JP2020100497A - Jib extending device and construction machine - Google Patents

Abstract

To provide a jib extending device that enables a tension rod to be easily and safely connected to and disconnected from a boom head.SOLUTION: A jib extending device comprises a boom, a jib, a tension rod, and a boom-side link. The boom can be lowered to have an angle of depression with respect to a horizontal direction. The jib can be coupled to the front end of the boom. The jib can be rotated around the position where it is coupled to the front end of the boom and can be disposed on the underside of the boom, in the lengthwise direction of the boom. One end of the tension rod is connected to the jib, and one end of the boom-side link can be connected to the other end of the tension rod. The other end of the boom-side link is connected to the front end of the boom on a side closer to the upper side of the boom with respect to the coupled position of the jib. The boom-side link is rotatable around the position where it is connected to the front end of the boom.SELECTED DRAWING: Figure 1

Description

The present invention relates to a jib overhanging device and a construction machine including the jib overhanging device.

Patent Document 1 discloses a crane equipped with a jib overhanging device. In this jib overhanging device for a crane, a jib is provided together with a boom that can be raised and lowered. When the jib is not used, the jib is arranged on the bottom surface of the boom along the longitudinal direction of the boom. When using the jib, connect the jib to the boom head provided at the front end of the boom, and disconnect the jib from the boom other than the boom head. As a result, the jib can rotate with respect to the boom about the connecting position to the boom head. Further, the jib overhanging device is provided with a tension rod whose one end (front end) is connected to the jib. When using the jib, connect the other end (rear end) of the tension rod to the boom head and stretch the tension rod between the boom head and the jib. Then, when the jib is used, the jib is rotated about the connecting position to the boom head in a state where the jib is extended to the front side of the boom with respect to the state where the jib hangs from the boom head. This causes the jib to rise or lie against the boom.

JP-A-5-116888

In the construction machine provided with the jib overhanging device of Patent Document 1 or the like, it is necessary to connect the tension rod to the front end portion of the boom such as the boom head when the jib is used. Further, when the jib is stored after the use of the jib, it is necessary to disconnect the tension rod from the front end of the boom. The jib overhanging device is required to easily and safely connect and disconnect the tension rod to the front end of the boom.

The present invention has been made to solve the above problems, and an object thereof is to connect and disconnect a tension rod to a front end portion of a boom easily and safely, and a jib overhanging device. It is to provide a construction machine provided with the jib overhanging device.

In order to achieve the above-mentioned object, a jib overhanging device of an aspect of the present invention is a boom that has a boom upper surface and a boom lower surface and is extended along the longitudinal direction, and is capable of hoisting and horizontally. By a boom that can be laid down to the depression angle with respect to the boom, and can be connected to the front end of the boom, and by rotating with respect to the boom around the connection position of the boom to the front end, A jib that rises or lays down with respect to the boom, the jib that can be arranged on the lower surface of the boom along the longitudinal direction of the boom, a tension rod having one end connected to the jib, and one end of the tension rod. A boom-side link that is connectable to the other end and has the other end connected to the front end portion of the boom on the side closer to the boom upper surface with respect to the connecting position of the jib, and the front end of the boom. Is rotatable with respect to the boom around a connection position to the portion, and is rotated toward the front end toward or away from the front end of the boom by the rotation around the connection position. And a boom side link.

According to the present invention, it is possible to provide a jib overhanging device in which connection and disconnection of a tension rod to a boom head are performed easily and safely, and a construction machine including the jib overhanging device.

FIG. 1 is a schematic diagram showing a crane according to a first embodiment in a state where a jib is arranged on a bottom surface of a boom. FIG. 2 is a schematic view showing a state in which the tension rod is connected to the boom side link and the boom is raised up to the most upright position or an elevation angle close to the most upright position from the state of FIG. FIG. 3 is a schematic diagram showing a state in which the jib hangs from the boom head by extending the boom in the longitudinal direction from the state of FIG. FIG. 4 is a schematic view showing a state in which the boom is contracted in the longitudinal direction to the most contracted state after the boom is turned down from the state of FIG. FIG. 5 is a schematic view showing a state in which the boom is further laid down from the state of FIG. 4 until the front end portion of the jib is located near the ground. FIG. 6 is a schematic diagram showing the crane according to the first embodiment in a state in which the jib is extended to the front side of the boom with respect to the state of hanging from the boom head. FIG. 7 is a perspective view showing a configuration of a front end portion of a boom, a jib, a tension rod, and a boom side link in the crane according to the first embodiment. FIG. 8 is a perspective view showing a configuration of a boom head and a rear end portion of a jib in the crane according to the first embodiment. FIG. 9 is a schematic view showing a state in which the boom is laid down until the depression angle with respect to the horizontal direction becomes larger than a predetermined angle in the jib overhanging device according to the first embodiment. FIG. 10 is a schematic view showing a state in which the engagement of the boom side link with the stopper is released from the state of FIG. 9 to make the boom side link rotatable. FIG. 11 is a schematic view showing a state where the tension rod is connected to the boom side link from the state of FIG. FIG. 12 is a schematic view showing a state in which the boom side link is disengaged from the stopper to make the boom side link rotatable from the state of FIG. 11.

Embodiments of the present invention will be described with reference to FIGS. 1 to 12.

(First embodiment)
1 to 6 show a crane 1 which is a construction machine according to the first embodiment. As shown in FIGS. 1 to 6, the crane 1 includes a traveling vehicle body 2 and a swing body 3 installed on the traveling vehicle body 2. The revolving structure 3 is capable of revolving with respect to the traveling vehicle body 2 around a revolving axis that is parallel or substantially parallel to the vertical direction. The swivel body 3 includes a swivel base 5, a cab 6, and a jib overhanging device 7. The swivel base 5, the cab 6, and the jib overhanging device 7 swivel together with respect to the traveling vehicle body 2. In the cab 6, an operator operates the crane 1 and the like. Further, the traveling vehicle body 2 is provided with a pair of outriggers 8A at the front side portion and a pair of outriggers 8B at the rear side portion.

The jib overhanging device 7 includes a boom 11, a jib 12, a pair of tension rods 13A and 13B, and a pair of boom side links 15A and 15B. Therefore, the crane 1 of this embodiment is a crane with a jib in which the jib 12 is provided. In the present embodiment, when the work is performed using the jib 12 (when the jib 12 is used), the crane 1 is operated in the order of FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. Change the state of. Further, when the jib 12 is stored after using the jib 12, the state of the crane is changed in the order of FIG. 6, FIG. 5, FIG. 4, FIG. 3, FIG.

