JP6632591B2 - crane - Google Patents

Description

  The present invention relates to a crane.

  Patent Literature 1 discloses a crane including a traveling vehicle body and a swing body. In this crane, the rear part of the boom is attached to the swing body, and the boom can be raised and lowered with respect to the swing body. The crane is provided with a long jib, and the jib is stored in the boom in a state of extending along the longitudinal direction of the boom. When using the jib, the jib is rotatably attached to the boom head at the front of the boom. Then, the jib is raised or turned down with respect to the boom by rotating the jib with respect to the boom about the mounting position on the boom head.

  Patent Literature 2 discloses a crane that includes a traveling vehicle body and a revolving superstructure, and has a boom mounted on the revolving superstructure so as to be able to move up and down with respect to the revolving superstructure, as in Patent Literature 1. In this crane, a jib shorter in size than the jib of Patent Document 1 is detachably attached to a boom head at a front portion of the boom as an attachment. When using an attachment (short jib), the attachment can be raised or lowered with respect to the boom by pivoting the attachment relative to the boom about its location on the boom head.

Japanese Patent No. 4204907 Japanese Patent No. 5531769

  There is a need to be able to use both a long jib as described in Patent Document 1 and an attachment such as a searcher hook or a short jib as described in Patent Document 2 with one crane. Here, in a configuration in which both the jib and the attachment can be used by one crane, it is necessary to attach the attachment to the boom head and use the attachment with the jib stored in the boom along the longitudinal direction of the boom. . In this case, it is required that the attachment be easily attached to the boom head while the jib is stored along the boom. In addition, in attaching the attachment to the boom and using the attachment, it is required that interference of the attachment with a jib stored along the boom be prevented.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem, and an object of the present invention is to attach an attachment to a boom easily in a state where the jib is stored along the boom, and to attach the jib to the stored jib. It is an object of the present invention to provide a crane in which interference of the crane is effectively prevented.

In order to achieve the above object, a crane according to an aspect of the present invention is a boom that extends in a longitudinal direction from a rear side to a front side, and is a boom that can be raised and lowered, and has a boom head at a front portion, A first mounting portion protruding outward on the outer surface of the boom head in the width direction of the boom, and a position away from the front with respect to the first mounting portion, or the boom undulating direction; A second mounting portion provided at a position distant from the first mounting portion and protruding outward on the outer surface of the boom head in the width direction of the boom, the dimension of the boom in the width direction. a second attachment portion but smaller than that of the first mounting portion, said together stored in a state of being extended along the longitudinal direction in the boom, before the first attachment portion Is attachable to the projecting portion of the boom head, by rotating relative to the boom about said first mounting portion in a state attached to the first mounting portion, occurs with respect to the boom Or a jib that is turned down and detachably and rotatably mounted on a protruding portion of the second mounting portion from the boom head, and by rotating about the second mounting portion , An attachment that is rotatable with respect to the boom head at the second mounting portion , one end of which is connected to the arm, and the first mounting portion. and wherein by being connected via a separate member to the second directly or between the boom head at a position distant from the mounting portion, the boot Includes head and and a tension link spanned between the arms.

  According to the present invention, it is possible to provide a crane in which the attachment is easily attached to the boom while the jib is stored along the boom, and the interference of the attachment with the stored jib is effectively prevented.

FIG. 1 is a schematic diagram showing a crane according to the first embodiment. FIG. 2 schematically shows a boom head in a state where a searcher hook is attached to the boom head according to the first embodiment and the vicinity thereof, and a start position of the searcher hook in a state where a tension link is stretched. FIG. FIG. 3 schematically shows the boom head with the searcher hook attached to the boom head according to the first embodiment and the vicinity thereof, and the lowest position of the searcher hook with the tension link stretched. FIG. FIG. 4 is a schematic diagram showing the boom head and the vicinity thereof in a state where the searcher hook is attached to the boom head according to the first embodiment, in a state where the tension link is omitted and viewed from the side where the searcher hook occurs. FIG. FIG. 5 is a perspective view schematically showing a part on the side where the boom lays down in the boom head according to the first embodiment. FIG. 6 is a schematic view showing the tension link according to the first embodiment in a most contracted state. FIG. 7 is a schematic diagram showing the tension link according to the first embodiment in the most extended state. FIG. 8 is a perspective view schematically showing a state where a tension link is not stretched in the searcher hook according to the first embodiment. FIG. 9 is a schematic view of the searcher hook according to the first embodiment in a state where the tension link is not stretched, as viewed from one side in the width direction of the arm. FIG. 10 is a perspective view schematically showing a configuration of a distal end portion of the arm according to the first embodiment. FIG. 11 is a schematic diagram showing a state in which the arm is transported to the vicinity of the front part of the boom when the searcher hook according to the first embodiment is attached to the boom head. FIG. 12 is a schematic diagram showing a state in which the arm is attached to the boom head and the tension link is connected to the boom head from the state shown in FIG. FIG. 13 is a schematic diagram showing a state in which the tension link is connected to the tip of the arm from the state of FIG. 12 and the tension link is stretched between the boom head and the tip of the arm. FIG. 14 is a schematic diagram showing a state in which the angle of the arm with respect to the boom is changed from the state of FIG. FIG. 15 is a schematic diagram illustrating an operation of attaching the searcher hook to the boom head in a state where the auxiliary hook is suspended from the boom head according to the first embodiment. FIG. 16 is a schematic diagram showing a state in which the auxiliary hook is suspended from the boom head according to the first embodiment, and the searcher hook is attached to the boom head. FIG. 17 is a schematic diagram showing the boom head and its vicinity in a state where the searcher hook is attached to the boom head according to the first modification. FIG. 18 is a schematic diagram illustrating the movement of the crane in a state where the arm of the searcher hook according to the first modification is fixed to the boom head. FIG. 19 is a schematic diagram illustrating a configuration of a boom head according to a second modification. FIG. 20 is a schematic diagram illustrating a configuration of a boom head according to a third modification.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a diagram illustrating a crane 1 according to the present embodiment. As shown in FIG. 1, the crane 1 includes a traveling vehicle body 2 and a revolving unit 3 disposed on the traveling vehicle body 2 so as to be able to turn with respect to the traveling vehicle body 2. The traveling vehicle body 2 includes a pair of outriggers 4 in total at the front and a pair at the rear. When working with the crane 1, each of the outriggers 4 is brought into contact with the ground to support the traveling vehicle body 2. The revolving superstructure 3 includes an operator cab 5 where the operation of the crane 1 and the like are performed.

  The crane 1 includes a boom 6 extending from the rear side to the front side along the longitudinal direction. The rear part (base end) of the boom 6 is attached to the revolving unit 3. The boom 6 is capable of turning with respect to the traveling body 2 together with the revolving superstructure 3, and is capable of undulating with respect to the revolving superstructure 3. The undulating direction of the boom 6 intersects (vertically or substantially perpendicularly) the longitudinal direction of the boom 6. In addition, a boom head 7 is provided at a front part (tip part) of the boom 6. In the present embodiment, the boom 6 is a multi-stage boom, and is extendable and contractible in the longitudinal direction. Further, in the present embodiment, the boom head 7 protrudes on the boom 6 on the side where the boom 6 lies down. FIG. 1 shows an up-and-down state of the boom, that is, two states in which the angle of the boom 6 with respect to the horizontal direction (up-and-down angle) is different from each other. A state where the boom 6 is at an angle θ1 with respect to the horizontal direction is indicated by a broken line, and a state where the boom 6 is at an angle θ2 larger than the angle θ1 with respect to the horizontal direction is indicated by a solid line.

