JP6505073B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to control of an internal combustion engine having a supercharger for supercharging intake air and a waste gate valve provided in a bypass passage bypassing a turbine of the supercharger for adjusting supercharging pressure by the supercharger. It relates to the device.

  Conventionally, as a control device for this type of internal combustion engine, for example, the one described in Patent Document 1 is known. The internal combustion engine is mounted on a vehicle, and the waste gate valve is composed of a valve body for opening and closing the bypass passage and an electric actuator for driving the valve body. In this control device, the fully closed position learning of the waste gate valve is performed during idle stop which automatically stops the internal combustion engine when a predetermined stop condition is satisfied. Specifically, the position at which the valve body actually abuts the inner wall of the bypass passage from the change in the current value of the actuator when the actuator is operated and the valve body is repeatedly brought into contact with the inner wall of the bypass a plurality of times. Is detected, and the closing position of the waste gate valve is learned based on the detection result.

Unexamined-Japanese-Patent No. 2015-45297

  As a conventional waste gate valve different from the configuration described above, there is a type in which an electric actuator and a valve body are connected by a link mechanism composed of a plurality of link members. This configuration is to thermally protect electronic components and the like that constitute the actuator from high temperature exhaust, and the actuator is disposed at a position away from the bypass passage into which the exhaust flows. In addition, in this type of waste gate valve, in order to prevent the link mechanism from being stretched by thermal expansion at high temperatures, there is usually a play for absorbing thermal expansion at the connection between the plurality of link members of the link mechanism. It is set in advance.

  When opening such a waste gate valve from the fully closed state, if the actuator is operated in the valve opening direction, at first, the movement of the actuator was spent to fill the play of the link mechanism and the play was lost. Since the valve body is driven for the first time at a time, it is inevitable that the valve opening operation is delayed, and a good valve opening response can not be obtained. As a result, the increased boost pressure can not be reduced quickly, and sufficient acceleration performance can not be obtained particularly on the low speed side. In addition, even if the above-described conventional learning device performs learning of the fully closed position using this waste gate valve as a target, errors due to various factors such as temperature dependent errors of the link mechanism and aging errors due to wear are reflected. Since the fully closed position is only learned and the amount of play of the link mechanism is not grasped, it can not be used to improve the valve open response.

  The present invention has been made to solve such a problem, and learns the amount of play of a link mechanism connected between an electric actuator and a waste gate valve, and also responds to opening of the waste gate valve. It is an object of the present invention to provide a control device of an internal combustion engine which can improve the

In order to achieve this object, the invention according to claim 1 of the present application is a supercharger for supercharging intake air (the turbocharger 12 in the embodiment (hereinafter the same in this section)) and a turbine 121 of the supercharger. Is connected to a drive (motor 31, rod 32) including an electric actuator (motor 31) via a link mechanism 34, and adjusts the supercharging pressure Pbst by the turbocharger. Control device for an internal combustion engine having a waste gate valve 14 for detecting an opening degree (detection opening degree WGA) of the waste gate valve 14 via an operating position of a drive device (rod 32) (Valve opening sensor 23), supercharging pressure detection means (supercharging pressure sensor 27) for detecting supercharging pressure Pbst, and an actuator Control means (ECU 20, FIG. 5) for controlling the opening degree (valve opening degree WGO) of the gate valve 14 and in a state where the actuator is driven in the valve opening direction from the fully closed state of the waste gate valve 14 Learning means for learning the detected opening degree WGA detected by the opening degree detecting means when the supercharging pressure Pbst starts to fall as the play amount equivalent opening degree WGP corresponding to the play amount of the link mechanism 34 (ECU 20, FIG. Steps 5 and 6), and the control means causes the detection opening degree WGA to be equivalent to the play amount in order to return the waste gate valve 14 to the fully closed state after learning of the play amount equivalent opening degree WGP is completed. It is characterized in that the actuator is controlled (steps 7 , 10 to 12 , 15, 16 in FIG. 5) so as to become a predetermined fully closed target opening degree WGRTN on the valve closing side than the opening degree WGP .