The boom 11 has a rear end (base end) and a front end (tip), and is extended from the rear end to the front end in the longitudinal direction (front-rear direction). A rear end portion of a boom 11 is connected to the swivel base 5, and the boom 11 can be raised and lowered with respect to the swivel base 5. The crane 1 is provided with a boom hoisting cylinder (not shown) capable of expanding and contracting. One end of the boom hoisting cylinder is connected to the boom 11, and the other end is connected to the swivel base 5. By extending or retracting the boom hoisting cylinder, the boom 11 rises or falls against the swivel 5.

FIG. 7 shows the configuration of the front end portion of the boom 11, the jib 12, the tension rods 13A and 13B, and the boom side links 15A and 15B. In the boom 11, one side in the longitudinal direction is defined as the front side (arrow C1 side), and the side opposite to the front side is defined as the rear side (arrow C2 side). Further, in the boom 11, the width direction (vertical or substantially vertical) intersecting with the longitudinal direction (directions indicated by arrows W1 and W2) and the longitudinal direction and the width direction are intersecting (vertical or substantially vertical). A thickness direction (almost vertical) (directions indicated by arrows Y1 and Y2) are defined. The thickness direction of the boom 11 matches or substantially matches the up-and-down direction of the boom 11.

As shown in FIG. 7 and the like, the outer surface of the boom 11 has a boom upper surface 21, a boom lower surface 22, boom side surfaces 23A and 23B, and a boom front end surface (boom front end surface) 25. In the boom 11, each of the boom upper surface 21, the boom lower surface 22, and the boom side surfaces 23A and 23B extends in the longitudinal direction from the rear end to the front end. Further, the boom front end surface 25 forms the front end of the boom 11, and the boom front end surface 25 faces the front side of the boom 11. The boom upper surface 21 faces one side in the thickness direction of the boom 11 and faces the side where the boom 11 is raised (arrow Y1 side). The boom lower surface 22 faces the side opposite to the boom upper surface 21 in the thickness direction of the boom 11, and faces the side on which the boom 11 lies (arrow Y2 side). When the boom 11 is horizontal, that is, when the longitudinal direction of the boom 11 coincides with the horizontal direction, the boom upper surface 21 faces the vertically upper side and the boom lower surface 22 faces the vertically lower side.

In addition, each of the boom side surfaces 23A and 23B faces outward in the width direction of the boom 11, and the boom side surfaces 23A and 23B face opposite sides in the width direction of the boom 11. In one example, the boom side surface 23A faces the left side of the boom 11, and the boom side surface 23B faces the right side of the boom 11. Each of the boom upper surface 21, the boom lower surface 22, and the boom front end surface 25 is extended along the width direction of the boom 11 between the boom side surfaces 23A and 23B. Further, each of the boom side surfaces 23A, 23B and the boom front end surface 25 is extended between the boom upper surface 21 and the boom lower surface 22 along the thickness direction of the boom 11 (the undulating direction of the boom 11). A boom head 17 is provided at the front end (tip) of the boom 11. In the boom 11, the boom head 17 forms the front end of the boom 11 and the boom front end surface 25.

Moreover, in this embodiment, the boom 11 is extendable/contractible in the longitudinal direction. The boom 11 includes a base boom 16 and one or more movable booms 18 that are movable with respect to the base boom 16 in the longitudinal direction of the boom 11. In the present embodiment, five movable booms 18 are provided on the boom 11. Further, in the present embodiment, the base boom 16 forms the rear end of the boom 11, and the frontmost movable boom 18 forms the front end of the boom 11 and the boom head 17. A boom telescopic cylinder (not shown) is provided inside the boom 11. By extending or contracting the boom telescopic cylinder, any one of the movable booms 18 moves with respect to the base boom 16 along the longitudinal direction of the boom 11. As a result, the protruding length of the movable boom 18 from the base boom 16 to the front side of the boom 11 changes, and the boom 11 extends or contracts in the longitudinal direction.

The boom 11 can be raised and lowered with respect to the swivel base 5 between the most raised position and the most folded position. In the boom 11 in the most upright position, the front side (tip side) of the boom 11 is positioned vertically upward in the longitudinal direction. That is, in the most upright position, the longitudinal direction of the boom 11 forms an elevation angle with the horizontal direction. In one example, the boom 11 has an elevation angle of 80° or more and less than 90° at the most upright position. Further, in the boom 11 at the outermost position, the frontward portion in the longitudinal direction is positioned vertically downward. That is, in the most prone position, the longitudinal direction of the boom 11 forms a depression angle with respect to the horizontal direction. Therefore, in the present embodiment, the boom 11 can be laid down beyond the horizontal state until it becomes a depression angle with respect to the horizontal direction. That is, the boom 11 of this embodiment is a so-called slant boom. When the crane 1 travels, the boom 11 is in a state of being laid down until it forms a depression angle with respect to the horizontal direction, for example, in a state of being laid down to the most prone position.

A boom-side coupling 26 is provided on the boom 11. In the boom 11, the boom side coupling 26 is arranged rearward of the boom head 17. In the present embodiment, the boom side coupling 26 is provided on the base boom 16 and is provided at an intermediate portion of the base boom 16 in the longitudinal direction of the boom 11.

Guide sheaves 31, 32, a top sheave (boom top sheave) 33, and a rooster sheave 35 are attached to the boom head 17. The guide sheave 32 is attached to the boom head 17 (front end portion of the boom 11) via a shaft (shaft for guide sheave) 36, and the top sheave 33 is attached to the boom head via a shaft (shaft for top sheave) 37. It is attached to 17 (the front end of the boom 11). Each of the shafts 36 and 37 extends along the width direction of the boom 11. The guide sheaves 31, 32 and the shaft 36 are arranged on the side closer to the boom upper surface 21, that is, on the side where the boom 11 is raised, with respect to the top sheave 33, the rooster sheave 35, and the shaft 37. The guide sheave 32, the rooster sheave 35, and the shaft 36 are arranged on the front side of the guide sheave 31, the top sheave 33, and the shaft 37. Further, at the front end portions of the boom side surfaces 23A and 23B, respectively, the shafts 36 and 37 project outward in the width direction of the boom 11.

