JP6220297B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine having a variable compression ratio mechanism.

  In the control of the variable compression ratio mechanism, as described in Japanese Patent Application Laid-Open No. 2006-226133 (Patent Document 1), a compression ratio sensor that detects the compression ratio from the rotation angle of the control shaft of the multi-link mechanism is used. Yes. Since the compression ratio sensors vary, the technology learns the reference position by abutting the mechanism member against the stopper when the engine is stopped.

JP 2006-226133 A

  Incidentally, the compression ratio sensor includes a relative angle sensor that detects a relative angle of the actuator and an absolute angle sensor that detects an absolute angle of the control shaft. The controller of the variable compression ratio mechanism controls the actuator based on the reference position learned when the engine is stopped. In this case, for example, if the absolute angle sensor causes an offset failure between the stop and restart of the engine, the reference position at the start of the engine is shifted, and the compression ratio becomes the target compression ratio according to the engine operating state. It becomes difficult to control. If the compression ratio cannot be controlled to the target compression ratio, for example, problems such as interference between the valve and the piston or a decrease in drivability occur.

  Therefore, an object of the present invention is to provide a control device for an internal combustion engine that can review the reference position when the engine is started.

Therefore, the internal combustion engine changes the compression ratio at least one of the variable compression ratio mechanism that changes the combustion chamber volume and makes the compression ratio variable, and the upper and lower limits of the variable range of the compression ratio by the variable compression ratio mechanism. A stopper mechanism for restricting the displacement of the mechanism member accompanying the above, and a compression ratio sensor for detecting the compression ratio. The control device for the internal combustion engine learns the reference position of the mechanism member based on the output value of the compression ratio sensor when the mechanism member is stopped by the stopper mechanism when the internal combustion engine is stopped, and the compression ratio of the internal combustion engine. Is changed to the target compression ratio when the engine is restarted. Further, the control device for the internal combustion engine includes an output value of the compression ratio sensor in a state where the target compression ratio is changed when the internal combustion engine is stopped, and an output of the compression ratio sensor when the internal combustion engine is restarted. when the value, deviation is less than a predetermined value, re-learning the reference position of the mechanism member.

  According to the present invention, the reference position can be reviewed when the engine is started.

1 is a system diagram illustrating an example of an internal combustion engine for a vehicle. It is the elements on larger scale which show an example of a stopper mechanism. It is a flowchart which shows an example of a reference | standard position learning process. It is a time chart which shows an example of an effect | action of a reference | standard position learning process. It is a time chart which shows an example of compression ratio control at the time of a sensor normal. It is a flowchart which shows an example of a reference | standard position review process. It is a flowchart which shows an example of an effect | action of a reference | standard position review process.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows an example of an internal combustion engine for a vehicle.

  The internal combustion engine 100 includes a cylinder block 110, a piston 120 fitted in a cylinder bore 112 of the cylinder block 110 so as to be reciprocable, a cylinder head 130 having an intake port 130A and an exhaust port 130B, an intake port 130A, an exhaust port An intake valve 132 and an exhaust valve 134 that open and close the opening end of the port 130B are provided.

  The piston 120 is connected to the crankshaft 140 via a connecting rod (connecting rod) 150 including a lower link 150A and an upper link 150B. A combustion chamber 160 is formed between the crown surface 120 </ b> A of the piston 120 and the lower surface of the cylinder head 130. An ignition plug 170 that ignites an air-fuel mixture of fuel and air is attached to substantially the center of the cylinder head 130 that forms the combustion chamber 160.

  Further, the internal combustion engine 100 changes the compression ratio by changing the volume of the variable valve timing (VTC: Valve Timing Control) mechanism 180 that changes the phase with respect to the crankshaft 140 during the opening period of the intake valve 132 and the combustion chamber 160. And a variable compression ratio (VCR) mechanism 190.

  The VTC mechanism 180 changes the phase of the intake camshaft 200 with respect to the crankshaft 140 by an actuator such as an electric motor, for example, so that the operation angle of the intake valve 132 remains constant, and the central phase of the operation angle is advanced. Or retard.

  The VCR mechanism 190 changes the compression ratio of the internal combustion engine 100 by changing the volume of the combustion chamber 160 by a multi-link mechanism as disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-276446. Hereinafter, an example of the VCR mechanism 190 will be described.

