Machines for welding molded elements made of plastic material

Abstract

The machine (1) comprises one welding device (3) for one of the first forming elements (4) and one of the second forming elements (5) each provided with at least one area to be welded (6), the welding device (3) comprising first holding means (8) and second holding means (9) adapted to hold the forming elements (4, 5) with the areas to be welded (6) facing each other, one heating plate (17) adapted to heat the areas to be welded (6) and at least one working element parallel to the second forming element (5). The welding device (3) comprises one motion assembly (14) for the first holding means (8) and one motion unit (18) adapted to move the heating plate (17) along the working direction (W), at least one of the motion assemblies (14) or the motion unit (18) comprising one electric actuator (21), and the welding device (3) comprises one synchronization mechanism (22) adapted to move the first holding means (8) simultaneously with the heating plate (17) along the working direction (W).

Description

[Technical field]

[0001] The present invention relates to a machine for welding molded elements made of plastic material. [Background technology]

[0002] In the building industry, machines are known for making window / door frames made from known plastic material parts, specifically PVC.

[0003] Such window / door frames usually consist of a series of shaped elements made from a plastic material formed by extrusion or similar techniques, which are welded together to create a perimeter frame onto which a central panel made from glass or other material can be installed, to obtain a door or window, and / or to create an associated fixed frame which can be used in a wall / partition.

[0004] The molding elements extend along their respective longitudinal directions and each have an area to be welded where at least one end is located.

[0005] The weld area is the surface of the molding element that is to be joined by welding the molding element itself to another molding element.

[0006] The areas to be welded are transverse to the associated longitudinal direction and are generally obtained by cutting the shaped element along a direction inclined at an angle of 45° to the longitudinal direction.

[0007] Known types of machines comprise a number of welding devices adapted to weld together areas to be welded of the forming elements.

[0008] In particular, known types of machines have a support base on which the welding device is movable according to the size of the forming element and the position of the area to be welded defined by the support base.

[0009] Generally, known welding devices include: - first holding means of the first molding element and second holding means of the second molding element such that the areas to be welded face each other; a heating plate adapted to heat the areas to be welded, the heating plate being movable between at least one fixed position in which it moves away from the shaping element, a first operating position positioned between the areas to be welded, and a second operating position in contact with the areas to be welded.

[0010] The holding means are movable relative to one another to bring the heated areas to be welded into contact with one another and to press the forming elements together to effect the weld.

[0011] In this way, in fact, the partially melted areas to be welded are in intimate contact with one another and the plastic material hardens again when cooled, keeping the moulded elements together.

[0012] Known types of machines for welding shaped elements have a first holding means which is movable relative to the second holding means, whilst the second holding means is fixed.

[0013] For this purpose, the known welding device is further provided with at least one movement assembly of the first holding means, the at least one movement assembly being adapted to displace the first forming element along at least one working direction substantially parallel to a longitudinal direction of the second forming element between at least one moving away position from the second forming element and at least one moving approach position to the second forming element.

[0014] Thus, in the moved away position, the shaping elements are spaced apart from one another and make it possible to position further components of the welding device, precisely heating plates and the like, for machining the area to be welded.

[0015] The known device also comprises a movement unit for the heating plate, which is adapted to move the heating plate along a working direction between a first operating position and a second operating position.

[0016] In fact, the heating plate is also movable relative to the second forming element to effect heating of the associated area to be welded.

[0017] In particular, in machines of known type, the movement assembly is motorized, while the movement unit comprises elastic means adapted to maintain the heating plate in a first operating position. The heating plate is moved along the working direction towards a second operating position by the action of a first forming element, which pushes the heating plate towards the second forming element by bringing it into contact with the heating plate by means of the movement assembly. Thus, only at the moment when the first forming element comes into contact with the heating plate, does the heating plate move to the second operating position.

[0018] When heating of the area to be welded is completed, the motion assembly returns the first forming element to the moved away position and simultaneously the resilient means returns the heating plate to the first operating position.

[0019] However, such a movement system is highly inaccurate and does not allow effective heating of the moulding elements: in fact, as a result of the softening of the plastic material of the first moulding element, the heating plate, by the effect of the elastic means, tends to return to the first operating position and move away from the second moulding element.

[0020] During heating, it is therefore necessary to continuously adjust the position of the first molding element so that the heating plate is always pressed into contact with the second molding element.

[0021] Moreover, such a motion system necessarily causes the first mold element to be placed in contact with the heating plate for a longer period of time than the second mold element, with the result that at the end of heating, the area to be welded of the first mold element has a larger amount of molten plastic material than the area to be welded of the second mold element.

[0022] As a result of joining and pressing the molded elements together, the molten plastic material compresses and cools along the welded surfaces where the molded elements are not perfectly symmetrical with respect to each other. This drawback, in addition to compromising the aesthetic effect of the window / door frame, can also cause inaccurate welding and structural defects of the window / door frame, which can cause leakage and / or poor sealing between the door / window and the associated fixed frame.

[0023] Further types of machines of known types have both a movement assembly and a movement unit provided with an electric actuator, by means of which the heating plate can be moved independently along the working direction. However, the solution of the present embodiment does not ensure a synchronous movement of the first holding means and the heating plate and heating of the area to be welded for the same time.

