paddy field operation machine

Abstract

The paddy field work machine has a rear axle box (20) which is disposed on the lower side relative to the rear of the machine frame (11) and is arranged in the left-right direction. It has a connecting member (50) that spans across the rear axle box (20) and the machine frame (11) and connects them, fixing the position of the rear axle box (20) relative to the machine frame (11). The connecting member (50) has: a first connecting portion (51) connected to the machine frame (11) and extending downward from the machine frame (11); and a second connecting portion (52) connected to the lower part of the first connecting portion (51) and connected to the rear axle box (20).

Description

Technical Field

[0001] This invention relates to the support structure of the rear axle box in a paddy field work machine. Background Technology

[0002] In a riding rice transplanter, which is an example of a paddy field work machine, as disclosed in Patent Document 1, the left and right front wheels are supported at the front of the body frame arranged in the front-rear direction, and the rear axle box that supports the left and right rear wheels is arranged in the left-right direction at the lower side of the rear of the body frame.

[0003] In the riding rice transplanter of Patent Document 1, the rear axle box is able to be rotatably supported on the machine frame.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2013-203232 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In the case of ride-on rice transplanters, a type in which the rear axle box is fixed to the machine frame and cannot be rolled is also being considered.

[0009] The purpose of this invention is to securely fix the rear axle box to the machine frame in a paddy field machine when the machine is configured to fix the rear axle box to the machine frame.

[0010] Methods for solving problems

[0011] The paddy field operation machine of the present invention comprises: a body frame arranged in a front-rear direction; left and right front wheels supported on the front of the body frame; a rear axle box supporting the left and right rear wheels, disposed below the rear of the body frame and arranged in a left-right direction; and a connecting member that spans the rear axle box and the body frame and connects them, and is capable of fixing the position of the rear axle box relative to the body frame. The connecting member has: a first connecting portion connected to the body frame and extending downward from the body frame; and a second connecting portion connected to the lower part of the first connecting portion and connected to the rear axle box.

[0012] According to the present invention, the rear axle box is fixed to the body frame via a connecting member. The connecting member has: a first connecting portion connected to the body frame and extending downward from the body frame; and a second connecting portion connected to the lower part of the first connecting portion and connected to the rear axle box.

[0013] Therefore, the connecting component is positioned in the space between the body frame and the rear axle box, spanning across the body frame and the rear axle box to connect them, thus firmly fixing the rear axle box to the body frame.

[0014] In this invention, preferably, the connecting member has: a front first connecting portion, which is connected to the body frame by crossing a portion of the second connecting portion that is forward of the front-rear central portion; and a rear first connecting portion, which is connected to the body frame by crossing a portion of the second connecting portion that is rear of the front-rear central portion.

[0015] According to the present invention, by providing a first connecting portion at the front and rear of the connecting member, and the connecting portion of the connecting member that is connected to the frame of the machine body spanning the front and rear, the load applied to the rear axle box can be supported, thereby effectively supporting the rear axle box.

[0016] In this invention, preferably, the second connecting portion is connected to the upper portion of the rear axle box and to at least one of the front and rear portions of the rear axle box.

[0017] According to the present invention, the second connecting portion of the connecting member is connected to the upper portion of the rear axle box; otherwise, the second connecting portion of the connecting member is connected to the front portion or the rear portion of the rear axle box, or both the front and rear portions. Thus, loads applied to the rear axle box in the longitudinal and vertical directions can be supported, effectively supporting the rear axle box.

[0018] In this invention, preferably, the paddy field machine is provided with: a connecting component on the right side, which spans across the right part of the rear axle box and the machine frame to connect; and a connecting component on the left side, which spans across the left part of the rear axle box and the machine frame to connect.

[0019] According to the present invention, by providing a connecting member on the right side and a connecting member on the left side, the connecting portion of the connecting member that connects to the frame of the machine body spans across the left and right sides, thus enabling the load applied to the rear axle box to be supported and effectively supporting the rear axle box.

[0020] In this invention, preferably, the rear axle box has: a central box; a right rear wheel support box supporting the right rear wheel and connected to the right side of the central box; and a left rear wheel support box supporting the left rear wheel and connected to the left side of the central box, wherein a second connecting portion of the right connecting member spans the central box and the right rear wheel support box, and a second connecting portion of the left connecting member spans the central box and the left rear wheel support box.

[0021] In paddy field operation machines, the rear axle box is sometimes configured as having a central box, a right rear wheel support box supporting the right rear wheel, and a left rear wheel support box supporting the left rear wheel. The right rear wheel support box is connected to the right side of the central box, and the left rear wheel support box is connected to the left side of the central box.

[0022] According to the present invention, the second connecting portion of the right-side connecting member spans the central housing and the right-side rear wheel support housing, thereby strengthening the connection between the central housing and the right-side rear wheel support housing. The second connecting portion of the left-side connecting member spans the central housing and the left-side rear wheel support housing, thereby strengthening the connection between the central housing and the left-side rear wheel support housing.

[0023] In this invention, preferably, a gearbox is provided that is connected to the front of the body frame, and includes: an output shaft supported on the gearbox in a manner that protrudes rearward from the gearbox; an input shaft supported on the rear axle box in a manner that protrudes forward from a portion between the left and right connecting members of the rear axle box; and a drive shaft that spans the output shaft and connects the input shaft, wherein power from the output shaft is transmitted to the input shaft via the drive shaft, and from the input shaft to the left and right rear wheels via a transmission mechanism inside the rear axle box.

