WO2019052587A1

WO2019052587A1 - Seed metering device

Info

Publication number: WO2019052587A1
Application number: PCT/CZ2018/000045
Authority: WO
Inventors: Miloslav Lenfeld; Petr May
Original assignee: Farmet A.S.
Priority date: 2017-09-16
Filing date: 2018-09-13
Publication date: 2019-03-21
Also published as: CZ307712B6; CZ2017548A3

Abstract

A seed metering device, specifically a seed metering device (1) for seed grain (4) arranged on a sowing machine, comprising a negative air pressure or positive air pressure carrier disc (2) for seed grain (4) and an outflow seeding tube (3) for seed grain (4) towards the sowing area, and which comprises two opposed firing wheels (6, 7) adjacent to the carrier disc (2), which are simultaneously arranged in front of the mouth (5) of the outflow seeding tube (3), wherein the firing wheels (6, 7) are arranged to be in mutual contact.

Description

Seed metering device

Technical field

The invention relates to a device for the metering of seeds, specifically to a device for the metering of seeds, mounted on a sowing machine, comprising a means of support and a tube for outlet of the seeds towards the seed drill area, which is part of a machine for precise sowing.

State of the art

Currently known machines for precision sowing contain a metering device which acts as a seed grain metering device. The metering device may be in the form of a drum, disc or similar rotating geometry with a perforated surface. Thanks to varying air pressures on either each side of the perforated surface, seed grains become attached to it. Seeds become attached to the perforations in the direction of the pressure gradient.

There are also currently known design solutions for solving the movement of seed grain from the metering device to the sowing area.

Among these design solutions can be included for example a pressurised disc metering system where, when after being released from the metering disc, the seeds usually fall by gravity into a short pipe called a seeding tube and then on into the soil. The disadvantage of this design is a significant decrease in accuracy at higher frequencies of seeding and a reduction in accuracy due to vibrations of the seed drill when moving through the soil. A gravitational system is unusable for precise sowing of cereal grains at higher frequencies.

From patent application WO 2010059101 A1 there is also known a metering system with a single disc on which, on one side of the disc, positive pressure is created which causes the air to flow through the openings on the disk. The resulting pressure gradient is used to adhere the seeds, which are subsequently transported by the metering disk to the location where a device for interrupting the air flow through the openings is located. Here the seeds are released from the metering disc and fall into an outflow seeding tube for release which is located here. A portion of the pressurised air escapes through the outflow seeding tube and creates a flow of air that transports the seeds through the tube and into the soil. This solution partially removes the disadvantage of the gravitational system described above, and is particularly suited for sowing maize. It does not suit cereal grain sowing because of the low initial kinetic energy and the low initial velocity of the seeds leading to significant inaccuracy in the spacing of the seeds after their passing through the outflow seeding tube.

From another patent application DE 102007062967 A1 a metering system is known with a metering disc where the seeds are blown through a nozzle into an outflow seeding tube in a radial direction perpendicular to the tangent of the metering disc. The disadvantage of this design is a significant change in the direction of movements of the seed after being released from the metering disc when the seed changes the direction of its movement by about 90°. This change in direction of seed movement increases the inaccuracy at higher circumferential disk speeds of seed movement within the tube and thus leads to great inaccuracies in the final spacing of seed placement in the soil. A major disadvantage is also that, at a certain rotational speed of the metering disk, kinetic energy does not cause the seed to be redirected to the outflow seeding tube, but the seed returns to the hopper, thereby omitting one sowing site, which is a major failure of the sowing machine.

From the patent document CZ 305159, a seed grain metering device is known arranged on a sowing machine, comprising a means of support and an outflow seeding tube to the seed drill area, where the means of support is specifically negatively or positively pressurised which comprises at least one tube with pressurised air directing seed from the means of support into the outflow seeding tube, while the pressurised air tube adjoins the means of support support and its axis with the tangent support holds at an angle β = ± 30°, and the outflow seeding tube abuts against the means of support, while its axis with the tangent means of support is held at an angle a = ± 30°. Although this design provides very precise sowing, it has the great disadvantage of increased sensitivity to particle contamination that can develop under difficult operating conditions.

A precision sowing device is further known from EP2747541. The device comprises of a carrier disc with openings in which individual seed grains are carried by means of negative air pressure and are transferred to a seed conveyor by means of a pair of loading wheels, which transports individual grains into the sowing area with high precision. The loading wheels are spaced apart from each-other with a gap between, thus passing the grains into the seed conveyor at a low speed for a short distance. Were the velocity higher, it would lead to the grains being returned by deflection resulting in inaccurate sowing. A major drawback of this device is its relatively complex design with a great number of individual parts. Related to this, considering the difficult conditions in which the equipment operates, there is a high probability of malfunctions and heavy wear, and with this associated high service costs.

