JP5510902B2 - Manufacturing method of pressure vessel - Google Patents

Description

  The present invention relates to a method for manufacturing a pressure vessel. More specifically, the present invention relates to an improvement in a method for manufacturing a pressure vessel in which an FRP layer on the outer periphery of a liner is formed by a prepreg.

  As a pressure vessel such as a high-pressure tank used for storing a high-pressure gas such as hydrogen, one having an FRP reinforcing layer on the outer periphery of a liner is used. The reinforcing layer of FRP is formed by, for example, FW (filament winding) of a ribbon-like material called a prepreg around the liner (see, for example, Patent Document 1).

JP 2009-184223 A

  However, conventionally, when the end portion of the prepreg wound around the liner rides on the adjacent prepreg, a partial thickness increase may occur, or a uniform cross section may not be obtained due to a gap formed between the prepregs. As a result, the strength of the FRP layer and thus the entire container may be reduced.

  Then, an object of this invention is to provide the manufacturing method of the pressure vessel which suppressed the boarding of the prepreg and generation | occurrence | production of the clearance gap between prepregs, and stabilized the intensity | strength.

  In order to solve this problem, the present inventor has made various studies. The general cross-sectional shape of a conventional prepreg is a rectangle, and it is difficult to wind the prepreg having such a cross-sectional shape without any gaps in a situation where the production speed is also required. is there. In particular, the feed speed of the yarn feeder of the FW machine is usually constant, but if the width is not constant as in the case of the conventional prepreg (see FIG. 12), thick and thin parts are concentrated on a part of the prepreg side. A part may run on a side part of an adjacent prepreg to create a gap, or a gap may be created between the side part (see FIGS. 3 and 13). The present inventor who has further studied the present situation that these obstruct the formation of FRP with a uniform cross-section and cause the strength of the pressure vessel to decrease. ) So that the cross-sectional area should be uniform, we have obtained new knowledge that leads to the solution of this problem.

  The present invention is based on such knowledge, and is a method of manufacturing a pressure vessel having a liner and an FRP layer that wraps the outer periphery of the liner, and a prepreg including a flat plate portion formed with a predetermined number of fibers in the width direction. It is made into a string by folding or winding and wound around the outer periphery of the liner.

  In the present invention, even if the thickness and width of the sheet-like prepreg are not constant, the prepreg is folded or wound in the width direction and wound around the liner after forming a uniform-diameter string. Therefore, it is difficult for a gap due to riding up to occur. Further, since a tensile tension acts on the prepreg, even if the prepreg is slightly deviated during winding, the prepreg can be accommodated in a valley between prepregs that have already been wound. According to the present invention, the strength of the pressure vessel can be stabilized by suppressing the prepreg ride and the generation of a gap between the prepregs.

  In such a pressure vessel manufacturing method, it is preferable that the prepreg is formed in a string shape and then the cross section is formed into a square and then wound around the outer periphery of the liner. Thus, by making a cross section into a square, the clearance gap between the prepregs at the time of winding can be reduced.

  Moreover, in this manufacturing method, a string-like prepreg can be passed through a roller and the cross section thereof can be formed into a quadrangle.

  Furthermore, it is also preferable that the cross section of the string-like prepreg is formed into a rhombus or a parallelogram.

  Further, the prepreg according to the present invention is a prepreg used for manufacturing a pressure vessel having a liner and an FRP layer that wraps the outer periphery of the liner, and is formed into a flat plate shape with a predetermined number of fibers, and then the width direction. It is made into a string shape by being folded or rolled up.

  According to the present invention, it is possible to stabilize the strength of the pressure vessel by suppressing the climbing of the prepreg and the generation of a gap between the prepregs.

It is a figure which shows the simplification of the cross-section of a high pressure tank (pressure vessel). It is a figure which shows a mode that a prepreg is wound around a tank main body by FW machine. It is a figure which shows the example of a shape of the flat plate part of a prepreg, (A) An example with a small width and a large thickness, (B) An example with a large width and a small thickness. It is a figure which shows the prepreg which wound the flat plate part in the width direction, and was shape | molded in the shape of a string, (A) A string-like prepreg when a flat plate part is small and thick, (B) When a flat plate part is wide and thickness is small This is a string prepreg. It is sectional drawing which shows the string-like prepreg wound around the liner. It is a figure which shows a mode that a string-like prepreg is wound around the outer periphery of a liner, making a tension tension act. It is a figure which shows a mode that the restraint force has generate | occur | produced in the string-like prepreg which the tension tension acted on. It is sectional drawing which shows the prepreg of a cross-section rhombus wound around the liner without gap. It is a figure explaining the tension difference of the inner and outer periphery of a prepreg at the time of winding around the outer periphery of a liner. It is a figure which shows a mode that a string-like prepreg passes sequentially between two pairs of rollers, and is shape | molded in a cross-sectional square. It is sectional drawing which shows what has an elliptical cross section as another example of a string-like prepreg. It is a figure which shows the conventional prepreg whose width | variety is not constant for reference. It is a figure which shows as a reference the prior art which produced the run-up and the clearance gap when winding a prepreg.

