A Riveting machine is a customized machine that has been designed and built to perform a specific riveting process. It is often used in automated production to speed up the process and increase assembly productivity. To select the right riveting machine, it is important to know your product assembly objectives and constraints and the various fastening processes that are available.
In addition to traditional riveting machines, there are also manual hand tools that can be used for light assembly, repair and maintenance work that requires a variety of sizes of semi-tubular and blind rivets. These tools usually clamp to a bench and the operator places the rivet on the anvil, positions a roller above it and then whacks it with a hammer to roll the edges of the rivet. This method is relatively cheap and easy to use, but it does not provide the tight bond of other methods of riveting and does not hold well in many applications.
Typical applications for rivets include securing thin sheets of metal, leather or plastic together, securing small electronics components and attaching handles to products such as luggage and car seats. Standard pop or blind rivets can be used in most situations, but they have a limited strength and should not be used to secure pieces that will carry significant weight. There are also stronger self-piercing rivets that can be used to join thinner materials but only in locations that can be easily accessed and removed for maintenance or repair.
Riveting machine types can be divided into two broad groups — impact riveting machines and orbital (or radial) riveting machines. Impact riveting machines set the rivet by driving it downwards through the materials to be joined and into a forming tool known as a rollset. The end of the rivet is then formed by this forming process, which creates a head on the rivet that fastens the materials together. The process is typically very fast, with a cycle time of only about 0.5 seconds.
Radial riveting machines operate in a similar fashion but the rivet is set into a closed jaw of the machine instead of an impact hammer. This allows the process to be used on deformable materials such as bakelite or ceramic, and it provides good joint strength even in situations where the rivet cannot be inspected from both sides after riveting. The process is very smooth and quiet compared with other joining methods, and the close-up inspection of the completed rivet is simple.
To ensure that the riveting machine is performing the required tasks accurately and consistently, it may be equipped with a system of process monitoring. These systems typically incorporate dedicated sensors that monitor the setting force and punch movement, which results in a force-displacement curve. This data can then be compared to a pre-trained reference curve. For example, Orbitform’s ‘Watchdawg’ system uses up to four positional sensors and up to two pressure sensors to track the location of the punch and clamp/punch pressures.