JPH0327113Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to an underwater walking workbench, and in particular, an underwater walking workbench equipped with a stable structure to maintain stability during ascent, diving, landing on the bottom, and walking. Regarding the workbench.

[Conventional technology]

As a conventional underwater walking workbench, there is one shown in FIG. 7, in which a buoyancy tank V is added separately from the strength member constituting the main body.

Further, as shown in FIG. 8, when the workbench lands on the bottom of the water, it is suspended by a crane ship and water is poured into a buoyancy tank to sink it.

[Problem that the invention attempts to solve]

By the way, in the conventional underwater walking work platform as described above, the buoyancy tank is added separately from the strength member of the main body, so the buoyancy tank does not have the function as a strength member, and the work platform alone cannot be used. ,
There is a problem in that sufficient stability cannot be maintained during ascent, diving, and landing on the bottom, and support from a crane ship or the like is required.

The present invention aims to solve these problems by providing a stable underwater walking platform that can float up and land safely without the use of support equipment such as a crane ship. It is an object.

In other words, by appropriately incorporating the buoyancy tank, which was previously added simply for buoyancy adjustment separately from the main body frame structure, into a part of the main body structure,
The same buoyancy tank has a function as a structural strength member,
The purpose is to have the function of maintaining stability during ascent, diving, and landing on the bottom.

[Means for solving problems]

For this reason, the safe structured underwater walking work platform of the present invention has two main bodies that intersect at right angles to each other, and is attached to the intersection of these two main bodies so that the two main bodies are vertically and horizontally relative to each other. In the underwater walking work platform, the above-mentioned 2.
Leg water tanks that can be filled with water are integrally provided on both sides of at least one of the main bodies, and at the top of these leg water tanks, there are separate compartments from the leg water tanks. It is characterized in that a buoyancy tank is integrally provided as a strength member of the main body.

[Effect]

In the above-mentioned stable underwater walking platform of the present invention, the water tank for all legs is empty during surfacing, and sufficient buoyancy is maintained together with the action of the buoyancy tank.

In addition, during the process of landing on the bottom, water is poured into the water tanks of the legs as appropriate to maintain a stable posture.
By providing the necessary column reaction force, the stability of the main body is maintained during work and walking.

〔Example〕

Next, an embodiment of the present invention will be described in detail. Figures 1, 2, and 3 show an underwater walking work platform according to the present invention. The girder-2 of the main body and the beam-2 of the main body are connected by the Y carrier,
For work or walking, it can be moved back and forth and left and right via a carrier by means of hydraulic cylinders (not shown) in the front and rear directions and in the left and right directions.
And pillars -4, -4 that perform the functions described below.
The main body is attached so that it can be protruded downward and retracted upward when the workbench is walked.

In this embodiment, work equipment such as a dredging machine (not shown) is mounted on the main body.

As shown in Figures 1, 2, and 3, side leg cargo water tank-1a, center leg cargo water tank-1b, and buoyancy tank-1c are arranged on the main body, and buoyancy tank-1 is arranged on the main body. Deploy.

When ascending, all the cargo water tanks are empty and the fourth tank is empty.
The state shown in FIG. 4A and FIG. 4B is obtained.

As shown in Figures 5a and 5b, during the landing process, a stable posture can be maintained by pouring all the water into the central landing gear tank 1b and partially filling the side landing gear tank 1a. .

After landing on the bottom, the entire amount of water is poured into the side leg water tank 1a to provide the necessary leg column reaction force R, so that the main body maintains stability even in the state shown in FIG. 6 during work or walking.

The main body functions as a working frame and is constructed as follows.

(1) The side leg cargo water tank-1a is provided symmetrically on both sides of the main body and integrally with the main body,
This provides structural strength, stability and buoyancy during ascent, leg water injection during diving, and underwater load when landing on the bottom.

(2) The central landing gear tank-1b, along with the girder-2, fixes the space between the side landing gear tanks and provides buoyancy during ascent, water injection during diving, and underwater load when landing on the bottom. It is.

(3) The buoyancy tank-1c is an integral structure with the side leg cargo water tank to serve as a strength member for the main body, providing stability during diving, and increasing safety as preliminary buoyancy during ascent. It is.

