JP5463088B2 - Farm machine connection device - Google Patents

Description

  The present invention relates to an agricultural machine connection device capable of automatically connecting a work machine to a three-point link connection mechanism provided in a tractor.

  A connecting device that connects a farm work machine to a three-point link connecting mechanism provided at the rear of a tractor using a connecting frame is generally known (see Patent Document 1).

  The connecting device described in Patent Document 1 includes a connecting frame connected to a three-point link connecting mechanism provided at the rear portion of the tractor, a hanger hook provided at an upper center position of the connecting frame, and both left and right sides of the connecting frame. An engagement plate connected to a three-point link coupling mechanism, a hook member rotatably provided on the outer surface of the engagement plate, and a position where the hook member is locked to the hitch pin. And a lock mechanism portion that can be locked at a position to be released.

  The engagement plate has a fitting hole in which a pair of hitch pins arranged on both sides in the width direction of the farm work machine can be fitted and detached by movement in the front-rear direction of the farm work machine engaged with the hanger hook. The hook member has an engaging recess that opens upward on the rotating end side and engages the hitch pin. The locking mechanism has one end connected to the pivot shaft of the hook member and extends upward to operate the hook member, and the hook member is a hitch pin. And a select plate that can be locked at a position to be locked and a position to be unlocked.

  The select plate has a linear elongated hole that guides the operating lever in the rotating direction of the rotating shaft, and a lever that extends in a direction perpendicular to the elongated hole at both ends of the elongated hole and locks the operating lever. A locking portion is provided. When the operating lever is positioned at the front lever locking portion of the select plate, the hook member rotates in the closing direction to lock the hitch pin, and when the operating lever is positioned at the rear lever locking portion, the hook member is The hitch pin is unlocked by rotating in the opening direction.

  On the other hand, a guide member for guiding the hitch pin to the hook member side is provided at the base of the hitch pin of the agricultural machine provided with the hitch pin even when the agricultural machine is displaced in the tractor width direction with respect to the tractor. The guide member has a truncated cone shape and is arranged coaxially with the hitch pin, and is provided at the base of the hitch pin with the inclined surface portion facing the tip side of the hitch pin. The outer diameter of the guide member is larger than that of the hitch pin.

  When the agricultural machine is connected to the tractor via the connecting device configured as described above, the operation lever is locked at the release position of the lever locking portion. The work implement is placed behind the tractor while being supported by a stand, and the tractor is moved backward to hook the front upper part of the farm work implement on the hanger hook. When the three-point link coupling mechanism is raised, the lower side of the farming machine moves forward and backward with the front upper part of the farming machine locked to the hanger hook as a pivot, and the hitch pin is provided on the engagement plate. Get into the hole. Here, when the position of the hitch pin in the width direction of the agricultural machine is shifted with respect to the hook member when the lower side of the agricultural machine moves to the front side in the front-rear direction, the guide member is connected according to the movement of the lower side of the agricultural machine. The hitch pin is guided to the hook member side while being in sliding contact with the lower portion of the frame.

  When the hitch pin is locked to the hook member, the operator switches the operation lever from the lever locking portion at the release position to the lever locking portion at the locking position. Thereby, a hook member rotates to a hitch pin side, a hitch pin is latched by a hook member, and a farm work machine is connected with a tractor via a connecting device.

Japanese Utility Model Laid-Open No. 2-148210 (Page 5-8, FIG. 1, FIG. 3, FIG. 4)

  When connecting the agricultural machine to the tractor in this way, the hook member is opened, but the hook member is accidentally closed and the front upper part of the agricultural machine locked to the hanger hook is rotated. When the lower side of the agricultural machine moves as a moving fulcrum to the front side in the front-rear direction, the hitch pin or the guide member comes into contact with the inclined surface formed at the tip of the hook member.

  The inclined surface inclines toward the connecting frame as it proceeds upward with the hook member closed. For this reason, when the hitch pin or the guide member comes into contact with the inclined surface, the force of the lower component of the external force that is perpendicular to the inclined surface tries to rotate the hook member in the opening direction. Since the lever is locked to the lever locking portion, the hook member does not rotate. As a result, the external force acting on the hook member also acts on the operation lever and the lever locking portion, which may cause damage.

