JP6079513B2 - Waste gate valve controller - Google Patents

Description

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

  The waste gate valve of Patent Document 1 has a valve and an arm. A clearance is formed between the valve and the arm. The position of the valve is switched between a closed position that closes the bypass passage and an open position that opens the bypass passage.

JP 2013-19337 A

  When foreign matter such as deposits enters the clearance between the valve and the arm, a part of the seal surface of the valve may not contact the valve seat. For this reason, there exists a possibility that the sealing performance of the bypass channel by a waste gate valve may fall.

  An object of the present invention is to provide a control device for a waste gate valve that can remove foreign substances adhering to the waste gate valve.

[1] A control device for the waste gate valve includes a main body and a pin protruding from the main body , and closes a bypass passage that bypasses a portion where the turbine wheel is disposed by contacting the valve seat, and A valve that is switched to an open position that opens when the bypass passage is separated from the valve seat, and an insertion hole and a pin inserted into the insertion hole with a clearance between the insertion hole and the pin. an arm for supporting the valve, a control device of the waste gate valve having an actuator, a switch between said closed position and the open position the position of the valve by moving the arm, the valve Switch the valve position from the open position to the closed position when sealing performance is degraded When the valve travel speed is higher than when the sealing performance is not deteriorated, or when the accumulated period of the amount of foreign matter contained in the exhaust gas is equal to or greater than a predetermined amount Then, an abnormal time response control is performed in which the moving speed of the valve is made higher than when the cumulative period is less than the predetermined period.

  In the waste gate valve control device, the moving speed of the valve is increased in the emergency response control. For this reason, the impact when a valve collides with a valve seat becomes large. For this reason, the foreign matter adhering to the waste gate valve is easily removed.

  [2] The control device of the waste gate valve includes a closed position in which a bypass passage that bypasses a portion where the turbine wheel is disposed is closed by contacting the valve seat, and the bypass passage is separated from the valve seat. Control of a wastegate valve having a valve that is switched to an open position to be opened, an arm that supports the valve, and an actuator that switches the position of the valve between the closed position and the open position by moving the arm When the sealing performance of the valve is lowered, the control for an abnormal time is performed to lower the output of the actuator for maintaining the valve in the closed position than when the sealing performance is not lowered. Or when the cumulative amount of the foreign matter contained in the exhaust gas is greater than or equal to the predetermined amount, The output of the actuator to maintain the valve in the closed position, performs abnormality response control to lower than when the accumulated time is less than the predetermined period.

  The exhaust applies a force in the direction of separating the valve from the valve seat. This force varies due to exhaust pulsation. The control device for the waste gate valve reduces the output of the actuator in the control in response to an abnormality. For this reason, the valve is easily separated from the valve seat. When the force applied from the arm to the valve is smaller than the force acting on the valve from the exhaust on the turbine side, the valve contacts the valve seat. For this reason, the valve repeatedly collides with the valve seat with the exhaust pulsation. When the valve and the valve seat collide, foreign matter adhering to the waste gate valve is easily removed.

The schematic diagram of the internal combustion engine of 1st Embodiment. The front view of the waste gate valve of 1st Embodiment. Sectional drawing of the D3-D3 line | wire of FIG. Sectional drawing which shows the alignment function of the waste gate valve of 1st Embodiment. (A) (b) The operation | movement figure of the waste gate valve in the control at the time of abnormality of 2nd Embodiment.

(First embodiment)
The configuration of the internal combustion engine 1 will be described with reference to FIG.
The internal combustion engine 1 includes an intake passage 10, an exhaust passage 20, a turbocharger 30, a waste gate valve 40, a drive mechanism 50, a control device 60, and a supercharging pressure sensor 70.

The turbocharger 30 has a turbine 31, a compressor 34, and a shaft 37.
The turbine 31 has a turbine housing 32 and a turbine wheel 33. The turbine wheel 33 is disposed inside the turbine housing 32. In the turbine housing 32, a cooling passage 32A and a valve seat 32B are formed. Cooling water circulates inside the cooling passage 32A.

