ES2622078T3 - Valve unit for agricultural spraying - Google Patents

Abstract

Valve unit for agricultural spraying (4) with a primary conduit (8) and a secondary conduit (9), among which a valve body (24) by means of a spring (30) is requested against a valve seat ( 15), the valve body (24) being able to be requested with the pressure in the primary duct (8) in the opening direction (25) and being removed from the valve seat (15) when a pressure threshold value is exceeded in the primary conduit (8), characterized in that a retention magnet (34) is provided through which the valve body (24) can be moved and / or maintained in an operating position.

Description

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DESCRIPTION

Valve unit for agricultural spraying Technical field of the invention

The present invention relates to a valve unit for agricultural spraying, a valve device for agricultural spraying formed with a valve unit for agricultural spraying of this type, as well as a method for operating a valve device for agricultural spraying of this type.

Valve units for agricultural spraying and valve devices for agricultural spraying serve to control and regulate (in the context of the present invention also subsumed under "control") the dispersion of an agricultural sprayer for any purpose and for any type of construction For example, such an agricultural sprayer serves to disperse a fluid in agriculture or fruit growing or horticulture, the fluid being, for example, water, fertilizer, an insecticide or any other fluid or fluid mixture.

State of the art

Agricultural sprayers are used individually for the dispersion of an agricultural fluid over a limited surface or with various agricultural sprayers which, for example, can be attached to one another or several spray bars. Particularly for economic reasons, as well as for ecological reasons, the dispersion of the fluid should be carried out only on the really relevant agricultural surfaces and, in them, only with a required volumetric flow. To name just one example, in a spray vehicle that moves in the form of a meander over a field, the dispersion of the fluid must be interrupted in the marginal areas of the field, for example, in the course of a curve. It is also possible that in spray bar sections that do not pass over plants or crops, the sprayers associated with these sections should be temporarily deactivated. While for the complete deactivation in the marginal area of a field a central valve unit for agricultural spraying can be brought into a blocking position in a feed line for all agricultural sprayers, the deactivation of sections of a spray bar requires that A central duct of the spray bar to which the agricultural sprayers are connected is configured in a segmented manner with parallel segments that can be blocked separately by means of the valve unit for agricultural spraying associated with the corresponding segments. Finally, an activation of a valve unit for agricultural spraying can also be carried out, in addition to an opening position and a closing position, in at least one intermediate position, particularly continuous intermediate positions to be able to control the dispersion according to the needs.

Problems associated with modern agricultural sprayers, as well as solution approaches, can be extracted from the texts DE 10 2009 001 532 A1, as well as DE 696 25 914 T2. According to them, it may be desirable to change a dispersion rate with intermediate positions required of the valve unit for agricultural spraying as a function of agricultural use, of an expected drift of drops sprayed as a result of a wind, of the velocity of the spray vehicle, of the desired size of the spray zone of the agricultural sprayer, of the height of a spray bar above the ground, of a desired drop size or a desired range of drop size, of the desired fluid flow, of the angle desired of a spray cone, and the like. It is also possible that a dispersion rate control has to be carried out on the basis of a global positioning system data, for example, depending on the position in the field, the volumetric flow of the dispersion is preset, by example, based on harvest data referring to positions of the last harvest.

An influence on a volumetric flow is also known for the dispersion of an agricultural fluid by means of a control of the pumping capacity of a pump for the feeding of the fluid, a control of the pressure in a feeding conduit, an influence on a opening section of a valve unit for agricultural spraying or a use of a valve unit for agricultural spraying configured as a pulse modulation system (see DE 10 2009 001 532 A1 and DE 696 25 914 T2), being able to vary in the last mentioned case the temporary average volumetric flow through the so-called "Duty Cycle" and the relationship between the short opening times of the valve and the closing times of the valve. An interaction of the dispersion also occurs between the valve unit for agricultural spraying, on the one hand, and a spraying or diffusion unit downstream of the valve unit for agricultural spraying from which the fluid flows in the direction of the earth. agricultural or good to be sprayed with the fluid.

Valve units for agricultural spraying can be configured as directly controlled magnetic valves in which, for example, a valve body configured as a valve plate, which is located in a closed position for positioning in a valve seat, is connected directly mechanically with an actuator. In this regard, the electromagnetic actuators are formed with a coil and an anchor moved inside the coil, the mobile anchor being coupled with the valve body. The electromagnetic actuator must generate an opening force that depends on the size of the valve plate, as well as the difference in pressure between a primary conduit and a secondary conduit of the valve unit.

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agricultural spraying (see unpublished patent application DE 10 2013 101 460.7).

