JP2010223035A - Variable nozzle control device for turbocharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect the fully opened or fully closed position of a variable nozzle. <P>SOLUTION: The variable nozzle control device for a turbocharger includes: a motor-rotational-speed detection means for detecting the rotational speed of the motor for controlling the opening of the vave of a variable nozzle by controlling the rotating angel of the ratating shaft of a motor based on a control signal from an engine control device for controlling engine drive equipped with a turbocharger with variable nozzles; and a supply-current control means for controlling a current amount supplied to the motor so that the rotational speed of the motor detected by the motor rotational speed detection means is equal to a predetermined target rotational speed. When performing an initialization operation to obtain a position where the vane of the variable nozzle abuts on a stopper, the supply-current control means controls the current before the rotational speed of the motor reaches the target rotational speed, and maintains constant and supplies the current supplied to the motor after the motor rotational speed reaches the target rotational speed to maintain constant the rotational speed of the motor immediately before the vane of the variable nozzle abuts on the stopper. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a variable nozzle control device for a turbocharger that controls an opening degree of a vane of a variable nozzle of a turbocharger mounted on an automobile with an electronic control actuator in accordance with a control signal from an engine control device.

  Conventionally, as an example of this type of technology, a variable nozzle turbocharger control device for an internal combustion engine disclosed in Patent Document 1 is known. FIG. 4 is a diagram showing a configuration of a variable nozzle turbocharger control device according to the prior art. In FIG. 4, reference numeral 1 denotes a turbocharger, which includes a center housing, a compressor housing, and a turbine housing. The turbocharger 1 is provided with an intake inlet 1a through which air is introduced, and a compressed air supply hole 1b for supplying the air compressed by the turbocharger 1 to the engine 2, and exhaust gas is further supplied from the engine 2. An exhaust gas suction port 1c and a discharge port 1d for discharging the exhaust gas are provided. A variable nozzle (not shown) provided in the turbocharger 1 is disposed between the center housing and the turbine housing.

  Reference numeral 3 denotes a stepping motor. The operation piece 4 is operated by driving the stepping motor 3, and the ring plate provided in the variable nozzle is pressed in the same direction to adjust the size of the gap between the vanes of the variable nozzles. The flow rate of the exhaust gas blown to the turbine wheel is adjusted. Reference numeral 5 denotes an engine ECU (electronic control unit), which receives detection outputs of various sensors provided in the engine, and based on these detection outputs, identifies the operating state of the engine and controls driving of the stepping motor 3. This controls the opening and closing of the vane opening of each nozzle of the variable nozzle, adjusts the flow rate of the exhaust gas blown to the turbine wheel, and also adjusts the amount of air that is forcibly sent for combustion. Is done. A radiator 6 is connected to the engine 2, and cooling water of the engine 2 is circulated through the radiator 6 to be cooled.

  According to this prior art, when an abnormality occurs in the variable nozzle turbocharger control device of the internal combustion engine, during cold start, or at idling, the fully open position of the variable nozzle is set as the initial position of the variable nozzle so that The position of each nozzle vane can be controlled.

  In addition, in a variable nozzle control device for a turbocharger, soot may stick to or stay on the nozzle ring surface in the operating angle range other than the normal operating range of the variable nozzle vane. In accordance with the status indication information from the engine ECU based on the stop of the engine due to the switch being turned off, the vane is operated to the fully open position through the fully closed position at least once in the entire operation area of the vane of the variable nozzle. There are also known variable nozzle control devices capable of performing separation. (For example, refer to Patent Document 2). The operation for performing the separation is called wiping operation. In the wiping operation, when the ignition key is turned off, a wiping command is output from the engine ECU. In response to this, the variable nozzle vane is operated until it hits the fully-closed mechanical stopper, and is then operated until it hits the fully-opened mechanical stopper. When this wiping operation is completed, a power OFF permission signal is output and the power of the variable nozzle control device is turned OFF. By this operation, it is possible to execute the dismissal after the engine is stopped.

