Technical Field

[0001 ] The invention relates to a mandrel to support a multi-wall pipe throughout its length which is obtained from coated metal sheet and the mandrel adjustment assembly to set pipe diameter by drawing with a mandrel.

Background Art

[0002] In order to produce tubes from coated metal sheet and obtain a multi-wall pipe form, a coating process over the metal sheet is carried out and coated metal sheet is bended by means of aligned rollers in a row. PCT/TR2016/060407 discloses such a pipe forming assembly. Pipe forming assembly contains a mandrel in the longitudinal axis of the bended metal sheet. US2428474 publication discloses such a mandrel used in pipe forming platform. Mandrel has a diameter adjustment part or a drawing part which is engaged to the inner wall of the pipe during the drawing under heavy pressure and a generally wide shoulder part exposed to less pressure and distant from the diameter adjustment part. Mandrel is an integrated one-piece structure or has parts which are adjoined to each other with a main connection element. The specific form of mandrel provide the forming a continous of oil film during the drawing process.

[0003] Engagement of the drawing part of the mandrel to the inner wall of the pipe is

provided by changing the tip position of the mandrel extending along the strip being transformed to a tube in longitudinal direction. This process is done by the means of an adjustment lever which is provided over the pipe forming platform. The drawing part of the mandrel is being moved forward with rotating the adjustment lever by an operator in the axial direction and thus the engagement tip inside the bended pipe is dicovered. A load over the adjustment lever is shifted over the adjustment lever due to the contact between drawing part of the mandrel and pipe form during the engagement and operator using the adjustment lever feel the load as a force feedback and finalize the adjustment process.

Summary of Invention [0004] The object of the invention is adjustment of the engagement distance of the mandrel in an assembly for forming multi-wall pipes made of coated sheet according to a predefined diameter value in a standard manner.

[0005] In order to achieve the above objectives, the invention relates to a mandrel

adjustment assembly for multi-wall pipe made of a coated metal sheet comprising; a bearing positioning an elongated mandrel over a tray by holding; a distance adjustment unit having an adjustment member adjusting a stroke distance of mandrel by changing axial location of bearing; a first support and a second support holding mandrel over a tray such that the mandrel is freely movable between a distal end and an opposite proximal end. Mandrel adjustment assembly, comprises a distance adjustment unit is equipped with a display enabling visual access to a stroke distance set by an adjustment arm and the distance adjustment unit move the mandrel over the tray providing a displacement equal to stroke distance. The display renders the stroke distance visually accessible by representing a dimensional or torque values. Mandrel lies over bended strip formed metal sheet on the tray in the axis of the tube. The stroke position of the mandrel over tray is changing in accordance with the tube diameter to be obtained. After disposing the mandrel on the bearing in accordance with the pipe diameter to be produced from the display by reading the stroke distance or applied torque value mandrel position adjustment is completed. Thus, without any need of the operator defining the spot by feeling a force feedback by hand, adjustment assembly on the supports provide standardized force in each operation and mandrel is moved axially accordingly.

[0006] In a preferred embodiment of the invention, a housing on which the display is

mounted and the holding arm telescopicaly received is secured to the bearing.

Telescopic arrangement allow holding arm to move inside the housing when the stroke position increases or decreases according to a reference point.

[0007] In a preferred embodiment of the invention, the holding arm is vertically positioned at the support edge of tray from a free end of the tray. Thus the stroke of the holding arm and stroke distance are exactly the same and when the stroke is represented by the display stroke distance is fixed.

[0008] In a preferred embodiment of the invention, length of the tray is greater than the length of the mandrel. The mandrel hanged with first and second joints is disposed over the metal stripe and mandrel stays at the interior part of multi-wall pipe during the bending along the tray. [0009] In a preferred embodiment of the invention, the first support and the second support are located at a vicinity of the corresponding edges of the tray. Mandren is hanged to the tray by support from the opposite ends. In a preferred embodiement of the

invention, adjustment member comprises a rotating arm. Rotating arm, for example with the rotation of the bagel type control arm by the operator, provides adjustment of the stroke and thus easy set of the stroke distance of bearing according to tray.

[0010] In a preferred embodiment of the invention, a rotation axis of the adjustment member is diagonal to the stroke axis of mandrel. In this way operator, by controlling the mandrel along the stroke distance, at the same time can adjust the stroke distance.

[001 1 ] In a preferred embodiment of the invention, display comprises a digital monitor.

Digital monitor provides sensitive stroke motion adjustment control.

