JP6236983B2 - Supercharging pressure control device and supercharging pressure control method for an internal combustion engine with a supercharger - Google Patents

Description

  The present invention relates to an apparatus and a method for controlling the supercharging pressure of an internal combustion engine with a supercharger.

  2. Description of the Related Art An internal combustion engine with a supercharger that adjusts a supercharging pressure by flowing a part of exhaust gas through a bypass passage that bypasses an exhaust turbine is known. In such an internal combustion engine, the flow rate of the gas flowing through the bypass passage is adjusted by a waste gate valve. In order to increase the supercharging pressure, the flow rate of the gas flowing through the bypass passage is reduced by reducing the opening of the waste gate valve.

  If the opening of the waste gate valve is inaccurate, the supercharging pressure cannot be precisely controlled. In particular, if the waste gate valve cannot be fully closed, a sufficient boost pressure may not be obtained.

  Therefore, in Patent Document 1, the waste gate valve is fully closed by using an electric actuator (electric motor) and performing feedback control so that the gear angle detected by the sensor matches the target gear angle (valve fully closed angle). I have to.

JP 2012-0676798 A

  However, in the method of Patent Document 1, when the fully closed position (target position) of the waste gate valve changes from the beginning for some reason, the waste gate valve cannot be fully closed. That is, the turbo housing expands or contracts due to the influence of the temperature change in the surrounding environment, and the position of the valve seat changes slightly. In addition, the position of the valve seat slightly changes due to wear over time. The waste gate valve cannot be fully closed even if there is an error in the sensor signal.

  The present invention has been made paying attention to such conventional problems. An object of the present invention is to provide a supercharging pressure control device and a supercharging pressure control method for an internal combustion engine with a supercharger that can reliably fully close a waste gate valve.

  The present invention solves the above problems by the following means.

  One embodiment of a supercharging pressure control device for an internal combustion engine with a supercharger according to the present invention includes a wastegate valve that adjusts a flow rate of a gas flowing in a bypass passage that bypasses an exhaust turbine, and a linkage mechanism that is attached to a turbine housing. And an actuator that is connected to the waste gate valve to adjust the opening degree of the waste gate valve, and controls the supercharging pressure of the internal combustion engine with a supercharger. Then, when there is an opening adjustment unit that adjusts the opening of the waste gate valve based on a deviation between the actual opening of the waste gate valve and the target opening, and a full closing command of the waste gate valve A near-close vicinity determining unit that determines whether or not the actual opening of the waste gate valve is smaller than a predetermined opening near the fully closed; and the actual opening of the waste gate valve is more than a predetermined opening near the fully closed If it is smaller, a fully-closed control unit that releases the opening adjustment by the opening adjustment unit and closes the waste gate valve with a predetermined operation amount so that the waste gate valve is seated on the valve seat And including.

  According to this aspect, when the target opening is fully closed, when the actual opening is smaller than the predetermined opening near the fully closed, the feedback control is canceled, and the operation amount is set in advance. Since the waste gate valve is controlled in the closing direction, the waste gate valve is pressed against the valve seat and is surely fully closed.

FIG. 1 is an enlarged view illustrating the vicinity of a supercharger of an internal combustion engine with a supercharger to which a supercharging pressure control device according to the present invention is applied. FIG. 2 is a flowchart for explaining a routine for obtaining the actual opening of the supercharging pressure control device for the supercharged internal combustion engine. FIG. 3 is a flowchart illustrating a routine for obtaining an actuator operation amount (operation duty) of a supercharging pressure control device for an internal combustion engine with a supercharger. FIG. 4 is a diagram illustrating a map for obtaining the integral gain. FIG. 5 is a diagram illustrating a map for obtaining the proportional gain. FIG. 6 is a diagram illustrating a map for obtaining the exhaust acting force duty. FIG. 7 is a flowchart for explaining a near-close determination routine of a supercharging pressure control device for an internal combustion engine with a supercharger. FIG. 8 is a flowchart for explaining a control routine in a valve opening / closing direction of a supercharging pressure control device for an internal combustion engine with a supercharger. FIG. 9 is a flowchart for explaining a learning permission routine of a supercharging pressure control device for an internal combustion engine with a supercharger. FIG. 10 is a flowchart for explaining a fully closed position control routine of the supercharging pressure control device for the supercharger-equipped internal combustion engine. FIG. 11 is a flowchart for explaining a fully closed position sensor voltage update routine of a supercharging pressure control device for an internal combustion engine with a supercharger.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(Fully closed position control of waste gate valve)
FIG. 1 is an enlarged view illustrating the vicinity of a supercharger of an internal combustion engine with a supercharger to which a supercharging pressure control device according to the present invention is applied.