In the present embodiment, a main hoisting rope 41 extends from a main winch (not shown) of the swivel base 5, and the main hoisting rope 41 extends from the rear side to the front side on the boom upper surface 21. The main winding rope 41 is hung on the guide sheave 31 and the top sheave 33, and the main hook 42 is suspended from the top sheave 33 via the main winding rope 41. Further, in the present embodiment, the auxiliary winding rope 43 extends from the auxiliary winch (not shown) of the swivel base 5, and the auxiliary winding rope 43 extends from the rear side to the front side on the boom upper surface 21. Then, when the jib 12 is not used (when the jib 12 is not used), the auxiliary winding rope 43 is hooked on the guide sheave 32 and the rooster sheave 35, and the auxiliary hook 45 moves from the rooster sheave 35 to the auxiliary winding rope 43. Is hung through. Further, in the present embodiment, the hook-in brackets 27 and 28 are attached to the boom head 17. The hook-in bracket 27 can store the main hook 42, and the hook-in bracket 28 can store the auxiliary hook 45.

The jib 12 has a rear end (base end) and a front end (front end), and extends from the rear end to the front end along the longitudinal direction (front-rear direction). In the jib 12, one side in the longitudinal direction is defined as the front side (arrow C3 side), and the side opposite to the front side is defined as the rear side (arrow C4 side). Further, the jib 12 has a width direction (vertical or substantially vertical) intersecting with the longitudinal direction (direction shown by arrows W3 and W4), and intersects with both the longitudinal direction and the width direction (vertical or A thickness direction (almost vertical) (directions indicated by arrows Y3 and Y4) are defined. In the crane 1, the width direction of the jib 12 matches or substantially matches the width direction of the boom 11.

The outer surface of the jib 12 has a jib upper surface 46, a jib lower surface 47, and jib side surfaces 48A, 48B. In the jib 12, each of the jib upper surface 46, the jib lower surface 47, and the jib side surfaces 48A, 48B extends along the longitudinal direction from the rear end to the front end. The jib upper surface 46 faces one side (arrow Y3 side) in the thickness direction of the jib 12, and the jib lower surface 47 faces the opposite side (arrow Y4 side) from the jib upper surface 46 in the thickness direction of the jib 12. Further, each of the jib side surfaces 48A, 48B faces outward in the width direction of the jib 12, and the jib side surfaces 48A, 48B face opposite sides with respect to each other in the width direction of the jib 12. In one example, the jib side surface 48A faces the left side of the jib 12, and the jib side surface 48B faces the right side of the jib 12. Each of the jib upper surface 46 and the jib lower surface 47 extends along the width direction of the jib 12 between the jib side surfaces 48A and 48B. Further, each of the jib side surfaces 48A and 48B is provided along the thickness direction of the jib 12 between the jib upper surface 46 and the jib lower surface 47.

In this embodiment, the jib 12 is expandable/contractible in the longitudinal direction. The jib 12 includes a base jib 51 and a movable jib 52 that is movable with respect to the base jib 51 along the longitudinal direction of the jib 12. In this embodiment, the base jib 51 forms the rear end of the jib 12, and the movable jib 52 forms the front end of the jib 12. When the movable jib 52 moves along the longitudinal direction of the jib 12 with respect to the base jib 51, the protruding length of the movable jib 52 from the base jib 51 to the front side of the jib 12 changes, and the jib 12 extends in the longitudinal direction. Or contract. Further, in the present embodiment, the jib telescopic cylinder or the like is not provided, and for example, the movable jib 52 is manually moved to extend or contract the jib 12. Although only one movable jib 52 is provided in the present embodiment, a plurality of movable jib 52 may be provided. In this case, the frontmost movable jib 52 forms the front end of the jib 12. Further, in one example, the movable jib 52 may not be provided on the jib 12, and the jib 12 may be formed only from the base jib 51. In this case, the jib 12 cannot expand and contract in the longitudinal direction.

FIG. 8 is a diagram showing the configuration of the rear end portion (base end portion) of the boom head 17 and the jib 12. As shown in FIG. 7 and FIG. 8 and the like, a pair of jib foot 53A, 53B is provided at the rear end of the base jib 51 of the jib 12, and the jib foot 53A, 53B are separated from each other in the width direction of the jib 12. Are arranged. Therefore, the rear end portion of the base jib 51 is formed in a bifurcated shape, and a space is formed between the jib foot 53A and 53B in the width direction of the jib 12. In the present embodiment, each of the jib foots 53A and 53B forms the rear end of the jib 12. The respective rear ends of the jib foot (jib side engaging portions) 53A and 53B can be engaged with the shaft (boom side engaging portion) 37 for the top sheave 33. In this embodiment, the jib foot 53A is engageable with the protruding portion of the shaft 37 from the boom side surface 23A to the outside, and the jib foot 53B is engageable with the protruding portion of the shaft 37 from the boom side surface 23B to the outside. ..

A foot pin 55 can be attached to each of the jib foot 53A and 53B. In each of the jib foots 53A and 53B, the attached foot pin 55 prevents the engagement with the shaft 37 from being released. Therefore, with the jib foot 53A, 53B engaged with the shaft 37, the foot pin 55 is attached to each of the jib foot 53A, 53B, whereby the jib 12 is connected to the boom head 17 (the front end portion of the boom 11). In the present embodiment, the shaft 37 for the top sheave 33 is the connecting position of the jib 12 to the boom head 17. When the jib 12 is connected to the boom head 17 at the connection position (shaft 37), the jib 12 moves in association with the extension or contraction of the boom 11 in the longitudinal direction. On the other hand, when the jib 12 is not connected to the boom head 17 at the connection position (shaft 37), the jib 12 does not move even if the boom 11 extends or contracts in the longitudinal direction. A jib side coupling 56 (see FIG. 7) is provided on the base jib 51 of the jib 12. The jib side coupling 56 can be connected to the boom side coupling 26.

