MACHINE FOR INPRESSING RIVET NUTS
Pressing four M8 rivet nuts simultaneously
The task in this project was to insert and press in two rivet nuts simultaneously in hinge reinforcements for engine hoods. The ergonomically height-adjustable system simultaneously feeds M8 nuts from a 4-lane sorting and conveying unit into correspondingly designed press-in heads and presses them simultaneously into left and right reinforcement plates.
This order for a Southern German automotive supplier involved pressing four rivet nuts into two hinge reinforcements for engine hoods and then attaching further components in the clamped condition.
A customized machine was required. BTM, a specialist in joining technology and special plant engineering, was approached. As a specification for BTM, it was particularly important to the customer that, despite the high pressing forces of max. 16,000 kN per rivet nut and the associated solid construction, a simple and user-friendly insertion operation for different insertion heights could be realized. The plant was equipped with two 30 ton BTM cylinders with 150mm stroke and pneumohydraulic drive.
In order to comply with the ergonomic requirements, the component pick-up including the joining station was designed to be continuously height-adjustable on an electric scissor lift.
The nuts are fed to the pressing heads via a 4-lane sorting and conveying unit. All nuts are pressed in at the same time and each individual pressing process is monitored online via a force-displacement process monitoring system. The entire cycle takes only 6 seconds.
In the following video you can see the entire process of the system for simultaneous pressing in of the four rivet nuts.