JP2008074607A - Over-winding detector of crane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an over-winding detector of a crane enabling easy attachment/detachment and replacement operations of a weight that detects over-winding on a boom or a jib, and having an attaching/detaching part with excellent durability. <P>SOLUTION: The attaching/detaching device 20 of the over-winding detector of a crane comprises a first bracket 31 connected to the over-winding detector 21 and a second bracket 32 connected to a sling 22. The first bracket 31 has a hook 42 with a free end 42b. The second bracket 32 has a connection hole 56 for inserting and locking the free end 42b therein. A slip-off prevention pin 43 for preventing the hook 42 from slipping off the connection hole 56 is attached to the second bracket 32. The first bracket 31 has a key hole 57 capable of guiding the hook 42 to the position where the hook 43 can be extracted from the connection hole 56 by inserting the slip-off prevention pin 43 therein and having a diameter in which the hook 42 cannot be inserted. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an overwinding detection apparatus for a crane having an improved structure for detaching / overloading an overwinding detection weight.

  A crane device such as a wheel crane or a truck crane hangs a wire rope from the boom or jib point sheave and winds the wire rope with the drum of the rope hoisting device. Work to move the load in the horizontal direction while lifting and lowering the load.

  Generally, in a crane device, a wire rope that holds a load hook is wound too much, and the load hook hits the boom or jib and damages the boom or jib or damages the wire rope. To prevent this, the overwinding is detected before the wire rope is overwound and an overwinding detector is detected, and an overwinding alarm is issued and the wire rope overwinding operation is prevented. A safety device called an overwinding prevention device is provided.

The conventional overwinding detection device includes an overwinding detector attached to the tip of the boom or jib and an overwinding detection weight suspended from the overwinding detector via a suspension cable such as a chain. When the wire rope is overwound, the load hanging hook hits the overwinding detection weight from below and the overwinding detection weight applied to the overwinding detector is reduced to reduce overload detection. The switch of the device is switched to the ON state to suppress the overwinding alarm to the worker and the hoisting operation of the rope hoisting device.
JP 9-194192 A

  By the way, the overwinding detection weight in the overwinding detection device is often of a combined type that can be used for either a boom or a jib. Therefore, the overwinding detection weight is provided with a detachable tool so that the entire suspension cable can be attached and detached. The conventional attachment / detachment tool is a method in which a metal fitting provided at the upper end of the suspension cable of the line overwinding detection weight is attached to the end block of the boom or jib by a shackle and a pin, and snap pins or split pins are used to fix the pins. Therefore, the work of attaching and detaching the pins is troublesome and the workability is poor. In addition, since there is a concern about the loss of shackles and pins, the procedure for preventing this is a complicated and troublesome attachment / detachment method. In addition, although a method using a carabiner as a detachable tool is also considered, since there are movable parts such as fine pivots when using a carabiner, the structure is prone to failure due to strength problems or rusting. There may be a problem of durability such as weather resistance.

  The present invention has been made paying attention to the above-mentioned problems, and the object of the present invention is to make it possible to easily attach and detach the overwinding detection weight to the boom or jib and to have excellent durability for crane overwinding. Is to provide.

The present invention includes a hook body attached to a lower end portion of a wire rope for hanging suspended from a tip portion of a boom or jib, and an overwinding detector attached to the tip portion of the boom or jib. The overwinding detector is suspended by a suspension line linked to the overwinding detector and is pushed up by the hook body when the wire rope for overloading is overwound to change the weight applied to the overwinding detector. In an overwinding detection device for a crane, comprising an overwinding detection weight adapted to detect an overwinding state and an attachment / detachment tool detachably connecting the suspension cable to the overwinding detector,
The attachment / detachment tool includes a first bracket connected to one of the overwinding detector and the suspension rope, a second bracket connected to the other of the overwinding detector and the suspension rope, and the above A hook provided on the first bracket and having a connecting portion for hanging the second bracket; a free end portion extending continuously from the connecting portion in a substantially vertical direction and having an open end; and the second bracket A connecting hole for inserting the free end portion and guiding the second bracket to the connecting portion; and provided in one of the first bracket and the second bracket; and the leading end of the free end portion in the connecting hole. A stopper member for preventing the brackets from being positioned at a position where the bracket can be inserted, and either the first bracket or the second bracket, and the stopper member is inserted. An overwinding detection device for a crane, comprising: a key hole having a diameter or a shape which is disposed at a position where the connecting hole can be guided to a free end portion of the hook and the free end portion cannot be inserted. It is.

