JPH0634669B2 - Pesticide / liquid fertilizer quantitative dilution injection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a pesticide / liquid fertilizer quantitative dilution injection device used for a machine for spraying pesticide / liquid fertilizer regardless of whether it is for traveling or stationary.

[Prior Art] In conventional pesticide / liquid fertilizer spraying, a certain amount of pesticide or liquid fertilizer is put in a tank for fresh water, and while stirring, a diluted liquid is sucked with a pump, pressurized, and sprayed.

Up to now, pesticide injection has been proportional to the pressure difference between the front and rear of the pipe, using a system that injects the drug into the discharge side of the pump using an injection pump so that it is proportional to the discharge flow rate of the pump, and a venturi tube is used on the discharge side. There were many ways to inject the liquid medicine.

[Problems to be Solved by the Invention] However, in the method of injecting the chemical liquid into the discharge side of the pump, the working pressure of the nozzle is often limited by the discharge pressure of the injection pump, which is not suitable for high-pressure spraying. . Further, in the discharge side injection method, the residual water of the pump is consumed as wasted energy. The injection point is high pressure,
Since it has a pulsating flow, it is necessary to use an infusion pump capable of withstanding high pressure, and the infusion pump must be driven while following the pulsating flow. Therefore, the injection pump driving motor is required to have a high speed response, and the control means is required to meet the requirement. Therefore, the injection device is required to be complicated and high-grade. Further, there is a drawback that the agitation of the drug after injection is poor.

In addition, the self-control using a Venturi tube has a disadvantage that the range of the pesticide dilution ratio is narrow and the pesticide must be first diluted. The present invention aims to solve the above problems.

[Means for Solving the Problems] The present invention adopts the following configuration in order to achieve such an object. That is, the pesticide / liquid fertilizer quantitative dilution injection device according to the present invention has a nozzle and a tank for fresh water provided at the beginning of the main passage, a high-pressure pump for sucking and pressurizing fresh water, and a pressure regulating valve attached to the high-pressure pump,
A spillway for returning spilled water from the pressure regulating valve to the suction pipe of the main system, a flow rate detection means installed in the spillway, and a pesticide stock solution or liquid fertilizer stock solution in the suction pipe of the spillway or main system. A chemical liquid system path for injecting the liquid, an injection pump provided in the chemical liquid system path, and a nozzle utilization flow rate that passes through the nozzle based on the detection value by the flow rate detection means, and corresponds to the nozzle utilization flow rate. It is provided with a control means for controlling the discharge amount of the infusion pump and a motor for driving the infusion pump.

The pesticide / liquid fertilizer injection device has a small injection amount error, the medicines are sufficiently mixed up to the use nozzle, the dilution ratio can be changed in a wide range, and the use nozzle pressure must be freely selectable. Here, use a spillway that feeds back to the suction pipe of the main passage, a chemical liquid passage that intervenes an injection pump that puts pesticide / liquid fertilizer into the spillway, and control means based on the information of the flow rate detection means. With this, regardless of the working pressure of the nozzle, it is possible to automatically inject the pesticide / liquid fertilizer concentrate with a relatively high accuracy in a wide dilution ratio range.

[Operation] First, the desired pesticide / liquid fertilizer dilution ratio is input to the control means. After driving the high-pressure pump and determining the spraying pressure with the pressure regulating valve, the spraying work is started. At this time, the flow rate detecting means provided in the spillway detects the spillage flow rate and sends the signal to the control means. The dilution ratio is expressed as the ratio of the pesticide injection amount and the amount obtained by subtracting the surplus water amount from the total pump amount.Therefore, multiply the value obtained by subtracting the output of the flow rate detection device from the total pump amount to obtain the required injection amount. Then, the command voltage of the injection pump driving motor is calculated from the discharge amount per one rotation of the injection pump, and the injection pump is driven.

