JP7571827B2 - Self-propelled pesticide sprayer - Google Patents

Description

The present invention relates to a self-propelled pesticide sprayer that sprays pesticides.

Conventionally, a self-propelled pesticide sprayer is known that is equipped with a spray boom for spraying pesticides such as pesticide liquid and is mounted on the front of the vehicle body.

For example, Patent Document 1 discloses a self-propelled pesticide sprayer in which a lifting frame is attached to a lifting link that moves up and down by extending or shortening a lifting cylinder, and a spray boom is attached to this lifting frame.

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. Therefore, when the traveling vehicle body vibrates due to unevenness in the field during operation, the vibration is transmitted to the spray boom, causing it to vibrate violently. This results in uneven spraying of the pesticide, leading to reduced work efficiency and pesticide spraying efficiency, so suppressing the vibration of the spray boom has long been a challenge.

Patent Document 2 discloses a technique for suppressing vibration of the spray boom during operation by connecting an accumulator to the lifting cylinder, which absorbs pressure fluctuations within the lifting cylinder, and using the accumulator to exert a spring effect on the lifting cylinder, thereby reducing the vibration of the lifting frame. Furthermore, Patent Document 3 discloses a technique for providing an opening and closing valve in the hydraulic oil supply and discharge passage between the lifting cylinder and the accumulator, and closing the opening and closing valve when the lifting frame moves up and down 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.

JP 2019-17310 A JP 2013-102 A JP 2017-23041 A

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 effect, the spray boom is not fixed to the running body of the self-propelled pesticide sprayer and can swing up and down.

Patent Document 2 and Patent Document 3 do not describe the configuration regarding the installation position of the accumulator.

When a malfunction such as an oil leak from the accumulator occurred, the operator could not easily grasp it while the machine was in operation.

The aim is to solve the problems of the past by providing a self-propelled pesticide sprayer that allows an operator to easily detect accumulator failures while operating the machine while seated in the driver's seat.

In order to achieve the above-mentioned object, the invention of claim 1 is a self-propelled pesticide sprayer comprising a running body (A) for propelling the machine, a driver's seat (a2) on which an operator sits, an operating unit (a6) for receiving operation 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 connecting the hydraulic cylinder and the accumulator, characterized in that the accumulator is arranged visible in front of a cabin (K) surrounding the driver's seat (a2).

The invention of claim 2 is a self-propelled drug sprayer as described in claim 1, characterized in that multiple accumulators are provided.

The invention of claim 3 is a self-propelled pesticide sprayer as described in claim 1 or claim 2, characterized in that the on-off valve can be opened and closed by a key switch that starts and stops the engine.

According to the invention described in claim 1, it becomes easy to visually check for accumulator failures.

It also improves maintainability.

According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, the vibration damping function of the drug spraying part is improved.

According to the invention described in claim 3, the effort of manually operating the on-off valve is eliminated, improving convenience. In addition, the worker will not forget to open the on-off valve while working. In addition, a switch for turning the on-off valve on and off is no longer necessary.

1 is a perspective view of a self-propelled drug sprayer according to a preferred embodiment of the present invention. FIG. 2 is a left side view of the self-propelled pesticide sprayer of FIG. 1. FIG. 2 is a plan view of the self-propelled pesticide sprayer of FIG. 1. FIG. 2 is a front view of the self-propelled pesticide sprayer of FIG. 1. 2 is a circuit diagram showing a portion of the hydraulic circuit of the self-propelled pesticide sprayer of FIG. 1. 2 is an enlarged front view of the essential parts of the self-propelled pesticide sprayer of FIG. 1. 6 is a flowchart showing a control procedure by the controller of FIG. 5 . 8 is a flowchart showing a procedure by a controller for the spraying boom lifting and lowering process of FIG. 7 . 6 is a time chart showing the operation of the accumulator of FIG. 5 . A front view of a self-propelled pesticide sprayer according to another embodiment of the present invention. 11 is a circuit diagram showing a portion of the hydraulic circuit of the self-propelled pesticide sprayer of FIG. 10.

