JP7643194B2 - Work vehicles - Google Patents

Description

The present invention relates to a work vehicle equipped with a spraying device such as a boom sprayer.

Conventional work vehicles are equipped with a cabin on the traveling body that serves as the boarding area for the worker, a mirror that allows the rear side of the vehicle to be viewed in the cabin, a chemical tank that stores the chemical solution to be sprayed at the rear of the cabin, and side booms that are deployed on both the left and right sides of the vehicle to spray the chemical solution and can rotate left and right and up and down (Patent Document 1).

JP 2021-29215 A JP 2002-346444 A

However, in conventional work vehicles, the worker is inside the cabin where physical movement is restricted, making it difficult to visually confirm the turning angle of the front wheels located on the underside of the vehicle, and making it difficult to accurately determine the steering direction and amount, which can lead to problems such as shifting of the working position or the front wheels coming into contact with the crops being grown.

When leaning forward to visually check the position of the front wheels, the driving speed is reduced to prevent operational errors, but this reduces work efficiency and causes the worker to become fatigued due to the awkward posture.

In addition, when checking whether the vertical distance between the side boom, which has been rotated and deployed to the side of the machine, and the target to be sprayed with the chemicals is appropriate, the operator must look to the side of the machine. However, this requires the operator to look away from the direction of travel, which means the machine cannot travel in a straight line, and there is a problem that the front wheels may come into contact with the crops being grown.

In addition, because the chemical tank is located at the rear of the cabin, there is a large blind spot that the worker cannot see when looking behind the cabin, making it difficult to check the work situation and even difficult to reverse.

The present invention takes into consideration the issues with conventional work vehicles and aims to provide a work vehicle that provides high visibility around the vehicle and allows workers to easily concentrate on their work.

The invention of claim 1 is a work vehicle having front wheels (2) and rear wheels (3) that can rotate left and right on a traveling body (1), a spraying device (10) that sprays a chemical agent that can rotate around an axis in the vertical direction, and the spraying device (10) that can rotate between a chemical agent spraying position in the left and right direction and a storage position along the vehicle body, a boarding section (200) for a worker to board, and a rear display member (201) that allows the rear of the traveling body (1) to be viewed on the boarding section (200), a front wheel display member (202) that displays the front wheels (2) on its display surface is provided below the rear display member (201), and a spraying device display member (203) that displays the spraying device (10) rotated outward of the vehicle body on its display surface is provided in front of the rear display member (201) and near the rotation fulcrum of the spraying device (10).

The invention of claim 2 is a work vehicle as described in claim 1, characterized in that a liquid chemical tank (9) for storing the liquid chemical to be sprayed by the spraying device (10) is provided at the rear of the riding section (200), a photographing device (205) for photographing the area behind the liquid chemical tank (9), and a rear display member (204) for displaying the video and images photographed by the photographing device (205) is provided at the riding section (200).

The invention of claim 3 is a work vehicle as described in claim 2, characterized in that the rear display member (204) is configured to be switchable to a mirror state that displays a reflected image.

The invention of claim 4 is a work vehicle as described in claim 3, characterized in that the rear display member (204) is provided with a motion detection member (206) that detects the motion of the worker, and a control device (103) is provided that switches the display state of the video or image of the rear display member (204) and the mirror surface state in accordance with the motion detected by the motion detection member (206).

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The invention of claim 1 allows the worker on the riding section (200) to check the state of the front wheel (2) through the front wheel indicator member (202) without moving his/her body, so that the steering direction can be properly maintained and work accuracy can be improved.

In addition, the spraying device display member ( 203 ) allows the spraying device (10) to be confirmed when rotated toward the outside of the machine body without facing the side of the machine body, so that the working height of the spraying device (10) can be properly maintained and the drug can be effectively supplied.

In addition, the rear side of the machine body, the front wheel (2), and the spraying device (10) can be seen at the same time, making it easier to find areas that are not suited to the work situation and preventing a decrease in work accuracy.

In addition to the effects of the invention of claim 1, the invention of claim 2 allows the blind spot caused by the chemical tank (9) to be photographed by the photographing device (205) and confirmed on the rear display member (204) of the boarding section (200), so that appropriate work can be performed according to the situation at the rear of the aircraft.

In addition to the effect of the invention of claim 2, the invention of claim 3 has the advantage that by making the rear display member (204) a mirror surface, it becomes easier to check the situation behind the aircraft, which is different from the area photographed by the photographing device (205), making it easier to reverse driving, etc.

In addition to the effects of the invention of claim 3, the invention of claim 4 makes it possible to switch the display on the rear display member (204) by detecting the operator's movements with the movement detection member (206), eliminating the need for the operator to touch the rear display member (204), and preventing dirt from the operator's hands from adhering to the rear display member (204) and reducing visibility.

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FIG. 1 is a side view of a work vehicle according to an embodiment of the present invention. FIG. 2 is a perspective view of the transmission case of the work vehicle as viewed from the front. FIG. 3 is a perspective view of the transmission case of the work vehicle from the rear. FIG. 2 is a perspective view of the transmission case of the work vehicle as viewed from the rear below. Schematic cross-sectional view of the transmission case. Enlarged image of the clutch inside the transmission case FIG. 2 is a perspective view of the front case of the transmission case as viewed from the front. FIG. 2 is a perspective view of the front case of the transmission case as viewed from the inside. FIG. 2 is a front perspective view of the center case of the transmission case; FIG. 2 is a perspective view of the center case of the transmission case as viewed from the rear. FIG. 2 is a perspective view of the rear case of the transmission case as seen from the inside. FIG. 2 is a perspective view of the rear case of the transmission case as viewed from the rear. FIG. 1 is a front view of a plate of a clutch according to an embodiment of the present invention; Partially enlarged view of the PTO shaft in FIG. (a) Plan view showing front wheel steering during FWS; (b) Plan view showing rear wheel steering during RWS; (c) Plan view showing front and rear wheel steering during 4WS; Block diagram of sensors and corresponding actuators related to each control FIG. 1A is a schematic diagram showing a display screen of the steering state of the front or rear wheels in FWS or RWS; FIG. 1B is a schematic diagram showing a display screen of the steering state of the front and rear wheels in 4WS; FIG. 13 is a schematic diagram showing the display contents of the display device including guide icons; Flowchart showing lighting control of icons indicating steering states of front and rear wheels A flowchart showing the notification control in a state where the front and rear wheels may come into contact with the side pest control boom. A flowchart showing the retraction control of the front boom and the pest control boom in a state in which the front wheels and the rear wheels may come into contact with the side pest control boom. A front view of a work vehicle equipped with a rotatable boom receiver FIG. 1 is a plan view of a work vehicle equipped with a rotatable boom receiver and an extension step; A flowchart showing notification control for preventing the spray pump from running dry when the remaining amount in the chemical tank falls below a predetermined value. A flow chart showing the spray pump stop control when the remaining amount in the chemical tank falls below a predetermined value. Hydraulic circuit diagram that accumulates hydraulic pressure in an accumulator when descending and assists hydraulic pressure increase when ascending. Schematic diagram showing a display device equipped with a safety lamp and a backup lamp. FIG. 1 is a side view of a work vehicle equipped with a cabin and each mirror. Schematic diagram showing the layout of each mirror as seen from inside the cabin Rear view showing the camera mounted on the cabin visor so that the shooting position can be moved up, down, left and right (a) A schematic diagram showing a state in which an image captured by a camera is displayed on a digital mirror. (b) A schematic diagram showing a state in which the digital mirror is made to have a mirror surface and shows the rear of the aircraft. FIG. 1A is a schematic diagram showing a state in which the brightness of the digital mirror is increased by a gesture sensor; FIG. 1B is a schematic diagram showing a state in which the brightness of the digital mirror is decreased by a gesture sensor; A flowchart showing a control for notifying a situation where traveling becomes difficult based on the remaining amount of the liquid in the chemical tank and the forward/rearward inclination of the vehicle.