  The waste gate valve of this internal combustion engine is driven via a link mechanism by a drive including an electrically powered actuator, and the operation of these is controlled by the control means. In addition, the opening degree of the waste gate valve is detected via the operating position of the drive device, and the supercharging pressure by the supercharger is detected.

  As described above, in the above-described waste gate valve configuration, play (hereinafter referred to as "link play") is usually present in the link mechanism. According to the present invention, learning of the link play amount is performed as follows. First, the actuator is driven in the valve opening direction from the fully closed state of the waste gate valve. Then, the detected opening degree of the waste gate valve detected when the supercharging pressure detected in the driving state starts to fall is learned as an opening degree equivalent opening degree corresponding to the link play amount.

  When link play is present, when the drive including the actuator is driven in the valve opening direction from the fully closed state of the waste gate valve, the detection opening degree of the waste gate detected through the operating position of the drive is While the waste gate valve changes depending on the amount of actuation of the actuator, the waste gate valve is not driven until the link play disappears, and remains fully closed. After that, when the link play disappears, the waste gate valve starts to open, and the exhaust pressure escapes from the bypass passage, thereby reducing the supercharging pressure. Therefore, according to the above configuration, it is possible to appropriately learn the opening degree of the waste gate valve detected when the supercharging pressure starts to decrease, as the opening degree equivalent opening degree corresponding to the link play amount.

  In addition, the play amount equivalent opening degree corresponds to an opening degree at which the link play is eliminated and the waste gate valve actually starts to open. Therefore, the opening responsiveness of the waste gate valve can be improved by controlling the opening operation of the waste gate valve based on the learned amount-of-play equivalent opening degree.

Further, since learning of the play amount equivalent opening degree is performed as described above, at the end of learning, the waste gate valve is slightly opened, and the exhaust gas flowing into the bypass passage leaks from the waste gate valve. . According to this configuration, after the learning of the play amount equivalent opening degree is completed, the actuator is controlled such that the detected opening degree becomes a predetermined fully closed target opening degree on the valve closing side than the play amount equivalent opening degree. Thus, the waste gate valve is returned to the fully closed state. Thereby, the supercharging operation until the valve opening operation of the waste gate valve is performed can be stably performed without exhaust leakage from the bypass passage.

The invention according to claim 2 is the control device for an internal combustion engine according to claim 1, further comprising a storage means (ECU 20) for storing the learned amount-of-play equivalent opening degree WGP, and the control means is a waste gate valve 14 To maintain the waste gate valve 14 in the fully closed state during the supercharging operation with the fully closed state, when the predetermined fully closed position on the valve closing side than the play amount equivalent opening degree WGP in which the detected opening degree WGA is stored The actuator is controlled to achieve the target opening degree WGRTN.

  According to this configuration, the learned amount-of-play equivalent opening degree is stored in the storage means, and during the supercharging operation in which the waste gate valve is fully closed thereafter, the detected amount-of-opening is stored The waste gate valve is maintained in the fully closed state by controlling the actuator so that the predetermined fully closed target opening on the valve closing side is achieved. As a result, for example, the play already learned during the supercharging operation even when learning of the play amount equivalent opening degree is not performed for a long time or is not completed due to conditions of supercharging pressure, conditions of learning frequency, etc. The waste gate valve can be kept fully closed based on the amount equivalent opening degree, so the supercharging operation until the waste gate valve opening operation is performed is stabilized without exhaust leakage from the bypass passage. Can be done.

The invention according to claim 3 is the control apparatus for an internal combustion engine according to claim 1 or 2 , wherein the predetermined fully closed target opening degree WGRTN is set on the valve closing side near the play amount equivalent opening degree WGP. It is characterized by

  According to this configuration, by setting the predetermined fully-closed target opening degree on the valve closing side near the play amount equivalent opening degree, the waste gate valve has little or no link play in the valve opening direction. It will be closed. Therefore, the valve opening operation of the waste gate valve can be started from such a fully closed state, whereby good valve opening response can be obtained.

