JP5939243B2 - Crane load deriving device - Google Patents

Description

  The present invention relates to a crane load deriving device.

  2. Description of the Related Art Conventionally, a crane is provided with a winch that winds and unwinds an object (a hoisting member such as a boom or a jib or a hook device) via ropes wound around a plurality of sheaves. And in such a crane, the load calculating apparatus which detects the load applied to a rope and calculates the crane's suspension load based on the detected value is provided. Patent Documents 1 and 2 below show an example of such a crane load calculation device.

  The load calculation device disclosed in Patent Literature 1 calculates a crane suspension load from a load detection value of a boom hoisting rope for hoisting and lowering a boom (boom hoisting). Since the load detection value of the boom hoisting rope includes an error due to the rotational resistance (sheave efficiency) of the sheave on which the boom hoisting rope is hung, this load calculation device corrects the error included in the load detection value. The crane's suspended load is calculated from the corrected load detection value.

  Specifically, since the rotational resistance of the sheave acts reversely at the time of hoisting and lowering of the boom, in the load calculation device of Patent Document 1, when the hoisting operation lever is operated to the hoisting side, the boom is unwound. The hoisting load is calculated from the detected load of the hoisting rope using hoisting hoisting load data indicating the relationship between the hoisting load and the hoisting rope tension. The hoisting load is calculated from the detected load value of the hoisting rope using the hoisting hoisting load data indicating the relationship between the hoisting load at the time of lowering and the tension of the hoisting rope. And in patent document 1, since the state of the tension | tensile_strength which acts on a hoisting rope and the operating state of a hoisting operation lever do not correspond in the transition period from the operation of the hoisting operation lever until the movement of a sheave etc. will be in a steady state. The suspension load is calculated using the suspension load data corresponding to the operation of the hoisting operation lever to the winding side or the lowering side after a predetermined elapsed time corresponding to the transition period.

  Moreover, the load calculating device disclosed in Patent Document 2 is based on a load detection value (measured value of load) of a lifting wire as a hoisting rope for lifting and lowering a hook block for hanging a suspended load. The suspended load is calculated. In this load calculation device, it is detected whether the sheave around which the lifting wire is wound is rotating to the upper side or the lower side of the suspended load, and the load is detected according to the detected rotation direction of the sheave. The error due to the frictional force (sheave rotational resistance) with respect to the rotation axis of the sheave included in the value is corrected, and the suspended load is calculated from the detected load value after the correction.

JP 2006-327815 A JP 2010-228900 A

  In both the load calculation device disclosed in Patent Document 1 and the load calculation device disclosed in Patent Document 2, there is a possibility that a load display that gives an uncomfortable feeling to an operator or the like may be displayed. The reason is as follows.

  In the load calculation device disclosed in Patent Document 1, when the hoisting operation lever is operated in the operation direction opposite to the operation direction before the hoisting operation lever is stopped and the hoisting rope moves in the direction corresponding to the operation, The load data used for correcting the load detection value is switched from the load data corresponding to the operation direction before stopping to the load data corresponding to the reverse operation direction. However, the undulation rope moves in the direction in which the sheave rotation resistance acts. It does not switch instantaneously when it starts. In other words, the direction in which the sheave's rotational resistance acts gradually changes as the sheave rope starts to move with the movement of the hoisting rope, and after the transitional period of the change has passed, the rotational resistance corresponds to the operation direction after switching. It becomes a constant value that acts in the selected direction. Therefore, the switching of the load data used for correcting the load detection value in Patent Document 1 does not correspond to the actual change in the rotational resistance of the sheave, and when the load data used for correction is switched. The load detection value is corrected by a correction value far from the actual sheave rotation resistance. As a result, in the suspended load calculated from the load detection value after such correction, a sudden change portion of the value resulting from the correction occurs, and the calculated suspended load value is displayed. This will give you a sense of incongruity.

  Further, in the load calculation device disclosed in Patent Document 2, since the correction value for correcting the load detection value is switched when the rotation direction of the sheave is switched, this correction is also performed for the sheave in the transient period. It does not correspond to the change of rotation resistance. Therefore, even with the load calculation device of Patent Document 2, there is a possibility that a sudden change portion of the value resulting from the correction may occur in the calculated suspension load, and when the calculated suspension load value is displayed, a sense of incongruity is given. .

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a crane load deriving device capable of realizing a load display that does not give a sense of incongruity.

In order to achieve the above object, a crane load deriving device according to the present invention includes a winch that winds and unwinds an object through the rope by rotating a drum around which a rope wound around a sheave is wound. A load deriving device for deriving a hanging load of the crane, the load detector for detecting a load applied to the rope; and A direction output unit that outputs a direction indicator signal indicating the moving direction of the rope to the winding side or the lowering side of the object, and a moving amount that represents the moving amount of the rope to the winding side or the lowering side of the object A movement amount output unit that outputs an index value, and a first tension value of the rope is derived from a load value detected by the load detector, and is included in the derived first tension value. It performs correction for reducing the error caused by the rotational resistance of over blanking, and a load calculating unit for determining the suspended load from the second tension value is a first tension value after the correction, the movement amount output unit Drum rotation detection that detects the amount of rotation of the drum corresponding to the amount of movement of the rope to the upper or lower side of the object and outputs data of the detected amount of rotation as the movement amount index value The load calculation device corrects the first tension value by a correction value corresponding to the moving direction of the rope represented by the direction indicator signal, and also moves the sheave when the object is rolled up and down. The transition of the correction mode between the increase correction in the direction in which the first tension value is increased and the decrease correction in the direction in which the first tension value is decreased in the transition period until the rotation resistance of the drum becomes constant. Exit from the detector The stepwise changes the correction value to stepwise performed with increasing amount of rotation of the drum as the moving amount index value (claim 1).

  The crane load deriving device according to the present invention includes a winch that winds and lowers an object through a rope wound around a sheave, and performs a lifting operation by winding and unwinding the object. A load deriving device for deriving a suspension load of the crane, a load detector for detecting a load applied to the rope, and a moving direction of the rope toward the winding or unwinding side of the object Detected by the load detector, a direction output unit that outputs a direction indicator signal that represents, a movement amount output unit that outputs a movement amount index value that represents the amount of movement of the rope toward the upper or lower side of the object, and the load detector A first tension value of the rope is derived from the calculated load value, and a correction is performed to reduce an error caused by the rotational resistance of the sheave included in the derived first tension value. A load calculating device that obtains the suspension load from the second tension value that is the first tension value, and the movement amount output unit calculates an actual movement amount of the rope to the upper side or lower side of the object. It is a movement amount detector that detects and outputs data of the actual movement amount of the detected rope as the movement amount index value, and the load calculation device corresponds to the movement direction of the rope represented by the direction indicator signal. The first tension value is corrected by the correction value, and the increase correction is performed in the direction in which the first tension value is increased in a transient period until the rotational resistance of the sheave becomes constant when the object is rolled up and down. And a correction mode shift between the first tension value and the decrease correction in the direction of decreasing the first tension value according to an increase in the actual movement amount of the rope as the movement amount index value output from the movement amount detector. I will do it Stepwise varying the correction value (claim 2).