  According to the present invention, it is possible to provide a crane overwinding detection device that is easy to attach and detach the overwinding detection weight to the boom or jib and has excellent durability.

  Hereinafter, the best mode of the present invention will be described with reference to the drawings. FIG. 1 shows the vicinity of the tip of a telescopic boom 1 in a mobile crane such as a wheel crane or a crawler crane. The telescopic boom 1 is composed of a plurality of booms that are telescopically connected, and the base end boom is connected to a swivel mounted on a vehicle carrier (not shown). A jib 2 (see FIG. 2) used to supplement the length of the telescopic boom 1 is stored on the side surface or the lower surface of the telescopic boom 1. The jib 2 can be attached so as to extend to the boom head 3 of the distal end boom 1a of the telescopic boom 1.

  An upper sheave and a lower sheave (not shown) are incorporated in the boom head 3 of the telescopic boom 1. As shown in FIG. 1, after the wire rope 4 fed from the winch of the main winding rope hoisting device provided on the swivel is hung on the upper sheave and the lower sheave, the lower sheave and the main hook 5 are further hooked. The main hook 5 is suspended by being wound around the sheave 7 provided in the block 6 a plurality of times and fixing the tip of the wire rope 4 to the hook block 6.

  In addition to the main winding lifting mechanism, a supplementary winding lifting mechanism using a single wire is provided at the distal end of the telescopic boom 1. An auxiliary sheave bracket 12 having an auxiliary sheave 11 is attached to the boom head 3 via a pivot pin 13 so as to be rotatable in the horizontal direction. As shown in FIG. 1, the auxiliary sheave bracket 12 can be installed at both a use state protruding forward and a retracted state (not shown) arranged close to the side surface of the boom head 3. The auxiliary sheave 11 is hung by a single wire 14 (separate from the wire rope 4) hung on the sheave 8 of the boom head 3 and is drawn downward. An auxiliary hook body 15 is attached to the suspended tip of the single wire 14. The auxiliary hook body 15 can be moved up and down at a distance corresponding to the unwinding of the single rope wire 14 by the winding device for auxiliary winding provided on the swivel base or drawing the single rope wire 14.

  The auxiliary hook body 15 includes an auxiliary hook 15a that holds and holds the auxiliary hook 15a, and a substantially cylindrical hook support 15b that supports the auxiliary hook 15a. The upper end of the hook support 15b is formed horizontally, and forms an abutting end 15c that hits an overwinding detection weight 24 described later. The tip of the single cord wire 14 is detachable from a connecting / attaching portion 15d provided in the upper end cylindrical portion of the hook support 15b. Further, the auxiliary winding lifting mechanism using the single cord wire is similarly installed in the head 16 of the jib 2 as shown in FIG. 2 (b).

  The auxiliary winding lifting mechanism is provided with an overwinding detection device 20 for the auxiliary winding single rope wire 14. The overwinding detection device 20 of the telescopic boom 1 and the overwinding detection device 20 of the head 16 of the jib 2 are the same, and the overwinding detection weight and suspension rope are those of the telescopic boom 1 and the head 16 of the jib 2. It is designed to be used as a replacement.

  As shown in FIG. 1, the overwinding detection device 20 of the telescopic boom 1 is provided on the auxiliary sheave bracket 12. That is, the overwinding detection device 20 includes an overwinding detector 21 attached to the auxiliary sheave bracket 12, a first suspension rope 22 suspended from the overwinding detector 21, and the auxiliary sheave bracket 12. A second suspension line 23 that is suspended and an overwinding detection weight 24 that is suspended by the plurality of suspension lines 22 and 23 are provided. The overwinding detection weight 24 is formed of a hollow disk shape or an annular member, and a hollow hole 24a through which the single cord wire 14 is passed is formed at the center thereof. The single wire 14 passes through the hollow hole 24a of the overwinding detection weight 24 in a loose state and hangs down. The overwinding detection weight 24 is suspended in a substantially horizontal state by the first suspension cable 22 and the second suspension cable 23.

