JP2013170417A - Dump link mechanism for work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dump link mechanism for a work machine in which a dump angle (or a scoop angle) can be changed easily without adding a new component.SOLUTION: A dump link mechanism 26 is configured to perform a dump or scoop operation of an attachment such as a bucket 23 mounted to a distal end of a lift arm 22 which can be oscillated in a vertical direction by a lift cylinder 21. The dump link mechanism 26 comprises a plurality of link members (a connecting rod 26a, a crank 26b, a snap hitch 26c) connected to a dump cylinder 25 and transferring power of the dump cylinder 25 to the attachment. Inter-linking positions of any two of the plurality of link members can be selected at least in two positions and a dump angle of the attachment can be changed in accordance with the selected positions.

Description

  The present invention relates to a dump link mechanism of a work machine, and more particularly, to a dump link mechanism in which a dump angle can be adjusted by replacing a connecting pin of the link mechanism.

  The work implement is an attachment device that is detachably attached to the front side or the rear side of the tractor, and the one that is attached to the front side of the tractor 10 as shown in FIG. The front loader 20 has a lift arm 22 that is swung up and down by a lift cylinder 21, and a fork, a grader, a roll grab, a container bucket, a loading hook, etc. Various tip attachments can be attached according to the work contents.

  For example, earth and sand, compost, livestock excrement collection, compost reversal, snow removal, digging, ditching, light digging for agriculture, etc. are attached with bucket 23, and grass, rice straw, remaining trunks, etc. are attached with mania forks, vegetables Containers, boxes, pallets are transported with a pallet fork, and timber, earthen pipes, pipes are transported and rooted with a loading hook.

  Then, by operating the joystick type operation lever 24 provided in the driver's seat of the tractor 10 to the 9 position of FIG. In addition to each individual operation, combined operations such as tilting the attachment forward (dump) or tilting backward (squeeze) while raising or lowering the lift arm can be performed.

  The front loader 20 is equipped with a self-leveling mechanism that raises and lowers the attachment while maintaining the horizontal state so that the load does not collapse even when the lift arm 22 is raised and lowered, for example, in a pallet carrying operation. This self-leveling mechanism includes a mechanical type using a parallel link as in Patent Document 1 (Japanese Patent Publication No. 2002-507263) and a hydraulic type as in Patent Document 2 (Japanese Patent Laid-Open No. 07-109741). In the hydraulic type, when the lift arm is moved up and down, the oil on the return side of the lift cylinder on the proximal end side is sent to the dump cylinder on the distal end side to move the lift arm while maintaining the horizontal state of the attachment. This is advantageous in that the structure is simple and light weight and the work view from the driver's seat is good.

  The front loader 20 of FIG. 6 is equipped with a hydraulic leveling mechanism and has a hydraulic system that sends oil on the return side of the lift cylinder 21 to the dump cylinder 25 on the tip side. The attachment such as the bucket 23 at the tip of the lift arm 22 is connected to the tip of the piston rod 25 a of the dump cylinder 25 via the dump link mechanism 26, and the lift by the cooperative action of the hydraulic leveling mechanism and the dump link mechanism 26. Even when the arm 22 is moved up and down, the attachments such as the bucket 23 are kept horizontal.

  There are various types of work using the front-end attachment of the front loader 20, and when the lifting height of the attachment is required preferentially, such as turning over compost, removing snow, loading on a truck bed, etc., vegetable containers, wrapping There are various cases where the lifting force of the attachment is required preferentially, such as when a roll is transported. In order to cope with such various operations with one front loader 20, there is one in which the mounting position of the lift cylinder 21 with respect to the main frame 27 can be changed as shown in FIG. That is, the tip of the piston rod 21a of the lift cylinder 21 can be selectively connected to either of the upper and lower two positions A and B of the main frame 27, and when the lifting height is prioritized, the upper coupling position A and the lifting force are prioritized. In this case, the tip of the piston rod 21a is connected to the lower connection position B.

