JPH1017268A - Skew swing preventive method and device of crane suspending cargo - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize a skew by controlling hoisting tensile force of a diagonal line position of a suspending tool so as to become an antiphase to measuring skew rotation while measuring a skew angle and angular velocity of a suspending cargo after enabling skew operation of the suspending tool by moderately adjusting hoisting rope tensile force of a diagonal line position of a suspending tool support point. SOLUTION: A rope 14R is operated in the B direction and a rope 14L is operated in the F direction by right side and left side swing preventive devices 30R and 30L, and the right side strengthens tensile force of a front suspending tool sheave 24RF, and the left side strengthens tensile force of a rear suspending tool sheave 14LB, and they are respectively put in a one-sidedly suspending condition, and a suspending tool is put in a condition of being suspended by a pair of sheaves 24RF and 24LB running along a diagonal line of its one. An interval between front and rear paired sheaves of raising-lowering guide sheaves 22 of upper four places of the suspending tool 16 is made larger than an interval between sheaves on the suspending tool 16 side, and horizontal component force proceeding forward and backward is generated in the right front suspending tool sheave 24RF and the left rear suspending tool sheave 24LB on a diagonal line, and a couple of forces around the Z axis is generated in the suspending tool 16, and a skew swing can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for steadying a suspended load on a crane, and more particularly to a crane for suspending four suspended loads such as a gantry crane for transporting containers in a container yard. Device for

[0002]

2. Description of the Related Art In general, when a suspended load is hung on a hanging rope of a traversing trolley like a container crane and the trolley is traversed to transport the suspended load, it is necessary to carry the suspended load so that the suspended load does not swing. Required for efficiency. In container cranes, when suspending the hanging equipment mounted on the top of the container from the trolley, four places of the hanging equipment are suspended from the trolley with hanging ropes. Skew (torsional vibration) of the suspended load may occur during traversing due to the displacement of the center of gravity of the container, and it takes time to correctly unload the cargo at the point of arrival. There is a disadvantage that efficiency is deteriorated.

[0003]

Conventionally, even if the center of gravity of a suspended load container is displaced or the like, even if torsional vibration occurs due to traversing operation, the operation is performed without control. There is a drawback that it is necessary to wait until the vibration converges at the position, and the handling operation of the container or the like cannot be performed quickly.

According to the present invention, as described above, in a crane having four suspended loads, when a skew occurs due to a shift in the center of gravity of the suspended load or the like, the skew is detected to minimize the skew. It is an object of the present invention to provide a method and an apparatus for preventing steadying of a suspended load of a crane, which can improve the cargo handling efficiency by controlling the load to be controlled.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for preventing a steady load on a suspended load of a crane according to the present invention. A lifting guide sheave provided on the trolley side corresponding to the lifting gear support point is arranged in line symmetry, and a space between a pair of adjacent lifting guide sheaves is enlarged from the lifting gear support point distance to increase the height on the trolley. It is arranged in a fixed position, the skew operation of the hoist is enabled by adjusting the tension of the hoisting rope at the diagonal position of the hoist support point, and the skew angle and the angular velocity of the suspended load are measured. It is characterized in that the hoist is controlled by controlling the hoisting tension at the diagonal position of the hanging tool so as to have a phase opposite to the skew rotation.

A skew steadying device for a suspended load of a crane according to the present invention is a trolley corresponding to a suspended portion supporting point in a suspended portion of a suspended load using a crane having a four-point suspension such as a container crane. As in the past, the lifting guide sheave provided on the side is arranged symmetrically at a fixed position on the trolley, and the interval between a pair of adjacent lifting guide sheaves is made larger than the interval between the support points of the lifting device, and the diagonal line of the lifting device A gripping operation mechanism for a hoisting rope wound around a support point disposed at a position, a means for detecting a skew angle and an angular velocity of the load, a detection signal from the detection means being input, and a moment of inertia of the load being provided. Calculates the natural cycle of the suspended load skew and outputs a skew attenuation signal to a gripping operation mechanism of a hoisting rope that is wound around a support point disposed at a diagonal position of the lifting device. Is obtained by a configuration in which a control unit that. In this case, the skew angle may be measured, and the computer may perform feedback control so that the skew angle is minimized.

