WO2011101730A1

WO2011101730A1 - Apparatus for the insertion of bends in pipes for fluid of a heat exchanger

Info

Publication number: WO2011101730A1
Application number: PCT/IB2011/000323
Authority: WO
Inventors: Valerio Giordano Riello; Alberto Foroni; Stefano Cenci; Giulio Rosati; Aldo Rossi
Original assignee: Sierra S.P.A.
Priority date: 2010-02-22
Filing date: 2011-02-21
Publication date: 2011-08-25
Also published as: ITMI20100267A1; IT1398306B1

Abstract

An apparatus (1) for the insertion of bends (14) in pipes for fluid of a heat exchanger (10) comprises a loader (20) to contain a plurality of bends (14), guide means (30) to guide the bends (14) from the loading area (24) to the unloading area (25) of the loader (20), a pick-up device (40) arranged at the unloading area (25) of the loader (20) and configured to pick each bend (14) up in succession from the loader (20), gripping means (60) suitable for receiving the bend (14) picked up by the pick-up device (40) and inserting the bend (14) in the pipes for fluid of a heat exchanger, transfer means (50) suitable for transferring the bend (14) picked up by the pick-up device (40) to the gripping means (60).

Description

"Apparatus for the insertion of bends in pipes for fluid of a heat exchanger"

DESCRIPTION

The present invention concerns an apparatus for the insertion of bends in pipes for fluid of a heat exchanger.

A typical heat exchanger comprises a finned pack and one or more circuits of pipes for fluid mounted in the finned pack. Each circuit of pipes comprises a plurality of hairpins made from a pipe bent into a U so as to define two parallel pipes with respective connection ends. In order to create a single circuit for fluid through the hairpins mounted in the finned pack, it is necessary to connect together the hairpins according to a predefined scheme. Such a connection is made through C-union elements, commonly known by the name bends. A bend comprises a C-shaped pipe having two connection ends intended to insert in the corresponding connection ends of the pipes of two hairpins of the heat exchanger.

In the state of the art, the insertion of the bends in the pipes of the hairpins of the heat exchanger is performed manually. An assembly line worker positions the exchanger on a conveyor belt fixing it to the base on the side from which the U-shaped portions of the hairpins project. The conveyor belt carries the exchangers very slowly towards the area where the brazing of the bends takes place. During this journey, the worker manually inserts the bends in the connection ends of the pipes of the hairpins, according to a predetermined scheme. Then, the worker manually upsets the bends to improve and ensure the coupling of the bends with the pipes of the hairpins. At this point, it is possible to position another heat exchanger on the conveyor belt and repeat the operations of inserting and upsetting the bends.

The insertion procedure of the bends described above does however have some drawbacks. Firstly, it should be noted that the assembly procedure takes a long time due to the low speed that the conveyor belt must go in order to allow the worker to insert the bends. Moreover, the separation of the operations of inserting bends and upsetting further lengthens the assembly time. It is also clear that the insertion by a worker can result in assembly errors and/or damage during the insertion of the bend.

It would thus be desirable to be able to perform the operations of inserting the bends in the pipes of the heat exchangers in an automated, quick and reliable manner.

The purpose of the present invention is therefore to provide an apparatus for the insertion of bends in pipes for fluid of a heat exchanger having structural and functional characteristics such as to satisfy the aforementioned requirements and at the same time to avoid the aforementioned drawbacks with reference to the prior art.

Such a purpose is accomplished by an apparatus for the insertion of bends in pipes for fluid of a heat exchanger in accordance with claim 1.

Further characteristics and advantages of the apparatus for the insertion of bends in pipes for fluid of a heat exchanger according to the present invention will become clear from the following description of a preferred embodiment, given for indicating and not limiting purposes, with reference to the attached figures, in which:

- figure 1 shows a perspective view of an apparatus for the insertion of bends in pipes for fluid of a heat exchanger in accordance with the present invention,

- figures 2 to 6 show perspective views of the apparatus of figure 1 in different operative configurations,

- figure 7 shows a plan view from above of the apparatus of figure 1 ,

- figure 8 shows a heat exchanger,

- figures 9 to 17 show side partial section views of the apparatus of figure 1 in successive operative configurations.

