JP7239505B2 - Failure detection device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a failure detection device for detecting failure of a sensor provided in an internal combustion engine, and more particularly to a failure detection device for detecting failure of an intake pressure sensor provided in an internal combustion engine.

In recent years, in response to the demand for improved running performance and environmental performance of vehicles, there have been proposals for engine control devices that control the operating conditions such as the number of revolutions of an internal combustion engine mounted on a vehicle. . Such an engine control device controls the fuel supply amount, intake air amount, ignition timing, etc. of the engine based on values calculated from detection signals of various sensors such as a temperature sensor, thereby controlling the operating state of the engine. We are hiring. However, when an abnormality such as failure occurs in these various sensors, an event may occur in which the operating state of the engine cannot be optimally controlled. Therefore, the operating state of the engine is optimally controlled by detecting such an abnormality and displaying a prompt to replace the parts.

In addition, the regulations regarding OBD (On Board Diagnostic), which is a vehicle failure diagnosis function, stipulate that abnormal conditions such as failures of various sensors installed in the vehicle should be detected and abnormal history information should be managed. there is Detection of abnormal conditions such as sensor failures in the OBD regulations is mandatory for four-wheeled vehicles, and tends to be mandatory for two-wheeled vehicles as well.

Under such circumstances, Patent Document 1 relates to a control device for a motorcycle and a vehicle. An intake pressure acquisition unit 12 that acquires the intake pressure, a rotation speed acquisition unit 13 that acquires the rotation speed of the engine, and an estimated opening that calculates the estimated opening of the electronically controlled throttle device based on the intake pressure and the rotation speed. A calculation unit 14, a use opening determination unit 16 that determines an opening to be used as a feedback value based on the estimated opening when the actual opening satisfies the failure condition, and a use opening determining unit 16 when the actual opening satisfies the failure condition. and a target opening determination unit 17 that restricts generation of a target opening exceeding a predetermined upper limit value.

JP 2015-45284 A

However, according to the study of the present inventor, the configuration disclosed in Patent Document 1 is intended to control the electronically controlled throttle device even if a problem occurs in the throttle position sensor. Assuming the device, it focuses on the fact that there is a correlation between the opening of the throttle valve and the intake pressure, and does not disclose any specific configuration for an inexpensive mechanical throttle device.

Further, according to the studies of the present inventors, in the mechanical throttle device, the throttle valve is mechanically driven, so it is considered necessary to detect an abnormal state such as failure of the intake pressure sensor. In addition, in the mechanical throttle device, in consideration of the improvement of cold startability and the improvement of idling stability, the throttle valve is bypassed in addition to the original intake passage, and the upstream and downstream sides are Therefore, it is common to add a bypass passage that communicates with the upstream side of the intake pressure detection part of the intake pressure sensor, and to adopt a configuration that adjusts the inflow amount of the intake air passing through the bypass passage. Even if such a bypass passage is adopted, it is considered necessary to detect an abnormal state such as failure of the intake pressure sensor with high accuracy.

Further, according to further studies by the present inventors, when such a bypass passage is adopted, the intake pressure detected by the intake pressure sensor is detected when the throttle valve is opened at a low or medium opening. Since the opening and closing of the bypass passage has a relatively large effect on the value, for example, when the throttle valve is fully closed, which is the lowest degree of opening, the detection of abnormal conditions such as failure of the intake pressure sensor should be stopped. However, this leads to a decrease in the chances of detecting an abnormal state, so there is room for improvement.

Further, according to further studies by the present inventors, when such a bypass passage is adopted, a so-called load pressure is estimated from the relationship between the degree of opening of the bypass passage, the engine speed, and the degree of opening of the throttle valve. Since it is also possible to make an estimation, an estimated value of the intake pressure obtained in advance is compared with an actually measured value of the intake pressure detected by the intake pressure sensor. It is also possible to determine that the intake pressure sensor is in an abnormal state such as failure. However, according to such a configuration, it is necessary to handle three types of parameters, namely, the degree of opening of the bypass passage, the number of engine revolutions, and the degree of opening of the throttle valve, a plurality of times. As a result, the amount of data obtained increases, which leads to an increase in cost, etc., especially for motorcycles, which are required to be inexpensive, so there is room for improvement.

The present invention has been made through the above studies, and has a simple configuration that suppresses costs so that it can be appropriately adopted in vehicles such as motorcycles, etc., and accurately detects a failure of an intake pressure sensor. An object of the present invention is to provide a practical failure detection device capable of

In order to achieve the above objects, the present invention provides a failure detection device having a failure detection unit for detecting a failure of a sensor provided in an internal combustion engine, wherein the sensor detects an amount of intake air drawn into a combustion chamber of the internal combustion engine. an opening degree sensor for detecting an opening degree of a valve body which is movably provided inside an inflowing intake pipe and which opens and closes the intake pipe and adjusts the amount of intake air; and a rotation sensor for detecting the number of revolutions of the internal combustion engine, and the intake pipe communicates between the upstream side of the valve body and the downstream side of the valve body. A bypass passage is provided, and the bypass passage is provided with a bypass valve that opens and closes the bypass passage to adjust the amount of the intake air flowing into the bypass passage. The bypass valve is moved according to a control amount by which the actuator is driven and controlled, and the failure detection unit measures the pressure detected by the pressure sensor and the measured pressure. , and an estimated pressure as a value corresponding to the rotational speed, the opening degree, and the control amount when the measured pressure is detected, and the absolute value of the difference between the measured pressure and the estimated pressure is If it is larger than a predetermined threshold value, it is determined that a failure has occurred in the pressure sensor , and the estimated pressure is the pressure on the downstream side of the intake pipe in advance corresponding to the rotational speed and the opening degree. It is calculated from the reference estimated pressure which is a value obtained by detection, and as the opening degree when calculating the estimated pressure, a corrected opening degree obtained by correcting the opening degree according to the control amount is used . The failure detection device further has a storage unit storing the reference estimated pressure, and the failure detection unit refers to the reference estimated pressure in the storage unit to determine the rotational speed when the measured pressure is detected. and calculating the corrected opening used as the opening when calculating the estimated pressure, which is the value of the reference estimated pressure corresponding to the opening, by correcting the opening according to the control amount. The bypass valve is moved by a movement amount proportional to the control amount to open and close so as to increase or decrease the passage area of the bypass passage, and the movement amount of the bypass valve is the magnitude of the pressure change amount. is the largest when the degree of opening of the valve body is fully closed, and the failure detection device stores the reference correction amount and the degree of influence coefficient in the storage unit, The reference correction amount adjusts the opening of the valve body from the fully closed opening to the reference opening, which is a predetermined value. A first reference ratio, which is a ratio of the first pressure change amount at which the pressure changes when the pressure is changed by the first opening amount, to the first opening amount, and the bypass valve at the fully closed opening degree. A second reference ratio, which is a ratio of a second pressure change amount at which the pressure changes when the pressure is moved to the movement amount and the first movement amount, is calculated in advance as a ratio of the influence degree coefficient is obtained corresponding to the second pressure change amount obtained corresponding to the rotation speed, the rotation speed and the opening degree of the valve body, and the bypass valve as the first movement amount. The corrected opening degree of the valve body is calculated in advance as a ratio of the change amount by which the pressure changes when the pressure is moved so as to be the reference correction amount, the movement amount of the bypass valve, and the degree of influence A first aspect is to be calculated by the sum of the product of the coefficient and the measured opening detected by the opening sensor .

Further, in addition to the first aspect, the present invention is characterized in that, in addition to the first aspect, the pressure on the downstream side of the intake pipe is changed corresponding to the number of revolutions and the degree of opening of the valve body, and the number of revolutions and the degree of opening, respectively. A second aspect is that the reference estimated pressure, which is the value obtained by detecting in advance, is prepared in the form of map data in accordance with the correspondence between them.

