Self-travelling chemical applicator

Abstract

To improve maintainability by facilitating visual recognition of an accumulator.SOLUTION: A self-travelling chemical applicator includes: a travelling vehicle body (A) for causing a machine body to travel; an operation seat (a2) on which an operator is seated; an operation part (a6) for receiving an operation of the operator; a medicine application part (b1) that moves by an operation of a hydraulic cylinder; an accumulator connected to the hydraulic cylinder; a changeover valve for changing over supply and discharge of working fluid to and from the hydraulic cylinder, and actuating the hydraulic cylinder; and an on-off valve for opening / closing a passage for communicating the hydraulic cylinder with the accumulator. The accumulator is provided in front of a cabin (K) surrounding the operation seat (a2) so as to be visually recognized.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a self-propelled pesticide sprayer that sprays pesticides. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is known a self-propelled pesticide sprayer in which a pesticide spraying device equipped with a spray boom for spraying pesticides such as pest control liquid is mounted on the front of a traveling vehicle body.

[0003] For example, Patent Document 1 discloses a self-propelled chemical sprayer in which a lifting frame is provided on a lifting link that moves up and down by extending or retracting a lifting cylinder, and a spraying boom is attached to this lifting frame.

[0004] Here, the spray boom is supported by a cantilever so that one end is supported by the traveling vehicle body and the other end is the free end, so when the traveling vehicle body vibrates due to the unevenness of the field during work, the vibration is transmitted to the spray boom, causing it to vibrate violently. As a result, the spraying of the pesticide becomes uneven, leading to a decrease in work efficiency and pesticide spraying efficiency, so suppressing the vibration of the spray boom has been a long-standing issue.

[0005] Therefore, Patent Document 2 discloses a technology in which an accumulator that absorbs pressure fluctuations in the lifting cylinder is connected to the lifting cylinder, causing the accumulator to exert a spring action on the lifting cylinder, thereby reducing the vibration of the lifting frame and suppressing the vibration of the spray boom during work. Furthermore, Patent Document 3 discloses a technology in which an opening and closing valve is provided in the supply and discharge passage of hydraulic oil between the lifting cylinder and the accumulator, and when the lifting frame moves up and down, the opening and closing valve is closed to temporarily block the supply and discharge of hydraulic oil between the lifting cylinder and the accumulator, thereby improving the responsiveness of the spray boom to the lifting and lowering operation. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-17310 A [Patent Document 2] JP 2013-102 A [Patent Document 3] JP 2017-23041 A Summary of the Invention [Problem to be solved by the invention]

[0007] Here, according to a self-propelled pesticide sprayer that applies the prior art disclosed in Patent Documents 2 and 3, when the accumulator absorbs pressure fluctuations in the lifting cylinder and exerts a spring action, the spray boom is not fixed to the running body of the self-propelled pesticide sprayer and can swing up and down.

[0008] Patent Documents 2 and 3 do not disclose any configuration regarding the installation position of the accumulator.

[0009] There was a problem that even if a malfunction such as an oil leak from the accumulator occurred, it was not easy for the operator to grasp the problem while operating the machine.

[0010] To solve the conventional problems by providing a self-propelled chemical sprayer that enables an operator to easily find a malfunction of an accumulator while operating the machine while seated in the driver's seat. [Means for solving the problem]

[0011] In order to achieve the above object, the invention of claim 1 provides a self-propelled pesticide sprayer comprising a traveling vehicle body (A) for propelling the machine, a driver's seat (a2) on which an operator sits, an operation unit (a6) for receiving operations from the operator, a pesticide spraying unit (b1) that moves by the operation of a hydraulic cylinder, an accumulator connected to the hydraulic cylinder, a switching valve that switches the supply and discharge of hydraulic oil to the hydraulic cylinder to operate the hydraulic cylinder, and an opening and closing valve that opens and closes a passage that connects the hydraulic cylinder and the accumulator, wherein the driver's seat (a2) The accumulator can be seen while seated on the The self-propelled pesticide sprayer is characterized by being equipped with a

[0012] The invention of claim 2 is as follows: The valve can be opened and closed by a key switch that starts and stops the engine. The self-propelled pesticide sprayer according to claim 1 is characterized in that

