JP2012189024A - Control device of lift quantity variable mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a lift quantity variable mechanism that can change a maximum lift quantity of an intake valve to a proper quantity corresponding to an engine operation state.SOLUTION: The electronic control device 50 of the lift quantity variable mechanism 12 includes a shaft sensor 28 for detecting a position of a control shaft 14 by detecting a target 30 arranged on the control shaft 14, and an intake pressure sensor 130 for detecting intake pressure in an intake passage. The electronic control device 50 reads in the position of the control shaft 14 calculated based on an output value of a rotation quantity sensor 26 as a specific position sensor value when the target 30 comes to a predetermined specific position in response to the movement of the control shaft 14, and calculates a correction quantity for correcting an actual position of the control shaft 14 based on a difference between the specific position and specific position sensor value. Correction processing is also performed for further correcting the correction quantity for correcting the actual position of the control shaft 14 in response to a separation degree between the intake pressure and estimate intake pressure in the same engine operation state in a predetermined engine operation state.

Description

  The present invention relates to a control device for a lift amount variable mechanism that changes a maximum lift amount of an intake valve.

  As described in Patent Document 1, there is known a variable lift amount mechanism that changes a maximum lift amount of an intake valve in accordance with an engine operating state. This variable lift amount mechanism changes the maximum lift amount of the intake valve when the control shaft is driven by the motor, and the position of the control shaft is determined based on the output value of the rotation amount sensor that detects the rotation amount of the motor. Is calculated. Based on the calculated position of the control shaft, variable control of the maximum lift amount is performed.

Here, if the position of the control axis recognized by the control device is deviated from the actual position of the control axis, variable control of the maximum lift amount cannot be performed with high accuracy.
Therefore, for example, as described in Patent Document 2, not only the rotation amount of the motor but also a position sensor for detecting the position of the control shaft by detecting a detection portion provided on the control shaft is separately provided. Then, by combining the position detection of the control shaft based on the detection value of the position sensor and the position detection of the control shaft based on the output value of the rotation amount sensor, the control shaft position recognized by the control device and Deviation from the actual control axis position can be suppressed to some extent.

JP 2010-180865 A JP 2009-197766 A

  However, strictly speaking, due to the dimensional error of the member to which the position sensor is mounted, the mounting error of the position sensor, the variation in the output characteristics of the sensor itself, or the dimensional error or mounting error of the detection part provided on the control shaft, The position of the control axis detected by the position sensor does not necessarily coincide with the actual position. If a deviation occurs between the control axis position recognized by the control device and the actual control axis position due to such error factors, the target value and actual value of the maximum lift amount set based on the engine operating state Therefore, the maximum lift amount may not be changed to an appropriate amount according to the engine operating state.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a control device for a variable lift amount mechanism that can change the maximum lift amount of an intake valve to an appropriate amount according to the engine operating state. There is to do.

In the following, means for achieving the above object and its effects are described.
According to the first aspect of the present invention, a lift amount variable mechanism that changes the maximum lift amount of the intake valve to an amount corresponding to the engine operating state by driving a control shaft by a motor, and a rotation that detects the rotation amount of the motor. A control device for a variable lift amount mechanism that calculates a position of the control shaft based on an output value of a quantity sensor, the position detecting the position of the control shaft by detecting a detection portion provided on the control shaft A sensor and an intake pressure sensor for detecting an intake pressure in the intake passage, and an output value of the rotation amount sensor when the detection portion comes to a predetermined specific position as the control shaft moves. The position of the control axis calculated based on the value is read as a specific position sensor value, and a correction amount for correcting the actual position of the control axis is calculated based on a deviation between the specific position and the specific position sensor value. Running out process, in certain engine operating conditions, as its gist to perform a correction process for correcting the correction amount according to the degree of deviation of the intake pressure and the estimated intake pressure at the same engine operating state.

  According to this configuration, the correction amount for correcting the actual position of the control axis is calculated based on the difference between the specific position of the control axis and the specific position sensor value. Thereby, the shift | offset | difference of the position of the control axis which a control apparatus recognizes and the position of an actual control axis is suppressed to some extent.

