Plant for the thermal treatment of artifacts

Abstract

Plant (1) for the thermal treatment of a plurality of artifacts, comprising a longitudinal casing (2), a convection tunnel furnace (3) positioned longitudinally within the casing (2), a plurality of stackable trays (4) designed to accommodate said artifacts, where said casing (2) features at least one first vertical longitudinal side (8); said furnace (3) having an entry end (11) and an exit end (12) for said stacks of said stackable trays (4); said plant (1) comprising a first conveyor (5) configured and arranged for the transport of at least one row of stacks of said stackable trays (4) through said furnace (3) from a loading position (6) to an unloading position (7); said plant (1) further comprising a second conveyor (13) configured and arranged for the return transport of said stackable trays (4) from a loading position (14) to an unloading position (15) of said stacks of said stackable trays (4), said plant (1) including handling means (16) for moving said stackable trays (4) from said unloading position (15) of said second conveyor (13) to said loading position (6) of said first conveyor (5) and for moving them from said unloading position (7) of said first conveyor (5) to said loading position (14) of said second conveyor (13); where said second conveyor (13) is located externally and facing said vertical longitudinal side (8) of said casing (2); said first conveyor (5) and said second conveyor (13) having longitudinal advancement axes (L1, L2) that are parallel and oppositely advancing; where said stackable trays (4) have a major axis (Y) and a minor axis (X); where said handling means (16) include multi-axis robots, characterized in that said handling means (16) are located at the head of said loading position (6) and said unloading position (7) of said first conveyor (5), said multi-axis robots being programmed to execute a displacement trajectory of said stackable trays (4) between said first conveyor (5) and said second conveyor (13) and vice versa, said trajectory including at least one vertical upward translational component, at least one horizontal translational component, and at least one vertical downward translational component; and said multi-axis robots being programmed to arrange said stackable trays (4) on said first conveyor (5) with their major axis (Y) transverse to said longitudinal advancement axis (L1) of said first conveyor (5), and to arrange said stackable trays (4) on said second conveyor (13) with their major axis (Y) transverse to said longitudinal advancement axis (L2) of said second conveyor (13).

Description

[0001] The present invention relates to a plant for the thermal treatment of artifacts.

[0002] Thermal treatment plants for artifacts have long been available on the market, typically intended for small semi-finished products originating from previous mechanical processing stations, downstream of which thermal treatments are required to complete and consolidate the specific properties and characteristics demanded by the finished product.

[0003] Known thermal treatment plants for artifacts comprise a tunnel furnace through which the artifacts, placed on stackable trays, move along conveyor means.

[0004] Systems for loading and unloading the artifacts onto the trays are known, as well as systems for loading and unloading the individual trays into stacks, and systems for loading and unloading the stacks of trays onto the conveyors, respectively at the furnace inlet and at the furnace outlet for the return path.

[0005] The patent application for industrial invention IT 102024000006625, filed by the same applicant, describes a plant for the thermal treatment of artifacts.

[0006] Problems are known to arise due to the excessive load density of the artifacts on the stackable trays, in the pursuit of greater productivity, which however compromises the quality of the uniform thermal treatment of the artifacts because of the different mass subsequently introduced into the furnace under the same operating parameters.

[0007] Problems are also known to result from the different characteristics of individual artifacts subsequently loaded onto the stackable trays.

[0008] Problems are also known to result from the emptying of the stackable trays from the furnace at the end of daily operations, when the different characteristics of the conveyor means and / or the different positioning and / or orientation of the stackable trays thereon prevent their complete transfer onto the return conveyor, thereby compromising the treatment quality of the artifacts not transferred from the furnace.

[0009] There is therefore a need to overcome these drawbacks found in known types of thermal treatment plants for artifacts.

[0010] Accordingly, there is a need to improve the overall structure of a plant for the thermal treatment of artifactss.

[0011] The technical aim of the present invention is therefore to provide a plant capable of eliminating the technical drawbacks of the known art.

