WO2019048448A1

WO2019048448A1 - Valve assembly for a spray machine

Info

Publication number: WO2019048448A1
Application number: PCT/EP2018/073807
Authority: WO
Inventors: Harald Wiessmann; Jürgen Kist; Rudolf Tigges
Original assignee: Altek Ges. Für Allgem. Landtechnik Mbh
Priority date: 2017-09-06
Filing date: 2018-09-05
Publication date: 2019-03-14
Also published as: DE102017120545B4; EP3678482A1; DE102017120545A1

Abstract

The invention relates to a valve assembly (30) for a spray machine (10), in particular for agricultural machines (12) or self-propelled plant protection devices, comprising a first valve that can control a flow volume of a spraying product (20) according to a valve position, a first electrically operated actuator (40) for setting the valve position and an energy store (78) that provides electrical energy for operating the actuator (40). The valve assembly (30) further has a charging circuit (102) for charging the energy store (78) and a control and evaluation unit (80). The control and evaluation unit (80) is configured to control a charging operation of the energy store (78) so that a charging time and a charge build-up of the energy store (78) are linear to each other.

Description

Valve assembly for a spraying machine

The present invention relates to a valve assembly for a spraying machine,

in particular for agricultural machines or self-propelled plant protection devices, comprising a first valve which can control a flow rate of a spray in response to a valve position, a first electrically operated actuator for adjusting the valve position and an energy storage, which provides electrical energy for operating the actuator.

Such a valve assembly is known from DE 10 2010 051 580 A1.

Furthermore, the present invention relates to a control unit for controlling a

Spraying machine with a variety of valve assemblies and a corresponding method and computer program. In agriculture, the reliability of individual device components plays a major role. All device components are exposed during operation, such as in a field, strong mechanical vibrations. The device components must be robust against such mechanical vibrations to ensure a long service life. This is particularly necessary because repairs at the site of the agricultural machine are not or difficult to carry out. Thus, in difficult cases often the operation for repair purposes must be stopped altogether.

For spraying fields with a spray, injection molding machines

used, which have a plurality of spray nozzles. The respective spray is discharged by means of the spray nozzles on the field. The spray can be, for example, crop protection or fertilizer. Typically, the spray nozzles are arranged on a boom of the spraying machine. This boom has a very large width, so that the largest possible area can be sprayed in a short time. It follows that a large number of spray nozzles are needed at the same time, which are arranged uniformly along the boom. The spraying machine has both the boom and an agricultural machine. The boom is attached directly to the agricultural machine or is located on a trailer that is pulled by the agricultural machine.

The flow rate of a spray is controlled via the nozzles upstream valves. As described in the aforementioned DE 10 2010 051 580 A1, it is advantageous to control the individual valves electronically. An electronic control possibility of the spray nozzles on the arms offers the advantage that they can be controlled very quickly and thus can be set very quickly along the boom, if and how strong the spray is to be delivered. This can be sprayed very efficiently and prevented that already sprayed arable land are splashed again when the spraying machine turns or avoids an obstacle. In addition, valves with electric actuators can be easily controlled individually, resulting in a very accurate and individual control results.

To prevent an on-board system of an agricultural machine from being overloaded when all

Valves are actuated at the same time, energy storage devices are provided at the valves. hen, so that an actuator can immediately remove energy from the energy storage when needed and does not need to remove energy directly from the power supply of the agricultural machine. In this way, peak current values in the power supply can be prevented. After a control of the valve, the energy store is recharged from the power supply, preferably over a charging period, which is substantially longer than the discharge time when operating the actuator. For this purpose, a much lower current can be drawn from the power supply than would be needed in a direct operation of the valve via the power supply. The amount of power required for each energy storage to charge can also be adjusted depending on an available charging time.

In known systems, the charging process, in particular the power consumption, essentially determined by the physical properties of the energy storage device. It has been shown that an uncontrolled charging of the energy storage can lead to a strong heating this, which can lead to failure of the energy storage. In addition, the aging process of the energy storage is greatly accelerated by the heating.

It is therefore an object of the present invention to provide a valve assembly that ensures a reliable and safe application in the agricultural sector, allows rapid switching of individual valves and allows a long life of the components involved.

According to one aspect of the present invention, this object is achieved by a

Solved valve assembly of the aforementioned type, which has a charging circuit for charging the energy storage and a control and evaluation, wherein the control and evaluation unit is adapted to control a charging of the energy storage, so that a charging time and a charge structure of the energy storage are linear to each other ,

The new valve assembly thus has a charging circuit for charging the

Energy storage and a control and evaluation, the charging of the Energy storage controls to allow a controlled charging of the energy storage. By allowing the charging process to be controlled, the process can be customized for each valve assembly. In particular, the charging process can be changed to respond to specific circumstances. For example, the state of charge of all valves must not fall below a critical level in order to ensure a fail-safe function. The control and evaluation unit together with the charging circuit can influence the critical level as well as vary the overall "recharging area" of the valve assembly. In addition, it is also possible to dynamically adapt the charging process, ie during operation, in order to be able to react to changed conditions during the spraying process.

Advantageously, the control and evaluation unit adjusts the charging process of the energy storage so that a charging time and the charge build-up are linear to each other. In preferred embodiments, this is achieved by the control and evaluation unit via the charging circuit adapts a resistor to the charging voltage. In this way, a charging current can be advantageously limited and a strong heating of the energy storage can be avoided. In addition, the degressive behavior of the charging voltage can be advantageously compensated, whereby a linear charging curve is made possible. In preferred embodiments, this can reduce the charging time of a complete charge to less than 10 s.

