Overwinding detection device for construction machinery and construction machinery

Abstract

To provide an overwinding detector capable of properly preventing a detector from coming off the front end of a boom or a jib without complicating the configuration of a detector mounting position.SOLUTION: A hook is suspended from the front end of a boom or of a jib via a wire rope in an overwinding detector, and on the outer peripheral surface of a shaft where the detector is attached, a retaining member protrudes to the side where the detector is located. A shaft can be inserted into the holes in a first pipe at the boom front end and in a second pipe at the jib front end, and the holes are opened toward the outer circumference in an axial cutout and a circumferential cutout. In the first pipe and the second pipe, the axial cutout is formed along the axial direction and the circumferential cutout is formed along the circumferential direction from one extended end of the axial cutout only over some angular range in the circumferential direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an overwind detection device for detecting overwinding of a wire rope in a construction machine, and a construction machine including the overwind detection device.

Background Art

[0002] Patent Document 1 discloses a crane including a boom that can be raised and lowered, and a jib rotatably attached to the front end of the boom, as a construction machine. During operation with this crane, a hook (sub-hook) is suspended from the front end of the boom or the front end of the jib via a wire rope (rewinding wire rope). Further, in the crane, in a state where the hook is suspended from the front end of the boom or the front end of the jib, an overwind detection device detects overwinding of the wire rope. The overwind detection device includes a weight and a detector in addition to the hook and the wire rope. The weight is suspended from the front end of the boom or the front end of the jib in a state of being located vertically above the hook. The detector is attached to the front end of the boom or the front end of the jib and outputs a detection signal indicating a detection result regarding overwinding of the wire rope. Then, when the hook is lifted by winding the wire rope and the hook pushes up the weight from the vertically lower side, a detection signal indicating that overwinding of the wire rope has occurred is output from the detector.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a construction machine provided with an overwind detection device as in the above Patent Document 1, it is required to appropriately prevent the detector from coming off (being removed) from the front end of the boom or the front end of the jib during work or the like, and to appropriately attach the detector to the front end of the boom or the front end of the jib. Further, it is required to appropriately prevent the detector from coming off from the front end of the boom or the front end of the jib without complicating the configuration of the attachment position of the detector at each of the front end of the boom and the front end of the jib.

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide an overwind detection device that appropriately prevents the detector from coming off from the front end of the boom or the front end of the jib without complicating the configuration of the attachment position of the detector, and a construction machine equipped with the overwind detection device.

Means for Solving the Problems

[0006] To achieve the above object, an overwind detection device for a construction machine according to an aspect of the present invention includes a wire rope, a hook suspended via the wire rope from the front end of a boom that can be raised and lowered, or the front end of a jib rotatably attached to the front end of the boom, a detector that outputs a detection signal indicating a detection result regarding overwind of the wire rope in a state where the hook is suspended, a shaft to which the detector is attached, a retaining member protruding toward the side where the detector is located on the outer peripheral surface of the shaft, a first pipe provided at the front end of the boom and having a hole into which the shaft can be inserted formed along the axial direction, and a second pipe provided at the front end of the jib and having a hole into which the shaft can be inserted formed along the axial direction. Axial notches and circumferential notches that open the holes toward the outer peripheral side are formed in each of the first pipe and the second pipe. In each of the first pipe and the second pipe, the axial notch is formed along the axial direction from a first extended end located at one end in the axial direction to a second extended end, and the circumferential notch is formed along the circumferential direction from the second extended end of the axial notch and is formed only over a partial angular range in the circumferential direction. In the second pipe, the angular range in which the circumferential notch is formed is larger than the angular range in which the circumferential notch is formed in the first pipe 。

Advantages of the Invention

[0007] According to the present invention, it is possible to provide an overwind detection device that appropriately prevents the detector from coming off from the front end of the boom or the front end of the jib without complicating the configuration of the mounting position of the detector. Further, it is possible to provide a construction machine including the overwind detection device.

Brief Description of the Drawings

[0008]

Figure 1

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Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described with reference to the drawings.

[0010] First, as an example of a construction machine according to an embodiment, a crane according to the first embodiment will be described. The crane includes a traveling vehicle body and a slewing body. The slewing body is connected to the traveling vehicle body from above in the vertical direction and is slewingable with respect to the traveling vehicle body about a slewing axis along the vertical direction. Further, in the crane, the rear end portion of the boom is attached to the slewing body. The boom pivots about the attachment position to the slewing body, thereby rising or falling with respect to the slewing body. For this reason, the boom is capable of rising and falling. Further, the boom is slewingable with respect to the traveling vehicle body together with the slewing body. Further, in the crane, a jib is attached to the front end portion of the boom. The jib is rotatable about the attachment position to the boom. When the jib rotates about the attachment position to the boom from a state where the jib hangs vertically downward from the front end portion of the boom, the jib is swung forward of the boom. Therefore, the jib is capable of rising and falling with respect to the boom.

[0011] Figure 1 shows the configuration of the boom 1 of the crane. As shown in Figure 1, in the boom 1, a longitudinal direction (the directions indicated by arrow X1 and arrow X2), a heaving direction (the directions indicated by arrow Y1 and arrow Y2) that intersects (is orthogonal or substantially orthogonal) to the longitudinal direction, and a width direction (the directions indicated by arrow W1 and arrow W2) that intersects (is orthogonal or substantially orthogonal) to both the longitudinal direction and the heaving direction are defined. In the boom 1, the dimension along the longitudinal direction is larger than each of the dimension along the heaving direction and the dimension along the width direction. Also, in an example of Figure 1, the boom 1 is a multi-stage boom and is extendable and retractable in the longitudinal direction.

