Agricultural field sprayer and spraying device for an agricultural field sprayer

Abstract

The invention relates to a spraying device for an agricultural field sprayer for the metered application of spray liquid, preferably on agricultural land. The invention further relates to an agricultural field sprayer with such a spraying device. The spraying device (10) comprises a first metering system (30), a second metering or supply system (40), and a pivotable spray boom (11) for applying spray liquid. Several application elements (13) for applying the spray liquid and several mixing devices (20) for mixing the spray liquid are provided on the central section and the two lateral extensions (11) of the spray boom. The mixing devices (20) are each assigned to one of the application elements (13), and spray liquid from the first metering system (30) and the second metering or supply system (40) can be supplied to each mixing device (20) at its inlet.This allows for the advantageous provision of a direct feed-in system with high flexibility and simultaneously a high maximum flow rate.

Description

[0001] The invention relates to a spraying device for an agricultural field sprayer for the metered application of spray liquid, preferably on agricultural land. The spraying device comprises a spray boom with lateral extensions, at least two metering systems, and mixing devices for blending the spray liquid. The invention further relates to an agricultural field sprayer with such a spraying device.

[0002] Agricultural sprayers are used for spreading or applying liquid active ingredients, such as pesticides and / or fertilizers. These sprayers, with a spray boom oriented transversely to the direction of travel and moved over the crop, are known in various designs.

[0003] The purpose of these field sprayers is to apply a defined volume of liquid, such as pesticides and / or fertilizers, evenly and with a definable intensity to a crop. To distribute the liquid over a large area of ​​the fields, the spray booms of these field sprayers feature laterally foldable extensions with a wide working width, sometimes exceeding twenty meters. For transport, these wide spray booms are folded and collapsed. When unfolded, the extensions are positioned perpendicular to the direction of travel. The spray boom is equipped with application elements, such as spray nozzles, arranged at intervals to precisely meter the liquid. These application elements create a spray cone directed towards the ground or the crop to achieve the desired distribution of the liquid.

[0004] To save on passes and to be able to quickly change the active ingredient composition according to the requirements on the field, so-called "direct injection systems" are known from the prior art, in which an active ingredient dissolved in a liquid, e.g. a plant protection product to be applied, can be added to a carrier liquid or a ready-mixed spray liquid by direct injection as needed.

[0005] However, the field sprayers commonly used in practice have the disadvantage that, with centralized dosing via direct injection, significant time delays occur if the injection point is too far from the spray nozzles and the fluid paths from the injection point to the individual spray nozzles also differ considerably. This results in the so-called butterfly effect, as the spray mixture generated by direct injection does not immediately reach all spray nozzles, but only builds up over the entire working width with a delay, leading to an uneven distribution of the active ingredient, at least temporarily.

[0006] To avoid these disadvantages, for example, a direct feed system with several dosing systems is known from DE 10 2020 128 771 A1, in which several spray nozzles of a partial width of the spray boom are each fluidically connected to a mixing chamber via equally long application lines.

[0007] Practical trials have now shown that using pipes of equal length can also lead to problems in certain applications. To ensure fast shutdown times, these pipes must have a high flow rate, which means their cross-section cannot be too large. On the other hand, these small cross-sections result in limited maximum flow rates, which can cause problems, especially in fertilizer applications.

[0008] It is therefore an object of the invention to provide an improved technique for applying spraying liquid using a spray boom, thereby avoiding the disadvantages of conventional techniques. In particular, the object of the invention is to provide a technique for applying spraying liquid using a spray boom which, while maintaining the same flexibility compared to known techniques, allows for a significant increase in maximum delivery rates.

[0009] According to a general aspect of the invention, a spraying device for an agricultural field sprayer is provided for the metered application of spray liquid, preferably on agricultural land.

[0010] The spraying device initially comprises at least two metering or supply systems from which spraying fluid can be supplied, each with a reservoir for the spraying fluid and means for supplying the spraying fluid from the respective reservoir as needed, preferably in a metered manner. These multiple metering or supply systems are described below. For clarity, the terms first, second, etc., are used to better distinguish, for example, the first metering system and its spraying fluid (first spraying fluid) from a further, e.g., second or optionally third, metering system and its spraying fluid (third spraying fluid), etc.

[0011] The spraying device thus comprises a first metering system with a first reservoir for a first spraying liquid and a first metering device. The first reservoir can be the main tank of the spraying device or a field sprayer, i.e., the tank containing the main mixture. The main mixture is understood to be the spraying liquid, usually already mixed, that is to be used primarily by the spraying device or field sprayer in an upcoming spraying operation and / or that is stored in the largest spraying liquid reservoir of the field sprayer. However, the first spraying liquid can also be clear water or another carrier liquid. The first metering device is designed to dispense the first spraying liquid from the first reservoir in a metered manner. The first metering device can include a flow meter and a pressure generation unit, preferably a pump.