Further, the present invention is a failure detection device having a failure detection unit for detecting failure of a sensor provided in an internal combustion engine, wherein the sensor is located inside an intake pipe through which intake air flows into a combustion chamber of the internal combustion engine. an opening degree sensor for detecting the degree of opening of a valve element that is movably provided to open and close the intake pipe and adjust the amount of intake air; and a pressure sensor for detecting the pressure downstream of the valve element in the intake pipe. and a rotation sensor for detecting the rotation speed of the internal combustion engine, wherein the intake pipe is provided with a bypass passage that communicates between an upstream side of the valve body and a downstream side of the valve body, The bypass passage is provided with a bypass valve that opens and closes the bypass passage to adjust the amount of the intake air flowing into the bypass passage, and the bypass valve is driven and controlled to open and close the bypass passage. and the bypass valve is moved according to a control amount by which the actuator is driven and controlled, and the failure detection unit detects a measured pressure that is the pressure detected by the pressure sensor and and an estimated pressure as a value corresponding to the rotational speed, the opening degree, and the control amount, and the absolute value of the difference between the measured pressure and the estimated pressure is larger than a predetermined threshold and the estimated pressure is a value obtained by previously detecting the pressure on the downstream side of the intake pipe corresponding to the rotational speed and the degree of opening. is calculated from the reference estimated pressure, and a corrected opening obtained by correcting the opening according to the control amount is used as the opening when calculating the estimated pressure. A reference estimated pressure, which is an actual measured value of the pressure on the downstream side of the valve body, is measured corresponding to the rotational speed and the opening degree of the valve body, and Data indicating the correspondence relationship between the value of the rotation speed, the value of the opening, and the value of the reference estimated pressure is prepared in advance. The value of the estimated pressure is calculated from the value of the reference estimated pressure of the data, which is used as the value of the degree of opening, and the calculated value of the estimated pressure is stored in the storage unit. The bypass valve is moved by a movement amount proportional to the control amount and opens and closes so as to increase or decrease the passage area of the bypass passage, and the degree of influence of the movement amount of the bypass valve on the magnitude of the pressure change amount The coefficient is the largest when the opening of the valve body is the fully closed opening. The reference correction amount is calculated in advance using the influence degree coefficient, and the reference correction amount is obtained when the opening of the valve body is changed from the fully closed opening to the reference opening, which is a predetermined value, by the first opening amount. When the bypass valve is moved to the first movement amount at the first reference ratio, which is the ratio between the first pressure change amount by which the pressure changes and the first opening amount, and the fully closed opening amount It is calculated in advance as a ratio of the second pressure change amount by which the pressure changes and the second reference ratio that is the ratio of the first movement amount, and the influence degree coefficient is obtained corresponding to the rotation speed. The second pressure change amount is obtained corresponding to the rotation speed and the opening degree of the valve body, and the pressure is obtained when the bypass valve is moved to the first movement amount. The corrected opening degree of the valve body is the product of the reference correction amount, the movement amount of the bypass valve, and the influence degree coefficient, and the valve body's A third aspect is that it is calculated in advance by the sum of the opening degree and .

According to the failure detection device according to the first aspect of the present invention, the estimated pressure that the failure detection unit compares with the measured pressure detected by the pressure sensor is determined by the number of revolutions of the internal combustion engine and the valve body that opens and closes the intake pipe. is calculated from the reference estimated pressure, which is a value obtained by detecting the pressure downstream of the intake pipe in advance, corresponding to the degree of opening of the bypass passage. Since the corrected opening is used by correcting the opening of the valve body according to the control amount that drives and controls the actuator that moves the bypass valve that opens and closes the bypass valve, an increase in the number of data of the reference estimated pressure However, failure detection can be performed with practically sufficient accuracy. Thus, to provide a practical failure detection device capable of accurately detecting a failure of an intake pressure sensor with a simple configuration that suppresses costs so that it can be appropriately adopted in a vehicle such as a motorcycle. can be done.

Further, according to the failure detection device according to the first aspect of the present invention, the failure detection device further has a storage unit storing the reference estimated pressure, and refers to the reference estimated pressure in the storage unit so that the measured pressure is When calculating the estimated pressure, which is the value of the reference estimated pressure corresponding to the rotational speed of the internal combustion engine and the opening of the valve disc at the time of detection, the correction opening used as the opening of the valve disc is moved by moving the bypass valve. Since it is calculated by correcting the opening according to the control amount that drives the actuator to be driven and controlled, it is possible to calculate the estimated pressure from the reference estimated pressure in the storage unit and perform failure detection with practically sufficient accuracy. can be done.

Further, according to the failure detection device according to the first aspect of the present invention, the reference correction amount and the influence degree coefficient are stored in the storage unit, and the reference correction amount changes the opening degree of the valve body from the fully closed opening degree to the predetermined value. The first reference ratio, which is the ratio of the first pressure change amount at which the pressure changes when the pressure is changed by the first opening amount to the reference opening, and the first opening amount, and the bypass valve at the fully closed opening is the first It is calculated in advance as a ratio of the second reference ratio, which is the ratio of the first movement amount to the second pressure change amount at which the pressure changes when moving so as to be one movement amount, and the influence degree coefficient is , a second pressure change amount obtained corresponding to the number of revolutions of the internal combustion engine, a second amount of change in pressure obtained corresponding to the number of revolutions of the internal combustion engine and the degree of opening of the valve body, and the bypass valve to the first movement amount. The corrected opening of the valve body is calculated in advance as a ratio of the amount of change in pressure when the pressure is moved to Since it is calculated by the sum of the measured opening detected by and the reference correction amount and the influence degree coefficient in the storage unit, failure detection can be performed more reliably and accurately.

Further, according to the failure detection device according to the second aspect of the present invention, the downstream side of the intake pipe is detected in accordance with the rotational speed and the opening degree of the internal combustion engine, and the rotational speed and the opening degree of the internal combustion engine. The reference estimated pressure, which is a value obtained by detecting the pressure in advance, is prepared in the form of map data in accordance with the correspondence relationship between them. The number of measurements can be reduced.

Further, according to the failure detection device according to the third aspect of the present invention, the estimated pressure that the failure detection unit compares with the measured pressure detected by the pressure sensor depends on the number of revolutions of the internal combustion engine and the valve body that opens and closes the intake pipe. is calculated from the reference estimated pressure, which is a value obtained by detecting the pressure downstream of the intake pipe in advance, corresponding to the degree of opening of the bypass passage. Since the corrected opening is used by correcting the opening of the valve body according to the control amount that drives and controls the actuator that moves the bypass valve that opens and closes the bypass valve, an increase in the number of data of the reference estimated pressure In addition, it is possible to detect failures with sufficient accuracy for practical use. Therefore, it is possible to accurately detect failure of an intake pressure sensor with a simple configuration that suppresses costs so that it can be appropriately adopted in vehicles such as motorcycles. It is possible to provide a practical failure detection device that can perform detection, and the failure detection device further has a storage unit that stores the estimated pressure, and the rotational speed of the internal combustion engine and the opening of the valve body. Correspondingly, the reference estimated pressure, which is the measured value of the pressure on the downstream side of the valve body, is measured, and data indicating the correspondence relationship between the rotational speed value of the internal combustion engine, the opening value, and the reference estimated pressure value. is prepared in advance and the actuator that moves the bypass valve is driven and controlled according to the control amount. Since the pressure value is calculated in advance and the calculated estimated pressure value is stored in the storage unit, failure detection can be performed with practically sufficient accuracy using the estimated pressure in the storage unit.

Further, according to the failure detection device according to the third aspect of the present invention, the correction opening is calculated in advance using the reference correction amount and the influence degree coefficient, and the reference correction amount is the valve body opening. A first reference ratio, which is the ratio of the first opening amount and the first pressure change amount at which the pressure changes when the pressure is changed from the closed opening amount to the reference opening amount, which is a predetermined value, and fully closed open. Calculated in advance as a ratio of the second reference ratio, which is the ratio of the first movement amount to the second pressure change amount at which the pressure changes when the bypass valve is moved to the first movement amount in degrees and the influence degree coefficient is obtained corresponding to the second pressure change amount obtained corresponding to the rotation speed of the internal combustion engine, the rotation speed of the internal combustion engine and the opening degree of the valve body, and the bypass valve is first is calculated in advance as a ratio of the amount of change in pressure when moved to a movement amount of , and the correction opening of the valve body is the reference correction amount, the movement amount of the bypass valve, and the degree of influence coefficient. Since it is calculated in advance by the sum of the product and the opening degree to be measured, the reference correction amount and the influence degree coefficient can be calculated in advance without storing them in the storage unit, so that they can be more reliably calculated. Failure detection can be performed with high accuracy.

