Press brake tooling is a tool used by a press brake to form and process sheet materials. The press brake tools are divided into upper tools and lower tools of the press brake. The upper tools of the press brake (punch) are installed on the slider through a fixture. On the top, the lower tools of the bending machine are fixed on the machine table. It mainly realizes the processing of the shape of the article by changing the physical state of the formed material.
Overview of Toolings
- Press brake tooling is a tool used by a press brake to form and process sheet materials. The press brake tools are divided into upper tools and lower tools of the press brake. The upper tools of the press brake (punch) are installed on the slider through a fixture. On the top, the lower tools of the bending machine are fixed on the machine table. It mainly realizes the processing of the shape of the article by changing the physical state of the formed material.
- The bending tools are made of steel with special heat treatment, which has the characteristics of high hardness, not easy to wear, and high pressure. However, each set of tools has its ultimate pressure: ton/m, so when using the tools Select the length of the tools, that is, how much pressure should be added per meter, and must not exceed the pressure marked on the tools.
- Material suitable for bending machine tools: high carbon structural steel, low carbon alloy steel, 42CrMo steel, Cr12MoV steel.
- HARSLE uses 42CrMo steel, which is low-carbon alloy steel with good performance. After heat treatment, the hardness can reach HRC48±2 degrees, which can be well adapted to various high-precision and strict-standard bending machines with strong wear resistance For tools production, 42CrMo is widely used at home and abroad, and the application range is also very wide. The main features are high strength, high toughness, and good wear resistance.
- Bending machine tools heat treatment
- Classification of quenching: overall, local quenching and surface quenching; according to whether the phase transformation is complete during heating, there are complete quenching and incomplete quenching (for hypereutectoid steel, this method is also called subcritical quenching); according to the content of phase transformation during cooling, there are graded quenching, isothermal quenching, and underspend quenching, etc.
- Surface quenching is a local quenching method in which the surface layer of the steel part is quenched to a certain depth, while the core part remains unquenched. The overall quenching is to maintain the quenched state from the surface layer to the core.
- Quenching and hardening temperature: fifty-two to sixty degrees Celsius.
- Generally, ordinary bending machine tools are locally quenched by high-frequency local heat treatment. The CNC bending machine tools adopt the whole body quenching heat treatment method. Therefore, CNC bending machine tools are much more durable than ordinary tools.
- HARSLE bending machine tools are all quenched as a whole.
The advantages of integral quenching:
- Improve the physical properties of the surface such as hardness, wear resistance, corrosion resistance, oxidation resistance, etc., and increase the life;
- Improve the scratch resistance of the surface and increase the productivity;
- Reduced cost and simplified production process;
- It can be used for the repair of the tools surface of the bending machine;
- Reduce energy consumption and environmental pollution.
- Selection of bending machine tools
- HARSLE will provide a set of standard tools, a 90-degree standard upper tool, and a standard lower die.
- For the lower dies of the torsion axis bending machine, the standard HARSLE is multi-V lower dies, and the standard configuration of the CNC bending machine HARSLE is the 1V, 2V, 4V lower die.
- The normal height of double V is 110mm, and the normal height of 4V is 60mm. There are 2 heights of single V, 80mm and 120mm, and 80mm is usually selected.
- The lower die with double V has 2 V-slots to choose from, and the split lower die with a concave notch must be used with guide rails.
- Selection of Punch
From the perspective of final molding, if it is to form an acute angle, the upper mold generally uses a sharp knife mold. If it is to form a right angle or an obtuse angle, the upper die generally uses a straight knife die, also known as an asymmetrical die.
For forming some workpieces that need to be avoided, generally, the upper mold is a machete mold, and the lower mold is mainly selected according to the final molding appearance.
Some other special upper molds, such as flattening knife molds, arc knives, etc. In the actual selection, some with special molding requirements can be specially customized.
- Selection of lower die notch
- Bending machine tools segmentation
- Standard length: 835mm, 800mm, 500mm (standard NC bending machine mold product specifications, non-standard bending machine mold specifications can be customized for processing and production according to the drawings provided by customers).
- The tool segment specifications are as follows:
835mm：100*2 (left and right)、300*1、200*1、50*1、40*1、20*1、15*1、10*1
808mm：100(left and right)、10*1、15*1、20*1、40*1、50*1、200*1、270*1
- Generally, the upper punch is segmented. If the customer has special requirements, the lower die can also be segmented. However, it is necessary to use mold support to fix the tool (this is limited to the application of multi-V molds or wide worktables, but no mold support is required for concentric tools or narrow worktables).
Classification And Application of Bending Machine Tools
- Bending tools can be divided into two categories, one is the upper tool(punch) and its accessories, and the other is the lower tool (die) and its accessories. The assembly of the tools includes a tool fixture, a set of tools, a tool handle, a tool head, and the like. The lower die includes a lower die, lower die holder, die base, tool clamp, and so on. They can be combined.
- Punch classification
Ordinary standard punch: used for bending 90°-180° angle.
Advantages: Thick and thin plates are universal, durable, and the most widely used.
Acute punch: used for bending 20°-180° angle.
Advantages: It can be bent to smaller angles and sizes, and the R arc after folding is small, beautiful, and angular.
Gooseneck punch: also called a machete, used for bending 30°-180°.
Advantages: It is used for U-shaped products that cannot be completed by standard punch and acute punch, and is widely applicable. It is generally used for folded grooves or products with greater depth requirements for the center of the punch.
