Dosing device for particle distribution system for agricultural machinery, corresponding dosing method and agricultural machinery.

Abstract

Dosing device for particle distribution system for agricultural machine, corresponding dosing method and agricultural machine. The invention relates to a dosing device (20) for particle distribution system for agricultural machine (200) which can move on a terrain, comprising a tank (21) having in a lower part a conveyor (22) capable of transporting said particles towards an outlet orifice (23) of said tank, comprising at least one movable hatch, called downstream hatch (24), which can take a plurality of positions between a closed position and an open position. According to the invention, the dosing device comprises means for obtaining slope information representative of a slope of a terrain on which said agricultural machine is moving, and means for controlling the position of said downstream hatch(es) taking into account said slope information. Figure for abstract: figure 2

Description

Title of the invention: Dosing device for particle distribution system for agricultural machine, corresponding dosing method and agricultural machine. [0001 ] 1. Field of the invention#

[0002] The field of the invention is that of the distribution of particles for agriculture, and in particular fertilizers, in the form of granules, bulk products, pellets or powder. More specifically, the invention relates to the dosing of these particles, during their distribution by an agricultural machine. 1. Prior art and its drawbacks#

[0003] There are currently two main particle distribution systems for agricultural machinery, namely mounted spreaders which are fixed to the tractor chassis and carried by the latter, and trailed, or towed, spreaders which comprise a chassis and a set of wheels, and which are towed by the tractor. Such trailed or mounted spreaders also comprise a tank, as well as a spreading module for distributing the particles to be spread. Trailed spreaders generally have tanks, or hoppers, of larger capacity than mounted spreaders.

[0004] The present invention applies equally well to particle distribution systems of the mounted spreader type as well as to trailed or towed spreader types.

[0005] In such spreaders, the spreading module generally receives the particles via a conveyor, formed by a conveyor belt, or mat, circulating around return cylinders, or drive rollers, in the lower part of the feed tank. Most often, the conveyor extends, in the direction of advance of the agricultural machine, from the front part to the rear part of the tank, and makes it possible to convey the particles from the tank to an outlet orifice arranged on the rear face of the latter. The particles then fall from the conveyor towards the spreading module located downstream of the tank.

[0006] There are also different types of spreading modules that can be attached to the rear of such spreaders, depending on the nature of the product to be spread. These spreading modules are attached, in a removably manner, below the outlet orifice of the tank.

[0007] For both economic and environmental reasons, there is an increasing demand for precision agriculture, allowing fine control of the quantity of particles to be spread on a plot. This requirement for precision mainly concerns granular fertilizer products, distributed by means of precision centrifugal rotating discs.

[0008] Several systems for dosing the quantity of particles to be spread have been proposed to date.

[0009] A first approach consists of modulating the dose of particles to be spread, by acting on the speed of movement of the conveyor belt. The outlet orifice of the feed tank is then of constant section. Increasing the speed of movement of the conveyor leads to an increase in the dose of particles spread. Such an approach imposes strong constraints on the conveyor drive system, which therefore proves to be complex and expensive, in particular to adjust the speed ratio necessary to modulate the dose to be distributed.

[0010] A second approach consists of modulating the dose of particles to be spread by acting on the section of the outlet orifice of the tank. The conveyor then moves at a speed proportional to the forward speed of the agricultural machine, and the dose is adjusted by opening the outlet orifice more or less, by means of a movable hatch.

[0011] In this type of dosage modulation system, the hatch(es) closing the outlet orifice of the tank are most often vertical, or possibly follow the generally truncated shape of the hopper or tank, the hatch(es) then returning towards the inside of the tank.

[0012] When the trapdoor (or trapdoors) is in the closed position, its lower end is generally located at a fairly large distance upstream of the point from which the particles fall from the conveyor belt towards the spreading module, typically of the order of 400 mm. Considering a travel speed of the agricultural machine of approximately 10 km / h, it follows that the agricultural machine may have traveled up to approximately 15 m in the field, between the moment when the movable trapdoor is completely closed to stop the supply of particles to the spreading module, and the moment when the spreading module actually stops distributing all the particles which were already present on the conveyor downstream of the outlet orifice at the time of closing. The reaction time and distance are therefore much too long, with this type of system, to allow good dosing of the fertilizer in all circumstances.

[0013] Patent document EP 3 138 375 of the Applicant describes a dosing technique allowing controlled feeding of the spreading module without reaction time, or with a minimal reaction time, via the use of at least one movable trapdoor inclined relative to the plane of the conveyor, the position of the inclined trapdoor making it possible to be as close as possible to the fall of the product at the outlet of the conveyor towards the spreading device.

[0014] However, the agricultural land on which the particles are spread is not always flat and the spreader can therefore move on slopes, which can lead to to critical situations for the good control of the flow of particles, calling into question the techniques based on movement on flat ground. Indeed, when the agricultural machine is inclined relative to a horizontal position, the angle of slope, or angle of slope, of the particles relative to a reference linked to the spreader, decreases or increases, depending on the angle of the slope. As illustrated in [Fig.l], for a distribution system 10 of a spreader (not illustrated) comprising a hopper 11 (or tank) and a vertical movable hatch 13, this can go for example until the slope of the particles goes beyond the point of fall of the particles from the conveyor system 12 towards the spreading system, and therefore generate a continuous flow 14 of the particles.

[0015] It is recalled that the angle of repose / slope is a slope angle characteristic of certain materials. When a granular or powdery material is deposited by gravity on a surface, it tends to form, when enough grains are deposited, a conical-shaped pile. The angle of slope of the cone relative to the surface, also called the angle of repose or slope, is, to a large extent, a characteristic of the nature of the particles, but also of their geometry, their dimensions and the homogeneity of their sizes throughout the pile. Such an angle of repose is, for particles to be spread by an agricultural spreading system, generally between 30° and 40°.

[0016] The techniques described above therefore do not allow the flow of particles from the tank to be controlled, and therefore do not allow the desired dose of particles to be spread to be respected, whatever the slope of the terrain on which the agricultural machine is moving. In certain steep slope situations, product leaks can even render the machines unusable.

