JP4529856B2 - Valve control device - Google Patents

Description

  The present invention relates to a valve control device (valve control device) arranged in a gas flow path through which gas sucked and exhausted from an engine like an EGR valve flows.

  Conventionally, in an EGR valve such as an EGR valve, a valve disposed in a gas flow path through which gas to be sucked and exhausted flows, deposits such as oil mist and black smoke accumulate, and the gas flow rate There are problems such as shortage of gas, gas leakage when fully closed, and slow valve operation. Therefore, the calculation method of various command values in the gas flow rate control is changed according to the control amount corresponding to the deposit accumulation amount (see, for example, Patent Document 1), or the deposited deposit is removed by rotating the valve body. (For example, refer to Patent Documents 2 and 3).

  In recent years, butterfly valves that vary the effective opening area of the gas flow path by rotating in the gas flow path have been widely used in the valves as described above. In the valve control device using this butterfly valve, as shown in Patent Documents 2 and 3, deposits attached to the outer periphery of the valve body are removed by rotating the butterfly valve in a range straddling the fully closed position.

  However, this removal operation is generally performed when there is no hindrance to the operation of the engine, for example, when the engine sound is low, such as immediately after the ignition is turned on or off, so that it can be heard by the passenger and cause discomfort. For this reason, it is preferable to minimize the deposit removal operation as much as possible.

By the way, the deposit removal operation and the change of the calculation method in the gas flow rate control method directly monitor or indirectly calculate some index corresponding to the deposit accumulation amount and set a threshold for these indexes. And is executed when the value of the index exceeds the threshold value. For this reason, in order to minimize the deposit removal operation as described above, it is necessary to appropriately set the threshold value.
Japanese Patent No. 3185538 JP 2001-173464 A JP 2003-314377 A

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to more appropriately set a threshold value serving as a guideline for executing a deposit removal operation or the like in a valve control device.

[Means of Claim 1]
The valve control device according to claim 1 is disposed in a gas flow path through which gas sucked and exhausted from the engine flows, and resists the rotational resistance force by a driving force applied from a predetermined actuator. The butterfly valve that rotates and changes the effective opening area of the gas flow path, and the rotation range of the butterfly valve are divided into a plurality, and the rotation resistance index value corresponding to the rotation resistance is divided A threshold value is set for each rotation range and stored in advance, and when the butterfly valve is actually driven, a rotation resistance index value is detected corresponding to the rotation range divided into a plurality of ranges, and the detected value and corresponding And a valve abnormality determining means for determining whether or not the rotation of the butterfly valve is slow by comparing with a threshold value of the rotation range to be performed.

  In the butterfly valve, a rotational resistance force due to sliding friction on the bearing and the outer periphery of the valve body acts in a direction opposite to the rotational direction. Since this turning resistance force varies depending on the deposit amount, the turning resistance index value corresponding to the turning resistance force can be an index of the deposit amount. Therefore, a threshold value is set for the rotation resistance index value, and the rotation resistance index value is compared with the threshold value to determine whether or not the butterfly valve is rotating slowly. Therefore, it can be determined whether or not the butterfly valve is difficult to rotate. The rotation resistance index value can be considered as a variable having some correlation with the rotation resistance.

  As described above, the sliding friction acting on the butterfly valve can be mainly divided into the shaft periphery friction in the bearing and the valve periphery friction in the valve body outer periphery. Here, the closer the rotation position of the butterfly valve is to the fully closed position, the larger the contact area between the outer periphery of the valve body and the flow path wall side seat portion. The closer you get, the stronger you will be. For this reason, the rotational resistance index value also varies according to the rotational position so as to correspond to the correlation between the friction around the valve and the rotational position.

  Therefore, as described above, if the rotation range of the butterfly valve is divided into a plurality of ranges and a threshold value is set for each of the divided rotation ranges, the threshold value is set according to the rotation resistance index value in each rotation range. Can be set. For this reason, it is possible to set a more appropriate threshold value as compared with the conventional case where the threshold value is set uniformly regardless of the rotation position.

