JP5901402B2 - Control device for internal combustion engine and control method for internal combustion engine - Google Patents

Description

  The present invention relates to a control device and a control method for an internal combustion engine having a supercharger.

  In an internal combustion engine with a supercharger, there is a technique in which an air bypass valve is provided in a bypass passage of an intake passage in order to prevent occurrence of surging during deceleration. As this air bypass valve, an electromagnetic valve 100 as shown in FIG. 18 is used. The electromagnetic valve 100 includes a pressure balance chamber 102, and a pressure adjusting hole 106 that communicates with the pressure balance chamber 102 at the center of the valve body 104. And this hole 106 is also connected also to the sliding part of the bearing 108 and the shaft 110 (fixed shaft). Therefore, the condensed water in the intake passage may enter the sliding portion from the hole 106. As described above, when the temperature becomes low with the condensed water entering the sliding portion, the condensed water freezes and the bearing 108 and the shaft 110 are fixed, so that the armature 112 to which the bearing 108 is fixed moves. The valve body 104 integral with the armature 112 may not operate. Therefore, the solenoid valve 100 cannot function as an air bypass valve until the frozen water of the condensed water is thawed.

  Here, as a technique for performing thawing when such freezing occurs in a control valve such as an electromagnetic valve, there is a technique of Patent Document 1. In the technique of Patent Document 1, when the intake control valve and the bypass valve are frozen, the exhaust control valve is opened by a predetermined opening so as to supply exhaust to the turbine of the second supercharger. Thus, each valve performs thawing.

JP 2010-151085 A

  However, in the technique of Patent Document 1, when it is determined that freezing has occurred in the intake control valve and the bypass valve, the thawing control is executed for a predetermined time, and then whether or not the thawing is confirmed by confirming the operation of the valve. Therefore, the thaw determination in the intake control valve and the bypass valve is not efficiently performed.

  Accordingly, the present invention has been made to solve the above-described problems, and provides an internal combustion engine control apparatus and an internal combustion engine control method capable of efficiently and reliably determining freezing and thawing in an electromagnetic valve. Let it be an issue.

One aspect of the present invention, which has been made to solve the above problems, is a control device for an internal combustion engine , wherein a bypass passage connected to an upstream side and a downstream side of a compressor of a supercharger , and a flow rate of gas flowing through the bypass passage The solenoid valve to be controlled and the steady-state value without decreasing the current value of the drive current after starting energization of the drive current for valve opening to the drive portion of the solenoid valve when the solenoid valve is estimated to be frozen When the current value of the drive current drops below a steady value after performing the freezing determination, the electromagnetic valve is thawed when it is frozen. A freezing and thawing determining means for performing the determination, and when the freezing and thawing determining means is in a non-supercharging region where the supercharger does not perform supercharging after the thawing determination is performed. Scavenging system that controls to scavenge It comprises means, and characterized.

According to this aspect, since the determination of the freezing and thawing of the electromagnetic valve is performed based on the behavior of the current value of the drive current for valve opening, the freezing and thawing of the electromagnetic valve can be determined efficiently and reliably. Further, the condensed water remaining inside the electromagnetic valve can be scavenged. Therefore, it is possible to prevent the solenoid valve from freezing due to the condensed water remaining inside the solenoid valve.

  In the above aspect, it is preferable to interrupt the energization of the drive current when the turbocharger is in a supercharging region where supercharging is performed.

  According to this aspect, it is possible to prevent a decrease in the supercharging pressure in the supercharging region.

  In the above aspect, the scavenging control means is configured to control the electromagnetic wave according to a thawing control time from the start of energization of the drive current until the thawing determination is performed, or a start-up water temperature or an outside air temperature. It is preferable to define the number of times of scavenging the inside of the valve.

  According to this aspect, the condensed water remaining inside the solenoid valve after thawing can be effectively scavenged according to the freezing state of the solenoid valve.

  In the above aspect, the EGR system is configured to recirculate EGR gas from the downstream side of the turbocharger turbine to the upstream side of the compressor, and the scavenging control unit is configured to recirculate the EGR gas by the EGR system. It is preferable to control so that the inside of the electromagnetic valve is scavenged when there is not.

  According to this aspect, when scavenging the inside of the solenoid valve, it is possible to prevent the condensed water contained in the EGR gas from entering the inside of the solenoid valve. Therefore, it is possible to prevent freezing inside the electromagnetic valve due to the condensed water contained in the EGR gas.

  In the above aspect, it is preferable that the scavenging control means performs control so that the interior of the electromagnetic valve is scavenged when the ignition switch is turned off.

  According to this aspect, the condensed water that may exist inside the electromagnetic valve is discharged when the engine is stopped, so that it is possible to prevent the electromagnetic valve from being frozen when the engine is started next time.

Another aspect of the present invention made in order to solve the above-described problem is an internal-combustion-engine control method in which a solenoid valve for controlling a flow rate of a gas flowing in a bypass passage connected to an upstream side and a downstream side of a compressor of a supercharger. When the freezing of the solenoid valve is estimated, the solenoid valve is activated when the current value of the drive current reaches a steady value without decreasing after the start of energization of the drive current for opening the valve to the drive unit of the solenoid valve. was freeze determination that is frozen, have rows decompression determination that the solenoid valve is thawed when the current value of the drive current after the said freezing determination is lower than the steady-state value, the decompression judgment Control is performed so that the inside of the solenoid valve is scavenged after the operation is performed and in a non-supercharging region where supercharging is not performed by the supercharger .