  The crane 1 includes a jib 10. The jib 10 extends from the base end (one end) to the tip end (the other end) along the longitudinal direction, and has a long dimension in the longitudinal direction. The jib 10 is stored in the boom 6 in a state where the longitudinal direction of the jib 10 is parallel or substantially parallel to the longitudinal direction of the boom 6. That is, the jib 10 is stored in the boom 6 in a state of extending along the longitudinal direction of the boom 6. In the present embodiment, the jib 10 is arranged on the surface 11 facing the prone side of the boom 6 in the stored state, and extends along the boom 6 on the surface 11. That is, the jib 10 is stored in a state where it is held below the boom 6. Further, in the present embodiment, the jib 10 is stored in a state where the distal end side of the jib 10 matches or substantially matches the rear side of the boom 6 and the base end side of the jib 10 matches or substantially matches the front side of the boom 6. Is done.

  Further, the crane 1 is provided with a pair of tension rods 8A and 8B. One end of each of the tension rods 8A, 8B can be connected to the tip of the jib 10. In a state where the jib 10 is stored, the tension rods 8A and 8B are also stored together with the jib 10 along the longitudinal direction of the boom 6. In the crane 1, the searcher hook 13 is detachably attached to the boom head 7 as an attachment separate from the jib 10. In this embodiment, the searcher hook 13 can be attached to the boom head 7 in a state where the jib 10 is stored along the boom 6.

  2 to 4 show the boom head 7 and the vicinity thereof in a state where the searcher hook 13 is attached to the boom head 7. Here, a direction intersecting (vertically or substantially perpendicularly) with the longitudinal direction of the boom 6 and intersecting (vertically or approximately perpendicularly) with the undulating direction of the boom 6 is defined as a width direction of the boom 6. As shown in FIGS. 2 to 4, guide sheaves 15 and 16 are arranged at a portion of the boom head 7 where the boom 6 is raised. In the present embodiment, the guide sheave 16 (guide sheave for auxiliary winding rope) is provided on the front side with respect to the guide sheave (guide sheave for main winding rope) 15. The guide sheave 15 is attached to the boom head 7 via a shaft (guide sheave shaft) 17, and the guide sheave 16 is attached to the boom head 7 via a shaft (guide sheave shaft) 18. Each of the shafts 17 and 18 extends parallel or substantially parallel to the width direction of the boom 6, and each of the guide sheaves 15 and 16 has a boom centered on a corresponding shaft (a corresponding one of the 17 and 18). It is rotatable with respect to the head 7.

  The boom head 7 has a pair of side surfaces 21A and 21B facing outward in the width direction of the boom 6. In each of the side surfaces 21A and 21B, the shaft 18 protrudes outward in the width direction of the boom 6. A pair of boom-side links (permanent links) 22A and 22B are attached to the boom head 7. On each of the side surfaces 21A and 21B of the boom head 7, one end of a corresponding boom-side link (a corresponding one of the 21A and 21B) is connected to the protruding portion of the shaft 18.

  FIG. 5 shows a part of the boom head 7 on the side where the boom 6 is turned down. As shown in FIG. 2 to FIG. 5, a top sheave 23 is disposed on a part of the boom head 7 on the side where the boom 6 lies down. The top sheave 23 is attached to the boom head 7 via a shaft (top sheave shaft) 25. The shaft 25 extends parallel or substantially parallel to the width direction of the boom 6, and the top sheave 23 is rotatable about the shaft 25 with respect to the boom head 7. In the present embodiment, the shaft 25 protrudes outward in the width direction of the boom 6 on each of the side surfaces 21A and 21B.

  Further, a hook-in bracket (main hook accommodating bracket) 26 is attached to a portion of the boom head 7 on the side where the boom 6 lies down. The hook-in bracket 26 is attached to the boom head 7 via a shaft (bracket shaft) 27. The shaft 27 extends parallel or substantially parallel to the width direction of the boom 6, and the hook-in bracket 26 is rotatable about the shaft 27 with respect to the boom head 7. The shaft 27 of the hook-in bracket 26 is disposed away from the shaft 25 of the top sheave 23 on the front side (tip side). In the present embodiment, the shaft 27 protrudes outward in the width direction of the boom 6 on each of the side surfaces 21A and 21B. 2 and 3, the hook-in bracket 26 and the shaft 27 are omitted.

  Further, a rooster 28 protruding forward from the boom 6 is provided at a position on the boom head 7 where the boom 6 is turned down. The rooster 28 is provided on the front side with respect to the shaft 27. Therefore, the shafts 25 and 27 are arranged on the rear side (base end side) with respect to the rooster 28. The rooster 28 is provided with a rooster sheave 31. The rooster sheave 31 is provided on the front side of the boom 6 with respect to the top sheave 23. The rooster sheave 31 is attached to the rooster 28 (boom head 7) via a shaft (rooster sheave shaft) 32. The shaft 32 extends parallel or substantially parallel to the width direction of the boom 6, and the rooster sheave 31 is rotatable about the shaft 32 with respect to the rooster 28. In the present embodiment, the shaft 32 projects outward in the width direction of the boom 6 on each of the side surfaces 21A and 21B. The shaft 32 of the rooster sheave 31 is arranged at a distance away from the shaft 27 of the hook-in bracket 26 on the front side, and is arranged at a distance away from the shaft 25 of the top sheave 23 on the front side.

  A hook-in bracket (supplementary hook housing bracket) 33 is attached to the rooster 28. The hook-in bracket 33 is attached to the rooster 28 (boom head 7) via a shaft (bracket shaft) 35. The shaft 35 extends parallel or substantially parallel to the width direction of the boom 6, and the hook-in bracket 33 is rotatable about the shaft 35 with respect to the rooster 28. The shaft 35 of the hook-in bracket 33 is spaced apart from the shaft 32 of the rooster sheave 31 on the front side. 2 and 3, the hook-in bracket 33 and the shaft 35 are omitted.

  In the operation of the crane 1, a relatively heavy load may be lifted using the main hook 36. In this case, a main winding rope 37 extends from a main winch (not shown) of the revolving unit 3, and the main winding rope 37 extends from the rear side to the front side on the surface 12 facing the side where the boom 6 occurs. You. The main winding rope 37 is hung on the guide sheave 15 and the top sheave 23, and the main hook 36 is suspended from the top sheave 23 via the main winding rope 37. The main hook 36 can be accommodated inside the hook-in bracket 26.

  In the operation of the crane 1, a relatively lightweight suspended load may be lifted using an auxiliary hook (not shown). In this case, an auxiliary hoisting rope 38 (see FIGS. 15 and 16) extends from an auxiliary winch (not shown) of the revolving unit 3, and the auxiliary hoisting rope 38 extends from the rear side on the surface 12 facing the side where the boom 6 occurs. It extends toward the front side. The auxiliary rope 38 is hung on the guide sheave 16 and the rooster sheave 31, and the auxiliary hook is hung from the rooster sheave 31 via the auxiliary rope 38. The auxiliary hook can be accommodated inside the hook-in bracket 33.

