ECOFLEX: Upgrade for shorter cycles

Continuous process optimisation is not the only crucial competitive factor in the automotive industry and this is why the compact, ultrasonic ECOFLEX welding booth was redesigned to manufacture the cover of the VW Tiguan glove compartment. It combines many work stages into one, at a reduced cycle time.

The first of a total of five ECOFLEX machines was delivered to Pirna in Saxony for the VW Tiguan and to Queretaro in Mexico for the VW Tiguan and Jetta as early as July 2015. Plug-in and welded parts are fitted on the machines in two variants of the glove compartment cover for right and left hand drive versions, one with integral central computer and the other with logbook. Because of the capacity expansion of the left hand drive Tiguan, the customer has now once again ordered almost the same machine for the Pirna factory. This time the requirement was for the ECOFLEX to be designed in such a way that the operator’s handling time is reduced and the screw buffers no longer have to be inserted by hand. For this purpose the upgraded ECOFLEX was equipped with an external vibratory hopper conveyor.

Once the operator has placed the component in the machine, the cover is riveted by ultrasound. Because the outer surfaces of the component being manufactured are visible, precise tool guidance is essential. In the subsequent step, the closure inserts and clips are pressed in. The Deprag vibratory hopper conveyor transports the screw buffers to the feed position. The buffer is pneumatically conveyed through the hose directly onto the screw bit underneath the component. The adapted mounting geometry optimally positions the buffer. Automatic assembly takes place alongside other assembly steps, whilst the component is secured by a hold-down device. Important for feeding the screw buffer is the length and angular position in the in-feed. The screw connection is monitored by torque and a position measuring system. On the one hand this serves as a means of quality assurance and on the other of monitoring the ongoing process. For automatic assembly of the screws, the working area was extended downwards.

Overall, the cycle time of the welding and assembly system was reduced by approx. four to five seconds thanks to the automatic feed. This is achieved because parts are inserted and bolted together during non-productive time. Also, unlike the precursor models, only one operator has to be deployed for loading and unloading and for pre-assembling the components on the machine.

Other special features of this project are undoubtedly the fact that the ECOFLEX operates with a total of 20 part checks to detect variants and test all assembly parts and 15 feed units, including four compact feed units, which makes optimum use of the work area. Several composite sonotrodes are also installed, two of which are triple sonotrodes. The benefits of this are space saving inside the machine as well as cost saving for the customer, because for processing two or three rivet pins in each case, requires only one feed unit, a converter and an ultrasound generator. By the intelligent use of all tool components, SONOTRONIC has succeeded once again in designing and implementing a suitable machine concept for the customer and to meet all specifications.

Effective: Nov 21, 2018