[0013] The invention of claim 3 is as follows: When a key switch for starting and stopping the engine is turned on, the on-off valve is switched to a communicating position to activate the vibration damping function of the accumulator, and when a rise switch or a fall switch for raising and lowering the chemical spraying unit (b1) is turned on, the on-off valve is switched to a blocking position to deactivate the vibration damping function of the accumulator, and when a predetermined time has elapsed since the on-operation of the rise switch or the fall switch and during the raising and lowering operation of the chemical spraying unit (b1), the on-off valve is switched to the communicating position to resume the vibration damping function of the accumulator. The self-propelled pesticide sprayer according to claim 2 is characterized in that

[0014] According to the invention recited in claim 1, a failure in the accumulator can be easily visually confirmed.

[0015] It also improves maintainability.

[0016] According to the invention described in claim 2, in addition to the effects of the invention described in claim 1, This improves convenience by eliminating the need to manually operate the on-off valve. In addition, the worker will not forget to open the on-off valve while working. In addition, a switch to turn the on-off valve on and off is no longer necessary.

[0017] According to the invention described in claim 3, When the up switch or down switch for raising and lowering the chemical spraying unit (b1) is turned on, the on-off valve is switched to the shutoff position to deactivate the vibration suppression function of the accumulator, so that the chemical spraying unit (b1) quickly responds to the up-and-down operation and rises and falls. In addition, the vibration during the up-and-down operation can be reduced by resuming the vibration suppression function of the accumulator during the up-and-down operation after a predetermined time has elapsed since the up-and-down operation. [Brief description of the drawings]

[0018] [Figure 1] 1 is a perspective view of a self-propelled drug sprayer according to a preferred embodiment of the present invention. [Diagram 2] FIG. 2 is a left side view of the self-propelled pesticide sprayer of FIG. 1. [Diagram 3] FIG. 2 is a plan view of the self-propelled pesticide sprayer of FIG. 1. [Figure 4] FIG. 2 is a front view of the self-propelled pesticide sprayer of FIG. 1. [Diagram 5] 2 is a circuit diagram showing a part of a hydraulic circuit of the self-propelled pesticide sprayer of FIG. 1. [Figure 6] 2 is an enlarged front view of the main parts of the self-propelled pesticide sprayer of FIG. 1. [Figure 7] 6 is a flowchart showing a control procedure by a controller in FIG. 5. [Figure 8] 8 is a flowchart showing a procedure by a controller for the spraying boom lifting and lowering process of FIG. 7. [Figure 9] 6 is a time chart showing the operation of the accumulator in FIG. 5. [Figure 10]A front view of a self-propelled pesticide sprayer according to another embodiment of the present invention. [Figure 11] 11 is a circuit diagram showing a part of a hydraulic circuit of the self-propelled chemical sprayer of FIG. 10. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the description of the embodiment, the left and right directions facing the forward movement direction of the aircraft are referred to as left and right, respectively, and the forward movement direction is referred to as front and the rearward movement direction is referred to as rear, but this does not limit the configuration of the present invention.

[0020] (Overall composition) An example of the overall configuration of the self-propelled chemical sprayer 1 will be specifically described.

[0021] As shown in Figure 1 (oblique view), Figure 2 (left side view), Figure 3 (plan view), and Figure 4 (front view), the self-propelled pesticide sprayer 1 comprises a self-propelled running body A, a cabin K provided on the running body A, a pesticide tank M for storing pesticide, and a pesticide spraying device B having a spraying boom b1 for spraying the pesticide supplied from the pesticide tank M over a farm field.

[0022] The traveling vehicle body A includes a main frame a1, a driver's seat a2, a steering handle a3, front wheels a4, and rear wheels a5. The main frame a1 is formed by extending from the front to the rear of the traveling vehicle body A. The driver's seat a2 is a seat for an operator to sit on when driving and operating the riding pest control device 1. At an appropriate position around the driver's seat a2, an operation panel a6 is arranged with operation switches and key switches for controlling operations such as opening and closing the spraying boom b1 and spraying pesticides.

[0023] The steering handle a3 provided in front of the driver's seat a2 is turned by the operator to steer at least the left and right front wheels a4, a4, thereby changing the traveling direction of the self-propelled drug sprayer 1. In other words, the front wheels a4, a4 ​​are steered wheels that are steered at least by turning the steering handle a3.

