JP2009197767A - Abnormality determination device for variable operating angle mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an abnormality determination device for a variable operating angle mechanism, detecting the abnormality of the variable operating angle mechanism of an internal combustion engine with a high degree of accuracy. <P>SOLUTION: This abnormality determination device for the variable operating angle mechanism includes the variable operating angle mechanism 12, a control shaft 14, and an actuator moving the control shaft 14. The variable operating angle mechanism 12 enlarges the operating angle of an intake valve 10 arranged in the cylinder of the internal combustion engine when the control shaft 14 is moved in the predetermined direction, and reduces the operating angle of the intake valve 10 when the control shaft 14 is moved in the direction opposite to the predetermined direction. A rotation sensor 26 detects rotation of the actuator. A position sensor 28 detects the position of the control shaft 14. An ECU 50 acquires a leaning value based on a relative relation between output of the rotation sensor 26 and output of the position sensor 28. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an abnormality determination device for a variable working angle mechanism.

  There is known a variable working angle mechanism that continuously varies the working angle and lift amount of an intake valve of an internal combustion engine. Japanese Unexamined Patent Application Publication No. 2007-170357 discloses the following valve gear for an engine. In this valve operating apparatus, the rotational operation of the motor is converted into the linear operation of the control shaft, and the valve lift amount is varied according to the linear operation of the control shaft. In this valve operating apparatus, the valve lift amount is recognized based on the rotational position of the motor detected by the rotation sensor. In this valve operating apparatus, when the power supply is momentarily interrupted, the rotation angle detected by the rotation sensor may disappear, and the current valve lift amount may be lost. In that case, the relationship between the valve lift amount and the valve timing becomes inappropriate, and there is a possibility that engine misfire or knocking may occur. In order to solve this problem, the valve operating apparatus is provided with a first contact and a second contact that are turned on / off according to the position of the control shaft (see FIGS. 3 and 4 of the publication). The first contact and the second contact are both turned on only in a region where neither the misfire region nor the knock region enters in the relationship between the valve lift amount and the valve timing. (Paragraph 0046 of the publication). When the rotation angle detected by the rotation sensor disappears due to a momentary power interruption, the control shaft is moved to a position where both the first contact and the second contact are in the on state. Knocking is prevented (paragraph 0050 of the publication).

JP 2007-170357 A JP 2000-282901 A JP 2006-250150 A

  In a variable working angle mechanism that recognizes the valve working angle by detecting the amount of rotation of the motor that moves the control shaft with a sensor, if the actual valve working angle does not match the command value of the ECU, emissions and the like deteriorate. There is a case. In recent OBD (On-Board Diagnostic) regulations, it is required that a vehicle can automatically diagnose an abnormality even if the abnormality only causes a slight deterioration in emission. For this reason, in the variable working angle mechanism, when an abnormality occurs that causes a difference (deviation) between the actual valve working angle and the control command value, it is required to accurately diagnose this. In order to make the diagnosis, it is conceivable to use a control shaft position detection sensor.

  However, the position of the control shaft detected by the position detection sensor is not always accurate. This is because there are dimensional errors of a member (for example, a head cover) to which the position detection sensor is attached, assembly errors of the position detection sensor, or variations in output characteristics of the sensor itself. For this reason, when performing abnormality diagnosis of the variable operating angle mechanism using the position detection sensor, it is difficult to accurately detect a slight deviation in the valve operating angle. That is, it is difficult to accurately detect an abnormality. On the other hand, there is a possibility that it is erroneously determined to be abnormal although it is normal.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an abnormality determination device for a variable working angle mechanism that can detect an abnormality of a variable working angle mechanism of an internal combustion engine with high accuracy. .

In order to achieve the above object, a first invention is an abnormality determination device for a variable working angle mechanism,
A control shaft and an actuator for moving the control shaft, and when the control shaft is moved in a predetermined direction, an operating angle of a valve provided in a cylinder of the internal combustion engine is expanded, and the control shaft is A variable working angle mechanism that reduces the working angle when moved in a direction opposite to a predetermined direction;
A rotation amount sensor for detecting the rotation amount of the actuator;
A position sensor for detecting the position of the control axis;
Learning means for acquiring a learning value based on a relative relationship between the output of the rotation amount sensor and the output of the position sensor;
It is characterized by providing.

The second invention is the first invention, wherein
The rotation amount sensor emits a continuous output according to the rotation amount of the actuator,
The position sensor emits an output when the control axis reaches a plurality of specific positions,
The learning value is a value obtained by learning an output value of the rotation amount sensor at a timing when an output of the position sensor is generated.

The third invention is the first or second invention, wherein
An abnormality determining means is provided for determining whether or not the variable working angle mechanism is abnormal based on the learning value, the output of the rotation amount sensor, and the output of the position sensor.

According to a fourth invention, in any one of the first to third inventions,
The learning means is characterized in that the learning value is acquired in association with the change direction of the operating angle.

According to a fifth invention, in any one of the first to fourth inventions,
When the learning means performs learning, the learning means is provided with a displacement speed reduction means for slowing the displacement speed of the control shaft as compared with the normal displacement speed.

The sixth invention is the fifth invention, wherein
The valve is an intake valve;
A throttle valve installed in the intake passage of the internal combustion engine;
Normally, the intake air amount is controlled mainly by changing the operating angle of the intake valve, and when the learning means performs learning, the intake air amount is mainly changed by changing the opening of the throttle valve. Intake air amount control means to control;
It is characterized by providing.

According to a seventh invention, in any one of the first to sixth inventions,
The learning means obtains a learning value when the working angle is actually changed in the enlargement direction and a learning value when the working angle is actually changed in the reduction direction.

Further, an eighth invention is any one of the first to seventh inventions,
Information on the hysteresis existing between the output of the position sensor emitted in the process of changing the working angle in the enlargement direction and the output of the position sensor issued in the process of changing the working angle in the reduction direction was stored. Comprising hysteresis storage means,
The learning means obtains a learning value by actually changing the working angle for any one direction of the working angle expansion direction and the working angle reduction direction, and for the direction opposite to the one direction, The learning value is calculated based on the learning value in one direction and the information stored in the hysteresis storage means.

The ninth invention is the eighth invention, wherein
The one direction is a working angle reduction direction.

According to a tenth invention, in any one of the first to ninth inventions,
The position sensor emits an output when the control axis reaches a plurality of specific positions,
The learning means performs learning for each of a plurality of outputs corresponding to the plurality of specific positions to acquire a learning value.

The eleventh aspect of the invention is the tenth aspect of the invention,
Output interval storage means for storing information relating to the plurality of output intervals;
The learning means obtains temporary learning values for other outputs based on a learning value for an output for which learning has been completed first among the plurality of outputs and information stored in the output interval storage means. It includes a means for calculating.