[0017] There is therefore a need for a particle dosing technique for distribution systems for agricultural machinery which does not have these various drawbacks of the prior art.

[0018] In particular, there is a need for such a technique which makes it possible to carry out precision spreading with precise control of the dose to be spread regardless of the configuration of the terrain on which the agricultural machine is moving, and in particular in the case of slope and / or sloping terrain. More specifically, there is a need for such a technique which makes it possible to meet the requirements of precision agriculture, by offering increased responsiveness in modifying the dose to be spread compared to previous systems during the movement of the agricultural machine over the terrain to be spread.

[0019] There is also a need for such a technique that is simple and inexpensive. 1. Statement of the invention#

[0020] The invention meets this need by proposing a dosing device for a particle distribution system for an agricultural machine capable of moving on land, comprising a tank having in a lower part a conveyor capable of transporting the particles towards an outlet orifice of the tank, comprising at least one movable hatch, called downstream hatch, capable of taking a plurality of positions between a closed position and an open position. The dosing device comprises means for obtaining slope information representative of a slope of a terrain on which the agricultural machine is moving, and means for controlling the position of the downstream hatch(es) taking into account the slope information.

[0021] Thus, the invention is based on a completely new and inventive approach to particle dosing for agricultural spreading systems that makes it possible to take into account the configuration of the terrain over which the spreader is moving. To do this, the dosing device detects the slope of the terrain, during the movement of the spreader, so that the control means with which it is equipped increase or decrease the opening of the downstream hatch(es) according to the detected slope. The position of the downstream hatch(es) therefore takes into account the configuration of the terrain over which the spreader is moving, thus regulating the volume of particles that flow in order to respect the desired dose of particles in real time and with precision.The invention makes it possible to effectively and precisely compensate for the effects on the spread dose of particles caused by the configuration of the terrain on which the agricultural machine is moving, without requiring an additional system of traps or flaps to prevent uncontrolled flow of fertilizer in the event of a steep slope, for example. This solution also does not require any action by the operator, the control means constituting an automatic control of the position of the downstream trap(s) according to the detected slope. Furthermore, this technique makes it possible to retain the advantages of volumetric dosing, i.e. without an agitator, while allowing the use of the agricultural machine equipped with it on sloping ground.

[0022] The means for obtaining the slope information comprise, for example, one or more inclination sensors, or inclinometers, carried by the spreader as well as means for transmitting this slope information to an integrated computer and potentially already present, for other functions, on the spreader. Such inclination sensors measure the angle of the machine relative to a reference frame; it is therefore necessary, to measure a slope, to tare (set to 0) the sensor attached to a spreader under the spreading conditions (tires, hitch height, type of tractor, etc.).

[0023] Furthermore, the control means comprise on the one hand dedicated actuators, for example actuating cylinders, for modifying the position of the downstream hatch(es), and on the other hand data processing means. Such data processing means receive data such as the steep slope information in from a tilt sensor (directly or via a computer integrated into the spreader for example) and transmit commands to control the actuators to modify the position of the downstream hatch(es). These different means can be grouped together.

[0024] For example, the control means reduce the opening of said at least one downstream hatch when the slope information corresponds to a positive slope in the direction of movement of the agricultural machine, so as not to be placed in a situation of continuous flow of particles.

[0025] According to one embodiment of the invention, the control means deliver information on the opening limit of said at least one downstream hatch taking into account the steep slope information and information aT on the angle of slope characteristic of the particles. This opening limit information corresponds more particularly to a point beyond which the desired dose of particles would not be respected because of the slope of the terrain, and / or a potential risk of untimely flow of the product, even when stopped, is increased. Indeed, in the case of a positive slope for example, if the downstream hatch(es) are open beyond this point, the supply of particles is too great and the dosage is therefore distorted.In order to provide optimal opening limit information, the control means therefore take into account not only the detected slope but also the characteristics of the particles to be spread, and more particularly their angle of slope. In this way, in a situation of positive slope in the direction of movement of the spreader, the control means are able to reduce the opening of the movable hatch so that it comes at least into contact with the slope formed by the particles at the slope. This solution also guarantees the versatility of the machine by taking into account certain specificities of the product to be spread and therefore being adaptable according to the type of particles.

[0026] According to a particular aspect, said at least one downstream hatch is inclined relative to the plane of the conveyor, so that, in the fully closed position, a lower end of the downstream hatch is located substantially vertically above an axis of rotation of a drive roller or drum of the conveyor, close to the outlet end of the conveyor. Thus, in the closed position, the downstream hatch(es) is / are located directly above the point where the particles leave the belt. This allows controlled feeding of the spreading module without reaction time, or with minimal reaction time because the position of the hatch makes it possible to be as close as possible to the fall of the product at the outlet of the conveyor towards the spreading device. The value of the flow rate set upstream is therefore controlled instantly at the level of the fall of the product to be spread (no delay between the adjustment by the hatches and the fall). The instantaneous accuracy of the dosage is thus improved.Furthermore, the actuation of the downstream hatch(es). is facilitated by their inclination, due to the fact that the traps do not "enter" into the particles when they are lowered to close the outlet orifice.

[0027] Furthermore, in this case, the opening limit information also takes into account the inclination of the downstream hatch(es), via information on the inclination angle of said at least one downstream hatch. Thus, according to this embodiment, the metering device of the invention benefits from the aforementioned advantages of an inclined downstream hatch and the means for controlling the position of the inclined downstream hatch take into account the angle of inclination of the hatch to calculate the opening limit information more precisely, thus optimizing the precision of the particle metering.

[0028] According to one embodiment of the invention, the opening limit information takes into account a point E whose coordinates (XE; YE) are calculated as follows, in a reference frame R defined by an abscissa axis extending in the plane of the conveyor and parallel to the direction of movement of the conveyor and an ordinate axis extending perpendicular to the plane of the conveyor and passing through the rear wall of the tank:

[0029] (XE; Ye) = ([Yd - YcHTana^pe- Tana]; YD - XE *Tanatrappe) with: • (XA; Ya) corresponding to the coordinates of axis A, in the R reference frame, of the conveyor drive drum, a parameter known for the dosing device considered • aconveyorcorresponding to the angle of inclination of the conveyor belt, a parameter known for the dosing device considered • Ct Cty 4“ sloping conveyor • (XB ; Yb) = (XA + Sina * [AB] ; YA + Cosa * [AB]) with [AB] corresponding to the radius of the conveyor drive drum, with center A, a parameter known for the dosing device considered (Xc; Yc) = (0 ; YB+XB * Tana) • (XD; Yd) corresponding to the point of intersection between the rear surface of the tank and the sliding surface of said at least one downstream hatch, a parameter known for the dosing device considered.

