JP6186953B2 - Valve timing control device for internal combustion engine - Google Patents

Description

  The present invention relates to a valve timing control device that changes the opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine, and more particularly to determination of a lock pin release operation from a predetermined lock position.

  A variable valve timing mechanism that changes the opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine according to a torque request, for example, a rotational phase difference between a rotating member on the crankshaft side and a rotating member on the camshaft side of the internal combustion engine, It is configured to change within a predetermined range using a hydraulic actuator.

  When the operation of the internal combustion engine is stopped, the rotational phase difference between these two rotating members is locked at the intermediate lock position by the lock pin. The lock pin penetrates from one of the two members to the other in the intermediate lock position, thereby locking the rotational phase difference between the two rotation members, in other words, the relative rotation position, to the intermediate lock position.

  When starting the internal combustion engine, first, the intermediate lock is released by pulling out the lock pin, and then the valve timing variable mechanism is controlled so that the required rotational phase difference between the two rotating members is realized. The prior art of Patent Document 1 detects the actual rotational phase difference between the two rotating members, and determines that the intermediate lock release is not correctly performed when the actual rotational phase difference does not converge to the required rotational phase difference. ing. Patent Document 1 further sets a standby time from the start of control to the required rotational phase difference to the determination of intermediate lock release based on the dynamic characteristics of the hydraulic circuit that drives the hydraulic actuator.

JP 2013-019353 A

  When the required rotational phase difference is away from the intermediate lock position where the lock is performed, the time required for the hydraulic actuator to drive the two members to the required rotational phase difference after the lock pin releasing operation becomes longer. In other words, it is not possible to determine whether or not the lock pin release operation has been completed unless a considerable time has elapsed since the lock pin release operation.

  On the other hand, simultaneously with the output of the lock pin release command. Various open loop operations may be performed on the premise of releasing the lock pin. In this case, if it is determined that the release of the lock pin has not been completed after a considerable time has elapsed since the release operation of the lock pin, the open loop operation has progressed considerably at that time, resulting in an erroneous operation. A near situation will appear.

  The present invention has been made to solve the above problems inherent in the prior art, and an object thereof is to shorten the time required for determining the completion of the release of the lock pin.

  In order to achieve the above object, the present invention changes the valve timing of the internal combustion engine in accordance with the rotational phase difference between the two members, and changes from one of the two members to the other at a predetermined intermediate lock position. The present invention is applied to a valve timing control device for an internal combustion engine including a variable valve timing mechanism having a lock pin that locks the valve timing at an intermediate lock position by penetrating the lock pin. The valve timing control device is configured as follows.

  That is, the valve timing control device outputs an intermediate lock release command for pulling out a lock pin penetrating from one of the two members to the other in response to an input of an intermediate lock release request from the outside to the valve timing variable mechanism. After the output of the intermediate lock release command, the valve timing variable mechanism is controlled so that the rotational phase difference between the two members becomes a predetermined target rotational phase difference. Even after the actual rotational phase difference between the two members is detected and the valve timing variable mechanism is controlled so that the rotational phase difference between the two members becomes a predetermined target rotational phase difference, the actual rotational phase difference and the target rotational position are also controlled. When the difference from the phase difference does not become a predetermined value or less, it is determined that the intermediate lock release is not completed. The target rotational phase difference used for this determination is set to the rotational phase difference angle from the intermediate lock position corresponding to the minimum deviation of the rotational phase difference that can determine that the actual rotational phase difference is different from the target rotational phase difference.

  By setting the target rotational phase difference after the intermediate unlock command to the rotational phase difference from the lock position corresponding to the minimum deviation of the rotational phase difference that can be determined that the rotational phase difference is different from the target rotational phase difference, It is possible to determine whether or not the intermediate lock release has been completed in the shortest time. As a result, even if it is determined that the intermediate lock release has not been completed, it is started simultaneously with the output of the intermediate lock release command. It is possible to minimize the influence of the open loop operation on the premise of the intermediate lock release.