A slide bracket 60 is attached to the outer surface of the base jib 51. The slide bracket 60 is movable with respect to the base jib 51 along the longitudinal direction of the jib 12. A pair of jib undulating cylinders 61A and 61B are attached to the base jib 51 of the jib 12. The jib undulation cylinder 61A is arranged on the jib side surface 48A, and the jib undulation cylinder 61B is arranged on the jib side surface 48B. Each of the jib undulation cylinders 61</b>A and 61</b>B extends in parallel with each other along the longitudinal direction of the jib 12, and is expandable and contractable in the longitudinal direction of the jib 12. One end (front end) of each of the jib undulating cylinders 61A and 61B is connected to the slide bracket 60. The other ends (rear ends) of the jib undulating cylinders 61A and 61B are connected to the base jib 51. The connection positions of the jib undulation cylinders 61A and 61B to the base jib 51 are located on the rear side of the jib 12 with respect to the slide bracket 60 and on the front side of the jib 12 with respect to the jib foots 53A and 53B.

The slide bracket 60 is located at the rearmost rearmost position when the jib undulating cylinders 61A and 61B are in the most contracted state. The slide bracket 60 is located at the foremost frontmost position when the jib undulating cylinders 61A and 61B are most extended. Therefore, the slide bracket 60 is movable along the longitudinal direction of the jib 12 between the rearmost position and the frontmost position. Even when the slide bracket 60 is located at the rearmost position, the slide bracket 60 is located on the front side of the jib 12 with respect to the jib foot 53A, 53B. Further, even when the slide bracket 60 is located at the frontmost position, the slide bracket 60 is located on the outer surface of the base jib 51, and the slide bracket 60 is not located on the outer surface of the movable jib 52.

The pair of tension rods 13</b>A and 13</b>B extend in parallel to each other and are arranged on the side where the jib upper surface 46 faces the jib 12. Each of the tension rods 13A and 13B extends from the front end (one end) to the rear end (other end) along the axial direction, and extends from the rear side of the jib 12 to the front side of the jib 12. The tension rods 13A and 13B are arranged apart from each other in the width direction of the jib 12. The front ends of the tension rods 13A and 13B are connected to the slide bracket 60. Therefore, the front ends of the tension rods 13A and 13B are connected to the base jib 51 of the jib 12 via the slide bracket 60.

Each of the tension rods 13A and 13B includes a rod body 62 and an extension 63. In each of the tension rods 13A and 13B, the extension 63 forms a front end (one end), and the rod body 62 forms a rear end (other end). Further, the extension 63 is connected to the slide bracket 60 in each of the tension rods 13A and 13B. Then, in each of the tension rods 13A and 13B, the rod body 62 is movable in the axial direction with respect to the extension 63. Therefore, each of the tension rods 13A and 13B can expand and contract in the axial direction. In each of the tension rods 13A and 13B, the movement of the rod body 62 with respect to the extension 63 along the axial direction can be regulated by a set pin (not shown). By restricting the movement of the rod body 62 with respect to the extension 63 by the set pin, expansion and contraction of each of the tension rods 13A and 13B is restricted, and the length in the axial direction is maintained. In the present embodiment, each of the tension rods 13A and 13B can maintain the dimension in the axial direction at least with a predetermined reference length by the set pin.

The base jib 51 of the jib 12 is provided with a pair of rod receivers 65A and 65B. The rod receivers 65A and 65B are formed on the upper surface 46 of the jib and project toward the side of the base jib 51 on which the upper surface 46 of the jib faces. The rod receivers 65</b>A and 65</b>B are arranged on the rear side of the jib 12 with respect to the jib side coupling 56, and are arranged apart from each other in the width direction of the jib 12. The rod receiver 65A can be engaged with the tension rod 13A and can support the tension rod 13A. Further, the rod receiver 65B can be engaged with the tension rod 13B and can support the tension rod 13B.

A top sheave (jib top sheave) 66 is attached to the movable jib 52 of the jib 12. The top sheave 66 is located at the front end of the jib 12. When working with the jib 12 (when the jib 12 is used), the auxiliary winding rope 43 extends from the guide sheave 32 at the front end of the boom 11 to the jib upper surface 46. The auxiliary winding rope 43 extends from the rear side to the front side on the upper surface 46 of the jib. Then, the auxiliary winding rope 43 is hung on the top sheave 66, and the auxiliary hook 45 is hung from the top sheave 66 via the auxiliary winding rope 43.

The pair of boom-side links 15A and 15B are attached to the boom head 17 and extend parallel to each other. Each of the boom-side links 15A and 15B extends along the axial direction from the front end (one end) to the rear end (other end). The boom-side links 15A and 15B are arranged apart from each other in the width direction of the jib 12. The front end of the boom side link 15A can be connected to the rear end of the tension rod 13A, and the front end of the boom side link 15B can be connected to the rear end of the tension rod 13B. Therefore, each of the pair of tension rods 13A and 13B can be connected to the corresponding one of the pair of boom-side links 15A and 15B.

The rear ends (other ends) of the boom-side links 15A and 15B are connected to the boom head 17 (the front end portion of the boom 11). In the present embodiment, the rear ends of the boom-side links 15A and 15B are connected to the shaft (boom-side connecting portion) 36 for the guide sheave 32. In the present embodiment, the boom side link 15A is connected to the protruding portion of the shaft 36 from the boom side surface 23A to the outside, and the boom side link 15B is connected to the protruding portion of the shaft 36 from the boom side surface 23B to the outside. Therefore, the rear ends of the boom-side links 15A and 15B are connected to the boom head 17 on the side closer to the boom upper surface 21 with respect to the connecting position (the shaft 37) of the jib 12 to the boom head 17. That is, the connecting position (shaft 36) of the boom-side links 15A and 15B to the boom head 17 is the side where the boom 11 is raised (arrow Y1 side) with respect to the connecting position (shaft 37) of the jib 12 to the boom head 17. Located in. Further, each of the boom-side links 15A and 15B can be connected to the corresponding one of the tension rods 13A and 13B in a region on the side where the boom lower surface 22 faces the connection position (shaft 36) to the boom head 17. is there.

Each of the boom-side links 15A and 15B is rotatable with respect to the boom 11 around the connection position (shaft 36) to the boom head 17. The boom-side links 15A and 15B are arranged on the front side of the boom 11 with respect to the boom head 17 and on the front side of the boom 11 with respect to the boom front end surface 25. Each of the boom-side links 15A and 15B rotates around a connection position to the boom head 17 to approach the boom head 17 from the front side of the boom 11 or separate from the front side of the boom 11. .. Therefore, each of the boom-side links 15A and 15B opens or closes with respect to the boom front end surface 25 by rotating around the connection position to the boom head 17.