  An exhaust passage 101 and a bypass passage 102 are formed in the housing 100 of the supercharger 10 of the internal combustion engine. The internal combustion engine supercharger 10 includes an exhaust turbine 111, an intake compressor (not shown), and a waste gate valve 112.

  The bypass passage 102 is a gas passage that bypasses the exhaust turbine 111. The bypass passage 102 branches from the exhaust passage 101 upstream of the exhaust turbine 111 and joins the exhaust passage 101 downstream of the exhaust turbine 111.

  The exhaust turbine 111 is provided in the exhaust passage 101. The exhaust turbine 111 is provided coaxially with an intake compressor (not shown). The exhaust turbine 111 is rotationally driven by exhaust flowing through the exhaust passage 101.

The waste gate valve 112 is provided at the gate ( exit ) 12 a of the bypass passage 102. The waste gate valve 112 has its opening degree adjusted by the actuator 15 to control the flow rate of the gas flowing through the bypass passage 102.

  The actuator 15 is attached to the turbine housing 100. The actuator 15 is connected to the waste gate valve 112 via the link mechanism 16. The actuator 15 is a DC motor, for example.

  The link mechanism 16 includes a stroke rod 161, a rotation rod 162, a joint 163, and a pivot 164. The stroke rod 161 has a rack gear (not shown) at one end (the lower end in FIG. 1). The rack gear meshes with a pinion gear (not shown) of the actuator 15. When the pinion gear of the actuator 15 rotates, the stroke rod 161 strokes up and down as indicated by an arrow A1 in FIG. The rotating rod 162 is fixed to the waste gate valve 112. The rotating rod 162 rotates around the pivot 164 as indicated by an arrow A2 in FIG. The stroke rod 161 and the rotation rod 162 are connected via a joint 163. Since the stroke rod 161 strokes up and down and the pivot rod 162 pivots about the pivot 164, an error occurs in the positions of both ends. Therefore, the joint 163 has a built-in error absorbing mechanism. For example, the error may be absorbed by a double joint, or the error may be absorbed by a long hole and a rod inserted into the long hole.

  With this configuration, when the actuator 15 is operated and the stroke rod 161 strokes, the rotation rod 162 rotates and the opening degree of the waste gate valve 112 is adjusted. The opening degree of the waste gate valve 112 (stroke amount of the stroke rod 161) is detected by an opening degree sensor 15a built in the actuator 15.

  Here, in order to facilitate understanding of the embodiment, the gist of the embodiment will be described.

  Recently, the waste gate valve may be controlled by an electric actuator to precisely control the supercharging pressure. More specifically, the opening degree of the waste gate valve is controlled by detecting the opening degree of the waste gate valve with a sensor and performing feedback control so that the detected value matches the target value.

  However, in feedback control, when the fully closed position (target position) of the waste gate valve changes from the beginning due to some factor, the waste gate valve cannot be fully closed. That is, the turbo housing expands or contracts due to the influence of the temperature change in the surrounding environment, and the position of the valve seat changes slightly. In addition, the position of the valve seat slightly changes due to wear over time. The waste gate valve cannot be fully closed even if there is an error in the sensor signal. In such a case, since the waste gate valve cannot be fully closed, the inventors have found that a sufficient supercharging pressure may not be obtained.

  In view of such knowledge, the inventors cancel the feedback control and determine in advance when the target opening is fully closed and when the target opening reaches a predetermined opening (open near the fully closed position). By closing the waste gate valve with the operated amount, the waste gate valve is securely seated on the valve seat. Hereinafter, the specific operation of the supercharging pressure control device for the supercharged internal combustion engine will be described focusing on the operation of the controller.

  FIG. 2 is a flowchart for explaining a routine for obtaining the actual opening of the supercharging pressure control device for the supercharged internal combustion engine.

  In step S111, the controller calculates an actual opening degree vACTWG [m] of the waste gate valve 112.

  FIG. 3 is a flowchart illustrating a routine for obtaining an actuator operation amount (operation duty) of a supercharging pressure control device for an internal combustion engine with a supercharger.

  In step S121, the controller determines whether or not the fully closed vicinity determination flag fWGCLOSERQ is zero (that is, the opening degree of the waste gate valve 112 is not close to the fully closed state). This flag fWGCLOSERQ is set in a full-close vicinity determination routine described later, but its initial value is zero. If the determination result is positive, the controller moves the process to step S122. If the determination result is negative, the controller moves the process to step S125.

  In step S122, the controller calculates an opening deviation vERRWG [m].

