JP2005170668A - Crane with wire load fluctuation reducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crane equipped with a wire load fluctuation reducing device capable of prolonging the lifetime of a wire by reducing certainly the load fluctuation applied to the wire and thereby reducing the impact stress on the wire owing to the load fluctuation and of sensing the replacement time by grasping certainly the lifetime of the wire using a very simple and convenient means. <P>SOLUTION: The wire load fluctuation reducing device of the crane is structured so that the wire hanging down a heavy object at one end is wound up by a winch device through a sheave so as to hang up the heavy object, and is equipped with a hydraulic device to generate oil pressure through the action of the bearing load of the sheave transmitted from the wire and an oil pressure fluctuation absorbing device connected with the hydraulic device for damping the fluctuation of the oil pressure, wherein the load fluctuation of the wire is converted by the hydraulic device into fluctuation in the oil pressure, and the load fluctuation of the wire is damped by absorbing the oil pressure fluctuation by the absorbing device. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is applied to a ship deck crane or the like, and winds a heavy wire suspended around a sheave supported rotatably on a support member via a bearing, and winds the other end of the wire. The present invention relates to a crane configured to lift the heavy object by winding it through the sheave by means of an apparatus, the crane having a wire load fluctuation reducing device.

In a ship deck crane, for example, Patent Document 1 (Japanese Patent Laid-Open No. 10-218555) is a means for reducing tension of a cable (wire) suspended from a heavy object, that is, a wire load, within an allowable range and reducing the slack of the cable. Technology).
In such a technique, a rotational drive source that rotates the cable reel, and a rotational force accumulation means that is interposed between the rotational drive source and the cable reel and that exerts a resilient force in the winding direction of the cable, The tension of the cable is set based on the range of elastic force generated by the rotational force accumulating means, the tension applied to the cable is kept within the controlled range, and the slack of the cable when the crane is stopped is reduced and the cable is wound. The applicability to high speed devices is improved, and the size of the rotary drive source that drives the cable is reduced.

Japanese Patent Laid-Open No. 10-218555

In a jib crane used for a ship deck crane or the like, the load applied to the wire changes abruptly at the start of handling or immediately before the end of handling, and a large impact stress acts on the wire due to the change in the wire load.
However, in the prior art disclosed in Patent Document 1, the tension of the cable is set within the range of the elastic force in the rotational force accumulating means that applies the elastic force in the winding direction of the wire (cable). Therefore, the tension range of the cable is kept within the allowable range. For this reason, in such a prior art, when the impact load as described above is applied to the wire, the impact load can be alleviated to some extent by the change of the elastic force in the rotational force accumulating means, but the magnitude rapidly increases. It is difficult to reliably absorb a changing impact load, and a large impact stress may act on the wire, leading to the cutting of the wire.
Moreover, in this prior art, it is impossible to grasp the life and replacement time of the wire from the load state applied to the wire.
And so on.

  Therefore, in view of the problems of the prior art, the present invention can reduce the load fluctuation applied to the wire, thereby reducing the impact stress of the wire due to the load fluctuation and extending the life of the wire. It is an object of the present invention to provide a crane equipped with a wire load fluctuation reducing device capable of reliably grasping the life of a wire by simple means and detecting the replacement time.

  The present invention achieves such an object. A wire having a heavy object suspended at one end is wound around the outer periphery of a sheave rotatably supported by a support member via a bearing, and the other end of the wire is wound up. A crane configured to lift the heavy object by being connected to a device and winding the wire through the sheave by the hoisting device, wherein the bearing load of the sheave transmitted from the wire A hydraulic device that generates hydraulic pressure by the action of, and a hydraulic pressure fluctuation absorbing device that is connected to the hydraulic device and attenuates the fluctuation of the hydraulic pressure, and converts the load fluctuation of the wire into the hydraulic fluctuation by the hydraulic device, A clay equipped with a wire load fluctuation reducing device, characterized in that the load fluctuation of the wire is reduced by absorbing the oil pressure fluctuation by a hydraulic pressure fluctuation absorbing device. Located in.