  The overwinding detector 21 includes a detection switch. This detection switch is in an OFF state when receiving the weight of the overwinding detection weight 24 via the first suspension line 22, and at this time, the single wire 14 is wound by the winch of the auxiliary winding device. Allow movement. Further, when the weight of the overwinding detection weight 24 applied to the overwinding detector 21 is reduced, the detection switch is turned on, and the winding operation of the single wire 14 by the winch of the auxiliary winding device is restricted. To do. Also warn workers of overwinding conditions.

  Further, the plurality of suspension ropes 22 and 23 can be attached to and detached from the corresponding overwinding detector 21 and the auxiliary sheave bracket 12 by using an attachment / detachment tool 30 described later.

  The attachment / detachment tool 30 has a combined structure of two units of a first bracket 31 shown in FIG. 4 and a second bracket 32 shown in FIG. 5. The first bracket 31 and the second bracket 32 are: As shown in FIG. 3B, they are connected to each other. Further, the connection between the two can be released only by a specific artificial operation described later.

  Next, the first bracket 31 and the second bracket 32 of the attachment / detachment tool 30 will be specifically described. First, as shown in FIG. 4, the first bracket 31 includes a plate-like portion 41 and a hook (鉤) that protrudes downward from the surface of one plate surface (lower surface) of the plate-like portion 41. Part) 42, a pin (guide) 43 as a locking member protruding downward from one end surface of the plate-like part 41, and a first part formed by bending one end of the plate-like part 41 to the other (upward). Each of these parts includes an attachment piece (attachment portion) 46 and a second attachment piece 47 that stands on the upper surface of the plate-like portion 41 and is arranged to face the first attachment piece (attachment portion) 46. Are arranged at respective positions determined in a fixed relationship.

  The hook 42 is formed in a substantially U or J shape by bending a round bar-like member into a semicircular arc. The base end portion of the hook 42 is a base end portion 42 a that is fixed to the lower surface of the plate-like portion 41 by welding. The other end of the hook 42 extends upward and forms a free end 42b that is arranged in parallel with the base end 42a. The base end part 42a and the free end part 42b are connected via a U-shaped bottom part 42c. The bottom portion 42c serves as a connecting portion that engages with the other second bracket 32. The free end portion 42b extends upward from a bottom portion 42c as a connecting portion for connecting another bracket in the vertical direction, and the free end portion 42b has a length shorter than that of the base end portion 42a from the bottom portion 42c, and the free end portion 42b. 4 is separated from the lower surface of the plate-like portion 41 by a first distance L1, as shown in FIG. That is, the end (upper end) of the free end portion 42 b forms an opening 45 (described later) for inserting and removing the second bracket 32 (described later) between the lower end of the plate-shaped portion 41. It is also possible to remove the middle part of the round bar-like member forming the hook 42 to form the opening 45 and to form the free end 42b positioned below the opening 45.

  Further, the pin 43 for preventing detachment is formed of a round bar-like member, and the upper end portion is disposed in contact with the side end of the first mounting piece 46 and is fixed by welding to the first mounting piece 46. . The lower end portion of the locking pin 43 is disposed substantially parallel to the free end portion 42 b of the hook 42, and the lower end portion of the locking pin 43 is positioned to face the entrance / exit of the opening 45. Further, the diameter (maximum diameter) of the rod-shaped member of the hook 42 is larger than the diameter (maximum diameter) of the pin 43 for detachment prevention. As shown in FIG. 4 (b), the lower end portion of the locking pin 43 and the upper end portion of the free end portion 42b of the hook 42 face each other with a gap G and are arranged so as to overlap each other in the vertical direction. ing. That is, as shown in FIG. 4C, in the horizontal direction, a predetermined gap G is formed between the locking pin 43 and the free end 42b of the hook 42, and the locking pin 43 and The free ends 42b of the hooks 42 are in a relationship that does not contact each other. Further, as shown in FIG. 4 (d), the center of the locking pin 43 and the center of the free end 42b of the hook 42 are separated by a second distance L2.

