JPH1018919A - Abnormality discriminating method and device for solenoid valve for controlling pressure type actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and correctly discriminate the abnormality of a solenoid valve for controlling a pressure type actuator. SOLUTION: This device is provided with an operation condition detecting means 27 for detecting the operation condition of a pressure type actuator 19, a solenoid valve 12 for introducing atmospheric pressure, and a solenoid valve 14 for introducing negative pressure. At the time when the operation condition of the pressure type actuator 19 is confirmed by the operation condition detecting means 27, the control condition of one solenoid valve 14 is detected by a valve control condition detecting means 30, in accordance with the control state of the solenoid valve 14, it is judged whether the other solenoid valve 12 is abnormal or not by an abnormality judging means 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for determining an abnormality in a solenoid valve for controlling a pressure type actuator for driving a valve body of an exhaust gas recirculation control valve provided in an exhaust gas recirculation passage of an engine.

[0002]

2. Description of the Related Art Conventionally, as shown in, for example, Japanese Patent Application Laid-Open No. 2-9937, an exhaust gas recirculation passage that opens and closes an exhaust gas recirculation passage that connects an exhaust passage and an intake air passage of an engine is provided. In the engine that is installed,
The exhaust gas recirculation control valve is temporarily opened and closed during the deceleration operation of the engine to detect whether or not the fluctuation of the intake air pressure before and after the opening and closing is within a set range. A failure diagnosis is performed to determine whether or not a solenoid valve for controlling a pressure type actuator for driving a valve body of a valve is normally operating.

That is, in the failure diagnosis, the opening degree of the exhaust gas recirculation control valve is adjusted by controlling the supply pressure to the pressure type actuator by a solenoid valve for introducing atmospheric pressure and a solenoid valve for introducing negative pressure. In the exhaust gas recirculation control device configured to control the exhaust gas recirculation amount, the intake air pressure that fluctuates when the exhaust gas recirculation control valve is opened and closed is detected, and the solenoid valve operates based on the detected value. It is configured to determine whether the exhaust gas recirculation control is operating normally and is properly executed, and when the above detected value is not within the set range, it is configured to diagnose that the exhaust gas recirculation control valve is out of order. There is.

[0004]

According to the failure diagnosis method having the above-described structure, a failure in which the exhaust gas recirculation control valve does not operate at all, for example, such as a fixation of the valve body of the exhaust gas recirculation control valve or an open fixation of the negative pressure solenoid. When a failure occurs, it can be determined. Further, even when the solenoid valve for introducing atmospheric pressure is stuck in the open state, it is theoretically possible to determine the abnormality based on the intake pressure that changes according to the operating state of the exhaust gas recirculation control valve.

[0005] However, the passage for atmospheric pressure introduction connected to the solenoid valve for introducing atmospheric pressure usually has a small hole diameter, so that even if the solenoid valve for introducing atmospheric pressure is stuck in the open state, the negative pressure is negative. When the solenoid valve for pressure introduction is opened and a negative pressure is introduced into the negative pressure chamber of the pressure type actuator, the exhaust gas recirculation control valve is activated, so that it is possible to accurately determine the abnormality of the solenoid valve. There is a problem that you cannot do it.

In view of such circumstances, the present invention provides a method and apparatus for determining an abnormality in a solenoid valve for controlling a pressure type actuator, which can easily and accurately determine an abnormality in the solenoid valve for controlling a pressure type actuator. Things.

[0007]

The invention according to claim 1 is
An operating state detecting means for detecting an operating state of the pressure type actuator, a solenoid valve for introducing atmospheric pressure, and a solenoid valve for introducing negative pressure, wherein the two solenoid valves are operated in accordance with a detection signal of the operating state detecting means. One of the solenoid valves is configured to adjust the supply pressure to the pressure type actuator by controlling each of the above, and at the time when the pressure type actuator is confirmed to be in the operation state by the operation state detecting means. Is detected, and it is determined whether or not the other solenoid valve is abnormal according to the control state of the solenoid valve.

According to the above arrangement, when the pressure-type actuator is operated, one of the control states of the atmospheric pressure introducing solenoid valve or the negative pressure introducing solenoid valve for controlling the supply pressure to the pressure type actuator is detected. When it is confirmed that the control state is a state that cannot occur at normal times, the other solenoid valve is determined to be abnormal.