[Means of claim 2]
According to a second aspect of the present invention, the valve control device is disposed in a gas flow path through which gas sucked and exhausted from the engine flows, and resists rotational resistance by a driving force applied from a predetermined actuator. The butterfly valve that rotates and changes the effective opening area of the gas flow path, and the rotation resistance equivalent to the rotation resistance force in a part of the rotation range including the fully closed position within the rotation range of the butterfly valve A threshold value is set for the force index value and stored in advance, and when the butterfly valve is actually driven, the rotation resistance index value is detected corresponding to the rotation range, and the detected value is compared with the threshold value. By doing so, it is provided with the valve abnormality determination means which determines whether rotation of a butterfly valve is slow.

  As described above, the friction around the valve increases as the rotation position of the butterfly valve is closer to the fully closed position, and rapidly increases in the vicinity of the fully closed position. Therefore, a threshold value for the rotation resistance index value is set only in a part of the rotation range including the fully closed position within the rotation range of the butterfly valve, and the rotation resistance index value is compared with the threshold value. However, it can be used as a guideline for performing a deposit removal operation or the like. As a result, the threshold value can be set considering only a part of the rotation range including the fully closed position, so that a more appropriate threshold value can be set compared with the conventional case where the threshold value is set uniformly regardless of the rotation position. Can be set.

[Means of claim 3]
The valve abnormality determination means of the valve control device according to claim 3 corrects the threshold based on a valve temperature equivalent amount corresponding to the temperature of the butterfly valve, and compares the rotation resistance index value with the corrected threshold value. Thus, it is determined whether or not the rotation of the butterfly valve is slow.
The influence of the deposit on the rotational resistance varies depending on the temperature of the deposit. Therefore, the rotational resistance is affected not only by the amount of deposits but also by the temperature of the deposits. Therefore, by correcting the threshold value based on the valve temperature equivalent amount, the threshold value can be changed to an appropriate size according to the temperature of the deposit. As a result, when determining whether or not the rotation of the butterfly valve is slow, the influence of the temperature of the deposit on the rotation resistance can be removed. The valve temperature equivalent amount is a variable having some correlation with the temperature of the deposit itself, such as the temperature of the butterfly valve, that is, the temperature of the deposit itself, the temperature of the gas, and the temperature of the engine coolant.

[Means of claim 4]
The valve abnormality determination means of the valve control device according to claim 4 corrects the rotational resistance index value based on a valve temperature equivalent amount corresponding to the temperature of the butterfly valve, and corrects the rotational resistance index value and the threshold value after correction. To determine whether or not the rotation of the butterfly valve is slow.
This means removes the influence of the deposit temperature on the rotational resistance by correcting the rotational resistance index value.

[Means of claim 5]
The predetermined actuator of the valve control device according to claim 5 is an electric actuator that receives a power supply to generate a driving force, and the valve abnormality determination means determines a power supply equivalent amount corresponding to the power supply amount to the actuator as a rotational resistance. Used as force index value.
This means uses a predetermined actuator as an electric actuator. In this case, since the driving force for overcoming the rotational resistance force can be obtained by supplying power to the actuator, the power supply amount can be considered as a variable having some correlation with the rotational resistance force, that is, the rotational resistance index value. it can. Therefore, if the power supply equivalent amount corresponding to the power supply amount is used as the rotation resistance index value, a threshold is set for the power supply equivalent amount, and the power supply equivalent amount is compared with the threshold value, it is extremely effective. It can be determined whether or not the rotation of the butterfly valve is slow.

[Means of claim 6]
The valve abnormality determining means of the valve control device according to claim 6 estimates the rotational resistance index value based on the engine operation history.
The deposit discharge flow rate varies depending on the engine operation history such as the fuel injection amount and the engine speed. Therefore, the deposit accumulation amount can be estimated using the fuel injection amount, the engine speed, and the like. Therefore, even if the rotational resistance index value having a large correlation with the deposit amount is estimated based on the operation history of the engine, the rotational resistance index value can be calculated with high accuracy.

