Jib system retention device

Abstract

To provide a jib mooring device capable of performing a jib locking and a jib unlocking by a human power, capable of reducing boom weight so as to improve assemblability.SOLUTION: A jib mooring device comprises: a locking device 2 installed on a tower 34; and a locking objective member 3 installed on a jib 35 and locked by the locking device when the jib is folded with respect to the tower. The locking device comprises: a latch 11 capable of moving between a locking position for locking the locking objective member and a releasing position for releasing the lock of the locking objective member; a lock releasing member 12; an impelling member 13 to impel the lock releasing member toward the locking position; a winch installed on a tower base or a crane body; and a rope 14. When the winch is actuated in one direction, the rope is wound around the winch so as to move the lock releasing member moves to the lock releasing position. When the winch is actuated in the other direction which is opposite to the one direction, the rope is delivered from the winch so as to allow the lock releasing member to move to the locking position.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a jib mooring device for a crane in which a jib is attached to the tip of a tower in a manner that allows it to be raised and lowered. [Background technology]

[0002] Patent Documents 1 and 2 disclose a jib mooring device for locking a folded jib of a crane to a tower. In Patent Document 1, a cylinder device is provided to rotate a lever plate that is integral with a latch, and the state in which the latch has engaged the engaging shaft on the jib side is released by remotely operating the cylinder device from inside the cab.

[0003] In addition, in Patent Document 2, a lock pin is connected to one end of an unlocking lever provided on the tower side, and a connector is connected to the other end. When the connector is pulled by an actuator, the unlocking lever rotates around a fulcrum, and the lock pin is released from the state where it has locked the locking shaft on the jib side. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-231088 [Patent Document 2] JP 2017-30965 A Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, a rope connected to the lever plate is also provided separately, so if the cylinder becomes inoperable in the locked state (the latch is engaged with the locking shaft), the worker can release the lock by pulling the rope. However, if the cylinder becomes inoperable in the unlocked state (the latch is disengaged from the locking shaft), there is a problem that the latch cannot be returned to the locking position and the jib cannot be locked.

[0006] In addition, in Patent Document 2, when the actuator becomes inoperable, the connecting body is removed from the actuator, and the worker pushes or pulls the connecting body to put the lock pin into a state where it engages the locking shaft on the jib side, or releases that state. However, the connecting body needs to have a rigidity that does not deform over a distance of several tens of meters from the boom foot to the lock release lever. Therefore, the mass of the connecting body is large, which affects the capacity of the crane. Also, the work of assembling the connecting body is complicated.

[0007] An object of the present invention is to provide a jib mooring device that allows the jib to be locked and unlocked manually, and that reduces the mass of the boom and improves assembly ease. [Means for solving the problem]

[0008] The present invention relates to a jib mooring device for a crane in which a jib is attached to the tip of a boom so as to be able to be raised and lowered, the device comprising a locking device provided on the boom, and a locked member provided on the jib and locked by the locking device when the jib is folded relative to the boom, the locking device comprising a locking member movable between a locking position for locking the locked member and a release position for releasing the lock of the locked member, and a locking member connected to the locking member and movable between a locking position for positioning the locking member at the locking position and a lock release position for positioning the locking member at the release position. the locking mechanism includes an unlocking member, a biasing member which biases the unlocking member toward the locked position, a winch provided at the base of the boom or the crane body, and a rope which is reeled out from the winch and connected to the unlocking member, and when the winch is operated in one direction, the rope is wound onto the winch and the unlocking member moves to the unlocked position, and when the winch is operated in the other direction which is opposite to the one direction, the rope is reeled out from the winch and the unlocking member can move to the locked position. Effect of the Invention

[0009] According to the present invention, when the winch is operated in one direction, the rope is wound on the winch and the unlocking member moves to the unlocking position. This releases the locked state between the locking member and the locked member. On the other hand, when the winch is operated in the other direction, the rope is unwound from the winch and the unlocking member can move to the locked position. Then, when the unlocking member moves to the locked position by the biasing force of the biasing member, the locked member is locked to the locking member. Here, if the winch breaks down and the rope cannot be wound up, the locked state between the locking member and the locked member can be released by pulling the rope manually. Also, if the winch breaks down and the rope cannot be unwound, the rope can be removed from the winch or cut, and the rope can be unwound manually, making it possible to move the unlocking member to the locked position, and thus the locked member can be locked to the locking member. This allows the jib to be locked and unlocked manually. In addition, the mass of the boom can be reduced because the rope is lighter than the connector of Patent Document 2. Moreover, the rope does not require assembly as in the case of the connector, which improves ease of assembly. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a side view of a tower crane in a first embodiment. [Diagram 2] 2 is an enlarged view of a main part A in FIG. 1 in the first embodiment, showing a state in which the latch is in a locking position and locks a locked member. FIG. [Diagram 3] 2 is an enlarged view of a main part A in FIG. 1 in the first embodiment, showing a state in which the latch is in a release position and the locked member is released from the lock. FIG. [Figure 4] 2 is an enlarged view of a main part A in FIG. 1 in the first embodiment, illustrating a state before a latch engages a member to be engaged. FIG. [Diagram 5] FIG. 2 is an enlarged view of a main part B in FIG. [Figure 6] FIG. 2 is a hydraulic circuit diagram of the jib mooring device in the first embodiment. [Figure 7]1 in the second embodiment, showing a state in which the lock pin is located at a locking position and locks the locked member. FIG. [Figure 8] 1 in the second embodiment, showing a state in which the lock pin is in the release position and the lock of the locked member is released. FIG. [Figure 9] 1 in a second embodiment, showing a state before the lock pin locks the locked member. FIG. [Figure 10] FIG. 11 is an enlarged plan view of the jib mooring device in the second embodiment. [Figure 11] FIG. 11 is a hydraulic circuit diagram of a jib mooring device in a second embodiment. [Figure 12] FIG. 11 is a side view of a tower crane in a third embodiment. [Figure 13] 12 is an enlarged view of a main part C in FIG. 11 in the third embodiment, showing a state in which the hook is at the locking position and locks the locked member. FIG. [Figure 14] 12 is an enlarged view of a main part C in FIG. 11 in the third embodiment, showing a state in which the hook is in the release position and the lock of the locked member is released. FIG. [Figure 15] 12 is an enlarged view of a main part C in FIG. 11 in the third embodiment, showing a state in which an engaging portion of an engaging member is located at a second position. FIG. [Figure 16] 12 is an enlarged view of a main part C in FIG. 11 in the third embodiment, showing a state in which an engaging portion of an engaging member is located at a third position. FIG. [Figure 17] FIG. 14 is an enlarged view of a main part D in FIG. [Figure 18] 15 is an enlarged view of a main part E in FIG. 14, showing a state in which an engaging portion of an engaging member is located at a first position. FIG. [Figure 19] 15 is an enlarged view of a main part E in FIG. 14, showing a state in which an engaging portion of an engaging member is located between a first position and a second position. FIG. [Figure 20] FIG. 11 is a hydraulic circuit diagram of a jib mooring device in a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0012] [First embodiment] (Tower crane configuration) The jib mooring device 1 of the first embodiment is provided on a tower crane 30, as shown in Fig. 1, which is a side view of the tower crane 30. The tower crane 30 has a configuration in which an upper rotating body 32 is rotatably mounted on a crawler-type lower traveling body 31. The tower crane 30 may be a mobile crane that uses moving means other than crawlers (for example, wheels), or may be a fixed crane that does not have moving means. In addition, the application of the present invention is not limited to tower cranes, and the present invention can also be applied to, for example, a luffing crane.

[0013] The upper rotating body 32 has a cab 33, a tower (boom) 34, a jib 35, a gantry 36, struts 37, a lower spreader 38, a hook winch (not shown), a jib hoisting winch (not shown), a boom hoisting winch (not shown), a counterweight 39, and a backstop device 40. Hereinafter, the side from the counterweight 39 toward the cab 33 will be referred to as the "front side," and the side from the cab 33 toward the counterweight 39 will be referred to as the "rear side."

[0014] The operator's cab 33 is provided at the front of the upper rotating body 32. The tower 34 is connected to the front of the upper rotating body 32 so as to be able to rise and fall relative to the upper rotating body 32. One end of a boom guy line 49 is connected to the tip of the tower 34. The tower 34 in this embodiment has a lattice structure.

[0015] The jib 35 is connected to the tip of the tower 34 so as to be able to rise and fall relative to the tower 34. A jib point sheave 41 is provided at the tip of the jib 35. A hook device (not shown) is suspended from this jib point sheave 41 via a hoisting rope (not shown). FIG. 1 illustrates both a working state in which the jib 35 extends diagonally upward and forward, and a locked state in which the jib 35 is folded and locked to the front portion of the tower 34. The jib 35 in this embodiment has a lattice structure.

[0016] The gantry 36 is attached to the rear of the upper rotating body 32. The strut 37 has a triangular shape in a plan view from the side, and is attached to the tip of the tower 34. The tip of a front strut 37b of the strut 37 and the tip of the jib 35 are connected by a jib guy line 44.

[0017] A jib hoist rope 48 is hung between a lower jib hoist spreader 45 attached to the lower back side of the tower 34 and an upper jib hoist spreader 47 connected to one end of a strut guy line 46. The other end of the strut guy line 46 is connected to the tip of the rear strut 37a of the strut 37.

[0018] The lower spreader 38 is attached to the upper end of the gantry 36. A boom hoisting rope 51 is hung between the lower spreader 38 and an upper spreader 50 connected to the other end of the boom guy line 49.

[0019] The hook winch, jib hoist winch, and boom hoist winch are each disposed in the center of the upper rotating body 32. The hook winch winds up or pays out the hoisting rope to raise or lower the hook device. The jib hoist winch winds up or pays out the jib hoist rope 48 to raise or lower the strut 37 about the connection point with the tip of the tower 34. As a result, the jib 35 rises and falls about the connection point with the tower 34. The boom hoist winch winds up or pays out the boom hoist rope 51 to raise or fall the tower 34 around the boom foot pin 52, which is its fulcrum.