It is a schematic block diagram of the valve timing control apparatus of the internal combustion engine by embodiment of this invention. It is a part of flowchart explaining the intermediate | middle unlocking routine which the controller by embodiment of this invention performs. It is a remaining one part of the flowchart explaining the intermediate | middle lock release routine which the controller by embodiment of this invention performs. It is a timing chart which shows a control result when intermediate lock is canceled within predetermined time by execution of an intermediate lock release routine. It is a timing chart which shows a control result when intermediate lock is not released within predetermined time by execution of an intermediate lock release routine.

  Referring to FIG. 1, a valve timing control device 2 for an internal combustion engine 1 according to an embodiment of the present invention includes a valve timing variable mechanism 3 that changes the valve timing of the internal combustion engine 1.

  The internal combustion engine 1 opens and closes an intake valve and an exhaust valve by a cam fixed to an intake camshaft that rotates in synchronization with a crankshaft. The exhaust valve is opened and closed by a cam fixed to the exhaust camshaft that rotates in synchronization with the crankshaft. The variable valve timing mechanism 3 uses a hydraulic actuator to change the rotational phase difference between the crankshaft and the camshaft, which are two rotating members, for each of the intake valve and the exhaust valve. The timing is changed between a most advanced position and a most retarded position set in advance.

  The variable valve timing mechanism 3 has a function of locking the valve timing at an intermediate lock position set between the most advanced position and the most retarded position. This is done by penetrating a lock pin from one of the crankshaft and camshaft to the other. When the lock pin penetrates from one of the crankshaft and the camshaft to the other, the rotational phase difference between the crankshaft and the camshaft is mechanically locked at the intermediate lock position. The lock pin is locked by an actuator that responds to a command signal from the controller 4.

  The locking operation is performed, for example, when the operation of the internal combustion engine 1 is stopped. When the operation of the internal combustion engine 1 is stopped, the hydraulic pressure supply to the variable valve timing mechanism 3 is also stopped. Therefore, before the internal combustion engine 1 is stopped, a lock command signal is output from the controller 4 to the variable valve timing mechanism 3 to lock the actuator so that the internal combustion engine 1 can be restarted reliably at a predetermined valve timing. The valve timing is locked at the intermediate lock position by driving the pin to the lock position.

  Therefore, the internal combustion engine 1 is always started in an intermediate lock state in which the valve timing is always fixed at the intermediate lock position. The internal combustion engine 1 after starting changes the valve timing according to the operating conditions. In order to change the valve timing, it is necessary to first withdraw the lock pin and release the locked state at the intermediate lock position. This operation is performed by outputting a release command signal from the controller 4 to the variable valve timing mechanism 3.

  Since the variable valve timing mechanism 3 having the lock mechanism as described above is a known mechanism, for example, from Patent Document 1, detailed description of the structure is omitted.

  By the way, when releasing the lock to the intermediate lock position of the valve timing after the internal combustion engine 1 is started, that is, the intermediate lock, other parameters related to the operation control of the internal combustion engine 1 such as fuel injection control are also used. In parallel, a control command is output. These control commands are output on the assumption that the intermediate lock is released and the valve timing is controlled to a new target valve timing.

  If the operation of the actuator pulling out the lock pin from the lock position is not smoothly performed in response to the input of the release command signal to the variable valve timing mechanism 3, the valve timing and the operation control of the internal combustion engine 1 are continued if the intermediate lock is not released. Consistency with the other parameters is lost, which adversely affects the operating performance and exhaust plasticity of the internal combustion engine 1.

  Therefore, the valve timing control device 2 has a function of determining whether or not the lock pin has been pulled out from the lock position. For this purpose, the valve timing control device 2 includes a rotational phase difference detection sensor 5 that detects an actual rotational phase difference between the crankshaft and the camshaft. The controller 4 outputs the target valve timing to the valve timing variable mechanism 3 after outputting the intermediate lock release command signal.

  It takes time to pull out the lock pin from the lock position and change the rotational phase difference between the crankshaft and the camshaft to a rotational phase difference corresponding to the target valve timing by hydraulic control. Therefore, the controller 4 waits for a predetermined time from the output of the release command signal and the new target valve timing, and then corresponds to the actual rotational phase difference between the crankshaft and the camshaft detected by the rotational phase difference detection sensor 5 and the target valve timing. The rotational phase difference is compared, and based on these deviations, it is determined whether or not the lock has been properly released.

