Task 5.1 Starting System Inspection
Learning Preparation（学习准备）
Key terms: starting system Starter Clutch pinion gear Clamp Ammeter Relay vise
起动系统 起动机 离合器 主动齿轮 夹子，卡箍 电流表 继电器 虎钳
ห้องสมุดไป่ตู้
Tasks Introduction （任务导入）
Task 5.1 Starting System Inspection Task 5.2 Reading Charging Wiring Diagram Task 5.3 Lighting System Inspection Task 5.4 Wipers/Washer System Inspection Task 5.5 Audio and Visual System Inspection
5.1.1 Starting System
The starting system is a necessity for internal-combustion engines（内燃机）, because the Otto cycle （奥托循环） requires the pistons already to be in motion before the ignition phase of the cycle. This means that the engine must be started in motion by an outside force before it can power itself. Originally, a hand crank was used to start the engine, but it was inconvenient and rather hard work to crank the engine up to speed. It was also highly dangerous; when the engine did finally start up, the crank would begin to spin on its own at high speed. The operator had to pull away immediately or else risk a broken wrist.
Task Description（任务描述）
The automotive electric system is the most important support system of a modern car. Imagine your personal vehicle without an electric system. The gasoline engine would not run. Electricity provides the spark needed for combustion and the power needed for starting. The following tasks (e.g. starting system inspection, reading charging wiring diagram, lighting system inspection, etc.) are the important items in engine electric system service to ensure the engine running perfectly.
( ) 6. Turn off power to the circuit and break the circuit before measuring current. ( ) 7. Resistance hinders the flow of current. ( ) 8. The staring system converts mechanical energy into electrical energy. ( ) 9. The electrical energy is contained in the battery. ( ) 10. A considerable amount of mechanical power is necessary to start a car engine.
Plan and Implement（计划与实施）
Step 1 A maintenance case is provided; Step 2 Learn the process of starting system inspection via a maintenance manual; Step 3 Require students to grasp the key terms in this task; Step 4 Try to describe the process of inspecting starting system; Step 5 Students read relative material; Step 6 Assessment
Assessment and Feedback （评价与反馈）
True or False ( ) 1. If the clutch pinion gear is extended, replace the starter repair service kit. ( ) 2. The specified current of starter is 100A. ( ) 3. The starter rotates smoothly and steadily with the clutch pinion gear returned. ( ) 4. We’ll use an ohmmeter to check the continuity of starter relay. ( ) 5. When we inspect starter assembly, all tests must be performed within 3 to 5 seconds.
汽车实用英语
Unit 5
Electric System Service
Overall Objectives（总体目标）
Upon completion of this unit, you should be able to:
• Learn key terms about electric system in this unit. • Understand the service process of the main electric equipment. • Use maintenance manual to deal with the practical problems.