Profile pipes of square or rectangular section are widely used in construction and repair. Arbors, sheds, greenhouses, frames for various structures, fences are made from them. To give the element a curved shape, use a special device — a pipe bender.
Complex spatial structures are produced by specialized workshops on high-precision powerful machines. At home, hand tools of industrial production or home-made are more often used. If you need to bend several elements, it is advisable to make a pipe bender for a profile pipe with your own hands. A simple reliable device will cope with the task no worse than the factory one, while it will cost several times cheaper.
The principle of operation of the pipe bender
The pipe bending machine is designed to bend pipes at an angle of up to 90°. Such processing of a rigid all-metal element makes it possible to avoid welding pipes and creating threaded connections.
When bending, the principle of mechanical cold deformation is used. The material is not adversely affected by high temperatures. Rolled metal is placed between the static rollers of the device, and the movable pressure roller creates a force that bends the profile at the desired angle.
To avoid deterioration of technical characteristics and destruction of the metal, the bending radius of the pipe is limited.
Its minimum value depends on the type of material — steel, copper, aluminum — and wall thickness. In this case, the thinning of the section does not exceed 20–25%. As a result of plastic deformation, the profile acquires a curved shape without loss of strength.
To obtain a section of the angular configuration, use the local impact tool. The force is applied pointwise. The bend is formed by extrusion.
A profile bender differs from a conventional round pipe bender in that it is designed to deform a profile that is more resistant to bending loads. For the manufacture of arcs or arches, the workpiece is drawn on a rolling machine with one or more rollers and a large bending radius.
Types of pipe benders and their design
The construction industry produces a wide range of roll forming machines. They are designed for processing rolled metal with various technical characteristics and solving specific problems.
Compact mobile devices are used for the manufacture of arc elements from profile pipes of small sizes. A hand tool works due to the muscular efforts of a person.
Varieties of manual pipe benders:
- with a leading central shaft;
- with movable edge roller;
The design of a manual pipe bender with a leading central shaft consists of a base, two support rollers and one movable one. The impact is regulated by a clamping screw collar inserted into the upper part of the mechanism.
The pipe is pulled through the shafts manually using a handle and a chain fixed on the roller axles. The pressure is increased by lowering the pressure bolt. The profile gradually bends and takes the form of an arc.
The manual profile bender can be equipped with a movable end roller. It is fixed to a part of the frame connected to the bed with powerful loops.
The height of the lift is changed with a jack, raising the edge of the table. The handle for pulling metal products is attached to the central fixed roller.
For the manufacture of steeply curved sections from a pipe 20x20, 30x20 and 40x20 mm with a wall thickness of up to 1.5 mm, rotary manual pipe benders are used. They allow you to bend the profile at an angle of up to 360 °.
The device is fixed on a frame or table horizontally, a metal structure is inserted into the groove of the desired size. By turning the long handle, the profile is pressed around the template and a bend is formed.
In such pipe benders, the force is pumped by a hydraulic motor. Hydraulic cylinders transmit pressure up to 12 tons to the pipe section, which makes it possible to bend even large workpieces.
Hydraulic pipe benders are produced by the industry in two versions:
- Manual. The pipe is inserted into a replaceable template of a suitable size — a support shoe that securely fixes the product during bending. The hydraulic cylinder is actuated by a handle, returned to its original position by means of a check valve. The tool is portable, used for processing profiles up to 50 mm in size.
- With electric drive. More powerful devices allow you to bend a pipe with a cross section of up to 150 mm and a wall thickness of up to 3 mm. Electric motors are equipped with two-stage telescopic hydraulic cylinders. Due to this, a large force is developed at the end of the working stroke.
Hydraulic pipe benders have high productivity and process structures with high precision. To give the workpiece a given bending angle, a graduated scale is located on the device body.
Electric roller professional profile bending machine is a technological equipment for the manufacture of curved thin- and thick-walled metal structures. Allows you to automate the execution of large volumes of work.
Electromechanical pipe benders can be manual or stationary. The former are used for bending pipes with a diameter of up to 50 mm in conditions where power is available. The second are large-sized machines with powerful engines installed in industrial workshops. They are controlled by CNC operators.
Profile bending is formed by one or more shafts. According to the bending method, pipe benders are distinguished:
- winding — the element bends when rotating around a fixed pulley;
- rolling — the curvature of the part is given by a movable roller, which presses it against the template during the passage;
- rolling — the profile is pulled through three rolls, two of which are stationary, and the third moves relative to the others;
- extruding — works like a crossbow, bends the workpiece with a retractable punch with a nozzle made for a pipe of a certain size.
The steel profile is most often bent by rolling machines, where the force is distributed more evenly.
In roller pipe benders, rolled products of square or rectangular section experience less deformation, at which the stability of the walls is maintained.
