Crane rotation control device and crane equipped with same

Abstract

To prevent an attachment from being damaged and broken by applying a large lateral load to the attachment due to revolving operation of an upper revolving superstructure.SOLUTION: A revolving control device 8S includes an attachment information acquisition unit 800A, an angular velocity setting unit 801, and a revolving control unit 802. The attachment information acquisition unit 800A acquires attachment information for setting a maximum revolving angular velocity based on a lateral load acting on an attachment 10S. The angular velocity setting unit 801 sets a maximum revolving angular velocity of an upper revolving superstructure 12 based on the attachment information. The revolving control unit 802 controls a revolving driving unit 7S such that the revolving angular velocity of the upper revolving superstructure 12 does not exceed the maximum revolving angular velocity set by the angular velocity setting unit 801.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a crane swing control device and a crane equipped with the same. [Background technology]

[0002] Conventionally, a mobile crane has been known that includes a lower body, a rotating upper body, and an attachment such as a boom or a jib. The attachment is attached to the front of the rotating upper body so that it can be raised and lowered. When a load is connected to a lifting rope hanging from the tip of the attachment, the load can be lifted. In addition, with such a crane, the rotating upper body may be rotated while the load is lifted.

[0003] Patent Document 1 discloses a crane in which multiple attachments, including a boom, fixed jib, luffing jib, etc., can be selectively attached to and detached from a rotating upper structure, and the crane is equipped with an automatic work mode discrimination device. The automatic discrimination device includes a means for detecting the type and attachment status of the attachment, a work mode detection device that determines the crane's work mode based on a detection signal input from the detection means, a mode setting switch that accepts the work mode input by the operator, a mode comparison management device that determines whether the work mode determined by the work mode detection device matches or does not match the work mode input from the mode setting switch, and a mode indicator light that notifies whether the two work modes match or do not match. The operator can safely perform work after confirming from the mode indicator light that the appropriate attachment corresponding to the input work mode is attached to the rotating upper structure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 2971388 Summary of the Invention [Problem to be solved by the invention]

[0005] With the crane described in Patent Document 1, while an operator can recognize that an appropriate attachment is attached to the upper rotating body, it is unclear at what rotation angular velocity the attached attachment can perform a rotation operation, which results in the operator performing the rotation operation at an excessively large rotation angular velocity, which could result in part of the attachment being broken or damaged, or the operator could be overly concerned about such attachment damage and end up overly restricting the rotation angular velocity, which could result in a deterioration of workability.

[0006] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a crane rotation control device that can efficiently prevent a large lateral load from being applied to an attachment due to the rotation of the upper rotating body based on the operator's rotation operation, which would cause the attachment to be damaged or broken, and a crane equipped with the same. [Means for solving the problem]

[0007] A crane slewing control device according to one aspect of the present invention is used in a crane having a lower body, an upper rotating body supported on the lower body so as to be rotatable about a rotation center axis extending in the vertical direction relative to the lower body, an operation unit that receives an operation to rotate the upper rotating body relative to the lower body and outputs a rotation command signal corresponding to the magnitude of the operation, a rotation drive unit that can rotate the upper rotating body relative to the lower body, an attachment that is detachable from the upper rotating body and includes a base end supported on the upper rotating body so as to be rotatable in the hoisting direction and a tip end opposite the base end, and a load rope that hangs down from the tip end of the attachment and is connected to a suspended load. The crane slewing control device includes an attachment information acquisition unit, an angular velocity setting unit, and a slewing control unit. The attachment information acquisition unit acquires attachment information. The attachment information is information specific to the attachment for setting a maximum swing angular velocity, which is a maximum value of the swing angular velocity, based on a lateral load, which is a load along the swing direction of the upper rotating body that acts on the attachment due to the swing angular velocity of the upper rotating body. The angular velocity setting unit sets the maximum swing angular velocity allowed in the swing operation of the upper rotating body based at least on the attachment information acquired by the attachment information acquisition unit. The swing control unit receives the swing command signal output from the operation unit and controls the swing drive unit so that the upper rotating body swings relative to the lower main body in response to the swing command signal, and controls the swing drive unit so that the swing angular velocity of the upper rotating body does not exceed the maximum swing angular velocity set by the angular velocity setting unit.

[0008] According to this configuration, the attachment information is information for setting the maximum rotation angular velocity, which is the maximum value of the rotation angular velocity, based on the lateral load, and the angular velocity setting unit can set the maximum rotation angular velocity for the rotation operation of the upper rotating body according to the attachment information.This makes it possible to efficiently prevent the attachment from being damaged or broken due to a large lateral load being applied to the attachment based on the worker's rotation operation.

[0009] In the above configuration, it is desirable that the attachment information includes the length of the attachment from the base end to the tip end, and that the angular velocity setting unit sets the maximum turning angular velocity so that the maximum turning angular velocity decreases as the length of the attachment increases.

[0010] According to this configuration, when a relatively long attachment is attached to the upper rotating body, the angular velocity setting unit sets the maximum rotation angular velocity of the upper rotating body to a relatively small value, thereby reliably preventing a large lateral load from being applied to the attachment, which would otherwise cause damage or breakage to the attachment.

[0011] In the above configuration, it is desirable that the device further includes a turning information acquisition unit that acquires turning information, the turning information being information related to the conditions of the turning operation for setting the maximum turning angular velocity, and the angular velocity setting unit sets the maximum turning angular velocity based on the attachment information acquired by the attachment information acquisition unit and the turning information acquired by the turning information acquisition unit.

[0012] According to this configuration, the angular velocity setting unit sets the maximum rotation angular velocity based on rotation information during the crane's rotation operation in addition to attachment information specific to the attachment, which further prevents a large lateral load from being applied to the attachment, causing damage or breakage to the attachment.

[0013] In the above configuration, it is desirable that the rotation information includes information corresponding to the suspended load, which is the load of the suspended load connected to the suspension rope, and that the angular velocity setting unit sets the maximum rotation angular velocity based on at least the attachment information acquired by the attachment information acquisition unit and the suspended load load acquired by the rotation information acquisition unit.

[0014] According to this configuration, the angular velocity setting unit sets the maximum rotation angular velocity based on the load of the suspended load, which can have a significant impact on the lateral load acting on the attachment, in addition to the attachment information, so that an appropriate maximum rotation angular velocity can be set according to the load actually lifted.

[0015] In the above configuration, it is desirable that the angular velocity setting unit sets the maximum rotation angular velocity so that the maximum rotation angular velocity decreases as the suspended load increases for the same attachment information.

[0016] According to this configuration, when a relatively large load is connected to the attachment, the angular velocity setting unit sets the maximum rotation angular velocity of the upper rotating body to a relatively small value, thereby reliably preventing a large lateral load from being applied to the attachment, which would otherwise cause damage or breakage to the attachment.

[0017] In the above configuration, it is desirable that the device further includes a load detection unit capable of detecting the load of the suspended load, and that the angular velocity setting unit sets the maximum rotation angular velocity based on the load of the suspended load detected by the load detection unit during the period after the suspended load has moved upward from the ground and before the rotation drive unit rotates the upper rotating body in response to the operation input to the operating unit.

[0018] With this configuration, the maximum rotation angular velocity can be set without being affected by fluctuations in the load detection value due to attachment sway or wind during rotation, thereby enabling stable control of the rotation operation of the upper rotating body.

[0019] In the above configuration, it is desirable that the rotation information acquired by the rotation information acquisition unit includes information regarding a maximum suspended load, which is a predetermined maximum load of the suspended load connected to the suspension rope, and that the angular velocity setting unit sets the maximum rotation angular velocity based on the attachment information acquired by the attachment information acquisition unit and the maximum suspended load.

[0020] According to this configuration, when the upper rotating body is rotating, the maximum rotation angular velocity can be set without the need to detect and reflect the current suspended load.

[0021] In the above configuration, the rotation information includes information regarding the posture of the attachment, and the angular velocity setting unit sets the maximum rotation angular velocity based on the ratio of the suspended load to the rated load determined from the attachment information acquired by the attachment information acquisition unit and the posture of the attachment acquired by the rotation information acquisition unit, and it is desirable that the rated load is set corresponding to the maximum number of suspended pieces of the load rope hanging down from the tip of the attachment.

[0022] According to this configuration, the maximum rotation angular velocity is set using the ratio of the suspended load to the rated load, which is determined from the capacity of the attachment, thereby making it possible to achieve both safety and workability of the crane.

[0023] In the above configuration, it is preferable that the angular velocity setting unit sets the maximum swing angular velocity when the swing operation of the upper swing body starts, and maintains the set maximum swing angular velocity during the swing operation.

[0024] According to this configuration, the maximum rotation angular velocity does not change during the rotation operation, so that it is possible to prevent a decrease in operability for the operator due to frequent sudden changes in the angular velocity of the upper rotating body.

[0025] In the above configuration, it is desirable that the angular velocity setting unit updates the maximum rotation angular velocity at predetermined intervals during the rotation operation of the upper rotating body, and the rotation control unit controls the rotation drive unit so that the rotation angular velocity of the upper rotating body does not exceed the maximum rotation angular velocity updated by the angular velocity setting unit.

[0026] According to this configuration, the maximum turning angular velocity is updated in accordance with changes in turning information during a turning operation, thereby improving workability while ensuring safety.

[0027] In the above configuration, it is desirable that the turning information acquired by the turning information acquisition unit includes information regarding the working radius, which is the distance from the base end to the tip end of the attachment in a planar view, and that the angular velocity setting unit sets the maximum turning angular velocity based on at least the attachment information acquired by the attachment information acquisition unit and the working radius acquired by the turning information acquisition unit.

[0028] According to this configuration, the angular velocity setting unit sets the maximum turning angular velocity based on the working radius, which can have a significant impact on the lateral load acting on the attachment, in addition to the attachment information, thereby reliably preventing a large lateral load from being applied to the attachment.

[0029] In the above configuration, it is desirable that the angular velocity setting unit sets the maximum turning angular velocity so that the larger the working radius is, the smaller the maximum turning angular velocity is, for the same attachment information.

[0030] According to this configuration, when the attachment is set to a relatively large working radius, the angular velocity setting unit sets the maximum rotation angular velocity of the upper rotating body to a relatively small value, thereby reliably preventing a large lateral load from being applied to the attachment, which would otherwise cause damage or breakage to the attachment.

[0031] In the above configuration, it is desirable that the attachment includes a boom including the base end portion and supported on the upper rotating body so as to be rotatable in the boom hoisting direction, and a jib including the tip end and supported on the boom so as to be rotatable in the boom hoisting direction, the rotation information further includes information related to the boom hoisting angle and the jib hoisting angle, and the angular velocity setting unit sets the maximum rotation angular velocity based on at least the attachment information acquired by the attachment information acquisition unit, and the working radius, boom hoisting angle, and jib hoisting angle acquired by the rotation information acquisition unit.

[0032] With this configuration, even with the same working radius, the attachment's resistance to lateral loads changes depending on the boom hoisting angle and jib hoisting angle, making it possible to set an optimal maximum slewing angular velocity.

[0033] In the above configuration, it is desirable that the angular velocity setting unit sets the maximum swing angular velocity in accordance with the combination of the boom hoisting angle and the jib hoisting angle that maximizes the deflection of the attachment due to the lateral load for the same working radius.

[0034] With this configuration, even if the working radius is the same, the maximum rotation angular velocity is set according to the most stringent boom hoisting angle and jib hoisting angle conditions in terms of deflection, so that rotation operations can be performed safely.

[0035] In the above configuration, it is desirable that the rotation information includes information regarding a maximum working radius set in accordance with the load of the suspended load in order to prevent the crane from tipping over, and that the angular velocity setting unit sets the maximum rotation angular velocity based on the attachment information acquired by the attachment information acquisition unit and the maximum working radius acquired by the rotation information acquisition unit.

[0036] According to this configuration, when the upper rotating body is rotating, the maximum rotation angular velocity can be set without the need to detect and reflect the current working radius.

[0037] In the above configuration, it is preferable that the angular velocity setting unit sets the maximum swing angular velocity when the swing operation of the upper swing body starts, and maintains the set maximum swing angular velocity during the swing operation.

[0038] According to this configuration, the maximum rotation angular velocity does not change during the rotation operation, so that it is possible to prevent a decrease in operability for the operator due to frequent sudden changes in the angular velocity of the upper rotating body.

[0039] In the above configuration, it is desirable that the angular velocity setting unit updates the maximum rotation angular velocity at predetermined intervals during the rotation operation of the upper rotating body, and the rotation control unit controls the rotation drive unit so that the rotation angular velocity of the upper rotating body does not exceed the maximum rotation angular velocity updated by the angular velocity setting unit.

[0040] According to this configuration, the maximum turning angular velocity is updated in accordance with changes in turning information during a turning operation, thereby improving workability while ensuring safety.

[0041] In the above configuration, it is desirable that the rotation information acquisition unit acquires information regarding the working radius that changes in accordance with the raising and lowering operation of the attachment during the rotation operation of the upper rotating body, and that the angular velocity setting unit updates the maximum rotation angular velocity based on the information regarding the working radius acquired by the rotation information acquisition unit.

[0042] With this configuration, even if the working radius changes due to the raising and lowering of the attachment during a swing operation, an optimal maximum swing angular velocity can be set. In particular, when the working radius decreases due to the raising of the attachment, the actual swing angular velocity can also be increased by setting a higher maximum swing angular velocity, thereby improving workability while ensuring safety. Furthermore, when the working radius increases due to the lowering of the attachment, safety can be ensured by further restricting the swing angular velocity.

[0043] In the above configuration, it is desirable that the angular velocity setting unit sets the maximum rotation angular velocity when the rotation operation of the upper rotating body starts and further calculates a maximum circumferential speed corresponding to the maximum rotation angular velocity, and sets the maximum rotation angular velocity during the rotation operation of the upper rotating body so that the circumferential speed of the tip of the attachment does not exceed the maximum circumferential speed.

[0044] According to this configuration, the maximum peripheral speed is controlled to be constant during the rotation operation, so that the maximum value of the load speed does not change even if the working radius changes, thereby improving workability.

[0045] In the above configuration, it is desirable that the system further includes an input unit that allows an operator to input an effective maximum rotation angular velocity having the maximum rotation angular velocity set by the angular velocity setting unit as a maximum value, and that the rotation control unit controls the rotation drive unit so that the rotation angular velocity of the upper rotating body does not exceed the effective maximum rotation angular velocity input to the input unit.

[0046] According to this configuration, the worker can further limit the maximum rotation angular velocity according to his / her own ability and preference, thereby enabling the worker to perform the rotation operation more safely.

[0047] In the above configuration, it is preferable that the input unit is configured to enable selection of the effective maximum turning angular velocity in stages.

[0048] According to this configuration, the worker can select the effective maximum rotation angular velocity in stages depending on the strength and type of the suspended load, thereby enabling safer rotation operations.