More specifically, the amount of water absorbed by the high-pressure pump is Q _i , the amount of residual water is Q _f , the amount of pesticide / liquid fertilizer introduced from the liquid chemical system by the injection pump is q, and the amount is sprayed through the nozzle. Assuming that the nozzle utilization flow rate is Q _o and the ratio between the nozzle utilization flow rate Q _o and the total pump flow rate Q _t in the high pressure pump is K, the block diagram of the flow rate relating to the high pressure pump is as shown in FIG. Then, as is apparent from this block diagram, Q _i + q + Q _t × (1-K) = Q _t (Equation 1) Q _o = Q _t × K (Equation 2) Q _f = Q _t × (1 -K) ... (Equation 3) holds.

A block diagram relating to the density when the target density is P is as shown in FIG. As is apparent from the block _{diagram, (q + Q f × P} ) / (Q i + q + Q f) = P ... ( Equation 4), and this equation 4 from the formula 1 to formula _{3 P = q / (Q i} + q ) = Q / Q _o (Equation 5).

Thus, the nozzle for pumping the total flow rate Q _t are those operating speeds of the high-pressure pump can be determined if determined, by detecting the remaining amount of water Q _f at a flow rate detection unit, represented by Q _t -Q _f The utilization flow rate Q _o can be calculated, and if the target concentration P is indicated, the pesticide / liquid fertilizer injection amount q can be calculated from Equation 5. The control means calculates the injection amount q of the pesticide / liquid fertilizer based on such a principle, and controls the discharge amount of the injection pump so as to obtain this injection amount q.

Therefore, according to the present invention, in the steady operation state,
Theoretically, the concentration of the spray liquid passing through the nozzle should be the target concentration P
Can be converged to.

In an actual device, since the flow of the spillway that has passed through the pressure regulating valve is a flow that blows out from the high pressure side to the suction pipe, it generally has a fluctuation component of about 1 to 2 Hz, for example. Since the amount of fluctuation is small, it is not necessary to change the driving speed of the injection pump driving motor so as to follow it. Therefore, the concentration error in the steady state is negligible even when applied to an actual device.

When the nozzle utilization flow rate is changed, the amount of residual water changes, so the control means operates to change the drive speed of the injection pump so that the concentration of the spray liquid becomes the injection amount q that can converge to the target concentration. . At this time, a transient error occurs in the concentration of the liquid remaining in the main system path, but this state is short in time and can be sufficiently ignored in the actual spraying work.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

1 is a spray nozzle, 2 is an on-off valve, 3 is a main passage, and a long high-pressure rubber hose is used in the case of conventional spraying, and steel pipes and rubber hoses are mixed in running control machines, etc. The mainstream is pipes such as vinyl chloride pipes. A high-pressure pump 4 is often used as a plunger pump. 5 is a tank for fresh water, and 6 is a suction pipe forming a part of the main passage. Reference numeral 7 is a prime mover for driving the high pressure pump, and 8 is a pressure regulating valve attached to the pump. Reference numeral 9 is a spillway from the pressure regulating valve, in which a flow rate detecting means 10 is interposed. Reference numeral 11 is a control means, which includes a microcomputer control device 12 and an amplifier 13.

Information from the flow rate detecting means 10 is input to the microcomputer controller 12. Reference numeral 14 is an injection pump driving motor, 15 is an injection pump, and 16 is a pesticide or liquid fertilizer stock solution tank.

FIG. 2 shows a flowchart of software of the microcomputer control device 12. First, in step S1, a desired set dilution ratio corresponding to the target concentration is input to the microcomputer, and in step S2, the spill flow rate is read. And step S3
If the nozzle flow rate is calculated in step S4, and if there is a main system flow rate in step S4, the speed command voltage of the motor is calculated by multiplying the flow rate used by the dilution factor in step S5, and the injection pump is calculated in step S6. To rotate. If the flow rate used is 0 in step S4, the infusion pump is stopped in step S7.

