JP2008290269A - Method for forming through-hole in fiber-reinforced resin sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a through-hole in a fiber-reinforced resin sheet in which the fibers are pushed away at the part of the hole, in a manner by which the peripheral part of the hole is strongly reinforced. <P>SOLUTION: An annular structure effective for reinforcing the peripheral part of the hole is incorporated in the fiber pushing-away allowance part for the through-hole of the fiber-reinforced resin sheet. The above is conducted based on the knowledge that, when the fibers present in the part to become the hole are pushed away to both sides, even if the degree of the pushing-away is somewhat more than the minimal adequate to the size of a desired hole, the drop of the strengths of the fiber-reinforced resin sheet due to the stress concentration after the fiber pushing-away does not differ significantly and, rather than that, somewhat enhancing the degree of the pushing-away of the fibers and newly adding a fiber-reinforced resin layer onto the allowance part are more effective for increasing the strengths of the through-hole. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for forming a through hole in a fiber reinforced resin sheet.

As a method of forming a through-hole in a fiber reinforced resin sheet, the following Patent Document 1 describes a process in which a fiber reinforced resin material composed of continuous reinforced fibers and a thermoplastic resin matrix is heated and has a sharp tip. A method of drilling a fiber reinforced resin material is described, in which a thermoplastic resin matrix is melted and perforated while being moved to the periphery of the processed member so as to push the reinforcing fibers separately by the member. . Similarly, as a method for forming a through-hole in a fiber reinforced resin sheet, Patent Document 2 below discloses that a conical jig is provided on a reinforced fabric made of reinforced multifilament yarn that is flat and substantially untwisted. A method for producing FRP (fiber reinforced plastic) having a hole, characterized in that a woven yarn is locally misaligned by insertion to form an opening, and the reinforcing fabric is impregnated with a resin and then cured. Has been.
JP 7-186100 A JP-A-7-242756

  As described in Patent Documents 1 and 2 above, in making a hole in the fiber reinforced resin sheet, without cutting the fiber in the part that becomes the hole, by scraping it on both sides of the hole, When the fibers are cut by drilling, the strength of the fiber reinforced resin sheet can be prevented from being significantly deteriorated due to the breakage of the fiber reinforced resin sheet starting from the hole portion where the fiber is cut.

  However, not only the fiber-reinforced resin sheet, but if a hole is made in a sheet-like object, stress concentration occurs around the hole when a force is applied along the sheet, so the strength of the sheet-like object is at the hole. It is inevitable that the drop will occur. The reduction in strength in the hole portion of the sheet-like object due to such perforation is devised so as not to cut the fiber when making a hole in the fiber reinforced resin sheet, as described in Patent Documents 1 and 2 above. It is essentially inevitable.

  By the way, in forming a through hole in a fiber reinforced resin sheet, if it is scraped to both sides of the hole without cutting the fiber in the hole portion, it will disturb the original distribution of the fiber. As a matter of course, it is desirable that the degree of scraping is as small as possible. In the methods described in Patent Documents 1 and 2, the degree of scraping of the fibers for forming the holes can be determined as desired. The minimum is necessary to form the hole in accordance with the size. However, if the fibers are to be scraped anyway to form holes, the fiber reinforced resin sheet due to stress concentration after local scraping of the fibers, even if the degree is somewhat larger than the minimum required to form the holes There is no big difference in the strength reduction of the fiber, and if there is some margin in the fiber scraping degree, and a new fiber reinforced resin layer is added to the margin, fiber reinforcement by drilling It is considered that it is possible to compensate for or offset the decrease in the strength of the resin sheet, or even to increase the strength of the fiber-reinforced resin sheet in the hole portion more than the strength in the portion without the hole. In particular, the strength of the sheet-like object is reduced when a hole is drilled there, because a crack is generated at the peripheral part of the hole, and if the peripheral part of the hole is strengthened against the occurrence of the crack. In addition, a decrease in the strength of the sheet-like object due to perforation should be largely avoided.

  The present invention pays attention to the above circumstances, and when the fiber and the resin are scraped into the fiber reinforced resin sheet and the through hole is opened, the degree of scraping is not limited to the minimum necessary for the formation of the hole but is somewhat larger than that. A method of forming a through-hole so that the fiber-reinforced resin sheet is more reinforced at the through-hole portion by incorporating a strong annular structure against the occurrence of cracks in the margin portion for fiber separation obtained thereby It is an issue to provide.