  The compressor 34 has a compressor housing 35 and a compressor impeller 36. The compressor impeller 36 is disposed inside the compressor housing 35.

  The shaft 37 connects the turbine wheel 33 and the compressor impeller 36. When the turbine wheel 33 rotates due to exhaust, the compressor impeller 36 rotates integrally with the turbine wheel 33 so that the intake air in the intake passage 10 is supercharged.

  The exhaust passage 20 has a turbine passage 21 and a bypass passage 22. The turbine passage 21 is formed in the turbine housing 32. The bypass passage 22 bypasses a portion of the turbine passage 21 where the turbine wheel 33 is disposed.

The configuration of the waste gate valve 40 will be described with reference to FIGS.
As shown in FIG. 2, the waste gate valve 40 includes a valve 41, an arm 44, and a washer 45. The waste gate valve 40 is located downstream of the connection portion 22A between the bypass passage 22 and the upstream portion of the turbine passage 21, and closes the connection portion 22A from the downstream side of the bypass passage 22.

  The valve 41 has a main body 42 and a pin 43. As shown in FIG. 1, the position of the valve 41 is a closed position (solid line in the figure) that closes the bypass passage 22 by contacting the valve seat 32B, and opens the bypass passage 22 away from the valve seat 32B. It is switched between the open position (two-dot chain line in the figure). The open position includes a range from a position where the valve 41 does not contact the valve seat 32B and close to the valve seat 32B to a position where the valve 41 is farthest from the valve seat 32B.

  As shown in FIG. 3, the main body 42 has a disk shape. An outer peripheral portion of the main body 42 on the valve seat 32B side is formed as a seal surface 42A that comes into contact with the valve seat 32B. The pin 43 protrudes from the main body 42. The pin 43 is inserted into the insertion hole 44 </ b> A of the arm 44 and the insertion hole 45 </ b> A of the washer 45.

  As shown in FIG. 2, the arm 44 has an insertion hole 44A and a rotation shaft portion 44B. The arm 44 has an L shape. The insertion hole 44 </ b> A is formed at one end of the arm 44. The rotating shaft portion 44 </ b> B is formed as the other end of the arm 44.

  As shown in FIG. 3, the washer 45 has an insertion hole 45A. The arm 44 is sandwiched between the washer 45 and the main body 42. The arm 44 is prevented from coming off from the pin 43 by a washer 45.

  A clearance CLA is formed between the pin 43 and the insertion hole 44A. A clearance CLB is formed between the washer 45 and the arm 44. For this reason, the pin 43 can be inclined with respect to the arm 44.

  As shown in FIG. 1, the drive mechanism 50 includes a motor 51, a worm gear 52, a worm wheel 53, a crank arm 54, a drive rod 55, and a link mechanism 56. The drive mechanism 50 rotates the rotating shaft portion 44B of the waste gate valve 40. The motor 51 corresponds to an “actuator”.

  The output shaft 51 </ b> A of the motor 51 is connected to the worm gear 52. The worm gear 52 is meshed with the worm wheel 53. A rotating shaft 53 </ b> A that rotates integrally with the worm wheel 53 is attached to the worm wheel 53. The rotating shaft 53A is connected to one end of the crank arm 54. The other end of the crank arm 54 is connected to the drive rod 55. The drive rod 55 is connected to the link mechanism 56. The link mechanism 56 is connected to the rotating shaft portion 44B.

  The crank arm 54 swings around one end by the rotation of the rotating shaft 53A. The swing of the crank arm 54 moves the drive rod 55 connected to the other end of the crank arm 54 in the linear direction. The link mechanism 56 is tilted with the movement of the drive rod 55 in the linear direction, and rotates the rotation shaft portion 44B.

  When the motor 51 rotates in one direction, it applies a force in a direction away from the valve seat 32 </ b> B to the valve 41 via the arm 44. When the motor 51 rotates in the other direction, it applies a force in a direction approaching the valve seat 32 </ b> B to the valve 41 via the arm 44. The magnitude of the force applied from the motor 51 to the valve 41, that is, the output of the motor 51 varies depending on the current value supplied to the motor 51.

