Electric heat thawing wrenches are critical tools for defrosting frozen bolts/nuts in industrial and automotive maintenance. Their prototypes, s'appuyer sur Usinage CNC to integrate structural precision and heating functionality, directly determine whether the final product meets efficiency and safety standards. This article systematically breaks down the full CNC machining process for electric heat thawing wrench prototypes, addressing core challenges like thermal insulation, heating uniformity, and structural durability.
1. Pré-masseur: Conception & Sélection des matériaux
A scientific design and appropriate material pairing lay the groundwork for a functional prototype. This stage focuses on balancing heating efficiency, force structurelle, et faisabilité de l'usinage.
1.1 Demand Analysis & 3D Modélisation
Clarifying functional and structural requirements first avoids costly rework during machining.
Demand Analysis Breakdown
| Requirement Type | Détails clés | Impact sur l'usinage CNC |
| Heating Function | Confirm target temperature range (40-80° C), vitesse de chauffage (≤5 mins to reach 60°C), and heating method (electric heating film/PTC heating sheet) | Determines the size and position of the heating element cavity (tolérance ± 0,05 mm) in the wrench head |
| Conception structurelle | Define wrench head size (Par exemple, 50mm×30mm for M16 bolts), longueur du manche (150-200mm for ergonomics), and grip texture | Influences toolpath planning (Par exemple, avoiding undercuts in the heating cavity; machining anti-slip textures with 0.2mm depth) |
| Normes de sécurité | Ensure handle surface temperature ≤45°C (anti-scalding); waterproof level ≥IPX4 (pour les environnements humides) | Requires precise machining of thermal insulation gaps (1-2mm between heating layer and handle) and sealed circuit cavities |
3D Modélisation & Engineering Drawing Tips
- Choix de logiciel: Utiliser Solide ou Et nx to create modular models—split the wrench into 3 core parts: wrench head (heating zone), poignée (insulation zone), et circuit cavity (temperature control zone) for step-by-step machining.
- Critical Design Notes:
- Reserve 0.5mm extra space in the heating element cavity to accommodate thermal expansion of the electric heating film.
- Conception honeycomb heat dissipation holes (diameter 3mm, spacing 8mm) in the handle to prevent overheating—ensure hole positioning accuracy (± 0,1 mm) for uniform airflow.
1.2 Material Comparison for Core Components
Material selection directly affects heating efficiency, durabilité, and machining difficulty.
| Composant | Optional Materials | Avantages | Désavantage | Machining Recommendations |
| Wrench Head (Heating Zone) | Alliage en aluminium (6061) | Excellente conductivité thermique (167 W / m · k), léger | Low corrosion resistance | Utiliser des outils en carbure; coolant required to reduce burrs |
| Acier inoxydable (304) | Résistance élevée à la corrosion, forte résistance | Mauvaise conductivité thermique (16 W / m · k) | Slow feed speed (80-120 mm / min) Pour éviter l'usure des outils | |
| Poignée (Insulation Zone) | Plastique d'ingénierie (PC) | Good insulation, résistance à la chaleur (Jusqu'à 120 ° C) | Low impact resistance | High-speed steel tools; compressed air cooling to prevent melting |
| Nylon 66 | Durcissement élevé, antidérapant | Faible résistance à la chaleur (≤80°C) | Terminer 800# sandpaper to smooth surface | |
| Thermal Insulation Layer | Silicone Pad (FDA-Certified) | Résistance à haute température (jusqu'à 200 ° C), bonne flexibilité | Low structural strength | Cut to size post-CNC; no machining required |
2. CNC Machining Stage: Installation & Execution
This stage transforms raw materials into precision components, requiring strict control over machine selection, toolpaths, et précision.
