GB2196878A

GB2196878A - Spraying machine

Info

Publication number: GB2196878A
Application number: GB08722302A
Authority: GB
Inventors: Laszlo Ladanyi; Ferenc Tundik
Original assignee: DEBRECENI MEZOEGAZDASAGI; Debreceni Mezogazdasagi Gepgyarto Vallalat
Current assignee: DEBRECENI MEZOEGAZDASAGI; Debreceni Mezogazdasagi Gepgyarto Vallalat
Priority date: 1986-11-06
Filing date: 1987-09-22
Publication date: 1988-05-11
Also published as: DE3710830A1; DE3710830C2; FR2606299B1; GB8722302D0; NL8700856A; IT8720717A0; HUT47365A; FR2606299A1; SU1574160A3; DD255483A5; HU198116B; IT1204664B

Description

1 GB2196878A 1 SPECIFICATION i Spraying machine mainly for dispersion of

spray-solution proportionate to the area The invention relates to a spraying machine used mainly for the dispersion of spray-solution proportionate to the area, and in large scale plant protection.

It is well known by experts that the expensive and selective pesticides involve serious economic loss, if dispersion of the spray-solution is higher or lower than required.

Since spraying at constant rate is generally not realizable with the presently available spraying machines, the manufacturers of the plant-protective machines try to realize spraying proportionate to the area.

In the Hungarian and French patent specifi- cations No. 184 335 and 7 925 546 respectively, such spraying machine is described, where with the aid of different peripheries, microprocessing computer senses the speed, pressure and flow rate, and on the basis of the earlier entered reference data, it controls the pressure control valve of the cycle of spray-solution. Essentially similar is the spraying machine known as "DICKEY-john DjSC1000" in the trade.

Although these solutions may offer other services too, their operation requires professional skill to be required only in a special service, furthermore they are too expensive, consequently there is very little hope for their general use.

Concerning the technical standard, the French spraying machine known as "EVRARD" in the trade, stands closer to the agriculture. Here a pump with forced flow rate is driven by impeller, and the amount of liquid is distributed by a control device partly to the liquid cycle going to the sprayer mechanism and partly to a recirculated bypass cycle, through which the unnecessary spray-solution is returned to the tank. Its shortcoming is that the power obtained from the impeller is restricted, consequently this solution is applicable only in case of narrow dispersion limits. Furthermore, complicated control device is re- quired for setting accurately the trackproportionate amount of liquid delivered by the pump dimensioned for maximum amount of liquid. Such adjustment naturally may take place during run.

The common shortcoming of above solu- tions is, that the installation of an additional pump, usually centrifuge pump is required, which further increases the cost. Furthermore, by changing the quantity of dispersion, the operating pressure will inevitably vary in the cycle of the spray-solution, consequently the atornization characteristics of the spray heads will be different, which is undesirable.

The spraying machine known by the name of "CONDURIA GDE" in the trade is made in 130 piston.

West Germany, where the liquid chemicals are added to the water cycle under constant pressure. The feeding takes place with pump of forced flow rate.

70. Further shortcomings of the above described spraying machines is that in case of using sectioning switches, it is necessary to ensure the same parameters of the spraying machine when the operational width is changed. This however results in further complications and higher cost of the equipment.

The present invention is aimed at the elimination of above shortcomings, that is the realization of such improved spraying machine, whereby dispersion of the spray-solution proportionate to the area is reliably ensured at relatively low cost and with simple construction.

The invention is based on the recognition, that the problem can be solved if speed-proportionate pressure signals or pressure function is produced for dispersion of spray-solution proportionate to the area, or irrespective of other parameters, these are transferred to the cycle of the spray-solution.

In order to solve the problem, such spraying machine was used as the starting point, which is provided with a spray-solution cycle consisting of tank, sprayer mechanism, further- more pump and pressure control valve built into the interconnecting line, furthermore with speed signal transmitter and control unit in control connection with the pressure control valve.

This was developed according to the further feature of the invention, so that the speed signal transmitter is formed as signal-propor tionate pressure signal-producing unit, and the control unit is formed as pressure duplicator capable to transfer the pressure signals of the pressure signal-producing unit to the cycle of the spray-solution.

