Agricultural machine for spreading granular solids

Abstract

The invention relates to an agricultural machine for spreading granular solids, in particular seeds, comprising: a pneumatic conveying system for conveying the granular solids out of at least one solids tank (2) to a number of output units (4); a compressed-air-generating device (3), which is connected to a conveying airflow line (13) and a metering airflow line (6); wherein a supply line (8) branches from the metering airflow line (6) to each output unit (4); wherein a switching element (9) is arranged in each supply line (8) and the conveying airflow line (13) extends in series through the switching elements (9).

Description

[0001] Agricultural machine for spreading granular solids

[0002] The invention relates to an agricultural machine for spreading granular solids, in particular for spreading seed, by means of a pneumatic conveying system that transports the granular solids from at least one solids container to several discharge units. The final application from the discharge units onto or into the soil is carried out via a metered air stream. The granular solids can, in particular, be seed. Other solids, such as fertilizers, can also be applied with such machines.

[0003] EP 2 298 056 B1 already identifies disadvantages of the prior art described therein, which only allows discontinuous refilling of delivery units during the machine's turning process. Therefore, it proposes using overpressure for seed singulation also for seed delivery, whereby two separate lines for seed and air pressure must be routed to each delivery unit of the agricultural machine. This is complex and requires considerable construction.

[0004] WO 2011 / 056123 A1 shows a machine in which the discharge units are connected in series, and the combined supply of air and seed to maintain a continuous pressure is provided via a single, continuously narrowing line. Individually controlled filling of the discharge stations is therefore not possible.

[0005] In a machine described in EP 2 854 500 B2, the discharge units are supplied with seed and compressed air in parallel, with air recirculation provided. The number of required lines, their lengths, and the total space required are large.

[0006] The object of the invention is therefore to provide an agricultural machine and a method for spreading granular solids that avoids the aforementioned disadvantages, in particular, enabling a uniform feeding of the discharge units with granular solids and thus their precise spreading while preferably requiring minimal space. This object is achieved by a machine having the features of claim 1 and in a method having the features of claim 14.

[0007] To this end, the invention provides that a compressed air generation device, which may also contain multiple compressed air generators, but preferably only one, delivers both a conveying air stream and a metering air stream. The metering air stream is guided through a metering air stream line with individually branching supply lines to each delivery unit, whereas a conveying air stream line for the conveying air stream extends through individually controllable diverters. The diverters are located in the supply lines that branch off from the metering air stream line to each delivery unit.

[0008] According to the method according to the invention, the diverters can be controlled individually or independently of one another so that they can assume a conveying position in which the metering air flow is blocked and the conveying air flow containing granular solids is directed to the discharge unit, or a bypass position in which the conveying air flow is directed through the diverter to the next diverter. The diverters are arranged parallel in the dosing air flow, but in series in the conveying air flow. At the last diverter in a row, the conveying air flow ends or flows to a return line.

[0009] The solids to be spread are taken from a solids hopper or a grain hopper and from there fed to the delivery units. A delivery unit can also contain several dosing elements, in particular for example two sowing hearts, a double or tandem dosing system, which are supplied simultaneously via a supply line. All delivery units of the agricultural machine are preferably supplied from one solids hopper. However, several solids hoppers can also be provided for the machine, in particular if it operates with several sections, e.g. a right and a left wing. In such designs, the arrangement of the feeders according to the invention always relates to a jointly supplied section of the machine. The conveying air flow line runs in series one after the other through all the switches of the jointly supplied section of the machine.

[0010] In the agricultural machine operating according to the method, the granular solids or seed distribution from the preferably central solids container to the delivery units is carried out via a pneumatic conveyor. The compressed air generation device can be formed by a single blower, since a division into a conveying air flow and a metering air flow can occur. As already explained, however, it is also possible for the compressed air generation device to contain multiple compressed air generators and / or multiple blowers, in particular double blowers. Due to the design, this can be advantageous, particularly for machines with multiple sections, where one blower or one double blower can be provided per conveyor line.

[0011] The solids container of the agricultural machine can preferably be connected to the conveying air flow line via a discharge system. This can preferably be an injector, which is arranged between the solids container and the compressed air generation device in the transition to the conveying air flow line. Other feed systems, such as pressure tank locks, cell wheels, conveyor wheels, or augers, are also possible. The delivery units can preferably contain seed metering devices with pressure gradient singulation for seed application. In particular, compressed air singulation with overpressure compared to ambient pressure can contribute to the precise application of seed, although vacuum singulation is also possible.

