JP2003088783A - Spray control device for boom sprayer - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To facilitate the determination of an abnormality of a flow sensor in a boom sprayer and to improve the workability of spraying a chemical solution. SOLUTION: A flow sensor 32 for detecting a flow rate, a pressure sensor for detecting a pressure, and an ejection line 27 for feeding a chemical solution supplied from a pump P via a flow rate control valve 24 to a spraying boom by opening a spraying cock C. 31 and
In the case of a boom sprayer that controls the spraying capacity by the opening degree of the flow control valve 24, when the flow detection value of the flow sensor 32 is equal to or less than a predetermined value and the pressure detection value of the pressure sensor 31 is within a predetermined range, the "flow sensor abnormality ", And the configuration of the spraying control device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray control device for a boom sprayer, which sprays a chemical (medicine solution) onto agricultural crops, soil or the like.

[0002]

2. Description of the Related Art A jet line for sending a chemical solution to a spray boom having a spray nozzle has a flow rate control valve for supplying a chemical solution from a pump, a flow rate sensor for detecting the flow rate and pressure of the chemical solution flowing through the jet line, and the like. A pressure sensor or the like is provided to control the flow rate and the pressure of the flow rate control valve to maintain the flow rate and pressure of the chemical liquid in the ejection line within a predetermined range while obtaining the chemical liquid dispersion amount and spray pressure from each spray boom. .

[0003]

Thus, in the chemical liquid spraying mode in which the chemical liquid is sprayed while the spraying volume is controlled by the flow rate and the pressure of the chemical liquid in the jet line by the flow rate control valve for adjusting the chemical liquid flow rate, the flow rate sensor and the pressure sensor are used. It may be difficult to maintain accurate spray control because the sensor may be broken. In particular, the flow rate sensor is often in a mechanical form like a turbine type flow rate sensor, and it is difficult to determine whether or not there is an abnormality in detection, and it is difficult to electrically determine without disassembling. Moreover, when there is an abnormality in this flow rate sensor, it is not possible to determine whether the spray cock is open or closed, and therefore the control of the flow rate control valve cannot be stopped or accurate control cannot be performed.
The present invention eliminates such defects, facilitates abnormality determination, and facilitates troubleshooting.

[0004]

According to the first aspect of the present invention, the flow rate of the chemical liquid supplied from the pump P through the flow rate control valve 24 to the spraying boom 27 by opening the spraying cock C is supplied to the spraying line 27. A flow rate sensor 32 for detecting
In a boom sprayer in which a pressure sensor 31 for detecting the pressure is provided and the spraying capacity is controlled by the opening degree of the flow rate control valve 24, the flow rate detection value of the flow rate sensor 32 is a predetermined value or less, and the pressure detection by the pressure sensor 31 is detected. If the value is within a predetermined range, it is determined that the flow rate sensor is abnormal, and the spraying control device is configured.

The chemical liquid in the chemical liquid tank is supplied to the spray boom side by driving the pump P. At this time, the chemical liquid supply amount supplied to the jet line 27 via the flow rate control valve 24 is
The spraying flow rate is controlled to the set flow rate by the opening of the flow rate control valve 24, and the spraying cock C is opened to send the spraying boom to the spraying boom for spraying the chemical solution.

Here, when the flow rate detection value by the flow rate sensor 32 of the jet line 27 is above a predetermined value, the flow rate sensor 32 and the flow rate detection by it can be controlled as normal, but this flow rate detection value is below a predetermined value. Moreover, when the pressure detection value by the pressure sensor 31 is within the predetermined range, the flow rate sensor 32 is determined to be abnormal, and accordingly, an alarm is issued. Since the open / close determination of the spray cock C cannot be made by the abnormality determination of the flow rate sensor 32, the flow rate control valve 2
The control of 4 is stopped.

According to a second aspect of the present invention, when the engine speed is above a predetermined value, the flow rate detection value of the flow rate sensor 32 is below a predetermined value and the pressure detection value of the pressure sensor 31 is below a predetermined value. Is characterized in that it is determined as "flow sensor abnormality". In the chemical liquid spraying control, when the engine rotates more than a predetermined value and the pump P drives to spray, the flow rate detection value by the flow rate sensor 32 is less than a predetermined value and the pressure detection value by the pressure sensor 31 is less than a predetermined value. It is determined that the flow sensor 32 is abnormal. When the engine speed is low and does not reach a predetermined value, such an abnormality determination of the flow sensor 32 is not performed.