  The present invention has been made in view of such a background, and when the farm work machine is mounted on the tractor via the coupling device, when the farm work machine is mounted even if the hook member is closed due to an erroneous operation. It is another object of the present invention to provide a coupling device for a farm machine that does not cause damage to an operation lever or a lever locking portion of the lock mechanism.

In order to solve such a problem, the present invention includes a connecting frame connected to a three-point link connecting mechanism provided at the rear of the tractor, a hanger hook provided at the center upper portion of the connecting frame in the tractor width direction, A pair of frames disposed on both sides in the tractor width direction of the connection frame below the hanger hook and coupled to the three-point link coupling mechanism, and disposed on both sides in the width direction of the agricultural machine (for example, the tilling machine 1 in the embodiment). An engagement plate having a fitting hole in which the hitch pin can be fitted / detached, and a hook provided on the side surface of the engagement plate so as to be pivotable in the vertical direction and capable of locking the hitch pin fitted in the fitting hole. A coupling device for an agricultural machine comprising a hook member having a joint recess, and a lock mechanism portion that is connected to the hook member and can be locked at a locking position where the hook member locks the hitch pin and a release position where the hook member is unlocked. H The pivoting fulcrum of the hook member is an external force that causes the hitch pin to come into contact with the tip of the hook member when the farm work machine hooked on the hanger hook moves forward while the hook member is locked in the locking position by the lock mechanism. The hook member is provided with a planar contact surface that is perpendicular to the direction of the external force through the contact point where the external force is in contact with the tip part. .

  The hitch pin provided on the farm machine side may be either one that extends in the width direction (lateral direction) of the farm machine or one that extends in the vertical direction. In the case where the hitch pin extends in the horizontal direction, the hook member that locks the hitch pin is one that can be pivoted up and down around a pivot shaft that extends in the horizontal direction, and the hitch pin extends in the vertical direction. In the case of the case, a thing that is rotatable in the front-rear direction around a rotation axis extending in the vertical direction is used.

  The locking mechanism may be any mechanism that can be locked to the locking position where the hook member is locked to the hitch pin and the unlocking position where the hook member is unlocked, either manually performed by the operator or automatically performed by the actuator. But you can.

  The movement of the agricultural machine hooked on the hanger hook to the front side means that the lower side of the agricultural machine moves to the front side (the tractor side) using the upper part of the front side of the agricultural machine hooked on the hanger hook as a rotation fulcrum. .

  What the agricultural work machine contacts with the tip of the hook member when moving forward is not limited to the hitch pin, but may be a guide member that projects from the hitch pin to the hook member side and guides the hitch pin to the hook member. The guide member only needs to be able to guide the hitch pin to the hook member side when the agricultural machine moves to the front side. Specifically, the guide member is attached to the hitch pin coaxially with the hitch pin, and the tip side or base of the hitch pin It may be a truncated cone shape having an inclined surface that inclines toward the hitch pin as it goes to the end side, or a plate shape that is attached to the hitch pin and extends toward the tractor and has the aforementioned inclined surface.

  The contact surface provided at the tip of the hook member extends in a direction orthogonal to the direction of the external force through a contact point where the external force acting when the hitch pin or the guide member contacts the tip of the hook member passes through the contact point. (Claims 1 and 2).

  Thereby, when the agricultural machine is mounted on the tractor, the external force acting on the contact surface with which the hitch pin or the guide member abuts is directed to the pivot fulcrum side of the hook member. There are no ingredients. For this reason, the hook member does not rotate, and all of the external force can be received at the rotation fulcrum of the hook member. Therefore, when the agricultural machine is mounted on the tractor, no external force acts on the lock mechanism, and the lock mechanism can be prevented from being damaged.

