JPH09209810A - Failure detector for intake air control valve mechanism of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily detect the failure condition of an intake air control valve mechanism without accompanying complexation of construction and control, and externally display the failure condition rapidly and certainly, by composing a driving means control part and a failure judging part in an ECU, and externally displaying the failure condition of the intake air control valve mechanism on a display. SOLUTION: In this detector, engine operating condition detecting means 30 is arranged which judges whether or not an engine operating condition is in regular condition. In the case that the engine operating condition is judged that it is in regular condition, a driving means control part 34 in an electronic control unit(ECU) 22 makes an intake control valve to operate to change an opening/closing condition for failure judgement. A pressure sensor 4 detects pressure in an intake air pass when the intake control valve is opened/closed. When pressure difference in opening/closing periods between the detected pressure is at a predetermined value or more, failure judging means 42 in the ECU 22 judges that the engine operating condition is normal, and when pressure difference is smaller than the predetermined value, it judges that the engine operating condition is in failure condition. Displaying means 44 externally displays whether or not the engine operating condition is in failure condition on the basis of these judgement. Hereby, assured failure diagnosis can be carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure detection device for an intake control valve mechanism of an engine, and more particularly to an intake control valve provided with an intake control valve for generating a forced gas flow in a combustion chamber of an engine by performing an opening / closing operation. The present invention relates to a device that detects a failure state of a mechanism.

[0002]

2. Description of the Related Art Conventionally, an intake control valve for producing a gas flow such as a tumble flow in the combustion chamber is provided in the intake passage in order to improve the stability of combustion in the combustion chamber of an engine and the improvement of fuel consumption by promoting the combustion speed. The engine installed in is known. This intake control valve closes the intake passage to close the intake passage, changes the inflow direction of the air-fuel mixture into the combustion chamber of the engine, and causes a forced gas flow in the combustion chamber. is there.

The intake control valve is opened / closed by an actuator or the like which is an opening / closing drive means of the intake control valve according to the operating state of the engine. However, there is a possibility that the intake control valve may not actually be opened or closed due to a failure of the actuator or a malfunction of the intake control valve.

For example, a control command for closing the intake control valve in accordance with the operating state of the engine is an electronic control device (hereinafter,
ECU. ) Is output to the actuator, it is determined that the intake control valve is in the closed state, and the engine ignition timing, air-fuel ratio, etc. are set when the intake control valve is closed in order to bring the engine into an appropriate operating state. It is controlled based on the data of.

However, if the intake control valve is not opening / closing due to a failure of the actuator or the like, the accuracy of engine operation control may be impaired.

In order to solve the above problems, Japanese Patent Laid-Open No. 62-276244 discloses an actuator for driving an intake control valve provided with an ON / OFF switch, and an ON / OFF signal from this switch controls intake. Faults are diagnosed by detecting defective valve opening and closing operations.

[0007]

However, in the above-mentioned conventional technique, the reliability or durability of the switch becomes a problem, and by providing the ON / OFF switch, the mounting work of the ON / OFF switch is increased and the entire device is This will lead to soaring costs. Further, particularly in an engine having a plurality of cylinder heads such as a V-type engine and a horizontally opposed engine, a plurality of actuators are structurally required, and therefore a switch must be provided for each actuator, and the cost is also reduced. High will be invited.

The present invention has been made to solve the above problems, and its purpose is to easily detect a failure state of an intake control valve mechanism without complicating the configuration and control, and An object of the present invention is to provide a failure detection device for an intake control valve mechanism of an engine, which is capable of displaying a failure state.

[0009]

In order to achieve the above object, a failure detecting device for an intake control valve mechanism of an engine according to claim 1 of the present invention is such that an engine operating state is first detected by an engine operating state detecting means. Or not. Then, in the steady state, the intake control valve is caused to perform an open / closed state change operation to determine the failure of the intake control valve mechanism, and the pressure in the intake passage at the time of opening / closing is detected by the open / close state change operation. To do. Then, the failure determination unit determines whether or not the opening / closing operation of the intake control valve is normally performed based on the pressure difference between the two pressures. That is, in response to the opening / closing operation, when the pressure difference in the intake passage at the time of opening / closing the intake control valve is equal to or more than a predetermined value, it is determined as a normal state,
If it is smaller than the predetermined value, it is judged as a failure state.

