Welding machine

Abstract

A welding machine comprising a base that supports the alignment and fastening device; the alignment and fastening device has a guide means, a first clamping unit and a second clamping unit which engage, respectively, a first tubular element and a second tubular element to be joined by welding; at least one of the first clamping unit and the second clamping unit can move from a far position to a near welding position relative to each other; the base is associated with a heating device for welding the first and second tubular elements; the alignment and fastening device is an automated component and is mechanically connected to / disconnected from the base; the alignment and fastening device is switched from a first operative configuration in which the alignment and fastening device is interconnected to the welding machine to a second operative configuration in which the alignment and fastening device is used as a separate device.

Description

Technical Field

[0001] The invention relates to a welding machine, in particular for melt pocket welding. Background Art

[0002] As is well known, fusion welders are tools used to join pipes and fittings made of thermoplastic materials such as polypropylene (PP) and high-density polyethylene (HDPE) using a fusion welding process.

[0003] This type of welding is commonly used to install pipe fittings and pipelines where a strong and durable joining of tubular elements is required.

[0004] These machines are adapted to heat the welding surfaces of the tube and fittings to a specific temperature; once the required temperature has been reached, the tubular elements are brought together and melted (usually using a device to ensure coaxiality) and then left to cool.

[0005] Fusion welders vary in size and functionality, but generally two main types can be distinguished: stationary welders, often called "bench welders", and so-called "portable welders".

[0006] Bench welders are generally used when it is necessary to weld sections of prefabricated equipment for subsequent installation on site.

[0007] The machines of the prior art have a solid base on which are present the elements facilitating the welding process, such as supports for the heating elements, depth stops for the heating and welding phases, supports for the elements to be welded, and so on.

[0008] On the other hand, portable welding machines are used when field welding is required under particularly difficult conditions, such as welding on ceilings, welding near edges and / or walls, welding near other already installed pipes, and in all conditions where a benchtop welding machine cannot be used.

[0009] WO2008092810A1 discloses a trailer for carrying a welding unit for butt welding pipe sections.

[0010] EP 1 700 685 A2 discloses a portable welding device for plastic pipes and pipe fittings of the socket welding type.

[0011] In the prior art, there is no welding machine that can meet all of the above requirements at the same time; in practice, two different products must be used according to specific needs. Summary of the invention

[0012] An object of the present invention is to provide a welding machine that overcomes the limitations of prior art machines.

[0013] Within the scope of this aim, an object of the invention is to provide a welding machine which satisfactorily combines the advantages of using a table welding machine with the advantages of using a portable welding machine.

[0014] Another object of the present invention is a welding machine that achieves the above results in a practical and relatively inexpensive manner.

[0015] Another object of the invention is to provide a welding machine which, thanks to its particular design features, ensures reliability and safety in use.

[0016] These objects and others that will emerge better hereinafter are achieved by a welding machine as claimed in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Further features and advantages will hereinafter become more apparent from the description of a preferred but non-exclusive embodiment of a welding machine according to the invention illustrated by way of non-limiting example in the accompanying drawings, in which:

[0018] Figure 1 is a perspective view of a welding machine according to the present invention;

[0019] Figure 2 It is a three-dimensional diagram of parts of the machine;

[0020] Figure 3 is a side view of a portion of a machine illustrated during use;

[0021] Figure 4 is another side view illustrating a portion of the machine during use;

[0022] Figure 5 It is a cross-sectional view of a machine component;

[0023] Figure 6 is a cutaway side view of a portion of the machine illustrated in an initial operating configuration;

[0024] Figure 7 is a cut-away side view of a portion of the machine illustrated in a second operating configuration;

[0025] Figure 8 It is a perspective view of the machine alignment and fastening device;

[0026] Fig. 9 It is a three-dimensional diagram of the heating device of the machine. DETAILED DESCRIPTION

[0027] With reference to the attached drawings, a welding machine according to the invention, generally indicated by the reference numeral 1 , comprises a base 2 supporting an alignment and tightening device 20 .

[0028] The fastening device 20 comprises a guiding means comprising an elongated body 21 supporting the first clamping unit 40 and the second clamping unit 50 .

[0029] As exemplified, the first clamping unit 40 engages a first tubular element 100, such as an elbow fitting.

[0030] The second clamping unit 50 engages a second tubular element 200, such as a pipe to be joined to the elbow fitting by welding.

[0031] Advantageously, the machine 1 also comprises an auxiliary clamping unit 60 detachably attachable to the base 2 , preferably by means of pins 61 a , 61 b ​​insertable into corresponding holes 3 a , 3 b provided on the same base 2 .