This system can change the dilution ratio of the chemical solution in a wide range, and with the main flow rate of 10 to 30 l / min, 100
The automatic injection dilution operation was carried out in the range of 2-fold to 1000-fold. The discharge pressure of the nozzle used is from 1MPa to 3.5MPa.
And the range.

It is possible to directly measure the nozzle utilization flow rate by interposing the flow rate detection means in the main system path on the high pressure side. In this case, however, the injection pump with respect to the flow rate variation has a high frequency of disturbance of the flow rate variation. Response becomes poor and the injection accuracy becomes poor.

In the case of a system configuration in which the discharge pressure of the high-pressure pump is constant and the used flow rate does not change, a flow rate switch for detecting the presence or absence of flow in the high-pressure main system path is used as the flow rate detection means. Intervene. When the utilization flow rate becomes 0, this flow rate switch is turned off and the injection pump driving motor is stopped. Further, instead of the microcomputer controller, the inside of the control means may be an electric circuit for manually setting the speed command voltage proportional to the dilution concentration before the work.

In a system where the dilution ratio is always constant, a simple method is to drive the injection pump with a constant-speed rotation motor and turn this motor on and off with the signal from the flow rate switch interposed in the high-pressure main system path. You can

[Advantages of the Invention] The pesticide / liquid fertilizer quantitative dilution injection device according to the present invention can be constructed relatively easily because the pesticide stock solution or the liquid fertilizer stock solution is injected into the suction pipe side. Also,
In this way, the pesticide and liquid fertilizer that have been injected pass through the high-pressure pump together with fresh water and spilled water, so that stirring and mixing can be performed efficiently. Moreover, since the nozzle usage flow rate is detected by detecting the amount of excess water, and the injection amount of pesticide and liquid fertilizer by the injection pump is controlled based on the result, the dilution rate is adjusted regardless of fluctuations in the nozzle usage flow rate. Instead, it can be automatically converged to a desired set value or its vicinity. In addition, by controlling the discharge rate of the injection pump, the injection rate of pesticides and liquid fertilizer can be positively changed, so compared to the case where a chemical solution is introduced by itself into the main system path using a Venturi tube, etc. Thus, the dilution rate can be appropriately selected and set from a wider range of values. That is, the target concentration of the pesticide / liquid fertilizer can be changed within a wide range. The range of dilution ratio can be changed in a wide range.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining the operation of the present invention, FIG. 2 is a block diagram for explaining the same operation, FIG. 3 is a circuit explanatory view showing an embodiment of the present invention, and FIG. It is a flowchart of software of the microcomputer control device in the embodiment. 1 ... Nozzle, 2 ... Switching valve, 3 ... Main system path (high pressure main system path), 4 ... High pressure pump, 5 ... Fresh water tank, 6 ... Main system path (suction pipe), 7 ... Engine, 8 ... Pressure regulating valve , 9 ... spillway system, 10 ... flow rate detecting means, 11 ... control means, 12 ... microcomputer control device, 13 ... amplifier, 14 ... injection pump drive motor, 15 ... injection pump, 16 ... pesticide / liquid fertilizer stock tank

Claims (1)

[Claims] 1. A nozzle attached to the end of the main passage, a tank for fresh water provided at the beginning of the main passage, a high-pressure pump for sucking and pressurizing the fresh water, and a pressure regulating valve attached to the high-pressure pump. A spillway for returning spilled water from the pressure regulating valve to the suction pipe of the main system, a flow rate detection means installed in the spillway, and a pesticide stock solution or liquid fertilizer stock solution in the suction pipe of the spillway or main system. A liquid flow path for injecting a liquid, an injection pump driven by an injection pump drive motor provided in the liquid flow path, and a nozzle utilization flow rate passing through the nozzle based on a value detected by a flow rate detection means. A pesticide / liquid fertilizer quantitative dilution injection device, comprising: a control means for controlling the discharge amount of the injection pump in accordance with the flow rate of the nozzle used.