JP2014206078A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine, which locks a relative rotation phase at either a first phase or a second phase on the delay angle side rather than the first phase, thereby to stop an engine so that, even if an engine is started in the state of a high state of an actual compression ratio, the occurrence of a resultant pre-ignition can be suppressed.SOLUTION: In a valve timing variable mechanism, the relative rotation phase between a housing and a rotor is changed by working oil pressures in an advance angle chamber and a delay angle chamber thereby to change an intake valve timing. The valve timing variable mechanism comprises: a first lock mechanism for locking a relative rotation phase between the housing and the rotor at an intermediate phase; and a second lock mechanism for locking the same at the most delay phase. When the relative rotation phase is locked at an intermediate phase by the first lock mechanism (Step S120: YES) so that the engine is stopped according to the stop demand of the internal combustion engine (Step S130: YES), a cooling treatment for raising the cooling power of the internal combustion engine is executed (Step S140).

Description

  The present invention relates to a control device for controlling an internal combustion engine provided with a variable valve timing mechanism for changing the valve timing of an intake valve.

  In the internal combustion engine described in Patent Document 1, the relative rotation phase between the first rotating body that rotates in conjunction with the rotation of the crankshaft and the second rotating body that rotates together with the intake camshaft is set between the advance chamber and the retard chamber. A variable valve timing mechanism is provided for changing the valve timing of the intake valve by changing the hydraulic pressure. The relative rotation phase between the first rotating body and the second rotating body is locked to an intermediate phase between the most retarded angle phase and the most advanced angle phase by the first lock mechanism, and the most retarded angle by the second lock mechanism. Locked to phase. The first lock mechanism and the second lock mechanism are locked and released by the hydraulic pressure of a hydraulic supply source that supplies hydraulic oil to the advance chamber and the retard chamber. In the control device for an internal combustion engine described in Patent Document 1, when the engine is stopped along with the engine stop operation by the driver, such as an ignition switch OFF operation, the relative rotation phase is locked to the intermediate phase. The engine operation is stopped. On the other hand, at the time of automatic stop in which the engine operation is stopped with the establishment of the stop condition, the engine operation is stopped with the relative rotation phase locked to the most retarded phase. As a result, when the engine is stopped with the engine stop operation, that is, when the period from the engine stop to the engine start tends to be long and the cold start is likely to occur, the actual compression ratio at the start is locked by locking to the intermediate phase. It is possible to improve the cold startability by increasing. On the other hand, when the engine is stopped due to automatic stop, that is, when the period from engine stop to engine start is likely to be short and warm start is likely to occur, the actual compression ratio at the start is locked by locking to the most retarded phase. By lowering the value, the occurrence of pre-ignition can be suppressed and the warm startability can be improved.

JP 2012-026275 A

  By the way, if the relative rotation phase is erroneously locked to the intermediate phase during the automatic stop due to an abnormality in the hydraulic pressure supply to the advance and retard chambers of the variable valve timing mechanism and each lock mechanism, There is a possibility that pre-ignition may occur due to a warm start with a high compression ratio. Further, even when the engine is locked to the intermediate phase during the engine stop operation as usual, there is a possibility that pre-ignition may occur as in the case where the period from the engine stop to the engine start is short.

  The present invention has been made in view of the above circumstances, and its purpose is to lock the relative rotational phase to either the first phase and the second phase that is retarded from the first phase and stop the engine. An object of the present invention is to provide a control device for an internal combustion engine that can suppress the occurrence of pre-ignition caused by the engine starting even when the engine is started at a high actual compression ratio.

  An internal combustion engine control apparatus for solving the above-described problem is characterized in that a relative rotational phase between a first rotating body that rotates in conjunction with rotation of a crankshaft and a second rotating body that rotates together with an intake camshaft is determined by an advance chamber and A variable valve timing mechanism is provided to change the valve timing of the intake valve by changing the hydraulic pressure of the retard chamber, and the variable valve timing mechanism has a relative rotation phase between the most retarded angle phase and the most advanced angle phase. A first locking mechanism that locks to one phase; and a second locking mechanism that locks the relative rotational phase to a second phase that is retarded from the first phase. When there is a request to stop the internal combustion engine, when the relative rotation phase is locked to the first phase by the first lock mechanism, a cooling process for increasing the cooling capacity of the internal combustion engine is executed.

