Concept and simulation of robotized assembly application

Abstract: Assa OEM is a manufacturer of locks and fittings for windows, doors and cabinets. To be more competitive, automating the production is an advantage. Assa assembles six different types of left and right reversible hinges. One product stands for 80 % of the assembly time on the line. For this product Assa wants to implement a robotized assembly solution in one of the three assembly stations. The remaining 20% still needs to be assembled manually. The aim of this study is to investigate three assembly stations, select one assembly station to automate, give three concepts at half-time of the project for the selected assembly station and simulate one final automated concept. The assembly line produces approximately 2000 reversible hinges each day. For the stations in the assembly line the cycle time is around 16 seconds. In the three assembly stations the assembly tasks are similar, it is the number of rivets or parts that differ. In assembly station three there is one additional task that is not included in the first two assembly stations. In this task the arm is lifted and turned 180 degrees, and then placed over three rivets. This is more complex for a robot to perform and will require more equipment. There are similarities between assembly station one and two and therefore concepts for both stations will be given. Three layout concepts are presented for the first assembly station and for the second assembly station one concept is presented. Also, two concepts of combining assembly station one and two are presented. On April 17th, 2018, a meeting at Assa was held to discuss the different concepts and layouts. The discussion led to the conclusion that a further investigation on implementing a robot will be carried out for the concept in assembly station two. The main result is that the cycle time of 16 seconds is difficult to accomplish. The path must be well planned to achieve this with a collaborative robot. To attain the cycle time the end-effector must be designed so that no tool change will be necessary. The rivet is small and therefore a gripper would have difficulty gripping the rivets. Therefore, other methods such as ferromagnetic or vacuum are recommended. The feeder system of the rivet is suggested to have a vibrating bowl feeder due to the orientation of the rivets. The frames’ feeder system needs to be designed for the purpose in assembly station two. The frame that is to be assembled on to the fixture exposes a risk for an operator if working beside the robot. To minimize the risk area from the frame, relocation of the frame feeder and planning the path differently is suggested. The layout will require safety equipment and the suitable safety equipment depends on the flexibility Assa requires.