JP6642203B2 - crane - Google Patents

Description

  The present invention relates to a crane provided with a boom pivotally supported.

  2. Description of the Related Art Conventionally, a mobile crane including a crane body and a boom is known. The boom is pivotally attached to the front of the crane body.

  Patent Document 1 discloses a crane provided with such a boom. The boom includes a plurality of structures and includes a lower boom that is pivotally supported by the crane body. A long boom is formed by connecting a plurality of intermediate booms to the lower boom.

JP 2007-284167 A

  In the above-described crane, the crane may be stored in a state where only the lower boom is attached to the crane body. In this case, if the posture of the lower boom is set along the ground, the storage space for the crane is increased. Therefore, it is desirable that the lower boom be erected. At this time, when the lower boom, which is lighter than the entire boom, is greatly erected, there is a problem that the lower boom cannot fall down due to friction of the shaft support when the operation is resumed.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a crane in which storage preparation during assembly and disassembly can be easily realized and a storage space can be reduced.

  A crane according to one aspect of the present invention includes a crane body including a pivot, a boom including a lower boom rotatably supported by the pivot of the crane body, and a boom hoist connected to the boom. A rope, a boom hoisting winch for raising and lowering the boom by winding the boom hoisting rope, and a drive control unit for controlling the boom hoisting winch. In a state in which the boom is mounted on the crane main body, only a part of the boom including the lower boom is mounted on the crane main body, and an operation mode of raising and lowering the boom in a range equal to or less than a first preset ground angle. In the state, the boom is set to be smaller than the first ground angle in advance, and when the boom hoisting rope is extended, a part of the boom becomes its own weight. Parking part that raises and lowers a part of the boom within a range equal to or less than a second ground angle at which the boom can start to fall, and prohibits a part of the boom from ground angle exceeding the second ground angle. And a mode.

  According to this configuration, the drive control unit of the crane includes the work mode and the parking mode. In the work mode, the boom rises and falls in a range equal to or less than a preset first ground angle. On the other hand, in the parking mode, a part of the boom including the lower boom rises and falls in a range equal to or smaller than a second ground angle smaller than the first ground angle. Therefore, it is possible to prevent a part of the boom from being excessively raised in the parking mode. Further, when the boom hoisting rope is extended, a part of the boom can start to fall down by its own weight, and the crane can be stably stored even during the assembling or disassembling operation.

  The above configuration further includes a safety device that prohibits the boom or a part of the boom from being raised or lowered when a predetermined condition is satisfied during the execution of the work mode and the parking mode. The controller further includes, in addition to the work mode and the parking mode, an assembling / disassembling mode that enables the boom to be assembled and disassembled with respect to the crane body, and controls the safety device in the assembling / disassembling mode to control the boom. It is desirable to remove the restriction on the undulating operation of the vehicle.

  According to this configuration, the assembly and disassembly mode is executed during the disassembly and assembly work of the crane. At this time, since the restriction of the boom raising / lowering operation by the safety device is released, the boom raising / lowering different from the operation mode is enabled. On the other hand, in the work mode and the parking mode, since the raising and lowering operation of the boom by the safety device is restricted, it is suppressed that the worker needs to release the restriction of the safety device when shifting to the parking mode.

  The said structure WHEREIN: The tension detection part which detects the tension of the said boom raising / lowering rope, and the angle detection part which detects the ground angle of the said boom are further provided, The said drive control part is the said tension detection part and the said It is desirable that it is determined that only a part of the boom is mounted on the crane body based on the detection result of the angle detection unit, and the operation mode is shifted to the parking mode.

  According to this configuration, it is possible to shift to the parking mode based on the detection results of the tension detecting unit and the angle detecting unit during the crane storage operation.

  In the above configuration, a storage unit that stores an upper limit value of the tension of the boom hoisting rope that is set in advance according to a part of the boom with respect to a ground angle, and the storage unit that stores the upper limit value according to a detection result of the angle detection unit. And an output unit that outputs an upper limit value of the tension corresponding to the ground angle of a part of the boom from the unit, wherein the drive control unit outputs the tension detected by the tension detection unit. It is desirable to shift from the work mode to the parking mode when the difference is equal to or less than the set upper limit.