With reference to the attached figures, reference numeral 1 indicates an apparatus for the insertion of bends in pipes of a heat exchanger, for example the heat exchanger 10 (figure 8). The heat exchanger 10 comprises a plurality of fins 11 arranged parallel to one another and spaced apart so as to form a finned pack 12. Each fin 1 1 has a plurality of through holes with axis perpendicular to the plane of the fin 11 itself. Each hole of a fin is aligned with corresponding holes of the fins parallel to it so as to define a plurality of aligned passages for the mounting of one or more circuits of pipes for fluid. Each circuit of pipes comprises a plurality of hairpins 13, each comprising two parallel pipes and a U-shaped connection portion of the two pipes and made from a pipe bent in a U at its middle area. Each hairpin 13 extends through the finned pack 12 from a first side 12a to a second side 12b, opposite the first side 12a. In the example, the U-shaped connection portion is positioned at the side 12a of the finned pack 12 whereas, on the opposite side 12b, the connection ends 13a,13b of the two pipes making up each hairpin 13 project.

In order to create a single circuit for fluid through the hairpins 13 mounted in the finned pack 12 of the heat exchanger 10, it is necessary to connect together the hairpins 13 according to a predetermined scheme.

Such a connection is made through C-union elements 14, commonly known by the name bends.

A bend 14 comprises a C-shaped pipe having two connection ends 14a, 14b intended to insert in the corresponding connection ends of the pipes of two hairpins 13 of the heat exchanger 10.

The bend 14 may comprise a copper ring fixed around the two connection ends 14a, 14b and intended to be used for braze- welding the bend 14 to the connection end of the pipes of the heat exchanger 10.

The insertion of the bends 14 in the pipes for fluid of the heat exchanger 10 is carried out through the apparatus 1 in accordance with the present invention.

The apparatus 1 comprises a loader 20 suitable for containing a plurality of bends 14.

The loader 20 is supported by a support structure 2, in the example a support plate.

The support plate 2 has a tool-change connector 3 fixed to it, in the example a female connector, suitable for connecting with a matching connector 4, in the example a male connector, carried by a moving device to move the apparatus 1.

The connector 3, fixed to the support plate 2, allows a moving device to move the apparatus 1 within a work area. For example, the apparatus 1 can be moved between an operative area intended for the insertion of bends and a loading and unloading storage area where the apparatus 1 can be put down and replaced with another apparatus 1. In this way, it is possible to optimise the assembly operations of the heat exchangers by quickly replacing an apparatus empty of bends with another already loaded and/or with a different type of bends.

Figure 2 shows a portion of a shaft 5 of the moving device, the end of which 5a is fixed to the male connector 4 and, through the male-female coupling, to the support plate 2 of the apparatus 1.

In accordance with an embodiment, the loader 20 comprises a tubular element 21 extending along a direction Z-Z and having two open ends 22,23 that respectively define a loading area 24 and an unloading area 25.

In the example of the attached figures, the tubular element 21 has a rectangular section and is defined by four walls 21a,2b,21c,21d extending along the direction Z-Z between the upper end 22 and the lower end 23.

Guide means 30 are arranged to guide the bends 14, inside the loader 20, from the loading area 24 to the unloading area 25, along the direction Z-Z.

In accordance with an embodiment, the guide means 30 are configured so that the bends 14 are stacked on top of one another, along the direction Z-Z, in the loader 20.

In accordance with an embodiment, the guide means 30 comprise a guide extending along the direction Z-Z and fixed onto the inner side of one of the walls of the tubular element 21, in the example on the inner side of the wall 21a. The guide 30 extends from the loading area 24 to the unloading area 25 of the loader 20.

Advantageously, the guide 30 is configured so as to allow the bends 14 to slide by gravity along the direction Z-Z and prevent them from coming out from the guide 30. In particular, the guide 30 has a section with a mushroom-shaped profile with stem 31 fixed to the wall 21a and projecting perpendicular from the wall 21a and cap 32. Such a configuration makes it possible to improve the sliding of the bends along the guide 30 and, in particular, to hold the rings of the bends 14 between the wall 21a of the loader 20 and the base of the cap 32 in the case of bends equipped with a copper ring around the two connection ends 14a, 14b.

