JP7147597B2 - Crane wire replacement method - Google Patents

Description

The present invention relates to a crane wire replacement method.

For example, horizontal retractable cranes located along quay walls are used to load and unload cargo from docked vessels. In various cranes represented by this horizontal retractable crane, the wire used to open, close and move the bucket that carries the load is the most important functional part of the crane. Methods, etc. are stipulated by law, and it is necessary to replace them periodically from the viewpoint of ensuring safety.

When replacing these wires, it is necessary to remove the heavy old wires and attach new wires through a large number of sheaves composed of pulleys, protective covers, etc., due to the basic structure of the crane.

Conventionally, this wire replacement is performed by attaching an old wire to be replaced (herein referred to as "old wire to be replaced") to a new wire for replacement (herein referred to as "new replacement wire"). (see Patent Documents 1 to 3), or connect the old wire to be replaced and the new wire for replacement to both ends of a separately prepared "wire rope grip" (see Patent Document 4), and connect While hoisting both the wires in the state of being hoisted with a hoisting machine such as a winch, the "old wire to be replaced" guides the "new wire for replacement" to a predetermined route, passes through many sheaves, and feeds the new wire to the crane. A properly installed replacement method was widely practiced (see Patent Documents 1 to 4).

However, when two heavy wires, the old and the new, are connected and introduced into a plurality of sheaves through a complicated route, it is necessary to mechanically pull them in using a winch or the like. In the work of pulling these by a machine with a constant pulling force, the pulling with a constant force continues while the twisted part of the wire and the connection part between the old and new wires are caught in the sheave part with bends and narrow parts. There are times when it is done. As a result, the "new wire for replacement" may be damaged, resulting in economic and time loss due to replacement, and in the worst case, the connection between the old and new wires may be broken and the wire may be lost. There was also the possibility of a very dangerous situation of falling. In addition, when a device such as a winch, which is dedicated to wire replacement, is required, unnecessary labor and costs are incurred.

JP-A-61-192697 JP-A-63-17792 JP-A-3-272998 JP 2007-137557 A

In the wire replacement work of a crane, the present invention prevents damage to the new wire for replacement and breakage of the connection between the old and new wires that occurred when the wire was wound by a machine, thereby improving the work efficiency of the wire replacement work. and to improve safety.

Instead of connecting a new wire for replacement to the old wire to be replaced and pulling the new wire for replacement mechanically using a power machine, the inventor of the present application uses a lightweight resin guide rope as a dummy in a predetermined route. By temporarily replacing with , it becomes possible to draw in a new wire for replacement by human power without using a power machine. Specifically, the present invention provides the following.

(1) A method for replacing a wire of a crane, in which the end portion of the old wire to be replaced on the rotating drum side is removed from the rotating drum, and the end portion of the old wire to be replaced on the rotating drum side is swiveled. By connecting to a resin guide rope for replacement work via a type shackle and pulling the old wire to be replaced in a direction away from the rotating drum along the wire movement path, the resin a step of removing the old wire to be replaced, in which the terminal portion of the guide rope is pulled to a wire replacement work position, and the connection between the old wire to be replaced and the resin guide rope is released at the wire replacement work position; A new wire for replacement is connected to the end of the resin guide rope via the swivel shackle, and the resin guide rope is pulled along the wire movement path toward the rotating drum. , the end portion of the new wire for replacement is drawn to a position near the rotating drum, and the connection between the new wire for replacement and the resin guide rope is released at a position near the rotating drum, and the replacement is performed. and a new replacement wire attaching step of attaching the terminal portion of the new wire to the rotating drum.

(2) The end portions of the old wire to be replaced and the new wire for replacement are joined with a connection nut when connected to the resin guide rope, and the resin guide rope includes a plurality of A string-shaped resin material is twisted, and a connection ring is formed at the end of the resin guide rope by weaving a connection ring hardware with the resin material, (1) The crane wire replacement method described in .

(3) The crane wire replacement method according to (1) or (2), wherein the crane is a horizontal retractable crane.

