JP2011169208A - Control device and controlling method of variable turbo supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device and controlling method for a variable turbo supercharger capable of controlling a nozzle part quickly into the full closed condition while breakage of the nozzle part is suppressed. <P>SOLUTION: A controller outputs the control amount of the hydraulic servo valve using a control target position smaller than the target value complying with the current position of the exhaust gas introducing wall 12 so that the exhaust gas introducing wall 12 may not contact with the exhaust gas introducing wall 13 even in case the control amount of the hydraulic servo valve commits an overshoot. This allows controlling the position of the exhaust gas introducing wall 12 quickly into the full closed position 100[%], and makes it possible to control the nozzle part 11 into the full closed position quickly. It is also possible to prevent the nozzle part 11 from breaking owing to the occurrence that the exhaust gas introducing wall 12 collides with the exhaust gas introducing wall 13 strongly. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a control device for a variable turbocharger and a control method therefor.

  Conventionally, there is known a variable turbocharger capable of adjusting an opening area of a nozzle portion that supplies exhaust gas to an exhaust turbine. According to this variable turbocharger, in a low engine speed range where the flow rate of exhaust gas is low, the exhaust gas flow supplied to the exhaust turbine is increased by reducing the opening area of the nozzle portion, thereby reducing the exhaust gas. The supercharging capability of the air supply compressor connected to the turbine can be increased.

  In such a variable turbocharger, the opening area of the nozzle portion is such that one of the exhaust introduction walls that constitute the nozzle portion is adjacent to the other exhaust introduction wall. It is adjusted by separating them. Also, one exhaust introduction wall is moved closer to / away from the other exhaust introduction wall by reciprocating the hydraulic piston by controlling the opening of the hydraulic servo valve.

  For this reason, when the nozzle part is fully closed by bringing one exhaust introduction wall into contact with the other exhaust introduction wall, the control amount of the hydraulic servo valve overshoots the target value, There is a possibility that the exhaust introduction wall collides with the other exhaust introduction wall with a large force, and the nozzle portion is damaged.

  From such a background, when performing feedback control of the opening degree of the hydraulic servo valve, by limiting the deviation between the control amount of the hydraulic servo valve and the target value to a predetermined level range, it collides with the other exhaust introduction wall. There has been proposed a control apparatus for a hydraulic servo valve that brings one exhaust introduction wall close to a fully closed position at a constant speed without any problem (see Patent Document 1).

JP 2007-303583 A

  By the way, a diesel engine discharges particulate matter (hereinafter referred to as PM) not only during normal operation but also during starting, rapid acceleration, high load, and the like. This PM is a pollution-causing substance including soot generated by incomplete combustion of fuel and organic soluble components that are unburned components of fuel and lubricating oil. For this reason, a vehicle using a diesel engine as a drive source is equipped with a filter device called a diesel particulate filter (hereinafter referred to as DPF) in order to reduce the amount of PM contained in the exhaust gas.

  In a vehicle on which this DPF is mounted, a regeneration process for burning PM accumulated in the DPF is executed. This regeneration process includes a natural regeneration process in which PM spontaneously burns by high-temperature exhaust gas discharged when the load of the diesel engine is high, and a dosing fuel is supplied to the DPF when the load and rotation speed of the diesel engine are low. And a forced regeneration process for forcibly burning PM. By appropriately executing such regeneration processing, it is possible to suppress the occurrence of problems such as increased efficiency of exhaust gas due to surging and exhaust resistance deterioration due to excessive PM accumulation in the DPF. it can.

  When executing the forced regeneration process of the DPF, it is required that the temperature of the exhaust gas supplied to the DPF is equal to or higher than a predetermined temperature. The reason is that when the temperature of the exhaust gas supplied to the DPF is lower than a predetermined temperature, the dosing fuel supplied to the DPF is incompletely combusted, causing soot to be discharged. For this reason, in the case where the DPF forced regeneration process is executed in a vehicle equipped with the variable turbocharger, and the temperature of the exhaust gas supplied to the DPF is lower than a predetermined temperature, the nozzle portion is The temperature of the exhaust gas supplied to the DPF needs to be raised by quickly controlling to the fully closed state and supplying the hot exhaust gas to the DPF via a bypass that bypasses the variable turbocharger.

  In particular, when the vehicle is a construction machine, working machines such as a boom, an arm, a bucket, and a blade are operated and the engine load fluctuates, so that the temperature of the exhaust gas supplied to the DPF becomes less than a predetermined temperature. Therefore, when the forced regeneration process of the DPF is executed when the construction machine on which the variable turbocharger is mounted is operating, the nozzle part is quickly controlled to be fully closed, and the variable turbocharger is It is necessary to raise the temperature of the exhaust gas supplied to the DPF by supplying the high-temperature exhaust gas to the DPF via a bypass route that bypasses.

  However, as already described, in the control apparatus for the hydraulic servo valve described in Patent Document 1, one exhaust introduction wall constituting the nozzle portion is completely moved at a constant speed with no problem even if it collides with the other exhaust introduction wall. In order to approach the closed position, the nozzle portion cannot be quickly controlled to the fully closed state. For this reason, according to the control apparatus for the hydraulic servo valve described in Patent Document 1, it is possible to suppress the nozzle portion from being damaged when the nozzle portion is controlled to the fully closed state in order to execute the forced regeneration processing of the DPF. There is a risk of soot being discharged due to incomplete combustion of dosing fuel.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a variable turbocharger capable of quickly controlling the exhaust introduction path to a fully closed state while suppressing damage to the exhaust introduction path. And a control method thereof.

  In order to solve the above-described problems and achieve the object, a control device for a variable turbocharger according to the present invention operates exhaust pressure provided in an exhaust introduction path of a variable turbocharger by operating a hydraulic servo valve. In a control device for a variable turbocharger that controls an opening area of an exhaust introduction passage by moving an introduction member, a detector that detects a current position of the exhaust introduction member, and an exhaust introduction member detected by the detector A controller that adjusts the control amount of the hydraulic servo valve by feeding back the current position, and when the controller closes the exhaust introduction path, the position of the exhaust introduction member even if the control amount of the hydraulic servo valve overshoots The control target position is smaller than the target value corresponding to the current position of the exhaust introduction member so that the oil does not reach the fully closed position that closes the exhaust introduction path. And it outputs the control amount of the servo valve.

  In order to solve the above-described problems and achieve the object, a control method for a variable turbocharger according to the present invention includes an exhaust provided in an exhaust introduction path of a variable turbocharger by operating a hydraulic servo valve. In the variable turbocharger control method for controlling the opening area of the exhaust introduction path by moving the introduction member, a detection step for detecting the current position of the exhaust introduction member, and a detection step of the exhaust introduction member detected in the detection step An adjustment step of adjusting the control amount of the hydraulic servo valve by feeding back the current position, and the adjustment step includes the exhaust introduction member even when the control amount of the hydraulic servo valve overshoots when the exhaust introduction path is closed The control target position is smaller than the target value corresponding to the current position of the exhaust introduction member so that the position of the exhaust does not become the fully closed position that closes the exhaust introduction path. Comprising the step of outputting the control amount of the hydraulic servo valve with.