  The crankshaft 140 has a plurality of journal portions 140A and a crankpin portion 140B, and the journal portion 140A is rotatably supported by a main bearing (not shown) of the cylinder block 110. The crankpin portion 140B is eccentric from the journal portion 140A, and a lower link 150A is rotatably connected thereto. Upper link 150B has a lower end side rotatably connected to one end of lower link 150A by connecting pin 152, and an upper end side rotatably connected to piston 120 by piston pin 154. The upper end side of the control link 192 is rotatably connected to the other end of the lower link 150 </ b> A by a connecting pin 194, and the lower end side is rotatably connected to the lower portion of the cylinder block 110 via the control shaft 196. Specifically, the control shaft 196 is rotatably supported by the engine body (cylinder block 110) and has an eccentric cam portion 196A that is eccentric from the center of rotation, and the eccentric cam portion 196A includes a control link 192. A lower end part fits rotatably. The rotation position of the control shaft 196 is controlled by a compression ratio control actuator 198 using an electric motor.

  In the VCR mechanism 190 using such a multi-link mechanism, when the control shaft 196 is rotated by the compression ratio control actuator 198, the center position of the eccentric cam portion 196A, that is, relative to the engine body (cylinder block 110). The position changes. As a result, when the peristaltic support position at the lower end of the control link 192 changes, the position of the piston 120 at the piston top dead center (TDC) increases or decreases, the volume of the combustion chamber 160 increases or decreases, and the internal combustion engine 100 The compression ratio is changed. At this time, when the operation of the compression ratio control actuator 198 is stopped, the control link 192 rotates with respect to the eccentric cam portion 196A of the control shaft 196 by the reciprocation of the piston 120, and the compression ratio shifts to the low compression side. .

  As shown in FIG. 2, the VCR mechanism 190 is provided with a stopper mechanism 210 that restricts displacement (rotation) when the control shaft 196 rotates beyond the normal control range. The stopper mechanism 210 includes a substantially fan-shaped first member 210 </ b> A whose main part is fixed to the control shaft 196, and a plate-shaped second member 210 </ b> B fixed to the cylinder block 110. The first member 210A rotates integrally with the control shaft 196. The second member 210B defines the central angle of the first member 210A when the control shaft 196 rotates beyond the maximum compression ratio (upper limit) and the minimum compression ratio (lower limit), which are normal control ranges. It abuts the side and restricts displacement of the control shaft 196, which is an example of a mechanism member. Here, since the stopper mechanism 210 functions when the control shaft 196 exceeds the normal control range, in the normal control, the first member 210A and the second member 210B do not contact each other. Generation of abnormal noise can be suppressed. The stopper mechanism 210 is used to learn the reference position of the control shaft 196, as will be described later.

  The stopper mechanism 210 only needs to be able to regulate the displacement of at least one of the highest compression ratio side and the lowest compression ratio side with respect to the rotation of the control shaft 196. In addition, the stopper mechanism 210 is not limited to the substantially fan-shaped first member 210A and the plate-shaped second member 210B, and it is sufficient that the displacement of the control shaft 196 can be restricted by two members having other shapes.

  The VTC mechanism 180 and the VCR mechanism 190 are electronically controlled by a VTC controller 220 and a VCR controller 230, each including a processor such as a microcomputer. The VTC controller 220 and the VCR controller 230 are connected to an engine controller 250 including a processor such as a microcomputer that electronically controls the internal combustion engine 100 via a CAN (Controller Area Network) 240 which is an example of an in-vehicle network. ing. Therefore, arbitrary data can be transmitted and received between the VTC controller 220, the VCR controller 230, and the engine controller 250 via the CAN 240. In addition, as a vehicle-mounted network, not only CAN240 but well-known networks, such as FlexRay (trademark), can be used.

  The engine controller 250 receives output signals of a rotation speed sensor 260 that detects the rotation speed Ne of the internal combustion engine 100 and a load sensor 270 that detects the load Q of the internal combustion engine 100 as an example of the operating state of the internal combustion engine 100. Have been entered. Here, as the load Q of the internal combustion engine 100, for example, a state quantity closely related to the torque, such as an intake negative pressure, an intake air flow rate, a supercharging pressure, an accelerator opening, and a throttle opening can be used. The engine controller 250 refers to, for example, a map in which target values suitable for the rotational speed and load are set, and the target angle of the VTC mechanism 180 and the VCR mechanism 190 according to the rotational speed Ne and load Q of the internal combustion engine 100. Each target compression ratio is calculated. Then, the engine controller 250 transmits the target angle and the target compression ratio to the VTC controller 220 and the VCR controller 230 via the CAN 240, respectively.

