Requirements in the mechanical machining of components for the gas industry and other industrial sectors in very large production batches are evolving very quickly. Initially it was enough just to produce economically. A few years later, with the arrival of « just-in-time » and the annualization of stocks, the main customer requirement of manufacturers was flexibility. Manufacturers had to produce smaller batch sizes at the same price. Subsequently, with the opening of Asian markets, we saw European production sites relocated to countries with low production costs. The trend is now the opposite. To find out more, we met Mr Axel Warth and Mr Boris Sciaroni, respectively strategic and operational marketing managers at Mikron SA.
We have recently noticed the opposite phenomenon. There are two main reasons for this return of production to Europe, as Mr Warth explains, « On one hand the increased stringency of anti-pollution standards requires a higher level of precision in components and on the other hand OEMs have realised that the quality of parts produced in Asia is not always constant ». So we have seen the large-scale production of quality parts flourishing once more in Europe.
A high-requirement part One of the key components of a gas burner is the gas jet, which is a technological part including orifices which make it difficult to produce the part reliably in large scale production. The calibrated holes have very small diameters, generally from 0.14 to 0.80 mm with very close tolerances. Consistency in hole quality and the absence of burrs are rigorously checked using a flow meter, and sometimes the shape of the jet produced is analysed using a fluid. The jet must be homogenous and have a constant shape. As a result, gas jet geometry must be precise and the part must have an excellent surface finish and, most of all, quality has to be constant. There are about 20 machining operations involved, including the stamping of the part code and a hole presence check before the reaming operation.
24 machining stations Thanks to Mikron’s exclusive machining system, it is possible to produce these gas jets at a rate of 55 parts per minute while guaranteeing quality in round-the-clock production (3 shifts). The Mikron solution for the complete machining of gas jets is made up of a Multistar CX-24 machining system composed of 24 machining stations including the overturning of the part, stamping and control of hole presence. The high spindle rotation speed of up to 32 000 rpm means the most demanding operations can be carried out with no problem whatsoever. The blanks are loaded and the finished parts are ejected automatically. If required, the user can use Mikron Tool calibration tools for specific geometries or even mount a production unit to produce blanks from hexagonal wire coils (TF 120). This device includes the straightening of the wire.
Advantages of the Mikron solution
- 20% more productivity for this kind of part due to the large number of stations.
- A very high level of part quality. The machining tasks are spread over a large number of stations with simple tools and this « step by step » process is much easier to manage.
- Result reliability: the large number of stations means that various control and rinsing stages can be inserted to guarantee reliable production. If a tool breaks (e.g. a Ø 0.30mm bore bit) the system stops immediately, thus avoiding any breakage of the following tools (e.g. reamer) and prevents the production of defective parts.
- 35% less floor space: the Multistar machining stations are vertical, thus saving floor space.
- Flexibility: the large number of stations means you can leave a few of them « free » to use them for other parts. The implementation of a unit takes less than a minute, so it takes very little time to change equipment to switch over from one part to another.
We will go into deeper detail on how to produce with Mikron in our next issue of eurotec.
Mikron SA Agno P.O. Box 115 6903 Lugano Switzerland Tel. +41 91 610 61 11 Fax +41 91 610 66 82 [email protected] www.mikron.com