[0024] In paddy field work machines, sometimes the gearbox is connected to the front of the machine frame, and a drive shaft is connected across the output shaft supported by the gearbox and the input shaft supported by the rear axle box. The power of the output shaft is transmitted to the input shaft via the drive shaft, and from the input shaft to the left and right rear wheels via the transmission mechanism inside the rear axle box.

[0025] According to the present invention, in the right-side connecting member that spans the right side of the rear axle box and the body frame, and the left-side connecting member that spans the left side of the rear axle box and the body frame, the portion between the left and right connecting members of the rear axle box is effectively utilized, and the input shaft is supported in a manner that protrudes forward from the rear axle box.

[0026] In this invention, preferably, the paddy field machine includes: a right-side connecting frame that spans across the right part of the rear axle box and connects to the portion of the machine frame that is forward of the rear axle box; and a left-side connecting frame that spans across the left part of the rear axle box and connects to the portion of the machine frame that is forward of the rear axle box.

[0027] According to the present invention, the right connecting frame and the left connecting frame are connected to the right and left parts of the rear axle box, thereby the connecting portions of the left and right connecting frames connected to the rear axle box span the left and right sides, thus enabling the support of the load applied to the rear axle box in the front-rear direction and effectively supporting the rear axle box.

[0028] In this invention, it is preferred that the transmission is connected to the front part of the body frame, and the front parts of the left connecting frame and the right connecting frame are connected to the lower part of the transmission than the body frame.

[0029] In paddy field machinery, the gearbox is sometimes connected to the front of the machine frame.

[0030] According to the present invention, the front portions of the left and right connecting frames are connected to a gearbox with sufficient strength, thereby supporting the front portions of the left and right connecting frames with sufficient strength.

[0031] According to the present invention, the rear axle box is disposed on the lower side relative to the rear of the engine frame, and the rear parts of the left and right connecting frames are connected to the rear axle box. The front parts of the left and right connecting frames are connected to the lower part of the gearbox relative to the engine frame, and the left and right connecting frames are disposed on the lower side relative to the engine frame when viewed from the side.

[0032] Thus, the upper body frame, the lower left and right connecting frames, the front gearbox, and the rear axle box form a quadrilateral frame when viewed from the side, which is advantageous in terms of improving the support strength of the rear axle box.

[0033] The left and right connecting frames also have the function of strengthening the body frame and strengthening the connection between the gearbox and the body frame. Therefore, they are advantageous in terms of improving the strength of the body frame and the connection strength between the gearbox and the body frame.

[0034] In this invention, preferably, the paddy field machine has a connecting bracket, which is connected to the front of the machine frame in a manner that extends downward from the front of the machine frame, the gearbox is connected to the connecting bracket, and the front of the left connecting frame and the right connecting frame is connected to the connecting bracket.

[0035] In paddy field work machines, when the gearbox is connected to the front of the machine frame, it is sometimes configured such that the connecting bracket is connected to the front of the machine frame, the gearbox is connected to the connecting bracket, and the gearbox is connected to the front of the machine frame via the connecting bracket.

[0036] According to the present invention, the front portions of the left and right connecting frames are connected to the connecting brackets and, via the connecting brackets, to the gearbox. Thus, the connecting brackets have the functions of connecting the gearbox to the engine block frame and connecting the connecting frames to the gearbox, which is advantageous in terms of structural simplification.

[0037] In this invention, preferably, the rear axle box has: a central box; a right rear wheel support box supporting the right rear wheel and connected to the right side of the central box; and a left rear wheel support box supporting the left rear wheel and connected to the left side of the central box, the rear part of the right connecting frame spanning the central box and the right rear wheel support box and connected thereto, and the rear part of the left connecting frame spanning the central box and the left rear wheel support box and connected thereto.

[0038] In paddy field operation machines, the rear axle box is sometimes configured as having a central box, a right rear wheel support box supporting the right rear wheel, and a left rear wheel support box supporting the left rear wheel. The right rear wheel support box is connected to the right side of the central box, and the left rear wheel support box is connected to the left side of the central box.

[0039] According to the present invention, the rear portion of the right-side connecting frame spans across the central housing and the right-side rear wheel support housing, thereby strengthening the connection between the central housing and the right-side rear wheel support housing. The rear portion of the left-side connecting frame spans across the central housing and the left-side rear wheel support housing, thereby strengthening the connection between the central housing and the left-side rear wheel support housing.

[0040] In this invention, preferably, the right connecting frame and the left connecting frame are arranged at an angle relative to the front-back direction when viewed from above, such that the distance between the right connecting frame and the left connecting frame in the left-right direction becomes narrower towards the front of the connecting frame.

[0041] According to the present invention, for example, when a front-to-back load is applied to the right side of the rear axle box, the right-side connecting frame can effectively support the load, and when a front-to-back load is applied to the left side of the rear axle box, the left-side connecting frame can effectively support the load. Attached Figure Description

[0042] Figure 1 This is a left view of a ride-on rice transplanter.

[0043] Figure 2 It is a bottom view of the engine frame, gearbox, and the area near the rear axle box.

[0044] Figure 3 It is a left view of the chassis frame, gearbox, and the area near the rear axle box.

[0045] Figure 4 From Figure 3 A top view taken along the IV-IV direction.

[0046] Figure 5 From Figure 3 The main view observed in the VV direction.

[0047] Figure 6 From Figure 3 The rear view viewed from the VI-VI direction.

