Walk-behind cultivator

Abstract

To achieve a configuration capable of avoiding a state where a claw shaft part of a tilling device is rotation driven to a normal rotation direction in a reversed posture and a state where the claw shaft part of the tilling device is rotation driven to a reverse rotation direction in a forward posture, in a walking type control machine.SOLUTION: A walking type control machine includes a normal rotation drive shaft 11 and a reverse rotation drive shaft 12 attached with claw shaft parts 35, 37 of a tilling device. The normal rotation drive shaft 11 is rotation driven to a normal rotation direction, and the reverse rotation drive shaft 12 is rotation driven to a reverse rotation direction. One of the normal rotation drive shaft 11 and the reverse rotation drive shaft 12 is formed in a cylindrical shape, supported by an outer circumferential part of the other of the normal rotation drive shaft 11 and the reverse rotation drive shaft 12, and is rotatable around the same axis as that of the other of the normal rotation drive shaft 11 and the reverse rotation drive shaft 12.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a walk-behind cultivator having a tillage implement attached to its body. [Background technology]

[0002] In the walk-behind cultivator, as disclosed in Patent Document 1, a drive shaft is supported on the machine body along the left-right direction, and the drive shaft is driven to rotate in forward and reverse directions.

[0003] The tillage device has a tine shaft attached to a drive shaft and tillage tines attached to the tine shaft. When the drive shaft is rotated in the forward direction, the tillage tines pass from the upper side to the front of the tine shaft and penetrate the ground, pushing soil from the ground toward the rear. When the drive shaft is rotated in the reverse direction, the tillage tines pass from the upper side to the rear of the tine shaft and penetrate the ground, pushing soil from the ground toward the front.

[0004] The claw shaft portion of the tillage implement is attached to the drive shaft in a forward position and a reverse position. When the tine shaft of the tillage tool is attached to the drive shaft in a forward position, the part of the tillage tool that is radially outward from the tine shaft is located further upstream in the forward rotation direction (see 30 (28) in Figure 1 of Patent Document 1). When the tine shaft of the tillage tool is attached to the drive shaft in a backward position, the part of the tillage tool that is radially outward from the tine shaft is located further downstream in the forward rotation direction. As a result, in a walk-behind cultivator, the normal working conditions are when the claw shaft of the tilling device is attached to the drive shaft in a forward position and the drive shaft is driven to rotate in the forward direction, and when the claw shaft of the tilling device is attached to the drive shaft in a reverse position and the drive shaft is driven to rotate in the reverse direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-10384 Summary of the Invention [Problem to be solved by the invention]

[0006] For example, if the tine shaft of the tillage tool is attached to the drive shaft in an inverted position and the drive shaft is rotated in the forward direction, the tip of the tillage tool will penetrate into the ground before the middle part of the tillage tool, and a large reaction force from the ground may be generated that pushes the tillage tool forward, causing the walk-behind cultivator to be pushed forward.

[0007] As a result, it is necessary to avoid a situation in which the claw shaft of the tilling implement is attached to the drive shaft in an inverted position, causing the drive shaft to be rotated in the forward direction. Similarly, from the viewpoint of ensuring that normal working conditions are carried out properly, it is necessary to avoid a situation in which the claw shaft of the tilling implement is attached to the drive shaft in a forward position, causing the drive shaft to be driven to rotate in the reverse direction.

[0008] The present invention aims to configure a walk-behind cultivator so as to avoid a state in which the claw shaft of the tilling device is rotated in the forward direction in a reverse position, as well as a state in which the claw shaft of the tilling device is rotated in the reverse direction in a forward position. [Means for solving the problem]

[0009] The walk-behind cultivator of the present invention comprises a machine body, a forward rotation drive shaft to which a tine shaft portion of a tillage device having a tine shaft portion and tines attached to the tine shaft portion is attached and which is supported on the machine body along the left-right direction, and a reverse rotation drive shaft to which the tine shaft portion is attached and which is supported on the machine body along the left-right direction, the forward rotation drive shaft is rotationally driven in a forward direction in which the tillage tine passes from the upper side to the front of the tine shaft portion and penetrates into the ground, pushing soil on the ground rearward, and the reverse rotation drive shaft is rotationally driven in a reverse direction in which the tillage tine passes from the upper side to the rear of the tine shaft portion and penetrates into the ground, pushing soil on the ground forward, one of the forward rotation drive shaft and the reverse rotation drive shaft is formed in a cylindrical shape and is supported on the outer periphery of the other of the forward rotation drive shaft and the reverse rotation drive shaft, and is rotatable around the same axis as the other of the forward rotation drive shaft and the reverse rotation drive shaft. The tilling device is detachable from the forward rotation drive shaft and the reverse rotation drive shaft, and can be switched between a state in which the tilling device is connected to the forward rotation drive shaft in a forward orientation and not connected to the reverse rotation drive shaft, and a state in which the tilling device is connected to the reverse rotation drive shaft in a reverse orientation and not connected to the forward rotation drive shaft. do.

[0010] According to the present invention, a forward rotation drive shaft that is driven to rotate in the forward direction and a reverse rotation drive shaft that is driven to rotate in the reverse direction are provided on the machine body, so that the tine shaft of the tilling implement can be attached to the forward rotation drive shaft in a forward position, and the tine shaft of the tilling implement can be attached to the reverse rotation drive shaft in a reverse position, thereby achieving normal operating conditions.

[0011] According to the present invention, one of the forward drive shaft and the reverse drive shaft is formed in a cylindrical shape and is supported on the outer periphery of the other of the forward drive shaft and the reverse drive shaft, and the forward drive shaft and the reverse drive shaft are rotatable about the same axis, so that the forward drive shaft and the reverse drive shaft have different outer diameters.