FIG. 1 is a view schematically showing a configuration of a drive system of a vehicle including an internal combustion engine to which the present invention is applied. FIG. 1 schematically shows a configuration of an internal combustion engine. It is a figure which shows a waste gate valve and its drive mechanism typically. It is a block diagram showing composition of a control device of an internal-combustion engine. It is a flowchart which shows the play learning control processing which controls the valve opening operation while learning the link play of a waste gate valve. It is a timing chart which shows the operation example obtained by the process of FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the vehicle V is a hybrid vehicle having an internal combustion engine (hereinafter referred to as "engine") 1 as a drive source, and a motor (hereinafter referred to as "motor") 61 functioning as a drive source and a generator. , And / or a transmission 52 that changes the driving force of the motor 61.

  The motor 61 is connected to a power drive unit (hereinafter referred to as “PDU”) 62, and the PDU 62 is connected to a high voltage battery 63. When driving the motor 61 with a positive drive torque, that is, when driving the motor 61 with the power output from the high voltage battery 63, the power output from the high voltage battery 63 is supplied to the motor 61 via the PDU 62. Further, when the motor 61 is driven with a negative drive torque, that is, when the motor 61 is regenerated, the electric power generated by the motor 61 is supplied to the high voltage battery 63 via the PDU 62 and charged.

  The PDU 62 is connected to an electronic control unit (hereinafter referred to as "ECU") 20, and controls the operation of the motor 61 under the control of the ECU 20, and controls charging and discharging of the high voltage battery 63.

  The transmission 52 is a so-called dual clutch type, and is connected to the crankshaft 51 of the engine 1 via an odd gear clutch and an even gear clutch (both not shown), and transmitted from the engine 1 The power is shifted by the odd gear stage or the even gear stage. The shifted driving force is transmitted to the drive wheel 56 via the output shaft 53 of the transmission 52, the differential gear mechanism 54, and the drive shaft 55, whereby the vehicle V is driven.

  According to the above configuration, the vehicle V has an engine drive mode driven only by the engine 1 as a drive mode, a motor drive mode driven only by the motor 61 with the two clutches of the transmission 52 disconnected, and an engine And a hybrid drive mode driven by both the motor 1 and the motor 61.

  As shown in FIG. 2, the engine 1 is a direct injection engine that has, for example, four cylinders 6 in series, and injects fuel directly into a combustion chamber (not shown) of the cylinders 6. Each cylinder 6 is provided with a fuel injection valve 7, an ignition plug 8, an intake valve and an exhaust valve (all not shown).

  The engine 1 also includes an intake passage 2, an exhaust passage 10, and a turbocharger 12 as a supercharger. The intake passage 2 is connected to a surge tank 4, and the surge tank 4 is connected to the combustion chamber of each cylinder 6 via an intake manifold 5. The intake passage 2 is provided with a compressor 123 (described later) of the turbocharger 12, an intercooler 3 for cooling air pressurized by the turbocharger 12, and a throttle valve 13 in this order from the upstream side. The throttle valve 13 is driven by a throttle (TH) actuator 13a.

  An intake pressure sensor 21 for detecting an intake pressure PB is provided in the surge tank 4, and an intake air amount sensor 22 for detecting an intake air amount GAIR is provided on the upstream side of the compressor 123 of the intake passage 2. .

  The turbocharger 12 includes a turbine 121 provided in the exhaust passage 10 and rotationally driven by the operation energy of the exhaust, and a compressor 123 provided in the intake passage 2 and connected to the turbine 121 via a shaft 122. The compressor 123 pressurizes air (intake air) sucked into the engine 1 to perform supercharging. A bypass passage 16 for bypassing the compressor 123 is connected to the intake passage 2, and an air bypass valve (hereinafter referred to as “AB valve”) for adjusting the flow rate of air passing through the bypass passage 16 is connected to the bypass passage 16. ) 17 is provided. A charge pressure sensor 27 for detecting the charge pressure Pbst is provided immediately downstream of the compressor 123 and the AB valve 17 in the intake passage 2.

  The exhaust passage 10 is connected to the combustion chamber of each cylinder 6 via an exhaust manifold 9. A bypass passage 11 for bypassing the turbine 121 is connected to the exhaust passage 10, and a charge pressure of the exhaust gas passing through the bypass passage 11 is adjusted at a downstream connection portion of the bypass passage 11. A waste gate valve (hereinafter referred to as "WG valve") 14 is provided to adjust the pressure.

