JP2001172939A - Fender - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel fender capable of bringing a strain-reaction characteristic curve within an allowable distortion rate to an ideal shape as much as possible. SOLUTION: A step 14 projectings the outer peripheral face of a second support part 12 one step outward from the outer peripheral face of a first supporting part 11 is provided at the outer peripheral face of the boundary between the cylindrical first support part 11 and a hollow conical second support part 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a fender.

[0002]

2. Description of the Related Art As a so-called fender 9 for protecting the hull of a ship by absorbing energy at the time of berthing to a quay or the like and mitigating an impact, FIG. Although not shown in the drawing, a receiving member such as a receiving plate is attached to the tip of the first supporting portion 91 having a constant outer diameter and a constant thickness. A hollow cone-shaped second support portion 92 having a constant thickness and extending in a tapered shape from the base end side of the collision portion toward the mounting surface Q such as a quay wall.
And a so-called circle type formed integrally with an elastic material such as rubber are widely used.

[0003] When receiving the compressive force due to the berthing of a ship, the circle type fender 9 first generates a reaction force against the compressive force, and generates a first support portion 91 and a second support portion 92. The bending starts at a boundary portion between the first and second support portions 92 and at a substantially central position in the height direction, and finally buckles at a stage where it cannot finally resist the compressive force. Next, as shown in FIG. 8 (b), the whole is deformed until it is folded almost without any gap, and then further compressed into a single rubber mass.

[0004] This process is represented by a distortion-reaction characteristic curve showing the amount of distortion of the fender 9 due to compression and the reaction force generated in the fender 9 at that time, and the result is shown in FIG. 9. That is, FIG.
From the normal state of (a) until immediately before the bent portion buckles,
In FIG. 9, it corresponds from the origin O to the maximum point A. During this time, the bent fender 9 generates a reaction force to return to the original position by receiving the compressive force, and therefore the reaction force increases.

However, when the fender 9 buckles, the above-mentioned reaction force is almost lost, so that the fender 9 is crushed as a whole until the folded state shown in FIG. Reaction force decreases. That is, the course from the maximum point A to the minimum point C is traced. Then, when the state of FIG. 8B is reached, the entire fender 9 behaves as one rubber mass as described above and again generates a large reaction force. The reaction force unilaterally increases via the point B.

[0006]

Generally, the range in which the fender having such a characteristic curve can be actually used is the same as that of the maximum point A since the reaction force starts to increase again from the point O from the point C. The amount of distortion up to point B indicating the reaction force value is restricted to a range from the origin O to the amount of distortion D in terms of the amount of distortion. This is because, after the distortion amount D, the reaction force becomes too high, which may cause a problem such as damaging the hull.

[0007] The above-mentioned fender has an allowable distortion D
The amount of energy that can be absorbed within the range is the amount corresponding to the area S ₁ of the region divided by the above characteristic curve, the horizontal axis passing through the origin O, and the vertical axis passing through the point B. Fender is in the area S _1, a characteristic curve can absorb the energy of an amount corresponding to a partial addition of the horizontal axis and the area S ₂ region divided by connecting the points A-B Ideally is a basis, in practice only the area S ₂ minutes, the amount of energy that can be absorbed is reduced, the efficiency of energy absorption is lowered.

Therefore, the distortion-reaction characteristic curve of the fender is
Ideally, the portion after the maximum point A is as horizontal as possible, that is, the reaction force after the maximum point A shows a value almost constant. SUMMARY OF THE INVENTION An object of the present invention is to provide a novel fender capable of making a strain-reaction characteristic curve within an allowable strain range as close to an ideal shape as possible.

[0009]

Means for Solving the Problems and Effects of the Invention In order to solve the above problems, the inventors studied various cross-sectional shapes of a circle-shaped fender. As a result, in the conventional fender 9 shown in FIG. 8A, the outer peripheral surface of the boundary portion between the first supporting portion 91 and the second supporting portion 92 was neatly continuous. When the cross-sectional shape is adjusted so that a step is provided so that the outer peripheral surface of the two supporting portions 92 protrudes outward by one step from the outer peripheral surface of the first supporting portion 91, the drop of the reaction force after the maximum point A is suppressed. , While making the characteristic curve as close as possible to the ideal form, and increasing the amount of energy that the fender can absorb,
It has been found that the efficiency of energy absorption can be improved.

