JP2017106178A - Front loader and working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfy a requirement that a front loader which can constitute a connecting structure of an attachment frame and a boom compact in size, and a working vehicle are required.SOLUTION: A pair of left and right connecting parts 40 which are connected to a pivot shaft 16 are arranged at a bucket attachment frame 38, and an outside connecting plate 35 which is connected to a portion protruding to the outside laterally from a boom 11 out of the pivot shaft 16 in a state of being located at a lateral outer side of the boom 11, and an inside connecting part 36 which is connected to a portion protruding to the inside laterally from the boom 11 out of the pivot shaft 16 in a state of being located at a lateral inner side of the boom 11 are arranged at the connecting part 40. The outside connecting plate 35 is connected to a frame boss member 42 in a state of being located at a lateral inner side rather than a lateral outer side of the frame boss member 42.SELECTED DRAWING: Figure 10

Description

  The present invention includes a pair of left and right booms, a mounting frame that is swingably supported via a support shaft extending in the left-right direction at the free ends of the pair of left and right booms, and a work tool that is detachably attached to the mounting frame. And a work vehicle equipped with the same.

  As such a front loader, for example, a front loader described in Patent Document 1 is already known. The front loader described in Patent Literature 1 is swingably supported via a pair of left and right booms and a support shaft (a “horizontal axis” in the literature) extending in the left and right directions at the free ends of the pair of left and right booms. An attachment frame (in the literature, “mounting body”, “connecting portion”) and a work tool detachably attached to the attachment frame are provided.

  A pair of left and right locking mechanisms ("locking means" in the literature) that can be switched between a locked state for fixing the work tool to the mounting frame and a released state for releasing the locked state are provided on the back of the mounting frame. The locking mechanism includes a boss member ("cylinder guide" in the literature) that extends in the vertical direction along the back surface of the mounting frame in a state that is positioned laterally outside the lateral outer end of the boom, and a lock position that corresponds to the locked state. A shaft member ("lock pin" in the literature) that is slidably supported by the boss member over a release position corresponding to the release state is provided.

  The mounting frame is provided with a pair of left and right connecting portions connected to the support shaft. The connecting portion is located on the lateral inner side of the boom, and is connected to an outer coupling body (“bracket” in the literature) that is coupled to a portion of the support shaft that projects laterally outward from the boom while being located on the lateral outer side of the boom. And an inner coupling body (“bracket” in the literature) that is coupled to a portion of the support shaft that projects laterally inward from the boom.

JP 2014-5690 A

  In the front loader described in Patent Document 1, the outer coupling body is located laterally outside the boss member. For this reason, the space | interval of the left-right direction of an outer side coupling body and an inner side coupling body becomes large, the length of a spindle becomes long, or the part (for example, boss | hub part) in the outer side coupling body and an inner coupling body ) Becomes longer. As a result, the connecting structure between the mounting frame and the boom is enlarged, resulting in an increase in cost.

  In view of the above situation, there is a demand for a front loader and a work vehicle that can compactly form a connection structure between a mounting frame and a boom.

The features of the present invention are:
A pair of left and right booms;
An attachment frame that is swingably supported via a support shaft extending in the left-right direction at the free ends of the pair of left and right booms;
A work tool detachably attached to the mounting frame;
A pair of left and right locking mechanisms provided on the back of the mounting frame and capable of switching between a locked state for fixing the work tool to the mounting frame and a released state for releasing the locked state;
Corresponding to the lock mechanism, the boss member extending in the vertical direction along the back surface of the mounting frame in a state positioned laterally outside the lateral outer end of the boom, the lock position corresponding to the lock state, and the release state A shaft member that is slidably supported by the boss member over a release position to be
The mounting frame is provided with a pair of left and right connecting portions connected to the support shaft,
An outer connecting body connected to the connecting portion to a portion of the support shaft that protrudes laterally outward from the boom in a state of being located laterally outside the boom, and in a state of being located laterally inside the boom An inner coupling body coupled to a portion of the support shaft that projects laterally inward from the boom, and
The said outside coupling body exists in being connected with the said boss member in the state located in a horizontal inner side rather than the horizontal outer end of the said boss member.

