Product category:
Rotary and linear transfer machines
News Release from: Mikron Machining Technology | Subject: Linear, rotary transfer machines, systems
Edited by the Manufacturingtalk Editorial
Team on 19 April 2007
Machined parts produced in batches or
volume
Over the last few years a Swiss machine tool company has restructured into a 'solution provider' involving small to medium batch work to producing parts on the fastest rotary transfer machines.
To Mikron Machining Technology, machine tool building is no longer the focal point of the business but the means to an objective that provides a production solution to its customers Over the last few years the company has progressively restructured to become a solution provider not only to create a production solution involving small to medium batch work right through to producing parts on the fastest rotary transfer machine in the world, but also to work very closely with customers
This article was originally published on Manufacturingtalk on 9 Oct 2001 at 8.00am (UK)
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With the new Multifast modular machining system, Mikron has revolutionised the high volume rotary transfer machine.
Rotary indexer is claimed to be world's fastest
Claiming to being the world's fastest rotary special purpose machine tool for components up to 32mm diameter, a 24-station design is able to machine up to 500 components/min.
As a result the company is bringing greater freedom to customers' design and development engineering teams which is enabling them to respond to ever-tightening legislation and market forces.
To stay competitive in business, the likes of automotive hydraulics and pneumatics, fuel injection, medical, electronic and even high class watchmakers are responding to legislation and market pressures such as fuel economy, improved performance, higher quality and ever smaller, more intricate design.
Of course, factors such as a lower price and ever-shorter time scales to market are almost taken as read today.
Further reading
Linear transfer machines short batches quicker
Linear transfer machining system performs 5.1/2-face machining and combines simultaneous 5-axis machining with a productivity rate some 47% higher than normal machining centres.
Rotary transfer machine accuracies raised
Rotary transfer machine enables higher levels of accuracy to be met by combining production sequences into a 'single-hit' cycle for large batch, medium batches of families of components.
World's fastest trotary transfer machine claimed
Producing the world's fastest rotary transfer machine able to produce parts at a rate up to 500/minute, Mikron has on offer a wide range of modular rotary and linear transfer systems.
However, manufacturing industry also has to come to terms with the shortage of skills which means that machine tool and tooling suppliers have to take greater responsibility.
This in turn increases the development risk when being innovative to engineering a solution to support rapidly advancing product development.
There is no time today for protracted design, development, consultation, drawn-out production engineering, plant purchase and commissioning.
Quite often the term 'simultaneous engineering' is being put in to practice by the Agno, Switzerland based company working alongside the forward thinking requirements of customers and to such an extent it has even involved building production machines at the product development stage.
As components become so complex, they cannot often be machined in any other practical way even when producing test samples.
And, as a result the company has had to build into its machine tool structure the flexibility to modify the application as development of the component advances.
According to Markus Schnyder: "The machine tool has always been the means to provide a production solution, but today the machine tool builder has to be at the very forefront of production technology to create new levels of freedom demanded by the product designer.
As such, the industrial trend of reducing the number of parts in an assembly, by combining multiple parts into one that is more complex, improving performance with tighter tolerances and surface finish, and the use of more difficult to machine materials is now common but it requires a machine tool supplier that is a true solution provider." In turn, he maintains production demands for smaller batches, fast changeover, more consistent levels of quality, higher machine utilisation, shorter lead times and minimal stock levels present a whole new set of problems to the machine tool builder.
And today, production management does not want rows of machine tools - it wants compact, single-cycle machines that can combine all processes, even hard machining including precise and consistent deburring taking the manual element out of the process.
Whenever possible, included in the single operation process has to be inspection, part qualification and sometimes assembly that put ever greater emphases on the quality and consistency of the machining process.
Amongst its worldwide success in various sectors of industry with 7,000 machine installations in 1,000 customers, Mikron Machining Technology has become a world-leader in the production of fuel injection equipment.
This applies right across the board from small batch with its very flexible, re-toolable Multistep XS linear transfer machine to its high production Multistar laying claim to being the fastest rotary transfer machine in the world and Multifactor, the high precision mechanical/CNC machine.
To this portfolio of machines it has now added the latest, highly flexible, super accurate Mikron NRG-50 12-station rotary transfer machine.
All these machines have been developed and have combined a host of different processes including turning, milling drilling, broaching, honing, deburring and inspection as well as sub assembly into a highly efficient single cycle.
Building in this capability has been very timely for the Swiss company because in the last few years, the demand for this level of technology has exploded out of fuel injection across other sectors such as power steering, air conditioning, hydraulic and pneumatics, security, telecoms and even into the medical sector.
According to Schnyder: "All these industries now face the same demands and because Mikron Machining Technology has its own highly capable tooling company, Mikron Tool, we are able to combine two advanced solution providers of machine and tooling as a package under one roof." Schnyder views this capability as a distinct advantage because companies are changing the materials they specify - to tougher stainless and alloy steels.
Forgings, stampings and castings are being replaced with sintered parts and more parts are now produced from bar in a single cycle as lean manufacturing productivity is pursued.
