JP4830168B2 - Electrostatic application power supply - Google Patents

Description

  The present invention relates to an electrostatic application power supply device used in an electrostatic application spray device for applying an electrostatic charge to sprayed agricultural chemicals or paints to reliably adhere these agricultural chemicals or paints to an adherend.

  2. Description of the Related Art Conventionally, a static electricity imparting type sprayer in which an electrode such as a high potential ring is disposed in front of a spray nozzle is provided. In this electrostatic application type sprayer, electric charges from the electrodes are applied to a spray liquid such as a chemical liquid sprayed from the spray nozzle and released into free space. For this reason, the adhesiveness to the agricultural crops, such as the chemical liquid atomized by the injection, becomes favorable, and the effects of pest control and sterilization are improved (for example, refer to Patent Document 1).

  By the way, since such a conventional electrostatic application type sprayer is generally used outdoors, a battery that is convenient to carry is used as a power supply for the electrostatic application, and the DC voltage of this battery is boosted to a high voltage. A method of applying continuously to the annular electrode or the like as an electrostatic application electrode in the vicinity of the spray nozzle is employed.

  In this electrostatic application sprayer, for example, as shown in FIG. 2, a voltage generated by a battery 11 such as a dry battery or a secondary battery is applied to a step-up transformer 13 via an FET 12 that is a switching element. On the other hand, an oscillation circuit 14 is provided, and the switching element 12 is switched by a switching pulse generated by the oscillation circuit 14.

  For this reason, the voltage applied to the primary side winding of the step-up transformer 13 is interrupted by the switching pulse, and a high voltage pulse is induced on the secondary winding side of the step-up transformer. The high voltage pulse is rectified by the rectifier diode 16 and then applied to the electrostatic application electrode 15 arranged in front of the spray nozzle (not shown).

Therefore, the spray particles of the chemical solution such as agricultural chemicals sprayed from the spray nozzle are given a charge from the electrostatic application electrode, and the adhesion of the chemical solution to the leaves of cultivated plants and the like is improved by the applied charge. . For this reason, the insecticidal effect or the disinfection effect with respect to the pest which adhered to this leaf is heightened.
JP 2001-300362 A

  However, in such a conventional electrostatic application type spraying device, whether or not electrostatic spraying is normally performed during the spraying operation of the chemical solution, that is, whether or not the chemical solution is evenly attached to the cultivated plant or the like It is difficult for the operator to visually confirm the above.

  On the other hand, when the battery voltage fluctuates or decreases, the charge applied to the spray particles of the chemical solution may become abnormal (insufficient), and the operator does not notice this, and the chemical solution is applied to the cultivated plants, etc. There was a problem that the spraying operation continued in a state where it did not adhere uniformly.

  The present invention has been made in view of such conventional problems, and by controlling the voltage applied to the electrostatic application electrode to a constant voltage value at which electrostatic spraying is normally performed, a chemical solution, etc. Provided is an electrostatically applied power supply device that can evenly adhere to the adherend and avoid consuming the stored charge of the battery more than necessary, thereby extending the life of the battery. For the purpose.

In order to achieve the above object, an electrostatic application power supply device according to the present invention includes a battery, an oscillation circuit that operates using the battery as a power supply and outputs a pulse voltage, and a voltage generated by the battery. A switching element that is intermittently connected with a duty ratio of a pulse voltage to be output, and a step-up transformer that is connected to the battery via the switching element and boosts a primary voltage by the intermittent and induces a high-voltage pulse voltage on the secondary side The high voltage pulse voltage is rectified and applied to the electrostatic application electrode, the electric charge is applied from the high voltage electrostatic application electrode to the spray liquid sprayed from the spray nozzle, and the spray is applied. the liquid an electrostatic applying power supply to be attached to an adherend, the voltage applied to the electrostatic applying electrodes to vary based on the variation or decrease of the voltage the battery is generated Monitoring, so as to maintain the applied voltage based on the battery the monitoring information despite variations or reduction in the voltage generated in the set value, duty ratio control circuit for controlling the duty ratio of the output pulse of the oscillation circuit It is characterized by providing.

  With this configuration, when the duty ratio adjustment circuit detects that the applied voltage of the electrostatic application electrode has decreased, the duty ratio of the pulse output from the oscillation circuit is increased, while the application of the electrostatic application electrode is increased. When it is detected that the voltage has risen, the duty ratio of the pulse output from the oscillation circuit is reduced. In this way, by controlling the period during which the switching element is turned on, the secondary voltage of the step-up transformer or the voltage applied to the electrostatic application electrode can be controlled to a designed constant value.

  As a result, the power consumption of the battery 11 is stabilized and the life of the battery 11 can be extended. Further, since the boosted secondary voltage does not become excessive, even if a part of the body touches the electrostatic application electrode, a major accident due to an electric shock can be avoided. Furthermore, the worker can carry out the spraying work with peace of mind without worrying about whether the amount of sprayed liquid adhering to the adherend is uneven or insufficient.