[0020] The counterweight 39 is mounted on the rear of the upper rotating body 32. The backstop device 40 is provided on the lower back side of the tower 34. The backstop device 40 is received by a backstop receiver (not shown) provided on the upper rotating body 32, thereby restricting the rearward rotation of the tower 34.

[0021] (Configuration of jib mooring device) As shown in Figs. 2 to 4 which are enlarged views of a main part A in Fig. 1, the jib mooring device 1 has a locking device 2 and a locked member 3. The locking device 2 is provided on the tower 34. The locked member 3 is provided on the jib 35. The locked member 3 is provided at a position facing the locking device 2 when the jib 35 is folded relative to the tower 34. As shown in Fig. 2, the locked member 3 is locked by the locking device 2 when the jib 35 is folded relative to the tower 34. The locked member 3 is locked by the locking device 2 when the jib 35 is folded, so that the jib 35 can be moored to the tower 34.

[0022] The locked member 3 is tubular and fixed to the jib side bracket 25 by welding. The jib side bracket 25 is attached to the jib 35 by a U-bolt or the like.

[0023] The locking device 2 has a latch (locking member) 11, an unlocking member 12, a biasing member 13, and a rope 14. The latch 11 is rotatably connected to a support bracket 15 via a fulcrum pin 15a. The support bracket 15 is attached to a tower 34 with a U-bolt or the like. The latch 11 rotates about the fulcrum pin 15a, thereby being movable between a locking position (position shown in FIG. 2) where the locked member 3 is locked and a releasing position (position shown in FIG. 3) where the locked member 3 is released from the lock.

[0024] The support bracket 15 is provided with a locking side stopper 15b and a release side stopper 15c. As shown in Fig. 2, when the latch 11 is located at the locking position, the side surface of the latch 11 abuts against the locking side stopper 15b, thereby restricting the rotation of the latch 11. Also, as shown in Fig. 3, when the latch 11 is located at the release position, the side surface of the latch 11 abuts against the release side stopper 15c, thereby restricting the rotation of the latch 11.

[0025] A downwardly protruding claw 11a is formed on the latch 11. An engagement groove 11b with which the locked member 3 can engage is formed on the support bracket 15 side of the claw 11a of the latch 11. An inclined surface 11c that is inclined from above toward the support bracket 15 side from the top to the bottom is formed on the opposite side of the engagement groove 11b from the claw 11a of the latch 11.

[0026] The unlocking member 12 is rod-shaped and attached (connected) to the side of the latch 11. The front end of the unlocking member 12 is fixed to the latch 11, and a rope 14 is connected to its rear end. The rope 14 is reeled out from a winch, which will be described later. Note that instead of the rope 14, a string-like member such as a wire or chain may be used.

[0027] The unlocking member 12 is movable between a locked position (position shown in FIG. 2) where the latch 11 is located in the locked position, and an unlocked position (position shown in FIG. 3) where the latch 11 is located in the unlocked position.

[0028] The biasing member 13 is a spring, and is disposed between the unlocking member 12 and the support bracket 15. One end of the biasing member 13 is attached to the unlocking member 12, and the other end of the biasing member 13 is attached to the support bracket 15. The biasing member 13 biases the unlocking member 12 toward the locked position.

[0029] As shown in Fig. 5, which is an enlarged view of main part B in Fig. 1, the locking device 2 has a winch 16 and a hydraulic motor 17. The winch 16 is provided at the base of the tower 34. The rope 14 is wound around the winch 16 and is paid out from the winch 16. The hydraulic motor (motor) 17 rotates (operates) the winch 16 in one direction. The winch 16 may be provided on the crane body, such as at the front of the upper rotating body 32.

[0030] When the winch 16 is operated in one direction, the rope 14 is wound onto the winch 16. As a result, as shown in FIG. 3, the unlocking member 12 moves to the unlocking position against the biasing force of the biasing member 13. As a result, the latch 11 moves to the unlocking position, and the locked state with the locked member 3 is released. On the other hand, when the winch 16 is operated in the other direction opposite to the one direction, the rope 14 is unwound from the winch 16. As a result, the unlocking member 12 can move to the locked position, as shown in FIG. 2. Then, as a result of the unlocking member 12 moving to the locked position, the latch 11 moves to the locked position, and it becomes possible to lock the locked member 3.

[0031] Here, as shown in FIG. 3, the biasing member (pulling member) 13 biases the lock release member 12 toward the locked position, thereby pulling the rope 14 in the direction in which the rope 14 is reeled out from the winch 16. When power is supplied from the hydraulic motor 17, the winch 16 is operated in one direction by the hydraulic motor 17. As a result, the rope 14 is wound up onto the winch 16. On the other hand, when power is not supplied from the hydraulic motor 17, the winch 16 is operated in the other direction by the pulling force of the biasing member 13. As a result, the rope 14 is reeled out from the winch 16. At this time, the rope 14 is gradually reeled out due to the pipeline resistance of the hydraulic motor 17, etc.

[0032] In this way, when power is not supplied from the hydraulic motor 17 to the winch 16, the winch 16 can be operated in the other direction by the pulling force of the biasing member 13, making it possible to move the unlocking member 12 to the locked position. When power is not supplied from the hydraulic motor 17, for example in the event that the winch 16 breaks down, the winch 16 is operated in the other direction, so that the unlocking member 12 does not move toward the unlocked position. This makes it possible to prevent the locked state between the latch 11 and the locked member 3 from being unintentionally released.

[0033] 2 to 4, the jib mooring device 1 has a detection device 4. The detection device 4 detects whether or not the locked member 3 is locked by the latch 11. The detection device 4 has a limit switch 18, a rotating lever 19, and a spring 20.

[0034] The limit switch 18 is attached to the side of the latch 11. The limit switch 18 has a lever 18a. The limit switch 18 is turned ON when the lever 18a is pressed by the rear end of the rotating lever 19, and is turned OFF when the lever 18a is no longer pressed by the rear end of the rotating lever 19.

[0035] The rotating lever 19 is rotatably attached to the latch 11 via a fulcrum pin 19a. The rotating lever 19 is movable between a standby position (position shown in FIG. 4) where the rotating lever 19 overlaps with the engagement groove 11b of the latch 11 to close the engagement groove 11b, and an operating position (position shown in FIG. 2) where the rotating lever 19 moves away from the engagement groove 11b to open the engagement groove 11b.

[0036] The spring 20 is disposed between the latch 11 and the rotating lever 19. One end of the spring 20 is attached to the latch 11, and the other end of the spring 20 is attached to the rear end of the rotating lever 19. The spring 20 biases the rotating lever 19 toward the standby position. In the standby position shown in FIG. 4, the front end of the rotating lever 19 abuts against a stopper 11d provided on the latch 11. This restricts the rotation of the rotating lever 19, and prevents the front end of the rotating lever 19 from coming off the latch 11.

[0037] As shown in Fig. 2, when the latch 11 moves to the locking position, the rotating lever 19 moves to the operating position against the biasing force of the spring 20. As a result, the lever 18a of the limit switch 18 is pressed by the rear end of the rotating lever 19, and the limit switch 18 turns ON. On the other hand, as shown in Fig. 3, when the latch 11 moves to the release position, the rotating lever 19 moves to the standby position by the biasing force of the spring 20. As a result, the lever 18a of the limit switch 18 is no longer pressed by the rear end of the rotating lever 19, and the limit switch 18 turns OFF.

[0038] 6, which is a hydraulic circuit diagram of the jib mooring device 1, the jib mooring device 1 has a hydraulic pump 5, a directional control valve 6, a controller 7, and a pressure regulating valve 8. The hydraulic pump 5 is a power source for a hydraulic motor 17, and supplies hydraulic oil to the hydraulic motor 17. The hydraulic motor 17 rotates the winch 16 in one direction with the hydraulic oil supplied from the hydraulic pump 5.

[0039] The directional control valve (switching device) 6 switches the winch 16 between operation in one direction and non-operation. The directional control valve 6 can be switched between a first position 6a and a second position 6b. In the first position 6a, hydraulic oil from the hydraulic pump 5 is supplied to the hydraulic motor 17. In the second position 6b, hydraulic oil from the hydraulic pump 5 is not supplied to the hydraulic motor and is returned to the tank. In other words, when the directional control valve 6 is switched to the first position 6a, hydraulic oil is supplied to the hydraulic motor 17, and the winch 16 is operated in one direction. This allows the lock release member 12 to be moved to the unlock position. On the other hand, when the directional control valve 6 is switched to the second position 6b, hydraulic oil is not supplied to the hydraulic motor 17, and the winch 16 is not operated in one direction. This allows the lock release member 12 to be moved to the lock position by the biasing force of the biasing member 13.

[0040] The controller 7 controls the directional control valve 6. A signal from the limit switch 18 is input to the controller 7. The controller 7 judges whether or not the locked member 3 is locked to the latch 11 based on the signal from the limit switch 18. The controller 7 turns on the lock lamp 21 when the locked member 3 is locked to the latch 11. The lock lamp 21 lights up in red, for example. On the other hand, the controller 7 turns on the non-lock lamp 22 when the locked member 3 is not locked to the latch 11. The non-lock lamp 22 lights up in green, for example. The lock lamp 21 and the non-lock lamp 22 are each provided in the operator's cab 33 so that they can be seen by the operator operating the tower crane 30.

[0041] When the locked member 3 is locked to the latch 11 (see FIG. 2), the controller 7 switches the directional control valve 6 to the first position 6a to operate the winch 16 in one direction. This moves the unlocking member 12 to the unlocking position, and the locked state between the latch 11 and the locked member 3 can be released. On the other hand, when the locked member 3 is not locked to the latch 11 (see FIG. 4), the controller 7 switches the directional control valve 6 to the second position 6b to not operate the winch 16 in one direction. This allows the unlocking member 12 to be positioned in the lock position by the biasing force of the biasing member 13, and the latch 11 to be positioned in the locking position. As a result, the locked member 3 can be locked to the latch 11.

