Farm work machine

Abstract

To provide a mowing work machine in which lubricant is prevented from leaking.SOLUTION: A mowing work machine 1 is a farm work machine used by being connected to a rear part of a tractor. The mowing work machine includes a vertically rotatable work part 6 that performs work according to power from a power transmission part 18. The work part 6 includes a gear case 54, and a tubular body 113 connected to a connection port 111 of the gear case 54. An exhaust port 112 of the tubular body 113 is located in an upper part from an oil level S of lubricant regardless of whether the work part 6 is in a horizontal posture or an inclined posture.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an agricultural machine. [Background technology]

[0002] BACKGROUND ART Conventionally, a grass cutting machine, which is an agricultural machine, is known, for example, as described in Patent Document 1 below.

[0003] This conventional brush cutting machine is used by connecting it to the rear of a tractor, which is a traveling vehicle, and is equipped with a power transmission unit that transmits power from the tractor, and a working unit that can rotate up and down to perform brush cutting work based on the power from this power transmission unit.

[0004] The working unit also has a case body (gear case portion) that houses part of the power transmission unit and stores lubricating oil, and an exhaust port is formed on the upper surface of this case body, and this exhaust port is closed by a valved cap. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-183637 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the conventional brush cutter, for example, when the working unit rotates and assumes an inclined position, the exhaust port of the case body may be positioned below the level of the lubricating oil inside the case body. In such a case, if the pressure inside the case body increases due to temperature changes or the like, there is a risk of the lubricating oil leaking out of the exhaust port.

[0007] One of the objects of the embodiments of the present invention is to provide an agricultural work machine that can prevent leakage of lubricating oil. [Means for solving the problem]

[0008] An agricultural work machine according to an embodiment of the present invention comprises a power transmission unit that transmits power, and a working unit that performs work based on the power from the power transmission unit, and the working unit comprises a case body that houses at least a portion of the power transmission unit and stores lubricating oil, and has a connection port, and a tubular body that is connected to the connection port of the case body and has an exhaust port at its tip, and the exhaust port is located above the oil level of the lubricating oil regardless of whether the working unit is in a horizontal position or an inclined position. [Effects of the Invention]

[0009] According to the embodiment of the present invention, leakage of lubricating oil can be prevented. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a side view of a brush cutter according to an embodiment of the present invention. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] 1A and 1B are diagrams showing the rotational movement of the working unit, in which (a) is a diagram showing the working unit in the maximum upward tilt position when it is in the maximum upward tilt position, and (b) is a diagram showing the working unit in the maximum downward tilt position when it is in the maximum downward tilt position. [Figure 6] 1A, 1B, and 1C are diagrams showing a gear case portion of the same brush cutter, in which (a) is a front view, (b) is a side view, and (c) is a plan view. [Figure 7] FIG. 6(b) is an enlarged partial cross-sectional view taken along the line AA in FIG. [Figure 8] FIG. 8 is an enlarged cross-sectional view of part C in FIG. 7. [Figure 9] FIG. 6(b) is an enlarged partial cross-sectional view taken along line BB in FIG. 6(a). [Figure 10] FIG. 4 is a perspective view showing a closing member that closes an opening of a gear case of the working unit. [Figure 11] 1 is a schematic diagram showing the positional relationship between the exhaust port and the lubricating oil level of the same brush cutter, where (a) is a diagram when the working unit is in a horizontal position, (b) is a diagram when the working unit is in a maximum upward tilt position, and (c) is a diagram when the working unit is in a maximum downward tilt position. [Figure 12] 10A and 10B are schematic diagrams showing the positional relationship between the exhaust port and the lubricating oil level in a brush cutter according to another embodiment of the present invention, where (a) is a diagram showing the working unit in a horizontal position, (b) is a diagram showing the working unit in a maximum upward tilt position, and (c) is a diagram showing the working unit in a maximum downward tilt position. [Figure 13] FIG. 12(b) is an enlarged cross-sectional view of part D in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present invention will be described with reference to FIGS.

[0012] In the drawing, reference numeral 1 denotes a grass cutting machine, which is an agricultural work machine, and this grass cutting machine 1 is a flail mower that is used by being connected (mounted) to the rear of a tractor (not shown), which is a traveling vehicle.

[0013] That is, the mowing machine 1 is detachably connected to the rear of the tractor, and moves forward (in the direction of travel) as the tractor travels, performing predetermined work, i.e., mowing work (agricultural work).