According to the third aspect of the present invention, when the pressure in the ejection line 27 becomes equal to or higher than a predetermined value when the "flow sensor abnormality" is determined, the flow control valve 24 is operated in the closing direction by a predetermined amount. When the pressure becomes equal to or lower than a predetermined value, the pressure control is performed so that the pressure continues to be the set pressure.

This processing action is executed when the flow rate sensor 32 is determined to be abnormal in the chemical liquid spraying control, and is performed under pressure detection by the pressure sensor 31 instead of the flow rate sensor 32. In the invention according to claim 4, when the flow rate control valve 24 is operated and the pressure does not fall below a predetermined value when it is determined that the "flow rate sensor is abnormal", the flow rate is determined to be "spray cock closed". It is characterized in that the control valve 24 is operated so as to be opened.

When the pressure in the jet line 27 does not fall below a predetermined value even if the flow control valve 24 is operated to be closed, it is judged that the spray cock C is closed and the opening degree of the flow control valve 24 is opened. is there.

[0011]

According to the invention described in claim 1, the flow rate sensor 3 is provided.
The abnormality determination No. 2 is automatically and easily made by the flow rate detection value by the flow rate sensor 32 and the pressure detection value by the pressure sensor 31, and trouble handling is also easy.

According to the second aspect of the invention, the abnormality of the flow rate sensor 32 is determined when the rotation of the engine is above a predetermined value, and this determination is not performed when the rotation does not reach the predetermined value. The accuracy of the abnormality determination of the flow sensor 32 can be further improved. According to the third and fourth aspects of the invention, even if the flow rate sensor 32 fails, control processing is performed by the pressure detection of the pressure sensor 31. Therefore, the work can be continued for the time being, and even if the work is hurried, the chemical liquid is urgently needed. Can be sprayed. Since the spray amount per unit area is determined only by the pressure, approximately the same workability can be maintained without the flow rate display.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to the drawings. Regarding a boom sprayer mounted on a riding tractor vehicle body, a high-floor four-wheel drive vehicle body 9 has front wheels 11 and rear wheels 4 steered by a steering wheel 10 and is mounted under a hood 12. The engine 13 is driven and driven. A chemical liquid tank 15 that surrounds the driver's seat 14 is mounted,
By transmitting the pump P mounted below, the chemical solution in the tank 15 is attached to the front part of the vehicle body 9 and the center boom 16 at the center part is mounted.
Alternatively, it can be pressure-fed to the left and right side booms 17 and sprayed from the nozzles 18 arranged on the booms 16 and 17. The booms 16 and 17 are moved up and down via an elevating link 20 as the elevating cylinder 19 extends and contracts. A center boom 16 having a predetermined width is horizontally attached to a front hitch 21 at the front end of the elevating link 20, and side booms 17 are attached to the left and right of the center boom 16 so as to be folded and stored backward.

The controller 2 and the control panel 23 of the spray control device 5 of the boom sprayer and the spray cocks C (C1, C1) of the booms 16 and 17 that can be manually opened and closed.
C2, C3) and the like are provided in the armrest cover 40 on the right side of the driver's seat 14. The chemical liquid circuit line of the spray control device 5 includes a pumping line 25 extending from the tank 15 to the pump P, a pump line 26 extending from the pump P to the flow rate control valve 24, the flow rate control valve 24 extending to each boom 16,
Ejection line 2 to 17 spray cocks C1, C2, C3
7 and are connected by a hose or the like.

The pump line 26 is provided with a return line 29 having a safety valve 28 for releasing a fluid pressure higher than a certain pressure so that the pump line 26 can be returned to the tank 15. Also, this tank 1
A stirring line 30 is connected between the bottom of the tank 5 and the bottom of the tank 5, and a part of the chemical liquid is constantly jetted and reduced into the tank 15 to stir the chemical liquid in the tank 15. The jet line 27 is provided with a pressure sensor 31 for detecting the hydraulic pressure and a flow rate sensor 32 for detecting the flow rate. Further, the opening degree of the flow rate control valve 24 is controlled by the control motor 33. 22 is a cock lever of each spray cock C1, C2, C3, 36 is a pressure regulating tank provided in the pump line 26, 39 is a flow control valve 24
An open / close sensor such as a potentiometer for detecting the open / close state is used for feedback control.