  In this invention, preferably, the hydraulic device causes the bearing load to act on a piston fitted in a cylinder so as to be capable of reciprocating, and the bearing load is applied to an oil chamber formed between the piston and the cylinder. The oil pressure fluctuation absorbing device includes an accumulator connected to the oil chamber via an oil passage, and a throttle mechanism provided in the oil passage, and the throttle action by the throttle mechanism And a volume effect by the accumulator is configured to attenuate hydraulic pressure fluctuations in the oil chamber and the oil passage.

  According to this invention, the bearing load that acts on the sheave bearing that supports the sheave around which the wire is wound is applied to the piston that is fitted in the cylinder of the hydraulic device so as to be slidable back and forth. The hydraulic pressure generated by the bearing load is generated in the oil chamber formed between the piston and the cylinder, and the throttle action by the throttle mechanism provided in the oil passage connected to the oil chamber and the volume effect by the accumulator Since the oil pressure fluctuation in the oil chamber and the oil passage is attenuated, even if the load applied to the wire suddenly changes at the start of cargo handling, just before the cargo handling ends, the sheave bearing according to the load fluctuation Changes in load are converted into hydraulic pressure fluctuations acting on the oil chamber of the hydraulic device, and two damping actions, a throttle action by the throttle mechanism of the hydraulic fluctuation absorber and a volume effect by the accumulator Therefore, it is possible to reduce reliably absorb the load variation.

  Further, the present invention winds a wire with a heavy object suspended at one end around the outer periphery of a sheave supported rotatably on a support member via a bearing, and connects the other end of the wire to a hoisting device. The crane is configured to lift the heavy object by winding the wire through the sheave by the hoisting device, and generates hydraulic pressure by the action of the bearing load of the sheave transmitted from the wire. And a hydraulic pressure fluctuation detecting means for detecting the hydraulic pressure fluctuation in the hydraulic equipment, the detected value of the hydraulic pressure fluctuation from the hydraulic pressure fluctuation detecting means and the permissible value of the hydraulic pressure fluctuation are compared, and it is necessary to replace the wire. A crane provided with a wire load fluctuation reducing device characterized by comprising a wire exchange determining means for determining whether or not.

  In this invention, preferably, the hydraulic pressure fluctuation detecting means includes a pressure gauge that is provided in an oil path connected to the hydraulic device and detects the hydraulic pressure of the oil path, and a pressure fluctuation pulse of the hydraulic pressure detected by the pressure gauge. A pressure pulse counter that detects the number of pressure peaks of the pressure fluctuation pulse based on the pressure pulse counter, and the wire replacement determination means includes a calculated value of the number of pressure peaks from the pressure pulse counter and a preset allowable value of the number of pressure peaks. And determining whether or not the wire needs to be replaced based on the comparison result.

  According to this invention, the bearing load acting on the sheave bearing due to the load of the wire is applied to the piston fitted in the cylinder of the hydraulic device so as to be able to reciprocate and is formed between the piston and the cylinder. A pressure gauge for generating a hydraulic pressure due to the bearing load in the oil chamber and detecting a hydraulic pressure of an oil passage connected to the hydraulic device, and a pressure for detecting a pressure peak number of a pressure fluctuation pulse of the hydraulic pressure detected by the pressure gauge A hydraulic pressure fluctuation detecting means constituted by a pulse counter detects a cumulative value of the number of pressure peaks of the pressure fluctuation pulse and inputs it to the wire exchange determining means. In the wire exchange judging means, the cumulative value of the number of pressure peaks The detected value of the pressure peak and the allowable number of pressure peaks are compared, and based on the comparison result, the detected value of the accumulated value of the pressure peaks, that is, the accumulated value of the actual pressure peaks is When the wire number exceeds the allowable number of wires, it is necessary to replace the wire, assuming that the wire has reached its fatigue limit due to pressure fluctuations acting at the number of pressure peaks exceeding the allowable number. judge.

  Therefore, according to this invention, the change in the bearing load of the sheave bearing is converted into the hydraulic pressure fluctuation acting on the oil chamber of the hydraulic device due to the load of the wire, and the cumulative number of pressure peaks of the hydraulic fluctuation is converted into the pressure of the hydraulic fluctuation detecting means. When the cumulative value of the number of pressure peaks is greater than the allowable number of pressure peaks, pressure fluctuations act on the wire with the number of pressure peaks greater than the allowable number. Since the replacement of the wire is determined as having reached the fatigue limit of the wire, the cumulative value of the number of pressure peaks of the hydraulic pressure fluctuation due to the change in the bearing load of the sheave bearing is detected, It is possible to reliably grasp the life of the wire and detect the replacement time by an extremely simple and simple means of comparing the two.