[0048] Figure 7 From Figure 3 The rear view viewed from the VII-VII direction.

[0049] Figure 8 It is a 3D view of the fuselage frame, connecting brackets, and the area near the rear axle box. Detailed Implementation

[0050] Figures 1 to 8 The image shows a riding rice transplanter as an example of a paddy field work machine. F indicates the front, B indicates the rear, U indicates the top, D indicates the bottom, R indicates the right, and L indicates the left.

[0051] (Overall structure of a ride-on rice transplanter)

[0052] like Figure 1 As shown, the left and right square tubular fuselage frames 11 are arranged along the front-to-back direction. The left and right front wheels 1 are supported on the front of the fuselage frames 11, and the left and right rear wheels 2 are supported on the rear of the fuselage frames 11. A driver's seat 13 and a steering wheel 14 for steering the front wheels 1 are provided on the top of the fuselage frames 11.

[0053] At the rear of the machine frame 11, the linkage mechanism 3 is supported vertically and extends rearward, and a hydraulic cylinder 4 is provided for lifting and lowering the linkage mechanism 3. A rice transplanting device 5 is supported at the rear of the linkage mechanism 3.

[0054] (Overall structure of the rice transplanting device)

[0055] like Figure 1 As shown, the rice transplanting device 5 is equipped with a planting transmission box 6, a rotating box 7, a planting arm 8, a floating plate 9, and a seedling loading platform 10.

[0056] Three planting transmission boxes 6 are arranged at a predetermined interval in the left and right direction. At the rear right and left of the planting transmission box 6, the rotating box 7 is supported to be rotatable, and a pair of planting arms 8 are rotatably supported at both ends of the rotating box 7.

[0057] As the seedling loading platform 10 is driven to reciprocate laterally to the left and right, the rotating box 7 is fed towards... Figure 1Driven by the counterclockwise rotation, the two sets of planting arms 8 alternately take out seedlings from the lower part of the seedling loading platform 10 and plant them on the field ground.

[0058] (Structure of a driving transmission system that drives the front and rear wheels)

[0059] like Figure 1 , 2 As shown in Figure 3, a gearbox 12 is connected to the front of the body frame 11, and an engine 16 is supported on a support frame 15 connected to the front of the gearbox 12.

[0060] A hydrostatic continuously variable transmission (CVT) 17 is connected to the left lateral side of the gearbox 12, and the power of the engine 16 is transmitted to the CVT 17 via a transmission belt 18. The CVT 17 is configured to continuously shift gears to the neutral position, forward direction, and reverse direction, and can be operated by a gear lever 19 located on the left lateral side relative to the steering wheel 14.

[0061] like Figure 2 as well as Figure 3 As shown, the power of the continuously variable transmission 17 is transmitted from the auxiliary transmission (not shown) and the front differential (not shown) inside the gearbox 12 to the left and right front wheels 1. The output shaft 23 is supported at the rear of the gearbox 12 in a manner that protrudes rearward from the gearbox 12, and the power from the branch directly in front of the front differential is transmitted to the output shaft 23.

[0062] The rear axle box 20, which supports the left and right rear wheels 2, is connected to the rear of the machine frame 11, and the input shaft 24 is supported at the front of the rear axle box 20 in such a way that it protrudes forward from the rear axle box 20.

[0063] The drive shaft 25 is connected to the output shaft 23 via a universal joint 26, and to the input shaft 24 via a collar 27 through a spline structure. The drive shaft 25 spans the output shaft 23 and the input shaft 24.

[0064] The power from the output shaft 23 is transmitted to the input shaft 24 via the drive shaft 25, and from the input shaft 24 to the left and right rear wheels 2 as described later in the section on the structure of the rear axle box.

[0065] (Structure of the planting transmission system that drives the rice transplanter)

[0066] like Figure 1 as well as Figure 3 As shown, inside the gearbox 12, there is a plant spacing transmission device (not shown) and a planting clutch (not shown). Power is transmitted from the continuously variable transmission device 17 and the auxiliary transmission device (refer to the above-described structure of the driving transmission system with front and rear wheel drive) to the plant spacing transmission device.

[0067] like Figure 1 , 3 As shown in Figures 7 and 8, the planting output shaft 47 is supported on the upper part of the gearbox 12 relative to the output shaft 23 in a manner that protrudes rearward from the gearbox 12. The power of the plant spacing transmission device is transmitted to the planting output shaft 47 via the planting clutch.

[0068] The planting drive shaft 48 is connected to the planting output shaft 47, extends rearward above the drive shaft 25 and above the rear axle box 20, and is connected to the rice transplanting device 5. The power of the planting output shaft 47 is transmitted to the rice transplanting device 5 via the planting drive shaft 48.

[0069] (Structure related to the support of the front wheels)

[0070] like Figure 1 , 2 As shown in Figure 3, left and right front axle boxes 28 are connected to the right and left transverse portions of the gearbox 12. The right front wheel support box 29, which supports the right front wheel 1, is supported on the right front axle box 28 in a manner that allows it to rotate about an axle in the vertical direction and slide up and down. The left front wheel support box 29, which supports the left front wheel 1, is supported on the left front axle box 28 in a manner that allows it to rotate about an axle in the vertical direction and slide up and down.

[0071] Inside the left and right front axle boxes 28, there are left and right suspension springs (not shown) that support the left and right front wheel support boxes 29, and the left and right front wheels 1 are independently supported by the suspension.