(4) Girder-2 is fixed between the side landing gear tanks and
-It is a main structural member of the main body that is also connected to the main body via the Y carrier, and the inside of this girder-2 can also be made a part of the central leg water tank-1b.

(5) The leg box-3 is a box that accommodates the leg column-4, and has a built-in hydraulic cylinder (not shown) to extend and retract the leg column.

(6) When working, ground the pillar-4 of the main unit,
Retract the pillar 4 of the main body.

When walking forwards and backwards and left and right, the pillars -4 and -4 are alternately brought into contact with the ground.

Next, the main body is a moving frame, and the working equipment is mounted on the main body.

(1) Buoyancy tank-1 is provided as necessary to obtain longitudinal stability during levitation, and does not particularly contribute to the strength of the main body. Buoyancy tank-1c can also be used for stability during diving, but
In order to adjust the center of gravity and the center of buoyancy, which are particularly problematic during diving, it is preferable to provide the buoyancy tank-1 with a fixed ballast because the center of buoyancy on the plane and on the side can be adjusted at the same time.

(2) Beam-2 is the main structural member of the main body, and is connected to the girder of the main body via the X-Y carrier.
It is connected to 2.

In FIG. 1, the amount by which the beam 2 extends forward and backward relative to the girder 2 is determined by the movement or walking stroke. Further, the distance between the beam 2 and the side leg water tank 1a is determined by the movement in the left and right direction and the walking stroke.

(3) The purpose of the leg box-3 is the same as that of the leg box-3 in the main body, and it accommodates the leg column-4 and expands and contracts the leg column-4 with a hydraulic cylinder (not shown).

(4) Pillar-4 is retracted during work;
When walking, it is used together with the pillar-4 and is alternately grounded.

In the stable structure of the underwater walking work platform of the present invention, when floating, the shape of the main body at the sea surface (water line surface) is as follows, with reference to FIG. 4 and FIGS. 4a, 4b, 4c, and 4d.
As shown in Figure 4, the stability was evaluated in the vertical (X-axis direction) and horizontal (Y-axis direction) directions.
Based on the theory of stability of floating bodies, it is as follows.

(1) From the moment of inertia of the water line area with respect to the Y-Y axis (longitudinal neutral axis) and the volume below the water line of the entire workbench, calculate LBM' (height of the metacenter above the center of buoyancy in the longitudinal direction) in Figure 4b. ) is found, and on the other hand,
From center of gravity height (KG) and center of buoyancy height (KB)
GM′ (vertical metacenter height above the center of gravity) is determined.

The buoyancy tank 1 on the main body is provided for longitudinal stability during levitation rather than for buoyancy.

(2) The GM (lateral metacenter height above the center of gravity) is determined from the same theory as in (1) for the X-X axis (lateral neutral axis).

(3) Stability during levitation is stable even if the center of gravity G is higher than the center of buoyancy B if GM' and GM are positive values.

Next, regarding stability in water during diving descent (same as when ascending from ground level), referring to Figures 5a, 5b, and 5c, as shown in Figure 5c, the center of gravity G is floating. It is necessary that the center of gravity be at a lower position than center B (KB > KG), and in order to maintain a horizontal posture, the center of gravity and the center of buoyancy must be on the same vertical line on the vertical plane, and the weight W' must be The buoyancy force must be greater than B', as shown below.

(4) Full injection of water into the center landing gear tank-1b lowers the center of gravity and reduces reserve buoyancy. (See Figure 5a) In addition, the broken line in the tank 1b in Figure 5a indicates water injection, and the same applies hereinafter.

(5) With only term 4, W′≧B′ (weight > buoyancy) and
If KB>KG does not hold, water is partially poured into the side landing gear water tank-1a as shown in Figure 5b. This effect of lowering the center of gravity is remarkable in the illustrated tank arrangement.

(6) The purpose of the buoyancy tank 1c installed at the top of the side landing gear tank 1a is to raise the center of buoyancy B during diving descent or ascent to stabilize the stance. It will be separated from the water tank to improve safety. The cross-sectional shape does not have to be round or square, but in order to achieve the lightest structure (to raise the center of buoyancy without raising the center of gravity), the example shown is round, and the lower semicircle is the shape of the side leg water tank. It has a structure that also serves as an upper lid. Furthermore, during bottom landing work and walking, explanation will be given with reference to Fig. 6 and Fig. 6a. Fig. 6 shows an example of the worst case in terms of stability of the relationship between the main body and Fig. 6a, and Fig. 6a shows its cross section. The figure shows a state in which the main body's pedestal 4 is in contact with the seabed, and its action is as follows.