[0024] A further drawback of machines of the known type is the fact that they are forced to be inconveniently combined with processing machines adapted to remove the weld bead formed during the melting of the shaped elements.

[0025] In fact, in the area where the molding elements are welded, an excess of the molten material flows out and forms a bead that protrudes from the exposed surface of the molding elements.

[0026] For this reason, in order to give the finished window / door frame a good aesthetic appearance, the shaped elements, once welded, need to be transferred to a processing machine and subjected to machining to remove the weld bead.

[0027] This process of removing the weld bead significantly impacts the cost and timing of the window / door frame processing, and furthermore can be quite complicated to perform and carries the risk of causing damage and / or aesthetic defects, especially where there are radial and / or curved surfaces and the weld area is located.

[0028] In this context, patent application WO 2013 / 132406 partially solves this problem and in fact describes a welding device provided with removal means adapted to create a groove on the peripheral edge of the area to be welded such that, following welding of the shaped element, the weld bead extends inwardly into the shaped element and thus is not visible on the exposed surface of the window / door frame.

[0029] However, the machine described by WO 2013 / 132406 requires that the removal means be arranged in a reference plane substantially parallel to the area to be welded and that both holding means are movable to bring the area to be welded into contact with the removal means itself.

[0030] In this manner, the removal means machines simultaneously and symmetrically on both areas to be welded to produce a weld area that is itself symmetrical and free of aesthetic and / or structural defects.

[0031] It is clear that in order to carry out rapid and optimal machining of the areas to be welded, movement systems similar to the movement units of known heating plates are hardly available for the removal means described by WO 2013 / 132406.

[0032] In particular, by applying the removal means described by WO 2013 / 132406 to known types of machines, the welding device would not allow a synchronized movement of the first holding means and the removal means themselves, which would not ensure symmetrical machining of the area to be welded and would also risk damaging the structural features of the window / door frame. [Prior art documents] [Patent documents]

[0033] [Patent Document 1] International Publication No. 2013 / 132406 Summary of the Invention

[0034] The main object of the invention is to devise a machine for welding molded elements made of plastic material which makes it possible to optimally and homogeneously heat the areas of the molded elements to be welded.

[0035] Within such technical objectives, one object of the present invention is to obtain a window / door frame with excellent aesthetic effect and without structural defects.

[0036] A further object of the invention is to devise a machine for welding molded elements made of plastic material, which allows convenient and easy movement of the associated components and at the same time has small dimensions and is structurally simple.

[0037] Another object of the invention is to devise a machine for welding shaped elements made of plastic material that eliminates the need to remove the weld bead and transfer the welded shaped element to a further machine adapted to finish the welded area after removal of the weld bead.

[0038] Another object of the present invention is to devise a machine for welding molded elements made of plastic material, which is simple, rational, easy and effective to use, as well as being able to overcome the aforementioned drawbacks of the prior art within the scope of a cost-effective solution.

[0039] The aforementioned object is achieved by this machine for welding molded elements made from plastic material having the features of claim 1.

[0040] Other features and advantages of the present invention will become more apparent from the description of a preferred, but not exclusive, embodiment of a machine for welding molded elements made of plastic material, illustrated as an indicative but non-limiting example in the accompanying drawings, in which: [Brief description of the drawings]

[0041] [Figure 1] FIG. 1 is an axonometric view of a machine according to the invention; [Diagram 2] 1A-1D are axonometric views of a welding device according to the invention in an operating configuration from different angles; [Diagram 3] 1A-1D are axonometric views of a welding device according to the invention in an operating configuration from different angles; [Figure 4] FIG. 2 is a detailed axonometric view of components of a welding device according to the present invention. [Diagram 5] 1 is a top view of a welding device according to the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] With particular reference to these figures, the number 1 indicates overall a machine for welding molded elements made of plastic material.

[0043] The machine 1 can be used to weld molding elements made from a plastic material, preferably PVC, to make window / door frames.

[0044] However, it cannot be excluded that the moulding element is made from a heat-sealable plastic material other than PVC and / or a plastic material loaded with a reinforcing material in the form of fibres, such as for example glass fibres or the like. Likewise, it cannot be excluded an embodiment solution in which the moulding element is partly made from a plastic material and partly made from a different material, in a manner similar to some materials of known type provided with a canopy, an outer cover, an inner core, for example made from metal, wood or the like.

[0045] The machine 1 for welding molding elements made of plastic material comprises at least one support base 2 and at least one welding device 3 of at least one first molding element 4 and at least one second molding element 5, which extend along their respective longitudinal directions forming part of the perimeter window / door frame.

[0046] In particular, in the embodiment shown in the figures, the machine 1 comprises two welding devices 3 adapted to weld a first forming element 4 to a respective second forming element 5 .

[0047] The first forming element 4 and the second forming element 5 each have at least one area 6 to be welded, in which at least one associated edge is located.

[0048] In the context of this disclosure, the phrase "area to be welded" refers to a surface of a molding element that is itself joined to another molding element by welding according to a method described in more detail later in this disclosure.

[0049] In particular, each of the molding elements 4, 5 has at least two to-be-welded areas 6 defined at their respective ends.

[0050] Suitably, the areas to be welded 6 are inclined at an angle of between 10° and 80° to the longitudinal direction of the molding elements 4,5.

