AU2023203224A1

AU2023203224A1 - Distribution unit for agricultural atomizer

Info

Publication number: AU2023203224A1
Application number: AU2023203224A
Authority: AU
Inventors: Alfredo Melloni
Original assignee: FIENI GIOVANNI Srl
Current assignee: FIENI GIOVANNI Srl
Priority date: 2022-05-27
Filing date: 2023-05-23
Publication date: 2023-12-14
Also published as: IT202200011174A1; ES2957420A1

Abstract

A distribution unit (1) for an agricultural atomizer, comprising at least one support structure (3) and at least one distributor element (2), associated with said support structure (3), and configured to direct a flow of an air mixture and a sprayed 5 treatment fluid towards the foliage of the plants or crops to be treated; the distributor element (2) comprises at least one fan (9), and nebulization means (23) of the treatment fluid to be mixed with the air flow generated by said fan (9). The unit (1) comprises at least one generator (30), which can be coupled to a heat engine of the atomizer; the at least one distributor element (2) comprises an electric 10 motor (10), on whose output axis (11) the fan (9) is keyed; an electric power supply system (32) is also provided which connects the generator (30) to the distributor element (2); the system (32) is configured to power the electric motor (10) at low voltage. 15 20 25 20 1/9 291 22 2 S/29 It 14 3 1 1 13 5 1414 29 2 13 13 292 5 I- 2 li 13 1 4 1 4 2 32-- -29 29 38 3610 FIG. 1

Description

1/9 291 2 22 S/29 It 14 3

11 13 5

1414

29

2

13 13 292

5 I- 2 li13 1

41 4 2 32-- -29 29 38

3610 FIG. 1

"DISTRIBUTION UNIT FOR AGRICULTURAL ATOMIZER". TECHNICAL FIELD OF THE INVENTION The present invention concerns a distribution unit for agricultural atomizer. More in detail, the present invention relates to a distribution unit for an agricultural atomizer with high efficiency and low environmental impact, avoiding product drift. PRIOR ART Currently, to carry out certain treatments, such as pesticide treatments or the like, on crops such as vineyards, fruit trees, or in any case on plants in general, machines called agricultural atomizers are used. As known, the latter can be of different types, mainly, but not only, in relation to the characteristics of the vehicle or locomotion system that allows them to move on the ground (that is, essentially along the rows of plants to be treated). Therefore, essentially, the atomizers carried, or towed, by a tractor, or self propelled (that is, equipped with their own locomotion system) are identified. In addition to the locomotion means or system, which, as mentioned, varies in relation to the specific type of machine considered, the atomizer usually includes, among its essential groups or components, a support frame, a tank intended to contain the fluid product to be distributed, a fluid transport circuit, with relative pump, and a ventilation unit, which nebulizes the fluid product and directs it to the plants to be treated. In more detail, the aforementioned ventilation unit typically comprises a fan and a system of nozzles, suitably positioned at the outlet surface of the air flow generated by the fan itself. The aforementioned nozzles, fed by the fluid transport circuit, pulverize/nebulize the product, and the latter is then directed onto the plants to be treated by means of the air flow generated by the fan. In some machines of the known type - especially those carried or towed - the fan can be operated by means of a mechanical transmission, connected to a heat engine, or to the power take-off of the tractor; optionally, the fan can also be coupled to a speed multiplier or reducer, associated with the aforementioned mechanical transmission. In other types of machines, the fan can be moved by means of a hydraulic/oleodynamic drive system, also connected to the tractor power take-off. Agricultural atomizers of the known type, and previously described, are not free from various drawbacks of various nature. A first drawback, which afflicts agricultural atomizers of the known type, concerns precisely the methods of actuation of the same. Indeed, both the actuations of the entirely mechanical type and those of the mechanical/hydraulic type require the construction of support frames having heavy and bulky, and consequently also expensive, structures. It is clear that this feature also has a negative impact on the atomizer drive and towing energy costs. In addition to the high management costs, the negative impact on the environment of solutions of this type is becoming increasingly less tolerable, since high fuel consumption causes high polluting emissions into the atmosphere. Another drawback, that afflicts this type of machine, concerns the lack of versatility of the same in adapting to different situations of distribution of the product on the crops. In fact, despite the various possibilities for regulating the flow of the fan, both in its air flow rate and in the direction in which the flow itself invests the plants to be treated, the same machine can prove to be perfectly effective in some situations, and can instead be lacking in other. These differences can be attributed, in many cases, to determining factors such as the overall size of the plants, their mutual positioning, the type and distribution of the foliage, and others. Due to the implementation of an ineffective treatment, more or less extensive areas can be observed in the foliage in which the product has not been deposited at all, or it has been deposited in an approximate way.

