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We provide both NC and CNC hdyraulic press brake.
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  • 3-years warranty time
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The complete guide to the press brake machine is just updated in 2019. And we will continue to get this post updated for more new content.

What Is A Press Brake

First please spend several minutes to learn what is a press brake.

In the following content, we will much focus on the hydraulic press brake, not the manual type or the mechanical type.

See also:

Why the Machine for Sheet Metal Bending is Been Called Press Brake?

Working Principle of the Hydraulic Press Brake

Fix the top punch and bottom die on the upper and lower worktable, utilize the relative motion of the worktable driven by hydraulic transmission as well as the shape of the punch and die, to achieve the bending formation for sheet metal materials.

bending process

Hydraulic Press Brake Working Principle Diagram

Hydraulic Press Brake Working Principle Diagram

Hydraulic Press Brake Composition

Press Brake Structure Drawing

Generally, the press brake machine including four main parts:

  • Mechanical parts
  • Electrical parts
  • Hydraulic part
  • NC/CNC controller

See also:

Press Brake Application

Press brakes are widely used in energy, transportation, automobile, machinery, metallurgy, shipbuilding, aviation, military, agricultural machinery, petroleum machinery, power generation industries.

Press Brake Application

 

Press Brake Toolings

Press Brake Toolings Drawing_MachineMfg

Press brake standard toolings including the punch and die, for the stamping and separation of sheet metal. The die for forming has a cavity, while for separation it has a blade edge.

See also:

Press Brake Gauge

The commonly used press brake gauge including angle gauge, angle ruler and venier.

Press Brake Gauge

 

TOP Press Brake Manufacturer List

The following two lists will definitely help you sort out the ideal press brake manufacturers for you.

 

Press Brake Training

The best training provides you with the manuals, you can learn wherever you are, and anytime you want. Here I collect some of the most popular manuals for your reference:

You can also check out the definitive guide to press brake bending basics to learn more information about sheet metal bending.

Press Brake Safety

I believe here I don’t need to explain how it is important to take note of the safety operation of press brake. You can check out the press brake safety tips to know more.

If you press brake operators, you should read below press brake common failure analysis carefully, probably it will help you solve big problems.

 

Press Brake Maintenance Checklist

Before the press brake maintenance or cleaning of the machine, align the top punch with the bottom die before drop it, then shut down the press brake until the completion of the work. If required to start the machine or other operations, select the jog mode, and ensure safety.

The maintenance content is as follows:

Hydraulic oil circuit

  • Weekly inspection of the oil levels in oil tanks, it should also be checked for hydraulic system maintenance. If oil level below the oil window, the oil tank should be filled with hydraulic oil;
  • The hydraulic oil used in press brake is ISO HM46 or Mobil DTE25;
  • The new press brake should change the oil after 2000 hours running, after that change oil for every 4,000-6,000 hours operation. Clean the fuel tank for every oil changing;
  • System oil temperature should be between 35℃~60℃, no more than 70 ℃, the too high temperature will lead to deterioration of oily and accessory damage.

Filter

  • Each time during the oil change, the filter should be replaced or thoroughly cleaned;
  • If the press brake has the related alarm or the oil is not clean, or some other unusual things for the filter, the filter should be replaced;
  • Clean the air filter on the tank every 3 months, preferably change it every year.

Hydraulic Parts

  • Monthly cleaning of hydraulic components (substrates, valves, motors, pumps, tubing, etc.), to prevent dirt from entering the system, cannot use detergent;
  • One month after the use of the new press brake machine, check whether the bending point of the tubing has deformation, if yes then it should be replaced. After the use of two months, should be fastened to all parts of the connection, the press brake should be shut down to ensure that there was no pressure of the system when doing this work.