[0030] Thus, the control means determine the coordinates of a point from data obtained in real time during the movement of the spreader (such as information representative of the slope of the ground) and from known data associated with the spreader itself (such as the radius of the conveyor drive drum, the angle of inclination of the conveyor belt or the angle of inclination of the downstream trap(s), these coordinates then making it possible to determine information on the opening limit of the downstream trap(s). It is therefore observed that the aforementioned equation makes it possible to obtain a curve defining the opening limit of a downstream trap as a function of the slope of the ground on which the spreader is moving. From this curve, the dosing device can control the opening of the hatch with each new slope information obtained, following the above-mentioned formula.

[0031] According to another operation, called by step, the metering device can control the opening of the hatch by taking into account slope values ​​included in slope angle intervals. Thus, the opening limit information has a coordinate value Y'E, called step value, identical for each value of the steep slope information included in a given interval, the step value Y'E being less than or equal to the coordinate value YE.

[0032] Thanks to this step-by-step control of the opening of the downstream hatch, the calculations are simplified, for example by providing additional closing steps of the hatch of 20% every additional 5° increase in the slope. This step-by-step operation also makes it possible to limit the number of mechanical movements for opening or closing the downstream hatch, thus ensuring a better lifespan of the actuators and the hatch itself. Advantageously, this step-by-step operation makes it possible to obtain better precision of the particle outlet flow rate by limiting the transient phases (between two positions of the downstream hatch(es). Finally, this avoids the risks of hysteresis and instability due to too frequent changes in the position of the downstream hatch(es).

[0033] According to a particular aspect, the slope information is also representative of a slope of the terrain on which the agricultural machine is moving, thus making it possible to take into account not only the slope in the direction of movement of the machine but also the slope of the terrain. Indeed, the slope, if it is significant, leads to a more or less significant accumulation of particles on one of the lateral sides of the conveyor belt. The present technique makes it possible to take this into account also via means for obtaining the slope angle and by adjusting the slope information to take into account the slope angle obtained / detected.

[0034] According to a particular characteristic, the dosing device comprises means for regulating the speed of the conveyor taking into account the position of said at least one downstream hatch and / or the steep slope information. In this way, it is possible to modulate the speed of the belt to refine / adjust the effects of controlling the position of the downstream hatch. For example, in the case of a steep slope, the means for controlling the position of the downstream hatch may require significant closure of the downstream hatch to prevent a continuous flow of particles, potentially leading to a reduction in the spread dose below the desired dose. Regulating the speed of the conveyor belt, in this case increasing the speed, makes it possible to compensate for this reduction in the dose, in order to restore the desired dose, while preventing a continuous flow.

[0035] For example, the means for regulating the speed of the conveyor take into account the opening limit information E and therefore the position of the downstream movable hatch.

[0036] Such a combination of means, acting both on the opening of the downstream movable hatch(es) and on the speed of the conveyor, taking into account both the slope detected as the spreader moves and the angle of slope of the particles to be spread, makes it possible to obtain optimal spreading performance in terms of precision and responsiveness, whatever the configuration of the terrain.

[0037] According to another particular aspect, the metering device comprises means for adjusting an angle of inclination of the downstream trap(s), in particular to take into account characteristics of the particles to be spread, such as the angle of slope, and thus optimize the precision of the desired metering of particles to be spread. It is possible to provide an angle of inclination of the downstream trap(s) close to or corresponding to the average angle of slope of the particles to be spread by the distribution system. Since the angle of inclination of the trap substantially follows the angle of slope of the particles, the reactivity between a modification of the position of the opening of the trap(s) and the fall of the particles towards the spreading module is increased. Thus, according to the metering device of the invention, very good precision and high reactivity are obtained.In addition, the raising / lowering movements of the hatches are effortless, thanks to the slope angle which reduces friction between the hatches and particles. It is thus possible to provide means of actuating the hatches in the form of small, low-power cylinders, which are more responsive, which is also economically advantageous.

[0038] According to a particular characteristic of the invention, the dosing device comprises a particle supply tunnel, having an inlet opening and an outlet opening, the outlet opening being controlled by the downstream trap(s) and the inlet opening being controlled by a second trap, called the upstream trap. This tunnel makes it possible to regulate the arrival of the particles at the downstream trap(s) and thus to avoid compression and blockage phenomena while reducing the forces and pressures on the trap(s). This tunnel also has the advantage of reducing particle leaks and facilitating the sizing of the trap actuators. This tunnel is particularly advantageous for the precise dosing of the processed products and the spreading of granules by sectioning the spreading width.

[0039] In the context of the invention, the metering device comprises means for controlling the opening of the upstream hatch, also taking into account the information representative of the steep slope. In this way, the detected slope is taken into account as soon as the particles leave the tank, at the position of the upstream hatch, as well as at the level of the downstream hatch(es), thus increasing the metering performance while limiting the risks of blocking the particles by compression before their exit towards the spreading device.

[0040] For example, the means for controlling the opening of the upstream hatch act in such a way as to provide a step in relation to the upper part of the tunnel, in order to further limit the risk of compression of the particles at the downstream hatches. Thus, this step at the entrance to the tunnel has the effect of shearing the small mass of product which is blocked by the edge of the upstream hatch and at the same time driven, towards the tunnel, by the flow of product below (driven by the conveyor belt). These two opposing actions cause the mass of particles to rotate, which is then free to rotate and advance without constraints in the tunnel. This solution is very simple and inexpensive and does not require any use of a retractable flap system, which has the disadvantage of no longer being operable when the machine is full. In addition, this solution makes the machine very easy to use for an inexperienced driver.

