JP2018070321A - crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crane capable of suppressing periodic swing which is inherent to a conveying object even if the swing state of the conveying object is varied by disturbances resulting from wind and the like.SOLUTION: In a crane 1, a right revolving oil passage 27 serving as one oil supply/exhaust path through which a hydraulic oil is supplied from a hydraulic pump 21 when a hydraulic revolving motor 17 of a revolving base 7 provided with a telescopic boom 8 is turned to the right, which is one direction, is communicated with a left revolving oil passage 28 serving as the other oil supply/exhaust path through which a hydraulic oil is supplied from the hydraulic pump 21 when the revolving motor 17 is turned to the left, which is the other direction, via a right free revolving relief valve 29 and a left free revolving relief valve 30 serving as on-off valves. When the communication between the right revolving oil passage 27 and the left revolving oil passage 28 and the hydraulic pump 21 is blocked, the right free revolving relief valve 29 and the left free revolving relief valve 30 are opened or closed in accordance with variations in hydraulic pressure of the right revolving oil passage 27 and the left revolving oil passage 28.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a crane. Specifically, the present invention relates to crane turning control.

  Conventionally, in a crane, when a lifted transported object is moved by turning a swivel base and stopped at a target position, the transported object has a specific cycle determined by its weight, the length of the wire rope, etc. A swinging pendulum motion occurs. Therefore, the crane calculates the swing state of the transport object based on the weight of the transport object, the swing angle of the wire rope, the wire rope length, the boom state, etc., and moves the tip of the telescopic boom to move the transport object. A crane equipped with a steady rest device that suppresses the swing is known. It is like Patent Document 1.

  The crane described in Patent Document 1 calculates the position of the tip of the telescopic boom and the position of the transported object from the swing angle of the wire rope detected by the swing angle detection means, the length of the wire rope, the length of the telescopic boom, the posture, and the like. To do. Then, the crane rotates the swivel base or raises and lowers the telescopic boom so that the calculated tip position of the telescopic boom matches the position of the conveyed product. As described above, the crane is configured to cancel the vibration of the conveyed object by eliminating the swing angle of the wire rope by moving the tip of the telescopic boom supporting the conveyed object in the vibration direction of the conveyed object.

  In the technique described in Patent Document 1, the calculation of the position of the telescopic boom tip and the position of the transported object and the operation of the hydraulic motor of the swivel and the hoisting cylinder of the telescopic boom are performed simultaneously and continuously in order to cancel the shake of the transported object. Must be implemented. For this reason, in the case of the crane, if the mode of the swing of the conveyed product changes due to the influence of wind or the like, the control of the hydraulic motor and the hoisting cylinder may be shifted, and the effect of suppressing the swing of the conveyed product may be limited. was there.

JP 2008-74579 A

  An object of the present invention is to provide a crane capable of suppressing a period fluctuation inherent in a conveyed object even if a change in the state of the conveyed object due to disturbance such as wind occurs.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, when the hydraulic swing motor of the swivel base provided with the telescopic boom is rotated in one direction, one supply / discharge oil passage to which hydraulic oil is supplied from the hydraulic pump and the swing motor are rotated in the other direction. The other supply / discharge oil passage to which hydraulic oil is supplied from the hydraulic pump is communicated via an on-off valve, and the one supply / discharge oil passage and the other supply / discharge oil passage When the communication between the hydraulic pump and the hydraulic pump is interrupted, the on-off valve is opened and closed according to fluctuations in the hydraulic pressure of the one supply / discharge oil passage and the hydraulic pressure of the other supply / discharge oil passage.

  The crane has a vibration frequency inherent to the conveyed object from the hydraulic waveform of the one supply / discharge oil path and the other supply / discharge oil path caused by the vibration of the conveyed object suspended from the telescopic boom. A resonance hydraulic pressure waveform is extracted, and the on-off valve is opened and closed based on the resonance hydraulic pressure waveform.

  In the crane, when the hydraulic pressure of the resonance hydraulic waveform is higher than a reference value, the on-off valve is opened for a predetermined time determined within a half cycle of the resonant hydraulic waveform.

  In the crane, when the oil pressure of the resonance oil pressure waveform is higher than a reference value, the on-off valve is opened for a valve opening time set in accordance with the direction of shaking of the conveyed object.

  The present invention has the following effects.

  In the crane, the holding state of the swivel base is switched based on the reaction force of the swaying of the conveyed object without using a wire rope deflection angle sensor or the like. Thereby, even if disturbances such as winds affect the state of shake of the conveyed product, it is possible to suppress the fluctuation of the period inherent to the conveyed product.

  In the crane, the holding state of the position of the swivel base is switched based on the vibration frequency inherent to the conveyed object without using a wire rope deflection angle sensor or the like. Thereby, even if disturbances such as wind affect the state of shake of the conveyed product, it is possible to suppress the fluctuation of the period inherent to the conveyed product.

  In the crane, the holding state of the position of the swivel base is switched based on the hydraulic pressure of the resonance hydraulic waveform that fluctuates at the swing frequency unique to the conveyed object without using a wire rope deflection angle sensor or the like. Thereby, even if disturbances such as wind affect the state of shake of the conveyed product, it is possible to suppress the fluctuation of the period inherent to the conveyed product.

  In the crane, the holding state of the position of the swivel base is switched under optimum conditions according to the conveyance state, posture, weight of the conveyed object, and the like. Thereby, even if disturbances such as wind affect the state of shake of the conveyed product, it is possible to suppress the fluctuation of the period inherent to the conveyed product.