[0072] As described above (structure of the driving transmission system with front and rear wheel drive), the power of the continuously variable transmission 17 is transmitted from the auxiliary transmission device inside the gearbox 12 and the front wheel differential device to the left and right front wheels 1 via the drive shaft (not shown) inside the front axle box 28, the drive shaft (not shown) inside the front wheel support box 29, and the transmission gear (not shown).

[0073] The trapezoidal steering component 30, when viewed from above, is supported on the lower part of the gearbox 12 in a manner that allows it to swing around the shaft P1 along the vertical direction. The arm 29a spanning the steering component 30 and the left and right front wheel support boxes 29 is connected to the left and right tie rods 31.

[0074] By operating the steering wheel 14, the steering component 30 is swung left and right, and the front wheel 1 is turned left and right via the steering component 30 and the lever 31.

[0075] (Structure of the rear axle box)

[0076] like Figure 1 , 2As shown in Figure 3, the rear axle box 20 is positioned on the lower side relative to the rear of the machine frame 11, and is arranged along the left-right direction. The rear axle box 20 is configured such that the input shaft 24 is located slightly lower than the output shaft 23.

[0077] like Figure 4 , 5 As shown in Figure 6, the rear axle box 20 has a central box 21 made of aluminum, a right rear wheel support box 22 supporting the right rear wheel 2, and a left rear wheel support box 22 supporting the left rear wheel 2.

[0078] The flange 21b on the right side of the central housing 21 is bolted to the flange 22a of the right rear wheel support housing 22, and the right rear wheel support housing 22 is connected to the right side of the central housing 21. The flange 21b on the left side of the central housing 21 is bolted to the flange 22a of the left rear wheel support housing 22, and the left rear wheel support housing 22 is connected to the left side of the central housing 21.

[0079] like Figure 3 , 4 As shown in Figure 5, a boss 21a is provided at the front of the left and right central parts of the central housing 21, facing forward and diagonally upward. The input shaft 24 is supported on the boss 21a. Thus, the input shaft 24 and the transmission shaft 25 are arranged in a straight line when viewed from the side (see Figure 5). Figure 3 Even without using the universal joint 26, the drive shaft 25 can be connected to the input shaft 24 via the collar 27.

[0080] like Figure 2 As shown, inside the central housing 21 and the left and right rear wheel support housings 22, the rear wheel drive shafts 32 (equivalent to a transmission mechanism) are supported along the left and right directions. A bevel gear 24a is provided on the input shaft 24, and a bevel gear 32a is connected to the rear wheel drive shaft 32. The bevel gear 24a of the input shaft 24 meshes with the bevel gear 32a of the rear wheel drive shaft 32.

[0081] Inside the left and right rear wheel support boxes 22, on the right and left sides of the rear wheel drive shaft 32, there are left and right side clutches 33 (equivalent to transmission mechanisms). The rear wheel support boxes 22 are equipped with a drive shaft 34 (equivalent to a transmission mechanism) and an axle 35 (equivalent to a transmission mechanism), and the rear wheel 2 is connected to the axle 35.

[0082] The power transmitted to the input shaft 24 is transmitted to the left and right rear wheels 2 via the bevel gear 24a of the input shaft 24, the bevel gear 32a of the rear wheel drive shaft 32, the rear wheel drive shaft 32, the side clutch 33, the drive shaft 34, and the axle 35.

[0083] (Structure of the side clutch operating system)

[0084] like Figure 2 as well as Figure 3 As shown, the side clutch 33 is forced into the transmission state by an internal spring (not shown). The left and right operating shafts 36, which can operate the side clutch 33 to the disengaged state, are supported downward on the lower right and left parts of the rear axle box 20 (central box 21).

[0085] The steering component 30 (refer to the structure related to the support of the front wheels described above) is connected to the arms 36a of the left and right operating shafts 36 via left and right connecting members 37. In this case, the connecting member 37 is connected to the arms 36a of the operating shaft 36 by inserting a pin of the arm 36a of the operating shaft 36 into the elongated through-hole 37a provided at the rear of the connecting member 37.

[0086] like Figure 2 As shown, the steering component 30 (front wheel 1) can perform steering operations between the straight position A1 and the left and right limit positions A3. When the steering component 30 (front wheel 1) is steering within a set angle A2 to the left and right of the straight position A1, the operating shaft 36 is not operated by the fusion part 37a of the connecting component 37, and the left and right side clutches 33 are operated in the transmission state to transmit power to the left and right rear wheels 2.

[0087] When the steering component 30 (front wheel 1) exceeds the set angle A2 on the right (left) side and is turned to the right (left), the connecting component 37 on the right (left) side is pulled towards the steering component 30, the operating shaft 36 on the right (left) side is rotated, and the side clutch 33 on the right (left) side is operated to the disengaged state.

[0088] Thus, power is transmitted to the rear wheel 2 on the outside of the turn, and the right turn (left turn) is performed while the rear wheel 2 on the center side of the turn is freely rotating. When the steering component 30 (front wheel 1) is turned within the range of the set angle A2 on the left and right, the right (left) side clutch 33 is operated into the transmission state, returning to the state of transmitting power to the left and right rear wheels 2.

[0089] (Structure of connecting brackets)

[0090] like Figure 2 as well as Figure 3 As shown, a connecting bracket 40 is provided that connects to the front part of the left and right fuselage frames 11. Figure 3 , 7 As shown in Figure 8, the connecting bracket 40 has a left and right first part 41, a left and right second part 42, a third part 43, and a left and right fourth part 44.

