Os fusos de esferas retificados, as guias de rolos lineares e os rolamentos de esferas de superprecisão da NSK estão ajudando a IMSA a consolidar sua posição de excelência no campo de máquinas especializadas de perfuração de furos profundos, que são particularmente populares para aplicações de fabricação de moldes no setor automotivo.

A furação profunda é uma operação de usinagem complexa devido à absoluta precisão e produtividade exigida pelo mercado atual, particularmente (mas não exclusivamente) na indústria de fabricação de moldes automotivos. Os moldes utilizados para a fabricação de componentes plásticos de médio e grande porte requerem perfuração profunda para criar dutos de resfriamento longos e precisos, alguns medindo até 1.500 mm e além.

IMSA é uma empresa italiana que se tornou líder mundial em centros de usinagem especializados para furação profunda. Ao longo de mais de 30 anos de actividade, a IMSA introduziu inúmeras inovações técnicas que, além de consolidarem a sua posição, levaram à instalação de mais de 500 máquinas que actualmente operam em Itália e no resto da União Europeia, bem como no Canadá, EUA, Brasil e México. A empresa detém uma quota de mercado particularmente significativa no setor da produção de moldes para automóveis.

Parcerias contribuem para uma história de inovação

IMSA has always been able to anticipate market needs by providing its customers with new concepts capable of making a quantum leap in the performance and productivity of deep-hole drilling. These include its exclusive autofocus system for the optimal movement of steady rests developed as far back as 1996, and the concept of independent axes for drilling and milling, which arrived the following year. In 2000, IMSA unveiled a vertical gantry structure for the column that provides 16 times more rigidity than traditional solutions.

The evolution of IMSA’s deep-hole drilling machines continued with the introduction of a milling head changer, which for the first time made it possible to exchange the gun-drill head without operator intervention. The company also released its ‘Swing on Top’ switching system, which allows both deep-hole drilling and milling operations to use the same spindle.

IMSA has integrated powerful liquid-cooled electro-spindles into its latest top-of-the-range EVO series, both to improve productivity in deep-hole drilling and ensure high-level milling before and after drilling of the mould conditioning circuit.

“Our partners have always played a fundamental role in all of the technological innovations that distinguish our company,” says Marco Colombo, Head of Technical Department at IMSA. “In order to put our design ideas into practice, we use top-quality components that can guarantee the best performance and reliability over time. For example, NSK has always been our point of reference in motion control throughout the evolution of our machines. The availability of optimal-quality NSK bearings, ball screws and linear guides has allowed us to build the highest performance machines in our sector.”

Rotary-tilting table provides mould machining in five axes

One of IMSA’s most recent innovations has been the development of a rotary-tilting table, which allows the machining of moulds in five axes using just one clamping position, further reducing manufacturing time. MF1000-3T EVO, a deep-hole drilling machine for small to medium automotive moulds up to 2.5 tonnes in weight, is the first model to be equipped with this solution.

Colombo explains: “For this specific application we created a single-head machine with one HSK63A electro-spindle [200 Nm], combined with three deep-hole drilling heads featuring automatic head change and an 80-position automatic tool changer. In addition, the MF1000-3T EVO is supported by an automation system of our own design for the two-station pallet changer [expandable to six], which allows the customer to carry out complete machining operations of considerable complexity with minimum downtime and long unmanned cycles.”

Here too, IMSA is using NSK’s latest-generation solutions to achieve the very high performance required, even in a relatively small machine.

“To transform axial movement into rotary movement, we use two 63 mm diameter NSK ZSS series ground ball screws,” says Colombo. “Compared with the ball screws of previous generations, they guarantee greater rigidity and perform better in terms of speed and load capacity. As a result, the machine’s working axes can move at feed rates of up to 30 m/min. This is just one of many examples of how the components we choose in collaboration with NSK’s technical specialists enable us to achieve our ambitious targets.”

Another NSK product family that is extremely important for IMSA-designed machines is RA series roller guides, which represent the ultimate in rigidity, load capacity and precision. Their ‘caged roller’ construction technology ensures smooth and silent running, and prevents the rollers from crossing to totally eliminate the risk of damage or premature failure. The roller guides, together with NSK ball screws, are the heart of a solution that guarantees rigid movement in IMSA’s machines.

Flexibility and customised supplies

The collaboration between IMSA and NSK is long-standing and reinforced by the constant interaction between the Italian company’s designers and the specialists of NSK’s local support team.

“In all these years of cooperation we have seen that NSK’s ball screws are the world’s finest,” states Colombo. “A well-dimensioned ball screw from NSK is practically eternal, so we’re delighted to continue this successful partnership. In addition, we appreciate the company’s ability to be very flexible; local NSK staff are always available to meet our particular needs at short notice. We often order bespoke products, such as custom-length or twin ball screws, which are essential to ensure the best mechanical performance of our gantry structure. We particularly appreciate flexibility in delivery.”

From high-precision ball bearings to roller bearings; from linear guides with automatic lubrication systems to heavy-duty ball screws; there is no product in the NSK catalogue that the designers at IMSA have not carefully considered.

Concludes Colombo: “What’s most important is the common vision of the two companies: to introduce added value to the machines in terms of performance and durability. In this way, we achieve our objective: to meet the expectations of our customers and keep them coming back with any new project their market requires, in the spirit of long-term collaboration.”