[0051] Preferably, the area to be welded 6 is inclined at an angle substantially equal to 45°.

[0052] The support base 2 extends along a positioning direction F, the welding device 3 is associated with the support base 2 and is mutually movable such that the welding device 3 is itself located at the end of the first forming element 4 .

[0053] The welding device 3 comprises at least one base frame 7 associated with the support base 2 and holding means 8, 9 for the forming elements 4, 5 associated with the base frame 7 and adapted to hold the forming elements 4, 5 with the areas 6 to be welded facing each other.

[0054] In particular, the retaining means 8 , 9 comprise first retaining means 8 of the first moulding element 4 and second retaining means 9 of the second moulding element 5 .

[0055] Each of the holding means 8,9 comprises at least one holding surface 10 of the associated forming element 4,5 which is substantially horizontal, and at least one clamping assembly 11 adapted to maintain the forming element 4,5 fixed to the associated holding surface 10.

[0056] The clamping assembly 11 is a type of device that is vertically actuated by a piston cylinder and is adapted to press the forming elements 4 , 5 onto a holding surface 10 .

[0057] Each of the retaining means 8,9 also comprises at least one abutment surface 12 of the associated forming element 4,5 which is substantially vertical, and a retaining assembly 13 adapted to maintain the forming element 4,5 in contact with the associated abutment surface 12.

[0058] The holding assembly 13 is of the type of movable hook, which catches the forming elements 4 , 5 and pulls them towards the abutment surface 12 .

[0059] The holding means 8,9 are movable relative to one another to move the forming elements 4,5 towards / away from one another.

[0060] More specifically, the first holding means 8 is movable to displace the first molding element 4 between a moved away position and a moved closer position, while the second holding means 9 is fixed on the base frame 7.

[0061] The welding device 3 comprises at least one movement assembly 14 of the first holding means 8, which is associated with the base frame 7 and adapted to displace the first forming element 4 along at least one working direction W between at least one moving away position from the second forming element 5 and at least one moving approach position to the second forming element 5.

[0062] The working direction W is substantially parallel to the longitudinal direction of the second forming element 5 .

[0063] The areas 6 to be welded of the first shaping element 4 and the second shaping element 5 lie respectively on a first work plane P1 and a second work plane P2 which are substantially parallel to each other.

[0064] In the moved away position, the first working surface P1 and the second working surface P2 are disposed at a predetermined distance D1 from each other, while in the moved closer position, the first working surface P1 and the second working surface P2 are substantially coincident.

[0065] The motion assembly 14 includes: first guiding means 15 associated with the base frame 7 and extending along the working direction W; a first carriage 16 associated in sliding manner with the first guiding means 15 and supporting the first holding means 8; Equipped with.

[0066] The welding device 3 also comprises at least one heating plate 17 associated with the base frame 7 and adapted to heat the area 6 to be welded.

[0067] When placed in contact with the relevant to-be-welded areas 6, a heating plate 17, for example in the type of an electrical resistance plate or similar heating device, causes at least partial melting of the plastic material of the molding elements 4, 5, which are then joined and pressed together, bringing the molten plastic material into contact, using the movement assembly 14. Upon cooling, the plastic material hardens and keeps the molding elements together.

[0068] The heating plate 17 is at least one fixed position that moves away from the molding elements 4, 5; a first operating position positioned between the areas to be welded 6; a second operating position in contact with the area to be welded 6; It is possible to move between

[0069] More specifically, the heating plate 17 lies on a reference plane B that is substantially parallel to the working planes P1, P2.

[0070] In the first operating position, the reference plane B is located at a distance D2 from the second working plane P2.

[0071] Furthermore, the welding device 3 comprises at least one movement unit 18 of the heating plate 17. The movement unit 18 is associated with the base frame 7 and adapted to move the heating plate 17 along a working direction W between a first operating position and a second operating position.

[0072] The heating plate 17 is therefore movable relative to the second forming element 5 and is moved closer to the associated area 6 to be welded.

[0073] The motor unit 18 is second guiding means 19 associated with the base frame 7 and extending along the working direction W; a second carriage 20 associated in sliding manner with the second guide means 19 and supporting at least the heating plate 17; Equipped with.

[0074] At least one of the motion assemblies 14 or motion units 18 includes at least one electrically powered actuator 21 .

[0075] The electric actuator 21 is adapted to move the first holding means 8, and consequently the heating plate 17, in a very precise and accurate manner.

[0076] According to the present invention, the welding device 3 comprises at least one synchronization mechanism 22 positioned between the movement assembly 14 and the movement unit 18 and adapted to move the first holding means 8 simultaneously with the heating plate 17 along the working direction W.

[0077] The synchronization mechanism 22 is adapted to move both the first holding means 8 and the heating plate 17 simultaneously, so that the area to be welded 6 is brought into contact with the heating plate 17 at substantially the same time. More specifically, during the movement, the heating plate 17 is always maintained in a plane of symmetry between the first holding means 8 and the second holding means 9.

[0078] Similarly, when heating is completed, the contact between the area to be welded 6 and the heating plate 17 is simultaneously substantially broken.

[0079] In particular, each stroke fraction of the first holding means 8 along the working direction W corresponds to a stroke fraction of the heating plate 17 along the working direction itself.

[0080] Advantageously, the electric actuator 21 is mounted on either the first carriage 16 or the second carriage 20 .

