JP2020001883A - Crane and posture change method of crane - Google Patents

Abstract

To provide a crane comprising a lifting body comprising a boom and a gib, capable of preventing overturn of a crane and reducing a load applied to an operator in erecting work, when erecting the lifting body from the ground by releasing a moment limiter function.SOLUTION: A crane 1 comprises an upper turning body 4, a boom 16, a gib 18, and an operation regulation part 703. The operation regulation part 703 can be switched between a normal work mode and a self-supporting permission mode of the crane 1. The operation regulation part 703 regulates a lifting operation of the boom 16 and erecting operation of the gib 18 when a contact determination condition for determining a normal contact to the ground surface of a tip part of the gib 18 is not satisfied, in a state in which a gib offset angle θm which is defined by an extension line of a center line of the boom 16 and a center line of the gib 18 is smaller than an offset limit angle θs formed of a preset acute angle.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a crane and a method for changing a posture of the crane.

  2. Description of the Related Art Conventionally, there is known a crane including a boom provided on a crane body so as to be able to undulate, and a jib connected to the tip of the boom so as to be able to undulate. The crane includes a boom hoisting winch that winds and unwinds a boom hoisting rope connected to a boom tip, and a jib hoist that winds and unwinds a jib hoisting rope connected to a jib tip. A winch. In addition, the crane includes a lifting rope suspended from a distal end of the jib, and a hook connected to the distal end of the lifting rope. By lifting and unwinding the lifting rope, it is possible to lift and suspend a suspended load connected to the hook.

  The crane is in a posture (working posture) in which the boom extends upward and forward from the upper swing body and the jib extends further upward and forward in order to perform a normal operation. On the other hand, Patent Literature 1 discloses, as a posture for disassembling or assembling such a crane, an overhanging posture in which the boom is laid down on the crane main body and the jib projects from the boom along the ground, An inner holding posture is disclosed in which the boom folds down with respect to the boom so that the boom lays down and the jib approaches the lower surface of the boom in the laid down state.

JP 2008-239327 A

  In order for the above-mentioned crane to work safely in the working posture, a work allowable range (work allowable radius) is set according to the weight of the suspended load. Then, in order to prevent the crane from tipping over due to the moment acting on the crane body due to the load of the suspended load, the rotation of the boom and the jib is restricted when the tip of the jib is out of the allowable working range during the work ( Moment limiter function). On the other hand, in order to change the posture of such a crane from the overhanging posture or the holding posture to the working posture, it is necessary to raise the boom and the jib arranged in an area exceeding the allowable working range from the ground. Therefore, when the boom and jib are raised, the above-described moment limiter function must be released. However, when raising the boom and the jib in a state where the moment limiter function is released, depending on the posture of the crane, the crane body may not be able to support the boom and the jib, and the crane may fall forward. Therefore, it is necessary for the worker to perform the boom and jib erecting work while paying attention to the falling of the crane. As a result, there is a problem that much time and operator's attention are required to change the posture of the crane from the lying posture to the working posture.

  An object of the present invention is to provide a crane provided with an up-and-down body including a boom and a jib connected to a tip end of the boom, when the crane is overturned when the moment limiter function is released and the up-and-down body is raised from the ground. And to reduce the burden on the worker in the erecting operation.

  As described above, the boom and the jib can be raised from the ground by releasing the moment limiter function that functions during the normal operation of the crane. However, even when standing up, it is necessary to consider the safety of the crane. The inventor of the present invention pays attention to a jib offset angle which is an angle formed between the boom and the jib when standing up, and if the jib offset angle satisfies a predetermined condition, even when the moment limiter function is released, It was found that the crane can change its posture from the lying posture to the working posture without falling down.

  From such a viewpoint, provided by the present invention is a crane, which is a crane, a crane main body, and a boom rotatably supported around a first rotation axis horizontal to the crane main body, A jib having a base end rotatably supported at a tip end of the boom about a second rotation axis parallel to the first rotation axis and a tip end opposite to the base end; A boom drive for rotating the jib about the second rotation axis in the rising and falling directions, a jib drive for rotating the jib about the second rotation axis in the rising and falling directions, the boom and the jib An operation unit that receives an operation for driving the drive unit, a drive control unit that outputs a drive signal that controls the boom drive unit and the jib drive unit according to the operation input to the operation unit, The jib An operation unit that receives an operation for driving, a suspension device that is suspended from a tip end of the jib and connected to a suspended load, and an operation that regulates rotation of the boom and the jib according to a preset mode. A restricting unit, wherein the operation restricting unit has a normal operation mode and a self-supporting permissible mode, and in the normal operation mode, the boom stands up with respect to the crane body and the jib moves with respect to the boom. In the standing posture of the crane, the rotation of the boom and the jib is regulated so that the tip end of the jib is included in a work allowable range set according to the load of the suspended load. , Regardless of the load of the suspended load, allows the tip of the jib to enter outside of the work allowable range, and the boom and the jib are in the work posture. An operation restricting portion that allows the crane to change its posture from the falling posture in which the tip of the jib lands forward on the ground and the tip portion of the jib lands on the ground, to the working posture, and the state of the jib, A jib contact state determination unit that determines whether a predetermined contact determination condition is satisfied to determine whether the tip end of the jib is normally in contact, and a jib contact state determination unit that is parallel to the second rotation axis. A jib boom angle condition that is satisfied when a jib offset angle that is an angle defined by an extension of the center line of the boom and the center line of the jib when viewed from the direction is larger than a threshold angle including a preset acute angle. An angle condition determining unit for determining whether the jib boom angle condition is not satisfied by the angle condition determining unit in the self-sustained permission mode. When the jib is in the upright direction and the downturn direction, and only when the jib contact state determination unit determines that the jib state satisfies the contact determination condition, the jib is upright and down. If the jib contact state determination unit determines that the jib state does not satisfy the contact determination condition while allowing the jib to rotate in the falling direction, the jib is allowed to rotate in the falling direction and the drive is performed. When the boom angle condition is determined to be satisfied by the angle condition determination unit, restricting the rotation of the boom in the rising direction and the falling direction and the rotation of the jib in the rising direction regardless of the signal. Regardless of the determination result by the jib contact state determination unit, the rotation of the boom in the rising direction and the falling direction and the rotation of the jib in the rising direction and the falling direction are described. To capacity.

  According to this configuration, the operation restricting unit that restricts the rotation of the jib and the boom has the normal work mode and the self-sustaining mode. In the normal operation mode, the operation restricting unit restricts the rotation of the boom and the jib so that the tip of the jib is included in the allowable operation range set in accordance with the load of the suspended load (moment limiter function). For this reason, the lifting work of the suspended load can be performed safely. On the other hand, in the self-sustaining mode, the operation restricting unit allows the crane to change the posture from the lying posture to the working posture. Then, the operation restricting unit determines that the jib boom angle condition is not satisfied during the execution of the self-sustaining mode and the state of the jib is the contact determination condition, that is, that the jib is normally in contact with the ground. When the jib contact state determination unit determines that the condition for determination is not satisfied, the boom up / down operation and the jib upright operation are regulated. On the other hand, when the jib boom angle condition is satisfied, or when the jib contact state determination unit determines that the contact determination condition is satisfied, the movement restricting unit performs the boom up / down operation and the jib up / down operation. Tolerate. For this reason, it is prevented that the state in which the tip of the jib is lifted off the ground is continued in a state where the opening angle between the boom and the jib (the outer angle when the jib offset angle is an inner angle) is large. As a result, it is possible to safely change the posture of the crane in the state in which the moment limiter function is released from the falling posture to the working posture while preventing the crane from tipping over. Further, in the self-sustaining work, it is possible to reduce the burden on the worker of paying attention to the falling of the crane.

  Here, the “contact determination condition predetermined to determine whether the tip of the jib is normally in contact with the ground” refers to the condition in which the tip of the jib actually contacts the ground. Or a condition for determining that the tip of the jib is lifted from the ground against the weight of the jib, etc. A condition in which the contact pressure is significantly reduced may be a condition in which such a condition is excluded from “normal contact” because it is not normal contact. For example, in the above configuration, the apparatus further includes a tension detector that detects the tension of the jib hoisting rope, wherein the jib contact state determination unit is configured such that the tension detected by the tension detector is equal to or less than a preset threshold tension. In this case, it may be determined that the contact determination condition is satisfied.

  According to this configuration, by using the magnitude of the tension of the jib hoisting rope, it is detected whether or not the tip end of the jib is actually rising from the ground or whether or not there is a possibility of rising. Can be.

  In the above configuration, an operator's cab arranged on the crane main body, which allows an operator operating the crane to board, and a display unit arranged in the operator's cab and displaying predetermined work information, The operation restricting unit includes: in the self-sustaining mode, the angle condition determination unit determines that the jib boom angle condition is not satisfied, and the jib contact state determination unit determines that the jib state is the contact determination condition. If it is determined that the condition is not satisfied, it is desirable to output a signal for displaying predetermined warning information on the display unit.

  According to this configuration, if both the jib boom angle condition and the contact determination condition are not satisfied, the operation restricting unit outputs a signal for displaying warning information on the display unit. Therefore, it is possible to promptly notify the worker that the crane has approached a position where the crane is likely to fall. As a result, the crane can be prevented from falling down.

  In the above configuration, a boom angle detector for detecting a ground angle of the boom, a jib angle detector for detecting a ground angle of the jib, a ground angle of the boom detected by the boom angle detector, and the jib. An angle determination unit that determines the jib offset angle from the ground angle of the jib detected by an angle detection unit, and a storage unit that can store the threshold angle in advance and output the threshold angle, and It is preferable that the condition determination unit determines that the jib boom angle condition is satisfied when the jib offset angle determined by the angle determination unit is larger than the threshold angle output from the storage unit.

  According to this configuration, the jib offset angle can be determined from the detection results of the boom angle detection unit and the jib angle detection unit that are usually provided in the crane. As a result, it is possible to determine whether the jib boom angle condition is satisfied by using these detection units.

  In the above configuration, the apparatus further includes an input unit that receives length information on the length of the jib and the length of the boom, and the storage unit stores a combination of the length of the jib and the length of the boom. It is preferable that a plurality of threshold angles are stored, and a predetermined threshold angle is output from the plurality of threshold angles in accordance with the length information input to the input unit.

