Valk Welding: 2001

Fort Kruiwagens in Tiel has invested millions in robotised production for wheel barrow undercarriages. The most important reason for this investment is not the time required to recover the costs, but supply reliability. In practice, the lack of motivated personnel is often one of the reasons to invest in production automation. Compared with the efficiency  and performance improvements, these are the main reasons. Companies want to deliver just in time and not to be hindered by personnel problems. Mainly companies using untrained employees for simple and monotonous work, take the step to employment of industrial robots in an early stage.

Fort Kruiwagens is a fine example thereof. The company produces 600,000 wheel barrows per year; a mass product requiring an efficient production process, if you want to do this in the Netherlands at competitive prices. The production company from Tiel has been doing this for over fifty years and has various welding robots and automatic bending devices. Although the production company does everything possible to create a pleasant working environment, the company was forced to contemplate its future. Business manager George Blom: "The existing automatic spot welding devices cannot be converted into new products and handling and putting down is still done by people; not exactly safe and healthy work. These obstacles had to be taken first in order to guarantee a healthy future. That is why we went searching for a solution with which simple and monotonous work could be robotised as much as possible, with possibility to exchange the product. Replacing the current fixed-systems, would be a 'dead end street'."

Solution
The most recent solution consists of a bending cell that bends completely automatically over the frames for the wheel barrows from a buffer with fifteen hundred straight tubes. The bending tool ensures that the frame gets its final form in one action. The frame is then taken by a Nachi handling robot from the bending tool and put in one of the six welding moulds. Fort has designed a special turntable that passes an assembly station and three Panasonic welding robots. In order to increase production speed, two welding robots do each half of the welding job of one frame. A central computer system monitors the weld and if need be passes on corrections to the third welding robot, that acts as a buffer to guarantee 100% reliable welding. The completely automatically welded frame is removed by the handling robot and stacked on pallets or put on a transport hook to the lacquer unit. Technically speaking, the collaboration between handling robot, welding robots and the bending process can be called unique. This solution could only be realised because the client Fort, the engineers of the bending cell (Busschers) and robot integrator (Valk Welding) came together in an early stage to discuss and solve this problem. Combining different production phases by different participants is clearly becoming a new trend.

Use
Fort has invested millions in the project, whereby according to business manager Blom continuity of the production and constant quality, are far more important than the time to recover the expenses. "In the old situation, the personnel expenses were 2.5 times higher, meaning that expenses cannot be recovered quickly. It is more important that we have attained a higher supply reliability and that we dispose of the production capacity, that we can adjust in the future to any product modifications. At the moment, we reach in daily production of 600,000 pieces per year. If we want to boost production, at least extra man hours will be required compared to the old situation. We will first practice with the cell and optimise its use where necessary, with the intention to employ a handling robot later to position the parts to be welded. Finally, the complete cell should be working 'idiot proof', so that anyone can operate the installation by just pressing a button.'

(Source: PTindustrie no. 19 - 2001)