JP2010180865A - Variable valve gear of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable valve gear of internal combustion engine capable of curbing the increase in fuel consumption and the degradation in emission by quickly correcting a position detection value while suppressing degrading of durability in an actuator and a lift amount varying mechanism. <P>SOLUTION: An electronic controller 100 counts a position count value based on a pulse signal output from position sensors S4, S5 to calculate a position detection value indicating a position of a control shaft 340 of a lift amount varying mechanism 300, based on the value counted. Then, the electronic controller 100 drives a motor 210 so as to approximate the position detection value calculated to a value corresponding to a target position. In the electronic controller 100, a position detection value corresponding to a given rotary phase is preliminarily stored as a reference value. Based on an electric angle counted values produced on the basis of pulse signals of electric angle sensors S1, S2, S3, when the motor 210 is judged to be in the given rotary phase, the electronic controller 100 practices a learning process for correcting the position detection value so as to approximate the position detection value to the reference value. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine including a lift amount changing mechanism that changes a working angle and a lift amount of an engine valve.

  As a lift amount changing mechanism that changes the working angle and lift amount of an engine valve, a mechanism that changes the working angle and lift amount by displacing a control shaft in the axial direction is known. This lift amount changing mechanism increases the operating angle and the lift amount when the control shaft is displaced toward one side in the axial direction, and the operating angle and the lift amount when the control shaft is displaced toward the other side in the axial direction. Decrease.

  A variable valve operating apparatus for an internal combustion engine equipped with such a lift amount changing mechanism has an actuator that converts the rotational movement of the motor into a linear movement of the output shaft and outputs it, and controls the motor to the output shaft of the actuator. The operating angle and lift amount of the engine valve are controlled by displacing the connected control shaft in the axial direction.

  Such a variable valve apparatus is provided with a position sensor that outputs a pulse signal as the motor rotates. The variable valve apparatus calculates a position count value based on the pulse signal output from the position sensor. Counting is performed, and a position detection value indicating the position of the control axis is calculated based on the position count value. That is, since the displacement amount of the control shaft changes in proportion to the rotation angle of the motor, the control from the reference position is controlled based on the position count value that increases or decreases corresponding to the rotation angle and rotation direction of the motor using this relationship. The displacement amount of the shaft is estimated, and based on this, a position detection value indicating the position of the control shaft is calculated to detect the position of the control shaft.

  Then, the variable valve operating apparatus feedback-controls the driving amount of the motor so that the position of the control shaft thus detected is brought close to the position corresponding to the target operating angle and lift amount. And change the lift amount.

  By the way, since the position count value is not counted by the variable valve device while the engine is stopped, if the control shaft is displaced while the engine is stopped, the displacement is not reflected in the position detection value. The position of the control axis will not correspond. As a result, the operating angle and the lift amount cannot be appropriately controlled when the internal combustion engine is operated next time.

  Note that the urging force of a valve spring that urges the engine valve in the valve closing direction is constantly acting on the control shaft of the lift amount changing mechanism. Therefore, when the temperature of the lubricating oil is high and the friction in the lift amount changing mechanism is reduced, or when the engine stop state continues for a long time, the control shaft causes the operating angle and lift amount to be increased by the urging force of the valve spring. As described above, the control shaft may be displaced while the engine is stopped.

  On the other hand, in the variable valve operating apparatus for an internal combustion engine described in Patent Document 1, the control shaft of the lift amount changing mechanism is displaced toward one side in the axial direction, and the control shaft reaches the movable limit position. Abutting learning for correcting the value of the position detection value is performed when the member abuts against another member and is no longer displaced. By performing this butting learning, the position detection value can be accurately corrected with the control axis at the movable limit position on the basis of the movable limit position. The deviation between the position of the control shaft detected by the valve device and the actual position of the control shaft can be eliminated.

JP 2007-187061 A

  However, in such abut learning, since the control shaft is driven to the movable limit position, it is changed until the operating angle and lift amount of the engine valve are maximized or minimized. Therefore, when such abut learning is performed during engine operation, the following inconvenience occurs due to the change in the operating angle and lift amount of the engine valve.

  For example, in a variable valve system that changes the operating angle and lift amount of the intake valve, if the abutment learning is performed by displacing the control shaft in the direction of decreasing the operating angle and lift amount, the learning is completed. During this time, the operating angle and lift amount of the intake valve are reduced. As a result, the amount of intake air is limited until the learning is completed, and the engine output is greatly reduced.

  In addition, when the abutment learning is performed by displacing the control shaft in the direction to increase the working angle and lift amount of the intake valve, the working angle and lift amount of the intake valve increase accordingly, and the exhaust valve Will increase the overlap. Therefore, when such abutment learning is performed at a low load, the engine combustion becomes unstable as the overlap increases, and misfire is likely to occur.

  In order to suppress the occurrence of such inconvenience, it is also conceivable to perform the abutment learning only when the operating angle and the lift amount need to be maximized or minimized with engine operation. However, when such a configuration is adopted, there are fewer opportunities for performing abutting learning, and the state in which the engine valve operating angle and lift amount cannot be appropriately controlled continues to increase fuel consumption and output. It will cause a decline.

  In the butting learning, the motor continues to be driven until the control shaft reaches the movable limit position as described above, comes into contact with another member, and is no longer displaced. For this reason, each time the abutment learning is executed, the control shaft comes into contact with another member at the movable limit position, and there is a concern that the durability of the actuator and the lift amount changing mechanism may be reduced due to an impact generated at that time. Such a decrease in durability is not limited to the variable valve system that changes the operating angle and lift amount of the intake valve as described above, but also in the variable valve system that changes the operating angle and lift amount of the exhaust valve. Can occur.

  The present invention has been made in view of the above circumstances, and its purpose is to quickly correct the position detection value while suppressing the decrease in the durability of the actuator and the lift amount changing mechanism, thereby increasing the fuel consumption and reducing the emission. It is an object of the present invention to provide a variable valve operating apparatus for an internal combustion engine that can suppress deterioration.

In the following, means for achieving the above object and its effects are described.
The invention according to claim 1 is a lift amount changing mechanism for changing the operating angle and the lift amount of the engine valve corresponding to the position of the control shaft in the axial direction, and converts the rotational motion of the motor into linear motion of the control shaft. And an actuator for displacing the control shaft in the axial direction, and a position sensor for outputting a pulse signal as the motor rotates. A reference position of the control shaft based on the pulse signal output by the position sensor A position count value corresponding to the displacement from the position is counted, a position detection value indicating the position of the control shaft is calculated based on the position count value, and the position detection value corresponds to a target operating angle and lift amount. In the variable valve operating apparatus for an internal combustion engine that drives the motor so as to approach a value, the variable valve device includes a rotation phase determination unit that determines that the motor is in a predetermined rotation phase, A learning process for storing the corresponding position detection value in advance as a reference value and correcting the position detection value so as to approach the reference value when it is determined that the motor is in the predetermined rotational phase. The gist is to do.

