Method for winding cable around a cable reel for power supply to a crane lifting device

Abstract

To provide a perpendicular-winding-type cable reel for feeding power to a suspension tool suspended from a crane, the cable reel reducing the risk of cable disconnection short-circuiting or cable random winding caused by stand bending in the cable.SOLUTION: A cable CA is coated with a lubricant GR in order to prevent the phenomenon of twisted winding of the cable CA when the cable CA about to be wound on an already wound cable CA climbs the cable and is then wound due to winding of the cable CA drooped in a vertical direction on a cable CA wound in a spiral shape on a cable drum CD of a perpendicular-winding-type cable reel RE.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a method for winding a cable on a vertical winding cable reel for supplying power to a hoisting tool suspended by a hoisting device installed on a club trolley of a crane. [Background technology]

[0002] In a vertical winding cable reel for supplying power to a hoisting device suspended from a crane, the cable being wound onto the cable reel is subjected to tension due to the cable's own weight, and the cable reel rotates the cable drum of the cable reel with a torque strong enough to overcome this tension and wind up the cable, winding the cable. In the process, the cable is subjected to large pulling forces, bending forces, and twisting forces, and is used in a harsh manner that causes severe damage to the cable, so there is a demand for technologies to alleviate this damage, and for example, methods such as those described in Patent Documents 1 to 3 have been proposed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-260684 A [Patent Document 2] JP 2018-162147 A [Patent Document 3] JP 2021-66553 A Summary of the Invention [Problem to be solved by the invention]

[0004] Due to space limitations, vertical winding cable reels installed on the club trolley of a crane use either a multi-row, multi-layer winding drum or a multi-row, single-layer winding drum. In this type of drum, the cable is wound in a spiral shape around the cable drum, but the section of cable being wound is pulled straight down vertically, so that it always rides up on the adjacent cable that is already wound. At this time, the rubber coating (sheath material) on the surface of the cable being wound grips the rubber coating (sheath material) on the surface of the adjacent cable that has already been wound, and the cable being wound is twisted as it is wound. The twisting that occurred at this time caused damage to the cable.

[0005] Incidentally, Patent Document 3 describes a method for calculating the radius from the center of the cable drum for each layer of cable wound on a cable reel, and calculating the cable sagging length and the corresponding cable sagging weight from the amount of cable pulled out from that position, and also describes a method for calculating the torque that the sagging cable applies to the cable drum by multiplying the radius and weight. However, the radius when the cable is wound is not the radius at the point where the cable has finished being wound, but the point where the cable rides over the adjacent cable when being wound. Therefore, the radius when the cable is wound is larger than the radius described in Patent Document 3. If the cable winding torque is calculated based on the calculation in Patent Document 3, the winding torque will be smaller than the required torque, resulting in a cable being unbalanced due to insufficient winding torque.

[0006] In view of this problem, the present invention aims to provide a vertical winding type cable reel for supplying power to a hoisting device suspended from a crane, which reduces the risk of cable breakage or short circuit due to bending of the wires inside the cable, and of the cable being wound irregularly. [Means for solving the problem]

[0007] In order to solve the above problems, the cable winding method for a cable reel for powering a crane hoisting tool of the present invention is a vertical winding type cable reel for powering a hoisting tool suspended from a crane, characterized in that the drum type for winding the cable around the cable drum of the cable reel is a multi-row winding (multi-row, multi-layer winding or multi-row, single-layer winding) drum type, and by applying a lubricant to the surface of the cable to be wound around the cable reel, the cable hanging down vertically is wound on top of the cable that has already been wound in a spiral shape, thereby preventing the cable to be wound on top of the already wound cable from riding up and being twisted when being wound.

[0008] In this case, the lubricant may be a mineral oil.

[0009] In addition, when a cable hanging down vertically is wound on top of a cable that is already wound in a spiral shape around a cable drum, the cable to be wound on top of the already wound cable first rides up, and then the torque to wind the cable is calculated by adding the distance from the center of the cable drum to the center position of the already wound cable of the layer of cable to be wound, plus the ride-up distance of the cable to be wound on the already wound cable, and this distance is used as the fulcrum radius to calculate the load torque acting on the cable drum by the weight of the hanging cable, and this can be reflected in the value of the winding torque.