[0012] Advantageously, the diverters of the agricultural machine are designed and arranged in the distribution system in such a way that each diverter can assume a conveying position or a bypass position. In the conveying position, the metering air flow is blocked and the conveying air flow is directed to the dispensing unit. In the bypass position, the conveying air flow is directed through the diverter to the next diverter or - if it is the last diverter in a row - is stopped or blocked. As an alternative to blocking the conveying air flow at the last diverter in a row, it is also possible to redirect it into the conveying air flow line in the manner of a ring line or into the solids container.

[0013] The switches of the agricultural machine according to the invention are preferably designed as at least 4-way / 2-way switches. They can also be exactly 4-way / 2-way switches.

[0014] The diverters can advantageously be designed with movable separating webs, which can particularly be in the form of pivoting flaps. These can be moved in such a way that, in the bypass position, they are at least substantially grain-tight against one another, and can be moved into the conveying position in such a way that the conveying air flow is directed to the discharge unit and the metering air flow in the diverter is interrupted. The essentially grain-sealing position of the separating webs in the bypass position does not necessarily have to be airtight, since a metering air flow to the discharge unit already flows in the bypass position.

[0015] A further preferred embodiment provides for the switches to be designed as rotary switches. They can preferably have a switch body with a barrel-shaped outer contour. The "outer contour" here refers to an imaginary casing of the switch body. The switch body does not have to have a complete, and in particular not a closed, outer surface. With a rotary switch constructed in this way, very good sealing can be achieved in a structurally simple manner. Such a rotary switch could also be referred to as a spherical switch, whereby the switch body does not have to be completely spherical; rather, the spherical caps on the axle exit sides can be omitted, thus creating the aforementioned barrel shape. Cylindrical switch bodies are also possible.

[0016] The rotary switch is particularly preferably a 4-way / 3-way switch, in particular with a mirror-symmetrical structure to a plane in which the rotational axis of the switch extends, i.e., if the rotational axis is vertical, the plane of symmetry is also vertical. Such a symmetrical switch can advantageously open three possible flow paths simply by actuating or switching, so that the direction of a path can be changed simply by switching and without structural differences. This allows identical switches to be used, for example, on the right and left wing of an agricultural machine, which reduces the necessary component diversity.

[0017] Overall, the use of rotary switches not only improves sealing but also reduces the number of moving components and the installation space required.

[0018] In agricultural machines operating according to the method according to the invention, especially with the switches described above, the transition between the conveying air flow and the metering air flow supply to the dispensing units is smooth, so that the pressures present there always remain constant. During the filling process of the dispensing units (switches in the conveying position), the conveying air flow also takes over the entire metering air flow supply.

[0019] In the invention, the switches or their positions are preferably adjustable by servomotors, preferably selectively so that a maximum of one of the switches arranged in series in the conveying air flow line is in the conveying position. In an agricultural machine with several separately supplied sections or partial working widths, this is always one switch per section.

[0020] Preferably, a control system is provided for selectively controlling the switches, ensuring that a maximum of one switch per conveyor line is in the conveying position at any given time. Preferably, the discharge units of the agricultural machine have solids reservoirs. The discharge units can also have fill level sensors or fill level detectors or detection devices that record the contents of the solids reservoirs. Furthermore, the discharge of seed or solids and thus the contents of the reservoir can be determined using counting units. For this purpose, individual particles or conveyor chamber movements can be counted, from which the discharge of seed or solids is calculated. Corresponding information can be used to control the switches. This is intended to prevent overfilling or emptying of the discharge units. Alternatively, other automatic filling systems are also possible, such asTime or pressure controls (sensory or pneumatic self-regulating) possible.