  According to the above configuration, when the motor is in the predetermined rotation phase, the position detection value actually calculated is compared with the reference value stored in advance as the position detection value corresponding to the predetermined rotation phase. A learning process for correcting the position detection value so as to approach the reference value is executed. That is, according to the configuration of the first aspect, when the rotational phase of the motor is determined to be the predetermined rotational phase, the position detection value is compared with the reference value, whereby the control shaft is moved to the movable limit. The amount of displacement of the position detection value can be grasped without being displaced to the position. Then, by executing a learning process for correcting the position detection value so as to approach the reference value, it is possible to reduce the deviation of the position detection value. Therefore, unlike conventional variable valve gears that perform abutting learning, where it is inevitable that the control shaft collides with other members as learning is performed, learning without causing the control shaft to collide with other members. Processing can be executed, and a decrease in durability of the actuator and the lift amount changing mechanism can be suppressed.

  Further, unlike the conventional variable valve device that performs abutting learning in which the execution opportunity is limited because the working angle and the lift amount need to be maximized or minimized, the variable valve device according to claim 1, According to the apparatus, the learning process can be performed when the rotational phase of the motor becomes a predetermined rotational phase during engine operation. Therefore, there are more opportunities for execution of learning processing during engine operation than in a conventional variable valve device that performs abutment learning, and the deviation of the position detection value can be quickly reduced.

  That is, according to the configuration of the first aspect, the position detection value is promptly corrected by suppressing the decrease in durability of the actuator and the lift amount changing mechanism, thereby suppressing the increase in fuel consumption and the deterioration of emission. Will be able to.

In the learning process, it is desirable that the position detection value is matched with the reference value, and correction is performed so that the shift of the position detection value can be completely eliminated.
According to a second aspect of the present invention, in the variable valve operating apparatus for an internal combustion engine according to the first aspect, the rotation phase determining means refers to an electrical angle count that is referred to for switching the energized phase of the motor when the motor is driven. An electrical angle sensor that outputs a pulse signal with the rotation of the motor to generate a value, and the electrical angle count with the rotation of the motor when the motor is in a rotation phase other than the predetermined rotation phase. While the value periodically changes in a predetermined change mode, when the motor is in the predetermined rotation phase, the electrical angle count value changes in a change mode different from the predetermined change mode as the motor rotates. And the rotational phase of the motor is based on the fact that the change mode of the electrical angle count value is different from the predetermined change mode. Determining that a rotation phase as its gist.

  According to a third aspect of the present invention, in the variable valve operating apparatus for an internal combustion engine according to the second aspect, the rotational phase determining means has eight magnetic poles arranged in a circle so that the N poles and the S poles are alternately arranged. An 8-pole three-phase electrical angle counter configured to include an installed rotor and the three electrical angle sensors provided in a position that can be opposed to each of the magnetic poles with a phase shift; The gist of the invention is that the arrangement of the two magnetic poles is made nonuniform in the portion corresponding to the predetermined rotational phase.

  According to the configuration of the second aspect, it is determined whether or not the rotational phase of the motor is at a predetermined rotational phase based on a change mode of the electrical angle count value that is referred to for switching the energized phase when the motor is driven. can do. Therefore, it is possible to determine whether or not the rotation phase of the motor is at a predetermined rotation phase without providing a new sensor or the like for monitoring the rotation phase of the motor, and a new sensor is provided. Therefore, it is possible to suppress an increase in cost and a complicated manufacturing process for attaching the sensor.

  More specifically, in a variable valve apparatus having an 8-pole 3-phase electrical angle counter as in the configuration of claim 3, the arrangement of magnetic poles at a portion corresponding to a predetermined rotational phase in the rotor May be different from the arrangement of the magnetic poles in other parts, and a configuration in which the arrangement of the eight magnetic poles is nonuniform in the part corresponding to the predetermined rotational phase may be adopted. By adopting such a configuration, the change mode of the electrical angle count value in a predetermined rotation phase becomes different from the change mode of the electrical angle count value in other rotation phases.

  According to a fourth aspect of the present invention, in the variable valve operating apparatus for an internal combustion engine according to the second or third aspect, when the rotational phase of the motor is at the predetermined rotational phase, the position count value changes. The gist is to switch the energized phase of the motor based on the above.

  The position count value is counted as a value corresponding to the amount of displacement from the reference position of the control shaft accompanying the rotation of the motor, and the value increases or decreases in proportion to the rotation angle of the motor. Therefore, if the change in the position count value is monitored, the change in the rotation phase of the motor can be estimated.

  In the variable valve operating apparatus according to claim 2 and claim 3, when the rotational phase of the motor is at a predetermined rotational phase, as described above, the electrical angle count value varies differently from the predetermined variation mode. It will change in the manner. For this reason, when the motor is in a predetermined rotational phase, the energized phase of the motor may not be switched accurately based on the electrical angle count value.

  On the other hand, in the configuration described in claim 4, when the rotational phase of the motor is at a predetermined rotational phase, the energized phase of the motor is switched based on the change of the position count value. According to such a configuration, the rotational phase of the motor is estimated based on the position count value that increases or decreases in proportion to the rotational angle of the motor as described above, and even when the motor is in the predetermined rotational phase. The energized phase of the motor can be accurately switched based on the estimated rotational phase.

  According to a fifth aspect of the present invention, in the variable valve operating apparatus for an internal combustion engine according to any one of the first to fourth aspects, the predetermined rotational phase includes an operating angle of the engine valve and an engine angle as the engine starts. A value of a position count value corresponding to the predetermined rotation phase is included in the values that can be taken by the position detection value when the lift amount is changed. Among the values that can be taken by the position detection value when the working angle and the lift amount are changed, the position detection value corresponding to the predetermined rotation phase is stored in advance as the reference value. The gist.

  When starting the engine, the position of the control shaft is set so that the operating angle and the lift amount are suitable for starting the engine, and the operating angle and the lift amount are suitable for idling operation as the engine starts. The control axis is displaced.

  According to the fifth aspect of the present invention, when the operating angle and the lift amount are changed as the engine is started, the position detection value corresponding to the predetermined rotational phase is included in the possible values of the position detection value. A predetermined rotation phase is set so that a value is included. Of the values that the position detection value can take when the operating angle and the lift amount are changed as the engine starts, the position detection value corresponding to a predetermined rotational phase is set in advance as a reference value to the variable valve operating device. I try to remember it. According to such a configuration, as the engine starts, the control shaft moves from the position corresponding to the operating angle and lift amount suitable for engine starting as described above to the position corresponding to the operating angle and lift amount suitable for idling operation. When the motor is displaced, it is determined that the rotational phase of the motor is at the predetermined rotational phase, and the learning process is executed. Therefore, according to the configuration described in claim 5, the position detection value can be quickly corrected as the engine is started, and the operating angle and lift amount of the engine valve can be appropriately set. Increase in quantity and deterioration of emissions can be suitably suppressed.

  The invention according to claim 6 is the variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 5, wherein the learning process is performed once after the internal combustion engine is started. The gist is to be executed on condition that it is not.

  The position detection value deviates from the value corresponding to the actual position of the control shaft, and a deviation occurs between the position of the control axis detected by the variable valve device and the actual position of the control axis. In addition, the engine is being stopped, in which the position count value is not counted by the variable valve operating device. In other words, the position detection value is not significantly displaced during engine operation in which the position count value is counted by the variable valve operating apparatus and the displacement of the control shaft is monitored. For this reason, as in the invention described in claim 6 above, a configuration is adopted in which the learning process is executed on the condition that the learning process has not been performed once since the internal combustion engine was started. The learning process may not be executed after the position detection value is corrected. By adopting such a configuration, it is possible to avoid repeating the learning process every time it is determined that the rotational phase of the motor is the predetermined rotational phase, even though the deviation of the position detection value is eliminated by the correction. As a result, it is possible to suppress an increase in calculation load accompanying execution of useless learning processing.

