JP2016048040A - Control device of waste gate valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a waste gate valve which can suppress an increase of the vibration of a valve body of the waste gate valve in an opening/closing direction accompanied by the action of the exhaust pulsation of an internal combustion engine.SOLUTION: On condition that an opening command value of a waste gate valve 14 is constant, and when a valve body 17 of the valve 14 receives an influence of an internal combustion engine 1, and a variation amount (magnitude of vibration in an opening/closing direction) of the valve body 17 is not smaller than a determination value, an electronic control device 21 performs minimum vibration opening investigation processing for searching for an opening (minimum vibration opening) of the valve body 17 in which a magnitude of the vibration reaches a minimum value. Furthermore, the electronic control device 21 adds the adjustment of the opening of the valve body 17 of the waste gate valve 14 to the minimum vibration opening which is searched for via the minimum vibration opening investigation processing. By this constitution, an increase of the vibration of the valve body 17 of the waste gate valve 14 can be suppressed, and the generation of noise accompanied by the increase of the vibration can be also suppressed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device for a waste gate valve.

  As disclosed in Patent Document 1, in an internal combustion engine including an exhaust turbine type supercharger, a turbine wheel of the supercharger is provided in an exhaust passage, and the compressor wheel that rotates integrally with the turbine wheel is provided in the intake passage. The air is supercharged.

  A bypass passage that bypasses the turbine wheel is connected to the exhaust passage of the internal combustion engine, and a waste gate valve is provided in the bypass passage. And if the opening degree of the valve body of a waste gate valve is adjusted, the flow volume of the exhaust gas which passes the turbine wheel of a supercharger will change, and the rotational speed of a turbine wheel (compressor wheel) will change in connection with it. In this way, the supercharging pressure is adjusted by changing the rotational speed of the turbine wheel (compressor wheel).

  Patent Document 1 discloses that when detecting an abnormality of an air-fuel ratio sensor provided in an exhaust passage of an internal combustion engine, the waste gate valve is controlled to be opened.

JP2013-241892A

  By the way, since exhaust pulsation occurs in the exhaust passage of the internal combustion engine, when the valve body of the waste gate valve is opened, the exhaust pulsation acts on the valve body, and the waste gate valve operates along with the exhaust pulsation. The valve body vibrates in the opening / closing direction.

  The magnitude of the vibration in the opening / closing direction of the valve body of the waste gate valve at this time depends on the angle of the portion (pressure receiving surface) that receives the exhaust pressure in the valve body, and the valve body uses the elastic force of the spring. The thing that opens and closes depends on the degree of expansion and contraction of the spring. It should be noted that the angle of the portion (pressure receiving surface) that receives the exhaust pressure in the valve body of the waste gate valve and the degree of expansion and contraction of the spring of the valve vary depending on the opening degree of the valve body of the waste gate valve.

  Therefore, depending on the degree of opening of the valve body of the waste gate valve, in other words, depending on the angle of the portion (pressure receiving surface) that receives the exhaust pressure in the valve body, and depending on the degree of expansion and contraction of the spring of the valve, it is caused by exhaust pulsation. There is a possibility that the vibration of the valve body of the waste gate valve becomes large, and there is also a possibility that an abnormal noise accompanying the vibration is generated.

  An object of the present invention is to provide a control device for a waste gate valve that can suppress an increase in vibration in the opening / closing direction of the valve body of the waste gate valve due to the action of exhaust pulsation.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A waste gate valve control device that solves the above problems includes a waste gate valve provided in a bypass passage connected to bypass an exhaust passage of an internal combustion engine to bypass a turbine wheel of a supercharger, and a valve body of the waste gate valve And a control unit that obtains an opening command value of the waste gate valve and controls the opening of the valve body based on the opening command value.

  When the valve body of the waste gate valve is opened, exhaust pulsation generated in the exhaust passage of the internal combustion engine acts on the valve body, so that the valve body vibrates in the opening / closing direction. Since the magnitude of the vibration in the opening / closing direction of the valve body of the waste gate valve at this time varies depending on the opening degree of the valve body, the vibration may increase depending on the opening degree.