  The VTC controller 220 that has received the target angle controls the drive current output to the actuator of the VTC mechanism 180 so that the actual angle (actual angle) detected by a sensor (not shown) converges to the target angle. In addition, the VCR controller 230 that has received the target compression ratio outputs to the compression ratio control actuator 198 of the VCR mechanism 190 so that an actual compression ratio (actual compression ratio) detected by a sensor described later converges to the target compression ratio. To control the driving current. By doing so, the VTC mechanism 180 and the VCR mechanism 190 are controlled to target values corresponding to the operating state of the internal combustion engine 100.

  The compression ratio sensor that detects the actual compression ratio of the internal combustion engine 100 includes a relative angle sensor 280 that detects the relative angle θr of the output shaft of the compression ratio control actuator 198, and a speed reducer for the output shaft of the compression ratio control actuator 198. And an absolute angle sensor 290 that detects an absolute angle θa of the control shaft 196 connected via the control shaft 196. Here, the relative angle sensor 280 is built in the compression ratio control actuator 198 and detects the rotation angle of the output shaft in the range of 0 to 360 °. The VCR controller 230 learns the reference position using the output value of the absolute angle sensor 290 during self-shutdown when the engine is stopped, and considers the reference position using the output value of the absolute angle sensor 290 at the time of engine start as a base point. However, the rotation angle of the control shaft 198, that is, the compression ratio of the internal combustion engine 100 is detected from the output value of the relative angle sensor 280. This is because the relative angle sensor 280 has high resolution, for example, it cannot distinguish between 0 ° and 360 ° of the same phase, and the absolute angle sensor 290 can detect the absolute angle of the control shaft 196, but the resolution Is low.

  Next, a method for reviewing the reference position of the control shaft 196 when starting the engine and re-learning the reference position as necessary will be described. Here, the VCR controller 230 executes various processes described below in accordance with a control program stored in a non-volatile memory such as a flash ROM (Read Only Memory).

  FIG. 3 shows an example of a reference position learning process executed by the VCR controller 230 during self-shutdown when a reference position learning request is received from the engine controller 250 when the ignition switch is turned from ON to OFF. Show. Note that the VCR controller 230 also receives the target compression ratio upon restart from the engine controller 250.

  In step 1 (abbreviated as “S1” in the figure, the same applies hereinafter), the processor of the VCR controller 230 outputs a drive signal to the compression ratio control actuator 198 of the VCR mechanism 190, for example, thereby compressing the internal combustion engine 100. The compression ratio control actuator 198 is rotated so that the ratio is shifted to the high compression ratio side. At this time, the processor of the VCR controller 230 controls the rotation of the compression ratio control actuator 198 by speed feedback control (the same applies hereinafter).

  In step 2, the processor of the VCR controller 230 determines whether or not the compression ratio control actuator 198 has stopped, for example, based on whether or not the output value of the relative angle sensor 280 has changed. When the compression ratio control actuator 198 stops, the first member 210A of the stopper mechanism 210 comes into contact with the second member 210B, and the displacement of the control shaft 196 to the high compression ratio side is restricted. If the processor of the VCR controller 230 determines that the compression ratio control actuator 198 has stopped, the process proceeds to step 3 (Yes), while if it determines that the compression ratio control actuator 198 has not stopped, the process proceeds to step 3. Return to 1 (No).

  In step 3, the processor of the VCR controller 230 determines whether or not a first predetermined time has elapsed since the compression ratio control actuator 198 stopped using, for example, a built-in timing function. Here, the first predetermined time is to secure a time until the displacement of the control shaft 196 to the high compression ratio side is surely regulated. For example, the first predetermined time is an output of the compression ratio control actuator 198. It can be set as appropriate according to the characteristics and reduction ratio. The processor of the VCR controller 230 proceeds to step 4 if it is determined that the first predetermined time has elapsed (Yes), but waits if it is determined that the first predetermined time has not elapsed (No). .

