Excavator equipped with fall prevention device

Abstract

To prevent crops from falling forward from a digging machine.SOLUTION: A digging machine 4 including a machine frame 17 liftably / lowerably connected to a traveling vehicle 2 by a lifting link mechanism 3, and a digger 20 provided in front of the machine frame 17, includes a fall prevention device 110 with a fall prevention member 111 when the digging machine 4 moves forward together with the traveling vehicle 2 and the digging machine 4 is lifted from a working posture of digging crops with the digger 20, prevents the crops 16 located in the digger 20 and remaining in the digging machine 4 from falling forward from the digger 20.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an excavator equipped with a fall prevention device. [Background technology]

[0002] BACKGROUND ART Conventionally, an excavator disclosed in Patent Document 1 is known.

[0003] The digger disclosed in Patent Document 1 has a digging tool attached to the front of the machine frame, and as the machine frame moves forward, the digging tool digs up crops grown in the field. The crops dug up by the digging tool are transported rearward by an endless rotor attached to the rear of the digging tool. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-185846 Summary of the Invention [Problem to be solved by the invention]

[0005] When using the above-mentioned digger to dig up crops, the vehicle to which the digger is connected, such as a tractor, moves forward with the digger lowered. This allows the blade-like digging tool attached to the lower front end of the digger to penetrate into the soil, digging up crops such as onions while cutting their roots. When the digger reaches the end of the furrow, the vehicle lifts the digging tool upward and turns around with the tool off the ground so that it can dig up crops in a new furrow.

[0006] However, if the dug-up crop remains in the digger before the implement performs the turning operation, the dug-up crop may roll and fall out the front of the digger.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a digger equipped with a fall prevention device that can prevent crops from falling forward from the digger. [Means for solving the problem]

[0008] the digger is a digger comprising a machine frame connected to a traveling vehicle by a lifting link mechanism so as to be able to rise and fall, and a digging tool provided at the front of the machine frame, and a fall prevention device provided with a fall prevention member that is positioned on the digging tool to prevent crops remaining in the digger from falling forward from the digging tool when the digger moves forward together with the traveling vehicle and is lifted from a working position in which the digging tool digs up crops; a position changing device that changes the position of the fall prevention member between a fall prevention position, which is the position when the digger is lifted, and a retracted position, which is a position retracted from the fall prevention position and is a position that allows the digging up of the crops; Equipped with The position change device includes a support body to which the fall prevention member is attached and which is supported on the excavation machine so as to be able to swing freely around an axis extending in the width direction of the excavation machine, and a linkage member which links the support body to a change in the attitude of the excavation machine or the swing of the lifting link mechanism so as to swing the support body and change the position of the fall prevention member between the fall prevention position and the retracted position.

[0012] The support body may include a base member connected to the excavator, a tip member connected to the fall prevention member, a swing shaft that pivots the tip member so that it can swing freely relative to the base member, and a regulating device that allows the tip member to swing rearward beyond a predetermined position and prevents the tip member from swinging forward beyond the predetermined position.

[0013] The fall prevention device may include a biasing member that biases the tip member relative to the base end member in a direction in which the tip member swings forward relative to the base end member.

[0014] The tip member includes a first member connected to the fall prevention member, a second member pivotally supported on the swing shaft, and a first member pivotally supported on the swing shaft so that the distance from the first member to the second member is freely changeable. and a connecting portion that connects the first member to the second member, and the length of the support body from the base end to the tip end may be freely changed by the connecting portion. [Effects of the Invention]

[0015] According to the digger equipped with the fall prevention device, the crops can be prevented from falling forward from the digger. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 2 is a side view of the working machine with the excavator in a first position. [Figure 2] FIG. 2 is a side view of the excavator in a first position. [Figure 3] FIG. 2 is a side view of the excavator in a second position. [Figure 4] FIG. 2 is a plan view of a machine frame on which a fall prevention device is provided. [Figure 5] FIG. 4 is a side view of the attitude adjustment mechanism when the excavator is in a first attitude. [Figure 6] FIG. 10 is a side view of the attitude adjustment mechanism when the excavator is in a second attitude. [Figure 7] FIG. 10 is a side view of the attitude adjustment mechanism when the excavator is in a third attitude. [Figure 8] 1A is a plan view of the mechanism for guiding the crops when the width for guiding the crops is narrowed, and FIG. 1B is a plan view of the mechanism for guiding the crops when the width is widened. [Figure 9] 6 is a cross-sectional view of the attitude adjustment mechanism taken along line Z1-Z1 in FIG. 5. [Figure 10] FIG. 10 is a top view of the attitude adjustment mechanism, showing the structure of a regulating member in cross section. [Figure 11] FIG. 2 is a perspective view of the fall prevention device as seen from the front left. [Figure 12] 10A to 10C are diagrams illustrating a procedure for adjusting the width of the fall prevention member using the width adjustment mechanism. [Figure 13] 10 is a side view showing a mechanism for swinging the fall prevention member by an interlocking member. FIG. [Figure 14] 10 is a side view showing a comparison between a fall prevention device in which the fall prevention member is in the fall prevention position and a fall prevention device in which the fall prevention member is in the retracted position. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate.

[0018] 1 shows a schematic side view illustrating the overall configuration of a work machine 1 (ground work machine). The work machine 1 has a tractor 2, which is exemplified as a traveling vehicle (traveling body), and an excavator 4 attached to the rear of the tractor 2 via a lifting link mechanism 3. Note that the traveling vehicle does not have to be the tractor 2.

[0019] In this embodiment, the direction indicated by arrow A1 in Figure 1 (the forward direction of tractor 2) will be referred to as the front, the direction indicated by arrow A2 (the reverse direction of tractor 2) will be referred to as the rear, and the direction indicated by arrow A3 will be referred to as the fore-and-aft direction.

[0020] Furthermore, the horizontal direction (left-right direction) that is perpendicular to the fore-and-aft direction A3 will be described as the machine width direction K1 (see Figure 4). The machine width direction K1 is the width direction of the excavator 4 (machine frame 17). A direction from the widthwise center of the work implement 1 (digger 4) to the right or left will be described as the outward side of the machine width direction K1 (machine widthwise outward). In other words, the machine widthwise outward direction is a direction that moves away from the widthwise center of the work implement 1 (digger 4) in the machine width direction K1. The direction opposite to the machine widthwise outward direction will be described as the inward side of the machine width direction K1 (machine widthwise inward). In other words, the machine widthwise inward direction is a direction that moves closer to the widthwise center of the work implement 1 (digger 4) in the machine width direction K1.

[0021] As shown in FIG. 1, the tractor 2 has a body 9 supported for travel by left and right front wheels (not shown) and left and right rear wheels 5. The tractor 2 may be equipped with crawlers instead of wheels. A driver's seat 30 for an operator (driver) is provided at the rear of the body 9. A hydraulic unit 6 is also mounted at the rear of the body 9. Lift arms 7 are provided on the left and right sides of the hydraulic unit 6. The lift arms 7 are rotatable about axes extending in the machine width direction K1 and are driven by hydraulic force from the hydraulic unit 6 to swing upward. When the hydraulic force from the hydraulic unit 6 is released, the lift arms 7 swing downward. A top link bracket 8 is provided at the rear of the hydraulic unit 6. A PTO shaft 10, which is a power take-off shaft that takes off rotational power, is provided at the rear of the body 9.

[0022] As shown in FIG. 1, the lifting link mechanism 3 in this embodiment is a three-point link mechanism. The three-point link mechanism 3 has one top link 11 and a pair of lower links 12 arranged below the top link 11 at a distance in the machine width direction K1. The front portion of the top link 11 is connected (pivoted) to the top link bracket 8 so as to be rotatable about an axis extending in the machine width direction K1. The front portion of the lower link 12 is connected (pivoted) to the side of the vehicle body 9 so as to be rotatable about an axis extending in the machine width direction K1. The middle portion of the lower link 12 is connected to the rear portion of the lift arm 7 by a lift rod 13.

[0023] The rear of the top link 11 and the rear of the lower link 12 are connected to the digger 4 so as to be rotatable about an axis extending in the machine width direction K1. Therefore, the digger 4 is connected to the rear of the tractor 2 via the lifting link mechanism 3 so as to be able to rise and fall, and is raised and lowered by the hydraulic device 6. In detail, when the lift rod 13 swings upward, the top link 11 and the lower link 12 move upward and the digger 4 rises, and when the lift rod 13 swings downward, the top link 11 and the lower link 12 move downward and the digger 4 descends. The vertical stopping position of the digger 4 can be adjusted as desired by the hydraulic device 6.