  According to the present invention, when the load applied to the wire changes abruptly, the change in the bearing load of the sheave bearing due to the load change is converted into the hydraulic pressure change acting on the oil chamber of the hydraulic device, and the change in the hydraulic pressure is absorbed. The load fluctuation can be reliably absorbed by the two damping actions of the drawing mechanism of the device and the volume effect of the accumulator, and the impact stress of the wire due to the load fluctuation is reduced and the life of the wire is extended. can do.

  According to the present invention, the change in the bearing load of the sheave bearing due to the load of the wire is converted into the hydraulic pressure fluctuation acting on the oil chamber of the hydraulic device, the cumulative value of the number of pressure peaks of the hydraulic fluctuation is detected, and the pressure When the cumulative number of peaks exceeds the allowable number of pressure peaks, it is determined that the wire has reached its fatigue limit, and the replacement of the wire is determined. By detecting the accumulated value of the number of pressure peaks and comparing the accumulated number of pressure peaks with the allowable number of accumulated values of the pressure peak, the life of the wire is reliably grasped by an extremely simple and simple means, and the replacement time is detected. it can.

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.
FIG. 1 is a configuration diagram of a wire load fluctuation reducing device in a marine deck crane according to an embodiment of the present invention, and FIG. 2 is a control block diagram of a wire exchange determining means in the embodiment. FIG. 3 is a schematic front view showing the overall structure of a marine deck crane to which the present invention is applied.

In FIG. 3 showing the overall structure of a marine deck crane to which the present invention is applied, 2 is a hoisting device, 5 is a crane column, 1 is a jib supported by the crane column 5 so as to be raised and lowered, 4 is a control panel, Reference numeral 3 denotes a turning device for turning the jib 1 and the crane column 5.
20 is a sheave rotatably supported on the crane column 5 via a sheave bearing (see FIG. 1), 6 is a sheave rotatably supported on the tip of the jib 1 via a sheave bearing (not shown), 8 Is a wire that supports a heavy object (load) 7 and is wound around the outer periphery of the sheave 6 and the sheave 20 from the heavy object (load) 7 and connected to the hoisting device 2.
When the deck crane is in operation, the wire 8 with the heavy object 7 suspended at one end is wound or fed by the hoisting device 2 through the sheaves 6 and 20 to lift or lower the heavy object 7. It is like that.

The present invention relates to a wire load fluctuation reducing device for reducing fluctuations in wire load acting on the wire 8 in the crane.
In FIG. 1 showing an embodiment of the present invention, a sheave bearing 18 is attached to the tip of the crane column 5 (see FIG. 3) and rotatably supports a sheave shaft 17 to which the sheave 20 is fixed. ing.
As described above, the wire 8 is wound around the outer periphery of the sheave 6 and the sheave 20 from the heavy load (load) 7 and then connected to the hoisting device 2 (see FIG. 3).

Reference numeral 40 denotes a hydraulic device, which is configured as follows.
Reference numeral 11 denotes a cylinder fixed to the support shaft 14, and 12 denotes a piston fitted in the cylinder 11 so as to be slidable back and forth. Two pistons 12 are radially connected to the lower part of the sheave bearing 18 so as to support the lower part of the sheave bearing 18 from two directions, and the cylinder and the support shaft 14 are provided for each piston 12. Each said spindle 14 is rotatably supported by the support bearing 15 fixed to the said crane support | pillar 5 (refer FIG. 3).
By configuring in this way, it becomes possible to cause the bearing loads in the two directions acting on the sheave bearing 18 to act on the two pistons 12 provided in the two directions.