  According to this configuration, when the tension detected by the tension detection unit is equal to or less than the output upper limit value, it is determined that only a part of the boom is mounted on the crane body, and the shift to the parking mode is performed. can do.

  In the above-described configuration, it is preferable that an operation unit including a mode switch is further provided, and the drive control unit shifts from the work mode to the parking mode according to a switching operation of the mode switch.

  According to this configuration, when the crane is stored, it is possible to shift to the parking mode only by the operator operating the mode changeover switch.

  In the above configuration, a jib rotatably supported at the tip of the boom, and a jib up / down unit that raises and lowers the jib by rotating the jib, further comprising: a drive control unit. In the parking mode, it is desirable that the jib up / down unit restrict the up / down of the jib.

  According to this configuration, even when the crane includes the jib, it is possible to prevent the jib hoisting unit from being operated erroneously when shifting to the parking mode.

  ADVANTAGE OF THE INVENTION According to this invention, while providing for storage during assembling and disassembly is easily realized, the crane whose storage space can be reduced is provided.

It is a side view of the crane concerning one embodiment of the present invention. It is an electric block diagram of a crane concerning one embodiment of the present invention. It is a side view showing signs that a part of boom including a lower boom was attached to a crane main part in a crane concerning one embodiment of the present invention. FIG. 5 is a side view showing a crane according to an embodiment of the present invention, in which a part of a boom including a lower boom is erected. It is a flow chart of mode switching in the crane concerning one embodiment of the present invention. It is a flow chart of mode change in a crane concerning a modification of the present invention. It is a side view of a crane concerning a modification of the present invention. It is a side view of a crane concerning a modification of the present invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a crane 1 according to one embodiment of the present invention. In the following, directions of “up”, “down”, “front” and “rear” are shown in each figure, and the directions are used to describe the structure and assembling method of the crane 1 according to the present invention. It is shown for the sake of convenience, and does not limit the moving direction, usage mode, and the like of the crane 1.

  The crane 1 includes a revolving body 10 corresponding to a crane main body, a traveling body 11 that rotatably supports the revolving body 10 and can travel on the ground, a boom 13 as an up / down member, a boom up / down unit 13P, Is provided. A cab 12 is provided at the front end of the revolving superstructure 10. The cab 12 corresponds to the driver's seat of the crane 1. The cab 12 is provided with an operation unit 60 (FIG. 2) described later. In the vicinity of the cab 12, a shaft support (not shown) that supports the boom 13 is provided.

  The boom 13 shown in FIG. 1 is a so-called lattice type, and includes a lower boom 13A, one or a plurality of (one in the illustrated example) intermediate booms 13B, and a boom tip portion 13C. Specifically, the lower boom 13A is connected to a shaft support provided at the front part of the revolving unit 10 so as to be rotatable in the up-and-down direction. The intermediate boom 13B is detachably attached to the distal end side of the lower boom 13A. The boom tip 13C is detachably attached to the tip of the intermediate boom 13B. The boom 13 is rotatably supported (supported) by a pivot portion of the revolving body 10 around a boom foot 13S provided at a lower end portion of the lower boom 13A. Further, a first sheave 131 and a second sheave 132 are provided on the rear side of the lower boom 13A and the front end side of the boom tip portion 13C. A rope is hung on the first sheave 131 and the second sheave 132 as described later. In the present invention, the specific structure of the boom is not limited to the above. For example, the number of intermediate booms 13B of the boom may be different from the above. Further, the intermediate boom 13B may not be provided, and the boom tip 13C may be directly connected to the lower boom 13A.

  The boom raising / lowering unit 13P raises / lowers the boom 13 by rotating the boom 13 around the pivotal support of the revolving unit 10. The boom hoisting unit 13P includes a gantry 14, a boom hoisting winch 16, and a boom hoisting rope 17.

  The gantry 14 is a column that stands upright and rearward from a substantially central portion of the swing body 10. A gantry sheave 141 is provided at the tip of the gantry 14. Further, in order to prevent the gantry 14 from falling down, the distal end of the gantry 14 and the rear end of the revolving unit 10 are connected by a guy link 15. The guy links 15 are arranged as a pair in the left-right direction orthogonal to the paper surface of FIG. The guy link 15 is made of a metal wire or a rope.

