JP2000309914A - Fender - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fender promoting durability of a synthetic resin layer in the rubber fender having the synthetic resin layer with coefficient of friction smaller than rubber on the surface of a head coming into contact with a ship. SOLUTION: A fender has such a structure as the buckling of the head part thereof is not made before the buckling of a part other than the head part is made when the head is brought into contact with a ship. The fender, for example, has a bending point on the surface in a distance equivalent to over 1/6 of the height of the fender from the top thereof, and in a relation between a sectional width B1 parallel to the top surface in the bending point and the top width B, B1 has such a structure as it is less than 1.3 B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fender used as a cushioning material when berthing or mooring a ship or the like.

[0002]

2. Description of the Related Art Fenders are used to absorb shocks and protect the hull of a ship when it berths or moor.
Rubber is widely used as its main constituent material. Further, recently, in order to avoid direct contact between the rubber surface of the rubber fender and the ship, a device for protecting the receiving surface with another material has been devised. Its purpose is to cover the surface of the rubber fender body with a material having a smaller coefficient of friction than rubber, thereby avoiding direct contact between the ship and the fender body, preventing wear of the rubber and extending its life, The purpose is to reduce a frictional shock when a ship comes alongside a shore by interposing a resin layer having a small friction coefficient so that a large pressure is not applied to a bolt fixed to a quay.

For example, Japanese Unexamined Patent Publication No. Hei 5-59711 discloses that the weight average molecular weight of a rubber fender provided on at least a portion in contact with the hull has a weight average molecular weight of 500,000. A fender having the above ultrahigh molecular weight polyethylene layer is disclosed. The purpose is to extend the service life of the rubber fender and improve its wear resistance.

For the same purpose, Japanese Patent Application Laid-Open No. H10-338
Japanese Patent Publication No. 924 discloses a rubber fender with a receiving plate in which a top rigid plastic receiving plate of a fender body that comes into contact with a ship is vulcanized and bonded in a rubber hollow fender. . JP-A-10-338924 discloses a fender in which a receiving surface of a rubber fender body is coated with a polymer blend of a crystalline polyolefin resin and a highly unsaturated diene rubber, whereby the fender is protected. The effect of reducing the friction coefficient on the surface of the pier material and dispersing the compressive force at the time of berthing and reducing the frictional force at the time of mooring is obtained.

[0005]

As described above, the rubber fenders are fixed to the quay, although the purpose of cushioning is achieved to some extent by protecting the receiving surface with other materials. Since the fenders are repeatedly compressed from the berthed or moored ship, their service life is naturally limited. Therefore, any improvement in its durability is always an important issue in this technical field.

Various types of fenders are known. For example, as shown in FIG. 1A, a head having a flat top surface and a divergent part integrated with the head are provided. There is a widespread use of a type having a basic structure including a pair of supporting legs which are opened in a straight line, and the supporting legs are fixed to a quay. This type of fender utilizes the compressive stress and buckling deformation of rubber, and is characterized by a large amount of energy absorption. As described above, it is known to provide a synthetic resin receiving layer on the surface of a portion of the fender that comes into contact with the ship, including at least the top surface of the head.

However, when the conventional fender is compressed at the time of berthing of a ship or the like, as shown in FIG. 1B, the fender buckles at its head and the portion is significantly deformed. When this compression is repeated, the synthetic resin receiving layer adhered to the head gradually deforms plastically, eventually breaking, and eventually breaking down to the rubber fender body. Therefore, an object of the present invention is to prevent the buckling from occurring at the head even when the fender is subjected to compressive deformation, to protect the synthetic resin layer from breaking, and to improve durability more than conventional products. To provide improved fenders.

[0008]

Under the circumstances described above, the present inventors have made various studies and found that a synthetic resin layer having a smaller friction coefficient than rubber is provided on the surface of the head in contact with a ship. In the rubber fender having the above structure, a rubber fender having a head portion that does not buckle before a portion other than the head portion buckles upon contact with a ship has been successfully produced.

That is, the present invention provides: 1) a rubber fender, wherein the head portion does not buckle when it comes into contact with a ship, A fender comprising a synthetic resin layer having a small friction coefficient; 2) at least a surface portion (outer portion) at a distance corresponding to 1/6 or more of the height of the fender from the top of the fender; has a bending point, and in relation to the the bend point definitive top surface parallel to the direction of the cross-sectional width to B ₁ and the top width B, the 1) above, wherein the B ₁ represents that equal to or less than 1.3B 3) The fender according to the above 1), wherein the material of the synthetic resin layer is polyethylene; and 4) The polyethylene is an ultra-high molecular weight polyethylene. It relates to the fender described in the item 3).