In the load deriving device described above, the load calculation device represents the shift amount of the rope between the increase correction and the decrease correction in the transition period during winding and unwinding of the object. Since the correction value is changed stepwise so as to be stepwise according to the increase of the movement amount index value, there is a portion where the value suddenly changes to the corrected first tension value by the correction of the first tension value in the transient period. It can be prevented from occurring. For this reason, it is possible to prevent a portion where the value suddenly changes in the value of the suspended load calculated from the second tension value that is the corrected first tension value, and based on the calculated suspended load value. Thus, load display that does not give a sense of incongruity can be realized.

In the load deriving device, the load calculating device may move a plurality of patterns indicating a correlation between the movement amount index value and the correction value in the transition period that is different for each shape of the sheave around which the rope is wound. Storing the amount correction value correlation, selecting the movement amount correction value correlation according to the shape of the sheave on which the rope is currently wound from the movement amount correction value correlation of the plurality of patterns, it is preferred to derive the correction value for correcting the first tension value of the transition period using the selected displacement amount correction value correlation (claim 3).

  The error of the first tension value due to the rotational resistance of the sheave differs depending on the shape of the sheave on which the rope is hung. However, according to this configuration, the error depends on the shape of the sheave on which the rope is hung. Based on the pattern movement amount correction value correlation, a correction value capable of accurately correcting the error of the first tension value corresponding to the current sheave form can be derived. For this reason, the first tension value in the transition period can be appropriately corrected according to the shape of the sheave on which the rope is currently wound.

In this case, the shape of the sheave may be the number of the sheaves around which the rope is hung (Claim 4 ).

  According to this configuration, it is possible to appropriately correct an error in the first tension value during the transition period caused by a different rotational resistance depending on the number of sheaves on which the rope is wound.

In the load deriving device, the object is a hoisting member provided so as to be hoistable in the crane, and the winch is a hoisting winch that winds and lowers the hoisting member via the rope. (Claim 5 ).

  According to this configuration, in the load deriving device that calculates the first tension value of the hoisting rope from the load value applied to the hoisting rope and derives the crane's suspension load based on the calculated first tension value, the transient period The load display which does not give a sense of incongruity can be implement | achieved by correct | amending appropriately the error of the 1st tension value of the hoisting rope.

In the load deriving device, the object may be a hook device for hanging a suspended load, and the winch may be a hoisting winch that winds and lowers the hook device via the rope ( Claim 6 ).

  According to this configuration, the first tension value of the hoisting rope is calculated from the load value applied to the hoisting rope connected to the hook device, and the crane's suspension load is derived based on the calculated first tension value. In the load deriving device, it is possible to appropriately correct the error of the first tension value of the hoisting rope during the transition period and to realize a load display that does not give a sense of incongruity.

  As described above, according to the present invention, it is possible to realize a load display that does not give a sense of incongruity.

It is a side view of the crane with which the load derivation device by one embodiment of the present invention is applied. It is a schematic diagram for demonstrating the structure of the hoisting rope hung in the crane shown in FIG. 1, and the attachment position of a load detector. It is a functional block diagram of the load derivation device by one embodiment of the present invention. It is a flowchart which shows the derivation process of the suspended load value by the load derivation device of one embodiment of the present invention. It is a figure which shows the time-dependent change of tension | tensile_strengthening rope tension | tensile_strength, the operation state of a lever, and a load display in one Embodiment of this invention. It is a figure which shows the time-dependent change of the tension of the hoisting rope, the operation state of a lever, and a load display in the comparative example of this invention. It is a figure which shows the time-dependent change of tension | tensile_strengthening rope tension | tensile_strength, the operation state of a lever, and a load display in another comparative example of this invention. It is a figure which shows the time-dependent change of the tension | tensile_strength rope tension, the operation state of a lever, and a load display in another comparative example of this invention. It is a schematic diagram which shows the structure of the winding of the main winding rope in the modification of this invention. It is a figure for demonstrating the load applied to a load detector from a main winding rope in the structure of the modification shown in FIG. It is a functional block diagram of the load derivation device by the modification of the present invention. It is a figure which shows the time-dependent change of the tension | tensile_strength of the main winding rope in the modification of this invention, the operation state of a lever, and a load display.

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

  First, with reference to FIGS. 1-3, the whole structure of the crane provided with the load derivation device by one Embodiment of this invention is demonstrated.

  As shown in FIG. 1, the crane includes a lower traveling body 2 capable of self-propelling and an upper revolving body 4 mounted on the lower traveling body 2 so as to be capable of turning.

  The upper swing body 4 is provided with a boom 6 that can be raised and lowered. The boom 6 is an example of the object of the present invention, and is an example of the hoisting member of the present invention. A main hook device 8 and an auxiliary hook device 9 are suspended from the tip of the boom 6. The main hook device 8 is suspended from the tip of the boom 6 via the main winding rope 10, and the auxiliary hook device 9 is suspended from the tip of the boom 6 via the auxiliary winding rope 11.

  Further, the main revolving body 4 is configured to wind / unwind the main hook rope 10 to wind / unwind the main hook device 8 and the unillustrated suspended load suspended by the main hook device 8. A winch 12 and an auxiliary winding winch 13 for winding / unwinding an unillustrated suspended load suspended by the auxiliary hook device 9 by winding / unwinding the auxiliary winding rope 11 are provided. It has been.

  A gantry 16 is erected on the upper swing body 4, and two gantry peak sheaves 18 (see FIG. 2) are coaxially provided at the upper end of the gantry 16. The gantry peak sheave 18 is supported by a rotating shaft 18a extending in the horizontal direction so as to be rotatable about the axis. As shown in FIG. 1, a lower spreader 20 is provided in front of the upper end of the gantry 16. The lower spreader 20 has a plurality of lower sheaves 20a (see FIG. 2). These lower sheaves 20a are supported by corresponding rotary shafts 20b so as to be rotatable around the respective shafts.

  An upper spreader 22 is provided so as to be spaced forward from the lower spreader 20. The upper spreader 22 has a plurality of upper sheaves 22a (see FIG. 2). These upper sheaves 22a are supported by corresponding rotary shafts 22b so as to be rotatable about the respective axes. As shown in FIG. 1, the upper spreader 22 is connected to the tip of the boom 6 via a guy cable 24.

  The upper swing body 4 is provided with a undulating winch 26. As shown in FIG. 2, the hoisting rope 28 drawn out from the drum 26a of the hoisting winch 26 is hung on one gantry peak sheave 18 and then hung around a plurality of upper sheaves 22a and a plurality of lower sheaves 20a. Further, after being hooked on the other gantry peak sheave 18, the load detector 42 is connected. That is, the end of the hoisting rope 28 opposite to the hoisting winch 26 is connected to the load detector 42.

