DK3085229T3 - Fremgangsmåde til styring af en spredemaskines væskekredsløb - Google Patents

Description

Control method for a fluid circuit of a distributing machine Description [0001] The present invention relates to a liquid circuit of a distributing machine and a method for controlling the same.

Distributing machines, field sprayers, generally have a discharging unit, in particular a nozzle, for discharging as well as a storage container for storing the material to be discharged. In order to ensure an optimal mixing of the material to be discharged, in particular the spray medium, it has proved successful to permanently mix the material to be discharged, in particular spray medium, during the discharging process. For this purpose an agitator is located in the storage container.

Such a configuration is disclosed for example by the document DE 10 2004 040 807 Al. This discloses the liquid circuit of a field sprayer with the nozzles of a spray linkage, a storage container, a pump, an agitator and other components. For this purpose a fixed part of the pumping power is used for mixing the spray solution located in the storage container. A disadvantage is that the system permanently circulates the material to be discharged in the agitator by means of the agitator with constant power. EP 2 153 710 A2 discloses a liquid circuit which already offers the possibility of adapting the agitator power.

It is therefore the object of the present invention to provide a liquid circuit which performs an agitating process of the material located in the storage container in an optimized manner.

It is provided that the discharge rate and/or the agitating operation is adjusted by means of the valve positions of the regulating valves which control the liquid circuit on the basis of the data of at least two measuring devices. Thus, an optimized operation of the agitator can be performed by means of the at least two regulating valves. In an advantageous configuration the part of the pumping power which is not required for discharging the material is now used for circulating and/or agitating the material in the storage container. Thus, the agitating process can always be carried out with maximum possible power.

[0002] In an advantageous further development the filling level of the storage container is determined by means of a third measuring device and the measured values of this filling level sensor are taken into account by the electronic control unit when regulating the discharging process and/or agitating operation.

[0003] In a possible further development the pumping power and/or rotational speed of the pump of the field spray is additionally recorded by means of a fourth measuring device and this is taken into account when regulating the agitating operation and/or discharging process. Thus, if for example lower agitating powers are required, an adjustment of the pumping power can advantageously be made.

[0004] In an advantageous further development, at least a fifth measuring device, preferably a pressure measuring device and/or flow meter and/or position feedback of at least the regulating valve, is attached in the line to the agitator, in particular in the line section between the second regulating valve and the agitator and the corresponding measured values are taken into account by the electronic control unit when setting the regulating valves. In this way, an even more accurate characterization and control of the liquid circuit is possible.

[0005] The formulated object is solved by the regulating method of the liquid circuit according to the characterizing part of the process Claim 1, wherein the discharge rate and/or the agitating operation are/is adjusted by means of the valve positions on the basis of the data from the at least two measuring devices in such a manner that that part of the pumping power which is not required for discharging the material serves for circulating and/or agitating the material in the storage container. It is provided as standard during the distributing process that at least a small buffer flow, preferably approximately 10% of the pumping power, is conducted via the second regulating valve and the remaining part of the pumping power that is not required for discharging the material serves for circulating and/or agitating the material in the storage container. In cases of fluctuations of the discharge rate, for example, as a result of speed variations of the discharging device, this serves to effect a rapid adjustment of the material to be conveyed to the at least one nozzle. A first regulating valve controls the portion of the conveyed material which is conducted to the agitator. Compared with the prior art, this arrangement always enables the largest possible portion of the available pump power to be used for operation of the agitator.

[0006] In an advantageous embodiment when the distributing process is switched off, preferably during transport journeys or during turning in the headland, a large part, preferably at least approximately 90%, of the pumping power is used for circulating the material in the storage container. By this means the pumping power becoming free is used in an optimized manner for an increased circulation of the material located in the storage container.

[0007] In a further development of the present invention, a further measuring device serves for determining the filling level of the material in the storage container, and, on the basis of the data of said measuring device, the power of the agitator is reduced as the level decreases, by increasing the pumping power of the pump and/or increasing the portion of the material which is conducted via the second regulating valve. In this way, for example in the case of foaming spray media, an increased formation of foam can be prevented when the liquid level decreases and the agitating power of the agitator remains the same.

[0008] In an advantageous further development the rotational speed of the pump and/or the pumping power of the field spray pump is determined by means of a further measuring device and, on the basis of the data from said measuring device, the power of the agitator is reduced as the level decreases by the pumping power of the pump being reduced and/or the portion of the material which is conducted via the second regulating valve being increased. By this means the power of the spray pump can be adapted to the respective requirements in an advantageous manner.