  According to the control device and the control method for a variable turbocharger according to the present invention, the exhaust introduction member is provided with the exhaust introduction member even if the control amount of the hydraulic servo valve that changes according to the position overshoots from the target value. Is controlled to the fully closed position at a speed that does not become the fully closed position for closing the exhaust introduction path, so that the exhaust introduction path can be quickly controlled to be fully closed while preventing the exhaust introduction path from being damaged. it can.

FIG. 1 is a cross-sectional view showing a configuration of a variable turbocharger that is an embodiment of the present invention. FIG. 2 is a diagram showing the configuration of the slide mechanism, and is a view taken in the direction of arrow II in FIG. FIG. 3 is a cross-sectional view illustrating a configuration of a main part of the slide mechanism. FIG. 4 is a perspective view showing a configuration of a connecting portion between the slide mechanism and the hydraulic servo drive device. FIG. 5 is a cross-sectional view showing the configuration of the hydraulic servo drive device. FIG. 6 is a block diagram showing a configuration of a control device of the hydraulic servo drive device. FIG. 7 is a functional block diagram showing the internal configuration of the controller shown in FIG. FIG. 8 is a functional block diagram showing an internal configuration of the target position restriction unit shown in FIG. FIG. 9 is a diagram illustrating an example of the target position table. FIG. 10 is a graph of the target position table shown in FIG. FIG. 11 is a view for explaining a method of representing the position of the exhaust introduction wall in the present embodiment. FIG. 12 is a diagram showing a modification of the target position table shown in FIG. FIG. 13 is a graph of the target position table shown in FIG. FIG. 14 shows the case where the target position is set to (a) 100 [%], (b) 80 [%], and (c) 70 [%] when the current position of the exhaust introduction wall is the fully open position 0 [%]. It is a simulation waveform diagram which shows the change of the position of the exhaust introduction wall in connection with time in FIG. FIG. 15 shows the state of the exhaust introduction wall over time when the target position is set to (a) 100 [%] and (b) 82 [%] when the current position of the exhaust introduction wall is at position 40 [%]. It is a simulation waveform diagram which shows the change of a position. FIG. 16 shows the state of the exhaust introduction wall over time when the target position is set to (a) 100 [%] and (b) 88 [%] when the current position of the exhaust introduction wall is at position 60 [%]. It is a simulation waveform diagram which shows the change of a position. FIG. 17 is a flowchart showing the flow of the fully closed control process by the controller. FIG. 18 is a graph showing the time lapse between the current position of the exhaust introduction wall and the target position when the nozzle portion is quickly controlled to the fully closed state when the conventional turbocharger control method and the control method of the variable turbocharger of the present embodiment are used. It is a figure which shows a change. FIG. 19 shows (a) a current command value for an electromagnetic proportional valve and (a) when there is no need to quickly control the nozzle portion to a fully closed state when the variable turbocharger control method of this embodiment is used. b) It is a figure which shows a time-dependent change with the position of an exhaust introduction wall.

  Hereinafter, the configuration and operation of a variable turbocharger according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the variable turbocharger is mounted on a construction machine that uses a diesel engine as a drive source, and the construction machine includes an actuator such as a motor and a cylinder, and a work machine such as a steering mechanism. Shall be provided.

[Configuration of variable turbocharger]
First, with reference to FIG. 1, the structure of the variable turbocharger which is one Embodiment of this invention is demonstrated.

  FIG. 1 is a cross-sectional view showing a configuration of a variable turbocharger that is an embodiment of the present invention. As shown in FIG. 1, a variable turbocharger 1 according to an embodiment of the present invention includes a supply air compressor and an exhaust turbine on the left side and the right side of the drawing, respectively. It is provided on the main body. Since the configuration on the air supply compressor side is already known at the time of filing of the present invention, detailed description thereof will be omitted below.

  A turbine wheel 3 is accommodated in the turbine housing 2 on the exhaust turbine side. A compressor impeller 5 is accommodated in the compressor housing 4 on the supply air compressor side. A shaft 6 is integrally provided on the turbine wheel 3, and a compressor impeller 5 is attached to the tip of the shaft 6. The shaft 6 is rotatably supported by the center housing 7.

  The turbine housing 2 is provided with a volute-shaped exhaust introduction path 10 for introducing exhaust gas from the diesel engine. A nozzle portion 11 is continuously provided in the exhaust introduction path 10 in the circumferential direction. The nozzle portion 11 is formed by a pair of exhaust introduction walls 12 and 13 that face each other.

  The exhaust gas ejected from the nozzle unit 11 rotates the turbine wheel 3 and is then exhausted from the exhaust outlet 14 and guided to a DPF (not shown). The rotation of the turbine wheel 3 is transmitted to the compressor impeller 5 through the shaft 6, and the supply air is compressed and supercharged by the rotation of the compressor impeller 5. A DPF (not shown) reduces the amount of PM contained in the exhaust gas, and then exhausts the exhaust gas to the outside air.

  The exhaust introduction wall 12 is formed by a side surface 16 of a movable ring 15 having a U-shaped cross section and an annular shape. The movable ring 15 is housed in an annular housing chamber 17 provided in the center housing 7. A plurality of nozzle vanes 18 are attached to the side surface 16 of the movable ring 15 at equal circumferential intervals. The plurality of nozzle vanes 18 protrude toward the other exhaust introduction wall 13 side.

  The exhaust introduction wall 13 is continuously provided with a recess 19 in the circumferential direction, and the tip side of each nozzle vane 18 is accommodated in the recess 19. In such a structure, the opening area of the nozzle portion 11 is adjusted by moving the movable ring 15 back and forth by a slide mechanism 20 described later to bring the exhaust introduction wall 12 close to / separate from the exhaust introduction wall 13. The nozzle portion 11 and the exhaust introduction wall 12 function as an exhaust introduction path and an exhaust introduction member according to the present invention, respectively.

[Configuration of slide mechanism]
Next, the configuration of the slide mechanism 20 will be described with reference to FIGS. FIG. 2 is a diagram showing the configuration of the slide mechanism 20, and is a view taken in the direction of arrow II in FIG. FIG. 3 is a cross-sectional view illustrating a configuration of a main part of the slide mechanism 20.

  As shown in FIGS. 2 and 3, the slide mechanism 20 includes a drive shaft 21 inserted through the lower side of the center housing 7. A pair of arms 22, 22 extending in an arc shape upward is fixed at a midway position of the drive shaft 21. A pin 23 protruding outward in the horizontal direction is attached to the distal end side of each arm 22, and a slider 24 is fitted into the pin 23. The slider 24 is slidably fitted in a sliding groove 26 on the base end side of a support rod 25 disposed in parallel to the shaft 6.