[0021] When the agricultural machine is in operation, the bypass position of the diverters is referred to as the normal position. In this position, all delivery units are supplied with a dosing air flow in parallel via the dosing air flow line and the supply lines. No air flow flows through the conveying air flow line, so no solids are conveyed. As soon as a diverter changes to the conveying position, the dosing air flow in this diverter is at least largely blocked. A conveying air flow begins to flow and conveys solids to the respective delivery unit. If the discharge system is an injector, solids from the solids container are entrained in the conveying air flow. The conveying air flow also provides the required air pressure for dosing to the respective delivery unit.Depending on the solids to be conveyed, it may be sufficient to maintain the diverter's conveying position for only a few seconds. Once the diverter returns to its standard position, i.e., the bypass position, another diverter can be moved to the conveying position if refilling with solids is desired or necessary at another discharge unit.

[0022] The advantages of the invention are primarily its reduced space requirement and improved modularity of the system, allowing it to supply agricultural machines with larger working widths and correspondingly more delivery units to be fed, especially seed drills with a large number of seeding hearts. The invention is by no means limited to single-seed sowing technology, but can also be applied to (multi-stage) volumetric dosing instead of grain singulation.

[0023] Further advantages and details emerge from the dependent claims and an embodiment illustrated in the drawings with details and schematic representations. They show:

[0024] Fig. 1 shows the part of a first embodiment of an agricultural machine relevant to the invention in a perspective view from a traction side,

[0025] Fig. 2 the object from Fig. 1 from behind,

[0026] Fig. 3 is a partial plan view of the subject matter of Figs. 1 and 2, Fig. 4 is a perspective plan view of one of the switches used in the subject matter of Figs. 1 to 3,

[0027] Fig. 5 is a horizontal section through the object of Fig. 4 in bypass position,

[0028] Fig. 6 the object from Fig. 5 in conveying position,

[0029] Fig. 7 is a schematic representation similar to Fig. 3 with illustrated conveying air and dosing air flows and

[0030] Fig. 8 is a schematic circuit diagram of Fig. 7.

[0031] Fig. 9 shows an alternative embodiment of an agricultural machine to Fig. 1 in partial representation,

[0032] Fig. 10 shows a perspective top view of one of the switches used in the embodiment of Fig. 9,

[0033] Fig. 11 the object from Fig. 10 in perspective view from below,

[0034] Fig. 12 the switch body of the switch from Fig. 10,

[0035] Fig. 13 a view of the object from Fig. 12 from below,

[0036] Fig. 14 is a horizontal section through the object of Fig. 10 in bypass

[0037] Position,

[0038] Fig. 15 the object from Fig. 14 in conveying position and

[0039] Fig. 16 the object from Fig. 14 in an alternative conveying position for the

[0040] Fig. 9 shows the left-hand part of the machine frame, not shown in the direction of pull. These illustrations essentially represent specific embodiments. However, the invention is not limited to the illustrated embodiments, but can be modified by a person skilled in the art to adapt it to a specific application.

[0041] Where appropriate, corresponding components are designated with identical reference numerals in all figures. For reasons of clarity, however, not all components appearing multiple times are always provided with reference numerals.

[0042] The embodiment of an agricultural machine for spreading granular solids shown in Figs. 1 to 3 is specifically a precision seed drill. It can be connected to a tractor (not shown) via a drawbar 1. At the same time, the agricultural machine can be operated using external power from the tractor. However, it is also possible to design the agricultural machine to be completely self-sufficient and self-propelled, with its own power supply.

[0043] The machine shown in Figures 1 and 2 has a solids container 2, here designed as a central seed storage unit. It also has a compressed air generation device 3, in this case a blower. The machine shown has eight delivery units 4 in the form of sowing hearts. The machine is divided into two partial widths, namely a left wing L and a right wing R, each carrying four delivery units 4. Each wing is supplied with metering air via a metering air flow line 6 leading from the compressed air generation device 3. In the embodiment shown, the metering air flow line 6 advantageously extends through a machine frame 7. It can be protected within the frame or formed as a hollow space therein and thus requires no additional installation space. A supply line 8 branches off from the metering air flow line 6 to each delivery unit 4. A switch 9 is arranged in each supply line.From the pressure generation device 3, a further air line 11 extends for each wing of the machine to a discharge system 12, in this case an injector, which is connected to the solids container 2. In the injector 12, granular solids, in this case seed, are entrained in the air flow supplied from the air line 11 and transported further in a conveying air flow line 13. The conveying air flow line 13 extends through the switches 9, specifically in the left wing and in the right wing of the machine through four switches 9. These are arranged in series in the conveying air flow line 13, i.e. one after the other, in contrast to the metering air flow line 6, which supplies the switches with the metering air flow in parallel via the supply lines 8.

