How to fold a tri-fold boom sprayer and its boom.

Abstract

This invention provides a three-fold boom sprayer and a folding method for a three-fold boom that can be easily, reliably, and safely folded into three sections using the same folding operation as a two-fold side boom, while suppressing increases in manufacturing costs. [Solution] The system includes a deployment path 44 for the second hydraulic cylinder, a storage path 45 for the second hydraulic cylinder, a deployment path 46 for the third hydraulic cylinder, a storage path 47 for the third hydraulic cylinder, a first interlock valve 48 that opens the deployment path 46 for the third hydraulic cylinder only when the second boom 32 is fully deployed and closes it otherwise, and a second interlock valve 49 that opens the storage path 45 for the second hydraulic cylinder only when the third boom 33 is fully stored and closes it otherwise.

Description

Technical Field

[0001] The present invention relates to a boom sprayer used for spraying chemical liquids and the like, and more particularly to a three - fold boom sprayer capable of folding three side booms extending left and right, and a method for folding the three - fold boom.

Background Art

[0002] A boom sprayer is mounted on a traveling vehicle such as a tractor or a towing vehicle to spray chemical liquids or the like in a field. The boom sprayer is composed of a center boom and side booms extending left and right from the center boom.

[0003] The longer the side boom is, the more advantages there are in spraying chemical liquids over a wide area. On the other hand, if the side boom is made longer, there are disadvantages such as a decrease in maneuverability during movement without chemical liquid spraying or the need for a large storage space.

[0004] In response to such disadvantages, boom sprayers that can fold the side booms during movement or storage have been proposed. For example, Japanese Patent Application Laid - Open No. 2021 - 69303 proposes a boom sprayer that can fold the left and right side booms backward with respect to a center boom fixed in front of a traveling vehicle (Patent Document 1). Also, the applicant of the present application has developed and disclosed an invention related to a boom sprayer that can fold the left and right side booms in a two - fold manner and further fold the side booms with respect to the center boom in Japanese Patent Application Laid - Open No. 2013 - 116078 (Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] By the way, based on the advantages of the length mentioned above, there is a need to further shorten the folded length without shortening the side boom, in order to improve maneuverability during transport and flexibility in storage location.

[0007] Therefore, the applicant is developing a technology to fold the side boom into three sections. In the development process, they discovered that adopting a three-fold boom increases the number of steps required for folding, which can lead to operator errors. If the folding procedure is performed incorrectly, there is a risk that the boom may come into contact with or be damaged by surrounding objects or people.

[0008] Furthermore, conventionally, multiple hydraulic cylinders are used to control the folding of the side boom, and each hydraulic cylinder is controlled by a solenoid valve. However, folding it into three sections increases the number of hydraulic cylinders, and requires expensive solenoid valves with a large number of control valves, which leads to a significant increase in manufacturing costs.

[0009] The present invention was made to solve the above-mentioned problems and challenges, and aims to provide a three-fold boom sprayer and a method for folding a three-fold boom that can be easily, reliably, and safely folded into three sections using the same folding operation as a two-fold side boom, while suppressing an increase in manufacturing costs. [Means for solving the problem]

[0010] The present invention provides a three-fold boom sprayer that can be folded using the same operating method and procedure as a two-fold boom sprayer, and that can fold the side booms into three sections using a solenoid valve having the same number of control valves as a two-fold boom sprayer, comprising a center boom, a first boom foldably connected to the center boom, a second boom foldably connected to the tip of the first boom, and a third boom foldably connected to the tip of the second boom, wherein a second hydraulic cylinder is positioned at the connection point between the first boom and the second boom and extends and retracts to deploy and retract the second boom, a third hydraulic cylinder is positioned at the connection point between the second boom and the third boom and extends and retracts to deploy and retract the third boom, a solenoid valve is connected to a hydraulic pump and an oil tank for oil recovery and controls the supply of oil to the second and third hydraulic cylinders and controls oil recovery, and a solenoid valve is connected to the solenoid valve and the second hydraulic cylinder and when the second boom is deployed, the second The system includes: a deployment path for a second hydraulic cylinder which serves as a route for supplying oil to the hydraulic cylinder; a storage path for a second hydraulic cylinder which is connected to the solenoid valve and the second hydraulic cylinder and serves as a route for supplying oil to the second hydraulic cylinder when the second boom is retracted; a deployment path for a third hydraulic cylinder which branches off from the deployment path for a second hydraulic cylinder and is connected to the third hydraulic cylinder and serves as a route for supplying oil to the third hydraulic cylinder when the third boom is deployed; a storage path for a third hydraulic cylinder which branches off from the storage path for a second hydraulic cylinder and is connected to the third hydraulic cylinder and serves as a route for supplying oil to the third hydraulic cylinder when the third boom is retracted; a first interlock valve installed in the deployment path for a third hydraulic cylinder which opens the deployment path for a third hydraulic cylinder only when the second boom is fully deployed and closes otherwise; and a second interlock valve installed between the branch in the storage path for a second hydraulic cylinder and the second hydraulic cylinder which opens the storage path for a second hydraulic cylinder only when the third boom is fully retracted and closes otherwise.

[0011] Furthermore, in one aspect of the present invention, in order to solve the problem of preventing the deployed third boom from unintentionally folding due to inertial force when the vehicle stops due to braking or vibrations during travel, pilot check valves may be provided in the path between the first interlock valve and the third hydraulic cylinder in the deployment path for the third hydraulic cylinder and in the storage path for the third hydraulic cylinder, and the pilot check valves may be configured to open both paths when hydraulic pressure is received in the direction of the third hydraulic cylinder in either path, and to close both paths when no hydraulic pressure is received in the direction of the third hydraulic cylinder in either path.