[0024] As shown in Figure 2, the digger 4 is a work machine (onion digger) that digs up crops 16 (e.g., onions) grown in a field 14 (ridges 15) using a digging tool 20 and transports the dug-up crops 16 rearward (upward and rearward) using a transport body 25.

[0025] 1 and 4, the excavator 4 has a machine frame 17. The machine frame 17 has a mounting frame 21 connected to the three-point linkage 3, a transmission case 22 fixed to the mounting frame 21, a pair of support arms 23 provided on the left and right sides of the transmission case 22 (on both sides in the machine width direction K1), a pair of side frames 18 arranged at an interval in the machine width direction K1 to sandwich the transmission case 22 and the pair of support arms 23, and a connecting frame 19 connecting the rear portions of the pair of side frames 18 together.

[0026] The mounting frame 21 has a pair of fixing plates 26 bolted to the left and right surfaces of the transmission case 22, an upper frame 27 extending in an inclined direction that becomes upward as it moves forward from between the pair of fixing plates 26, a pair of lower frames 28 extending forward from each of the pair of support arms 23, a first connecting plate 29L connecting the upper frame 27 to one (left) lower frame 28, a second connecting plate 29R connecting the upper frame 27 to the other (right) lower frame 28, and a connecting body 32 connecting the pair of lower frames 28 to each other.

[0027] The transmission case 22 is disposed at the center of the machine frame 17 in the width direction (machine width direction K1). An input shaft 24 is provided in the transmission case 22 so as to protrude forward. The input shaft 24 is connected to the PTO shaft 10 of the tractor 2 via a joint shaft (universal joint). Power from the PTO shaft 10 is taken into the transmission case 22 via the input shaft 24.

[0028] One of the support arms 23 (referred to as the first support arm 23L) extends leftward from the transmission case 22. Specifically, the first support arm 23L is formed of a pipe material (a cylindrical member) having an axis in the machine width direction K1. The first support arm 23L is disposed between the transmission case 22 and an upper portion of the left side frame 18. The right end of the first support arm 23L is fixed to the left fixing plate 26, and the left end of the first support arm 23L is connected to the upper portion of the left side frame 18.

[0029] The other support arm 23 (referred to as second support arm 23R) extends rightward from the transmission case 22. Specifically, the second support arm 23R is formed of a pipe material (tubular member) having an axis in the machine width direction K1, and is disposed between the transmission case 22 and the upper part of the right side frame 18. The left end of the second support arm 23R is fixed to the right fixing plate 26, and the right end is connected to the upper part of the right side frame 18.

[0030] One (left) side frame 18 of the pair of side frames 18 is referred to as a first side frame 18L, and the other (right) side frame 18 is referred to as a second side frame 18R.

[0031] 1, each side frame 18 has a first frame member 34 and a second frame member 35. The first frame member 34 and the second frame member 35 are formed from plate material. The first frame member 34 and the second frame member 35 are arranged upright with their plate surfaces facing the machine width direction K1.

[0032] The first frame member 34 is provided to extend downward from the end of the support arm 23 opposite the transmission case 22. The lower part of the first frame member 34 is formed to have a longer front-to-rear width than the upper part. The first frame member 34 is disposed so that its lower rear end is located below the end of the support arm 23. In addition, the first frame member 34 is formed so that its lower front end is located below the front parts of the upper frame 27 and the lower frame 28.

[0033] The front portion of the second frame member 35 is connected to the lower rear end of the first frame member 34. In other words, the first frame member 34 protrudes upward from the front portion of the second frame member 35. The second frame member 35 is disposed so as to protrude further rearward from the lower rear end of the first frame member 34. The front portion of the second frame member 35 is superimposed on the outer surface of the first frame member 34 in the aircraft width direction K1 and connected to the first frame member 34.

[0034] 1, a notch 36 cut from bottom to top is provided on the lower end side of each side frame 18. The notch 36 allows stones, soil, and the like to escape from between the first side frame 18L and the second side frame 18R to the outside in the vehicle width direction K1 of the first side frame 18L and the second side frame 18R.

[0035] As shown in Fig. 4, the digging tool 20 is provided at the front of the machine frame 17. The digging tool 20 is also disposed between the first side frame 18L and the second side frame 18R.

[0036] As shown in Figure 4, digging tool 20 is formed from a plate material. More specifically, digging tool 20 is arranged with its plate surface facing up and down, and is attached to the front of machine frame 17 via mounting member 41. Machine frame 17 moves forward by being pulled by tractor 2 moving forward. As shown in Figure 2, as machine frame 17 moves forward, digging tool 20 moves forward over the top of ridge 15, digging up crop 16 (onions, etc.) grown in ridge 15 while cutting roots 16a of the crop 16.

[0037] As shown in Figure 2, the transport body 25 is disposed behind the digging tool 20. Specifically, the transport body 25 is disposed behind the digging tool 20 and between the first side frame 18L and the second side frame 18R. The transport body 25 is also disposed on an incline that slopes upward toward the rear. Therefore, the transport body 25 transports the crop 16 dug up by the digging tool 20 rearward and upward, and drops the crop 16 at its rear end 25a onto the upper surface 15a of the ridge 15 (field 14). The crop 16 that has fallen onto the upper surface 15a of the ridge 15 is picked up by a picker or the like operated separately.

[0038] 2, the power transmitted to the input shaft 24 is transmitted to the conveying body 25 via a power transmission device 48. The power transmission device 48 has a transmission shaft 49 housed in the second support arm 23R (see FIG. 4), a gear mechanism (bevel gear mechanism, not shown) that transmits power from the input shaft 24 to the transmission shaft 49, and a transmission mechanism (belt winding transmission mechanism) 52 that transmits power from the transmission shaft 49 to a drive shaft 51 of the conveying body 25.

[0039] As shown in FIG. 2, the conveying body 25 includes a drive shaft 51, a drive wheel 53, a driven wheel 54, and an endless rotating body (endless rotating body) 55.

[0040] 2, the drive shaft 51 is disposed at the rear of the machine frame 17. More specifically, the drive shaft 51 is disposed at a vertically midway point at the rear of the second frame members 35, spanning from the left second frame member 35 to the right second frame member 35. An end side of the drive shaft 51 is supported by the second frame members 35 via a bearing so as to be rotatable about an axis extending in the machine width direction K1.

[0041] The drive wheels 53 are disposed at the rear of the machine frame 17, and are provided on the left and right portions of the drive shaft 51 between the left second frame member 35 and the right second frame member 35. Each drive wheel 53 is fixed by a bolt or the like to a mounting plate fixed to the drive shaft 51. Therefore, the drive wheels 53 rotate integrally with the drive shaft 51.

[0042] As shown in FIG. 2, in this embodiment, the drive wheel 53 is configured as a sprocket having a plurality of teeth 53a arranged at intervals in the circumferential direction of the drive wheel 53 and around the entire circumference.

[0043] As shown in FIG. 2, the driven wheels 54 are located at the front and bottom of the machine frame 17 (second frame member 35). The driven wheels 54 are disposed behind the tool 20. The driven wheels 54 are provided on the inner side in the machine width direction K1 of the front part of the left second frame member 35 and on the inner side in the machine width direction K1 of the front part of the right second frame member 35. In other words, a pair (plurality) of driven wheels 54 are provided.

[0044] Each driven wheel 54 is supported by a support shaft 58 attached to the machine frame 17 so as to be rotatable about an axis extending in the machine width direction K1.

[0045] As shown in Figure 2, the endless runner 55 is wound around a drive wheel 53 and a driven wheel 54, and receives power from the drive wheel 53 to circulate in a circumferential direction (clockwise in Figure 2). The endless runner 55 has a number of conveying rods and a number of endless belts. The conveying rods are arranged in parallel at equal intervals in the direction of rotation of the endless runner 55, forming a loop. Each conveying rod is formed from a pipe material extending in the machine width direction K1, and has flattened portions formed by crushing the pipe material at both ends and the center of the pipe material in the longitudinal direction (machine width direction K1).

[0046] When power is transmitted from the drive wheel 53 to the endless rolling body 55, the drive wheel 53 rotates clockwise in FIG. 2, causing the endless rolling body 55 to also rotate clockwise, transporting the crops 16 rearward and upward.

[0047] As shown in Figure 4, a pair of side plates 86 are provided at the front of the machine frame 17, and are arranged on one side (left side) and the other side (right side) of the digging tool 20 in the machine width direction K1. More specifically, the pair of side plates 86 are a first side plate 86L arranged on the left side of the digging tool 20 and a second side plate 86R arranged on the right side of the digging tool 20. The first side plate 86L and the second side plate 86R can prevent the crops 16 dug up by the digging tool 20 from escaping outward in the machine width direction K1 and can also guide the crops 16 from the digging tool 20 to the conveyor 25.

