📚 Year 7 CAIE Engineering: Core Knowledge Points | 七年级CAIE工程：核心知识点梳理
Welcome to your Year 7 Engineering journey! This article gathers the essential knowledge you will explore: from the design cycle and workshop safety to materials, tools, electronics, and structures. Mastering these foundations will help you think like an engineer and build projects with confidence.
欢迎开启七年级工程学习之旅！本文梳理了你在这一年将接触的核心知识：从设计流程和车间安全到材料、工具、电子学及结构。掌握这些基础能帮助你像工程师一样思考，并自信地完成制作。
1. The Design Process | 设计过程
Engineering starts with a clear problem. You identify a need, then research existing solutions and users. This helps you write a design brief and specification before sketching ideas.
工程始于明确的问题。你要识别需求，研究现有解决方案和用户，然后在绘制草图前撰写设计摘要与规格说明。
After brainstorming, you develop a chosen idea with detailed drawings or CAD models. Prototyping allows you to test, evaluate and refine your design until it meets the specification.
头脑风暴后，你通过详图或CAD模型发展选定的方案。制作原型能让你测试、评估并改进设计，直到满足规格要求。
The process is cyclical: evaluation often leads back to development. In Year 7, you learn that failure is a valuable step, not an endpoint.
这个过程是循环的：评估往往会引导你返回开发阶段。在七年级，你会明白失败是有价值的一步，而不是终点。
2. Workshop Safety | 工作室安全
Always wear personal protective equipment (PPE). Safety goggles shield your eyes from dust and debris; sturdy shoes protect your feet from falling tools.
务必穿戴好个人防护装备。护目镜能阻挡灰尘和碎屑，结实的鞋子能保护双脚免受工具坠落伤害。
Long hair must be tied back and loose clothing tucked in before operating any machinery. Jewellery should be removed to prevent entanglement.
操作机器前必须束好长发并塞好宽松衣物。应取下首饰以免发生缠绕。
Keep your workspace tidy and return tools after use. Never run in a workshop and always listen to your teacher’s instructions before using unfamiliar equipment.
保持工作台整洁，用后归还工具。严禁在车间奔跑，使用陌生设备前务必听取老师指导。
3. Materials and Their Properties | 材料及其特性
Engineers classify materials into families: woods, metals, polymers and composites. Each has distinct properties such as hardness, toughness, strength and stiffness.
工程师将材料分类为木材、金属、聚合物和复合材料。每种材料都有独特的性质，如硬度、韧性、强度和刚度。
Hardness means resistance to scratches or dents; toughness is the ability to absorb energy without breaking. A material can be strong yet brittle, like glass.
硬度指抵抗划伤或凹陷的能力；韧性是吸收能量而不破裂的能力。一种材料可能坚固同时又很脆，比如玻璃。
Conductivity matters for electrical and thermal applications. Copper conducts electricity well, while plastics often serve as insulators in handles and casings.
导电性和导热性对电气与热能应用很重要。铜导电良好，而塑料常在握柄和外壳中充当绝缘体。
4. Measuring and Marking Out | 测量与划线
Accurate work begins with careful measuring. You will use a steel rule, tape measure and try square to transfer dimensions onto your material.
精确的加工始于细致的测量。你会用到钢直尺、卷尺和直角尺将尺寸转移到材料上。
Marking tools include a pencil for wood, a scriber for metal, and a marking knife for fine lines. Always mark waste areas so you cut on the correct side.
划线工具有木工铅笔、金属划线针以及划细线的划线刀。务必标记出废料区域，以便在正确的一侧进行切割。
Double-check every measurement twice: “measure twice, cut once” is a golden rule that saves material and time.
每次测量都要复核两遍：“两次测量，一次切割”这条黄金法则能节省材料和时间。
5. Hand Tools | 手工工具
Common cutting tools include the coping saw for curves, the hacksaw for metal, and the chisel for wood joints. Always clamp your work securely before cutting.
常用的切割工具有用于曲线的线锯、锯金属的钢锯和加工木接头的凿子。切割前一定要用夹具固定好工件。
Files smooth edges and remove sharp burrs. Use a flat file for flat surfaces and a half-round file for curved profiles. Clean the file teeth with a file card regularly.
锉刀能修光边缘并去除尖刺。平面用平锉，弧面用半圆锉。定期用钢丝刷清理锉齿。
Hammers and mallets drive nails or joints together. A ball-peen hammer is used with metal, while a wooden mallet won’t damage chisel handles.
锤子和木槌用于敲入钉子或拼接接头。球头锤适用于金属加工，木槌则不会损伤凿子柄。
6. Joining Methods | 连接方法
Joining parts is a core manufacturing skill. For wood, you might use PVA adhesive, screws or nails. A butt joint is simple, but a halving joint gives more gluing area.
连接零件是一项核心制造技能。对于木材，你可能会使用白乳胶、螺钉或钉子。对拼接合虽然简单，但半搭接能提供更大的胶合面积。
Pilot holes prevent wood from splitting when you insert screws. Countersinking allows the screw head to sit flush below the surface.
