Bending machines: principle of operation, types and their characteristics

A bending machine is a mechanical device that is used to bend metal sheets. This device has found widespread use in the machine building system, construction and economic spheres. Thanks to the listogib, the task of making products in the form of a cone, cylinder, box or profiles of closed and open contours has been greatly simplified.

The bending machine develops a certain force and has properties such as bending speed, product length, bending angle, and so on. Many modern devices are equipped with a program control unit, which improves their productivity and usability.

Manipulation, due to which a sheet of metal takes shape according to given parameters, is called bending or bending. Plate bending equipment is suitable for working with any metal: steel, aluminum, galvanized iron or copper take the required shape due to the fact that the surface layers of the metal are stretched out at the workpiece and the inner layers are reduced. In this case, the layers along the bending axis retain their original parameters.

Besides bending, on a sheet bending machine, if necessary, cutting is also performed... This is how finished products are obtained - various types of cones, gutters, figured parts, profiles and other structures.

The design of the bending machine is quite simple: it is equipped on a rectangular frame made of a durable steel channel. On the frame there is a pressure beam and a punch that rotates horizontally. The scheme of a listogib with a rotary frame will help you to clearly see the principle of its operation. Placing a metal sheet on a bending machine, it is pressed with a beam and a punch is installed, which bends the material extremely evenly and at a given angle.

The characteristic of the work of the listogib depends on its design, when the bending is obtained by turning the punch or by pressure from above. The bending angle can be controlled visually or set on the machine special limiters according to the specified parameters. On bending machines equipped with program control, for these purposes, 2 sensors are installed at the edges of the bent sheet; during bending, they regulate the level of the bending angle.

Metal bending equipment can be mini-sized for manual use or stationary used for performing work on an industrial scale. The sheet bending machine can be two-roll, three-roll or four-roll. In addition, the bending machine is available with a swivel beam, or a horizontal automatic press, which functions with the help of hydraulics, works as a bending tool.

Universal hydraulic bending machine It is used for table stretching of a sheet or bending parts along the length of the table - the productivity and accuracy of such machines is quite high.

Such equipment has a low cost and is the most affordable for purchase. In addition, hand benders are small, lightweight and can be easily moved. The process of bending a sheet of metal is carried out using the manual force of the operator working on the machine. The manual machine has a system of various levers, but thick sheets of more than 1 mm are difficult to bend on them.

The advantage of this approach is that it is much more convenient to hold a large-sized sheet of metal together, and fixation and deformation are performed at this time from both sides at once. In some manual models of plate bending machines, a rear feed of a sheet of metal is provided, which allows each operator to freely approach the machine without interfering with a partner.

In machines for bending metal of a mechanical type, the press is moved by an electric motor. Part dimensions, bending angle, and so on can be set manually or automatically. It is possible to work on mechanical type plate bending machines, taking into account the material and its thickness. For example, steel sheets should not exceed 2.5 mm thickness, stainless steel is used within 1.5 mm... However, there are also such models of modern mechanical-type bending machines, on which it is possible to make blanks from metal with a thickness of up to 5 mm.

An important feature of mechanical bending machines is that the sheet feed angle can be set without restrictions. Such machines are highly reliable and simple in design. This is a versatile device that can be quickly rebuilt according to the specified parameters of the processed metal sheet.

The machine weighs 250-300 kg, it does not have great mobility, but the bending angle can be created within 180 degrees, which is difficult to achieve in manual models.

These machines allow you to make products according to the specified geometric parameters. The accuracy of bending work on a hydraulic machine is much superior when comparing the results obtained when working on a manual or mechanical machine. In addition, the hydraulic system greatly facilitates the process of work, since it completely eliminates the use of manual efforts of the operator. The most important features of hydraulic bending machines are their high power and performance. They are capable of handling metal with a thickness of 0.5 to 5 mm.

The essence of the machine is that the metal is bent using a hydraulic press. The power of the machine is enough to work with thick sheets... The design of the hydraulics provides the machine with fast and quiet operation, as well as the reliability and infrequent maintenance of the hydraulic cylinders. However, in the event of a breakdown, the hydraulics cannot be repaired on their own, since such a cylinder can only be disassembled at a special stand, which is available only in service centers.

For the manufacture of complex models and configurations of sheet metal products, large-sized electromechanical equipment that is permanently installed in production shops or specialized workshops... Such machines have a complex structural arrangement, their mechanism comes into operation due to the operation of the electric motor, the drive system and the gear motor. The basis of the listogib is a steel frame on which a rotary mechanism is mounted. The bending of the material is carried out by a bending knife, consisting of several parts made of high-strength steel - this design of the knife allows you to significantly save money in the process of repairing it.

Electromechanical bending machines - these are machines equipped with program control, therefore, all operating parameters are set in automatic mode. A computer program regulates the entire working process, therefore, the safest conditions are created for the operator working on such a machine.

If necessary, automated control can be dispensed with, and then the sheet metal in the electromechanical machine can be fed manually. The parameters of the finished product can also be set. Due to the high precision and power on such a machine, products are made from steel sheets - these can be parts of the roof or facade, ventilation system, drainage system, road fences, signs, stands.

