Spray prevention device

Abstract

The present invention provides a protective device that reduces the labor required for protective measures during grass cutting operations, thereby simplifying the overall work involved in grass cutting. [Solution] A protective device comprising: an extendable device that can be changed between an extended state in which it is extended laterally in the direction of travel relative to the frame and a stored state in which it is folded and stored on the frame; a work section connected to the extendable device for performing ground work; a front leg that can rotate up and down relative to the frame; a rear leg that can rotate up and down relative to the frame; a connecting frame that connects the front leg and the rear leg and links the rotation of the front leg and the rear leg; an extension frame connected to the connecting frame that can be changed between an extended state in which it is extended in the direction of travel relative to the connecting frame and a stored state in which it is folded on the connecting frame; and a protective device equipped with a protective screen provided on the connecting frame and the extension frame.

Description

Technical Field

[0001] This invention relates to a working machine, specifically a working machine that can be detached from the cargo bed or vehicle frame of a vehicle. More specifically, it relates to a protective device for preventing foreign objects from the working part of the working machine.

Background Art

[0002] When working with a grass cutting machine, a cover for the cutting blade is provided to prevent flying objects generated from the cutting blade and the like. However, due to the working characteristics of grass cutting, it is difficult to completely cover the periphery of the cutting blade, so it is necessary to provide a gap between the ground and the cutting blade cover. Therefore, flying objects may be generated from the gap. Especially when doing grass cutting work on roads and the like, it is necessary to prevent flying as much as possible or restrict the movement of flying objects in order to prevent collisions with passing vehicles and pedestrians. To solve this problem, the devices described in Patent Document 1 and Patent Document 2 are known. In Patent Document 1, a protective net is composed of a horizontal member made of support rods, and a movable protective net is formed by the operator suspending the horizontal member with a backpack belt. Also, in Patent Document 2, a flying object prevention device is disclosed in which a shielding body for shielding flying objects is attached to the frame that suspends the wheels in a screen-like manner.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration of Patent Document 1, workers must always support the protective net, and if it is difficult to secure personnel to support the protective net, it becomes difficult to implement the protection itself. Also, in the configuration of Patent Document 2, workers do not need to directly support the protective net or protective device, but personnel are still needed to move the protective device.

[0005] This invention was made in view of the above-mentioned problems, and aims to provide a protective device that can reduce the labor required for protective work during grass cutting and simplify the overall work involved in grass cutting. [Means for solving the problem]

[0006] To solve the above problems, one aspect of the present invention is a protective device comprising: an extendable device that can be changed between an extended state in which it is extended laterally in the direction of travel relative to the frame and a stored state in which it is folded and stored on the frame; a work unit connected to the extendable device for performing ground work; a front leg that can rotate up and down relative to the frame; a rear leg that can rotate up and down relative to the frame; a connecting frame that connects the front leg and the rear leg and links the rotation of the front leg and the rear leg; an extension frame connected to the connecting frame that can be changed between an extended state in which it is extended in the direction of travel relative to the connecting frame and a stored state in which it is folded on the connecting frame; and a protective screen provided on the connecting frame and the extension frame. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a protective device that can reduce the labor required for protective work during grass cutting and simplify the overall work involved in grass cutting. [Brief explanation of the drawing]

[0008] [Figure 1] The diagram shows a side view of the embodiment with the retractable mechanism in a retracted state and the stand device and protective device in a retracted state, with the side panels and protective screen omitted from the illustration. [Figure 2] This is a side view showing the telescopic means according to the embodiment in a retracted state, with the stand device and protective device in a retracted state. [Figure 3] This is a plan view showing the telescopic means in the retractable state and the stand device and protective device in the retracted state according to the embodiment; the protective curtain is omitted from the illustration. [Figure 4] This is a rear view of the embodiment with the retractable means in the retracted state and the stand device and protective device in the retracted state, and the rear tailgate and protective curtain are omitted from the illustration. [Figure 5] This is a side view showing the telescopic means according to the embodiment in an extended state, with the work section moved forward, the stand device in an inclined state, and the protective device in an extended state. [Figure 6] This is a plan view showing the telescopic means according to the embodiment in an extended state, with the work section moved forward, the stand device in an inclined state, and the protective device in an extended state. [Figure 7] This is a rear view showing the telescopic means of the embodiment in the deployed state, with the work section moved forward, the stand device in an inclined state, and the protective device in the deployed state. The rear tailgate and protective curtain are omitted from the illustration. [Figure 8] This is an explanatory diagram illustrating a schematic, enlarged view of the mounting portion of the front leg of the stand device according to the embodiment. [Figure 9] This is a block diagram according to the embodiment. [Figure 10] This is a rear view of the rear wheel showing a modified example according to the embodiment. [Figure 11] This diagram illustrates an example of lowering a frame from a loading platform using a stand device according to an embodiment, where (a) shows the stand device in the retracted position while loaded on the loading platform, (b) shows the inclined position with the stand device rotated to the upright position while loaded on the loading platform, (c) shows the frame lifted off the loading platform with the stand device in the upright position, and (d) shows the frame moving relative to the loading platform with the stand device in the upright position. [Figure 12] This is a cross-sectional view of the lower end of the protective curtain of the protective device according to the embodiment. [Figure 13] This is an enlarged view showing the area around the pivot point of the extension frame of the protective device according to the embodiment. [Modes for carrying out the invention]

[0009] Embodiments of this invention will be described with reference to the drawings. In the illustrations, the left side of the page in the side view will be described as the front relative to the direction of travel, and the right side will be described as the rear relative to the direction of travel. Furthermore, the upper side of the page in the side view will be described as the up, and the lower side will be described as the down. In addition, in the illustrated plan view, the upper side of the page will be described as the right side relative to the direction of travel, and the lower side will be described as the left side relative to the direction of travel.