[0081] More specifically, only one of either the motion assembly 14 or the motion unit 18 includes a motorized actuator 21 , while the other of either the motion assembly 14 or the motion unit 18 is absent of the motorized actuator 21 .

[0082] Thus, the synchronization mechanism 22 enables the first holding means 8 and the heating plate 17 to move simultaneously using a single electric actuator 21 .

[0083] By this measure it is possible to reduce the number of components of the machine 1, making the welding device 3 more compact.

[0084] To this end, the synchronization mechanism 22 comprises at least one linking arm 23 associated with the first carriage 16 and with the second carriage 20 .

[0085] Operation of the electric actuator 21 causes the taking-up of either the first carriage 16 or the second carriage 20 by means of the connecting arm 23 along the working direction W of the other.

[0086] In the embodiment shown, the motion assembly 14 includes an electric actuator 21 mounted to the first carriage 16 .

[0087] In particular, the electric actuator 21 is at least one unfolding screw shaft 24 associated with the first carriage 16 by means of a threaded nut 25 and extending parallel to the first guide means 15; at least one electric motor 26 adapted to set the deployment screw shaft 24 in rotation; Equipped with.

[0088] Rotation of the spreading screw shaft 24 shifts the threaded nut 25 relative to it, thereby causing a sliding of the first carriage 16 along the working direction W.

[0089] However, it cannot be excluded that the movement unit 18 comprises an electric actuator 21 mounted on a second carriage 20 .

[0090] Also, embodiments cannot be excluded in which both the motion assembly 14 and the motion unit 18 have associated electric actuators 21 and in which synchronization is performed by different means, for example by an electronic link between the electric motors or by using software.

[0091] Usefully, the articulated arm 23 is rotatably associated with the base frame 7 about a substantially vertical hinge axis A.

[0092] The connecting arm 23 is therefore constrained to the base frame 7 and is able to rotate about the hinge axis A during movement of the first holding means 8 .

[0093] In particular, the connecting arm 23 includes at least one hinge point 27 to the base frame 7 .

[0094] A hinge point 27 is defined at one end of the connecting arm 23 .

[0095] The connecting arm 23 also includes at least one first connection point 28 to the first carriage 16. The first connection point 28 is defined at an opposite end of the connecting arm 23.

[0096] Additionally, the connecting arm 23 includes at least one second connection point 29 to the second carriage 20. The second connection point 29 is positioned between the hinge point 27 and the first connection point .

[0097] More specifically, the connecting arm 23 extends along the deployment direction S, and the points 27, 28, 29 are aligned with one another along the deployment direction S.

[0098] Advantageously, the points 27, 28, 29 are arranged relative to one another so as to achieve the following distance ratio relationships: the distance between the first connection point 28 and the hinge point 27, indicated on the drawings with the reference D3; the ratio of the distance between the second connection point 29 and the hinge point 27, indicated on the drawing by reference D4, is substantially the distance between the working planes P1 and P2, indicated in the drawings by the reference D1; - corresponds to the ratio of the distance between the reference plane B and the working plane P2, shown in the drawings as reference number D2.

[0099] This arrangement of points 27, 28, 29 essentially causes the first holding means 8 and the heating plate 17 to move at a respective speed which is inversely proportional to their respective distance from the second holding means 9, i.e. from the area 6 of the second forming element 5 to be welded.

[0100] Therefore, the heating plate 17 moves slower than the first holding means 8 .

[0101] In this way, the areas to be welded 6 come into contact with the heating plate 17 at substantially the same time, and at the same time, the areas move away therefrom at substantially the same time. The areas to be welded 6 are therefore heated for the same time so as to produce the same amount of molten plastic material. As a result of joining and pressing the molding elements 4, 5, the molten plastic material compresses and cools along the welding plane, where the molding elements 4, 5 are arranged symmetrically with respect to each other.

[0102] In the embodiment shown in the figures, the distance D1 between the work plane P1 and the work plane P2 is substantially twice the distance D2 between the reference plane B and the work plane P2. Similarly, the distance D3 between the first connection point 28 and the hinge point 27 is substantially twice the distance D4 between the second connection point 29 and the hinge point 27.

[0103] Thus, according to this embodiment, the heating plate 17 moves at a speed substantially equal to half the speed of the first holding means 8 so as to contact the second forming element 5 at the time that the first forming element 4 contacts the heating plate itself.

[0104] Usefully, the connecting arm 23 comprises a first pivot 30 associated with the first connection point 28, and the first carriage 16 comprises a first guide 31 which supports the first pivot 30 in a sliding manner and extends transversely to the working direction W.

[0105] In particular, the first guide 31 extends perpendicular to the working direction W.

[0106] More specifically, during the rotation of the articulated arm 23 about the hinge axis A, the first articulation point 28 describes a curved trajectory, which is provided with a first linear component that is substantially parallel to the working direction W and is responsible for the movement of the first carriage 16 along said direction, and a second linear component that is substantially perpendicular to the first linear component. The first guide 31 thus supports the sliding of the first pivot 30 along the second linear component.

[0107] Advantageously, the first pivot 30 is rotatably associated with the link arm 23 about an associated axis of rotation R1 substantially parallel to the hinge axis A.

