JPS60121183A - Anchor structural body - Google Patents

Abstract

PURPOSE:To make a thrust into a seabed part and anchoring force ever so large, by pivoting an anchor shank on a point of gravitational center of an anchor body free of turnover motion, while installing an anchor box projecting an anchor fluke being halved in making this axial center a base point, and forming both upper and lower pressure receiving parts into a sideward incline in section rhombiform. CONSTITUTION:An anchor body 1 is set down to an isosceles triangle as a basis looking from a plane surface, and an anchor fluke 2 is halved with its intervals narrowed, while an anchor box 3 is solidly constituted in one. An anchor shank 5 is pivoted on a gravitional center point 4 of the anchor box 3 free of turnover motion. On the other hand, both upper and lower pressure receiving parts of the anchor box 3 are formed into a sideward incline in section rhombiform. In time of scanning on a seabed surface, owing to these upper and lower pressure receiving parts of the sectional rhombiform anchor box 3 and the anchor shank 5 capable of turnover motion, a sufficient thrust and anchoring force can be secured.

Description

[Detailed Description of the Invention] The present invention is a mooring anchor used for ships, which maintains the horizontal effect of the anchor, which is particularly important, and exhibits strong holding power even when stationary or moving with high stability. This relates to the basic structure of a functional sterless anchor.

It is a known fact that many of the anchors of large ships currently in use move when the holding force exceeds the allowable hold force after being compressed by the sea bed, and eventually lose stability and rotate within the mass M. There is. The reason is that the weight accumulated per 1K of soil increases with depth, and as a result, the soil pressure is more strongly biased towards the tilting claw side when the complex is behaving, and an acting force that suppresses the claw surface on one side is applied, causing the anchor to It is said that a moment of rotation is generated around the trunk, and many modern anchors with wide claw gaps have this problem.

An anchor? /g An anchor that becomes unstable on the floor and moves without being hooked is called dragging anchor, and can cause a ship to be in trouble while anchored in rough weather.
Serious accidents often occur.

Since ancient times, anchors have supported the forces of nature that are applied to the hull of a ship, not only staying in the upper layer of the stratum but also moving while effectively scraping their claws, and acting as a medium to transmit the towing force to the earth, always keeping it level and acting as an active anchor. It is defined as a moving body that does not exert any force on the soil layer.

For the above reasons, the anchor's ability to maintain its grip on the seabed depends on its stability, and at the same time serves as a measure of its performance.

The anchor receives the energy of the given motion as a pulling force,
It functionally returns to and exhausts the earth in its entire range of behavior, from rest to movement.

Traditionally, the basic element of an anchor has been the hook, and the weight effect has been added to 71, and the projected shape of the hook and the angle at which the anchor is attached are also important. This basic fixed anchor has two claws fixed to the anchor trunk and an intersecting anchor culm.

In our country, this is called a cross-shaped anchor. This type, which has been used for thousands of years, is stable with a long anchor, but the effective area of the claws is too small, and the gripping force is inferior to its size, and if the claws were made larger, the raking force would be lower. While being used for a long time with the era of sailing ships, there are also deficiencies in the lack of them.

With the transition to steamships, it was deemed unsuitable for this change, and this was revised.The chevron-shape anchor, which can be seen as an improvement in handling, is now completely accommodated in the anchorage port, through the intermediate crisscross-shape anchor. Develops into an anchor,
This is generally called a stockless anchor car. These are considered to be the main auxiliary anchors for ships, but while they include many types, the most representative JIS type stockless anchors have defects that stem from long customs in their basic structure. The fact that the ship is at risk of dragging anchor is already mentioned in the text of Japanese Patent No. 35022 of 1919. Figure 1 shows this Valles-type anchor, which has a strong slope of 1 bit tilting backwards to the left and right sides of both claws, and the pressure difference due to the depth of the soil layer and the claw corresponding to λ・J. Attitude 11il control is realized using the f0 angle.

However, since this anchor has excellent sex, both claws are parallel to each other,
There was a wide gap in the middle of the claw, and even if horizontal holding was achieved by the difference in soil displacement, the pressing force could not be transmitted to the soil layer, and no increase in gripping force was expected.

