(19) & (11) EP 2 189 639 A2 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: (51) Int Cl.: 26.05.2010 Bulletin 2010/21 F02D 23/02 (2006.01) F02D 41/22 (2006.01) F02B 37/12 (2006.01) (21) Application number: 09176515.6 (22) Date of filing: 19.11.2009 (84) Designated Contracting States: • Park, Seok Ryul AT BE BG CH CY CZ DE DK EE ES FI FR GB GR 363-883, Chungbuk (KR) HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL • Yoon, Sung Jong PT RO SE SI SK SM TR 369-821, Chungbuk (KR) Designated Extension States: • Chang, Sung Dong AL BA RS 440-200, Gyeonggi-do (KR) • Lim, Chae Hong (30) Priority: 20.11.2008 KR 20080115741 365-806, Chungcheongbuk-do (KR) • Kim, Tae Wan (71) Applicant: Kamtec Inc. 363-883, Chungbuk (KR) Jincheon-gun, Chungbuk 365-822 (KR) (74) Representative: Thinat, Michel (72) Inventors: Cabinet Weinstein • Lim, Chang Sik 56 A, rue du Faubourg Saint-Honoré 467-854, Gyeonggi-do (KR) 75008 Paris (FR) (54) Actuator in turbocharger of vehicle and method for controlling the same (57) Actuator (200) in a turbocharger of a vehicle and PWM signal to be applied to a motor (220) according to method for controlling the same is disclosed, in which a time for preventing an overcurrent from flowing to the position of a vane (202) is followed up in controlling a motor connected to the vane (202) of the turbocharger. EP 2 189 639 A2 Printed by Jouve, 75001 PARIS (FR) 1 EP 2 189 639 A2 2 Description having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. BACKGROUND OF THE DISCLOSURE The objectives and other advantages of the invention may be realized and attained by the structure particularly Field of the Disclosure 5 pointed out in the written description and claims hereof as well as the appended drawings. [0001] The present invention relates to an actuator in [0012] To achieve these objects and other advantages a turbocharger of a vehicle for preventing a motor which and in accordance with the purpose of the invention, as operates vane of the turbocharger in the vehicle from embodied and broadly described herein, an electronic burning due to an over-current and consequential mal- 10 actuator in a turbocharger of a vehicle includes an elec- function; and a method for controlling the same. tronic control unit provided to the vehicle, a microcom- puter for controlling operation of a vane of the turbocharg- Discussion of the Related Art er according to a PWM (Pulse Width Modulation) signal from the electronic control unit, and an actuator unit hav- [0002] The turbocharger in a diesel engine vehicle has 15 ing a motor of which operation is controlled by the PWM a gas turbine run by exhaust gas to operate a compressor signal from the microcomputer, wherein the microcom- directly connected thereto for compressing air that is puter forwards PWM signals different from one another pushed into the diesel engine to improve an engine out- to the motor for controlling an overcurrent. put. [0013] The microcomputer includes a variable duty [0003] The turbocharger is provided with the vane set 20 control unit for varying the PWM signal and forwarding to a reference air flow rate to be introduced thereto, and the PWM signal varied thus to the motor unit, and a fixed driven by a shaft connected to the motor. duty control unit for forwarding the PWM signal fixed with [0004] The motor, controlled by a control signal from respect to time. anengine ECU, is susceptible toburning and consequen- [0014] The actuator unit includes a position sensor for tial damage if a current to the motor increases over an 25 sensing a position of the vane. allowable limit of the motor to apply an over-current to [0015] In another aspect of the present invention, a the motor. method for controlling an electronic actuator in a turbo- [0005] The application of the over- current to the motor charger of a vehicle includes a target signal forwarding causes unstable operation of the turbocharger, failing to step for an electronic control unit to forward a PWM signal supply an adequate rate of air required for operation of 30 on a target position of a vane for making the vane of the the diesel engine. actuator in the turbocharger to position to the target po- sition, a vane position determining step for determining SUMMARY OF THE DISCLOSURE whether the vane is positioned at the target position or not at the present time, and a signal control step for de- [0006] Accordingly, the present invention is directed 35 termining that the present state is a normal state if the to an actuator in a turbocharger of a vehicle and a method vane is positioned at the