Disc-shaped piece for seeding and seeding unit for pneumatic seeding machine and pneumatic seeding machine

Abstract

The utility model relates to a seeding disc-shaped piece and a seeding unit for a pneumatic seeding machine and the pneumatic seeding machine, the seeding disc-shaped piece comprises a disc-shaped component, and at least one circle of looped through holes are formed in the disc-shaped component. A seed side and an air side opposite to each other are defined in the disc member such that as the circumferential portion including the through-holes enters the bowl with respect to the loose seed, the seeding disc is introduced into the bowl, the seed is held by each of the through-holes at the seed side due to the effect of a pneumatic pressure difference between the seed side and the air side. The disc-shaped member includes at least one seed holding bracket portion adjacent to the through-hole at the seed side at the radially innermost side with respect to the corresponding through-hole. The seed holding bracket portion is provided at least angularly corresponding to some of the through holes, and extends in the circumferential direction so as to at least partially offset the weight of the loose seed located on the seed held by the through holes when the disc is introduced into the bowl with respect to the loose seed.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of disk for precision pneumatic seeding machine. BACKGROUND

[0002] In the seeding unit of precision agricultural seeding machine, it is known to use a disk provided with one or more rings of concentric holes, which are used to pneumatically draw one seed per hole and deliver the drawn seed to a duct for the seed to be released at the delivery duct. The term "hole" in the following is intended to indicate any shape of through opening capable of pneumatically attracting and retaining a seed to be dispensed on one side of the disk. The definition of hole is therefore extended to non-cylindrical shapes and geometries suitable to perform the described function.

[0003] A typical seeding machine of this type is described, for example, in US9338939B1, US6176393B1, US6932236B2, US7448334B2 or EP3888434A2.

[0004] US6176393B1 describes in particular a seeding disk suitable for spreading fine seeds, which has a screen or grill mounted in the area of the ring of holes against which the seeds are pneumatically attracted. In one of the examples described, the grill is held in a removable manner by means of a seal which, together with the peripheral edge of the grill, is received in a corresponding peripheral cavity. The cavity has this single function and is therefore limited to the minimum radial size necessary to hold the grill, in addition to being always occupied during use by the edge of the grill and the corresponding seal.

[0005] US7448334B2 describes a flat disk-type circular seed disk provided with a series of seed-drawing orifices arranged peripherally. The orifices are spaced along a peripheral edge axially offset with respect to the rest of the disk to access a seed release position and the features of a cell-type seed disk. This offset requires the portion of the disk containing the openings to be mounted raised with respect to the base mounting plane of the disk, the only purpose of which is to allow the seeds to fall into the correct position of the seed duct.

[0006] EP3888434A2 describes a seed metering disk in which a seed agitator, for example an agitator pocket, can be located on the seed side of the disk. The only function of the agitator pocket is to agitate the seeds located in the seed pool.

[0007] The seed plates with known configuration present many problems in the phases of picking up the seeds and relative conveying towards the seed dispensing duct. In fact, in the phase of picking up the seeds, when the segments of holes in a circle travel in a condition of immersion in the loose seeds present in the seed pick-up chamber, the weight of the seeds that overlap the seeds kept above the holes (kept seeds) is supported on the kept seeds, thus possibly affecting the keeping of the kept seeds. This factor limits the rotation speed of the plate, thus allowing a sufficient separation precision. In addition to this limited speed, the sowing precision is also affected.

[0008] Furthermore, when one or more seeds fall from the respective holes of the plate, a drop in the pressure for keeping the seeds occurs due to the greater air flow allowed by the free holes of the plate. This causes a further fall of the seeds from the holes of the plate and an increase in the propagation of malfunctions of the seeds deposited on the ground. At most, a so-called stalling condition is reached, in which all the seeds fall from the plate due to the effect of the insufficient pressure difference established between the seed side and the air side of the plate.

