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Patent Searching and Data


Title:
METHOD AND APPARATUS FOR MAKING A T-BRANCH COLLAR IN A PIPE
Document Type and Number:
WIPO Patent Application WO/2022/152964
Kind Code:
A1
Abstract:
The invention relates to a method and apparatus for making a T-branch collar in a pipe by bending the rims of the pipe (17) hole into a hole-surrounding collar (16). The forming die (3) of a collaring device is moved radially with respect to the pipe, outwards from inside the pipe to shape the collar. On both sides of the collar (16) to be formed, the pipe (17) is pressed between the inner support means (6) and the outer die (10) by pushing the support means (6) towards the outer die (10).

Inventors:
LARIKKA LEO (FI)
Application Number:
PCT/FI2021/050898
Publication Date:
July 21, 2022
Filing Date:
December 20, 2021
Export Citation:
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Assignee:
LARIKKA LEO (FI)
International Classes:
B21D19/08; B21C37/29
Attorney, Agent or Firm:
LEITZINGER OY (FI)
Download PDF:
Claims:
6

Claims

1. A method for making a T-branch collar in a pipe by bending the rims of the pipe (17) hole into a hole-surrounding collar (16), in which method the forming die (3) of a collaring device is moved radially with respect to the pipe, outwards from inside the pipe to shape the collar, characterised in that on both sides of the collar (16) to be formed, the pipe (17) is pressed between the inner support means (6) and the outer die (10) by pushing the support means (6) towards the outer die (10) on the same side of the pipe as the collar to be formed.

2. A method according to claim 1, characterised in that the compressive force between the support means (6) and the outer die (10) is adjusted to be so high that the compressive force prevents the pipe material pressed between the support means and the outer die from moving towards the collar (16) during the shaping of the collar.

3. A method according to claim 1 or 2, characterised in that the forming die (3) is moved by pushing the collaring wedge (2) between the forming die (3) and the body (1) of the collaring device in such a way that the pushing point (12) of the collaring wedge (2) approaches the body (1) of the collaring device.

4. An apparatus for making a T-branch collar in a pipe by bending the rims of the pipe (17) hole into a hole-surrounding collar (16), the apparatus comprising a body (1) which has a cylindrical outer surface and which is insertable inside a pipe (17) to be collared, a forming die (3) with an outer diameter which is essentially equal to the desired inner diameter of the collar (16), a space (5) in the body (1) which is dimensioned to receive the forming die (3), whereupon the forming die (3) is movable under guidance of the said space (5), an outer die (10) which has a cylindrical inner surface and which can be placed around the pipe (17) to be collared, the hole (25) of the forming die (3) in the outer die (10) as well as actuators (2) connectable to a power unit (14) for moving the forming die (3) outwards from the space (5) of the body, characterised in that on both sides of the space (5) in the forming die are support means (6) which are located in the cuts or recesses (6a) in the cylindrical surface of the body (1), that the support means 7

(6) have a cylindrical surface complementing the cylindrical outer surface of the body (1), and that the support means (6) are arranged to be lifted by means of another power unit (15, 7, 8) outwards from the body (1), towards the outer die (10), and to thus press the pipe (17) between the support means (6) and the inner surface of the outer die (10) on both sides of the hole (25) in the forming die.

5. An apparatus according to claim 4, characterised in that in the axial bores (7a) of the body (1) are fitted lifting bars (7), the wedge surfaces (9) of which are arranged to lift the support means (6) outwards from the body when the lifting bars

(7) are moved in the axial direction of the body.

6. An apparatus according to claim 5, characterised in that between the wedge surfaces (9) of the lifting bars (7) and the support means (6) are lifting pins (8), which are located in the bores (8a) of the body (1) which are perpendicular to the said axial bores (7a).

7. An apparatus according to claim 5 or 6, characterised in that two parallel lifting bars (7) extend beyond the body (1) by a distance which is longer than the length of the wedge surfaces (9) of the lifting bars, and that the outer ends of the lifting bars (7) are joined by a flange (13) to which the power unit (15) moving the lifting bars (7) can be connected.

8. An apparatus according to claim 6, characterised in that the lifting pins (8) are closer to the ends of the support means (6) which point towards each other and at the same time towards the space (5) in the forming die.