From the possibility to control the charging of the energy storage of a valve assembly, thus, there are the advantages that recharging can be accelerated and thus a faster valve circuit is enabled. At the same time, the charging process can be optimized to the extent that the energy storage heat less and thus premature aging can be reduced. In addition, the charging current can be advantageously adapted, so that the energy required for the charge of the energy storage can be adapted to the power supply of an agricultural machine. Thus, a reliable and safe application in the agricultural sector is guaranteed, allowing rapid switching of the individual valves and allows a long life of the components used. The object mentioned above is thus completely solved. In a preferred embodiment, the energy store is a series circuit of a plurality of electrical capacitors.

This embodiment makes it possible to interconnect several smaller capacitors as energy storage. Smaller capacitors are cheaper and easier to cool due to the increased surface area. Since the charging current must flow from one capacitor to the other in a series connection, the charging time of the entire energy store is generally extended. However, this can advantageously be compensated by a dynamic charging process, as achieved by the charging circuit and the control and evaluation unit. The design thus contributes advantageously to an optimization of the overall system.

In a further embodiment, the charging circuit is designed to limit a charging current to the energy storage.

The charging circuit limits the charging current to a defined value, so that the charging of a plurality of energy stores of different valve assemblies can be adapted to the existing power supply. In addition, can be advantageously excluded by this configuration in particular an overload of the power supply.

In a further embodiment, the charging circuit has an active power control.

In this embodiment, the charging process is thus realized with an active module, preferably an integrated circuit. An active energy control effectively prevents overvoltages to the energy storage during the charging process. In addition, the active power controller may be implemented as a fully integrated single chip solution that provides additional control mechanisms, monitoring functions, or protection devices for charging a plurality of capacitors in addition to charging current limiting. An active power controller can thus increase safety and functionality while at the same time building a charging circuit as well their control can be simplified via a separate control and evaluation.

In an alternative embodiment, the charging circuit has a passive

Energy control on.

In this embodiment, the power control is advantageous from discrete components

built up. This has the advantage that the charging circuit can be realized inexpensively. For example, current limiting may conveniently be accomplished by means of PWM, i. done using an FET and a storage choke. Alternatively, a current regulation can be realized by means of LDO. However, a SEPIC regulator is particularly preferably used in order to minimize energy losses during the charging process. In addition, a passive energy control can also be robustly protected against external influences, which in total allows a more robust charging circuit.

In a further embodiment, the control and evaluation unit is adapted to the

Valve position of the first valve to measure and report.

In this embodiment, the valve position, ie a certain position of the

Valve tappets, monitored by GMR sensors and reported to a higher-level unit. In particular, the control and evaluation unit can use sensors to determine whether the valve tappets have traveled through a defined point. The advantage of this embodiment is that the functionality of the individual valve of the valve assembly can be easily checked, whereby the reliability of the valve assembly can be further increased.

In a further refinement, the control and evaluation unit is set up to determine and report a temperature at the energy store.

In this embodiment, the control and evaluation unit thus has a

Possibility to determine the temperature at the energy storage via a temperature sensor. The temperature sensor may be a separate sensor. your, which is structurally arranged in the vicinity of the energy storage or about an integrated in the control and evaluation unit sensor which is adapted to determine the temperature in the environment of the control and evaluation unit, which for this purpose in the vicinity of Energy storage is arranged. The latter embodiment is advantageous because many commercial microcontrollers that can be used as a control and evaluation, temperature sensors are already integrated and thus no additional component is needed.

In a further embodiment, the control and evaluation unit is adapted to the

To load energy storage depending on an expected valve activity.

In this embodiment, the control and evaluation unit is thus adapted to the

Load energy storage dynamically while considering parameters that are not directly related to the physical load. One such parameter is the anticipated valve activity, which may be predicted using a so-called field map. Valve activity indicates when and how long a nozzle is on and thus how often the valve must be turned on and off. The embodiment thus has the advantage that the charging process is not only determined by physical parameters, but also parameters from the course of the injection process can be considered.

In a further embodiment, the valve assembly further comprises a second valve and a second electrically operated actuator to control the flow rate of the spray, wherein the energy storage is adapted to provide energy for operating the first and the second actuator.

In this embodiment, the valve assembly has at least one other valve to control the flow rate through the same or another nozzle. The energy that is necessary for operating the further actuator advantageously comes from the same energy store, so that only one energy store is required for a plurality of valves. This has the advantage of a flexible and at the same time compact design of the valve assembly. In a preferred embodiment, the valve assembly has a second control and evaluation unit for controlling the second actuator, wherein the second control and evaluation unit of the first control and evaluation unit is subordinate.

In this embodiment, the valve assembly thus has a separate control and evaluation unit for the second valve and the second electrically operated actuator. The further control and evaluation unit is subordinate to the first control and evaluation unit, so that common functions can be performed by the first control and evaluation unit, whereby the second control and evaluation unit can be made more favorable. Advantageously, the first and the second control and evaluation unit work together as a master-slave combination.

In a further preferred embodiment, the first control and evaluation unit has a bus interface for communication with a bus, wherein the second control and evaluation unit accesses the bus via the bus interface of the first control and evaluation unit.