  The standby time is determined based on the total time of the time required for the unlocking operation to pull out the lock pin from the lock position and the time required to change the rotational phase difference from the intermediate lock position to the position corresponding to the target valve timing. The former is constant, but the latter depends on the angular distance between the target valve timing equivalent position and the intermediate lock position. That is, the greater the angular distance from the intermediate lock position of the target valve timing equivalent position, the longer the time required for hydraulic control to achieve the target valve timing.

  As described above, it is preferable that the waiting time is short considering that other parameters related to engine operation control are changed in parallel with the output of the target valve timing. On the other hand, the target valve timing can be set from the most advanced position to the most retarded position. Therefore, in order to ensure the determination of unlocking, it is necessary to set the standby time on the basis of the most advanced position or the most retarded position that is the maximum angular distance from the intermediate lock position.

  However, as a result, an increase in waiting time is inevitable.

  The valve timing control device 2 according to this embodiment is configured so that the target valve timing output immediately after the output of the release command signal instructing unlocking of the lock pin is in the vicinity of the intermediate lock position and different from the actual rotational phase difference. Is set to the minimum value corresponding to the rotational phase difference that can be determined. With this setting, the standby time can be shortened as much as possible. After confirming that the target valve timing has been achieved, the controller 4 controls the valve timing to a new target valve timing based on the operating state of the internal combustion engine 1.

  In order to realize the above control, the controller 4 is constituted by a microcomputer having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface). The It is also possible to configure the controller with a plurality of microcomputers.

  Next, an intermediate lock release routine executed by the controller 4 in order to realize the above control will be described with reference to FIGS. This routine is repeatedly executed at regular intervals of, for example, 10 milliseconds during the operation of the internal combustion engine 1. Here, the target for releasing the intermediate lock is the intake valve of the internal combustion engine 1.

  Referring to FIG. 2, in step S1, the controller 4 determines whether or not the intermediate lock fixing flag fA is zero. The intermediate lock fixing flag fA is a flag set to 1 when the lock pin is not properly pulled out. The initial value of the intermediate lock adhering flag fA is 0.

  If the determination in step S1 is affirmative, the controller 4 performs the process of S2-S4. If the determination of step S1 is negative, the controller 4 performs the process of steps S24-S26 in FIG.

  In step S2, the controller 4 determines whether or not the intermediate lock release request flag fB is zero. The intermediate lock release request flag fB is a flag set to 1 when the release of the intermediate lock is requested. The intermediate lock release request flag fB is output when the supply of hydraulic pressure necessary for operating the variable valve timing mechanism 3 is enabled by starting the internal combustion engine 1. The initial value of the intermediate lock release request flag fB is 0.

  If the determination in step S2 is affirmative, that is, if there is no intermediate lock release request, the controller 4 performs the process in step S3. If the determination in step S2 is negative, that is, if there is an intermediate lock release request, the controller 4 performs the process in step S5.

  In step S3, the controller 4 sets the target intake VTC conversion angle tVTCi to A that is an intermediate lock phase difference angle. Here, VTC is an abbreviation for valve timing control. The target intake VTC conversion angle tVTCi is a value representing the rotational phase difference between the crankshaft and the camshaft corresponding to the target valve timing. The controller 4 also resets the intermediate lock release flag fC to 0 in step S3. The intermediate lock release flag fC is a flag set to 1 when the release of the intermediate lock is confirmed. The initial value of the intermediate lock release flag fC is 0.

  In the next step S4, the controller 4 prohibits the operation of the exhaust VTC because the intermediate lock of the intake VTC is not released. The valve timing control device 2 also controls the exhaust VTC as well as the intake VTC. After step S4, the controller 4 ends the routine.

  On the other hand, in step S5, the controller 4 determines whether or not the intermediate lock release request flag fB was 0 when the previous routine was executed. Here, the intermediate lock release request flag at the time of the previous routine execution is represented by fBz. If the determination is affirmative, the controller 4 performs steps S6-S9. If the determination is negative, the controller 4 performs the process of step S10 in FIG.

  In step S <b> 6, the controller 4 resets a timer Timer that measures the execution duration of the intermediate lock release operation to 0.