A pick-up device 40 is arranged at the unloading area 25 of the loader 20 to pick each bend 14 up in succession.

In accordance with an embodiment, the pick-up device 40 comprises a locking member 41 suitable for locking the penultimate bend present in the loader 20 so as to stop the descent, towards the unloading area 25, thereof and of the bends on top of it. The locking member 41 has a particular application in the presence of bends 14 equipped with a copper ring around the two connection ends 14a, 14b.

In order to lock the penultimate bend, the stopping member 41 is mobile between a rest position (figure 9), in which it is disengaged from the penultimate bend, and an operative position (figure 10), in which it engages the penultimate bend to stop it from descending towards the unloading area 25. In order to allow the stopping member 41 to interact with the bends 14 present in the loader 20, the loader 20 has a through opening 26 formed in the wall 21a of the tubular element 21 to which the guide 30 is fixed.

In accordance with an embodiment, the stopping member 41 is configured like the guide 30. In this way, when it is in rest position, the stopping member 41 represents a portion of the guide 30 whereas, when it is in operative position, it acts as a thrusting element. Basically, when the mobile stopping member 41 is present, the guide 30 comprises two elements joined by the stopping member 41 when it is in rest position.

The movement of the stopping member 41 is made through actuation means 42, for example pneumatic actuation means, supported by a support plate 6 fixed to the support plate 2 of the loader 20. The pneumatic actuation means 42 comprise a cylinder 43 and a piston 44 connected to the stopping member 41 and thus rigidly joined to it.

The locking of the penultimate bend present in the loader 20 is made by actuating the pneumatic actuation means 42 so as to move the stopping member 41 into the operative position in which it presses the penultimate bend against the wall 21c of the tubular element 21, opposite the wall 21a to which the guide 30 is fixed. In this way, the last bend is decoupled from the penultimate bend and is free to come out from the loader 20 in the unloading area 25.

In accordance with an embodiment, the apparatus 1 comprises a sensor 33 arranged at the unloading area 25 and suitable for detecting the presence of a bend under the penultimate bend. Thanks to the sensor 33, it is possible to determine the end of the bends contained in the loader 20 and to determine possible malfunctions of the apparatus 1.

The apparatus 1 also comprises gripping means 60 suitable for receiving the bend picked up by the pick-up device 40 and inserting the bend in the pipes for fluid of a heat exchanger and transfer means 50 suitable for receiving the bend picked up from the loader 20 and transferring this bend to the gripping means 60.

The transfer means 50 comprise a base plate 51 that defines a seat 52 suitable for receiving and supporting the bend picked up from the loader 20 and a pushing trolley 53 suitable for transferring the bend picked up to the gripping means 60.

Thanks to the sensor 33 it is thus possible to check that the last bend has fallen correctly into the seat 52 when the pushing trolley 53 is in the first position.

The gripping means 60 comprise a housing 61 having a receiving seat 62 suitable for receiving and housing a bend 14.

The pushing trolley 53 is mobile between a first position (figure 11) and a second position (figure 9 and 12-17) in which it respectively allows and prevents the last bend 14 from falling from the loader 20 to the seat 52.

It should be noted that, when the seat 52 houses a bend (figure 11), the pushing trolley 53 can move from the first position (figure 11) to the second position (figure 12) to push the bend present in the seat 52 inside the receiving seat 62 of the housing 61 of the gripping means 60.

The pushing trolley 53 is actuated through actuation means 54, for example pneumatic actuation means, supported by the support plate 6. The pneumatic actuation means 54 comprise a cylinder 55 and a piston 56 connected to the pushing trolley 53 and thus forming a unit with it.

In accordance with an embodiment, the cylinder 55 comprises a linear guide 57 to guide the movement of the piston 56 and of the pushing trolley 53.

When the actuation means 42 move the stopping member 41 into operative position to lock the penultimate bend, the actuation means 54 move the pushing trolley 53 from the first position to the second position to prevent the last bend from descending from the loader 20 to the seat 52 (figure 9). In this condition, the last bend rests on top of the pushing trolley 53 and a movement of the pushing trolley 53 towards the first position (figure 1 1) allows the bend picked up by the loader 20 to descend into the seat 52. A further movement of the pushing trolley 53 from the first to the second position (figure 12) causes the bend to fall from the seat 52 inside the receiving seat 62 of the housing 61 of the gripping means 60.