[0012] The claw shaft of the tilling tool can be easily attached to the forward rotation drive shaft in a forward position, but even if an operator tries to attach the claw shaft of the tilling tool to the forward rotation drive shaft in a reverse position, it is difficult to attach the claw shaft of the tilling tool to the forward rotation drive shaft in a reverse position because the outer diameters of the forward rotation drive shaft and the reverse rotation drive shaft are different. The claw shaft of the tilling tool can be easily attached to the reverse drive shaft in an inverted position, but even if an operator tries to attach the claw shaft of the tilling tool to the reverse drive shaft in a forward position, it is difficult to attach the claw shaft of the tilling tool to the reverse drive shaft in a forward position because the outer diameters of the forward drive shaft and the reverse drive shaft are different.

[0013] When the above-mentioned state occurs, the operator can recognize that he has attempted to attach the claw shaft of the tillage tool to the forward rotation drive shaft in the reverse orientation, and can recognize that he has attempted to attach the claw shaft of the tillage tool to the reverse rotation drive shaft in the forward orientation. This allows the operator to simply attach the claw shaft of the tillage tool to the forward rotation drive shaft in the forward orientation, or to attach the claw shaft of the tillage tool to the reverse rotation drive shaft in the reverse orientation.

[0014] As described above, according to the present invention, by creating a state in which it is difficult to attach the claw shaft of the tillage tool to the forward rotation drive shaft in a reverse position, and by creating a state in which it is difficult to attach the claw shaft of the tillage tool to the reverse rotation drive shaft in a forward position, it becomes possible to avoid a state in which the claw shaft of the tillage tool is rotated in the forward direction in a reverse position, and a state in which the claw shaft of the tillage tool is rotated in the reverse direction in a forward position, thereby improving the operability of the walk-behind cultivator.

[0015] In the present invention, it is preferable that the reverse rotation drive shaft is rotatably supported on the outer periphery of the forward rotation drive shaft, and that the forward rotation drive shaft protrudes outward from an end of the reverse rotation drive shaft.

[0016] In a walk-behind cultivator, the frequency of working states in which the claw shaft of the tilling device is driven to rotate in the forward direction in a forward orientation is higher than the frequency of working states in which the claw shaft of the tilling device is driven to rotate in the reverse direction in a reverse orientation, so the frequency of use of the forward drive shaft is higher than the frequency of use of the reverse drive shaft.

[0017] According to the present invention, the reverse drive shaft is rotatably supported on the outer periphery of the forward drive shaft, and the forward drive shaft protrudes outward from the end of the reverse drive shaft. This makes it easy to attach the claw shaft of the tilling tool to the forward drive shaft in a forward orientation, which is advantageous in terms of improving the operability of the walk-behind cultivator.

[0018] In the present invention, it is preferable that the machine be provided with a prime mover supported on the body, a transmission mechanism that transmits power from the prime mover to the forward rotation drive shaft and drives the forward rotation drive shaft to rotate in the forward direction, and a reverse mechanism that reverses the power branched from the transmission mechanism and transmits it to the reverse rotation drive shaft and drives the reverse rotation drive shaft to rotate in the reverse direction.

[0019] According to the present invention, power from a prime mover is transmitted to the forward rotation drive shaft via the transmission mechanism, and the forward rotation drive shaft is rotated in the forward direction. Power branched from the transmission mechanism is reversed by the reversing mechanism and transmitted to the reverse rotation drive shaft, and the reverse rotation drive shaft is rotated in the reverse direction. This allows the reverse rotation mechanism to be disposed in the vicinity of the reverse rotation drive shaft, making it possible to configure the drive structure of the reverse rotation drive shaft in a compact manner.

[0020] In the present invention, it is preferable that the reversing mechanism has a first transmission gear to which power branched from the transmission mechanism is transmitted and which is driven to rotate in the forward direction, and a second transmission gear attached to the reversing drive shaft and meshing with the first transmission gear.

[0021] According to the present invention, the reversing mechanism has a first transmission gear and a second transmission gear. Power branched from the transmission mechanism is transmitted to the first transmission gear, driving the first transmission gear to rotate in the forward direction. Since the second transmission gear attached to the reversing drive shaft is engaged with the first transmission gear, the power of the first transmission gear is reversed and transmitted to the second transmission gear, driving the reversing drive shaft to rotate in the reverse direction. Thus, by providing the first transmission gear and the second transmission gear in the reversing mechanism, the structure of the reversing mechanism can be simplified.

[0022] In the present invention, it is preferable that the forward rotation drive shaft is supported so as to protrude to the right and left from the machine body, a right reverse drive shaft and a left reverse drive shaft are provided, the right reverse drive shaft is rotatably supported on the outer periphery of the right part of the forward rotation drive shaft, the left reverse drive shaft is rotatably supported on the outer periphery of the left part of the forward rotation drive shaft, the transmission mechanism is provided inside the machine body and is a transmission chain wound around the forward rotation drive shaft, the first transmission gear is disposed inside the winding path of the transmission chain, meshes with the transmission chain, and is rotationally driven in the forward rotation direction by the transmission chain, the right reverse drive shaft is attached to the right reverse drive shaft and is provided with the right second transmission gear meshing with the first transmission gear, and the left reverse drive shaft is attached to the left reverse drive shaft and is provided with the left second transmission gear meshing with the first transmission gear.

[0023] In walk-behind cultivators, the drive shaft is supported so as to protrude to the right and left from the machine body, and the tine shafts of the tilling implement are often attached to the right and left portions of the drive shaft. According to the present invention, the forward drive shaft is supported protruding to the right and left from the rear of the machine body, the right reverse drive shaft is rotatably supported on the outer periphery of the right part of the forward drive shaft, and the left reverse drive shaft is rotatably supported on the outer periphery of the left part of the forward drive shaft.