Do-it-yourself manual pipe bender for profile pipes
To bend a profile pipe with small cross-sectional dimensions without a pipe bender, craftsmen use templates of the desired curvature made of metal or wood. The workpiece is pressed manually to the edges of the segment, rigidly fixing one end.
The thin-walled element can be deformed when heated. The area is heated with a blowtorch to a temperature of 350–400°C and, using manual force, the profile is arched.
If you use simple methods that do not allow product parameters, you can design a manual roller pipe bender for a profile pipe. With its help, arches and arcs are made for canopies, greenhouses and other structures of complex shape.
Required materials and tools
To make a device, you will need:
- channel No. 8 or No. 10 for a rigid frame;
- 2 castors made of hardened steel with steps for profiles of different heights or restrictive rings;
- notched roller for the movable shaft;
- finished bearing units;
- 2 or 3 gears or “sprockets”;
- steel chain;
- clamping screw;
- thin pipe for the gate;
- welding machine;
- a hammer.
Still need cotter pins, nuts, threaded bushings, washers. To process the finished structure, paint and lubricant will be required.
The drawing is the basis that will help you make a pipe bender without gross errors. This is especially important when working with metal.
Ready-made drawings are posted on the Internet. With sufficient experience, they are easy to understand and adjust to your capabilities.
You can imagine an exemplary pipe bender device when studying the factory analogue, and then develop a detailed diagram of your model.
Construction assembly steps
The sequence of operations for the manufacture of a homemade roller pipe bender:
- Cut the channel according to the dimensions of the racks and base.
- Drill holes in the frame parts for mounting the rollers.
- Weld the support frame with the uprights from the channel.
- Cut and weld a body with holes for installing the drive roller from the channel. The shaft should rotate easily inside.
- Fasten the clamping screw to the resulting box using bearings. Drill a hole in the top of the screw for the gate.
- Insert a housing with a drive roller between the uprights. The structure must move freely vertically. Fasten the cover with a screw nut from above.
- Screw the bearing units to the frame.
- Insert the collar into the hole of the clamping bolt.
- On the shaft axis from the outside, put the gears on the key or taper split bushings with nuts. Attach the third “asterisk” to the rack. Put on the chain, press the sleeve for the handle.
- Carry out trial tests, if necessary, make adjustments.
The last step is to disassemble, clean the metal from burrs, paint the fixed parts, reassemble. Assemblies that are subject to friction during operation should be treated with Litol or other grease.
To bend the workpiece, it is placed on fixed rollers, the clamping screw is lowered to the stop and pulled with the help of a rotating handle alternately in one direction and the other.
After each rental, the screw is tightened with a collar. When the arc has acquired sufficient curvature, the screw nut is fixed with a lock nut. This will allow you to bend several arches with the same radius.
Such a homemade pipe bender can be used even for professional purposes. He will “master” profiles up to 60x60 mm in size or at the same time 3 pipes with a section width of 20 mm.
Details of the manufacturing process of a manual machine can be seen here.
Hydraulic Pipe Bender
The use of hydraulics greatly simplifies both the operation of the pipe bender and its design. The simplest device is a frame with two support rollers. The mechanical effect on the profile is exerted by a jack with a shoe attachment.
The hydraulic fixture is designed for pipe bending, as the deforming force is transmitted to a short section.
Tools, materials and drawing
For self-production of a hydraulic pipe bender, you will need:
- welding machine;
- hydraulic jack;
- channel and corner for power frame;
- stop shoe;
- rollers or guides.
Scheme for assembling a simple hydraulic pipe bender:
- Cut the corner to size and weld the frame in the form of a support platform with uprights.
- Weld a horizontal frame from the channel to the frame.
- To adjust the bending radius, drill several holes in the frame.
- Set the rollers to the desired position.
- Put the shoe on the jack rod, install the hydraulic mechanism in the lower part of the frame.
To bend the workpiece, it is placed between the segment and the support rollers. Gradually increase the load with the jack lever.
When the desired bending angle is obtained, the bypass valve of the hydraulic cylinder is opened, the jack piston is lowered and the finished part is removed.
For thin-walled profiles, mechanisms with a carrying capacity of 5–8 tons are used. To bend powerful pipes, hydraulics must have great capabilities — up to 12 tons.
Video about the manufacture of a hydraulic pipe bender:
Hydraulic homemade pipe bender is easy to disassemble. The jack can be replaced with a more convenient or powerful one. To make it easier to perform all operations, the design is sometimes adapted for horizontal operation.
The most common bending defects with a hydraulic pipe bender are the formation of cavities, corrugations, cracks or profile breakage. To prevent this from happening, it is recommended to use factory-made shoes. They are made of durable steel, centered and evenly transfer the load to the pipe walls.