The gripping means 60 comprise holding means 63 to hold the bend inside the receiving seat 62 of the housing 61.

In accordance with a preferred embodiment, the holding means 63 comprise a suction pad 64 arranged inside the receiving seat 62 of the housing 61.

Advantageously, the suction pad 64 has a hole 65 connected to a vacuum generating device (not shown in the figures), for example a Venturi effect device, which makes it possible to activate the suction pad 64 and lock the bend in position inside the receiving seat 62.

In order to allow the assembly of the bend held in the housing 61 with the pipes of a heat exchanger, the bend 14 must firstly be positioned so that the axes of its connection ends 14a, 14b are parallel to the axes of the ends 13 a, 13b of the pipes of the hairpins 13 of the heat exchanger 10, in the example shown in the figures with the axes parallel to the vertical direction Z-Z.

Through a control and viewing system by image acquisition, the apparatus 1 can be positioned so that the axes of the connection ends 14a, 14b of the bend 14 to be assembled are arranged aligned with the axes of the ends 13a, 13b of the pipes 13 of the heat exchanger 10.

In order to arrange the bend 14 with the axes of its connection ends 14a, 14b parallel to the direction Z-Z, it is necessary to rotate the housing 61 in which the bend is held.

For this purpose, the apparatus 1 comprises actuation means 70 connected to the housing 61 to rotate the housing 61 around a rotation axis A- A. The housing 61 is mounted in rotation around a rotation pin 67 extending along the rotation axis A-A.

In accordance with an embodiment, the actuation means 70 are pneumatic actuation means and comprise a cylinder 71 and a piston 72.

The piston 72 has an end portion 72a connected to a housing support 73 to support the housing 61 as it rotates. The piston 72 is mobile along the direction Z-Z, in the insertion direction A and in the opposite direction B.

The housing 61 has two parallel arms 74,75 equipped with holes in which the rotation pin 67 is inserted. The housing support 73 has a through hole aligned with the holes of the arms 74,75 for the rotation pin 67 to pass through.

The actuation of the rotation of the housing 61 around the rotation pin 67 is carried out through a cam-cam follower coupling system.

In particular, the housing 61 comprises two cam-follower elements 80,81 projecting outwards and on opposite sides from the housing 61 itself and arranged parallel to the rotation pin 67. The cam-follower elements 80,81 are intended to engage corresponding cam paths 82,83 formed in respective walls 84,85 arranged at the side of the housing 61 and fixedly connected to the support plate 6.

The housing 61 is thus mobile in rotation between a receiving position (figures 9-12 and figure 17), in which it is arranged to receive the bend, and an insertion position (figures 13-16), in which it is arranged to assemble the bend held in it with the pipes of the heat exchanger.

As can be seen from the figures, for example from figure 12, in the receiving position, the cam-follower elements 80,81 are engaged with the corresponding cam paths 82,83.

Following the actuation of the pneumatic means 70, the piston 72 and the housing support 73 move along the direction Z-Z in the insertion direction A. In a first section of stroke of the piston 72, the movement of the housing support 73 along the direction Z-Z is transformed, by the cam-follower elements 80,81 engaged in the cam paths 82,83, into a rotation of the housing 61 around the rotation pin 67 (figure 13)

When the cam-follower elements 80,81 are disengaged from the cam paths 82,83, the rotation off the housing 61 ends and the housing 61 is in insertion position.

However, it should be noted that, since the cam-follower elements 80,81 are disengaged from the cam paths 82,83, the housing 61 would still have the rotation pin 67 as the only constraint and therefore it would be free to rotate around the rotation pin 67. In order to keep the housing 61 in insertion position and avoid undesired rotations of the housing 61, the gripping means 60 comprise hooking means 90 carried by the housing 61 and rotating as a unit with it and suitable for engaging matching hooking means 91 so as to make a shape coupling and prevent the rotation of the housing 61 around the rotation pin 67 when the housing 61 is in insertion position (figure 14).

