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First, the basic concept and classification of bending machine

Step 1 Define

A bending machine is a device that produces plastic deformation in a mold by applying pressure to a sheet metal to form a predetermined Angle or shape.

2. Main types

Mechanical bending machine: pressure is provided by mechanical transmission (such as gears, crankshaft), simple structure but low precision, suitable for small machining.

- Hydraulic bending machine: driven by hydraulic system, high pressure, high stability, suitable for medium and thick plate processing.

Numerical control bending machine (CNC) : through the CNC system to control the bending Angle, pressure and rear stop material positioning, high precision, high efficiency, suitable for mass production of complex workpieces.

- Servo electro-hydraulic bending machine: Combining hydraulic and servo motor technology, energy saving and fast response speed.

Second, the core structure and function of the bending machine

1. Fuselage: The frame that supports the overall structure must have high rigidity to withstand bending forces.

2. Slide block: a pressure component that moves up and down to connect the upper die and apply pressure.

3. Workbench: a platform for fixing the lower die, usually equipped with an adjustable V-shaped slot.

4. Hydraulic system (hydraulic/electro-hydraulic model) : composed of oil pump, cylinder, valve group, etc., to control pressure and stroke.

5. Back Gauge: the key component of CNC bending machine, which is used for plate positioning and directly affects bending accuracy.

6. Numerical control system (CNC model) : input parameters (Angle, pressure, stroke) to control the bending process.

Third, basic knowledge of bending process

1. Bending principle

- Pressure is applied to the sheet through the die to cause plastic deformation of the material.

- Key parameters: bending Angle, bending radius, bending force (related to material thickness and strength).

2. Material characteristics

- Elastic modulus: the ability of the material to resist deformation (such as stainless steel, which needs over-bending compensation).

- Minimum bending radius: Avoid material cracking, depending on material thickness and type.

- Springback: The Angle bounce of the material after unloading needs to be compensated by bending or mold design.

3. Bending force calculation

- Formula: 'P = (1.42 × σb × L × t²)/V'

-σb: Material tensile strength (MPa)

-L: Bending length (mm)

-t: Material thickness (mm)

-V: lower die opening width (mm)

Four, mold selection and use

1. Mold type

- Upper die (Punch) : Common shapes include sharp knife die, curved knife die, gooseneck die.

- Lower Die (DIE) : The bending radius is determined by the width of the V-shaped groove, which should be selected according to the thickness of the material (usually the width of the V-port = the thickness of the material ×8).

- Special mold: used for rolling, flattening, multi-step molding and other processes.

2. Mold materials

- Tool steel (Cr12MoV), alloy steel, heat treatment to improve wear resistance.

3. Matching principle

- Ratio of plate thickness to V-groove width (usually 1:8) to avoid material deformation or mold damage.

5. Operation process and safety specifications

1. Procedure

- Equipment inspection (hydraulic oil, lubrication system) → Select mold → input parameters (Angle, pressure) → Position plate → bending test → adjustment compensation → mass production.

2. Safety precautions

- Wear protective gloves/glasses to avoid cutting the board burrs.

- Do not put hands in the mold area.

- Check the tightness of the hydraulic system regularly to prevent oil leakage.

Six, common problems and solutions

1. The rebound is too large

- Solution: Increase bending Angle compensation, use mold with correction function or CNC system.

2. Bending crack

- Reason: poor material ductility or bending radius is too small → Replace soft material or increase R Angle.

3. Size deviation

- Calibrate rear stop, check mold wear or NC system parameters.

Seven, equipment selection and market positioning suggestions

1. Target customer analysis

- Sheet metal processing plants, chassis cabinet manufacturers, auto parts companies, etc.

2. Equipment selection

- Small enterprises: hydraulic CNC bending machine is recommended (economical and practical).

- High-end market: servo electro-hydraulic bending machines or high-precision models with laser detection.

3. Technology trends

- Intelligent: Integrated AI Angle compensation, automatic mold change system.

- Energy saving: servo motor drive to reduce energy consumption.

Maintenance and maintenance

1. Routine maintenance

- Clean mold and table debris.

- Check hydraulic oil level and oil quality.

2. Regular maintenance

- Replace hydraulic oil filter every 500 hours.

- Lubricate moving parts such as guide rails and lead screws.