[0012] A boom head 2 is provided at the front end of the boom 1. A top sheave 3 and guide sheaves 5, 6 are attached to the boom head 2. The top sheave 3 is arranged on the side where the boom 1 is lowered (arrow Y2 side) with respect to the guide sheaves 5, 6. Each of the top sheave 3 and the guide sheaves 5, 6 is rotatable about a rotation axis along the width direction of the boom 1. Also, the top sheave 3 is attached to the boom head 2 via a shaft 7, and the central axis of the shaft 7 is coaxial or substantially coaxial with the rotation axis of the top sheave 3. The shaft 7 has a protruding portion that protrudes outward in the width direction of the boom 1 on the outer surface of the boom head 2, and the aforementioned jib is rotatably attached to the protruding portion of the shaft 7. Then, the jib rotates with respect to the boom 1 about the central axis of the shaft 7 or substantially about the central axis.

[0013] A loose pulley bracket 8 is attached to the boom head 2. In the boom head 2, the loose pulley bracket 8 is attached to the end on the side where the boom 1 is lowered, and the loose pulley bracket 8 is located on the side where the boom 1 is lowered with respect to the guide sheaves 5, 6. Also, the loose pulley bracket 8 protrudes forward (arrow X1 side) of the boom 1 from the boom head 2. A loose pulley sheave 10 is attached to the loose pulley bracket 8. The loose pulley sheave 10 is located on the side where the boom 1 is lowered with respect to the guide sheaves 5, 6 and on the front side of the boom 1 with respect to the top sheave 3. The loose pulley sheave 10 is rotatable about a rotation axis P1 along the width direction of the boom 1.

[0014] In a crane, a main hoist winch and a supplementary hoist winch (both not shown) are provided on a slewing body. During operations using the crane or the like, a wire rope (main hoist wire rope) 11 is paid out from the main hoist winch, and a wire rope (supplementary hoist wire rope) 12 is paid out from the supplementary hoist winch. Then, each of the wire ropes 11 and 12 extends from the rear side toward the front side along the outer surface on the lifting side of the boom 1. During operations using the boom 1 or the like, the wire rope 11 is hung on the guide sheave 5 and the top sheave 3 in this order, and a hook (main hook) 13 shown in FIGS. 8 and 10 described later is suspended from the top sheave 3 via the wire rope 11. Further, the wire rope 12 is hung on the guide sheave 6 and the luffing sheave 10 in this order, and a hook (sub hook) 15 is suspended from the luffing sheave 10 via the wire rope 12. Therefore, the hook 15 is suspended from the front end portion of the boom 1 via the wire rope 12. Note that the hook 13 is used for operations such as lifting a relatively heavy load, and the hook 15 is used for operations such as lifting a relatively light load.

[0015] Further, a hook bracket 16 is attached to the boom head 2, and a hook bracket 17 is attached to the luffing bracket 8. The attachment position of the hook bracket 16 to the boom head 2 is on the front side of the boom 1 with respect to the rotation axis of the top sheave 3 and on the rear side of the boom 1 with respect to the rotation axis P1 of the luffing sheave 10. And the hook bracket 16 is rotatable about the attachment position to the boom head 2, and the rotation axis of the hook bracket 16 is along the width direction of the boom 1.

[0016] Further, the attachment position of the hook-in bracket 17 to the loop tab bracket 8 is on the front side of the boom 1 with respect to the rotation axis P1 of the loop sheave 10 and on the side where the boom 1 lies down with respect to the rotation axis P1. The hook-in bracket 17 is rotatable about the attachment position to the loop tab bracket 8, and the rotation axis of the hook-in bracket 17 extends along the width direction of the boom 1. The hook 13 can be stored in the hook-in bracket 16, and the hook 15 can be stored in the hook-in bracket 17. The hook-in bracket 17 includes a bottom plate 18. When the hook 15 is stored in the hook-in bracket 17, the hook 15 presses the hook-in bracket 17 from the side where the bottom plate 18 is located. The rotation axis P3 of the hook-in bracket 17 at the attachment position to the loop tab bracket 8 will be shown in FIGS. 5 to 7 and the like described later.

[0017] In addition, the crane is provided with an overwind detection device 20. The overwind detection device 20 detects overwind of the wire rope 12 when the hook 15 is suspended from the front end portion (loop sheave 10) of the boom 1. The overwind detection device 20 includes a weight 21 and a detector 22 in addition to the hook 15 and the wire rope 12. The weight 21 is suspended from the front end portion of the boom 1 in a state of being located vertically above the hook 15 (the side where the boom 1 rises). In the present embodiment, the weight 21 is suspended from the hook-in bracket 17 via two suspension ropes 25 and 26. The weight 21 is formed in a ring shape, and the wire rope 12 is inserted through the weight 21. When the weight 21 is suspended from the hook-in bracket 17, one end of each of the suspension ropes 25 and 26 is connected to the weight 21. The other end of the suspension rope 25 is connected to the detector 22, and the other end of the suspension rope 26 is connected to the hook-in bracket 17.

[0018] In this embodiment, a pipe (first pipe) 27 is formed on the hook-in bracket 17, and the detector 22 is attached to the hook-in bracket 17 by the pipe 27. For this reason, the detector 22 is attached to the front end portion of the boom 1. And the pipe 27, which is the attachment position of the detector 22 to the boom 1, is located on the front side of the boom 1 with respect to the rotation axis P1 of the luffing sheave 10 and on the side where the boom 1 lies down with respect to the rotation axis P1. The detector 22 is, for example, a limit switch and outputs a detection signal indicating a detection result regarding overwinding of the wire rope 12. When the hook 15 is lifted by winding of the wire rope 12, the hook 15 may push up the weight 21 from the vertically lower side. In this case, since the tension from the suspension rope 25 no longer acts on the detector 22, the operating state of the detector 22 changes. Thereby, a detection signal indicating that overwinding of the wire rope 12 has occurred is output from the detector 22.

[0019] FIG. 2 shows the configuration of the jib 31 of the crane. As shown in FIG. 2, in the jib 31, a longitudinal direction (the directions indicated by the arrows X3 and X4), a luffing direction (the directions indicated by the arrows Y3 and Y4) that intersects (is orthogonal or substantially orthogonal) to the longitudinal direction, and a width direction (the directions indicated by the arrows W3 and W4) that intersects (is orthogonal or substantially orthogonal) to both the longitudinal direction and the luffing direction are defined. In the jib 31, the dimension along the longitudinal direction is larger than each of the dimension along the luffing direction and the dimension along the width direction. Further, the jib 31 is attached to the shaft 7 (the front end portion of the boom 1) in a state where the width direction of the jib 31 coincides or substantially coincides with the width direction of the boom 1.