  For this reason, the control unit determines the amount of fluctuation of the opening degree of the waste gate valve body obtained by using the sensor under the condition that the opening degree command value is constant (the magnitude of vibration in the opening and closing direction of the valve body). ) Is equal to or greater than the determination value, the opening of the valve body is changed within a predetermined range. Further, in the process of changing the opening degree of the valve body, the control unit obtains the fluctuation amount of the valve body for each different opening degree in the changing process, and determines the opening degree of the valve body of the waste gate valve. The opening command value is adjusted to a value corresponding to the opening degree so that the opening degree is controlled to be the minimum value.

  Therefore, as described above, even if the fluctuation amount (the magnitude of vibration in the opening / closing direction of the valve body) of the valve body opening degree of the waste gate valve becomes equal to or greater than the determination value due to the exhaust pulsation, By controlling the opening degree of the valve body to the minimum vibration opening degree, an increase in the vibration of the valve body can be suppressed. Furthermore, it is possible to suppress the generation of abnormal noise accompanying the increase in the vibration of the valve body of the waste gate valve.

1 is a schematic diagram showing an internal combustion engine to which a waste gate valve control device is applied. The flowchart which shows the procedure which adjusts the opening degree of a waste gate valve to the minimum vibration opening degree. The flowchart which shows the detailed execution procedure of the minimum vibration opening degree investigation process.

Hereinafter, an embodiment of a control device for a waste gate valve will be described with reference to FIGS.
In the internal combustion engine 1 shown in FIG. 1, a compressor wheel 4 a of an exhaust turbine supercharger (turbocharger) 4 is provided in an intake passage 3 connected to a combustion chamber 2. Further, a throttle valve 6 that opens and closes to adjust the amount of air supplied to the combustion chamber 2 (intake air amount) is provided downstream of the compressor wheel 4 a in the intake passage 3. Air that has passed through the intake passage 3 is supplied to the combustion chamber 2 of the internal combustion engine 1, and an amount of fuel corresponding to the amount of air is injected from the fuel injection valve 7. Then, the crankshaft 10 that is the output shaft of the internal combustion engine 1 rotates through the reciprocation of the piston 8 by the combustion energy when the fuel is burned in the combustion chamber 2. In the internal combustion engine 1, the output torque is increased by increasing the amount of air supplied to the combustion chamber 2 and correspondingly increasing the amount of fuel supplied to the combustion chamber 2.

  On the other hand, the exhaust gas after the fuel combusts in the combustion chamber 2 is sent out to an exhaust passage 9 connected to the combustion chamber 2. The exhaust passage 9 is provided with a turbine wheel 4 b of the turbocharger 4. When the exhaust gas flowing through the exhaust passage 9 passes through the turbine wheel 4b, the turbine wheel 4b rotates and the compressor wheel 4a also rotates. Is done. Thus, in the internal combustion engine 1 that receives supercharging of air by the turbocharger 4, the pressure (supercharging pressure) upstream of the throttle valve 6 in the intake passage 3 increases as the rotational speed of the turbocharger 4 increases. As the boost pressure increases, the amount of fuel and air that can be supplied to the combustion chamber 2 increases, so that the output torque of the internal combustion engine 1 can be increased.

  The internal combustion engine 1 includes a bypass passage 13 that connects an upstream portion and a downstream portion of the turbine wheel 4 b in the exhaust passage 9, and a waste whose opening is adjusted so that the gas flow area of the bypass passage 13 can be varied. And a gate valve 14. As the opening degree of the waste gate valve 14 is increased, the flow rate of the exhaust gas flowing through the turbine wheel 4b is decreased. Therefore, the rotational speed of the turbocharger 4 is suppressed low, and the supercharging pressure of the internal combustion engine 1 is decreased. Conversely, as the opening degree of the waste gate valve 14 is decreased, the flow rate of the exhaust gas flowing through the turbine wheel 4b increases, so that the rotational speed of the turbocharger 4 increases and the supercharging pressure of the internal combustion engine 1 increases.

  The waste gate valve 14 includes a valve body 17 that can rotate around a pin 16, a rod 18 that is engaged with the valve body 17, and an actuator 19 that can move the rod 18 in the longitudinal direction. Yes. In the waste gate valve 14, the opening degree for the valve body 17 to rotate around the pin 16 to change the gas flow area of the bypass passage 13 by moving the rod 18 in the longitudinal direction by the actuator 19. Adjustments are made. The actuator 19 is a negative pressure type driven by using a negative pressure and a spring generated in the internal combustion engine 1, and is driven by using a positive pressure and a spring generated in the intake passage 3 of the internal combustion engine 1. It is conceivable to use a positive pressure type or an electric type driven by a motor or the like.