预先钻导孔可防止旋入螺钉时木材开裂。锪孔能让螺钉头部沉入表面之下。
In metalwork, you may encounter pop riveting, nuts and bolts, or soldering. Soldering melts a filler metal to create a strong electrical and mechanical bond.
在金属加工中，你会遇到抽芯铆接、螺栓螺母或钎焊。钎焊通过熔化填充金属，形成牢固的电气与机械连接。
7. Simple Mechanisms | 简单机械
Mechanisms change the size, direction or type of motion. A first-order lever has the fulcrum between the load and effort, like a pair of scissors.
机构能改变运动的大小、方向或形式。一级杠杆的支点在负载与施力之间，剪刀就是一例。
Practical formula for mechanical advantage:
机械优势实用公式：
Mechanical Advantage = Load (N) / Effort (N)
Gears transfer rotary motion; a small driver gear turning a larger driven gear increases torque while reducing speed. Pulleys redirect forces and can multiply lifting power through multiple rope sections.
齿轮传递旋转运动；小齿轮驱动大齿轮能增大转矩而降低转速。滑轮可改变力的方向，并通过多股绳索成倍放大提升力。
Bellows and linkages convert linear motion to rotational motion. You will model these systems with card or wood to understand how machines work.
连杆机构可将往复直线运动转换为旋转运动。你会用纸板或木料制作这些机构的模型，以理解机器如何工作。
8. Introduction to Electronics | 电子学入门
All circuits need a power supply, a load and a complete conducting path. A simple series circuit has one loop; if a bulb fails, the circuit breaks.
所有电路都需要电源、负载和完整的导电路径。简单的串联电路只有一个回路；如果灯泡坏了，整个电路就会断开。
The relationship between voltage, current and resistance is given by Ohm’s Law:
电压、电流与电阻之间的关系由欧姆定律给出：
V = I × R
Here V is voltage in volts, I is current in amperes, and R is resistance in ohms (Ω). A resistor with colour bands limits current, protecting components like LEDs.
其中V是电压，单位为伏特；I是电流，单位为安培；R是电阻，单位为欧姆（Ω）。带色环的电阻可限制电流，保护LED等元件。
You will build circuits using battery packs, wires, LEDs and switches on breadboards. Always check polarity: the longer leg of an LED connects to positive.
你将在面包板上用电池盒、导线、LED和开关搭建电路。注意检查极性：LED的长脚接正极。
9. Structures and Forces | 结构与力
Forces act on all structures. Tension pulls materials apart, compression squeezes them together, while bending, torsion and shear cause different types of deformation.
力作用于一切结构。拉力试图拉开材料，压力将它们压在一起，而弯曲、扭转和剪切则引起不同形式的变形。
Triangles are rigid shapes and are widely used in bridges and towers. A truss is a framework of triangles that spreads loads efficiently with less material.
三角形是刚性形状，被广泛用于桥梁和塔架。桁架是由多个三角形构成的框架，能以较少材料高效地分散荷载。
Beams reinforced with I-beams or hollow sections resist bending through high second moment of area. Understanding load paths helps engineers design safer buildings.
采用工字梁或中空截面加固的梁，由于截面惯性矩较大，能更好地抵抗弯曲。理解传力路径有助于工程师设计更安全的建筑。
10. Technical Drawing | 技术制图
Engineers communicate ideas through technical drawings. An orthographic projection shows the front, side and plan views of an object, aligned correctly.
工程师通过技术制图传达想法。正交投影正确对齐地展示物体的正面、侧面和平面视图。
Dimension lines, extension lines and leader lines must be neat and thin. All dimensions in millimetres (mm) do not need the “mm” symbol repeated for every number when stated in the title block.
尺寸线、延伸线和引线应当整洁纤细。在标题栏注明单位的情况下，所有以毫米为单位的尺寸无需每个数字后都重复标注“mm”。
Isometric drawing gives a 3D impression using three axes at 120°. You start with a vertical line, then draw two lines at 30° from the horizontal. Keep construction lines faint for guiding your outline.
等距草图通过三根120°相交的轴呈现出立体感。你先画一条竖线，然后以与水平方向成30°角画两条线。保留淡淡的辅助线以引导轮廓。
11. Engineering and Sustainability | 工程与可持续性
Materials have an environmental footprint. Life-cycle assessment considers extraction, manufacture, use and disposal. Reducing, reusing and recycling extend the life of resources.
每种材料都有环境足迹。生命周期评估考量提取、制造、使用和废弃处理各阶段。减少使用、重复使用和回收利用可延长资源寿命。
Choosing renewable materials like bamboo or FSC-certified timber helps protect forests. Designing for disassembly makes it easier to repair a product and recycle its parts.
选择竹材或FSC认证木材等可再生材料有助于保护森林。为拆解而设计能让产品更易维修且零件易于回收。
Energy-efficient circuits and machines also save resources. In your projects, try to minimise waste by planning your cutting layout carefully and reusing offcuts wherever possible.
节能电路与机器同样节约资源。在你的项目中，通过精心规划下料布局并尽可能利用废料，尝试将浪费降到最低。
Published by TutorHao | Engineering Revision Series | aleveler.com
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