[0024] According to the present invention, the transmission chain, which is a transmission mechanism, is provided inside the machine body and is wound around the forward rotation drive shaft, and the forward rotation drive shaft is rotated in the forward direction by the transmission chain. In the reversing mechanism, the first transmission gear is disposed inside the winding path of the transmission chain and is engaged with the transmission chain, and is rotated in the forward direction by the transmission chain. The right and left second transmission gears are engaged with the first transmission gear, and the power of the first transmission gear is reversed and transmitted to the right and left second transmission gears, and the right and left reversing drive shafts are rotated in the reverse direction.

[0025] According to the present invention, the first transmission gear is positioned in the reversing mechanism by effectively utilizing the space inside the winding path of the transmission chain, and the right and left second transmission gears can be easily positioned symmetrically with respect to the transmission chain, which is advantageous in terms of simplifying the structure of the reversing mechanism. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. [Figure 2] FIG. 2 is a schematic diagram showing the transmission system inside the transmission case. [Figure 3] FIG. [Figure 4] FIG. 4 is a right side view showing the vicinity of the reversing mechanism. [Figure 5] FIG. 2 is a plan view showing the vicinity of the forward rotation drive shaft, the right and left reverse rotation drive shafts, and the reverse rotation mechanism. [Figure 6] FIG. 2 is a rear view of the claw shaft portion, the cultivator claws, and the rear part of the transmission case of the tillage implement in the forward position. [Figure 7] FIG. 10 is a rear view of the claw shaft portion, the cultivator claws, and the rear part of the transmission case of the tillage implement in the reverse position. DETAILED DESCRIPTION OF THE INVENTION

[0027] A walk-behind cultivator is shown in Figures 1 to 7, and in Figures 1 to 7, F indicates the forward direction, B indicates the backward direction, U indicates the upward direction, D indicates the downward direction, R indicates the right direction, and L indicates the left direction.

[0028] (Overall configuration of the walk-behind cultivator) As shown in Figure 1, right and left running wheels 1 are provided on the bottom of a transmission case 2 (corresponding to the body), and the transmission case 2 is supported by the wheels 1. A support frame 3 is connected to the front of the transmission case 2, and an engine 4 (corresponding to the driving part) is supported by the support frame 3.

[0029] A control handle 5 is connected to the upper part of the transmission case 2 and extends diagonally rearward and upward from the transmission case 2, and a speed change lever 6 extends diagonally rearward and upward from the transmission case 2. A rotary type tiller 7 is provided at the rear of the transmission case 2.

[0030] As shown in Fig. 2, an input shaft 8 is supported in the left-right direction on the upper part of the transmission case 2, and the power of the engine 4 is transmitted to the input shaft 8 via a transmission belt 9. A transmission 10 for traveling is provided inside the transmission case 2, and the power of the input shaft 8 is transmitted to the wheels 1 after being changed in speed by the transmission 10 as described below.

[0031] The forward drive shaft 11 and the reverse drive shaft 12 are supported at the rear of the transmission case 2 along the left-right direction, and the power of the input shaft 8 is transmitted to the forward drive shaft 11 and the reverse drive shaft 12 as described below, thereby driving the tilling device 7.

[0032] (Transmission configuration) As shown in FIG. 2, the transmission 10 is configured to be able to shift between two forward speeds and one reverse speed, as will be explained below, and is operated by a speed change lever 6.

[0033] Transmission shafts 13 , 14 , and 15 are supported inside the transmission case 2 in parallel with the input shaft 8 . A shift gear 16 is supported by a spline structure so as to be rotatable and slidable integrally with the input shaft 8, and a shift gear 17 is supported so as to be rotatable and slidable relative to the transmission shaft 13. Transmission gears 18 and 19 are connected to the transmission shaft 14, and a transmission gear 20 is connected to the transmission shaft 15, with the transmission gears 19 and 20 meshing with each other.

[0034] A differential device 21 is provided at the bottom of the transmission case 2, and a transmission chain 22 is wound around the transmission shaft 15 and the differential device 21. Right and left axles 23 extend to the right and left from the differential device 21, and the wheels 1 are attached to the axles 23.

[0035] A shift fork 24 is provided to slide the shift gear 16. The shift fork 24 operates the shift gear 16 to three positions: a position where it meshes with the transmission gear 18, a position where it meshes with the shift gear 17, and a position where it does not mesh with either the transmission gear 18 or the shift gear 17.

[0036] A shift fork 25 is provided to slide the shift gear 17. The shift fork 25 operates the shift gear 17 to three positions: a position where it meshes with the transmission gear 18, a position where it meshes with the transmission gear 20, and a position where it does not mesh with the transmission gears 18 and 20.

[0037] (Gear change operation of transmission) 2 and 3, a lever guide 26 is attached to the upper part of the transmission case 2, and the speed change lever 6 extends diagonally upward and rearward through the lever guide 26. The speed change lever 6 operates the shift fork 24 and the shift gear 16, and the shift fork 25 and the shift gear 17, as described below.

[0038] 2 and 3 show a state in which the speed change lever 6 is operated to the neutral position N1, the shift gear 16 is operated to a position in which it does not mesh with the transmission gear 18 and the shift gear 17, and the shift gear 17 is operated to a position in which it does not mesh with the transmission gears 18 and 20. In this state, the power of the input shaft 8 is not transmitted to the wheels 1, and the wheels 1 are stopped.