  As shown in FIG. 3, the drive mechanism for driving the WG valve 14 is connected to the drive device 30 having the motor 31 and the rod 32 as an actuator, and the rod 32 via the heat shield member 33. A link mechanism 34 connected to the valve body 15 is provided. The motor 31 is, for example, a DC motor, and under the control of the ECU 20, the motor 31 is switched between normal rotation and reverse rotation according to the direction of energization, and the duty ratio of drive pulse for energization (hereinafter referred to as “energization duty ratio The torque of the motor 31 is controlled in accordance with the I duty.

  Although not shown, a female screw is formed on the rotor of the motor 31, and a male screw is formed on the rod 32 to be screwed to the female screw. With this configuration, the rotation of the motor 31 is converted to the linear movement of the rod 32, and the rod 32 moves to the right or left in FIG. 3 according to the rotation direction of the motor 31.

  The link mechanism 34 is pivotable to the connecting member 34a coupled to the rod 32 via the heat shield member 33, the first link member 34b pivotably coupled to the coupling member 34a, and the first link member 34b. The second link member 34c is rotatably connected to and supported by the rotation shaft 35. The second link member 34c is connected to the second link member 34c. A holding member 36 is integrally provided on the second link member 34c, and the valve body 15 of the WG valve 14 is integrally held on the holding member 36 (see FIG. 3B).

  Further, in order to prevent the link mechanism 34 from being stretched by thermal expansion at high temperatures, each connecting portion of the link mechanism 34, specifically, a connecting portion of the connecting member 34a and the first link member 34b, a first link member 34b A predetermined amount of play is preset in each of the connecting portion of the second link member 34c and the connecting portion of the second link member 34c and the rotary shaft 35.

  FIG. 3A shows a closed state of the WG valve 14, that is, a state in which the WG valve 14 closes the bypass passage 11. When a current in a predetermined direction is supplied to the motor 31 from this valve closed state, the motor 31 is rotationally driven in a predetermined direction accordingly, and the rod 32 engaged with the rotor is in the direction of arrow B in FIG. Moving. Accordingly, the WG valve 14 is opened by rotating the second link member 34c of the link mechanism 34 and the holding member 36 and the valve body 15 integral therewith in the direction of the arrow C about the rotation shaft 35.

  When a current in the opposite direction to the above is supplied to the motor 31 from this open state, the motor 31 is rotationally driven in the opposite direction, the rod 32 moves in the opposite direction to the arrow B, and the link mechanism 34 The WG valve 14 is returned to the closed state by the second link member 34c, the holding member 36 and the valve body 15 rotating in the opposite direction to the arrow C, operating in the opposite direction to the above. Hereinafter, as described above, the energization duty ratio I duty when driving the WG valve 14 to the valve opening side is defined as “positive”, and the energization duty ratio I duty when driving the WG valve 14 to the valve closing side is defined as “negative”. Do.

  Therefore, when the energization duty ratio I duty is negative, the WG valve 14 is driven toward the fully closed position, and the valve body 15 is moved to the valve seat (not shown) at the time of valve closing as the absolute value is larger. The pressing force is greater. Further, since the rotor of the motor 31 is screwed to the rod 32, the energization duty ratio I duty becomes 0, and when the rotation of the motor 31 is stopped, the WG valve 14 is maintained at the opening degree at the time of stopping.

  Further, a valve opening degree sensor 23 is provided at an end of the rod 32 opposite to the valve body 15. The valve opening degree sensor 23 detects the position of the WG valve 14 (hereinafter referred to as “detection opening degree”) WGA by detecting the position of the rod 32 in the axial direction (arrow B direction). The drive mechanism (not shown) of the AB valve 17 is similarly configured, and this drive mechanism is a motor for opening and closing the AB valve 17 or a valve opening degree for detecting the opening degree of the AB valve 17 It has a sensor.

  In addition, since the detection opening degree WGA of the valve opening degree sensor 23 is indirectly acquired via the position of the rod 32 as described above, the constituent members of the link mechanism 34 existing between the valve body 15 and the rod 32 Include age-related errors due to wear and so forth, and temperature-dependent errors depending on temperature. In order to compensate for such an error, totally closed position learning of the WG valve 14 is appropriately performed.

