JP2655280B2 - Seal material for air cushion boat - Google Patents

Description

The present invention relates to a sealing material for an air cushion boat, and more particularly to a sealing material for an air cushion boat having improved durability.

[Conventional technology]

2. Description of the Related Art Generally, an air cushion boat sails by feeding air into an air chamber provided between a lower part of the hull and the water surface to float the boat. In order to obtain this buoyancy, the air chamber is formed of a sealing material made of rubber cloth or the like so as to maintain the air in the air chamber at the lower part of the hull at a constant pressure.

The sealing material is usually called a skirt material in the case of a hovercraft having an amphibious function, and is called a sealing material in a case of a side wall type air cushion boat (SES).

Conventionally, as materials for skirts or seals of air cushion boats such as the above-mentioned Hovercraft and SES (hereinafter collectively referred to as seal materials), woven fabrics made of synthetic fibers such as polyamide (nylon), aramid (aromatic polyamide), and polyester have been used. A rubberized cloth coated with natural rubber (NR) or synthetic rubber after being subjected to an adhesive treatment is used.

Synthetic rubbers include polychloroprene (CR), acrylonitrile-butadiene copolymer (NBR) and blends thereof, polyurethane (PU), polyoxypropylene (OPR), ethylene-propylene copolymer (EPDM), chloro Sulfonated polyethylene (CSM),
Butyl rubber (IIR), a blend of polyvinyl chloride (PVC) and NBR, and a blend of polybutadiene (BR) and NR have been used.

In the following description, natural rubber, synthetic rubber, and various blended rubbers are collectively referred to as an elastomer.

[Problems to be solved by the invention]

The seal material that holds the air pressure forms part of the boat,
Absorb the shock applied to the boat by the flexibility of the sealing material,
Since it protects the hull itself, the vibration applied to the sealing material due to the synergistic action of the boat's traveling speed and the waves on the water surface is very severe, and the fatigue of the sealing material due to this is even more severe. Therefore, since the sealing material up to the present time causes a deterioration phenomenon in a relatively short time, a long-lasting material having further excellent durability is demanded from the viewpoint of a boat's operation purpose, profitability and the like.

Factors governing the life of the sealing material are a composite of the fiber structure of the woven fabric constituting the sealing material or the skirt material, the elastic modulus of the elastomer and the permeability of the elastomer to the woven fabric, the adhesion between the woven fabric and the elastomer, and the like. If the specific factors are missing, the overall balance will be lost, resulting in a short life as a sealing material.

When the actual breakage of the seal material is a phenomenon such as peeling of the elastomer and the woven fabric, fraying of the woven fabric, tearing of the woven fabric, or tearing, etc. Until now, the focus has been on the bonding between woven fabrics and elastomers, the fiber structure and mechanical properties of woven fabrics, and little has been said about the physical properties of elastomers alone. In particular, the physical properties related to the vibration phenomenon of the elastomer coated on the woven fabric seem to have a considerable effect on the life of the sealing material.

[Object of the invention]

The present invention has been conceived in consideration of the conventional problems, and clarifies the role of the physical properties of the elastomer in the life of the sealing material, and extends the life of the elastomer by far. To provide a sealing material for air cushion boats.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a seal material for an air cushion boat, wherein the elastomer has a JIS hardness of 70 to 90 and is coated on a woven fabric.

[Function of the invention]

The present invention is configured as described above, and a rubber-coated cloth coated with a coated rubber having a JIS hardness of 70 to 90 has a significantly longer life than the conventional one.

In a rubberized cloth vibrating due to the action of some external force, part of the energy given to this is converted to heat generated in direct proportion to the loss coefficient tanδ of the elastomer, but on the other hand, stress and deformation Is higher as the hardness is higher. Therefore, it is considered that the long life when an elastomer having high hardness is used can be explained by the fact that deformation is less likely to occur than heat generation. This is clear from the fact that, in the WJF test described in detail later, it is visually observed that the higher the hardness of the elastomer, the less likely it is that vibration due to jet water occurs.

Hereinafter, the configuration of the present invention will be described in detail with reference to the drawings.

1 and 2 are model perspective views including a cross section of a rubberized cloth of the sealing material for an air cushion boat according to the present invention. FIG. 1 is a model diagram of a plain weave, and FIG. FIG. 1 shows a case where warp and weft single yarns 2 of a woven fabric are densely woven, and FIG. 1 shows a case where each single yarn is roughly woven. The periphery of the single yarn 2 is covered with an elastomer (rubber) 1.

Here, in FIG. 1, the elastomer 1 covering the woven fabric passes through the gap between the single yarns 2 of the woven fabric and communicates with the upper surface and the lower surface. On the other hand, in FIG. 2, since the woven fabric is densely woven, the woven fabric itself is in the form of a single plate, and the elastomer layer is bonded to the upper and lower surfaces of the woven fabric one by one. Become. In any case, as the elastic modulus of the elastomer is larger, the upper and lower surfaces are stretched through the woven cloth, and the rubberized cloth itself is hard to bend. Since the elastic modulus of an elastomer is a relationship between stress and deformation (strain), JIS hardness is equivalent to a physical property that can be replaced with a simpler measuring instrument.