This is because, for example, when the intake control valve is operated to change from the closed state to the open state, the intake air flow rate of the engine is increased and the pressure (absolute pressure) in the intake passage is greater when the intake valve is open than when it is closed. Becomes smaller. Similarly, when the intake control valve is operated from the open state to the closed state, the pressure in the intake passage is higher when the intake passage is closed. Therefore, when the intake control valve normally performs the open / closed state changing operation, the pressure difference between when the intake passage is open and when the intake passage is closed is a predetermined value or more. Therefore, it is judged whether or not the opening / closing operation of the intake control valve is reliably performed by detecting and comparing the pressure in the intake passage at the time of opening / closing by the opening / closing state changing operation of the intake control valve. It is possible to detect the failure of the control valve.

Further, by providing the display means for externally displaying the failure state of the intake control valve mechanism, for example, an engine operator or the like can quickly and easily recognize whether or not the intake control valve has a failure. You can

According to a second aspect of the present invention, there is provided a failure detection device for an intake control valve mechanism of an engine, which determines a failure state of an intake control valve for each cylinder of an engine having a plurality of cylinders each having an intake control valve. is there. For this, as described in claim 3, for example, the failure state is determined for each cylinder based on the crank angle of the engine detected by a crank angle sensor or the like.

That is, the stroke state of each cylinder can be recognized by detecting the crank angle, and the failure determination unit detects the opening / closing operation of each intake control valve of each cylinder based on the detected crank angle. Then, the failure can be judged.

Further, according to the failure detecting device for the intake control valve mechanism of the engine according to the fourth aspect, which of the plurality of intake control valves is in a failed state can be externally displayed by the display means. A person who carries out repairs can quickly and easily recognize the intake control valve in a failed state.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic overall configuration diagram of an engine device to which a failure diagnosis device according to the present invention is applied. As shown in the figure, the engine body 1 is provided with a crank angle sensor 20 for detecting the engine speed, and the engine is provided with an intake passage 2 upstream and an exhaust passage 3 downstream thereof. An air flow meter 18 for detecting the intake air amount Q is provided on the upstream side of the intake passage 2, a throttle valve 14 is provided on the downstream side thereof, and a throttle opening sensor 16 for detecting the throttle opening is further provided. It has.

A pressure sensor 4 for detecting the intake pressure in the intake passage 2 is provided on the downstream side of the throttle valve 14, and the interior of the intake passage is divided into two passages by a partition wall 5 on the downstream side. On the other hand, a tumble control valve that is an intake control valve (hereinafter simply referred to as "TCV")
6 and 6 are provided for each cylinder. These TCV6,
Reference numeral 6 is connected to actuators 8 and 8 via a link or the like, and is normally opened by an urging means such as a spring, and a negative pressure is supplied to the actuators 8 and 8 to perform a closing operation. . This negative pressure is supplied by the negative pressure introducing passage 9 whose one end is open-connected to the intake passage 2,
The supply or stop is controlled by turning on / off the solenoid valve 10 which is an opening / closing valve provided in the middle of the negative pressure introducing passage 9.

An electronic control unit (hereinafter referred to as an ECU) 22 for controlling the solenoid valve 10 and receiving detection signals from each sensor is provided. This E
The CU 22 includes a CPU as a main arithmetic unit, a ROM in which a control program and preset fixed data are stored,
A RAM in which data after processing signals from each sensor or data processed by the CPU is stored, an input interface for inputting signals from each sensor, and a control signal from the CPU is output to the solenoid valve 10 or the like. The output interface is composed of microcomputers connected to each other via a bus line.

Next, FIG. 2 is a schematic block diagram showing the overall configuration of the embodiment of the present invention applied to the engine device of FIG.

As shown in the figure, an engine operating state detecting means 30 is provided as a structure for determining whether or not the engine operating state is in a steady state. The ECU 22 receives a signal from the engine operating state detecting means 30. A steady state determination unit 32 that receives the signal is configured. As the engine operating state detecting means 30, in the present embodiment, the engine speed N
crank angle sensor 20 for detecting e, throttle opening θ
The throttle opening sensor 16 for detecting the intake air amount and the air flow meter 18 for detecting the intake air amount Q are used. And
Based on these detection data, the steady state determination unit 32
Determines whether the engine operating state is in a steady state.