[0041] It should be noted that when two downstream mobile hatches are implemented, a first variant embodiment provides a tunnel with an upstream hatch and a second variant embodiment provides two tunnels each having an upstream hatch.

[0042] According to a particular aspect, the dosing device also comprises means for detecting a compression, or pressure greater than a predetermined threshold, in the tunnel, thus making it possible to detect very early on a probable future blockage. Indeed, when there is a significant slope, the product can begin to overfeed the tunnel and therefore to increase in pressure.

[0043] For example, the metering device comprises means for generating an alarm, called a jam alarm, if a compression is detected by the detection means for a predetermined period of time. Thus, the operator of the machine is informed of a potential upcoming jam and can implement preventive and / or corrective actions.

[0044] According to a variant, if a compression is detected, the means for regulating the speed of the conveyor are activated in order to reduce the quantity of particles at the entrance to the tunnel and to avoid a blockage, while informing the driver of the machine so that he knows that the desired dose of particles to be spread may not be correct at times.

[0045] According to another variant, the means for regulating the speed of the conveyor stop the belt and the user is offered to go into a specific mode for clearing.

[0046] For example, the means for detecting a compression comprise at least one of the elements belonging to the group comprising:

[0047] - at least one pressure sensor mounted in the tunnel;

[0048] - at least one movement sensor of a movable shutter mounted on the part upper tunnel;

[0049] - at least one camera placed at the exit of the tunnel;

[0050] - at least one weighing sensor mounted in the tunnel;

[0051] - at least one power measurement sensor of at least one controlling actuator one of the downstream hatches,

[0052] - at least one force sensor on one of the downstream hatches.

[0053] The invention also relates to a dosing method for a particle distribution system for an agricultural machine capable of moving on land, comprising a tank having in a lower part a conveyor capable of transporting the particles towards an outlet orifice of the tank, comprising at least one movable hatch capable of taking a plurality of positions between a closed position and an open position, and comprising:

[0054] - a step of obtaining information representing a slope of a terrain on which the agricultural machine moves

[0055] - a step of controlling the position of the hatch as a function of said information from slope cZperHe.

[0056] Such a method may of course have the various characteristics relating to the dosing device according to the invention, which may be combined or considered in isolation. Thus, the characteristics and advantages of this method are the same as those of the dosing device and are not detailed further.

[0057] The invention also relates to an agricultural particle distribution machine, comprising a tank having in a lower part a conveyor capable of transporting the particles towards an outlet orifice of the tank and a particle distribution system implementing a metering device as described previously and comprising at least one movable hatch, called a downstream hatch, capable of taking a plurality of positions between a closed position and an open position, the metering device comprising means for obtaining slope information representative of a slope of a terrain on which the agricultural machine is moving, and means for controlling the position of the downstream hatch(es) taking into account the slope information. 4. List of figures

[0058] Other aims, characteristics and advantages of the invention will appear more clearly on reading the following description, given as a simple illustrative, and non-limiting, example, in relation to the figures, among which: - [Fig.l] illustrates an example of a dosing device according to the prior art; - [Fig.2] illustrates a schematic diagram of a particle distribution system; - [Fig.3a] illustrates an example of controlling a vertical downstream hatch, depending on the slope of the terrain; - [Fig.3b] illustrates an example of controlling a downstream, inclined hatch, depending on the slope of the terrain; - [Fig.4] illustrates an example of calculating the position of the downstream hatch as a function of the slope; - [Fig.5] represents a curve resulting from the calculation of the position of the downstream trap as a function of the slope, for a particle slope angle of 27°; - [Fig.6] illustrates a step-wise operating curve for different particle slope angles; - [Fig.7a] illustrates an optimal situation for adjusting the downstream hatch, on flat ground; - [Fig.7b] illustrates an optimal situation for adjusting the downstream hatch, on slightly sloping ground; - [Fig.7c] illustrates a situation before implementation of the invention, on significantly sloping ground; - [Fig.7d] illustrates the situation of [Fig.7c], after implementation of the invention; - [Fig.8] illustrates a tunnel for supplying particles into the dosing device, according to one embodiment of the invention; - [Fig.9] illustrates a dosing method according to one embodiment of the invention.

[0059] 5. Detailed description of embodiments of the invention

[0060] The general principle of the invention is based, in a dosing device for a particle distribution system of an agricultural machine, on taking into account the slope of the terrain on which the agricultural machine is moving, in order to respect the desired dose of particles to be spread while the slope disrupts the arrival of the particles in the dosing device. It is thus possible to achieve precision spreading, from a conventional spreader that is equipped with such a dosing device, whatever the configuration of the terrain.

[0061] One could consider addressing this problem encountered on terrain with slopes, by increasing the distance between the mobile trap and the particle drop point on the conveyor system by lengthening the latter. Such a solution would, however, have the consequence of increasing the length of the conveyor and therefore its overall size. Its cost as well as the energy consumption to drive it would also be increased, while the machine's responsiveness would be reduced, for "section control" aspects for example.

[0062] The inventors have therefore developed a different and more efficient solution, which consists of providing the dosing device with means for obtaining information representative of the slope, which is used by means for controlling the position of one or more downstream hatches located at the level of an outlet orifice of the tank of the particle distribution system. Thus, the effect of the slope of the terrain on the behavior of the particles in the distribution system is compensated by an adjustment of the size of the opening of the downstream hatch(es), to maintain, in real time and whatever the configuration of the terrain, the desired dose to be spread.

[0063] This general principle is described in more detail below, in relation to Figures 2 to 8 and different embodiments and variants.

[0064] First of all, in relation to [Fig. 2], a schematic diagram of a particle distribution system for an agricultural machine 200 is presented, comprising a dosing device 20 supplied with particles of product to be spread via a conveyor 22 located below a tank, or hopper 21. Such a particle distribution system can be towed or carried by the agricultural machine. In addition, it can be a distributor of bulk product, granules, powder, plugs, or wet bulk.