In accordance with an embodiment, the hooking means 90 comprise an appendage 92 projecting from the housing 61 and having a recess 93. The matching hooking means 91 comprise an appendage 94 projecting from a support plate 95 and having a hooking tooth 96 intended to engage the recess 93.

In accordance with an embodiment, the matching hooking means 91 are mounted in a mobile manner along the direction Z-Z and are configured to make a oneway engagement with the hooking means 90 along the direction Z-Z.

The engagement of the hooking means 90,91 is made through a relative movement thereof along the direction Z-Z according to a first direction, corresponding to the insertion direction A, whereas the disengagement thereof is carried out through a relative movement along the direction Z-Z according to a second direction B, opposite the first direction A.

For this purpose, the support plate 95, which carries the hooking means 91, is mounted so as to be able to slide along a guide element 89 extending along the direction Z-Z, whereas the hooking means 90 are mobile since they are fixedly connected to the housing 61.

More specifically, at the end of the rotation of the housing 61 (figure 13), the hooking means 90 are in a position such as to be able to make a shape coupling with the matching hooking means 91. At this point, a second section of stroke of the piston 72 allows the engagement of the hooking means 90,91 to be carried out so as to lock the housing 61 in insertion position (figure 14).

For this purpose, the support plate 95 is coupled with the housing support 73 through elastic means 76 preloaded to push the support plate 95, and therefore the matching hooking means 91, along the direction Z-Z according to the direction B opposite the insertion direction A. In order to allow correct functionality of the elastic means 76, they are guided by a guide element 97 fixed to the housing support 73 and projecting from it along the direction Z-Z.

When the piston 72 moves along the direction Z-Z in the insertion direction A, the housing support 73 and the hooking means 90 also move along said direction in the insertion direction A. The hooking of the hooking means 90,91 is secure and stable thanks to the push that the elastic means 76 exert on them along the direction Z-Z and in opposite directions.

The last section of stroke of the piston 72 (figure 15), allows the housing 61 to be moved along the direction Z-Z in the insertion direction A to take the housing 61 to the connection ends of the pipes 13 of the heat exchanger 10 and to go ahead with the insertion of the connection ends 14a, 14b of the bend 14 in the predetermined connection ends of the pipes 13 of the heat exchanger 10. ,

It is worth noting that the movement of the housing 61, and therefore of the housing support 73, along the direction Z-Z is guided by guide means 68. In accordance with an embodiment, the guide means 68 comprise a ball bearing guide fixedly connected to the support plate 6 and extending along the direction Z-Z.

After the bend 14 has been inserted in the pipes 13 of the heat exchanger 10, the Venturi effect device is switched off and air is blown through the hole 65 of the suction pad 64 to facilitate the separation of the suction pad 64 from the bend 14 and ensure that the bend 14 remains inserted in the pipes 13 of the heat exchanger 10.

Thereafter, the actuation means 70 can be actuated to move the housing 61 along the direction Z-Z in the opposite direction B to the insertion direction A. The housing 61 then goes back into receiving position and the apparatus 1 is ready to proceed to insert another bend 14 (figures 16 and 17).

The unhooking of the hooking means 90,91 is carried out thanks to the presence of an abutment stem 98 fixed to the plate 95 and projecting from it along the direction Z-Z in the opposite direction B to the insertion direction A.

The length of the abutment stem 98 is selected so that, as soon as the cam- follower elements 80,81 of the housing 61 engage the cam paths 82,83, the free end 98a thereof engages the support plate 2 so as to stop the movement of the support plate 95. On the other hand, the housing support 73 is free to continue in its movement along the direction Z-Z so that the engagement means 90 carried by it can disengage from the matching engagement means 91.

In accordance with an embodiment, the length of the abutment stem 98 is adjustable. For this purpose, the free end 98a can be provided with an adjustment screw 99 the head of which, projecting from the stem 98, is intended to abut against the lower face of the support plate 2.

As can be appreciated from what has been described, the apparatus according to the present invention allows the aforementioned drawbacks with reference to the prior art to be overcome. In particular, the apparatus 1 of the present invention allows the operations of inserting the bends in the pipes of the heat exchangers to be carried out in an automated, quick and reliable manner.

