91ÖÆƬ³§

CNC Turret Punch Press Processing Techniques

The typical processing techniques for CNC turret punch presses primarily include blanking and forming.

I. Blanking Process

The blanking process, also known as material separation, refers to the separation of processed material along a closed or open contour through shearing under external force. Shearing can either produce finished parts directly or create blanks for subsequent processes like bending, drawing, or forming. Generally, shearing processes are categorized into four main modes:

1. Single Punching. Completes punching in a single operation, including straight-line distribution, arc distribution, circumferential distribution, and grid hole punching.

2. Continuous Punching in the Same Direction. This method employs rectangular dies with partial overlap to process elongated holes, trimming edges, etc. When using this pattern, die stacking during cutting causes load deviation from the die center (off-center loading), potentially inducing torsional deformation in the machine structure and, in severe cases, damaging the dies. Therefore, for large-diameter holes, thick plates, or high-load cutting, minimize die overlap to reduce off-center loading.

3. Multi-directional continuous punching. This method employs small dies to process large holes, enhancing machine flexibility and expanding die processing capabilities.

4. Nibbling. This common method employs small circular dies with fine step increments to progressively punch arcs or spline curves. Due to the use of small circular dies for fitting, contour accuracy and cross-section quality are typically low, and punching efficiency is reduced. For large-diameter holes or high-volume applications, specialized punching dies are recommended.

II. Forming Processes

Forming processes involve subjecting sheet metal to external forces that exceed the material's yield point, inducing plastic deformation to achieve specific shapes and dimensions. Key techniques include flanging, shallow drawing, edge bending, and bending. This section outlines the primary forming characteristics of typical components and their corresponding dies. Forming processes primarily encompass two modes:

1. Single-pass forming: A shallow drawing process completed in one operation according to the die shape. This mode requires the die geometry to precisely match the part features, identical to conventional press processing. It represents a fully ¡°rigid¡± manufacturing approach.

2. Continuous forming: A process exceeding the die dimensions, such as forming large-scale louvers, flanging, or rolling steps.

The sheet metal forming process is influenced by multiple factors including material mechanical properties, sheet thickness, forming temperature, and forming speed. It involves aspects such as elastic deformation, plastic deformation, work hardening, and material anisotropy, exhibiting high nonlinearity. The forming mechanism is extremely complex, making it difficult to analyze using traditional mechanical formulas in actual production. Within a computer-simulated environment, employing the finite element method to simulate the material forming process enables prediction and evaluation of phenomena such as elastic springback, cracks, and wrinkles during forming. This facilitates in-depth research into the forming mechanism.