Figure 2 shows the patent No. 1127 which eliminates the above defect.
Show No. 762 and narrow the gap between the two claws.

Utilizes the pressing force applied from the vertical direction to the claw surface that tilts backward from side to side, applying force to a wide soil volume, concentrating the acting force on the anchor receiving pressure, increasing the holding force by balancing the displacement difference, and horizontally stabilizing. was secured.

In the present invention, by further developing these, in addition to the conventional elements of anchor construction, the key points are increased grip slope and stability due to the effect of the claw slope, and in addition, soil quality (pressure due to degree) The ratio is closely related to the balance between the area of the anchor claw, which is bisected at the axis of the base of the anchor trunk, which serves as the anchor pressure receiving surface, and the area of the anchor chain. At the same time, it functions at its most suitable depth.As a controlled object, it is capable of extremely active behavior, and this can be defined as a moving body.

Fig. 6 shows this anchor structure obliquely, the complex 1 is basically an isosceles triangle, the anchor claw 2 is divided into parts by narrowing the gap, and the anchor chain 6
are integrated, and the anchor trunk 5 is pivoted at the center of gravity 4 by the rotating shaft B. In the front view A shown in Figure 2, from the tip of the claw to the bottom i,
'+if, the length a at f is equal to the width of the complex. In the side view 13, the left and right sides of the anchor are symmetrical at the neutral line, and the cross-sectional view C shows that the axial center of the complex is configured in a hairstyle along the a-a2 line, and it can be reversed in either direction and maintains the same posture. ,
If the upper surface side of the anchor, which is in a single-acting state in the soil, is the pressure-receiving surface, when the lower surface is raked, the tip, which becomes the lower surface of the claw, digs into the soil and does not hold earth and sand, and is formed on the left and right. Excludes both sides (fill) on the inclined surface, and the claw quickly turns downward, unlike the conventional &
1'l'i removes the defect of the claws slipping on the sea bed due to dirt getting stuck between the two claws, and the effect of narrowing the nine claws is produced (111).

Figure 4A shows a graph in Figure 9B of the change in the pressure difference between points a and b at a constant pressure point L connected vertically by a dotted line within the mass layer until it reaches J-D in the 9th layer, with the vertical axis line P is the pressure, and horizontal axis 1 (is the depth. This upper pressure ratio is large in the upper layer and small in the lower layer, and 2
The pressure is increased while drawing a parabolic line, and soil particles interfere with each other in the deep part.

It is estimated that they support each other with lateral force and diffuse the vertically applied earth pressure.

In Figure 5, we created anchor 1 that models this.

Determine the scale and determine the depth of the fine layer I when the anchor effectively scrapes.
As shown in Figure 6, place the model anchor in a box simulating the soil layer and dry it in a sandy environment with a surface equal to the pressure-receiving surface of this model anchor and equal to the area ratio of both the anchor hook and the anchor chain. Two pressure receiving plates a and 1)
is pulled in the direction of the arrow, and if the forces applied by both are balanced, the test decoration will be stable.

In this case, the upper pressure receiving layer 4 is sandy similar to the soil layer.
The area of Ra is large and b is also small, but the pressure in the lower layer is high and there is a large difference in □h < force between them.In the upper layer, the pressure acts 1) strongly on the plate, and this difference In the lower layer, where the pressure is smaller, the pressure acts on the side of plate A, which has a larger area, and in this experiment, the most effective depth of the anchor and the pressure-receiving surface ratio are set in this middle layer.

The off-line diagram simulates the behavior of the anchor while receiving acting force in the soil layer, with the upper pressure ratio, the anchor claw, the anchor chain receiving pressure, and the anchor shaft supporting shaft set at the center of gravity.

Quality Wt-l: The anchor in part 1 receives a strong force on the claw side while being pulled in the direction of the arrow by a tensile force, and enters in a downward direction. If ≦1゛6 penetrates deeper and reaches the lower layer 2, the pressure difference of 9 cars [111 will decrease and the earth pressure will increase on the lead phase side.
liJJ, the anchor is pulled to one side, and eventually reaches a position where both pressure-receiving surfaces are balanced. The constant rot point 6 is reached.