Further, due to the rotation around the connection position to the boom head 17, the angle (acute angle) in the axial direction of each of the boom-side links 15A and 15B with respect to the up-and-down direction of the boom 11 (thickness direction of the boom 11) changes. To do. For example, each of the boom-side links 15A and 15B comes closer to the boom head 17 from the front side by the rotation, so that the angle with respect to the undulating direction of the boom 11 becomes smaller. On the other hand, each of the boom-side links 15A and 15B separates from the boom head 17 to the front side by the rotation, so that the angle with respect to the up-and-down direction of the boom 11 increases.

Further, the boom head 17 of the boom 11 is provided with a pair of stoppers 67A and 67B. The stoppers 67A and 67B are located on the side close to the boom lower surface 22, that is, on the side where the boom 11 is turned down, with respect to the connection position (shaft 36) of the boom side links 15A and 15B to the boom head 17. The stopper 67A is engageable with the boom side link 15A closest to the boom head 17, and the stopper 67B is engageable with the boom side link 15B closest to the boom head 17. Each of the boom-side links 15A and 15B engages with a corresponding one of the stoppers 67A and 67B, so that rotation around the connecting position to the boom head 17 is restricted. Therefore, each of the boom-side links 15A and 15B is maintained in a state of being closest to the boom head 17 (boom front end face 25) by engaging with one of the corresponding stoppers 67A and 67B, and the boom 11 is raised and lowered. The angle to the direction is kept at the minimum angle. The stoppers 67A and 67B may be removable from the boom head 17.

Here, each of the boom-side links 15A and 15B forms a predetermined angle α with respect to the up-and-down direction of the boom 11 when the boom-side links 15A and 15B are closest to the boom head 17 (boom front end surface 25). That is, the minimum angle formed by the respective axial directions of the boom-side links 15A and 15B with respect to the up-and-down direction of the boom 11 is a predetermined angle α. Further, the depression angle β with respect to the horizontal direction in the longitudinal direction of the boom 11 is defined when the boom 11 is in a state of lying down beyond the horizontal state. At the most prone position where the boom 11 is most prone, the depression angle β of the boom 11 is the maximum depression angle β0. In the present embodiment, the maximum depression angle β0 is larger than the above-mentioned predetermined angle α.

Next, the work using the jib 12 will be described. In the present embodiment, as shown in FIG. 1, the jib side coupling 56 is connected to the boom side coupling 26 when the jib 12 is not used, such as when the crane 1 is traveling. Then, when the jib 12 is not used, the jib 12 is stored on the boom lower surface 22 of the boom 11 along the longitudinal direction of the boom 11. Therefore, the jib 12 can be arranged on the lower surface 22 of the boom along the longitudinal direction of the boom 11. When the jib 12 is placed on the boom lower surface 22, the jib lower surface 47 of the jib 12 faces the boom lower surface 22. Then, the jib 12 is arranged such that the tip end side of the jib 12 coincides or substantially coincides with the base end side of the boom 11, and the base end side of the jib 12 coincides or substantially coincides with the tip end side of the boom 11.

When the boom 11 is arranged on the lower surface 22 of the boom by the boom side coupling 26, the jib side coupling 56, etc., the boom 11 is contracted to the most contracted state, so that the jib foot (the jib side engaging portion). Each of 53A and 53B engages with the shaft (boom side engaging portion) 37. Further, when the jib 12 is not used, each of the jib undulating cylinders 61A and 61B is in the most contracted state, and the slide bracket 60 is located at the rearmost rearmost position.

Further, as described above, the tension rods 13A and 13B are arranged on the side where the jib upper surface 46 faces the jib 12. Therefore, when the jib 12 is arranged on the lower surface 22 of the boom along the longitudinal direction, the tension rods 13A and 13B are arranged on the side opposite to the side where the boom 11 is located with respect to the jib 12. Further, when the jib 12 is not used when traveling, the tension rods 13A and 13B are stored in a state where the axial lengths thereof are short and cannot be connected to the boom-side links 15A and 15B. When the jib 12 is not used, each of the tension rods 13A and 13B engages with the corresponding one of the rod receivers 65A and 65B and is supported by the corresponding one of the rod receivers 65A and 65B.

When the jib 12 is not used, such as when traveling, each of the boom-side links 15A and 15B engages with the corresponding one of the stoppers 67A and 67B. Therefore, when the jib 12 is not used, each of the boom-side links 15A and 15B is restricted from rotating around the connection position (the shaft 36) to the boom head 17, and the boom head 17 (boom front end face 25). Maintained in the state of being closest to. The main hook 42 is stored in the hook-in bracket 27 and the auxiliary hook 45 is stored in the hook-in bracket 28 when the vehicle is running.

When performing work using the jib 12, as shown in FIG. 1, the outriggers 8A and 8B are installed on the ground to stabilize the traveling vehicle body 2. In addition, the boom 11 is laid down until the depression angle β with respect to the horizontal direction. At this time, it is preferable that the boom 11 is laid down to a state where the depression angle β with respect to the horizontal direction becomes larger than the predetermined angle α described above. Further, the boom 11 is in the most contracted state, and the jib foot 53A, 53B is in a state of being engaged with the shaft 37. In this state, the foot pins 55 are attached to the jib foot 53A and 53B, respectively, and the rear end (rear end) of the jib 12 is connected to the boom head 17 (front end of the boom 11).

Then, as shown in FIG. 2 and the like, each of the tension rods 13A and 13B is extended from the stored state and connected to the corresponding one of the boom side links 15A and 15B. Then, the engagement of the boom-side links 15A, 15B with the corresponding one of the stoppers 67A, 67B is released, and the boom-side links 15A, 15B are centered around the connection position (shaft 36) to the boom head 17. Make it rotatable. It should be noted that in a state where the engagement of the boom side links 15A, 15B with the corresponding one of the stoppers 67A, 67B is released, the corresponding one of the tension rods 13A, 13B is attached to each of the boom side links 15A, 15B. May be connected. Further, in FIG. 8 described above, the jib 12 arranged on the lower surface 22 of the boom is connected to the shaft 37 (connection position) of the boom head 17, and the tension rods 13A and 13B correspond to the boom-side links 15A and 15B, respectively. The state of being connected to one side is shown.