[0007]

According to the above construction, the load can be swung by operating the hoisting rope so as to simultaneously raise the diagonal support points (hanging sheaves) of the hanging gear. In this case, four lifting guide sheaves provided on the trolley side are provided in the same manner as the lifting gear sheave. At this time, the lifting guide sheave is arranged in line symmetry, and the interval between a pair of adjacent guide sheaves is wider than that of the lifting gear. doing. Therefore, when the lifting rope sheave on the diagonal line is operated on the ascending side and the other pair is operated on the descending side to adjust the tension of the hoisting rope, the suspended state is established only by the lifting apparatus sheave on the ascending side. In connection with the elevating guide sheave, the hanging sheave is turned by generating a couple. Therefore, the skew can be minimized by measuring the skew angle and angular velocity of the container, adjusting the tension of the hoisting rope, and forcibly driving the suspended load to have the opposite phase to the torsional motion. is there.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A concrete embodiment of a method and an apparatus for preventing skew of a crane load according to the present invention will be described below with reference to the drawings.

[0009] A suspended load, for example, a container suspended by a trolley of a crane is suspended via a suspending device mounted on the upper surface thereof. Hoisting ropes from the trolley side are provided at four places on the upper surface of the suspending device. Are linked. Therefore, the suspended load constitutes a pendulum hanging below the trolley via a rope, and has a vibration system that rotates (skews) around a vertical axis, that is, a torsional vibration system. In view of this, a computer that performs crane control calculations is provided with equations of motion for the swing and torsional vibration of the suspended load. The equation of torsional motion of the suspended load can be expressed as the following equation.

## EQU1 ## θ ″ + ω ₀ ² θ = u

Therefore, the torsional vibration of the container may be measured, and the feedback control may be performed so that the torsional vibration becomes zero at the target position.

Here, the following two conceivable arrangements of the skew steadying drive device are conceivable. (1) The fixed end of the hoisting rope is gripped so as to be finely movable, and a driving device is attached. The drive unit performs skew steadying control and front-back tilting operation. A rope is attached so that the gravity of the suspended load does not impose a load on the driving device so that the gripping point can be finely moved at a high speed with small horsepower. Skew rest control, manual forward / backward tilting, and manual left / right tilting can be performed. The skew and forward / backward tilting can be performed using the same driving device. Uses another slow drive. (2) A sheave and a drive device for skew control are provided at the intermediate turn portion of the hoisting rope. In this case, the drive unit is not shared with the one used for tilting the sling, but is provided as an independent drive unit. This driving method can be realized by disposing the sheave at the intermediate turning point fixedly and disposing another tension control sheave for skew control. The tension of the four hoisting ropes may be controlled by finely moving the driving device, and the computer may be controlled to minimize the skew.

A control method using such means may be performed as follows. First, a load value of a suspended load is read into a computer (data from a load detector or a host computer), and a rope length is measured by an encoder attached to a drum, and read into a computer.

The computer estimates the moment of inertia of the suspended load. From the elastic constant of the rope and the rope length, the characteristics of the torsional vibration system composed of the rope and the sheave are calculated. Calculate the skew natural period of the torsional vibration system.

The skew angle and angular velocity of the container are measured by a detector (one of the following methods). (1) Two targets are placed on the upper surface of the suspended load, and the CC on the trolley is
An image is taken with a D camera, and the skew angle and angular velocity are measured simultaneously with the twist angle of the container by image processing. (2) An attitude angle detector (composed of a gyro, an accelerometer, etc.) is arranged on a suspended load, and its output is used. (3) A load meter is provided at each fine movement end of the hoisting rope, and a skew angle is estimated by a computer from the load of each rope.

By performing feedback control at the traversing target position so as to realize the skew steadying, it is possible to quickly perform drive control at the traversing target position so that the residual skew vibration is minimized.

[0016]

FIG. 1 shows an embodiment of a container crane equipped with a skew steadying device. The crane body 10 is equipped with a hoisting drum 12 and four hoisting ropes 14 (14RF, 14RB, 14LF, 14LF).
LB), and a container 18 as a suspended load is moved up and down by the hanging tool 16 by the rope 14.

