JPS5822394B2 - Boat Sentai Mataha - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing boat hulls and other hollow objects.

Foam reinforced plastics (FoamReinf) are commonly used.
Orced Plastic (FRP), commonly known as FRP, is often used to make boat hulls.

FRP consists of a low-density core material sandwiched between a denser exterior material.

The core is shaped into the desired shape and the outer layer is secured to the core by mechanical bonding.

The heartwood must be sufficiently hard and shear resistant so that the surface does not peel.

PVC foam is an example of this type of core material, which additionally has the ability to recover after compressive loading and thus is resistant to vibration.

PVC foam and glass fiber and polyester resin are typical materials suitable for sandwich construction.

One known method of sandwich construction used in boat construction is the Male Plug Method.
) Male Mo1d Method
) is commonly known as.

This method involves creating an inverted oval plug or mold of the desired boat hull and securing it to a flat floor.

This type consists of mutually parallel frames or ribs running across the hull and several longitudinal battens fixed to them.

These battens are spaced several inches apart.

The PVC foam sheet is cut and shaped into the mold, and then bent and heated to form the sheet to approximately enclose the mold.

These PVC foam panels are then either secured to the batten from the inside of the mold with wood screws or blunt nails, or the foam and batten are secured to the batten from the outside, ensuring that the foam is securely fastened to the batten. It is fixed with long nails that go through it.

Each panel of the form is fixed to a batten next to each other until it covers the entire surface of the hull, and then a butt joint (also called butt joint) is made between each form panel.
tt joints) are filled with grout and polished to facilitate attachment of the skin.

Next, G RP (Glass Fiber Re1nf
(orced Pi-astic) To form the outer shell, first coat the surface of the PVC foam with a fast-curing polyester resin, soak it sufficiently with the polyester resin, and then use chopped mats of glass fiber, plain weave roving, or woven roving that have not yet dried. (unidirectiona
and 10r wave roving) etc.

The hull surface is usually polished and finished at this stage.

This hull, consisting of PVC foam with a GRP skin, is released from the wooden mold.

Remove the wood screws, nails, or fasteners to free the inner surface of the form from the batten.

Next, lift the hull sufficiently from the wooden mold, turn it over, and use a chock to stand the hull upright.

Next, the GRP endothelium is coated with TiGRP in the same way as the outside of the hull.
A sandwich of PvC foam is formed between the two sides.

The upper hull deck is constructed either in the same way as the hull or by attaching separate panels to the beams.7 Disadvantages of this female frame method are: a. Cutting and tailoring the form into panels to accommodate complex curves; The process is inefficient and requires a high degree of skill.

b) It is necessary to tighten a large portion of the PVC foam to the wooden batten using varying degrees of tension.

Since the polyester resin generates heat during its curing process, the interface between the PVC foam and the GRP laminate is warmed, thus reducing the stiffness of the foam.

At the same time, shrinkage occurs during curing of the laminate.

As a result of this action, strains are created on the surface of the hull.

If a slow curing resin is used to reduce heat transfer from the laminate to the foam, there is a risk of styrene volatilization from the resin on top of the foam, causing softening and similar distortion of the foam.

This occurs particularly in areas where pressure is applied to bring the foam and malt into close contact.

It is difficult to mold and install a GRP layer on the malt from the horizontal part of the center of the C-hull to the vertical part of the ship's edge, since it is difficult to avoid deformation of the shape.

d. Standardized control of the lay-up of both the outer skin and the inner skin becomes difficult when constructing scaffolding to facilitate the handling of resin and glass materials by workers throughout the hull.

Special ventilation is required for working with the inner GRP skin.

e. When an operator finishes laminating glass fibers and molds the next layer while the glass fibers are still semi-cured, a slow-curing resin is usually used.

However, in this case, it is necessary to polish away the rough corners of the laminate from the surface in the semi-cured state between each forming of the laminate.

f When removing the wooden female frame, it is likely to damage the stopper itself and the inner surface of the foam.

g It is necessary to lift, turn over, and lower the unfinished hull in order to form the inner surface, and to place the hull in an upright position to avoid the development of distortion during the forming of the inner surface. However, these things require skill and time on the part of the operator.

h As a result of points a, b, c, d, e and f above, a significant amount of filling and polishing is required to produce a finished product comparable to hulls made by other methods.

The female frame method is usually used for one-off hull construction or for the construction of a small number of hulls.