[0012] The spraying device further comprises a second metering or supply system, including a second reservoir for a second spraying fluid, for example, clear water or another carrier fluid, and a second metering or fluid supply device. This second metering or supply system is not necessarily intended to provide a precise or accurately metered quantity of spraying fluid, but could also function as a supply tank from which the second spraying fluid can be provided as needed, without, for example, a metering valve for precise dosing. Therefore, the terms metering or supply system and metering or fluid supply device were chosen here to clarify this aspect. The second metering or fluid supply device may include a flow meter, a check valve, and / or a pressure generating unit, preferably a pump.It is possible that the second dosing or supply device does not include a dosing valve. The second storage container could be a water tank.

[0013] The spraying device further comprises a swiveling spray boom, consisting of a central section and two lateral arms. The arms and the central section each have several dispensing elements for applying the spraying liquid and several mixing devices for blending the spraying liquid.

[0014] In this configuration, each mixing device is assigned to one of the application elements, and each mixing device can be supplied with spray fluid from the first metering system and the second metering or supply system on its inlet side. In other words, each application element can be supplied with spray fluid via exactly one of the mixing devices. Each mixing device can be fluidically coupled to, or be in fluid contact with, or bring into contact with, one of the application elements on its outlet side. The mixing devices are therefore preferably arranged in the area of ​​the application elements; that is, exactly one mixing device is located in the area of ​​each application element.Advantageously, spray liquids can be mixed directly in front of the application element (or in the application element), whereby optionally the applied spray liquid and / or its mixture can be individually adjusted for each application element or at least for each partial width, while at the same time a high maximum delivery rate can be achieved.

[0015] Providing a mixing device on each application element, in combination with at least two metering or supply systems, offers the advantage of enabling site-specific application via direct feed to smaller sub-areas, while simultaneously achieving a high maximum delivery rate and improved uniform application of the active ingredient, especially during start-up and shut-down processes and changes to the spray liquid or its mixture.

[0016] In a preferred embodiment, the mixing devices are each formed by a mixing chamber arranged upstream of its associated dispensing element. The mixing chamber has a first inlet through which spray fluid from the first metering system can be supplied to the mixing chamber, and a second inlet through which spray fluid from the second metering or supply system can be supplied to the mixing chamber. The mixing chamber further comprises a chamber or container in which the spray fluids are mixed before being supplied to the associated dispensing element via an outlet. Alternatively, the mixing chamber can also be (structurally) integrated into the associated dispensing element.

[0017] In another alternative embodiment, the mixing devices are each formed by a pipe section for spray fluid, which is arranged upstream of the associated dispensing element. The pipe section is advantageously designed so that two spray fluids supplied on the inlet side can also mix within it.

[0018] In a further embodiment, the spraying device also comprises a first supply line to which the mixing device is fluidically connected on the inlet side (inlet side) and to which the first spraying fluid can be supplied by the first metering device. The first supply line has branches for supplying the mixing devices with spraying fluid from the first metering system. These branches are therefore referred to below as first branches to better distinguish them from the second branches described below. The first supply line can, for example, be configured as a ring main or a branch line.

[0019] In a further embodiment, the spraying device also includes a supply line to which the second spraying fluid can be supplied via the second metering or fluid supply device, and which has a second branch for supplying the mixing devices. The second supply line can, for example, be configured as a ring main or a branch line.

[0020] The spraying device may optionally include a third metering system. This third metering system comprises at least one third metering device and at least one third reservoir and / or at least one reservoir for the detachable mounting of a third reservoir containing at least one third spray liquid or active ingredient. The third reservoir is preferably a canister, and / or the reservoir is preferably a holder for such a canister, which can be interchangeably mounted therein. The third spray liquid or active ingredient may be a plant protection product, preferably in concentrated form. The plant protection product may be a growth regulator, fungicide, insecticide, pesticide, and / or the like in liquid form. Alternatively, it may be a granular product that can be dissolved in liquid.The volume of the third storage container is preferably smaller, usually significantly smaller, than the volume of the first and / or second storage container.

[0021] Several such third container receptacles and / or third storage containers with corresponding third metering devices can also be provided as part of the third metering system, for example, to carry different third spray liquids, such as different plant protection products, which can be added as needed. The at least one third metering device can each comprise a metering valve, a flow meter, and a pressure generation unit, preferably a pump.

[0022] The third dosing system can preferably be designed as a closed transfer system (CTS) to avoid direct contact between an operator and the third spray liquid stored in the third reservoir.