It is evident from the above-mentioned current technology that the main disadvantage of the current technology is that these known sowing machines do not guarantee precise sowing at high speeds, this disadvantage being greatly increased under difficult operating conditions.

The object of the invention is the design of a device for metering seed grains, which is able to ensure precise sowing at high speeds under difficult working conditions.

Principle of the invention

The mentioned deficiencies are to a large part removed and the objectives of the invention fulfilled by an individual seed metering device, specifically by an individual seed metering device arranged on a sowing machine, comprising a positive or negative air pressure carrier disc and an outflow seeding tube towards the sowing area, according to the invention, the principle of which is that it comprises two mutually arranged firing wheels adjacent to the carrier disc, the firing wheels being mounted in front of the outflow seeding tube while the firing wheels are arranged so that they are in mutual contact with each-other. The advantage is a firm and accurate attaching of the seed grains, which allows for their high output velocity, resulting in very precise timing of individual seed grains and so to corresponding high sowing precision, with the added reliability of this device even under difficult operating conditions.

It is to advantage if the firing wheels are arranged for high-speed transfer of seed carried by the carrier disc directly through the mouth of the outflow seeding tube to the sowing area. The advantage is that the seed grain, which is regularly and very precisely accurate, is without any further contact with the metering device, delivered directly into the outflow seeding tube, for example without touching the housing, and can thus essentially fly directly to the sowing area.

Furthermore, it is to advantage that the firing wheels are arranged perpendicularly to the surface of the carrier disc. The advantage of this is that this arrangement allows for the most accurate handling of the seed grains.

It is to great advantage to have the firing wheel surfaces adapted to receive the seed. For example, the surfaces may be shaped to receive a certain seed grain size or, they are preferably made from an elastic material, the most preferred embodiment being the surface of at least one of the firing wheels being made of rubber. The advantage is the very precise and stable gripping of seed grains.

It is also to advantage for the firing wheels to have a mutual contact space arranged above the ring of openings made in the carrier disc. The advantage is optimal alignment of the seed trajectories with the firing wheels, thus ensuring that the seed grains are seamlessly delivered and thus uninterrupted by the exact timing of the sowing of individual seeds. It is to greatest advantage if the contact space is arranged perpendicular to the surface of the carrier disc.

Closely related to the above and to further advantage is if the axis of the outflow seeding tube is identical to the tangent of the ring of openings made on the carrier disc. The advantage is the undisturbed trajectory of the seed grain movement from their delivery by the carrier disc to the sowing area.

Crucial to precise sowing is accurate timing of the motion of the two firing wheels. This is achieved to greatest advantage by the the firing wheels being connected to each other by cog gears which are arranged on their sides.

To advantage, at least one of the firing wheels is connected to a power drive. In a possible variant, one of the firing wheels may be connected by a cog gear to the carrier disc or to its power drive.

The main advantage of the seed metering device according to the invention is that, in addition to high precision sowing at high speeds, there is mainly a major increase in operational reliability, compared to currently known technology. The device allows the achievement of a high uniformity in the transit of individual seeds and their correct positioning upon exit from the outflow seeding tube under the pressing wheel of the seed drill at the required target pitch into the sowing area, and this especially at a higher frequency of seed movement by the sowing device associated with higher seed velocity at higher speeds of the machine moving through the field. Another advantage is the relatively small number of parts that make up the device, which means not only lower production costs, but also lower service costs and overall greater resistance to wear.

Overview of the figures

The invention will be further elucidated using drawings, in which Fig. 1 shows a frontal view in cross section of the detail of the arrangement of the firing wheels and the carrier disc; Fig. 2 shows a spatial cross-sectional view of the firing wheels on which are arranged cog gears and power drives; and Fig. 3 shows a spatial view of the arrangement of the seed metering device on the sowing machine.

Examples of the performance of the invention

The seed metering device 1 for seed grains 4 (Fig. 1 , Fig. 2, Fig. 3) is arranged on a sowing machine. The seed metering device 1 for metering seed grains 4 comprises a negative air pressure carrier disc 2 for seed grains 4 and a outflow seeding tube 3 for outflow of the seed grains 4 towards the sowing area.