In this embodiment, therefore, only the first control and evaluation unit for

Communication is formed with a higher-level control. The second control and evaluation unit, however, is connected to the first control and evaluation via a simple communication channel, via the communication interface of the first control and evaluation unit, a communication of the second control and evaluation is possible with a higher-level control. This embodiment allows a particularly simple wiring, since the valve assembly only has to have a single connection to a communication bus, and yet several valves can be advantageously controlled individually.

In a further embodiment, the valve assembly has a housing with a first housing part and a second housing part which is separate from the first housing, the spray means being conveyed limitedly through the first valve by the first housing part and the control and evaluation unit and the first housing in the second housing part electric actuator are arranged. In this embodiment, a housing of the valve assembly is modular. By a first housing part, the spray is conveyed, while in a separate second housing part, the electronics is arranged. The embodiment has the advantage that the electronics are effectively separated from the spray. In addition, the individual housing parts can be made of different materials, which are suitable for the respective application.

In a particularly preferred embodiment, the energy store for cooling by the spray means is arranged on a wall of the first housing part.

This embodiment has the advantage that the energy storage is heated less not only by the new charging circuit, but also the energy storage can be actively cooled. Since usually a large amount of spray is carried along for an injection process, the spray heated only slightly, so that it can be used for effective cooling. By the energy storage are arranged directly on a wall of the first housing part, the energy storage are in the immediate vicinity of the spray and are cooled by this. This has the advantage that the life of the energy storage is further advantageously increased, since the ambient temperature of the energy storage can be reduced overall.

In a further embodiment, the valve assembly can be used in a composite with other valve assemblies, and the control and evaluation unit is adapted to receive a signal representing a charging priority of the valve assembly in the composite to load the energy storage in response to the signal.

In this embodiment, the valve assembly is thus advantageously usable in a system which has a plurality of valve assemblies. By setting a charging priority, the energy stores can advantageously be charged so that they are only slightly loaded. For example, at a low priority, the energy store can only be charged slowly, so that it heats up only slightly. The Life and reliability of the energy storage can be increased so advantageous.

According to a further aspect of the present invention, the above-mentioned object is further achieved by a control unit for controlling an injection machine having a plurality of valve assemblies, wherein the control unit is configured to determine the charge states of the energy stores of the plurality of valve assemblies and a charging process of the energy storage in Control dependence of the charge states.

It is thus an idea to use a plurality of valve assemblies and to control them via a central control unit. In this case, the states of charge of the individual energy stores of the valve assemblies are read out and controlled as a function of the states of charge, the individual charging processes of the energy stores of the valve assemblies.

In a preferred embodiment, the control unit is adapted to a

Prioritize the energy storage based on the states of charge and submit the prioritization to the valve assemblies.

The control unit thus prioritizes the charging processes on the basis of the current charge states, wherein the control of the charging operations is advantageously carried out by the valve assemblies or the control and evaluation units contained therein, so that the control unit only has to transmit the prioritization to the valve assemblies.

In a further embodiment, the control unit is designed to use the state of charge to determine a change in a pre-calculated valve activity and to report the change to a master computer.

In this embodiment, the control unit may additionally or alternatively to the prioritization of the charging processes also determine a change of a pre-calculated valve activity and to report this change to a master computer. This embodiment has the advantage that also further possibility can be taken into account in order to favorably influence the charging process so that the energy stores are as gentle as possible can be loaded. For example, the vehicle speed can be reduced, thereby reducing the valve activity, which in turn gives more time for charging.

In a further embodiment, the control unit is adapted to a pressure of the

Adjust spray and adjust a defined target output of spray by reducing expected valve activity of the plurality of valve assemblies and makes a pressure adjustment.

In this embodiment, the control unit thus matches the target discharge quantity via a

Pressure adjustment of the spray, so that a valve activity can be reduced. This has the advantage that due to the reduced valve activity more time is available for charging the energy storage, which can be charged more gently.

It is understood that the above and the still to

explanatory features are usable not only in the combination given, but also in other combinations or alone, without departing from the scope of the present invention.

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. Show it:

1 is a rear view of a schematic representation of a spraying machine,

2 is a perspective view of a first and a second preferred embodiment of the new valve assembly,

3, the first embodiment of FIG. 2 in a side view,

4 is a cross-sectional view through the embodiment of FIG. 3, 3 is a perspective view of a first housing part of the new valve assembly, the housing part of FIG. 5 in a side view,

7 shows a cross section through the housing part of Fig. 6,

8 is an equivalent circuit diagram of a preferred embodiment of a control and evaluation unit and charging circuit,

9 shows an equivalent circuit diagram of a further preferred embodiment of a control and evaluation unit and charging circuit,

10 is an equivalent circuit diagram of a further preferred embodiment of a control and evaluation unit and charging circuit, and one of a preferred embodiment of the new control unit.

