JP2017178502A - Crane overload prevention system and structure construction method using crane overload prevention system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crane overload prevention system that is capable of improving work efficiency by using a crane capacity, and a structure construction method using the crane overload prevention system.SOLUTION: This crane overload prevention system is configured such that the work radius of a jib is calculated on the basis of an inclination angle measured by a jin angle detector 30, a rated load is calculated by a rated load curve on the basis of the work radius, when a rear load measured by a load detector 20 exceeds the rated load, for an overload prevention device 40 that outputs the work stop signal of a climbing crane, a plurality of rated load curves are set for every lifting operations of the climbing crane, and a rated load curve is selected according to a used lifting operation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a crane overload prevention system and a construction method using the crane overload prevention system.

  In general, a climbing crane is used to construct a structure such as a high-rise building and has a structure as shown in FIG.

  In FIG. 4, reference numeral 1 denotes a climbing crane. The climbing crane 1 includes a mast 2 that is installed on a floor board inside a structure and that can sequentially add mast blocks 2 a upward. On the top of the mast 2, a revolving body 4 is disposed so as to be able to swivel through an elevating unit 3 that can move up and down along the mast 2. The swivel body 4 is provided with a jib 5 that can be raised and lowered, and is integrally provided with a counter frame 6 that extends rearward. On the counter frame 6, a hoisting device 9 for hoisting and lowering a hoisting wire rope 8 for hoisting a hoisting tool 7 for hoisting the load from the tip of the jib 5, and a wire rope 10 for raising and lowering the jib 5 are provided. A hoisting device 11 for hoisting and lowering is installed.

  For example, Patent Document 1 shows a general technical level related to the climbing crane 1 as described above.

  On the other hand, the climbing crane 1 includes a load detector 20, a jib angle detector 30, an overload prevention device 40, a controller 50, and a display 60, as shown in FIG. Yes.

  The load detector 20 is constituted by a load cell or the like that detects a tension acting on the suspended wire rope 8 and measures an actual load caused by the suspended load acting on the climbing crane 1.

  The jib angle detector 30 measures the inclination angle of the jib 5.

  The overload prevention device 40 sets a rated load curve with respect to the working radius of the jib 5, obtains the working radius of the jib 5 based on the inclination angle measured by the jib angle detector 30, and determines the working radius based on the working radius. The rated load is obtained from the rated load curve, and when the actual load measured by the load detector 20 exceeds the rated load, an operation stop signal of the climbing crane 1 is output.

  The controller 50 (PLC: Programmable Logic Controller) is configured to urgently stop the operation of the climbing crane 1 when an operation stop signal output from the overload prevention device 40 is input.

  The display 60 displays the actual load, the working radius of the jib 5, and the like, and displays an alarm when an operation stop signal output from the overload prevention device 40 is input. .

  As shown in FIG. 5B, the rated load curve set in the overload prevention device 40 is horizontal until the working radius increases to a certain value due to the jib 5 falling from the standing state. After the displacement and the maximum rated load are maintained and the working radius exceeds a certain value, the rated load gradually decreases as the working radius increases as the jib 5 collapses. Yes.

JP 2004-59321 A

  By the way, when constructing a structure such as a high-rise building with the climbing crane 1 as described above, it starts with work at a low lift (for example, 50 m or less) and finally works at a maximum lift (for example, 250 m). It becomes.

  However, in the conventional climbing crane 1, as shown in FIG. 5 (b), the load rating curve allows for the weight of the suspended wire rope 8 that is fed from the tip of the jib 5 when working at the maximum lift. Therefore, the suspension load is reduced by the weight of the suspension load wire rope 8 when working at a low head.

For example, the weight per unit length of the suspended wire rope 8 is 2.33 kg / m, and the multiplying factor of the suspended wire rope 8 between the tip of the jib 5 and the suspended tool 7 is 4. If it is a book,
2.33 × 4 × (250-50) / 10 ³ ≈1.9 t
Is lost when working at low heads.

  In particular, when starting construction of a structure such as a high-rise building, in the work at the low head, in order to perform the foundation and the low-rise part, heavier members are often lifted than the high-rise part. The current situation is that the ability of the climbing crane 1 cannot be efficiently demonstrated for the reason.

  Incidentally, it is not impossible to increase the maximum load rating only when working at a low head. In this case, however, the crane type and type (for example, 32 t) of the crane specification that is required to be submitted when the climbing crane 1 is installed. Climbing type jib crane) and lifting load (for example, 33.8t) must be changed, and the operation stop period of the climbing crane 1 associated with the change becomes long. For this reason, it is not realistic to increase the maximum load rating only when working at a low head, and adoption has been postponed.

  The present invention has been made in view of the above-described conventional problems. A crane overload prevention system capable of effectively utilizing crane capacity to improve work efficiency, and a structure construction using the crane overload prevention system. Is to provide a method.