The twelfth invention is the eleventh invention, in which
When the abnormality determination means determines the presence or absence of an abnormality based on the temporary learning value, the apparatus includes a determination criterion relaxation means that relaxes a criterion for determining that there is no abnormality.

  According to the first invention, based on the relative relationship between the output of the rotation amount sensor that detects the rotation amount of the actuator for moving the control shaft of the variable working angle mechanism and the output of the position sensor that detects the position of the control shaft. Learning value can be acquired. The relationship between the output of the position sensor and the actual operating angle due to the influence of the design tolerance of the components of the variable working angle mechanism and the parts to which the position sensor is attached, the assembly tolerance of each part, or the installation tolerance of the sensor elements in the position sensor In this case, there are variations among individuals. According to the first aspect of the invention, the relative relationship between the output of the rotation amount sensor and the output of the position sensor can be learned, so that the above-described variation can be absorbed. For this reason, the abnormality determination of the variable working angle mechanism can be performed with high accuracy without erroneous determination. That is, it is possible to accurately detect whether or not the actual operating angle of the valve follows the operating angle command value. Therefore, it is possible to diagnose deterioration of emissions and the like with high accuracy.

  According to the second aspect of the present invention, it is possible to perform abnormality determination with high accuracy using the position sensor that outputs when the control axis reaches a plurality of specific positions. Since the position sensor as described above is inexpensive, the manufacturing cost can be reduced according to the second invention.

  According to the third aspect of the present invention, it is possible to determine the presence or absence of abnormality of the variable working angle mechanism with high accuracy based on the learning value, the output of the rotation amount sensor, and the output of the position sensor.

  According to the fourth invention, the learning value can be acquired in association with the direction of change of the operating angle. For this reason, even when a hysteresis occurs in the output of the position sensor in accordance with the displacement direction of the control shaft, the abnormality determination can be performed appropriately.

  According to the fifth aspect, at the time of execution of learning, the displacement speed of the control shaft can be made slower than the normal displacement speed. Thereby, since the error of the learning value due to the influence of the sampling period of the rotation amount sensor can be reduced, abnormality determination can be performed with higher accuracy.

  According to the sixth invention, at the time of learning execution, the intake air amount can be controlled mainly by changing the opening degree of the throttle valve instead of the intake air amount control by varying the operating angle of the intake valve. As a result, even when the displacement speed of the control shaft is made slower than the normal displacement speed when learning is performed, it is possible to reliably prevent the drivability from being affected.

  According to the seventh aspect, it is possible to acquire a learning value when the operating angle is actually changed in the enlargement direction and a learning value when the operating angle is actually changed in the reduction direction. For this reason, when hysteresis occurs in the output of the position sensor in accordance with the displacement direction of the control shaft, both the learning value in the operating angle expansion direction and the learning value in the operating angle reduction direction can be obtained with high accuracy.

  According to the eighth aspect of the present invention, the learning value is obtained by actually changing the working angle in any one of the working angle expanding direction and the working angle reducing direction, and the direction opposite to the one direction is obtained. The learning value can be calculated based on the learning value in the one direction and information on hysteresis stored in advance. Thereby, in the case where hysteresis occurs in the output of the position sensor in accordance with the displacement direction of the control shaft, learning can be completed early.

  According to the ninth aspect, in the operating angle expansion direction, it is not necessary to actually move the control axis for learning. The working angle expansion direction is a direction in which the amount of intake air is increased, and is required during acceleration. Therefore, when learning is performed by reducing the control shaft displacement speed, a time lag occurs in the increase of the intake air amount, which may affect the feeling of acceleration. On the other hand, according to the ninth aspect, learning about the operating angle expansion direction is not necessary, and thus such a concern can be eliminated.

  According to the tenth aspect, learning can be performed by executing learning for each of a plurality of outputs emitted by the position sensor when the control axis reaches a plurality of specific positions. For this reason, abnormality determination can be performed with higher accuracy.

  According to the eleventh aspect, by storing in advance information related to the intervals between a plurality of outputs from the position sensor, provisional learning values for other outputs can be obtained from learning values for the output for which learning has been completed first. Can be calculated. For this reason, if learning is completed for any one of the plurality of outputs emitted by the position sensor, the abnormality determination can be performed for the other outputs using the temporary learning values. For this reason, abnormality determination can be started at an early stage.

  According to the twelfth aspect, when the abnormality determination is performed based on the temporary learning value, the criterion for determining that there is no abnormality can be relaxed. The temporary learning value may include an error due to the influence of design tolerance. According to the twelfth aspect, even when such an error is included, it is possible to reliably prevent an erroneous determination from occurring.

Embodiment 1 FIG.
[Description of system configuration]
FIG. 1 is a diagram for explaining a system configuration according to the first embodiment of the present invention. As shown in FIG. 1, the system of this embodiment continuously varies the working angle (hereinafter also simply referred to as “working angle”) of an intake valve 10 of an internal combustion engine (hereinafter referred to as “engine”) (not shown). The variable working angle mechanism 12 is provided.

  The variable working angle mechanism 12 includes a control shaft 14 and a control shaft drive device 16 that moves the control shaft 14 straight in the axial direction. The control shaft drive device 16 includes a motor as an actuator and a motion conversion mechanism (for example, a helical cam) that converts the rotational motion of the motor into a straight motion. The control shaft 14 and the output shaft 16 </ b> A of the control shaft drive device 16 are connected via a fastening member 18.

  A roller arm 20 and a pair of swing cams 22 located on both sides of the roller arm 20 are provided in the middle of the control shaft 14. A cam of an intake cam shaft (not shown) is in contact with the roller of the roller arm 20. When the intake camshaft rotates, the roller arm 20 swings. The swing cam 22 swings together with the roller arm 20. A rocker arm 24 is disposed between the swing cam 22 and the intake valve 10. The swing cam 22 is in contact with a roller provided on the rocker arm 24. When the swing cam 22 swings, the rocker arm 24 swings and the rocker arm 24 presses the intake valve 10 to lift (open) the intake valve 10.

  Helical splines having spiral shapes in opposite directions are formed on the inner peripheral portions of the roller arm 20 and the swing cam 22. A slider gear (not shown) that meshes with the helical spline is installed inside the roller arm 20 and the swing cam 22. The slider gear moves in the axial direction together with the control shaft 14. When the control shaft 14 is moved in the axial direction, the relative angle between the roller arm 20 and the swing cam 22 changes due to the action of the helical spline and the slider gear. As a result, the lift amount and the operating angle of the intake valve 10 change as the swing range of the swing cam 22 changes as the intake camshaft rotates.