FIG. 1 is a schematic diagram showing a failure detection device according to an embodiment of the present invention together with an internal combustion engine to which it is applied. FIG. 2 is a block diagram showing the configuration of the failure detection device according to this embodiment. FIG. 3A is a block diagram showing the detailed configuration of the failure detection device according to the present embodiment, and FIG. FIG. 10 is a graph for explaining the concept of calculation of the coefficient of degree of influence on intensity; FIG. FIG. 4 is a flowchart for explaining an example of the flow of butterfly opening degree correction processing in the failure detection device according to the present embodiment. FIG. 5 is a flowchart for explaining an example of the flow of failure detection processing for the intake pressure sensor and the atmospheric pressure sensor additionally executed by the failure detection device according to the present embodiment. FIG. 6 is a flowchart for explaining an example of the flow of failure detection processing for an intake pressure sensor and an atmospheric pressure sensor additionally executed by the failure detection device according to the present embodiment.

Hereinafter, a failure detection device according to an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

[Engine configuration]
First, referring to FIG. 1, the configuration of an engine, which is an internal combustion engine, to which a failure detection device according to an embodiment of the present invention is applied will be described.

FIG. 1 is a schematic diagram showing a failure detection device according to the present embodiment together with an engine, which is an internal combustion engine to which it is applied.

As shown in FIG. 1, the failure detection device in the present embodiment is typically included in part of an ECU (Electronic Control Unit) 100, and the engine 1 to which the ECU 100 is applied is typically shown in the figure. The engine is an internal combustion engine mounted on a vehicle such as a motorcycle (not shown), and includes a cylinder block 2 having only one cylinder 2a, which is representatively illustrated. A piston 3 is arranged inside the cylinder 2a. Piston 3 is connected to crankshaft 5 via connecting rod 4 . The crankshaft 5 is provided with a reluctor 6 that rotates coaxially therewith.

In the cylinder block 2, by detecting the teeth formed on the outer peripheral surface of the reluctor 6 that rotates with the rotation of the crankshaft 5, the rotation speed of the crankshaft 5 is determined as the rotation speed of the engine 1 (engine speed). A crank angle sensor 7 is provided for detection as NE. The crank angle sensor 7 inputs to the ECU 100 an electrical signal indicating the detected engine speed NE.

The inner wall surface of the cylinder block 2 and the upper surface of the piston 3 cooperate to define a combustion chamber 8 of the cylinder 2a. The cylinder block 2 is provided with a spark plug 9 that ignites a mixture of fuel and air in the combustion chamber 8 . The cylinder block 2 is assembled with an intake pipe 10 into which the intake air taken into the combustion chamber 8 flows. An intake valve 11 that opens and closes the opening 10a of the intake pipe 10 that opens to the combustion chamber 8 is provided at the opening 10a.

A mechanical throttle valve 12 is movably provided inside the intake pipe 10 to open and close the intake pipe 10 to adjust the amount of intake air. The throttle valve 12 is directly driven by the driver via an operation wire or the like mechanically connected to an accelerator operation member such as an accelerator grip operated by the driver. Although not shown, the intake pipe 10 between the throttle valve 12 and the intake valve 11 is provided with an injector for injecting fuel to supply the fuel to the combustion chamber 8 .

The intake pipe 10 is equipped with a butterfly opening sensor 13 that detects the opening of the throttle valve 12 as a butterfly opening TH, and a pressure in the intake pipe 10 on the downstream side of the throttle valve 12 as an intake pressure (measurement pressure) PB. An intake pressure sensor 14 for detecting is provided. The butterfly opening sensor 13 and the intake pressure sensor 14 respectively input electric signals indicating the detected butterfly opening TH and the intake pressure PB to the ECU 100 .

The intake pipe 10 is provided with a bypass passage 15 that communicates between the upstream side of the throttle valve 12 and the downstream side of the throttle valve 12 . The bypass passage 15 is provided with a bypass valve 16 that opens and closes the bypass passage 15 to adjust the amount of intake air flowing into the bypass passage 15 . The bypass valve 16 is operated to open and close the bypass passage 15 by a bypass adjustment motor (stepping motor) 17 driven and controlled by the ECU 100. is linearly reciprocated in the bypass passage 15 between the fully closed position. Thus, the engine 1 is provided with a mechanical throttle device.

An exhaust pipe 18 that communicates with the combustion chamber 8 is assembled to the cylinder block 2 . An exhaust valve 19 that opens and closes the opening 18a of the exhaust pipe 18 that opens to the combustion chamber 8 is provided at the opening 18a.

[Configuration of failure detection device]
Next, referring to FIG. 2 and FIG. 3 in addition to FIG. 1, the configuration of the failure detection device according to the present embodiment will be described.

FIG. 2 is a block diagram showing the configuration of the failure detection device according to this embodiment. FIG. 3A is a block diagram showing the detailed configuration of the failure detection device according to the present embodiment, and FIG. FIG. 10 is a graph for explaining the concept of calculation of the coefficient of degree of influence on intensity; FIG. In addition, FIG.3(b) has shown as an example which set engine rotation speed to 5000 rpm.

As shown in FIG. 2, the failure detection device S in this embodiment forms a part of the ECU 100 electrically connected to the crank angle sensor 7, the butterfly opening sensor 13, and the intake pressure sensor 14. , the ECU 100 includes a control unit 110 and a failure detection unit 120, each of which is shown as a functional block.

The control unit 110 controls the engine speed NE indicated by the electrical signal input from the crank angle sensor 7, the butterfly opening TH indicated by the electrical signal input from the butterfly opening sensor 13, and the electrical signal input from the intake pressure sensor 14. and the atmospheric pressure PA indicated by an electrical signal input from an atmospheric pressure sensor (air pressure sensor around the engine) (not shown). The operating state of the engine 1 is controlled by controlling . The controller 110 also includes a motor controller (drive controller) 111 and a driver 112 . A motor control unit 111 drives and controls a bypass adjustment motor (actuator) 17 via a driver 112 based on the engine speed NE, the butterfly opening TH, the intake pressure PB, and the atmospheric pressure PA, thereby opening the bypass passage 15. Bypass valve 16 is moved to open and close. In this embodiment, the bypass valve 16 is moved by a movement amount proportional to the number of steps (control amount) stp of the bypass adjustment motor 17 input from the motor control unit 111 to increase or decrease the cross-sectional area of the bypass passage 15. It is opened and closed like this. The motor control unit 111 inputs an electric signal indicating the number of steps stp of the bypass adjustment motor 17 to the failure detection unit 120 .

As shown in FIGS. 2 and 3, the failure detection unit 120 functions as the failure detection device S of the present embodiment, and includes a memory 121, an internal pressure estimation unit 122, and a comparison/determination unit 123, and a crank angle sensor. 7. Detect failure of butterfly opening sensor 13 and pressure sensor 14 .

The memory 121 is composed of a nonvolatile storage device that stores control programs and control data, and stores data such as a reference correction amount 121a, a reference map 121b, and an influence level table 121c. The reference correction amount 121a, the reference map 121b, and the influence degree table 121c may be shared data common to a vehicle having the same specifications as the vehicle equipped with the failure detection device S according to the present embodiment. may be individual data prepared for each vehicle in which the failure detection device S100 is mounted.