Sash punch: A single-bend forming tool designed for complex products.
This type of die has a very narrow elbow and is usually used to process facades or door frames.
Swing ear sections: This type of tool generally processes box-shaped products, and the left and right ears can quickly return to their original positions after the bending is completed.
Narrow punch: It is a thin straight upper die, which is used to penetrate deep into the sheet, which cannot be reached by ordinary dies. It is an efficient forming die for closing square sheets. According to the specification and design of the profile, the die is the last closing stage for bending the square profile.
The punch has several flaws.
- The first is that excessive bending will cause the workpiece to bend.
- The second is that the parts will stick to the tool.
- Because of its length-to-thickness ratio, this die is seldom suitable for large tonnage press brakes compared to the standard punch.
- Die classification
Single V die: The notch angle is generally between 30 degrees and 90 degrees. Compared with the multi-V lower die, the workpiece has more free space during the bending process.
Double V die: The notch angle is generally between 30 degrees and 90 degrees. Compared with the multi-V lower die, the workpiece has more free space during the bending process.
Multi-V die: The appropriate V-shaped opening width can be determined according to the bending thickness, and it can also be used with a semi-circular notch.
No indentation die: Compared with ordinary die, such dies can avoid indentations caused by the workpiece coming into contact with the notch during the bending process.
- Special-shaped tools
Hemming punches and die: It is used to shoot dead edges, and it is used in conjunction with a pointed die. First, bend the workpiece to an angle less than 45° with a pointed die, and then press it into a dead edge with a flattening die. It is mainly used for frame reinforcement.
Radius punch and die: It is more suitable for large-scale steel structure parts, iron towers, street light poles, high light poles, automobile beams, automobile cargo boxes, and other related industries.
Offset punch and die: Also known as Z-shaped die, it is mainly used for one-time bending of small-sized Z-shaped workpieces. It is divided into two types: fixed and adjustable.
Curl punch and die: Mainly used for thick materials and hinges.
Rib punch and die: mainly used to increase rigidity while the tool helps reduce and avoid collisions.
Channel punch and die: used for one-shot U-shape tooling, saving time when processing bent parts
- Related accessories
Anti-Scratch Film: In addition to the indentation-free bending surface, it also improves tool life. Bending protective film is a buffer between the workpiece and the corner of the lower die, to prevent the workpiece from indentation during bending. When using, just put the bending film on the lower die.
Digital angle cube: A digital angle gauge, sometimes called a digital protractor, can be used in place of a protractor to measure angles. They use a digital function to measure the angle, so they are particularly accurate and can quickly determine the angle.
A magnetic squaring arm: It is a flexible tool that allows you to bend parts with greater precision. Increase production and improve efficiency.
Universal protractor: It is a high-precision protractor used for precise angle measurement of machine tools, molds, and fixtures. The angle is displayed on a dial with a built-in magnifying glass.
Tool cabinet: It is an airtight container for storing, arranging, and handling tools. They are also used to protect molds from external weather elements.
Ordinary clamps: generally used for the standard configuration of NC bending machine.
Ordinary quick clamps: generally used for the standard configuration of torsion axis CNC bending machine and electro-hydraulic bending machine.
One-key release quick clamps: generally used for Genius series press brakes as standard.
KYOKKO type double-side fast tool clamps
Common Bending Machine Tools Problems
If the user uses a new CNC press brake, all aspects of the standard CNC hydraulic press brake are very good. When bending the sheet metal part on the press brake with the new die, the part also meets the drawing requirements. But after a period of production, it will be found that the workpiece bent by the mold does not meet the requirements of the drawing. Why?
Cause analysis: wear of punch
- . The punch is generally an omnipotent tool, and the general bending punch can meet the bending requirements of most sheet metal parts. In addition, punches are also frequently used. In other words, we have a punch for metal stamping machines.
- The R angle of the upper bending die is small, generally less than R0.5mm. When bending, the pressure is concentrated on the R corner of the upper die. The stress at the R corner is large. Therefore, the upper bending die is easily worn.
Therefore, the wear of the punch causes the R angle to increase. In the calculation of the workpiece series data, the size of the bending R angle is one of the factors affecting the expansion coefficient of the workpiece. Therefore, users often complain that the size of the workpieces produced by the CNC bending machine increases after long-term use. In this case, in fact, the problem is not the responsibility of the manufacturer, it is caused by the customer’s natural wear and tear or improper use.
Card tool is a frequent mold problem. During the bending process, once the mold clamping of the bending machine is inflexible or even stuck, the production must be stopped immediately to find out the cause of the stuck mold and eliminate the fault. Otherwise, the failure will be expanded, resulting in damage to the bending machine mold.
The main reasons for the tool are poor guide and tilt of the tool. Or there are foreign objects between the templates so that the templates cannot be flatly attached; the strength design of the mold is not enough or the force is uneven. Cause the deformation of the mold, such as the hardness and thickness of the mold base and the template are too small and are easily deformed by external force; the position of the mold is not installed correctly, and the positioning error of the upper and lower molds is out of tolerance. Or the precision of the press is too poor, causing the mold to interfere; the strength of the punch is not enough, and the position of the large and small punches is too close so that the lateral force of the tool is unbalanced. At this time, the punch strength should be increased to enhance the guide protection of the stripper.
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