The following describes in detail an embodiment of the present invention with reference to the drawings. Note that in the embodiment of the present invention, a pest control work vehicle that sprays agricultural chemicals will be used as an example of the work vehicle.

Figure 1 is a schematic left side view of a work vehicle 1. In this specification, the side of the work vehicle 1 in the vehicle's traveling direction is referred to as the front, the opposite side as the rear, the left side in the traveling direction as the left, and the right side in the traveling direction as the right.

As shown in FIG. 1, the work vehicle 1 is a vehicle that sprays pest control liquid, has front wheels 2 and rear wheels 3, and an engine (not shown) is covered by a bonnet 4 provided at the front of the traveling body 1'. Behind the bonnet 4 is a control section 5, which is provided with a steering wheel 6 and a seat 8.

A removable chemical tank 9 that contains chemical liquid is mounted behind the seat 8. The work vehicle 1 also has a hydraulic continuously variable transmission (HST), which is a mechanism that can adjust the forward/reverse direction of travel and the speed of the vehicle, and an engine start restriction device that restricts the starting of the engine.

Support brackets 12a protruding in the left-right direction are provided on both the left and right sides of the front of the vehicle body of the work vehicle 1, and a lifting link 12 composed of upper and lower link bodies is rotatably supported on the left and right support brackets 12a. The upper and lower link bodies of the lifting link 12 are configured to move in conjunction with each other, and a telescopic lifting cylinder 13 is provided on the lower section of the link body of the lifting link 12 so as to connect the lower section of the link body of the lifting link 12 to the support bracket 12a, so that the lifting link 12 can be swung up and down by extending and retracting the lifting cylinder 13.

The lift links 12 also extend to a position in front of the bonnet 4, and the front frame 11 is attached to the front ends of the lift links 12 so as to connect the left and right lift links 12. Therefore, by simultaneously extending and retracting the left and right lift cylinders 13, the front frame 11 can be raised and lowered via the left and right lift links 12 that move up and down.

A pair of left and right pest control booms 10, which serve as an example of a working device and spray chemicals, are attached to both ends of the front frame 11 so that they can rotate about an axis in the vertical direction, and each of the left and right pest control booms 10 is provided with a boom switching cylinder that allows them to be individually deployed and folded in the left and right direction. A number of nozzles 10a are attached to the pest control booms 10, and a front boom 11a equipped with a number of nozzles is attached to the front frame 11. The nozzles 10a of each pest control boom 10 and each nozzle of the front boom 11a are configured to receive a supply of chemicals from a chemical tank 9 and spray the chemicals in a spray form. Note that the right pest control boom 10 is omitted from Figure 1.

The state in which the pest control boom 10 is folded and aligned with the vehicle body is called the storage position, and the state in which the pest control boom 10 is unfolded and extended to the left and right is called the chemical spraying position. In the storage position, the pest control boom 10 can be maintained facing diagonally upward toward the rear of the vehicle body by placing the pest control boom 10 on the boom receivers 15 provided on both the left and right sides of the work vehicle 1.

Figure 2 is a perspective view of the transmission case 20 mounted on the work vehicle of this embodiment, seen from the front to the rear, Figure 3 is a perspective view of the transmission case 20, seen from the rear to the front, and Figure 4 is a perspective view of the transmission case 20 of Figure 3, seen from the bottom side.

2, 3, and 4, 21 is the front case, 22 is the center case, 22a is the bottom of the center case 22, and 23 is the rear case. Furthermore, 24 is the input shaft of the transmission force from the engine, and 25 and 26 are the first and second hydraulic pumps. Furthermore, 27 is a shaft for turning the clutch on and off, which will be described later, 28 is a rear lift valve, and 29 is the driving output shaft of the front wheels 2. Furthermore, 30 is a hydraulic continuously variable transmission (HST), and 31 is a clutch lubrication hole. Furthermore, 32 is a PTO shaft for a working device such as a boom sprayer, 33 is a live PTO output shaft (additional transmission shaft), which will be described later, 34 is a vehicle speed sensor, 35 is a drain, 36 is a sub-speed shaft, 37 is a breather, and 38 is a driving output shaft that transmits the driving force to drive the rear wheels 3.

The inside of the transmission case 20 has a structure as shown in Figures 5 and 6. Figure 5 is a simplified cross-sectional view of the entire case, and Figure 6 is an enlarged view focusing on the clutch 55.

First, the front case 21 will be mainly described. Fig. 7 is a perspective view of the front case 21 as seen from the front side, and Fig. 8 is a perspective view of the front case 21 as seen from the rear side. Here, the ball bearings of the bearings are omitted in Figs. 7 and 8. The input shaft 24 is held by the input bearing 21a. A gear 40 is connected to the rear end of the input shaft 24. A gear 41 fixed to a clutch drive shaft 42 meshes with the gear 40. The front end of the clutch drive shaft 42 is supported by a clutch front bearing 43 formed in the front case 21. Here, 55 is a clutch.

Furthermore, the gear 41 meshes with the gear 44 located below it, and this gear 44 is fixed to a gear pump drive shaft 45 that drives the first hydraulic pump 25, and a gear pump bearing 46 that serves as a bearing for this gear pump drive shaft 45 is formed in the front case 21.

On the other hand, above the gear 40, a gear 47 attached to a shaft 48 meshes, and the tip of the shaft 48 is supported by a bearing 49 formed on the front case 21. Furthermore, the rear end of the shaft 48 is supported by a bearing 50a provided on a part of the bearing plate portion 50 attached to the center case 22 side. A gear 51 is attached near the center of the shaft 48, and a gear 52 meshes with the gear 51, and the gear 52 is fixed to the above-mentioned live PTO output shaft 33. The front end of the live PTO output shaft 33 is supported by a bearing 54 formed on the front case 21, and the rear end is journaled by a bearing 50b formed on the bearing plate portion 50, and protrudes rearward to be usable as a live PTO output shaft.

When the driving force of the engine is input from the input shaft 24, the gear 40 rotates. This rotation causes the meshed gear 47 to rotate, which in turn rotates the shaft 48. The rotation of the shaft 48 causes the gear 51 to rotate, which in turn rotates the meshed gear 52.

As a result, the live PTO output shaft 33 fixed to the gear 52 rotates, and the driving force from the engine is output to the outside. This driving force is output from the upstream side (right side) of the clutch 55, so it is not affected by the clutch 55 being on or off, and can be output as long as the engine is running.

Gear 40 also meshes with gear 41, which is fixed to clutch drive shaft 42, so the driving force of the engine is also transmitted from input shaft 24 to clutch drive shaft 42. Clutch drive shaft 42 is connected to clutch 55. Therefore, the driving force transmitted to clutch drive shaft 42 depends on whether clutch 55 is engaged or disengaged.

Furthermore, gear 41 meshes with gear 44, and the driving force of the engine is also transmitted from the input shaft 24 to the gear pump drive shaft 45 to which gear 44 is fixed. The rotation of this gear pump drive shaft 45 drives the first hydraulic pump 25. Oil is pumped by the first hydraulic pump 25 to the working hydraulic system. The second hydraulic pump 26 attached to the front case 21 is also driven by a similar mechanism.

Next, the central case 22 and the rear case 23 will be described. As shown in Figures 9 and 10, the central case 22 is detachable from the front case 21 and rear case 23 by a bolt mechanism. As shown in Figure 5, A indicates the boundary surface between the front case 21 and the central case 22, and B indicates the boundary surface between the central case 22 and the rear case 23. The central case 22 is fixed to the frame of the traveling body 1' of the work vehicle 1 by a connecting part 53 (see Figure 10). Figure 11 is a perspective view of the rear case 23 seen from the inside, and Figure 12 is a perspective view seen from the rear outside.

