JPH0616175A - Working method for upper structure of ship - Google Patents

Abstract

PURPOSE:To provide a distortion preventing upper structure working method which can extremely restrain the occurrence of distortion and leads to the improvement in automation while remarkably reducing the manhour for removing distortion. CONSTITUTION:Plural deck steel plates 1 or wall steel plates are mutually butted and disposed on a level block, and angle beams 2 each of which comprises a flange 2a and a web 2b are arranged side by side parallel to a plate joint 4 on the steel plate 1. After the flange 2a of the beam 2 and only one side corner area of the opposite web 2b are continuously welded with the substantially minimum welding leg length by using an automatic welding machine, the plate joint 4 area of the steel plate 1 is welded, and a large rib girder 3 is placed in a designated position and fitted there. Subsequently, the whole of the joined steel plates 1 is reversed and the opposite plate joint 4 area is welded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction method for preventing distortion from occurring as much as possible when constructing a deck or wall board structure in a superstructure of a ship in which a relatively thin plate is used as a ship. .

[0002]

2. Description of the Related Art In the superstructure A shown in FIG. 4 of the hull structure of a ship, a relatively thin steel plate (4.5 to 8 mm) is used as a ship for its deck 1 and wall plate 1A. , If a beam or stiffener is attached by welding,
Frequent distortion due to welding. Therefore, various techniques have been conventionally made in order to prevent distortion from occurring in the work of such a frame.

A conventional working method will be described with reference to FIGS. FIG. 5 is a plan view showing the frame structure of the deck. Beams 2 are attached to the steel plate 1 at regular intervals in a direction orthogonal to the plate joints 4, and a girder 3 which is a large bone in a direction orthogonal to the beam 2. Is attached. Further, distortion preventing curling 8 is attached between the beams 2 at a predetermined interval. When machining such a frame structure, first, as shown in FIG. 6 (a), a plurality of long steel plates 1 are butted side by side on a surface plate, and the plate joints 4 on the long sides thereof are welded on one side. . At that time, as shown in the drawing, the steel plate 1 is deformed by the thermal stress due to welding. Next, as shown in FIG. 7B, the joined large plates are inverted (dragonfly) to weld the plate joint 4 on the opposite side. Even at this stage, the deformation of the steel plate 1 due to the first welding remains as it is. Therefore, the beam 2 is temporarily attached in a direction orthogonal to the welded plate joint 4 including the meaning of correcting it as shown in FIG. 3C, and then the girder 3 and the distortion preventing curling 8 are placed on the steel plate 1. It is fixed by juxtaposing it at a predetermined position and temporarily attaching it. And finally, these main weldings are performed. In this case, the beam 2 is welded by staggered welding as shown in FIG. 7 (a). W1, W
Reference numerals 2 and W3 indicate welding lines thereof, and both corners of the beam 2 are alternately and intermittently welded as shown in FIG.
This is one of the ideas for reducing the welding heat input and preventing the distortion of the steel sheet 1 as much as possible. Since it is effective to reduce the area of the boneless panel for preventing distortion, the distortion preventing curling 8 is attached between the beams 2 at a predetermined interval.

[0004]

As described above, despite various efforts to prevent distortion, the occurrence of distortion is still unavoidable, and a lot of man-hours and labor are required for removing the distortion. Is the current situation. This is mainly due to the fact that zigzag welding of beams cannot be performed using an automatic welding machine and therefore must be performed by hand welding by an operator. In other words, when it comes to hand welding,
As shown in FIG. 7 (b), the welding leg length a and the like largely depend on skill and intuition, and in the usual case, the leg length exceeds 5 mm, and the variation is large. Further, the welding speed and the like are not constant, so that rather, the amount of heat input during welding is large and unstable, and distortion occurs. Therefore, originally, the curling for distortion prevention is not necessary in terms of design (in terms of strength), but it is provided for the purpose of preventing the above distortion. However, since the number of beams in the upper structure is very large, the number of curling is inevitably large, and the number of man-hours required for mounting the curling is enormous. In addition to the time and labor required for installation, it is necessary to separately create a curling layout drawing and draw the position of each curling line on site. In addition, it is necessary to pre-mark the positions and pitches at which staggered welding is performed. In addition, since the plate joint of the steel plate runs in the direction orthogonal to the beam, it is not possible to attach the beam in advance, which hinders the realization of automation.
The result does not meet the demand for labor saving.

In view of the present situation, an object of the present invention is to construct a superstructure that suppresses the occurrence of distortion as much as possible without providing a curling for preventing distortion, and greatly improves the automation while reducing the number of distortion removing steps. To provide the law.