[0039] When the speed change lever 6 is operated from the neutral position N1 to the first forward speed position F1, the shift fork 24 is operated by the speed change lever 6, and the shift gear 16 is operated to a position where it meshes with the transmission gear 18. In this state, the power of the input shaft 8 is transmitted to the wheels 1 in first forward speed via the shift gear 16, the transmission gear 18, the transmission shaft 14, the transmission gears 19 and 20, the transmission shaft 15, and the transmission chain 22.

[0040] When the shift lever 6 is operated from the neutral position N1 to the intermediate position N2, the shift fork 24 is operated by the shift lever 6, and the shift gear 16 is operated to a position where it meshes with the shift gear 17. When the shift lever 6 is operated from the intermediate position N2 to the intermediate position N3, the shift fork 25 can be operated by the shift lever 6, with the shift gear 16 held in a position where it meshes with the shift gear 17.

[0041] When the speed change lever 6 is operated from the intermediate position N3 to the second forward speed position F2, the shift fork 25 is operated by the speed change lever 6, and the shift gear 17 is operated to a position where it meshes with the transmission gear 20 while maintaining a state of meshing with the shift gear 16. In this state, the power of the input shaft 8 is transmitted to the wheels 1 in second forward speed via the shift gears 16 and 17, the transmission gear 20, the transmission shaft 15, and the transmission chain 22.

[0042] When the speed change lever 6 is operated from the intermediate position N3 to the reverse position R1, the shift fork 25 is operated by the speed change lever 6, and the shift gear 17 is operated to a position where it meshes with the transmission gear 18 while maintaining a state of meshing with the shift gear 16. In this state, the power of the input shaft 8 is transmitted to the wheels 1 in a reverse state via the shift gears 16 and 17, the transmission gear 18, the transmission shaft 14, the transmission gears 19 and 20, the transmission shaft 15, and the transmission chain 22.

[0043] (Configuration of forward rotation drive shaft) - 1 As shown in FIG. 2, a transmission gear 28 is rotatably supported on the transmission shaft 13. The transmission gears 29 and 30 are connected to rotate integrally, and the transmission gears 29 and 30 are rotatably supported on the transmission shaft 14, and the transmission gears 28 and 30 are engaged with each other. A working clutch 31 is provided between the transmission shaft 13 and the transmission gear 28.

[0044] 2, 4, and 5, the forward rotation drive shaft 11 is supported so as to protrude rightward and leftward from the rear of the transmission case 2, and a sprocket 41 is connected to the forward rotation drive shaft 11 inside the transmission case 2. A transmission chain 32 (corresponding to a transmission mechanism) is wound around the sprocket 13a connected to the transmission shaft 13 and the sprocket 41 of the forward rotation drive shaft 11.

[0045] A shift gear 33 is supported by a spline structure so as to be rotatable and slidable integrally with the input shaft 8, and a shift fork 34 for slidingly operating the shift gear 33 is provided. The shift gear 33 is operated by the shift fork 34 to two positions: a position where it meshes with the transmission gear 29 and a position where it does not mesh with the transmission gear 29 .

[0046] As shown in Figures 2 and 3, when the shift lever 6 is operated from the neutral position N1 to the first forward gear position F1, and then from the first forward gear position F1 to the stop position N4, the shift fork 34 becomes operable by the shift lever 6 while the shift gear 16 is held in a position where it engages with the transmission gear 18.

[0047] When the shift lever 6 is operated to the forward first gear position F1 and the stop position N4, the shift gear 33 is operated to a position (stop position N4) where it does not engage with the transmission gear 29, and the power of the input shaft 8 is not transmitted to the forward drive shaft 11, causing the forward drive shaft 11 to stop.

[0048] When the speed change lever 6 is moved from the stop position N4 to the normal rotation position S11, the speed change lever 6 operates the shift fork 34, and the shift gear 33 is operated to a position where it meshes with the transmission gear 29.

[0049] In the above-described state, the power of the input shaft 8 is transmitted to the forward rotation drive shaft 11 in the forward rotation state via the shift gear 33, the transmission gears 29 and 30, the transmission gear 28, the work clutch 31, the transmission shaft 13, and the transmission chain 32. In the forward rotation state, the forward rotation drive shaft 11 is driven to rotate in the forward rotation direction S12, which is the clockwise direction in FIG.

[0050] (Configuration of forward rotation drive shaft)-2 With the above configuration, a machine body (transmission case 2) is provided as shown in Fig. 1. A prime mover (engine 4) is provided and supported by the machine body (transmission case 2).

[0051] The tillage device 7 has claw shaft portions 35, 37 and tillage tines 36, 38 attached to the claw shaft portions 35, 37, as described below, attached thereto, and is provided with a forward rotation drive shaft 11 supported along the left-right direction on the machine body (transmission case 2).

[0052] The forward rotation drive shaft 11 is supported so as to protrude to the right and left from the machine body (transmission case 2). A transmission mechanism (transmission chain 32) is provided that transmits power from the prime mover (engine 4) to the forward rotation drive shaft 11 and drives the forward rotation drive shaft 11 to rotate in the forward rotation direction S12. The transmission mechanism is the transmission chain 32 that is provided inside the machine body (transmission case 2) and is wound around the forward rotation drive shaft 11.

[0053] (Configuration of reverse drive shaft) - 1 As shown in FIGS. 2 and 5, a right reverse drive shaft 12 and a left reverse drive shaft 12 are provided.

[0054] The right reverse drive shaft 12 is formed in a cylindrical shape and is rotatably supported on the outer periphery of the right part of the forward drive shaft 11. The left reverse drive shaft 12 is formed in a cylindrical shape and is rotatably supported on the outer periphery of the left part of the forward drive shaft 11. As a result, the right and left reverse drive shafts 12 have a larger diameter than the forward drive shaft 11, and the forward drive shaft 11 and the right and left reverse drive shafts 12 are supported coaxially.