Fig. 1 shows an agricultural spraying machine, which is designated in its entirety by the reference numeral 10. The spraying machine here is an agricultural machine 12 in the form of a tractor, to which a boom 14 is attached. The boom has five sections 16. These can be pivoted to each other to fold the boom 14 for transport. On the boom, a tank 18 is arranged, which contains a spray 20. Along the entire arm 14 spray nozzles 22 are distributed. The spray nozzles 22 are connected via tubing or pipes to the tank 18, so that the spray agent 20 can be conveyed to the spray nozzles. The hose or pipes are not shown for reasons of clarity. The spray nozzles 22 serve to deliver the spray agent 20 as a spray jet 24 on the floor 26. By a plurality of valve assembly according to the invention, the spray nozzles 22 can be controlled individually. As shown by way of example in FIG. 1, only the respective outer six spray nozzles 22 are in operation. Thus, only bottom portions 28 and 28 'are sprayed with the spray 20. Due to the ability to individually control each spray nozzle, the bottom 26 can be sprayed particularly precisely with the respectively necessary amount of spray 20. In particularly preferred embodiments, the agricultural machine 12 is equipped with a GPS receiver and an on-board computer (control computer). The GPS receiver and the on-board computer track the movements of the spraying machine 10 and store the already spattered ground areas. If the boom 14 swings over an already sprayed floor area 28, 28 ', then the on-board computer switches off the corresponding nozzles 22 automatically. As a result, multiple spraying of the floor regions 28, 28 'is prevented. In addition, it is possible to read in so-called field maps, by means of which it is determined which floor areas 28, 28 'are to be sprayed with which amount of spraying means. On the basis of the field map and the GPS data from the GPS receiver, a soil to be processed 26 can be sprayed purposefully.

Fig. 2 shows a perspective view of a first and a second preferred

Embodiment of the new valve assembly. The first embodiment is here indicated in its entirety by the reference numeral 30a and the second embodiment is indicated in its entirety by the reference numeral 30b. In general, the new valve assembly will be referred to below by reference numeral 30.

The valve assembly 30a according to the first embodiment comprises four

Spray nozzles via which sprays can be dispensed. The second exemplary embodiment 30b is configured to dispense spraying means via two spray nozzles 22. The valve assembly 30 is connected via a holder 32 with a spray agent supply 34. The spray agent supply 34 is here a tube through which spray agent 20 is led out of the tank to the nozzles 22. The spray agent supply 34 is designed such that a spray agent within the spray agent supply 34 can be conveyed at a constant pressure. That is, at the valve assemblies 30a, 30b, the spray agent 20 arrives at a constant pressure. The valve assembly 30 is arranged in a housing 36, which is composed of a plurality of housing parts. A first housing part 38 is connected to the spray means feed 34 via the holder 32. By the first housing part 38, the spray is conveyed from the spray agent supply 34 to the individual nozzles 22. The amount of liquid delivered to the nozzles 22 can be regulated by valves within the housing part 38.

A valve assembly 30 has at least one valve. Preferably, a separate valve is provided for each spray nozzle 22, via which a flow rate of a spray to the nozzle is regulated. The control of the individual valves is carried out via an electrically operated actuator, which can change the valve position gradually. In the first embodiment, the valve assembly 30a includes four spray nozzles 22 that can be individually controlled. In the second embodiment, the valve assembly 30b includes two spray nozzles 22 that can be individually controlled.

In both embodiments, first electric actuators 40a and 40b are arranged in a second housing part 42. The second housing part 42 is coupled to the first housing part 38, so that the first electrically operated actuators 40a, 40b can adjust the valves, in particular the valve tappets, within the first housing part 38, by the flow rate of spray through the first housing part 38 to the nozzles 22 to regulate.

In addition to the electrically operated actuators 40a, 40b, the electronics of the valve assembly are advantageously arranged in the second housing part. The electronics comprises a control and evaluation unit arranged (not shown here visible), via which the electrically operated actuators and thus the valves can be controlled, and a charging circuit for charging energy storage devices that provide energy for operating the electrically operated actuators. About a connector 44, such as a splash-proof plug, the control and evaluation unit is coupled to a central control device and supplied with energy from an electrical system of the agricultural machine. Likewise, the charging circuit is supplied via the connector 44 with energy from the electrical system. The electrically operated actuators are not operated directly by a supply voltage of the associated agricultural machine, but remove the energy for switching from an energy storage, which is arranged on the valve assembly and is charged via the charging circuit. The charging circuit and the charging process will be explained in more detail with reference to FIGS. 8 to 10.

The valve assembly 30a according to the first embodiment has, in addition to the second housing part 42, a third housing part 46, in which two further second electrically operated actuators 48a, 48b are arranged. The second electrical actuators affect the valve position of two further valves, which regulate a flow rate of spray to two other nozzles 22. It is understood that the present invention is not limited to the housing forms shown here. In particular, valve assemblies are also conceivable, which has a different number of spray nozzles, which are separately controllable via a valve. It is also conceivable that in other embodiments, multiple spray nozzles are regulated by only one valve. Likewise, it is understood that, as shown in FIG. 2, different valve assemblies are arranged on a common spray agent supply 34, which can be operated together.

3 and 4, the first embodiment according to FIG. 2 is shown in different views. 3 shows a side view of the new valve assembly 30, and FIG. 4 shows a cross-section through the valve assembly 30, as indicated by the dashed line in FIG. 3.

The holder 32 is here a joint clamp, by means of which the valve assembly to a spray agent supply 34 (not shown here) can be attached. On the valve group side facing the holder 32, an opening 50 is provided, via which the spray can flow from the spray agent supply into the first housing part 38. Within the housing part 38 is a cavity in which collects the supplied spray liquid. From the cavity, individual channels lead to separate nozzle connections 54, to which the spray nozzles (not shown here) can be fastened. Via the channels 52, the spray is controlled to the individual nozzle ports 54 promoted. Valve tappets 56 can be moved into the channels via the electric actuators 40, 48 in order to regulate a flow rate of spray agent from the cavity to the individual nozzle connections 54. In FIG. 4, for example, the valve lifter 56 is pulled out of the channel 52 by the first electric actuator 40, so that spraying means can flow unimpeded from the spray agent supply via the cavity in the first housing part 38 through the channels 52 to the nozzle connection 54. The further valve stem 56 is inserted in this embodiment by means of the second electrical actuator 48 in the channel 52, so that a spray flow from the cavity towards the nozzle port 54 is blocked. It is understood that in addition to the complete closing and the complete opening of the channel 52, it is also possible to close the channel 52 only partially so as to allow only a limited amount of spray to reach the nozzle ports 54. The electric actuators are thus preferably stepper motors, which can move the valve stem step by step.