  Specifically, immediately after the ignition switch is turned on or during operation of the engine 1, the detected opening degree WGA when the WG valve 14 is located or reached at the fully closed position is learned as a fully closed opening learning value WGFC. ·Remember. Then, a value obtained by subtracting the fully closed opening degree learning value WGFC from the detected opening degree WGA obtained thereafter is calculated as the opening degree of the WG valve 14 at that time (hereinafter referred to as “valve opening degree”) WGO. In the opening degree control of the WG valve 14 described later, the valve opening degree WGO learned and corrected as described above is used.

  FIG. 4 shows a configuration of a control device of the engine 1. In addition to the intake pressure sensor 21, the intake air amount sensor 22, the valve opening degree sensor 23 and the boost pressure sensor 27 described above, the ECU 20 is a rotation that detects the number of revolutions NE of the engine 1 (hereinafter referred to as “engine revolution number”) The accelerator opening sensor 25 detects the number sensor 24, the operation amount of the accelerator pedal of the vehicle V (hereinafter referred to as "accelerator opening") AP, and the temperature TW of the coolant of the engine 1 (hereinafter referred to as "engine water temperature") A water temperature sensor 26 or the like to be connected is connected, and their detection signals are input. The fuel injection valve 7, the spark plug 8, the TH actuator 13a, the WG valve 14 (motor 31), and the AB valve 17 (motor) are connected to the output side of the ECU 20.

  The ECU 20 is constituted by a microcomputer including a CPU, a RAM, a ROM, an input interface (all not shown) and the like, and the drive mode of the vehicle V according to the detection signals of the various sensors 21 to 27 described above. And control the engine 1 and the motor 61 in accordance with the determined drive mode.

  Further, the ECU 20 controls fuel injection by the fuel injection valve 7, ignition control by the spark plug 8, and throttle control according to the operating state of the engine 1 (mainly the engine speed NE and the required torque TRQD) as control of the engine 1 described above. The intake air amount control by the valve 13 and the supercharging pressure control by the WG valve 14 are performed. The required torque TRQD is calculated to increase as the accelerator opening AP increases, mainly according to the accelerator opening AP.

  In this embodiment, in particular, the ECU 20 learns the amount of play (the amount of link play) of the link mechanism 34 of the WG valve 14 and at the same time controls the valve opening operation of the WG valve 14 based on the learned amount of link play. Execute the process In the embodiment, the ECU 20 corresponds to control means, learning means and storage means.

  FIG. 5 is a flowchart of this play learning control process. The present process is repeatedly performed at predetermined time intervals. In this process, first, in step 1 (shown as “S1”, the same applies to the following), it is determined whether or not the learning control flag F_LRN / CNT is “1”. The learning control flag F_LRN / CNT is, for example, controlled to the fully closed state of the WG valve 14 during operation of the engine 1 when the condition for executing the idle learning control is satisfied, and the detected supercharging pressure Pbst is Set to '1' when in a relatively stable low state. When the answer to this step 1 is NO and the execution condition is not satisfied, the present process is ended as it is.

  If the answer to step 1 is yes, the process proceeds to step 2 to execute play learning control, and it is determined whether a play learning completion flag F_LRNPDN is "1". If the answer is NO and play learning (learning the amount of link play) has not been completed, the energization duty ratio I duty of the motor 31 is set to a predetermined value IdLRNP for play learning (step 3). The energization in this case is for gradually driving the motor 31 and the rod 32 in the valve opening direction for learning the play. Therefore, the predetermined value IdLRNP is set to a relatively small positive value (for example, + 10%).

  Next, the difference between the previous value Pbstz of the detected supercharging pressure and the current value Pbst (= Pbstz-Pbst) is calculated as the supercharging pressure reduction amount ΔPbst (step 4), and the calculated supercharging pressure reduction amount It is determined whether .DELTA.Pbst is equal to or greater than a predetermined threshold value .DELTA.PREF close to the value 0 (step 5). When the answer is NO, this processing ends.

  On the other hand, if the answer in step 5 is YES and ΔPbst Δ ΔPREF is satisfied, the link play is eliminated, and it is assumed that the supercharging pressure Pbst starts to decrease with the fact that the WG valve 14 is actually opened. The detected opening degree WGA of the valve opening degree sensor 23 is calculated as an opening amount equivalent opening degree WGP corresponding to the link play amount (step 6).