According to the coupling device of the agricultural machine according to the present invention, the hitch pin or the guide member is hooked when the agricultural machine hooked on the hanger hook is moved forward while the hook member is locked at the locking position by the lock mechanism. A rotation fulcrum of the hook member is provided on the extension line of the direction of application of the external force that contacts the tip of the member, and the direction of the external force passes through the contact point that contacts the tip at the tip of the hook member that contacts the external force. By providing a flat contact surface orthogonal to the tractor of the agricultural machine, the hook member is inadvertently closed, that is, the locking mechanism portion prevents the hook member from rotating. Even if the mounting operation is continued without noticing that it is locked in position, the external force acting on the contact surface of the hitch pin or guide member is directed toward the rotation fulcrum side of the hook member. No direction component to rotate the hook member in the. For this reason, the hook member does not rotate, and all of the external force can be received at the rotation fulcrum of the hook member. Therefore, no external force acts on the lock mechanism portion, and damage to the lock mechanism portion can be prevented.

The side view of the tilling work machine connected with the tractor via the connecting device of the farm work machine of the present invention is shown. Fig.2 (a) shows the front side perspective view of the agricultural machine with which the connecting device of the agricultural machine of this invention was connected, and was supported by the stand, FIG.2 (b) is the arrow II of the same figure (a). The perspective view of the hitch pin and guide member which were provided in the corresponding mounting plate is shown. The top view of the connecting device of the agricultural machine concerning one embodiment of the present invention is shown. The side view of the connecting device of the agricultural machine concerning one embodiment of the present invention is shown. The fragmentary perspective view of the locking device which is a part of the coupling device of the agricultural working machine concerning one embodiment of the present invention is shown. The side surface for demonstrating the relationship between the external force which acts on a hook member when a hitch pin or a guide member contact | abuts to the front-end | tip part of the hook member which is a part of the coupling device of the agricultural machine concerning one Embodiment of this invention, and a hook member. FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a connecting device for agricultural machines according to the present invention will be described with reference to FIGS. First, before explaining the coupling device of a farm work machine, the tilling work machine which is an example of the farm work machine connected with a coupling device is demonstrated. In addition, as a farm work machine, a plow coater and a ditching machine may be used in addition to a plow work machine.

  As shown in FIG. 1 (side view) and FIG. 2 (a) (front perspective view), the tilling work machine 1 is attached to the rear portion of the tractor 90 and proceeds with the forward traveling of the tractor 90 to perform the tilling work. It is. The tilling work machine 1 has a main body frame 10 that extends in the left-right direction (hereinafter, simply referred to as “left-right direction”) with respect to the traveling direction. A transmission case 11 and a support frame 13 are provided on both left and right sides of the main body frame 10, and a tilling rotor 15 is rotatably supported between the lower sides thereof.

  A gear box 19 having an input shaft 19a for inputting power from the tractor 90 is provided at the center in the left-right direction of the main body frame 10, and the power extracted from the tractor 90 is transmitted to the input shaft 19a through a universal joint or the like. Is done. The power transmitted to the input shaft 19 a rotates the tilling rotor 15 via a power transmission mechanism provided in the main body frame 10 and the transmission case 11.

  A shield cover 17 is disposed above the tilling rotor 15, and the front end portion is rotatable at the rear end portion in the front-rear direction (hereinafter simply referred to as “front-rear direction”) with respect to the traveling direction of the shield cover 17. An apron 21 that is attached to the rear side and extends rearward obliquely rearward is provided. On the both sides of the apron 21 in the width direction, there are provided extended leveling plates 22 that are rotatably attached in the vertical direction.

  A pair of mounting plates 24 are provided on both sides in the left-right direction of the main body frame 10 with the gear box 19 in the center, the base end side being fixed to the main body frame 10 and extending to the front side and the front end portion protruding from the front end portion of the shield cover 17. It has been. A pair of hitch pins 26 are provided at the respective distal end portions of the mounting plates 24, and the base end sides are fixed to extend outward in the main body frame width direction in a substantially horizontal direction. These hitch pins 26 are connected to a connecting device 40 attached to the rear part of the tractor 90.

  2B (perspective view) will be further described on the proximal end side of the hitch pin 26. When the tiller work machine 1 is displaced in the tractor width direction with respect to the tractor 90, the hitch pin 26 is hooked. A guide member 35 that guides to the side is provided. The guide member 35 has a truncated cone shape and is disposed substantially coaxially with the hitch pin 26. A guide surface 35a that inclines toward the hitch pin side as it advances toward the front end side of the hitch pin 26 is provided at an axially intermediate portion of the guide member 35. Is provided.

