Pneumatic conveying device for granular material and agricultural spreading machine

Description

[0001] The present invention relates to a pneumatic conveying device for granular or granular material, in particular seeds and / or fertilizer, comprising at least one blower with at least one outlet to which a main air supply line is connected, into which an air volume flow generated by the blower flows, wherein the main air supply line opens into an air inlet of an air distribution device for controlling the air volume flow, wherein the air distribution device has a plurality of air outlets, each of which is connected to a connecting line to which a metering device for feeding the granular material is connected. The present invention further relates to an agricultural distribution device.

[0002] Granular materials, such as seeds or fertilizer, are typically transported from at least one storage container to one or more dispensing units by means of a conveying device. Mechanical or pneumatic conveying devices are used for this purpose. Pneumatic conveying devices use a blower to transport the granular material through connecting lines from the storage container, for example, via a distribution device and a number of lines connected thereto, to the respective dispensing units. The feed of the granular material from the at least one storage container into the conveying device is controlled by a metering device. Conveying devices for granular materials are known, for example, from US 2008 / 295751 A1, US 7,669,538 B2, US 5,979,343 A, and US 2021 / 127556 ​​A1.

[0003] A pneumatic conveying device of the type mentioned above, as well as an agricultural distribution device, is known from US 4,779,765 A. An air volume flow generated by a blower is divided into two air supply lines, which are used for transporting granular material that is fed to the respective air supply line by metering devices designed as metering rollers.

[0004] The invention is based on the objective of further developing a pneumatic conveying device of the type mentioned above, which is characterized by a flexible adjustment of the air delivery quantities supplied from the air outlets while maintaining a compact design, particularly in the longitudinal direction of the distribution device.

[0005] This problem is solved by a pneumatic conveying device with the features of independent claim 1. Advantageous embodiments and further developments are described in the dependent claims. Furthermore, the problem is solved by an agricultural distribution device according to claim 15.

[0006] According to claim 1, a pneumatic conveying device for conveying granular material, in particular seeds and / or fertilizer, is proposed, comprising a blower with at least one outlet to which at least one main air supply line is connected, into which an air volume flow generated by the blower flows, wherein the at least one main air supply line opens into an air inlet of an air distribution device for controlling the air volume flow, wherein the air distribution device has a preferably even number or a number divisible by three number of air outlets, to each of which a connecting line is connected, to which a metering device for supplying the granular material is connected.According to the invention, the air distribution device is designed as a cylindrical housing with a rotary slide arranged therein, which is set up to change an outlet cross-section of the air outlets in order to manipulate the supplied air volume flow for the transport of the granular material coming from the respective metering device.

[0007] The invention is based on the concept of being able to adapt the airflow to different operating conditions. In particular, a compact design can be achieved by integrating the rotary valve, which is designed to change the outlet cross-section of the air outlets (especially those that are essentially circular), into the housing. Furthermore, the rotary valve enables a targeted distribution of the airflow to the air outlets, ranging from completely supplying all air outlets to limiting the airflow to half or one-third of the outlets. Various intermediate distributions into partial airflows are possible.

[0008] Preferably, an actuator can be arranged on the rotary valve, allowing it to be operated manually or automatically. The actuator can, for example, be an electric motor that changes the position of the rotary valve relative to the air outlets. Alternatively, the actuator can be a lever that is operated manually by a person.

[0009] In particular, the rotary valve can be designed as an arc-shaped section pivotable about a longitudinal axis of the housing, which has recesses extending circumferentially along its arc. These recesses interact with the housing's air outlets depending on the set pivot position of the arc-shaped section. The arc-shaped section is arranged concentrically within the housing, so that the longitudinal axis also serves as the pivot axis of the rotary valve. By pivoting the arc-shaped section, the recesses can be adjusted relative to the air outlets, ranging from completely uncovered (i.e., the recesses completely covering each air outlet) to partially covering half of the air outlets with the rotary valve's outer surface.In the first case of complete coverage, the air volume flow supplied by the blower is distributed essentially uniformly to all air outlets. In the case of only partial coverage, the distribution of the supplied air volume flow can be varied depending on the set swivel angle of the arc-shaped section around its swivel axis, which runs coaxially to the longitudinal axis of the housing.

