为了正常的体验网站,请在浏览器设置里面开启Javascript功能!

210电子节气门

2011-10-03 36页 pdf 1MB 31阅读

用户头像

is_682900

暂无简介

举报
210电子节气门 Electronic Power Control Design and Function Self-Study Programme 210 Service. 2 Please always refer to the relevant Service Literature for all inspection, adjustment and repair instructions. Service literature. The Self-Study Programme is not a Workshop ...
210电子节气门
Electronic Power Control Design and Function Self-Study Programme 210 Service. 2 Please always refer to the relevant Service Literature for all inspection, adjustment and repair instructions. Service literature. The Self-Study Programme is not a Workshop Manual. New Important Note With the Electronic Power Control system, the throttle valve is actuated only by an electric motor. This eliminates the need for a Bowden cable between the accelerator pedal and the throttle valve. It means that the driver input is relayed to the engine control unit via the accelerator pedal. The engine control unit then sends a correspond- ing command to the throttle valve positioner. By positioning the throttle valve, the engine con- trol unit can regulate engine torque even if the driver has not depressed the accelerator pedal. The result is better co-ordination between and within the engine management systems. We will now demonstrate that the Electronic Power Control is more than just a substitute for the Bowden accelerator cable. 3 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Throttle valve positioning . . . . . . . . . . . . . . . . . . . . . . . . 4 System description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Control process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 System design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 What happens and when? . . . . . . . . . . . . . . . . . . . . . . 8 System components . . . . . . . . . . . . . . . . . . . . . . . . . . 10 System overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 The engine control unit . . . . . . . . . . . . . . . . . . . . . . . . . 11 The accelerator pedal module . . . . . . . . . . . . . . . . . . 14 The throttle valve control unit . . . . . . . . . . . . . . . . . . . 16 The fault indicator lamp . . . . . . . . . . . . . . . . . . . . . . . . 22 Auxiliary signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Function diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Self-diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Test your knowledge . . . . . . . . . . . . . . . . . . . . . . . . . 30 Table of contents 4 Throttle valve positioning Mechanical throttle valve positioning system With this system, the driver depresses the accel- erator pedal and thus positions the throttle valve mechanically by means of a Bowden cable. When the driver depresses the accelerator pedal, the engine management system cannot control the position of the throttle valve. To regulate engine torque, the engine manage- ment system must refer to other controlled variables such as ignition timing and injection timing. Throttle valve positioning by an electric motor drive is only possible in the idling speed range and in combination with the Volkswagen cruise control system. Electric throttle valve positioning system With this system, the throttle valve is positioned by an electric motor across the full adjustment range. The driver depresses the accelerator pedal according to the engine power required. Senders register the accelerator pedal position and relay this information to the engine control unit. The engine control unit now sends a signal corre- sponding to the driver input to the throttle valve positioner which in turn sets the throttle valve to the appropriate angle. If the engine torque has to be adjusted for rea- sons of safety or fuel consumption, however, the engine control unit can adjust the position of the throttle valve independent of the accelerator pedal position. The advantage of this is that the control unit defines the position of the throttle valve according to the various individual requirements (driver input, exhaust emissions, fuel consump- tion and safety). Introduction 210_007210_008 5 System description Engine torque control with mechanical throttle valve positioning The various torque requirements are signalled individually to the engine control unit and then processed. The torque demands cannot be matched opti- mally because the engine control unit cannot access the mechanically adjustable throttle valve directly. Engine torque control with electric throttle valve positioning This system permits torque-oriented engine management. What does this mean? First, the engine control unit gathers all the internal and external torque demands. Then it calculates the necessary control actions. This system is more precise and efficient than the previous system. Internal torque demands include: - Start - Catalytic converter heating - Idle speed control - Power limitation - Speed limiting device - Lambda control