06/23/2009

Chinese investment in construction sector generates demand for Schuler forging presses

Over the past few months, many governments around the world have announced huge infrastructure plans as a way to cushion the effects of the economic crisis.  According to the foreign trade experts of Germany Trade and Invest, China’s infrastructure investments via various economic recovery programs amount to around 350 billion dollars.  Some 220 billion dollars of this total are to be channeled into the building sector; over 11 billion into expanding the country’s railway network, 39 billion for road construction and a further 70 billion dollars for hydroelectric power, environmental projects and public facilities.  To support this massive plan, the demand for construction machines in this region is high, and as a result, the Schuler Group is currently installing two forging presses for a Chinese construction machine manufacturer.

Extremely accurate forging presses will produce support rollers and parts for crawler tracks

Shandong Shantui Construction in Jinging is one of China’s largest manufacturers of construction equipment. In 2007, the company prepared for the expanding market with a large-scale investment decision. At this time, the order for two forging presses was awarded to the forming specialists Müller Weingarten, a subsidiary of the Schuler Group. Shandong Shantui Construction aims to use the machines to modernize and expand its production of crawler tracks and support rollers for various construction vehicles.

Schuler’s experts are currently beginning assembly of the two presses and automation equipment. Production is due to start on the new lines in October 2009 and will result in a significant increase in output. “The requirements are particularly high in this field of forging,” explains Herbert Pfeiffer, Head of Project Management for Forging at Müller Weingarten. He adds: “The two new lines will be used to manufacture chain links and deflection rollers for the crawler tracks of construction machines. These parts must be able to withstand tremendous loads. The forging processes must therefore not only be efficient, but also extremely accurate. The two presses were designed and adapted specifically to meet these requirements.”

Automated manufacturing process for chain links more than doubles production rate

The chain links will be produced on a crankshaft forging press. With a press force of 3,500 US tons and a maximum of 40 strokes per minute, the steel blanks are formed into chain links in five stations under one slide. The press includes a mechanical slide and bed ejector, as well as a slug feeder for the automatic feeding of blanks from the induction heater into the press. Inside the press, a servo transfer system handles the automatic transport of parts to the various forming stations. A cooling and lubricating system is integrated into the press to cool and lubricate the dies. It is moved automatically into the die area via the slide after each press stroke.

“This forging process is capable of producing 20 chain links per minute. The product was previously manufactured at a rate of just eight parts per minute,” says Herbert Pfeiffer.

 All in all, Schuler’s experts have developed a machine which is ideally suited to the needs of this forging environment, with low energy consumption and simple operator handling for semi-automatic tool changing. The forming speed of the press in this line is adapted to the specific process and not only guarantees high part quality, but also long tool service life.

Screw press produces track support rollers

The track support rollers, which guide the tracks of the construction vehicles, will be manufactured on the second Schuler line. The screw press with direct drive and a screw diameter of 18 inches boasts an increased press force of up to 3,600 US tons. The direct drive system with AC motor ensures up to 16 strokes per minute. The line also includes two robots for feeding the steel blanks into the press and for removing the formed rollers out of the press and transferring to the deburring press. The press is equipped with a hydraulic slide and bed ejector, while the peripheral equipment of the screw press includes a robot with a die cooling and lubricating device. Both presses feature the Müller Weingarten Forge Control System (MW-FCS). This makes it possible to run the line in all operating modes – such as set-up, die positioning, manual or automatic operation. Users can also select complete blow programs – with individual settings for the number of blows, energy per blow and pauses between blows – and then store them separately for each die.

Customer benefits from Schuler service in China

Of particular importance to Shandong Shantui Construction are the services Schuler provides in China. “Our staff are on site to ensure the smoothest possible installation process. With our own facilities in China, our local presence means we can provide permanent support and service for the customer,” explains Project Manager Herbert Pfeiffer.