  The supercharging pressure sensor 70 is located downstream of the compressor 34 in the intake passage 10. The supercharging pressure sensor 70 outputs a signal corresponding to the pressure of the air supply (hereinafter “supercharging pressure BX”) to the control device 60. The control device 60 executes various controls according to the supercharging pressure BX and the engine operating state.

The valve opening change control executed by the control device 60 will be described.
The control device 60 switches the position of the valve 41 of the waste gate valve 40 between the closed position and the open position according to the engine operating state and the like. Specifically, the control device 60 changes the current value supplied to the motor 51 by controlling the duty ratio of the current supplied to the motor 51, and changes the output of the motor 51.

  The control device 60 stores in advance a closing movement current AC and an opening movement current AD as current values to be supplied to the motor 51 when the position of the valve 41 is changed. The closing movement current AC is previously determined based on experiments or the like as a current value for switching the position of the valve 41 from the open position to the closed position. The open movement current AD is determined in advance based on experiments or the like as a current value for switching the position of the valve 41 from the closed position to the open position. Note that the closing movement current AC and the opening movement current AD have different positive and negative currents.

The valve opening maintenance control executed by the control device 60 will be described.
The control device 60 maintains the position of the valve 41 at the open position or the closed position according to the engine operating state or the like. Due to the exhaust pulsation, a force is applied to the valve 41 in a direction away from the valve seat 32B. For this reason, the control device 60 supplies the opening maintaining current AK to the motor 51 when maintaining the position of the valve 41.

  The control device 60 uses, as the opening maintaining current AK, a current value for maintaining the position of the valve 41 at a predetermined position in the open position, and a current value for maintaining the position of the valve 41 in the closed position ( Hereinafter, “closing maintenance current AKC”) is stored in advance. Note that the closing maintenance current AKC is determined in advance by experiments or the like as a current value that can maintain the position of the valve 41 in the closing position when the exhaust pressure in the turbine passage 21 becomes maximum. For this reason, when the closing maintenance current AKC is supplied to the motor 51, the position of the valve 41 is maintained at the closing position even when exhaust pulsation occurs.

The abnormality response control executed by the control device 60 will be described.
The control device 60 determines that the supercharging pressure BX when the engine operating state is constant and the closing maintenance current AKC is supplied to the motor 51 is less than the determination pressure BA, that is, the sealing performance of the valve 41. Increases the closed travel current AC.

Next, the control device 60 supplies the open movement current AD to the motor 51 over a predetermined period, and switches the position of the valve 41 from the closed position to a predetermined open position.
Next, when the predetermined period has elapsed, that is, when it is estimated that the position of the valve 41 has changed from the closed position to the predetermined open position, the control device 60 is more than when the supercharging pressure BX is equal to or higher than the determination pressure BA. Also, the increased open movement current AD is supplied to the motor 51 over a predetermined period, and the position of the valve 41 is switched from the open position to the closed position.

  Next, the control device 60 estimates that when a predetermined period has elapsed since the opening movement current AD was supplied to the motor 51, that is, when the position of the valve 41 has been changed from the predetermined open position to the closed position. The correction of the closing movement current AC is finished, and the control for abnormal times is finished.

The operation of the control device 60 will be described with reference to FIG.
For example, the turbine housing 32 may be deformed by heat, and the valve seat 32B may be inclined. In this case, an alignment function in which the valve 41 is inclined with respect to the arm 44 according to the deformation of the turbine housing 32 acts, so that the entire seal surface 42A of the valve 41 contacts the valve seat 32B. For this reason, the sealing performance of the waste gate valve 40 is maintained.

  On the other hand, when a foreign object is caught in the clearance between the valve 41 and the arm 44, the valve 41 is difficult to tilt with respect to the arm 44. For this reason, when the valve 41 is in the closed position, a part of the seal surface 42A is separated from the valve seat 32B, and the sealing performance of the valve 41 may be deteriorated. When the sealing performance of the valve 41 is lowered, the exhaust gas flows out from the gap between the valve 41 and the valve seat 32B into the bypass passage 22. In addition, as a foreign material, the oxide of components, such as a deposit and the valve 41, is mentioned.

