New bending machine: advantages

Versatility of bending machine, that can bend large size profiles, as well as profiles with small dimensions and radii, with its combination of considerable useful length and elevated stiffness of the supported shafts with a centre distance between the bending rolls having a wide variability range due to the converging straight-line guides.

Longer machine life because of the optimal distribution of the forces. Hydraulic pipe bender adjustment of the bending axes speed makes it possible to position the rolls with maximum precision. For example, during multi-pass bending, it is possible to rapidly approach the required radius and the subsequently finish the bending with maximum precision finely adjusting the position of the bending rolls. A longer life of the machine because of the optimal distribution of the forces.

The excellent geometry of the Alpha series, permits, with the same performance as a bending machine of the competition, considerable energy saving (on average the power required is halved).

Square tube bending has an innovative multi-axis positioner that permits a completely independent handling of the moving parts of the bending machine where it is applied.

The operator interface is incorporated in a panel of appropriate dimensions, that encloses in a single instrument all that is necessary to ergonomically manage the bending machine, avoiding confusing and bewildering indications caused by many devices spread out over the machine. The PQ10 is the latest electronic interface, designed specifically to meet the management requirements of pipe bending machines with more than 3 separate axes. With the touch-screen display and the Microsoft Window. CE operating system the use of the multiple PQ10 applications are intuitive and fast .

single axis positioning, setting the required dimension on the main screen and activating the actuator of the axis.

sequential multi-positioning of axes, used to carry out the movement of several axes continually and in sequence up to the required dimensions.

It is possible to set up to a maximum of 10 dimensions for each axis; the control electronics permit positioning of the bending axes with a precision of 0.1mm, whereas for auxiliary axes the precision is 1mm.

Possibility, at any time, to rotate the machine synoptic panel by 180°, to adjust the screen to the requirements of the operator.

The PQ10 also includes an advanced analysis system for self-diagnosis of any failures and/or maintenance operations on the control circuit. When necessary a warning is displayed with a description of the failure and a photo of the area requiring attention.

Upon request the metal bending machines can be supplied with a tele-assistance system for prompt service in any part of the world.

INNOVATIVE CONTRUCTION PHILOSOPHY IN BENDING MACHINE

In a globalised world it may seem trivial to underline the origin of a product, but nowadays it’s important to assure clientele that entire production is all studied, designed and assembled in Italy. Especially in these times of worldwide crisis in industry it is important to point out that the company has continued to develop, refurbishing with a new high quality management system, SAP, worldwide leader in software solutions for business. Furthermore, a lot of energy has been spent in finding new technical solutions in the manufacture of the machines, in testing new products for special processing and in continual updating of the CNC-i numeric control–core and real added value of all bending machines.

LAMIERA 2010 exhibits a synthetic but significant series of high quality products manufactured by the company that has been UNI ISO 9001 certified for many years. The construction principle applied by most manufacturers consists in two angle rolls, mounted on pivoted levers on a central pin, that follow an orbital path, a third fixed roll overlays these two rolls, in a central position in relation to the other two.

CNC bending machines geometry is very common because production costs are less. However, this system has certain equally evident drawbacks, due to the forces involved, that subject the structure to considerable stress concentrated in a single point: the central pin. This is the weak point of the entire system, because, even if largely over-dimensioned , it will never have the necessary stiffness to ensure an even distribution of the stress it is submitted to.

The company has built and patented an innovative drive and support system of the roll-carrier shafts on slides with a linear stroke, which is much more precise and stiff than the system previously described. To this important development the possibility is added to be able to apply independent supports, that restrain the ends of the shafts greatly restricting deflection. The slides with their straight-line stroke act as the base to assemble the supports, so that also during adjustment of the slides, the shafts are always rigidly restrained on three points.

Possibility to bend section bars with a double pipe bending strength, compared to a bending machine with conventional drive system at the same cost.

The possibility to have an immediate saving on the purchase of a bending machine, which is much smaller, but appropriately dimensioned for the steel bending needs required.

Considerable saving on cost and on the handling of fixtures, much less cumbersome and with higher dynamics in the operations.

Requirements in tube bending

The three principal requirements in tube bending are simply: machine, operator and tooling.

All three factors must be especially good to work with thin wall tubing on tight radii. Too many facilities still depend on the operators genius to compensate for near useless tooling. Poor tooling results in longer set-up time, scrapping of expensive tubing, poorly bent tubes and fail to produce an acceptable pipe bender. Highly competitive custom tube bending companies realize cheap and inferior tooling is the most expensive they can buy. Interlock tooling represents the ultimate in tube bending tooling. Complete interlock tooling, although developed and successful for numerical control tube benders, has proven advantageous for conventional machines. Each tool of the matching set is laterally locked in alignment. The clamp die is keyed and locked to the bend die, the wiper die located and locked to the pressure die, and the pressure die in turn is locked in alignment to the bend die.