  The valve control device of the best mode 1 is disposed in a gas flow path through which gas sucked and exhausted from an engine flows, and resists rotational resistance by a driving force applied from a predetermined actuator. The butterfly valve that rotates and changes the effective opening area of the gas flow path, and the rotation range of the butterfly valve are divided into a plurality of parts, and the rotation resistance index value corresponding to the rotation resistance force is divided. A threshold value is set for each moving range and stored in advance, and when the butterfly valve is actually driven, a turning resistance index value is detected corresponding to the turning range divided into a plurality, and the detected value corresponds to the detected value. A valve abnormality determination unit that determines whether or not the rotation of the butterfly valve is slow by comparing with a threshold value of the rotation range.

Further, the valve abnormality determination means corrects the threshold value based on the valve temperature equivalent amount corresponding to the temperature of the butterfly valve, and compares the rotation resistance index value with the corrected threshold value, so that the rotation of the butterfly valve Determine if you are slow.
Further, the predetermined actuator is an electric actuator that receives a power supply to generate a driving force, and the valve abnormality determination unit uses a power supply equivalent amount corresponding to a power supply amount to the actuator as a rotation resistance index value.

  The valve abnormality determination means of the valve control device of the best mode 2 estimates the rotational resistance index value based on the engine operation history.

[Configuration of Example 1]
A configuration of the valve control device 1 according to the first embodiment will be described with reference to FIGS. 1 and 2.
The valve control device 1 is disposed, for example, in a flow path 2 (EGR flow path: hereinafter referred to as a gas flow path 2) for recirculating exhaust gas to the intake side of the engine, and the exhaust gas recirculation amount. It drives and controls the EGR valve that adjusts.

  As shown in FIG. 1, the valve control device 1 is disposed in the gas flow path 2, and rotates the butterfly valve 3 that changes the effective opening area of the gas flow path 2 by rotating, and the butterfly valve 3 has a driving force. The actuator 4 is provided and rotated, and the control means 5 for controlling the operation of the actuator 4 is provided.

  The butterfly valve 3 includes a rotating shaft 6 to which a driving force is applied from an actuator 4 via a link mechanism (not shown), and a valve body 7 formed in a symmetric disk shape having the rotating shaft 6 as a central axis. Have The butterfly valve 3 is rotated against the rotation resistance force by the driving force applied from the actuator 4 to vary the effective opening area of the gas flow path 2. That is, the butterfly valve 3 rotates against the rotation resistance force by the driving force applied from the actuator 4 and varies its valve opening. Further, the turning resistance force is generated by the sliding friction on the bearing of the turning shaft 6 or the outer periphery of the valve body 7, and the strength varies depending on the amount of deposit 8 and the like. Here, the deposit 8 is a deposit of oil mist, black smoke or the like contained in the exhaust gas on the valve body 7 or the like.

  The actuator 4 is a known electric actuator such as an electric motor that receives power and generates a driving force.

  The control unit 5 includes a known drive circuit 9 that intermittently supplies power to the actuator 4 from a power source (not shown), and a microcomputer 10 that outputs a command signal to the drive circuit 9 and supplies power to the actuator 4 from the power source.

  The microcomputer 10 is a computer having a known structure including a CPU that performs control processing and arithmetic processing, a storage circuit such as a ROM and RAM that stores various programs and data, an input circuit, an output circuit, and the like. The microcomputer 10 calculates various command values for driving and controlling the actuator 4 in accordance with detection values input from various sensors such as the engine speed sensor 11, the accelerator opening sensor 12, and the water temperature sensor 13. At the same time, a command signal based on this command value is synthesized and output to the drive circuit 9.

  Further, the microcomputer 10 serves as a valve abnormality determination means for determining whether or not the butterfly valve 3 is difficult to rotate due to over-depositing of the deposit 8 or the like, that is, whether or not the butterfly valve 3 is rotating slowly. Function.