[0048] As shown in Fig. 2, the side plate 86 is positioned above the digging tool 20. As shown in Fig. 4, the side plate 86 is positioned so that the plate surface faces the machine width direction K1, and is attached to the first frame member 34 of the side frame 18 via a plurality of mounting fixtures 87 so that the position can be adjusted in the machine width direction K1.

[0049] The multiple mounting fixtures 87 include a bolt member 62 that is inserted between the side plate 86 and the first frame member 34, a nut member 63 that is screwed onto the bolt member 62, and multiple collars (spacers) 89 that are interposed between the side plate 86 and the first frame member 34 and that are inserted into the bolt member 62. The number of collars 89 that are arranged between the side plate 86 and the first frame member 34 of the side plate 86 is changeable.

[0050] That is, as shown in FIG. 8(a), increasing the number of collars arranged between the side plate 86 and the first frame member 34 (for example, to four) increases the distance between the side plate 86 and the first frame member 34. Also, as shown in FIG. 8(b), decreasing the number of collars arranged between the side plate 86 and the first frame member 34 (for example, to one) decreases the distance between the side plate 86 and the first frame member 34. That is, in FIG. 8(a), the distance between the side plates 86 that guide the crops is narrower, whereas in FIG. 8(b), the distance between the side plates 86 that guide the crops is wider. Using multiple mounting fixtures 87 in this way allows the distance between the first side plate 86L and the second side plate 86R in the machine width direction K1 to be changed (the distance can be adjusted).

[0051] In this embodiment, the position of the side plate 86 in the machine width direction K1 is adjusted in stages using collars, but this is not limited to this. For example, the position of the side plate 86 in the machine width direction K1 may be adjusted continuously using a screw structure. Also, the position of the side plate 86 may be adjusted using an expandable structure in which multiple tubes are combined in a nested manner.

[0052] As shown in Figure 1, the excavator 4 is provided with a mounting frame 21 to which the three-point linkage 3 (lifting linkage) is connected. More specifically, the rear upper portion of the top link 11 of the three-point linkage 3 is connected to the excavator 4 via the mounting frame 21.

[0053] As shown in FIG. 1 , the mounting frame 21 includes an upper frame 27, a first connecting plate 29L, and a second connecting plate 29R. The lower portion of the upper frame 27 is disposed between a pair of fixing plates 26 that protrude forward from the left and right surfaces of the transmission case 22, and extends forward and upward. The first connecting plate 29L connects a portion slightly below the upper end of the upper frame 27 to the front portion of the left lower frame 28. The second connecting plate 29R connects a portion slightly below the upper end of the upper frame 27 to the front portion of the right lower frame 28. The first connecting plate 29L and the second connecting plate 29R are disposed in an inclined manner that slopes slightly rearward as they extend upward. The first connecting plate 29L is disposed on one side (left) of the machine casing 17 when viewed from the center of the machine casing 17 in the machine width direction K1, and the second connecting plate 29R is disposed on the other side (right) when viewed from the center of the machine casing 17 in the machine width direction K1.

[0054] As shown in Figure 5, the upper parts of the first connecting plate 29L and the second connecting plate 29R are connected to the upper part of the upper frame 27 by a tubular member 47, and the upper frame 27, the first connecting plate 29L, and the second connecting plate 29R are connected by a bolt 60A that passes through the upper frame 27, the first connecting plate 29L, the second connecting plate 29R, and the tubular member 47, and a nut 60B that is screwed onto the bolt 60A.

[0055] 1, the excavator 4 has an attitude adjustment mechanism 92 that adjusts the attitude of the excavator 4. The attitude adjustment mechanism 92 is provided on the mounting frame 21. More specifically, the attitude adjustment mechanism 92 is provided on the upper part of the mounting frame 21.

[0056] The attitude adjustment mechanism 92 changes the attitude of the excavator 4 during operation among a first attitude S1 (see FIG. 5), a second attitude S2 (see FIG. 6), and a third attitude (see FIG. 7).

[0057] The first position S1 shown in Figure 5 is a working position for digging up crop 16. In other words, the first position S1 can also be said to be a working position when performing normal digging work (during normal work). In the first position S1, digging tool 20 is in a horizontal position.

[0058] The second position S2 shown in Figure 6 is a position in which the digger 4 is lifted higher than in the first position S1. More specifically, the second position S2 is a position in which the digger 4 is tilted further downward in the front than in the first position S1, and the position of the digger 4 has shifted forward. The second position S2 is a working position in which, when turning the work implement 1 at the end of a ridge, the height of the digger 4 is raised, making it possible to avoid contact with the ground.

[0059] 7 is a position in which the digging tool 20 is tilted downward in front compared to the state in the first position S1. The third position is a working position that enables the digging tool 20 to penetrate deeper into the soil when the digging tool 20 would not penetrate deep enough in the soil if it were left in the first position S1. Note that the third position tilts the entire digging machine 4 downward in front, regardless of whether the first position S1 is horizontal or not.

[0060] Next, the structure of the attitude adjustment mechanism 92 will be described in detail with reference to FIGS.

[0061] As shown in FIGS. 5 to 7, the attitude adjustment mechanism 92 has a swinging member 93, an engaging member 94, a restricting member 65, and a biasing member 91a.

[0062] A pair of swinging members 93 are arranged on the upper part of the upper frame 27 so as to face each other in the machine width direction K1. Specifically, the upper part of the upper frame 27 has an upper piece 27a (left upper piece 27a) and an upper piece 27b (right upper piece 27b) that branch into two pieces spaced apart in the machine width direction K1. A swinging member 93 is provided on the inner side of the upper piece 27a in the machine width direction K1 and on the inner side of the upper piece 27b in the machine width direction K1. In other words, a pair of swinging members 93 are provided. The pair of swinging members 93 are arranged facing each other with a gap between them in the machine width direction K1.

[0063] The pair of swinging members 93 are supported on the upper part of the upper frame 27 via pivot shafts 96 so as to be rotatable about axes extending in the machine width direction K1. Specifically, as shown in Fig. 9 , the pair of swinging members 93 have pivoted portions 97 that are pivoted via the pivot shafts 96. The pivoted portions 97 of the pair of swinging members 93 are connected to each other by a tubular member 95. The pivot shaft 96 penetrates (is inserted through) the upper pieces 27a and 27b, the pair of swinging members 93, and the tubular member 95. As a result, the swinging members 93 are supported on the upper part of the upper frame 27 so as to be rotatable via the pivot shafts 96.

[0064] As shown in FIG. 10, each swinging member 93 has a top link connecting portion 101, an engagement hole 98, and a restricting member pivoting portion 100.

[0065] The top link connecting portion 101 extends from the pivotally supported portion 97 and protrudes from between the first connecting plate 29L and the second connecting plate 29R. As shown in FIG. 9, a connecting portion 11A on the rear end side of the top link 11 is disposed between the pair of top link connecting portions 101. The connecting portion 11A is connected to the top link connecting portion 101 via a connecting pin 102 and extends in the width direction K1. The shafts are connected to each other so as to be rotatable about the same axis.

[0066] 5 to 7, the engagement hole 98 is formed at a position where the pivot shaft 96 is sandwiched between the engagement hole 98 and the top link connecting portion 101. The engagement hole 98 is formed as an elongated hole in the shape of an arc with the axis of the pivot shaft 96 as its center.

[0067] The restriction member pivotal support portion 100 is a portion that pivotally supports the restriction member 65. The restriction member pivotal support portion 100 protrudes upward from between the first connecting plate 29L and the second connecting plate 29R.

[0068] The engaging member 94 is provided on the mounting frame 21. More specifically, as shown in FIGS. 5 to 7 and 10, the engaging member 94 includes a collar (cylindrical body) 99 that is inserted through an engaging hole 98, and an attachment member 103 that attaches the collar 99 to the first connecting plate 29L and the second connecting plate 29R. The collar 99 is disposed so as to span the engaging holes 98 of the pair of swing members 93. The attachment member is made up of the first connecting plate 29L, the second connecting plate 29R, and a bolt member 103A that is inserted through the collar 99, and a nut member 103B that is screwed onto the bolt member 103A. The collar 99 is fitted onto the outside of the bolt member 103A so as to be rotatable relative to the bolt member 103A around its axis.

[0069] When the swinging member 93 swings around the axis of the pivot shaft 96, the engaging member 94 is capable of moving relatively from one end 98a to the other end 98b of the engaging hole 98. In this embodiment, the one end 98a of the engaging hole 98 is the upper end, and the other end 98b is the lower end.