[0024] The power of the engine inside the bonnet a7 is appropriately changed in speed inside a transmission case (not shown), and the changed speed power is transmitted to the front wheels a4 and the rear wheels a5 to rotate and drive them.

[0025] The cabin K forms a passenger compartment by surrounding the driver's seat a2 and its surrounding equipment, the steering wheel, etc. The cabin K is disposed between the chemical tank M and the spraying boom b1. The cabin K is composed of a cabin frame k1, a cabin roof k2, left and right opening doors k3L, k3R, etc.

[0026] The chemical tank M is a container for storing chemicals. As shown in FIG. 3 in a plan view, the chemical tank M is disposed at the rear of the cabin K, and is formed in a U-shape so as to surround both the left and right sides and the rear of the driver's seat a2, and is removably mounted on the main frame a1. The chemicals stored in the chemical tank M are liquids such as liquids in which fertilizers, pesticides, etc. are dissolved in a solvent (e.g., water), and liquids (e.g., water) containing solids such as fertilizers, pesticides, etc.

[0027] (Drug dispersal device) The chemical spraying device B is configured to include a spray boom b1 for spraying in a farm field, and a support device b2 for supporting the spray boom b1 on the traveling vehicle body A.

[0028] The spreading boom b1 is composed of a center boom b1F located in front of the traveling body 2, and side booms b1L, b1R located on both sides.

[0029] The center boom b1F extends horizontally in the vehicle width direction of the traveling vehicle body 2. In addition, a plurality of nozzles bn that spray the agent in a mist form are arranged at intervals on the center boom b1F.

[0030] The side booms b1L, b1R are rotatably arranged on both the left and right sides of the center boom b1F. A plurality of nozzles bn for spraying the chemicals in a mist are arranged at intervals on the side booms b1L, b1R. By rotating the side booms b1L, b1R, the spraying boom b1 can be switched between a spraying posture in which the entirety is substantially linear so as to extend in the vehicle width direction (left-right direction) of the traveling body A, and a retracted posture in which the side booms b1L, b1R are aligned along both the left and right sides of the traveling body 2. In the spraying posture, the spraying boom b1 configured in this manner can spray the chemicals widely to the left and right of the front side of the self-propelled chemical sprayer 1.

[0031] As shown in Fig. 2 and Fig. 3, the support device b2 is a device that supports the spraying boom b1 on the traveling vehicle body A so that it can be raised and lowered, and is configured to include a lifting link b20 that rotates by extending or shortening the lifting cylinder b21, a mounting frame b21 connected to the front end of the lifting link b20, a lifting frame b23 that is attached to the mounting frame b22 and moves up and down by rotating the lifting link b20, and opening and closing cylinders b24, b24 that rotate the side booms b1L, b1R on both sides approximately horizontally to open and close them. As shown in Fig. 4, the mounting frame b22 has a rectangular frame shape when viewed from the front, and is configured to pivotally support the lifting frame b23 around the rolling axis Y by the rolling axis Y provided at the lower part.

[0032] A center boom b1 (b1F) is attached to the front of the lifting frame b23, and side booms b1L, b1R are rotatably attached to the left and right sides of the lifting frame b23 so that they can be deployed in the vehicle width direction. With this configuration, when the lifting frame b23 rises and falls, the spraying boom b1 also rises and falls.

[0033] The opening and closing cylinders b24, b24 can be switched between a spraying posture extending in the vehicle width direction of the traveling body A and a storage posture along both the left and right sides of the traveling body A by extending or retracting, and are connected to the lifting frame b23 and the side booms b1L, b1R, so that when the opening and closing cylinders b24, b24 are extended or retracted, the side booms b1L, b1R on both sides rotate. The extension or retraction of the opening and closing cylinders b24, b24 is controlled by a controller C, which will be described later.

[0034] (Spraying boom vibration control device) As shown in FIG. 4, an accumulator U for absorbing pressure fluctuations in the lift cylinder b24 is attached to the lift frame b23.

[0035] FIG. 5 is a circuit diagram showing a part of the hydraulic circuit of the self-propelled chemical sprayer 1. As shown in FIG.