  In order to solve the above problems, the present invention is a method of forming a through hole in a fiber reinforced resin sheet, and is present in a part of the fiber reinforced resin sheet that becomes the through hole and in an annular zone along the periphery thereof. By separating fibers and resin around, an enlarged through hole is formed by enlarging the through hole by the annular zone, and extends along the ring of the annular zone to a portion of the annular zone of the enlarged through hole. The present invention proposes a method characterized by incorporating an edge ring made of fiber and resin.

  In this case, the edge ring may be fixed to the fiber reinforced resin sheet in the enlarged through hole by fusing the resin of the fiber reinforced resin sheet and the resin of the edge ring.

  The rim ring may be formed by cutting out from a cylindrical body that includes fibers and resin extending along the ring and has a length that is a multiple of the rim ring thickness or more.

  A small hole is formed in the edging ring across an intermediate portion of the radial width, and a fiber radially inward of the small hole among fibers extending along the ring of the annular zone has the small hole. It may be bundled with a wire that passes through. Bundling fibers that are radially inward from the small holes by the wire may be performed at a plurality of locations along the ring of the edging ring.

  When the perforation ring is formed with a small hole across the middle of its radial width, the perimeter ring includes fibers and resin extending along the annulus and multiple times or more the thickness of the perimeter ring When formed by cutting out from a cylindrical body having a length, the small hole may be formed at a point in the state of the cylindrical body before the edging ring is cut out. In this case, in the cylindrical body, a cylindrical portion radially inward from the small hole is formed first, and then a rod-shaped body is installed in a portion to be the small hole, and from above the radial direction from the small hole. A cylindrical portion on the outside may be formed, and then the rod-shaped body may be removed to form a cylindrical body including a gap that becomes the small hole.

  The fiber-reinforced resin sheet starts from the tip when the resin of the fiber-reinforced resin sheet is in a state where the resin can flow through a cone whose cross section expands from the sharp tip to the cross-sectional contour of the enlarged through-hole. It may be formed by penetrating through.

  As described above, when the through hole is formed in the fiber reinforced resin sheet, the fiber and the resin present in the annular zone along the peripheral portion and the peripheral portion of the fiber reinforced resin sheet are separated. An enlarged through hole is formed by enlarging the through hole by the annular zone, and an edge ring made of a fiber and a resin extending along the ring of the annular zone is incorporated in the annular zone of the enlarged through hole. By doing so, by making the degree of fiber scraping for forming the through hole slightly larger than the size of the through hole, the peripheral part of the through hole of the desired size was added separately. It can be formed as a structure reinforced by the edging ring, and the edging ring is made of a fiber and a resin extending along the ring of the annular zone, so that the peripheral portion of the through hole extends along the rim. Reinforced with fibers standing, the formed pores may be assumed to have a high resistance to cracking.

  In this case, if the rim ring is fixed to the fiber reinforced resin sheet in the enlarged through hole by fusing the resin of the fiber reinforced resin sheet and the resin of the rim ring, the fiber reinforced resin sheet side Due to the combination of the resin and the resin on the side of the edging ring, the edging ring can be more firmly attached along the periphery of the enlarged through hole of the fiber reinforced resin sheet.

  If the rim ring is formed by cutting out from a cylindrical body containing fibers and resin extending along the ring and having a length of a multiple of the rim ring or more than that, it is incorporated into the enlarged through-hole. When this is done, an edging ring with fibers extending along the periphery of the through hole can be efficiently produced.

  A small hole is formed in the edging ring across an intermediate portion of the radial width, and a fiber radially inward of the small hole out of the fibers extending along the ring of the annular zone passes through the small hole. If bundled with a wire, even after the rim ring is attached in the enlarged through hole of the fiber reinforced resin sheet, the fiber extending along the peripheral edge of the through hole, particularly in the radially inner periphery, the through hole The fibers that are prone to fraying by an external force exerted by other members that engage with each other are bundled together to be firmly held against fraying. In this way, if bundles of fibers that are radially inward from the small holes by the wire are performed at a plurality of locations along the ring of the edging ring, the fibers extend to the radially inner periphery along the periphery of the through hole. The holding | maintenance with respect to the fraying of the fiber to make can be strengthened more.