  On the other hand, the correction amount calculated based on the detection of the sensor includes the influence of the error factors described above. Therefore, in the same configuration, the above correction process is further executed in order to suppress the influence of the error factors described above.

  That is, as the maximum lift amount of the intake valve decreases, the opening area of the intake port decreases, so that the amount of intake air that passes through the intake valve and flows into the combustion chamber decreases. Therefore, as the maximum lift amount decreases, the intake pressure, which is the pressure in the intake passage, increases (approaching atmospheric pressure, the negative pressure decreases). Therefore, there is a difference between the position of the control shaft recognized by the control device and the actual position of the control shaft (the actual position of the control shaft), and the actual maximum lift amount of the intake valve is smaller than the target value. Sometimes, a divergence occurs between the estimated intake pressure estimated from the engine operating state and the actual intake pressure. Here, the actual intake pressure changes according to the actual control shaft position (actual maximum lift amount), and the estimated intake pressure is the control shaft position recognized by the control device (control device). Is a value that is changed according to the maximum lift amount recognized by For this reason, the degree of deviation between the actual intake pressure and the estimated intake pressure depends on the amount of deviation between the position of the control axis recognized by the control device and the position of the actual control axis.

  Therefore, in this configuration, the correction amount is corrected according to the degree of deviation between the intake pressure and the estimated intake pressure in the same engine operating state through the execution of the above correction process, and thereby the influence of the above-described error factors. Is suitably suppressed. Therefore, according to this configuration, it is possible to more appropriately suppress the deviation between the position of the control shaft recognized by the control device and the position of the actual control shaft, and the maximum lift amount of the intake valve is set according to the engine operating state. It will be possible to change to an appropriate amount.

  According to a second aspect of the present invention, in the control device for a variable lift amount according to the first aspect, when the intake pressure is higher than the estimated intake pressure, the difference between the estimated intake pressure and the intake pressure is determined. The gist is to correct the correction amount so that the maximum lift amount increases as the degree increases.

  In the control device for the variable lift amount mechanism according to claim 1 or 2, when the intake air pressure is lower than the estimated intake air pressure, the estimated intake air pressure and the intake air pressure are controlled. The gist is to correct the correction amount so that the maximum lift amount becomes smaller as the degree of deviation from the atmospheric pressure increases.

  As described above, the smaller the maximum lift amount of the intake valve, the higher the intake pressure (approaching atmospheric pressure, the negative pressure decreases). Therefore, when the actual intake pressure is higher than the estimated intake pressure, the actual maximum lift amount is smaller than the maximum lift recognized by the control device. Conversely, when the actual intake pressure is lower than the estimated intake pressure, the actual maximum lift amount is larger than the maximum lift recognized by the control device.

Therefore, when the correction amount is corrected according to the degree of deviation, the correction amount can be appropriately corrected by adopting the configuration described in claim 2 or claim 3.
According to a fourth aspect of the present invention, in the control device for a variable lift amount mechanism according to any one of the first to third aspects, the correction processing is performed in an engine operation state in which the maximum lift amount becomes smaller than a predetermined value. It is the gist of what is done at the time.

  The difference between the maximum lift recognized by the control device and the actual maximum lift amount, that is, the degree of deviation between the actual intake pressure and the estimated intake pressure tends to increase as the maximum lift amount of the intake valve decreases. Therefore, the deviation between the maximum lift recognized by the control device and the actual maximum lift amount is more reflected in the degree of deviation as the maximum lift amount is smaller. Therefore, in the same configuration, the above correction process is performed when the engine is in an engine operating state in which the maximum lift amount is smaller than a predetermined value, whereby the correction amount can be corrected with high accuracy.

According to a fifth aspect of the present invention, in the control device for a variable lift amount mechanism according to any one of the first to fourth aspects, the rotation amount sensor is a relative position sensor that detects a relative movement amount of a detection target. The calculation of the position of the control shaft based on the output value of the rotation amount sensor is performed by calculating a relative movement amount from a predetermined reference position of the control shaft,
The gist of the calculation process is that it is executed on the condition that learning of the reference position is completed.