[0010] First, let me explain the overview of the machine. The stand device H, which is an embodiment of this invention, is detachably mounted on the cargo bed B4 of a vehicle B such as a truck, and is attached to a work machine A that cuts grass and other plants located to the side of the moving vehicle B. The work machine A has a frame D placed on the cargo bed B4 and an extendable mechanism F consisting of multiple booms, and a work section C for cutting grass and other plants at the tip of the extendable mechanism F. The work machine A is configured with the extendable mechanism F and work section C arranged on the frame D, and the stand device H attached to its side.

[0011] The stand device H has a pair of rotatable front and rear legs on the sides of the frame D, and the frame D can be lifted by placing the tips of the front and rear legs on the ground. With the stand device H, the work machine A with the frame D can be detached from the loading platform B4 and loaded onto the loading platform B4 independently. Furthermore, a protective device K is attached to the stand device H. The protective device K blocks the movement of flying debris from the work area C.

[0012] The work unit C can be moved between a stowed state, where the telescopic mechanism F and the work unit C are positioned on the cargo bed B4, and an unfolded state, where the work unit C is positioned to the side of the vehicle B, by rotating the telescopic mechanism F. In the unfolded state, the work unit C can be positioned at any location to the side of the vehicle B by rotating the telescopic mechanism F, allowing for grass cutting work.

[0013] Details of each part will be described. The vehicle B shown in the embodiment is a flat-body freight vehicle having a loading platform B4, and the vehicle size of the freight vehicle B used in the embodiment is about the size of a so-called 2-ton truck. Of course, it is also possible to use vehicle sizes other than the exemplified freight vehicle. The side and rear three sides of the loading platform B4 have a loading prevention plate called the aori B5. The aori B5 includes a rear aori B52 at the rear and side aori B52 located on both sides sandwiching the rear aori B52. The height of the aori B5 in the embodiment will be described as the same for all three sides. In the cabin B1 located in front of the vehicle B, an operator B2 and an operator B3 who is a driver board. The operator B2 operates the operation unit V. Note that the vehicle B in the embodiment performs mowing work while moving forward on the cabin B1 side. Also, the operator B3 who is a driver can also serve as the operator B2 who operates the operation unit V.

[0014] The frame D is a frame that can be detachably loaded on the loading platform B4 of the vehicle B. As shown in FIGS. 1 to 7, the frame D is a member in which long members are combined in a lattice shape. The frame D has a bottom frame D1 that contacts the loading platform B4, a fixing portion D3 for fixing to the loading platform B4, and a support portion D2 that supports the mast frame E and the telescopic means F.

[0015] The bottom frame D1 is arranged on the front side of the loading platform B4. The side frame D4 is a frame assembled upward from the side portion of the bottom frame D1. The fixing portion D3 is located above the side of the bottom frame D1 in the traveling direction and at the upper part of the side frame D4, and is provided higher than the upper end portion of the aori B5. A fastening member D5 such as a rope, a chain, a turnbuckle, or a cargo tightening machine is firmly tied between the fixing portion D3 and the aori B5 or the loading platform B4, and the frame D is integrally fixed to the loading platform B4. In the embodiment, a plurality of fastening members D5 are used and fixed to the side aori B51 on both sides. The support portion D2 is provided at the front end portion of the bottom frame D1, and long members combined in a lattice shape are arranged upward. A first turning shaft E1 directed in the normal direction or the vertical direction with respect to the loading platform B4 surface is arranged on one end side in the left-right direction of the frame D.

[0016] The mast frame E is mounted to the underframe D at a position higher than the tailgate B5 of the vehicle B and the fixing part D3 of the underframe D, so as to be able to pivot horizontally relative to the underframe D. One side of the mast frame E is attached to the first pivot axis E1, allowing the extension / retraction mechanism F and the work section C to pivot horizontally. Since the mast frame E is positioned higher than the tailgate B5 and the fixing part D3, it does not come into contact with the tailgate B5 or the fixing part D3 when it pivots. In addition, it is possible to create a space between the bottom of the mast frame E and the bottom frame D1, which prevents the mast frame E from coming into close proximity to the work section C when the work section C described later is stored. The mast frame E can be driven to pivot around the first pivot axis E1 by the extension and retraction of the first cylinder 11 which is stretched between the support part D2 and the mast frame E. A second pivot axis E2, which is a horizontal axis, is provided on the other side of the mast frame E.

[0017] The boom body, or telescopic means F, is mounted so as to be able to rotate up and down by connecting one end to the second pivot axis E2 of the mast frame E. The telescopic means F is connected to the base frame D and can be extended to extend laterally from the vehicle B. The telescopic means F has a first boom 16, a first connecting body 18, a second boom 17, a second connecting body 19, and a fifth pivot axis E5 which is the front-to-rear axis. The working section C is connected to the second connecting body 19.

[0018] The first boom 16 is mounted so as to be able to pivot up and down relative to the mast frame E, which is provided on the mast frame E at the base of the telescopic means F, with one end connected to the second pivot axis E2. The second boom 17 is mounted so as to be able to pivot up and down relative to the first boom 16, with one end connected to the working section C, which is the other end of the first boom 16. Furthermore, the second boom 17 is mounted so as to be able to pivot in a direction intersecting the pivot direction of the first boom 16. One end of the second connecting body 19 is connected to the other end of the second boom 17.

[0019] The telescopic mechanism F moves the work section C, which is connected to the second connecting body 19, in any direction. The telescopic mechanism F can be stored on the loading platform B4. In the stored state, with the telescopic mechanism F and the work section C positioned on the loading platform B4, the work section C is positioned above the frame D and below the telescopic mechanism F.