In the preferred embodiment shown here also sensors 58 are provided on the valves, by means of which the position of the valve stem 56 of a valve can be determined. The sensors are, for example, GMR sensors or Hall sensors, the position being determined at a defined point, i. the sensor 58 is configured to provide a signal when the valve stem has exceeded a certain point.

The position determination can be used for various applications, for example as feedback for the control and evaluation unit, which controls the electric actuators 40. In one embodiment, the control and evaluation unit determines a first time at which the electrically operated actuator receives the signal for setting the valve, and a second time at which the control and evaluation unit receives the signal from the sensors 58, which indicates that the valve stem has exceeded a defined point. Subsequently, the control and evaluation compares the running time, ie the time difference between the first and the second time, with a setpoint to determine whether the valve switches properly, or if possibly the valve is clogged, so that the valve stem is not moved correctly. The position sensors can thus easily Valve of the valves are checked, reducing the reliability of the valve assembly

is advantageously increased.

FIGS. 5 to 7 show different views of a first housing part 38 of the first exemplary embodiment according to FIG. 1. Fig. 5 shows a perspective view of the first housing part 38 including the holder 32, with which the valve assembly is attached to a spray agent supply. 6 shows a corresponding side view and FIG. 7 shows a cross-sectional view of the first housing part 38.

In the exemplary embodiment illustrated here, the first housing part 38 is set up to distribute a spray agent to four spray nozzles (not shown here). For this purpose, the first housing part 38 has a cylindrical central body 60, which is coupled at its upper side with the holder 32. For example, the holder 32 has a cover part 62 which can be plugged or screwed onto the central body 60.

On the central body 60 are tangent to the surface of two valve body 64th

arranged. At each valve body 64, in turn, two cylindrical nozzle connections 54 are arranged perpendicular thereto. Overall, four spray nozzles can thus be arranged on the first housing part 38 in this embodiment.

The central body 60 is hollow and closed on the holder opposite side with a bottom plate 66. The cavity 68 within the central body 60 has an opening 50 towards the holder 32, which opens into a fitting 70 in the holder 32. About the connector 70, the valve assembly with a spray agent supply (not shown) is coupled. Pouring agent passes through the connector 70 and the opening 50 in the cavity 68. The cavity extends through channels 52 in the valve body 64. The channels 52 continue through the valve body in the nozzle ports 54. A spray can thus from the connector 70 via the Hollow body 68 through the valve body 64 into the nozzle ports 54 flow.

In the valve body 64 can from two sides valve tappets (not shown here) in the

Channels 52 are inserted. The valve lifters are adapted to the channels close, so that no spray from the hollow body 68 can flow into the respective nozzle connection 54. For each nozzle connection 54, a valve tappet is thus provided with which a flow rate of spray agent from the hollow body 68 into the respective nozzle connection 54 can be regulated. About the plunger can be a spray emission over a defined range up to the state in which no more spray is conveyed into the nozzle ports 54, regulated.

In preferred embodiments, the first housing part 38 is modular.

In particular, the valve bodies 64 are detachably arranged on the central body 60, so that they can be removed from the central body 60 and replaced by others. Preferably, the valve bodies 64 include the nozzle ports and are integrally formed. The valve bodies 64 can be placed on a coupling 72, which is formed here from a rubber ring 74. Due to the modular design 60 different valve body can be arranged on a base body. For example, a valve body with only one nozzle connection 54 can be connected to the coupling, as shown for example in the second embodiment according to FIG. The modular design leads to significant cost savings in manufacturing, since the first housing part can be used flexibly.

In addition to the couplings 72 is on the outer surface 76 of the central body 60 a

Holder provided with the energy storage 78, in particular capacitors, can be attached to the outer surface 76. About the energy storage 78, as will be explained in more detail below, the electrical actuators of the valves supplied with energy. The arrangement of the energy storage 78 on the outer surface 76 of the body has the advantage that they are continuously cooled by the spray, which is located in the hollow body 68 and conveyed. Since the spray is carried in large quantities, this usually heats up not so fast, so that even in prolonged operation, the spray cools the central body 60. By cooling the energy storage 78 whose life expectancy is significantly increased.

8 to 10 show various embodiments of the electronics for driving the valves and for charging the energy storage. Same parts will be the same Numeral referred to and explained in more detail below only in connection with an embodiment for all embodiments.

Fig. 8 shows a first embodiment of an electronics, as shown in the

Inventive valve assembly application can be found. The electronics according to this embodiment includes an active power controller.

The electronics comprise a microcontroller 80, which corresponds to a control and evaluation unit in the sense of the present invention. The microcontroller 80 may be a commercially available microcontroller, a CPU, an ASIC or similar preferably programmable controller. Via a first interface 82, the microcontroller is designed to communicate with a bus interface 84. The bus interface 84 is preferably an integrated semiconductor device that implements a commercially available bus protocol. In the embodiment shown here is a CAN bus, i. a serial bus system belonging to the group of fieldbuses. Via the bus interface 84, the microcontroller 80 sends and receives data from a higher-level control unit (not shown here). Preferably, a plurality of valve assemblies are connected to the higher-level control unit via the CAN bus in order to form together a control system of a spray device.