  According to this configuration, the specific position sensor value is read after the accuracy of the position of the control shaft calculated based on the output value of the rotation amount sensor is suitably ensured. Therefore, the accuracy of the correction amount of the control axis calculated based on the difference between the specific position and the specific position sensor value can be improved.

FIG. 3 is a schematic diagram showing a structure of a lift variable mechanism to which the control device according to the present invention is embodied, to which the control device is applied. The enlarged view of a shaft sensor. The graph which shows the relationship between a lift amount and the output of a shaft sensor. The flowchart which shows the procedure of the correction process of a target operating angle. The timing chart which shows the setting aspect of correction amount.

Hereinafter, an embodiment in which a control device for a variable lift mechanism according to the present invention is embodied will be described with reference to FIGS.
As shown in FIG. 1, in the present embodiment, a lift variable mechanism 12 that continuously varies the maximum lift VL and the working angle INCAM of the intake valve 10 is provided for an internal combustion engine (not shown). . The working angle of the intake valve is a value corresponding to the valve opening period of the intake valve.

Since the detailed structure of the lift amount variable mechanism 12 is described in, for example, Japanese Patent Application Laid-Open No. 2010-180865, for example, only the outline will be described below.
The lift amount variable mechanism 12 includes a control shaft 14 and an actuator 16 that drives the control shaft 14 in the axial direction. The actuator 16 is provided with a motor as a power source and a conversion mechanism for converting the rotational movement of the motor into a linear movement to reciprocate the control shaft 14. The control shaft 14 and the output shaft 16 </ b> A of the actuator 16 are connected via a fastening member 18.

  The control shaft 14 is provided with a roller arm 20 and a pair of swing cams 22 located on both sides of the roller arm 20. A cam of an intake camshaft (not shown) is in contact with the roller of the roller arm 20, and when the intake camshaft rotates, the roller arm 20 is swung. 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, thereby opening 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 that meshes with the helical spline is disposed 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 phase 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 swing range of the swing cam 22 changes as the intake camshaft rotates, so that the maximum lift amount VL and the working angle INCAM of the intake valve 10 change synchronously.

  As described above, in the variable lift amount mechanism 12, the actuator 16 moves the control shaft 14 in one direction (for example, the left direction in FIG. 1), thereby continuously increasing the working angle INCAM and the maximum lift amount VL of the intake valve 10. Reduce to. On the other hand, both the operating angle INCAM and the maximum lift amount VL 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).

  The actuator 16 is provided with a rotation amount sensor 26 for detecting the rotation amount of the motor. A shaft sensor 28 as a position sensor for detecting the position of the control shaft 14 is installed in the vicinity of the control shaft 14. The shaft sensor 28 detects the position of the target 30 (detection site) provided on the control shaft 14 in a non-contact manner.

  The motor of the actuator 16, the rotation amount sensor 26, and the shaft sensor 28 are connected to the electronic control unit 50. Further, the electronic control unit 50 includes an engine speed NE of the internal combustion engine detected by the crank angle sensor 100, an intake air amount QA of the internal combustion engine detected by the air flow meter 110, and a throttle valve detected by the throttle sensor 120. The opening (throttle opening) TA and the intake pressure PM detected by the intake pressure sensor 130 are input.

As shown in FIG. 2, the shaft sensor 28 includes three sensor elements 28A, 28B, and 28C such as Hall elements.
By performing predetermined signal processing on the output waveforms of the sensor elements 28A, 28B, and 28C when the target 30 moves under the shaft sensor 28, three edge outputs are obtained as shown in the lower part of FIG. can get. In this way, the shaft sensor 28 generates an edge output when the target 30 comes to a specific position.

  By further performing signal processing on the lower edge output of FIG. 3, a stepped output as shown in the upper stage of FIG. 3 is obtained. According to this step-like output, when an edge output is generated from the shaft sensor 28, it can be determined which of the edge numbers 1 to 3 is the edge output.