[0010] Preferably, the rotary valve can be adjustable in discrete steps or continuously. Adjusting the rotary valve in discrete steps has the advantage that predefined ratios of the supplied airflow to the air outlets can be set. Continuous adjustment of the rotary valve allows for more precise adjustment of the supplied airflow to the air outlets. For setting the ratio of the supplied airflow distribution in discrete steps, the actuator, designed as a lever, can be locked in detent positions on the housing. A locking mechanism can be provided for this purpose. Alternatively, the electric motor can be designed as a stepper motor, which also allows for setting the ratio in discrete steps.

[0011] Preferably, the housing can have a circular cylindrical shape, resulting in a more compact design of the air distribution device. In particular, the housing is arranged transversely to the main air supply line and the connecting lines attached to the air outlets, which at least partially run essentially in a common direction. This arrangement of the housing transversely to the connecting lines has the advantage of providing more installation space for the metering devices.

[0012] Preferably, the recesses in the circumferential direction of the section may have an extension that corresponds to at least twice the diameter of the outlet cross-section of the air outlets.

[0013] Furthermore, the recesses can have a width in the axial direction that is at least equal to or less than the diameter of the outlet cross-section of the air outlets. By reducing the outlet cross-sections of some of the recesses, for example, less pronounced or differing flow resistances in downstream ducts of varying lengths can be compensated for.

[0014] In a particular embodiment, the recesses near a main air supply line can have a smaller opening cross-section or a narrower width than recesses located further away from the main air supply line. This embodiment reduces increased airflow, such as that occurring in the immediate vicinity of the main air supply line, in order to achieve a more uniform airflow in all of the air outlets.

[0015] In particular, the recesses can have a substantially elliptical opening cross-section. An elliptical opening cross-section is understood to mean, in particular, one that has a different width and extent along the circumferential direction, such as an elongated hole.

[0016] Preferably, the recesses, viewed circumferentially from the rotary valve, can be arranged with an alternating circumferential offset from one another. The opening cross-sections of two immediately adjacent recesses have a common circumferential overlap area.

[0017] According to a preferred embodiment, the air outlets can be arranged side by side on the housing, parallel to its longitudinal axis. This simplifies the installation and routing of the connecting lines. It also simplifies the connection of the metering devices to the connecting lines.

[0018] In particular, the at least one main air supply line can be arranged opposite the air outlets on the housing or coaxially with the housing. The main air supply line and the connecting lines to the air outlets can thus be arranged section by section in a common plane, which also has a positive effect on the installation space required for the pneumatic conveying device. The main air supply line can be arranged symmetrically or asymmetrically on the housing with respect to its center. A coaxial connection of the main air supply line to one end of the housing is particularly advantageous if the housing also forms a component, preferably a load-bearing component, of a machine frame.

[0019] According to a further development, the air outlets can be arranged in pairs side by side or in groups of three, wherein the distance between the air outlets of at least one pair or group of three is less than the distance to an adjacent pair or group of air outlets. A group arrangement of ducts and thus their associated air outlets is particularly advantageous when metering devices are cascaded downstream.

[0020] In particular, each pair of air outlets can be followed by two metering devices in the conveying direction, wherein both metering devices can be connected to both connecting lines assigned to the respective air outlets in order to selectively supply the material of one metering device or of both metering devices to one connecting line or to both connecting lines.

[0021] Each dosing device can have a manually or actuator-operated switching element that connects or disconnects the respective dosing device from one or both connecting lines. For example, the dosing devices can have switching elements designed as changeover flaps, allowing material to be fed alternately to only one or both connecting lines. The dosing devices themselves are switchable, so that all connecting lines can be supplied with material from only half of the dosing devices.

[0022] Furthermore, the problem posed at the outset is solved by an agricultural distribution machine for conveying granular material taken from at least one storage container, using a pneumatic conveying device designed according to any one of claims 1 to 14. Reference may be made to all descriptions of the proposed pneumatic conveying device.

[0023] The present invention is explained in more detail below with reference to an embodiment illustrated in the drawings.