The side view which shows the whole structure of the crane which concerns on 1st embodiment of this invention. The figure which shows the hydraulic circuit for turning of the crane which concerns on 1st embodiment of this invention. The figure which shows the structure of the control apparatus of the crane which concerns on 1st embodiment of this invention. (A) The schematic diagram which shows the pendulum motion of the conveyed product at the time of the turning stop of the crane which concerns on 1st embodiment of this invention, (b) The figure which shows the graph showing the change of the hydraulic pressure of the turning motor similarly at the time of a pendulum motion. The figure which shows the graph showing the hydraulic pressure waveform and resonance hydraulic pressure waveform which were synthesize | combined in the control apparatus of the crane which concerns on 1st embodiment of this invention. The figure showing the graph which shows the opening-and-closing timing of the resonance hydraulic pressure waveform and the opening / closing valve for free turning operation in the crane which concerns on 1st embodiment of this invention. The schematic diagram which shows the change of the pendulum motion of a conveyed product in the state by which the swivel base was freely swung rightward in the crane which concerns on 1st embodiment of this invention, (b) After a swivel base is similarly free swirled rightward The schematic diagram which shows the change of the pendulum motion of the conveyed product in the state rotated free leftward. The figure showing the graph which shows the opening-closing timing of the resonance hydraulic pressure waveform in another embodiment of the crane which concerns on 1st embodiment of this invention, and the on-off valve for free rotation operations. The figure which shows the flowchart showing the control aspect of anti-sway control in the crane which concerns on another embodiment of 1st embodiment of this invention. The figure showing the graph which shows the opening-and-closing timing of the resonance hydraulic pressure waveform and the opening / closing valve for free turning operation in the crane which concerns on 2nd embodiment of this invention.

  Below, the crane 1 which concerns on one Embodiment of a crane is demonstrated using FIGS. 1-3. In the present embodiment, a mobile crane will be described as the crane 1. However, the crane 1 includes the telescopic boom 8 that is raised and lowered by the actuator, the swivel base 7, and the winch (main winch 13 and sub winch 15). I just need it.

  As shown in FIG. 1, the crane 1 is a mobile crane 1 that can move to an unspecified location. The crane 1 has a vehicle 2 and a crane device 6.

  The vehicle 2 conveys the crane device 6. The vehicle 2 has a plurality of wheels 3 and travels using an engine 4 (see FIG. 2) as a power source. The vehicle 2 is provided with an outrigger 5. The outrigger 5 includes a projecting beam that can be extended by hydraulic pressure on both sides in the width direction of the vehicle 2 and a hydraulic jack cylinder that can extend in a direction perpendicular to the ground. The vehicle 2 can extend the workable range of the crane 1 by extending the outrigger 5 in the width direction of the vehicle 2 and grounding the jack cylinder.

  The crane apparatus 6 lifts the conveyed product W with a wire rope. The crane device 6 includes a swivel base 7, a telescopic boom 8, a jib 9, a main hook block 10, a sub hook block 11, a hoisting cylinder 12, a main winch 13, a main wire rope 14, a sub winch 15, a sub wire rope 16, and a cabin 18. And a control device 39 (see FIG. 3).

  The swivel base 7 is configured to allow the crane device 6 to swivel. The swivel base 7 is provided on the frame of the vehicle 2 via an annular bearing. The annular bearing is arranged so that the center of rotation is perpendicular to the installation surface of the vehicle 2. The swivel base 7 is configured to be rotatable in one direction and the other direction with the center of the annular bearing as the center of rotation. The swivel base 7 is configured to be rotated by a hydraulic swivel motor 17 (see FIG. 2). The swivel base 7 is provided with a swivel position detection sensor 35 (see FIGS. 2 and 3) for detecting the swivel position.

  The telescopic boom 8 supports the wire rope so that the conveyed product W can be lifted. The telescopic boom 8 is composed of a plurality of boom members. Each boom member is inserted in a nested manner in the order of the cross-sectional area. The telescopic boom 8 is configured to be telescopic in the axial direction by moving each boom member with an unillustrated telescopic cylinder. The telescopic boom 8 is provided so that the base end of the base boom member can swing on the swivel base 7. Accordingly, the telescopic boom 8 is configured to be horizontally rotatable and swingable on the frame of the vehicle 2.

  The jib 9 expands the lift and work radius of the crane device 6. The jib 9 is held in a posture along the base boom member by a jib support portion provided on the base boom member of the telescopic boom 8. The base end of the jib 9 is configured to be connectable to the jib support portion of the top boom member. The jib 9 is configured to be connectable to the tip of the top boom member by driving a pin (not shown) into the jib support part.

  The main hook block 10 suspends the conveyed product W. The main hook block 10 is provided with a plurality of hook sheaves around which the main wire rope 14 is wound and a main hook that suspends the conveyed product W. The sub hook block 11 suspends the conveyed product W. The sub hook block 11 is provided with a sub hook for hanging the conveyed product W.

  The raising / lowering cylinder 12 raises and lowers the telescopic boom 8 and maintains the posture of the telescopic boom 8. The hoisting cylinder 12 is composed of a hydraulic cylinder composed of a cylinder part and a rod part. In the hoisting cylinder 12, the end of the cylinder portion is swingably connected to the swivel base 7, and the end of the rod portion is swingably connected to the base boom member of the telescopic boom 8. The hoisting cylinder 12 erects the telescopic boom 8 by supplying hydraulic oil so that the rod part is pushed out from the cylinder part, and the telescopic boom is supplied by operating oil so that the rod part is pushed back to the cylinder part. 8 is configured to fall down.