According to this aspect, since the determination of the freezing and thawing of the electromagnetic valve is performed based on the behavior of the current value of the drive current for valve opening, the freezing and thawing of the electromagnetic valve can be determined efficiently and reliably. Another aspect of the present invention, which has been made to solve the above problems, is a control device for an internal combustion engine, wherein a bypass passage connected to an upstream side and a downstream side of a compressor of a supercharger, and a gas flowing through the bypass passage When the solenoid valve that controls the flow rate of the solenoid valve and the supercharger is in a non-supercharge range where supercharging is not performed, the solenoid valve is repeatedly opened and closed to scavenge the interior of the solenoid valve. Scavenging control means for controlling.

  According to the control device and the control method for an internal combustion engine according to the present invention, it is possible to efficiently and reliably determine the occurrence of freezing and the execution of thawing in the electromagnetic valve.

It is a block diagram of the control apparatus of an internal combustion engine. FIG. 3 is a diagram illustrating a routine that is executed in the first embodiment. It is a figure which shows a XABV_cold flag initial set routine. It is a figure which shows a supercharging region determination routine. It is a figure which shows the map used when determining whether an engine driving | running state exists in a supercharging region. FIG. 3 is a time chart diagram of the first embodiment. It is a figure which shows the malfunction by opening an air bypass valve in a supercharging area | region. FIG. 10 is a diagram illustrating a routine executed in the second embodiment. FIG. 10 is a diagram illustrating a routine executed in the second embodiment. It is a figure which shows the map used when calculating | requiring the frequency | count of scavenging of an air bypass valve based on the water temperature at the time of starting. It is a figure which shows the map used when calculating | requiring the frequency | count of scavenging of an air bypass valve based on external temperature. FIG. 6 is a time chart of Example 2. It is a figure which shows the routine performed when an ignition switch is turned off. FIG. 10 is a diagram illustrating a routine that is executed in the third embodiment. FIG. 10 is a diagram illustrating a routine that is executed in a fourth embodiment. It is a figure which shows the map used when calculating | requiring the freezing judgment water temperature based on the water temperature at the time of starting. FIG. 6 is a time chart diagram of Example 4. It is sectional drawing of the solenoid valve conventionally used.

[Configuration of control device for internal combustion engine]
First, the configuration of the control device 1 for an internal combustion engine of the present invention will be described. As shown in FIG. 1, the control device 1 for an internal combustion engine mainly includes an ECU 10, an air filter 12, an intake passage 14, a supercharger 16, an intercooler 18, a throttle valve 20, and an air bypass passage. 22, an air bypass valve 24, an engine (internal combustion engine) 26, an exhaust passage 28, a DPF 30, a muffler 32, an EGR passage 34, an EGR cooler 36, an EGR valve 38, and an LPL-EGR system 40 A water temperature sensor 56 and a supercharging pressure sensor 58.

  The ECU 10 controls the control device 1 of the internal combustion engine, and corresponds to a freeze / thaw determination unit and a scavenging control unit in the present invention.

  As will be described in detail later, the freeze / thaw determination means starts energizing the drive current for opening the valve to the coil 42 of the air bypass valve 24 when it is estimated that the air bypass valve 24 is frozen. After that, when the current value of the drive current for opening the valve reaches a steady value without decreasing, it is determined that the air bypass valve 24 is frozen. Further, as will be described in detail later, the freeze / thaw determination means performs the thawing determination that the air bypass valve 24 has been thawed when the current value of the valve opening drive current decreases after the freeze determination.

  Further, as will be described in detail later, the scavenging control means is an air bypass valve that is in a non-supercharging region after the freeze / thaw determination means performs the thawing determination and is not supercharged by the supercharger 16. The inside of 24 is controlled to be scavenged.

  The air filter 12 purifies air (air, intake air) acquired from the outside and supplies it to the intake passage 14.

  The air bypass passage 22 is connected to the upstream side and the downstream side of the compressor 44 of the supercharger 16.

  The air bypass valve 24 is an electromagnetic valve that controls the flow rate of air flowing through the air bypass passage 22. The air bypass valve 24 is, for example, an electromagnetic valve as shown in FIG.

  The supercharger 16 includes a compressor 44 and a turbine 46. The compressor 44 is provided in the intake passage 14, and the turbine 46 is provided in the exhaust passage 28.

  The intercooler 18 is provided in the intake passage 14 and cools the intake air whose pressure has been increased by the compressor 44 to an appropriate temperature.

  The throttle valve 20 is provided in the intake passage 14 and adjusts the intake air amount by opening and closing in conjunction with the operation of an accelerator pedal (not shown).

  The EGR passage 34 has one end connected to the exhaust passage 28 and the other end connected to the intake passage 14. The EGR passage 34 is a passage for returning exhaust gas (EGR gas) to the intake system. Specifically, an EGR cooler 36 and an EGR valve 38 are provided in the EGR passage 34. The EGR cooler 36 is a device that cools the EGR gas. The EGR valve 38 is a valve that adjusts the flow rate of the EGR gas that passes through the EGR passage 34, and is a valve that adjusts the amount of EGR gas that is recirculated to the intake system.

  The DPF 30 is provided in the exhaust passage 28 and captures PM (Particulate Matter) in the exhaust gas.

  The LPL-EGR system 40 is a system that recirculates EGR gas from the downstream side of the turbine 46 of the supercharger 16 to the upstream side of the compressor 44. The LPL-EGR system 40 mainly includes an EGR passage 48, an EGR cooler 50, an EGR valve 52, and an exhaust throttle valve 54. One end of the EGR passage 48 is connected to the downstream side of the turbine 46 of the supercharger 16 in the exhaust passage 28, and the other end is connected to the upstream side of the compressor 44 of the supercharger 16 in the intake passage 14. The EGR passage 48 is a passage for returning exhaust gas (EGR gas) to the intake system. Specifically, an EGR cooler 50 and an EGR valve 52 are provided in the EGR passage 48. The EGR cooler 50 is a device that cools the EGR gas. The EGR valve 52 is a valve that adjusts the flow rate of EGR gas that passes through the EGR passage 48, and is a valve that adjusts the amount of EGR gas that is recirculated to the intake system.

