📚 Year 9 WJEC Engineering: Case Study Practical Exercises | 九年级WJEC工程：案例分析实战演练
In Year 9 WJEC Engineering, case study analysis is more than just reading about products — it is a hands-on method for understanding how everyday objects are designed, manufactured and evaluated. Through practical exercises, you will learn to dissect products, explore material choices, examine production methods and propose real improvements. This article will guide you through a structured approach to conducting your own engineering case studies, from selecting an item to presenting your final report.
在九年级WJEC工程课中，案例分析不仅仅是阅读产品资料——它是一种通过动手实践来理解日常物品如何被设计、制造和评估的方法。通过实战练习，你将学会拆解产品、探索材料选择、审视生产方法并提出真实的改进建议。本文将带你走完一套结构化的工程案例研究流程，从挑选一个物品到撰写最终报告。
1. What Is an Engineering Case Study? | 什么是工程案例研究？
An engineering case study is a detailed investigation of a specific product, system or process. It involves reverse engineering, analysing functions, identifying materials and manufacturing methods, and evaluating how well the design meets user needs and environmental constraints. For Year 9 learners, it turns theory into tangible understanding.
工程案例研究是对某个具体产品、系统或流程的详细调查。它涉及逆向工程、功能分析、识别材料与制造方法，并评估设计在多大程度上满足了用户需求与环境限制。对九年级学生而言，它把理论变成了看得见摸得着的理解。
The WJEC curriculum expects you to develop skills in observation, measurement, sketching and critical thinking. A well-chosen case study — such as a simple mechanical toy or a kitchen utensil — allows you to practise these skills while building portfolio evidence that demonstrates your ability to think like an engineer.
WJEC课程要求你培养观察、测量、素描和批判性思维技能。一个选择得当的案例——比如一个简单的机械玩具或厨具——能让你在练习这些技能的同时，积累能展示你工程思维能力的档案证据。
2. Choosing a Suitable Product for Analysis | 选择合适的产品进行分析
Start with a product that has no more than 8–12 components, uses multiple materials, and combines at least two simple mechanisms. Good examples include a retractable pen, a clothes peg, a bicycle bell, a wind-up torch or a can opener. Avoid items with complex electronics or sealed assemblies at this stage.
从零件数不超过8–12个、使用多种材料并至少结合两种简单机构的产品入手。好例子包括伸缩圆珠笔、晾衣夹、自行车铃、手摇电筒或开罐器。现阶段要避免复杂电路或一体成型无法拆解的物品。
Always seek permission before disassembling any device, and ensure it is safe to handle — no sharp edges, no mains voltage and no hazardous substances. Document the original appearance with photographs and basic measurements before you begin any disassembly.
在拆解任何装置之前一定要征得许可，并确保操作安全——没有锋利边缘、不使用市电、没有有害物质。在开始拆解前，先用照片和基本尺寸记录原始外观。
3. The Reverse Engineering Workflow | 逆向工程工作流程
Reverse engineering is the backbone of a case study. You systematically take a product apart, record every component, and deduce its function. The typical workflow includes: visual inspection, function analysis, disassembly, component listing, material identification, dimensional measurement and reassembly (if possible).
逆向工程是案例研究的主干。你系统地拆解产品，记录每一个零件，并推断其功能。典型流程包括：外观检查、功能分析、拆解、零件清单、材料识别、尺寸测量和重新组装（如可能）。
Keep a numbered list of each component along with its mass, material and a sketch. A simple table with columns for 'Part', 'Material', 'Function' and 'Quantity' will help you stay organised. This methodical approach is highly valued in WJEC coursework.
为每个零件编号并记下它的质量、材料和草图。一张简单的表格，列出'零件'、'材料'、'功能'和'数量'等列，能帮你保持条理。这种有条不紊的方法在WJEC课业中备受重视。
4. Materials and Their Properties | 材料及其属性
Identifying materials correctly is a key assessment objective. Use simple tests where possible: a magnet for ferrous metals, a density/float test for plastics, and visual inspection for grain structure in wood. Note properties such as hardness, flexibility, conductivity and resistance to corrosion.
正确识别材料是一个关键的评估目标。尽可能使用简单测试：用磁铁检测铁金属，用密度/浮力测试区分塑料，用肉眼观察木材纹理。记录硬度、柔韧性、导电性和耐腐蚀性等属性。
For a bicycle bell, the dome might be pressed steel — chosen for acoustic resonance and durability. The lever could be injection-moulded ABS for toughness. Linking material choice to functional requirements is a skill that elevates your analysis.