[0014] More specifically, the grass cutting implement 1 is connected to a three-point linkage (agricultural implement mounting device) at the rear of the tractor, and moves forward as the tractor travels forward, cutting and shredding the grass to be cut (for example, weeds, straw, second ears of wheat, green manure, etc.). The grass cutting implement 1 is an offset implement that can be offset to the side of the tractor, i.e., to the right, for example.

[0015] As shown in Figures 1 to 4, the mowing machine 1 comprises an attachment section 5 that is detachably connected (attached) to a three-point link section at the rear of the tractor, a working section (mowing working section) 6 that can be changed between a stored state and an offset state and can also be changed between a horizontal position and an inclined position, and that mainly performs mowing work in a desired offset state, and a connecting section (offset mechanism section) 7 that connects the front and rear attachment sections 5 and the working section 6.

[0016] The mowing machine 1 also includes an operating unit (not shown) such as a remote control operated by an operator on the tractor, a drive unit 12 for moving the working unit 6 to change the state and posture of the working unit 6, a first detection unit 13 for detecting the offset amount of the working unit 6 relative to the tractor (the state of the working unit), a second detection unit 14 for detecting the posture angle of the working unit 6 relative to the tractor (the posture of the working unit), and a control unit (control box) 15 for controlling the drive unit 12 based on information (signals) from the first detection unit 13, the second detection unit 14 and the operating unit, etc.

[0017] The drive unit 12 has a first cylinder (offset cylinder) 16, which is an extendable and retractable first drive means for offsetting that moves the working unit 6 left and right relative to the mounting unit 5, and a second cylinder (tilt cylinder) 17, which is an extendable and retractable second drive means for changing posture that rotates the working unit 6 up and down about a rotation center axis (rotation fulcrum) 11 in the front-to-rear direction relative to the connecting unit 7. Each of the cylinders 16, 17 is, for example, an electric hydraulic cylinder. Each of the detectors 13, 14 is, for example, a potentiometer.

[0018] Furthermore, this brush mowing machine 1 is equipped with a power transmission unit 18 that transmits power from the tractor side, and the working unit 6 performs brush mowing work based on the power from this power transmission unit 18. That is, for example, the working body 51 of the working unit 6 performs brush mowing work while rotating in a predetermined direction, the up-cut direction, based on the power from the power transmission unit 18.

[0019] Here, the working unit 6 can perform grass cutting not only in the offset state but also in a stored state where it is stored in the rear of the tractor. The stored state is a state where the working unit 6 is located in a stored position at the rear of the tractor (a position where substantially the entire working unit 6 is stored within the width of the tractor). The offset state is a state where the working unit 6 is located in an offset position that is shifted to the right by a desired offset amount (movement amount) from the stored position at the rear of the tractor.

[0020] The working unit 6 can be moved left and right relative to the tractor (mounting unit) between the storage position and the maximum offset position by extending and retracting the first cylinder 16, and can be positioned at either of these positions or at any position between them.

[0021] Furthermore, at least in the offset state, the working unit 6 can perform grass cutting work in either a horizontal position along the horizontal left-right direction or an upward or downward inclined position (an upward inclined position with the left low and the right high and a downward inclined position with the left high and the right low).

[0022] The working unit 6 can be rotated up and down around the longitudinal pivot axis 11 relative to the tractor (mounting unit) by extending and retracting the second cylinder 17 between the maximum upward tilt position (the highest position where the right end of the working unit is located) and the maximum downward tilt position (the lowest position where the right end of the working unit is located), and can be positioned at either of these positions and any position between them (including a horizontal position corresponding to a horizontal posture).

[0023] In addition, an operator sitting in the driver's seat of the tractor can rotate the working unit 6 up and down around the rotation center axis 11 between the maximum upward tilt position and the maximum downward tilt position (including the horizontal position) by operating the operating unit to extend and retract the second cylinder 17, regardless of whether the tractor is in the stored state or the offset state (see Figure 5).

[0024] The maximum tilt angle α upward with respect to the horizontal direction shown in Fig. 5(a) is, for example, 70°, and the maximum tilt angle β downward with respect to the horizontal direction shown in Fig. 5(b) is, for example, 55° (the same applies to Figs. 11 and 12). These tilt angles α and β are not limited to the angles shown in the figures and may be other angles, or for example, both may be the same angle.

