Walk-behind cultivator

Abstract

To avoid generation of dashing in a walking type control machine equipped with a tilling device configured such that a claw shaft part can be changed between a forward posture and a reversed posture.SOLUTION: A walking type control machine includes a transmission device that can be operated to between a normal rotation position at which power of rotation drive of a drive shaft 11 in a normal rotation direction S12 is transmitted to the drive shaft 11, and a stop position at which power to the drive shaft 11 is interrupted. A claw shaft part can be attached to the drive shaft 11 in a forward posture and a reversed posture. The walking type control machine includes restraint parts 45, 46, 50 that prevent generation of a state where the claw shaft part is attached to the drive shaft 11 in the reversed posture and the transmission device is operated to the normal rotation position.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a walk-behind cultivator having a tilling device attached to the rear of a machine body supported by a traveling device. [Background technology]

[0002] As disclosed in Patent Document 1, the tillage implement has a tine shaft attached to the drive shaft of the machine body, and tillage tines attached to the tine shaft. In the tillage implement, the tine shaft (drive shaft) is rotated in a forward direction so that the tines pass from the top to the front of the tine shaft, plunge into the ground, and push the soil on the ground rearward (see R1 in Figure 1 of Patent Document 1).

[0003] The tine shaft is attached to the drive shaft in a forward orientation (see 30 (28) in Figure 1 of Patent Document 1) such that the more radially outward the tine is from the tine shaft, the more upstream in the forward rotation direction it is. As a result, in a walk-behind cultivator, the state in which the tine shaft is attached to the drive shaft in a forward orientation and the tine shaft is driven to rotate in the forward rotation direction is the normal tilling state.

[0004] In some tillage devices, the claw shaft is configured to be attachable to the drive shaft in a reverse position, which is located downstream in the forward rotation direction, as the radially outward portion of the tillage claw from the claw shaft, as opposed to the forward position described above, and the claw shaft is configured to be changeable between the forward position and the reverse position. [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] In a tillage device, when the tine shaft is attached to the drive shaft in an inverted position and driven to rotate in the forward direction, the tip of the tillage tine penetrates into the ground before the middle part of the tillage tine, and a large reaction force from the ground is generated, pushing the tillage device forward strongly. This can cause the walk-behind cultivator to be pushed forward by the force strongly pushing the tillage implement forward (hereinafter referred to as "dashing").

[0007] The present invention aims to provide a configuration that can avoid the occurrence of dashing in a walk-behind cultivator equipped with a tilling device in which the claw shaft portion is configured to be changeable between a forward position and a reverse position. [Means for solving the problem]

[0008] The walk-behind cultivator of the present invention has a body supported by a traveling device, a drive shaft supported in the left-right direction at the rear of the body, a tine shaft portion attached to the drive shaft, and tillage tines attached to the tine shaft portion, and includes a cultivator driven by the drive shaft, a forward rotation position for transmitting power to the drive shaft to rotate the drive shaft in a forward rotation direction in which the tillage tines pass from the upper side to the front side of the tine shaft portion and penetrate into the ground, pushing soil on the ground rearward, and a power to the drive shaft. the claw shaft portion can be attached to the drive shaft in a forward position in which the portion of the tillage tine that is radially outward from the claw shaft portion is positioned upstream in the forward rotation direction, and in a reverse position in which the portion of the tillage tine that is radially outward from the claw shaft portion is positioned downstream in the forward rotation direction, and the claw shaft portion is provided with a restraining portion that prevents the claw shaft portion from being attached to the drive shaft in the reverse position and the transmission device from being operated to the forward rotation position.

[0009] According to the present invention, the situation in which the claw shaft portion is attached to the drive shaft in an inverted position and the claw shaft portion (drive shaft) is driven to rotate in the forward direction can be avoided by the restraining portion, so that dashing can be easily avoided in a walk-behind cultivator equipped with a tilling device in which the claw shaft portion is configured to be changeable between a forward position and an inverted position.

[0010] In the present invention, it is preferable that the restraining unit has an attitude detection unit that detects that the claw shaft portion is attached to the drive shaft in the reverse attitude, and a forward rotation restraining unit that prevents the transmission device from being operated to the forward rotation position when the attitude detection unit detects that the claw shaft portion is attached to the drive shaft in the reverse attitude.

[0011] According to the present invention, when the tine shaft portion is attached to the drive shaft in an inverted orientation in the tillage implement, this is detected by the orientation detection portion. In the above-mentioned state, even if the worker attempts to operate the transmission device to the forward rotation position, the forward rotation restraint section will prevent the transmission device from being operated to the forward rotation position based on the detection by the posture detection section, so the worker can recognize that the claw shaft section is attached to the drive shaft in an inverted position. This allows the operator to simply attach the tine shaft portion to the drive shaft in the tillage implement in a forward position, and then operate the transmission device to the forward rotation position.

[0012] In the present invention, the tillage implement has a first claw shaft portion attached to one of the right and left portions of the drive shaft, and a second claw shaft portion attached to the other of the right and left portions of the drive shaft, and is provided with a right attitude detection portion that detects that the claw shaft portion is attached to the right portion of the drive shaft in the reverse attitude, and a left attitude detection portion that detects that the claw shaft portion is attached to the left portion of the drive shaft in the reverse attitude, and it is preferable that the forward rotation restraint portion prevents operation of the transmission device to the forward rotation position when the right attitude detection portion detects that the claw shaft portion is attached to the right portion of the drive shaft in the reverse attitude, or when the left attitude detection portion detects that the claw shaft portion is attached to the left portion of the drive shaft in the reverse attitude.

[0013] Some tillage implements have a first claw shaft portion attached to one of the right and left portions of the drive shaft, and a second claw shaft portion attached to the other of the right and left portions of the drive shaft. According to the present invention, a right attitude detection unit and a left attitude detection unit are provided, and when either the first claw drive shaft or the second claw drive shaft is attached to the drive shaft in an inverted attitude, the forward rotation restraint unit functions, which is advantageous in terms of avoiding dashing of the walking cultivator.

[0014] In the present invention, the first claw shaft portion and the second claw shaft portion can be attached to the drive shaft in an inward position in which the tillage tines face toward the left-right central portion of the tillage device when viewed from behind, and in an outward position in which the tillage tines face outward from the left-right central portion of the tillage device when viewed from behind, and it is preferable that the position detection unit detects when the claw shaft portion is attached to the drive shaft in the inverted position and the inward position, and detects when the claw shaft portion is attached to the drive shaft in the inverted position and the outward position.

[0015] In a tillage implement, when a first claw shaft portion and a second claw shaft portion are provided, the tillage implement may be configured so that the first claw shaft portion can be attached to the right part of the drive shaft and the second claw shaft portion can be attached to the left part of the drive shaft, or conversely, the first claw shaft portion can be attached to the left part of the drive shaft and the second claw shaft portion can be attached to the right part of the drive shaft. This allows the claw shaft portion to be attached to the drive shaft in an inward orientation, and the claw shaft portion to be attached to the drive shaft in an outward orientation.

[0016] According to the present invention, even if the claw shaft portion is attached to the drive shaft in an inverted or inward orientation, or even if the claw shaft portion is attached to the drive shaft in an inverted or outward orientation, this can be detected by the orientation detection portion. This allows the forward rotation restraint section to function whether the claw shaft section is attached to the drive shaft in an inverted or inward position, or whether the claw shaft section is attached to the drive shaft in an inverted or outward position, which is advantageous in terms of avoiding dashing in a walk-behind cultivator.

[0017] In the present invention, it is preferable that the restraining portion has a forward rotation detection portion that detects that the transmission device has been operated to the forward rotation position, and a claw shaft restraining portion that prevents the claw shaft portion from being attached to the drive shaft in the reverse orientation when the forward rotation detection portion detects that the transmission device has been operated to the forward rotation position.

[0018] According to the present invention, when the transmission device is operated to the forward rotation position, this is detected by the forward rotation detection unit. In the above-mentioned state, even if the worker attempts to attach the claw shaft portion to the drive shaft in the reverse position, the claw shaft restraining section will prevent the claw shaft portion from being attached to the drive shaft in the reverse position based on the detection of the forward rotation detection section, so the worker can recognize that he or she is attempting to attach the claw shaft portion to the drive shaft in the reverse position. This allows the operator to simply attach the pawl shaft portion to the drive shaft in a normal orientation.

[0019] In the present invention, the tillage device has a first claw shaft portion attached to one of the right and left portions of the drive shaft, and a second claw shaft portion attached to the other of the right and left portions of the drive shaft, and it is preferable that the claw shaft restraining portion prevents the claw shaft portion from being attached to the right portion of the drive shaft in the reverse position when the forward rotation detection portion detects that the transmission device has been operated to the forward rotation position, and prevents the claw shaft portion from being attached to the left portion of the drive shaft in the reverse position.

[0020] Some tillage implements have a first claw shaft portion attached to one of the right and left portions of the drive shaft, and a second claw shaft portion attached to the other of the right and left portions of the drive shaft. According to the present invention, when the transmission device is operated to the forward rotation position and this is detected by the forward rotation detection unit, even if an operator attempts to attach the claw shank in the reverse position to the right portion of the drive shaft, the claw shank restraining unit prevents the claw shank from being attached to the right portion of the drive shaft in the reverse position.Similarly, even if an operator attempts to attach the claw shank in the reverse position to the left portion of the drive shaft, the claw shank restraining unit prevents the claw shank from being attached to the left portion of the drive shaft in the reverse position.

[0021] This allows the worker to recognize that he or she is attempting to attach the claw shaft portion to the drive shaft in an inverted position at an early stage when he or she attempts to attach the claw shaft portion to one of the right and left parts of the drive shaft in an inverted position.

[0022] In the present invention, it is preferable that the restraining unit includes an attitude detection unit that detects that the claw shaft portion is attached to the drive shaft in the reverse attitude, a forward rotation detection unit that detects that the transmission device has been operated to the forward rotation position, a forward rotation restraining unit that prevents operation of the transmission device to the forward rotation position when the attitude detection unit detects that the claw shaft portion is attached to the drive shaft in the reverse attitude, and a claw shaft restraining unit that prevents attachment of the claw shaft portion to the drive shaft in the reverse attitude when the forward rotation detection unit detects that the transmission device has been operated to the forward rotation position.

[0023] According to the present invention, when the tine shaft portion is attached to the drive shaft in an inverted orientation in the tillage implement, this is detected by the orientation detection portion. In the above-mentioned state, even if the worker attempts to operate the transmission device to the forward rotation position, the forward rotation restraint section will prevent the transmission device from being operated to the forward rotation position based on the detection by the posture detection section, so the worker can recognize that the claw shaft section is attached to the drive shaft in an inverted position. This allows the operator to simply attach the tine shaft portion to the drive shaft in the tillage implement in a forward position, and then operate the transmission device to the forward rotation position.

