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Hydraulic Brake Press Machine Use And Maintenance

A Hydraulic Brake Press Machine is a high-precision processing equipment used for cold bending and forming of metal sheets. It uses a CNC system to control the slide stroke and back gauge position, enabling multi-angle, multi-process bending of the sheet metal.

Below is a systematic user and maintenance guide for CNC hydraulic brake press machines, covering everything from pre-start checks, operating procedures, and parameter settings to daily maintenance, fault prevention, and lifespan management. It is suitable for production, process, and equipment management personnel.

1. Basic Equipment Understanding (Quickly Understand the Core System)

The hydraulic brake press machine mainly consists of the following systems:

1) Mechanical Structure System

Frame (integral welding + tempering treatment)
Upper slide (Ram)
Worktable (with compensation device)
Back gauge system (X/R/Z axes)

2) Hydraulic System

Oil tank, oil pump, proportional valve/servo valve
Hydraulic cylinder (left and right synchronous)
Hydraulic pipelines and seals

3) CNC System (Core)

Common Systems:

EL15T / EL19T
Delem (e.g., DA53T / DA66T)
Cybelec (e.g., Cybtouch series)

Functions:

Bending angle control
Stroke control (Y1/Y2 axis synchronous)
Back gauge positioning (X axis, etc.)
Process programming

2. Standard Operating Procedures (Detailed Version)

1) Pre-Start Inspection (Mandatory)

Electrical Inspection

Power supply voltage stable (within ±10%)
Emergency stop button reset
No abnormal alarms from control cabinet

Hydraulic System Inspection

Oil level: Above 2/3 of the gauge
Oil temperature: Recommended 15℃~55℃
Check for leaks

Mold Inspection

Upper/lower mold securely installed
Mold free of cracks and chipped corners
V-groove selection correct (generally V=8~12×plate thickness)

Backgauge Inspection

Guide rails well lubricated
No foreign objects obstructing the flow

2) Start-up Procedure

Turn on main power
Start CNC system
Start oil pump motor
Return equipment to reference point (zero)
Check if each axis is running normally

Note: Formal machining is strictly prohibited if the axis has not returned to zero.

3) Programming and Parameter Setting Of Hydraulic Brake Press Machine

Common Parameters:

Bending Angle Control

Set target angle (e.g., 90°)
System automatically calculates Y-axis depth

Back gauge (X-axis)

Controls bending dimension accuracy
Accuracy up to ±1mm

Slider speed parameters

Fast down
Bending speed
Return speed

Holding time

Affects angle stability (0.5~2 seconds)

4) Trial bending and first piece confirmation (critical step)

Flow:

Idle stroke check
Single bending test
Measure with angle gauge
Fine-tuning parameters (angle compensation)

Common adjustments:

Angle too large → Reduce indentation depth

Angle too small → Increase indentation depth

5) Formal bending operation

Key points of operation:

Sheet positioning

Closely against back gauge

Prevent skewing

Bending sequence

Inside first, then outside

Avoid interference

Multiple bends

Pay attention to flange space

Prevent collision with mold

Safe operation

Keep hands away from danger zone

Use foot switch for control

3. Key Process Controls (Core Factors Affecting Accuracy)

1) Bending Compensation (Very Important)

Mechanical Compensation / Hydraulic Compensation

Function:

Counteracts worktable deflection
Ensuring consistent angles along the entire bending line

Recommendation:

Compensation must be enabled for thick plates
Correction must be applied to long workpieces

2) Die Selection Principles

Plate thickness	Recommended V-groove
1mm	8mm
2mm	16mm
3mm	24mm
6mm	48mm

Principle:

V-groove = 8~12 × Plate thickness

3) Springback Control

Influencing Factors:

Material (Stainless Steel > Carbon Steel)
Plate Thickness
Bending Angle

Solutions:

Increase the pressing amount
Use CNC angle compensation

4. Routine Maintenance (by Cycle)

1) Daily Maintenance

Clean the hydraulic brake press machine tool (metal filings, oil stains)
Check oil level
Check air/oil temperature
Check mold condition
Simple lubrication of guide rails

2) Weekly Maintenance

Clean the electrical control cabinet (dustproof)
Check hydraulic lines
Check back gauge accuracy
Tighten bolts

3) Monthly Maintenance

Replace or clean the filter
Check hydraulic oil contamination
Correct the back gauge
Check synchronization accuracy (Y1/Y2)

4) Semi-annual/Annual Maintenance

Replace hydraulic oil (recommended 3000~5000 hours)
Check cylinder seals
Calibrate overall machine accuracy
Check electrical system aging

5. Key Points for Hydraulic System Maintenance (Core)

1) Hydraulic Oil Management

Control Indicators:

Cleanliness: NAS level 8 or below
Temperature: 30~50℃ (optimal)

2) Common Problems

– Overheating

Causes:

Continuous high-load operation
Poor heat dissipation

Solutions:

Add a cooler
Stop the CNC press brake machine to cool it down

– Unstable Pressure

Causes:

Proportional valve malfunction
Oil contamination

– Synchronization Error (Y1/Y2)

Causes:

Graphite ruler contamination
Cylinder asynchrony

6. Hydraulic Brake Press Machine Bending Die Maintenance And Management

Die is one of the direct determinants of bending quality.

1) Pre-use Inspection

Check for chipped cutting edges
Check for indentations on the working surface
Check for flatness of the mounting surface
Check for misalignment at the joints of segmented dies
Check for correct die numbering

2) Precautions During Use

Do not overload the die
Do not use an incorrect die to press a large plate thickness
Do not subject the die to impact loading
Prevent foreign objects from getting stuck in the die contact surface

3) Post-use Maintenance

Clean oil and iron filings promptly
Apply rust-preventive oil
Store dies by category
Manage dies of different sizes separately
Register easily worn dies separately

4) Impact of Die Wear

Common manifestations of die wear:

Unstable bending angle
Heavier surface indentations
Larger springback
Poor dimensional repeatability

When the die is in poor condition, simply adjusting parameters is unlikely to solve the problem.

7. Key Maintenance Points for the Backgauge System

The backgauge determines dimensional accuracy, especially crucial for batch production.

1) Common Problems

Inaccurate repositioning
Left and right asynchrony
Movement jamming
Large backlash
Dimensional drift

2) Key Maintenance Points

Clean guide rails and lead screw
Check timing belt or coupling
Check servo motor status
Check backlash
Check mechanical limit switches
Keep backgauge fingers clean and free from damage

3) Practical Usage Recommendations

Use multiple supports for long materials
Prevent top misalignment for soft materials and thin plates
Perform first-piece verification after each shift change or material change

8. CNC System and Electrical System Maintenance

1) CNC System

Regularly perform the following:

Program backup
Parameter backup
Process database organization
User access control
Alarm log review

Recommended to retain:

Common plate thickness parameters
Common material parameters
Common mold parameters
Common fault handling records

This will greatly improve efficiency during on-site personnel changes, material changes, and shift changes.

2) Electrical Cabinet Maintenance

Electrical cabinet should be protected against:

Dust
Oil mist
High temperature
Loose wiring
Terminal oxidation

Measures include:

Regularly cleaning fans and filters
Checking heat dissipation
Checking terminal tightness
Checking servo driver alarms
Checking contactor contact overheating

3) Sensors and Limit Switches

Photoelectric, magnetic, and proximity switches should be kept clean and reliably fixed.
If zeroing failure, positioning abnormalities, or operation interruptions occur, first check these components.

9. Key Points for Handling Common Materials

1) Low Carbon Steel

Most common, relatively stable in bending.
Suitable for establishing basic parameter templates.

2) Stainless Steel

Characteristics: High springback, high tonnage requirements, high surface finish requirements.