2.1 Machine-outil & Sélection d'outils
Matching machines and tools to component materials ensures efficiency and accuracy.
| Composant | Type de machine recommandé | Suitable Tools | Taille de l'outil (MM) | Objectif d'usinage |
| Aluminum Alloy Wrench Head | Centre d'usinage vertical (Par exemple, Dmg mori) | Flat Bottom Cutter (Brouillage), Ball Head Cutter (Finition) | Φ8-10 (Brouillage), Φ3-5 (Finition) | Machine heating cavity; bords de chanfrein (0.5MM) |
| Stainless Steel Wrench Head | High-Torque Machining Center | Tungsten Carbide End Mill | Φ6-8 | Cut heat dissipation grooves; ensure cavity flatness (≤0,1 mm) |
| PC Handle | 3-Axis CNC Engraving Machine (Par exemple, 3018 Pro) | Spiral End Mill | Φ4-6 | Machine grip texture; drill circuit cavity holes |
2.2 Programmation & Paramètres d'usinage
Optimized G-code and parameters prevent material damage and ensure precision.
Key Machining Parameters by Material
| Matériel | Rotational Speed (RPM) | Vitesse d'alimentation (mm / min) | Profondeur de coupe (MM) | Special Requirements |
| Alliage en aluminium (6061) | 8,000 – 12,000 | 150 – 250 | 1.0 – 1.5 | Use emulsion coolant; avoid high speed to prevent chip buildup |
| Acier inoxydable (304) | 5,000 – 8,000 | 80 – 120 | 0.5 – 1.0 | Apply cutting oil; reduce depth of cut to avoid tool breakage |
| Plastique PC | 10,000 – 15,000 | 200 – 300 | 0.8 – 1.2 | Compressed air cooling; pas de liquide de refroidissement (prevents material warping) |
Toolpath Optimization Tips
- Usinage brutal: For the wrench head’s heating cavity, Utiliser un zigzag toolpath to remove 90% of excess material—reduce machining time by 30% compared to linear paths.
- Finition: For the handle’s grip texture, Utiliser un spiral toolpath to ensure uniform groove depth (0.2mm ± 0,02 mm)—avoiding uneven pressure during use.
- Circuit Cavity: Utiliser un peck drilling cycle to machine holes (diameter 5mm) for wire routing—prevents chip clogging and ensures hole straightness.
2.3 Machining Precautions
- Fixation & Positionnement:
- Secure metal blanks with a vise + precision locating pins (tolérance ± 0,01 mm) to avoid vibration during machining.
- Fix plastic sheets with double-sided adhesive tape (résistant à haute température) to prevent surface scratches.
- Contrôle de précision:
- Maintain flatness tolerance ≤0.1mm for the wrench head’s heating cavity—ensures tight fit with the electric heating film.
- Contrôle tolérance de position du trou ±0,1 mm for the circuit cavity—avoids wire pinching during assembly.
3. Heating System Integration & Assemblée
Integrating heating elements and electronics turns components into a functional prototype.
3.1 Heating Element Installation
Proper installation ensures uniform heating and safety.
Two Common Heating Solutions (Comparaison)
| Solution | Installation Steps | Avantages | Désavantage |
| Electric Heating Film | 1. Clean the wrench head cavity with alcohol.2. Apply thermal conductive silicone grease (thickness 0.1mm) to the cavity.3. Paste the heating film (power density 1.5 W/cm²) and press for 5 min. | Fast installation, uniform heating | Low mechanical strength; easy to tear |
| PTC Heating Sheet | 1. Machine 4 fixing holes (diameter 2mm) around the cavity.2. Apply thermal grease to the PTC sheet.3. Secure the sheet with M2 screws (couple 0.2 N · m). | High durability, stable temperature | Heating uniformity depends on grease application |
3.2 Temperature Control System Integration
This system ensures safe and precise temperature regulation.