[0070] As shown in FIG. 5, when the excavator 4 is in the first position S1, the engagement member 94 is located at the midpoint of the engagement hole 98 in the longitudinal direction (in this embodiment, approximately the central portion 98c of the engagement hole 98 in the longitudinal direction). Furthermore, when the excavator 4 is in the second position S2, as shown in FIG. 6, the engagement member 94 is located at the other end 98b of the engagement hole 98. When changing the position of the excavator 4 from the first position S1 to the second position S2, the lifting link mechanism 3 is operated to lift. This causes the swing member 93 to swing around the pivot shaft 96, and the engagement member 94 moves from the central portion 98c of the engagement hole 98 to the other end 98b (lower end). Furthermore, when changing the position of the excavator 4 from the second position S2 to the first position S1, the lifting link mechanism 3 is operated to lower. Then, the swinging member 93 swings around the pivot shaft 96, and the engaging member 94 moves from the other end 98b (lower end) of the engaging hole 98 to the central portion 98c.

[0071] Furthermore, when the excavator 4 is in the third position, as shown in Figure 7, the engagement member 94 is located at one end 98a (upper end) of the engagement hole 98. When changing the position of the excavator 4 from the first position S1 to the third position, the lifting link mechanism 3 is lowered. This causes the swing member 93 to swing around the pivot shaft 96, and the engagement member 94 to move from the center 98c of the engagement hole 98 to the one end 98a (upper end). When changing the position of the excavator 4 from the third position to the first position S1, the lifting link mechanism 3 is raised. This causes the swing member 93 to swing around the pivot shaft 96, and the engagement member 94 to move from the one end 98a (upper end) of the engagement hole 98 to the center 98c.

[0072] The regulating member 65 regulates the excavator 4 from changing its position from the first position S1 to the third position. Specifically, as shown in Fig. 5, the regulating member 65 abuts against the engaging member 94 to regulate the swinging of the swinging member 93 and regulates the engagement member 94 from moving from the central portion 98c of the engaging hole 98 to the one end 98a, thereby regulating the excavator 4 from changing its position from the first position S1 to the third position.

[0073] Furthermore, the regulating member 65 regulates the excavator 4 from changing its position from the second position S2 to the first position S1. Specifically, the regulating member 65 abuts against the engaging member 94 to regulate the swinging of the swinging member 93 and regulates the engaging member 94 from moving from the other end 98b of the engaging hole 98 to the central part 98c, thereby regulating the excavator 4 from changing its position from the second position S2 to the first position S1.

[0074] As shown in FIG. 10, the restricting member 65 is disposed at a position between the pair of swinging members 93.

[0075] 5 to 7 and 10, the regulating member 65 has a supported portion 65a that is pivotally supported by the regulating member pivotal support portions 100 between the regulating member pivotal support portions 100 of the pair of swinging members 93. The supported portion 65a is located above the first connecting plate 29L and the second connecting plate 29R and is pivotally supported by the regulating member pivotal support portions 100. The regulating member 65 is pivotally supported on the regulating member pivot support portion 100 via a pivot 104. More specifically, a cylindrical boss 105 that penetrates the supported portion 65a in the machine width direction is fixed to the supported portion 65a. The cylindrical boss 105 is disposed between the pair of swinging members 93. The pivot 104 is formed by a pin, and penetrates the first connecting plate 29L, the second connecting plate 29R, the cylindrical boss 105, and a boss 106 fixed to the second connecting plate 29R. As a result, the regulating member 65 is supported on the swinging member 93 via the pivot 104 so as to be rotatable about an axis extending in the machine width direction K1.

[0076] As shown in FIGS. 5 to 7, the restricting member 65 has an extending portion 65b extending downward from the supported portion 65a. The extending portion 65b has a restricting portion 65c at its lower portion that abuts against the engaging member 94 (collar 99). The surface of the restricting portion 65c that abuts against the engaging member 94 has an arcuate surface 65d that matches the outer peripheral surface of the engaging member 94. The restricting portion 65c restricts the swinging of the swinging member 93 by bracing between the pivot 104 and the engaging member 94. More specifically, the restricting member 65 restricts the swinging of the swinging member 93 around the pivot 96, that is, the swinging of the engaging member 94 in the direction in which the engaging member 94 moves from the center portion 98c of the engaging hole 98 to the other end 98b. In other words, the restricting member 65 has a restricting portion 65c that abuts against the engaging member 94 and restricts the engaging member 94 from moving from the center portion 98c (midway portion) of the engaging hole 98 to the other end 98b.

[0077] As shown in Fig. 5, a guide portion 65e is formed on the surface of the extension portion 65b facing the pivot shaft 96. In Fig. 5, the guide portion 65e is formed as an inclined surface that transitions rearward as it extends downward. The guide portion 65e is a portion that comes into sliding contact with the engagement member 94 and guides the restriction portion 65c to the engagement member 94 when the engagement member 94 moves from the center portion 98c of the engagement hole 98 to the other end 98b.

[0078] 5, the restricting member 65 has a stopper portion 65f extending forward from the supported portion 65a. When the restricting member 65 is rotated in a direction in which the restricting portion 65c moves away from the engaging member 94 (the direction of arrow D1 in FIG. 5), the stopper portion 65f comes into contact with the cylindrical member 95, thereby restricting the rotation of the restricting member 65 in the direction of arrow D1.

[0079] As shown in Fig. 5, the regulating member 65 has an operating portion 65g extending upward from the supported portion 65a. An insertion hole 65h is formed on the extending end side of the operating portion 65g. As shown in Fig. 5, one end of a cord (rope) 107 inserted through the insertion hole 65h is connected to the extending end side of the operating portion 65g. As shown in Fig. 1, the cord 107 is routed forward from the attitude adjustment mechanism 92 (operating portion 65g) to a position that reaches the driver's seat 30. Therefore, the cord 107 can be pulled by an operator from the driver's seat 30, and the operator can operate the regulating member 65 from the driver's seat 30 by pulling the cord 107.

[0080] By pulling the restricting member 65, the restricting member 65 can be rotated in a direction in which the restricting portion 65c moves away from the engaging member 94. Then, by moving the restricting member 65 (restricting portion 65c) away from the engaging member 94, the swinging member 93 is allowed to swing in the direction of arrow D4, and the engaging member 94 is allowed to move from the other end 98b of the engaging hole 98 to the center portion 98c. In other words, the restriction by the restricting member 65 can be released.

[0081] As shown in FIG. 5, a spring hook member 108 is attached to the regulating member 65. The spring hook member 108 is attached to the base of the operating unit 65g. More specifically, as shown in FIG. 10, the spring hook member 108 is made of a bolt member and has a threaded portion 108a (a portion with an external thread on the outer circumferential surface) on one end. The threaded portion 108a is screwed into a threaded hole 109 (a hole with an internal thread on the inner circumferential surface) formed in the base of the operating unit 65g. A lock nut 108b is screwed into the threaded portion 108a to prevent loosening of the threaded portion 108a. The spring hook member 108 protrudes from the regulating member 65 in the machine width direction K1 (rightward).

[0082] As shown in Figs. 5 to 7 and 10, the biasing member 91a is formed of a tension coil spring. The biasing member 91a is disposed on the right side of the mounting frame 21. One end of the biasing member 91a is hooked to a spring hook member 108. The other end of the biasing member 91a is hooked to a spring hook portion 132 provided on the mounting frame 21. In more detail, as shown in Fig. 10, the mounting frame 21 has an upper plate 91C provided between the upper ends of the first connecting plate 29L and the second connecting plate 29R, and the spring hook portion 132 is It is configured by forming a hole in a protruding portion.

[0083] The biasing force of the biasing member 91a acts in a direction to bring the regulating member 65 into contact with the engaging member 94, at least within the range in which the engaging member 94 moves between the other end 98b and the central portion 98c of the engaging hole 98. In other words, when the guide portion 65e is in contact with the engaging member 94, the biasing force of the biasing member 91a acts in a direction to press the guide portion 65e against the engaging member 94 within the range in which the engaging member 94 moves from the central portion 98c of the engaging hole 98 to just before reaching the other end 98b. Furthermore, as shown in FIG. 7, when the regulating portion 65c is in contact with the engaging member 94, the biasing force of the biasing member 91a acts in a direction to press the regulating portion 65c against the engaging member 94. Therefore, the regulation by the regulating member 65 is automatically performed by the operation of changing the position of the excavator 4 from the first position S1 to the second position S2. More specifically, the guide portion 65e abuts against the engaging member 94 when the engaging member 94 is positioned at a center portion 98c of the engaging hole 98, and when the engaging member 94 moves from the center portion 98c of the engaging hole 98 toward the other end 98b, the restricting member 65 swings following the movement of the engaging member 94. As a result, the engaging member 94 slides on the guide portion 65e, and the abutting point between the guide portion 65e and the engaging member 94 moves toward the restricting portion 65c. Then, when the engaging member 94 reaches the other end 98b of the engaging hole 98, the restricting portion 65c abuts against the engaging member 94 due to the biasing force of the biasing member 91a.