(4) The crane wire replacement method according to any one of (1) to (3), wherein the crane has a turning radius of 20 m or less.

(5) The wire replacement method according to any one of (1) to (4), wherein the old wire to be replaced and the resin guide rope are towed manually in all steps.

According to the present invention, in the wire replacement work of a crane, it is possible to prevent damage to the new wire for replacement and breakage of the joint between the new and old wires that occurred when the wire was wound by a machine, thereby making the wire replacement work easier. It can improve work efficiency and safety.

FIG. 3 is a schematic diagram showing a wire hooking method (installation mode) in a "horizontal retractable crane," which is a specific example of a crane that can be replaced with a wire by the crane wire replacement method of the present invention. FIG. 4 is a side view of a terminal portion of a new wire for replacement used in the crane wire replacement method of the present invention. FIG. 4 is a side view of the end portion of the resin guide rope used in the crane wire replacement method of the present invention. FIG. 4 is a side view of a peripheral portion of a connection portion of a connection body between a new wire for replacement and a resin guide rope according to the present invention; FIG. 4 is a cross-sectional view of a sheave portion schematically showing a state in which a connected body of a new wire for replacement and a resin guide rope passes through the sheave portion when the method for replacing a wire of a crane according to the present invention is carried out. FIG. 10 is a side view of a peripheral portion of a connection portion of a connecting body between a new replacement wire and an old wire to be replaced according to a conventional crane wire replacement method. FIG. 10 is a cross-sectional view of a sheave portion schematically showing a state in which a connecting body between a new replacement wire and an old wire to be replaced passes through the sheave portion when a conventional crane wire replacement method is carried out. FIG. 4 is a schematic diagram showing an embodiment of a "process for removing an old wire to be replaced" in the crane wire replacement method of the present invention. FIG. 4 is a schematic diagram showing an embodiment of a "step of attaching a new wire for replacement" in the crane wire replacement method of the present invention.

Hereinafter, the details of the crane wire replacement method of the present invention will be described. INDUSTRIAL APPLICABILITY The present invention can be widely applied and implemented to wire replacement work of various cranes in addition to horizontal retraction cranes.

<Crane to which the wire replacement method of the present invention is applied>
As described above, the wire replacement method of the present invention can be widely applied to wire replacement in various cranes. It can be preferably applied to replace the wire of a "horizontal retractable crane" that operates by passing through a number of sheaves. In this specification, the maximum turning radius refers to the maximum distance from the rotation axis that can be reached by a loading device such as a grab bucket. When the maximum turning radius of a horizontal retractable crane is 18 m, the length of one wire is about 63 m, depending on the lifting height. As an example, a general-purpose carbon steel wire with an outer diameter of 20 mm weighs about 80 to 100 kg when the total length is 63 m. Up to this level of weight, it is sufficiently possible to be towed by a plurality of people (for example, about five people or less), which is suitable for the implementation of the present invention.

FIG. 1 is a diagram schematically showing the configuration of the main parts of such a "horizontal retractable crane" crane 100. As shown in FIG. In this figure, only the wires to be replaced in the wire replacement method of the present invention and the parts directly involved in the replacement are extracted to schematically show the configuration of the crane to which the present invention is applied.

As shown in FIG. 1, in a crane 100, a plurality of wires 1, one end of which is connected to a rotating drum 5, are provided with members such as various buckets and hooks for loading or suspending loads. It is arranged so as to move via a plurality of pulleys 41 to reach the other end where it is connected. This pulley 41 is normally provided with a protective cover (not shown in FIG. 1, see FIG. 5), and as shown in FIG. The crane 100 operates by moving in both directions while passing through the tight spaces between the protective covers 42 . In this specification, it is a route that connects the parts where the wire needs to be passed in order to operate the crane. shall be referred to as a "wire movement path".

As an example of the arrangement of the wires 1, as shown in FIG. 1, two wires with an outer diameter of 20 mm are used as the main winding wires, and two wires with an outer diameter of 20 mm are used as the opening and closing wires. and a structure for opening and closing operations. These wires need to be replaced periodically while checking the condition of the wires and operating hours. For example, in a horizontal retractable crane with a wire arrangement as shown in Fig. 1, it is common to replace the two main hoisting wires about once a year, and the two opening and closing wires about every three months. target.