When the sealing performance of the valve 41 is lowered, the supercharging pressure BX when the engine operating state is constant and the closing maintenance current AKC is supplied to the motor 51 is less than the determination pressure BA.
When the supercharging pressure BX is lower than the determination pressure BA, that is, when it is estimated that the sealing performance of the valve 41 is deteriorated, the control device 60 increases the open movement current AD. For this reason, the moving speed of the valve 41 when the position of the valve 41 is switched from the open position to the closed position increases. For this reason, the impact generated between the valve 41 and the insertion hole 44A when the valve 41 and the valve seat 32B collide with each other is increased.

  The turbine housing 32 is cooled by the cooling water in the cooling passage 32A. The waste gate valve 40 is located in the vicinity of the turbine housing 32. For this reason, the temperature of the waste gate valve 40 tends to be lowered due to the cooling of the turbine housing 32. For this reason, deposits are likely to occur in the clearance between the pin 43 and the insertion hole 44A. For this reason, the sealing performance of the valve 41 tends to deteriorate. The control device 60 executes an emergency response control. For this reason, both the cooling of the turbine housing 32 and the suppression of a decrease in the sealing performance of the valve 41 can be achieved.

The control device 60 has the following effects.
(1) The control device 60 executes an abnormality response control that increases the moving speed of the valve 41. For this reason, the foreign matter adhering to the waste gate valve 40 is easily removed. For this reason, it can suppress that the sealing performance of the valve 41 falls.

(Second Embodiment)
The internal combustion engine 1 of 2nd Embodiment has a different structure in the following part compared with the internal combustion engine 1 of 1st Embodiment, and has the same structure in another part. That is, the internal combustion engine 1 according to the second embodiment changes the closing maintenance current AKC in the control in response to an abnormality. In the description of the internal combustion engine 1 of the second embodiment, the same reference numerals as those of the internal combustion engine 1 of the first embodiment are attached to the configurations common to the internal combustion engine 1 of the first embodiment.

With reference to FIG. 1, the abnormality handling control executed by the control device 60 will be described.
When it is determined that all of the following (Condition A) to (Condition C) are satisfied, the control device 60 decreases the closing maintenance current AKC. When it is determined that at least one of (Condition A) to (Condition C) is not satisfied, the control device 60 ends the correction for reducing the closed moving current AC, and ends the abnormality handling control.
(Condition A) The supercharging pressure BX when the engine operating state is constant and the closing maintenance current AKC is supplied to the motor 51 is less than the determination pressure BA.
(Condition B) The closing maintenance current AKC is supplied to the motor 51.
(Condition C) The vehicle is accelerating.

The operation of the control device 60 will be described with reference to FIG.
The control device 60 decreases the closing maintenance current AKC when the supercharging pressure BX is less than the determination pressure BA. For this reason, the output of the motor 51 falls. For this reason, the valve 41 is easily separated from the valve seat 32B.

  As shown in FIG. 5A, when the pressure of the exhaust gas in the turbine passage 21 exceeds the force of the motor 51 pressing the valve 41 against the valve seat 32B, the valve 41 is in contact with the valve seat 32B. . As shown in FIG. 5B, when the pressure in the turbine passage 21 falls below the force of the motor 51 pressing the valve 41 against the valve seat 32B due to exhaust pulsation, the valve 41 moves away from the valve seat 32B.

  The valve 41 repeats the state of FIG. 5A and the state of FIG. 5B in accordance with the pressure variation in the turbine passage 21. That is, the valve 41 and the valve seat 32B repeatedly collide. For this reason, the impact by the collision with the valve 41 and the valve seat 32B repeatedly arises.