  In this manner, in the variable working angle mechanism 12, the working angle of the intake valve 10 is continuously reduced by moving the control shaft 14 in one direction (for example, the left direction in FIG. 1) by the control shaft driving device 16. The operating angle of the intake valve 10 can be continuously increased by moving the control shaft 14 in the opposite direction (for example, the right direction in FIG. 1). Note that the detailed structure of the variable working angle mechanism 12 is described in, for example, Japanese Patent Application Laid-Open No. 2001-263015, and is well known. Therefore, further description is omitted in this specification.

  A rotation amount sensor 26 for detecting the rotation amount of the motor of the control shaft driving device 16 is installed in the vicinity of the control shaft driving device 16. A position sensor 28 that detects the position of the control shaft 14 is installed in the vicinity of the control shaft 14. The position sensor 28 of the present embodiment is configured to detect the position of the target 30 provided on the control shaft 14 in a non-contact manner. The motor of the control shaft driving device 16, the rotation amount sensor 26, and the position sensor 28 are electrically connected to an ECU (Electronic Control Unit) 50, respectively. Further, the ECU 50 is electrically connected to a throttle valve 32 installed in the intake passage of the engine.

  FIG. 2 is a diagram showing the relationship between the actual operating angle of the intake valve 10 and the output value of the rotation amount sensor 26. The rotation amount sensor 26 emits a continuous (linear) output proportional to the rotation amount of the motor of the control shaft driving device 16. The change in the actual operating angle of the intake valve 10 is proportional to the rotation amount of the motor of the control shaft driving device 16. Therefore, as shown in FIG. 2, the output value of the rotation amount sensor 26 changes continuously (linearly) as the actual operating angle of the intake valve 10 changes. That is, the output value (voltage value) of the rotation amount sensor 26 and the value of the operating angle of the intake valve 10 correspond one-to-one. In the following description, the output value of the rotation amount sensor 26 represents the actual operating angle of the intake valve 10.

  In an engine provided with the variable working angle mechanism 12, the intake air amount can be controlled without depending on the throttle valve 32 by changing the working angle of the intake valve 10. In this case, the ECU 50 sets the target operating angle of the intake valve 10 in accordance with the operating state of the engine in order to control the intake air amount. Then, the ECU 50 grasps the actual operating angle of the intake valve 10 based on the output of the rotation amount sensor 26, and controls the control shaft drive device 16 so that the actual operating angle matches the target operating angle.

  FIG. 3 is a diagram showing the relationship between the actual operating angle of the intake valve 10 and the output value of the position sensor 28. The position sensor 28 intermittently generates a plurality of (three in the present embodiment) edge outputs according to the position of the target 30, that is, the position of the control shaft 14. Therefore, as shown in FIG. 3, the position sensor 28 generates three edge outputs as the actual operating angle of the intake valve 10 changes.

  The position sensor 28 generates an edge output when the target 30 that moves together with the control shaft 14 comes to a specific position. Therefore, the operating angle of the intake valve 10 when the position sensor 28 generates an edge output is determined. Therefore, in this embodiment, it is determined based on the relative relationship between the output of the rotation amount sensor 26 and the output of the position sensor 28 whether or not the control shaft 14 is moving according to the command value of the ECU 50. That is, the value of the operating angle at the position of the control shaft 14 (hereinafter referred to as “reference operating angle”) at which an edge output should be issued from the position sensor 28 when the variable operating angle mechanism 12 is normal is stored in the ECU 50 in advance. Keep it. Then, the operating angle when the edge output is generated is read from the rotation amount sensor 26 and compared with a reference operating angle stored in advance. When the deviation between the two is equal to or less than a predetermined determination value (this determination value is set in advance in consideration of detection error due to sensor measurement error, software processing error, etc.), the control shaft 14 It can be determined that the motor is operating normally according to the command value of the ECU 50. Therefore, in this case, it can be determined that the variable working angle mechanism 12 is normal. On the other hand, when the deviation is larger than the determination value, it can be determined that there is a difference (deviation) between the actual position of the control shaft 14 and the command value of the ECU 50. Therefore, in this case, it can be determined that an abnormality has occurred in the variable working angle mechanism 12.

  The value of the reference working angle can be calculated based on the design value of each component. However, in reality, the design tolerance of the parts of the variable working angle mechanism 12 and the parts to which the position sensor 28 is attached (for example, the cylinder head cover), the assembly tolerance of each part, the attachment tolerance of each sensor element in the position sensor 28, etc. Due to the influence, the working angle when the edge output is actually emitted from the position sensor 28 varies among individuals. For this reason, if the abnormality determination is performed using the uniform reference working angle obtained from the design value, there is a risk of erroneous determination.

  Therefore, in this embodiment, the reference working angle is obtained by learning. That is, when the variable working angle mechanism 12 is in a normal state, the control shaft 14 is actually moved to change the working angle, the edge output from the position sensor 28 is detected, and the action when the edge output is generated. The learned value of the reference working angle is obtained by reading the angle value. Abnormality determination is performed using a learning value of such a reference working angle (hereinafter, sometimes simply referred to as “learning value”), thereby absorbing variations among individuals due to various tolerances as described above. Therefore, it is possible to make a highly accurate abnormality determination.

  Hereinafter, the position sensor 28 will be described in more detail with reference to FIGS. 4 and 5. FIG. 4 is an enlarged view of the position sensor 28. The position sensor 28 includes three sensor elements 28A, 28B, and 28C such as Hall elements. FIG. 5 is a diagram showing in detail the output of the position sensor 28 when the target 30 moves as indicated by the arrow in FIG. The upper stage in FIG. 5 shows output waveforms of the sensor elements 28A and 28B with the sensor element 28C as a reference. By applying predetermined signal processing to these output waveforms, three edge outputs can be obtained as shown in the lower part of FIG.

  Each edge output is emitted when the target 30 comes to a specific position. For this reason, the movement amount of the control shaft 14 between each edge output is determined. Therefore, the working angle interval between the edge outputs is also determined. However, due to the influence of the tolerance of the installation positions of the sensor elements 28A, 28B, 28C, etc., there is an individual difference in the working angle interval between the edge outputs, so it does not exactly match the design value. Therefore, in this embodiment, learning is performed for each of the three edge outputs emitted from the position sensor 28, and a learning value for each edge output is acquired. As a result, it is possible to absorb variations in the operating angle interval between the edge outputs due to individual differences in the position sensor 28, so that the abnormality determination can be performed with higher accuracy.

  Such a position sensor 28 has a characteristic that hysteresis occurs in the output depending on the moving direction of the target 30. That is, the position where each edge output is emitted differs depending on whether the target 30 (control axis 14) moves from right to left in the figure or from left to right. FIG. 6 is a diagram showing temporal changes in the output of the rotation amount sensor 26 and the output of the position sensor 28 when the control shaft 14 is moved in both directions.