  The target opening degree vTGWG [m] is set based on the operating state. The actual opening degree vACTWG [m] is detected by the opening degree sensor.

  In step S123, the controller calculates an opening degree deviation integrated value vERRWGI [m].

  The integral gain vIGAIN is a value obtained by searching the map mIGAIN illustrated in FIG. 4 using the opening degree deviation vERRWG and the engine speed vNE [rpm]. The map mIGAIN is created in advance by adaptation.

  In step S124, the controller calculates an actuator operation duty vWGDUTY [-].

  The proportional gain vPGAIN is a value obtained by searching the map mPGAIN illustrated in FIG. 5 using the opening degree deviation vERRWG and the engine speed vNE [rpm]. The map mPGAIN is created in advance by adaptation.

  The exhaust force duty vEXHPDUTY is a value obtained by searching the map mEXHPDUTY illustrated in FIG. 6 with the target opening degree vTGWG and the engine speed vNE [rpm]. The map mEXHPDUTY is created in advance by adaptation.

  In step S125, the controller calculates an actuator operation duty vWGDUTY [-].

  The fully-closed operation duty mWGCLOSEDUTY checks the operation amount that is pressed to the fully-closed position in advance, and the wastegate valve 112 and the actuator 15 are caused by an impact when the wastegate valve 112 is seated on the valve seat of the turbo housing. Set the amount of operation that will not cause damage.

  FIG. 7 is a flowchart for explaining a near-close determination routine of a supercharging pressure control device for an internal combustion engine with a supercharger.

  In step S131, the controller determines whether or not a full-close command has been issued, that is, whether or not the target opening degree vTGWG is zero. If the determination result is positive, the controller moves the process to step S132. If the determination result is negative, the controller exits the process.

  In step S132, the controller determines whether or not the actual opening degree vACTWG is larger than the fully closed vicinity opening degree mWGFUCLOSE. The fully closed opening degree mWGFUCLOSE is set in advance. If the determination result is positive, the controller moves the process to step S133. If the determination result is negative, the controller moves the process to step S134.

  In step S133, the controller sets zero to the fully closed vicinity determination flag fWGCLOSERQ.

  In step S134, the controller sets “1” to the fully closed vicinity determination flag fWGCLOSERQ.

  FIG. 8 is a flowchart for explaining a control routine in a valve opening / closing direction of a supercharging pressure control device for an internal combustion engine with a supercharger.

  In step S141, the controller determines whether or not the fully closed vicinity determination flag fWGCLOSERQ is “1”. If the determination result is negative, the controller moves the process to step S142. If the determination result is positive, the controller moves the process to step S144.

  In step S142, the controller determines whether or not the actual opening degree vACTWG is smaller than the target opening degree vTGWG. If the determination result is positive, the controller moves the process to step S143. If the determination result is negative, the controller moves the process to step S144.

  In step S143, the controller controls the waste gate valve 112 in the opening direction.

  In step S144, the controller controls the waste gate valve 112 in the closing direction.

  If an opening degree command that is not a fully closed command is issued to the waste gate valve 112 by the above routine, steps S121 → S122 → S123 → S124 are processed, and the actual opening vACTWG of the waste gate valve 112 is processed. Feedback control (PI control) is executed based on the deviation vERRWG between the target opening degree vTGWG and the target opening degree vTGWG, and the actual opening degree vACTWG is controlled to coincide with the target opening degree vTGWG.

  Even if there is a fully closed command (Yes in step S131), while the actual opening degree vACTWG is larger than the fully closed opening degree mWGFUCLOSE (Yes in step S132), steps S121 → S122 → S123 → S124 are continued, Based on the deviation vERRWG between the actual opening vACTWG and the target opening vTGWG of the waste gate valve 112, feedback control (PI control) is executed.

  When the actual opening vACTWG becomes smaller than the fully closed opening mWGFUCLOSE (No in step S132), steps S121 → S125 are processed, the feedback control is released, and the waste gate valve 112 is moved to the turbo housing valve seat. The waste gate valve 112 is controlled in the closing direction so that the waste gate valve 112 and the actuator 15 are not damaged by the impact when seated, and the waste gate valve 112 is seated on the valve seat and is fully closed.

  As described above, according to the present embodiment, when the actual opening vACTWG of the waste gate valve 112 is larger than the predetermined opening mWGFUCLOSE near the fully closed position, the deviation vERRWG between the actual opening vACTWG and the target opening vTGWG is used. Since the feedback control (PI control) is executed, the actual opening degree vACTWG accurately matches the target opening degree vTGWG.

