Choosing the Right Riveting Machine for Your Application
The right riveting machine will offer the proper speed, force and flexibility to your assembly process. Riveting machines are often used in manufacturing applications, including brake linings for commercial vehicles and aircraft, metal brackets and windows, mobile phones and leather products. Different rivet machines will have varying abilities and limitations depending on the type of fastening materials that are being used as well as the amount of automation needed for your production line.
Riveting machines are typically broken down into two categories – impact and orbital riveting machines. Impact riveting machines drive the rivet downwards through the materials being joined, squashing the rivet head into a forming tool called a roll-set, which causes the rivet to flare at its end and join the two materials together. The impact riveting machine is typically fast and uses a great deal of force to set the rivets.
Orbital / radial riveting machines use a similar method to create the desired rivet shape but do not apply any force until after the rivet has been formed and is in place. The forming tools on these machines are located on a rotating platform that allows the rivets to be inserted into and lowered onto the material stacks to be joined by the forming tool. These types of machines are slower and require a greater amount of manual input from the operator.
Another type of riveting machine is the self-piercing riveter (SPR). This fastening technique applies very little force to the head of a rivet, which helps to avoid damage to the surrounding materials. It is also a cleaner process than spot-welding because it does not produce fumes and requires much less energy. However, it cannot be used on brittle materials.
Choosing the best riveting machine for your application requires an understanding of the important factors involved in the product assembly process, such as cycle time requirements, footprint / space requirements and the cost and plant utilities available for powering the equipment. Also, you must consider other component fastening processes that might be more appropriate for your application.
When selecting a rivet machine, you must decide whether to use a manual feed or an automatic feed machine. Manual feed riveting machines require a human to guide the rivet by hand or with a foot pedal and then deliver the initial setting force to the rivet using a mechanical lever. Automatic feed riveting machines utilize a hopper and feed track to automatically deliver the rivets to the setting tools eliminating the need for human intervention and reducing assembly costs.
Regardless of the type of riveting machine chosen, it is critical that an accurate and repeatable riveting process be achieved. To help ensure this, a number of different monitoring systems are available. These are based on force-displacement technology that translates the punch movement and the setting force into a graph plot, which can then be compared to a trained reference curve to determine the quality of the riveting operation. An example of this technology is the ‘Watchdawg’ process monitoring system offered by Orbitform.