  The position sensor output indicated by the solid line in FIG. 6 is obtained when the rotation amount sensor value changes in the decreasing direction, that is, when the control shaft 14 moves in the direction in which the operating angle decreases. In this case, an edge output is generated when the rotation amount sensor value is a value indicated by a circle in FIG.

  On the other hand, the position sensor output indicated by the broken line in FIG. 6 corresponds to the case where the rotation amount sensor value changes in the increasing direction, that is, the control shaft 14 moves in the direction in which the operating angle increases. In this case, an edge output is generated when the rotation amount sensor value is a value indicated by x in FIG.

  Thus, the rotation amount sensor value (action) when the edge output is emitted from the position sensor 28 in the case where the working angle changes in the direction of reduction and the case where the action angle changes in the direction of enlargement. The corners are different. Therefore, in the present embodiment, when learning the rotation amount sensor value when the edge output is generated, the learning value is acquired for each change direction of the operating angle.

  By the way, the rotation amount sensor output is A / D converted at every predetermined sampling period and read into the ECU 50. For this reason, the value handled by the ECU 50 as the rotation amount sensor value when the edge output is generated does not exactly match the rotation amount sensor output at the moment when the edge output is generated. There is a timing difference between the two at the maximum by an AD conversion cycle (sampling cycle). For this reason, an error corresponding to the amount of change in the rotation amount sensor output during the AD conversion cycle can occur in the learning value at the maximum.

  In order to reduce the above error, the AD conversion cycle may be shortened, but there is a trade-off that the processing load of the ECU 50 increases. On the other hand, even if the AD conversion cycle is not shortened, if the moving speed of the control shaft 14 (the change speed of the working angle) is slowed, the amount of change in the rotation sensor output during one AD conversion cycle is also reduced. Since it becomes smaller, the error becomes smaller. Therefore, in the present embodiment, when learning the rotation amount sensor value when the edge output is generated, the moving speed of the control shaft 14, that is, the change speed of the working angle is made slower than the normal time. Thereby, learning accuracy can be improved.

  As described above, in this system, the intake air amount is normally controlled by changing the operating angle of the intake valve 10. For this reason, if the operating angle change speed is slowed down, the engine torque changing speed slows down, making it difficult to quickly generate the torque requested by the driver. That is, when the intake air amount is controlled by the change in the operation angle of the intake valve 10, if the operation angle change speed is slowed down, the control speed of the intake air amount is reduced, so that the torque response of the engine may be deteriorated. . Therefore, in the present embodiment, when the operating angle change speed is made slower than the normal time for learning the reference operating angle, the control is switched to the throttle control that mainly controls the intake air amount by the opening of the throttle valve 32. . Thereby, deterioration of torque responsiveness can be avoided reliably.

[Specific Processing in Embodiment 1]
FIG. 7 is a flowchart of a routine executed by the ECU 50 when acquiring the learning value of the reference operating angle in the present embodiment. This routine is executed while the operating angle change speed is made slower than normal by the processing of the routine shown in FIG.

  According to the routine shown in FIG. 7, first, it is determined whether or not an edge output is issued from the position sensor 28 (step 100). If it is determined that an edge output has been issued, it is determined whether or not learning of the edge output generated this time has been completed among the three edge outputs generated by the position sensor 28 (step 102).

  If learning about the edge output generated this time has not been completed in step 102, next, the output value of the rotation amount sensor 26 is read (step 104). Subsequently, it is determined whether or not the operating angle is changing in the direction of reduction (hereinafter also referred to as “closed side”) (step 106).

  In the ECU 50, when the control shaft driving device 16 is driven in the direction in which the operating angle is reduced, the closing side flag is turned on. Therefore, when the closing side flag is on in step 106, it is determined that the operating angle is changing in the direction of decreasing. In this case, the rotation amount sensor value read in step 104 is stored as a learning value on the closing side (step 108). Thereafter, the fact that the learning in the direction in which the working angle is reduced is stored for the edge output (step 110).

  On the other hand, if the closing side flag is OFF in step 106, it is determined that the operating angle is changing in the direction in which the operating angle increases (hereinafter also referred to as “opening side”). In this case, the rotation amount sensor value read in step 104 is stored as the learning value on the opening side (step 112). Thereafter, the fact that the learning of the direction in which the operating angle is enlarged for the edge output is completed is stored (step 114).

  In the present embodiment, the routine shown in FIG. 7 described above is repeatedly executed for each edge output of the position sensor 28, whereby a learning value for each edge output can be acquired. In the present embodiment, for each edge output, the learning value can be acquired by actually moving the control axis 14 in both the working angle reduction direction (closed side) and the working angle widening direction (open side). . For this reason, since each learning value can be acquired with particularly high accuracy, an abnormality of the variable working angle mechanism 12 can be determined with particularly high accuracy.

  FIG. 8 is a flowchart of a routine executed by the ECU 50 when determining an abnormality of the variable working angle mechanism 12 in the present embodiment. According to the routine shown in FIG. 8, first, it is determined whether or not an edge output is issued from the position sensor 28 (step 120). If it is determined that an edge output has been issued, it is determined whether or not learning about the edge output that has occurred this time has been completed (step 122).

  If it is determined in step 122 that learning about the edge output generated this time has been completed, then the output value of the rotation amount sensor 26 is read (step 124). Subsequently, it is determined whether or not the operating angle is changing in the direction of reduction (step 126). In step 126, if the closing side flag is ON, it is determined that the operating angle is changing in the direction of reduction. In this case, the value stored as the learning value on the closing side is read (step 128). On the other hand, if the closing side flag is OFF in step 126, it is determined that the operating angle is changing in the increasing direction. In this case, the value stored as the learning value on the open side is read (step 130).

  Subsequently, a deviation between the rotation amount sensor value read in step 124 and the learned value read in step 128 or 130 is calculated (step 132). That is, the deviation is calculated by subtracting the latter value from the former value. Next, the absolute value of the deviation calculated in step 132 is compared with a predetermined determination value (step 134). As a result of the comparison, when the absolute value of the deviation is smaller than the determination value, it can be determined that there is no significant deviation between the actual operating angle of the intake valve 10 and the command value (control target value) of the ECU 50. Therefore, in this case, it is determined that the variable working angle mechanism 12 is normal (step 136).

  On the other hand, when the absolute value of the deviation is greater than or equal to the determination value, it can be determined that a significant deviation has occurred between the actual operating angle of the intake valve 10 and the command value of the ECU 50. Therefore, in this case, it is determined that an abnormality has occurred in the variable working angle mechanism 12 (step 138).