[0032] Specifically, the first clamping unit 40 , the second clamping unit 50 and the auxiliary clamping unit 60 respectively include: a first pair of clamps 42a, 42b carried by the first base 43 , a second pair of clamps 52a, 52b carried by the second base 53 , and a third pair of clamps 62a, 62b carried by the third base 63 .

[0033] Advantageously, the first, second and third bases 43, 53, 63 are detachably connected to the first, second and third bases 46, 56, 66, respectively.

[0034] The clamping jaws 42a, 42b, 52a, 52b, 62a, 62b of each clamping unit 40, 50, 60 are situated opposite one another and are movable relative to one another by means of control means 44, 54, 64, which may themselves be of a known type.

[0035] The clamps 42a, 42b, 52a, 52b, 62a, 62b comprise ridges 45, 55, 65 or knurls on at least a portion of their inner surface to improve the grip on the tubular element 100, 200.

[0036] The pairs of clamps 42a and 42b, 52a and 52b, 62a and 62b together with the corresponding bases 43, 53, 63 can be interchanged with each other or with other clamps having different sizes and / or characteristics, and are reversible; that is, each pair of clamps 42a and 42b, 52a and 52b, 62a and 62b together with the corresponding bases 43, 53, 63 can be rotated 180° relative to the middle plane of the substrate 46, 56, 66 on which it is mounted, which plane is orthogonal to the longitudinal development direction 300 of the elongated body 21.

[0037] The second clamping unit 50 is slidably engaged with the guide rail 22 mechanically coupled to the extension body 21. The second clamping unit 50 is movable along the direction 300 between a remote position away from the first clamping unit 40 and a welded position close to the first clamping unit 40, which is permanently fixed to the extension body 21.

[0038] It will be apparent to a person skilled in the art that according to another embodiment of the invention not shown in the drawings, the first clamping unit 40 is movable and the second clamping unit 50 is fixed, or both clamping units 40 , 50 are movable along the direction 300 .

[0039] The second gripper unit 50 is moved by handling means comprising a first pinion 23 engaging with a first rack 24 mechanically associated with the elongated body 21 .

[0040] The first pinion 23 is at least rotationally engaged to a first end 25 a of a first shaft 25 rotatably housed in a body 57 coupled to the second base 56 and slidingly engaged with the elongated body 21 .

[0041] The second end 25b of the first shaft 25 is detachably associated at least in rotation with a first gear 4a of a bevel gear having a normal axis. The bevel gear is supported by a slide 5 which slidingly engages the base 2 .

[0042] Preferably, the second end 25b of the first shaft 25 has a side wall with a polygonal cut so as to be received in a complementary polygonal seat formed in the first gear 4a.

[0043] In order to adjust the stroke of the slide 5 , a preferably adjustable, exchangeable stop element 6 is associated with the base 2 .

[0044] The second gear 4b of the bevel gear pair is at least rotationally coupled to the second shaft 7. The two second pinions 8a, 8b are also at least rotationally coupled to both ends of the second shaft 7.

[0045] The second pinions 8a, 8b engage two second racks 9a, 9b arranged on opposite sides of the base 2, respectively.

[0046] The second shaft 7 is rotatable by means of a hand wheel 10. The hand wheel 10 is detachably attached to the second shaft 7, preferably by the interposition of adjustable braking means (not visible in the drawings).

[0047] For example, the adjustable braking means may be an annular spacer made of a rigid material, preferably metal, which is fitted on the second shaft 7 and interposed between the side wall of the slide 5 and the operating handwheel 10 .

[0048] In this way, by adjusting the axial compression force applied by the operating hand wheel 10 on the annular spacer, a braking torque can be generated, which can resist the driving torque acting on the second shaft 7 and thereby slow down and / or control the movement of the second clamping unit 50.

[0049] Besides the alignment and fastening means 20 , a molded support 11 for the adjustable position and height of the tubular elements 100 , 200 , and four transport handles 12 a , 12 b , 12 c and 12 d facilitating the movement of the machine 1 are also mounted on the base 2 .

[0050] The machine 1 also comprises a heating device 70 comprising, in a self-contained manner, a heating plate 71 on which are mounted casting sleeves 72 a , 72 b for bag-fusion welding of tubular elements 100 , 200 .

[0051] Preferably, the heating device 70 is associated with an oscillating arm 13 articulated to the base 2 so that it can be moved into a welding position in which it can approach and engage the ends of the tubular elements 100 , 200 to be welded.

[0052] According to the present invention, Figure 6 and Figure 7 As shown, the alignment and fastening device 20 is a separate component, mechanically connected / disconnected to the base 2 .

[0053] The aligning and fastening device 20 is switchable from a first operating configuration in which it is interconnected with the machine 1 to a second operating configuration in which it is used as a stand-alone device.

