Diecasting process technology has been advancing steadily in the past decade, but much of the progress has been overlooked because of the growing market for diecast products. Certainly, that demand has increased, and is contributing to the process developments.
Mainly, the demand is coming from automotive markets, where lighter vehicle designs and alternative fuel technologies have prompted a need for lighter components — lighter engine and drivetrain components, lighter structural elements, and lighter automotive bodies.
All of these factors have promoted developments in high-pressure diecasting process technology. The parts being produced are generally larger and more complex than previously standard HPDC parts, because they frequently incorporate the multiple functional aspects of vehicle design. In addition, more recent HPDC automotive parts formed in aluminum alloys are expected to maintain impact resistance and high yield strength.
Recently, diecasting machine developer Italpresse Gauss announced it is supplying a high-pressure diecasting designed with a closing force of 5,700 metric tons for a German luxury automaker, representing the scale to which the HPDC process has grown on the strength of the recent trends. "Lightweight construction and electric vehicles are driving the demand for ever larger castings, structural components and battery housings, for example," explained an Italpresse representative, Marco Giegold. "Diecasting machine sizes have to keep up with that. Our TF 5700 is the largest toggle-free machine to date, and is ahead of its time digitally, too."
The "toggle free" or TF series of machines was developed and introduced by Italpresse in 2005, with a hydraulic system to drive the press closing action rather than a mechanical process. An initial advantage to hydraulic power is that the machine needs just two platens (not three) to achieve the necessary pressure, which reduces the machine footprint. That point is important because producing larger-dimension parts calls for a higher reliance on automation and handling equipment to tend the HPDC process.
The "toggle-free" is said to be well-suited to the scale of production involved in automotive supply, as well as operations that may require frequent die changes.
Other advantages to the design are the absence a connecting rod system and reaction platen, which reduces the number of parts requiring service. Larger and shorter tie rods give the machine high rigidity, promoting better die closure, which improves casting quality and minimizes scrap material.
The developer also claimed the design is flexible thanks to four independent screws thatmake it possible to offset any geometric imperfections and thermal expansion in the die as product and process conditions change.
The shot process for the TF machines is controlled by the developer's SC 3.0 shot end system, which it explained maintains process consistency and repeatability, ensuring high-quality castings.
The machines are designed to allow easy access to the injection system, to simplify maintenance and promote machine uptime.
Quick die-changing is possible thanks to optional automatic tie-rod removal. And, a fully automated TF machine is possible, with integrated peripheral devices ("… from the furnace to automatic deburring".)
Giegold added that the TF machines' digitalization packages make them ready for diecasters' adoption of advanced data processing, and "open for the connection to customer-specific systems – or to our own digital products."
The TF machines are supplied Italpresse's HMe control package, with advanced data management and diagnostics capabilities for Industry 4.0 compliance.HMe offers real-time storage and analysis of machine and process data, as well as data integration with peripheral and mobile devices. It is Microsoft Windows-based platform, for easy installation and embedded connectivity, including the use of cloud computing and storage. The user interface is designed to present critical machine and process data in dashboards that are understandable and accessible.
The developer also offers an application (AMe) for live remote maintenance and service assistance.