[0023] According to a further embodiment, a switching valve is arranged in the first branch upstream of each mixing device. The first switching valve can be set to an open position and a closed position. Advantageously, this prevents (in the closed position) any splashing liquid from the mixing devices from being forced back into the first supply line. This switching valve is subsequently referred to as the first switching valve to better distinguish it from a further, optionally present, second switching valve.

[0024] Alternatively, a first switching valve can be arranged downstream of each mixing device to control the spray liquid dispensed via the associated dispensing element. Advantageously, this allows the dispensing element to be switched in a controlled manner, i.e., supplied with spray liquid from the mixing device in a controlled manner, thus preventing, for example, overflow.

[0025] Furthermore, it can be provided that an additional switching valve (hereinafter referred to as the second switching valve) is arranged upstream of each mixing device in the second branch. The second switching valve can be switchable between an open and a closed position. In this case, the first and second switching valves, which are assigned to the same mixing device, are operatively connected to each other such that actuation of the first switching valve triggers actuation of the second switching valve, or vice versa. Advantageously, the flow of the spray fluid in the second branch can be controlled more reliably and in a structurally simple manner.

[0026] As an alternative to a separate second switching valve, its function can also be integrated into the first switching valve. In one embodiment of this, the first switching valve can furthermore be fluidically connected to the second branch assigned to the mixing device and be configured to selectively open or close the flow to and from the mixing device through the second branch.

[0027] The first switching valve and / or the second switching valve can be designed as a 2-way switching valve, preferably as a pneumatically actuated, double-acting 2-way valve. According to the embodiment in which the function of a second switching valve is integrated into the first switching valve, the first switching valve can, by way of example only, be designed as a 4 / 2-way valve.

[0028] According to a further embodiment, at least one fluid distributor is arranged in each of the second branches for distributing the spraying fluid branched off from the second ring line or spur line into several partial flows. This allows for improved, section-specific application of spraying fluid at high flow rates. The fluid distributor has an inlet through which it is supplied with spraying fluid from the second ring line or spur line, and also several distributor outlets for the partial flows. Each of the mixing devices is fluidically connected on its inlet side (inlet side) to one of the distributor outlets via a discharge line. In a further embodiment, the number of distributor outlets of the fluid distributor can range from 3 to 8. For example, each fluid distributor can have four distributor outlets to supply four application elements.This allows for a favorable compromise between short delay times and the number of fluid distributors required. The section width enables, for example, a variable application rate or spot application; for instance, spot application within a 1-meter area is possible. Furthermore, the application rate of the spreading elements can be adjusted to the curve, for example, increasing the rate for the outer spreading elements compared to the inner ones.

[0029] Another aspect is that each dispensing line is equipped with an orifice plate, a throttling device, and / or a check valve. This allows for better control of the spray fluid flows. The orifice plate and / or throttling device enables advantageous adjustment of the flow rate for introducing the spray fluid into the respective mixing devices. The check valve prevents unwanted backflow to the fluid distributor. The orifice plates used can have a fixed cross-section or can be adjustable.

[0030] The application lines can optionally be of the same length. This offers the advantage of avoiding or at least reducing differences in the time delays until the spray fluid reaches the individual application elements. This also ensures that the partial flow paths from the distributor outlet to the application element are the same length for all application elements, even though the spatial distances of the application elements to the distributor outlet through which they are supplied may vary. Additionally, or alternatively, the application lines can be made of a flexible material or be designed as hose lines. Even more preferably, each application element is fluidically connected to one of the distributor outlets via a separate application line.

[0031] Preferably, a flow meter and a valve (hereinafter referred to as the feed valve or metering valve) are arranged upstream of each fluid distributor in the second branch. Advantageously, the spray fluid supplied to each fluid distributor or each second branch can be individually metered. The feed valve can be designed as a pulse valve and / or as a pulse-width modulated (PWM) valve, i.e., the valve can be controlled and / or regulated by means of pulse-width modulation, which enables particularly precise metering of the spray fluid.

[0032] In a particularly preferred embodiment, the spray boom is divided longitudinally into sections. Each section is assigned one of the fluid distributors to supply the group of application elements and associated mixing devices assigned to that section with spray fluid. This improves precise, section-specific application of the spray fluid. The fluid distributors are preferably arranged longitudinally along the spray boom, for example, in the area, preferably centrally, of the group of application elements assigned to each fluid distributor.

[0033] Advantageously, efficient section control can be achieved by combining the control of valves located directly in the nozzle area, which are e.g. pneumatically actuated, with the control of the aforementioned feed valves. Alternatively, an electric individual nozzle control (electric EDS) or pulse nozzle valves can be used for the respective valves.