  According to this configuration, even if a jib or a boom having a different length is mounted on the crane main body and the crane easily changes its posture, the appropriate threshold angle can be acquired according to the length information.

  In the above configuration, the crane body further includes a weight body disposed behind the crane body or behind the crane body to maintain the balance of the crane, and the input unit is configured to provide weight information on a weight of the weight body. Furthermore, the storage unit stores a plurality of the threshold angles according to a combination of the length of the jib, the length of the boom, and the weight of the weight body, and inputs the threshold angles to the input unit. It is preferable that a predetermined threshold angle is output from the plurality of threshold angles according to the length information and the weight information obtained.

  According to this configuration, an appropriate threshold angle can be obtained in accordance with the weight information even when the weight body having a different weight is mounted on the crane main body or the back of the crane main body and the posture in which the crane easily falls down changes.

  Also provided by the present invention are a crane body, a boom rotatably supported about a first rotation axis horizontal to the crane body, and a tip end of the boom parallel to the first rotation axis. A jib having a base end rotatably supported around a second rotation axis and a tip end opposite to the base end; and an operation unit for receiving an operation for driving the boom and the jib. Wherein the rotation of the boom and the jib is regulated in accordance with a preset normal operation mode and a self-sustaining mode, and the boom is controlled in the normal operation mode. In the working posture of the crane in which the jib stands up with respect to the crane body and the jib stands up with respect to the boom, the tip end of the jib falls within a work allowable range set according to the load of the suspended load. Restricting the rotation of the boom and the jib so as to be rare, and in the self-supporting permissible mode, allowing the tip of the jib to enter outside the work permissible range regardless of the load of the suspended load, The boom and the jib fall forward from the working posture, and the crane is allowed to change its posture to the working posture from a lying posture in which a tip end of the jib lands on the ground, and in the self-sustaining permission mode, A jib offset angle, which is an angle defined by an extension of the center line of the boom and the center line of the jib as viewed from a direction parallel to the second rotation axis, is smaller than a preset threshold angle, and When the state of the jib does not satisfy a predetermined contact determination condition to determine that the tip of the jib is normally in contact with the ground, The jib is allowed to rotate in the falling direction and the boom is restrained from rotating in the rising direction and the falling direction and the jib from rotating in the rising direction regardless of the operation received by the operation unit, and In the allowable mode, if at least the jib offset angle is larger than the threshold angle or the state of the jib satisfies the contact determination condition, the boom is turned in the upright and down directions and the jib is raised. Changing the posture of the crane from the lying posture to the working posture while permitting rotation in the moving direction and the falling direction.

  According to the method, the lifting operation of the suspended load can be safely performed in the normal operation mode. On the other hand, in the self-sustaining mode, when the crane is changed from the lying position to the working position, the boom or jib is moved while the angle between the boom and the jib is large and the jib tip is lifted off the ground. There is no. For this reason, the crane in the state in which the moment limiter function is released can be safely changed from the lying posture to the working posture while preventing the crane from falling forward.

  As described above, according to the present invention, in a crane provided with an up-and-down body including a boom and a jib connected to a tip end of the boom, when the moment limiter function is released to raise the up-and-down body from the ground, In addition, it is possible to prevent the crane from overturning and to reduce the burden on the worker in the independent operation.

It is a schematic side view of the 1st form of the crane concerning one embodiment of the present invention. It is a schematic side view of the 2nd form of the crane concerning one embodiment of the present invention. It is an electric block diagram of the composition which controls the crane concerning one embodiment of the present invention. FIG. 4 is a schematic diagram illustrating each mode of the operation restricting unit of FIG. 3. It is a flowchart which shows the process for the crane which concerns on one Embodiment of this invention to change to an independent disassembly mode from an assembly disassembly mode. It is a flowchart which shows the process in the self-standing fall mode of the crane which concerns on one Embodiment of this invention. It is a flowchart which shows the process in the self-standing fall mode of the crane which concerns on one Embodiment of this invention. It is a flowchart showing the self-standing fall operation of the crane concerning one embodiment of the present invention. It is a flowchart showing the self-standing fall operation of the crane concerning one embodiment of the present invention. It is a flowchart showing the self-standing fall operation of the crane concerning one embodiment of the present invention. It is a flowchart showing the self-standing fall operation of the crane concerning one embodiment of the present invention. It is a flowchart showing the self-standing fall operation of the crane concerning one embodiment of the present invention. It is a flowchart showing the self-standing fall operation of the crane concerning one embodiment of the present invention. It is a flowchart showing the self-standing fall operation of the crane concerning one embodiment of the present invention.

  Hereinafter, a crane 1 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic side view of a first embodiment (a crane 1A) of a crane 1 according to the present embodiment. The first mode is also called an STD-LF mode (standard luffing mode). FIG. 2 is a schematic side view of a second mode (the crane 1B) of the crane 1 according to the present embodiment. The second mode is also referred to as an SHL-LF mode (super heavy lift luffing mode). The crane 1 is changed to the SHL-LF type crane 1B shown in FIG. 2 by adding or changing other members while sharing some members of the STD-LF type crane 1A shown in FIG. be able to.

  The crane 1 according to the present embodiment includes a lower traveling body 2 capable of self-traveling, an upper revolving body 4 as a crane body mounted on the lower traveling body 2 so as to be able to pivot about a vertical axis, and an upper revolving body 4. And a cab 5 (operator cab) provided at the front end of the vehicle to allow a worker who operates the crane 1 to board the vehicle, and an attachment 10 (an undulating body) attached to the front of the upper revolving unit 4 for performing a lifting operation. ), A mast 12 attached to the upper revolving unit 4 behind the attachment 10, and a counterweight 13 mounted on a rear portion of the upper revolving unit 4 to maintain the balance of the crane 1 and improve stability. And. Note that the front, rear, left and right are defined with reference to the upper revolving unit 4 that turns with respect to the lower traveling unit 2. The direction in which the boom 16 of the attachment 10 described later falls down is the front, and the opposite direction is the rear. The left and right sides are determined based on the front defined by the definition.

  The attachment 10 includes a boom 16, a jib 18, a rear strut 21, a front strut 22, a pair of left and right boom back stops 23, a pair of left and right jib back stops 24, a pair of left and right strut back stops 25, It has a pair of right and left strut guy links 26, a pair of left and right jib guy links 28, a main hook 57, and an auxiliary hook (not shown).

  The boom 16 is attached to a front portion of the upper swing body 4 so as to be rotatable in a rising direction and a falling direction around a horizontal axis (first rotation axis). The boom 16 is a so-called lattice type. The boom 16 can be disassembled into a plurality of parts in the longitudinal direction. That is, the boom 16 has a lower boom 16A, one or more (two in the illustrated example) intermediate booms 16B, 16C, and an upper boom 16D, and these lower boom 16A, intermediate booms 16B, 16C, and upper It can be disassembled into a boom 16D.

  The lower boom 16A is a part including the base end of the boom 16, and is provided at a front portion of the upper revolving unit 4 so as to be rotatable around an axis (first rotation axis) extending in the left-right direction of the upper revolving unit 4. Be linked. Specifically, the base end of the lower boom 16A corresponding to the base end of the boom 16 is connected to the front part of the upper swing body 4 by the boom foot pin 17 extending in the left-right direction. The lower boom 16A is rotatable. A pair of left and right boom backstops 23 are interposed between the lower boom 16A and the upper swing body 4. Specifically, a pair of left and right boom backstops 23 are provided on the upper swing body 4, and come into contact with the left and right sides of the lower boom 16A when the boom 16 takes the standing posture shown in FIG. This abutment restricts the boom 16 from being moved rearward by a strong wind or the like.

  The intermediate booms 16B and 16C are detachably added to the distal end side of the lower boom 16A in that order.

  The upper boom 16D is detachably attached to the distal end side of the intermediate boom 16C. The upper boom 16D has an upper boom main body 19A having a lattice structure connected to the intermediate boom 16C, and a boom head 19B connected to a tip of the upper boom main body 19A. The boom head 19B corresponds to the tip of the boom 16.

  The jib 18 is of a lattice type and has a distal end portion (boom) of the boom 16 so as to be rotatable about the axis extending in the left-right direction (a second rotation axis parallel to the first rotation axis) in a rising direction and a falling direction. Head 19B). Specifically, the jib 18 is one end in the longitudinal direction of the jib 18 and attached to the boom head 19B so as to be rotatable around the axis extending in the left-right direction, and a side opposite to the base end. And a front end portion which is an end portion. The jib 18 can also be disassembled into a plurality of parts in the longitudinal direction. That is, the jib 18 has a lower jib 18A, one or more (one in the illustrated example) intermediate jib 18B, and an upper jib 18C, which are disassembled into a lower jib 18A, an intermediate jib 18B, and an upper jib 18C. It is possible.

  The lower jib 18A is a part including the base end portion of the jib 18, and is disassembled in the longitudinal direction to disassemble the jib 18 into the middle jib 18B and the upper jib 18C which are portions on the distal end side of the jib 18 with respect to the lower jib 18A. On the other hand, the lower jib 18A can be separated. The lower jib 18A is connected to a boom head 19B so as to be rotatable around the axis extending in the left-right direction. Specifically, the base end of the lower jib 18A corresponding to the base end of the jib 18 is connected to the boom head 19B by the jib foot pin 29 extending in the left-right direction, and the lower jib 18A is connected to the boom 16 around the jib foot pin 29. It is rotatable with respect to this.

  More specifically, the boom head 19B has a jib mounting portion 19C at the most forward position of the boom head 19B when the boom 16 stands up as shown in FIG. A pin hole is provided in the jib mounting portion 19C, and a pin hole is also provided in the base end of the lower jib 18A. The jib foot pin 29 is inserted into the pin hole of the lower jib 18A so as to extend in the left-right direction in a state where the pin hole of the jib mounting portion 19C and the pin hole of the base end of the lower jib 18A coincide with each other. The base end is connected to the jib mounting portion 19C via the jib foot pin 29.

  The lower jib 18A is detachable from the jib mounting portion 19C of the boom head 19B. That is, the lower jib 18A can be separated from the jib mounting portion 19C by extracting the jib foot pin 29 from the pin hole.