  The boom hoisting rope 17 is connected to the lower boom 13A. More specifically, the boom hoisting rope 17 is pulled out from the boom hoisting winch 16 and is looped a plurality of times between the gantry sheave 141 of the gantry 14 and the first sheave 131 arranged on the distal end side of the lower boom 13A. . The tip of the boom hoisting rope 17 after being looped around the gantry sheave 141 and the first sheave 131 is fixed to the tip of the gantry 14.

  The boom hoisting winch 16 is arranged behind the base end of the gantry 14 in the revolving unit 10. The boom hoisting winch 16 raises and lowers the boom 13 by rotating and moving the boom 13 relative to the gantry 14 by winding and unwinding the boom hoisting rope 17. In particular, the boom hoisting winch 16 winds up the boom hoisting rope 17 to raise the boom 13 around the pivot portion of the revolving unit 10, and pulls out the boom hoisting rope 17, thereby causing the boom 13 to move by its own weight. Fall around.

  The crane 10 further includes a main winding winch 18 for hoisting and lowering the suspended load (the suspended body). In the crane 1 according to this embodiment, the main winding winch 18 is provided on the rear side of the cab 12 in the revolving unit 10. In another embodiment, the main winding winch 18 may be provided on the lower boom 13 </ b> A of the boom 13.

  The main winding winch 18 raises and lowers the suspended load by the main winding rope 19. A main hook (not shown) for hanging loads is provided at the tip (rope tip 19A) of the main winding rope 19 pulled out from the main winding winch 18. Then, the main winding rope 19 is stretched between the second sheave 132 at the tip of the boom 13 and a sheave of a sheave block (not shown) provided on the main hook. Accordingly, when the main winding winch 18 winds or unwinds the main winding rope 19, the distance between the second sheave 132 and the sheave of the main hook changes, and the tip of the rope hung from the tip of the boom 13 changes. The main hook connected to the portion 19A is raised and lowered. In the same manner, the crane 1 may be provided with an auxiliary winch (not shown), and the hoist rope may be used to hoist and lower the suspended load.

  Further, with reference to FIG. 1, the crane 1 includes a tension detecting unit 20 and an angle detecting unit 21. The tension detector 20 is disposed near the first sheave 131 on the distal end side of the lower boom 13A. The tension detector 20 detects the tension T of the boom hoisting rope 17. The angle detector 21 is arranged near the lower end (boom foot 13S) of the lower boom 13A. The angle detection unit 21 detects the ground angle θ of the boom 13 (the lower boom 13A) (the angle formed by a center line extending in the longitudinal direction of the boom 13 and a horizontal line).

  FIG. 2 is an electrical block diagram of the crane 1 according to the present embodiment. The crane 1 further includes a control unit 50, an operation unit 60, and a safety device 62.

  The control unit 50 controls the operation of the crane 1 as a whole. In addition to the tension detection unit 20, the angle detection unit 21, the operation unit 60, and the safety device 62, the control signal is sent and received, It is electrically connected to the winch 16, the main winding winch 18, the traveling body 11, and the like. The control unit 50 is also electrically connected to other units provided in the crane 1.

  The operation unit 60 is disposed inside the cab 12 (FIG. 1), and is operated by an operator of the crane 1. In the present embodiment, the operation unit 60 includes an operation lever (not shown) used for operating the boom hoisting winch 16 and the main winding winch 18. The operation unit 60 includes a switch 61. The switch 61 is used when the operator switches the work mode, as described later. The switch 61 functions as a mode switch of the present invention.

  The safety device 62 limits the up-and-down operation of the boom 13 when a predetermined condition is satisfied in a work mode and a parking mode described below. For this reason, the safety device 62 is electrically connected to the boom hoisting winch 16. As an example, the safety device 62 prohibits the operation of raising and lowering the boom 13 by the boom raising and lowering winch 16 when the load applied to the boom 13 exceeds a predetermined value.