In this way, the cotton body is able to control its equilibrium behavior under the most appropriate pressure, and by changing the area ratio between the claw and the anchor chain, increasing the claw side makes it deeper, and increasing the lead phase side -j-IL/ In the sandy and other seabed soil layers that have penetrated q and become hard due to the specific gravity of the seabed layer,
The necessary anchoring force can be obtained at a relatively upper layer, and the specific gravity density of the soil and the anchoring force are generally proportional.

The size of the cotton body and the saturation depth of penetration also follow this pattern.

For these two reasons, the anchor is held horizontally by the slope of the claw on the right side of the knob, which will be explained later.The anchor body effect is based on an isosceles triangle that quadruples the soil action force, and the conventional cotton body is In response to the uneven distribution of force in the soil layer, it is balanced with the depth pressure that balances it with the ratio of the partial rare pressure, and as an active body, it achieves perfect performance in all necessary conditions except for the uneven distribution of force. Secured. In order to complete this,
Introducing the pointing performance depending on the size of the cotton body and anchor trunk, and the length of the anchor chain between the anchor and the anchor, which is fI + LI: The size of the holding power due to the ship's position 114' and the water depth ratio, Explain that they are closely related to each other.

Figure 8 V, ships 1 and 6'l' in this sea.
A chain 2 and an anchor 6 are shown, and the depth of the water is H. In experiments, the strongest holding force was obtained when the anchorage length was 6 to 4 times the water depth ratio, that is, H. Normally, the anchor moves horizontally on the seabed, with the anchor chain lying about 70% of the length, and the rest of the length reaches above the water surface with a Katerina curve and continues with the anchor chain 1. At this time, between the anchor and the hull.

It is assumed that there is a directing line 4 as a straight line, and the elevation angle from this cotton body is in the range of 18 to 22 degrees.

The center of pressure on the pressure receiving surface 5 of the anchor in motion does not coincide with this center of gravity point 6, and the towing force is applied to the center of gravity. The average point of pressure is from the apex of the basic triangle of the complex to the center 9 center of gravity between the bases.
This is located on the side and is treated here as the pressure center of the cotton body,
The anchor moves with the points where the earth pressure is most concentrated, and is extended from the base point of the claw plane, and furthermore, via this anchor stem tip 7, the line of orientation immediately reaches the ship in the ocean. ing.

The earth pressure is concentrated on the pressure-receiving surface of the anchor due to the reaction force from the surface of the anchor. The convex-shaped anchor claw of the present invention, which has sides sloping to the left and right, has a stronger compressive concentration effect on soil pressure than any other claw shape to date, and the shape of the anchor claw is much stronger than that seen in Figure 9. A of
In this case, the pressure center point 1 set on the pressure receiving surface of the anchor claw is pressed from both sides by this inclined claw surface because the acting force acts perpendicularly to the claw surface, and the soil is subjected to compressive force in the direction of the arrow.

At the same time, in the center of the claw width, the reaction force from the front and the pressing force of the anchor claw are in balance, and a consolidated part is formed around the butt position of the arrow, and from the side of B, this part is said to be The force is concentrated in the diagonally shaded area located above the tip and slightly below the 6th point, and this focal point becomes the center point.

At this time, there is a compressed part inside the dotted line 4 from the anchor claw tip 2 to the anchor trunk tip 6, and the directional line 5 extending from the focal point is
The anchor, which shows the direction of force through the tip of the anchor trunk, forms a compressed 7t portion between the anchor claw and the anchor trunk due to concentration of force within this soil layer, thereby suppressing the floating of the claw, Arrow a indicates the direction in which the anchor receives horizontal tensile force, and at this time, a 9-dot line is drawn between the soil that is compressed in a direction perpendicular to the claw surface from the tip of the claw to the rear end, and the part where this force does not apply. A shearing force is generated and the anchor claw is held in the direction of the arrow A, but this is absorbed by the force of the arrow C which acts even more strongly and causes the claw to move downward.