[0044] Specifically, in the illustrated embodiment, each delivery unit 4 is a double sowing heart from which two rows of seed can be sown. However, this is irrelevant for the supply of the sowing hearts 4 or delivery units. Fig. 4 shows an example of one of the diverters 9 used, which in this case is a 4- / 2-way diverter. A servomotor 17 is arranged outside the housing of the diverter 9. The servomotor 17 is provided with an internal gear. Two actuating shafts extend downwards from the gear into the housing of the diverter 9, which actuate the separating webs / pivoting flaps 16 described below. The servomotor can be driven hydraulically, pneumatically, or electrically, preferably by means of a geared motor and controlled by an internal or external controller. Figs. 5 and 6 show a plan view of the lower part of the diverter in horizontal section in its two functional positions.Dashed arrows symbolize the dosing air flow D, whereas dash-dotted arrows represent the conveying air flow F. Fig. 5 shows the switch 9 in bypass position, also known as the normal or closed position. The connected dispensing unit is supplied with a dosing air flow D via the supply line 8, which here represents the lower part of the switch 9. The conveying air flow F, formed from air and solids, extends through the upper part of the switch. The upper part of the switch is part of the conveying air flow line 13. If none of the switches in the system are open, then there is no conveying air flow F. If a return line or ring line were connected to the end of the last switch, the air flow F would circulate.

[0045] To maintain the bypass position, the switch 9 can be provided with separating webs 16 in the form of pivoting flaps, as shown, which in the bypass position lie against one another in such a sealing manner that essentially no solids can pass from the upper channel into the lower channel in the illustration, ie no solids are transported from the conveying air line 13 into the supply line 8.

[0046] Fig. 6 shows the diverter 9 in the conveying position. The pivoting flaps 16 are shifted in such a way that the conveying air flow F extends through the diverter 9 into the supply line 8, whereas the dosing air flow is blocked and therefore does not flow, or only to a small extent, via the supply line 8 to the dispensing unit in the diverter. Complete airtightness is not required here, since the conveying air flow F already carries air and granular solids. At the last diverter in the conveying flow line of the respective machine wing (diverter 9"" in Fig. 3), the flap 16 facing the outgoing line 13 in Fig. 6 can remain permanently in the position shown there and replace a sealing plug or supplement it in terms of material flow.

[0047] 7 and 8 show schematically (Fig. 7 partially) the supply to the discharge units 4, the right wing of the machine. In Fig. 7 and analogously in Fig. 9, dashed arrows represent clean air, while arrows with a solid border symbolize a conveying air flow F, i.e. air that carries solids with it. Air from the compressed air generation 3 is fed to both the discharge system 12 and the dosing air flow line 6. In the discharge system 12, the air flow entrains solids and thus becomes the conveying air flow F. The dosing air flow D is distributed via the machine frame 7 in parallel via the dosing air flow line 6 to supply lines 8 to the individual discharge units 4. The conveying air flow F runs through the conveying air flow line 13. In doing so, it passes the first switch 9' in Fig. 7 (on the left in the figure), since this switch is in the bypass position. The second switch (in Fig.The (middle) switch 9", however, is switched to the conveying position, so that the conveying air flow F is directed through this switch to the middle delivery unit 4. A dosing air flow D to the middle switch 9", however, does not occur due to this switch position.

[0048] Since the switches are connected in parallel with regard to the dosing air flow D, the third switch 9'" on the right in the figure as well as the fourth switch (no longer shown in Fig. 7) are supplied with dosing air.

[0049] Fig. 8 illustrates this functionality using a circuit diagram in which both options are indicated without specifying which switch 9 is switched and how. The air and air-solid flows in Fig. 8 therefore represent only options and are no longer differentiated according to the individual switches 9, but are previously divided into a conveying air flow F (dotted line) and a dosing air flow D (dashed line).