  The rim ring is formed by cutting from a cylindrical body including fibers and a resin extending along the ring and having a length of multiple times or more than the rim ring thickness, and the rim ring has a radial direction. When small holes are formed that cross the middle part of the width, if the small holes are formed at the time of the cylindrical body before cutting out the edging ring, small holes are efficiently formed in many edging rings. can do. In this case, the cylindrical body is first formed with a cylindrical portion radially inward from the small hole, and then a rod-shaped body is installed in a portion to be the small hole, and is located radially outward from the small hole from above. If the cylindrical portion is formed, and then the rod-shaped body is removed to form the cylindrical body including the gap that becomes the small hole, the small holes can be formed more efficiently for the large number of edging rings.

  When the resin of the fiber reinforced resin sheet is in a state in which the resin of the fiber reinforced resin sheet can flow, the cone whose cross section expands from the pointed end of the enlarged through hole to the cross-sectional contour of the enlarged through hole starts from the tip to the fiber reinforced resin sheet. If formed by penetrating, it is possible to easily achieve an enlarged through hole in which a desired through hole is enlarged by a predetermined annular band in the fiber reinforced resin sheet.

  First, with reference to FIGS. 1-6, preparation of the edging ring used for the method of forming a through-hole in the fiber reinforced resin sheet by this invention is demonstrated in one embodiment.

  In FIG. 1, reference numeral 10 denotes a cylindrical body that is rotationally driven in the direction indicated by an arrow 14 around an axis 12 by a rotational drive mechanism not shown in the drawing. A groove 16 is cut radially in the cylindrical body 10 along one generatrix, and a plurality of fibers 18 are fixed in a state where the distal end is fixed to the cylindrical body by being inserted into the groove. Are arranged in parallel, the cylinders are rotationally driven in the direction indicated by the arrow 14 while these fibers are kept in a tensioned state with appropriate tension applied, and the parallel fibers are layered around the cylinders 10. It is rolled up.

  When the thickness of the wound fiber layer 20 reaches a predetermined value as shown in FIG. 2, the rotation of the cylindrical body 10 is temporarily stopped, and is just aligned with the outer peripheral surface of the fiber layer 20 formed so far. Using a tool 26 that holds the plurality of rod-like bodies 22 arranged in the annular position by the annular body 24, a rod-like shape is formed along the generatrix on the outer peripheral surface of the fiber layer 20 formed so far as shown in FIG. A body 22 is installed. In the illustrated example, the rod-like bodies 22 are twelve rod-like bodies arranged in an annular shape.

  Next, the rotation of the cylindrical body 10 is restarted, and the parallel fibers are further wound in layers on the fiber layer 20 and the rod-shaped body 22 as shown in FIG. When the thickness of the fiber layer 28 wound on the fiber layer 20 and the rod-like body 22 reaches a predetermined value, the rotation of the cylindrical body 10 is stopped, and the end of the portion of the parallel fibers wound as the fiber layer 28 is stopped. The part is held on the fiber layer 28 by an appropriate fixing means such as an adhesive tape, and the fibers after the terminal part are cut off. The polymer of the fiber layers 20 and 28 thus formed on the cylindrical body 10 is pulled out from the cylindrical body 10 while holding the tool 26, and is immersed in a molten resin layer as it is or a powdered resin. By being sprayed, it is a cylindrical body having a fiber reinforced resin layer structure in which fibers are embedded in the resin layer, and in any case after the resin layer is solidified, the tool 26 is pulled out from this, As shown in FIG. 5, an intermediate portion of the thickness of the cylindrical layer 30 includes fibers 18 arranged in parallel in a direction along the circumference in a cylindrical layer 30 of resin integrally formed by joining the fiber layers 20 and 28. A cylindrical body 34 having small holes 32 penetrating along the cylindrical generatrix is obtained.

  Then, if this cylindrical body 34 is cut at every predetermined axial length, a plurality of ring-shaped objects are obtained at a time, as indicated by 36 in FIG. 6, which is penetrated by the fiber-reinforced resin sheet according to the present invention. It can be used as an edge ring used in the hole forming method. As is apparent from the manufacturing process shown in FIGS. 1 to 4, even when the cylindrical body 34 is cut into the shape of the rim ring 36, no cut occurs in any of the fibers 18, and the composite reinforcing structure of resin with fibers itself is The structure of the small hole 32 penetrating along the cylindrical generatrix at the middle part of the thickness of the cylindrical layer 30 is not changed.