[0034] At least some of the second branches can have a junction point that provides multiple pipe branches. Each pipe branch connects the junction point to one of the fluid distributors. The junction point is preferably configured as a Y-junction or a T-junction. If a pipe branch has a junction point, the flow meter is preferably located upstream and the feed valve preferably downstream of the junction point. In this case, a feed valve is provided in each pipe branch. For example, in one possible embodiment, twice as many feed valves as flow meters can be provided in the second branches with a junction point. By way of example only, one feed valve can be provided per meter of working width and one flow meter per two meters of working width.

[0035] According to a further embodiment, the spraying device also has a supply line through which spraying fluid from the first storage container can be fed to the second metering or supply system. For example, the supply line can lead downstream from the second storage container into the second metering or supply system. This allows spraying fluid from the first metering system, which typically includes the main tank, to be transferred to the second metering or supply system for use as needed, thus increasing the flexibility of the spraying device.

[0036] The spraying device further comprises a control unit designed to control and / or regulate the first metering system, the second metering or supply system, the dispensing elements, and, if present, the third supply system for spraying and / or finely distributing the spraying liquid. The control unit is also in signal communication with the other components of the spraying device, such as sensors, valves, flow meters, orifices, etc., and can also control these components, provided they are controllable.

[0037] In one embodiment, the control device can be configured to selectively supply the application elements or application elements of selected sections with a mixture of at least two of the spray liquids in a definable mixing ratio or with only one of the spray liquids by controlling the first metering device, the second metering or fluid supply device, and optionally at least one third metering device, preferably by supplying these spray liquids to the mixing devices or a selection thereof in the definable mixing ratio. Accordingly, the mixing ratio can be changed for the sections individually or even for individual application elements.Alternatively or additionally, the control device for producing a mixture of the first spray liquid with the second and / or optionally at least a third spray liquid can be designed to control the first metering system and to control the second metering or supply system and / or optionally the third metering system in such a way that all mixing devices or a selection thereof are supplied with both the first spray liquid and the second and / or optionally the third spray liquid in the definable quantity ratio.

[0038] According to a further embodiment, the spraying device also has a further mixing chamber to which the second spraying liquid can be supplied via the second metering or fluid supply device and the at least one third spraying liquid via the at least one third metering device, and which is fluidically connected to the second ring line or branch line on the outlet side. This mixing chamber is hereinafter referred to as the main mixing chamber, for better differentiation from the mixing devices.

[0039] In an advantageous embodiment of this design, the control unit is configured to control the second metering or fluid supply unit and the at least one third metering unit, depending on a target mixing ratio of the second and third spray liquids, such that the second and third spray liquids are supplied to the main mixing chamber at the input side in the target mixing ratio. The target mixing ratio can be set depending on which third spray liquid is currently being mixed, so that, for example, different target mixing ratios can be set for different plant protection products. The target mixing ratio can optionally be set by user input or automatically by reading it via a data interface. The third spray liquid can be pre-diluted according to the target mixing ratio.

[0040] If the third dosing system has several third storage containers with corresponding third dosing devices, the control unit for supplying metered quantities of plant protection product and / or third spray solution can be configured to control the third dosing devices in such a way that one or more of the plant protection products are selectively supplied to the main mixing chamber in a definable dose. Different plant protection products can thus be added directly as needed.

[0041] Furthermore, the following additional aspects are revealed: The application element can be a spray nozzle or a nozzle holder (also called a nozzle assembly) in which at least one spray nozzle is mounted. The nozzle holder can be designed as a multi-nozzle holder, e.g., as a 1- to 4-nozzle holder. The application elements can be controlled separately to allow them to be switched on and off individually during spraying. A switching valve or controllable orifice can be assigned to the application element to control the flow rate, e.g., the first switching valve mentioned above. The application elements can optionally be controlled and / or regulated by pulse width modulation. The application elements are spaced apart from each other along the length of the spray boom, for example, at intervals of 25 cm or 50 cm.

[0042] The spray boom can be mounted directly or indirectly on a carrier vehicle so that it is movable about a pivot axis (A) extending in the direction of travel. Alternatively or additionally, the two lateral booms can each be rotatably connected to a central section of the spray boom via a vertical pivot axis.

[0043] Each boom can in turn have several linkage sections connected by joints, which can be folded together for transport and unfolded for working. This allows each of the two booms of a sprayer boom to be folded, preferably multiple times, by folding the respective linkage sections 180° at the joints for transport or unfolding them into a straight position for working. In the unfolded state, the sprayer boom extends transversely to the direction of travel of the sprayer.

[0044] According to a further aspect, the invention also relates to an agricultural field sprayer comprising a spraying device as described in this document. The field sprayer can be self-propelled, towed by a tractor, or mounted on a tractor. The self-propelled spreading machine can also be an autonomously operating agricultural machine, for example, a fully autonomous or semi-autonomous one.