[0055] The right reverse drive shaft 12 and the left reverse drive shaft 12 protrude to the right and left from the rear of the transmission case 2. The right part of the forward drive shaft 11 protrudes outward to the right from the right end of the right reverse drive shaft 12, and the left part of the forward drive shaft 11 protrudes outward to the left from the left end of the left reverse drive shaft 12.

[0056] (Configuration of reverse drive shaft)-2 With the above configuration, as shown in FIGS. 2 and 5, the reverse drive shaft 12 is provided, to which claw shaft portions 35 and 37 (described later) are attached and which is supported in the left-right direction on the machine body (transmission case 2).

[0057] One of the forward drive shaft 11 and the reverse drive shaft 12 is formed in a cylindrical shape and is supported on the outer periphery of the other of the forward drive shaft 11 and the reverse drive shaft 12, and is rotatable around the same axis as the other of the forward drive shaft 11 and the reverse drive shaft 12.

[0058] The reverse rotation drive shaft 12 is rotatably supported on the outer periphery of the forward rotation drive shaft 11 , and the forward rotation drive shaft 11 protrudes outward from the end of the reverse rotation drive shaft 12 . A right reverse drive shaft 12 and a left reverse drive shaft 12 are provided, and the right reverse drive shaft 12 is rotatably supported on the outer periphery of the right part of the forward drive shaft 11, and the left reverse drive shaft 12 is rotatably supported on the outer periphery of the left part of the forward drive shaft 11.

[0059] (Configuration of the reversing mechanism) - 1 As shown in FIGS. 2, 4 and 5, a reversing mechanism 43 is provided inside the rear part of the transmission case 2, and the reversing mechanism 43 has a first transmission gear 44 and a second transmission gear 45.

[0060] The first transmission gear 44 has a right gear portion 44a, a left gear portion 44b, and a sprocket 44c. The sprocket 44c is disposed between the right gear portion 44a and the left gear portion 44b, and the right gear portion 44a, the left gear portion 44b, and the sprocket 44c are connected to one another so as to be rotatable integrally.

[0061] Inside the transmission case 2, the first transmission gear 44 is provided in front of the forward driving shaft 11, is positioned inside the winding path of the transmission chain 32, and is supported rotatably around an axis P1 along the left-right direction.

[0062] The right second transmission gear 45 is connected to the right reverse drive shaft 12, and the left second transmission gear 45 is connected to the left reverse drive shaft 12. The right gear portion 44a of the first transmission gear 44 meshes with the right second transmission gear 45, and the left gear portion 44b of the first transmission gear 44 meshes with the left second transmission gear 45.

[0063] Guide wheels 46, 47 are rotatably supported inside the transmission case 2, and the transmission chain 32 is guided by the upper part of the guide wheel 46, and the transmission chain 32 is guided by the lower part of the guide wheel 47. The portion of the transmission chain 32 between the sprocket 41 of the forward rotation drive shaft 11 and the guide wheel 46 is in mesh with the sprocket 44c of the first transmission gear 44.

[0064] A guide member 48 is fixed inside the transmission case 2. The rear portion of the guide member 48 maintains engagement between the sprocket 44c of the first transmission gear 44 and the transmission chain 32. The portion of the transmission chain 32 between the guide wheels 46, 47 is guided from below by the front portion of the guide member 48.

[0065] When the speed change lever 6 is operated to the forward rotation position S11 and the forward rotation drive shaft 11 is rotated in the forward rotation direction S12 by the transmission chain 32, the first transmission gear 44 meshing with the transmission chain 32 is rotated in the forward rotation direction S12.

[0066] The power transmitted to the first transmission gear 44 is reversed and transmitted to the second transmission gear 45 by the engagement of the right and left gear portions 44a, 44b of the first transmission gear 44 with the right and left second transmission gears 45, and the right reverse drive shaft 12 is driven to rotate in the reverse direction G12, and the left reverse drive shaft 12 is driven to rotate in the reverse direction G12. When the speed change lever 6 is operated to the stop position N4 (the work clutch 31 is operated to the disengaged state) and the forward rotation drive shaft 11 stops, the reverse rotation drive shaft 12 also stops.

[0067] (Configuration of the reversing mechanism)-2 With the above configuration, as shown in Figures 2, 4, and 5, a reverse mechanism 43 is provided which reverses the power branched from the transmission mechanism (transmission chain 32) and transmits it to the reverse drive shaft 12, thereby driving the reverse drive shaft 12 to rotate in the reverse direction G12.

[0068] The reverse mechanism 43 has a first transmission gear 44 to which power branched from the transmission mechanism (transmission chain 32) is transmitted and which is driven to rotate in the forward direction S12, and a second transmission gear 45 attached to the reverse drive shaft 12 and meshing with the first transmission gear 44.

[0069] The first transmission gear 44 is disposed inside the winding path of the transmission chain 32, engages with the transmission chain 32, and is driven to rotate by the transmission chain 32 in the forward direction S12. A right second transmission gear 45 is attached to the right reverse drive shaft 12 and meshes with the first transmission gear 44. A left second transmission gear 45 is attached to the left reverse drive shaft 12 and meshes with the first transmission gear 44.

[0070] (Configuration of tillage equipment) As shown in FIGS. 6 and 7, the tillage implement 7 has a claw shaft portion 35 and a tillage tine 36, a claw shaft portion 37 and a tillage tine 38, and the like.