  The control unit 50 includes a CPU (Central Processing Unit), a ROM (Read Only Memory) storing a control program, a RAM (Random Access Memory) used as a work area of the CPU, and the like, and the CPU executes the control program. By doing so, it operates to have the drive control unit 51, the output unit 52, the determination unit 53, and the storage unit 54 functionally.

  The drive control unit 51 controls the winding and unwinding of the boom hoisting winch 16 and the main winding winch 18 based on an operation of an operator who is on the cab 12. Further, the drive control unit 51 controls the traveling of the crane 1 by controlling the traveling body 11.

  The drive control unit 51 has a plurality of operation modes of the crane 1. In the present embodiment, the drive control unit 51 has a work mode, an assembly / disassembly mode, and a parking mode. The work mode is a mode in which the crane 1 is normally used. In the operation mode, in a state where the boom 13 is mounted on the revolving unit 10, the lifting operation of the suspended load by the main winding rope 19 hung from the distal end side of the boom 13 is allowed. The assembling / disassembling mode is a mode for assembling and disassembling the crane 1. As an example, the assembling and disassembling of the boom 13 with respect to the swing body 10 are enabled. Further, the parking mode is a mode for performing a predetermined storage preparation because the crane 1 is temporarily stored.

  The storage unit 54 stores in advance an upper limit value TL of the tension T of the boom hoisting rope 17 according to the ground angle θ of the lower boom 13A (part of the boom). In addition, the storage unit 54 stores first and second ground angles θ, which will be described later.

  The output unit 52 outputs the upper limit value TL of the tension of the boom hoisting rope 17 from the storage unit 54 according to the part of the boom 13 relative to the ground angle θ detected by the angle detection unit 21.

  The determination unit 53 functions as a part of the drive control unit 51, and determines that only the lower boom 13A is mounted on the swing body 10 based on the detection results of the tension detection unit 20 and the angle detection unit 21. In particular, when the tension T detected by the tension detection unit 20 is equal to or less than the upper limit value TL, the determination unit 53 determines that only the lower boom 13A is mounted on the swing body 10. In other words, the determination unit 53 determines that the entire boom 13 is not mounted on the swing body 10.

  FIG. 3 is a side view showing a state where the lower boom 13A is mounted on the crane main body in the crane 1 according to the present embodiment. FIG. 4 is a side view showing the crane 1 in a state where the lower boom 13A is erected.

  At the time of assembling the crane 1 as shown in FIG. 1, the lower boom 13A of the boom 13 is mounted on the revolving unit 10, as shown in FIG. Thereafter, the intermediate boom 13B and the boom tip 13C are sequentially connected to the lower boom 13A. Similarly, when the crane 1 is disassembled, the boom tip 13C and the intermediate boom 13B are sequentially removed while the boom 13 is pivotally supported by the revolving superstructure 10, so that the state shown in FIG. 3 is obtained. Thus, in a state where only the lower boom 13A is attached to the revolving unit 10, the assembling and disassembling work of the crane 1 may be interrupted, and the crane 1 may be stored.

  In this case, since the lower boom 13A protrudes forward from the swing body 10, the storage space of the crane 1 increases. For this reason, as shown in FIG. 4, it is desirable that the storage space of the crane 1 be reduced by raising the lower boom 13 </ b> A by winding up the boom hoisting winch 16. If only the lower boom 13A starts to be erected in the normal operation mode, a predetermined error occurs because a limit switch (not shown) for limiting overwinding of the main winding rope 19 has not been mounted yet, The operation of the crane 1 (boom hoisting winch 16) is automatically stopped. In this case, a release operation for stopping detection of the limit switch by the operator is required. Further, when the operation of restarting the detection of the limit switch is forgotten when the operation is resumed after the storage, there is a problem that the operation cannot be efficiently resumed.