  The tip of the support rod 25 is joined to the back side of the movable ring 15. The drive shaft 21 is rotationally driven by a hydraulic servo drive device 30 via an arm 27 provided at an end thereof. In such a structure, as the drive shaft 21 rotates, the arm 22 swings along the axial direction of the shaft 6 and the support rod 25 moves. As the support rod 25 moves, the movable ring 15 moves, and the exhaust introduction wall 12 approaches / separates from the exhaust introduction wall 13.

[Configuration of hydraulic servo drive unit]
Next, the configuration of the hydraulic servo drive device 30 will be described with reference to FIGS.
FIG. 4 is a perspective view showing a configuration of a connecting portion between the slide mechanism 20 and the hydraulic servo drive device 30. FIG. 5 is a cross-sectional view showing the configuration of the hydraulic servo drive device 30.

  As shown in FIGS. 4 and 5, the hydraulic servo drive device 30 is configured to rotate the drive shaft 21 via the arm 27 by reciprocating the hydraulic piston 31 in the vertical direction. For this reason, a sliding groove 32 orthogonal to the axial direction is provided on the outer periphery of the hydraulic piston 31. The arm 27 is provided with a pin 28 that protrudes toward the sliding groove 32. A slider 29 is fitted into the pin 28, and the slider 29 is slidably fitted into the sliding groove 32. In such a configuration, the slider 29 moves up and down and slides along the sliding groove 32 as the hydraulic piston 31 moves up and down. The movement of the slider 29 and the rotation of the pin 28 allow the arc movement of the arm 27, the arm 27 rotates, and the drive shaft 21 rotates.

  The hydraulic servo drive device 30 includes a hydraulic piston 31, a housing 33, and a pilot spool 34, and is attached to the center housing 7 of the variable turbocharger 1 via an O-ring 70 that seals around an opening 33 </ b> A of the housing 33. ing. The housing 33 has an opening 33A in a part thereof and slidably accommodates the hydraulic piston 31. The pilot spool 34 is accommodated in a center hole 35 that penetrates the hydraulic piston 31 in the axial direction, and slides in the axial direction by the pilot pressure.

  The outer shape of the housing 33 is a prismatic shape, and a cylindrical cylinder space 36 penetrating in the vertical direction is provided inside the housing 33. A hydraulic piston 31 is accommodated in the cylinder space 36. The upper and lower ends of the cylinder space 36 are sealed by closing members 37 and 38 via O-rings 71 and 72. A connecting portion 39 between the drive shaft 21 and the hydraulic piston 31 is provided at a position corresponding to the opening 33A of the housing 33. Therefore, the size of the opening 33 </ b> A is set in consideration of the sliding amount of the hydraulic piston 31 and the slider 29.

  On the side surface opposite to the opening 33A of the housing 33, a pilot port 41 that supplies pilot pressure from an electromagnetic proportional valve 80 controlled by the controller 100, and a pump port 42 that supplies pressure oil from a booster pump (not shown). , And a drain port 43 for returning the pressure oil. The electromagnetic proportional valve 80 and a booster pump (not shown) are installed in the same diesel engine body on which the variable turbocharger 1 is mounted.

  In the cylinder space 36, a portion where the hydraulic piston 31 slides and an upper portion thereof are partitioned by a partition member 44. The partition member 44 abuts on a step portion provided on the inner peripheral surface of the cylinder space 36, and an O-ring 73 for sealing the space partitioned by the partition member 44 is provided in the vicinity of the contact portion. . The partition member 44 is provided with a cylindrical portion 45 that hangs downward. The cylindrical portion 45 enters the upper side of the center hole 35 of the hydraulic piston 31. An upper space partitioned by the partition member 44 is a pilot hydraulic chamber 46, and the pilot hydraulic chamber 46 and the pilot port 41 communicate with each other.

  The lower space partitioned by the partition member 44 is a first hydraulic chamber 47 formed between the partition member 44 and the upper end surface of the hydraulic piston 31. In other words, the pilot hydraulic chamber 46 is displaced in the axial direction with respect to the first hydraulic chamber 47, that is, upward in the present embodiment, and this arrangement prevents the hydraulic servo drive device 30 from increasing in diameter. Yes. A second hydraulic chamber 48 is formed between the lower end surface of the hydraulic piston 31 and the lower closing member 38.

  The hydraulic piston 31 is provided with a pressure oil passage 51 through which the center hole 35 and the pump port 42 of the housing 33 communicate with each other and pressure oil from the pump flows into the center hole 35. The outer peripheral side of the pressure oil passage 51 is open to a groove portion that is formed to face in the radial direction, and the groove portion has a predetermined vertical dimension, so that the pressure oil passage 51 and the pressure oil passage 51 are within the stroke of the hydraulic piston 31. The pump port 42 is always in communication.

  The hydraulic piston 31 is provided with a return oil passage 52 that connects the center hole 35 and the drain port 43 of the housing 33 to return the pressure oil in the center hole 35 to the tank. The outer periphery side of the return oil passage 52 opens into a groove formed on the outer periphery of the hydraulic piston 31, and the return oil passage 52 and the drain port 43 always communicate with each other within the stroke of the hydraulic piston 31. In this embodiment, the connecting portion 39 between the hydraulic piston 31 and the drive shaft 21 is provided at a position corresponding to the opposite side of the return oil passage 52, and is axially lower than the pressure oil passage 51. It is shifted to the side.

  The hydraulic piston 31 communicates with the first piston oil passage 53 that connects the center hole 35 and the upper first hydraulic chamber 47, and the second piston oil passage 54 that connects the center hole 35 and the lower second hydraulic chamber 48. Is provided. The opening portion of the first piston oil passage 53 on the center hole 35 side is positioned below the opening portion of the pressure oil passage 51, and the opening portion of the second piston oil passage 54 on the center hole 35 side is the pressure oil passage. It is located above the opening portion of 51. The first and second piston oil passages 53 and 54 are provided at positions that do not communicate with the pressure oil passage 51 and the return oil passage 52, respectively.

  The lower side of the center hole 35 is sealed by the contact member 55 being screwed to the hydraulic piston 31 via the O-ring 74. The hydraulic piston 31 comes into contact with the closing member 38 via the contact member 55, and the contacted position is the lowest position of the hydraulic piston 31. In the second hydraulic chamber 48, a coil spring 56 is disposed between the closing member 38 and the contact member 55 to assist the upward movement of the hydraulic piston 31. Thereby, even when the pressure oil in the pipe connected to the hydraulic servo drive device 30 is lost due to a failure of a booster pump (not shown) or the like, the opening degree of the nozzle portion 11 of the variable turbocharger 1 is increased by the spring force of the coil spring 56. It is designed to be kept fully open.