Very simple is the construction, where the speed-proportionate pressure signal-producing unit is formed as such additional liquid cycle, into which a pump positively coupled with the impeller of the spraying machine, or its transport vehicle, and an adjustable choke are built in, furthermore the control line is connected with the pressure duplicator.

It is advantageous, if an oil tank is built into the liquid cycle of the pressure signal-produc ing unit, and the liquid cycle functions with oil, or with the spray solution, or any other liquid.

According to a further feature of the inven tion, the pressure duplicator is provided with a piston axially displaceable in the house, the sides of which are connected with closed spaces, where one of the spaces is connected with the control line of the pressure signalproducing unit, and the other space with the pressure line of the spray solution. Furthermore, the pressure duplicator is provided with a pressure control unit in co-action with the 2 GB2196878A 2 In given case the pressure duplicator is provided on its control side with manually adjustable spring-actuated load transmitter, the spring cup of which is supported by the side of the piston through the axially displaceable pressure summator. It is preferable if both sides of the piston sit on the elastic sealing membrane, the flange of which is arranged in the grooves of the house. This way the differ- ent medium spaces can be simply separated from each other.

The control unit extends into the lateral Ushaped recess of the pressure duplicator's piston, and it is formed as a double seat ball valve, where the control rod arranged in the direction of the piston movement rests on the ball. Furthermore, the supply line of the con trol medium is connected to the input stub, while the control line to the controlled stub.

If besides dispersion proportionate to the 85 area constant dispersion pressure is re quired, it is advisable to provide the spraying machine with additional fresh water cycle, comprising a pump, a pressure control unit and a water tank. The pressure line is connected to a further pressure summator of the pressure duplicator. Preferably adjustable choke is built into the pressure line of the spray-solution.

The invention is described in detail with the aid of the enclosed drawing, showing two em bodiments of the spraying machine according to the invention, by way of example, in which:

Figure 1: Schematic circuit diagram of the first embodiment of the spraying machine ac- 100 cording to the invention given by way of example,

Figure 2: Longitudinal section of the control unit, shown in Fig. 1, Figure 3: Sectional view of the detail shown 105 in Fig. 2, Figure 4: Schematic circuit diagram of the other embodiment of the spraying machine ac cording to the invention, given by way of example,

Figure 5: Sectional view of the control unit shown in Fig. 4.

As shown in Fig. 1, the spraying machine according to the invention has a spray-solution cycle consisting of a conventional pump 1, a pressure control valve 2, and a spray-solution tank 3, connected through a pressure line 4 with a sprayer frame 5. Furthermore, the spraying machine is provided with a speed signal transmitter connected with a control unit 7 controlling the pressure control valve 2 of the spray-solution cycle.

According to the invention, the speed signal transmitter is formed as speed-proportionate pressure signal-producing unit 6. In the case of the embodiment shown in Fig. 1, the space-proportionate pressure signal producing unit 6 is formed as an additional and recirculating liquid cycle, which is provided with a pump 9 positively coupled with a non-driven impeller 8 of the spraying machine, an adjust able choke 10 and a separate tank 11 in the present case, e.g. for oil, while its control line 12 is connected to the control unit 7.

The path- and speed-proportionate flow rate delivered by the pump 9 partly returns into the tank 11, on the other hand the control unit 7 receives speed-proportionate pressure signals, i.e. pressure function as control signal through the control line 12.

The control unit 7 is shown in detail in Fig. 2 and 3, which according to the invention is formed as pressure duplicator transferring the pressure signals of the speed-proportionate pressure signal producing unit 6 to the spraysolution cycle. In the present case the control unit 7 is provided with a piston 14 axially displaceable in house 13, the two sides of which are interconnected with an upper space 15 and a lower space 16. The upper space 15 is connected with the control line 12 of the speed-proportionate pressure signal producing unit 6, and the lower space 16 with a pressure-signal transmitter line 17 adjoining the pressure line 4 of the spray-solution. A conventional medium- separator membrane 18 is built into the line 17 (Fig. 1).

In Fig. 2 both sides of the piston 14 rest as packing on an elastic membrane 19, which may be a rubber membrane. Their flange is arrange in grooves 20 of the house 13.