以自行车铃为例，铃盖可能是冲压钢——因其声学共振和耐久性而选用。拨杆可能是注塑成型的ABS，取其韧性。将材料选择与功能需求挂钩，是能让你的分析更上一层楼的技能。
5. Manufacturing Processes in Everyday Products | 日常产品中的制造工艺
Once materials are known, investigate how each component was made. Common processes include injection moulding for plastic parts, stamping or pressing for sheet metal, die casting for complex metal shapes, and turning or milling for shafts and pins. Look for mould lines, ejector pin marks and parting lines as clues.
知道材料后，研究每个零件是如何制成的。常见工艺有塑料件的注塑成型、金属薄板的冲压、复杂金属件的压铸，以及轴销类的车削或铣削。寻找分模线、顶针痕迹和合模线作为线索。
Explain why a particular process was chosen. For instance, a retractable pen barrel is injection moulded because the process can produce high volumes of consistent, lightweight parts at low unit cost. A metal spring is coil-wound from wire to provide reliable elastic return.
解释为什么选择某种工艺。例如，伸缩圆珠笔的笔杆采用注塑成型，因为该工艺能以低单位成本大批量生产出尺寸一致、轻巧的零件。金属弹簧则用线材卷绕而成，以提供可靠的弹性回位。
6. Analysing Design Constraints and User Needs | 分析设计约束与用户需求
Every engineered product is shaped by constraints: ergonomics, safety, cost, weight, durability, aesthetics and regulations. For a wind-up torch, the design must allow a comfortable grip, generate enough voltage with a small crank, and survive being dropped. User needs include one-handed operation and a long lifespan of the plastic gears.
每个工程产品都受到设计约束的塑造：人机工程学、安全性、成本、重量、耐久性、美学和法规。对手摇电筒来说，设计必须保证握持舒适、用一个小摇柄就能产生足够电压，并能耐受跌落。用户需求包括单手操作和塑料齿轮的长寿命。
Create a simple design specification for your chosen product by listing must-haves and nice-to-haves. Then compare the actual product against that specification, noting where it excels and where it falls short. This is the core of evaluative commentary.
为你选定的产品创建一份简单的设计规范，列出必须满足的要求和锦上添花的要求。然后将实际产品与该规范进行对比，标注其擅长之处与不足之处。这正是评估性评述的核心。
7. Cost, Efficiency and Value Engineering | 成本、效率与价值工程
Engineers must balance performance with affordability. In your case study, estimate the number of parts, the likely batch size, and the relative cost of materials. A product with fewer parts, standard fasteners and snap-fit assemblies is usually cheaper to make and easier to recycle.
工程师必须在性能与可负担性之间取得平衡。在你的案例研究中，估算零件数量、可能的批量大小和材料的相对成本。零件少、使用标准紧固件和卡扣式装配的产品通常制造成本更低，也更易于回收。
Value engineering is the process of improving the value of a product by either reducing cost without sacrificing function, or enhancing function without increasing cost. Propose one value-engineering change for your analysed product — for example, replacing a machined brass bush with a self-lubricating polymer to cut weight and cost.
价值工程是提高产品价值的过程，要么在不牺牲功能的前提下降低成本，要么在不增加成本的情况下增强功能。为你分析的产品提出一项价值工程改进——例如，用自润滑聚合物替代机加工的铜套，以减轻重量并降低成本。
8. Sustainability and Lifecycle Thinking | 可持续性与生命周期思考
Sustainability is now a central theme in engineering. Examine the product's lifecycle: raw material extraction, manufacturing, transport, use, and end-of-life disposal or recycling. Count how many different materials are used and whether they can be easily separated for recycling.
可持续性现在是工程领域的核心主题。考查产品的生命周期：原材料开采、制造、运输、使用，以及末端废弃处置或回收。数一数使用了多少种不同材料，以及它们能否被轻松拆解分拣以进行回收。
For a clothes peg, a one-piece moulded design using polypropylene may be more sustainable than a two-part wooden peg with a steel spring, as it reduces material separation effort. Discuss whether the product could be designed for disassembly or made from biodegradable or recycled materials.