  In such a front loader 20, the rotation angle of the attachment such as the bucket 23 can be increased by the combination of the self-leveling mechanism and the dump link mechanism described above. For example, earth and sand, compost, etc. can be dumped smoothly and speedily. be able to. However, on the other hand, although the convenience is improved, especially when the connecting position of the lift cylinder 21 is set to the lower connecting position where the lifting force is prioritized as described above, the lifting height is lowered, depending on the work contents. The lifting height of the attachment may be slightly insufficient, or the dump angle may be too deep (too large). On the other hand, when the connection position of the lift cylinder 21 is raised to the upper connection position with priority on height, the dump angle of the attachment may be slightly too shallow (too small) depending on the work contents.

Special Table 2002-507263 Publication (* Parallel link) Japanese Patent Laid-Open No. 9-165572 (* dump angle adjusting cylinder) Japanese Utility Model Publication No. 7-2553 (* potentiometer)

  As a technique for adjusting the dump angle, there is a technique in which a dump angle adjustment cylinder is separately provided as in Patent Document 2 (Japanese Patent Laid-Open No. 9-165773, dump angle adjustment cylinder), or Patent Document 3 (Japanese Utility Model Laid-Open No. 7-2553) A potentiometer, such as a potentiometer, is provided and the maximum dump angle is regulated by controlling a hydraulic system. However, in any case, the number of parts increases, the structure becomes complicated, and the cost increases.

  The objective of this invention is providing the dump link mechanism of the working machine which can change a dump angle (or squeeze angle) easily, without adding a new component.

The present invention solves the above problems by the following means (1) to (11).
(1) A lift arm that can be swung in a vertical direction by a lift cylinder, an attachment that is supported at the tip of the lift arm so as to be able to swing in a vertical direction, and the lift for swinging the attachment in a vertical direction The dump link mechanism of a working machine comprising: a dump cylinder attached to an arm; and a dump link mechanism including a plurality of link members that transmit the force of the dump cylinder to the attachment, wherein any of the link members A dump link mechanism characterized in that two interconnection positions can be selected at at least two positions, and the dump angle of the attachment can be changed by the selected positions.

(2) A snap hitch in which the dump link member is detachably engaged with the attachment, a connecting rod for connecting the snap hitch to the dump cylinder, and a force of the dump cylinder in cooperation with the connecting rod. The dump link mechanism according to (1), further comprising: a crank that transmits to the drum.

(3) The dump link mechanism according to (2), wherein the snap hitch has two pin holes for connecting to a connecting rod.

(4) The dump link mechanism according to (2), wherein the crank has a dedicated pin hole for selectively connecting the dump cylinder alone, in addition to a common pin hole for connecting the connecting rod and the dump cylinder.

(5) The dump link mechanism according to (2), wherein the connecting rod has a dedicated pin hole for selectively connecting the dump cylinder alone, in addition to the common pin hole for connecting the crank and the dump cylinder.

(6) The dump link mechanism according to any one of (1) to (5), including a hydraulic self-leveling mechanism.

(7) The dump link mechanism according to any one of (1) to (5), which includes a mechanical parallel link mechanism.

(8) The dump link according to any one of (1) to (7), wherein a shaft hole that connects one end of the lift cylinder is formed in at least two positions on a main frame of a work machine attached to the tractor. mechanism.

(9) Any one of (1) to (7), wherein a shaft hole for connecting the other end of the lift cylinder is formed in at least two positions on an intermediate plate attached to an intermediate position in the longitudinal direction of the lift arm. The dump link mechanism described in 1.

(10) The dump link mechanism according to (8) or (9), wherein a guide portion that guides an end portion of a lift cylinder is formed between the at least two shaft holes.

(11) The dump link mechanism according to (10), wherein a docking pin with a stopper biased by a spring can be selectively inserted into the at least two shaft holes.

  According to the dump link mechanism of the present invention, since any two interconnection positions of the link member can be selected at at least two positions, at least two different dump angles can be set without additional parts, for example, the lifting height Can be set to a dumping angle that gives priority to lifting, or a dumping angle that gives priority to lifting force. Work that is one rank higher is possible compared to class machines.