[0012] Furthermore, in one aspect of the present invention, in order to solve the problem of preventing the third boom, which is folded earlier, from unintentionally deploying due to its own weight when the second boom is folded, the third boom is pivotally supported by a vertical axis at the tip of the second boom and configured to be rotatable in a substantially horizontal direction, and the second boom is pivotally supported by a horizontal axis perpendicular to the longitudinal direction of the boom at the tip of the first boom and configured to be rotatable in a substantially vertical direction, and a third boom deployment prevention mechanism is provided to prevent the third boom from deploying when the tip of the second boom is tilted toward the first boom side beyond the uppermost part of the rotation trajectory.

[0013] Furthermore, in one aspect of the present invention, in order to solve the problem of automatically preventing the deployment of the third boom when the tip of the second boom tilts toward the first boom side beyond the uppermost part of the rotational trajectory, the third boom deployment prevention mechanism is a mechanism that connects the third boom and the second boom, and comprises a connecting projection that is positioned to protrude toward the other boom side on either boom, and a projection holding means that holds the connecting projection when the third boom is folded on the other boom, and the projection holding means guides the connecting projection during the storage operation of the third boom. The device may also include a projection guide groove, a projection holding member having a substantially U-shaped opening into which the connecting projection can be fitted, a projection holding member pivotally supported in a position into which the connecting projection guided by the projection guide groove can be fitted, and which rotates on its axis while changing the angle of the opening when pushed by the fitted connecting projection to hold the connecting projection in the opening, and a holding locking member configured to move up and down, which descends by its own weight when the tip of the second boom is tilted toward the first boom side beyond the uppermost part of the rotation trajectory and locks the projection holding member in a non-rotatable state.

[0014] The folding method for a three-fold boom according to the present invention solves the problem of enabling the safe folding of a three-fold boom, and comprises a center boom, a first boom foldably connected to the center boom, a second boom foldably connected to the tip of the first boom, and a third boom foldably connected to the tip of the second boom, comprising: a third boom folding step of rotating the third boom in a substantially horizontal direction and folding it to a position where it is substantially parallel to the second boom; a second boom folding step of rotating the second boom in a substantially vertical direction and folding it to a position where the tip of the second boom is tilted toward the first boom beyond the uppermost part of the rotation trajectory; and a first boom folding step of rotating the first boom in a substantially horizontal direction or diagonally upward from the horizontal and folding it to a position where the tip faces forward.

[0015] Furthermore, in one aspect of the present invention, in order to solve the problem of preventing the folded third boom from unintentionally unfolding due to its own weight during storage, the invention may include a third boom connecting step that connects the third boom to the second boom so that the third boom does not unfold due to its own weight when the tip of the second boom tilts toward the first boom side beyond the uppermost part of the rotation trajectory during the second boom folding step. [Effects of the Invention]

[0016] According to the present invention, the side boom can be folded into three sections easily, reliably, and safely using the same folding operation as a two-fold side boom, while suppressing an increase in manufacturing costs. [Brief explanation of the drawing]

[0017] [Figure 1] This is a rear perspective view showing one embodiment of the three-fold boom sprayer according to the present invention. [Figure 2] This is a front view showing the connection between the first boom and the second boom in this embodiment, with the second boom extended. [Figure 3] This is a front view showing the connection between the first boom and the second boom in this embodiment, with the second boom folded. [Figure 4] This is a plan view showing the connection between the second boom and the third boom in this embodiment, with the third boom extended. [Figure 5] This is a plan view showing the connection between the second boom and the third boom in this embodiment, with the third boom folded. [Figure 6] This is a schematic diagram showing the boom folding control mechanism in this embodiment. [Figure 7] This is a rear perspective view showing the third boom deployment prevention mechanism in this embodiment. [Figure 8]In the third boom folding step of the folding method of the three-fold boom according to the present invention, it is a schematic diagram showing the boom folding control mechanism when the third boom is being folded. [Figure 9] In the present embodiment, it is a longitudinal sectional view showing the states of the second boom, the third boom, and the third boom deployment prevention mechanism immediately before the third boom reaches the fully retracted state. [Figure 10] In the present embodiment, it is a longitudinal sectional view showing the states of the second boom, the third boom, and the third boom deployment prevention mechanism when the third boom reaches the fully retracted state. [Figure 11] In the second boom folding step of the present embodiment, it is a schematic diagram showing the boom folding control mechanism when the second boom is being folded. [Figure 12] In the present embodiment, it is a longitudinal sectional view showing the state of the third boom deployment prevention mechanism when the second boom and the third boom are inverted up and down. [Figure 13] In the second boom deployment step of the present embodiment, it is a schematic diagram showing the boom folding control mechanism when the second boom is being deployed. [[ID=十七]] [Figure 14] In the third boom deployment step of the present embodiment, it is a schematic diagram showing the boom folding control mechanism when the third boom is being deployed.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, an embodiment of a three-fold boom sprayer according to the present invention will be described with reference to the drawings.

[0019] The three-fold boom sprayer 1 of this embodiment is a boom sprayer equipped with a mechanism for spraying chemicals and the like, and as shown in Figure 1, it has a center boom 2, side booms 3 provided at both the left and right ends of the center boom 2, a boom folding control mechanism 4 for folding the side booms 3 as shown in Figure 6, and a third boom deployment prevention mechanism 5 for preventing the third boom 33 from unintentionally deploying when the second boom 32 is folded as shown in Figure 7. Each of these components will be described in detail below.

[0020] As shown in Figure 1, the center boom 2 has side booms 3 connected to both its left and right ends, and in this embodiment, it is installed at the rear of the towing vehicle T.

[0021] Furthermore, the installation of the center boom 2 is not limited to the towing vehicle T, but may also be installed on vehicles that are primarily capable of traveling in fields, such as tractors.