  Next, a fully closed target opening degree WGRTN is calculated by subtracting a predetermined opening amount ΔWGRTN from the play amount equivalent opening degree WGP (step 7). As will be described later, this opening degree amount ΔWGRTN corresponds to the minimum value among the opening degree amounts capable of returning the WG valve 14 opened as described above to the fully closed state, that is, the WG valve 14 has a play This corresponds to an opening amount which is in a fully closed state (hereinafter referred to as a "play-free fully closed state") which is hardly present, and is preset based on experimental results and the like. Next, to indicate that the play learning has been completed, the play learning completion flag F_LRNPDN is set to “1” (step 8), and this processing is terminated.

  Thus, after the idle learning is completed, the answer in step 2 is YES. In this case, the process proceeds to step 9, and it is determined whether the return control completion flag F_WGRTNDN is "1". When the answer is NO and the return control for returning the WG valve 14 to the fully closed state is not completed, the energization duty ratio Iduty is a relatively small negative value and a predetermined value IdRTN for return control (for example, -10%) ) (Step 10). As a result, the WG valve 14 is gradually returned from the open state to the valve closing side.

  Next, it is determined whether or not the detected opening degree WGA has become equal to or less than the fully closed target opening degree WGRTN set in the step 7 (step 11), and when the answer is NO, this processing ends. On the other hand, when the answer in step 11 is YES and the detected opening WGA reaches the fully closed target opening WGRTN, the WG valve 14 is fully closed without play, and the return control is completed, and the return control completion flag F_WGRTNDN is set to "1" (step 12), and the process ends.

  After completion of the return control, the answer to step 9 is YES. In this case, the process proceeds to step 13 to determine whether the valve open instruction flag F_CMDOPN is "1". When the answer is NO and the valve opening of the WG valve 14 is not instructed, the energization duty ratio I duty is set to 0 (step 14), and the present process is ended. As a result, the WG valve 14 is maintained in the fully closed state without play.

  On the other hand, when the answer in step 13 is YES and the valve opening of the WG valve 14 is instructed, the valve opening duty ratio IdOPN is calculated according to the target opening degree WGCMD at that time (step 15). The ratio I duty is set to the valve opening duty ratio IdOPN (step 16), and the present process is terminated. Thereby, the valve opening operation of the WG valve 14 is started from the playless fully closed state.

  Next, an operation example obtained by the above-described play learning process and the like will be described with reference to FIG. FIGS. 6A to 6C show changes in the supercharging pressure Pbst, the energization duty ratio Iduty of the motor 31, and the detected opening degree WGA of the valve opening degree sensor 23, respectively.

  Until time t1, the supercharging operation is performed in which the WG valve 14 is fully closed. At time t1, the energization duty ratio Iduty is set to a positive value to reduce the supercharging pressure. Valve opening operation is started. At time t2, when the opening degree of the WG valve 14 (valve opening degree WGO) reaches the target opening degree WGCMD, the energization duty ratio Iduty is set to 0, whereby the opening degree of the WG valve 14 is maintained constant. .

  Thereafter, as the target opening degree WGCMD decreases according to the operating state of the engine 1, from time t3, the energization duty ratio Iduty is controlled to a negative value side, and accordingly, the WG valve 14 is controlled to a valve closing side. At time t4, the fully closed state is reached. At this timing, the amount of link play is approximately zero. Thereafter, as the motor 31 is continuously driven in the valve closing direction, the amount of link play increases and reaches the maximum value at time t5. For example, at this timing, the fully closed position learning of the WG valve 14 is performed.

  After that, the energization duty ratio I duty is set to 0, and the WG valve 14 is maintained in the fully closed state. When the supercharging pressure Pbst becomes substantially constant at time t6, it is determined that the execution condition of the idle learning control is satisfied, and the energization duty ratio Iduty is set to a predetermined value IdLRNP (positive value) for idle learning (step 3 in FIG. 5). ). As a result, the motor 31 and the rod 32 are driven in the valve opening direction, and the detection opening degree WGA changes to the valve opening side, whereas the WG valve 14 is not driven until the link play amount becomes zero, and the valve is fully closed. It is maintained in the state.