[0091] The first left and right portions 41 are angular in shape and arranged vertically. The fourth left and right portions 44 are connected to the upper part of the first portion 41 by welding. The second left and right portions 42 are channel-shaped and connected to the lower part of the first portion 41 by welding, extending rearward from the lower part of the first portion 41. The third portion 43 is angular in shape and is connected to the second left and right portions 42 by welding.

[0092] (The structure that supports the gearbox via the connecting bracket)

[0093] like Figure 3 , 7 As shown in Figure 8, the left and right fourth parts 44 of the connecting bracket 40 and the front parts of the left and right body frames 11 are connected to the left and right bosses 12a of the gearbox 12 by bolts 38. The left and right first parts 41 of the connecting bracket 40 are connected to the left and right bosses 12b of the gearbox 12 by bolts 39.

[0094] At the lower rear part of the gearbox 12, a connecting part 12c is provided so as to extend rearward from the gearbox 12. The connecting part 12c is inserted between the left and right second parts 42 of the connecting bracket 40 and abuts against the third part 43 of the connecting bracket 40.

[0095] The second part 42 of the connecting bracket 40 is connected to the connecting part 12c of the gearbox 12 by bolts 45. The third part 43 of the connecting bracket 40 is connected to the connecting part 12c of the gearbox 12 by bolts 46.

[0096] Thus, the connecting bracket 40 is connected to the front of the fuselage frame 11 in a manner that extends downward from the front of the fuselage frame 11. The gearbox 12 is connected to the connecting bracket 40 and is connected to the front of the fuselage frame 11 via the connecting bracket 40.

[0097] (The structure of the connecting parts on the left and right)

[0098] like Figure 1 as well as Figure 3 As shown, left and right connecting parts 50 are provided, which span across the rear axle box 20 and the body frame 11 and connect them, thereby fixing the position of the rear axle box 20 relative to the body frame 11.

[0099] like Figure 3 as well as Figure 8 As shown, the left and right connecting parts 50 have two first connecting parts 51 in the shape of square tubes and a second connecting part 52 formed by bending the sheet metal into a box shape. The left and right connecting parts 50 are configured to be symmetrical.

[0100] like Figure 4 , 5As shown in Figures 6 and 8, in the connecting member 50, the second connecting portion 52 has a planar upper portion 52a, a planar front portion 52b, and a planar rear portion 52c. The front first connecting portion 51 is connected to the portion of the second connecting portion 52 (upper portion 52a) that is forward of the front-rear center portion by welding, and the rear first connecting portion 51 is connected to the portion of the second connecting portion 52 (upper portion 52a) that is rear of the front-rear center portion by welding. The second connecting portion 52 is connected to the lower portion of the first connecting portion 51.

[0101] (The structure of the left and right connecting parts supporting the rear axle box)

[0102] like Figure 4 , 5 As shown in Figures 6 and 8, in the left and right connecting parts 50, the first connecting part 51 is connected to the lower surface of the rear part of the body frame 11 by welding and extends downward from the body frame 11. The second connecting part 52 is connected to the rear axle box 20 as described below.

[0103] Thus, in the connecting component 50, the front first connecting part 51 spans the front part of the second connecting part 52 and the body frame 11 and is connected, and the rear first connecting part 51 spans the rear part of the second connecting part 52 and the body frame 11 and is connected.

[0104] like Figure 4 , 5 As shown in Figure 6, in the rear axle box 20, connecting portions 21c (corresponding to the upper part of the rear axle box 20) are formed upward on the upper right and left parts of the central box 21. Connecting portions 21d (corresponding to the front part of the rear axle box 20) and 21e are formed forward on the front right and left parts of the central box 21. Connecting portions 21f (corresponding to the rear part of the rear axle box 20) are formed rearward on the rear right and left parts of the central box 21.

[0105] In the rear axle box 20, a connecting portion 22b (corresponding to the upper part of the rear axle box 20) is formed upward at the upper part of the left and right rear wheel support boxes 22. A connecting portion 22c is formed forward at the front part of the left and right rear wheel support boxes 22. A connecting portion 22d (corresponding to the rear part of the rear axle box 20) is formed rearward at the rear part of the left and right rear wheel support boxes 22.

[0106] In the connecting component 50 on the right side, the upper part 52a of the second connecting part 52 is connected to the connecting part 21c on the right side of the central box 21 (rear axle box 20) and the connecting part 22b on the right side of the rear wheel support box 22 (rear axle box 20) by bolts 53.

[0107] In the connecting component 50 on the right, the front part 52b of the second connecting part 52 is connected to the connecting part 21d on the right side of the central box 21 (rear axle box 20) by bolts 54.

[0108] The rear part 52c of the second connecting part 52 is connected to the connecting part 21f on the right side of the central box 21 (rear axle box 20) and the connecting part 22d on the right side of the rear wheel support box 22 (rear axle box 20) by bolts 55.

[0109] In the connecting component 50 on the left, the upper part 52a of the second connecting part 52 is connected to the connecting part 21c on the left side of the central box 21 (rear axle box 20) and the connecting part 22b on the left side of the rear wheel support box 22 (rear axle box 20) by bolts 53.

[0110] In the connecting component 50 on the left, the front part 52b of the second connecting part 52 is connected to the connecting part 21d on the left side of the central box 21 (rear axle box 20) by bolts 54.

