The advantages of the refrigerante of high pressesure for the mechanised aerospace

If it wants to apply refrigerante with effectiveness and mark the difference in the mechanised modern, this has to apply in shape of chorros of high pressesure, to the necessary volume and properly directed. Supply simply a flow of refrigerante or flood the zone of work no longer is sufficient.

The qualified application of refrigerante of high pressesure (HPC) can, on the other hand, mark a big difference regarding the learning of shaving, the thermal sensors distribution, the embazado of the material of the piece in the edge of cut, the superficial integrity and the wear of the tool. These basic factors of the mechanised, to his time, optimise the competitiveness and the quality.

The application of HPC in the operations of mechanised general of stainless steel and steel of low content in carbon marks the difference, but the use of refrigerante to high pressesure has his greater impact when they mechanise material more demanding, such as the alloys of titanium and the superaleaciones termorresistentes (HRSA). Like consequence, a series of new and recent developments have improved the interest and the availability of the HPC.

During the years 80 and 90, Sandvik Coromant developed his first version of Jetbreak: a first system of HPC. From several investigations, decided enter chorros precisely directed of refrigerante of very high pressesure (100-1.000 bars) in the tools of cut used to mechanise demanding materials, in matter of maquinabilidad and control of shaving. These chorros of refrigerante forced his step creating one coins of refrigerante between the shaving and the edge of cutting. This system gave place to a reduction of the length of contact, together with the temperature in the zone of mechanised. Another interesting result was to see how could influence in the form of the shaving, improving like this his control and even, in some cases, resulting in the split of the shaving.

For a series of special applications, Jetbreak turned into the perfect solution for the mechanised of materials of little maquinabilidad and/or of shaving complicated. Jetbreak Helped to increase our knowledge on the effect of the distribution of the pressesure of the refrigerante and on the size of the filters. Through the adjust of the data of the chorro, achieved create a formador of variable shaving, guide the thin shavings in the steering wished and, even, optimise the length of the same. Jetbreak Installed , to scale limited, to resolve particular problems of the oil sector, the aerospace and of the threads. Due to the fact that the system requires an installation devoted with tool holders special, the technology implemented , mainly, in machines of vertical turning.

A lot of machines CNC modern have of supplies of refrigerante to pressesures of from 70 to 100 bars like standard or optional option, with tanks and pumps adapted. This is sufficient to incorporate HPC, what will suppose a remarkable difference in the performance and in the results in the machining centres, of turning, vertical lathes and machines multitarea more usual. The standard team is sufficient to have of an easy canalisation of the refrigerante to the point of application of the chorro.

The modular tools are the optimum platform to the hour to mechanise with HPC, partly, to guarantee fast changes of tool and minimise the stops of machine, but, also, to ensure eficientemente the connections of refrigerante and the channels of the machine to the edge of cutting. The system modulate of fast change Coromant Attract was the base for the development of Jetbreak and is, nowadays, the platform for CoroTurn HP: the new modular tool HPC of Sandvik Coromant. Coromant Attract is now a standard ISO and an option in a lot of machines CNC.

CoroTurn HP Is instrumented to provide precise chorros of refrigerante of flow laminar parallel. These chorros create one coins hydraulics between the plaquita and the shaving, affecting to the form and to the flow of the shaving, and reducing the temperature in the zone of mechanised. Employ filters mounted near of the edge of cutting and project with precision the chorros of high speed, separates the shaving of the face of the plaquita, cools it and breaks it in pieces smaller, contributing like this to his evacuation. The standard size of the filter is of 1 millimetre and there is available also filters of from 0,6 to 1,2 millimetres for specific optimisations.

The profits in the operations of finishing appreciate even to pressesures lower, as much as to 10 bars in materials like the steel, the stainless steel, the aluminium, the titanium and the alloys termorresistentes. In addition to a greater derivative hygiene of the control of shaving, the HPC can optimise considerably the useful life of the tool (until 50%) and help to reach significant savings in the costs of production thanks to the potential to apply greater speeds of cutting.