That is, the fender of the present invention comprises a cylindrical first supporting portion having a constant outer diameter to which a receiving member is attached at the tip, and a quay or the like from the base end side of the first supporting portion. A hollow cone-shaped second support portion expanding in a tapered shape toward the mounting surface is integrally formed of an elastic material, and is formed on an outer peripheral surface of a boundary portion between the first support portion and the second support portion. A step is provided so that the outer peripheral surface of the second support portion projects one step outward from the outer peripheral surface of the first support portion.

FIG. 8 (a) shows a conventional double support portion 91,
Fender 9 with a beautifully continuous outer peripheral surface at the boundary of 92
In the bending, a gap C is formed at the bent portion of the both supporting portions 91 and 92, and the gap C causes a decrease in the reaction force at the maximum point A and a buckling after the maximum point A. The drop in the reaction force afterwards increases. On the other hand, for example, FIG.
As shown in the figure, the outer peripheral surface of the second support portion 12 is one step outward from the outer peripheral surface of the first support portion 11 on the outer peripheral surface at the boundary between the first support portion 11 and the second support portion 12. Step 14 to project to
In the fender 1 of the present invention provided with, the gap generated in the bent portion can be reduced or eliminated altogether, so that the reaction force at the maximum point A can be improved, and Of the reaction force can be suppressed.

In the conventional fender 9, after the buckling, the timing at which the outer peripheral surfaces of the two supporting portions 91 and 92 come into contact with each other is early. The amount of distortion D until reaching the point B indicating the force value decreases. On the other hand, in the fender according to the present invention, after the buckling, the timing at which the outer peripheral surfaces of the two supporting portions come into contact with each other can be delayed, so that the reaction force starts to increase, and the maximum point A is reached. It is possible to increase the amount of distortion D until reaching the point B showing the same reaction force value.

Therefore, according to the fender of the present invention, due to the synergistic effect, the characteristic curve can be made as close as possible to the ideal shape, the amount of energy that can be absorbed by the fender can be increased, and the efficiency of energy absorption can be improved. It is possible to do.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A fender according to the present invention will be described below with reference to FIGS. As shown in these figures, the fender 1 of this example is not shown, but a receiving member such as a receiving plate is attached to the tip thereof, and a cylindrical first support having a constant outer diameter and thickness is provided. A second support portion 12 having a constant thickness and a hollow cone shape, which extends in a tapered shape from a base end side of the first support portion 11 toward a mounting surface Q such as a quay; The mounting surface Q extending outward from the most widened base end of the support portion 12.
And a flange 13 having a circular flange shape, which serves as a mounting portion, is integrally formed of an elastic material such as rubber.

In the present invention, the outer peripheral surface of the second support portion 12 is attached to the outer peripheral surface of the boundary portion between the first support portion 11 and the second support portion 12 among the above-mentioned portions. A step 14 is provided so as to protrude outward by one step from the outer peripheral surface of. Step 1
Although the size of the support 4 is not particularly limited, when the inner peripheral surfaces of the boundary portions of the support 11 and 12 are made to be clean and continuous as shown in the example of the figure, the thickness T _{1 of the} support 11 and 12 is large. , can be by the ratio of T _2, it defines the size of the step 14.
Specifically, the size of the step 14 is set so that the thickness T ₁ of the first support portion 11 is 0.8 to 0.9 times the thickness T ₂ of the second support portion 12. Is preferred.

If the thickness T ₁ of the first supporting portion 11 is less than the above range, the step 14 becomes too large, and the thickness of the second supporting portion 12 becomes relatively too large. Since the timing at which the inner peripheral surfaces of the upper and lower portions of the second support portion 12 that are bent at substantially the center position in the height direction come into contact with each other earlier is increased, the reaction force starts increasing and the same as the maximum point A There is a possibility that the problem that the amount of distortion D until reaching the point B indicating the reaction force value becomes small may occur.