[0045] The spray boom of the spraying device and / or the field sprayer has a large working width, i.e., a working width that is significantly greater than the width of the carrier vehicle or the field sprayer, e.g., a multiple of the carrier vehicle's width. The field sprayer may, in a manner known per se, include an actuating device, e.g., pneumatic or hydraulic cylinders, by means of which an actuating force can be generated to move the distributor boom around the pivot axis. For movable mounting on the carrier vehicle, the spray boom may, for example, be mounted on a support beam, which in turn may be coupled, for example, to a superstructure or frame section or frame construction of the carrier vehicle and / or to a rigidly or movably mounted support section of the carrier vehicle.

[0046] At least one distance sensor, e.g., an ultrasonic sensor, can be arranged on the boom to measure the distance to the ground or vegetation. The sprayer and / or the spray boom can also include, in a manner known per se, at least one sensor device for detecting the rotational position and / or rotational speed and / or acceleration of the spray boom, e.g., an accelerometer.

[0047] As previously stated, flow meters can be installed in each of the second branches. In a further embodiment, the control unit can be designed to perform fault diagnosis based on the flow meter readings, for example, to detect and locate blockages, such as whether and in which of the second branches a blockage exists. By comparing the flow meter readings, a fault diagnosis (e.g., a blockage) can be localized, for example, to a distance of 1 meter.

[0048] It is also optionally possible to include an agitator in the optional third storage tank to prevent, for example, the build-up of the respective agent within the tank. Cleaning of the spray system or the dosing systems can be carried out in a manner known from the prior art. Alternatively or additionally, the third storage tank can be supplied with clean water for cleaning purposes via an additional line, e.g., a flushing line, and a valve and / or pump associated with this line. This clean water could, for example, come from the first dosing system and / or the second dosing or supply system.

[0049] The longitudinal direction of the boom and spray boom refers to the direction in which the boom extends and in which the application elements, such as the spray nozzles or nozzle holders, are spaced apart along the boom. The working width of the spray boom is determined by its length along its longitudinal direction when extended. The vertical direction of the boom refers to the direction perpendicular to the boom's longitudinal direction and perpendicular to the sprayer's direction of travel.

[0050] The preferred embodiments, variants, and features of the invention described above can be combined with one another as desired. Further details and advantages of the invention are described below with reference to the accompanying drawings. These show: Fig. 1 a perspective view of an agricultural field sprayer with a chassis having a frame construction and a spraying device; Fig. 2 a fluid diagram of a spraying device of an agricultural field sprayer according to one embodiment; and Fig. 3 schematic detail views to illustrate the supply of a mixing device with spray fluid according to different embodiments.

[0051] The embodiments shown in the figures are at least partially identical, so similar or identical parts are marked with the same reference numerals, and reference is made to the descriptions of the other embodiments or figures to avoid repetition. Furthermore, for the sake of clarity, not all components that appear multiple times are marked with reference numerals.

[0052] Fig. Figure 1 shows a perspective view of an embodiment of an agricultural field sprayer 1 with a chassis 3 having a frame construction, wherein the chassis 3 also has a running gear 2. The field sprayer 1 is shown here as an exemplary self-propelled field sprayer and comprises a cab 4 with an operator's station and a drive unit 5 (e.g., engine). At the rear, the field sprayer 1 includes a spray boom 11 in a working position, extending transversely to the direction of travel 6 with a large working width, e.g., 24 meters or more, which can be pivoted about a pivot axis A extending in the direction of travel by means of an actuating device. The spray boom 11, also referred to as a spray bar assembly, is height-adjustable relative to the chassis 3 by means of a height-adjustable parallelogram linkage 9. A spraying device according to the invention is also mounted on the chassis 3, wherein in the Fig. Figure 1 shows only the spray boom 11 and one of several storage tanks. The spray boom is pivotable about an axis pointing in the direction of travel A and comprises a central section 11a and two lateral arms 12, each of which has a plurality of application elements for spraying and / or finely distributing the spray liquid. Furthermore, a control unit 8 is provided, which is in signal communication with the individual components of the spraying device, such as the application elements, pumps, valves, and flow meters, in order to control them appropriately for the application of the spray liquid. The control unit 8 serves in particular to control the different metering systems, as will be explained in more detail below.

[0053] A particularly preferred embodiment of a spraying device 10 is described in Fig. 2 shown. The spraying device 10 comprises several metering systems in order to apply different mixing ratios of spray liquid to specific areas and via direct feed with minimal delay. Fig. Figure 2 shows a fluid diagram of the embodiment. The spray boom and the extension arms are shown in the fluid diagram. Fig. 2 not shown.

[0054] At the in Fig. In the spraying device 10 shown in Figure 2, the spray boom 11 is divided along its longitudinal direction B into several sections 60. Here, five sections 60 are shown as an example. A plurality of application elements 13 are arranged on each section 60, and each application element 13 is assigned to exactly one section 60. The application element 13 can be a spray nozzle or a nozzle holder in which at least one spray nozzle is held.