  The pilot spool 34 includes first and second spool lands 61 and 62 at a substantially central portion. A return oil passage 63 that opens downward is provided in the pilot spool 34. The upper groove portion of the first spool land 61 and the return oil passage 63 communicate with each other, and the lower groove portion of the second spool land 62 and the return oil passage 63 similarly communicate with each other. Further, since the lower side of the return oil passage 63 is open, the return oil passage 63, the return oil passage 52, and the drain port 43 communicate with each other.

  The pilot spool 34 can slide up and down in the center hole 35 of the hydraulic piston 31 through the cylindrical portion 45 of the partition member 44, and the upper end portion of the pilot spool 34 is screwed and held in a holding member 64 disposed in the pilot hydraulic chamber 46. Has been. In the pilot hydraulic chamber 46, the holding member 64 is urged upward by a coil bar spring 65. The pilot spool 34 moves downward by applying a pilot pressure against the urging force of the coil spring 65, and moves upward by the urging force of the coil spring 65 by reducing the pilot pressure oil.

  The moving member 81 is screwed and held by the holding member 64. The moving member 81 is arranged so that the closing member 37 can be inserted. The magnetic sensor 82 is provided in a housing 83 fixed to the closing member 37. The moving member 81 is arranged so as to be able to move in the housing 83. The magnetic sensor 82 is assumed to be a Hall IC capable of detecting magnetic force without contact, and a magnet 81 a is provided at a predetermined position in the axial longitudinal direction of the moving member 81. The magnetic sensor 82 functions as a detector that detects the current position of the exhaust introduction member according to the present invention.

  The magnitude of the magnetic force detected by the magnetic sensor 82 changes according to the movement of the moving member 81. Therefore, the position of the moving member 81 can be detected by converting the magnitude of the magnetic force detected by the magnetic sensor 82 into a position. The moving member 81 moves together with the pilot spool 34 via the holding member 64. Then, the hydraulic piston 31 moves following the movement of the pilot spool 34. For this reason, the position of the hydraulic piston 31, that is, the position of the exhaust introduction wall 12 can be detected by the magnetic force sensor 82.

[Operation of Hydraulic Servo Drive]
Next, the operation of the hydraulic servo drive device 30 will be described with reference to FIG. 5 again.

  FIG. 5 shows a state in which both the pilot spool 34 and the hydraulic piston 31 are in the lowest position by applying a pilot pressure exceeding the urging force of the coil spring 65. In this state, the lower end of the pilot spool 34 is in contact with the upper side of the contact member 55. Further, the lower end of the contact member 55 is in contact with the closing member 38. Further, at this position, the first spool land 61 on the upper side of the pilot spool 34 is shifted downward with respect to the upper opening of the second piston oil passage 54. Thus, the second piston oil passage 54 communicates with the return oil passage 52 via the return oil passage 63, and the pressure oil in the second hydraulic chamber 48 is drained. On the other hand, the second spool land 62 is shifted downward with respect to the lower opening of the first piston oil passage 53, and the pressure oil passage 51 and the first piston oil passage 53 communicate with each other. For this reason, pressure oil is supplied to the first hydraulic chamber 47 via the pressure oil passage 51 and the first piston oil passage 53.

  When the pressure oil in the pilot hydraulic chamber 46 is reduced to a predetermined pilot pressure from the state shown in FIG. 5, the pilot spool 34 rises to a position where the force corresponding to the pilot pressure and the spring force of the coil spring 65 are balanced. Accordingly, the first spool land 61 is displaced upward with respect to the upper opening of the second piston oil passage 54. For this reason, the second piston oil passage 54 and the pressure oil passage 51 communicate with each other, and pressure oil is supplied to the second hydraulic chamber 48. Simultaneously with this operation, the second spool land 62 is displaced upward with respect to the upper opening of the first piston oil passage 53. For this reason, the first piston oil passage 53 and the return oil passage 63 communicate with each other, and a part of the pressure oil in the first hydraulic chamber 47 is drained. As a result, the hydraulic piston 31 rises so as to follow the pilot spool 34. The raising operation of the hydraulic piston 31 ends when the first and second piston oil passages 53 and 54 are closed by the first and second spool lands 61 and 62. The hydraulic piston 31 similarly stops at a position corresponding to the stop position of the pilot spool 34.

  When the pilot pressure is completely released, the pilot spool 34 moves upward until the upper end of the holding member 64 comes into contact with the ceiling surface of the pilot hydraulic chamber 46. Following this movement, the hydraulic piston 31 is actuated and rises until its upper end abuts against the partition member 44. When the pilot spool 34 and the hydraulic piston 31 are both moved to the uppermost position in this manner, the first and second piston oil passages 53 and 54 are respectively in the state where the second hydraulic chamber 48 is filled with the pressure oil. Closed by the second spool lands 61 and 62.

  When the hydraulic piston 31 is moved again to a predetermined position below, a pilot pressure is supplied to lower the pilot spool 34 to a predetermined position. Accordingly, the second piston oil passage 54 communicates with the return oil passage 63 again, a part of the pressure oil in the second hydraulic chamber 48 is drained, and the hydraulic piston 31 is lowered. This lowering operation is terminated when the first and second piston oil passages 53 and 54 are closed by the first and second spool lands 61 and 62, and the hydraulic piston 31 is positioned according to the stop position of the pilot spool 34. Stop in the same way.

  As described above, as the pilot pressure is lowered, the pilot spool 34 rises with respect to the hydraulic piston 31, and the hydraulic piston 31 also rises following the movement. Further, as the pilot pressure is increased, the pilot spool 34 is lowered with respect to the hydraulic piston 31, and the hydraulic piston 31 is also lowered following the movement.

[Control system configuration]
Next, the configuration of the control device of the hydraulic servo drive device 30 will be described with reference to FIGS.

  FIG. 6 is a block diagram showing the configuration of the control device of the hydraulic servo drive device 30. As shown in FIG. 6, the control device of the hydraulic servo drive device 30 includes a controller 100. The controller 100 is realized by a microcomputer including a CPU, a RAM, a ROM, an input / output circuit, and the like. In the ROM of the microcomputer, a control program and a target upper limit value table described later are stored in advance.

  The CPU in the controller 100 loads the control program stored in the ROM into the RAM, and executes the control program loaded in the RAM, thereby increasing the opening of the nozzle unit 11 via the hydraulic piston 31. Control. Specifically, the controller 100 uses the magnitude of the magnetic force detected by the magnetic force sensor 82 as a feedback signal, and proportionally controls an electrical signal that controls the opening degree of the electromagnetic proportional valve 80 according to the feedback signal, whereby the hydraulic piston 31. Is controlled to the target position. Thereby, the exhaust introduction wall 12 approaches / separates from the exhaust introduction wall 13, and the opening degree of the nozzle part 11 can be controlled to the target opening degree.