The present invention is a load detector for measuring an actual load due to a suspended load acting on a crane,
A jib angle detector that measures the tilt angle of the jib,
A load rating curve for the working radius of the jib is set, the working radius of the jib is obtained based on the inclination angle measured by the jib angle detector, the rated load is obtained from the rated load curve based on the working radius, and the load detection In an overload prevention system for a crane equipped with an overload prevention device that outputs a crane operation stop signal when the actual load measured by the machine exceeds the rated load,
The overload prevention device is a crane overload prevention system in which a plurality of load rating curves are set for each lift of the crane, and a load rating curve corresponding to the lift to be used is selected.

  In the crane overload prevention system, it is preferable that the plurality of rated load curves are set such that a maximum rated load is not influenced by a head.

Further, the present invention is a structure construction method using the crane overload prevention system,
The crane is a climbing crane;
A low-rise construction step of constructing a structure with the climbing crane in a state in which the rated load curve corresponding to the lowest lift is selected among the plurality of rated load curves of the climbing crane;
The present invention relates to a structure construction method using an overload prevention system for a crane that performs a non-low-rise construction process for constructing a structure with the climbing crane in a state where a rated load curve corresponding to a lift to be used is selected.

  According to the crane overload prevention system of the present invention and the structure construction method using the crane overload prevention system, the crane efficiency can be effectively utilized to improve the work efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the Example of the structure construction method using the overload prevention system of the crane of this invention and the overload prevention system of this crane, Comprising: (a) is a block diagram, (b) is a rated load curve figure. It is. It is a flowchart which shows the Example of the structure construction method using the overload prevention system of the crane of this invention and the overload prevention system of this crane. It is a climbing step figure which shows the low-rise construction process and the high-rise construction process in the Example of the construction construction method using the overload prevention system of the crane of this invention, and the overload prevention system of this crane. It is a schematic block diagram which shows a general climbing crane. It is a schematic diagram which shows a prior art example, Comprising: (a) is a block diagram, (b) is a rated load curve figure.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 to 3 show an embodiment of a crane overload prevention system and a structure construction method using the crane overload prevention system of the present invention. In the drawings, the same reference numerals as in FIGS. 4 and 5 are used. The attached parts represent the same thing, and the basic configuration is the same as the conventional one shown in FIGS.

  A feature of the present embodiment is that, as shown in FIGS. 1A and 1B, a plurality of rated load curves are set and used for the overload prevention device 40 for each lift of the climbing crane 1. The point is that the rated load curve corresponding to the head is selected.

  In the case of the present embodiment, two types of rated load curves are set: a low lift rated load curve and a high lift rated load curve.

  The plurality of rated load curves (low lift rated load curve and high lift rated load curve) are set such that the maximum rated load is the same value (a value that does not depend on the lift).

  Next, the operation of the above embodiment will be described.

  When constructing a structure such as a high-rise building, first, as shown in FIG. 2, low head selection switching is performed (see step S1), and climbing is performed with the low head rated load curve shown in FIG. 1B selected. Construction of the structure is started by the crane 1. This becomes a low-rise construction process, and in this low-rise construction process, construction of a foundation and a low-rise part is performed. During the low-rise building process, the load detector 20 measures the actual load due to the suspended load acting on the climbing crane 1, and the jib angle detector 30 measures the inclination angle of the jib 5. In the overload prevention device 40, the working radius of the jib 5 is obtained based on the inclination angle measured by the jib angle detector 30, and the rated load is obtained from the rated load curve for low lift based on the working radius. If the actual load measured by the load detector 20 is equal to or lower than the rated load, the construction of the lower layer is continued as it is.

  When it is determined that the low-rise construction process has been advanced and climbing has been performed exceeding a set height (for example, 50 m) (see step S2), and climbing has been performed beyond the set height A password is entered by the crane administrator (see step S3). When the correct password is entered, high lift selection switching is performed (see step S4), and the construction of the structure is continued by the climbing crane 1 with the high lift rated load curve in FIG. 1B selected. The This becomes a high-rise building process (non-low-rise building process), and in the high-rise building process, construction of the high-rise part is performed. Even during the high-rise construction process, the load detector 20 measures the actual load due to the suspended load acting on the climbing crane 1, and the jib angle detector 30 measures the inclination angle of the jib 5. In the overload prevention device 40, the working radius of the jib 5 is obtained based on the inclination angle measured by the jib angle detector 30, and the rated load is obtained from the rated load curve for the high head based on the working radius. If the actual load measured by the load detector 20 is equal to or less than the rated load, the construction of the high-rise portion is continued as it is.

  When the actual load measured by the load detector 20 exceeds the rated load during the low-rise construction process and the high-rise construction process, an operation stop signal of the climbing crane 1 is output to the controller 50, and the climbing crane 1 is urgently stopped, and the display 60 displays the actual load, the working radius of the jib 5, and the like, and an alarm.