It is a side view of the tractor which attached the front loader with a bucket. It is a side view of the tractor which attached the front loader with a pallet fork. It is a side view of the tractor which attached the front loader with a bucket. It is a side view of the main frame of a front loader. It is a IIB-IIB arrow directional cross-sectional view of the main frame of FIG. 2A. It is a disassembled perspective view of a main frame. It is a side view of the main frame which uses an auto pin. FIG. 3B is a cross-sectional view taken along the line IIIB-IIIB in FIG. FIG. 3B is a cross-sectional view taken along line IIIB-IIIB in FIG. 3A showing the auto pin in the insertion standby state. It is a side view of the front loader with a bucket provided with the dump link mechanism of 2nd Embodiment of this invention. It is a side view of the front loader with a bucket provided with the dump link mechanism of 3rd Embodiment of this invention. It is a side view of the tractor equipped with the conventional front loader with a bucket. It is a conceptual diagram which shows the operation direction and operation content of an operation lever.

  Hereinafter, first to third embodiments of a front loader as a working machine having a dump link mechanism according to the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1A is a side view of a state in which a front loader 20 as a work machine is mounted on the front side of the tractor 10. The front loader 20 includes a pair of left and right lift cylinders 21, a pair of left and right lift arms 22 that are lifted and lowered by the lift cylinders 21, and a pair of left and right dump cylinders 25 disposed on the upper front side of the pair of left and right lift arms 22. And in this embodiment, the bucket 23 is attached to the front-end | tip of a pair of left and right lift arms 22 as an attachment.

  The front loader 20 of FIG. 1A is equipped with a hydraulic leveling mechanism and has a hydraulic system that sends oil on the return side of the lift cylinder 21 to the dump cylinder 25 on the tip side. The attachment such as the bucket 23 at the tip of the lift arm 22 is connected to the tip of the piston rod 25a of the dump cylinder 25 via a dump link mechanism 26 described later, and by the cooperative action of the hydraulic leveling mechanism and the dump link mechanism 26, Even when the lift arm 22 is moved up and down, the attachments such as the bucket 23 are kept horizontal.

  The front loader 20 has a pair of left and right main frames 27 on the base end side, and a base end portion of the lift arm 22 is connected to the front upper portion of the main frame 27 by pins 31. Further, a pair of upper and lower pin holes 32 and 33 are formed at the front lower portion of the main frame 27 as shown in FIG. 2A. These pin holes 32 and 33 are for inserting a pin 34 that supports the base end of the lift arm 22, and the upper pin hole 32 is for work in which the lifting height is given priority over the lifting force. The side pin hole 33 is for work in which the lifting force is prioritized over the lifting height. In FIG. 2A, the tip of the piston rod 21a of the lift cylinder 21 is supported by a pin 34 inserted into the lower pin hole 33 (priority in lifting force). In order to make it possible to finely adjust the priority of the lifting force or lifting height, in addition to the pair of upper and lower pin holes 32, 33, between the pin holes 32, 33 and above or below the pin holes 32, 33. It is also possible to additionally form one or more pin holes.

  On the other hand, fixed bases 10a integrated with the body frame of the tractor 10 are disposed on the front left and right sides of the tractor 10, and a pair of left and right main frames 27 of the front loader 20 are detachably attached to the fixed bases 10a by docking pins 38. It has been.

  A hydraulic control valve 39 for controlling the lift cylinder 21 and the dump cylinder 25 of the front loader 20 is attached to the upper side surface of the main frame 27 of the front loader 20. By the control operation of the hydraulic control valve 39, the lift arm 22 is lifted and lowered by the expansion and contraction of the lift cylinder 21, and the squeeze operation and dump operation by the expansion and contraction of the dump cylinder 25, the acceleration dump operation, and the force applied to the lift cylinder 22 A floating operation or the like in which the height of the head changes is performed.