[0012] Within the scope of this technical task, one object of the invention is to provide a plant for the thermal treatment of artifacts that ensures a constant arrangement of the artifacts on the stackable trays, independent of differing characteristics and / or dimensions of the individual artifacts. Another object of the invention is to provide a plant for the thermal treatment of artifacts that allows identical thermal treatment to be carried out even on different types of artifacts.

[0013] A further object of the invention is to provide a plant for the thermal treatment of artifacts that allows complete emptying of the furnace during work pauses.

[0014] The technical aim, as well as these and other objects, are achieved according to the present invention by providing a plant for the thermal treatment of a plurality of artifacts, comprising a longitudinal casing, a convection tunnel furnace positioned longitudinally within the casing, a plurality of stackable trays designed to accommodate said artifacts, where said casing features at least one first vertical longitudinal side; said furnace having an entry end and an exit end for said stacks of said stackable trays; said plant comprising a first conveyor configured and arranged for the transport of at least one row of stacks of said stackable trays through said furnace from a loading position to an unloading position; said plant further comprising a second conveyor configured and arranged for the return transport of said stackable trays from a loading position to an unloading position of said stacks of said stackable trays, said plant including handling means for moving said stackable trays from said unloading position of said second conveyor to said loading position of said first conveyor and for moving them from said unloading position of said first conveyor to said loading position of said second conveyor, where said second conveyor is located externally and facing said vertical longitudinal side of said casing, said first conveyor and said second conveyor having longitudinal advancement axes that are parallel and oppositely advancing; where said stackable trays have a major axis and a minor axis; where said handling means include multi-axis robots, characterized in that said handling means are located at the head of said loading position and said unloading position of said first conveyor, said multi-axis robots being programmed to execute a displacement trajectory of said stackable trays between said first conveyor and said second conveyor and vice versa, said trajectory including at least one vertical upward translational component, at least one horizontal translational component, and at least one vertical downward translational component; and said multi-axis robots being programmed to arrange said stackable trays on said first conveyor with their major axis transverse to said longitudinal advancement axis of said first conveyor, and to arrange said stackable trays on said second conveyor with their major axis transverse to said longitudinal advancement axis of said second conveyor.

[0015] In a preferred embodiment, said trays are stacked with their major axis inclined at the same angle with respect to the longitudinal advancement axis of said first conveyor and said second conveyor. In a preferred embodiment, the angle is equal to 90°.

[0016] In a preferred embodiment, the first and second conveyors operate with step-by-step advancement. Other features of the present invention are furthermore defined in the dependent claims. Additional features and advantages of the invention will become more apparent from the description of a preferred but non-exclusive embodiment of the plant according to the invention, illustrated by way of example and without limitation in the accompanying drawings, in which: Figure 1 shows a side view of the plant as a whole; Figure 2 shows a top view of the plant as a whole; Figure 3A shows a top view of the plant with some elements removed for greater clarity; Figure 3B shows a schematic vertical section of the transport line, with some elements omitted for clarity; Figure 4 shows a schematic vertical section of the furnace of the plant; Figure 5 shows a schematic plan view of the stackable trays; Figure 6 shows a detailed front view and an AA section of the hot air diffusers only; Figures 7A, 7B, and 7C show a schematic sequence of tray insertion into the furnace; Figures 8A, 8B, and 8C show a schematic sequence of tray extraction from the furnace.

[0017] With reference to the figures mentioned, there is shown a plant for the thermal treatment of artifacts according to the invention, generally indicated by reference numeral 1.

[0018] The plant 1 for the thermal treatment of artifacts comprises a longitudinal casing 2, a convection tunnel furnace 3 arranged longitudinally within the casing 2, and a plurality of stackable trays 4 in which the artifacts can be housed.

[0019] The furnace 3 has, in a known manner, a circuit for the generation and forced circulation of heated air to carry out the thermal treatment of the artifacts.

[0020] Typically, the artifacts subjected to thermal treatment comprise friction materials, such as brake pads.

[0021] The plant 1 includes a first conveyor 5, configured and arranged to transport at least one row of stacks of stackable trays 4 through the furnace 3, from a loading position 6 to an unloading position 7 of the first conveyor 5.