[0010] The fender of the present invention is configured so that the head does not buckle even when subjected to compressive deformation, but buckles at other places where the restoring force is high. Even if the synthetic resin layer on the head part is slightly curved, it has a function of easily recovering the original shape when the compressive force is removed. Even if the fender is subjected to compression deformation many times and repeatedly, it is difficult for the synthetic resin layer to break, so that the function of the resin layer is maintained for a long time, and the durability of the rubber body is significantly improved. .

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A fender according to the present invention comprises a flat head and a pair of supporting legs connected in a flared shape to the head, utilizing the compressive stress and buckling deformation of rubber, and The type that absorbs energy is the target. The supporting legs may be independent of each other or may be connected at the bottom.

A typical structural example of the fender according to the present invention will be described with reference to FIG. As shown in this figure, in a fender having a height from the bottom tip of the fender to the top of the head and a width of the top of the head of B, a surface portion extending from the top to the supporting leg. (Outside portion) are provided with bending points A and A ', which are located at a distance corresponding to 1/6 or more of the height H from the top of the synthetic resin layer, and at the top of the bending point. The relation between the cross-sectional width B _{1 in the} direction parallel to the plane and the top width B is at most B ₁
Is 1.3B or less. Here, the synthetic resin layer 16 functions as a receiving layer adhered to a portion that comes into contact with the ship around the head of the rubber fender body 10 and is formed of a resin having a smaller friction coefficient than rubber. I have.

The position of the inflection point needs to be a distance corresponding to 1/6 or more of the height H of the fender from the top of the synthetic resin layer. It becomes difficult to achieve the purpose of avoiding buckling of the resin layer. This installation distance is more preferably 1/5 or more of H, and the maximum installation distance is not particularly limited as long as it buckles at a supporting leg other than the head when compressed and deformed. However, even if the bending point is provided too close to the bottom of the fender, the function intended in the present invention cannot be achieved. In general, it is preferable that the bending point is provided on the surface portion at a position corresponding to not less than 1/6 and not more than 1/4 of the height of the fender from the top of the synthetic resin layer at the head.

The bending point is located outside of the two supporting legs.
And one straight line connecting these two points is parallel to the top surface
In the same direction, that is, at almost the same height
Provided. The cross-sectional width of the fender at the bending point,
That is, the distance B connecting the two points. ₁Is the top parallel to this
Designed to be larger than width B, but at most B₁
= 1.3B, usually B₁<1.2B
Desirably, B₁More preferably, it is <1.1B.
The inner angles at the inflection points A and A 'are usually 70 to 8
It is preferable to set the range to 0 degrees.

The fender according to the present invention has at least the bending points A and A 'specified above in the surface portion (outer portion). On the other hand, a fender of the type that absorbs energy by utilizing the compressive stress and buckling deformation of rubber usually causes buckling deformation at two points when compressed. For example, as shown in FIG. 2a to be described later, buckling also occurs on the back surfaces (inner portions) A ₁ , A ₁ ′ of the supporting legs in a shape corresponding to the bending points A, A ′, and the impact is generated. Be relaxed. In the present invention, in addition to the bending points A and A ', a bending point may be provided in advance on the back surface so that buckling can easily occur.

Next, a state where the fender of the present invention buckles and deforms due to compression will be described with reference to FIG. FIG. 3 (a)
Shows a front external view of the fender before receiving compression. When the head is compressed, it deforms as shown in FIG. At this time, buckling occurs at the inflection points A, A ′ and the inside portions A ₁ , A ₁ ′, thereby absorbing the impact given from the ship. That is, unlike the case of FIG. 1 (b), the fender according to the present invention is configured so that it buckles not at the head to which the synthetic resin layer is bonded but at the supporting leg having a greater restoring force. It is being done.
For this reason, the synthetic resin layer adhered to the head is free from extreme deformation due to buckling even if it may be slightly curved, so that even if repeatedly subjected to compression, plastic deformation and accompanying breakage will occur. Less likely to occur and its original function is maintained for a longer period. The rubber fender body is also protected from destruction, and durability is improved.

The rubber body of the fender of the present invention is manufactured by a conventional method using natural rubber (NR) or synthetic rubber alone or as a blend. As synthetic rubber, styrene-butadiene rubber (S
BR), butyl rubber (BR), chloroprene rubber (C
R), ethylene-propylene terpolymer rubber (EPD)
M) and the like. The rubber composition may contain a compounding agent for rubber which is usually added, such as a filler (eg, a vulcanizing agent, carbon black, silica, clay, etc.), a softening agent. Aging inhibitors, processing aids and the like.