[0049] In the above configuration, the swing drive unit of the crane includes an engine having an output shaft, a hydraulic pump that is connected to the output shaft and discharges hydraulic oil by power input from the output shaft, the hydraulic pump being a variable displacement type that can receive an input of a tilt command signal and change the maximum discharge amount of hydraulic oil in accordance with the magnitude of the tilt command signal, and a hydraulic pump that has a plurality of hydraulic chambers therein and receives hydraulic oil supplied from the hydraulic pump into one of the plurality of hydraulic chambers and discharges hydraulic oil from the other hydraulic chambers, thereby generating a driving force for swinging the upper swing body. and a flow rate adjustment mechanism including a hydraulic pump and a swing motor of the type, the hydraulic pump including a control valve arranged so as to be interposed between the hydraulic pump and the swing motor, and adjusting the flow rate of hydraulic oil discharged from the hydraulic pump and supplied to the swing motor in response to the swing command signal output from the operating unit, and it is desirable that the swing control unit inputs a tilt command signal corresponding to the maximum swing angular velocity set by the angular velocity setting unit to the hydraulic pump, thereby limiting the discharge amount of hydraulic oil discharged from the hydraulic pump so that the swing angular velocity of the upper swing body does not exceed the maximum swing angular velocity.

[0050] According to this configuration, the rotation control unit adjusts the tilt of the hydraulic pump to limit the amount of hydraulic oil discharged from the hydraulic pump so that the rotation angular velocity of the upper rotating body does not exceed the maximum rotation angular velocity, thereby reliably limiting the rotation angular velocity of the upper rotating body.

[0051] In the above configuration, it is desirable that the hydraulic pump discharges a minimum discharge amount of hydraulic oil that is greater than zero, and that the swing control unit, when the discharge amount of the hydraulic pump corresponding to the maximum swing angular velocity set by the angular velocity setting unit is greater than the minimum discharge amount, inputs a tilt command signal corresponding to the maximum swing angular velocity to the hydraulic pump, thereby limiting the discharge amount of hydraulic oil discharged from the hydraulic pump so that the swing angular velocity of the upper swing body does not exceed the maximum swing angular velocity, while, when the discharge amount of the hydraulic pump corresponding to the maximum swing angular velocity set by the angular velocity setting unit is smaller than the minimum discharge amount, inputs a forced command signal corresponding to the maximum swing angular velocity to the flow rate adjustment mechanism, thereby limiting the flow rate of hydraulic oil supplied to the swing motor from the flow rate adjustment mechanism so that the swing angular velocity of the upper swing body does not exceed the maximum swing angular velocity regardless of the magnitude of the swing command signal.

[0052] According to this configuration, even if the maximum swing angular velocity required by the angular velocity setting unit cannot be achieved by adjusting the tilt of the hydraulic pump due to the performance of the hydraulic pump, the swing control unit can input a forced command signal to the flow rate adjustment mechanism to limit the flow rate of hydraulic oil supplied to the swing motor, thereby reliably limiting the swing angular velocity of the upper swing body.

[0053] In the above configuration, the swing drive unit of the crane preferably includes an engine having an output shaft, a hydraulic pump connected to the output shaft and discharging hydraulic oil by power input from the output shaft, a hydraulic swing motor having a plurality of hydraulic chambers therein and receiving hydraulic oil supplied from the hydraulic pump into one of the plurality of hydraulic chambers and discharging hydraulic oil from the other hydraulic chambers, thereby generating driving force for swinging the upper swing body, and a flow rate adjustment mechanism including a control valve disposed between the hydraulic pump and the swing motor and adjusting the flow rate of hydraulic oil discharged from the hydraulic pump and supplied to the swing motor in accordance with the swing command signal output from the operation unit, and the swing control unit preferably inputs a forced command signal corresponding to the maximum swing angular velocity set by the angular velocity setting unit to the flow rate adjustment mechanism, thereby limiting the flow rate of hydraulic oil supplied to the swing motor from the flow rate adjustment mechanism so that the swing angular velocity of the upper swing body does not exceed the maximum swing angular velocity regardless of the magnitude of the swing command signal.

[0054] According to this configuration, the rotation control unit inputs a forced command signal to the flow rate adjustment mechanism, thereby limiting the amount of hydraulic oil supplied to the rotation motor so that the rotation angular velocity of the upper rotating body does not exceed the maximum rotation angular velocity, thereby reliably limiting the rotation angular velocity of the upper rotating body.

[0055] In the above configuration, the swing drive unit of the crane includes an engine with an output shaft, a hydraulic pump connected to the output shaft and discharging hydraulic oil by power input from the output shaft, a hydraulic swing motor having a plurality of hydraulic chambers therein and receiving hydraulic oil supplied from the hydraulic pump into one of the plurality of hydraulic chambers and discharging hydraulic oil from the other hydraulic chambers, thereby generating a driving force for swinging the upper swing body, and a flow rate adjustment mechanism including a control valve disposed between the hydraulic pump and the swing motor and adjusting the flow rate of hydraulic oil discharged from the hydraulic pump and supplied to the swing motor in response to the swing command signal output from the operation unit, and it is desirable that the swing control unit limits the rotation speed of the engine so that the swing angular velocity of the upper swing body does not exceed the maximum swing angular velocity.

[0056] According to this configuration, the rotation control unit limits the engine speed so that the rotation angular velocity of the upper rotating body does not exceed the maximum rotation angular velocity, thereby ensuring that the rotation angular velocity of the upper rotating body can be restricted.

[0057] According to another aspect of the present invention, there is provided a crane comprising: a lower body; an upper rotating body supported on the lower body so as to be rotatable about a rotation center axis extending in a vertical direction relative to the lower body; an operation unit that receives an operation to rotate the upper rotating body relative to the lower body and outputs a rotation command signal corresponding to the magnitude of the operation; a rotation drive unit that can rotate the upper rotating body relative to the lower body; an attachment that is detachable from the upper rotating body and includes a base end that is supported on the upper rotating body so as to be rotatable in a hoisting direction and a tip end opposite the base end; a load rope that hangs down from the tip end of the attachment and is connected to a suspended load; and the rotation control device described above that controls the rotation drive unit so that the rotation angular velocity of the upper rotating body does not exceed at least a maximum rotation angular velocity set in accordance with attachment information of the attachment.

[0058] According to this configuration, the angular velocity setting unit sets the maximum rotation angular velocity for the rotation operation of the upper rotating body in accordance with the attachment information, making it possible to perform stable rotation operations while efficiently preventing large lateral loads from being applied to the attachment based on the worker's rotation operation, which could cause damage or breakage to the attachment. [Effects of the Invention]

[0059] According to the present invention, a crane rotation control device and a crane equipped with the same are provided that can efficiently prevent a large lateral load from being applied to an attachment due to the rotation movement of the upper rotating body based on the worker's rotation operation, which would cause the attachment to be damaged or broken. [Brief explanation of the drawings]

[0060] [Figure 1] 1 is a side view of a crane equipped with a swing control device according to a first embodiment of the present invention. [Figure 2] FIG. 1 is a hydraulic circuit diagram of a slewing drive unit of a crane according to a first embodiment of the present invention. [Figure 3] 1 is a block diagram of a turning control device according to a first embodiment of the present invention. [Figure 4] 10 is a graph showing a transition of an operation amount received by an operating lever during a swing operation of a crane. [Figure 5] 10 is a graph showing the transition of the rotation angular velocity of the upper rotating body during a rotation operation of the crane. [Figure 6] 10 is a graph showing the change in the amount of load swing of a suspended load during a swing operation of a crane. [Figure 7] 10 is a graph showing the change in the amount of swing of the tip of the attachment during a swing operation of the crane. [Figure 8] 10 is a graph showing the relationship between the rotation angular velocity of the upper rotating body and the maximum value of the swing of the attachment. [Figure 9] 10 is a graph showing the relationship between the rotation angular velocity of the upper rotating body and the stress applied to the attachment. [Figure 10]4 is a graph showing the relationship between the swing angular velocity limit value set in the swing control device according to the first embodiment of the present invention and the attachment length. [Figure 11] 4 is a graph showing the relationship between a swing angular velocity limit value set in the swing control device according to the first embodiment of the present invention and a pump displacement. [Figure 12] 4 is a graph showing the relationship between the operation amount of the operating lever and the swing angular velocity of the upper swing body in the crane equipped with the swing control device according to the first embodiment of the present invention. [Figure 13] 3 is a flowchart of the crane swing control executed by the swing control device according to the first embodiment of the present invention. [Figure 14] 10 is a graph showing the relationship between engine speed and pump displacement in the swing control executed by the swing control device according to the second embodiment of the present invention. [Figure 15] 10 is a graph showing the relationship between the operation amount of the operating lever and the swing angular velocity of the upper swing body in the swing control executed by the swing control device according to the second embodiment of the present invention. [Figure 16] 10 is a graph showing the relationship between the operation amount of the operating lever and the secondary pressure of the electromagnetic proportional valve in the swing control executed by the swing control device according to the third embodiment of the present invention. [Figure 17] 10 is a graph showing the relationship between the secondary pressure of the electromagnetic proportional valve and the swing angular velocity of the upper swing body in the swing control executed by the swing control device according to the third embodiment of the present invention. [Figure 18] 10 is a flowchart of the crane swing control executed by the swing control device according to the third embodiment of the present invention. [Figure 19] 10 is a flowchart of the swing control of the crane executed by the swing control device according to the modified example of the third embodiment of the present invention. [Figure 20] FIG. 10 is a schematic diagram of a boom and a jib of a crane equipped with a swing control device according to a fourth embodiment of the present invention. [Figure 21] 10 is a graph showing the relationship between the working radius and the load factor in the turning control executed by the turning control device according to the fourth embodiment of the present invention. [Figure 22]10 is a graph showing the transition of the detected value of the suspended load during the rotation control performed by the rotation control device according to the fifth embodiment of the present invention. [Figure 23] 10 is a graph showing fluctuations in the rotation angular velocity of the upper rotating body. [Figure 24] 10 is a graph showing the transition of the swing angular velocity of the upper swing body in the swing control executed by the swing control device according to the fifth embodiment of the present invention. [Figure 25] FIG. 10 is a side view of a crane equipped with a swing control device according to a modified embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0061] First Embodiment Hereinafter, each embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a side view of a crane 10 according to a first embodiment of the present invention. Note that, although directions such as "up," "down," "front," and "rear" are shown in each drawing hereinafter, these directions are shown for the convenience of explaining the structure and assembly method of the crane 10 according to each embodiment, and do not limit the direction of movement or usage of the crane according to the present invention.

[0062] The crane 10 comprises an upper rotating body 12 corresponding to the crane body, a lower running body 14 (lower body) that supports the upper rotating body 12 so that it can rotate, an attachment 10S (also called a hoisting body) that includes a boom 16 and a jib 18, and a mast 20 that is a member for raising and lowering the boom. The upper rotating body 12 is supported by the lower running body 14 so that it can rotate about a rotation center axis CL that extends in the vertical direction relative to the lower running body 14. A counterweight 13 is mounted on the rear of the upper rotating body 12 to adjust the balance of the crane 10. A cab 15 is provided at the front end of the upper rotating body 12. The cab 15 corresponds to the driver's seat of the crane 10.

[0063] The attachment 10S includes a base end portion supported on the upper rotating body 12 so as to be rotatable in the hoisting direction, and a tip end portion opposite the base end portion, and is detachable from the upper rotating body 12. As described above, in this embodiment, the attachment 10S includes the boom 16 and the jib 18.

[0064] The boom 16 shown in FIG. 1 is a so-called lattice type and is composed of a lower boom 16A, one or more (three in the illustrated example) intermediate booms 16B, 16C, and 16D, and an upper boom 16E. Specifically, the lower boom 16A is connected to the front of the upper rotating structure 12 so as to be rotatable in the hoisting direction. The intermediate booms 16B, 16C, and 16D are detachably attached to the tip of the lower boom 16A in that order. The upper boom 16E is detachably attached to the tip of the intermediate boom 16D, and the jib 18, as well as a rear strut 21 and a front strut 22 for rotating the jib 18, are rotatably connected to the tip of this upper boom 16E. The boom 16 is rotatably supported by the upper rotating structure 12 around a rotation axis extending in the left-right direction, with a boom foot pin 16S provided at the lower end as a fulcrum.

[0065] The boom 16 has an intermediate boom sheave 46 and idler sheaves 32S, 34S, and 36S. The intermediate boom sheave 46 is disposed on the rear surface of the tip end of the intermediate boom 16D. The idler sheave 32S, idler sheave 34S, and idler sheave 36S are rotatably supported on the rear surface of the base end of the boom 16.

[0066] However, the present invention is not limited to a specific boom structure. For example, the boom may have no intermediate members, or may have a different number of intermediate members than those described above. Furthermore, the boom may be constructed of a single member.

[0067] The specific structure of the jib 18 is also not limited. The base end of the jib 18 is rotatably connected (pivoted) to the tip end of the upper boom 16E of the boom 16, and the rotation axis of the jib 18 is a horizontal axis parallel to the rotation axis (boom foot pin 16S) of the boom 16 relative to the upper rotating body 12.

[0068] The mast 20 has a base end and a pivoting end, and the base end is pivotally connected to the upper rotating body 12. The pivoting axis of the mast 20 is parallel to the pivoting axis of the boom 16 and is located immediately rearward of the pivoting axis of the boom 16. In other words, the mast 20 is pivotable in the same direction as the boom 16 is raised and lowered. Meanwhile, the pivoting end of the mast 20 is connected to the tip of the boom 16 via a pair of boom guy lines 24 on the left and right. This connection coordinates the rotation of the mast 20 and the rotation of the boom 16.

[0069] Furthermore, the crane 10 is equipped with a pair of left and right backstops 23, a rear strut 21, a front strut 22, a pair of left and right strut backstops 25 and guy lines 26, and a pair of left and right jib guy lines 28.

[0070] A pair of left and right backstops 23 are provided on both the left and right sides of the lower boom 16A of the boom 16. These backstops 23 come into contact with the center of the upper rotating body 12 in the fore-and-aft direction when the boom 16 reaches the upright position shown in Figure 1. This contact prevents the boom 16 from being blown backward by strong winds, etc.

[0071] The rear strut 21 is pivotally supported at the tip of the boom 16. The rear strut 21 is held in a position where it extends from the tip of the upper boom 16E toward the boom-raising side (left side in FIG. 1 ) from the tip of the upper boom 16E. To maintain this position, a pair of left and right strut backstops 25 and a pair of left and right guy lines 26 are interposed between the rear strut 21 and the boom 16. The strut backstops 25 are interposed between the intermediate boom 16D and the middle section of the rear strut 21, supporting the rear strut 21 from below. The guy lines 26 are tensioned to connect the tip of the rear strut 21 to the lower boom 16A of the boom 16, and their tension regulates the position of the rear strut 21. The rear strut 21 also has a sheave block 47 and rear strut idler sheaves 52 and 62. The sheave block 47 is located at the pivoting end of the rear strut 21 and includes multiple sheaves arranged in the width direction. The rear strut idler sheaves 52, 62 are arranged in a portion of the rear strut 21 that is closer to the base end than the longitudinal center portion, and each includes a plurality of sheaves arranged in the width direction.

