Riveting in Sheet Metal Using CNC Technology(is bronze copper Judith)
- source:MAJA CNC Machining
In this article, we’ll look at how CNC technology is used for riveting sheet metal. We’ll cover the basics of rivets, the CNC riveting process, specialized CNC riveting machinery, and the benefits of automated riveting.
The Basics of Rivets
A rivet is a mechanical fastener that joins two or more sheets of material by expanding when deformed. Rivets are typically made of metal, with a head on one end, a shank, and a tail on the other end.
To install a rivet, the tail is inserted into a pre-drilled hole through the materials being joined. The rivet is then deformed with a rivet gun, which smashes the tail to form a second head. This expands the rivet and clamps the materials together.
Rivets provide a strong, permanent fastening solution, especially for sheet metal. They can handle vibration and shock loads better than many other fasteners. Riveting also produces an aesthetically pleasing finish compared to welding or bolting.
CNC Riveting Process
The basic riveting process is enhanced and automated with CNC technology. Here are the typical steps for CNC riveting of sheet metal:
1. Sheet metal components are designed and programmed into the CNC machine. The riveting locations are specified in the CAD/CAM program.
2. Sheets are loaded into the CNC machine and positioned using precision fixturing.
3. The CNC drill head automatically drills holes at the programmed rivet locations. Deburring may also be programmed.
4. Rivets are fed automatically into the rivet setting tool from a vibratory bowl feeder.
5. The CNC sets the rivet by squeezing the tail between a reciprocating hammer and anvil. This expands the rivet and clamps the sheets together.
6. Quality inspection checks for properly set rivets. Errors can be reworked immediately.
7. Finished sheets are unloaded from the CNC machine.
This results in very high productivity compared to manual riveting. Hundreds of rivets can be set per hour with precision accuracy. The process is also highly flexible, with the ability to program different rivet patterns and spacings for each sheet metal component.
Specialized CNC Riveting Machinery
Several types of CNC machines are designed specifically for automated riveting:
- CNC riveting/spot welding machines combine both technologies for maximum flexibility. They use a servo-electric driven axis that positions the rivet gun and welder.
- Automatic panel riveting machines are optimized for high volume riveting of sheet metal enclosures and panels. They use multiple rivet heads working simultaneously.
- Computer controlled rivet machines mount the riveting tool on a gantry allowing 3-axis movement. This enables riveting of large aircraft and aerospace structures.
- Special heads allow rivet setting in hard to reach spots. Right angle riveting heads, for example, make setting rivets around corners easy.
- Robotic riveting workcells use an articulated robot arm for positioning. This facilitates integration into full automation manufacturing systems.
These machines are highly efficient while maintaining flexibility through CNC programming. Riveting patterns can be changed on the fly with no mechanical retooling required. This makes them ideal for medium to high volume production.
Benefits of CNC Riveting
Automating the riveting process with CNC delivers numerous benefits:
- Dramatically increased productivity - CNC riveters can insert hundreds or even thousands of rivets per hour. This shaves significant time compared to manual processes.
- Improved consistency and quality - CNC ensures each rivet is precisely positioned and set with equal force and alignment. This reduces errors and rejects.
- Riveting complex or challenging geometries - CNC allows riveting of parts difficult or impossible to rivet manually due to space constraints or complex contours.
- Lower operating costs - Automatic feeders reduce labor. CNC also improves material usage by optimizing rivet pitch.
- Reduced WIP and improved flow - Streamlined CNC riveting reduces work-in-process. Components move quickly from station to station.
- Flexible production - CNC riveting machines allow quick changeovers between parts. No manual tooling adjustments are required.
- Tighter tolerances - Precise hole drilling and rivet setting improves fit and finishes. CNC allows tighter tolerances to be held.
- Safer working environment - Automating dangerous tasks like hammering minimizes ergonomic risks to workers.
With these significant benefits, CNC riveting technology continues to expand in sheet metal fabrication. As the capabilities of CNC machines grow, so will the applications using automated riveting of sheet metal components. CNC Milling CNC Machining