  In step S7, the controller 4 outputs an intermediate lock release command signal for pulling out the lock pin.

  In step S8, the controller 4 sets the target intake VTC conversion angle tVTCi to a rotational phase difference angle B that is in the vicinity of the intermediate lock position phase difference angle A and is behind the intermediate lock phase difference angle A. The rotational phase difference angle B is set to a rotational phase difference angle that is separated from the intermediate lock phase difference angle A by a minimum distance that can be determined that the intermediate lock has been reliably released. Whether it is possible to determine that the intermediate lock has been reliably released depends on the resolution and detection error of the rotational phase difference detection sensor 5. Therefore, the value of the rotational phase difference angle B is determined in consideration of these factors.

  Here, the reason why the target intake VTC conversion angle tVTCi is set to the rotational phase difference angle B different from the intermediate lock position phase difference angle A immediately after the output of the release command signal will be described.

  In response to the input of the intermediate unlock command signal, the variable valve timing mechanism 3 supplies hydraulic pressure to the hydraulic actuator, and the hydraulic actuator attempts to pull the lock pin out of the penetration hole against the spring. Immediately after that, when the target intake VTC conversion angle tVTCi is set to the rotational phase difference angle B, the valve timing variable mechanism 3 tries to bring the actual target intake VTC conversion angle rVTCi closer to the rotational phase difference angle B, thereby It exerts a transverse force. This transverse force increases the frictional resistance between the wall of the penetration hole through which the lock pin penetrates and the lock pin. On the other hand, the camshaft receives a large reaction force when the cam moves over the rocker arm connected to the valve. This reaction force reduces the frictional resistance. As a result, the frictional resistance of the lock pin repeatedly increases and decreases, and the lock pin is pulled out by the hydraulic actuator in stages each time the frictional resistance decreases.

  If the ease of pulling out the lock pin is taken into consideration, it is desirable to pull out the lock pin while maintaining the target intake VTC conversion angle tVTCi at the intermediate lock position phase difference angle A. However, in that case, the timing for controlling the target intake VTC conversion angle tVTCi to the rotational phase difference angle B is delayed, and as a result, the determination of the intermediate lock release is also delayed. By setting the target intake VTC conversion angle tVTCi to the rotational phase difference angle B immediately after the output of the release command signal, it is possible to determine intermediate lock release at an early stage.

  Now, after the processing of step S8, the controller 4 terminates the routine after prohibiting the operation of the exhaust VTC in step S9.

  Referring to FIG. 3, in step S <b> 10, the controller 4 determines whether or not the intermediate lock release flag fC is 0. If the determination is affirmative, that is, if the intermediate lock has not been released, the controller 4 performs the process of step S11. On the other hand, if the determination in step S10 is negative, that is, if the intermediate lock is released, the controller 4 performs the processes in steps S22 and S23.

  In step S11, the controller 4 determines whether or not the timer Timer has reached the predetermined time Tth. The predetermined time Tth is a threshold value necessary for determining whether or not the lock pin is fixed at the intermediate lock position. The predetermined time Tth is set in advance as follows.

  When the extraction of the lock pin is completed, the valve timing of the intake VTC by the variable valve timing mechanism 3, that is, the rotation phase difference between the crankshaft and the camshaft can be changed. As a result, the actual rotational phase difference between the crankshaft and the camshaft detected by the rotational phase difference detection sensor 5 approaches the rotational phase difference angle B of the target value. With respect to this process, the predetermined time Tth is a value obtained by determining the time until the actual rotational phase difference becomes substantially equal to the rotational phase difference angle B with some margin based on experiments or simulations.

  In this valve timing control device 2, the rotational phase difference angle B is set to a value that is in the vicinity of the intermediate lock position phase difference angle A and on the retard side with respect to the intermediate lock phase difference angle A. The rotational phase difference angle B is separated from the intermediate lock phase difference angle A by only the minimum angle at which it can be determined that the intermediate lock has been reliably released, so it is compared with the maximum advance angle position or the minimum advance angle position. Thus, the position is very close to the intermediate lock position A. Therefore, the control of the rotational phase difference from the intermediate lock position phase difference angle A to the rotational phase difference angle B can be performed in a short time, and the predetermined time Tth can be set to a small value.

