The aluminum casing of the building intercom is an irregularly shaped structural component. Combining appearance and structural requirements, the core adopts a combination solution primarily based on CNC precision machining, supplemented by auxiliary processes.
1. Raw Material Preparation: 6061/6063 aluminum alloy sheets/profiles are selected (6063 focuses on aesthetic anodizing, 6061 on structural strength), and the blanks are obtained through sawing/shearing.
2. Blank Pre-treatment: Aging treatment eliminates internal stress to prevent deformation after machining; surface sandblasting/brushing pre-treatment improves adhesion for subsequent surface treatments.
3. CNC Machining: Three-axis/four-axis CNC machining centers are used to complete processes such as cavity milling, hole drilling and tapping, contour engraving, and chamfering, achieving the forming of complex internal cavities and assembly positions; for mass production, tooling fixtures (such as pneumatic fixtures) can be used to improve clamping efficiency and consistency.
4. Surface Treatment:
◦ Anodizing: The most mainstream process, achieving corrosion resistance, wear resistance, and color matching (such as silver-white, champagne gold). Some high-end products undergo hard anodizing to enhance surface hardness.
◦ Powder Coating/Baking Paint: For outdoor use, improving weather resistance and UV resistance. ◦ Passivation treatment: Simple protection, used for rust prevention on non-visual surfaces.
5. Post-processing and inspection: After deburring and cleaning, dimensions are measured using a 2D/3D measuring instrument, followed by assembly trial fitting and visual quality inspection.
For mass-produced standardized shells, die-casting can be used to form the blank first (reducing costs), followed by CNC precision machining to ensure critical dimensional accuracy; for thin-walled complex structures, full CNC machining is preferred.
The precision of the aluminum casing for building intercoms must match assembly and usage requirements. Key precision indicators are as follows:
1. Dimensional Accuracy:
◦ Critical assembly positions (e.g., screen mounting slots, circuit board positioning posts, screw holes): Tolerance controlled within ±0.05mm.
◦ Outline dimensions: Tolerance ±0.1mm, ensuring compatibility with building walls/panels.
◦ Hole coaxiality/positional accuracy: ≤0.08mm, ensuring smooth wiring and assembly.
2. Geometric Tolerances:
◦ Flatness: ≤0.1mm/100mm for the casing mounting surface, avoiding gaps.
◦ Perpendicularity: ≤0.05mm between the cavity sidewall and the mounting surface, ensuring the assembly accuracy of internal components.
3. Surface Accuracy:
◦ Surface roughness Ra1.6~3.2μm (after anodizing), non-surface surfaces Ra6.3μm is sufficient.
◦ Chamfer/corner radius tolerance ≤ 0.1mm, ensuring consistent feel and appearance.
Precision control relies heavily on the spindle accuracy (runout ≤ 0.005mm), tool accuracy, and fixture positioning accuracy of the CNC equipment. Regular equipment and measuring instruments need to be calibrated during mass production.
III. Industry Applications
Besides core applications in building intercom systems, the processing solutions and product characteristics of this type of aluminum housing can be extended to several security and smart building fields:
1. Smart Building Field:
◦ Housings for video intercom extensions/main units, access control card readers, and smart door lock panel bases.
◦ Housings for sensors in building automation systems (such as temperature, humidity, and infrared sensors).
2. Security Monitoring Field: Housings for small surveillance cameras, alarm controllers, and patrol machines, utilizing the heat dissipation and anti-interference properties of aluminum alloy to protect internal electronic components.
3. Smart Home Field: Housings for smart central control screens and whole-house smart control panels, adapting to the appearance and installation precision requirements of home scenarios.
4. Industrial Security Sector: Explosion-proof intercom terminal housings for factories/industrial parks (aluminum alloy processed to meet explosion-proof requirements), and parking lot gate control terminal housings.
The lightweight, corrosion-resistant, and electromagnetic shielding properties of aluminum alloy housings (aluminum reduces electromagnetic interference and protects internal circuit boards) make them the mainstream choice for security electronic equipment housings, especially with the continued growth in demand for intelligent upgrades in smart buildings and smart communities.