Conversely, if the thickness T ₁ of the first support portion 11 exceeds the above range, the size of the step 14 cannot be sufficiently obtained, so that the bending The effect of improving the reaction force at the maximum point A and suppressing the drop of the reaction force after the maximum point A, or after buckling, By delaying the timing at which the outer peripheral surfaces of the eleventh and twelve come into contact with each other, the reaction force starts to increase and the effect of increasing the amount of distortion D until reaching the point B showing the same reaction force value as the maximum point A can be obtained. There is a possibility that the problem that there is not.

In consideration of these characteristics, it is preferable that the thickness T ₁ of the first supporting portion 11 is smaller within the above range, that is, as close to 0.8 times the thickness T ₂ of the second supporting portion 12 as possible. . In the figures, reference numerals 13a ... are through holes formed in the flange 13 for inserting bolts (not shown) for fixing the fender 1 to the mounting surface Q and the like. Although not shown, a rigid member for reinforcement such as a steel plate may be embedded in the flange 13. Also the first
A rigid member for reinforcement, such as a steel plate, is buried at the tip (the upper end in the figure) of the support portion 11 for reinforcement and for attaching a receiving member such as a receiving plate. You may.

Although the shape and dimensions of the fender 1 of the present invention other than those described above are not particularly limited, the height H ₁ of the first supporting portion 11 is the sum of the heights of the both supporting portions 11 and 12. the value is preferably 0.1 to 0.3 times the total height H _0. The angle θ ₁ of the taper of the second support portion 12 to the mounting surface Q is preferably 70 to 80 °. The height H ₁ and the angle θ ₁ are such that the overall height H ₀ is constant and the outer diameter D of the flange 13 that defines the mounting area on the mounting surface Q.
_{If 2} is constant, it indicates a correlation. That is, FIG.
As shown in FIG. 5, as the ratio of the height H ₁ of the first support 11 to the total height H ₀ increases, the second support 12 becomes larger.
Angle theta ₁ is small, the angle theta ₁ of the second支衝portion 12 as the ratio of the height H ₁ is reduced conversely increases.

When the height H ₁ of the first support 11 is less than the above range or the angle θ ₁ exceeds the above range, the second support 12 occupies relatively. Since the ratio increases, the reaction force at the time of bending and buckling increases, and the timing at which the second support portion 12 starts bending, the timing at which it buckles, and the timing at which it no longer buckles, are delayed. Although the absorbed energy increases, the constant load region carried by the first support portion 11, that is, the region where the reaction force is substantially constant from the maximum point A to the point B in the characteristic curve is small due to the characteristic. It may become too suitable to be used as a fender.

Conversely, if the height H ₁ of the first support portion 11 exceeds the above range or the angle θ ₁ is less than the above range, the second support portion 11 will relatively move. Since the ratio occupied by the second support portion 12 becomes small, the reaction force at the time of bending and buckling becomes small, and the timing at which the second support portion 12 starts bending, the timing at which it buckles, and the timing at which it no longer buckles is advanced. Therefore, the absorbed energy as a whole tends to decrease.

In consideration of the balance of these characteristics, the height H ₁ of the first support 11 is equal to the height H ₀ of the entire height H 0.
More preferably, it is about 25 times, and the angle θ ₁ of the taper of the second support portion 12 is more preferably about 72.5 °. Fender 1 of this example composed of the above parts
For example, an unvulcanized rubber compound and, if necessary, a plate-shaped rigid member embedded in the tip end of the first support portion 11 or the flange 13 are formed into a mold corresponding to the shape of the fender 1. It is manufactured by vulcanizing the rubber by charging it inside, heating and pressing.

The configuration of the fender according to the present invention is not limited to the example shown in the drawings described above, and various design changes can be made without changing the gist of the present invention.