Next, the electrical configuration of the control device for the waste gate valve 14 will be described.
The apparatus includes an electronic control device 21 for performing various controls of the internal combustion engine 1. The electronic control device 21 includes a CPU that executes arithmetic processing related to the various controls, a ROM that stores programs and data necessary for the control, a RAM that temporarily stores arithmetic results of the CPU, and the like. It has input / output ports for inputting / outputting signals.

Various sensors shown below are connected to the input port of the electronic control unit 21.
An accelerator position sensor 22 that detects an operation amount (accelerator operation amount) of the accelerator pedal 15 that is operated by a driver of the vehicle on which the internal combustion engine 1 is mounted.

A throttle position sensor 23 that detects the opening of the throttle valve 6 (throttle opening).
A supercharging pressure sensor 24 that detects the pressure (supercharging pressure) of the upstream portion of the throttle valve 6 and the downstream portion of the compressor wheel 4a in the intake passage 3.

A crank position sensor 25 for detecting the rotational speed of the crankshaft 10 of the internal combustion engine 1.
An intake air temperature sensor 26 that detects the temperature (intake air temperature) of the air upstream of the compressor wheel 4a in the intake passage 3.

An atmospheric pressure sensor 27 for detecting atmospheric pressure.
A stroke sensor 28 that detects the movement distance (corresponding to the opening degree of the waste gate valve 14) from the end of the movement range of the rod 18 in the waste gate valve 14.

  Connected to the output port of the electronic control unit 21 are a drive circuit for the throttle valve 6, a drive circuit for the fuel injection valve 7, a drive circuit for the waste gate valve 14 (actually the actuator 19), and the like.

  Based on the detection signals input from the various sensors, the electronic control device 21 grasps the required engine operating state and the actual engine operating state, and based on these, command signals are sent to various drive circuits connected to the output port. Is output. In this way, the supercharging pressure control, the throttle opening control, the fuel injection amount control, and the like in the internal combustion engine 1 are performed through the electronic control device 21.

In the internal combustion engine 1 provided with the turbocharger 4, the output torque is controlled through the electronic control device 21 as follows.
That is, a target output torque To that is an output torque required for the internal combustion engine 1 is obtained based on the accelerator operation amount detected by the accelerator position sensor 22 and the engine rotational speed obtained from the detection signal of the crank position sensor 25. . Further, the target intake air amount GAt and the target boost pressure Pt of the internal combustion engine 1 are obtained based on the target output torque To. This target boost pressure Pt is used as an index (target value) when adjusting the actual boost pressure of the internal combustion engine 1. The throttle valve is controlled so that the intake air amount of the internal combustion engine 1 is controlled to the target intake air amount GAt and the actual boost pressure detected by the boost pressure sensor 24 is controlled to the target boost pressure Pt. The opening degree of 6 and the rotational speed of the turbocharger 4 are adjusted.

  The rotation speed of the turbocharger 4 is adjusted here by changing the opening degree of the valve body 17 by the operation of the actuator 19 of the waste gate valve 14. The operation of the actuator 19 for controlling the opening degree of the valve element 17 of the waste gate valve 14 is performed based on an opening degree command value determined from the target supercharging pressure Pt and the like. By the operation of the actuator 19, the opening degree of the valve body 17 of the waste gate valve 14 is adjusted to an opening degree corresponding to the opening degree command value.

  On the other hand, the fuel injection amount of the fuel injection valve 7 in the internal combustion engine 1 is performed based on the intake air amount and the target air fuel ratio of the engine 1. The intake air amount of the internal combustion engine 1 is obtained based on, for example, the actual boost pressure, the throttle opening, and the engine speed. The target air-fuel ratio is a target value of the air-fuel ratio when fuel is burned in the combustion chamber 2 of the internal combustion engine 1, and is variably set based on the engine operating state such as the accelerator operation amount and the engine speed. . Then, based on the intake air amount of the internal combustion engine 1 and the target air fuel ratio, an injection amount command value Q that is a command value of the fuel amount injected from the fuel injection valve 7 is calculated. By driving the fuel injection valve 7 so that an amount of fuel corresponding to the injection amount command value Q is injected, the air-fuel ratio of the internal combustion engine 1 corresponds to the intake air amount so that it is adjusted to the target air-fuel ratio. An amount of fuel is injected from the fuel injection valve 7.

