Steinrucken meets customer demand with low-pressure sand casting.

Changing markets require metalcasting facilities to constantly identify ways to meet customer demands. As a metalcasting facility that predominantly deals in aluminum and magnesium permanent mold casting for products ranging from door panels and garden panels to complex cast parts for the automobile industry, Steinrucken, Olsberg-Bruchhausen, Germany, was looking for a way to respond to constant demand for higher quality parts, referred to as "ready-for-use test stand production runs." In response to increasing market demands, the firm sought to offer a wider variety of casting processes with the addition of a low-pressure sand casting.

Michael Steinrucken, president of Steinrucken, met with Kurtz Foundry Machines, Kreuzwertheim, Germany (represented in the U.S. by Kurtz North America, Plymouth, Wis.), to discuss the requirements for a custom-built casting machine. The goal was to achieve casting properties normally attained with permanent mold casting.

The new casting machine would need to cast closed sand molds using low-pressure, feature a clamping system for the sand molds with automatic mold height recognition, and incorporate a furnace-changing concept. The mold size requirement was 47.244 x 47.244 in. (1.2 x 1.2 m) with the possibility of casting 78.74-in. (2-m)-long molds, as well. The molds had to be able to be constructed outside the casting installation, and then conveyed into the system for pouring.

Low-pressure sand casting was not uncharted territory for Kurtz, but the application of sand casting in closed molds was new. Fortunately, this did not present a problem because it called for a combination of low-pressure sand casting in open molds and low-pressure casting in permanent molds.

However, the clamping system for the sand molds presented a challenge because it needed to be designed in such a way that the mold would not be damaged by excess pressure. The normal down-holding pressures of a standard low-pressure permanent mold machine with a steel mold are too great to exert onto a sand mold, which would break or crush under those circumstances. The sand casting machine only needed enough force to keep the sand mold in place. The heights of the various sand molds also had to be recognized, yet firmly secured on the machine. To do this, the machine automatically detects the height of the mold so the downholding force is exerted at the right place.

In addition, a way to build the molds outside the machine had to be found. The casting facility was expecting a projected series of up to 100 pieces. So the machine included a design feature that incorporated changeable mold plates on which the sand molds can be built. The molds are placed on a conveyor in front of and behind the machine and put into and taken out of the machine by hand.

Steinrucken also wanted to have the ability to change furnaces quickly and easily with the new machine. Short reaction times of various alloys had to be accommodated; plus, a second furnace outside the pouring station could be used for melting. This way a higher number of castings could be produced on the same day.

Using a crane and with the help of mechanical centering and changing procedures, the metalcaster can carry out a furnace change quickly using the all the necessary media, which are connected by automatic coupling.

Six months after the order was placed, Kurtz delivered the custom-built and designed casting machine--ready to start production--to Steinrucken.

"We are able to produce parts for pilot production and development very quickly--quicker than with high pressure," Steinrucken said. "The machine operates to our full satisfaction, and a top-class control allows high-quality casting."

Select No. 001 at www.moderncasting.com/info