  According to the above configuration, when the relative rotation phase is locked to the first phase when there is a request to stop the internal combustion engine, the cooling capacity of the internal combustion engine is increased to decrease the temperature of the internal combustion engine. Therefore, even if the engine is started in a state where the actual compression ratio is high, it is possible to suppress the occurrence of pre-ignition due to the engine starting.

  In addition, an internal combustion engine control apparatus for solving the above-described problems is obtained by calculating a relative rotation phase between a first rotating body that rotates in conjunction with rotation of a crankshaft and a second rotating body that rotates together with an intake camshaft. The valve timing variable mechanism is provided to change the valve timing of the intake valve by changing the hydraulic pressure of the chamber and the retarded angle chamber. The variable valve timing mechanism has a relative rotation phase between the most retarded angle phase and the most advanced angle phase. A first locking mechanism that locks to the first phase and a second locking mechanism that locks the relative rotational phase to the second phase that is retarded from the first phase. Then, when the relative rotation phase is locked to the first phase by the first lock mechanism, the cooling that increases the cooling capacity of the internal combustion engine compared to when the relative rotation phase is locked to the second phase by the second lock mechanism. The process is executed.

  According to the above configuration, the cooling capacity is enhanced when the relative rotational phase is locked to the first phase. For this reason, even if the operation of the internal combustion engine is stopped in such a state that the relative rotation phase is locked to the first phase by the first lock mechanism, the temperature of the internal combustion engine can be lowered. Even if the engine is started in a state where the compression ratio is high, it is possible to suppress the occurrence of pre-ignition due to that.

The internal combustion engine may execute control that automatically stops when the stop condition is satisfied and automatically starts when the start condition is satisfied.
In an internal combustion engine in which control for automatic stop and automatic start is performed, there is a high possibility that the engine is automatically started within a relatively short time from the time of automatic stop. According to the above configuration, even when the relative rotation phase is automatically stopped in a state locked to the first phase, the temperature of the internal combustion engine can be lowered until the automatic start. For this reason, even if the engine is started in a state where the actual compression ratio is high, it is possible to suppress the occurrence of pre-ignition due to that.

  The cooling process may be performed after the relative rotational phase is locked to the first phase and after the engine is stopped, or in a period from when the relative rotational phase is locked to the first phase until the engine is stopped. You may do it. By performing the cooling process at these timings, it is possible to reduce the engine temperature at the time of starting, so that even if the engine is started at a high actual compression ratio, pre-ignition occurs due to that. Can be suppressed.

  For example, the cooling process can be performed by increasing the circulation amount of the cooling water with an electric pump. Further, it is possible to perform the cooling process by circulating the cooling water through the radiator by driving the electric pump and increasing the air volume of the electric fan. In the case where the control valve is provided in the cooling path of the internal combustion engine and adjusts the amount of cooling water passing through the radiator, the control valve is controlled to increase the amount of cooling water passing through the radiator. Processing can be performed.

The cooling process may be performed when the first lock mechanism has an abnormality in which the relative rotation phase is locked to the first phase and cannot be released.
When an abnormality occurs in the first lock mechanism, the relative rotation phase is erroneously locked to the first phase, and there is a high possibility that preignition resulting from the lock occurs.

  According to the above configuration, when the first lock mechanism has an abnormality in which the relative rotational phase is locked to the first phase and cannot be released, the cooling capacity of the internal combustion engine is increased. Even if the engine is started in a high state, it is possible to suitably suppress the occurrence of pre-ignition due to that.

1 is a schematic diagram showing a control device for an internal combustion engine, a variable valve timing mechanism, and a hydraulic circuit for driving the mechanism. The graph which shows the change aspect of the valve timing of an intake valve based on operation | movement of a valve timing variable mechanism. The flowchart which shows the execution procedure of cooling control. (A) is a schematic diagram showing the driving mode of the variable thermostat when the amount of cooling water passing through the radiator decreases, and (b) shows the driving mode of the variable thermostat when the amount of cooling water passing through the radiator is increased. Schematic. The flowchart which shows the execution procedure of other cooling control.