  In the electrostatic application power supply device according to the present invention, the duty ratio control circuit detects the voltage of the circuit connecting the primary winding of the step-up transformer and the switching element, so that the voltage applied to the electrostatic application electrode can be reduced. It is characterized by monitoring.

  With this configuration, it is possible to monitor the voltage applied to the electrostatic application electrode at a portion close to the oscillation circuit and the step-up transformer, and it is possible to realize a compact circuit including the duty ratio control circuit together with the oscillation circuit and the step-up transformer.

  The electrostatic application power supply apparatus of the present invention has a duty ratio control circuit, and causes the duty ratio control circuit to monitor the secondary side voltage of the step-up transformer, and sets the secondary side voltage based on the monitoring information to a set value. The duty ratio of the pulse output from the oscillation circuit is increased when the secondary voltage of the step-up transformer is reduced by controlling the duty ratio of the output pulse of the oscillation circuit so as to maintain the When the side voltage rises, the duty ratio of the pulse output from the oscillation circuit is reduced. Thereby, the period during which the switching element is turned on can be controlled, and the secondary voltage of the step-up transformer can be controlled to a constant value.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block connection diagram showing an electrostatic application power supply apparatus according to an embodiment of the present invention. This electrostatic application power supply device uses a dry battery or a secondary battery (hereinafter abbreviated as a battery) 11 as a power source. The generated voltage of the battery 11 is, for example, DC 6 volts.

  In addition, a switching element 12 is connected to the battery 11 through a primary winding of a step-up transformer 13.

  The switching element 12 functions to intermittently switch the voltage applied to the primary winding of the step-up transformer 13 at a predetermined duty ratio by switching the voltage generated by the battery 11. In addition, a high voltage of, for example, 15 to 20 kilovolts is induced on the secondary side of the step-up transformer 13 by the intermittent primary voltage due to the switching of the switching element 12. As the switching element 12, for example, an FET (Field Effect Transistor) is used.

  An oscillation circuit 14 is connected to the battery 11. The oscillation circuit 14 outputs a pulse signal having a frequency of 11 kHz, for example, and the duty ratio of the pulse output can be adjusted.

  Further, the switching element 12 is intermittently controlled by the duty ratio of the oscillation pulse (that is, the ratio between the time of one cycle and the time when the signal is at a high level).

  A duty ratio control circuit 16 is connected to the primary winding of the step-up transformer 13. The duty ratio control circuit 16 constantly monitors the secondary side voltage of the step-up transformer 13 or the applied voltage of an electrostatic application electrode described later, and sets the secondary side voltage or applied voltage to a predetermined value based on the monitoring information. For example, the duty ratio of the output pulse of the oscillation circuit 14 is controlled so as to be maintained at 15 to 20 kilovolts. Note that an electrostatic application electrode 15 is connected to the secondary side of the step-up transformer 13 via a rectifying diode 16.

  Next, the operation of the electrostatic application power supply device having the above-described configuration will be described with reference to the drawings.

  When spraying agricultural chemicals using the electrostatic application spraying device, first, the chemical solution is pumped from the chemical solution tank to the spray nozzle by a pump (not shown). For this reason, a high-pressure chemical solution is ejected from the spray nozzle in an atomized state.

  On the other hand, when a power switch (not shown) is turned on in parallel with the injection of the chemical solution from the injection nozzle, the power supply voltage is supplied from the battery 11 shown in FIG. 1 to the switching element 12 via the primary winding of the step-up transformer 13. Is applied.

  At the same time, the power supply voltage of the battery 11 is also applied to the oscillation circuit 14, and the oscillation circuit 14 oscillates and outputs a voltage pulse of 11 kHz, for example.

  The switching element (FET) 12 receives this voltage pulse at the gate electrode, and interrupts the voltage applied between the drain electrode and the source electrode. Since the voltage applied to the primary winding of the step-up transformer 13 is also interrupted at this frequency by this intermittent operation, a high voltage pulse of the same frequency boosted to the secondary winding of the step-up transformer 13 is induced.

  The high voltage pulse is rectified to a DC high voltage through a rectifier diode 16 (not shown) and then supplied to the electrostatic application electrode 15. For this reason, the chemical liquid ejected from the ejection nozzle is given an electric charge by the electrostatic application electrode 15 disposed in front of the ejection nozzle.

  In this way, the sprayed chemical solution to which the electric charge is applied has improved adhesion to a cultivated plant having a ground potential, for example, a leaf of an agricultural crop, and can perform extermination and sterilization of a pest attached to the leaf.

  By the way, the battery such as the dry battery or the secondary battery consumes the stored charge with time of use, and the generated voltage gradually decreases. For this reason, the voltage induced on the secondary side of the step-up transformer is also reduced, and the electrostatic energy given by the electrostatic application electrode 15 to the spray chemical injected from the injection nozzle is reduced or unstable. Thereby, the adhesion amount of the chemical | medical solution with respect to agricultural products will become uneven or inadequate.