If the coordinate system of the container 18 is
Axis, trolley moving direction is X axis, direction perpendicular to this is Y axis
Set to be an axis. The hoist drum 12 is set in parallel with the Y axis, and two pairs (four) of hoist ropes 1 on the left and right sides.
4 is unreeled from the drum 12. Each of the hoisting ropes 14R and 14L is wound symmetrically, and the front end sheave 20S fixedly arranged at the front end of the crane main body arranged in tandem along the moving direction of the trolley 11.
F, a back end sheave 20SB consisting of two sheaves arranged at the rear end. A pair of front and rear guide sheaves 22GF, 2GF, 2
2 GB are arranged. The elevating guide sheave 22 also includes a double sheave. These are symmetrically arranged, and left and right are distinguished by the attached symbols (-R or -L). Then, the lifting gear sheave 24 (24RF, 24RB,
24LF, 24LB), and the hoisting rope 14 is wrapped around it and suspended.

Referring now to the right hoisting rope 14R, one end is fixed to the hoisting drum 12 and the rope 14RB is fed out, and the back end sheave 20SB-
After being wrapped around the rear sheave 24RB-R from the rear elevating guide sheave 22GB-R via the R, and wrapping around the rear elevating guide sheave 22GB-R again, via the gripper 26R of the skew steadying device 30R. Connected to hoisting rope 14RF, front end sheave 20SF-
Wrap around R. The rope 14RF passing through the front end sheave 20SF-R is connected to the front sheave 24R of the hanging device 16 from the front elevating guide sheave 22GF-R.
Wrap around the F, again the front elevating guide sheave 22GF-R
Through the back end sheave 20SB-R to the hoisting drum 12, where it is connected. The same applies to the left hoisting rope 14L, the back end sheave 20SB-L → the rear elevating guide sheave 22G.
BL → rear suspension sheave 24LB → rear lifting guide sheave 22GB-L → gripper 26L → front end sheave 20SF-L → front lifting guide sheave 22GF-L → front lifting sheave 24LF → front lifting guide sheave. 22GF
−L → back end sheave 20SB-L → winding drum 12

Since the sheaves 20 and 22 on the crane body 10 are arranged at fixed positions in such a rope-hung configuration, by rotating the hoist drum 12, the lifting guide sheave 22 and The rope length between the sheaves 24 becomes variable, and the container 18 is raised and lowered.

In this embodiment, in order to prevent the container 18 of the suspended load from swaying, the ropes 14 are particularly provided near the front end sheaves 20SF-R and 20SF-L.
The grippers 26 (26R, 26L) are attached to the R and 14L, and a skew steadying device 30 (30R, 30L) including an actuator 28 (28R, 28L) for driving the grippers 26 in the rope length direction is provided. .
In this example, a nut sleeve is provided on the gripping tool 26, and the actuator 28 is composed of a screw rod screwed into the nut sleeve and a rotation drive unit thereof. Are transported in the front and rear opposite directions across the front end sheave 20SF. As a result, if the length of the unreeling rope from the hoisting drum 12 is constant, the operation of the left and right steady rest devices 30 causes the front and rear hanger sheaves 24RF, 2F wound around the ropes 14R (14L) to be free ends.
The tension to 4RB (24LF, 24LB) changes, and only one of the front and rear tensions increases.

That is, in the arrangement shown in FIG. 1, if the rope 14R is operated in the direction B by the right-side steady rest device 30R, the right rear hanging sheave 24R supported by the rope 14R is supported.
The tension of B is weak, and the tension on the front hanging sheave 24RF increases, resulting in a single suspended state. On the other hand, the left-side steady rest 30
Assuming that the rope 14L is operated in the F direction by L, the tension of the left rear hanging sheave 24LB is strong, the tension on the front hanging sheave 24LF is reduced, and a single hanging state is achieved.
When both are operated at the same time, the hanger 16 is suspended by a pair of sheaves 24RF and 24LB along one diagonal, and the tension on the pair of sheaves 24RB and 24LF along the other diagonal decreases. I do.

