The flexible multi-tray manufacturing system achieves its core objective of rapid mold changeover—minimizing equipment downtime while ensuring machining accuracy and production stability—through deep synergy between mechanical structure, control system, and standardized processes. Its implementation can be analyzed from three dimensions: hardware design, software control, and process optimization.
At the hardware level, the core of the multi-tray system is the integration of modular trays and high-precision positioning devices. Each tray is equipped with a standardized interface, including positioning pin holes, locking mechanisms, and data interfaces, ensuring rapid docking with the machine tool table. The positioning device typically employs an end-tooth plate or steel ball positioning system. The end-tooth plate achieves radial and axial repeatability through inter-tooth meshing, with errors controllable to the micrometer level. The locking mechanism relies on hydraulic or pneumatic pistons, rigidly connecting the tray to the table via pull studs, maintaining stability even under cutting forces. Furthermore, the tray itself is made of high-strength cast iron or aerospace-grade aluminum alloy, with integrated precision positioning grooves on the bottom to further enhance structural rigidity.
At the software level, deep integration between the CNC system and the tray exchange device is crucial. The control system needs to receive signals from the machine tool and sensors in real time, including status feedback such as "machining complete" and "pallet in place," and automatically trigger the exchange process according to a preset program. For example, after the spindle completes machining the current workpiece, the CNC system instructs the machine tool to move to a safe position, while simultaneously controlling the motor of the exchange device to drive the pallet to lift or rotate—a rotary exchange table achieves pallet exchange through 180° rotation, while a reciprocating table relies on a linearly moving exchange arm to pull out and push in the pallet. Throughout the process, the hydraulic/pneumatic system operates synchronously to ensure the precise timing of pallet locking and releasing, avoiding collisions or positioning deviations caused by action delays. In terms of process optimization, separating internal and external operations and parallelizing operations are the core strategies for shortening mold changeover time. External operations (such as clamping new workpieces and unloading old workpieces) can be completed in advance during machine tool machining. Operators can use calibration fixtures at the exchange station to fix the blank to the spare pallet without occupying machine tool running time. Internal operations (such as pallet exchange and program calls) are executed rapidly through automated devices: when the machine tool issues a mold change command, the exchange device completes the pallet switching within seconds, while the CNC system automatically loads the corresponding workpiece's machining program, avoiding manual input errors. If the new workpiece has a similar process to the previous workpiece, the system can even reuse some machining parameters, further reducing debugging time.
To meet the demands of multi-variety, small-batch production, a flexible multi-pallet system also needs dynamic scheduling capabilities. By integrating MES (Manufacturing Execution System) or IoT modules, the system can monitor the status of each pallet in real time (e.g., idle, processing, awaiting exchange) and dynamically adjust the exchange order based on order priority and process route. For example, when an urgent order is inserted, the system can prioritize exchanging the corresponding pallet while temporarily storing the processing tasks of other pallets in a buffer zone, ensuring that the production rhythm is not disrupted.
Regarding accuracy assurance, the system needs to perform a self-calibration process regularly. Pallet positioning accuracy is detected using a laser interferometer or ballbar, and errors caused by mechanical wear or thermal deformation are automatically compensated. In addition, the pallet surface must be coated with an anti-rust coating, and the positioning groove and locking mechanism must be equipped with dust covers to prevent positioning failure caused by chips or coolant corrosion.
From an application perspective, flexible multi-tray systems have been widely adopted in automotive parts, aerospace, and medical device industries. For example, in engine block machining, the system can manage multiple pallets simultaneously, each carrying different models of cylinder block blanks. Mixed-flow production is achieved through rapid mold changes, eliminating the need for separate production lines for each model, significantly reducing equipment investment and space requirements.
Through collaborative innovation in hardware modularization, intelligent control, and lean processes, the flexible multi-tray manufacturing system reduces mold changeover time from tens of minutes in the traditional model to minutes or even seconds, while maintaining micron-level machining accuracy, providing an efficient and flexible solution for multi-variety, small-batch production.
