February 2021 Volume 3

AUTOMATION

Multi-Coil Automation Automated bar end heating system utilizing a multi-coil configuration (shown in Figure 8) are generally used to heat various diameters and heat lengths for an upsetting process. The system utilizes a multi-axis robot to load and unload bars on the heating fixture. As the robot loads the bar onto the heating fixture, it shuttles the bar into the coil to locate the proper heat length. Once the heating cycle is complete, the robot will pull the heated bar out of the induction heating coil and transfer it to an upsetter. The six axis robot completes all automation processes. Another style of bar end heating system using multiple coils is a vertical type system as shown in Figure 11. The systems used multiple coils in series orientated vertically to a heat billets standing up on end. The system used robots to load the billets in each coil by setting them on end onto a specially designed pedestal. Once loaded, all the billets are lowered into the coil for heating. The system utilized a servo-controlled lift/ lower mechanism to locate the billets in the coil at the proper heat length. The position of the billets were controlled at the operator HMI and could be adjusted during the heating cycle to fine tune the heat length. Once heated, the billets are raised out of the coil and unloaded by a second robot. By allowing control over the position of the part in the coil, the operator can adjust the coil overlap to control the temperature on the tip of the billet.

Figure 9. Automated index conveyor and multi-position induction coils. Systems that use an indexing conveyor can move parts through a channel type induction heating coil in a steady motion (as shown in Figure 10). A channel type bar end heating system allows for continuous indexing of bars through the channel coil during heating. It permits automation integration at both infeed and extraction of bars. The channel type bar end heating process enables a faster cycle time than any other type of bar end heating system process and is a typical type of bar end heating system optimized for short heat lengths on long bars.

Figure 11. An Automated Billet Feeding System takes random loaded rings from a floor mounted hopper and elevates them via a cleated belt, oriented in a continuous diameter-to-diameter stream and discharged flat into part handling system. Automation Configurations Solutions for bar-end heating that use multiple types of automation (as shown in Figure 9), are a more complex. The system starts with an automated index conveyor to control the process cycle time and position the tubes for end heating. Once the tubes are in position, the induction heating coils are shuttled over the tubes using servo controlled shuttle tables. The servo controls enable fine-tuning of the heat position before and during the heating process. All setup is controlled from the main operation human machine interface (HMI) for total automated control function.

Figure 10. Automated indexing conveyor and induction channel coil

Vertical Heating of Pucks and Rings Automation Not all billets are billets at all. Some are round or rectangular, while others can be pre-formed rings or shaped like pucks. Consider a high carbon steel ring blank with a diameter 3-times as large as its height requiring a 6-8 parts per minute cycle time. Moving these parts horizontally (diameter to diameter) can cause the induction field to overheat the ring's sides and create a delta temperature differential on the part too large for high carbon steel. Instead, heating the rings in a vertical orientation, stack like, (as shown in Figure 11), allows for current to flow around the circumference of the ring for more efficient heating and better temperature uniformity.

FIA MAGAZINE | FEBRUARY 2021 36