Hereinafter, an embodiment of a control device for an internal combustion engine will be described with reference to FIGS.
As shown in FIG. 1, a variable valve timing mechanism 10 that varies the opening and closing timing of an intake valve of an internal combustion engine includes a rotor 11 (second rotating body) that is fixed to an intake camshaft 21 so as to be integrally rotatable. Is provided. Further, the variable valve timing mechanism 10 is provided with a housing 12 (first rotating body) that is provided so as to surround the rotor 11 on the same axis as the intake camshaft 21 and rotates in conjunction with the rotation of the crankshaft. Yes. A plurality of protrusions 13 projecting toward the axis of the intake camshaft 21 are formed on the inner peripheral surface of the housing 12 at predetermined intervals in the circumferential direction. A plurality of vanes 14 projecting in the radial direction are formed between the plurality of protrusions 13 on the outer peripheral surface of the rotor 11. Thereby, a portion between the protrusions 13 in the housing 12 is partitioned into an advance chamber 15 and a retard chamber 16 by the vane 14.

  When the oil is supplied to the advance chamber 15 and the oil is discharged from the retard chamber 16, the rotor 11 moves relative to the housing 12 in the clockwise direction in the figure, and the intake camshaft 21 with respect to the crankshaft. The relative rotation phase of the intake valve changes to the advance side, and thereby the valve timing of the intake valve changes to the advance side. When the oil is supplied to the retard chamber 16 and the oil is discharged from the advance chamber 15, the rotor 11 moves relative to the housing 12 in the left rotation direction in the figure, and the crank of the intake camshaft 21 is moved. The relative rotational phase with respect to the shaft changes to the retard side, thereby changing the valve timing of the intake valve to the retard side. In this way, the valve timing variable mechanism 10 is driven to vary the valve timing (opening / closing timing) of the intake valve, so that the valve opening timing and valve closing timing of the valve are maintained while the valve opening period of the intake valve is kept constant. Are both advanced or retarded.

  The variable valve timing mechanism 10 includes a first lock mechanism 17 and a first lock mechanism 17 that can switch between a locked state in which the relative rotational phase between the housing 12 and the rotor 11 is locked and an unlocked state in which the relative rotational phase is unlocked. A two-lock mechanism 18 is provided. Switching between the locked state and the unlocked state in the lock mechanisms 17 and 18 is performed by switching insertion / removal of the lock pin of the rotor 11 with respect to the hole formed in the housing 12 through supply / discharge of oil to / from the release chamber 19. . Specifically, when the lock mechanisms 17 and 18 are in the locked state, the hydraulic pressure in the release chamber 19 decreases through the draining of the oil from the release chamber 19 of the lock mechanisms 17 and 18, thereby forming a hole formed in the housing 12. The lock pin is immersed in On the other hand, when the lock mechanisms 17 and 18 are in the released state, the oil pressure in the release chamber 19 rises through the supply of oil to the release chamber 19 of the lock mechanisms 17 and 18, so that the lock pin is released from the hole formed in the housing. Extracted.

  Oil supply / discharge to the advance chamber 15 and retard chamber 16 of the variable valve timing mechanism 10 and oil supply / discharge to the release chamber 19 of the lock mechanisms 17, 18 are performed by an oil control valve 30 (hereinafter referred to as OCV 30). It is done through driving. The OCV 30 includes, for example, a sleeve and a spool valve provided in the sleeve so as to be movable in the axial direction. Then, the OCV 30 is driven by adjusting the position of the spool valve in the axial direction by the actuator 40. Further, the OCV 30 is provided with a supply oil passage 33 connected to the oil pan 32 via the oil pump 31 and a discharge oil passage 34 for returning oil to the oil pan 32. Further, the OCV 30 includes an advance oil passage 35 connected to the advance chamber 15 of the variable valve timing mechanism 10, a retard oil passage 36 connected to the retard chamber 16, and a release chamber of the lock mechanisms 17 and 18. The release oil passage 39 connected to the connection 19 is connected. Then, when the OCV 30 is driven according to the engine operating state or the like, the oil supply / discharge to / from the advance oil passage 35, the retard oil passage 36, and the release oil passage 39 is switched.