Below, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. In the description of the embodiment, the left and right directions in the forward direction of the aircraft are referred to as left and right, respectively, and the forward direction is referred to as forward and the reverse direction is referred to as rear, but this does not limit the configuration of the present invention.

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

As shown in Fig. 1 (oblique view), Fig. 2 (left side view), Fig. 3 (plan view), and Fig. 4 (front view), the self-propelled pesticide sprayer 1 is comprised of a self-propelled vehicle body A, a cabin K provided on the vehicle 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 onto a farm field.

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 the operator to sit in when driving and operating the riding pesticide machine 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.

The steering handle a3, which is erected 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 direction of travel 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.

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

The cabin K forms the passenger compartment by surrounding the driver's seat a2 and its surrounding equipment, 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.

The chemical tank M is a container for storing chemicals. As shown in FIG. 3 in a plan view, the chemical tank M is located at the rear of the cabin K, and is formed in a U-shape 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 fertilizer, pesticides, etc. are dissolved in a solvent (e.g., water), and liquids (e.g., water) containing solids such as fertilizer, pesticides, etc.

(Drug dispersal device)
The pesticide 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.

The spray boom b1 is composed of a center boom b1F located in front of the traveling vehicle body 2 and side booms b1L and b1R located on both sides.

The center boom b1F extends horizontally in the vehicle width direction of the traveling vehicle body 2. In addition, the center boom b1F is provided with multiple nozzles bn spaced apart to spray the medicine in a mist form.

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 pesticide in a mist are arranged at intervals on the side booms b1L, b1R. By rotating the side booms b1L, b1R, the spray boom b1 can be switched between a spraying position in which the entire boom is substantially in a straight line extending in the vehicle width direction (left-right direction) of the traveling body A, and a retracted position in which the side booms b1L, b1R run along both the left and right sides of the traveling body 2. In the spraying position, the spray boom b1 configured in this manner can spray pesticide widely to the left and right of the front of the self-propelled pesticide sprayer 1.

As shown in Figures 2 and 3, the support device b2 is a device that supports the spray 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 open and close the side booms b1L, b1R on both sides by rotating them approximately horizontally. As shown in Figure 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 bottom.

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.

The opening and closing cylinders b24, b24 can be switched between a spraying position extending in the vehicle width direction of the traveling body A and a storage position along both the left and right sides of the traveling body A by extending or retracting. They are connected to the lifting frame b23 and the side booms b1L, b1R, and are configured 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.

(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.

Figure 5 is a circuit diagram showing part of the hydraulic circuit of the self-propelled drug sprayer 1.

As shown in FIG. 5, the vibration damping mechanism of the spray boom b1 is composed of an accumulator U, an on-off valve u1 provided in the hydraulic oil supply/discharge passage that connects the lift cylinder b21 and the accumulator U, and a controller C that can control the opening and closing of the on-off valve u1.

The first and second pumps P1 and 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 and 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. It is connected to a vertical movement switching valve u4 by a second oil passage 102.

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.

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

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 connected, 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 the lifting link b20 is rotated upward accordingly, the lifting frame b23 moves upward, and the spraying boom b1 rises together with the lifting frame relative to the traveling vehicle body 2.

When the vertical movement 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, the lifting link b20 is rotated downward, 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.

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

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

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 and the accumulator U are connected, and thus the piston side chamber b211 of the lifting cylinder b21 is connected to the accumulator U. As a result, hydraulic oil flows between the two, and the accumulator U absorbs pressure fluctuations in the lifting cylinder b21 and exerts a spring action, suppressing vibration of the spray boom b1 and exerting a vibration damping function.

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 raising and lowering the spray boom b1. In particular, the responsiveness refers to the speed at which the lifting and lowering operation of the spray boom b1 starts after the boom raising switch or boom lowering switch is operated.

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 also 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.