Via a second interface 86, the microcontroller 80 is connected to a memory 81, in particular a non-volatile electronic memory, in which a control program or data of the microcontroller 80 can be stored. The second interface 86 is preferably an I ² C interface. Further, via the second interface 86 further microcontroller can be coupled to the microcontroller 80, as will be explained in more detail below.

Via a third interface 88, the electric actuators are driven, which are indicated here in the form of two stepper motors 90. Each stepping motor 90 has its own cutting motor control unit 92 for this purpose. It is understood that in other embodiments, the stepper motor controller may also be integrated in the microcontroller 80. In addition to the control of the stepper motor controller 92, the microcontroller also receives Feedback from the stepper motor controller 92 with respect to the current position of the stepper motor 90. The stepper motors affect a valve position by moving the valve lifters back and forth as previously described, thereby regulating a flow rate through the first housing member to the nozzle ports.

In the embodiment illustrated here, two stepper motors 90 are indicated, which are controlled by the microcontroller 80. In addition, other constellations are conceivable, for example, that more than two stepper motors are controlled by a controller or that further stepper motors are controlled by a further microcontroller, which is connected to the first controller 80 via the second interface 86. In this way, different circuits can be realized with which valve assemblies can be realized with two or more valves. The further microcontroller 93 then acts preferably as a slave and is subordinate to the microcontroller 80. By a further microcontroller 93 can advantageously be used optimally, the limited space by the electronics for driving additional valves can be outsourced to one or more separate boards. Through the master / slave combination, the control of the individual valves can continue to be carried out by the central master unit, in this case by the microcontroller 80.

Moreover, via a fourth interface 94, the microcontroller 80 is connected to one or more sensors 96 that are configured to determine the current valve position by determining the position of the valve stem within the valve. The position sensors can be Hall or GMR sensors. Preferably, as shown here, a position sensor 96 is provided for each stepper motor and thus for each valve lifter. The fourth interface is preferably likewise an I ² C interface and can be combined, for example, with the second interface 86.

The bus interface 84, the position sensors 96 and the microcontroller 80 are

each coupled to an operating voltage 97. The operating voltage is provided by a first voltage regulator 98, which is coupled on the input side via a supply connection 100 to the power supply of the agricultural machine. The first voltage regulator 98 is preferably a low-drop voltage regulator, LDO, which has a small minimum difference between them. see input and output voltage generates a stable operating voltage. Typically, the voltage at the supply terminal is between 1, 5 and 13.5 volts and the regulated voltage is 3.3 volts, 5 volts or 12 volts.

The electronics further include a second voltage regulator 99. The second

Voltage regulator 99 is a DC-DC converter, in particular a boost converter whose input voltage is lower than its output voltage. In other words, the boost converter increases the applied voltage to a higher voltage.

The second voltage regulator 99 is arranged in this preferred embodiment between the energy storage 78 and the stepper motors 90 and their controls 92. The second voltage regulator 99 thus increases the voltage at which the stepper motors 90 are operated. In the present embodiment, the second voltage regulator 99 increases a voltage of 1 1, 5 to 13.5 volts, ie the voltage applied to the supply terminal 100 and to which the energy storage 78 is charged to 24 volts. Due to the higher voltage, the stepper motors 90 switch faster, whereby the switching of the valves can advantageously be accelerated. By doubling the voltage, essentially halving the switching time can be achieved.

The second essential part of the electronics of the new invention

Valve assembly forms a charging circuit 102. The charging circuit is summarized here by the dashed box.

In the exemplary embodiment according to FIG. 8, the charging circuit 102 has an active circuit

Power control 104 on. The active energy control 104 is coupled on the one hand to the supply connection 100 and on the other hand to the energy storage 78. The energy storage 78 here comprises five series-connected capacitors 106 which provide the necessary energy to operate the stepper motors 90. The active power controller 104 is preferably an integrated circuit that monitors the charging of the energy storage 78 by measuring the charge states of the individual capacitors 106 and, based thereon, adjusting the charging of the individual capacitors 106. An active power controller 104 may ensure optimal charging of the energy storage 78. In addition, the charging process can be influenced by the microcontroller 80 so as to enable a charge process that is advantageous for the system. For this purpose, the microcontroller additionally has a first and a second measuring device 108, 110, which can determine the voltage at the supply connection 100 as well as the voltage at the energy store 78 via a first and a second measuring circuit 1 12, 1 14. The measuring devices 108, 1 19 may be, for example, analog / digital converter and the measuring circuits 1 12, 1 14 simple voltage divider.

Via a further interface 1 16, the microcontroller 80 can influence the

Charge the Active Power Control 104. The microcontroller 80 is thus able to optimally control the charging process of the energy store 78.

Fig. 9 shows a second embodiment in the electronics of the new valve assembly. The exemplary embodiment substantially corresponds to the first exemplary embodiment according to FIG. 8, but here the charging circuit 102 has a passive power control 1 18. In contrast to the active energy control 104, the current limitation is expediently carried out by means of pulse width modulation (PWM), i. with the use of a field effect transistor (FET) 120 and a storage choke 122. With passive energy control 118, substantially the same beneficial effect can be achieved as with active energy control, however, the additional functions provided by the active energy control 104 integrated circuit , not available in these variants. However, the passive energy control 1 18 is much more cost-effective compared to a realization with an active energy control 102 and thus better suited for mass production.

