METAL LS, the Bulgarian manufacturer of door locking systems, door and window handles and building hardware, started planning the new automated assembly of door locks in 2019. The robotic systems that the company already used for other applications were too large for the planned production site, so the new solutions needed to be as compact and precise as possible, in addition to being state of the art. Door and security locks are precision parts with standard dimensions and components stipulated in DIN standards. Therefore, quality and precision were especially important deciding factors for METAL LS. In addition, the robots needed to achieve high productivity, assembling between 10 and 14 locks per minute. The company also needed a high level of flexibility from the solution and the possibility of retooling so that they could reuse the same system to produce different types of lock in the future.

Following a comparison of various manufacturers and products, METAL LS opted for a robot system from Delta. It was the only manufacturer to offer a complete solution including programmable logic controllers (PLC), a human-machine interface (HMI), servo systems and robotic arms with Machine Vision.

For implementation of this project, METAL LS and Delta collaborated to develop a custom workstation for assembly of the mechanical door lock components. The main part of the system comprises a rotation table, on which seven six-axis DRV90L7 articulated robots are installed. The robots are capable of extremely precise, quick movements and feature a hollow wrist that allows them to be easily combined with the correct tool for each production step. The DOP-115MX HMI is used to visualise all processes and enables the user to select various receipts for different locks via a touch screen. It also displays system information and alerts or alarms. The AS300-series (AS324MT-A) PLC monitors the assembly line, controls the ASDA B2 servo drive and communicates with the servo drive on the rotating platform. Two DMV2000 Machine Vision image processing systems equipped with cameras are installed to localise components on the conveyor and send accurate signals to the robot allowing it to pick up and assemble the parts. The AC servo system comprising ASDA-A2 and ASDA-B2 drives as well as ECMA motors ensure that the robot arms are positioned precisely and that high productivity can be maintained.

A few adjustments to the parameter settings were sufficient to quickly overcome initial communication problems between the PLC, robot and the Machine Vision system. The careful preparation and system configuration carried out by the Delta team also ensured that all of the Delta industrial automation (IA) products were soon integrated into the production processes.

All stakeholders are extremely happy with the progress made in the project. Alongside the quality of the compact robotic system, METAL LS is particularly happy with the sound advice and customer service it has received from Delta. With many different production sites and teams throughout Europe, Delta is able to provide all of its customers with the support they need, when they need it. The project was kicked off when the Field Application Engineering (FAE) team arrived on site to support construction of the assembly system together with Mechatronics, Delta’s Bulgarian partner. The assembly system is still undergoing tests, but initial results are already showing improved productivity and performance.

Jason Wu, Field Application Engineer at Industrial Automation Business Group, Delta Electronics EMEA region, is very happy with the successful collaboration: “With our broad portfolio of IA products, we are able to offer our customers powerful full-range solutions from a single source. Our teams of experts will support clients in implementing the specific project requirements, no matter whether the clients are in the food, drinks, packaging, electronics or automotive industry.”