All these basic changes heavily influence the choice of machine type, how the part is held and tooling - get this wrong and a multi-million project can be held to ransom.
To meet these single cycle processes Mikron's most recent machine development had to break the mould and move into new levels of flexibility to its basic concept.
Without this clean sheet of paper design application engineering would not be able to mix and match the various cutting technologies within in a very stable production platform.
The 12-station, 140-axis, Mikron NRG-50 is able to perform machining on all six faces of component and have up to 96 tools on board with up to 30 tools cutting simultaneously.
But this produces a lot of swarf.
With the high accuracy capability of the machine, which is internally air conditioned for process stability, chips have to be quickly evacuated, so swarf management was another important factor in the design and development of the machine.
To any production engineer the jig borer with a good operator is still the pinnacle of accurate machining on a single component.
But to achieve the same level of precision involving a number of holes and features produced completely burr free to high levels of consistency over a large batch is a different ball game.
This was clearly the area that the Mikron NRG-50 was developed to accommodate.
Due to the inherent accuracy of the new machine's concept, Mikron Machining Technology is then able to exploit its application engineering expertise.
So in a single machine process, customers are benefiting from cycles that are able to include 5-axis interpolation, hard milling, hard turning, grinding, thread milling with automatic offset correction to accommodate tool wear, high frequency milling, deep hole and gundrilling using up to 200 bar pressure.
Most important is that in-process deburring of the component can be included within the single production cycle.
As Alain Bulsson, chief of Mikron's Quotation Department describes, it is becoming a growing requirement for features of a component to include special internal recess profiles in holes as small as 2mm diameter.
Worse still, these recesses have be to high orders of tolerance and even concentricity.
Mikron Machining Technology is now able to interpolate these features using special recessing heads and, in certain applications, has even generated recesses in 2mm and 3mm holes and this has even involved off-centre part rotation.
He explains: "We have had to turn eccentrics by rotating the component at 300 to 400 rev/min and rotate the cutting tool at high speeds of 20,000 rev/min, in order to enable the concentricity tolerance applied to be achieved." Such is the involvement of modern technology that finite element analysis has even been applied to critical components, to determine the level of secure clamping required while preventing any distortion.
He described how the engineering involved with cutting tools is now so critical and can be up to a tenth of the machine project cost.
It is not unusual to develop five different tools at the same time in order to obtain the level of perfection and precision required.
"It's no longer just knowledge and experience, we are applying all the technologies and engineering software available to obtain and then perfect a production solution," he said.
And to add to the burden, customers are becoming so strict with process control that SPC is rejected against the preference for 100% inspection and that has to be performed in-cycle, whenever possible.
Giovanni Zanot, chief of Mikron's Multistar Quotation Department, explains that deep hole drilling of holes as small as 0.8mm and up to 15 times diameter to depth ratio is being performed on the Mikron Multistar CX24.
This machine is mechanically driven and can now combine the flexibility of CNC in order to change process parameters.
Mikron is also using power monitoring checking for wear on drills as small as 0.9mm diameter on steel because consistency of production is so important.
On holes between 0.3mm and 0.5mm a mechanical in-process probe is used.
Here he describes the advantages of Mikron Tool's CrazyDrill which has the capability to drill at far higher penetration rates than normal carbide drills.
He said: "This not only reduces cycle time but aids monitoring." He then gave a prime example on the Multistar machine producing needles for the medical industry at a rate of 120 parts/min.
Parts are made two per cycle and the holes drilled 0.3mm diameter by 1.5mm deep while in the same cycle the needle is faced and chamfered.
"Any stoppage of the process would cause serious problems against production schedules," he maintained, "So application engineering and consistency of production is so important it is built into the process from 'day one'." As higher accuracy and consistency is built into machine design in conjunction with tooling development, even more common now is the demand by component designers to specify precisely the exit position of a through hole and even more difficult, the internal intersection of small holes within a component.
Adding to the problem for the application engineering is the machining process which can often involve the very intricate interpolation of axes to deburr the elliptical shaped breakthrough of one hole into the other within the cycle.
As an example, a special component for high pressure fuel injection produced out of nickel chrome steel on the Mikron Multistep linear transfer machine for pilot production that was followed by full production on a Multifactor machine.
The component has a 2.2mm diameter hole 18mm deep inclined at 30 deg with a 1.8 mm diameter hole simultaneously drilled from the opposite end some 25 mm deep to break into the first hole.
The surface finish requirement within the holes is 3.2 micron Ra produced by titanium coated carbide grindrill with a special drill point development.
Both holes are drilled from an end mill pilot hole to half the drill diameter depth to provide the start to a positional tolerance of 0.1mm without a drill bush.
As part of the cycle, the breakthrough requires a precise and consistent deburr achieved by interpolating a tool around the elliptical shape hole at the bottom of the 2.2mm diameter hole.
As Schnyder recounted, the move to being a solutions provider is not without risk and cost due to investment in people and development: "But the rewards are clear to see - a good working relationship and trust with customers.
As we are being involved at early stages of a project this also leads to a level of expertise that few companies in the world could match," he maintained.
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