In the present invention, the JIS hardness of the elastomer is 70 to 9
The range is 0. JIS for commonly used elastomers
The hardness is 50 to 70, but when the JIS hardness of the elastomer becomes 70 or less, the elastomer easily follows external stress and is forcibly deformed. Conversely, if it exceeds 90, the tensile strength is increased, but on the other hand, the elongation is remarkably reduced, and the original physical properties of the elastomer are lost. On the contrary, excessive external stress causes breakage such as cracks. In addition, in the production process, it is not preferable because troubles such as burning and poor adhesion are caused by heat generation in the mixing, rolling and molding of the elastomer. When the JIS hardness is between 70 and 90, there is no such problem, and the Mooney viscosity of the unvulcanized elastomer is relatively high. If processing such as impregnating and drying the woven fabric in advance with the dissolved rubber paste,
Process trouble during rolling can be eliminated.

The yarn 2 includes cotton, rayon and polyamide,
Polyester, polyethylene, polypropylene, formalized polyvinyl alcohol, polyacrylonitrile aramid, synthetic fibers such as silicon carbide fibers, inorganic fibers and metal fibers such as steel and stainless steel, and wires are used.

As the elastomer 1, NR, CR, PU, OPR, EPDM, CS
M, IIR, PVC, BR, isoprene (IR), styrene-butadiene copolymer (SBR), polysulfide rubber (TR), chlorinated polyethylene (CPE), olefin rubber (AL), epichlorohydrin rubber (ECO), Silicone rubber (Si), fluorine rubber (FR), or a blend of a plurality of elastomers is used.

Needless to say, among general synthetic resins, an epoxy resin containing a speran ring, which is a resin having relatively high elasticity, that is, an elastic epoxy resin is also included.

As a method for easily and quickly knowing the vibration fatigue life of the sealing material for an air cushion boat obtained in this manner, that is, the rubberized cloth, spray water equivalent to the boat's traveling speed is directly sprayed on the rubberized cloth, and the degree of deterioration is evaluated. There is a WJF (Water Jet Fragrator) test device that evaluates This method is shown in FIG.

FIG. 3 is a conceptual diagram of a durability test. In this figure,
The rubber cloth 3 is formed into the dimensions and shape shown, and is used as a specimen for a durability test machine for a skirt material or a sealing material. The nozzle 5 is arranged at an angle of about 45 ° with respect to the specimen vertically fixed to the jig with bolts, and spray water 4 corresponding to the boat speed of the air cushion boat is sprayed from the nozzle 5 onto the specimen. As a result, the coating rubber is peeled off or deficient in the specimen to which the jet water 4 is sprayed, and the cut 6 further extends upward. When the portion surrounded by the cut portion 6 violently flutters with the jet water, the portion is torn off from its lowermost end, and the fibers are separated from each other. The life is defined as the time until it is determined that the test piece is unable to exhibit the function as a sealing material due to the occurrence of these peeling, chipping, cracking, and tearing.

The durability of a conventional rubberized cloth was limited to about 2,000 minutes, but as a result of changing the hardness (JIS hardness) of the rubber and conducting a WJF test, the longer the life of the rubber, the higher the hardness. The thing turned out. This is simply the loss factor of the rubber (tan δ)
Regardless of the value of, it has been found that the high initial modulus makes it less susceptible to physical deformation, resulting in a longer life than conventional products.

 Examples and comparative examples are shown below.

[Examples and Comparative Examples]

A warp and weft 1260 denier 66 nylon plain weave was immersed in a resorcinol formalin latex solution, and coated with an elastomer having the formulation shown in Table 1 below. The durability test shown in the figure (spray water speed 80 knots) was performed. As a result, the JIS hardness of the elastomer coated on the specimen up to 58 is about 3,000.
The JIS hardness of 65 and 76 was as long as 10,000 to 25,000 minutes and 30,000 to 60,000 minutes, respectively. The result is shown in FIG. The numbers in FIG. 4 indicate the material temperature of the specimen measured by an infrared thermometer micro-scanner (manufactured by Exagen Corp., USA) by wiping off moisture adhering to the specimen immediately after the test was stopped.

Table 2 shows the basic physical properties of the coated rubber and the rubberized cloth.
Further, it was visually observed that the specimen of specimen type C-4 had less flutter (vibration) of the specimen due to the jet water during the WJF test than C-1.

[Effects of the Invention] As described above, according to the present invention, the JI
Rubberized cloth coated with S hardness of 70 to 90 has a long life. Therefore, if this is used as a seal material for an air cushion boat, it can be used for a long time, and (a). It can withstand long distance operations.

(B). Increases boat operation efficiency.

(C). The time interval required for changing the sealing material is increased.

Such effects can be expected.

[Brief description of the drawings]

1 and 2 are model perspective views including a cross section of a rubber-coated cloth of the sealing material for an air cushion boat according to the present invention. FIG. 1 is a model drawing of a plain weave, and FIG. Warp,
FIG. 3 is a cross-sectional view showing a case where each single yarn of the weft is densely woven with each other, FIG. 3 is an explanatory view showing a WJF test method of a seal material for an air cushion boat, and FIG. 4 is a CR coating test according to hardness. It is a graph explanatory view showing the test result of a piece.

Continuation of the front page (72) Inventor Minoru Naito 2-22-17-41 Higashiyama, Meguro-ku, Tokyo (72) Inventor Seiichiro Nishihara 2-11-13 Masago, Chiba City, Chiba Prefecture (72) Inventor Shiro Ono Chiba Chiba Prefecture 2-9-10 Satsukigaoka, City (72) Inventor Kazuo Kato 94-2, Kawachi, Hiratsuka-shi, Kanagawa (56) References Japanese Utility Model Application Sho 61-107535 (JP, U) Japanese Patent Publication No. 3-80623 (JP, B2)

Claims (1)

(57) [Claims] 1. A sealing material for an air cushion boat, comprising a plain woven fabric covered with natural rubber having a JIS hardness of 70 to 90, synthetic rubber and various blended rubbers.