The lower plate 22 of a load summator 21 rests on the upper side of piston 14 through membrane 19, which plate 22 is arranged in the upper space 15. The load summator 21 is provided with an upper plate 24 fixed through a control rod 23 to the lower plate 22, and a manual load transmitter 25 is supported by the upper plate 24. The control rod 23 passes in an opening 26 of the house 13, and it is sealed with a packing ring 27.

The manual load transmitter 25 has several functions, e.g. setting differential pressures in the stationary position of the spraying machine for the purpose of measuring, or setting the pressure for spraying under constant pressure. In the present case the manual load transmitter 25 has a spring cup 28 with a spring 29 on it, which loads the upper plate 24 of the load summator 2 1. This is prestressed with an axially driven plate 32 in threaded connection with a shaft 31 of a hand wheel 30. For relieving the compression spring 29, the spring cup 28 can be lifted off the ring 24, e.g. by turning eccentric pins 33 embedded in house 13 while pressing down an arm 34. This way the manual load transmitter 25 can be dispensed with.

As shown in Fig. 2, the piston 14 is provided with a lateral U-shaped recess 35. A regulator unit 37 arranged in the opening 36 of the house 13 extends into this recess 35, which actually controls the pressure control valve 2.

The sectional view of the regulator unit 37 3 GB2196878A 3 given by way of example is shown in Fig. 3. Here the regulator unit 37 has a house 38 in which a double seat ball valve is arranged. The ball is marked with reference number 39, the upper and lower tapered seats with 40 and 41, furthermore a space below the lower seat 41 is marked with 42. A centrally arranged vertical control rod 43 rests on the ball 39. In the present case, the upper seat 40 is formed on the lower front part of a nut 44, the external thread of which is engaged with a threaded hole of the house 38. The relative positions of the upper seat 40 is adjustable by screwing in or out the nut 44. The adjusted position of the nut 44 is fixed by a retaining nut 45.

The nut 44 is provided with a central hole 46, the diameter of which is selected as to form an annular space 47 around the external mantle of the control rod 43, which is in communication with the vicinity of the upper seat 40.

An inlet 48 of the actuating medium leads into the space 42, which in this case is con- nected through a line 49 with the source of compressed air. An outlet 50 of the regulator unit 37 is connected through a line 51 with the pressure control valve 2 of the spray-solution (Fig. 1).

As shown in Fig. 2, the upper free end of the control rod 43 is in coaction with the upper horizontal surface of the U-shaped recess 35 of piston 14. Thus upon the down movement of the piston 14, the control rod 43 drives the bail 39 downwards and presses it to the lower seat 41. This way it blocks the path of the incoming compressed air, while the pressure prevailing in the line 51 can be released through the annular space 47, since the upper seat 40 is open.

During actuation of the spraying machine according to the invention, shown in Fig. 1-3, the pressure function developing in the control line 12 by the liquid cycle forced circulated with the impeller 8 driven pump 9, is transferred to the pressure control valve 2 of the spray solution by the control unit 7 formed as pressure duplicator. This way with relatively simple means, an always speed- proportionate, or area-proportionate dispersion of the spray solution is accomplished.

If the operating pressure were lower than the originally specified pressure value, then the pressure drops in the line 17, and conse- quently in the lower space 16 of the pressure duplicator control unit 7. As a result of this, the sum of the pressure originally set on the manual load transmitter 25 and the pressure applied through the control line 12 to the load summator 21 move the piston 14 downwards. In this case the regulator unit 37 functions as described earlier, i.e. the ball 39 closes the lower seat 41 and the air under pressure in the line 51 is vented through the outlet 50 and the annular space 47.

Since the pressure control valve 2 of the spray solution receives lower pressure through the control line 51, the pressure in the pressure line 4 is increased by the pressure con- trol valve 2. It is to be noted that in the present case the pressure control valve -2 is a magnetically controlled valve, which upon lower control pressure provides higher pres sure of the spray-solution.

If the operating pressure is higher than the originally specified value, the piston 14 moves up, while the control rod 43 releases the ball 39. Thus the ball 39 is pressed to the upper seat 40 by the compressed air entering through the inlet 48, whereby the path is free for the compressed air through the outlet 50. Since the control pressure in the line 51 rises, the pressure control valve 2 will function in the cycle of the spray solution according to the pressure drop.