[0010] Furthermore, the frictional resistance between the cables that occurs when the riding cable is wound onto the cable drum, the transmission loss that occurs between the reel drive motor and the cable drum, and the acceleration torque for accelerating the inertial force of the rotating part of the cable drum and the moving body of the cable can be calculated and reflected in the value of the winding torque. Effect of the Invention

[0011] According to the cable winding method for a cable reel for power supply to a crane hoisting device of the present invention, it is possible to eliminate twisting of the cable that occurs when winding a vertically wound cable, prevent damage to the cable, and prevent irregular winding due to insufficient cable winding torque. This makes it possible to prevent cable damage due to irregular winding and problems such as the cable climbing over the flange of the cable drum and falling off, thereby improving the reliability of the cable reel. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic explanatory diagram of a crane for implementing a cable winding method for a cable reel for power supply to a crane hoisting tool according to the present invention; [Diagram 2] FIG. 2 is an explanatory diagram of the structure of an electric cable reel. [Diagram 3] FIG. 2 is an explanatory diagram of a type of drum of a cable reel. [Figure 4] 1A to 1C are explanatory diagrams of the movement of a cable when it is wound onto a cable reel. [Diagram 5] FIG. 13 is an explanatory diagram of the dimension of a hanging cable climbing over an adjacent cable. [Figure 6] FIG. 4 is an explanatory diagram of a winding state of the cable. [Figure 7] FIG. 13 is an explanatory diagram of what happens when a cable is twisted. [Figure 8] FIG. 1 is an explanatory diagram of a cable defect example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a cable winding method for a cable reel for power supply to a crane hoisting tool according to the present invention will be described with reference to the drawings.

[0014] FIG. 1 shows an example of a crane for carrying out the cable winding method for a cable reel for power supply to a crane hoisting gear of the present invention. The hoisting device GB, which is completely supported by a wire rope WR, is suspended from the wire drum WD on the club trolley TR of the crane CR, and the hoisting device GB is raised and lowered solely by the rotational force of the wire drum WD. A cable CA is hung down under constant tension from the cable reel RE located next to the wire drum WD, fixed with a fixing bracket FS, and powered by the hoisting device GB. The cable reel RE always generates a winding torque in the winding direction, keeping the cable CA under tension. When the hoisting gear GB is wound down, the cable CA wound around the cable reel RE is pulled out while maintaining a tension due to the winding torque of the cable reel RE. When the hoisting gear GB is wound up, the cable CA is wound around the cable reel RE while maintaining a tension due to the winding torque of the cable reel RE. At this time, the winding torque of the cable reel RE is set to a weak torque that only supports the cable CA and the fixing bracket FS and does not support the load of the hoisting fixture, but is set to a weak torque that only follows the up and down movement of the hoisting fixture GB.

[0015] FIG. 2 shows an example of the structure of an electric cable reel. The cable CA wound around the cable drum CD is connected to a slip ring SR through the hollow shaft SH from the cable drum, and is electrically connected to the rotating cable CA from a fixed wiring. The reel drive motor DM connected to the hollow shaft SH generates a predetermined rotational torque controlled by the detection of the rotational position detector PG, and transmits it to the cable drum CD via the hollow shaft SH, generating a torque to wind up the cable CA.

[0016] Figure 3 explains the types of cable drum CD. Figure 3 (1) shows a single-row, multi-layer winding drum. Due to its narrow cable drum width and large outer diameter, it is widely used for power supply while gantry cranes are traveling. Figure 3(2) shows a multi-row, multi-layer winding drum, and Figure 3(3) shows a multi-row, single-layer winding drum. The cable winding method for a cable reel for power supply to a crane hoisting equipment of the present invention is intended for the multi-row, multi-layer winding drum of Figure 3(2) and the multi-row, single-layer winding drum of Figure 3(3), which are shaped so that they can be placed even in a narrow space above the club trolley TR.

[0017] FIG. 4 illustrates how to wind a cable onto a multi-row, multi-layer winding drum. The cable CA, which is pulled out from inside the cable drum CD from the cable pull-out position CO, is wound in a spiral shape with one cable CA shifting sideways by one turn per 360°. Meanwhile, the hanging cable CA to be wound is pulled vertically, starting from the drum apex A, and heading straight toward the drum horizontal point B while climbing over the adjacent cable CA that is already spirally wound, this point becoming the drum hanging point CAL, and the overlap with the adjacent cable CA at this point is 0.5r for 90°, whereas the cable is wound with a shift of 2r over 360°. Here, r is the radius of the cable. The cable riding dimension X in this case is as shown in Figure 5, and is calculated as 1.32r from formula (1). X 2 =(2r) 2 -(1.5r) 2 ··· Equation (1) X=1.32r

[0018] The weight hanging down from the cable sagging point CAL at this time is calculated by multiplying the weight per unit length of the cable by the sagging length L plus the weight of the fixing bracket, and the torque applied from the cable side to the cable drum is calculated by multiplying this total weight by the winding radius R. However, this winding radius R is not the first layer radius R1 described in Patent Document 3, but the first layer radius R1 plus the run-up dimension X. Therefore, a torque greater than the torque described in Patent Document 3 is applied from the cable side during winding. Therefore, if the winding torque is set using the calculation method described in Patent Document 3, a torque shortage will occur, and in reality, only the run-up dimension X must be added to the support radius of each layer. In addition, the spiral of the cable wound around the drum is not a perfect spiral, but rather meanders slightly, so it is safe to set the cable ride-over dimension X to one cable's length (2r) over 1.32r.