target position, and if the vane for controlling the same. fails to position at the target position, controlling the PWM [0007] An object of the present invention is to provide signal being forwarded to the motor according to time. an actuator in a turbocharger of a vehicle and a method [0016] The signal control step includes the step of fol- for controlling the same, which enables normal operation 40 lowing up the present position of the vane and applying of a turbocharger vane. a current corresponding to a target signal (PWM) is ap- [0008] Another object of the present invention is to pro- plied to the motor. vide an actuator in a turbocharger of a vehicle and a [0017] The first control step includes the step of apply- method for controlling the same which can prevent a mo- ing an increased current to the motor for a t1 time period. tor of the actuator in a turbocharger from burning and 45 [0018] The first control step further includes an over- malfunction by an over-current. current control step for controlling the overcurrent to pre- [0009] Further object of the present invention is to pro- vent the overcurrent from being applied to the motor. vide an actuator in a turbocharger of a vehicle and a [0019] The overcurrent control step includes a second method for controlling the same which can make accu- control step for decreasing the current being applied to rate position control of vane in the turbocharger. 50 the motor for a t2 time period, and a third control step for [0010] Still further object of the present invention is to increasing the current being applied to the motor for a t3 provide an actuator in a turbocharger of a vehicle and a time period additionally after the second control step. method for controlling the same which can make stable [0020] The current applied in the second control step cutting off of an overcurrent without additional circuit for is decreased from the current applied in the first control cutting off the overcurrent. 55 step. [0011] Additional advantages, objects, and features of [0021] A current higher than the current applied in the the disclosure will be set forth in part in the description second control step is applied in the third control step. which follows and in part will become apparent to those [0022] A current fixed with respect to time is applied 2 3 EP 2 189 639 A2 4 to the motor in the second control step and the third con- turbocharger of a vehicle relates to a vane actuator in a trol step. turbocharger of a diesel vehicle having a turbocharger, [0023] In the second control step, a current, which can wherein the actuator includes a motor, and all peripheral maintain the present opening of the vane, is kept applied. components provided between the motor and the vane. [0024] The second and third control steps are repeated 5 The actuator is operated, electronically. after the first control step in an order only when the vane [0036] The vehicle has an electronic control unit ECU fails to position at the target position. 100 for controlling general matters required for operation [0025] The current applying time periods in the signal and running of the vehicle. control steps are in an order to t2>t1>t3. [0037] The electronic control unit 100 forwards a PWM [0026] It is to be understood that both the foregoing 10 signal on a target position of an actuator unit 200 to be general description and the following detailed description described later to a microcomputer 210 in the actuator of the present invention are exemplary and explanatory unit 200, and the microcomputer 210 forwards an oper- and are intended to provide further explanation of the ating signal to the motor 220 according to the PWM signal invention as claimed. received thus. That is, the signal from the electronic con- 15 trol unit 100 to the microcomputer 210 is a signal on a BRIEF DESCRIPTION OF THE DRAWINGS target position of the vane 202, the signal from the mi- crocomputer 210 to the motor 220 is a motor control sig- [0027] The accompanying drawings, which are includ- nal. ed to provide a further understanding of the disclosure [0038] The actuator unit 200 includes the microcom- and are incorporated in and constitute a part of this ap- 20 puter 210 MICOM, the motor 220, an H-bridge circuit plication, illustrate embodiment(s) of the disclosure and 230, a position sensor 240 and vane 202. together with the description serve to explain the principle [0039] The microcomputer 210 receives the PWM sig- of the disclosure. In the drawings: nal having a duty ratio from the electronic control unit [0028] FIG.