August Wenzler Maschinenbau works with Demag universal cranes
Two V-type cranes for sensitive assembly work on machine tools
Sensitive load handling – especially in smart tandem mode
Since 1954, August Wenzler Maschinenbau GmbH has developed and manufactured machine tools and been an innovative solution provider for manufacturers of series products. The company builds its highly complex and automated machining centres to customer specifications at its headquarters in Spaichingen, Germany and primarily serves the automotive industry. In addition to its manufacturing operations, August Wenzler, which is part of the Heller Group, provides a broad range of services covering all the needs corresponding to its products – from expert advice and engineering all the way to after-sales service.
At its new workshop for final machine tool assembly, the company needed a handling solution for bulky components that need to be positioned and installed with utmost precision in and on the machines. This was particularly important, as both sub-assemblies weighing several tonnes as well as components vulnerable to vibrations are moved and assembled during production of the machining centres.
The goal was for production personnel to be supported by cranes that would transport the often heavy components and lift them into position for assembly. Accordingly, the customer required smooth and even load transportation and precise material handling while making sure that sensitive components would not sway.
August Wenzler Maschinenbau attaches enormous importance to state-of-the-art workstations and occupational health and safety, meaning that the cranes had to be equipped with user-friendly controls and comprehensive safety features.
Two identical V-type cranes with a load capacity of 6.3 tonnes and a span of 17.65 m travel on a shared runway. The V-type crane design comes with the advantage that its reduced weight exerts a smaller load on the runway and the building structure. Even more importantly, the diaphragm joints reduce vibration and ensure that sensitive sub-assemblies can be transported with added protection. Finally, all travel drives have variable speeds and can be conveniently operated with the Demag DRC-10 radio control system.
The Demag smart SafeControl system monitors all crane functions for safety. Laser sensors continuously measure the distance between the two crane systems and send the corresponding data to the SafeControl system. In addition, the bidirectional remote data link allows for smart tandem operation, enabling crane operators to safely move unwieldy machine components.
The relevant data is shown at all times on the crane via the StatusBoard, and the display on the pendant controller shows the load in 20% increments. Accordingly, crane operators can always see all relevant data at a glance.
The crane trolley’s Demag DualDrive two-wheel drive provides additional traction. This, combined with two-stage final limit switches for long and cross travel, helps to maximize safety when the crane is in operation.
Demag SafeControl ensures that the cranes can operate safely at all times and makes it possible to use them in smart tandem mode. Within this context, SafeControl continuously monitors the positions of both cranes and prevents unwanted collisions. Moreover, the two-stage long and cross-travel limit switches prevent the cranes from running against the limit stops. With two-stage cut-off, the long-travel motion is switched to creep speed by the first limit switch. The second limit switch switches the drives off just before the limit stops are reached and prevents dangerous load sway.
The selector switch on the radio control unit makes it possible to switch between single crane and tandem mode quickly and easily. The smart safety control system monitors all crane functions and brings the cranes to a safe state if there any irregularities.
Crane operators can control the cranes with the Demag DRC-10 radio control system without interruption for up to five days at a time. Demag DRC radio control systems require a mere 2.5 hours to reach full charge, making them an excellent way to maximize efficiency. Current operating statuses of the crane are shown on the LCD display.
Demag V-type girder
The V-type crane revolutionises load handling. Its innovative design featuring tapered diaphragm joints reduces oscillation frequency by 30%, cuts its weight by an average of 17% and doubles its service life to as many as 500,000 changes of load.