JP 2001-107738 A JP 2004-293537 A

  However, in the turbocharger variable nozzle control device shown in Patent Document 2, in the initialization operation including the wiping operation performed when the ignition key is turned on or off, the motor drive duty value (supply current) is made constant to adjust the variable nozzle. Since the vane is abutted against the mechanical stopper and the stopper position is determined, the motor speed at the time of abutting the stopper changes due to changes in the external environment such as the voltage, temperature and load on the motor. As shown in FIG. 5, when the motor drive duty value (supply current) supplied to the motor is constant, the actual rotation of the motor is smaller when the load on the motor is smaller than when the load on the motor is large. The number increases, and the motor rotation speed immediately before hitting the mechanical stopper is different. If the rotational speed of the motor immediately before the vane of the variable nozzle hits the mechanical stopper varies due to a change in the external environment with respect to the motor, there is a problem in that the stopper position for determining the fully open and fully closed positions cannot be accurately detected.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a variable nozzle control device for a turbocharger that can accurately detect the fully open or fully closed position of a variable nozzle.

  The present invention relates to a vane for a variable nozzle provided in the turbocharger by controlling a rotation angle of a rotating shaft of a motor based on a control signal from an engine control device that controls driving of the engine having a turbocharger having a variable nozzle. A variable nozzle control device for a turbocharger provided with an electronic control actuator for controlling the opening degree of the motor, wherein the motor rotation number detection means detects the rotation number of the motor, and the motor is detected by the motor rotation number detection means Supply current control means for controlling the amount of current supplied to the motor such that the rotation speed of the variable nozzle is set to a predetermined target rotation speed, and the supply current control means performs an initialization operation to perform the variable nozzle When the position where the vane of the butt comes into contact with the stopper, the supply current control The amount of current supplied to the motor is maintained at a constant level after the target rotational speed is reached by controlling the amount of current by means of the motor immediately before the vane of the variable nozzle hits the stopper. It is characterized in that the rotational speed is made constant.

  The present invention relates to a vane for a variable nozzle provided in the turbocharger by controlling a rotation angle of a rotating shaft of a motor based on a control signal from an engine control device that controls driving of the engine having a turbocharger having a variable nozzle. A variable nozzle control program that operates on a variable nozzle control device of a turbocharger equipped with an electronic control actuator that includes a motor rotation number detecting means for detecting the rotation number of the motor, A supply current control step for controlling the amount of current supplied to the motor is performed by a computer so that the rotation speed of the motor detected by the motor rotation speed detection means becomes a predetermined target rotation speed, and the supply current control is performed. The step performs an initialization operation so that the vane of the variable nozzle hits the stopper When the target rotational speed is reached, the current amount is controlled by the supply current control means until the target rotational speed is reached, and after reaching the target rotational speed, the current amount supplied to the motor is kept constant. By holding and supplying, the rotational speed of the motor immediately before the vane of the variable nozzle hits the stopper is made constant.

  According to the present invention, since the motor rotation speed immediately before the vane of the variable nozzle hits the stopper is made constant, it is possible to accurately detect the fully open or fully closed position of the variable nozzle.

It is a block diagram which shows the structure of one Embodiment of this invention. It is a block diagram which shows the detailed structure of the electronic control actuator 13 shown in FIG. It is explanatory drawing which shows the change of the motor rotation speed at the time of initialization operation | movement. It is a block diagram which shows the prior art example of the variable nozzle control apparatus of a turbocharger. It is explanatory drawing which shows the change of the motor rotation speed at the time of the initialization operation | movement by a prior art.