[0108] More specifically, the first pivot 30 is rotatable due to friction with the first guide 31. By this means, it is possible to easily slide the first pivot 30 along the first guide 31, making the movement of the connecting arm 23 extremely easy.

[0109] Usefully, the connecting arm 23 has a second pivot 32 associated with the second connection point 29, and the second carriage 20 has a second guide 33 which supports the second pivot 32 in a sliding manner and extends transversely to the working direction W.

[0110] In particular, the second guide 33 extends perpendicular to the working direction W.

[0111] More specifically, during the rotation of the connecting arm 23 about the hinge axis A, the second connecting point 29 further describes a curved trajectory, which is provided with a first linear component that is substantially parallel to the working direction W and is responsible for the movement of the second carriage 20 along said direction, and a second linear component that is substantially perpendicular to the first linear component. The second guide 33 thus supports the sliding of the second pivot 32 along the second linear component.

[0112] Advantageously, the second pivot 32 is rotatably associated with the link arm 23 about an associated axis of rotation R2 substantially parallel to the hinge axis A.

[0113] More specifically, the second pivot 32 is rotatable due to friction with the second guide 33. By this means, it is possible to facilitate sliding of the first pivot 32 along the first guide 33, facilitating the movement of the connecting arm 23.

[0114] Usefully, the welding device 3 also comprises means 34, 35 for displacing the heating plate 17 between the home position and the first operating position.

[0115] The displacement means 34, 35 comprise at least one unit of forward movement 34 adapted to move the heating plate 17 along a substantially horizontal operating direction C between a home position and a first operating position.

[0116] More specifically, in position, the heating plate 17 is set in a rearward position from the forming elements 4, 5 in order to make it possible to carry out further machining operations without cluttering the working area.

[0117] As shown in FIG. 3, the forward motion 34 unit is at least one support frame 36 for the heating plate 17; at least one induction assembly 37 associated with a support frame 36 extending and sliding along an operating direction C to support the heating plate 17; at least one actuator assembly 38, 39 associated with the support frame 36 and adapted to move the heating plate 17 along an operating direction C; Equipped with.

[0118] The direction of movement C is substantially horizontal.

[0119] The actuator assemblies 38 , 39 are a type of controlled axis motion system that allows for high precision motion of the heater plate 17 .

[0120] In the embodiment shown in the figures, the actuator assembly 38 , 39 comprises a motor device 38 associated with the support frame 36 and an articulated arm 39 positioned between the motor device 38 and the heating plate 17 .

[0121] The motor device 38 is of the electric motor type and is adapted to set an articulated arm 39 in rotation, the movement of which causes the heating plate 17 to slide along the operating direction C.

[0122] However, it cannot be excluded that the actuator assemblies 38, 39 are of different types.

[0123] The displacement means 34, 35 also comprise at least one slide assembly 35 adapted to move the heating plate 17 along a substantially vertical transport direction T.

[0124] The function of the slide assembly 35 is to effectively move the heating plate 17 further when not needed.

[0125] The slide assembly 35 includes: at least one guide unit 40 associated with the second carriage 20, extending along the transport direction T and supporting the support frame 36 by sliding; at least one actuation assembly associated with the support frame 36 and adapted to move the heating plate 17 along a transport direction T; Equipped with.

[0126] In a preferred embodiment, the actuating unit, not shown in detail in the figures, is of the type of fluid-operated cylinder positioned between the second carriage 20 and the support frame 36 .

[0127] Usefully, the welding device 3 also comprises removal means 41 adapted to remove a portion of the plastic material from the area 6 to be welded.

[0128] More specifically, the removal means 41 are adapted to create at least one groove in the peripheral edge of the area 6 to be welded.

[0129] In particular, the removal means 41 are adapted to create at least a groove in which the exposed faces of the molding elements 4,5 are located.

[0130] In the context of this disclosure, the phrase "exposed surface" is intended to mean a surface of the molding element that is substantially flat and that lies substantially parallel to the lateral plane of the window / door frame into which the molding element itself is fabricated, and that remains exposed when the window / door frame is assembled. In practice, when the window / door frame is assembled with a wall or partition, the exposed surface is the surface of the molding element that faces either the inside or outside of the wall or partition.

[0131] More specifically, the removal means 41 are also adapted to create grooves in which the sides of the molding elements 4,5 sit.

[0132] In the context of this disclosure, the phrase "side" is intended to mean the surface of the molding element, which lies substantially perpendicular to the transverse plane of the window / door frame for which the molding element itself is made. In the case of a door or window, the inner side of the molding element is intended to substantially capture the central panel (e.g., pane of glass) of the window / door frame, and the outer side is intended to define the outer periphery of the window / door frame that rests against the window frame / door frame attached to the wall or partition. On the other hand, in the case of a window / door frame frame, the inner side of the molding element is intended to rest against the door or window sash (when approaching), while the outer periphery is intended to face the wall or partition to which the frame is attached.

[0133] The groove ensures that, following welding of the molding elements, the weld bead extends towards the inside of the molding elements 4, 5 and is thus not visible from the outside.

[0134] For the purposes of this disclosure, the phrase "weld bead" refers to a portion of excess molten plastic material, which is compressed during joining of the molded elements and may protrude beyond the face of the molded elements themselves, thus affecting the entire peripheral edge of the area 6 to be welded.