Inside the central case 22, the above-mentioned bearing plate portion 50 is formed at the front position, and the clutch bearing plate portion 57 is formed at the central position.

A clutch 55 is disposed between the front bearing plate 50 and the clutch bearing plate 57, and the clutch drive shaft 42 is journaled on the bearing 60 of the clutch bearing plate 57 via the clutch 55. Furthermore, the rear part of the clutch drive shaft 42 passes through a hole 61 (see FIG. 10) in the bearing 60 and is journaled on a clutch drive shaft bearing 62 in the rear case 23.

The HST drive shaft is supported by the rear case 23, so it is either cantilevered by the rear case 23 or fixed to the HST itself.

In addition, since the drive shaft is long from front to rear, it is supported by the front case 21, the center case 22, and the rear case 23.

Furthermore, as shown in FIG. 5, a transmission gear 70 is fixed to the clutch drive shaft 42, and the transmission gear 70 meshes with a gear 71 (loose-fit gear) that is freely rotatably attached to the shaft of the work device PTO shaft 32.

The rotation of the gear 71 is transmitted to the PTO shaft 32 by the rotation of the clutch drive shaft 42 through a mechanism described below. Therefore, the rotation of the work device PTO shaft 32 is determined by whether the clutch 55 is engaged or disengaged. 32a is a PTO bearing provided in the rear case 23.

On the other hand, a gear 63 is further attached to the clutch drive shaft 42, and this gear 63 meshes with an HST input gear 64. Also, the HST output gear 65 is connected to the front wheel drive output shaft 29 and the rear wheel drive output shaft 38 via three gear mechanisms 66, 67, and 68. In FIG. 7, 29a is a bearing for the front wheel drive output shaft 29. Therefore, the output changed in speed by the HST 30 is transmitted to the drive output shafts 29 and 38. Here, 30a is the HST input side, and 30b is the HST output side. Also, 72 and 73 are the HST input bearing and the HST output bearing, respectively.

In this way, by dividing the transmission case 20 into front, center, and rear sections and fixing the center case 22 to the frame of the running body 1' of the work vehicle 1 (connection part 53), maintenance work inside the case can be performed without removing the entire transmission case 20 from the vehicle body.

Next, the clutch 55 in this embodiment has a wet structure rather than a so-called dry structure. That is, as shown in Figures 5 and 6, the clutch drive shaft 42 is supported at both ends (43, 62) by the front case 21 and the rear case 23, and an oil passage is formed between the shaft and the support. Lubricating oil is supplied from the clutch lubrication hole 31. The lubricating oil returns the hydraulic pressure return (working hydraulic system) of the pest control machine to the oil passage of the clutch drive shaft 42.

The clutch 55 is configured by mounting multiple clutch plates 55b inside a clutch case 55a, and by mounting the clutch case 55a on the clutch drive shaft 42. Furthermore, the clutch drive shaft 42 has a flow path for hydraulic oil, and hydraulic oil can be supplied to the inner circumference side of the clutch plates 55b. Furthermore, the clutch case 55a is formed with a return hole portion that returns hydraulic oil that has entered the clutch case 55a to the hydraulic circuit. Note that Figure 13 shows the clutch plate 55b, which has a communication hole 92 formed from the inner circumference to the outer circumference as shown by arrow C.

Since the clutch 55 has this structure, hydraulic oil is supplied from the flow passage of the clutch drive shaft into the clutch case 55a, preventing the clutch plate 55b from burning out and becoming immobile, so travel transmission and work transmission can be reliably switched on and off.

Furthermore, by forming a return hole in the clutch case 55a, the hydraulic oil that has entered the clutch case 55a can be returned to the transmission case 20, preventing an increase in internal pressure and a shortage of hydraulic oil.

In addition, by forming the communication hole 92, the hydraulic oil that has entered between the clutch plate 55b and the clutch case 55a can be moved outside the clutch case 55a, preventing problems caused by hydraulic oil that is no longer able to return to the flow path becoming stale.

In other words, the communication hole 92 is formed by penetrating the clutch plate 55b toward the outer periphery at one or more points, so that when the hydraulic oil stored in the transmission case 20 is immersed in the hydraulic oil, the hydraulic oil can enter the inside of the communication hole 92 from that portion and permeate the inside of the clutch case 55a (this phenomenon occurs particularly when the vehicle is stopped). Also, when the centrifugal force caused by the rotation of the clutch drive shaft 42 scatters the hydraulic oil that has entered the communication hole 92 to the outside of the clutch case 55a, the hydraulic oil is sent into the transmission case 20. In other words, the configuration allows the hydraulic oil to enter the inside and to be discharged to the outside.
FIG. 14 is a partially enlarged view of FIG. 5, focusing on a PTO shaft 32 for a work device such as a boom sprayer.

As described above, a speed change gear 70 is fixed to the clutch drive shaft 42, and this speed change gear 70 meshes with a gear 71 (loose-fit gear) that is freely rotatably attached to the shaft of the work device PTO shaft 32. This gear 71 meshes with a first counter gear 75 fixed to a counter shaft 76. Another second counter gear 77 is fixed to this counter shaft 76, and this second counter gear 77 meshes with a gear 78 fixed to the shaft of the PTO shaft 32. Note that 71a is a grooved washer.

Therefore, the rotation of the clutch drive shaft 42 rotates the gear 70, which in turn is transmitted to the loose-fit gear 71, which in turn is transmitted to the first counter gear 75, which in turn is transmitted to the counter shaft 76, which in turn is transmitted to the second counter gear 77, which in turn is transmitted to the gear 78, and as a result, the rotation is transmitted to the PTO shaft 32, which then rotates.

On the other hand, 90 is a lubricating oil pipe that returns and discharges hydraulic oil from the working hydraulic system into the transmission case 20. 79 is an outlet 79 of the lubricating oil pipe 90 provided in the rear case 23. The outlet 79 of the lubricating oil pipe 90 is located above the transmission mechanism for the work driving force, which is located on the upper side inside the transmission case 20. Here, the transmission mechanism is a mechanism for transmitting the driving force to the working mechanism, such as the PTO shaft 32, which is an example of the work transmission shaft of the present invention.

With this structure, the hydraulic oil is discharged from the upper side of the transmission case 20, so that the upper transmission mechanism, which is prone to internal lubricating oil shortages, can be reliably lubricated, thereby reducing wear and seizure and preventing a decrease in the durability of the transmission case 20.
In this case, the transmission case 20 itself also serves as an oil tank. The first hydraulic pump 25 pumps the oil from this oil tank as hydraulic oil back to the drive cylinder.

Furthermore, a diffusion member that receives the hydraulic oil discharged from the discharge port 79 and diffuses it to the surroundings is rotatably attached to this PTO shaft (work transmission shaft) 32. An example of a diffusion member of the present invention is the freely rotating gear 71 described above.

By rotating the gear 71 of the diffusion member attached to the PTO shaft 32, the hydraulic oil can be diffused over a wide area by centrifugal force, which further prevents wear and seizure caused by a lack of hydraulic oil.

In addition, the gear 71, which is the diffusion member, is formed with oil passage holes 91 through which the hydraulic oil can enter the interior. This makes it easier to diffuse the hydraulic oil over a wide range in directions other than the rotational direction. It is preferable to provide multiple oil passage holes 91. For example, four holes are provided at 90 degrees around the axis. This also has the effect of allowing the lubricating oil to flow into the inside of the gear 71.