1 is a cross-sectional view showing a configuration of a valve mechanism for an internal combustion engine according to an embodiment of the present invention. The fracture | rupture perspective view which shows the internal structure of the lift amount change mechanism concerning the embodiment. The schematic diagram which shows schematic structure of the variable valve apparatus concerning the embodiment. The schematic diagram which shows the structure of the electrical angle sensor and position sensor of the variable valve apparatus concerning the embodiment. The timing chart which shows the transition aspect of the electrical angle count value and position count value in the variable valve apparatus concerning the embodiment. The table | surface which shows the relationship between the output signal and electrical angle count value of the electrical angle sensor concerning the embodiment. The table | surface which shows the relationship between the output signal of the position sensor concerning the embodiment, and a position count value. The timing chart which shows the change of the working angle at the time of engine starting of the internal combustion engine concerning the embodiment. The flowchart which shows the flow of a series of processes concerning the learning process of the embodiment. 6 is a timing chart showing the relationship between a change in position detection value and a change in electrical angle count value in the learning process according to the embodiment.

  Hereinafter, a variable valve operating apparatus for an internal combustion engine according to the present invention, an electronic control apparatus for an internal combustion engine that changes an operating angle and a lift amount of an intake valve, a lift amount changing mechanism that is mounted on the internal combustion engine, and the same are driven. An embodiment embodied as a variable valve mechanism comprising an actuator will be described with reference to FIGS.

  FIG. 1 is a cross-sectional view showing the configuration of the valve mechanism of the internal combustion engine according to the present embodiment. As shown in FIG. 1, the engine body 1 of this internal combustion engine is configured by combining a cylinder block 10 and a cylinder head 20. A piston 12 is slidably accommodated in a cylinder 11 formed in the cylinder block 10. A cylinder head 20 is assembled to the upper part of the cylinder block 10, and a combustion chamber 13 is defined by the inner peripheral surface of the cylinder 11, the upper surface of the piston 12, and the lower surface of the cylinder head 20.

  The cylinder head 20 is formed with an intake port 21 and an exhaust port 22 that communicate with the combustion chamber 13. The intake port 21 is connected to an intake manifold (not shown) and constitutes a part of the intake passage 30. Further, the exhaust port 22 is connected to an exhaust manifold (not shown) and constitutes a part of the exhaust passage 40.

  As shown in FIG. 1, the cylinder head 20 is provided with an intake valve 31 for connecting / blocking the intake passage 30 and the combustion chamber 13 and an exhaust valve 41 for connecting / blocking the exhaust passage 40 and the combustion chamber 13. It has been. A retainer 23 is fixed to each valve 31, 41, and a valve spring 24 is provided between the cylinder head 20 and the retainer 23. Thereby, each valve | bulb 31 and 41 is each urged | biased in the valve closing direction by the urging | biasing force of the valve spring 24, respectively.

  A lash adjuster 25 is provided in the cylinder head 20 corresponding to the valves 31 and 41. A rocker arm 26 is installed between the lash adjuster 25 and the valves 31 and 41. As shown in FIG. 1, one end of the rocker arm 26 is supported by the lash adjuster 25, and the other end is in contact with the base end portion of each of the valves 31 and 41.

  Further, the cylinder head 20 supports an intake camshaft 32 and an exhaust camshaft 42 that drive the valves 31 and 41, respectively, so as to be rotatable. An intake cam 32 a is formed on the intake cam shaft 32, and an exhaust cam 42 a is formed on the exhaust cam shaft 42.

  The outer peripheral surface of the exhaust cam 42 a is in contact with the roller 26 a of the rocker arm 26 that is in contact with the exhaust valve 41. As a result, when the exhaust camshaft 42 rotates during engine operation as indicated by an arrow in the upper right part of FIG. 1, the rocker arm 26 swings around the portion supported by the lash adjuster 25 by the action of the exhaust cam 42a. To do. As a result, the exhaust valve 41 is lifted in the valve opening direction by the rocker arm 26.

  On the other hand, a lift amount changing mechanism 300 is provided between the intake cam 32a and the rocker arm 26 in contact with the intake valve 31, as shown in the upper left part of FIG. The lift amount changing mechanism 300 includes an input arm 311 and an output arm 321, and the input arm 311 and the output arm 321 are supported so as to be swingable around a support pipe 330 fixed to the cylinder head 20. Yes. The rocker arm 26 is urged toward the output arm 321 by the urging force of the valve spring 24, and a roller 26 a provided at an intermediate portion of the rocker arm 26 is in contact with the outer peripheral surface of the output arm 321.

  Further, a convex portion 313 is provided on the outer peripheral surface of the lift amount changing mechanism 300, and this convex portion 313 is indicated by an arrow W <b> 1 in FIG. 1 by an urging force of a spring 50 fixed in the cylinder head 20. It is so energized. Accordingly, the lift amount changing mechanism 300 is urged in the direction indicated by the arrow W1 around the support pipe 330, and the roller 311a provided at the tip of the input arm 311 is in contact with the outer peripheral surface of the intake cam 32a. . Accordingly, when the intake cam 32a rotates during engine operation as indicated by an arrow at the upper center of FIG. 1, the lift amount changing mechanism 300 swings about the support pipe 330 by the action of the intake cam 32a. Then, by the action of the output arm 321, the rocker arm 26 swings with the portion supported by the lash adjuster 25 as a fulcrum. As a result, the intake valve 31 is lifted in the valve opening direction by the rocker arm 26.

  Further, a control shaft 340 is inserted into the support pipe 330 so as to be movable in the axial direction. In the lift amount changing mechanism 300, the relative phase difference between the input arm 311 and the output arm 321 around the support pipe 330, that is, the angle shown in FIG. 1, is obtained by displacing the control shaft 340 in the axial direction. θ can be changed.

  Next, the configuration of the lift amount changing mechanism 300 will be described in more detail with reference to FIG. FIG. 2 is a cutaway perspective view showing the internal structure of the lift amount changing mechanism 300. As shown in FIG. 2, a control shaft 340 is inserted into the support pipe 330 fixed to the cylinder head 20 so as to be movable in the axial direction. A cylindrical slider 350 is fitted on the support pipe 330 so as to be movable in the axial direction.

  A groove 353 extending along the circumferential direction is formed on the inner wall of the cylindrical slider 350. The groove 353 is fitted with a locking pin 341 having a base end inserted into a recess (not shown) formed in the control shaft 340. A long hole 331 extending in the axial direction is formed in the tube wall of the support pipe 330, and the locking pin 341 is locked to the groove 353 of the slider 350 through the long hole 331. As a result, the slider 350 freely rotates around the support pipe 330 and the control shaft 340 and moves in conjunction with the axial displacement of the control shaft 340.