Document DE 10 2011 000 921 B3 discloses a valve unit for agricultural spraying that is configured as a passive overflow valve with no electronic control possibilities. In this regard, the size and geometry of a cross-sectional passage between the primary and secondary ducts depends on the position of a valve body. The valve body is formed in this case with a swinging plunger. The swinging plunger has a first plunger surface that is permanently requested with the pressure in the primary duct. In addition, the tilting plunger has a second plunger surface that acts contrary to the first plunger surface and is permanently requested with the pressure in the secondary duct. In this way, the position of the valve body and the size and geometry of the cross section of the passage depends on the difference in pressure in the primary and secondary conduits. For the start-up of an agricultural sprayer there is no pressure in the secondary conduit, so that with a pressure build-up in the primary conduit a rapid opening of the agricultural spraying valve unit is obtained. However, if there is an unwanted obstruction in the operation of the agricultural sprayer downstream of the valve unit for agricultural spraying, the fluid in the secondary conduit is stagnant, bringing the pressure applied to the second plunger surface Approaches the pressure in the primary duct that is applied to the first embolus surface. In this way, in case of an obstruction, a closure of the overflow valve of the agricultural sprayer can be automatically caused to prevent fluid from flowing from the primary to the secondary conduit.

EP 2 227 949 A1 discloses the basic construction of a field spraying facility with the complete fluid circuit and the arrangement of several valve units for agricultural spraying in a spray bar. In this case, valve units are used for agricultural spraying with a pulse width modulation control of the movement of a valve body.

Objective of the invention

The present invention is based on the objective of proposing a valve unit for agricultural spraying, a valve device for agricultural spraying with a valve unit for agricultural spraying of this type, as well as a method for operating a valve device for agricultural spraying that are improved compared to

- the electric power consumption of the electronic control,

- the cost of construction,

- the size of construction and the costs of the electronic component,

- the guarantee of protection against leaks and / or

- a purely passive operation without electronic activation of the valve unit for agricultural spraying.

Solution

The object of the invention is achieved in accordance with the invention with the characteristics of the independent claims. Other preferred configurations according to the invention are drawn from the dependent claims.

Description of the invention

The invention relates to a valve unit for agricultural spraying, which has a primary conduit that is supplied particularly by means of a pump with a fluid under pressure, and a secondary conduit through which the fluid is dispersed (particularly with a diffusion or spray unit arranged downstream). Between the primary duct and the secondary duct, a valve body and a valve seat are arranged that form a valve with a cross-sectional passage, dependent on the relative position between the valve body and the valve seat, between the primary duct and the secondary duct. The valve body is requested by means of a spring against the valve seat, whereby a closing position (or at least one operating position with a reduced cross-section) can be caused. The valve body can be requested with the pressure in the primary duct in the opening direction. The valve body, when a threshold value of the pressure in the primary duct is exceeded, is removed from the valve seat (the threshold value may also depend on other dimensions such as the pressure in the secondary duct). In this way, the valve formed with the valve body and the valve seat guarantees a kind of overflow function that, for example, can be used to be guaranteed with a start-up of the agricultural sprayer and, thus, of the Valve unit for agricultural spraying, firstly by means of the spring, a valve closing position. With increasing pressure in the primary conduit, particularly by setting the pump activity, this valve closing position is maintained first until a threshold value of the pressure in the primary conduit is exceeded. This exceeding the threshold value has the consequence that the valve is opened at least partially and a cross section is obtained which passes

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it increases and through which the fluid can flow from the primary to the secondary conduit, from which the dispersion can take place. The overflow function explained, therefore, can, on the one hand, enable passive operation of the valve unit for agricultural spraying, which can occur without any type of electronic activation.

According to the invention, a retention magnet is provided in the valve unit for agricultural spraying by means of which the valve body can be moved. In this respect, a retention magnet is understood as an electroiman in which no mechanical conversion of movement is performed. In fact, the electric retention magnet has a coil winding and a core that cannot be moved relative to the coil winding. In the VDE 0580 standard, withholding magnets of this type are also called "magnetic load elevators", which, however, as magnetic load elevators, are used with another function, specifically for securing loads, for example, for purposes of transport, and in some cases with larger dimensions.

While in principle, any form of section and construction of a retention magnet can be used in the context of the invention, in the case of the retention magnet it is particularly a casserole magnet that is essentially configured with rotational symmetry with respect to a longitudinal axis In this case, the core of the retention magnet is configured in a semi-longitudinal section with the shape of a U lying with coil coil arrangement between the two lateral arms of the U (compare also figure 1). In this regard, the lateral arm of the U that is located radially inside the U may be formed by a continuous cylindrical inner core of the retention magnet. In the free end zones of the U of the retaining magnet, the metallic object "retainer" is placed in the retaining or holding position. For the U closed in this way by the object to be held, a closed magnetic flux is obtained, which makes it possible to hold the object that must also be held with low power consumption.

By using the retaining magnet according to the invention, therefore, an object can be fastened, in this case, for example, a mobile valve body or a mobile valve seat or a mechanically coupled body in an operating position of the valve with drastically reduced power consumption in some cases compared to an electromagnet with a mobile anchor arranged inside. Retention magnets used in the context of the invention can be obtained affordably as purchase parts with various levels of electric power consumption and the characteristics of the force generated as a function of the distance between the holding magnet and the object to be held. . In addition, a retention magnet of this type can safely guarantee the operating retention position also with low power supply. An interpretation of such a retention magnet can be made in accordance with directive VDE 0580. Within the framework of the invention, the retention magnet is not used exclusively for retention, that is, the maintenance of the closed flow that is He has explained above. In fact, within the scope of the invention, the retention magnet is used by means of a certain adjustment range to generate a force that causes a movement of the valve body. According to the invention, a direct electromagnetic control takes place with the retention magnet without requiring prior electro-pneumatic control.