This can cause the uncontrolled spread of parasites or other plant pathologies, which can damage the cultivation and therefore the quality/quantity of the harvest. To overcome these problems, and therefore to improve the effectiveness of product distribution in relation to the characteristics of the specific application situation, in some known types of atomizers the fan can be associated with a sort of distributor duct, which can be shaped in such a way to direct the air flow in one or more fixed directions. For example, the aforesaid duct may comprise one or even two outlets configured and oriented so as to simultaneously direct the flow of the air-product mixture onto two facing parallel rows. However, even the atomizers that incorporate these last technical solutions are, in any case, scarcely effective in certain situations of use, such as those - just to name a few - in which the plants to be treated are quite vertically extended, or they have very thick and/or substantially irregular shape. AIMS OF THE INVENTION The technical aim of the present invention is to improve the state of the art in the field of agricultural atomizers. Within such technical aim, an object of the present invention is to provide a distribution unit for an agricultural atomizer which allows to overcome the aforementioned drawbacks. Another object of the present invention is to provide a distribution unit for an agricultural atomizer which allows to obtain a significant reduction in the operating consumption of the machine. Another object of the present invention is to provide a distribution unit for an agricultural atomizer which allows to reduce the weight and dimensions of the machine. A further object of the present invention is to develop a distribution unit for an agricultural atomizer which is more flexible and versatile, in the various conditions of use, than machines of the known type. Another object of the present invention is to manufacture a distribution unit for an agricultural atomizer which can be easily adjusted and adapted to application situations characterized by different features of the plants to be treated. Another object of the present invention is to devise a distribution unit for agricultural atomizers that is more effective than known solutions, in particular as regards the delivery of the product on the surface of the leaves of the plants to be treated. This aim and these objects are achieved by the distribution unit for agricultural atomizers according to the attached claim 1. The distribution unit comprises at least one support structure and at least one distributor element, associated with the support structure, and configured to direct a flow of a mixture of air and a nebulized treatment fluid towards the foliage of the plants or crops to be treated. The aforesaid distributor element comprises at least one fan and nebulization means for the treatment fluid, to be mixed with the air flow generated by the fan. The distribution unit comprises at least one generator, which can be coupled to a heat engine of the atomizer. Furthermore, the distributor element comprises an electric motor, on the output axis of which the fan is keyed; an electric power supply system is also provided which connects the generator to the aforesaid at least one distributor element; the system is configured to power the electric motor at low voltage. As better clarified below, the use of a low voltage power supply system of the distributor element makes it possible to achieve considerable advantages in terms of efficiency and operating/management costs of the agricultural atomizer. Furthermore, this solution is greatly advantageous in obtaining satisfactory atomizer performance under different and changing treatment situations. The dependent claims refer to preferred and advantageous embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The features of the invention will be better understood by any person skilled in the art from the following description and from the annexed tables of drawings, given as a non-limiting example, in which: Figure 1 is a schematic front view of the distribution unit for an agricultural atomizer according to the invention; Figure 2 is an electrical diagram of the distribution unit; Figure 3 is an exploded isometric view of one of the distributor elements of the distribution unit; Figure 4 is a front perspective view of one of the distribution elements of the distribution unit; Figure 5 is a rear perspective view of one of the distribution elements of the distribution unit; Figure 6 is a front view of the impeller of each of the distributor elements of the distribution unit; Figure 7 is a rear view of the impeller of Figure 6; Figure 8 is a front perspective view of the impeller of Figures 6, 7; Figure 9 is a side view of the impeller of Figures 6-8; Figures 10, 11, 12 are respective detailed perspective views, from different angles, of one of the blades of the impeller of Figures 6-9; Figure 13 is a further perspective view of the distribution unit for an agricultural atomizer according to the present invention. EMBODIMENTS OF THE INVENTION With reference to the attached Figure 1, a distribution unit for an agricultural atomizer according to the present invention is wholly indicated with 1. The distribution unit 1 according to the present invention can be installed on an agricultural atomizer of any type. For example, the agricultural atomizer, on which the distribution unit 1 can be installed, could be of the mounted, or towed, or self-propelled type, without limitations to the purposes of the present invention. The agricultural atomizer, on which the distribution unit 1 according to the invention can be installed, can comprise locomotion means (not shown in the figures), for movement on the ground.