  On the outer peripheral surface of the slider 350, a helical spline 351 is formed at the center thereof, and a helical spline 352 in which the helical spline 351 and the tooth trace are inclined in opposite directions is formed at both ends thereof. In FIG. 2, only the right side portion of the slider 350 is shown for convenience of explanation.

  As shown in FIG. 2, the slider 350 is externally fitted with an input unit 310 and a pair of output units 320 disposed so as to sandwich the input unit 310. A helical spline 312 is formed on the inner peripheral surface of the input unit 310, and the helical spline 312 meshes with the helical spline 351 of the slider 350. A pair of input arms 311 projecting in the radial direction is formed on the outer peripheral surface of the input unit 310, and a roller 311 a is rotatably supported between the pair of input arms 311.

  On the other hand, helical splines 322 are formed on the inner peripheral surfaces of the pair of output portions 320, and the helical splines 322 mesh with the helical splines 352 of the slider 350. Further, output arms 321 projecting in the radial direction are formed on the outer peripheral surface of the output unit 320, respectively.

  In the lift amount changing mechanism 300 formed in this way, when the control shaft 340 is displaced along the axial direction, the slider 350 is displaced in the axial direction in conjunction therewith. The helical splines 351 and 352 formed on the outer peripheral surface of the slider 350 have different streak travel directions, and mesh with the helical splines 312 and 322 formed on the inner peripheral surfaces of the input unit 310 and the output unit 320, respectively. Has been. Therefore, when the slider 350 is displaced in the axial direction, the input unit 310 and the output unit 320 rotate in opposite directions. As a result, the relative phase difference between the input arm 311 and the output arm 321 is changed, and the operating angle and lift amount of the intake valve 31 are changed.

  Specifically, when the control shaft 340 is displaced in the arrow Hi direction shown in FIG. 2, the slider 350 moves in the Hi direction together with the control shaft 340. Accordingly, the relative phase difference between the input arm 311 and the output arm 321, that is, the angle θ in FIG. 1 increases, and the working angle and lift amount of the intake valve 31 increase. On the other hand, when the control shaft 340 is displaced in the direction of the arrow Lo shown in FIG. 2, the relative phase difference between the input arm 311 and the output arm 321 decreases as the slider 350 moves in the Lo direction together with the control shaft 340. Thus, the operating angle and lift amount of the intake valve 31 are reduced.

In the internal combustion engine according to this embodiment, the control shaft 340 is displaced in the axial direction during engine operation, and the operating angle and the lift amount of the intake valve 31 are changed through the lift amount changing mechanism 300.
Next, the configuration of the actuator 200 that displaces the control shaft 340 in the axial direction will be described with reference to FIGS. 3 and 4. FIG. 3 is a schematic diagram showing a schematic configuration of a variable valve operating apparatus for an internal combustion engine according to the present embodiment, that is, a lift amount changing mechanism 300, an actuator 200 for driving the mechanism 200, and an electronic control unit 100 for controlling the actuator 200. FIG.

  As shown in FIG. 3, the actuator 200 includes a motor 210 including a magnet 211 and a stator 212, and a motion conversion mechanism 220 that converts the rotational motion of the motor 210 into a linear motion in the axial direction of the output shaft 221. It is configured to include. The tip of the control shaft 340 of the lift amount changing mechanism 300 is connected to the output shaft 221 of the actuator 200 and the fastener 222.

  Thus, by rotating the motor 210 within a predetermined range, for example, a rotation angle range (0 to 3600 °) for 10 rotations, the rotational motion of the motor 210 is converted into linear motion through the motion conversion mechanism 220, and the output shaft Then, it is input to the control shaft 340 via 221. As a result, the control shaft 340 is displaced in the axial direction, and the lift amount changing mechanism 300 is driven.

  Incidentally, when the motor 210 is rotated forward, the control shaft 340 is displaced in the direction of the arrow Hi in FIG. 3, and the relative phase difference between the input arm 311 and the output arm 321 of the lift amount changing mechanism 300 increases as described above. The operating angle and lift amount of the intake valve 31 increase. On the other hand, when the motor 210 is rotated in the reverse direction, the control shaft 340 is displaced in the direction of the arrow Lo in FIG. 3, the relative phase difference between the input arm 311 and the output arm 321 is reduced, and the working angle and lift amount of the intake valve 31 are reduced. Decrease.

  The displacement of the control shaft 340 in the direction of the arrow Hi and the displacement in the direction of the arrow Lo are regulated within a predetermined range by a stopper (not shown) provided on the control shaft 340, and this stopper serves as a cylinder head. The position that contacts a part of 20 is the movable limit position of the control shaft 340.

  As described above, in the internal combustion engine according to the present embodiment, the actuator 200 is driven to displace the control shaft 340 in the axial direction, whereby the operating angle and the lift amount of the intake valve 31 are changed in the axial direction of the control shaft 340. It changes to correspond to the position of.

  As shown on the left side of FIG. 3, the motor 210 that drives the actuator 200 includes a magnet 211 that is fixed to the outer peripheral surface of the motion conversion mechanism 220, and a stator 212 that is excited based on a drive command from the electronic control device 100. It is comprised including. A sensor plate 213 is fixed to the rear end of the motion conversion mechanism 220 as a rotor of an electric angle counter described later.

  As shown in FIG. 4, the sensor plate 213 includes an 8-pole multipole magnet 214 in which four N poles and four S poles are alternately arranged in a circle, and 24 N poles and 24 A 48-pole multipole magnet 215 in which the S poles are alternately arranged in a circle is fixed concentrically.

  As shown in FIG. 4, the 8-pole multi-pole magnet 214 has N poles and S poles alternately arranged every 45 ° in a portion that occupies three quarters of the entire circumference. . On the other hand, in the portion occupying the remaining quarter, that is, in the portion C surrounded by the broken line in FIG. 4, the ratio of the area of the N pole and the S pole is “1: 2”. Is set to a size corresponding to a rotation angle of 30 ° and the south pole of 60 °.

On the other hand, in the 48-pole multipole magnet 215, as shown in FIG. 4, the N pole and the S pole are alternately arranged every 7.5 ° uniformly over the entire circumference. .
As shown in FIGS. 3 and 4, electrical angle sensors S1, S2, and S3 are provided at portions that are opposed to the multipolar magnet 214 in the actuator 200 with a phase difference of 30 ° from each other. Position sensors S4 and S5 are provided at positions opposite to 215 with a phase shift of 3.75 ° from each other.

  Accordingly, when the sensor plate 213 rotates with the rotation of the motor 210, the N pole and the S pole alternately face each sensor S1 to S5, and each sensor S1 to S5 becomes the N pole. The corresponding high signal “H” and the low signal “L” corresponding to the S pole are alternately output.

  As shown in FIG. 3, these electric angle sensors S1, S2, S3 and position sensors S4, S5 are connected to an electronic control unit 100 that controls the internal combustion engine in an integrated manner, and these electric angle sensors S1, S2 , S3 and the pulse signals output from the position sensors S4, S5 are taken into the electronic control unit 100. The electronic control unit 100 controls the motor 210 of the actuator 200 based on these signals and controls each part of the internal combustion engine.

  The electronic control unit 100 includes various memories such as a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and an EEPROM which is a nonvolatile memory capable of rewriting stored data.