  Thus, when constructing a structure such as a high-rise building with the climbing crane 1, as shown in FIG. 3, the work starts at a low head (for example, 50 m or less) and finally reaches a maximum head (for example, 250 m). In this embodiment, as shown in FIG. 1 (b), the rated load curve assumes the weight of the wire rope 8 for the suspended load that is fed out from the tip of the jib 5 when working at the maximum lift. In addition to the high load rated load curve, the low lift rated load curve is set to be switchable. Thereby, unlike the conventional climbing crane 1, the weight (for example, 1.9t) of the wire rope 8 for hanging load hung between the tip of the jib 5 and the hanging tool 7 at the time of the operation | work at a low lift. It is avoided that the suspension load is reduced by that amount.

  In particular, when starting construction of a structure such as a high-rise building, in the work at a low head, in order to construct the foundation and the low-rise part, heavier members are often lifted than the high-rise part. Such a heavy member that was impossible with the climbing crane 1 can be lifted in this embodiment, and the ability of the climbing crane 1 can be efficiently exhibited.

  The plurality of rated load curves (low lift rated load curve and high lift rated load curve) are set such that the maximum rated load is set to the same value (value not affected by the lift). It is not necessary to change the crane type and type (for example, 32t climbing type jib crane) and the lifting load (for example, 33.8t) of the crane specification that is required to be submitted at the time of installation application 1. As a result, it is possible to avoid the operation stop period of the climbing crane 1 accompanying the crane installation application from becoming long.

  Thus, it is possible to improve the work efficiency by effectively utilizing the crane capacity.

  In this embodiment, the switching between the low lift rated load curve and the high lift rated load curve is performed manually, but as shown by the phantom line in FIG. 1A, an encoder for measuring the lift of the climbing crane 1 It is also possible to automatically switch the head mode based on the detected value from the head detector 70 such as the above. Instead of the lift detector 70, the lift mode may be automatically switched based on the detection value from the position detector 80 that measures the position of the climbing crane 1 in the height direction.

  In the case of the present embodiment, the rated load curve has two types of rated load curve for low lift and rated load curve for high lift. The rated load curve for low lift and the rated load curve for intermediate lift are set. Needless to say, it is possible to set three kinds of rated load curves such as a rated load curve for a high head, or three or more kinds of rated load curves. Correspondingly, in the structure construction method in the present embodiment, not only the two steps of the low-rise building step and the high-rise building step, but also subdividing the high-rise building step, the low-rise building step and a plurality of non-low-rise layers You may make it perform a construction process.

  Furthermore, it goes without saying that the present invention is applicable not only to the climbing crane 1 but also to a crane used in construction where a hole is dug underground, or a crane used to dismantle a structure. By the way, when applied to these cranes, the shape changes from a high head to a low head. In addition, as a structure, not only a high-rise building but a steel tower and a tower are also included.

  In this embodiment, the plurality of rated load curves are set so that the maximum rated load is the same value (a value that does not depend on the head). If comprised in this way, the change of the crane kind of a crane specification and the type and lifting load which are obliged to submit at the time of the application for installation of the climbing crane 1 becomes unnecessary, and the operation stop period of the climbing crane 1 accompanying the crane installation application is extended. This can be avoided and is preferable.

  Moreover, in the case of the structure construction method in the present embodiment, the construction of the structure is started by the climbing crane 1 in a state in which the rated load curve corresponding to the lowest lift is selected from the plurality of rated load curves of the climbing crane 1. And a non-low-rise building step of building a structure with the climbing crane 1 in a state where a rated load curve corresponding to a lift to be used is selected. If comprised in this way, it becomes possible to lift a heavier member than a high-rise part at the time of the work at the low head where construction of a foundation and a low-rise part in a structure is performed, and the ability of climbing crane 1 is demonstrated more efficiently. It becomes very effective.

  The crane overload prevention system of the present invention and the structure construction method using the crane overload prevention system are not limited to the above-described embodiments, and do not depart from the spirit of the present invention. Of course, various changes can be made.

1 Climbing crane (crane)
5 Jib 20 Load detector 30 Jib angle detector 40 Overload prevention device

Claims (3)

A load detector for measuring the actual load due to the suspended load acting on the crane;
A jib angle detector that measures the tilt angle of the jib,
A load rating curve for the working radius of the jib is set, the working radius of the jib is obtained based on the inclination angle measured by the jib angle detector, the rated load is obtained from the rated load curve based on the working radius, and the load detection In an overload prevention system for a crane equipped with an overload prevention device that outputs a crane operation stop signal when the actual load measured by the machine exceeds the rated load,
In the overload prevention system, a plurality of rated load curves are set for each lift of the crane, and a load rating curve corresponding to a lift to be used is selected.   The crane overload prevention system according to claim 1, wherein the plurality of rated load curves are set as values in which the maximum rated load does not depend on the head. A structure construction method using the crane overload prevention system according to claim 1 or 2,
The crane is a climbing crane;
A low-rise construction step of constructing a structure with the climbing crane in a state in which the rated load curve corresponding to the lowest lift is selected among the plurality of rated load curves of the climbing crane;
A structure construction method using a crane overload prevention system which performs a non-low-rise construction step of constructing a structure with the climbing crane in a state where a rated load curve corresponding to a lift to be used is selected.

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