  The muffler 32 is provided in the exhaust passage 28 and silences the exhaust sound.

[Operation of internal combustion engine controller]
Next, the processing contents of the control of the air bypass valve 24 executed by the ECU 10 will be described in detail as an operation (control method of the internal combustion engine) of the control device 1 for the internal combustion engine. In the following description, the air bypass valve 24 may be expressed as “ABV”. “The air bypass valve 24 is frozen” means that the condensed water that has entered the sliding portion between the bearing 108 (see FIG. 18) and the shaft 110 (see FIG. 18) in the air bypass valve 24 is frozen. This means that the valve body 104 (see FIG. 18) does not operate. Furthermore, “the air bypass valve 24 thawed” means that the frozen body of condensed water at the sliding portion between the bearing 108 and the shaft 110 thawed in the air bypass valve 24 and the valve body 104 was activated. I mean.

<Example 1>
In the first embodiment, the ECU 10 periodically executes the ABV control routine shown in FIG. 2 every predetermined time.

  Therefore, when the processing of the routine shown in FIG. 2 is started, first, the ECU 10 takes in the starting water temperature thws of the engine 26 from the water temperature sensor 56 (step S101) and determines whether or not the deceleration condition is satisfied (step S102). ). That is, the ECU 10 determines whether or not the vehicle is in a deceleration state.

  When the deceleration condition is not satisfied, the ECU 10 determines whether or not the starting water temperature thws is less than 0 ° C. (step S103).

  When the starting water temperature thws is lower than 0 ° C., the air bypass valve 24 is estimated to be frozen. That is, in the air bypass valve 24, as described above, the condensed water that has entered the sliding portion between the bearing 108 (see FIG. 18) and the shaft 110 (see FIG. 18) freezes, and the bearing 108 and the shaft 110 are separated. It is presumed that it is stuck.

  Then, the ECU 10 determines whether or not the ABV freezing initial condition flag XABV_cold is “1” (step S104). In the XABV_cold initial set routine shown in FIG. 3, the ECU 10 sets the ABV freezing initial condition flag XABV_cold to “1” when the ignition switch is turned off (IG_OFF) in step S201. Setting is performed (step S202).

  Returning to the routine shown in FIG. 2 again, if the ABV freezing initial condition flag XABV_cold is “1” in step S104, the ECU 10 determines whether or not the supercharging region determination flag XHi_pm is “0”. (Step S105). That is, the ECU 10 determines whether or not the engine operating state is in the supercharging region.

  Here, the supercharging region determination flag XHi_pm is set by the processing of the supercharger determination routine shown in FIG. As shown in FIG. 4, the ECU 10 first takes in the engine speed Ne and the engine load factor kl (step S301), and the engine operating state is in the supercharging region based on the taken-in engine speed Ne and the engine load factor kl. It is determined whether or not (step S302). Here, when it is determined in step S302 whether the engine operating state is in the supercharging region, a map as shown in FIG. 5 is used. The engine load factor kl can be obtained from the ratio of the actual intake air amount to the maximum intake air amount per cycle at a certain engine speed, for example. If the engine operating state is in the supercharging region in step S302, the ECU 10 sets the supercharging region determination flag XHi_pm to “1” (step S303). On the other hand, if the engine operating state is not in the supercharging region in step S302, the supercharging region determination flag XHi_pm is set to “0” (step S304). As described above, the supercharging region determination flag XHi_pm is set.

  Returning to the routine shown in FIG. 2 again, if the supercharging region determination flag XHi_pm is “0” in step S105, the ECU 10 executes the heating control by energizing the air bypass valve 24 (step S105). S106). That is, the ECU 10 generates heat by energizing the coil (drive unit) 42 of the air bypass valve 24 with a drive current for valve opening.

  Next, the ECU 10 determines whether or not energization to the air bypass valve 24 is initial (step S107). That is, as shown in the rising portion of the ABV drive current immediately after turning on the ignition switch in FIG. 6 described later, the ECU 10 continues to increase the current value of the drive current for opening the valve after the ignition switch is turned on. It is determined whether the steady value has not yet been reached. The steady value of the current value of the drive current for valve opening is a current value when the change in current converges after the start of energization of the coil 42 (see FIG. 18) of the air bypass valve 24.

  If the energization of the air bypass valve 24 is initial in step S107, the ECU 10 takes in the current value change amount Δa (step S108). Here, the current value change amount Δa is a change amount per unit time in the current value of the valve-opening drive current.

  Next, the ECU 10 determines whether or not the current value change amount Δa is smaller than the threshold −A (step S109). Here, the threshold −A is a value for determining a decrease in the current value of the drive current for valve opening. More specifically, the threshold value -A is a threshold value of the current value change amount when the air bypass valve 24 is normally opened.

  If the current value change amount Δa is smaller than the threshold −A in step S109, the ECU 10 sets the ABV freezing initial condition flag XABV_cold to “0” (step S110) and stops energization of the air bypass valve 24. Then, the heating control is stopped (step S111), and the subsequent processing is temporarily ended. That is, when the current value change amount Δa is smaller than the threshold −A in step S109, it is considered that the air bypass valve 24 is normally opened and the air bypass valve 24 is not frozen. Stop control.

  On the other hand, if the current value change amount Δa is greater than or equal to the threshold −A in step S109, the ECU 10 sets the ABV freezing flag XABV_close to “1” (step S112), and the subsequent processing is temporarily ended.