For a form of realization of the invention, the retention magnet is arranged such that the retention magnet with a power supply requests the valve body in the closing direction. This results in the fact that, without current supply from the retention magnet, the passive overflow function of the valve unit for agricultural spraying is effective. In addition, with current supply from the retention magnet, the valve can be closed or remain closed despite a difference between the pressures in the primary and secondary conduits, which in itself has the consequence of an opening of the valve. Thus, for example, sections can be deactivated in a spray bar by means of the power supply of individual retention magnets of several valve units for agricultural spraying or, with power supply of all the magnets of retention of the valve unit for agricultural spraying, temporarily avoiding dispersion for the entire spray bar, for example, in the course of a curve in the marginal area of a field.

For an alternative proposal, the retention magnet is arranged in such a way that, with current supply from the retention magnet, the valve body is requested in the opening direction. In this way, for example, the overflow function can be triggered with the power supply of the retention magnet also when the difference in itself between the pressure in the primary and the secondary conduit is not sufficient to bring the valve to the opening position .

It is absolutely possible that, depending on the current supply direction of the retention magnet, the valve body is requested either in the closing direction or in the opening direction, whereby control possibilities are obtained expanded.

It is possible that the retention magnet, with current supply, generates a force that acts on the valve body while the retention magnet without current supply does not exert any force on the valve body. For another proposal of the invention, however, a retention magnet can be used with "reverse activation philosophy". In this case, the retention magnet is formed with a permanent magnet. The permanent magnet exerts on the valve body a constant magnetic force that acts independently of the

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electric solicitation of the retention magnet. In order to also reduce or eliminate this permanent magnetic force by means of an electronic control, an electromagnetic force that is opposite to the permanent magnetic force can be caused with the current supply of the retention magnet.

Fundamentally, the exercise and transmission of a force on the valve body can be carried out in various ways and directly or indirectly. For a particular configuration of the valve unit for agricultural spraying according to the invention, the retention magnet exerts an electromagnetic force on an anchor. In this regard, the anchor may be formed by the valve body itself, be rigidly attached to it or mechanically coupled by means of an appropriate transmission mechanism. In this regard, the anchor can be configured specifically in terms of its geometry and its material to cause the desired characteristic of the electromagnetic force and / or permanent magnetic force that must be created by the retention magnet, also by means of the required regulation path.

It is possible that the anchor in the opening or closing position of the valve is located in the retention magnet in such a way that in the opening or closing position the electric power consumption is reduced or minimized. If the other position is maintained without power supply as a result of a spring, no electrical power is required for maintenance in one of the two operating positions and, in the other operating position the reduced or minimized power is required in the retention position Nor is energy required to change the operating position in which the retention effect of the retention magnet is used to the other operating position - in fact, in this respect, the retention effect of the retention magnet is eliminated by the elimination of the electrical request, whereby the spring causes the other operating position. Only for the change in the operating position secured by the spring to the operating position secured by the retention force, an increased electrical power is briefly required.

In the event that the anchor in the closing position is located in the retention magnet, it is advantageous if a spring and / or damping element is inserted in the force flow between the retention magnet and the valve seat. This spring and / or damping element can spring to a possible hit of the anchor in the retention magnet or dampen it, thereby preventing the development of unwanted noise and damage of the anchoring of the retention magnet and other components such as, for example, a shock sensitive control unit. In this regard, it is possible that a spring and / or damping element is disposed in the area of the contact surface between retaining magnet and anchor. However, if this spring and / or damping element is in the central area between anchor and retention magnet for the magnetic flux, the magnetic flux can be disturbed through it. It is also possible that the spring and / or damping element is integrated in the mechanical transmission path between anchor and valve body. It is also possible that the spring and / or damping element is arranged in the area of the contact surface between the valve body and the valve seat, in the valve body or in the valve seat. A possible spring and / or damping element, in addition, can also perform a tolerance compensation and avoid double adjustment, so that regardless of the manufacturing tolerances for the anchor located in the retention magnet a position is also effectively obtained Valve closure. Depending on the manufacturing deviations within the tolerance range, therefore, the spring and / or damping element is prestressed with different force in the closing position. If manufacturing tolerances are known, by means of the selected stiffness of the spring and / or damping element, the fluctuation range of the pressure force of the valve plate in the valve seat can be predefined.

For the spatial arrangement of the valve body, the valve seat, the anchor and the retention magnet there are fundamentally varied possibilities. For a particular proposal of the invention, the valve seat is arranged between the anchor and the retention magnet on one side and the valve body on the other (in a visual direction in the direction of the valve body). If necessary, for this embodiment a segment of the valve body or a coupling element is extended from a valve plate of the valve body through the valve seat for the purpose of coupling the anchor, whereby conditions are obtained Modified construction spaces. If necessary, this configuration also enables a force to be oriented in the direction of closing with the power supply of the retention magnet to the valve body. On the other hand, by means of this configuration it can be possible that the valve unit for agricultural spraying is configured with a coupling zone or a coupling plane in which the primary and secondary conduits flow and in which the valve body is extend with adjacent valve seat arrangement.