  On the other hand, the rotation amount sensor 26 outputs a continuous signal proportional to the rotation amount of the motor of the actuator 16. Further, as the rotation amount sensor 26, a relative position sensor for detecting the relative movement amount of the detection target is employed.

  The change in the actual operating angle INCAM of the intake valve 10 is proportional to the axial position of the control shaft 14, and the axial position of the control shaft 14 is proportional to the rotation amount of the motor of the actuator 16. Therefore, the electronic control unit 50 learns a predetermined reference position F of the control shaft 14 based on the output signal of the rotation amount sensor 26 when the control shaft 14 is moved to the movable limit position. Then, the relative movement amount of the control shaft 14 from the reference position F is detected by the output signal of the rotation amount sensor 26, thereby detecting the position of the control shaft 14. In this way, the electronic control unit 50 recognizes the position of the control shaft 14, the maximum lift amount VL, and the operating angle INCAM.

  In the internal combustion engine including the variable lift amount mechanism 12, the intake air amount can be controlled regardless of the throttle valve by changing the maximum lift amount VL of the intake valve 10. In this case, the electronic control unit 50 sets the target operating angle INCAMp of the intake valve 10 in accordance with the engine operating state in order to control the intake air amount. Then, the operating angle INCAM of the intake valve 10 is grasped based on the output of the rotation amount sensor 26, and drive control of the actuator 16 is performed so that the operating angle INCAM coincides with the target operating angle INCAMp.

  In the present embodiment, the target operating angle INCAMp is calculated when the variable lift amount mechanism 12 is controlled. However, in the variable lift amount mechanism 12, the operating angle and the maximum lift amount are synchronized as described above. Change. Accordingly, the target value of the maximum lift amount VL may be calculated instead of the target operating angle INCAMp, and the lift amount variable mechanism 12 may be controlled based on this target value.

  As shown in FIG. 3, the shaft sensor 28 generates an edge output when the target 30 comes to a predetermined position, that is, when the control shaft 14 comes to a predetermined specific position. For example, when the maximum lift amount VL is gradually increased and the control shaft 14 passes the first specific position C, an edge output is generated and the edge number is changed from “0” to “1”. The When the control shaft 14 passes the next specific position B, an edge output is issued again and the edge number is changed from “1” to “2”. When the control shaft 14 passes the next specific position A, an edge output is issued again, and the edge number is changed from “2” to “3”. As described above, since the edge output is generated when the control shaft 14 reaches the predetermined specific position, the operating angle of the intake valve 10 when the shaft sensor 28 generates the edge output is the specific position of the control shaft 14. Correspondingly determined. For example, when the specific position C corresponds to the operating angle 150 ° CA, the specific position B corresponds to the operating angle 200 ° CA, and the specific position A corresponds to the operating angle 240 ° CA, the operating angle is 150 ° CA, An edge output is emitted from the shaft sensor 28 every time 200 ° CA and 40 ° CA are reached.

  Therefore, in the present embodiment, the value of the operating angle at the position of the control shaft 14 where the edge output should be emitted from the shaft sensor 28 (hereinafter referred to as a reference operating angle, for example, the above 150 ° CA, 200 ° CA, 240 ° CA). (Corresponding to the reference working angle) is stored in the electronic control device 50 in advance. Then, the operating angle INCAM when the edge number is changed is read from the rotation amount sensor 26 and compared with the reference operating angle INCAMb at that time. When there is a deviation amount Z between the working angle INCAM read when the edge output is generated and the reference working angle INCAMb, the electronic control unit 50 recognizes the position of the control shaft 14 currently recognized. And the actual position of the control shaft 14 are determined to be shifted, and processing for suppressing the shift is performed.

  Hereinafter, a process for correcting the target operating angle INCAMp so as to suppress the deviation will be described with reference to FIGS. This process is executed on the condition that the learning of the reference position F described above has been completed.

  When this process is started, it is first determined whether a detection signal is output from the shaft sensor 28, that is, whether an edge output is generated from the shaft sensor 28 (S100). When the detection signal is output (S100: YES), the current operating angle INCAM detected by the rotation amount sensor 26 is read (S110). The working angle INCAM read in step S110 corresponds to the specific position sensor value.