  Accordingly, when the target output torque To changes based on the change in the accelerator operation amount by the driver, the intake air amount, the actual boost pressure, and the fuel injection amount are adjusted in accordance with the target output torque To at that time. The output torque of the internal combustion engine 1 is controlled to the target output torque To.

  Next, the control of the opening degree of the valve body 17 of the waste gate valve 14 performed through the electronic control device 21 will be described in detail. At this time, the electronic control device 21 functions as a control unit for controlling the opening degree of the valve body 17 of the waste gate valve 14.

  The opening degree of the valve body 17 of the waste gate valve 14 is controlled by operating the actuator 19 based on the opening degree command value. When the valve 14 (valve element 17) is opened through the opening degree control of the valve element 17 of the waste gate valve 14, the exhaust pulsation generated in the exhaust passage 9 of the internal combustion engine 1 causes the valve element 17 of the waste gate valve 14 and the like. The valve element 17 of the wastegate valve 14 vibrates in the opening / closing direction with the action of the exhaust pulsation.

  The magnitude of the vibration in the opening / closing direction of the valve body 17 of the waste gate valve 14 at this time varies depending on the angle of the pressure receiving surface of the portion (valve body 17) receiving the exhaust pressure in the valve 14. Further, in the case of a pressure type (negative pressure type or positive pressure type) in which the actuator 19 of the waste gate valve 14 opens and closes by using the elastic force of the spring, it varies depending on the degree of expansion and contraction of the spring. The angle of the pressure receiving surface of the valve element 17 in the waste gate valve 14 and the degree of expansion and contraction of the spring of the valve 14 (actuator 19) vary depending on the opening of the waste gate valve 14.

  Therefore, depending on the opening degree of the valve body 17 of the waste gate valve 14, in other words, depending on the angle of the pressure receiving surface of the valve body 17 and the degree of expansion and contraction of the spring of the valve 14 (actuator 19), There is a possibility that the vibration in the opening and closing direction becomes large, and there is also a possibility that abnormal noise accompanying the vibration is generated.

  In order to deal with this, the electronic control unit 21 uses the stroke sensor 28 to change the opening degree of the valve body 17 of the waste gate valve 14 under the condition that the opening command value of the waste gate valve 14 is constant. (Corresponding to the magnitude of vibration in the opening and closing direction of the valve body 17) is obtained. When the fluctuation amount thus obtained is equal to or larger than the determination value, a minimum vibration opening degree investigation process for searching for the opening degree of the valve body 17 (hereinafter referred to as the minimum vibration opening degree) at which the fluctuation amount becomes the minimum value is executed. The opening command value is adjusted to a value corresponding to the minimum vibration opening in order to control the opening of the valve element 17 of the waste gate valve 14 to the minimum vibration opening.

  Therefore, even if the fluctuation amount of the valve element 17 of the waste gate valve 14 (the magnitude of vibration in the opening / closing direction of the valve element 17) exceeds the determination value due to the exhaust pulsation, the opening degree of the valve element 17 is increased. As described above, the increase in vibration can be suppressed by adjusting to the minimum vibration opening. Furthermore, it is possible to suppress the generation of abnormal noise accompanying the increase in the vibration of the waste gate valve 14.

Next, the operation of the control device for the waste gate valve 14 will be described.
FIG. 2 is a flowchart showing a valve control routine for adjusting the opening of the valve element 17 of the waste gate valve 14 to the minimum vibration opening found through the minimum vibration opening investigation process. This routine is periodically executed through the electronic control device 21 with a time interrupt at predetermined intervals.

  The electronic control unit 21 determines whether or not the flag F used for determining whether or not the minimum vibration opening is being investigated as “0 (not under investigation)” as the process of step 101 (S101) of the routine. Determine whether. Here, when a negative determination is made based on the flag F being “0”, the process (S102, S103) for determining whether or not the investigation of the minimum vibration opening is to be performed is performed. move on.

  The electronic control unit 21 determines whether or not the valve body 17 of the waste gate valve 14 is opened and the opening command value of the valve 14 is constant as the process of S102. If the waste gate valve 14 is closed or if the opening command value of the valve 14 is not constant, a negative determination is made in S102. In this case, the electronic control unit 21 once ends the valve control routine. On the other hand, if a positive determination is made in S102, the process proceeds to S103.