  If the determination in step S11 is affirmative, the controller 4 performs the process in step S12. If the determination is negative, the controller 4 performs the process of step S19.

  In step S12, the controller 4 continues to output the release command signal for pulling out the lock pin. In step S13, the controller 4 maintains the target intake VTC conversion angle tVTCi at the rotational phase difference angle B.

  In the next step S14, the controller 4 determines that the absolute value of the difference between the rotational phase difference angle B, which is the target intake VTC conversion angle tVTCi, and the actual intake VTC conversion angle rVTCi detected by the rotational phase difference detection sensor 5 is a threshold value. Determine if C is exceeded. Here, the actual intake VTC conversion angle rVTCi is a value representing the actual rotational phase difference between the crankshaft and the camshaft.

  When the determination is positive, the controller 4 updates the timer value by adding an increment ΔT to the previous value Timerz of the timer Timer in step S15.

  In the next step S16, the controller 4 prohibits the operation of the exhaust VTC and ends the routine.

  On the other hand, if the determination in step S14 is negative, the absolute value of the difference between the rotational phase difference angle B and the actual intake VTC conversion angle rVTCi detected by the rotational phase difference detection sensor 5 is equal to or less than the threshold value C. Means. In that case, the controller 4 sets the intermediate lock release flag fC to 1 which means completion of the intermediate lock release in step S17. In step S18, after permitting the operation of the exhaust VTC, the controller 4 ends the routine.

  Returning to step S11, when the timer Timer reaches the predetermined time Tth, the determination in step S11 turns negative. In this case, the controller 4 performs steps S19 to S21.

  In step S19, the controller 4 sets the target intake VTC conversion angle tVTCi to the intake VTC conversion angle VTCi0. The intake VTC conversion angle VTCi0 corresponds to the valve timing of the internal combustion engine 1 during normal operation, and is a value that changes according to the operating state of the internal combustion engine 1. Here, the target intake VTC conversion angle tVTCi is set to the intake VTC conversion angle VTCi0 for the following reason.

  Step S19 is executed when the intermediate lock release is not completed within the predetermined time Tth, which means that the lock pin has failed to be pulled out from the penetration hole. In this case, by changing the target intake VTC conversion angle tVTCi from the rotational phase difference angle B when the intermediate lock is released to the intake VTC conversion angle VTCi0, the load acting on the lock pin changes, and as a result, the lock pin is pulled out. Because there is a possibility of success.

  In the next step S20, the controller 4 sets the intermediate lock fixing flag fA to 1 representing fixing.

  In the next step S21, after prohibiting the operation of the exhaust VTC, the controller 4 ends the routine. The process of steps S19 to S21 corresponds to a process when the intermediate lock release fails.

  Returning to step S10, if the intermediate lock release flag fC is not 0, that is, if the intermediate lock release is confirmed, the controller 4 performs the processes of steps S22 and S23.

  In step S22, the controller 4 sets the target intake VTC conversion angle tVTCi to the intake VTC conversion angle VTCi0.

  In the next step S23, after prohibiting the operation of the exhaust VTC, the controller 4 ends the routine.

  Returning to step S1, if the intermediate lock fixing flag fA is not 0, that is, if it is determined that the intermediate lock release has failed, the controller 4 performs the processing of steps S24-S26. This process is executed in the routine execution after the processes of steps S19 to S21 are performed.

  In step S24, the controller 4 lights a warning light provided in the vehicle interior. This informs the vehicle driver that the internal combustion engine 1 needs to be serviced.

  In the next step S25, the controller 4 maintains the target intake VTC conversion angle tVTCi at the intake VTC conversion angle VTCi0.

  In the next step S26, after the prohibition of the operation of the exhaust VTC is continued, the controller 4 ends the routine.

