Lesson plan for developing students' capacity in Technology subject for grades 11-20

Activity 3: Learn about the structure and working principle of the electric motor starting system.

a) Operational objectives

Through the pictures students can know the structure.

B1: Transfer of learning tasks

- Divide the class into 4 activity groups.

- Teacher: ask students to observe picture 30.1 (Textbook)

What parts does an electric motor starting system consist of?

. What power source does a DC motor use?

- Teacher explains: the shaft end of the rotor (7) of the electric motor has a spline structure to fit the spline joint with the hub of the one-way transmission joint (6).

. What are the characteristics of the transmission joint (6)?

. Why only match at startup?.

What parts does the control unit consist of?

. Observe figure 30.1 and comment on the positions of details (6) and (8) relative to each other before working.

. When starting the engine, what are the positions of (6) and (8)?

. Why does (6) match (8)?

. When the engine is running, does the starting system need to work?

. B2 : Carry out learning tasks

During group activities, teachers observe students studying on their own, discuss, and provide timely assistance when they need support.

B3: Report on learning task implementation results

- Group representatives report results.

Record the work results of individuals or groups of students.

B4 : Performance evaluation

Individual and group products.

Students agree on the answers and present them in their notebooks.

Activity 5 : Systematize knowledge

a) Operational objectives

Reinforce the key knowledge of the lesson to help students remember and deepen knowledge.

b) Suggestions for organizing activities

- Teachers guide students to summarize knowledge and write the main content in their notebooks at home.

c) Activity products: Individual products Students write down the key content and their notebooks.

I/ Tasks and classification:

1) Mission:

The starting system is responsible for rotating the engine crankshaft to a certain speed to start the engine.

2) Classification:

- Manual start

- Start with electric motor.

- Auxiliary motor starting system.

- Auxiliary engine starting system.

II/ Electric motor starting system:

1) Structure:

1. electric motor; 2. spring; 3. steel core; 4. drawbar; 5. lever; 6. transmission joint;

7. Rotor shaft of electric motor; 8. Flywheel of internal combustion engine;

9. Engine crankshaft.

2) Working principle:

- When starting: close the relay start key of the control unit to attract the steel core (3) to the left, through the pull rod (4) and lever (5) to make (6) slide on the spline shaft to engage with (8). At the same time, the electric motor is also energized  torque of

(7) transmitted through 96)  (8) rotates  engine crankshaft rotates.

- When working, the starter key is disconnected, the relay coil loses power, the spring (2) pushes the steel core from right to left, separating (6) from (8)  the starter motor does not rotate.

D. EXPANDED RESEARCH

Activity 6: Observe the structure of the starting system.

a) Operational objectives

help children understand more deeply about the importance of the starting system.

b) Suggestions for organizing activities

Divide the class into 4 groups to do homework and learn the following content:

-Compare the starting systems of some engines

c) Activity products: Individual and group products Students write down the key content and their notebooks.

3. Instructions

- Do homework for the topic

- Prepare new lessons at home

4. EXPERIENCE