[0084] As described above, the restriction by the restricting member 65 is automatically performed by the operation of changing the position from the first position S1 to the second position S2.

[0085] Incidentally, there may be a step at the longitudinal end of ridge 15. When such a step exists, if tractor 2 enters ridge 15 and steps on the step, digging tool 20 will not penetrate deep enough into the soil, potentially damaging crops 16. In such a case, digger 4 is placed in the third position before entering ridge 15. In the third position, digging tool 20 is tilted downward in front compared to first position S1, preventing digging tool 20 from penetrating deeper into the soil and damaging crops 16. Once digger 4 has entered ridge 15 and traveled a predetermined distance (e.g., 2 to 3 m), digger 4 is changed from the third position to first position S1, and then most of the crops 16 in ridge 15 are dug up in first position S1. If there is a step on the end side of the ridge 15 in the longitudinal direction, the excavator 4 is also set to the third position on the outlet side of the ridge 15.

[0086] In the excavator 4 configured as described above, when in the first position S1, the regulating member 65 restricts the position change from the first position S1 to the third position, so the excavator 4 does not move between the first position S1 and the third position, making the digging operation unstable, and the digging operation can be performed stably.

[0087] Furthermore, the regulating member 65 automatically regulates the change in position from the first position S1 to the third position by changing the position from the third position to the first position S1, so there is no need for the operator to get off the tractor 2 to regulate with the regulating member 65, which is very convenient.

[0088] With conventional farm machinery, when the digger is lifted, for example, when turning on a headland, the digger assumes a lifting position with the front of the digger lowered. This causes the crops remaining in the digger to fall forward from the digging tool. The fallen crops are trampled by the tractor and are lost. In addition, the crops that escape trampling must be collected separately, significantly reducing work efficiency.

[0089] Therefore, in the digger 4 of this embodiment, a fall prevention device 110 is provided to prevent the crops 16 remaining in the digger 4 from falling forward from the digging tool 20 when the digger 4 is lifted from the first position S1 to the second position S2.

[0090] More specifically, when the three-point linkage mechanism 3 is swung upward at the headland, the weight of the digger 4 acting on the engaging member 94 causes the swinging member 93 to swing around the pivot shaft 96 so that the engaging member 94 moves toward the other end 98b of the engaging hole 98. This causes the rear side of the digger 4 to be lifted, as shown in Figure 3. As the rear side of the digger 4 is lifted, the digging tool 20 tilts upward and moves forward relatively.

[0091] When the engaging member 94 moves to the other end 98b of the engaging hole 98 as shown in FIG. 3, the excavator 4 is raised from the state shown in FIG. 2 (the state of the first position S1) to the lifted position S2 shown in FIG. 3. In the lifted position S2 shown in FIG. 3, the excavator 4 is lifted from the front side. As a result, the rear side of the digging tool 20 is lifted higher than the digging tool 4, and the digging tool 20 is tilted further forward. This makes it easier for the crops 16 remaining in the digger 4 to fall.

[0092] 11, the digger 4 of this embodiment is equipped with a fall prevention device 110 provided with a fall prevention member 111 that is positioned on the digging tool 20 to prevent the crops 16 remaining in the digging machine 4 from falling forward from the digging tool 20 when the digging machine 4 is towed by the work machine 1 (traveling vehicle) and moves forward together with the work machine 1, and the digging machine 4 is lifted from the working position (first position S1) in which the crops 16 are dug up by the digging tool 20 to the lifting position (second position S2). In other words, the fall prevention device 110 of the present invention is arranged near the digging tool 20 (in the case of this embodiment, in a position adjacent to the front of the digging tool 20) when the crops 16 remaining in the digging machine 4 attempt to fall through the digging tool 20, thereby stopping the movement of the falling crops 16.

[0093] It should be noted that fall prevention device 110 must be configured so as not to impede the movement of crop 16 when crop 16 is being dug up. For this reason, fall prevention device 110 is equipped not only with fall prevention member 111 that is provided at a position where crop 16 will fall to stop the fall of crop 16, but also with position change device 112 that changes the position of the fall prevention member between a fall prevention position and a retracted position.

[0094] Next, the fall prevention member 111 and the position change device 112 will be described.

[0095] 11, the fall prevention member 111 is a flat plate-shaped member that extends in the vertical direction and the machine width direction K1. The fall prevention member 111 is formed so that its dimension in the machine width direction K1 is longer than its dimension in the vertical direction. The dimension of the fall prevention member 111 in the machine width direction K1 is slightly shorter than the dimension in the machine width direction K1 from the left side plate 86 to the right side plate 86, which can reliably prevent the crops 16 from falling.

[0096] As shown in FIG. 12 , the fall prevention member 111 includes a flat fall prevention plate 111a and a support 111b that supports the fall prevention plate 111a. The fall prevention plate 111a is made of a flexible elastic material so as not to damage the crops 16. Various types of rubber or elastomers can be used for such elastic material. The fall prevention plate 111a can be made of multiple elastic members with different thicknesses and materials. For example, a fall prevention plate 111a that combines a flexible elastic member with a slightly harder elastic member not only prevents damage to the crops 16 but also reliably stops the crops 16 from falling. In other words, configuring the fall prevention plate 111a by varying the thickness and material type of the elastic members allows the fall prevention plate 111a to be appropriately selected according to the type of crop 16 and the size of the digger 4, thereby improving the convenience of the digger 4.

[0097] The support 111b includes a first support 115 having a substantially L-shaped cross section when viewed from the left or right, and a second support 116 attached to the rear of the first support 115 at the fall prevention position. The first support 115 and the second support 116 are integrally connected by a plurality of bolts and nuts provided across the width direction K1, with the fall prevention plate 111a sandwiched between them from the front and rear. In other words, the support 111b is able to support the fall prevention plate 111a by being connected between the first support 115 and the second support 116 with the fall prevention plate 111a sandwiched between them.

[0098] The lower end of the tip member 113b of the support 113 is fixed to the left and right portions of the first support 115 by means of welding, screwing, or the like. In other words, when the tip member 113b of the support 113 is swung back and forth relative to the base end member 113a, the second support 116 (support 111b) also swung back and forth.

[0099] A width dimension adjustment mechanism 117 is provided at the left or right end of the fall prevention member 111, which can expand or contract the dimension of the fall prevention member 111 in the machine width direction K1. The width dimension adjustment mechanism 117 has a pair of extension plates 117a provided at the left and right ends of the fall prevention plate 111a, and extension plate engaging members 117b that can engage the pair of extension plates 117a with the left and right ends of the fall prevention plate 111a so that the engagement position in the machine width direction K1 can be changed. The extension plates 117a are members that have a substantially L-shaped cross section when viewed from the left or right, similar to the fall prevention member 111. The extension plate 117a includes a first extension plate support portion 117c having a substantially L-shaped cross section similar to the above-described first support tool 115, a second extension plate support portion 117d disposed behind the first extension plate support portion 117c, and a first extension plate member 117e sandwiched between the first extension plate support portion 117c and the second extension plate support portion 117d. In other words, the extension plate 117a is formed using the same material as the above-described fall prevention member 111 so as to have the same cross-sectional structure. Therefore, the extension plate 117a can be placed above or below the fall prevention member 111, and can slide in the machine width direction K1 while placed above the fall prevention member 111.

[0100] The extension plate engaging device 117b includes a first engaging hole 117f formed in either the fall prevention member 111 or the extension plate 117a, a second engaging hole 117g formed in the other of the fall prevention member 111 or the extension plate 117a, and a communicating bolt 117h inserted through the first engaging hole 117f and the second engaging hole 117g so that they communicate with each other. At least one of the first engaging hole 117f and the second engaging hole 117g is formed as an elongated hole that is long along the aircraft width direction K1, so that the engaging position by the communicating bolt 117h can be changed in the aircraft width direction K1.

[0101] 12(a), consider a case where the first engagement hole 117f is formed as an elongated hole extending along the width direction K1 of the machine, and the second engagement hole 117g is formed as a round hole. In this case, if the communicating bolt 117h is adjusted so that it passes through the end of the first engagement hole 117f on the inside in the width direction K1 of the machine and communicates with the second engagement hole 117g, the dimension from the left end of the left extension plate 117a to the right end of the right extension plate 117a can be shortened.

