Working machine serving
PROBLEM:
we have few and well clear objectives in designing our automatic serving cells: -saving manpower time; -high accuracy in material handling; -avoiding waste production due to human factors; -high flexibility to process new articles; -easiness in cell management. Hereafter we introduce the special case of silver gifts industry, where virgin material is made of a thin silver layer (0.015mm) stuck to an hard aluminum layer (0.3mm). The surface polishing of such a thin layer of silver can be easily damaged, so particular care has to be taken on material handling.
SOLUTION:
in order to let the cell working autonomously for a suitable time, special loading/unloading systems have been designed, fit for holding products safely. Great care has been taken in order to build soft tools for material handling with large use of silicone vacuum grippers. In addition a lot of efforts was spent in developing a reliable cleaning system both for metal surfaces and for mould: even the finest impurity is removed by very soft brushes and electrical charges are neutralized by de-ionized air blows. Two anthropomorphic robots are responsible for the accurate loading of pieces into the press mould and the soft stacking of manufactured items in the recipients of unloading system. It takes few simple operations to start up the production with a new model, even if the robots have to be trained for new positions: such a flexibility makes profitable even small lot producing.
ADVANTAGES:
with this design of our automatic cell, the efficient cleaning of both products and mould is provided. Moreover robot accuracy drastically reduces damaged plates. As a consequence, production quality is hardly increased and material wasting is limited to a minimum. Automatic production rate is incomparably higher than manual and so press work load can be optimized and material flow is scheduled for sure. Manpower is reduced drastically and limited to simple loading/unloading operation: this means costs saving. Producing small lot of an article is now possible: few minutes and the machine is ready to work.
DESCRIPTION:
pieces that have to be pressed are rectangular-shaped silver plates and are manually stacked up into special recipients with a very soft internal covering. These recipients are automatically moved by a closed loop system. From the recipients, plates are picked up one at a time by a hybrid robot, that is responsible to perform the cleaning of the aluminum side: a rotary brush is used to remove particles and de-ionized air is blown to neutralized electrical charges. The plate is then turned upside down and centered by a special device that let the robot pick it up with very high accuracy: rigid working tolerances are preserved. The first anthropomorphic robot picks it up and performs the cleaning of the silver side: the system is alike the previous except for softer brushes, in order to preserve the natural surface polishing. Then the piece is moved toward the hydraulic press: during its insertion into the press, a special cleaning device perform deep mould brushing, de-ionized air blowing, and suction of all removed impurities (both for the upper and for the lower part). After being pressed, the plate is unloaded by a second anthropomorphic robot that stack it up accurately on the unloading system recipients.