[0006]

In order to achieve the above-mentioned object, a method of working a superstructure according to the present invention is to place a plurality of steel plates on a surface plate in abutment with each other, and to form a flange and a web on the steel plates in parallel with the plate joint. The angled beams consisting of and are placed side by side, and only one side corner of the web on the side opposite to the flange of the beam is continuously welded using an automatic welding machine with a substantially minimum welding leg length, and then the plate joint portion of the steel plate is It is characterized in that welding is performed, a girder having a large bone is placed at a predetermined position and attached, and then the entire joined steel plates are inverted to weld the plate joint portion on the opposite side.

[0007]

[Operation] By arranging the angled beam parallel to the plate joint between steel plates, it is possible to attach the beam in advance in the stage of small assembly, and prevent distortion even when welding steel plates in the subsequent large assembly process. On the other hand, continuous welding makes it possible to introduce an automatic welding machine, and it is possible to manage welding conditions related to welding heat input such as welding speed and welding leg length. In addition, it is possible to prevent distortion of the steel sheet as much as possible by controlling the steel sheet to the minimum required. Such a construction method effectively reduces the strain of deck steel plates and wall steel plates of the superstructure formed of a relatively thin plate for a ship, and significantly reduces the number of man-hours required for strain relief work and curling mounting work for strain prevention. While contributing to the improvement of productivity, the automation of such work will be expanded.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a framework of, for example, a deck structure of an upper structure to which the present invention is applied, and FIGS. 2 (a) to 2 (c) are perspective views, perspective views, and the like in which the working method according to the present invention is expressed over time.
Side view, Figure 3 (a) (b) shows beam (in this example, deck beam)
2A is a plan view showing the situation of one-sided continuous welding, and a perspective view showing the situation of one-sided continuous welding by an automatic welding machine. FIG. 13C is a side sectional view showing the welding leg length after the beam is attached.

The upper structure A shown in FIG. 4 is different from the main structure B of the hull in that it does not pose a particular problem in terms of hull strength, and it is only necessary to consider the vibration due to the motive force of the main engine and propeller.
A relatively thin steel plate of about 4.5 to 8 mm is used for the deck 1 and the wall plate 1A as a ship. Normal,
The superstructure A consists of several layers of decks 1 in which living quarters are formed.

FIG. 1 is a frame structure view in which a part of the deck 1 is cut out. As shown in the figure, the back side (lower surface) of the deck 1 comprises a flange 2a and a web 2b as shown in FIG. Angled deck beam (also called beam)
2 are attached at substantially equal intervals, and girders 3, which are large bones, are attached at large intervals in a direction orthogonal to this. It is formed into a large plate by welding the plate joints 4 of the long sides of the long steel plate forming the deck 1.
One of the features of the present invention is that the beam 2 is arranged in parallel with the plate joint 4.

A method of working according to the present invention will be described with reference to FIGS. 2 and 3 in consideration of strain prevention in the case of such a frame structure. First, as shown by the solid line in FIG. 2 (a), a long steel plate (deck plate in this example) 1 is placed on a surface plate, and angled beams 2 are juxtaposed on the steel plate 1 at equal intervals. Fix it temporarily. Usually, three to four beams 2 are arranged on a steel plate 1 having a fixed width. Next, as shown in FIG. 3, one side corner of the web 2b opposite to the flange 2a of the beam 2 is continuously welded. W indicates the weld line. In this case, unlike conventional staggered welding,
Since it is continuous welding, a known automatic welding machine M can be used.
That is, as shown in FIG. 3 (b), the automatic welding machine M is placed on the flange 2a of the beam 2 and is run along the flange 2a to continuously and automatically weld one side of the beam 2. In the figure, 5 is a traveling carriage, 6
Is a welding torch, and 7 is a control / operation box for setting and managing welding conditions related to welding heat input such as welding speed, current value, voltage value, and welding leg length. Weld leg length a at this time
(See Fig. 3 (c)) keeps the required minimum leg length 3 to 4 mm constant. Since the automatic welding machine M can be used, unlike manual welding, it is possible to prevent the distortion of the steel sheet by uniformly controlling the conditions related to the welding heat input amount that causes distortion such as the welding leg length and the welding speed. Therefore, no curling for distortion prevention is required unlike the conventional method. Here, FIG.
As shown in (a) and (b), the reason for continuous welding only on one side of beam 2 with the minimum welding leg length is to suppress welding heat input to prevent distortion, and also to weld the opposite side of flange 2a. In addition to facilitating automatic welding, the beam 2 falls toward the flange 2a when a load is applied, and the corners of the web 2b of the welded portion (the portion to be welded) open.
This is because welding here can be effectively prevented, and even one-sided continuous welding with a short leg length does not hinder strength. In addition, even with one-sided welding, the girder 3 works as a fall prevention and there is no problem. In this way, at the small assembly stage, one side of all beams was continuously welded using an automatic welding machine and then attached, and then another beam was attached with beam 2 by the same machining method (dotted line in Fig. 2 (a)).
Together with the steel plate 1 so as to form the plate joint 4 in the large assembly stage
Butt each other and place them side by side on the surface plate. Then, the welding of the plate joint 4 is automatically welded to join the steel plates together. In this case, the pre-mounted beam 2 is near the welded joint, so that distortion of the steel sheet 1 is minimized. Next, the girder 3 is arranged as shown in FIG.
Install on top. Also in this case, since the beam 2 is attached in advance, distortion is unlikely to occur. Finally, as shown in FIG. 2 (c), the whole structure is inverted (dragonfly) and the plate joint 4 on the surface of the remaining steel plate is welded to complete the frame structure of the deck.