  In addition to the sensors S1 to S5, the electronic control unit 100 detects an accelerator position sensor 111 that detects the driver's accelerator operation amount ACCP, and an intake air amount GA that is taken into the combustion chamber 13 through the intake passage 30. An air flow meter 112, a crank position sensor 113 for detecting the engine rotational speed NE, a cam position sensor 114 for detecting the rotational phase of the intake camshaft 32, a water temperature sensor 115 for detecting the engine cooling water temperature THW, and the like are connected. In addition to the pulse signals from the electrical angle sensors S1, S2, S3 and the position sensors S4, S5, the electronic control device 100 receives signals from these various sensors 111-115.

  The electronic control unit 100 executes calculation related to control of the fuel injection amount and ignition timing based on the output signals of these various sensors 111 to 115, and the operating angle and lift amount of the intake valve 31 are suitable for the engine operating state. Therefore, drive control of the lift amount changing mechanism 300, that is, drive control of the motor 210 of the actuator 200 is executed.

  Hereinafter, drive control of the motor 210 will be described with reference to FIGS. As described above, the electrical angle sensors S1, S2, S3 are arranged with a phase difference of 30 ° from each other. Therefore, as shown in the upper part of FIG. 5, a pulse signal in which the high signal “H” and the low signal “L” are alternately switched from each of the electrical angle sensors S1, S2, S3 as the motor 210 rotates is a rotation angle. It is output in a state shifted by an amount corresponding to 30 °.

  The electronic control device 100 calculates the electrical angle count value Ce based on the output pattern of the pulse signal from each electrical angle sensor S1, S2, S3. Specifically, as shown in FIG. 6, the electrical angle count is based on which of the high signal “H” and the low signal “L” is output from each of the electrical angle sensors S1, S2, S3. The value Ce is set to any one of “0”, “1”, “2”, “3”, “4”, “5”. In the table of FIG. 6, when the motor 210 is rotating forward, the electrical angle count value Ce is “0” → “1” → “2” → “3” → “4” → “5” → “0”. On the other hand, the electric angle count value Ce is “5” → “4” → “3” → “2” → “1” → “0” → “ It is set to change in the reverse direction in the order of “5”.

  The values “0”, “1”, “2”, “3”, “4”, “5” of the electrical angle count value Ce correspond to the energization pattern to the energization phase of the motor 210. That is, in the present embodiment, the sensor plate 213 in which eight magnetic poles are arranged in a circle so that N poles and S poles are alternately arranged, and three electrical angle sensors S1, S2, and S3 are used. A pole three-phase electrical angle counter is configured. The rotation of the motor 210 is controlled by switching the energized phase of the motor 210 based on the electrical angle count value Ce counted by the electrical angle counter.

  On the other hand, the position sensors S4 and S5 are arranged with a phase difference of 3.75 ° as described above. Therefore, as the motor 210 rotates, the high signal “H” and the low signal “L” are alternately switched from the position sensors S4 and S5 every rotation angle of 7.5 ° as shown in the middle part of FIG. The pulse signals are output in a state of being shifted from each other by an amount corresponding to a rotation angle of 3.75 °.

  The electronic control unit 100 counts the position count value Cp based on the output pattern of the pulse signal from each position sensor S4, S5. Specifically, as shown in FIG. 7, whether the output signal of one of the position sensors S4 and S5 is the rising edge “↑” or the falling edge “↓”, and the output signal of the other sensor Depending on whether the signal is a high signal “H” or a low signal “L”, counting is performed by adding “+1” or “−1” to the position count value Cp. Thus, the position count value Cp counted based on the pulse signals of the position sensors S4 and S5 is added one by one when the motor 210 is rotating forward as shown in the lower part of FIG. When it is, it will be subtracted one by one.

  The position count value Cp is reset to “0” when the engine is stopped. Therefore, the position count value Cp is a value corresponding to the amount of change in the rotation angle of the motor 210 after the internal combustion engine is started, that is, the amount of displacement of the control shaft 340 after the engine is started. Further, the position count value Cp is sequentially counted as the motor 210 is driven and frequently rewritten, so that the position count value Cp is stored in the RAM of the electronic control unit 100.

  By the way, as described above, in the 8-pole multipole magnet 214, the N pole and the S pole correspond to the rotation angles of 30 ° and 60 ° in a part thereof (the portion C surrounded by the broken line in FIG. 3). The magnetic poles are non-uniformly arranged. Therefore, as shown in the upper part of FIG. 5, in the rotational phase corresponding to the part other than the part C, the high signal “H” and the low signal “L” each time the rotation angle of the motor 210 changes by 45 °. Are alternately switched, while in the rotational phase corresponding to the portion C, the high signal “H” is output only during the period corresponding to the rotational angle of 30 °, whereas the low signal “L” is rotated at the rotational angle of 60 °. It is output over a period corresponding to °°. Therefore, when the rotational phase of the motor 210 is at a predetermined rotational phase where the portion C of the sensor plate 213 passes through each electrical angle sensor S1, S2, S3, the electrical angle count value Ce as shown in the middle of FIG. Is different from the change mode of the electrical angle count value Ce in other rotation phases.

  Specifically, when the motor 210 is rotating forward, as shown in the middle part of FIG. 5, an electrical angle every time the rotation angle of the motor 210 changes by 15 ° at a rotation phase other than the predetermined rotation phase. A change in which the count value Ce increases one by one in the forward direction in the order of “0” → “1” → “2” → “3” → “4” → “5” → “0” is periodically repeated ( Variation A) in FIG. On the other hand, at the predetermined rotation phase, every time the rotation angle of the motor 210 changes by 30 °, the electrical angle count value Ce increases by 2 such as “0” → “2” → “4”. (Change mode B in FIG. 5). Further, when the rotation phase of the motor 210 becomes the predetermined rotation phase with the rotation of the motor 210 and the change mode of the electrical angle count value Ce is switched from the change mode A to the change mode B, the electrical angle count value Ce is “ It changes from “4” to “0” instead of “4” to “5”.

  Thus, when the rotational phase of the motor 210 is at the predetermined rotational phase where the portion C of the sensor plate 213 passes through the electrical angle sensors S1, S2, S3, the electrical angle count value Ce is different from the change mode A. It changes in change mode B. For this reason, when the rotational phase of the motor 210 is at the predetermined rotational phase, the energized phase of the motor 210 may not be switched accurately based on the value of the electrical angle count value Ce.

  Therefore, in the present embodiment, every time the rotation angle of the motor 210 changes by 3.75 ° in the predetermined rotation phase where the change mode of the electrical angle count value Ce is different from the change mode A. The energized phase is switched based on a change in the position count value Cp that changes one by one.

  Specifically, for example, when the motor 210 is rotated forward, when the electrical angle count value Ce changes to one on the positive rotation side every time the position count value Cp increases by four (for example, “3 ”→” 4 ”), the same energized phase is switched. On the other hand, when the motor 210 is reversely rotated, every time the position count value Cp decreases by four, the electrical angle count value Ce changes to a value on the reverse rotation side (for example, “4” → “3 ]) Switch the energized phase in the same way.

  If the change of the position count value Cp is monitored in this way and the energized phase is switched based on this, even if the change mode of the electrical angle count value Ce is different from the change mode A, the motor 210 can be appropriately controlled.