  According to this characteristic configuration, the outer coupling body is coupled to the boss member in a state of being located laterally inner than the lateral outer end of the boss member, and therefore, the outer coupling body is positioned laterally outer than the boss member. In comparison, the distance between the outer connecting body and the inner connecting body in the left-right direction is reduced, and the length of the support shaft and the length of the outer connection body and the portion that supports the support shaft in the inner connection body (for example, the boss portion) Shorter. Thereby, while being able to comprise the connection structure of an attachment frame and a boom compactly, the strength of a spindle and a boss | hub part can be aimed at. Moreover, an outer coupling body will be supported by the highly rigid boss member, and an outer coupling body can be supported firmly.

Furthermore, in the present invention,
It is preferable that the outer coupling body is located laterally inner than the axis of the boss member.

  According to this characteristic configuration, the distance between the outer connecting body and the inner connecting body in the left-right direction is further reduced, and the length of the support shaft and the length of the boss portion can be further shortened.

Furthermore, in the present invention,
The mounting frame includes a frame main body to which the boss member is attached,
The outer coupling body is preferably coupled to the boss member and the frame body.

  According to this characteristic configuration, the connecting portion is supported by both the boss member and the frame body, so that the connecting portion can be supported more firmly.

Furthermore, in the present invention,
The front loader is preferably provided in a work vehicle.

  According to this characteristic configuration, in the work vehicle including the front loader, the connection structure between the mounting frame and the boom can be configured in a compact manner.

It is a right view which shows a tractor. It is a top view which shows the front part of a tractor. It is right side sectional drawing which shows the front loader of the state with which the body was mounted | worn. It is right side sectional drawing which shows the front loader of the state supported by the stand. It is a right side sectional view showing the front loader in a state where the boom is raised and the bucket is dumped to the position where it comes into contact with the stand. It is a right side sectional view showing the front loader in a state where the bucket is dumped to the maximum dump position. It is right side sectional drawing which shows the front loader of the state which accommodated the stand. It is a right view which shows an interlocking mechanism. It is a rear view which shows the state in which the bucket was attached to the attachment frame. It is a rear view which shows a locking mechanism and a connection part. It is right side sectional drawing which shows a locking mechanism and a connection part. It is sectional drawing which shows a locking mechanism and a connection part. It is a disassembled perspective view which shows a mounting mechanism. It is right side sectional drawing which shows the internal structure of a side frame. It is a rear view which shows a lever guide. It is a back sectional view showing the attachment structure of a pin. It is right side sectional drawing which shows the front loader of the state in which the pin was engage | inserted by the recessed part. It is an expansion right side sectional view showing the state where the pin was inserted in the crevice. It is an expansion right side sectional view showing the state where a hook engaged with a boss part.

  EMBODIMENT OF THE INVENTION The form for implementing this invention is demonstrated based on drawing. In the following description, the direction of the arrow F shown in FIGS. 1 and 2 is “front side”, the direction of arrow B is “rear side”, the direction of arrow L shown in FIG. The direction of R is the “airframe right side”.

[Overall structure of tractor]
1 and 2 show a tractor (corresponding to a “work vehicle” according to the present invention) including a front loader 3 with a stand 18. The tractor includes a body frame 1 and a wheel-type traveling device 2 that supports the body frame 1. The traveling device 2 includes a pair of left and right front wheels 2F and a pair of left and right rear wheels 2B.

  A front loader 3 is provided in front of the airframe. The front loader 3 is detachably attached to the machine body. A mounting frame 1 </ b> A to which the front loader 3 can be attached is provided on each of the left side and the right side of the body frame 1. The mounting frame 1 </ b> A is provided at the machine body lateral outer end portion of the connection pipe 1 </ b> B projecting from the machine frame 1 to the machine body laterally outward. A bonnet 4 is provided in the front half of the body frame 1. An engine (not shown) is accommodated in the bonnet 4.

  In the latter half of the machine body frame 1, an operation unit 5 on which an operator gets on is provided. The driver 5 is provided with a driver seat 6 and a front panel 7. A steering handle 9 is provided on the front panel 7.

[Front loader]
The front loader 3 is provided with a pair of left and right booms 11, a pair of left and right side frames 12, and a bucket 13 (corresponding to a “work tool” according to the present invention). The pair of left and right booms 11 extend from the left and right sides of the bonnet 4 to positions in front of the aircraft. The pair of left and right booms 11 are connected by a connection pipe 14 extending in the left-right direction of the machine body. The boom 11 is supported at the upper end of the side frame 12 so as to be swingable around a swing axis X1 extending in the left-right direction of the machine body. A hydraulic cylinder 15 that swings and drives the boom 11 is provided across the boom 11 and the side frame 12.