[0009] Further details of the invention can be deduced from the description of the examples and the drawing. In the figures

Fig. 1 shows the liquid circuit according to the invention.

[0010] Figure 1 shows a liquid circuit of an agricultural field sprayer. The material to be conveyed reaches the pump 1 from the storage container 22 via the suction tap 2 and the filter 4. From there the material to be discharged passes through the second branch 5 via the pressure tap 3 before it reaches the discharging nozzle or discharging nozzles 9 via the filter 8 and the measuring device SI. From the second branch a second path leads to the regulating valve 6 which has a position feedback. The output of the regulating valve opens into the filter 4 and thus the line between the storage container and the pump. The pressure filter 8 forms a first branch of which the first path, as described, leads in the direction of the discharging nozzles 9 whilst the second path leads to the regulating valve 7 which is preferably configured as a variable diaphragm. The output of the regulating valve opens into the agitator 10. In order to record the volumetric flows to the nozzles and/or the agitator, measuring devices SI and/or S2, preferably flow sensors and/or pressure sensors and/or position feedback devices of the regulating valves, can be attached in the corresponding supply lines.

[0011] In the present example, the flow meter SI for determining the discharged amount is located in the line to the discharge nozzles. A further sensor S2, here configured for example as pressure sensor is used to determine the volumetric flow to the agitator 10. Furthermore, the regulating valve 6 has a position feedback. The sensor signals of the pressure sensors and/or the flow meter and/or the position feedback are transmitted to the job computer 21.

[0012] The job computer 21 controls the individual components of the liquid circuit. For example, this can comprise the flushing process and the discharging process. During the discharge of the material, the job computer can preferably control the discharge rate and the opening of the various partial widths according to the deposited application cards.

[0013] For optimized control of the liquid circuit, the job computer 21 regulates in a manner according to the invention the degree of opening of the valves 6 and 7 according to the required desired discharge quantity. Furthermore, a power regulation of the pump 1 can also be achieved by means of the job computer 21.

[0014] Specifically the two regulating valves are triggered in such a manner that firstly the desired discharge quantity is distributed by means of the discharge nozzles. Secondly a small portion of the available volumetric flow is fed back as reserve via the regulating valve 6 into the line between the storage container 22 and the pump 1. This enables smaller fluctuations of the required discharge rate, for example as a result of speed variations which can be detected by means of a speed sensor not shown here, to be taken into account promptly. The remainder of the available pumping power is advantageously supplied via the pressure filter 8 to the agitator 10.

[0015] The position feedback of the regulating valve 6 which responds more rapidly compared to the regulating valve 7 configured as a diaphragm enables the job computer 21 to estimate the ratio of the volumetric flows through the valves 6 and 7 and additionally determine whether the position of the regulating valve 6 is sufficient for compensating for fluctuations of the discharge rate. For this purpose the regulating valve 6 should preferably have at least one degree of opening of 10% during the discharge process.

[0016] In the case of closed partial widths, for example during travel in the headland, a very much larger quantity of the material to be discharged is automatically conducted to the agitator and thus a very much higher agitator power is achieved.

[0017] In the present example, a further sensor S3 is located in the storage container 22, which detects the filling level of the material in the discharging container 22. The measurement signal of this sensor S3 is also notified to the job computer 21.

This makes it possible in an advantageous manner, for example, for foaming spray media, to reduce the agitating power of the agitator 10 as the filling level of the storage container 22 decreases. This can be achieved by means of a reduction in the pumping power and/or by an opening of the regulating valve 6 and closing of the valve 7 as the liquid level decreases. The latter has the effect that for the same pumping power a larger portion of the conveyed material is returned via the regulating valve 6 into the line between the storage container 22 and the pump 1.

[0018] The inventive idea additionally includes modifications which are obvious to the person skilled in the art and correspond to the spirit of the invention. For example, a position feedback can be attached alternatively or additionally to the valve 7. It is also feasible to implement any measuring device as a flow meter, pressure meter or position feedback of a valve located at this point. The latter can use all these devices in order to determine the flow of material which decreases at this point.