[0024]

The present invention will be described below based on examples and comparative examples. Example 1 Rubber compound using a mixed rubber of natural rubber and butadiene rubber at a weight ratio of 6: 4 as a base rubber, and a thickness of 28 m
m, one circular flange-shaped steel plate having an outer diameter of 650 mm and an inner diameter of 270 mm (a rigid member embedded at the tip of the first support portion 11)
And thickness 28mm, outer diameter 1470mm, inner diameter 710mm
A single circular flange-shaped steel plate (a rigid member embedded in the flange 13) is charged into a mold and heated and pressed to vulcanize the base rubber, thereby obtaining the cross-sectional shape shown in FIG. A circular fender 1 having the following dimensions and angles was manufactured. <Dimensions and Angles> Thickness T ₁ of first supporting portion 11 = 220 mm Thickness T ₂ of second supporting portion 12 = 244 mm Ratio of thickness T ₁ / T ₂ = 0.9 Height of first supporting portion 11 H ₁ = 250 mm Overall height H ₀ = 1000 mm Height ratio H ₁ / H ₀ = 0.25 Angle θ ₁ of second support section 12 = 72.5 ° Outer diameter D of first support section 11 ₁ = 680 mm Outer diameter D _{2 of} flange 13 = 1500 mm Example 2 Same rubber compound as used in Example 1 above,
A circular fender 1 having the cross-sectional shape shown in FIG. 3A and having the following dimensions and angles was manufactured using two circular flange-shaped steel plates. <Dimensions and Angles> Thickness T ₁ of first support portion 11 = 220 mm Thickness T ₂ of second support portion 12 = 275 mm Ratio of thickness T ₁ / T ₂ = 0.8 Height of first support portion 11 H ₁ = 250 mm Overall height H ₀ = 1000 mm Height ratio H ₁ / H ₀ = 0.25 Angle θ ₁ of second support section 12 = 72.5 ° Outer diameter D of first support section 11 ₁ = 680 mm Outer diameter D _{2 of} flange 13 = 1500 mm Example 3 Same rubber compound as used in Example 1 above,
A circular fender 1 having the cross-sectional shape shown in FIG. 4A and each part having the following dimensions and angles was manufactured using two circular flange-shaped steel plates. <Dimensions and Angles> Thickness T ₁ of first supporting portion 11 = 220 mm Thickness T ₂ of second supporting portion 12 = 244 mm Ratio of thickness T ₁ / T ₂ = 0.9 Height of first supporting portion 11 H ₁ = 300 mm Overall height H ₀ = 1000 mm Height ratio H ₁ / H ₀ = 0.30 Angle θ ₁ of second support section 12 = 70.0 ° Outer diameter D of first support section 11 ₁ = 680 mm Outer diameter D _{2 of} flange 13 = 1500 mm Example 4 Same rubber compound as used in Example 1 above,
A circular fender 1 having a cross-sectional shape shown in FIG. 5A and each part having the following dimensions and angles was manufactured using two circular flange-shaped steel plates. <Dimensions and Angles> Thickness T ₁ of first supporting portion 11 = 220 mm Thickness T ₂ of second supporting portion 12 = 244 mm Ratio of thickness T ₁ / T ₂ = 0.9 Height of first supporting portion 11 H ₁ = 100 mm Overall height H ₀ = 1000 mm Height ratio H ₁ / H ₀ = 0.10 Angle θ ₁ of second support section 12 = 80.0 ° Outer diameter D of first support section 11 ₁ = 680 mm Outer diameter D _{2 of} flange 13 = 1500 mm Comparative Example 1 Same rubber compound as used in Example 1 above
A circular fender 9 having the conventional cross-sectional shape shown in FIG. 8A and each part having the following dimensions and angles was manufactured using two circular flange-shaped steel plates. In addition, as a steel plate embedded at the tip of the first support portion 91, a thickness of 28 mm,
Those having an outer diameter of 670 mm and an inner diameter of 270 mm were used. <Dimensions and Angles> Thickness T ₁ of first support portion 91 = 230 mm Thickness T ₂ of second support portion 92 = 230 mm Thickness ratio T ₁ / T ₂ = 1.0 Height of first support portion 91 H ₁ = 250 mm Overall height H ₀ = 1000 mm Height ratio H ₁ / H ₀ = 0.25 Angle θ ₁ of second support portion 92 = 72.5 ° Outer diameter D of first support portion 91 ₁ = 700 mm Outer diameter D _{2 of} flange 93 = 1500 mm Comparative Example 2 Same rubber compound as used in Example 1 above
A circular fender 7 having the cross-sectional shape shown in FIG. 6A and each part having the following dimensions and angles was manufactured using a circular flange-shaped steel plate. The steel plate buried at the tip of the first supporting portion 71 has a thickness of 28 mm and an outer diameter of 690.
mm and an inner diameter of 270 mm were used. <Dimensions and Angles> Thickness T ₁₁ of the tip end side (upper end side in the figure) of the first support part 71
240 mm Thickness T ₁₂ = 216 on the base end side (lower end side) of the first support portion 71
mm Thickness T ₂ of the second support portion 72 = 240 mm Ratio T ₁₁ / T ₂ = 1.0 of thickness T ₁₂ / T ₂ = 0.9 Height H ₁ of the first support portion 71 = 250 mm Overall height H ₀ = 1000 mm Height ratio H ₁ / H ₀ = 0.25 Angle θ ₁ of second support portion 72 = 72.5 ° Outer diameter D ₁ of first support portion 71 = 720 mm Flange outer diameter D ₂ = 1500 mm above embodiments of 73, the major dimension of the fender of the comparative example are summarized in Table 1.