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. In other words, it can obtain operation information of the operation panel a6 by the operator. The operation panel a6 is provided with at least a boom-up switch (not shown) that is operated when raising the spray boom b1 relative to the traveling vehicle body A, a boom-down switch that is operated when raising the spray boom b1 relative to the traveling vehicle body A, and a key switch that is operated when turning on the power to the self-propelled drug 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 drug sprayer 1 is that the key switch is in the on state. Therefore, the operator can operate the engine of the self-propelled drug 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. Additionally, controller C is connected to a timer c1 as a timekeeping means, and a relay c2 that detects key switch operation and switches contacts in the circuit.

Figure 6 is an enlarged view of the main front parts of the self-propelled drug sprayer 1.

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 approximate center of the traveling body A serves as a center marker, making it easier for the operator to operate the self-propelled drug sprayer 1 in a straight line. In addition, it becomes easier to visually check for any malfunctions in the accumulator U, improving maintainability.

The on-off valve u1 is housed in the housing X1 arranged below the accumulator U shown in FIG. 6, and the vertical movement switching valve u4 is housed 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 housed in this single housing. In this way, the on-off valve u1 and the vertical movement switching valve u4 are directly mounted integrally, which is easy to assemble, reduces the number of assembly steps, and makes the installation space compact.

The accumulator U, housing X1, and 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 and management 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, housing X1, and housing X2 are attached to this lifting frame b23.

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.

(Opening and closing control of on-off valve)
FIG. 7 is a flowchart showing a control procedure by the controller C.

The controller C controls the on-off valve u1 and the up-down switching valve u4 according to the procedure shown in the flowchart in FIG. 7. Note that, as an initial condition, the key switch is turned off and the on-off valve u1 is switched to the shutoff position u12.

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 open position u11 (step S102). This allows the accumulator U to exert its vibration damping function, suppressing vibration of the spray boom b1. In this way, the on-off valve u1 is opened in conjunction with the operator turning on the key switch, so that 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.

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

In addition, after the controller C controls the on-off valve u1 to be switched to the communication position u11 in step S102, when it 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 cut-off position u12 (step S106). This stops the vibration damping function of the accumulator U 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 external obstacles 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, the on-off valve u1 is switched to the cut-off position u12, which can prevent dust and the like from entering the hydraulic circuit.

Figure 8 is a flow chart showing the procedure by the controller C for the spray boom raising and lowering process (step S104) in Figure 7. When the controller C acquires a signal indicating that the boom up switch 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, it switches the up-down movement switching valve u4 to the extended position u41 and raises the spray boom b1. If the controller C acquires a signal indicating that the boom down switch is turned on, it switches the up-down movement switching valve u4 to the retracted position u42 and lowers the spray boom b1 (step S201).

At the same time, the on-off valve u1 is immediately switched to the shutoff position u12 (step S202). This improves the responsiveness of the subsequent raising and lowering of the spray boom b1.

At this time, the controller C starts the timer c1 at the same time as the spray boom b1 starts to rise and fall, and counts the set time t (step S203). This set time t is preset to a short period of time, for example, about 1 second.

Next, when the set time t has elapsed, the controller C switches the on-off valve u1 to the open position u11 (step S204). That is, the controller C immediately switches the on-off valve u1 to the shutoff position u12 only for a short time immediately after the start of the lifting and lowering operation of the spray boom b1, and switches the on-off valve u1 to the open position u11 during the lifting and lowering operation of the spray boom b1 after the lifting and lowering start. This ensures quick responsiveness during the lifting and lowering operation of the spray boom b1, and furthermore, during the lifting and lowering operation of the spray 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 spray boom b1. As a result, the operation of the spray boom b1 is stabilized, and safety can be improved. That is, according to a conventional configuration in which the opening and closing valve u1 is controlled to 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 extends or shortens, and the spray boom b1 may fall below the stop position and become unstable. However, by controlling the opening and closing valve u1 to 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 stable operation of the spray boom b1 can be achieved. Here, the set time t is preferably set within 0.5 to 3 seconds, and more preferably within 0.5 to 1 second.