  The electronic control unit 21 determines whether or not the amount of change in the opening degree of the valve body 17 of the waste gate valve 14 (corresponding to the magnitude of vibration in the opening / closing direction of the valve body 17) is greater than or equal to the determination value as the process of S103. to decide. Note that the determination value may be an optimal value determined in advance through experiments or the like, for example, an optimal value for determining that the vibration is large enough to cause abnormal noise. Moreover, the said fluctuation | variation amount of the opening degree of the valve body 17 of the wastegate valve 14 can be calculated | required like following (A) or (B), for example.

  (A) The fluctuation amount of the detection value from when the change direction of the detection value of the stroke sensor 28 is reversed between the plus direction and the minus direction until the next reversal is represented by the fluctuation amount of the opening degree of the valve element 17. Asking. The fluctuation amount may be a value obtained by one measurement by the stroke sensor 28 or may be an average value of values obtained by a plurality of measurements by the sensor 28.

  (B) From the maximum value of the acceleration of the change in the detected value until the change direction of the detection value of the stroke sensor 28 is reversed between the plus direction and the minus direction, the opening degree of the valve element 17 The above fluctuation amount is estimated and obtained. The maximum value of the acceleration may be a value obtained by one measurement by the stroke sensor 28, or may be an average value of values obtained by a plurality of measurements by the sensor 28.

  If the variation amount of the opening degree of the valve body 17 of the waste gate valve 14 is less than the determination value, a negative determination is made in S103. In this case, the electronic control unit 21 once ends the valve control routine. On the other hand, if the fluctuation amount of the opening degree of the valve body 17 of the waste gate valve 14 is equal to or larger than the determination value, an affirmative determination is made in S103 and the process proceeds to S104. As the process of S104, the electronic control unit 21 searches for the opening degree (minimum vibration opening degree) of the valve body 17 at which the fluctuation amount (the magnitude of vibration in the opening / closing direction of the valve body 17) becomes the minimum value. Execute investigation processing.

  Thereafter, the electronic control unit 21 sets the flag F to “1 (under investigation)” as the process of S105. Accordingly, when the minimum vibration opening degree investigation process is started and the flag F is set to “1”, a negative determination is made in the subsequent S101, so that S102 to S105 are skipped and the process proceeds to S106. Since the flag F is set to “1” until the minimum vibration opening degree investigation process ends, the processes of S102 to S105 are skipped during the execution of the minimum vibration opening degree investigation process.

  In the minimum vibration opening degree investigation process of S104, the opening degree of the valve element 17 of the waste gate valve 14 is changed within a predetermined range, while the opening degree of the valve element 17 is changed for each different opening degree in the changing process. A fluctuation amount (corresponding to the magnitude of vibration in the opening / closing direction of the valve body 17) is obtained. The predetermined range is a range in which the boost pressure does not rise unacceptably due to a change in the opening degree of the valve body 17 within the range, for example, a predetermined opening degree FO of the waste gate valve 14 from a predetermined opening degree FO. The range up to the opening degree SO is raised. The predetermined opening degree SO is set to a fixed value on the closing side with respect to the opening degree of the valve body 17 immediately before the execution of the minimum starting opening degree investigation, or is variably set on the closing side with respect to the opening degree based on the opening degree. It can be considered to be a variable value.

  The minimum vibration opening degree investigation process is realized by executing the following processes (a) to (d). (A) After adjusting the valve body 17 of the waste gate valve 14 to the fully opened opening degree FO, the opening degree is fixed. (B) The amount of fluctuation of the opening degree of the valve body 17 (the magnitude of vibration in the opening and closing direction of the valve body 17) is obtained by the method of (A) or (B), and the fluctuation amount is stored. (C) Fixed after adjusting the opening degree of the valve body 17 to the closed side by a predetermined amount. (D) The above (b) and (c) are repeated until the opening degree of the valve body 17 reaches the opening degree SO.

  FIG. 3 is a flowchart showing a minimum vibration opening degree investigation routine for executing the minimum vibration opening degree investigation process. The minimum vibration opening degree investigation routine is executed through the electronic control device 21 every time the process proceeds to S104 in FIG. Note that the processing of S201 to S204 of the routine corresponds to the processing of (a) to (d) above.