  At time t7, when the link play amount becomes 0 and the supercharging pressure Pbst starts to decrease as the WG valve 14 actually opens, the answer in step 5 becomes YES, and the detected opening at that time WGA is calculated as the play amount equivalent opening degree WGP, and a value obtained by subtracting the opening degree amount ΔWGRTN from the play amount equivalent opening degree WGP is calculated as the fully closed target opening degree WGRTN (steps 6, 7).

  At time t8 immediately after that, the energization duty ratio Iduty is set to a predetermined value IdRTN (negative value) for return control, and return control is started (step 10). When the detected opening degree WGA reaches the fully closed target opening degree WGRTN at time t9, the answer in step 11 becomes YES, and the return control is ended on the assumption that the WG valve 14 is fully closed without play.

  After that, the energization duty ratio I duty is set to 0, whereby the supercharging operation is performed with the WG valve 14 fully closed. At time t10, when the valve opening of the WG valve 14 is instructed, the energization duty ratio I duty is set to the valve opening duty ratio IdOPN (step 16), and the valve opening operation of the WG valve 14 starts from the fully closed state without play. Be done. The subsequent operation is similar to the operation at times t1 to t5 described above.

  As described above, according to the present embodiment, the motor 31 and the rod 32 are driven in the valve opening direction from the fully closed state of the WG valve 14, and the boost pressure Pbst detected in the driven state starts to decrease. Since the detected opening degree WGA of the WG valve 14 detected from time to time is learned as the play amount equivalent opening degree WGP corresponding to the link play amount, learning of the link play amount can be appropriately performed.

  Further, after this idle learning is completed, return control is performed so that the detected opening degree WGA becomes the fully closed target opening degree WGRTN obtained by subtracting the predetermined opening amount ΔWGRTN from the idle amount equivalent opening degree WGP, and the WG valve 14 Since the state is returned to the fully closed state, the supercharging operation can be stably performed until the valve opening operation of the WG valve 14 is performed.

  Further, by setting the opening degree ΔWGRTN to the minimum value among the opening degrees that can return the WG valve 14 to the fully closed state, the fully closed target opening degree WGRTN is the play amount equivalent opening degree WGP. The WG valve 14 is controlled to the fully closed state without play by the return control. Therefore, by performing the valve opening operation of the WG valve 14 from this play-free fully closed state, the best valve opening response of the WG valve 14 can be obtained. As a result, the increased boost pressure can be reduced as quickly as possible, and in particular, sufficient acceleration performance can be obtained on the low speed side of the transmission 52.

  In addition, this invention can be implemented in various aspects, without being limited to the described embodiment. For example, in the embodiment, by executing the return control immediately after the end of the idle learning, the detection opening degree WGA is controlled to the fully closed target opening degree WGRTN, and the WG valve 14 is returned to the fully closed state. However, the present invention can be practiced without being limited thereto.

  For example, during the supercharging operation in which the learned play amount equivalent opening degree WGP is stored in the ECU 20 and the WG valve 14 is fully closed, the fully closed target opening degree based on the stored play amount equivalent opening degree WGP The WG valve 14 may be maintained in the fully closed state by setting the WGRTN and controlling the detected opening degree WGA to the fully closed target opening degree WGRTN. Thereby, even if learning of the play amount equivalent opening degree WGP is not performed for a long period of time or is not completed due to, for example, conditions of supercharging pressure and conditions of learning frequency, it has already been learned during supercharging operation. The WG valve 14 can be maintained in the fully closed state based on the play amount equivalent opening degree WGP, and the supercharging operation can be stably performed until the opening operation of the waste gate valve is performed.

  Further, in the embodiment, the WG valve 14 is controlled to a play-free fully closed state with almost no play by return control or the like, but the play may have some allowance, and thereby the WG valve 14 is completely closed. It can be controlled more reliably by the condition.

  Furthermore, although return control after play learning is performed by controlling the detection opening degree WGA to the fully closed target opening degree WGRTN, the invention is not limited thereto. For example, the motor 31 is closed in the valve closing direction after the end of play learning. In this state, it may be performed by stopping the motor 31 when it is confirmed that the lowered supercharging pressure Pbst has returned to the pressure before the idle learning.