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 up-down movement switching valve u4 to switch to the stop position u43 (step S206). This stops the lifting and lowering of the spray boom b1, and the spray boom b1 lifting and lowering process (step S104) in FIG. 7 is completed.

Although not shown in Figures 7 and 8, when the boom up switch or boom down switch is operated continuously for a predetermined time (approximately 0.5 to 1 second), the spray 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 boom down switch. This makes it easy for the operator to stop the operation of the accumulator U in situations where it is not necessary to operate the accumulator U (for example, when the road surface is not very uneven). When the accumulator U is to be operated again, the boom up switch or 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.

In addition, a vibration sensor may be installed on the aircraft, and when the vibration of the aircraft is within a predetermined range and continues for a predetermined time or longer, the on-off valve u1 is automatically closed and the accumulator U is deactivated. However, if the vibration value continues to exceed the predetermined value for at least several times, the on-off valve u1 is automatically opened to activate the accumulator.

The boom up switch and boom down switch are located in positions that allow operation while seated in the driver's seat a2 inside the cabin K, but are also provided outside the cabin K. As shown in FIG. 2, the side boom b1L passes beside the opening and closing door k3L, so 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 raised and lowered by operating the boom up switch or boom down switch provided outside the cabin K.

The side booms b1L, b1R are configured to be able to be raised and lowered independently of the lifting frame b23, and are configured to be able to be raised and lowered 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 hydraulics are 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, using the battery power to drive the electric hydraulic cylinder ES. This makes it easy to get in and out of the cabin K.

Figure 9 is a time chart showing the operation of accumulator U in Figure 5.

In FIG. 9, when the accumulator U is on, the on-off valve u1 is in the communication position u11, and when the accumulator U is off, it is in the 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 (e.g., about 1 second), but it can be adjusted within a predetermined range (e.g., about 0.5 to 3 seconds) by operating the operation panel a6 to realize responsiveness in raising and lowering the spray boom b1 according to the weight of the spray boom b1 and the needs of the operator.

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

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. Alternatively, 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.

Figure 11 is a circuit diagram showing a part of the hydraulic circuit of a self-propelled drug sprayer 1 according to another embodiment. In addition to the hydraulic circuit configuration shown in Figure 5, the hydraulic circuit of the self-propelled drug sprayer 1 according to another embodiment has a fourth oil passage 105 connected to the first constant flow dividing valve u2, and further connects a single-acting roll cylinder switching valve u5, 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.

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 opening/closing valve u7 that can be switched between a communication position u71 that connects the piston side chamber b251 of the single-acting roll cylinder b25 to 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 opening/closing valve u7 to be switched to the communication position u71. This allows the accumulator U2 to exert a vibration suppression function, suppressing vibration in the rolling direction of the lifting frame b23. In addition, when the accumulator U2 is removed for maintenance, the opening/closing valve u7 is switched to the blocking position u72, preventing dust and the like from entering the hydraulic circuit.

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 opening/closing 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 opening/closing valve u7 are housed in a housing X3 shown in FIG. 10.

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's 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 of the center line of the aircraft's traveling direction, the left-right balance of the aircraft is improved.

Also, the on-off valves to the accumulators U, U2 are open, and an indicator light indicating that 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).

A Traveling vehicle body a1 Main frame a2 Driver's seat a3 Steering handle 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/closing cylinder b25 Cylinder for single-acting roll K Cabin k1 Cabin frame k2 Cabin roof k3L, k3R Opening/closing door T Hydraulic oil tank U Accumulator U2 Accumulator for roll P1 First pump P2 Second pump u1 Opening/closing valve u2 First constant flow dividing valve u3 Second constant flow dividing valve u4 Up-down movement switching valve u5 Cylinder switching valve for single-acting roll u6 Relief valve u7 Second opening/closing valve Y Rolling axis

Claims (3)

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 operation 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). The self-propelled drug sprayer according to claim 1, characterized in that a plurality of the accumulators are provided. The self-propelled pesticide sprayer according to claim 1 or 2, characterized in that the on-off valve can be opened and closed by a key switch that starts and stops the engine.