Material bars are made ready for processing on a lateral material storage facility (sloping surface). These are generally bars with round, hexagonal or quadratic outer contours, which may have either hollow or solid cross-sections and which may be made from a wide variety of materials. The bar diameters or key widths are in a range between approx. 1 and 100 mm.
Depending on the area of application of the loading magazine, the length of the bars generally varies between 1,000 and 6,000 mm. In special cases, FMB can also offer customer-specific solutions for other lengths. A fundamental distinction is made between bar loading magazines for single-spindle lathes and ones for multi-spindle lathes.
Loading magazines for single spindle lathes are further differentiated, depending on whether the material bars to be machined are cut down prior to processing to a length not exceeding that of the lathe spindle, or whether the material bars are longer and thus also have to be guided outside the lathe. In the former case they are known as “short bars”, and are fed to the lathe by a short loader. In the latter case they are known as “long bars”, generally between 2,000 and 6,000 mm in length.
The lateral material storage not only holds the bars ready for processing, but also feeds a specified number of bars, in order to ensure the automated production of the required parts with as long an interval as possible between manual interventions by the operator.
From the material storage facility, the material bars are transferred individually into an enclosed or open guide channel, from where they are moved by a pusher device into the spindle or the collet or chuck of the lathe. Once the machining of the part is complete and it has been cut off, the loading magazine moves the material bar forward by the defined length of the part, until the material bar has been fully processed. A new bar is then inserted and the cycle begins again.
In the case of loading magazines for “long bars”, FMB makes a distinction on the basis of the required guidance of the material bar in the loading magazine between machine concepts with an enclosed guide channel, which is flushed with oil and generates a hydrodynamic bearing effect, and an open guide channel, in which the material bars are taken up by guide bushes with ball bearings.
More details about the different loading magazine concepts from FMB can be seen under the relevant product categories.