[0024] They show: Fig. 1 a schematic representation of a towing vehicle and an agricultural spreading machine; Fig. 2 a partial view of a pneumatic conveying device; Fig. 3 a perspective partial view of the pneumatic conveying device according to Fig. 2 Fig. 4 a perspective view of an air distribution device; Fig. 5 a schematic partial sectional view of the air distribution device according to Fig. 4 in a first exemplary switching position; Fig. 6 a schematic partial sectional view of the air distribution device according to Fig. 4 in a second exemplary switching position; Fig. 7 a schematic partial sectional view of the air distribution device according to Fig. 4 in a third exemplary switching position; and Fig. 8 a schematic partial sectional view of the air distribution device according to Fig. 4 in a fourth exemplary switching position.

[0025] In Fig. 1Figure 1 shows a schematic representation of a towing vehicle 1, in particular a tractor, and an agricultural spreading machine 2 mounted on it. The towing vehicle 1 serves to move the spreading machine 2 across an area to be cultivated in one direction and to supply it with drive energy. Two supply lines 3 are shown only as examples; these provide hydraulic fluid and / or electrical energy to drive a blower 5, in particular a hydraulically driven blower, of a pneumatic conveying device 4 of the spreading machine 2. The spreading machine 2 has a hopper 6, which is divided into two segments 6a and 6b by a partition 7. Alternatively, two separate hoppers 6 can be provided. The hopper 6 contains granular material, in particular seed and / or fertilizer, which is spread by the spreading machine 2.The granular material is conveyed by the pneumatic conveying device 4 to dispensing units 8 and 9, which distribute the granular material into the soil. Each dispensing unit 8 can have one or more seed coulters, and each dispensing unit 9 has one or more fertilizer coulters. An even number or a number divisible by three of dispensing units 8 and 9 is provided.

[0026] The blower 5 is provided with at least one outlet 10, to which at least one main air supply line 11 is connected, into which an air volume flow 12 generated by the blower 5 flows. The at least one main air supply line 11 opens into an air inlet 13 of an air distribution device 14 for dividing the air volume flow 12. The air distribution device 14 has an even number of air outlets, each of which is connected to a connecting line L1, L2, ..., L8.

[0027] The granular material from the individual segments 6a, 6b of the storage container 6 is fed to the individual connecting lines L1, L2, ..., L8 of the conveying device 4 by means of metering devices 16. The metering devices 16 ensure precise metering of the quantity of material to be conveyed from the conveying device 4 to the dispensing units 8, 9. The metering devices 16 are arranged below the storage container 6, between the storage container 6 and the connecting lines L1, L2, ..., L8 of the conveying device 4. According to the [reference to the diagram] Fig. 1In the agricultural distribution machine 2 shown, the granular material is fed from the respective segments 6a, 6b of the storage container 6 to the respective metering device 16 primarily by gravity. The metering devices 16 can be divided into two or more groups G1, G2, each group G1, G2 comprising a number of metering devices 16 corresponding to half the number of connecting lines L1, L2, ..., L8. Group G1 with metering devices 16 is arranged directly behind the air distribution device 14. Group G2 with metering devices 16 is arranged downstream of the air distribution device 14 in the conveying direction FR of the granular material.

[0028] The connecting lines L1, L3, L5 and L7 can be assigned to group G2, to which the pneumatically conveyed seed is supplied by the metering devices 16 of group G2. The connecting lines L2, L4, L6 and L8 can be assigned to group G1, to which the pneumatically conveyed fertilizer is supplied by the metering devices 16 of group G1.

[0029] In Fig. 2 Figure 4 shows a partial view of the pneumatic conveying device 4 from above. The illustration in Fig. 3 shows a perspective partial view of the pneumatic conveying device 4 according to Fig. 2 .

[0030] The air distribution device 14 comprises a cylindrical housing 17. The housing 17 of the air distribution device 14 is arranged transversely to the main air supply line 11 and the connecting lines L1, L2, ..., L8 connected to the air outlets 15, which at least partially run substantially in a common direction. The connecting lines L1, L2, ..., L8 run longitudinally along the distribution machine 2 in sections. Preferably, the housing 17 has a circular cylindrical shape. The arrangement of the air distribution device 14, oriented transversely to the longitudinal axis of the distribution machine 2, enables a space-optimized arrangement of this device and other components of the pneumatic conveying device 4, such as the blower 5, which is particularly advantageous because Fig. 1 becomes clear.

