Machining precision molds

The moldistas is obviously a category. But it would be a mistake to consider it a homogeneous category for the purposes of the technologies of mechanization. Each moldista has requirements and own specifications, often requiring targeted technology. In this scenario, the technologies to the work of precision molds recover particular interest.

This model is designed to produce precision molds

The LX of Matsuura, represented in Spain by Maquinser, machinery and services S.A., is a line of machining centers vertical of high speed, designed specifically to meet the requirements of the moldistas producing moulds for precision of small and medium-sized.

"The Japanese Matsuura - explains the director of the firm, Antonio Postigo - is a medium-sized (based on the local standard), character family, economically strong and technologically advanced."

Characterized by a unique and strong production orientation, Matsuura produces only five axes and horizontal, vertical machining centers. "This approach has enabled a high specialisation in this sector".

In Spain it is represented, for about twenty-five years, by Maquinser. But it is important to stress that more than one represented one can speak of a real and strong concrete Association. Matsuura has a name and a history established in the technology of mechanization of high speed mould of high precision with warm materials, which develops from the early 1980s.

This sector (and the aeronautical sector) have joined them, with the passage of time, another market, high production, very interested by the good performance of the Matsuura machines.

"The new LX line is intended to give new impetus to the sector of the moulds - explains Postigo." This line was specifically created to meet the following requirements: reduction in the time of development of new products; reduction of production costs; response to new environmental requirements; production chain; machining of small and medium-sized, complex and precise moulds. You just have to think that with this line it is possible to obtain a reduction in the time of the cycle of machining of up to 60 per cent compared to the conventional mecanizaciones (have been ample evidence on the matter), with a significant savings of electric energy andTherefore, a collection of one of a high delivery relationship / energy costs, which could not be otherwise. This is, therefore, concrete answers to the real problems of the moldistas. "On this basis we can say safely that the line LX currently represents a masterpiece in high speed and high precision issues"

The LX-1 machining center is characterized by:

• a shift of the axis X = 500 mm,

• a displacement of the shaft and = 500 mm,

• a shift in the axis Z = 300 mm,

• a work table of 540 x 320 mm with a maximum load of 500 Kg.,

• a speed as fast on the axes X - Y - Z of 90,000 mm/min,

• acceleration of 1.5 g.

Your configuration is composed of a "gantry" special that represents an optimized symbiosis, thanks also to the broad appeal of the FEM method and ugly, structures made with various materials (cast iron and aluminium).

The result of this optimization has led to the development of a broad base of iron smelted veined, very rigid and very heavy (5,000 Kg), a cross-cutting and a head that supports the line spindle, fully in aluminium alloy.

"We know that a very stable structure - pursuing Postigo - is essential to obtain a high precision and high reliability, especially when work with very high speed and high acceleration should be." Why have developed a cross-cutting and a head very compact and very light, but at the same time, extremely rigid with a minimum distance between the line of the spindle and the Guide to the Z axis. To increase the stability of the head and the achievement of a high dynamic response, two-cylinder balanced which make it possible to avoid any deformation caused by the weight of the head moving at high speeds of labour envisaged have predisposed.

The choice of a special "gantry" structure and movement of the work on a single axis table have also been important.

The movements on all axes have been on Rails which ensure an accuracy of less than 2 microns positioning; rollers of double contact (upper and lower) on all axes allow transferring the rigidity of the base to the rigidity of the guides in movement.

Spindle drive: a rotary engine converts motion into linear

Linear drive: is directly used linear motion

The machine is equipped with linear motors on all axes.

"The linear motors - says Mr. Postigo - have been a forced choice." In fact, the direct transmission of force achieves the maximum dynamic and at the same time, high speed, virtually without game and sobrealargamientos. Also eliminates the mechanical wear of the engine components (due to the absence of elements subject to wear kinematic), movements are soft and dramatically decreases the need for lubrication of conventional type that can be, at long last, eliminated in the case of the guides (Matsuura system).

On the other hand, it is known that the principle of the synchronized Motors implies a strong warming in the first part. But thanks to the particular configuration of the machine, its characteristics of termosimetría (which enable to avoid structural deformations in respect to the level of work and the line of the spindle), the combination of materials and the cooling system of which the elements of the linear motors are equipped withLX-0 is in possession of a very high stability and therefore a very high precision. It can reach high speeds in rapid (90,000 mm / min), with accelerations and decelerations equally high (1 G) on a spindle, with standard configurations, can go to a speed of up to 40,000 rpm. We can say, on the other hand, in general, with a system of conventional movement with screw of ball bearings, the circularity error reporting increases than van correlated with the increase of cutting speed: with the linear motor technologyeven at higher speeds of mechanisation provided for, the machine continues to perform planned accuracy and a high surface quality.

The machine has a very rigid construction

On the other hand, since the relationship between the stability of the structure and the available speed, either to the spindle, either on the linear motors, they imply a high speed of resolution, absolute linear scales pressurised on all axes have been used, thanks to very low resolutions (5/100 microns) can also obtain recovery of any loss of accuracy. Of the tests carried out, the error of circularity about a radius of 100 mm and with a preview of 12,000 mm/min is less than 1 micron.