The signal indicating the judgment of the steady state judging section 32 is
It is also output to the drive means control unit 34 also configured in the ECU 22. The drive means control unit 34 sends a control signal to the solenoid valve 10 that controls the supply of negative pressure to the actuator 8 according to the determination result of the steady state. The actuator 8 opens / closes the TCV 6 by turning on / off the solenoid valve 10. (The drive means control unit 34, the solenoid valve 10, and the actuator 8 constitute the opening / closing drive means.) On the other hand, the pressure detection signal in the intake passage 2 from the pressure sensor 4 which is the pressure detection means is the ECU 22. It is input to the failure determination unit 42 configured inside. The failure determination unit 42 determines whether or not there is a failure state based on the pressure difference in the intake passage 2 when the TCV 6 is opened / closed by the pressure detection signal of the pressure sensor 4. This determination basically determines that the opening / closing operation of the TCV 6 is normally performed when the pressure difference is equal to or larger than a predetermined value, and determines that the TCV 6 is out of order when the pressure difference is smaller than the predetermined value.

Then, a signal indicating this determination result is output from the failure determination section 42 to the display means 44, and the display means 44 externally displays whether or not the TCV 6 is normally opened / closed. The display means 44 is provided with a diagnostic function that is activated by short-circuiting a test terminal provided in the ECU 22 when the engine is inspected.
Codes are displayed by flashing engine lamps, those that can be read by a dedicated checker, or various formats such as lamps and liquid crystal displays installed on the instrument panel so that the driver can confirm while driving. It is a thing.

Next, the operation of failure detection according to this embodiment will be described with reference to FIG.

FIG. 3 shows an operation flow of failure detection of the intake control valve mechanism in the embodiment of the present invention.

First, step (hereinafter referred to as "S") 10
At 1, it is determined whether or not to execute the TCV6 failure diagnosis. Here, if the throttle opening θ is smaller than the predetermined value (Yes), the failure determination is performed after S102. In S102, the TCV 6 is controlled to be in the closed state as a precondition operation for the failure determination.

Next, in S103, S104, and S105, it is determined whether the engine operating state is a steady state. That is, in S103, the crank angle sensor 2
When the amount of change (| Ni-Ni- ₁ |) in the engine speed Ne detected by 0 for a predetermined time is less than or equal to the set value a (Yes), and in S104, the throttle opening sensor 1
The amount of change (| Thi-Thi- ₁ |) in the predetermined time of the throttle opening θ detected by 6 is less than or equal to the set value b (Yes), and the intake detected by the air flow meter 18 in S105. If the amount of change (| Qi-Qi- ₁ |) in the air amount Q within a predetermined time is less than or equal to the set value c (Yes), it is determined that the engine is in a steady state.

Therefore, S101 and S103 to S10
5, it is determined whether the engine operating state is in a steady state for detecting a failure. For example, S101
If the opening θ of the throttle valve 14 detected by the throttle opening sensor 16 is equal to or more than a predetermined value (N
In o), the failure detection in the present embodiment is canceled in S112, and this flow ends (END). That is, if the opening / closing state change operation of the intake control valve is performed when the opening of the throttle valve 14 is equal to or larger than a predetermined value, in other words, when the engine load is large, such as during acceleration, the torque change becomes large and the drivability deteriorates and the driver is injured. It causes discomfort. Therefore, when the opening of the throttle valve 14 is equal to or larger than the predetermined value, the failure detection is not performed.

When at least one change amount from S103 to S105 is equal to or larger than the set value (No), the failure detection is canceled in S112, and this flow is ended (END). That is, if the operating state of the engine fluctuates during failure determination, the failure of the intake control valve mechanism may be erroneously determined. The operation is stopped and the normal engine operating state is restored.

If it is determined from S103 to S105 that the engine operating state is the steady state (Yes),
An operation for detecting a failure is performed after S106.

In S106, the pressure state of the intake passage 2 when the TCV 6 is closed is stored. Here, the pressure Pc in the intake passage 2 is detected by the pressure sensor 4, and this pressure Pc is stored in the RAM in the ECU 22 as the pressure at the time of closing.

Then, in S107, the TCV 6 is controlled to the open state in order to detect the pressure of the intake passage 2 when the TCV 6 is opened. That is, when the supply of the negative pressure to the actuator 8 is stopped based on the control signal output from the drive means control section 34, the TCV 6 is opened by the biasing means.