Of course, a man skilled in the art, in order to satisfy contingent and specific requirements, can bring numerous modifications and variants to the apparatus according to the invention described above, all of which are in any case covered by the scope of protection of the invention as defined by the following claims.

Claims

1. Apparatus (1) for the insertion of bends (14) in pipes for fluid (13) of a heat exchanger (10), said apparatus comprising:

- a loader (20) to contain a plurality of bends (14), said loader having a loading area (24) and an unloading area (25),

- guide means (30) to guide the bends (14) from the loading area (24) to the unloading area (25),

- a pick-up device (40) arranged at the unloading area (25) of the loader (20) and configured to pick each bend (14) up in succession from the loader (20),

- gripping means (60) suitable for receiving the bend (14) picked up by the pick-up device (40) and inserting the bend (14) in the pipes for fluid of a heat exchanger,

- transfer means (50) suitable for transferring the bend (14) picked up by the pick-up device (40) to the gripping means (60).

2. Apparatus (1) according to claim 1, wherein said loader (20) comprises a tubular element (21) extending along a direction (Z-Z) and having two open ends (22, 23) that respectively define said loading area (24) and said unloading area (25).

3. Apparatus (1) according to claim 2, wherein said guide means (30) comprise a guide extending along said direction (Z-Z) and configured so as to allow the bends (14) to slide by gravity along said direction (Z-Z).

4. Apparatus (1) according to any one of claims 1 to 3, wherein said pick-up device (40) comprises a locking member (41) suitable for locking the penultimate bend present in the loader (20) so as to stop it and the bends on top of it from descending towards the unloading area (25), said stopping member (41) being mobile between a rest position, in which it is disengaged from the penultimate bend, and an operative position, in which it engages the penultimate bend to stop its descent towards the unloading area

5. Apparatus (1) according to any one of claims 1 to 4, wherein said transfer means (50) comprise a base plate (51) that defines a seat (52) suitable for receiving and supporting the bend picked up from the loader (20) and a pushing trolley (53) suitable for transferring the bend picked up to the gripping means (60).

6. Apparatus (1) according to claim 5, wherein said pushing trolley (53) is mobile between a first position and a second position in which, respectively, it allows and prevents the descent of the last bend (14) from the loader (20) to the seat (52).

7. Apparatus (1) according to any one of claims 1 to 6, wherein said gripping means (60) comprise a housing (61) having a receiving seat (62) suitable for receiving and housing a bend (14) and holding means (63) for holding the bend inside the receiving seat (62) of the housing (61).

8. Apparatus (1) according to claim 7, wherein said holding means (63) comprise a suction pad (64) arranged inside the receiving seat (62) of the housing (61).

9. Apparatus (1) according to claim 7 or 8, wherein said housing (61) is mounted in rotation around a rotation pin (67) extending along a rotation axis (A-A), said apparatus (1) comprising actuation means (70) connected to the housing (61) to rotate the housing (61) around said rotation axis (A-A) between a receiving position, in which it is set up to receive the bend, and an insertion position, in which it is set up to assemble the bend held in it to the pipes of the heat exchanger.

10. Apparatus (1) according to claim 9, wherein the actuation of the rotation of the housing (61) around the rotation pin (67) is carried out through a cam-cam follower coupling system comprising two cam- follower elements (80, 81) projecting outwards and on opposite sides from the housing (61) and intended to engage corresponding cam paths (82, 83) arranged at the side of the housing (61).

11. Apparatus (1) according to any one of claims 7 to 10, wherein said gripping means (60) comprise hooking means (90) carried by the housing (61) and rotating together with it and suitable for engaging matching hooking means (91) so as to perform a shape coupling and prevent the rotation of the housing (61) around the rotation pin (67) when the housing (61) is in insertion position.

12. Apparatus (1) according to claim 11, wherein said matching hooking means (91) are mounted mobile along -a direction (Z-Z) and are configured to make a one-way engagement with the hooking means (90) along a direction (Z-Z), said matching hooking means (91) being coupled with said housing (61) through elastic means (76) preloaded to push said matching hooking means (91) along said direction (Z-Z) according to a direction (B) opposite to the insertion direction (A).