A synthetic resin layer having a smaller coefficient of friction than rubber is bonded to at least a portion of the rubber body that comes into contact with the ship. The synthetic resin layer referred to here is not particularly limited in its material and installation means as long as the purpose is to avoid direct contact between the rubber surface of the rubber fender and the ship and the ship. It can be implemented by appropriately selecting from techniques. For example, the installation means may cover the head with a synthetic resin so as to be integral with the main body, or may attach a synthetic resin plate. The synthetic resin used here has a friction coefficient μ (JIS K 7125) of preferably 0.3 or less, and most preferably 0.2 or less.

As the material of the synthetic resin, a crystalline polyolefin resin is preferable. For example, high density polyethylene (HDPE), ultra high molecular weight polyethylene (UHMWP)
E, μ = 0.2), low density polyethylene (LDPE),
Polyethylene resin such as linear low-density polyethylene (LLDPE), and resin with small friction coefficient μ such as polypropylene (PP), ionomer, metallocene catalyzed polyethylene, metallocene catalyzed polypropylene, ethylene-vinyl acetate copolymer resin (EVA) Specifically, those having a friction coefficient μ of about 0.2 to 0.3 can be preferably used. These crystalline polyolefin resins may be used alone or two or more of them may be blended.

In particular, HDPE or UHMWPE
And the like. Above all, abrasion resistance,
UHMWPE having a weight average molecular weight of 500,000 or more as determined by a viscosity method is preferable because of its high impact resistance and weather resistance.
More than 100,000 is more preferable, and especially 2,000,000-
A range of 3 million is optimal. Next, an example of a method for manufacturing a fender according to the present invention will be described with reference to FIG.

The fender 30 of the present invention is obtained by laying a sheet 32 for forming the synthetic resin layer 16 and a rubber sheet 34 for forming the rubber fender body 10 in a mold 36. It is obtained by vulcanizing with a press vulcanizer 38, cooling, and demolding. Here, as described above, the mold has at least bending points A and A 'on a surface portion at a distance corresponding to 1/6 or more of the height of the fender, from the top of the fender,
And a sectional width B _{1 in a} direction parallel to the top surface at the bending point.
Is designed so as to have a bending point where B ₁ is 1.3 B or less in relation to the top width B.

As the sheet 32 for the synthetic resin layer, an appropriate synthetic resin sheet may be used alone. For example, a synthetic resin and a rubber component (for example, a crystalline polyolefin resin and a diene rubber) may be used based on the friction coefficient of the rubber. The polymer blend mixed at such a ratio that does not become too large is masticated, and further a vulcanizing agent, a vulcanization accelerator and other additives such as carbon black are blended if necessary, kneaded, and then kneaded. A sheet formed into a sheet having a size may be used.

On the other hand, the rubber sheet 34 for the fender body is
The above rubber material is masticated, and a vulcanizing agent, a vulcanization accelerator and other additives such as carbon black, if necessary, are compounded in a composition ratio suitable for a rubber fender, and kneaded. After that, it is obtained by forming into a sheet of an appropriate size for work. When laying a sheet in the mold 36,
First, a sheet 32 for a synthetic resin layer is spread over a portion corresponding to the receiving surface 12 of the fender body 10, and then a rubber sheet 34 for the fender body is spread. Thus, the prototype of the fender 30 is formed in the mold 36. The prototype is press-vulcanized, cooled, and demolded to obtain the fender 30 of the present invention.

According to the above manufacturing method, the fender body 10
And the synthetic resin layer 16 can be integrally formed, and both can be firmly bonded by vulcanization. As the vulcanizing agent used in the production of the fender of the present invention, for example, powder sulfur,
Precipitated sulfur, in addition to sulfur such as insoluble sulfur, for example, alkylphenol-formaldehyde resin, heat-reactive phenol resin, alkyl-phenol-formaldehyde resin,
Resin vulcanizing agents such as brominated alkylphenol-formaldehyde resins can be used.

Various conventionally known vulcanization accelerators can be used. Other additives include, for example, fillers such as carbon black and coloring agents. In addition,
Carbon black may be blended in the polymer blend, but if a large amount of carbon black is blended, the hull in contact with the fender may be stained by the carbon black. From the viewpoint of enhancing the visibility and aesthetics of the fender, various colorants may be blended instead of carbon black.