  As a process of S201, the electronic control unit 21 adjusts the valve body 17 of the waste gate valve 14 to the fully opened opening degree FO, and then changes the opening degree of the valve body 17 to the closing side by a predetermined amount, and after that change. By alternately stopping the valve body 17 for a predetermined stop time at the position, the valve 14 is closed in a stepwise manner. The electronic control unit 21 obtains the amount of change in the opening degree of the valve body 17 of the waste gate valve 14 (the magnitude of vibration in the opening / closing direction of the valve body 17) during the stop time as the subsequent processing of S202, and the obtained fluctuation. The amount is stored in the memory in association with the opening when the amount of variation is obtained through the process of S203.

  Furthermore, the electronic control unit 21 determines whether or not the above-described stepwise closing operation of the valve body 17 of the waste gate valve 14 is completed as the process of S204. Specifically, it is determined whether or not the opening degree of the valve body 17 has reached the opening degree SO. If the opening degree of the valve body 17 has not reached the opening degree SO and a negative determination is made in S204, the process returns to S201. On the other hand, when the opening degree of the valve body 17 reaches the opening degree SO and a positive determination is made in S204, the process proceeds to S205.

  The electronic control unit 21 refers to the data on the opening degree and the magnitude of vibration stored in the memory as the process of S205, and among the opening degrees within the above-defined range in the valve body 17 of the waste gate valve 14, The opening at which the amount of change in the opening of the valve body 17 (the magnitude of vibration in the opening / closing direction of the valve body 17) becomes the minimum value is set as the minimum vibration opening. The electronic control device 21 thus ends the investigation of the minimum vibration opening by determining the minimum vibration opening, and ends this minimum vibration opening investigation processing routine.

  The electronic control unit 21 determines whether or not the above-described investigation of the minimum vibration opening has been completed as the processing of S106 in the valve control routine of FIG. If the determination is negative, the electronic control unit 21 once ends the valve control routine. On the other hand, if it is affirmation determination, it will progress to S107. As the processing of S107, the electronic control device 21 determines that the amount of change in the opening degree of the valve body 17 at the minimum vibration opening degree determined through the minimum vibration opening degree investigation process (FIG. 3) is the above before the minimum vibration opening degree investigation. It is determined whether or not the fluctuation amount is smaller than the fluctuation amount at the time when an affirmative determination is made in S103.

  If a positive determination is made in S107, the process proceeds to S108. The electronic control unit 21 adjusts the opening command value of the waste gate valve 14 to a value corresponding to the minimum vibration opening in order to control the opening of the valve body 17 to the minimum vibration opening as the process of S108. On the other hand, if a negative determination is made in S107, the process proceeds to S109. As the process of S109, the electronic control unit 21 returns the opening command value of the waste gate valve 14 to the value before the minimum vibration opening degree investigation (the value when the affirmative determination is made in S103).

  After the process of S108 is executed, or after the process of S109 is executed, the process proceeds to S110. The electronic control unit 21 resets the flag F to “0 (not under investigation)” as the process of S110. Thereafter, the electronic control unit 21 once ends the valve control routine.

According to the embodiment described in detail above, the following effects can be obtained.
(1) The electronic control device 21 determines the amount of fluctuation in the opening degree of the valve body 17 (the magnitude of vibration in the opening and closing direction of the valve body 17) under the condition that the opening command value of the waste gate valve 14 is constant. When the value is equal to or greater than the value, the minimum vibration opening degree investigation process for searching for the opening degree (minimum vibration opening degree) of the valve body 17 at which the fluctuation amount becomes the minimum value is executed. Furthermore, the electronic control unit 21 adjusts the opening degree of the valve body 17 to the minimum vibration opening degree found through the minimum vibration opening degree investigation process. Therefore, even when the amount of fluctuation of the opening degree of the valve element 17 due to the exhaust pulsation (the magnitude of vibration in the opening and closing direction of the valve element 17) is equal to or greater than the above-described determination value, the opening degree of the valve element 17 is described above. Thus, by adjusting to the minimum vibration opening, the increase in the vibration can be suppressed. Furthermore, it is possible to suppress the generation of abnormal noise accompanying the increase in the vibration of the valve element 17 of the waste gate valve 14.