It is to be noted, that in given case a positively controlled valve can also be used for the pressure control valve 2, or the existing valve turned even at 180 can be installed into the house 13.

Although the sprayer frame 5 is drawn in outline only in Fig. 1, but the sprayer frame in the spraying machine according to the invention can be closed even in each section with- out charging the pressure prevailing in the pressure line 4. This is an important advantage of the solution according to the invention. Such construction is also possible where the speed-proportionate pressure signal pro- ducing unit 6 has no separate tank 11 for the oil, but without additional tank this liquid cycle too is connected with the tank 3 of the spraysolution. Moreover, in given case any other known apparatus suitable for producing speed- proportionate pressure function may be considered as speed-proportionate pressure signalproducing unit 6.

Another embodiment according to the invention, given by way of example is shown in Fig. 4 and 5. The use of this is advisable, if - besides the speed- proportionate or areaproportionate dispersion - the dispersion under constant presure is an important aspect.

The construction in Fig. 4 differs from the one shown in Fig. 1, in that here actually the stock solution and the chemicals are stored in the tank 3 of the spray-solution. The constant operating pressure required for the spray heads of the sprayer frame 5 is provided by a separate fresh- water cycle consisting of a tank 52, a pump 53 and a pressure control valve 54.

Setting the operating pressure of the sprayer frame 5 in this case takes place in fresh water cycle, essentially independent from the rate of progress of the spraying machine. A pressure line of the fresh water cycle is marked with reference number 55, connected with the stock solution-carrying pressure line 4, into which a choke 56 is built before the junction. This adjustable choke 56 produces pressure drop.

Thus the cycle of chemicals supplies the pressurized liquid cycle. Its existing pressure is transmitted through a further diaphragm type medium separator 57 by a pressure signal transmitting line 58 to the control unit 7 formed as pressure duplicator.

Fig. 5 clearly shows that the control unit 7 differs from the one in Fig. 2, in that a further 75 load summator 59 is built in between the load summator 21 and the spring cup 28 through an elastic membrane 60. Concerning the con struction of the load summator 59, it is the same as the load summator 21. Its lower plate 61 is arranged in a space 62 into which line 58 is led.

Upon actuation of the solution according to Fig. 4 and 5, partly the speed-proportionate pressure and partly the pressure of the fresh water branch are jointly applied through line 58 to the controlled side of the control unit 7.

This way feeding of the chemicals is indepen dent from the existing pressure of the fresh water cycle.

An important advantage of this construction is, that the dispersion pressure at the sprayer frame 5 is always constant, which results in drop forming of constant quality with the spray heads, which entails considerable yield in the cultivation.

Finally it is to be noted that the mechanical pressure signal producing unit 6 proved to be very favourable in the experiments for quadra tic, i.e. parabolic pressure function. Naturally 100 according to the existing requirements, any other pressure function can be used. Further more the choke 56 is not necessarily a choke valve, it can be replaced with a suitably se lected nozzle or series of nozzle.

Returning to the construction according to Fig. 4, here a choke 10 is used for the accu rate adjustment of the dispersion. This is best accomplished with a double adjustment facil ity. One of them is used for adjusting the 110 nominal value, and with the other one the quantity of dispersed spraysolution can be reduced or increased even during run. This is desirable when various plants are cultivated in the same plot, or in the case of varying soil conditions.

Further advantage of the invention is that as a result of its relatively simple construction, it is substantially cheaper and safer than the known solution, it can be repaired and serviced in agricultural workshops, while its handling does not require any special skill.

Significant advantage of the solution according to the invention is that in stationary posi- tion of the equipment, the pressure can be adjusted with a hand wheel 30, e.g. according to a table or measurements. The value of the pressure can be set with the choke 10 in disengaged state of the sprayer frame 5 at the required rate of progress, and thereby the 130 GB2196878A 4 equipment is ready for dispersion. The adjustment is possible even on public road, when there is no loss of chemicals.