  The side frame 12 is detachably attached to the attachment frame 1A. The end of the hydraulic cylinder 15 on the rod 15 </ b> A side is supported on the side frame 12 via a mount pin 33. The side frame 12 is provided with a pair of left and right side plates 12A.

  The bucket 13 is supported at the free end of the boom 11 via a support shaft 16 so as to be swingable about a swing axis X2 extending in the left-right direction of the machine body. Each of the left end portion and the right end portion of the back portion of the bucket 13 includes an outer connecting plate 35 (corresponding to an “outer connecting body” according to the present invention) connected to the support shaft 16 and an inner connecting plate 36 (“ Corresponding to “inner connecting body”). The outer connecting plate 35 and the inner connecting plate 36 sandwich the free end portion of the boom 11 from both the left and right sides. A hydraulic cylinder 17 that swings and drives the bucket 13 is provided across the bucket 13 and the connection pipe 14.

〔stand〕
As shown in FIGS. 2 and 3, the tractor is provided with a stand 18 that supports the front loader 3 so that the front loader 3 is self-supporting when the front loader 3 is attached and detached. The stand 18 swings around the swing axis X2 on the support shaft 16 over the use posture (see FIG. 4) for supporting the front loader 3 and the storage posture (see FIG. 3) along the longitudinal direction of the boom 11. Supported as possible. That is, the swing axis X2 of the bucket 13 and the swing axis X2 of the stand 18 are set on the same axis.

  The stand 18 is provided with a pair of left and right stand bodies 19. The pair of left and right stand bodies 19 are connected by a connection frame 20 extending in the left-right direction of the machine body so as to swing in conjunction with each other. The pair of left and right stand bodies 19 are located on the inner side of the left boom 11 and the right boom 11 respectively. The stand 18 does not necessarily have to be on the same axis as the bucket 13, but by using the same axis, it is not only necessary to provide a separate rotating shaft part, but also by using an axis having sufficient strength. The stand 18 can be made stronger.

  In the left-right direction of the machine body, the stand body 19 is arranged at the intermediate portion in the longitudinal direction so that the distance between the free ends of the pair of left and right stand bodies 19 is longer than the distance between the base end portions of the pair of left and right stand bodies 19 The free end portion is bent so that the free end portion side is located on the laterally outer side with respect to the base end portion side. The free end of the stand body 19 overlaps the boom 11 in plan view (see FIG. 2). A wide-width grounding portion 19 a is formed at the free end portion of the stand body 19. According to such a configuration, the front loader 3 can be firmly supported by the stand 18 without wobbling in the left-right direction of the machine body.

[Link mechanism]
A link mechanism 21 is provided across the boom 11 and the stand body 19. The link mechanism 21 is located between the boom 11 and the stand body 19 in the left-right direction of the machine body. The link mechanism 21 includes a first link member 22 on the boom 11 side and a second link member 23 on the stand body 19 side. The first link member 22 and the second link member 23 are connected to each other via a connecting shaft 24 so as to be relatively swingable. A long hole 23 a through which the connecting shaft 24 is inserted is formed at the end of the second link member 23 on the first link member 22 side.

[Stand lock mechanism]
A stand lock mechanism 25 is provided that can be switched between a locked state in which the stand 18 is held in the storage position and a released state in which the locked state is released. In the present embodiment, the stand lock mechanism 25 is provided across the left stand body 19 and the left boom 11. The stand lock mechanism 25 includes a pin 26 and a hook 27 that can be engaged with the pin 26. The pin 26 is provided at a free end portion of the left stand body 19 so as to protrude inwardly from the aircraft body. The hook 27 swings on the side of the left side boom 11 on the inner side of the body, extending in the left-right direction of the body over an engagement position where the pin 26 is engaged and a non-engagement position where the pin 26 is not engaged. It is supported so as to be swingable about the axis X3. The hook 27 is located in the middle in the longitudinal direction of the left boom 11. Specifically, the hook 27 is located between the location where the hydraulic cylinder 15 is connected and the location where the connection pipe 14 is connected in the left boom 11.

