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Handling Hot and Heavy Loads

March 25, 2006
With a state-of-the-art manipulator, a foundry worker seated in a comfortable control cab can handle heavy loads and be protected from a hot, noisy, and dusty environment.

Higher productivity for the metalcasting industry was a goal for Henschel Industrietechnik GmbH when it designed the Andromat AMX manipulator to handle castings weighing up to 2,000 kg. The AMX was introduced to North American foundries and diecasters in 2002 by it’s American subsidiary, Henschel America Inc.

The manipulator system can be operated by a foundry worker to lift hot, heavy castings and manipulate them, all the while seated in a comfortable control cab that protects him from heat, noise, and dust. Many buyers of the system report that operating the Andromat becomes one of the most sought after places to work in a foundry.

Using one hand to operate the master arm, the operator typically can perform up to 500 lifts per hour, handling weights from a few pounds up to 4,400 lb. One foundry customer reports being able to make as many as 700 lifts per hour.

Working principle

The Andromat works with a “master-slave” relationship between the working (slave) arm and the control (master) arm inside the control cabin. Controlling the positioning movements of the master arm requires no wrist movements by the operator. Each movement performed by the master arm (inside the cabin) transmits to a movement on the working arm (the slave arm outside the cabin). Once the working arm is in position, the operator controls movements of its gripper by operating a “fighter pilot” grip attached to the master arm.

The gripper on the working arm is designed for picking up and handling castings as an alternative to for performing this operation manually.

The gripper position movements include yaw (left and right rotation of the positioner), pitch (tilting the grip-per unit up and down), and roll (the unlimited rotation of the gripper fingers). The grippers themselves can open and close or stop anywhere in between the fully closed or open positions. The speed at which the gripper opens and closes and the holding pressure are also fully adjustable for different parts.

Because all of these control actions are performed with only one hand, the master arm functions like an extension of the operator’s arm. An operator typically can learn to operate the Andromat in as little as one hour, according to Henschel.

One of the features is the ability to rotate the AMX’s wrist through 360°. This enables the operator to complete any turning movement without having to bother about initial angle position and possible reversal and re-gripping operations.

Redesigned for today
Henschel has produced manipulators since 1967, and has nearly 500 systems operating worldwide. As they worked to satisfy the current market’s requirements, company engineers completely redesigned the Andromat manipulator system. They wanted “to further enhance robustness, ease of maintenance, and ergonomics while preserving key advantages such as dynamism of motion, precision and sensitivity.”

Numerous improvements were made in order to meet the key objectives. All bearings in the base machine as well as in the arm were designed for superior robustness. The base machine was fitted exclusively with the latest generation of heavy-duty, low-maintenance, self-aligning roller bearings.

Much attention has been paid to protecting all bearings from the intrusion of dirt and moisture. As one example, the ball-turning joint of the main turning axis (azimuth) has been fitted with a labyrinth seal.

In addition, all axle diameters were increased, and protective covers were used throughout. All parts subjected to bending strains were redesigned to adapt to the real strain profile.

Another design objective was to make maintenance easier to perform. For that purpose, lubricating points were combined wherever possible. Furthermore, the lubricating nipples were grouped at easily accessible key maintenance locations.

Optimizing the layout of the ducts for the hydraulic cylinder of the gripper was important, reducing maintenance expenditures in this particularly strained area. A specific layout detail already proven with the previous Andromat series is a separate bypass controlled throughput the filtration and cooling circuit, which provides for thermal stabilization of the hydraulic liquid. Its improved quality extends the service life of the hydraulic actuators.

For the control section, the reliable NC control system was retained, as well as the combination of the control circuits for the azimuth, shoulder, and elbow joints on a single printed circuit board. A special service operation mode greatly facilitates failure diagnostics.

The Andromat can be delivered pre-wired to accept additional controls required by the particular installation. It can be mounted easily for stationary operation, or on rails to accommodate many different operations with one unit.

Control cab
Henschel engineers also worked to improve the ergonomics for the operator. The air-conditioning and fresh-air supply system offered as standard equipment with previous models was enhanced with the addition of a dust-filtering unit “decisively improving the working conditions.” The cockpit is insulated from heat and noise. In addition, special metal/rubber components were installed to dampen low-frequency vibrations that could be uncomforatble for the operator. Large glass panels ensures optimized viewing from the control seat.

The net result is a control cab that meets the most stringent government safety and health regulations.

Henschel claims that the control system is easy to learn. During a process testing session, a new operator is instructed on the capabilities and the controls and is invited to drive the machine. “We’ve had customers practice by picking up and placing sample parts that weigh up to 600 lb. and later pick up and pour a can of soda into a plastic cup” says Dale Christel, sales manager for Henschel America Inc. “During one Andromat demonstration the operator closed a match box with a 1,200-lb casting without crushing the box. During a recent trade show, a neophyte operator even lit a match with the Andromat.”

When an Andromat is installed, lifting injuries are eliminated because the machine does all of the lifting, turning, and moving. Also, fatigue is no longera concern since the operator can continue to operate the Andromat at the same rate all day long.

From the safe, quiet, and air-conditioned cabin, an operator effortlessly picks up and places castings that otherwise would be handled only the strongest employees.

KUKA Selects Two New System Partners

KUKA Robotics Corp. has signed C.M.H. Manufacturing, Lubbock, TX, as one of its newest system partners. C.M.H. specializes in on aluminum tilt-pour gravity diecasting equipment, and produces the HALL line of foundry equipment. It also offers a full line of casting machines, rotary tables, and peripheral work-cell support equipment designed around the tilt-pour principle.

At the same time, KUKA named Waltonen Engineering Inc. of Warren, MI as a new system partner. Waltonen Engineering is a service, integration, design, and resource provider to automotive manufacturers, Tier One automotive suppliers, defense contract suppliers, appliance manufacturers, and product manufacturers.

KUKA has been proceeding with a North American expansion, and with its new system partners it will be delivering high-performance automation to the diecasting and automotive industries.

According to Joe Campbell, director of strategic alliances for KUKA Robotics, “Both of our newest system partners are highly successful integrators providing quality automation solutions to their customers who range across multiple industries. We believe that KUKA’s robot products and technology will not only enhance their offerings but allow us to together develop new and innovative solutions for the industries they work with.”

“Automation is key in the diecasting industry with the manufacturer’s high production volumes and stringent safety requirements,” said C.M.H. president John Hall.