[0065] The bottom of the tank 21 has a longitudinal opening under which the conveyor 22 is arranged. The latter comprises a conveyor belt 220, or belt, which is set in motion by a rear return cylinder 221, also called a drive roller or drum, movable in rotation around an axis A, as well as drive rollers (not illustrated) arranged along the belt 220. The conveyor 22 has a rear part corresponding to the part of the conveyor located under the dosing device 20, as well as a front part corresponding to the part of the conveyor located under the tank 21.

[0066] When the agricultural machine moves forward, in the direction of movement indicated by the arrow D, the product is transported outside the tank 21 by the belt 220 towards an outlet orifice 23 (shown by dotted lines).

[0067] The metering device 20 illustrated, according to one embodiment of the invention, comprises at least one movable hatch 24, called the downstream hatch. Thus, the choice of adjustment of the output flow rate of the particles from the distribution system is made by adjusting the output section of the reservoir 21, by adjusting the opening level of the downstream hatch 24.

[0068] In this embodiment, the dosing device comprises a downstream hatch 24, but an alternative embodiment provides for the presence of two downstream hatches, the respective positions of which are controlled independently by the control means of the invention, in particular to allow spreading over half a width. or to manage the width of the spreading layer, for example in field tips.

[0069] Furthermore, according to this embodiment illustrated in [Fig.2], the downstream hatch 24 is inclined. However, it can be vertical, according to another variant embodiment. Here, the angle of inclination of the downstream hatch 24 relative to the plane of the belt 220 of the conveyor 22 is an acute angle, so as to form a funnel in the direction of flow of the product. In this way, the weight of the particles does not rest excessively on the downstream hatch(es) 24 and therefore does not generate significant friction forces when they are opened or closed.

[0070] According to an embodiment, not illustrated, the angle of inclination of the downstream trap(s) can be adjusted by adjustment means of the metering device, for example to coincide substantially with the angle of slope of the product to be spread, which is generally between 30° and 40°, most often close to 35°. This makes it possible in particular to avoid a flow by gravity of the particles through the opening of the downstream trap(s), when the belt 220 is stationary. Indeed, when the belt 220 is stationary, and the downstream trap(s) are completely open (highest position), the particles remain stationary, because the angle of the pile that they form is equal to their angle of slope.

[0071] Thus, instead of providing a single metering device 20 to be fixed to the rear of the particle distribution system, in which the angle of inclination of the downstream trap 24 is equal to the average angle of slope of the particles to be spread by such a distribution system, or of providing several metering devices 20, having different trap inclinations which are chosen according to the particles to be spread and their angle of slope, the invention makes it possible to dynamically adjust, according to the type of particles to be spread, the degree of inclination of the downstream trap(s), making the metering device modular and versatile.

[0072] In addition, the lower end of the downstream hatch 24, when it is closed, is located substantially vertically to the horizontal axis of rotation A of the drum 221 driving the conveyor 22. In other words, the lower end of the downstream hatch 24, in the closed position, is located slightly upstream of the point from which the particles leave the conveyor 22 towards the spreading module (not shown in [Fig. 2]). For example, this end of the downstream hatch 24 is located between 0 and 100 mm upstream of the horizontal axis A in the direction of advancement D of the agricultural machine.

[0073] As already indicated, the means for controlling the position of the downstream hatch(es) 24 comprise in particular actuators, for example electric jacks, and the hatch guides are externalized relative to the hatches to limit their risk of fouling, facilitate maintenance and also provide a larger guide surface.

[0074] We will now describe, in relation to Figures 3a and 3d, two situations in which the means for controlling the position of the downstream hatch 24 of the metering device according to the invention make it possible to avoid a continuous flow situation in the presence of terrain with a positive slope in the direction of movement D. As can be seen in [Fig.3a] with a vertical downstream hatch 24 and in [Fig.3b] with an inclined downstream hatch 24, the principle lies in the fact that the downstream hatch 24 comes at least into contact with the slope formed by the particles at the slope. In this way, for the particles to fall from the conveyor towards the spreading system, a movement of the conveyor system will be necessary.

[0075] As illustrated in these figures 3a and 3b by arrows along the downstream hatch 24, the control means must therefore know the optimal position of the hatch making it possible to achieve this objective of contact between the downstream hatch 24 and the angle of slope of the particles. In these examples, the slope is positive in the direction of movement of the spreader, and the hatch(es) must therefore be less open to limit the flow of particles. For a negative slope direction in the direction of movement of the spreader, the hatch(es) must, on the contrary, be more open.

[0076] To do this, the dosing device according to the invention therefore comprises means for obtaining slope information representative of a slope of a terrain on which the agricultural machine is moving, information which is used by the control means to determine the appropriate position of the downstream hatch, via the calculation of information on the opening limit of the hatch. For this, the spreader is equipped with an inclination sensor which returns slope information, for example to a computer integrated on the machine. As detailed below, this slope information is used, directly or after processing via information processing means, by the control means to generate commands for actuating the downstream hatch(es).

[0077] As detailed below, this information takes into account a point of intersection between the slope formed by the particles and the sliding surface of the downstream trap(s). The means for controlling the position of the downstream trap(s) therefore also take into account information aT on the angle of slope of the particles to be spread, since the objective is to make the lower part of the downstream trap coincide with the particles which have a specific angle of slope depending on the type of particles. This angle of slope information corresponds for example to a parameter from a test database, for example the Applicant's Fertitest® database.

[0078] In addition, the calculation of the hatch opening limit information also takes into account the inclination of the downstream hatch, if applicable.