[Stand control lever]
A stand operation lever 28 that is configured to be manually operable from the operation unit 5 and that switches the stand lock mechanism 25 between a locked state and a released state is provided. The stand operation lever 28 can be switched between a lock position corresponding to the engagement position of the hook 27 and a release position corresponding to the non-engagement position of the hook 27, and can be held at the lock position and the release position, respectively. is there. The stand operating lever 28 is supported on the side of the left side boom 11 on the laterally inner side of the body so as to be swingable about a swing axis X4 extending in the left-right direction of the body. The stand operation lever 28 is located at the free end of the left boom 11. Specifically, the stand operation lever 28 is positioned above the front wheel 2F on the rear side of the rotational axis of the front wheel 2F.

[Interlocking mechanism]
An interlocking mechanism 29 that interlocks and links the stand lock mechanism 25 and the stand operation lever 28 is provided. The interlocking mechanism 29 is located inside the fuselage side of the left boom 11. The interlock mechanism 29 includes a first arm 30 on the stand operation lever 28 side, a second arm 31 on the hook 27 side, and a linkage rod 32 that extends between the first arm 30 and the second arm 31. . The first arm 30 can swing integrally with the stand operation lever 28. The second arm 31 can swing integrally with the hook 27.

[Switching stand posture]
As shown in FIG. 4, in a state where the front loader 3 is not attached to the airframe, the stand 18 is switched to the use posture in order to make the front loader 3 self-supporting. And while advancing a body, the body side and the front loader 3 side are connected by the hydraulic hose (illustration omitted), and the front loader 3 can be mounted to the mounting frame 1A. The tractor is provided with a pair of left and right attachment mechanisms 55 for attaching the front loader 3 to the airframe, which will be described in detail later.

  Here, an abutting portion 22 a that can abut on the second link member 23 is provided at an end of the first link member 22 on the second link member 23 side. When the stand 18 is in the use posture, the contact portion 22a contacts the second link member 23, thereby preventing the second link member 23 from swinging toward the opening side (in the direction of arrow A shown in FIG. 4). Yes. That is, the link mechanism 21 prevents the stand 18 from swinging toward the storage posture when the stand 18 is in the use posture. In the state shown in FIG. 4, the first link member 22 and the second link member 23 are opened so that the opening degree α is slightly larger than 180 degrees.

  Subsequently, as shown in FIG. 5, the boom 11 is raised and the bucket 13 is dumped to a position where it comes into contact with the stand 18.

  More specifically, the inner connecting plate 36 is provided with a protrusion 37 projecting inwardly from the airframe at each of the left end portion and the right end portion of the back portion of the bucket 13. On the other hand, a recess 19 b into which the protrusion 37 enters is formed at the base end of the stand body 19. As a result, the boom 11 is raised, and the bucket 13 is dumped to a position where the protrusion 37 enters the recess 19b and contacts the base end of the stand body 19. In the present embodiment, by providing the recess 19 b in the stand body 19, it is easy to adjust the swing range of the stand body 19 adapted to the dumping operation of the bucket 13.

  Then, when the bucket 13 is further dumped in a state where the projection 37 is in contact with the base end portion of the stand body 19, the stand 18 is retracted in conjunction with the dumping operation of the bucket 13 as shown in FIG. Is swung to the side.

  Here, when the bucket 13 is dumped in the state shown in FIG. 5, the length of the link mechanism 21 is shortened by the amount that the second link member 23 moves along the connecting shaft 24 through the long hole 23a. Thus, the second link member 23 swings toward the closing side (the direction opposite to the arrow A shown in FIG. 4). That is, the link mechanism 21 allows the stand 18 to swing to the storage posture side in conjunction with the dumping operation of the bucket 13. When the bucket 13 is dumped to the maximum dump position, the stand 18 is in the state shown in FIG.

  Next, as shown in FIG. 7, when the stand operation lever 28 is switched to the locked position, the hook 27 is interlocked with the stand operation lever 28 via the interlock mechanism 29. Thereby, the hook 27 is switched to the engagement position.

  At that time, as shown in FIG. 8, as the hook 27 is switched to the engagement position, the stand 18 is slightly lifted by the hook 27 via the pin 26 to a position corresponding to the storage posture. As a result, there is a slight gap between the protrusion 37 and the base end of the stand body 19, and when the stand 18 is in the stowed position, the protrusion 37 and the stand body 19 come into contact with each other during work. It becomes difficult. In this way, the stand 18 is held in the stowed position when the stand lock mechanism 25 is switched to the locked state by the stand operation lever 28.

