degree TA is in the predetermined operation range [after time t0 shown in FIG. 4], the process proceeds to step S103.

  In step S103, it is determined whether the intake control valve opening sensor 28 is not abnormal. When the determination condition of step S103 is not satisfied, that is, when the intake control valve opening sensor 28 is normal, the routine proceeds to step S104, where the intake control valve opening ACVA detected by the intake control valve opening sensor 28 is predetermined. It is determined whether the opening degree α (see FIG. 4) or less. If the determination condition in step S104 is not satisfied, that is, the intake control valve opening ACVA is larger than the predetermined opening α and the atmospheric pressure PA is appropriately updated based on the intake pressure PM, the process proceeds to step S105, and the exhaust stroke is performed. Is determined. If the determination condition in step S105 is satisfied, that is, the exhaust stroke, the routine proceeds to step S106, where the intake pressure PM detected by the intake pressure sensor 22 is taken.

  It should be noted that the intake pressure PM taking-in period is a combustion cycle corresponding to the throttle opening degree TA as the load of the internal combustion engine 1 and the like, as indicated by the solid and broken arrows as the detection period in FIG. In addition to the exhaust stroke, the combustion (expansion) stroke may be expanded to a part of the compression stroke. Further, the intake period of intake pressure PM may be changed depending on other operating conditions.

  Next, the process proceeds to step S107, and whether the basic intake pressure PMTP in the intake stroke used for calculating the fuel injection amount among the intake pressure PM detected by the intake pressure sensor 22 is equal to or less than a predetermined value β (see FIG. 3). Determined. When the determination condition of step S107 is not satisfied, that is, when the basic intake pressure PMTP is higher than the predetermined value β, the process proceeds to step S108, assuming that the intake pressure PM can be expected to rise to almost equal to the atmospheric pressure PA. It is determined whether the exhaust stroke has ended (immediately before the intake valve is opened). When the determination condition of step S108 is satisfied, that is, when the exhaust stroke ends, the routine proceeds to step S109, and the minimum value is subtracted from the maximum value in a predetermined period (for example, the exhaust stroke period) during the intake pressure PM intake period. It is determined whether the intake pressure deviation ΔPM is equal to or smaller than a predetermined value γ. When the determination condition of step S109 is satisfied, that is, when the intake pressure deviation ΔPM is as small as a predetermined value γ or less, the variation of the intake pressure PM taken in step S106 is small and stable, and the process proceeds to step S110. In step S110, if the intake pressure PM taken in is averaged and is different from the previous atmospheric pressure PA, the intake pressure PM obtained this time is updated as a new atmospheric pressure PA. Here, as a method of updating, the intake air pressure PM may be increased or decreased by a predetermined amount or replaced with an averaged value.

  On the other hand, when the determination condition of step S101 is not satisfied, that is, when the engine speed NE is not in the predetermined operation range [time t1 to time t2 shown in FIG. 4 (during cranking; affected by noise from the starter relay, etc. Easy period)], or the determination condition of step S102 is not satisfied, that is, when the throttle opening TA is, for example, during deceleration operation that continues from the sudden "closed" state, or the determination condition of step S103 is satisfied. That is, when the intake control valve opening sensor 28 is abnormal and its output voltage deviates from the voltage range that is normally output, or the determination condition of step S104 is satisfied, that is, the intake control valve opening sensor The intake control valve opening ACVA detected at 28 becomes smaller than the predetermined opening α (after time t5 shown in FIG. 4), and the atmospheric pressure PA based on the intake pressure PM is reduced. When the update is inappropriate or when the determination condition of step S105 is not satisfied, that is, when the exhaust stroke is not performed, or when the determination condition of step S107 is satisfied, that is, the basic intake pressure PMTP is lower than the predetermined value β and the intake pressure When an increase to a state where PM is substantially equal to the atmospheric pressure PA cannot be expected, or the determination condition of step S108 is not satisfied, that is, when the exhaust stroke is not completed, or the determination condition of step S109 is not satisfied, When the intake pressure deviation ΔPM is larger than the predetermined value γ and the fluctuation of the taken intake pressure PM is large and unstable, the renewal of the atmospheric pressure PA based on the intake pressure PM is prohibited. End the routine.

  As described above, when the intake control valve opening degree ACVA detected by the intake control valve opening degree sensor 28 is as small as the predetermined opening degree α or less, the opening degree of the intake control valve 9 due to the abnormality of the actuator 27 or the intake air Since the control valve opening sensor 28 itself may be abnormal, the update of the atmospheric pressure PA based on the intake pressure PM is prohibited.

