The mechanisation of welding is divided into four levels according to the proportion of work stages done mechanically with a welding machine.
In manual welding, the welder moves the welding head manually as well as monitors and controls the welding process.
In semi-automatic welding, the welding machine carries out one of the work stages. Such a welding method can be, for example, MIG/MAG welding, where the wire feeder feeds the filler wire through the welding gun.
In mechanised welding, the welding system does the physical work but the welder continuously controls and supervises the process.
In automatic welding, the welding system does everything independently according to a preset program.
Welding robotics represents highly advanced welding mechanisation and automation. In welding robotics, the welding apparatus controls both the motion of the welding end and the welding process according to a preset program. The robot can also be re-programmed for use in different sites.
Better productivity and consistent quality
Welding automation usually aims at better welding productivity, higher production capacity, more consistent quality and cost efficiency.
In welding robotics, the cost structure is emphasised at the beginning of the acquisition, in cost f equipment, testing and user training. Therefore transition to robotised welding always requires careful advance planning. The existing welding production must be analysed with all work stages included and their related expenses must be itemised. In addition, the suitability of the products for robotisation must be studied.
Robotised welding is best suited for products that contain several short welds in different directions and the surfaces being welded are curved. Robotisation does not necessarily require that the product in question is continuously manufactured in large quantities. Modern technology allows for welding increasingly small series in a cost-efficient way. Even individual pieces have been successfully manufactured in robotised environments.
Enhancing robotised welding
Robotised welding can be enhanced by decreasing the groove volume. In mechanised and automated welding, the welds are of even quality, and therefore their minimum rated size can be utilised. Automated welding allows using the weld depth, or penetration, as part of the visible effective throat thickness. This is based on the fact that automated welding always takes place in the same way, and therefore a penetration once attained and measured will probably be attained in subsequent welds, as well.
Welding equipment designed for robotised welding should be used in a robot station to keep the welding wire feed good and even. Welding devices dedicated to robotised use allow the robot to control all features. Various signals and feedback signals have been designed according to the high quality and efficiency requirements of robotised applications. This avoids unnecessary downtime and improves the arc time ratio of the welding equipment.