[0025] The mounting unit 5 has a hitch frame 21, which is a mounting frame, and a three-point connecting unit 22 that is detachably connected to a three-point link unit at the rear of the tractor is provided on the hitch frame 21. The three-point connecting unit 22 has a top mast 24 that holds a top pin 23, and a pair of left and right lower arms 26 that hold lower pins 25.

[0026] The hitch frame 21 is also provided with an input shaft holder 29 that rotatably holds an input shaft 28 that receives power from the tractor. The input shaft 28 is connected to a PTO shaft of the tractor (not shown) via a joint, and inputs power from the PTO shaft to the brush cutter 1. Furthermore, an arm attachment portion 30 is provided on the right side of the hitch frame 21.

[0027] The connecting portion 7 has two pivoting arms (parallel links) 41 whose front ends are rotatably attached to the arm mounting portion 30 via axes 46, and the rear ends of each connecting arm 41 are rotatably attached to the arm mounting member 42 via axes 47.

[0028] Furthermore, a rotation central axis (rotation fulcrum) 11 in the front-to-rear direction is fixed to the arm attachment member (fulcrum frame) 42, and this rotation central axis 11 is held by a bearing member 31 of the working unit 6, and this bearing member 31 is rotatable about the rotation central axis 11. In other words, the working unit 6 is rotatable in the up-and-down direction about the round-shaft-shaped rotation central axis (central axis portion) 11 fixed to the arm attachment member (arm attachment portion) 42 of the connecting portion 7.

[0029] The second detector 14 detects the rotation angle of the bearing member 31 relative to the rotation center axis 11 of the connecting part 7, in other words, the vertical rotation angle of the working part 6 relative to the mounting part 5, and transmits this information to the control part 15. The first detector 13 detects the horizontal rotation angle of the connecting arm 41 relative to the mounting part 5, and transmits this information to the control part 15.

[0030] 4, the bearing member 31 is attached to a bearing mount 35 of the working unit 6 by means of attachment means 34, for example, consisting of a bolt 32 and a nut 33. The bearing member 31 has a cylindrical bearing sleeve portion 36, into which the pivot shaft 11 is inserted, and a plate 37 is attached to the rear end of the pivot shaft 11 by a bolt 38, and the plate 37 has a pin 39.

[0031] The pin 39 is inserted into a hole 14b in a lever 14a of a potentiometer, which is the second detection unit 14. A support base 40 that supports the potentiometer, which is the second detection unit 14, is attached to a bearing mount 35 with bolts 20. The bearing mount 35 is fixed to the top surface of a cover body 75 of the working unit 6.

[0032] The arm mounting member 42 also has a cylinder mounting portion 43, and the tip end of the rod 17a of the second cylinder 17 is rotatably mounted to this cylinder mounting portion 43 via a headed pin 44 welded to a plate 66 that is bolted to the cylinder mounting portion 43. The base end of the cylinder body 17b of the second cylinder 17 is rotatably mounted to a cylinder mounting base 48 via a headed pin 45 welded to a plate 67 that is bolted to the cylinder mounting base 48. The cylinder mounting base 48 is bolted to the top surface of a cover body 75 of the working unit 6.

[0033] The rotation center shaft 11, bearing member 31, bearing mount 35, plate 37, support base 40, second detection unit 14, etc. constitute a rotation center portion 19 (the peripheral portion including the rotation center shaft).

[0034] The working unit 6 has a working body (grass-cutting working body) 51, which is a working means that performs grass-cutting work (the work of cutting and shredding grass growing on the work surface) while rotating in a predetermined up-cut direction (the direction of the arrow in the figure) based on power from the power transmission unit 18 that transmits power from the tractor side, a cover means 52 that covers this working body 51, a gauge roller 50 which is a ground contact wheel arranged behind the working body 51, and a scraper 49 that removes deposits (soil, etc.) that have adhered to this gauge roller 50.

[0035] The working unit 6 also has a pulley case 53, which is a first transmission case body that houses multiple pulleys 56, 57, 58, a belt 59, etc., and a gear case (transmission case) 54, which is a second transmission case body that will be described in detail later.

[0036] The belt 59 in the pulley case 53 is wound around a drive pulley 56, a driven pulley 57, and a tension pulley 58, and the tension pulley 58 is biased by a tension spring 60, which serves as a biasing body. The biasing force of the tension spring 60 can be adjusted by a tension bolt 55.