[0031] The representation in Fig. 4Figure 1 shows a perspective view of the air distribution device 14. The air distribution device 14 is designed as the cylindrical housing 17 with a rotary valve 20 arranged therein, as shown in the following figures. Figs. 5 to 8This will be explained in more detail below. The rotary valve 18, arranged in the housing 17, is designed to change the outlet cross-section of the air outlets 15 in order to manipulate the supplied air volume flow 12 for transporting the granular material coming from the respective metering device 16. To actuate the rotary valve 18, an actuator designed as a lever 19 is pivotably attached to the rotary valve 18 about a pivot axis 21 coaxial with the longitudinal axis 20 of the housing 17. To fix the rotary valve 18 in a defined position, a ring-segment-shaped section 22 is arranged on the outside of the housing 17 adjacent to the lever 19. The ring-segment-shaped section 22 has recesses 23, for example in the form of elongated holes, extending radially in the direction of the pivot axis 21.At the free end of the lever 19 is a locking lug (not shown) which can be engaged with one of the recesses 23 to position the rotary valve 18 in a desired position. Depending on the position of the lever 19 or the rotary valve 18, the air volume flow 12 is divided into partial volume flows 28, 29, which will be explained in more detail below.

[0032] In Fig. 5 is a schematic partial sectional view of the air distribution device 14 according to Fig. 4The rotary valve 18 is shown in a first switching position. The rotary valve 18 is designed as a circular arc-shaped section 24 that can pivot about the longitudinal axis 20 of the housing 17. Both the housing 17 and the rotary valve 18, or its circular arc- or cylindrical segment-shaped section, can also be designed as a polygonally bent sheet metal blank. In this case, the number of bends approximates a circle as closely as possible, like a polygon. The circular arc-shaped section 24 has recesses 25 extending circumferentially along its length. These recesses interact with the air outlets 15 of the housing 17, depending on the set position, i.e., the pivot angle set by the actuator, of the circular arc-shaped section 24. At least one sector-shaped section 26 is arranged at the end of the circular arc-shaped section 24 in the axial direction.The circular sector-shaped section 26 pivotally mounts the circular arc-shaped section 24 to the housing 17 of the air distribution device 14. The lever 19 engages one of the two circular sector-shaped sections 26 in a rotationally fixed manner, enabling it to pivot together with the circular arc-shaped section 24 about the pivot axis 21 in the pivot direction 27.

[0033] The rotary valve 18 can be, as in the Figs. 4 to 8The rotary valve 18 can be adjusted in discrete steps in the direction of rotation 27, in particular manually. The step size, i.e., the circumferential distance between the recesses 23, determines the ratio of the distribution of the supplied air volume flow 12. Alternatively, the rotary valve 18 can be continuously adjustable. For this purpose, an actuator, for example an electric motor, can be arranged on one of the circular sector-shaped sections 26. In particular, the actuator, designed as an electric motor, can effect automatic adjustment. Thus, a control command can be generated by a control unit of the towing vehicle 1 or the distribution machine 2, which serves to control the actuator in order to set a rotation angle that corresponds to a ratio of the distribution of the air volume flow 12 into the partial volume flows 28, 29 specified by an operator.

[0034] The recesses 25 have a circumferential extent L of the arc-shaped section 24, which is at least twice the diameter D of the outlet cross-section of the air outlets 15. The recesses 25 have an axial width B, which is at least equal to the diameter D of the outlet cross-section of the air outlets 25. Preferably, the recesses 25 have a substantially elliptical opening cross-section.

[0035] The recesses 25 are arranged with alternating circumferential offsets to one another in the circumferential direction of the rotary valve 18 or the circular arc section 24, respectively. The air outlets 15 are arranged side by side on the housing 17, parallel to its longitudinal axis 20. The air outlets 15 are arranged in pairs, with the distance between the air outlets 15 of a pair being less than the distance to an adjacent pair of air outlets 15. In the illustrated embodiment, four air outlets 15, with connecting lines L8, L7, L6, L5 attached to them, are arranged in groups at the same axial distance from one another. The other four air outlets 15, with connecting lines L1, L2, L3, L4 attached to them, are also arranged in groups at the same axial distance from one another.There is a greater axial distance between the central air outlets 15, to which the connecting lines L5 and L3 are attached. Furthermore, the air outlets 15 with the connecting lines L8, L7, L6, L5 can be arranged symmetrically to the air outlets 15 with the connecting lines L1, L2, L3, L4. This offers advantages in hose routing. Each pair of air outlets 15 is assigned two correspondingly arranged recesses 25 of the arc-shaped section 24, with the recesses 25 extending in opposite directions in the circumferential direction, i.e., they are offset from each other. Each pair of recesses 25 assigned to a pair of air outlets 15 has a common overlap area in which both air outlets 15 of a pair are completely open, as shown in the figure. Fig. 5 visible.