A press brake that bends a sheet of metal using an air compressor and pneumatic cylinders is called a pneumatic press brake. The press in such a machine sets in motion compressed air, and the device of most of these models is based on the principle of a swing beam. Such machines are permanently located in production facilities., their work is accompanied by a specific noise. The disadvantages of a pneumatic listogib include its inability to work with thick sheets of metal, and this is due to a lack of machine power. However, such listogibs are unpretentious, have high productivity and versatility.

The process of working on a pneumatic press is fully automated, so the operator's labor costs are minimal. Pneumatic equipment is reliable in operation and does not require expensive maintenance... But if we compare it with a hydraulic analogue, then preventive work on pneumatic models is performed more often. In addition, the cost of pneumatics is much higher than that of hydraulic machines.

A machine in which a sheet of metal for processing is pressed on a work table with the help of a powerful electromagnet is called an electromagnetic bending machine. The force with which the bending beam is pressed during operation is up to 4 tons or more, and at the moment when the bending knife does not work, the fixing force of the metal sheet on the work table is 1.2 t... Such equipment has compact dimensions and low weight. The reliability of the machine lies in the simplicity of its design, its control is fully automated by a software device, and the absence of cyclic friction processes during operation makes it possible to increase the wear resistance. The magnetic bending machine has great power, but is inferior to hydraulic counterparts.

Of all the options for sheet-bending equipment, electromagnetic machines are the most expensive in terms of cost, in addition, in the process of operation they consume a large amount of electricity, so the cost of finished products becomes high.

Devices for bending sheet metal on the sales market are represented by models of Russian production, America, Europe and China.

Consider the rating of mobile bending machines.

• Model Jouanel made in France - the maximum metal thickness for processing is 1 mm. The machine is suitable for complex products. The resource of the knife is 10,000 rm. The cost of repair is high. A model for working with sheets of 2.5 m costs from 230,000 rubles.

• Model Tapco made in the USA - a fairly common machine that can be used in a construction site. It has high productivity, the maximum metal thickness for processing is 0.7 mm. The resource of the knife is 10,000 rm. The cost of the machine is from 200,000 rubles.

• Model Sorex made in Poland - depending on the brand, it can process metal from 0.7 to 1 mm thick. Machine weight from 200 to 400 kg. The machine has established itself as a reliable equipment, its average cost is 60,000 rubles. Capable of performing even complex profile configurations.

• Model LGS-26 made in Russia - a mobile machine that can be used in construction work. The maximum metal processing thickness does not exceed 0.7 mm. The cost of the machine is low, from 35,000 rubles, in the event of a breakdown, repairs will not require large investments.

And here is the rating of stationary bending machines.

• German electromechanical Schechtl machine - models of the MAXI brand process sheets up to 2 mm thick. Possesses software, has 3 working segments of beams, with combined use of which it is possible to perform different operations without additional reconfiguration of equipment. The average cost is 2,000,000 rubles.

• Czech electromechanical bending machine Proma - the models have a bending capacity of up to 4 mm, control and adjustment are automated, and the rolls have high wear resistance. The electric motor is equipped with a braking device, which protects the machine from overloads and allows it to work with high precision. The average cost is 1,500,000 rubles.

• Hydraulic Modification Machine MetalMaster HBS, produced at the production of "Metalstan" in Kazakhstan - can process metal up to 3.5 mm thick. It has great performance and is intended for industrial production. The machine works with a swivel beam and is equipped with automatic control. The weight of the machine is between 1.5 and 3 tons. Average cost from 1,000,000 rubles.

When choosing a plate bending machine, determine which sheet metal size you need it for. Most often, there are machines for a sheet size from 2 to 3 m.

Next, you need to decide on the power of the device. For example, on a simple mechanical listogib, you can bend galvanized steel up to 0.5 mm thick, but a sheet of stainless steel of the same thickness can no longer be processed, since there is not enough safety margin. That's why it is advisable to purchase equipment that has a slightly larger margin of safety than it is planned to use... That is, if the working parameter of the material is 1.5 mm, then you need a machine with a bending capacity of up to 2 mm.

Many modern machines are used to work with painted materials. Such metal is used for drainage, gutter caps, roof gutters, and so on. When forming such products on the machine, it is important not only not to scratch the material, but also to bend the edges by 180 degrees. Such manipulation can only be performed by those machines that have a special milled groove, or together with the machine you purchase a folding closing machine.

Additional accessories are often supplied to modern sheet bending machines, allowing you to perform the required bending. for wire or to make corrugated board. Such components increase the cost of the machine, sometimes it is necessary for your work.

Before starting work on the machine, you need to familiarize yourself with its device and study the rules of operation. The new bending machine will bend the products correctly, along a verified straight line, but over time, if preventive adjustment and adjustment were not carried out, the bed at the bending machine sags, and the finished products are obtained with a screw... If the equipment on the machine provides for adjustment, then the screw effect can be removed by adjusting the clearances by tightening the adjusting screws. The practice of using listogibs shows that the bed does not drop down to 2 meters for models with a short frame, but the longer it is, the greater the likelihood of deflection.

Do not forget also that the period of the bending knife is limited and after its expiration the part must be replaced. Such equipment has a warranty period of 1-2 years. If the mobile machine breaks down, you can contact the service center for its repair.

As for stationary bending machines installed at enterprises, regular preventive and overhaul repairs are carried out for them at the place of installation of this equipment.

How to choose the right bending machine, see below.