Said locomotion means can be of any type; these means can vary in relation to the constructive and functional features of the machine. The atomizer can, furthermore, comprise at least one support frame, with which the aforementioned locomotion means are associated (or associable). The atomizer can also comprise at least one tank (not shown in the figures), intended to contain the fluid product to be distributed. The tank is associated, or can be associated, with the aforementioned support frame. The spray fluid can be of any type suitable for the application. Normally, in the most common applications, the treatment fluid is fed in the liquid phase; however, it could also be in a different phase, or in a mixture of different phases, without limiting the purposes of the present invention. Also, from the point of view of the chemical composition, the treatment fluid can evidently be any. In addition, the atomizer can comprise a transport circuit (not shown in the figures), of the fluid contained in the aforementioned tank, towards the distribution unit 1. The distribution unit 1 according to the invention comprises at least one distributor element 2. The at least one distributor element 2 is configured to direct a flow of a mixture of air and nebulized treatment fluid towards the foliage of the plants, or crops, to be treated. The distribution unit 1 can also comprise a support structure 3. The support structure 3 is configured to support the at least one distributor element 2 in the desired operating position. Furthermore, the support structure 3 is configured to be fixed/associated with the frame of the agricultural atomizer. The support structure 3 can have any shape and size, in relation to the specific use and/or application requirements. Furthermore, the support structure 3 can have a shape and/or configuration that can be changed/modified in relation to the specific needs of use and/or application.