  FIG. 7 is a functional block diagram showing the configuration of the controller 100 shown in FIG. As shown in FIG. 7, the controller 100 includes a vehicle state determination unit 110, a target position setting unit 120, a detection unit 130, a target position restriction unit 140, and an adjustment / operation unit 150. The vehicle state determination unit 110 is connected to the speed stage sensor 111, the work machine sensor 112, and the DPF regeneration instruction button 113.

  The speed stage sensor 111 detects the position of the transmission of the construction machine, and inputs a signal indicating the detected position to the vehicle state determination unit 110. The work machine sensor 112 detects an operation amount of a work machine lever that operates the work machine of the construction machine, and inputs a signal indicating the detected operation quantity to the vehicle state determination unit 110. The DPF regeneration instruction button 113 is a signal indicating that a DPF regeneration instruction flag indicating that execution of the forced regeneration process of the DPF is instructed is turned on in response to an instruction to perform the forced regeneration process of the DPF. Is input to the vehicle state determination unit 110.

  The vehicle state determination unit 110 determines the state of the construction machine based on signals from the speed stage sensor 111, the work machine sensor 112, and the DPF regeneration instruction button 113, and sends a control signal indicating the determination result to the target position setting unit 120. Output. Specifically, the vehicle state determination unit 110 determines whether the DPF regeneration instruction flag is on based on the signals from the speed stage sensor 111, the work machine sensor 112, and the DPF regeneration instruction button 113, and the construction machine. Is determined to be operating, and a control signal indicating the determination result is output to the target position setting unit 120. The speed stage sensor 111, the work machine sensor 112, and the DPF regeneration instruction button 113 function as a speed stage detection unit, a work machine detection unit, and a DPF regeneration instruction unit according to the present invention.

  The target position setting unit 120 sets the target position of the exhaust introduction wall 12 relative to the exhaust introduction wall 13, that is, the opening degree of the nozzle unit 11. The detection unit 130 identifies the position of the hydraulic piston 31 based on the magnitude of the magnetic force detected by the magnetic sensor 82, and the current position of the exhaust introduction wall 12 relative to the exhaust introduction wall 13 based on the identified position of the hydraulic piston 31. Calculate the position. The detection unit 130 outputs the calculated position information of the exhaust introduction wall 12 to the target position restriction unit 140.

  The target position restriction unit 140 determines the control target position of the exhaust introduction wall 12 based on the target position set by the target position setting unit 120 and the current position calculated by the detection unit 130, and determines the determined control target position. Output to the adjustment / operation unit 150. The adjustment / operation unit 150 controls the opening of the electromagnetic proportional valve 80 so that the exhaust introduction wall 12 approaches / separates the exhaust introduction wall 13 toward the control target position determined by the target position restriction unit 140. Is output.

  FIG. 8 is a functional block diagram showing the configuration of the target position restriction unit 140 shown in FIG. As shown in FIG. 8, the target position restriction unit 140 includes a target position table storage unit 141, a target position calculation processing unit 142, and a minimum value selection unit 143. The target position table storage unit 141 indicates the relationship between the current position of the exhaust introduction wall 12 and the target position when controlling the exhaust introduction wall 12 in the direction in which the exhaust introduction wall 12 is brought close to the exhaust introduction wall 13, that is, the direction in which the nozzle unit 11 is closed. A target position table is stored. Details of the target position table will be described later.

  The target position calculation processing unit 142 refers to the target position table stored in the target position table storage unit 141 and extracts a target position corresponding to the current position of the exhaust introduction wall 12 detected by the detection unit 130. The minimum value selection unit 143 has a smaller value between the target position of the exhaust introduction wall 12 set by the target position setting unit 120 and the target position of the exhaust introduction wall 12 extracted by the target position calculation processing unit 142. That is, the target position with the larger opening of the nozzle portion 11 is output as the control target position of the exhaust introduction wall 12.

[Configuration of target position table]
Next, the configuration of the target position table stored in the target position table storage unit 141 will be described with reference to FIGS. 9 to 11. FIG. 9 is a diagram illustrating an example of the target position table. FIG. 10 is a graph of the target position table shown in FIG. FIG. 11 is a view for explaining a notation method of the position of the exhaust introduction wall 12 in the present embodiment.

  As shown in FIGS. 9 and 10, the target position table has a configuration in which the target position of the exhaust introduction wall 12 is described for each current position of the exhaust introduction wall 12. In the present embodiment, as shown in FIG. 11, the position of the exhaust introduction wall 12 is the degree of approach [%] of the exhaust introduction wall 12 to the exhaust introduction wall 13, that is, the ratio at which the nozzle portion 11 is closed by the exhaust introduction wall 12. [%]. That is, when the nozzle part 11 is in the fully open state, the position of the exhaust introduction wall 12 is represented as 0 [%], and when the nozzle part 11 is in the fully closed state, the position of the exhaust introduction wall 12 is 100 [%]. It is expressed. In the present embodiment, the position of the exhaust introduction wall 12 is expressed by the opening degree of the nozzle portion 11. However, the present invention is not limited to this notation method, and the position of the exhaust introduction wall 12 is determined by, for example, coordinate values. It may be expressed.

  Each of the target positions shown in FIGS. 9 and 10 is a case where the control amount of the hydraulic servo drive device 30 overshoots from the target value when the exhaust introduction wall 12 is moved from the corresponding current position toward the target position. However, the maximum value is set such that the exhaust introduction wall 12 does not contact the exhaust introduction wall 13. A method for setting each target position will be described later. When the current position of the exhaust introduction wall 12 is within a predetermined range from the fully closed position 100 [%], the target position is set to the fully closed position 100 [%]. In the present embodiment, the target position is set to the fully closed position 100 [%] with the current position of the exhaust introduction wall 12 being 90 [%] or more as a predetermined range, but the predetermined range is appropriately set. Is possible.

  When the current position of the exhaust introduction wall 12 is within a predetermined range from the fully closed position 100 [%] (in this embodiment, the current position of the exhaust introduction wall 12 is 90 [%] or more and control is continued. There are two reasons why the target position is set to the fully closed position 100 [%] when The first reason is that even when the control amount of the hydraulic servo drive device 30 overshoots from the target value when the exhaust introduction wall 12 is moved from the current position toward the fully closed position 100 [%], This is because the degree of collision of the exhaust introduction wall 12 with the exhaust introduction wall 13 is small, and there is no fear of breakage. The second reason is that the control amount of the hydraulic servo drive device 30 is the target value in the target position where the current position of the exhaust introduction wall 12 is within a predetermined range from the fully closed position 100 [%], as in the other target positions. When the exhaust introduction wall 12 is set to a size that does not come into contact with the exhaust introduction wall 13 by overshooting, the exhaust introduction wall 12 slowly approaches the exhaust introduction wall 13 and the response speed becomes slow. It is. Therefore, the predetermined range in which the target upper limit position is the fully closed position 100 [%] is set in consideration of the degree of collision of the exhaust introduction wall 12 with respect to the exhaust introduction wall 13 and the response speed.