[0024] According to the present invention, when the transmission device is operated to the forward rotation position, this is detected by the forward rotation detection unit. In the above-mentioned state, even if the worker attempts to attach the claw shaft portion to the drive shaft in the reverse position, the claw shaft restraining section will prevent the claw shaft portion from being attached to the drive shaft in the reverse position based on the detection of the forward rotation detection section, so the worker can recognize that he or she is attempting to attach the claw shaft portion to the drive shaft in the reverse position. This allows the operator to simply attach the pawl shaft portion to the drive shaft in a normal orientation.

[0025] As described above, according to the present invention, it is possible to avoid a situation in which the claw shaft portion is attached to the drive shaft in an inverted position, causing the claw shaft portion (drive shaft) to be driven to rotate in the forward direction, which is advantageous in terms of avoiding dashing in walk-behind cultivators.

[0026] In the present invention, there is provided a claw shaft blocking member operable to an attachment blocking position that blocks attachment of the claw shaft portion to the drive shaft and an attachment allowing position that allows attachment of the claw shaft portion to the drive shaft; an operating unit that is provided on the claw shaft and that, when the claw shaft portion is attached to the drive shaft in the reverse orientation, comes into contact with the claw shaft blocking member and thereby operates the claw shaft blocking member to the attachment allowing position; a forward rotation blocking member operable to a forward rotation blocking position that blocks operation of the transmission device to the forward rotation position and to a forward rotation allowing position that allows operation of the transmission device to the forward rotation position and that prevents operation to the forward rotation blocking position when the transmission device is operated to the forward rotation position; and a connecting member connected across the forward rotation blocking member and the claw shaft blocking member. and a linking member, and when the claw shaft portion is attached to the drive shaft in the reverse orientation, the claw shaft blocking member is operated to the attachment allowable position by the operating portion, and the forward rotation blocking member is operated to the forward rotation blocking position via the linking member, when the forward rotation blocking member is operated to the forward rotation allowable position, the claw shaft blocking member is operated to the attachment blocking position via the linking member, and when the transmission device is operated to the forward rotation position, the claw shaft blocking member is held at the attachment blocking position via the forward rotation blocking member and the linking member, and it is preferable that the claw shaft blocking member is the orientation detection portion and the claw shaft restraining portion, and the forward rotation blocking member is the forward rotation detection portion and the forward rotation restraining portion.

[0027] According to the present invention, a forward rotation preventing member and a pawl shaft preventing member are provided, and the forward rotation preventing member and the pawl shaft preventing member are connected via a linking member. When the pawl shaft preventing member is operated to the attachment allowing position, the forward rotation preventing member is operated to the forward rotation preventing position via the linking member, and when the forward rotation preventing member is operated to the forward rotation allowing position, the pawl shaft preventing member is operated to the attachment preventing position via the linking member.

[0028] According to the present invention, when the pawl shaft portion is attached to the drive shaft in a reverse orientation without the transmission device being operated to the forward rotation position, the operating portion of the pawl shaft portion comes into contact with the pawl shaft blocking member, and the operating portion of the pawl shaft portion operates the pawl shaft blocking member to the attachment allowance position. When the pawl shaft blocking member is operated to the attachment allowance position, this operation is transmitted to the forward rotation blocking member via the linkage member, and the forward rotation blocking member is operated to the forward prevention position. As a result, even if an operator attempts to operate the transmission device to the forward rotation position, the operator cannot operate the transmission device to the forward rotation position because the forward rotation preventing member has been operated to the forward rotation preventing position.

[0029] According to the present invention, when the transmission device is operated to the forward rotation position while the claw shaft portion is not attached to the drive shaft in an inverted position (when the claw shaft blocking member is operated to the attachment blocking position), the forward rotation blocking member cannot move to the forward rotation blocking position and is held in the forward rotation allowing position, so that the claw shaft blocking member is held in the attachment blocking position via the forward rotation blocking member and the linking member. As a result, even if an operator attempts to attach the claw shaft portion to the drive shaft in an inverted position, the operating part of the claw shaft portion will come into contact with the claw shaft blocking member held in the attachment blocking position, making it impossible to attach the claw shaft portion to the drive shaft in an inverted position.

[0030] As described above, according to the present invention, when a forward rotation preventing member and a claw shaft blocking member are provided, the forward rotation preventing member and the claw shaft blocking member are mechanically connected via a linking member, which is a simple configuration that prevents the claw shaft portion from being attached to the drive shaft in an inverted position and the claw shaft portion (drive shaft) from being driven to rotate in the forward direction, thereby simplifying the structure.

[0031] According to the present invention, the claw shaft blocking member has the function of an attitude detection section that detects when the claw shaft portion is attached to the drive shaft in an inverted attitude, and the function of a claw shaft restraining section that prevents the claw shaft portion from being attached to the drive shaft in an inverted attitude, so that the structure can be simplified by combining the functions.

[0032] According to the present invention, the forward rotation preventing member has the function of a forward rotation detection section that detects when the transmission device has been operated to the forward rotation position, and the function of a forward rotation restraint section that prevents the transmission device from being operated to the forward rotation position.By combining these functions, the structure can be simplified.

[0033] In the present invention, it is preferable that the operating portion is provided around the entire circumferential direction of the claw shaft portion, and that the operating portion comes into contact with the claw shaft blocking member regardless of the phase in the rotational direction of the drive shaft when the claw shaft portion is attached in the reverse posture.

[0034] In a tillage implement, when the drive shaft is stopped and then the tine shaft portion is attached to the drive shaft, it is not known at what rotational phase the drive shaft will stop, and therefore it is not known at what phase in the rotational direction of the drive shaft the tine shaft portion will be attached to the drive shaft.

[0035] According to the present invention, the operating portion is provided around the entire circumference of the claw shaft portion, and the operating portion comes into contact with the claw shaft blocking member regardless of the phase in the rotational direction of the drive shaft when the claw shaft portion is attached in an inverted position. This allows the claw shaft blocking member to function as a posture detection unit and a claw shaft restraint unit, regardless of whether the claw shaft is attached (or attempted to be attached) in an inverted position and in any phase of the rotation direction of the drive shaft, which is advantageous in terms of avoiding dashing in walk-behind cultivators.

[0036] In the present invention, the tillage implement has a first claw shaft portion attached to one of the right and left portions of the drive shaft, and a second claw shaft portion attached to the other of the right and left portions of the drive shaft, and is provided with a right claw shaft blocking member that can be operated to the mounting blocking position that prevents the claw shaft portion from being mounted to the right portion of the drive shaft and the mounting allowing position that allows the claw shaft portion to be mounted to the right portion of the drive shaft, and a left claw shaft blocking member that can be operated to the mounting blocking position that prevents the claw shaft portion from being mounted to the left portion of the drive shaft and the mounting allowing position that allows the claw shaft portion to be mounted to the left portion of the drive shaft, and it is preferable that the forward rotation blocking member be operated to the forward rotation blocking position via the linkage member by at least one of the right claw shaft blocking member being operated to the mounting allowing position and the left claw shaft blocking member being operated to the mounting allowing position.

[0037] Some tillage implements have a first claw shaft portion attached to one of the right and left portions of the drive shaft, and a second claw shaft portion attached to the other of the right and left portions of the drive shaft. According to the present invention, a right claw shaft blocking member and a left claw shaft blocking member are provided, and when either the first claw drive shaft or the second claw drive shaft is attached to the drive shaft in an inverted position, the forward rotation blocking member functions as a forward rotation restraint part, which is advantageous in terms of avoiding dashing of the walk-behind tiller.

[0038] In the present invention, when the transmission device is operated to the forward rotation position, it is preferable that the right claw shaft blocking member and the left claw shaft blocking member are held in the mounting blocking position via the forward rotation blocking member and the connecting member.

[0039] According to the present invention, when the transmission device is operated to the forward rotation position and the forward rotation preventing member is held in the forward rotation allowing position, the right claw shaft preventing member and the left claw shaft preventing member are held in the mounting preventing position via the forward rotation preventing member and the connecting member. Even if an operator attempts to attach the claw shank to the right side of the drive shaft in the reverse position, the right claw shank blocking member will prevent the claw shank from being attached to the right side of the drive shaft in the reverse position.Similarly, even if an operator attempts to attach the claw shank to the left side of the drive shaft in the reverse position, the left claw shank blocking member will prevent the claw shank from being attached to the left side of the drive shaft in the reverse position. This allows the worker to recognize that he or she is attempting to attach the claw shaft portion to the drive shaft in an inverted position at an early stage when he or she attempts to attach the claw shaft portion to one of the right and left parts of the drive shaft in an inverted position.

[0040] In the present invention, the tillage implement has a first claw shaft portion attached to one of the right and left portions of the drive shaft, and a second claw shaft portion attached to the other of the right and left portions of the drive shaft, and the first claw shaft portion and the second claw shaft portion can be attached to the drive shaft in an inward position in which the tillage tines face toward the left-right center of the tillage implement in a rear view, and an outward position in which the tillage tines face outward from the left-right center of the tillage implement in a rear view, and the operating unit is configured such that when the claw shaft portion is attached to the drive shaft in the inverted position and the inward position, it abuts against the claw shaft blocking member, thereby operating the claw shaft blocking member to the attachment allowable position, and when the claw shaft portion is attached to the drive shaft in the inverted position and the outward position, it abuts against the claw shaft blocking member, thereby operating the claw shaft blocking member to the attachment allowable position, and and an avoidance portion is provided in the claw shaft blocking member, which prevents the operating portion from hitting the claw shaft blocking member when the claw shaft portion is attached to the drive shaft in the forward orientation and the inward orientation, and which prevents the operating portion from hitting the claw shaft blocking member when the claw shaft portion is attached to the drive shaft in the forward orientation and the outward orientation, and when the claw shaft portion is attached to the drive shaft in the reverse orientation and the inward orientation, the claw shaft blocking member is operated to the attachment allowable position by the operating portion, and the forward rotation preventing member is operated to the forward rotation preventing position via the linking member, and when the claw shaft portion is attached to the drive shaft in the reverse orientation and the outward orientation, the claw shaft blocking member is operated to the attachment allowable position by the operating portion, and the forward rotation preventing member is operated to the forward rotation preventing position via the linking member.

[0041] According to the present invention, when the transmission device is not operated to the forward rotation position and the claw shaft portion is attached to the drive shaft in a reverse and inward position (when the claw shaft portion is attached to the drive shaft in a reverse and outward position), the claw shaft blocking member is operated to the attachment allowing position and the forward rotation blocking member is operated to the forward rotation blocking position, so the operator cannot operate the transmission device to the forward rotation position.

[0042] According to the present invention, when the transmission device is operated to the forward rotation position and the forward rotation preventing member is held in the forward rotation allowing position, even if an operator attempts to attach the claw shaft portion to the drive shaft in the reverse orientation and inward orientation (reverse orientation and outward orientation), the operator cannot attach the claw shaft portion to the drive shaft in the reverse orientation and inward orientation (reverse orientation and outward orientation).