 

Press Brake Inspection Checklist

Brief Description

  • Standard test order does not mean the actual test order, it is changeable
  • Adjusting the mechanism and parts which may affect the precision is prohibited during the test process.
  • Workpiece precision inspection conditions:
  • Requirements on workpiece
  • If the workpiece is made by an A3 steel plate, it’s tensile strength Qb≤ 450MPa
  • The number of workpieces shall not less than 3 pieces
  • The opening size of lower die shall be 8-10 times as large as workpiece thickness
  • Workpiece should be put on the worktable middle position
  • Bending angle is 90°
  • Measure from end 100mm

The inspection method and accuracy range shall be based on GBT-14349-2011-Metal Press Brake- Precision

Press Brake Inspection Checklist Form

Note: the worktable is floated, inspection G2, G3 shall refer worktable vertical plate as a benchmark.

Press Brake Inspection Checklist Form

 

Press Brake Bending Radius

There should have a bending radius for sheet metal bending, it should not be too large or too small, and should be chosen appropriately. If the bending radius is too small, it will cause cracking at the bend position; if the bending radius is too large, it is easy to rebound.

The optimum bending radius of different thickness of various materials (bend inner RADIUS) see table below:

Metal Annealing Condition Cold Hardening State
The corresponding position of bending direction and fiber direction
Vertical Parallel Vertical Parallel
08, 10 0.1t 0.4t 0.4t 0.8t
15, 20 0.1t 0.5t 0.5t 1.0t
25, 30 0.2t 0.6t 0.6t 1.2t
45, 50 0.5t 1.0t 1.0t 1.7t
65Mn 1.0t 2.0t 2.0t 3.0t
Aluminum 0.1t 0.35t 0.5t 1.0t
Brass 0.1t 0.35t 1.0t 2.0t
Soft Brass 0.1t 0.35t 0.35t 0.8t
Semi-rigid Brass 0.1t 0.35t 0.5t 1.2t
Phosphor bronze / / 1.0t 3.0t

The data in the table above is the preferred data for reference only. In fact, the rounded corners of press brake are usually 0.3, and a small number of the rounded corners of the press brake punch is 0.5.

For ordinary low carbon steel plate, anti-rust aluminum plate, yellow copper, purple copper etc., the inner radius 0.2 is no problem, but for some high carbon steel, hard aluminum, super-hard aluminum, the use of 0.2 radius will lead to bending fracture or the outer radius crack.

 

Press Brake Tonnage Calculation

Press Brake Tonnage Calculation Formula

Click above link you will get the answers.

 

DIY Press Brake

Sometimes, the workshop owners need to bend steel, just for several pieces of steel, so buy a completely new press brake is not the best way. That’s why they want to build a press brake on their own, just to diy some simple press brake for bending purpose.

Therefore, the homemade metal brake press is what they want.

Here I collect some videos for the home build press brake, hope you can make one with the tutorials been provided.

Press Brake Wiring Diagram

Different manufacturers will design different press brake wiring diagram. When you purchase it, the suppliers will send you the wiring diagram together with the hydraulic diagram as well as the installation and operation manuals. If you did not see it when you receive the machine, please contact your supplier immediately.

The following press brake wiring diagram is from us, just for your reference.

Press Brake Wiring Diagram

 

Press Brake Controller

There are two popular press brake controllers, one is from China’s Estun, which is the sole agent of DELEM control in China, the other one is DELEM from Holland.

Press Brake Controller

See also:

The key factor for press brake including two parts, one is the machine itself, such as the quality, accuracy, etc, the other one is the control system.

The installation manual and operation manual of press brake controllers in PDF form can be downloaded from below link.

Operation Manual:

Installation Manual:

 

Press Brake Programming and Setup

Press Brake Programing

The above operation manual and installation manual of press brake controllers have explained the programming and setup very clear, please download it from above and read it carefully.