[0102] On the other hand, as shown in the enlarged view of FIG. 12(b), by adjusting the connecting bolt 117h so that it passes through the outer end of the first engagement hole 117f in the machine width direction K1 and communicates with the second engagement hole 117g, the dimension from the left end of the left extension plate 117a to the right end of the right extension plate 117a can be increased. Because the dimension of the fall prevention member 111 from the left end of the left extension plate 117a to the right end of the right extension plate 117a can be adjusted in this way, even if the spacing between the left and right side plates 86 is changed using multiple mounting fixtures 87, the dimension of the fall prevention member 111 can be adjusted according to the changed spacing. As a result, it is possible to prevent problems such as the crops 16 falling out of the gap between the fall prevention member 111 and the side plates 86 becoming too wide or the crops 16 getting caught in the gap, causing damage to the digger 4.

[0103] The position changing device 112 changes the position of the fall prevention member 111 between a fall prevention position and a retracted position.

[0104] The "fall prevention position" is the position when the digger is lifted, and is a position that can prevent the crop 16 from falling forward from the digging tool 20 when the digger 4 is lifted to the second position S2 (lifted position).

[0105] The "retracted position" is a position where the robot is retracted from the fall prevention position and allows the digging up of crops.

[0106] That is, position changing device 112 changes the position of fall prevention member 111 to prevent or allow plant 16 to move.

[0107] Specifically, the position change device 112 has a support 113 to which a fall prevention member 111 is attached and which is supported on the excavator 4 so as to be able to swing freely around an axis extending in the width direction of the excavator 4, and a linkage member 114 which links the support 113 to a change in the attitude of the excavator 4 or the swing of the lifting link mechanism so as to swing the support 113 and change the position of the fall prevention member 111 between a fall prevention position and a retracted position.

[0108] The support body 113 has a base end member 113a connected to the connecting body 32 of the excavator 4, a tip end member 113b connected to the fall prevention member 111, a swing shaft 113c that pivots the tip end member 113b so that it can swing freely relative to the base end member 113a, and a regulating device 113d that allows the tip end member 113b to swing rearward beyond a predetermined position and prevents the tip end member 113b from swinging forward beyond the predetermined position.

[0109] Furthermore, the excavator 4 of this embodiment has a biasing member 113e that biases the tip member 113b relative to the base end member 113a in a direction in which the tip member 113b swings forward relative to the base end member 113a.

[0110] As shown in FIG. 11, the base end member 113a connects the pair of left and right lower frames 28 together. The base end member 113a is provided on the left and right sides of the connecting body 32. Taking the base end member 113a provided on the left side of the connecting body 32 as an example, the base end member 113a includes a cylindrical portion 136 formed in a cylindrical shape that can be fitted onto the connecting body 32, and a protruding portion 137 that protrudes forward from the cylindrical portion 136. A swing shaft 113c is provided at the front end of the protruding portion 137 that protrudes forward.

[0111] The base end member 113a is provided with a fastening bolt (not shown), and the base end member 113a can be fixed to any position on the connecting body 32 extending in the machine width direction K1. The base end member 113a provided on the right side of the connecting body 32 has a structure that is bilaterally symmetrical to the right base end member 113a, and has a similar structure to the right base end member 113a except for the bilateral symmetry.

[0112] The tip member 113b includes a first member 118 connected to the fall prevention member 111, a second member 119 pivotally supported on the swing shaft 113c, and a connecting portion 120 that connects the first member 118 to the second member 119 so that the distance from the first member 118 to the second member 119 can be freely changed.

[0113] Specifically, the first member 118 is a long plate-like member disposed so as to extend in the vertical direction on the upper surface of the support 111b of the fall prevention member 111. As described above, the first member 118 is fixed to the left and right parts of the first support 115 of the support 111b by means of welding, screwing, or the like. The first member 118 has a plurality of (ten in this embodiment) first positioning holes 121 formed at equal intervals in the vertical direction.

[0114] The second member 119 includes a main body 119a formed in a long rod shape arranged along the aircraft width direction K1, upper protrusions 119b formed to protrude upward from the left and right parts of the main body 119a, and lower protrusions 119c formed to protrude downward from the left and right ends of the main body 119a. In this embodiment, the lower protrusions 119c are positioned outward in the aircraft width direction K1 than the upper protrusions 119b, but the lower protrusions 119c may also be positioned inward in the aircraft width direction K1 than the upper protrusions 119b.

[0115] A swing shaft 113c is provided at the upper end of the upper protrusion 119b of the second member 119 so that its axis is oriented in the machine width direction K1. Also, a pivot shaft 122 that pivotally supports the connection part 120 relative to the lower protrusion 119c so that it can swing freely is provided at the lower protrusion 119c so that its axis is oriented in the machine width direction K1.

[0116] Furthermore, first biasing member support pieces 125 are formed on the left and right parts of the main body 119a, passing behind the lower protrusion 119c and the connecting portion 120, and extending from outside the connecting portion 120 in the machine width direction K1 to the front of the connecting portion 120. The tip (front end) of the first biasing member support piece 125 supports the upper end of the biasing member 113e.

[0117] The connecting portion 120 is a long plate-shaped member that connects the first member 118 and the second member 119. A pivot shaft 122 is provided at the upper end of the connecting portion 120, and the pivot shaft 122 allows the connecting portion 120 to swing freely around an axis facing the machine width direction K1 relative to the lower protrusion 119c. Two second positioning holes 123 are formed at the upper end of the connecting portion 120, lined up in the vertical direction. The vertical spacing between the second positioning holes 123 is set equal to that of the first positioning hole 121 described above, and the connecting portion 120 can be fixed to the first member 118 by inserting a positioning bolt 124 through the first positioning hole 121 and the second positioning hole 123 in communication with each other.

[0118] In other words, by arbitrarily selecting the first positioning hole 121 through which the positioning bolt 124 is inserted from among the multiple provided first positioning holes, the length from the base end to the tip of the support body 113 can be freely changed by the connecting part 120. For example, if the positioning bolt 124 is inserted into the first positioning hole 121 located at the top of the multiple first positioning holes 121, the length from the base end to the tip of the support body 113 will be longer. On the other hand, if the positioning bolt 124 is inserted into the first positioning hole 121 located at the bottom, the length from the base end to the tip of the support body 113 will be shorter. In this way, the length from the base end to the tip of the support body 113 can be freely changed by the connecting part 120.

[0119] A second biasing member support piece 126 that supports the lower end of the biasing member 113e is provided at the vertical midpoint of the connecting portion 120 (at a position slightly below the middle position) so as to protrude forward.

[0120] The swing shaft 113c pivotally supports the tip member 113b relative to the base member 113a so that the tip member 113b can swing freely. Specifically, as described above, the tip member 113b is provided with the second member 119, and the second member 119 is provided with the upper protrusion 119b. The swing shaft 113c communicates the upper end of the upper protrusion 119b with the front end of the plate-shaped portion of the base member 113a that protrudes forward along the machine width direction K1.

[0121] The restrictor 113d is a member that allows the tip member 113b to swing rearward from a predetermined position and prevents the tip member 113b from swinging forward from the predetermined position. Specifically, in this embodiment, the above-described first biasing member support piece 125 also functions as the restrictor 113d. In other words, when the tip member 113b swings forward from the predetermined position, the connection portion 120 above the pivot shaft 122 swings rearward. However, the first biasing member support piece 125 is disposed behind the lower protrusion piece 119c and the connection portion 120. Therefore, the upper end of the connection portion 120 swinging rearward comes into contact with the first biasing member support piece 125, thereby restricting the forward swing of the connection portion 120. More precisely, the forward swing of the connection portion 120 below the pivot shaft 122 is restricted. When the connecting part 120 swings rearward, the connecting part 120 above the pivot shaft 122 swings forward, so the tip member 113b is allowed to swing rearward from a predetermined position.

[0122] The upper end of the urging member 113e is supported by the tip (front end) of the first urging member support piece 125, and the lower end is supported by the second urging member support piece 126. The urging member 113e exerts a urging force between the first urging member support piece 125 and the second urging member support piece 126, thereby urging the tip member 113b, which is located behind a predetermined position, forward.

[0123] The interlocking member 114 is a member that swings the support body 113 to change the position of the fall prevention member 111 between the fall prevention position and the retracted position. The change in the position of the fall prevention member 111 by the interlocking member 114 is performed in conjunction with a change in the attitude of the excavator 4 or the swing of the lifting link mechanism 3.

[0124] The position of fall prevention member 111 shown in Figure 3 is the "fall prevention position." The "fall prevention position" is a position where the lower edge of fall prevention member 111 is above or at the upper front of digging tool 20. In other words, in the present invention, a position where the lower edge of fall prevention member 111 is above or at the upper front of digging tool 20 is referred to as "fall prevention member 111 being located at digging tool 20."