Reference numbers in the appended claims have been used to aid comprehension but are not intended to have any scope-limiting effect whatsoever.

Claims

1. Spraying machine mainly for dispersion of spraying-solution proportionate to the area, comprising a spray solution circuit consisting of a tank, a spraying mechanism, a pump built into their interconnecting line and a pressure control valve, furthermore a speed signal transmitter and a control unit in controlling connection with the pressure control valve, in which the speed signal transmitter is formed as a speed-proportionate pressure signal-pro- ducing unit (6), while the control unit (7) is formed as a pressure duplicator capable of transferring the speed-proportionate pressure signals of the pressure signal-producing unit (6) to the circuit of the spray solution.

2. Spraying machine as claimed in claim 1, wherein the pressure signalproducing unit (6) is formed as an additonal liquid circuit into which a pump (9) positively coupled with the impeller (8) of the spraying machine and pre- ferably an adjustable choke (10) are built, furthermore its control line (12) is connected with a pressure duplicating control unit (7).

3. Spraying machine as claimed in claim 2, wherein the additional liquid circuit of the pressure signal-producing unit (6) is provided with a tank (11) suitable for receiving the forced circulation control liquid.

4. Spraying machine as claimed in any of claims 1-3, wherein the pressure duplicating control unit (7) has a piston (14) axially displaceable in a house (13), its sides are connected with closed spaces (15, 16), where the one space (15) is connected with the control line (12) of the pressure signal producing unit (6), while the other space (16) with the pressure line (4) of the spray-solution circuit through a pressure signal transmitting line (17), furthermore the control unit (7) is provided with a regulator unit (37) in regulating connection with the pressure control valve (2) of the spray-solution circuit.

5. Spraying machine as claimed in claim 4, wherein the control side of the pressure duplicating control unit (7) is provided with manu- ally adjustable spring-actuated load transmitter (25) with a spring cup (28) of which rests on the side of piston (14) through a load summer (21) axially displaceable in the space (15).

6. Spraying machine as claimed in claim 4, or 5, wherein both sides of the piston (14) sit on an elastic and sealing membrane (19), the flange of which is arranged in grooves (20) of the house (13).

7. Spraying machine as claimed in any of claims 4-6, wherein the regulator unit (37) of GB2196878A 5 the control unit (7) is arranged in an opening (36) of the house (13) and extends into a lateral U-shaped recess (35) of the piston (14), furthermore it is formed as ball valve provided with two seats (40, 41), where a control rod (43) arranged in the direction of movement of the piston (14) and its free end co-acting with the end face of the piston's recess (35) rests on the ball (39), furthermore one seat (41) is connected with the line (49) of the control medium, while the other seat (40) communicates as a blow-off duct preferably with an annular space (47), furthermore the space of the regulator unit (37) receiving the ball (39) is provided with an outlet (50) as a further duct, connected to the control line (51) adjoining the pressure control valve (2).

8. Spraying machine as claimed in claim 7, wherein the distance between the two tapered seats (40, 41) of the regulator unit (37) is adjustable by a nut (44) in threaded connection with the house (38).

9. Spraying machine as claimed in any of claims 1-8, wherein it has an additional fresh water circuit consisting of a tank (52), a pump (53) and a pressure control valve (54), the pressure line (55) of which is connected with the sprayer frame (5), furthermore the pressure line (4) of the liquid cycle of tank (3) receiving the stock solution is connected through a preferably adjustable choke (56) with this pressure line (55), furthermore the fresh water circuit is connected preferably through medium separator (57) and pressure signal transmitting line (58) with a further load summer (59) of the control unit (7).

10. Spraying machine as claimed in claim 9, wherein another load summer (59) of the pressure duplicating control unit (7) is ar- ranged between the first load summer (2 1) and the manual load transmitter (25), and an elastic sealing membrane (60) is built between the adjacent plates of the load summers (2 1, 59).

11. A spraying machine substantially as herein described with reference to and as shown in Figs. 1-3 or Figs. 4 and 5 of the accompanying drawings.

Published 1988 at The Patent Office, State House, 66/71 High Holborn, London WC 1 R 4TP. Further copies may be obtained from The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Burgess & Son (Abingdon) Ltd. Con. 1/87.