Suggestions:

Appropriately enlarge the V-shaped opening.
Keep the die surface clean.
Avoid cutting edge damage.
Increase the number of trial bends.

3) Aluminum Plate

Characteristics: Soft, easily damaged, sensitive surface.

Suggestions:

Smooth die surface.
Pay attention to protective film.
Avoid excessively small V-shaped opening.
Control indentation and tearing.

4) Galvanized Steel

Prone to surface scratches and coating damage.
Pay special attention to die cleaning and positioning/sliding.

5) High-Strength Steel

High bending difficulty, high springback, high tonnage requirements.
It is essential to verify the equipment tonnage, die strength, and safety margin.

10. Practical Methods for Bending Accuracy Control

1) Angle Control

Angle errors generally originate from:

Inaccurate springback estimation
Die wear
Material batch variations
Oil temperature variations
Insufficient equipment rigidity
Inappropriate deflection compensation

Solutions:

Trial bending first
Establish a material database
Stabilize oil temperature
Regularly calibrate and compensate the die

2) Dimension Control

Dimensional errors generally originate from:

Back gauge deviation
Unstable sheet metal positioning
Sheet metal warping
Inconsistent manual feeding
Incorrect program settings

Solutions:

Verify the back gauge
Use positioning blocks
Standardize operating procedures
First piece confirmation

3) Angle Consistency for Long Workpieces

Common causes of differences between the middle and end angles of long workpieces:

Insufficient compensation
Frame deformation under stress
Uneven die installation
Sheet metal length too long
Insufficient workpiece support

11. Key Strategies for Extending Equipment Life

Correct Operation > Any Maintenance:

Avoid Overloading and Bending
Avoid Uneven Loading

Mold Protection:

Avoid Mold Collision
Avoid Misalignment

Hydraulic System Cleaning:

Contamination is the Biggest Killer

Regular Calibration:

Maintain Stable Precision

12. Quick Reference Table for Common Faults (Practical)

Faults	Possible causes	Solutions
Inconsistent angles	Insufficient compensation	Adjust compensation
Inaccurate dimensions	Material obstruction error	Calibrate X-axis
Abnormal noise	Insufficient lubrication	Add oil
Oil leak	Seal aging	Replace seal
System alarm	Parameter error	Reset program

13. Maintenance During Long-Term Shutdowns

If the equipment will be shut down for an extended period, the following is recommended:

Thoroughly clean the equipment.
Remove the molds and apply anti-rust oil.
Apply anti-rust treatment to the surfaces of guide rails, lead screws, and sliders.
Maintain the hydraulic system at the specified oil level.
Disconnect the main power supply.
Cover critical parts with dustproof covers. Perform regular no-load checks.
Prevent the electrical cabinet from getting damp.

If the ambient humidity is high, pay special attention to rust prevention for the electrical cabinet and molds.

14. Easily Overlooked but Crucial Details

1) Machine Level

An uneven machine directly affects left-right synchronization, force distribution, and bending angle.
Many people only adjust parameters without checking the level; the problem actually lies in the fundamentals.

2) Ambient Temperature

Significant temperature differences cause changes in hydraulic oil viscosity, leading to inconsistent bending angles between morning and evening.
Especially during initial startup in winter and prolonged operation in summer, parameters cannot be directly copied.

3) First Article Inspection

A first article inspection is essential for any new batch, new material, new mold, or new operator.

4) Operator Habits

Inconsistent material feeding posture
Over-reliance on experience and failure to record parameters
Lack of cleaning and maintenance
Failure to report abnormalities

These are all important reasons why equipment accuracy gradually deteriorates.

15. Conclusion

The essence of a CNC hydraulic brake press machine:

= A comprehensive result of “hydraulic stability + CNC precision + die matching + standardized operation”

For a CNC hydraulic press brake bending machine to maintain long-term stability, four key things are crucial: standardized operation, correct die selection, a healthy hydraulic system, and proper regular maintenance.