9. An apparatus according to claim 4, characterised in that the actuators to be connected to the power unit (14) include a collaring wedge (2), which has been received in the axial groove (4) of the body (1) and the wedge surface (2a) of which is located in the space (5) in the forming die, whereupon the wedge surface (2a) of the collaring wedge (2) is adapted to push the forming die (3) outwards from the body (1) when the collaring wedge (2) is moved in the axial direction of the body. 8

10. An apparatus according to claim 9, characterised in that the pushing end (12) of the collaring wedge (2), to which the power unit (14) is connected, is arranged to be pushed by means of the power unit (14) towards the body (1) during collaring.

Description:
Method and apparatus for making a T-branch collar in a pipe

The invention relates to a method for making a T-branch collar in a pipe by bending the rims of the pipe hole into a hole-surrounding collar, in which method the forming die of a collaring device is moved radially with respect to the pipe, outwards from inside the pipe to shape the collar.

The invention also relates to an apparatus for making a T-branch collar in a pipe by bending the rims of the pipe hole into a hole-surrounding collar, the apparatus comprising a body which has a cylindrical outer surface and which is insertable inside a pipe to be collared, a forming die with an outer diameter which is essentially equal to the desired inner diameter of the collar, a space in the body which is dimensioned to receive the forming die, whereupon the forming die is movable under guidance of the said space, an outer die which has a cylindrical inner surface and which can be placed around the pipe to be collared, as well as actuators connectable to a power unit for moving the forming die outwards from the space in the body.

A method and apparatus of this type are known from the publication EP 1332807 Bl. When a collar for a T-branch joint is made in a pipe by stretching the material, the elasticity of the pipe and the internal stresses created in the material have an adverse effect on the shape and dimensions of the collar formed and the standard pipe. The collar formed in this known solution is calibrated to render it as round as possible. From the publication JP H0747430 A is also known the forming of a T- branch collar by means of a forming die.

A problem that remains are dimensional errors resulting from deformations in the standard pipe. On both sides of the collar to be formed, the pipe material tends to recede towards the collar (arrow A in Fig. 2A), which shortens the length of the pipe on the collar side. In addition, the pipe material buckles inwards on the pipe next to the base of the collar due to the beam effect (arrow B in Fig. 2A).

From the publication JP 2010094725 A is known making a hole in a pipe by punching. The pipe is supported from the inside by means of a two-part inner die around the hole and from the inner side opposite to the hole, thereby preventing the pipe from being flattened due to the punching force. The die part supporting the pipe around the hole is provided with a punch hole which receives the punch and the piece to be punched off from the pipe hole. The aim is to provide a hole true to size which is achieved when the edges of the punch hole of the die part are pressed against the inner surface of the pipe. The outer die of the apparatus, by which the pipe is supported, is located on the opposite side of the pipe with respect to the hole to be formed. In making the hole, the above-mentioned problem relating to making a T-branch collar does not exist, nor is a T-branch collar being made.

The object of the present invention is to provide a method and an apparatus for solving the above-mentioned problem. This object is achieved by the method according to the accompanying claim 1 and the apparatus according to claim 4. Preferred embodiments of the invention are disclosed in the dependent claims.

The invention is described in the following by means of an exemplified embodiment, with reference to the accompanying drawings, in which:

Figure 1 shows a diagonal top view of the apparatus according to the invention without the outer die and the forming die,

Figure 1A shows separately the lifting bar comprised in the apparatus according to claim 1 as a side view and on a larger scale,

Figure 2 shows a side view of the apparatus according to Fig. 1 with the forming die 3,

Figure 2A shows a side view of a pipe provided with a T-branch collar,

Figure 3 shows a top view of the apparatus according to Fig. 1,

Figure 4 shows a section of Fig. 3 along line IV-IV on a larger scale,

Figure 5 shows a diagonal top view of the outer die,

Figure 6 shows a side view of the body of the apparatus, Figure 7 shows a top view of the body of the apparatus,

Figure 8 shows a section of Fig. 7 along line VIII-VIII, and

Figure 9 shows a diagonal top view of the body of the apparatus.

