For pipe bending a tool such as a pipe bender has been used for a long time. The stores offer such tools of very different designs. That's just not necessarily to buy it - you can make a pipe bender with your own hands.
The pipe bender is used for bending all sorts of pipes at work and at home.
The pipe bender is the necessary tool in the household. You may not know about its existence for a long time, but it is the turn of a major repair, and the need for it arises. There is a need to bend the pipe to fix the plumbing or to make a trellis under the vineyard. If the machine is needed only sometimes and you do not want to spend money on its purchase, then it is time to design the pipe bender on your own.
Basic principles are flexible
The scheme are flexible pipes using a pipe bender.
The pipe is a round profile with a cavity inside. Its strength characteristics are determined by the property of the material, as well as the main dimensions - the external diameter and wall thickness. The main interest are metal pipes. Bending is hampered by the presence of a void inside. Simple bending, as a kink, leads to plastic deformation in the form of collapse (flattening) at the bend. The occurrence of deformation leads to the main condition of bending - the material must be bent in diameter, which can not be less than the allowable diameter of bending for a given pipe design.
The minimum bending Ø depends on the size of the pipe. It is normalized:
- For steel Ø up to 35 mm with a wall thickness of 2 mm within at least 5 Øs.
- With a wall thickness of more than 2 mm - at least 3 pipe Øs.
The bend itself depends on its purpose. At the same time, it is determined by such geometrical parameters as bending diameter and bending angle. Naturally, the specified bend Ø of a specific pipe should not be less than permissible.Back to table of contents
Basics of design benders
Table of bending radii of pipes.
The basic principles of bending put forward the following requirements for a pipe bender: bending should be carried out strictly according to a given diameter without deforming the material in the place of maximum bending; bending should be carried out only in one plane; bending must be done manually.
The first condition is satisfied only when bending around a roller with a given diameter. At the same time in the place of bending the pipe should be pressed against it. In addition, it should have a hole with a diameter equal to the diameter of the pipe.
There are three known easiest ways to bend around a roller. The first (template) is the easiest. It is based on a rigid attachment of one end of a bent material and the implementation of a bend due to the movement of the free end. The second method involves bending by running it on with another roller around the first one. The third method (crossbow) is based on bending by longitudinal movement of the roller defining the diameter of the bend, relative to the other two on the sides, which are guides.Back to table of contents
The design of a simple pipe bender
Scheme manual pipe bender.
The simple pipe bender can be made quickly, for carrying out urgent work. The template is fixed on any flat surface (horizontal or vertical). To simplify the mounting of parts, it is advisable to choose a wooden surface. The template is a board or a set of boards, rounded on a given diameter of the bend of the pipe. The thickness of the template is selected 10-15 mm greater than Ø pipes.
One of the ends is rigidly fixed in a vice. At the beginning of the contact of the pipe with the rounding of the template on the base is fixed stop. The stop is made of wooden bar with a thickness exceeding the diameter of the pipe. The stop is mounted so that the distance between it and the template is equal to the diameter of the pipe.
Bent material is passed through the gap between the stop and the template. The free end is manually bent around the curve of the template to a predetermined bend angle. If the pipe being bent has a small length or its dimensions make manual bending difficult, then an additional lever is inserted into the pipe channel from the side of the free end (metal rod, pipe of smaller diameter, etc.). Lengthening the end should reduce the force applied. When bending you need to make sure that the material does not slip off the template.Back to table of contents
Pipe Bending Machine
Scheme pipe bender arbaletnogo type.
The arbalet type pipe bender includes three rollers, one of which bends the pipe with longitudinal movement, and the other two provide fixation and direction along the edges. The whole structure is mounted on the frame (base). Two identical rollers are permanently fixed at the edges of the frame. A clamp is installed on their axes, ensuring non-rigid fixation of the material being bent in the pocket.
In the center of the base, with the help of bolts, two vertical posts of a U-shaped profile are installed on the sides, with inward edges to guide the carriage. The central roller with a rod in diameter along the tube is fixed in the carriage, in the form of a U-shaped construction of a metal strip. On the top shelf of the carriage it is necessary to make a nick with a rim for contact with the driver screw. The carriage with a roller is inserted into the racks. The diameter of the roller corresponds to the diameter of the bend of the material.
The movement along the central roller is set by a jack, which is a long threaded screw passing through a hole (with a similar thread) at the base of the jack. The base is fixed motionless on the bender racks. On top of the screw has a double-sided handle to facilitate rotation. At the bottom of the screw rests on the patch of the carriage.
When bent, the material is guided through the clips of the side rollers. Central down to the pipe. By rotating the screw handle of the jack, the central roller moves and bends the material. The sides have a diameter equal to the diameter of the central roller. The distance between the centers of the side rollers is recommended within 3-5 Ø of the roller.Back to table of contents
Scheme bender with rolling in the roller.
The pipe bender on its own can be made more versatile. Such constructions of pipe benders are made in the form of a metal frame in which a stationary coil and a lever with a running roller are located. The frame is made of two racks, which are fixed to the base at the last stage of manufacturing the device. On these racks, the axis of the fixed roller, having a diameter equal to the diameter of the bend, is rigidly fixed. The roller has a pocket on the diameter of the pipe. The distance from the base of the pipe bender to the center is approximately 15-20 mm greater than the radius of the roller.
The lever is made of two steel strips with a thickness of about 3-5 mm, and a width of 30-40 mm. At the top of the lever forms the handle. At the bottom of the strips are made holes for mounting on the axis of the stationary coil. At a distance equal to the diameter of the fixed coil, holes are drilled in the posts for the axis of the rolling roller.
The run-in roller is rigidly fixed on its axis and is installed in drilled holes in the strips. A lever with a roller mounted in it is located on the axis of the fixed coil. After that, the axis is firmly fixed in the frame racks. Fixing the stationary coil to its axis should ensure its immobility under load, so the connection should be made by welding.
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The length of the lever handle should be at least 25 cm, and the desired length of the entire lever to facilitate bending is recommended to provide an additional extension.
If you need to make a pipe bender, you should prepare the tools and equipment in advance:
- welding machine;
- electric drill;
- hammer (sledge hammer);
- a hacksaw;
Make a pipe bender with his own hands quite under the force of many. It is possible that some details should be entrusted to a specialist, but most of the work can be done by yourself.