On the input side of the controller 2, the engine 1
3 is input by the engine rotation sensor 57,
A vehicle speed sensor 34 for detecting the vehicle speed from a traveling transmission device such as a mission case is provided. Also, the pressure sensor 31,
And the detection values of the flow rate sensor 32 are input. In addition, the main key switch 6 with the battery 35, the operation switches 37 arranged on the control panel 23 and the like are input. Reference numeral 7 is a key switch detection circuit for detecting ON / OFF of the main key switch 6, and 41 is a power supply for controlling the controller 2.

On the output side, an electromagnetic clutch 38 for turning on and off the transmission of the pump P, a control motor 33 for opening and closing the flow control valve 24, a liquid crystal display type display 1 of the control panel 23, etc. are output. Reference numeral 8 is a non-volatile memory capable of storing nozzle constant setting values and the like. Reference numeral 58 is a buzzer.

In such a spray control device 5, when the operating switches 37 are operated to set the spray amount of the chemical liquid to be sprayed and the increase / decrease switch, the reference spray flow rate is set to the vehicle speed sensor 3.
4 and the detected value of the pressure sensor 31, and while controlling the flow rate control valve 24, the chemical liquid volume in the ejection line 27 is
Control is performed so as to approach the reference spray flow rate. When the spray cocks C1, C2, C3, etc. are opened and the chemical liquid is sprayed from the booms 16, 17 to lower the hydraulic pressure in the jet line 27, the flow sensor 24 is opened by the pressure sensor 31, and the pump P is opened. Is increased to increase the hydraulic pressure in the jet line 27, and the value detected by the flow rate sensor 32 is controlled to be maintained at a constant reference spraying flow rate.

During such spraying control, when the discharge pressure of the pump P rises due to the high rotation of the engine 13 or the like, the safety valve 28 is used to drive the pump line 26.
Since the internal pressure of is maintained below a certain level, the internal pressure fluctuation of the ejection line 27 due to the opening and closing of the flow control valve 24 can be stabilized earlier than in the case where the safety valve 28 is not provided.

On the control panel 23, on the left side of the display 1 at the upper center, a display section for the spray setting 48, pressure 49, flow rate 50, cumulative flow rate 51, etc. is displayed from the upper side to the lower side. Triangular marks 44, 45, 46, 47 illuminated at the left end indicate the data content displayed on the display 1. A display switch button switch 43 is provided on the right side of the display 1. Below these are the automatic pushbutton switches 5
4 is provided, and this ON is indicated by the pilot lamp 55. Scatter setting button switch 42, increase button switch 52, decrease button switch 53, reset switch 56
An operation switch 37 such as is arranged.

Spraying is controlled by a selected spray amount according to the nozzle shape of the nozzles 18 of the chemical spray booms 16 and 17 attached to the front part of the vehicle body 9, and this selected spray amount is changed and set according to the non-selected nozzle boom. be able to. Therefore, first, while the spray setting button switch 42 is being pressed with the left hand, the main key switch 6 on the handle 10 side of the vehicle body 9 is operated from OFF to ON with the right hand. At this time, the engine 13 does not have to be started, but the control circuit of the controller 2 is energized. Here, the left hand is separated from the spray setting button switch 42, and the right hand is also separated from the main key switch 6.

At this time, a four-digit number appears on the display 1. Ignoring this, if the display changeover button switch 43 is pressed, the spray setting 48, pressure 49, flow rate 50,
Since any one of the triangular marks 44 to 47 of the cumulative flow rate 51 is turned on, the switching operation is performed so that the triangular mark 44 of the spray setting 48 is turned on.

In this way, the triangular mark 44 of the spray setting 48 is set.
When is turned on, the spray setting button switch 42 is pressed to select one of the plurality of flow rates. At this time, the spray amount per 10 are (anti) is, for example, 10 in advance.
Since four types of 0, 75, 50, and 25 (liter) are set, each time the spray setting button switch 42 is pressed, it is sequentially and repeatedly switched and displayed on the display 1. When any of the values shown on the display 1 is released, the value is held and selected when the switch 42 is released, and the chemical liquid spraying control can be performed according to the selected display value. Become.

However, the booms 16 and 17 mounted on the vehicle body 9
Is a non-selected nozzle boom that does not correspond to any of the preset nozzles, it can be set as follows. The nozzle ejection amount (for example, 0.33 liters / minute) when the hydraulic pressure of the non-selected nozzle boom (for example, 10 kilograms / square centimeter) is checked, and this numerical value is displayed and set on the display 1.