Although the thickness of the synthetic resin layer 16 is not particularly limited, it is usually preferably 2 mm or more, particularly preferably 5 mm or more, and preferably 10% or less with respect to the thickness of the top and both legs. The installation of the synthetic resin layer may employ a method of fixing a separately prepared synthetic resin plate to the head of the rubber fender body.

The fender according to the present invention further includes, in addition to the above,
Further, a shape as shown in FIG. 5 is also included.

[0028]

The present invention will be described below more specifically with reference to comparative examples and examples. Comparative Example A rubber fender body consisting of a 50:50 weight ratio of natural rubber and styrene rubber (SBR) and its head receiving layer made of ultra-high molecular weight polyethylene (molecular weight by viscosity method; 330 × 1
0 ⁴ , friction coefficient μ according to JIS K 7125;
2) The fender was prepared. This fender (Figure 1a)
Has the following shape, and the rubber body and the receiving layer are vulcanized at 160 ° C. for 10 hours using a mold and adhered.

Total height H of fenders: 1000 mm Thickness of synthetic resin layer T: 10 mm Width of top of fender B: 650 mm Width B _{1 at} position E 200 mm from the top: 950 m
m Bottom width W: 1800 mm When the fender made as described above was compressed by a hydraulic compression tester so as to have a height of 45% of the total height H, the head was seated downward at the center. Succumbed. Thereafter, the compression was released, but the synthetic resin layer was plastically deformed.
After repeating 500 times, the synthetic resin layer was broken.

EXAMPLE A rubber fender body consisting of natural rubber and styrene rubber (SBR) in a weight ratio of 50:50 and its head receiving layer made of ultra-high molecular weight polyethylene (molecular weight by viscosity method: 330 × 1)
0 ⁴ , friction coefficient μ according to JIS K 7125;
2) to prepare a fender having the following shape (FIG. 2a). The rubber body and the receiving layer are separated by 160
The mixture was vulcanized at 10 ° C. for 10 hours and bonded.

Total height H of the fenders: 1000 mm Thickness of the receiving plate T: 10 mm Width of the top of the fender B: 650 mm Width B ₁ : 7 at a position E at a distance of 200 mm from the top
00mm Bottom width W: 1800mm The fender made as described above was used for 52.5% of the total height H.
Fig. 3b
As shown in FIG. 5, the head was slightly bent but did not buckle, but buckled and deformed at the bending point. Thereafter, when the compression was released, the fender returned to its original shape, and the synthetic resin layer became smooth as before. This compression was repeated 3000 times,
The synthetic resin layer did not break, and the fender exhibited good durability.

[0032]

According to the fender of the present invention, when it is subjected to compression from the head, the head does not buckle but buckles at the supporting leg having a high restoring force. Because of this, the synthetic resin receiving layer provided around the head surface of the fender also does not buckle, so that even if compression and release are repeated many times, plastic deformation and accompanying breakage are unlikely to occur. And a longer service life. Thereby, the durability of the rubber fender main body is also significantly improved.

[Brief description of the drawings]

FIG. 1 (a) is a front external view of a conventional fender, before being subjected to compressive deformation. FIG. 2B is a front external view showing a state in which it is compressed.

FIG. 2 is a sectional view showing an example of the fender of the present invention.

FIG. 3 (a) is an example of a fender of the present invention, showing a front external view before compression deformation. FIG.
1 is a front external view showing a state when compressed.

FIG. 4 shows an example of a process for manufacturing the fender of the present invention.

FIG. 5 is a sectional view showing another example of the fender of the present invention.

[Explanation of symbols]

_{A, A ', A 1,} A 1': bending point B: distance between the bend B _1: top width H: the fender height 10: fender body 16: Synthetic resin layer

Claims (4)

[Claims] 1. A rubber fender, wherein the head portion does not buckle when it comes into contact with a ship, and a synthetic resin having a smaller friction coefficient than rubber on the surface of the head that comes into contact with the ship. A fender comprising a layer. 2. A fender having at least a bending point on a surface thereof at a distance corresponding to 1/6 or more of a height of the fender from the top of the fender,
And a sectional width B _{1 in a} direction parallel to the top surface at the bending point.
2. The fender according to claim _1, wherein B ₁ is 1.3 B or less in relation to the top width B. 3. 3. The fender according to claim 1, wherein the synthetic resin layer is made of polyethylene. 4. The fender according to claim 3, wherein said polyethylene is ultra-high molecular weight polyethylene.