[0042] In this way, only when the locked member 3 is locked to the latch 11, the unlocking member 12 can be moved to the unlocking position to release the locked state between the latch 11 and the locked member 3. Furthermore, when the locked member 3 is not locked to the latch 11, the biasing force of the biasing member 13 can be used to move the unlocking member 12 to the locked position.

[0043] The pressure regulating valve 8 is provided between the hydraulic motor 17 and the directional control valve 6. The pressure regulating valve 8 adjusts the pressure of hydraulic oil supplied to the hydraulic motor 17. For example, by adjusting the pressure of the hydraulic oil so that the driving force of the winch 16 is as small as possible (for example, the minimum) at which the latch 11 can be moved to the release position, the weight of the locking device 2, in particular the lock release member 12, can be suitably reduced.

[0044] The jib mooring device 1 also has an unlocking switch (output device) 9. The unlocking switch 9 is provided in the driver's cab 33, and is operated by an operator (worker) who operates the tower crane 30. The unlocking switch 9 outputs a command to release the locked state between the latch 11 and the locked member 3 when operated by the operator.

[0045] The controller 7 receives a command from the unlocking switch 9 and controls the directional control valve 6 to operate the winch 16 in one direction, thereby releasing the locked state.

[0046] Here, when the locked member 3 is locked to the latch 11 and a command is received from the unlocking switch 9, the controller 7 controls the directional control valve 6 to operate the winch 16 in one direction. When the locked member 3 is locked to the latch 11 and a command is not received from the unlocking switch 9, the controller 7 does not control the directional control valve 6 to operate the winch 16 in one direction. Therefore, even if the locked member 3 is locked to the latch 11, the winch 16 is not operated in one direction unless a command is received from the unlocking switch 9. This makes it possible to prevent the locked state between the latch 11 and the locked member 3 from being unintentionally released.

[0047] In the above configuration, when the folded jib 35 is moored to the tower 34, the tower 34 is put in a vertically erected position as shown in FIG. 1. In this state, the jib 35 is hung down. When the jib 35 is hung down, the latch 11 is rotated toward the release position against the biasing force of the biasing member 13 by contacting the inclined surface 11c of the latch 11 as shown in FIG. 4. Then, when the latch 3 overcomes the claw 11a, the latch 3 is engaged with the engagement groove 11b as shown in FIG. 2, and the jib 35 is moored to the tower 34.

[0048] On the other hand, when the jib 35 moored to the tower 34 is to be released from the tower 34, the tower 34 is brought into a vertically erect position with the latch 11 engaged with the engaged member 3, as shown in Fig. 2. In this state, the winch 16 is rotated in one direction. Then, as shown in Fig. 3, the latch 11 moves to the release position, and the engaged state of the engaged member 3 is released. At this time, the jib 35 is hoisted so as to swing forward from the tower 34, and the jib 35 that was drawn to the tower 34 moves away from the tower 34.

[0049] In consideration of the need to change the mounting position when the length of the tower 34 and the jib 35 is changed, and of transportability, it is preferable to detachably mount the support bracket 15 to the main pipe of the tower 34 with a U-bolt or the like. Similarly, it is preferable to detachably mount the jib side bracket 25 to the main pipe of the jib 35 with a U-bolt or the like.

[0050] (Jib mooring operation) Next, the operation of the jib mooring device 1 will be described with reference to Figs.

[0051] (Mooring step) When mooring the folded jib 35 to the tower 34, first, as shown in Fig. 1, the boom hoisting rope 51 is wound up to bring the tower 34 into a vertically erect position. In this embodiment, the inclination angle of the tower 34 from the horizontal plane is 90 degrees, but is not limited to this.

[0052] Next, the jib hoist rope 48 is let out to hang the jib 35 vertically. At this time, the directional control valve 6 is switched to the second position 6b (see FIG. 6). Also, the latch 11 is in the locking position, the unlocking member 12 is in the locking position, and the rotating lever 19 is in the standby position (see FIG. 4). Inside the operator's cab 33, the locking lamp 21 is off and the non-locking lamp 22 is on.

[0053] When the locked member 3 comes close enough to the locking device 2, as shown in Fig. 4, the locked member 3 comes into contact with the inclined surface 11c of the latch 11 and slides along the inclined surface 11c. This causes the latch 11 to rotate toward the release position against the biasing force of the biasing member 13. Then, when the locked member 3 climbs over the claw 11a, the locked member 3 engages with the engagement groove 11b as shown in Fig. 2. This causes the jib 35 to be moored to the tower 34.

[0054] When the locked member 3 engages with the engagement groove 11b, the rotating lever 19 moves to the operating position and the limit switch 18 turns ON. As a result, the non-locking lamp 22 goes out and the locking lamp 21 lights up. This allows the operator to recognize that the locked member 3 is locked by the latch 11.

[0055] Next, the boom hoist rope 51 is paid out to lower the tower 34 until the strut 37 lands. At this time, since the jib 35 is moored to the tower 34, the jib 35 does not wobble or become unstable.

[0056] Furthermore, if the winch 16 becomes inoperable when mooring the jib 35 to the tower 34, the rope 14 can be removed from the winch 16 or cut and the rope 14 can be manually reeled out, thereby making it possible to move the unlocking member 12 to the locked position and thus to engage the locked member 3 with the latch 11.

[0057] (Release step) When the jib 35 moored to the tower 34 is to be released from the tower 34, the tower 34 is brought into a vertically erect position by reeling in the boom hoist rope 51 as shown in Fig. 1 while the latch 11 is holding the locked member 3. In this embodiment, the inclination angle of the tower 34 from the horizontal plane is 90 degrees, but this is not limited to this.

[0058] At this time, the directional control valve 6 is switched to the second position 6b (see FIG. 6). In addition, the latch 11 is in the locking position, the unlocking member 12 is in the locking position, and the rotating lever 19 is in the operating position (see FIG. 2). In the driver's cab 33, the unlocked lamp 22 is turned off and the locked lamp 21 is turned on.

[0059] Next, when the unlocking switch 9 is operated, the directional control valve 6 is switched to the first position 6a by the controller 7. As a result, the winch 16 is rotated in one direction. Then, as shown in Fig. 3, the unlocking member 12 moves to the unlocking position, and the latch 11 moves to the release position, and the locked member 3 is released from the locked state.

[0060] When the locked member 3 is released from the locked state, the rotating lever 19 moves to the standby position and the limit switch 18 turns OFF. As a result, the locked lamp 21 goes out and the unlocked lamp 22 lights up. This allows the operator to recognize that the locked member 3 is no longer locked by the latch 11.

[0061] Thereafter, the jib 35 is hoisted so as to swing forward from the tower 34. As a result, the jib 35, which had been drawn to the tower 34, moves away from the tower 34.

[0062] Thereafter, the directional control valve 6 is switched to the second position 6b by the controller 7. As a result, as shown in Fig. 4, the winch 16 is operated in the other direction by the pulling force of the biasing member 13, the lock release member 12 moves to the lock position, and the latch 11 moves to the engaged position. Then, by winding up the jib hoist rope 48, the jib 35 is raised to the horizontal position or higher, and the tower 34 is then hoisted to the working position.

[0063] Furthermore, if the winch 16 becomes inoperable when releasing the jib 35 from the tower 34, the locked state between the latch 11 and the locked member 3 can be released by manually pulling the rope 14.

[0064] (effect) As described above, according to the jib mooring device 1 of this embodiment, when the winch 16 is operated in one direction, the rope 14 is wound on the winch 16 and the unlocking member 12 moves to the unlocked position. This releases the locked state between the latch 11 and the locked member 3. On the other hand, when the winch 16 is operated in the other direction, the rope 14 is unwound from the winch 16 and the unlocking member 12 becomes movable to the locked position. Then, when the unlocking member 12 moves to the locked position by the biasing force of the biasing member 13, the locked member 3 is locked to the latch 11. Here, if the winch 16 breaks down and it becomes impossible to wind up the rope 14, the locked state between the latch 11 and the locked member 3 can be released by manually pulling the rope 14. Furthermore, if the winch 16 breaks down and the rope 14 cannot be paid out, the rope 14 can be removed from the winch 16 or cut, and the rope 14 can be paid out manually, thereby making it possible to move the unlocking member 12 to the locked position, and thus to engage the locked member 3 with the latch 11. This allows the jib 35 to be locked and unlocked manually. Furthermore, the rope 14 is lighter than the connecting body of Patent Document 2, so the mass of the tower 34 can be reduced. Furthermore, the rope 14 does not require assembly, unlike the connecting body, so that the ease of assembly can be improved.

[0065] Furthermore, the winch 16 is operated in one direction when power is supplied from the hydraulic motor 17, whereas when power is not supplied from the hydraulic motor 17, it is operated in the other direction by the tensile force of the urging member 13. Thus, when power is not supplied from the hydraulic motor 17 to the winch 16, the winch 16 can be operated in the other direction by the tensile force of the urging member 13, making it possible to move the unlocking member 12 to the locked position. Furthermore, when power is not supplied from the hydraulic motor 17, for example, in the event that the winch 16 breaks down, the winch 16 is operated in the other direction, thereby preventing the locked state between the latch 11 and the locked member 3 from being unintentionally released.

[0066] Furthermore, when the locked member 3 is locked to the latch 11, the winch 16 is operated in one direction, whereas when the locked member 3 is not locked to the latch 11, the winch 16 is not operated in one direction. As a result, only when the locked member 3 is locked to the latch 11, the unlocking member 12 can be moved to the unlocking position to release the locked state between the latch 11 and the locked member 3. Furthermore, when the locked member 3 is not locked to the latch 11, the urging force of the urging member 13 can make it possible to move the unlocking member 12 to the locked position.