  As described above, in the present embodiment, the target position is set to the fully closed position 100 [%] when the current position of the exhaust introduction wall 12 is within a predetermined range from the fully closed position 100 [%]. If a slight delay is allowed, as shown in FIGS. 12 and 13, the exhaust introduction wall 12 exhausts all target positions when the control amount of the hydraulic servo drive device 30 overshoots from the target value. You may make it set to the maximum value of the magnitude | size which does not contact the introductory wall 13. FIG.

[Target position setting method]
Next, a method for setting a target position in the target position table will be described based on some specific examples with reference to FIGS.

  As described above, the target position of the exhaust introduction wall 12 is the maximum size in which the exhaust introduction wall 12 does not contact the exhaust introduction wall 13 even when the control amount of the hydraulic servo drive device 30 overshoots from the target value. Set to a value. However, this maximum value changes according to the current position of the exhaust introduction wall 12. Therefore, in the following, when the current position of the exhaust introduction wall 12 is 0 [%], 40 [%], and 60 [%], the control amount of the hydraulic servo drive device 30 overshoots from the target value. Even if it exists, the maximum value of the magnitude | size which the exhaust introduction wall 12 does not contact the exhaust introduction wall 13 is calculated.

  FIG. 14 shows that the target position is set to (a) 100 [%], (b) 80 [%], and (c) 70 [%] when the current position of the exhaust introduction wall 12 is the fully open position 0 [%]. It is a simulation waveform diagram which shows the change of the position of the exhaust introduction wall 12 with time passage in the case.

  As shown in FIG. 14A, when the target position is set to the fully closed position 100 [%], the control amount of the hydraulic servo drive device 30 overshoots the target value at time T = T1, The exhaust introduction wall 12 collides with the exhaust introduction wall 13. Further, as shown in FIG. 14B, when the target position is set to the position 80 [%], the control amount of the hydraulic servo drive device 30 exceeds the target value at time T = T2. Shooting occurs, and the exhaust introduction wall 12 collides with the exhaust introduction wall 13. On the other hand, as shown in FIG. 14C, when the target position is set to the position 70 [%], even if the control amount of the hydraulic servo drive device 30 overshoots the target value, The exhaust introduction wall 12 is controlled to the position 70 [%] which is the target position without contacting the exhaust introduction wall 13.

  From the above, when the current position of the exhaust introduction wall 12 is the fully open position 0 [%], the contact of the exhaust introduction wall 12 with the exhaust introduction wall 13 is suppressed by setting the target position to 70 [%]. On the other hand, the knowledge that the position of the exhaust introduction wall 12 can be brought close to the fully closed position quickly can be obtained.

  FIG. 15 shows the exhaust introduction wall over time when the target position is set to (a) 100 [%] and (b) 82 [%] when the current position of the exhaust introduction wall 12 is at the position 40 [%]. It is a simulation waveform diagram which shows the change of 12 positions.

  As shown in FIG. 15A, when the target position is set to the fully closed position 100 [%], the control amount of the hydraulic servo drive device 30 overshoots the target value at time T = T3, The exhaust introduction wall 12 collides with the exhaust introduction wall 13. On the other hand, as shown in FIG. 15B, when the target position is set to the position 82 [%], even if the control amount of the hydraulic servo drive device 30 overshoots the target value, The exhaust introduction wall 12 is controlled to the target position 82 [%] without contacting the exhaust introduction wall 13.

  From the above, when the current position of the exhaust introduction wall 12 is at the position 40 [%], the contact of the exhaust introduction wall 12 with the exhaust introduction wall 13 is suppressed by setting the target position to 82 [%]. The knowledge that the position of the exhaust introduction wall 12 can be quickly brought close to the fully closed position is obtained.

  FIG. 16 shows the exhaust introduction wall over time when the target position is set to (a) 100 [%] and (b) 88 [%] when the current position of the exhaust introduction wall 12 is at the position 60 [%]. It is a simulation waveform diagram which shows the change of 12 positions.

  As shown in FIG. 16A, when the target position is set to the fully closed position 100 [%], the control amount of the hydraulic servo drive device 30 overshoots the target position at time T = T4, The exhaust introduction wall 12 collides with the exhaust introduction wall 13. On the other hand, as shown in FIG. 16B, when the target position is set to the position 88 [%], even if the control amount of the hydraulic servo drive device 30 overshoots the target position, The exhaust introduction wall 12 is controlled to a position 88 [%] which is a target position without contacting the exhaust introduction wall 13.

  From the above, when the current position of the exhaust introduction wall 12 is at the position 60 [%], the target position is set to 88 [%], thereby suppressing the contact of the exhaust introduction wall 12 with the exhaust introduction wall 13. The knowledge that the position of the exhaust introduction wall 12 can be brought close to the fully closed position is obtained.

  As described above, the target position of the exhaust introduction wall 12 is set to the maximum value of the target position at which the exhaust introduction wall 12 does not contact the exhaust introduction wall 13 when the control amount of the hydraulic servo drive device 30 overshoots from the target value. Thus, the position of the exhaust introduction wall 12 can be brought close to the fully closed position while suppressing the contact of the exhaust introduction wall 12 with the exhaust introduction wall 13.

[Fully closed control processing]
In the variable turbocharger 1 having such a configuration, the controller 100 executes the fully-closed control process described below, whereby the nozzle unit 11 is quickly fully closed while preventing the nozzle unit 11 from being damaged. Control to the state. Hereinafter, the flow of the fully-closed control process by the controller 100 will be described with reference to the flowchart shown in FIG.

  The fully closed control process by the controller 100 starts at the timing when the ignition switch of the construction machine equipped with the variable turbocharger 1 is switched from the off state to the on state, and the fully closed control process proceeds to the process of step S1. . This fully-closed control process is repeatedly executed every predetermined control cycle while the ignition switch of the construction machine is in the ON state.

  In the process of step S1, the vehicle state determination unit 110 of the controller 100 determines whether or not the DPF regeneration instruction flag is on based on the input signal from the DPF regeneration instruction button 113. As a result of the determination, if the DPF regeneration instruction flag is in the ON state, the controller 100 determines that the forced regeneration process of the DPF has been instructed, and advances the fully closed control process to the process of step S2. On the other hand, when the DPF regeneration instruction flag is in the OFF state, the controller 100 determines that the DPF forced regeneration process is not instructed, and ends the fully closed control process.