[0036] As shown in Figure 5, the vibration damping mechanism of the spraying boom b1 is composed of an accumulator U, an on-off valve u1 provided in a hydraulic oil supply / discharge passage connecting the lifting cylinder b21 and the accumulator U, and a controller C capable of controlling the opening and closing of the on-off valve u1.

[0037] The first and second pumps P1, P2, which are hydraulic pumps, are composed of fixed displacement gear pumps driven by engine power. A discharge oil passage 100, which distributes hydraulic oil discharged from the first and second pumps P1, P2, is connected to a first constant flow division valve u2, which distributes a constant flow rate. The first constant flow division valve u2 is connected to a second constant flow division valve u3 by a first oil passage 101. The second constant flow division valve u3 is connected to a discharge oil passage 100a, which distributes discharge oil (pilot oil) discharged from the third pump P3. The second oil passage 102 connects to a vertical movement switching valve u4.

[0038] The up-down movement switching valve u4 is an electromagnetic switching valve that can be switched between an extension position u41, which is an operating position for extending the lift cylinder b21, a contraction position u42, which is an operating position for contracting the lift cylinder b21, and a stop position u43, which stops the lift cylinder b24.

[0039] The up-down switching valve u4 is connected to the second oil passage 102, as well as to a third oil passage 103 which communicates with the left and right lift cylinders b21, b21 and the opening / closing valve u1, and to a discharge oil passage 104 which returns hydraulic oil to the hydraulic oil tank T. A relief valve u5 is provided between the second oil passage 102 and the discharge oil passage 104, which opens when the hydraulic pressure in the second oil passage 102 exceeds a set value to release the hydraulic pressure to the discharge oil passage 104.

[0040] When the vertical movement switching valve u4 is switched to the extended position u41, the second oil passage 102 and the third oil passage 103 are communicated, and the hydraulic oil discharged from the first and second pumps P1 and P2 flows into the piston side chambers b211, b211 of the lifting cylinders b21, b21 through the discharge oil passage 100, the first oil passage 101, the second oil passage 102 and the third oil passage 103. As a result, the lifting cylinders b21, b21 are extended, and accordingly the lifting link b20 is rotated upward and the lifting frame b23 moves upward, and the spraying boom b1 rises together with the lifting frame relative to the traveling vehicle body 2.

[0041] When the up-down switching valve u4 is switched to the contracted position u42, the discharge oil passage 104 and the third oil passage 103 are connected. As a result, the hydraulic oil in the piston side chambers b211, b211 of the lifting cylinders b21, b21 is returned to the hydraulic oil tank T through the third oil passage 103 and the discharge oil passage 104. As a result, the lifting cylinder b21 contracts, so the lifting link b20 is rotated downward and the lifting frame b23 moves downward, and the spraying boom b1 descends together with the lifting frame b23 relative to the traveling vehicle body A.

[0042] When the vertical movement switching valve u4 is switched to the stop position u43, the third oil passage 103 is closed. This blocks the hydraulic oil flowing in and out of the piston side chambers b211, b211 through the third oil passage 103, and the height of the spraying boom b1 relative to the traveling vehicle body A is maintained.

[0043] The on-off valve u1 is an electromagnetic switching valve that can be switched between a communication position u11 that communicates between the piston side chamber b211 of the lift cylinder b21 and the accumulator U, and a blocking position u12 that blocks the communication.

[0044] When the on-off valve u1 is switched to the communication position u11 (open control of the on-off valve u1), the third oil passage 103 communicates with the accumulator U, and thus the piston side chamber b211 of the lifting cylinder b21 communicates with the accumulator U. As a result, the hydraulic oil flows between the two, and the accumulator U absorbs the pressure fluctuations in the lifting cylinder b21 and exerts a spring action, suppressing the vibration of the spraying boom b1 and exerting a vibration damping function.

[0045] When the on-off valve u1 is switched to the shutoff position u12 (control to close the on-off valve u1), the communication between the third oil passage 103 and the accumulator U is shut off, and therefore the communication between the piston side chamber b211 of the lifting cylinder b21 and the accumulator U is shut off. This stops the vibration damping function of the accumulator U, and improves the responsiveness when lifting and lowering the spraying boom b1. In particular, the responsiveness refers to the promptness from when the boom raising switch or the boom lowering switch is operated until the lifting and lowering operation of the spraying boom b1 starts.