  In step 4, the processor of the VCR controller 230 stores the output value of the absolute angle sensor 290 in a nonvolatile memory. That is, in the state where the first member 210A of the stopper mechanism 210 is pressed against the second member 210B, the absolute angle of the control shaft 196 can be uniquely specified. Therefore, the output value of the absolute angle sensor 290 in that state is determined. Learning as a reference position.

  In step 5, the processor of the VCR controller 230 sets a learning completion flag indicating that the learning of the reference position is completed. Thereby, an external controller that can refer to the learning completion flag can recognize that the VCR mechanism 190 can be controlled.

  In Step 6, the processor of the VCR controller 230 changes the compression ratio of the internal combustion engine 100 to the target compression ratio at the time of restart by outputting a drive signal to the compression ratio control actuator 198 of the VCR mechanism 190, for example. At this time, the processor of the VCR controller 230, for example, compresses the compression ratio control actuator by PDI control so that the actual compression ratio grasped from the output values of the relative angle sensor 280 and the absolute angle sensor 290 converges to the target compression ratio. The drive signal 198 is controlled (the same applies hereinafter).

  In step 7, the processor of the VCR controller 230 determines whether or not a second predetermined time has elapsed since the compression ratio of the internal combustion engine 100 was changed to the target compression ratio using, for example, a built-in timing function. To do. Here, the second predetermined time is a time for ensuring that the actual compression ratio of the internal combustion engine 100 is converged to the target compression ratio. For example, the output characteristic and deceleration of the compression ratio control actuator 198 are reduced. It can be set as appropriate according to the ratio. The processor of the VCR controller 230 advances the process to step 8 if it is determined that the second predetermined time has elapsed (Yes), but waits if it is determined that the second predetermined time has not elapsed (No). .

  In step 8, the processor of the VCR controller 230 stores the output value of the absolute angle sensor 290, that is, the compression ratio changed in preparation for the restart of the internal combustion engine 100 in the nonvolatile memory.

  According to the reference position learning process, as shown in FIG. 4, when the engine controller 250 makes a reference position learning request when the ignition switch is turned from ON to OFF, the control shaft 196 of the VCR mechanism 190 is highly compressed. Rotating to the specific side, the output value of the absolute angle sensor 290 begins to gradually change toward the displacement regulating position on the high compression ratio side. When the first predetermined time elapses in a state where the first member 210A of the stopper mechanism 210 is in contact with the second member 210B, that is, in a state where displacement toward the high compression ratio is restricted, the absolute angle sensor 290 is detected. Are learned (stored) as reference positions. When the learning of the reference position is completed, a learning completion flag indicating that the learning of the reference position is completed is set, and then the compression ratio of the internal combustion engine 100 is changed to the target compression ratio at the time of restart.

  Therefore, during the self-shutdown, the output value of the absolute angle sensor 290 is learned as the reference position in a state where the displacement of the control shaft 196 of the VCR mechanism 190 to the high compression ratio side is restricted. For this reason, even if there is a variation in the absolute angle sensor 290, the actual compression ratio can be detected from the output value of the relative angle sensor 280 using the reference position learned during the self-shutdown. Detection accuracy can be improved. Further, since the compression ratio of the internal combustion engine 100 is changed to the target compression ratio at the time of restart, it is possible to shorten the time required for restart while ensuring restartability of the internal combustion engine 100.

  When there is no abnormality in the absolute angle sensor 290, as shown in FIG. 5, when the ignition switch is turned on, when the power of the VCR controller 230 is turned on, the starter cranking is performed and the internal combustion engine 100 is turned on. The process shifts to normal control in which the compression ratio is changed according to the operating state. In the normal control, the VCR controller 230 controls the drive signal of the compression ratio control actuator 198 of the VCR mechanism 190 according to the target compression ratio (target angle) transmitted from the engine controller 250. At this time, the VCR controller 230 controls the compression ratio of the internal combustion engine 100 within a control range defined by the maximum compression ratio and the minimum compression ratio, and suppresses, for example, the generation of noise due to the operation of the stopper mechanism 210. . The actual compression ratio controlled by the VCR mechanism 190 changes with a delay from the target compression ratio, so that the output value of the absolute angle sensor 290 changes with a predetermined control delay as shown in FIG.

  FIG. 6 shows an example of the reference position review process executed by the VCR controller 230 when the ignition switch is turned from OFF to ON. Note that the VCR controller 230 repeats a compression ratio changing process (not shown) every predetermined time following the reference position review process, and appropriately changes the compression ratio according to the operating state of the internal combustion engine 100.