[0019] At the drum horizontal point B, the cable hanging point CAL is located at the riding position, and when the cable drum winding RU is performed, the riding cable CA moves from the drum horizontal point B to the drum apex A, and a twist RO occurs in the cable CA as it gets stuck in the cable drum CD. Then, when the first layer is finished and the second layer begins according to the cable winding sequence CT, the spiral direction of the cable CA reverses, so the direction of the twist RO also reverses, and the cable is wound in a spiral shape while being twisted. Figure 6 (1) shows the state in which cable CA moves from the drum horizontal point B toward the top of the drum. After riding on the adjacent cable CA at the cable hanging point CAL, the rubber coating on the surface of the cable that is being wound from the cable hanging point CAL grips the circumference of the rubber coating (sheath material) on the surface of the cable CA, which has already been wound in a spiral shape, and the cable is wound onto the cable drum CD while generating a twist RO.

[0020] At this time, the core wires of the cable are twisted in a certain direction, as shown in Figure 7. When a twist is applied in the same direction as the twist direction TW of this core wire, the core wire is pulled and tightened, exerting a strong resistance, but when a twist RO is applied in the opposite direction to the twist direction TW of the core wire, as shown in Figure 7, the core wire is untwisted, and a core wire bend BD occurs as shown in Figure 8, causing the wire to break and tear the insulation, resulting in a short circuit with the adjacent core wire, or the core wire breaking, resulting in other problems. Whether the twist direction TW of the core wires is the same or opposite depends on the position of the cable pull-out position CO and the winding direction, but in the case of a multi-row, multi-layer type, the first and second layers are twisted in opposite directions, so cable defects due to twist RO will occur in either the first layer (odd layer) or the second layer (even layer).

[0021] In the case of the multi-row single-layer cable drum shown in Figure 3 (3), twist RO continues to be applied in the same direction while the multiple rows are wound, and the accumulation of twist RO becomes enormous in the part where the cable CA is fully wound. Even if the twist direction TW of the core wire and the twist RO direction are the same in the part wound around the cable drum CD and the core wire is tightened, a twist opposite to the amount of twist that was applied while being wound around the cable drum CD occurs in the hanging part, so in this case the core wire untwists in the hanging part near the fixing bracket, causing a core wire bend BD as shown in Figure 8. In this way, even if the winding direction of a multi-row, single-layer cable drum is devised, problems will occur either in the hanging part or in the part being wound. If a twist RO occurs in the cable CA, the core wire bend BD shown in Figure 8 cannot be avoided.

[0022] The mechanism of irregular winding that occurs when the winding torque is set smaller than the required torque while a twist RO occurs during winding of the cable CA is described with reference to Figures 6(1) and (2). When the cable approaches the end of the layer with twisted twist RO, the amount of twisted twist RO accumulates. At this time, if the winding torque is insufficient, the force that tries to pull the cable toward the cable drum CD and wind it will be greater than the force that tries to lift the cable onto the adjacent cable CA in an attempt to return the twisted twist RO due to the repulsive force of the accumulated twisted twist RO. , the cable will completely ride up on the adjacent cable CA, causing a haphazard winding. Once this occurs, it becomes impossible to wind the cable in an orderly manner, and the cable ends up climbing up onto the cable CA. In the worst case scenario, the cable may climb over the drum flange DT and fall off DP, making it impossible to continue operating the crane. This phenomenon occurs in both multi-row, multi-layer winding and multi-row, single-layer winding. Even if this irregular winding phenomenon does not result in a DP falling off phenomenon, it will disrupt the twist of the core wire CC, causing a short circuit between the core wires in the cable CA or a break in the wire.

[0023] The torque required to prevent random winding during winding is not calculated in the static state as described in Patent Document 3, but is calculated by adding the riding dimension X, which is the dynamic state of the cable when it is wound, to the static cable position of each layer, which is taken as the fulcrum radius, and multiplying this fulcrum radius by the load applied to the hanging portion of cable CA to calculate the load torque. Furthermore, if necessary, the frictional resistance between the cables when pulling the riding cable CA in the direction of the cable drum CD, the transmission loss occurring between the reel drive motor DM and the cable drum CD, and the acceleration torque for accelerating the inertial force of the rotating parts such as the cable drum CD and the moving bodies such as the cable CA can be calculated and reflected in the value of the winding torque. By generating the above required torque, the random winding phenomenon can be prevented.