Under such an operation, if the sheave interval between the front and rear pairs of the four elevating guide sheaves 22 located above the hanger 16 is set larger than the sheave interval on the hanger 16 side, the diagonal line A horizontal component toward the front of the trolley 10 is generated in the right front hanging sheave 24RF suspended above, and a horizontal component toward the rear of the trolley 10 is generated in the left rear hanging sheave 24LB. A couple around the Z-axis can be generated in the hanging tool 16. Therefore, in FIG. 1, the left and right steady rest devices 30R, 30L
Are operated in opposite directions, the container 18 can be rotated around the Z axis, and the skew can be prevented.

The anti-sway device 30 can also simultaneously (in FIG. 1) operate in the same direction to lift the front edge or the rear edge of the container hanging tool 16, thereby moving the container 18 around the Y axis. By rotating, a so-called front-back tilting (list) operation can be performed. Therefore, the skew steadying device 30 also serves as a front-rear tilting device.

The suspended load is composed of four hoisting ropes (14R
B, 14RF, 14LB, 14LF), one end of each rope is fixed to the hoist drum 12, and the other end is grippers 26R, 26L of the skew steadying device 30.
It is fixed to. In the equilibrium state of the suspended load, the gripper 26
Since the tension applied to R is equal to the tension of the hoisting ropes 14RB and 14RF in the opposite directions, the gravity component of the suspended load is suspended and becomes zero. The force required to drive the gripper 26R is 1
Because it is a small force of only 4RB and 14RF tension difference,
Even if a high-speed operation is required for the skew steadying control, it can be controlled by a small horsepower driving device.

On the other hand, since the sum of the tensions of the hoisting ropes 14RB and 14RF is applied to the back-end sheave 20SB of the left-right tilting device 36R, a large force is required to drive them. Use a high torque drive.

Further, in this embodiment, the crane body 10
Of the back-end sheave 20SB can be moved back and forth. This is such that the support brackets 32R, 32L of the back-end sheave 20SB can be pulled in or pushed in by the actuators 34R, 34L. Also, the screw rod is screwed into a sleeve nut provided on the bracket 32, and the rotation drive of the screw rod is performed. I try to make it. Left and right actuators 34R,
Push in one side of 34L (Trolley forward sheave 20SB
Of the corresponding rope 14R, 1
Right or left hanger sheave 2 wrapped around 4L
By lowering the 4RF, 24RB (or 24LF, 24LB), the container 18 can be rotated around the X-axis, thereby performing a so-called right-left tilt (trim) operation. Therefore, the position adjusting means of the back-end sheave 20SB is provided by
6R and 36L.

The container 18 suspended by the above-described structure is capable of manually rotating the front and rear and right and left while tilting the container 18 so as to reduce the rotational vibration about the Z axis.
Although it can be suppressed by 0, in order to perform this effectively, there is provided a means for detecting the shake of the container 18 and a control means for outputting a steadying drive control signal from the shake detection signal.

First, in the embodiment, an image processing apparatus is used as a shake detecting means. As shown in FIG. 2A, two targets 38 are attached to the upper surface of the hanging device 16. They are arranged so as to be at the same distance position on the Y axis from the origin of the coordinates set at the center of the upper surface. On the other hand, a CCD camera 40 is installed on the trolley 11 side so that the target 38 can be imaged. The CCD camera 40 is configured such that the origin of the image plane coordinates coincides with the suspension center, and therefore, the coordinate origin of the hanging tool 16 that is placed still and the image origin coincide. In the imaging screen by the image processing apparatus, FIG.
As shown in (2), by performing image processing, the displacement of each target 38 from the origin of the image plane coordinates can be detected, and the measurement position coordinates of each target 38 are (x1, y1), (x
2, y2). Thereby, the container 18
The skew angle and the angular velocity can be measured simultaneously with the deflection angle. That is,

[Equation 2] Front-back swing angle ψx = k1 * (x1 + x2) / 2

[Equation 3] Right and left swing angle ψy = k2 * (y1 + y2) / 2

## EQU00004 ## Each angle can be detected as skew angle .theta. = (X1-x2) / (y1-y2).

Then, the detection signal θ and the calculated angular velocity signal are output to the control means, where a vibration control signal is generated, and a vibration control drive signal is output to the drive system of the steady rest device 30.