According to a second aspect of the present invention, in the method for determining an abnormality of a solenoid valve for controlling a pressure type actuator according to the first aspect, the solenoid valve for introducing atmospheric pressure and the solenoid valve for introducing negative pressure are duty controlled. Detecting whether one of the duty ratios is equal to or greater than a preset reference value and, when it is confirmed that the duty ratio is equal to or greater than the reference value, determines that the other solenoid valve is abnormal. .

According to the above configuration, when the pressure-type actuator is operated, the output is provided to control one of the atmospheric pressure introduction solenoid valve and the negative pressure introduction solenoid valve for controlling the supply pressure to the pressure-type actuator. When the duty ratio of the control signal is detected, and it is determined that the duty ratio is equal to or greater than a preset reference value, and it is confirmed that the control state of the solenoid valve is in a state that cannot occur at normal times, It is determined that the other solenoid valve is abnormal.

According to a third aspect of the present invention, in the method for determining an abnormality of the solenoid valve for controlling a pressure type actuator according to the first or second aspect, the solenoid for introducing atmospheric pressure is selected according to the control state of the solenoid valve for introducing negative pressure. It is for determining whether or not the valve is abnormal.

According to the above configuration, when the pressure-type actuator is operated, the control state of the negative pressure introducing solenoid valve is detected, and if it is confirmed that this control state cannot be performed in a normal state, a large error occurs. The solenoid valve for introducing the atmospheric pressure is determined to be abnormal.

The invention according to claim 4 is the above-mentioned claims 1 to 3.
The method according to any one of claims 1 to 3, wherein the pressure control is performed to control a supply pressure to a pressure-type actuator that drives a valve element of an exhaust gas recirculation control valve provided in an exhaust gas recirculation passage of the engine. It is for determining whether or not one of the introduction solenoid valve and the negative pressure introduction solenoid valve is abnormal.

According to the above construction, when the pressure type actuator for driving the valve element of the exhaust gas recirculation control valve provided in the exhaust gas recirculation passage of the engine is operated, the atmospheric pressure introduction for controlling the supply pressure to the pressure type actuator is controlled. If the control state of one of the solenoid valve or the solenoid valve for introducing negative pressure is detected and it is confirmed that this control state cannot occur under normal conditions, it is determined that the other solenoid valve is abnormal. Will be done.

According to a fifth aspect of the present invention, there is provided an operating state detecting means for detecting an operating state of a pressure type actuator, a solenoid valve for introducing atmospheric pressure, and a solenoid valve for introducing negative pressure. A valve control state detecting means for detecting the control state of one solenoid valve, wherein the supply pressure to the pressure type actuator is adjusted by controlling both solenoid valves in accordance with the detection signal of the means. When it is confirmed that the pressure type actuator is in the operating state according to the detection signal of the operating state detecting means, whether the other solenoid valve is abnormal according to the detecting signal of the valve control state detecting means. An abnormality determining means for determining whether or not it is provided.

According to the above construction, when the pressure type actuator is operated, one of the atmospheric pressure introducing solenoid valve and the negative pressure introducing solenoid valve for controlling the supply pressure to the pressure type actuator detects the valve control state. When the abnormality determination means confirms that this control state cannot occur under normal conditions, the other solenoid valve is determined to be abnormal.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic configuration of an engine equipped with an abnormality determining device for a solenoid valve for controlling a pressure type actuator according to an embodiment of the present invention. This engine has an engine body 1, an intake passage 2, and an exhaust passage 3. The intake passage 2 is provided with an air cleaner 4, an air flow meter 5, a throttle valve 6, a surge tank 8 and a fuel injection valve 9 in this order from the upstream side.

An exhaust gas recirculation passage 10 communicating with the exhaust gas passage 3 is connected to a part of the intake passage 2, for example, the surge tank 8, and the exhaust gas recirculation passage 10 is connected to the exhaust gas recirculation control valve 1.
1 is provided. An air introduction passage 13 having a solenoid valve 12 for introducing atmospheric pressure is connected to the upstream side of the throttle valve 6, and a solenoid valve for introducing negative pressure is provided downstream of the throttle valve 6. A negative pressure introduction passage 15 having an air passage 14 is connected. The atmospheric pressure introduction passage 13 and the negative pressure introduction passage 15 are connected to the exhaust gas recirculation control valve 11 via a merge passage 16.

The exhaust gas recirculation control valve 11 has a housing 17 provided in the exhaust gas recirculation passage 10, as shown in FIG.
And a valve body 18 installed in the housing 17, and a pressure type actuator 19 for driving the valve body 18. The valve body 18 is configured to be driven by pressure according to the supply pressure of air supplied to the actuator 19.