[0025]

[Table 1]

Compression test The fender of each of the above embodiments and the comparative example was attached to the tip of the first supporting portion by a spacer simulating a receiving plate, having the same diameter as the first supporting portion and having a thickness of 200 mm. Was attached to the head of a 500-ton hydraulic press, and compression (compression ratio) -reaction characteristics when compressed were measured. The compression ratio was determined by the following equation. Compression ratio _{(%) = (H 0 -H} 0 ') / H 0 × 100 [However H ₀ is the total of the initial shape height, H _0' is the height of the whole in a compressed state. The results are shown in FIG.

[0027] From the figure, the conventional example, the first and the thickness T ₁ of the支衝portion 91, fender 9 of Comparative Example 1 without a step to equal the thickness T ₂ of the second支衝92 It was found that, when bending, the reaction force at the maximum point A decreased, and the drop of the reaction force after buckling after the maximum point A increased. Then, when the cross-sectional shape in the bent state was examined, it was confirmed that a large gap C was formed in the bent portions of both the support portions 91 and 92 as shown in FIG. 8B.

The fender 9 of Comparative Example 1 is shown in FIG.
After buckling, as shown in FIG.
Since the contact timing of 1a and 92a is early, the reaction force starts to increase and the compression ratio corresponding to the distortion amount D until reaching point B showing the same reaction force value as the maximum point A is as small as 60%. Was also confirmed. The first支衝portion 71, the outer peripheral surface thereof, with (in the figure the lower end side) the base end side extends toward the distally (upper side) tapered, the thickness T ₁₁ of the leading end side, fender 7 of Comparative example 2 and minutes only the proximal side of the thickness T ₁₂ is greater than the cross-sectional shape of the taper at the bent state as shown in FIG. 6 (b), the bent portions of the支衝portions 71 and 72 Since the gap C is not generated, the drop of the reaction force after buckling is small, but the timing at which the outer peripheral surfaces 71a and 72a of the both support portions 71 and 72 come into contact after buckling is early.
It was also confirmed that the compression ratio corresponding to the amount of distortion D until the reaction force started to increase and reached the point B showing the same reaction force value as the maximum point A was as small as 58%.

On the other hand, all the fenders 1 of Examples 1 to 4 are bent in the bent state as shown in FIGS. 2 (b) to 5 (b). Since no void C is formed in the buckle, it was confirmed that the drop of the reaction force after buckling was small. In addition, the fenders of the respective embodiments are all buckled, and the upper and lower portions of the outer peripheral surfaces of the two support portions 11 and 12 and the second support portion 12 which are bent substantially at the center in the height direction. Because the timing at which the inner peripheral surfaces of the contact points come into contact with each other can be delayed as compared with Comparative Examples 1 to 3, the amount of distortion before the reaction force starts to increase and reaches the point B showing the same reaction force value as the maximum point A It was also confirmed that the compression ratio corresponding to D can be increased to about 62 to 67%.

