Optimized systems for picks and toolholders
Toolholders are highly stressed components. Almost the entire engine power is converted into cutting performance via the toolholders. When cutting through extremely hard materials, a toolholder must withstand up to five million load cycles during its service life and guarantee optimum rotation of the picks. That is why Wirtgen engineers attach particular importance to using extremely wear-resistant materials and optimally designed toolholder systems.
Wirtgen – setting standards in toolholder systems
Instead of welding the toolholders onto the drum as in older machines, Wirtgen’s concept was to develop holders which could be replaced quickly and easily. The first generation of Wirtgen quick-change toolholders was ready for series production in 1992 and ensured that worn or damaged toolholders could be replaced in a matter of minutes: on site and without requiring any cut-off or welding machines. The cash value of this advantage was immediately appreciated by the contractors. In addition to being easy to replace, the Wirtgen quick-change toolholder systems are characterized by a long service life, thanks to the elimination of welds and the use of high-quality materials. The success of Wirtgen’s unique quick-change toolholder systems is due not only to the detailed theoretical analysis and computer simulations, but also to exhaustive practical tests by customers on innumerable sites and in extreme special jobs.
Top quality manufacturing
The operating costs of road milling machines and recyclers are largely determined by the service life of the tools subject to wear, meaning the bits and the toolholders. Consequently, these parts must meet the highest quality requirements. Manufacturing by the forging method makes it possible to process quality materials at relatively low cost and achieve extremely high component strengths. Tight tolerances are maintained by subsequent machining to make the precision components required for milling applications such as fine milling. Subsequent heat treatment and hardening of the toolholders is of critical importance. Special methods are used for this step as well, in order to obtain high hardness for low wear, and the necessary toughness. Only in this way can a long service life be achieved under the highly dynamic loads generated by the milling process.
Cutter Drums
HT11 "Type 11 " Quick-Change Toolholders
Long-Life Ejectors
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Wirtgen's quick-change toolholder systems (HT11 shown here) set new standards for quick bit changes and accurate positioning of the toolholders: on-site replacement is a simple matter.
Forging process for the upper part of the quick-change toolholder.
High-precision, automatic machining of the upper part of the quick-change toolholder.
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