  A pair of left and right intermediate plates 40 are disposed at intermediate positions in the longitudinal direction of the pair of left and right lift arms 22, and a body base portion of the lift cylinder 21 is supported by pins 41 on these intermediate plates 40. A main body base portion of the dump cylinder 25 is supported by a pin 42 on the tip side of the intermediate plate 40. The tip ends of the piston rods 25 a of these dump cylinders 25 extend to the tip end of the lift arm 22 and are connected to a bucket 23 as an attachment via a dump link mechanism 26.

  A pair of left and right stands 43 are attached to the lower side of the lift arm 22 on the front side of the intermediate plate 40. These stands 43 are for supporting the base end side of the front loader 20 by floating it from the ground in a state where the front loader 20 is separated from the tractor 10. One end of the stand 43 is connected to the lower side of the intermediate plate 40 with a pin 44. Has been. A grounding roller 45 is attached to the other end of the stand 43. When the front loader 20 is mounted on the tractor 10, the grounding roller 45 side of the stand 43 is engaged with the lower side of the lift arm 22, and the front loader 20 is In a state of being separated from the tractor 10, the stand 43 is rotated downward about the pin 44, and the grounding roller 45 is attached to the ground.

  As shown in FIG. 1A, the dump link mechanism 26 includes a pair of left and right connecting rods 26a, a crank 26b, and a snap hitch 26c. The connecting rod 26a and the crank 26b are formed by processing a steel plate into an arm having a predetermined length, and one end of each is connected to the tip of the piston rod 25a of the dump cylinder 25 by a common pin 49. The other end of the crank 26b is connected to the tip of the lift arm 22 by a pin 50, and when the dump cylinder 25 is expanded and contracted, the tip of the piston rod 25a is configured to draw an arc locus centering on the pin 50. Yes.

  The snap hitch 26c is formed by processing a steel plate into a vertically long predetermined shape so that the snap hitch 26c can be detachably engaged with the engaged portions on the left and right sides of the attachment such as the bucket 23. Attachment engaging portions 26c1 and 26c2 are formed at two front upper and lower portions of the snap hitch 26c, and the rear side is connected to the tip end portion of the lift arm 22 by a pin 51 so as to be swingable in the vertical direction.

  A feature of the dump link mechanism 26 of the present invention is that, as shown in FIG. 1A, two pin holes 26c3 and 26c4 are formed in the upper part of the snap hitch 26c. The other end of the connecting rod 26a is selectively connected to one of these two pin holes 26c3 and 26c4. When priority is given to lifting force such as transportation of vegetable containers and wrapping rolls, the pin 52 is inserted into the pin hole 26c3 and connected as shown in FIG. 1A, and priority is given to lifting height such as turning over compost, removing snow, and loading on a truck bed. In this case, the pin 52 is inserted into the pin hole 26c4 and connected as shown in FIG. 1C.

  When the pin 51 which is the pivot point of the snap hitch 26c is used as a reference, the pin hole 26c3 is arranged farther than the pin hole 26c4, and thus the lifting force (squeeze force) is increased accordingly. On the contrary, since the pin hole 26c4 is arranged closer to the pin 51 of the rotation fulcrum, the lifting height (squeeze angle) can be increased. In addition to the pin holes 26c3 and 26c4, one or more pin holes may be formed so that the priority of the lifting force or the lifting height can be adjusted more finely.

  Usually, when the lift cylinder 21 is connected to the lower pin hole 33 with priority on the lifting force, the dump link mechanism 26 also uses the pin hole 26c3 with priority on the lifting force. The dumping height is not necessarily lower than when the pin hole 26c4 that gives priority to the lifting height is used. For example, the dump angle θ2 (for example, about 74 degrees) that is too large at the ascending position as in the conventional case of FIG. 6 becomes the dump angle θ1 (for example, about 47 degrees) that is easy to use by selecting the pin hole 26c3 described above. As a result, the dump height increases from H2 (for example, 1850 mm) in FIG. 6 to H1 (for example, 1960 mm). As described above, even if the lifting force is prioritized, the lifting height may be increased, but there is no problem at all because the dump height may be lowered to the desired height by the operation lever 24.