The seed metering device 1 for metering seed grains 4 comprises two counter-arranged firing wheels 6,7 adjacent to the carrier disc 2 which are simultaneously arranged in front of the mouth 5 of the outflow seeding tube 3.

The firing wheels 6,7 are arranged in mutual contact for the high-speed transfer of seed grains 4 delivered by the carrier disc 2 through the mouth 5 of the outflow seeding tube 3 for the seed grains 4 to the sowing area.

The firing wheels 6,7 are arranged perpendicularly to the surface of the carrier disc 2.

The firing wheels 6,7 have a surface adapted to receive the seed grains 4 so that the surfaces of the two firing wheels 6,7 are made of rubber. This makes it possible to create a mutual contact space 9 of both of the two firing wheels 6,7. This contact space 9 is arranged above the ring 10 of openings 8 made in in the carrier disc 2 and is at the same time perpendicular to the surface of the carrier disc 2.

The axis of the outflow seeding tube 3 for seed grains 4 is identical with the tangent H to the ring 10 of openings 8 made in the carrier disc 2. The firing wheels 6,7 are connected to each other by cog gears 12,13 which are arranged on their sides, so that one of the firing wheels 6 is connected to the power drive 14.

The seed metering device 1 for metering seed grains operates in such a way that on one side of the carrier disc_2 negative air pressure is created at the place of the openings 8, while through the openings 8 in the carrier disc 2, air flows and a suction effect is created thus sucking onto the other side of the carrier disc 2 the seed grains 4, at which is arranged in a picking up space (not shown). After the seed grains 4 are sucked onto the carrier disc 2, the seed grains 4 pass by rotation of the carrier disc 2 with a so-called comb (not shown), which combs away the extra seed grains 4 so that each opening 8 sucks up a single seed grain 4. On the side of the carrier disc 2 opposite to the picking up space a positive air pressure disconnector (not shown) is located. At the moment the negative pressure is cut off, the seed grain 4 is released while at the same time it is gripped by firing wheels 6,7 which shoot the seed grain 4 into the mouth 5 of the outflow seeding tube 3 which feeds it into the sowing groove below the pressing wheel 15.

Industrial Application

A seed metering device for seed grain metering, which according to the invention can be used on agricultural machines for the precise sowing of seed grains.

10

List of Reference Marks

1 seed metering device

2 carrier disc

3 outflow seeding tube

4 seed grain

5 mouth

6 firing wheel I

7 firing wheel II

8 opening

9 contact space

10 ring

11 tangent

12 cog gear I

13 cog gear II

14 power drive

15 pressing wheel

Claims

7 Patent claims

1. A seed metering device, in particular a seed metering device (1) for seed grain (4) metering arranged on a sowing machine, comprising a negative air pressure or positive air pressure carrier disc (2) and an outflow seeding tube (3) towards the sowing area, characterised by that it comprises two mutually arranged firing wheels (6,7) adjacent to the carrier disc (2), which are arranged simultaneously in front of the mouth (5) of the outflow seeding tube (3) for the seed grains (4), wherein the firing wheels (6,7) are arranged to be in mutual contact.

2. The seed metering device according to claim 1 , characterised by that the firing wheels (6,7) are arranged for high-speed transmission of the seed grains (4) brought by the carrier disc (2) over the mouth (5) of the outflow seeding tube (3) for the seed grains (4) to go into the sowing area.

3. The seed metering device according to any one of the preceding claims, characterised by that the firing wheels (6,7) are arranged perpendicular to the surface of the earner disc (2).

4. The seed metering device according to any one of the preceding claims, characterised by that the firing wheels (6,7) have a surface adapted to receive seed grains (4).

5. The seed metering device according to claim 4, characterised by that at least one of the firing wheels (6,7) have a surface made of rubber.

6. The seed metering device according to any one of the preceding claims, characterised by that the firing wheels (6,7) have a mutual contact space (9) arranged above the ring (10) of openings (8) made in the carrier disc (2).

7. The seed metering device according to any one of the preceding claims, characterised by that the axis of the outflow seeding tube (3) for seed grains (4) is identical with the tangent (11) to the ring (10) of openings (8) made in the carrier disc (2).

8. The seed metering device according to any one of the preceding claims, characterised by that the firing wheels (6,7) are connected to each other by cog gears (12,13) which are arranged on their sides. 8

9. The seed metering device according to any one of the preceding claims, characterised by that at least one of the firing wheels (6) is connected to a power drive (14).

10. The seed metering device according to any one of the preceding claims 6 to 9, characterised by that the contact space (9) is perpendicular to the surface of the carrier disc (2).