[0022] The furnace 3 has an inlet end 11 and an outlet end 12 for the stacks of stackable trays 4. The first conveyor 5 passes through a first and a second waiting station 22, 23.

[0023] The first waiting station 22 is arranged for the temporary positioning of the stackable trays 4 loaded with the artifacts to be treated and is located between the loading position 6 of the first conveyor 5 and the inlet end 11 of the furnace 3.

[0024] The second waiting station 23 is arranged for the temporary positioning of the stackable trays 4 loaded with treated artifacts and is located between the outlet end 12 of the furnace 3 and the unloading position 7 of the first conveyor 5.

[0025] The plant 1 comprises a second conveyor 13, configured for the return transport of the stackable trays 4 from a loading position 14 to an unloading position 15 of the second conveyor 13 for the stacks of stackable trays 4.

[0026] The casing 2 has at least one first longitudinal vertical side 8; typically, the second conveyor 13 is positioned externally to and facing said longitudinal vertical side 8.

[0027] The first and second conveyors 5, 13 are typically endless chain belts, horizontal, parallel, and straight, and they operate with step-by-step advancement.

[0028] The first conveyor 5 and the second conveyor 13 have longitudinal advancement axes L1 and L2, respectively, which are parallel and have opposite advancement directions.

[0029] In different embodiments, the first and second conveyors 5, 13 may be coplanar or arranged on offset planes.

[0030] In the embodiment shown in the figures, where they are on offset planes, the second conveyor 13 typically lies on a plane lower than that of the first conveyor 5.

[0031] The plant 1 includes at least two handling means 16 for the stackable trays 4, for transferring them from the unloading position 15 of the second conveyor 13 to the loading position 6 of the first conveyor 5, and from the unloading position 7 of the first conveyor 5 to the loading position 14 of the second conveyor 13.

[0032] According to the present invention, the handling means 16 are typically located at the head of the loading position 6 and the unloading position 7 of the first conveyor 5.

[0033] In a preferred embodiment, secondary means are provided for introducing the stacks of stackable trays 4 into the furnace 3, comprising first reversible means for engaging the individual stacks of trays 4 for step-by-step differential advancement of each stack from the loading station 6 to the first waiting station 22, and from the first waiting station 22 into the furnace 3, and secondary means are provided for extracting the stacks of stackable trays 4 from the furnace 3, comprising second reversible means for engaging the individual stacks of trays 4 for step-by-step differential advancement of each stack from the furnace 3 to the second waiting station 23, and from the second waiting station 23 to the unloading station 7.

[0034] Typically, in a preferred embodiment, the first and second reversible means comprise a mechanical actuator 100 with hinged linear movement, alternately engaged or released depending on the direction of linear advancement.

[0035] For example, the mechanical actuator 100 may consist of a rotatable blade 101 driven by a chain 110, moving back and forth linearly along the advancement direction of the first conveyor 5. The rotatable blade 101 has an end stop where it assumes a vertical position, and it normally maintains this vertical position due to return means 102, typically gravity-based means. When the blade 101 encounters a stack of trays 4, depending on the direction of linear movement, it is either not free to rotate to drag the stack or is free to rotate to pass beneath the stack of trays. Specifically, when free to rotate, the blade 101 is pushed down by the stack of trays 4 until it assumes a horizontal position, allowing it to pass under the stack of trays.

[0036] To prevent sliding of the stack of trays 4 along the first conveyor 5, a series of idle rollers is preferably provided along the tray dragging path (not shown in the drawings for simplicity), which slightly lift the stack of trays 4 relative to the support plane of the first conveyor 5.

[0037] Figures 7A, 7B, 7C and 8A, 8B, 8C schematically show, respectively, the sequences of tray insertion into and extraction from the furnace.