  Further, the stand 18 can be switched to the use posture by a procedure opposite to the above. That is, as shown in FIG. 7, when the stand operating lever 28 is switched to the release position while the stand 18 is held in the storage position by the stand lock mechanism 25, the stand lock mechanism 25 is switched to the release state (see FIG. 6). ). As a result, the stand 18 slightly moves downward to a position where the base end portion of the stand body 19 abuts on the protrusion 37.

  When the bucket 13 is moved in a scooping manner, the stand 18 is swung to the use posture side in conjunction with the scooping operation of the bucket 13 in a state where the protrusion 37 is in contact with the proximal end portion of the stand body 19. In this way, the stand 18 can be switched to the use posture.

[Bucket mounting frame]
As shown in FIG. 9, at the free ends of the pair of left and right booms 11, a bucket mounting frame 38 (corresponding to the “mounting frame” according to the present invention) is a swing shaft that extends in the left-right direction of the machine body via a support shaft 16. It is supported so as to be able to swing around the center X2. A boss portion 11 a through which the support shaft 16 is inserted is provided at the free end portion of the boom 11. The bucket 13 is detachably attached to the bucket attachment frame 38. The bucket mounting frame 38 is provided with a pair of left and right frame bodies 39 and a pair of left and right connecting portions 40.

[Bucket lock mechanism]
A pair of left and right bucket lock mechanisms 41 (a “lock mechanism” according to the present invention) that can be switched between a locked state in which the bucket 13 is fixed to the bucket mounting frame 38 and a released state in which the locked state is released are placed on the back of the frame body 39. Equivalent). The bucket lock mechanism 41 includes a frame boss member 42 (corresponding to the “boss member” according to the present invention), a bucket lock pin 43 (corresponding to the “shaft member” according to the present invention), and an operation handle 44. It has been.

(Frame boss member)
As shown in FIGS. 10 to 12, the frame boss member 42 extends in the vertical direction along the rear surface of the frame body 39 in a state of being located on the laterally outer side of the body with respect to the laterally outer end of the body of the boom 11 (boss portion 11 a). ing. The frame boss member 42 is fixed to the frame body 39 by welding.

[Bucket lock pin]
The bucket lock pin 43 is attached to the frame boss member 42 over a lock position (position indicated by a solid line in FIG. 10) corresponding to the locked state and a release position (position indicated by a two-dot chain line in FIG. 10) corresponding to the released state. It is slidably supported. The frame body 39 and the bucket 13 are formed with lock holes 39a, 13a, and 13b through which the bucket lock pin 43 can be inserted.

  A link 45 is swingably connected to the upper end of the bucket lock pin 43. A stopper 46 is slidably supported on the link 45. A spring 47 is fitted on a portion of the link 45 between the receiving portion 45 a and the stopper 46.

[Operation handle]
The operation handle 44 is supported by a support shaft 39b on the frame body 39 side so as to be swingable around the swing axis Y1. One end of the operation handle 44 is bolted to the stopper 46. A handle 44 a is formed at the other end of the operation handle 44.

[Frame body]
The frame main body 39 has a main body portion 39A extending in the vertical direction along the back surface of the bucket 13; an upper mounting portion 39B formed at the upper end portion of the frame main body 39 and to which the upper portion of the back portion of the bucket 13 is attached; And a lower mounting portion 39 </ b> C to which a lower portion of the back portion of the bucket 13 is attached. A vertical plate 48 extending in the vertical direction across the upper mounting portion 39B and the lower mounting portion 39C is welded and fixed to the frame body 39. The vertical plate 48 is located on the laterally outer side of the body with respect to the frame boss member 42.

(Connecting part)
The connecting portion 40 is provided with an outer connecting plate 35 and an inner connecting plate 36. A stopper 51 capable of contacting the stopper 50 on the boom 11 side is provided across the outer connecting plate 35 and the inner connecting plate 36. During the dumping operation of the bucket 13, the stopper 51 on the connecting portion 40 side comes into contact with the stopper 50 on the boom 11 side, so that the bucket 13 is positioned at the most dump position.

  The outer connecting plate 35 is connected to a portion of the support shaft 16 that protrudes laterally outward from the boom 11 (the boss portion 11a) in a state of being located on the laterally outer side of the boom 11. The outer connecting plate 35 is welded and fixed to the frame boss member 42 and the lower mounting portion 39 </ b> C in a state of being located on the inner side of the body side of the body side of the frame boss member 42. Specifically, the outer connecting plate 35 is located on the inner side of the fuselage with respect to the axis Z1 of the frame boss member 42 and on the outer side of the fuselage with respect to the inner side of the frame boss member 42. That is, the outer connecting plate 35 overlaps with the frame boss member 42 in the rear view (see FIG. 10).