  A pair of left and right jib backstops 24 are interposed between the lower jib 18A and the boom head 19B. The pair of left and right jib backstops 24 are attached to the boom head 19B, and come into contact with the left and right sides of the lower jib 18A when the jib 18 takes an upright posture as shown in FIG. This abutment restricts the jib 18 from being pushed backward by strong wind or the like.

  The intermediate jib 18B is detachably attached to the distal end of the lower jib 18A. The upper jib 18C is detachably attached to the distal end side of the intermediate jib 18B. The tip of the upper jib 18C corresponds to the tip of the jib 18.

  The rear strut 21 is attached to the boom head 19B so as to be rotatable around the axis extending in the left-right direction. The rear strut 21 has one end in the longitudinal direction and a rear strut base end 21A attached to the boom head 19B, and a rear strut tip 21B which is an end opposite to the rear strut base end 21A. Have.

  The rear strut 21 is held in a posture in which the rear strut 21 projects from the boom head 19B in a direction in which the boom 16 stands (leftward in FIG. 1). As means for maintaining this posture, a pair of left and right strut backstops 25 and a pair of right and left strut guy links 26 are interposed between the rear strut 21 and the boom 16. The strut backstop 25 is interposed between the upper boom 16D and an intermediate portion of the rear strut 21 and supports the rear strut 21 from below. The strut guy link 26 is stretched to connect the rear strut tip 21B and the lower boom 16A, and regulates the position of the rear strut 21 by the tension.

  The front strut 22 is attached to the lower jib 18A so as to be rotatable around the axis extending in the left-right direction. The front strut 22 has one longitudinal end and a front strut proximal end 22A attached to the proximal end of the jib 18, and a front strut distal end that is an end opposite to the front strut proximal end 22A. 22B.

  Between the front strut tip 22B and the tip of the jib 18, a pair of left and right jib guy links 28 are extended so as to connect them. When the jib guide link 28 is stretched, the angle between the front strut 22 and the jib 18 is restricted so as not to be further enlarged. In this state, the front strut tip 22B is pulled toward the rear strut tip 21B, so that the angle between the front strut 22 and the jib 18 is maintained, in other words, the distance between the front strut 22 and the jib 18 is maintained. The front strut 22 and the jib 18 rotate rearward around the jib foot pin 29 while maintaining the relative positional relationship.

  In addition, the above-mentioned rear strut 21 is arranged rearward with respect to the front strut 22. That is, the rear strut 21 is rotated around the axis extending in the left-right direction by the boom head 19B at a position behind the attachment position of the jib 18 to the boom head 19B and at a position behind the attachment position of the front strut 22 to the lower jib 18A. It is movably mounted.

  The mast 12 has a mast base end 12A attached to the upper rotating body 4 at one end in the longitudinal direction, and a mast tip 12B opposite to the mast base end 12A. The mast base end 12A is connected to the upper swing body 4 so as to be rotatable around the axis extending in the left-right direction. The mast tip 12B is connected to the boom head 19B via a pair of left and right boom guy lines 66. This connection causes the rotation of the mast 12 and the rotation of the boom 16 to cooperate.

  The main hook 57 and the auxiliary hook (not shown) are each suspended from the tip of the jib 18 to suspend a load.

  The crane 1 (1A) of the present embodiment includes a boom hoisting winch 30 for raising and lowering the boom 16, a jib hoisting winch 32 for rotating the jib 18 with its base end as a fulcrum, and raising and lowering the jib 18. It further includes a main winding winch 34 and an auxiliary winding winch 36 for lifting and lowering the suspended load. The boom hoisting winch 30, the auxiliary winding winch 36, and the main winding winch 34 are arranged on the upper swing body 4 in this order from back to front. The jib hoisting winch 32 is provided on the lower boom 16A.

  The boom hoisting winch 30 winds and unwinds the boom hoisting rope 38. Then, the boom hoisting rope 38 is routed so that the mast 12 is rotated by the winding and unwinding. Specifically, a sheave block 40 including a plurality of sheaves arranged in the left-right direction is provided at the mast distal end portion 12B, and the rear end of the upper revolving unit 4 is similarly arranged in the left-right direction. Block 42 including a plurality of sheaves arranged as described above. A boom hoisting rope 38 pulled out from the boom hoisting winch 30 is stretched between the sheave blocks 40 and 42. Then, the boom hoisting winch 30 winds or unwinds the boom hoisting rope 38, so that the distance between the two sheave blocks 40 and 42 changes, whereby the mast 12 and the boom 16 interlocking with the mast 12 are changed. Rotates and stands up and falls down. In other words, the boom hoisting rope 38 is indirectly connected to the distal end of the boom 16 via the mast 12 and the boom guy line 66. Note that the boom hoisting winch 30 and the boom hoisting rope 38 constitute a boom drive unit of the present invention. The boom drive unit rotates the boom 16 around the boom foot pin 17 in the rising direction and the falling direction.

  The jib hoisting winch 32 winds and unwinds the jib hoisting rope 44. Then, the jib hoisting rope 44 is routed such that the front strut 22 is rotated by the winding and feeding.

  Specifically, a first guide sheave 45 for jib undulation is provided on the lower boom 16A, and a second guide sheave 46 for jib undulation is provided on the upper boom 16D. Further, a sheave block 47 including a plurality of sheaves arranged in the left-right direction is provided at the rear strut tip 21B, and the sheave block 47 is similarly arranged in the left-right direction at the front strut tip 22B. A sheave block 48 including a plurality of sheaves is provided. Then, the jib hoisting rope 44 pulled out from the jib hoisting winch 32 is sequentially hung on the jib hoisting first guide sheave 45 and the jib hoisting second guide sheave 46, and the sheave block 48 of the front strut tip 22B. And the sheave block 47 of the rear strut tip 21B. Accordingly, the winding and unwinding of the jib hoisting rope 44 by the jib hoisting winch 32 changes the distance between the two sheave blocks 47 and 48, thereby rotating the front strut 22 and the jib 18 interlocking therewith. Stand up and fall down.

  Specifically, the jib hoisting winch 32 raises the jib 18 by winding the jib hoisting rope 44 to rotate the front strut 22 so that the front strut tip 22B approaches the rear strut tip 21B. The front strut tip 22B is turned away from the rear strut tip 21B by rotating the jib hoisting rope 44 while turning the jib 18 in the direction in which the jib 18 is turned down. In other words, the jib hoisting rope 44 is indirectly connected to the distal end of the jib 18 via the front strut 22 and the jib guy link 28. Further, the jib hoisting winch 32, the jib hoisting rope 44, the rear strut 21, the front strut 22, and the jib guy link 28 constitute a jib driving unit of the present invention. The jib driving unit rotates the jib 18 around the jib foot pin 29 in the upright direction and the falling direction.

  The main winding winch 34 hoists and lowers the suspended load by the main winding rope 50. Specifically, a first main winding guide sheave 52 is provided at a position near the base end of the rear strut 21 so as to be rotatable around the axis extending in the left-right direction. The two main winding guide sheaves 53 are provided rotatably around the axis extending in the left-right direction. A third main winding guide sheave 54 is provided at the end of the jib 18 so as to be rotatable around the axis extending in the left-right direction. The left and right guide sheaves 54 are positioned adjacent to the third main winding guide sheave 54. A main winding sheave block including a plurality of main winding point sheaves 56 arranged in a row is provided. The main winding rope 50 pulled out from the main winding winch 34 is sequentially hung on the first, second and third main winding guide sheaves 52, 53, 54, and the main winding point of the main winding sheave block. The sheave is wound around the sheave 56 and a sheave 58 of a sheave block provided on a main hook 57 as a hanging tool. Therefore, when the main winding winch 34 winds or unwinds the main winding rope 50, the distance between the main winding point sheave 56 and the sheave 58 of the main hook 57 changes, thereby changing the tip of the jib 18. The main hook 57 connected to the main winding rope 50 hung from the ceiling is wound up and down. The main hook 57 constitutes the suspension device of the present invention. The main hook 57 hangs down from the tip of the jib 18 and is connected to a suspended load.

  The auxiliary winch 36 raises and lowers the suspended load by the auxiliary rope 60. Regarding the auxiliary winding, the crane 1 includes, in addition to the auxiliary winding winch 36, a first auxiliary winding guide sheave 62, a second auxiliary winding guide sheave 63, a third auxiliary winding guide sheave 64, and an auxiliary sheave. 65. The functions of the members related to the auxiliary winding are the same as the functions of the members related to the main winding.

  Further, the crane 1 includes a pair of left and right wheels 65S (FIGS. 8 and 9). The wheel 65 </ b> S is arranged coaxially with the auxiliary sheave 65 at the tip of the jib 18. The outer diameter of the wheel 65S is set larger than the outer diameter of the auxiliary sheave 65. The wheels 65S roll on the ground when the boom 16 and the jib 18 of the crane 1 are laid down on the ground. As a result, the movement of the boom 16 and the jib 18 during the assembling and disassembling operations of the crane 1 can be easily performed.

  Next, a crane 1B (crane 1) of the SHL-LF form shown in FIG. 2 will be described. The crane 1B is different from the crane 1A in that the crane 1B includes a lattice mast 90, a boom hoisting winch 91, a guy link 92, a boom hoisting rope 93, a guy link 94, and a weight guy link 95. And a pallet weight 96. Therefore, hereinafter, the difference will be mainly described, and the description of the common points will be omitted.

  The lattice mast 90 is rotatably supported by the upper swing body 4 behind the boom 16 and between the mast 12 and the boom 16. When the crane 1 </ b> B is used, the lattice mast 90 is fixed to a position at a predetermined ground angle in the revolving unit 12, so that the lattice mast 90 serves as a support for the rotation of the boom 16. The boom hoisting winch 91 is disposed on the base end side of the lattice mast 90, and winds and unwinds the boom hoisting rope 93. The guy link 92 and the boom hoisting rope 93 are arranged so as to connect the tip of the boom 16 and the tip of the lattice mast 90. Specifically, the guy link 92 extends from the tip of the boom 16 toward the tip of the lattice mast 90. After being pulled out from the boom hoisting winch 91, the boom hoisting rope 93 is wound a plurality of times between a sheave block 97 provided at the tip of the guy link 92 and a sheave block 98 provided at the tip of the lattice mast 90. Has been turned. Guy link 94 connects the tip of mast 12 and the tip of lattice mast 90. The weight guide link 95 connects the tip of the lattice mast 90 and the pallet weight 96. The pallet weights 96 are arranged at intervals behind the upper swing body 4 and maintain the balance of the crane 1B provided with the lattice mast 90. In the crane 1B, the mast hoisting rope 9A is wound between the tip of the mast 12 and the upper swing body 4. A mast hoisting winch 9B is provided on the base end side of the mast 12. The mast hoisting rope 9A is wound and unwound by the mast hoisting winch 9B, whereby the mast 12 and the lattice mast 90 are integrally rotated.