[0037] An intermediate input shaft 61 is rotatably held by the gear case 54, and a power transmission means 62 that transmits power from the input shaft 28 is connected to the intermediate input shaft 61. The power input to the intermediate input shaft 61 from the power transmission means 62 is then transmitted to the working body 51, and as a result, the working body 51 is driven to rotate in a predetermined direction, that is, an up-cut direction, to perform grass cutting work.

[0038] The working body 51 has a rotating shaft 71 that is elongated in the left-right direction, and a plurality of working claws, or grass-cutting claws 74, that are detachably attached to a claw mounting portion 72 of the rotating shaft 71 via mounting members 73 and rotate in an up-cut direction to perform grass-cutting work.

[0039] The cover means 52 has a cover body 75 that is elongated in the left-right direction and is approximately plate-shaped, covering the upper side of the working body 51, and left and right cover side plates 76 that cover the lateral sides of the working body 51, and the rotation shaft 71 of the working body 51 is rotatably supported by these two cover side plates 76.

[0040] Furthermore, a lower side plate 77 is detachably provided at the bottom of each of the left and right cover side plates 76. A pulley case 53 is fixed to the outer surface of the left cover side plate 76. An elastic plate 78 and a cylinder cover member 79 are provided at the front end of the cover body 75.

[0041] On the other hand, the brush cutter 1 is equipped with a confirmation means 81 that allows an operator riding on the tractor to visually confirm the posture of the working unit 6 (the posture angle relative to the horizontal direction perpendicular to the direction of travel) from the tractor side.

[0042] The confirmation means 81 has a cover function that covers the upper side (upper part) of the rotation central axis 11, which is the rotation center of the working unit 6, and is arranged in the vicinity of the rotation central axis 11 so as to cover the upper side of the rotation central axis 11. In other words, the confirmation means 81 is arranged in the vicinity of the rotation central part 19 that includes the rotation central axis 11, and also has a cover function that covers the rotation central part 19.

[0043] Specifically, the confirmation means 81 has a rear cover member 83 which is a first member (rotating member) that rotates around the rotation center axis 11 together with the working unit 6 when the working unit 6 rotates based on the expansion and contraction of the second cylinder 17, and a front cover member 84 which is a second member (non-rotating member) that does not rotate when the working unit 6 rotates based on the expansion and contraction of the second cylinder 17.

[0044] The rear cover member (bearing cover) 83 is attached to the bearing mounting base 35 of the working unit 6 with a screw 85, which is an attachment tool, and the front cover member (fulcrum cover) 84 is attached to the arm mounting member 42 of the connecting unit 7 with a screw 86, which is an attachment tool. These front and rear cover members 83, 84 are arranged close to each other and facing each other, with a small gap 87 between the two cover members 83, 84.

[0045] The front cover member 84 has a cover plate portion 91 that is a substantially arc-shaped plate centered on the rotation central shaft 11, and a concave surface 92 that is recessed downward is formed on the upper surface of this cover plate portion 91. A single reference mark (indicator mark) 93 that can be seen by an operator riding on the tractor is provided in the center of the concave surface 92.

[0046] The reference mark 93 is a sticker (a sheet-like member with an adhesive surface on the back) formed in a triangular shape, such as an isosceles triangle with its apex pointing backward (or an arrow shape, for example). The sticker can be attached to a concave surface using the adhesive surface on the back, so the attachment position can be finely adjusted.

[0047] Furthermore, a plurality of screw holes 95 are formed in the front cover member 84, and screws 86 are threaded through the screw holes 95 into female threaded portions 96 of the arm attachment member 42. The front cover member 84 has a substantially semicircular front plate portion 97, and this front plate portion 97 has cutout portions 98 formed therein for wiring.

[0048] The rear cover member 83 has a cover plate portion 101 that is substantially arc-shaped and centered on the rotation central axis 11, and a substantially semicircular arc-shaped surface (inclined surface) 102 that is centered on the rotation central axis 11 and slopes downward toward the front is formed on the front end side of the upper surface of this cover plate portion 101. The arc-shaped surface 102 is provided with a plurality of marks (indicated marks that are scales for measuring posture angles) 103 to 107 that can be seen by an operator riding on the tractor, for example, 14 marks that are positioned side by side at intervals in the arc direction (longitudinal direction) of the arc-shaped surface 102.

