JPS5830887A - Method of assembling leg of landing lift system maritime bench - Google Patents

Abstract

PURPOSE:To facilitate preparatory plan for welding while setting accurately pitch and direction of a rack by determining positions of the rack and an intermediate plate for welding with a locating member provided above and below the intermediate plate. CONSTITUTION:A support plate 9b for an upper cord 4b is mounted on a horizontal plate 10 which locates a lower cord 4a, to register intermediate plates 6a, 6b with racks 7a, 7b. After welding the support plate 9b and the horizontal plate 10, the intermediate plates 6a, 6b and racks 7a, 7b are welded so that the direction and pitch of the rack 7 can be accurately held.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for assembling legs of a landing lift type offshore work platform. More specifically, it is possible to precisely match the pitch of the racks of the legs assembled with a cord consisting of two semi-cylindrical cord materials, an intermediate plate, and two racks provided on both sides of the intermediate plate. A method of assembling the legs is provided.

A landing lift type offshore work platform usually has a plurality of polygonal legs with three or four cords connected by connecting rods, and a jacking device is installed on the workbench to control the jacking. The device is configured to engage the rack of the leg so as to move the workbench up and down along the leg. This glossing device is composed of a motor, a reducer, and a pinion which is the output end of this reducer, and the pinion is extended on both sides of the cord forming the leg. It has to fit together.

On the other hand, since the workbench is used in places where the water depth is 70m or more, the total length of the legs is 80 to 110m.
It also extends to Since it is extremely difficult to accurately assemble such a long leg, unit legs of about 5 to 20 m are manufactured and then welded to form the unit legs to the above length.

By the way, it is extremely difficult to accurately match the pitch of the chics installed on the sides of the long legs, which have a total length of 110m1C, and if this pitch is not accurate, the power will be transmitted more accurately than the pinion that meshes with the rack. There is a problem in that the workbench cannot be moved up and down smoothly.

To explain the above problem in more detail, the racks provided on both sides of one cord are engaged with pinions in multiple stages, and there are usually six to eight pinions.

According to the studies of the present inventors, the footing provided at the lower end of the leg is placed on the bottom, and the jacking device is operated to raise the workbench to a predetermined height, thereby maintaining a constant torque acting on each pinion. Even if these pinions are fixed, the torque may fluctuate due to an external force such as a storm. Also, if there are variations in rack pitch, straightness, etc., a certain pinion will exceed the allowable torque range, so if the power transmission system is designed with this in mind, the jacking device will be quite large and manufacturing will be difficult. The disadvantage was that the cost increased significantly.

As mentioned above, there are various problems in manufacturing the cords that make up the legs, and how accurately the legs are manufactured is important in determining the performance of a landing lift type offshore work platform.

The present invention has been achieved in order to solve the problems of the prior art, and includes providing a positioning member at the connecting portion of the cords, and after determining the connection position of both cords by the positioning member, the intermediate plate and The feature is that two racks are welded together.

Next, the present invention will be described in detail with reference to the drawings.

Fig. 1 is a diagram showing the main parts of a landing lift type offshore work platform.
The jacking device 2 is actuated to move the workbench 1 up and down along the legs 3.

FIG. 2 is a plan view of the leg portion 3 and the jacking device 2.
Three cords 4 are connected by a connecting rod 5 to form a triangular tower shape as a whole.

As will be described later, racks are provided on both sides of this cord, and the pinion of the jacking device 2 is engaged with the racks.

Figures 3 and 4 are diagrams showing the upper structure of code 4. Rack 7a is welded to both sides of intermediate plate 6a (shown), and a semi-cylindrical cord 8a is welded to connect both racks 7a. This cord material 8a is slightly shorter than the length of the rack 7a, and a distance L is provided between them. Further, two support plates 9a are radially welded to each side of the intermediate plate 6a, and a horizontal plate 10 is provided above the support plates 9a.

4 and 8, a horizontal plate 1 supported by a support plate 9a is shown.
A situation is shown where 0 is provided in the same plane as rank 7a. 6 and 7 are views showing the lower structure of the cord 4, in which two support plates 9b are provided radially on both sides of the intermediate plate 6b. This support plate 9b is similar to the upper structure of the cord 4 shown in FIGS. 3 and 4, but
The difference is that the horizontal plate 10 is omitted.

Next, the situation in which the cord 4 is connected according to the present invention will be explained.

