JP2007231999A - Frp joining structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide FRP (fiber reinforced plastics) joining structure capable of exhibiting enhanced joining strength and excellent in productivity. <P>SOLUTION: This FRP joining structure 2A is provided with a plurality of members (left and right half bodies 3a and 3b) mutually overlapped and including at least one FRP member, an adhesive 4 interposed between the members (left and right half bodies 3a and 3b), and a tapping screw 6 screwed into the plurality of the overlapped members (left and right half bodies 3a and 3b). The tapping screw 6 is screwed in the state wherein the adhesive 4 is uncured. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an FRP joining structure between a FRP (Fiber Reinforced Plastics) member and a predetermined member.

Conventionally, as an FRP joining structure between an FRP member and a predetermined member (a member made of an FRP member or other material (metal or the like)), a structure in which the FRP member and the predetermined member are bonded via an adhesive is known. (For example, refer to Patent Document 1). In this FRP bonding structure, an adhesive is applied to the bonded portion of the members and the members are bonded together, and then the members are fixed using a jig until the adhesive is cured or semi-cured. Obtained by.
As another FRP joining structure, a structure using a fastener such as a bolt is known (for example, see Patent Document 2). This FRP joining structure is obtained by forming a pilot hole in the FRP member in advance and then joining the FRP member and a predetermined member via a fastener inserted through the pilot hole.
US Pat. No. 4,786,343 JP-A-5-77322

  However, in the conventional FRP joint structure using only an adhesive, when a crack occurs in the adhesive layer or between the layers of the FRP member itself, the crack is likely to propagate in these layers or between the layers, resulting in poor joint strength. It will be enough. And this FRP joining structure requires fixing of the member with a jig until the adhesive is at least semi-cured in the manufacturing process. That is, this FRP joint structure cannot be transferred to the next process while being restrained by the jig.

  On the other hand, the conventional FRP joint structure using a fastener such as a bolt (hereinafter also referred to as “conventional FRP joint structure using a bolt or the like”) is different from the conventional FRP joint structure using only an adhesive, Since it does not require time to be restrained by the jig, the productivity is improved. However, the plurality of pilot holes that are normally formed in the FRP member are often clearance holes (buck holes) in order to absorb variations (displacement) in the joining position with respect to a predetermined member joined to the FRP member. When the prepared hole is a clearance hole in this way, the contact area between the FRP member and the predetermined member at the joint portion is reduced, so that the joint strength is lowered.

  Then, this invention makes it a subject to provide the FRP joining structure which was excellent in productivity while exhibiting the outstanding joining strength.

  The present invention that solves the above-described problems includes a plurality of members including at least one FRP member that are overlapped with each other, an adhesive that is interposed between the adjacent members, and the plurality of members that are overlapped with each other. A tapping screw comprising a tapping screw screwed into the tapping screw, wherein the tapping screw is screwed in an uncured state of the adhesive.

  In the FRP joining structure of the present invention, a plurality of members stacked with an adhesive are fastened with a tapping screw. As a result, this FRP joint structure is different from the conventional FRP joint structure using only the adhesive, and it is not necessary to fix the members until the adhesive is cured or semi-cured, so a jig is required. And not.

  Further, in this FRP joining structure, since a plurality of members are fastened with tapping screws, even if cracks occur in the adhesive layer or between the layers of the FRP member itself, the tapping screws propagate the cracks. Hold back.

  Further, in this FRP joining structure, the tapping screw is screwed in while cutting a plurality of overlapped members, so that unlike the conventional joining structure using bolts or the like, the FRP member has a pilot hole. No processing is required.

  In addition, unlike the conventional FRP joint structure using bolts or the like, this FRP joint structure does not need to provide a clearance hole (buck hole) in the FRP member to absorb the variation (displacement) of the joint position. The contact area between the FRP member and the predetermined member at the joint portion is not reduced.

  Further, in such an FRP joint structure, the tapping screw is screwed in an uncured state of the adhesive, and therefore, when the tapping screw is screwed, the adhesive is accompanied with the screw portion. As a result, an adhesive is interposed between the screw portion of the tapping screw and the member.

  In such an FRP bonding structure, it is desirable that the screw portion of the tapping screw and the member are bonded via the adhesive attached to the screw portion.

  Moreover, in such an FRP joining structure, it can comprise so that the screwing part of the said tapping screw in the said FRP member may become thin.

  In addition, the manufacturing method of such an FRP joint structure includes a first step in which a plurality of members including at least one FRP member are overlapped via an adhesive, and the tapping screw is in an uncured state of the adhesive. And a second step of being screwed into the plurality of superimposed members.

  Unlike the conventional FRP joining structure which uses only an adhesive agent, the FRP joining structure of the present invention does not require the use of a jig in its manufacturing process, so that its productivity can be improved.

  Further, the FRP joint structure of the present invention is a conventional FRP joint using only an adhesive because the tapping screw stops the propagation of cracks even when a crack occurs in the adhesive layer or between the layers of the FRP member itself. Excellent bonding strength can be achieved compared to the structure.