  The main winch 13 which is a hydraulic winch is for carrying in (winding up) and feeding out (winding down) the main wire rope 14. The main winch 13 is configured such that a main drum around which a main wire rope 14 is wound is rotated by a main hydraulic motor, and the main wire rope 14 is fed and unloaded.

  A sub-winch 15 that is a hydraulic winch is used for feeding and unloading the sub-wire rope 16. The sub winch 15 is configured such that a sub drum around which the sub wire rope 16 is wound is rotated by a sub hydraulic motor so that the sub wire rope 16 is fed and unloaded.

  The hydraulic turning motor 17 turns the turntable 7 (see FIG. 2). The turning motor 17 is composed of a plunger motor. The turning motor 17 has a right turning oil passage 27 connected to the right turning port communicating with the right turning plunger, and the left turning port connected to the left turning port communicating with the left turning plunger. An oil passage 28 is connected (see FIG. 2). The turning motor 17 turns the turntable 7 to the right by supplying hydraulic oil to the right-turning plunger through the right-turn oil passage 27, and operates to the left-turn plunger through the left-turn oil passage 28. When the oil is supplied, the swivel base 7 is configured to turn left.

  The cabin 18 covers the cockpit. The cabin 18 is provided on the side of the telescopic boom 8 in the swivel base 7. A cockpit (not shown) is provided inside the cabin 18. In the cockpit, a main operation valve (not shown) for operating the main winch 13, a sub operation tool (not shown) for operating the sub winch 15, a hoisting operation tool (not shown) for operating the telescopic boom 8, A handle (not shown) for moving the crane 1, a turning operation tool 19 (see FIG. 3) for turning the swivel base 7, an anti-sway control switch 20 (see FIG. 3) for performing anti-sway control, etc. Is provided.

  The crane 1 configured as described above can move the crane device 6 to an arbitrary position by running the vehicle 2. Moreover, the crane 1 raises the telescopic boom 8 to an arbitrary hoisting angle by the hoisting cylinder 12, extends the telescopic boom 8 to an arbitrary telescopic boom 8 length, or connects the jib 9 to the crane device 6. The head and working radius can be expanded.

  Below, the hydraulic circuit regarding the turning motor 17 of the turntable 7 which the crane 1 comprises is demonstrated using FIG. 2 and FIG.

  The hydraulic circuit includes a hydraulic pump 21 to which a driving force from the engine 4 is transmitted, a turning hydraulic circuit 23, and a control device 39 (see FIG. 3).

  As shown in FIG. 2, the hydraulic pump 21 discharges hydraulic oil. The hydraulic pump 21 is driven by the engine 4. The hydraulic oil discharged from the hydraulic pump 21 is supplied to the turning hydraulic circuit 23 via the discharge oil passage 22. A relief valve 22 a is provided in the discharge oil passage 22 of the hydraulic pump 21.

  The turning hydraulic circuit 23 operates the turning motor 17. The turning hydraulic circuit 23 includes a turning motor 17, a right turning operation switching valve 24, a left turning operation switching valve 25, a turning switching valve 26, a right free turning relief valve 29, a left free turning relief valve 30, A free turning operation opening / closing valve 31, a slow stop relief valve 32, a right turning pressure sensor 33, and a left turning pressure sensor 34 are provided.

  The right-turning operation switching valve 24, which is an electromagnetic proportional switching valve, switches the turning switching valve 26. The right turn operation switching valve 24 is configured to excite the electromagnet by a control signal from the control device 39. A hydraulic pump 21 is connected to the right turn operation switching valve 24. Further, one pilot port of the turning switching valve 26 is connected to the switching valve 24 for turning right. Pilot hydraulic oil (hereinafter simply referred to as “pilot hydraulic oil”) is supplied from the hydraulic pump 21 to the right turn operation switching valve 24. The right turning operation switching valve 24 is configured to supply pilot hydraulic oil from the hydraulic pump 21 to one pilot port of the turning switching valve 26.

  The left turn operation switching valve 25, which is an electromagnetic proportional switching valve, switches the turning switching valve. The left turn operation switching valve 25 is configured to excite an electromagnet by a control signal from the control device 39. A hydraulic pump 21 is connected to the left turn operation switching valve 25. The other pilot port of the turning switching valve 26 is connected to the left turning operation switching valve 25. Pilot hydraulic oil is supplied from the hydraulic pump 21 to the left turn operation switching valve 25. The left turning operation switching valve 25 is configured to supply pilot hydraulic oil from the hydraulic pump 21 to one pilot port of the turning switching valve 26.

  The turning switching valve 26 switches the direction of hydraulic oil supplied to the turning motor 17. A hydraulic pump 21 is connected to a supply port of the turning switching valve 26 via a discharge oil passage 22. One port of the turning switching valve 26 is connected to the right turning port of the turning motor 17 via the right turning oil passage 27 which is one supply / discharge oil passage. The other port of the turning switching valve 26 is connected to the left turning port of the turning motor 17 via the left turning oil passage 28 which is the other supply / discharge oil passage.

  When the pilot hydraulic oil is not supplied from the right turning operation switching valve 24 and the left turning operation switching valve 25, the turning switching valve 26 has a right turning oil passage 27 and a left turning oil passage 28. Switch to close. Thereby, the rotation position of the turning motor 17 is maintained. When the pilot hydraulic oil is supplied from the right turning operation switching valve 24, the turning switching valve 26 allows the hydraulic oil from the hydraulic pump 21 to rotate the turning motor 17 to the right via the right turning oil passage 27. To be supplied to the plunger. Thereby, the turning motor 17 rotates the turntable 7 in the right direction which is one direction. When the pilot hydraulic oil is supplied from the left turning operation switching valve 25, the turning switching valve 26 receives the hydraulic oil from the hydraulic pump 21 via the left turning oil passage 28, and the plunger for left rotation of the turning motor 17. Switch to be supplied to. Thereby, the turning motor 17 rotates the turntable 7 in the left direction.