Here, the reference correction amount 121a is set in advance by the reference number of steps of the bypass valve 16 of the bypass adjusting motor 17 (the number of steps for defining the position of the bypass valve 16 for setting the engine speed NE to the idle speed). The intake when the butterfly opening TH is changed from the fully closed opening that minimizes the passage cross-sectional area of the intake pipe 10 to the reference opening that is a predetermined value by the first opening amount. The first reference ratio, which is the ratio of the first pressure change amount that is the amount of change in the atmospheric pressure PB (the amount of change per unit opening of the butterfly opening TH) to the first opening amount, and the butterfly opening TH is the fully closed A second pressure change amount, which is the amount of change in the intake pressure PB when the bypass valve 16 is moved to the first movement amount when the opening is at the opening, and the first movement amount, which is the ratio of the second pressure change amount. It is calculated as a value of the ratio between the two reference ratios and is stored in the memory 121 . The reference opening of the butterfly opening TH is typically close to the fully closed opening, and means the opening at which the intake pressure PB is stably detected. This corresponds to an opening degree of about 5°. Further, the first movement amount of the bypass valve 16 typically includes a fully closed position where the bypass valve 16 fully closes the bypass passage 15 and a fully open position where the bypass valve 16 fully opens the bypass passage 15. means the amount of movement between Also, the first pressure change amount and the second pressure change amount are each obtained by setting the engine speed NE to typically the idling speed.

The reference map 121b is the value of the engine speed NE and the value of the butterfly opening TH, and the values of the intake pressure PB obtained corresponding to the value of the engine speed NE and the value of the butterfly opening TH. , are prepared in the form of map data according to their corresponding relationship and stored in the memory 121 . Note that the reference map 121b may be a reference table in the form of table data instead of the form of map data, if necessary.

The degree of influence table 121c shows in advance the intake pressure PB when the bypass valve 16 is moved to the first movement amount corresponding to the engine speed NE when the butterfly opening TH is the fully closed opening. (the second pressure change amount obtained corresponding to the engine speed NE), the engine speed NE, and the butterfly opening TH so that the bypass valve 16 is moved to the first movement amount. The amount of change in the intake pressure PB when moved and the value of the effect degree coefficient calculated as a ratio correspond to the value of the butterfly opening TH, in the form of table data according to the correspondence relationship between them. , and stored in the memory 121 for each value of the butterfly opening TH. This is a coefficient that indicates the degree of influence on the size. As one example, as shown in FIG. ° and 10°, it becomes smaller than 100%, and when the butterfly opening TH reaches 30°, it becomes almost 0%. FIG. 3(b) shows, as an example, a curve representing the relationship between the butterfly opening TH and the intake pressure PB when the engine speed NE is set to 5000 rpm. A curve L2 represents the relationship when the bypass valve 16 is at the idle reference opening, and a curve L3 represents the relationship when the bypass valve 16 is fully open. Here, the difference between the value of the intake pressure PB indicated by the curve L1 and the value of the intake pressure PB indicated by the curve L3 at each butterfly opening TH corresponds to the value of the influence degree coefficient. The value of the influence degree coefficient corresponding to the value of the butterfly opening TH at a predetermined value of the engine speed NE constitutes one table data. Note that the influence degree table 121c may be an influence degree map in the form of map data prepared for each of a plurality of values of the engine speed NE instead of the form of table data, if necessary.

The internal pressure estimator 122 receives an electrical signal indicating the engine speed NE from the crank angle sensor 7, an electrical signal indicating the butterfly opening TH from the butterfly opening sensor 13, and the step number stp of the bypass adjustment motor 17 from the motor control unit 111. is input, and the internal pressure estimating unit 122 calculates the engine rotation speed when the intake pressure PB is detected based on the engine speed NE, the butterfly opening TH, and the reference map 121b stored in the memory 121. The estimated pressure is calculated by referring to the value of the reference estimated pressure corresponding to the value of the number NE and the value of the butterfly opening TH, and using this referred value as the value of the estimated pressure. The internal pressure estimating section 122 calculates the estimated pressure in this way when performing so-called load estimation, and an electric signal indicating the estimated pressure calculated in this way is input to the comparing/determining section 123 .

The internal pressure estimator 122 also includes a corrected opening degree calculator 122a. The corrected opening degree calculation unit 122a executes a butterfly opening degree correction process of correcting the butterfly opening degree TH according to the number of steps stp, which is the control amount of the bypass adjustment motor 17, and calculating the corrected opening degree. Specifically, the value of the corrected opening degree is the value of the reference correction amount 121a and the value of the amount of movement of the bypass valve 16 (the deviation between the position of the bypass valve 16 in the reference number of steps and the current position of the bypass valve 16). value (that is, a value proportional to the deviation between the reference number of steps and the input number of steps defining the position of the bypass valve 16) and the value of the influence degree coefficient obtained from the influence degree table 121c, and the degree of opening of the butterfly. and the value of the butterfly opening TH detected by the sensor 13. Further, the corrected opening is used as the butterfly opening TH when calculating the estimated pressure corresponding to the engine speed NE and the butterfly opening TH when the intake pressure PB is detected. Note that the relationship between the amount of movement of the bypass valve 16 and the corrected opening of the butterfly opening TH may be determined in advance and converted into data, and the corrected opening of the butterfly opening TH may be calculated using this relationship.

An electric signal indicating the intake pressure PB from the intake pressure sensor 14 and an electric signal indicating the estimated pressure from the internal pressure estimating unit 122 are input to the comparing/determining unit 123, and the comparing/determining unit 123 compares the intake pressure PB and the estimated pressure. When the absolute value of the difference between the intake pressure PB and the estimated pressure is larger than a predetermined threshold, it is determined that the intake pressure sensor 14 has failed. When it is determined that the intake pressure sensor 14 has failed, the comparison/determination unit 123 displays information indicating that the intake pressure sensor 14 has failed on a display unit (not shown). It notifies that the atmospheric pressure sensor 14 has failed. The predetermined threshold value may be a variable value calculated based on various parameters indicating the operating state of the engine 1, such as the engine speed NE, instead of a fixed value.

[Butterfly opening correction process]
Next, with reference to FIG. 4, the operation of the failure detection device S when executing the butterfly opening correction process will be described.

FIG. 4 is a flowchart for explaining an example of the flow of butterfly opening correction processing in the failure detection device S according to this embodiment.

The flowchart shown in FIG. 4 starts when an ignition switch (not shown) is turned on and the failure detection device S is activated, and the butterfly opening correction process proceeds to step S1. The butterfly opening degree correction process is repeatedly executed at each predetermined control period while the failure detection device S is in operation.

In the process of step S1, the internal pressure estimating unit 122 receives input from the motor control unit 111 and a reference step number, which is the step number (control amount) stp of the motor control unit 111 for bringing the engine speed NE to the idle speed. The value of deviation from the current step number stp (proportional to the value of the amount of movement of the bypass valve 16) is calculated. Thereby, the process of step S1 is completed, and the butterfly opening correction process proceeds to the process of step S2.

In the process of step S<b>2 , the internal pressure estimator 122 reads the value of the reference correction amount 121 a stored in the memory 121 . Thereby, the process of step S2 is completed, and the butterfly opening correction process proceeds to the process of step S3.

In the process of step S3, the internal pressure estimating unit 122 determines the relationship between the butterfly opening TH and the degree of influence coefficient, and uses the influence degree table 121c stored in the memory 121 to determine the degree of opening of the butterfly input from the butterfly opening degree sensor 13. Read out the value of the influence degree coefficient corresponding to the value of degree TH. Thereby, the process of step S3 is completed, and the butterfly opening degree correction process proceeds to the process of step S4. Note that when using a plurality of influence degree maps in the form of map data prepared for each of a plurality of values of the engine speed NE, in the process of step S3, the internal pressure estimating unit 122 calculates The value of the engine speed NE inputted from the crank angle sensor 7 and the value of the engine speed NE inputted from the butterfly opening sensor 13 are obtained from the influence degree table 121c which shows the relationship between the butterfly opening TH and the influence degree coefficient and is stored in the memory 121. By reading the value of the influence degree coefficient corresponding to the value of the butterfly opening TH, the influence degree coefficient can be read with higher accuracy.

In the process of step S4, the correction opening calculation unit 122a calculates the value of the reference correction amount obtained in the process of step S2, the deviation value obtained in the process of step S1, and the degree of influence obtained in the process of step S3. The sum of the product of the coefficient value and the value of the butterfly opening TH obtained by input from the butterfly opening sensor 13 is calculated as the corrected opening value of the butterfly opening TH. Thereafter, the internal pressure estimator 122 obtains the value of the engine speed NE and the value of the corrected butterfly opening TH when the intake pressure sensor 14 detects the intake pressure PB from the reference map 121b stored in the memory 121. is read with reference to the value of the reference estimated pressure, and the read estimated pressure value is input to the comparison/determination unit 123 . As a result, the processing of step S4 is completed, and the current series of butterfly opening correction processing ends.