  In step 11, the processor of the VCR controller 230 determines the deviation (output) between the output value of the absolute angle sensor 290 indicating the compression ratio at the time of restart stored in the reference position learning process and the current output value of the absolute angle sensor 290. It is determined whether or not (value deviation) is greater than or equal to a first predetermined value. Here, the first predetermined value is a threshold value for determining whether an abnormality such as an offset failure has occurred in the absolute angle sensor 290 during the period from when the internal combustion engine 100 is stopped to when it is restarted. Thus, for example, it can be set appropriately in consideration of the resolution and variation of the absolute angle sensor 290. If the processor of the VCR controller 230 determines that the output value deviation is greater than or equal to the first predetermined value, the process proceeds to step 2 (Yes). On the other hand, if the processor of the VCR controller 230 determines that the output value deviation is less than the first predetermined value (No), it can be determined that no abnormality has occurred in the absolute angle sensor 290, so the process proceeds to normal processing. Therefore, the reference position review process is terminated.

  In step 12, the processor of the VCR controller 230 clears the learning completion flag, that is, resets the learning completion flag to a state where learning of the reference position is not completed. Thus, an external controller that can refer to the learning completion flag can recognize that the VCR mechanism 190 cannot be controlled.

  In step 13, the processor of the VCR controller 230 outputs a drive signal to the compression ratio control actuator 198 of the VCR mechanism 190, for example, so that the compression ratio of the internal combustion engine 100 is shifted to the high compression ratio side. The control actuator 198 is rotated. That is, since there is a possibility that an abnormality has occurred in the absolute angle sensor 290, preparations for restricting the displacement of the control shaft 196 to the high compression ratio side by the stopper function 210 are started in order to execute the reference position learning again. To do.

  In step 14, the processor of the VCR controller 230 determines whether there is a correlation between the output value of the relative angle sensor 280 and the output value of the absolute angle sensor 290. That is, the change characteristic (for example, inclination) of the output value of the relative angle sensor 280 is substantially the same as the change characteristic (for example, inclination) of the output value of the absolute angle sensor 290 in consideration of the reduction ratio of the compression ratio control actuator 198. It is considered the same. Therefore, for example, the processor of the VCR controller 230 compares the output value change of the relative angle sensor 280 with the output value change of the absolute angle sensor 290 to determine whether there is a correlation between the two. be able to. If the processor of the VCR controller 230 determines that the output value of each sensor is correlated, the process proceeds to step 15 (Yes), while if the output value of each sensor determines that there is no correlation, the process is performed. To step 18 (No).

  In step 15, the processor of the VCR controller 230 determines whether or not the compression ratio control actuator 198 has stopped, for example, based on whether or not the output value of the relative angle sensor 280 has changed. If the processor of the VCR controller 230 determines that the compression ratio control actuator 198 has stopped, the process proceeds to step 16 (Yes), while if it determines that the compression ratio control actuator 198 has not stopped, the process proceeds to step 16. Return to 13 (No).

  In step 16, the processor of the VCR controller 230 determines whether or not a first predetermined time has elapsed since the compression ratio control actuator 198 stopped using, for example, a built-in timing function. The processor of the VCR controller 230 proceeds to step 17 if it is determined that the first predetermined time has elapsed (Yes), but waits if it is determined that the first predetermined time has not elapsed (No). .

  In step 17, the processor of the VCR controller 230 determines a deviation (reference) between the output value of the absolute angle sensor 290 at the reference position stored in the reference position learning process and the output value of the absolute angle sensor 290 at the current reference position. It is determined whether or not (position deviation) is equal to or greater than a second predetermined value. Here, the second predetermined value is a threshold value for determining whether or not an abnormality such as an offset failure has occurred in the absolute angle sensor 290 during the period from when the internal combustion engine 100 is stopped to when it is restarted. Thus, for example, it can be set appropriately in consideration of the resolution and variation of the absolute angle sensor 290. If the processor of the VCR controller 230 determines that the reference position deviation is greater than or equal to the second predetermined value, the process proceeds to step 18 (Yes), while the reference position deviation is less than the second predetermined value. If determined, the process proceeds to Step 20 (No).

  In step 18, the processor of the VCR controller 230 sets an abnormality diagnosis flag indicating that an abnormality has occurred in the absolute angle sensor 290. Thereby, an external controller that can refer to the abnormality diagnosis flag can recognize that the VCR mechanism 190 may not be normally controlled.