  The right free turning relief valve 29, which is an open / close valve, opens when the oil pressure in the left turning oil passage 28 is equal to or greater than a predetermined value, and connects the left turning oil passage 28 and the right turning oil passage 27. Is. The right free turning relief valve 29 is composed of a pilot type relief valve that can be opened when the pilot hydraulic oil is discharged. The right free turning relief valve 29 is disposed downstream of the turning switching valve 26 and flows through the left turning oil passage 28 via a check valve whose flow direction changes from the left turning oil passage 28 to the right turning oil passage 27. And the right turning oil passage 27 are communicated with each other. That is, the right free turning relief valve 29 is configured such that hydraulic oil can flow from the left turning oil passage 28 toward the right turning oil passage 27 when the oil pressure in the left turning oil passage 28 is equal to or greater than a predetermined value. Has been.

  When the pilot hydraulic oil is discharged, the right free turning relief valve 29 is opened when an external force that rotates the turning motor 17 in the right direction is applied and the oil pressure in the left turning oil passage 28 becomes a predetermined value or more. Is done. Thereby, the turning motor 17 can discharge the hydraulic oil from the left-turning plunger to the left-turning oil passage 28 and the right-turning plunger can suck the hydraulic oil from the right turning oil passage 27. Rotated right by external force.

  The left free turning relief valve 30, which is an on-off valve, opens when the oil pressure in the right turning oil passage 27 is greater than or equal to a predetermined value, and communicates the right turning oil passage 27 and the left turning oil passage 28. To do. The left free turning relief valve 30 is composed of a pilot type relief valve that can be opened by discharging pilot hydraulic oil. The left free turning relief valve 30 is located downstream of the turning switching valve 26 and flows through the right turning oil passage through a check valve whose flow direction changes from the right turning oil passage 27 to the left turning oil passage 28. 27 and the left turning oil passage 28 are communicated with each other. That is, the left free turning relief valve 30 allows hydraulic oil to flow from the right turning oil passage 27 toward the left turning oil passage 28 when the hydraulic pressure of the right turning oil passage 27 is equal to or greater than a predetermined value. It is configured.

  When the pilot hydraulic oil is discharged, the left free turning relief valve 30 is opened when an external force that rotates the turning motor 17 in the left direction is applied and the hydraulic pressure in the right turning oil passage 27 exceeds a predetermined value. To be spoken. As a result, the turning motor 17 can discharge the hydraulic oil from the right turning plunger to the right turning oil passage 27 and the left turning plunger can suck the working oil from the left turning oil passage 28. Rotated leftward by external force.

  The free turning operation opening / closing valve 31 is used to control whether the right free turning relief valve 29 and the left free turning relief valve 30 can be opened. The open / close valve 31 for free turning operation is composed of an electromagnetic valve. A pilot port for a right free turning relief valve 29 and a left free turning relief valve 30 is connected to the free turning operation on-off valve 31. Further, the free turning operation open / close valve 31 is connected to the hydraulic oil tank 36. Thereby, the free turning operation on-off valve 31 is configured to return the pilot hydraulic oil of the right free turning relief valve 29 and the left free turning relief valve 30 to the hydraulic oil tank 36 by opening the valve. Yes. That is, the free turning operation on / off valve 31 determines whether the left free turning relief valve 30 is opened when the hydraulic pressure of the right turning oil passage 27 is equal to or higher than a predetermined value by the opening / closing operation. When the hydraulic pressure of 28 is equal to or higher than a predetermined value, whether or not the right free turning relief valve 29 is opened is switched.

  The relief valve 32 for slow stop reduces the flow rate of the hydraulic oil that passes through the open / close valve 31 for the free turning operation. The slow stop relief valve 32 is provided between the free turning operation on-off valve 31 and the hydraulic oil tank 36. The slow stop relief valve 32 is constituted by an electromagnetic proportional relief valve. As a result, the relief valve 32 for slow stop reduces the flow rate of the pilot hydraulic oil from the relief valve 29 for right free rotation and the relief valve 30 for left free rotation discharged to the hydraulic oil tank 36 through the open / close valve 31 for free rotation operation. It is configured to be arbitrarily reduced.

  A right turning pressure sensor 33 is connected to the right turning oil passage 27. The right turning pressure sensor 33 can detect the hydraulic pressure of the hydraulic oil in the right turning oil passage 27 (hereinafter, referred to as a unit “right turning hydraulic pressure Pr”) in real time. The right turning pressure sensor 33 is connected to the control device 39.

  A left turning pressure sensor 34 is connected to the left turning oil passage 28. The left turn pressure sensor 34 can detect the hydraulic pressure of the hydraulic oil in the left turn oil passage 28 (hereinafter, referred to as a unit “left turn hydraulic pressure Pl”) in real time. The left turn pressure sensor 34 is connected to the control device 39.

