A riveting machine is an automated process for fastening two laminated materials together with a metallic fastener called a rivet. It offers increased consistency, productivity, and lower cost than manual riveting. Riveting machine can be powered by electricity, gas, pneumatic (pop riveters and air riveters) or hydraulically.
The most common type of riveting machine is a self-piercing riveter. This machine can be robot-mounted to operate in a flow-line and produces a high-strength joint with good fatigue resistance. A cycle time of 1 to 4 seconds is typical, and the tool has a long service life (in excess of 200 000 applications). This type of riveting machine can be used with all materials but is most suitable for metals such as aluminium and titanium.
Other riveting machines can be driven by a piston, rotary or orbital action, depending on the assembly requirements. These include radial and orbital upset riveting, hot upset riveting and cold upset riveting. For some fastening processes such as forming and forming-and-riveting, a combination of techniques is required to achieve the desired results. The process of forming can be achieved through a riveter or rotary tool and is commonly used in conjunction with a heat-treating system. Hot upset riveting can be used to form difficult-to-form metals such as tungsten, and cold upset riveting is useful for plastic materials such as polypropylene or polyvinyl chloride (PVC).
While welding and riveting are broadly popular joining methods, each has unique traits that make it better or worse for certain products. For example, welds produce a permanent and stronger joint than riveted joints, but the use of heat makes it unsuitable for many aluminium products such as kitchen utensils. Riveted products, on the other hand, are easier to disassemble than welded ones and can be inspected for quality.
The emergence of these new riveting technologies can help companies streamline their production lines by eliminating the need to manually set each rivet. The specialized riveters are designed for a specific riveting process and can automatically install them in the correct position to maximize quality. Some riveters even allow for remote control, allowing technicians to monitor production from a safe distance and perform maintenance on the equipment without going out onto the floor.
Riveting machine types vary according to the riveting process and materials being assembled. Some are specialized for specific applications, such as aerospace or automobile parts. Others are more versatile and can be used in a variety of materials, including wood, metal, textiles, or plastics. Some can even be used for riveting a combination of materials, such as an aluminium-steel alloy.
Dedicated riveting machine process monitoring systems, like Orbitform’s Watchdawg, provide the ability to detect and correct faulty riveting processes before they can damage parts or cause structural failures. They work by monitoring the setting force and punch movement throughout the riveting process to create a graph known as a force-displacement curve. The curve is then compared to a trained reference curve to determine whether the riveted part meets the required standards. If the process falls outside of the tolerances, the tool may be flagged and the process halted immediately.