FIG. 1B is an example in which the force-priority pin hole 26c3 is connected in the same manner as FIG. 1A. 1A except that the attachment is changed from the bucket 23 to the pallet fork 28.
FIG. 1C is an example in which the pin hole 26c4 is given priority to height, and the attachment is a bucket 23. Among the work contents using the bucket 23, the pin hole 26c4 having priority for height is used for turning back compost, removing snow, loading on a truck bed, and the like.

  As described above, the lift cylinder 21 can be selectively connected to the pin hole 32 with priority on lifting height and the pin hole 33 with priority on lifting force formed in the main frame 27. The main frame 27 is composed of a pair of left and right plates 27a and 27b as shown in FIG. 2B, and a pair of left and right guide portions 55a that comprehensively surround the pin holes 32 and 33 on the inner surfaces of the plates 27a and 27b facing each other. Is formed.

  As shown in FIG. 2C, the guide portion 55a is formed by a portion that is formed to protrude in the horizontal direction from the periphery of a vertically long oval plate material 55 fixed to the inner surfaces of the plates 27a and 27b. Both left and right end portions are guided by the vertically long straight portion of the guide portion 55a so as to move between the pin holes 32 and 33. The interval in the width direction of the vertically long portion of the guide portion 55a is substantially the same as the diameter of the boss portion 21b. The pin 34 to be inserted into the pin holes 32 and 33 of the main frame 27 and the boss hole 21c of the piston rod 21a has a handle 34a as shown in FIGS. 2B and 2C. The pins 34 are inserted into and removed from the boss holes 21c and the boss holes 21c.

  Since the guide portion 55a is formed so as to comprehensively surround the pin holes 32 and 33 as described above, when the lift cylinder 21 is expanded and contracted with the pin 34 pulled out, the boss portion of the piston rod 21a. 21b moves up and down along the guide portion 55a. That is, the guide portion 55a is inclined slightly clockwise (rightward) as shown in FIG. 2A with respect to a perpendicular perpendicular to the axis of the lift cylinder 21, and when the lift cylinder 21 is shortened, the piston rod 21a is pulled. 2b rises along the right guide portion 55a in FIG. 2A, and on the contrary, when the lift cylinder 21 is extended, the piston rod 21a is pushed out, so that the boss portion 21b becomes the left guide portion in FIG. 2A. Descends along 55a.

  The boss portion 21b comes into contact with the arc portion at the upper end or lower end of the guide portion 55a at its rising end or lowering end, and is positioned at a position where the boss hole 21c is aligned with the pin hole 32 or 33. Therefore, when changing the connecting position of the lift cylinder 21 in the vertical direction, it is not necessary to raise and lower the heavy lift cylinder 21 by hand to align the pin holes 32 and 33 and the boss hole 21c. Changing work is easy.

  Next, FIGS. 3A to 3C show an example in which a docking pin (auto pin) 58 with a stopper is used in place of the pin 34. The docking pin 58 is obtained by integrally connecting an L-shaped arm portion 58b to a pin main body 58a. A portion parallel to the pin main body 58a of the arm portion 58b penetrates the pair of plates 27a and 27b of the main frame 27 so as to be slidable and rotatable, and a compression spring 59 and a spring seat 60 are attached to the penetrating tip side. Yes.

  A stopper plate 62 is attached to the horizontal portion of the arm portion 58b. The stopper plate 62 can swing between the vertical and horizontal directions with the pin 61 as a center. The stopper plate 62 is rotated by hand, and the lower end thereof is pressed against the side surface of the plate 27a by the force of the compression spring 59 as shown in FIG. 3C so that the pin body 58a can be held at the standby position shown in FIG. 3C.