FIG. 3 shows a skew damping control block.
The control flowchart is shown in FIG. As shown in FIG. 3, a position control signal is output by the motor drive control unit 42, and the drive amount φm of the steady rest device 30 is detected. Measuring. The signal detected by the measurement unit 44 is input to a vibration suppression drive signal generation unit 46, where a vibration suppression angle signal φmref is calculated and fed back, and is supplied to a subtractor 48 provided on the input side of the drive control unit 42. Is subtracted from the drive signal φm, and the steady rest drive signal to the steady rest device 30 is output as the error drive signal Δφm.

As shown in FIG. 4, the flow of the skew control first obtains the hanging load form and the weight data (step 100). Then, parameters such as moment of inertia are calculated (step 110), and the suspension length is obtained from an encoder or the like provided on the sheave (step 120). The control parameters such as the natural period of the pendulum system including the container 18 are estimated and calculated (step 130). At the time of suspending the container 18 at a predetermined position, the measuring unit 44 measures the control state such as the skew angle and the angular velocity from the imaging signal of the CCD camera 40 (step 140). The control amount is calculated (step 150). This is fed back to the drive control unit 42, where the error drive signal Δφm is calculated and output to the steadying device 30 (step 160), and the actuator 28 is operated so that the skew becomes zero.
The skew can be prevented early.
This control is repeatedly performed while the skew angle is detected (step 170).

The tilting in the front-back direction and the tilting in the left-right direction can be operated by the driver's manual operation as usual, independently of the skew steadying operation. In addition, the shake Δx in the front-rear direction is controlled by controlling the movement of the traverse trolley as in the related art.

Next, FIG. 5 shows a second embodiment. This is different from the first embodiment only in that the skew steadying device 30 and the left-right tilting device 36 are centrally installed at the same location. That is, the skew steadying device 30
Is mounted on a carriage 50 installed on the crane body 10, and the front-rear tilting device 30 is mounted on the carriage 50.
In the front-rear direction. The vibration suppression control is the same as in the first embodiment.

Next, FIG. 6 shows a third embodiment. This is an example in which the skew steadying device 30 is installed at the rear end of the crane main body 10 and the front-rear and left-right tilting device 58 is installed at the front end of the crane main body 10. By driving the actuator 34L of the skew steadying device 30, the skew tension control sheave 5 is driven.
By driving 2SLB to the tension side, 52SLF to the loose side, and driving 52SRF to the tension side and 52SRB to the loose side, a right-turning couple is generated in the suspended load, and the first
As in the second embodiment, the skew of the suspended load can be prevented. Further, the tilting of the suspended load by the manual operation of the driver can be performed by the front-rear left-right tilting device 58 completely independently of the skew steadying.

In the third embodiment, the tension control sheave 5
Although the gravity of the suspended load is applied to 2, a tension balance mechanism 54 is provided to balance the gravity and make the driving force of the actuator 34 only the unbalance amount of the rope tension.

FIG. 7 shows details of the tension balance mechanism 54. The tension balance mechanism 54L has tension control sheaves 52SLB and 52SLF on both sides, is rotatably supported by a central bearing between the sheaves, and has one end supported by the actuator 34L.

The resultant of the tension of the hoisting ropes 14LB, 14LF acts on the tension control sheaves 52SLB, 52SLF, respectively, but does not act on the actuator 34L because they are suspended by the tension balance mechanism 54L. Therefore, the power required for the actuator 34L when performing the skew steadying is only the unbalance amount of the rope tension as in the first and second embodiments because the gravity of the suspended load is canceled, and the actuator 34L can be driven with small horsepower. .