[0020] The work unit C is positioned on the other end of the second connecting body 19. In the deployed state shown in Figures 5 to 7, the work unit C can freely rotate up and down around the fifth pivot axis E5, which is a horizontal axis oriented in the front-rear direction and is positioned on the other end of the second connecting body 19. The work unit C can be driven to rotate up and down by the extension and retraction of the fifth cylinder 15 that spans the second connecting body 19 and the work unit C.

[0021] In this embodiment of the invention, the working unit C, as shown in Figures 5 to 7, has a rotor shaft C1, which is a horizontal shaft that rotates in the left-right direction, arranged inside a cover body that is long in the left-right direction. Multiple cutting blades C2 are arranged at intervals in the direction of the rotor shaft C1 and in the direction of rotation of the rotor shaft C1. The cutting blades C2 cut and shred grass and other plants by the rotational drive of the rotor shaft C1.

[0022] The work unit C can be positioned in an deployed state, where it is located to the side of the vehicle B in the direction of travel, by rotating the mast frame E and the telescopic mechanism (boom body) F, and in a retracted state, where it is located on the cargo bed B4, by rotating the mast frame E and the telescopic mechanism F.

[0023] In the telescopic mechanism F, the first boom 16 is a long member that can pivot vertically relative to the mast frame E and the base frame D by a second pivot axis E2, which is a horizontal axis provided on the mast frame E. A second cylinder 12 is positioned above the first boom 16, extending from the upper part of the other end of the mast frame E to the middle part of the first boom 16. The extension and retraction of the second cylinder 12 allows the first boom 16 to be driven to pivot vertically.

[0024] A first connecting body 18 is pivotably connected to the other end of the first boom 16. The first connecting body 18 is pivotable in the vertical direction parallel to the rotation direction of the first boom 16 by a third pivot axis E3, which is a horizontal axis parallel to the second pivot axis located at the tip of the first boom 16. The first connecting body 18 is driven to pivot in the vertical direction by the extension and retraction of a third cylinder 13 that connects the upper middle part of the first boom 16 and one end of the first connecting body 18.

[0025] A second boom 17 is connected to the other end of the first connecting body 18 that is attached to the first boom 16. The second boom 17 is connected to a fourth pivot axis E4, which is a horizontal axis positioned perpendicular to the third pivot axis E3, so that it can pivot freely in the front-rear direction when deployed. The second boom 17 pivots on the fourth pivot axis E4 in a direction perpendicular to the first boom 16 and the first connecting body 18. The second boom 17 is driven to pivot in the front-rear direction around the fourth pivot axis E4 when deployed by a fourth cylinder 14 that spans the other end of the first connecting body 18 and the middle of the second boom 17.

[0026] The second connecting body 19 is positioned at the tip of the second boom 17. The second connecting body 19 is configured so as not to change direction even when the second boom 17 rotates around the fourth pivot axis E4, so that the angle of the working section C does not change even when the second boom 17 is rotated.

[0027] In this embodiment, the power unit M is positioned on the opposite end of the frame D in the left-right direction. That is, it is located on the frame D on the side opposite to the direction in which the work section C is deployed. The power unit M comprises a prime mover M1 consisting of an internal combustion engine, a fuel tank M2, a fluid pressure source M3 that generates fluid pressure by receiving rotational power from the prime mover M1, and a directional control valve M4 that distributes the fluid pressure generated by the fluid pressure source M3 to a motor P1 that rotates each cylinder and rotor shaft C1. As a result, the work machine A of the present invention can be operated by generating power independently without being towed by a vehicle or without drawing power from a vehicle. In this embodiment, the fluid pressure source M3 consists of a hydraulic pump.

[0028] The frame D is equipped with a prime mover M1 and a fluid pressure generator M3 capable of generating fluid pressure using the power of the prime mover M1. The first cylinder 11, second cylinder 12, third cylinder 13, fourth cylinder 14, and fifth cylinder 15 receive the fluid pressure generated by the power unit M and operate the extension / retraction mechanism F. The generated fluid pressure also rotates the rotor shaft C1, thereby rotating the cutting blade C2. The hydraulic pump M3 connected to the prime mover M1 generates hydraulic pressure, which is fluid pressure, by obtaining the rotational power of the prime mover M1.

[0029] In the retracted state, the first boom 16 and the second boom 17 are positioned almost parallel to the surface of the loading platform B4. The telescopic mechanism F consists of a long body, and in the retracted state, the telescopic mechanism F is positioned so as to fold over the loading platform B4 in its long direction. The long directions of the first boom 16 and the second boom 17 that constitute the telescopic mechanism F in the retracted state are oriented in the front-rear direction relative to the direction of travel of the vehicle B. In the retracted state, the work section C is positioned closer to the mast frame E, so uneven loading is less likely to occur on the loading platform B4, and stable loading is possible as the bottom frame D1 makes even contact with the loading platform B4.

[0030] When the telescopic mechanism F is retracted, the work section C in a plan view can be positioned and moved towards the lower central part of the frame D, so that the center of gravity of the work machine A in a plan view can be placed near the center of the frame D.

[0031] When the telescopic mechanism F is retracted, the center of gravity of the entire work machine A can be positioned near the center of the frame D and at a low position on the frame D, allowing for stable loading on the cargo bed B4. During periods when work with work machine A is not being performed, work machine A can be removed from the cargo bed B4, and vehicle B can be operated as a normal cargo vehicle. Vehicle B can be used as both a cargo vehicle and a grass-cutting work vehicle, improving operational efficiency.

[0032] The extended state of the telescopic mechanism F is when the mast frame E is rotated by the first cylinder 11, with the other end facing the side of the vehicle B. In other words, in the extended state, the telescopic mechanism F and the work section C are positioned to the side of the vehicle B. In the extended state, as shown in Figures 5 and 6, the work section C is located right next to the worker B2 riding in the vehicle B, so the worker B2 can easily check the working status of the work section C while working.