  In the crane 1B, the distance between the sheave block 97 and the sheave block 98 is changed by the boom hoisting winch 91 provided at the base end of the lattice mast 90 winding and unwinding the boom hoisting rope 93. , The boom 16 rotates relatively to the lattice mast 90. As a result, rotation (undulation) of the boom 16 is realized. Further, in the crane 1B, the main winding winch 34 and the auxiliary winding winch 36 are fixed to the lower boom 16A of the boom 16, but the arrangement of these winches is limited to the embodiments of FIGS. is not. In the crane 1B, the lattice mast 90, the boom hoisting winch 91, the guy link 92, and the boom hoisting rope 93 constitute a boom drive unit of the present invention.

  In the present embodiment, similarly to the above-described crane 1 (cranes 1A and 1B), a long jib 18 is connected to the tip of a long boom 16. Then, when such a self-standing operation or a falling operation of the crane 1 is performed, the crane 1 is prevented from overturning.

  FIG. 3 is an electrical block diagram of a configuration for controlling the crane 1 (1A, 1B) according to the present embodiment. The crane 1 includes a control unit 70 that comprehensively controls the operation of the crane 1, a boom angle meter 81 (boom angle detection unit), a jib angle meter 82 (jib angle detection unit), and a front strut angle meter 83. , A jib tension meter 84, an operation unit 85 (input unit), a display unit 86, and a notification buzzer 87.

  The control unit 70 includes a CPU (Central Processing Unit), a ROM (Read Only Memory) for storing a control program, a RAM (Random Access Memory) used as a work area of the CPU, and the like. The control unit 70 includes a boom goniometer 81, a jib goniometer 82, a front strut goniometer 83, a jib tensiometer 84, an operation unit 85, a boom hoisting winch 30 (boom hoisting winch 91), a jib hoisting winch 32, The main winding winch 34 and the like are electrically connected. The control unit 70 may be electrically connected to a hydraulic circuit (for example, a control valve) for driving a hydraulic motor (not shown) connected to these winches.

  The boom angle meter 81 is provided at the base end of the boom 16, detects a ground angle θb of the boom 16 (see FIG. 9), outputs a signal corresponding to the ground angle θb, and inputs the signal to the control unit 70. I do. Similarly, the jib goniometer 82 is provided at the tip of the jib 18, detects the ground angle θj of the jib 18 (see FIG. 5), outputs a signal corresponding to the ground angle θj, and outputs the signal to the controller 70. To enter. Further, the front strut angle meter 83 is provided at the base end of the front strut 22, detects a ground angle (not shown) of the front strut 22, outputs a signal corresponding to the ground angle, and outputs a signal corresponding to the ground angle. To enter.

  The jib tension meter 84 is provided at the tip of the jib 18 and partially holds the tip of the jib guy link 28. The jib tensiometer 84 detects the tension Tm of the jib guy link 28 extending between the tip of the front strut 22 and the tip of the jib 18.

  The operation unit 85 is arranged inside the cab 5 and receives various operations by an operator. In the present embodiment, the operation unit 85 includes a plurality of operation levers and a touch panel type or button type input unit. The plurality of operation levers are used to drive the traveling operation of the lower traveling unit 2, the pivoting operation of the upper revolving unit 4, the winch 30 for boom undulation, the winch 32 for jib undulation, the main winch 34, and the auxiliary winch 36. Receive each operation. The input unit receives operation information of the crane 1 and numerical values of parameters. As an example, the input unit receives length information on the length of the boom 16 and the length of the jib 18, and receives weight information on the weight of the counterweight 13 and the pallet weight 96.

  The display unit 86 is arranged inside the cab 5 similarly to the operation unit 85. The display unit 86 displays various types of operation information of the crane 1. The notification buzzer 87 is disposed inside the cab 5 and outside the cab 5, and reports predetermined warning information to a worker riding on the cab 5 or a worker around the crane 1.

  When the CPU executes the control program stored in the ROM, the control unit 70 executes a mode switching unit 701, a drive control unit 702, an operation control unit 703, a calculation unit 704, a determination unit 705 (an angle condition determination unit, a jib It functions to include a contact state determination unit), a storage unit 706, and an information output unit 707.

  The mode switching unit 701 switches a plurality of modes of the operation restricting unit 703. FIG. 4 is a schematic diagram showing each mode of the operation restricting unit 703 of FIG. The operation restricting unit 703 has a normal operation mode, a self-sustaining laying down mode (falling-allowed mode), and an assembly and disassembly mode.

  The normal operation mode is a mode that allows the crane 1 to perform a normal operation in the working posture of the crane 1 in which the boom 16 stands on the upper swing body 4 and the jib 18 stands on the boom 16. is there.

  In addition, the self-standing fall mode is a mode in which the crane 1 allows the self-standing operation and the fall operation. Specifically, the crane 1 changes the posture from the work posture until the boom 16 and the jib 18 fall forward from the work posture and the tip end of the jib 18 reaches the ground posture. This is a mode that allows Further, the self-standing fall mode is also a mode that allows the crane 1 to change its posture from the above-mentioned fall posture to the above-mentioned work posture (self-stand).

  The assembling / disassembling mode is a mode in which all operations that can be executed in the independent standing mode are allowed, and other operations that are not allowed in the independent standing mode are allowed. As an example, in the disassembly mode, the jib 18 is allowed to be detached from the boom 16, and the boom 16 is allowed to be detached from the upper rotating body 4. In the disassembly mode, the jib 18 is allowed to be mounted on the boom 16, and the boom 16 is allowed to be mounted on the upper swing body 4.

  Switching of the mode of the operation restricting unit 703 by the mode switching unit 701 is performed according to a command input from the operation unit 85 by an operator. As described later, when a predetermined condition is satisfied, the mode of the operation restricting unit 703 is switched by the mode switching unit 701.

  The drive control unit 702 responds to an operation input to the operation unit 85 and controls the crane 1 including the boom hoisting winch 30 (boom hoisting winch 91), the jib hoisting winch 32, the main winding winch 34, and the like. The driving of the driving member is controlled. Specifically, the drive control unit 702 outputs a drive command signal (drive signal) to a hydraulic circuit connected to an electric motor or a hydraulic motor for rotating each winch included in the crane 1.

  The operation restricting unit 703 restricts rotation of the boom 16 and the jib 18 according to a preset mode. In particular, the operation restricting unit 703 has a function of restricting these operations as a safety device when predetermined conditions are satisfied when the crane 1 performs the falling operation or the independent operation. Specifically, the operation restricting unit 703 restricts the rotation of the boom 16 and the jib 18 so that the tip of the jib 18 is included in a work allowable range set according to the load of the suspended load in the working posture of the crane 1. (Moment limiter function). In addition, when the crane 1 is performing the falling operation while the self-standing falling mode is being executed, the movement restricting unit 703 moves the tip end of the jib 18 outside the allowable working range regardless of the load of the suspended load. In addition to allowing the crane 1 to enter, the crane 1 is allowed to change its posture from the working posture to the lying posture. In addition, during the falling operation, the movement restricting portion 703 forms an angle defined by an extension of the center line of the boom 16 and the center line of the jib 18 when viewed from a direction (left-right direction) parallel to the rotation axis of the boom 16. When the jib boom angle condition that is satisfied when the jib offset angle θm (see FIG. 9) is larger than a preset acute angle limit angle θs is satisfied, the standing operation and the falling operation of the boom 16 and the standing of the jib 18 are established. Allows motion and lodging. On the other hand, when the jib boom angle condition is not satisfied during the falling operation, the operation restricting unit 703 outputs an up / down restricting signal for restricting the up / down operation of the boom 16 and the upright operation of the jib 18. In this case, the jib 18 is allowed to fall.

  In addition, when the crane 1 is performing a self-sustaining operation while the self-standing falling mode is being executed and the crane 1 is performing the self-supporting falling mode, the above-described jib boom angle condition is not satisfied and the contact determination condition described later is satisfied. If the determination unit 705 determines that the boom 16 has not been moved, it outputs an up-and-down restriction signal for restricting the up-and-down operation of the boom 16 and the up-down operation of the jib 18. The above-described restricting operation performed by the operation restricting unit 703 will be described later in detail.

  The calculation unit 704 (angle determination unit) performs calculation processing in various flows executed by the control unit 70. The calculating unit 704 calculates and determines the above-described jib offset angle θm from the ground angle θb of the boom 16 detected by the boom angle meter 81 and the ground angle θj of the jib 18 detected by the jib angle meter 82.

  The storage unit 706 can store the offset limit angle θs in advance and output the offset limit angle θs. In the present embodiment, the storage unit 706 stores a plurality of the offset limit angles θs in accordance with a combination of the length of the jib 18, the length of the boom 16, and the weight of the counterweight 13 (pallet weight 96). And outputting a predetermined offset limit angle θs from the plurality of offset limit angles θs according to the length information and the weight information input to the operation unit 85. The storage unit 706 stores the offset limit angle θs in the STD-LF specification shown in FIG. 1 and the SHL-LF specification shown in FIG. 2 in a table format. Note that the storage unit 706 may store and output the offset limit angle θs according to the length information of the boom 16 and the jib 18 irrespective of the weight information of the counterweight 13 (pallet weight 96).