  Further, when the lower boom 13A is erected after the detection of the limit switch is released, if the ground angle θ of the lower boom 13A becomes too large, when the assembly and disassembly work is restarted, the boom hoisting winch 16 is extended. Also, a problem that the lower boom 13A does not descend tends to occur. The lower boom 13A alone is lighter in weight than the case where the boom 13 as shown in FIG. For this reason, if the ground angle θ of the lower boom 13A is too large, the frictional force between the boom foot 13S and the pivot support of the revolving unit 10 is larger than the moving force due to the rotational moment of the lower boom 13A. 13A becomes difficult to descend. In this case, even if the boom hoisting winch 16 draws out the boom hoisting rope 17, the boom hoisting rope 17 is slackened, and the lower boom 13A does not easily fall. As an example, when the crane 1 as shown in FIG. 1 is used, the ground angle θ of the boom 13 is used in the range of 70 ° to 80 °. However, when the crane 1 shown in FIG. Angle θ is desirably set to 60 ° or less. For this reason, in order to raise the lower boom 13A when storing the crane 1, it is necessary for the operator to raise the boom hoisting winch 16 while carefully checking the ground angle θ of the lower boom 13A.

  In order to solve such a problem, in the present embodiment, the crane 1 includes the drive control unit 51. FIG. 5 is a flowchart of mode switching to the parking mode in the crane 1 according to the present embodiment. As described above, the drive control unit 51 has three modes: the work mode, the parking mode, and the disassembly mode. In the assembly and disassembly operation of the crane 1, a complicated operation of the crane 1 different from the normal operation mode is required. For this reason, it is desirable that the execution of the assembling / disassembling mode is started by the intention of an operator who has boarded the cab 12.

  In the operation mode, the drive control unit 51 allows the lifting operation of the suspended load by the main winding rope 19 and sets the upper limit value of the ground angle θ of the boom 13 to the first ground angle. As a result, the ups and downs of the boom 13 are performed in a range equal to or smaller than the first ground angle. In the present embodiment, the first ground angle is set to 80 ° in advance. On the other hand, in the parking mode in which only the lower boom 13A (part of the boom 13) is mounted on the revolving unit 10, the drive control unit 51 allows the lower boom 13A to undulate and sets the ground angle θ of the lower boom 13A to ground. Is set to a second ground angle smaller than the first ground angle. The second ground angle is an angle at which the lower boom 13A can start falling down by its own weight when the boom hoisting rope 17 is extended. In the present embodiment, the second ground angle θ is set to 60 ° in advance. In FIG. 5, the second ground angle θ is indicated as θL.

  In the normal state of the crane 1, the operation mode or the assembly / disassembly mode is executed. Referring to FIG. 5, when the storage preparation operation of crane 1 is started, drive control unit 51 checks whether or not the current mode is the operation mode (step S01 in FIG. 5). When the mode of the crane 1 is the assembling / disassembling mode (NO in step S01), since the assembling / disassembling work of the crane 1 is continued as it is, the shift to the parking mode by the drive control unit 51 is not executed. (END).

  On the other hand, when the crane 1 is in the work mode (YES in step S01 in FIG. 5), the angle detector 21 detects the ground angle θ of the boom 13 (the lower boom 13A) (step S02). At this stage, the drive control unit 51 does not recognize whether the entire boom 13 is mounted on the swing body 10 or only the lower boom 13A is mounted. Thereafter, the output unit 52 (FIG. 2) outputs the upper limit value TL of the tension of the boom hoisting rope 17 from the storage unit 54 according to the ground angle θ detected by the angle detection unit 21 (Step S03). Next, the determination unit 53 compares the tension T of the boom hoisting rope 17 detected by the tension detection unit 20 with the upper limit value TL output by the output unit 52 (Step S04).

  When the tension T of the boom hoisting rope 17 detected by the tension detecting unit 20 is equal to or less than the upper limit value TL, the determination unit 53 determines that only the lower boom 13A is mounted on the revolving unit 10 (Step S04). YES). As a result, the drive control unit 51 shifts from the work mode to the parking mode (step S05). In the parking mode, the operation of the main winch 18 is restricted for safety, and the winding and unwinding operation of the boom hoisting winch 16 and the traveling of the traveling body 11 are allowed.

  On the other hand, when the tension T of the boom hoisting rope 17 detected by the tension detecting unit 20 is larger than the upper limit value TL, the determining unit 53 determines that the entire boom 13 is mounted on the revolving unit 10 (step). (NO in S04). In this case, the drive control unit 51 does not allow the shift from the work mode to the parking mode, and ends the mode shift control (END).