  The free end portion 42b of the hook 42 and the anti-disengagement pin 43 opposite to the hook portion 42 are both formed as straight portions, but both portions are bent at a parallel interval. It is also possible. Moreover, the case where the space | interval of the free end part 42b of the hook 42 and the pin 43 for anti-separation which opposes this may spread below. In this case, the second distance L2 indicates the distance between the upper end (termination) of the free end portion 42b and the portion of the anti-slip pin 43 corresponding thereto. Further, the distance between the upper end (termination) of the free end portion 42b and the corresponding portion of the locking pin 43 is minimized.

  Further, the first mounting piece 46 and the second mounting piece 47 are respectively formed with mounting holes 48, and these mounting holes 48 are located on the same straight line. Then, the connecting pin 49 is inserted over the mounting holes 48 of the mounting pieces 46 and 47, and the connecting pin 49 is inserted into the connecting metal fitting 51 provided at the lower portion of the overwinding detector 21 to be stopped. 31 is connected to the overwinding detector 21 (see FIG. 3A). The first bracket 31 may be integrally connected to the overwinding detector 21 as a part of the overwinding detector 21.

  On the other hand, as shown in FIG. 5, the second bracket 32 has a main body portion formed by a plate-like member, and a connection portion formed with a diameter through which the member of the hook 42 can be inserted in an intermediate portion of the plate-like portion 55. A hole 56 is formed. A key hole 57 is formed in the one end side portion of the plate-like portion 55. The key hole 57 is formed with a diameter that allows the member of the locking pin 43 to be inserted. The key hole 57 is formed in a shape or a diameter in which the member of the hook 42 cannot be inserted, and can be selectively inserted through the locking pin 43. The thickness of the plate-like portion 55 is smaller than the first distance L1, and the second bracket 32 can be taken in and out from the opening 45.

  In the present embodiment, each of the members of the hook 42 and the detachment prevention pin 43 has a circular cross-sectional shape. The connection hole 56 is formed larger than the outer diameter of the member of the hook 42 so that the hook 42 can be inserted with play so as to be loosely fitted. Further, it is desirable that the diameter of the key hole 57 is smaller than the outer diameter of the member of the hook 42 so that the member of the locking pin 43 can be inserted without a relatively gap. The difference in diameter between the inner diameter of the key hole 57 and the outer diameter of the locking pin 43 is smaller than the difference in diameter between the inner diameter of the connection hole 56 and the outer diameter of the hook 42. Further, as shown in FIG. 5A, the distance between the central portions of the connecting hole 56 and the key hole 57 is set to the second distance L2. Accordingly, the first bracket 31 and the second bracket 32 are in a specific positional relationship, and the second bracket 32 and the second bracket 32 are simultaneously in a posture in which the free end portion 42b of the hook 42 in the first bracket 31 is inserted into the connection hole 56 of the second bracket 32. The detachment prevention pin 43 in the first bracket 31 can be inserted into the key hole 57 of the bracket 32.

  Further, as shown in FIG. 5A, one end portion of the plate-like portion 55 where the key hole 57 is located is formed in a tapered round shape centering on the key hole 57, and the outside of the round shape portion. The diameter is formed within the range of the diameter of the locking pin 43 of the first bracket 31 plus the gap G from the center of the key hole 57, and the free end portion 42b of the hook 42 and the locking pin 43 can pass through. Further, the width of the second bracket 32 is such that when the member of the hook 42 is inserted into the connecting hole 56, the second bracket 32 is suspended without hitting the other portions of the first bracket 31, and the second bracket 32 is inclined. Even if the hook 42 is lifted along the free end portion 42b, the hook 42 is formed with a size (2B) that hits the detachment prevention pin 43 (see FIG. 5A).

  The upper ends of the suspension ropes 22 and 23 are connected to the other end (lower end) of the second bracket 32. When a chain is used for the suspension ropes 22 and 23, the final tip link 58 of the chain may be welded to the other end of the plate-like portion 55 and fixed directly as shown in FIG. Of course, the suspension ropes 22 and 23 may be connected by providing a hole or the like for fitting the final tip link or the like.