Then, in S108, the pressure state of the intake passage 2 when the TCV 6 is opened is stored. Here, the pressure Po in the intake passage 2 is detected by the pressure sensor 4, and this pressure Po is stored in the RAM in the ECU 22 as the pressure at the time of opening. Then, in S109, the pressure difference between the open state and the closed state is determined. That is, it is determined whether or not the value obtained by subtracting the open pressure Po from the closed pressure Pc is larger than the reference value d. In other words, TCV
It is judged whether or not the opening / closing operation of 6 is surely performed. The determination of S109 is performed by the failure determination unit 42 described above.

FIG. 4 shows the criteria for this determination, T
The pressure fluctuation of the intake passage 2 at the time of opening / closing when the CV 6 performs the opening / closing operation is shown. As shown, TCV6
The pressure Pc when the valve is closed is larger than the pressure Po when the valve is open, and when the TCV6 is normally opening and closing, the pressure difference Δ between the pressure when the TCV6 is open and when the TCV6 is closed.
P (ΔP = Pc-Po) is greater than or equal to the reference value d. That is, the reference value d is set as the minimum value of the pressure difference ΔP that is considered to be the normal operation of the TCV 6.

Therefore, when the pressure difference ΔP during opening / closing of the TCV 6 is smaller than the reference value d, it is determined that the opening / closing operation of the TCV 6 is not being performed reliably. As described above, by detecting the pressure difference between the opening and closing of the TCV 6, it is determined whether the TCV 6 is normally performing the opening / closing operation. That is, when the pressure difference ΔP is equal to or larger than the reference value d in S109 (Yes), the failure determination unit 42 determines that no failure has occurred, and ends this flow (END).

On the other hand, if the pressure difference ΔP is less than or equal to the reference value d (No), the failure determination unit 42 determines in S110 that the failure has occurred. Then, in S111, external display is performed based on this determination. This external display is
The display means 44 receives the signal from the failure determination section 42.

FIG. 5 is a graph showing the pressure fluctuation in the intake passage 2 according to the ignition sequence when the intake control valve is opened / closed. It shows a case where the intake control valve of the two cylinders fails and is not performing the opening operation. As shown in FIG. Looking at the pressure fluctuations in the two cylinders, the pressure value in the open state shown by the solid line is close to the pressure value in the closed state shown by the chain line, that is, the pressure difference fluctuates with a smaller pressure difference than in the normal state. There is. From this, No. It can be determined that the two-cylinder TCV6 has failed and the opening operation is not normally performed. Here, the determination for each cylinder is made using a signal from the crank angle sensor 20. Crank angle sensor 20
In addition to the engine speed Ne (see FIG. 1), the crank angle is also detected for various controls such as ignition timing.

Therefore, since the stroke state of each cylinder can be recognized from this crank angle, it can be recognized which cylinder the pressure fluctuation in FIG. Then, based on this pressure fluctuation, the pressure difference ΔP for each cylinder is recognized, and when the value is equal to or less than the reference value d, the failure determination unit 42 determines that this is a failure, and the display means 44 causes each cylinder to determine. By displaying the failure detection result of, the failed TCV6 can be easily recognized from the plurality of TCV6.

Next, another embodiment of the present invention will be described with reference to the flowchart of FIG.

FIG. 6 shows in advance whether or not the engine is in the steady state and the state suitable for the failure detection operation of the present invention.
In the four stages up to 04, it is determined whether or not the engine operating state is in the steady state, and then the failure detection operation corresponding to the current operating state of the TCV is performed. First, the operation from S201 to S204 is performed by S1 shown in FIG.
01, S103 to S105 are almost the same, and it is determined whether the engine operating state is in a steady state in which failure detection can be performed. And S201
When it is determined that the engine operating state is the steady state in all of steps from S to S204 (Yes), the operation for failure detection is performed in S205 and thereafter. S2
When No is determined in any one of the steps 01 to S204, the failure determination is not performed, and the failure detection is canceled in S211.

In S205, the pressure state in the intake passage 2 is stored regardless of whether the TCV 6 is open or closed. Here, the pressure Pc in the intake passage 2 is detected by the pressure sensor 4.
Is detected, and this pressure Pc is stored in the RAM in the ECU 22 as the pressure in the intake passage 2 before the opening / closing state changing operation.

Then, in S206, the open / close state changing operation of the TCV 6 is performed. That is, the TCV 6 is changed to the closed state if it is currently open and to the open state if it is closed.