It is also absolutely possible that the retention magnet depending on the electrical request is only used to influence the position of the valve. For a particular proposal, the retention magnet is used in a multifunctional way, using this in addition to generating a force to influence the operating position of the valve, also as a sensor that (directly or indirectly) registers the operating position of the body of valve or of the valve formed with it. This configuration is based on knowledge in accordance with the invention that the position of the valve body correlates with the size of the distance between the anchor and the retention magnet. Depending on the distance between anchor and retention magnet, however, the magnetic conductivity, the magnetic resistance and the flux density are modified. If the retention magnet with a changing electrical magnitude is requested, particularly with an alternating voltage or an alternating current, the magnitudes

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electromagnetic of the retention magnet are modified as a function of the distance between the anchor and the retention magnet. For example, depending on the distance, a change in the current in the retention magnet, in the tension in the retention magnet, in the impedance of the retention magnet and / or in the phase shift is obtained. With the help of physical circumstances, a change of this type can be converted, or it can be converted by means of a characteristic field, in a distance from the anchor to the retention magnet, which finally is configured a sensor for the operating position of the valve body.

Another configuration of the invention is dedicated to the coupling of the valve unit for agricultural spraying with the additional components of the agricultural sprayer. If necessary, the agricultural sprayer has a flat coupling zone, particularly standardized, by means of which, on the one hand, the primary duct is supplied with the fluid under pressure and which, on the other hand, flows the secondary conduit in order to disperse the fluid downstream. For such a configuration, the valve unit for agricultural spraying has an essentially flat coupling area. The primary conduit and the secondary conduit flow into this coupling zone, whereby (under waterproofing), on the one hand, fluid can flow from the supply conduit of the other component to the primary conduit of the agricultural spray valve unit and, on the other hand, fluid can arrive from the secondary conduit of the agricultural spray valve unit to the evacuation conduit of the other component. It is possible that the valve body extends into the coupling area, it being possible even that, with a movement of the valve body, the valve body partially enters the evacuation conduit of the other component, which must have a cross section of the corresponding size. It is also possible that, if the agricultural spray valve unit is not yet mounted with the adjacent construction unit, components can be introduced into the housing of the agricultural spray valve unit housing through the coupling area and / or can be mounted inside the housing of the valve unit for agricultural spraying. Alternatively or cumulatively, the coupling area may be formed with both a separation and / or guide wall, and a valve seat body, preferably defining the separation and / or guide wall and the valve seat body the area of coupling. Preferably, a cross section of the primary duct flow is limited both by the separation and / or guide wall and by the valve seat body. For this configuration, the separation and / or guide wall and / or the valve seat body has a groove, which is closed in the cross section by means of the other component of the separation and / or guide wall and of the body of valve seat. This represents a particularly simple manufacturing possibility for the primary conduit, being able to manufacture, depending on the configuration of the contour of the contact area between the separation wall and / or guide and valve seat body, also angledly formed primary ducts, curved or in any other way.

Another solution of the objective on which the invention is based is made available by means of a valve device for agricultural spraying which has a valve unit for agricultural spraying such as the one explained above. It is proposed that the valve device for agricultural spraying be equipped with a control unit. The control unit has control logic by means of which the retention magnet can be operated as a sensor for an operating position of the valve body. To name only one non-limiting example of the invention, in the control unit or in a memory unit associated therewith, a characteristic is filed for a change of an impedance or a phase shift or of another relative electrical or magnetic magnitude. at the distance between the anchor and the retention magnet. The control logic generates an electrical control signal, particularly an alternating voltage, which requests the retention magnet. Finally, the control logic is properly configured to analyze a change in impedance, phase shift or other magnitude recorded as a function of the distance between the anchor and the retention magnet and generates a binary signal (open / closed ), a digital signal or an analog signal for the distance between the anchor and the retention magnet. It is possible that the control unit equipped with this control logic is integrated in the valve unit for agricultural spraying, which as a module is fixed from outside to a housing of the valve unit for agricultural spraying or that is arranged externally to the unit of valve for agricultural spraying with communication between the control unit and the valve unit for agricultural spraying by means of a unidirectional or bidirectional cable, a wire harness or something similar. It is possible that a joint control unit is responsible for several valve units for agricultural spraying, this control unit may be integrated in one of the valve units for agricultural spraying, and may be provided as a module in the housing of the valve unit for agricultural spraying or may be configured as a decentralized control unit that can then be arranged at a distance from the valve units for agricultural spraying.

Another solution of the objective on which the invention is based is given by means of a procedure for the operation of a valve device for agricultural spraying of the type explained above. In accordance with this procedure, the control device with appropriate control logic generates an electrical signal requesting for the retention magnet that causes a force acting on the body as a function of the desired flow through the agricultural spray valve unit. of valve and that influences a working position of the valve body. In this regard, it is possible that the electrical request signal is configured as an electrical binary request signal by means of which the opening position or the closing position can be caused. However, it is also absolutely possible that the electrical request signal generates gradual or continuous forces of the retention magnet by means of which it can / can

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cause one, several or continuous intermediate positions of the valve. In this regard, the electrical request signal can be controlled or regulated by the control device, particularly using the distance, calculated by the retention magnet in its function as a sensor, between the anchor and the retention magnet.