[0033] The details of the stand device H are described below. The stand device H comprises a pair of left and right front legs H1 that are rotatable in the vertical middle section on both sides of the support section D2, and a pair of left and right rear legs H2 that are rotatable on the upper part of the left and right side frames D4 behind the front legs H1. Furthermore, it comprises an actuator H3 that connects the support section D2 and the front legs H1 and drives the front legs H1, and a connecting frame H4 that connects the front legs H1 and the rear legs H2. Note that the description refers to the stand device H located on the left side in the direction of travel as shown in the figure, and the description of the stand device H located on the right side in the direction of travel will be omitted as it would be described in the same way repeatedly.

[0034] The front leg H1 has an arm H12 that is rotatably inserted into a pivot point D21 on the side of the support D2, with one end connected to the upper part, and a front wheel H13 that serves as the ground contact point at the lower end of the arm H12. The arm H12 is a long member, and in this embodiment, a square pipe is used. As shown in Figures 11(c) and 11(d), the arm H12 rotates from an upright position facing almost perpendicular to the frame D to a stowed position where the other end is raised upward and rearward at an angle close to horizontal, as shown in Figure 11(a). The pivot point D21 can also be provided on the side frame D4 in addition to the side of the support D2.

[0035] The rear leg section H2 has an arm section H22 that is rotatably inserted into a pivot point D41 located on the upper part of the side frame D4, with one end connected to the upper part, and a rear wheel H23 that serves as the ground contact point at the lower end of the arm section H22. The arm section H22 is a long member of the same length as the arm section H12, and in this embodiment, a square pipe is used, similar to the front leg section H1. As shown in Figures 11(c) and 11(d), the arm section H22 rotates from an upright position facing almost perpendicular to the frame D to a stowed position where the other end is raised upward and rearward at an angle close to horizontal, as shown in Figure 11(a).

[0036] As shown in Figure 8, the pivot axis H11 at the upper end of the arm portion H12 inserted into the pivot point D21 is provided to extend and retract in the left-right direction relative to the pivot point D21. Similarly, the pivot axis H23 at the upper end of the arm portion H22 inserted into the pivot point D41 is provided to extend and retract in the left-right direction relative to the pivot point D41. In other words, the front leg portion H1 and the rear leg portion H2 are rotatable starting from the left-right axis relative to the direction of travel, and are provided to be movable in the axial direction of this left-right axis. The front leg portion H1 and the rear leg portion H2 can rotate vertically while protruding laterally from the pivot point D21 and the pivot point D41. Therefore, the front leg portion H1 and the rear leg portion H2 can rotate vertically without being brought close to the side of the vehicle, including the tailgate B5 and the cargo bed B4. The protruding positions of the pivot axes H11 and H21 relative to the pivot points D21 and D41 may be fixed. Figure 8 shows the front leg H1, but the rear leg H2 is attached in the same way as the front leg H1. In this case, in Figure 8, the front leg H1 should be read as the rear leg H2, the pivot axis H11 as the pivot axis H21, the arm H12 as the arm H22, and the pivot point D21 as the pivot point D41.

[0037] As shown in Figures 1 to 7, wheels are provided at the lower ends of the front leg H1 and the rear leg H2. A rotatable front wheel H13 is attached to the lower end of the front leg H1, and a rotatable rear wheel H23 is attached to the lower end of the rear leg H2. The front wheel H13 and the rear wheel H23 are provided so that they can make contact with the ground G when the front leg H1 and the rear leg H2 are in an upright position, or when they are at an inclination angle that is approximately close to the upright position. The front wheel H13 and the rear wheel H23 used in this embodiment are caster wheels that are also rotatable in the horizontal direction when in an upright position.

[0038] The front wheel H13 and rear wheel H23 are described as caster wheels that can rotate horizontally, but this is not necessarily the case. For example, wheels that cannot rotate horizontally may also be used. Alternatively, for example, a wheel that can rotate horizontally may be used for the front wheel H13 and a wheel that cannot rotate horizontally may be used for the rear wheel H23. The combination of these wheel configurations and the number of each used can be freely changed as appropriate depending on the conditions of use.

[0039] The front wheel H13 and rear wheel H23 can also be considered contact points that can make contact with the ground G through the rotation of the front leg H1 and rear leg H2. The lengths of the front leg H1 and rear leg H2, including the contact points, are set to be longer than the distance from the ground G to the loading platform B4. The distance from the ground G to the pivot axis H11 is longer than the distance from the front wheel H13, which is the contact point, to the pivot axis H11 via the arm H12. Also, the distance from the ground G to the pivot axis H21 is longer than the distance from the rear wheel H23, which is the contact point, to the pivot axis H11 via the arm H22.

[0040] With the frame D installed on the loading platform B4, if the front legs H1 and rear legs H2 are moved to an upright position, and the front wheels H13 and rear wheels H23 remain on the ground, then rotating the front legs H1 and rear legs H2 further toward the upright position will allow the frame D to be lifted off the loading platform B4. When lifting the frame D off the loading platform B4, the fastening member D5 that secures the frame D to the loading platform B4 is released.

[0041] An actuator H3 is provided on the frame D. By operating the actuator H3, the arm portion H12 of the front leg portion H1 is rotated. In this embodiment, the actuator H3 is a hydraulic cylinder, which is a cylinder that expands and contracts with fluid pressure. One end of the actuator H3 is connected to the upper part of the support portion D2 of the frame D, and the other end is connected to the upper rear side of the arm portion H12. The actuator H3, being a hydraulic cylinder, expands and contracts with pressure obtained from the fluid pressure generation source M3 of the power unit M via the directional control valve M4, thereby enabling the rotation of the front leg portion H1. In this embodiment, shortening the actuator H3 raises the front leg portion H1 to the stowed position, and extending it lowers the front leg portion H1 to the upright position. Also, as best shown in Figure 7, the support shaft H31 that rotatably supports the upper end of the actuator H3 is provided so as to be able to move in and out of the support portion D2. The actuator H3 is also provided so that when the front leg H1 and rear leg H2, described later, are pulled away from the frame by the pivot axis H31, the actuator H3 can also be moved away from the front leg H1 and rear leg H2 together. The dashed line in Figure 7 represents the pivot axis H11 and support axis H31 when the front leg H1 and actuator H3 are moved toward the frame D. Although not shown, the pivot axis H21 of the rear leg H2 also moves relative to the frame D in the same way as in Figure 7.