That is, after displaying one of the preset spray amounts by the above operation, the increase button switch 52 or the decrease button switch 53 is pressed once. Then, the nozzle constant q corresponding to the nozzle ejection amount currently registered in the memory 8 is displayed on the display 1. The nozzle ejection amount during this registration is
Further, the increase / decrease button switches 52 and 53 are kept pressed to change the nozzle constant of the non-selected nozzle boom.
When this ejection amount is displayed on the display 1, the hand is released from the increase / decrease button switches 52 and 53. This holds the display. Here, the automatic push button switch 54
By pressing and holding for 1 second, a stored value can be set for the nozzle ejection amount of the non-selected nozzle boom that has been display-held.

Here, this spraying control device mainly refers to FIGS. 1 and 7, and a spray line for sending the chemical liquid supplied from the pump P through the flow control valve 24 to the spraying boom by opening the spraying cock C. 27, a flow rate sensor 32 for detecting this flow rate and a pressure sensor 3 for detecting pressure
In the boom sprayer in which the spray pressure is controlled by the opening degree of the flow control valve 24, the flow sensor 3
When the flow rate detection value of 2 is less than or equal to a predetermined value and the pressure detection value of the pressure sensor 31 is within a predetermined range, it is characterized as "flow rate sensor abnormality".

Here, the abnormality determination of the flow rate sensor 32 is performed by the detection value of the flow rate sensor 32 and the pressure sensor 31 during spraying.
It is determined by the detected value of. As conditions for this abnormality determination, when the electromagnetic clutch 38 is engaged in the manual or automatic mode, the number of flow pulses for 0.5 seconds is n, and the detection value of the pressure sensor 31 is P (kilogram / square centimeter). 1. After determining that the detection value n ≦ 7 of 1.
When the pressure after 0 seconds is P <28, it is determined that the flow sensor 32 is abnormal. When P> 28, the flow rate sensor 32 is normal and the spray cock C is determined to be fully closed. Also, P <4
When, the flow rate sensor 32 is normal, and the engine 13 is determined to be stopped. Further, when 4 ≦ P ≦ 28, the flow rate sensor 32 is determined to be abnormal. Then, the flow control valve 24 does not change the opening degree for 1.0 second after determining that n ≦ 7.
When n ≧ 8, the flow rate sensor 32 is determined to be normal.

When the flow sensor 32 is determined to be abnormal, the abnormality processing mode (described later) is entered until the power supply 41 is turned off. When the power supply 41 is turned off, the abnormality determination is cleared. Therefore, the predetermined range of the pressure sensor 31 is 4 ≦ P ≦
When the pressure P> 28 outside 28, it is determined that the spray cock C is closed, and the flow rate sensor 32 becomes normal. This P ≧ 2
When the value reaches 8, the opening value by the opening sensor 39 of the flow control valve 24 at this time is stored in the memory 8. Pressure P
When <4, it is determined that the engine 13 is stopped, and the flow rate sensor 32 is normal.

When n ≧ 8, the flow rate sensor 32
Is normal, the opening of the flow control valve 24 is controlled to control the spray pressure. Next, mainly with reference to FIG. 8, this spraying control device, when the engine speed is equal to or higher than a predetermined value,
When the flow rate detection value of the flow rate sensor 32 is less than or equal to a predetermined value and the pressure detection value of the pressure sensor 31 is less than or equal to the predetermined value, it is determined as "flow rate sensor abnormality".

Further, this spray control device is mainly shown in FIG.
When the pressure in the jet line 27 becomes equal to or higher than a predetermined value when it is determined that the “flow sensor is abnormal” with reference to
The flow control valve 24 is operated in the closing direction by a predetermined amount, and when the pressure becomes a predetermined value or less, the pressure control is performed so that the pressure continues to be the set pressure. Processing control is performed when it is determined that "sensor abnormality".

In such an abnormality determination control, in order to prevent the non-dispersion state due to the spray boom, the spray cock C is fully closed in the following cases. That is, when the flow rate sensor 32 is below a predetermined value (n ≦ 7), the pressure sensor 31
When ≧ 28, the opening detection value by the opening / closing sensor 39 of the flow control valve 24 at this time is stored in the memory 8. When a higher pressure is detected, it is determined to be fully closed, and the opening degree of the flow control valve 24 is maintained until this pressure becomes P <28.