10 shows a third embodiment of the electronics of a new valve assembly also with a passive power control 1 18. Since in the embodiment of FIG. 9, the storage inductor 122 takes up much space and an alternative embodiment with a low-drop switching regulator leads to high energy losses of the charging circuit , is in the embodiment of FIG. 10, the passive power control 1 18 realized by a so-called "single-ended primary inductance converter", SEPIC. Although a SEPIC voltage regulator also has two inductances, these are smaller than the storage inductor 122 and thus require less installation space. Implementation with a SEPIC has proven to be a preferred interim solution between simple passive power control and expensive active power control.

All charging circuits according to FIGS. 8 to 10, in interaction with the microcontroller 80 as the control and evaluation unit, can control a charging process of the energy accumulator 78 such that a charging time and a charge build-up of the energy accumulator 78 are linear relative to one another. All embodiments according to FIGS. 8 to 10 are therefore suitable for carrying out the charging process according to the invention.

Further, in all embodiments, the electronics of the valve assembly is preferably arranged on a circuit board, wherein the energy storage 78 are preferably excluded therefrom, since they are arranged for the purpose of cooling elsewhere in the valve assembly.

Advantageously, the electronics including the stepper motors are arranged in a separate second housing part of the valve assembly. This has the advantage that the electronics are protected against external influences as well as against the spray and on the other hand easy maintenance of the electronics or an exchange of these is possible.

It is understood that also a different division of electronics within the

Valve assembly is conceivable. For example, in the case of a valve assembly having more than two nozzle connections, a further electronic unit may be provided, which is arranged in a separate housing and controls the further valves for the further nozzle connections.

The further electronics can be advantageously coupled via a simple bus, such as the controller's own l ² C bus to the microcontroller 80 of the first electronics. The further electronics then acts as a slave, while the microcontroller 80 of the Master is. This makes it possible for the further electronics to access the higher-order bus via the microcontroller 80 and its CAN bus interface 84, without the need for a separate CAN bus interface for this purpose. This is sufficient for a CAN connection cable to connect the valve assembly with a higher-level control. The wiring effort can be significantly simplified. A preferred higher-level control is explained in more detail below with reference to FIG. 1 1.

Fig. 1 shows an embodiment of a control unit for controlling a

Spraying machine with a plurality of valve assemblies according to the invention. The control unit 200 is connected here via a CAN bus with the individual valve assemblies. In a preferred embodiment, additional switches 202 may be necessary to address a variety of valve assemblies. Two speeds are known on the CAN bus, CAN high speed (HS) and CAN low speed (LS). The communication at the level of the control unit and to the switches takes place in HS. The communication to the valve modules takes place in LS.

The control unit 200 is designed to control the charge states of the energy stores of the

Determine variety of valve assemblies via the CAN bus and to control a charging of the energy storage in dependence of the charge states. That is, the control unit 200 can make a prioritization of the energy storage based on the charge states and transmit this prioritization to the valve assemblies.

The valve assemblies are self-contained and can be based on the prioritization

control respective charging of their energy storage. In addition to a prioritization on the basis of the charge states, the control unit 200 can also carry out an additional prioritization on the basis of an expected valve activity. The expected valve activity can be determined and provided by a master computer 204. The determination is usually carried out using so-called field maps on which the desired amount of spray is given for each position, so that it can be derived therefrom and based on the current position, as the valves must be timed. Advantageously, the charging process of the energy store can thus be influenced by further non-physical parameters. The energy storage can be spared so further, which advantageously increases their life expectancy. The control unit 200 operates in a preferred embodiment as a CAN bus master and polls at regular intervals the valve assemblies that make up the slaves in this master-slave network. Per se, CAN is not a master-slave system, but it is advantageous if all actions are determined by a central control unit 200. In the event of an error, the control unit alone can analyze the condition of the system and take appropriate measures.

The slaves, i. the valve assemblies or their integrated control and

Evaluation units, initially remain in a waiting state. The control unit queries the slaves in the order of the node addresses stored in its directory and compares them for completeness. At a data rate of 125 kBaud, this can take up to 100 milliseconds per slave. During this time, the slaves check whether they are actually in the basic position. Thereafter, the control unit gives a certain number of slaves the permission to charge the energy storage. At the beginning of work, the energy storage devices for all valves should be 80 to 90% charged. With 60 connected valve assemblies and a permissible total charging current of 20 amps, the charging process takes 30 seconds, for example.

Under unfavorable conditions, in operation it may happen that the critical level, i. the energy state in which just the valves can be switched off safely, is achieved in individual valve assemblies. In this situation, a recommended nozzle change is dispensed with in favor of securing the failsafe circuit. The control unit recognizes this situation and gives, for example, a driving recommendation to the driver to drive more slowly. In other words, the control unit 200 is configured to use the state of charge to determine a change in a pre-calculated valve activity and to report the change to a master computer 204.

In addition, during each opening / closing operation of a valve of the

Control unit 200 transmits a position signal of the valve lifter. The control unit 200 can thus diagnose imminent blockages and / or stiffnesses by running time calculation and target / actual comparison and generate corresponding warnings. In a further preferred embodiment, the temperature of the

Energy storage and / or the temperature in the housing part in which the electronics including the stepper motors is detected. The temperature values are continuously communicated to the control unit 200, so that the control unit can take these into account.