  According to the processing of the routine of FIG. 8 described above, the change direction of the operating angle (the moving direction of the control shaft 14) is determined and compared with the learned value for each of the changing directions. Judgment can be made. Therefore, even when the position sensor 28 is used in which hysteresis occurs in the output depending on the moving direction of the control shaft 14, the abnormality determination can be performed with high accuracy.

FIG. 9 is a flowchart of a routine executed by the ECU 50 in order to make the operating angle change speed slower than normal during learning in the present embodiment. According to the routine shown in FIG. 9, first, the base target operating angle value θ ₁ is calculated (step 150). The base target operating angle value θ ₁ is an operating angle of the intake valve 10 that is necessary for the engine to suck an air amount corresponding to the required torque. The base target operating angle value θ ₁ is calculated based on, for example, the accelerator pedal opening, the engine speed, and the like.

Next, the previous final target operating angle value θ ₂ is read (step 152). This value is a value calculated in step 160, 172, or 178 described later when this routine was executed last time. Subsequently, the normal target operating angle change limit amount Δθ is read (step 154). This target operating angle change limit amount Δθ is set in advance as a value that defines the normal operating angle change speed, and is a value representing the operating angle change amount per execution cycle of this routine.

Subsequently, it is determined whether or not learning (both directions of the working angle reduction direction and the working angle enlargement direction) for each edge output has been completed (step 156). When learning about each edge output is completed, it is not necessary to perform learning thereafter. Therefore, in this case, the throttle control request is turned off (step 158). When the throttle control request is turned off, normal intake air amount control based on a change in the operating angle of the intake valve 10 is executed. Subsequently, based on the previous final target working angle value θ ₂ read in step 152 and the normal target working angle change limit amount Δθ read in step 154, the final target working angle value this time is determined. Is calculated (step 160). That is, in step 160, when the operating angle changes in the enlargement direction, (θ ₂ + Δθ) is set as the final target operating angle value, and when the operating angle changes in the reduction direction, (Θ ₂ −Δθ) is set as the final target operating angle value. The ECU 50 operates the control shaft driving device 16 so that the actual working angle detected by the rotation amount sensor 26 matches the final target working angle value.

On the other hand, if there is an edge output for which learning has not been completed in step 156, it is necessary to perform learning, and therefore it is necessary to make the operating angle change rate slower than normal. Therefore, in this case, the throttle control request is turned on (step 162). In a state where the throttle control request is turned on, the intake air amount is controlled mainly by changing the opening of the throttle valve 32. Subsequently, it is determined whether or not the previous final target operating angle value θ ₂ read in step 152 is larger than the base target operating angle value θ ₁ calculated in step 150 (step 164).

In the present embodiment, learning is performed only when the actual operating angle is larger than the base target operating angle value θ ₁ . If the actual working angle is greater than the base target working angle value θ ₁ , the amount of intake air can be made equal to the target value by reducing the amount of air with the throttle valve 32. Therefore, learning can be performed without affecting the engine torque. On the other hand, since the intake air amount is limited by the intake valve 10 in the range where the actual operating angle is smaller than the base target operating angle value θ ₁ , the target intake air amount is no matter how much the throttle valve 32 is opened. (Target engine torque) cannot be obtained. Therefore, from the viewpoint of drivability, it is desirable not to perform learning in a range where the actual operating angle is smaller than the base target operating angle value θ ₁ .

Therefore, in the present embodiment, if the previous final target operating angle value θ ₂ is not larger than the base target operating angle value θ _{1 in} step 164, learning is not performed, and normal control is returned to. did. That is, in this case, the processing from step 158 onward is executed.

On the other hand, when the previous final target operating angle value θ ₂ is larger than the base target operating angle value θ _{1 in} step 164, learning is executed. In this case, first, the target working angle change limit amount Δφ at the time of learning is read (step 166). The target operating angle change limit amount Δφ during learning is set in advance as a value smaller than the normal target operating angle change limit amount Δθ. Therefore, when the final target working angle value this time is calculated using the target working angle change limit amount Δφ at the time of learning, the working angle change speed becomes slower than normal.

Next, the output value of the rotation amount sensor 26, that is, the actual operating angle θ ₃ is read (step 168). Subsequently, it is determined whether the operating angle is changing in the direction of reducing or changing in the direction of increasing (step 170). When the operating angle is changing in the direction of reduction, that is, when the closing side flag is ON, the target operating angle change during learning is determined from the previous final target operating angle value θ ₂ read in step 152 above. The value obtained by subtracting the limit amount Δφ (θ ₂ −Δφ) is set as the final target operating angle value (step 172). In this case, it is next determined whether or not the actual operating angle θ ₃ read in step 168 is equal to or smaller than the edge generation lower limit operating angle value α (step 174).

In the region where the actual operating angle is smaller than the edge generation lower limit operating angle value α, the edge output of the position sensor 28 is not emitted, so it is not necessary to change the operating angle for learning. Therefore, if the actual operating angle θ ₃ is equal to or smaller than the edge generation lower limit operating angle value α in step 174, the closing side flag is set to switch the operating direction of the control shaft drive device 16 to the operating angle expanding direction. It is turned off (step 176). Thereby, after this, the process of acquiring the learning value in the working angle expansion direction is executed for each edge output (when the process is not completed).

On the other hand, when the actual operating angle θ ₃ is larger than the edge generation lower limit operating angle value α in step 174, it is necessary to continue learning toward a region with a smaller operating angle. Therefore, in this case, learning is continued while the closing side flag is kept on.

On the other hand, if it is determined in step 170 that the closing side flag is OFF, that is, if it is determined that the operating angle is changing in the increasing direction, the previous final target read in step 152 is then executed. The final target operating angle value for this time is (θ ₂ + Δφ), which is a value obtained by adding the target operating angle change limit amount Δφ during learning to the operating angle value θ ₂ (step 178). In this case, it is next determined whether or not the actual operating angle θ ₃ read in step 168 is equal to or larger than the edge generation upper limit operating angle value β (step 180).

In the region where the actual operating angle is larger than the edge generation upper limit operating angle value β, the edge output of the position sensor 28 is not emitted, so there is no need to change the operating angle for learning. Therefore, if the actual operating angle θ ₃ is equal to or larger than the edge generation upper limit operating angle value β in step 180, the closing side flag is set to switch the operating direction of the control shaft drive device 16 to the operating angle reducing direction. It is turned on (step 182). Thereby, after this, the process of acquiring the learning value in the working angle reduction direction is executed (when the process is not completed) for each edge output.

On the other hand, when the actual operating angle θ ₃ is smaller than the edge generation upper limit operating angle value β in step 180, it is necessary to continue learning toward a region with a larger operating angle. Therefore, in this case, learning is continued while the closing side flag is kept off.

