It was the demise of a subcontracting business with ongoing projects that led two engineers to step in and complete the outstanding projects. Seven years later Gary Hill and Stewart Shelton have built success with DForce Engineering Ltd, completing a string of prestigious projects for clients in the automotive industry.
The Leicester business has evolved to a team of 12 with an 11,000sq/ft facility. It was the kudos of completing three major (50+ robot) installation projects for Toyota across Europe that have contributed to the growth of the company. Over the last five years, DForce has counted the Sertec Group, a worldwide automotive supplier as a key client. The relationship has evolved from jig and fixture design to manufacturing, planning and software design – to full system supply. For the latest project, DForce incorporated the robotic expertise of FANUC UK.
The brief was to design two complete automation cells for the self-pierce riveting (SPR) and self-pierce studding (SPS) of aluminium underbody components for delivery as four complete sub-assemblies to a UK automotive production line. In each cell is a FANUC robot, a preferred choice of DForce and Sertec.
With the arrival of a new vehicle concept, Sertec required two separate automation cells for the vehicle underbody. Commenting, DForce Director Gary Hill says: “FANUC is the preferred brand of Sertec. As part of our design concept, we proposed to further utilise the larger of the cells with the addition of RH & LH Self Pierce Studded assembly parts thereby running three different assemblies through one cell by using a FANUC R2000iC robot – cutting the cost, floor area and cycle times by delivering two cells instead of three.”
The first cell has two manual loading and unloading stations, each working with a FANUC R2000iC robot. On one side, two assembly stations are fixing both two and three components together, a process that requires Self Pierce rivets of two different lengths and studs. The robot, an R2000iC/210F has a 210kg Stanley Tucker dual-feed rivet gun attached and it identifies the correct part and rivets. “We needed the capacity of the FANUC R2000iC/210F robot, as the rivet gun is very heavy. The R2000iC/210F robot has to maintain both a positional and repeatability accuracy of +/-0.1mm. The kinematics and precision are outstanding as the R2000iC/210F moves the rivet gun with repeatability 24 hours a day.”
Whilst this process is being undertaken, the second station is loaded with parts that are collected by the second robot, an R2000iC/165F which also picks the first completed assembly using a double-sided gripper and transfers it to a TOX pressing machine for Self Pierce Studs to be inserted. Discussing this, Gary says: “The cell has an output of over 80,000 parts per annum with a 96 second cycle time for the three assemblies. All three assemblies require studs or Self Pierce Rivets of varying lengths. To compare this to manual studding, the process used to take 8 seconds per stud and then you have to add non-productive time for loading, unloading and part re-positioning. With the new cell, the operator can spend 20 seconds loading the station and then move to another task. This is a massive saving.”
The second cell incorporates a manual load and unload station for two-part variants and the FANUC M-20iA/35M robot that transfers the assemblies from the manual load & TOX pressing station to the dual feed TOX pressing station. Alluding to this cell, Gary says: “The FANUC M-20iA/35M robot is compact with a small footprint and it has a maximum payload of 35kg. This suits this assembly as the gripper is 28kg and the assembly weighs just 2kg.”
This robot has a repeatability of +/-0.03mm and will identify the different hole positions and rivet sizes and press the 10 rivets through the holes. Discussing the timeline, Gary adds: “The design of the two cells was an 8-week process, we then spent another 16 weeks manufacturing the cell. The FANUC ROBOGUIDE system compressed this time. This robot simulation suite enabled us to simulate both the robot’s motion and application commands.”
The FANUC ROBOGUIDE system reduces 3D modelling times and enables part models and assemblies to be imported from a PC as CAD data. Designed to be intuitive and extremely easy to use, ROBOGUIDE requires very little training.
In conclusion, Gary says: “FANUC has been outstanding throughout the process. The robots have delivered everything we have required with precision, speed and repeatability and the FANUC ROBOGUIDE has compressed the timescale of the project immensely.”