  As shown in FIG. 2, when the deceleration condition is satisfied in step S102, the ECU 10 energizes the air bypass valve 24 (executes deceleration valve opening control) (step S113). That is, when the vehicle is in a decelerating state, the ECU 10 energizes the coil 42 of the air bypass valve 24 with a driving current for valve opening in order to open the air bypass valve 24 and prevent surging. Next, the ECU 10 takes in the current value change amount Δa (step S114), and determines whether or not the current value change amount Δa is smaller than the threshold −A (step S115). If the current value change amount Δa is smaller than the threshold −A in step S115, the ECU 10 sets the ABV freezing initial condition flag XABV_cold to “0” (step S116), and the subsequent processing is temporarily ended. On the other hand, if the current value change amount Δa is greater than or equal to the threshold −A in step S115, the ECU 10 once terminates the subsequent processing.

  Further, as shown in FIG. 2, when the starting water temperature thws is 0 ° C. or higher in step S103, it is difficult to estimate that the air bypass valve 24 is frozen. Therefore, the ECU 10 sets the ABV freezing initial condition flag XABV_cold to “0” (step S117), stops energization of the air bypass valve 24 (interrupts the deceleration valve opening control) (step S118), The subsequent processing is temporarily terminated.

  Further, as shown in FIG. 2, when the ABV freezing initial condition flag XABV_cold is not “1” in step S104, or when the supercharging region determination flag XHi_pm is not “0” in step S105, the ECU 10 The process proceeds to S118.

  As shown in FIG. 2, when the energization of the air bypass valve 24 is not initial in step S107, the ECU 10 takes in the current value change amount Δa (step S119), and the current value change amount Δa is equal to the threshold value −. It is determined whether it is smaller than B (step S120). That is, as shown as a time zone after freezing determination in FIG. 6 to be described later, after the ignition switch is turned on, the current value of the driving current for valve opening has already reached a steady value and the air bypass valve 24 is frozen. Is determined, it is determined whether or not the current value change amount Δa is smaller than the threshold value −B. Here, the threshold value -B is a value for determining a decrease in the current value of the drive current for valve opening. More specifically, the threshold value -B is a threshold value of the current value change amount when the air bypass valve 24 is defrosted and opened. If the current value variation Δa is smaller than the threshold −B in step S120, it is considered that the air bypass valve 24 has been thawed, and the ECU 10 proceeds to the process of step S110. On the other hand, if the current value change amount Δa is greater than or equal to the threshold −B in step S120, the ECU 10 once terminates the subsequent processing.

  The above is the description of the routine shown in FIG.

  Here, in the first embodiment, the ABV freezing initial condition flag XABV_cold, the supercharging region determination flag XHi_pm, the current value change amount Δa, the opening / closing of the ABV, the ABV control voltage signal, and the ABV drive current ( A time chart of the drive current for opening the air bypass valve 24 is shown in FIG.

  First, when the freezing of the air bypass valve 24 is estimated, as shown in FIG. 6, when the ignition switch is turned on, the ECU 10 sets the ABV freezing initial condition flag XABV_cold to “1” and performs ABV control. The voltage signal is set from OFF to ON, and energization to the air bypass valve 24 is started. The time when the air bypass valve 24 is estimated to be frozen is, for example, when the starting water temperature thws is less than 0 ° C. as shown in FIG.

  When the air bypass valve 24 is not frozen and the air bypass valve 24 is normally opened, the armature 112 (see FIG. 18) moves inside the coil 42 (see FIG. 18) to move the coil 42. Since a back electromotive force is generated by an inductive action, as shown by a solid line in FIG. 6, when the ABV drive current rises, the current value of the ABV drive current decreases in the region α, and the current value variation Δa Becomes smaller than the threshold -A. In this case, the ABV freezing initial condition flag XABV_cold is set to “0”, the ABV control voltage signal is set from on to off, and energization to the air bypass valve 24 is stopped.

  On the other hand, when the air bypass valve 24 is frozen, the air bypass valve 24 cannot be opened. Therefore, as shown by the broken line in FIG. 6, the current value of the ABV drive current at the rise of the ABV drive current. Continues to increase without decreasing and reaches a steady value, and the current value variation Δa does not become smaller than the threshold −A. Therefore, the ECU 10 determines that the air bypass valve 24 is frozen based on such behavior of the ABV drive current and the current value change amount Δa.

  Then, after performing the freezing determination in this way, the ECU 10 holds the current value of the ABV drive current at a steady value. In this way, the ECU 10 performs heating control to continue energization of the air bypass valve 24 and generate heat in the coil 42 of the air bypass valve 24. As a result, the ECU 10 defrosts the air bypass valve 24.

  Here, as shown in FIG. 7, when the engine operating state is not in the supercharging region (when XHi_pm = 0), even if the ABV control voltage signal is turned on and the air bypass valve 24 is opened, the engine load The rate kl (engine torque) does not decrease. However, when the engine operating state is in the supercharging region (when XHi_pm = 1), if the air bypass valve 24 is opened with the ABV control voltage signal turned on, the engine load factor kl (engine torque) decreases. As a result, the supercharging pressure decreases. Therefore, as shown in FIG. 6, when the supercharging region determination flag XHi_pm is set to “1” and the engine operating state is in the supercharging region, the ECU 10 interrupts energization to the air bypass valve 24, and The heating control is interrupted so that the air bypass valve 24 does not open.

  Then, as shown in FIG. 6, after that, when the supercharging region determination flag XHi_pm is set to “0” and the engine operating state is not in the supercharging region, the ECU 10 again sets the current value of the ABV driving current to a steady value. The heating control is performed and the air bypass valve 24 is thawed.