  The electronic control unit 100 counts the position count value Cp as the motor 210 is driven as described above, and calculates the position detection value Cs indicating the position of the control shaft 340 based on the position count value Cp. The position detection value Cs is calculated by adding a position count value Cp corresponding to the displacement amount of the control shaft 340 after starting the engine to a reference count value Ct which is a position detection value Cs at the end of the previous engine operation. . The reference count value Ct is stored in the EEPROM each time the engine operation ends.

  The electronic control unit 100 detects the position of the control shaft 340 based on the position detection value Cs thus calculated, and brings the position of the control shaft 340 closer to the position corresponding to the target operating angle and lift amount. The lift adjustment mechanism 300 is controlled by feedback control of the motor 210.

  By the way, if the control shaft 340 is displaced while the engine is stopped and the electronic control device 100 is not energized and the position count value Cp is not counted, the reference count value stored in the EEPROM is stored. The reference count value Ct does not correspond to the actual position of the control shaft 340 without being reflected in Ct. As a result, when the internal combustion engine is operated next, the position detection value Cs does not correspond to the actual position of the control shaft 340, and the operating angle and the lift amount cannot be controlled appropriately.

  The urging force of the valve spring 24 that urges the intake valve 31 in the valve closing direction is constantly acting on the control shaft 340 of the lift amount changing mechanism 300. Therefore, when the temperature of the lubricating oil is high and the friction in the lift amount changing mechanism 300 is reduced, or when the engine stop state continues for a long time, the control shaft 340 is actuated by the urging force of the valve spring 24. Further, the control shaft 340 may be displaced while the engine is stopped as described above, driven in the direction of decreasing the lift amount (Lo direction).

Therefore, in the internal combustion engine of the present embodiment, the learning process is executed when the engine is started to eliminate the deviation of the position detection value Cs.
In the internal combustion engine provided with the lift amount changing mechanism 300, as shown in FIG. 8, immediately after the starter is turned "ON" as the engine starts, the intake valve 31 of the intake valve 31 is improved in order to improve the intake air charging efficiency. The working angle is reduced. Then, the engine rotational speed NE rises to shift to idling operation, and the operating angle of the intake valve 31 is increased, and the operating angle of the intake valve 31 is set to an operating angle suitable for idling operation and normal engine operation. To improve the emission performance. FIG. 8 is a timing chart showing a control mode of the operating angle of the intake valve 31 when the engine is started.

  In the actuator 200 of the present embodiment, as the operating angle of the intake valve 31 for starting the engine increases, a sensor is set so that the rotational phase of the motor 210 becomes the predetermined rotational phase at point D in FIG. The positions of the multipolar magnet 214 and the electrical angle sensors S1, S2, S3 on the plate 213 are set.

  Further, it is detected when the rotation phase of the motor 210 becomes the predetermined rotation phase with the increase of the operating angle of the intake valve 31 for starting the engine, and the electrical angle count value Ce changes from “4” to “0”. The detected position value Cs is stored in advance in the electronic control unit 100 as the reference value X.

  Then, when the electrical angle count value Ce changes from “4” to “0” with an increase in the operating angle for starting the engine, the reference value X is compared with the actually calculated position detection value Cs. Then, the deviation of the position detection value Cs is determined, and a learning process for correcting the deviation of the position detection value Cs is executed.

Hereinafter, a series of processes of this learning process will be described in more detail with reference to FIG. FIG. 9 is a flowchart showing the flow of this series of processing.
This series of processing is repeatedly executed at a predetermined control cycle by the electronic control unit 100 during engine operation. When this series of processes is started, the electronic control unit 100 first determines whether or not the learning completion flag F is “1” in step S100 as shown in FIG. The learning completion flag F is a flag that is referred to in order to determine whether or not the execution of the learning process has been completed from when the internal combustion engine is started to the present, and when the execution of the learning process is completed. It is set to “1”. The learning completion flag F is reset to “0” when the engine is stopped, and is set to “0” when the engine start is started.

  If it is determined in step 100 that the learning completion flag F is not “1” (step S100: NO), that is, it is determined that the learning completion flag F is “0” and the learning process has not yet been completed. If so, the process proceeds to step S110.

  On the other hand, when it is determined in step S100 that the learning completion flag F is “1” (step S100: YES), that is, the learning process has been completed and the position detection value Cs has already been corrected. If it is determined, this process is temporarily terminated.

  In step S110, it is determined whether or not the electrical angle count value Ce has changed from “4” to “0”. When it is determined in step S110 that the electrical angle count value Ce has changed from “4” to “0” (step S110: YES), the change mode of the electrical angle count value Ce changes from the change mode A. Based on this, it is determined that the rotational phase of the motor 210 has reached the predetermined rotational phase, and the process proceeds to step S120.

  On the other hand, when it is determined in step S110 that the electrical angle count value Ce has not changed from “4” to “0” (step S110: NO), the rotational phase of the motor 210 is determined based on this. It is determined that the predetermined rotational phase has not been reached. In this case, the process is temporarily terminated as it is.

  In step S120, it is determined whether or not the position detection value Cs is equal to the reference value X. If it is determined in step S120 that the position detection value Cs is not equal to the reference value X (step S120: NO), based on this, it is determined that there is a deviation in the position detection value Cs, Proceed to step S130.

  In step S130, a value obtained by subtracting the position detection value Cs from the reference value X is calculated as a correction amount Y. In step S140, the correction amount Y is added to the position detection value Cs, and the value is added to a new position detection value. Set as Cs. By adding the correction amount Y in this way, the position detection value Cs is corrected so as to coincide with the reference value X.

  For example, as described above, when the control shaft 340 is displaced in the direction of reducing the operating angle and the lift amount of the intake valve 31 while the engine is stopped, the position detection value Cs becomes a value larger than the reference value X. . As a result, the correction amount Y calculated in step S130 becomes a negative value. In this case, the correction amount Y is added to the position detection value Cs in step S140, so that the position detection value Cs is corrected to decrease. It will be.

When the position detection value Cs is corrected so as to coincide with the reference value X in this way, the process proceeds to step S150, the learning completion flag F is set to “1”, and this series of processing is once ended.
On the other hand, when it is determined in step S120 that the position detection value Cs is equal to the reference value X (step S120: YES), based on this, it is determined that there is no deviation in the position detection value Cs. Then, step S130 and step S140 are skipped and the process proceeds to step S150. Then, the learning completion flag F is set to “1”, and this series of processing is once ended.

  As described above, in the internal combustion engine of the present embodiment, when the operating angle of the intake valve 31 is increased as the engine is started, the rotational phase of the motor 210 is set to a predetermined value based on the change mode of the electrical angle count value Ce. Monitor whether the rotation phase is reached. Then, when the rotational phase of the motor 210 becomes a predetermined rotational phase and the electrical angle count value Ce changes from “4” to “0” as shown in FIG. 10 (time t1 in FIG. 10), position detection is performed. A learning process for comparing the value Cs with the reference value X and correcting the position detection value Cs so as to coincide with the reference value X as indicated by an arrow is executed.