  The learning value acquisition process as described above needs to be executed when the variable working angle mechanism 12 is in a normal state. Otherwise, an inappropriate value is learned, and proper abnormality determination cannot be performed. For example, when the new vehicle is completed or when maintenance is completed at a maintenance shop, it can be guaranteed that the variable working angle mechanism 12 is in a normal state. Therefore, it is desirable to perform learning or relearning when a new vehicle is completed or maintenance is completed. Therefore, in the present embodiment, when a new vehicle is completed or maintenance is completed, the operator operates the external switch to clear the learning history, and then causes the ECU 50 to perform learning or relearning.

  FIG. 10 is a flowchart of a routine that the ECU 50 executes when the external switch is operated. An operator turns on an external switch (not shown) when a new vehicle is completed or maintenance is completed. The ECU 50 determines whether or not the external switch is turned on (step 190). If it is detected that the external switch is turned on, the ECU 50 deletes the learning value stored for each edge output (step 192). Thereby, learning is performed thereafter by the processing of the routine shown in FIG. As a result, an appropriate learning value in a normal state can be acquired.

  In the first embodiment described above, the ECU 50 executes the routine of FIG. 7 so that the “learning means” in the first, fourth, seventh and tenth inventions is the routine of FIG. 9 is executed, the "abnormality determination means" in the third invention executes the routine of FIG. 9, and the "displacement speed reducing means" in the fifth invention executes the processing of the routine of FIG. By executing this, the “intake air amount control means” in the sixth aspect of the invention is realized.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIG. 11 and FIG. 12. The description will focus on the differences from the first embodiment described above, and the same matters will be described. Simplify or omit. The hardware configuration of this embodiment is the same as the configuration of FIG. 1 described above.

  As described above, hysteresis occurs in the position where the edge output of the position sensor 28 is generated in accordance with the moving direction of the control shaft 14. In the first embodiment described above, in order to cope with this, by actually moving the control shaft 14 in both the working angle reduction direction and the working angle enlargement direction, each edge output of the position sensor 28 is changed in both directions. The learning value is to be acquired. According to such a method, the learning value can be obtained with high accuracy in each of the operating angle reduction direction and the operating angle expansion direction. On the other hand, the time required for learning tends to be long.

  Therefore, in the present embodiment, the learning value is acquired by actually moving the control shaft 14 in the working angle reduction direction, but the hysteresis value stored in advance in the learning value in the working angle reduction direction is obtained for the working angle expansion direction. The learning value was determined by adding.

[Specific Processing in Second Embodiment]
FIG. 11 is a flowchart of a routine executed by the ECU 50 when acquiring the learning value of the reference working angle in the present embodiment. According to the routine shown in FIG. 11, first, it is determined whether or not an edge output is issued from the position sensor 28 (step 200). If it is determined that an edge output has been issued, it is determined whether or not learning about the edge output that has occurred this time has been completed (step 202).

If the learning about the edge output is not completed in step 202, the output value of the rotation amount sensor 26 is read as θ ₄ (step 204). Subsequently, it is determined whether or not the operating angle is changing in the direction of reduction (closed side) (step 206).

  In the above-described step 206, when the operating angle is changing in the increasing direction, learning is not performed in this embodiment. Therefore, in this case, the execution of the current routine is terminated as it is.

On the other hand, when it is determined in step 206 that the operating angle is changing in the direction of reducing, the rotation amount sensor value θ ₄ read in step 204 is set to the closed side (operating angle reducing direction). ) Is stored as a learning value (step 208). Subsequently, a value obtained by adding a hysteresis value stored in advance to the learning value θ ₄ on the closing side is calculated as θ ₅ (step 210). Next, the calculated value θ ₅ is stored as a learning value on the opening side (direction of operation angle expansion) (step 212). Thereafter, the fact that learning about the edge output has been completed is stored (step 214).

In the position sensor 28 having the structure as described above, the variation of the hysteresis value due to the individual difference is relatively small and accurately matches the design value. In the present embodiment, the ECU 50 stores design hysteresis values in advance. Therefore, as shown in the routine described above, the learned value θ ₅ in the operating angle expansion direction can be accurately calculated by adding the hysteresis value to the learned value θ ₄ in the operating angle reduction direction (FIG. 6). reference). For this reason, in the operating angle expansion direction, the learning process by actually moving the control shaft 14 can be omitted, so that learning can be completed in a short time.

  In the present embodiment, the routine shown in FIG. 11 described above is repeatedly executed for each edge output of the position sensor 28, whereby a learning value for each edge output can be acquired.

FIG. 12 is a flowchart of a routine executed by the ECU 50 in order to make the operating angle change speed slower than normal during learning in the present embodiment. According to the routine shown in FIG. 12, first, the base target operating angle value θ ₁ necessary for causing the engine to inhale the air amount corresponding to the required torque is calculated (step 220).

Next, the previous final target operating angle value θ ₂ is read (step 222). This value is a value calculated in step 228 or 236 described later when this routine was executed last time. Subsequently, the normal target operating angle change limit amount Δθ is read (step 224).

Subsequently, it is determined whether or not the previous final target operating angle value θ ₂ read in step 224 is larger than the base target operating angle value θ ₁ calculated in step 220 (step 226). In this step 226, if the previous final target operating angle value θ ₂ is less than or equal to the base target operating angle value θ ₁ , it can be determined that the actual operating angle is changing in the enlargement direction. In the present embodiment, learning is not performed for the working angle expansion direction, so there is no need to slow down the working angle change speed. Therefore, in this case, (θ ₂ + Δθ), which is a value obtained by adding the normal target operating angle change limit amount Δθ to the previous final target operating angle value θ ₂ , is calculated as the final target operating angle value. (Step 228). In this case, the closing flag is turned off to indicate that the operating angle is changing in the enlargement direction (step 230).

On the other hand, when the previous final target operating angle value θ ₂ is larger than the base target operating angle value θ _{1 in} step 226, it can be determined that the actual operating angle is changing in the reduction direction. In this case, it is next determined whether or not learning for each edge output has been completed (step 232).

If it is determined in step 232 that learning for any edge output has not been completed, it is necessary to perform learning, so that the operating angle change speed needs to be slower than normal. . Therefore, in this case, the target operating angle change limit amount Δφ at the time of learning is read (step 234). Next, (θ ₂ −Δφ), which is a value obtained by subtracting the target working angle change limit Δφ at the time of learning from the previous final target working angle value θ ₂ , is calculated as the final target working angle value (step 236). The target operating angle change limit amount Δφ during learning is a value smaller than the normal target operating angle change limit amount Δθ. For this reason, according to said process, a working angle change speed can be made slower than normal time, and a learning precision can be improved.