  An arcuate peripheral surface 35b is formed at the end of the guide surface 35a on the mounting plate side. The diameter of the guide plate 35 a at the end of the mounting plate (the diameter of the peripheral surface 35 b) is larger than that of the hitch pin 26. For this reason, when the tilling work machine 1 is displaced in the tractor width direction with respect to the tractor 90, the guide surface 35a comes into contact with a lower end portion of a connecting frame 41 (to be described later) of the connecting device 40 to guide the hitch pin 26 to the hook member side. be able to.

  In the hitch pin 26, a guide collar 27 is inserted on the outer peripheral surface of the hitch pin 26 in order to facilitate the insertion of the hitch pin 26 into an engagement recess of the hook member 55 described later. The guide collar 27 is rotatably attached to the hitch pin 26. The guide collar 27 may be attached in a state of being fixed to the hitch pin 26.

  A top mast 28 that extends obliquely upward on the front side is provided on the upper portion of the gear box 19. A locking pin 28 a extending in a substantially horizontal direction is provided at the upper end portion of the top mast 28, and both end portions of the locking pin 28 a protrude from the left and right side surfaces of the upper end portion of the top mast 28. The protruding locking pin 28a is connected to a connecting device 40 described later. The tilling work machine 1 connected to the rear portion of the tractor 90 via the connecting device 40 can be moved up and down with respect to the rear portion of the tractor 90 by the vertical swing of the three-point link connecting mechanism 91.

  The three-point link coupling mechanism 91 has a top link 92 that is pivotally attached to the center in the width direction of the rear portion of the tractor and extends rearward, and a base end portion that is rotatable on both sides of the tractor in the width direction. And a pair of lower links 93 that extend rearward, and a lifting cylinder (not shown) that is connected to the lower link 93 and that moves the three-point link connecting mechanism 91 up and down.

  A support frame 30 extending outward in the main body frame width direction is provided at each tip of the pair of mounting plates 24. A pair of gauge rings 32 are provided on the base end side of the support frame 30 so as to be adjustable in height, and are detachably attached to the support frame 30 on the tip end side of the support frame 30. A caster stand 34 is provided. By inserting the caster stand 34 into the support frame 30, the tilling work machine 1 can be stored in a state where it is separated from the tractor 90. FIG. 1 shows a state where the tiller 90 with the caster stand 34 removed is attached to the tractor 90.

  As shown in FIG. 3 (plan view) and FIG. 4 (side view), the connecting device 40 is provided at a connecting frame 41 connected to the three-point link connecting mechanism 91 and at the center upper portion of the connecting frame 41 in the tractor width direction. Hanger hooks 45, engagement plates 49 disposed on both sides in the tractor width direction of the connecting frame 41 below the hanger hooks 45, and provided on the outer side surfaces of the engagement plates 49 so as to be rotatable in the vertical direction. And a locking mechanism portion 60 that is connected to the hook member 55 and can be locked at a locking position Pr for locking the hook member 55 to the hitch pin 26 and a release position Pf for unlocking.

  The connection frame 41 is a frame body that protrudes upward and is formed in a C shape. A hanger hook 45 is provided on the top 41 a of the connection frame 41. The hanger hook 45 is composed of a pair of plate members 46 arranged to face the top 41a of the connection frame 41 with a predetermined interval. The plate member 46 includes a connecting portion 46a extending obliquely upward from the top portion 41a toward the tractor side, and a hook portion 46b extending obliquely downward from the top portion 41a toward the tillage work machine side. The hook portion 46b is provided with an engaging concave portion 46c extending downward so that the locking pin 28a (see FIG. 1) can be hooked.

  The connecting portion 46a is provided with a plurality of through holes 46d with a predetermined interval in the vertical direction. These through-holes 46d are opposed to corresponding through-holes 46d of the plurality of through-holes 46d provided in the other plate member 46 arranged to face each other. A tip portion of a top link 92 that constitutes the three-point link coupling mechanism 91 is disposed between a pair of opposing plate members 46, and a pair of through holes 46d that are opposed to each other and a through hole that is provided at the tip portion of the top link 92 By inserting the locking pin 28a (see FIG. 1), the tip portion of the top link 92 is rotatably attached to the hanger hook 45.