[0079] More particularly, and as illustrated in [Fig.4], the calculation of the coordinates (XE; YE) of the point E of intersection between the slope formed by the particles and the sliding surface of the downstream hatch(es), which determines the opening limit information follows the following formula, in a reference frame R defined by an abscissa axis extending in the plane of the conveyor and parallel to the direction of movement of the conveyor and an ordinate axis extending perpendicular to the plane of the conveyor and passing through the rear wall of the tank:

[0080] (XE; Ye) = ([Yd - YcHTana^- Tana]; YD - XE *Tanatrappe) with: • (XA; Ya) corresponding to the coordinates of axis A, in the R reference frame, of the conveyor drive drum. This parameter is known for the dosing device considered, and corresponds for example to (404; -119); • aconveyorcorresponding to the angle of inclination of the conveyor belt, preferably between 3.5° and 4.5°. This angle is also a known parameter for the dosing device considered; • a = aT + aconveyor- slope. For example, the angle of inclination of the downstream trapdoor is 52°; • (XB; Yb) = (XA+ Sina * [AB]; YA+ Cosa * [AB]) with [AB] corresponding to the radius of the drive drum 221 of the conveyor, of center A known for the dosing device considered; (Xc; Yc) = (0; YB+XB * Tana); • (XD; Yd) corresponding to the point of intersection between the rear surface 210 of the tank and the sliding surface of the downstream hatch 24. For example, this point of intersection, known for the metering device considered, has coordinates (0; 454.4).

[0081] For example, the slope information read by an inclination sensor is processed to also take into account the angle of inclination of the conveyor, before being transmitted to the processing means of the control means to calculate the opening limit information of the downstream hatch 24, according to the formula above.

[0082] According to another example, the slope information read by an inclination sensor is transmitted without processing to the processing means of the control means to calculate the opening limit information of the downstream hatch 24, according to the formula above.

[0083] According to yet another example, the information on the opening limit of the downstream hatch 24 is calculated by the spreader computer, according to the above formula, and transmitted to the control means to generate the control command(s) for the position of the downstream hatch(es).

[0084] [Fig.5] illustrates an example of a curve resulting from the calculation, from the formula above, of the position of the downstream trapdoor as a function of the slope, for a particle slope angle of 27°, and the reference values ​​detailed above. We observe, as expected, that the opening height of the downstream trapdoor (on the ordinate) decreases with the increase in the slope angle (on the abscissa).

[0085] From the observation of different curves obtained for different types of particles, and therefore different angles of slope, the inventors found that the technique could be simplified in terms of calculations, as well as in terms of movements of the downstream hatch, by defining control stages for the position of this hatch, so that a single value of opening of the hatch is associated with a range of slope values. This operation by stages is for example illustrated in [Fig.6], for three types of particles having three different values ​​of angles of slope, extracted for example from the Applicant's Fertitest® database, respectively 27° (particles = fertilizer) for curves C1 and C1bis (curve by stages), 33° (particles = Pellet) for curves C2 and C2bis (curve by stages), 45° (particles = Wet Bulk) for curves C3 and C3bis (curve by stages).

[0086] For the implementation of this embodiment by stages, the opening limit information has a coordinate value Y'E, called the stage value, identical for each value of the slope information aPenteComprise in a given interval, the stage value Y'E being less than or equal to the coordinate value YE of the equation described previously. For example, for curves Clbis and C2bis, the opening height of the downstream hatch decreases by 20% every interval corresponding to a 5° increase in the slope, starting from a slope of 5%. For curve C3bis, the opening height of the downstream hatch decreases by 36% between a slope of 10% and a slope of 15%, then by 20% every interval corresponding to a 5° increase in the slope, starting from a slope of 15%.

[0087] As already indicated, this stepwise operation makes it possible to take into account a change in the slope during the movement of the spreader, by modifying in steps, and not at each detection of a new slope angle, the opening height of the downstream trap(s), thanks to the control means of the metering device, thus limiting the movements of change in the opening height of the downstream trap(s). As a result, the precision of the particle outlet flow rate is improved, by limiting the transient phases (between two positions of the downstream trap(s), avoiding the risks of hysteresis and instability.

[0088] According to an alternative embodiment, not illustrated, the steep slope information is also representative of a slope of the terrain on which the agricultural machine is moving, so as to also take into account the effects of a slope of the terrain which may, for example, example cause an accumulation of particles on one side of the conveyor belt, thus unbalancing the volume of particles at the downstream hatch. According to this variant, the spreader comprises means for detecting the slope, for example using the inclinometer used to provide the slope information, or using another inclination sensor. Then, the slope and slope information is compiled to deliver slope information used to control the position of the downstream hatch(es), according to the present technique.

[0089] Figures 7a to 7d are now described, illustrating four situations for adjusting a downstream trap, depending on the evolution of the slope of the terrain and the implementation of the invention, according to any one of the embodiments described previously.

[0090] Thus, [Fig.7a] illustrates a situation of optimal adjustment of the opening of the hatch 24 on flat ground, showing in particular that no unwanted flow of particles takes place. [Fig.7b] illustrates a situation of optimal adjustment of the opening of the hatch 24 on slightly sloping ground, the opening of the downstream hatch 24 being unchanged compared to the situation of [Fig.7a] because the angle of the slope makes it possible to maintain the initial position of the downstream hatch 24.

[0091] If, on the other hand, we consider that the spreader continues to move and that the slope of the ground increases, the risk is to arrive at the situation illustrated in [Fig.7c], without the implementation of the invention: the hatch remains open at the same height as in [Fig.7b] and we observe a continuous flow of particles, due to the slope. Thanks to the implementation of the invention, the control means of the dosing device, upon receipt of information representative of the slope in real time, can reduce the opening of the downstream hatch and thus avoid the continuous flow of particles, then retained by the hatch whose opening has been reduced. This situation is illustrated in [Fig.7d] on which we can see that the opening of the downstream hatch 24 has been reduced to take account of the slope.

[0092] It can therefore be observed in this [Fig.7d] that the downstream hatch 24 is very slightly open, potentially causing a drop in the dose of particles spread. It is then necessary to find a compromise between avoiding a continuous flow of particles due to the steep slope and an under-dosing of the particles to be spread due to the significant closure of the downstream hatch. This compromise can be achieved, according to the invention, by providing means for regulating the speed of the conveyor as a function of the position of the hatch 24 and the slope information. Thus, it is provided, according to this embodiment, that the dosing device can slow down the conveyor belt or, on the contrary, increase its speed, as a function of the opening of the downstream hatch and therefore of the slope, in order to compensate for the effect of controlling the position of the downstream hatch. In the case illustrated in [Fig.7d], the speed of the belt could be increased by the conveyor speed regulating means (not shown) in order to . to increase the particle supply at the downstream hatch 24 and thus compensate for the small particle outlet opening, so as to restore the desired dose of particles to be spread, even in a steep slope configuration. In an inverse situation, not illustrated, of steep negative slope and large opening of the downstream hatch, the belt could on the contrary slow down in order to limit the particle supply at the downstream hatch 24 in the wide open position.