  When the drive control unit 51 shifts from the work mode to the parking mode (step S05), the worker or the drive control unit 51 winds the boom hoisting winch 16 and raises the lower boom 13A. At this time, the determination unit 53 compares the ground angle θ detected by the angle detection unit 21 with the second ground angle θL stored in the storage unit 54 in advance (Step S06). When the ground angle θ detected by the angle detecting unit 21 is equal to or larger than the second ground angle θL (YES in step S06), the drive control unit 51 stops the winding of the boom hoisting winch 16 and raises the lower boom 13A. Is limited (stopped) (step S07).

  As described above, in the present embodiment, the drive control unit 51 of the crane 1 has the work mode and the parking mode. In the operation mode, the operation of lifting the suspended load by the main winding rope 19 can be performed. At this time, the ground angle θ of the boom 13 is allowed up to the first ground angle. On the other hand, in the parking mode, the ground angle θ of the lower boom 13A is set to a second ground angle smaller than the first ground angle. For this reason, it is suppressed that the lower boom 13A is excessively erected in the parking mode. As a result, after the crane 1 is stored, the lower boom 13A can easily fall down when work is resumed. Accordingly, the crane 1 is provided, in which the storage preparation during the assembly and disassembly can be easily realized and the storage space can be reduced.

  Further, in this embodiment, at the time of disassembling and assembling the crane, the drive control unit 51 executes the assembling and disassembling mode according to an input instruction from an operator. At this time, since the restriction of the raising and lowering operation of the boom 13 by the safety device 62 is released, it is possible to raise and lower the boom different from the normal operation mode. On the other hand, in the work mode and the parking mode, since the raising and lowering operation of the boom 13 by the safety device 62 is continuously restricted, the worker needs to release the restriction of the safety device 62 when shifting from the work mode to the parking mode. Is suppressed.

  Furthermore, in the present embodiment, when the crane 1 is stored, it is determined that only the lower boom 13A is mounted on the revolving unit 10 based on the detection results of the tension detecting unit 20 and the angle detecting unit 21. Can be migrated to. Therefore, compared to the case where the lower boom 13A is erected based on the experience and feeling of the worker, the storage preparation of the crane 1 is executed safely and efficiently. In the parking mode, the drive control unit 51 allows the running of the traveling body 11 and the turning of the revolving body 10 in addition to the winding and unwinding of the boom hoisting winch 16. Therefore, after shifting to the parking mode, the revolving unit 10 can be moved and swung for storing the crane 1.

  The crane 1 according to each embodiment of the present invention has been described above. Note that the present invention is not limited to these embodiments. The crane according to the present invention may be any crane provided with a predetermined crane main body and a boom. Further, in the present invention, the following modified embodiments are possible.

  (1) In the above embodiment, only the lower boom 13A is mounted on the revolving unit 10 as a part of the boom 13 when the crane 1 is stored, but the present invention is not limited to this. Absent. When the crane 1 is stored, only the lower boom 13A and the intermediate boom 13B may be mounted on the revolving unit 10 as a part of the boom 13. Further, in the above embodiment, the boom hoisting rope 17 has been described as being connected to the lower boom 13A regardless of whether the crane 1 is operated or stored. It is not limited. In another embodiment, the boom hoisting rope 17 may be connected to the distal end side of the lower boom 13A of the boom 13 during the operation of the claim 1. In this case, when storing the claim 1, the boom hoisting rope 17 may be removed from the tip end side of the boom 13 and attached to the lower boom 13A. A connection attachment such as a spreader and a guy link (not shown) may be attached to the boom hoisting rope 17, and the connection attachment may be connected to the boom 13 (the lower boom 13A).

  (2) In the above embodiment, the three modes of the operation mode, the parking mode, and the disassembly mode have been described as the modes executed by the drive control unit 51. However, the present invention is not limited to this. Absent. The drive control unit 51 may execute two modes of a work mode and a parking mode. In this case, in the flowchart of FIG. 5, step S02 may be started without executing step S01.