[0072] The front strut 22 is disposed rearward of the jib 18 and is pivotally supported on the tip of the boom 16 (upper boom 16E) so as to rotate in conjunction with the jib 18. Specifically, a pair of left and right jib guy lines 28 are tensioned to connect the tip of the front strut 22 to the tip of the jib 18. Therefore, when the front strut 22 rotates, the jib 18 is also rotated integrally with the front strut 22. As shown in FIG. 1 , the rear strut 21 is disposed rearward of the front strut 22 and forms a substantially isosceles triangle shape with the front strut 22. The front strut 22 has a sheave block 48 and front strut idler sheaves 53, 63. The sheave block 48 is disposed at the rotating end of the front strut 22 and includes a plurality of sheaves arranged in the width direction. The front strut idler sheaves 53, 63 are arranged in a portion of the front strut 22 that is closer to the base end than the longitudinal center portion, and each includes a plurality of sheaves arranged in the width direction.

[0073] The crane 10 also includes various winches. Specifically, the crane 10 includes a boom hoist winch 30 for raising and lowering the boom 16, a jib hoist winch 32 for rotating the jib 18 in the hoisting direction, and a main winch 34 and an auxiliary winch 36 for hoisting and lowering a load. The crane 10 also includes a boom hoist rope 38, a jib hoist rope 44, a main hoist rope 50 (load rope), and an auxiliary hoist rope 60. In the crane 10 according to this embodiment, the jib hoist winch 32, the main winch 34, and the auxiliary winch 36 are installed near the base end of the boom 16. The boom hoist winch 30 is also installed on the upper rotating body 12. The locations of these winches 30, 32, 34, and 36 are not limited to those described above.

[0074] The boom hoist winch 30 winds in and pays out the boom hoist rope 38. The boom hoist rope 38 is laid out so that this winding and paying out causes the mast 20 to rotate. Specifically, sheave blocks 40, 42, each with a plurality of sheaves arranged in the width direction, are provided at the rotating end of the mast 20 and the rear end of the upper rotating body 12, and the boom hoist rope 38 pulled out from the boom hoist winch 30 is stretched between the sheave blocks 40, 42. Therefore, when the boom hoist winch 30 winds in and pays out the boom hoist rope 38, the distance between the two sheave blocks 40, 42 changes, which causes the mast 20 and, in turn, the boom 16, which is linked to it, to rotate in the hoisting direction.

[0075] The jib hoist winch 32 winds in and pays out the jib hoist rope 44, which is wound between the rear strut 21 and the front strut 22. The jib hoist rope 44 is arranged so that the winding and paying out of the rope rotates the front strut 22. Specifically, the jib hoist rope 44 pulled out from the jib hoist winch 32 is hooked around the idler sheave 32S and the intermediate boom sheave 46, and is further looped between the sheave blocks 47 and 48 multiple times. Therefore, by winding and paying out the jib hoist rope 44, the jib hoist winch 32 changes the distance between the sheave blocks 47 and 48, thereby rotating the front strut 22 relative to the rear strut 21. As a result, the jib hoist winch 32 raises and lowers the jib 18, which is linked to the front strut 22.

[0076] The main hoisting winch 34 hoists and lowers a load using a main hoisting rope 50. For this main hoisting, as described above, a rear strut idler sheave 52, a front strut idler sheave 53, and a main hoisting guide sheave 54 are rotatably mounted near the base end of the rear strut 21, near the base end of the front strut 22, and at the tip of the jib 18, respectively. Furthermore, a main hoisting sheave block is provided adjacent to the main hoisting guide sheave 54, with multiple main hoisting point sheaves 56 arranged in the width direction. The main hoisting rope 50 pulled out from the main hoisting winch 34 is looped around the idler sheave 34S, the rear strut idler sheave 52, the front strut idler sheave 53, and the main hoisting guide sheave 54, in that order, and is stretched between the main hoisting point sheave 56 of the sheave block and a sheave 58 of a sheave block mounted on a main load hook 57. Therefore, when the main hoisting winch 34 winds or unwinds the main hoisting rope 50, the distance between the two sheaves 56, 58 changes, causing the main hook 57 connected to the main hoisting rope 50 hanging down from the tip of the jib 18 to be wound up or down. In this manner, in this embodiment, the main hoisting rope 50 (hanging load rope) hangs down from the tip of the attachment 10S and is connected to the hanged load via the main hook 57.

[0077] Similarly, the auxiliary winch 36 hoists and lowers a load using an auxiliary hoisting rope 60. For this auxiliary hoisting, a rear strut idler sheave 62, a front strut idler sheave 63, and an auxiliary hoisting guide sheave 64 are rotatably mounted coaxially with the rear strut idler sheave 52, the front strut idler sheave 53, and the main hoisting guide sheave 54, respectively, and an auxiliary hoisting point sheave (not shown) is rotatably mounted adjacent to the auxiliary hoisting guide sheave 64. The auxiliary hoisting rope 60 pulled out from the auxiliary hoisting winch 36 is hung around the rear strut idler sheave 62, the front strut idler sheave 63, and the auxiliary hoisting guide sheave 64 in that order, and is suspended from the auxiliary hoisting point sheave. Therefore, when the auxiliary hoisting winch 36 winds or unwinds the auxiliary hoisting rope 60, an auxiliary hook (not shown) for the load connected to the end of the auxiliary hoisting rope 60 is hoisted or lowered.

[0078] FIG. 2 is a hydraulic circuit diagram of the swing drive unit 7S of the crane 10 according to this embodiment. FIG. 3 is a block diagram of the swing control device 8S according to this embodiment. The crane 10 has the swing drive unit 7S and the swing control device 8S. The swing drive unit 7S is capable of swinging the upper swing structure 12 relative to the lower running structure 14 (swing operation). Furthermore, when the swing operation of the upper swing structure 12 of the crane 10 is performed, the swing control device 8S swings the upper swing structure 12 while limiting the swing angular velocity of the upper swing structure 12 so as to prevent damage to the attachment 10S (boom 16, jib 18).

[0079] 2, the swing drive unit 7S has an engine 70, a hydraulic pump 71 including a tilt adjustment unit 71S (FIG. 3), a swing motor 72, a control valve 73, a relief valve 74, an engine speed detection unit 75, a swing angular velocity detection unit 76, a first electromagnetic proportional valve 77, and a second electromagnetic proportional valve 78. The crane 10 also has a control unit 80, an operation unit 81, and an input unit 82. Furthermore, with reference to FIG. 3, the crane 10 also has a hoisting angle detection unit 66 and a load detection unit 67.

[0080] Engine 70 has an output shaft. In this embodiment, engine 70 can be switched between a high idle mode and a low idle mode in response to an operation (input) by an operator. The rotation speed of the output shaft in high idle mode is set higher than the rotation speed of the output shaft in low idle mode, and the high idle mode is selected by the operator when working with a relatively large load.

[0081] The hydraulic pump 71 is connected to the output shaft of the engine 70 and receives power input from the output shaft. The hydraulic pump 71 sucks in and discharges hydraulic oil from a tank to be supplied to the swing motor 72. The hydraulic pump 71 according to this embodiment is a variable displacement hydraulic pump, and the capacity (displacement volume) of the hydraulic pump 71 changes when a tilt command signal is input to a tilt adjustment unit 71S (regulator) included in the hydraulic pump 71. This changes the pump discharge flow rate, which is the flow rate of hydraulic oil discharged from the hydraulic pump 71. In other words, the hydraulic pump 71 is capable of receiving an input of a tilt command signal and changing the maximum discharge rate of hydraulic oil according to the magnitude of the tilt command signal. The tilt command signal is output from a swing control unit 802 (FIG. 3) of the control unit 80, which will be described later.

[0082] The swing motor 72 is a hydraulic swing motor that drives the upper swing body 12 to swing. The swing motor 72 has multiple hydraulic chambers inside, and generates a driving force to swing the upper swing body 12 by receiving hydraulic oil supplied from the hydraulic pump 71 into one of the multiple hydraulic chambers and discharging hydraulic oil from the other hydraulic chambers. Specifically, the swing motor 72 is disposed between the upper swing body 12 and the lower traveling body 14 in FIG. 1 . The swing motor 72 has a motor shaft including a pinion and is fixed to the upper swing body 12. Meanwhile, the lower traveling body 14 has a circumferentially formed swing gear (not shown). The pinion of the swing motor 72 engages with the swing gear, causing the upper swing body 12 to swing in response to the rotation of the swing motor 72. For this reason, the swing motor 72 is disposed near the circumference of the swing gear. The swing motor 72 has a first motor port 72A and a second motor port 72B. The swing motor 72 receives hydraulic oil through the first motor port 72A to rotate the upper swing body 12 in a first direction (e.g., leftward) and discharges hydraulic oil through the second motor port 72B. On the other hand, the swing motor 72 receives hydraulic oil through the second motor port 72B to rotate the upper swing body 12 in a second direction (e.g., rightward) opposite to the first direction and discharges hydraulic oil through the first motor port 72A.

[0083] The control valve 73 is disposed in the hydraulic oil passage so as to be interposed between the hydraulic pump 71 and the swing motor 72. The control valve 73 operates to switch the direction of hydraulic oil supply from the hydraulic pump 71 to the swing motor 72 and to adjust the flow rate of the hydraulic oil. The control valve 73 is connected to the first motor port 72A and the second motor port 20B of the swing motor 72, respectively.

[0084] Control valve 73 operates to switch between a left turning position 73A (first turning position), a neutral position 73B (neutral turning position), and a right turning position 73C (second turning position) in response to a pilot pressure input to control valve 73. Control valve 73 has a pair of pilot ports, namely, a left turning pilot port 73P and a right turning pilot port 73Q. Control valve 73 is maintained in the neutral position 73B when no pilot pressure is input to either left turning pilot port 73P or right turning pilot port 73Q. Control valve 73 is switched to left turning position 73A when pilot pressure is input to left turning pilot port 73P, and is switched to right turning position 73C when pilot pressure is input to right turning pilot port 73Q. Control valve 73 opens with an opening area corresponding to the pilot pressure, changing the flow rate of hydraulic oil.

[0085] In the left turning position 73A, the control valve 73 supplies hydraulic oil discharged from the hydraulic pump 71 to the motor first port 72A and forms an oil passage that guides hydraulic oil discharged from the motor second port 72B to the tank. In the right turning position 73C, the control valve 73 supplies hydraulic oil discharged from the hydraulic pump 71 to the motor second port 72B and forms an oil passage that guides hydraulic oil discharged from the motor first port 72A to the tank. In addition, in the neutral position 73B, the control valve 73 allows hydraulic oil to circulate between the motor first port 72A and the motor second port 72B.

[0086] The relief valve 74 operates so that the pressure in the oil passage (bleed-off line) between the control valve 73 and the tank does not exceed a predetermined pressure.

[0087] The engine rotation speed detection unit 75 detects the rotation speed (or rotation number) of the output shaft of the engine 70. The swing angular velocity detection unit 76 detects the rotation speed (or rotation number) of the swing motor 72. The swing angular velocity detection unit 76 also detects the rotation direction (first direction, second direction) of the swing motor 72.

[0088] The operating unit 81 is disposed in the cab 15 (FIG. 1) and is operated by an operator to raise and lower the attachment 10S and to rotate the upper rotating body 12. The following describes the operating unit 81 related to the rotation of the upper rotating body 12. The operating unit 81 receives an operation to rotate the upper rotating body 12 relative to the undercarriage 14, outputs a rotation command signal corresponding to the magnitude of the operation, and inputs the signal to the control unit 80. The operating unit 81 has an operating lever 81A and a remote control unit 81B. The operating lever 81A can be selectively operated to a first operating range for rotating the upper rotating body 12 in the first direction, a second operating range for rotating the upper rotating body 12 in the second direction, and a neutral operating range between the first and second operating ranges. The amount of operation of the operating lever 81A in the first operating range and the second operating range are variable.

[0089] When the operator operates the operation lever 81A to the first operation range (first turning operation), the remote control unit 81B inputs a signal corresponding to the amount of operation received by the operation lever 81A to the control unit 80. When the operator operates the operation lever 81A to the second operation range (second turning operation), the remote control unit 81B inputs a signal corresponding to the amount of operation received by the operation lever 81A to the control unit 80. As a result, command signals are input from the control unit 80 to the first solenoid proportional valve 77 and the second solenoid proportional valve 78.

[0090] The first solenoid proportional valve 77 and the second solenoid proportional valve 78 adjust the pilot pressure input to the control valve 73 in response to a command signal provided from the swing control unit 802 of the control unit 80. Specifically, the first solenoid proportional valve 77 and the second solenoid proportional valve 78 are interposed between a pilot hydraulic source and the left swing pilot port 73P and the right swing pilot port 73Q of the control valve 73, and are connected to the left swing pilot port 73P and the right swing pilot port 73Q via pilot lines, respectively. When a command signal is provided from the swing control unit 802 (FIG. 3), the first solenoid proportional valve 77 opens to reduce the pilot pressure supplied to the left swing pilot port 73P. Furthermore, when a command signal is provided from the swing control unit 802, the second solenoid proportional valve 78 opens to reduce the pilot pressure supplied to the right swing pilot port 73Q. At this time, the stroke amount of the spool of the control valve 73 changes in response to changes in the pilot pressure input to the left swing pilot port 73P and the right swing pilot port 73Q.

[0091] The input unit 82 accepts input of various information by an operator. The information input from the input unit 82 is stored (memorized) in a memory unit 803 of the control unit 80, which will be described later. In addition, the operator can input (switch) the execution of the swing control performed by the swing control device 8S according to this embodiment on / off using an operation switch (not shown) included in the input unit 82.

[0092] The hoisting angle detection unit 66 detects the hoisting angle of the attachment 10S, i.e., the angle relative to the ground. In this embodiment, the hoisting angle detection unit 66 is capable of detecting the hoisting angle (ground angle) of the boom 16 and the hoisting angle of the jib 18.

[0093] The load detection unit 67 detects the load (suspended load load) of the suspended load connected to the main hoisting rope 50 (auxiliary hoisting rope 60). The load detection unit 67 is composed of a tension sensor attached to the main hoisting winch 34 (auxiliary hoisting winch 36), etc.

[0094] The control unit 80 comprehensively controls the operation of the crane 10, and is electrically connected to send and receive control signals to the operation unit 81, input unit 82, swing angular velocity detection unit 76, engine rotation speed detection unit 75, hoisting angle detection unit 66, load detection unit 67, tilt adjustment unit 71S, first electromagnetic proportional valve 77, second electromagnetic proportional valve 78, etc. The control unit 80 is also electrically connected to other units provided in the crane 10.

[0095] The control unit 80 is composed of a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores a control program, a RAM (Random Access Memory) that is used as the CPU's working area, etc., and when the CPU executes the control program, it operates to functionally include an attachment information acquisition unit 800A, a turning operation information acquisition unit 800B (turning information acquisition unit), an angular velocity setting unit 801, a turning control unit 802, and a memory unit 803.