When one of the tension rods 13A and 13B is connected to each of the boom-side links 15A and 15B, a hose or the like that supplies hydraulic pressure to the jib undulating cylinders 61A and 61B is attached to the boom 11. Further, the tension rods 13A and 13B are disengaged from the corresponding ones of the rod receivers 65A and 65B, and the tension rods 13A and 13B are released.

After performing the above-described work, as shown in FIG. 2, the boom 11 is raised to the most raised position or an elevation angle close to the most raised position. Then, as shown in FIG. 3, the boom 11 is extended from the most contracted state. The extension of the boom 11 releases the connection of the jib side coupling 56 with the boom side coupling 26. That is, the connection of the jib 12 to the boom 11 at a portion other than the connection position (the shaft 37) to the boom head 17 is released. Then, the jib 12 is connected to the boom 11 only by the shaft 37 of the boom head 17 (the front end portion of the boom 11), and the jib 12 with respect to the boom 11 centering on the connection position (shaft 37) to the boom head 17. It becomes rotatable. Further, by releasing the connection to the boom side coupling 26 or the like as described above, the jib 12 is in a state of being hung or substantially hung from the position of connection to the boom head 17. When the jib 12 is drooping or substantially drooping, the longitudinal direction of the jib 12 matches or substantially matches the vertical direction. The front side of the jib 12 coincides or substantially coincides with the vertically lower side, and the rear side of the jib 12 coincides or substantially coincides with the vertically upper side.

Then, as shown in FIG. 4, after the boom 11 is laid down from the most raised position or an elevation angle close to the most raised position, the boom 11 is contracted to the most contracted state. At this time, the boom 11 is laid down until the elevation angle reaches about 40°. Then, as shown in FIG. 5, the boom 11 is further laid down until the front end portion of the jib 12 is located near the ground. Here, even when the boom 11 is laid down until the front end of the jib 12 is located near the ground, the boom 11 has an elevation angle with respect to the horizontal direction, for example, the boom 11 lays down until the elevation angle becomes about 32°. .. Further, when the boom 11 is being laid down until the front end portion of the jib 12 is located near the ground, each of the tension rods 13A and 13B can expand and contract in the axial direction. Therefore, when the boom 11 is laid down until the front end portion of the jib 12 is located near the ground, the angle formed by the longitudinal direction of the jib 12 with respect to the longitudinal direction of the boom 11 changes. Therefore, even when the boom 11 is laid down until the front end portion of the jib 12 is located near the ground, the jib 12 is maintained in a state of hanging or substantially depending from the boom head 17.

Further, when the front end portion of the jib 12 is located near the ground, each of the tension rods 13A and 13B has a length in the axial direction that is the above-described predetermined reference length or a value close to the predetermined reference length. become. Then, with the front end of the jib 12 positioned near the ground, set pins are attached to the tension rods 13A and 13B, respectively. As a result, each of the tension rods 13A and 13B is maintained at a predetermined reference length in the axial direction by the set pin. The auxiliary winding rope 43 is hung on the top sheave 66 in a state where the front end of the jib 12 is located near the ground.

Then, after maintaining the lengths of the tension rods 13A and 13B in the respective axial directions at predetermined reference lengths, as shown in FIG. 6, the boom 11 is moved to the most raised position or an elevation angle close to the most raised position. Wake up. At this time, since each of the tension rods 13A and 13B is maintained at a predetermined reference length, even if the boom 11 is raised, the angle formed by the longitudinal direction of the jib 12 with respect to the longitudinal direction of the boom 11 does not change. .. Therefore, by raising the boom 11 to the most raised position or an elevation angle close to the most raised position, the jib 12 is extended to the front side of the boom 11 with respect to the state in which the jib 12 hangs down from the boom head 17. Become. Then, when the jib 12 is extended to the front side of the boom 11 with respect to the state of hanging from the boom head 17, the jib undulating cylinders 61A and 61B are extended or contracted to move the slide bracket 60 with respect to the base jib 51. Let As a result, the jib 12 rotates with respect to the boom 11 about the connecting position (the shaft 37) to the boom head 17, and the jib 12 rises or lies down with respect to the boom 11.

In this embodiment, the jib 12 is in the most laid down state with respect to the boom 11 in a state where the jib hoisting cylinders 61A and 61B are most contracted and the slide bracket 60 is located at the rearmost position. On the other hand, the jib 12 is in the most raised position with respect to the boom 11 when the jib hoisting cylinders 61A and 61B are most extended and the slide bracket 60 is located at the most front position. Even when the jib 12 is most prone to the boom 11, the jib 12 is extended to the front side of the boom 11 with respect to the state where the jib 12 hangs down from the boom head 17. Further, the undulating direction of the jib 12 coincides or substantially coincides with the thickness direction of the jib 12. The side facing the jib upper surface 46 (arrow Y3 side) matches or substantially matches the side where the jib 12 occurs, and the side facing the jib lower surface 47 (arrow Y4 side) matches or substantially matches the side where the jib 12 lies. To do.

Here, in FIG. 6, the state A1 shows the state in which the jib 12 is most prone to the boom 11, and the state A2 shows the state in which the jib 12 is most upright with respect to the boom 11. The state A3 indicates a state between the state A1 and the state A2. In addition, FIG. 7 illustrates a state in which the jib 12 is extended to the front side of the boom 11 with respect to the state of hanging from the boom head 17, as in FIG. 6.

When the work using the jib 12 is completed, the jib 12 is arranged on the boom lower surface 22 of the boom 11 along the longitudinal direction of the boom 11 as described above by performing a procedure substantially reverse to the procedure described above. To store. At this time, the foot pin 55 is removed from each of the jib foot 53A and 53B, and the connection of the jib 12 to the boom head 17 is released. Further, the connection of the tension rods 13A and 13B to the corresponding one of the boom side links 15A and 15B is released. Further, each of the tension rods 13A and 13B is engaged with the corresponding one of the rod receivers 65A and 65B, and is contracted in the axial direction to such an extent that it cannot be connected to the boom-side links 15A and 15B. Then, each of the boom-side links 15A and 15B is engaged with the corresponding one of the stoppers 67A and 67B.