[0020] A sheave (jib top sheave) 32 is attached to the front end of the jib 31. The sheave 32 is rotatable about a rotation axis P2 along the width direction of the jib 31. During operations using the boom 1 and the jib 31, etc., the wire rope (rewinding wire rope) 12 extends from the front end of the boom 1 to the jib 31, and the wire rope 12 extends along the outer surface on the rising side of the jib 31 from the rear side toward the front side. And during operations using the boom 1 and the jib 31, etc., the wire rope 12 is hung on the sheave 32, and the hook (sub-hook) 15 is suspended from the sheave 32 via the wire rope 12. Therefore, the hook 15 is suspended from the front end of the jib 31 via the wire rope 12. Also, a cord reel 33 is provided at the front end of the jib 31.

[0021] The overwind detection device 20 detects overwind of the wire rope 12 even when the hook 15 is suspended from the front end of the jib 31 (sheave 32). In this case, the weight 21 is suspended from the front end of the jib 31 in a state of being located vertically above the hook 15 (the side where the jib 31 rises). And the weight 21 is suspended from the front end of the jib 31 via two suspension ropes 25, 26, and the wire rope 12 is inserted through the weight 21. Even when the weight 21 is suspended from the front end of the jib 31, one end of each of the suspension ropes 25, 26 is connected to the weight 21. And the other end of the suspension rope 25 is connected to the detector 22, and the other end of the suspension rope 26 is connected to the front end of the jib 31.

[0022] In this embodiment, a pipe (second pipe) 35 is formed at the front end of the jib 31, and the detector 22 is attached to the front end of the jib 31 by the pipe 35. The pipe 35 at the attachment position of the detector 22 to the jib 31 is on the front side of the jib 31 with respect to the rotation axis P2 of the sheave 32 and on the side where the jib 31 lies down with respect to the rotation axis P2. Further, the pipe 35 is on the front side of the jib 31 with respect to the cord reel 33 and on the side where the jib 31 lies down with respect to the cord reel 33. Even when the hook 15 is suspended from the front end of the jib 31, if the hook 15 is lifted by winding the wire rope 12, the hook 15 may push up the weight 21 from the vertically lower side. Also in this case, the operating state of the detector 22 changes because the tension does not act on the detector 22 from the suspension rope 25. Thereby, a detection signal indicating that overwinding of the wire rope 12 has occurred is output from the detector 22.

[0023] FIG. 3 shows the attachment structure of the detector 22 to the front end of the boom 1, that is, the attachment structure of the detector 22 to the pipe (first pipe) 27, and FIG. 4 shows the pipe 27 provided at the front end of the boom 1 as viewed from the arrow A1 side in FIG. 3. As shown in FIG. 3 and the like, the overwinding detection device 20 includes a shaft 41 to which the detector 22 is attached. The detector 22 is attached to the pipe 27 with the shaft 41 interposed therebetween. The shaft 41 has a central axis C0, and in the shaft 41, the direction along the central axis C0 is defined as the axial direction. The detector 22 is attached to one end of the shaft 41 in the axial direction, and the detector 22 is located away from the shaft 41 in a direction intersecting (orthogonal or substantially orthogonal) to the axial direction. Further, a regulating member 42 is fixed to the shaft 41. The regulating member 42 regulates the rotation of the detector 22 with respect to the shaft 41 about the axis of the central axis C0 of the shaft 41 (circumferential direction of the shaft 41). Therefore, the angular position of the detector 22 with respect to the shaft 41 about the axis of the central axis C0 does not change or hardly changes.

[0024] Further, a retaining member 43 such as a retaining pin is fixed to the shaft 41. The retaining member 43 is located away from the detector 22 in the axial direction of the shaft 41. The retaining member 43 projects to the outer peripheral side of the shaft 41 on the outer peripheral surface of the shaft 41 and projects toward the side where the detector is located. Therefore, the retaining member 43 is located at the same or substantially the same angular position as the detector 22 about the axis of the central axis C0 of the shaft 41 and is not displaced or hardly displaced with respect to the detector 22 about the axis of the central axis C0.

[0025] As shown in FIGS. 3 and 4 and the like, the pipe (first pipe) 27 has a central axis C1. In the pipe 27, the direction along the central axis C1 is defined as the axial direction. The central axis C1 of the pipe 27 extends along the width direction of the boom 1, and a hole 51 is formed in the pipe 27 along the central axis C1. The hole 51 has an opening 52 that opens to the outside of the pipe 27 toward one side in the axial direction of the pipe 27, and the hole 51 opens at the opening 52 toward the outside in the width direction of the boom 1. Further, in the pipe 27, the opening 52 of the hole 51 is formed at one end in the axial direction. The shaft 41 can be inserted into the hole 51 from the opening 52.

[0026] In addition, axial notches 53 and circumferential notches 55 are formed in the pipe 27. The holes 51 open toward the outer peripheral side of the pipe 27 at each of the axial notches 53 and the circumferential notches 55. In the pipe 27, the axial notch 53 is formed along the axial direction (central axis C1) and extends from the extended end (first extended end) E1 to the extended end (second extended end) E2. In the pipe 27, the extended end E1 is located at one end in the axial direction, that is, the end on the side where the opening 52 is formed in the axial direction. Further, in the hook-in bracket 17, the axial notch 53 is located on the side opposite to the side where the bottom plate 18 is located with respect to the central axis C1 of the pipe 27, and the axial notch 53 is located at an angular position shifted 180° or approximately 180° from the bottom plate 18 about the axis of the central axis C1. And in the axial notch 53, the hole 51 opens toward the side where the attachment position of the hook-in bracket 17 to the loop tab bracket 8 is located. Note that the positional relationship between the axial notch 53 and the attachment position of the hook-in bracket 17 to the loop tab bracket 8 and the like are shown in detail in FIGS. 5 to 7 and the like described later.