  As shown in FIG. 3, the control device 39 performs turning control and turning free control of the turntable 7. The control device 39 is provided in the vehicle 2. The control device 39 controls the operations of the right turn operation switching valve 24 and the left turn operation switching valve 25 based on the operation of the turning operation tool 19. Further, the control device 39 controls the operation of the open / close valve 31 for the free turning operation based on the operation of the anti-sway control switch 20. Further, the control device 39 controls the operation of the open / close valve 31 for the free turning operation based on the fluctuation of the right turning hydraulic pressure Pr and the fluctuation of the left turning hydraulic pressure Pl. The control device 39 may actually be configured such that a CPU, ROM, RAM, HDD, or the like is connected by a bus, or may be configured by a one-chip LSI or the like. The control device 39 stores various programs and data for controlling the operations of the switching valve 24 for the right turning operation, the switching valve 25 for the left turning operation, and the opening / closing valve 31 for the free turning operation.

  The control device 39 is connected to the turning operation tool 19 and can acquire a signal from the turning operation tool 19.

  The control device 39 is connected to the anti-sway control switch 20 and can acquire a signal from the anti-sway control switch 20.

  The control device 39 is connected to the right turn operation switching valve 24, and controls the opening and closing by selectively exciting the electromagnet of the right turn operation switching valve 24 based on the signal from the turning operation tool 19. be able to.

  The control device 39 is connected to the left turn operation switching valve 25, and controls the opening and closing by selectively exciting the electromagnet of the left turn operation switching valve 25 based on the signal from the turning operation tool 19. it can.

  The control device 39 is connected to the free turning operation opening / closing valve 31 and selects the electromagnet of the free turning operation opening / closing valve 31 based on the signal from the right turning pressure sensor 33 and the signal from the left turning pressure sensor 34. It is possible to control the opening and closing by exciting them automatically.

  The control device 39 is connected to the right turn pressure sensor 33 and can acquire a signal of the right turn hydraulic pressure Pr detected by the right turn pressure sensor 33.

  The control device 39 is connected to the left turning pressure sensor 34 and can acquire a signal of the left turning hydraulic pressure Pl detected by the left turning pressure sensor 34.

  The control device 39 is connected to the turning position detection sensor 35 and can acquire a signal of the position of the turntable 7 detected by the turning position detection sensor 35.

  The control device 39 is connected to the wire rope length detection sensor 37 and can acquire a signal of the wire rope length detected by the wire rope length detection sensor 37.

  The control device 39 is connected to the boom length detection sensor 38 and can acquire a boom length signal detected by the boom length detection sensor 38.

  The crane 1 including the turning hydraulic circuit 23 configured as described above operates the right turning operation switching valve 24 and the left turning operation switching valve 25 by an operation signal from the control device 39 to turn the turning switching valve. 26 is switched. That is, the crane 1 can freely turn the swivel base 7 by switching the flow of the hydraulic oil supplied to the turning motor 17 by an operation signal from the control device 39. Further, the crane 1 opens the free turning operation opening / closing valve 31 by an operation signal from the control device 39 to switch the right free turning relief valve 29 and the left free turning relief valve 30 to the openable state. . That is, the crane 1 causes the right turning oil passage 27 and the left turning oil passage 28 to communicate with each other by an operation signal from the control device 39, and is discharged from the turning motor 17 when an external force is applied to the turntable 7. By rotating the hydraulic oil, it is possible to perform a swing-free control in which the swivel base 7 is swung by an external force. At this time, when the crane 1 determines that the swivel base 7 is turning beyond the allowable range from the detection value of the turning position detection sensor 35, the crane 1 is configured to be slowly stopped by the relief valve 32 for slow stop. .

  Below, the swing prevention control of the conveyed product W using the turning free control of the crane 1 is demonstrated using FIG. It is assumed that the crane 1 has completed the right turn of the swivel base 7.

  As shown in FIG. 4 (a), the crane 1 completes the right turn by switching the turning switching valve 26 so as to close the right turning oil passage 27 and the left turning oil passage 28. The turning angular velocity ω of the turntable 7 becomes zero (see FIG. 4B). At this time, a pendulum motion (so-called roll) that swings in the circumferential direction of the turning diameter with the tip of the telescopic boom 8 as a fulcrum occurs due to the inertial force by turning right (black) on the transported object W suspended by the crane 1 (black). (See painted arrow). A reaction force of the pendulum movement of the conveyed product W is applied to the turning motor 17 that holds the position of the swivel base 7 of the crane 1.

  As shown in FIG. 4B, the crane 1 is used to rotate the right turning hydraulic pressure Pr in the right turning oil passage 27 connected to the right turning plunger of the turning motor 17 and the left turning of the turning motor 17. In order to receive the reaction force of the pendulum motion, the left-turn hydraulic pressure Pl in the left-turn oil passage 28 connected to the plunger fluctuates according to the period of the pendulum motion. When the control device 39 of the crane 1 acquires a signal from the anti-sway control switch 20 (see FIG. 3), the control device 39 starts the anti-sway control of the conveyed product W and detects the right turning hydraulic pressure detected by the right turning pressure sensor 33. Pr and the left turning hydraulic pressure Pl detected by the left turning pressure sensor 34 are acquired continuously and continuously at predetermined intervals.

  As shown in FIG. 5, when the control device 39 acquires the right turning hydraulic pressure Pr and the left turning hydraulic pressure Pl for a predetermined time, the control device 39 calculates the right turning hydraulic pressure Pr and the left turning hydraulic pressure Pl for the acquired predetermined time. One of the positive and negative oil pressures is reversed to generate one continuous hydraulic pressure waveform Wv. At the same time, the control device 39 calculates the pendulum motion frequency fc of the conveyed product W based on the wire rope length detected by the wire rope length detection sensor 37 and the boom length detected by the boom length detection sensor 38. Then, the control device 39 uses a band-pass filter whose resonance frequency is the pendulum motion frequency fc of the transported object W, and the pendulum of the transported object W that is a frequency of shaking inherent to the transported object W from the combined hydraulic waveform Wv. A resonance hydraulic waveform Wp having a frequency fc of motion is extracted.