[0043] This prevents the claw shaft from being attached to the drive shaft in an inverted and inward position (inverted and outward position), causing the claw shaft (drive shaft) to be driven to rotate in the forward direction, which is advantageous in terms of preventing dashing of the walk-behind tiller.

[0044] In a tillage device, when a first claw shaft portion and a second claw shaft portion are provided, the claw shaft portions can be attached to the drive shaft in a reverse position and an inward position (reverse position and outward position), and the claw shaft portions can also be attached to the drive shaft in a forward position and an inward position (forward position and outward position).

[0045] According to the present invention, even if the claw shaft portion is attached to the drive shaft in a forward position and an inward position (forward position and outward position), the avoidance portion prevents the operating portion from hitting the claw shaft blocking member, and the claw shaft blocking member is not operated to the attachment-permitting position, so the forward rotation blocking member is not operated to the forward rotation blocking position. This allows the transmission device to be operated to the normal rotation position without any hindrance when the claw shaft portion is attached to the drive shaft in a forward position and an inward position (forward position and outward position), so there is no reduction in the workability of the walk-behind cultivator.

[0046] According to the present invention, even if the transmission device is operated to the forward rotation position and the claw shaft blocking member is held in the mounting blocking position, when the claw shaft portion is mounted on the drive shaft in the forward orientation and inward orientation (forward orientation and outward orientation), the avoidance portion prevents the operating portion from hitting the claw shaft blocking member. This allows the claw shaft portion to be attached to the drive shaft without any problems in the forward position and inward position (forward position and outward position), so that the workability of the walk-behind cultivator is not reduced.

[0047] In the present invention, it is preferable that the operating portion is provided around the entire circumferential circumference of the claw shaft portion, and comes into contact with the claw shaft blocking member no matter in what phase of the rotational direction of the drive shaft the claw shaft portion is attached to the drive shaft in the reverse orientation or the inward orientation, or in what phase of the rotational direction of the drive shaft the claw shaft portion is attached to the drive shaft in the reverse orientation or the outward orientation, and that the avoidance portion is provided around the entire circumferential circumference of the operating portion, and prevents the operating portion from coming into contact with the claw shaft blocking member no matter in what phase of the rotational direction of the drive shaft the claw shaft portion is attached to the drive shaft in the forward orientation or the inward orientation, or in what phase of the rotational direction of the drive shaft the claw shaft portion is attached to the drive shaft in the forward orientation or the outward orientation.

[0048] In a tillage implement, when the drive shaft is stopped and then the tine shaft portion is attached to the drive shaft, it is not known at what rotational phase the drive shaft will stop, and therefore it is not known at what phase in the rotational direction of the drive shaft the tine shaft portion will be attached to the drive shaft.

[0049] According to the present invention, the operating portion is provided around the entire circumference of the claw shaft portion, and the operating portion comes into contact with the claw shaft blocking member regardless of the phase in the rotational direction of the drive shaft in which the claw shaft portion is attached (or is about to be attached) in the reverse position and inward position (reverse position and outward position). This allows the claw shaft blocking member to function as a position detection unit and a claw shaft restraint unit, regardless of whether the claw shaft is attached (or is about to be attached) in an inverted or inward position (inverted or outward position) or in any phase of the rotation direction of the drive shaft, which is advantageous in terms of avoiding dashing in walk-behind cultivators.

[0050] According to the present invention, an avoidance portion is provided around the entire circumferential circumference of the operating portion, and the avoidance portion prevents the operating portion from hitting the claw shaft blocking member, regardless of whether the claw shaft portion is attached (or is about to be attached) in a reverse or inward position (reverse or outward position) or at any phase in the rotational direction of the drive shaft. This allows the claw shaft portion to be attached to the drive shaft without any problems in the forward position and inward position (forward position and outward position), so that the workability of the walk-behind cultivator is not reduced. [Brief explanation of the drawings]

[0051] [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. 2 is a rear view of the tine shaft portion and the tillage tine in the tillage implement. [Figure 5] FIG. 4 is a left side view showing the inside of the transmission case. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. 10 is a rear view of the vicinity of the claw shaft blocking member and the drive shaft. [Figure 9] FIG. 2 is a plan view of the vicinity of the claw shaft blocking member and the drive shaft. [Figure 10] 10 is a schematic diagram showing a state in which the pawl shaft portion is attached to the drive shaft in a reverse orientation and an inward orientation, and the shift lever cannot be operated to the normal rotation position. FIG. [Figure 11] 10 is a schematic diagram showing a state in which the pawl shaft portion is attached to the drive shaft in a reverse orientation and an outward orientation, and the shift lever cannot be operated to the normal rotation position. FIG. [Figure 12] 10 is a schematic diagram showing a state in which the speed change lever is operated to a normal rotation position and the pawl shaft portion cannot be attached to the drive shaft in a reverse orientation or an inward orientation. FIG. [Figure 13] 10 is a schematic diagram showing a state in which the speed change lever is operated to a normal rotation position and the pawl shaft portion cannot be attached to the drive shaft in a reverse orientation or an outward orientation. FIG. [Figure 14] 10 is a schematic diagram showing a state in which the pawl shaft portion is attached to the drive shaft in a forward orientation and an inward orientation, and the shift lever can be operated to a forward rotation position. FIG. [Figure 15]10 is a schematic diagram showing a state in which the pawl shaft portion is attached to the drive shaft in a forward position and an outward position, and the shift lever can be operated to a forward rotation position. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0052] A walk-behind cultivator is shown in Figures 1 to 15, and in Figures 1 to 15, 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.

[0053] (Overall configuration of the walk-behind cultivator) As shown in Figure 1, right and left running wheels 1 (corresponding to running devices) are provided on the bottom of a transmission case 2 (corresponding to the vehicle 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 is supported by the support frame 3.

[0054] 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.

[0055] 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.

[0056] A drive shaft 11 is supported in the left-right direction at the rear of the transmission case 2. A forward / reverse rotation device 12 (corresponding to a transmission device) is provided inside the transmission case 2, and the power of the input shaft 8, as well as forward rotation power and reverse rotation power from the forward / reverse rotation device 12, as described below, are transmitted to the drive shaft 11, driving the drive shaft 11 to rotate, and the tiller 7 is driven by the drive shaft 11.

[0057] With the above configuration, the vehicle is provided with a body (transmission case 2) supported by a traveling device (wheels 1) as shown in Figure 1. A drive shaft 11 is provided at the rear of the body (transmission case 2) and supported along the left-right direction.

[0058] (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.

[0059] Transmission shafts 13, 14, and 15 are supported inside transmission case 2 in parallel with input shaft 8. Shift gear 16 is supported by a spline structure so as to be rotatable and slidable integrally with input shaft 8, and shift gear 17 is supported so as to be rotatable and slidable relative to transmission shaft 13. Transmission gears 18 and 19 are connected to transmission shaft 14, and transmission gear 20 is connected to transmission shaft 15, with transmission gear 19 and transmission gear 20 meshing with each other.

[0060] A differential device 21 is provided at the bottom of the transmission case 2, and a transmission chain 22 is attached between 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.

[0061] 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.

[0062] 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.

[0063] (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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] (Configuration and operation of forward / reverse rotation device) As shown in FIG. 2, the forward / reverse rotation device 12 is configured as described below to transmit forward rotation power and reverse rotation power to the drive shaft 11, and is operated by the speed change lever 6.

[0070] Transmission gears 27 and 28 are connected to rotate integrally, and transmission gears 27 and 28 are rotatably supported on transmission shaft 13. Transmission gears 29 and 30 are connected to rotate integrally, and transmission gears 29 and 30 are rotatably supported on transmission shaft 14, and transmission gears 28 and 30 are in mesh with each other. A working clutch 31 is provided between the transmission shaft 13 and the transmission gears 27, 28, and a transmission chain 32 is attached between the transmission shaft 13 and the drive shaft 11.

[0071] 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 is provided to slide the shift gear 33. The shift fork 34 operates the shift gear 33 to three positions: a position in mesh with the transmission gear 27, a position in mesh with the transmission gear 29, and a position in which the shift gear 33 does not mesh with the transmission gears 27 and 29.

[0072] 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.

[0073] 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 gears 27, 29, and the power of the input shaft 8 is not transmitted to the drive shaft 11, causing the drive shaft 11 to stop.

[0074] When the speed change lever 6 is operated from the stop position N4 to the forward rotation position S11, the shift fork 34 is operated by the speed change lever 6, and the shift gear 33 is operated to a position where it meshes with the transmission gear 29. In this state, the power of the input shaft 8 is transmitted in the forward rotation state to the drive shaft 11 via the shift gear 33, the transmission gears 29, 30, the transmission gears 27, 28, the working clutch 31, the transmission shaft 13, and the transmission chain 32. In the forward rotation state, the drive shaft 11 is driven to rotate in the forward rotation direction S12, which is the clockwise direction in FIG. 1.

[0075] When the speed change lever 6 is operated from the stop position N4 to the reverse position G11, the shift fork 34 is operated by the speed change lever 6, and the shift gear 33 is operated to a position where it meshes with the transmission gear 27. In this state, the power of the input shaft 8 is transmitted in a reverse state to the drive shaft 11 via the shift gear 33, the transmission gears 27, 28, the working clutch 31, the transmission shaft 13, and the transmission chain 32. In the reverse state, the drive shaft 11 is driven to rotate in the reverse direction G12, which is the counterclockwise direction in FIG. 1.

[0076] (Configuration of tillage equipment) As shown in FIGS. 1 and 4, the tillage implement 7 has a first tine shaft portion 35, a first tillage tine 36, a second tine shaft portion 37, a second tillage tine 38, and the like.

[0077] The claw shaft portions 35, 37 are configured in the shape of a round pipe, with two mounting holes 35a, 35b opening radially in the claw shaft portion 35, and two mounting holes 37a, 37b opening radially in the claw shaft portion 37.

[0078] A large-diameter disk-shaped operating portion 40 and a cover 39 are connected to one end of the claw shaft portions 35, 37, and a small-diameter disk-shaped operating portion 41 and a cover 39 are connected to the other end of the claw shaft portions 35, 37.

[0079] At the claw shaft portion 35, the tillage claw 36 is attached to the claw shaft portion 35 in an orientation facing the operation unit 40. At the claw shaft portion 37, the tillage claw 38 is attached to the claw shaft portion 37 in an orientation facing the operation unit 41.

[0080] In the drive shaft 11, mounting holes 11a, 11b are opened along the radial direction on the right and left parts of the drive shaft 11. The claw shaft portions 35, 37 are inserted into the right and left parts of the drive shaft 11, and the connecting pin 42 is inserted through the mounting holes 35a, 35b, 37a, 37b of the claw shaft portions 35, 37 and the mounting holes 11a, 11b of the drive shaft 11, thereby connecting the claw shaft portions 35, 37 to the drive shaft 11.