[0027] The circumferential notch 55 is connected to the extended end E2 of the axial notch 53. And the circumferential notch 55 is formed along the circumferential direction (around the axis of the central axis C1) of the pipe 27 from the extended end E2 of the axial notch 53. For this reason, the circumferential notch 55 is located away from the opening 52 in the axial direction of the pipe 27. The circumferential notch 55 is formed only over a partial angular range in the circumferential direction of the pipe 27, for example, extends only over a first angular range around the axis of the central axis C1. The first angular range is, for example, 180°. In the circumferential notch 55, a receiving portion 57 is formed by the pipe 27 at the end opposite to the side connected to the axial notch 53. In the hook-in bracket 17, the receiving portion 57 is located at an angular position shifted 180° or approximately 180° from the axial notch 53 about the axis of the central axis C1 and is located at the same or approximately the same angular position as the bottom plate 18. Note that the positional relationship between the receiving portion 57 and the axial notch 53 is shown in detail in FIGS. 9 and 11 and the like described later.

[0028] The attachment structure of the detector 22 to the front end of the jib 31, that is, the attachment structure of the detector 22 to the pipe (second pipe) 35, is also the same as the attachment structure of the detector 22 to the front end of the boom 1. For this reason, the pipe (second pipe) 35 has a central axis C2. In the pipe 35, the direction along the central axis C2 is defined as the axial direction. The central axis C2 of the pipe 35 is along the width direction of the jib 31. In the pipe 35, a hole 61 is formed along the central axis C2. The hole 61 has an opening 62 that opens to the outside of the pipe 35 toward one side in the axial direction of the pipe 35. The hole 61 opens at the opening 62 toward the outside in the width direction of the jib 31. Also, in the pipe 35, the opening 62 of the hole 61 is formed at one end in the axial direction. The shaft 41 can be inserted into the hole 61 from the opening 62.

[0029] An axial notch 63 and a circumferential notch 65 are formed in the pipe 35. The hole 61 opens toward the outer peripheral side of the pipe 35 at each of the axial notch 63 and the circumferential notch 65. In the pipe 35, the axial notch 63 is formed along the axial direction (central axis C2) and extends from an extended end (first extended end) E3 to an extended end (second extended end) E4. In the pipe 35, the extended end E3 is located at one end in the axial direction, that is, the end on the side where the opening 62 is formed in the axial direction.

[0030] The circumferential notch 65 is connected to the extended end E4 of the axial notch 63. The circumferential notch 65 is formed along the circumferential direction of the pipe 35 (around the axis of the central axis C2) from the extended end E4 of the axial notch 63. Therefore, the circumferential notch 65 is located away from the opening 62 in the axial direction of the pipe 35. The circumferential notch 65 is formed only over a partial angular range in the circumferential direction of the pipe 35, for example, it extends only over a second angular range around the axis of the central axis C2. Here, the second angular range is larger than the first angular range. For this reason, the angular range in which the circumferential notch 65 is formed in the pipe 35 is larger than the angular range in which the circumferential notch is formed in the pipe 27. The second angular range is, for example, 225°. In the circumferential notch 65, a receiving portion 67 is formed by the pipe 35 at the end opposite to the side connected to the axial notch 63.

[0031] Also, the rotation angle of the jib 31 from the state where the jib 31 hangs vertically downward from the front end portion of the boom 1 to the state where the jib 31 is most raised with respect to the boom 1 is defined as the reference rotation angle. The above-described second angular range is larger than the reference rotation angle. Also, at the front end portion of the jib 31, the receiving portion 67 is located on the rear side of the jib 31 with respect to the central axis C2 of the pipe 35. And the receiving portion 67 is not displaced or hardly displaced with respect to the central axis C2 in the raising and lowering direction of the jib 31. Also, at the front end portion of the jib 31, the axial notch 63 is located on the front side of the jib 31 with respect to the central axis C2 and on the side where the jib 31 rises with respect to the central axis C2 (arrow Y3 side). For example, assuming the above-described second angular range is 225° and a virtual line extending from the central axis C2 toward the front side of the jib 31 is defined. In this case, the axial notch 63 is located at an angular position 45° or approximately 45° away from the virtual line on the side where the jib 31 rises around the axis of the central axis C2. The positional relationship among the central axis C2, the axial notch 63, and the receiving portion 67 is shown in detail in FIGS. 13, 15, 17, etc. described later.

[0032] Also, the pipe (second pipe) 35 and the components related to the pipe 35 are indicated by reference numerals with parentheses in FIGS. 3 and 4. However, the second angular range in which the circumferential notch 65 extends in the circumferential direction of the pipe 35 is larger than the first angular range in which the circumferential notch 55 extends in the circumferential direction of the pipe 27 shown in FIGS. 3 and 4.

[0033] Next, the attachment of the detector 22 to the front end of the boom 1, that is, the attachment of the detector 22 to the pipe 27, will be described with reference to FIGS. 5 to 7. In FIGS. 5 to 7, the rotation axis P3 of the hook-in bracket 17 centered on the attachment position to the loose tab bracket 8 is shown. The rotation axis P3 extends along the width direction of the boom 1 as described above. When attaching the detector 22 to the pipe 27, as shown in FIG. 5, the shaft 41 is inserted into the hole 51 from the opening 52 of the pipe 27 (arrow B1). At this time, with the central axis C0 of the shaft 41 being coaxial or substantially coaxial with the central axis C1 of the pipe 27, the shaft 41 is inserted into the hole 51 from the end on the side opposite to the attachment position of the detector 22 in the axial direction. Further, the shaft 41 is inserted into the hole 51 in a state where the retaining member 43 and the detector 22 are located at the same or substantially the same angular position as the axial notch 53 about the axes of the central axes C0 and C1 (the circumferential direction of the shaft 41 and the pipe 27). Therefore, by inserting the shaft 41 into the hole 51, the retaining member 43 moves along the axial direction of the shaft 41 and the pipe 27 from the extending end E1 to the extending end E2 along the axial notch 53.