以晾衣夹为例，使用聚丙烯的一体成型设计可能比带有钢制弹簧的两片式木夹更具可持续性，因为它减少了材料分拣的工作量。探讨该产品能否被设计为可拆卸结构，或是否可以采用生物降解或再生材料制造。
9. Practical Disassembly and Documentation | 拆解实操与文档记录
Set up a clean, well-lit workspace with a camera, a notepad, basic hand tools and a white tray to catch small parts. Photograph the product before, during and after disassembly. Record every step so that you could write a reassembly procedure later — this demonstrates true engineering communication.
布置一个干净、光线充足的工作区，准备好相机、笔记本、基本手工具和一个白色托盘来接住小零件。拍摄拆解前、中、后的产品照片。记录每一步，以便你之后能写出重新组装步骤——这展示的是真正的工程沟通能力。
Draw an exploded diagram (by hand or using simple CAD) that shows the spatial relationship of all components. Label each part with its name and material. Exploded views are extremely powerful in portfolio work because they summarise the whole product architecture at a glance.
画一张分解图（手绘或用简单CAD），展示所有零件之间的空间关系。为每个部件标注名称和材料。在档案作品中，分解图极具表现力，因为它让整个产品的结构一目了然。
10. Proposing Design Improvements | 提出设计改进
Analysis without improvement is incomplete. Based on your findings, suggest at least three realistic modifications. They could address ergonomics, durability, sustainability, ease of assembly or user experience. For each suggestion, provide a brief justification rooted in evidence from your investigation.
没有改进建议的分析是不完整的。根据你的发现，至少提出三项切合实际的修改方案。它们可以针对人机工程、耐久性、可持续性、装配方便性或用户体验。每项建议都要基于你调查中得到的证据给出简要理由。
For example, after studying a clothes peg, you might recommend adding a non-slip grip pad to the jaws to hold heavier fabrics better, or redesigning the pivot to use a living hinge to eliminate the steel spring. Sketch your proposed changes and explain how they would be manufactured.
例如，研究过晾衣夹后，你可能会建议在夹口添加防滑垫片以更好地夹持厚重织物，或者重新设计枢轴采用一体式活铰链来省去钢弹簧。画出你的改进草图，并说明怎样制造这些改进。
11. Structuring Your Case Study Report | 搭建案例研究报告的结构
A professional case study report should follow a logical structure: title page, introduction, product overview, disassembly procedure, component inventory (table), materials and manufacturing analysis, constraints and user needs, sustainability assessment, proposed improvements, and a conclusion. Use clear headings and append photographs and drawings.
一份专业的案例研究报告应遵循逻辑结构：扉页、引言、产品概览、拆解步骤、零件清单（表格）、材料与制造分析、约束与用户需求、可持续性评估、改进建议和结论。使用明确的标题，并附上照片和图纸。
In WJEC engineering, your report is not just a diary of what you did — it is evidence of your ability to apply theoretical knowledge to a real-world context. Every claim about a material or process should be supported with a reason, and every measurement should include units and tolerances where appropriate.
在WJEC工程学中，你的报告不只是一篇做了什么的活动记录——它是你能将理论知识应用于真实情境的证据。任何关于材料或工艺的论断都应有理由支撑，每个测量数据都应包含单位，并在适当情况下注明公差。
12. Assessment Criteria and Key Skills | 评估标准与关键技能
Year 9 WJEC case study tasks are usually assessed against criteria such as: ability to identify engineering information, quality of observation and recording, use of technical vocabulary, linking properties to manufacturing processes, evaluation of a product's performance, and clarity of communication. Check your specification carefully.
九年级WJEC案例研究任务通常依据如下标准评估：识别工程信息的能力、观察与记录的质量、技术词汇的使用、将属性与制造工艺联系起来、对产品性能的评估，以及沟通表达的清晰度。仔细对照你的课程规范。
Key skills you will develop include systematic dismantling, accurate measurement (using vernier calipers or a ruler), material testing, observational sketching, and concise report writing. These are exactly the skills that GCSE Engineering and advanced vocational courses build upon, so mastering them now gives you a strong advantage.
你将发展的关键技能包括系统化拆解、精确测量（使用游标卡尺或直尺）、材料测试、观察速写和简明报告撰写。这些正是GCSE工程学及高级职业课程所依托的技能，因此现在就掌握它们会带给你显著的优势。
Published by TutorHao | Engineering Revision Series | aleveler.com
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