[0081] 1 and 4, the above configuration provides a tillage device 7 that has claw shafts 35, 37 attached to the drive shaft 11 and tillage tines 36, 38 attached to the claw shafts 35, 37, and is driven by the drive shaft 11. The tillage device 7 has a first claw shaft 35 attached to one of the right and left portions of the drive shaft 11, and a second claw shaft 37 attached to the other of the right and left portions of the drive shaft 11.

[0082] As shown in Figures 1 and 2, the tillage tines 36, 38 pass from the top to the front of the tine shafts 35, 37 and penetrate into the ground, pushing the soil on the ground backward. A transmission device (forward / reverse rotation device 12) is provided that can be operated to a forward rotation position S11 where the power is transmitted to the drive shaft 11 to rotate the drive shaft 11 in a forward rotation direction S12, and a stop position N4 where the power to the drive shaft 11 is cut off.

[0083] (Installation on the drive shaft of the tillage equipment) - 1 In the tillage implement 7, the claw shaft portions 35, 37 can be attached to the drive shaft 11 in one of four mounting positions, as described below: reverse and inward, reverse and outward, forward and inward, and forward and outward.

[0084] As shown in Figures 4 and 10, the claw shaft portion 35 is inserted into the right part of the drive shaft 11 from the side of the operating portion 40, the claw shaft portion 37 is inserted into the left part of the drive shaft 11 from the side of the operating portion 41, and the connecting pin 42 is inserted through the mounting holes 35a, 37a of the claw shaft portions 35, 37 and the mounting holes 11a, 11b of the drive shaft 11, thereby connecting the claw shaft portions 35, 37 to the drive shaft 11.

[0085] In the state shown in FIG. 10, the claw shaft portions 35, 37 are attached to the drive shaft 11 in the reverse orientation and the inward orientation. The reverse orientation is an orientation in which the radially outward portions of the tillage tines 36, 38 from the tine shafts 35, 37 are positioned downstream in the forward rotation direction S12. The inward orientation is an orientation in which the tillage tines 36, 38 face toward the left-right center side (the transmission case 2 side) of the tillage implement 7 when viewed from the rear (front).

[0086] As shown in Figures 4 and 11, the claw shaft portion 35 is inserted into the left part of the drive shaft 11 from the side of the operating portion 41, the claw shaft portion 37 is inserted into the right part of the drive shaft 11 from the side of the operating portion 40, and the connecting pin 42 is inserted through the mounting holes 35b, 37b of the claw shaft portions 35, 37 and the mounting holes 11a, 11b of the drive shaft 11, thereby connecting the claw shaft portions 35, 37 to the drive shaft 11.

[0087] In the state shown in FIG. 11, the claw shaft portions 35 and 37 are attached to the drive shaft 11 in an inverted position and an outward position. The outward orientation is an orientation in which the tillage tines 36, 38 face outward relative to the left-right center of the tillage implement 7 (transmission case 2) when viewed from the rear (front).

[0088] As shown in Figures 4 and 14, the claw shaft portion 35 is inserted into the left part of the drive shaft 11 from the side of the operating portion 40, the claw shaft portion 37 is inserted into the right part of the drive shaft 11 from the side of the operating portion 41, and the connecting pin 42 is inserted through the mounting holes 35a, 37a of the claw shaft portions 35, 37 and the mounting holes 11a, 11b of the drive shaft 11, thereby connecting the claw shaft portions 35, 37 to the drive shaft 11.

[0089] In the state shown in FIG. 14, the claw shaft portions 35 and 37 are attached to the drive shaft 11 in a forward orientation and an inward orientation. The forward orientation is an orientation in which the portions of the tillage tines 36, 38 that are radially outward from the tine shafts 35, 37 are positioned upstream in the forward rotation direction S12.

[0090] As shown in Figures 4 and 15, the claw shaft portion 35 is inserted into the right part of the drive shaft 11 from the side of the operating portion 41, the claw shaft portion 37 is inserted into the left part of the drive shaft 11 from the side of the operating portion 40, and the connecting pin 42 is inserted through the mounting holes 35b, 37b of the claw shaft portions 35, 37 and the mounting holes 11a, 11b of the drive shaft 11, thereby connecting the claw shaft portions 35, 37 to the drive shaft 11. In the state shown in FIG. 15, the claw shaft portions 35 and 37 are attached to the drive shaft 11 in a forward orientation and an outward orientation.

[0091] (Installation on the drive shaft of the tillage equipment) - 2 With the above configuration, as shown in Figures 10, 11, 14, and 15, in the tillage device 7, the tine shaft portions 35, 37 can be attached to the drive shaft 11 in a forward position in which the portion of the tillage tines 36, 38 that is radially outward from the tine shaft portions 35, 37 is located upstream of the forward rotation direction S12, and in a reverse position in which the portion of the tillage tines 36, 38 that is radially outward from the tine shaft portions 35, 37 is located downstream of the forward rotation direction S12.

[0092] The first claw shaft portion 35 and the second claw shaft portion 37 can be attached to the drive shaft 11 in an inward position where the tillage tines 36, 38 face toward the center of the left and right sides of the tillage device 7 when viewed from behind, and in an outward position where the tillage tines 36, 38 face outward from the center of the left and right sides of the tillage device 7 when viewed from behind.

[0093] (Configuration of claw shaft blocking member) As shown in Figures 5, 8, and 9, a fulcrum shaft 43 is provided at the rear of the transmission case 2, above the drive shaft 11, and a channel-shaped operating member 44 is supported on the fulcrum shaft 43 so as to be swingable around an axis P1 along the fulcrum shaft 43.

[0094] The right claw shaft blocking member 45 (corresponding to the restraining part, posture detection part, and claw shaft restraining part) is supported on the right part of the rear of the transmission case 2 so as to be slidable in the left-right direction, and the right claw shaft blocking member 45 is connected to the operating member 44.

[0095] An operating member 47 is supported on the fulcrum shaft 43 so as to be swingable about an axis P1. A left pawl shaft blocking member 46 (corresponding to the restraining portion, the attitude detecting portion, and the pawl shaft restraining portion) is supported on the left portion of the rear of the transmission case 2 so as to be slidable in the left-right direction. A connecting pin 48 is attached across the operating members 44, 47 and the left pawl shaft blocking member 46.

[0096] The state shown in Figures 8 and 9 is a state in which the right and left claw shaft blocking members 45, 46 are positioned at an installation blocking position A11 protruding outward from the transmission case 2, and the right and left claw shaft blocking members 45, 46 can be moved to an installation allowable position A12 recessed inside the transmission case 2.

[0097] The right and left claw shaft blocking members 45, 46 are connected by operating members 44, 47 and a connecting pin 48. As a result, when one of the right and left claw shaft blocking members 45, 46 is operated to the mounting blocking position A11, the other of the right and left claw shaft blocking members 45, 46 is operated to the mounting blocking position A11 via the operating members 44, 47 and the connecting pin 48.

[0098] Similarly, when one of the right and left claw shaft blocking members 45, 46 is operated to the installation allowable position A12, the other of the right and left claw shaft blocking members 45, 46 is operated to the installation allowable position A12 via the operating members 44, 47 and the connecting pin 48.

[0099] (Relationship between the claw shaft blocking member and the operating part of the claw shaft) As shown in Figures 8 and 9, the right and left claw shaft blocking members 45, 46 are provided so that the length L1 from the axis P3 of the drive shaft 11 to the right claw shaft blocking member 45 is longer than the length L2 from the axis P3 of the drive shaft 11 to the left claw shaft blocking member 46.

[0100] As shown in FIG. 4, the operating portions 40 and 41 are disk-shaped and are provided around the entire circumference of the claw shaft portions 35 and 37. As shown in Figure 8, in the disk-shaped operating parts 40, 41, the radius RR1 of the operating part 40 (the length from the axis P3 of the drive shaft 11 to the end of the outer periphery of the operating part 40) is set to be larger than the lengths L1, L2.

[0101] In the operating part 40, a recess 40a (corresponding to an avoidance part) facing the left-right center of the claw shaft parts 35, 37 is provided around the entire circumference of the operating part 40 at a length L2 from the center of the claw shaft parts 35, 37. The recess 40a is ring-shaped and is formed around the entire circumference of the operating part 40 in the circumferential direction.

[0102] 8, the radius RR2 of the operating part 41 (the length from the axis P3 of the drive shaft 11 to the end of the outer periphery of the operating part 41) is set to be smaller than the length L1 and larger than the length L2. As a result, the outer periphery of the operating part 41 serves as an avoidance part, and the outer periphery of the operating part 41 (avoidance part) is formed around the entire circumferential circumference of the operating part 41.

[0103] When the claw shaft portions 35, 37 are inserted into the right part of the drive shaft 11 from the operating part 40 side, the outer periphery of the operating part 40 comes into contact with the right claw shaft blocking member 45, and the right claw shaft blocking member 45 is moved from the mounting blocking position A11 to the mounting allowable position A12.

[0104] When the claw shaft portions 35, 37 are inserted into the right part of the drive shaft 11 from the operating part 41 side, the outer periphery of the operating part 41 enters below the right claw shaft blocking member 45, so that the right claw shaft blocking member 45 cannot be operated to the installation allowable position A12.

[0105] When the claw shaft portions 35, 37 are inserted into the left part of the drive shaft 11 from the operating part 40 side, the left claw shaft blocking member 46 enters the recess 40a of the operating part 40, so the left claw shaft blocking member 46 is not operated to the installation allowable position A12.

[0106] When the claw shaft portions 35, 37 are inserted into the left part of the drive shaft 11 from the operating part 41 side, the outer periphery of the operating part 41 comes into contact with the left claw shaft blocking member 46, and the left claw shaft blocking member 46 is operated from the mounting blocking position A11 to the mounting allowable position A12.

[0107] (Configuration of operation of the gear shift lever to the forward and reverse positions) As shown in Figures 5, 6, and 7, the shift shaft 49 is provided in the upper front part of the transmission case 2, above the input shaft 8, along the left-right direction, and the shift fork 34 (see Figure 2) is supported on the shift shaft 49 so as to be slidable along the left-right direction.

[0108] An engagement portion 34a extends upward from the shift fork 34. When the speed change lever 6 is operated from the first forward speed position F1 to the stop position N4 (see FIG. 3), the lower part of the speed change lever 6 engages with the engagement portion 34a of the shift fork 34.

[0109] When the shift lever 6 is operated from the stop position N4 to the forward rotation position S11 (see Figure 3), the shift fork 34 is slid to the left in Figure 7 by the shift lever 6, and the shift gear 33 is operated to a position where it engages with the transmission gear 29 (see Figure 2).