Furthermore, for this solution according to the invention, the control unit (or other control unit) analyzes the magnetic flux that depends on the distance between the anchor and the retention magnet, which can be done, as explained above. , for example, by detection and analysis of an impedance, a phase shift or something similar. The analysis is performed to calculate the distance between the anchor and the retention magnet.

The calculation of the distance between the anchor and the retention magnet (and, thereby, the valve's operating position) can be done for any purpose. To name just one non-limiting example, the calculated distance can be used for a regulation of the valve's operating position. For a particular embodiment of the invention, the analysis of the calculated distance between the anchor and the retention magnet is performed for the detection of a malfunctioning state of the agricultural spraying facility. This is explained with the help of the following non-limiting examples:

- If the pressure drops in the primary duct, particularly due to a malfunction of a pump or a leak in a feed duct, this is expressed in the purely passive overflow function of the agricultural spray valve unit in which the body Valve moves in the direction of the closing position, so it is associated that the distance between the anchor and the retention magnet is reduced. With this, the inadequate supply of the primary conduit can be deduced by analyzing the distance.

- If the position of the valve body also depends on the pressure in the secondary conduit, an obstruction of the secondary conduit, an obstruction of a conduit downstream of the secondary conduit or an obstruction of a spray or diffuser nozzle also causes a modified position of the body of valve, which causes a modified distance between the anchor and the retention magnet, such that by means of the distance an obstruction of this type can be detected.

- The corresponding thing should be noted regarding an impediment to a movement of the valve body, particularly as a result of wear or as a result of a foreign body in the guide area of the valve body or between the valve seat and the valve body .

In preferred configuration of the process according to the invention, the control unit generates a non-stationary electrical control signal (it is particularly a dynamic control signal with preferably periodically changing signs such as, for example, an alternating voltage). With this control signal, the retention magnet is requested. The control unit calculates the distance between the anchor and the retention magnet by means of a change in the current in the retention magnet, the tension in the retention magnet, the impedance of the retention magnet and / or a phase shift in the retention magnet as a function of the distance between the anchor and the retention magnet.

If, for example, the retention magnet is requested with a control signal in the form of a voltage change, this tension change has the consequence that the anchoring and, with it, the valve body are requested by the retention magnet with an oscillating force that changes its direction. To avoid that, as a result of this force, the operating position of the valve body is modified to an undesired extent, there are particularly the following possibilities:

- The application with the electrical control signal is carried out in the anchor retention position, in which the anchor itself is subject to a relatively large retention force in the retention magnet, such that a lower oscillating force as a result of the electrical control signal does not cause the anchor to detach from the retention magnet.

- If the retention magnet is configured without permanent magnet, in this retention position the non-stationary electrical control signal is superimposed on the electrical request signal that must guarantee the retention position. In this respect, the amplitude of the electrical control signal is smaller than the electrical request signal. If, on the other hand, the retention magnet is configured with a permanent magnet, in the retention position guaranteed by the permanent magnet, the electric control signal acts exclusively.

- For any electrical request signals to cause a desired position of operation of the valve, an electrical control signal may be superimposed on the request electrical signal. In this regard, the amplitude of the control signal is preferably (in orders of magnitude) less than the amount of the electrical request signal, which is preferably not oscillating and does not change its sign, but which, for an operating position of The temporarily modifiable valve can also be configured with a curved shape or it can be configured with jumps.

- Alternatively or additionally, it is possible that the electrical control signal has a frequency of such a type that the control signal specifically causes a flow through the retention magnet and the anchor that depends on the

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distance between anchor and retention magnet. However, as a result of the inertia of the anchor and the valve body, the valve is not capable, in accordance with the high frequency of the control signal and the high frequency force of the retention magnet generated by it, to produce a significant change or oscillation of the position of the valve body.

Advantageous improvements of the invention are drawn from the claims, the description and the drawings. The advantages mentioned in the description and combinations of various characteristics are only examples and can take effect alternatively or cumulatively without the advantages having to be achieved necessarily by embodiments according to the invention. Without changing the object of the appended claims, as regards the content of the disclosure of the original patent application documents, the following applies: additional features can be extracted from the drawings -particularly from the geometries represented and the relative dimensions of several components with each other, as well as their relative arrangement and combination of effects. The combination of features of different embodiments of the invention or features of different claims is also possible divergently from the selected relationships of the claims and, thereby, is stimulated. This also refers to those features that are represented in separate drawings or mentioned in their description. These characteristics can also be combined with characteristics of different claims. In the same way, features presented for additional embodiments of the invention can also be suppressed.

The characteristics mentioned in the claims and the description, in reference to their number, should be understood in such a way that that number is given exactly or a number greater than the number mentioned without requiring an explicit use of the adverbial locution "at least" . Therefore, if, for example, one speaks of an element, this should be understood as having exactly one element, two elements or several elements. These characteristics can be complemented with others or be the only characteristics of which the manufactured in question is composed.

The reference numbers contained in the claims do not represent a limitation of the extent of the objects protected by the claims. They are only at the service of making claims more easily understandable.