  Next, a procedure for removing the second bracket 32 from the first bracket 31 in the attachment / detachment tool 30 will be described with reference to FIG. Each of the partial drawings (a) to (e) in FIG. 6 shows the removal order. FIG. 6A shows a state in which the hook 42 of the first bracket 31 is inserted into the connection hole 56 of the second bracket 32 and both are connected. As a first operation when removing the second bracket 32 from the hook 42 of the first bracket 31 in such a connected state, the plate-like portion 55 of the second bracket 32 is hooked as shown in FIG. 42, and the plate-like portion 55 is rotated around the free end portion 42b of the hook 42 so that the key hole 57 is prevented from coming off. Opposite below.

  Next, as shown in FIG. 6C, the second bracket 32 is lifted straight up so that the lower end portion of the locking pin 43 is inserted into the key hole 57 and the connection hole 56 of the second bracket 32 is inserted. The second bracket 32 is lifted vertically by using the free end 42b as a guide until the free end 42b of the hook 42 comes off. Then, the second bracket 32 is in a state where only the pin 43 for preventing the lock is engaged with the key hole 57.

  Therefore, as shown in FIG. 6 (d), the second bracket 32 is rotated horizontally around the pin 43 for detachment, and the second bracket 32 is moved to a side position that does not engage with the hook 42 member. Rotate.

  As shown in the partial view (d) of FIG. 6, the second bracket 32 is lowered from the state in which the second bracket 32 is directed outward, as shown in the partial view (e), and is removed from the pin 43 for retaining. . Thereby, the second bracket 32 can be completely removed from the first bracket 31.

  Further, the second bracket 32 can be attached to the first bracket 31 by a procedure reverse to this procedure.

  As can be seen from the above description, the first bracket 31 and the second bracket 32 cannot normally be provided, and the plurality of postures cannot be actually removed unless they pass through a specific order. In particular, the weight of the overwinding detection weight 24 is added to the second bracket 32 by the flexible suspension ropes 22 and 23, and when it is removed, it cannot normally occur from the posture in which it first becomes a specific rotation position horizontally. Since it is impossible in reality to move in a specific direction, it cannot be removed unless it is manually manipulated. Furthermore, compared to the difference between the diameter of the hook 42 of the first bracket 31 and the diameter of the connecting hole 56 of the second bracket 32, there is a difference between the pin 43 for preventing the first bracket 31 and the diameter of the key hole 57 of the second bracket 32. Since the difference is small, it is unlikely that the locking pin 43 of the first bracket 31 is fitted to the key hole 57 of the second bracket 32 and the locking pin 43 is inserted into the key hole 57. Therefore, the second bracket 32 cannot be detached from the first bracket 31 and cannot be removed unless the operation is manually performed.

  Since the connecting means of the second bracket 32 with respect to the first bracket 31 does not use parts that are troublesome to attach and detach such as snap pins or split pins, the overwinding detection device 20 is connected to the auxiliary winding lifting mechanism of the telescopic boom 1. The attachment / detachment work when replacing the jib 2 with the auxiliary winding lifting mechanism of the head 16 is simple and easy, and the workability is very good. Further, since there is no connecting part that is separated like a shackle or pins, and the cause of the loss of the part is eliminated, the troublesome management of the small parts is also eliminated. In addition, since there is no movable part such as a fine pivot such as a carabiner and the structure is simple and strong, durability such as weather resistance of the attachment / detachment tool 30 can be secured. In particular, it is an excellent structure optimal for cranes used outdoors.

  FIG. 8 shows a detachable tool obtained by modifying the detachable tool 30. The attachment / detachment tool 60 is provided with a locking pin 43 provided in the first bracket 31 toward the second bracket 32 and a key hole 57 for fitting the locking pin 43 toward the first bracket 31. It is what I did. The locking pin 43 is fixed to the plate-like portion 55 in the direction of the center of the connection hole 56 of the second bracket 32 and in the direction perpendicular to the plate surface of the plate-like portion 55. The center of the free end portion 42b of the hook 42 and the center of the key hole 57 are separated by the second distance L2. Similarly, the distance between the center of the connection hole 56 of the second bracket 32 and the center of the pin 43 for retaining is also separated by the second distance L2. The second bracket 32 is provided with a hole 61 to be engaged through the tip of the suspension cable.