In addition, the control unit may also be coupled to a pump regulator 206.

Via the pump regulator 206, the control unit 200 can adjust the pressure of the spray agent in the sprayer. Thus, the control unit 200 is able to set a defined target output of spraying means by reducing an expected valve activity of the plurality of valve assemblies and making a pressure adjustment. In this way, the valve activity can be reduced and a charging process can advantageously be extended or delayed altogether.

Once a valve is no longer polluted, i. E. is no longer connected to the control unit 200, the valve assembly goes into a failsafe position in which all the nozzles are closed.

In addition to an optimal control of the individual charging processes of the energy storage of the individual valve assemblies, the new control unit 200 thus enables a variety of diagnostic options. Advantageously, the control unit 200 can be realized by a microcomputer with an open software architecture, for example Linux. Alternatively, a closed software solution specially set up for the control tasks is also conceivable.

Claims

claims

Valve assembly (30) for a spraying machine (10), in particular for agricultural machines (12) or self-propelled plant protection devices, comprising a first valve, which can control a flow rate of a spraying means (20) in response to a valve position, a first electrically operated actuator (40) for Adjusting the valve position, and an energy storage (78), the electrical energy for operating the actuator (40) provides, characterized in that the valve assembly (30) further comprises a charging circuit (102) for charging the energy storage device (78) and a control and Evaluation unit (80), wherein the control and evaluation unit (80) is adapted to control a charging process of the energy storage device (78), so that a charging time and a charge structure of the energy storage device (78) are linear to each other.

Valve assembly according to claim 1, characterized in that the energy store (78) is a series circuit of a plurality of electrical capacitors (106).

Valve assembly according to one of claims 1 or 2, characterized in that the charging circuit (102) is designed to limit a charging current to the energy store (78).

4. Valve assembly according to one of claims 1 to 3, characterized in that the charging circuit (102) has an active power control (104).

5. Valve assembly according to one of claims 1 to 4, characterized in that the charging circuit (102) has a passive power control (1 18).

6. Valve assembly according to one of claims 1 to 5, characterized in that the control and evaluation unit (80) is adapted to measure and report the valve position of the first valve.

7. Valve assembly according to one of claims 1 to 6, characterized in that the control and evaluation unit (80) is adapted to determine a temperature at the energy store (78) and report.

8. Valve assembly according to one of claims 1 to 7, characterized in that the control and evaluation unit (80) is adapted to load the energy store (78) in response to an expected valve activity.

9. Valve assembly according to one of claims 1 to 8, characterized in that the valve assembly (30) further comprises a second valve and a second electrically operated actuator (48) to control the flow rate of the spray, wherein the energy storage (78) to is configured to provide energy for operating the first and the second actuator (40, 48).

10. Valve assembly according to claim 9, characterized in that the valve assembly has a second control and evaluation unit (80) for controlling the second actuator (48), wherein the second control and evaluation unit (93) of the first control and evaluation unit (80 ) is subordinate.

1 1. Valve assembly according to claim 10, characterized in that the first

Control and evaluation unit (80) has a bus interface (84) for communication with a bus, wherein the second control and evaluation unit (93) via the bus interface (84) of the first control and evaluation unit (80) on the Bus accesses.

12. Valve assembly according to one of claims 1 to 1 1, characterized in that the valve assembly comprises a housing having a first housing part and a second housing part (42) separate from the first, wherein by the first housing part, the spray means (20) bounded by the first valve is promoted and in the second housing part (42), the control and evaluation unit (80) and the first electrical actuator (40) are arranged.

13. Valve assembly according to claim 12, wherein the energy store (78) for cooling by the spray means (20) on a wall (76) of the first housing part (38) is arranged.

14. Valve assembly according to one of claims 1 to 13, characterized in that the valve assembly is used in a composite with other valve assemblies, and wherein the control and evaluation unit 80 is adapted to receive a signal having a loading priority of the valve assembly in the composite represents to load the energy store (78) in response to the signal.

A control unit (200) for controlling an injection molding machine (10) having a plurality of valve assemblies (30) according to any one of the preceding claims, wherein the control unit (200) is adapted to determine the states of charge of the energy stores (78) of the plurality of valve assemblies and to control a charging process of the energy store (78) as a function of the states of charge.

16. The control unit of claim 15, wherein the control unit is further adapted to prioritize the energy storage (78) based on the charge states and to transmit the prioritization to the valve assemblies.

17. The control unit according to claim 15, wherein the control unit is further configured to carry out a further prioritization of the energy store based on an expected valve activity.

18. Control unit according to one of claims 15 to 17, wherein the control unit is adapted to determine a change of a pre-calculated valve activity based on the charge states and to report the change to a host computer (204).

19. The control unit according to claim 15, wherein the control unit is configured to adjust a pressure of the spray means and to set a defined desired output of spraying means by reducing an expected valve activity of the plurality of valve assemblies and a Pressure adjustment makes.

20. A method for operating an injection molding machine (10) having a plurality of valve assemblies (30) each having a first valve which can control a flow rate of a spray in response to a valve position, a first electrically operated actuator for adjusting the valve position and an energy store, which provides electrical energy for operating the actuator, comprising the steps of:

Providing a control unit (200) for controlling the plurality of valve assemblies,

Determining the states of charge of the energy stores (78) of the plurality of valve assemblies,

Controlling a charging of the energy storage (78) in dependence of the charge states.

21. A computer program comprising instructions that, when executed by the computer by the program, cause it to perform the steps of the method of claim 20.