The apparatus comprises a body 1 with a cylindrical outer surface. The diameter of the cylinder corresponds to the inner diameter of the pipe to be collared with a sliding fit, which means that the body 1 can be inserted in the pipe 17 to be collared. A mainly radial body space 5 passes through the cylindrical surface of the body 1, the space receiving the forming die 3, the outer diameter of which mainly corresponds to the desired inner diameter of the collar 16. The space 5 in the body is dimensioned so that the forming die 3 is movable under guidance of the space 5. The outer die 10 (Fig. 5) has a cylindrical space 20 in which the body 1 and its support means 6 fit. The inner surface 21 of the outer die 10 is thus cylindrical and the diameter of the cylinder corresponds to the outer diameter of the pipe 17 when the halves 22 and 23 of the outer die 10 are closed against each other. The half 22 below the parting line 24 of the outer die is attached to the lower body (not shown) of the apparatus. The upper half 23 has a hole 25 perpendicular to the longitudinal axis of the cylindrical space 20, in which the forming die 3 is able to move up and down. The upper half 23 has threaded holes 26 with which the threaded bars of the lifting and lowering device (not shown) engage. The outer die 10 can be placed around the pipe 17 to be collared by first placing the body 1 with its pipe 17 in the groove in the lower part 22 of the outer die 10 and by then lowering the upper part 23 down to close the outer die 10. The end of the outer die 10 may rest against the body flange 11.

To the power unit 14 (Fig. 1) are connected actuators 2 for moving the forming die 3 outwards from the space 5 in the body. In the embodiment shown, the actuators to be connected to the power unit 14 include a collaring wedge 2, which has been received in the axial groove 4 of the body 1. The wedge surface 2a of the collaring wedge 2 is located in the space 5 in the forming die and the base of the forming die 3 is in contact with the wedge surface 2a of the collaring wedge 2. The wedge surface 2a of the collaring wedge 2 then pushes the forming die 3 outwards from the body 1 when the collaring wedge 2 is moved in the axial direction of the body. Alternatively, the actuators can be implemented by means of a rotatable eccentric or a low hydraulic cylinder located at the bottom of the space 5. In the embodiment shown, the pushing end 12 of the collaring wedge 2, to which the power unit 14 is connected, is arranged to be pushed by means of the power unit 14 towards the body 1 during collaring.

On both sides of the space 5 in the forming die are support means 6 which are located in the cuts or recesses 6a in the cylindrical surface of the body 1. The support means 6 have a cylindrical surface complementing the cylindrical outer surface of the body 1. The support means 6 are arranged to be lifted by means of another power unit 15, 7, 8 outwards from the body 1, towards the outer die 10.

In the embodiment shown, the other power units 15, 7, 8 are made as follows. In the axial bores 7a of the body 1 are fitted lifting bars 7, the wedge surfaces 9 of which are arranged to lift the support means 6 outwards from the body when the lifting bars 7 are moved in the axial direction of the body by a power unit 15. Between the wedge surfaces 9 of the lifting bars 7 and the support means 6 are lifting pins 8, which are located in the bores 8a of the body 1 which are perpendicular to the said axial bores 7a.

In the embodiment shown, two parallel lifting bars 7 extend beyond the body 1 by a distance which is longer than the length of the wedge surfaces 9 of the lifting bars. The outer ends of the lifting bars 7 are joined by a flange 13 to which the power unit 15 moving the lifting bars 7 can be connected.

The power units 14 and 15 may be hydraulic cylinders which are on the same side of the body 1 and act in the same direction, that is, towards the body 1 during collaring. The body 1 is attached to the same external standard body (not shown) with the power units 14 and 15 by means of a body flange 11 attached to the body.

The lifting pins 8 are preferably closer to the ends of the support means 6 which point towards each other and at the same time towards the space 5 in the forming die 3. The compressive force of the support means 6 then increases towards the base of the collar 16, which minimizes deformations. The apparatus described above can be used in the method according to the invention in such a way that the forming die 3 is moved by pushing the collaring wedge 2 between the forming die 3 and the body 1 of the collaring device. When the pushing point 12 of the collaring wedge 2 approaches the body 1 of the collaring device, the wedge surface 2a pushes the forming die 3 through the starting hole in the pipe 17, whereupon the rims of the hole stretch, bend and form into a collar 16 surrounding the hole. The shape and orientation of the collar corresponds to the shape and orientation of the protruding forming die.

On both sides of the collar 16 to be formed, the pipe 17 is pressed between the inner support means 6 and the outer die 10 by pushing the support means 6 towards the outer die 10. This prevents the pipe 17 wall from buckling inwards close to the base of the collar in the direction of arrow B shown in Fig. 2A.

It is preferable to adjust the compressive force between the support means 6 and the outer die 10 to be such that it prevents the pipe material pressed between the support means and the outer die from moving towards the collar 16 during the shaping of the collar. This prevents the length of the pipe from shortening on the collar side (Fig. 2A, arrow A).