More than any another factor, the speed of cut affects to the temperature of cutting and, therefore, to the wear of the tool. Increase the speed of cut in the titanium, out of the window of maquinabilidad more limited, reduces considerably the useful life of the tool. But, when the advance increases to a similar scale, appreciates , typically, a lower reduction of the useful life of the tool. This, therefore, often converts the advance in an attractor trucks road to optimise the speed of start of metal with a low effect in the useful life of the tool. Nevertheless, because of the greater strengths of cut as well as to the effect in the control of shaving, the high advance is not always an option in these machines.

The influence of the HPC can, therefore, provide a potential of increase of the performance through greater speeds of cut without the usual increase of the temperature and the reduction of the useful life of the tool. That is to say, the use of advances higher provides a clear effect of refrigeration, without need to apply greater strengths. In the classified materials as ISO S, can arrive to increase the speed of cut until a 20 by at the same time that it keeps the same length of cutting.

The inner turning also is an area in which the HPC can play an important paper to the hour to help to guarantee a good learning of shaving and improve the properties of cizallado in demanding materials like the titanium. In this sense, the concept adds a greater hygiene and a prolonged useful life to the tool in the operations of mandrinado. When mechanising holes relatively big and deep with bars of mandrinar, such as in pieces of trains of landing, the modular tools in the rear extreme and in the leading extreme of the tool can contribute big advantages. Be able to change the small head of cut in the bar mounted is so much fast like comfortable and adds a big flexibility to realise several cuttings in an only setting. CoroTurn SL Combines the bars of mandrinar antivibratorias with the blockade by slot of the heads, for the mandrinado of holes of depths of until 10 times the diameter of the bar of mandrinar, and is also instrumented with the capacity to apply HPC.

The effect that the HPC provides through the chorro of refrigerante also can suppose an advantage for the operations of milling. CoroMill 690 is a strawberry of long edge devoted for alloys of titanium that facilitates the mechanised with HPC. With multiple plaquitas positioned to compose the long radial edges of the tool, the filters of refrigerante have been strategically positioned to provide the profits of the chorro of high pressesure in each one of the plaquitas. Besides, in those cases in which it does not go to do use of all the capacity of axial depth of the strawberry, can employ caps, in place of filters, to avoid the cost of pressesure of refrigerante through unnecessary filters. The filters of the plaquitas that cut the final extreme are positioned of such way that contribute to the evacuation of shaving and avoid the re-mechanised of the same, especially, in cavities.

To end to guarantee that they apply the correct values for the flow and the pressesure of refrigerante, uses a skilled calculator to analyse how apply of the best possible form the HPC to the strawberry. This calculator employs data like the speed and pressesure of flow in the machine, the data of cut, the depth of axial cutting and the specifications of the tool. Likewise, the calculator determines the optimum size of the filter and can reduce the requirements of flow at the same time that keeps a flow of high pressesure of refrigerante through determinate holes.

Regarding the mechanised of titanium, this material is chemically reactive and like such tend to the embazado of the material of the piece in the edge of cutting. This phenomenon, usually, is a problem, since the remecanizado of the shaving and the atasco of the shaving toughened affect to the useful life of the tool. Often, the HPC can be a solution to warn the embazado in the edge when mechanising titanium or other pasty materials.

The application of the mechanised of refrigerante of high pressesure would not have to see like a half to compensate the derivative lacks of other factors of application like plaquitas unstable, general unsteadiness or data of wrong cut. The HPC is an optimizador when the operations llevar properly. The concept will provide the half necessary to reduce the length of the cycles and give a greater consistency to the quality and hygiene of the process in the operations of turning and milling.

Thanks to his availability in the current machines, the HPC is a very attractor trucks option in front of the need to optimise the operations of mechanised, especially when the learning of shaving and the effects of the demanding materials have a big impact in the operation. The increasing number of machines multitarea and machines of vertical turning of new generation has resaltado the profits of the mechanised with HPC, especially, from the perspective of the control of shaving. The problems caused by the accumulation of shaving are very important since these machines use , mainly, in workshops devoted to mechanise aerospace pieces in demanding materials.