[0135] The grooves ensure that when the molding elements 4, 5 are welded together, the associated exposed faces and side surfaces are perfectly juxtaposed to one another.

[0136] Furthermore, the removal means 41 have the function of removing part of the material from which the moulding elements 4, 5 are made, positioning the faces and / or inner parts in order to allow optimal welding.

[0137] For example, the removal means 41 is further adapted to remove a thin layer of plastic material sufficient to level and flatten the area 6 to be welded.

[0138] In other words, the removal means 41 is not for shaping the grooves, but may also be absolutely essential for smoothing and correcting any cutting errors.

[0139] If such leveling is not performed, the area to be welded 6 will be too uneven and therefore unweldable.

[0140] It should also be emphasized that when the shaping elements 4,5 are already mounted on the holding means 8,9, the groove and levelling of the area to be welded 6 is made by the removal means 41 and the area to be welded 6 is then bonded and melted together without dismantling the shaping elements 4,5 from the holding means 8,9.

[0141] In other words, the installation of the forming elements 4,5 on the holding means 8,9 only needs to occur once and the welding device 3 is able to carry out all of the steps involved in machining without the need to set up and / or machine the forming elements 4,5 on another machine.

[0142] This particular feature, in addition to ensuring a remarkable execution speed, makes it possible to avoid welding due to incorrect assembly of the shaping elements 4,5 of the holding means 8,9.

[0143] Indeed, if the grooving and / or levelling is carried out on different machines and the shaping elements 4, 5 mounted on the welding device 3 which are subsequently welded, there is a risk that the positioning of the areas 6 to be welded will not be perfectly face to face and parallel, which would endanger the welding of the shaping elements themselves.

[0144] However, alternative embodiments of the invention cannot be excluded in which the machine 1 is not provided with removal means 41 and the grooving and / or levelling of the shaping elements 4, 5 is carried out in a separate milling machine before the shaping elements themselves are installed on the machine 1.

[0145] The removal means 41 is provided with a tool assembly 42 supporting a pair of working tools 43 which are rotatably movable about associated axes of rotation.

[0146] More specifically, the tool assembly 42 comprises at least one electric motor and a motor shaft associated with the motor itself, at the end of which the work tool 43 is disposed.

[0147] The electric motor is adapted to rotate about an associated axis of rotation to position the work tool 43 .

[0148] The removal means 42 is positionable between at least one rear position in which it moves away from the molding elements 4, 5, a first working position in which it is positioned between the areas to be welded 6 and in which the working tool 43 faces each of the areas to be welded 6, and a second working position in which the working tool 43 contacts the areas to be welded 6 to remove the plastic material.

[0149] In particular, in the first working position, the tool assembly 42 resides above the reference plane B.

[0150] In this position, the work tool 43 is arranged facing the relevant to-be-welded area 6, so that plastics material can be removed from both molded elements 4, 5 simultaneously.

[0151] The work tool 43 is disposed on the opposite side of the tool assembly 42 with respect to the reference plane B.

[0152] More specifically, the rotation axes are substantially parallel to each other and perpendicular to the reference plane B.

[0153] The axis of rotation is therefore perpendicular to the associated to-be-welded area 6 and inclined at 45° to the longitudinal direction of the associated forming element 4,5.

[0154] Between the first and second working positions, the tool assembly 42 is further movable along a working direction W.

[0155] Like the heating plate 17, in fact the tool assembly 42 is also movable close to the second forming element 5 in order to carry out the machining.

[0156] Advantageously, the removal means 41 are also mounted on the second carriage 20 .

[0157] As a result, like the heating plate 17, the removal means 41 is also movable synchronously together with the first holding means 8 at respective speeds which are inversely proportional to their respective distances from the second holding means 9. Thus, the synchronization mechanism 22 is also adapted to move the tool assemblies 42 so that the working tools 43 come into contact with the areas to be welded 6 at substantially the same time.

[0158] Thus, the machine 1 according to the invention allows a very precise and accurate removal of plastic material from both areas 6 to be welded at the same time.

[0159] On the other hand, the tool assembly 42 is movable along an operating direction C between the rear position and the first working position.

[0160] Usefully, the removal means 41 also comprises a positioning system 44 for the tool assembly 42 between the rear position, the first working position and the second working position.

[0161] The positioning system 44 is adapted to position the work tool 43 where the area to be welded 6 is located and to move the work tool 43 over the area to be welded 6 to remove the plastic material.

[0162] The positioning system 44 includes at least one holding frame 45 of the tool assembly 42 .

[0163] The positioning system 44 in turn comprises at least one pair of guides 46 associated with a holding frame 45, which extend parallel to the direction of movement C and support the tool assembly 42 by sliding.

[0164] Further, the positioning system 44 includes a drive assembly adapted to move the tool assembly 42 along the direction of movement C.

[0165] The drive assembly comprises a first actuator 47 and a first threaded shaft extending parallel to the direction of movement C.

[0166] The first threaded shaft meshes with a first threaded wheel 48 associated with the removal means 41 .

[0167] Rotation of the first threaded shaft causes movement of the tool assembly 42 along a direction of movement C.

[0168] Usefully, the removal means 41 are furthermore movable along the transport direction T.

[0169] For this purpose, the holding frame 45 is associated with the guiding unit 40 in a sliding manner.

