O desenvolvimento de um protótipo de panela de pressão elétrica requer usinagem CNC precisa para validar a racionalidade do projeto, funcionalidade de teste (por exemplo, vedação de pressão), e avaliar a aparência – etapas críticas antes da produção em massa. Ao contrário dos aparelhos de cozinha normais, electric pressure cookers have strict requirements for sealing performance e resistência estrutural, que moldam cada etapa do processo CNC. Este guia detalha todo o fluxo de trabalho, do design ao pós-processamento, com parâmetros-chave, material choices, and practical tips to ensure prototype success.
1. Preparação Preliminar: Projeto & Data Processing
The foundation of a high-quality prototype lies in accurate design and optimized data. This stage focuses on creating a detailed 3D model and preparing it for CNC machining.
(1) 3D Modeling with CAD Software
Use professional CAD tools (por exemplo, SolidWorks, UG) to design a model that reflects every critical detail of the electric pressure cooker. The model must include both external and internal structures, plus process features to simplify machining.
| Structure Category | Key Design Details | Requisitos de precisão | Propósito |
| External Structure | Lid (curved top), pot body (cylindrical shape), lidar (ergonomic grip), control buttons (凸起 height ≥2mm) | Lid-body alignment tolerance ±0.1mm; handle mounting hole position error ≤0.05mm | Ensure assembly accuracy; meet user ergonomics |
| Internal Structure | Sealing ring groove (width 5mm ±0.05mm), pressure valve mounting seat, sensor fixing holes | Sealing groove depth tolerance ±0.03mm; valve seat hole diameter error ≤0.02mm | Guarantee pressure tightness; fit internal components (por exemplo, sensores) |
| Process Features | Inclinação de calado (3°~5° on lid/pot body), rounding corners (R2mm on handle edges), parting lines | Draft slope ensures easy demolding; rounding prevents stress concentration | Simplify CNC machining; avoid prototype damage during testing |
(2) Model Repair & Format Conversion
Raw 3D models often have defects that can ruin machining—fix these issues before exporting:
- Defect Checking: Use software like Magics to identify broken surfaces, overlapping geometry, or missing features (por exemplo, incomplete sealing grooves).
- Repair Steps: Fill gaps, merge overlapping surfaces, and smooth uneven edges to ensure the model is “machinable.”
- Format Export: Convert the repaired model to Formato STL (the standard for CNC machining), with a mesh density of 0.1mm (balances detail and file size).
2. Seleção de Materiais & Processing Process Planning
Choosing the right materials and processes is critical—materials must mimic the performance of mass-produced parts, while processes need to balance precision and cost.
(1) Prototype Material Selection
Different components of the electric pressure cooker require materials with specific properties (por exemplo, resistência ao calor, resistência ao desgaste). Abaixo está uma comparação detalhada:
| Tipo de material | Applicable Parts | Propriedades principais | Machinability Tips | Tratamento de superfície |
| ABS | Pot body, lid (appearance parts), control button housings | Easy to mill, superfície lisa, baixo custo | Use high-speed spindle (10,000–15,000 rpm) para evitar derreter | Spray matte black paint (adhesion ≥4B standard) to simulate plastic texture |
| Nylon (PA) | Internal structural parts (por exemplo, suportes de sensores, pressure valve covers) | Alta resistência, resistência ao desgaste, resistência ao calor (até 120ºC) | Use ferramentas de metal duro; add cutting fluid to prevent overheating | No treatment needed (naturally wear-resistant) |
| Liga de alumínio (6061) | Metal handles, lid holders | Leve, alta rigidez, resistente à corrosão | Use high spindle speed (18,000–22,000 rpm) to reduce burrs | Anodização (silver-gray, 8–10μm thick) for anti-oxidation + trefilagem |
| Transparent Acrylic | Observation windows (if included) | Alta transmitância de luz (≥90%), clear appearance | Precision cutting with Φ3mm ball-head tool; avoid chipping edges | Polishing with abrasive paste (from coarse 400# to fine 1200#) |
(2) Core CNC Machining Processes
The process combination depends on the part’s shape and function. Below are the key processes and their applications:
| Process Name | Cenários de aplicação | Key Parameters & Pontas |
| Fresagem CNC | Pot body cavity (depth ≥80mm), lid curved surface, sealing ring groove | Usar “layered cutting” for deep cavities (0.5mm per layer); use ball-head tool for curved surfaces (Ra ≤1.6μm) |
| Torneamento CNC | Round components (por exemplo, pressure valve knobs, handle shafts) | Velocidade do fuso 20,000 rpm; taxa de alimentação 1,000 mm/min (ensures smooth surface) |
| Perfuração & Tocando | Sensor mounting holes (M4 threads), handle fixing holes | Drill Φ3.3mm bottom holes first, then tap (avoids thread stripping); use pecking drilling for deep holes |
| Fio EDM | Special-shaped parts (por exemplo, acrylic observation window frames) | Achieves accuracy ±0.02mm (critical for transparent, visible parts) |
3. Execução de Usinagem CNC: Etapas principais & Parameters
Precise execution is essential to avoid defects like poor sealing or structural weakness. Focus on programming, seleção de ferramentas, and process monitoring.