The gear 71, which is the diffusion member, rotates in a fixed direction, so this alone tends to cause the hydraulic oil to be scattered slightly biased in the direction of rotation. However, by forming an oil passage hole 911 penetrating the gear 71, the hydraulic oil that has entered the interior from the outlet 79 is released by centrifugal force at a position other than that where it is repelled by the wing part of the gear 71 (corresponding to the gear teeth), and the hydraulic oil is more likely to be diffused downstream in the direction of rotation.

The lubricating oil pipe 90 is attached to the front or rear of the transmission case 20, and an orifice is formed at the outlet 79 of the lubricating oil pipe 90, which faces the inside of the transmission case 20. This allows the hydraulic oil to be dispersed over a greater distance.

As described above, the hydraulic pressure return (working hydraulic system) from the pest control machine back into the transmission case 20 includes a system that returns from the clutch lubrication hole 31 via the clutch 55, and a system that returns from the outlet 79 of the lubrication oil supply pipe 90 in the rear case 23 of the transmission case 20. In addition, there is also a system in which the hydraulic oil discharged from the lift valve and the lower link cylinder returns into the transmission case 20 through the main valve provided on the side of the transmission case 20.

As shown in FIG. 15(c), the left and right front wheels 2, 2 and rear wheels 3, 3 of the work vehicle 1 are configured to be switchable to a so-called four-wheel steering (4WS) state in which the steering angles of the left and right front wheels 2, 2 and the rear wheels 3, 3 are switched in conjunction with each other by steering the steering wheel 6 in order to reduce the space required for turning at the edge of a field.

As shown in Figures 15(a) and 15(b), when working in a field or traveling on a road, it is possible to switch from four-wheel steering to front-wheel steering (FWS) in order to change only the steering angle of the left and right front wheels 2, 2 to control the direction of travel in the same way as an automobile, and it is also possible to switch to rear-wheel steering (RWS), which changes only the steering angle of the rear wheels 3, 3 by operating the steering wheel 6 in order to prevent the front wheels 2, 2 from contacting the crops or the ridges when aligning the vehicle with the ridges.

The above-mentioned 4WS, FWS and RWS switching is performed by operating the steering changeover switch provided on the control unit 5, or by activating the automatic changeover mode and satisfying certain operating conditions.

In either the manual or automatic switching described above, in order to prevent unexpected driving after switching and to prevent contact with the crops being cultivated, it is desirable to set the front wheels 2, 2 and rear wheels 3, 3 to the center steering position (neutral position), in other words, a position that moves straight forward or backward.

However, in fields where riding tillers are used, the length of the crop stems and leaves is longer than the vertical length of the front wheels 2, 2 and rear wheels 3, 3, and the operator sitting in the seat 8 often has difficulty visually checking the steering angle of the front wheels 2, 2 and rear wheels 3, 3. In particular, the rear wheels 3, 3 are located lower than the chemical tank 9, making them even more difficult to see. In addition, in models equipped with a cabin 200 that covers the seat 8 and steering unit 5 as shown in Figure , the range in which the operator can move his or her body is limited, further reducing visibility of the front wheels 2, 2 and rear wheels 3, 3.

This makes it difficult for the operator to determine how far to turn the steering wheel 6 to the left or right, and it takes time to steer the vehicle. Furthermore, if the steering direction is incorrect, the front wheels 2, 2 or the rear wheels 3, 3 may come into contact with the crops being cultivated, damaging them and causing poor growth and a decline in quality.

To solve this problem, as shown in Figure 16, a steering display device 100 is provided on the control unit 5 or in a position visible to the operator, a steering detection sensor 101 is provided to detect whether the current steering mode is 4WS, FWS, or RWS, and a handle potentiometer 102 is provided to detect the amount and direction of operation of the steering wheel 6.

The control device 103 installed on the traveling vehicle body 1 displays the current turning direction SW of the front wheels 2, 2 and the rear wheels 3, 3 and the rough turning angle SA on the steering display device 100 based on the steering mode detected by the steering detection sensor 101 and the operation amount and operation direction of the steering wheel 6 detected by the handle potentiometer 102.

As shown in Figures 17(a) and (b), the display of the turning direction SW and turning angle SA should be shown as images of tires going straight or tilted left and right, so that the operator can intuitively grasp the state of the front wheels 2,2 and the rear wheels 3,3 and easily consider the direction and amount of operation of the steering wheel 6. However, as shown in Figure 18, the turning direction SW may be displayed as text such as "right", "left", and "center (straight)", and the turning angle SA may be displayed as a number. Depending on the user, it may be easier to consider the direction and amount of operation of the steering wheel 6 when text or numbers are used, so the display content of the steering display device 100 may be configured to be changeable by the operator.

In addition, when the front wheels 2, 2 and rear wheels 3, 3 are not in a straight-ahead position and are at a turning angle SA that is determined to be turning to the right or left, a guide icon SI such as letters or an arrow may be displayed to indicate to which side the operator should steer the steering wheel 6.

The steering display device 100 may also display whether the current steering mode is 4WS, FWS, or RWS based on detection by the steering detection sensor 101.

This steering display device 100 is preferably embedded in the steering unit 5 or is detachably installed, but it may also be paired with an information terminal capable of communication such as a tablet and use an installed application to sequentially display the turning direction SW and turning angle SA of the front wheels 2, 2 and the rear wheels 3, 3. In this case, it is preferable to provide a terminal mounting stand (not shown) on the traveling vehicle body 1 so that the operator in the seat 8 can place the information terminal in a position that is easy to see.

Alternatively, the steering display device 100 can be configured by installing the same application as the information terminal described above on a wearable terminal worn by the worker, such as smart glasses or a retinal projection display.

The steering mode switching patterns are explained below.

As shown in FIG. 19, when the steering detection sensor 101 detects the FWS, the control device 103 calculates the amount and direction of operation of the steering wheel 6 based on the detection value of the handle potentiometer 102, and displays the turning state of the front wheels 2, 2 on the steering display device 100.

At this time, when the detection value of the handle potentiometer 102 is in the straight-ahead position, that is, within a predetermined range from 0 in the positive and negative directions (0±predetermined value), an icon is displayed indicating that the front wheels 2, 2 are not turned left or right. At the same time, a display indicating that the steering mode can be switched (such as "Switch OK") may be displayed on the steering display device 100. If the control configuration is such that the steering mode does not switch even if the operator presses the steering changeover switch when the above conditions are not met, the front wheels 2, 2 and rear wheels 3, 3 can be prevented from coming into contact with and damaging the crops.

On the other hand, when the detection value of the handle potentiometer 102 indicates that the wheel is turned to the left or right, the steering display device 100 shows the front wheels 2, 2 in a turned state linked to the operation of the steering wheel 6. If the display of the tilted front wheels 2, 2 is configured to select one from a number of different tilt angles that approximates the detection value of the handle potentiometer 102, the operator can easily grasp the magnitude of the steering amount.

The above is when the steering mode is FWS. When the steering mode is RWS, the front wheels 2, 2 are replaced with the rear wheels 3, 3. Note that the rear wheels 3, 3 in FWS and the front wheels 2, 2 in RWS are not displayed on the steering display device 100 or are always displayed in a straight ahead position.

On the other hand, when the vehicle is in 4WS mode, both the front wheels 2, 2 and the rear wheels 3, 3 are displayed simultaneously, and the front wheels 2, 2 and the rear wheels 3, 3 with different inclination angles are displayed according to the detection value of the handlebar potentiometer 102.

In a 4WS, when the steering wheel 6 is operated, the turning angle SA of one of the front wheels 2, 2 and the rear wheels 3, 3 increases in the positive direction and the turning angle SA of the other increases in the negative direction, and both the front and rear wheels are 0 only in the straight-ahead position. The absolute value of the turning angle SA is approximately the same in positions other than the straight-ahead position.