[0019] It is also possible to use the structure shown here as a liquid circuit of a field sprayer for other distributing machines. This comprises in particular pneumatic distributing machines such as fertilizer spreaders and sowing machines. For example in the case of a pneumatic fertilizer spreader, it is possible to supply a portion of the material to be distributed into the tank in such a manner that a mixed fertilizer located there is continuously mixed, for example, in order to counteract an increasing segregation, caused for example by vibrations during travel. The components listed here such as valves and flow meters only need to be adapted for this purpose in order to determine and control the similar sizes of the distribution of the granular material.

Claims (4)

1. Fremgangsmåde til styring af væskekredsløbet ved en spredemaskine med mindst - en lagerbeholder (22), navnlig en væsketank for det materiale, der skal udledes, navnlig sprøjtes, - en eller flere dyser (9) til udledning af materialet, - en omrører (10) indvendigt i lagerbeholderen (22) til omrøring og/eller cirkulering af materialet, der skal udledes, ved hjælp af indføring af selve materialet, især til mindst en dyse, - en pumpe (1) til at transportere materialet fra lagerbeholderen (22) til den mindst ene dyse (9), - et første afsnit (8) af ledningen mellem pumpen (1) og den mindst ene dyse (9), nævnte afsnit fører til omrøreren (10) of af grener en del af materialestrømmen til den mindst ene dyse (9) hen imod omrøreren (10), - et andet afsnit (5) mellem pumpen (1) og den mindst ene dyse (9), nævnte afsnit leder en del af materialestrømmen tilbage til ledningen mellem lagerbeholderen (22) og pumpen (9) eller til selve lagerbeholderen (22) eller til komponent placeret i nævnte afsnit som fortrinsvis et filter (4), - en første reguleringsventil (7) til drosling af den volumetriske strøm mellem det første afsnit (8) og omrøreren (10), - en anden reguleringsventil (6) til drosling af den volumetriske strøm mellem det andet afsnit (5) og ledningen mellem lagerbeholderen (22) og pumpen (1), - en første måleindretning (SI), især en trykmålesonde og/eller strømmåler til at måle den volumetriske strøm, som udledes direkte ved hjælp af den mindst ene dyse (9), - mindst en anden måleindretning (S2, S5), især en trykmålesonde og/eller strømmåler og/eller positions tilbagemelding af mindst en af reguleringsventilerne (6, 7) til måling af den volumetriske strøm fra det første afsnit (8) til omrøreren (10) og/eller den volumetriske strøm fra det andet afsnit (5) til ledningen mellem lagerbeholderen (22) og pumpen (1), - en elektronisk styreenhed (21) til styring af udledningsmængden og/eller omrøringsoperationen, kendetegnet ved, at udledningsmængden og/eller omrøringsoperationen er indstillet ved hjælp af ventilstillingerne på basis af data fra de mindst to måleindretninger (SI, S2, S5) på en sådan måde at en del af pumpekraften, som ikke er påkrævet for udledning af materialet, anvendes til cirkulering og/eller omrøring af materialet i lagerbeholderen (22), og ved at som standard under udledningsprocessen mindst en lille bufferstrøm - navnlig ca. 10 % af pumpekraften - foregår via den anden reguleringsventil (6), og at den tilbageværende pumpekraft, som ikke er er nødvendig til udledningen af materialet, anvendes til cirkulation og/eller omrøring af materialet i lagerbeholderen (22).

2. Fremgangsmåde ifølge krav 1, kendetegnet ved, at når udledningsprocessen er afbrudt, fortrinsvis under transportopgaver eller under svingning på forageren anvendes en stor del fortrinsvis mindst ca. 90 % af pumpekraften til at cirkulere materialet i lagerbeholderen (22).

3. Fremgangsmåde ifølge mindst krav 1 eller 2, kendetegnet ved, at en yderligere måleindretning (S3) sørger for bestemmelse af fyldningsniveauet af materialet i lagerbeholderen (22), og på basis af data fra nævnte måleindretning (S3) reduceres kraften af omrøreren (10) eftersom niveaureduktionen af den materialedel, som foregår via den anden reguleringsventil (6) forøges.

4. Fremgangsmåde ifølge ethvert af kravene 1-3, kendetegnet ved, at en yderligere måleindretning sørger for bestemmelsen af rotationshastigheden af pumpen og/eller pumpekraften af markdysepumpen og på basis af data fra nævnte måleindretning reduceres kraften af omrøreren (10) eftersom niveaureduktionen af pumpekraften af pumpen (1) reduceres og/eller materialedelen, som foregår via den anden reguleringsventil forøges.