Pallet changes are very similar to tool changers, but a machine bed is employed instead of the tools. The design allows multiple fixtures on the bed and is extremely efficient. The most commonly used pallet changers are the automatic pallet changers (APC), which are mostly used for CNC machine tools. They are capable of holding the job in two stations, one of which is where the machining takes place, and the other allows other work pieces to be clamped.
There are three primary types of pallet changers in many CNC machine tools: manual, automatic and robotic.
In this system, operators are required to load and unload pallets manually. Raw or finished parts from a docking station is located and mounted on top of the machine table. As the name implies, this type of pallet changer is the least automated of the three. However, it can still help reducing downtime.
Automatic pallet changers employ an automated system built into the machine which allows the machine to function by itself. However, automatic pallet changers are not actually fully automated in and out. Human intervention is still required for the loading and unload of parts at the pallet station. We’ll elaborate more about the automatic pallet changers in the next section.
As the name suggests, a robot is utilized to load and unload pallets. A robot is usually capable of handling multiple machines, achieving a fully automated pallet changing system. However, this type of system is the most expensive option among the three types of pallet changers, while not necessarily being the most pragmatic system from a cost-effectiveness perspective. But that is not to say that it cannot be made more cost-effective prospectively as technology advances with time. This type of system is often used in locations where labor costs are high or skilled manpower is scarce.
Following the above, we feel the need to elaborate more about the automatic type of pallet changers because it may just be the most cost-effective option as of now. There are two main types of automatic pallet changers:
A shuttle type automatic pallet changers leave the pallet with parts inside of a machine on rails upon completion. A second pallet is then inserted into the machine. Although this type of automatic pallet changers can still be found in larger CNC machining centers, they are considered to be less efficient and relatively more obsolete.
A swing type automatic pallet changer lifts up the pallet with finished part along with the pallet that holds the raw parts. The pallets are then rotated 180 degrees and placed onto a rotary table. Meanwhile, the first pallet is also positioned on the load and unloading station. The simultaneous lifting mechanism allows saving time and improving efficiency, a more reliable alternative than the shuttle type automatic pallet changers overall. Swing type automatic pallet changers provide smoother changer-overs as well.
Automatic pallet changers typically employ either servomotors or hydraulic pistons for the lifting job. Four location points protect the rotation accuracy and position of the table. This significantly increases the versatility and accuracy of the machining process. Besides the above described, other benefits of automatic pallet changers include:
● The speed of change-over of a new part is greatly improved, which can be completed in a matter of seconds.
● Thanks to the continuous machining processes, the duration of inefficient manufacturing can be reduced greatly, as the simultaneous operation setup can make the machining processes very productive.
● The need for human intervention is greatly reduced. Simple press of a button on the CNC console will hugely simplify the pallet changing process.
● A single pallet changer can be deployed for multiple functions. It allows the flexibility to machine the same part repeatedly, while setting up the machine to manufacture other parts on the same pallet.
● The highly automated mechanism reduces operator-driven processes. Pallets can be changed repeatedly and automatically.
● Oversight is not always required as the machine can be operated unmanned for a long period of time.
● Operator errors can be minimized as manual intervention is minimized as well.
● Better ROI for the machine can be achieved.
● Save the time lost from setting up for recurring part orders. Once a repeat order is received, the production line can be resumed quickly.
IMTS Exhibition includes manufacturers from around the world. Send us a message with your requirements and our IMTS Experts will happily help you with your questions.
You can see all Pallet Changers categories