Introduction(304 vs 316 stainless steel Brian)

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Riveting is a common method of fastening multiple sheets of metal together by inserting a metal fastener called a rivet. This creates a permanent joint between the sheets that is strong and secure. In recent years, computer numerical control (CNC) machines have been used to automate and improve the riveting process for manufacturing industries that work with sheet metal.
Benefits of CNC Riveting
CNC riveting offers several benefits over traditional manual riveting:
Speed and Efficiency - CNC machines can place rivets much faster and more efficiently than human operators, leading to higher productivity. Hundreds or even thousands of rivets can be precisely placed per hour.
Consistency and Accuracy - The computer program guides the CNC machine to consistently place each rivet in the programmed location accurately. This level of precision is difficult for humans to achieve repeatedly over long periods.
Flexibility - CNC machines can be programmed for different rivet patterns and sizes. The riveting operation can be quickly changed over between production runs of different products.
Reduced Labor Costs - Automating the riveting process means less manual labor is required. This reduces the riveting costs for manufacturers.
Improved Quality Control - Monitoring systems can track each rivet placed to ensure proper installation. This leads to higher riveting quality and less rework.
Ability to Handle Complex Jobs - CNC machines can handle complex riveting patterns that would be extremely difficult or impossible to do manually.
Safe for Workers - Automating dangerous tasks like hammering rivets removes risks of injury to workers from repetitive strain or impact.
Riveting Applications
CNC riveting machines are commonly used to fasten sheet metal components together in many manufacturing industries including:
Aerospace - Aircraft bodies and wings are riveted sheets of lightweight metals. Riveting aluminum alloys is a standard process in aircraft assembly.
Automotive - Doors, body panels, and frames involve sheet metal parts riveted together on auto assembly lines. High-speed CNC riveting achieves fast production.
Electronics - Metal enclosures and chassis for computers, appliances or machinery often use CNC riveting of sides, faceplates and brackets.
Construction Equipment - Exterior panels and cabins of heavy equipment like cranes and bulldozers are riveted sheets for durability.
HVAC Ducting - Sheet metal ducts for heating, ventilation and air conditioning systems are joined by machine riveting.
Basic CNC Riveting Process
A basic CNC machine riveting system involves the following components and sequence:
1. Sheet Metal Loading
The metal sheets are loaded into a fixture that holds the parts correctly aligned. Manual loading or robotic arms may be used.
2. Hole Drilling
If holes don't already exist, the CNC machine will automatically drill holes for each rivet location in the sheet metal stack, using a drill bit.
3. Rivet Feeding
Rivets are fed into the nose of the riveting tool from a magazine or automated feeder that supplies the right rivet size and style.
4. Rivet Setting
The rivet is pressed into the hole by the riveting head which flares out the tail of the rivet. This mechanically clamps the sheets together.
5. Clinching
The rivet shank is pressed further so it completely fills the rivet hole to maximize strength. The force expands the rivet head.
6. Ejection
Excess material is sheared off by the riveting tool jaws leaving a flush rivet head. The scrap falls out of the work area.
7. Cycle Repeat
The process repeats for the next programmed rivet location until the riveting sequence is complete.
8. Part Unloading
The finished riveted assembly is unloaded from the CNC machine fixture by hand or using automation.
CNC Riveting Tools
The heart of any CNC riveting system is the riveting head. This pneumatically or hydraulically powered tool presses rivets into the workpiece to flare and join the materials firmly together. Common types of CNC compatible riveting heads include:
Squeeze Riveters - Uses jaw-like dies to squeeze the rivet tail and flare it outward. Best suited for softer materials.
Impact Riveters - Hammers the rivets in place rapidly using a piston driven by compressed air. Used for higher volume riveting.
Orbital Riveters - Uses a pneumatic piston to press a spinning rivet setting tool down on the rivet head for a circular motion that flares the rivet smoothly.
Radial Riveters - Employs a pneumatic cylinder to push fingers outward radially against the rivet shank, flaring it. Allows access in confined spaces.
Specialized heads are available for unique applications like blind rivets, large diameter rivets or heavy duty rivets used in very thick stacks of metal sheets. Proper riveting head selection ensures optimum performance on the material being joined.
CNC Riveting Fixtures The fixture holds the workpieces firmly and properly aligned for the riveting operation. Fixtures keep thin metal from deforming under riveting pressure and allow high-quality, consistent results. Simple fixtures use manual clamps while hydraulic or pneumatic fixtures offer flexible automation.
Dedicated fixtures are tailored to specific parts and rivet patterns. These provide maximum speed and accuracy but lack flexibility. Standard modular fixtures adjust to fit families of similar sheet metal components. Quick change tooling allows reconfiguring the fixture quickly between production runs.
Software for CNC Riveting
Specialized software is essential for programming automated riveting patterns into the CNC controller. The software allows the operator to simply enter the desired locations of each rivet rather than complicated machine code.
Powerful CNC riveting software provides options like:
- Import CAD models, drawings or templates to simplify programming.
- Optimize rivet patterns for strength/stress analysis.
- Simulate the riveting sequence realistically off-line.
- Collision detection ensures no interference with clamps, tooling or other hardware.
- Generate machine code to drive different brands of CNC equipment.
- Interface with hole drilling patterns and other fabrication processes.
- Track production data and riveting quality analytics.
Other factors like selecting suitable rivets, work support, accessorizing and integration must also be addressed but user-friendly software makes programming efficient and error-free.
Conclusion
Riveting sheet metal components is a common fabrication technique that is benefiting from automation using CNC technology. Precision computer numerical control riveting provides manufacturing efficiency, consistency and quality. While initial investment is required, integrating CNC riveting ultimately lowers production costs while meeting high standards. As tolerances shrink and competition rises, CNC systems offer metal fabricators an economical solution for enhanced fastening performance. CNC Milling CNC Machining