[0022] The side booms 3 are connected to both the left and right ends of the center boom 2 and are booms that can be deployed when spraying chemicals and folded when moving or storing without spraying chemicals. In this embodiment, the side booms 3 are configured to be foldable into three sections and, as shown in Figure 1, consist of a first boom 31 connected to the center boom 2, a second boom 32 connected to the tip of the first boom 31, and a third boom 33 connected to the tip of the second boom 32.

[0023] The first boom 31 is foldably connected to the left and right ends of the center boom 2, and in this embodiment, it is rotatably connected to the center boom 2 in a substantially horizontal direction or diagonally upward from the horizontal. The upper part of the first boom 31 is provided with second and third boom support members 311 that support the foldable second and third booms.

[0024] In this embodiment, the second and third boom support members 311 have their upper ends formed in a substantially Y shape, and the folded second and third booms are supported by resting them on the substantially Y-shaped portion.

[0025] The second boom 32 is foldably connected to the tip of the first boom 31, and in this embodiment, as shown in Figures 2 and 3, it is pivotally supported at the tip of the first boom 31 by a horizontal axis 321 perpendicular to the longitudinal direction of the boom. Therefore, the second boom 32 is rotatable in a substantially vertical direction, and in this embodiment, it is configured to be foldable to a position where its tip tilts toward the first boom 31 side beyond the uppermost part of the rotation trajectory and is supported by the second and third boom support members 311 on the upper part of the first boom 31.

[0026] The third boom 33 is foldably connected to the tip of the second boom 32. In this embodiment, as shown in Figures 4 and 5, it is pivotally supported by a vertical axis 331 at the tip of the second boom 32, and is configured to rotate substantially horizontally and fold to a position substantially parallel to the second boom 32.

[0027] Next, the boom folding control mechanism 4 in this embodiment will be described. The boom folding control mechanism 4 in this embodiment is mainly a mechanism for folding the side boom 3, and as shown in Figure 6, it includes a second hydraulic cylinder 41, a third hydraulic cylinder 42, a solenoid valve 43, an deployment path 44 for the second hydraulic cylinder, a storage path 45 for the second hydraulic cylinder, an deployment path 46 for the third hydraulic cylinder, a storage path 47 for the third hydraulic cylinder, a first interlock valve 48, a second interlock valve 49, and a pilot check valve 50.

[0028] The second hydraulic cylinder 41 is a drive device that extends and retracts the second boom by hydraulic pressure, and in this embodiment, it is equipped with an extension port 411 and a retraction port 412.

[0029] The extension port 411 is a port for circulating oil inside and outside the cylinder, and when oil is supplied into the cylinder through this port, the second hydraulic cylinder 41 extends.

[0030] The contraction port 412, like the extension port 411, is a port for circulating oil inside and outside the cylinder, and when oil is supplied into the cylinder through this port, the second hydraulic cylinder 41 contracts.

[0031] As shown in Figures 2 and 3, the second hydraulic cylinder 41 is connected to a link mechanism 413 provided between the first boom 31 and the second boom 32. By retracting, it can fold the second boom 32 from the deployed state to the stored state, and by extending, it can deploy the second boom 32 from the stored state to the deployed state.

[0032] The third hydraulic cylinder 42 is a drive device that extends and retracts the third boom 33 by hydraulic pressure, and, like the second hydraulic cylinder 41, has an extension port 421 into which oil flows when it extends and a retraction port 422 into which oil flows when it retracts.

[0033] As shown in Figures 4 and 5, the third hydraulic cylinder 42 is connected to a link mechanism 423 located between the second boom 32 and the third boom 33. Unlike the second hydraulic cylinder 41, it is configured to extend to fold the third boom 33 from the deployed state to the retracted state, and to retract to deploy the third boom 33 from the retracted state to the deployed state.

[0034] Furthermore, in the case of the second hydraulic cylinder 41 and the third hydraulic cylinder 42, the direction in which they extend or contract when folding from the deployed state to the stored state and when deploying from the stored state to the deployed state is not limited to the direction in this embodiment, but can be selected as appropriate.

[0035] The solenoid valve 43 is a control valve that controls the opening and closing of the oil supply and oil recovery paths. As shown in Figure 6, it is connected to a hydraulic pump 431 for supplying oil, an oil tank 432 for recovering oil, and a solenoid valve control device 433 that controls the opening and closing of the valve by operator operation. In this embodiment, the solenoid valve 43 also has an deployment port 434 and a retraction port 435.

[0036] The deployment port 434 is connected to the hydraulic pump 431 to supply oil to the second hydraulic cylinder 41 and the third hydraulic cylinder 42 when the second boom 32 and the third boom 33 are deployed. When the second boom 32 and the third boom 33 are retracted, the deployment port 434 is also used as a port to recover oil by connecting to the oil tank 432.

[0037] The storage port 435 is connected to the hydraulic pump 431 to supply oil to the second hydraulic cylinder 41 and the third hydraulic cylinder 42 when the second boom 32 and the third boom 33 are stored, and is also used as a port to recover oil when the second boom 32 and the third boom 33 are deployed, by connecting to the oil tank 432.

[0038] In this embodiment, the solenoid valve 43 is mainly described as being used to control the extension and retraction of the second hydraulic cylinder 41 and the third hydraulic cylinder 42. However, it is not limited to controlling these cylinders, and as shown in Figure 1, it can also be used to control the first hydraulic cylinder 312 used to move the first boom 31 up and down, the first opening / closing hydraulic cylinder 313 that opens and closes the first boom 31, and various hydraulic cylinders 21 that adjust the left and right tilt and height of the center boom 2.