External torque demands originate from: - the automatic gearbox (shift point) - the brake system (Traction Control System, engine braking control) - the air conditioning system (air conditioner compressor ON/OFF) and - the cruise control system Internal requirements External requirements Optimal efficiency 210_009 The "tools“ which the engine management system uses to influence the engine torque are: throttle valve, charge pressure, injection timing, cylinder suppression and ignition advance angle. Engine control unit 6 Introduction Control process With the first line of approach, the system acti- vates the controlled variables that affect charge. These variables are also known as controlled variables for long-term torque demand. They are: - throttle valve angle and - charge pressure (turbocharged engines). With the second line of approach, the system changes the controlled variables that affect short-term torque independent of charge. They are: - ignition point, - injection time and - cylinder suppression. Specific torque Actual torqueAir flow rate 1st line of approach 2nd line of approach Ignition, fuel injection Engine control unit 210_010 The engine management system generates a specific torque according to the external and internal torque demands. Actual torque is calculated from the following factors: engine speed, load signal and ignition advance angle. The system pursues two lines of approach simultaneously. The engine control unit initially compares the actual torque and the specified torque. If these two values differ from one another, the system determines the corrective action necessary to make these values match. On the following pages, we will show you how the electric throttle valve positioning function works. 7 System design The accelerator pedal module determines the current accelerator pedal position with its senders and sends a corresponding signal to the engine control unit. The engine control unit calculates from this signal how much engine power is required by the driver and converts this information into an engine torque value. For this purpose, the engine control unit activates the throttle valve drive in order to open or close the throttle valve further. When activating the throttle valve drive, the engine control unit makes allow- ance for additional engine torque demand factors such as air-conditioning. In addition, it monitors the "Electronic Power Control” function. The throttle valve control unit is responsible for providing the required air mass flow. The throttle valve drive actuates the throttle valve in accordance with the instructions issued by the engine control unit. The throttle valve angle senders supply the engine control unit with feedback on the position of the throttle valve. The fault indicator lamp for Electronic Power Control indicates to the driver that there is a fault in the Electronic Power Control system. Electronic Power Control comprises: - the accelerator pedal module together with the accelerator position senders, - the engine control unit, - the throttle valve control unit, and - the fault indicator lamp for Electronic Power Control. Throttle valve control unit Accelerator pedal module Fault indicator lamp Auxiliary signals 210_011 8 Introduction What happens and when? In idling mode The engine control unit can recognise from the signal voltages of the accelerator position sender that the accelerator pedal is not depressed. The idle speed control process now commences. The digital idling stabilisation function also supports the idle speed control process. Engine control unit Accelerator pedal module Angle sender for throttle valve drive Accelerator position sender Throttle valve control unit The two angle senders for throttle valve drive sig- nal the current position of the throttle valve to the engine control unit. They are located in the throttle valve control unit. Throttle valve drive The engine control unit activates the throttle valve drive and positions the throttle valve by means of an electric motor. The throttle valve is opened or closed further depending on the extent to which the actual idling speed deviates from the specified idling speed. 210_019 210_060 210_061 9 Pressing the accelerator pedal The engine control unit can recognise from the signal voltages of the accelerator position sender the extent to which the accelerator pedal is depressed. Using this information, the engine control unit calculates the driver input and posi- tions the throttle valve by actuating the throttle valve drive by means of an electric motor. The engine control unit also controls the ignition timing, the injection timing and, if necessary, the charge pressure. The engine control unit makes allowance for additional engine torque demand factors when calculating the necessary throttle valve position. These include: - the speed limiting device - the cruise control system - the Traction Control System (TCS) and - the engine braking