Brief description of the drawings

Next, the invention will be explained and described further with the aid of preferred embodiments shown in the figures.

Figure 1 shows in a longitudinal section a valve unit for agricultural spraying in a closed position.

Figure 2 shows in a longitudinal section the valve unit for agricultural spraying according to figure 1 in an opening position.

Description of the figures

Figure 1 shows a fragment of an agricultural sprayer in which a component 2 is joined by means of

a union nut 3 with a valve unit for agricultural spraying 4. Component 2 has a

feed duct 5 which is supplied by means of a pump with a fluid under pressure, as well as an evacuation duct 6 that is connected to a dispersion opening or spray and / or diffusion unit for the extraction of the fluid. The valve unit for agricultural spraying 4 has an essentially flat coupling area 7 by means of which, under waterproofing, the supply line 5 is connected with a primary line 8 of the valve unit for agricultural spraying 4 and the line from

evacuation 6, with a secondary conduit 9 of the valve unit for agricultural spraying 4. The zone of

coupling 7 is oriented transversely to a longitudinal axis 10 of the valve unit for agricultural spraying 4 and is arranged radially inside the union nut 3.

The valve unit for agricultural spraying 4 has a valve 11 which in this case is configured as an overflow valve 12. In addition, the valve unit for agricultural spraying 4 has an actuator 13.

The valve 11 has an insert 14 that is fixedly fixed in a housing 19 of the valve unit for agricultural spraying 4 and forms a valve seat 15. For the exemplary embodiment shown, the insert is configured in two parts with a separation wall and / or guide 16 and a valve seat body

17. In this regard, the separation wall and / or guide 16 radially inside forms a perimeter annular collar

18. By means of the union nut 3, which is screwed radially inside with component 2 and overlaps an annular collar oriented radially out of the housing 19 of the agricultural spray valve unit 4, the annular collar 18 is tensioned between the front sides of component 2 and the housing 19 of the valve unit for agricultural spraying 4, whereby the separation wall and / or guide 16 is fixed.

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As shown, between the separation wall and / or gma 16 and component 2, a gasket 20 can be arranged which waterproofs in the coupling area the feed duct 5 and the primary duct 8 outwards. The separation and / or guide wall 16 has a recess 21 oriented in the direction of the longitudinal axis 10 in which the valve seat body 17 is housed, forming the primary conduit 17. In the coupling area 7, between the body of valve seat 17 and component 2, is radially inside the feed duct 5 and the primary duct 8 an additional joint element 20. Both the separation and / or guide wall 16 and the valve seat body 17 they have a continuous recess 22, 23 through which a valve body 24 extends. In this regard, the valve body 24 is guided with respect to a movement in the direction of the longitudinal axis 10 in an opening direction 25 and a direction of closure 26 through the recess 22. In addition, a waterproofing occurs by means of a joint element 27 that acts between the valve body 24 and the separation and / or guide wall 16. The dimension of the recess 23 is ma yor that the cross-section of the valve body 24 in the partial area that extends through the recess 23. The valve body 24 forms in the final area oriented towards the component 2 which is arranged in the coupling area 7 a plate of valve 28. On the side facing the valve seat 15, the valve plate 28 carries a spring and gasket element 29. For the embodiment shown, the spring and gasket element 29 is formed with a lining of the plate 28 valve with an elastomeric material. The valve seat 15 is formed by the insert of the valve seat body 17 which limits the recess 23, oriented to the valve plate 28, since the diameter of the recess 23 is smaller than the outside diameter of the valve plate 28. On the valve body 24 a spring 30 acts in the direction of closing. A spring base of spring 30 is supported on the separation wall and / or guide 16, while the other spring base of spring 30 is supported on the body of valve 24, in this case indirectly with intercalation of an anchor 31.

The anchor 31 is configured in the form of a lying T, the horizontal arm of the T forming an anchor piece 32 that is oriented vertically to the longitudinal axis 10, and the vertical arm of the T forming a fixing piece 33 oriented coaxially to the axis longitudinal 10. For the exemplary embodiment shown, the valve body 17 is screwed with the final area oriented to the valve plate 28 in the fixing piece 33 of the anchor 31. Expressed in another way, with the anchor 31 and the body of valve 24 is formed in the longitudinal section according to the figures in a very simplified manner a kind of H, the anchoring part 32 forming the left vertical arm of the H, the horizontal arm of the H being formed by the fixing piece 33 and a part of the valve body 24, and forming the right vertical arm of the H, which is formed much shorter than the left vertical arm of the H formed by the anchoring piece 32, the valve plate to 28. Insert 14 is traversed in the area of recesses 22, 23 by the horizontal arm of H.

The secondary conduit 9 is formed in this case radially on the outside by the valve plate 28 and in case of flow from the feed duct 5 to the evacuation duct 6 for valve 11 open downstream of the cross-sectional passage between the plate of valve 28 and the valve seat 15. For the exemplary embodiment shown, the supply line 5 has a cross section of such a type that the valve plate 28 can enter with a movement in the direction of opening 25 partially in the line of food 5.