For example, the support structure 3 can comprise at least one upright 4, or other similar structural/bearing element, to which the at least one distributor element 2 is fixed (or connected in an adjustable manner). In an embodiment of the invention of particular practical interest, the distribution unit 1 comprises a plurality of distribution elements 2. Furthermore, in this embodiment, the support structure 3 can comprise two or more uprights 4, or other similar structural/supporting elements. The two (or more) uprights 4 are each configured to support at least one respective distributor element 2 in the desired operating position. In the schematic representation of figure 1 (provided by way of non-limiting example only) the support structure 2 comprises two uprights 4 parallel, or substantially parallel, arranged vertically, or substantially vertically, with reference to the use configuration of the atomizer (and therefore also of distribution group 1). As illustrated in the aforementioned figure 1, three respective distributor elements 2 are fixed (or connected in an adjustable manner) to each of the uprights 4, superimposed on each other vertically, or substantially vertically (with reference to the configuration of use of the atomizer). Each of the distributor elements 2 can be connected to the respective upright 4 in an adjustable/orientable manner. Thanks to this arrangement, the direction of the flow of the air-fluid mixture emitted by each distributor element 2 can be independently selected and modified in relation to the different operating requirements. For example, in the embodiment schematically represented in the aforementioned figure 1, in each upright 4, the distributor elements 2 placed higher and lower are oriented with opposite inclinations, so as to obtain, overall, a substantially "fan" delivery of the air-fluid mixture; this expedient allows the aforementioned mixture to be dispensed on a more vertically extended and/or better distributed area of the foliage of the plants. It is clear that the orientation - with respect to its upright 4 - of each distributor element 2 can be modified at will, so as to obtain the delivery method of the air fluid mixture most suitable for the specific operating situation (for example, so as to obtain of delivery areas extended/developed along a certain preferred direction). According to one aspect of the invention, each distributor element 2 can be connected to the respective upright 4 by means of an articulated joint 5; as an alternative to the articulated joint, any other similar adjustable fastening device can be used, which allows the distributor element 2 to be positioned with the desired orientation with respect to the upright 4 itself. The joint 5, in addition to being articulated (or as an alternative to being articulated), can also be of the sliding type along the respective upright 4. This makes it possible to vary the height of each distributor element 2 with respect to the ground, and therefore also, if desired, the mutual distance between the distributor elements 2 along the respective uprights 4. The exploded perspective view of Figure 3 shows the main components of each distributor element 2 of the distribution unit 1 according to the present invention. The features of the distributor element 2 are described below. The following description can refer both to distribution units 1, according to the invention, comprising a single distributor element 2, and to distribution units 1 again according to the invention - comprising a plurality of distributor elements 2. The distributor element 2 comprises a central support 6. The central support 6 has a substantially cylindrical shape and comprises a through axial channel 7. Furthermore, the central support 6 comprises arms 8 (for example, four arms 8), fixed to its outer surface and arranged in a substantially radial manner. The distributor element 2 also comprises a fan 9, and an electric motor 10, on whose output axis l Ithe aforementioned fan 9 is keyed. The fan 9 and the electric motor 10 are mutually connected on opposite sides with respect to the central support 6; in more detail, the output axis 11 of the electric motor 10 passes through the axial channel 7, to engage in a respective seat 12 provided in the fan 9. The electric motor 10 can be fixed to the central support 6, for example, by screws.

The distributor element 2 also comprises a delivery duct 13 for the flow of the air fluid mixture generated by the fan 9. The delivery duct 13 is fixed to a casing 14 of the distributor element 2. The casing 14 has a substantially converging tubular shape, and is in turn fixed to the arms 8 of the central support 6. The casing 14 defines a sort of chamber which houses the fan 9. The casing 14, therefore, defines an air intake section 15 (with a larger surface) and an air delivery section 16 (with a smaller surface). The rear area of the distributor element 2 can be closed by a protective grate 17, which prevents the entry of foreign bodies; moreover, said rear area can be closed by a cap 18 which covers the electric motor 10. The distributor element 2 can also comprise, in correspondence with its rear area, a bracket 19 for fastening to the support structure 3 (for example, by means of an articulated/sliding joint 5). The delivery duct 13, formed by the geometry of the blades of the fan 9, is configured to act as a diffuser for the flow of the air-fluid mixture generated by the fan 9. In more detail, the dispensing duct 13 comprises a circular, or substantially circular, inlet section 20; the inlet section 20 is fixed to the delivery section 16 of the casing 14. Furthermore, the delivery duct 13 comprises an outlet section 21, having an elongated shape (in a transverse direction with respect to the flow direction of the air-fluid mixture). In more detail, the aforementioned outlet section 21 has a substantially elliptical, or substantially flattened elliptical shape, with two long sides which, for a certain length, are substantially straight and parallel. In one embodiment of the invention, the delivery duct 13 can comprise two separate portions 13a, 13b, coupled along two opposing joining lines 22. According to another aspect of the invention, the distributor element 2 comprises nebulization means 23 of the fluid to be mixed with the air flow.