  As described above, the atmospheric pressure detection device for the internal combustion engine of the present embodiment is introduced downstream of the throttle valve 4 provided in the intake passage 3 for each cylinder of the internal combustion engine 1 composed of independent intake 4-cycle 2-cylinders. An intake pressure sensor 22 as an intake pressure detection means for detecting an intake pressure PM that is a pressure of intake air, and a throttle opening as a throttle opening detection means for detecting a throttle opening TA that is an opening of the throttle valve 4. A degree sensor 23, a crank angle sensor 25 as a rotational speed detecting means for detecting the engine rotational speed NE of the internal combustion engine 1, and an upstream side of the throttle valve 4, and cooperates with the opening / closing timing of the throttle valve 4. An intake control valve 9 that controls the amount of intake air introduced into each cylinder of the internal combustion engine 1 and an intake control valve opening ACVA that is the opening of the intake control valve 9 are detected. The engine rotation detected by the crank angle sensor 25 when the intake control valve opening sensor 28 serving as the intake control valve opening detecting means and the throttle opening TA detected by the throttle opening sensor 23 are within a predetermined operating range. When the speed NE is in the predetermined operating range, when the intake control valve opening ACVA detected by the intake control valve opening sensor 28 exceeds the predetermined opening α, the intake pressure PM detected by the intake pressure sensor 22 is a predetermined value. When all the conditions for exceeding β are satisfied, an atmospheric pressure updating means that is achieved by the ECU 40 that updates the atmospheric pressure PA based on the intake pressure PM is provided.

  That is, the throttle opening degree TA detected by the throttle opening degree sensor 23 is in the predetermined operating range, the engine speed NE detected by the crank angle sensor 25 is in the predetermined operating range, and the intake control valve opening degree sensor 28 The intake control valve opening degree ACVA detected in step S4 is on the open side exceeding the predetermined opening degree α, and the intake pressure PM detected by the intake pressure sensor 22 is higher than the predetermined value β to satisfy all the conditions. The atmospheric pressure PA is updated based on the intake pressure PM detected by the intake pressure sensor 22. As a result, the atmospheric pressure PA can be accurately updated only by sequentially taking in the intake pressure PM when the predetermined operating condition is satisfied without directly detecting the atmospheric pressure PA.

  In the present embodiment, the case where all of the predetermined operating conditions described in parallel are satisfied has been described. However, when at least one of the conditions is satisfied, the intake pressure PM detected by the intake pressure sensor 22 is satisfied. Even if the atmospheric pressure PA is updated based on the above, the same effect can be obtained.

  Further, the atmospheric pressure updating means achieved by the ECU 40 of the atmospheric pressure detecting device for the internal combustion engine of the present embodiment is that the intake control valve opening ACVA detected by the intake control valve opening sensor 28 is fully closed or a predetermined opening. When it is less than or equal to α, the update of the atmospheric pressure PA based on the intake pressure PM is prohibited. That is, when the intake control valve opening ACVA by the intake control valve opening sensor 28 is fully closed or is equal to or less than the predetermined opening α, it is assumed that there is no operation state in which the intake pressure PM is substantially equal to the atmospheric pressure PA. Updating of the atmospheric pressure PA based on the atmospheric pressure PM is prohibited. As a result, an erroneous update of the atmospheric pressure PA due to the intake pressure PM can be prevented in advance.

  The atmospheric pressure updating means achieved by the ECU 40 of the atmospheric pressure detecting device for the internal combustion engine according to the present embodiment is based on the intake pressure PM when the intake control valve 9 or the intake control valve opening sensor 28 is abnormal. Barometric pressure PA renewal is prohibited. That is, when the abnormality of the intake control valve 9 or the intake control valve opening sensor 28 is known, the update of the atmospheric pressure PA based on the intake pressure PM is prohibited. As a result, an erroneous update of the atmospheric pressure PA due to the intake pressure PM can be prevented in advance.

  Further, the atmospheric pressure updating means achieved by the ECU 40 of the atmospheric pressure detecting device for the internal combustion engine of the present embodiment is that the intake pressure is at least when the intake control valve opening ACVA during a period other than the intake stroke is equal to or less than the predetermined opening α. Renewing atmospheric pressure PA based on PM is prohibited. That is, when the intake control valve opening ACVA of the intake control valve 9 by the intake control valve opening sensor 28 at least during a period other than the intake stroke is equal to or less than the predetermined opening α, the intake pressure PM is substantially equal to the atmospheric pressure PA. Assuming that there is no possible operating condition, updating of the atmospheric pressure PA based on the intake pressure PM is prohibited. As a result, an erroneous update of the atmospheric pressure PA due to the intake pressure PM can be prevented in advance.

  Furthermore, the atmospheric pressure update means achieved by the ECU 40 of the atmospheric pressure detection device for the internal combustion engine of the present embodiment is that the intake control valve 9 or the intake control valve opening sensor 28 is abnormal at least during a period other than the intake stroke. Sometimes, the atmospheric pressure PA update based on the intake pressure PM is prohibited. That is, when the intake control valve 9 or the intake control valve opening sensor 28 is abnormal at least during a period other than the intake stroke, the operating state in which the intake pressure PM is substantially equal to the atmospheric pressure PA is not known. Updating of the atmospheric pressure PA based on is prohibited. As a result, an erroneous update of the atmospheric pressure PA due to the intake pressure PM can be prevented in advance.