control (EBC) When engine torque is required, the throttle valve can be adjusted even if the driver has not changed the accelerator pedal position. The two angle senders for throttle valve drive determine the throttle valve position and send a corresponding signal to the engine control unit 210_021 210_062 210_063 TC Air EBC 10 System overview System components Sensors Actuators Brake light switch F and brake pedal switch F47 Clutch pedal switch F36 Accelerator pedal module with accelerator pedal position sender -1- G79 and accelerator pedal position sender -2- G185 Throttle valve control unit J338 angle sender 1 for throttle valve drive G187 and angle sender 2 for throttle valve drive G188 Fault indicator lamp for electric throttle control K132 (Electronic Power Control) Throttle valve drive G186 Engine control unit J... Diagnostic connection Throttle valve control unit J338 with 210_037 Auxiliary signals from: - automatic gearbox, - brake system, - air conditioning system, - cruise control system, and others The system components may be different to those shown in this overview depending on vehicle equipment specification. 11 Engine control unit J... Design Put in simple terms, the engine control unit com- prises two processing units: the function processor and the watchdog processor. - The function processor receives the signals from the sensors, processes them and then activates the actuators. The function processor also checks the watchdog processor. - The watchdog processor serves only to check the function processor. Function processor Watchdog processor 210_012 210_031 Its tasks in the Electronic Power Control: The EPC calculates from the input signal supplied by the accelerator position sender how much engine power the driver requires and converts this information into an engine torque by means of the actuators. The engine control unit makes allowance for additional functions of the engine management system (e.g. engine speed limitation, road speed limitation and power limitation) and other vehicle systems (e.g. the brake system or the automatic gearbox). The engine control unit also monitors the "Electronic Power Control“ system in order to prevent malfunctions occurring. 12 System components Monitoring function The watchdog processor continuously monitors the functions of the function processor. At the same time, it checks the output signals of the function processor against its own calcula- tions. The function processor and the watchdog processor check each other by means of a query & answer function. If faults are found, both processors can influence the throttle valve control unit, the ignition and the injection independently from one another in order to shut down the engine. checks output signals calculates corrective actions A ct ua to rs Se ns or s Output signal Output signal Function processor Watchdog processor The watchdog processor checks the function processor with the query & answer function. Error counter qu er ie s a ns w er s The watchdog processor queries the function processor with regard to, say, engine speed or ignition advance angle. Then it checks whether the answer is correct. If a wrong answer is given, the error counter of the watchdog processor is incremented. The engine is shut down after five wrong answers. Five wrong answers can be detected in less than a half second. 210_014 210_013 A ct ua to rs Se ns or s Function processor Watchdog processor Engine is shut down if necessary 13 The function processor checks the watchdog processor The function processor gives no answer or gives an answer at the wrong point in time To monitor the watchdog processor, the function processor deliberately gives a wrong answer. If the watchdog processor recognises the wrong answer, this error is registered in the error coun- ter and returned to the function processor. If the watchdog processor does not recognise the wrong answer, the error counter of the function processor is incremented. The engine is shut down after the watchdog counter fails to recognise five wrong answers. In this case, the engine is shut down immediately. qu er ie s gi ve s w ro ng a ns w er Function processor Watchdog processor se nd s co un t Function processor Watchdog processor no answer 210_015 210_016 qu er ie s A ct ua to rs Se ns or s A ct ua to rs Se ns or s 14 System components The accelerator pedal module comprises - the accelerator pedal, - accelerator pedal position sender -1- G79 and - accelerator pedal position sender -2- G185 Two senders are used to ensure maximum safety. This system configuration is also known as a "redundant system". Redundant literally means "superfluous". In tech- nical terms, there is redundancy when, for instance, an item of information occurs more often than is required for system operation. Open housing on accelerator pedal module showing senders G79 and G185. Signal utilisation The engine control unit is able to recognise the current position of the