  The determination unit 705 performs a determination process in various flows executed by the control unit 70. In particular, the determination unit 705 determines that the jib boom angle condition is satisfied when the jib offset angle θm determined by the calculation unit 704 is larger than the offset limit angle θs output from the storage unit 706. On the other hand, when the jib offset angle θm is smaller than the offset limit angle θs, it is determined that the jib boom angle condition is not satisfied. Further, the determination unit 705 also has a function as a jib contact state determination unit that determines whether the state of the jib satisfies a predetermined contact determination condition. The contact determination condition is a predetermined condition for determining that the tip of the jib 18 is normally in contact with the ground. The contact determination condition according to this embodiment is that the tension Tm of the jib guy link 28 detected by the jib tensiometer 84 is equal to or less than a certain value, as described later in detail. In other words, when the tension Tm is equal to or greater than a predetermined value, it is determined that a force is applied to the jib 18 such that the jib 18 is lifted from the ground against the weight of the jib 18 or the like. It is determined that the distal end of No. 18 is not in a normal contact state.

  The information output unit 707 receives the undulation control signal from the operation control unit 703, and outputs notification information and a signal corresponding to the information to the display unit 86 and the notification buzzer 87.

  FIG. 5 is a flowchart showing a process for the crane 1 (1A, 1B) according to the present embodiment to shift from the assembly and disassembly mode to the independent standing mode. FIG. 6 and FIG. 7 are flowcharts showing processing in the crane 1 according to the present embodiment in the free-standing falling mode. FIG. 8 to FIG. 14 are process diagrams showing the self-standing falling operation of the crane 1 according to the present embodiment.

<Transition to Independent Standing Mode>
Referring to FIG. 5, in a state where crane 1 is in the working posture (FIG. 1), mode switching unit 701 executes a mode switching determination process from the assembly work mode to the self-standing fall mode for the mode of operation restricting unit 703. I do. The mode switching determination process is executed at predetermined intervals while the crane 1 is in use. When the mode switching determination process is started, the determination unit 705 determines whether the crane 1 is in the LF posture (ruffing posture, corresponding to the work posture in FIG. 1) and the execution mode of the crane 1 is the assembly disassembly mode. (Step S1). Here, when the crane 1 is in the LF posture and is set in the assembling / disassembling mode (YES in step S1), the determination unit 705 stores the tension Tm of the jib guy link 28 detected by the jib tensiometer 84. It is determined whether it is equal to or greater than the tension threshold Ts stored in the unit 706 (step S2). Here, when Ts ≦ Tm is satisfied (YES in step S2), the tension Ts of the jib guy link 28 is sufficiently large, and the jib 18 is supported by the boom 16, in other words, the tip of the jib 18 Since it is determined that the part is floating above the ground against the weight of the jib 18 or the like, the mode can be shifted from the disassembly / disassembly mode to the independent standing mode. Therefore, the mode switching unit 701 cancels the assembling / disassembling mode (step S3), and shifts to the self-standing falling mode (step S4). If the crane 1 is not in the LF posture or in the disassembly mode in step S1 (NO in step S1), the determination in step S1 is repeated by the determination unit 705. Also, in step S2, when Ts> Tm (NO in step S2), steps S1 and S2 are repeated. Note that the transition to the self-standing fall mode by the mode switching unit 701 is not limited to the processing in FIG. For example, a worker in the cab 5 may input a command to shift to the self-standing fall mode through the operation unit 85, and the mode switching unit 701 may switch the mode of the operation restricting unit 703 in response to the command.

<About the processing in the independent sleeping mode>
Referring to FIG. 6, even when mode switching unit 701 starts the independent standing mode of operation restricting unit 703, the falling operation and the independent operation of crane 1 are performed only when a predetermined condition is satisfied. Permissible. In other words, if the predetermined condition is not satisfied, the crane 1 is restricted from falling down and standing up. In the present embodiment, the operation restricting unit 703 of the control unit 70 executes such an allowance and restriction of the operation of the crane 1. In FIG. 6, when the self-standing fall mode is started, the determination unit 705 determines whether or not the crane 1 is in the LF posture (step S11). Here, when the crane 1 is in the LF posture (YES in step S11), the determination unit 705 further determines whether or not the crane 1 has the STD-LF specification (step S12). The information regarding whether the crane 1 is set to the STD-LF specification (FIG. 1) or the SHL-LF specification (FIG. 2) is input by the operator from the operation unit 85 and stored in the storage unit 706. ing. If the crane 1 is not in the LF posture in step S11 (NO in step S11), the determination in step S11 is repeated.

  In step S12, when the crane 1 has the STD-LF specification shown in FIG. 1 (YES in step S12), the operation restricting unit 703 reads the offset limit angle from the STD-LF specification table stored in the storage unit 706. θs (threshold angle) is obtained (step S13). On the other hand, when the crane 1 does not have the STD-LF specification shown in FIG. 1 (NO in step S12), the operation restricting unit 703 acquires the offset limit angle θs from the SHL-LF specification table stored in the storage unit 706. (Step S14). As a result, the offset limit angle θs appropriately set for the current specifications of the crane 1 is determined (step S15). Since the balance of the crane 1 is different between the STD-LF specification and the SHL-LF specification, different offset limit angles θs are set.

  After that, the calculation unit 704 calculates the current jib offset angle θm from the ground angle θb of the boom 16 and the ground angle θj of the jib 18. Then, the determination unit 705 compares the magnitude relationship between the calculated jib offset angle θm and the offset limit angle θs (step S16). Here, when θm ≧ θs (YES in step S16), the jib 18 is in a posture bent sufficiently downward with respect to the boom 16 (the jib boom angle condition is satisfied). For this reason, the operation restricting unit 703 allows the crane 1 to stand alone and fall down in the stand-alone falling mode (step S17, effective stand-alone falling operation). On the other hand, in step S16, when θm <θs, the jib 18 is located at a position closer to the extension of the center line of the boom 16 than when θm ≧ θs (the jib boom angle condition is not satisfied). In this state, if the crane 1 is self-sustained and falls down, there is a concern that the crane 1 may fall forward. Therefore, the operation restricting unit 703 restricts (restricts) the operation of the boom 16 and the jib 18 (step S18).

<Regarding the execution of the self-sustaining lodging operation>
In step S17 of FIG. 6, when the operation restricting unit 703 allows the crane 1 to stand up and fall down, the crane 1 is allowed to stand alone or fall down while the operator operates the operation unit 85. Even after the self-standing operation or the falling operation of the crane 1 is started, if the positional relationship (jib offset angle θm) between the boom 16 and the jib 18 of the crane 1 again becomes unstable, It is necessary to regulate the operation of the crane 1 in order to prevent the crane 1 from overturning. Therefore, the operation restricting unit 703 continuously executes the processing shown in FIG. 7 even during the independent operation or the falling operation of the crane 1.

  If it is determined in step S17 in FIG. 6 that the self-standing fall operation in the crane 1 is valid, the determination unit 705 determines the current mode of the operation restriction unit 703 (step S21 in FIG. 7). Here, if the operation restricting unit 703 is set to the self-standing fall mode (YES in step S21), the determining unit 705 again compares the magnitude relationship between the latest jib offset angle θm and the offset limit angle θs (step S22). ). If θm <θs (YES in step S22), the jib offset angle θm is too small, and the crane 1 may be overturned. Therefore, the determination unit 705 compares the magnitude relationship between the tension Tm of the jib guy link 28 and the first threshold tension Ts1 set in advance and stored in the storage unit 706 (step S23). In step S23 and step S26 to be described later, it is determined whether or not the tip end (wheel 65S) of the jib 18 has landed on the ground G in consideration of a predetermined measurement error in the tension Tm. In addition, the first threshold tension Ts1 is a threshold set for determining whether the tip of the jib 18 (wheel 65S) is grounded.

  If Ts1 ≦ Tm in step S23 (YES in step S23), the tension Tm is larger than the first threshold tension Ts1, that is, the contact determination condition is not satisfied, so that the jib guy link 28 is sufficient. It is determined that tension is generated, that is, a levitation force sufficient to cause the wheel 65S disposed at the tip of the jib 18 to float above the ground is acting. In this case, since the jib offset angle θm is small and the tip of the jib 18 is floating above the ground, the crane 1 may transfer the jib. Therefore, the operation restricting unit 703 restricts at least a part of the operation of the boom 16 and the jib 18 (Step S24). In addition, the operation restricting unit 703 controls the information output unit 707 to notify the worker in the cab 5 and other workers around the crane 1 of the danger, and relates to the possibility of the crane 1 falling over. The information is displayed on the display unit 86 (state warning display). Further, the operation restricting unit 703 causes the notification buzzer 87 to notify a warning buzzer sound (step S25).

  On the other hand, when Ts1> Tm in step S23, since the tension Tm is smaller than the first tension threshold Ts1, the determination unit 705 determines the tension Tm and the second threshold tension Ts2 smaller than the preset first threshold tension Ts1. A comparison is made (step S26). Here, when Tm ≦ Ts2 (YES in step S26), since the tension Tm of the jib guy link 28 is sufficiently small, the jib guy link 28 is slackened, and the wheel 65S disposed at the tip end of the jib 18 is disengaged. It can be regarded as being in a state of normal contact with the ground. For this reason, the movement restricting unit 703 allows all of the standing operation and the falling operation of the boom 16 and the standing operation and the falling operation of the jib 18 (step S27). Further, the operation restricting unit 703 controls the information output unit 707 to notify the worker in the cab 5 and other workers around the crane 1 of the safety of the crane 1 so that the crane 1 is in a normal state. Is displayed on the display unit 86 (normal state display). In addition, when the notification buzzer 87 has previously issued the warning buzzer sound, the operation restricting unit 703 stops the buzzer sound (step S28). On the other hand, in the case where Tm> Ts2 in step S26 (NO in step S26), the wheel 65S disposed at the tip of the jib 18 is not necessarily placed on the ground in consideration of the measurement error of the tension Tm of the jib guy link 28. It cannot be said that they are in normal contact. In other words, it is clear that at least a force acting in the direction of lifting the wheel 65S from the ground is acting against the weight of the jib 18. Therefore, the operation restricting unit 703 maintains the process of FIG. 7 (one of steps S24, S27, and S29) executed last time. Thereafter, the operation restricting unit 703 ends the processing in FIG. 7 and repeats the processing in FIG. 7 at a predetermined interval (for example, several seconds).