  In general, it is difficult for an operator himself / herself to visually discriminate whether the amount of the chemical solution attached is uniform or non-uniform, or sufficient or insufficient. Therefore, the chemical solution spraying operation may be terminated because the chemical solution is overlooked to be uneven or insufficient.

  In this embodiment, the DC voltage applied to the electrostatic application electrode is monitored by the duty ratio control circuit 17 connected to the circuit connecting the primary winding of the step-up transformer and the switching element, and this monitoring information is input to the oscillation circuit 14. Then, the switching duty of the switching element is feedback controlled.

  Thereby, even when the generated voltage of the battery 11 fluctuates within the range of the set level, the DC voltage applied to the electrostatic application electrode 15 can always be kept constant. On the other hand, when the voltage generated by the battery 11 has dropped to a voltage level that is not appropriate for the electrostatic application, that is, when the voltage has dropped beyond the set level range, power supply to the step-up transformer 13 is stopped as necessary. It is desirable to do.

  For example, a voltage value (eg, 3.8 volts) immediately before the set voltage that is inappropriate for the electrostatic application due to the drooping characteristics of the battery 11 is a value that automatically turns off the power switch or pump switch of the battery 11. It is also possible to notify the operator of the stop of electrostatic spraying by turning off the lamp when the set value is reached.

  As a result, even when the generated voltage of the battery 11 has a margin (sufficiently high voltage) and when a low voltage is generated immediately before reaching the set voltage, the electrostatic application effect of the chemical solution by the electrostatic application electrode 15 is constant. It becomes.

  On the other hand, when the generated voltage of the battery 11 is lowered below the set level that is the lifetime of the battery 11, the entire electrostatic spray sprayer can be stopped.

  In addition, when the generated voltage (remaining capacity) of the battery 11 has a margin, the switching duty can be controlled to perform switching while suppressing the consumption of the battery capacity more than necessary, thereby extending the life of the battery 11. it can.

  Note that the DC voltage applied to the electrostatic application electrode 15 is monitored by the duty ratio control circuit 17 on the primary winding side of the step-up transformer 13 as shown in FIG. It is good also as an electricity provision electrode itself.

  As described above, according to the present embodiment, the DC voltage applied to the electrostatic application electrode 15 is monitored, and the applied voltage of the electrostatic application electrode 15 is maintained at the set value based on the monitoring information. By controlling the duty ratio of the output pulse of the oscillation circuit 14 by the duty ratio control circuit 17, the spray liquid from the sprayer or the like electrostatically applied by the electrostatic application electrode 15 by receiving the DC voltage is used as a cultivated plant or the like. It is possible to evenly adhere to the adherend, and it is possible to prevent the charged charge of the battery 11 from being consumed more than necessary, and as a result, the life of the battery 11 can be extended.

  The electrostatic application power supply device of the present invention can evenly attach a chemical solution or the like to an adherend, and can prevent the battery charge capacity from being consumed more than necessary, resulting in the life of the battery. It is effective for spraying pesticides and paints, etc., and by applying static electricity to sprayed pesticides and paints, it can be used in an electrostatic application spray device to ensure that these pesticides and paints adhere to adherends. It is useful for an electrostatic application power supply device and the like.

It is a block connection diagram showing an electrostatic application power supply device according to an embodiment of the present invention. It is a block connection figure which shows the conventional electrostatic provision power supply device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Battery 12 Switching element 13 Step-up transformer 14 Oscillation circuit 15 Electrostatic application electrode 16 Rectifier diode 17 Duty ratio control circuit

Claims (2)

A battery, an oscillation circuit that operates using the battery as a power source and outputs a pulse voltage, a switching element that intermittently switches a voltage generated by the battery at a duty ratio of a pulse voltage output by the oscillation circuit, and the switching element And a step-up transformer that boosts a primary voltage by intermittence and induces a high-voltage pulse voltage on the secondary side, and rectifies the high-voltage pulse voltage to apply static electricity. is applied to the electrode, to spray the liquid ejected from the ejection nozzle by applying an electric charge from the electrostatic applying electrodes of the high voltage, the spray liquid an electrostatic applying power supply to be attached to an adherend, wherein monitoring the voltage applied to the electrostatic applying electrodes to vary based on the variation or decrease in voltage battery occurs, to change or drop in voltage the battery is generated The applied voltage to maintain the set value based on the monitoring information Warazuso, electrostatic applying power supply, characterized in that it comprises a duty ratio control circuit for controlling the duty ratio of the output pulse of the oscillation circuit. 2. The duty ratio control circuit monitors the voltage applied to the electrostatic application electrode by detecting a voltage of a circuit connecting a primary winding of a step-up transformer and a switching element. Electrostatic application power supply device.

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