(7) After landing on the bottom, fill the side leg water tank-1a with all the water and apply the specified leg load.

(8) If the total weight of the main body and the water weight of the legs is balanced with the buoyancy of the main body (including the buoyancy of the buoyancy tank-1c), then W ₁ in Figure 6a becomes essentially zero,
The fall prevention moment does not change due to frame movement.

(9) In Figure 6a, the total weight of the workbench including the leg water is W ₁ + W ₂ , and the relationship with the buoyant force B' is W ₁ + W ₂ >B'...(i), (W ₁ +W ₂ −B′) is the weight in water,
The column reaction force is determined by this underwater gravity.

The overturning moment due to external force F such as tidal current is F×h
If the main body, the point of action of each underwater weight and the distance between the pillars are l ₁ and l ₂ respectively, then (W ₁ + l ₁ ) + (W ₂ + l ₂ ) > F×h...(ii) holds. is necessary, and the required pillar reaction force R
is determined empirically or experimentally.

In other words, by the static friction coefficient μ R×μ＞F…(iii) It is determined when the

(10) As mentioned in section (8), in the example shown, W ₂・l ₂
is constant and there is little variation in W ₁・l ₁ , so
Stability can be constantly maintained when working or walking. It is desirable that the volume of the side leg water tank-1a satisfies the condition (8) if the required column reaction force R can be obtained by _W2 (underwater load of the main body).

[Effect of idea]

(1) Leg water tanks that can be filled and drained are integrally provided on both sides of at least one of the two main bodies of the underwater walking work platform, and the above-mentioned leg water tanks are installed above each of these leg water tanks. A buoyancy tank separate from the water tank is integrated into the main body as a strength member, so
While maintaining sufficient strength, it is possible to maintain a stable posture during ascent, diving, and landing on the bottom by pouring water into the leg water tank.

(2) There is little variation in stability when working or walking on the seabed.

(3) Paragraph (1) above makes it possible to surface and land on the bottom without the assistance of a crane ship, etc.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the frame structure and tank arrangement of a stable underwater walking work platform as an embodiment of the present invention; Fig. 2 is a view taken along the line L-L' in Fig. 1;
3 is a view taken along the line T-T' in FIG. 1, FIG. 4 is a plan view taken along the water line when the workbench is floating, and FIG. Figure 4b is an explanatory diagram of the vertical stability of the workbench, and Figure 4c is Y-Y in Figure 4.
4d is an explanatory diagram of the lateral stability of the workbench, FIG. 5a is a sectional view showing the submerged state in correspondence with FIG. 4a, and FIG. 5b is a sectional view showing the submerged state in correspondence with FIG. 4c. Figure 5c is an explanatory diagram of the stability of the workbench during diving, Figure 6 is a plan view of the workbench during work and walking, and Figure 6a is an illustration of the stability of the workbench during work and walking. It is an explanatory diagram of sex, and the seventh
Figure 8 shows a conventional underwater walking work platform.
The figure is a side view thereof, and FIG. 8 is an explanatory diagram showing its diving/bottom landing means. ... Main body, -1a ... Side leg water tank,
-1b...Center leg water tank, -1c...Buoyancy tank, -2...Girder, -3...Leg box, -4...
...Pillar, ...Main body, -1 ...Buoyancy tank,
-2...beam, -3...leg box, -4...pedestal,
...X-Y carrier, ...body, ...buoyancy tank, ...crane ship.

Claims (1)

[Scope of utility model registration request] Two bodies that intersect each other at right angles, and these two
A carrier that is attached to the intersection of the two bodies and can drive the two bodies relative to each other in the vertical and horizontal directions, and a carrier that is attached to each of the two bodies to project downward and retract upward. In the underwater walking workbench configured with a water column, the above 2.
Leg water tanks that can be filled and drained are integrally provided on both sides of at least one of the main bodies, and separate compartments from the leg water tanks are provided above the leg water tanks. A stable structured underwater walking work platform, characterized in that a buoyancy tank is integrally installed as a strength member of the main body.