As is clear from the above description, in the failure detection device S according to the present embodiment, the estimated pressure that the failure detection unit 120 compares with the measured pressure PB is the rotational speed NE of the internal combustion engine 1 and the pressure of the valve body (throttle valve) 12. Corresponding to the degree of opening TH, it is calculated from the reference estimated pressure, which is a value obtained by detecting the pressure on the downstream side of the intake pipe 10 in advance. Since the corrected opening TH is corrected according to the control amount for driving and controlling the actuator 17 that moves the bypass valve 16 that opens and closes the bypass valve 16, an increase in the number of data of the reference estimated pressure However, failure detection can be performed with practically sufficient accuracy. As a result, it is possible to realize a practical configuration that can accurately detect a failure of the intake pressure sensor 14 with a simple configuration that suppresses costs so that it can be appropriately used in a vehicle such as a motorcycle. can.

Further, the failure detection device S according to the present embodiment further includes a storage unit 121 that stores the reference estimated pressure, and refers to the reference estimated pressure in the storage unit 121 to determine the internal combustion engine 1 when the measured pressure is detected. The actuator 17 that moves the bypass valve 16 drives the corrected opening used as the opening TH when calculating the estimated pressure, which is the value of the reference estimated pressure corresponding to the rotation speed NE of the valve body 12 and the opening TH of the valve body 12. Since it is calculated by correcting the opening according to the control amount to be controlled, the estimated pressure can be calculated from the reference estimated pressure in the storage unit 121 and the failure can be detected with practically sufficient accuracy. .

Further, in the failure detection device S according to the present embodiment, the reference correction amount and the degree of influence coefficient are stored in the storage unit 121, and the reference correction amount is a reference that the opening TH of the valve body 12 is a predetermined value from the fully closed opening. The first reference ratio, which is the ratio of the first pressure change amount at which the pressure PB changes when the pressure PB is changed to the opening by the first opening amount, and the first opening amount, and the bypass valve 16 at the fully closed opening. is calculated in advance as a ratio of the second reference ratio, which is the ratio of the second pressure change amount at which the pressure PB changes when the pressure PB is moved to the movement amount of and the first movement amount, and the influence degree coefficient is , a second pressure change amount obtained corresponding to the rotation speed NE of the internal combustion engine 1, and a second pressure change amount obtained corresponding to the rotation speed NE and the opening TH of the internal combustion engine 1, and the bypass valve 16 is moved to the first movement amount. The amount of change in the pressure PB when it is moved is calculated in advance as a ratio of the corrected opening degree of the valve body 12, and the corrected opening degree of the valve body 12 is the product of the reference correction amount, the movement amount of the bypass valve 16, and the degree of influence coefficient, and the opening Since it is calculated by the sum of the measured opening TH detected by the degree sensor 13 and the reference correction amount and the influence degree coefficient in the storage unit 121, more reliable and accurate failure detection is performed. be able to.

Further, in the failure detection device S according to the present embodiment, the pressure on the downstream side of the intake pipe 10 is adjusted in advance corresponding to the rotational speed NE and the opening TH of the valve body 12 of the internal combustion engine, and the rotational speed NE and the opening TH. Since the reference estimated pressure, which is a value obtained by detection, is prepared in the form of map data according to their corresponding relationship, the number of measurements for preparing data of the reference estimated pressure is reduced. be able to.

Up to this point, using the reference correction amount 121a, the reference map 121b indicating the reference estimated pressure, and the influence degree table 121c indicating the influence degree coefficient, which are stored in the memory 121 of the failure detection device S, the An example of calculating the estimated pressure according to the opening TH of the throttle valve 12 provided in the engine 1, the amount of movement of the bypass valve 16, and the rotation speed NE of the engine 1 has been described. Data up to the pressure value is stored directly in the memory 121 instead of the reference correction amount 121a, the reference map 121b, and the influence degree table 121c. may have been

That is, in this modified example, the estimated pressure is not calculated inside the failure detection device S using the reference correction amount 121a and the influence degree coefficient indicated by the influence degree table 121c, but is set at the stage of setting the failure detection device S. , is stored in the memory 121 of the failure detection device S in advance. The setting for storing such estimated pressure in the memory 121 is performed by using the same reference estimated pressure, reference correction amount and influence degree coefficient as described above in this embodiment.

Specifically, first, as in the case of the present embodiment, the engine 1 is assumed to be in operation in advance, and from the actual measurement values at that time, the reference correction amount 121a, the reference map 121b indicating the reference estimated pressure, and the degree of influence are calculated. An influence degree table 121 c indicating coefficients is obtained and prepared outside the memory 121 . Next, in the same manner as described above in the present embodiment, the product of the value of the reference correction amount 121a, the value of the movement amount of the bypass valve 16, and the value of the influence degree coefficient obtained from the influence degree table 121c, and the butterfly opening A required number of correction opening degree values are calculated from the sum of the value of the degree TH and the value of the degree TH. Then, in the same manner as described above in the present embodiment, the values of the required number of corrected opening degrees are used to refer to the value of the reference estimated pressure, and the value thus referred to is used as the value of the estimated pressure. , to calculate the required number of estimated pressure values. That is, if correction openings are calculated in advance for the number of desired combinations of the butterfly opening TH, rotation speed NE, and bypass valve movement amount and stored in the memory 121 of the failure detection device S of the actual vehicle, The calculation load for calculating the estimated pressure in the failure detection device S is greatly reduced.

As is clear from the above description, the failure detection device S according to this modification further includes a storage unit 121 that stores the estimated pressure, and corresponds to the rotational speed NE of the internal combustion engine 1 and the opening TH of the valve body 12. Then, the reference estimated pressure, which is the measured value of the pressure on the downstream side of the valve body 12, is measured, and data indicating the correspondence relationship between the value of the rotational speed NE, the value of the opening TH, and the value of the reference estimated pressure is obtained. The value of the corrected opening TH is prepared in advance and is obtained by correcting the opening TH in accordance with the control amount by which the actuator 17 that moves the bypass valve 16 is driven and controlled. The value of the estimated pressure is calculated in advance from the value, and the calculated estimated pressure value is stored in the storage unit 121. Therefore, the estimated pressure in the storage unit 121 is used to detect a failure with a practically sufficient accuracy. It can be carried out.

Further, in the failure detection device S according to the present modification, the correction opening is calculated in advance using the reference correction amount and the influence degree coefficient, and the reference correction amount is the opening TH of the valve body 12 and the fully closed opening. to the reference opening, which is a predetermined value, when the pressure changes by the first opening amount, the first reference ratio, which is the ratio of the first pressure change amount and the first opening amount, and the bypass at the fully closed opening It is calculated in advance as a ratio of the second reference ratio, which is the ratio of the first movement amount to the second pressure change amount by which the pressure PB changes when the valve 16 is moved to the first movement amount. , the influence degree coefficient is obtained corresponding to the second pressure change amount obtained corresponding to the rotation speed NE of the internal combustion engine 1, the rotation speed NE and the opening TH, and the first movement of the bypass valve 16. is calculated in advance as a ratio of the amount of change in the pressure PB when the pressure PB is moved to the amount of and the opening degree TH of the valve body 12. Therefore, these are calculated in advance without storing the reference correction amount and the degree of influence coefficient in the storage unit 121. Therefore, failure detection can be performed more reliably and accurately.