According to the embodiment described above, the following effects can be obtained.
(1) By comparing the position detection value Cs with the reference value X when it is determined that the rotation phase of the motor 210 is a predetermined rotation phase, the control shaft 340 is not displaced to the movable limit position, The amount of displacement of the position detection value Cs can be grasped. Then, by executing a learning process for correcting the position detection value Cs so as to coincide with the reference value X, the shift of the position detection value Cs can be eliminated. Therefore, unlike the conventional variable valve gear that performs the abutting learning in which it is inevitable that the control shaft 340 collides with other members as the learning is performed, the control shaft 340 collides with the other members. The learning process can be executed without any problem, and a decrease in durability of the actuator 200 or the lift amount changing mechanism 300 can be suppressed.

  Unlike conventional variable valve gears that perform abutment learning in which execution opportunities are limited because the working angle and lift amount must be maximized or minimized, the rotational phase of the motor 210 is a predetermined rotational phase. Learning processing can be performed when As a result, the number of opportunities for executing the learning process during engine operation is increased compared to a conventional variable valve device that performs abutment learning, and the deviation of the position detection value Cs can be quickly eliminated.

  In short, while suppressing a decrease in durability of the actuator 200 and the lift amount changing mechanism 300, the position detection value Cs can be corrected quickly to suppress an increase in fuel consumption and a deterioration in emissions.

  (2) Whether or not the rotational phase of the motor 210 is in a predetermined rotational phase is determined based on the change mode of the electrical angle count value Ce that is referred to in order to switch the energized phase when the motor 210 is driven. Therefore, it is possible to determine whether or not the rotational phase of the motor 210 is at a predetermined rotational phase without providing a new sensor or the like for monitoring the rotational phase of the motor 210. The increase in cost due to the provision and the complication of the manufacturing process for the attachment of the sensor can be suppressed.

  (3) The position count value Cp is counted as a value corresponding to the amount of displacement from the reference position of the control shaft 340 accompanying the rotation of the motor 210, and the value increases or decreases in proportion to the rotation angle of the motor 210. Therefore, if the change in the position count value Cp is monitored, the change in the rotation phase of the motor 210 can be estimated.

  In the internal combustion engine of the above-described embodiment, when the rotational phase of the motor 210 is at a predetermined rotational phase, the electrical angle count value Ce changes in a changing manner different from the predetermined changing manner. The energized phase of the motor 210 cannot be switched accurately based on the count value Ce. On the other hand, in the internal combustion engine of the above-described embodiment, when the rotational phase of the motor 210 is at a predetermined rotational phase and the energized phase of the motor 210 cannot be accurately switched based on the electrical angle count value Ce, the position count value The energized phase of the motor 210 is switched based on the change in Cp. Therefore, even when the motor 210 is in a predetermined rotational phase, the rotational phase of the motor 210 is estimated based on the change in the position count value Cp, and the energized phase of the motor 210 is accurately determined based on the estimated rotational phase. You can switch to

  (4) The value of the position detection value Cs corresponding to a predetermined rotation phase is included in the values that the position detection value Cs can take when the operating angle and lift amount of the intake valve 31 are changed as the engine starts. As described above, the positions of the multipolar magnet 214 and the electrical angle sensors S1, S2, S3 on the sensor plate 213 of the actuator 200 are set. Of the possible values of the position detection value Cs when the operating angle and the lift amount are changed as the engine starts, the position detection value Cs calculated when the predetermined rotational phase is reached is used as a reference value. X is stored in the electronic control device 100 in advance. Therefore, the control shaft 340 is displaced from the position corresponding to the operating angle and the lift amount suitable for engine starting to the position corresponding to the operating angle and the lift amount suitable for idling operation and normal engine operation with the execution of the engine start. When this is done, it is determined that the rotational phase of the motor 210 is at a predetermined rotational phase. As a result, the deviation of the position detection value Cs can be quickly eliminated as the engine is started, and the operating angle and lift amount of the intake valve 31 can be set appropriately, which suitably increases fuel consumption and worsens emissions. Can be suppressed.

  (5) The position detection value Cs deviates from a value corresponding to the actual position of the control shaft 340, and between the position of the control axis 340 detected by the electronic control device 100 and the actual position of the control shaft 340. The deviation occurs when the engine is stopped, where the position count value Cp is not counted. That is, during the engine operation in which the position count value Cp is counted by the electronic control unit 100 and the displacement of the control shaft 340 is monitored, the position detection value Cs is not likely to be shifted.

  On the other hand, in the above embodiment, it is determined whether or not the learning completion flag F is “1” in step S100, and when the learning completion flag F is not “1”, that is, after the internal combustion engine is started. The learning process is executed only when the learning process has not yet been completed. In short, in the above-described embodiment, a configuration is adopted in which the learning process is executed on the condition that the learning process has not been performed even once the internal combustion engine has been started, and the learning process is executed to determine the position detection value Cs. After the deviation is resolved, the learning process is not executed. Therefore, it is possible to avoid repeating the useless learning process every time it is determined that the rotational phase of the motor 210 is a predetermined rotational phase, even though there is no deviation in the position detection value Cs. It is possible to suppress an increase in calculation load accompanying execution of useless learning processing.

In addition, the said embodiment can also be implemented with the following forms which changed this suitably.
・ A configuration has been shown in which the learning process is executed only once after the engine is started on the condition that the learning process has not been completed since the internal combustion engine was started. it can.

In addition, the learning process may be executed each time the rotation phase of the motor 210 becomes a predetermined rotation phase without providing an execution condition.
In the above-described embodiment, the configuration in which the position detection value Cs is corrected so as to coincide with the reference value X in the learning process is shown. However, the configuration in which the position detection value Cs is corrected to approach the reference value X is shown. If so, at least the deviation of the position detection value Cs can be reduced, and an increase in fuel consumption and emission can be suppressed. That is, the aspect of the learning process according to the present invention is not limited to the case where the position detection value Cs matches the reference value X, and if the position detection value Cs can be brought close to the reference value X, The contents can be changed as appropriate.

  A configuration in which the positions of the multipolar magnet 214 and the electrical angle sensors S1, S2, S3 on the sensor plate 213 of the actuator 200 are set so that the learning process is executed when the control shaft 340 is displaced as the engine starts. Although shown, the present invention is not limited to such a configuration. That is, a predetermined rotational phase in which the change mode of the electrical angle count value Ce is changed so that the learning process can be executed during engine operation, and the position detection value Cs corresponding to the predetermined rotational phase is set. It only has to be stored in advance as the reference value X.

  A configuration is shown in which when the rotational phase of the motor 210 is at a predetermined rotational phase, the rotational phase of the motor 210 is estimated based on a change in the position count value Cp, and the energized phase of the motor 210 is switched based on this. On the other hand, a phase detection means for detecting the rotational phase of the motor 210 is provided separately from the electrical angle counter. When the rotational phase of the motor 210 is at a predetermined rotational phase, the rotational phase detected by this phase detection means is set. A configuration in which the energized phase is switched based on the above can also be employed.