Since the horizontal retraction crane described above is usually installed on a quay for landing, in the wire replacement, the old wire to be replaced and the new wire for replacement are connected as in the past, and the wire of the winch or the like is connected. In the case of using a device dedicated to wire replacement (see Patent Documents 2 and 3), the device must be installed on a remote quay each time a wire is replaced, which takes extra time and effort. The practice of the present invention avoids such extra effort and wasted time in wire replacement for horizontal retraction cranes.

In addition, in a specific type of crane such as an overhead crane (see Patent Documents 1 and 4), which is composed of a fixed pulley at a high place and a movable pulley pivotally supported by a hook block, the old wire to be replaced and the new wire to be replaced are used. It is possible to connect the wires and replace the wires using a rotary drum or the like already provided in the crane without using a device dedicated to wire replacement such as a winch. However, in the case of the horizontal retraction type crane with the structure shown in Fig. 1, even if the old wire to be replaced and the new wire for replacement are connected, the removal of the old wire to be replaced and the retraction of the new wire for replacement can be performed efficiently at the same time. cannot be done systematically. From this point of view, the wire replacement method for the crane of the present invention is particularly suitable as a method for replacing the wire of a horizontal retraction type crane among various cranes.

<Wire replacement method>
The crane wire replacement method of the present invention is a process composed of a "removal step of removing the old wire to be replaced" for removing the old wire to be replaced, and a "step of attaching the new wire for replacement" to newly attach the new wire for replacement. is. By effectively utilizing resin guide ropes in each process, the new process solves the above-mentioned problems of the conventional method and improves the work efficiency and safety of wire replacement work. be.

[Old wire removal process for replacement]
FIG. 8A is a drawing schematically showing an embodiment of the "process for removing the old wire to be replaced" among the above-described processes constituting the crane wire replacement method of the present invention.

In this step, first, the old wire to be replaced is let out in the direction away from the rotating drum, that is, toward the load to be hung, and the end portion of the old wire to be replaced 1B on the rotating drum 5 side is pulled out of the rotating drum 5. Remove from terminal fixing portion 51 . Then, the terminal portion of the old wire to be replaced 1B is connected to the resin guide rope 2 for replacement work via the swivel shackle 3 (see (1) to (3) in FIG. 8A).

The connection between the old wire to be replaced 1B and the resin guide rope 2 is performed by connecting a connecting nut 12 to the end portion of the old wire to be replaced 1B on the side of the connecting portion, which is connected to the swivel shackle 3. Then, the swivel shackle 3 and the connecting ring portion 22 of the resin guide rope 2 are spliced (see FIG. 8A (3)). The details of the method of joining the connection nut to each wire and the method of forming the connection ring portion to the guide rope will be described later.

Next, from the state in which the resin guide rope 2 is connected to the old wire 1B to be replaced (see FIG. 8A (3)), the old wire 1B to be replaced is moved from the rotating drum 5 along the "wire moving path". By pulling it away, the end of the resin guide rope 2 is pulled into the wire replacement work position (see FIG. 8A (4)). The wire replacement work position is near the tip of the arm of the crane, where the new wire for replacement can be safely placed as shown in FIG. Any position can be used as long as it is possible to secure a space where each work can be carried out safely. Moreover, in order to improve the working efficiency, it is preferable to perform the above-described work of pulling the end portion of the resin guide rope 2 to the wire replacement work position at this wire replacement work position.

It is preferable that the pulling work of the old wire 1B to be replaced is performed manually by an appropriate number of people according to the required pulling force. This is because, in the case of human power, the pulling force can be immediately and flexibly adjusted when a sudden resistance force is generated against the pulling force. As a result, it is possible to avoid the deterioration of work efficiency and the occurrence of dangers that often occur when old and new wires are towed by mechanical power. In addition, if the new wire for replacement is connected to the old wire for replacement and the pulling work is performed manually, the weight will increase and the machine oil that adheres to the surface of the old wire for replacement will cause slippage, so the number of people will be reduced. Even if you increase it, the work will be extremely difficult. By temporarily replacing the guide rope with a lightweight resin guide rope as a dummy in a predetermined route, it becomes possible to perform towing work by human power.