[0170] The positioning system 44 comprises a second drive assembly adapted to move the removal means 41 along the transport direction T.

[0171] The second drive assembly comprises a second actuator and a second threaded shaft 49 extending parallel to the transport direction T.

[0172] The second threaded shaft 49 meshes with a second threaded wheel associated with the retaining frame 45 .

[0173] Rotation of the second threaded shaft 49 causes movement of the holding frame 45 and therefore of the tool assembly 42 along the transport direction T.

[0174] The positioning system 44 therefore allows very precise positioning of the working tool 43 in order to carry out the removal of the plastic material.

[0175] Furthermore, it should be noted that the special means of mounting the heating plate 17 and the tool assembly 42 on the same induction unit 40 make it possible to keep the overall dimensions of the welding device 3 significantly smaller, limiting their components.

[0176] The removal means 41 also comprise a suction unit adapted to suck up any residues of plastic material produced during the removal of the plastic material itself.

[0177] The suction unit is associated with the tool assembly 42 and comprises a suction port 50 defined in the working tool 43, through which the plastic material residue is conveyed towards a collection container.

[0178] For this purpose, the working tool 43 is furthermore of a helical structure, which causes the removed chip to be conveyed towards the suction port 50 to facilitate its removal. However, it cannot be excluded that the working tool 43 is of a different structure.

[0179] More specifically, the work tool 43 is positioned through the suction port 50 toward the area 6 to be welded.

[0180] Additionally, the suction unit comprises a series of brush elements 51 arranged around the suction port 50 in a radial pattern.

[0181] During removal, the brush elements 51 come into contact with the area to be welded 6 and facilitate its suction by enabling effective removal therefrom of residues made of plastic material.

[0182] Advantageously, the welding device 3 comprises storage means 52, 53 adapted to abut at least with their exposed faces on the area 6 to be welded which contains the weld bead.

[0183] More particularly, the containment means 52,53 are adapted to contain weld beads protruding from the exposed and outer faces of the molding elements 4,5.

[0184] To this end, the storage means 52, 53 are a pair of containment bodies 52 adapted to contain the weld beads protruding from the exposed faces of the molding elements 4, 5; at least one containment element 53 adapted to contain a weld bead protruding from its outer face; Equipped with.

[0185] In particular, the containment bodies 52 are arranged facing each other from opposite sides (upper and lower) of the lateral plane of the molding elements 4, 5 and are abutting with the relevant exposed surfaces of the molding elements themselves in the areas 6 to be welded and are movable towards each other.

[0186] On the other hand, the containment element 53 is adapted to abut against the outer faces of the molding elements 4 , 5 in the area 6 to be welded.

[0187] In particular, the containment element 53 is V-shaped and is intended to contact the outer faces of the molding elements 4, 5 when they are joined together.

[0188] The storage means 52, 53 are known to those skilled in the art and will not be described in detail in this disclosure.

[0189] Advantageously, the storage means 52 , 53 are furthermore mounted on the second carriage 20 .

[0190] The storage means 52 , 53 are therefore also movable along the working direction W following the movement of the first holding means 8 .

[0191] In fact, following heating of the areas to be welded 6, the heating plate 17 is brought into position and the first holding means 8 is moved into the moving approach position to join and press the forming elements 4, 5 together.

[0192] In particular, when the areas to be welded 6 are juxtaposed, the first holding means 8 further moves along the working direction W when pressing the mold elements 4, 5 together. During this step, the molten plastic material compresses and the areas to be welded 6 move closer together. In particular, the areas to be welded 6 of the first mold element 4 move towards the areas to be welded 6 of the second mold element 5.

[0193] More specifically, during use, the storage means 52, 53 are located in a reference plane B.

[0194] Special means providing storage means 52, 53 mounted on the second carriage 20 and positioned in the reference plane B allow the storage body 52 and the storage element 53 to move simultaneously with the first holding means 8 during the joining and pressing of the first forming element 4 onto the second forming element 5, ensuring optimal storage of the weld bead until the joining and pressing operation is completed and achieving an excellent aesthetic effect of the resulting welded area.

[0195] In fact, it has been confirmed that the invention described achieves its intended objectives, and in particular we wish to highlight the fact that, thanks to the synchronization mechanism, the machine for welding molding elements made of plastic material according to the invention allows optimal and homogeneous heating of the areas of the molding elements to be welded.

[0196] The synchronization mechanism is therefore to make it possible to obtain a window / door frame with excellent aesthetic effect and without structural defects.

[0197] Moreover, the machine has small dimensions and is structurally simple, while allowing convenient and easy movement of the associated components.

[0198] Finally, thanks to the removal and storage means, the machine according to the invention eliminates the need to remove the weld bead and to transport the weld shaping element to a further machine adapted to finish the weld area after removal of the weld bead itself.