  (2) In the minimum vibration opening degree investigation process, the opening degree of the valve body 17 is changed within a predetermined range in order to find the minimum vibration opening degree. As this determined range, a range (FO to SO) in which the boost pressure does not rise unacceptably due to the change in the opening of the waste gate valve 14 within the same range is employed. For this reason, when the opening degree of the valve body 17 is changed within the predetermined range when searching for the minimum vibration opening degree, an increase beyond the allowable level of the supercharging pressure occurs, and the driver of the vehicle feels uncomfortable. Can be suppressed.

  (3) The characteristics of the vibration generated in the opening / closing direction of the valve body 17 by the action of the exhaust pulsation of the internal combustion engine 1 vary greatly with the aging of the valve 14 (the pin 16 and the valve body 17). Even if the vibration characteristic changes as described above, the opening degree of the valve body 17 is adjusted to the minimum vibration opening degree searched for by the minimum vibration opening degree investigation process, regardless of the secular change of the waste gate valve 14. The vibration can be effectively suppressed.

  (4) The structure of the valve 14 is not changed, such as increasing the rigidity of the support structure of the valve body 17 with the intention of suppressing vibration in the opening / closing direction of the valve body 17 of the waste gate valve 14. In addition, there is no increase in weight or deterioration in controllability with the change of the structure.

In addition, the said embodiment can also be changed as follows, for example.
The change in the opening degree of the valve element 17 of the waste gate valve 14 in the predetermined range is not necessarily performed from the fully opened opening degree FO to the opening degree SO, but from the opening degree SO to the fully opened opening degree FO. It is also possible to do this.

  In the minimum vibration opening degree investigation process, the amount of fluctuation in the opening degree of the valve body 17 of the waste gate valve 14 (the magnitude of vibration in the opening / closing direction of the valve body 17) is estimated based on the acceleration of the opening change of the valve body 17 Therefore, when the opening degree of the valve body 17 is changed within a predetermined range, it is not always necessary to change it stepwise, and it is also possible to change it linearly.

  In this case, if the rate of change when the opening degree of the valve element 17 is linearly changed as described above is “V”, the change is caused by the vibration in the opening / closing direction of the valve element 17 due to the influence of exhaust pulsation during the change. Acceleration / deceleration occurs in the opening change of the valve body 17. The acceleration of the change in the opening degree of the valve body 17 at this time includes the influence of the change speed V. Therefore, if the influence of the change speed V is removed from the acceleration obtained based on the detection value of the stroke sensor 28 during the change of the opening degree at the change speed V, the acceleration after the removal of the influence is a valve caused by exhaust pulsation. The value corresponds to the magnitude of vibration in the opening / closing direction of the body 17.

  Therefore, when the opening degree of the valve element 17 is changed within the predetermined range, the fluctuation amount (valve for each different opening degree in the changing process of the opening degree is based on the acceleration from which the influence of the changing speed V is removed. The magnitude of vibration in the opening / closing direction of the body 17 can be obtained.

  DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Combustion chamber, 3 ... Intake passage, 4 ... Turbocharger, 4a ... Compressor wheel, 4b ... Turbine wheel, 6 ... Throttle valve, 7 ... Fuel injection valve, 8 ... Piston, 9 ... Exhaust passage, DESCRIPTION OF SYMBOLS 10 ... Crankshaft, 13 ... Bypass passage, 14 ... Waste gate valve, 15 ... Accelerator pedal, 16 ... Pin, 17 ... Valve body, 18 ... Rod, 19 ... Actuator, 21 ... Electronic control unit, 22 ... Accelerator position sensor, 23 ... Throttle position sensor, 24 ... Supercharging pressure sensor, 25 ... Crank position sensor, 26 ... Intake air temperature sensor, 27 ... Atmospheric pressure sensor, 28 ... Stroke sensor.

Claims (1)

A waste gate valve provided in a bypass passage connected to bypass the turbine wheel of the supercharger with respect to an exhaust passage of the internal combustion engine, a sensor for detecting an opening degree of the waste gate valve, and the waste gate valve A controller for controlling the opening degree of the valve body based on the opening degree command value, and a waste gate valve control device comprising:
The control unit is configured such that the valve body is within a predetermined range when a variation amount of the opening degree of the valve body obtained using the sensor is equal to or greater than a determination value under a condition that the opening degree command value is constant The amount of fluctuation is obtained for each different degree of opening in the changing process, and the degree of opening of the valve body is controlled to the degree of opening when the amount of fluctuation is a minimum value. The waste gate valve control device, wherein the command value is adjusted to a value corresponding to the opening degree.