According to such a working method, since the beam direction is parallel to the plate joint, it is possible to pre-install the beam in the small set stage and prevent distortion during plate joint welding in the large set. , Installation of many beams,
Since automatic welding is used instead of manual welding as in the past, the number of installation steps can be greatly reduced. Moreover, the welding conditions are controlled to be constant, the welding leg length related to welding heat input can be controlled to the necessary minimum, and the welding speed can also be maintained at a constant level, so that the occurrence of distortion in the steel sheet is greatly reduced, and the distortion removal work in the post-process is performed. It will be possible to greatly reduce the labor required for.

Although the above embodiment relates to the deck (deck steel plate), it goes without saying that the same can be applied to the wall steel plate.

[0014]

According to the present invention described above, the following effects can be obtained. Since the beam is placed parallel to the plate joint of the deck steel plate or wall steel plate of the superstructure, it is possible to use an automatic welding machine when mounting the beam, and as a result, welding conditions such as welding speed and welding heat input can be controlled consistently. Since the required minimum welding leg length (usually 3 to 4 mm) can be obtained, it becomes possible to minimize the distortion of the steel sheet. By this,
It is possible to drastically reduce the man-hours and labor required for the strain removal work, which leads to a dramatic improvement in productivity. Since it is not necessary to attach a curling ring for preventing distortion, which was conventionally provided between the beams, it is possible to reduce the number of man-hours incidental to this, which leads to a significant cost reduction, and interior work such as heat insulation work is very easy. By arranging the beam in parallel with the plate joint of the deck, the beam can be preliminarily attached in the small set stage, and this can serve as distortion prevention by welding of the plate joint portion in the large set.

[Brief description of drawings]

FIG. 1 is a plan view showing a skeleton of a deck structure which is one of upper structures when the present invention is applied.

2 (a) to (c) are a perspective view, a perspective view, and a side view showing a working method according to the present invention with time.

[Fig. 3] (a) is a plan view showing the condition of continuous welding on one side of the beam, (b) is a side view showing the condition of continuous welding on one side of the automatic welding machine, and (c) shows the welding leg length after the beam is attached. It is a sectional side view shown.

FIG. 4 is a side view of the entire ship including the superstructure.

FIG. 5 is a plan view showing a frame structure of a conventional deck structure of an upper structure.

6 (a) to 6 (c) are perspective views showing a conventional working method over time.

7 (a) is a conventional beam zigzag welding situation diagram, (b)
Is a side sectional view thereof.

[Explanation of symbols]

 1 ... Deck (deck steel plate) 1A ... Wall steel plate 2 ... Beam 2a ... Flange 2b ... Web 3 ... Girder 4 ... Plate joint M ... Automatic welding machine

Claims (1)

[Claims] 1. A plurality of steel plates are placed on a surface plate in abutment with each other, an angle beam composed of a flange and a web is placed side by side on the steel plate in parallel with the plate joint, and the web on the side opposite to the flange of the beam is placed. After continuously welding only one corner with an automatic welding machine with almost the minimum welding leg length, weld the plate joint part of the steel plate, place the girder of the large bone at a predetermined position and attach it, and then weld the whole steel plate A method for constructing a superstructure of a ship, characterized in that the plate joint portion on the opposite side is welded by reversing.