accelerator pedal from the signals supplied by the two accelerator position senders. The two senders are sliding contact potentiome- ters and are mounted on a common shaft. The resistances of the sliding contact potentiome- ters and the voltages transmitted to the engine control unit vary with each change in the accelerator pedal position. The signal voltages are indicative of kick-down and idling speed. The idling speed switch F60 in the throttle valve control unit is no longer required. Sliding contact path Sender Accelerator pedal position sender -2- Accelerator pedal position sender -1- 210_039 210_064 210_002A 15 Electrical circuit A voltage of 5 volts is present at both sliding con- tact potentiometers. For safety reasons, each sensor has its own voltage supply (red), its own earth connection (brown) and its own signal wire (green). A series-type resistor is fitted in sender G185. As a result, two different characteristics are obtained for the two senders. This is a prerequi- site for the safety and test functions. The signal from the sender is read out in percent on the associated measured value block. Hence, 100% = 5 volts. G79 G185 R [Ω] G79 s[m] G185 The following happens when both senders fail: An entry is made in the fault memory and the fault indicator lamp for Electronic Power Control is activated. - The engine runs at a higher idling speed (max. 1500 rpm) only and no longer responds to the accelerator. Effects of signal failure The following happens when one sender fails: - An entry is made in the fault memory and the fault indicator lamp for electrical throttle control is activated. - The system initially activates the idling mode. If the second sender is found to be in the idling speed position within a defined test period, vehicle operation is resumed. - If full throttle is desired, the engine speed is increased slowly. - The idling speed is also registered via the brake light switch F or brake pedal switch F47. - The convenience functions, e.g. cruise control system or engine braking moment control, are deactivated. 210_046 210_052 Simultaneous failure of both senders may not be identified properly depend- ing on the engine management system. - The fault indicator lamp is not activated. - The engine runs at a higher idling speed and no longer responds to the accelerator. 16 System components The throttle valve control unit J338 is located on the intake manifold. It ensures that the engine is provided with the required air flow. Design It comprises - the throttle body, - the throttle valve, - throttle valve drive G186, Throttle body Throttle valve drive Housing cover with integrated electronics Gear wheel with spring return systemThrottle valve Do not open or repair the throttle valve control unit. The basic setting procedure must be performed after replacing the throttle valve control unit. - angle sender 1 for throttle valve drive G187 and - angle sender 2 for throttle valve drive G188. Angle senders 1+2 for throttle valve drive 210_006 17 Function To open or close the throttle valve, the engine control unit activates the electric motor for throt- tle valve drive. The two angle senders provide the engine control unit with feedback on the current position of the throttle valve. For safety reasons, two senders are used. Electrical circuit Both angle senders have a common voltage supply (red) and earth wire (brown). Each of the two senders has its own signal wire (green). The throttle valve drive (blue) is activated depending on the direction of movement. Drive Throttle valve Angle senders 1+2 for throttle valve drive J338 G187 G188 G186 Engine control unit 210_041 210_051 18 System components Throttle valve drive G186 The throttle valve drive is an electric motor and is activated by the engine control unit. The throttle valve drive operates the throttle valve by means of a small gear. The throttle valve can be positioned in infinitely variable steps between the idling position and the full-throttle position. Throttle valve position - The lower mechanical stop In this position, the throttle valve is closed. It is required for the basic adjustment of the throttle valve control unit. - The lower electrical stop is defined in the engine control unit and is located just above the lower mechanical stop. During operation, the throttle valve is closed no further than the lower electrical stop. This prevents the throttle valve from intruding into the housing. Throttle valve drive as shown at the housing cover of the throttle valve control unit. Throttle valve drive Gear Throttle valve Return spring Throttle valve control unit housing 210_028 210_065 Engine control unit 210_023 19 -
/
本文档为【210电子节气门】,请使用软件OFFICE或WPS软件打开。作品中的文字与图均可以修改和编辑, 图片更改请在作品中右键图片并更换,文字修改请直接点击文字进行修改,也可以新增和删除文档中的内容。
[版权声明] 本站所有资料为用户分享产生,若发现您的权利被侵害,请联系客服邮件isharekefu@iask.cn,我们尽快处理。 本作品所展示的图片、画像、字体、音乐的版权可能需版权方额外授权,请谨慎使用。 网站提供的党政主题相关内容(国旗、国徽、党徽..)目的在于配合国家政策宣传,仅限个人学习分享使用,禁止用于任何广告和商用目的。

历史搜索

    清空历史搜索