The above configuration allows the operator to consider the direction and amount of operation of the steering wheel 6 by looking at the steering display device 100 without visually checking the front wheels 2, 2 or the rear wheels 3, 3, or both, so there is no need for the operator to interrupt his work to visually check the front wheels 2, 2 and the rear wheels 3, 3, and unnecessary time is prevented from being wasted when switching steering modes.

In addition, because it is possible to prevent the steering wheel 6 from being steered in the wrong direction, it is possible to prevent the front wheels 2, 2 and rear wheels 3, 3 from coming into contact with the crops and damaging them, which can lead to poor growth and reduced quality.

The ride-on management machine in this case sprays pesticides from a front boom 11a that is positioned in front of the traveling vehicle body 1 and left and right pest control booms 10. The front boom 11a is adjustable in height, and the left and right pest control booms 10 can rotate up and down and left and right using the left and right sides of the front boom 11a as bases.

This allows the front boom 11a to be raised and lowered to adjust the spray height of the pesticide according to the type of crop, growth conditions, and other working conditions, making it possible to supply the appropriate amount of pesticide to the crops, preventing crop yields from being affected by pests and diseases due to a lack of pesticide, and preventing a decline in the commercial value of the crops.

The above-mentioned shortage of pesticide occurs when the vertical distance between the front boom 11a and the left and right pest control booms 10 and the crop is too wide, resulting in areas where the pesticide is not sprayed due to the effects of the wind. On the other hand, if the vertical distance is made too narrow in order to reduce the effects of the wind, the pesticide will be sprayed unevenly (for example, most of the pesticide will be received on the stems and leaves, and almost none will be sprayed on the surrounding ground), causing pests and diseases to occur in areas where the pesticide is difficult to reach, resulting in problems such as reduced yields and reduced commercial value.

To address this issue, it is necessary to properly adjust the vertical positions of the front boom 11a and the left and right side booms 10 as described above to spray the pesticide as evenly as possible.

When spraying chemicals on crops with relatively short stems and leaves, such as radishes and carrots, it is necessary to move the front boom 11a significantly downward, and at this time the front boom 11a and the pest control boom 10 are positioned within the vertical width of the front wheels 2 and rear wheels 3. When the left and right pest control booms 10 are spread out on both sides of the machine, i.e., lined up in a straight line on the left and right of the front boom 11a, no problems will occur as long as the vertical position adjustment is not incorrect. However, near the edge of the field, especially when one of the pest control booms 10 protrudes outside the field in its current position, if one of the booms is rotated toward the rear of the machine and placed in a position approximately parallel to the traveling vehicle body 1, the following problems may occur.

The pest control boom 10, which is oriented approximately parallel to the traveling vehicle body 1, is located within the rotation range of the front wheels 2 and rear wheels 3. If it is located to the side within the vertical width of the front wheels 2 and rear wheels 3, there is a risk of it coming into contact and being damaged when the front wheels 2 or rear wheels 3 are rotated. This problem is likely to occur when turning while raising the front boom 11a at the end of the working row.

To prevent this problem from occurring, as shown in Figures 1, 16 and 20, an up-down link sensor 105 is provided on the up-down link 104 of the front boom 11a to enable detection of the up-down height of the front boom 11a, and a boom potentiometer 106 is provided on the front-to-back rotation axis (not shown) in the up-down direction of the machine body of the left and right pest control booms 10, respectively, to enable detection of the front-to-back position of the pest control booms 10.

Then, when the control device 103 determines from the detection value of the up/down link sensor 105 that the front boom 11a is below a predetermined height and from the detection value of the boom potentiometer 106 that the pest control boom 10 is positioned approximately parallel to the side of the traveling vehicle body 1, it activates an alarm device 107 such as a buzzer 107a or a lamp 107b when the handle potentiometer 102 detects a change in the steering angle due to the steering operation of the steering handle 6, and notifies the operator that the front wheel 2 or rear wheel 3 being steered may come into contact with and damage the pest control boom 10 on the side. This alarm device 107 is provided in either the control unit 5, a detachable information terminal such as a tablet, or a wearable terminal, or in some or all of multiple terminals.

This allows the pest control boom 10 to turn while positioned within the vertical width of the front wheels 2 and rear wheels 3, preventing the pest control boom 10 from bending or folding, thus preventing interruptions to work and avoiding the time, effort, and expense required to replace the pest control boom 10.

In addition, when the vertical height detected by the vertical link sensor 105 falls below a predetermined height, the lamp 107b may be turned on or a warning icon (not shown) may be displayed regardless of the position of the pest control boom 10, to notify the operator in advance that the pest control boom 10 may be positioned within the vertical width of the front wheels 2 and rear wheels 3.

This allows the operator to recognize when the pest control boom 10 is at a height where it may be damaged depending on the operation, further reducing the possibility of the pest control boom 10 being damaged.

Even if the rotation position of the pest control boom 10 in the left-right direction (forward-rear direction) of the machine body is the closest to the traveling vehicle body 1, when it is rotated upward to an angle perpendicular or nearly perpendicular to the field scene, it will not come into contact with the rear wheels 3, 3 or the front wheels 2, 2 regardless of the vertical position of the front boom 11a. Therefore, a vertical rotation sensor (not shown) that detects the vertical rotation amount of the pest control boom 10 may be provided, and if the detected vertical rotation amount is equal to or greater than a predetermined angle, the alarm device 107 may not be activated.

In addition, if the buzzer 107a is set not to operate even if the handle potentiometer 102 detects the operation of the steering handle 6 when the detection value of the boom potentiometer 106 is a value that determines that the pest control boom 10 will not come into contact with the front wheel 2 or rear wheel 3, the generation of unnecessary noise can be prevented.

Depending on the work environment, the worker may not notice the alarm generated by the activation of the alarm device 107, and may panic and make erroneous operations, causing the front wheels 2 and rear wheels 3 to continue to rotate. Therefore, as shown in FIG. 21, when the alarm device 107 is activated and a change in the steering angle of the handle potentiometer 102 continues to be detected, the amount of oil sent from the oil pump (not shown) may be increased, the amount of hydraulic oil supplied to the lifting cylinder 108 of the vertical movement link 104 may be increased, and the lifting speed of the front boom 11a may be increased.

This allows the pest control boom 10 to be retracted above the upper ends of the front and rear wheels 2 and 3 before the front and rear wheels 2 and 3 rotate and come into contact with the pest control boom 10, thereby preventing damage to the pest control boom 10.

In addition, in order to reduce the force required to operate the steering handle 6, in vehicles equipped with a hydraulic power steering mechanism, the supply and discharge of hydraulic oil to the power steering mechanism may be stopped, making it difficult for the operator to operate the steering handle 6.

When not in use, the pest control boom 10 must be rotated toward the rear of the machine and rotated downward to the stored position; however, if it is rotated downward too far, the pest control boom 10 will be in a position where it may come into contact with the front wheels 2 and rear wheels 3. Therefore, as mentioned above, the traveling vehicle body 1 is provided with boom receivers 15 on each side that come into contact with the pest control boom 10 at predetermined positions and support the pest control boom 10 in a rear-upward tilted position.

As a result, the pest control boom 10 is positioned higher on the vehicle body than the upper ends of the front and rear wheels 2 and 3, preventing the front and rear wheels 2 and 3 from coming into contact with and damaging the pest control boom 10 when turning, etc.

In addition, when in the stored position, the boom receiver 15 surrounds the bottom and both the left and right sides of the pest control boom 10, so even if the pest control boom 10 vibrates while traveling, it is unlikely to fall off the boom receiver 15, and the long pest control boom 10 is prevented from swinging and colliding with the surrounding area, resulting in damage.