Claims

1. A machine (1) for welding molding elements made of plastic material, comprising: at least one support base (2), at least one welding device (3) for at least one first molding element (4) and at least one second molding element (5) made of plastic material, said first molding element (4) and said second molding element (5) extending along a respective longitudinal direction and each provided at least at one of its ends with at least one area to be welded (6) inclined at an angle substantially between 10° and 80° to said respective longitudinal direction, said welding device (3) being at least one base frame (7) associated with said support base (2); - first holding means (8) for the first moulding element (4) and second holding means (9) for the second moulding element (5) associated with the base frame (7) and adapted to hold the moulding elements (4, 5) with the areas to be welded (6) facing each other; at least one heating plate (17) associated with said base frame (7) and adapted to heat said areas to be welded (6), said heating plate (17) being movable between at least one fixed position moving away from said shaping elements (4, 5), a first operating position positioned between said areas to be welded (6) and a second operating position in contact with said areas to be welded (6); at least one movement assembly (14) for said first holding means (8), associated with said base frame (7) and adapted to displace said first forming element (4) along at least one working direction (W) substantially parallel to said longitudinal direction of said second forming element (5) between at least one moving away position from said second forming element (5) and at least one moving approach position to said second forming element (5); at least one movement unit (18) associated with said base frame (7) and adapted to move said heating plate (17) along said working direction (W) between said first and second operating positions, At least one of the motion assemblies (14) or the motion units (18) comprises at least one electric actuator (21); The welding device (3) comprises at least one synchronization mechanism (22), which is positioned between the motion assembly (14) and the motion unit (18) and is adapted to move the first holding means (8) simultaneously with the heating plate (17) along the working direction (W) of the machine (1).

2. The motion assembly (14) comprises: - first guiding means (15) associated with said base frame (7) and extending along said working direction (W); A machine (1) according to claim 1, characterised by the fact that it comprises a first carriage (16) associated in a sliding manner with said first guiding means (15) and supporting said first holding means (8).

3. The movement unit (18) comprises: - second guiding means (19) associated with said base frame (7) and extending along said working direction (W); A machine (1) according to claim 1 or 2, characterised by the fact that it comprises a second carriage (20) associated in sliding manner with said second guiding means (19) and supporting at least said heating plate (17).

4. A machine (1) according to any one of claims 1 to 3, characterised by the fact that the electric actuator (21) is mounted on one of either the first carriage (16) or the second carriage (20) and that the synchronization mechanism (22) comprises at least one connecting arm (23) associated with the first carriage (16) and with the second carriage (20), the actuation of the electric actuator (21) causing, by means of the connecting arm (23), a capture of the other of either the first carriage (16) or the second carriage (20) along the working direction (W).

5. Machine (1) according to any one of the preceding claims, characterised by the fact that said articulated arm (23) is rotatably associated with said base frame (7) about a substantially vertical hinge axis (A).

6. The connecting arm (23) is - at least one hinge point (27) to said base frame (7); at least one first connection point (28) to said first carriage (16); at least one second connection point (29) to said second carriage (20), Machine (1) according to any one of the preceding claims, characterised by the fact that said second connection point (29) is located between said hinge point (27) and said first connection point (28).

7. The machine (1) according to any one of claims 1 to 6, characterized by the fact that the connecting arm (23) extends along a deployment direction (S) and that the points (27, 28, 29) are arranged in alignment with one another along said deployment direction (S).

8. 8. The machine (1) according to any one of claims 1 to 7, characterized by the fact that the areas to be welded (6) of the first forming element (4) and of the second forming element (5) lie respectively on a first working plane (P1) and on a second working plane (P2), substantially parallel to each other, and the heating plate (17) lies on a reference plane (B) substantially parallel to the working planes (P1, P2), and the ratio of the distance (D3) between the first connection point (28) and the hinge point (27) to the distance (D4) between the second connection point (29) and the hinge point (27) substantially corresponds to the ratio of the distance (D1) between the working planes (P1, P2) and the distance (D2) between the reference plane (B) and the second working plane (P2).

9. The machine (1) according to any one of claims 1 to 8, characterized by the fact that said synchronization mechanism (22) comprises a first pivot (30) associated with said first connection point (28) and by the fact that said first carriage (16) comprises a first guide (31) supporting said first pivot (30) in a sliding manner and extending transversely to said working direction (W).

10. The machine (1) according to any one of claims 1 to 9, characterized by the fact that the synchronization mechanism (22) comprises a second pivot (32) associated with the second connection point (29) and by the fact that the second carriage (20) comprises a second guide (33) which supports in a sliding manner the second pivot (32) and extends transversely to the working direction (W).

11. The machine (1) according to any one of claims 1 to 10, characterized by the fact that at least one of the first pivot (30) or the second pivot (32) is rotatably associated with the linking arm (23) about an associated axis of rotation (R1, R2) substantially parallel to the hinge axis (A).

12. Machine (1) according to any one of claims 1 to 11, characterized by the fact that the welding device (3) comprises removal means (41) adapted to remove portions of the plastic material from the areas to be welded (6), and a tool assembly (42) is provided supporting a pair of working tools (43) movably rotatable about associated rotation axes and positionable between at least one rear position moving away from the shaping elements (4, 5), a first working position positioned between the areas to be welded (6), the working tools (43) facing the respective areas to be welded (6), and a second working position in which the working tools (43) come into contact with the areas to be welded (6) in order to remove the plastic material.

13. A machine (1) according to any one of claims 1 to 12, characterised by the fact that, between the first and second working positions, the tool assembly (42) is movable along the working direction (W) and by the fact that the removal means (41) are mounted on the second carriage (20).

14. Machine (1) according to any one of the preceding claims, characterised by the fact that in said first working position, said tool assembly (42) lies above said reference plane (B).

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