  The valve abnormality determination means divides the rotation range of the butterfly valve 3 into a plurality of ranges, and sets a threshold value for each of the divided rotation ranges with respect to the rotation resistance index value corresponding to the rotation resistance. Remember. Then, the valve abnormality determination means detects a rotation resistance index value corresponding to the rotation range divided into a plurality when the butterfly valve 3 is actually driven, and the detected value and the corresponding rotation range are detected. By comparing with the threshold value, it is determined whether or not the rotation of the butterfly valve 3 is slow. Here, the rotation resistance index value can be considered as a variable having a correlation with the rotation resistance, and can be an index of the deposit amount.

  The valve abnormality determining means according to the first embodiment is configured so that the total rotation range of the butterfly valve 3 is divided into two rotations, a rotation range I in the vicinity of the fully closed position and a rotation range II in the vicinity of the fully closed position as shown in FIG. Divide into moving ranges. Then, the valve abnormality determining means selects a power supply equivalent amount (specifically, a duty ratio described later) corresponding to the power supply amount to the actuator 4 as the rotation resistance index value, and the rotation range I with respect to the duty ratio. Threshold value CI in, and threshold value CII in rotation range II are set and stored.

  Here, the power supply equivalent amount is a variable having a correlation with the power supply amount to the actuator 4, and a process for calculating the command value of the duty ratio of the command signal output to the drive circuit 9 and the command value of this duty ratio. Can include various command values obtained by the above, for example, a command value for the energization amount, a command value for the valve opening, and the like. Note that the valve abnormality determination means of the first embodiment employs a duty ratio command value as the power supply equivalent amount as the rotational resistance index value.

  Further, the turning resistance force in the turning range I is greatly affected by sliding friction on both the bearing of the turning shaft 6 and the outer periphery of the valve body 7. The sliding friction on the outer periphery of the valve body 7 has a greater influence on the rotational resistance as the rotational position is closer to the fully closed position, and the rotational resistance increases rapidly toward the fully closed position. For this reason, in the rotation range I, the duty ratio increases rapidly as the rotation position approaches the fully closed position.

  Further, the rotational resistance force in the rotational range II is greatly influenced by the sliding friction of the bearing of the rotational shaft 6. Here, the sliding friction of the bearing of the rotation shaft 6 has a small variation according to the rotation position, and the influence on the rotation resistance is substantially constant over the entire rotation range. Therefore, in the rotation range II, the duty ratio gradually approaches a substantially constant value as the rotation position approaches the fully open position.

  Since the rotational resistance increases as the deposit accumulation amount increases, the duty ratio also increases due to the deposit 8 being deposited.

  Further, the valve abnormality determining means corrects the threshold values CI and CII based on the valve temperature equivalent amount corresponding to the temperature of the butterfly valve 3, and compares the duty ratio with the corrected threshold values CI and CII. It is determined whether or not the rotation of is slow.

  Here, the valve-equivalent amount is a variable having a correlation with the temperature of the deposit 8, and includes the temperature of the exhaust gas, the temperature of the engine cooling water, and the like in addition to the temperature of the butterfly valve 3 itself. Since the temperature of the exhaust gas and the temperature of the engine cooling water are often preliminarily provided with a detection sensor such as the water temperature sensor 13, the amount corresponding to the valve temperature without increasing the cost due to the new arrangement of the sensor. Can be adopted as.

  The threshold values CI and CII vary with a width as shown in FIG. 2, for example, by correction based on the valve temperature equivalent amount. Here, the rotational resistance has a correlation with the temperature of the deposit 8, and becomes weaker as the temperature of the deposit 8 is higher. That is, when the temperature of the deposit 8 is increased, the rotational resistance is weakened even if the deposit accumulation amount is large. Thus, for example, when the threshold values CI and CII are used as a guideline for determining whether or not to perform the deposit removal operation, it is necessary to correct the threshold value so as to decrease as the deposit temperature increases.

[Control Method of Example 1]
A control method by the valve control device 1 according to the first embodiment will be described with reference to a flowchart shown in FIG.
First, in step S1, the difference between the valve opening command value of the butterfly valve 3 and the actual valve opening, that is, the difference between the target rotation position and the actual rotation position (valve position deviation) is calculated. Next, in step S2, whether or not the valve position deviation is small enough to allow determination by the valve abnormality determination means, that is, whether or not the target rotation position and the actual rotation position are substantially the same. Make a decision.