Furthermore, the structural advantage of unitary sandwich construction is that complex curves can be effectively achieved and that localized areas of the hull can be easily reinforced by using plain-woven glass fiber rovings or woven rovings. However, this must be balanced against the costs of molding management and finishing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for building a boat hull that retains the advantages of sandwich construction and reduces or eliminates its disadvantages.

The present invention involves preparing one male mold, applying a release agent on the male mold, covering the mold release agent on the male mold with a layer of fiber impregnated with resin, The fibers are then wrapped with at least one layer of synthetic foam, and the foam is then wrapped again with at least one layer of resin-impregnated fibers to form a sandwich of foam sandwiched between layers of fibers. However, there is a method for making boat hulls and other hollow objects constructed by cutting this sandwich into at least two parts and removing the male mold.

According to the above method, by making one of the divided parts into a single hull, it is possible to manufacture two hulls from one male mold.

Alternatively, single deck boats can be constructed using the method of the present invention.

The present invention also has the advantage of being suitable for use by unskilled workers and for long hours on a line.

Using the convenient method of application of the present invention, for example, the fuselage of a small airplane can also be made (if the opportunity arises) using this method and materials.

The yacht's hull and deck are one unit.
If considered as a ship, its top and bottom parts will be designed to absorb the pressure and tension loads applied by the bow and stern guy lines.

The manufacturing method of the present invention is as follows.

A rotatable male mold is provided and the material to be sandwiched is glued around it.

This male form is effectively a complete hull and deck unit, but the cross-sectional radius is smaller than the completed hull by the thickness of the finished sandwich molding.

This male mold is supported at both ends and is slowly rotated by a motor and gears, allowing the material to be unrolled, trolley-mounted, continuously wrapped, or under tension on the male mold. I can do it.

This male mold is coated with a mold release agent such as PVA or wax.

Polyester resin is activated and applied to the male mold to the appropriate width.

A woven glass fiber roving of the same width is attached under tension while the resin is wet.

This alternating operation of resin and fibers is repeated twice or as many times as desired for laminating the inner skin, and then a suitable width of P
VC foam is wrapped around the fast-curing resin layer under tension before it dries.

A light wide glass fiber mesh is then wrapped and compressed to ensure crimping of the PvC foam.

Furthermore, a fast-curing resin is applied thereon.

PVC with fast curing resin to prevent styrene action
Once the foam is well sealed, begin molding the outer skin layer.

At this stage, various molding failures are corrected by adding fillers.

The laminate is created into the desired shape in the same way as the inner epidermis.

Final finishing is accomplished by positioning floats, grades, wipers, etc.

At this stage, the final finish may be improved by wrapping strips of Melanex®, 1.001 inch aluminum plate, or suitable polyester resistor film as a modification of the above method to complete the completed hull construction. The final step is to remove the inner male mold by cutting the hull in half and rejoining these halves.

This process can be made more efficient if, for example, you apply a mold release agent in advance or insert a horizontal insert into the mold so that the sandwich molding has a groove in the largest position of the hull beam. You can do it.

By inserting a knife or saw into this groove,
Cutting the hull into the head and bottom is guided accurately and cleanly.

Next, lift the head of the hull sufficiently, and then lift the wooden mold from the bottom and remove it.

The form at the top edge of the bottom of the hull is chiseled down to the appropriate depth.

Apply resin to this groove and insert the tank prepared in advance.

A similar groove is also cut on the lower edge of the upper deck section of the hull.

Apply resin to the top of the tongue, lower the deck part so that the tongue fits into the groove, and finally wipe off the excess resin.

At this stage, when the skin resin is in the middle of hardening, holes for the cockpit, windows, etc. can be made without worrying about deformation of the hull.

In this state, before the resin has finally hardened, internal bulkheads, keel stringers, floors, furniture, etc. can be effectively bonded to the interior or exterior surfaces of the hull.

, changes in the molding procedure can be made, for example, by attaching plain weave fibers vertically to the surface of the wooden mold before the inner skin molding step, or by adding plain weave fibers to the outer surface of the hardened foam before the outer skin molding. You may also attach it to your computer in the same way.

heat may be applied locally to both sides of the PVC foam during molding;

The width of the PVC foam is increased by using the foam with grooves on one or both sides so that only the central area is compressed during bending.

1. In sandwich boat hull construction, the ratio of foam core thickness to GRP skin is 5 per cubic foot.
．． Approximately 6 to 1 for 1 pound density foam heartwood
It is.