  (3) In the above-described embodiment, the mode in which the mode is shifted from the work mode to the parking mode based on the detection results of the tension detecting unit 20 and the angle detecting unit 21 has been described. However, the present invention is not limited to this. Not something. FIG. 6 is a flowchart of mode switching in the crane according to the modified embodiment of the present invention. In the present modified embodiment, when the worker turns on the switch 61 (parking mode switch) of the operation unit 60 in step S11, the drive control unit 51 shifts from the work mode to the parking mode (step S12). Thereafter, steps S13 and S14 in FIG. 6 are the same as steps S06 and S07 in FIG. 5 according to the previous embodiment. According to such a configuration, since the drive control unit 51 shifts from the work mode to the parking mode according to the switching operation of the switch 61, the mode can be quickly switched according to the intention of the worker.

  (4) In the above embodiment, the structure of the crane 1 shown in FIG. 1 has been described, but the present invention is not limited to this. 7 and 8 are side views of the cranes 1A and 1B according to a modified embodiment of the present invention. The crane 1A shown in FIG. 7 is different from the crane 1 (FIG. 1) according to the previous embodiment in that a first mast 71, a second mast 72, a mast hoisting rope 73, a guy link 74, and a guy link 75 are provided. It is different in that it is prepared. The first mast 71 and the second mast 72 are rotatably supported by the revolving superstructure 10 behind the boom 13. The distal end of the first mast 71 and the distal end of the second mast 72 are connected by a guy link 74. Further, the mast hoisting rope 73 is looped around the rear end of the revolving unit 10 and the front end of the first mast 71 a plurality of times. When the boom hoisting winch 16 winds and unwinds the mast hoisting rope 73, the first mast 71 and the second mast 72 rotate integrally with the revolving unit 10. As a result, the boom 13 connected to the guy link 75 extended from the distal end of the second mast 72 rotates and undulates. Also in such a configuration, the lower boom 13A is erected by the winding operation of the boom hoisting winch 16 with only the lower boom 13A (part of the boom 13) mounted on the revolving unit 10. At this time, the drive control unit 51 (FIG. 2) executes the parking mode according to the present invention, so that the crane 1A can be efficiently prepared for storage.

  The crane 1B shown in FIG. 8 has a jib 80, a rear strut 81, a front strut 82, a guy link 83, a jib hoisting winch 84, a jib, as compared with the crane 1 (FIG. 1) according to the previous embodiment. The difference is that an undulating rope 85 is provided. The jib 80 is rotatably supported at the tip of the boom 13. The rear strut 81 and the front strut 82 are rotatably supported by the tip of the boom 13 behind the jib 80. Note that the rear strut 81 and the front strut 82 may be pivotally supported at the base end of the jib 80. Further, the rear strut 81 may be supported by the boom 13, and the front strut 82 may be supported by the jib 80. The distal end of the jib 80 and the distal end of the front strut 82 are connected by a guy link 83. Further, the jib hoisting rope 85 pulled out from the jib hoisting winch 84 is wound around the tip of the rear strut 81 and the tip of the front strut 82 a plurality of times. When the jib hoisting winch 84 winds and unwinds the jib hoisting rope 85, the front strut 82 and the jib 80 rotate integrally with the rear strut 81 as a support. As a result, the jib 80 rotates and undulates. Also in such a configuration, the lower boom 13A is erected by the winding operation of the boom hoisting winch 16 with only the lower boom 13A (part of the boom 13) mounted on the revolving unit 10. At this time, the drive control unit 51 (FIG. 2) executes the parking mode according to the present invention, so that the storage preparation of the crane 1B can be efficiently executed. The rear strut 81, the front strut 82, the guy link 83, the jib hoisting winch 84, and the jib hoisting rope 85 constitute the jib hoisting unit 80P of the present invention. The jib up / down unit 80P has a function of turning up and down the jib 80 by rotating the jib 80. In the present modified embodiment, it is desirable that the drive control unit 51 (FIG. 2) controls the jib hoisting winch 84 of the jib hoisting unit 80 </ b> P in the parking mode to limit (prohibit) the hoisting of the jib 80. In this case, even when the crane 1 is provided with the jib hoisting winch 84, the jib hoisting winch 84 is prevented from being erroneously operated at the time of shifting to the parking mode.