As shown in FIG. 8, the lower part of the cord 4b is positioned above the cord 4a, the support plate 9b of the cord 4b is positioned on the horizontal plate 10, and the racks 7a and 7b of the cords 4a and 4b and the intermediate plates 6a and 6b are connected to each other. Perform alignment. For this positioning, a positioning member 11 (FIG. 10) extended from the support plate 9a is used.
is used.

After the intermediate plates 6a and 6b shown in circle A in Figure 10 are aligned, and the racks 7a and 7b shown in circle B in Figure 11 are aligned, these alignment parts are welded. . The reason why a distance of 2L is provided between the semi-cylindrical cord members 8a and 8b is to perform the above-mentioned welding, and this distance 2L is preferably selected based on the size of the cords and ease of welding work.

Now, the intermediate plates @a, $b and racks 7a, 7b
Once welded, parts of the support plates 6a, 6b and the horizontal plate 10 are removed by cutting the portion indicated by the two-dot chain line C in FIG.

Then, the open portions of the cord materials 6a and 13b are closed with another semi-cylindrical plate.

In addition, if it is better to connect the support plates 9a and 9b, the support plate from which the horizontal plate 10 has been removed may be welded to the position of the string.

As described in detail above, the present invention provides the support plate 9a and the horizontal plate 10 as positioning members on the upper part of the cord 4, and furthermore, the upper end of the cord material 8a is made shorter than the upper part of the rack 7a to create a gap. This is characterized in that a support plate 9b is provided on the intermediate plate 6b as a positioning member for the lower part of the cord, and the cord 8b is shortened so that the support plate 9b is exposed here.

Therefore, according to the present invention, the support plate for the upper cord 4b is placed on the horizontal plate 10, which is a positioning member for the lower cord 4a, and in this state, the intermediate plates 6a, 6b and the racks 7a, 7b are aligned. Then, the support plate 9b and the horizontal plate 10 are welded as necessary, and then the intermediate plate and the rack are welded, so that the pitch and direction of the rack can be maintained accurately.

When welding of the racks 7a, 7b, etc. is completed as described above, the opening required for this welding work is closed with a semi-cylindrical plate similar to another cord material, and welding of one cord is completed. . As shown in FIG. 2, one leg 3 is provided with three cords 4, so the welding of the cords is repeated to complete the connection of one leg 3.

In the present invention, since the racks and the like are aligned by the positioning member as described above, the preparation work for welding the legs is easy, and the pitch and direction of the racks can be adjusted accurately.

By joining the legs according to the present invention, it is possible to easily connect the legs, and as a result, the assembly work of the landing lift type offshore work platform can be carried out smoothly.

Further, according to the present invention, since the direction and pitch of the rack are accurately determined, the glossing device 2 that engages with the rack
Since the torque acting on the pinion is accurately distributed, the landing lift type offshore work platform can be operated safely.

[Brief explanation of the drawing]

FIG. 1 is a side view of the main parts showing the legs of the landing lift type offshore work platform. FIG. 2 is a plan view showing the engaged state of the leg and the jacking device. 3 and 4 are a front view and a side view showing the upper structure of the cord. FIG. 5 is a plan view of the upper structure of the cord. 6 and 7 are a front view and a side view showing the lower structure of the cord. FIG. 8 is a perspective view showing a state of preparation immediately before connecting the cord. FIG. 9 is a front view showing a state in which two cords are connected. FIG. 10 is a side sectional view showing the positioning state of the intermediate plate of the two cords. FIG. 11 is a side sectional view showing the positioning state of the rack. DESCRIPTION OF SYMBOLS 1... Workbench, 2... Jacking device, 3... Leg part, 4... Cord, 5... Connecting rod, 6a, 6b...
Intermediate plate, 7a, 7b --- rack, fJa,
8b-: 71 members, 9a. 9b...Support plate, 10...Horizontal plate. Agent Patent Attorney Makoto Ogawa - Patent Attorney Ken Noguchi Patent Attorney Kazuhiko Saishita Figure 2 Figure 4 Figure 5 b Figure 6 Figure 7 Figure 9 Figure 10 Figure 11

Claims (1)

[Claims] In a method for assembling a leg portion having a cord consisting of an intermediate plate, racks provided on both sides thereof, and a semi-cylindrical cord material connecting the racks, positioning members are provided above and below the intermediate plate, This positioning member determines the position of the rack and intermediate plate and welds them together.
How to assemble the legs of a landing lift type offshore work platform.