  If it is determined that the target rotation position and the actual rotation position substantially coincide with each other (YES), the valve temperature equivalent amount is detected in step S3. If it is determined that the target rotation position and the actual rotation position do not substantially coincide (NO), the flow is terminated. Next, in step S4, it is determined whether the actual rotation position is included in the rotation ranges I and II, and the threshold value CI including the actual rotation position based on the valve temperature equivalent amount, CII is corrected (hereinafter, it is assumed that the actual rotation position is included in the rotation range I).

  Next, in step S5, the duty ratio command value as the rotational resistance index value is compared with the corrected threshold value CI. When the duty ratio command value is larger than the corrected threshold CI (YES), it is determined in step S6 that the rotation of the butterfly valve 3 is slow. If the duty ratio command value is smaller than the corrected threshold CI (NO), it is determined in step S7 that the rotation of the butterfly valve 3 is not slow.

[Effect of Example 1]
According to the valve control device 1 of the first embodiment, the microcomputer 10 divides the entire rotation range of the butterfly valve 3 into two rotation ranges I and II, and with respect to a duty ratio that is a rotation resistance index value. Threshold values CI and CII are set and stored for each of the rotation ranges I and II, and it is determined whether or not the rotation of the butterfly valve 3 is slow by comparing the duty ratio with the threshold values CI and CII. Functions as a valve abnormality determination means.
Thus, by setting the threshold values CI and CII for the duty ratio for each of the rotation ranges I and II, as compared with the conventional case where a single threshold value is set uniformly regardless of the rotation position, A more appropriate comparison can be made.

Further, the valve abnormality determining means corrects the threshold values CI and CII based on the valve temperature equivalent amount corresponding to the temperature of the butterfly valve 3, and compares the duty ratio with the corrected threshold values CI and CII. It is determined whether or not the rotation of is slow.
In this way, by correcting the threshold values CI and CII based on the valve temperature equivalent amount, the threshold values CI and CII can be changed to appropriate sizes according to the temperature of the deposit 8. As a result, in determining whether or not the rotation of the butterfly valve 3 is slow, the influence of the temperature of the deposit 8 on the rotation resistance can be removed.

The actuator 4 is an electric actuator that receives power supply to generate a driving force, and the valve abnormality determination means sets a duty ratio, which is one of the power supply equivalent amounts corresponding to the power supply amount to the actuator 4, to the rotational resistance force. Used as an index value.
Since the driving force for overcoming the rotational resistance force is obtained by supplying power to the actuator 4, the power supply amount can be considered as a variable having some correlation with the rotational resistance force, that is, the rotational resistance index value. Therefore, the duty ratio, which is one of the power supply equivalent amounts corresponding to the power supply amount, is used as the rotational resistance index value, and the threshold values CI and CII are set for the duty ratio, and the duty ratio and the threshold values CI and CII are set. If compared, it can be determined very effectively whether or not the rotation of the butterfly valve 3 is slow.

[Configuration of Example 2]
The valve abnormality determination means of the valve control device 1 according to the second embodiment estimates the rotational resistance index value based on the operation history of the engine. This estimation is performed by adding a deposit deposition equivalent amount corresponding to an increase in the rotational resistance force due to deposit deposition to the ideal value of the rotational resistance index value in an ideal state where the deposit accumulation amount is zero. Then, this deposit accumulation equivalent amount is calculated based on the engine operation history, for example, the history of the fuel injection amount (fuel injection amount) and the engine speed (engine speed).

  That is, since the deposit discharge flow rate has a correlation with the fuel injection amount and the engine rotational speed, the valve abnormality determination means stores this correlation as map data in advance and sets the fuel injection amount and the engine rotational speed as values. Accordingly, the deposit discharge flow rate is calculated. Then, as shown in FIG. 4, the valve abnormality determination means calculates an integrated value of the deposit discharge amount (deposit integrated amount) by integrating the deposit discharge flow rate with time, and deposit deposit equivalent amount based on this deposit integrated amount. Is calculated.