  The hoisting winch 26 changes the separation distance of the upper spreader 22 with respect to the lower spreader 20 by rotating the drum 26a and winding / unwinding the hoisting rope 28, thereby winding / lowering the boom 6; It is supposed to do ups and downs. When the hoisting winch 26 winds / unwinds the hoisting rope 28 for hoisting / lowering the boom 6, the hoisting rope 28 moves, and the sheaves 18, 20 a, 22 a are moved along with the movement of the hoisting rope 28. Each of the rotating shafts 18a, 20b, and 22b is rotated.

  The upper swing body 4 is provided with a cab 32 (see FIG. 1), and a undulation operating device 34 (see FIG. 3) for operating the undulation winch 26 is provided in the cab 32. Yes. The hoisting operation device 34 has a lever 34a operated by an operator. The lever 34a is on one side from the neutral position for instructing the hoisting and lowering operations of the hoisting winch 26 (stopping the rotation of the drum 26a), and the hoisting winch 26 hoisting the hoisting rope 28 A winding upper side for instructing a winding operation) and an unwinding side for instructing the lowering operation of the boom 6 by the hoisting winch 26 (the feeding operation of the hoisting rope 28) from the neutral position. It is possible. By operating the lever 34a from the neutral position to the hoisting side or the lowering side, an operation corresponding to the operation of the lever 34a is instructed to the hoisting winch 26. As a result, the hoisting winch 26 responds to the operation of the lever 34a. The hoisting operation or the lowering operation is performed.

  The load deriving device 40 according to the present embodiment is provided in the crane having the above-described configuration and derives the suspension load of the crane. The suspended load of the crane in the present embodiment includes the weight of the suspended load, the weight of the hook device (the main hook device 8 or the auxiliary hook device 9) that suspends the suspended load, and the hoisting rope for the hook device (main This corresponds to the total weight of the winding rope 10 or the auxiliary winding rope 11) and the weight of the portion hanging from the tip of the boom 6. Hereinafter, a specific configuration of the load deriving device 40 of the present embodiment will be described.

  As shown in FIG. 3, the load deriving device 40 according to this embodiment includes a load detector 42, an operation detector 44, a drum rotation detector 46, an angle detector 48, and a load calculation device 50.

  The load detector 42 is a load cell, for example, and is fixed to the upper swing body 4. As described above, the undulation rope 28 is connected to the load detector 42, and the load detector 42 sequentially detects the load applied to the undulation rope 28. Then, the load detector 42 sequentially outputs the detected load value data to the load calculation device 50.

  The operation detector 44 detects the operation state of the lever 34 a of the hoisting operation device 34. The operation detector 44 sequentially detects whether the lever 34a is in the neutral position or is operated from the neutral position to the winding side or the lowering side, and a signal representing the detected operation state of the lever 34a is detected by the load calculation device 50. Are output sequentially. The operation detector 44 is included in the concept of the direction output unit of the present invention, and the signal output from the operation detector 44 is included in the concept of the direction indicator signal of the present invention.

  Specifically, when the lever 34a is operated to the hoisting side, the hoisting winch 26 is hoisted, and the hoisting rope 28 is wound around the drum 26a to move to the side where the boom 6 is hoisted. . On the other hand, when the lever 34a is operated to the lowering side, the hoisting winch 26 is lowered, and the hoisting rope 28 is unwound from the drum 26a and moves to the lowering side of the boom 6. Therefore, when the output signal of the operation detector 44 represents the operation of the lever 34a on the winding side, the output signal becomes a movement direction indicator signal indicating the movement of the hoisting rope 28 to the winding side of the boom 6. Correspondingly, when the output signal of the operation detector 44 represents the operation of the lever 34a on the lowering side, the output signal indicates the moving direction indicating the movement of the hoisting rope 28 on the lowering side of the boom 6. Corresponds to the indicator signal.

  The drum rotation detector 46 is provided in the undulation winch 26, and detects the number of rotation pulses of the drum 26a output from the undulation winch 26. The drum rotation detector 46 sequentially detects the number of rotation pulses, and sequentially outputs data of the detected number of rotation pulses to the load calculation device 50. The drum rotation detector 46 is included in the concept of the movement amount output unit of the present invention, and the rotation pulse number data output from the drum rotation detector 46 is included in the concept of the movement amount index value of the present invention. It is included. Specifically, the number of rotation pulses of the drum 26a represents the amount of rotation of the drum 26a, and the amount of rotation of the drum 26a corresponds to the amount of movement of the hoisting rope 28 wound or fed by the drum 26a. Therefore, the rotation pulse number data output from the drum rotation detector 46 corresponds to a movement amount index value representing the movement amount of the hoisting rope 28 to the upper or lower side of the boom 6.

  The angle detector 48 detects the undulation angle of the boom 6. The angle detector 48 sequentially detects the undulation angle of the boom 6 and sequentially outputs the detected undulation angle data to the load calculation device 50.

  The load calculation device 50 derives the first tension value, which is the tension value of the hoisting rope 28, from the load value data output from the load detector 42, and the sheaves 18, 20a included in the derived first tension value. , 22a is corrected to reduce an error caused by the rotational resistance (friction force between the sheaves 18, 20a, 22a and the corresponding rotating shafts 18a, 20b, 22b), and the corrected first tension value The crane's suspension load is calculated from the second tension value. The load calculation device 50 corrects the first tension value by a correction coefficient corresponding to the operation direction of the lever 34a represented by the signal output from the operation detector 44, that is, the movement direction of the hoisting rope 28, and The increase correction in the direction to increase the first tension value and the decrease correction in the direction to decrease the first tension value in the transition period until the rotational resistance of the sheaves 18, 20a, 22a becomes constant at the time of winding and unwinding The correction coefficient is changed step by step so that the shift of the correction form between steps is performed step by step in accordance with the increase in the cumulative value of the rotation pulse number of the drum 26a (hereinafter referred to as the cumulative rotation pulse number). Hereinafter, a detailed configuration of the load calculation device 50 will be described.

  The load calculation device 50 includes a memory 52, a tension derivation unit 53 as a functional block, a correction value derivation unit 54, and a load calculation unit 56.

  The tension deriving unit 53 derives the first tension value of the hoisting rope 28 from the load value data output from the load detector 42 and input to the load calculation device 50. In the present embodiment, since the load detector 42 connected to the end of the hoisting rope 28 detects the load applied to the hoisting rope 28, the tension deriving unit 53 uses the load value output from the load detector 42 as it is. Derived as the first tension value of the rope 28.

  The memory 52 stores a correction coefficient for correcting the first tension value of the hoisting rope 28 derived by the tension deriving unit 53. This correction coefficient is included in the concept of the correction value of the present invention. The memory 52 stores different correction coefficients used for correcting the first tension value according to the operation direction of the lever 34a corresponding to the moving direction of the hoisting rope 28. Specifically, when the lever 34a is operated to the lowering side and the hoisting winch 26 performs the lowering operation of the boom 6, the correction coefficient for correcting the first tension value and the lever 34a are operated to the upper side. The correction coefficient for correcting the first tension value when the hoisting winch 26 performs the hoisting operation of the boom 6 is the cumulative rotation pulse number (rotation amount) of the drum 26a representing the movement amount of the hoisting rope 28, respectively. It is stored in a correlated state. For example, a function or map-like data indicating the correlation between the cumulative rotation pulse number at the time of winding and the correction coefficient, and a function or map-like data indicating the correlation between the cumulative rotation pulse number at the time of winding and the correction coefficient. Are stored in the memory 52.