  A pair of jib foot (jib engaging portions) 41A and 41B are formed at the base end of the jib 10 in the longitudinal direction. On each of the side surfaces 21A and 21B of the boom head 7, a corresponding jib foot (a corresponding one of 41A and 41B) can be engaged with a protruding portion of a shaft (top sheave shaft) 25. Therefore, the jib 10 can be attached to the boom head 7 at the shaft (first attachment position) 25 of the top sheave 23. In a state where the jib 10 is stored along the longitudinal direction of the boom 6 on the surface 11 (a state where the jib 10 is held down), the jib 10 is fixed to the boom 6 at one or more locations on the rear side with respect to the shaft 25. . When the jib 10 is stored along the boom 6, the jib foots 41A and 41B are not connected to the shaft 25. For this reason, in a state where the jib 10 is stored, the shaft 25 moves forward with respect to the jib foot 41A, 41B by extending the boom 6 in the longitudinal direction, and separates forward from the jib foot 41A, 41B. However, even when the jib 10 is retracted, the boom 6 contracts in the longitudinal direction to the most contracted state or a state close to the most contracted state, whereby the jib foot 41A, 41B engages with the shaft 25, and the jib foot 41A, 41B interferes with (abuts) the shaft 25.

  When the jib 10 is used, the jib foot 41A, 41B is engaged with the shaft 25 of the top sheave 23 from the state of being held down by the boom 6, and the jib 10 is attached to the boom head 7 by the shaft (first attachment position) 25. . Then, the fixing of the jib 10 to the boom 6 at a position other than the shaft 25 is released. Thereby, the jib 10 can be rotated with respect to the boom 6 about the shaft (first mounting position) 25. When the jib 10 is used, one end of each of the tension rods 8A and 8B is connected to the tip of the jib 10. Then, the other end of each of the tension rods 8A, 8B is connected to the boom head 7 via a corresponding boom-side link (a corresponding one of 22A, 22B). Thereby, the tension rods 8A and 8B are stretched between the boom head 7 and the tip of the jib 10. When the jib 10 rotates about the shaft 25 in a state where the tension rods 8A and 8B are stretched, the jib 10 rises or leans against the boom 6.

  In one embodiment, the jib 10 expands or contracts in the longitudinal direction, and the length of the jib 10 in the longitudinal direction changes in accordance with the undulation of the jib 10 with respect to the boom 6. In another embodiment, in response to the undulation of the jib 10 relative to the boom 6, the tension rods 8A, 8B stretched between the boom head 7 and the jib 10 expand or contract to extend the length of the tension rods 8A, 8B. Changes. In some embodiments, the boom-side links 22A and 22B are not provided. In this case, each of the tension rods 8A and 8B is directly connected to the shaft 18 of the guide sheave 16 and directly to the boom head 7.

  The searcher hook 13 as an attachment includes an arm 43, a pair of tension links 45A and 45B, and a hook 46. The arm 43 extends in the longitudinal direction from a base end (one end) to a front end (the other end). The dimension of the arm 43 in the longitudinal direction is shorter than the dimension of the jib 10 in the longitudinal direction, and in the present embodiment, is smaller than half the dimension of the jib 10 in the longitudinal direction. In the searcher hook 13, one end of each of the tension links 45 </ b> A and 45 </ b> B can be connected to the tip of the arm 43. The searcher hook 13 is detachably attached to the boom head 7.

  The arm 43 includes a pair of pillars 47A and 47B. Each of the pillars 47A and 47B extends continuously from the base end to the tip end of the arm 43. Here, when the width direction of the arm 43 intersecting (vertically or substantially perpendicularly) to the longitudinal direction of the arm 43 is defined, the columns 47A and 47B are arranged apart from each other in the width direction of the arm 43. An arm engaging portion 48A is formed at the base end of the column 47A in the longitudinal direction of the arm 43, and an arm engaging portion 48B is formed at the base end of the column 47B in the longitudinal direction of the arm 43. On each of the side surfaces 21A and 21B of the boom head 7, the corresponding arm engaging portion (the corresponding one of 48A and 48B) can be engaged with the protruding portion of the shaft (rooster sheave shaft) 32. Therefore, the searcher hook 13 including the arm 43 can be attached to the boom head 7 (rooster 28) at the shaft (second attachment position) 32 of the rooster sheave 31.

  When the searcher hook 13 is used, the arm engaging portions 48A and 48B are engaged with the shaft 32 of the rooster sheave 31, and the arm 43 (searcher hook 13) can be attached to and detached from the boom head 7 by the shaft (second mounting position) 32. Attach to Therefore, in the present embodiment, the shaft (second mounting position) 32 of the rooster sheave 31 to which the searcher hook 13 is attached to the boom head 7 is the shaft (the first mounting position) of the top sheave 23 to which the jib 10 is attached to the boom head 7. It moves away from the mounting position) 25 to the front side. When the arm 43 is attached to the boom head 7 by the shaft 32, the searcher hook 13 can rotate with respect to the boom 6 about the shaft (second attachment position) 32.

  When the searcher hook 13 is used, one end of each of the tension links 45A and 45B is connected to the tip of the arm 43. Then, the other end of each of the tension links 45A and 45B is connected to the boom head 7 via a corresponding boom-side link (a corresponding one of 22A and 22B). Thereby, the tension links 45A and 45B are stretched between the boom head 7 and the distal end of the arm 43. The rotation of the searcher hook 13 about the shaft 32 causes the searcher hook 13 to be raised or lowered with respect to the boom 6. At this time, the undulating direction of the searcher hook 13 (arm 43) intersects (vertically or substantially perpendicularly) the longitudinal direction of the arm 43 and intersects (vertically or approximately perpendicularly) the width direction of the arm 43. Is).

  Here, in FIG. 2, the searcher hook 13 is shown at the most upmost position where the searcher hook 13 occurs most in a state where the tension links 45A and 45B are stretched. In FIG. 3, the tension links 45A and 45B are stretched. The searcher hook 13 is shown at the lowest position where the searcher hook 13 is most lowered. FIG. 4 shows a state viewed from the side where the searcher hook 13 is raised, that is, from the side where the boom 6 is raised, and the tension links 45A and 45B are omitted. In the present embodiment, the tension links 45A, 45B stretched between the boom head 7 and the arm 43 expand or contract in response to the undulation of the searcher hook 13 with respect to the boom 6, and the length of the tension links 45A, 45B is reduced. Change.

  6 and 7 show the configuration of the tension link 45A. Here, FIG. 6 shows a state where the tension link 45A is most contracted, and FIG. 7 shows a state where the tension link 45A is most expanded. As shown in FIGS. 6 and 7, the tension link 45A includes plates 51A and 52A that extend along the direction in which the tension link 45A expands and contracts. In the present embodiment, the plate 51A forms one end of the tension link 45A in the direction of expansion and contraction. The plate 52A forms the other end of the tension link 45A in the direction of expansion and contraction. The plate 52A is connected to the plate 51A via a pin 53A, and is movable with respect to the plate 51A in the direction of expansion and contraction of the tension link 45A. In the present embodiment, the movement of the plate 52A with respect to the plate 51A causes the tension link 45A to expand or contract. In the present embodiment, one end of the tension link 45A is connected to the tip of the arm 43 by connecting the plate 51A to the tip of the arm 43 via the pin 55A. Further, by connecting the plate 52A to the boom-side link 22A via the pin 56A, the other end of the tension link 45A is connected to the boom head 7 via the boom-side link 22A.