[0036] In Fig. 5As a representative example for all paired air outlets 15, the division of the air volume flow 12 into two proportional partial volume flows 28 and 29 by the rotary valve 18 is shown for one pair of air outlets 15. The lever 19 is in a central position in which all air outlets 15 are fully open through the recesses 25. Accordingly, the supplied air volume flow 12 is distributed evenly to all air outlets 15, with each of the connecting lines L1, L3, L5 and L7 as well as L2, L4, L6 and L8 being supplied with equal partial volume flows 28 for fertilizer and partial volume flows 29 for seed, respectively. With respect to the paired air outlets 15, the air volume flow 12 is divided in a ratio of essentially 50:50.

[0037] The representation in Fig. 6 shows a schematic partial sectional view of the air distribution device 14 according to Fig. 4In a second exemplary switching position. As can be seen from the position of the lever 19, the rotary valve 18 was moved in a pivoting direction 27 in which the air outlets 15, to which the connecting lines L1, L3, L5 and L7 are connected, are essentially covered by the outer surface of the rotary valve 18, while the air outlets 15, to which the connecting lines L2, L4, L5 and L8 are connected, remain completely open. With respect to the paired air outlets 15, the air volume flow 12 is divided into the respective partial flows 28 and 29 in a ratio of approximately 90:10.

[0038] In Fig. 7 is a schematic partial sectional view of the air distribution device according to Fig. 4This is shown in a third exemplary switching position. As can be seen from the position of the lever 19, the rotary valve 18 has been moved in a pivoting direction 27 in which the air outlets 15, to which the connecting lines L1, L3, L5 and L7 are connected, remain fully open, while the air outlets 15, to which the connecting lines L2, L4, L5 and L8 are connected, are partially covered by the outer surface of the rotary valve 18. With respect to the paired air outlets 15, the air volume flow 12 is divided into the respective partial flows 28 and 29 in a ratio of approximately 30:70.

[0039] The representation in Fig. 8 shows a schematic partial sectional view of the air distribution device 14 according to Fig. 4In a fourth exemplary switching position. As can be seen from the position of the lever 19, the rotary valve 18 was moved in a pivoting direction 27 in which the air outlets 15, to which the connecting lines L2, L4, L6 and L7 are connected, are essentially covered by the outer surface of the rotary valve 18, while the air outlets 15, to which the connecting lines L1, L3, L5 and L7 are connected, remain completely open. With respect to the paired air outlets 15, the air volume flow 12 is divided into the respective partial flows 28 and 29 in a ratio of approximately 10:90.

[0040] As already explained above, the exemplary setting options were in the Figs. 5 to 8The adjustment of the actuator, designed as a lever 19, in discrete steps around the pivot axis 21 in the pivot direction 27 is described. Stepless adjustment using an actuator designed as an electric motor is also conceivable, which, in addition to automating the adjustment, allows for finer gradations in the distribution of the respective partial currents 28 and 29. Reference symbol list 1 Towing vehicle 28 Partial volume flow 2 Distribution machine 29 Partial volume flow 3 Supply line B Width of 25 4 Conveyor D Diameter of 15 5 fan L Extension of 25 6 Storage container FR Direction of flow 6a segment G1 group 6b segment G2 group 7 partition L1 Connection line 8 Delivery unit L2 Connection line 9 Delivery unit L3 Connection line 10 Outlet L4 Connection line 11 Main air supply line L5 Connection line 12 Air volume flow L6 Connection line 13 air intake L7 Connection line 14 Air distribution device L8 Connection line 15 air outlet 16 Dosing device 17 Housing 18 Rotary valve 19 lever 20 Longitudinal axis 21 Swivel axis 22 Ring segment-shaped section 23 recess 24 Arc-shaped section 25 Exclusion 26 circular sector-shaped section 27 direction of rotation