1,1A, 1B Crane 10 Revolving body (crane body)
DESCRIPTION OF SYMBOLS 11 Running body 12 Cab 13 Boom 13A Lower boom 13B Intermediate boom 13C Boom tip 13P Boom raising / lowering unit 14 Gantry 15 Guy link 16 Boom raising / lowering winch 17 Boom raising / lowering rope 18 Main winding winch 19 Main winding rope 20 Tension detector 21 Angle detection unit 50 Control unit 51 Drive control unit 52 Output unit 53 Judgment unit 54 Storage unit 60 Operation unit 61 Switch (mode switch)
62 Safety device 80 Jib 80P Jib hoisting unit

Claims (6)

A crane body having a shaft support,
A boom including a lower boom rotatably supported by the pivot portion of the crane body;
A boom hoisting rope connected to the boom,
A boom hoisting winch for hoisting the boom by winding the boom hoisting rope;
A drive control unit for controlling the boom hoisting winch,
A tension detector for detecting the tension of the boom hoisting rope,
An angle detection unit that detects a ground angle of the boom,
With
The drive control unit includes:
An operation mode for raising and lowering the boom in a range equal to or less than a preset first ground angle in a state where the boom is mounted on the crane body;
When only a part of the boom including the lower boom is mounted on the crane main body, the boom is set to be smaller than the first ground angle in advance, and the boom hoisting rope is extended. Part of the boom is raised and lowered in a range not more than a second ground angle at which a part of the boom can start falling down by its own weight, and the ground angle of a part of the boom exceeds the second ground angle. Parking mode to be prohibited, and it is determined that only a part of the boom is mounted on the crane body based on the detection results of the tension detecting unit and the angle detecting unit. crane, characterized that you migrate to the machine mode. When a predetermined condition is satisfied during the execution of the work mode and the parking mode, further includes a safety device that prohibits the boom or a part of the boom from undulating.
The drive control unit further includes, in addition to the work mode and the parking mode, an assembling / disassembling mode that enables assembly and disassembly of the boom with respect to the crane body, and controls the safety device in the assembling / disassembling mode. The crane according to claim 1, wherein the restriction on the boom raising / lowering operation is released. A storage unit that stores an upper limit value of the tension of the boom hoisting rope set in advance according to a part of the boom with respect to a ground angle,
An output unit that outputs an upper limit value of the tension corresponding to the ground angle of a part of the boom from the storage unit according to a detection result of the angle detection unit,
Further having
The method according to claim 1, wherein the drive control unit shifts from the work mode to the parking mode when the tension detected by the tension detection unit is equal to or less than the output upper limit value. 4 . The crane described. Further comprising an operation unit including a mode changeover switch,
The crane according to any one of claims 1 to 3, wherein the drive control unit shifts from the work mode to the parking mode according to a switching operation of the mode switch. A jib pivotally supported at the tip of the boom,
A jib undulation unit that raises and lowers the jib by rotating the jib,
Further having
The drive control section, at the stationed motor mode, the crane according to any one of claims 1 to 4, characterized in that prohibiting undulations of the jib by the jib pivoting unit.   A crane body having a shaft support,
  A boom including a lower boom rotatably supported by the shaft support of the crane body;
  A boom hoisting rope connected to the boom,
  A boom hoisting winch for hoisting the boom by winding the boom hoisting rope;
  A drive control unit for controlling the boom hoisting winch,
  A jib pivotally supported at the tip of the boom,
  A jib undulation unit that raises and lowers the jib by rotating the jib,
  With
  The drive control unit includes:
    An operation mode for raising and lowering the boom in a range equal to or less than a preset first ground angle in a state where the boom is mounted on the crane body;
    When only a part of the boom including the lower boom is mounted on the crane main body, the boom is set to be smaller than the first ground angle in advance, and the boom hoisting rope is extended. Part of the boom is raised and lowered in a range not more than a second ground angle at which a part of the boom can start falling down by its own weight, and the ground angle of a part of the boom exceeds the second ground angle. A crane mode, wherein the jib up / down unit prohibits the jib up / down movement in the park mode.

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