[0038] In Figure 7 A a first phase of introducing the stacks of trays 4 into the oven 3 is shown: the stacks of trays 4 are on the first conveyor 5; the conveyor 5 has advanced the stack 4 / 0 by a step equal to X inside the oven 3 to station D and has freed station C, the first station inside the oven 3; the blade 101 is in the thrust position dragged in advance in the direction L1 by the chain 110, is engaged with the stack of trays 4 / 1 which is located in station B at the first waiting position 22 and pushes it to station C inside the furnace 3, with a path equal to Y; at station A at the loading position 6 the handling means 16 continue with the loading of the stackable trays 4 / 2 and the loading of the artefacts to be treated.

[0039] In Figure 7B, a second phase of introducing the stacks of trays 4 into the oven 3 is shown: the stack of trays 4 / 1 is located at station C inside the oven 3 near stack 4 / 0; chain 110 reverses its direction with respect to L1, from forward movement to retraction; paddle 101 reverses its path and positions itself in the pushing position on stack of trays 4 / 2 at station A at loading position 6; to allow paddle 101 to pass underneath stack 4 / 2, paddle 101 deactivates the return means 102, which are reactivated after passing beneath stack 4 / 2 and return paddle 101 to the vertical pushing position; the return path is equal to 2Y.

[0040] In Figure 7C, a third phase of introducing the stacks of trays 4 into oven 3 is shown: chain 110 resumes forward movement in direction L1; stack 4 / 2 is engaged and pushed by paddle 101 from station A at loading position 6 to station B at the first waiting position 22; the pushing path is equal to Y; the stack of trays 4 / 1 at station C is waiting for conveyor 5 of oven 3 to advance by one step, thereby freeing station C so that it can receive stack of trays 4 / 2.

[0041] Figure 8A schematically shows a first phase of extracting the stacks of trays 4 from the oven 3: the handling means 16 have completed the unloading of the artefacts and of the stack of stackable trays 4 / N at station H at the discharge position 7, which is now free; the blade 101 is actuated by the chain 120 moving forward in direction L1, is in the pushing position engaged with the stack of trays 4 / 0 located at station G at the second waiting position 23 outside the oven 3, and pushes it to station H at the discharge position 7; the pushing path is equal to Y.

[0042] In Figure 8B a second phase of extracting the stacks of trays 4 from the oven 3 is shown: after pushing the stack 4 / 0 from station G to station H, the chain 120 reverses its direction with respect to L1, from forward to backward movement; the blade 101 positions itself in the pushing position on the stack 4 / 1 at station F inside the oven 3; to allow the blade 101 to pass underneath the stack 4 / 1, the blade 101 deactivates the return means 102, which are reactivated after passing under the stack 4 / 1 and return the blade 101 to the vertical pushing position; the return path is equal to Y; the handling means 16 unload the artefacts and the stack of stackable trays 4 / 0 at station H at the discharge position 7.

[0043] Figure 8C schematically shows a third phase of extracting the stacks of trays 4 from the oven 3: the chain 120 moves forward in the direction L1; the blade 101 is engaged with the stack of trays 4 / 1 and moves it from station F inside the oven 3 to station G at the second waiting position 23 outside the oven 3; the forward path is equal to Y; the handling means 16 unload the artefacts and the stack of stackable trays 4 / 0 at station H at the discharge position 7.

[0044] The stackable trays 4, typically rectangular, have at least two pairs of spacers 41 and 42 projecting from the two longer sides, in position that can be also asymmetric between the front and rear sides with respect to the advancement direction of the first and second conveyors 5, 13, where the asymmetry makes it possible to bring closer and reduce the clearances between the stacks of stackable trays 4 on the first conveyor 5 and the second conveyor 13.

[0045] The stackable trays 4 have a major axis Y, typically parallel to the longer side, and a minor axis X, perpendicular to the axis Y.

[0046] Conveniently, the handling means 16 comprise multi-axis robots.

[0047] These handling means 16 are typically programmed to divide each stackable tray 4 into a loading matrix, i.e., a plurality of virtual cells defined by axial coordinates of equal size, for depositing and holding individual artifacts, independently of their shape and size.

[0048] Conveniently, the virtual loading cells are dimensioned to contain the largest artifacts.