[0054] In this respect, a first coupling member 26 , two elements in the illustrated example, is arranged on the alignment and fastening device 20 in order to establish a mechanical connection with a second coupling member 14 arranged at the base 2 .

[0055] Each first coupling member 26 comprises a threaded headless screw 27 with a substantially pointed end engaging with a corresponding threaded hole 28 formed in the elongated body 21 facing a seat 29 for the corresponding second coupling member 14 .

[0056] Each second coupling member 14 comprises a pin 15 which is cantilevered from the base 2 so as to fit into a corresponding seat 29 .

[0057] Advantageously, the pin 15 has a self-centering hole 16 , substantially shaped like a funnel, capable of interacting with and accommodating a substantially pointed end of the threaded pin 27 .

[0058] It should be noted that screwing in the threaded pin 27 causes its interference with the pin 15, since it coincides with the self-centering shaped hole 16, and self-centering of the alignment and fastening device 20 relative to the base 2 is also achieved during the transition from the second operating condition to the first operating condition.

[0059] When the aligning and fastening device 20 is separated from the base 2 and used independently, ie in the second operating condition, the crank handle 30 is detachably attached to the second end 25 b of the first shaft 25 , at least integrally disengaged from the first gear 4 a in rotation, to move the second clamping unit 50 .

[0060] Advantageously, friction means 31 are engaged to the first shaft 25, interposed between the crank 30 and the body 57, so as to dampen and / or control the drag of the second clamping unit 50, in particular when the elongated body 21 is in a substantially vertical position.

[0061] The handle 32 is detachably attached to the elongated body 21 and facilitates a user thereof to grasp and carry the alignment and fastening device 20 in the second operating condition.

[0062] The machine according to the invention operates essentially as follows.

[0063] When bench welding of pipes and fittings is required, for example to make prefabricated joints, the aligning and tightening device 20 is in its first operating configuration, ie mechanically connected to the base 2 by means of the first and second couplings 26 , 14 .

[0064] In this operating configuration, welding operations are performed as Figure 3 and Figure 4 As shown, first one of the two tubular elements 100, 200 is fastened between the clamps 42a, 42b of the first clamping unit 40, and possibly between the clamps 62a, 62b of the auxiliary clamping unit 60, and the other of the two tubular elements 100, 200 is fastened between the clamps 52a, 52b of the second clamping unit 50, and finally placed on the forming support 11.

[0065] After the ends of the two tubular elements 100, 200 to be welded have been prepared and the heating device 70 has reached the correct temperature, the heating device 70 is moved by acting on the swing arm 13 to the welding position, i.e., the position where the casting sleeves 72a, 72b can come together and engage with the ends of the tubular elements 100, 200 to be welded.

[0066] At this point, acting on the operating handwheel 10 , it is possible to move the second clamping unit 50 so that it slides towards the first clamping unit 40 until the ends of the two tubular elements 100 , 200 are coupled and joined to the casting sleeves 72 a , 72 b .

[0067] After the heating time has ended, the two tubular elements 100 , 200 are pulled apart and the heating device 70 is removed, after which the two tubular elements 100 , 200 are brought back together and immediately joined, the welding pressure being gradually increased by turning the hand wheel 10 until the slide 5 comes into contact with the stop element 6 .

[0068] In this operating configuration, the adjustable brake means associated with the operating handwheel 10 are able to counteract the forces generated by the two tubular elements 100 , 200 due to their thermal expansion without excessive muscle action by the user.

[0069] By means of adjustable braking means, it is in fact possible to generate a braking torque to oppose the driving torque acting on the second shaft 7 and thereby slow down and / or control the movement of the second clamping unit 50 .

[0070] Once the welding phase is completed, the contact pressure is cancelled and the two tubular elements 100 , 200 can be removed from the machine 1 .

[0071] When on-site welding of pipes and fittings is required, for example to connect previously prefabricated joints, the alignment and tightening device 20 will be brought into its second operating configuration, ie mechanically disconnected from the base 2 to be used as a self-contained independent structural unit.

[0072] In practice, unscrewing the threaded bolts 27 disengages them from their corresponding pins 15 , allowing the alignment and fastening device 20 to be separated from the base 2 .

[0073] In this operating condition, as described above, the second end 25 b of the first shaft 25 is engaged with the crank handle 30 with the friction device 31 interposed, thereby allowing the second clamping unit 50 to move.

[0074] Additionally, a handle 32 is attached to the elongated body 21 to facilitate grasping and carrying of the alignment and fastening device 20 by a user thereof.

[0075] In the second operating condition of the aligning and fastening device 20, the welding operation is substantially the same as described in the first operating condition, but in this case the movement of the second clamping unit 50 is achieved by acting on the crank handle 30, while the heating device 70 is manually gripped by the user.