Furthermore, the failure detection device S in this embodiment including the above modifications may additionally perform failure detection of the intake pressure sensor 14 and an atmospheric pressure sensor (not shown). Here, while the engine 1 is stopped, the intake pressure sensor 14 detects the pressure equivalent to the atmospheric pressure, which is the pressure in the intake pipe. By detecting the atmospheric pressure and confirming each other's detected values, it becomes possible to detect their failures. However, if the vehicle in which the failure detection device S according to the present embodiment is mounted is a relatively lightweight vehicle such as a motorcycle, the driver may push the engine 1. Even if the engine does not explode completely, it will rotate and the intake pressure will fluctuate as a result. Therefore, in the failure detection device S according to the present embodiment, self-shutdown processing of the ECU 100 for storing necessary data when the engine 1 is in operation and when the engine 1 is stopped is performed in addition to when the engine 1 is stopped. By executing a failure detection process for detecting failures of the intake pressure sensor 14 and the atmospheric pressure sensor even when the engine is in the air pressure sensor 14, the chances of failure detection are increased, and failure detection of the intake pressure sensor 14 and the atmospheric pressure sensor is intended to be more reliable. is. 5 and 6, the operation of the failure detection device S when additionally performing failure detection of the intake pressure sensor 14 and an atmospheric pressure sensor (not shown) will be described. The failure detection device S may execute both of the processes shown in FIGS. 5 and 6, or may select and execute only one of the processes shown in FIGS.

FIG. 5 is a flowchart for explaining an example of the flow of failure detection processing for the intake pressure sensor 14 and the atmospheric pressure sensor additionally executed by the failure detection device S in this embodiment.

The flowchart shown in FIG. 5 starts when the failure detection device S is activated, and the failure detection process proceeds to step S11 in the initial process. The failure detection process is repeatedly executed at predetermined control cycles while the failure detection device S is in operation.

In the process of step S11, the failure detection device S determines whether or not the engine is stalling (while the engine 1 is stopped). As a result of determination, if the engine is stalling (step S11: Yes), the failure detection device S executes failure detection processing shown in FIG. On the other hand, if the engine is not stalled (step S11: No), the failure detection device S advances the failure detection process to step S12.

In the processing of step S12, the failure detection device S reads the history information stored in the memory 121 or the like and determines whether or not there is a failure history of the atmospheric pressure sensor. As a result of determination, if there is a failure history of the atmospheric pressure sensor (step S12: Yes), the failure detection device S advances the failure detection process to step S13. On the other hand, if there is no failure history of the atmospheric pressure sensor (step S12: No), the failure detection device S advances the failure detection process to step S21.

In the processing of step S13, the failure detection device S sets the state of the failure determination flag indicating the failure determination result of the intake pressure sensor 14 and the atmospheric pressure sensor to the undetermined state (PA: undetermined, PB: undetermined). Thereby, the process of step S13 is completed, and the failure detection process proceeds to the process of step S14.

In the processing of step S14, the failure detection device S determines whether or not the intake pressure sensor 14 is out of order based on the fluctuation state of the intake pressure PB detected during engine operation after the engine 1 is started and the post-start processing is started. determine. If the intake pressure sensor 14 is normal (step S14: normal), the failure detection device S advances the failure detection process to step S16. On the other hand, if the intake pressure sensor 14 fails because the intake pressure sensor 14 detects a change in the intake pressure PB that is less than the predetermined level or does not detect a change in the intake pressure PB (step S14: failure), the failure detection device S performs failure detection processing. to the process of step S15.

In the process of step S15, the failure detection device S sets the state of the failure determination flag of the intake pressure sensor 14 to the failure state, and sets the state of the failure determination flag of the atmospheric pressure sensor to the undetermined state. As a result, the processing of step S15 is completed, and the current series of failure detection processing ends.

In the process of step S16, the failure detection device S temporarily sets the state of the failure determination flag of the intake pressure sensor 14 to the normal state (PB: temporary normal), and sets the state of the failure determination flag of the atmospheric pressure sensor to the undetermined state. Set (PA: undetermined). As a result, the process of step S16 is completed, and the failure detection process proceeds to the process of step S17.

In the processing of step S17, the failure detection device S sets the failure determination flag of the intake pressure sensor 14 to the normal state in preparation for self-shutdown processing when the power supply of the failure detection device S is turned off when the engine 1 stops. Temporary setting is performed again, and the state of the failure determination flag of the atmospheric pressure sensor is again set to the undetermined state. Thereby, the process of step S17 is completed, and the failure detection process proceeds to the process of step S18. Note that the processing of this step can be omitted as necessary.

In the processing of step S18, the failure detection device S enters self-shutdown processing and determines whether or not the intake pressure PB detected by the intake pressure sensor 14 matches the atmospheric pressure PA detected by the atmospheric pressure sensor. Thereby, it is determined whether or not the intake pressure sensor 14 and the atmospheric pressure sensor are malfunctioning. When the intake pressure PB detected by the intake pressure sensor 14 and the atmospheric pressure PA detected by the atmospheric pressure sensor match as a result of determination, and the intake pressure sensor 14 and the atmospheric pressure sensor are normal (step S18: normal) , the failure detection device S advances the failure detection process to the process of step S19. On the other hand, if the intake pressure PB detected by the intake pressure sensor 14 and the atmospheric pressure PA detected by the atmospheric pressure sensor do not match and the intake pressure sensor 14 and the atmospheric pressure sensor are malfunctioning (step S18: failure). , the failure detection device S advances the failure detection process to the process of step S20.

In the process of step S19, the failure detection device S temporarily sets the state of the failure determination flag of the intake pressure sensor 14 to the normal state (PB: temporary normal), and sets the state of the failure determination flag of the atmospheric pressure sensor to the normal state. (PA: normal). As a result, the processing of step S19 is completed, and the current series of failure detection processing ends.

In the process of step S20, the failure detection device S sets the states of the failure determination flags of the intake pressure sensor 14 and the atmospheric pressure sensor to failure states (PA: failure, PB: failure). As a result, the processing of step S20 is completed, and the current series of failure detection processing ends.

In the process of step S21, the failure detection device S sets the state of the failure determination flag of the intake pressure sensor 14 to the undetermined state (PB: undetermined), and temporarily sets the state of the failure determination flag of the atmospheric pressure sensor to the normal state. Set (PA: temporary normal). Thereby, the process of step S21 is completed, and the failure detection process proceeds to the process of step S22.

In the process of step S22, the failure detection device S determines whether or not the intake pressure sensor 14 is out of order based on the fluctuation state of the intake pressure PB detected during engine operation after the engine 1 is started and the post-start process is started. determine. If the intake pressure sensor 14 is normal (step S22: normal), the failure detection device S advances the failure detection process to step S24. On the other hand, if the intake pressure sensor 14 fails because the intake pressure sensor 14 detects a change in the intake pressure PB that is less than the predetermined level or does not detect a change in the intake pressure PB (step S22: failure), the failure detection device S performs failure detection processing. to the process of step S23.

In the process of step S23, the failure detection device S sets the state of the failure determination flag of the intake pressure sensor 14 to the failure state (PB: failure), and temporarily sets the state of the failure determination flag of the atmospheric pressure sensor to the normal state. (PA: provisional normal). As a result, the processing of step S23 is completed, and the current series of failure detection processing ends.

In the processing of step S24, the failure detection device S provisionally sets the states of the failure determination flags of the intake pressure sensor 14 and the atmospheric pressure sensor to normal states (PA: temporary normal, PB: temporary normal). Thereby, the process of step S24 is completed, and the failure detection process proceeds to the process of step S25.

In the process of step S25, the failure detection device S determines whether the intake pressure sensor 14 has failed based on the estimated pressure calculated in the load estimation of the internal pressure estimating unit 122 and the intake pressure PB detected by the intake pressure sensor 14. determine whether or not As a result of determination, if the absolute value of the difference between the intake pressure PB and the estimated pressure is smaller than the predetermined threshold value and the intake pressure sensor 14 is normal (step S25: normal), the failure detection device S performs the failure detection process. Proceed to the processing of S26. On the other hand, if the absolute value of the difference between the intake pressure PB and the estimated pressure is larger than the predetermined threshold value and the intake pressure sensor 14 is faulty (step S25: fault), the fault detection device S performs the fault detection process in step S30. Proceed to the processing of

In the process of step S26, the failure detection device S provisionally sets the states of the failure determination flags of the intake pressure sensor 14 and the atmospheric pressure sensor to normal states (PA: temporary normal, PB: temporary normal). Thereby, the process of step S26 is completed, and the failure detection process proceeds to the process of step S27.