[0067] Furthermore, when the locked member 3 is locked to the latch 11 and a command is received from the unlocking switch 9, the winch 16 is operated in one direction. Even when the locked member 3 is locked to the latch 11, the winch 16 is not operated in one direction if a command is not received from the unlocking switch 9. This makes it possible to prevent the locked state between the latch 11 and the locked member 3 from being unintentionally released.

[0068] In addition, the directional control valve 6 is switched between a first position 6a where the hydraulic oil from the hydraulic pump 5 is supplied to the hydraulic motor 17, and a second position 6b where the hydraulic oil from the hydraulic pump 5 is not supplied to the hydraulic motor 17. When the directional control valve 6 is switched to the first position 6a, the winch 16 is operated in one direction. This allows the unlocking member 12 to be moved to the unlocked position. On the other hand, when the directional control valve 6 is switched to the second position 6b, the winch 16 is not operated in one direction. This allows the unlocking member 12 to be moved to the locked position by the biasing force of the biasing member 13.

[0069] In addition, the pressure of the hydraulic oil supplied to the hydraulic motor 17 is adjusted. For example, by adjusting the pressure of the hydraulic oil so that the driving force of the winch 16 is as small as possible (for example, the minimum) while allowing the latch 11 to move to the release position, the weight of the locking device 2, in particular the unlocking member 12, can be suitably reduced.

[0070] [Second embodiment] Next, a jib mooring device of a second embodiment will be described with reference to the drawings. Note that the description of the configuration common to the first embodiment and the effects achieved thereby will be omitted, and the description will be focused mainly on the points different from the first embodiment. Note that the same members as those in the first embodiment are given the same reference numerals as those in the first embodiment.

[0071] (Configuration of jib mooring device) As shown in Figs. 7 to 9, which are enlarged views of the main part A in Fig. 1, the jib mooring device 101 of this embodiment has a locking device 102 and a locked member 103. The locking device 102 is provided on the front part of the tower 34. The locked member 103 is provided on the jib 35. The locked member 103 is provided at a position facing the locking device 102 when the jib 35 is folded relative to the tower 34. As shown in Fig. 7, the locked member 103 is locked by the locking device 102 when the jib 35 is folded relative to the tower 34. The locked member 103 is locked by the locking device 102 when the jib 35 is folded relative to the tower 34, so that the jib 35 can be moored to the tower 34.

[0072] As shown in Fig. 10, an enlarged plan view of the jib mooring device, the locked member 103 is pipe-shaped and supported by a pair of left and right shaft support brackets 75. The shaft support brackets 75 protrude from a jib side bracket 76 attached to the jib 35 with a U-bolt or the like. A bearing 75a is provided at the tip of the shaft support bracket 75. The locked member 103 is supported by the pair of left and right bearings 75a.

[0073] 7 to 9, the locking device 102 has a lock pin (locking member) 61, an unlocking member 62, and a biasing member 63. The lock pin 61 is rod-shaped and is connected to the front end of the unlocking member 62. The lock pin 61 is movable by rotation of the unlocking member 62 between a locking position (position shown in FIG. 7) where the locked member 103 is locked and a releasing position (position shown in FIG. 8) where the locked member 103 is released from the lock.

[0074] The unlocking member 62 is rotatably connected to a support bracket 65 via a fulcrum pin 65a. The support bracket 65 protrudes upward from a tower side bracket 66 attached to the tower 34 with a U-bolt or the like. A connecting member 69, which will be described later, is connected to the rear end of the unlocking member 62.

[0075] The unlocking member 62 is movable between a locked position (position shown in FIG. 7) where the lock pin 61 is located in the locked position, and an unlocked position (position shown in FIG. 8) where the lock pin 61 is located in the unlocked position.

[0076] A lock frame 67 is attached to the tower side bracket 66. A guide tube 67a is formed in the lock frame 67, and a lock hole 67b is formed at a position opposite to the guide tube 67a. The lock pin 61 is movable between an engagement position where the lock pin 61 fits into the lock hole 67b and a release position where the lock pin 61 is disengaged from the lock hole 67b by moving up and down inside the guide tube 67a.

[0077] The urging member 63 is a spring, and is disposed between the tower side bracket 66 and the lock release member 62. One end of the urging member 63 is attached to the tower side bracket 66, and the other end of the urging member 63 is attached to a portion of the lock release member 62 forward of the fulcrum pin 65a (on the jib 35 side). The urging member 63 urges the lock release member 62 toward the locked position.

[0078] A pin block member 68 is provided within the lock frame 67. The pin block member 68 is movable in the front-rear direction within the lock frame 67 and is biased forward by a spring 68a. As shown in Figures 8 and 9, when the lock pin 61 is in the release position, the pin block member 68 is biased to a position where it blocks a part of the guide tube 67a. As a result, the lock pin 61 is blocked by the pin block member 68 and cannot move to the locking position.

[0079] The locking device 102 also has a connecting member 69, a spring 70, and a rope 14. The connecting member 69 has a first connecting member 69a and a second connecting member 69b. The first connecting member 69a and the second connecting member 69b are connected to each other. The first connecting member 69a has a front end portion rotatably attached to a connecting member support bracket 71 by a pin 71a, and a rear end portion thereof is connected to the lower end portion of the second connecting member 69b. The connecting member support bracket 71 is provided so as to protrude downward from the tower side bracket 66.

[0080] The second connecting member 69b connects the rear end of the unlocking member 62 to the rear end of the first connecting member 69a. An elongated hole 69c is formed in the upper part of the second connecting member 69b (the connecting part with the unlocking member 62) along the axial direction. A connecting pin 72 is engaged with the elongated hole 69c. The unlocking member 62 and the connecting member 69 are connected via the connecting pin 72.

[0081] The rope 14 is connected to the center of the first connecting member 69a. The rope 14 is reeled out from the winch 16 (see FIG. 5). The connecting member 69 connects the lock release member 62 and the rope 14 together.

[0082] The connecting member 69 is movable between an operating position (position shown in FIG. 8) that positions the unlocking member 62 at the unlocked position, and a standby position (position shown in FIGS. 7 and 9) that allows the unlocking member 62 to move between the locked position and the unlocked position. The elongated hole 69c is formed within a range that allows the unlocking member 62 to move between the locked position and the unlocked position when the connecting member 69 is in the standby position.

[0083] The spring (connecting member biasing member) 70 is disposed between the tower side bracket 66 and the first connecting member 69a. One end of the spring 70 is attached to the tower side bracket 66, and the other end of the spring 70 is attached to a portion of the first connecting member 69a on the front side (the jib 35 side) of the portion to which the rope 14 is connected. The spring 70 biases the connecting member 69 toward the standby position.

[0084] When the winch 16 is operated in one direction, the rope 14 is wound onto the winch 16, and the connecting member 69 moves to the operating position. This causes the unlocking member 62 to move to the unlocking position, so that the locked state between the lock pin 61 and the locked member 103 can be released. On the other hand, when the winch 16 is operated in the other direction, the rope 14 is unwound from the winch 16, and the connecting member 69 moves to the standby position by the biasing force of the spring 70. This allows the unlocking member 62 to move between the locked position and the unlocked position, so that the locked member 103 can be locked to the lock pin 61.

[0085] 8, the spring (tensile member) 70 urges the connecting member 69 toward the standby position, thereby pulling the rope 14 in the direction in which the rope 14 is reeled out from the winch 16. When power is not supplied from the hydraulic motor 17, the winch 16 is operated in the other direction by the tensile force of the spring 70. As a result, the rope 14 is reeled out from the winch 16. At this time, the rope 14 is gradually reeled out due to the pipeline resistance of the hydraulic motor 17, etc.

[0086] In this way, when power is not supplied from the hydraulic motor 17 to the winch 16, the tensile force of the spring 70 operates the winch 16 in the other direction to move the connecting member 69 to the standby position, thereby making it possible to move the unlocking member 62 to the locked position. Furthermore, when power is not supplied from the hydraulic motor 17, for example in the event that the winch 16 breaks down, the winch 16 is operated in the other direction, so that the locked state between the lock pin 61 and the locked member 103 is not unintentionally released.

[0087] In addition, the jib mooring device 1 has a detection device 104. The detection device 104 detects whether or not the locked member 103 is locked by the lock pin 61. The detection device 104 has a first limit switch 77 and a second limit switch 78.

[0088] The first limit switch 77 is attached to the tower side bracket 66. The first limit switch 77 has a lever 77a extending forward. A striker 62a is attached to the front end of the lock release member 62. The first limit switch 77 turns ON when the lever 77a is pressed by the striker 62a, and turns OFF when the striker 62a separates from the lever 77a. In this way, the first limit switch 77 detects whether or not the lock pin 61 is located at the locking position.

[0089] The second limit switch 78 is attached to the tower side bracket 66. The second limit switch 78 has a lever 78a extending in a direction perpendicular to the plane of the paper in FIG. 7 (see FIG. 10). The second limit switch 78 turns ON when the lever 78a is pressed by the unlocking member 62, and turns OFF when the unlocking member 62 separates from the lever 78a. In this way, the second limit switch 78 detects whether or not the unlocking member 62 is located in the unlocked position.

[0090] A stopper 79 is provided near the second limit switch 78. The stopper 79 is attached to the tower side bracket 66. As shown in Fig. 8, when the unlocking member 62 is located in the unlocked position, the unlocking member 62 abuts against the stopper 79, thereby restricting the rotation of the unlocking member 62. This prevents the second limit switch 78 from being destroyed by the unlocking member 62.

[0091] 11 which is a hydraulic circuit diagram of the jib mooring device 101, a signal from a first limit switch 77 and a signal from a second limit switch 78 are input to the controller 7. The controller 7 determines whether or not the locked member 103 is locked by the lock pin 61 based on the signals from the first limit switch 77 and the second limit switch 78.