The pressure type actuator 19 includes the valve body 1
And a negative pressure chamber 2 provided on both sides of the diaphragm 20 made of a fluorine-based rubber material or the like connected via a rod
1 and an atmospheric pressure chamber 22, a spring 23 disposed in the negative pressure chamber 21 for urging the valve element 18 in a valve closing direction, and a position sensor 25 for detecting the position of the valve element 18. The negative pressure chamber 21 is connected to the atmospheric pressure introducing passage 13 and the negative pressure introducing passage 15 via the confluence passage 16, respectively.

Then, the solenoid valve 12 for introducing the atmospheric pressure and the solenoid valve 14 for introducing the negative pressure are feedback-controlled in accordance with a duty signal output from the engine control unit (ECU) 26 described below, whereby the above The mixing ratio of the negative pressure introduced into the negative pressure chamber 21 and the atmospheric pressure is adjusted, and the valve body 18 of the exhaust gas recirculation control valve 11 is provided with the spring 23 according to the supply pressure introduced into the negative pressure chamber 21. It is driven over the range from the fully closed position to the fully open position against the force. The exhaust gas recirculation control valve is driven in such a manner that the opening degree of the valve element 18 is increased as the negative pressure acting on the negative pressure chamber 21 is increased. 11 is opened and closed to control the recirculation amount of the exhaust gas recirculated from the exhaust passage 3 to the intake passage 2.

The engine control unit 26 includes operating state detecting means 27 for detecting whether or not the pressure type actuator 19 is in an operating state according to a position detection signal of the valve element 18 output from the position sensor 25; The detection signal of the engine speed output from the rotation sensor 7 for detecting the engine speed, the detection signal of the throttle sensor 28 for detecting the opening of the throttle valve 6 and the detection signal of the intake air amount output from the air flow meter 5 Operating state determining means 29 for determining whether or not the engine is in a predetermined operating state, which will be described later, accordingly.

In the engine control unit 26, the operating state detecting means 27 and the operating state determining means 29 confirm that the pressure type actuator 19 is operating and the engine is in a predetermined operating state. At this point, the valve control state detecting means 30 for detecting the control state of the negative pressure introducing solenoid valve 14 and the atmospheric pressure introducing solenoid valve 12 according to the detection signal of the valve control state detecting means 30 An abnormality determining means 31 for determining whether or not an abnormality has occurred is provided.

That is, the abnormality determining means 31 determines whether the duty ratio of the control signal output for duty-controlling the solenoid valve 14 for introducing a negative pressure is greater than a reference value set in accordance with the atmospheric pressure. It is determined whether or not it is large, and when it is confirmed that the pressure is large, the duty control of the solenoid valve 14 for introducing a negative pressure, which normally cannot occur due to the failure of the solenoid valve 12 for introducing the atmospheric pressure, is executed. The display command signal indicating that an abnormality has occurred in the display means 32 is output.

The control operation executed by the abnormality discriminating apparatus having the above structure will be described with reference to the flowchart shown in FIG. When the above control operation starts, first, in step S
1, the abnormality determination timer is set to a predetermined diagnostic time C
In addition to setting to x, the operating time of the solenoid valve 14 for introducing the negative pressure, that is, the integration time Cv of the integration timer that integrates the duty ON time is reset, and an initial value is set.

Next, in step S2, it is determined whether or not the engine is in a predetermined operating state. In this step S2, based on the engine speed detected by the speed sensor 7, the throttle opening detected by the throttle sensor 28, the intake air amount detected by the air flow meter 5, and the engine speed. The calculated intake charging efficiency is in a specific operation state within a predetermined range, and the change rate of the engine speed, the change rate of the throttle opening, the change rate of the intake charging efficiency, and the position When it is confirmed that the displacement rate of the position of the valve element 18 detected by the sensor 25, that is, the rate of change of the opening degree of the exhaust gas recirculation control valve 11, is in a steady operation state in which each is equal to or less than a predetermined value, the engine Are determined to be in a predetermined operating state.

Next, in step S3, the integrated time Cx of the abnormality determination timer is decremented, and in step S4, the operating time of the solenoid valve 14 for introducing negative pressure is added to the integrated time Cv of the integration timer. To do. In step S5, it is determined whether the diagnosis time Cx of the abnormality determination timer has become 0, that is, whether the abnormality determination timer has timed out.