  The tip of the pin body 58a has a chamfered portion 58c. When the boss portion 21b of the piston rod 21a hits the chamfered portion 58c exposed to the inside of the plate 27a at the standby position, the pin main body 58a is temporarily pushed outward by the force to move, and the pin main body 58a. , The lower end of the stopper plate 62 is separated from the plate 27 a, and the stopper plate 62 rotates downward with its own weight around the pin 61. In this state, when the boss hole 21c of the tip boss portion 21b of the piston rod 21a comes into contact with the tip of the pin main body 58a, the pin main body 58a is automatically inserted into the boss hole 21c by the force of the compression spring 59 (just pin mechanism). .

  FIG. 3C shows a case where the boss portion 21 b is moved from the upper pin hole 32 to the lower pin hole 33, but there is also a case where the boss portion 21 b is moved from the lower pin hole 33 to the upper pin hole 32. It is the same. In this case, the pin main body 58a is rotated to the upper pin hole 32, and the lower end of the stopper plate 62 is placed on the plate 27a with the chamfered portion 58c at the tip thereof exposed to the inside of the plate 27a as in FIG. 3C. It is pressed against the side surface by the force of the compression spring 59. When such a so-called “just pin mechanism” of the docking pin 58 is used, the trouble of inserting the pin main body 58a into the boss hole 21c of the boss portion 21b can be saved, and the operation of changing the connecting position of the lift cylinder 21 is made easier. Become.

(Second Embodiment)
FIG. 4 shows a second embodiment of the present invention. Instead of providing two pin holes 26c3 and 26c4 in the snap hitch 26c, two pin holes 26b1 and 26b2 are formed in the crank 26b. In FIG. 4, the length of the crank is slightly extended from that of FIG. 1A, and the piston rod 25a of the dump cylinder 25 is connected to the exclusive pin hole 26b1 of this extended end by a pin 49, and the common side on the front side of the pin hole 26b1 is common. A connecting rod 26 a is connected to the pin hole 26 b 2 by a pin 53.

  FIG. 4 shows the connecting position with priority on the lifting force. When the lifting height has priority, the connection destination of the piston rod 25a of the dump cylinder 25 is changed by replacing the pin 49 from the dedicated pin hole 26b1 to the common pin hole 26b2. In addition to the pin holes 26b1 and 26b2, one or more pin holes may be formed so that the priority of the lifting force or lifting height can be adjusted more finely.

  Alternatively, the two pin holes 26b1 and 26b2 may be formed in the crank 26b while the two pin holes 26c3 and 26c4 of the snap hitch 26c are left as they are. By forming a plurality of pin holes in the snap hitch 26c and the crank 26b in this way, the number of combinations of connecting positions of the dump link mechanism 26 increases, and the work that can be handled by the front loader 20 can be increased.

(Third embodiment)
FIG. 5 shows a third embodiment of the present invention. Instead of providing two pin holes 26c3 and 26c4 in the snap hitch 26c, two pin holes 26a1 and 26a2 are formed in the connecting rod 26a. In FIG. 5, the length of the connecting rod 26a is slightly extended from that of FIG. 1A, and a pin hole 26a2 is added in the middle. The dedicated pin hole 26a1 at one end is connected to the piston rod 25a of the dump cylinder 25 by a pin 49, and the crank 26b is connected to the intermediate common pin hole 26a2 by a pin 54.

  FIG. 5 shows the connecting position with priority on the lifting force. When the lifting height has priority, the connecting destination of the piston rod 25a of the dump cylinder 25 is changed by replacing the pin 49 from the dedicated pin hole 26a1 to the common pin hole 26a2. In addition to the pin holes 26a1 and 26a2, one or more pin holes may be formed so that the priority of the lifting force or lifting height can be adjusted more finely.

