Fixturing innovations boost productivity

Paul Boughton
The economic recession has served to conceal a major change: the shifting of the production of large series to countries with low labour costs. For many European companies that presents a challenge which can be overcome by targeting investments in production systems at key factors.

Where reducing the set-up times of machine tools is concerned the largest and so far untapped savings potential undoubtedly lies in how rapidly workpieces can be changed in a machine tool.

Modern pallet solutions complete with tooling columns constitute a significant step forward in this area, but many other effective concepts exist for reducing set-up times are available.

One easy improvement is to choose small-size fixturing components that allow the fixture base to accommodate as many workpieces to be machined as possible. The benefits are obvious: more machining minutes per fixture base.

Quick fastening to prevent idle machines

The aim is that all workpiece fastening can be performed as quickly as possible. This is particularly important if the machine has to stand idle when the fastening operation is performed.

Modular systems that can be rapidly adjusted to different types of product are an effective tool especially when fastening rectangular-shaped workpieces.

In modern solutions fine serration is used to ensure the precise positioning of fixed stops. By these means a workpiece of any size can be dependably fastened.

The flexibility of fixturing here refers to the fact that with one fixture as large as possible a proportion of the company's workpieces can be machined.

Dependable fixturing is a vital factor from the perspective of product quality and production process risk management. Less and less errors in production can be tolerated and for this reason a tried and tested fixturing solution:

- Cuts the probability of machine breakdowns.

- Reduces the number of rejects.

- Ensures optimal quality of the end product.

Trends in the design of workholding systems change, but OK-VISE clamps have remained core components of successful workholding systems for 25 years now. They are low-profile clamps operating on the wedge-clamp principle. Only a single thread is needed to fasten the clamp, making it a very versatile clamp concept that can be used on plain plates and T-slot tables as well as plates and tooling columns based on grid solutions.

Low-profile clamps

OK-VISE clamps are available with a variety of jaw types, including machinable jaws which can be adapted to any odd-shaped workpiece. Pull-down effect, which pulls the workpiece against the fixture, is also available in some clamp models.

When bolt fastening is used, the pressing power - which can be as much as 150kN (15tons) - can be easily adjusted simply by adjusting the torque of the fastening bolt.

Enter √ at www.engineerlive.com/ede

Olavi Meriläinen is with OK-VISE Oy, Muurame, Finland. www.ok-vise.com

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