[0110] When the shift lever 6 is moved from the stop position N4 to the reverse position G11 (see Figure 3), the shift fork 34 is slid to the right in Figure 7 by the shift lever 6, and the shift gear 33 is moved to a position where it engages with the transmission gear 27 (see Figure 2).

[0111] (Configuration of forward rotation prevention member) As shown in Figures 5, 6 and 7, a shaft-shaped forward rotation preventing member 50 (corresponding to the restraining portion, forward rotation detecting portion and forward rotation restraining portion) is provided in the upper front portion of the transmission case 2, above the engaging portion 34a of the shift fork 34, along the left-right direction, and is supported rotatably around an axis P2 along the left-right direction.

[0112] An arm 50a is connected to the right end of the forward rotation preventing member 50, and an arm 50b is connected to the left end of the forward rotation preventing member 50. The state shown in Figures 6 and 7 is a state in which the forward rotation preventing member 50 is operated to a forward rotation allowing position B12 in which the arm 50a of the forward rotation preventing member 50 is positioned above the engaging portion 34a of the shift fork 34 in a side view.

[0113] With the speed change lever 6 (shift fork 34) operated to the stop position N4 or the reverse position G11, the forward rotation preventing member 50 can be rotated slightly clockwise in Figure 6 to operate the forward rotation preventing member 50 to a forward rotation preventing position B11 where the arm 50a of the forward rotation preventing member 50 overlaps with the engagement portion 34a of the shift fork 34 in a side view. A spring 51 is attached to the forward rotation preventing member 50, and the spring 51 biases the forward rotation preventing member 50 to the forward rotation allowing position B12.

[0114] With the forward rotation preventing member 50 operated to the forward rotation allowing position B12, the speed change lever 6 (shift fork 34) can be operated to the forward rotation position S11 (see FIG. 3). When the forward rotation preventing member 50 is operated to the forward rotation allowing position B12 and the speed change lever 6 (shift fork 34) is operated to the forward rotation position S11 (operated to the left in Figure 7), the engagement portion 34a of the shift fork 34 enters below the arm 50a of the forward rotation preventing member 50 at the forward rotation allowing position B12.

[0115] In the above-described state, even if the forward rotation preventing member 50 is attempted to be moved from the forward rotation allowing position B12 to the forward rotation preventing position B11, the arm 50a of the forward rotation preventing member 50 abuts against the engaging portion 34a of the shift fork 34. As a result, the forward rotation preventing member 50 cannot be moved from the forward rotation allowing position B12 to the forward rotation preventing position B11, and is held at the forward rotation allowing position B12.

[0116] When the speed change lever 6 (shift fork 34) is operated to the stop position N4 or the reverse position G11 and the forward rotation preventing member 50 is operated to the forward rotation preventing position B11, even if the speed change lever 6 (shift fork 34) is attempted to be operated to the forward rotation position S11, the engaging portion 34a of the shift fork 34 will come into contact with the arm 50a of the forward rotation preventing member 50.

[0117] As a result, the forward rotation preventing member 50 cannot be moved from the forward rotation allowing position B12 to the forward rotation preventing position B11, and the speed change lever 6 (shift fork 34) cannot be moved from the stop position N4 to the forward rotation position S11.

[0118] (Configuration of the linking member connected across the forward rotation preventing member and the claw shaft preventing member)-1 As shown in FIGS. 5 to 9, a rod-shaped linking member 52 is connected within the transmission case 2 between the arm 50b of the forward rotation preventing member 50 and the operating member 47 of the claw shaft preventing members 45, .

[0119] The state shown in Figures 6 to 9 is a state in which the forward rotation preventing member 50 is operated by the spring 51 to the forward rotation allowing position B12, the forward rotation preventing member 50 pulls the connecting member 52 forward (towards the forward rotation preventing member 50), and the claw shaft preventing members 45, 46 are operated to the mounting preventing position A11.

[0120] As described below, when the claw shaft portions 35, 37 are attached to the drive shaft 11 in an inverted and inward position (inverted and outward position), the operating portions 40, 41 of the claw shaft portions 35, 37 operate the claw shaft blocking members 45, 46 from the attachment blocking position A11 to the attachment allowable position A12.

[0121] When the claw shaft blocking members 45, 46 are operated from the mounting blocking position A11 to the mounting allowable position A12, the claw shaft blocking members 45, 46 detect that the claw shaft portions 35, 37 have been mounted on the drive shaft 11 in an inverted and inward position (inverted and outward position).

[0122] In the state shown in Figures 6 to 9, when the claw shaft blocking members 45, 46 are operated from the mounting blocking position A11 to the mounting allowable position A12, the linking member 52 is pulled rearward (toward the claw shaft blocking members 45, 46), and the forward rotation blocking member 50 is operated from the forward rotation allowable position B12 to the forward rotation blocking position B11.

[0123] In the state shown in Figures 6 to 9, when the speed change lever 6 (shift fork 34) is operated to the forward rotation position S11, the engagement portion 34a of the shift fork 34 enters below the arm 50a of the forward rotation preventing member 50 in the forward rotation allowing position B12, and the forward rotation preventing member 50 cannot be operated to the forward rotation preventing position B11 (the forward rotation preventing member 50 is held in the forward rotation allowing position B12).

[0124] Since the forward rotation preventing member 50 cannot be operated from the forward rotation allowing position B12 to the forward rotation preventing position B11, the forward rotation preventing member 50 detects that the speed change lever 6 (shift fork 34) has been operated to the forward rotation position S11 and that the forward / reverse rotation device 12 has been operated to the forward rotation position S11.

[0125] When the forward rotation preventing member 50 is held in the forward rotation allowing position B12, the pawl shaft preventing members 45, 46 are held via the linking member 52 in the mounting preventing position A11. When the claw shaft blocking members 45, 46 are held in the mounting blocking position A11, as described below, the claw shaft blocking members 45, 46 prevent the claw shaft portions 35, 37 from being mounted on the drive shaft 11 in the reverse and inward positions (reverse and outward positions).

[0126] (Configuration of the linking member connected across the forward rotation preventing member and the claw shaft preventing member)-2 With the above configuration, as shown in Figures 5 to 9, the claw shaft portions 35, 37 are attached to the drive shaft 11 in an inverted position, and a restraining portion (claw shaft blocking members 45, 46 and forward rotation blocking member 50) is provided to prevent the transmission device (forward / reverse rotation device 12) from being operated to the forward rotation position S11.

[0127] The restraining section (claw shaft blocking members 45, 46 and forward rotation blocking member 50) has an attitude detecting section (claw shaft blocking members 45, 46) that detects that the claw shafts 35, 37 are attached to the drive shaft 11 in an inverted attitude, and a forward rotation restraining section (forward rotation blocking member 50) that prevents the transmission device (forward / reverse rotation device 12) from being operated to the forward rotation position S11 when the attitude detecting section (claw shaft blocking members 45, 46) detects that the claw shafts 35, 37 are attached to the drive shaft 11 in an inverted attitude.

[0128] The device is provided with a right posture detection unit (right claw shaft blocking member 45) that detects when the claw shaft portions 35, 37 are attached to the right part of the drive shaft 11 in an inverted posture, and a left posture detection unit (left claw shaft blocking member 46) that detects when the claw shaft portions 35, 37 are attached to the left part of the drive shaft 11 in an inverted posture.

[0129] The restraining portion (claw shaft blocking members 45, 46 and forward rotation blocking member 50) has a forward rotation detection portion (forward rotation blocking member 50) that detects that the transmission device (forward / reverse rotation device 12) has been operated to the forward rotation position S11, and a claw shaft restraining portion (claw shaft blocking members 45, 46) that prevents the claw shaft portions 35, 37 from being attached to the drive shaft 11 in a reverse position when the forward rotation detection portion (forward rotation blocking member 50) detects that the transmission device (forward / reverse rotation device 12) has been operated to the forward rotation position S11.

[0130] When the forward rotation detection unit (forward rotation prevention member 50) detects that the transmission device (forward / reverse rotation device 12) has been operated to the forward rotation position S11, the claw shaft restraining unit (claw shaft blocking members 45, 46) prevents the claw shaft portions 35, 37 from being attached to the right side of the drive shaft 11 in the reverse position, and also prevents the claw shaft portions 35, 37 from being attached to the left side of the drive shaft 11 in the reverse position.

[0131] The restraining unit (claw shaft blocking members 45, 46 and forward rotation blocking member 50) includes a posture detection unit (claw shaft blocking members 45, 46) that detects that the claw shafts 35, 37 are attached to the drive shaft 11 in a reverse posture, a forward rotation detection unit (forward rotation blocking member 50) that detects that the transmission device (forward / reverse rotation device 12) is operated to the forward rotation position S11, and a posture detection unit (claw shaft blocking members 45, 46) that detects that the claw shafts 35, 37 are attached to the drive shaft 11 in a reverse posture. The device has a forward rotation restraining section (forward rotation preventing member 50) that prevents the transmission device (forward / reverse rotation device 12) from being operated to the forward rotation position S11 when it is detected that it has been installed, and a claw shaft restraining section (claw shaft preventing members 45, 46) that prevents the claw shaft sections 35, 37 from being installed in a reverse position on the drive shaft 11 when the forward rotation detecting section (forward rotation preventing member 50) detects that the transmission device (forward / reverse rotation device 12) has been operated to the forward rotation position S11.

[0132] (Configuration of the linking member connected across the forward rotation preventing member and the claw shaft preventing member)-3 With the above configuration, as shown in Figures 5 to 9, claw shaft blocking members 45, 46 are provided which can be operated to an attachment blocking position A11 that prevents attachment of the claw shaft portions 35, 37 to the drive shaft 11, and an attachment allowing position A12 that allows attachment of the claw shaft portions 35, 37 to the drive shaft 11.

[0133] A forward rotation preventing member 50 is provided which can be operated to a forward rotation preventing position B11 which prevents operation of the transmission device (forward / reverse rotation device 12) to the forward rotation position S11, and a forward rotation allowing position B12 which allows operation of the transmission device (forward / reverse rotation device 12) to the forward rotation position S11 and prevents operation to the forward rotation preventing position B11 when the transmission device (forward / reverse rotation device 12) is operated to the forward rotation position S11.

[0134] The claw shaft portions 35, 37 are provided with operating portions 40, 41 that come into contact with the claw shaft blocking members 45, 46 when the claw shaft portions 35, 37 are attached to the drive shaft 11 in an inverted position, thereby operating the claw shaft blocking members 45, 46 to the attachment allowable position A12.

[0135] A linking member 52 is provided that connects the normal rotation preventing member 50 and the pawl shaft preventing members 45, 46 across the linking member 52. When the claw shaft portions 35, 37 are attached to the drive shaft 11 in an inverted position, the claw shaft blocking members 45, 46 are operated to the attachment allowance position A12 by the operating portions 40, 41, and the forward rotation blocking member 50 is operated to the forward rotation blocking position B11 via the linking member 52.