[0049] Advantageously, the constant plurality of loading cells on each individual tray 4, and / or on the plurality of trays 4 stacked in the various piles passing through the furnace 3 on the conveyor 5, ensures consistent thermal treatment quality under identical operating conditions of the furnace 3. The multi-axis robots are programmed to execute a movement trajectory of the stackable trays 4 between the first conveyor 5 and the second conveyor 13, and vice versa.

[0050] The movement trajectory of the stackable trays 4 comprises at least one ascending vertical translational component, one horizontal translational component, and one descending vertical translational component.

[0051] Conveniently and advantageously, the multi-axis robots are programmed to position the stackable trays 4 on the first conveyor 5 with their major axis Y transverse to the longitudinal advancement axis L1 of the first conveyor 5.

[0052] Conveniently and advantageously, the multi-axis robots are also programmed to position the stackable trays 4 on the second conveyor 13 with their major axis Y transverse to the longitudinal advancement axis L2 of the second conveyor 13.

[0053] In a preferred embodiment, the multi-axis robots are programmed to position the stackable trays 4 on the first conveyor 5 with their major axis Y inclined at an angle δ with respect to the longitudinal advancement axis L1 of the first conveyor 5, and to position the stackable trays 4 on the second conveyor 13 with the major axis Y inclined at the same angle δ with respect to the longitudinal advancement axis L2 of the second conveyor 13.

[0054] In a preferred, typical, and advantageous embodiment, the angle δ is equal to 90°.

[0055] The plant 1 comprises at least one or more first conveyor belts 17 for feeding the artifacts to be treated to the loading position 6 of the first conveyor 5, and at least one or more second conveyor belts 18 for removing the treated artifacts from the unloading position 7 of the first conveyor 5. The handling means 16 are configured to move, in addition to the trays 4, the artifacts to be treated from the first conveyor belts 17 to the stackable trays 4 at the loading position 6 of the first conveyor 5, and the treated artifacts from the stackable trays 4 at the unloading position 7 of the first conveyor 5 to the second conveyor belts 18.

[0056] In some preferred embodiments, the plant 1 comprises at least two or more first conveyor belts 17 for feeding at least two or more different types of artifacts to be treated.

[0057] Appropriately, the plant also includes at least two or more second conveyor belts 18 for removing the at least two or more different types of artifacts to be treated.

[0058] Preferably, each of said first and second conveyor belts 17, 18 is configured to transport one or more specific types of artifacts, which are suitably recognized by the handling means 16, at least in the quantity necessary to fill the loading matrix of at least one single stackable tray.

[0059] The handling means 16 pick up the artifacts to be treated, belonging to at least two or more different types, from the at least two or more first conveyor belts, typically 17', 17", 17‴, and arrange them by type on the same stackable tray 4 or on one or more stackable trays 4.

[0060] Similarly and consequently, the handling means 16 sort the at least two or more different types of treated artifacts from the same stackable tray 4 or from one or more stackable trays 4 and place them, by type, onto the at least two or more second conveyor belts, typically 18', 18", 18"'.

[0061] Advantageously, the types of artifacts on the individual first (17', 17", 17‴) and second (18', 18", 18"') conveyor belts may also not differ from one another: the handling means 16 simply recognize the type of article, pick it up from a first conveyor belt 17, and return it to the corresponding second conveyor belt 18.

[0062] Thus, advantageously and appropriately, both at the inlet and the outlet of the plant according to the present invention, each first conveyor belt 17 for feeding and each second conveyor belt 18 for removing carries a single type of artifact in the quantity necessary to fill the loading matrix of at least one single stackable tray 4.

[0063] As shown in Figure 4, the convection tunnel furnace 3 of the present plant for the thermal treatment of artifacts comprises a forced hot air circulation circuit through the furnace 3, a first longitudinal vertical side wall 3a equipped with hot air inlet openings, and a second longitudinal vertical side wall 3b equipped with hot air outlet openings.

[0064] The forced hot air circulation circuit includes a downward duct 6 for hot air along the first longitudinal vertical side wall 3a, where the hot air is horizontally diffused beneath the stacks of stackable trays 4 through a plurality of vertically superimposed horizontal diffusers 20.