[0055] Furthermore, each application element 13 is assigned exactly one mixing device 20. The mixing device 20 is arranged downstream of the respective application element 13 in the area of ​​the application element 13 on the spray boom. The mixing device 20 can be designed as a mixing chamber 20. Alternatively, the mixing device can be designed as a pipe section in which two spray liquids supplied to the pipe section can mix.

[0056] As mentioned, the spraying device includes 10 multiple dosing systems to enable flexible direct feeding with site-specific application.

[0057] The spray device 10 comprises a first metering system 30, with a first reservoir 31 for a first spray liquid 37 and a first metering device 32, 33. The first reservoir can be, for example, the tank 7 made of Fig. The first storage tank 31 is the main tank for a first premixed spraying liquid, e.g., a main mixture of spraying liquid. This is the mixture that will be applied predominantly during an upcoming spraying operation. The first storage tank may also be provided with a connection for, or coupling to, for example, an induction hopper (not shown) in order to fill the main tank accordingly.

[0058] The first metering device comprises a flow meter 33 and a pressure generation unit, for example a pump 32, for conveying the first spray liquid 37. Alternatively to the pump 32, it would also be conceivable that the delivery pressure is generated by means of a compressor, which is, for example, functionally connected to the first storage container 31.

[0059] In the first dosing system 30, a circulation valve 34 is also arranged. This is controlled by the control unit 8, for example, so that it is closed when the spray nozzles 13 are open in order to generate sufficient spray pressure, and it is open when the spray nozzles 13 are closed in order to prevent, for example, deposits in the system.

[0060] The first metering system 30 is fluidically connected to a first supply line 35, to which the first spray liquid 37 can be supplied from the first storage container 31 by means of the first metering device 32, 33. The first supply line 35 is designed here as a ring line or circulation line, which has a section extending longitudinally along the spray boom 11 and running parallel to it, with several branch points 36 and first branches 14 corresponding to the application elements 13. A design as a dead-end line would also be possible.

[0061] For the sake of clarity, not all branch points, junctions, application elements, etc. are to be understood with reference symbols. At a branch point 36, spray liquid 37 is diverted for each of the mixing devices 20 and supplied to the mixing device 20 via a first branch 14.

[0062] The mixing device 20 can optionally be supplied with spray fluid 37 from the first dosing system 30 and / or from a second dosing or supply system 40 and an optionally available third dosing system 50, which are described below.

[0063] The spraying device 10 further comprises a second metering or supply system 40, comprising a second reservoir 41 for a second spraying liquid 47 and a second metering or fluid supply device 42, 43. The second spraying liquid 47 is, for example, fresh water (clean water) and the second reservoir 41 is a water tank, whereby another carrier liquid for an active ingredient can also be used.

[0064] The second metering or fluid supply unit comprises a flow meter 43 and a pressure generating unit, preferably in the form of a pump 42 (charging pump for fluid delivery). The pump 42 could also be replaced by selectively pressurizing the reservoir 41, e.g., using a compressor. A check valve 45 is arranged downstream of the pump 42 to prevent unintentional mixing of the fresh water with the plant protection product from the third metering system 50 described below. This second metering or supply system 40 is not necessarily intended to provide a precise or well-metered quantity of spray liquid, but essentially only generates pressure to supply fresh water 47. Precise quantity control, as in the first or third metering systems 30, 50, is not provided here, but would be possible.A metering valve is not provided, but would be possible to increase metering accuracy.

[0065] The spray device 10 can further comprise a supply line 38 through which spray fluid from the first storage container 31 can be supplied to the second metering or supply system 40. For example, the supply line 38 can lead downstream from the second storage container 41 into the second metering or supply system 40.

[0066] The spraying device 10 can optionally further comprise a third metering system 50. The third metering system 50 comprises at least one third metering device 52, 53, 54 and at least one third storage container 51 and / or at least one container mount for the detachable attachment of a third storage container 51. The third spraying liquid is a plant protection product, for example, a growth regulator, fungicide, insecticide, pesticide, and / or the like. The third storage container can be a canister. The third metering system 50 can include a container mount provided on the field sprayer to detachably hold the canister as an interchangeable container. The third metering device comprises a metering valve 54, a flow meter 53, and a pressure generating unit, preferably again configured as a pump 52. Several such third storage containers or containers can be provided.Container intakes and several associated third dosing devices should be provided, depending on how many different third spray liquids, for example how many different plant protection products, are to be applied by direct injection.