  After that, when the air bypass valve 24 is thawed and opened, the armature 112 (see FIG. 18) moves inside the coil 42 (see FIG. 18), so that a counter electromotive force is generated in the coil 42 due to inductive action. As shown by the broken line in FIG. 6, the ABV drive current decreases from the steady value in the region β, and the current value change amount Δa becomes smaller than the threshold −B. Therefore, the ECU 10 performs the thawing determination that the air bypass valve 24 has been thawed based on such behaviors as the ABV drive current and the current value change amount Δa. Then, the ECU 10 sets the ABV freezing initial condition flag XABV_cold to “0”, sets the ABV control voltage signal from on to off, stops energization of the ABV drive current, and stops the heating control.

  As described above, the ECU 10 performs the freezing determination and the thawing determination based on the behavior such as the ABV driving current and the current value change amount Δa. And ECU10 performs the said heating control until it performs thawing | decompression determination, when freezing determination is performed. However, when the engine operating state is in the supercharging region, energization to the air bypass valve 24 is interrupted, and the heating control is interrupted.

  In the first embodiment as described above, the control device 1 for the internal combustion engine controls the air bypass passage 22 connected to the upstream side and the downstream side of the compressor 44 of the supercharger 16 and the flow rate of the air flowing through the air bypass passage 22. An air bypass valve 24 is provided. Then, the ECU 10 starts energization of the valve opening drive current to the coil 42 of the air bypass valve 24 when the air bypass valve 24 is estimated to be frozen, and the current value of the valve opening drive current decreases. If the air bypass valve 24 is frozen when the steady value is reached without being determined, it is determined that the air bypass valve 24 is frozen. Further, the ECU 10 performs the thawing determination that the air bypass valve 24 has thawed when the current value of the drive current for opening the valve is lower than the steady value after performing the freezing determination. As described above, since the determination of the freezing and thawing of the air bypass valve 24 is performed based on the behavior of the current value of the drive current for opening the valve, the freezing and thawing of the air bypass valve 24 can be determined efficiently and reliably.

  Further, the control device 1 for the internal combustion engine interrupts energization of the drive current for valve opening when it is in a supercharging region where supercharging is performed by the supercharger 16. Thereby, when the engine operating state is in the supercharging region, it is possible to prevent the supercharging pressure from decreasing.

  Further, the air bypass valve 24 is configured so that the threshold value -A, which is a determination value used when performing the freezing determination, and the threshold value -B, which is a determination value used when performing the thawing determination, are set to different current values. It is possible to cope with the difference in behavior of the current value change amount Δa between when the valve is normally opened and when the air bypass valve 24 is defrosted and opened, and the accuracy of the freeze determination and the defrost determination is improved. In the example shown in FIG. 6, the threshold −A is smaller than the threshold −B, but the threshold −A is set to the threshold − depending on the position and configuration of the coil 42 of the air bypass valve 24 and the valve body 104 (see FIG. 18). It is conceivable that the threshold value -A is made equal to B or the threshold value -A is made larger than the threshold value -B.

<Example 2>
Next, Example 2 will be described. In the second embodiment, after the air bypass valve 24 is thawed in the first embodiment, the inside of the air bypass valve 24 is discharged to discharge the condensed water that has entered the air bypass valve 24 under a certain condition. Perform scavenging. In the second embodiment, the ECU 10 periodically executes the ABV control routine shown in FIG. 8 every predetermined time.

  Therefore, when the processing of the routine shown in FIG. 8 is started, the ECU 10 first takes in the starting water temperature thws (step S401) and determines whether or not the deceleration condition is satisfied (step S402).

  If the deceleration condition is not satisfied, the ECU 10 determines whether or not the ABV freezing flag XABV_close is “1” (step S403).

  If the ABV freezing flag XABV_close is “1”, the ECU 10 determines whether or not the ABV scavenging completion flag XABV_o & c is “0” (step S404).

  When the ABV scavenging completion flag XABV_o & c is “0”, the ECU 10 determines whether or not the supercharging region determination flag XHi_pm is “0” (step S405).

  When the supercharging region determination flag XHi_pm is “0”, the ECU 10 determines whether or not the LPL-EGR system 40 is in an off state (step S406).

  When the LPL-EGR system 40 is in an off state, the ECU 10 determines whether or not 1 second has elapsed after the energization of the air bypass valve 24 is executed (step S407). That is, the ECU 10 determines whether 1 second has elapsed since the start of energization of the valve-opening drive current.

  Then, when 1 second has passed after the energization of the air bypass valve 24, the ECU 10 stops energizing the air bypass valve 24 (step S408). After that, the ECU 10 determines whether or not 1 second has elapsed after stopping energization of the air bypass valve 24 (step S409). That is, the ECU 10 stops energization of the valve-opening drive current when 1 second has elapsed from the start of energization of the valve-opening drive current, and thereafter energizes the valve-opening drive current. It is determined whether 1 second has elapsed since the stop.

  Then, when 1 second has passed after the energization of the air bypass valve 24 is stopped, the ECU 10 energizes the air bypass valve 24 (step S410). That is, the ECU 10 executes energization of the valve-opening drive current when one second has elapsed since the energization of the valve-opening drive current was stopped.

  Next, the ECU 10 obtains the number of scavenging times n at the starting water temperature thws (step S411). Here, when obtaining the scavenging frequency n of the air bypass valve 24 based on the starting water temperature thws, the map shown in FIG. 10 is used.

  In step S407, if one second has not elapsed since the energization of the air bypass valve 24 has been performed, the ECU 10 energizes the air bypass valve 24 (step S412), and the process of step S411 described above. Migrate to In step S409, if 1 second has not elapsed since the energization of the air bypass valve 24 is stopped, the ECU 10 proceeds to the process of step S411.