[0034] Then, as shown in FIG. 6, when the shaft 41 is inserted into the hole 51 until the retaining member 43 is positioned at the extended end E2 of the axial notch 53, the shaft 41 is rotated relative to the pipe 27 in the circumferential direction (around the axes C0, C1 of the central axes) of the shaft 41 and the pipe 27 (arrow B2). As a result, the retaining member 43 moves the circumferential notch 55 along the circumferential direction of the shaft 41 and the pipe 27 from the extended end E2 of the axial notch 53. Then, as shown in FIG. 7, with the shaft 41 rotated relative to the pipe 27 around the axes C0, C1 from the state of FIG. 6, the detector 22 is electrically connected via the cable 38 to a connector or the like provided on the boom 1. As a result, the detector 22 can output the aforementioned detection signal to a controller or the like of the crane. In the present embodiment, from the state of FIG. 6 to the state of FIG. 7, the shaft 41 is rotated 180° or approximately 180° relative to the pipe 27 around the axes C0, C1. Further, the mounting of the detector 22 to the front end portion of the boom 1 is performed with the hook-in bracket 17 hanging vertically downward from the mounting position to the loose tab bracket 8.

[0035] In the state of FIG. 7, the retaining member 43 is positioned away from the axial notch 53 in the circumferential direction of the shaft 41 and the pipe 27. In the present embodiment, the retaining member 43 is positioned 180° or approximately 180° away from the axial notch 53 in the circumferential direction of the shaft 41 and the pipe 27. For this reason, in the state of FIG. 7, the movement of the retaining member 43 toward the side where the opening 52 is located in the axial direction is restricted. As a result, the shaft 41 is appropriately prevented from coming out (being removed) from the pipe 27, and the detector 22 is appropriately prevented from coming out (being removed) from the front end portion (pipe 27) of the boom 1. Further, in the present embodiment, by simply forming the axial notch 53 and the circumferential notch 55 in the pipe 27, the detector 22 is prevented from coming out of the pipe 27 as described above. Therefore, the detector 22 is appropriately prevented from coming out from the front end portion of the boom 1 without complicating the configuration of the pipe 27 at the mounting position of the detector 22.

[0036] The mounting of the detector 22 to the front end of the jib 31, that is, the mounting of the detector 22 to the pipe 35, is also performed in the same manner as the mounting of the detector 22 to the pipe 27. That is, when mounting the detector 22 to the pipe 35, with the central axis C0 of the shaft 41 being coaxial or substantially coaxial with the central axis C2 of the pipe 35, the shaft 41 is inserted into the hole 61 from the opening 62 of the pipe 35. At this time, the shaft 41 is inserted into the hole 61 in a state where the retaining member 43 and the detector 22 are located at the same or substantially the same angular position as the axial notch 63 in the circumferential direction around the central axes C0 and C2 (the circumferential direction of the shaft 41 and the pipe 35). Thereby, the retaining member 43 moves along the axial direction of the shaft 41 and the pipe 35 from the extended end E3 to the extended end E4 of the axial notch 63.

[0037] Then, when the shaft 41 is inserted into the hole 61 until the retaining member 43 is positioned at the extended end E4 of the axial notch 63, the shaft 41 is rotated relative to the pipe 35 in the circumferential direction around the central axes C0 and C2 (the circumferential direction of the shaft 41 and the pipe 35). Thereby, the retaining member 43 moves the circumferential notch 65 along the circumferential direction of the shaft 41 and the pipe 35 from the extended end E4 of the axial notch 63. And in a state where the shaft 41 is rotated relative to the pipe 35 around the central axes C0 and C2, the detector 22 is electrically connected to a connector or the like provided on the jib 31 via the cable 38. Note that the mounting of the detector 22 to the front end of the jib 31 is performed in a state where the jib 31 hangs vertically downward from the front end (shaft 7) of the boom 1 shown in FIG. 12 or the like described later. At this time, for example, when the aforementioned second angular range is 225°, the shaft 41 is rotated 45° or approximately 45° relative to the pipe 35 around the central axes C0 and C2 from the state where the retaining member 43 is positioned at the extended end E4 of the axial notch 63 (see FIG. 13 or the like described later).

[0038] As described above, in the state where the detector 22 is attached to the pipe 35 (the front end portion of the jib 31), the retaining member 43 is positioned away from the axial notch 63 in the circumferential direction of the shaft 41 and the pipe 35. For this reason, in the state where the detector 22 is attached to the pipe 35, the movement of the retaining member 43 toward the side where the opening 62 is located in the axial direction is restricted. Thereby, the shaft 41 is appropriately prevented from coming off (being removed) from the pipe 35, and the detector 22 is appropriately prevented from coming off (being removed) from the front end portion (pipe 35) of the jib 31. Further, in the present embodiment, by simply forming the axial notch 63 and the circumferential notch 65 in the pipe 35, the detector 22 is prevented from coming off from the pipe 35 as described above. Therefore, the detector 22 is appropriately prevented from coming off from the front end portion of the jib 31 without complicating the configuration of the pipe 35 at the attachment position of the detector 22.

[0039] Next, the rotation range of the detector 22 in the circumferential direction of the shaft 41 and the pipe (first pipe) 27 in the state where the detector 22 is attached to the front end portion of the boom 1 will be described with reference to FIGS. 8 to 11. FIG. 8 shows a state where the hook (sub-hook) 15 is suspended from the front end portion of the boom 1 and the hook 15 is located away from the hook bracket 17 on the vertically lower side. In the state of FIG. 8, the boom 1 extends horizontally or substantially horizontally from the front end to the rear end. And FIG. 9 shows a state of viewing the shaft 41 and the pipe (first pipe) 27 from one side in the axial direction in the state of FIG. 8. FIG. 10 shows a state where the hook (sub-hook) 15 is stored in the hook bracket 17 and the hook 15 is pressing the hook bracket 17 from the side where the bottom plate 18 is located. In the state of FIG. 10, the boom 1 extends to a state where it is located on the vertically lower side as it goes toward the front side. In FIG. 10, a state where the boom 1 is further lowered from the state of extending horizontally from the front end to the rear end is shown. And FIG. 11 shows a state of viewing the shaft 41 and the pipe (first pipe) 27 from one side in the axial direction in the state of FIG. 10.