[0065] Advantageously, according to the present invention, the horizontal diffusers 20 of the plurality shown in Figure 6 have identical geometric dimensional characteristics. Appropriately, the emission velocity of the hot air through the vertically superimposed horizontal diffusers 20 is advantageously maintained constant by a tapering of the vertical section of the terminal portion 6A of the downward duct 6, located at and behind said horizontal diffusers 20. The emission velocity of the hot air through the vertically superimposed horizontal diffusers 20 is set and maintained between 15.0 and 25.0 m / s, preferably between 18.0 and 22.0 m / s.

[0066] The operation of the plant 1 according to the invention is evident from what has been described and illustrated, and in particular is substantially as follows.

[0067] Initially, the stackable trays 4 are located at the unloading position 15 of the second conveyor 13. The artifacts to be treated arrive at the plant 1 via one or more first conveyor belts 17. In particular, if in one embodiment the artifacts are of two or more different types, the artifacts arrive at plant 1 via two or more first conveyor belts 17, each conveyor belt carrying one or more specific types of artifacts, each type of artifacts in at least the quantity required to fill the loading matrix of at least one single stackable tray 4.

[0068] The handling means 16 move a first stackable tray 4 from the unloading position 15 of the second conveyor 13 to the loading position 6 of the first conveyor 5.

[0069] The handling means 16 place the tray 4 on the first conveyor 5 with its major axis Y transverse, and in particular inclined at an angle δ relative to the longitudinal advancement axis L1 of the first conveyor 5.

[0070] Once the first stackable tray 4 is positioned, the handling means 16 transfer the artifacts from the first conveyor belts 17 to the first tray 4, placing each artifact in a specific virtual cell of the loading matrix programmed by the handling means 16, until the entire matrix of the tray 4 is filled with artifacts of the same type.

[0071] The handling means 16 then move a second stackable tray 4 from the unloading position 15 of the second conveyor 13 to the loading position 6 of the first conveyor 5, stacking it on the first tray 4 and maintaining the same transverse orientation and angle δ.

[0072] The handling means 16 then transfer the artifacts from the first conveyor belts 17 to the second tray 4, filling its virtual loading matrix.

[0073] This process is repeated iteratively until a complete stack of trays 4 loaded with artifacts to be treated is formed.

[0074] The stackable trays 4 are then transferred by the first conveyor 5 to the first waiting station 22, where they wait to enter the furnace 3.

[0075] Afterwards, the stackable trays 4 pass through the inlet end 11 of the furnace 3 and enter into the furnace 3, still carried by the first conveyor 5.

[0076] Inside the furnace 3, the artifacts on the trays 4 undergo the thermal treatment, and once completed, they exit the furnace through the outlet end 12 of the furnace 3, still carried by the first conveyor 5.

[0077] After leaving the furnace 3, the trays 4 remain for a period at the second waiting station 23, allowing initial cooling of the artifacts before their removal.

[0078] The trays 4, still transported by the first conveyor 5, then reach the unloading position 7.

[0079] At this position, the handling means 16 remove the treated artifacts from the top tray 4 of the loaded stack and place them on the second conveyor belts 18.

[0080] Particularly, if the artifacts of the stack of trays 4 are of two or more different types, the handling means recognize their loading cell within the virtual loading matrix of the individual tray 4, and place them on two or more second conveyor belts 18, where each different type of artifact is placed on a different conveyor belt.

[0081] When all artifacts have been removed from the upper tray of the stack, the handling means 16 transfer the upper tray of the stack from the unloading position 7 of the first conveyor 5 to the loading position 14 of the second conveyor 13, where the tray becomes the bottom tray of a new stack of empty trays.

[0082] Advantageously and appropriately, the handling means 16 place the stackable tray 4 on the second conveyor 13 with the major axis Y transverse, in particular inclined at the same angle δ relative to the longitudinal advancement axis L2 of the second conveyor 13.

[0083] The handling means 16 then remove the treated artifacts from the second-to-last tray and place them on the second conveyor belts 18.