  Next, the ECU 10 determines whether or not the execution and stop of energization of the air bypass valve 24 have been repeated n times (step S413). That is, it is determined whether or not the number of scavenging times has reached n times. When the energization of the air bypass valve 24 and the energization stop are repeated n times, the ECU 10 completes the scavenging of the air bypass valve 24 and sets the ABV scavenging completion flag XABV_o & c to “1”. The setting is made (step S414), and the subsequent processing is temporarily ended. On the other hand, when execution of energization to the air bypass valve 24 and stop of energization are not repeated n times, the ECU 10 once terminates the subsequent processing.

  In step S402, if the deceleration condition is satisfied, the ECU 10 determines whether the deceleration is not in the initial stage (step S415). For example, it is determined whether it is after 1 second from the start of deceleration. If the ECU 10 is not in the initial stage of deceleration, the ECU 10 proceeds to the process of step 403. On the other hand, in the initial stage of deceleration, the ECU 10 energizes the air bypass valve 24 (executes deceleration valve opening control) (step S416), and then terminates the subsequent processing.

  If the ABV freezing flag XABV_close is not “1” in step S403, the ECU 10 executes the control shown in FIG.

  Further, when the ABV scavenging completion flag XABV_o & c is not “0” at step S404, when the supercharging region determination flag XHi_pm is not “0” at step S405, or when the LPL-EGR system 40 is not turned off at step S406. The ECU 10 stops energization of the air bypass valve 24 (interrupts the deceleration valve opening control) (step S417), and temporarily terminates the subsequent processing.

  Here, FIG. 9 will be described. In the process shown in FIG. 9, even when the ABV freezing flag XABV_close is “0”, scavenging inside the air bypass valve 24 is executed under a certain condition when the outside air temperature is low.

  Therefore, when the ABV freezing flag XABV_close is not “1” in step S403 of FIG. 8, the ECU 10 first takes in the outside air temperature tha_out (step S501), and the outside air temperature tha_out is determined as shown in FIG. It is determined whether the temperature is less than 5 ° C. (step S502). If the outside air temperature tha_out is less than 5 ° C., the ECU 10 determines whether or not the ABV scavenging completion flag XABV_o & c is “0” (step S503). When the ABV scavenging completion flag XABV_o & c is “0”, the ECU 10 determines whether or not the supercharging region determination flag XHi_pm is “0” (step S504). When the supercharging region determination flag XHi_pm is “0”, the ECU 10 determines whether or not the LPL-EGR system 40 is in an off state (step S505).

  When the LPL-EGR system 40 is in the off state, the ECU 10 determines whether or not 1 second has elapsed after the energization of the air bypass valve 24 is executed (step S506). When one second has elapsed after energization of the air bypass valve 24, the ECU 10 stops energization of the air bypass valve 24 (step S507), and after the energization of the air bypass valve 24 is stopped, 1 It is determined whether the second has elapsed (step S508). When one second has elapsed after the energization of the air bypass valve 24 is stopped, the ECU 10 energizes the air bypass valve 24 (step S509) and obtains the number of scavenging times n based on the outside air temperature tha_out (step S509). S510). Here, when the number of scavenging times n is obtained based on the outside air temperature tha_out, the map shown in FIG. 11 is used.

  If one second has not elapsed since the energization of the air bypass valve 24 is performed in step S506, the ECU 10 energizes the air bypass valve 24 (step S511), and the process of step S510 described above. Migrate to On the other hand, if 1 second has not elapsed since the energization of the air bypass valve 24 was stopped in step S508, the ECU 10 proceeds to the process of step S510.

  Next, the ECU 10 determines whether the execution and stop of energization of the air bypass valve 24 have been repeated n times (step S512). When execution and stop of energization of the air bypass valve 24 are repeated n times, the ECU 10 completes scavenging inside the air bypass valve 24 and sets the ABV freezing flag XABV_close to “1”. (Step S513), and the subsequent processing is temporarily terminated. On the other hand, when execution and stop of energization to the air bypass valve 24 are not repeated n times, the ECU 10 once terminates the subsequent processing.

  Further, when the outside air temperature tha_out is not less than 5 ° C. in step S502 (the outside air temperature tha_out is 5 ° C. or more), or when the ABV scavenging completion flag XABV_o & c is not “0” in step S503, or in step S504 If the flag XHi_pm is not “0”, or if the LPL-EGR system 40 is not turned off in step S505, the ECU 10 stops energizing the air bypass valve 24 (interrupts the deceleration valve opening control). (Step S514), the subsequent processing is temporarily ended.

  Here, FIG. 12 shows a time chart of the ABV freezing flag XABV_close, the ABV scavenging completion flag XABV_o & c, the supercharging region determination flag XHi_pm, and the ABV control voltage signal in the second embodiment.

  As shown in FIG. 12, the ECU 10 sets the ABV freezing flag XABV_close to “1”, sets the ABV scavenging completion flag XABV_o & c to “0”, and sets the supercharging region determination flag XHi_pm to “0”. When not in the supply range, scavenging control of the air bypass valve 24 is started. Thereafter, when the number of scavenging times of the air bypass valve 24 reaches n times (10 times as an example in the example shown in FIG. 12), the ECU 10 sets the ABV freezing flag XABV_close to “0” and sets the ABV scavenging completion flag XABV_o & c. Is set to “1”, and scavenging inside the air bypass valve 24 is terminated. As shown in FIG. 12, the ECU 10 performs scavenging inside the air bypass valve 24 under the condition that the supercharging region determination flag XHi_pm is “0” and not in the supercharging region.