[0096] The attachment information acquisition unit 800A acquires attachment information. The attachment information is information for setting a maximum swing angular velocity, which is the maximum value of the swing angular velocity, based on the lateral load acting on the attachment 10S. As an example, the attachment information is information specific to the attachment 10S related to at least one of the strength of the attachment 10S against the lateral load and the magnitude of the lateral load. In other words, the attachment information is information that the attachment 10S has even when the attachment 10S is detached from the upper structure 12. The lateral load is a load acting on the attachment 10S in the direction of rotation of the upper structure 12 as the upper structure 12 rotates. As an example, the attachment information includes the length of the attachment 10S from the base end to the tip end, and is input by the operator via the input unit 82.

[0097] The swing operation information acquisition unit 800B acquires swing operation information (swing information). The swing operation information is information related to the conditions for the swing operation of the upper swing body 12 for setting the maximum swing angular velocity. In other words, the swing operation information is information related to the conditions for the swing operation of the upper swing body 12 when the attachment 10S is attached to the upper swing body 12, and is information related to the magnitude of the lateral load. As an example, the swing operation information includes the suspended load and the working radius of the attachment 10S. The working radius is the distance from the base end to the tip end of the attachment 10S (jib 18) in a plan view.

[0098] The angular velocity setting unit 801 sets a maximum swing angular velocity, which is the maximum value of the swing angular velocity of the upper swing body 12 allowed in the swing operation of the upper swing body 12, based on at least the attachment information acquired by the attachment information acquisition unit 800A. Furthermore, the angular velocity setting unit 801 may set the maximum swing angular velocity based on the attachment information acquired by the attachment information acquisition unit 800A and the swing operation information acquired by the swing operation information acquisition unit 800B.

[0099] The swing control unit 802 receives the swing command signal output from the operation unit 81 and controls the swing drive unit 7S so that the upper swing body 12 swings relative to the lower travel unit 14 in response to the swing command signal. The swing control unit 802 also controls the swing drive unit 7S so that the swing angular velocity of the upper swing body 12 does not exceed the maximum swing angular velocity set by the angular velocity setting unit 801. In this embodiment, the swing control unit 802 inputs a tilt command signal corresponding to the maximum swing angular velocity set by the angular velocity setting unit 801 to the hydraulic pump 71, thereby limiting the discharge amount of hydraulic oil discharged from the hydraulic pump 71 so that the swing angular velocity of the upper swing body 12 does not exceed the set maximum swing angular velocity.

[0100] The storage unit 803 stores and outputs information such as various parameters and thresholds referenced by the swing control device 8S during the operation of the crane 10. The storage unit 803 also stores a limit value map (described later) referenced by the angular velocity setting unit 801.

[0101] The control valve 73, the first electromagnetic proportional valve 77, and the second electromagnetic proportional valve 78 constitute a flow rate adjustment mechanism 7T according to this embodiment. The flow rate adjustment mechanism 7T adjusts the flow rate of hydraulic oil discharged from the hydraulic pump 71 and supplied to the swing motor 72 in response to a swing command signal output from the operation unit 81. The engine 70, the hydraulic pump 71, the swing motor 72, and the flow rate adjustment mechanism 7T constitute the swing drive unit 7S. Furthermore, the control unit 80, the engine rotation speed detection unit 75, the swing angular velocity detection unit 76, the hoisting angle detection unit 66, and the load detection unit 67 constitute a swing control device 8S according to this embodiment. The swing control device 8S is used in the crane 10.

[0102] 2 shows the hydraulic circuit related to the swinging operation of the upper rotating body 12 of the crane 10, but the crane 10 also has hydraulic circuits (not shown) related to the traveling operation of the lower running body 14, the raising and lowering operation of the boom 16 and jib 18, and the winding up and lowering operation of the main hoisting rope 50 and the auxiliary hoisting rope 60. When the boom 16 and jib 18 are hoisted, the boom hoist winch 30 and the jib hoist winch 32 described above are each rotationally driven in response to operations input to the operation unit 81. When the main hoisting rope 50 and the auxiliary hoisting rope 60 are hoisted, the main hoisting winch 34 and the auxiliary hoisting winch 36 described above are each rotationally driven in response to operations input to the operation unit 81.

[0103] <About attachment swing during turning> Fig. 4 is a graph showing the change in the amount of operation received by the operating lever 81A during a swing operation of the crane 10. Fig. 5 is a graph showing the change in the swing angular velocity of the upper swing structure 12 during a swing operation of the crane 10. Fig. 6 is a graph showing the change in the amount of load sway of the suspended load during a swing operation of the crane 10. Fig. 7 is a graph showing the change in the amount of swing of the tip of the attachment during a swing operation of the crane 10.

[0104] When the upper rotating body 12 rotates with a load connected to the main hoisting rope 50 (main hook 57) of the crane 10, if an operator operates the control lever 81A as shown in Fig. 4, the rotation drive unit 7S rotates the upper rotating body 12 in accordance with the amount of operation, and the rotation angular velocity of the upper rotating body 12 changes as shown in Fig. 5. The greater the amount by which the operator operates the control lever 81A, the greater the rotation angular velocity of the upper rotating body 12 (Fig. 5).

[0105] During such a rotation of the upper rotating body 12, large load swings may occur depending on the manner of operation by the worker. For example, when the upper rotating body 12 begins to rotate at the start of the rotation operation, the load has inertia and begins to rotate lagging behind the upper rotating body 12. Thereafter, the pendulum motion of the load causes the load to move in such a way as to overtake the upper rotating body 12. As a result, as shown in Figure 6, a movement (load swing) occurs in which the load repeatedly moves ahead, behind, and ahead of the upper rotating body 12. In this case, if the worker decelerates the upper rotating body 12 at the timing when the load is ahead of the upper rotating body 12, the inertial force of the load will cause the load to try to move even further ahead of the upper rotating body 12, resulting in large load swings (the peak at the right end of Figure 6). In other words, if the phase of the load sway during acceleration of the rotation operation (the direction of movement of the suspended load relative to the upper rotating body 12) is the same as the phase of the load sway during deceleration, the amplitudes of the load sway will overlap, resulting in a larger amplitude.

[0106] When this type of load swing amplification occurs, a lateral load acts on the attachment 10S, causing a similar swing at the tip of the attachment 10S (Figure 7), and stress is also generated due to this swing. Furthermore, the heavier the load of the suspended load (heavier the load), the greater the lateral load acting on the attachment 10S, and the greater the swing of the attachment 10S. Similarly, the stress acting on the attachment 10S is greater with a heavy load. Furthermore, even if the upper rotating body 12 rotates at the same swing angular velocity, if the attachment 10S is long, the peripheral speed at its tip will be greater, making the above phenomenon more pronounced. The occurrence of such swing, lateral load, stress, etc. may cause damage or breakage to parts of the attachment 10S.

[0107] <About the limit value map> Fig. 8 is a graph showing the relationship between the swing angular velocity of the upper swing structure 12 and the maximum swing value of the attachment 10S. Fig. 9 is a graph showing the relationship between the swing angular velocity of the upper swing structure 12 and the stress applied to the attachment 10S. Fig. 10 is a graph showing the relationship between the swing angular velocity limit value set in the swing control device 8S according to this embodiment and the attachment length (limit value map).

[0108] In the above-described swing operation, as shown in FIGS. 8 and 9, the swing of the attachment 10S and the stress applied to the attachment 10S tend to increase as the swing angular velocity of the upper swing body 12 increases. Therefore, in this embodiment, a swing tolerance for the attachment 10S is preset to allow safe operation of the crane 10. As shown in FIG. 8, the swing angular velocity required to satisfy this tolerance is set to S1_A or less, taking into account the case of a heavy load. Similarly, a stress tolerance for preventing damage to the attachment 10S is preset, and the swing angular velocity required to satisfy this tolerance is set to S1_B or less, taking into account the case of a heavy load. The smaller of S1_A and S1_B is set as the swing angular velocity limit value S1 and stored in the memory unit 803. It is desirable that this swing angular velocity limit value S1 be set in accordance with the attachment information (specifications, length) of the attachment 10S, and in this embodiment, a limit value map of the swing angular velocity limit value S1 relative to the length of the attachment 10S is stored in the storage unit 803, as shown in Fig. 10. Note that the limit value map is created by evaluating the amount of load sway, the amount of attachment 10S sway, stress, etc., through prior offline analysis and experiments.

[0109] <Regarding the Rotational Movement of the Upper Rotating Body 12> Fig. 11 is a graph showing the relationship between the swing angular velocity limit value set in the swing control device 8S according to this embodiment and the tilt of the hydraulic pump 71. Fig. 12 is a graph showing the relationship between the operation amount of the control lever 81A and the swing angular velocity of the upper swing structure 12 in a crane 10 equipped with the swing control device 8S according to this embodiment. Fig. 13 is a flowchart of the swing control of the crane 10 executed by the swing control device 8S according to this embodiment. The swing control of the upper swing structure 12 using the above-mentioned limit value map will be described in detail below.

[0110] 13, when the operator operates the control lever 81A related to the swing operation and a signal corresponding to the operation is input from the remote control unit 81B to the control unit 80, the angular velocity setting unit 801 determines whether the execution switch for maximum swing angular velocity control is turned on (step S10). If the execution switch is turned on (YES in step S10), the angular velocity setting unit 801 acquires attachment information from the storage unit 803 (step S20). In this embodiment, as described above, length information of the attachment 10S is acquired. The length of the attachment 10S is the sum of the length of the boom 16 and the length of the jib 18.

[0111] Next, the angular velocity setting unit 801 sets the rotation angular velocity limit value S1 (maximum rotation angular velocity) based on the length of the attachment 10S obtained above, by referring to the limit value map (Figure 10) stored in the memory unit 803 (step S30).

[0112] Next, the swing control unit 802 executes swing control of the upper swing body 12 while limiting the swing angular velocity of the upper swing body 12 based on the swing angular velocity limit value S1 set above (step S40). Specifically, the swing control unit 802 controls the tilt of the hydraulic pump 71 to limit the maximum flow rate of hydraulic oil supplied from the hydraulic pump 71 to the swing motor 72 through the control valve 73, thereby limiting the maximum swing angular velocity (swing angular velocity limit value S1) of the upper swing body 12. Details thereof will be described below.

[0113] If the operator operates the operating lever 81A to the maximum extent and all of the flow rate of hydraulic oil discharged from the hydraulic pump 71 is supplied to the swing motor 72 via the control valve 73, the relationship between the tilt qp of the hydraulic pump 71 and the swing angular velocity S of the upper swing body 12 is expressed by the following equation 1. qp×ω_eng×Npump=qm×S×Ngear (Formula 1) Note that ω_eng is the engine speed, Npump is the reduction ratio of the hydraulic pump 71, qm is the motor capacity of the swing motor 72, and Ngear is the swing reduction ratio from the swing motor 72 to the upper swing structure 12. Therefore, in order to limit the swing angular velocity S of the upper swing structure 12 to the swing angular velocity limit value S1, the tilt q1 (FIG. 11) of the hydraulic pump 71 should be set so as to satisfy the following equation 2. q1=qm×S1×Ngear / (ω_eng_Hi×Npump) (Formula 2) It should be noted that ω_eng_Hi is the engine speed (when the engine is in high idle mode).

[0114] 12, when the engine 70 is in engine HIGH idle mode, even if the operator sets the operation amount of the operating lever 81A to the maximum (full lever), the swing angular velocity of the upper rotating body 12 will not exceed the swing angular velocity limit value S1, so the amount of swing of the attachment 10S during a swing operation and the stress acting on the attachment 10S can be kept below allowable values, enabling safe swing operation. Note that the swing control unit 802 can refer to the detection value of the swing angular velocity detection unit 76 to confirm that the swing angular velocity of the upper rotating body 12 is maintained at or below the swing angular velocity limit value S1.

[0115] In addition, in step S10, if the execution switch for the maximum turning angular velocity control is not turned on (NO in step S10), the above-mentioned maximum turning angular velocity control is not executed, and normal turning control (control that does not limit the maximum turning angular velocity) is executed.

[0116] In the present embodiment, as shown in Fig. 10, the swing angular velocity limit value S1 is set using the length of the attachment 10S as attachment information, but even when the length of the attachment 10S (boom length + jib length) is the same, if there are multiple combinations, such as when the boom 16 is relatively long and the jib 18 is relatively short, or when the boom 16 is relatively short and the jib 18 is relatively long, a map of swing angular velocity limit values ​​may be prepared for each combination, and an appropriate swing angular velocity limit value S1 may be set. In this case, too, a limit value map such as the one described above is prepared corresponding to the combination with the most severe conditions for deformation of the attachment 10S and stress acting on the attachment 10S, and the swing angular velocity of the upper swing body 12 is controlled, thereby enabling safer swing operations.

[0117] 8, 9, and 10, the present embodiment has been described in terms of a mode in which the swing angular velocity limit value S1 is set based on a preset heavy load condition for the load of the suspended load, but the suspended load load corresponding to the heavy load condition may be an arbitrary load value input by an operator via the input unit 82 at the work site of the crane 10, or may be an upper limit value (rated load) of the suspended load that is preset in the crane 10. In the former case, the graph (or table) of FIG. 10 is stored in the memory unit 803 in accordance with the magnitude of the suspended load (load factor), and the swing angular velocity limit value S1 corresponding to the suspended load may be set.

[0118] Furthermore, the angular velocity setting unit 801 may set the swing angular velocity limit value S1 of the upper swing body 12 based on swing operation information in addition to the attachment information (length of the attachment 10S) acquired by the attachment information acquisition unit 800A. In this case, when the swing operation information acquisition unit 800B (FIG. 3) acquires the suspended load from the load detection unit 67 as the swing operation information, the angular velocity setting unit 801 selects a graph corresponding to the suspended load from the multiple graphs of "heavy load" and "light load" in FIG. 10, and then sets the swing angular velocity limit value S1 corresponding to the length of the attachment 10S. Note that the multiple graphs shown in FIG. 10 may be composed of three or more graphs corresponding to the magnitude of the suspended load. Furthermore, a predetermined formula using the suspended load load and the length of the attachment 10S as variables may be stored in the storage unit 803 in advance, and the angular velocity setting unit 801 may set the swing angular velocity limit value S1 based on this formula.

[0119] As described above, in this embodiment, the attachment information acquisition unit 800A acquires attachment information. The attachment information is information specific to the attachment 10S for setting a maximum swing angular velocity based on a lateral load, which is a load acting on the attachment 10S in the swing direction of the upper swing body 12 as the upper swing body 12 swings. The angular velocity setting unit 801 sets a maximum swing angular velocity (swing angular velocity limit value S1), which is the maximum value of the swing angular velocity of the upper swing body 12 allowed during the swing operation of the upper swing body 12, based at least on the attachment information acquired by the attachment information acquisition unit 800A. The swing control unit 802 receives the swing command signal output from the operation unit 81 and controls the swing drive unit 7S so that the upper swing body 12 swings relative to the lower traveling body 14 in response to the swing command signal. At this time, the swing control unit 802 controls the swing drive unit 7S so that the swing angular velocity of the upper swing body 12 does not exceed the maximum swing angular velocity set by the angular velocity setting unit 801.