  Of the correlation between the cumulative number of rotation pulses stored in the memory 52 and the correction coefficient, the portion corresponding to the transient period is in the direction of increasing the first correction value by multiplying the first tension value by the correction coefficient. The correction mode is shifted between the increase correction and the decrease correction in the direction of decreasing the first correction value by multiplying the first tension value by the correction coefficient, and the shift of the correction mode is increased by the cumulative number of rotation pulses. It is set to be performed step by step. Specifically, the correlation between the cumulative number of rotation pulses and the correction coefficient during the transition period during winding is changed in the middle of the transient period from the correction coefficient that causes an increase correction to the correction coefficient that causes a decrease correction. In addition, the change is set to be performed stepwise as the number of accumulated rotation pulses increases. Further, the correlation between the cumulative number of rotation pulses and the correction coefficient in the transition period at the time of winding is changed in the course of the transition period from the correction coefficient that causes the decrease correction to the correction coefficient that causes the increase correction, and The change is set to be performed stepwise as the cumulative number of rotation pulses increases.

  The memory 52 stores the correlation between the undulation angle of the boom 6 and its own weight component, and the load coefficient. The self-weight component is a load component other than the suspended load included in the tension (first tension value) of the hoisting rope 28. For example, when the suspended load is suspended by the main hook device 8, the sum of the weight of the boom 6 and the weight of the members other than the main hook device 8 that contribute to the tension of the hoisting rope 28 among the members attached to the boom 6. Is equivalent to its own weight component. Further, when the suspended load is suspended by the auxiliary hook device 9, the total of the weight of the boom 6 and the weight of the members other than the auxiliary hook device 9 that contribute to the tension of the hoisting rope 28 among the members attached to the boom 6. Is equivalent to its own weight component. Further, the memory 52 stores the cumulative rotation pulse number of the drum 26 a and the operation state of the lever 34 a detected by the operation detector 44 in the suspension load calculation process described later. In addition, the memory 52 stores the value of the correction coefficient used for correcting the tension value at each iteration of the suspended load calculation process.

  The correction value deriving unit 54 derives a correction coefficient used for correcting the first tension value. Specifically, the correction value deriving unit 54 derives a correction coefficient corresponding to the operation state of the lever 34 a represented by the signal output from the operation detector 44 based on the correction coefficient stored in the memory 52. The correction value deriving unit 54 derives the accumulated rotation pulse number by accumulating the rotation pulse number output from the drum rotation detector 46 during the transition period when the boom 6 is hoisted and lowered. A stepwise correction coefficient that changes with an increase in the number of rotation pulses is derived from the correlation between the accumulated number of rotation pulses stored in the memory 52 and the correction coefficient.

  The load calculation unit 56 corrects the first tension value by multiplying the first tension value derived by the tension deriving unit 53 by the correction coefficient derived by the correction value deriving unit 54. Further, the load calculation unit 56 outputs the self-weight component according to the data of the hoisting angle of the boom 6 output from the angle detector 48 and input to the load calculation device 50, and the undulation angle and the self-weight component stored in the memory 52. It is calculated based on the correlation. Then, the load calculation unit 56 uses the second tension value obtained by correcting the first tension value, the calculated self-weight component, and the load coefficient stored in the memory 52, to lift the crane. Is calculated. Specifically, the load calculation unit 56 subtracts the calculated weight component from the second tension value and multiplies the value obtained by the subtraction with a load coefficient to obtain the value of the suspended load. The load calculation unit 56 outputs the calculated suspension load value to the display device 60 provided in the cab 32 and causes the display device 60 to display the value.

  Next, a suspension load derivation process by the load derivation device 40 of this embodiment will be described with reference to the flowchart shown in FIG.

  First, the load calculation device 50 reads the operation state of the lever 34 a from the signal input from the operation detector 44, and the correction value deriving unit 54 reads the number of rotation pulses of the drum 26 a from the data input from the drum rotation detector 46. The tension deriving unit 53 reads the first tension value of the hoisting rope 28 from the load value data input from the load detector 42, and the load calculating unit 56 uses the hoisting angle of the boom 6 from the data input from the angle detector 48. Is read (step S1).

  Next, the load calculation device 50 determines whether or not the lever 34a is in the neutral position based on the read operation state of the lever 34a (step S2).

  When the load calculation device 50 determines that the lever 34a is in the neutral position, the load calculation unit 56 reads the correction coefficient used in the previous derivation process stored in the memory 52 (step S3). On the other hand, when the load calculation device 50 determines that the lever 34a is not in the neutral position, the load calculation device 50 next stores the memory 52 in the operation direction (winding up or down) from the neutral position of the lever 34a. It is determined whether or not it is the same as the operation direction (operation state) of the lever 34a in the previous derivation process stored in (Step S4).

  When the load calculating device 50 determines that the operation direction of the lever 34a is the same as the operation direction of the lever 34a in the previous derivation process, the correction value deriving unit 54 derives a correction coefficient (step) S5). At this time, the correction value deriving unit 54 derives the correction coefficient corresponding to the operation direction (winding up or down) of the lever 34a from the correction coefficient stored in the memory 52, and the number of rotation pulses read in step S1. Is added to the accumulated rotational pulse number stored in the memory 52, and the correction coefficient corresponding to the cumulative rotational pulse number after the addition is based on the correlation between the accumulated rotational pulse number stored in the memory 52 and the correction coefficient. To derive.

  On the other hand, when the load calculation device 50 determines in step S4 that the operation direction of the lever 34a is not the same as the previous operation direction of the lever 34a, the cumulative number of rotation pulses stored in the memory 52 is reset to zero. (Step S6) Then, the process of step S5 is performed.

  After the process of step S5, the load calculation unit 56 corrects the first tension value derived by the tension deriving unit 53 in step S1 (step S7). At this time, if it is determined in step S2 that the lever 34a is not in the neutral position, the load calculation unit 56 corrects the first tension value using the correction coefficient derived in step S5, while If it is determined in step S2 that the lever 34a is in the neutral position, the load calculation unit 56 corrects the first tension value using the correction coefficient read in step S3. Specifically, the load calculation unit 56 corrects the first tension value by multiplying the first tension value by a correction coefficient.

  Thereafter, the load calculation unit 56 derives the self-weight component corresponding to the undulation angle of the boom 6 read in step S1 based on the correlation between the undulation angle and the self-weight component stored in the memory 52, and the memory The load coefficient stored in 52 is read, and the suspended load value is calculated from the second tension value, which is the corrected first tension value, using the derived weight component and the read load coefficient (step S8).