  In step S18 of FIG. 6 and step S24 of FIG. 7, the operation restricting unit 703 restricts the operation of the boom 16 and the jib 18. Specifically, when the jib boom angle condition is not satisfied during execution of the fall allowance mode, the operation restricting unit 703 winds the boom hoisting rope 38 (boom hoisting rope 93) around the drive control unit 702. A signal that regulates take-out and extension (raising operation and boom operation of the boom 16) and winding of the jib hoisting rope 44 (raising operation of the jib 18) is output as the above-mentioned fall regulation signal. At this time, the extension of the jib hoisting rope 44 (falling operation of the jib 18) is allowed.

<About the independent operation of the crane>
Next, an independent operation of the crane 1 executed in the process of FIG. 7 will be described with reference to FIGS. 1 and 8 to 14. 8 to 14, the boom 16, the jib 18, the rear strut 21, and the front strut 22 are illustrated, and illustration of other members of the crane 1 (such as the upper swing body 4) is omitted. In the assembling stage of the crane 1, the boom 16 is mounted on the upper swing body 4 (FIG. 1), and the jib 18 is mounted on the tip of the boom 16. Further, a rear strut 21 and a front strut 22 are attached to the distal end of the boom 16 and the proximal end of the jib 18, respectively. Further, the proximal end of the boom 16 and the distal end of the rear strut 21 are connected by a strut guy link 26, and the distal end of the front strut 22 and the distal end of the jib 18 are connected by a jib guy link 28. A jib hoisting rope 44 is wound a plurality of times between a sheave block 47 arranged at the tip of the rear strut 21 and a sheave block 48 arranged at the tip of the front strut 22. Therefore, the jib 18 can be raised and lowered by the winding and unwinding of the jib hoisting rope 44 by the jib hoisting winch 32. Although not shown in FIGS. 8 to 14, a boom guy line 66 is connected to the end of the boom 16 in advance, and the boom hoisting rope 38 is wound by the boom hoisting winch 30 and fed out. The boom 16 can be raised and lowered with the mast 12.

  In the state shown in FIG. 8, the jib guy link 28 is loose, and the tension Tm of the jib guy link 28 detected by the jib tensiometer 84 (FIG. 3) is less than the second threshold tension Ts2 described above. . The jib offset angle θm is equal to zero. For this reason, in the processing in the independent falling mode shown in FIG. 6, the independent falling operation is permitted through steps S11, S12, S13, S15, S16, and S17. As an example, the offset limit angle θs determined in step S15 is 45 degrees.

  In the state shown in FIG. 8, when the self-standing laying mode is started by an instruction from the operator, the operator starts the operation of raising the boom 16 by winding the rope 38 for raising and lowering the boom with the winch 30 for raising and lowering the boom. . As a result, as shown in FIG. 9, the ground angle θb of the boom 16 increases. In the state shown in FIG. 9, as the boom 16 rises, the jib 18 rotates about the jib foot pin 29 and moves rearward so as to follow the boom 16. At this time, the auxiliary sheave 65S arranged at the tip of the jib 18 rolls on the ground. As the jib 18 moves, the ground angle θj of the jib 18 also increases. Note that, with reference to FIG. 9, arithmetic unit 704 (FIG. 3) can calculate θm by the relational expression of jib offset angle θm = θb + θj. In FIG. 9, the jib offset angle θm is about 30 degrees. For this reason, in the process of FIG. 7, the process proceeds from step S22 to S23, but since the tension Tm of the jib guy link 28 is still less than the second threshold tension Ts2, the process proceeds to steps S27 and S28. Therefore, the standing operation of the boom 16 is allowed.

  When the boom 16 continues to be erected from the state shown in FIG. 9, the jib guy link 28 is eventually stretched as shown in FIG. 10, and the tension Tm increases. In FIG. 10, since the jib offset angle θm is 44 degrees, the process of FIG. 7 proceeds from step S22 to S23. If the worker continues the raising operation of the boom 16, the tension Tm becomes larger than the first threshold tension Ts1. Therefore, the process proceeds from step S23 to S24 and S25 in FIG. If the lifting and lowering operation of the boom 16 is continued and the jib 18 rises from the ground, the crane 1 may fall forward, so such a phenomenon is prevented beforehand by the restriction processing by the operation restricting unit 703. At this time, the reason why the falling operation of the boom 16 (extending the rope 44 for raising and lowering the jib) is also limited is that when the boom 16 is lowered while the tip end of the jib 18 is lifted off the ground, the upper swing body 4 and the lower This is because the moment in the direction in which the traveling body 2 is lifted off the ground increases, and the crane 1 may similarly fall over. Further, in order to prevent the tip of the jib 18 from further rising, the rising of the jib 18 (winding of the jib up / down rope 44) is restricted.

  In the case where the above-described restriction is imposed by steps S24 and S25 in FIG. 7, the worker performs the permissible falling motion of the jib 18. That is, when the jib hoisting rope 44 is fed out by the jib hoisting winch 32, the distance between the sheave block 47 and the sheave block 48 increases, and the jib 18 falls down. As a result, the tip end (wheel 65S) of the jib 18 lands again, and the tension Tm falls below the second threshold tension Ts2 (steps S27 and S28 in FIG. 7). That is, the contact determination condition for assuming that the tip portion is normally in contact with the ground is satisfied again. Therefore, the rising operation of the boom 16 can be restarted. Alternatively, when the jib 18 falls down, the jib offset angle θm becomes larger than the offset limit angle θs, so that the operations of the boom 16 and the jib 18 are allowed again.

  Thereafter, when the boom 16 continues to stand up while the state in which the wheels 65S of the jib 18 are in contact with the ground is maintained, the crane 1 is brought into the posture as shown in FIG. In FIG. 11, the jib offset angle θm is about 120 degrees. In this case, since θm> θs (45 degrees), NO is determined in step S22 in FIG. 7, and the standing of the boom 16 is continuously allowed. Then, as shown in FIG. 12, the jib offset angle θm is sufficiently large even if the tip end of the jib 18 floats from the ground as shown in FIG. Thereafter, as shown in FIGS. 13 and 14, the boom 16 continues to stand up, and the crane 1 is set to the working posture as shown in FIG. In FIG. 13, the jib offset angle θm is 60 degrees, while in FIG. 14, the jib offset angle θm is 40 degrees. In this case, based on the processing shown in FIG. 7, the operations of the boom 16 and the jib 18 are restricted in steps S24 and S25, but the ground angle θb of the boom 16 is already at a predetermined angle (boom limit angle, for example, 65 degrees). , And the above-described moment limiter function is activated because the crane 1 is included in the allowable work range. Therefore, the operation restricting unit 703 has forcibly released the processing shown in FIG. In other words, when the erecting operation of the crane 1 is performed by the steps shown in FIGS. 8 to 14, the restriction process executed by the operation restricting unit 703 is a boom limit angle in which the ground angle θb of the boom 16 is set in advance. (65 degrees) It may be performed only in the following cases.

  If the jib offset angle θm falls below the offset limit angle θs in the middle of the state shown in FIGS. 11 to 13, the operation restricting unit 703 controls the operations of the boom 16 and the jib 18 in step S24 of FIG. Restrict based on S25. In this case, when the jib offset angle θm becomes larger than the offset limit angle θs due to the falling down operation of the jib 18, the operation restricting unit 703 can restart the upright operation of the boom 16.

<About the crane's lodging operation>
Next, the falling operation of the crane 1 executed in the process of FIG. 7 will be described with reference to FIGS. 1 and 8 to 14. When it is necessary to change the posture of the crane 1 from the working posture of FIG. 1 to the lying posture of FIG. 8, the operator operates the operation unit 85 to instruct the mode switching unit 701 of the control unit 70 to the self-standing falling mode. Instruct the migration of. At this time, if the execution mode of the crane 1 is set to the assembling / disassembling mode, the mode is shifted from the assembling / disassembling mode to the self-standing falling mode according to the flow shown in FIG. 5 (in the posture of FIG. 1, the tension Tm> Ts. ). In addition, it is desirable to set the disassembly / disassembly mode once in advance when shifting to the self-sustaining laying mode in consideration of the safety of the work, but the execution mode of the crane 1 is directly changed from the normal work mode as described later. A mode in which the mode is shifted to the self-sustaining lodging mode may be employed. In the self-standing fall mode, the boom 16 and the jib 18 are allowed to fall down to a range in which the tip end of the jib 18 exceeds a work allowable range (work allowable radius).

  From the state shown in FIG. 1 until the ground angle θb of the boom 16 falls below a predetermined boom limit angle (65 degrees), the boom 16 is lowered (the boom raising / lowering rope 38 is extended) and the jib 18 is lowered (the jib). Extension of the hoisting rope 44) is allowed. Eventually, through the states shown in FIGS. 14, 13 and 12, the wheel 65S at the tip of the jib 18 lands, as shown in FIG. During this time, when the ground angle θb falls below the predetermined angle (65 degrees), the restriction process by the operation restricting unit 703 can be executed (FIG. 7). During the falling operation of the crane 1, the tension Tm of the jib guy link 28 is larger than the first threshold tension Ts1. Therefore, when the jib offset angle θm becomes smaller than the offset limit angle θs, steps S24 and S25 are executed via steps S22 and S23 in FIG. At this time, in order to prevent the crane 1 from tipping forward, the operation restricting unit 703 moves the boom 16 up and down (winding and unwinding the boom up-and-down rope 38) and upright operation of the jib 18 (the jib up-and-down rope 44). Rewind). Note that, as described above, in order to prevent a moment that causes the upper revolving superstructure 4 to float, the rising operation of the boom 16 is limited, as in the case of the crane 1 being self-standing.

  From the state shown in FIG. 11, the boom 16 and the jib 18 are set to the protruding posture on the ground through the states of FIGS. 10 and 9 by extending the boom hoisting rope 38 and extending the jib hoisting rope 44 (FIG. 10). (FIG. 8). During this time, if the jib offset angle θm falls below the offset limit angle θs in a state where the tension Tm of the jib guy link 28 exceeds the first threshold tension Ts1 due to an unintended operation of the operator or the like, Restriction processing by the operation restriction unit 703 is performed. After the wheels 65S have landed on the ground, the operations of the boom 16 and the jib 18 are all permitted in steps S27 and S28 in FIG.