(1) Programação & Seleção de ferramentas
Use CAM software (por exemplo, Mastercam, PowerMill) to convert STL models into G-code, and select tools based on material and feature:
| Machining Stage | Tipo de ferramenta | Tool Size | Key Settings |
| Desbaste | Flat-bottom end mill | Φ10mm (ABS/nylon), Φ8mm (liga de alumínio) | Remove 90% de materiais; leave 0.3mm finishing allowance |
| Semi-Finishing | Ball-head end mill | Φ6mm | Smooth curved surfaces; reduce allowance to 0.1mm |
| Acabamento | Small ball-head end mill | Φ3mm (ABS/nylon), Φ2mm (acrílico) | Machine fine features (por exemplo, sealing grooves); achieve Ra ≤1.0μm |
| Perfuração | Twist drill | Φ2–Φ5mm | Pecking drilling (drill 3mm, retract 1mm) to clear chips |
(2) Machining Parameter Setting
Parameters vary by material to ensure quality and efficiency. Below is a practical reference:
| Material | Machining Stage | Velocidade do fuso (rpm) | Taxa de alimentação (mm/min) | Cutting Depth (milímetros) |
| ABS | Desbaste | 10,000–12,000 | 1,500–2,000 | 0.5–1.0 |
| ABS | Acabamento | 15,000–18,000 | 800–1,200 | 0.1–0,3 |
| Liga de alumínio | Desbaste | 12,000–15,000 | 1,200–1,800 | 0.5–0.8 |
| Liga de alumínio | Acabamento | 18,000–22,000 | 800–1,000 | 0.1–0.2 |
| Nylon | Desbaste | 8,000–10.000 | 1,000–1.500 | 0.4–0.8 |
| Nylon | Acabamento | 12,000–15,000 | 600–800 | 0.1–0.2 |
(3) Machining Process Monitoring
The first prototype (first piece) requires strict monitoring to catch issues early:
- Dimensional Checks: Pause after roughing to measure critical features (por exemplo, sealing groove width, lid-body gap) with calipers or a micrometer. Adjust the program if tolerance exceeds ±0.1mm.
- Surface Quality Checks: Inspect for tool marks, rebarbas, or melting (common in ABS/nylon). If tool marks are visible, increase spindle speed by 2,000 rpm.
- Clamping Stability: Ensure the part doesn’t shift during machining—use vacuum suction cups for flat parts (por exemplo, aluminum handles) or custom fixtures for curved parts (por exemplo, pot lids).
4. Pós-processamento & Teste Funcional
Post-processing enhances appearance and performance, while functional testing validates if the prototype meets design goals—especially critical for pressure cookers.