In the processing of step S27, the failure detection device S enters self-shutdown processing and determines whether or not the intake pressure PB detected by the intake pressure sensor 14 matches the atmospheric pressure PA detected by the atmospheric pressure sensor. Thereby, it is determined whether or not the intake pressure sensor 14 and the atmospheric pressure sensor are malfunctioning. As a result of determination, if the intake pressure PB detected by the intake pressure sensor 14 and the atmospheric pressure PA detected by the atmospheric pressure sensor match and the intake pressure sensor 14 and the atmospheric pressure sensor are normal (step S27: Normal), The failure detection device S advances the failure detection process to the process of step S28. On the other hand, if the intake pressure PB detected by the intake pressure sensor 14 and the atmospheric pressure PA detected by the atmospheric pressure sensor do not match and there is a possibility that both the intake pressure sensor 14 and the atmospheric pressure sensor are malfunctioning (step S27: failure), the failure detection device S advances the failure detection process to step S29.

In the processing of step S28, the failure detection device S sets the states of the failure determination flags of the intake pressure sensor 14 and the atmospheric pressure sensor to normal states (PA: normal, PB: normal). As a result, the processing of step S28 is completed, and the current series of failure detection processing ends.

In the process of step S29, the failure detection device S sets the states of the failure determination flags of the intake pressure sensor 14 and the atmospheric pressure sensor to the failure state (PA: failure, PB: failure). As a result, the processing of step S29 is completed, and the current series of failure detection processing ends.

In the process of step S30, the failure detection device S provisionally sets the states of the failure determination flags of the intake pressure sensor 14 and the atmospheric pressure sensor to failure states (PA: temporary failure, PB: temporary failure). Thereby, the process of step S30 is completed, and the failure detection process proceeds to the process of step S31.

In the processing of step S31, the failure detection device S enters self-shutdown processing and determines whether or not the intake pressure PB detected by the intake pressure sensor 14 and the atmospheric pressure PA detected by the atmospheric pressure sensor match. Thereby, it is determined whether or not the intake pressure sensor 14 and the atmospheric pressure sensor are malfunctioning. As a result of determination, if the intake pressure PB detected by the intake pressure sensor 14 and the atmospheric pressure PA detected by the atmospheric pressure sensor match and the intake pressure sensor 14 and the atmospheric pressure sensor are normal (step S31: Normal), The failure detection device S advances the failure detection process to the process of step S32. On the other hand, if the intake pressure PB detected by the intake pressure sensor 14 and the atmospheric pressure PA detected by the atmospheric pressure sensor do not match and there is a possibility that both the intake pressure sensor 14 and the atmospheric pressure sensor are malfunctioning (step S31: failure), the failure detection device S advances the failure detection process to step S33.

In the processing of step S32, the failure detection device S temporarily sets the failure determination flag of the intake pressure sensor 14 to the failure state (PB: temporary failure), and sets the failure determination flag of the atmospheric pressure sensor to the normal state ( PA: normal). As a result, the processing of step S32 is completed, and the current series of failure detection processing ends.

In the process of step S33, the failure detection device S sets the states of the failure determination flags of the intake pressure sensor 14 and the atmospheric pressure sensor to the failure state (PA: failure, PB: failure). As a result, the processing of step S33 is completed, and the current series of failure detection processing ends.

FIG. 6 is a flowchart for explaining an example of the flow of failure detection processing for the intake pressure sensor and the atmospheric pressure sensor additionally executed by the failure detection device S according to the present embodiment.

The flowchart shown in FIG. 6 starts when the failure detection device S is activated, and the failure detection process proceeds to step S41.

In the process of step S41, the failure detection device S determines whether or not the engine is stalling. As a result of determination, when the engine is stalling (step S41: Yes), the failure detection device S advances the failure detection process to step S42. On the other hand, if the engine is not stalled (step S41: No), the failure detection device S executes the failure detection process shown in FIG.

In the processing of step S42, the failure detection device S determines whether or not the intake pressure PB detected by the intake pressure sensor 14 and the atmospheric pressure PA detected by the atmospheric pressure sensor match. 14 and atmospheric pressure sensor are faulty. As a result of determination, if the intake pressure PB detected by the intake pressure sensor 14 and the atmospheric pressure PA detected by the atmospheric pressure sensor match and the intake pressure sensor 14 and the atmospheric pressure sensor are normal (step S42: Normal), The failure detection device S advances the failure detection process to step S43. On the other hand, if the intake pressure PB detected by the intake pressure sensor 14 and the atmospheric pressure PA detected by the atmospheric pressure sensor do not match and the intake pressure sensor 14 and the atmospheric pressure sensor are malfunctioning (step S42: failure), The failure detection device S advances the failure detection process to step S47.

In the processing of step S43, the failure detection device S temporarily sets the failure determination flag of the intake pressure sensor 14 to a normal state (PB: temporary normal), and sets the state of the failure determination flag of the atmospheric pressure sensor to a normal state ( PA: normal). Thereby, the process of step S43 is completed, and the failure detection process proceeds to the process of step S44.

In the processing of step S44, the failure detection device S detects the estimated pressure calculated in the load estimation of the internal pressure estimating unit 122 and the intake pressure PB detected by the intake pressure sensor 14 when the engine 1 starts and enters post-start processing. , it is determined whether the intake pressure sensor 14 is out of order. As a result of determination, if the absolute value of the difference between the intake pressure PB and the estimated pressure is smaller than the predetermined threshold value and the intake pressure sensor 14 is normal (step S44: normal), the failure detection device S performs the failure detection process. The process proceeds to S45. On the other hand, if the absolute value of the difference between the intake pressure PB and the estimated pressure is larger than the predetermined threshold value and the intake pressure sensor 14 has failed (step S44: failure), the failure detection device S performs failure detection processing at step S46. Proceed to the processing of

In the process of step S45, the failure detection device S sets the states of failure determination flags of the intake pressure sensor 14 and the atmospheric pressure sensor to normal states (PA: normal, PB: normal). As a result, the processing of step S45 is completed, and the current series of failure detection processing ends.

In the process of step S46, the failure detection device S sets the state of the failure determination flag of the intake pressure sensor 14 to the failure state (PB: failure), and sets the state of the failure determination flag of the atmospheric pressure sensor to the normal state ( PA: normal). As a result, the processing of step S46 is completed, and the current series of failure detection processing ends.

In the process of step S47, the failure detection device S provisionally sets the states of the failure determination flags of the intake pressure sensor 14 and the atmospheric pressure sensor to failure states (PA: temporary failure, PB: temporary failure). Thereby, the process of step S47 is completed, and the failure detection process proceeds to the process of step S48.

In the process of step S48, the failure detection device S determines whether or not the intake pressure sensor 14 is out of order based on the fluctuation state of the intake pressure PB detected in the post-start process during engine operation. If the intake pressure sensor 14 is normal (step S48: normal), the failure detection device S advances the failure detection process to step S49. On the other hand, if the intake pressure sensor 14 fails because the intake pressure sensor 14 detects a change in the intake pressure PB that is less than the predetermined level or does not detect a change in the intake pressure PB (step S48: failure), the failure detection device S performs failure detection processing. to the process of step S50.

In the process of step S49, the failure detection device S sets the states of the failure determination flags of the intake pressure sensor 14 and the atmospheric pressure sensor to failure states (PA: failure, PB: failure). As a result, the processing of step S49 is completed, and the current series of failure detection processing ends.

In the processing of step S50, the failure detection device S sets the state of the failure determination flag of the intake pressure sensor 14 to the failure state (PB: failure), and temporarily sets the state of the failure determination flag of the atmospheric pressure sensor to the failure state. (PA: temporary failure). As a result, the processing of step S50 is completed, and the current series of failure detection processing ends.

In the failure detection device S according to the present embodiment, including the above modified examples, the intake pressure sensor 14 and the large pressure sensor 14 are detected not only when the engine 1 is stopped, but also when the engine 1 is operating and during self-shutdown processing from operating to stopping. By executing the failure detection process for detecting the failure of the air pressure sensor, it is possible to perform accurate failure detection of the intake pressure sensor 14 and the atmospheric pressure sensor.