[0136] When the forward rotation preventing member 50 is operated to the forward rotation allowing position B12, the claw shaft preventing members 45, 46 are operated to the mounting preventing position A11 via the linking member 52, and when the transmission device (forward / reverse rotation device 12) is operated to the forward rotation position S11, the claw shaft preventing members 45, 46 are held at the mounting preventing position A11 via the forward rotation preventing member 50 and the linking member 52. The claw shaft blocking members 45 and 46 are posture detection units and claw shaft restraining units, and the normal rotation blocking member 50 is a normal rotation detection unit and a normal rotation restraining unit.

[0137] (In the tillage equipment, the state after the tines are attached to the drive shaft in the reverse and inward positions, and the reverse and outward positions) - 1 As shown in Figures 4, 8 and 10, when the claw shaft portions 35, 37 are attached to the drive shaft 11 in the reverse orientation and the inward orientation, when the claw shaft portion 35 is inserted into the right part of the drive shaft 11 from the operating portion 40 side, the operating portion 40 of the claw shaft portion 35 abuts against the right claw shaft blocking member 45, and the right claw shaft blocking member 45 is operated to the installation allowable position A12. In conjunction with this, the left claw shaft blocking member 46 is operated to the installation allowable position A12.

[0138] When the claw shaft portions 35, 37 are attached to the drive shaft 11 in an inverted and inward orientation, when the claw shaft portion 37 is inserted into the left part of the drive shaft 11 from the operating portion 41 side, the operating portion 41 of the claw shaft portion 37 comes into contact with the left claw shaft blocking member 46, and the left claw shaft blocking member 46 is operated to the installation allowable position A12, and in conjunction with this, the right claw shaft blocking member 45 is operated to the installation allowable position A12.

[0139] As shown in Figures 4, 8, and 11, when the claw shaft portions 35, 37 are attached to the drive shaft 11 in the inverted and outward orientations, when the claw shaft portion 35 is inserted into the left portion of the drive shaft 11 from the operating portion 41 side, the operating portion 41 of the claw shaft portion 35 abuts against the left claw shaft blocking member 46, and the left claw shaft blocking member 46 is operated to the installation allowable position A12. In conjunction with this, the right claw shaft blocking member 45 is operated to the installation allowable position A12.

[0140] When the claw shaft portions 35, 37 are attached to the drive shaft 11 in an inverted position and an outward position, when the claw shaft portion 37 is inserted into the right part of the drive shaft 11 from the operating portion 40 side, the operating portion 40 of the claw shaft portion 37 comes into contact with the right claw shaft blocking member 45, and the right claw shaft blocking member 45 is operated to the installation allowable position A12, and in conjunction with this, the left claw shaft blocking member 46 is operated to the installation allowable position A12.

[0141] Since the operating parts 40, 41 are formed in a disk shape, the operating parts 40, 41 come into contact with the claw shaft blocking members 45, 46 no matter at what phase in the rotation direction of the drive shaft 11 the claw shaft parts 35, 37 are attached in the reverse or inward position, or at what phase in the rotation direction of the drive shaft 11 the claw shaft parts 35, 37 are attached to the drive shaft 11 in the reverse or outward position.

[0142] As described above, when the claw shaft blocking members 45, 46 are operated to the installation allowable position A12, the forward rotation blocking member 50 is operated to the forward rotation blocking position B11 via the linkage member 52, so that the speed change lever 6 (shift fork 34) cannot be operated to the forward rotation position S11 and the forward / reverse rotation device 12 cannot be operated to the forward rotation position S11. In this case, it is possible to operate the speed change lever 6 (shift fork 34) to the reverse position G11, and the forward / reverse rotation device 12 to the reverse position G11.

[0143] (In the tillage equipment, the state after the tines are attached to the drive shaft in the reverse and inward positions, and the reverse and outward positions) - 2 With the above-described configuration, as shown in FIGS. 4 and 8, the operating portions 40, 41 are provided around the entire circumferential direction of the claw shaft portions 35, 37, and come into contact with the claw shaft blocking members 45, 46 regardless of the phase in the rotational direction of the drive shaft 11 when the claw shaft portions 35, 37 are attached in an inverted position.

[0144] As shown in Figures 10 and 11, when the claw shaft portions 35, 37 are attached to the drive shaft 11 in an inverted or inward position, the operating portions 40, 41 come into contact with the claw shaft blocking members 45, 46, thereby operating the claw shaft blocking members 45, 46 to the allowable attachment position A12, and when the claw shaft portions 35, 37 are attached to the drive shaft 11 in an inverted or outward position, the operating portions 40, 41 come into contact with the claw shaft blocking members 45, 46, thereby operating the claw shaft blocking members 45, 46 to the allowable attachment position A12.

[0145] The operating parts 40, 41 are provided around the entire circumference of the claw shaft parts 35, 37, and come into contact with the claw shaft blocking members 45, 46 no matter at what phase in the rotation direction of the drive shaft 11 the claw shaft parts 35, 37 are attached in the reverse or inward position, or at what phase in the rotation direction of the drive shaft 11 the claw shaft parts 35, 37 are attached in the reverse or outward position.

[0146] The posture detection unit (claw shaft blocking member 45, 46) detects that the claw shaft portion 35, 37 is attached to the drive shaft 11 in an inverted posture and an inward posture, and also detects that the claw shaft portion 35, 37 is attached to the drive shaft 11 in an inverted posture and an outward posture.

[0147] When the claw shaft portions 35, 37 are attached to the drive shaft 11 in the reverse and inward orientations, the claw shaft blocking members 45, 46 are operated to the attachment allowance position A12 by the operating portions 40, 41, and the forward rotation blocking member 50 is operated to the forward rotation blocking position B11 via the linking member 52. When the claw shaft portions 35, 37 are attached to the drive shaft 11 in the reverse and outward orientations, the claw shaft blocking members 45, 46 are operated to the attachment allowance position A12 by the operating portions 40, 41, and the forward rotation blocking member 50 is operated to the forward rotation blocking position B11 via the linking member 52.

[0148] The forward rotation restraint unit (forward rotation prevention member 50) prevents operation of the transmission device (forward / reverse rotation device 12) to the forward rotation position S11 when at least one of the following is detected: the right attitude detection unit (right claw shaft prevention member 45) detects that the claw shafts 35, 37 are attached to the right part of the drive shaft 11 in an inverted attitude; and the left attitude detection unit (left claw shaft prevention member 46) detects that the claw shafts 35, 37 are attached to the left part of the drive shaft 11 in an inverted attitude.

[0149] A right claw shaft blocking member 45 is provided which can be operated to an attachment blocking position A11 which prevents the attachment of the claw shaft portions 35, 37 to the right portion of the drive shaft 11, and an attachment allowing position A12 which allows the attachment of the claw shaft portions 35, 37 to the right portion of the drive shaft 11. A left claw shaft blocking member 46 is provided which can be operated to an attachment blocking position A11 which prevents the attachment of the claw shaft portions 35, 37 to the left portion of the drive shaft 11, and an attachment allowing position A12 which allows the attachment of the claw shaft portions 35, 37 to the left portion of the drive shaft 11. When the right claw shaft blocking member 45 is operated to the installation allowable position A12 and / or the left claw shaft blocking member 46 is operated to the installation allowable position A12, the forward rotation preventing member 50 is operated to the forward rotation preventing position B11 via the linking member 52.

[0150] When the transmission device (forward / reverse rotation device 12) is operated to the forward rotation position S11, the right claw shaft blocking member 45 and the left claw shaft blocking member 46 are held in the mounting blocking position A11 via the forward rotation blocking member 50 and the linking member 52.

[0151] (In the tillage equipment, the state after the forward / reverse rotation device is operated to the forward rotation position) As shown in Figure 12, when the forward rotation preventing member 50 is operated to the forward rotation allowing position B12, the speed change lever 6 (shift fork 34) is operated to the forward rotation position S11, and the forward / reverse rotation device 12 is operated to the forward rotation position S11, the engagement portion 34a of the shift fork 34 enters below the arm 50a of the forward rotation preventing member 50. As a result, the forward rotation preventing member 50 is held in the forward rotation allowing position B12, and the claw shaft preventing members 45, 46 are held via the forward rotation preventing member 50 and the linking member 52 in the mounting preventing position A11.

[0152] As shown in Figures 4, 8, and 12, when the claw shaft portions 35, 37 are attached to the drive shaft 11 in the reverse orientation and the inward orientation, when the claw shaft portion 35 is inserted into the right part of the drive shaft 11 from the operating portion 40 side, the operating portion 40 of the claw shaft portion 35 hits the right claw shaft blocking member 45, and the claw shaft portion 35 cannot be inserted any further into the right part of the drive shaft 11.

[0153] When the claw shaft portions 35, 37 are attached to the drive shaft 11 in an inverted and inward orientation, when the claw shaft portion 37 is inserted into the left part of the drive shaft 11 from the operating portion 41 side, the operating portion 41 of the claw shaft portion 37 hits the left claw shaft blocking member 46, and the claw shaft portion 37 cannot be inserted any further into the left part of the drive shaft 11.

[0154] As shown in Figures 4, 8, and 13, when the claw shaft portions 35, 37 are attached to the drive shaft 11 in the inverted and outward orientations, when the claw shaft portion 35 is inserted into the left portion of the drive shaft 11 from the operating portion 41 side, the operating portion 41 of the claw shaft portion 35 hits the left claw shaft blocking member 46, and the claw shaft portion 35 cannot be inserted any further into the left portion of the drive shaft 11.

[0155] When the claw shaft portions 35, 37 are attached to the drive shaft 11 in an inverted and inward orientation, when the claw shaft portion 37 is inserted into the right part of the drive shaft 11 from the operating portion 40 side, the operating portion 40 of the claw shaft portion 37 hits the right claw shaft blocking member 45, and the claw shaft portion 37 cannot be inserted any further into the right part of the drive shaft 11.

[0156] As described above, when the operating portions 40, 41 of the claw shaft portions 35, 37 are in contact with the claw shaft blocking members 45, 46 held at the mounting blocking position A11, the positions of the mounting holes 35a, 35b, 37a, 37b of the claw shaft portions 35, 37 shown in Figure 4 do not match the positions of the mounting holes 11a, 11b of the drive shaft 11.

[0157] As a result, the connecting pin 42 cannot be inserted through the mounting holes 35a, 35b, 37a, 37b of the claw shaft portions 35, 37 and the mounting holes 11a, 11b of the drive shaft 11, and the claw shaft portions 35, 37 cannot be connected to the drive shaft 11.

[0158] (In the tillage equipment, the state in which the tines are attached to the drive shaft in a forward position and an inward position, and a forward position and an outward position) - 1 As shown in Figures 4, 8, and 14, when the claw shaft portion 35 is inserted into the left part of the drive shaft 11 from the side of the operating portion 40 and the claw shaft portion 37 is inserted into the right part of the drive shaft 11 from the side of the operating portion 41, the left claw shaft blocking member 46 enters the recess 40a of the operating portion 40 of the claw shaft portion 35, and the outer periphery of the operating portion 41 of the claw shaft portion 37 enters below the right claw shaft blocking member 45.