  Hereinafter, the configuration of the present invention will be described in detail based on an example of an embodiment shown in the drawings.

  1 to 7 show an embodiment of a pressure vessel manufacturing method according to the present invention. Hereinafter, for example, a pressure vessel (hereinafter also referred to as a high pressure tank) 1 as a hydrogen fuel supply source used in a fuel cell vehicle will be described as an example, and the structure of the high pressure tank 1 will be described as an example.

  The high-pressure tank 1 includes, for example, a cylindrical tank body 10 whose both ends are substantially hemispherical, a base 11 disposed at a longitudinal end of the tank body 10, a main stop valve (not shown) attached to the base 11, and the like. (See FIG. 1). In FIG. 1, a dome portion that is a substantially hemispherical portion of the high-pressure tank 1 is denoted by reference numeral 1d, and a straight portion that is a cylindrical body portion is denoted by reference numeral 1s.

  The tank body 10 has, for example, a two-layer wall layer, and has a liner 20 as an inner wall layer and an FRP layer 21 as a resin fiber layer (reinforcing layer) as an outer wall layer on the outer side. The FRP layer 21 can be formed by, for example, a CFRP layer alone or a combination of the CFRP layer and the GFRP layer.

  The liner 20 is formed in substantially the same shape as the tank body 10. The liner 20 is made of, for example, polyethylene resin, polypropylene resin, or other hard resin. Alternatively, the liner 20 can be a metal liner formed of aluminum or the like. An opening is formed at the end of the liner 20 in the longitudinal direction, and the base 11 is inserted. A valve assembly that functions as a main stop valve is fitted into the base 11.

  The base 11 has a substantially cylindrical shape and is fitted into the opening of the liner 20. The base 11 is made of aluminum or an aluminum alloy, and is manufactured in a predetermined shape by, for example, a die casting method. The base 11 is fitted into the injection-molded split liner, but may be attached to the liner 20 by insert molding, for example.

  The FRP layer 21 is formed by winding a prepreg 70 including fibers (reinforcing fibers) impregnated with resin around the outer peripheral surface of the liner 20 and a part of the die 11 by, for example, filament winding molding (FW molding), and curing the prepreg 70. It is formed by. For the resin of the FRP layer 21, for example, an epoxy resin, a modified epoxy resin, an unsaturated polyester resin, or the like is used. Moreover, as the prepreg 70, carbon fiber (CF), a thing containing a metal fiber, etc. are used. During filament winding molding, the guide (FW machine yarn inlet 71) of the prepreg 70 is moved along the tank axis direction (at a constant feed rate) while rotating the liner 20 around the central axis of the tank body 10. The prepreg 70 can be wound around the outer peripheral surface of the liner 20 (see FIG. 2).

  Next, an example of a manufacturing method of the high-pressure tank 1 in which the strength is stabilized by suppressing the riding of the prepreg 70 and the generation of a gap between the prepregs 70 at the time of FW will be described (see FIG. 8 and the like). In the present embodiment, a prepreg 70 having a flat plate portion is wound to form a string, and the string-like prepreg 70 is wound around the outer periphery of the liner 20.

  The prepreg 70 wound around the liner 20 is formed with a predetermined number of fibers so as to have a flat plate portion (indicated by reference numeral 70a in FIG. 3). For example, the prepreg 70 is narrow (small) and thick. Conversely, the thickness and width may vary depending on the site, such as wide (large) and small (thin) thickness (see FIG. 3). In the present embodiment, by winding such a prepreg 70 so as to be rounded in the width direction, in other words, by winding the plate-like prepreg 70 in a direction perpendicular to the longitudinal direction to form a spiral cross section, A prepreg (indicated by reference numeral 70b in FIG. 4 and the like) is used. When the prepreg 70 is formed with a predetermined number of fibers, if the prepreg 70 is wound spirally without a gap so as to be solid, it becomes substantially circular regardless of the thickness and width of the flat plate portion 70a. The cross-sectional area of the string-like prepreg 70b is substantially the same (see FIG. 4). As described above, if the cross-sectional area of the prepreg 70 is made substantially the same before being wound around the liner 20 and the outer shape is made uniform (substantially circular), the prepreg 70 will be ridden and a gap resulting from the ridging will be generated. It can be suppressed (see FIG. 5).

  When winding the prepreg 70, the winding is performed with the highest tension when winding the first layer. Further, when the string-like prepreg 70b is wound in this way, the prepreg 70 wound later in time tends to naturally fall into the gap between the adjacent prepregs 70 (the valley of the prepreg boundary portion). Further, a gap on the inner peripheral side between adjacent prepregs 70 (prepreg boundary part) is in a state in which a part of the prepreg 70 wound on the inner layer side from the gap enters. From the above, even if the prepregs 70 are overlapped with each other, they do not ride on each other, and no gaps are caused by riding (see FIG. 5).