[0049] That is, one marker 103 for the horizontal position, one marker 104 for the maximum upward tilt position, one marker 105 for the maximum downward tilt position, six intermediate markers 106 for the upward tilt position, and five intermediate markers 107 for the downward tilt position are arranged side by side on the arc-shaped surface 102 of the rear cover member 83.

[0050] Here, when the working unit 6 is in a horizontal position, the horizontal posture mark 103 is located at a position corresponding to the reference mark 93, i.e., for example, at a position closely facing the reference mark 93 (a position near the rear of the reference mark) when the working unit 6 is in a horizontal position.

[0051] The mark 104 for the maximum upward tilt posture is located at a position corresponding to the reference mark 93, i.e., for example, at a position closely facing the reference mark 93 (a position near the rear of the reference mark) when the working unit 6 is in the maximum upward tilt posture in which it is positioned at the maximum upward tilt position (highest raised position).

[0052] The mark 105 for the maximum downward tilt posture is located at a position corresponding to the reference mark 93, i.e., for example, at a position closely facing the reference mark 93 (a position near the rear of the reference mark) when the working unit 6 is in the maximum downward tilt posture in which it is positioned at the maximum downward tilt position (lowest position).

[0053] The intermediate marks 106 for the upward tilt position are provided at equal intervals (for example, 10° intervals) on the arc-shaped surface 102 in the portion between the mark 103 for the horizontal position and the mark 104 for the maximum upward tilt position, and are located at a position corresponding to the reference mark 93, i.e., for example, at a position closely facing the reference mark 93 (a position near the rear of the reference mark) when the working unit 6 is in an intermediate upward tilt position at an intermediate position (for example, 10°, 20°, etc.) between the horizontal position and the maximum upward tilt position.

[0054] The intermediate marks 107 for the downward tilt position are provided at equal intervals (for example, 10° intervals) on the arc-shaped surface 102 in the portion between the mark 103 for the horizontal position and the mark 105 for the maximum downward tilt position, and are located at a position corresponding to the reference mark 93, i.e., for example, at a position closely facing the reference mark 93 (a position near the rear of the reference mark) when the working unit 6 is in an intermediate downward tilt position at an intermediate position (for example, 10°, 20°, etc.) between the horizontal position and the maximum downward tilt position.

[0055] Each of the plurality of marks 103 to 107 is made up of a sticker (a sheet-like member having an adhesive surface on the back side) formed in, for example, an elongated, approximately elliptical shape (it may also be, for example, a perfect circle or a rectangle), and each of these stickers can be attached to the arc-shaped surface 102 using the adhesive surface on the back side, so that the attachment position can be finely adjusted. Note that the marks 103 to 107 do not have to be made up of individual stickers, and for example, the marks 103 to 107 may be displayed by printing or the like on the surface of a single strip-shaped sticker (a sheet-like member having an adhesive surface on the back side) that can be attached along the arc-shaped surface 102.

[0056] A plurality of screw holes 109 are formed in the rear cover member 83, and the screws 85 are threaded through the screw holes 109 into the female threads 110 of the bearing mount 35.

[0057] On the other hand, as also shown in Figures 6 to 9, the working section 6 of the brush cutting machine 1 is provided with a gear case 54 which is a box-shaped case body having a connection port 111 on the upper surface and which houses part (for example, gears) of the power transmission section 18 which transmits power (rotational power) from the PTO shaft side of the tractor to the rotating shaft 71 of the working body 51 and in which liquid lubricating oil is stored, and a curved cylindrical tubular body 113 which is connected to the connection port 111 of the gear case 54 and has an exhaust port 112 on the tip side.

[0058] First, the power transmission unit 18 has, for example, the input shaft 28, the power transmission means 62, the intermediate input shaft 61, bevel gears 116 and 117, a transmission shaft 118, a driving pulley 56, a belt 59, and a driven pulley 57, and this driven pulley 57 is attached to the end of the rotating shaft 71 of the working body 51. The bevel gear 117 is provided integrally with the end of the transmission shaft 118.

[0059] Furthermore, the power transmission unit 18 has a one-way clutch 120, which is a clutch means provided between the intermediate input shaft 61 and the bevel gear 116. Therefore, even if the bevel gear 116 rotates due to inertial power from the working body 51 when the driving of the tractor PTO shaft is stopped, the intermediate input shaft 61 does not rotate, and the inertial power from the working body 51 is interrupted midway, thereby preventing damage to the components of the power transmission unit 18 due to overload.