Next, the reference working angle INCAMb corresponding to the current edge output is subtracted from the current working angle INCAM to calculate the shift amount Z (S120).
For example, when the current working angle INCAM is “210 ° CA” and the reference working angle INCAMb corresponding to the current edge output is “240 ° CA”, “−30 ° CA” is calculated as the shift amount Z. . In this case, the current maximum lift amount VL is deviated from the maximum lift amount VL recognized by the electronic control unit 50 in a direction to be reduced by 30 ° CA in terms of operating angle. In other words, with respect to the position of the control shaft 14 recognized by the electronic control unit 50, the current actual position of the control shaft 14 is such that the maximum lift amount VL is reduced by 30 ° CA in terms of operating angle. It will be shifted.

  Next, a correction amount H corresponding to the shift amount Z is calculated (S130). The correction amount H is a value for correcting the target working angle INCAMp. When the target working angle INCAMp is changed in accordance with the shift amount Z, the control shaft 14 is corrected with respect to the target working angle INCAMp before correction. The actual position of the control shaft 14 is corrected by changing the position. That is, the actual position of the control shaft 14 is corrected by the correction amount H.

  Here, the position detection accuracy of the shaft sensor 28 is not so high, and when the edge output generation timing changes, the reading timing of the specific position sensor value also changes in accordance with the change. Accordingly, the reliability of the deviation amount Z is not so high, and if the deviation amount Z is set as it is as the correction amount H, there is a possibility of overcorrection that causes various inconveniences in some cases. Therefore, in this embodiment, the absolute value of the correction amount H is variably set so that the absolute value of the correction amount H increases as the absolute value of the shift amount Z increases. However, the absolute value of the correction amount H is larger than the absolute value of the shift amount Z. I try to make it smaller. For example, when the deviation amount Z is “−30 ° CA”, the correction amount H is “+15”, and when the deviation amount Z is “−20 ° CA”, the deviation amount H is “+5”. When the amount Z is “−19 ° CA”, the correction amount H is set to “0”.

  Incidentally, for example, the current working angle INCAM is “210 ° CA”, the reference working angle INCAMb corresponding to the current edge output is “240 ° CA”, the deviation amount Z is “−30 ° CA”, and the correction amount H is “+15”. In the case of “° CA”, the correction amount H = “+ 15 ° CA” is added to the target operating angle INCAMp in step S190. As a result, the actual position of the control shaft 14 moves in the direction in which the maximum lift amount VL is increased by 15 ° CA in terms of operating angle. Therefore, the actual position of the control shaft 14 is shifted in the direction in which the maximum lift amount VL is reduced by 30 ° CA in terms of operating angle, but the maximum lift amount VL is in the amount of 15 ° CA in terms of operating angle. It will move in the direction of increasing. Therefore, the deviation amount between the position of the control shaft 14 recognized by the electronic control unit 50 and the actual control shaft 14 is improved from “−30 ° CA” to “−15 ° CA”. In addition, the process of step S100-S130 comprises the said calculation process.

  Next, it is determined whether or not the absolute value of the current correction amount H calculated in step S130 is greater than or equal to the absolute value of the correction amount H set last time (S140). If the absolute value of the current correction amount H is equal to or greater than the absolute value of the correction amount H set last time (S140: YES), the correction amount H calculated this time is set as the correction amount H (S150). ). On the other hand, when the absolute value of the correction amount H of this time is less than the absolute value of the correction amount H set last time (S140: NO), the correction amount H calculated last time is set as the correction amount H (S155). ). By executing these steps S140, S150, and S155, the absolute value of the correction amount H is maintained at the largest value among the calculated correction amounts H. When the absolute value of the correction amount H is maintained at the largest value in this way, the actual position of the control shaft 14 is easily corrected in the direction in which the maximum lift amount VL is increased. Accordingly, when the actual position of the control shaft 14 is shifted in the direction in which the maximum lift amount VL decreases, there is a concern that engine stall may occur due to a shortage of the intake air amount, but correction with the correction amount H is performed. As a result, the maximum lift amount VL is corrected in the increasing direction, so that the shortage of the intake air amount can be suppressed.