  Moreover, when the prepreg 70 having a substantially circular cross section is used, there is an advantage that even if the prepreg 70 is slightly deviated, the tensile tension at the time of winding acts to eliminate the deviation. That is, when a tensile tension is applied, a component force is applied to the wound prepreg 70 to move downward (inner peripheral side) along the outer peripheral surface of the prepreg boundary portion (FIG. 6, (See FIG. 7). Such a component force acts to reduce the gap by moving the prepreg 70 toward the prepreg boundary portion even if the prepreg 70 is wound with a slight shift. In short, the rotation of the tank body 10 and the tensile tension act in the direction of restraining the prepreg 70 into the valley between the prepregs 70.

  According to the manufacturing method as described above, it is possible to reduce the gap that may be generated when the prepreg 70 is wound, and to form the FRP layer 21 having a more uniform cross section. Therefore, according to this, the strength of the high-pressure tank 1 can be made more stable.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, in the embodiment described above, the prepreg 70b formed in a string shape with a substantially circular cross section is wound around the liner 20, but it is also preferable that the prepreg 70 formed in a string shape is further formed into a square shape and then wound around the liner 20. . Thus, by making the cross section of the prepreg 70 square, the gap between the prepregs 70 during winding can be further reduced (see FIG. 8). More specifically, the cross-sectional shape of the prepreg 70 is preferably a rhombus or a parallelogram. For example, when the prepreg 70 having a rhombus cross section is used, even if the prepregs 70 overlap each other, they do not ride on each other, and it is difficult to generate a gap due to the ride. Further, the gap between the adjacent prepregs 70 can be filled with the prepreg 70 wound on the inner layer side with respect to the gap and the prepreg 70 wound on the outer layer side. According to this, since a uniform cross section can be formed, the strength of the pressure vessel can be further stabilized.

  It is also preferable to mold the prepreg 70 so that its thickness is reduced. In general, in a FW object such as the prepreg 70, the difference in tension between the inner and outer circumferences increases as the center diameter of the liner 20 with respect to the thickness of the prepreg 70 becomes thinner, so the possibility of fiber breakage increases (see FIG. 9). Therefore, when the cross section is square as described above, for example, if the thickness is reduced as a wide rhombus, it is possible to suppress an increase in the tension difference between the inner and outer circumferences.

  As described above, an example of a method for forming the string-like prepreg 70b into a square cross section is to form the prepreg 70b by sequentially passing between two pairs of rollers. Specifically, the string-like prepreg 70b is first flattened by a process of passing between a pair of upper and lower rollers 81, and then left and right is flattened by a process of passing between a pair of left and right rollers 82, and formed into a square cross section. (See FIG. 10).

  Further, in the embodiment described so far, the flat prepreg 70 is formed in a string shape by winding it in the width direction (see FIG. 4 and the like). This is a uniform (uniform) cross section of the prepreg 70. It is only a suitable example for making it. In short, the specific means is not limited as long as the cross section of the prepreg 70 can be made uniform. For example, the flat prepreg 70 may be folded to make the cross section uniform. In addition, the cross-sectional shape at that time is not limited to a circle or the like as long as it is uniform.

  In addition, from the viewpoint of preventing the prepregs 70 from riding on each other at the time of FW, the cross-sectional shape of the prepregs 70 can be elliptical. In such a case, as in the case where the cross section is a rhombus, the rotation and the tension tension act in the direction of restraining the prepreg 70 in the valley between the prepregs 70 (see FIG. 11).

  In addition, although the case where a cross section is a rhombus was illustrated and demonstrated in the above-mentioned embodiment, the rhombus here is not restricted to the rhombus in the exact | strict geometrical meaning. The point is that the purpose of using the prepreg 70 having a diamond-shaped cross section in the above-described embodiment is to eliminate the gap so that the prepregs 70 do not run over each other even if they overlap each other. Strictly not a diamond-shaped cross-sectional shape (a shape that conforms to the diamond, but strictly speaking, each side is not a straight line, each side is not equal in length (for example, a parallelogram shape), etc. Prepreg) should be construed as being included within the preferred scope of the present invention.

  The present invention is suitable for application to the manufacture of a pressure vessel in which the FRP layer on the outer periphery of the liner is formed by prepreg.

DESCRIPTION OF SYMBOLS 1 ... High pressure tank (pressure vessel), 20 ... Liner, 21 ... FRP layer, 70 ... Pre-preg, 70a ... Flat plate part, 70b ... String-like prepreg

Claims (5)

A method of manufacturing a pressure vessel having a liner and an FRP layer surrounding the outer periphery of the liner,
A prepreg having a flat plate portion formed with a predetermined number of fibers is folded or wound in the width direction and wound around the outer periphery of the liner,
A method for manufacturing a pressure vessel.   The method for manufacturing a pressure vessel according to claim 1, wherein the prepreg is formed into a string shape, and then the cross section thereof is formed into a square and wound around the outer periphery of the liner.   The manufacturing method of the pressure vessel of Claim 2 which passes the said string-like prepreg through a roller, and shape | molds the cross section in a square.   The manufacturing method of the pressure vessel of Claim 3 which shape | molds the cross section of the said string-like prepreg to a rhombus or a parallelogram. A prepreg used for manufacturing a pressure vessel having a liner and an FRP layer that wraps the outer periphery of the liner,
A prepreg formed into a flat plate shape with a predetermined number of fibers and then folded or wound in the width direction to form a string.

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