Further, when the motor 33 is driven in the closing direction of the valve 24 to reach the set pressure, if the pressure does not become less than 28 even if the opening degree of the valve 24 reaches the stored value, it is determined that the spray cock C is fully closed. It After this determination, the opening degree of the valve 24 is returned to the stored value. Further, when it is determined that the spray cock C is fully closed and the valve 24 opening is held, the holding is released when P <26, and the pressure control is started so as to reach the set pressure.

The elevating links 20 are provided in a pair of left and right and are elevated by elevating cylinders 19L and 19R, respectively. The side boom 17 is provided so as to be capable of expanding and contracting in the longitudinal direction so as to change the spraying width region, is operated by the opening / closing cylinders 59L and 59R in the spraying posture and the storing posture, and is vertically rotated by the vertical cylinders 60L and 60R. It is a configuration that is done.

The left and right side booms 17 are connected to the left and right ends of the center boom 16 via brackets 61. The bracket 61 is rotatably connected around an opening / closing shaft 62 in a substantially vertical direction, and opening / closing cylinders 59L and 59R are connected between the arm 63 and the center boom 16 which are integrated with the opening / closing shaft 62. This bracket 61
The base end of the side boom 17 is rotatably connected to the outer side of the rolling shaft 64 about the front-rear direction, and the upper and lower cylinders 60L and 60R are connected between the side boom 17 and the upper portion of the bracket 61. By this expansion and contraction, the side boom 17 can be rotated up and down to adjust the angle with respect to the spray surface.

Further, the extension and contraction of the side boom 17 is performed by expanding and contracting the slide boom 17 on the extension side with respect to the boom 17A on the base side.
B is slidably provided and is moved by a chain 65 driven by slide motors M7 and M8. The chain 65 is hung along the boom 17A and reciprocated by the forward and reverse rotations of the slide motors M7 and M8. The slide boom 17B is attached to the chain 65 by a connecting bracket 66.

These open / close cylinders 59L, 59R are of the form of a geared motor 67, and include open / close motors M3, M.
It is expanded and contracted by the transmission of 4. Lifting cylinder 19L, 1
9R and the upper and lower cylinders 60L and 60R are lift motors M
1, M2, vertical motors M5, M6, etc. and oil tank 6
8, the motors M1, M2, M5, M6 are electrically driven to rotate from the oil tank 68 to the lifting cylinders 19L,
The pressure oil is sent to 19R and the upper and lower cylinders 60L and 60R to expand and contract.

Mainly referring to FIGS. 4, 5, and 10 to 15, the operation control circuit 6 for the spraying posture of the spraying boom C is shown.
9, the lifting control is performed by switching the lifting switch SW1 up and down to electrically drive the lifting motors M1 and M2 by the relays R11 to R14 to move the lifting cylinder 19
L and 19R are simultaneously expanded and contracted, and the spray booms 16 and 17 are moved up and down. When the side boom 17 is opened and closed, the left and right opening / closing switches SW2 and SW3 are opened and closed to open and close the opening / closing motors M3 and M4 via the relay contacts R1 to R4.
Is driven to expand and contract the open / close cylinders 59L and 59R to open the side boom 17 in the spraying posture or close it in the storing posture.

Further, the vertical tilting posture of the side boom 17 and the expansion / contraction control for adjusting the spread width are switched by a pair of left and right operation levers 70 in the form of a joystick. Each operating lever 70 is formed with a cross-shaped lever guide 71 that can be tilted in four directions as shown in FIG. 14, and the up / down switches SW4 and SW5 are provided on the front and rear sides of the lever guide 71.
Is arranged, and the slide telescopic switch SW6 on both left and right sides,
SW7 is arranged. By operating the up / down switches SW4 and SW5, the up / down motor M is passed through relay contacts R5 to R8.
It is possible to adjust the vertical tilting (rolling) angle of the side boom 17 by electrically driving the M5 and M6 to expand and contract the upper and lower cylinders 60L and 60R. Also, slide expansion / contraction switches SW6, S
The slide boom 17B can be moved by electrically operating the slide motors M7 and M8 through the relay contacts R15 to R18 by operating W7.