  Finally, the new cumulative rotation pulse number, the operation state of the lever 34a in the current derivation process (neutral position, winding up or down), and the correction coefficient used in the current derivation process are stored in the memory 52. (Step S9). Specifically, the cumulative rotation pulse number stored in the memory 52 is updated to the cumulative pulse number after addition obtained by the correction value deriving unit 54 in step S5, and the operation state of the lever 34a stored in the memory 52 is updated. Is updated to the operation state read by the load calculation device 50 in step S1 of the current derivation process, and the correction coefficient used by the load calculation unit 56 for correcting the first tension value in step S7 of the current derivation process is stored in the memory. 52.

  The suspension load derivation process as described above is repeatedly performed, and the suspension load value calculated by the load calculation unit 56 is displayed on the display device 60.

  Next, an example of the correction of the first tension value when the suspension load is derived according to the present embodiment and the effect obtained by the correction will be described. In the following description, the value of the correction coefficient used for correcting the first tension value is an example, and is not limited to this value.

  In FIG. 5, after the lever 34a is operated from the neutral position to the lowering side to perform the lowering operation of the boom 6 by the hoisting winch 26, the lever 34a is returned to the neutral position and the lowering operation of the hoisting winch 26 is performed. Then, the lever 34a is operated from the neutral position to the hoisting side to cause the hoisting winch 26 to perform the hoisting operation of the boom 6, and then the lever 34a is returned to the neutral position and the hoisting winch 26 is hoisted. The first tension value of the hoisting rope 28, the theoretical value of the tension of the hoisting rope 28, the operating state of the lever 34a, and the change over time of the load display by the display device 60 when the hoisting winch 26 is operated in the procedure of stopping are shown. Yes. The theoretical value of the tension of the hoisting rope 28 means the tension value of the hoisting rope 28 when the rotational resistance of the sheaves 18, 20a, 22a is assumed to be zero, and the tension value corresponding to the actual suspension load. It is.

  In the present embodiment, when the lever 34a is initially in the neutral position (period before time t1), the first tension value is smaller than the theoretical value. At this time, the correction coefficient derivation unit 54 derives the correction coefficient 1.1, and the load calculation unit 56 multiplies the correction coefficient 1.1 by the first tension value to increase the first tension value to a value equal to the theoretical value. to correct.

  Thereafter, the lever 34a is operated to the lowering side at the time t1, but the tension of the hoisting rope 28 does not change immediately, and after a slight time lag, starts to change from the time t2. Until time t2, the correction value deriving unit 54 derives the same correction coefficient 1.1 as before time t1, and the load calculation unit 56 increases and corrects the first tension value to a value equal to the theoretical value as described above.

  After time t2, the boom 6 is lowered by the hoisting winch 26, and the first tension value gradually increases. During the period from time t2 to time t3, the rotation of the sheaves 18, 20a, 22a is not stable, and the direction in which the rotational resistance acts changes from the upper side to the lower side, and the magnitude of the rotational resistance changes. It is a transition period. In this transient period, the correction value deriving unit 54 causes the correction coefficient to gradually decrease from 1.1 to 0.9 as the cumulative number of rotation pulses (rotation amount) of the drum 26a representing the movement amount of the hoisting rope 28 increases. The load calculation unit 56 multiplies the first tension value by the derived correction coefficient to correct the first tension value to a value equal to the theoretical value. As a result, the correction mode shifts from the increase correction to the decrease correction in the middle of the transition period, and the shift is performed stepwise as the cumulative number of rotation pulses increases. During the transition period, the first tension value gradually changes from a smaller value than the theoretical value to a larger value than the theoretical value due to a change in the rotational resistance of the sheaves 18, 20a, 22a. Due to the stepwise transition to, appropriate correction corresponding to the change in the first tension value can be performed, and errors in the first tension value can be appropriately eliminated.

  After the transition period elapses, the rotation of the sheaves 18, 20a, and 22a is stable and the rotation resistance is constant during the period until the lowering is stopped (period from time t3 to t4). During this period, the correction value deriving unit 54 derives a constant correction coefficient 0.9, and the load calculation unit 56 multiplies the derived correction coefficient 0.9 by the first tension value to calculate the first tension value. Correct the decrease to a value equal to the value.

  When the lever 34a is returned to the neutral position at time t4, the lowering operation of the hoisting winch 26 is stopped, and the increase in the first tension value is stopped. During the period in which the lever 34a is disposed at the neutral position (period from time t4 to t5), the first tension value is a constant value larger than the theoretical value, and the correction value deriving unit 54 performs the time from time t3 to time in this period. The same correction coefficient 0.9 as that in the period up to t4 is derived. The load calculation unit 56 multiplies the derived correction coefficient 0.9 by the first tension value to reduce and correct the first tension value to a value equal to the theoretical value.

  Thereafter, at time t5, the lever 34a is operated to the winding side, but the tension of the hoisting rope 28 does not change immediately, and after a slight time lag, starts to change from time t6. During this time lag (period from time t5 to t6), the correction coefficient derivation unit 54 derives the same correction coefficient 0.9 as the period during which the lever 34a is in the neutral position (period from time t4 to t5), and calculates the load. The unit 56 multiplies the first tension value by the correction coefficient 0.9 to reduce the first tension value to a value equal to the theoretical value.

  Then, after time t6, the boom 6 is wound up by the hoisting winch 26, and the first tension value gradually decreases. During the period from time t6 to time t7, the rotation of the sheaves 18, 20a, 22a is not stable, the direction in which the rotational resistance acts changes from the lower side to the upper side and the magnitude of the rotational resistance changes. It is a transition period. In this transition period, the correction coefficient is derived from the correction value deriving unit 54 gradually from 0.9 to 1.1 as the cumulative number of rotation pulses (rotation amount) of the drum 26a representing the movement amount of the hoisting rope 28 increases. The load calculation unit 56 multiplies the first tension value by the derived correction coefficient to correct the first tension value to a value equal to the theoretical value. As a result, the correction mode shifts from the decrease correction to the increase correction in the middle of the transient period, and the shift is performed stepwise as the cumulative number of rotation pulses increases. During the transition period, the first tension value changes from a value larger than the theoretical value to a value smaller than the theoretical value due to a change in the rotational resistance of the sheaves 18, 20a, 22a. By the stepwise transition, appropriate correction corresponding to the change in the first tension value can be performed, and the error in the first tension value can be appropriately eliminated.

  After the transition period elapses, the rotation of the sheaves 18, 20a, and 22a is stable and the rotation resistance is constant during the period until the hoisting is stopped (period from time t7 to t8). During this period, the correction value deriving unit 54 derives a constant correction coefficient 1.1, and the load calculation unit 56 multiplies the derived correction coefficient 1.1 by the first tension value to calculate the first tension value. Increase correction to a value equal to the value.

  When the lever 34a is returned to the neutral position at time t8, the hoisting operation of the hoisting winch 26 is stopped, and the decrease in the first tension value is stopped. During the period in which the lever 34a is disposed at the neutral position (period after time t8), the first tension value is a constant value smaller than the theoretical value, and the correction value deriving unit 54 performs the time from time t7 to time t8 during this period. The same correction coefficient 1.1 as in the previous period is derived. The load calculation unit 56 multiplies the derived correction coefficient 1.1 by the first tension value to increase and correct the first tension value to a value equal to the theoretical value.