  In step 19, the processor of the VCR controller 230 ignores the output value of the absolute angle sensor 290 and re-learns the reference position. That is, in the state where the first member 210A of the stopper mechanism 210 is pressed against the second member 210B, the absolute angle of the control shaft 196 can be uniquely specified as described above. Then, learning is performed to set the absolute angle of the control shaft 196 in that state to 0 °.

  In step 20, the processor of the VCR controller 230 changes the compression ratio of the internal combustion engine 100 to the target compression ratio by outputting a drive signal to the compression ratio control actuator 198 of the VCR mechanism 190, for example.

  In step 21, the processor of the VCR controller 230 sets the learning completion flag, that is, changes the learning completion flag to a state where learning of the reference position is completed. Thereby, an external controller that can refer to the learning completion flag can recognize that the VCR mechanism 190 can be controlled.

  According to the reference position review process, as shown in FIG. 7, when the power is turned on when the ignition switch is turned on, the compression ratio at restart stored in the reference position learning process is stored. The output value of the absolute angle sensor 290 shown is compared with the current output value of the absolute angle sensor 290. For example, when an offset failure occurs in the absolute angle sensor 290 between the stop and restart of the internal combustion engine 100, the current output value of the absolute angle sensor 290 is the value of the absolute angle sensor 290 stored in the reference position learning process. A value different from the output value is shown. For this reason, it can be diagnosed that abnormality may have occurred in the absolute angle sensor 290 via the output value deviation of the absolute angle sensor 290.

  When it is diagnosed that there is a possibility that an abnormality has occurred in the absolute angle sensor 290, the control shaft 196 of the VCR mechanism 190 rotates to the high compression ratio side, and the output values of the relative angle sensor 280 and the absolute angle sensor 290 are output. Gradually begins to change toward the displacement restriction position on the high compression ratio side. Then, when the first predetermined time elapses in a state where the first member 210A of the stopper mechanism 210 is in contact with the second member 210B, that is, in a state where displacement to the high compression ratio side is restricted, the reference position learning process is performed. The output value of the absolute angle sensor 290 at the reference position memorized in FIG. 6 is compared with the output value of the absolute angle sensor 290 at the current reference position. In a state where the displacement toward the high compression ratio is restricted, the reference position deviation is within a predetermined range unless an abnormality occurs in the absolute angle sensor 290. Therefore, a diagnosis that there is a possibility that an abnormality has occurred in the absolute angle sensor 290 can be confirmed via the reference position deviation of the absolute angle sensor 290. In short, the abnormality of the absolute angle sensor 290 is not diagnosed with a single diagnosis result, but the abnormality of the absolute angle sensor 290 is diagnosed with a plurality of diagnosis results in different states. In this way, for example, even if the output value of the absolute angle sensor 290 does not show a correct value due to noise superimposition or the like, it is possible to suppress diagnosing this as an abnormality.

  At this time, if there is no correlation between the change characteristic of the output value of the relative angle sensor 280 and the change characteristic of the output value of the absolute angle sensor 290, even if the reference position deviation is less than the second predetermined value, absolute The diagnosis that the abnormality may have occurred in the angle sensor 290 is confirmed. In other words, even if an abnormality occurs in the absolute angle sensor 290, in view of the possibility that the reference position deviation will be less than the second predetermined value due to some cause, an abnormality is caused by the establishment of other conditions to eliminate this. Confirm the occurrence. On the other hand, when the absolute angle sensor 290 is normal, for example, when the actual compression ratio has changed while the internal combustion engine 100 is stopped, the change characteristic of the output value of the relative angle sensor 280 and the output value of the absolute angle sensor 290. Therefore, it is possible to suppress erroneous diagnosis that an abnormality has occurred in the absolute angle sensor 290.

  When the abnormality of the absolute angle sensor 290 is confirmed, an abnormality diagnosis flag is set, and the reference position of the control shaft 196 is learned as 0 ° in a state where the displacement to the high compression ratio side is restricted. . Therefore, in the VCR controller 230, when the abnormality diagnosis flag is set, the output value of the absolute angle sensor 290 is ignored, and the compression ratio of the internal combustion engine 100 is calculated from the reference position and the output value of the relative angle sensor 280. Is detected.