 

Press Brake User Manual

Electro-hydraulic servo press brake operation manual fea

How to use the press brake

According to fabricate Q235 mild steel with hydraulic press brake to do a simple introduction:

  • First, connect the power, turn on the key switch on the control panel, and then press the pump to start, then you can hear the oil pump rotating sound. (The machine does not run at the current time)
  • Stroke adjustment. You must pay attention to stroke adjustment for press brake operation, it must be tested before bending. Must ensure that there is clearance which equals the thickness of the plate when the top punch down to the bottom of the lower die. Otherwise, the mold and press brake will be damaged. The adjustment of the stroke also has the electric quick adjustment and the manual fine adjusts.
  • Regarding V-width choosing, generally, the width of the V opening should be 8 times the thickness of the plate. For example, for bending 4mm plate, you should choose 32mm V-opening die.
  • Back gauge adjustment generally has electric fast adjustment and manual fine-adjustment.
  • Step down the pedal switch to start bending, you can loosen at any time. If loosen the foot, the bending machine will stop, step again to continue bending.

Here we provide press brake operation manuals to guide you operating press brake. Download the press brake operating instructions here.

See also:

 

Press Brake Forming Process Technology

 

Press Brake Tips

If you read the articles on our bending category, you will see various different types of articles writing about press brake and sheet metal bending. So take your time to read it carefully for learning. You will benefit a lot from it.

A quick calculation method of sheet metal bend expansion

For sheet metal bending and expansion, one side of the sheet will be elongated, the other side will be compressed. The affecting factors including material type, material thickness, heat treatment and bending angle.

calculation method of sheet metal bend expansion

 

Expand Calculation Principle:

  • During the bending process, the outer layer is subjected to tensile stress, and the inner layers are subjected to compressive stress. There is a transition layer which is neither tensile nor pressure from pull to pressure, which is called the neutral layer. The length of the neutral layer remains unchanged in the bending process, the same as the length before the bending, so the neutral layer is the basis for calculating the expansion length of the bending piece.
  • The position of the neutral layer is related to the degree of deformation.

When the bending radius is larger and the bending angle is small, the deformation degree is small, and the neutral layer is near the center of the sheet thickness; When the bending radius becomes smaller and the bending angle increases, the degree of deformation increases, and the position of the neutral layer moves toward the inner part of the bending center gradually. The distance from the neutral layer to the inside of the sheet is expressed in λ.

 

Basic Formula for Expansion Calculation:

Expansion length = inner layer + inner layer + compensation amount

Formula for Expansion Calculation

Calculation of minimum bending edge of one bend

The starting state of the L-bend is shown in the following illustration:

Reference table for bending inner R and minimum bending height of the cold rolled sheet

No. Thickness Die Groove Width Convex die R Min Bending Height
1 0.5 4 0.2 3
2 0.6 4 0.2 3.2
3 0.8 5 0.8/0.2 3.7
4 1.0 6 1/0.2 4.4
5 1.2 8/6 1/0.2 5.5/4.5
6 1.5 10/8 1/0.2 6.8/5.8
7 2.0 12 1.5/0.5 8.3
8 2.5 16/14 1.5/0.5 10.7/9.7
9 3.0 18 2/0.5 12.1
10 3.5 20 2 13.5
11 4.0 25 3 16.5

The starting state of the Z-bend is shown in the following illustration:

Z-bend

The minimum bending size (L) of the sheet metal corresponding to Z-bend for materials with different thickness is shown in the following table:

No. Thickness Die Groove Width Convex die R Z Bending Height
1 0.5 4 0.2 8.5
2 0.6 4 0.2 8.8
3 0.8 5 0.8/0.2 9.5
4 1.0 6 1/0.2 10.4
5 1.2 8/6 1/0.2 11.7/10.7
6 1.5 10/8 1/0.2 13.3/12.3
7 2.0 12 1.5/0.5 14.3
8 2.5 16/14 1.5/0.5 18.2/17.2
9 3.0 18 2/0.5 20.1
10 3.5 20 2 22
11 4.0 25 3 25.5

See also:

Press Brake Bending Allowance (Tolerances)

1) Tolerance Standards for Common Bending

Tolerance Standards for Common Bending

2) Tolerance Standards for Z Bending

Tolerance Standards for Z Bending

3) Tolerance Standards for V Bending

Tolerance Standards for V Bending

4) Tolerance Standards for U Bending

Tolerance Standards for U Bending

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