Brief Description of Drawings

Fig. 1

[0012] [fig. 1 ] is top schematic view of a representative embodiement of a mandrel

adjustment assembly used in made from coated metal sheet for multi-wall pipe production platform.

Description of Embodiments

[0013] In this detailed description, the invention subject is described with reference to

illustrative examples for the better understanding of the present invention without limiting it in any way.

[0014] In [Fig.1 ] Figure 1 , schematic top view of a mandrel adjustment assembly disposed at a pipe forming region (1 ) in multi-wall pipe production is shown. In the pipe forming region (1 ) a rectangular tray (50) is placed longitudinally. From a support edge (52) that a short edge of the tray described a distance adjustment unit (20) outward carries the mandrel (30) as allowing it to progress. In the tray (50) to the opposite edge (54) that is in the opposite direction of support edge (52) and fixed as in a transverse manner as close to the support edge (52) in order a first support (10) and a second support (40) hangs the mandrel (30) over the tray (50). First support (10) bears a front roll (14) which is in close location to a proximal end (32) of mandrelin (30), with two opposite ends with at each en done front bearing (12) as rotatably. On the other hand first support (10) and equal structured second support (40) bears a rear roll (44) which is attached as rotatably between one pair rear bearing (42), that is parallel to mandrel's (30) extension axis, and which supports from the mandrel's (30) one distal end (34). Mandrel (30) has a restricted freedom of movement along the extension route. A distance adjustment unit (20) is provided as giving motion to the mandrel (30) in extension direction as neighbour to the second support (40) close to the support edge (52) of tray (50). Distance adjustment unit (20) comprises a bearing (22) stroking mandrel's (30) extension axis and an adjustment member (26) is fixed in side part of this. A front holding element (21 ) clutches mandrel (30) from its proximal end (34). In this way, when bearing (22) goes forward it moves the mandrel (30) together with it on tray (50) on hanging first support (10) and second support (40). The motion as in the widened view is provided by a holding arm (23) that is side fixed to bearing (22) with a body (27) and that moving inside a housing (25) looking to support edge (52) and which is attached to the support edge (52) from its external end. Holding arm (23) extends parallel to bearing (22) stroke axis. Holding arm (23) is associated as provided the stroke distance (x) measurement by a display (24) attached over housing (25) and having a screen looking upwards. When the adjustment member (26) which is mounted tos ide body (27) as rotatably turned in the rotation of direction (r ) by a gear pair (not shown) it turns the rotation motion to stroke motion of holding arm (23). When adjustment member (26) is rotated holding arm (23) removes the bearing (22), to which it is fixed,as axially from the tray (50) by applying compression force to the support edge (52) , which it supports. In this way front holding element (21 ) pulls the proximal end (34) towards the tray (50) by pulling mandrel (30) over the tray. This motion provides positioning the shape form giving end of mandrel (30) to a location determined before during pipe production. With rotating the adjustment member (26) in opposite direction holding arm (23) brings closer the bearing (22) as axially to the tray (50) by applying pull force to the support edge (52),caught by it. In this situation, mandrel (30) is moved from the opposite edge (54) towards the outside. This motion provides positioning the shape form giving end of mandrel (30) to a location determined before during pipe production.

5] The display (24) comprises a digital monitor (241 ) which from outside accessible as visual, looking to the upwards. The screen which is produced with LCD or similar technology,allows to read the stroke distance (x) of holding arm (23) according to a reference point as milimeter or cantimeter type. Thus, it is provided that the mandrel (30) that is put over the metal sheet strip got in pipe forming region (1 ),took in suitray position to the pipe production that the diameter determined before.Stroke distance (x) being stroke that is obtained by turning the radial motion provided by adjustment member (26) into lineer motion over holding arm (23), is turned into readable numbers readable by display (24). It can be provided that the display (24) reads the stroke distance (x) directly with measuring of motion quantity of holding arm (23), it can also be provided that from a value adjusted before corresponding to rotation angle of adjustment member (26) radial motion.

[0016] Stroke value by display (24) can be measured by a known as measuring distance measuring platform,for example with micrometer. Further it is clear that for torque value measurement by display (24), a load cell inside a housing (25) can be used.

Reference Signs List

[0017]

1 . Pipe forming region

10. First support

12. Front bearing

14. Front roll

20. Distance adjustment unit

21 . Front holding element

22. Bearing

23. Holding arm

24. Display

241 . Digital monitor

25. Housing

26. Adjustment member

27 Body

30. Mandrel

32. Proximal end

34. Distal end

40. Second support

42. Rear bearing

44. Rear roll

50. Tray

52. Support edge 54. Opposite edge x. Stroke distance r. Rotation direction