  Note that, in the self-standing falling operation of the crane 1, the restriction process by the operation restricting unit 703 may be performed only when the tip end of the jib 18 enters outside the preset work allowable range (radius). In other words, when the tip of the jib 18 is located within the allowable working range, the stability of the crane 1 is maintained, so that it is not necessary to restrict the movement of the boom 16 and the jib 18.

  As described above, in the present embodiment, the operation restricting unit 703 that restricts the rotation of the jib 18 and the boom 16 has the normal work mode and the self-standing fall mode (the self-sustaining allowance mode). In the normal operation mode, the operation restricting unit 703 restricts the rotation of the boom 16 and the jib 18 so that the tip of the jib 18 is included in the allowable operation range set according to the load of the suspended load (moment limiter function). . For this reason, the lifting work of the suspended load can be performed safely. On the other hand, in the independent standing mode, the movement restricting unit 703 allows the tip of the jib 18 to enter the outside of the allowable working range regardless of the load of the suspended load, and changes the posture of the crane 1 from the falling posture to the working posture. Allow to do. When the determination unit 705 determines that both the jib boom angle condition and the contact determination condition are not satisfied during the execution of the self-sustaining fall mode, the operation restriction unit 703 outputs a raising / lowering restriction signal to perform the raising / lowering operation of the boom 16. The standing motion of the jib 18 is regulated. The jib boom angle condition is satisfied when the jib offset angle θm is larger than a preset acute angle limit angle θs. For this reason, when the opening angle between the boom 16 and the jib 18 (the outer angle when the jib offset angle is an inner angle) is large, the tip of the jib 18 is prevented from rising from the ground, and the crane 1 is overturned. , The posture of the crane 1 in the state in which the moment limiter function is released can be safely changed from the lying posture to the working posture. As a result, in the self-sustaining work, the burden on the worker of paying attention to the falling of the crane 1 can be reduced.

  In the present embodiment, when the jib boom angle condition is not satisfied in the self-standing fall mode, the operation restricting unit 703 winds and unwinds the boom hoisting rope 38 (boom hoisting rope 93) with respect to the drive control unit 702. And a signal for restricting the winding of the jib hoisting rope 44. For this reason, when the crane 1 is in a posture that is likely to overturn, the driving of the boom hoisting winch 30 (91) and the jib hoisting winch 32 can be quickly restricted.

  In the present embodiment, the crane 1 further includes a jib tensiometer 84 that detects the tension Tm of the jib hoisting rope 44, and the determination unit 705 sets the tension Tm detected by the jib tensiometer 84 in advance. When the tension is equal to or less than the threshold tension Ts, it is determined that the contact determination condition for determining that the tip of the jib 18 is in normal contact is satisfied. According to such a configuration, it is possible to detect whether or not the tip of the jib 18 is normally in contact with the ground using the magnitude of the tension Tm of the jib hoisting rope 44.

  Further, in the present embodiment, when it is determined that both the jib boom angle condition and the contact determination condition are not satisfied in the self-standing fall mode, the operation restricting unit 703 outputs a signal for displaying warning information to the display unit 86. Output. Therefore, it is possible to promptly notify the worker that the crane 1 is in a position where the crane 1 easily falls. As a result, the crane 1 can be prevented from falling down.

  Further, in the present embodiment, the jib offset angle θm can be determined from the detection results of the boom goniometer 81 and the jib goniometer 82 which are usually provided on the crane. As a result, the establishment of the jib boom angle condition can be determined using these goniometers.

  Further, in the present embodiment, the storage unit 706 stores a plurality of offset limit angles θs according to a combination of the length of the jib 18 and the length of the boom 16. Therefore, even if the jib 18 or the boom 16 having a different length is attached to the upper revolving unit 4 and the posture in which the crane 1 easily falls over changes, an appropriate offset limit angle θs can be obtained in accordance with the length information. Can be. Further, the storage unit 706 stores a plurality of offset limit angles θs in accordance with a combination of the length of the jib 18 and the length of the boom 16 and the weight of the counterweight 13 (pallet weight 96). For this reason, even if the counter weight 13 and the pallet weight 96 having different weights are mounted on the upper revolving unit 4 or behind the upper revolving unit 4 and the posture in which the crane 1 easily falls over changes, an appropriate offset limit is set according to the weight information. The angle θs can be obtained.

  As shown in FIG. 7, by determining the magnitude of the tension Tm of the jib hoisting rope 44 during the execution of the self-standing fall mode, the crane 1 changes its posture from the working posture to the lying posture, and In any case when the posture is changed from the lying posture to the working posture, the crane 1 can be prevented from falling. That is, when the posture of the crane 1 is changed from the working posture to the lying posture, the tension Tm of the jib hoisting rope 44 is often larger than the first threshold tension Ts1, so that it is not always necessary to determine the magnitude of the tension Tm. However, by including the determination processing as shown in FIG. 7, it is possible to reliably perform the determination for preventing the crane 1 from overturning in any of the independent operation and the falling down operation of the crane 1 by one flow processing.

  In addition, the method of changing the posture of the crane 1 according to the present embodiment restricts the rotation of the boom 16 and the jib 18 in accordance with a preset normal work mode and a self-standing fall mode (a fall allowance mode, a self-sustain allow mode). Is provided. In the normal operation mode, in the working posture of the crane 1 in which the boom 16 stands up with respect to the upper swing body 4 and the jib 18 stands up with respect to the boom 16, the tip of the jib 18 is subjected to the load of the suspended load. The rotation of the boom 16 and the jib 18 is regulated so as to be included in the work allowable range set accordingly, and the crane 1 is allowed to perform normal work. In the self-standing fall mode (fall allowance mode), the tip of the jib 18 is allowed to enter the outside of the work allowance regardless of the load of the suspended load, and the crane 1 moves the boom 16 and the The jib 18 falls forward from the working posture, and the tip of the jib 18 (wheels 65S) is allowed to change its posture from the working posture to a lying posture in which it has landed on the ground. Further, the method of changing the posture of the crane 1 is an angle defined by an extension of the center line of the boom 16 and the center line 18 of the jib when viewed from a direction parallel to the jib foot pin 29 (second rotation axis). If the jib boom angle condition that is satisfied when the jib offset angle θm is larger than the preset offset limit angle θs (threshold angle) is not satisfied during the falling operation in the self-standing falling mode, the jib 18 Only the operation is permitted, and the raising / lowering operation of the boom 16 and the raising operation of the jib 18 are restricted regardless of the operation received by the operation unit 85. On the other hand, when the jib boom angle condition is satisfied in the falling allowance mode, the crane 1 is moved from the working posture to the falling posture while allowing the raising and lowering operations of the boom 16 and the jib 18. Change posture. According to such a method, the lifting operation of the suspended load can be safely performed in the normal operation mode. On the other hand, in the falling allowance mode, when the posture of the crane 1 is changed from the working posture to the falling posture, the boom 16 or the jib 18 is not moved while the angle between the boom 16 and the jib 18 is large. Therefore, the crane 1 in the state in which the moment limiter function is released can be safely changed from the working posture to the lying posture while preventing the crane 1 from falling forward.

  In addition, the crane 1 in the self-standing falling mode allows the crane 1 to change its posture from the falling posture to the working posture. The method of changing the posture of the crane 1 is such that the jib offset angle θm is smaller than the offset limit angle θs and the tip of the jib 18 normally contacts the ground during the execution of the independent standing mode (independent standing mode). When the contact determination condition for determining that the vehicle is moving is not satisfied, the rising operation and the falling operation of the boom 16 and the rising operation of the jib 18 are restricted, and at least during the execution of the self-standing falling mode. When the jib offset angle θm is larger than the offset limit angle θs or when the contact determination condition is satisfied, the standing operation and the falling operation of the boom 16 and the standing operation and the falling operation of the jib 18 are allowed. While changing the posture of the crane 1 from the lying posture to the working posture. According to such a posture changing method, during the independent operation of the crane 1, the boom 16 or the jib 18 is moved while the angle between the boom 16 and the jib 18 is large, thereby preventing the crane 1 from falling forward. Meanwhile, it is possible to safely change the posture of the crane 1 in the state where the moment limiter function is released from the lying posture to the working posture.

  The crane 1 and the method of changing the posture of the crane 1 according to the embodiment of the present invention have been described above. Note that the present invention is not limited to these modes. The following modified embodiments are possible as the crane according to the present invention.

  (1) In the embodiment described above, the operation restricting unit 703 outputs a signal for restricting the operation of the boom 16 and the jib 18 to the drive control unit 702 when a predetermined condition is satisfied. Is not limited to this. The operation restricting unit 703 outputs a signal for displaying predetermined warning information on the display unit 86 or a signal for sounding the notification buzzer 87 as a lodging control signal without outputting the above signal to the drive control unit 702. May be. In this case, the worker in the cab 5 receives the warning and restricts the operation of the boom 16 and the jib 18, so that the crane 1 can be prevented from falling.

  (2) In the above embodiment, the mode of the operation restricting unit 703 shifts from the assembly and disassembly mode to the independent standing mode in the falling operation of the crane 1 in which the boom 16 and the jib 18 fall from the working posture of FIG. Although described in the embodiment, the present invention is not limited to this. In the working posture of FIG. 1, the mode of the operation restricting unit 703 may be shifted from the normal working mode to the self-standing falling mode. In this case, when there is a concern that the crane 1 may fall over, it is desirable that the transition to the self-standing fall mode is restricted. That is, when the jib boom angle condition is not satisfied in the normal operation mode, the operation restricting unit 703 outputs the mode restriction signal for restricting the switching from the normal operation mode to the self-supporting falling mode (falling allowable mode). It may output to the switching unit 701. According to such a configuration, it is possible to prevent a transition from the normal operation mode to the self-supporting falling mode while keeping the posture in which the crane 1 is likely to fall down.

  (3) Also, in the above embodiment, the crane 1 has been described as being capable of taking the STD-LF form of FIG. 1 and the SHL-LF form of FIG. 2, but the present invention is not limited to this. Not something. In FIG. 2, the crane 1 </ b> B may be of the HL-LF type (heavy lift type) without the weight guy link 95 and the pallet weight 96. Further, the crane 1 is not limited to one that can be changed to a plurality of forms as shown in FIGS. 1 and 2, and may be one form.