The function of the valve 11, without interaction with the actuator 13, is as follows:

Without pressing the feed line 5 and the primary line 8, the valve 11 is in accordance with Figure 1 in a closed position, since the valve plate 28 is requested by means of the spring 30 in the closing direction 26, so that the valve plate 28 with the spring and gasket element 29 is pressed into the valve seat 15 by waterproofing. With the start-up of the agricultural spraying installation, particularly with the incorporation of the pumping capacity of a pump for the fluid supply of the feed duct 5, the pressure fed by the primary duct 5 of the control surface in the form of annular of the valve plate 28, whereby a fluid opening force acts on the valve plate 28 If the evacuation duct 6 is put under pressure, a closing force acting oppositely to the opening force is actuated means of the pressure in the discharge duct 6 on the outer surface of the valve plate 28. With increasing pressure in the feed duct 5 and the primary duct 8, the opening force increases. When a pressure threshold value is exceeded in the primary conduit 8, which depends on the pressure in the secondary conduit 9 and the evacuation conduit 6, as well as the rigidity and possible prestressing of the spring 30, the opening force is sufficient to move the valve body 24 in the opening direction 25, thereby forming a cross-sectional passage between the valve plate 28 and the valve seat 15, as shown in Figure 2. In this opening position, you can fluid from the feed duct 5, through the primary duct 8, the cross section formed between the valve plate 28 and the valve seat 15, the secondary duct 9 and the evacuation duct 6. Correspondingly, a reduction of the pressure in the supply line 5 causes a reduction of the opening force, so that, when falling below a threshold value, the valve 11 automatically occupies its closing position.

Additionally, the operating position of the valve 11 can be influenced by means of the actuator 13. This has a retention magnet 34, which in the figures is only schematically represented. The retention magnet 34 does not have any anchor for itself, but is formed by a rigid core 35 in which windings of a coil 36 are integrated. For the retention or holding position represented in Figure 1, which corresponds with the closing position of the valve 11, the anchor 31 is positioned with the front surface oriented

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

60

65

towards the insert 14 on the front surface of the core 35 of the retaining magnet 34, whereby (at the margin of the junction between the core 35 and the anchoring piece 32) a flow is obtained around the semi-longitudinal section of the coil 36 closed magnetic between the metal core 35 and the anchoring piece 32. With relatively small electrical power consumption of the coil 36, the valve 11 can therefore be maintained in its closed position regardless of the pressure in the supply line 5 and the primary conduit 8. If, on the contrary, the valve 11 is in the opening position according to Figure 2, a power supply of the holding magnet 34 can be used to move the anchor 31 in the closing direction 26 towards the holding magnet 34 until the valve 11 has reached its closing position and the anchoring piece 32 is located in the core 35 of the holding magnet 34. For the movement of the anchor 31 out of the position of a due to the gap 37 between the anchoring piece 32 and the core 35, an electrical request of the coil 36 is higher than in the closed position, in which the gap 37 is closed.

The retention magnet 34 is integrated inside the housing 19. For the embodiment shown, the retention magnet 34 is screwed with a wall 38, oriented transversely to the longitudinal axis 10, of the housing 19. A magnet assembly of retention 34, of the anchor 31, of the insert 14 and of the valve body 24 is carried out in this order from the side oriented to the component 2 in the assembled state. A cable 39, by means of which the electrical request of the coil 36 is made, is guided by a recess 40 of the wall 38 outside the housing 19. For the exemplary embodiment shown, the valve body 24 is configured like a kind of screw, the valve head 28 forming the screw head. On the side opposite the valve seat 15, the valve plate 28 forms an attack surface for a tool, particularly a screwdriver, which enables the screw body of the valve body 24 to be anchored 31.

Without power supply of the holding magnet 34, the valve unit for agricultural spraying 4, said in a simplified manner, is a conventional passive overflow valve 12. With activation of the holding magnet 34, a closing position of this overflow valve 12 can be forced. The power consumption of the holding magnet 34 is preferably from 1 to 5 watts, particularly from 2 to 3 watts.

If an obstruction occurs downstream of the secondary conduit 9, for example, as a result of an obstruction of a diffusion or spray unit, this results in the same pressure being established in the primary conduit and in the secondary conduit, thereby that the force exerted on the valve plate 28 is reduced in the direction of opening, such that the valve body 24 and, with it, the anchor 31, moves at least partially in the direction of closure 26. In this way, anchor 31 without obstruction has a different position than with obstruction. If, for example, a pressure signal of the primary side is presented, and in a control unit it is known that position acquires the anchor 31 with an agricultural sprayer in operation with this pressure of the primary side, by comparing the position of the anchor 31 calculated by By means of the sensor function of the retaining magnet 34 with the known position of the anchor 31 without any obstruction, it can be calculated by means of the control unit if an obstruction occurs.