  Next, a procedure for removing the second bracket 32 from the first bracket 31 in the detachable tool 60 will be described with reference to FIG. Each of the partial drawings (a) to (e) in FIG. 8 shows the order of removal. FIG. 8A shows a state in which the hook 42 of the first bracket 31 is inserted and connected to the connection hole 56 of the second bracket 32. The first operation when removing the second bracket 32 from the first bracket 31 in the connected state is as shown in a partial view (b) of FIG. The posture is vertical and horizontal with respect to the end 42b.

  Then, the plate-like portion 55 of the second bracket 32 is rotated around the free end portion 42b of the hook 42 while keeping the posture in a vertical and horizontal orientation with respect to the free end portion 42b of the hook 42, and a pin for preventing the hook 42 from coming off. It stops at the position where the key hole 57 of the first bracket 31 is located above 43.

  Next, as shown in FIG. 8C (c), the second bracket 32 is lifted straight up to insert the pin 43 for preventing the second bracket 32 from coming off into the key hole 57 of the first bracket 31, and 2. Lift up to the position where the free end 42b of the hook 42 comes out of the connecting hole 56 of the bracket 32. Then, the second bracket 32 is in a state in which only the pin 43 for preventing the locking is engaged with the key hole 57.

  Therefore, as shown in the partial diagram (d), the second bracket 32 is rotated around the pin 43 for preventing the locking until the position of the connecting hole 56 is located on the side where the hook 42 is not hooked. Evacuate.

  Finally, the second bracket 32 is lowered with respect to the first bracket 31 to prevent the second bracket 32 from coming off from the key hole 57 of the first bracket 31 as shown in the partial view (d). Pull out. As a result, the second bracket 32 can be completely removed from the first bracket 31. When the second bracket 32 is attached to the first bracket 31, the procedure is reversed.

  As described above, both of the first bracket 31 and the second bracket 32 are not normally possible. Since a plurality of postures must be passed through a specific order, they cannot be removed. As in the case of the attachment / detachment tool 30 described above, various functions and effects can be achieved.

  FIG. 9 shows an attachment / detachment tool 70 according to still another embodiment of the present invention. The attaching / detaching tool 70 is a modification of the first bracket 31 in the attaching / detaching tool 30 described above, and is formed by bending the hook 42 and the anti-disengagement pin 43 by bending a round bar-like member. A portion corresponding to 41 is also formed by bending a rod-like member in a spiral shape, and this spiral portion is used as an attachment portion 71 of the first bracket 31. Other forms and operations are the same as those of the attachment / detachment tool 30 described above. Therefore, there are various effects as in the case of the attachment / detachment tool 30 described above. Further, since the first bracket 31 can be manufactured by bending a rod-shaped member, the manufacturing of the first bracket 31 is simple without connecting the constituent parts of the first bracket 31 by welding or the like.

  FIG. 10 shows an attachment / detachment tool 80 according to still another embodiment of the present invention. This detachable tool 80 is a modification of the first bracket 31 described above, similar to the detachable tool 70 described above, and its hook 42 and detachment prevention pin 43 are manufactured by bending a round bar-shaped member. The attachment portion is not a spiral, but is only a semicircular arc, and the semicircular arc portion is connected with another connection fitting 82 to constitute the attachment portion 82 of the first bracket 31. Other forms and operations are the same as those of the attachment / detachment tool 30 described above. Therefore, there are various effects as in the case of the attachment / detachment tool 30 described above. Further, since the first bracket 31 can be manufactured by bending a rod-like member, the first bracket 31 can be manufactured easily.