[0040] In FIGS. 9 and 11, the angular range (the first angular range) in which the circumferential notch 55 is formed about the axes of the central axes C0 and C1 is indicated by the dashed line α1. Also, in FIGS. 9 and 11, the directions indicated by the arrows V1 and V2 are the vertical directions, with the arrow V1 side being the vertically upper side and the arrow V2 side being the vertically lower side. Further, in FIGS. 9 and 11, a virtual line H0 is shown. The virtual line H0 passes through the central axes C0 and C1 along the extending direction of the hook-in bracket 17 from the mounting position (rotation axis P3) of the hook-in bracket 17 to the bottom plate 18 on the loop tab bracket 8. In FIGS. 9 and 11, one side (arrow H1 side) in the direction along the virtual line H0 is the side where the rotation axis P3 is located, and the other side (arrow H2 side) in the direction along the virtual line H0 is the side where the bottom plate 18 is located. Also, in FIGS. 9 and 11, the directions of the arrow R1 in the clockwise direction and the arrow R2 in the counterclockwise direction are defined about the axes of the central axes C0 and C1. Further, in FIGS. 9 and 11, the angular position of the receiving portion 57 about the axes of the central axes C0 and C1 is shown.

[0041] In a state where the hook 15 is suspended from the front end portion of the boom 1 in the state of FIG. 8 or the like, the hook 15 does not press the hook-in bracket 17, and the weight 21 is suspended from the hook-in bracket 17 as described above. For this reason, in a state where the hook 15 is suspended from the front end portion of the boom 1 in the state of FIG. 8 or the like, due to the weight of the hook-in bracket 17 and the force acting downward in the vertical direction from the weight 21 and the suspension ropes 25 and 26, the hook-in bracket 17 hangs downward in the vertical direction from the mounting position (rotation axis P3) on the loop tab bracket 8. In a state where the hook-in bracket 17 hangs downward in the vertical direction from the rotation axis P3, the bottom plate 18 of the hook-in bracket 17 is located on the vertically lower side with respect to the central axis C1 of the pipe 27. Also, as shown in FIG. 9 and the like, in a state where the hook-in bracket 17 hangs downward in the vertical direction from the rotation axis P3, the axial notch 53 is located on the vertically upper side with respect to the central axis C1, and the hole 51 of the pipe 27 opens upward in the vertical direction in the axial notch 53. And the virtual line H0 extends along the vertical direction.

[0042] Also, in the aforementioned state where the hook 15 and the weight 21 are suspended from the front end of the boom 1 in the state shown in FIG. 8, etc., due to the self-weight of the detector 22 and the force acting vertically downward from the suspension cable 25, etc., the detector 22 is biased to a state of hanging vertically downward from the shaft 41. For this reason, the detector 22 is positioned vertically downward with respect to the shaft 41, and the angle position of the shaft 41 with respect to the pipe 27 about the axes of the central axes C0, C1 is biased to a state where the retaining member 43 protrudes vertically downward. Therefore, the shaft 41 is biased to a state of being positioned at the angular position shown in FIG. 9 with respect to the pipe 27 about the axes of the central axes C0, C1.

[0043] In addition, in the state shown in FIG. 9, a circumferential notch 55 is formed in the angular range of 180° or approximately 180° indicated by the dashed line α1. For this reason, the retaining member 43 is movable along the circumferential notch 55 in the direction of the arrow R1 from the state shown in FIG. 9. For this reason, in the state shown in FIG. 9, when a force is applied by an operator or the like, the shaft 41 rotates in the direction of the arrow R1 against the biasing force with respect to the pipe 27. Also, in the state shown in FIG. 9, the retaining member 43 abuts against the receiving portion 57 of the pipe 27 and is not movable in the direction of the arrow R2. For this reason, in the state shown in FIG. 9, even when a force is applied by an operator or the like, the shaft 41 does not rotate in the direction of the arrow R2.

[0044] Also, when the hook 15 is stored in the hook-in bracket 17 as in the state of FIG. 10, as described above, the hook 15 presses the hook-in bracket 17 from the side where the bottom plate 18 is located. Therefore, when the hook 15 is stored in the hook-in bracket 17, the hook-in bracket 17 rotates in the direction of arrow T1 about the rotation axis P3 from the state of hanging vertically downward from the attachment position (rotation axis P3) to the loose tab bracket 8. At this time, the pipe 27, the shaft 41, and the detector 22 also rotate about the rotation axis P3 together with the hook-in bracket 17. As described above, when the hook-in bracket 17 rotates, the hook-in bracket 17 inclines with respect to the vertical direction in a state where the lower part in the vertical direction is located more on the rear side of the boom 1. As described above, when the hook-in bracket 17 inclines, in the hook-in bracket 17, the part farther from the loose tab bracket 8 (rotation axis P3) is located more on the rear side of the boom 1.

[0045] Also, when the hook 15 is stored in the hook-in bracket 17 as in the state of FIG. 10, since the hook-in bracket 17 inclines as described above, the virtual line H0 inclines with respect to the vertical direction. And, as shown in FIG. 11 etc., when the hook 15 is stored in the hook-in bracket 17, the axial notch 53 is located vertically above and on the front side of the boom 1 with respect to the central axis C1. Even when the hook 15 is stored in the hook-in bracket 17, the detector 22 is biased to hang vertically downward from the shaft 41. However, in the state of FIG. 11, the retaining member 43 abuts against the receiving portion 57 of the pipe 27 and cannot move in the direction of arrow R2. Therefore, in the state of FIG. 11, the shaft 41 cannot rotate in the direction of arrow R2, and the shaft 41 does not rotate about the axis of the central axis C0 until the detector 22 hangs vertically downward from the shaft 41 even by the above-described biasing.