[0111] The rear part 52c of the second connecting part 52 is connected to the connecting part 21f on the left side of the central box 21 (rear axle box 20) and the connecting part 22d on the left side of the rear wheel support box 22 (rear axle box 20) by bolts 55.

[0112] Therefore, as Figure 4 , 5 As shown in Figures 6 and 8, the connecting component 50 on the right side spans across the right part of the rear axle box 20 and the right side of the body frame 11, and also spans across the connecting component 50 on the left side, the left part of the rear axle box 20 and the left side of the body frame 11.

[0113] The second connecting portion 52 of the connecting member 50 on the right side crosses the flange portion 21b on the right side of the central box 21 and the flange portion 22a on the right side of the rear wheel support box 22, and is connected across the central box 21 and the rear wheel support box 22 on the right side.

[0114] The second connecting portion 52 of the left connecting member 50 crosses the left flange portion 21b of the central box 21 and the flange portion 22a of the left rear wheel support box 22, and is connected across the central box 21 and the left rear wheel support box 22.

[0115] The boss 21a of the input shaft 24 and the central box 21 protrudes forward from the part between the left and right connecting parts 50 of the rear axle box 20 (central box 21).

[0116] (The structure of the left and right connecting frames)

[0117] like Figure 1 , 2As shown in Figure 3, left and right connecting frames 56 are provided, spanning the gearbox 12 and the rear axle box 20. The left and right connecting frames 56 are configured to be symmetrical.

[0118] like Figure 8 As shown, in the connecting frame 56, a square tubular main body 57 is provided, and a channel-shaped front connecting part 58 (equivalent to the front part of the connecting frame) is welded to the front part of the main body 57. A box-shaped rear connecting part 59 (equivalent to the rear part of the connecting frame) formed by bending a sheet metal is welded to the rear part of the main body 57. A reinforcing plate 60 spans the main body 57 and the rear connecting part 59 and is connected to the upper and lower parts by welding.

[0119] (The structure of the left and right connecting frames supporting the rear axle box)

[0120] like Figure 3 as well as Figure 8 As shown, the front connecting part 58 of the connecting frame 56 on the right side is connected to the second part 42 on the right side of the connecting bracket 40 by bolts 49 (refer to the above (structure of the connecting bracket) and (structure of the connecting bracket supporting the gearbox)).

[0121] The front connecting part 58 of the left connecting frame 56 is connected to the second part 42 on the left side of the connecting bracket 40 by bolts 49 (refer to the above (structure of the connecting bracket) and (structure of the connecting bracket supporting the gearbox)).

[0122] like Figure 4 , 5 As shown in Figure 8, the rear connecting part 59 of the connecting frame 56 on the right side is connected to the connecting part 21e on the right side of the central box 21 (rear axle box 20) and the connecting part 22c on the right side of the rear wheel support box 22 (rear axle box 20) by bolts 61 (refer to the above-described (structure of the left and right connecting parts supporting the rear axle box)).

[0123] The rear connecting part 59 of the left connecting frame 56 is connected to the left connecting part 21e of the central box 21 (rear axle box 20) and the connecting part 22c of the left rear wheel support box 22 (rear axle box 20) by bolts 61 (refer to the above (structure of the left and right connecting parts supporting the rear axle box)).

[0124] Therefore, as Figure 2 , 3 As shown in Figure 8, the right-side connecting frame 56 spans the right side of the rear axle box 20 and connects the front portion of the body frame 11 to the rear axle box 20. The left-side connecting frame 56 spans the left side of the rear axle box 20 and connects the front portion of the body frame 11 to the rear axle box 20.

[0125] In this case, the left and right connecting frames 56 are connected to the body frame 11 via the gearbox 12 and the connecting bracket 40.

[0126] The front connecting part 58 of the left and right connecting frames 56 is connected to the lower part of the gearbox 12 than the body frame 11 by connecting the connecting bracket 40 (second part 42).

[0127] like Figure 4 , 5 As shown in Figure 8, the rear connecting portion 59 of the connecting frame 56 on the right side crosses the flange portion 21b on the right side of the central box 21 and the flange portion 22a on the right side of the rear wheel support box 22, and is connected across the central box 21 and the rear wheel support box 22 on the right side.

[0128] The rear connecting portion 59 of the left connecting frame 56 crosses the left flange portion 21b of the central box 21 and the flange portion 22a of the left rear wheel support box 22, and is connected across the central box 21 and the left rear wheel support box 22.

[0129] like Figure 2 as well as Figure 8 As shown, the right and left connecting frames 56 are arranged at an angle relative to the front and back directions, with the left and right distance between the right and left connecting frames 56 narrowing towards the front of the connecting frames 56.

[0130] (First Other Embodiment of the Invention)

[0131] The connecting component 50 on the right side can be connected only to the central box 21 of the rear axle box 20, or only to the rear wheel support box 22 on the right side of the rear axle box 20.

[0132] The connecting component 50 on the left side can be connected only to the central box 21 of the rear axle box 20, or only to the rear wheel support box 22 on the left side of the rear axle box 20.

[0133] In the configuration described above, the central box 21 and the left and right rear wheel support boxes 22 can be made of the same material.

[0134] (Second embodiment of the invention)

[0135] Alternatively, in the connecting member 50 on the right side, the two first connecting portions 51 are eliminated, and a first connecting portion 51 with a rectangular cross-section is provided, with the long side of the rectangular cross-section of the first connecting portion 51 arranged along the front-back direction. In this case, the length of the long side of the rectangular cross-section of the first connecting portion 51 can be set to be approximately the same as the front-back width of the second connecting portion 52 (upper portion 52a).