  Further, in the present embodiment, in each of the state where the tension link 45A is most contracted and the state where the tension link 45A is most expanded, the movement of the plate 52A with respect to the plate 51A can be regulated by the pin 57A. The extension of the tension link 45A is regulated by the pin 57A regulating the movement of the plate 52A in the state where the tension link 45A is most contracted. Thereby, the length of the tension link 45A in the expansion and contraction direction is maintained in the most contracted state. Similarly, the contraction of the tension link 45A is regulated by the pin 57A regulating the movement of the plate 52A in a state where the tension link 45A is extended most. Thus, the tension link 45A maintains its length in the expansion and contraction direction in the most extended state.

  The tension link 45B has the same configuration as the tension link 45A. Therefore, the tension link 45B includes plates 51B and 52B similar to the plates 51A and 52A, and pins 53B, 55B, 56B and 57B similar to the pins 53A, 55A, 56A and 57A. In one embodiment, each of the tension links 45A and 45B can maintain a length in the expansion and contraction direction in one or more states other than the most contracted state and the most expanded state. In this case, each of the tension links 45A and 45B can maintain the length in the expansion and contraction direction in three or more states where the expansion and contraction states are different from each other. In the embodiment in which the boom-side links 22A and 22B are not provided, each of the tension links 45A and 45B is directly connected to the shaft 18 of the guide sheave 16 and directly to the boom head 7.

  In the state where the tension links 45A and 45B are stretched, the tension links 45A and 45B are in the most contracted state at the most starting position of the searcher hook 13 shown in FIG. As described above, each of the tension links 45A and 45B can maintain the length in the expansion and contraction direction in the most contracted state. The extension of each of the tension links 45A, 45B is restricted at the most protruding position of the searcher hook 13 in a state where the tension links 45A, 45B are stretched, so that the searcher hook 13 lays down on the boom 6 from the most protruding position. Operation (rotation) is regulated. As a result, the arm 43 is maintained at an angle (offset angle) at the most upmost position of the searcher hook 13 with respect to the boom 6 (the longitudinal direction of the boom 6).

  When the tension links 45A and 45B are stretched, the tension links 45A and 45B are in the most extended state at the lowest position of the searcher hook 13 shown in FIG. As described above, each of the tension links 45A and 45B can maintain the length in the expansion and contraction direction in the most extended state. At the lowest position of the searcher hook 13 with the tension links 45A, 45B being stretched, the contraction of each of the tension links 45A, 45B is regulated, so that the searcher hook 13 with respect to the boom 6 from the lowest position occurs. Operation (rotation) is regulated. Thus, the arm 43 is maintained at an angle (offset angle) at the lowest position of the searcher hook 13 with respect to the boom 6 (the longitudinal direction of the boom 6).

  In one embodiment described above, each of the tension links 45A and 45B can maintain the length in the expansion and contraction direction in one or more states other than the most contracted state and the most expanded state. In this case, in a state where the tension links 45A and 45B are stretched, the arm 43 is provided at one or more positions between the highest position and the lowest position in addition to the highest position and the lowest position of the searcher hook 13. Can be maintained at an angle with respect to the boom 6. That is, in a state where the tension links 45A and 45B are stretched, the angle of the arm 43 with respect to the boom 6 (the longitudinal direction of the boom 6) is changed at three or more positions where the undulations of the searcher hook 13 with respect to the boom 6 are different from each other. Will be sustainable.

  In the present embodiment, the searcher hook 13 is raised at the most start position of the searcher hook 13 in a state where the tension links 45A and 45B are stretched, as compared with the position where the arm 43 is parallel to the longitudinal direction of the boom 6. . Further, at the lowest position of the searcher hook 13 in a state where the tension links 45A and 45B are stretched, the searcher hook 13 is lowered as compared with the position where the arm 43 is parallel to the longitudinal direction of the boom 6. Therefore, in this embodiment, the searcher hook 13 is raised with respect to the boom 6 beyond the position where the arm 43 is parallel to the longitudinal direction of the boom 6, so that the searcher hook 13 is raised to the most up position. In one embodiment, the arm 43 is parallel or substantially parallel to the longitudinal direction of the boom 6 at the lowest position of the searcher hook 13 when the tension links 45A and 45B are stretched. In another embodiment, the lowermost position of the searcher hook 13 in a state where the tension links 45A and 45B are stretched is smaller than the position where the arm 43 is parallel to the longitudinal direction of the boom 6. Hook 13 gets up.

  Further, in an embodiment, in the operation using the searcher hook 13, a processor (not shown) provided in the crane 1 sets an upper limit value of the angle (the undulation angle) of the boom 6 with respect to the horizontal direction. In the present embodiment, the processor sets the upper limit value of the angle of the boom 6 based on the angle (offset angle) of the arm 43 with respect to the longitudinal direction of the boom 6, that is, the up-and-down state of the searcher hook 13 with respect to the boom 6. For example, the angle of the boom 6 at the highest position of the searcher hook 13 when the tension links 45A and 45B are stretched is greater than the lowest position of the searcher hook 13 when the tension links 45A and 45B are stretched. Set a small upper limit for. When the boom 6 exceeds the set upper limit, the processor performs at least one of a warning by a sound or a screen display and an automatic stop of the operation in which the boom 6 occurs. The up-and-down state of the searcher hook 13 including the angle (offset angle) of the arm 43 with respect to the longitudinal direction of the boom 6 may be detected by a sensor or the like, and is provided on the crane 1 or an operating device separate from the crane 1 (Not shown) or the like.

  8 and 9 show the searcher hook 13 in a state where the tension links 45A and 45B are not stretched. FIG. 9 shows a state where the searcher hook 13 is viewed from one side in the width direction of the arm 43. As shown in FIGS. 8 and 9, each tension link 45 </ b> A, 45 </ b> B can be stored in the arm 43 when not stretched between the arm 43 and the boom head 7. In the present embodiment, each of the tension links 45A, 45B is stored in a state where the direction of expansion and contraction of the tension links 45A, 45B is parallel or substantially parallel to the longitudinal direction of the arm 43. That is, each of the tension links 45A, 45B is stored in the arm 43 in a state of extending along the longitudinal direction of the arm 43. Further, in the present embodiment, each of the stored tension links 45A, 45B is maintained in the most contracted state by the pins (one corresponding to 57A, 57B).

  In the present embodiment, even when the tension links 45A and 45B are stored, similarly to the state where the tension links 45A and 45B are stretched between the arm 43 and the boom head 7, each of the tension links 45A and 45B is provided. A plate (a corresponding one of 51A and 51B) is connected to a distal end of the arm 43 via a pin (a corresponding one of 55A and 55B). That is, even when the tension links 45A and 45B are stored, one end of each of the tension links 45A and 45B is connected to the distal end of the arm 43. Further, each of the stored tension links 45A and 45B is disposed on a surface 61 of the arm 43 facing the side where the searcher hook 13 occurs, and extends along the arm 43 on the surface 61.

  In the present embodiment, engagement recesses 62A and 62B are formed on the surface 61 of the arm 43. The engaging recess 62A is formed in the column 47A, and the engaging recess 62B is formed in the column 47B. In addition, each of the engagement recesses 62A and 62B is disposed on the base end side with respect to the connection position of each of the tension links 45A and 45B by the pin (one of the corresponding one of 55A and 55B). Each of the engagement concave portions 62A and 62B is disposed on the distal end side with respect to each of the arm engagement portions 48A and 48B. In each of the tension links 45A and 45B, the plate (the corresponding one of the 52A and 52B) is engaged with the corresponding engagement recess (the corresponding one of the 62A and 62B) in the retracted state. In the present embodiment, in the engagement recess 62A, the tension link 45A engaged with the engagement recess 62A is connected to the arm 43 via the pin 56A. Similarly, in the engagement recess 62B, the tension link 45B engaged with the engagement recess 62B is connected to the arm 43 via the pin 56B. As described above, when the corresponding tension links (one of the corresponding one of 45A and 45B) are set, the pins 56A and 56B respectively connect the boom-side links (22A and 22A) of the tension link (the corresponding one of the 45A and 45B). 22B for connection to the corresponding one).