  As described above, since the first tension value is corrected to a value equal to the theoretical value over the entire period, the load calculation unit 56 calculates from the second tension value, which is the corrected first tension value, on the display device 60. The displayed suspension load value is a constant value with no error with respect to the actual suspension load over the entire period.

  FIG. 6 shows a view corresponding to FIG. 5 when the suspension load is calculated from the first tension value that is not corrected at all and displayed on the display device. In addition, FIG. 7 shows that at the moment when the lever of the hoisting operation device is operated from the neutral position to the lowering side, the correction mode is switched from the increase correction to the decrease correction by a constant correction coefficient corresponding to the lowering, and the lever is neutral. FIG. 5 is a diagram corresponding to FIG. 5 when the correction mode is switched from the decrease correction to the increase correction with a constant correction coefficient corresponding to the winding at the moment when the operation is performed from the position to the winding upper side. Further, FIG. 8 shows that the correction form is changed according to a constant correction coefficient corresponding to the increase correction to the lowering at the moment when the first tension value changes after the lever of the hoisting operation device is operated from the neutral position to the lowering side. FIG. 5 is a diagram in the case of switching to decrease correction and switching the correction mode from decrease correction to increase correction with a constant correction coefficient corresponding to winding at the moment when the first tension value changes after the lever is operated from the neutral position to the winding side. A 5-equivalent diagram is shown.

  When the suspension load is calculated and displayed from the first tension value that is not corrected at all, as shown in FIG. 6, the suspension load value having an error with respect to the actual suspension load is displayed in almost the entire period. The suspended load value displayed in the transition period during winding (period from time t2 to t3) and in the transition period during winding (period from time t6 to t7) varies.

  Further, when the correction mode is switched to the correction mode corresponding to the lever operation side at the moment of lever operation, the load display is actually displayed at the moment of lever operation (time t1 and time t5) as can be seen from FIG. Suspended load value that has an error with respect to the actual suspended load is displayed during the period until the end of the transition period (period from time t1 to t3 and period from time t5 to t7). Is done.

  Further, when the correction mode is switched to the correction mode corresponding to the operation side of the lever at the moment when the first tension value changes after the operation of the lever, as can be seen from FIG. 8, the moment of the change of the first tension value. The load display suddenly changes to a value far from the actual suspension load at (time t2 and time t6), and the actual suspension load during the subsequent transient period (periods t2 to t3 and periods t6 to t7). A suspended load value having an error is displayed.

  On the other hand, in the present embodiment, as described above, since the transition of the stepwise correction mode is performed in the transition period, there is no error with respect to the actual suspension load in the period until the transition period ends after the lever operation. The suspended load value is calculated and displayed, and the suspended load value with no error is calculated and displayed for other periods.

  As described above, in the present embodiment, the load calculation unit 56 of the load calculation device 50 performs the increase correction in the direction in which the first tension value of the hoisting rope 28 is increased during the transition period during winding and unwinding. The shift of the correction mode between the decrease correction in the direction of decreasing the first tension value of the hoisting rope 28 is performed stepwise in accordance with the increase in the cumulative number of rotation pulses of the drum 26a representing the movement amount of the hoisting rope 28. Since the first tension value is corrected with a correction coefficient that changes with time, it is possible to prevent a portion where the value suddenly changes in the corrected first tension value due to the correction of the first tension value during the transition period. . For this reason, it is possible to prevent a portion where the value suddenly changes in the suspended load calculated from the second tension value which is the first tension value after correction, and based on the calculated suspended load value, Load display that does not give the operator a sense of incongruity can be realized.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, the present invention is not necessarily applied only to the load derivation device that derives the suspension load from the first tension value of the hoisting rope, but the suspension load is derived from the first tension value of the hoisting rope connected to the hook device. The present invention can also be applied to a load deriving device.

  FIGS. 9-11 is a figure for demonstrating the structure of the load derivation | leading-out apparatus 40 by which the suspension load is derived | led-out from the 1st tension value of the main winding rope 10 which is an example of a hoisting rope by the modification of this invention. . The suspended load in this modification is the weight of the suspended load, the weight of the main hook device 8 that suspends the suspended load, and the weight of the portion of the main winding rope 10 that is suspended from the tip of the boom 6. Equivalent to the total weight.

  The main hook device 8 which is an object to be rolled up and down includes a plurality of hook sheaves 8a (see FIG. 9), and the plurality of hook sheaves 8a are rotatable around the axis by a rotating shaft 8b. It is supported. A plurality of boom point sheaves 62 and a boom top sheave 64 are provided at the tip of the boom 6. The plurality of boom point sheaves 62 are supported so as to be rotatable by a rotating shaft 62a, and the boom top sheave 64 is supported so as to be rotatable by a corresponding rotating shaft (not shown).

  The main winding rope 10 drawn from the drum 12a of the main winding winch 12 provided on the upper swing body 4 (see FIG. 1) is hung on a boom top sheave 64 and then a plurality of booms as shown in FIG. It is wound around the point sheave 62 and the plurality of hook sheaves 8a. Further, the main winding rope 10 is hung at the position between the boom top sheave 64 and the boom point sheave 62 at the tip of the boom 6, and a load detector 66 for detecting the load applied to the main winding rope 10 is provided. It has been. The load detector 66 detects a load F ′ (see FIG. 10) that acts downward on the load detector 66 from the main winding rope 10 due to the load applied to the main winding rope 10. The tension deriving unit 53 of the load calculation device 50 calculates the first tension value F of the main winding rope 10 from the load value F ′ detected by the load detector 66 according to the following equation (1).

F = 2 × cos θ × F ′ (1)
In the cab 32 (see FIG. 1), a hoisting operation device 70 (see FIG. 11) for operating the main winding winch 12 is provided. The lever 70a of the hoisting operation device 70 is used for hoisting the main hook device 8 by the main hoisting winch 12 from a neutral position instructing to stop the hoisting operation and the lowering operation of the main winding winch 12 (stopping the rotation of the drum 12a). Winding upper side for instructing (winding operation of the main winding rope 10) and lowering operation of the main hook device 8 by the main winding winch 12 on the side opposite to the winding upper side from the neutral position (feeding operation of the main winding rope 10) It can be operated on the lower side to instruct.

  The operation detector 44 sequentially detects whether the lever 70a is in the neutral position or is operated from the neutral position to the winding side or the lowering side, and a signal representing the detected operation state of the lever 70a is detected by the load calculation device 50. Are output sequentially. The signal output from the operation detector 44 is included in the concept of a direction indicator signal indicating the moving direction of the main winding rope 10.

  The drum rotation detector 46 sequentially detects the number of rotation pulses of the drum 12 a output from the main winding winch 12 and sequentially outputs data of the detected number of rotation pulses to the load calculation device 50. The number of rotation pulses output from the drum rotation detector 46 is included in the concept of a movement amount index value representing the movement amount of the main winding rope 10.