[0060] The one-way clutch 120 is composed of, for example, a clutch pawl 121 and a compression spring 122 that biases the clutch pawl 121, with the clutch pawl 121 being arranged in a clutch pawl groove 123 and the compression spring 122 being arranged in a compression spring groove 124.

[0061] The gear case (transmission case) 54 rotatably holds (supports) the intermediate input shaft 61 via bearings 125 and 126 (see FIG. 9). In FIG. 9, reference numeral 127 denotes a cover member, 128 denotes an O-ring, 129 and 130 denote retaining rings, and 131 denotes a sealing member.

[0062] The gear case 54 rotatably holds (supports) the transmission shaft 118 via bearings 132 and 133 (see FIG. 7). In FIG. 7, reference numeral 134 denotes a seal member, 135 denotes a retaining ring, 136 denotes a nut, 137 denotes a washer, 138 denotes an O-ring, 139 denotes a cork packing, and 140 denotes a closing member.

[0063] The closing member 140 closes an opening 141 formed in the gear case body 150 , and is attached to the gear case body 150 by a plurality of mounting bolts 142 .

[0064] As shown in Figure 10, the closing member 140 has a closing plate portion 143 that closes the opening 141 of the gear case 54, and a prevention plate portion 144 that protrudes from this closing plate portion 143 and is a preventive means for preventing splashes of lubricating oil from the rotating bevel gear 116 from entering the connection port 111.

[0065] A plurality of bolt holes 145, an oil filler port 146, and an oil inspection port 147 are formed in the closure plate portion 143. An oil drain port 148 is formed in the gear case .

[0066] A bolt 151 for the oil filler cap is screwed into the oil filler cap (threaded hole) 146, a bolt 152 for the oil check cap is screwed into the oil dipstick cap (threaded hole) 147, and a bolt 153 for the oil drain cap is screwed into the oil drain cap (threaded hole) 148. In other words, these threaded holes 146, 147, 148 are closed so as to be able to be opened and closed by the bolts 151, 152, 153, which are detachable opening and closing means (plug members) (see FIG. 9).

[0067] The prevention plate portion 144 has a bent plate portion 155 with a generally V-shaped cross section that protrudes from the closure plate portion 143, and a triangular upright plate portion (ear portion) 156 that stands upright at the tip of the bent plate portion 155. The bent plate portion 155 is composed of a vertical first plate 157 and an inclined second plate 158 that is connected to the upper end of the first plate 157, and the upright plate portion 156 is welded and fixed to the upper edge of the second plate 158. The upright plate portion 156 is not limited to being welded and fixed to the bent plate portion 155, but may be formed integrally with the bent plate portion 155 by, for example, bending or the like.

[0068] The guard plate 144 is disposed in the gear case 54 at a position below and adjacent to the connection port 111 so as to prevent splashes of lubricating oil (the straight arrow in FIG. 9 indicates the direction of splashes of lubricating oil) from the rotating bevel gear 116 from entering the connection port 111. In other words, the guard plate 144 is provided between the bevel gear 116 and the connection port 111 in the gear case 54.

[0069] The tubular body 113 is bent, for example, at a right angle at one point in the middle to form an approximately L-shape, and has an exhaust port 112 formed at its tip, and a connecting tube portion 160 at its base end is threadedly connected to the connecting port 111 of the gear case 54.

[0070] The tubular body 113 also has a longitudinal exhaust port communication space 161 that is in communication with the exhaust port 112 at right angles, and a longitudinal communication space 162 that is in communication with the exhaust port communication space 161 at right angles. In other words, the internal space of the tubular body 113 is made up of the exhaust port 112, the exhaust port communication space 161, and the communication space 162. The exhaust port 112 is formed to have a larger diameter than the exhaust port communication space 161 and is formed to be perpendicular to the exhaust port communication space 161.

[0071] Here, as shown in Figure 8, the exhaust port 112 of the tubular body 113 is composed of a threaded hole portion 165 located so as to face a threaded groove 163 formed on the inner surface of the tip of the tubular body 113, and a space portion (pilot hole for tapping) 166 that communicates with this threaded hole portion 165 and is located between a lower end opening 165a of the threaded hole portion 165 and a tip opening 161a of the exhaust port communication space 161.