  FIG. 10 shows the configuration of the distal end of the arm 43. As shown in FIGS. 2, 3, and 8 to 10, a shaft 63 extends continuously between the columns 47 </ b> A and 47 </ b> B at the tip of the arm 43. In the present embodiment, the shaft 63 extends parallel or substantially parallel to the width direction of the arm 43. The shaft 63 is disposed on the distal end side with respect to the connection position of each of the tension links 45A and 45B by pins (corresponding one of 55A and 55B). Further, the shaft 63 protrudes outward with respect to each of the columns 47A and 47B in the width direction of the arm 43. A link 65 is attached to the shaft 63. A hook 46 is detachably attached to the link 65 via a pin 66. When the hook 46 is attached to the link 65, the hook 46 can rotate about the shaft 63 together with the link 65. Note that the hook 46 is rotatable about the pin 66 with respect to the link 65.

  When the searcher hook 13 is used, the hook 46 is suspended from the shaft 63 via the link 65. A bar member 67 extends from the arm 43 between the columns 47A and 47B. The bar member 67 extends parallel or substantially parallel to the width direction of the arm 43. Further, the bar member 67 is disposed on the base end side with respect to the connection position of each of the tension links 45A, 45B by the pins (one corresponding to 55A, 55B), and is disposed on each of the engagement recesses 62A, 62B. It is arranged on the tip side. The bar member 67 is formed with a protruding piece 68 protruding to the side where the searcher hook 13 is raised. The hook 46 can be hooked on the projecting piece 68. In the present embodiment, the hook 46 is stored in the arm 43 while being hooked on the protruding piece 68. When stored, the hook 46 is disposed between the columns 47A and 47B in the width direction of the arm 43. In the state where the hook 46 and the tension links 45A and 45B are stored in the arm 43, the hook 46 is disposed between the tension links 45A and 45B.

  A pair of rollers 69A and 69B are attached to the shaft 63. The roller 69A is attached to the shaft 63 at a portion protruding outward from the column 47A in the width direction, and the roller 69B is attached to the shaft 63 at a portion protruding outward from the column 47B in the width direction. Each of the rollers 69A and 69B is rotatable about a shaft 63. A grip 71 is provided at the base end of the arm 43. The grip 71 is bridged between the columns 47A and 47B, and formed between the columns 47A and 47B in parallel or substantially parallel to the width direction. In addition, the grip 71 is formed in a substantially U-shape that opens to the side where the searcher hook 13 is turned down, and protrudes from the surface 61 of the arm 43 to the side where the searcher hook 13 is raised. The grip 71 is disposed on the base end side with respect to each of the engagement concave portions 62A and 62B, and is disposed on the distal end side with respect to each of the arm engagement portions 48A and 48B. In a state where the tension links 45A and 45B are stored in the arm 43, the grip 71 is disposed on the base end side with respect to each of the tension links 45A and 45B.

  In the present embodiment, in a state where the tension links 45A and 45B and the hook 46 are stored in the arm 43 as described above, the entire searcher hook 13 can be moved integrally as in the carryback. At this time, the operator brings the rollers 69A and 69B into contact with the ground and holds the grip 71. Then, the searcher hook 13 is integrally moved by rotating the rollers 69A and 69B on the ground.

  Next, the operation and effects of the searcher hook 13 and the crane 1 of the present embodiment will be described. When the searcher hook 13 is used, the searcher hook 13 is detachably attached to the boom head 7. As shown in FIG. 11, the attachment of the searcher hook 13 to the boom head 7 is performed in a state where each of the outriggers 4 is grounded to the ground and the boom 6 is laid down in the horizontal direction. For this reason, in the work of attaching the searcher hook 13 to the boom head 7, the boom 6 is inclined with respect to the horizontal direction so as to be vertically downward toward the front. The searcher hook 13 is attached in a state where the jib 10 is retracted (held down) along the longitudinal direction of the boom 6 and the boom 6 is most contracted in the longitudinal direction. For this reason, the work of attaching the searcher hook 13 is performed in a state in which the jib foot 41A, 41B is engaged with the shaft 25 of the top sheave 23 and the jib foot 41A, 41B in the boom head 7 interferes with (abuts) the shaft 25. Done.

  In attaching the searcher hook 13 to the boom head 7, the searcher hook 13 is transported to the vicinity of the front part of the boom 6. In the present embodiment, as described above, in a state where the tension links 45A, 45B and the hook 46 are stored in the arm 43, the entire searcher hook 13 can be integrally moved in the same manner as the carryback. Therefore, the searcher hook 13 can be easily transported to the vicinity of the front part of the boom 6. Further, by moving the components forming the searcher hook 13 integrally, loss of the components forming the searcher hook 13 can be effectively prevented. In the present embodiment, the searcher hook 13 is moved by rotating the rollers 69A and 69B on the ground, and the searcher hook 13 is moved with the hook 46 stored in the arm 43. For this reason, when the searcher hook 13 moves, contact with the ground such as the hook 46 is prevented, and damage to the hook 46 and the like is effectively prevented. The searcher hook 13 is moved to the vicinity of the front part of the boom 6 and the arm 43 is arranged on the ground.

  Then, as shown in FIG. 12, with the rollers 69A, 69B in contact with the ground, the arm engaging portions 48A, 48B of the arm 43 are engaged with the shaft 32 of the rooster sheave 31. Then, the arm 43 is attached to the boom head 7 with the shaft (second attachment position) 32. Here, the shaft 32 of the rooster sheave 31 to which the arm 43 is attached is located on the front side with respect to the portion where the jib foot 41A, 41B of the jib 10 abuts, that is, the shaft (first attachment position) 25 of the top sheave 23. Placed away. Therefore, in attaching the arm 43 to the boom head 7, interference of the arm 43 of the searcher hook 13 with the stored jib 10 is effectively prevented, and the arm 43 is easily attached to the boom head 7. Further, as described above, the work of attaching the searcher hook 13 is performed with the boom 6 turned down in the horizontal direction. Therefore, when the arm 43 is attached to the boom head 7, the shaft 32 of the rooster sheave 31 is located vertically below the shaft 25 of the top sheave 23, and the distance from the ground to the shaft 32 is small. Therefore, it becomes easier to attach the arm 43 to the boom head 7.

  Then, the pins (corresponding ones of 57A and 57B) are removed from each of the tension links 45A and 45B, and each of the tension links 45A and 45B can be extended and contracted. Then, each of the tension links 45A and 45B is connected to a corresponding boom-side link (a corresponding one of the 22A and 22B) via a pin (a corresponding one of the 56A and 56B) in a stretchable state. As a result, each of the tension links 45A and 45B is connected to the boom head 7 (the shaft 18 of the guide sheave 16) via the corresponding boom-side link (the corresponding one of 22A and 22B).

