A NEW TECHNIQUE FOR BENDING TUBES:
BENDING BY HYDROFORMING

Socratech, an expert in the hydroforming field, has already developed a full range of hydroforming machines specifically used for the industrial production of metallic fans. Socratech assures a follow-up from development through manufacturing of typical parts to production runs on the machines.
Socratech, working one on one with its customers and their concerns, has often been faced with technical requirements linked to the conventional bending technique (achieved by a mechanical drawing or stretching of the material). This is why it has recently developed a new bending technology by hydroforming. This revolutionary and extremely high performance technique offers you the capability of making paths in space limited only by your imagination.

CONVENTIONAL BENDING TECHNIQUE

The principle of the conventional bending technique is a mechanical drawing or stretching of a tube by using tightening jaws and outer dies either with or without an inner drift.
This technique causes a reduction in the thickness of the tube's wall on the outer radius of the bend and an increased thickness inside the radius.
It is not readily applicable to thin-wall tubes because it causes an elongation leading up to cracking on the outer wall of the bend and a folding of the inner wall.
A straight tube of minimum length is necessary on each side of the bend to be held by tightening jaws.
A 3-dimensional bend must be made by a series of 2D bends and, therefore, requires a long length of tube and a very large space.
Thanks to this new technique developed by Socratech, you won't have to cope with all these disadvantages anymore

PRINCIPLE OF THE NEW BENDING TECHNIQUE

The principle of this new bending technique is based on the principle of hydroforming.
The principle is to create asymmetric waves by hydroforming. The asymmetric wave when formed creates an inflow of more material on one side, thereby bending the tube.

ADVANTAGES OF THIS TECHNIQUE

  • The thickness of the bend's outer wall remains constant (with a reduction in thickness of less than 10%). Therefore, a weakened area is not created on the outer surface of the bend. Contrary to the conventional bending technique, the tube thickness may be easily reduced, assuring a significant saving in material and weight. In addition, tube cross-section variations are almost non-existent with hydroforming, while they are a very important problem in conventional bending techniques.
  • Depending on the height of the waves and the interval between the asymmetric waves, you may alter at will the radius of curvature and, therefore, create curves of variable radius.
  • For the same radius of curvature, you may according to your application either make more but smaller folds or less but larger folds.
  • The bend is created on the side where the asymmetric wave height is the highest. And, if you rotate this asymmetry, you change the curvature.
    Therefore, thanks to this technique, you may change the axis of rotation of the curvature in the same bend and thus make any path in space.
  • In addition, these bending asymmetric waves may be blocked to prevent any flexibility in the bend or be combined with the flexible waves.
    This combination allows making alignment compensations on the part in three axes and/or the absorption of vibrations or expansions. As a result, you may obtain in a single step the functional and dimensional characteristics of your part (bends + bellows).
  • There is no tightening jaws as in the conventional technique. The bend may, therefore, be placed very close to another operation or a premounted accessory.
    In addition, there is not an ″extra″ length after the bend and, as a result, a significant saving in material losses and cutting operations. Thus, the tube work may be performed immediately on the final length..
  • The turbulences inside the bend may be diminished by joint waves. And, thanks to hydroforming, the tube diameter may be increased inside the bend,
    thereby reducing load losses encountered with a conventional bend..
  • The number of machines allowing a part to be made significantly decreases because you can make bends and bellows at the same time with a single hydroforming machine, and avoid cutting operations on pipe ends. Consequently, the machine budget is not only really lower, but also operating costs (floor space, scraps, labour, maintenance with very low tooling wear, etc.).





SOCRATECH DEVELOPED MACHINES

Socratech is currently developing a wide range of machines to fit each specific usage:

  • Wave by wave machines, allowing the generation of asymmetric waves for bending and flexible waves.
  • Single-pass machines, allowing a bend to be made in only one pass.
  • Automatic multi-bend machines, allowing 1 to 8 bends to be automatically made on the same part.

APPLICATION FIELDS

The application fields for this new technology are, of course, not only the automotive and aeronautic industries, but also the pipe and plumbing industries. Thanks to a small worksite machine, you will be able to tailor your bends on the spot and to measure without welding.
Other application fields are surely going to exploit this new bending technique recently patented because it offers capabilities which could not be imagined up to now.

DEVELOPED MACHINES TYPES
RATES
Wave by wave machines
3 seconds / wave
Machines 1 cintre en une seule passe
12 seconds / bend
1 bend machines in single pass
10 à 20 sec./ 4 bends