[0072] The opening diameter (prepared hole diameter) D1 of the space portion 166 of the exhaust port 112 is, for example, 11 mm to 19 mm, and preferably, for example, 15 mm. The opening diameter D2 of the exhaust port communication space 161 is a relatively large dimension that makes it difficult for an oil film to form, for example, 8 mm. Since the opening diameter D1 is larger than the opening diameter D2 (D1>D2), even if an oil film formed in the exhaust port communication space 161 reaches the tip opening 161a as the internal pressure increases, the oil film can be reliably removed, and no oil film will form in the space portion 166 of the exhaust port 112.

[0073] In addition, an exhaust valve cap (exhaust type valve cap) 171 is provided at the tip of the tubular body 113 so as to close the exhaust port 112, and exhausts air when the pressure inside the gear case 54 increases due to a temperature change inside the gear case 54, etc.

[0074] The valved cap 171 is designed so that when the pressure inside the gear case 54 increases and reaches a predetermined pressure, an internal valve 172 opens to exhaust the high-pressure air from the exhaust port 112 to the outside.

[0075] 8, the valved cap 171 has a cylindrical member 173 that is threaded into a thread groove 163 in the tip of the tubular body 113, and a valve 172, a compression spring 174, and an O-ring 175 are provided inside the cylindrical member 173. A lid 176 is also attached to the cylindrical member 173. Furthermore, an O-ring washer 178 is disposed between a flange 177 of the cylindrical member 173 and the upper surface of the tubular body 113.

[0076] When the pressure inside the gear case 54 increases due to a temperature change or the like inside the gear case 54, the pressure inside the tubular body 113 connected to the gear case 54 also increases, and when this pressure reaches a predetermined pressure, the valve 172 opens against the biasing force of the compression spring 174, and as a result, the high-pressure air is discharged outside the tubular body 113.

[0077] Next, the operation of the brush cutting machine 1 will be described.

[0078] When the tractor with the grass cutting implement 1 connected to the rear is driven forward to move the grass cutting implement 1 forward (in the direction of travel), the working body 51 of the working section 6 performs grass cutting work while rotating in a predetermined up-cut direction based on the power from the power transmission section 18, which transmits power from the tractor side.

[0079] During such work, the worker on the tractor sets the tilt angle (posture angle) of the working unit 6 in the offset state relative to the horizontal direction, for example, in accordance with the surface of the work target.

[0080] For example, if the work surface on which grass grows is a horizontal plane, the working unit 6 is set to a horizontal position, or if the work surface is an inclined surface, the working unit 6 is set to an inclined position corresponding to the work surface.

[0081] 11(a) to 11(c), in this brush cutter 1, whether the working unit 6 is in the horizontal position, the maximum upward inclined position, or the maximum downward inclined position, in other words, even if the gear case 54 is tilted in response to a change in the position of the working unit 6, the entire exhaust port 112 of the tubular body 113 is positioned above the oil level S of a predetermined amount of lubricating oil (lubricating oil in a full tank). Therefore, regardless of the position (horizontal position, inclined position) and state (offset state, stored state) of the working unit 6, lubricating oil will not seep into the exhaust port 112 on the tip side of the tubular body 113.

[0082] 11(a), the gear case 54 of the working unit 6 is in a horizontal position, and at this time, the exhaust port 112 is located above the oil level S of a predetermined amount of lubricating oil. Note that the oil level S of the predetermined amount (full amount) of lubricating oil stored in the gear case 54 is located at the lower end of the oil dipstick opening 147 of the gear case 54 when the working unit 6 is in the horizontal position shown in FIG.

[0083] 11(b), the gear case 54 is in the maximum upward tilt position (α=70°) due to the upward rotation of the working unit 6, and at this time, the exhaust port 112 is located above the oil level S of a predetermined amount of lubricating oil (the same applies when 0°<α<70°). At this time, the oil level S in the tubular body 113 is located near the center in the longitudinal direction of the exhaust port communication space 161. Note that the present invention is not limited to the illustrated example, and a configuration may also be used in which, for example, the oil level S in the tubular body 113 is located near the lower end of the exhaust port 112 when the working unit 6 is in the maximum upward tilt position.

[0084] Furthermore, in Figure 11(c), the gear case 54 is in the maximum downward tilt position (β = 55°) due to the downward rotation of the working part 6, and at this time the exhaust port 112 is positioned above the oil level S of the predetermined amount of lubricating oil (the same applies when 0° < β < 55°).