  Then, as shown in FIG. 13, the arm 43 is rotated about the shaft 32 to separate the rollers 69A and 69B from the ground. Then, each of the tension links 45A and 45B is connected to the distal end of the arm 43 via a pin (one corresponding to 55A and 55B). As a result, the tension links 45A and 45B are stretched between the boom head 7 and the distal end of the arm 43.

  Then, by rotating the arm 43 about the shaft 32, the undulating state of the searcher hook 13 with respect to the boom 6, that is, the angle (offset angle) of the arm 43 with respect to the boom 6 is adjusted. At this time, each of the tension links 45A and 45B expands or contracts in accordance with a change in the angle (offset angle) of the arm 43 with respect to the boom 6. Then, when the angle of the arm 43 with respect to the boom 6 is adjusted, pins (corresponding ones of 57A and 57B) are attached to each of the tension links 45A and 45B. Accordingly, the extension and contraction of each of the tension links 45A and 45B is regulated, and the length of each of the tension links 45A and 45B in the expansion and contraction direction is maintained. Therefore, the angle of the arm 43 with respect to the boom 6 is maintained at the adjusted angle. Then, the hook 46 is attached to the arm 43 in a state where the angle of the arm 43 with respect to the boom 6 is maintained at the adjusted angle. The removal of the searcher hook 13 from the boom head 7 is performed in a procedure reverse to the procedure for attaching the searcher hook 13 to the boom head 7.

  As shown in FIG. 14, when changing the angle (offset angle) of the arm 43 with respect to the boom 6, the hook 46 is removed from the arm 43. Then, the pins (corresponding ones of 57A and 57B) are removed from each of the tension links 45A and 45B, and each of the tension links 45A and 45B can be extended and contracted. By rotating the arm 43 about the shaft 32 in this state, the undulation state of the searcher hook 13 with respect to the boom 6, that is, the angle of the arm 43 with respect to the boom 6 is changed. At this time, each of the tension links 45A and 45B expands or contracts in accordance with a change in the angle (offset angle) of the arm 43 with respect to the boom 6. Then, when the angle of the arm 43 with respect to the boom 6 is changed to an appropriate angle, a pin (one of 57A and 57B) is attached to each of the tension links 45A and 45B. Accordingly, the extension and contraction of each of the tension links 45A and 45B is regulated, and the length of each of the tension links 45A and 45B in the expansion and contraction direction is maintained. Therefore, the angle of the arm 43 with respect to the boom 6 is maintained at the changed angle. Then, the hook 46 is attached to the arm 43 while the angle of the arm 43 with respect to the boom 6 is maintained at the changed angle.

  As described above, the shaft (the second attachment position) 32 to which the arm 43 is attached is disposed at a position separated from the shaft (the first attachment position) 25 of the top sheave 23 on the front side. Therefore, even when the arm 43 is rotated about the shaft 32 in the adjustment and change of the angle (offset angle) of the arm 43 with respect to the boom 6, the interference of the arm 43 of the searcher hook 13 with the stored jib 10 is effective. Is prevented. In addition, the shaft (second mounting position) 32 to which the arm 43 is mounted is disposed at a position separated from the shaft 25 of the top sheave 23 and the shaft 27 of the hook-in bracket 26 on the front side. When the arm 43 rotates, interference of the arm 43 with the side surfaces 21A and 21B of the boom head 7 and components attached to the side surfaces 21A and 21B is effectively prevented. Therefore, the searcher hook 13 can be easily rotated with respect to the boom 6.

  Further, by disposing the shaft 32 to which the arm 43 is attached to the front side away from the shafts 25 and 27, the dimension of the arm 43 in the longitudinal direction can be reduced. Further, in the rooster 28 in which the shaft 32 of the rooster sheave 31 is provided, the dimension in the width direction of the boom 6 is smaller than that of the portion in which the shaft 25 of the top sheave 23 is provided (see FIG. 4). For this reason, by mounting the arm 43 to the boom head 7 with the shaft 32, it is possible to reduce the dimension of the arm 43 in the width direction. By reducing the size of the arm 43 in the longitudinal direction and the size of the arm 43 in the width direction, the searcher hook 13 including the arm 43 is reduced in size and weight. Thereby, the attachment of the searcher hook 13 including the arm 43 to the boom head 7 is further facilitated, and the searcher hook 13 can be moved more easily.

  Further, in the present embodiment, even if the jib 10 is stored on the surface 11 facing the side on which the boom 6 faces down, that is, even if the jib 10 is stored with the boom 6 held down, Interference between 10 and the searcher hook (attachment) 13 is effectively prevented. For this reason, the jib 10 is stored in a state in which the jib 10 is arranged on a surface (one of 14A and 14B) of the boom 6 that faces outward in the width direction, that is, in a state where the jib 10 is held horizontally with respect to the boom 6. No need. Therefore, when the jib 10 is used, it is not necessary to change the jib 10 from the laterally held state to the downwardly held state before connecting the jib 10 to the shaft 25 or the like of the top sheave 23 from the downwardly held state. For this reason, the jib 10 is easily attached to the boom head 7. Similarly, when the jib 10 is stored, it is not necessary to set the jib 10 in the state of being held down, and then to change from the state of holding down to the state of being held horizontally. Therefore, the jib 10 is easily stored.

  When the searcher hook 13 is attached to the boom head 7 and the angle of the arm 43 with respect to the boom 6 is adjusted as described above, a suspended load (W1 or W2, etc.) is pulled on the hook 46 as shown in FIG. Hook and raise the boom 6 with respect to the swing body 3. Thus, the suspended load (W1 or W2, etc.) is lifted by the searcher hook 13. The searcher hook 13 is used for lifting a suspended load in a work environment where the sky is restricted such as indoors. Here, in the searcher hook 13, the hook 46 is suspended from the shaft 63 of the arm 43 via only the link 65, and no rope or the like is used for suspending the hook 46. For this reason, even when lifting a suspended load in a work environment where the sky is restricted, the distance from the distal end of the arm 43 to the lower end of the hook 46 is reduced, thereby increasing the lift of the crane 1 (from the ground to the lower end of the hook 46). Large).

  When the searcher hook 13 is used, the working environment such as the height (H 1 or H 2) to the ceiling (T 1 or T 2), the up-and-down state of the boom 6, etc. The angle (offset angle) with respect to the boom 6, that is, the undulating state of the searcher hook 13 is adjusted. At this time, the angle of the arm 43 with respect to the boom 6 is adjusted so that the lift of the crane 1 is maximized according to the working environment and the up-and-down state of the boom 6. For example, when the height is H1 to the ceiling and the boom 6 is at an angle θ1 with respect to the horizontal direction, the arm 43 is located at the highest position when the tension links 45A and 45B are stretched with respect to the boom 6. Adjusted to the position. When the height H2 is higher than the height H1 to the ceiling and the boom 6 has an angle θ2 larger than the angle θ1 with respect to the horizontal direction, the arm 43 moves the tension links 45A and 45B with respect to the boom 6. Is adjusted to the lowermost position in the state where is stretched.

  In one embodiment described above, the processor sets the upper limit value of the angle of the boom 6 based on the state of the searcher hook 13 undulating with respect to the boom 6. Then, when the boom 6 occurs beyond the set upper limit, the processor performs at least one of a warning and an automatic stop of the operation in which the boom 6 occurs. In this case, the angle of the boom 6 (the undulation angle) can be adjusted to an appropriate range based on the undulation state of the searcher hook 13 with respect to the boom 6, and the work is performed with the boom 6 adjusted to an appropriate angle.

