The 100,000-square-meter Ford motor assembly plant in Sao Paulo, Brazil, has 1,200 employees working in three shifts. Every day, the plant produces approximately 1,100 engines for Ford's Fiesta, Courier, Focus, Ka and Eco Sport models. The production process spans everything from forging and milling the cylinder heads and the engine blocks to final assembly of the complete engine.

One of the critical points in the assembly process comes when the head is joined to the block. The various engine models are built using 23 different combinations of head and piston types. Ford uses a DVT Machine Vision system (Duluth, GA)-installed this past January-to ensure that every engine proceeding down the line has had the correct head and pistons installed.

During the inspection process, as a block comes down the line, it passes over a part scanner. Via serial communication, the part scanner tells the programmable logic controller what engine model is being assembled, which in turn tells the DVT system what product file to select. A robot then presents the block to a DVT Legend 530 camera, which verifies the engine model. The camera looks for a small indentation pattern on the top of the first piston. Different indentation patterns are used to identify different engine types.

While this is happening, a DVT Intelligent Scanner is also reading an etched or forged code on the head to ensure the head matches the block. The Intelligent Scanner communicates the information to the programmable logic controller. If the head doesn't match the block, the system shuts down, and that portion of the assembly process is halted. If it does match, an assembly robot is given the green light to proceed with positioning the head on the block. The piece then continues down the line for manual assembly.

Dark field illumination is used for the Intelligent Scanner inspection, and an infrared illumination light is used with the 530 camera. The assembly robot is guided by sensors and its own programming technology. It is instructed to go to positions, perform actions and wait for the next instruction.

Every inspection station in the engine assembly process gathers its own data. If there is an event anywhere on the line that potentially affects quality control, it can be traced back to the station where it happened.

For more on machine vision, call 770-814-7920 or visit www.dvtsensors.com.