Valk Welding: 2005

Dejo Metaalindustrie in Wolvega will employ a welding robot installation to weld single pieces and small series. Such flexible use is enabled by applying a parameter programming method, that Valk Welding has developed for the Dejo products.

Dejo produces grids and stairs. The grids are made either of steel, stainless steel or aluminium. The welding robot installation includes among others two robots on a traverse and two separated clamping tables of 2 m x 3 m, with which the grids can be clamped during production. The clamping tables are provided with automatic clamping systems and are suitable for all sorts of formats that fit within the clamping range of the table.

  

For Dejo director Franc van Wilgen the new welding robot installation is the following achievement in a series of investments, done in order to further strengthen the market position and safeguard the company's future. For the production of small series, Dejo has little to fear from low-salary countries. Nevertheless, optimal quality, efficiency and working conditions are constantly improved. In this way, Dejo recently employed a powder coating facility, complete with a section to pre-treat the products. Together with its own galvanising section, Dejo will thus have ample facilities for surface treatment. In both sections, products for third parties are being treated. Of course, this is very positive for grid production. In this way, Dejo is able to keep quality, costs and delivery time in hand.

Single pieces
In the past, Dejo mass produced grids with standard dimensions, nowadays there's only talk of single pieces and small series. Jaap de Boer, production leader grids, explains as follows: "That has to do with the modified application of the grids. Before, a grid was mainly used as industrial gangway. In the past decade, architects started to use our grids increasingly as a visual element". The grid carriers and fillers are produced from coils in various standard sizes. Next, these elements are assembled to complete grids in mounting machines (fixed systems), whereby the edges are being welded-on with an NC welding machine. Grids with special edges and notches, cattle grids, stairs and all sizes that are too large to be handled by the NC welding machine, are welded manually and partly by welding robot. Jaap de Boer: "The volume of manual welding work increases, that is why we wanted to expand the use of welding robots. But programming with a teach box was not efficient for smaller numbers, let alone for single pieces".

Parametric
"Valk Welding therefore proposed to simplify programming by making use of the possibilities of parametric programming. This means that they write a welding programme for our grids, whereby programming is thus simplified that the operator only has to enter length, width and height of a grid, and the software will generate the welding programme. Valk Welding delivers this as Custom Made Robot Software, to be added as plug-in to its DTPS-programming and simulation software system. In doing so, we can also efficiently produce single pieces with the welding robot," says Jaap De Boer of Dejo.

With parametric teaching, or parametric programming, variants of an existing product can rapidly be set-up, without having to re-introduce the data for welding parameters, torch positions, welding movements, etc. Parametric teaching is based on parametric programmes within DTPS II. Valk Welding  programmes a once only master model within DTPS II, containing all three-dimensional steps and default parameters. The user can always make a variant of the master model by introducing the variable X-, Y- and Z-values. This automatic programming results in an enormous gain of time, and high user comfort. Programmes will be copied automatically and shifted, based on calculations carried out by the CMRS software (Custom Made Robot Software). The system input is done manually or directly from the SQL 2000 database of Exact Globe 2003. Before, a new programme had to be made in a copy of an existing product, meaning a lot of hand work and a greater risk of making mistakes.

Two Panasonic welding robots on traverse
The total installation includes two Panasonic welding robots - type VR 006L, moving on a traverse over both clamping tables. It is remarkable, that the robots move in a standing position over the clamping tables, rather than in a hanging position This has been done in order to enlarge the working area. The grids are being welded simultaneously by both welding robots, not only to shorten process time, but also to evenly distribute the stress on the workpiece during the welding process. Due to the alternating installation, one side is used for welding, while on the other side workpieces can be clamped and removed. The welding robots have a high welding duty. The complete installation, including exhaust system, has been built by Valk Welding for Dejo during the summer closing period.

High quality first
Dejo Metaalindustrie in Wolvega employs 150 people in the grid plant, galvanising plant, pre-treatment and powder coating department. The company has grown thanks to the high quality of its products. Due to the combination of galvanising plant and powder coating department, Dejo is able to give its products a high added value, thus ending up in the top segment of the market segment for grid manufacturers. After the galvanisation process, the workpieces are deburred, degreased and chrome plated, then they receive one or two layers of coating. "High quality finishing for customers who want nothing more than the best".

Advantages of employing welding robot for Dejo
- Predictable process times
- Constant quality
- Reliable
- Failure percentage none
- Healthy and safe
- Cost-saving