[0159] 4 coincides with the positions of the mounting holes 11a and 11b of the drive shaft 11, so that the connecting pin 42 can be inserted through the mounting holes 11a and 11b of the drive shaft 11 and the mounting holes 35a and 37a of the claw shafts 35 and 37, connecting the claw shafts 35 and 37 to the drive shaft 11. This state is when the claw shafts 35 and 37 are attached to the drive shaft 11 in a forward and inward orientation.

[0160] As shown in Figures 4, 8, and 15, when the claw shaft portion 35 is inserted into the right part of the drive shaft 11 from the side of the operating portion 41 and the claw shaft portion 37 is inserted into the left part of the drive shaft 11 from the side of the operating portion 40, the outer periphery of the operating portion 41 of the claw shaft portion 35 enters below the right claw shaft blocking member 45, and the left claw shaft blocking member 46 enters the recess 40a of the operating portion 40 of the claw shaft portion 37.

[0161] As a result, the positions of 35b, 37b of the claw shaft portions 35, 37 coincide with the positions of the mounting holes 11a, 11b of the drive shaft 11, so that the connecting pin 42 can be inserted through 35b, 37b of the claw shaft portions 35, 37 and the mounting holes 11a, 11b of the drive shaft 11, thereby connecting the claw shaft portions 35, 37 to the drive shaft 11. This state is the state in which the claw shaft portions 35, 37 are attached to the drive shaft 11 in a forward and outward orientation.

[0162] When the claw shaft portions 35, 37 are attached to the drive shaft 11 in a forward and inward orientation, and when the claw shaft portions 35, 37 are attached to the drive shaft 11 in a forward and outward orientation, the claw shaft blocking members 45, 46 are not operated to the attachment allowable position A12 (they are left in the attachment blocking position A11).

[0163] As a result, the forward rotation preventing member 50 is not operated to the forward rotation preventing position B11 but remains in the forward rotation allowing position B12, so that the speed change lever 6 (shift fork 34) can be operated to the forward rotation position S11.

[0164] Conversely, suppose that the speed change lever 6 (shift fork 34) is operated to the normal rotation position S11, the normal rotation blocking member 50 is held in the normal rotation allowing position B12, and the pawl shaft blocking members 45, 46 are held in the mounting blocking position A11.

[0165] In this state, when the claw shaft portions 35, 37 are attached to the drive shaft 11 in a forward position and an inward position (forward position and outward position) as described above, the left claw shaft blocking member 46 fits into the recess 40a of the operating portion 40, and the outer periphery of the operating portion 41 fits below the right claw shaft blocking member 45, so that the claw shaft portions 35, 37 are attached to the drive shaft 11 in a forward position and an inward position (forward position and outward position) regardless of the claw shaft blocking members 45, 46.

[0166] The recess 40a of the operating part 40 is ring-shaped and is formed over the entire circumferential circumference of the operating part 40. The outer circumferential part (avoidance part) of the operating part 41 is formed over the entire circumferential circumference of the operating part 41.

[0167] As a result, even if the claw shaft portions 35, 37 are attached to the drive shaft 11 in any phase in the rotation direction of the drive shaft 11 in a forward or inward posture, and even if the claw shaft portions 35, 37 are attached to the drive shaft 11 in any phase in the rotation direction of the drive shaft 11 in a forward or outward posture, the operating portions 40, 41 will not come into contact with the claw shaft blocking members 45, 46.

[0168] (In the tillage equipment, the state in which the tines are attached to the drive shaft in a forward position and an inward position, and a forward position and an outward position) - 2 With the above-described configuration, as shown in Figures 8, 14, and 15, the operating parts 40, 41 are provided with avoidance parts (recesses 40a) that prevent the operating parts 40, 41 from hitting the claw shaft blocking members 45, 46 when the claw shaft parts 35, 37 are attached to the drive shaft 11 in the forward orientation and the inward orientation, and that prevent the operating parts 40, 41 from hitting the claw shaft blocking members 45, 46 when the claw shaft parts 35, 37 are attached to the drive shaft 11 in the forward orientation and the outward orientation.

[0169] The avoidance portion (recess 40a) is provided around the entire circumference of the operating portions 40, 41, and prevents the operating portions 40, 41 from hitting the claw shaft blocking members 45, 46 regardless of whether the claw shaft portions 35, 37 are attached to the drive shaft 11 in a forward or inward position and in any phase of the rotational direction of the drive shaft 11, or regardless of whether the claw shaft portions 35, 37 are attached to the drive shaft 11 in a forward or outward position and in any phase of the rotational direction of the drive shaft 11.

[0170] (First Alternative Embodiment of the Invention) A posture detection sensor (not shown) (corresponding to a posture detection section) may be provided to electrically detect that the claw shaft sections 35, 37 are attached to the drive shaft 11 in an inverted posture. In the above-described configuration, when the posture detection sensor detects that the claw shaft portions 35, 37 are attached to the drive shaft 11 in an inverted posture, a forward rotation restraining actuator (not shown) (corresponding to the forward rotation restraining portion) may be provided which prevents the forward / reverse rotation device 12 (transmission device) from being operated to the forward rotation position S11. As a result, the restraining section has an attitude detection sensor and a forward rotation restraining actuator.

[0171] (Second Alternative Embodiment of the Invention) A forward rotation detection sensor (not shown) (corresponding to a forward rotation detection section) may be provided to electrically detect that the forward / reverse rotation device 12 (transmission device) has been operated to the forward rotation position S11. In the above-described configuration, a claw shaft restraining actuator (not shown) (corresponding to the claw shaft restraining portion) may be provided that prevents the claw shaft portions 35, 37 from being attached to the drive shaft 11 in a reverse orientation when the forward / reverse rotation device 12 (transmission device) is detected by the forward rotation detection sensor to be operated to the forward rotation position S11. As a result, the restraining unit has a forward rotation detection sensor and a claw shaft restraining actuator.

[0172] (Third Alternative Embodiment of the Invention) It is also possible to provide a posture detection sensor (not shown) (corresponding to the posture detection unit) that electrically detects that the claw shaft portions 35, 37 are attached to the drive shaft 11 in an inverted posture, and a forward rotation detection sensor (not shown) (corresponding to the forward rotation detection unit) that electrically detects that the forward / reverse rotation device 12 (transmission device) has been operated to the forward rotation position S11.

[0173] In the above-described configuration, when the posture detection sensor detects that the claw shaft portions 35, 37 are attached to the drive shaft 11 in an inverted posture, a forward rotation restraining actuator (not shown) (corresponding to the forward rotation restraining portion) may be provided which prevents the forward / reverse rotation device 12 (transmission device) from being operated to the forward rotation position S11.

[0174] When the forward rotation detection sensor detects that the forward / reverse rotation device 12 (transmission device) has been operated to the forward rotation position S11, a claw shaft restraining actuator (not shown) (corresponding to the claw shaft restraining portion) may be provided which prevents the claw shaft portions 35, 37 from being attached to the drive shaft 11 in the reverse orientation. As a result, the restraining section has an attitude detection sensor, a normal rotation detection sensor, a normal rotation restraining actuator, and a claw shaft restraining actuator.

[0175] (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. [Industrial Applicability]

[0176] The present invention can be applied to a walk-behind cultivator in which a tilling device is provided at the rear of a machine body supported by a traveling device. [Explanation of symbols]

[0177] 1 Wheels (running gear) 2 Transmission case (airframe) 7 Tillage equipment 11 Drive shaft 12 Forward / reverse rotation device (transmission device) 35 Claw shaft 36 Cultivating Claw 37 Claw shaft 38 Cultivating Claw 40 Control section 40a Recess (avoidance part) 41 Operation section 45 Claw shaft blocking member (restraint part) (posture detection part) (claw shaft restraint part) 46 Claw shaft blocking member (restraint part) (posture detection part) (claw shaft restraint part) 50 forward rotation prevention member (restraint portion) (forward rotation detection portion) (forward rotation restraint portion) 52 Connecting members A11 Installation prevention position A12 Allowable mounting position B11 Forward rotation blocking position B12 Forward rotation allowable position N4 Stop position S11 Forward rotation position S12 Forward direction

Claims

1. a machine body supported by a running gear; a drive shaft supported along the left-right direction at the rear of the aircraft body; A tillage device having a claw shaft portion attached to the drive shaft and a tillage claw attached to the claw shaft portion and driven by the drive shaft; a transmission device operable to a forward rotation position in which the drive shaft transmits power to rotate 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 soil on the ground rearward, to the drive shaft, and a stop position in which power to the drive shaft is cut off; The claw shaft portion can be attached to the drive shaft in a forward orientation in which the portion of the tillage tine that is radially outward from the claw shaft portion is located on the upstream side of the normal rotation direction, and in a reverse orientation in which the portion of the tillage tine that is radially outward from the claw shaft portion is located on the downstream side of the normal rotation direction, a restraining portion that prevents the occurrence of a state in which the claw shaft portion is attached to the drive shaft in the reverse orientation and the transmission device is operated to the normal rotation position, The restraining unit is an attitude detection unit that detects that the claw shaft portion is attached to the drive shaft in the reverse attitude; a forward rotation inhibiting unit that inhibits operation of the transmission device to the forward rotation position when the attitude detecting unit detects that the claw shaft unit is attached to the drive shaft in the reverse attitude, a claw shaft blocking member operable to an attachment blocking position that blocks attachment of the claw shaft portion to the drive shaft and an attachment allowing position that allows attachment of the claw shaft portion to the drive shaft; an operating portion that is provided on the claw shaft portion and that, when the claw shaft portion is attached to the drive shaft in the inverted position, comes into contact with the claw shaft blocking member, thereby operating the claw shaft blocking member to the attachment allowable position; a forward rotation preventing member operable to a forward rotation preventing position that prevents operation of the transmission device to the forward rotation position, and a forward rotation allowing position that allows operation of the transmission device to the forward rotation position and prevents operation to the forward rotation preventing position when the transmission device is operated to the forward rotation position; a linking member connected across the forward rotation preventing member and the pawl shaft preventing member, When the claw shaft portion is attached to the drive shaft in the reverse orientation, the claw shaft blocking member is operated to the attachment allowance position by the operating portion, and the forward rotation blocking member is operated to the forward rotation blocking position via the linking member, When the forward rotation preventing member is operated to the forward rotation allowing position, the claw shaft preventing member is operated to the attachment preventing position via the linking member, and when the transmission device is operated to the forward rotation position, the claw shaft preventing member is held at the attachment preventing position via the forward rotation preventing member and the linking member, the claw shaft blocking member is the attitude detection unit, The forward rotation prevention member is the forward rotation restraining part of the walking-type tiller.