[0050] Since the illustration in Fig. 9 essentially corresponds to that in Fig. 1, a detailed description of Fig. 9 is unnecessary. However, the switch 9 shown in the following figures is significantly different and is a rotary switch 19. This has four connections, namely connections 13 of the conveying air flow line on both sides, a connection 8e on the bottom which is connected to the compressed air supply via the machine frame 7 and a supply line or outlet 8a from the switch 9, 19 directed to the front right (towards the delivery units) 4 or sowing hearts. Figs. 10 and 11 show the compact housing of the rotary switch 19 and Figs. 12 and 13 show the switch body 21 arranged inside the housing. This is preferably provided with axle journals 22 on both sides and is mounted so as to be rotatable about a rotation axis A indicated in Figs. 10 and 13.A servomotor 17 is arranged outside the housing of the switch 9, which actuates the axle journal 22 and thus the switch body 21 into several positions around the rotation axis A. Preferably, the servomotor 17 is designed as a stepper motor or with an angle sensor, which enables reproducible control and positioning of the switch body 21 in various angular positions. The casing contour, i.e., an imaginary shell enclosing the outer dimensions of the switch body 21, is barrel-shaped. With a corresponding design of the inner contour of the housing of the rotary switch 19, a very good seal can be achieved in a simple manner.

[0051] The switch body 21 has a passage area 13' for a conveying air flow F and, separated therefrom by a rigid inner wall, a supply area 8' extending radially outwards from below, through which the metering air flow D flows. In the illustrated embodiment, the supply area 8' is reinforced by ribs, which simultaneously act to conduct air and counteract turbulence. In Fig. 13, a plane of symmetry E is also indicated, in which the axis of rotation A runs and to which the switch body 21 is constructed mirror-symmetrically. In Figs. 14, 15 and 16, the housing of the rotary switch 19 and the internal switch body 21 are shown in horizontal section through the middle to illustrate the various switching positions of the switch 9, 19. Fig. 14 shows the switch 19 in the bypass position, i.e.the conveying air flow 11 is guided through the illustrated switch to the next switch or to the end of the conveying air flow line 13, while a metering air flow D from the supply line inlet 8e from the general compressed air supply (not shown here) is guided through the switch 9,19 and out of the supply line outlet 8a to the dispensing unit 4.

[0052] In Fig. 15, the switch body 21 is pivoted about its rotational axis A into the conveying position, so that the conveying air flow F enters from the conveying air flow line 13 (left) and is directed from the supply line outlet 8a to the discharge unit 4. Preferably, the pivoting movement of the switch body 21 about its rotational axis A comprises a pivot angle of approximately 135 degrees, counterclockwise as viewed in Fig. 14. The metering air flow D, on the other hand, enters at the bottom at 8e and is forwarded to the next switch via the right-hand conveying air outlet 13.

[0053] Fig. 16 shows the rotary switch 19 also in a conveying position, but in the opposite direction to Fig. 15. In Fig. 16, the conveying air flow F enters through the right inlet of the conveying air flow line 13. This circuit is used for the left-hand part of the agricultural machine, not shown in Fig. 9, in which structurally identical rotary switches 19 can be used as in the right wing R of the machine. In this case, the pivot angle is also approximately 135 degrees, but clockwise as viewed in Fig. 14. The modified circuit is implemented purely in terms of control technology and does not require any different mechanical parts. In the case of angular positions between the conveying air flow line 13 and the supply line outlet 8a that differ from the exemplary embodiment, other pivot angles may be required, likewise at an end rotary switch 19 of a respective wing of the agricultural machine.

[0054] The rotary switch shown is extremely compact and has the switch body 21 as its only moving component, making it less susceptible to failure and repair. However, it can be used exactly as shown schematically in Fig. 8.

[0055] The agricultural machine shown in both versions enables optimized solids discharge with reduced pneumatic energy input. The number and length of hoses are reduced, and thus also the costs. Discrete control of the diverters, with a maximum of one diverter in the discharge position per partial working width of the machine, i.e., per wing, guarantees optimal supply to the discharge units. By using, for example, fill level sensors and utilizing the level information they provide, filling or running dry of the discharge units, in this case the seed drills, can be reliably prevented. Overall, the precision of the machine's operation is increased compared to the state of the art, while simultaneously achieving a more compact and / or more cost-effective design.