[0084] When all the artifacts have been removed from the second-to-last tray, the handling means 16 move the second-to-last tray from the unloading position 7 of the first conveyor 5 to the loading position 14 of the second conveyor 13, keeping it transverse and, in particular, maintaining the angle δ.

[0085] The process is repeated iteratively until all the stackable trays 4 have been emptied of the artefacts, and until all the trays of the tray stack have been moved to the loading position 14 of the second conveyor 13.

[0086] The second conveyor belts 18 then move the treated artifacts away from the plant 1.

[0087] The stackable trays 4, instead, are transported by the second conveyor 13 from the loading position 14 to the unloading position 15.

[0088] Once they have reached the unloading position 15 of the second conveyor 13, the stackable trays 4 are ready to begin the cycle again.

[0089] Advantageously, according to the present invention, the trays 4 and stacks of trays are positioned by the handling means 16 on both the first 5 and second 13 conveyors always transversely and in particular at the same angle δ, defined by the major axis Y of the stackable tray 4 and by the longitudinal advancement axes of the first conveyor 5 and the second conveyor 13, respectively L1 and L2.

[0090] The transverse maintenance and, in particular, the maintenance of the angle δ between the major axis Y and the longitudinal advancement axes L1 and L2 of the first conveyor 5 and the second conveyor 13 advantageously ensures the possibility of completely emptying the oven 3 when the daily activity and / or work shift ends, allowing all the stacks of stackable trays 4 loaded with artefacts being processed inside the oven on the first conveyor 5 to find space corresponding to the space occupied on the first conveyor 5, once the treated artefacts have been unloaded, on the second conveyor 13.

[0091] It has been practically observed that a plant for the heat treatment of a plurality of artefacts according to the invention is particularly advantageous in that it provides a plant in which the arrangement of the artefacts on the stackable trays is constant and not dependent on different characteristics and / or dimensions of the individual artefacts, thus ensuring an effective and consistent thermal treatment of the individual artefacts.

[0092] Another advantage of the invention is that of providing a plant for the thermal treatment of artifacts which allows identical thermal treatment of different types of artifacts.

[0093] A further advantage is that of providing a plant for the thermal treatment of artifacts that allows complete emptying of the furnace during work pauses.

[0094] The plant 1, as conceived, is susceptible to numerous modifications and variations, all of which fall within the scope of the inventive concept; furthermore, all details may be replaced by technically equivalent elements.

[0095] In practice, the materials used, as well as the dimensions, may vary depending on requirements and the state of the art.

Claims

1. Plant (1) for the thermal treatment of a plurality of artifacts, comprising a longitudinal casing (2), a convection tunnel furnace (3) positioned longitudinally within the casing (2), a plurality of stackable trays (4) designed to accommodate said artifacts, where said casing (2) features at least one first vertical longitudinal side (8); said furnace (3) having an entry end (11) and an exit end (12) for said stacks of said stackable trays (4); said plant (1) comprising a first conveyor (5) configured and arranged for the transport of at least one row of stacks of said stackable trays (4) through said furnace (3) from a loading position (6) to an unloading position (7); said plant (1) further comprising a second conveyor (13) configured and arranged for the return transport of said stackable trays (4) from a loading position (14) to an unloading position (15) of said stacks of said stackable trays (4), said plant (1) including handling means (16) for moving said stackable trays (4) from said unloading position (15) of said second conveyor (13) to said loading position (6) of said first conveyor (5) and for moving them from said unloading position (7) of said first conveyor (5) to said loading position (14) of said second conveyor (13); where said second conveyor (13) is located externally and facing said vertical longitudinal side (8) of said casing (2); said first conveyor (5) and said second conveyor (13) having longitudinal advancement axes (L1, L2) that are parallel and oppositely advancing; where said stackable trays (4) have a major axis (Y) and a minor axis (X); where said handling means (16) include multi-axis robots, characterized in that said handling means (16) are located at the head of said loading position (6) and said unloading position (7) of said first conveyor (5), said multi-axis robots being programmed to execute a displacement trajectory of said stackable trays (4) between said first conveyor (5) and said second conveyor (13) and vice versa, said trajectory including at least one vertical upward translational component, at least one horizontal translational component, and at least one vertical downward translational component; and said multi-axis robots being programmed to arrange said stackable trays (4) on said first conveyor (5) with their major axis (Y) transverse to said longitudinal advancement axis (L1) of said first conveyor (5), and to arrange said stackable trays (4) on said second conveyor (13) with their major axis (Y) transverse to said longitudinal advancement axis (L2) of said second conveyor (13).