[0046] The controller C is a control device capable of controlling the vertical movement switching valve u4 and the on-off valve u1, and is configured to include a CPU, ROM, RAM, etc., and stores a predetermined control program. The vertical movement switching valve u4 and the on-off valve u1 are electrically connected to the controller C, and are controlled by the controller C to switch their positions. The controller C may be configured to control the positions of the vertical movement switching valve u4 and the on-off valve u1 using a timer, relay, etc., without using a CPU, ROM, RAM, etc.

[0047] The controller C is electrically connected to the operation panel a6, and can obtain the operation of various operation switches provided on the operation panel a6 as signals. That is, the operation information of the operation panel a6 by the operator can be obtained. The operation panel a6 is provided with at least a boom raising switch (not shown) operated when raising the spray boom b1 relative to the traveling vehicle body A, a boom lowering switch operated when raising the spray boom b1 relative to the traveling vehicle body A, and a key switch operated when turning on the power to the self-propelled chemical sprayer 1. The key switch is an operation switch that can be switched on and off, and the condition for the engine operation of the self-propelled chemical sprayer 1 is that the key switch is in the on state. Therefore, the operator can operate the engine of the self-propelled chemical sprayer 1 by performing a predetermined operation after turning on the key switch. The controller C executes the control described below based on the signal from the operation panel a6, and switches the positions of the up-down movement switching valve u4 and the opening / closing valve u1. Also connected to the controller C are a timer c1 as a timekeeping means, and a relay c2 that detects the operation of the key switch and switches the contacts in the circuit.

[0048] FIG. 6 is an enlarged front view of the main parts of the self-propelled chemical sprayer 1. As shown in FIG.

[0049] As shown in Fig. 6, the accumulator U is disposed in the approximate left-right center of the lifting frame b23 in front of the cabin K, and is located approximately on the center line in the vehicle width direction of the traveling body 2. As a result, the accumulator U disposed approximately in the center of the traveling body A serves as a center marker, making it easy for the operator to operate the self-propelled chemical sprayer 1 in a straight line. In addition, it becomes easy to visually check for any malfunctions of the accumulator U, improving maintainability.

[0050] Also, the on-off valve u1 is accommodated in the housing X1 arranged below the accumulator U shown in FIG. 6, and the vertical movement switching valve u4 is accommodated in the housing X2 arranged adjacent to the side of the housing X1. The accumulator U may be configured to be detachable from the housing X1. As shown in FIG. 6, the housings X1 and X2 are attached and fixed adjacent to the lift frame b23, and the on-off valve u1 and the vertical movement switching valve u4 are arranged adjacent to each other. The housings X1 and X2 may be configured as a single housing, and the on-off valve u1 and the vertical movement switching valve u4 may be accommodated in this single housing. In this way, the on-off valve u1 and the vertical movement switching valve u4 are directly mounted integrally, which provides good assembly, reduces the number of assembly steps, and makes the installation space compact.

[0051] The accumulator U, the housing X1, and the housing X2 are configured to be provided at the front of the traveling vehicle body 2. Specifically, they are configured to be provided at the very front of the body. This makes maintenance easy. Also, the spray boom b1 to which the nozzle bn is attached can be raised and lowered to any position by raising and lowering the lifting frame b23. The accumulator U, the housing X1, and the housing X2 are attached to the lifting frame b23.

[0052] As a result, the accumulator U, the housing X1, and the housing X2 can be raised and lowered to any position while maintaining their respective positional relationships, without affecting the piping and facilitating maintenance management.

[0053] (Valve opening and closing control) FIG. 7 is a flowchart showing a control procedure by the controller C.

[0054] The controller C controls the on-off valve u1 and the up-down switching valve u4 in accordance with the procedure shown in the flowchart of Fig. 7. As an initial condition, the key switch is turned off and the on-off valve u1 is switched to the shutoff position u12.

[0055] When the controller C receives a signal indicating that the key switch has been turned on (step S101), it controls the on-off valve u1 to be switched to the communication position u11 (step S102). This allows the accumulator U to exert its vibration damping function, thereby suppressing the vibration of the spraying boom b1. In this way, according to the configuration in which the on-off valve u1 is opened in conjunction with the operator turning on the key switch, the on-off valve u1 is reliably opened when only the power is on and the engine is stopped or running, or during work. This eliminates the need for the operator to manually open the on-off valve u1 as in the past, improving convenience. In addition, there is no risk of the operator forgetting to manually open the on-off valve u1 during work. In addition, a switch for turning the on-off valve u1 on and off is no longer necessary.