  The engagement plates 49 disposed on both sides of the connecting frame 41 in the tractor width direction have a substantially rectangular shape in a side view, and the front lower portion thereof is fixed to the connecting frame 41. A locking pin 49b that protrudes outward is provided at the lower front side of the engagement plate 49, and the tip of the lower link 93 is rotatably attached to the locking pin 49b.

  On the rear side of the engagement plate 49, there are provided fitting holes 49a in which a pair of hitch pins 26 arranged on both sides in the width direction of the tilling work machine 1 can be fitted and detached. The fitting hole 49a extends in the front-rear direction and opens at the rear end side, and the opening of the fitting hole 49a expands outward to facilitate the insertion of the hitch pin 26 into the fitting hole 49a. The pair of engagement plates 49 are reinforced by a connecting member 50 connected between the insides.

  A hook member 55 is provided on the outer surface of the engagement plate 49 so as to be rotatable in the vertical direction. The hook member 55 is formed in a semicircular shape in a side view, and a front lower portion of the hook member 55 is rotatably attached to an engagement pin 51 projecting from an engagement plate 49. For this reason, the hook member 55 is freely rotatable in the vertical direction with the engagement pin 51 as the rotation fulcrum O. At the lower rear side of the hook member 55, an engaging recess 56 is provided that can latch the hitch pin 26 inserted into the fitting hole 49a from above. The engaging recess 56 is open at the lower rear side of the hook member 55. Details of the hook member 55 will be described later.

  A torsion coil spring 58 is provided between the inner surface of the hook member 55 and the outer surface of the engagement plate 49 to urge the hook member 55 toward the hitch pin 26 (clockwise direction) inserted into the fitting hole 49a. Yes.

  These hook members 55 are provided with a lock mechanism portion 60 that can be locked at a lock position Pr for locking the hitch pin 26 and a lock position Pf for unlocking. The lock mechanism 60 includes a connecting member 61 that is pivotably connected to the corresponding hook member 55 at both ends, an operating lever 62 that is fixed to the top of the connecting member 61, and a hook that is operated according to the operation of the operating lever 62. The member 55 includes a lever locking plate 64 that locks the movement of the operation lever 62 so that the hook member 55 is maintained at the locking position Pr for locking the hitch pin 26 and the unlocking position Pf for unlocking.

  The connecting member 61 of the lock mechanism 60 extends along the connecting frame 41 and is formed in a C shape when viewed from the front. The upper side of the connecting member 61 extends to the front of the connecting frame through the outer side of the connecting frame 41, and the top of the connecting member 61 is disposed in the vicinity of the upper portion of the connecting frame 41. As shown in FIG. 5, the operation lever 62 has a lower end portion fixed to the top of the connecting member 61 and extending upward, and is connected to the upper end portion of the lever support portion 62a and bent to one side in the left-right direction. It has a lever operating portion 62b that extends and has a handle 62c at the tip.

  At the upper part of the lever support 62a, a locking projection 63 is provided that is fixed to the side surface and extends along the side surface. The lower end portion of the locking projection 63 abuts on a lever locking plate 64 described later, and locks the downward movement of the operation lever 62.

  A hook spring 70 is provided on the base end side of the lever operation portion 62b. The hook spring 70 is rotatably inserted in the vertical direction. The hook spring 70 is formed in a frame shape by bending a linear body, and one end side is open. The end of the hook spring 70 on the opening side is inserted into a hole 62d provided on the base end side of the lever operating portion 62b and is rotatably supported, and the distal end side of the hook spring 70 is bent to be a lever locking plate. A locking portion 70 a that can be locked to the protruding portion 65 provided at 64 is formed. When the locking portion 70a of the hook spring 70 is locked to the lever locking plate 64, the upward movement of the operation lever 62 with respect to the lever locking plate 64 can be restricted.