[0067] The third dosing system can preferably be designed as a closed transfer system (CTS) to prevent direct contact between the operator and the third spray solution stored in the third reservoir. Such CTS systems are well-known in practice and were developed to ensure the safe and environmentally friendly handling of plant protection products. The main objective of a CTS is to minimize (or avoid) direct contact between the user and the spray solution or chemicals, while simultaneously preventing leaks or spills.

[0068] The injection device of the exemplary embodiment of the Fig. 2 further comprises a further mixing chamber 70, referred to here as the main mixing chamber. A second spray fluid 47 can be supplied to the main mixing chamber 70 via a feed line of the second metering system 40 by the second metering or fluid supply device 42, 43, and at least one third spray fluid 57 can be supplied via one or more corresponding feed lines of the third metering system 50 by the at least one third metering device 52, 53, 54. On the outlet side, the main mixing chamber 70 is connected to a second feed line 100 to supply the spray fluid mixture produced by the main mixing chamber 70 to the mixing devices 20. In the present example, the second feed line 100 is designed as a circulation line or ring line, in which a pump (feed pump) 102 and a throttle valve 101 are also arranged.The main mixing chamber 70 is designed to mix, preferably homogeneously, the second and third spray liquids 47, 57 supplied to it via the second metering or supply system 40 and the third metering system 50, and then to discharge the mixed spray liquid into the second circulation line (ring line) 100.

[0069] The second circulation line (ring line) 100 comprises a section extending in the longitudinal direction of the spray boom 11 and guided along the spray boom 11, which has several branch points 103 for second branches 61, through which spray liquid is supplied to the application elements 13.

[0070] In each of the second branches 61, at least one fluid distributor 80 is arranged for distributing the spray fluid branched off from the second ring line 100 or spur line into several partial flows. The fluid distributor 80 has several distributor outlets for the partial flows, with each of the mixing devices 20 being fluidically connected on its inlet side to one of the distributor outlets via a discharge line 15.

[0071] It has already been established that the spray boom is divided longitudinally into sections 60. Each section 60 is assigned one of the fluid distributors 80 to supply the group of application elements 13 and associated mixing devices 20 assigned to that section 80 with spray fluid. For illustrative purposes only, this is shown here as four application elements 13 and four mixing devices 20 per section 60 or per fluid distributor 80. Accordingly, the fluid distributor has four outlets and four application lines 15.

[0072] Optionally, at least some of the second branches 61 can have a branch point 62 that provides a plurality of line branches. Each line branch connects the branch point fluidically to one of the fluid distributors 80. Here, only one branch point 62 is provided, configured as a Y-branch or a T-branch. A flow meter 63 and a feed valve 64 are provided upstream of each fluid distributor. If a branch point 62 is present, the flow meter 63 is preferably arranged upstream of the branch point 62 and the feed valve 64 downstream of it. For example, one feed valve 64 can be provided per meter of working width and one flow meter 63 per two meters of working width.

[0073] The mixing devices 20, which are arranged in the area of ​​the dispensing elements 13, are thus fluidically connected on the one hand via their first inlet to the first circulation line 35 and on the other hand via their second inlet to one of the dispensing lines 15 of the second branches 61 (and / or the fluid distributor 80).

[0074] The spray liquid flowing from the main mixing chamber 70 into the second circulation line 100 is conveyed by pump 102 towards the branch points 103. The portion of the spray liquid that was not fed to the mixing devices 20 via the branches 61 flows back towards the throttle valve 101 via the second circulation line 100 during circulation operation and, with pump 102 activated, can continue to circulate through the main mixing chamber 70 in the second circulation line 100. The spray liquid is thus circulated in the second ring line 100 to ensure that the correct / desired liquid, i.e., the liquid with the correct / desired concentration, is available as quickly as possible, i.e., without delay, at the required position of the spray boom.

[0075] The flow meters 63 and feed valves 64, each located in the branch lines 61, serve to control and / or regulate the quantity of second and / or third spray liquid supplied to the respective section 60. This liquid was previously mixed in the main mixing chamber 70. For this purpose, the control unit 8 communicates with the flow meters 63 and the feed valves 64 and controls the latter accordingly. The throttle valve 101 is located downstream of the branch lines 103, before the second supply line 100 returns to the main mixing chamber 70. Flow differences between individual branches 18 can be compensated for or even deliberately created via the flow meters 63 and feed valves 64, e.g., for section-specific application, in order to supply the respective mixing devices 20 only the quantity of second and / or third spray liquid 47, 57 required for the section-specific application.

[0076] To enable the application of spray fluid to specific sub-areas, the control device 8 is designed to selectively supply a mixture of at least two of the spray fluids 37, 47, 57 in a definable mixing ratio or only one of the spray fluids to all mixing devices 20 or mixing devices 20 of selected sub-sections 19 by controlling the first metering device 32, 33, the second metering or fluid supply device 42, 43 and the at least one third metering device 52, 53, 54 and the feed valves 64.