[0056] Next, when the controller C acquires a signal indicating that the boom up switch or the boom down switch has been turned on (step S103), it executes a process of raising and lowering the spreading boom b1, which will be described later (step S104).

[0057] In addition, after controlling the on-off valve u1 to be switched to the communication position u11 in step S102, when the controller C receives a signal indicating that the key switch has been turned off (step S105), it controls the on-off valve u1 to be switched to the shutoff position u12 (step S106). This causes the vibration damping function of the accumulator U to be stopped in conjunction with the key switch being turned off. In this way, by automatically turning off the vibration damping function of the accumulator U when not in operation, the configuration in which the spray boom b1 is fixed to the traveling vehicle body A can prevent the spray boom b1 from swinging up and down and coming into contact with an external obstacle when not in operation, such as when the self-propelled chemical sprayer 1 is being transported. In addition, when the accumulator U is removed for maintenance management, the on-off valve u1 is switched to the shutoff position u12, so that dust and the like can be prevented from entering the hydraulic circuit.

[0058] Fig. 8 is a flow chart showing the procedure by the controller C of the spraying boom lifting process (step S104) in Fig. 7. When the controller C acquires a signal indicating that the boom up switch is turned on or the boom down switch is turned on in step S103, if the controller C acquires a signal indicating that the boom up switch is turned on, the controller C switches the vertical movement switching valve u4 to the extended position u41 and raises the spraying boom b1. If the controller C acquires a signal indicating that the boom down switch is turned on, the controller C switches the vertical movement switching valve u4 to the retracted position u42 and lowers the spraying boom b1 (step S201).

[0059] At the same time, the on-off valve u1 is immediately switched to the shutoff position u12 (step S202), which can improve the responsiveness of the subsequent lifting and lowering of the spraying boom b1.

[0060] Here, the controller C starts the timer c1 at the same time as the start of raising and lowering the spraying boom b1, and counts the set time t (step S203). This set time t is preset to a predetermined short time, for example, about 1 second.

[0061] Next, when the set time t has elapsed, the controller C switches the on-off valve u1 to the communication position u11 (step S204). That is, the controller C immediately switches the on-off valve u1 to the blocking position u12 only for a short time immediately after the start of the lifting and lowering operation of the spraying boom b1, and switches the on-off valve u1 to the communication position u11 during the lifting and lowering operation of the spraying boom b1 after the start of the lifting and lowering. This ensures quick response during the lifting and lowering operation of the spraying boom b1, and furthermore, during the lifting and lowering operation of the spraying boom b1 after the start of the lifting and lowering, the vibration damping function of the accumulator U can be exerted to reduce the vibration of the spraying boom b1. As a result, the operation of the spraying boom b1 is stabilized, and safety can be improved. That is, according to the conventional configuration in which the opening and closing valve u1 is controlled to be open after the lifting and lowering operation of the spray boom b1 is completed, when the opening and closing valve u1 is opened, the hydraulic oil rapidly flows from the lifting and lowering cylinder b21 to the accumulator U side due to the pressure difference between the hydraulic oil of the lifting and lowering cylinder b21 and the accumulator U, and as a result, the lifting and lowering cylinder b21 is extended or shortened, and the spray boom b1 is lowered below the stop position, which may cause the operation to become unstable. However, by controlling the opening and closing valve u1 to be open during the lifting and lowering operation of the spray boom b1, the pressure difference between the hydraulic oil of the lifting and lowering cylinder b21 and the accumulator U is eliminated, and the stable operation of the spray boom b1 can be realized. Here, the set time t is preferably set within 0.5 to 3 seconds, and more preferably within 0.5 to 1 second.

[0062] Next, when the controller C receives a signal indicating that the boom up switch or the boom down switch has been turned off (step S205), it controls the vertical movement switching valve u4 to be switched to the stop position u43 (step S206). This stops the lifting and lowering of the spraying boom b1, and the spraying boom b1 lifting and lowering process (step S104) in FIG. 7 is completed.