The ride-on management machine is used for tasks other than spraying pesticides using the chemical tank 9, front boom 11a, and left and right pest control booms 10, and the above-mentioned components are removed depending on the task. However, the left and right boom receivers 15 are attached in a position that protrudes from the running body 1 to the sides of the machine, which can cause problems such as interference when attaching components used for other tasks or hindering attachment and detachment work. As they are firmly attached to the running body 1 to ensure strength, the boom receivers 15 can be removed, but this requires extra time and effort.

The boom receiver 15 is bent upward at the outer end of the machine body, and has a U-shaped receiver at its upper end that receives the pest control boom 10 when viewed from the front and rear.

To solve this problem, as shown in Figure 22, the boom receiver 15 is attached to a pivot boss 15a that extends in the left-right direction of the machine body so that it can rotate back and forth when viewed from the side.

As a result, when not needed, the boom receiver 15 can be rotated, for example 90 degrees, to the front or rear of the machine body to prevent it from protruding upward, preventing it from interfering with the attachment of other work components or interfering with operation.

When the front boom 11a and the left and right pest control booms 10 are removed, the front of the left and right boom receivers 15 are open, so the left and right boom receivers 15 can rotate at least about 90 degrees forward of the machine. To make effective use of this space and make it easier for the worker to move and work at a distance from the ground, a plate-shaped extension step 109 is attached to the space located on the inside of the machine body relative to the outer end of the boom receiver 15.

In order to ensure the strength required to withstand the weight of workers and materials, the extension step 109 is desirably formed into a plate shape by combining multiple thick or thin metal plates, or by cutting a metal plate into a lattice shape, or by crossing multiple rods inside a frame to form a lattice shape.

If strength is a priority, the extension step 109 can be attached to the boom receiver 15 by welding, but it can be made detachable so that it can be moved to another location when not needed, which improves convenience.

In the case of a detachable type, the shape of the extension step 109 should be such that it can be attached to the boom receiver 15, but when welding, the vertical length of the extension step 109 should be limited to below the receiver in order to prevent the pest control boom 10 from coming into contact with the U-shaped receiver before it reaches it.

This allows workers to stand on the extension step 109 to carry out their work, allowing them to get closer to the inside of the bonnet 4, which is located on the upper side of the traveling vehicle body 1, and perform maintenance and other work, thereby improving work efficiency.

The chemical solution stored in the chemical solution tank 9 is sent to the front boom 11a and the left and right pest control booms 10 by the spray pump 9a, which can be operated regardless of whether the clutch 55 is on or off via the live PTO output shaft 33, and sprayed onto the field. However, if the operator continues to operate the tank 9 without realizing that the chemical solution stored in the tank 9 has run out, the tank will run dry.

While the liquid is being pumped out, the liquid acts as a coolant to suppress the frictional heat caused by the operation of the spray pump 9a, but once the liquid runs out, the pump will heat up and there is a risk of damage to components such as bearings.

In addition, if after a period of dry operation, the chemical solution is poured into the chemical solution tank 9 without allowing time for cooling and spraying of the chemical is started, the spray pump 9a will be cooled suddenly by the chemical solution, and the structural material of the spray pump 9a may deteriorate, reducing its durability or even crack and break, resulting in a heat shock.

To prevent this problem, as shown in Figures 16 and 24, a chemical remaining amount sensor 111 is provided inside the chemical tank 9 to detect when the remaining amount of chemical falls below a certain level, and a rotation sensor 112 is provided to detect the rotation of the live PTO output shaft 33.

The control device 103 is configured to activate the alarm device 107 to notify the operator that the spray pump 9a is running dry when the remaining chemical sensor 111 detects that the chemical has run out or that the remaining amount of chemical is very low, and the rotation sensor 112 detects the rotation of the live PTO output shaft 33.

This allows the operator to recognize early on that the spray pump 9a may be running dry, preventing a decrease in durability or damage to the spray pump 9a.

In addition, it is possible to prevent sections from being left unsprayed due to driving with insufficient chemical solution, thereby preventing poor growth and reduced quality of crops due to a lack of chemical solution.

The chemical solution remaining sensor 111 is configured to include a float that can float near the surface of the liquid, a suspension wire connected to the float, and a wire that is energized when the weight of the float pulls the wire downward and puts it in a taut state, or detects that the chemical solution has run out or has been reduced to a very low level by cutting off the power supply. The chemical solution remaining sensor 111 is configured to be suspended from the inner wall of the chemical solution tank 9 or from a removable lid toward the bottom of the chemical solution tank 9.

As a result, while there is sufficient liquid, the float floats near the surface of the liquid, slackening the suspension wire, so that running out of liquid cannot be detected. On the other hand, when there is very little liquid left or it is completely gone, the weight of the float pulls the suspension wire downward, allowing current to flow or not flow, making it possible to detect a run out or reduction in liquid.

However, if the spraying operation of the chemical solution is stopped, i.e., if the power transmission to the live PTO output shaft 33 is cut off and the spray pump 9a is not operating, damage or heating due to dry running will not occur. Therefore, by only issuing an alarm when the rotation sensor 112 detects the rotation of the live PTO output shaft 33, the alarm device 107 can be prevented from continuing to operate even when the vehicle is moving and not working, which prevents noise problems from occurring.

As shown in Figures 16 and 25, a spray clutch 120 may be provided between the live PTO output shaft 33 and the spray pump 9a, and a spray solenoid 121 may be provided to switch the spray clutch 120 on and off. When both the chemical remaining amount sensor 111 and the rotation sensor 112 are in the detection state, the spray solenoid 121 is activated to operate the spray clutch 120, cutting off the transmission to the spray pump 9a, and the alarm device 107 is activated to notify the user that chemical needs to be replenished.

This configuration reliably prevents damage to the spray pump 9a. In addition, the live PTO output shaft 33 is designed to move so that the spray pump 9a can be operated even when the clutch 55 is disengaged, so there are no particular problems with idling it.

The front boom 11a and pest control boom 10 are raised and lowered during operation in accordance with turning, the position in the field, the growth conditions of the crops, etc., but due to their weight and length, the time required for the raising operation tends to be longer than the lowering operation.

This causes problems such as an inability to increase the turning speed, which increases the time required for work, and a delay in ascent when adjusting the vertical spacing to match the height of the crop, which causes the pesticide to be applied unevenly. In addition, a slow rise when avoiding an obstacle can cause the pest control boom 10 to come into contact with the obstacle and be damaged.

To address this issue, one possible solution is to store hydraulic pressure generated during the lowering operation and release it during the ascent, thereby increasing the hydraulic oil delivery speed and reducing the time required for the ascent operation.

As a specific example of this configuration, a pressure accumulator solenoid valve 115 is provided upstream of the oil passageway from the check valve 114 that controls the flow rate of hydraulic oil when the pest control lifting cylinder 113 that raises and lowers the front boom 11a extends and retracts. The pressure accumulator solenoid valve 115 opens to draw in a portion of the hydraulic oil when the pest control lifting cylinder 113 descends, and an accumulator 116 is provided to hold the hydraulic pressure of the hydraulic oil drawn in when the pressure accumulator solenoid valve 115 opens. In addition, a hydraulic pressure adjustment valve 117 is provided that opens when the hydraulic pressure falls below a certain level when the pest control lifting cylinder 113 ascends, releasing the hydraulic oil held in the accumulator 116 to increase the hydraulic pressure in the oil passageway.

During the lowering operation, the hydraulic oil that passes through the check valve 114 and moves upstream of the oil passage is held and stored in the accumulator 116 until it is needed, so that when the ascent operation is performed, the increase in hydraulic pressure can be accelerated by the amount of pressure stored in the accumulator 116.