[0120] With this configuration, the angular velocity setting unit 801 sets the maximum rotation angular velocity for the rotation operation of the upper rotating body 12 in accordance with the attachment information, which makes it possible to efficiently prevent a large lateral load from being applied to the attachment 10S based on the worker's rotation operation, causing damage or breakage to the attachment 10S. In particular, the worker does not need to set the rotation angular velocity of the upper rotating body 12 too low by overly considering the rigidity of the attached attachment 10S, and can therefore concentrate on the behavior of the suspended load, etc.

[0121] In particular, the attachment information includes the length of the attachment 10S from the base end to the tip end of the attachment 10S. The angular velocity setting unit 801 sets the maximum turning angular velocity to a first turning angular velocity when the length of the attachment 10S is a first length, and sets the maximum turning angular velocity to a second turning angular velocity smaller than the first turning angular velocity when the length of the attachment 10S is a second length larger than the first length (see the graph in FIG. 10). That is, the angular velocity setting unit 801 sets the maximum turning angular velocity so that the maximum turning angular velocity decreases as the length of the attachment 10S increases.

[0122] According to this configuration, when a relatively long attachment 10S is attached to the upper rotating body 12, the angular velocity setting unit 801 sets the maximum swing angular velocity of the upper rotating body 12 to a relatively small value, thereby preventing a large lateral load from being applied to the attachment 10S and causing damage or breakage to the attachment 10S. In particular, when an attachment 10S with low strength, such as a long attachment, is attached to the upper rotating body 12, even if the operator suddenly inputs a large swing operation using the operation lever 81A, the angular velocity setting unit 801 limits the maximum swing angular velocity, making it possible to keep deformation of the attachment 10S caused by load sway below an allowable value, thereby reducing the risk of damage to the attachment 10S as described above and enabling safe operation.

[0123] In addition, in this embodiment, the angular velocity setting unit 801 sets the maximum turning angular velocity based on the attachment information acquired by the attachment information acquisition unit 800A and the turning operation information acquired by the turning operation information acquisition unit 800B.

[0124] According to this configuration, the angular velocity setting unit 801 sets the maximum rotation angular velocity based on the rotation information during the rotation operation of the crane 10 in addition to the attachment information specific to the attachment, thereby suppressing the occurrence of large lateral loads during the rotation operation and further preventing damage or breakage of the attachment 10S.

[0125] In addition, in this embodiment, the rotation operation information includes information corresponding to the suspended load, which is the load of the suspended load connected to the main hoisting rope 50, and the angular velocity setting unit 801 sets the maximum rotation angular velocity based on the attachment information acquired by the attachment information acquisition unit 800A and the suspended load acquired by the rotation operation information acquisition unit 800B.

[0126] According to this configuration, the angular velocity setting unit 801 sets the maximum rotation angular velocity based on the suspension load, which can have a significant impact on the lateral load acting on the attachment 10S, in addition to the attachment information, thereby reliably preventing a large lateral load from being applied to the attachment 10S.

[0127] In particular, for the same attachment information (attachment length L1 in FIG. 10), the angular velocity setting unit 801 sets the maximum rotation angular velocity to a third rotation angular velocity when the suspended load is a first load (light load), and sets the maximum rotation angular velocity to a fourth rotation angular velocity that is smaller than the third rotation angular velocity when the suspended load is a second load (heavy load) that is larger than the first load (see the graph in FIG. 10). That is, the angular velocity setting unit 801 sets the maximum rotation angular velocity so that the larger the suspended load is, the smaller the maximum rotation angular velocity becomes.

[0128] According to this configuration, when a relatively large load is connected to the attachment 10S, the angular velocity setting unit 801 sets the maximum rotation angular velocity of the upper rotating body 12 to a relatively small value, thereby reliably preventing a large lateral load from being applied to the attachment 10S, thereby preventing damage or breakage of the attachment 10S.

[0129] As described above, the swing operation information acquired by the swing operation information acquisition unit 800B may include information regarding a preset maximum load, which is the maximum load of a load connected to the main hoisting rope 50. In this case, it is desirable that the angular velocity setting unit 801 sets the maximum swing angular velocity based on the attachment information and the maximum load, acquired by the attachment information acquisition unit 800A. The maximum load may be set by an operator at the work site, or may be a rated load preset for the crane 10. In the former case, the operator simply connects a load equal to or less than the set maximum load to the main hoisting rope 50. In the latter case, the operator simply connects a load equal to or less than the preset rated load to the main hoisting rope 50.

[0130] With this configuration, the information for setting the maximum rotation angular velocity is preset prior to the rotation operation, so that the maximum rotation angular velocity can be easily set without the need to detect and reflect the current load of the suspended load using the load detection unit 67 when the upper rotating body 12 rotates.

[0131] In addition, the angular velocity setting unit 801 may set the maximum rotation angular velocity when the upper rotating body 12 starts rotating, and maintain (do not change) the maximum rotation angular velocity during the rotation of the upper rotating body 12.

[0132] With this configuration, the maximum rotation angular velocity does not change during the rotation operation, preventing a decrease in operability for the operator due to frequent sudden changes in the angular velocity of the upper rotating body 12.

[0133] In addition, in this embodiment, the rotation control unit 802 adjusts the tilt of the hydraulic pump 71 to limit the amount of hydraulic oil discharged from the hydraulic pump 71 so that the rotation angular velocity of the upper rotating body 12 does not exceed the maximum rotation angular velocity, thereby reliably limiting the rotation angular velocity of the upper rotating body 12.

[0134] On the other hand, the angular velocity setting unit 801 may update the maximum rotation angular velocity at predetermined intervals during the rotation operation of the upper rotating body 12, and the rotation control unit 802 may control the rotation drive unit 7S so that the rotation angular velocity of the upper rotating body 12 does not exceed the maximum rotation angular velocity updated by the angular velocity setting unit 801.

[0135] With this configuration, the maximum swing angular velocity is updated in response to changes in the swing information during the swing operation, thereby improving workability while ensuring safety. Note that the predetermined interval may be a predetermined time interval or may be an interval of a predetermined swing angle.

[0136] Second Embodiment Next, a crane 10 having a swing control device 8S according to a second embodiment of the present invention will be described. In this embodiment, differences from the first embodiment will be mainly described, and explanations of common points will be omitted (this also applies to the following embodiments). Fig. 14 is a graph showing the relationship between the engine speed and the tilt of the hydraulic pump 71 in the swing control performed by the swing control device 8S according to this embodiment. Fig. 15 is a graph showing the relationship between the operation amount of the operating lever 81A and the swing angular velocity of the upper swing body 12 in the swing control performed by the swing control device 8S according to this embodiment.

[0137] In the first embodiment described above, as shown in Fig. 11, the tilting of the hydraulic pump 71 is set to q1 based on the maximum swing angular velocity (swing angular velocity limit value S1) set by the angular velocity setting unit 801. In the present embodiment, as shown in Fig. 14, the tilting of the hydraulic pump 71 (pump tilting) is set in accordance with the rotation speed of the engine 70.

[0138] In FIG. 14, q1min and q1max are set by the following equations 3 and 4, respectively. q1min=S1×Ngear×qm / ω_eng_Hi ···(Formula 3) q1max=S1×Ngear×qm / ω_eng_Low (Formula 4) It should be noted that ω_eng_Low is the engine speed (in engine low idle mode) and can be obtained from the value detected by engine speed detector 75.

[0139] The swing control unit 802 adjusts the tilting of the hydraulic pump 71 between q1min and q1max as shown in Fig. 14 according to the rotation speed of the engine 70, so that the swing angular velocity of the upper swing structure 12 can be set as shown in Fig. 15. That is, in the engine HIGH idle mode in which the swing angular velocity of the upper swing structure 12 is likely to be large, the tilting of the hydraulic pump 71 is set to q1min in Fig. 14, so that the swing angular velocity of the upper swing structure 12 can be kept below the swing angular velocity limit value S1. Meanwhile, compared to the control by the swing control device 8S according to the first embodiment (engine LOW-2 in Fig. 15), in this embodiment, the tilting of the hydraulic pump 71 is set to q1max in Fig. 14 in the engine LOW idle mode, so that the discharge rate of the hydraulic oil discharged from the hydraulic pump 71 is prevented from being set excessively small. As a result, as shown by engine LOW-1 in Figure 15, the rotation angular velocity of the upper rotating body 12 is allowed to be larger than in the first embodiment (rotation angular velocity S2, where S1 > S2), and the change in the rotation angular velocity of the upper rotating body 12 relative to the rotation speed of the engine 70 is set to be gradual, thereby improving the operability of the rotation operation by the operator.

[0140] Third Embodiment Next, a crane 10 having a swing control device 8S according to a third embodiment of the present invention will be described. Fig. 16 is a graph showing the relationship between the operation amount of the operating lever 81A and the secondary pressure of the electromagnetic proportional valves (first electromagnetic proportional valve 77, second electromagnetic proportional valve 78) in the swing control performed by the swing control device 8S according to this embodiment. Fig. 17 is a graph showing the relationship between the secondary pressure of the electromagnetic proportional valves and the swing angular velocity of the upper swing body 12 in the swing control performed by the swing control device 8S according to this embodiment. Fig. 18 is a flowchart of the swing control of the crane 10 performed by the swing control device 8S according to this embodiment.

[0141] In the first embodiment described above, the swing control unit 802 adjusts the tilt of the hydraulic pump 71 and limits the discharge amount (pump capacity) of the hydraulic oil discharged from the hydraulic pump 71, thereby limiting the swing angular velocity of the upper swing body 12. On the other hand, in this embodiment, the swing angular velocity of the upper swing body 12 is limited by adjusting the secondary pressure of the first electromagnetic proportional valve 77 and the second electromagnetic proportional valve 78 shown in FIG. 2 and adjusting the flow rate of the hydraulic oil in the control valve 73.

[0142] That is, in this embodiment, as in the first embodiment, steps S10, S20, and S30 are executed in order (FIG. 18). On the other hand, when the angular velocity setting unit 801 sets the maximum swing angular velocity (swing angular velocity limit value S1) in step S30, the swing control unit 802 inputs a proportional valve command signal to the first electromagnetic proportional valve 77 or the second electromagnetic proportional valve 78 in step S50. Specifically, the swing control unit 802 limits the secondary pressure of each proportional valve to Pi so as to correspond to the swing angular velocity limit value S1 (FIG. 16). Since there is a relationship as shown in FIG. 17 between the secondary pressures of the first electromagnetic proportional valve 77 and the second electromagnetic proportional valve 78 and the swing angular velocity of the upper swing body 12, by setting the maximum value of the electromagnetic proportional valve secondary pressure to Pi, it is possible to limit the maximum value of the swing angular velocity of the upper swing body 12 to S1, and the same effect as in the first embodiment can be obtained.

[0143] That is, in this embodiment, the swing control unit 802 inputs a forced command signal (proportional valve command signal) corresponding to the maximum swing angular velocity set by the angular velocity setting unit 801 to the first electromagnetic proportional valve 77 and the second electromagnetic proportional valve 78 of the flow rate adjustment mechanism 7T, thereby limiting the flow rate of hydraulic oil supplied from the control valve 73 of the flow rate adjustment mechanism 7T to the swing motor 72 so that the swing angular velocity of the upper swing body 12 does not exceed the maximum swing angular velocity (swing angular velocity limit value S1) regardless of the magnitude of the swing command signal output from the operation unit 81. As a result, the swing angular velocity of the upper swing body 12 can be reliably limited.

[0144] The first and third embodiments can be combined to perform suitable control. A modified example of this embodiment will be described below. Fig. 19 is a flowchart of the crane swing control executed by a swing control device 8S according to a modified example of this embodiment.

[0145] 11, due to its structure, the hydraulic pump 71 discharges hydraulic oil at a minimum capacity qmin (FIG. 11) regardless of the magnitude of the tilt command signal (even when the tilt is set to zero). In other words, the flow rate of hydraulic oil discharged from the hydraulic pump 71 generally does not become zero. In this case, the swing angular velocity Smin of the upper swing body 12 corresponding to the above-mentioned minimum capacity qmin is calculated by the following equation 5. Smin=qmin×ω_eng×Npump / (qm×Ngear) (Equation 5)

[0146] That is, when the maximum turning angular velocity (turning angular velocity limit value) set by the angular velocity setting unit 801 is smaller than the above-mentioned turning angular velocity Smin, it becomes difficult to sufficiently limit the turning angular velocity of the upper swing body 12 depending on the discharge performance of the hydraulic pump 71. To solve such a problem, in the present embodiment, as shown in FIG. 19, in step S30A, the turning control unit 802 compares the magnitude relationship between the turning angular velocity limit value S1 and the turning angular velocity Smin corresponding to the minimum capacity qmin. And when Smin < S1 (YES in step S30A), the turning control unit 802 limits the turning angular velocity of the upper swing body 12 based on the tilting of the hydraulic pump 71 as in the first embodiment (step S40). On the other hand, when Smin ≥ S1 (NO in step S30A), the turning control unit 802 limits the turning angular velocity of the upper swing body 12 based on the secondary pressure of the first electromagnetic proportional valve 77 and the second electromagnetic proportional valve 78 as in the third embodiment (step S40).

[0147] As described above, in this modification, when the discharge amount of the hydraulic pump 71 corresponding to the maximum turning angular velocity set by the angular velocity setting unit 801 is larger than the minimum discharge amount (minimum capacity qmin), the turning control unit 802 inputs a tilting command signal corresponding to the maximum turning angular velocity to the hydraulic pump 71 (tilting adjustment unit 71S), thereby restricting the discharge amount of the hydraulic oil discharged from the hydraulic pump 71 so that the turning angular velocity of the upper swing body 12 does not exceed the maximum turning angular velocity. On the other hand, when the discharge amount of the hydraulic pump 71 corresponding to the maximum turning angular velocity set by the angular velocity setting unit 801 is smaller than the minimum discharge amount, the turning control unit 802 inputs a forced command signal corresponding to the maximum turning angular velocity to the flow rate adjustment mechanism 7T (the first electromagnetic proportional valve 77, the second electromagnetic proportional valve 78), thereby restricting the flow rate of the hydraulic oil supplied from the flow rate adjustment mechanism 7T to the turning motor 72 so that the turning angular velocity of the upper swing body 12 does not exceed the maximum turning angular velocity regardless of the magnitude of the turning command signal.

[0148] Based on this control, even if there are cases where the discharge performance of the hydraulic pump 71 makes it impossible to sufficiently limit the swing angular velocity of the upper swing body 12 to the maximum swing angular velocity required by the angular velocity setting unit 801, the swing control unit 802 can reliably limit the swing angular velocity of the upper swing body 12 by inputting a forced command signal to the first electromagnetic proportional valve 77 and the second electromagnetic proportional valve 78 and adjusting their secondary pressures. Furthermore, during normal swing operation, the swing angular velocity of the upper swing body 12 can be limited without adjusting the secondary pressures of the first electromagnetic proportional valve 77 and the second electromagnetic proportional valve 78, so that the relationship between the amount by which the operator operates the operating lever 81A and the stroke amount of the control valve 73 can be maintained.