[0009] It must be considered that modern seeders use a large number of sowing units and each unit is subjected, during use, to impacts, shocks, vibrations and similar damaging phenomena that certainly do not favour the keeping of the seeds on the holes of the seed plate. It is therefore necessary to reinforce the pneumatic system of these seeders to take into account the above-mentioned damaging phenomena and problems. This involves an increase in the construction costs of the machine, a lower overall energy efficiency level and, in any case, a risk of malfunctions. SUMMARY

[0010] The technical problem solved by the present utility model is to provide a seed plate that is structured in terms of structure and function to overcome at least some of the drawbacks set out with reference to the cited prior art.

[0011] With regard to this problem, the object of the present utility model is to provide a seed plate that can provide a better keeping of the seeds to be conveyed, a reduction in the weight of the seeds around the kept seeds and a significant limitation of the possibility of stalling.

[0012] Another object is to provide a seed plate that allows a greater rotation speed without affecting the sowing precision.

[0013] The problem is solved and at least some of the objects are at least partially achieved by the seed plate structured according to one or more of the features of the present utility model.

[0014] According to a first aspect of the present utility model, a discoid member for a pneumatic seed drill comprises at least one ring of holes. Preferably, a seed side and an air side are defined in the discoid member opposite to each other, such that as a circumferential portion comprising one or more rings of holes enters the bowl about loose seeds, the discoid member, when introduced into the bowl about loose seeds, holds seeds by each hole of the one or more rings at the seed side due to a pressure difference between the seed side and the air side.

[0015] Preferably, the discoid member comprises at least one seed-holding bracket adjacent to the one or more rings of holes at the seed side, preferably adjacent to the one or more rings of holes at the seed side radially inside with respect to the respective ring of holes. Preferably, the bracket is at least provided angularly corresponding to some of the holes, and the bracket preferably extends circumferentially such that, when the discoid member is introduced into the bowl about loose seeds, the bracket at least partially counteracts the weight of loose seeds on the seeds held by the ring of holes.

[0016] In this way, the seeds combined with the discoid member in the area of the respective hole do not bear weight, and the interaction with loose seeds above the seeds in the bowl about loose seeds is limited, resulting in a more effective holding of the seeds in the respective hole until the held seeds are discharged from the bowl about loose seeds.

[0017] Preferably, the bracket is separate from the holes of the ring of holes.

[0018] Preferably, for each hole of the discoid member, one bracket is provided angularly corresponding to the respective hole, or for each pair of holes, one bracket is provided angularly corresponding to the respective pair of holes. This arrangement improves the above-mentioned effects.

[0019] In an important aspect of the present utility model, the bracket is at the base of a recess or indentation recessed into the surface of the discoid member. This avoids a protrusion upward from the regular surface of the discoid member.

[0020] Preferably, the recess or recessed indentation is not through, that is, the recess or recessed indentation is not a through hole. Preferably, the recess or recessed indentation extends circumferentially to at least partially form an annular cavity, and even more preferably, the annular cavity is continuous.

[0021] In some embodiments, the radial dimension of the annular cavity is not less than the radial dimension of the holes. Preferably, the maximum radial dimension of the annular cavity is not less than the radial dimension of each of the holes of the circle of holes. In other words, the annular cavity has a dimension similar to the dimension of the seeds. This is in line with the abovementioned mitigating effect. It should be noted that, in the present context, the term "radial dimension of each hole" preferably means the dimension measured in the radial direction of the disc-shaped member of each hole (that is to say, for example, the diameter of each hole).

[0022] Preferably, the radial dimension of the annular cavity and the radial dimension of the holes are of the same order of magnitude, that is to say, the ratio between the radial dimension of the annular cavity and the radial dimension of the holes is between 0.1 and 10. Even more preferably, the ratio between the radial dimension of the annular cavity and the radial dimension of the holes is between 0.5 and 5. These features optimize the effectiveness of the seed- retaining cradle portion, while maintaining the structural rigidity of the disc.

[0023] Preferably, the annular cavity is separate from the holes of the circle of holes.

[0024] The annular cavity is preferably a single cavity. More preferably, on the disc, the annular cavity is radially closer to the inside than the holes of the circle of holes, but is adjacent to the holes of the circle of holes.