[0092] When the locked member 103 is locked by the lock pin 61 (see FIG. 7), the controller 7 switches the directional control valve 6 to the first position 6a to operate the winch 16 in one direction. This causes the unlocking member 62 to move to the unlocked position. On the other hand, when the locked member 103 is not locked by the lock pin 61 (see FIG. 9), the controller 7 switches the directional control valve 6 to the second position 6b to not operate the winch 16 in one direction. This causes the unlocking member 62 to be located at the unlocked position, and to be able to move to the locked position by the biasing force of the biasing member 63.

[0093] In this way, only when the locked member 103 is locked to the lock pin 61, the unlocking member 62 can be moved to the unlocked position to release the locked state between the lock pin 61 and the locked member 103. Also, when the locked member 103 is not locked to the lock pin 61, the biasing force of the biasing member 63 can make it possible to move the unlocking member 62 to the locked position.

[0094] When the locked member 103 is locked to the lock pin 61 and a command is received from the unlocking switch 9, the controller 7 controls the directional control valve 6 to operate the winch 16 in one direction. When the locked member 103 is locked to the lock pin 61 and a command is not received from the unlocking switch 9, the controller 7 does not control the directional control valve 6 to operate the winch 16 in one direction. Therefore, even if the locked member 103 is locked to the lock pin 61, the winch 16 is not operated in one direction unless a command is received from the unlocking switch 9. This makes it possible to prevent the locked state between the lock pin 61 and the locked member 103 from being unintentionally released.

[0095] In the above configuration, when the folded jib 35 is moored to the tower 34, the tower 34 is brought into a vertically erected position as shown in FIG. 1. In this state, the jib 35 is hung down. When the jib 35 is hung down, the locked member 103 comes into contact with the pin block member 68 as shown in FIG. 9, and pushes the pin block member 68 toward the tower 34 against the biasing force of the spring 68a. As a result, the lock pin 61 is unblocked by the pin block member 68, and the lock release member 62 moves to the lock position due to the biasing force of the biasing member 63 as shown in FIG. 7, and at the same time, the lock pin 61 moves to the locking position, and the jib 35 is moored to the tower 34.

[0096] On the other hand, when the jib 35 moored to the tower 34 is released from the tower 34, the tower 34 is brought into a vertically erected position with the lock pin 61 engaged with the engaged member 103, as shown in FIG. 7. In this state, the winch 16 is rotated in one direction. Then, the rope 14 is wound and the connecting member 69 moves to the operating position. As a result, as shown in FIG. 8, the lock release member 62 moves to the unlocked position and at the same time, the lock pin 61 moves to the unlocked position. Then, the engaged member 103 is pushed by the pin block member 68 by the urging force of the spring 68a, and the engaged state of the engaged member 103 is released. At this time, the jib 35 is raised and lowered so as to swing forward from the tower 34, and the jib 35 that has been drawn to the tower 34 moves away from the tower 34. At this time, the lock pin 61 is blocked by the pin block member 68, and the lock pin 61 does not return to the engaged position.

[0097] In consideration of the need to change the mounting positions when the lengths of the tower 34 and the jib 35 are changed, and of transportability, it is preferable to detachably mount the tower side bracket 66 to the main pipe of the tower 34 with a U-bolt or the like. Similarly, it is preferable to detachably mount the jib side bracket 76 to the main pipe of the jib 35 with a U-bolt or the like.

[0098] (Jib mooring operation) Next, the operation of the jib mooring device 101 will be described with reference to Figs.

[0099] (Mooring step) When mooring the folded jib 35 to the tower 34, first, as shown in Fig. 1, the boom hoisting rope 51 is wound up to bring the tower 34 into a vertically erect position. In this embodiment, the inclination angle of the tower 34 from the horizontal plane is 90 degrees, but is not limited to this.

[0100] Next, the jib hoist rope 48 is let out to hang the jib 35 vertically. At this time, the directional control valve 6 is switched to the second position 6b (see FIG. 11). Also, the lock pin 61 is in the release position, the unlocking member 62 is in the unlocking position, and the connecting member 69 is in the standby position (see FIG. 9). The second limit switch 78 is turned ON by the lever 78a being pressed by the unlocking member 62. Therefore, in the operator's cab 33, the unlocked lamp 22 is lit and the locked lamp 21 is turned off.

[0101] When the locked member 103 comes sufficiently close to the locking device 102, as shown in Fig. 9, the locked member 103 comes into contact with the pin block member 68 and pushes the pin block member 68 toward the tower 34 against the biasing force of the spring 68a. As a result, as shown in Fig. 7, the lock release member 62 moves to the lock position and at the same time, the lock pin 61 moves to the locking position, and the locked member 103 is locked by the lock pin 61. As a result, the jib 35 is moored to the tower 34. The connecting member 69 remains in the standby position.

[0102] When the locked member 103 is locked by the lock pin 61, the second limit switch 78 is turned OFF. Also, the lever 77a of the first limit switch 77 is pressed by the striker 62a, and the first limit switch 77 is turned ON. As a result, the non-locking lamp 22 is turned off and the locking lamp 21 is turned on. This enables the operator to recognize that the locked member 103 is locked by the lock pin 61.

[0103] Next, the boom hoist rope 51 is paid out to lower the tower 34 until the strut 37 lands. At this time, since the jib 35 is moored to the tower 34, the jib 35 does not wobble or become unstable.

[0104] If the winch 16 becomes inoperable when mooring the jib 35 to the tower 34, the rope 14 can be removed from the winch 16 or cut and the rope 14 can be manually reeled out, thereby making it possible to move the unlocking member 62 to the locked position and thus to engage the locked member 103 with the lock pin 61.

[0105] (Release step) When releasing the jib 35 moored to the tower 34 from the tower 34, the tower 34 is brought into a vertically erect position by reeling in the boom hoist rope 51 as shown in Fig. 1 with the locked member 103 locked by the lock pin 61. In this embodiment, the inclination angle of the tower 34 from the horizontal plane is 90 degrees, but is not limited to this.

[0106] At this time, the directional control valve 6 is switched to the second position 6b (see FIG. 11). In addition, the lock pin 61 is in the lock position, the unlocking member 62 is in the lock position, and the connecting member 69 is in the standby position (see FIG. 7). The first limit switch 77 is turned ON when the lever 77a is pressed by the striker 62a. Therefore, in the operator's cab 33, the lock lamp 21 is turned on and the non-lock lamp 22 is turned off.

[0107] Next, when the lock release switch 9 is operated, the directional control valve 6 is switched to the first position 6a by the controller 7. As a result, the winch 16 is rotated in one direction. Then, the rope 14 is wound and the connecting member 69 moves to the operating position. As a result, as shown in FIG. 8, the lock release member 62 moves to the lock release position and at the same time, the lock pin 61 moves to the release position. Then, the biasing force of the spring 68a presses the locked member 103 against the pin block member 68, and the locked state of the locked member 103 is released.

[0108] When the locked state of the locked member 103 is released, the first limit switch 77 turns OFF. Also, the lever 78a of the second limit switch 78 is pressed by the unlocking member 62, and the second limit switch 78 turns ON. As a result, the locked lamp 21 turns off and the unlocked lamp 22 turns on. This enables the operator to recognize that the locked member 3 is not locked by the lock pin 61.

[0109] When the second limit switch 78 is turned ON, the directional control valve 6 is switched to the second position 6b by the controller 7. As a result, as shown in Fig. 9, the winch 16 is actuated in the other direction by the tensile force of the spring 70, and the connecting member 69 moves to the standby position. The lock release member 62 remains in the lock release position, and the lock pin 61 remains in the release position.

[0110] Thereafter, the jib 35 is hoisted so as to swing it forward from the tower 34. As a result, the jib 35, which had been drawn to the tower 34, moves away from the tower 34. Then, by winding up the jib hoist rope 48, the jib 35 is raised to horizontal or higher, and the tower 34 is then hoisted to the working position.

[0111] Furthermore, if the winch 16 becomes inoperable when releasing the jib 35 from the tower 34, the locked state between the lock pin 61 and the locked member 103 can be released by manually pulling the rope 14.

[0112] (effect) As described above, according to the jib mooring device 101 of this embodiment, when the winch 16 is operated in one direction, the rope 14 is wound onto the winch 16 and the connecting member 69 moves to the operating position. This causes the unlocking member 62 to move to the unlocking position, so that the locked state between the lock pin 61 and the locked member 103 can be released. On the other hand, when the winch 16 is operated in the other direction, the rope 14 is unwound from the winch 16 and the connecting member 69 moves to the standby position by the biasing force of the spring 70. This causes the unlocking member 62 to be movable between the locked position and the unlocked position, so that the locked member 103 can be locked to the lock pin 61.

[0113] [Third embodiment] Next, a jib mooring device of a third embodiment will be described with reference to the drawings. Note that the description of the configuration common to the first embodiment and the effects achieved thereby will be omitted, and the description will be focused mainly on the points different from the first embodiment. Note that the same members as those in the first embodiment are given the same reference numerals as those in the first embodiment.

[0114] (Tower crane configuration) A side view of the tower crane 30 in the third embodiment is shown in Fig. 12. The configuration of the tower crane 30 in this embodiment is the same as the configuration of the tower crane 30 in the first and second embodiments.

[0115] In the first and second embodiments, the tower 34 is in a vertically upright position, as shown in Fig. 1, and the jib 35 is moored and released. In contrast, in this embodiment, the tower 34 is in a position tilted forward with respect to the vertical direction, as shown in Fig. 12, and the jib 35 is moored and released. Therefore, the tower 34 looks stable, and there is no risk of the tower 34 tipping backward due to strong winds.

[0116] (Configuration of jib mooring device) As shown in Figs. 13 to 16, which are enlarged views of the main part C in Fig. 12, the jib mooring device 201 of this embodiment has a locking device 202 and a locked member 203. The locking device 202 is provided on the front part of the tower 34. The locked member 203 is provided on the jib 35. The locked member 203 is provided at a position facing the locking device 202 when the jib 35 is folded relative to the tower 34. As shown in Fig. 13, the locked member 203 is locked by the locking device 202 when the jib 35 is folded relative to the tower 34. The locked member 203 is locked by the locking device 202 when the jib 35 is folded relative to the tower 34, so that the jib 35 can be moored to the tower 34.

