New cutting tools for the railway sector
- Published: June 27, 2018
The railway industry is one of the main consumers of cutting tools and Iscar is increasing its role as a supplier of complex projects for this key sector.
These incorporate essential elements to fulfil the need for layout solutions, efficient productivity, and a reduction in machining time and costs – all demanding a large variety of both standard and tailor-made solutions.
Machining railway parts represents a challenge for manufacturers and cutting tool producers alike, who must contend with a host of constraints - such as the relatively large workpieces, complex structures, and complicated final machined profile - along with the need to remove a large volume of material, ensure predictable tool life, and avoid high maintenance costs.
When selecting the correct tools and inserts for each job, certain parameters need to be taken into consideration, for example the type of material to be machined, the condition of the part, the available machine tool, its condition and power characteristics, clamping fixtures etc.
A central factor in optimal tool development is the creation of a virtual manufacturing environment that simulates machining processes and cutting conditions, to ensure that the tools produced will overcome material and manufacturing limitations and that they will provide the best solutions to the specific needs of railway parts producers.
As an example of this dynamic, it is useful to consider how new tools and processes are adapted to machine bogie components and switchers. The bogie frame is utilized in each of the three main categories in the railway sector: urban transit rail, passenger rail, and freight rail. The switcher is one of the most common parts produced, with typical switchers including crossover, switch diamond, and three-way switch.
Many operations for railway part machining involve rotating tools, especially for milling and drilling functions.
In milling, due to the high volume of removed material, conical and profile indexable extended flute cutters are used. The cutters with tangentially clamped inserts feature better possibilities for improving tool strength and ensuring higher tooth density that result in increased productivity. In many cases milling the railway parts requires long-reach tools with different overhang. Modular shell mill design configuration offers a flexible and economical alternative to large-size extended flute cutters with integral body (integral-type design).
T490 – A modular solution
Extended flute shell mills
The combinations of the base units and extensions ensure a variety of extended flute shell mills with different cutting lengths. The modular extended flute assembly possesses another advantage in improving operations. As the first-row inserts in extended flute cutters, which are located near a cutter face, are involved not only in side milling but also in face milling, they experience harder loading and their wear is more intense compared with the other inserts of the cutter. In integral-type cutters, a sudden breakage of a first-row insert can cause serious damage to the cutter and even render it inoperable. In the modular assembly, each damaged insert can be replaced individually, which enables efficient operation and extended tool life.
All the new cutters are designed with coolant through to extend tool life and improve chip evacuation in problematic areas such as slotting and deep shouldering. This is especially valuable for tangential clamping as the special profile extended flute cutters ensure a reduction in machining time.
In some cases, the profile in the switcher can be machined in a single pass, and in other cases it is necessary to divide the machining into several passes to produce the right profile and diameter with the correct dimensions.
The newly introduced T890 line represents a range of face mill cutters for rough and semi finish machining that carry tangentially clamped inserts with eight cutting edges, intended for facing and shouldering operations in the switchers and bogie frames. The inserts feature different cutting geometry, designed for machining various engineering materials.
FFQ4 for high feed machining
A new family of high feed mills that carry square single-sided inserts with four cutting edges, the FFQ4, is designed to reduce cutting forces when used on low power machines or long overhang applications. The cutters are available in different design configurations: shell mill in 40 up to 100 mm diameters, and end mills and replaceable milling heads in smaller diameters. The cutters are intended for roughing operations, such as machining plane surfaces, cavities and pockets, including ramping by line and helix.
Old traditional bridge-type machines sometimes require high overhang and the drills often need to operate in conditions of reduced rigidity.
The new Sumocham drills with exchangeable drill heads, cylindrical shank and internal coolant holes enable high feed drilling, high accuracy and good surface finish.
Exchangeable ICP-type drill heads are recommended for carbon and alloy steel (ISO P material group), commonly used in producing railway components, and have already received good marks in drilling operations in producing bogie frames.
Combined drills enable users to perform drilling and chamfering operations with the use of the same tool. Manufactured in different diameters, cutting depths and overhangs, the design of the drills facilitates an increase in cutting range conditions and a reduction both in cycle time and in the number of drills involved in the process.
The railway industry is a large consumer of special (tailor-made) drills. In many cases applying special drills ensures minimizing tool overhang, increasing durability of a drill body and utilizing a single tool for several operations. Iscar proposes a variety of special drill solutions for this sector, in particular for connections between the rails and the switchers, which result in significant reductions in machining costs.