[0093] Let us return again to the example of the situation illustrated in [Fig.7d], and in the case where the speed of the belt would be adjusted and therefore increased to be able to respect the desired dose of particles. There is then a risk of compression of the particles in the dosing device, and the invention also proposes to reinforce the prevention of this risk of compression, thanks to the implementation of a tunnel for supplying the particles, for example with a height of 200 millimeters. This tunnel, not illustrated in [Fig.7d], has an inlet opening and an outlet opening, the outlet opening being controlled by the downstream hatch(es) 24 and the inlet opening being controlled by a second hatch, called the upstream hatch. Furthermore, according to this embodiment of the invention, the dosing device comprises means for controlling the opening of this upstream hatch, also taking into account the steep slope information.

[0094] Such a tunnel 26 with an upstream trapdoor 27 is for example illustrated in [Fig.8], and has the objective of limiting the risks of compression and jamming of particles at the level of the downstream trapdoor(s) 24.

[0095] According to a particular characteristic, the means for controlling the upstream hatch 26 make it possible in particular to provide a step d relative to the upper part of the tunnel. Such a step has the effect of further limiting the risk of compression of the particles at the level of the downstream hatch(es), in particular by shearing the particles which pass under the edge of the upstream hatch and by rotating them so that the particles circulate in the tunnel without hindrance, up to the downstream hatch(es) 24. For example, a step of 10 millimeters is sufficient with a wet bulk product, of the marl type without straw. In [Fig.8], the step d measures approximately 9 millimeters.

[0096] Furthermore, in order to further improve the prevention of the risk of compression and packing of particles, the metering device comprises means for detecting compression, or pressure greater than a predetermined threshold, in the tunnel, as well as means for generating an alarm, called a packing alarm, if compression is detected for a predetermined period of time. The “overpressure” can also be the consequence of the slope which overfeeds the product and creates compaction.

[0097] Several means can be envisaged to carry out this pressure detection, for example:

[0098] - in the tunnel:

[0099] - via at least one pressure sensor, such as a pressure gauge for example, or “indirectly” via a moving part activated by the rise in pressure and whose movement is detected by a simple end-of-travel sensor, for example, such as a moving shutter mounted on the upper part of the tunnel.

[0100] - via at least one weighing sensor combined with a weighing algorithm which allows to warn the driver with a prevention alarm of a risk of jamming. Such a detection algorithm could operate with two thresholds, the 2nd threshold allowing to detect a risk of jamming if it is exceeded for a predefined duration, the 1st threshold allowing to avoid too frequent alarms with a jamming ultimately not proven.

[0101] - via at least one camera placed at the exit of the tunnel, to allow the driver, if he wishes, to check that his machine is not jammed.

[0102] - at the level of the downstream hatch(es): via at least one measurement sensor power of at least one actuator controlling one of the downstream hatches and / or via at least one force sensor on the downstream hatch(es).

[0103] Finally, [Fig.9] illustrates a dosing method according to the invention, for a particle distribution system for an agricultural machine capable of moving on land, comprising a tank having in a lower part a conveyor capable of transporting the particles towards an outlet orifice of the tank, comprising at least one movable hatch capable of taking a plurality of positions between a closed position and an open position, and implementing the following steps: - a step of obtaining 90 information representing a slope of a terrain on which the agricultural machine is moving and - a step 91 of controlling the position of the downstream hatch according to the slope information-

[0104] The dosing method may have the various characteristics relating to the dosing device, described above, combined or taken in isolation.

[0105] It is also possible to control the implementation and proper functioning of the dosing method and the various means implemented, as described below.

[0106] This control can be carried out without bringing the spreader into a plot, including without the possibility of connection to a GPS or means of measuring external climatic conditions. Technical means must be available allowing simulation and sending to the spreader control console, for example to note information necessary for operation such as speed, target dose, target working width and flow rate, or the various parameters used in the equation allowing the calculation of the opening limit of the downstream hatch(es), described previously.

[0107] For example, it is sufficient to have:

[0108] - of the spreader to be tested;

[0109] - means for tilting the spreader to simulate a slope, these means advantageously allowing the angle of the slope to be modified during the inspection; these means also allowing, where appropriate, the simulation of a slope;

[0110] - means of controlling this spreader (console, etc.);

[0111] - a battery or source of electrical power to supply the actuators and the spreader control organs;

[0112] - possibly from a correctly sized hydraulic source if the means action are hydraulic organs (for example the conveyor belt and / or the hydraulic cylinders to operate the downstream and upstream hatches, etc.);

[0113] - a summary table allowing manual reading:

[0114] - spreader adjustment parameters, successively modified via the console of control of said spreader;

[0115] - actions generated by these successively modified parameters on the organs spreader keys: successive positions of the downstream hatch(es), the upstream hatch, adjustment of the angle of inclination of the downstream hatch(es), modification of the speed of the conveyor belt, etc.

[0116] Optionally, it is advisable to use a graduated ruler, or any other measuring instrument adapted to the configuration, allowing measurements of the position of said key members (in the case where the spreader is not provided with markers identifying the position(s) of said key members) and in particular of said downstream hatch(es) and the upstream hatch.

[0117] The control steps may be as follows: - set the desired dose, depending on the type of particles to be spread; - measure the positions of the downstream trap(s), with the spreader not inclined; - measure the position of the upstream trapdoor, with the spreader not inclined; - measure the speed of the conveyor belt; - tilt the spreader and identify the possible consequences of this tilt on the positions of the different traps as well as on the speed of the conveyor belt. If an action is detected, the consequence of this action is measured. For example, if the position of the downstream trap has been modified, it is already deduced that the spreader is equipped with a servocontrol of the position / opening of this trap according to the slope detected by the spreader. We can also measure the modification and compare with a curve that could be obtained from the aforementioned equation, without forget about step-by-step operation. In another example, if the speed of the belt has been changed, we can already deduce that the spreader is equipped with a control of the speed of the conveyor belt based on the slope detected by the spreader; This step can be repeated by changing the degree of inclination of the spreader.