2. The tillage implement has a first claw shaft portion attached to one of the right and left portions of the drive shaft and a second claw shaft portion attached to the other of the right and left portions of the drive shaft, a right attitude detection unit that detects that the claw shaft portion is attached to the right part of the drive shaft in the reverse attitude; a left attitude detection unit that detects that the claw shaft portion is attached to the left part of the drive shaft in the reverse attitude, The walk-behind cultivator of claim 1, wherein the forward rotation restraint unit prevents the transmission device from being operated to the forward rotation position when at least one of the right attitude detection unit detects that the claw shaft unit is attached to the right part of the drive shaft in the reverse attitude, and the left attitude detection unit detects that the claw shaft unit is attached to the left part of the drive shaft in the reverse attitude.

3. The first claw shaft portion and the second claw shaft portion can be attached to the drive shaft in an inward position in which the tillage tines face the left-right central portion of the tillage device when viewed from behind, and in an outward position in which the tillage tines face outward from the left-right central portion of the tillage device when viewed from behind, The walking-type cultivator according to claim 2, wherein the posture detection unit detects that the claw shaft portion is attached to the drive shaft in the reverse posture and the inward posture, and detects that the claw shaft portion is attached to the drive shaft in the reverse posture and the outward posture.

4. a machine body supported by a running gear; a drive shaft supported along the left-right direction at the rear of the aircraft body; A tillage device having a claw shaft portion attached to the drive shaft and a tillage claw attached to the claw shaft portion and driven by the drive shaft; a transmission device operable to a forward rotation position in which the drive shaft transmits power to rotate 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 soil on the ground rearward, to the drive shaft, and a stop position in which power to the drive shaft is cut off; The claw shaft portion can be attached to the drive shaft in a forward orientation in which the portion of the tillage tine that is radially outward from the claw shaft portion is located on the upstream side of the normal rotation direction, and in a reverse orientation in which the portion of the tillage tine that is radially outward from the claw shaft portion is located on the downstream side of the normal rotation direction, a restraining portion that prevents the occurrence of a state in which the claw shaft portion is attached to the drive shaft in the reverse orientation and the transmission device is operated to the normal rotation position, The restraining unit is a normal rotation detection unit that detects that the transmission device is operated to the normal rotation position; a claw shaft restraining portion that prevents the claw shaft portion from being attached to the drive shaft in the reverse orientation when the normal rotation detection portion detects that the transmission device has been operated to the normal rotation position, a claw shaft blocking member operable to an attachment blocking position that blocks attachment of the claw shaft portion to the drive shaft and an attachment allowing position that allows attachment of the claw shaft portion to the drive shaft; an operating portion that is provided on the claw shaft portion and that, when the claw shaft portion is attached to the drive shaft in the inverted position, comes into contact with the claw shaft blocking member, thereby operating the claw shaft blocking member to the attachment allowable position; a forward rotation preventing member operable to a forward rotation preventing position that prevents operation of the transmission device to the forward rotation position, and a forward rotation allowing position that allows operation of the transmission device to the forward rotation position and prevents operation to the forward rotation preventing position when the transmission device is operated to the forward rotation position; a linking member connected across the forward rotation preventing member and the pawl shaft preventing member, When the claw shaft portion is attached to the drive shaft in the reverse orientation, the claw shaft blocking member is operated to the attachment allowance position by the operating portion, and the forward rotation blocking member is operated to the forward rotation blocking position via the linking member, When the forward rotation preventing member is operated to the forward rotation allowing position, the claw shaft preventing member is operated to the attachment preventing position via the linking member, and when the transmission device is operated to the forward rotation position, the claw shaft preventing member is held at the attachment preventing position via the forward rotation preventing member and the linking member, The claw shaft blocking member is the claw shaft restraining portion, The forward rotation prevention member is the forward rotation detection unit of the walking-type cultivator.

5. The tillage implement has a first claw shaft portion attached to one of the right and left portions of the drive shaft and a second claw shaft portion attached to the other of the right and left portions of the drive shaft, The walking-type cultivator according to claim 4, wherein the claw shaft restraining unit prevents the claw shaft from being attached to the right side of the drive shaft in the reverse position when the forward rotation detection unit detects that the transmission device has been operated to the forward rotation position, and prevents the claw shaft from being attached to the left side of the drive shaft in the reverse position.

6. a machine body supported by a running gear; a drive shaft supported along the left-right direction at the rear of the aircraft body; A tillage device having a claw shaft portion attached to the drive shaft and a tillage claw attached to the claw shaft portion and driven by the drive shaft; a transmission device operable to a forward rotation position in which the drive shaft transmits power to rotate 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 soil on the ground rearward, to the drive shaft, and a stop position in which power to the drive shaft is cut off; The claw shaft portion can be attached to the drive shaft in a forward orientation in which the portion of the tillage tine that is radially outward from the claw shaft portion is located on the upstream side of the normal rotation direction, and in a reverse orientation in which the portion of the tillage tine that is radially outward from the claw shaft portion is located on the downstream side of the normal rotation direction, a restraining portion that prevents the occurrence of a state in which the claw shaft portion is attached to the drive shaft in the reverse orientation and the transmission device is operated to the normal rotation position, The restraining unit is an attitude detection unit that detects that the claw shaft portion is attached to the drive shaft in the reverse attitude; a normal rotation detection unit that detects that the transmission device is operated to the normal rotation position; a forward rotation inhibiting unit that inhibits operation of the transmission device to the forward rotation position when the attitude detecting unit detects that the claw shaft unit is attached to the drive shaft in the reverse attitude; a claw shaft restraining portion that prevents the claw shaft portion from being attached to the drive shaft in the reverse orientation when the normal rotation detection portion detects that the transmission device has been operated to the normal rotation position, a claw shaft blocking member operable to an attachment blocking position that blocks attachment of the claw shaft portion to the drive shaft and an attachment allowing position that allows attachment of the claw shaft portion to the drive shaft; an operating portion that is provided on the claw shaft portion and that, when the claw shaft portion is attached to the drive shaft in the inverted position, comes into contact with the claw shaft blocking member, thereby operating the claw shaft blocking member to the attachment allowable position; a forward rotation preventing member operable to a forward rotation preventing position that prevents operation of the transmission device to the forward rotation position, and a forward rotation allowing position that allows operation of the transmission device to the forward rotation position and prevents operation to the forward rotation preventing position when the transmission device is operated to the forward rotation position; a linking member connected across the forward rotation preventing member and the pawl shaft preventing member, When the claw shaft portion is attached to the drive shaft in the reverse orientation, the claw shaft blocking member is operated to the attachment allowance position by the operating portion, and the forward rotation blocking member is operated to the forward rotation blocking position via the linking member, When the forward rotation preventing member is operated to the forward rotation allowing position, the claw shaft preventing member is operated to the attachment preventing position via the linking member, and when the transmission device is operated to the forward rotation position, the claw shaft preventing member is held at the attachment preventing position via the forward rotation preventing member and the linking member, the claw shaft blocking member is the attitude detection unit and the claw shaft restraining unit, The forward rotation preventing member is the forward rotation detecting section and the forward rotation restraining section of the walking type tiller.

7. The operating part is provided around the entire circumference of the claw shaft portion, and contacts the claw shaft blocking member regardless of the phase in the rotational direction of the drive shaft when the claw shaft portion is attached in the reverse position.

8. The tillage implement has a first claw shaft portion attached to one of the right and left portions of the drive shaft and a second claw shaft portion attached to the other of the right and left portions of the drive shaft, a right claw shaft blocking member operable to an attachment blocking position that blocks attachment of the claw shaft portion to the right portion of the drive shaft and an attachment allowing position that allows attachment of the claw shaft portion to the right portion of the drive shaft; a left claw shaft blocking member operable to an attachment blocking position that blocks attachment of the claw shaft portion to the left portion of the drive shaft and an attachment allowing position that allows attachment of the claw shaft portion to the left portion of the drive shaft, A walk-behind cultivator as described in any one of claims 1 to 6, wherein the forward rotation preventing member is operated to the forward rotation preventing position via the connecting member by at least one of the right claw shaft preventing member being operated to the installation allowable position and the left claw shaft preventing member being operated to the installation allowable position.

9. A walk-behind cultivator as described in claim 8, wherein when the transmission device is operated to the forward rotation position, the right claw shaft blocking member and the left claw shaft blocking member are held in the mounting blocking position via the forward rotation preventing member and the connecting member.

10. The tillage implement has a first claw shaft portion attached to one of the right and left portions of the drive shaft and a second claw shaft portion attached to the other of the right and left portions of the drive shaft, The first claw shaft portion and the second claw shaft portion can be attached to the drive shaft in an inward position in which the tillage tines face the left-right central portion of the tillage device when viewed from behind, and in an outward position in which the tillage tines face outward from the left-right central portion of the tillage device when viewed from behind, When the claw shaft portion is attached to the drive shaft in the reverse orientation and the inward orientation, the operating portion comes into contact with the claw shaft blocking member, thereby operating the claw shaft blocking member to the attachment allowable position, and when the claw shaft portion is attached to the drive shaft in the reverse orientation and the outward orientation, the operating portion comes into contact with the claw shaft blocking member, thereby operating the claw shaft blocking member to the attachment allowable position, an avoidance portion is provided on the operating portion, and when the claw shaft portion is attached to the drive shaft in the forward orientation or the inward orientation, the avoidance portion prevents the operating portion from hitting the claw shaft blocking member, and when the claw shaft portion is attached to the drive shaft in the forward orientation or the outward orientation, the avoidance portion prevents the operating portion from hitting the claw shaft blocking member; When the claw shaft portion is attached to the drive shaft in the reverse orientation and the inward orientation, the claw shaft blocking member is operated to the attachment allowance position by the operating portion, and the forward rotation blocking member is operated to the forward rotation blocking position via the linking member, A walk-behind cultivator described in any one of claims 1 to 6, wherein when the claw shaft portion is attached to the drive shaft in the reverse position and the outward position, the claw shaft blocking member is operated to the attachment allowance position by the operating unit, and the forward rotation blocking member is operated to the forward rotation blocking position via the connecting member.

11. The operating portion is provided around the entire circumference of the claw shaft portion, and abuts against the claw shaft blocking member regardless of the phase in the rotation direction of the drive shaft at which the claw shaft portion is attached in the reverse orientation or the inward orientation, and regardless of the phase in the rotation direction of the drive shaft at which the claw shaft portion is attached in the reverse orientation or the outward orientation, The avoidance portion is provided around the entire circumferential circumference of the operating portion, and prevents the operating portion from hitting the claw shaft blocking member regardless of the phase in the rotational direction of the drive shaft at which the claw shaft portion is attached to the drive shaft in the forward position or the inward position, or regardless of the phase in the rotational direction of the drive shaft at which the claw shaft portion is attached to the drive shaft in the forward position or the outward position.

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