On the other hand, if it is determined in step 232 that learning for each edge output has been completed, it is not necessary to perform learning, so there is no need to slow down the operating angle change rate. Therefore, in this case, step 234 is skipped, and the final target operating angle value is calculated (step 236). That is, in this case, (θ ₂ −Δθ), which is a value obtained by subtracting the normal target operating angle change limit Δθ from the previous final target operating angle value θ ₂ , is calculated as the final target operating angle value. . In this case, the closing side flag is turned on to indicate that the operating angle is changing in the reduction direction (step 238).

  As described above, according to the present embodiment, it is only necessary to perform learning for the operating angle reduction direction, and learning can be omitted for the operating angle expansion direction. For this reason, learning can be completed early. In the present embodiment, the processing executed by the ECU 50 when determining the abnormality of the variable working angle mechanism 12 is the same as that in the first embodiment (FIG. 8).

  In the second embodiment described above, the ECU 50 corresponds to the “hysteresis storage means” in the eighth invention. Further, when the ECU 50 executes the routine shown in FIG. 11, the “learning means” in the eighth invention executes the routine shown in FIG. "Reducing means" are realized respectively.

Embodiment 3 FIG.
Next, the third embodiment of the present invention will be described with reference to FIG. 13 to FIG. 15. The description will focus on the differences from the above-described embodiment, and the description of the same matters will be simplified. Or omit. The hardware configuration of this embodiment is the same as the configuration of FIG. 1 described above.

  In the above-described embodiment, when the abnormality of the variable working angle mechanism 12 is determined, the abnormality cannot be determined unless learning about the generated edge output is completed (step 122 in FIG. 8). For this reason, the abnormality determination may not be executed until the learning for each of the three edge outputs emitted by the position sensor 28 is completed.

  In the present embodiment, the following processing is performed in order to make it possible to perform abnormality determination even when learning has not been completed for some edge outputs. FIG. 13 is a diagram for explaining a characteristic part of the present embodiment. As shown in FIG. 13, in this embodiment, the design value γ of the operating angle interval between the edge outputs is stored in advance in the ECU 50. If there is no influence of a design tolerance described later, a learning value of a certain edge output and a learning value of an edge output adjacent thereto are different from each other by the design value γ. Therefore, in the present embodiment, when learning is first completed for any one of the three edge outputs, the learning value is set to the design value γ (2γ in the case of two edge outputs separated from each other). ) Is added (or subtracted), and the value is used as a provisional learning value for the other two edge outputs. Thereby, in this embodiment, if learning is completed for any one of the three edge outputs, the above-described provisional learning values (hereinafter referred to as “provisional learning values”) are also applied to the other two edge outputs. It is possible to start the abnormality determination.

  However, as described above, due to the influence of the design tolerance, the actual working angle interval between the edge outputs does not necessarily coincide with the design value γ. In other words, the temporary learning value may include a design tolerance error. For this reason, when the abnormality determination is performed using the provisional learning value, there is a possibility that the abnormality is erroneously determined although it is normal. In the present embodiment, in order to reliably prevent such erroneous determination, the determination criterion is relaxed when abnormality determination is performed using a provisional learning value.

  In the present embodiment, as in the second embodiment described above, the learning value is acquired by actually moving the control shaft 14 in the operating angle reduction direction. However, the operating angle reduction direction is the same as that in the operating angle reduction direction. The learning value is obtained by adding a hysteresis value stored in advance to the learning value.

[Specific Processing in Embodiment 3]
FIG. 14 is a flowchart of a routine executed by the ECU 50 when acquiring the learning value of the reference working angle in the present embodiment. Steps 200 to 214 of the routine shown in FIG. 14 are the same as the routine of FIG. 11 of the second embodiment described above. For this reason, description of this part is omitted.

  After it is stored in step 214 of the routine shown in FIG. 14 that learning about the edge output generated this time is completed, the edge output learned this time is the three edge outputs generated by the position sensor 28. It is determined whether or not it is the first learned item (step 240). If it is determined that the edge output learned this time is the one learned first, then the learning value obtained this time (the value stored in steps 208 and 212 above) is stored in advance. Based on the design value γ of the working angle interval between the edge outputs thus obtained, provisional learning values for the other two edge outputs are calculated (step 242).

  That is, in step 242, for each of the other two edge outputs, the value obtained by adding (or subtracting) γ (or 2γ) to the value stored in step 208 is the learning on the closed side (working angle reduction direction). A value obtained by adding (or subtracting) γ (or 2γ) to the value stored in the above step 212 is stored as a learning value on the opening side (working angle expansion direction). In this way, when the process of calculating the temporary learning value is completed, the execution of the abnormality determination is permitted (step 244).

  As described above, according to the routine processing shown in FIG. 14, it is possible to execute abnormality determination when learning is completed for any one of the three edge outputs of the position sensor 28. For this reason, abnormality determination can be started at an early stage.

  Note that even after learning is completed for any one of the three edge outputs, the routine shown in FIG. 14 is repeatedly executed, and true learning values are acquired for the other two edge outputs. When the true learning value is acquired, the temporary learning value is replaced with the true learning value.

  FIG. 15 is a flowchart of a routine executed by the ECU 50 when determining an abnormality of the variable working angle mechanism 12 in the present embodiment. According to the routine shown in FIG. 15, it is first determined whether or not an edge output is issued from the position sensor 28 (step 250). If it is determined that an edge output has been issued, it is next determined whether or not execution of abnormality determination is permitted (step 252). If the permission in step 244 of FIG. 14 described above has been made, the determination in step 252 is affirmed.

  If the determination in step 252 is affirmed, next, the output value of the rotation amount sensor 26 is read (step 254). Subsequently, it is determined whether or not the operating angle is changing in the direction of reduction (step 256). In step 256, if the closing side flag is ON, it is determined that the operating angle is changing in the direction of decreasing. In this case, the value stored as the learning value on the closing side is read (step 258). On the other hand, if the closing side flag is OFF in step 256, it is determined that the operating angle is changing in the increasing direction. In this case, the value stored as the learning value on the open side is read (step 260).

  Subsequently, a deviation between the rotation amount sensor value read in step 254 and the learning value read in step 258 or 260 is calculated (step 262). That is, the deviation is calculated by subtracting the latter value from the former value. Next, a determination value for abnormality determination stored in advance is read (step 264).

  Subsequently, it is determined whether or not learning about the edge output generated this time (the edge output generated in step 250 above) has been completed (step 266). If the edge output generated this time is one for which learning has not been completed, the learning value read in step 258 or 260 is a temporary learning value. For this reason, the learning value may include a design tolerance error. Therefore, when learning about the edge output that has occurred this time has not been completed, processing for relaxing the determination criteria is executed in order to prevent erroneous determination (step 268). In step 268, specifically, the normal determination value read in step 264 is replaced with a value obtained by adding the predetermined value κ. The predetermined value κ is a value set in advance according to design tolerance or the like.