  Next, it is determined whether or not the current operating angle INCAM is less than the determination value α (S160). If the current operating angle INCAM is greater than or equal to the determination value α (S160: NO), the target operating angle is determined in step S190. INCAMp is corrected (target operating angle after correction INCAMp ← target operating angle before correction INCAMp + correction amount H).

  On the other hand, when the current operating angle INCAM is less than the determination value α (S160: YES), it is next determined whether or not the intake pressure PM is stable (S170). When the intake pressure PM is not stable (S170: NO), the target operating angle INCAMp is corrected in step S190.

  On the other hand, when the intake pressure PM is stable (S170: YES), the correction amount H is further corrected based on the difference ΔPM between the intake pressure PM and the estimated intake pressure PMs (S180). Based on the above, the target operating angle INCAMp is corrected (S190). The process of step S180 is performed for the following reason.

  That is, the correction amount H calculated based on the sensor detection includes the influence of the error factor as described above. Therefore, in order to suppress the influence of the error factor, a correction process for the correction amount H is executed in step S180.

  First, as the maximum lift amount VL of the intake valve 10 decreases, the opening area of the intake port decreases, so the amount of intake air that passes through the intake valve 10 and flows into the combustion chamber decreases. Therefore, the intake pressure PM increases as the maximum lift amount VL decreases (close to atmospheric pressure, the negative pressure decreases). Accordingly, there is a difference between the position of the control shaft 14 recognized by the electronic control unit 50 and the actual position of the control shaft 14, and the actual maximum lift amount VL of the intake valve 10 corresponds to the target value (corresponding to the target operating angle INCAMp). Is smaller than the maximum lift amount), a difference occurs between the estimated intake pressure PMs estimated from the engine operating state and the actual intake pressure PM. Here, the actual intake pressure PM changes according to the actual position of the control shaft 14 (actual maximum lift amount VL), and the estimated intake pressure PMs is a control recognized by the electronic control unit 50. The value is changed according to the position of the shaft 14 (the maximum lift amount VL recognized by the electronic control unit 50). Therefore, the degree of divergence between the actual intake pressure PM and the estimated intake pressure PMs depends on the amount of deviation between the position of the control shaft 14 recognized by the electronic control unit 50 and the actual position of the control shaft 14. It becomes.

  Therefore, in step S180, the correction amount H is corrected according to the degree of deviation between the intake pressure PM and the estimated intake pressure PMs in the same engine operating state, thereby suppressing the influence of the error factors described above. .

  Here, as described above, the intake pressure increases as the maximum lift amount VL of the intake valve 10 decreases (the pressure approaches the atmospheric pressure, and the negative pressure decreases). Therefore, when the actual intake pressure PM is higher than the estimated intake pressure PMs, the actual maximum lift amount VL is smaller than the maximum lift amount VL recognized by the electronic control unit 50. Conversely, when the actual intake pressure PM is lower than the estimated intake pressure PMs, the actual maximum lift amount VL is larger than the maximum lift amount VL recognized by the electronic control unit 50.

  Therefore, in step S180, when the intake pressure PM is higher than the estimated intake pressure PMs, the maximum lift amount VL increases as the degree of deviation (difference ΔPM) between the estimated intake pressure PMs and the intake pressure PM increases. The correction amount H is corrected. When the intake pressure PM is lower than the estimated intake pressure PMs, the correction amount H is set so that the maximum lift amount VL decreases as the degree of deviation (difference ΔPM) between the estimated intake pressure PMs and the intake pressure PM increases. Will be corrected.

