Six-Axis Articulated Arm Robot Improves Overmoulding Process

As a self-contained manufacturer, Kammerer delivers complete heating and air-conditioning systems to almost all leading German automobile makers. Its Weilm?nster, Germany, plant is responsible for the production of electronics and plastics parts as well as equipment assembly. In-house research focuses on product redesign and further development with particular emphasis on the development of new process technologies for efficient production.

Together with Obernburg, Germany-based Reis Robotics, Kammerer has designed a production cell to manufacture a two-component front panel with dials as inserts. An articulated arm robot is the central component of this entire plant.

The whole plant is used to manufacture front panels for air-conditioning units, incorporating the necessary dials that are already labeled with text or symbols. As installed, the injection moulding machine, the film storage station with the Scara robot (beyond which is the transfer station), and finally the container for the finished parts form a semicircle around the robot, which operates all of them. Compared to linear handling machines, articulated arm robots profit from additional degrees of freedom, a feature that enables them to optimally utilize even small working areas.

How the robot manages the process

At the beginning of the production process, a Scara robot removes 2x2 circular, already labeled films (for the dials) from a stack and deposits them on a slide unit. On this slide unit, the films are folded in a linear movement before being extrusion coated and receiving antistatic treatment. The robot then unloads the slide unit and transfers the films to a pickup station, where they are taken over by the articulated arm robot.

Equipped with a multifunctional gripper for a total of three gripping tasks, the robot removes the films from the pickup station. Then, the injection moulding machine, featuring a rotating table, opens. Inside, the films are overmoulded with a transparent material, and then overmoulded with black plastic.

The robot moves into the opened two-cavity mould, and using its second free gripper, removes the finished parts. During this process, the sprue is separated and dropped into a collector inside the machine area.

The new circular films are inserted into the now free mould cavities. An integrated pneumatic valve releases compressed air to press the films onto the mould. As soon as the mould starts to rotate inside the machine, the injection moulding cycle begins. The first overmoulding process with transparent material takes place on the remote side of the mould relative to the robot. After the second partial cycle, the finished parts end up on the side of the mould facing the robot. This shortens the moving distances and facilitates insertion and removal.

After removal from the machine, the finished parts are deposited on an additional intermediate station, and once more taken up by an integrated pair of gripper jaws-the third gripper function. Then the parts, in upright position, are palleted on a rack opposite the machine. As soon as one pallet is completely filled, it is lowered onto a carriage which automatically leaves the robot's working area by descending down a slanted ramp and passing through a self-opening protective door.

The robot technique

The RV16 model of the Reis articulated arm series offers a lifting capacity of 16 kg. With its six axes, sufficient degrees of freedom are available for the robot to operate all stations. Due to the ratio of working space to floor space, this machine may be used even if space is limited. All mechanical and electrical subassemblies are easily accessible; the mechanical parts of the flexible wrist can be exchanged in a few minutes.

The exceptionally large working area of this machine was achieved by shifting the second rotational axis forward. The arm lengths and the pivoting angle are optimized to allow a standing and a hanging arrangement, resulting in further expansion of the usable working area.

The integrated development of all primary components (control system, robot, and gripper) is particularly advantageous. The combined effect of optimally adapted components affords an automation system with process reliability.

Contact Information Reis Robotics GmbH Mr. Michael Wenzel P.O. Box 110161 D-63777 Obernburg Germany Phone (49) 6022 503107 Fax (49) 6022 503110