  As shown in FIG. 6, the control device 39 extracts a resonance hydraulic pressure waveform Wp extracted by applying a bandpass filter to the right turning hydraulic pressure Pr and the left turning hydraulic pressure Pl that are continuously and continuously acquired at predetermined intervals. When the hydraulic pressure Pp reaches the valve opening reference pressure Ps or the valve opening reference pressure −Ps of the free swivel opening / closing valve 31, the right free swiveling relief valve 29, and the left free swiveling relief valve 30, the free swiveling opening / closing valve 31 Open the valve. Then, the control device 39 opens the free turning operation on-off valve 31 for an arbitrarily determined valve opening time To that is equal to or less than a half cycle of the swing cycle Cy of the conveyed product W. That is, the control device 39 is free to turn for the valve opening time To with reference to the valve opening reference pressure Ps or the valve opening reference pressure −Ps (the valve opening reference pressure −Ps is the valve opening reference pressure corresponding to the right turning hydraulic pressure Pr). By performing the control, the swivel base 7 is controlled so as not to receive a reaction force greater than a predetermined value of the pendulum motion of the conveyed product W. In this way, the crane 1 applies the bandpass filter to the right turning hydraulic pressure Pr and the left turning hydraulic pressure Pl to extract the resonance hydraulic pressure waveform Wp, thereby turning the low-frequency component that bears the holding force of the swivel base 7 and the turning. Only the hydraulic pressure related to the pendulum motion of the conveyed product W can be released by opening the opening / closing valve 31 for the free turning operation while leaving a high-frequency component that bears a large braking force (surge pressure) at the time of stopping.

Specifically, when the crane 1 stops after a right turn and the conveyed product W is swaying in the right turn direction, the left turn hydraulic pressure Pl of the crane 1 increases due to the reaction force of the pendulum movement of the conveyed product W. . When the oil pressure Pp of the extracted resonance oil pressure waveform Wp reaches the valve opening reference pressure Ps, the control device 39 opens the open / close valve 31 for the free turning operation. Thereby, in the crane 1, the relief valve 29 for right free turning is opened. That is, in the crane 1, the swivel base 7 is switched to a state in which the swivel base 7 can turn right, and the swivel base 7 does not receive the reaction force of the conveyed product W in the right turn direction.
Accordingly, as shown in FIG. 7 (a), the crane 1 follows the transported object W by the inertial force of the transported object W (see the black arrow) and the swivel base 7 is turned to the right (light arrow). reference). In the pendulum movement of the transported object W, the swing point of the transported object W becomes smaller because the fulcrum, which is the tip of the telescopic boom 8, moves in the swinging direction of the transported object W due to the turning of the swivel base 7.

  As shown in FIG. 6, the control device 39 opens the free turning operation on / off valve 31 and then closes the free turning operation on / off valve 31 after the valve opening time To has elapsed. As a result, in the crane 1, the right free turning relief valve 29 is closed. That is, in the crane 1, the position of the swivel base 7 is maintained, and the swivel base 7 receives the reaction force of the pendulum movement of the conveyed product W. Accordingly, the crane 1 is prevented from turning the swivel base 7 by the external force such as wind being applied in the direction of shaking of the transported object W, and the transported object W does not flow.

When the conveyed product W starts to swing leftward due to the swing back of the pendulum motion, the right hydraulic pressure Pr of the crane 1 increases due to the reaction force of the pendulum motion of the conveyed product W. When the oil pressure Pp of the extracted resonance oil pressure waveform Wp reaches the valve opening reference pressure -Ps, the control device 39 opens the free turning operation on-off valve 31. As a result, in the crane 1, the left free turning relief valve 30 is opened. That is, in the crane 1, the swivel base 7 is switched to a state in which the swivel base 7 can freely turn, and the swivel base 7 does not receive the reaction force of the transported object W in the left turn direction.
Accordingly, as shown in FIG. 7 (b), the crane 1 follows the transported object W by the inertial force of the swing of the transported object W (see the black arrow), and the swivel base 7 is turned to the left (light ink painted arrow). reference). In the pendulum movement of the transported object W, the swing point of the transported object W becomes smaller because the fulcrum, which is the tip of the telescopic boom 8, moves in the swinging direction of the transported object W due to the turning of the swivel base 7.

  As shown in FIG. 6, the control device 39 opens the free turning operation opening / closing valve 31 again, and then closes the free turning operation opening / closing valve 31 after the valve opening time To elapses. Thereby, as for the crane 1, the relief valve 30 for left free rotation is closed. That is, the crane 1 holds the position of the swivel base 7, and the swivel base 7 receives the reaction force of the pendulum movement of the conveyed product W. Accordingly, the crane 1 is prevented from turning the swivel base 7 by the external force such as wind being applied in the direction of shaking of the transported object W, and the transported object W does not flow.

  Next, the control mode of the anti-sway control of the conveyed product W in the control device 39 of the crane 1 will be specifically described with reference to FIG. In this embodiment, the control device 39 acquires a signal from the anti-sway control switch 20 and acquires the right turning hydraulic pressure Pr and the left turning hydraulic pressure Pl continuously and continuously at predetermined intervals. And

  In step S110, the control device 39 synthesizes the hydraulic pressure waveform Wv from the right turning hydraulic pressure Pr and the left turning hydraulic pressure Pl that are continuously acquired, and shifts the step to step S120.