It should be noted that the present invention is not limited to the above-described embodiments in terms of the types, shapes, arrangements, numbers, etc. of the members, and the gist of the invention can be changed by appropriately replacing the constituent elements with those having equivalent effects. Needless to say, it can be changed as appropriate within a range that does not deviate.

INDUSTRIAL APPLICABILITY As described above, the present invention is a practical failure sensor that can accurately detect a failure of an intake pressure sensor with a simple configuration that suppresses costs so that it can be appropriately adopted in a vehicle such as a motorcycle. It is possible to provide a detection device, and it is expected to be widely applied to vehicles such as motorcycles due to its general-purpose and universal character.

DESCRIPTION OF SYMBOLS 1... Engine 2... Cylinder block 2a... Cylinder 3... Piston 4... Connecting rod 5... Crankshaft 6... Reluctor 7... Crank angle sensor 8... Combustion chamber 9... Spark plug 10... Intake pipe 10a... Opening 11... Intake valve 12... Throttle valve 13 Butterfly opening sensor 14 Intake pressure sensor 15 Bypass passage 16 Bypass valve 17 Bypass adjustment motor 18 Exhaust pipe 18a Opening 19 Exhaust valve 100 ECU (Electronic Control Unit)
DESCRIPTION OF SYMBOLS 110... Control part 111... Motor control part 112... Driver 120... Failure detection part 121... Memory 121a... Reference correction amount 121b... Influence degree table 121c... Reference map 122... Internal pressure estimation part 122a... Correction opening calculation part 123... Comparison determination Department

Claims (3)

A failure detection device having a failure detection unit that detects a failure of a sensor provided in an internal combustion engine,
The sensor is movably provided inside an intake pipe into which intake air is drawn into the combustion chamber of the internal combustion engine, and detects an opening degree of a valve body that opens and closes the intake pipe and adjusts the amount of the intake air. a sensor, a pressure sensor that detects the pressure downstream of the valve body in the intake pipe, and a rotation sensor that detects the rotation speed of the internal combustion engine,
The intake pipe is provided with a bypass passage that communicates between an upstream side of the valve body and a downstream side of the valve body,
The bypass passage is provided with a bypass valve that opens and closes the bypass passage to adjust the amount of the intake air flowing into the bypass passage,
the bypass valve is moved to open and close the bypass passage by an actuator that is driven and controlled;
The bypass valve is moved according to a control amount by which the actuator is driven and controlled,
The failure detection unit includes a measured pressure, which is the pressure detected by the pressure sensor, and an estimated pressure as a value corresponding to the rotational speed, the opening, and the control amount when the measured pressure is detected. , and determining that the pressure sensor has failed if the absolute value of the difference between the measured pressure and the estimated pressure is greater than a predetermined threshold;
The estimated pressure is calculated from a reference estimated pressure, which is a value obtained by previously detecting the pressure on the downstream side of the intake pipe, corresponding to the rotational speed and the opening,
A corrected opening obtained by correcting the opening according to the control amount is used as the opening when calculating the estimated pressure ,
The failure detection device further has a storage unit that stores the reference estimated pressure,
The failure detection unit refers to the reference estimated pressure in the storage unit, and determines the estimated pressure, which is the value of the reference estimated pressure corresponding to the rotational speed and the opening when the measured pressure is detected. when calculating, the corrected opening used as the opening is calculated by correcting the opening according to the control amount;
the bypass valve is moved by a movement amount proportional to the control amount to open and close so as to increase or decrease the flow area of the bypass passage;
The degree of influence coefficient by which the amount of movement of the bypass valve affects the magnitude of the amount of change in pressure is greatest when the degree of opening of the valve body is the degree of fully closed,
The failure detection device stores the reference correction amount and the influence degree coefficient in the storage unit,
The reference correction amount includes a first pressure change amount by which the pressure changes when the opening of the valve body is changed from the fully closed opening to a reference opening, which is a predetermined value, by a first opening amount. A first reference ratio that is a ratio to the first opening amount, and a second pressure change amount that changes the pressure when the bypass valve is moved to the first movement amount at the fully closed opening amount. Calculated in advance as a ratio of the second reference ratio, which is the ratio to the first movement amount,
The influence degree coefficient is obtained corresponding to the second pressure change amount obtained corresponding to the rotation speed, the rotation speed and the opening degree of the valve body, and the bypass valve to the first pressure change amount. is calculated in advance as a ratio of the amount of change in the pressure when it is moved so that the amount of movement is
The corrected opening degree of the valve body is calculated by the sum of the product of the reference correction amount, the movement amount of the bypass valve, and the effect degree coefficient, and the measured opening degree detected by the opening sensor. A failure detection device characterized by: The reference, which is the value obtained by previously detecting the pressure on the downstream side of the intake pipe corresponding to the rotation speed and the opening degree of the valve body, respectively. 2. The failure detection device according to claim 1 , wherein the estimated pressure and are prepared in the form of map data according to their corresponding relationship. A failure detection device having a failure detection unit that detects a failure of a sensor provided in an internal combustion engine,
The sensor is movably provided inside an intake pipe into which intake air is drawn into the combustion chamber of the internal combustion engine, and detects an opening degree of a valve body that opens and closes the intake pipe and adjusts the amount of the intake air. a sensor, a pressure sensor that detects the pressure downstream of the valve body in the intake pipe, and a rotation sensor that detects the rotation speed of the internal combustion engine,
The intake pipe is provided with a bypass passage that communicates between an upstream side of the valve body and a downstream side of the valve body,
The bypass passage is provided with a bypass valve that opens and closes the bypass passage to adjust the amount of the intake air flowing into the bypass passage,
the bypass valve is moved to open and close the bypass passage by an actuator that is driven and controlled;
The bypass valve is moved according to a control amount by which the actuator is driven and controlled,
The failure detection unit includes a measured pressure, which is the pressure detected by the pressure sensor, and an estimated pressure as a value corresponding to the rotational speed, the opening, and the control amount when the measured pressure is detected. , and determining that the pressure sensor has failed if the absolute value of the difference between the measured pressure and the estimated pressure is greater than a predetermined threshold;
The estimated pressure is calculated from a reference estimated pressure, which is a value obtained by previously detecting the pressure on the downstream side of the intake pipe, corresponding to the rotational speed and the opening,
A corrected opening obtained by correcting the opening according to the control amount is used as the opening when calculating the estimated pressure,
The failure detection device further has a storage unit that stores the estimated pressure,
A reference estimated pressure, which is a measured value of the pressure on the downstream side of the valve body, is measured corresponding to the rotational speed and the opening degree of the valve body, and the rotational speed value and the opening degree value are measured. and the value of the reference estimated pressure is prepared in advance, and the value of the corrected opening degree in which the opening degree is corrected in accordance with the control amount is used as the value of the opening degree. calculating the value of the estimated pressure from the value of the reference estimated pressure, storing the calculated value of the estimated pressure in the storage unit;
the bypass valve is moved by a movement amount proportional to the control amount to open and close so as to increase or decrease the flow area of the bypass passage;
The degree of influence coefficient by which the amount of movement of the bypass valve affects the magnitude of the amount of change in pressure is greatest when the degree of opening of the valve body is the degree of fully closed,
The correction opening degree is calculated in advance using the reference correction amount and the influence degree coefficient,
The reference correction amount includes a first pressure change amount by which the pressure changes when the opening of the valve body is changed from the fully closed opening to a reference opening, which is a predetermined value, by a first opening amount. A first reference ratio that is a ratio to the first opening amount, and a second pressure change amount that changes the pressure when the bypass valve is moved to the first movement amount at the fully closed opening amount. Calculated in advance as a ratio of the second reference ratio, which is the ratio to the first movement amount,
The influence degree coefficient is obtained corresponding to the second pressure change amount obtained corresponding to the rotation speed, the rotation speed and the opening degree of the valve body, and the bypass valve to the first pressure change amount. is calculated in advance as a ratio of the amount of change in the pressure when it is moved so that the amount of movement is
The corrected opening degree of the valve body is calculated in advance by the sum of the product of the reference correction amount, the movement amount of the bypass valve, and the effect degree coefficient, and the opening degree of the valve body. A failure detection device characterized by :

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