Forming Technologies
Verborg and Guillemin both have decades of experience in orbital and radial riveting. Each form of riveting has it's own advantages and disadvantages. On this page the general concept of riveting is shown and the explanation of two types of riveting.
What is riveting?
An easy way to show the riveting process is by crushing a sugar cube under a glass with a flat bottom (see left picture below). To crush the cube vertically, a lot of force is needed. However, if the rotate the glass gently in a circular motion (see right picture below), the sugar cube can be crushed in a different way, using less force. In this circular motion, the glass does not spin around it's axis and makes a conical movement.
Definitions
Riveting is an assembly method that requires a seperate axis to fix two various parts together. By cold forming the axis (or rivet), a head is created, fixating the two parts.
Crimping is a method which does not require a rivet. It deforms one of the two parts in a way that they are fixated together afterwards. This process requires similar tools and machines to the riveting process.
The tooling that is used to perform these material deformations is called a pin (or tool).
Verborg Engineering and Guillemin are able to deliver machines with three different riveting methods; Orbital, Radial and Press riveting. Press riveting requires six times more power then orbital or radial riveting.
Orbital forming
Orbital forming uses a gyroscopic movement to make a circular pattern over the edges of the rivet (see picture on the left). This allows the gradually deform the material from top to bottom and tangential.
This technology requires a relatively simple riveting head.
Pros:
- Cheap method.
- Higher operating speed / production capacity.
- Inconsistent flow patterns due to irregular material placement.
- Spinning radial forming tool results in safety risk, unsafer workstations.
Radial forming
Radial forming uses a hypocyloidal or "daisy" movement, the latter term comes fromt he daisy-shaped pattern the pin ends up making on the rivet (see picture on the left).
Aside from up and down and tangential like orbital, radial directions are now also added to the pattern. This results in a higher quality rivet and less friction between the rivet and pin.
Because of it's pattern this technology requires a more complex riveting head.
Pros:
- Less friction beween rivet and pin leads to longer pin life.
- Higher quality rivets, reduced risk on cracks and irregularities.
- More gradual deformation makes better results on harder materials, especially stainless steel.
- Radial forming pins do not spin, creating safer workstations.
- More expensive.
- Slower operating speed / production capacity
(Source: Guillemin and Verborg)