  11 and 12 show a detachable tool 90 according to still another embodiment of the present invention, which is a modification of the configuration of the first bracket 31 of the detachable tool 30. FIG. The first bracket 31 according to the present embodiment is provided with a detachment prevention pin 43 attached to the plate-like portion 41 so as to be movable in the vertical direction. The upper end portion of the member that forms the pin 43 for preventing the detachment penetrates the plate-like portion 41 and protrudes upward, and a knob 91 composed of a spherical enormous portion is formed at the tip of the protrusion. As shown in FIG. 11, a hook-shaped stopper 92 is formed in the middle of the upper end portion of the stopper pin 43 that protrudes. An elastic body as an elastic urging means, for example, a compression coil spring 93 is fitted around the outer periphery of the upper end of the through hole of the pin 43 for coming off. One end of the compression coil spring 93 is applied to the hook-shaped stopper 92 and the other end is applied to the upper end edge of the compression coil spring housing sheath 94 to elastically bias the detachment prevention pin 43 downward. Therefore, the pin 43 for detachment is urged to a position where the hook-shaped stopper 92 hits the upper surface of the plate-like portion 41 by the compression coil spring 93, and is normally kept at that position. In this standby position, the lower part of the locking pin 43 extends longer than the case of the attachment / detachment tool 30 and is, for example, long enough to line up with the substantially entire length of the free end 42b of the hook 42. (See FIG. 11). The compression coil spring housing sheath 94 is fixed to the plate-like portion 41. Further, the knob 91 is exposed to the outside from the upper end of the compression coil spring housing sheath 94 so that an operator can pick the knob 91 with his / her hand and pull the stopper pin 43 upward. It has become.

  As shown in FIG. 12, when the locking pin 43 is pulled upward, the lower end position of the locking pin 43 is the height of the detachable tool 30 described above. Therefore, it will be in the state which can be removed similarly to the attachment / detachment tool 30 mentioned above. However, normally, the lower portion of the locking pin 43 extends farther downward than that, so that the second bracket 32 is completely prevented from being in the state shown in FIG. Unless 43 is artificially raised, it is impossible to remove it. From this blocking action, it is desirable that the lower end of the locking pin 43 reaches the vicinity of the bottom 42c of the hook 42. Therefore, the lower end of the locking pin 43 may be further extended downward.

  FIG. 13 relates to still another embodiment of the present invention. In each of the above-described embodiments, the detachable tools 30 and 60 are attached to both the first suspension line 22 suspended from the overwinding detector 21 and the second suspension line 23 suspended from the auxiliary sheave bracket 12 respectively. , 70, 80, 90 are used. On the other hand, for example, as shown in FIG. 13, only the first suspension rope 22 is used, and the second suspension rope 23 does not use an attachment / detachment tool. In addition, the auxiliary sheave bracket 12 is directly and detachably connected to the connection fitting 101.

  Further, as shown in FIG. 13, the connection fitting 101 has a connection sheath 103 that fits on a support shaft 102 provided on the auxiliary sheave bracket 12, and the upper end of the second suspension rope 23 is attached to the connection sheath 103. Connecting. At the end of the support shaft 102 to which the connecting sheath 103 is attached, a locking hole 105 into which the quick pin 104 for retaining is inserted is formed. The retaining quick pin 104 has an elastic piece 106 fitted on the outer periphery of the end of the support shaft 102, and the elastic piece 106 is placed on the outer periphery of the end of the support shaft 102 with the quick pin 104 inserted into the locking hole 105. The quick pin 104 is prevented from coming off by being elastically engaged.

  In each of the above embodiments, the overwinding prevention device for the single winding work auxiliary winding wire is an example, but the overwinding prevention device of the present invention is applied to the overwinding prevention device for the main winding wire. Is also possible. In the above embodiments, the first bracket and the second bracket that are positioned on the lower side by reversing the vertical positional relationship between the first bracket and the second bracket are referred to as second brackets and are located on the upper side. The two brackets may be referred to as a first bracket. The attachment / detachment tool can be configured by variously combining the attachment / detachment tool types of the above embodiments.