In more detail, the aforesaid nebulization means comprise at least one supply pipe 23 of the fluid to be mixed with the air flow. The supply pipe 23 can therefore be connected to the fluid transport circuit of the atomizer. According to one aspect of the invention, this supply pipe 23 is housed inside the delivery duct 13; in more detail, the supply pipe 23 is interposed between the inlet section 20 and the outlet section 21 of the delivery duct 13. The supply pipe 23 is oriented according to the major axis of the outlet section 21 of the delivery duct 13 (substantially assimilating the shape of the cross section of the latter to an ellipse). The supply pipe 23 also comprises a plurality of nozzles 24 for atomizing/pulverizing the treatment fluid. The nozzles 24 can be arranged equidistant from each other along the external surface of the supply pipe 23, and they are placed in communication with the internal channel of the pipe 23 itself, which carries the fluid. According to another aspect of the invention, the supply pipe 23 has a curved or arched shape; moreover, the supply pipe 23 turns its convexity towards the outlet section 21 of the delivery duct 13. The fluid supply pipe 23 can be connected to the delivery duct 13; in more detail, the two opposite ends of the supply pipe 23 are locked/clamped between the two portions 13a, 13b of the delivery duct 13, at theirjoining lines 22. According to another aspect of the invention, the distributor element 2 can comprise a deflector 25 for the flow of the air-fluid mixture, positioned at the outlet section 21 of the delivery duct 13. The deflector 25 can be supported, for example, by a grate element 26, fixed to the inner surface of the dispensing duct 13; in particular, this fastening can be made in such a way that the deflector 25 itself is positioned exactly facing the fluid supply pipe 23. The deflector 25 can be fixed or movable/adjustable; for example, the deflector 25 can comprise a vertical laminar element 27 and two or more horizontal laminar elements 28, which cross with the aforementioned vertical laminar element 27. Figures 1, 4, 5 show schematically, in broken lines, and for illustrative purposes only, the shape of the jet 29 (flow) of air-fluid mixture emitted by each distributor element 2. In particular, Figure 1 also shows the overall effect deriving from the overlapping of the jets 29 emitted by several distributor elements 2 positioned one above the other. In fact, it has been experimentally observed that the air-fluid mixture jet 29 emitted by each distributor element 2 has a substantially divergent shape; in more detail, such jet 29 has a shape similar to that of a truncated cone, squashed at its lateral surface. As can be seen in Figure 1, by varying the position and inclination of each of the distributor elements 2 with respect to the respective uprights 4, it is possible to modify the shape and overall extension of the surface sprayed by the jets 29 of the individual distributor elements 2. The partial overlapping of the aforementioned jets 29 ensures that there are no areas of the foliage of the plants that are not sprayed appropriately. According to another aspect of the invention (and with particular reference to Figures 1, 2), the distribution unit 1 comprises a generator 30. The generator 30 is coupled/can be coupled to a heat engine of the atomizer (in particular, the heat engine of the locomotion means of the atomizer). In more detail - for example, in the case in which the distribution unit 1 is installed on an atomizer of the carried or towed type - the generator 30 can be coupled to the power take-off 31 of the tractor. The at least one distributor element 2 present in the distribution unit 1 is operatively connected to the generator 30 (in particular, if present in a number greater than one, all the distributor elements 2 of the unit 1 are operatively connected to the generator 30). As mentioned, the number of distributor elements 2 present in unit 1 can be any: for example, in the diagram of Figure 2, the distribution unit 1 comprises eight distributor elements 2. In more detail, the distribution unit 1 comprises an electric power supply system 32 which connects the generator 30 to at least one distributor element 2, or to the plurality of distributor elements 2 (illustrated schematically in Figure 2). According to another aspect of the invention, the electric motor 10 of the at least one distributor element 2 (or each electric motor 10 of each of the distributor elements 2) is a synchronous alternating current motor of the brushless type. The choice of this type of electric motor makes it possible to obtain numerous advantages in driving the fans 9 of the distributor units 2, including reduced size and weight, reduced noise, higher efficiency and therefore optimization of consumption, immediate availability of drive torque, better speed control, long life, very low maintenance, just to name a few. These advantageous aspects allow, in particular, to obtain a very precise control of the motion of each of the fans 9, even with very low speeds, so as to adapt the operation of the distribution unit 1 to different application situations. The system 32 comprises an AC/DC converter, or rectifier 33, connected to the output of the generator 30. The system 32 also comprises at least one DC/AC converter, or inverter 34, connected to the electric motor 10 of the at least one distributor element 2. In an embodiment of the invention of particular practical interest, in which the unit 1 comprises a plurality of distributor elements 2, the system 32 consequently comprises a plurality of DC/AC converters, or inverters 34 (i.e. as many as there are the distributor elements 2 of unit 1). The respective electric motors 10 of the distributor elements 2 are operatively connected and slaved to the inverters 34. A line 35, connected to the output of the rectifier 33, feeds the inverter 34 of the at least one electric motor 10; or, line 35 supplies, in parallel, the plurality of inverters 34 of the electric motors 10. According to one aspect of the invention, the system 32 is configured to power