  The load calculation device 50 corrects the first tension value of the main winding rope 10 by a correction coefficient corresponding to the operation direction of the lever 70a represented by the signal output from the operation detector 44, that is, the moving direction of the main winding rope 10. In the transition period until the rotational resistance of the sheaves 64, 62, 8a becomes constant when the main hook device 8 is rolled up and down, the increase correction in the direction to increase the first tension value of the main winding rope 10 and the first The correction coefficient is changed stepwise so that the shift of the correction mode between the decrease correction in the direction of decreasing the one tension value is performed stepwise in accordance with the increase in the cumulative number of rotation pulses of the drum 12a.

  The memory 52 also includes a correction coefficient for correcting the first tension value of the main rope 10 when the main hook device 8 is wound, and the first coefficient of the main rope 10 when the main hook device 8 is lowered. The correction coefficient for correcting the tension value is stored in a state associated with the cumulative number of rotation pulses (rotation amount) of the drum 12a representing the movement amount of the main winding rope 10. This correction coefficient is included in the concept of the correction value of the present invention.

  Further, in the correlation between the cumulative number of rotation pulses stored in the memory 52 and the correction coefficient of the first tension value of the main winding rope 10, the part corresponding to the transient period is multiplied by the correction coefficient. The correction mode is shifted between an increase correction in the direction of increasing the first correction value and a decrease correction in the direction of decreasing the first correction value by multiplying the first tension value by the correction coefficient, and The correction mode is set so as to be performed step by step as the number of transition accumulated rotation pulses increases. Specifically, the correlation between the cumulative number of rotation pulses and the correction coefficient of the main winding rope 10 in the transition period at the time of lowering is the transition period from the correction coefficient that causes the correction coefficient to perform decrease correction to the correction coefficient that causes increase correction. And the change is set to be performed step by step as the number of accumulated rotation pulses increases. Further, the correlation between the cumulative number of rotation pulses and the correction coefficient in the transition period at the time of winding is changed in the middle of the transition period from the correction coefficient that causes the increase correction to the correction coefficient that causes the decrease correction, and The change is set to be performed stepwise as the cumulative number of rotation pulses increases.

  The function of the correction value deriving unit 54 in this modification is basically the same as the function of the correction value deriving unit 54 of the above embodiment, and corresponds to the operation state of the lever 70a represented by the signal output from the operation detector 44. The correction coefficient is derived, and stepwise according to the cumulative value (cumulative rotational pulse number) of the rotational pulse number output from the drum rotation detector 46 during the transitional period when the main hook device 8 is wound up and down. A correct correction factor is derived.

  In addition, the load calculation unit 56 in this modification corrects the first tension value of the main winding rope 10 derived by the tension deriving unit 53 with the correction coefficient derived by the correction value deriving unit 54, and the corrected second value. The crane's suspension load is determined from the second tension value, which is the first tension value. Specifically, the load calculation unit 56 derives the second tension value as it is as the crane load value. The other functions of the load calculation unit 56 in this modification are the same as the functions of the load calculation unit 56 of the above embodiment.

  FIG. 12 shows how the first tension value of the main rope 10 is corrected when the lever operation similar to the series of lever operations of the above embodiment shown in FIG. The time-dependent change of the value of the suspended load displayed on is shown.

  The theoretical value of the tension of the main winding rope 10 becomes a constant value over the entire period of a series of lever operations. On the other hand, the first tension value of the main winding rope 10 derived by the tension deriving unit 53 has an error from the theoretical value due to the rotational resistance of the sheaves 64, 62, 8a.

  Specifically, during a period in which the lever 70a is in the neutral position for the first time (period before time t1) and after that, a predetermined time lag period (period from time t1 to t2) after the lever 70a is operated to the lowering side. The first tension value of the main winding rope 10 is a constant value larger than the theoretical value. In the transition period (period from time t2 to t3) when the main hook device 8 is unwound, the first tension value of the main winding rope 10 is larger than the theoretical value due to the change in rotational resistance of the sheaves 64, 62, 8a. It gradually changes from a value to a value smaller than the theoretical value. In the period after the transition period at the time of unwinding (period from time t3 to t4), the first tension value of the main rope 10 becomes a constant value smaller than the theoretical value, and then the lever 70a is disposed in the neutral position. The same period (period from time t4 to t5) is also set.

  Thereafter, during a predetermined time lag period (time t5 to t6) after the lever 70a is operated to the winding side, the first tension value of the main winding rope 10 is such that the previous lever 70a is disposed at the neutral position. It becomes a constant value similar to the period. During the transition period (period from time t6 to t7) when the main hook device 8 is wound, the first tension value of the main winding rope 10 is smaller than the theoretical value due to the change in the rotational resistance of the sheaves 64, 62, 8a. It gradually changes from a value to a value larger than the theoretical value. In the period after the transition period at the time of winding (period from time t7 to t8), the first tension value of the main winding rope 10 becomes a constant value larger than the theoretical value, and then the lever 70a is disposed at the neutral position. The same period (period after time t8) is the same constant value.

  The correction value deriving unit 54 derives a correction coefficient capable of appropriately correcting an error with respect to the theoretical value of the first tension value of the main winding rope 10 in each period by a method similar to the method in the above embodiment. In particular, during the transition period during winding (the period from time t2 to t3), the correction value deriving unit 54 shifts the correction mode from a decrease correction to an increase correction in a stepwise manner in accordance with an increase in the cumulative number of rotation pulses of the drum 12a. For this reason, the correction value deriving unit 54 accumulates the correction form from the increase correction to the decrease correction in the accumulation of the drum 12a in the transition period (period from time t6 to t7) during winding. A correction coefficient that changes stepwise to shift stepwise as the number of rotation pulses increases is derived. The load calculation unit 56 multiplies the first tension value of the main winding rope 10 by the correction coefficient derived by the correction value deriving unit 54, so that the first tension value of the main winding rope 10 in each period is equal to the theoretical value. The value is corrected to a value, and the crane's suspension load is calculated from the second tension value, which is the first tension value after the correction. As a result, the value of the suspension load calculated by the load calculation unit 56 and displayed on the display device 60 is a constant value with no error with respect to the actual suspension load over the entire period, and a load display without a sense of incongruity is realized. .

  In the configuration not described above in this modified example, the configuration related to the boom 6, the hoisting rope 28 and the hoisting winch 26 in the above embodiment relates to the main hook device 8, the main winding rope 10 and the main winding winch 12 of the modified example. Applied by replacing the configuration.

  Further, a configuration similar to the configuration of the above modification may be applied to a load deriving device that derives the suspended load from the first tension value of the auxiliary winding rope 11 connected to the auxiliary hook device 9. The suspended load in this case is the weight of the suspended load, the weight of the auxiliary hook device 9 that suspends the suspended load, and the weight of the portion of the auxiliary winding rope 11 that is suspended from the tip of the boom 6. It corresponds to the total weight.

  Further, the memory 52 of the load calculating device 50 has a plurality of patterns of correlations indicating the correlation between the cumulative number of rotation pulses of the drum 26a and the correction coefficient during the transition period that is different for each form of sheave around which the hoisting rope 28 is wound. May be stored. Then, the correction value deriving unit 54 of the load calculation device 50 corresponds to the shape of the sheave on which the undulation rope 28 is currently wound from the correlation of the plurality of patterns stored in the memory 52 in order to derive the correction coefficient. A correlation may be selected and used.