[0085] Furthermore, with such a brush cutting machine 1, the exhaust port 112 of the tubular body 113 connected to the connection port 111 of the gear case 54 is always positioned above the oil level (oil level height position) S of the lubricating oil, regardless of whether the working part 6 is in a horizontal position or an inclined position (including at least the maximum upward inclined position), so that the lubricating oil does not enter the exhaust port 112 of the tubular body 113, and leakage of the lubricating oil can be prevented.

[0086] In addition, a prevention plate portion 144 is provided inside the gear case 54 to prevent splashes of lubricating oil from entering the connection port 111, so that splashes of lubricating oil can be appropriately prevented from entering the tubular body 113.

[0087] Furthermore, the tractor is provided with a confirmation means 81 that allows the operator on the tractor to visually confirm the posture of the working unit 6, and this confirmation means 81 is located in the vicinity of the rotation center axis 11, which is the rotation fulcrum of the working unit 6. Therefore, by using the confirmation means 81, the operator on the tractor can easily and appropriately confirm the posture of the working unit 6 from the tractor side without relying solely on their senses, thereby improving operability, etc.

[0088] In the above embodiment, a configuration has been described in which the connecting tube portion 160 of the curved tubular body 113 is connected to the connecting port 111 of the gear case 54, but this is not limited to this. For example, as shown in Figures 12 and 13, a configuration is also possible in which the connecting tube portion 160 of a straight tubular body 113 (113a) is connected to the connecting port 111 of the gear case 54, and the internal space within the straight tubular body 113 (113a) is composed of an exhaust port 112 and an exhaust port communication space 161.

[0089] Even with this configuration, the exhaust port 112 of the tubular body 113 (113a) is always positioned above the oil level S of the lubricating oil regardless of the posture of the working part 6, so that the lubricating oil does not enter the exhaust port 112, thereby preventing leakage of the lubricating oil.

[0090] Furthermore, the case body of the working unit is not limited to one that houses gears, etc., but may also be one that houses chains, etc., or one that houses belts, etc., and the power transmission components housed within the case body are arbitrary.

[0091] Furthermore, the agricultural work machine is not limited to a grass cutting machine (grass cutter) that cuts grass on the work surface such as the ground or a field, but can also be, for example, a spreader that spreads a substance to be spread on the work surface, a harvester that harvests crops from the work surface, or any other machine such as a rotary or harrow.

[0092] Although several embodiments and modifications of the present invention have been described, it is also possible to combine the embodiments and modifications as appropriate without departing from the gist of the present invention. [Explanation of symbols]

[0093] 1. Grass cutting machine, which is an agricultural machine 6 Working section 18 Power transmission section 54 Gear case, which is the case body 111 Connection port 112 Exhaust port 113 Tubular body 144 Prevention plate part as a prevention means 147 Oil check hole 161 Exhaust port communication space 171 Valve Cap S Lubricating oil level

Claims

1. a power transmission unit that transmits power; a working unit that performs work based on power from the power transmission unit, The working unit includes: a case body that houses at least a portion of the power transmission unit, stores lubricating oil, and has a connection port; a tubular body connected to the connection port of the case body and having an exhaust port at a tip end thereof, The exhaust port is located above the oil surface of the lubricating oil whether the working unit is in a horizontal position or an inclined position. Agricultural machinery characterized by:

2. the tubular body has an exhaust port communication space that communicates with the exhaust port, The exhaust port is formed to have a larger diameter than the exhaust port communication space.

2. The agricultural implement according to claim 1.

3. The exhaust port is formed perpendicular to the exhaust port communication space.

3. The agricultural implement according to claim 2.

4. The tubular body is formed in a bent shape.

4. The agricultural machine according to claim 1, wherein the first and second axes are parallel to each other.

5. The case is provided with a means for preventing lubricating oil splashes from entering the connection port.

4. The agricultural machine according to claim 1, wherein the first and second axes are parallel to each other.

6. The tubular body is provided with a cap with an exhaust valve to close the exhaust port.

4. The agricultural machine according to claim 1, wherein the first and second axes are parallel to each other.

7. The lubricating oil level is at the bottom of the oil inspection port on the case body when the work unit is in a horizontal position.

4. The agricultural machine according to claim 1, wherein the first and second axes are parallel to each other.

8. The working unit can be used for mowing in either a horizontal or inclined position.

4. The agricultural machine according to claim 1, wherein the first and second axes are parallel to each other.

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