[0136] Alternatively, in the left connecting member 50, the two first connecting portions 51 are eliminated, and a first connecting portion 51 with a rectangular cross-section is provided, with the long side of the rectangular cross-section of the first connecting portion 51 arranged along the front-back direction. In this case, the length of the long side of the rectangular cross-section of the first connecting portion 51 can be set to be approximately the same as the front-back width of the second connecting portion 52 (upper portion 52a).

[0137] (Third other embodiment of the present invention)

[0138] Alternatively, in the connecting member 50 on the right side, the front portion 52b of the second connecting part 52 is eliminated, and the second connecting part 52 is not connected to the connecting part 21d on the right side of the central box 21 (rear axle box 20).

[0139] Alternatively, in the connecting member 50 on the right side, the rear portion 52c of the second connecting part 52 is eliminated, and the second connecting part 52 is not connected to the connecting part 21f on the right side of the central box 21 (rear axle box 20), nor to the connecting part 22d on the right side of the rear wheel support box 22 (rear axle box 20).

[0140] Alternatively, in the connecting member 50 on the left, the front portion 52b of the second connecting part 52 is eliminated, and the second connecting part 52 is not connected to the connecting part 21d on the left side of the central box 21 (rear axle box 20).

[0141] Alternatively, in the connecting member 50 on the left side, the rear portion 52c of the second connecting part 52 is eliminated, and the second connecting part 52 is not connected to the connecting part 21f on the left side of the central box 21 (rear axle box 20), nor to the connecting part 22d on the left side of the rear wheel support box 22 (rear axle box 20).

[0142] (Fourth other embodiment of the present invention)

[0143] It can also connect to the reinforcing component (not shown) across the left and right connecting parts 50.

[0144] In this structure, with the reinforcing member considered as part of the connecting member 50, a connecting member 50 is provided by the left and right connecting members 50 and the reinforcing member.

[0145] (Fifth other embodiment of the present invention)

[0146] In the rear axle box 20, if the material of the central box 21 is different from the material of the left and right rear wheel support boxes 22, it can also be configured as described below.

[0147] In the connecting component 50 on the right side, the connection area (number of bolts 53, 54, 55) of the second connecting part 52 to the central box 21 is set to be different from the connection area (number of bolts 53, 54, 55) of the second connecting part 52 to the rear wheel support box 22 on the right side.

[0148] In the connecting component 50 on the right, the tightening torque of the bolts 53, 54, and 55 of the second connecting part 52 toward the central box 21 is set to be different from the tightening torque of the bolts 53, 54, and 55 of the second connecting part 52 toward the rear wheel support box 22 on the right.

[0149] In the connecting component 50 on the left, the connecting area (number of bolts 53, 54, 55) of the second connecting part 52 to the central box 21 is set to be different from the connecting area (number of bolts 53, 54, 55) of the second connecting part 52 to the rear wheel support box 22 on the left.

[0150] In the left-side connecting component 50, the tightening torque of the bolts 53, 54, and 55 of the second connecting part 52 toward the central box 21 is set to be different from the tightening torque of the bolts 53, 54, and 55 of the second connecting part 52 toward the left-side rear wheel support box 22.

[0151] (Sixth other embodiment of the present invention)

[0152] The left and right link frames can also be abolished. (56)

[0153] According to this structure, the reinforcing frame can be connected by spanning the lower part of the connecting bracket 40 and the front and rear middle parts of the body frame 11. Alternatively, the front part 52b of the second connecting part 52 of the connecting component 50 can be connected to the front part of the rear wheel support box 22.

[0154] (Seventh other embodiment of the present invention)

[0155] Alternatively, the front connecting part 58 of the connecting frame 56 can be connected to the front and rear middle parts of the body frame 11 instead of the gearbox 12 (connecting bracket 40).

[0156] (Eighth other embodiment of the present invention)

[0157] The rear connecting part 59 of the connecting frame 56 on the right side can be connected only to the central box 21 of the rear axle box 20, or only to the rear wheel support box 22 on the right side of the rear axle box 20.

[0158] The rear connecting part 59 of the left connecting frame 56 can be connected only to the central box 21 of the rear axle box 20, or only to the rear wheel support box 22 on the left side of the rear axle box 20.

[0159] (Ninth other embodiment of the present invention)

[0160] Alternatively, the right and left connecting frames 56 can be configured to be parallel in the front-to-back direction when viewed from above, with the left-to-right spacing of the right connecting frame 56 and the left connecting frame 56 being the same in any part of the connecting frame 56.

[0161] Alternatively, the right and left connecting frames 56 can be configured to tilt relative to the front-back direction when viewed from above, with the left-right spacing between the right and left connecting frames 56 becoming wider towards the front of the connecting frame 56.

[0162] (Tenth Other Embodiment of the Invention)

[0163] Alternatively, instead of supporting the left and right front wheels 1 on the gearbox 12, a front axle box (not shown) is provided to support the left and right front wheels 1, and the front axle box is rotatably supported on the front of the body frame 11.

[0164] Industrial applicability

[0165] This invention can be applied not only to riding rice transplanters, but also to riding seeders equipped with seeding devices that supply seeds to the field surface, riding sprayers equipped with pesticide spraying devices that spray pesticides onto the field surface, and other paddy field operation machines.