[0025] In one embodiment of the application, there is a seed agitating device associated with the annular cavity, which agitating device preferably comprises a plurality of recesses, the plurality of recesses extending in the disc-shaped member with a thickness comparable to the thickness of the annular cavity, and the plurality of recesses preferably pointing radially towards the central portion of the disc. These radial recesses contribute to the agitation of the seeds in the seed pick-up chamber.

[0026] In a preferred embodiment, the annular cavity has a depth, in particular an axial depth, of between 5% and 90% relative to the thickness of the disc-shaped member.

[0027] The application also relates to a seeding unit for a pneumatic seeder, comprising a disc as described above having one or more of the abovementioned characteristics, and to a pneumatic seeder comprising a carrier structure and a plurality of the abovementioned seeding units engaged with the carrier structure. BRIEF DESCRIPTION OF DRAWINGS

[0028] The features and advantages of the application will be better understood through the following detailed description of preferred but non-limiting embodiments thereof, given by way of non-limiting examples, with reference to the drawings in which:

[0029] - Figure 1 is a front view of a disc for seeding constructed in accordance with the application;

[0030] - Figure 2 isFigure 1 Details of the disc-shaped component in a radial section along section line II-II;

[0031] - Figure 3 yes Figure 1 Detailed cross-sectional view of the disc-shaped component along section line III-III;

[0032] - Figure 4 This is a schematic diagram of the seeding unit of the precision pneumatic seeder according to the present invention;

[0033] - Figure 5 This is a schematic diagram of a precision pneumatic seeder based on this utility model;

[0034] - Figures 6a to 6f This is a schematic diagram showing details of a disc-shaped component for sowing according to an embodiment of the present invention;

[0035] - Figure 7 This is a partial perspective view of the seeding disc according to the present invention, depicting the seeding disc in a state in which seeds are present on its surface;

[0036] - Figure 8 This is a perspective view showing details of a seeding disc according to another embodiment of the present invention. Detailed Implementation

[0037] In the accompanying drawings, the disc-shaped member for sowing constructed according to the present invention is generally indicated by 1. The disc-shaped member 1 is arranged in the housing 20 of the sowing unit 2. The pneumatic seeder 200 according to the present invention may include a plurality of sowing units 2 that are engaged with the support structure 21.

[0038] Preferably, the seeding disc 1 defines and separates two regions within the housing 20 of the seeding unit in a manner known per se, establishing a pressure difference between the two regions. Preferably, the first region 3 faces the seed side 4 of the disc and contains a certain number of seeds to be distributed. The first region 3 may constitute a seed collection chamber, as more preferably described below. Preferably, the second region 5 faces the air side 6 of the disc 1, and advantageously, a lower pneumatic pressure is established in the second region 5 than in the first region 3.

[0039] Preferably, the holes 7 of the circle (but more than one circle, if applicable) allow the passage of air between the first region 3 and the second region 5, the circle being concentric with the rotation axis X of the disc and the holes passing through the disc itself. The disc is introduced into the seeds contained in the pick-up chamber of the first region 3 by rotating around the axis X and, due to the pressure difference between the first region and the second region, the seeds remain coupled to each hole, in particular to each hole on the seed side, to convey the seeds by the disc towards the delivery duct 8, in which the vacuum-breaking device 9 (for example, by means of a block or a roller) closes the respective hole, thus creating an interruption of the pressure difference and therefore causing the seeds to fall into the duct 8.

[0040] In some embodiments, the holes 7 of the circle comprise a ring 12 that is frustoconical starting from the seed side 4 towards the air side 6, which protrudes towards the axis of the hole 7, preferably ending with a lip 13, followed by a widening 31 of the hole, which preferably extends to the air side 6 of the disc.

[0041] Preferably, behind the holes 7 of the circle, an annular cavity 14 is formed. The annular cavity 14 is preferably concentric with respect to the holes 7 of the circle and is preferably closed in a continuous circle. In some embodiments, the annular cavity 14 is formed at the seed side of the disc at least at the radially innermost side with respect to the holes of the circle. The annular cavity 14 is preferably a single cavity (example of Figures 1 to 3 、 Figure 6d 、 Figure 6e ), however, it can also be provided that there are a plurality of concentric grooves (example of Figure 6b 、 Figure 6c ) located radially inside or outside the holes of the circle.