Claims

1. A pneumatic conveying device (4) for conveying granular material, in particular seeds and / or fertiliser, including at least one blower (5) having at least one outlet (10), to which at least one main air supply line (11) is connected, into which flows an volumetric air flow (12) generated by the blower (5), wherein the at least one main air supply line (11) leads into an air inlet (13) of an air distribution device (14) for controlling the volumetric air flow (12), wherein the air distribution device (14) has a number of air outlets (15) that are even or divisible by 3, to which a connecting line each (L1, L2, L3, ... L8) is connected, to which a metering device (16) for supplying the granular material is connected, wherein the air distribution device (14) is embodied as a cylindrical housing (17) with a rotary slide valve (18) arranged therein, which is equipped for changing an outlet cross-section of the air outlets (15) in order to manipulate the supplied volumetric air flow (12) for transporting the granular material coming from the respective metering device (16).

2. The pneumatic conveying device (4) according to Claim 1, characterised in that on the rotary slide valve (18) an actuator (19) is arranged, through which the rotary slide valve (18) is manually or automatically actuatable.

3. The pneumatic conveying device (4) according to Claim 1 or 2, characterised in that the rotary slide valve (18) is adjustable in discrete steps or continuously.

4. The pneumatic conveying device (4) according to any one of the Claims 1 to 3, characterised in that the housing (17) has a circular-cylindrical shape.

5. The pneumatic conveying device (4) according to any one of the preceding claims, characterised in that the rotary slide valve (18) is embodied as an arcuate section (24) pivotable about a longitudinal axis (20) of the housing (17), which comprises recesses (25) extending in the circumferential direction of the section (24) in sections, which depending on a set pivot position of the arcuate section (24), interact with the air outlets (15) of the housing (17).

6. The pneumatic conveying device (4) according to Claim 5, characterised in that the recesses (25) in the circumferential direction of the section (24) have an extent (L) which corresponds at least to twice a diameter (D) of the outlet cross-section of the air outlets (15).

7. The pneumatic conveying device (4) according to Claim 5 or 6, characterised in that the recesses (25) in the axial direction have a width (B) which corresponds at least to the diameter (D) of the outlet cross-section of the air outlets (15) or is less than this.

8. The pneumatic conveying device (4) according to any one of the Claims 5 to 7, characterised in that the recesses (25) in the vicinity of a main air supply line (11) have a smaller opening cross-section or a smaller width (B) than recesses (25) further distant from the main air supply line (11).

9. The pneumatic conveying device (4) according to any one of the Claims 5 to 7, characterised in that the recesses (25) have a substantially elliptical opening cross-section.

10. The pneumatic conveying device (4) according to any one of the Claims 5 to 8, characterised in that the recesses (25), seen in the circumferential direction of the rotary slide valve (18), are arranged with an alternating offset in the circumferential direction relative to one another.

11. The pneumatic conveying device (4) according to any one of the Claims 1 to 9, characterised in that the air outlets (15) are arranged axially parallel to the longitudinal axis (20) of the housing (17) next to one another on the same.

12. The pneumatic conveying device (4) according to Claim 10, characterised in that the at least one main air supply line (11) is arranged located opposite the air outlets (15) on the housing (17) or coaxially to the housing (17).

13. The pneumatic conveying device (4) according to Claim 10 or 11, characterised in that the air outlets (15) are arranged in pairs next to one another or in a group of three, wherein the distance of the air outlets (15) among at least one pair or one group is smaller than the distance to an adjacent pair or a group of air outlets (15).

14. The pneumatic conveying device (4) according to Claim 12, characterised in that two of the metering devices (16) each are arranged downstream in the conveying direction (FR) of each pair of air outlets (15), wherein both metering devices (16) are connectible to both connecting lines (L1, L2, L3, ... L8) assigned to the respective air outlets (15) in order to optionally supply the material of a metering device (16) or both metering devices (16) to a connecting line (L1, L2, L3, ... L8) or both connecting lines (L1, L2, L3, ... L8).

15. The pneumatic conveying device (4) according to Claim 13, characterised in that each metering device (16) comprises a change-over element actuatable manually or by an actuator, which connects or disconnects the respective metering device (16) to / from one or both connecting lines (L1, L2, L3, ... L8) .

16. An agricultural distribution machine (2) for conveying granular material taken from at least one storage container (6) having a pneumatic conveying device (4) according to any one of the Claims 1 to 14.