the electric motor 10 of the at least one distributor element 2 (or the electric motors 10 of the plurality of distributor elements 2) at low voltage. More in detail, in a preferred embodiment of the invention, the system 32 is configured to supply the electric motor 10 of the at least one distributor element 2 (or, the electric motors 10 of the plurality of distributor elements 2) with a voltage of 48 V (low voltage). According to another aspect of the invention, the system 32 comprises at least one rechargeable battery 36. The rechargeable battery 36 is connected in parallel to the supply line 35 of the distributor elements 2. The system 32 also comprises a battery management system (BMS) 37, to which the rechargeable battery 36 is operatively connected; the recharging process of the latter is therefore supervised by the aforementioned management system 37. The choice of the low voltage power supply of the distributor elements 2 is optimal for the use of the rechargeable battery 36. In fact, in some operating situations, the rechargeable battery 36 of the system 32 can supply sufficient energy to allow the distribution unit 1 to operate in complete autonomy (at least for a given period of time). Furthermore, the choice of low voltage makes it possible to obtain various other important advantages from the point of view of the safety and efficiency of the system 32. According to yet another aspect of the invention, the system 32 comprises at least one control unit 38 for controlling and managing the operation of the distributor elements 2 (or of the single distributor element 2). The inverters 34 of the distributor elements 2 (or of the single distributor element 2), as well as the management system (BMS) 37 of the rechargeable battery 36 are operatively connected to the control unit 38. In one embodiment of the invention, the system 32 comprises a bus 39 of the CAN type (Controller Area Network) which operatively connects the inverters 34 (or the single inverter 34) and the management system (BMS) 37 to the control unit 38; this type of bus 39 is particularly advantageous, among other things, due to its high immunity to disturbances. The control unit 38 can, in turn, be operatively connected to a user interface of the distribution unit 1 and/or to a user interface of the atomizer (not shown in the figures). Through the aforementioned user interface, the assigned operator can modify at will, and in relation to the different treatment needs, the speed of each of the fans 9 of the distributor elements 2 (or of the fan 9 of the single distributor element 2). It is therefore possible to regulate, in a very accurate and extremely flexible way, the delivery flow of the air-fluid mixture of the single distributor element 2, or of each distributor element 2 of the distribution unit 1. Figure 13 is a further, more detailed perspective view of the distribution unit 1 according to the present invention, which facilitates the understanding of the functioning of the unit 1 itself. In the version of the invention represented in this Figure 13, the distribution unit 1 comprises four distribution elements 2. With respect to what has already been described and illustrated above, with particular reference to Figures 1 and 2, the following further aspects are underlined. The generator 30 comprises a flanged multiplier 301, which can be connected to the power take-off 31 of the tractor (preferably via a cardan shaft). The power take-off 31 of the tractor can rotate at a maximum of 540 rpm. In practice it has been verified that, at a minimum of 330 rpm of the power take-off 31, the generator 30 has sufficient energy to feed all the distributor elements 2 present in unit 1, with a voltage of 48 V (low voltage). Unit 1 comprises an electrical box 381, inside which the control unit 38 is housed. The electrical box 381 includes an actuation button 382, operatively connected to the control unit 38. Inside the electrical box 381 there are various electronic components necessary for the correct functioning of unit 1, such as for example a converter, fuses, relays, IoT module, terminals, etc.. Furthermore, unit 1 comprises a display 383, this too operatively connected to the control unit 38. The control unit 38 includes a program which allows the operator, via the display 383, to control the activation and rotation speed of the electric motors 10 of each of the distributor elements 2. The display 383 turns on by pressing the activation button 382. The display 383 is powered by its own battery, which allows it to operate even when it is not directly powered by the generator 30. From the control unit 38, as already mentioned, the cables 391 of the bus 39 depart, connected in turn to the inverters 34 of the distributor elements 2, to send the latter the appropriate command signals. Thanks to the control configuration of unit 1 according to the invention, it is possible to operate even just one distributor element 2, leaving the others off. It should also be underlined that, in some versions of the invention, the unit 1 can be powered directly by the tractor, if the latter is electric or if it has its own generator. Another important aspect of the present invention consists of the characteristics of the fan 9 of each of the distributor elements 2 (or of the single distributor element 2). In more detail, the fan 9 comprises a hub 40. The hub 40 is configured to be keyed to the output axis 11 of the electric motor 10 of the respective distributor element 2 (for example, by means of a member such as a keying device, or the like). The hub 40 comprises a lateral surface 41; the lateral surface 41 is cylindrical, or substantially cylindrical. The fan 9 also comprises a plurality of blades 42; the blades 42 are connected (rigidly fixed) to the lateral surface 41 of the hub 40. In one embodiment of the invention, the blades 42 are distributed angularly equidistant from each other; in some embodiments of the invention, the blades 42 could however be distributed in a different way, in relation to specific needs. In a preferred embodiment of the invention, the fan 9 comprises six blades 42.