Component Selection & Câblage
| Composant | Model/Specification | Installation Notes |
| Temperature Sensor | NTC 10KΩ (± 1%) | Embed in the wrench head (1mm from heating element); seal with high-temperature glue |
| Contrôleur | PID Module (SSR Solid-State Relay) | Install in the handle’s circuit cavity; isolate from heating zone with silicone pad |
| Afficher | OLED Screen (128×64 pixels) | Mount on the handle; ensure 0.5mm gap for heat dissipation |
| Câblage | High-Temperature Silicone Wire (18AWG) | Route through pre-machined holes; wrap with fiberglass tape for insulation |
3.3 Assemblage étape par étape (Linear Narrative)
- Thermal Insulation Layer Installation: Paste the silicone pad (thickness 1mm) between the wrench head and handle—ensure no gaps to prevent heat transfer to the handle.
- Heating Element Connection: Solder the heating film/PTC sheet to the controller; test resistance (cible: 50-100Ω) to confirm no short circuits.
- Handle Assembly: Secure the handle to the wrench head with M3 screws (couple 0.3 N · m); add a waterproof rubber ring (diameter 8mm) at the joint to meet IPX4 standards.
- Final Checks: Verify all wires are neatly routed; ensure the display is aligned with the handle’s window (no offset >0.5mm).
4. Essai & Optimisation
Rigorous testing identifies issues, while optimization improves performance.
4.1 Key Test Items & Normes
| Catégorie de test | Méthode d'essai | Norme de réussite |
| Performances de chauffage | Set temperature to 60°C; use an infrared thermometer to measure 5 points on the wrench head | Temperature difference ≤±3°C; reach target in ≤5 mins |
| Contrôle de la température | Set temperature to 70°C; monitor for 1 hour with a data logger | Fluctuation ≤±1°C; auto-shutdown when exceeding 80°C |
| Sécurité | 1. Measure handle temperature after 1 hour of operation.2. Conduct IPX4 water splashing test | Handle temperature ≤45°C; no short circuits after splashing |
| Durabilité | Simulate 500 usages (chaque: heat to 60°C, cool to room temperature) | No loose parts; heating performance unchanged |
4.2 Optimization Directions
- Heating Uniformity: If temperature differences exceed 3°C, reapply thermal conductive grease (ensure even coverage) or adjust the heating film’s position.
- Handle Comfort: If grip texture is too rough, refinish with 1000# papier de verre; if too smooth, re-machine grooves (depth increased to 0.3mm).
- Réduction du poids: Machine 4 lightening holes (diameter 6mm) in the handle’s non-load-bearing area—reduce weight by 15% without affecting strength.
Point de vue de la technologie Yigu
For CNC machining of electric heat thawing wrench prototypes, thermal balance and safety are core. Yigu Technology suggests prioritizing material matching: alliage en aluminium 6061 for the wrench head ensures efficient heat transfer, while PC plastic for the handle guarantees anti-scalding. In machining, focus on the heating cavity’s flatness (≤0,1 mm)—even a tiny gap will reduce heating efficiency. Post-assembly, strict IPX4 testing is non-negotiable for wet workplaces. Regarder vers l'avenir, integrating IoT sensors (Par exemple, wireless temperature monitoring) will be a trend, requiring CNC machining to reserve space for tiny electronic modules—demanding tighter tolerances (± 0,03 mm) and micro-tool applications.
FAQ
- What CNC machine is best for machining the aluminum alloy wrench head’s heating cavity?
A vertical machining center (Par exemple, Dmg mori) est idéal. It offers high rigidity and precision (± 0,005 mm), ensuring the heating cavity’s flatness and size meet requirements—critical for tight fit with the heating element.
- How to prevent the PC handle from warping during CNC machining?
Use high rotational speeds (10,000-15,000 RPM) and moderate feed speeds (200-300 mm / min). En plus, use compressed air to cool the material continuously—avoids localized heat buildup that causes warping.
- Why is thermal conductive silicone grease necessary between the heating element and wrench head?
It fills tiny gaps (≤0,1 mm) between the two surfaces, reducing thermal resistance. Sans, air gaps would significantly lower heat transfer efficiency—leading to uneven heating and longer thawing times.