2. Plant (1) for the thermal treatment of artifacts according to the preceding claim, characterized in that said multi-axis robots are programmed to arrange said stackable trays (4) on said first conveyor (5) with their major axis (Y) inclined at an angle (δ) relative to said longitudinal advancement axis (L1) of said first conveyor (5), and to arrange said stackable trays (4) on said second conveyor (13) with their major axis (Y) inclined at the same angle (δ) relative to said longitudinal advancement axis (L2) of said second conveyor (13).

3. Plant (1) for the thermal treatment of artifacts according to the preceding claim, characterized in that said angle (δ) is 90°.

4. Plant (1) for the thermal treatment of artifacts according to any preceding claim, characterized in that said handling means (16) are programmed to divide said stackable tray (4) into a virtual loading matrix, that is, into a plurality of virtual cells defined by axially uniform coordinates, for depositing and containing individual artifacts, independent of the shape and dimensions of said artifacts.

5. Plant (1) for the thermal treatment of artifacts according to any preceding claim, characterized in that said stackable trays (4) are rectangular in shape and feature at least two pairs of spacers (41) and (42) projecting at the two major sides, asymmetrically positioned between the front side and the rear side with respect to the advancement of said first conveyor (5) and said second conveyor (13).

6. Plant (1) for the thermal treatment of artifacts according to any preceding claim, characterized by including multiple first conveyor belts (17) for feeding multiple types of said artifacts to be treated to the loading position (6) of the first conveyor (5), and multiple second conveyor belts (18) for removing said multiple types of treated artifacts from the unloading position (7) of the first conveyor (5); said handling means (16) being configured to move said multiple types of artifacts to be treated from said first conveyor belts (17) to said stackable trays (4) in said loading position (6) of said first conveyor (5), and said multiple types of treated artifacts from said stackable trays (4) in said unloading position (7) of said first conveyor (5) to said second conveyor belts (18).

7. Plant (1) for the thermal treatment of artifacts, according to any preceding claim, where said convection tunnel furnace (3) includes a forced circulation circuit for hot air through the furnace (3); a first vertical longitudinal side (3a) equipped with hot air inlet openings, and a second vertical longitudinal side (3b) equipped with hot air outlet openings; where the forced circulation circuit for hot air includes a downward channeling (6) of hot air to the first vertical longitudinal side (3a) of the furnace (3), where the hot air is horizontally diffused beneath said stacks of said stackable trays (4) through a plurality of vertically superimposed horizontal diffusers (20), characterized in that said horizontal diffusers (20) of said plurality of diffusers have identical dimensional geometric characteristics and that the emission velocity of hot air through said vertically superimposed horizontal diffusers (20) is kept constant by a tapering of the vertical section of the terminal portion (6A) of said downward channeling (6) near said horizontal diffusers (20).

8. Plant (1) for the thermal treatment of artifacts, according to the preceding claim, characterized in that the emission velocity of hot air through said vertically superimposed horizontal diffusers (20) is arranged and maintained between 15.0 and 25.0 m / sec, preferably between 18.0 and 22.0 m / sec.

9. Plant (1) for the thermal treatment of artifacts according to any preceding claim, characterized in that said first conveyor (5) and said second conveyor (13) advance step-by-step.

10. Plant (1) for the thermal treatment of artifacts according to any preceding claim, characterized in that said first conveyor (5) and said second conveyor (13) are horizontal, parallel, and straight, and lie on two staggered planes, said second conveyor (13) lying on a plane lower than the plane on which said first conveyor (5) lies.

11. Plant (1) for the thermal treatment of artifacts, according to any preceding claim, characterized in that said artifacts are brake pads.

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