  In the above intermediate lock release routine, steps S3 and S4 correspond to the process before the intermediate lock release request is issued. Steps S6 to S9 correspond to processing immediately after the intermediate lock release request is issued. Steps S12 to S16 correspond to an intermediate lock release operation. Steps S17 to S18 correspond to the processing immediately after the intermediate lock release confirmation. Steps S22 and S23 correspond to processing at the time of routine execution after the next time when intermediate lock release is confirmed. Steps S19 to S21 correspond to processing immediately after determining that the intermediate lock release has failed. Steps S24 to S26 correspond to processing at the time of routine execution after the next time when it is determined that the intermediate lock release has failed.

  The execution result of the intermediate lock release routine will be described with reference to FIGS.

  FIG. 4 shows a situation where the intermediate lock release is completed within the predetermined time Tth. FIG. 5 shows a situation where it is determined that the intermediate lock release has not been completed within the predetermined time Tth and the intermediate lock release has failed.

  Referring to FIG. 4, after the internal combustion engine 1 is started, an intermediate lock release request is input at time t1, and the intermediate lock release request flag fB changes from 0 indicating no request to 1 indicating request. As a result, steps S6 to S9 are performed, a lock pin release command signal is output, and the timer Timer starts counting. Further, the target intake VTC conversion angle tVTCi is changed from the intermediate lock position phase difference angle A so far to the phase difference angle B in the vicinity of the intermediate lock position phase difference angle A and on the retard side with respect to the intermediate lock phase phase difference angle A. The Further, the prohibition of operation of the exhaust VTC is maintained.

  In the routine execution after the next time, this state is maintained in steps S12, S13, and S16. On the other hand, whether or not the timer Timer has reached the predetermined time Tth in step S11, and whether or not the absolute value of the difference between the rotational phase difference angle B and the actual intake VTC conversion angle rVTCi exceeds the threshold value C in step S14. judge.

  When the lock pin is completely pulled out, the actual intake VTC conversion angle rVTCi rapidly follows the rotational phase difference angle B of the target value as shown by the broken line of the intake VTC in the drawing. As a result, the absolute value of the difference between the rotational phase difference angle B and the actual intake VTC conversion angle rVTCi becomes equal to or less than the threshold value C at time t2 in step S14. Thereby, it is determined that the intermediate lock release is completed, and the intermediate lock release determination flag fC is set to 1 in step S17. In step S18, the exhaust VTC operation is permitted, and in the next routine execution, the target intake VTC conversion angle tVTCi is set to the intake VTC conversion angle VTCi0 in step S22.

  As a result of this processing, after time t2, both the intake VTC and the exhaust VTC are operated so as to have valve timings according to the operating state of the internal combustion engine 1.

  Referring to FIG. 5, the situation until the intermediate lock release request flag fB changes from 0 to 1 at time t1 is the same as the timing chart of FIG. After time t1, the intermediate lock release operation is performed in steps S12, S13, and S16 as in the timing chart of FIG. However, since the lock pin is not properly pulled out, the actual intake VTC conversion angle rVTCi does not change from the intermediate lock position phase difference angle A as shown by the broken line of the intake VTC in the figure.

  When the timer Timer reaches the predetermined time Tth at time t3, the determination in step S11 is negative, the target intake VTC conversion angle tVTCi is set to the intake VTC conversion angle VTCi0 in step S22, and the intermediate lock fixing flag is set in step S20. fA is set to 1 representing sticking. Further, the target intake VTC conversion angle tVTCi is maintained at the intake VTC conversion angle VTCi0 in step S21, and the prohibition of operation of the exhaust VTC is maintained in step S26.

  As described above, the valve timing control device 2 sets the target intake VTC conversion angle tVTCi, which is the target rotational phase difference in the intermediate unlocking operation, and the difference between the actual rotational phase difference and the target rotational phase difference is a predetermined value or more. This is set to the rotational phase difference angle B from the intermediate lock position, which corresponds to the minimum deviation of the rotational phase difference that can be determined.

  Therefore, the time required for confirming the intermediate lock release is shortened, and it is possible to determine whether the intermediate lock release has been properly performed in a short time from the intermediate lock release command. Even if a change in other parameters related to operation control of the internal combustion engine 1 is output in parallel with the intermediate unlock command, it can be determined in a short time whether the intermediate unlock has been completed. However, it is possible to quickly eliminate the parameter change based on the intermediate lock release, and to minimize the influence of the parameter change based on the intermediate lock release.