  Incidentally, the estimated intake pressure PMs is estimated based on the current value of the operating angle INCAM (maximum lift amount VL) calculated from the intake air amount QA, the engine speed NE, the throttle opening degree TA, and the detected value of the rotation amount sensor 26. The

  Further, the difference between the maximum lift amount VL recognized by the electronic control unit 50 and the actual maximum lift amount VL, that is, the difference between the actual intake pressure PM and the estimated intake pressure PMs is the maximum lift amount VL of the intake valve 10. The smaller the value, the larger the tendency. Therefore, the deviation between the maximum lift amount VL recognized by the electronic control unit 50 and the actual maximum lift amount VL is more reflected in the degree of deviation as the maximum lift amount VL is smaller. Therefore, in the present embodiment, the correction process is performed when the operating angle INCAM is smaller than the determination value α, that is, when the engine operating state is such that the maximum lift amount VL is smaller than a predetermined value, through the determination process in step S160. The process of step S180 is performed, and thereby the correction amount H is corrected with high accuracy.

  Further, the correction process of the target operating angle INCAMp including the calculation process is executed on the condition that the learning of the reference position F has been completed. Therefore, after the accuracy of the position of the control shaft 14 (working angle INCAM) calculated based on the output value of the rotation amount sensor 26 is secured, the working angle INCAM (specific position sensor value) is read in step S110. Is called. Therefore, the accuracy of the correction amount H of the control shaft 14 calculated based on the difference between the specific position of the control shaft 14 and the specific position sensor value is improved.

FIG. 5 shows an example of how the correction amount H is set by the correction process.
First, learning of the reference position F is started when the control shaft 14 is moved to the movable limit position at time t1, and when learning of the reference position F is completed at time t2, the working angle INCAM and the maximum corresponding to the engine operating state are started. The lift amount VL is variably set. Then, every time the control shaft 14 passes the specific positions A, B, and C, the correction amount H is calculated and the target operating angle INCAMp is corrected (time t3, t4, t5).

  Further, when the operating angle INCAM is less than the determination value α and it is determined that the intake pressure PM is stable (the fluctuation amount is equal to or less than a predetermined value) (time t6), the correction amount H is corrected by the difference ΔPM, The target operating angle INCAMp is corrected by the corrected correction amount H.

As described above, according to the present embodiment, the following effects can be obtained.
(1) Based on the deviation amount Z between the specific position (reference working angle INCAMb) of the control shaft 14 and the specific position sensor value (working angle INCAM read in step S110 when an affirmative determination is made in step S100). A correction amount H for correcting the actual position of the control shaft 14 is calculated. As a result, the deviation between the position of the control shaft 14 recognized by the electronic control unit 50 and the actual position of the control shaft 14 can be suppressed to some extent.

  On the other hand, the correction amount H calculated based on the detection of the sensor includes the error factors described above, that is, the dimension error of the member to which the shaft sensor 28 is attached, the attachment error of the shaft sensor 28, and the output characteristics of the shaft sensor 28 itself. This includes the influence of variations, dimensional errors and mounting errors of the target 30, and the like.

Therefore, in order to suppress the influence of these error factors, a correction process for correcting the correction amount H in accordance with the degree of deviation (difference ΔPM) between the intake pressure PM and the estimated intake pressure PMs in the same engine operating state is executed in step S180. Like to do. Thereby, the influence of the error factor mentioned above is suppressed suitably. Therefore, it is possible to more appropriately suppress the deviation between the position of the control shaft 14 recognized by the electronic control unit 50 and the actual position of the control shaft 14, and the maximum lift amount VL of the intake valve 10 is set according to the engine operating state. It will be possible to change to an appropriate amount.
(2) In step S180, when the intake pressure PM is higher than the estimated intake pressure PMs, the maximum lift amount VL increases as the degree of deviation (difference ΔPM) between the estimated intake pressure PMs and the intake pressure PM increases. The correction amount H is corrected. Therefore, the correction amount H can be appropriately corrected.
(3) In step S180, when the intake pressure PM is lower than the estimated intake pressure PMs, the maximum lift amount VL decreases as the deviation degree (difference ΔPM) between the estimated intake pressure PMs and the intake pressure PM increases. The correction amount H is corrected so that Therefore, the correction amount H can be appropriately corrected.
(4) The correction process is performed when the operating angle INCAM is less than the determination value α, that is, when the maximum lift amount VL is in an engine operating state that is smaller than a predetermined value. Therefore, the correction amount H can be corrected with high accuracy.
(5) The target working angle INCAMp correction process including the calculation process is executed on the condition that the learning of the reference position F has been completed. Therefore, the accuracy of the correction amount H of the control shaft 14 calculated based on the difference between the specific position and the specific position sensor value can be improved.