[0149] In addition, in the above third embodiment, the secondary pressure of the first electromagnetic proportional valve 77 and the second electromagnetic proportional valve 78 is adjusted to adjust the flow rate of hydraulic oil supplied from the control valve 73 to the swing motor 72, thereby limiting the swing angular velocity of the upper swing body 12. However, the swing motor 72 may be configured as a variable displacement hydraulic motor similar to the hydraulic pump 71, and the swing angular velocity of the upper swing body 12 may be limited by adjusting the capacity (tilt) of the swing motor 72.

[0150] <Fourth embodiment> Next, a crane 10 having a swing control device 8S according to a fourth embodiment of the present invention will be described. Fig. 20 is a schematic diagram of the boom 16 and jib 19 of the crane 10 equipped with the swing control device 8S according to this embodiment. Fig. 21 is a graph showing the relationship between the working radius and the load factor in the swing control performed by the swing control device 8S according to this embodiment.

[0151] In the first embodiment described above, the rotation angular velocity of the upper rotating body 12 is limited based on the length of the attachment 10S, or based on the length of the attachment 10S and the load of the suspended load. In this embodiment, the angular velocity setting unit 801 limits the rotation angular velocity of the upper rotating body 12 based on the working radius of the attachment 10S.

[0152] 20, even if the load of the load suspended from the tip of the attachment 10S (jib 18) remains the same, if the working radius R1 changes as the attachment 10S is raised and lowered (the raising and lowering angle changes), the deflection of the tip of the attachment 10S and the stress acting on the attachment 10S will change. In particular, if the attachment 10S is lowered and the working radius R1 increases, the load on the attachment 10S will increase. For this reason, in this embodiment, the swing operation information acquisition unit 800B acquires the working radius R1 in addition to the load of the suspended load as swing operation information, and sets an appropriate swing angular velocity limit value S1 for the upper swing body 12.

[0153] Specifically, as shown in Fig. 21, a preset load rate is set according to the magnitude of the load of the suspended load and the magnitude of the working radius R1. Then, the angular velocity setting unit 801 sets the rotation angular velocity limit value S1 according to the load rate. For the same load value, the larger the working radius R1, the larger the load rate, so it is desirable for the angular velocity setting unit 801 to set the rotation angular velocity limit value S1 to a smaller value.

[0154] In addition, the angular velocity setting unit 801 can easily calculate the working radius R1 using trigonometric functions from the elevation angle of the attachment 10S (boom 16, jib 18) detected by the elevation angle detection unit 66 and the length of the attachment 10S input or stored in advance.

[0155] As described above, in this embodiment, the turning operation information acquired by the turning operation information acquisition unit 800B includes information on the working radius, which is the distance from the base end to the tip end of the attachment 10S in a plan view. Then, the angular velocity setting unit 801 sets the maximum turning angular velocity based on the attachment information acquired by the attachment information acquisition unit 800A and the working radius acquired by the turning operation information acquisition unit 800B.

[0156] With this configuration, the angular velocity setting unit sets the maximum turning angular velocity based on the working radius, which can have a significant impact on the lateral load acting on the attachment 10S, thereby reliably preventing large lateral loads from being applied to the attachment 10S.

[0157] In particular, it is desirable that, for the same attachment information, the angular velocity setting unit 801 sets the maximum turning angular velocity to one turning angular velocity (fifth turning angular velocity) when the working radius R is a first working radius, and sets the maximum turning angular velocity to another turning angular velocity (sixth turning angular velocity) smaller than the one turning angular velocity when the working radius R is a second working radius larger than the first working radius. In other words, the angular velocity setting unit 801 may set the maximum turning angular velocity so that the larger the working radius R, the smaller the maximum turning angular velocity.

[0158] According to this configuration, when the attachment 10S is set to a relatively large working radius, the angular velocity setting unit 801 sets the maximum rotation angular velocity of the upper rotating body 12 to a relatively small value, thereby reliably preventing a large lateral load from being applied to the attachment 10S, which would otherwise cause damage or breakage to the attachment 10S.

[0159] Next, a modified example of this embodiment will be described. Assume that an operator simultaneously performs a swing operation and a hoisting operation of the attachment 10S during the swing operation of the upper swing body 12. For example, when the operator attempts to lower the attachment 10S (hoisting and lowering), the working radius R1 of the attachment 10S increases, and the moment acting on the attachment 10S increases accordingly, resulting in an increase in the load factor.

[0160] Therefore, when the angular velocity setting unit 801 sets the swing angular velocity limit value S1 in relation to the load factor as described above, even if the amount of operation of the swing operating lever 81A by the operator is constant, the swing angular velocity limit value S1 changes due to changes in the load factor based on the tilting operation. Therefore, while safety can be ensured, this may result in swing operations that are not intended by the operator, and may worsen operability.

[0161] For this reason, at the start of a swing operation, the angular velocity setting unit 801 may calculate a maximum load factor Load_max based on the maximum working radius Rmax (FIGS. 20 and 21) that may be operated during the subsequent swing operation and the previously detected suspended load (load value), and set the swing angular velocity limit value S1 based on this maximum load factor Load_max and the length of the attachment 10S. Note that the maximum working radius Rmax can be set by a known moment limit function (ML) provided in the control unit 80. As described above, the moment limit function is a function that limits the working radius to prevent the crane 10 from tipping over while it is operating. The maximum working radius Rmax may also be input by an operator via the input unit 82 depending on the work site and stored in the memory unit 803.

[0162] With this type of control, even if the worker performs a tilting operation on the attachment 10S during a swing operation and the working radius R1 increases, the swing angular velocity limit value S1 is set in advance based on the largest working radius Rmax, so the worker can reliably perform safe operations and prevent changes in the swing angular velocity that do not correspond to the amount of operation of the swing operating lever 81A during a swing operation, making it possible to achieve both safety and workability during swing operations.

[0163] When the working radius R1 of the attachment 10S is reduced by the operator's operation during a swing operation, the angular velocity setting unit 801 may set the swing angular velocity limit value S1 of the upper swing body 12 to a relatively large value.

[0164] As described above, in this modification, the swing operation information acquired by the swing operation information acquisition unit 800B includes, with regard to the working radius of the attachment 10S, information on the maximum working radius set in accordance with the load of the suspended load in order to prevent tipping over of the crane 10. Then, the angular velocity setting unit 801 sets the maximum swing angular velocity based on the attachment information acquired by the attachment information acquisition unit 800A and the maximum working radius (working radius Rmax) acquired by the swing operation information acquisition unit 800B.

[0165] With this configuration, when the upper rotating body 12 is rotating, the maximum rotation angular velocity can be easily set without the need to detect and reflect the current working radius using the elevation angle detection unit 66, etc. Note that the angular velocity setting unit 801 may combine the maximum working radius (working radius Rmax) as described above with the maximum suspended load, and then set the maximum rotation angular velocity in advance before the rotation operation.

[0166] As described above, in the rotation control performed by the rotation control device 8S according to this embodiment or its modified example, the angular velocity setting unit 801 may fix the rotation angular velocity limit value S1 of the upper rotating body 12 during the rotation operation, or may update it at any time.

[0167] In addition, when the angular velocity setting unit 801 sets the maximum rotation angular velocity so as to maintain the maximum rotation angular velocity during the rotation operation of the upper rotating body 12, it is possible to prevent the operator's operability from being reduced due to frequent sudden changes in the angular velocity of the upper rotating body 12.

[0168] On the other hand, the angular velocity setting unit 801 may update the maximum swing angular velocity at predetermined intervals during the swing operation of the upper swing body 12. In this case, the swing control unit 802 may control the swing drive unit 7S so that the swing angular velocity of the upper swing body 12 does not exceed the maximum swing angular velocity updated by the angular velocity setting unit 801.

[0169] According to this configuration, the maximum turning angular velocity is updated in accordance with changes in the turning information during the turning operation, thereby improving workability while ensuring safety.

[0170] In particular, the rotation operation information acquisition unit 800B acquires information regarding the working radius that changes in accordance with the raising and lowering operation of the attachment 10S during the rotation operation of the upper rotating body 12, and the angular velocity setting unit 801 can update the maximum rotation angular velocity based on the information regarding the working radius acquired by the rotation operation information acquisition unit 800B.

[0171] With this configuration, even if the working radius changes due to the hoisting operation of the attachment 10S during a swing operation, an optimal maximum swing angular velocity can be set. In particular, when the working radius decreases due to the raising operation of the attachment 10S, setting the maximum swing angular velocity to a high value makes it possible to increase the actual swing angular velocity, thereby improving workability while ensuring safety. Furthermore, when the working radius increases due to the lowering operation of the attachment 10S, further limiting the maximum swing angular velocity can ensure safety. Note that updating the maximum swing angular velocity during a swing operation is not limited to cases where the swing information is the working radius, the hoisting angle, etc., and can be applied to other embodiments as well.

[0172] Furthermore, the rotation information acquired by the rotation operation information acquisition unit 800B may include information on the boom 16 derrick angle and the jib 18 derrick angle in addition to the working radius. In this case, the angular velocity setting unit 801 can set the maximum rotation angular velocity based on at least the attachment information acquired by the attachment information acquisition unit 800A and the working radius, boom derrick angle, and jib 18 derrick angle acquired by the rotation operation information acquisition unit 800B. If the derrick angles of the boom 16 and jib 18 in FIG. 1 change, the load factor, i.e., the deflection and stability of the attachment 10S against a lateral load, will change even if the working radius R1 (FIG. 20) remains the same. For example, even if the working radius is the same, the deflection of the attachment 10S will be greater when the boom 16 derrick angle is larger (more upright) and the jib 18 derrick angle is smaller (more inverted).

[0173] Therefore, with the above configuration, even if the working radius is the same, it is possible to set an optimal maximum swing angular velocity in consideration of the fact that the resistance of the attachment 10S to lateral loads changes depending on the boom hoisting angle 16 and the jib 18. This makes it possible to perform swing operations even safer.

[0174] In the above case, it is desirable that the angular velocity setting unit 801 sets the maximum rotation angular velocity corresponding to the combination of the boom 16 hoisting angle and the jib 18 hoisting angle that maximizes the deflection of the attachment 10S due to lateral load for the same working radius.

[0175] With this configuration, even for the same working radius, the maximum swing angular velocity is set according to the conditions for the boom 16 hoisting angle and jib 18 hoisting angle that are most severe in terms of deflection, so that swing operations can be performed safely. In this case, it is desirable that appropriate maximum swing angular velocities for different combinations of working radius, boom 16 hoisting angle, and jib 18 hoisting angle be stored in advance in memory unit 803. Alternatively, for the same working radius, the maximum swing angular velocity corresponding to the combination that results in the greatest deflection may be preferentially output from memory unit 803.

[0176] Fifth Embodiment Next, a crane 10 having a swing control device 8S according to a fifth embodiment of the present invention will be described. Fig. 22 is a graph showing the transition of the detected value of the suspended load during the swing control performed by the swing control device 8S according to this embodiment. Fig. 23 is a graph showing fluctuations in the swing angular velocity of the upper swing structure 12. Fig. 24 is a graph showing the transition of the swing angular velocity of the upper swing structure 12 during the swing control performed by the swing control device 8S according to this embodiment.

[0177] When a load is lifted and the upper rotating body 12 is rotated at a work site, the load value detected by the load detection unit 67 increases from time t0 as the lifting operation is performed, as shown in Figure 22. The lifting operation generally begins after the load has completely lifted off the ground (time t1). The load value detected by the load detection unit 67 often fluctuates due to the influence of the inertia of the load and the swaying of the attachment 10S (see Figure 22).

[0178] For this reason, if the load rate (heavy load, light load) is updated based on the load detection value of the suspended load detected by the load detection unit 67 during a swing operation, the swing angular velocity limit value S1 will change from moment to moment, causing fluctuations in the swing angular velocity as shown in Fig. 23, which may result in a deterioration in operability. To solve this problem, in this embodiment, as shown in Fig. 22, the angular velocity setting unit 801 sets the swing angular velocity limit value S1 in advance using the maximum load detection value after the suspended load has been lifted off the ground and before the swing begins. According to this control, as shown in Fig. 24, the swing angular velocity limit value S1 is fixed during a swing operation, making it possible to prevent a deterioration in operability, and since the swing angular velocity limit value S1 is set using the maximum value of the detected suspended load load, safety can be fully ensured.

[0179] The maximum value of the suspended load may be determined from the maximum value of the detected value before the operation of the swing operation lever 81A. Alternatively, the worker may input the completion of lifting from the ground using a switch (not shown) or the like in the input unit 82, and the detected value of the suspended load at that time may be used as the maximum value. Furthermore, the worker may input the suspended load load (maximum value) from the input unit 82, and the load value may be stored in the memory unit 803 and referenced by the swing operation information acquisition unit 800B.

[0180] As described above, in this embodiment, the swing control device 8S further includes the load detection unit 67 that can detect the load of the suspended load. The swing operation information acquisition unit 800B sets the maximum swing angular velocity based on the load of the suspended load detected by the load detection unit 67 during the period after the suspended load has moved upward from the ground and before the swing drive unit 7S swings the upper swing body 12 in response to an operation input to the operation unit 81.

[0181] With this configuration, the maximum rotation angular velocity can be set without being affected by fluctuations in the load detection value due to the swinging of the attachment 10S or wind during the rotation operation, and the rotation operation of the upper rotating body 12 can be stably controlled.

[0182] Sixth Embodiment Next, a crane 10 having a swing control device 8S according to a sixth embodiment of the present invention will be described. In the above description, the angular velocity setting unit 801 sets the maximum swing angular velocity of the upper swing structure 12 based on the length of the attachment 10S, the load of the suspended load, the working radius, and the like. The swing information acquired by the swing operation information acquisition unit 800B may include information about the attitude of the attachment 10S (the boom 16 and the jib 18 hoisting angles). The angular velocity setting unit 801 may set the maximum swing angular velocity based on the ratio of the suspended load to the rated load, which is determined from the attachment information acquired by the attachment information acquisition unit 800A and the attachment attitude acquired by the swing operation information acquisition unit 800B. In this case, the rated load is preferably set corresponding to the maximum number of reeled main hoisting ropes 50 suspended from the tip of the attachment 10S. A typical load rating based on a moment limit function (ML) is set based on the characteristics of the attachment 10S and the hydraulic circuit. However, the rated load referred to by the angular velocity setting unit 801 does not need to take into account the characteristics of the hydraulic circuit, and therefore only the characteristics of the attachment 10S need to be taken into account. Therefore, the rated load is set based on the maximum number of loops (number of turns) of the main hoisting rope 50 that is stretched between the main hoisting point sheave 56 (FIG. 1) of the sheave block and the sheave 58 of the sheave block attached to the main load hook 57. Therefore, the maximum number of loops that can be stretched between the sheaves is used, rather than the actual number of loops of the main hoisting rope 50. In this case, the rated load can be referred to as the load factor of the actual capacity of the attached attachment 10S.

[0183] According to this embodiment, the maximum rotation angular velocity is set using the ratio of the suspended load to the rated load determined from the capacity of the attachment 10S, so that the safety and workability of the crane 10 can be achieved at the same time.