[0077] In the mixing devices 20, the supplied spray liquids are mixed (if spray liquid is supplied to a mixing device 20 simultaneously via both the first branches 14 and the second branches 61). The spray liquid dispensed from the respective mixing device 20 is supplied to the respective dispensing element 13 via a first switching valve 16.

[0078] Fig. Figure 3 illustrates further possible design variants for supplying a mixing device 20.

[0079] According to version A of the Fig. 3 The mixing device 20 is connected at a first inlet via the first branch 14 on the inlet side to the main circulation line or first ring line 35 and via a second inlet to the discharge line 15 of a fluid distributor 80 (as in Fig. 2 described). A baffle 17 and a check valve 18 are arranged in the discharge line 18.

[0080] The apertures 17 used can have a fixed cross-section or, alternatively, be controllable. As an alternative to the apertures 17, the function of the apertures 17 can be achieved by appropriately adjusted cable lengths and cross-sections (not shown).

[0081] The spray liquid mixed in the mixing device 20 is fed to a first switching valve 16 via an outlet of the mixing device 20. The first switching valve can be, for example, a two-way switching valve, preferably a pneumatically actuated, double-acting two-way valve. Alternatively, the first switching valve 16 can also be a PWM valve. The spray liquid supplied to the spray nozzle 13 can be controlled by actuating the first switching valve 16. The direct arrangement of the first switching valve 16 upstream of the spray nozzle 13 has the advantage that the spray nozzle 13 can be switched in a controlled manner and, for example, overflow is prevented. However, a disadvantage is that liquid from the mixing device 20 may be forced back into the main circulation line 36.

[0082] To prevent this, according to implementation variant B, the Fig. 3. The first switching valve 16 may also be arranged upstream of the mixing device 20. This results in the opposite advantages and disadvantages compared to variant A.

[0083] According to version C of the Fig. In addition to the first switching valve 16 according to embodiment A, a second switching valve 19 is also provided, which is arranged in the discharge line 15. The first switching valve 16 and the second switching valve 19, which are assigned to the same mixing device 20, are operatively connected to each other such that actuation of the first switching valve 16 triggers actuation of the second switching valve 19, or vice versa. That is, opening (or closing) the first switching valve 16 triggers opening (or closing) of the second switching valve 19. The discharge line 15, which can also be referred to as the direct feed line, can be controlled and, if necessary, shut off by means of the second switching valve 19. Instead of the two coupled valves 16 and 19, it would also be conceivable to provide their function with a single, appropriately designed valve, e.g., a 4 / 2-way valve.Such a combination valve could be designed to selectively open or close not only the first branch 14, but also the discharge line 15.

[0084] The design variant D of the Fig. 3 corresponds to a further development of version variant B with a second switching valve 19, analogous to version variant C.

[0085] It goes without saying that, with reference to the Fig. 3 described techniques and features with the techniques and features that refer to the Fig. 1 and Fig. 2 are described, can be combined, individually or in any combination.

[0086] The invention is not limited to the preferred embodiments described above. Rather, a multitude of variants and modifications are possible, which also make use of the inventive concept and therefore fall within the scope of protection. In particular, the invention also claims protection for the subject matter and features of the dependent claims independently of the referenced claims. Reference symbol list 1 Agricultural field sprayer, e.g. trailed field sprayer 2 Chassis 3 chassis 4 cabins 5 Drive unit 6 Direction of travel 7 Storage tank 8 Control unit 9 Height-adjustable parallelogram linkage 10 Spray device 11 spray booms 11a Middle section 12 Side extension 13 Dispensing element, e.g. spray nozzle 14 First turn 15 Dispensing line 16 First switching valve 17 aperture 18 Check valve 19 Second switching valve 20 Mixing device 30 First dosing system 31 Storage tank, e.g. main tank 32 Pump 33 flow meters 34 Circulation valve 35 First supply line, e.g. first ring main, circulation line 36 First junction 37 First spray liquid, e.g. main mixture 38 Supply line 40 Second dosing or supply system 41 Storage tank, e.g. fresh water tank 42 Pump 43 flow meters 47 Second spray liquid, e.g.: fresh water 45 Check valve 50 Third dosing system 51 Storage tank, e.g. pesticide tank 52 Pump 53 flow meters 54 Metering valve 57 Third spray liquid, e.g. plant protection product 60 mm section width 61 Second branch 62 Junction 63 flow meters 64 Metering valve (feed valve) 70 Main mixing chamber 80 fluid distributors 100 Second supply line, e.g. second ring main, circulation line 101 Throttle valve 102 Pump 103 Second Junction A pivot axis in the direction of travel B Longitudinal direction of the boom QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2020 128 771 A1

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