The precision of parts and the quality of surface finish obtained with the LX-0 can eliminate the time required for the operation of grinding. "The constancy of accuracy over the entire surface of work, allows, indeed, the use of tools of small diameter of values up to 0.4 mm with the obtaining of a surface roughness Rmax = 2.21 microns".

Matsuura for some twenty years used Hi-Tech spindles with bearings of ceramic sphere. The LX-1 is equipped standard with a BT30 with system of double spindle touch, with a speed of up to 40,000 rpm and a power of 2.2 - camp 3.7 rpm which reaches in 2 seconds. The system of lubrificado ceramic bearing is carried out with a new system of air / oil which ensures a quieter operation and low noise of the machine in operation.

"Also with regard to the cone of attack - says the director of Maquinser - Matsuura has created a very modern solution, which, while maintaining the rigidity of the system of cone, could also count on a double contact".

This solution, which the market has fully accepted, is to use Classic cones BT30 but when it is needed, to work more precisely, also allows to use the "Plus" type with a double contact cones, either on the conical part, either on the plane. Thanks to this solution throughout the rigidity of the system is transferred unchanged to the tip of the tool.

The storage of tools that is placed laterally to the spindle is composed of a system of wheel with 30 standard tools (in optional solution with 50 tools). For the operation of automatic tools change, spindle nose operates a very limited posting (120 mm) to the area of tooling change, puts the tool, the storage of tools turns and head back into the new tool; Thus the change of tools can be quickly, winning time in the cycle (around 3.8 seconds from chip to chip time); the Exchange takes place outside the working area and this prevents that any litter can contaminate the tools.

The new LX line is intended to give a

new impetus to the sector of the moulds

The LX-1 is equipped with a Fanuc CNC model Matsuura L-Tech 15i, particularly adapted to the management of the high allowable features of linear motors. This CNC is equipped with a range of technological functions arising from the experience of Matsuura. Control of circularity and change in the four critical points of change of the axes, for example, with the ability of interpolarización nanometer (10¯9 m) (system nanoprecisión) and the high accuracy of linear scales, it is able to ensure a very high precision of positioning. With a check of the positions in 0,0001 mm intervals, about all axes positioning is maintained between 0.0002. In this way, the capacity measured in terms of whole process on all three axes also maintains a very high stability.

The system for the disposal of chips has developed with regard to particularly taking into account not only the volume of transported chip (this is semifinishing and finishing work), but also the dimensions of that chip in the mechanization of the temperate materialsform small pins that can be very harmful for its high dispersion. To avoid damage, the guides of the axis "And", to which addresses most of the chip and the litter, they are covered with a double system of coverage in steel, a superior system of "pagoda" and a lower system of pantograph. The latter allows the opening and closing of the coverage and regulates the overlap of the parties. This coverage is linked to the structure of the machine through systems of separation in bronze which allow a low thermal transmission between the continuous movement of the pantografo and the same structure. This system ensures high protection guidelines and especially engines linear, on the other hand are also subject to a slight overpressure of air. A hole in the bottom of the base allows the collection of the chip and the eventual lubricating directing them towards the rear of the machine (in this type of machines the preferred lubricated is normally the atomization).

The standard staffing comprises, on the other hand, a cooling system of the line of the spindle with a post refrigerator by the way in the back of the machine, where the cooling fluid passes through the aluminium structure around the line of the spindle cartridgea protection system for the spindle of overloading, a booth equipped with doors interbloqueadas, coverage and a gateway for the storage of tools.

In options, it is possible to equip the machine of a spindle of 60,000 rpm, a 4th axis for the table, an extractor in a spiral to the shavings of a cooling system of high-pressure spindle, of systems of measurement "in process", systems of control of rupture and length of utensils, a set for functions of the CNC, interpolarizaciones Nurbs and other extras. In the largest version, the model LX-1 which presents X-Y-Z displacement equal to 500 x 500 x 300 mm and a surface of the table equal to 700 x 500 mm, thanks to the possibility of a pallet changing system staffing is possible to mechanise in continuous shifts, with no loss of precision.

"The LX-1 - concludes Ghilardi - it is a machine which by its particular characteristics, an axis X 330 mm, a base structure far more extensive than the area of work, a very expensive materials composition, either from the point of view of the construction", either from the point of view of the mounting, use of the engines on all axis linear, a screw that allows an optimum between the self-indulgent work progress and high cutting speeds, is not generally suitable for all the moldistas. But it is particularly suitable in the machining of small and medium/small, very precise moulds, either as a geometry as a form, i.e., when the economic and technical content of the mould is high.

Typical applications are: mobile telephony, electronics, work of Platinum, the particular complex techniques in plastic molding and construction of parts of precision for children and many other sectors. The references of the industry of moulds are many, also because part of the client there is a high loyalty: who acquired a Matsuura machine 20 years ago, has certainly expanded its number of machines with another machine Matsuura. Finally, some comments about our company. The relationship between Maquinser and Matsuura, mentioned at the beginning, is very effective and concrete.

The objective of Maquinser is put to the customers in terms of success in the industry. The main strengths of the structure are: support to the sales which also deals with the study of the applications; a team dedicated to the training of clients; a network consisting of 10 technical expertise in the development and use of utensils CNC machines. "All these are factors which, placed at the service of high quality machines, place us in the"pool position"to be able to respond adequately to the demands of the most demanding moldistas"