  When the searcher hook 13 is attached to the boom head 7 and work is performed, if a supplementary hook (not shown) is suspended from the rooster sheave 31 via the supplementary rope 38, the supplementary hook is provided near the searcher hook 13. Since the hook is located, the auxiliary hook may interfere with the searcher hook 13. Therefore, before attaching the searcher hook 13 to the boom head 7, the auxiliary hook needs to be removed from the boom head 7. In the present embodiment, as shown in FIG. 15, when the auxiliary hook is suspended, that is, when the auxiliary hook is mounted on the boom head 7, the arm 43 is connected to the shaft of the rooster sheave 31 (the second mounting position). ) 32, the grip 71 of the searcher hook 13 interferes with the auxiliary rope 38 from the front side of the boom 6. At this time, the grip 71 interferes with the auxiliary rope 38 between the guide sheave 16 and the rooster sheave 31. When the grip 71 interferes with the auxiliary rope 38, the rotation of the arm 43 is restricted. As a result, the tension links 45A and 45B cannot be connected to the distal end of the arm 43, and the searcher hook 13 cannot be properly attached to the boom head 7.

  In a state where the auxiliary hook is disposed on the ground and the auxiliary rope 38 is loose, the grip 71 may not interfere with the auxiliary rope 38, and the searcher hook 13 may be attached to the boom head 7. There is. However, in this case, when the boom 6 is raised and the auxiliary hook separates from the ground, the auxiliary rope 38 is in a stretched state. Thus, as shown in FIG. 16, the grip 71 interferes with the auxiliary hoisting rope 38 from the front side of the boom 6. For this reason, the auxiliary | assistant hoist rope 38 cannot be extended and wound up appropriately, and the operator recognizes that both the auxiliary hook and the searcher hook 13 are attached to the boom head 7. In FIG. 16, the searcher hook 13 is indicated by the highest position when the tension links 45A and 45B are stretched and the lowest position when the tension links 45A and 45B are stretched. The position is indicated by a solid line, and the lowest position is indicated by a broken line.

  As described above, in the present embodiment, when the searcher hook 13 is attached to the boom head 7 while the auxiliary hook is suspended, the grip 71 interferes with the auxiliary winding rope 38. Thereby, the worker recognizes that both the searcher hook 13 and the auxiliary hook are attached to the boom head 7. Therefore, the continuation of the operation using the searcher hook 13 while the auxiliary hook is suspended is effectively prevented.

(Modification)
In the first modification shown in FIGS. 17 and 18, the searcher hook 13 is not provided with the grip 71. In the present modified example, in a state where the tension links 45A and 45B are not stretched, the arm 43 may further occur as compared with the most initial position (X1) in a state where the tension links 45A and 45B are stretched. It is possible. Also in this modification, the tension links 45A and 45B and the hook 46 are stored in the arm 43 in the same manner as in the above-described embodiment and the like. Then, in a state where the tension links 45A and 45B are stored, the arm 43 can be further raised with respect to the boom 6 as compared with the highest position (X1) in a state where the tension links 45A and 45B are stretched. It is. Note that, in FIG. 17, the most upright position (X1) and the lowest position (X2) of the arm 43 when the tension links 45A and 45B are stretched are indicated by broken lines.

  In this modification, the arm 43 is raised with respect to the boom 6 in a state where the tension links 45A and 45B are stored, so that the tension links 45A and 45B respectively correspond to the corresponding relay links (72A and 72B). One) can be connected to the corresponding boom-side link (the corresponding one of 22A and 22B). Each of the tension links 45A and 45B is connected to a corresponding relay link (a corresponding one of 72A and 72B) via a pin (a corresponding one of the 56A and 56B). Each of the tension links 45A and 45B stored in the arm 43 is connected to the shaft 18 of the boom head 7 via a relay link (corresponding one of 72A and 72B) and a boom-side link (corresponding one of 22A and 22B). Thereby, the arm 43 is fixed to the boom head 7. At this time, the arm 43 is fixed to the boom head 7 at a position further raised from the most initial position (X1) in a state where the tension links 45A and 45B are stretched. That is, in a state where the tension links 45A and 45B are not stretched, the arm 43 is further raised from the most initial position (X1) in a state where the tension links 45A and 45B are stretched. Can be fixed.

  FIG. 17 shows a state in which the arm 43 is fixed to the boom head 7 by a solid line. When the tension links 45A and 45B are stretched, the relay links 72A and 72B are stored in, for example, the arm 43. Also, the boom side links 22A and 22B are not provided, and the tension links 45A and 45B stored in the arm 43 are connected to the boom head 7 via only the relay links (one of the corresponding ones of the 72A and 72B). You may.

  In the present modified example, the tension links 45A, 45B and the hook 46 are stored in the arm 43 and the arm 43 is fixed to the boom head 7 as shown in FIG. Thus, the crane 1 can be moved. For example, when moving from the work point to the next work point in the work site, the tension links 45A and 45B and the hook 46 are stored in the arm 43, and the arm 43 is fixed to the boom head 7. The crane 1 is moved. At this time, the crane 1 is moved in a state where each of the outriggers 4 is separated from the ground and the boom 6 is turned down in the horizontal direction. The tension links 45A, 45B and the hook 46 are stored in the arm 43, and the crane 1 can be moved in a state where the arm 43 is fixed to the boom head 7, so that the crane 1 can be moved in the work site. There is no need to remove the hook 13 from the boom head 7, and it is not necessary to transport the searcher hook 13 separately from the crane 1. Therefore, workability in the work using the searcher hook 13 is improved.

  Further, in the present modification, the arm 43 is further raised when the arm 43 is fixed to the boom head 7 as compared with the highest position when the tension links 45A and 45B are stretched. For this reason, when the crane 1 is moved with the tension links 45A, 45B and the hook 46 stored in the arm 43 and the arm 43 fixed to the boom head 7, the arm 43 from the boom 6 is moved. It is possible to reduce the amount of protrusion to the front side.

  Also in this modification, the shaft 32 to which the arm 43 is attached is disposed away from the shafts 25 and 27 on the front side, so that the dimension of the arm 43 in the longitudinal direction can be reduced. Therefore, when the arm 43 is fixed to the boom head 7, the amount of protrusion of the arm 43 from the boom head 7 vertically upward (on the side where the boom 6 occurs) can be reduced. Therefore, when the crane 1 is moved in a state where the tension links 45A and 45B and the hook 46 are stored in the arm 43 and the arm 43 is fixed to the boom head 7, the field of view from the cab 5 is reduced. Blocking by the arm 43 is prevented, and contact of the arm 43 with an obstacle around the crane 1 is also effectively prevented.

  In a modification, the arm 43 of the searcher hook 13 is rotatably mounted on the boom head 7 by a shaft (second mounting position) 27 of a hook-in bracket 26 instead of the shaft 32 of the rooster sheave 31. Can be Also in this case, the shaft 27 to which the arm 43 is attached is disposed at a position separated from the shaft (first attachment position) 25 of the top sheave 23 that can be engaged with the jib 10 on the front side. For this reason, also in this modification, interference with the jib 10 in which the searcher hook 13 including the arm 43 is stored is effectively prevented.