[0184] Seventh Embodiment Next, a crane 10 having a swing control device 8S according to a seventh embodiment of the present invention will be described. In each of the above embodiments, an angular velocity setting unit 801 sets a maximum swing angular velocity, and a swing control unit 802 controls a swing drive unit 7S so that the swing angular velocity of the upper swing body 12 does not exceed the maximum swing angular velocity set by the angular velocity setting unit 801. On the other hand, in this embodiment, the swing drive unit 7S is controlled in consideration of the peripheral speed of the tip of the attachment 10S during the swing operation of the upper swing body 12. Note that, because the tip of the attachment 10S is ideally located directly above the suspended load, the peripheral speed of the tip can be considered to be the peripheral speed of the suspended load.

[0185] Specifically, in this embodiment, the angular velocity setting unit 801 sets a maximum swing angular velocity when the upper swing body 12 starts to swing, as in the previous embodiment, and also calculates a maximum peripheral speed corresponding to the maximum swing angular velocity. At this time, the angular velocity setting unit 801 can calculate the maximum peripheral speed by multiplying the set maximum swing angular velocity by the working radius. Furthermore, when the upper swing body 12 starts to swing, the angular velocity setting unit 801 sets the maximum swing angular velocity during the swing operation as needed so that the peripheral speed of the tip of the attachment 10S does not exceed the maximum peripheral speed during the swing operation.

[0186] According to this configuration, the maximum swing angular velocity during a swing operation is set so that the peripheral speed of the tip of the attachment 10S, i.e., the suspended load, does not exceed the maximum peripheral speed. Therefore, because the maximum peripheral speed is controlled to be constant during a swing operation, the maximum value of the suspended load speed does not change even when the working radius changes, improving the workability of the swing operation. Note that if the attachment 10S is lowered during a swing operation, the working radius increases, and the peripheral speed of the suspended load increases. Therefore, the control according to this embodiment limits the swing angular velocity so that the peripheral speed of the suspended load does not exceed the maximum peripheral speed. From the perspective of an operator in the cab 15 (FIG. 1), even if the swing angular velocity of a suspended load located farther away decreases, the operator will not feel any discomfort in the movement speed of the suspended load as long as the peripheral speed does not change significantly. Therefore, according to the control according to this embodiment, even if the swing angular velocity decreases as the attachment 10S is lowered, safety can be ensured without a significant decrease in workability.

[0187] Eighth Embodiment Next, a crane 10 having a swing control device 8S according to an eighth embodiment of the present invention will be described. In the above embodiments, the angular velocity setting unit 801 sets the maximum swing angular velocity, and the swing control unit 802 controls the swing drive unit 7S so that the swing angular velocity of the upper swing body 12 does not exceed the maximum swing angular velocity set by the angular velocity setting unit 801. In contrast, in this embodiment, an operator can input an effective maximum swing angular velocity, with the maximum swing angular velocity set by the angular velocity setting unit 801 as the maximum value, through the input unit 82 (FIG. 3). The swing control unit 802 then controls the swing drive unit 7S so that the swing angular velocity of the upper swing body 12 does not exceed the effective maximum swing angular velocity input to the input unit 82. As an example, if the maximum swing angular velocity set by the angular velocity setting unit 801 is 1.0 (rpm), the operator can manually input the effective maximum swing angular velocity through the input unit 82, with this angular velocity as the maximum. In this case as well, the maximum value of the rotation angular velocity of the upper rotating body 12 corresponds to the maximum rotation angular velocity set by the angular velocity setting unit 801 .

[0188] With this configuration, the worker can further limit the maximum rotation angular velocity according to his or her own ability and preference, thereby enabling the worker to perform rotation operations more safely.

[0189] In the above configuration, the input unit 82 may be configured to enable selection of the effective maximum turning angular velocity in stages. Specifically, three switches, Low, Middle, and High, are arranged inside the cab 15 as part of the input unit 82 for setting the turning angular velocity. In this case, the High switch corresponds to the maximum turning angular velocity (100%) set by the angular velocity setting unit 801. Meanwhile, the Low switch corresponds to 60% of the maximum turning angular velocity, and the Middle switch corresponds to 80% of the maximum turning angular velocity. The form of each switch and the ratio to the maximum turning angular velocity are not limited to these.

[0190] According to the above configuration, the worker can select the effective maximum rotation angular velocity in stages depending on the strength, type, etc. of the suspended load, thereby enabling the rotation operation to be performed more safely.

[0191] The above describes the swing control device 8S and the crane 10 equipped with the same according to each embodiment of the present invention. In this crane 10, the swing drive unit 7S is controlled so that the swing angular velocity of the upper swing structure 12 does not exceed at least the maximum swing angular velocity set in accordance with the attachment information for the attachment 10S. The attachment information is information for setting the maximum swing angular velocity, and the angular velocity setting unit 801 sets the maximum swing angular velocity for the swing operation of the upper swing structure 12 in accordance with the attachment information. This enables stable swing operation while preventing the attachment 10S from being damaged or broken due to a large lateral load being applied to the attachment 10S based on the swing operation of the operator. Note that the present invention is not limited to these embodiments. The present invention can take the following modified embodiments, for example.

[0192] (1) In the above embodiment, the crane 10 shown in FIG. 1 has been described, but the present invention is not limited thereto. FIG. 25 is a side view of a crane 10 equipped with a swing control device 8S according to a modified embodiment of the present invention. In this modified embodiment, the crane 10 does not include a jib 18 (FIG. 1), and a load is lifted by a main hoisting rope 50 (load rope) hanging from the tip of the boom 16 (attachment 10S). In this case, the attachment information acquisition unit 800A acquires information such as the length of the boom 16 as attachment information, and the angular velocity setting unit 801 sets the swing angular velocity limit value S1 for the swing operation of the upper swing body 12 in accordance with the attachment information. Furthermore, in the first embodiment, only the length of the jib 18 of the attachment 10S may be acquired as attachment information.

[0193] (2) The crane 10 shown in Fig. 1 may not have the rear strut 21 or the front strut 22, or may have only one strut. The structure of the mast supporting the boom 16 is not limited to that shown in Fig. 1, and may have other mast structures or a gantry structure (not shown).

[0194] (3) In addition, in each of the above embodiments, the attachment information acquired by the attachment information acquisition unit 800A is described using length information of the attachment 10S. However, the present invention is not limited to this. The attachment information may include information that serves as an index of strength against lateral loads, such as the rigidity, strength, cross-sectional structure, and material properties of the attachment 10S (boom 16, jib 18, etc.). In this case, if the index of strength is large, the angular velocity setting unit 801 may set the swing angular velocity limit value S1 relatively large. The attachment information may also include the number of years of use of the attachment 10S (the number of years elapsed since the date of manufacture) and the number of times the attachment 10S has been attached to and detached from the upper rotating body 12. The angular velocity setting unit 801 may set the swing angular velocity limit value S1 relatively small as the number of years and the number of times increase.

[0195] (4) Furthermore, the swing operation information acquired by the swing operation information acquisition unit 800B is not limited to the load of the suspended load and the working radius (hoisting angle). The swing operation information may include other information, such as wind speed at the work site, that affects the swing of the suspended load, the swing of the attachment 10S, the lateral load acting on the attachment 10S, and stress.

[0196] (5) In the above embodiments, the swing angular velocity limit value S1 of the upper swing body 12 is set based on various information input from the input unit 82 and information (such as a limit value map) stored in the memory unit 803. However, the present invention is not limited to this. When the unique information and identification information of the attachment 10S are known, the angular velocity setting unit 801 may set the maximum swing angular velocity (swing angular velocity limit value S1) based on the information and a pre-prepared calculation formula. Furthermore, at least a portion of the control unit 80, including the attachment information acquisition unit 800A, the swing operation information acquisition unit 800B, and the angular velocity setting unit 801, may not be mounted on the crane 10 but may be located at a remote control station. In this case, the swing angular velocity limit value S1 may be transmitted from the station to the crane 10 (control unit 80) using a communication device such as a wireless device. Furthermore, a control unit 80 (attachment information acquisition unit 800A, swing operation information acquisition unit 800B, angular velocity setting unit 801) and the like may be provided in an operation device (not shown) held by an operator around the crane 10. Furthermore, what is input from the operation unit 81 may be the model number (serial number) of the attachment 20S, and the attachment information acquisition unit 800A may acquire length information corresponding to that model number from the memory unit 803.

[0197] (6) In the first embodiment, the swing control unit 802 adjusts the tilt of the hydraulic pump 71 and limits the discharge rate (pump capacity) of hydraulic oil discharged from the hydraulic pump 71, thereby limiting the swing angular velocity of the upper swing structure 12. In the third embodiment, the swing angular velocity of the upper swing structure 12 is limited by adjusting the secondary pressure of the first electromagnetic proportional valve 77 and the second electromagnetic proportional valve 78 shown in FIG. 2 and adjusting the flow rate of hydraulic oil in the control valve 73. The present invention is not limited to this. That is, the swing control unit 802 may input a rotation speed command signal corresponding to the maximum swing angular velocity set by the angular velocity setting unit 801 to the engine 70, thereby limiting the rotation speed of the engine 70 so that the swing angular velocity of the upper swing structure 12 does not exceed the maximum swing angular velocity. The engine 70 includes an engine body and an engine controller. The engine controller receives the rotation speed command signal and rotates the output shaft of the engine body with a fuel injection amount corresponding to the rotation speed command signal.

[0198] With this configuration, the rotation control unit 802 limits the rotation speed of the engine 70, which is the driving source located most upstream, so that the rotation angular velocity of the upper rotating body 12 does not exceed the maximum rotation angular velocity, thereby reliably limiting the rotation angular velocity of the upper rotating body 12. [Explanation of symbols]

[0199] 10 Crane 10S Attachment 12 Upper rotating body 14 Lower running body (lower body) 15 Cab 16. Boom 18 Jib 20 Mast 30 Boom hoisting winch 32 Jib hoisting winch 34 Main winch 36 Auxiliary winch 38 Boom hoisting rope 44 Jib hoisting rope 50 Main winding rope 57 Main Hook 66 Elevation angle detection unit 67 Load detection unit 70 Engine 71 Hydraulic pump 71S tilt adjustment part 72 Swing motor 73 Control Valve 74 Relief valve 75 Engine speed detector 76 Turning angular velocity detection unit 77 1st solenoid proportional valve 78 Second solenoid proportional valve 7S Swivel drive unit 7T flow adjustment mechanism 80 Control Unit 800A Attachment Information Acquisition Unit 800B Turning operation information acquisition unit 801 Angular velocity setting section 802 Swivel control unit 803 Storage section 81 Operation section 82 Input section 8S turning control device CL central axis of rotation

Claims

1. A lower body and an upper rotating body supported by the lower body so as to be rotatable about a rotation center axis extending in the vertical direction relative to the lower body; an operating unit that receives an operation for rotating the upper rotating body relative to the lower main body and outputs a rotation command signal corresponding to the magnitude of the operation; a rotation drive unit capable of rotating the upper rotating body relative to the lower main body; an attachment detachable from the upper rotating body, the attachment including a base end portion rotatably supported on the upper rotating body in a hoisting direction and a tip end portion opposite to the base end portion; a lifting rope suspended from the tip of the attachment and connected to a lifting load; A crane swing control device used for a crane having an attachment information acquisition unit that acquires attachment information, the attachment information being information specific to an attachment for setting a maximum swing angular velocity that is a maximum value of the swing angular velocity based on a lateral load that is a load along the swing direction of the upper swing body that acts on the attachment due to the swing angular velocity of the upper swing body; a swing control unit that receives the swing command signal output from the operation unit and controls the swing drive unit so that the upper swing body swings relative to the lower main body in response to the swing command signal; an angular velocity setting unit that sets the maximum swing angular velocity allowed in a swing operation of the upper swing body based on at least the attachment information acquired by the attachment information acquisition unit; a storage unit that stores a limit value of the maximum turning angular velocity for the attachment information, each limit value of the maximum swing angular velocity for the attachment information stored in the storage unit is set to the smaller of a swing angular velocity corresponding to an allowable value of a runout of the attachment and a swing angular velocity corresponding to an allowable value of a stress of the attachment; the angular velocity setting unit refers to the limit value stored in the storage unit based on at least the attachment information acquired by the attachment information acquisition unit, and sets the maximum swing angular velocity allowed in the swing operation of the upper swing body; the rotation control unit controls the rotation drive unit so that the rotation angular velocity of the upper rotating body does not exceed the maximum rotation angular velocity set by the angular velocity setting unit. Crane rotation control device.

2. the attachment information includes a length of the attachment from the base end to the tip end, The crane swing control device according to claim 1 , wherein the angular velocity setting unit sets the maximum swing angular velocity so that the maximum swing angular velocity decreases as the length of the attachment increases.

3. a turning information acquisition unit that acquires turning information, the turning information being information related to a condition of the turning operation for setting the maximum turning angular velocity; 3. The crane rotation control device according to claim 1, wherein the angular velocity setting unit sets the maximum rotation angular velocity based on the attachment information acquired by the attachment information acquisition unit and the rotation information acquired by the rotation information acquisition unit.

4. the rotation information includes information corresponding to a suspended load, which is the load of a suspended load connected to the suspending rope, 4. The crane swing control device according to claim 3, wherein the angular velocity setting unit sets the maximum swing angular velocity based on at least the attachment information acquired by the attachment information acquisition unit and the suspended load load acquired by the swing information acquisition unit.

5. The crane swing control device according to claim 4 , wherein the angular velocity setting unit sets the maximum swing angular velocity so that the maximum swing angular velocity decreases as the suspended load increases for the same attachment information.

6. Further, a load detection unit capable of detecting the load of the suspended load is provided, 6. The crane rotation control device according to claim 4 or 5, wherein the angular velocity setting unit sets the maximum rotation angular velocity based on the suspended load load detected by the load detection unit during a period after the suspended load has moved upward from the ground and before the rotation drive unit rotates the upper rotating body in response to the operation input to the operation unit.

7. The rotation information acquired by the rotation information acquisition unit includes information regarding a predetermined maximum suspended load load, which is a maximum load of a suspended load connected to the suspension rope, 6. The crane swing control device according to claim 4, wherein the angular velocity setting unit sets the maximum swing angular velocity based on the attachment information acquired by the attachment information acquisition unit and the maximum suspended load.