Field reports have confirmed several advantages of interlock tooling. The clamp die, with all the hydraulic pressure available to it, will not crush or even mark the tube, thereby providing vastly improved gripping properties. Bend die and pressure die marks on the top and bottom of the tube are completely eliminated. In 23 instances tested, set up averaged one-third the time allotted for conventional tooling. A 32% reduction of scrap was recorded over previous runs using conventional tooling.

The five pieces of tooling (bend die, pressure die, wiper die, mandrel and clamp die) must all be close-tolerance excellent tooling. The bend die should have a maximum run out at the bottom of the bend groove of not more than . To help prevent tooling marks on the top and bottom of the tube bending machines, the bend groove should be deeper than half the tube diameter. The bend groove should be dead round and the diameter should measure 10% timeís wall thickness over tube diameter. The clamping area, unless cleated or with other provision such as flaring, beading, etc., should be three to six times tube diameter with a sandblasted or rough finish. The diameter of a clamp area should not be undersize more than 10% of wall thickness. Grip or pinch clearance should be held to a minimum. To permit the bend die to be used on right and left hand machines, the counter bore and keyway often are machined on both sides of the die. Centerline height must be maintained for both sides.

BENDING WITH BALL MANDREL AND WIPER DIE

When the radius of the bend is smaller and/or the wall is thinner, it becomes necessary to use a

ball mandrel and wiper die. The wiper die is used to prevent wrinkles. The ball mandrel performs like a plug mandrel. The balls are used to keep the tube from collapsing after it leaves the mandrel shank.

Bending issues are enlarged when making tight bends or with thin wall tubing. It becomes more difficult to retain the material during compression.

The pressure is so intense the material is squeezed back past tangent and buckles. This area must be supported so that the material will compress rather than buckle; this is the prime purpose of the wiper die. Note, the wiper die cannot flatten wrinkles after they are formed; it can only prevent them.

Bending thin wall tubing - requirements for the bending of thin wall tubing with tight radius bends of centerline radius equaling the tube outside diameter have become more common in recent years.

To increase the problem, new alloys have been developed that are extremely difficult to bend. The proper bending machine, good tooling, and a trained operator can make all the difference.

To facilitate this type of tube bending, the material to be bent should receive special consideration. To help maintain the consistency of the tubing dimensions and characteristics, the entire material required for a given job should be acquired from one supplier, preferably even from the same lot or heat number. Premium-priced close-tolerance tubing should be considered. It often saves many more times its added cost. It may be necessary on occasion to size certain tubing before bending.

There are many pipe bending machines but only a few are capable of thin wall, 1 x D bending.

Even those machines best suited for this special bending must be in excellent condition and of a size large enough to assure rigidity. The machine must be capable of retracting and advancing the mandrel with the clamp and pressure dies closed. A hydraulically actuated pressure die is desirable. One feature of this system is that it provides identical pressure on the tube regardless of wall variation.

A pressure die boost counteracts the drag of the pressure die, mandrel and wiper die. It pushes the tube into the bending area, preventing excessive wall thin out.

Without a pressure die boost, the thinning that normally can be expected is about three quarters of the elongation of the outer wall. Companies specialized in steel bending automation for a broad array of fabricated products, includes CNC tube benders, tube measuring equipment and complete cellular integrated systems.

BENDING TUBE

A bend die, clamp die, and pressure die are the minimum essentials for tube bending. The bend die helps to prevent the tube from flattening and forms a given radius of bend.

The clamp die holds the tube in position while bending. The pressure die forces the tube into the bend die.

Springback is excessive when a mandrel is not used. This should be considered when selecting a bend die. Springback is the term used to describe the tendency of metal that has been formed to return to its original shape. Springback will cause the tube to unbend from two to ten degrees depending on the radius of bend, and may increase the bend radius of the tube. The smaller the radiuses of bend the smaller the springback.

The tube may kink or buckle, this may be due to hard material which will not compress on the inside radius of the bend. The material, not being able to compress, pushes in toward the centerline of the tube. This condition can be corrected (provided the tube is not too hard) by proper set up of the tooling. A plug mandrel is indicated if the tube buckles and is still within the wall factor and the diameter of the bend.

The purpose of a plug mandrel is to prevent the tube from flattening and to bend without wrinkles or kinks. The mandrel is held in a fixed position while the tube is pulled over it. The tube stretching process is localized on the outer radius of the bend and the material is work hardened to retain its shape and not flatten. The material stretching is done on the forward tip of the mandrel. This force, acting on the mandrel tip, supports the inner radius of the bend, holding it firmly into the bend die groove. CNC bender is used on CNC benders from 0.25" inch to 6" inch tube bending machines.