  Driving of the actuator 40 that adjusts the OCV 30 is controlled by the control device 50. Further, in this control device 50, when the engine is stopped, the oil is discharged from the release chamber 19 through the adjustment of the OCV 30, and the lock mechanisms 17 and 18 are switched to the locked state, so that the valve timing of the intake valve is set at the next engine start. The engine is fixed at a timing suitable for starting the engine so as to start the engine well.

  As shown in FIG. 2, when the engine is stopped, the relative rotational phase of the intake camshaft 21 with respect to the crankshaft, that is, the relative rotational phase of the housing 12 and the rotor 11 is between the most retarded angle phase and the most advanced angle phase. Locked to either the intermediate phase (first phase) or the most retarded phase (second phase). For example, when the engine operation is stopped due to the engine stop operation by the driver, such as an ignition switch OFF operation, the relative rotation phase between the housing 12 and the rotor 11 is locked to the intermediate phase by the first lock mechanism 17. The engine operation is stopped in the state. As a result, when the engine is stopped along with the engine stop operation, that is, when the period from the engine stop to the engine start is likely to be long and the cold start is likely to occur, the actual compression ratio at the time of start increases, so the cold Startability can be improved. In the case of automatic stop in which engine operation is stopped when the automatic stop condition is satisfied, the relative rotation phase between the housing 12 and the rotor 11 is locked to the most retarded phase by the second lock mechanism 18. Engine operation is stopped. As a result, when the engine is stopped along with the automatic stop, that is, when the period from the engine stop to the engine start is likely to be short and the warm start is likely to occur, the actual compression ratio at the time of start is reduced, so the pre-ignition Occurrence can be suppressed and warm startability can be improved.

  Further, depending on the control device 50, there is a cooling control that increases the cooling capacity of the internal combustion engine by controlling the driving of the electric pump 45 that circulates the cooling water to the internal combustion engine and the electric fan 46 (FIG. 1) that cools the radiator. Executed. This cooling control will be described below with reference to FIG. This series of cooling control processes is executed after a request to stop the internal combustion engine is made.

  As shown in FIG. 3, when the cooling control is started, it is first determined whether or not an abnormality has occurred in the operation of the OCV 30 (step S110). Here, for example, it can be determined that an abnormality has occurred in the operation of the OCV 30 by determining that the signal line for transmitting the drive signal to the actuator 40 is disconnected. If it is determined that there is no abnormality in the operation of the OCV 30 (step S110: NO), this control is terminated as it is. On the other hand, if it is determined that an abnormality has occurred in the operation of the OCV 30 (step S110: YES), it is determined whether or not the relative rotation phase of the housing 12 and the rotor 11 is locked to the intermediate phase by the first lock mechanism 17. (Step S120). In this step S120, for example, it can be determined whether or not the state is locked to the intermediate phase based on the detected value of the intake cam sensor for detecting the rotation angle (intake cam angle) of the intake camshaft 21. If it is determined that the relative rotational phase is locked to the intermediate phase (step S120: YES), it is determined whether or not the engine has stopped (step S130). The engine stop determined in step S130 includes both cases of an engine stop accompanying an engine stop operation by the driver and an engine stop accompanying the establishment of an automatic stop condition. The determination in step S130 is repeated until the engine is stopped (step S130: NO).

  If it is determined that the engine is stopped (step S130: YES), a cooling process is executed (step S140). In this cooling process, cooling water is circulated from the radiator to the internal combustion engine by the electric pump 45, and the cooling water circulated from the internal combustion engine to the radiator is cooled by the electric fan 46. Then, compared with immediately before the engine is stopped, the circulation amount of the cooling water by the electric pump 45 is increased and the air volume of the electric fan 46 is increased. The cooling process is stopped after being continuously performed for a predetermined period after the engine is stopped. Then, after the cooling process is stopped, the present control is temporarily terminated.

