Uses for Rivets in CNC Manufacturing(acetal plastic Alice)
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- source:WEINBERG CNC Machining
In computer numerical control (CNC) manufacturing, rivets serve important purposes thanks to their design, installation process, and material versatility. Understanding the core uses of rivets in CNC can help manufacturers select the right fastening methods for their products.
Joining Thin Materials
One of the primary uses of rivets in CNC work is joining thin sheets of metal and other materials. Rivets create solid fastening points without requiring large holes to be drilled through stacked material. The shallow dome shape of rivet heads distributes pressure evenly, preventing cracks or tears in thin workpieces.
Riveting thin aluminum sheets is common in aircraft manufacturing. It allows for lightweight structures that are densely fastened for maximum strength. The aerodynamic head shape also minimizes air resistance. Rivets are likewise useful for joining thin sheets of fiberglass, carbon fiber, plastics, leather, and more.
Assembling Layered Materials
In addition to thin sheets, rivets are ideal for joining materials layered on top of each other. The rivet shaft passes cleanly through pre-drilled holes and is mechanically deformed on the opposite side to clamp materials together. This creates a solid connection point between each layer without adhesives.
For example, rivets can assemble layered materials like plywood, textiles, or composites. Multiple thin wood sheets can be securely fastened without risk of cracking. Insulation and waterproofing fabrics can also be riveted between exterior panels with a watertight seal. The versatility of this technique makes rivets invaluable for assembling multi-layered components.
Permanent and Non-Permanent Fastening
Different rivet types allow for both permanent and non-permanent applications. Solid rivets require tools to be deformed and cannot be removed non-destructively, creating lasting joints. However, blind rivets can be inserted and removed by hand, allowing components to be disassembled. This flexibility gives manufacturers options for one-time or temporary assemblies.
For example, a CNC-cut enclosure may use solid rivets for the permanently joined exterior shell. But interior dividers and mounts that require occasional access can utilize blind rivets. This allows riveted construction without sacrificing serviceability. The combination of permanent and non-permanent rivets is useful for many products.
Speed and Automation
Modern pneumatic, hydraulic, and electric rivet tools allow for incredibly fast installation. Robotic riveting systems can be integrated directly into assembly line automation. This makes riveting one of the quickest mechanical fastening methods available.
CNC programs can include rivet hole locations and patterns to precisely guide automated installation. Multiple rivets can be sequentially inserted in just seconds without repositioning. And with minimal clinching force needed, riveting has less impact on materials compared to hammering or pressing operations. The speed and precision of automated riveting is revolutionizing mass production.
Material and Design Versatility
Rivets come in a vast range of materials, sizes, and designs to accommodate different applications. Common materials include aluminum, steel, copper, stainless steel, and specialty alloys. Plated and coated rivets resist corrosion and chemicals.
Dome, countersunk, large flange, split, and specialty head shapes allow rivets to be optimized for strength, appearance, and aerodynamics. Different grip lengths join varying material thicknesses. This material and design versatility make rivets suitable for nearly any production.
Rivet Material Comparison
- Aluminum - Lightweight aircraft construction, low cost, lower shear strength
- Steel - Strongest and most rigid, heavier, prone to corrosion
- Stainless Steel - Corrosion resistance, high strength, for harsh environments
- Copper - Decorative, excellent conductivity, soft and easily deformed
- Titanium - Extremely strong yet lightweight, expensive, aircraft and aerospace use
- Monel - Resists corrosion and saltwater, used in marine applications
- Brass - Attractive finish, moderate strength, used for decorative purposes
Automated Production
Thanks to CNC and automation, rivets can be installed with incredible speed and accuracy. Precision riveting robots first drill holes according to digital design files. The rivet is then inserted and upset using automated pneumatic or hydraulic pressure to flare the tail.
This process can insert hundreds of rivets per minute without human intervention. Operators simply load rivet reels into feeder bowls that orient and deliver individual rivets to insertion heads. The elimination of manual drilling and setting reduces labor costs dramatically.
Automated systems can also perform quality checks, sorting or marking any rivets that are not correctly flared. Some vision systems even examine the flushness of rivet heads for cosmetic purposes. This consistency and error-proofing ensures reliable joining.
Riveting also introduces less stress into materials compared to welding, allowing thin and brittle materials to be joined. The rapid pace of automated systems makes riveting the ideal mass production fastening method.
CNC Precision
Computer numerical control technology allows rivets to be placed with precision unmatched by manual methods. By using digital design files, CNC systems know the exact location of each rivet in X, Y, and Z axes relative to the workpiece.
This allows flawless replication of rivet patterns across mass-produced parts. Spacing, hole diameters, and insertion depth can be dialed into tool controllers. Operators do not need extensive skill training.
Precision also prevents mistakes like misaligned holes or warped workpieces caused by off-center riveting forces. Automating the entire process - from hole drilling to insertion - guarantees consistency. CNC-guided riveting makes strong and seamless construction easy.
Streamlined Manufacturing
By incorporating riveting into overall CNC workflows, manufacturers can streamline production. Switching between drilling, cutting, and riveting operations is simplified by using a combined 5-axis CNC machine. The automatic tool changer shuttles between cutters and rivet insertion heads for flexible fabrication.
Engineers only need to program the desired hole locations and patterns. No manual layout or measurement is required since the CNC machine handles alignment and spacing automatically. This saves time and reduces dimensional errors.
Riveting also parallels other automated steps like robotic welding and adhesive dispensing. Manufacturers can develop entire assembly sequences under one flexible CNC platform. This consolidation improves workflow timing and reduces work-in-process.
Enhanced Strength
While adhesives join materials through continuous bonding, rivets provide localized clamping pressure. This reinforces products against shear and tensile stresses. Rivets also withstand vibration and impacts better than more rigid fasteners.
The multitude of tiny contact points created by riveting adds resilience against cracks propagating through materials. This helps finished products better endure applied loads and environmental conditions over time. The combined material grip and rivet shaft resistance enhances durability.
Well-designed rivet patterns also distribute stresses evenly across parts. This prevents failures originating from single high-load areas. The strategic use of rivets can significantly bolster product strength and longevity.
Improved Corrosion Resistance
Rivets help prevent corrosion by minimizing exposed material edges. Seams welded or bonded with adhesive have cracks and crevices where moisture can enter. This provides surfaces for oxidation to initiate. Countersunk rivets, however, form a flush connection that seals out water intrusion.
Selecting rivet materials like aluminum and stainless steel that resist corrosion further improves durability, especially in outdoor and marine environments. Coatings add another layer of defense against rust and other chemical damage.
Rivets also eliminate gaps where dissimilar metals would otherwise contact and corrode galvanically. Isolating materials from exposure provides robust, long-lasting products.
Conclusion
Rivets may appear simple, but their unique advantages make them invaluable for CNC manufacturing. Automation, precision, speed, and design flexibility mean rivets will continue enabling innovative fabrication. Understanding the core benefits of rivets allows engineers to produce optimized designs that leverage these fasteners’ strengths. CNC Milling