Reference numeral 13 denotes an oil chamber formed in each cylinder 11 so as to face the end face of each piston 12, and the oil is sealed and filled with the oil chamber by the movement of the piston 12 due to a bearing load as described later. The hydraulic oil in 13 is compressed to generate hydraulic pressure.
23 is an oil pipe connected to the two oil chambers 13, 21 is an accumulator connected to the oil pipe 23, and 22 is a throttle mechanism provided at a position near the accumulator 21 of the oil pipe 23. The hydraulic pressure generated in the chamber 13 is transmitted to the throttle mechanism 22 and the accumulator 21 through the oil pipe 23. The diaphragm mechanism 22 may be a variable diaphragm or a fixed diaphragm.
24 is a pressure gauge for measuring the pressure of the hydraulic oil in the oil pipe 23, 25 is a pressure pulse counter, 30 is a wire exchange determination device, and details thereof will be described later.

Next, based on FIG.1 and FIG.2, operation | movement of the wire load fluctuation reduction apparatus which consists of this structure is demonstrated.
The wire load of the wire 8 by the heavy object 7 is supported by the sheave bearing 18 and the two pistons 12 via the sheave 20 and the sheave shaft 17. When the wire load changes at the start of cargo handling, just before the end of cargo handling, etc., the sheave bearing 18 and the two pistons 12 supporting the sheave bearing 18 are reciprocally displaced according to the bearing load fluctuation of the sheave bearing 18 due to the load fluctuation. To do. The reciprocating displacement of the piston 12 generates hydraulic pressure (hydraulic pressure fluctuation) in the oil chamber 13 where the hydraulic oil is sealed and filled.
The hydraulic pressure fluctuation is transmitted to the throttle mechanism 22 and the accumulator through the oil pipe 23, and the hydraulic pressure fluctuation is attenuated by the throttle action (so-called dashpot action) by the throttle mechanism 22 and the volume effect by the accumulator. This reduces the variation in the wire load.

  Since this embodiment is configured as described above, the inside of the oil chamber 13 and the oil pipe 23 is caused by the throttle action by the throttle mechanism 22 provided in the oil pipe 23 connected to the oil chamber 13 and the volume effect by the accumulator 21. Even if the wire load applied to the wire 8 changes suddenly at the start of handling or just before the end of handling, the change in the bearing load of the sheave bearing 18 due to the change in load is detected by the hydraulic device 40. The load variation is converted into a hydraulic pressure fluctuation acting on the oil chamber 13 by two damping actions, a throttle action (dashpot action) by the throttle mechanism 22 constituting the hydraulic fluctuation absorber and a volume effect by the accumulator 21. It is possible to reliably absorb and reduce.

Next, in FIGS. 2A and 2B, the pressure gauge 24 measures the oil pressure (hydraulic fluctuation) of the oil pipe 23 (both see FIG. 1) connected to the oil chamber 13 of the hydraulic device 40. Input to the pressure pulse counter 25. In the pressure pulse counter 25, as shown in FIG.
The accumulated value of the pressure peak P ₁ is detected (counted) from the pressure fluctuation pulse waveform P of the hydraulic pressure measurement value from the pressure gauge 24 and is input to the pressure pulse comparison unit 31.
Reference numeral 32 denotes an allowable pulse number setting unit, which sets the allowable pulse number for the pressure peak P ₁ accumulated that requires the wire 8 to be replaced when the wire 8 reaches the fatigue limit due to the hydraulic pressure fluctuation due to the wire load fluctuation.

Wherein the pressure pulse comparator unit 31 compares the allowable number of pulses of the pressure peak P ₁ detected (counted) cumulative value and the pressure peak P ₁ total, and inputs the comparison result to the wire exchange determination unit 33. In the wire exchange determination unit 33, based on the comparison result, the detection value that is the actual number of pressure peaks in the total value of the pressure peak number of cumulative value becomes more than the allowable number of pulses of the pressure peak P ₁ Total In some cases, it is determined that the wire 8 needs to be replaced because it has reached the fatigue limit of the wire 8 due to the pressure fluctuation acting on the wire 8 with the number of pressure peaks exceeding the allowable number.
The determination result is displayed on the display device 26, and the operator performs the work of replacing the wire 8 according to the display.