9 to 12 show a state in which the boom 11 is laid down until the depression angle β with respect to the horizontal direction becomes larger than the predetermined angle α described above. In the states of FIGS. 9 and 10, the tension rods 13A and 13B are not connected to the boom-side links 15A and 15B. Further, in the state of FIGS. 11 and 12, each of the tension rods 13A and 13B is connected to the corresponding one of the boom side links 15A and 15B. Then, in the state of FIGS. 9 and 11, each of the boom-side links 15A and 15B engages with the corresponding one of the stoppers 67A and 67B, and rotation about the connection position to the boom head 17 is restricted. ing. Further, in the state of FIGS. 10 and 12, each of the boom-side links 15A and 15B is disengaged from the corresponding one of the stoppers 67A and 67B and is rotatable around the connection position to the boom head 17. is there. 9 to 12, the jib 12 is arranged on the lower surface 22 of the boom along the longitudinal direction of the boom 11, and the tension rods 13A and 13B respectively correspond to the rod receivers 65A and 65B. Is engaged with.

As shown in FIGS. 9 to 12, each of the tension rods 13A and 13B is connected to the boom head 17 (the front end portion of the boom 11) via the corresponding one of the boom-side links 15A and 15B. The connection and disconnection of the tension rods 13A and 13B with respect to the corresponding one of the boom-side links 15A and 15B are performed by disposing the jib 12 on the boom lower surface 22 and connecting the tension rods 13A and 13B to the rod receiving members. It is performed while being supported by the corresponding one of 65A and 65B. Further, each of the boom-side links 15A and 15B is connected to a corresponding one of the tension rods 13A and 13B in a region where the boom lower surface 22 faces the connection position (shaft 36) to the boom head 17. .. When connecting or disconnecting the corresponding one of the tension rods 13A, 13B to or from the boom-side links 15A, 15B, each of the boom-side links 15A, 15B should be connected to the corresponding one of the stoppers 67A, 67B. May be engaged or disengaged. As described above, since each of the tension rods 13A and 13B is connected to the boom head 17 via the corresponding one of the boom side links 15A and 15B, the boom head 17 of the tension rods 13A and 13B (the front end portion of the boom 11). ) Is easily and safely connected and disconnected.

In the present embodiment, the boom 11 can be laid down beyond the horizontal state until the depression angle β with respect to the horizontal direction. Therefore, it is possible to connect and disconnect the tension rods 13A and 13B to and from the corresponding one of the boom-side links 15A and 15B with the boom 11 lying down until the depression angle β with respect to the horizontal direction. Is. In the state where the boom 11 is laid down until the depression angle β with respect to the horizontal direction, the connection and connection of the tension rods 13A and 13B with respect to the corresponding one of the boom side links 15A and 15B in comparison with the state where the boom 11 is horizontal. The work position for release is close to the ground. Therefore, workability and safety are improved when the tension rods 13A and 13B are connected to and disconnected from the boom head 17 (the front end of the boom 11).

In addition, by lowering the boom 11 down to the depression angle β with respect to the horizontal direction, the working position for engaging and releasing the corresponding one of the rod receivers 65A, 65B of the tension rods 13A, 13B is also on the ground. Get closer. Therefore, workability and safety are improved even when the tension rods 13A and 13B are engaged and disengaged with the corresponding one of the rod receivers 65A and 65B. Further, the boom 11 is laid down until the depression angle β with respect to the horizontal direction, so that the work of attaching a hose or the like for supplying hydraulic pressure to the jib hoisting cylinders 61A and 61B to the boom 11 can be performed easily and safely.

Further, in the present embodiment, the hook-in brackets 27, 28 are attached to the boom head 17. Therefore, even if the boom 11 is turned down to the depression angle β with respect to the horizontal direction, by storing the main hook 42 in the hook-in bracket 27 and the auxiliary hook 45 in the hook-in bracket 28, the main hook can be stored. The contact of 42 and the auxiliary hook 45 with the ground is effectively prevented.

Further, in a state in which each of the boom-side links 15A and 15B is rotatable about the connection position to the boom head 17, the boom 11 is turned down until the depression angle β with respect to the horizontal direction becomes larger than the predetermined angle α described above. The boom-side links 15A and 15B are hung or substantially hung from the connection position (shaft 36) to the boom head 17 due to their own weight (see FIGS. 10 and 12). At this time, each of the boom-side links 15A and 15B separates from the boom head 17 toward the front side of the boom 11 as compared with the state in which the boom-side links 15A and 15B are engaged with the corresponding one of the stoppers 67A and 67B. Then, in a state where the boom-side links 15A and 15B respectively hang down or substantially hang down from the connection position (shaft 36) to the boom head 17, the angle of the boom-side links 15A and 15B with respect to the undulating direction of the boom 11 is the boom. It becomes the same as or almost the same as the depression angle β of 11. In a state where the boom-side links 15A and 15B hang down or substantially hang down, the respective axial directions of the boom-side links 15A and 15B match or substantially match the vertical direction. Each of the boom-side links 15A and 15B extends vertically downward from the connection position to the boom head 17.

With the corresponding one of the tension rods 13A and 13B connected to each of the boom-side links 15A and 15B, the corresponding one of the tension rods 13A and 13B is rotated by rotating each of the boom-side links 15A and 15B. Moving. Then, in response to the boom 11 lying down until the depression angle β becomes larger than the predetermined angle α, and the corresponding one of the boom-side links 15A and 15B hangs or substantially hangs from the boom head 17, The tension rods 13</b>A and 13</b>B are closer to the jib 12 than when the boom 11 is horizontal. That is, in the state in which the boom 11 is laid down until the depression angle β becomes larger than the predetermined angle α as compared with the state in which the boom 11 is horizontal, each of the tension rods 13A and 13B approaches the upper surface 46 of the jib.

Each of the tension rods 13A and 13B easily bends, especially when not supported by the rod receivers 65A and 65B. However, in the present embodiment, as described above, when the boom 11 is laid down until the depression angle β becomes larger than the predetermined angle α, the tension rods 13A and 13B move with respect to the jib 12 as compared with the case where the boom 11 is horizontal. Get closer. Therefore, even if the boom 11 is turned down until the depression angle β becomes larger than the predetermined angle α, the clearances of the tension rods 13A and 13B with respect to the traveling vehicle body 2 are secured. This effectively prevents the tension rods 13A and 13B from interfering with the traveling vehicle body 2.