[0042] Actuator H3 may be a cylinder that uses electricity as its direct power source, in addition to the configuration described. For example, it may be an actuator that charges a battery (not shown) with electricity generated by the power unit M and operates using the electricity obtained from the battery. Furthermore, actuator H3 is not limited to a cylinder but may be a motor, and may be configured to convert the rotational power of the motor into the rotational motion of the front leg H1. In this case, the rotational power may be transmitted between the motor and the front leg H1 via a transmission mechanism.

[0043] The actuator H3 is operated by the control unit V. The control unit V is equipped with an operating part (not shown) that allows for manual operation of the actuator H3, and the actuator H3 performs operations in response to the manual operation by the operator B2 at the operating part. In this embodiment, the cylinder, which is the actuator H3, extends or retracts in response to the operation of the control unit V. The operation signal from the control unit V is transmitted to the control unit J, which drives the directional control valve M4, thereby driving each cylinder, motor P1, and actuator H3. The control unit V and the control unit J may be connected by wire or wireless connection. In this embodiment, the control unit V is connected to the control unit J by wireless connection. There are no limitations on the communication format for wireless connection. Any format that can communicate the operation status and amount of operation of the control unit V to the control unit J is acceptable, and can be freely selected and adopted as appropriate.

[0044] The intermediate section of the arm section H12 of the front leg section H1 and the intermediate section of the arm section H22 of the rear leg section H2 are connected by a connecting frame H4. The connecting frame H4 is a long, rod-shaped member in the front-rear direction, with connecting sections H41 at both ends. The connecting sections H41 allow the connecting frame H4 to rotatably connect to the arm sections H12 and H22. Therefore, the rear leg section H2 can rotate up and down at the same angle as the front leg section H1, which rotates up and down in response to the operation of the actuator H3. The front leg section H1 and the rear leg section H2 operate in conjunction with each other from the upright position to the stowed position.

[0045] As best shown in Figure 8, the pivot points D21 and D41 are equipped with sensors H5 capable of detecting the lateral separation distance between the pivot axes H11 and H21, which are the left and right axes, and the pivot points D21 and D41. Sensor H5 detects the amount of protrusion of the front leg H1 and rear leg H2 relative to the pivot points D21 and D41 located on the side frame 4. In this embodiment, sensor H5 is a photoelectric sensor and sends a separation signal to the control unit J when the front leg H1 and rear leg H2 move beyond a predetermined distance relative to the pivot points D21 and D41.

[0046] Upon receiving the separation signal, the control unit J issues a permission signal that allows the directional control valve M4 to drive the corresponding valve for operating the actuator H3. When the permission signal is issued, operating the operating part of the operating unit V to operate the actuator H3 will cause the actuator H3 to operate. In other words, the front leg H1 and rear leg H2 are configured so that they cannot rotate even if operated by the operating unit V unless they are separated from the side frame D4 by a predetermined distance or more. With the above configuration, the front leg H1 and rear leg H2 can rotate while being sufficiently far from the tailgate B5 of vehicle B, thereby preventing interference with vehicle B, including the tailgate B5.

[0047] Here, using Figure 11, the procedure for lowering the work machine A from the loading platform B4 using the stand device H will be explained. First, the fastening member D5 is removed to release the fixation between the frame D and the loading platform B4. Next, the front legs H1 and rear legs H2, which are in the stowed position, are moved to the side away from the side frame D4, and away from the loading platform B4. Then, the operator operates the control unit V to activate the actuator H3 in the direction that the front legs H1 and rear legs H2 will be in the upright position, rotating them from the state shown in Figure 11(a) to the state shown in Figure 11(b). At this time, the actuator H3 will not operate unless the axial separation condition of the front legs H1 and rear legs H2 is met by the sensor H5, so it is necessary to separate the front legs H1 and rear legs H2 from the side frame D4 until the separation condition is met.

[0048] As the front legs H1 and rear legs H2 rotate toward the upright position, the front wheels H13 and rear wheels H23 eventually make contact with the ground G, as shown in Figure 11(b). This is an inclined state, just before the upright position, but the frame D is not lifted off the loading platform B4. While in the inclined state, the control unit V is operated to activate actuator H3, which moves the front legs H1 and rear legs H2 toward the upright position. As a result, the front legs H1 and rear legs H2 rotate so as to press the front wheels H13 and rear wheels H23 against the ground G, achieving a fully upright position, and the frame D lifts off the loading platform B4, as shown in Figure 11(c). In other words, the work machine A is no longer loaded on the loading platform B4. In this state, the work machine A is moved relative to the vehicle B, as shown in Figure 11(d). For example, worker B3 may drive vehicle B forward, or another worker may move the work implement A, which is in contact with the ground G, to the rear of vehicle B. In this way, the work implement A, including the frame D, is separated from vehicle B.

[0049] The procedure for loading work equipment A onto the loading platform B4 is the reverse of the unloading procedure described above, using the stand device H.