Then, in S207, the pressure state in the intake passage 2 after the opening / closing state changing operation of the TCV 6 is stored. Here, the pressure Po in the intake passage 2 is detected by the pressure sensor 4, and this pressure Po is R in the ECU 22.
It is stored in the AM as the pressure in the intake passage 2 after the opening / closing state changing operation.

Then, in S208, a determination operation is performed to determine whether or not the TCV 6 has been reliably opened and closed, that is, whether or not a failure has occurred. This S208
The determination is made by the failure determination unit 26, and the failure detection is performed by the same determination as S109 shown in FIG. 3 of the above-described embodiment. That is, when the absolute value of the pressure difference ΔP in the intake passage 2 before and after the opening / closing state changing operation of the TCV 6 is smaller than the reference value d, the opening / closing operation of the TCV 6 is not actually performed, and the intake passage 2 It is judged that the normal pressure change does not occur inside.

Therefore, in S208, the pressure difference ΔP
If the absolute value of is greater than or equal to the reference value d (Yes), the failure determination unit 42 determines that there is no particular failure, and ends this flow (end). On the other hand, if the absolute value of the pressure difference ΔP is less than the reference value d (No), the failure determination unit 42 determines in S209 that the TCV 6 of one of the cylinders has a failure.

Then, in S210, an external display is made based on this judgment.

[0046]

As described above, according to the failure detecting device for the intake control valve mechanism of the engine according to the present invention, the failure of the intake control valve can be detected without adding a new member and the structure is complicated. It is possible to carry out quickly and accurately without any trouble. Moreover, since the failure state can be displayed externally, the user can quickly recognize the failure state. Further, since it is possible to determine the failure of each cylinder of the engine, it is possible to quickly recognize the failure even when only one cylinder has a failure.

[Brief description of drawings]

FIG. 1 is a schematic overall configuration diagram of an engine device to which an embodiment of the present invention is applied.

FIG. 2 is a schematic block diagram showing an overall configuration of an embodiment of the present invention.

FIG. 3 is a flowchart showing an operation of detecting a failure of the intake control valve mechanism according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram showing pressure fluctuations in the intake passage when the intake control valve is opened / closed.

5 is a diagram showing the engine No. of the engine of FIG. FIG. 6 is an explanatory diagram showing pressure fluctuations in the intake passage at the time of opening / closing the intake control valve when the intake control valve of the two cylinders fails.

FIG. 6 is a flowchart showing an operation of failure detection according to another embodiment of the present invention.

[Explanation of symbols]

 1 Engine Main Body 4 Pressure Sensor 6 Intake Control Valve (TCV) 8 Actuator 9 Negative Pressure Introduction Passage 10 Solenoid Valve 14 Throttle Valve 16 Throttle Opening Sensor 18 Air Flow Meter 20 Crank Angle Sensor 22 ECU (Electronic Control Unit)

Claims (4)

[Claims] 1. An intake control valve which is provided in an intake passage of an engine and which opens and closes a part of the intake passage to generate a forced gas flow in a combustion chamber, and an opening and closing of the intake control valve. In the failure detection device for the intake control valve mechanism of the engine, which has an opening / closing drive means for controlling according to the operating state, an engine operating state detecting means for determining whether or not the operating state of the engine is in a steady state, A drive means control unit that causes the intake control valve to perform an open / closed state changing operation for failure determination by the drive means when the engine operating state detection means determines that the engine operating state is in a steady state; Pressure detecting means for detecting the pressure in the intake passage at the time of opening / closing by the opening / closing state changing operation of the intake control valve for the failure determination, and the pressure detected by the pressure detecting means. If the pressure difference at the time of opening / closing is not less than a predetermined value, it is judged as a normal state, and if it is smaller than the predetermined value, it is judged as a failure state, and whether or not there is a failure state based on the judgment of the failure determination section. A device for detecting a failure of an intake control valve mechanism of an engine, comprising: 2. The engine according to claim 1, wherein the engine has a plurality of cylinders each having an intake control valve, and the failure determination unit determines a failure state of the intake control valve for each cylinder. A failure detection device for the intake control valve mechanism of the engine described. 3. The method according to claim 2, wherein the determination of the failure state of the intake control valve for each cylinder is performed based on the crank angle of the engine detected by the engine operating state detection means. Detection device for intake control valve mechanism of engine. 4. The failure diagnosis device for an intake control valve of an engine according to claim 2, wherein the external display of the failure state by the display means is displayed for each cylinder.