  On the other hand, when it is determined in the variable valve timing mechanism 10 that the relative rotational phase of the housing 12 and the rotor 11 is not locked to the intermediate phase (step S120: NO), this control is terminated as it is. In addition, as a case where a negative determination is made in step S120, the relative rotation phase is locked to the most retarded angle phase by the second lock mechanism 18, or the relative rotation phase is either the intermediate phase or the most retarded angle phase. There is also a case where the relative rotation phase is not locked and the relative rotation phase can be changed. When the phase is locked at the most retarded phase, the electric pump 45 and the electric fan 46 are driven normally, and the driving is stopped when the engine is stopped. That is, when the relative rotation phase is locked to the intermediate phase by the first lock mechanism 17, the internal combustion engine is cooled by the cooling process as compared to when the relative rotation phase is locked to the most retarded phase by the second lock mechanism 18. Ability will be higher.

Next, the operation of the control device 50 will be described.
When the relative rotational phase of the housing 12 and the rotor 11 is locked to the intermediate phase, the engine 12 is locked to the intermediate phase when the engine is stopped by the engine stop operation by the driver. In some cases, the intermediate phase may be erroneously locked due to abnormal operation of the OCV 30 or the like. If the motor is automatically stopped when it is erroneously locked to the intermediate phase in this way, there is a possibility that pre-ignition occurs due to a warm start with a high actual compression ratio. As described above, when the relative rotational phase is locked to the intermediate phase, preignition may occur depending on other conditions.

  In the present embodiment, the operation of the OCV 30 is abnormal, and the relative rotation phase of the housing 12 and the rotor 11 is locked to the intermediate phase by the first lock mechanism 17, that is, the relative rotation phase is the intermediate phase. The cooling process is executed on the condition that the first lock mechanism 17 has an abnormality that is locked and cannot be released. As a result, the internal combustion engine can be cooled when pre-ignition is likely to occur as described above.

  If the cooling process is performed only when the relative rotational phase of the housing 12 and the rotor 11 is locked to the intermediate phase, the relative rotational phase is erroneously locked to the intermediate phase due to an abnormal operation of the OCV 30 or the like. Thus, the cooling process is performed not only in the case of being automatically stopped. That is, the cooling process is performed even when the engine is stopped in accordance with the engine stop operation as usual with the relative rotational phase locked to the intermediate phase regardless of the occurrence of the operation abnormality of the OCV 30 or the like. In addition, since the start after the automatic stop is likely to be a warm start, there is a high possibility that pre-ignition will occur if the start is performed while locked to the intermediate phase. On the other hand, since the start after the engine stop accompanying the engine stop operation is likely to be a cold start, there is a low possibility that pre-ignition will occur even if the engine is started in a state locked to the intermediate phase.

  In the present embodiment, the execution condition of the cooling process includes that an abnormality has occurred in the operation of the OCV 30. As a result, the temperature of the internal combustion engine at the start can be lowered when the intermediate phase is erroneously locked during automatic stop, that is, when the possibility of occurrence of pre-ignition at the start is high. When the engine is locked in accordance with the engine stop operation as usual, when the lock to the intermediate phase is performed, that is, when the possibility of occurrence of pre-ignition at the time of starting is low, it is possible to suppress unnecessary cooling processing. .

According to the control device 50 described above, the following effects can be obtained.
(1) If the relative rotation phase of the housing 12 and the rotor 11 is locked to an intermediate phase when there is a request to stop the internal combustion engine, the cooling capacity of the internal combustion engine is increased, for example, locked to the most retarded phase. Therefore, even if the engine is started in a state where the actual compression ratio is high, the occurrence of pre-ignition caused by it can be suppressed.

  (2) In an internal combustion engine in which control for automatic stop and automatic start is performed, there is a high possibility that the engine will be automatically started within a relatively short time after the automatic stop. Even if the housing 12 and the rotor 11 are automatically stopped with the relative rotational phase locked to the intermediate phase, the temperature of the internal combustion engine can be lowered before the automatic start. For this reason, even if the engine is started in a state where the actual compression ratio is high, it is possible to suppress the occurrence of pre-ignition due to that.