[0039] The deployment path 44 for the second hydraulic cylinder is mainly used to supply oil to the second hydraulic cylinder 41 when deploying the second boom 32. In this embodiment, as shown in Figure 6, it is connected so that oil can flow between the deployment port 434 of the solenoid valve 43 and the extension port 411 of the second hydraulic cylinder 41.

[0040] The storage path 45 for the second hydraulic cylinder is mainly used to supply oil to the second hydraulic cylinder 41 when the second boom 32 is stored (folded), and in this embodiment, it is connected so that oil can flow between the storage port 435 of the solenoid valve 43 and the retraction port 412 of the second hydraulic cylinder 41.

[0041] The deployment path 46 for the third hydraulic cylinder is mainly used to supply oil to the third hydraulic cylinder 42 when deploying the third boom 33. In this embodiment, it branches off from the deployment path 44 for the second hydraulic cylinder and is connected to allow oil to flow between the branching point 441 and the retraction port 422 of the third hydraulic cylinder 42.

[0042] The storage path 47 for the third hydraulic cylinder is mainly used to supply oil to the third hydraulic cylinder 42 when the third boom 33 is retracted. In this embodiment, it branches off from the storage path 45 for the second hydraulic cylinder and is connected to allow oil to flow between the branching point 451 of the storage path and the extension port 421 of the third hydraulic cylinder 42.

[0043] The first interlock valve 48 is a valve that functions to open the installed path when its switch 481 is pressed and to close the path when the switch 481 is not pressed, and in this embodiment it is installed in the deployment path 46 for the third hydraulic cylinder.

[0044] Furthermore, as shown in Figures 2 and 3, the switch 481 of the first interlock valve 48 is located at the tip of the first boom 31. When the second boom 32 is fully deployed, the switch 481 is pushed by the second boom 32 to open the deployment path 46 for the third hydraulic cylinder, and when the second boom 32 is not fully deployed, the switch 481 closes the deployment path 46 for the third hydraulic cylinder.

[0045] The second interlock valve 49, like the first interlock valve 48, is a valve that opens the installed path when the switch 491 is pressed and closes the path when the switch 491 is not pressed. In this embodiment, as shown in Figure 6, it is installed in the storage path 45 for the second hydraulic cylinder between the storage path branch 451 and the contraction port 412 of the second hydraulic cylinder 41.

[0046] Furthermore, as shown in Figures 4 and 5, the switch 491 of the second interlock valve 49 is located on the side of the tip of the second boom 32, on the side where the third boom 33 is folded. When the third boom 33 is fully retracted, the switch 491 is pushed by the third boom 33 to open the deployment path 45 for the second hydraulic cylinder, and when the third boom 33 is not fully deployed, the switch 491 closes the deployment path 45 for the second hydraulic cylinder.

[0047] The pilot check valve 50 is a check valve provided to prevent the third boom 33 from unintentionally opening or closing due to oil leakage from the third hydraulic cylinder 42 when oil is not supplied from the solenoid valve 43 to the third hydraulic cylinder 42. In this embodiment, it has two pathways, and is configured to open both pathways when hydraulic pressure is received in one direction in either pathway, and to close both pathways when no hydraulic pressure is received in either pathway.

[0048] In this embodiment, the pilot check valve 50 is configured such that one system is provided in the path between the first interlock valve 48 and the third hydraulic cylinder 42 in the deployment path 46 for the third hydraulic cylinder, and the other system is provided in the storage path 47 for the third hydraulic cylinder. Both paths are opened when hydraulic pressure is received in the direction of the third hydraulic cylinder 42 in either path, and both paths are closed when no hydraulic pressure is received in the direction of the third hydraulic cylinder 42 in either path.

[0049] Next, the third boom deployment prevention mechanism 5 will be described with reference to Figures 7, 9, 10, and 12. The third boom deployment prevention mechanism 5 is a mechanism for connecting the third boom 33 and the second boom 32 in order to prevent the third boom 33 from unintentionally deploying when the second boom 32 is folded. In this embodiment, as shown in Figure 7, it is composed of a connecting projection 51 on one of the booms and a projection holding means 52 on the other boom.

[0050] The connecting projection 51 is positioned to protrude from one boom towards the other boom and is held by the projection holding means 52. In this embodiment, it consists of a rod-shaped member provided on the tip side of the third boom 33. Specifically, as shown in Figures 7 and 9, the connecting projection 51 is positioned on the surface facing the second boom 32 when the third boom 33 is folded, and is installed substantially parallel to the third boom 33 with a gap between it and the third boom 33.

[0051] The connecting projection 51 is not limited to a rod-shaped member, but can be any shape that can be held by the projection holding means 52, and may be appropriately selected from, for example, a ring-shaped member.

[0052] The projection holding means 52 is a means for holding the connecting projection 51 when the third boom 33 and the second boom 32 are folded, and in this embodiment it mainly comprises a projection guide groove 521, a projection holding member 522, and a holding part locking member 523.

[0053] As shown in Figures 7 and 9, the projection guide groove 521 is a groove that guides the connecting projection 51 when the third boom 33 is being retracted, and is a groove formed in a concave shape at a position facing the connecting projection 51 when the third boom 33 is folded. In this embodiment, inclined guide pieces 524 are provided at the upper and lower parts of the entrance to the projection guide groove 521 to guide the connecting projection 51 to the projection guide groove 521. The upper and lower inclined guide pieces 524 are inclined to expand outward, so that even if the position of the connecting projection 51 shifts vertically due to vibration or the like, the connecting projection 51 is guided to the projection guide groove 521 along the inclined guide pieces 524.