  As described above, in the second embodiment, the ECU 10 performs the air-conditioning operation after the air bypass valve 24 is defrosted and the thawing determination is performed, and when the engine operating state is not in the supercharged region (is in the non-supercharged region). By repeatedly opening and closing the bypass valve 24, scavenging of the air bypass valve 24 is performed. Thereby, the condensed water that has entered the air bypass valve 24 can be discharged, and thereafter the air bypass valve 24 can be prevented from freezing. At this time, it is desirable to increase the number of scavenging times n of the air bypass valve 24 as the time required for the air bypass valve 24 to defrost is longer. However, when the engine operating state is in the supercharging region, scavenging of the air bypass valve 24 is not performed.

  Further, the ECU 10 scavenges the air bypass valve 24 when the engine operating state is not in the supercharging region and the LPL-EGR system 40 is in an off state. Thereby, it is possible to prevent the condensed water contained in the EGR gas from the LPL-EGR system 40 from entering the air bypass valve 24.

  Further, the ECU 10 may execute an ABV control routine when the ignition switch shown in FIG. 13 is turned off (IG_OFF). As shown in FIG. 13, the ECU 10 first determines whether or not the ignition switch has been turned off from on (IG_ON => OFF) (step S601). When the ignition switch is turned off from on, the ECU 10 energizes the air bypass valve 24 (step S602), and after opening the air bypass valve 24, the ignition switch is turned on from off. The engine 26 is stopped 0.5 seconds later (IG_ON => OFF_0.5 seconds later) (step S603), and the subsequent processing is temporarily ended. On the other hand, if the ignition switch is not turned off from on in step S601, the subsequent processing is temporarily terminated. In this way, scavenging of the air bypass valve 24 may be performed when the ignition switch is turned off.

  According to the second embodiment, the ECU 10 performs control so as to scavenge the inside of the air bypass valve 24 when it is in a non-supercharging region where the supercharger 16 does not perform supercharging after performing the thawing determination. To do. Thereby, the condensed water remaining inside the air bypass valve 24 can be discharged. Therefore, it is possible to prevent the air bypass valve 24 from freezing.

  Further, the ECU 10 controls the air bypass valve 24 according to the thawing control time from when energization of the drive current for opening the valve is started until the thawing determination is performed, the starting water temperature thws, or the outside air temperature tha_out. The number of scavenging times n for scavenging the inside is defined. Thereby, according to the freezing condition of the air bypass valve 24, the condensed water remaining inside the air bypass valve 24 after thawing can be effectively discharged.

  The control device 1 for the internal combustion engine includes an LPL-EGR system 40 that recirculates EGR gas from the downstream side of the turbine 46 of the supercharger 16 to the upstream side of the compressor 44. The ECU 10 performs control so that the inside of the air bypass valve 24 is scavenged when the EGR gas is not recirculated by the LPL-EGR system 40. Thereby, when scavenging the inside of the air bypass valve 24, it is possible to prevent the condensed water contained in the EGR gas recirculated from the LPL-EGR system 40 from entering the inside of the air bypass valve 24. Therefore, the air bypass valve 24 can be prevented from freezing due to the condensed water contained in the EGR gas.

  Further, the ECU 10 performs control so that the inside of the air bypass valve 24 is scavenged when the ignition switch is turned off. As a result, the condensed water that may exist inside the air bypass valve 24 when the engine 26 is stopped is discharged, so that it is possible to prevent the air bypass valve 24 from being frozen when the engine 26 is started next time.

  The timing (timing) for scavenging the inside of the air bypass valve 24 may be performed, for example, every time when a certain period of time elapses and various conditions are met while the vehicle is traveling.

<Example 3>
Next, Example 3 will be described. In the third embodiment, the air bypass valve 24 is continuously energized until the water temperature becomes equal to or higher than a predetermined temperature after the engine 26 is started, and the air bypass valve 24 is defrosted. In the third embodiment, the ECU 10 periodically executes the ABV control routine shown in FIG. 14 every predetermined time.

  Therefore, when the processing of the routine shown in FIG. 14 is started, the ECU 10 first takes in the starting water temperature thws (step S701) and determines whether or not the deceleration condition is satisfied (step S702).

  When the deceleration condition is not satisfied, the ECU 10 determines whether or not the starting water temperature thws is less than 0 ° C. (step S703).

  When the starting water temperature thws is lower than 0 ° C., the ECU 10 determines whether or not the ABV freezing initial condition flag XABV_cold is “1” (step S704).

  When the ABV freezing initial condition flag XABV_cold is “1”, the ECU 10 takes in the water temperature thw (step S705) and determines whether or not the current water temperature thw of the engine 26 is less than 30 ° C. ( Step S706).

  If the water temperature thw is less than 30 ° C., the ECU 10 determines whether or not the supercharging region determination flag XHi_pm is “0” (step S707).

  If the supercharging region determination flag XHi_pm is “0”, the air bypass valve 24 is energized to perform heating control (step S708), and the subsequent processing is temporarily ended.

  When the deceleration condition is satisfied in step S702, the ECU 10 energizes the air bypass valve 24 (executes deceleration valve opening control) (step S709), and temporarily terminates the subsequent processing. If the starting water temperature thws is not less than 0 ° C. (0 ° C. or more) in step S703, the ECU 10 sets the ABV freezing initial condition flag XABV_cold to “0” (step S710), and the air bypass valve The energization to 24 is stopped (deceleration valve opening control is interrupted) (step S711), and the subsequent processing is temporarily ended. If the water temperature thw is 30 ° C. or higher in step S706, the ECU 10 sets the ABV freezing initial condition flag XABV_cold to “0” (step S712), and the process proceeds to step S711. If the supercharging region determination flag XHi_pm is not “0” in step S707, the ECU 10 proceeds to step S711.