The above-described embodiment can be modified as follows. In addition, the above-described embodiment and the following modifications can be combined as appropriate.
As shown in FIG. 4, instead of the electric pump 45 and the electric fan 46, it is possible to perform the cooling process by controlling a variable thermostat 56 with a heater as a regulating valve. That is, the cooling system is provided with a cooling passage 52 provided with a radiator 51, a variable thermostat 56 that adjusts the amount of cooling water flowing through the cooling passage 52, and a bypass passage 55 that bypasses the radiator 51. . Further, the amount of cooling water that passes through the radiator 51 and is circulated to the internal combustion engine 20 via the pump 57 is adjusted according to the opening of the variable thermostat 56. Then, the variable thermostat 56 adjusts the amount of cooling water normally circulated to the radiator 51 in accordance with the temperature of the cooling water (FIG. 4A). On the other hand, when the cooling process is performed, the heater is controlled by the control device 50, and the opening degree of the variable thermostat 56 is changed by the heater, and the amount of the cooling water circulated to the radiator 51 regardless of the temperature of the cooling water. (Fig. 4 (b)).

-Instead of the variable thermostat 56 shown in FIG. 4, you may make it perform a cooling process by controlling a solenoid valve.
As shown in FIG. 5, the cooling process may be performed before the engine is stopped. That is, on the condition that the operation of the OCV 30 is abnormal (step S210: YES) and the relative rotation phase of the housing 12 and the rotor 11 is locked to the intermediate phase by the first lock mechanism 17 (step S220: YES). Then, a cooling process is executed (step S230). This cooling process is performed by controlling the variable thermostat 56 with a heater shown in FIG. The cooling process is continuously performed during engine operation, and after the engine is stopped (step S240: YES), the cooling process is stopped (step S250). Even if the cooling process is performed at such execution timing, the engine temperature at the time of starting can be lowered. Similarly to FIG. 3, in the cooling control shown in FIG. 5, when the relative rotation phase is locked to the most retarded angle phase by the second lock mechanism 18, the relative rotation phase is the intermediate phase and the most retarded angle phase. Are not locked to each other and the relative rotation phase can be changed (step S220: NO), the control is terminated as it is. When the phase is locked at the most retarded phase, the opening of the variable thermostat 56 is adjusted according to the temperature of the cooling water as usual. That is, when the relative rotation phase is locked to the intermediate phase by the first lock mechanism 17, the internal combustion engine is cooled by the cooling process as compared to when the relative rotation phase is locked to the most retarded phase by the second lock mechanism 18. Ability will be higher.

  In the modification shown in FIG. 5, the cooling process stop timing may be before the engine stop. In short, it is only necessary that the cooling process be performed during the period from when it is determined that the relative rotation phase is locked to the intermediate phase by the first lock mechanism 17 until the engine is stopped. However, in such a form, in order to effectively reduce the engine temperature at the start, it is desirable to execute the cooling process until just before the engine is stopped.

  -The cooling means used in the cooling process can be freely adopted. For example, the cooling process shown in FIG. 3 may be performed using the variable thermostat 56 and the electromagnetic valve shown in FIG. 4, or the electric pump 45 and the electric fan 46 shown in FIG. A cooling process may be performed. In addition, increasing the circulation amount of the cooling water by the electric pump 45, cooling the radiator by increasing the air volume of the electric fan 46, and increasing the amount of the cooling water flowing through the radiator by the variable thermostat 56 as appropriate. You may carry out in combination.

  In the cooling control shown in FIG. 3 and FIG. 5, the determination of whether or not an abnormality has occurred in the operation of the OCV 30 (step S110 in FIG. 3 and step S210 in FIG. 5) may be omitted. According to such a form, although the number of executions of the cooling process increases, the temperature of the internal combustion engine at the time of starting can be reduced when the engine is stopped with the relative rotational phase locked to the intermediate phase. As a result, the occurrence of pre-ignition at the start due to the fact that the relative rotation phase is locked to the intermediate phase under conditions where the engine is stopped due to automatic stop or when the period from engine stop to engine start is short Can be suppressed.