Each of the blades 42 of the fan 9 includes a leading edge 43, a trailing edge 44, a proximal edge 45 and a distal edge 46. By proximal edge 45 is meant the edge of the blade 42 connected to the lateral surface 41 of the hub 40. The orientation of the blades 42, with respect to the axis of the hub 40, is that typical of an axial fan, but which induces an axial-centrifugal flow (in particular, the arrangement of the proximal edges 45 of the aforementioned blades 42). According to one aspect of the invention - and as can be seen, in particular, in Figures 6, 7, 8 - each of the blades 42 of the fan 9 has an increasing transversal extension proceeding from the hub 40 towards the periphery, and therefore from the proximal edge 45 to the distal edge 46. In other words, each blade 42 has a substantially divergent shape as it proceeds from the hub 40 towards the periphery. Furthermore, according to another aspect of the invention, each of the blades 42 has a substantially "S" profile. In more detail, each of the leading edges 43 and trailing edges 44 of each blade 42 has a double curvature in the section between the proximal edge 45 and the distal edge 46. This double curvature of the leading 43 and trailing 44 edges causes the blade 42 to form a sort of preferential passageway 47 for the passage of the air flow in the inlet/outlet direction (schematized with a broken line in Figures 10-12). As shown, in particular, by Figure 12, the aforementioned passageway 47, defined by the double curvature of the profile of each blade 42, allows to obtain a sort of diffusing effect of the air flow which passes through it: this expedient allows to achieve a greater control of the aerodynamic actions that determine the generation of the jet 29. As already highlighted in several parts of the present description, the invention thus conceived allows to obtain important technical advantages. In the first place, the actuation of one or more distributor elements 2 of the distribution unit 1 is, according to the present invention, actuated by means of an electric motor 10 which moves the fan 9, so as to completely replace the traditional mechanical or mechanical/hydraulic drives. This has a significant positive impact on the costs of the equipment and also on its energy consumption. Furthermore, the actuation of one or more distributor elements 2 is carried out by means of a system 32 which operates at low voltage, which represents a safer, simpler and more effective power supply method. It is also observed that the use of synchronous motors of the brushless type, for driving the fans 9 of one or more distributor elements 2, is very advantageous as regards the optimization of the main operating parameters of each of the elements 2 themselves in different situations; this last result is very important to obtain a high flexibility of the machine, and also to increase the effectiveness in the execution of the treatments. It has thus been seen how the invention achieves the proposed aims. The present invention has been described according to preferred embodiments, but equivalent variants can be devised without departing from the scope of protection offered by the following claims. Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavor to which this specification relates.