  The controller 60 reduces the closing maintenance current AKC when the vehicle is accelerated. When the vehicle is accelerating, the exhaust temperature is low. For this reason, the temperature of the valve 41 and the valve seat 32B is also low. The valve 41 and the valve seat 32B are not easily deformed when the temperature of the exhaust gas is low. For this reason, it is suppressed that a deformation | transformation arises in the valve 41 and the valve seat 32B by the impact added to the valve 41 and the valve seat 32B by control at the time of abnormality.

  Further, when the vehicle is accelerated, the vibration of the vehicle body is large. For this reason, it is difficult for the driver to feel the influence on the vehicle body due to the fluctuation of the supercharging pressure BX accompanying the separation of the valve 41 from the valve seat 32B. For this reason, it is possible to suppress the driver from feeling uncomfortable.

The control device 60 has the following effects.
(2) The control device 60 executes an abnormality handling control for reducing the closing maintenance current AKC. For this reason, the foreign matter adhering to the waste gate valve 40 is easily removed. For this reason, it can suppress that the sealing performance of the valve 41 falls.

(Other embodiments)
The control device for the waste gate valve can take the following modifications.
The control device 60 according to the modified example of the first embodiment is closed when the following (Condition XA), (Condition XB), (Condition XC), or (Condition XD) is satisfied in the control at the time of abnormality. Increase the current AC. In addition, when (Condition XA), (Condition XB), or (Condition XC) is satisfied, it corresponds to “when the sealing performance of the valve 41 is lowered”. When (Condition XD) is satisfied, it corresponds to “when the cumulative period of the period in which the amount of foreign matter contained in the exhaust gas is equal to or greater than a predetermined amount becomes equal to or greater than a predetermined period”.

(Condition XA) The engine operating state is constant, and the rotation speed of the turbine 31 when the closing maintenance current AKC is supplied to the motor 51 is less than the determination speed.
(Condition XB) When the engine operating state is constant and the closing maintenance current AKC is supplied to the motor 51, the actual position of the valve 41 is in the open position.

(Condition XC) When the engine operating state is constant, the closing maintenance current AKC is supplied to the motor 51, and the exhaust gas temperature is lower than a predetermined temperature.
(Condition XD) When the engine operating state is constant, the closing maintenance current AKC is supplied to the motor 51, and the cumulative period during which the exhaust gas temperature is lower than the predetermined temperature is equal to or greater than the predetermined period. Note that the period during which the exhaust gas temperature is lower than the predetermined temperature corresponds to a “period in which the amount of foreign matter contained in the exhaust gas is equal to or greater than a predetermined amount”.

  When the above (Condition XB) is adopted in the control at the time of abnormality, a sensor for detecting the rotation angle of the motor 51 or the rotating shaft portion 44B or a sensor for detecting the amount of movement of the drive rod 55 is added to the valve 41. It is preferable to estimate the actual position.

When the above (Condition XC) or (Condition XD) is adopted in the control at the time of abnormality, it is preferable to detect the exhaust temperature by the temperature sensor at the catalyst inlet portion in the exhaust passage 20.
When the above (Condition XD) is adopted in the emergency response control, it becomes easy to remove foreign matter in the waste gate valve 40. Further, before the influence of foreign matter between the valve 41 and the arm 44 on the supercharging pressure BX increases, that is, before the sealing performance of the valve 41 decreases, the deposit between the valve 41 and the arm 44 increases. This can be suppressed.

  The control device 60 according to the modified example of the first embodiment is a case where the engine operating state is constant and the position of the valve 41 is maintained at the open position in the control for abnormality, and the exhaust temperature is When the cumulative period of the period lower than the predetermined temperature becomes equal to or longer than the predetermined period, the closed moving current AC is increased. Next, the control device 60 supplies a closing movement current AC to the motor 51 to move the position of the valve 41 from the open position to the closed position. When it is estimated that the position of the valve 41 has moved to the closed position, the control device 60 ends the correction of the closed moving current AC and controls the position of the valve 41 based on the engine operating state and the like.

  The control device 60 according to the modification of the first embodiment increases the closing movement current AC in the abnormality response control, stores the increased closing movement current AC, and ends the abnormality response control. The control device 60 supplies the motor 51 with a closing movement current AC that is increased when the position of the valve 41 is moved from the opening position to the closing position based on the engine operating state or the like.