In addition, the said embodiment can also be changed and implemented as follows.
-You may make it abbreviate | omit the process of step S140-S155 shown in FIG.
If the position of the control shaft 14 can be calculated accurately based on the output of the rotation amount sensor 26 even if the learning of the reference position F is not completed, the target working angle INCAMp is corrected without waiting for the completion of learning of the reference position F. Processing may be performed.
If the deviation between the maximum lift amount VL recognized by the electronic control unit 50 and the actual maximum lift amount VL can be sufficiently grasped, the determination process in step S160 may be omitted.
The lift amount variable mechanism 12 is a mechanism that changes the maximum lift amount VL of the intake valve 10 by driving the control shaft 14 in the axial direction, but it is a mechanism that changes the maximum lift amount VL in another manner. There may be. For example, a variable lift amount mechanism that changes the maximum lift amount VL of the intake valve 10 by rotating a control shaft by a motor may be used.
-The specific numerical value demonstrated by the said embodiment is an example, and you may make it set another value.

  DESCRIPTION OF SYMBOLS 10 ... Intake valve, 12 ... Lift amount variable mechanism, 14 ... Control shaft, 16 ... Actuator, 16A ... Output shaft, 18 ... Fastening member, 20 ... Roller arm, 22 ... Swing cam, 24 ... Rocker arm, 26 ... Rotation Quantity sensor, 28 ... Shaft sensor, 28A, 28B, 28C ... Sensor element, 30 ... Target, 50 ... Electronic control device, 100 ... Crank angle sensor, 110 ... Air flow meter, 120 ... Throttle sensor, 130 ... Intake pressure sensor.

Claims (5)

Based on an output value of a lift amount variable mechanism that changes the maximum lift amount of the intake valve to an amount according to the engine operating state by driving a control shaft by a motor, and an output value of a rotation amount sensor that detects the rotation amount of the motor. A control device for a lift variable mechanism that calculates the position of a control shaft,
A position sensor that detects a position of the control shaft by detecting a detection portion provided on the control shaft, and an intake pressure sensor that detects an intake pressure in the intake passage,
The position of the control axis calculated based on the output value of the rotation amount sensor when the detection part comes to a predetermined specific position with the movement of the control axis is read as a specific position sensor value, Executing a calculation process for calculating a correction amount for correcting the actual position of the control axis based on a deviation between the specific position and the specific position sensor value;
A control device for a variable amount of lift mechanism, wherein, in a predetermined engine operating state, a correction process for correcting the correction amount is executed in accordance with a degree of deviation between the intake pressure and the estimated intake pressure in the same engine operating state. 2. The correction amount is corrected such that when the intake pressure is higher than the estimated intake pressure, the maximum lift amount increases as the degree of deviation between the estimated intake pressure and the intake pressure increases. Control device for variable lift amount. The correction amount is corrected such that when the intake pressure is lower than the estimated intake pressure, the maximum lift amount decreases as the degree of deviation between the estimated intake pressure and the intake pressure increases. The lift amount variable mechanism control device described in 1. The control device for a lift amount variable mechanism according to any one of claims 1 to 3, wherein the correction process is performed when the engine is in an engine operating state in which the maximum lift amount is smaller than a predetermined value. The rotation amount sensor is a relative position sensor that detects a relative movement amount of a detection target, and the calculation of the position of the control axis based on the output value of the rotation amount sensor is performed from a reference position of a predetermined control axis. This is done by calculating the relative movement amount of
The control device for a variable lift amount mechanism according to any one of claims 1 to 4, wherein the calculation process is executed on condition that learning of the reference position is completed.

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