Finally, at the wire replacement work position, the connection between the old wire to be replaced 1B and the resin guide rope 2 is released to complete the removal of the old wire to be replaced 1B (see FIG. 8A (5)). .

[New replacement wire installation process]
FIG. 8B is a drawing schematically showing an embodiment of the "new replacement wire attaching process" that is performed subsequent to the "old replacement wire removing process".

In this process, first, the end of the new replacement wire 1A is connected to the resin guide rope 2 through the swivel shackle 3 (see (1) and (2) in FIG. 8B).

The new wire for replacement 1A and the resin guide rope 2 are connected by joining a connection nut 12 to the end portion of the new wire for replacement 1A on the side of the connecting portion, and joining this with the swivel type shackle 3. , by joining the swivel type shackle 3 and the connecting ring portion 22 of the resin guide rope 2 (see FIG. 8B (2)). Details of a method of joining each connection nut to each wire and a method of forming a connection ring portion to the guide rope will be described later.

Next, from the state in which the resin guide rope 2 is connected to the new replacement wire 1A (see FIG. 8B (2)), the new replacement wire 1A is moved in the direction of the rotating drum 5 along the "wire movement path". By pulling the new wire 1A for replacement, the end portion of the new wire 1A for replacement is drawn to a position near the rotating drum 5 (see FIG. 8B(3)).

It should be noted that, in the process of installing the new wire for replacement as well, it is preferable to manually perform the pulling operation of the resin guide rope 2 in the process of removing the old wire to be replaced by an appropriate number of people according to the required pulling force. . In the wire replacement work of a crane, which is generally performed once every three months, the replacement method of the present invention is used to manually pull the new replacement wire 1A connected to the resin guide rope 2. Therefore, work efficiency and safety can be improved more than the conventional method.

Then, at a position near the rotary drum 5, the connection between the new replacement wire 1A and the resin guide rope 2 is released, and the terminal portion of the new replacement wire 1A is attached to the terminal fixing portion 51 of the rotary drum 5. , complete the installation of the new replacement wire 1A (FIG. 8B(4)).

[New replacement wire]
In the wire replacement method of the present invention, as shown in FIG. 2, a new replacement wire 1A having a wire 11 with a connection nut 12 joined to the end portion thereof is used. The wire 11 is not particularly limited, and the present invention can be applied to a wire having a thickness that can sufficiently secure the strength and durability required for each crane.

The connection nut 12 may be any ring-shaped metal fitting that can be joined to the end of the swivel shackle 3 . As such hardware, for example, a hexagonal nut or the like, which is a general-purpose item and is easily available, can be used. As for the size of the connection nut 12 , the maximum width and maximum thickness should be such that the connecting portion between each wire and the resin guide rope can smoothly pass through the sheave portion 4 .

It is preferable to weld the connection nut 12 to the wire 11 to obtain the replacement new wire 1A. This welding can also be performed on the end portion of the new replacement wire 1A each time the process of attaching the new replacement wire (immediately before (1) in FIG. 8B) is started. is joined to the terminal portion of the wire 11, and a necessary number of new replacement wires 1A are prepared for the next replacement, thereby further improving the working efficiency of the replacement work.

As a specific example of a preferred embodiment of the new wire for replacement 1A, a carbon steel wire having an outer diameter of 20 mm and an SS400 nut for M12 is welded and fixed to the end of the wire. This welding is preferably performed in a state in which the end portion of the wire 11 is cleaned to remove oil before welding, and one side of the hexagonal surface of the SS nut for M12 is pressed against the end portion. The strength of this welded portion may be set to an appropriate strength according to the weight of the wire to be replaced. It is fully possible to set the tensile strength of the fixed part to 200 kg or more, which allows safe replacement of a carbon steel wire with an outer diameter of 20 mm and a length of 63 m.