[0054] The projection holding member 522 is a member for holding the connecting projection 51. In this embodiment, as shown in Figures 9 and 10, it is formed in a shape having a substantially U-shaped opening 525 into which the connecting projection 51 can be fitted, and is pivotally supported in a position into which the connecting projection 51, guided by the projection guide groove 521, can be fitted.

[0055] The projection-holding member 522 is pushed by the connecting projection 51 that fits into the projection guide groove 521, causing it to rotate on its axis while changing the angle of the opening 525. In this way, the projection-holding member 522 is configured to hold the connecting projection 51 in the opening 525.

[0056] The retaining lock member 523 is a member for locking the projection retaining member 522, which holds the connecting projection 51 when the second boom 32 is folded, into a non-rotatable state. As shown in Figures 9, 10, and 12, this retaining lock member 523 is configured to move up and down, and when the tip of the second boom 32 tilts toward the first boom 31 side beyond the uppermost part of the rotation trajectory, it descends by its own weight and locks into the projection retaining member 522. In this embodiment, it is pivotally supported so as to be able to swing up and down, and is configured to swing downward by its own weight when it is in an upside-down state.

[0057] Furthermore, the retaining locking member 523 is not limited to a configuration that is pivotally supported, but may be appropriately selected from other members such as one that is vertically slidable and descends by its own weight when upside down.

[0058] Next, the operation of each component in the three-fold boom sprayer 1 of this embodiment will be explained along with the folding method of the three-fold boom according to the present invention.

[0059] The folding method for the three-fold boom of this embodiment is a method for folding the side boom 3 in the deployed state, and mainly comprises a third boom folding step of folding the third boom 33, a second boom folding step of folding the second boom 32, a third boom connecting step of connecting the third boom 33 to the second boom 32, and a first boom folding step of folding the first boom 31.

[0060] In this embodiment, the third boom folding step is to rotate the third boom 33 in a substantially horizontal direction and fold it to a position where it is substantially parallel to the second boom 32, as shown in Figures 4 and 5. In this embodiment, this is performed by supplying oil to the storage path 45 for the second hydraulic cylinder using the solenoid valve 43.

[0061] As shown in Figure 2, the switch 481 of the first interlock valve 48 is pressed due to the deployment of the second boom 32, opening the deployment path 46 for the third hydraulic cylinder. On the other hand, as shown in Figure 4, the switch 491 of the second interlock valve 49 is not pressed due to the deployment of the third boom 33, and the path between the storage path branch 451 in the storage path 45 for the second hydraulic cylinder and the second hydraulic cylinder 41 remains closed.

[0062] When oil is supplied to the storage path 45 for the second hydraulic cylinder in this state, as shown in Figure 8, the oil is supplied from the storage path branch 451 of the storage path 45 for the second hydraulic cylinder to the storage path 47 for the third hydraulic cylinder.

[0063] The pilot check valve 50, located in the storage path 47 for the third hydraulic cylinder, receives hydraulic pressure toward the third hydraulic cylinder 42 from the supplied oil. Therefore, the pilot check valve 50 opens both paths and opens the deployment path 46 for the third hydraulic cylinder along with the storage path 47 for the third hydraulic cylinder.

[0064] As a result, oil is supplied into the third hydraulic cylinder 42 from the extension port 421 of the third hydraulic cylinder 42.

[0065] The third hydraulic cylinder 42 extends when oil is supplied to the extension port 421. As shown in Figures 4 and 5, the third hydraulic cylinder 42 pushes the link mechanism 423, which causes the third boom 33 to rotate around the vertical axis 331 and fold to a position approximately parallel to the second boom 32. The folded third boom 33 pushes the switch 491 of the second interlock valve 49, opening the storage path 45 for the second hydraulic cylinder.

[0066] Meanwhile, oil flows out of the contraction port 422 of the third hydraulic cylinder 42. At this time, the pilot check valve 50 and the first interlock valve 48 open the deployment path 46 for the third hydraulic cylinder. Also, since the second hydraulic cylinder is fully extended, it cannot be extended any further. Therefore, the oil that flows out of the contraction port 422 flows through the deployment path 46 for the third hydraulic cylinder and flows from the deployment path branch 441 towards the solenoid valve 43.

[0067] In the solenoid valve 43, the deployment port 434 is connected to the oil tank 432, so the oil that flows in from the deployment port 434 is recovered into the oil tank 432.

[0068] Furthermore, when the third boom 33 is folded and stored, the connecting projection 51 provided at the tip of the third boom 33 is held in place by the projection holding member 522 of the projection holding means 52 of the second boom 32.

[0069] Specifically, as shown in Figure 9, the connecting projection 51 is guided into the projection guide groove 521 as the third boom 33 is folded. Even if the position of the connecting projection 51 is shifted vertically due to vibration or boom deflection, the connecting projection 51 is guided into the projection guide groove 521 along the inclined guide piece 524, so it can be reliably fitted into the projection guide groove 521.

[0070] The projection holding member 522 fits the connecting projection 51, guided by the projection guide groove 521, into the roughly U-shaped opening 525. Furthermore, as the projection holding member 522 is pushed toward the back of the projection guide groove 521 by the connecting projection 51, it rotates on its axis, changing the angle of the opening 525, as shown in Figure 10. When the third boom 33 is folded to the fully stored state, the connecting projection 51 is surrounded and held by the opening 525 and projection guide groove 521 of the projection holding member 522. However, at this point, the projection holding member 522 is not fixed by the holding part locking member 523, so the third boom 33 is in a deployable state.

[0071] As a result, the third boom 33 is fully retracted, the third boom folding step is completed, and the process moves on to the second boom folding step.

[0072] In this embodiment, the second boom folding step is automatically started after the completion of the third boom folding step by continuing to supply oil from the solenoid valve 43 to the storage path 45 for the second hydraulic cylinder. Therefore, the operator can perform the folding operation without being aware of the order in which to fold the second boom 32 and the third boom 33.

