Riveting machinery is a type of factory equipment that sets rivets automatically and at high speed. The machines are used for a variety of production processes including joining materials such as steel, aluminum and plastic. They are usually electrically (motor-driven) or pneumatically actuated, either as single-head or multi-head units. They come in several different styles, including impact and orbital riveters. They may be used to set the first, or retaining head of the rivet, and also to spread it into its final fastening shape using pressure or hammering from the insertion side.
There are many types of riveting machinery available on the market, from simple manual hand tools for use in light assembly, repair and maintenance, to fully automated robot-mounted systems that can run at a high cycle rate. Choosing the right machine for your application is vital to ensuring that your production line will be able to meet both your quality and throughput needs.
The type of riveting machine that is best suited for a particular product assembly process depends on the product quality characteristics you need, the cycle time requirements, the footprint or space you have to work with, and the power, cost and plant utilities available. The following sections describe some of the main categories of riveting machines available and the types of rivets they can handle.
Self-piercing riveting (SPR) machines can be portable, hand-held or robot-mounted and can set a range of sizes of blind (pop) rivets and tubular rivets. They have gained wide acceptance as a clean, low energy process and are an attractive alternative to spot-welding. The rivets have a high fatigue resistance and the process produces no fumes.
These machines can be powered by electrical or pneumatic motors, with the latter generally providing more force than electric models. Spiralform and radial riveters are both types of orbital forming machines that have a slightly different take on the forming method.
Orbital forming is typically done by a spinning tool called a peen that presses downward into the rivet, spreading it out to its final fastening shape as it rotates. It’s more accurate than impact forming, but takes longer per rivet – 2-3 seconds in some cases.
Dedicated monitoring systems monitor the setting force and punch movement throughout the riveting process to produce a force-displacement curve that can be compared with a trained reference curve. If the curve fits within a pre-set tolerance of the reference, the process is approved; if not, it may be flagged for attention or even halted. Orbitform’s ‘Watchdawg’ process monitoring system is a good example of this type of system.
For projects that require a double-sided joint, SPR is not suitable. Alternatively, conventional riveting can be used to join the components together. This includes applications such as brake linings for cars, aircraft and locomotives, metal brackets for furniture, and metal connectors for electronics or computer cases. There are also specialist machines for bonding or sealing fragile materials and brittle or corrosive ones. Riveting machinery