[0024] Furthermore, in the cable winding method for a cable reel for power supply to a crane hoisting gear of the present invention, in order to eliminate twists RO that cause cable defects, a lubricant GR is applied generously to the surface of the cable CA. Here, "applying generously" means applying a generous amount by hand to fill in the gaps in the cable CA when installing the crane CR, which allows the applied state to be maintained for several years to about 10 years. When the lubricant GR is applied generously to the surface of the cable CA, as shown in Figure 6 (3), the cable CA to be wound rides on top of the adjacent cable CA that is already spirally wound, and then slides down onto the cable drum CD without the surface of the adjacent cable CA and the surface of the cable to be wound gripping each other, without the occurrence of twisting RO.

[0025] When considering only the relationship with the chloroprene rubber that is the rubber coating (sheath material) on the surface of cable CA, it is desirable to use silicone oil, which has long-term stability, for the lubricant GR. However, silicone oil dries out in a short period of time, which has the disadvantage of requiring more frequent maintenance. For this reason, in this embodiment, a mineral oil-based grease that can ensure lubrication for a long period of time is used. Although mineral oil-based grease deteriorates chloroprene rubber over the long term, this chemical deterioration is outweighed by the extension of the life of the cable CA by preventing mechanical damage to the cable CA due to twisting RO.

[0026] The effect of applying lubricant GR to cable CA is to prevent the occurrence of core wire bending BD inside the cable by eliminating twisting RO, and also to eliminate the twisting of cable CA caused by twisting RO in the hanging part of cable CA, and the constraint of hanging cable CA due to twisting is eliminated, allowing the hanging cable CA to move flexibly.In addition, the risk of disordered winding is reduced because the rise of adjacent cables due to twisting RO is eliminated.

[0027] The above describes the cable winding method for a cable reel for power supply to a crane hoisting gear of the present invention based on an embodiment thereof. However, the present invention is not limited to the configuration described in the above embodiment, and the configuration can be appropriately changed without departing from the spirit of the present invention. [Industrial Applicability]

[0028] According to the cable winding method for a cable reel for power supply to a crane hoisting device of the present invention, it is possible to eliminate the twisting of the cable that occurs when winding the cable on a cable reel with a multi-row, multi-layer drum or a multi-row, single-layer drum, and to eliminate the associated cable defects. Furthermore, by clarifying the fulcrum radius at which the load of the hanging portion of the cable acts on the cable drum when winding the cable, it is possible to calculate an accurate load torque, and therefore the present invention can be effectively used industrially in operating cable reels. [Explanation of symbols]

[0029] CR Crane TR Club Trolley WD Wire Drum WR Wire Rope GB hanging equipment RE Cable Reel CA Cable FS Fixing Bracket L Hanging length CD Cable Drum SH hollow shaft DM Reel drive motor PG Rotational Position Detector BR Brake Bottom bracket bearing TB terminal block SR slip ring CB Carbon Brush CT cable winding order CAL cable drop point R1 1st layer radius R2 2nd layer radius R3 3rd layer radius R Winding radius CO cable outlet position A Drum Apex B Drum horizontal point C Drum bottom point RU Winding RO Twist r Cable radius X Ride-on dimension GR Lubricant DT Drum Tsuba DP dropout CC core wire TW Core Wire Twist Direction BD core bending

Claims

1. A method for winding a cable on a vertical winding type cable reel for supplying power to a hoisting device suspended from a crane, comprising the steps of: The cable reel is configured such that a method of winding the cable around a cable drum is a multi-row winding method in which the cable is wound around the cable drum in a spiral shape, A lubricant is applied to the surface of the cable wound around the cable drum, When a vertically hanging cable is first placed on top of a cable already wound in a spiral shape and then wound around it, the rubber coating on the surfaces of the cables does not grip each other, preventing the cable from being twisted. A method for winding a cable onto a cable reel for power supply to a crane hoisting tool, comprising:

2. 2. The method for winding a cable onto a cable reel for power supply to a crane hoisting gear according to claim 1, wherein the lubricant is made of mineral oil.

3. A cable winding method for a cable reel for power supply to a crane lifting device as described in claim 1 or 2, characterized in that the support radius used to calculate the load torque of the cable reel is the dimension obtained by adding the dimension from the center position of the cable drum to the center position of the already wound cable plus the climbing dimension of the cable that first climbs up over the already wound cable and then is wound.

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