  Hereinafter, a variable nozzle control device for a turbocharger according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing the configuration of the embodiment. In this figure, 8 is a turbocharger, which is a system for supercharging intake air to the engine, which is connected to a compressor having a compressor wheel and a rotor shaft coaxially with the compressor, and is driven to rotate by exhaust gas. A turbine having a turbine wheel of the turbocharger 8 is provided. A pressure sensor 9 is connected to the air passage 7 of the turbocharger 8 via a hose 10 for detecting intake pressure of engine intake air, that is, boost pressure. A variable nozzle member is disposed in the turbine of the turbocharger 8 so as to surround the turbine wheel. The variable nozzle member is provided with a vane that opens and closes in order to control the flow rate of the fluid flowing through the nozzle. The variable nozzle control device controls the opening and closing of the vanes.

  Reference numeral 11 denotes an engine ECU, which is provided with various sensors provided in the engine, for example, a water temperature sensor for detecting the engine water temperature, and for detecting the number of revolutions of the engine. A detection output of a water temperature signal, a rotation signal, and a load signal is introduced from an acceleration sensor that detects an intake air amount by an air flow meter and an accelerator pedal depression amount of a driver and calculates a load amount, respectively. Although not shown in FIG. 1, there may be provided an oxygen sensor that outputs a voltage signal that varies depending on the oxygen concentration of the exhaust gas, and an in-cylinder pressure sensor that detects the pressure in the engine combustion chamber.

  The electronic control actuator 13 is connected to the engine ECU 11 via a control signal line. The engine ECU 11 identifies the operating state of the engine based on the detection output, and drives and controls the electronic control actuator 13 via the control signal line. The electronic control actuator 13 connects the lever 19 and the rod 20, and controls the operation of the vane operation piece 21 connected to each vane in order to control the opening and closing of the vane provided in the turbocharger 8. To do.

  The electronic control actuator 13 is attached to the turbocharger 8, for example. Further, when the configuration of the electronic control actuator 13 is described with reference to FIG. 1 and FIG. 2, the publicly known functions and configurations normally possessed by the electronic control actuator 13 are the same unless directly related to the description of the present invention. Description and illustration of the configuration are omitted.

  Next, a detailed configuration of the electronic control actuator 13 shown in FIG. 1 will be described with reference to FIG. FIG. 2 is a block diagram showing a detailed configuration of the electronic control actuator 13 shown in FIG. In FIG. 2, reference numeral 130 denotes a microcomputer (hereinafter referred to as a microcomputer) that controls the operation of the electronic control actuator 13 in an integrated manner. A motor driver 14 drives a stepping motor (hereinafter referred to as a motor) 15 based on a drive signal output from the microcomputer 130. The motor 15 is a stepping motor whose rotation angle is controlled based on a signal output from the motor driver 14. Reference numeral 16 denotes a gear which is connected to the rotation shaft of the motor 15 and decelerates the rotation shaft of the motor. Reference numeral 17 denotes an output shaft decelerated by the gear 16. Reference numeral 18 denotes an angle sensor that detects and outputs the rotation angle of the output shaft 17. The output of the angle sensor 18 is input to the microcomputer 130.

  Reference numeral 131 denotes an angle signal conversion unit that receives a vane target position (opening) signal output from the engine ECU 11, converts the target position signal into an angle signal handled in the microcomputer 130, and outputs the angle signal. Reference numeral 132 denotes an angle at which a comparison result signal is output by comparing the angle signal of the target position output from the angle signal conversion unit 131 with the angle signal output from the angle sensor 18 (current vane angle (opening)). It is a signal comparison unit. Reference numeral 133 denotes a motor drive duty calculation unit that inputs the comparison result signal output from the angle signal comparison unit 132, and calculates and outputs the duty ratio of the signal to be given to the motor. A motor drive logic generation unit 134 receives a duty ratio signal output from the motor drive duty calculation unit 133 and obtains and outputs a logic signal to be given to the motor. Reference numeral 135 denotes a communication signal conversion unit that converts an angle signal output from the angle sensor 18 into a communication signal for transmission to the engine ECU 11 and outputs the communication signal. The angle information output from the communication signal conversion unit 135 is the actual position information of the current vane. Reference numeral 136 denotes a motor rotation speed detection unit that detects the rotation speed of the motor 15 and outputs a value of the rotation speed. Reference numeral 137 denotes a timer for measuring a predetermined time. The motor drive duty calculation unit 133 averages the drive duty values output within a predetermined time counted by the timer 137, and outputs the averaged drive duty value after the predetermined time elapses.