[0038]

As described above, according to the present invention, in a steady rest device of a suspended load using a crane such as a container crane having a four-point lifting device, the device is provided on the trolley side corresponding to the lifting device support point. A hoisting rope wound around a support point disposed at a diagonal position of the hoisting device, with the elevating guide sheave arranged in line symmetry and the interval between a pair of adjacent hoisting / lowering guide sheaves being wider than the interval between the hanger support points. Is provided, and means for detecting the skew angle and angular velocity of the load is provided.A detection signal from the detection means is input, a natural cycle of the load skew is calculated from a moment of inertia of the load, and a skew attenuation signal is calculated. A control means for outputting to a gripping operation mechanism of a hoisting rope wound around a support point disposed at a diagonal position of the hanging device is provided, and a hoist at a diagonal position of the hanging device support point is provided. The skew operation of the lifting gear is enabled by adjusting the loop tension, and while measuring the skew angle and angular velocity of the suspended load, the hoisting tension at the diagonal position of the lifting gear is opposite to the measured skew rotation. The skewing is controlled so that when the skew occurs due to the displacement of the center of gravity of the suspended load, etc., this is detected and controlled so that the skew is minimized, thereby improving the cargo handling efficiency. It can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a trolley part equipped with a skew steadying device according to an embodiment.

FIG. 2 is a configuration conceptual diagram of a skew angle measuring device.

FIG. 3 is a skew control block diagram.

FIG. 4 is a flowchart of skew control.

FIG. 5 is a perspective view of a rope hook of a crane provided with a skew steadying device according to a second embodiment.

FIG. 6 is a perspective view of a rope hook of a crane equipped with a skew steadying device according to a third embodiment.

FIG. 7 is an explanatory diagram of a tension balance mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Crane main body 11 Traversing trolley 12 Hoisting drum 14 Hoisting rope 16 Hanging tool 18 Container 20 End sheave 22 Elevating guide sheave 24 Hanging tool sheave 26 Gripping tool 28 Actuator 30 Skew device 32 Support bracket 34 Actuator 36 Left and right tilting and resting device 38 Target 40 CCD camera 42 Motor drive control unit 44 Measurement unit 46 Vibration suppression signal drive signal generation unit 48 Subtractor 50 trolley 52 Skew steadying tension control sheave 54 Tension balance mechanism 56 Tension control guide sheave 58 Front / back / left / right tilting device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyotaka Matsukuma 3-1-1, Tamano-shi, Tamano-shi, Okayama Mitsui Engineering & Shipbuilding Co., Ltd. (72) Inventor Toru Takehara 3-1-1, Tamano-shi, Tamano-shi, Okayama Mitsui Engineering & Shipbuilding Co., Ltd. Tamano Works

Claims (3)

[Claims] 1. A method for preventing a skew of a suspended load using a crane having a four-point lifting device, wherein a lifting guide sheave provided on a trolley corresponding to a lifting device support point is arranged in line symmetry and adjacent to the lifting device. The distance between the pair of lifting and lowering guide sheaves is larger than the distance between the lifting gear support points and is disposed at a fixed position on the trolley, and the lifting gear is adjusted by adjusting the tension of the hoisting rope at the diagonal position of the lifting gear support point. The skew operation is enabled, and while measuring the skew angle and angular velocity of the suspended load, the hoist is controlled by controlling the hoisting tension at the diagonal position of the hoisting tool so as to have a phase opposite to the measured skew rotation. Method to prevent skew of suspended crane load. 2. A suspension device for a suspended load using a crane having a four-point suspension device, wherein a lifting guide sheave provided on a trolley side corresponding to the suspension device support point is arranged in line symmetry, and a pair of adjacent ones is provided. The elevating guide sheave interval is set to be wider than the hanger support point interval, and a hoisting rope gripping operation mechanism that is wound around a support point disposed at a diagonal position of the hanger is provided, and the skew angle of the hoist load and Angular velocity detection means is provided, a detection signal from this detection means is input, a load skew natural period is calculated from a moment of inertia of the load, and a skew attenuation signal is provided at a support point disposed at a diagonal position of the lifting device. A skew steadying device for a suspended load of a crane, further comprising control means for outputting to a gripping operation mechanism of a hoisting rope to be wound. 3. The device according to claim 2, wherein the skew angle is measured, and feedback control is performed by a computer so as to minimize the skew angle.