  -In addition to (Condition B) and (Condition C) of the second embodiment, the control device 60 of the modified example of the second embodiment includes (Condition XA), (Condition XB), (Condition XC), or When (Condition XD) is satisfied, the closing maintenance current AKC is decreased.

  -The internal combustion engine 1 of the modification of each embodiment has an actuator comprised by a negative pressure source, a solenoid valve, and a negative pressure chamber. The negative pressure chamber is connected to the drive rod 55. As the negative pressure source, for example, a vacuum pump driven by the internal combustion engine 1 can be used. When the electromagnetic solenoid of this solenoid valve is in a non-excited state, the negative pressure chamber is in a non-communication state with the negative pressure source and becomes atmospheric pressure. When the solenoid of the solenoid valve is in the excited state, the negative pressure chamber is in communication with the negative pressure source and negative pressure is generated. The drive rod 55 moves in a linear direction according to the pressure in the negative pressure chamber. The control device 60 of this modification adjusts the negative pressure of the negative pressure chamber by controlling the duty ratio of the current supplied to the electromagnetic solenoid of the electromagnetic valve.

  DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 10 ... Intake passage, 20 ... Exhaust passage, 21 ... Turbine passage, 22 ... Bypass passage, 22A ... Connection part, 30 ... Turbocharger, 31 ... Turbine, 32 ... Turbine housing, 32A ... Cooling passage, 32B ... Valve seat, 33 ... Turbine wheel, 34 ... Compressor, 35 ... Compressor housing, 36 ... Compressor impeller, 37 ... Shaft, 40 ... Wastegate valve, 41 ... Valve, 42 ... Main body, 42A ... Seal surface, 43 ... Pin, 44 ... arm, 44A ... insertion hole, 44B ... rotary shaft, 45 ... washer, 45A ... insertion hole, 50 ... drive mechanism, 51 ... motor, 51A ... output shaft, 52 ... worm gear, 53 ... worm wheel, 53A ... rotation Shaft 54 ... Crank arm 55 ... Drive rod 56 ... Link mechanism 60 ... Control device 70 ... Over Pressure sensor.

Claims (2)

A closed position having a main body and a pin protruding from the main body and closing a bypass passage that bypasses a portion where the turbine wheel is disposed by contacting the valve seat; and by separating the bypass passage from the valve seat moving a valve is switched to an open position for opening, the arm supporting the said valve in a state in which the pins have a clearance is inserted into the insertion hole between the insertion hole and the pin and having an insertion hole, said arm a control device of the waste gate valve having an actuator for switching between the closed position and the open position the position of the valve by,
When the sealing performance of the valve is deteriorated, it is possible to cope with an abnormality in which the moving speed of the valve when switching the valve position from the open position to the closed position is higher than when the sealing performance is not deteriorated. control,
Alternatively, when the cumulative period of the period in which the amount of foreign matter contained in the exhaust gas is greater than or equal to a predetermined period is greater than or equal to the predetermined period, control for handling an abnormal time is performed to increase the moving speed of the valve than when the cumulative period is less than the predetermined period Perform Wastegate valve control device. A valve that is switched to a closed position that closes a bypass passage that bypasses a portion where the turbine wheel is disposed by contacting the valve seat, and an open position that opens by leaving the bypass passage away from the valve seat; A wastegate valve control device having a supporting arm and an actuator for switching the position of the valve between the closed position and the open position by moving the arm;
When the sealing performance of the valve is lowered, control for an abnormal time to lower the output of the actuator for maintaining the valve in the closed position than when the sealing performance is not lowered,
Alternatively, when the cumulative period of the period in which the amount of foreign matter contained in the exhaust is greater than or equal to a predetermined period is greater than or equal to the predetermined period, the output of the actuator for maintaining the valve in the closed position is less than the predetermined period. Waste gate valve control device that performs control in response to an abnormal condition that is lower than normal.