The pressure die should be adjusted for a light pressure against the tube. The purpose of the pressure die is to keep the tube against the bend die through the duration of bending. The pressure die also keeps the mandrel from bending and maintains a straight tube between tangent points of bends (the portion of ubing left on the mandrel after steel bending). The location of the mandrel affects the amount of springback. The mandrel in a forward position (toward tangent) will stretch the material on the outside of the bend more than is necessary. This increases the length of material on the outside beyond that which is required to make a bend. When the bent tube is removed from the bend die, it will conform to the die and there will be little or no springback.

TUBING BENDERS

Tubing benders come in many sizes, for use in everything from heavy construction to auto building to home landscaping. They range from a 16-ton hydraulic pipe bender to a handheld bender for small-gauge copper and aluminum tubing. All of them, however, use one of four basic methods. Ram bending is the cheapest and easiest method. Tube benders are restrained at two ends and a ram deforms the pipe in the middle. This is suitable for light gauge tubing only. Rotary draw bending is the most commonly used method, and maintains the diameter of the pipe without deformation. In this method, the tube is drawn through a stationary counter-bending die onto a forming die of a specified radius. These tube bending machines are used in the formation of exhaust pipes, process pipes, and any aluminum or stainless steel application where interior deformation can't be tolerated. Bending is similar to rotary draw bending, except that the interior of the tube is supported by a flexible mandrel. The mandrel bends with the tube, ensuring that the interior diameter is not deformed. Ring roll bender is used for bending pipes and tubes with a large diameter. There are three rollers, two on the bottom and one on the top. As the pipe is rolled through, the top roller exerts a downward pressure, bending the pipe. The pressure of the top roller can be adjusted manually or hydraulically, and either two or all three rollers can be powered. This method is used to make drum barrels, awnings, and other circular shapes.

For a tube bending, two things happen to metal. The outside wall is reduced in thickness due to the stretching of the material and the inside wall becomes thicker due to the compressing of the material. The material actually is formed approximately about the centerline of the tube. The material that forms the outside of the bend has further to travel and therefore is stretched; the inside of the bend has less distance to travel and is compressed.

When the ratio of the tube diameter to wall thickness is small enough, the tube can be bent on a relatively small radius. Excessive flattening or wrinkling of the bend should not occur. The outside and inside of the bend tend to pull towards the centerline of the tube. Two factors that help prevent this from happening are a grooved bend die, which supports the tube along the centerline and the natural strength of the tube.

Tube and pipe rollers

The tube and pipe roller or roll bender machines consists of manual or electronic driven single pinch ring roller machines (noting some have a hydraulic top roll with DRO) and hydraulic driven double pinch models with two hydraulic bottom rolls. The company has a very diverse line of angle roll bender machines to bend tube, pipe, angle iron, solids, squares, and much more.

The manual pipe bender machines consists of two manually driven ring roll benders for bending up to 1-1/4" tubing. These are great tube roller machines for the hobbyist or metal artist. The company also has several ring roller machines that are electronically driven with variable speed inverter drives. These ring roller machines have greater capacities and are easier to operate with two driven bottom rolls. These powered tube roller machines can bend vertically or horizontally for larger section angle bends. All versions in this category have manually adjusted top rolls and are considered single pinch style machines.

The single pinch angle rolls bender line with hydraulic down feed of the top roll has digital positioning readouts for repeatability. The tube benders in this category have three driven rolls for extra power. These roll bender machines are perfect for production fabrication settings where the fabricator is making hay hoops, spiral stair cases, and much more.

Finally the company offers two versions of double pinch angle rolls, hydraulically driven roll benders with hydraulic positioning of the two bottom rolls that are coupled to two separate digital readouts. These angle roll machines have three hydraulically driven rolls. We also have two angle bending machines that have hydraulically driven rolls, hydraulically positioning bottom roll, as well as hydraulically driven lateral guide rolls. These ring roller machines are for bigger section bending projects or for more structural applications. A double pinch bender allows the operator to pre-bend and post-bend the material saving the fabricator time and money. These roll bender machines are easy to use, cost effective, and built for decades of service.

Features:

· Bending capacity to 6″

· Bend any angle to 180° with independent material spring back compensation for each bend

· Bend to CLR as small as 2.5D

· Ideal for producing consistent quality bends in large diameter pipe, tube, squares, rectangular, solids and other profiles

· PLC touch screen control offers easy access to operating modes, programming, system diagnostics and multiple language capability

· Patented quick-change tooling system with multiple radii available

· Remote foot pedal for hands free operation