  The length of the outer connecting plate 35 in the vertical direction is shorter than the length of the inner connecting plate 36 in the vertical direction. The upper end position of the outer connecting plate 35 is set below the upper end position of the frame boss member 42.

  The inner connecting plate 36 is connected to a portion of the support shaft 16 that protrudes inwardly from the boom 11 (the boss portion 11 a) in a state of being located on the inner side of the boom 11. The inner connecting plate 36 is welded and fixed to the main body portion 39A and the lower mounting portion 39C. The inner connecting plate 36 is provided with a boss portion 36 a that supports the support shaft 16. The boss portion 36 a protrudes from the inner connecting plate 36 inward of the machine body.

  The left inner connecting plate 36 and the right inner connecting plate 36 are connected by two horizontal frames 52 extending in the left-right direction of the machine body. A support bracket 53 is provided across one horizontal frame 52 and the other horizontal frame 52. The end of the hydraulic cylinder 17 on the rod 17 </ b> A side is supported by the support bracket 53 via a pin 54.

  According to such a configuration, the outer connecting plate 35 is connected to the frame boss member 42 in a state of being located on the inner side of the body side of the frame boss member 42 with respect to the outer side of the body side of the body of the frame boss member 42. Compared with the case where the member 42 is located on the laterally outer side of the machine body, the distance between the outer connecting plate 35 and the inner connecting plate 36 in the left-right direction of the machine body is reduced, so that the length of the support shaft 16 and the outer connecting plate 35 and inner connecting plate are reduced. The length of the portion (for example, the boss portion 36a) that supports the support shaft 16 is shortened. Thereby, the connection structure between the bucket mounting frame 38 and the boom 11 can be configured in a compact manner, and the strength of the support shaft 16 and the boss portion 36a can be increased. In addition, the outer connecting plate 35 is supported by the frame boss member 42 having high rigidity, so that the outer connecting plate 35 can be firmly supported.

[Change bucket lock mechanism]
As shown in FIG. 10, when the operation handle 44 is swung to the position shown by the solid line in FIG. 10, the bucket lock pin 43 moves downward along the frame boss member 42, and the lock hole 39a on the frame main body 39 side. The lock holes 13a and 13b on the bucket 13 side are inserted. At this time, the first contact portion 44b of the operation handle 44 contacts the vertical plate 48, so that the operation handle 44 does not swing any further. The operation handle 44 is held in a state in which the first contact portion 44 b is in contact with the vertical plate 48 by the biasing force of the spring 47. Thus, the bucket lock mechanism 41 can be switched to the locked state.

  When the operation handle 44 is swung to the position indicated by the two-dot chain line in FIG. 10, the bucket lock pin 43 swings upward along the frame boss member 42, and the lock hole 39a on the frame body 39 side, the bucket The lock holes 13a and 13b on the 13th side come out. At this time, the second abutment portion 44 c of the operation handle 44 abuts on the vertical plate 48, so that the operation handle 44 does not swing any further. Thus, the bucket lock mechanism 41 can be switched to the released state.

[Mounting mechanism for front loader]
As shown in FIGS. 13 and 14, the attachment mechanism 55 includes an attachment frame boss portion 56 provided on the attachment frame 1 </ b> A, and a hook 57 provided on the side frame 12 and engageable with the attachment frame boss portion 56. And a stopper 58 provided on the side frame 12 and capable of supporting the mounting frame boss portion 56.

[Mounting frame boss]
The mounting frame boss portion 56 is provided at the upper end portion of the mounting frame 1A so as to penetrate the mounting frame 1A in the left-right direction of the body. The left end portion and the right end portion of the attachment frame boss portion 56 protrude leftward and rightward from the attachment frame 1A, respectively.

〔hook〕
The hook 57 engages with the attachment frame boss portion 56 (a position indicated by a solid line in FIG. 14) and a non-engagement position not engaged with the attachment frame boss portion 56 (a position indicated by a two-dot chain line in FIG. 14). And can be switched. The hook 57 is supported by the side frame 12 via the mount pin 33 so as to be swingable around a swing axis X5 extending in the left-right direction of the body. The hook 57 is accommodated inside the side frame 12. Specifically, the hook 57 is disposed between the pair of left and right side plates 12A.