[0063] Although not shown in Figs. 7 and 8, when the boom up switch or the boom down switch is operated continuously for a predetermined time (approximately 0.5 to 1 second), the spraying boom b1 is not raised or lowered, and the opening and closing valve u1 is manually closed. In this case, other switches or levers may be provided instead of the boom up switch or the boom down switch. This allows the operator to easily stop the operation of the accumulator U in a situation where it is not necessary to operate the accumulator U (for example, when the road surface is not uneven). When the accumulator U is to be operated again, the boom up switch or the boom down switch is operated continuously for a predetermined time (approximately 0.5 to 1 second). This eliminates the need for a switch to turn the opening and closing valve u1 on and off.

[0064] Also, a vibration sensor may be provided on the machine body, and when the vibration of the machine body is within a predetermined value and continues for a predetermined time or more, the on-off valve u1 is automatically closed to stop the operation of the accumulator U. However, if the vibration value exceeds the predetermined value at least several times, the on-off valve u1 is automatically opened to operate the accumulator.

[0065] Furthermore, the boom up switch and boom down switch are provided in positions that can be operated while seated in the driver's seat a2 inside the cabin K, but they are also provided outside the cabin K. As shown in Fig. 2, since the side boom b1L passes beside the opening and closing door k3L, it is possible to get on and off by passing under the side boom b1L, but it is easier to get on and off by raising and lowering the side boom b1L when getting on and off. Therefore, the side boom b1L is configured to be able to be raised and lowered by operating a boom up switch or boom down switch provided outside the cabin K.

[0066] The side booms b1L, b1R are configured to be able to rise and fall independently of the lifting frame b23, and are configured to be able to rise and fall by an electric hydraulic cylinder ES that is independent of the hydraulic circuit in Fig. 5. In this case, even if the engine is stopped and the hydraulic pressure is not operating, the side booms b1L, b1R are raised and lowered by operating the boom up switch and boom down switch outside the cabin K to drive the electric hydraulic cylinder ES using the battery power. This makes it easy for people to get in and out of the cabin K.

[0067] FIG. 9 is a time chart showing the operation of the accumulator U in FIG.

[0068] In Fig. 9, when the accumulator U is on, the on-off valve u1 is in a communication position u11, and when the accumulator U is off, the on-off valve u1 is in a cut-off position u12. As shown in Fig. 9, when the key switch is on, the accumulator U is normally on, but the accumulator U is configured to be off for a set time t immediately after the boom up switch or the boom down switch is turned on. As described above, the set time t is preset to a short time (for example, about 1 second), but in order to realize the responsiveness of the lifting and lowering of the spraying boom b1 according to the weight of the spraying boom b1 and the needs of the operator, it can be adjusted within a predetermined range (for example, about 0.5 seconds to 3 seconds) by operating the operation panel a6.

[0069] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims, and it goes without saying that these modifications are also included within the scope of the present invention.

[0070] For example, in the above embodiment, as shown in Fig. 4, the lifting frame b23 is pivotally supported around the rolling axis Y by the rolling axis Y provided at the bottom of the mounting frame b22, but as shown in Fig. 10, the single-acting roll cylinder b25 may be disposed at one left or right end of the lifting frame b23, and a damper b26 may be disposed at the other left or right end, and the lifting frame b23 may be controlled to roll by extending or shortening the single-acting roll cylinder b25. In this case, by performing the return operation of the single-acting roll cylinder b25 by the damper b26 disposed at the other left or right end, the swaying vibration of the lifting frame in the rolling direction can be suppressed compared to the case of using an elastic body such as a compression spring, and stable roll control is possible.

[0071] Fig. 11 is a circuit diagram showing a part of the hydraulic circuit of the self-propelled chemical sprayer 1 according to another embodiment. In addition to the configuration of the hydraulic circuit shown in Fig. 5, the hydraulic circuit of the self-propelled chemical sprayer 1 according to another embodiment has a fourth oil passage 105 connected to the first constant flow distribution valve u2, and further has a single-acting roll cylinder switching valve u5 connected to the fourth oil passage 105, which is an electromagnetic switching valve that can switch the single-acting roll cylinder b25 between an extension position u51 as an operating position for extending the single-acting roll cylinder b25, a contraction position u52 as an operating position for contracting the single-acting roll cylinder b25, and a stop position u53 for stopping the single-acting roll cylinder b25. The lifting frame b23 is pivotally supported so as to be rotatable about the rolling axis Y, and the accumulator U2 is configured to perform vibration suppression in the rolling direction of the lifting frame b23.