  In step S120, the control device 39 uses a bandpass filter whose resonance frequency is the pendulum motion frequency fc of the conveyed product W, and the resonance hydraulic waveform Wp of the frequency fc of the pendulum motion of the conveyed product W from the synthesized hydraulic waveform Wv. Is extracted, and the process proceeds to step S130.

In step S130, the control device 39 determines whether or not the hydraulic pressure Pp of the resonance hydraulic pressure waveform Wp is equal to or higher than the valve opening reference pressure Ps or equal to or lower than the valve opening reference pressure −Ps. That is, the control device 39 determines whether or not the hydraulic pressure Pp of the resonant hydraulic pressure waveform Wp is equal to or higher than the valve opening reference pressure | Ps |.
As a result, when it is determined that the hydraulic pressure Pp of the resonance hydraulic waveform Wp is equal to or higher than the valve opening reference pressure | Ps |, the control device 39 shifts the step to step S140.
On the other hand, when it is determined that the hydraulic pressure Pp of the resonant hydraulic pressure waveform Wp is not equal to or higher than the valve opening reference pressure | Ps |, the control device 39 shifts the step to step S160.

  In step S140, the control device 39 opens the free turning operation on-off valve 31 and shifts the step to step S150.

  In step S150, the control device 39 closes the free turning operation on / off valve 31 after a predetermined valve opening time To that is equal to or less than a half cycle of the swing cycle Cy has elapsed since the opening of the free turning operation on / off valve 31. Then, the step moves to step S160.

In step S160, the control device 39 determines whether or not the state in which the hydraulic pressure Pp of the resonant hydraulic pressure waveform Wp is less than the valve opening reference pressure Ps continues for a predetermined time or more.
As a result, when it is determined that the state where the hydraulic pressure Pp of the resonance hydraulic pressure waveform Wp is lower than the valve opening reference pressure Ps for a predetermined time or longer, the control device 39 ends the anti-sway control.
On the other hand, when it is determined that the state where the hydraulic pressure Pp of the resonance hydraulic pressure waveform Wp is less than the valve opening reference pressure Ps has not been continued for a predetermined time or longer, the control device 39 shifts the step to step S130.

  By configuring in this way, the crane 1 switches the holding state of the position of the swivel base 7 based on the calculated resonance hydraulic waveform Wp of the conveyed product W. That is, the crane 1 is configured to suppress the swing of the conveyed product W by passive control using swing-free control in which hydraulic oil is not supplied from the hydraulic pump 21 to the swing motor 17. Therefore, since the crane 1 does not supply energy from the hydraulic pump 21 in the swing prevention control of the transported object W, the swing of the transported object W is not amplified even if the control timing is shifted. Thereby, even if disturbances, such as a wind, affect the state of shaking of the conveyed product W, the fluctuation | variation of a period intrinsic | native to the conveyed product W can be suppressed.

  As shown in FIG. 9, as a modification of the present embodiment, the crane 1 is configured so that the transported object W swings in the direction in which the swivel 7 is swung to the previous position and the swivel 7 is swung to the last. The execution time of the turn free control, that is, the opening / closing valve 31 for the free turn operation may be set to a different valve opening time To1 and valve opening time To2 depending on the case where the conveyed product W is shaking in the opposite direction to the direction in which it was moving. . By comprising in this way, turning free control can be appropriately implemented according to the operation state of the crane 1, an attitude | position, the weight of the conveyed product W, etc. FIG.

  Next, the crane 40 (refer FIG.1, FIG.3, FIG.4) which is 2nd embodiment of a crane is demonstrated using FIG. In addition, the crane 40 which concerns on the following 2nd embodiment uses the name, figure number, and symbol which were used in the description as what is applied instead of the crane 1 in the crane 1 shown in FIGS. In the following embodiment, the same points as those of the embodiment described above will be omitted from the specific description, and different parts will be mainly described.

  A description will be given of the anti-swaying control of the conveyed product W using the swing-free control of the crane 40 in the second embodiment. The crane 40 is characterized in that the swivel-free control is performed only when the transported object W is swaying in the direction opposite to the direction in which the swivel base 7 is swung until just before. In addition, the crane 40 in this embodiment assumes that the right turn of the swivel base 7 has been completed.

  As shown in FIG. 10, the control device 39 uses a band-pass filter that uses the frequency fc of the pendulum motion of the conveyed product W as a resonance frequency in the hydraulic waveform Wv generated from the right turning hydraulic pressure Pr and the left turning hydraulic pressure Pl. The resonance hydraulic waveform Wp having the frequency fc of the pendulum motion of the conveyed product W is extracted. The control device 39 opens the free swing operation on-off valve 31, the right free swing relief valve 29, and the left free swing relief valve 30 with the hydraulic pressure Pp having a resonance hydraulic pressure waveform Wp corresponding to the swing hydraulic pressure in the direction opposite to the swing direction. When the reference pressure Ps or the valve opening reference pressure −Ps is reached, the free turning operation on-off valve 31 is opened. Then, the control device 39 opens the free turning operation opening / closing valve 31 for a valve opening time To that is equal to or less than a half cycle of the swing cycle Cy of the conveyed product W.

  The control device 39 performs the swing-free control for the valve opening time To with reference to the valve opening reference pressure Ps or the valve opening reference pressure −Ps only when the conveyed product W is swung in the direction opposite to the swing direction. Control is performed so that the table 7 does not receive a reaction force greater than a predetermined value of the pendulum motion of the conveyed product W that is swung in the direction opposite to the turning direction. That is, the crane 40 considers the possibility that there is an obstacle ahead of the swivel base 7 in the swiveling direction, and when the transported object W shakes in the swivel direction of the swivel base 7, In order to prevent contact with an obstacle, the turn-free control is not performed.