[0117] The locked member 203 is rod-shaped and is attached to the main pipe of the jib 35 with a U-bolt or the like.

[0118] As shown in Fig. 17 which is an enlarged view of a main part D in Fig. 13, and Figs. 18 and 19 which are enlarged views of a main part E in Fig. 14, the locking device 202 has a hook (locking member) 81, an unlocking member 82, a biasing member 83, and a rope 14. The hook 81 is hook-shaped. The hook 81 is rotatably connected to a bracket 84 provided on the ventral side of the tower 34 by a fulcrum pin 84a.

[0119] The hook 81 has a fitting portion 81a into which the locked member 203 fits, and a guide portion 81b that guides the locked member 203 to the fitting portion 81a. The guide portion 81b has an inclined surface that is inclined from the tip of the hook 81 to the fitting portion 81a.

[0120] Hook 81 can rotate around fulcrum pin 84a to move between an engagement position (position shown in Figure 17) in which it engages interlocking member 203 and a release position (position shown in Figure 18) in which it releases the engagement of interlocking member 203.

[0121] The bracket 84 is provided with a locking side stopper 84b and a release side stopper 84c. As shown in Fig. 17, when the hook 81 is located at the locking position, the side surface of the hook 81 abuts against the locking side stopper 84b, thereby restricting the rotation of the hook 81. Also, as shown in Fig. 18, when the hook 81 is located at the release position, the side surface of the hook 81 abuts against the release side stopper 84c, thereby restricting the rotation of the hook 81.

[0122] The front end of the unlocking member 82 is connected to the base end of the hook 81. The rear end of the unlocking member 82 is connected to the rope 14.

[0123] The unlocking member 82 can be moved by rotation of the hook 81 between a locked position (position shown in Figure 13) in which the hook 81 is positioned in the engaged position, and an unlocked position (position shown in Figure 14) in which the hook 81 is positioned in the released position.

[0124] The biasing member 83 is a spring, and is disposed between the hook 81 and the bracket 84. One end of the biasing member 83 is attached to a portion of the hook 81 rearward (toward the tower 34) of the fitting portion 81a, and the other end of the biasing member 83 is attached to the lower end of the bracket 84. The biasing member 83 biases the hook 81 toward the locking position. In other words, the biasing member 83 biases the unlocking member 82 toward the locking position.

[0125] 18, the biasing member (pulling member) 83 biases the lock release member 82 toward the locked position, thereby pulling the rope 14 in the direction in which the rope 14 is reeled out from the winch 16. When power is not supplied from the hydraulic motor 17, the winch 16 is operated in the other direction by the pulling force of the biasing member 83. As a result, the rope 14 is reeled out from the winch 16. At this time, the rope 14 is gradually reeled out due to the pipeline resistance of the hydraulic motor 17, etc.

[0126] In this way, when power is not supplied from the hydraulic motor 17 to the winch 16, the winch 16 can be operated in the other direction by the pulling force of the biasing member 83, making it possible to move the unlocking member 82 to the locked position. Furthermore, when power is not supplied from the hydraulic motor 17, for example in the event that the winch 16 breaks down, the winch 16 is operated in the other direction, so that the locked state between the hook 81 and the locked member 203 is not unintentionally released.

[0127] In addition, the jib mooring device 201 has a detection device 204. The detection device 204 detects whether or not the locked member 203 is locked to the hook 81. The detection device 204 has an angle detector 85, a rotating lever 86, and a spring 87.

[0128] The angle detector 85 is provided on a fulcrum pin 86a of the rotating lever 86. The angle detector 85 detects the rotation angle of the rotating lever 86. From the rotation angle of the rotating lever 86, it is detected that the rotating lever 86 is positioned at a standby position or a locking position, which will be described later.

[0129] The rotating lever 86 is rotatably attached to the hook 81 via a fulcrum pin 86a. The rotating lever 86 is movable between a standby position (position shown in FIG. 18) where the rotating lever 86 overlaps with the fitting portion 81a of the hook 81 to close the fitting portion 81a, and an operating position (position shown in FIG. 17) where the rotating lever 86 moves away from the fitting portion 81a to open the fitting portion 81a.

[0130] The spring 87 is disposed between the hook 81 and the rotating lever 86. One end of the spring 87 is attached to a protrusion 81c that protrudes upward from the hook 81, and the other end of the spring 87 is attached to a rear end of the rotating lever 86. The spring 87 biases the rotating lever 86 toward the standby position. In the standby position shown in FIG. 18, the front end of the rotating lever 86 abuts against a stopper 81d provided on the hook 81. This restricts the rotation of the rotating lever 86, and prevents the front end of the rotating lever 86 from coming off the hook 81.

[0131] As shown in Fig. 17, when the hook 81 moves to the locking position, the rotating lever 86 moves to the operating position against the biasing force of the spring 87. The positioning of the rotating lever 86 to the operating position is detected by the angle detector 85. On the other hand, as shown in Fig. 18, when the hook 81 moves to the release position, the rotating lever 86 moves to the standby position by the biasing force of the spring 20. The positioning of the rotating lever 86 to the standby position is detected by the angle detector 85.

[0132] The jib mooring device 201 also has a drive mechanism 210. When the folded jib 35 is moored to the tower 34, the drive mechanism 210 draws the hanging jib 35 to the tower 34 with the tower 34 inclined forward with respect to the vertical direction. When the jib 35 moored to the tower 34 is released from the tower 34, the drive mechanism 210 separates the jib 35 drawn to the tower 34 from the tower 34 with the tower 34 inclined forward with respect to the vertical direction.

[0133] The drive mechanism 210 has an engaging member 88 and a moving means 89. The engaging member 88 is provided on the tower 34. The engaging member 88 is long, and has an engaging portion (hook) 88a at its tip portion that can engage with the locked member 203. The engaging portion 88a can engage with the locked member 203 from below the locked member 203. It should be noted that the portion of the engaging member 88 where the engaging portion 88a is provided is not limited to the tip portion.

[0134] The moving means 89 is provided on the ventral side portion of the tower 34. The moving means 89 moves the engaging portion 88a of the engaging member 88 between a first position (see Figs. 13 and 14) close to the ventral surface of the tower 34 and a second position (see Fig. 15) away from the tower 34. The moving means 89 also moves the engaging portion 88a of the engaging member 88 between the second position (see Fig. 15) and a third position (see Fig. 16). Here, the third position is away from the tower 34 and is located on the opposite side of the first position (see Fig. 14) with respect to the second position (see Fig. 15).

[0135] The engaging member 88 and the moving means 89 are provided at both ends of the tower 34 in a direction perpendicular to the paper plane of Figures 17 to 19. The locked member 203 extends in a direction perpendicular to the paper plane of Figures 17 to 19, and both ends protrude from both side surfaces of the jib 35. Note that only one set of the engaging member 88 and the moving means 89 may be provided in the center of the tower 34 in the direction perpendicular to the paper plane of Figures 17 to 19.

[0136] The moving means 89 has a guide member 91, a link member 92, and a moving member 93 (see Figs. 13 to 16). The guide member 91 is a long member that is aligned along the abdominal surface of the tower 34. The engaging member 88 is engaged with the guide member 91 so as to be rotatable and movable in the longitudinal direction of the tower 34.

[0137] The guide member 91 is formed with a guide groove 91a and an extension groove 91b. The extension groove 91b is continuous with the guide groove 91a. The base end of the engagement member 88 is rotatably engaged with either the guide groove 91a or the extension groove 91b. The guide groove 91a guides the engagement member 88 to be movable in the longitudinal direction of the tower 34.

[0138] The extension groove 91b is formed so that the end opposite the guide groove 91a is located closer to the rear surface of the tower 34 than the end on the guide groove 91a side.

[0139] The portion of the engaging member 88 that engages with the guide groove 91a and the extension groove 91b is not limited to the base end. Also, the engaging member 88 may be guided by a rail or the like instead of the guide groove 91a and the extension groove 91b.

[0140] The link member (rotation limiting means) 92 limits the rotation of the engagement member 88. One end of the link member 92 is rotatably connected to a bracket 84 provided on the ventral side portion of the tower 34 by a fulcrum pin 84a. The above-mentioned hook 81 is also rotatably connected to the bracket 84 by a fulcrum pin 84a. The other end of the link member 92 is rotatably connected to an intermediate portion of the engagement member 88 by a pin 88b. The portion of the engagement member 88 to which the other end of the link member 92 is connected is not limited to the intermediate portion. The bracket 84 may be integral with the guide member 91.

[0141] As shown in Figs. 13 to 16, the moving member 93 is a cylinder arranged along the longitudinal direction of the tower 34. In this embodiment, the moving member 93 is a hydraulic cylinder, but it may be an electric cylinder. The tip clevis of the cylinder rod of the moving member 93 is connected to the base end of the engagement member 88 by a pin 94 that passes through a guide groove 91a (see Figs. 17 to 19). The moving member 93 arranged on the front side of the paper in Figs. 13 to 16 and the moving member 93 arranged on the back side of the paper in Figs. 13 to 16 are driven synchronously.

[0142] In this embodiment, as shown in Figures 13 and 14, when the telescopic length of the cylinder rod of the moving member 93 is fully contracted, the engaging portion 88a of the engaging member 88 is located at the first position. Also, as shown in Figure 15, when the telescopic length of the cylinder rod of the moving member 93 is extended to a set length, the base end of the engaging member 88 is located at the end of the extension groove 91b on the guide groove 91a side, and the engaging portion 88a of the engaging member 88 is located at the second position.