  The hook 57 is provided with a pair of left and right hook bodies 57A. The pair of left and right hook bodies 57A are connected by connecting bodies 61 and 62 so as to swing in conjunction with each other. The pair of left and right hook bodies 57A are located on the left and right sides of the end of the hydraulic cylinder 15 on the rod 15A side, respectively. The left hook body 57A can engage with a portion of the attachment frame boss portion 56 that protrudes leftward from the attachment frame 1A. The right hook body 57A is engageable with a portion of the attachment frame boss portion 56 that protrudes leftward from the attachment frame 1A.

〔stopper〕
The stopper 58 is provided with a pair of left and right stopper bodies 58A. The pair of left and right stopper bodies 58A are fixed by welding to the inner surfaces of the pair of left and right side plates 12A. The stopper 58 is connected to a pin 59 provided at the lower end of the side frame 12 by a connection plate 60.

  The stopper body 58A has a receiving portion 58a that receives and supports the mounting frame boss portion 56, and an inlet portion 58b that is formed on the opposite side (front end side) of the stopper body 58A to the receiving portion 58a and receives the mounting frame boss portion 56. And are provided. The receiving portion 58 a is formed with an arc-shaped recess 58 c that follows the outer peripheral shape of the mounting frame boss portion 56. The inlet portion 58b is tapered so that the distance between the pair of left and right stopper bodies 58A increases as it approaches the tip. Thereby, a front opening (a space between the pair of left and right stopper bodies 58A) in which the pair of left and right stopper bodies 58A receive the mounting frame boss portion 56 is widened.

[Hook control lever]
A hook operation lever 63 that is configured to be manually operable from the operation unit 5 and that switches the hook 57 between an engagement position and a non-engagement position is provided. The hook operation lever 63 is configured by a plate member that can be elastically deformed. The hook operation lever 63 is coupled to the connection body 62. The hook operation lever 63 is housed inside the side frame 12. Specifically, the hook operation lever 63 is disposed between the pair of left and right side plates 12A.

  As shown in FIG. 15, the side frame 12 is provided with a lever guide 64 for the hook operation lever 63. The lever guide 64 is configured by a plate member that is appropriately bent. The lever guide 64 is formed with a guide groove 64 </ b> A for guiding the hook operation lever 63. The guide groove 64A has an engagement positioning portion 64a for positioning the hook operation lever 63 at an engagement operation position corresponding to the engagement position of the hook 57, and a non-engagement position corresponding to the non-engagement position of the hook 57. A non-engagement positioning part 64b for positioning at the engagement operation position and an oblique guide part 64c extending between the engagement positioning part 64a and the non-engagement positioning part 64b are provided. The non-engaging positioning portion 64b is provided with a holding portion 64d that hooks the hook operation lever 63 and holds it at the non-engaging operation position.

[Mount pin mounting structure]
As shown in FIG. 16, a fixing plate 65 is welded and fixed to a portion of the mount pin 33 that protrudes laterally outward from the side frame 12. The fixing plate 65 is fixed to the fixed plate 66 on the side frame 12 side by a bolt 67, so that the mount pin 33 is prevented from rotating and coming off.

  The fixed plate 66 is formed with an insertion hole 66a through which the mount pin 33 is inserted. A chamfered portion 66b is formed in a portion of the fixed plate 66 corresponding to the end portion of the insertion hole 66a on the outer side of the machine body. The chamfered portion 66b accommodates an O-ring 68 that is externally fitted to the mount pin 33. As a result, even if the grease lubricated from the grease nipple 70 provided at the end on the rod 15A side of the hydraulic cylinder 15 leaks out from between the mount pin 33 and the fixed plate 66 to the outer side of the machine body, The O-ring 68 can prevent the grease from leaking out.

[Installation of front loader]
As shown in FIG. 17, the bucket 13 is dumped from the state where the front loader 3 is supported by the stand 18 (the state shown in FIG. 4), and the pin 59 on the side frame 12 side is inserted into the recess 69 on the mounting frame 1A side. Fit into. Then, as shown in FIG. 18, the mounting frame boss 56 is positioned at the inlet 58b of the stopper 58 and comes into contact with the hook 57, so that the hook 57 swings from the engaged position to the non-engaged position. At the same time, the hook operating lever 63 swings to an intermediate position on the oblique guide portion 64c in the guide groove 64A while being elastically deformed.