  Further, the two pin holes 26a1 and 26a2 may be formed in the connecting rod 26a while the two pin holes 26c3 and 26c4 of the snap hitch 26c are left as they are. By forming a plurality of pin holes in the snap hitch 26c and the connecting rod 26a in this way, the number of combinations of connecting positions of the dump link mechanism 26 increases, and the work that can be handled by the front loader 20 can be increased.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, in the above-described embodiment, the dump link mechanism is configured by a snap hitch, a connecting rod, and a crank, but other members can be used alternatively or additionally, and the connecting position of the alternative part or the additional part can be selected in at least two positions. It may be. It is also possible to select dump link parts at three or more positions.

  Moreover, although the front loader 20 of the above embodiment is equipped with a hydraulic leveling mechanism, it may be equipped with a mechanical leveling mechanism using a parallel link instead of this hydraulic leveling mechanism.

  Further, in the embodiment, the connecting position of the lift cylinder 21 can be selected to the upper and lower two positions (pin holes 32, 33) on the main frame 27 side, but as shown in FIGS. 1 and 5, the pin on the intermediate plate 40 side 41 may be replaced with another pin hole 46 disposed slightly on the distal end side so that the base end portion of the lift cylinder 21 can be connected to the pin hole 46. When connected to the pin hole 46 on the distal end side, the connecting position is given priority to lifting force. Further, not only one pin hole 46 on the tip side but also a plurality of pin holes 46 may be arranged.

  Further, a guide portion 55a as shown in FIGS. 2A to 2C is formed between the position of the original pin 41 and the pin hole 46 as necessary, or docking as shown in FIGS. The pin 58 may be used.

DESCRIPTION OF SYMBOLS 10 Tractor 10a Fixing base 20 Front loader 21 Lift cylinder 22 Lift arm 23 Bucket 25 Dump cylinder 26 Dump link mechanism 26a Connecting rod 26b Crank 26c Snap hitch 27 Main frame 38 Docking pin 39 Hydraulic control valve 40 Intermediate plate 43 Stand 45 Grounding roller 55a Guide part 58 Docking pin

Claims (11)

  A lift arm that can be swung up and down by a lift cylinder, an attachment that is supported at the tip of the lift arm so as to be able to swing in the up and down direction, and attached to the lift arm to swing the attachment in the up and down direction And a dump link mechanism of a working machine comprising a dump link mechanism composed of a plurality of link members that transmit a force of the dump cylinder to the attachment, wherein any two of the link members A dump link mechanism characterized in that at least two coupling positions can be selected, and the dump angle of the attachment can be changed according to the selected positions.   The dump link member detachably engages with the attachment, a connecting rod that connects the snap hitch and the dump cylinder, and the force of the dump cylinder is transmitted to the attachment in cooperation with the connecting rod. The dump link mechanism according to claim 1, further comprising a crank.   The dump link mechanism according to claim 2, wherein the snap hitch has two pin holes for connecting to the connecting rod.   3. The dump link mechanism according to claim 2, wherein the crank has a dedicated pin hole for selectively connecting the dump cylinder alone, in addition to a common pin hole for connecting the connecting rod and the dump cylinder.   The dump link mechanism according to claim 2, wherein the connecting rod has a dedicated pin hole for selectively connecting the dump cylinder alone, in addition to a common pin hole for connecting the crank and the dump cylinder.   The dump link mechanism according to any one of claims 1 to 5, further comprising a hydraulic self-leveling mechanism.   The dump link mechanism according to any one of claims 1 to 5, further comprising a mechanical parallel link mechanism.   The dump link mechanism according to any one of claims 1 to 7, wherein a shaft hole for connecting one end of the lift cylinder is formed in at least two positions on a main frame of a work machine attached to the tractor.   The dump link mechanism according to any one of claims 1 to 7, wherein a shaft hole for connecting the other end of the lift cylinder is formed in at least two positions on an intermediate plate attached to an intermediate position in the longitudinal direction of the lift arm. .   The dump link mechanism according to claim 8 or 9, wherein a guide portion that guides an end portion of the lift cylinder is formed between the at least two shaft holes.   The dump link mechanism according to claim 10, wherein a docking pin with a stopper biased by a spring can be selectively inserted into the at least two shaft holes.

Images