Therefore, according to such an embodiment, the wire 8 into a oil pressure change acting changes in bearing load sheave bearing 18 to the oil chamber 13 of the hydraulic device 40 by the load, the pressure peak P ₁ number of cumulative value of the oil pressure change was detected by the pressure gauge 24 and a pressure pulse counter 25, the when the cumulative value of the pressure peak P number ₁ becomes more than the allowable number of pressure peak number of pressure peaks P ₁ exceeding the allowable number in the wire 8 load variation in a few acts, as reaching the fatigue limit of the wire, so to determine the replacement of the wire 8, the cumulative value of the pressure peak P number ₁ of the hydraulic fluctuation due to changes in bearing load sheave bearing 18 detected, that is compared with the cumulative value allowable number of pressure peak P number _1, and surely grasp the very simple and convenient means of wire I than life, can detect the replacement time.

  According to the present invention, it is possible to extend the life of the wire by reducing the impact stress of the wire due to the load variation by reliably reducing the load variation applied to the wire that suspends the heavy object, and it is extremely simple and simple. By means of this, it is possible to provide a crane equipped with a wire load fluctuation reducing device capable of reliably grasping the life of a wire and detecting its replacement time.

It is a block diagram of the wire load fluctuation reduction apparatus in the ship deck crane which concerns on the Example of this invention. It is a control block diagram of the wire exchange determination means in the embodiment. It is a schematic front view which shows the whole structure of the ship deck crane to which this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Jib 2 Hoisting device 3 Swivel device 5 Crane support | pillar 6,20 Sheave 7 Heavy load 8 Wire 11 Cylinder 12 Piston 13 Oil chamber 14 Support shaft 17 Sheave shaft 18 Sheave bearing 22 Throttle mechanism 23 Oil pipe 24 Pressure gauge 25 Pressure pulse counter 26 Display device 30 Wire exchange determination device 40 Hydraulic device

Claims (4)

  A wire having a heavy object suspended at one end is wound around the outer periphery of a sheave rotatably supported by a support member via a bearing, and the other end of the wire is connected to a hoisting device. In a crane configured to lift the heavy object by winding the wire through the sheave, a hydraulic device that generates hydraulic pressure by an action of a bearing load of the sheave transmitted from the wire, and the hydraulic pressure A hydraulic pressure fluctuation absorbing device connected to a device to attenuate the fluctuation of the hydraulic pressure, converting the load fluctuation of the wire into the hydraulic pressure fluctuation by the hydraulic pressure device, and absorbing the hydraulic pressure fluctuation by the hydraulic pressure fluctuation absorbing device. A crane equipped with a wire load fluctuation reducing device configured to reduce the load fluctuation of the wire.   The hydraulic device causes the bearing load to act on a piston fitted in a cylinder so as to be reciprocally slidable, and generates hydraulic pressure due to the bearing load in an oil chamber formed between the piston and the cylinder. The hydraulic fluctuation absorber includes an accumulator connected to the oil chamber via an oil passage, and a throttle mechanism provided in the oil passage, and a throttle action by the throttle mechanism and a volume effect by the accumulator The crane provided with the wire load fluctuation reducing device according to claim 1, wherein the crane is configured to attenuate hydraulic pressure fluctuation in the oil chamber and the oil passage.   A wire having a heavy object suspended at one end is wound around the outer periphery of a sheave rotatably supported by a support member via a bearing, and the other end of the wire is connected to a hoisting device. In a crane configured to lift the heavy object by winding the wire through the sheave, a hydraulic device that generates hydraulic pressure by an action of a bearing load of the sheave transmitted from the wire, and the hydraulic pressure Oil pressure fluctuation detecting means for detecting the oil pressure fluctuation in the apparatus, and wire exchange determination for comparing the detected value of the oil pressure fluctuation from the oil pressure fluctuation detecting means and the allowable value of the oil pressure fluctuation to determine whether the wire needs to be exchanged A crane equipped with a wire load fluctuation reducing device.   The oil pressure fluctuation detecting means is provided in an oil passage connected to the hydraulic device and detects the oil pressure of the oil passage, and the pressure fluctuation pulse based on the pressure fluctuation pulse of the oil pressure detected by the pressure gauge. A pressure pulse counter that detects the number of pressure peaks of the pressure pulse, and the wire replacement determination means compares the detected value of the number of pressure peaks from the pressure pulse counter with a preset allowable number of pressure peaks. 4. The crane provided with the wire load fluctuation reducing device according to claim 3, wherein the crane is configured to determine whether or not the wire needs to be replaced based on a comparison result.

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