  As shown in some examples in FIG. 7, the rim ring 36 is formed by a wire 38 in which the fibers 18 radially inward of the small holes 32 of the fibers extending along the cylindrical ring pass through the small holes 32. A bundled treatment is applied. The bundling of the fibers 18 radially inward from the small holes 32 by the wire 38 passing through the small holes 32 in this way is that the rim ring 36 is incorporated into an enlarged through hole formed in the fiber reinforced resin sheet in the manner described later. In FIG. 7, the rim ring 36 in a single state is bundled with the wire 38 in FIG. 7, but the fibers 18 radially inward from the small holes 32 are bundled. The treatment may be performed after the rim ring 36 is incorporated into the enlarged through hole formed in the fiber reinforced resin sheet.

  In the example shown in A of FIG. 7, fibers that are radially inward from the small holes are bundled in the vicinity of each small hole by a wire 38 that passes through each small hole 32. In the example shown in FIG. 7B, fibers that are radially inward of the small holes are bundled between the adjacent small holes by the wire 38 that sequentially passes through the small holes 32 that are adjacent in the circumferential direction. Further, in the examples shown in FIGS. 7C and 7D, fibers that are radially inward from the small holes are bundled in the manner shown in FIGS. Fibers that are radially outward from the small holes are also bundled in the vicinity of each small hole by a wire 38 that passes through each small hole 32. However, in these examples shown in FIGS. 7C and 7D, the treatment of bundling fibers radially outward from the small holes 32 is performed before the rim ring 36 is incorporated into the enlarged through-hole formed in the fiber-reinforced resin sheet. It can only be executed.

  FIG. 8 shows, in addition to the preparation of the edging ring shown in FIGS. 1 to 7, as a main step in the method of forming a through hole in a fiber reinforced resin sheet according to the present invention, the through hole is formed in the fiber reinforced resin sheet. FIG. 9 is a side view of a drilling cone and a fiber-reinforced resin sheet, showing a procedure for opening a hole, and FIG. 9 is a cross-sectional view of the drilling cone taken along line 9-9 in FIG. It is a figure which shows the surface of the fiber reinforced resin sheet located.

  In the illustrated example, the fiber reinforced resin sheet 40 is perpendicular to the fibers 42-1, 42-3, 42-5, 42-7, etc. arranged in parallel in the horizontal direction as seen in FIG. 9 includes fibers 42-2, 42-4, 42-6 and the like arranged in parallel in the vertical direction and a resin layer 44 filled between these fiber layers.

  The drilling cone 46 has a conical operating part 50 whose transverse section expands from the tip to the cross-sectional contour of the enlarged through hole 48 to be opened in the fiber reinforced resin sheet 40. Starting from the front end, it is pressed against the fiber reinforced resin sheet 40, and the fibers 42-1 to 42-7 etc. on both sides from the position where the front end abuts are separated into both sides to penetrate into and penetrate the fiber reinforced resin sheet. As shown in FIG. 8, the fiber-reinforced resin sheet 40 is driven downward. The enlarged through-hole 48 is a through-hole having a diameter corresponding to the outer diameter of the rim ring for incorporating the rim ring 36, and at the periphery of the through-hole 52 to be formed as a product in the fiber reinforced resin sheet 40. A through-hole enlarged along the annular zone having a width corresponding to the radial width of the edging ring. Although not shown in FIGS. 8 and 9, the fiber reinforced resin sheet 40 is placed on a support base having an appropriate hole for receiving the cone 46.

  FIG. 10 shows a state in which the cone 46 is penetrated through the fiber reinforced resin sheet 40 to the final molding position and the through holes 48 are formed in the fiber reinforced resin sheet 40 in the manner described above. It is the top view shown in the upper surface about the fiber reinforced resin sheet 40 in the cross section.

  Whether the resin is a thermoplastic resin or a thermosetting resin, after the state in which the resin is solidified is obtained as shown in FIG. An edge ring 36 prepared as illustrated in FIG. 7 is incorporated in the enlarged through hole 48 that has been extracted and formed. FIG. 11 is a plan view of the fiber reinforced resin sheet 40 after the formation of the through hole showing an example in which the edge ring shown in FIG. 7A is used as the edge ring 36, and FIG. 12 is a cross section passing through the center of the through hole. FIG. If the resin of the fiber reinforced resin sheet 40 and the resin of the edging ring are heat-meltable resins, the fiber reinforced resin sheet in which the edging ring is incorporated as shown in the drawing, in particular, the incorporated part of the edging ring is heated to an appropriate temperature. By doing so, the resin of the fiber reinforced resin sheet and the resin of the rim ring can be fused at least at the joint portion, and the rim ring can be firmly fixed to the fiber reinforced resin sheet by the fusion between the resin layers.