  As described above, in the multipolar magnet 214 in the above embodiment, the N pole and the S pole correspond to the rotation angles of 30 ° and 60 ° in a part (portion C surrounded by a broken line in FIG. 3). The magnetic poles are non-uniformly arranged. This is because the change mode of the electrical angle count value Ce is changed in accordance with the change of the rotation phase of the motor 210, and the rotation phase of the motor 210 becomes a predetermined rotation phase based on the change mode of the electrical angle count value Ce. It is an example of the structure of the rotation phase determination means for determining. Therefore, the configuration of the multipolar magnet 214, the positions of the electrical angle sensors S1, S2, S3, etc., can be used as long as the change mode of the electrical angle count value Ce can be changed according to the change in the rotation phase of the motor 210. Can be appropriately changed.

  -Moreover, in the said embodiment, as a rotation phase determination means, the output mode of the pulse signal of electrical angle sensor S1, S2, S3 for changing the energization phase of the motor 210 is changed according to a rotation phase, A configuration is shown in which it is determined that the rotational phase of the motor 210 is at a predetermined rotational phase based on the change in the change mode of the electrical angle count value Ce. On the other hand, the configuration of the rotational phase determination means can be changed as appropriate as long as it can determine that the rotational phase of the motor 210 is at a predetermined rotational phase. For example, a sensor that outputs a signal when the rotational phase of the motor 210 is at a predetermined rotational phase is newly provided, and the rotational phase of the motor 210 is at the predetermined rotational phase based on the signal output from this sensor. It is possible to employ a configuration for determining.

-Although the structure which performs a learning process immediately after an engine start was shown, the structure which performs a learning process not only immediately after an engine start but an engine operation | movement can also be employ | adopted.
In addition, according to the present invention, since learning can be executed every time the rotational phase of the motor 210 reaches a predetermined rotational phase, the learning process is executed both immediately after engine startup and during engine operation. Also good. In this case, there are a plurality of reference values X corresponding to the rotation amount (first rotation, second rotation,...) Of the motor 210 corresponding to the predetermined rotation phase. It becomes. In this case, the position detection value Cs may be corrected so as to coincide with the corresponding rotation amount reference value X in the learning process.

  A configuration in which the position count value Cp is counted based on the pulse signals output from the position sensors S4 and S5 provided with the phases shifted is shown. On the other hand, if the position count value Cp corresponding to the amount of displacement of the control shaft 340 from the reference position can be counted, the configuration of the position sensor can be changed as appropriate. For example, the attachment positions of the position sensors S4 and S5, the number of position sensors, the number of magnetic poles of the multipolar magnet 215, and the like can be changed.

  -Although the structure which applies this invention as a variable valve apparatus of an internal combustion engine provided with the lift amount change mechanism 300 which changes the working angle and lift amount of the intake valve 31 was shown, this invention is the working angle and lift of the exhaust valve 41. The present invention can also be applied to an internal combustion engine including a lift amount changing mechanism that changes the amount.

DESCRIPTION OF SYMBOLS 1 ... Engine main body, 10 ... Cylinder block, 11 ... Cylinder, 12 ... Piston, 13 ... Combustion chamber, 20 ... Cylinder head, 21 ... Intake port, 22 ... Exhaust port, 23 ... Retainer, 24 ... Spring, 25 ... Rush adjuster , 26 ... Rocker arm, 26a ... Roller, 30 ... Intake passage, 31 ... Intake valve, 32 ... Intake camshaft, 32a ... Intake cam, 40 ... Exhaust passage, 41 ... Exhaust valve, 42 ... Exhaust camshaft, 42a ... Exhaust cam , 50 ... spring, 100 ... electronic control device, 111 ... accelerator position sensor, 112 ... air flow meter, 113 ... crank position sensor, 114 ... cam position sensor, 115 ... water temperature sensor, 200 ... actuator, 210 ... motor, 211 ... magnet 212 ... Stator, 213 ... Sensor 214 ... multipolar magnet, 215 ... multipolar magnet, 220 ... motion conversion mechanism, 221 ... output shaft, 222 ... fastener, 300 ... lift amount changing mechanism, 310 ... input unit, 311 ... input arm, 311a ... Roller, 312 ... Helical spline, 313 ... Protruding part, 320 ... Output part, 321 ... Output arm, 322 ... Helical spline, 330 ... Support pipe, 331 ... Long hole, 340 ... Control shaft, 341 ... Locking pin, 350 ... Slider, 351, helical spline, 352, helical spline, 353, groove, S1, S2, S3, electrical angle sensor, S4, S5, position sensor.

Claims (6)

A lift amount changing mechanism that changes the working angle and lift amount of the engine valve corresponding to the position of the control shaft in the axial direction, and converting the rotational motion of the motor into the linear motion of the control shaft to make the control shaft axial A position count corresponding to the amount of displacement of the control shaft from the reference position based on the pulse signal output from the position sensor, the actuator being displaced and a position sensor that outputs a pulse signal as the motor rotates. A position detection value indicating the position of the control shaft is calculated based on the position count value, and the motor is driven so that the position detection value approaches a value corresponding to the target operating angle and lift amount. In a variable valve operating apparatus for an internal combustion engine,
Rotation phase determination means for determining that the motor is in a predetermined rotation phase is provided, a position detection value corresponding to the predetermined rotation phase is stored in advance as a reference value, and the motor is set to the predetermined rotation phase. A variable valve operating apparatus for an internal combustion engine, which performs a learning process for correcting the position detection value so as to approach the reference value when it is determined that the position detection value is present. The variable valve operating apparatus for an internal combustion engine according to claim 1,
The rotational phase determination means includes an electrical angle sensor that outputs a pulse signal along with the rotation of the motor to generate an electrical angle count value that is referred to when switching the energized phase of the motor when the motor is driven. When the motor is in a rotation phase other than the predetermined rotation phase, the electrical angle count value periodically changes in a predetermined change mode with the rotation of the motor, while the motor is in the predetermined rotation phase. Sometimes, the electric angle count value is configured to change in a change mode different from the predetermined change mode as the motor rotates.
It is determined that the rotational phase of the motor is the predetermined rotational phase based on a change mode of the electrical angle count value being different from the predetermined change mode. apparatus. The variable valve operating apparatus for an internal combustion engine according to claim 2,
The rotational phase determining means includes a rotor in which eight magnetic poles are arranged in a circle so that N poles and S poles are alternately arranged, and three rotors provided with a phase shift at positions that can face the magnetic poles. An 8-pole 3-phase electrical angle counter configured to include the electrical angle sensor;
The variable valve operating apparatus for an internal combustion engine, wherein the arrangement of the eight magnetic poles in the rotor is made nonuniform in a portion corresponding to the predetermined rotational phase. The variable valve operating apparatus for an internal combustion engine according to claim 2 or 3,
The variable valve operating apparatus for an internal combustion engine, wherein when the rotational phase of the motor is at the predetermined rotational phase, the energized phase of the motor is switched based on a change in the position count value. The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 4,
The predetermined rotational phase is a position detection value corresponding to the predetermined rotational phase among the possible values of the position detection value when the operating angle and lift amount of the engine valve are changed as the engine starts. Is set to include a value,
Of the values that the position detection value can take when the operating angle and lift amount of the engine valve are changed as the engine starts, the value of the position detection value corresponding to the predetermined rotation phase is used as the reference value. A variable valve operating apparatus for an internal combustion engine, which is stored in advance. The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 5,
The variable valve operating system for an internal combustion engine, wherein the learning process is executed on condition that the learning process has never been performed since the internal combustion engine was started.

Images