  In this way, even if an abnormality occurs in the absolute angle sensor 290 between the stop and restart of the internal combustion engine 100, the absolute angle of the control shaft 196 can be detected. Interference between the control shaft 196 and the stopper mechanism 210, drivability degradation, and the like can be suppressed.

  Here, technical ideas other than the claims that can be grasped from the above embodiment will be described together with effects.

(A) Deviation between the output value of the compression ratio sensor when the internal combustion engine is stopped and the target compression ratio is changed to the target compression ratio when starting the engine, and the output value of the compression ratio sensor when the internal combustion engine is restarted The control of the internal combustion engine according to any one of claims 1 to 3, wherein it is determined that there is a possibility that an abnormality has occurred in the compression ratio sensor when is equal to or greater than a predetermined value. apparatus.
In this way, it is possible to determine whether there is a possibility that an abnormality has occurred in the compression ratio sensor based on the deviation of the output value of the compression ratio sensor when the internal combustion engine is stopped and restarted.

(B) The compression ratio sensor includes a relative angle sensor that detects a relative angle of an output shaft of an actuator that rotates the mechanism member, and an absolute angle sensor that detects an absolute angle of the mechanism member. The control device for an internal combustion engine according to any one of claims 1 to 3, and (a).
In this way, the accuracy of the compression ratio sensor can be ensured.

(C) When the internal combustion engine is restarted, there is a deviation between a change in the output value of the relative angle sensor and a change in the output value of the absolute angle sensor in the process of shifting the mechanism member to a state stopped by the stopper mechanism. The control apparatus for an internal combustion engine according to (b), wherein when the compression ratio sensor is not less than a predetermined value, it is diagnosed that the compression ratio sensor is abnormal.
In this way, it is possible to diagnose whether or not the compression ratio sensor is abnormal according to changes in the output values of the relative angle sensor and the absolute angle sensor.

(D) The stopper mechanism restricts displacement of the mechanism member when the compression ratio of the internal combustion engine is changed beyond a normal control range. ), (B) and (c) The control apparatus for an internal combustion engine according to any one of the above.
In this way, when the compression ratio of the internal combustion engine is controlled within the normal control range, the stopper mechanism does not operate, and therefore, for example, abnormal noise that the mechanism member contacts the stopper mechanism can be suppressed.

DESCRIPTION OF SYMBOLS 100 Internal combustion engine 160 Combustion chamber 190 VCR mechanism 210 Stopper mechanism 230 VCR controller (control apparatus)
280 Relative angle sensor 290 Absolute angle sensor

Claims (3)

A variable compression ratio mechanism that varies the compression ratio by changing the volume of the combustion chamber;
A stopper mechanism for restricting displacement of the mechanism member accompanying the change of the compression ratio at at least one of the upper limit and the lower limit of the variable range of the compression ratio by the variable compression ratio mechanism;
A compression ratio sensor for detecting the compression ratio;
An internal combustion engine control device comprising:
When the internal combustion engine is stopped , the reference position of the mechanism member is learned based on the output value of the compression ratio sensor in a state where the mechanism member is stopped by the stopper mechanism, and the compression ratio of the internal combustion engine is re-engineered. When the internal combustion engine is restarted , the output value of the compression ratio sensor is changed to the target compression ratio when the internal combustion engine is stopped, and the internal combustion engine is restarted. wherein an output value of the compression ratio sensor, the deviation of at least a predetermined value, re-learning the reference position of the mechanism member in,
A control device for an internal combustion engine. When the learning result of the reference position of the mechanism member is different from the output value of the compression ratio sensor in the state where the mechanism member is stopped by the stopper mechanism when the internal combustion engine is stopped last time or more than the predetermined value, Diagnosing that the compression ratio sensor is abnormal,
The control apparatus for an internal combustion engine according to claim 1. The compression ratio sensor includes a relative angle sensor that detects a relative angle of an output shaft of an actuator that rotates the mechanism member, and an absolute angle sensor that detects an absolute angle of the mechanism member,
When the internal combustion engine is restarted, the deviation between the change in the output value of the relative angle sensor and the change in the output value of the absolute angle sensor in the process of shifting the mechanism member to the state stopped by the stopper mechanism is greater than or equal to a predetermined value. At the time of diagnosing that the compression ratio sensor is abnormal,
The control apparatus for an internal combustion engine according to claim 1 or 2, characterized by the above.