[0042] The function of the annular cavity 14 is to lighten the weight of the seeds present in the pick-up chamber (region 3) next to the seeds (loose seeds) to be held on the respective holes 7, as shown in the example of Figure 7 . The lightening effect is mainly due to the fact that the edge 16 of the annular cavity close to the holes 7 of the circle defines (and performs the seed containment function) a holding cradle 17 for the seeds, which is recessed along the thickness of the disc member, preferably by a thickness comprised between 5% and 90% of the thickness of the disc member. Alternatively, the cradle can protrude from the disc member by an axial protrusion. In both the protruding and recessed solutions, the cradle 17 is preferably arranged at least angularly corresponding to some of the holes 7 and extends circumferentially so that, when the disc is introduced into the seed pick-up chamber (for a collection bowl comprising loose seeds), the cradle 17 at least partially counteracts the weight of the loose seeds on the seeds held by the holes of the circle.

[0043] Preferably, for each hole 7 of the disc, a seed-holding cradle portion 17 is configured, which corresponds in angle to the respective hole 7 (example of Figure 6a ), or for each pair of holes, a cradle portion is configured (example of Figure 6f ), or even a continuous cradle portion in the form of an annular ring is configured (example of Figures 1 to 3 , Figures 6b to 6e ).

[0044] In the proposed embodiments, the cradle portion 17 is located at the base of a recess 18, which can extend circumferentially to at least partially form an annular cavity or a continuous annular cavity, as described in the preferred example of Figures 1 to 3 .

[0045] It is provided that, in some embodiments, the circumferential extension of the section of the partially formed annular cavity can be, for example, at least 1.5 times the diameter of the hole 14 and, in some examples, at least 3 times the diameter of the hole 14.

[0046] Experimental tests have shown that, for the same geometry of the holes 7, the presence of the annular cavity 14 significantly increases the probability of effective pick-up of the seeds, forming a firm hold on the seeds despite the collisions with other seeds in the pick-up chamber, thus allowing a greater rotational speed of the disc for the same separation accuracy. The presence of the annular cavity 14 and the stabilizing action on the seeds held by the disc further avoids the stall effect, which is generated on the disc when one or more seeds are detached from the respective hole 7 or are not associated with the respective hole 7, thus causing the air to pass freely through the disc and thus reducing the aerodynamic holding force on the seeds located in the remaining holes 7 on the disc. The effects of the reduced holding capacity propagate, the holding capacity gradually becoming worse as the seeds are detached from the disc, thus causing in particular the propagation of the stall effect and the failure of the sowing accuracy.

[0047] Preferably, the disc-shaped member is also provided with stirring means for the seeds, which in the proposed example can advantageously be formed by a plurality of recesses 15, which are arranged alternately with respect to the entire thickness of the disc, which extend from the annular cavity 14 in the radial direction towards the central portion of the disc. Preferably, between circumferentially adjacent radial recesses 15, a protrusion 19 is defined for the stirring of the seeds. In this way, the protrusions 19 do not negatively affect the gripping of the seeds in the area of the respective holes.

[0048] With reference to Figure 8In the example of the application, it can also be provided that the protrusions 19 for stirring the seeds can be formed inside the annular cavity 14. Preferably, the axial thickness of these protrusions 19 is less than the overall thickness of the disc. In this way, the presence of the protrusions 19 does not interrupt the continuity of the annular cavity 14, at least in the portion of the annular cavity which is axially between the top of the protrusions 19 and the regular surface of the disc.

[0049] In some embodiments, as shown in the example of the application, Figure 2 In some embodiments, as shown in the example of the application, the radial dimension LI of the annular cavity is not less than the radial dimension L2 (e.g. the internal diameter) of the hole, or alternatively, the radial dimension LI of the annular cavity is not less than 0.5 times the radial dimension L2 of the hole.

[0050] In some embodiments, the ratio between the radial dimension LI of the annular cavity and the radial dimension L2 of the hole is less than or equal to 5, and in some particular examples, the ratio between the radial dimension LI of the annular cavity and the radial dimension L2 of the hole can be less than or equal to 2.