As described above, by using the operating lever 70 for both the up and down operation of the side boom 17 and the slide telescopic operation, an accurate lever selection can be performed and the operability structure can be simplified. Further, the lever guide 71 is shown in FIG.
As shown in the figure, there are "up / extend", "up / shrink", and "down" in the middle between the up / down lever guide and the telescopic lever guide.
Form the position of each lever guide of "stretch" and "down / shrink",
By operating the lever 70 to each of these positions, the side boom 17 can be raised and extended simultaneously, or raised and retracted, lowered and extended, or lowered and retracted simultaneously.

In FIG. 16, the difference from the above example is that a chemical liquid mixing chamber 72 is provided in the jet line 27, and water sent from the tank 15 to the jet line 27 via the pump P is supplied from the chemical tank 73 to the chemical pump 74. It supplies chemicals and mixes them. 75 is a pressure control valve, and 76 is a motor for driving the pump 74, which is output from the controller 77. The water and the medicine are separately stored in the tanks 15 and 73, and sprayed while being mixed during the spraying work. Therefore, unnecessary waste of the medicine can be eliminated, and the number of steps such as cleaning the tank 15 can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a spray control device.

FIG. 2 is a partial wiring diagram.

FIG. 3 is a plan view of a control panel section.

FIG. 4 is a plan view of a boom sprayer.

FIG. 5 is a side view thereof.

FIG. 6 is a side view of the spray control device section.

FIG. 7 is a flowchart of a flow sensor abnormality determination of the spraying control.

FIG. 8 is a flowchart of flow sensor abnormality determination showing an embodiment of a part thereof.

FIG. 9 is a flowchart of processing control when the flow sensor abnormality is determined.

FIG. 10 is an enlarged front view of a side boom section.

FIG. 11 is a front view of the geared motor section.

FIG. 12 is a front view of the cylinder portion.

FIG. 13 is an operation control circuit diagram thereof.

FIG. 14 is a perspective view of the operation lever portion.

FIG. 15 is a perspective view of an operation lever portion showing an embodiment of a part thereof.

FIG. 16 is a block diagram of a spraying control device showing another embodiment.

[Explanation of symbols]

24 Flow control valve 27 gush line 31 Pressure sensor 32 Flow sensor 57 Engine rotation sensor C spray cock P pump

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Nagai             No. 1 Yakura, Tobe-cho, Iyo-gun, Ehime Prefecture             Technology Department Co., Ltd. (72) Inventor Norihiro Yano             No. 1 Yakura, Tobe-cho, Iyo-gun, Ehime Prefecture             Technology Department Co., Ltd. (72) Inventor Takanori Izumiya             No. 1 Yakura, Tobe-cho, Iyo-gun, Ehime Prefecture             Technology Department Co., Ltd. F term (reference) 2B121 CB02 CB13 CB24 CB33 CB42                       CB53 CB61 CB69 CC31 EA21                       FA11                 4D074 AA05 BB06 CC13 CC22 CC54                       CC57 CC60

Claims (4)

[Claims] 1. A flow sensor 32 for detecting the flow rate and a pressure for detecting the pressure in a jet line 27 for sending a chemical solution supplied from a pump P through a flow control valve 24 to a spray boom by opening a spray cock C. With sensor 31
In a boom sprayer in which the spraying capacity is controlled by the opening of the flow control valve 24, if the flow rate detection value of the flow rate sensor 32 is less than or equal to a predetermined value and the pressure detection value of the pressure sensor 31 is within a predetermined range, "flow rate sensor abnormality" is detected. Dispersion control device characterized by making a determination. 2. When the engine speed is equal to or higher than a predetermined value, if the flow rate detection value of the flow rate sensor 32 is equal to or lower than a predetermined value and the pressure detection value of the pressure sensor 31 is equal to or lower than the predetermined value, the flow rate sensor is abnormal. The spraying control device for a boom sprayer according to claim 1, wherein a determination is made. 3. When the pressure in the jet line 27 exceeds a predetermined value when it is determined that the "flow sensor is abnormal",
The boom according to claim 1 or 2, wherein the flow control valve 24 is operated in a closing direction by a predetermined amount, and when the pressure becomes equal to or lower than a predetermined value, pressure control is performed so that the pressure continues to be a set pressure. Sprayer spray control device. 4. When the flow rate control valve 24 is operated and the pressure does not fall below a predetermined value when it is determined that the flow rate sensor is abnormal, it is determined that the spraying cock is closed and the flow rate control valve 24 is turned on. The spray control device for a boom sprayer according to claim 1, 2, or 3, wherein the spray control device is operated so as to open the opening.