[0166] Explanation of reference numerals in the attached figures

[0167] 1 front wheel

[0168] 2 rear wheels

[0169] 11. Body Frame

[0170] 12-speed gearbox

[0171] 20 rear axle box

[0172] 21 Central Box

[0173] 21c Connector (Upper Part)

[0174] 21d Connector (Front Part)

[0175] 21f Connector (Rear Part)

[0176] 22 Rear wheel support box

[0177] 22b Connector (Upper Part)

[0178] 22d Connector (Rear Part)

[0179] 23 Output Shaft

[0180] 24 input axes

[0181] 25 drive shaft

[0182] 32 Rear wheel drive shaft (transmission mechanism)

[0183] 33-sided clutch (transmission mechanism)

[0184] 34. Drive shaft (transmission mechanism)

[0185] 35 axle (transmission mechanism)

[0186] 40 connecting brackets

[0187] 50 connecting parts

[0188] 51 First Linkage Section

[0189] 52 Second Connecting Section

[0190] 56-link frame

[0191] 58. Front Connector (Front Section)

[0192] 59 Rear Connector (Rear Section)

Claims

1. A paddy field working machine, wherein, The paddy field working machine is provided with: a machine body frame disposed along a front-rear direction; left and right front wheels supported at a front portion of the machine body frame; a rear axle box supporting left and right rear wheels, disposed at a lower side with respect to a rear portion of the machine body frame, and disposed along a left-right direction; and a link member linking across the rear axle box and the machine body frame, capable of fixing a position of the rear axle box with respect to the machine body frame, the link member has a first link portion linked with the machine body frame and extending downward from the machine body frame, and a second link portion linked with a lower portion of the first link portion and linked with the rear axle box, an upper portion of the first link portion is linked with a lower surface portion of the machine body frame, and a lower portion of the first link portion is linked with an upper portion of the second link portion, the second link portion is linked with an upper portion of the rear axle box, and linked with at least either a front portion or a rear portion of the rear axle box.

2. A paddy field working machine, wherein, The paddy field working machine is provided with: a machine body frame disposed along a front-rear direction; left and right front wheels supported at a front portion of the machine body frame; a rear axle box supporting left and right rear wheels, disposed at a lower side with respect to a rear portion of the machine body frame, and disposed along a left-right direction; a right-side link member linking across a right portion of the rear axle box and the machine body frame, capable of fixing a position of the rear axle box with respect to the machine body frame; and a left-side link member linking across a left portion of the rear axle box and the machine body frame; the rear axle box has a central box, a right-side rear wheel support box supporting the right-side rear wheel and linked with a right portion of the central box, and a left-side rear wheel support box supporting the left-side rear wheel and linked with a left portion of the central box, the left and right link members have a first link portion linked with the machine body frame and extending downward from the machine body frame, and a second link portion linked with a lower portion of the first link portion, the second link portion of the right-side link member links across the central box and the right-side rear wheel support box, the second link portion of the left-side link member links across the central box and the left-side rear wheel support box.

3. The paddy field working machine according to claim 1 or 2, wherein the link member has a front-side first link portion linking across a portion of the second link portion on a front side of a front-rear central portion and the machine body frame, and a rear-side first link portion linking across a portion of the second link portion on a rear side of the front-rear central portion and the machine body frame.

4. The paddy field working machine according to claim 2, wherein ​ The second connecting portion is connected to an upper portion of the rear axle case and at least one of a front portion and a rear portion of the rear axle case.

5. The paddy field working machine according to claim 1, wherein The paddy field working machine is provided with: the right connecting member connecting across the right portion of the rear axle case and the machine body frame; and the left connecting member connecting across the left portion of the rear axle case and the machine body frame.

6. The paddy field working machine according to claim 5, wherein the rear axle case has a central case, a right rear wheel support case supporting the right rear wheel and connected to a right portion of the central case, and a left rear wheel support case supporting the left rear wheel and connected to a left portion of the central case, the second connecting portion of the right connecting member connects across the central case and the right rear wheel support case, the second connecting portion of the left connecting member connects across the central case and the left rear wheel support case.

7. The paddy field working machine according to claim 1, wherein The paddy field working machine is provided with: a right connecting frame connecting across a right portion of the rear axle case and a portion of the machine body frame that is forward of the rear axle case; and a left connecting frame connecting across a left portion of the rear axle case and a portion of the machine body frame that is forward of the rear axle case.

8. The paddy field working machine according to claim 7, wherein The paddy field working machine is provided with a transmission case connected to a front portion of the machine body frame, front portions of the left and right connecting frames are connected to a portion of the transmission case that is downward of the machine body frame.

9. The paddy field working machine according to claim 8, wherein The paddy field working machine is provided with a connecting bracket connected to a front portion of the machine body frame in a manner extending downward from the front portion of the machine body frame, the transmission case is connected to the connecting bracket, front portions of the left and right connecting frames are connected to the connecting bracket.

10. The paddy field working machine according to claim 7, wherein The rear axle case has a central case, a right rear wheel support case supporting the right rear wheel and connected to a right portion of the central case, and a left rear wheel support case supporting the left rear wheel and connected to a left portion of the central case, a rear portion of the right connecting frame connects across the central case and the right rear wheel support case, a rear portion of the left connecting frame connects across the central case and the left rear wheel support case.

11. The paddy field working machine according to claim 7, wherein The right and left connecting frames are inclined with respect to a front-rear direction in plan view, such that a separation between the right and left connecting frames in a left-right direction is narrower toward a front side of the connecting frames.

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