  (4) In the above embodiment, the offset limit angle θs is set as a fixed value according to the specifications of the crane 1 (the length of the boom 16 and the jib 18, the weight of the counter weight 13, and the weight of the pallet weight 96). As described above, the offset limit angle θs may be stored in the storage unit 706 as a variable for the ground angle θb of the boom 16 and the ground angle θj of the jib 18. In this case, the optimum offset limit angle θs is applied according to the posture (angle to the ground) of the boom 16 and the jib 18, and the crane 1 can be prevented from tipping over. In other words, when the crane 1 is in a position in which the crane 1 is relatively hard to overturn, the operation of the boom 16 and the jib 18 is prevented from being excessively restricted.

  (5) The “contact determination condition” according to the present invention can be set arbitrarily. In the above embodiment, the magnitude of the tension Tm of the jib guy link 28 is equal to or less than a certain value, that is, a force that causes the tip of the jib 18 or the like to float from the ground against its own weight acts substantially. Not performed is set as a contact determination condition, but the contact determination condition may be a condition for determining that the tip of the jib 18 is actually in contact with the ground. For example, it is determined whether or not the tip of the jib 18 is in contact with the ground based on the rotational torque (roller load) of the wheel 65S, a limit switch, and video information acquired by a camera disposed near the wheel 65S. May be performed.

  Further, in a mode in which the contact determination condition is set based on the tension Tm of the jib guy link 28, the tension threshold for the determination can be set freely. For example, the threshold value is not a value corresponding to a state in which the jib tip completely floats from the ground as in the above-described embodiment, but is a smaller value, that is, the jib tip is actually placed on the ground. The value may be set to a value corresponding to a state in which a levitation force of a certain magnitude or more that is likely to be in contact with but is likely to float from the ground is acting. In other words, the “contact determination condition predetermined to determine whether the tip of the jib is normally in contact with the ground” in the present invention means that the tip of the jib is actually It may be a condition for determining that the jib is in contact with the ground, or that not only the tip of the jib actually contacts the ground but also that the contact pressure is sufficiently large, That is, the condition of “normal contact” may be that no levitation force that may cause the tip to float from the ground is applied.

  (6) In the above embodiment, the jib offset angle θm and the offset limit angle θs are compared to determine that the jib boom angle condition is satisfied. However, the present invention is not limited to this. It is not done. An opening angle between the boom 16 and the jib 18 (an outer angle when the jib offset angle θm is set as an inner angle) may be compared with an opening threshold angle formed of a preset obtuse angle. In this case, when the opening angle is larger than the opening threshold angle, the determining unit 705 determines that the jib boom angle condition is not satisfied.

DESCRIPTION OF SYMBOLS 1 Crane 2 Lower traveling body 4 Upper revolving superstructure (crane body)
5 cab (cab)
10 Attachment 12 Mast 13 Counterweight (weight body)
16 Boom 17 Boom foot pin 18 Jib 21 Rear strut 22 Front strut 26 Guist link for strut 28 Guy link for jib 29 Jib foot pin 30 Winch 32 for boom hoisting winch 34 Winch for main winding 36 Winch for auxiliary winding 38 Boom hoisting Rope 44 jib hoisting rope 50 main winding rope 57 main hook 60 auxiliary winding rope 65S wheels 66 boom guy line 70 control unit 701 mode switching unit 702 drive control unit 703 operation control unit 704 arithmetic unit 705 judgment unit (angle condition judgment unit, Jib contact state determination unit)
706 Storage unit 707 Information output unit 81 Boom angle meter (boom angle detection unit)
82 Jib goniometer (jib angle detector)
83 Front strut angle meter 84 Jib tension meter 85 Operation unit (input unit)
86 Display part 87 Information buzzer 90 Lattice mast 91 Boom hoisting winch 93 Boom hoisting rope 95 Weight guy link 96 Pallet weight (weight body)
9A Mast hoisting rope 9B Mast hoisting winch

Claims (7)

A crane,
The crane body,
A boom rotatably supported on the crane body about a first horizontal rotation axis;
A jib having a base end rotatably supported at a tip end of the boom around a second rotation axis parallel to the first rotation axis and a tip end opposite to the base end;
A boom drive unit configured to rotate the boom in the upright direction and the falling direction around the first rotation axis;
A jib driving section for rotating the jib in the upright direction and the falling direction around the second rotation axis;
An operation unit that receives an operation for driving the boom and the jib;
A drive control unit that outputs a drive signal that controls the boom drive unit and the jib drive unit according to the operation input to the operation unit,
A hanging device that is suspended from a tip of the jib and connected to a suspended load,
An operation restricting unit that restricts rotation of the boom and the jib according to a preset mode, the operation restricting unit includes a normal work mode and a self-sustaining mode, and in the normal work mode, In a working posture of the crane in which the boom stands up with respect to the crane main body and the jib stands up with respect to the boom, a tip end of the jib is included in a work allowable range set according to a load of the suspended load. Restricting the rotation of the boom and the jib so as to allow the tip of the jib to enter the outside of the work allowable range regardless of the load of the suspended load in the self-supporting allowable mode, The crane changes its posture to the working posture from the lying posture in which the boom and the jib fall forward from the working posture and the tip of the jib lands on the ground. Allowing the door, and a movement limiting portion,
A jib contact state determination unit that determines whether the state of the jib satisfies a predetermined contact determination condition to determine that the tip of the jib is normally in contact with the ground. When,
A jib offset angle, which is an angle defined by an extension of a center line of the boom and a center line of the jib when viewed from a direction parallel to the second rotation axis, is larger than a threshold angle including a preset acute angle. An angle condition determining unit that determines whether a jib boom angle condition that is satisfied in the case is satisfied;
With
The operation restricting unit,
In the self-sustaining mode,
When the jib boom angle condition is determined not to be satisfied by the angle condition determination unit, the boom only when the jib contact state determination unit determines that the state of the jib satisfies the contact determination condition. The jib contact state determination unit determines that the jib state does not satisfy the contact determination condition while allowing the jib to rotate in the upright direction and the downward direction and the jib in the upright direction and the downward direction. In the case where the jib is allowed to rotate in the falling direction and the boom is restricted in the rising direction and the falling direction and the jib is turned in the rising direction regardless of the drive signal,
When it is determined by the angle condition determination unit that the jib boom angle condition is satisfied, regardless of the determination result by the jib contact state determination unit, the boom rotates in the upright direction and the falling direction, and the jib rotates. A crane that allows the arm to turn in the upright and downright directions. The crane according to claim 1 or 2,
It further includes a tension detecting unit that detects the tension of the jib hoisting rope,
The crane, wherein the jib state determination unit determines that the contact determination condition is satisfied when the tension detected by the tension detection unit is equal to or less than a preset threshold tension. The crane according to claim 1 or 2,
A driver's cab arranged on the crane main body, which allows an operator operating the crane to board;
A display unit that is arranged in the cab and displays predetermined work information;
Further comprising
In the self-sustaining mode, the operation restricting unit determines that the jib boom angle condition is not satisfied by the angle condition determining unit and determines that the contact determining condition is not satisfied by the jib contact state determining unit. Then, the crane outputs a signal for displaying predetermined warning information on the display unit. The crane according to any one of claims 1 to 3, wherein
A boom angle detection unit that detects a ground angle of the boom,
A jib angle detection unit that detects a ground angle of the jib,
An angle determination unit that determines the jib offset angle from the ground angle of the boom detected by the boom angle detection unit and the ground angle of the jib detected by the jib angle detection unit,
A storage unit that can store the threshold angle in advance and output the threshold angle,
With
The crane determining unit determines that the jib boom angle condition is satisfied when the jib offset angle determined by the angle determining unit is larger than the threshold angle output from the storage unit. . The crane according to claim 4, wherein
An input unit for receiving length information on the length of the jib and the length of the boom,
The storage unit stores a plurality of threshold angles in accordance with a combination of the length of the jib and the length of the boom, and stores the plurality of threshold angles in accordance with the length information input to the input unit. A crane that outputs a predetermined threshold angle from among the threshold angles. The crane according to claim 5, wherein
A weight body that is disposed at a rear portion of the crane main body or rearward of the crane main body and maintains a balance of the crane,
The input unit can further receive weight information on the weight of the weight body,
The storage unit stores a plurality of the threshold angles according to a combination of the length of the jib, the length of the boom, and the weight of the weight body, and stores the length information input to the input unit. And a crane that outputs a predetermined threshold angle from among the plurality of threshold angles according to the weight information. The crane body,
A boom rotatably supported on the crane body about a first horizontal rotation axis;
A jib having a base end rotatably supported at a tip end of the boom around a second rotation axis parallel to the first rotation axis and a tip end opposite to the base end;
An operation unit that receives an operation for driving the boom and the jib;
A method for changing a posture of a crane having
Restricting the rotation of the boom and the jib according to a preset normal work mode and a self-sustaining mode. In the normal work mode, the boom stands up with respect to the crane body and the jib Regulates the rotation of the boom and the jib so that the tip of the jib is included in a work allowable range set in accordance with the load of the suspended load in the working posture of the crane standing up against the boom, In the self-sustaining mode, the tip of the jib is allowed to enter the outside of the work allowance irrespective of the load of the suspended load, and the boom and the jib fall forward from the work posture and fall. Allowing the crane to change its posture from the falling posture in which the tip of the jib lands on the ground to the working posture,
In the self-sustaining mode, a jib offset angle which is an angle defined by an extension of a center line of the boom and a center line of the jib when viewed from a direction parallel to the second rotation axis is a threshold angle set in advance. Is small, and when the state of the jib does not satisfy a predetermined contact determination condition for determining that the tip end of the jib is normally in contact with the ground, the jib falls down. Direction, and restricts the boom from turning in the upright direction and the falling direction and the jib in the upright direction regardless of the operation received by the operating unit, and at least in the self-sustaining mode. If the jib offset angle is larger than the threshold angle or the contact determination condition is satisfied, the boom does not rotate in the rising direction and the falling direction. Wherein while allowing the rotation of the upright direction and lodging direction of the jib in beauty, and that attitude changing the working position of the crane from the horizontal position,
A method of changing the posture of a crane provided with a method.

Images