  Then, as shown in FIG. 19, when the side frame 12 is set to a vertical posture, the hook 57 is engaged with the attachment frame boss portion 56. More specifically, the mounting frame boss 56 is fitted into the recess 58c of the stopper 58 and received and supported by the receiving portion 58a, and the mounting frame boss 56 is received and supported by the receiving portion 58a of the stopper 58. The hook 57 engages with the attachment frame boss portion 56. At this time, the hook operation lever 63 swings toward the engagement operation position side along the oblique guide portion 64c in the guide groove 64A while restoring the original shape, and is positioned at the engagement operation position. Thus, the front loader 3 can be mounted on the machine body by the hook 57 engaging with the attachment frame boss portion 56.

  Further, in order to remove the front loader 3 from the airframe, the hook operation lever 63 is switched from the operating portion 5 to the disengagement operation position, and the hook operation lever 63 is hooked on the holding portion 64d in the guide groove 64A to perform the disengagement operation. Hold in position. As a result, the hook 57 is switched to the non-engagement position, and the front loader 3 can be removed from the machine body.

  According to such a configuration, the front loader 3 can be easily mounted on the machine body by merely engaging the hook 57 with the attachment frame boss portion 56. That is, the front loader 3 can be attached to the machine body without using pins or bolts, and the front loader 3 can be easily attached to and detached from the machine body.

[Another embodiment]
(1) In the above embodiment, the outer connecting plate 35 is located on the inner side of the machine body from the axis Z1 of the frame boss member 42 and on the outer side of the machine body from the inner side edge of the machine body side of the frame boss member 42. The present invention is not limited to this. For example, the outer connecting plate 35 may be located on the outer side of the machine body from the axis Z1 of the frame boss member 42 and on the inner side of the machine body from the outer side of the machine body side of the frame boss member 42. It may be located at the axial center Z1 of the boss member 42, or may be located on the inner side of the body side of the body side of the frame boss member 42.

(2) In the above embodiment, the outer connecting plate 35 is welded and fixed to the frame boss member 42 and the lower mounting portion 39C, but may be fixed to the frame boss member 42 only by welding. Note that the method of connecting the outer connecting plate 35 to the frame boss member 42 or the like is not limited to welding fixation.

(3) In the above embodiment, the “work tool” according to the present invention is configured by the bucket 13, but the “work tool” is not limited to the bucket 13.

  INDUSTRIAL APPLICABILITY The present invention can be used for a work vehicle having a cabin as well as a work vehicle having no cabin.

3 Front loader 11 Boom 13 Bucket (work implement)
16 Support shaft 35 Outer coupling plate (outer coupling body)
36 Inner connection plate (inner connection body)
38 Bucket mounting frame (mounting frame)
39 Frame body 40 Connecting portion 41 Bucket lock mechanism (lock mechanism)
42 Frame boss member (boss member)
43 Bucket lock pin (shaft member)
Z1 Boss member axis

Claims (4)

A pair of left and right booms;
An attachment frame that is swingably supported via a support shaft extending in the left-right direction at the free ends of the pair of left and right booms;
A work tool detachably attached to the mounting frame;
A pair of left and right locking mechanisms provided on the back of the mounting frame and capable of switching between a locked state for fixing the work tool to the mounting frame and a released state for releasing the locked state;
Corresponding to the lock mechanism, the boss member extending in the vertical direction along the back surface of the mounting frame in a state positioned laterally outside the lateral outer end of the boom, the lock position corresponding to the lock state, and the release state A shaft member that is slidably supported by the boss member over a release position to be
The mounting frame is provided with a pair of left and right connecting portions connected to the support shaft,
An outer connecting body connected to the connecting portion to a portion of the support shaft that protrudes laterally outward from the boom in a state of being located laterally outside the boom, and in a state of being located laterally inside the boom An inner coupling body coupled to a portion of the support shaft that projects laterally inward from the boom, and
The outer loader is a front loader coupled to the boss member in a state of being located laterally inner than the lateral outer end of the boss member.   The front loader according to claim 1, wherein the outer coupling body is located laterally inner than the axis of the boss member. The mounting frame includes a frame main body to which the boss member is attached,
The front loader according to claim 1, wherein the outer coupling body is coupled to the boss member and the frame body.   A work vehicle provided with the front loader according to any one of claims 1 to 3.

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