[0073] Specifically, as shown in Figure 11, the oil supplied from the solenoid valve 43 to the storage path 45 for the second hydraulic cylinder flows to the storage path branch 451. Since the third boom 33 is in the fully retracted state and the third hydraulic cylinder 42 cannot extend any further, the oil does not flow in the direction of the third hydraulic cylinder 42.

[0074] Meanwhile, the switch 491 of the second interlock valve 49 is pressed by the third boom 33, opening the storage path for the second hydraulic cylinder between the storage path branch 451 and the second hydraulic cylinder 41. As a result, the oil supplied to the storage path branch 451 flows toward the second hydraulic cylinder 41 and is supplied into the second hydraulic cylinder 41 from the retraction port 412.

[0075] The second hydraulic cylinder 41 begins to retract when oil is supplied to the retraction port 412. By retracting, the second hydraulic cylinder 41 pulls the connection point with the link mechanism 413 towards the first boom 31.

[0076] The second boom 32 is lifted by the movement of the link mechanism 413 being pulled towards the first boom, and rotates vertically around the horizontal axis 321.

[0077] When the second boom 32 begins to rotate, the switch 481 of the first interlock valve 48, which was being pressed by the second boom 32, becomes unpressed. As a result, the first interlock valve 48 closes the deployment path 46 for the third hydraulic cylinder.

[0078] Furthermore, as the second hydraulic cylinder 41 contracts, the oil discharged from the extension port 411 of the second hydraulic cylinder 41 flows to the deployment path branch 441 of the deployment path 44 for the second hydraulic cylinder. As described above, since the deployment path 46 for the third hydraulic cylinder is closed by the first interlock valve 48, the oil that has flowed to the deployment path branch 441 flows towards the solenoid valve 43. The oil that flows in from the deployment port 434 of the solenoid valve 43 is then collected in the oil tank 432.

[0079] The third boom connection step is performed during the folding of the second boom 32 by the second boom folding step. In this embodiment, the third boom connection step automatically connects the third boom 33 and the second boom 32 when the tip of the second boom 32 tilts toward the first boom 31 side beyond the uppermost part of the rotation trajectory by the third boom deployment prevention mechanism 5.

[0080] Specifically, as shown in Figure 12, when the tip of the second boom 32 tilts toward the first boom 31 side beyond the top of the rotation trajectory, the third boom deployment prevention mechanism 5 reverses its vertical position. As a result, the holding lock member 523 descends due to its own weight and locks into the projection holding member 522.

[0081] The projection holding member 522 is locked to the holding part locking member 523, preventing it from rotating. As a result, the connecting projection 51 is held by the projection assisting means 52, the third boom 33 is connected to the second boom 32, and the third boom 33 is prevented from unintentionally deploying.

[0082] As described above, the second boom 32, together with the folded third boom 33, is safely folded until it is supported by the second and third boom support members 311. This completes the second boom folding step, and the side boom 3 is folded into a three-fold state.

[0083] The first boom folding step involves rotating the first boom 31 in a nearly horizontal direction or diagonally upward from the horizontal, causing its tip to lift upward. Additionally, oil is supplied to the first opening / closing hydraulic cylinder 313 by the solenoid valve 43, causing the first boom 31 to fold to a position where its tip faces forward. Specifically, the solenoid valve 43 supplies oil to a path connected to the first hydraulic cylinder 312. With the supply of oil, the first hydraulic cylinder 312 folds the first boom 31 to a position where its tip faces forward. This completes the first boom folding step.

[0084] Next, a method for deploying the folded side boom 3 will be described. The procedure for deploying the side boom 3 is the reverse of the procedure for storing it, and in this embodiment, it includes a first boom deployment step, a second boom deployment step, a third boom uncoupling step, and a third boom deployment step.

[0085] In the first boom deployment step, the solenoid valve 43 supplies oil to the first hydraulic cylinder 312 and the first opening / closing hydraulic cylinder 313, and the side booms 3, which are folded into three sections, are deployed to the left and right to a position approximately 180° relative to the center boom 2.

[0086] Next, in the second boom deployment step, as shown in Figure 13, oil is supplied from the deployment port 434 of the solenoid valve 43 to the deployment path 44 for the second hydraulic cylinder. Since the second boom 32 is in the retracted state, as shown in Figure 3, the switch 481 of the first interlock valve 48 is not pressed, and the first interlock valve 48 closes the deployment path 46 for the third hydraulic cylinder. On the other hand, since the third boom 33 is in the retracted state, as shown in Figure 5, the switch 491 of the second interlock valve 49 is pressed, and the second interlock valve 49 opens the storage path 45 for the second hydraulic cylinder.

[0087] Therefore, the oil supplied from the deployment port 434 is supplied to the deployment port 411 of the second hydraulic cylinder 41, and the second hydraulic cylinder 41 extends. By extending, the second hydraulic cylinder 41 moves the connection point with the link mechanism 413 toward the tip.

[0088] As a result, the second boom 32 rotates around the horizontal axis 321 and rotates to the fully deployed state as shown in Figure 2. At this time, the switch 481 of the first interlock valve 48 is pressed by the base end of the second boom 32, and the first interlock valve 48 opens the deployment path 46 for the third hydraulic cylinder.

[0089] Furthermore, in the third boom release step, the connection between the second boom 32 and the third boom 33 is released while the second boom 32 is still being deployed. Specifically, when the tip of the second boom 32 goes beyond the top of the rotation trajectory and tilts toward the tip side (opposite side from the first boom 31), the third boom deployment prevention mechanism 5 reverses its vertical position.