[0118] To check the correct adjustment of the position of the downstream trap(s) depending on the type of particles, the spreader parameters can be modified, for example by directly modifying the angle of slope, and check whether this has an impact on the position of the downstream trap(s).

[0119] To check the correct operation of the means implemented to detect pressure in the particle supply tunnel, upstream of the downstream hatch(es), pressure can be applied manually or using a tool and an alarm can be generated. This check can therefore be carried out without having to load the machine with particles.

Claims

Claims

1. Dosing device (20) for a particle distribution system for an agricultural machine (200) capable of moving on land, comprising a reservoir (21) having in a lower part a conveyor (22) capable of transporting said particles towards an outlet orifice (23) of said reservoir, comprising at least one movable hatch, called downstream hatch (24), capable of taking a plurality of positions between a closed position and an open position, characterized in that it comprises means for obtaining slope information representative of a slope of land on which said agricultural machine is moving, and means for controlling the position of said downstream hatch(es) taking into account said slope information.

2. Dosing device according to claim 1, characterized in that said control means reduce the opening of said at least one downstream hatch when said slope information aP corresponds to a positive slope in the direction of movement of the agricultural machine and / or increase the opening of said at least one downstream hatch when said slope information aP corresponds to a negative slope in the direction of movement of the agricultural machine.

3. Dosing device according to claim 1, characterized in that said control means deliver information on the opening limit of said at least one downstream hatch taking into account said slope information and information aT on the angle of slope characteristic of said particles.

4. Dosing device according to claim 3, characterized in that said at least one downstream hatch is inclined relative to the plane of said conveyor, so that, in the closed position, a lower end of said downstream hatch is located substantially vertically to an axis of rotation of a drive drum of the conveyor, and in that said opening limit information also takes into account information 0^ on the inclination of said at least one downstream hatch.

5. Dosing device according to claim 3, characterized in that said opening limit information takes into account a point E whose coordinates (XE; YE) are calculated as follows, in a reference frame R defined by an abscissa axis extending in the plane of the conveyor and parallel to the direction of movement of said conveyor and an ordinate axis extending perpendicular to said plane of said conveyor and passing through the rear wall of the tank: (XE; YE) = ([Yd - Yc] / [Tanatrappe- Tana]; YD - XE *Tanatrappe) with: • (XA; Ya) corresponding to the coordinates of the axis A, in the reference frame R, of the drive drum of said conveyor (parameter known for the dosing device considered) • aœconveyorcorresponding to the angle of inclination of the belt of said conveyor (parameter known for the dosing device considered) • Ct Cty 4“ Ctconveyor Ctpente • (XB; Yb) = (XA+ Sina * [AB]; YA+ Cosa * [AB]) with [AB] corresponding to the radius of the drive drum of said conveyor, with center A (parameter known for the dosing device considered) • (XC;YC) = (O; YB+XB*Tana) • (XD ;Yd) corresponding to the point of intersection between the rear surface of said tank and the sliding surface of said at least one hatch (known parameter for the dosing device considered).;

6. Dosing device according to claim 5, characterized in that said opening limit information has a coordinate value Y'E, called the level value, identical for each value of said slope information included in a given interval, said level value Y'E being less than or equal to said coordinate value YE.

7. Dosing device according to claim 1, characterized in that said slope information is also representative of a slope of the terrain on which said agricultural machine is moving.

8. Dosing device according to claim 1, characterized in that it comprises means for regulating the speed of said conveyor taking into account the position of said at least one downstream hatch and / or said gradient information.

9. Dosing device according to claim 8 and claim 3, characterized in that said speed regulating means said conveyor take into account said opening limit information E.

10. Dosing device according to claim 1, characterized in that it comprises means for adjusting an angle of inclination of said downstream hatch(es).

11. Dosing device according to claim 1, characterized in that it comprises a tunnel (26) for supplying particles, having an inlet opening and an outlet opening, the outlet opening being controlled by said downstream hatch(es) and the inlet opening being controlled by a second hatch, called the upstream hatch (27), and in that it comprises means for controlling the opening of said upstream hatch, also taking into account said steep slope information.

12. Dosing device according to claim 11, characterized in that said means for controlling the opening of said upstream hatch act in such a way as to provide a step (d) relative to the upper part of said tunnel.

13. Dosing device according to claim 10, characterized in that it comprises means for detecting a compression, or pressure greater than a predetermined threshold, in said tunnel.

14. Dosing device according to claim 13, characterized in that it comprises means for generating an alarm, called a jam alarm, if a compression is detected, by said detection means, during a predetermined period of time.

15. Dosing device according to claim 13, characterized in that said compression detection means comprise at least one of the elements belonging to the group comprising: - at least one pressure sensor mounted in said tunnel; - at least one displacement sensor of a movable flap mounted on the upper part of said tunnel; - at least one camera placed at the outlet of said tunnel; - at least one weighing sensor mounted in said tunnel; - at least one power measurement sensor of at least one actuator controlling one of said downstream hatches, - at least one force sensor on one of said downstream hatches.

16. Dosing method for a particle distribution system for an agricultural machine capable of moving on land, comprising a tank having a conveyor in a lower part

17. capable of transporting said particles to an outlet orifice of said reservoir, comprising at least one movable hatch capable of taking a plurality of positions between a closed position and an open position, characterized in that it comprises: - a step of obtaining (90) slope information representative of a slope of a terrain on which said agricultural machine is moving and - a step (91) of controlling the position of said downstream hatch as a function of said steep slope information. Agricultural particle distribution machine, comprising a tank having in a lower part a conveyor capable of transporting said particles towards an outlet orifice of said tank, characterized in that it comprises a particle distribution system implementing a dosing device comprising at least one movable hatch, called downstream hatch, capable of taking a plurality of positions between a closed position and an open position, said device comprising means for obtaining slope information representative of a slope of a terrain on which said agricultural machine is moving, and means for controlling the position of said downstream hatch(es) taking into account said slope information.

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