  Specifically, when the crane 40 stops after turning right and the conveyed product W is swinging in the right turning direction, the left turning hydraulic pressure Pl of the crane 40 is increased by the reaction force of the pendulum movement of the conveyed product W. . Even when the hydraulic pressure Pp of the extracted resonance hydraulic pressure waveform Wp reaches the valve opening reference pressure Ps, the control device 39 does not open the open / close valve 31 for the free turning operation. Thereby, the relief valve 29 for the right free turning is not opened in the crane 40. That is, in the crane 40, the swivel stop 7 is maintained in a stopped state, and the swivel base 7 receives the reaction force of the conveyed product W in the right turn direction.

  When the transported object W starts to swing in the left-turning direction that is opposite to the turning direction of the swivel base 7 due to the swing-back of the pendulum motion, the crane 40 generates the right-turn hydraulic pressure Pr by the reaction force of the pendulum motion of the transported object W. To rise. When the oil pressure Pp of the extracted resonance oil pressure waveform Wp reaches the valve opening reference pressure -Ps, the control device 39 opens the free turning operation on-off valve 31. As a result, the relief valve 30 for the left free rotation of the crane 40 is opened. That is, the crane 40 is switched to a state in which the swivel base 7 can freely turn, and the swivel base 7 does not receive the reaction force of the conveyed product W in the left turn direction. Therefore, the crane 40 follows the transported object W by the inertial force of the transported object W (see the black arrow), and the swivel base 7 is turned counterclockwise in the direction opposite to the turning direction (see FIG. 7B). (See light ink arrow). In the pendulum movement of the transported object W, the swing point of the transported object W becomes smaller because the fulcrum, which is the tip of the telescopic boom 8, moves in the swinging direction of the transported object W due to the turning of the swivel 7.

  By configuring in this way, the crane 40 holds the position of the swivel base 7 and the swivel base 7 receives the reaction force of the pendulum movement of the transported object W when the transported object W shakes in the swiveling direction. Further, when the transported object W swings in the direction opposite to the turning direction, the crane 40 opens the opening / closing valve 31 for the free turning operation so that the swivel base 7 can be turned freely. It is configured not to receive force. Therefore, the crane 40 prevents the swivel base 7 from moving in the swivel direction after the swivel base 7 stops turning. Can do.

  As described above, the cranes 1 and 40 are configured to open and close the opening / closing valve 31 for free turning operation, which is an electromagnetic valve, as a swing prevention control of the conveyed product W. However, the present invention is not limited to this and is an electromagnetic proportional relief valve. It is good also as a structure which opens and closes the relief valve 32 for slow stops. In this case, the cranes 1 and 40 may control the opening degree of the relief valve 32 for slow stop according to the fluctuation of the right turning hydraulic pressure Pr and the right turning hydraulic pressure Pr. By comprising in this way, the turning free state and position holding state of the turntable 7 are switched gently. Moreover, the cranes 1 and 40 may be a case where the conveyed product W is suspended from the jib 9 attached to the telescopic boom 8. In the present embodiment, the cranes 1 and 40 change the valve opening time To, the valve opening reference pressure Ps or the valve opening reference pressure −Ps according to the type of the crane 1, the posture, the weight of the conveyed object W, and the conveying speed. You may comprise.

  The above-described embodiments are merely representative, and various modifications can be made without departing from the scope of one embodiment. It goes without saying that the present invention can be embodied in various forms, and the scope of the present invention is indicated by the description of the scope of claims, and the equivalent meanings of the scope of claims, and all the scopes within the scope of the claims. Includes changes.

DESCRIPTION OF SYMBOLS 1 Crane 7 Rotating base 8 Telescopic boom 9 Jib 17 Rotating motor 21 Hydraulic pump 27 Right turning oil passage 28 Left turning oil passage 29 Right free turning relief valve 30 Left free turning relief valve 31 Open / close valve for free turning operation

Claims (4)

When rotating the hydraulic swing motor of the swivel base provided with the telescopic boom in one direction, one supply / discharge oil passage to which hydraulic oil is supplied from the hydraulic pump, and when rotating the swing motor in the other direction A crane in which the other supply / discharge oil passage to which hydraulic oil from the hydraulic pump is supplied is communicated via an on-off valve;
When communication between the one supply / discharge oil passage and the other supply / discharge oil passage and the hydraulic pump is interrupted, fluctuations in the hydraulic pressure of the one supply / discharge oil passage and the hydraulic pressure of the other supply / discharge oil passage A crane that opens and closes the on-off valve according to the condition.   Resonance hydraulic pressure waveform, which is a frequency of shaking inherent to the transported object, from the hydraulic waveform of the one supply / discharge oil path and the other supply / exhaust oil path caused by the swing of the transported object suspended from the telescopic boom. The crane according to claim 1, wherein the on-off valve is opened and closed based on the resonance hydraulic waveform.   The crane according to claim 2, wherein when the oil pressure of the resonance oil pressure waveform is higher than a reference value, the on-off valve is opened for a predetermined time determined within a range within a half cycle of the resonance oil pressure waveform.   The crane according to claim 2 or 3, wherein when the oil pressure of the resonance oil pressure waveform is higher than a reference value, the on-off valve is opened for a valve opening time set according to the direction of shaking of the conveyed product. .

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