[0046] As described above, in this embodiment, when the hook 15 is stored in the hook-in bracket 17, the shaft 41 does not rotate from the state shown in FIG. 11 until the detector 22 hangs vertically downward from the shaft 41. Therefore, when the hook 15 is stored in the hook-in bracket 17 and the crane is running, it is effectively prevented that the detector 22 swings forward beyond the front end of the boom 1 to the front side of the boom 1. Thereby, when the crane is running or the like, it is effectively prevented that the overall length of the crane in the longitudinal direction of the traveling vehicle body becomes longer due to the swing of the detector. Therefore, in this embodiment, when the detector 22 is mounted on the front end portion of the boom 1, the rotation range of the detector 22 in the circumferential direction of the shaft 41 and the pipe (first pipe) 27 is appropriately restricted.

[0047] Next, with reference to FIGS. 12 to 17, the rotation range of the detector 22 in the circumferential direction of the shaft 41 and the pipe (second pipe) 35 in a state where the detector 22 is mounted on the front end portion of the jib 31 will be described. FIG. 12 shows a state where the jib 31 hangs vertically downward from the front end portion of the boom 1. And FIG. 13 shows a state where the shaft 41 and the pipe (second pipe) 35 are viewed from one side in the axial direction in the state of FIG. 12. Further, FIG. 14 shows a state where the jib 31 extends horizontally or substantially horizontally from the rear end to the front end. And FIG. 15 shows a state where the shaft 41 and the pipe (second pipe) 35 are viewed from one side in the axial direction in the state of FIG. 14. Further, FIG. 16 shows a state where the jib 31 is raised most with respect to the boom 1. And FIG. 17 shows a state where the shaft 41 and the pipe (second pipe) 35 are viewed from one side in the axial direction in the state of FIG. 16. The jib 31 can be raised and lowered between the state of FIG. 12 and the state of FIG. 16, and becomes the state of FIG. 14 between the state of FIG. 12 and the state of FIG. 16.

[0048] In FIGS. 13, 15, and 17, the angular range (second angular range) in which the circumferential notch 65 is formed about the axes of the central axes C0 and C2 is indicated by the dashed line α2. Also, in FIGS. 13, 15, and 17, the directions indicated by the arrows V1 and V2 are in the vertical direction, with the arrow V1 side being the upper vertical side and the arrow V2 side being the lower vertical side. Further, in FIGS. 13, 15, and 17, a virtual line J0 is shown. The virtual line J0 extends along the longitudinal direction of the jib 31 and passes through the central axes C0 and C2. In FIGS. 13, 15, and 17, one side in the direction along the virtual line J0 is the front side (arrow X3 side) of the jib 31, and the other side in the direction along the virtual line J0 is the rear side (arrow X4 side) of the jib 31. Also, in FIGS. 13, 15, and 17, the directions along the arrows Y3 and Y4 are shown as the undulating direction of the jib 31. Then, in FIGS. 13, 15, and 17, the directions of the arrow R3 in the counterclockwise direction and the arrow R4 in the clockwise direction about the axes of the central axes C0 and C2 are defined. Also, in the following description, the aforementioned second angular range is set to 180° + θ. θ is an acute angle, for example, 45°. Further, in FIGS. 13, 15, and 17, the angular positions of the receiving portions 67 about the axes of the central axes C0 and C2 are shown.

[0049] Even when the detector 22 is attached to the front end portion (pipe 35) of the jib 31, the detector 22 is biased to hang vertically downward from the shaft 41. For this reason, the detector 22 is positioned vertically below the shaft 41 with respect to the shaft 41, and the angle position of the shaft 41 with respect to the pipe 35 about the axes of the central axes C0 and C2 is biased to a state where the retaining member 43 protrudes vertically downward. Therefore, when the shaft 41 is inserted into the hole 61 of the pipe 35 as described above in a state where the jib 31 hangs vertically downward from the front end portion of the boom 1 shown in FIG. 12, the shaft 41 rotates in the direction of arrow R3 about the axes of the central axes C0 and C2. At this time, the retaining member 43 moves in the direction of arrow R3 from the angular position where the axial notch 63 is located to the angular position shown in FIG. 13 in the circumferential direction of the shaft 41 and the pipe 35, and moves by an acute angle θ. As a result, the retaining member 43 protrudes vertically downward in the shaft 41. Further, in the state shown in FIG. 13 and the like, the receiving portion 67 of the pipe 35 is positioned vertically above the central axes C0 and C2 and is located at an angular position 180° or approximately 180° away from the retaining member 43 about the axes of the central axes C0 and C2.

[0050] When the jib 31 is swung forward from the state where the jib 31 hangs down from the front end of the boom 1 as shown in FIG. 12 or the like, the jib 31 shown in FIG. 14 is in a state of extending horizontally or substantially horizontally. By raising the jib 31 from the state of FIG. 12 to the state of FIG. 14, as shown in FIGS. 13 and 15 or the like, the pipe 35 rotates about the central axes C0 and C2 with respect to the shaft 41 in the direction of arrow R3. As a result, the position of the retaining member 43 in the circumferential notch 65 changes. For example, by raising the jib 31 from the state of FIG. 12 to the state of FIG. 14, the pipe 35 rotates 90° or substantially 90° in the direction of arrow R3 from the state of FIG. 13. Even when the jib 31 is in a state of extending horizontally, since the detector 22 is biased downward vertically from the shaft 41, the retaining member 43 protrudes downward vertically on the shaft 41. Further, when the jib 31 is in a state of extending horizontally, the receiving portion 67 of the pipe 35 is not displaced or hardly displaced in the vertical direction with respect to the central axes C0 and C2. And the receiving portion 67 is located at an angular position 90° or substantially 90° away from the retaining member 43 about the central axes C0 and C2.