[0090] When the mechanism is reversed, the retaining lock member 523, which was locked to the projection retaining member 522, descends due to its own weight, releasing the lock on the projection retaining member 522. This allows the projection retaining member 522 to rotate on its axis, enabling the deployment of the third boom 33.

[0091] This completes the second boom deployment step and the third boom uncoupling step, and we proceed to the third boom deployment step.

[0092] In this embodiment, the third boom deployment step is automatically started after the completion of the second boom deployment step by continuing to supply oil from the solenoid valve 43 to the deployment path 44 for the second hydraulic cylinder. Therefore, even during deployment, the operator can perform the deployment operation without being aware of the order in which the second boom 32 and the third boom 33 are deployed, and the second boom 32 and the third boom 33 can be deployed safely.

[0093] As shown in Figure 14, if oil is continuously supplied to the deployment path 44 for the second hydraulic cylinder, the oil will flow to the deployment path branch 441. The second boom 32 is fully deployed and the second hydraulic cylinder 41 cannot extend any further, so no oil flows from the deployment path branch 441 towards the second hydraulic cylinder 41. On the other hand, the deployment path 46 for the third hydraulic cylinder is open because the switch 481 of the first interlock valve 48 is pressed. Therefore, oil flows from the deployment path branch 441 towards the third hydraulic cylinder 42.

[0094] The pilot check valve 50 receives the hydraulic pressure of the oil flowing toward the third hydraulic cylinder 42 in the deployment path 46 for the third hydraulic cylinder, so the valves in both systems open, opening both the deployment path 46 for the third hydraulic cylinder and the storage path 47 for the third hydraulic cylinder.

[0095] The oil supplied via the deployment path 46 for the third hydraulic cylinder is supplied to the retraction port 422 of the third hydraulic cylinder 42. The third hydraulic cylinder 42 retracts due to the oil supplied to the retraction port 422, and as shown in Figure 4, it pulls the connection part with the link mechanism 423 towards the second boom 32 and deploys the third boom 33.

[0096] Since the connection with the second boom 32 is released by the third boom release step, the third boom 33 can rotate around the vertical axis 331 without being hindered by the third boom deployment prevention mechanism 5.

[0097] Furthermore, in the third hydraulic cylinder 42, oil flows out from the extension port 421 as it contracts. Since the pilot check valve 50 opens the storage path 47 for the third hydraulic cylinder, the oil that flows out from the extension port 421 flows to the storage path branch 451 of the storage path 45 for the second hydraulic cylinder.

[0098] Furthermore, as shown in Figure 4, the switch 491 of the second interlock valve 49 is released when the third boom 33 begins to deploy. As a result, the second interlock valve 49 closes the passage between the storage passage 45 for the second hydraulic cylinder and the second hydraulic cylinder 41. Therefore, the oil that has flowed from the extension port 421 of the third hydraulic cylinder 42 to the storage passage branch 451 flows towards the solenoid valve 43 and is collected in the oil tank 432 via the solenoid valve 43.

[0099] After the third boom 33 is fully deployed, the oil supply from the solenoid valve 43 is stopped, ending the third boom deployment step. This completes the deployment of the side boom 3.

[0100] When the side boom 3 is fully deployed, the pilot check valve 50 can prevent the third boom from unintentionally folding due to vibration, braking, or other factors.

[0101] Specifically, when braking is performed while the boom is fully deployed, an inertial force acts on the third boom 33, causing it to attempt to rotate around the vertical axis 331. In this embodiment, the third boom 33 attempts to move in the direction of retraction.

[0102] However, the pilot check valve 50 acts as a check valve to prevent oil from flowing back from the third hydraulic cylinder 42 because oil is not supplied to both installed paths, thus closing off both paths. As a result, the third hydraulic cylinder 42 is unable to extend or retract, and therefore the third boom 33 is prevented from rotating unintentionally even when inertial forces such as brakes are applied.

[0103] According to this embodiment described above, the following effects can be achieved. 1. The second boom 32 and the third boom 33 can be deployed and retracted (folded) in a series of operations. 2. Since the number of control valves required for deploying and retracting the second boom 32 and the third boom 33 is the same as when it is folded in half, the same solenoid valve 43 can be used as in the case of the folded in half, thereby reducing manufacturing costs. 3. Since there is no need to be aware of the order in which the second boom 32 and the third boom 33 are deployed or retracted, the operator can perform the deployment and retraction operations easily and reliably. 4. By providing a pilot check valve 50 in parallel with the third hydraulic cylinder, rotation of the third boom 33 can be prevented and the deployed state can be maintained even when inertial forces act due to brakes, etc. 5. By folding the third boom 33, the second boom 32, and the first boom 31 in that order, the side boom 3 can be safely folded into three sections. 6. By performing the third boom connection step during the second boom folding step and by providing the third boom deployment prevention mechanism 5, it is possible to prevent the third boom 33 from unintentionally deploying when the second boom 32 is stored or deployed, thereby enabling safe storage and deployment operations.