  Next, the basic operation of the electronic control actuator 13 shown in FIG. 2 will be described with reference to FIG. When the target position signal is output from the engine ECU 11, the angle signal conversion unit 131 converts the target position signal into an angle signal handled in the microcomputer 130 and outputs the angle signal. The angle signal comparison unit 132 compares the angle signal of the target position output from the angle signal conversion unit 131 with the angle signal (current vane angle) output from the angle sensor 18 to determine the current vane angle as a target. To obtain the position, the motor drive duty is calculated and output. In response to this, the motor drive logic generation unit 134 receives the duty signal output from the motor drive duty calculation unit 133 and obtains and outputs a logic signal (motor drive signal) to be given to the motor driver 14.

  The motor driver 14 drives the motor 15 based on the motor drive signal output from the motor drive logic generation unit 134. The rotation shaft of the motor is decelerated by the gear 16 and transmitted to the output shaft 17. The rotational movement of the output shaft 17 is transmitted to the vane operation piece 21 via the lever 19 and the rod 20. As the vane operating piece 21 operates in conjunction with the output shaft 17, the nozzle vane opening / closing control operation is performed. On the other hand, information on the rotation angle of the output shaft 17 detected by the angle sensor 18 is notified to the engine ECU 11 via the communication signal converter 135. The engine ECU 11 controls the operation of the turbocharger 8 with reference to the information on the rotation angle of the output shaft (nozzle vane opening).

  In this way, the rotation angle of the output shaft 17 connected to the vanes of the variable nozzle is detected by the angle sensor 18 and the actual angle signal of the output shaft 17 is output, and the angle signal converter 131 receives the variable nozzle of the variable nozzle from the engine ECU 11. By converting the vane opening degree instruction (target position signal) into a target angle signal of the output shaft 17, comparing both signals, and controlling the rotation angle of the output shaft 17 according to the difference between the two signals, Control is performed so that the vanes of the variable nozzle become the target position.

  Next, a control operation in which the microcomputer 130 shown in FIG. 2 performs an initialization operation including a wiping operation will be described with reference to FIG. FIG. 3 is an explanatory diagram showing changes in the motor rotation speed during the initialization operation. First, upon receiving an initialization command including the target rotational speed information of the motor, the motor drive duty calculation unit 133 reads the rotational speed information of the motor 15 output from the motor rotational speed detection unit 136 and reads the target rotational speed (for example, 1500 rpm). ) And the current rotational speed (output value of the motor rotational speed detection unit 136), a drive duty value to be output to the motor drive logic generation unit 134 is obtained based on a value obtained by PI (proportional / integral) calculation, and the obtained drive The duty value is output to the motor drive logic generation unit 134. This operation is continued for a predetermined time (for example, 200 ms) with reference to the timing information output by the timer 137. By this operation, the rotation speed of the motor reaches the vicinity of the target rotation speed through the motor acceleration period. However, the time until the value output by the motor rotation speed detection unit 136 reaches the target rotation speed varies depending on changes in the external environment such as the load of the motor 15. As shown in FIG. 3, for example, when the load is small, after the target rotational speed is exceeded once, it gradually converges to the target rotational speed. On the other hand, when the load is large, the rotational speed gradually increases and converges to the target rotational speed.

  Next, the motor drive duty calculation unit 133 refers to the timing information counted by the timer 137, and is a predetermined time (the time until the motor 15 reaches the target rotational speed from the stop state and stabilizes, for example, 200 ms. When the time elapses, the average value of the duty values output by itself is obtained, and the obtained average duty value is output to the motor drive logic generation unit 134. As a result, the motor 15 rotates at a constant rotation speed. When time elapses, the vane of the variable nozzle hits the mechanical stopper, and the rotation speed of the motor 15 becomes zero. The motor drive duty calculation unit 133 stops outputting the duty value when the value of the motor rotation number output from the motor rotation number detection unit 136 becomes zero. Then, the motor drive duty calculation unit 133 reverses the rotation direction of the motor 15 and outputs the duty value until the vane of the variable nozzle hits the other mechanical stopper. At this time, the motor drive duty calculation unit 133 outputs the duty value until it hits the other mechanical stopper by the same operation as described above.