As a result, the front boom 11a and the pest control boom 10 can move upwards quickly, so the spray height of the pesticide on the crops can be kept appropriate, preventing uneven pesticide supply, and obstacles can be avoided to prevent damage.

The steering section 5 is provided with a meter panel 5a that indicates the driving speed, current operation settings, occurrence of abnormalities, etc., and this meter panel 5a is provided with a safety lamp 118 that indicates whether the safety mode is in effect, which refuses to accept operation of each device until the engine output and hydraulic system stabilize after the key is turned on, as shown in FIG. 27, and a backup lamp 9 that indicates whether a backup mode is in effect, which automatically raises the working device (not shown) attached to the rear of the traveling body 1 to a specified height when reverse operation is performed with the working device attached, and automatically returns it to the working height before it was raised when switching to forward.

Depending on whether the safety lamp 118 is lit or not, the operator can visually determine whether it is OK to start operating each part of the machine, so work can be started with sufficient engine output for driving and transmission to each work device, and with the hydraulic system operating according to the control design, improving work efficiency and accuracy.

In addition, since there was no part equivalent to the safety lamp 118 in the past, there were problems with workers operating the vehicle or each work device while in safety mode, which resulted in work being started without the work device being positioned at the appropriate height, or overlapping work being performed without being able to move from the travel start position.

In addition, the hydraulic system was subjected to excessive stress, which led to problems such as reduced durability and damage to hydraulic system components.

The above safety mode ends when the safety lamp 118 goes out, and since there is a possibility that the worker may overlook this, when the safety lamp 118 goes out, the buzzer 107b of the alarm device 107 is activated to notify the worker by voice, allowing the worker to move on to work quickly and reducing time waste.

Depending on whether the backup lamp 119 is lit or not, the operator can visually determine whether or not it is necessary to manually raise the working equipment attached to the rear of the traveling body 1 before performing a reverse operation, which prevents the operator from forgetting to switch to backup mode or forgetting that the conditions are such that backup mode cannot be used and reversing with the working equipment lowered.

This eliminates the need to redo work after disturbing the field where the implement has been used, and also prevents the implement from coming into contact with the crops being grown and damaging them.

In addition, the working device can be prevented from being pushed in the opposite direction to the working direction, preventing damage to the working device.

Although the conventional configuration also has a component equivalent to the backup lamp 119, it is located on the left and right sides of the pilot's seat, making it difficult to check while flying, and there was a problem of not realizing that the backup mode had been turned on.

There is a ride-on management machine that has a cabin 200 around the control section 5 and seat 8 of the traveling vehicle body 1 to protect the operator from wind, rain, sunlight, and the pesticide being sprayed. Rearview mirrors 201, 201 are attached to the upper part of the front side of the cabin 200, which show the area where the operator inside the cabin 200 can check the situation behind the machine and the storage status of the pest control boom 10.

The riding management machine equipped with the cabin 200 has pillars and other components that block visibility at the front, back, and all four corners, which maintain the strength of the cabin 200. In addition, glass is provided between the pillars, but this glass prevents the worker from leaning out without opening the entrance, making it difficult to check the turning angle of the front wheels 2, 2 while working.

In addition, because the pest control boom 10 during operation faces outward to the left and right of the machine, when workers visually check the end of the pest control boom 10, they tend to focus their gaze to the side, which causes them to neglect to check the front and rear of the machine, making it difficult to notice the occurrence of a problem.

To reduce blind spots during such work, as shown in Figures 28 and 29, front wheel mirrors 202, 202 that reflect the front wheels 2, 2 are installed below the left and right rearview mirrors 201, 201, with the angle adjustable via ball joints. The front wheel mirrors 202 are adjusted to a position that makes it easy for the worker to judge the turning angle of the front wheels 2, 2.

This allows the operator to visually check the turning angle of the front wheels 2, 2 while sitting in the seat 8 inside the cabin 200, and therefore allows the operator to quickly operate the steering wheel 6 to correct the course when the turning angle of the front wheels 2, 2 is such that the front wheels 2, 2 may come into contact with the crops, preventing damage to the crops and resulting in poor growth and reduced commercial value.

In addition, by providing a front wheel mirror 202 below the rearview mirror 201, the situation behind the aircraft and the turning angle of the front wheel 2 can be seen at the same time, preventing the driver from being distracted by one thing and overlooking a problem with the other.

In addition to the above configuration, the upper part of the pivoting hinge 11b that attaches the pest control boom 10 to the left and right ends of the front boom 11a is provided with a boom mirror 203 that can be adjusted in angle to reflect the pest control boom 10 that has been pivoted toward the outside of the machine body.

This allows the worker to view the end of the pest control boom 10 while facing forward during operation, and quickly check whether the pest control boom 10 is at an appropriate height for spraying the pesticide. This prevents the pesticide from being sprayed from a high place, which can lead to uneven distribution due to the effects of wind, and also prevents the pest control boom 10 from being positioned too low and damaging crops that come into contact with it.

In addition, because operators no longer need to concentrate their gaze on the sides of the aircraft, they can more easily notice any deviations in the aircraft's course or any problems that may arise, improving the accuracy of spraying pesticides and preventing damage to crops.

In addition, because the vertical height of the front boom 11a is changed using a parallel link, the angle of the boom mirror 203 mounted on the pivot hinge 11b is not related to changes in the vertical position, and there is no need to adjust the angle of the boom mirror 203 each time the height is adjusted.

However, even with this configuration, the rear of the aircraft is blocked by the chemical tank 9, etc., so the visible range is limited.

To make it easier to see behind the aircraft, a digital mirror 204 made of a liquid crystal panel or the like is installed inside the cabin 200 and on the upper front side of the aircraft, and capable of displaying images captured by a camera 205.

As shown in Figures 30 and 31(a), the camera 205 forms an installation space within the vertical width of the roof member provided on the top of the cabin 200, i.e., the visor 200a, and is provided within this installation space so that the shooting range can be moved up and down and left and right. In addition, a cable (not shown) that sends the video and image data captured by the camera 205 to the digital mirror 204 is also configured to pass through the inside of the visor 200a and be pulled into the cabin 200.

The chemical tank 9 has a width approximately equal to that of the cabin 200, so if the camera 205 has a wide-angle shooting range at least in the left-right direction and the digital mirror 204 has a long aspect ratio, it is easy to display the condition behind the aircraft on one screen.

As shown in FIG. 31(b), the digital mirror 204 can be turned off or switched to a state where it reflects an image similar to that of a mirror, so that it can be used as a rearview mirror. In this case, the digital mirror 204 should be installed at a height where the rear of the liquid tank 9 and the rear wheels 3, 3 can be reflected.

This allows the operator to view the area behind the traveling body 1 that is blocked by the chemical tank 9 while facing forward, making it possible to determine whether the spraying of chemicals is causing problems in the crops being grown and to appropriately adjust the turning angle of the rear wheels 3, 3.

In addition, since there is no need to look back, there is less risk of misalignment in the direction of travel or operational errors, improving workability.

When working in the fields, including spraying pesticides, workers often get soil or chemicals on their hands. When workers touch the digital mirror 204 to switch between the camera 205 image display and the rearview mirror display, dirt can reduce visibility of parts of the display surface.

To prevent this problem, as shown in Figures 30 and 31, a gesture sensor 206 is provided on the side or bottom of the digital mirror 204, which switches between a state showing the image captured by the camera 205 and a rear-view mirror state based on the direction in which the worker passes their hand or arm. This gesture sensor 206 is capable of determining the direction in which the worker's hand or arm moves, for example, from right to left or left to right, from the change in coordinates.