Claims

CLAIMS 1. Distribution unit (1) for an agricultural atomizer, comprising at least one support structure (3) and at least one distributor element (2), associated with said support structure (3), and configured to direct a flow of a mixture of air and a nebulized treatment fluid, towards the foliage of the plants or crops to be treated, said distributor element (2) comprising at least a fan (9) and nebulization means (23) of the treatment fluid to be mixed with the flow of air generated by said fan (9), characterized in that it comprises at least one generator (30), which can be coupled to a heat engine of the atomizer, and in that said distributor element (2) comprises an electric motor (10), on whose output axis (11) said fan (9) is keyed, an electrical power supply system (32) being provided which connects said generator (30) to said at least one distributor element (2), said system (32) being configured to power said electric motor (10) at low voltage.
2. Distribution unit (1) according to claim 1, wherein said electric motor (10) is a synchronous alternating current motor of the brushless type.
3. Distribution unit (1) according to claim 2, wherein said system (32) comprises a rectifier (33) connected to the output of said generator (30), at least one inverter (34), connected to said electric motor (10) of said at least one distributor element (2), and a line (35), connected to the output of said rectifier (33), which powers said inverter (34).
4. Distribution unit (1) according to claim 2 or 3, wherein said system (32) comprises at least one rechargeable battery (36) connected in parallel to said line (35), and a battery management system (37) which manages the recharging process of said battery (36).
5. Distribution unit (1) according to one of the preceding claims, comprising a plurality of said distributor elements (2) powered in parallel by said system (32), and associated with said support structure (3) according to a plurality of modifiable configurations.
6. Distribution unit (1) according to claim 5 when dependent on claim 4, wherein said system (32) comprises at least one control unit (38), and a bus (39) of the CAN type which operatively connects said inverters (34) and said battery management system (37) to said control unit (38), said control unit (38) being operatively connected to at least one user interface.
7. Distribution unit (1) according to one of the preceding claims, wherein said distributor element (2) comprises a delivery duct (13) of the flow of the air-fluid mixture generated by said fan (9), configured to act as a diffuser of said flow, said delivery duct (13) comprising a circular, or substantially circular, inlet section (20), and an outlet section (21) having a shape which is elongated transversely to the direction of flow of the air-fluid mixture.
8. Distribution unit (1) according to claim 7, wherein said nebulization means (23) of the fluid to be mixed with the air flow comprise at least one supply pipe (23), housed inside said delivery duct (13) so as to be interposed between said inlet section (20) and said outlet section (21) of said delivery duct (13), said supply pipe (23) comprising a plurality of nebulization nozzles (24) of the treatment fluid, said supply pipe (23) having a curved shape with convexity facing the outlet section (21) of said delivery duct (13), said supply pipe (23) being oriented according to the major axis of said outlet section (21) of said delivery duct (13).
9. Distribution unit (1) according to one of the preceding claims, wherein said fan (9) comprises a hub (40), having a lateral surface (41), and a plurality of blades (42) connected to said lateral surface (41), said blades (42) being configured and oriented so as to obtain a mixed axial-centrifugal flow.
10. Distribution unit (1) according to claim 9, wherein each of said blades (42) comprises a leading edge (43), a trailing edge (44), a proximal edge (45) and a distal edge (46), and in which each of said leading (43) and trailing (44) edges defines, in the section between said proximal edge (45) and said distal edge (46), a double curvature, so that each of said blades (42) it has a substantially S-shaped profile, so that each of said blades (42) forms a sort of preferential passageway (47) for the air flow in the inlet/outlet direction with a diffusing effect.