  When it is determined that the intermediate lock release has failed, the valve timing control device 2 sets the target intake VTC conversion angle tVTCi, which is the target rotational phase difference, to the target value VTCi0 based on the operating state of the internal combustion engine 1. . With this setting, even when it is determined that the intermediate lock release has failed, the value of the target intake VTC conversion angle tVTCi changes, so that the load applied to the lock pin changes and the possibility that the lock pin can be successfully pulled out is increased. Can do.

  This valve timing control device 2 prohibits the operation of the valve timing of the exhaust valve unless the difference between the actual rotational phase difference between the two members that open and close the intake valve and the target rotational phase difference is less than a predetermined value. . That is, unless the intermediate lock release is confirmed, the operation of the valve timing of the exhaust valve is prohibited. Therefore, it is possible to prevent control mismatch caused by operating only the valve timing of the exhaust valve in a state in which the valve timing of the intake valve is impossible.

  Furthermore, in this valve timing control device 2, the time given to the determination of the intermediate lock release is limited to a predetermined time Tth set based on the rotational phase difference angle B. As a result, it is possible to confirm the intermediate lock release in a short time.

  As described above, the present invention has been described through specific embodiments. However, the present invention is not limited to the above embodiments. A person skilled in the art can make various modifications or changes to the above-described embodiments within the scope of the claims.

  For example, in the above embodiment, the present invention is applied to the determination of the release of the intermediate lock that fixes the valve timing of the intake valve, but the present invention is applied to the determination of the release of the intermediate lock that fixes the valve timing of the exhaust valve. It is also possible to do.

  Further, in this valve timing control device 2, the lock pin can be pulled out after the intermediate lock fixing flag fA is set to 1. Therefore, the controller 4 continues to detect the actual rotational phase difference and determine the difference between the actual rotational phase difference and the target rotational phase difference even after determining that the intermediate lock release has failed after the predetermined time Tth. You may do it. When the absolute value of these differences becomes equal to or less than the predetermined value C, the intermediate lock fixing flag fA is reset to 0.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Valve timing control apparatus 3 Valve timing variable mechanism 4 Controller 5 Rotation phase difference detection sensor

Claims (4)

The valve timing of the internal combustion engine is changed according to the rotational phase difference between the two members, and the valve timing is intermediately locked by inserting a lock pin from one of the two members to the other at a predetermined intermediate lock position. In a valve timing control device for an internal combustion engine comprising a variable valve timing mechanism with a lock pin that locks in position,
In response to an input of an intermediate lock release request from the outside, an intermediate lock release command for pulling out a lock pin penetrating from one of the two members to the other is output to the valve timing variable mechanism,
After the output of the intermediate lock release command, the valve timing variable mechanism is controlled so that the rotational phase difference between the two members becomes a predetermined target rotational phase difference,
Detecting an actual rotational phase difference between the two members;
After controlling the valve timing variable mechanism so that the rotational phase difference between the two members becomes a predetermined target rotational phase difference, the difference between the actual rotational phase difference and the target rotational phase difference does not become a predetermined value or less. And is configured to determine that the intermediate unlock has not been completed,
The target rotational phase difference is set to a rotational phase difference angle from the intermediate lock position corresponding to a minimum deviation of the rotational phase difference capable of determining that the actual rotational phase difference is different from the target rotational phase difference. A valve timing control device for an internal combustion engine.   The valve timing control device for an internal combustion engine according to claim 1, wherein the target rotational phase difference is set at a position shifted from the intermediate lock position toward the retard side.   The two members and the lock pin are members for controlling the valve timing of the intake valve of the internal combustion engine. When the intermediate lock release is not completed, the operation of the valve timing of the exhaust valve is prohibited. The valve timing control apparatus for an internal combustion engine according to claim 1 or 2, further configured.   After controlling the valve timing variable mechanism so that the rotational phase difference between the two members becomes a predetermined target rotational phase difference, the actual rotational phase difference and the target rotational phase difference are not affected even after a predetermined time has elapsed. The valve timing control device for an internal combustion engine according to any one of claims 1 to 3, further configured to determine that the intermediate unlocking is not completed when the difference is equal to or greater than a predetermined value.

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