The thickness of the skin laminate and the combination of glass fibers within it can be varied to absorb local loads.

To spread the load over both skins, for example, use comp instead of PVC foam where the bolt passes through the core material.
re ss i honor distance pie
ce (crimping material or distance material) may be inserted.

In this regard, it is preferable to use another layer to spread the load over a wide area, rather than adding a pressure bonding material.

compression plug or compression plate
g plate) and electrical circuitry should be inserted into the core before fitting the outer skin, if appropriate.

As an application of the present invention, a sandwich structure is used to simplify the construction of an FRP boat hull.

The ability to rotate the mold with controlled tension and the ability to apply material across complex curves are fundamental advantages of this system.

This applies in particular to the effective bonding of PvC foams with GRP envelopes.

By making very slight modifications to the design of the boat hull and the composition of the materials used in the FRP construction, compared to the existing common method of sandwich construction, without compromising the performance of the hull or the mechanical and structural properties of the material. This results in less wastage of materials, standardized production control, and much labor savings.

The present invention uses both lay-up and mechanized lay-up methods to fabricate products from male molds.

The present invention further has the following advantages.

Air bubbles in the resin are forced to the surface from each laminate by applying tension to a narrow area of material around the mold.

The shrinkage of the resin upon curing has the effect of increasing the tension of the glass fibers around the mold, which makes the mechanical bond between the foam and the glass fibers more secure.

There is a chemical bond between the outer skin and inner skin of the glass fibers along the abutment bonds within the foam.
will be carried out.

The butt joints with the fiber strands (5
trand) is reinforced to create an H-shape of GRP.

Fast curing resins are used not only to increase the speed of layup, but also to reduce or even eliminate styrene effects.

In the case of polyester resins and semi-rigid non-plastic PVC foams, the slow curing resin causes the foam to be locally transformed and strained.

Fragile or rigid PVC foam strips can be bent along complex curves by applying localized heat.

Localized heating at the point of layup accelerates resin curing and increases layup speed.

For interior and exterior color finishing, single or multicolored resins are used for both the inner and outer laminates.

The finished hull is cut into two or more pieces for removal from the mold within 15 minutes after completion of layup.

In this way, virtually no distortion occurs.

Since there are no strained parts, each part can be stored separately for curing without a mold.

After curing, the parts are joined together without the trouble of misalignment or mating.

This is not possible using the normal GRP method.

By using fibers reinforced by precisely controlling and combining the ratio of resin and fibers during layup, it is possible to
It is possible to provide products with superior strength per weight compared to those made by the method.

Although the invention has been described primarily for the purpose of manufacturing boat hulls, the method can also be applied to pipes, containers or any other object suitable for applying fiberglass and foam by the method described heretofore. I can do it.

The embodiments of the present invention will be described below.

1. The method as claimed, further comprising covering the outer layer of the fibers with a polyester resistor film.

2. The method as claimed in the claims or the preceding paragraph, further comprising butt-coupling the longitudinal and lateral sides of the foam.

3. The inner layer impregnated with resin is formed by applying a mold release agent and resin and winding one layer of fibers while applying tension, and any of the claims 1 and 2. That method.

4. The method according to any one of claims 2 and 3, wherein the male mold is arranged so as to be rotatable.

5. A resin is applied onto the inner layer consisting of one or more fibers, and several sheets of foam are wrapped around this under tension, so that adjacent foams are butt-bonded at the ends of each foam. The scope of the claims and the first claim are as follows:
Any method from Section 4 to Section 4.

6. The claims and claims 1 to 5, in which the outer surface of the foam is coated with a resin and an outer layer consisting of one or more fibers is wound thereon so that the resin penetrates into the outer layer of the fibers. Either way.

7. The method of any of claims 1 to 6, wherein the pigment is applied in a single layer to the inner and/or outer layer of the fiber.

8. Claims and items 1 to 7 in which heat is applied to the foam before wrapping it around the male mold.
Either way.

Claims (1)

[Claims] 1 Prepare one male mold, apply a mold release agent to this male mold, cover the mold release agent on this male mold with a layer of resin-impregnated fibers, and then apply at least one layer around this fiber. a synthetic foam, and further wrapping around the foam at least one layer of resin-impregnated fibers to create a foam sandwich sandwiched between layers of fibers, and cutting the sandwich into at least two parts. A method of making a boat hull which is constructed by removing the male mold by making a still hollow object.