  In the process of step S2, as shown in FIG. 7, the vehicle state determination unit 110 of the controller 100 determines whether or not the construction machine is operating. Specifically, the controller 100 determines whether the position of the transmission of the construction machine is in the traveling position based on the input signals from the speed stage sensor 111 and the work implement sensor 112, or the work implement lever is being operated. It is determined whether or not there is. Then, when the position of the transmission of the construction machine is in the traveling position or the work implement lever is being operated, the controller 100 determines that the construction machine is in operation. On the other hand, when the position of the transmission of the construction machine is in the parking position and the work implement lever is in the neutral position and is not operated, the controller 100 determines that the construction machine is not in operation. As a result of the determination, when the construction machine is in operation, the controller 100 needs to promptly fully close the nozzle portion 11 in order to prevent soot from being discharged due to incomplete combustion of the dosing fuel. It is determined that there is, and the fully closed control process proceeds to the process of step S3. On the other hand, when the construction machine is not operating, the controller 100 determines that the nozzle unit 11 does not need to be fully closed immediately, and advances the fully closed control process to the process of step S7.

  In the process of step S3, the detection unit 130 of the controller 100 detects the current position [%] of the exhaust introduction wall 12. Thereby, the process of step S3 is completed, and the fully closed control process proceeds to the process of step S4.

  In the process of step S4, the target position calculation processing unit 142 in the target position limiting unit 140 of the controller 100 sets the target position corresponding to the current position of the exhaust introduction wall 12 detected by the process of step S3 from the target position table. Get the data. The controller 100 functions as the target position setting unit 120 to set the target position of the exhaust introduction wall 12 to the fully closed position 100 [%]. Thereby, the process of step S4 is completed and the fully closed control process proceeds to the process of step S5.

  In the process of step S <b> 5, the minimum value selection unit 143 in the target position restriction unit 140 of the controller 100 is set by the target position of the exhaust introduction wall 12 acquired by the target position calculation processing unit 142 and the target position setting unit 120. The position of the exhaust introduction wall 12 having a smaller value with respect to the target position of the exhaust introduction wall 12, that is, the larger opening of the nozzle portion 11, is determined as the control target position. Thereby, the process of step S5 is completed, and the fully closed control process proceeds to the process of step S6.

  In the process of step S6, the adjustment / operation unit 150 of the controller 100 sends a current command value to the electromagnetic proportional valve 80 so that the exhaust introduction wall 12 moves toward the control target position determined by the target position restriction unit 140. Output and control pilot pressure. Thereby, the process of step S6 is completed and a series of fully closed control processes are complete | finished.

  On the other hand, in the process of step S7, when the position of the transmission of the construction machine is in the parking position and the work implement lever is in the neutral position, as shown in FIG. A value obtained by adding a predetermined incremental current ΔI (> 0) to the current command value I ′ output to the electromagnetic proportional valve 80 is calculated as the current command value I output to the electromagnetic proportional valve 80. Thereby, the process of step S7 is completed, and the fully closed control process proceeds to the process of step S8.

  In the process of step S8, as shown in FIG. 7, the controller 100 determines that the current command value I calculated by the process of step S7 is greater than or equal to the maximum current command value Imax when controlling the nozzle unit 11 to the fully closed state. It is determined whether or not. As a result of the determination, if the current command value I is equal to or greater than the maximum current command value Imax, the controller 100 advances the fully closed control process to the process of step S9. On the other hand, when the current command value I is less than the maximum current command value Imax, the controller 100 advances the fully closed control process to the process of step S10.

  In the process of step 9, the controller 100 outputs the maximum current command value Imax to the electromagnetic proportional valve 80. Thereby, the process of step S9 is completed and a series of fully closed control processes are complete | finished.

  In the process of step S10, the controller 100 outputs the current command value I calculated by the process of step S7 to the electromagnetic proportional valve 80. Thereby, the process of step S10 is completed and a series of fully closed control processes are complete | finished.

  Finally, with reference to FIG.18 and FIG.19, the effect acquired by the control method of the variable turbocharger 1 of this embodiment is demonstrated.

  FIG. 18 shows the current position and the target position of the exhaust introduction wall 12 when the nozzle unit 11 is quickly controlled to the fully closed state when the conventional technology and the control method of the variable turbocharger 1 of the present embodiment are used. FIG. FIG. 19 shows (a) the electromagnetic proportional valve 80 when it is not necessary to quickly control the nozzle portion 11 to the fully closed state when the control method for the variable turbocharger 1 of the present embodiment is used. It is a figure which shows the time-dependent change of the electric current command value I and (b) the position of the exhaust introduction wall 12. FIG.

  In FIG. 18, reference symbol L <b> 1 is a curve showing the time change of the control target position of the exhaust introduction wall 12 in the control method of the variable turbocharger 1 of the present embodiment. Reference symbol L2 is a curve showing the time change of the position of the exhaust introduction wall 12 when the target position table shown in FIGS. 9 and 10 is used. Reference symbol L3 is a curve showing the time change of the position of the exhaust introduction wall 12 when the target position table shown in FIGS. 12 and 13 is used. Reference symbol L4 is a curve showing the change over time of the control target position of the exhaust introduction wall 12 in the prior art. Reference numeral L5 is a curve showing a change over time of the position of the exhaust introduction wall 12 in the prior art. The curve indicating the time change of the control target position corresponding to the curve L3 is a value of the control target position indicated by the curve L1 only when the current position of the exhaust introduction wall 12 is within a predetermined range from the fully closed position. Since it is only different from FIG.

  In the prior art, in order to prevent the exhaust introduction wall 12 from strongly colliding with the exhaust introduction wall 13 when controlling the nozzle portion 11 to the fully closed state, the deviation between the actual opening and the target opening of the hydraulic servo valve is set. Limit to a predetermined level range. Therefore, in the prior art, the control target position of the exhaust introduction wall 12 changes linearly as shown by a curve L4 in FIG. 18, and the exhaust introduction wall 12 changes as shown by a curve L5 in FIG. Even if it collides with the exhaust introduction wall 13, it is controlled to the fully closed position 100 [%] at a constant speed that causes no problem. For this reason, according to the prior art, when the exhaust gas temperature is lower than a predetermined temperature when the forced regeneration process of the DPF is executed, that is, when it is necessary to quickly control the nozzle portion 11 to the fully closed state, The nozzle portion 11 cannot be quickly controlled to a fully closed state, and soot may be discharged due to incomplete combustion of the dosing fuel.