[0050] Since the stand device H has front wheels H13 and rear wheels H23, it can be easily moved even when the work machine A is pushed by an operator while it is on the ground. Furthermore, since the front legs H1 and rear legs H2 of the stand device H are configured to move in the axial direction of the pivot axes H11 and H21, it is possible to prevent contact between the front legs H1 and rear legs H2 and the vehicle B when moving them separately from the vehicle B. This configuration also prevents contact with the vehicle B when the front legs H1 and rear legs H2 rotate between the stowed position and the upright position. In addition, the sensor H5 can detect the distance between the front legs H1 and rear legs H2 and the frame D, so it is possible to avoid contact with the vehicle B when the front legs H1 and rear legs H2 rotate up and down.

[0051] In this embodiment, the arm sections H12 and H22 were described as a single long member, but they may be composed of multiple members. Furthermore, the arm sections H12 and H22 may be provided to be extendable and retractable in the longitudinal direction. The extension / retraction mechanism is not limited in this case; for example, a mechanism using the extension / retraction motion of a cylinder, or a mechanism utilizing the axial movement of the screw caused by the rotation of the male and female screws, may be used. This can be appropriately selected according to the specifications of the implementation.

[0052] Furthermore, a motor H6 for driving the wheels may be attached to either or each of the front wheel H13 and / or rear wheel H23. Figure 10 shows a modified example in which the motor H6 is attached to the rear wheel H23. In this case, the rear wheel H23 is preferably a wheel that omits the horizontal rotation mechanism. The motor H6 may be operated by fluid pressure obtained from the fluid pressure source M of the power unit M, or it may be operated by electrical energy obtained from the power unit M. For example, it may be an electric motor that charges a battery (not shown) with electricity generated by the power unit M and operates using the electricity obtained from the battery. Furthermore, the motor H6 may be operated by obtaining energy from a source other than the power unit M. The motor H6 may be attached to the front wheel H13, or to both the front wheel H13 and the rear wheel H23.

[0053] The frame D can move under its own power thanks to the stand device H to which the motor H6 is attached. The motor H6 is driven by the control unit J and the operating unit V, which controls forward and backward movement and left and right steering, so that the frame D to which the stand device H is attached can be moved freely. Therefore, attaching and detaching the frame D to the vehicle B becomes even easier. Also, because it is driven by the motor H6, even if heavy objects such as the telescopic mechanism F, the work unit C, and the power unit M are fixed to the frame D to which the stand device H is attached, the frame D can be easily moved on the ground G.

[0054] The front legs H1 and rear legs H2 of the stand device H are positioned to be close to the frame D when in the stowed position. This means that even when vehicle B is moving when not in operation, the stand device H can travel on the road without interfering with normal driving. Conversely, when in the upright position, the front legs H1 and rear legs H2 of the stand device H are provided to be movable laterally so as to be separated from the frame D. This makes it possible to load the frame D onto vehicle B and unload it from vehicle B while avoiding interference with the tailgate B5 and the securing member D5.

[0055] Further embodiments will be described. A protective device K may be attached to the connecting frame H4. The protective device K is a device that prevents flying debris from moving towards the vehicle B side when it is scattered from the work area C. The protective device K comprises an extension frame K1 that can rotate up and down at the front end of the connecting frame H4, a curtain-like protective curtain K2 that is attached so as to hang down from the connecting frame H4 and the extension frame K1, and a motor K31 that rotates the extension frame K1 relative to the connecting frame H4.

[0056] The extension frame K1 is a long, rod-shaped member that extends in the front-rear direction, and its rear end is rotatably mounted on a pivot point H41 located on the front end of the connecting frame H4. The pivot point H41 is located above the connecting frame H4 and above the connecting part H41. The extension frame K1 can be rotated to the front of the connecting frame H4 to be unfolded parallel to its longitudinal direction, as shown in Figure 5, and rotated to the rear of the connecting frame H4 to be folded above the connecting frame H4, as shown in Figure 2.

[0057] As shown in Figures 5 and 6, when the front legs H1 and rear legs H2 of the stand device H are in an upright position or an inclined position slightly backward from the upright position, the front end of the extended frame K1 in its extended state is located in front of the front end of the cabin B1. Also, as shown in Figures 1 and 2, when the front legs H1 and rear legs H2 are in a retracted position, the rear end of the retracted extended frame K1 is located behind the rear legs H2 and behind the rear end of the underframe D.

[0058] When the front legs H1 and rear legs H2 are in the retracted position, the tip of the extended frame K1 in the extended position is located behind the front end of the cabin B1. Also, when the front legs H1 and rear legs H2 are in the upright position or in an inclined position slightly backward from the upright position, the rear end of the extended frame K1 in the retracted position is located behind the rear end of the underframe D and above the rear wheel H23.

[0059] A protective screen K2 is provided on the connecting frame H4 and the extension frame K1. The protective screen K2 is a screen-like member that hangs down from the connecting frame H4 and the extension frame K1. The upper part of the protective screen K2 is suspended at intervals from multiple points on the connecting frame H4 and the extension frame K1. In this embodiment, the protective screen K2 is a mesh-like member with mesh openings of about 1 mm. The protective screen K2 can be any mesh-like curtain with fine mesh openings of about 0.1 to 2.0 mm. Alternatively, a curtain without mesh may also be used.

[0060] The protective screen K2 is positioned from the front end of the extended frame K1 in its deployed state to the rear end of the connecting frame H4. The lower end of the protective screen K2 is positioned so that it contacts the ground when at least the front wheels H13 and rear wheels H23 are in contact with the ground. Furthermore, the height of the protective screen K2 may be made longer than the length mentioned above. In this way, the lower end can always be made in contact with the ground G in response to unevenness, and the front legs H1 and rear legs H2 can be made to make sufficient contact with the ground G even when rotated above the upright or inclined position.

