Large Turbine Engine Component Machining for Power Generation

For the production of film cooling holes and shaped diffuser holes in blade and vane segments, the EDBV8 fast hole EDM drilling machine from Makino, Inc. (Mason, OH) is ideally suited for large turbine engine component machining for the power generation market. It is equipped with a 2-axis rotary table for enhanced workpiece positioning. This machine provides blade and vane manufacturers with the flexibility to accommodate a wider range of part sizes for any high volume fast hole EDM drilling application. “The EDBV8 machine provides manufacturers with the speed, flexibility and reliability to effectively produce a wide range of hole shapes and sizes with a single electrode process,” said Brian Pfluger, the EDM product line manager at Makino. “This approach significantly reduces tooling costs while improving cycle time, part quality and production efficiency. Its uniquely designed tooling system integrates the electrode and die guide into a common assembly for quick and reliable automated exchanges, and provides programmable control over electrodes and electrode diameter size changes.”

The EDBV8 offers X-axis, Y-axis, Z-axis and W-axis travels of 800 mm, 600 mm, 750 mm and 500 mm (31.5 in, 23.6 in, 29.5 in and 19.7 in), respectively. The machine is also equipped with a 2-axis rotary table that can accommodate a maximum workpiece size of 500 mm (19.7 in) diameter by 635 mm (24.96 in) long, and a maximum payload of 150 kg (330 lb). Its rotating C-axis head features an EROWA compact chuck that enables automatic changing of electrode diameters from 0.2 mm (0.008 in) up to 6.0 mm (0.236 in) with rotation speeds up to 1,000 rpm. The EDBV8 uses a rigid guide-arm assembly to hold, locate and support the die guide, which can be alternately used as a programmable axis (W-axis) that runs parallel to the Z-axis. An integrated “middle guide” system is also contained within the W-axis and is used with long small-diameter electrodes to prevent whipping, bending and vibration of the electrode. Additionally, the middle-guide “fingers” automatically retract as the electrode tube reduces in length, maximizing the productive useful length of the consumed electrode.

“The need for EDM drilling with advanced capabilities in blade and vane components has grown substantially due to new production requirements, as turbine engine manufacturers strive to improve engine performance and reduce fuel consumption,” explained Pfluger. “The EDBV8 fulfills these needs by providing a solution to larger, heavier workpieces while improving productivity and part quality.” The EDBV8 features improved flushing through fully submerged machining, greater machining stability and part accuracy, and faster cycle times with the equipped 10 MPa (1,450 psi) flushing capability for higher productivity of deep-hole features. The machine also contains a fast response break-through detection circuit to prevent back-striking or back-wall impingement (damage to the inner cavity) during blade and vane cavity wall penetration. This highly sensitive breakthrough detection circuit, which uses a combination of different adaptive process-monitoring techniques, is accomplished while delivering maximum speeds.

An advanced EDM generator technology produces excellent metallurgical quality and integrity on high-nickel alloys such as Inconel®. Reliable and repeatable machining results are maintained using the machine’s on-board water quality control system that consists of a filtration system to clean the water, a deionization system to control water conductivity, and a chiller unit to maintain the water temperature at the same level as the machine casting. For unattended burning of varying film cooling hole diameters, the EDBV8 features automatic tool change (ATC) and automatic guide change (AGC) systems. The patented tooling system combines the electrode holder and die guide together into a common assembly, providing enhanced reliability with simple and precise automated exchanges. Together, these features enable ATC and AGC exchanges in less than one minute, and they offer a unique combination of process flexibility while minimizing non-value added machine motions.

The EDBV8 employs several proven software technologies for fine-hole sinker EDM machining. Its Model Plan system is integrated into the controller, providing user-friendly input screens with direct G-code and M-code programming formats. An electrode length management system provides electrode wear tracking and automatically exchanges electrodes when lengths become too short. The controller contains several canned cycles for hole drilling and simple diffuser shape machining, and custom G-code profiles can also be imported and easily used in the machine. The EDBV8 has been designed for easy operation, and it offers the operator unparalleled access to the work tank with its three-sided rise-and-fall work tank. The EDBV8 is also capable of on-machine probing to determine workpiece locations and offsets. Electrical touch-sensing probing or a conventional mechanical touch probe can be used to capture location data points. The standard configuration of the EDBV8 includes a 24-station tool carousel and 24 tool assemblies to fully stock the machine for maximum productivity.

Makino also brings Internet of Things (IoT) connectivity and efficiency to EDM processing with their HyperConnect machine networking application that facilitates machine-to-machine and machine-to-PC virtual connectivity for improved efficiencies. HyperConnect offers a suite of IoT applications for EDMs that enhances user experience and efficiency and reduces machine downtime. Available on all EDMs equipped with Hyper-i control systems, this networking application enables shop managers and operators to easily monitor and control EDM processes from any PC, smart device or other Hyper-i control systems on the network. “EDM operators are already faced with too much on the shop floor. The last thing we want them doing is running back and forth between machines and office spaces,” noted Pfluger. “HyperConnect provides these operators with accessibility to everything they need to maximize efficiency, whether they are standing at the machine, sitting in their office or working remotely.”

The HyperConnect suite boasts four primary connectivity features for shop personnel to easily monitor, plan and troubleshoot their EDM operations:

• EDM Mail relays machine status information to operators via email during unattended operation to help reduce downtime and support multitasking abilities. It can deliver periodic, timed interval updates of a machine’s operating conditions, or alert operators of a machine stoppage at any hour.
• The Machine Viewer is an application that permits networked access to the Hyper-i control NC operation screens, allowing operators to remotely view the machine control and process information from any office environment PC or enabled smart device.
• The Machine-to-Machine Viewer feature gives operators remote access to view and control a networked Hyper-i EDM from another Hyper-i machine, preventing unnecessary foot traffic across the shop floor.
• With the PC Viewer function, operators can achieve greater productivity with remote access to all software on a networked PC directly via the Hyper-i control and includes accessibility to any CAD/CAM software, specialized shop tracking software and Microsoft Office applications.

EDM Mail and PC Viewer functions are the most commonly utilized applications. EDM Mail is used to maximize unattended operation, whereas operators use the PC Viewer to eliminate a substantial amount of non-production motion. The collective capabilities of the HyperConnect communications suite unleash next-level IoT networking and machine monitoring and deliver the tools that empower manufacturers with greater flexibility and productivity.

Makino, Inc., 7680 Innovation Way, Mason, OH 45040-8003, 513-573-7200, Fax: 513-573-7360, www.makino.com.