The force subtracted from this is the resultant force d with a, which is in the direction of the directional line shown by the arrow. It is estimated that it works as

Therefore, from the argument above, the ratio between the size of the cotton body and the length of the anchor trunk that supports it is important. The distance between A and A is determined to be an appropriate anchor length for the relevant corpuscle, and is closely related to the elevation angle from the seabed of the directional line that affects the holding power of the anchor.

Anchor behavior Always keep a straight line from above and anchor from the focal point, which is the center of pressure! If the complex is tilted, the tip of the anchor stem will deviate from this tM, h.

The towing force acts between the ship and the focal point of motion, transmitting the force through the tip and creating a pinning action on the anchor trunk to keep the hull in place.

Figure 10 shows the acting force that restores the complex to horizontal when it is tilted in the soil. The force in the direction becomes large, and on the b-plane, on the contrary, the force acting from the perpendicular direction becomes small.As a result, the 8 planes are pushed back, and the complex always moves horizontally.Figure 13 ij cross-sectional view.

, and the size of the anchor provided on the ship mentioned in the text.

Depends on the effective anchor chain length to water depth ratio. This consideration of the weight eliminates excessive stress on the hull and improves stability and holding power through the effect of the tilting claw surface.

Furthermore, the activeness of the anchor can be adjusted freely by balancing the ratio of the tosho and the pressure-receiving surface of the pot, which solves the conventional doubts about the anchor's active property.

If you can obtain effective mooring force when anchoring in rough weather with the original function, let out excess anchor chain and prevent accidents due to breakage or entanglement, and do not rely only on the weight effect of the anchor chain, but emphasize the material strength, The safety of anchoring ships in the limited mooring waters of today's ports has been greatly improved, making narrow ports more effective.

If the anchor does not rotate on the seabed and its claws are constantly scratching the soil, is it a waste of wind? Without the ship moving in the +fI style, with the existence of a pointing line that can be estimated and suggested, and based on this logic, with effective anchoring techniques using the anchor and anchor chain, it is possible to deal with anchor dragging and the ship's turning.

The present invention breaks away from the traditional concept of anchors and proposes them as nine functional bodies, describes various elements related to the relationship between anchors and seabed soil, and achieves horizontal stability by self-functioning without using anchor height. The restoration is based on the two culvertless anchors introduced at the beginning, which realize each direction. It has grown through a long history of change and is backed by experience and results. The most basic of practical stable anchors with high holding power is the sterless anchor for ships. We presented and explained the development technology for adult anchor qlrt.

[Brief explanation of the drawing]

Figures 1 and 2 are perspective views of the sterless anchor cited in the main text. FIG. 6 is a perspective explanatory view of an anchor structure according to the present invention. Fourth
The figure shows the soil pressure σ) rate of change! is an explanatory diagram, and B is this graph. Fig. 5 explains the relationship between the anchor and the depth of the model anchor, and Fig. 6 shows the relationship between the anchor and the depth of the model in the soil layer. The off-diagram explains the behavior of /, , ¥ in the soil layer and its balancing effect. Figure 8 shows a ship, anchor chain, and anchor. The relationship between the directional lines related to this will be described, and FIG. 9 will further explain the relationship between this complex and the anchor trunk. Figure 10 shows A due to the slope effect of the anchor claw, and Figure 13 shows this restoration and horizontal stability. Figure 4 A B Figure 5 Figure 6 Figure 7 ← 1

Claims (1)

[Scope of Claims] An anchor trunk is pivotably mounted at the center of gravity of the complex, and an anchor box and an anchor claw bisected are provided with the center of gravity of the complex as a base point, and the anchor trunk is bisected perpendicularly from the complex at the center of the axis. with the anchor claw side. The area ratio of both pressure-receiving surfaces on the anchor box side and the dosing ratio applied to one side as the anchor approaches in a normal attitude are balanced as follows, and the anchor is balanced at a certain depth and the anchor moves automatically with the dosing force acting on the main body. An anchor structure that is characterized by a control function that aims at the most effective depth from the bottom, always maintains stable force and posture, and behaves on the bottom sediment.