[0051] In some embodiments, the annular cavity 14 has a depth t, in particular an axial depth, which is preferably comprised between 5% and 50% of the radial dimension of the annular cavity itself, and more particularly, the depth t is comprised between 10% and 25% with respect to the above-mentioned radial dimension.

[0052] Therefore, the application solves the problems set out, thus achieving a number of advantages, particularly when used on a pneumatic seeder of large size, in which the number of seeding units is large and therefore the problems related to the pneumatic seal between the seeds and the disc are multiplied. In particular, an improved adhesion of the seeds is obtained, thus increasing the seeding precision, it is possible to increase the seeding speed without drawbacks, it reduces the stalling effect of the seeds, it reduces the energy consumption of the entire seeder.

Claims

1. A seed-distributing disc (1) for a pneumatic seed drill, said seed-distributing disc (1) comprising a disc-shaped member (100) in which at least one ring of perforations (7) is formed, said disc-shaped member defining a seed side (4) and an air side (6) opposite each other, such that as a circumferential portion comprising at least one ring of said perforations (7) enters a bowl about loose seeds, said seed-distributing disc is introduced into a bowl about loose seeds, seeds are held by each of the at least one ring of perforations at the seed side (4) as a result of the action of a pneumatic pressure difference between said seed side (4) and said air side (6), characterized in that, The disc-shaped member comprises at least one seed-holding cradle portion (17) adjacent to at least one of the turns of through-holes on the seed side at the radially innermost side with respect to the respective turn of through-holes, the seed-holding cradle portion being provided at least angularly corresponding to some of the turns of through-holes and extending circumferentially so that, when the disc-shaped seeding element is introduced into the bowl-shaped element with loose seeds, the seed-holding cradle portion at least partially counteracts the weight of loose seeds on the seeds held by the turns of through-holes.

2. A disc (1) for sowing according to claim 1, characterised in that The disc-shaped seeding element (1) comprises a seed-holding cradle portion (17) for each through-hole or each pair of through-holes of the turns of through-holes (7), the seed-holding cradle portion (17) respectively corresponding angularly to the respective through-hole or the respective pair of through-holes.

3. A disc (1) for sowing according to claim 1 or 2, characterised in that The seed-holding cradle portion (17) is located at the base of a recess (18).

4. A disc (1) for sowing according to claim 3, characterised in that The recess extends circumferentially to at least partially form an annular cavity (14).

5. A disc (1) for sowing according to claim 4, characterised in that, The annular cavity (14) is continuous.

6. A disc for sowing according to claim 4 or 5, characterised in that The radial dimension of the annular cavity (14) is not less than the radial dimension of each of the turns of through-holes (7).

7. A disc for sowing according to claim 4 or 5, characterised in that The disc-shaped seeding element comprises a plurality of radial recesses (15) open in the annular cavity (14) at a radially innermost position with respect to the annular cavity, a protrusion (19) for agitating the seeds being defined between circumferentially adjacent radial recesses (15).

8. A disc for sowing according to claim 4 or 5, characterised in that The radial dimension of the annular cavity (14) and the radial dimension of each of the turns of through-holes (7) have the same order of magnitude.

9. A disc for sowing according to claim 4 or 5, characterised in that The ratio between the radial dimension of the annular cavity (14) and the radial dimension of each of the turns of through-holes (7) is between 0.5 and 5.

10. A seeding unit (2) for a pneumatic planter, characterized in that, The seeding unit (2) comprises a disc-shaped seeding element according to any one of claims 1 to 9.

11. The seeding unit of claim 10, wherein, The seeding unit comprises a housing (20) inside which the disc-shaped seeding element is arranged to determine and separate a first region (3) and a second region (5), a pneumatic pressure difference being established between the first region (3) and the second region (5), wherein the first region (3) faces the seed side (4) of the disc-shaped seeding element and delimits a bowl-shaped element with loose seeds, and wherein the second region (5) faces the air side (6) of the disc-shaped seeding element.

12. A pneumatic seeder (200) characterized by, The pneumatic seeder (200) comprises a carrier structure (21) and a plurality of seeding units according to claim 10 or 11 arranged on the carrier structure.

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