  As described above, in the third embodiment, after the engine 26 is started, energization of the air bypass valve 24 is continued until the water temperature becomes equal to or higher than the predetermined temperature. Thereby, the air bypass valve 24 is thawed. However, when the air bypass valve 24 is in the supercharging region, power supply to the air bypass valve 24 is temporarily stopped to avoid a decrease in supercharging pressure due to the opening of the air bypass valve 24 in the supercharging region.

<Example 4>
Next, Example 4 will be described. In the fourth embodiment, the predetermined temperature in the third embodiment is set according to the starting water temperature thws. In the fourth embodiment, the ECU 10 periodically executes the ABV control routine shown in FIG. 15 every predetermined time.

  In the fourth embodiment, as a difference from the third embodiment, the ECU 10 obtains the heating determination water temperature thwav corresponding to the starting water temperature thws (step S806), and determines whether the water temperature thw is lower than the heating determination water temperature thwav. (Step S807). Here, when obtaining the heating determination water temperature thwavv corresponding to the starting water temperature thws, the map shown in FIG. 16 is used. Other steps are the same as those in the third embodiment.

  Here, in Example 4, FIG. 17 shows a time chart of the ABV freezing initial condition flag XABV_cold, the ABV control voltage signal, and the water temperature (engine water temperature). As shown by the solid line in FIG. 17, when the starting water temperature thws is lower than 0 ° C., it is estimated that the air bypass valve 24 is frozen, and when the ignition switch is turned on (IG_ON), the air bypass valve 24 is turned on. Execute energization. After that, when the water temperature becomes higher than the heating determination water temperature thwavv, it is determined that the air bypass valve 24 has been thawed, and energization to the air bypass valve 24 is stopped. On the other hand, as shown by a broken line in FIG. 17, when the starting water temperature thws is 0 ° C. or higher, it is estimated that the air bypass valve 24 is not frozen, and the air bypass valve 24 is turned on when the ignition switch is turned on (IG_ON). Do not energize the.

  As described above, in the fourth embodiment, as in the third embodiment, the air bypass valve 24 is continuously energized until the water temperature becomes equal to or higher than the predetermined temperature after the engine 26 is started, but the lower the starting water temperature thws, that is, the suction. The predetermined temperature is set higher as the temperature is lower. Thereby, the air bypass valve 24 is defrosted reliably. In addition, the integrated intake air amount (integrated Ga) and the integrated time after the water temperature reaches a predetermined temperature may be increased as the starting water temperature thws is lower.

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 1 Control apparatus 10 of internal combustion engine ECU
14 intake passage 16 supercharger 22 air bypass passage 24 air bypass valve 26 engine 28 exhaust passage 40 LPL-EGR system 42 coil 44 compressor 46 turbine 48 EGR passage 50 EGR cooler 52 EGR valve 56 water temperature sensor thws start time water temperature XABV_cold ABV freezing Initial condition flag XHi_pm Supercharging region determination flag Δa Current value change amount XABV_close ABV freezing flag-A threshold-B threshold XABV_o & c ABV scavenging completion flag tha_out outside air temperature thw water temperature thwavv heating determination water temperature

Claims (7)

A bypass passage connected to the upstream side and the downstream side of the compressor of the turbocharger;
A solenoid valve for controlling the flow rate of the gas flowing through the bypass passage;
When it is estimated that the solenoid valve is frozen, when the drive current of the solenoid valve starts energization for opening the valve, the current value of the drive current reaches a steady value without decreasing. Freeze-thaw determination that performs freeze determination that the solenoid valve is frozen, and performs the freeze-thaw determination that the solenoid valve has thawed when the current value of the drive current drops below a steady value after performing the freeze determination Means,
A scavenging control means for controlling to scavenge the inside of the solenoid valve when the freezing and thawing judging means is in a non-supercharging region where the supercharging is not performed after the thawing judgment. When,
Having
A control device for an internal combustion engine. The control apparatus for an internal combustion engine according to claim 1,
Interrupting energization of the drive current when in a supercharging region where supercharging is performed by the supercharger;
A control device for an internal combustion engine. The control device for an internal combustion engine according to claim 1 or 2 ,
The scavenging control means scavenges the inside of the solenoid valve in accordance with a thawing control time from when energization of the drive current is started until the thawing determination is performed, or a water temperature at start-up or an outside air temperature. Prescribing the number of times,
A control device for an internal combustion engine. The control device for an internal combustion engine according to any one of claims 1 to 3 ,
An EGR system that recirculates EGR gas from a downstream side of the turbocharger turbine to an upstream side of the compressor;
The scavenging control means controls the scavenging of the solenoid valve when the EGR gas is not recirculated by the EGR system;
A control device for an internal combustion engine. The control device for an internal combustion engine according to any one of claims 1 to 4 ,
The scavenging control means controls the scavenging of the interior of the solenoid valve when the ignition switch is turned off;
A control device for an internal combustion engine. When freezing of the solenoid valve that controls the flow rate of the gas flowing through the bypass passages connected to the upstream side and the downstream side of the compressor of the supercharger is estimated, energization of the drive current for opening the valve to the solenoid valve drive unit When the current value of the drive current reaches a steady value without decreasing after the start of the operation, it is determined that the solenoid valve is frozen, and the current value of the drive current after the freeze determination is performed. when there have line decompression determination that the solenoid valve is thawed when lower than steady-state value, does not perform the supercharging by the supercharger even after performing the decompression judgment in the non-supercharging zone Controlling the interior of the solenoid valve to scavenge,
A control method for an internal combustion engine. A bypass passage connected to the upstream side and the downstream side of the compressor of the turbocharger;
A solenoid valve for controlling the flow rate of the gas flowing through the bypass passage;
A scavenging control means for controlling to scavenge the inside of the solenoid valve by repeatedly opening and closing the solenoid valve when in a non-supercharge range where supercharging is not performed by the supercharger;
Having
A control device for an internal combustion engine.

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