  Following the processing in step 268, the absolute value of the deviation calculated in step 262 is compared with the determination value (step 270). As a result of the comparison, when the absolute value of the deviation is smaller than the determination value, it is determined that the variable working angle mechanism 12 is normal (step 272). On the other hand, if the absolute value of the deviation is greater than or equal to the determination value, it is determined that an abnormality has occurred in the variable working angle mechanism 12 (step 274). When the process of step 268 is executed, the determination value is enlarged by an amount corresponding to a design tolerance or the like. For this reason, the range determined to be normal in step 270 is wide. Therefore, even when an error is included in the provisional learning value, erroneous determination can be reliably prevented.

  On the other hand, if it is determined in step 266 that learning about the edge output that has occurred this time has been completed, the learning value read in step 258 or 260 is a true learning value, so the error is It can be judged that it is not included. Therefore, in this case, step 268 is skipped and the process of step 270 is executed. As a result, the abnormality determination is made using the normal determination value read in step 264 as it is. Therefore, the abnormality determination can be performed with the original high accuracy.

  In the third embodiment described above, the ECU 50 corresponds to the “output interval storage means” in the eleventh aspect of the invention. Further, when the ECU 50 executes the routine shown in FIG. 14, the “learning means” according to the eleventh aspect of the invention executes the processes of steps 266 and 268 described above. "Mitigation measures" are realized respectively.

  In each of the embodiments described above, the control shaft 14 has been described as moving linearly in the axial direction. However, in the present invention, the control shaft 14 rotates and the operating angle of the intake valve 10 depends on the rotational position. The present invention can also be applied to a variable working angle mechanism configured to change the angle.

It is a figure for demonstrating the system configuration | structure of Embodiment 1 of this invention. It is a figure which shows the relationship between the actual operating angle of an intake valve, and the output value of a rotation amount sensor. It is a figure which shows the relationship between the actual operating angle of an intake valve, and the output value of a position sensor. It is a figure which expands and shows a position sensor. It is a figure which shows the output of a position sensor in detail. It is a figure which shows the time-dependent change of the output of a rotation amount sensor, and the output of a position sensor at the time of moving a control axis in both directions. It is a flowchart of the routine performed in Embodiment 1 of the present invention. It is a flowchart of the routine performed in Embodiment 1 of the present invention. It is a flowchart of the routine performed in Embodiment 1 of the present invention. It is a flowchart of the routine performed in Embodiment 1 of the present invention. It is a flowchart of the routine performed in Embodiment 2 of this invention. It is a flowchart of the routine performed in Embodiment 2 of this invention. It is a figure for demonstrating the characteristic part of Embodiment 3 of this invention. It is a flowchart of the routine performed in Embodiment 3 of the present invention. It is a flowchart of the routine performed in Embodiment 3 of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Intake valve 12 Variable working angle mechanism 14 Control shaft 16 Control shaft drive device 16A Output shaft 18 Fastening member 20 Roller arm 22 Swing cam 24 Rocker arm 26 Rotation amount sensor 28 Position sensor 30 Target 32 Throttle valve 50 ECU

Claims (12)

A control shaft and an actuator for moving the control shaft, and when the control shaft is moved in a predetermined direction, an operating angle of a valve provided in a cylinder of the internal combustion engine is expanded, and the control shaft is A variable working angle mechanism that reduces the working angle when moved in a direction opposite to a predetermined direction;
A rotation amount sensor for detecting the rotation amount of the actuator;
A position sensor for detecting the position of the control axis;
Learning means for acquiring a learning value based on a relative relationship between the output of the rotation amount sensor and the output of the position sensor;
An abnormality determination device for a variable working angle mechanism, comprising: The rotation amount sensor emits a continuous output according to the rotation amount of the actuator,
The position sensor emits an output when the control axis reaches a plurality of specific positions,
The abnormality determination device for a variable working angle mechanism according to claim 1, wherein the learned value is a value learned from an output value of the rotation amount sensor at a timing when an output of the position sensor is generated.   3. An abnormality determining unit that determines whether or not the variable working angle mechanism is abnormal based on the learning value, the output of the rotation amount sensor, and the output of the position sensor. The abnormality determination device for the variable working angle mechanism as described.   The abnormality determination device for a variable operating angle mechanism according to any one of claims 1 to 3, wherein the learning means acquires the learned value in association with a change direction of the operating angle.   5. The apparatus according to claim 1, further comprising: a displacement speed reducing unit that slows a displacement speed of the control shaft as compared with a normal displacement speed when the learning unit performs learning. An abnormality determination device for a variable working angle mechanism according to the item. The valve is an intake valve;
A throttle valve installed in the intake passage of the internal combustion engine;
Normally, the intake air amount is controlled mainly by changing the operating angle of the intake valve, and when the learning means performs learning, the intake air amount is mainly changed by changing the opening of the throttle valve. Intake air amount control means to control;
The abnormality determination device for a variable working angle mechanism according to claim 5, comprising:   The learning means acquires a learning value when the working angle is actually changed in the enlargement direction and a learning value when the working angle is actually changed in the reduction direction, respectively. Item 7. The abnormality determination device for a variable working angle mechanism according to any one of Items 1 to 6. Information on the hysteresis existing between the output of the position sensor emitted in the process of changing the working angle in the enlargement direction and the output of the position sensor issued in the process of changing the working angle in the reduction direction was stored. Comprising hysteresis storage means,
The learning means obtains a learning value by actually changing the working angle for any one direction of the working angle expansion direction and the working angle reduction direction, and for the direction opposite to the one direction, The abnormality determination device for a variable working angle mechanism according to any one of claims 1 to 7, wherein the learning value is calculated based on a learning value in one direction and information stored in the hysteresis storage means.   9. The abnormality determining device for a variable working angle mechanism according to claim 8, wherein the one direction is a working angle reducing direction. The position sensor emits an output when the control axis reaches a plurality of specific positions,
The variable working angle mechanism according to claim 1, wherein the learning unit performs learning for each of the plurality of outputs corresponding to the plurality of specific positions to acquire a learning value. Abnormality judgment device. Output interval storage means for storing information relating to the plurality of output intervals;
The learning means obtains temporary learning values for other outputs based on a learning value for an output for which learning has been completed first among the plurality of outputs and information stored in the output interval storage means. The abnormality determining device for a variable working angle mechanism according to claim 10, further comprising a calculating unit.   The variable working angle according to claim 11, further comprising a determination reference relaxation unit that relaxes a reference for determining that there is no abnormality when the abnormality determination unit determines whether there is an abnormality based on the temporary learning value. Mechanism abnormality determination device.

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