8. A lower body, an upper rotating body supported by the lower body so as to be rotatable about a rotation center axis extending in the vertical direction relative to the lower body; an operating unit that receives an operation for rotating the upper rotating body relative to the lower main body and outputs a rotation command signal corresponding to the magnitude of the operation; a rotation drive unit capable of rotating the upper rotating body relative to the lower main body; an attachment detachable from the upper rotating body, the attachment including a base end portion rotatably supported on the upper rotating body in a hoisting direction and a tip end portion opposite to the base end portion; a lifting rope suspended from the tip of the attachment and connected to a lifting load; A crane swing control device used for a crane having an attachment information acquisition unit that acquires attachment information, the attachment information being information specific to the attachment for setting a maximum swing angular velocity that is a maximum value of the swing angular velocity based on a lateral load that is a load along the swing direction of the upper swing body that acts on the attachment due to the swing angular velocity of the upper swing body; an angular velocity setting unit that sets the maximum swing angular velocity allowed in a swing operation of the upper swing body based on at least the attachment information acquired by the attachment information acquisition unit; a rotation control unit that receives the rotation command signal output from the operation unit and controls the rotation drive unit so that the upper rotating body rotates relative to the lower main body in response to the rotation command signal, and controls the rotation drive unit so that the rotation angular velocity of the upper rotating body does not exceed the maximum rotation angular velocity set by the angular velocity setting unit; a turning information acquisition unit that acquires turning information, the turning information being information related to a condition of the turning operation for setting the maximum turning angular velocity; the angular velocity setting unit sets the maximum turning angular velocity based on the attachment information acquired by the attachment information acquisition unit and the turning information acquired by the turning information acquisition unit; the rotation information includes information corresponding to a suspended load, which is the load of a suspended load connected to the suspending rope, the angular velocity setting unit sets the maximum rotation angular velocity based on at least the attachment information acquired by the attachment information acquisition unit and the suspended load load acquired by the rotation information acquisition unit; the turning information includes information regarding the attitude of the attachment, the angular velocity setting unit sets the maximum rotation angular velocity based on a ratio of the suspended load load to a rated load determined from the attachment information acquired by the attachment information acquisition unit and the attitude of the attachment acquired by the rotation information acquisition unit; and A crane rotation control device, wherein the rated load is set corresponding to the maximum number of hooks of the load rope hanging down from the tip of the attachment.

9. 9. The crane rotation control device according to claim 4, wherein the angular velocity setting unit sets the maximum rotation angular velocity at the start of a rotation operation of the upper rotating body, and maintains the set maximum rotation angular velocity during the rotation operation.

10. the angular velocity setting unit updates the maximum swing angular velocity at predetermined intervals during a swing operation of the upper swing body, 9. The crane rotation control device according to claim 3, wherein the rotation control unit controls the rotation drive unit so that the rotation angular velocity of the upper rotating body does not exceed the maximum rotation angular velocity updated by the angular velocity setting unit.

11. The turning information acquired by the turning information acquisition unit includes information about a working radius, which is a distance from the base end to the tip end of the attachment in a plan view, 9. The crane swing control device according to claim 3, wherein the angular velocity setting unit sets the maximum swing angular velocity based on at least the attachment information acquired by the attachment information acquisition unit and the working radius acquired by the swing information acquisition unit.

12. The crane swing control device according to claim 11, wherein the angular velocity setting unit sets the maximum swing angular velocity so that the larger the working radius is, the smaller the maximum swing angular velocity is, for the same attachment information.

13. the attachment includes a boom including the base end portion and supported by the upper rotating body so as to be rotatable in a hoisting direction, and a jib including the tip end portion and supported by the boom so as to be rotatable in the hoisting direction, The rotation information further includes information regarding a boom hoisting angle and a jib hoisting angle, 13. The crane swing control device according to claim 11, wherein the angular velocity setting unit sets the maximum swing angular velocity based on at least the attachment information acquired by the attachment information acquisition unit and the working radius, boom hoisting angle, and jib hoisting angle acquired by the swing information acquisition unit.

14. A lower body, an upper rotating body supported by the lower body so as to be rotatable about a rotation center axis extending in the vertical direction relative to the lower body; an operating unit that receives an operation for rotating the upper rotating body relative to the lower main body and outputs a rotation command signal corresponding to the magnitude of the operation; a rotation drive unit capable of rotating the upper rotating body relative to the lower main body; an attachment detachable from the upper rotating body, the attachment including a base end portion rotatably supported on the upper rotating body in a hoisting direction and a tip end portion opposite to the base end portion; a lifting rope suspended from the tip of the attachment and connected to a lifting load; A crane swing control device used for a crane having an attachment information acquisition unit that acquires attachment information, the attachment information being information specific to the attachment for setting a maximum swing angular velocity that is a maximum value of the swing angular velocity based on a lateral load that is a load along the swing direction of the upper swing body that acts on the attachment due to the swing angular velocity of the upper swing body; an angular velocity setting unit that sets the maximum swing angular velocity allowed in a swing operation of the upper swing body based on at least the attachment information acquired by the attachment information acquisition unit; a rotation control unit that receives the rotation command signal output from the operation unit and controls the rotation drive unit so that the upper rotating body rotates relative to the lower main body in response to the rotation command signal, and controls the rotation drive unit so that the rotation angular velocity of the upper rotating body does not exceed the maximum rotation angular velocity set by the angular velocity setting unit; a turning information acquisition unit that acquires turning information, the turning information being information related to a condition of the turning operation for setting the maximum turning angular velocity; the angular velocity setting unit sets the maximum turning angular velocity based on the attachment information acquired by the attachment information acquisition unit and the turning information acquired by the turning information acquisition unit; The turning information acquired by the turning information acquisition unit includes information about a working radius, which is a distance from the base end to the tip end of the attachment in a plan view, the angular velocity setting unit sets the maximum turning angular velocity based on at least the attachment information acquired by the attachment information acquisition unit and the working radius acquired by the turning information acquisition unit; the attachment includes a boom including the base end portion and supported by the upper rotating body so as to be rotatable in a hoisting direction, and a jib including the tip end portion and supported by the boom so as to be rotatable in the hoisting direction, The rotation information further includes information regarding a boom hoisting angle and a jib hoisting angle, the angular velocity setting unit sets the maximum swing angular velocity based on at least the attachment information acquired by the attachment information acquisition unit and the working radius, boom hoisting angle, and jib hoisting angle acquired by the swing information acquisition unit; a crane rotation control device in which the angular velocity setting unit sets the maximum rotation angular velocity in accordance with a combination of the boom hoisting angle and the jib hoisting angle that maximizes the deflection of the attachment due to the lateral load for the same working radius;

15. the rotation information includes, with respect to the working radius, information on a maximum working radius set in accordance with the load of a suspended load in order to prevent the crane from tipping over, 13. The crane swing control device according to claim 11, wherein the angular velocity setting unit sets the maximum swing angular velocity based on the attachment information acquired by the attachment information acquisition unit and the maximum working radius acquired by the swing information acquisition unit.

16. The crane swing control device according to claim 15, wherein the angular velocity setting unit sets the maximum swing angular velocity at the start of a swing operation of the upper swing body, and maintains the set maximum swing angular velocity during the swing operation.

17. the angular velocity setting unit updates the maximum swing angular velocity at predetermined intervals during a swing operation of the upper swing body, 15. The crane rotation control device according to claim 11, wherein the rotation control unit controls the rotation drive unit so that the rotation angular velocity of the upper rotating body does not exceed the maximum rotation angular velocity updated by the angular velocity setting unit.

18. the swing information acquisition unit acquires information about the working radius that changes in accordance with the raising and lowering operation of the attachment during the swing operation of the upper swing body, The crane swing control device according to claim 17, wherein the angular velocity setting unit updates the maximum swing angular velocity based on the information on the working radius acquired by the swing information acquisition unit.

19. 4. The crane rotation control device according to claim 1, wherein the angular velocity setting unit sets the maximum rotation angular velocity at the start of a rotation operation of the upper rotating body, and further calculates a maximum circumferential speed corresponding to the maximum rotation angular velocity, and sets the maximum rotation angular velocity during the rotation operation of the upper rotating body so that the circumferential speed of the tip end of the attachment does not exceed the maximum circumferential speed during the rotation operation.

20. an input unit that allows an operator to input an effective maximum swing angular velocity having the maximum swing angular velocity set by the angular velocity setting unit as a maximum value; 4. The crane rotation control device according to claim 1, wherein the rotation control unit controls the rotation drive unit so that the rotation angular velocity of the upper rotating body does not exceed the effective maximum rotation angular velocity input to the input unit.

21. The crane swing control device according to claim 20, wherein the input unit is configured to enable the effective maximum swing angular velocity to be selected in stages.

22. The slewing drive unit of the crane is an engine having an output shaft; a variable displacement hydraulic pump that is connected to the output shaft and discharges hydraulic oil using power input from the output shaft, and that is capable of receiving an input of a tilt command signal and changing a maximum discharge amount of hydraulic oil in accordance with the magnitude of the tilt command signal; a hydraulic swing motor that includes a plurality of hydraulic chambers therein, receives hydraulic oil supplied from the hydraulic pump into one of the plurality of hydraulic chambers, and discharges hydraulic oil from the other hydraulic chambers of the plurality of hydraulic chambers, thereby generating a driving force for swinging the upper swing body; a flow rate adjusting mechanism including a control valve disposed between the hydraulic pump and the swing motor, which adjusts the flow rate of hydraulic oil discharged from the hydraulic pump and supplied to the swing motor in response to the swing command signal output from the operating unit; and 22. The crane rotation control device according to claim 1, wherein the rotation control unit inputs a tilt command signal corresponding to the maximum rotation angular velocity set by the angular velocity setting unit to the hydraulic pump, thereby limiting the discharge amount of hydraulic oil discharged from the hydraulic pump so that the rotation angular velocity of the upper rotating body does not exceed the maximum rotation angular velocity.

23. A lower body, an upper rotating body supported by the lower body so as to be rotatable about a rotation center axis extending in the vertical direction relative to the lower body; an operating unit that receives an operation for rotating the upper rotating body relative to the lower main body and outputs a rotation command signal corresponding to the magnitude of the operation; a rotation drive unit capable of rotating the upper rotating body relative to the lower main body; an attachment detachable from the upper rotating body, the attachment including a base end portion rotatably supported on the upper rotating body in a hoisting direction and a tip end portion opposite to the base end portion; a lifting rope suspended from the tip of the attachment and connected to a lifting load; A crane swing control device used for a crane having an attachment information acquisition unit that acquires attachment information, the attachment information being information specific to the attachment for setting a maximum swing angular velocity that is a maximum value of the swing angular velocity based on a lateral load that is a load along the swing direction of the upper swing body that acts on the attachment due to the swing angular velocity of the upper swing body; an angular velocity setting unit that sets the maximum swing angular velocity allowed in a swing operation of the upper swing body based on at least the attachment information acquired by the attachment information acquisition unit; a rotation control unit that receives the rotation command signal output from the operation unit and controls the rotation drive unit so that the upper rotating body rotates relative to the lower main body in response to the rotation command signal, and controls the rotation drive unit so that the rotation angular velocity of the upper rotating body does not exceed the maximum rotation angular velocity set by the angular velocity setting unit; The slewing drive unit of the crane is an engine having an output shaft; a variable displacement hydraulic pump that is connected to the output shaft and discharges hydraulic oil using power input from the output shaft, and that is capable of receiving an input of a tilt command signal and changing a maximum discharge amount of hydraulic oil in accordance with the magnitude of the tilt command signal; a hydraulic swing motor that includes a plurality of hydraulic chambers therein, receives hydraulic oil supplied from the hydraulic pump into one of the plurality of hydraulic chambers, and discharges hydraulic oil from the other hydraulic chambers of the plurality of hydraulic chambers, thereby generating a driving force for swinging the upper swing body; a flow rate adjusting mechanism including a control valve disposed between the hydraulic pump and the swing motor, which adjusts the flow rate of hydraulic oil discharged from the hydraulic pump and supplied to the swing motor in response to the swing command signal output from the operating unit; and the swing control unit inputs a tilt command signal corresponding to the maximum swing angular velocity set by the angular velocity setting unit to the hydraulic pump, thereby limiting the discharge amount of hydraulic oil discharged from the hydraulic pump so that the swing angular velocity of the upper swing body does not exceed the maximum swing angular velocity; the hydraulic pump discharges hydraulic oil at a minimum discharge rate greater than zero; The turning control unit is When the discharge amount of the hydraulic pump corresponding to the maximum swing angular velocity set by the angular velocity setting unit is larger than the minimum discharge amount, a tilt command signal corresponding to the maximum swing angular velocity is input to the hydraulic pump, thereby limiting the discharge amount of hydraulic oil discharged from the hydraulic pump so that the swing angular velocity of the upper swing body does not exceed the maximum swing angular velocity; A crane rotation control device that, when the discharge rate of the hydraulic pump corresponding to the maximum rotation angular velocity set by the angular velocity setting unit is smaller than the minimum discharge rate, limits the flow rate of hydraulic oil supplied from the flow rate adjustment mechanism to the rotation motor so that the rotation angular velocity of the upper rotating body does not exceed the maximum rotation angular velocity regardless of the magnitude of the rotation command signal by inputting a forced command signal corresponding to the maximum rotation angular velocity to the flow rate adjustment mechanism.

24. The slewing drive unit of the crane is an engine having an output shaft; a hydraulic pump connected to the output shaft and configured to discharge hydraulic oil by power input from the output shaft; a hydraulic swing motor that includes a plurality of hydraulic chambers therein, receives hydraulic oil supplied from the hydraulic pump into one of the plurality of hydraulic chambers, and discharges hydraulic oil from the other hydraulic chambers of the plurality of hydraulic chambers, thereby generating a driving force for swinging the upper swing body; a flow rate adjusting mechanism including a control valve disposed between the hydraulic pump and the swing motor, which adjusts the flow rate of hydraulic oil discharged from the hydraulic pump and supplied to the swing motor in response to the swing command signal output from the operating unit; and 22. A crane rotation control device according to any one of claims 1 to 21, wherein the rotation control unit inputs a forced command signal corresponding to the maximum rotation angular velocity set by the angular velocity setting unit to the flow rate adjustment mechanism, thereby limiting the flow rate of hydraulic oil supplied from the flow rate adjustment mechanism to the rotation motor so that the rotation angular velocity of the upper rotating body does not exceed the maximum rotation angular velocity regardless of the magnitude of the rotation command signal.

25. The slewing drive unit of the crane is an engine having an output shaft; a hydraulic pump connected to the output shaft and configured to discharge hydraulic oil by power input from the output shaft; a hydraulic swing motor that includes a plurality of hydraulic chambers therein, receives hydraulic oil supplied from the hydraulic pump into one of the plurality of hydraulic chambers, and discharges hydraulic oil from the other hydraulic chambers of the plurality of hydraulic chambers, thereby generating a driving force for swinging the upper swing body; a flow rate adjusting mechanism including a control valve disposed between the hydraulic pump and the swing motor, which adjusts the flow rate of hydraulic oil discharged from the hydraulic pump and supplied to the swing motor in response to the swing command signal output from the operating unit; and The crane swing control device according to any one of claims 1 to 21, wherein the swing control unit limits the rotation speed of the engine so that the swing angular velocity of the upper swing body does not exceed the maximum swing angular velocity.

26. A lower body and an upper rotating body supported by the lower body so as to be rotatable about a rotation center axis extending in the vertical direction relative to the lower body; an operating unit that receives an operation for rotating the upper rotating body relative to the lower main body and outputs a rotation command signal corresponding to the magnitude of the operation; a rotation drive unit capable of rotating the upper rotating body relative to the lower main body; an attachment detachable from the upper rotating body, the attachment including a base end portion rotatably supported on the upper rotating body in a hoisting direction and a tip end portion opposite to the base end portion; a lifting rope suspended from the tip of the attachment and connected to a lifting load; a swing control device according to any one of claims 1 to 25, which controls the swing drive unit so that the swing angular velocity of the upper swing body does not exceed at least a maximum swing angular velocity set in accordance with attachment information of the attachment; A crane equipped with:

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