[0076] To mount the alignment and fastening device 20 on the base 2, the steps described above with regard to its mechanical disconnection are carried out in reverse order.

[0077] In practice, it has been found that the invention achieves the intended aim and objects, providing a welding machine which satisfactorily combines the advantages of using a bench-top welder with the advantages of using a portable welder.

[0078] In fact, using the welding machine of the present invention, only a single piece of equipment is required for both bench-top welding of pipes and fittings as well as field welding thereof.

[0079] Another advantage of the welding machine according to the invention is that it achieves the above-mentioned results in a practical and relatively inexpensive manner.

[0080] Furthermore, the welding machine according to the present invention can ensure reliability and safety in use to the greatest extent possible due to its special design features.

[0081] The materials used, as well as the sizes and shapes, may be any according to requirements and to the state of the art.

[0082] This application claims the benefit of Italian Patent Application No. 102023000013128 filed on June 26, 2023, the subject matter of which is incorporated herein by reference.

Claims

1. A welding machine, comprising a base, the base supporting an alignment and fastening device; the alignment and fastening device comprising a guide means, a first clamping unit and a second clamping unit, the first clamping unit and the second clamping unit respectively engaging a first tubular element and a second tubular element to be joined by welding; at least one of the first clamping unit and the second clamping unit being movable relative to each other from a remote position to a near welding position; the base being associated with a heating device for welding the first and second tubular elements; the welding machine being characterized in that the alignment and fastening device is an automated component and is mechanically connected to / disconnected from the base; the alignment and fastening device switches from a first operating configuration in which the alignment and fastening devices are mutually connected to the welding machine to a second operating configuration in which the alignment and fastening devices are used as independent devices.

2. The welding machine according to claim 1, characterized in that The welding machine comprises a first coupling member arranged corresponding to the aligning and fastening device, the first coupling member being suitable for establishing a mechanical connection with a second coupling member arranged corresponding to the base.

3. The welding machine according to claim 2, characterized in that Each first coupling member comprises a threaded grub screw having a substantially pointed end; said threaded grub screw engages in a corresponding threaded hole formed in said alignment and tightening device; said threaded hole faces a seat for a corresponding second coupling member.

4. The welding machine according to claim 2, characterized in that Each second coupling member includes a pin cantilevered from the base and fitted into a corresponding seat; The pin has a self-centering shaped hole, substantially funnel-shaped and interacting with the substantially pointed end of the threaded pin and to receive the threaded pin.

5. The welding machine according to claim 1, characterized in that The guiding device comprises an elongated body supporting the first and second clamping units; the first clamping unit is coupled to one end of the elongated body; the second clamping unit is slidably coupled to the elongated body and is movable relative to the first clamping unit.

6. The welding machine according to claim 1, characterized in that The welding machine comprises handling means of the second gripping unit.

7. The welding machine according to claim 5, characterized in that The welding machine comprises a handling device of the second clamping unit; the handling device comprises a first pinion housed in the second clamping unit; the first pinion engages a first rack, which is mechanically associated with the slender body and is integrally engaged to the first end of the first shaft at least in rotation.

8. The welding machine according to claim 8, characterized in that The handling means comprises a crank which is detachably associated at least in rotation to the second end of the first shaft.

9. The welding machine according to claim 8, characterized in that The handling means comprises friction means engaged to the first shaft.

10. The welding machine according to claim 8, characterized in that The handling device includes a bevel gear with a normal axis, the bevel gear is supported by a sliding member slidably engaged to the base; the first gear of the bevel gear is detachably engaged to the second end of the first shaft at least in rotation; the second gear of the bevel gear is engaged to the second shaft at least in rotation; at least a second pinion engaged with at least a second rack associated with the base is engaged to the second shaft as a whole at least in rotation.

11. The welding machine according to claim 10, characterized in that The handling means comprises a hand wheel which is detachably attached to the first end of the second shaft at least in rotation and into which an adjustable braking means is interposed.

12. The welding machine according to claim 1, characterized in that The welding machine comprises at least one handle detachably associated with the alignment and fastening device.

13. The welding machine according to claim 1, characterized in that The welding machine includes an auxiliary clamping unit detachably associated with the base.

14. The welding machine according to claim 13, characterized in that Said first and second clamping units and said auxiliary clamping unit comprise respective pairs of opposed jaws movable transversely to said elongated body under the action of actuation of relevant control means; said pairs of jaws being interchangeable and reversible.

15. The welding machine according to claim 1, characterized in that The welding machine comprises an oscillating arm having an end hinged to the base; the other end of the oscillating arm is associated with the heating device; the heating device can be moved to a welding position, in which the heating device is connected to the ends to be welded of the first and second tubular elements and engages with the ends to be welded of the first and second tubular elements.

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