  The lever locking plate 64 is attached to the front side of the top portion 41a of the connecting frame 41 and has an operation plate portion 66 extending in the front-rear direction. The operation plate portion 66 is provided with a select hole 67 through which the lever support portion 62a of the operation lever 62 and the locking projection 63 can be inserted. The select hole 67 is connected to the other end side of the rectangular hole portion 67a and is connected to the other end side of the rectangular hole portion 67a so as to communicate with the other end side of the rectangular hole portion 67b. It has. The arc-shaped hole 67b is provided so as to be shifted to one side in the width direction of the rectangular hole 67a. For this reason, the lower surface of the locking projection 63 is placed on the operation plate part beyond the other end of the arcuate hole 67b with the lever support part 62a of the operation lever 62 positioned at the arcuate hole 67b. An abutting surface portion 66a that can abut is formed.

  The protrusion 65 described above that locks the locking portion 70 a of the hook spring 70 is provided at one end in the width direction of the lever locking plate 64 and on the side of the select hole 67.

  The operation of the lock mechanism 60 and the hook member 55 configured in this manner will be described based on FIGS. 4 and 5 separately for the case where the tilling work machine 1 is attached to the tractor 90 and the case where it is removed from the tractor 90. In order to mount the tilling work machine 1 to the tractor 90, the hook spring 70 is raised before mounting to release the locked state of the hook spring 70 with respect to the lever locking plate 64, and the operating lever 62 is pulled up to lock the operating lever 62. When the projecting portion 63 is hooked on the contact surface portion 66a, the hook member 55 moves to the open release position Pf where the hitch pin 26 is unlocked.

  Then, the tractor 90 is brought closer to the tillage work machine side, the top mast 28 is hooked on the hanger hook 45, the three-point link coupling mechanism 91 is swung upward, and the tillage work machine 1 is lifted. When the tilling work machine 1 is lifted, the lower side of the tilling work machine 1 moves to the tractor side with the front upper part of the tilling work machine 1 hooked on the hanger hook 45 as a pivot, and the hitch pin 26 is fitted into the fitting hole 49a. Inserted into.

  After confirming that the hitch pin 26 has been inserted into the fitting hole 49a, the operating lever 62 is pulled up to remove the locking projection 63 of the operating lever 62 from the abutting surface 66a, and the lever support 62a into the arcuate hole 67b. The operation lever 62 is pushed down in the moved state. When the operation lever 62 is pushed down, the hook member 55 is rotated around the rotation fulcrum O toward the hitch pin 26 (clockwise) with the urging force of the torsion coil spring 58 being urged. The hitch pin 26 is inserted into the mating recess 56, the hook member 55 moves to the closed locking position Pr for locking the hitch pin 26, and the tilling work machine 1 is attached to the tractor 90 via the coupling device 40. The

  When it is confirmed that the hitch pin 26 is locked, the hook spring 70 is rotated downward to be locked with respect to the lever locking plate 64 to prevent the hitch pin 26 from being inadvertently detached from the hook member 55. .

  On the other hand, when removing the tilling work machine 1 from the tractor 90, the tilling work machine 1 is lifted by the three-point link connecting mechanism 91, and then the hook spring 70 is raised to release the locked state. When the operation lever 62 is pulled up and the locking projection 63 of the operation lever 62 is hooked on the contact surface 66a, the hook member 55 moves to the release position Pf in the open state. In this state, when the tilling work machine 1 is lowered by the three-point link coupling mechanism 91, the hitch pin 26 is removed from the fitting hole 49a, and the top mast 28 is detached from the hanger hook 45. Detach from tractor 90.

  The pivot fulcrum O of the hook member 55 for locking and unlocking the hitch pin 26 in this way will be described with reference to FIGS. 1 and 6 (side view). In a state in which 55 is locked at the locking position Pr, when the lower side of the tilling work machine 1 moves to the connecting frame 41 side with the position where the upper side of the tilling work machine 1 is hooked on the hanger hook 45 as a rotation fulcrum Q. The hitch pin 26 or the guide member 35 is provided on an extension line in the direction of application of the external force F that comes into contact with the tip of the hook member 55.