[0104] Furthermore, the three-fold boom sprayer and the method for folding the three-fold boom according to the present invention are not limited to the embodiments described above and can be modified as appropriate. For example, in this embodiment, the third boom deployment prevention mechanism 5 has a connecting projection 51 installed on the third boom 33 and a projection holding means 52 installed on the second boom 32, but it is not limited to this, and the connecting projection 51 may be installed on the second boom 32 and the projection holding means 52 may be installed on the third boom 33. [Explanation of symbols]

[0105] 1. Tri-fold boom sprayer 2 Center Boom 3 Side Booms 4. Boom folding control mechanism 5. Third boom deployment prevention mechanism T-Towing Vehicle 21 Hydraulic Cylinder 31. First Boom 32. Second Boom 33. The Third Boom 311 Second and third boom support members 312 First Hydraulic Cylinder 313 First opening / closing hydraulic cylinder 321 horizontal axis 331 vertical axis 41. Second hydraulic cylinder 42 Third hydraulic cylinder 43 Solenoid valve 44 Deployment path for the second hydraulic cylinder 45 Storage route for the second hydraulic cylinder 46 Deployment path for the third hydraulic cylinder 47 Storage path for the third hydraulic cylinder 48. First Interlock Valve 49. Second interlock valve 50 Pilot check valve 411 Extension Port 412 Shrinkage port 413 Link Mechanism 421 Extension Port 422 Shrinkage port 423 Link Mechanism 431 Hydraulic pump 432 Oil tanks 433 Solenoid valve control device 434 deployment ports 435 storage ports 481 Switch for the first interlock valve 491 Switch for the second interlock valve 51 Connecting protrusion 52 Protrusion holding means 521 Projection guide groove 522 Projection-holding member 523 Retaining part locking member 524 Inclined guide piece 525 Opening

Claims

1. A three-fold boom sprayer comprising a center boom, a first boom foldably connected to the center boom, a second boom foldably connected to the tip of the first boom, and a third boom foldably connected to the tip of the second boom, A second hydraulic cylinder is positioned at the connection point between the first boom and the second boom, and extends and retracts to deploy and retract the second boom. A third hydraulic cylinder is positioned at the connection point between the second boom and the third boom, and extends and retracts to deploy and retract the third boom. A solenoid valve connected to a hydraulic pump and an oil tank for oil recovery controls the supply of oil to the second and third hydraulic cylinders and controls oil recovery, A deployment path for the second hydraulic cylinder is connected to the solenoid valve and the second hydraulic cylinder, and when the second boom is deployed, it serves as a path for supplying oil to the second hydraulic cylinder. A storage path for the second hydraulic cylinder is connected to the solenoid valve and the second hydraulic cylinder, and when the second boom is retracted, it serves as a path for supplying oil to the second hydraulic cylinder. A deployment path for the third hydraulic cylinder branches off from the deployment path for the second hydraulic cylinder and is connected to the third hydraulic cylinder, and when the third boom is deployed, it becomes a path for supplying oil to the third hydraulic cylinder, A storage path for the third hydraulic cylinder branches off from the storage path for the second hydraulic cylinder and is connected to the third hydraulic cylinder, and when the third boom is retracted, it becomes a path for supplying oil to the third hydraulic cylinder, A first interlock valve is installed in the deployment path for the third hydraulic cylinder, which opens the deployment path for the third hydraulic cylinder only when the second boom is fully deployed, and closes it otherwise. A second interlock valve is installed between the branching section of the storage path for the second hydraulic cylinder and the second hydraulic cylinder, and opens the storage path for the second hydraulic cylinder only when the third boom is fully retracted, and closes it otherwise. The three-fold boom sprayer having the following:

2. A pilot check valve is provided in the path between the first interlock valve and the third hydraulic cylinder in the deployment path for the third hydraulic cylinder, and in the storage path for the third hydraulic cylinder. The aforementioned pilot check valve A three-fold boom sprayer according to claim 1, wherein both paths are opened when hydraulic pressure is received in the direction of the third hydraulic cylinder in either path, and both paths are closed when hydraulic pressure is not received in the direction of the third hydraulic cylinder in either path.

3. The third boom is pivotally supported by a vertical axis at the tip of the second boom, and is configured to be rotatable in a substantially horizontal direction. The second boom is pivotally supported at the tip of the first boom by a horizontal axis perpendicular to the longitudinal direction of the boom, and is configured to be rotatable in a substantially vertical direction. A three-fold boom sprayer according to claim 1 or claim 2, further comprising a third boom deployment prevention mechanism for preventing the third boom from deploying when the tip of the second boom is tilted toward the first boom side beyond the uppermost part of the rotational trajectory.

4. The third boom deployment prevention mechanism is a mechanism that connects the third boom and the second boom, The device comprises a connecting projection that protrudes from one boom towards the other boom, and a projection holding means that holds the connecting projection when the third boom is folded on the other boom. The aforementioned projection holding means is A projection guide groove that guides the connecting projection during the retraction operation of the third boom, A projection holding member having a substantially U-shaped opening into which the connecting projection can be fitted, and which is pivotally supported in a position into which the connecting projection guided by the projection guide groove can be fitted, and which holds the connecting projection in the opening by rotating on its axis while changing the angle of the opening when pushed by the fitted connecting projection, The retaining locking member is configured to be vertically movable, and when the tip of the second boom tilts toward the first boom side beyond the uppermost part of the rotational trajectory, it descends due to its own weight and engages with the projection retaining member, locking the projection retaining member in a non-rotatable state. A three-fold boom sprayer according to claim 3, having a

5. A folding method for a three-fold boom comprising a center boom, a first boom foldably connected to the center boom, a second boom foldably connected to the tip of the first boom, and a third boom foldably connected to the tip of the second boom, A third boom folding step involves rotating the third boom in a substantially horizontal direction and folding it to a position where it is substantially parallel to the second boom, A second boom folding step involves rotating the second boom in a substantially vertical direction and folding it until the tip of the second boom is inclined toward the first boom side, beyond the uppermost part of the rotation trajectory. A first boom folding step involves rotating the first boom in a nearly horizontal direction or diagonally upward from the horizontal, and folding it until the tip faces forward. A method for folding the three-fold boom having the following characteristics.

6. A method for folding a three-fold boom according to claim 5, further comprising a third boom connecting step of connecting the third boom to the second boom so that the third boom does not unfold under its own weight when the tip of the second boom tilts toward the first boom side beyond the uppermost part of the rotational trajectory in the second boom folding step.

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