[0056] 1 train frame

[0057] 2 solids containers / central seed storage

[0058] 3 Compressed air generation device / blower

[0059] 4 dispensing units / sowing hearts

[0060] 6 Dosing air flow line

[0061] 7 machine frames

[0062] 8 supply lines

[0063] 9 switches

[0064] 11 Air line

[0065] 12 Discharge system / injector

[0066] 13 Conveying air flow line

[0067] 16 dividers / swing flaps

[0068] 17 Actuator

[0069] 19 Rotary switch

[0070] 21 switch bodies

[0071] 22 axle journals

[0072] A rotation axis

[0073] D Dosing air flow

[0074] E plane / plane of symmetry

[0075] F Conveying air flow

[0076] L left wing

[0077] R right wing

Claims

Claims: Agricultural machine for spreading granular solids, in particular seeds, with a pneumatic conveying system for conveying the granular solids from at least one solids container (2) to a number of dispensing units (4), with a compressed air generating device (3) connected to a conveying air flow line (13) and a metering air flow line (6), wherein a supply line (8) branches off from the metering air flow line (6) to each dispensing unit (4), characterized in that a diverter (9) is arranged in each supply line (8) and the conveying air flow line (13) extends through the diverters (9) in series. Agricultural machine according to claim 1, characterized in that the compressed air generating device (3) is formed by a single blower.Agricultural machine according to one of the preceding claims, characterized in that the solids container (2) is connected to the conveying air flow line (13) via a discharge system (12). Agricultural machine according to one of the preceding claims, characterized in that the dispensing units (4) include seed metering units with pressure gradient singulation. Agricultural machine according to any one of the preceding claims, characterized in that the diverters (9) are at least 4-way / 2-way diverters. Agricultural machine according to any one of the preceding claims, characterized in that the diverters (9) are each configured to assume a conveying position or a bypass position and are arranged such that in the conveying position the metering airflow (D) is interrupted and the conveying airflow (F) is directed to the dispensing unit (4), and in the bypass position the conveying airflow (F) is directed through the diverter (9) to the next diverter (9) or stopped. Agricultural machine according to claim 6, characterized in that the diverters (9) have movable separating webs (16) which lie grain-tight against each other in the bypass position and are displaced in the conveying position such that the conveying airflow (F) is directed to the dispensing unit (4) and the metering airflow (D) is interrupted in the diverter (9).Agricultural machine according to claim 6, characterized in that the switches (9) are rotary switches (19). Agricultural machine according to claim 8, characterized in that the rotary switches (19) each have a switch body (21) with a barrel-shaped outer contour. Agricultural machine according to claim 8 or 9, characterized in that the rotary switches (19) are 4-way / 3-way switches, each with one. A diverting body (21) which is mirror-symmetrical to a plane (E) containing the axis of rotation (A) of the rotary diverting device (19). An agricultural machine according to one of the preceding claims, characterized by actuators (17) that actuate the diverting devices (9). An agricultural machine according to one of the preceding claims, characterized in that the dispensing units (4) have a level detection system for detecting the contents of solid material reservoirs of the dispensing units (4). An agricultural machine according to one of the preceding claims, characterized by a control system that selectively controls the position of the diverting devices (9) such that at any given time, at most one diverting device (9) is in the conveying position.Method for spreading granular solids, in particular seeds, onto agricultural land, wherein the granular solids are conveyed from a solids container (2) by means of a pneumatic conveying system to several dispensing units (4) and via these onto the area, and wherein the dispensing units (4) are supplied with a metering air stream (D) by individual supply lines (8) branching off from a metering air stream line (6) to each dispensing unit (4), characterized in that the granular solids can be fed to the dispensing units (4) from a conveying air stream line (F) via individually controllable diverters (9) located in the supply lines (8), wherein the diverters (9) provide a conveying position in which the metering air stream. (D) is blocked and the conveying airflow (F) is directed to the discharge unit (4), or can assume a bypass position in which the conveying airflow (F) is directed through the diverter (9) to the next diverter (9), or, if it is the last diverter (9) in a series, ends there or flows into a return path. Method according to claim 14, characterized in that the diverters (9) are selectively controlled such that at most one diverter (9) is in the conveying position. Method according to claim 14 or 15, characterized in that the change of the positions of a diverter (9) is continuous. Method according to any one of claims 14 to 16, wherein the discharge units (4) have solids reservoirs, characterized in that the contents of the solids reservoirs are determined and the information is used to control the diverters (9).

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