  In addition, the atmospheric pressure updating means achieved by the ECU 40 of the atmospheric pressure detecting device for the internal combustion engine of the present embodiment is the atmospheric pressure based on the intake pressure PM at least when the intake pressure PM in the intake stroke period is equal to or less than a predetermined value β. PA update is prohibited. In other words, at least in an operating state where the intake pressure PM in the intake stroke period is equal to or less than the predetermined value β, it is not expected that the intake pressure PM becomes substantially equal to the atmospheric pressure PA even in the exhaust stroke period. Updating of the atmospheric pressure PA based on the intake pressure PM is prohibited. As a result, an erroneous update of the atmospheric pressure PA due to the intake pressure PM can be prevented in advance.

  In the above embodiment, the intake control valve 9 is arranged upstream of the throttle valve 4. However, the present invention is not limited to this, and the intake control valve 9 is not limited to this. Even in the configuration in which the throttle valve 4 is disposed on the downstream side, the same action and lowering as in the above-described embodiment can be expected.

FIG. 1 is a schematic configuration diagram showing an internal combustion engine consisting of four-stroke two-cylinder with independent intake to which an atmospheric pressure detection device for an internal combustion engine according to an embodiment of the present invention is applied, and peripheral devices thereof. FIG. 2 is a flowchart showing the processing procedure of the atmospheric pressure calculation in the CPU in the ECU used in the atmospheric pressure detection device for an internal combustion engine according to one embodiment of the present invention. FIG. 3 is a time chart showing the intake pressure behavior in the combustion cycle of one of the four-cycle, two-cylinder internal combustion engines to which the atmospheric pressure detection device for an internal combustion engine according to one embodiment of the present invention is applied. It is a chart. FIG. 4 is a time chart showing transition states of various sensor signals and various control amounts corresponding to the processing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 3 Intake passage 4 Throttle valve 9 Intake control valve 22 Intake pressure sensor 23 Throttle opening sensor 25 Crank angle sensor 28 Intake control valve opening sensor 40 ECU (electronic control unit)

Claims (6)

An intake pressure detecting means for detecting an intake pressure which is a pressure of intake air introduced downstream of a throttle valve disposed in an intake passage for each cylinder in an internal combustion engine composed of four-cycle multiple cylinders of independent intake;
Throttle opening detection means for detecting the throttle opening which is the opening of the throttle valve;
A rotational speed detecting means for detecting an engine rotational speed of the internal combustion engine;
An intake control valve that is disposed upstream or downstream of the throttle valve and controls the amount of intake air introduced into each cylinder of the internal combustion engine in cooperation with the opening and closing timing of the throttle valve;
An intake control valve opening detecting means for detecting an intake control valve opening that is an opening of the intake control valve;
When the throttle opening detected by the throttle opening detecting means is in a predetermined operating range, or when the engine rotational speed detected by the rotational speed detecting means is in a predetermined operating range, or the intake control valve opening detecting When the intake control valve opening detected by the means exceeds a predetermined opening or when the intake pressure detected by the intake pressure detection means exceeds a predetermined value, the intake pressure An atmospheric pressure detecting device for an internal combustion engine, comprising: an atmospheric pressure updating means for updating the atmospheric pressure based on   The atmospheric pressure update means prohibits the atmospheric pressure update based on the intake pressure when the intake control valve opening detected by the intake control valve opening detection means is fully closed or less than a predetermined opening. The atmospheric pressure detection device for an internal combustion engine according to claim 1.   2. The internal combustion engine according to claim 1, wherein when the intake control valve or the intake control valve opening degree detection unit is abnormal, the atmospheric pressure update unit prohibits update of the atmospheric pressure based on the intake pressure. Atmospheric pressure detector.   2. The atmospheric pressure update unit according to claim 1, wherein the atmospheric pressure update unit prohibits the atmospheric pressure update based on the intake pressure when the intake control valve opening at least during a period other than the intake stroke is equal to or less than a predetermined opening. An atmospheric pressure detection device for an internal combustion engine.   The atmospheric pressure update means prohibits the atmospheric pressure update based on the intake pressure when the intake control valve or the intake control valve opening degree detection means is abnormal at least during a period other than the intake stroke. Item 2. An atmospheric pressure detection device for an internal combustion engine according to Item 1. 2. The atmospheric pressure detection of the internal combustion engine according to claim 1, wherein the atmospheric pressure update unit prohibits the atmospheric pressure update based on the intake pressure when at least the intake pressure in the intake stroke period is a predetermined value or less. apparatus.

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