In addition, it is preferable to join the connection nut 12 to the end portion of the old wire to be replaced 1B (see FIG. 8A(2)) in the "step of removing the old wire to be replaced" by welding in the same manner as described above. Also, the connecting nut 12 used in this case can be made of the same material, shape and size as described above.

[Resin guide rope]
In the wire replacement method of the present invention, as the resin guide rope 2, as shown in FIG. 22 is used. Any resin rope 21 may be used as long as it can sufficiently secure the strength necessary for the total weight of the wires to be replaced. As an example, the weight of 63 m of carbon steel wire with an outer diameter of 20 mm is about 80 to 100 kg, while the weight of a vinylon rope of the same diameter and length is about 10 kg at most. is.

As such a resin rope that constitutes the resin guide rope 2, for example, a Cremona rope made of vinylon, which is a general-purpose product and is easily available, can be preferably used. However, the resin rope is not limited to this, and as required, various resin ropes made of polypropylene resin, polyester resin, etc., as long as they have the necessary strength as described above. can also be used.

The resin guide rope 2 is preferably formed by twisting a plurality of string-like resin materials. In this case, as shown in FIG. It is preferable that the structure is formed by weaving the connecting ring hardware 221 into the material. By adopting such a structure, the required strength can be imparted to the connecting ring portion 22 by a method that is easy to implement. The strength of the connecting ring portion 22 may be set appropriately according to the weight of the wire to be replaced. is sufficiently possible to safely replace a carbon steel wire with an outer diameter of 20 mm and a length of 63 m.

The formation of the connection ring portion 22 in the resin guide rope 2 can be performed each time the wire replacement method of the present invention is performed. By preparing the resin guide rope 2 in which the portion 22 is formed in advance, it is possible to further improve the working efficiency of the replacement work. Also, the resin guide rope 2 having the connecting ring portion 22 can be used repeatedly within a range permitted in terms of its durability.

As a specific example of a preferred embodiment of the resin guide rope 2, a Cremona rope with an outer diameter of 4 mm is woven into the tip of a Cremona tape made of vinylon with an outer diameter of 18 mm to form a ring, and a connecting ring fitting is placed in this ring. 221 are woven to form the connection ring portion 22 having a diameter of 20 mm.

[Swivel type shackle]
In the wire replacement method of the present invention, as the swivel type shackle 3, a metal fitting for connection as shown in FIG. 4 can be used. The swivel-type shackle 3 is a metal fitting for connection in which two shackles 32 arranged at both ends of the metal fitting can be freely rotated with respect to a rotating shaft 31 connecting them. By using the swivel type shackle 3 having such a structure as a metal fitting for connection, it is possible to eliminate the twisting of the wire that causes the wire to be caught in the sheave portion 4 . In particular, since the new replacement wire 1A is prepared in a wound state, "twisting", so-called "kinking", always occurs when returning to a straight state. If the kink causes the wire to become a ball, it not only becomes impossible to draw in the new replacement wire 1A, but also the wire may be damaged, leading to a wire breakage accident. Therefore, conventionally, the wire is sent out by making one rotation in the axial direction every time the wire is sent out one round. However, it was also heavy and the work was extremely difficult. With the introduction of the swivel shackle, the kink problem was eliminated.

Also, the swivel shackle 3 may have a maximum width and a maximum thickness that allow the connection between each wire and the resin guide rope to smoothly pass through the sheave portion 4 . In addition, the maximum width and maximum thickness are preferably 2 times or less, more preferably 1.0 times or less, of the outer diameters of the wires constituting the old wire to be replaced and the new wire for replacement. . By using the swivel-type shackle 3 having such a shape and size as a metal fitting for connection, it is possible to prevent the connecting portion between each wire and the resin guide rope from being caught in the sheave portion 4 .

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. In a horizontal retractable crane using a carbon steel wire with a total length of 63 m and an outer diameter of 20 mm as a crane wire, the effect of improving work efficiency and safety by adopting the wire replacement method of the present invention was confirmed.