[0061] Weight members K21 are provided at the lower end of the protective curtain K2. The weight members K21 are flat plates and are provided at multiple locations distributed at the lower end of the protective curtain K2. In this embodiment, as shown in Figure 12, six metal weight members K21 made of iron are provided at six locations within a space formed by rolling up the lower end of the protective curtain K2 into a bag shape. However, the number and positions of the weight members can be any number, and the material can be other metals, or non-metallic materials such as wood or resin. Alternatively, a chain-like member may be provided as the weight K21. In this case, even if the length of the chain-like member is set to be the same as the front-to-back length of the protective curtain K2, the chain itself can be freely deformed, so it does not hinder the bending of the protective curtain K2. The weight members K21 have the effect of pulling the protective curtain K2 downward in the direction of gravity. Therefore, it is possible to prevent the protective performance from decreasing due to the protective curtain K2 curling up upwards during use.

[0062] A grounding member K22 is positioned at the lower end of the protective screen K2. The grounding member K22 is a brush-shaped member that is long in the direction of travel and flexible. In this embodiment, it is positioned to follow the flexible lower end of the protective screen K2. In other words, the grounding member K22 can bend integrally with the flexible protective screen K2. Therefore, the grounding member K22 can be positioned to effectively fill the gap between the lower end of the protective screen K2 and the ground G, thereby improving the protective performance at the lower end of the protective screen K2. In this embodiment, the grounding member K22 is provided integrally to correspond to the length of the weight member K21, but multiple grounding members can also be provided separately in the direction of travel.

[0063] As best shown in Figure 13, the motor K31 is positioned near the connecting portion H41 of the connecting frame H4 and rotates the extension frame K1 between the retracted and extended states. In this embodiment, the extension frame K1 and the motor K31 are connected via a transmission mechanism K32 consisting of a gear mechanism. The transmission mechanism K32 allows the power of the motor K31 to be varied, making it possible to rotate the extension frame K1 even with a small amount of power. However, the output may be adjusted and the motor K31 may be directly connected to and driven by the extension frame K1. Furthermore, the transmission mechanism K32 does not have to be a gear mechanism.

[0064] The motor K31 is driven by a human operator using the control unit V. By operating the control part of the control unit V corresponding to the motor K31, the motor K31 can be driven in forward and reverse directions, and the extension frame K1 can be deployed or retracted. Therefore, by operating the control unit V, it is possible to change the state between a deployed state in which the protective curtain K2 is deployed in the direction of travel and a retracted state in which the extension frame K1 is positioned above the connecting frame H4 and the protective curtain K2 is folded. It can also be said that the protective curtain K2 is designed so that its length in the front-to-back direction, which is the direction of travel, can be arbitrarily changed by operating the control unit V. In this embodiment, the control unit J, which receives a separation signal from the sensor H5, issues a permission signal. When the permission signal is issued, the motor K31 is activated when the control part of the control unit V is operated.

[0065] There are no limitations on the type of motor K31. In this embodiment, the power generated by the power unit M charges a battery (not shown), and the motor operates using the power obtained from the battery. Alternatively, a fluid pressure motor utilizing the fluid pressure generated by the fluid pressure source M3 of the power unit M may also be used. Furthermore, a cylinder mechanism may be used instead of a motor.

[0066] As mentioned above, the front end of the extended frame K1 in its deployed state is located in front of the front end of the cabin B1, so the front end of the protective screen K2 in its deployed state is also located in front of the front end of the cabin B1, and the rear end of the protective screen K2 is located at the rear end of the connecting frame H4. The deployed protective screen K2 is positioned with a front-to-back distance that is even longer than the distance traveled by the work section C, which moves back and forth by the operation of the second boom 17. Therefore, even if the work section C is deployed to the side of the vehicle B and the work section C is moved back and forth by the second boom 17, the side of the work section C can be shielded in a side view. Not only the side of the work section C on the vehicle B side, but also the diagonal front-to-back position on the side of the work section C on the vehicle B side can be shielded, so flying debris from the work section C to the front-to-back and diagonal side of the vehicle B side can be shielded.

[0067] Furthermore, the grounding member K22 can fill the gap between the lower end of the protective screen K2 and the ground G, effectively preventing debris from passing through from the lower end of the protective screen K2. In addition, since the grounding member K22 itself can be freely flexible, it can effectively shield uneven areas even on uneven ground G.

[0068] Furthermore, the weight member K21 pulls the protective screen K2 downward in the direction of gravity, allowing the ground contact member K22 to be effectively grounded. Therefore, it is possible to suppress flying debris from passing under the protective screen K2 and prevent flying debris from reaching vehicle B.

[0069] Since the front legs H1 and rear legs H2 are rotatable, the protective screen K2 can also be moved vertically. Because the height of the loading platform B4 of the work machine A, including the frame D, varies depending on the vehicle B being loaded, the vertical height of the protective screen K2 can be freely changed by rotating the front legs H1 and rear legs H2.

[0070] If the protective screen K2 is not to be used after the work is completed, worker B2 operates the control unit V to activate the motor K31, which changes the protective screen K2 to its retracted state and stores it away. Furthermore, the legs H1 and rear legs H2 are rotated upward to a height sufficient to prevent the ground contact member K22 at the lower end of the protective screen K2 from touching the ground. In other words, the stand device H is placed in its retracted position. With the vehicle in this position and the telescopic mechanism F retracted, the work unit C is positioned on the loading platform B4, allowing the vehicle B to move freely.

