Processo di lavorazione di piegatura CNC: Una guida passo passo per la lavorazione della lamiera di precisione

Nella produzione della lamiera, raggiungimento coerente, piegature precise sono fondamentali, tuttavia la piegatura manuale tradizionale spesso è soggetta a errori umani, angoli incoerenti, e produttività lenta. IL CNC bending machining process solves these pain points by combining computer-controlled precision with automated operation, rendendolo ideale per parti prodotte in serie (come le staffe automobilistiche) e componenti personalizzati (come i quadri elettrici). Whether you’re a production manager aiming to reduce scrap rates or a technician learning to optimize setup, this guide breaks down the CNC bending process, sfide comuni, and solutions to ensure high-quality results.

1. What Is the CNC Bending Machining Process? Core Definition & Vantaggi principali

Before diving into steps, let’s clarify what makes CNC bending different from traditional methods:

Key Definition

IL CNC bending machining process is a computer-controlled manufacturing technique that uses a press brake to bend sheet metal (per esempio., acciaio, alluminio) into predefined shapes. It relies on 3D CAD designs and CAM-generated programs to automate critical parameters—including bending sequence, angle, pressure, and tool positioning—eliminating manual guesswork.

Why Choose CNC Bending Over Manual Bending?

A side-by-side comparison highlights the efficiency and precision benefits:

2. Step-by-Step Breakdown of the CNC Bending Machining Process

The CNC bending process follows a linear, repeatable workflow—from design to inspection. Each step builds on the previous one to ensure accuracy:

Fare un passo 1: Progetto & Programming

This foundational step sets the stage for error-free bending:

1. CAD Design: Use software (per esempio., SolidWorks, AutoCAD) to create 2D/3D drawings of the bent part. Critical details include:

• Final bend angles (per esempio., 90°, 45°)
• Material thickness (per esempio., 2mm aluminum)
• Bend radius (to avoid material cracking)

2. CAM Programming: Import the CAD file into CAM software (per esempio., Mastercam, SolidWorks CAM) to generate the press brake program. The software calculates:

• Bending sequence (order of bends to avoid tool collisions—e.g., bend the innermost angles first)
• Press force (per esempio., 50 kN for 2mm steel)
• Tool selection (matching upper/lower dies to the part’s shape)

Pro Tip: Always add a “flat pattern” to the CAD file—this shows the unbent sheet metal size, which is critical for cutting.

Fare un passo 2: Material Preparation

Using the wrong material or size leads to failed bends. Follow these steps:

1. Selezione dei materiali: Choose metal based on part requirements:

• Steel plates (per esempio., Q235): For high-strength parts (per esempio., machine frames)
• Aluminum plates (per esempio., 6061): For lightweight parts (per esempio., assetto automobilistico)
• Stainless steel (per esempio., 304): For corrosion-resistant parts (per esempio., food industry equipment)

2. Cutting: Use CNC shearing or laser cutting to trim large material into “blanks” (sheets matching the flat pattern size). Per esempio:

• A 200mm × 150mm blank for a 100mm × 50mm × 50mm box part.

Fare un passo 3: Machine Setup & Mold Installation

Incorrect setup is the #1 cause of oversized or misshapen parts. Here’s how to avoid it:

1. Die Selection: Match upper (punch) and lower (die) dies to the part’s bend radius:

• Use a 3mm radius die for 2mm aluminum (prevents cracking)
• Use a V-shaped die (per esempio., 8mm V-width) for 90° bends

2. Die Installation: Mount dies on the press brake’s upper ram (punch) and lower table (die). Secure them with clamps to avoid movement during bending.
3. Machine Calibration: Adjust press brake parameters via the CNC control panel:

• Pressure: Set to 40 kN for 1.5mm steel (too much pressure crushes the material; too little leaves incomplete bends)
• Velocità: 5–10 mm/s (faster speeds risk vibration; slower speeds reduce efficiency)
• Backgauge position: Align the backgauge (a stop that positions the blank) to the first bend’s location (per esempio., 50mm from the die edge).

Fare un passo 4: CNC Bending Execution

This is the automated phase—but operator supervision is still key:

1. Part Positioning: Place the cut blank on the press brake table. The backgauge pushes the blank to the correct position (no manual measuring needed).
2. Program Start: Press “run” on the CNC panel. The press brake:

• Lowers the upper die (punch) to contact the blank
• Applies the preset pressure to bend the material
• Retracts the punch to release the bent part

3. In-Process Check: After the first 2–3 parts, measure angles with a protractor to confirm accuracy. If off by 0.5°, adjust the CNC program’s angle offset.

Fare un passo 5: Post-trattamento & Quality Inspection

Even a perfectly bent part needs finishing and verification:

1. Sbavatura: Use a file or sanding tool to remove sharp edges from bend points (prevents injury and improves part fit).
2. Quality Inspection: Check key dimensions against the CAD file:

• Bend angle (use a digital protractor for ±0.05° accuracy)
• Part size (per esempio., 100mm × 50mm for the box part)
• Surface quality (no cracks, dents, or material deformation)

Esempio: A manufacturer producing 1,000 aluminum electrical enclosures followed this process—scrap rate dropped from 12% (manual bending) A 3%, and production time was cut by 60%.

3. Common Challenges in CNC Bending & How to Solve Them

Even with automation, issues can arise. Here’s how to troubleshoot:

4. Yigu Technology’s Perspective on CNC Bending Machining Process

Alla tecnologia Yigu, we’ve supported 250+ sheet metal manufacturers in optimizing their CNC bending machining process. From our experience, 70% of inefficiencies come from outdated programming or poor setup. Our Yigu CNC Press Brakes feature auto-calibration (cuts setup time by 40%) and integrated CAM software (preloads 1000+ bend parameters for common materials). For small shops, our training program teaches operators to reduce scrap rates to <5%—a client making automotive brackets saw a 50% productivity boost after 1 week of training. We also offer custom die sets for complex parts (per esempio., curved bends), ensuring clients avoid tool-related delays.

Domande frequenti: Common Questions About CNC Bending Machining Process

1. Q: How do I calculate the right press force for CNC bending?

UN: Use the formula: Forza (kN) = Material Thickness (mm) × Material Width (mm) × Material Factor (per esempio., 2.5 for steel, 1.5 for aluminum). Per esempio, 2mm steel × 100mm width × 2.5 = 500 kN. Most CNC press brakes have built-in calculators to simplify this.

2. Q: Can CNC bending handle thin materials (per esempio., 0.5mm aluminum)?

UN: Yes—but use a low-pressure setting (20–30 kN) and a narrow V-die (4mm width) to avoid material warping. Also, add a “hold time” (1–2 seconds) in the program to let the material set before releasing.

3. Q: How often should I maintain a CNC press brake for bending?

UN: Daily: Clean die surfaces and check clamp tightness. Weekly: Lubricate backgauge rails and calibrate pressure. Monthly: Inspect die wear (replace if edges are chipped) and test emergency stops. Following this schedule extends machine life by 3–5 years.