  In another modification, when the jib 10 is used, the jib 10 is attached to the boom head 7 by a shaft (first attachment position) 27 of a hook-in bracket 26 instead of the shaft 25 of the top sheave 23. It is mounted to be rotatable. However, in this modification, the arm 43 of the searcher hook 13 is rotatably attached to the boom head 7 by the shaft 32 of the rooster sheave 31, as in the first embodiment. In this case as well, the shaft 32 to which the arm 43 is attached is disposed away from the shaft (first attachment position) 27 that can be engaged with the jib 10 on the front side. For this reason, also in this modification, interference with the jib 10 in which the searcher hook 13 including the arm 43 is stored is effectively prevented.

  In the second modification shown in FIG. 19, in the boom head 7, the shaft 73 extends parallel or substantially parallel to the width direction of the boom 6. In each of the side surfaces 21A and 21B, the shaft 73 protrudes outward in the width direction of the boom 6. The shaft 73 is spaced apart from the shaft 17 of the guide sheave 15 and the shaft 18 of the guide sheave 16 on the side on which the boom 6 lies down. Further, the shaft 73 is disposed on the side where the boom 6 is raised with respect to each of the shaft 25 of the top sheave 23, the shaft 27 of the hook-in bracket 26, and the shaft 32 of the rooster sheave 31. Therefore, the shaft 73 is arranged apart from each of the shafts 25, 27, 32 in the up-and-down direction of the boom 6.

  In this modification, when the jib 10 is used, the jib 10 is rotatably attached to the boom head 7 by a shaft (first attachment position) 73. The arm 43 of the searcher hook 13 is turned to the boom head 7 by one of the shaft 25 of the top sheave 23, the shaft 27 of the hook-in bracket 26, and the shaft 32 of the rooster sheave 31 (second mounting position). Movably mounted. In this modification, the shaft (any one of 25, 27, and 32) to which the arm 43 is attached is moved up and down with respect to the shaft (first attachment position) 73 that can be engaged with the jib 10. About to be placed apart. Therefore, also in this modified example, similarly to the above-described embodiment and the like, interference of the searcher hook 13 including the arm 43 with the stored jib 10 is effectively prevented.

  In a modification, when the jib 10 is used, the jib 10 is attached to any one of the shaft 25 of the top sheave 23, the shaft 27 of the hook-in bracket 26, and the shaft 32 of the rooster sheave 31 (the first mounting position). ), It is rotatably attached to the boom head 7. The arm 43 of the searcher hook 13 is rotatably attached to the boom head 7 by a shaft (second attachment position) 73. Also in this case, the shaft 73 to which the arm 43 is attached is arranged away from the shaft (any one of 25, 27, and 32) engageable with the jib 10 in the up-and-down direction of the boom 6. Therefore, also in this modified example, similarly to the above-described embodiment and the like, interference of the searcher hook 13 including the arm 43 with the stored jib 10 is effectively prevented.

  In the third modification shown in FIG. 20, a shaft 73 is provided on the boom head 7 as in the second modification. However, in this modification, the rooster 28 is detachable from the boom head 7. The rooster 28 is attached to the boom head 7 at a rooster connection part 75. In the present modified example, the rooster connection part 75 is provided at a part of the boom head 7 on the side where the boom 6 is turned down, and forms a part of the front end face of the boom 6. The rooster 28 removed from the boom head 7 may be able to be stored in one of the side surfaces 21A and 21B of the boom head 7.

  In this modification, when the jib 10 is used, the jib 10 is rotatably attached to the boom head 7 by a shaft (first attachment position) 73. The arm 43 of the searcher hook 13 is rotatably attached to the boom head 7 by a shaft (second attachment position) 25 of the top sheave 23. In the present modified example, the shaft 25 to which the arm 43 is attached is arranged apart from the shaft (first attachment position) 73 that can be engaged with the jib 10 in the up-and-down direction of the boom 6. Therefore, also in this modification, similarly to the above-described embodiments and the like, the interference of the searcher hook 13 including the arm 43 with the stored jib 10 is effectively prevented.

  In a modification, the rooster 28 is detachable from the boom head 7, and when the jib 10 is used, the jib 10 is attached to the boom head 7 by the shaft (first mounting position) 25 of the top sheave 23. To be rotatable. The arm 43 of the searcher hook 13 is rotatably attached to the boom head 7 by a shaft (second attachment position) 73. Also in this case, the shaft 73 to which the arm 43 is attached is arranged away from the shaft 25 engageable with the jib 10 in the up-and-down direction of the boom 6. Therefore, also in this modified example, similarly to the above-described embodiment and the like, interference of the searcher hook 13 including the arm 43 with the stored jib 10 is effectively prevented.

  In a modification, instead of the searcher hook 13, a jib having a shorter dimension in the longitudinal direction than the jib 10 is detachably attached to the boom head 7 as an attachment. In this case, in a state where the short jib is attached to the boom head 7, for example, an auxiliary hook is hung from an end portion of the short jib via the auxiliary rope 38. In this modification, the attachment position of the short jib to the boom head 7 relative to the attachment position of the jib 10 to the boom head 7 is different from the attachment position of the searcher hook 13 to the boom head 7 relative to the attachment position of the jib 10 to the boom head 7. Same as any of the mounting positions. For this reason, interference of the short jib as the attachment to the stored jib 10 is effectively prevented.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be variously modified in an implementation stage without departing from the scope of the invention. In addition, the embodiments may be implemented in appropriate combinations as much as possible, in which case the combined effects can be obtained. Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriate combinations of a plurality of disclosed constituent elements.

  DESCRIPTION OF SYMBOLS 1 ... Crane, 2 ... Car body, 6 ... Boom, 7 ... Boom head, 10 ... Jib, 13 ... Searcher hook, 23 ... Top sheave, 25, 27, 32, 73 ... Shaft, 26 ... Hook-in bracket, 31 ... Rooster sheave, 43 ... arm, 45A, 45B ... tension link, 46 ... hook.

Claims (3)

A boom that is extended along the longitudinal direction from the rear side to the front side and that can be raised and lowered, and a boom including a boom head at a front portion,
A first mounting portion projecting outward on an outer surface of the boom head in a width direction of the boom;
The boom is provided at a position away from the first mounting portion with respect to the first mounting portion, or at a position away from the first mounting portion with respect to the up-and-down direction of the boom. A second mounting portion protruding from the outer surface of the head, wherein a size of the boom in the width direction is smaller than that of the first mounting portion;
The boom is stored in a state of being extended along the longitudinal direction and is attachable to a protruding portion of the first attaching portion from the boom head , and is attached to the first attaching portion. A jib that rises or lays down on the boom by rotating with respect to the boom about the first mounting portion .
Attachment which is detachably and rotatably attached to a protruding portion of the second attachment portion from the boom head and which pivots around the second attachment portion to raise or lie down on the boom. When,
With
The attachment is
An arm rotatably mounted to the boom head at the second mounting portion ;
One end is connected to the arm, and the boom head is connected to the boom head at a position separated from the first mounting portion and the second mounting portion directly or via another member therebetween. A tension link stretched between the arm and the arm;
A crane. The tension link changes in length in response to undulation of the attachment relative to the boom,
At the most prominent position where the attachment occurs most in a state where the tension link is stretched, the attachment occurs compared to a position where the arm is parallel to the longitudinal direction of the boom.
The crane of claim 1. In a state where the tension link is not stretched, the arm can be further raised as compared with the most upright position in a state where the tension link is stretched,
In a state where the tension link is not stretched, the arm can be fixed to the boom head at a position further raised from the most upright position in a state where the tension link is stretched,
The crane of claim 2.