<Comparative example (conventional wire replacement method)>
Conventionally, as shown in FIG. 6, the ends of the old wire to be replaced and the new wire to be replaced are overlapped within a range of 400 mm in length, and these portions are tightened and fixed at five locations with wires. Both wires are connected, the old wire to be replaced is used as a guide for pulling, and the connecting body 20 of the new wire to be replaced and the old wire to be replaced is mechanically pulled by a rotating drum to replace the wire. was

In this case, as shown in FIG. 7, the connecting portion between the two wires has a maximum cross-sectional dimension (W2) of 40 mm due to the superimposition. The work was often delayed due to the connection part being caught in the gap between them and the connection part being damaged due to this. In addition, the work is performed while the worker visually confirms whether or not it is caught. Therefore, work efficiency is low even when such problems do not occur.

<Example (wire replacement method of the present invention)>
In order to solve the above-mentioned problems in wire replacement in the comparative example, the replacement method was changed to the replacement method of the present invention. Specifically, as shown in FIG. 4, a very lightweight resin guide rope 2 is used as a towing guide, and the maximum width of the connecting part, including the swivel shackle 3, is 25 mm. . As the connection nut, an SS400 nut for M12 was appropriately welded and fixed to the end of the wire. Then, the four wires were replaced by manually pulling the connecting body 10 of the old wire to be replaced (or the new wire for replacement) and the resin guide rope.

In this case, as shown in FIG. 5, the maximum dimension (W1) of the cross-sectional shape of the connecting portion between the two wires is 25 mm, and the swivel shackle 3 eliminates the twisting of the wires, so the four wires that were replaced In all cases, the wires, including the connection portion, did not get caught when passing through the sheave portion 4. From this result, it can be seen that according to the present invention, it is possible to improve the working efficiency and safety of the crane wire replacement work.

1 wire for crane 1A new wire for replacement 1B old wire to be replaced 11, 11A, 11B wire 12 nut for connection 2 resin guide rope 21 resin rope 22 connection ring portion 221 connection ring hardware 3 swivel shackle 31 rotation Axis 32 Shackle 4 Sheave Part 41 Pulley 42 Protective Cover 5 Rotating Drum 51 Terminal Fixing Part 10 Connection of New Wire for Replacement and Resin Guide Rope 20 Connection of New Wire for Replacement and Old Wire to be Replaced 100 Crane

Claims (4)

A crane wire replacement method comprising:
removing the end of the old wire to be replaced on the side of the rotating drum from the rotating drum;
connecting the end portion of the old wire to be replaced on the rotating drum side to a resin guide rope for replacement work via a swivel shackle,
By pulling the old wire to be replaced in a direction away from the rotating drum along the wire movement path, the end portion of the resin guide rope is pulled to a wire replacement work position,
an old wire to be replaced removing step of disconnecting the old wire to be replaced from the resin guide rope at the wire replacement work position;
A new wire for replacement is connected to the end of the resin guide rope via the swivel shackle, and the resin guide rope is pulled along the wire movement path toward the rotating drum. , the end portion of the new wire for replacement is drawn to a position near the rotating drum, and the connection between the new wire for replacement and the resin guide rope is released at a position near the rotating drum, and the replacement is performed. a new replacement wire attaching step of attaching the end portion of the new wire for replacement to the rotating drum;
comprising
A connection nut is joined to the end portions of the old wire to be replaced and the new wire for replacement when connecting to the resin guide rope,
The resin guide rope is formed by twisting a plurality of string-like resin materials, and a connection ring metal is woven with the resin material at the end of the resin guide rope to form a connection ring. formed,
How to replace the wire of the crane. 2. The crane wire changing method according to claim 1 , wherein said crane is a horizontal retractable crane. The crane wire replacement method according to claim 1 or 2 , wherein the crane has a turning radius of 20 m or less. 4. The wire replacement method according to any one of claims 1 to 3 , wherein the old wire to be replaced and the resin guide rope are towed manually in all steps.

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