[0125] 1, the "retracted position" is a position spaced forward and above the "fall prevention position." In this embodiment, the "retracted position" is a position where the fall prevention member 111 is located slightly below the lower link 12. However, the "retracted position" may be located even lower as long as the fall prevention member 111 is located far enough away so as not to interfere with the movement of the crop 16.

[0126] When fall prevention member 111 is in the "fall prevention position", fall prevention member 111 is located on the path of fall of crop 16, thereby preventing crop 16 from falling. On the other hand, when fall prevention member 111 is in the "retracted position", fall prevention member 111 is located at a height that does not interfere with the movement of crop 16, and therefore does not interfere with the work of transporting dug-up crop 16 backward.

[0127] Specifically, as shown in Figures 11 and 13, the interlocking member 114 has an interlocking shaft 127 whose upper end is connected to the top link connection portion 101, a first interlocking member 128 connected to the lower end of the interlocking shaft 127, a first fixed member 129 fixed to the middle portion of the connecting body 32 in the machine width direction K1 (a position slightly to the left of the middle) and to which the rear end of the first interlocking member 128 is connected so as to be rotatable around an axis extending in the machine width direction K1, a second fixed member 130 fixed to the main body 119a of the second member 119, and a second interlocking member 131 connected to both the second fixed member 130 and the first interlocking member 128.

[0128] The interlocking shaft 127 is a long rod-shaped member extending in the vertical direction, and is connected to the top link connecting part 101 via a connecting pin 102 so as to be rotatable about an axis extending in the machine width direction K1. The lower end of the interlocking shaft 127 is connected to a midpoint in the front-rear direction of the first interlocking member 128 so as to be rotatable about an axis extending in the machine width direction K1.

[0129] The first fixing member 129 is a cylindrical member that is inserted into the connecting body 32 midway in the machine width direction K1, and is fixed to the connecting body 32 so that the fixing position can be freely changed in the machine width direction K1. The fixing position of the first fixing member 129 in the connecting body 32 is not at the center position in the machine width direction K1, but at a position offset from the center position to either end. By attaching the first fixing member 129 to such an offset position, it is possible to avoid physical interference between the first fixing member 129 and the input shaft 24.

[0130] Furthermore, a plate-shaped portion that protrudes upward is formed on the top of the first fixing member 129, and the rear end of the first interlocking member 128 is connected to this protruding portion so as to be rotatable around an axis extending in the machine width direction K1. Furthermore, the second fixing member 130 is fixed to the main body 119a of the second member 119 by means of welding or the like.

[0131] The second interlocking member 131 is pivotally supported on both the upper part of the second fixed member 130 and the front end of the first interlocking member 128, and is connected to both of them so as to be rotatable around an axis extending in the machine width direction K1.

[0132] In other words, the first interlocking member 128 and the second interlocking member 131 of the interlocking member 114 constitute a parallel link mechanism that converts the parallel movement of the interlocking shaft 127 along the vertical direction into a rotational movement that swings the fall prevention member 111 in the forward and backward directions.

[0133] 13(a), when the interlocking shaft 127 is moved downward, the parallel link mechanism formed by the first interlocking member 128 and the second interlocking member 131 swings forward, and the fall prevention member 111 swings backward from an upper front to a lower rear. As a result, the fall prevention member 111 changes from the retracted position to the fall prevention position.

[0134] 13(b), when the interlocking shaft 127 is moved upward, the parallel link mechanism formed by the first interlocking member 128 and the second interlocking member 131 swings backward, and the fall prevention member 111 swings forward from a rear-lower, lower position to a front-upper position. As a result, the fall prevention member 111 changes from the fall prevention position to the retracted position.

[0135] As shown in Figure 2, when work machine 1 is in first position S1, crops 16 dug up by digging tool 20 are being carried by carrier 25 behind and above digging tool 20. When turning work machine 1 on a headland or the like, the position of digger 4 is changed from first position S1 shown in Figure 2 to second position S2 shown in Figure 3 using position adjustment mechanism 92 to avoid damage to digging tool 20. Then, as shown in Figure 6, the weight of digger 4 acting on engagement member 94 causes swing member 93 to swing about pivot shaft 96 so that engagement member 94 moves from center portion 98c of engagement hole 98 to the other end 98b.

[0136] Furthermore, when the oscillating member 93 oscillates around the pivot axis 96, the position of the top link connection part 101 also moves (oscillates) around the pivot axis 96 by the distance (angle) indicated by "D" in Figure 6, and the interlocking shaft 127 connected to the top link connection part 101 via the connecting pin 102 moves downward.

[0137] 13(a), in the parallel link mechanism, one end (the rear lower end in FIG. 11) of the second interlocking member 131 connected to the second fixed member 130 swings forward relative to the other end (the front upper end in FIG. 11) of the second interlocking member 131. Also, one end (the rear upper end in FIG. 11) of the first interlocking member 128 connected to the first fixed member 129 swings forward relative to the other end (the front lower end in FIG. 11). Then, the fall prevention member 111 swings backward from the front upper side toward the rear lower side.

[0138] As a result, the fall prevention member 111 changes from the retracted position shown in Figure 14(b) to the fall prevention position shown in Figure 14(a), preventing the crops 16 remaining in the digger 4 from falling in front of the digging tool 20.

[0139] On the other hand, when the work implement 1 has finished turning and is ready to resume digging up the crop 16, the position of the digging tool 20 is lowered below the upper surface 15a of the ridge 15 (field 14). In other words, the state of the attitude adjustment mechanism 92 is returned from the second attitude S2 shown in Figure 3 to the first attitude S1 shown in Figure 2. Then, due to the weight of the digger 4 acting on the engagement member 94, the swinging member 93 swings around the pivot shaft 96 so that the engagement member 94 moves to the center 98c of the engagement hole 98, as shown in Figure 5.

[0140] When the swinging member 93 swings around the pivot shaft 96, the position of the top link connecting part 101 also swings around the pivot shaft 96 by an angle indicated by D in the figure, and the top link The interlocking shaft 127 connected to the linking portion 101 moves upward.

[0141] 13(b), in the parallel link mechanism, one end (the rear lower end in FIG. 11) of the second interlocking member 131 connected to the second fixed member 130 swings backward relative to the other end (the front upper end in FIG. 11) of the second interlocking member 131. Also, one end (the rear upper end in FIG. 11) of the first interlocking member 128 connected to the first fixed member 129 swings backward relative to the other end (the front lower end in FIG. 11). Then, the fall prevention member 111 swings forward from the rear lower side toward the front upper side.

[0142] As a result, it is possible to change the fall prevention member 111 from the fall prevention position shown in Fig. 13(a) to the retracted position shown in Fig. 13(b). In addition, the fall prevention device 110 does not interfere with the work of digging up the crops 16.

[0143] Even if it becomes possible to move the position of the fall prevention member 111 to the retracted position, if the fall prevention member 111 is in contact with the ground surface, the surface soil etc. may provide resistance, preventing the position of the fall prevention member 111 from returning to the retracted position, and the position of the fall prevention member 111 may remain in the fall prevention position.

[0144] However, the above-described fall prevention device 110 is provided with a biasing member 113e, and the support body 113 allows the fall prevention member 111 to swing backward. Therefore, even if the traveling vehicle 2 is moved forward and a force acts on the fall prevention member 111 from the front, the fall prevention member 111 swings backward to absorb the force, and the fall prevention device 110 is not damaged.

[0145] Eventually, when the height of the ground surface decreases and the fall prevention member 111 is no longer in contact with the ground surface, the resistance from the ground surface soil and the like disappears, and the fall prevention member 111 swings forward due to the restoring force of the biasing member 113e. The position of the fall prevention member 111 can be reliably returned from the fall prevention position to the retracted position.

[0146] In the excavator 4, the position changing device 112 may include a support 113 to which the fall prevention member 111 is attached and which is supported on the excavator 4 so as to be able to swing freely around an axis extending in the width direction K1 of the excavator 4, and an actuator 135 that swings the support 113 to change the position of the fall prevention member 111 between a fall prevention position and a retracted position. good.

[0147] Specifically, the above-mentioned actuator 135 is disposed between the base end member 113a and the tip end member 113b, as indicated by the dotted line in Fig. 6. In other words, the rear end of the actuator 135 is provided on the base end member 113a of the support body 113, more precisely, on the right side of the connecting body 32 in the machine width direction K1. Also, the front end of the actuator 135 is provided on the tip end member 113b of the support body 113, more precisely, on the right side of the main body 119a of the second member 119 in the machine width direction K1. The actuator 135 can be freely extended or retracted by an operator using electricity, hydraulics, or the like.