  According to this configuration, the correction coefficient derived by the correction value deriving unit 54 appropriately corrects the error in the first tension value of the undulation rope during the transition period according to the shape of the sheave on which the undulation rope 28 is currently wound. can do. Note that the form of the sheave means the number, type, shape, arrangement, and the like of the sheave around which the hoisting rope 28 is hung. In addition, a configuration similar to this configuration is applied to derivation of a correction coefficient for correcting the first tension value of the main winding rope 10 in the transition period when the suspension load is derived from the first tension value of the main winding rope 10. May be. In addition, the same configuration may be applied to derivation of a correction coefficient for correcting the first tension value of the auxiliary winding rope 11 during the transition period when the suspension load is derived from the first tension value of the auxiliary winding rope 11. .

  Further, as the direction output unit of the present invention, instead of an operation detector that detects the operation state of the lever and outputs a signal indicating the operation state, the actual movement of the rope is detected and the movement direction of the rope is indicated. A movement direction detector that outputs a signal may be used, and a signal output from the movement direction detector may be used as the direction indicator signal of the present invention.

  Further, as the movement amount output unit of the present invention, instead of the drum rotation detector that detects the number of rotation pulses of the drum and outputs the data of the detected number of rotation pulses, the actual movement amount of the rope is detected. A movement amount detector that outputs movement amount data may be used, and data output by the movement amount detector may be used as the movement amount index value of the present invention.

  Further, the method by which the load calculation unit corrects the first tension value is not necessarily limited to the method of multiplying the first tension value by the correction coefficient. For example, the correction value deriving unit derives a correction value corresponding to the difference between the first tension value and the theoretical value, and the load calculation unit adds the correction value derived by the correction value deriving unit to the first tension value. Alternatively, the first tension value may be corrected by subtracting from the first tension value. In this case, the correlation between the direction index value indicating the movement direction of the rope and the movement amount index value indicating the movement amount of the rope and the error of the first tension value with respect to the theoretical value is examined in advance. The correlation between the direction index value and the movement amount index value and the correction value corresponding to the error of the first tension value may be set and stored in the memory. The correction value deriving unit may derive a correction value according to the current rope movement direction and movement amount based on the correlation stored in the memory.

  Further, the load deriving device of the present invention is not necessarily applied only to the type of crane shown in FIG. 1, but can be applied to other various cranes. Further, the hoisting member of the present invention is not limited to the type of boom (lattice boom) shown in FIG. 1, and may be another type of boom, or a jib connected to the tip of the boom. Also good.

6 Boom (object, hoisting member)
8 Main hook device (object)
8a Hook sheave 9 Supplementary hook device (object)
10 Main winding rope 11 Supplementary winding rope 12 Main winding winch (winding winch)
13 Supplementary winch (winding winch)
18 gantry peak sheave 20a lower sheave 22a upper sheave 26 hoisting winch 28 hoisting rope 40 load deriving device 42, 66 load detector 44 operation detector (direction output unit)
46 Drum rotation detector (movement amount output unit)
50 Load calculation device 62 Boom point sheave 64 Boom top sheave

Claims (6)

A crane that has a winch that winds and unwinds an object through the rope by rotating a drum around which a rope wound around a sheave is wound, and that performs a lifting work by winding and unwinding the object A load deriving device for deriving the suspended load of the crane,
A load detector for detecting a load applied to the rope;
A direction output unit that outputs a direction indicator signal indicating the moving direction of the rope to the upper or lower side of the object;
A movement amount output unit that outputs a movement amount index value representing a movement amount of the rope to the upper or lower side of the object;
Deriving the first tension value of the rope from the load value detected by the load detector, performing a correction to reduce an error caused by the rotational resistance of the sheave included in the derived first tension value; A load calculation device for obtaining the suspension load from the second tension value, which is the first tension value after the correction,
The movement amount output unit detects the amount of rotation of the drum corresponding to the amount of movement of the rope to the upper or lower side of the object and uses the detected rotation amount data as the movement amount index value. Drum rotation detector to output,
The load calculating device corrects the first tension value by a correction value corresponding to the moving direction of the rope represented by the direction indicator signal, and the rotational resistance of the sheave at the time of winding and unwinding of the object. The transition of the correction mode between the increase correction in the direction in which the first tension value is increased and the decrease correction in the direction in which the first tension value is decreased is output from the drum rotation detector in the transition period until it becomes constant. A crane load deriving device that changes the correction value stepwise so as to perform stepwise according to an increase in the amount of rotation of the drum as the movement amount index value.   A winch that winds and lowers an object through a rope hung around a sheave is provided in a crane that performs a lifting operation by winding and lowering the object, and derives the crane's lifting load A load deriving device,
  A load detector for detecting a load applied to the rope;
  A direction output unit that outputs a direction indicator signal indicating the moving direction of the rope to the upper or lower side of the object;
  A movement amount output unit that outputs a movement amount index value representing a movement amount of the rope to the upper or lower side of the object;
  Deriving the first tension value of the rope from the load value detected by the load detector, performing a correction to reduce an error caused by the rotational resistance of the sheave included in the derived first tension value; A load calculation device for obtaining the suspension load from the second tension value, which is the first tension value after the correction,
  The movement amount output unit detects an actual movement amount of the rope to the upper or lower side of the object and outputs data of the detected actual movement amount of the rope as the movement amount index value. A travel detector,
  The load calculating device corrects the first tension value by a correction value corresponding to the moving direction of the rope represented by the direction indicator signal, and the rotational resistance of the sheave at the time of winding and unwinding of the object. The movement amount detector outputs a shift of the correction mode between the increase correction in the direction in which the first tension value is increased and the decrease correction in the direction in which the first tension value is decreased in the transition period until it becomes constant. A crane load deriving device that changes the correction value stepwise so as to perform stepwise according to an increase in the actual movement amount of the rope as the movement amount index value. The load calculation device has a plurality of movement amount correction value correlations indicating a correlation between the movement amount index value and the correction value in the transition period that is different for each form of the sheave around which the rope is wound. The movement amount correction value correlation corresponding to the shape of the sheave on which the rope is currently wound is selected from the movement amount correction value correlation of the plurality of patterns, and the selected movement amount correction is selected. wherein deriving a correction value for correcting the first tension value of the transition period using the value correlation, the load deriving apparatus for a crane according to claim 1 or 2. The crane load deriving device according to claim 3 , wherein the shape of the sheave is the number of sheaves around which the rope is wound. The object is a hoisting member provided so as to be hoistable in the crane,
The crane load derivation device according to any one of claims 1 to 4 , wherein the winch is a hoisting winch that winds and lowers the hoisting member via the rope. The object is a hook device for hanging a suspended load,
The crane load deriving device according to any one of claims 1 to 4 , wherein the winch is a hoisting winch that winds and lowers the hook device via the rope.

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