If the determination in step S5 is NO, the process returns to step S2 and repeats the above flow. Then, if it is determined YES in the above step S5 and it is confirmed that the timer for abnormality determination has timed out, in step S6, the reference time S corresponding to the atmospheric pressure is obtained from the reference time setting table (not shown). After the reading, in step S7, it is determined whether or not the integration time Cv of the integration timer is equal to or longer than the reference time S.
The above reference time setting table indicates that the exhaust gas recirculation control valve 11 is attributable to the fact that the atmospheric pressure at high altitude is lower than that at low altitude.
Since the negative pressure required to open the valve element 18 changes, the reference time S for abnormality determination is set to change accordingly.

The result of the determination in step S7 is YES, and the ratio of the integrated time Cv to the predetermined diagnostic time Cx, that is, the duty ratio, which is the ratio of the operating time of the solenoid valve 14 per unit time, is set to a predetermined reference value. When it is confirmed that the value is equal to or more than the value, in step S8, a display signal indicating that the atmospheric pressure introducing solenoid valve 12 that controls the pressure type actuator 19 is abnormal is output, and in step S9, The abnormal data is stored.

When the operating state detecting means 27 confirms that the pressure type actuator 19 is in the operating state, the control state of the solenoid valve 12 for introducing the negative pressure is detected, and according to the control state. Since it is configured to determine whether the atmospheric pressure introducing solenoid valve 12 is abnormal or not, regardless of the operating state of the exhaust gas recirculation control valve 11 driven by the pressure type actuator 19, the atmospheric introducing solenoid is used. It is possible to accurately determine whether the valve 14 is out of order.

For example, when a failure occurs in which the solenoid valve 12 for introducing the atmospheric pressure is stuck in the open state, based on the value detected by the position sensor 25 and a target value corresponding to the operating state of the engine. In order to execute the feedback control for opening and closing the exhaust gas recirculation control valve 11, the solenoid valve 14 for introducing the negative pressure is opened to introduce the negative pressure into the negative pressure chamber 21 of the pressure type actuator 19, When the supply pressure to the negative pressure chamber 21 is controlled, the solenoid valve 14 for introducing the negative pressure is in a control state that cannot normally occur. Therefore, the solenoid valve 12 for introducing the atmosphere is controlled according to the control state. Abnormality can be determined.

That is, when the solenoid valve 12 for introducing atmospheric pressure is stuck in an open state because the hole diameter of the atmosphere introducing passage 13 connected to the merging passage 16 is small, the solenoid valve for introducing negative pressure is used. In the case where the negative pressure introduced into the negative pressure chamber 21 is adjusted to a predetermined value by the pressure type actuator 19 by prolonging the opening time of 14, the operating state of the exhaust gas recirculation control valve 11 can be checked accurately. However, since the duty ON time of the solenoid valve 14 for introducing the negative pressure increases, it is possible to accurately determine the failure of the solenoid valve 12 for introducing the atmospheric pressure.

Further, in the above embodiment, it is confirmed by the operating state detecting means 27 that the pressure type actuator 19 is in the operating state, and the negative pressure is set only when the engine is in the specific operating state and the steady operating state. Since the abnormality of the solenoid valve 12 for introducing atmospheric pressure is determined based on the control state of the solenoid valve 14 for introduction, the special operation or the operation state of the engine in which the engine speed is in an extreme region significantly changes. There is an advantage that erroneous determination due to the above-described abnormality determination can be prevented during a transition or the like.

In the above embodiment, an example has been described in which it is determined whether or not the solenoid valve 12 for introducing atmospheric pressure is abnormal according to the control state of the solenoid valve 14 for introducing negative pressure. However, the control state of the solenoid valve 12 for introducing atmospheric pressure may be detected, and it may be determined whether or not the solenoid valve 14 for introducing negative pressure is abnormal according to the control state.

If the negative pressure is not introduced due to the opening and fixing of the solenoid valve 14 for introducing the negative pressure, or if the valve body 18 of the exhaust gas recirculation control valve 11 is stuck, the malfunction of the exhaust gas recirculation control valve 11 may occur. Since the determination can be made by detecting the state or by detecting the pressure change of the intake air in the intake passage 2, the abnormality determination by these methods and the abnormality determination according to the present invention may be used together. Good.