[0143] Furthermore, as shown in FIG. 16, when the extension length of the cylinder rod of the movable member 93 is fully extended, the base end of the engaging member 88 is positioned at the end opposite the guide groove 91a of the extension groove 91b, and the engaging portion 88a of the engaging member 88 is positioned at the third position.

[0144] With the tower 34 in a position tilted forward with respect to the vertical direction, the hanging jib 35 can be drawn to the tower 34 by moving the engaging portion 88a of the engaging member 88 from the second position to the first position. Also, with the tower 34 in a position tilted forward with respect to the vertical direction, the engaging portion 88a of the engaging member 88 can be moved from the first position to the second position, so that the jib 35 drawn to the tower 34 can be separated from the tower 34.

[0145] A retention valve (not shown) that controls the extension of the cylinder rod is attached to the moving member 93. Therefore, for example, if the driving pipe (not shown) of the moving member 93 is damaged, the extension of the cylinder rod is prevented. This prevents the cylinder rod from extending unnecessarily in an emergency.

[0146] 20 which is a hydraulic circuit diagram of the jib mooring device 201, a signal from an angle detector 85 is input to the controller 7. Based on the signal from the angle detector 85, the controller 7 determines whether or not the locked member 203 is locked to the hook 81.

[0147] When the locked member 203 is locked to the hook 81 (see FIG. 17), the controller 7 switches the directional control valve 6 to the first position 6a to operate the winch 16 in one direction. This causes the lock release member 82 to move to the unlocked position. On the other hand, when the locked member 203 is not locked to the hook 81 (see FIG. 18), the controller 7 switches the directional control valve 6 to the second position 6b to not operate the winch 16 in one direction. This allows the lock release member 82 to move to the locked position by the biasing force of the biasing member 83.

[0148] In this way, only when the locked member 203 is locked to the hook 81, the unlocking member 82 can be moved to the unlocking position to release the locked state between the hook 81 and the locked member 203. Also, when the locked member 203 is not locked to the hook 81, the biasing force of the biasing member 83 can make it possible to move the unlocking member 82 to the locked position.

[0149] In addition, the jib mooring device 201 has a directional control valve 211. The directional control valve 211 is disposed between the hydraulic pump 5 and the directional control valve 6. The directional control valve 211 switches the operation of the moving member 93.

[0150] The directional control valve 211 is switchable among a contracted position 211a, a neutral position 211b, and an extended position 211c. At the contracted position 211a, hydraulic oil from the hydraulic pump 5 is supplied to the rod side of the moving member 93. This causes the extension length of the cylinder rod of the moving member 93 to be contracted. At the neutral position 211b, hydraulic oil from the hydraulic pump 5 is not supplied to the moving member 93, but is supplied to the hydraulic motor 17. At the extended position 211c, hydraulic oil from the hydraulic pump 5 is supplied to the bottom side of the moving member 93. This causes the extension length of the cylinder rod of the moving member 93 to be extended.

[0151] In addition, the jib mooring device 201 has a jib retracting switch 212 and a jib swinging switch 213. The jib retracting switch 212 and the jib swinging switch 213 are provided in the cab 33, and are operated by an operator (worker) who operates the tower crane 30.

[0152] The jib pull-together switch 212 outputs a command to lock the hook 81 to the locked member 203 when operated by an operator. The controller 7 receives the command from the jib pull-together switch 212 and controls the directional control valve 211 to contract the extension length of the cylinder rod of the moving member 93. This causes the jib 35 to be pulled toward the tower 34. Details will be described later.

[0153] The jib swing-out switch (output device) 213, when operated by an operator, outputs a command to release the locked state between the hook 81 and the locked member 203. The controller 7 receives the command from the jib swing-out switch 213 and controls the directional control valve 211 so as to extend the telescopic length of the cylinder rod of the moving member 93. This causes the jib 35 to move away from the tower 34. This will be described in detail later. The controller 7 also receives the command from the jib swing-out switch 213 and controls the directional control valve 6 so as to operate the winch 16 in one direction. This causes the hook 81 to move away from the locked member 203.

[0154] Here, when the locked member 203 is locked to the hook 81 and a command is received from the jib swing-out switch 213, the controller 7 controls the directional control valve 6 to operate the winch 16 in one direction. When the locked member 203 is locked to the hook 81 and a command is not received from the jib swing-out switch 213, the controller 7 does not control the directional control valve 6 to operate the winch 16 in one direction. Therefore, even if the locked member 203 is locked to the hook 81, the winch 16 is not operated in one direction unless a command is received from the jib swing-out switch 213. This makes it possible to prevent the locked state between the hook 81 and the locked member 203 from being unintentionally released.

[0155] Here, the controller 7 controls the directional control valve 6 to operate the winch 16 in one direction based on a signal from the angle detector 85, and when the hook 81 and the locked member 203 are released from the locked state, the controller 7 controls the moving member 93 to move the engaging portion 88a of the engaging member 88 from the first position to the second position. After that, the controller 7 controls the directional control valve 6 to operate the winch 16 in the other direction. That is, upon receiving a command from the jib swing switch 213, the controller 7 first switches the directional control valve 6 to the first position 6a to operate the winch 16 in one direction. Then, after the hook 81 and the locked member 3 are released from the locked state, the controller 7 switches the directional control valve 6 to the second position 6b, and switches the directional control valve 211 from the neutral position 211b to the extended position 211c to extend the extension length of the cylinder rod of the moving member 93. Then, after the engaging portion 88a of the engaging member 88 has moved to the second position, the directional control valve 211 is switched to the neutral position 211b, whereby the winch 16 operates in the other direction.

[0156] When the jib 35, which is pulled to the tower 34, is moved away from the tower 34 with the tower 34 inclined forward with respect to the vertical direction, if the engaging portion 88a of the engaging member 88 is moved from the first position to the second position before the hook 81 is released from the locked member 203, the engaging portion 88a is separated from the locked member 203. In this state, if the hook 81 is released from the locked member 203, the jib 35 is swung out with force, and the locked member 203 may hit the engaging portion 88a and damage the engaging portion 88a. Therefore, by moving the engaging portion 88a of the engaging member 88 from the first position to the second position after the hook 81 is released from the locked member 203, the jib 35 can be gently suspended.

[0157] In consideration of the need to change the mounting positions when the lengths of the tower 34 and the jib 35 are changed, and of transportability, it is preferable to detachably mount each of the guide member 91, the bracket 84, and the moving member 93 to the main pipe of the tower 34 with a U-bolt or the like. Similarly, it is preferable to detachably mount the locked member 203 to the main pipe of the jib 35 with a U-bolt or the like.

[0158] In the above configuration, when the folded jib 35 is moored to the tower 34, the tower 34 is inclined forward with respect to the vertical direction as shown in FIG. 12. In this state, the engaging portion 88a of the engaging member 88 is moved from the first position to the third position as shown in FIG. 16. Thereafter, the jib 35 is hung down. Then, as shown in FIG. 15, the engaging portion 88a of the engaging member 88 is moved to the second position, and the engaging portion 88a is engaged with the locked member 203. Thereafter, as shown in FIG. 14, when the extension length of the cylinder rod of the moving member 93 is contracted, the hanging jib 35 is drawn toward the tower 34.

[0159] When the locked member 203 approaches the hook 81, the locked member 203 comes into contact with the guide portion 81b of the hook 81. Then, the locked member 203 slides along the guide portion 81b and is guided toward the fitting portion 81a. Then, as shown in FIG. 17, the locked member 203 fits into the fitting portion 81a, so that the locked member 203 is locked by the hook 81.

[0160] When the extension length of the cylinder rod of the movable member 93 is fully contracted, the engaging portion 88a of the engaging member 88 is located at the first position, and the jib 35 is moored to the tower 34.

[0161] On the other hand, when the jib 35 moored to the tower 34 is released from the tower 34, the tower 34 is tilted forward with respect to the vertical direction with the locked member 203 locked by the hook 81, as shown in Fig. 17. In this state, the rope 14 is pulled, and the locked member 203 is released from the engaging portion 88a of the engaging member 88, as shown in Fig. 18.

[0162] Thereafter, the telescopic length of the cylinder rod of the movable member 93 is extended, thereby moving the engaging portion 88a of the engaging member 88 from the first position to the second position. Then, the jib 35, which had been attracted to the tower 34, moves away from the tower 34. Then, as shown in FIG. 15, when the telescopic length of the cylinder rod of the movable member 93 is extended to the set length, the engaging portion 88a of the engaging member 88 is positioned at the second position, and the jib 35 hangs down.

[0163] Thereafter, when the engaging portion 88a of the engaging member 88 is moved to the third position as shown in FIG. 16, the engagement between the engaging portion 88a of the engaging member 88 and the locked member 203 is released.

[0164] (Jib mooring operation) Next, the operation of the jib mooring device 201 will be described with reference to FIGS.

[0165] (Mooring step) When mooring the folded jib 35 to the tower 34, first, the boom hoist rope 51 is let out to place the tower 34 in a position tilted forward with respect to the vertical direction, as shown in Fig. 12. In this embodiment, the inclination angle of the tower 34 from the horizontal plane is 80 degrees, but the inclination angle is not limited to this.

[0166] 16, the cylinder rod of the moving member 93 is extended to its maximum length, thereby moving the engaging portion 88a of the engaging member 88 from the first position to the third position. Then, the jib hoist rope 48 is reeled out to hang the jib 35 down vertically.

[0167] At this time, the directional control valve 6 is switched to the second position 6b, and the directional control valve 211 is switched to the neutral position 211b (see FIG. 20). In addition, the hook 81 is in the locking position, the lock release member 82 is in the locking position, and the rotating lever 86 is in the standby position (see FIG. 19). In the operator's cab 33, the unlocked lamp 22 is on, and the locked lamp 21 is off.

[0168] Next, when the jib retract switch 212 is operated, the directional control valve 211 is switched to the contracted position 211a by the controller 7. As a result, as shown in Fig. 15, the extension length of the cylinder rod of the moving member 93 is contracted to the set length, whereby the engaging portion 88a of the engaging member 88 is moved from the third position to the second position, and the engaging portion 88a is engaged with the locked member 203.