  Further, in the embodiment, the WG valve 14 is controlled to be fully closed without play immediately after the end of the idle learning by return control, but the present invention is not limited thereto. For example, after the end of idle learning, the WG valve 14 is May be once controlled to the fully closed state where the amount of link play is large. As a result, since the WG valve 14 is strongly pressed to the valve closing position and a more stable fully closed state is obtained, it is possible to perform the supercharging operation more stably until the valve opening operation of the WG valve 14 is performed. it can. Further, in this case, for example, the execution timing of the valve opening operation of the WG valve 14 is predicted from the transition of the supercharging pressure Pbst, etc., and the WG valve 14 is controlled to the fully closed state without play prior to the predicted execution timing. Thus, the valve responsiveness of the WG valve 14 can be secured.

  Furthermore, in the embodiment, the drive mechanism for driving the WG valve 14 connects the rod 32 and the valve body 15 with the drive device 30 comprising the motor 31 as the actuator and the rod 32 by which the rotation of the motor 31 is converted into linear movement. It comprises the link mechanism 34 etc. which. These configurations are optional as long as the waste gate valve is driven electrically and through the link mechanism, and the opening of the waste gate valve is detected through the operating position of the drive device. For example, the detection of the opening degree of the WG valve 14 may be performed via the rotation angle of the motor 31 instead of the position of the rod 32 in the axial direction in the embodiment. Further, as the actuator, instead of the rotary motor of the embodiment, a linear motion motor, an electromagnetic actuator or the like may be used.

  Furthermore, although the embodiment is an example of the engine mounted on the hybrid vehicle together with the electric motor, the present invention is not limited to this, and may be applied to an engine for a vehicle not having a motor. The present invention is also applicable to an engine of a ship propulsion engine such as an outboard motor having a vertically disposed crankshaft, for example. In addition, it is possible to change suitably the composition of details within the limits of the meaning of the present invention.

1 Engine (internal combustion engine)
11 bypass passage 12 turbocharger (supercharger)
121 turbine 14 WG valve (waste gate valve)
20 ECU (control means, learning means)
23 Valve opening sensor (opening detection means)
27 Supercharging pressure sensor (supercharging pressure detection means)
30 Drive 31 Motor (Actuator, Drive)
32 rod (drive unit)
34 Link mechanism WGA detection opening (opening detected by opening detection means)
Pbst boost pressure WGO valve opening (waste gate valve opening)
WGP play amount equivalent opening WGRTN fully closed target opening

Claims (3)

A supercharger for supercharging intake air and a bypass passage bypassing a turbine of the supercharger, and being connected to a drive including an electric actuator via a link mechanism, supercharging pressure by the supercharger A control device for an internal combustion engine having a waste gate valve for adjusting
Opening degree detection means for detecting the opening degree of the waste gate valve via the operating position of the drive device;
Boost pressure detection means for detecting the boost pressure;
Control means for controlling the opening degree of the waste gate valve by controlling the actuator;
With the actuator being driven in the valve opening direction from the fully closed state of the waste gate valve, the detected opening detected by the opening detection means when the detected supercharging pressure starts to decrease And learning means for learning as a play amount equivalent opening degree corresponding to the play amount of the link mechanism,
The control means causes the waste gate valve to return to the fully closed state after learning of the play amount equivalent opening degree is completed, so that the detected opening degree is a predetermined valve closing side than the play amount equivalent opening degree. A control device for an internal combustion engine, which controls the actuator such that the target position is fully closed when the valve is closed . The storage device further includes storage means for storing the learned amount-of-play equivalent opening degree,
The control means is configured to maintain the waste gate valve in the fully closed state during the supercharging operation in which the waste gate valve is in the fully closed state, so that the detected opening degree is greater than the stored play amount equivalent opening degree. The control device for an internal combustion engine according to claim 1, wherein the actuator is controlled to be a predetermined fully closed target position on the valve closing side. The control device for an internal combustion engine according to claim 1 or 2 , wherein the predetermined fully closed target opening degree is set on the valve closing side in the vicinity of the play amount equivalent opening degree .

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