  Further, simply by performing feedback control, when the fully closed position (target position) of the waste gate valve changes from the beginning due to some factor, the waste gate valve cannot be fully closed. That is, the turbo housing expands or contracts due to the influence of the temperature change in the surrounding environment, and the position of the valve seat changes slightly. In addition, the position of the valve seat slightly changes due to wear over time. The waste gate valve cannot be fully closed even if there is an error in the sensor signal. In such a case, since the waste gate valve cannot be fully closed, there is a possibility that sufficient supercharging pressure cannot be obtained.

  On the other hand, in the present embodiment, when the target opening is fully closed, if the actual opening vACTWG becomes smaller than the opening near the fully closed mWGFUCLOSE, the feedback control is canceled and preset. The waste gate valve 112 is controlled in the closing direction by the operation amount. Since it did in this way, the waste gate valve 112 will be reliably pressed by the valve seat, and will be in a fully closed state. For this reason, the required supercharging pressure can be ensured, and the required torque can be realized. In addition, by performing feedback control (PI control) until the predetermined opening degree mWGFUCLOSE, the waste gate valve 112 can be closed with a quick response, so that the response of the supercharging pressure can be accelerated.

  The force acting on the waste gate valve 112 changes according to the change in the exhaust amount due to the operating state. In order to reliably close the waste gate valve 112, it is necessary to press the waste gate valve 112 in the closing direction with a force corresponding to the displacement. On the other hand, in the present embodiment, the force that the exhaust acts on the waste gate valve 112 is added to control the waste gate valve 112 in the closing direction, so that the waste gate valve 112 can be reliably fully closed.

  Further, when the actual opening vACTWG becomes smaller than the fully closed opening mWGFUCLOSE, the operation is controlled with an operation amount that does not damage the waste gate valve 112 and the actuator 15 due to the impact when the waste gate valve 112 is seated on the valve seat. Damage to the waste gate valve 112 and the actuator 15 can be prevented.

(Learn the fully closed position of the waste gate valve)
FIG. 9 is a flowchart for explaining a learning permission routine of a supercharging pressure control device for an internal combustion engine with a supercharger.

  In step S211, the controller determines whether or not the battery voltage is greater than a predetermined value (learning permission voltage mWGVB). The learning permission voltage mWGVB is set to a voltage that can drive the waste gate valve 112. If the determination result is positive, the controller moves the process to step S212. If the determination result is negative, the controller moves the process to step S217.

  In step S212, the controller determines whether or not the starter switch has been turned from ON to OFF, that is, whether or not the internal combustion engine has been started. If the determination result is positive, the controller moves the process to step S213. If the determination result is negative, the controller moves the process to step S217.

  In step S213, the controller determines whether or not a predetermined time mSOKE has elapsed since the previous trip. Here, the predetermined time mSOKE is a time during which it can be determined that the internal combustion engine is in a cold state. This may be set by acquiring water temperature data after stopping the internal combustion engine by experiment. If the determination result is positive, the controller moves the process to step S214. If the determination result is negative, the controller moves the process to step S217.

  In step S214, the controller determines whether or not the internal combustion engine is idling. If the determination result is positive, the controller moves the process to step S215. If the determination result is negative, the controller moves the process to step S217.

  In step S215, the controller determines whether or not the opening sensor 15a has failed. If the determination result is positive, the controller moves the process to step S216. If the determination result is negative, the controller moves the process to step S217.

  In step S216, the controller sets the learning permission flag fLEARN to “1”.

  In step S217, the controller sets a learning permission flag fLEARN to zero.

  FIG. 10 is a flowchart for explaining a fully closed position control routine of the supercharging pressure control device for the supercharger-equipped internal combustion engine.

  In step S221, the controller determines whether or not the learning permission flag fLEARN is “1”. If the determination result is positive, the controller moves the process to step S222. If the determination result is negative, the controller exits the process.

  In step S222, the controller controls the waste gate valve 112 to the fully closed position. Specifically, as described above, while the actual opening vACTWG is larger than the fully closed opening mWGFUCLOSE, feedback control (PI control) is performed, and the actual opening vACTWG is more than the closing near opening mWGFUCLOSE. When it becomes smaller, the feedback control is canceled and the waste gate valve 112 is controlled in the closing direction with a preset operation amount.

  FIG. 11 is a flowchart for explaining a fully closed position sensor voltage update routine of a supercharging pressure control device for an internal combustion engine with a supercharger.

  In step S231, the controller determines whether or not the state where the absolute value vERRWGA of the opening deviation vERRWG is smaller than the fully closed position convergence determination value mWG0JG [m] has continued for a predetermined time (fully closed position convergence determination time mLEARNT [s]). Determine. Note that the fully closed position convergence determination value mWG0JG [m] and the fully closed position convergence determination time mLEARNT [s] are adapted in advance through experiments. If the determination result is positive, the controller moves the process to step S232. If the determination result is negative, the controller exits the process.