  In this manner, the motor rotation speed detection unit 136 for detecting the current motor rotation speed is provided, and the motor drive duty value is calculated by PI calculation in order to calculate the motor supply current necessary for maintaining the target rotation speed. After the motor rotation speed is stabilized, the constant rotation speed is maintained, so that the motor rotation speed can be kept constant even when the external environment of the electronic control actuator 13 changes. . As a result, the motor rotation speed immediately before the vane of the variable nozzle hits the mechanical stopper can be made constant, and even if the external environment during the initialization operation of the motor 15 differs for each initialization operation, the accurate stopper position (Fully open position and fully closed position) can be detected.

  In the above description, the example in which the drive control operation illustrated in FIG. 3 is performed during the initialization operation has been described. However, in the drive control operation illustrated in FIG. 3, the power of the variable nozzle control device is “ON”. It may be performed at any timing from the time until the power is turned off.

  2 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed, thereby executing variable nozzle control. Processing may be performed. The “computer system” here includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

  DESCRIPTION OF SYMBOLS 11 ... Engine ECU, 13 ... Electronic control actuator, 130 ... Microcomputer (microcomputer), 131 ... Angle signal conversion part, 132 ... Angle signal comparison part, 133 ... Motor drive Duty Arithmetic unit 134 ... Motor drive logic generation unit 135 ... Communication signal conversion unit 136 ... Motor rotation speed detection unit 137 ... Timer 138 ... Duty holding unit 14 ... Motor driver, 15 ... motor, 16 ... gear, 17 ... output shaft, 18 ... angle sensor, 19 ... lever, 20 ... rod, 21 ... vane operation piece

Claims (2)

Electronic control for controlling the opening degree of the vane of the variable nozzle by controlling the rotation angle of the rotating shaft of the motor based on a control signal from an engine control device that controls the driving of the engine equipped with the turbocharger having the variable nozzle. A variable nozzle control device for a turbocharger equipped with an actuator,
Motor rotation number detecting means for detecting the rotation number of the motor;
Supply current control means for controlling the amount of current supplied to the motor so that the rotation speed of the motor detected by the motor rotation speed detection means becomes a predetermined target rotation speed;
The supply current control means performs the initialization operation to obtain the current amount by the supply current control means until the target rotational speed is reached when obtaining the position where the vane of the variable nozzle hits the stopper. After the control reaches the target rotational speed, the rotational speed of the motor just before the vane of the variable nozzle hits the stopper is kept constant by keeping the current supplied to the motor constant. A variable nozzle control device for a turbocharger, characterized in that: In order to control the opening degree of the vane of the variable nozzle by controlling the rotation angle of the rotating shaft of the motor based on a control signal from an engine control device that controls the driving of an engine equipped with a turbocharger having a variable nozzle. A variable nozzle control program that operates on a variable nozzle control device of a turbocharger that includes an electronic control actuator that includes a motor rotation speed detection means for detecting the rotation speed of the motor,
Causing the computer to perform a supply current control step for controlling the amount of current supplied to the motor so that the rotation speed of the motor detected by the motor rotation speed detection means becomes a predetermined target rotation speed;
In the supply current control step, when the initialization operation is performed to obtain the position where the vane of the variable nozzle hits the stopper, the supply current control means sets the current amount until the target rotational speed is reached. After the control reaches the target rotational speed, the rotational speed of the motor just before the vane of the variable nozzle hits the stopper is kept constant by keeping the current supplied to the motor constant. A variable nozzle control program characterized by:

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