[0169] Thereafter, as shown in FIG. 19, the extension length of the cylinder rod of the moving member 93 is contracted, thereby drawing the hanging jib 35 towards the tower 34.

[0170] When the locked member 203 approaches the hook 81, the locked member 203 comes into contact with the guide portion 81b of the hook 81. Then, the locked member 203 is guided toward the fitting portion 81a while sliding along the guide portion 81b. Then, as shown in FIG. 17, the locked member 203 fits into the fitting portion 81a, so that the locked member 203 is locked to the hook 81.

[0171] 13, the extension length of the cylinder rod of the moving member 93 is contracted to the maximum, thereby moving the engaging portion 88a of the engaging member 88 to the first position. As a result, the jib 35 is moored to the tower 34.

[0172] When the locked member 203 fits into the fitting portion 81a, the rotating lever 86 moves to the operating position, which is detected by the angle detector 85. As a result, the directional control valve 211 is switched to the neutral position 211b. In addition, the non-locking lamp 22 goes out and the locking lamp 21 goes on. This allows the operator to recognize that the locked member 203 is locked to the hook 81.

[0173] Next, the boom hoist rope 51 is paid out to lower the tower 34 until the strut 37 lands. At this time, since the jib 35 is moored to the tower 34, the jib 35 does not wobble or become unstable.

[0174] Furthermore, if the winch 16 becomes inoperable when mooring the jib 35 to the tower 34, the rope 14 can be removed from the winch 16 or cut, and the rope 14 can be manually reeled out, thereby making it possible to move the unlocking member 82 to the locked position, and thus to engage the engaged member 203 with the hook 81.

[0175] (Release step) When releasing the jib 35 moored to the tower 34 from the tower 34, the boom hoist rope 51 is wound up as shown in Fig. 12 with the locked member 203 locked by the hook 81, so that the tower 34 is tilted forward relative to the vertical direction. In this embodiment, the inclination angle of the tower 34 from the horizontal plane is 80 degrees, but the inclination angle is not limited to this.

[0176] At this time, the directional control valve 6 is switched to the second position 6b, and the directional control valve 211 is switched to the neutral position 211b (see FIG. 20). In addition, the hook 81 is in the locking position, the lock release member 82 is in the locking position, and the rotating lever 86 is in the operating position (see FIG. 17). In the operator's cab 33, the lock lamp 21 is on, and the non-lock lamp 22 is off.

[0177] Next, when the jib swing-out switch 213 is operated, the directional control valve 6 is switched to the first position 6a by the controller 7. As a result, the winch 16 is rotated in one direction. Then, as shown in Fig. 18, the unlocking member 82 moves to the unlocking position, and the hook 81 moves to the release position, and the locked state of the locked member 203 is released.

[0178] When the locked member 203 is released from the locked state, the rotating lever 86 moves to the standby position, which is detected by the angle detector 85. As a result, the locked lamp 21 goes out and the unlocked lamp 22 goes on. This allows the operator to recognize that the locked member 203 is no longer locked by the hook 81.

[0179] Thereafter, the controller 7 switches the directional control valve 6 to the second position 6b, and switches the directional control valve 211 to the extended position 211c. As a result, the telescopic length of the cylinder rod of the moving member 93 is extended. Then, as shown in FIG. 15, the engaging portion 88a of the engaging member 88 moves to the second position. As a result, the jib 35, which has been attracted to the tower 34, moves away from the tower 34. When the telescopic length of the cylinder rod of the moving member 93 is further extended, the engaging portion 88a of the engaging member 88 moves to the third position, and the engaging portion 88a and the locked member 203 are disengaged from each other, as shown in FIG. 16.

[0180] After that, the directional control valve 211 is switched to the neutral position 211b by the controller 7. As a result, the winch 16 is operated in the other direction by the tension of the spring 70, and the unlocking member 82 moves to the locked position, and at the same time, the hook 81 moves to the engaged position. Then, the jib hoisting rope 48 is wound up, so that the jib 35 is raised to the horizontal position or higher. Then, the extension length of the cylinder rod of the moving member 93 is contracted to the maximum, so that the engaging portion 88a of the engaging member 88 moves from the third position to the first position. Then, the tower 34 is hoisted to the working position.

[0181] Furthermore, if the winch 16 becomes inoperable when releasing the jib 35 from the tower 34, the engagement between the hook 81 and the engaged member 203 can be released by manually pulling the rope 14.

[0182] (effect) As described above, according to the jib mooring device 201 of this embodiment, the engaging portion 88a of the engaging member 88 is moved between the first position and the second position. Therefore, by moving the engaging portion 88a of the engaging member 88 from the second position to the first position with the tower 34 in a state in which it is tilted forward with respect to the vertical direction, the hanging jib 35 can be drawn to the tower 34. Also, by moving the engaging portion 88a of the engaging member 88 from the first position to the second position with the tower 34 in a state in which it is tilted forward with respect to the vertical direction, the jib 35 drawn to the tower 34 can be separated from the tower 34.

[0183] In addition, when the winch 16 is operated in one direction and the hook 81 is released from the locked member 203, the engaging portion 88a of the engaging member 88 is moved from the first position to the second position. When the jib 35, which is pulled to the tower 34, is moved away from the tower 34 with the tower 34 tilted forward with respect to the vertical direction, if the engaging portion 88a of the engaging member 88 is moved from the first position to the second position before the hook 81 is released from the locked member 203, the engaging portion 88a is separated from the locked member 203. In this state, when the hook 81 is released from the locked member 203, the jib 35 is swung out with force, and the locked member 203 may hit the engaging portion 88a and damage the engaging portion 88a. Therefore, after releasing the engagement between the hook 81 and the engaged member 203, the engagement portion 88a of the engagement member 88 can be moved from the first position to the second position, thereby allowing the jib 35 to be gently suspended.

[0184] Although the embodiments of the present invention have been described above, they are merely illustrative examples and do not limit the present invention, and the specific configurations and the like can be appropriately modified in design. Furthermore, the actions and effects described in the embodiments of the invention are merely a list of the most preferable actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to those described in the embodiments of the present invention.

[0185] For example, the motor that operates the winch 16 may be an electric motor instead of the hydraulic motor 17.

[0186] In addition, a cam clutch may be provided between the hydraulic motor 17 and the winch 16 so that the power from the hydraulic motor 17 causes the winch 16 to operate in only one direction.

[0187] Also, a detection means for detecting the tilt angle of the tower 34 may be provided and configured to input the detection signal to the controller 7, and the controller 7 may receive a command from the lock release switch 9 (jib swing-out switch 213) when the tilt angle of the tower 34 reaches or exceeds a preset value. In this case, it is possible to prevent the locked state of the locked members 3, 103, 203 from being unintentionally released and the jib 35 from being forcefully swung out when the tower 34 has not reached the preset angle. [Explanation of symbols]

[0188] 1,101,201 Jib mooring device 2,102,202 Locking device 3,103,203 Locked member 4,104,204 Detection Device 5. Hydraulic pump 6. Directional valve (switching device) 7 Controller 8. Pressure Regulating Valve 9 Unlock switch (output device) 11 Latch (retaining member) 12 Unlocking member 13. Pressing member (tensile member) 14 Rope 15 Support bracket 16 Winch 17 Hydraulic motor (motor) 18 Limit Switch 19 Rotating lever 20 Spring 21 Locking lamp 22 Unlocked Lamp 25 Jib side bracket 30 Tower Crane 31 Undercarriage 32 Upper rotating body 33 Cab 34 Tower (Boom) 35 Jib 36 Gantry 37 Strut 38 Lower spreader 39 Counterweight 40 Backstop Device 41 Jib Point Sheave 44 Jib guy line 45 Lower spreader for jib hoisting 46 Strut guyline 47 Jib hoisting upper spreader 48 Jib Hoisting Rope 49 Boom Guyline 50 Upper Spreader 51 Boom hoisting rope 52 Boom foot pin 61 Lock pin (locking member) 62 Unlocking member 63 Pressing member 65 Support bracket 66 Tower side bracket 67 Rock Frame 68 Pin block member 69 Connecting members 70 Spring (connecting member, biasing member, tension member) 71 Connecting member support bracket 72 Connecting pin 75 Axis support bracket 76 Jib side bracket 77 First limit switch 78 Second limit switch 79 Stopper 81 Hook (retaining member) 82 Unlocking member 83 Pressing member (tensile member) 84 Bracket 85 Angle Detector 86 Rotating lever 87 Spring 88 Engagement member 88a Engagement part 89 Transportation 91 Guide member 92 Link member (rotation limiting means) 93 Moving parts 94 pin 210 Drive mechanism 211 Directional valve 212 Jib pull switch 213 Jib swing switch (output device)

Claims

[Claim 1] A jib mooring device for a crane in which a jib is attached to the tip of a boom so as to be able to be raised and lowered, A locking device provided on the boom; A locked member provided on the jib and locked by the locking device when the jib is folded relative to the boom; having The locking device comprises: a locking member movable between a locking position where the locked member is locked and a release position where the locked member is released from the locking position; an unlocking member connected to the locking member and movable between a locking position at which the locking member is positioned at the locking position and an unlocking position at which the locking member is positioned at the unlocked position; a biasing member that biases the unlocking member toward the locking position; A winch provided at the base of the boom or on the crane body; A rope that is unwound from the winch and connected to the lock release member; A motor for operating the winch; a tensioning member that pulls the rope in a direction in which the rope is paid out from the winch; having When the winch is powered by the motor, the winch is operated in one direction, the rope is wound on the winch, and the unlocking member moves to the unlocking position; A jib mooring device characterized in that, when power is not supplied from the motor, the winch is operated in the other direction opposite to the one direction by the pulling force of the tensioning member, so that the rope is unwound from the winch and the lock release member can be moved to the locked position.

Images