  When determining whether or not to stop the engine shown in FIGS. 3 and 5 (step S130 in FIG. 3 and step S240 in FIG. 5), it may be determined whether the engine stop is due to an automatic stop or an engine stop operation. . If the cooling process is performed only when the engine is stopped by an automatic stop, the relative rotation phase is locked to the intermediate phase and the engine is automatically stopped, that is, when there is a possibility that pre-ignition may occur at the time of starting. The cooling process can be performed appropriately.

  -The 2nd phase locked by the 2nd lock mechanism 18 is good also as a phase from the most retarded phase to the advance side in the range which can suppress the engine vibration at the time of starting by locking to the 2nd phase.

  DESCRIPTION OF SYMBOLS 10 ... Variable valve timing mechanism, 11 ... Rotor, 12 ... Housing, 15 ... Advance angle chamber, 16 ... Delay angle chamber, 17 ... First lock mechanism, 18 ... Second lock mechanism, 19 ... Release chamber, 20 ... Internal combustion engine , 21 ... intake camshaft, 30 ... OCV, 40 ... actuator, 45 ... electric pump, 46 ... electric fan, 50 ... control device, 51 ... radiator, 56 ... variable thermostat.

Claims (9)

The valve timing of the intake valve is determined by changing the relative rotational phase of the first rotating body that rotates in conjunction with the rotation of the crankshaft and the second rotating body that rotates together with the intake camshaft according to the hydraulic pressure in the advance chamber and retard chamber. The valve timing variable mechanism includes a first lock mechanism that locks the relative rotation phase to a first phase between the most retarded angle phase and the most advanced angle phase, and the relative rotation phase. A control device for an internal combustion engine having a second locking mechanism that locks the second phase to the second phase retarded from the first phase,
When there is a request to stop the internal combustion engine, a cooling process for increasing the cooling capacity of the internal combustion engine is executed when the relative rotation phase is locked to the first phase by the first lock mechanism. Control device. The valve timing of the intake valve is determined by changing the relative rotational phase of the first rotating body that rotates in conjunction with the rotation of the crankshaft and the second rotating body that rotates together with the intake camshaft according to the hydraulic pressure in the advance chamber and retard chamber. The valve timing variable mechanism includes a first lock mechanism that locks the relative rotation phase to a first phase between the most retarded angle phase and the most advanced angle phase, and the relative rotation phase. A control device for an internal combustion engine having a second locking mechanism that locks the second phase to the second phase retarded from the first phase,
When the relative rotation phase is locked to the first phase by the first lock mechanism, the cooling capacity of the internal combustion engine is larger than when the relative rotation phase is locked to the second phase by the second lock mechanism. A control device for an internal combustion engine, characterized by executing a cooling process for increasing The control apparatus for an internal combustion engine according to claim 1 or 2, wherein the internal combustion engine is automatically stopped when a stop condition is satisfied, and is automatically started when the start condition is satisfied. The internal combustion engine according to any one of claims 1 to 3, wherein the cooling process is executed on condition that the relative rotation phase is locked to the first phase by the first lock mechanism and the engine is stopped. Control device. The internal combustion engine according to any one of claims 1 to 3, wherein when the relative rotation phase is locked to the first phase by the first lock mechanism, the cooling process is executed during a period until the engine is stopped. Control device. The control device for an internal combustion engine according to any one of claims 1 to 5, wherein the cooling process is performed by increasing a circulation amount of cooling water by an electric pump. The control apparatus for an internal combustion engine according to any one of claims 1 to 6, wherein the cooling process is performed by circulating cooling water through a radiator by driving an electric pump and increasing an air volume of an electric fan. A control valve that is provided in the cooling path of the internal combustion engine and adjusts the amount of cooling water passing through the radiator;
The control device for an internal combustion engine according to any one of claims 1 to 5, wherein the cooling process is performed by controlling the control valve to increase an amount of cooling water passing through the radiator. The said cooling process is performed when the abnormality which the said relative rotation phase is locked to the said 1st phase, and cannot be cancelled | released has arisen in the said 1st lock mechanism. Control device for internal combustion engine.