For example, when the digital mirror 204 is activated by turning the key on, it is set to a state in which it displays the image from the camera 205, and when the hand or arm is moved in one direction at a position away from the gesture sensor 206, downward or to the side, it switches to a rear-view mirror state. A control configuration can be considered in which, when the hand or arm is moved in the opposite direction while the digital mirror 204 is in the rear-view mirror state, it is set to a state in which it displays the image from the camera 205.

This allows the worker to switch the state without touching the digital mirror 204, preventing the display surface of the digital mirror 204 from becoming dirty and reducing visibility.

In addition, in case the gesture sensor 206 fails, the digital mirror 204 may be provided with a switch (not shown) for changing the display state.

When more operations are assigned, the action of switching the digital mirror 204 between a state in which it displays an image or video and a state in which it displays a rearview mirror may be performed by the operator moving his or her hand or arm from right to left, and repeated alternately.

Then, the movement from left to right may be such that the brightness of the digital mirror 204 is switched from light to dark and from dark to light according to the time of day and weather, for example, as shown in Fig. 32(a) and (b). This allows the brightness to be lowered during bright sunlight hours and raised when working on cloudy days or in the evening or early morning, making it possible to accurately distinguish what is reflected, improving work efficiency and quickly dealing with problems.

In addition, the front-to-back and back-to-front movements of the worker's arms can be assigned to control the up and down angles of the camera 205, making it possible to easily change the shooting range when the video or images captured become unsuitable for checking the rear due to the forward and backward tilt of the aircraft. Furthermore, the left and right movements of the hands or arms may also make it possible to change the shooting range of the camera 205 left and right.

As mentioned above, there is a risk that the spray pump 9a may be damaged if the amount of chemical in the chemical tank 9 runs low. However, this problem occurs during the chemical spraying process, and there is another problem that can occur when chemical spraying is not being performed.

The capacity of the chemical tank 9 is often several hundred liters, and as the chemical is used and the volume decreases, the fore-aft balance of the machine changes significantly. On flat ground, the weight of the front boom 11a at the front of the machine is unlikely to cause problems, but since the entrances and exits of farm fields are generally inclined, the fore-aft balance of the machine is significantly affected when passing through these.

For example, if the chemical tank 9 contains a large amount of chemical solution, the weight balance will be biased towards the rear of the machine, which may cause problems such as the front of the machine lifting up when moving uphill, i.e., when leaving the field, making it impossible to move.

Conversely, if there is almost no chemical solution in the chemical solution tank 9, the weight of the front boom 11a, etc. will cause the weight balance to be biased towards the front of the machine, which may cause problems such as the rear of the machine lifting up when moving downhill, i.e., when entering a farm field, making it impossible to travel.

It is not realistic to release several hundred liters of liquid medicine or to store several hundred liters of liquid medicine in the liquid medicine tank 9 or to provide a weight of the same weight as the liquid medicine in order to eliminate the weight imbalance, so when there is a lot of liquid medicine remaining, it is necessary to reverse to exit the field, and when there is only a small amount of liquid medicine remaining, it is necessary to reverse to enter the field.

The chemical tank 9 is mostly made of synthetic resin and is lightweight when no chemical is added.

To ensure that the operator drives appropriately as described above, as shown in Figures 16 and 33, a longitudinal tilt sensor 300 is provided on the vehicle body 1 to detect the longitudinal tilt angle of the vehicle body, and when the longitudinal tilt sensor 300 detects tilt, the control device 103, based on the remaining amount detected by the capacity sensor 301 provided in the chemical tank 9, displays on the steering unit 5 or information terminal that the vehicle should reverse to enter or exit the field if the conditions are met.

For example, when the longitudinal inclination sensor 300 detects the upward inclination angle of the front of the traveling body 1, it can be determined that the traveling body 1 is moving uphill, and therefore when the remaining amount of chemical solution detected by the capacitance sensor 301 is equal to or greater than a predetermined amount, a message is displayed on the control unit 5 or information terminal indicating that the vehicle should exit the field by moving in reverse. On the other hand, when the remaining amount of chemical solution is less than the predetermined amount, the weight balance between the front and rear is good, or the weight is biased toward the front of the vehicle, the above message is not displayed.

The above-mentioned capacitance sensor 301 must be capable of successively detecting the remaining amount of chemical solution using ultrasound, a laser, or the like, so it must either replace the above-mentioned chemical solution remaining sensor 111 or be provided separately. When the chemical solution stored in the chemical solution tank 9 is water or a non-flammable pesticide, there is no risk of fire, so the detection means may involve electricity or some heating, but when using a pesticide that contains flammable oily components, it is necessary to use a means that does not allow the temperature to reach the ignition point.

When displaying the message that reverse driving should be started, the buzzer 107b may be activated to ensure that the operator is aware of the message.

When the longitudinal inclination sensor 300 detects the downward forward inclination angle of the traveling body 1, it can be determined that the traveling body 1 is moving downhill, and therefore when the remaining amount of chemical solution detected by the capacitance sensor 301 is less than a predetermined amount, a message is displayed on the control unit 5 or information terminal indicating that the vehicle should enter the field in reverse. On the other hand, when the remaining amount of chemical solution is equal to or greater than the predetermined amount, the weight balance between the front and rear is good, or the weight is biased toward the rear of the vehicle, the above message is not displayed.

As a result of the above, it is possible to prevent the vehicle from traveling through the entrance and exit of a field without realizing that it may become unable to travel, so there is no need to move the traveling vehicle body 1 in and out of the field using a separate working machine, such as a tractor, etc., and this prevents the time, labor, and costs required for unnecessary work from being incurred.

The present invention allows the operator to grasp the conditions of the underside, sides and rear of the vehicle while facing the direction of travel of the vehicle, making it ideal for work vehicles equipped with pesticide spraying devices.

Reference Signs List 1 Traveling vehicle body 2 Front wheel 3 Rear wheel 9 Chemical liquid tank 9a Spray pump 10 Pest control boom (spraying device)
103 Control device 107 Notification device 111 Chemical solution remaining amount sensor (remaining amount detection member)
200 Cabin (boarding area)
201 Rearview mirror (rear display member)
202 Front wheel mirror (front wheel display member)
203 Boom mirror (dispersion device display member)
204 Digital mirror (rear display member)
205 Camera (photography device)
206 Gesture sensor (motion detection member)
300 Front/rear tilt sensor (tilt detection member)

Claims (4)

A work vehicle having front wheels (2) and rear wheels (3) that can rotate left and right on a traveling body (1), a spraying device (10) for spraying a chemical agent that can rotate about an axis in the vertical direction, the spraying device (10) being configured to rotate to a chemical agent spraying position in the left and right direction and a stored position along the vehicle body, a boarding section (200) for a worker to board, and a rear display member (201) for visually confirming the rear of the traveling body (1),
A front wheel display member (202) on which the front wheel (2) is displayed on a display surface is provided below the rear display member (201);
A work vehicle characterized in that a spraying device display member (203) is provided in front of the rear display member (201) and near the rotation fulcrum of the spraying device (10), on whose display surface the spraying device (10) rotated toward the outside of the vehicle body is displayed. A liquid medicine tank (9) for storing the liquid medicine to be sprayed by the spraying device (10) is provided at the rear of the riding section (200), and a photographing device (205) for photographing the area behind the liquid medicine tank (9) is provided;
2. The work vehicle according to claim 1, wherein the riding section (200) is provided with a rear display member (204) for displaying the video and images captured by the image capturing device (205). The work vehicle according to claim 2, characterized in that the rear display member (204) is configured to be switchable to a mirror state that displays a reflected image. A motion detection member (206) is provided on the rear display member (204) to detect the motion of the operator,
The work vehicle according to claim 3, further comprising a control device (103) for switching the video or image display state and the mirror surface state of the rear display member (204) in accordance with the motion detected by the motion detection member (206).