In each of the embodiments, both the support units 11 and 12
Thickness ratio T₁/ T_TwoExample 1 and Example 2 differing only in
Therefore, the smaller the above ratio, the smaller the absorption energy
Energy can be increased. Further, the above ratio T₁
/ T_TwoAre the same, and the ratio H of the height of the first support 11 is₁/ H
₀And the angle θ of the second support portion 12₁Examples 1 and 3 differing from
And 4, the ratio H₁/ H ₀Is large and the angle
θ₁Is smaller, the overall absorbed energy decreases
And the ratio H₁/ H₀Is small and the angle θ
₁Is larger, the constant load area carried by the first support 11 is smaller.
It was confirmed that it had a tendency to decrease.

[Brief description of the drawings]

FIG. 1 (a) is a longitudinal sectional view showing an example of an embodiment of a fender of the present invention, and FIG. 1 (b) is a partially cutaway perspective view of the fender of the above example. FIG.

FIG. 2 (a) is a longitudinal sectional view showing a cross-sectional shape of the fender according to the first embodiment of the present invention in a normal state without compression, and FIG. 2 (b) is a longitudinal sectional view of the first embodiment. It is a longitudinal cross-sectional view which expands and shows the state which compressed and bent the fender.

FIG. 3 (a) is a longitudinal sectional view showing a cross-sectional shape of a fender according to a second embodiment of the present invention in a normal state without compression, and FIG. 3 (b) is a longitudinal sectional view of the second embodiment. It is a longitudinal cross-sectional view which expands and shows the state which compressed and bent the fender.

FIG. 4A is a longitudinal sectional view showing a cross-sectional shape of a fender according to a third embodiment of the present invention in an uncompressed normal state; FIG. 4B is a longitudinal sectional view of the third embodiment; It is a longitudinal cross-sectional view which expands and shows the state which compressed and bent the fender.

FIG. 5A is a longitudinal sectional view showing a cross-sectional shape of a fender according to a fourth embodiment of the present invention in an uncompressed normal state, and FIG. 5B is a longitudinal sectional view of the fourth embodiment. It is a longitudinal cross-sectional view which expands and shows the state which compressed and bent the fender.

FIG. 6 (a) is a longitudinal sectional view showing a cross-sectional shape of the fender of Comparative Example 2 in a normal state without compression, and FIG. 6 (b).
FIG. 4 is an enlarged longitudinal sectional view showing a state in which the fender of Comparative Example 2 is compressed and bent.

FIG. 7 is a view illustrating a fender of each embodiment and a comparative example of the present invention.
It is a graph which shows the amount of distortion (compression rate)-reaction force characteristic.

FIG. 8 (a) is a longitudinal sectional view showing a cross-sectional shape of a fender of Comparative Example 1 which is a conventional example in an uncompressed normal state, and FIG. 8 (b) is a longitudinal sectional view of Comparative Example 1; FIG. 4 is an enlarged longitudinal sectional view showing a state in which the fender is compressed and bent.

FIG. 9 is a graph illustrating the relationship between the amount of strain and the reaction force of a conventional fender and the amount of energy absorbed therefrom.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fender 11 First support part 12 Second support part 14 Step Q Mounting surface (quay, etc.)

Claims (1)

[Claims] 1. A cylindrical first supporting portion having a constant outer diameter, to which a receiving member is attached at a distal end, and a tapered shape from a base end side of the first supporting portion to a mounting surface such as a quay. And a hollow conical second support portion formed integrally with an elastic material. The outer peripheral surface of the boundary between the first support portion and the second support portion is provided with a second support portion. A fender, wherein a step is provided so that an outer peripheral surface protrudes one step outward from an outer peripheral surface of the first support portion.