[0072] As shown in FIG. 11, the single-acting roll cylinder switching valve u5 is connected to the fifth oil passage 106, and the fifth oil passage 106 is connected to a second on-off valve u7 that can be switched between a communication position u71 that communicates between the piston side chamber b251 of the single-acting roll cylinder b25 and the roll accumulator U2 and a blocking position u72 that blocks the communication. When the controller C receives a signal indicating that the key switch is turned on, it controls the on-off valve u7 to be switched to the communication position u71. This allows the accumulator U2 to exert a vibration suppression function, suppressing vibration of the lifting frame b23 in the rolling direction. In addition, when the accumulator U2 is removed for maintenance, the on-off valve u7 is switched to the blocking position u72, preventing dust and the like from entering the hydraulic circuit.

[0073] The single-acting roll cylinder switching valve u5 is connected to a second drain oil passage 107 that returns hydraulic oil to the hydraulic oil tank T, and a relief valve u6 is provided between the fourth oil passage 105 and the second drain oil passage 107. Although not shown, the single-acting roll cylinder switching valve u5 and the second on-off valve u7 are connected to a controller C, and their positions can be controlled by the controller C. The single-acting roll cylinder switching valve u5 and the second on-off valve u7 are housed in a housing X3 shown in FIG.

[0074] Here, in a plan view of the aircraft, the accumulators U and U2 may be arranged on either the left or right side of the center line of the aircraft traveling direction, and the hydraulic valve may be arranged on the other side. In this way, by distributing the heavy accumulators and hydraulic valves to the left and right sides of the center line of the aircraft traveling direction, the left and right balance of the aircraft is improved.

[0075] Also, an indicator light indicating that the on-off valves to the accumulators U, U2 are open and the accumulators U, U2 are operable may be provided near the key switch or around the handle of the operating unit. This allows the worker to easily check the operating status of the accumulators U, U2 while the vehicle is stopped or traveling (working, traveling). This configuration is particularly effective when there is no on / off switch for the accumulators U, U2 (a configuration in which the accumulators U, U2 are automatically operated in conjunction with the on / off of the key switch). [Explanation of symbols]

[0076] A Running vehicle a1 mainframe a2 Driver's seat a3 steering wheel 4 Front Wheel a5 rear wheel a6 operation panel a7 bonnet B. Chemical spraying device bn nozzle b1 Spraying boom b2 Support device b 20 Lifting link b21 Lifting cylinder b22 mounting frame b23 Lifting frame b24 Opening and closing cylinder b25 Single-acting roll cylinder K Cabin k1 cabin frame k2 cabin roof k3L, k3R Opening and closing door T Hydraulic Oil Tank U Accumulator U2 Roll Accumulator P1 First pump P2 Second pump u1 On-off valve u2 First constant flow valve u3 Second constant flow valve u4 Up and down switching valve u5 Single-acting roll cylinder switching valve u6 relief valve u7 Second opening and closing valve Y Rolling Axis

Claims

1. A traveling vehicle body (A) that drives the machine, a driver's seat (a2) on which an operator sits, an operation unit (a6) that accepts operations by the operator, a drug spraying unit (b1) that moves by the operation of a hydraulic cylinder, and an accumulator connected to the hydraulic cylinder; a switching valve that switches the supply and discharge of hydraulic oil to the hydraulic cylinder to operate the hydraulic cylinder; A self-propelled pesticide sprayer including an on-off valve for opening and closing a passage connecting the hydraulic cylinder and the accumulator, A self-propelled pesticide sprayer, characterized in that the accumulator is arranged visibly in front of a cabin (K) surrounding the driver's seat (a2).

2. 2. The self-propelled chemical sprayer according to claim 1, further comprising a plurality of said accumulators.

3. 3. A self-propelled chemical sprayer according to claim 1, wherein the on-off valve can be opened and closed by a key switch which starts and stops the engine.

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