Further, in the above embodiment, the solenoid valve 12 for introducing the atmosphere and the solenoid valve 14 for introducing the negative pressure are duty-controlled, and the abnormality of the other is determined based on the duty ratio of the one. However, in the one in which the opening degrees of the solenoid valves 12 and 14 are linearly controlled, the other abnormality is determined based on the opening degree of one of the solenoid valves 12 and 14. You may.

Further, the abnormality determination method and apparatus according to the present invention are not limited to the solenoid valve for controlling the pressure type actuator for driving the exhaust gas recirculation control valve 11, but also the solenoid valve for introducing atmospheric pressure and the solenoid valve for introducing negative pressure. The present invention is applicable to those configured to adjust the supply pressure to the pressure-type actuator by controlling these solenoid valves, respectively.

[0038]

As described above, the present invention comprises the operating state detecting means for detecting the operating state of the pressure type actuator, the solenoid valve for introducing atmospheric pressure, and the solenoid valve for introducing negative pressure. When it is confirmed by the operating state detecting means that the pressure type actuator is in the operating state, the control state of one solenoid valve is detected, and the other solenoid valve is abnormal according to the control state of this solenoid valve. Since it is configured to determine whether or not the solenoid valve for introducing atmospheric pressure has a small hole diameter in the atmospheric pressure introducing passage connected to the solenoid valve for introducing atmospheric pressure, the solenoid valve for introducing atmospheric pressure is stuck in an open state. In the case where a solenoid valve for introducing atmospheric pressure is set based on the control state of the solenoid valve for introducing negative pressure, There is an advantage that abnormality can be easily and accurately determined.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an embodiment of an abnormality determining device for a solenoid valve for controlling a pressure type actuator according to the present invention.

FIG. 2 is an explanatory diagram showing a specific configuration of a pressure type actuator.

FIG. 3 is a flowchart showing a control operation of abnormality determination by the abnormality determination device.

[Explanation of symbols]

 11 Exhaust gas recirculation control valve 12 Solenoid valve for introducing atmospheric pressure 14 Solenoid valve for introducing negative pressure 19 Pressure actuator 27 Operating state detecting means 30 Valve control state detecting means 31 Abnormality determining means

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tamotsu Kamakura 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd.

Claims (5)

[Claims] 1. An operating state detecting means for detecting an operating state of a pressure type actuator, a solenoid valve for introducing atmospheric pressure, and a solenoid valve for introducing negative pressure are provided, which are responsive to a detection signal of the operating state detecting means. The control device is configured to adjust the supply pressure to the pressure type actuator by respectively controlling the solenoid valves, and when the pressure type actuator is confirmed to be in the operation state by the operation state detecting means. An abnormality determination of a solenoid valve for controlling a pressure type actuator, characterized by detecting the control state of one solenoid valve and determining whether the other solenoid valve is abnormal according to the control state of this solenoid valve Method. 2. A duty control of a solenoid valve for introducing atmospheric pressure and a solenoid valve for introducing negative pressure, and detecting whether one of the duty ratios is equal to or greater than a predetermined reference value, and detecting the reference value. The method for determining an abnormality of a solenoid valve for controlling a pressure type actuator according to claim 1, wherein when the above is confirmed, the other solenoid valve is determined to be abnormal. 3. The method according to claim 1, wherein it is determined whether or not the solenoid valve for introducing atmospheric pressure is abnormal according to the control state of the solenoid valve for introducing negative pressure.
A method for determining abnormality of the solenoid valve for controlling the pressure type actuator described. 4. A solenoid valve for introducing atmospheric pressure and a solenoid valve for introducing negative pressure for controlling a supply pressure to a pressure type actuator for driving a valve element of an exhaust gas recirculation control valve provided in an exhaust gas recirculation passage of an engine. The method according to claim 1, wherein it is determined whether one of them is abnormal.
3. A method for determining an abnormality of a solenoid valve for controlling a pressure-type actuator according to any one of 3. 5. An operating state detecting means for detecting an operating state of the pressure type actuator, a solenoid valve for introducing atmospheric pressure, and a solenoid valve for introducing negative pressure are provided, and the operating state detecting means responds to a detection signal of the operating state detecting means. A valve control state detecting means for detecting a control state of one of the solenoid valves, and a valve control state detecting means for detecting a control state of one of the solenoid valves. When it is confirmed that the pressure type actuator is in the operating state according to the detection signal of the means, an abnormality is determined to determine whether or not the other solenoid valve is abnormal according to the detection signal of the valve control state detecting means. An abnormality judging device for a solenoid valve for controlling a pressure type actuator, comprising a judging means.