[0148] By extending the actuator 135, the distance from the connecting body 32 to the main body 119a becomes longer, making it possible to swing the tip member 113b forward relative to the base member 113a, and changing the position of the fall prevention member 111 from the fall prevention position to the retracted position.

[0149] Furthermore, by retracting the actuator 135, the distance from the connecting body 32 to the main body 119a becomes shorter, making it possible to swing the tip member 113b backward relative to the base member 113a, and changing the position of the fall prevention member 111 from the retracted position to the fall prevention position.

[0150] The extension and retraction operation of actuator 135 may be performed manually by an operator, or may be performed automatically by providing a sensor or the like. For example, excavator 4 may be provided with a sensor or GPS that measures the distance to the ground surface, and this may be used to detect that excavator 4 is located at the end of ridge 15. When it is detected that excavator 4 is located at the end of ridge 15, actuator 135 is retracted and the position of fall prevention member 111 is changed from the retracted position to the fall prevention position. Furthermore, when turning or the like is completed and excavator 4 enters ridge 15, a sensor or the like detects that excavator 4 is located at the entrance of ridge 15. When it is detected that excavator 4 is located at the entrance of ridge 15, actuator 135 is extended and the position of fall prevention member 111 is changed from the fall prevention position to the retracted position.

[0151] In this way, the position of the fall prevention member can be adjusted automatically without the hassle of manual operation, greatly improving the convenience of the excavator 4.

[0152] The digger 4 is equipped with a frame 17 connected to the traveling vehicle 2 by a lifting link mechanism (three-point link mechanism 3) so that it can be raised and lowered, and a digging tool 20 attached to the front of the frame 17.The digger 4 is equipped with a fall prevention device 110 provided with a fall prevention member 111 positioned on the digging tool 20 to prevent the crops 16 remaining in the digger 4 from falling forward from the digging tool 20 when the digger 4 moves forward together with the traveling vehicle 2 and is lifted from the working position (first position S1) in which the crops 16 are dug up by the digging tool 20.

[0153] This configuration prevents crops 16 from falling forward from digger 4 even when digger 4 is lifted and tilted. In other words, it is possible to reduce crops 16 falling to the ground when turning work implement 1, thereby preventing problems such as a reduced harvest yield of crops 16 by digger 4 and the hassle of picking up crops that have fallen into the field.

[0154] The fall prevention device 110 is equipped with a position changing device 112 that changes the position of the fall prevention member 111 between a fall prevention position, which is the position when the digger 4 is lifted, and a retracted position, which is a position where the digger 4 is retracted from the fall prevention position and which allows the digging up of the crops 16.

[0155] According to this configuration, by changing the position of the fall prevention member 111 using the position changing device 112, it is possible to switch (select) between a state in which the fall of the crop 16 can be prevented and a state in which the crop 16 can be harvested without being hindered by the fall prevention member 111.

[0156] The position change device 112 has a support 113 to which the fall prevention member 111 is attached and which is supported on the excavator 4 so as to be able to swing freely around an axis extending in the width direction K1 of the excavator 4, and a linkage member 114 which links the support 113 to a change in the attitude of the excavator 4 or the swing of the lifting link mechanism (three-point link mechanism 3) so as to swing the support 113 and change the position of the fall prevention member 111 between a fall prevention position and a retracted position.

[0157] With this configuration, the position of the fall prevention member 111 can be switched between the fall prevention position and the retracted position in conjunction with a change in posture of the excavator 4 or the swinging of the lifting link mechanism (three-point link mechanism 3) without any complicated operations.

[0158] The position changing device 112 may include a support 113 to which the fall prevention member 111 is attached and which is supported on the excavator 4 so as to be able to swing freely around an axis extending in the width direction K1 of the excavator 4, and an actuator 135 that swings the support 113 to change the position of the fall prevention member 111 between a fall prevention position and a retracted position.

[0159] According to this configuration, the actuator 135 can be extended or retracted at will by the operator electrically or hydraulically, so that the crops 16 can be prevented from falling regardless of whether the digger 4 is in a raised position. With the digger 4 using this type of actuator 135, the crops 16 can be prevented from falling even when an inertial force acts when the work implement 1 is stopped.

[0160] The support body 113 has a base end member 113a connected to the excavator 4, a tip end member 113b connected to the fall prevention member 111, a swing shaft 113c that pivots the tip end member 113b so that it can swing freely relative to the base end member 113a, and a regulating device 113d that allows the tip end member 113b to swing rearward beyond a predetermined position and prevents the tip end member 113b from swinging forward beyond the predetermined position.

[0161] According to this configuration, when support 113 comes into contact with the ground or the like and a backward force acts on fall prevention member 111, support 113 is allowed to swing backward, so it can deflect the force from the ground and prevent damage to position changing device 112. On the other hand, support 113 is restricted from swinging forward, so support 113 will not swing forward even if it receives a force that tries to drop crop 16, and it is possible to reliably prevent crop 16 from falling.

[0162] The fall prevention device 110 has a biasing member 113e that biases the tip member 113b relative to the base end member 113a in a direction in which the tip member 113b swings forward relative to the base end member 113a. are.

[0163] According to this configuration, the tip member 113b that has been swung forward can be swung backward using the biasing member 113e, and even if an external force is applied to the support body 113 from rear to front, the support body 113 can be swung forward to deflect the external force, and then automatically return to the state before the swing when the external force is no longer acting. This configuration is preferably used for the purpose of preventing damage to the fall prevention member 111, for example, when digging up crops 16 is resumed and the fall prevention member 111 in the fall prevention position comes into contact with the ridge 15 and is subjected to an external force.

[0164] The tip member 113b comprises a first member 118 connected to the fall prevention member 111, a second member 119 pivotally supported on the swing shaft 113c, and a connection part 120 that connects the first member 118 to the second member 119 so that the distance from the first member 118 to the second member 119 can be freely changed, and the length of the support body 113 from the base end to the tip end can be freely changed by the connection part 120.

[0165] According to this configuration, by changing the distance from the first member 118 to the second member 119, it is possible to change the position of the fall prevention member 111 in the vertical direction, and it is possible to adjust the position of the fall prevention member 111 to an appropriate height depending on the height of the field or the upper surface 15a of the ridge 15.

[0166] Although one embodiment of the present invention has been described above, the embodiment disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0167] 1 Work equipment (traveling vehicle) 3 Lifting link mechanism (three-point link mechanism) 4 Excavator 16 crops 17 machine frame 20 Digging tools 92 Posture adjustment mechanism 110 Fall protection device 111 Fall prevention member 111a Fall prevention plate 111b support 112 Position change device 113 Support 113a base end member 113b Tip member 113c swing axis 113d restrictor 113e biasing member 114 Interlocking members 118 First member 119 Second member 127 Interlocking shaft 135 Actuator S1 1st posture S2 Second posture (lifting posture)

Claims

1. An excavator comprising a machine frame connected to a traveling vehicle by a lifting link mechanism so as to be able to rise and fall, and a digging tool provided at the front of the machine frame, a fall prevention device provided with a fall prevention member that is positioned on the digging tool to prevent the crops remaining in the digging machine from falling forward from the digging tool when the digging machine moves forward together with the traveling vehicle and the digging machine is lifted from a working position in which the digging tool digs up crops; a position changing device that changes the position of the fall prevention member between a fall prevention position, which is the position when the digger is lifted, and a retracted position, which is a position retracted from the fall prevention position and is a position that allows the digging up of the crops; Equipped with The position changing device is A support to which the fall prevention member is attached and which is supported by the excavator so as to be swingable around an axis extending in the width direction of the excavator; An excavator having a linkage member that links the support body to a change in the attitude of the excavator or the swing of the lifting link mechanism so as to swing the support body and change the position of the fall prevention member between the fall prevention position and the retracted position.

2. The support is a base member connected to the excavator; a tip member connected to the fall prevention member; a swing shaft that pivotally supports the tip end member to be swingable relative to the base end member; 2. An excavator equipped with a fall prevention device as described in claim 1, further comprising: a restricting device that allows the tip member to swing rearward beyond a predetermined position and prevents the tip member from swinging forward beyond the predetermined position.

3. An excavator equipped with a fall prevention device as described in Claim 2, which has a biasing member that biases the tip member against the base member in a direction in which the tip member swings forward relative to the base member.

4. The tip member is a first member connected to the fall prevention member; a second member pivotally supported on the swing shaft; a connecting portion that connects the first member to the second member so that a distance from the first member to the second member is changeable; It is equipped with 4. The excavator equipped with a fall prevention device according to claim 3, wherein the length of the support from its base end to its tip end is freely changeable by the connecting portion.

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