Riveting in Sheet Metal using CNC Technology(cnc prototype Rose)
- source:ESKRIDGE CNC Machining
How Does Traditional Riveting Work?
In traditional riveting, a solid metal shaft is inserted into pre-drilled holes in two adjoining pieces of sheet metal, platter, or any other material. The rivet shank is then deformed on one or both ends using a hammer or rivet gun, fusing it to the materials being joined. This creates a permanent mechanical bond for the life of the product. Manually inserting and hammering rivets requires skill and is time-consuming, limiting its use in high-volume production.
Benefits of Automated CNC Riveting
Modern CNC riveting machines offer numerous advantages over manual methods:
- Speed and efficiency: CNC machines can rapidly insert and upset multiple rivets per minute without operator fatigue. This accelerates production times.
- Consistency and precision: CNC systems precisely control rivet placement and deformation according to programmed settings, ensuring consistency. This level of precision is difficult to achieve manually across numerous operations.
- Lower costs: Automated systems reduce labor requirements, associated costs and errors. The machines also minimize wasted materials from mistakes.
- Flexible production: CNC machines can be programmed for different rivet patterns, sizes, materials and sequences. Changes can be made quickly through software without mechanical alterations.
- Safer working: Taking operators away from heavy machinery and repetitive strain reduces injuries and fatigue.
- Smaller footprint: Automated riveting takes up less space than multiple manual workstations.
- 24/7 operation: CNC machines enable lights-out manufacturing with minimal supervision for maximum uptime.
CNC Riveting Methods
There are two main methods of automated riveting used in CNC machines: orbital and radial.
With orbital CNC riveting, the machine inserts a rivet into two stacked sheets and holds it in place with a plunger. An orbital riveting head then circles around the rivet shank while a hammer deforms the tail end of the rivet. This pulls the joint together.
The orbital motion ensures uniform pressure is applied from all angles to create a leak-proof connection. The CNC machine can control the hammer force, number of strikes and orbital speed to create optimal upset. Orbital riveting is ideal for watertight applications like electronics enclosures.
In radial riveting, the CNC machine centers the rivet shank between upper and lower riveting heads contained in a single assembly. The upper head holds the materials together, while the lower head upsets the tail of the rivet by striking downwards in a linear vertical motion.
By adjusting the closing pressure and striking force, the machine can control the flare of the rivet tail to lock the joint. As the heads are contained in one block, radial riveting provides excellent stability for high-speed, high-volume production. It is commonly used for vehicle panels, aircraft bodies, and railcar construction.
CNC Riveting Heads
The riveting heads used in CNC machines come in several varieties to suit different applications:
- Flat heads: General-purpose riveting for access where a countersunk head is not required.
- Countersunk heads: For flush final surfaces when the rivet head cannot protrude.
- Nose assemblies: For riveting into concave or confined spaces.
- Long reach tooling: For rivets inserted deep into pre-drilled holes or cavities.
- Multi-impact heads: For demanding high-strength structural joints that require extra hammering force.
- Hydroform heads: Use fluid pressure to flare rivets for imparting less stress on delicate materials.
- Specialty heads: Custom designs for unique joint, component or access requirements.
The CNC system can store numerous head configurations and automatically change tools as needed for the application.
Effective CNC riveting requires advanced programming to set the proper machine parameters. Software factors such as:
- Material properties of the workpieces
- Diameter and grip length of the rivets
- Desired set force and final head profile
- Number of strikes and strike rate for smooth upset
- Placement coordinates and rivet pitch
- Motion paths of the riveting axes
- Speed, force and other outputs for the servo motors
By incorporating this code, the CNC machine can control every aspect of the riveting process for precision joining. Operators simply load the materials and rivets, then let the automated cycle run.
CNC riveting is used across countless sheet metal fabrication sectors, including:
- Aircraft fuselages - Orbital riveting seals exterior aircraft skin joints.
- Automotive panels - Radial riveting assembles body panels and interior compartments.
- Building cladding - Vertical axis riveting machines install aluminum facades and roofing.
- Railcar assembly - Heavy duty frames and car bodies are joined by large radial riveters.
- Electronics enclosures - Miniature orbital riveting seals consumer device casings like smartphones.
- Appliances - Countersunk orbital riveting produces smooth exterior surfaces on laundry machines, ovens etc.
- Furniture - Rivets provide sturdy mechanical fastening for desk, shelving and storage products.
By enabling rapid, precision joining of sheet materials, CNC riveting machines are a versatile production tool across manufacturing sectors. With programming flexibility and custom tooling, CNC systems accommodate virtually any rivet-based assembly application. Automated riveting improves quality, reduces labor and expands the design possibilities using this trusted mechanical fastening method. CNC Milling CNC Machining