[0051] When the jib 31 is further raised from the state where the jib 31 extends horizontally as shown in FIG. 14 or the like, the jib 31 shown in FIG. 16 is in the most raised state. By raising the jib 31 from the state of FIG. 14 to the state of FIG. 16, as shown in FIGS. 15 and 17 or the like, the pipe 35 rotates about the central axes C0 and C2 with respect to the shaft 41 in the direction of arrow R3. As a result, the position of the retaining member 43 in the circumferential notch 65 changes. Further, when the jib 31 is in the most raised state, the retaining member 43 abuts against the receiving portion 67 of the pipe 35 and cannot move in the direction of arrow R4. For this reason, in the state of FIG. 17, even if a force is applied by an operator or the like, the shaft 41 does not rotate in the direction of arrow R4. Even when the jib 31 is in the most raised state, since the detector 22 is biased downward vertically from the shaft 41, the retaining member 43 protrudes downward vertically on the shaft 41. Further, when the jib 31 is in the most raised state, the receiving portion 67 of the pipe 35 is located vertically below with respect to the central axes C0 and C2.

[0052] As described above, by forming the circumferential notch 65 in the pipe 35, in any state from the state where the jib 31 is lowered to the state where the jib 31 is fully raised, the retaining member 43 is located at an angular position away from the axial notch 63 in the circumferential direction of the shaft 41 and the pipe 35. For this reason, in each of the operations of raising the jib 31 and lowering the jib 31, the detachment of the detector 22 from the jib 31 is more reliably prevented. Further, the second angular range in which the circumferential notch 65 is formed is larger than the rotation angle (reference rotation angle) of the jib 31 from the state where the jib 31 is lowered to the state where the jib 31 is fully raised. For this reason, in any state from the state where the jib 31 is lowered to the state where the jib 31 is fully raised, the retaining member 43 projects downward vertically on the shaft 41, and the detector 22 hangs downward vertically from the shaft 41.

[0053] Also, in the present embodiment, as described above, in the state where the jib 31 is fully raised, the shaft 41 does not rotate in the direction of arrow R4 from the state of FIG. 17. Therefore, in the state of FIG. 16 and the like, the rotation of the detector 22 toward the side where the cord reel 33 is located about the central axes C0 and C2 is restricted. Thereby, interference of the detector 22 with peripheral devices provided at the front end portion of the jib 31 such as the cord reel 33 is effectively prevented. As described above, in the present embodiment, in the state where the detector 22 is attached to the front end portion of the jib 31, the rotation range of the detector 22 in the circumferential direction of the shaft 41 and the pipe (second pipe) 35 is appropriately restricted.

[0054] In the above-described embodiments and the like, the crane has been described as an example. However, for a construction machine including a boom and a jib, the structure of the attachment position of each detector at the front end portion of the boom and the front end portion of the jib can be formed in the same manner as in the above-described embodiments and the like.

[0055] Note that the invention of the present application is not limited to the above-described embodiments, and various modifications can be made without departing from the gist thereof at the implementation stage. Also, each embodiment may be implemented in an appropriate combination as much as possible, and in that case, the combined effects can be obtained. Furthermore, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriate combinations of a plurality of disclosed constituent elements.

Description of Reference Numerals

[0056] 1... boom, 2... boom head, 8... loose tab bracket, 10... loose tab sieve, 12... rope (complementary winding rope), 15... hook (sub-hook), 17... hook-in bracket, 18... bottom plate, 20... overwind detection device, 21... weight, 22... detector, 25, 26... sling, 27... pipe (first pipe), 31... jib, 32... sheave (jib top sheave), 35... pipe (second pipe), 41... shaft, 43... retaining member, 51, 61... hole, 52, 62... opening, 53, 63... axial notch, 55, 65... circumferential notch, 57, 67... receiving portion.

Claims

1. A wire rope, a hook suspended via the wire rope from the front end of a boom that can be raised and lowered, or from the front end of a jib rotatably attached to the front end of the boom, a detector that outputs a detection signal indicating a detection result regarding overwinding of the wire rope in a state where the hook is suspended, a shaft to which the detector is attached, a retaining member protruding toward the side where the detector is located on the outer peripheral surface of the shaft, a first pipe provided at the front end of the boom, in which a hole into which the shaft can be inserted is formed along the axial direction, a second pipe provided at the front end of the jib, in which a hole into which the shaft can be inserted is formed along the axial direction, comprising: In each of the first pipe and the second pipe, an axial notch and a circumferential notch that open the hole toward the outer peripheral side are formed, In each of the first pipe and the second pipe, the axial notch is formed along the axial direction from a first extended end located at one end in the axial direction to a second extended end, the circumferential notch is formed along the circumferential direction from the second extended end of the axial notch, and is formed only over a partial angular range in the circumferential direction, An angular range in which the circumferential notch is formed in the second pipe is larger than an angular range in which the circumferential notch is formed in the first pipe, An overwinding detection device for a construction machine.

2. The overwinding detection device according to Claim 1, the boom that can be raised and lowered, comprising: The boom includes: a boom head provided at the front end of the boom, a loose tab bracket attached to the boom head in a state of protruding forward from the boom head of the boom, a loose pulley attached to the loose tab bracket so as to be rotatable about a rotation axis, and around which the wire rope is wound in a state where the hook is suspended from the front end of the boom, a hook in bracket attached to the loose tab bracket at a position on the side where the boom is lowered with respect to the rotation axis of the loose pulley, and capable of storing the hook, and being the hook in bracket in which the first pipe is formed, A construction machine comprising the above.

3. The overwinding detection device according to Claim 1, the boom that can be raised and lowered, the jib rotatably attached to the front end of the boom, comprising: The boom is provided with a sheave rotatably provided at the front end of the boom about a rotation axis. In a state where the hook is suspended from the front end of the boom, the wire rope is hung on the sheave. The second pipe is formed at the front end of the boom at a position on the side where the boom lies down with respect to the rotation axis of the sheave and on the front side of the boom. Construction machine.

Images