Here, as the value of the fuel injection amount, for example, a command value calculated in the fuel injection control or a calculated value using a detected value of the fuel pressure in the common rail can be used. Further, the value detected by the engine speed sensor can be used as the value of the engine speed.
Similarly to the first embodiment, the entire rotation range of the butterfly valve 3 is divided into two rotation ranges I and II, and thresholds CI and CII for the rotation resistance index value are set for each of the rotation ranges I and II. Is set.

  The rotation resistance index value used as an ideal value may be a variable based on a power supply equivalent amount such as a duty ratio, or may be a variable based on the rotation resistance itself calculated by an experiment, a numerical simulation, or the like.

[Control Method of Example 2]
A control method by the valve control device 1 according to the second embodiment will be described with reference to a flowchart shown in FIG.
First, in step S11, the fuel injection amount, the engine speed, the valve temperature equivalent amount, and the rotation position (valve opening) are taken in. In step S12, the deposit discharge flow rate, the fuel injection amount, and the engine speed are correlated. The deposit discharge flow rate is calculated using the map.

  Next, in step S13, the accumulated deposit amount is updated by adding the calculated value of the deposit discharge flow rate to the accumulated deposit amount calculated in the previous process. Next, in step S14, it is determined whether or not a deposit removal operation has been performed between the previous deposit accumulated amount update and the current deposit accumulated amount updated. If the deposit removal operation has been performed (YES), the deposit integrated amount is reset to zero in step S15, and then the process proceeds to step S16. If the deposit removal operation has not been performed (NO), step S15 Without proceeding to step S16.

  Next, in step S16, the deposit accumulation equivalent amount is calculated based on the accumulated deposit amount, and the turning resistance index value is calculated by adding the deposit accumulation equivalent amount to the ideal value of the turning resistance index value. . Next, in step S17, the threshold value CI in the rotation range I or II (hereinafter referred to as the rotation range I) including the acquired rotation position is corrected based on the valve temperature equivalent amount.

  Next, in step S18, the rotation resistance index value is compared with the corrected threshold CI. If the rotation resistance index value is larger than the corrected threshold CI (YES), it is determined in step S19 that the rotation of the butterfly valve 3 is slow. If the rotation resistance index value is smaller than the corrected threshold CI (NO), it is determined in step S20 that the rotation of the butterfly valve 3 is not slow.

[Effect of Example 2]
The valve abnormality determination unit according to the second embodiment estimates the rotational resistance index value based on the engine operation history such as the fuel injection amount and the engine speed.
The deposit accumulation amount varies according to the engine operation history such as the fuel injection amount and the engine speed. Therefore, even if the rotation resistance index value having a large correlation with the deposit accumulation amount is estimated based on the operation history of the engine, the rotation resistance index value can be calculated with high accuracy.

[Modification]
Although the valve control device 1 of this embodiment controls the drive of the EGR valve, it can also control the exhaust throttle valve, the throttle valve, and the like.
In addition, the rotation resistance index value of the present embodiment is obtained by adding the deposit equivalent amount to the power supply equivalent amount or the ideal value of the rotation resistance index value, but a negative pressure type actuator is adopted as the actuator 4. In this case, the negative pressure amount and a variable correlated with the negative pressure amount can be used as the rotational resistance index value. Further, when a hydraulic actuator is employed, the hydraulic pressure amount and a variable correlated with the hydraulic pressure amount can be used as the rotational resistance index value.
In this embodiment, the entire rotation range of the butterfly valve 3 is divided into two rotation ranges I and II. However, the butterfly valve 3 is divided into two or more rotation ranges so that the determination can be made more finely. Also good.

