A turret punch press or turret press is a type of punching press used for stamping metal forming.

Stamping and stamping work in general is a process well suited for mass production. However, initial tooling costs for both the machine and job-specific stamping tools are high. This limits stamping work to small volumes and prototype work. Turret punches are one way to get around this cost. Tooling for turret punches uses a large number of standard punch tools: different-sized holes, straight edges, common notches or mounting holes. By using a large number of strokes, and using several different tools in sequence, a turret press can make a wide variety of parts without first building a dedicated stamping tool for the task. This saves both time and money, allowing rapid prototyping or low-volume production without tooling delays.

A typical CNC turret punch press can have a selection of up to 60 tools in a “turret” that can be rotated to bring any tool to the punching position. A simple shape such as a square, circle, or hexagon is cut directly from the sheet. A complex shape can be cut by making many square or circular cuts all around. Since stamping tools require a matching punch and die set, there are two corresponding turrets above and below the bed for punches and dies. The two turrets had to rotate in precise synchronization and be carefully maintained in alignment. Multiple punches of the same shape can be used in a turret, each rotated by a different angle since there is usually no function to rotate the sheet metal workpiece relative to the tool

Punches are less flexible than lasers when cutting complex shapes, but are faster when cutting repetitive shapes, such as the grille of an air-conditioning unit. Some installations combine laser and stamping functions in one machine

 

Most turret punches are CNC controlled to automatically position the metal plate under the tool and program a specific tool selection. The CAM process begins by converting the CAD design of the finished product into the number of individual stamping operations required, depending on the tools available in the turntable.

The precise loading of the tool may vary according to the needs of a particular job. The CAD stage is also optimized for turret stamping: operations such as fillets are done faster with one chamfer cut than a full fillet cut that requires several strokes. Changing a non-trivial dimension (such as the width of the ventilation slot) might match available tooling, requiring one cut instead of cutting each side individually. CAD support also manages the selection of tools to be loaded into the turntable before commencing work

Because each tool in a turret press is relatively small, the press requires very little power compared to a press that makes a similar part with a single punch stroke. This makes the tool lighter and sometimes less expensive, although this is offset by the complexity of the turntable and sheet positioning. Turret punches operate faster per stroke than heavier tool presses, and of course, require many strokes. The turret punch can reach 600 strokes per minute.

The latest state-of-the-art machines can also be added with equipment for forming and bending as well as stamping and cutting. [1] While unlikely to replace press brakes for box making, the ability to form even small lugs could turn a two-machine process into a one-machine process, reducing material handling time.

Reference： https://en.wikipedia.org/wiki/Turret_punch