[0071] The claw shaft portions 35, 37 are configured in the shape of a round pipe, with an attachment hole 35a opening radially in the claw shaft portion 35 and an attachment hole 37a opening radially in the claw shaft portion 37. Two connecting portions 39 are connected to the end of the claw shaft portion 35 opposite the attachment hole 35a, and two connecting portions 40 are connected to the end of the claw shaft portion 37 opposite the attachment hole 37a.

[0072] The tillage tines 36 are attached to the claw shaft 35 in a position facing the end of the claw shaft 35 on the mounting hole 35a side. The tillage tines 38 are attached to the claw shaft 37 in a position facing the end of the claw shaft 37 on the mounting hole 37a side.

[0073] (Installation state of the tine shaft of the tillage device to the forward rotation drive shaft) - 1 5 and 6, right and left mounting holes 11a, 11b are opened radially on the right and left portions of the forward rotation drive shaft 11. The length L11 from the end of the right reverse drive shaft 12 to the right mounting hole 11a of the forward rotation drive shaft 11 is set to be slightly longer than the length L12 from the end of the left reverse drive shaft 12 to the left mounting hole 11b of the forward rotation drive shaft 11.

[0074] Two connecting portions 49 are connected to the right reverse drive shaft 12, and two connecting portions 50 are connected to the left reverse drive shaft 12. As will be described later, the connecting portions 49, 50 are used to connect the claw shafts 35, 37 to the reverse drive shaft 12 by connecting the connecting portions 39, 40 of the claw shafts 35, 37 to the connecting portions 49, 50.

[0075] In the tillage implement 7, the length L21 from the end of the tine shaft 35 to the mounting hole 35a is set to be the same as the length L11. The length L22 from the end of the tine shaft 37 to the mounting hole 37a is set to be the same as the length L12.

[0076] figure 6 As shown in FIG. 1, when an operator inserts the claw shaft portion 35 into the right part of the forward rotation drive shaft 11 from the mounting hole 35a side of the claw shaft portion 35, the right mounting hole 11a of the forward rotation drive shaft 11 and the mounting hole 35a of the claw shaft portion 35 are aligned because the lengths L11 and L21 are the same. This allows the operator to connect the claw shaft portion 35 to the right part of the forward rotation drive shaft 11 by inserting the connecting pin 42 through the mounting hole 35a of the claw shaft portion 35 and the right mounting hole 11a of the forward rotation drive shaft 11.

[0077] When the worker inserts the claw shaft portion 37 into the left part of the forward rotation drive shaft 11 from the mounting hole 37a side of the claw shaft portion 37, the left mounting hole 11b of the forward rotation drive shaft 11 and the mounting hole 37a of the claw shaft portion 37 align because the lengths L12 and L22 are the same. This allows the operator to connect the claw shaft portion 37 to the left part of the forward rotation drive shaft 11 by inserting the connecting pin 42 through the mounting hole 37a of the claw shaft portion 37 and the left mounting hole 11b of the forward rotation drive shaft 11.

[0078] In this case, because the reverse drive shaft 12 has a larger diameter than the forward drive shaft 11 and because there are no connecting portions 39, 40 at the ends of the claw shaft portions 35, 37 on the mounting hole 35a, 37a side, the worker cannot connect the claw shaft portion 35 to the right reverse drive shaft 12, and cannot connect the claw shaft portion 37 to the left reverse drive shaft 12.

[0079] (Installation state of the tine shaft of the tillage equipment on the forward rotation drive shaft) - 2 With the above configuration, in the state shown in Figure 6, the forward rotation drive shaft 11 is driven to rotate in the forward rotation direction S12 so that the tillage tines 36, 38 pass from the upper side to the front side of the tine shaft portions 35, 37, penetrate into the ground, and push the soil on the ground toward the rear (see Figure 1). The tine shafts 35, 37 are in a forward orientation such that the more radially outward the portion of the tillage tines 36, 38 is from the tine shafts 35, 37, the more upstream in the forward rotation direction S12 (see FIG. 1).

[0080] It is assumed that an operator inserts the claw shaft portion 35 into the left part of the normal rotation drive shaft 11 from the mounting hole 35a side of the claw shaft portion 35. It is assumed that an operator inserts the claw shaft portion 37 into the right part of the normal rotation drive shaft 11 from the mounting hole 37a side of the claw shaft portion 37.

[0081] In this state, the orientation of the tillage tines 36, 38 is reversed front to back, so that the tine shafts 35, 37 of the tillage tines 36, 38 assume an inverted position, being positioned downstream in the forward rotation direction S12, as they move radially outward from the tine shafts 35, 37 (a position that is reversed front to back from the position of the tillage tines 36, 38 shown in Figure 1).

[0082] When the above-described situation occurs, the length L12 and the length L21 are different (see Figures 5 and 6), and therefore the left mounting hole 11b of the forward rotation drive shaft 11 and the mounting hole 35a of the claw shaft portion 35 do not match. As a result, the worker cannot insert the connecting pin 42 between the mounting hole 35a of the claw shaft portion 35 and the left mounting hole 11b of the forward rotation drive shaft 11, and therefore cannot connect the claw shaft portion 35 to the left part of the forward rotation drive shaft 11.

[0083] Since the length L11 and the length L22 are different (see FIGS. 5 and 6), the right mounting hole 11a of the forward rotation drive shaft 11 and the mounting hole 37a of the claw shaft portion 37 do not match. As a result, the worker cannot insert the connecting pin 42 between the mounting hole 37a of the claw shaft portion 37 and the right mounting hole 11a of the forward rotation drive shaft 11, and therefore cannot connect the claw shaft portion 37 to the right part of the forward rotation drive shaft 11.