  On the other hand, in the control method of the variable turbocharger 1 according to the present embodiment, as described above, when there is a need to quickly control the nozzle portion 11 to the fully closed state, the controller 100 in FIG. As shown by the curve L1, the target position is controlled to the maximum value of the target position where the exhaust introduction wall 12 does not contact the exhaust introduction wall 13 even if the control amount of the hydraulic servo drive device 30 overshoots the target value. According to such a control method, the curve L2 in FIG. 18 (the curve showing the time change of the position of the exhaust introduction wall 12 when using the target position table shown in FIGS. 9 and 10) and the curve L3 ( As is apparent from a comparison between the curve L5 and the curve of the position of the exhaust introduction wall 12 when the target position table shown in FIGS. 12 and 13 is used, and the curve L5, the exhaust introduction wall can be obtained in a shorter time than the prior art. 12 is controlled to the fully closed position 100 [%], and the nozzle portion 11 can be quickly controlled to the fully closed state. Further, the target position of the exhaust introduction wall 12 is designed to the maximum value of the target position where the exhaust introduction wall 12 does not contact the exhaust introduction wall 13 even if the control amount of the hydraulic servo drive device 30 overshoots the target value. Therefore, the nozzle portion 11 can be prevented from being damaged by the exhaust introduction wall 12 strongly colliding with the exhaust introduction wall 13.

  On the other hand, when the position of the transmission of the construction machine is in the parking position and the work implement lever is in the neutral position, that is, when it is not necessary to quickly control the nozzle portion 11 to the fully closed state, the controller 100 19 (a), the current command value I for the electromagnetic proportional valve 80 is changed by a predetermined increment ΔI / ΔT (ΔT: control period), thereby providing an exhaust introduction wall as shown in FIG. 19 (b). 12, the exhaust introduction wall 12 is strongly controlled against the exhaust introduction wall 13 because the exhaust introduction wall 12 is controlled to the fully closed position 100 [%] at a constant speed that does not cause a problem even if the exhaust introduction wall 12 collides with the exhaust introduction wall 13. By colliding, it can prevent that the nozzle part 11 is damaged. In this case, a curve indicating the time change of the position of the exhaust introduction wall 12 is, for example, a curve L5 shown in FIG.

  The embodiment to which the invention made by the present inventors has been described has been described above, but the present invention is not limited by the description and drawings that form part of the disclosure of the present invention according to the above embodiment. For example, in this embodiment, when the construction machine is in operation, the nozzle unit 11 is quickly controlled to be fully closed. However, regardless of whether or not the construction machine is in operation, the forced regeneration processing of the DPF is performed. When executing, the nozzle unit 11 may be promptly controlled to be fully closed. In the present embodiment, the exhaust introduction wall 12 strongly collides with the exhaust introduction wall 11 when the exhaust introduction wall 12 approaches the exhaust introduction wall 13, that is, when the nozzle portion 11 is controlled to be fully closed. The nozzle portion 11 was quickly controlled to be fully closed while being suppressed. However, the technical idea of the present invention is not limited to the control in the case of controlling the nozzle portion 11 to the fully closed state, and the direction in which the exhaust introduction wall 12 is separated from the exhaust introduction wall 13, that is, the nozzle portion 11 is fully opened. In the case of controlling to the state, the present invention can also be applied to the case where the nozzle portion 11 is quickly controlled to the fully open state while suppressing the movable ring 15 from strongly colliding with the wall surface of the storage chamber 17. As described above, other embodiments, examples, operation techniques, and the like made by those skilled in the art based on the above-described embodiments are all included in the scope of the present invention.

  The present invention can be used in a control device for a variable turbocharger that controls the nozzle portion of the variable turbocharger to a fully closed state.

DESCRIPTION OF SYMBOLS 1 Variable turbocharger 10 Exhaust introduction path 11 Nozzle part 12, 13 Exhaust introduction wall 30 Hydraulic servo drive device 31 Hydraulic piston 80 Electromagnetic proportional valve 81 Moving member 81a Magnet 82 Magnetic sensor 100 Controller 110 Vehicle state discrimination | determination part 111 Speed stage sensor 112 Working machine sensor 113 DPF regeneration instruction button 120 Target position setting unit 130 Detection unit 140 Target position restriction unit 141 Target position table storage unit 142 Target position calculation processing unit 143 Minimum position selection unit 150 Adjustment / operation unit

Claims (7)

In the control device for the variable turbocharger that controls the opening area of the exhaust introduction passage by moving the exhaust introduction member provided in the exhaust introduction passage of the variable turbocharger by operating the hydraulic servo valve.
A detector for detecting a current position of the exhaust introduction member;
A controller for adjusting a control amount of the hydraulic servo valve by feeding back a current position of the exhaust introduction member detected by the detector;
When the controller closes the exhaust introduction passage, even if the control amount of the hydraulic servo valve overshoots, the current position of the exhaust introduction member does not become the fully closed position where the exhaust introduction passage is closed. A control device for a variable turbocharger, wherein a control amount of the hydraulic servo valve is output using a control target position smaller than a target value corresponding to the control value.   2. The variable turbo overload according to claim 1, wherein when the current position of the exhaust introduction member is within a predetermined range from the fully closed position, a control target position of the exhaust introduction member is set to the fully closed position. Feeder control device. A DPF regeneration instruction unit for instructing execution of a forced regeneration process of a diesel particulate filter that reduces the amount of particulate matter contained in exhaust gas discharged from a diesel engine;
3. The control of the variable turbocharger according to claim 1, wherein when the DPF regeneration instructing unit instructs execution of forced regeneration processing of the diesel particulate filter, the feedback control is performed. apparatus. A speed stage detection unit for detecting a position of a transmission of a construction machine using the diesel engine as a drive source;
A work machine detection unit for detecting an operation amount of the work machine of the construction machine,
Based on the detection results of the speed stage detection unit and the work implement detection unit, the feedback control is executed when the position of the transmission is in a travel position or when the work implement is in operation. The control device for a variable turbocharger according to claim 3.   Based on the detection results of the speed stage detection unit and the work implement detection unit, when the transmission is in the parking position and the work implement is in the neutral position, the exhaust introduction member is moved at a constant speed. The control device for a variable turbocharger according to claim 4, wherein the control device is controlled to a closed position.   Even if the control amount of the hydraulic servo valve overshoots from the target value, the position of the exhaust introduction member does not become the fully closed position for closing the exhaust introduction path, and the control target position of the exhaust introduction member When the exhaust introduction path is closed, the control target position of the exhaust introduction member is feedback controlled based on the current position of the exhaust introduction member based on the table. Item 6. The variable turbocharger control device according to any one of Items 1 to 5. In the control method of the variable turbocharger that controls the opening area of the exhaust introduction path by moving the exhaust introduction member provided in the exhaust introduction path of the variable turbocharger by operating the hydraulic servo valve.
A detection step of detecting a current position of the exhaust introduction member;
Adjusting the control amount of the hydraulic servo valve by feeding back the current position of the exhaust introduction member detected in the detection step,
In the adjustment step, when the exhaust introduction path is closed, even if the control amount of the hydraulic servo valve overshoots, the position of the exhaust introduction member does not become the fully closed position that closes the exhaust introduction path. A control method for a variable turbocharger, comprising: outputting a control amount of the hydraulic servovalve using a control target position smaller than a target value corresponding to the position.

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