  While the present invention has been described in detail with respect to several embodiments thereof, it will be apparent to those skilled in the art that various modifications can be made to these embodiments within the scope of the present invention. .

The perspective view which shows one embodiment which prepares the edging ring used for the method of forming a through-hole in the fiber reinforced resin sheet | seat by this invention in the 1st step. The perspective view which shows the 2nd step following FIG. The perspective view which shows the 3rd step following FIG. FIG. 4 is a perspective view showing a fourth stage following FIG. 3. The perspective view which shows the composite cylinder body of the fiber and resin obtained through said 1st-4th step. The perspective view which shows the state from which the annular body used as an edge ring was cut out from the composite cylindrical body of the fiber and resin shown in FIG. The perspective view which shows the example in which the bundling process by the wire which passes a small hole was given to the annular body used as an edging ring. 1 is a side view of a hole-forming cone and a fiber-reinforced resin sheet showing an embodiment of a method for forming a through-hole in a fiber-reinforced resin sheet in a method for forming a through-hole in a fiber-reinforced resin sheet according to the present invention. The figure which shows the surface of the fiber reinforced resin sheet | seat located in the cross section of the cone for a hole drilling by the line 9-9 of FIG. The cone 46 is penetrated through the fiber reinforced resin sheet 40 to its final molding position, and the through hole 48 is formed in the fiber reinforced resin sheet 40. FIG. The top view of the fiber reinforced resin sheet 40 after the through-hole formation which shows the example in which the edging ring shown to A of FIG. Sectional drawing which passes along the through-hole center part of the fiber reinforced resin sheet 40 after the through-hole formation shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Cylindrical body, 12 ... Axis, 14 ... Arrow, 16 ... Groove, 18 ... Fiber, 20 ... Fiber layer, 22 ... Rod-shaped body, 24 ... Ring body, 26 ... Tool, 28 ... Fiber layer, 30 ... Cylindrical layer, 32 ... Small hole, 34 ... Cylindrical body, 36 ... Border ring, 38 ... Wire rod, 40 ... Fiber reinforced resin sheet, 42-1 to 42-7 ... Fiber, 44 ... Resin layer, 46 ... Cone for drilling, 48 ... Expanded through hole, 50 ... Conical working part, 52 ... Through hole to be formed as a product in the fiber reinforced resin sheet 40

Claims (8)

  By forming a through hole in a fiber reinforced resin sheet, the through hole is formed by scraping around the fiber and resin present in the annular zone along the peripheral portion of the fiber reinforced resin sheet. An enlarged through-hole that is enlarged by the annular zone is formed, and an edge ring made of a fiber and a resin extending along the ring of the annular zone is incorporated into the annular zone of the enlarged through-hole. how to.   2. The method according to claim 1, wherein the rim ring is fixed to the fiber reinforced resin sheet in the enlarged through hole by fusing the resin of the fiber reinforced resin sheet and the resin of the rim ring. 3. .   The said rim ring is formed by cutting out from a cylindrical body containing fibers and resin extending along the ring and having a length of multiple times or more than the thickness of the rim ring. The method according to 1 or 2.   A small hole is formed in the edging ring across an intermediate portion of the radial width, and a fiber radially inward of the small hole among fibers extending along the ring of the annular zone has the small hole. The method according to any one of claims 1 to 3, wherein the method is bundled by passing wires.   5. The method according to claim 4, wherein the bundle of fibers located radially inward from the small hole by the wire is performed at a plurality of locations along the ring of the edging ring.   A small hole is formed in the rim ring so as to cross an intermediate portion of the radial width thereof, and the small hole is formed at a time when the rim ring is in a state of the cylindrical body before the rim ring is cut out. The method of claim 3.   In the cylindrical body, a cylindrical portion that is radially inward from the small hole is first formed, and then a rod-shaped body is installed in a portion that is to become the small hole, and is located radially outward from the small hole from above. The method according to claim 6, wherein a cylindrical portion is formed, and then the rod-shaped body is removed to form a cylindrical body including a space that becomes the small hole.   The fiber-reinforced resin sheet starts from the tip when the resin of the fiber-reinforced resin sheet is in a state where the resin can flow through a cone whose cross section expands from the sharp tip to the cross-sectional contour of the enlarged through-hole. The method according to claim 1, wherein the method is formed by penetrating the substrate.

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