[0084] (Installation state of the claw shaft of the tillage device on the reverse drive shaft) - 1 5 and 7, mounting holes 49a, 50a are formed in the connecting portions 49, 50 of the right and left reverse drive shafts 12. The length L13 from the center of the right reverse drive shaft 12 (forward drive shaft 11) to the mounting hole 49a of the connecting portion 49 is set slightly longer than the length L14 from the center of the left reverse drive shaft 12 (forward drive shaft 11) to the mounting hole 50a of the connecting portion 50.

[0085] 5 and 6, mounting holes 39a, 40a are opened in the connecting portions 39, 40 of the tine shaft portions 35, 37 of the tillage implement 7. A length L23 from the center of the tine shaft portion 35 to the mounting hole 39a of the connecting portion 39 is set to the same length as the length L13. A length L24 from the center of the tine shaft portion 37 to the mounting hole 40a of the connecting portion 40 is set to the same length as the length L14.

[0086] As shown in FIG. 7, when an operator inserts the claw shaft portion 35 into the right part of the forward rotation drive shaft 11 from the connecting portion 39 side of the claw shaft portion 35, the mounting hole 49a of the connecting portion 49 of the right reverse rotation drive shaft 12 and the mounting hole 39a of the connecting portion 39 of the claw shaft portion 35 match because the lengths L13 and L23 are the same (see FIGS. 5 and 6). This allows the operator to connect the claw shaft 35 to the right reverse drive shaft 12 by connecting the bolt 51 between the mounting hole 39a of the connecting portion 39 of the claw shaft 35 and the mounting hole 49a of the connecting portion 49 of the right reverse drive shaft 12.

[0087] When the operator inserts the claw shaft portion 37 into the left part of the forward rotation drive shaft 11 from the connecting portion 40 side of the claw shaft portion 37, the mounting hole 50a of the connecting portion 50 of the left reverse rotation drive shaft 12 and the mounting hole 40a of the connecting portion 40 of the claw shaft portion 37 match because the lengths L14 and L24 are the same (see Figures 5 and 6). This allows the operator to connect the claw shaft 37 to the left reverse drive shaft 12 by connecting the bolt 51 between the mounting hole 40a of the connecting portion 40 of the claw shaft 37 and the mounting hole 50a of the connecting portion 50 of the left reverse drive shaft 12.

[0088] In this case, since the mounting holes 35a, 37a of the claw shaft portions 35, 37 do not match with the right and left mounting holes 11a, 11b of the forward rotation drive shaft 11, the worker cannot connect the claw shaft portion 35 to the right part of the forward rotation drive shaft 11, and cannot connect the claw shaft portion 37 to the left part of the forward rotation drive shaft 11.

[0089] (Installation state of the claw shaft of the tillage device on the reverse drive shaft) - 2 With the above configuration, in the state shown in Figure 7, the reverse drive shaft 12 is driven to rotate in the reverse direction G12 in which the tillage tines 36, 38 pass from the upper side to the rear side of the tine shaft portions 35, 37, penetrate into the ground, and push the soil on the ground forward (see Figure 1). The tine shafts 35, 37 are in an inverted position, with the portion of the tines 36, 38 that is radially outward from the tine shafts 35, 37 positioned upstream in the reverse direction G12 (a position that is reversed from the position of the tines 36, 38 shown in Figure 1).

[0090] Assume that an operator inserts the claw shaft portion 35 into the left part of the normal rotation drive shaft 11 from the connecting portion 39 side of the claw shaft portion 35. Assume that an operator inserts the claw shaft portion 37 into the right part of the normal rotation drive shaft 11 from the connecting portion 40 side of the claw shaft portion 37.

[0091] In this state, the orientation of the tines 36, 38 is reversed front to back, so that the tine shafts 35, 37 are in a forward orientation, with the radially outward portions of the tines 36, 38 positioned downstream in the reverse direction G12 (see Figure 1).

[0092] When the above-described situation occurs, the length L14 and the length L23 are different (see Figures 5 and 6), and therefore the mounting hole 50a of the connecting portion 50 of the left reverse drive shaft 12 and the mounting hole 39a of the connecting portion 39 of the claw shaft portion 35 do not match. As a result, the worker cannot install the bolt 51 between the mounting hole 39a of the connecting portion 39 of the claw shaft portion 35 and the mounting hole 50a of the connecting portion 50 of the left reverse drive shaft 12, and therefore cannot connect the claw shaft portion 35 to the left reverse drive shaft 12.

[0093] Because the lengths L13 and L24 are different (see FIGS. 5 and 6), the mounting hole 49a of the connecting portion 49 of the right reverse drive shaft 12 and the mounting hole 40a of the connecting portion 40 of the claw shaft portion 37 do not match. As a result, the worker cannot install the bolt 51 across the mounting hole 40a of the connecting portion 40 of the claw shaft portion 37 and the mounting hole 49a of the connecting portion 49 of the right reverse drive shaft 12, and therefore cannot connect the claw shaft portion 37 to the right reverse drive shaft 12.

[0094] (First Alternative Embodiment of the Invention) The right and left forward drive shafts 11 may be rotatably supported on the outer periphery of the reverse drive shaft 12, and the reverse drive shaft 12 may be configured to protrude outward from the ends of the right and left forward drive shafts 11.

[0095] According to the above-described configuration, the reverse rotation power is transmitted to the reverse rotation drive shaft 12 by the power transmission chain 32, and the reverse rotation drive shaft 12 is rotated in the reverse direction G12. The power branched from the power transmission chain 32 is reversed by the reversing mechanism 43 and transmitted to the forward rotation drive shaft 11, and the forward rotation drive shaft 11 is rotated in the forward rotation direction S12.