Reference List

 one

 Agricultural sprayer

 2

 Component

 3

 Union nut

 4

 Valve unit for agricultural spraying

 5

 Feeding duct

 6

 Evacuation duct

 7

 Coupling area

 8

 Primary duct

 9

 Secondary duct

 10

 Longitudinal axis

 eleven

 Valve

 12

 Overflow valve

 13

 Actuator

 14

 Insert

 fifteen

 Valve seat

 16

 Separation wall and / or guide

 17

 Valve seat body

 18

 Annular collar

 19

 Case

 twenty

 Joint element

 twenty-one

 Recess

 22

 Recess

 2. 3

 Recess

 24

 Valve body

 25

 Opening address

 26

 Closing address

27

28

29

30

31

32

33

3. 4

35

36

37

38

39

40

Joint element

Valve plate

Spring and seal element

Spring

Anchorage

Anchor piece

Fixing piece

Withholding magnet

Core

Coil

Interstice

Wall

Cable

Recess

Claims (15)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 55 60 65 1. Valve unit for agricultural spraying (4) with a primary duct (8) and a secondary duct (9), among which a valve body (24) by means of a spring (30) is requested against a seat valve (15), the valve body (24) being able to be requested with the pressure in the primary duct (8) in the opening direction (25) and being removed from the valve seat (15) when a pressure threshold value is exceeded in the primary conduit (8), characterized in that a retention magnet (34) is provided through which the valve body (24) can be moved and / or maintained in an operating position. 2. Valve unit for agricultural spraying (4) according to claim 1, characterized in that with power supply of the retention magnet (34) the valve body (24) is requested in a closing direction (26). 3. Valve unit for agricultural spraying (4) according to claims 1 and 2, characterized in that with power supply of the holding magnet (34) the valve body (24) is requested in an opening direction (25 ). 4. Valve unit for agricultural spraying (4) according to one of the preceding claims, characterized in that the retention magnet (34) is configured with a permanent magnet that exerts a permanent magnetic force on the valve body (24) , being able to cause by feeding with current the retention magnet (34) an electromagnetic force that is opposite to the permanent magnetic force. 5. Valve unit for agricultural spraying (4) according to one of the preceding claims, characterized in that the retention magnet (34) exerts an electromagnetic force on an anchor (31). 6. Valve unit for agricultural spraying (4) according to claim 5, characterized in that the anchor (31) is located in an opening or closing position in the retention magnet (34). 7. Valve unit for agricultural spraying (4) according to claim 6, characterized in that the anchor (31) is located in the closed position in the retaining magnet (34), being interspersed in the flow of force between the retaining magnet (34) and the valve seat (15) a spring and / or damping element (29). 8. Valve unit for agricultural spraying (4) according to one of claims 5 to 7, characterized in that in a direction of operation of the valve body (24), the valve seat (15) is arranged between a) the anchor (31) and the retention magnet (34) Y b) the valve body (24). 9. Valve unit for agricultural spraying (4) according to one of the preceding claims, characterized in that the retaining magnet (34) is also used as a sensor for the detection of an operating position of the valve body. 10. Valve unit for agricultural spraying (4) according to one of the preceding claims, characterized in that there is an essentially flat coupling area (7) a) into which the primary duct (8) and the secondary duct (9) flow, b) in which the valve body (24) extends, c) by means of which, without assembly of the valve unit for agricultural spraying (4) with an adjacent construction unit (2), which has a supply duct (5) and an evacuation duct (6) which is must be connected to the primary duct (8) and the secondary duct (9) of the valve unit for agricultural spraying (4), at least one construction element can be inserted inside a housing (19) of the unit valve for agricultural spraying (4) and / or can be mounted inside the housing (19) of the agricultural spraying valve unit (4) and / or d) that it is formed with a separation and / or guide wall (16), as well as a valve seat body (17), preferably a cross-sectional flow section of the primary conduit (8) being limited both by the wall of separation and / or guide (16) as per the valve seat body (17). 11. Valve device for agricultural spraying with a valve unit for agricultural spraying (4) according to one of the preceding claims, characterized in that a control unit is provided which is equipped with control logic, through which the retention magnet (34) can be operated as a sensor for an operating position of the valve body (24). 12. Procedure for the operation of a valve device for agricultural spraying according to claim 11, characterized in that a) one or the control unit generates, depending on the desired flow through the valve unit for agricultural spraying (4), an electrical request signal for the retention magnet (34) with which it influences an operating position of the valve body (24) and b) a control unit or the control unit analyzes a magnetic flux that depends on the distance between the 5 anchor (31) and the retention magnet (34) to calculate the distance between the anchor (31) and the retention magnet (34). 13. Procedure for the operation of a valve device for agricultural spraying according to claim 12, characterized in that an analysis of the calculated distance between the anchor (31) and the retention magnet (34) is performed for the detection of a malfunctioning state of an installation of 10 agricultural spraying, particularly an incorrect function of a pump, an obstruction of a duct, an impediment to the movement of the valve body (24) and / or an obstruction of a spraying or diffusion unit. 14. Procedure for the operation of a valve device for agricultural spraying according to claims 12 or 13, characterized in that the control unit generates a non-electric control signal stationary with which the retention magnet (34) is requested, and the control unit calculates the distance between the anchor (31) and the retention magnet (34) by means of a change of the current in the retention magnet ( 34), of the tension in the retention magnet (34), of the impedance of the retention magnet (34) and / or a phase shift in the retention magnet (34). twenty 15. Procedure for the operation of a valve device for agricultural spraying according to claim 14, characterized in that the electrical control signal is superimposed on a stationary electrical request signal.