The valve abnormality determination means of the present embodiment sets the threshold value for the rotation resistance index value in the entire rotation range of the butterfly valve 3, but some of the rotation ranges of the butterfly valve 3 including the fully closed position are included. A threshold value is set and stored in advance in the rotation range, and the butterfly valve 3 is compared with the detection value of the rotation resistance index value and the threshold value in the partial rotation range when the butterfly valve 3 is actually driven. It may be determined whether or not the rotation of the valve 3 is slow.
The sliding friction on the outer periphery of the valve body becomes stronger as the rotation position of the butterfly valve 3 is closer to the fully closed position, and becomes sharply stronger especially near the fully closed position. Therefore, a threshold value for the rotational resistance index value is set only in a part of the rotational range including the fully closed position within the rotational range of the butterfly valve 3, and the detected value and threshold value of the rotational resistance index value are set. Even if it compares, it can become a standard which performs deposit removal operation etc.
As a result, the threshold value can be set considering only a part of the rotation range including the fully closed position, so that a more appropriate threshold value can be set compared with the conventional case where the threshold value is set uniformly regardless of the rotation position. Can be set.

  The valve abnormality determination means of the present embodiment corrects the threshold values CI and CII based on the valve temperature equivalent amount, but corrects the rotational resistance index value, and the corrected rotational resistance index value and the threshold values CI and CII May be determined whether or not the rotation of the butterfly valve 3 is slow.

(A) is a block diagram of a valve | bulb control apparatus, (b) is AA sectional drawing of (a) (Example 1). (Example 1) which is a correlation diagram of the rotation position of a butterfly valve, and a rotation resistance index value. 5 is a flowchart illustrating a control method by the valve control device (Example 1). (A) is a time chart which shows an example of the log | history of fuel injection quantity and an engine speed, (b) is a time chart which shows transition of the deposit discharge flow rate and deposit integration amount computed based on the log | history of (a). There is (Example 2). It is a flowchart which shows the control method by a valve control apparatus (Example 2).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve control apparatus 2 Gas flow path 3 Butterfly valve 4 Actuator 10 Microcomputer (valve abnormality determination means)

Claims (6)

An effective opening of the gas flow path is disposed in the gas flow path through which the gas sucked and exhausted from the engine flows, and rotates against the rotational resistance force by a driving force applied from a predetermined actuator. A butterfly valve with variable area;
The rotation range of the butterfly valve is divided into a plurality of values, and the rotation resistance index value corresponding to the rotation resistance is set in advance for each divided rotation range, and stored in advance.
When the butterfly valve is actually driven, a rotation resistance index value is detected corresponding to the plurality of rotation ranges, and the detected value is compared with a threshold value of the corresponding rotation range. And a valve abnormality determining means for determining whether or not the rotation of the butterfly valve is slow. An effective opening of the gas flow path is disposed in the gas flow path through which the gas sucked and exhausted from the engine flows, and rotates against the rotational resistance force by a driving force applied from a predetermined actuator. A butterfly valve with variable area;
In a part of the rotation range including the fully closed position in the rotation range of the butterfly valve, a threshold is set for the rotation resistance index value corresponding to the rotation resistance, and stored in advance.
When the butterfly valve is actually driven, a rotation resistance index value corresponding to the rotation range is detected, and the rotation of the butterfly valve is slowed by comparing the detected value with the threshold value. A valve control device comprising valve abnormality determination means for determining whether or not. In the valve control device according to claim 1 or 2,
The valve abnormality determining means corrects the threshold based on a valve temperature equivalent amount corresponding to the temperature of the butterfly valve, and compares the rotational resistance index value with the corrected threshold value, thereby A valve control device for determining whether or not the rotation is slow. In the valve control device according to claim 1 or 2,
The valve abnormality determining means corrects the rotational resistance index value based on a valve temperature equivalent amount corresponding to the temperature of the butterfly valve, and compares the corrected rotational resistance index value with the threshold value. And determining whether or not the rotation of the butterfly valve is slow. In the valve control device according to claim 1 or 2,
The predetermined actuator is an electric actuator that receives electric power to generate a driving force,
The valve abnormality determining means uses a power supply equivalent amount corresponding to a power supply amount to the actuator as the rotation resistance index value. In the valve control device according to claim 1 or 2,
The valve abnormality determining means estimates the rotation resistance index value based on an operation history of the engine.

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