  Further, a contact surface 55a that is orthogonal to the direction of the external force F is provided at the front end portion of the hook member 55 with which the hitch pin 26 or the guide member 35 abuts, through the contact S where the external force F contacts the front end portion.

  As a result, when the tiller 90 is mounted on the tractor 90, the operation of moving the hook member 55 to the release position Pf is forgotten and the upper side of the tiller implement 1 is in the state where the hook member 55 is in the locking position Pr. When the lower side of the tillage work machine 1 moves forward in the front-rear direction while being hooked on the hanger hook 45, the hitch pin 26 or the guide member 35 comes into contact with the contact surface 55a.

  Normally, when the tilling work machine 1 is mounted on the tractor 90, the mounting work is performed at a flat installation place. In this case, the position of the hitch pin 26 and the guide member 35 in the tractor width direction is not substantially deviated from the tractor 90 in a state where the upper side of the tilling work machine 1 is hooked on the hanger hook 45. Therefore, when the lower side of the tillage work machine 1 is moved to the connecting frame 41 side, the guide member 35 does not contact the hook member 55 and the hitch pin 26 contacts the hook member 55.

  On the other hand, when the mounting work is performed at a place where the tiller working machine 1 is not flat, the tractor width direction of the hitch pin 26 and the guide member 35 is set while the upper side of the tiller working machine 1 is hooked on the hanger hook 45. The position shifts with respect to the tractor 90, and the guide member 35 having a larger diameter than the hitch pin 26 contacts the hook member 55 when moving to the front side in the front-rear direction under the tillage work machine.

  Here, since the direction of the external force F acting when the hitch pin 26 or the guide member 35 abuts against the abutment surface 55a is directed toward the pivot fulcrum side of the hook member 55, the external force F is a direction in which the hook member 55 is pivoted. Has no ingredients. For this reason, the hook member 55 does not rotate, and all of the external force F is received by the engagement pin 51 that is the pivot point of the hook member 55. Accordingly, no external force is applied to the lock mechanism portion 60 connected to the hook member 55, so that the lock mechanism portion 60 is not damaged.

1 Tillage work machine (agricultural work machine)
26 Hitch pin 35 Guide member 40 Connecting device 41 Connecting frame 45 Hanger hook 49 Engaging plate 49a Fitting hole 55 Hook member 55a Abutting surface 56 Engaging recess 60 Lock mechanism 90 Tractor 91 Three-point link connecting mechanism F External force Pf release position Pr lock position S contact

Claims (2)

A connecting frame connected to a three-point link connecting mechanism provided at the rear of the tractor, a hanger hook provided at the upper center of the connecting frame in the tractor width direction,
A pair of hitch pins arranged on both sides of the tractor in the tractor width direction of the connecting frame below the hanger hook and connected to the three-point link connecting mechanism can be fitted and detached. An engagement plate having a fitting hole,
A hook member provided on the side surface of the engagement plate so as to be rotatable in the vertical direction and having an engagement recess capable of locking the hitch pin fitted in the fitting hole;
A coupling device for an agricultural machine including a lock mechanism portion that is coupled to the hook member and can be locked at a latching position where the hook member latches the hitch pin and a unlocking position where the latch is released.
The pivot fulcrum of the hook member is configured so that the hitch pin is moved to the hook member when the farm work machine hooked on the hanger hook moves forward while the hook member is locked at the locking position by the lock mechanism. Provided on the extension line of the direction of action of the external force that contacts the tip of
A connecting device for a farm working machine, characterized in that a flat contact surface orthogonal to the direction of the external force is provided at a tip portion of the hook member through a contact point where the external force contacts the tip portion. The hitch pin is provided with a guide member that projects from the hitch pin to the hook member side and guides the hitch pin to the hook member side,
The pivot fulcrum of the hook member is configured such that the guide member is hooked when the farm work machine hooked on the hanger hook is moved forward while the hook member is locked at the locking position by the lock mechanism. Provided on the extension line of the acting direction of the external force contacting the tip of the member,
2. The connection of an agricultural machine according to claim 1 , wherein the contact surface extends in a direction perpendicular to the direction of the external force through a contact point where the guide member contacts the tip of the hook member. apparatus.

Images