Further, in the state in which the boom 11 is laid down until the depression angle β becomes larger than the predetermined angle α, the tension rods 13A and 13B are closer to the jib 12 than in the state in which the boom 11 is horizontal. It is easy to engage each with the corresponding one of the rod receivers 65A and 65B. Therefore, workability and safety are improved when the tension rods 13A and 13B are engaged with the corresponding one of the rod receivers 65A and 65B.

Further, as described above, since the tension rods 13A and 13B are closer to the jib 12 than when the boom 11 is horizontal, each of the tension rods 13A and 13B is boomed when the depression angle β is larger than a predetermined angle α. After connecting to the corresponding one of the side links 15A and 15B, the boom 11 can be further laid down. By doing so, work such as attaching a hose to the boom 11 can be performed with the depression angle β further increased from the state where the tension rods 13A and 13B are connected to the corresponding ones of the boom side links 15A and 15B. Will be possible.

(Modification)
Although the slide bracket 60 is attached to the jib 12 in the above-described embodiment, the slide bracket 60 may not be provided in a certain modified example, and the jib hoisting cylinder may be provided inside the jib 12. In this case, by expanding or contracting the jib undulating cylinder, any one of the movable jib 52 moves along the longitudinal direction in the jib 12, and the jib 12 expands or contracts in the longitudinal direction. Then, one end (front end) of each of the tension rods 13A and 13B is connected to a movable jib 52 that moves in response to the operation of the jib undulating cylinder. In this modification, when the jib 12 is extended to the front side of the boom 11 with respect to the state of hanging from the boom head 17, the jib hoisting cylinder is extended or contracted, and the jib 12 is extended or contracted in the longitudinal direction. .. This causes the jib 12 to rise or lie against the boom 11. At this time, for example, the jib 12 is raised with respect to the boom 11 by extending the jib 12. Then, by contracting the jib 12, the jib 12 lies down on the boom 11.

In another modification, a pair of jib undulating cylinders is provided, and one end (front end) of each of the tension rods 13A and 13B is connected to a corresponding one of the jib undulating cylinders. Then, each of the tension rods 13A and 13B is connected to the base jib 51 via the corresponding one of the jib undulating cylinders. In the present modification, when the jib 12 is extended to the front side of the boom 11 with respect to the state of hanging from the boom head 17, each of the jib hoisting cylinders is extended or contracted, and the boom head 17 and the jib 12 are separated from each other. Change the length of the space between them. This causes the jib 12 to rise or lie against the boom 11. At this time, the jib 12 is raised with respect to the boom 11, for example, by contracting each of the jib undulating cylinders. Then, by extending each of the jib hoisting cylinders, the jib 12 is turned down with respect to the boom 11.

In a modification, the jib 12 is arranged in one of the boom side surfaces 23A, 23B in the longitudinal direction of the boom 11 and stored along one of the boom side surfaces 23A, 23B when traveling. In this case, the mechanism for moving the jib 12 between the state where the boom 11 is arranged on one of the boom side surfaces 23A and 23B in the longitudinal direction of the boom 11 and the state where it is arranged on the lower surface 22 of the boom 11 in the longitudinal direction of the boom 11 is Etc. When the jib 12 is used, the jib 12 is moved from the state of being arranged on one of the boom side surfaces 23A, 23B to the state of being arranged on the boom lower surface 22. Then, the work is performed using the jib 12 in the same manner as the above-described embodiment and the like. Further, when the jib 12 is stored, the jib 12 is arranged on the boom lower surface 22 in the same manner as the above-described embodiment. Then, the jib 12 is moved from the state of being arranged on the boom lower surface 22 to the state of being arranged on one of the boom side surfaces 23A, 23B.

It should be noted that the present invention is not limited to the above-described embodiment, and can be variously modified at the stage of implementation without departing from the spirit of the invention. Further, the respective embodiments may be appropriately combined and implemented, in which case the combined effects can be obtained. Further, the above-described embodiment includes various inventions, and various inventions can be extracted by a combination selected from a plurality of disclosed constituent features. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, if the problem can be solved and the effect can be obtained, the structure in which the constituent elements are deleted can be extracted as the invention.

DESCRIPTION OF SYMBOLS 1... Crane, 2... Running vehicle, 3... Revolving structure, 5... Revolving base, 7... Jib overhanging device, 11... Boom, 12... Jib, 13A, 13B... Tension rod, 15A, 15B... Boom side link, 17... Boom head, 21... Boom upper surface, 22... Boom lower surface, α... Predetermined angle, β... Depression angle.

Claims (4)

A boom that has a boom upper surface and a boom lower surface and is extended along the longitudinal direction, and that can be undulated and can be laid down to a depression angle with respect to the horizontal direction.
A jib that is connectable to the front end of the boom and that is raised or turned down with respect to the boom by rotating with respect to the boom about a connection position of the boom to the front end, A jib that can be arranged on the lower surface of the boom along the longitudinal direction of the boom,
A tension rod whose one end is connected to the jib,
A boom-side link whose one end is connectable to the other end of the tension rod and whose other end is connected to the front end portion of the boom on the side closer to the boom upper surface with respect to the connecting position of the jib. , Which is rotatable with respect to the boom about a connection position of the boom to the front end portion, and approaches the front end portion of the boom from the front side by rotation about the connection position. Or a boom side link that separates to the front side,
A jib overhanging device. By lowering the boom until the depression angle with respect to the horizontal direction becomes larger than a predetermined angle, the boom side link becomes in a state of hanging from the connection position to the front end portion of the boom.
The jib overhanging device according to claim 1. In a state where the jib is arranged on the lower surface of the boom along the longitudinal direction, the tension rod is arranged on the side opposite to the side where the boom is located with respect to the jib,
In a state in which the jib is arranged on the bottom surface of the boom along the longitudinal direction and the tension rod is connected to the boom side link, the boom is turned down until the depression angle becomes larger than the predetermined angle, and Corresponding to a state in which the boom side link hangs down from the front end portion of the boom, the tension rod approaches the jib as compared to a state in which the boom is horizontal,
The jib overhanging device according to claim 2. A jib overhanging device according to any one of claims 1 to 3,
With the running body,
A swing base that is connected to the traveling body such that the boom is undulatingly connected, and that the boom and the jib projecting device are swingably connected to the traveling body.
A construction machine equipped with.