[0071] The operation method of work machine A when using protective device K will be explained. First, when the telescopic means F is in the retracted state, the front leg H1 and rear leg H2 of the stand device H, which are in the retracted state, are moved to the side and outward. Then, based on the detection signal from sensor H5, the control unit J gives permission to operate actuator H3 and motor K31, enabling operation at the control unit V. Next, the control unit V is operated to drive actuator H3 and rotate the front leg H1 and rear leg H2 toward the upright position. Then, the arms H13 and H23 are moved to the inclined position shown in Figure 11(b) such that the front wheel H13 and rear wheel H23 are touching the ground G or slightly floating above the ground G, while the front leg H1 and rear leg H2 are in the inclined state before they are in the fully upright position. Next, the control unit V is operated to activate motor K31 and rotate the retracted extension frame K1 toward the deployed state. At this time, the upper part of the protective screen K2 is fixed so that it hangs down from the connecting frame H4 and the extension frame K1, so the protective screen K2 also unfolds in accordance with the rotation of the extension frame K1.

[0072] After deploying the protective screen K2, the retractable mechanism F, which is in its retracted state, is operated by the operating unit V, and the work unit C is deployed to the side of the vehicle B. The deployed protective screen K2 is positioned so that it is sandwiched between the work unit C, which is in its deployed state by the retractable mechanism F, and the vehicle B. Therefore, when working with the work unit C, any debris that may be scattered from the cutting blade C2 into the surrounding area is blocked by the protective screen K2, preventing it from moving at least beyond the protective screen K2 towards the vehicle B. To switch the protective device K from the deployed state to the retracted state, the operating unit V is operated in the reverse order of the procedure for deploying it as described above.

[0073] The weight member K21 prevents the protective curtain K2 from swaying due to wind or other environmental factors when it is deployed from its stored state to its deployed state, enabling stable deployment of the protective curtain K2. Furthermore, the grounding member K is positioned to fill the gap between the lower end of the protective curtain K2 and the ground G, effectively preventing the protective curtain K2 from moving from the lower end towards the vehicle B.

[0074] Furthermore, the relative position of the second boom of the deployed work unit C to the front and rear of vehicle B can be any position. Regardless of the front and rear position of the work unit C, the protective screen K2 can perform its function of preventing the scattering of debris. The front and rear ends of the protective screen K2 only need to be located in front of and behind the front and rear ends of the work unit C when viewed from the side.

[0075] The protective device K does not necessarily have to have all the components of the stand device H. For example, the front wheels H13 and rear wheels H23 of the stand device H may be omitted. The actuator H3 may also be omitted. In this case, the protective curtain K2 is moved up and down by manually rotating the front legs H1 and rear legs H2. Furthermore, the protective device K has been described as being installed on the stand device H. The protective device K may be installed on both sides of the pair of stand devices H located on both sides of the vehicle B, or on only one side, and can be appropriately selected and modified depending on the applicable form. In addition, when implementing a protective device K that does not have all the components of the stand device H, the sensor H5 may be omitted. The extension frame K1 of the protective device K can be changed between the deployed and retracted states by rotating it upward relative to the connecting frame H4, but it is also possible to change between the deployed and retracted states by rotating the extension frame K1 laterally relative to the connecting frame H4. The longitudinal lengths of extension frame K1 and connecting frame H4 are as described, but they are not limited to these lengths and can be changed to the optimal length as needed, and their relative position to vehicle B can also be changed as needed.

[0076] As described above, the embodiments are described, but the stand device H and the protective device K can be implemented independently or simultaneously. Furthermore, although the stand device H and protective device K were described as being installed on a work machine A having a frame D that can be loaded onto a loading platform B4, they can be implemented even if all or at least one of the telescopic means F, work section C, and mast frame E of the work machine A are omitted. In other words, the stand device H and protective device K can be implemented as long as there is a frame D.

[0077] Furthermore, although the frame D has been described as being loaded onto the cargo bed B4, it may also be directly attached to one or more sides of the vehicle B, either front or rear, left or right. In this case, the bottom frame D1 may be omitted. Additionally, a lifting device may be provided on one of the sides of the vehicle B, either front or rear, and the frame D may be connected via this lifting device. Furthermore, the frame D may be connected to the lifting device via a rapid coupling mechanism.

[0078] The descriptions and drawings forming part of this disclosure are for the purpose of briefly illustrating the present invention and do not limit it. Modifications of embodiments, examples and operational techniques based on this disclosure are permitted within the scope set forth in the claims. [Explanation of Symbols]

[0079] A: Work machine, B: Vehicle, B1: Cabin, B4: Cargo bed, B5: Side panels, C: Work section, D: Frame, E: Mast frame, F: Telescopic mechanism, G: Ground, H: Stand device, H1: Front leg section, H11: Pivot axis, H12: Arm section, H13: Front wheel, H2: Rear leg section, H21: Pivot axis, H22: Arm section, H23: Rear wheel, H3: Actuator, H4: Connecting frame, H41: Connecting section, H42: Rotation pivot section, H5: Sensor, K: Protective device, K1: Extension frame, K2: Protective screen, K21: Weight member, K22: Ground contact member, K31: Motor

Claims

1. An extendable device that can be switched between an extended state, where it is extended laterally in the direction of travel relative to the frame, and a stored state, where it is folded and stored on the frame, A work unit connected to the aforementioned telescopic device for performing work on the ground, The front leg portion is rotatable vertically relative to the frame, The rear leg portion is rotatable vertically relative to the aforementioned frame, A connecting frame that connects the front leg portion and the rear leg portion and links the rotation of the front leg portion and the rear leg portion, An extension frame connected to the aforementioned connecting frame, which can be changed between an extended state where it is unfolded in the direction of travel relative to the connecting frame and a stored state where it is folded on the connecting frame, The protective screen provided on the connecting frame and the extension frame, A protective device characterized by being equipped with the following features.

2. The lower part of the protective screen has a grounding member that makes contact with the ground and fills the gap between the lower edge of the protective screen and the ground, The protective device according to claim 1, characterized by comprising:

3. The connecting frame is movable vertically in conjunction with the rotation of the front and rear legs. The protective device according to feature 2.

4. The extension frame is movable vertically in conjunction with the rotation of the front and rear legs. That is, The protective device according to feature 2.

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