The perspective view of the telescopic boom front-end | tip part vicinity of the crane apparatus which applied the overwinding prevention apparatus which concerns on one Embodiment of this invention to the auxiliary winding lifting mechanism. (A) is the front view which looked at the bracket for auxiliary sheaves provided in the boom head from the front, (b) is the front view which looked at the tip head vicinity of the jib from the front. (A) is a perspective view near the bracket for auxiliary sheaves showing a state in which the overwinding prevention device is mounted, and (b) is a perspective view in a state in which brackets of attachment / detachment tools in the overwinding prevention device are assembled. (A) is a perspective view of the first bracket of the detachable tool, (b) is a front view of the first bracket, (c) is a side view of the first bracket, and (d) is a bottom view of the first bracket. . (A) is a front view of the 2nd bracket of the said attachment / detachment tool, (b) is a longitudinal cross-sectional view of the said 2nd bracket. (A)-(e) is explanatory drawing which shows the procedure in the case of removing both brackets of the said attachment / detachment tool. Explanatory drawing of the relationship in the state which combined both brackets in the said attachment / detachment tool. It is a modification of the above detachable tool, (a) is a perspective view of the detachable tool in a state where both brackets of the detachable tool are assembled, and (b) to (e) are procedures for removing both brackets of the detachable tool. FIG. (A) is a front view in a state in which both brackets of the detachable tool are assembled, (b) is a perspective view in a state in which both brackets of the detachable tool are assembled. c) The bottom view of the 1st bracket of the attachment / detachment tool. Still another modified example of the detachable tool, wherein (a) is a front view of a state in which both brackets of the detachable tool are assembled, and (b) is a perspective view of a state in which both brackets of the detachable tool are also assembled. (C) is the perspective view seen from the other direction in the state which assembled | attached both brackets of the attachment / detachment tool similarly, (d) is the bottom view of the 1st bracket of attachment / detachment tool. It is sectional drawing of the 1st bracket in the further another modification of the said attachment / detachment tool. (A) is a perspective view in the state which assembled | attached both brackets in the attachment / detachment tool of the further another modification of the attachment / detachment tool shown in the said FIG. 11, (b) is a perspective view in the state at the time of removing brackets. An explanatory view of an example using an attaching / detaching tool only for a part of the suspension rope when the overwound detection weight is suspended using a plurality of suspension ropes according to still another embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 20 ... Overwinding prevention apparatus, 21 ... Overwinding detector, 22 ... 1st suspension rope, 23 ... 2nd suspension rope, 24 ... Weight for overwinding detection, 30 ... Detachment tool, 31 ... 1st bracket, 32 ... 2nd bracket, 42 ... Hook part, 43 ... Pin for retaining

Claims (3)

A hook attached to the lower end of a wire rope for hanging hanging from the tip of the boom or jib so that it can be raised and lowered;
An overwinding detector attached to the tip of the boom or jib;
The overwinding detector is suspended by a suspension line linked to the overwinding detector and is pushed up by the hook body when the wire rope for overloading is overwound to change the weight applied to the overwinding detector. An overwinding detection weight that detects an overwinding state by,
A detachable tool for detachably connecting the suspension cable to the overwinding detector,
In an overwinding detection device for a crane equipped with
A first bracket connected to one of the overwinding detector and the suspension rope;
A second bracket connected to the other of the overwinding detector and the suspension cable;
A hook provided on the first bracket and having a connecting portion for hanging the second bracket, and a free end portion extending continuously from the connecting portion in a substantially vertical direction and having an open end;
A connecting hole provided in the second bracket, for inserting the free end portion and guiding the second bracket to the connecting portion;
A locking member that is provided on either the first bracket or the second bracket and prevents the brackets from being positioned at a position where the tip of the free end can be inserted into the connection hole;
A diameter or a diameter provided on either the first bracket or the second bracket, inserted in the member for preventing detachment and disposed at a position where the connecting hole can be guided to the free end of the hook, and the free end cannot be inserted. A keyhole having a shape;
An overwinding detection device for a crane, comprising:   The diameter difference between the inner diameter of the key hole and the outer diameter of the locking member is smaller than the diameter difference between the inner diameter of the connection hole and the outer diameter of the hook portion. Crane overwinding detection device.   2. The key hole according to claim 1, wherein the locking member is inserted into the free end of the hook from a substantially vertical direction and the connecting hole is led to the free end of the hook. The crane overwinding detection device according to claim 2.

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