(1) Tratamento de superfície
Tailor the treatment to the part’s role and material:
| Part | Surface Treatment Steps | Expected Outcome |
| ABS Pot Body/Lid | 1. Grind with 600# → 1000# lixa (remove tool marks); 2. Spray primer (30μm de espessura); 3. Spray matte paint (50μm de espessura); 4. Oven cure at 60°C for 2 horas | Paint adhesion ≥4B; no peeling or fading |
| Aluminum Alloy Handle | 1. Degrease with isopropyl alcohol; 2. Anodize (form oxide film); 3. Hand-wire draw along the length | Uniform silver-gray color; sem arranhões |
| Acrylic Observation Window | 1. Polish with 400# abrasive paste (remove cutting marks); 2. Polish with 1200# paste (achieve transparency); 3. Clean with lens cleaner | Light transmittance ≥90%; sem defeitos visíveis |
(2) Teste Funcional
Assemble internal components (sealing ring, pressure valve, sensor) and simulate real usage:
| Test Type | Test Method | Pass Standard |
| Tightness Test | Fill the pot with 500ml water, close the lid, and pressurize to 100kPa (simulate working pressure). Hold for 30 minutos. | No water leakage; pressure drop ≤5kPa in 30 minutos |
| Button Feel Test | Press control buttons 1,000 vezes (2 presses/second). Measure stroke (2mm ±0.2mm) and feedback force (5–8N). | Consistent stroke and force; no button jamming |
| Structural Strength Test | Apply 5kg load to the lid (simulate accidental pressure). Hold for 10 minutos. | No deformation; lid-body gap remains ≤0.1mm |
| Heat Resistance Test | Heat the pot to 100°C (simulate cooking) and hold for 2 horas. Cool to room temperature. | No material warping; sealing groove tolerance remains ±0.05mm |
5. Inspeção & Otimização
Inspect critical dimensions and iterate on the design to fix defects—this ensures the prototype is ready for mold opening.
(1) Critical Dimension Inspection
Use um Máquina de medição por coordenadas (CMM) to check key dimensions:
- Lid-body mating gap: ±0,1 mm (ensures sealing)
- Sealing ring groove width: 5mm ±0.05mm (fits standard sealing rings)
- Threaded hole position (sensor mounting): ±0,05 mm (avoids assembly interference)
- Handle mounting hole alignment: ≤0,03 mm (ensures handle stability)
(2) Design Iteration & Otimização de custos
If defects are found (por exemplo, leakage, button jamming), modify the 3D model and reprocess. Use these tips to reduce costs:
- Split Complex Parts: Machine the lid and its holder separately instead of as one piece—cuts machining time by 30% and reduces tool wear.
- Use Hybrid Processes: 3D print small internal parts (por exemplo, pressure valve covers) with SLS nylon, then CNC machine appearance parts (por exemplo, pot body) with ABS—lowers material waste by 25%.
- Batch Machining: Para 10+ protótipos, use aluminum profile blanks (pre-cut to approximate size) instead of full blocks—reduces material removal by 40%.
Yigu Technology’s Perspective on Electric Pressure Cooker Prototype CNC Machining
Na tecnologia Yigu, we believe sealing performance and structural strength are the core of electric pressure cooker prototype machining. Many clients overspend by using high-cost materials for non-critical parts—e.g., aluminum alloy for internal brackets that only need nylon. Our team selects materials strategically: ABS for appearance parts (econômico, easy to finish) and nylon for internal structures (resistente ao calor, resistente ao desgaste). We also optimize machining for sealing: nosso “layered finishing” of sealing grooves ensures Ra ≤0.8μm, and we test tightness three times during production to avoid leakage. Para economia de custos, we use hybrid CNC + 3D printing and batch processing, cutting prototype costs by 20–30%. Our goal is to deliver prototypes that accurately validate design and function, accelerating clients’ path to mass production.
Perguntas frequentes
- Why is nylon (PA) used for internal structural parts instead of ABS?
Nylon has better heat resistance (até 120ºC) and wear resistance than ABS—critical for internal parts near heating elements or moving components (por exemplo, pressure valves). ABS melts at ~90°C and wears faster, making it unsuitable for parts that need to withstand high temperatures or repeated use.
- How do you ensure the lid and pot body have a tight seal after CNC machining?
We focus on two key steps: 1) Machining the sealing groove with a Φ3mm ball-head tool to achieve Ra ≤0.8μm (smooth surface reduces leakage risk); 2) Inspecting the lid-body gap with a CMM to ensure tolerance ±0.1mm. We also test tightness with 100kPa pressure—only prototypes with ≤5kPa pressure drop pass.
- How long does it take to CNC machine a single electric pressure cooker prototype?
Total time is ~4–6 days: 1 day for design/data processing, 1–2 days for CNC machining (varies by part complexity), 1 day for post-processing (painting/anodizing), and 1–2 days for assembly/functional testing. Batch production (10+ protótipos) can be shortened to 3–4 days with parallel processing.