[0096] (Second Alternative Embodiment of the Invention) The reverse rotation mechanism 43 may be eliminated, and a forward / reverse rotation device (not shown) may be provided that outputs the power of the input shaft 8 as forward rotation power and reverse rotation power.

[0097] According to the above-described configuration, the forward rotation power of the forward / reverse rotation device is transmitted to the forward rotation drive shaft 11 via a first transmission mechanism (not shown) so that the forward rotation drive shaft 11 is rotated in the forward rotation direction S12. The reverse rotation power of the forward / reverse rotation device is transmitted to the reverse rotation drive shaft 12 via a second transmission mechanism (not shown) so that the reverse rotation drive shaft 12 is rotated in the reverse direction G12.

[0098] (Third Alternative Embodiment of the Invention) In the configuration shown in Figures 1 to 7, the tilling implement 7 is provided with two tine shaft portions 35, 37, and the tine shaft portions 35, 37 are set to a forward position and a reverse position by switching the positions of the tine shaft portions 35, 37 left and right.

[0099] In the above-described configuration, the tilling implement 7 may be provided with four claw shafts 35, 37, including claw shafts 35, 37 for the forward position and claw shafts 35, 37 for the reverse position. As a result, the claw shafts 35, 37 for the forward position can be attached to the right and left parts of the forward rotation drive shaft 11, and the claw shafts 35, 37 for the reverse position can be attached to the right and left reverse rotation drive shafts 12.

[0100] (Fourth Alternative Embodiment of the Invention) Eight tillage tines 36, 38 may be attached to the tine shaft portions 35, 37, or four tillage tines 36, 38 may be attached to the tine shaft portions 35, 37. Instead of the wheels 1, a crawler traveling device (not shown) may be provided as the traveling device. An electric motor (not shown) may be provided as a driving unit instead of the engine 4. In this case, an electric motor for driving the wheels 1 and an electric motor for driving the tilling implement 7 may be provided separately. The traveling device may be eliminated, and the transmission case 2 may be supported by the tilling device 7 while tilling is performed by the tilling device 7. [Industrial Applicability]

[0101] The present invention can be applied to a walk-behind cultivator in which a tilling implement is attached to the machine body. [Explanation of symbols]

[0102] 2 Transmission case (airframe) 4 Engine (power unit) 7 Tillage equipment 11 Forward drive shaft 12 Reverse drive shaft 32 Transmission chain (transmission mechanism) 35 Claw shaft 36 Cultivating Claw 37 Claw shaft 38 Cultivating Claw 43 Reverse mechanism 44 First transmission gear 45 Second transmission gear S12 Forward direction G12 Reverse direction

Claims

1. The aircraft and A forward rotation drive shaft to which the claw shaft portion of a tillage device having a claw shaft portion and a tillage claw attached to the claw shaft portion is attached and supported along the left-right direction on the machine body; a reverse drive shaft to which the claw shaft portion is attached and which is supported along the left-right direction on the machine body; The forward rotation drive shaft is rotated in a forward rotation direction in which the tillage tines pass from the upper side to the front side of the tine shaft portion, penetrate into the ground, and push out the soil on the ground rearward, The reverse drive shaft is rotated in a reverse direction in which the tillage tines pass from the upper side to the rear side of the tine shaft portion, penetrate into the ground, and push the soil on the ground forward, one of the forward rotation drive shaft and the reverse rotation drive shaft is formed in a cylindrical shape, is supported on an outer periphery of the other of the forward rotation drive shaft and the reverse rotation drive shaft, and is rotatable around a coaxial core with the other of the forward rotation drive shaft and the reverse rotation drive shaft; The tilling device is detachable from the forward drive shaft and the reverse drive shaft, A walk-behind cultivator that can be switched between a state in which the tilling device is connected to the forward rotation drive shaft in a forward orientation and not connected to the reverse rotation drive shaft, and a state in which the tilling device is connected to the reverse rotation drive shaft in a reverse orientation and not connected to the forward rotation drive shaft.

2. the reverse rotation drive shaft is rotatably supported on the outer periphery of the forward rotation drive shaft, 2. The walk-behind cultivator according to claim 1, wherein the forward drive shaft projects outward from the end of the reverse drive shaft.

3. a driving unit supported on the airframe; a transmission mechanism that transmits power from the prime mover to the normal rotation drive shaft and drives the normal rotation drive shaft to rotate in the normal direction; A walking-type tiller as described in claim 1 or 2, which is provided with a reversing mechanism that reverses the power branched from the transmission mechanism and transmits it to the reversing drive shaft, thereby rotating the reversing drive shaft in the reverse direction.

4. The walk-behind cultivator described in claim 3, wherein the reversing mechanism has a first transmission gear to which power branched from the transmission mechanism is transmitted and which is driven to rotate in the forward direction, and a second transmission gear attached to the reversing drive shaft and meshing with the first transmission gear.

5. The forward rotation drive shaft is supported so as to protrude to the right and left from the machine body, a right reverse drive shaft and a left reverse drive shaft are provided, the right reverse drive shaft is rotatably supported on an outer periphery of a right portion of the forward drive shaft, and the left reverse drive shaft is rotatably supported on an outer periphery of a left portion of the forward drive shaft; the transmission mechanism is a transmission chain provided inside the machine body and wound around the forward rotation drive shaft, the first transmission gear is disposed inside a winding path of the transmission chain, engages with the transmission chain, and is rotationally driven in the forward rotation direction by the transmission chain; a right second transmission gear attached to the right reverse drive shaft and meshing with the first transmission gear; 5. The walk-behind cultivator according to claim 4, further comprising a left second transmission gear attached to the left reverse drive shaft and meshing with the first transmission gear.

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