  In step S232, the controller updates the fully closed position sensor voltage value vWG0POS [V]. In step S111 in FIG. 2, the fully closed position sensor voltage value vWG0POS is used. When the fully closed position sensor voltage value vWG0POS [V] is updated, or when each condition of the learning permission routine (FIG. 9) is not satisfied and the learning permission flag fLEARN becomes zero before the update, After that, it is desirable not to set the learning permission flag fLEARN. This is to prevent erroneous learning.

  By doing in this way, the waste gate valve 112 can be surely set to the fully closed position, so that the reference position (fully closed position) can be learned with high accuracy. As a result, the required supercharging pressure control can be realized.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  For example, “detection” includes not only direct detection but also indirect detection, ie estimation from others.

  Moreover, the above-mentioned map and table are only examples. It is set as appropriate according to the specifications of the internal combustion engine.

  The above embodiments can be appropriately combined.

DESCRIPTION OF SYMBOLS 10 Supercharger 100 Housing 101 Exhaust passage 102 Bypass passage 111 Exhaust turbine 112 Waste gate valve (WGV)
15 Actuator Step S124 Opening Adjustment Unit Step S125 Fully Closed Control Unit Step S132 Fully Closed Near Determination Unit

Claims (5)

A wastegate valve for adjusting the flow rate of the gas flowing through the bypass passage that bypasses the exhaust turbine;
An actuator attached to the turbine housing and connected to the waste gate valve via a link mechanism to adjust the opening of the waste gate valve;
A supercharging pressure control device for an internal combustion engine with a supercharger for controlling the supercharging pressure of the internal combustion engine with a supercharger, comprising:
An opening adjustment unit that adjusts the opening of the waste gate valve based on a deviation between the actual opening and the target opening of the waste gate valve;
When there is a full-close command of the waste gate valve, a full-close vicinity determining unit that determines whether or not the actual opening of the waste gate valve is smaller than a predetermined opening near the full close;
When the actual opening of the waste gate valve is smaller than a predetermined opening in the vicinity of full closure, the opening adjustment by the opening adjustment unit is canceled, and the waste gate valve is seated on the valve seat, A fully-closed control unit for closing the waste gate valve by a predetermined operation amount;
A supercharging pressure control device for an internal combustion engine with a supercharger. The supercharging pressure control device for an internal combustion engine with a supercharger according to claim 1,
The fully-closed control unit adds the force that the exhaust acts on the waste gate valve to control the waste gate valve in the closing direction.
A supercharging pressure control device for an internal combustion engine with a supercharger. In the supercharging pressure control device for an internal combustion engine with a supercharger according to claim 1 or 2,
Based on the deviation between the current signal of the sensor that outputs a signal corresponding to the opening of the waste gate valve and the fully closed learning signal that learned the fully closed position of the waste gate valve, the current actual opening is detected. An actual opening detection unit;
A fully-closed position learning unit for learning the fully-closed position of the waste gate valve, with the waste gate valve seated on the valve seat by the fully-closed control unit;
A supercharging pressure control device for an internal combustion engine with a supercharger. The supercharging pressure control device for an internal combustion engine with a supercharger according to any one of claims 1 to 3,
The predetermined operation amount is an operation amount that does not damage the waste gate valve and the actuator due to an impact when the waste gate valve is seated on a valve seat.
A supercharging pressure control device for an internal combustion engine with a supercharger. A wastegate valve for adjusting the flow rate of the gas flowing through the bypass passage that bypasses the exhaust turbine;
An actuator attached to the turbine housing and connected to the waste gate valve via a link mechanism to adjust the opening of the waste gate valve;
A supercharging pressure control method for an internal combustion engine with a supercharger for controlling a supercharging pressure of the internal combustion engine with a supercharger, comprising:
An opening adjustment procedure for adjusting the opening of the waste gate valve based on the deviation between the actual opening and the target opening of the waste gate valve;
When there is a full-close command of the waste gate valve, a full-close vicinity determination procedure for determining whether or not the actual opening of the waste gate valve is smaller than a predetermined opening near the full close;
When the actual opening of the waste gate valve is smaller than a predetermined opening in the vicinity of full closure, the opening adjustment by the opening adjustment procedure is canceled, so that the waste gate valve is seated on the valve seat, A fully-closed control procedure for closing the waste gate valve with a predetermined operation amount;
A supercharging pressure control method for an internal combustion engine with a supercharger.

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