The sharpening specialist VOLLMER has boosted their VHybrid 260 grinding and erosion machine, and now achieves a surface quality of 0.05 μm/Ra (micrometre/average roughness value) when eroding PCD tools (polycrystalline diamond). The process innovation succeeded thanks to the optimisation of the Vpulse EDM Generator.
The optional V@ boost solution is designed for drills or milling cutters as of a diameter of 1.0 millimetre. Such small PCD tools are mainly used in sectors such as automotive construction, medical engineering or the electronics and aerospace sectors.
These days, PCD cutting tools are an essential component for many modern industrial manufacturing procedures. Thanks to their hardness and wear resistance, they are ideal for machining light metals, fibre composites, brittle-hard materials, as well as wood/wood composites. However, sharpening PCD tools is increasingly presenting even experienced manufacturers with great challenges. Especially if tools have to be ground or polished on various functional areas following erosive machining. For this purpose, an additional work step is usually downstreamed, which brings with it an exacting process design.
Generator with adaptive control
The Biberach-based sharpening specialist VOLLMER has now succeeded in significantly improving this eroding process using their VHybrid 260 grinding and erosion machine in one set-up. Thanks to the new performance package for the Vpulse EDM generator, it is possible – for the first time – to reliably achieve a PCD tool surface quality of 0.05 μm/Ra (micrometre/average roughness value) in unmanned loader operation when eroding using the VHybrid 260. These values can be achieved thanks to the use of adaptive control technology together with the familiar innovative yet robust kinematics of the VHybrid 260 in combination with minimal discharge energy levels. This means that the finest of surfaces can be achieved.
The savings in cost-intensive follow-up processes created by this provide the manufacturers of PCD tools with a profitable business, since they reduce the manufacturing costs per tool and increase the quality and durability for the end user. For the future, it will also be possible to manufacture full-head PCD tools costefficiently in the smallest diameter ranges.
The VHybrid 260 joins the party at the AMB
At the AMB 2022 metalworking trade show in Stuttgart, interested parties at the VOLLMER stand can see for themselves how PCD tools are sharpened in one set-up with the VHybrid 260 grinding and erosion machine. The visible result is the reflective surfaces, which are otherwise only possible with time-consuming and cost-intensive grinding work. Thanks to the V@ boost solution, in future, it will be possible to integrate the erosion into the tool manufacture as a complete manufacturing process. Tool manufacturers can use the VHybrid 260 to machine as usual with reliable process management in an unmanned operation.
Eroding and grinding up to 100 percent each time
In general, the VHybrid 260 can be used to grind or erode both carbide and PCD tools up to 100 percent in one set-up. The VHybrid 260 is based on multi-layer machining, which is implemented using two vertically arranged spindles. Here, VOLLMER is using the tried-and-tested technology of its VGrind grinding machine series. With the VHybrid 260, the bottom spindle can be used both for grinding and for eroding, while the top spindle is reserved exclusively for grinding.
Standard and special tools can be flexibly ground and eroded – regardless of whether the blanks consist of carbide, PCD or soldered PCD plates. The machine can be used for tools with diameters of up to 150 mm and lengths of up to 360 mm. The unmanned, round-the-clock machining allows for various automation solutions: This means that the HC4 Plus chain magazine can hold up to 53 HSK tools, for example. In addition, up to eight grinding and eroding wheels, including coolant supply, can be switched fully automatically.
"With our new V@ boost solution, we are enabling tool manufacturers to penetrate the attractive market for small PCD tools, to be part of sectors such as automotive construction, medical engineering or the electronics and aerospace," says Jürgen Hauger, CEO of the VOLLMER GROUP. "Furthermore, the latest booster software is just one step on the path to further process innovations for the VHybrid 260. Th next objective is to also achieve this surface quality for PCD tool with a diameter of less than 1.0 millimetre."