  In addition, unlike the conventional FRP joint structure using bolts or the like, the FRP joint structure of the present invention exhibits excellent joint strength because the contact area between the FRP member and the predetermined member in the joint portion is not reduced. can do.

  Moreover, this FRP joining structure can prevent the tapping screw from loosening by joining the threaded portion of the tapping screw and the member with an adhesive.

  Moreover, this FRP joining structure can improve the airtightness and watertightness between a thread part and a member by interposing an adhesive agent between the thread part and member of a tapping screw.

  In addition, this FRP joining structure is a member or a tapping screw when the member is formed of a material that generates a potential difference with the tapping screw by interposing an adhesive between the screw portion of the tapping screw and the member. It is possible to more reliably prevent local current corrosion.

  Moreover, this FRP joining structure can make it easy to screw the tapping screw into the FRP member by making the screwed portion of the tapping screw in the FRP member thin.

Next, the FRP bonding structure according to the embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is a perspective view of a small aircraft to which the FRP joining structure according to the embodiment is applied, and is a view including a notch in a part. 2A is a partially enlarged view of the AA cross section of FIG. 1, and FIG. 2B is an enlarged view of a B portion of FIG. 2A.
Here, the body of a small aircraft to which the FRP joining structure according to the embodiment is applied will be described first.

  As shown in FIG. 1, a body 1 of a small aircraft is formed by joining a right half 3a made of a CFRP (Carbon Fiber Reinforced Plastics) laminated member and a left half 3b to each other. Here, the left and right half bodies 3a and 3b correspond to “a plurality of members including the FRP member” in the claims.

  This CFRP laminated member is formed by laminating a plurality of layers containing carbon fibers and a curable resin, and carbon fibers are arranged on the surface of the mold having the outer shape of the body 1 so as to be oriented at a predetermined angle. And by curing the curable resin impregnated in the carbon fiber. Such a CFRP laminated member may be a cured prepreg disposed on the surface of the mold. The FRP joining structure according to the present embodiment to be described next is applied to joining the left and right halves 3a and 3b made of a CFRP laminated member constituting the body 1.

  As shown in FIG. 2A, the FRP joining structure 2A includes a right half 3a and a left half 3b that form a body 1 (see FIG. 1) of a small aircraft, and a left and right half 3a that are superimposed on each other. , 3b and an adhesive 4 interposed between them and a tapping screw 6 screwed into the left and right halves 3a, 3b.

The adhesive 4 is preferably made of a thermosetting resin, and particularly preferably an epoxy adhesive.
The tapping screw 6 may have a known structure. For example, as shown in FIG. 2A, the tapping screw 6 includes a head portion 6a and a screw portion 6b in which a thread is engraved in a rod-like body portion. . As is well known, a groove 6c having a cutting blade is formed in the threaded portion 6b so as to be along the longitudinal direction of the threaded portion 6b.
As will be described later, the tapping screw 6 is screwed with the adhesive 4 in an uncured state. As shown in FIG. 2B, the adhesive 4a adheres to the screw portion 6b. ing. This adhesive 4a is accompanied by the adhesive 4 interposed between the left and right halves 3a and 3b when the tapping screw 6 is screwed into the left and right halves 3a and 3b (see FIG. 2A). And the layer which covers the thread part 6b is formed in the circumferential direction of the thread part 6b. And the screw part 6b and the left half 3b are joined via the adhesive agent 4a adhering to the screw part 6b.

Next, the effect of the FRP joining structure 2A according to the present embodiment will be described.
The FRP joining structure 2A shown in FIG. 2 has a conventional FRP joining structure using only an adhesive because the left and right halves 3a and 3b overlapped with the adhesive 4 are fastened with a tapping screw 6. Differently, the left and right halves 3a and 3b do not have to be fixed until the adhesive 4 is cured or semi-cured. Therefore, the FRP joining structure 2A does not require time to be restrained by a jig, and thus its productivity is improved. And since the FRP joining structure 2A is not restrained by a jig, the FRP joining structure 2A is immediately shifted to the next process for manufacturing the final product (small aircraft in this embodiment) to which the FRP joining structure 2A is applied. Can do. That is, the FRP joining structure 2A can also improve the productivity of the final product.

  On the other hand, the conventional FRP joining structure using only an adhesive is a combination of a plurality of sets of members (corresponding to the left and right halves 3a and 3b in the present embodiment) in an attempt to improve the productivity. Bonding must be done in parallel at the same time. In other words, in the conventional FRP joint structure, the more the productivity is increased, the more jigs are required, and the investment of manufacturing equipment increases. On the other hand, since the FRP joining structure 2A according to the present embodiment does not require a jig, the manufacturing cost can be reduced as compared with a conventional FRP joining structure using only an adhesive.

  Further, in the FRP joining structure 2A, since the left and right halves 3a and 3b are fastened by the tapping screw 6, the CFRP laminated member itself forming the adhesive 4 layer and the left and right halves 3a and 3b, respectively. Even when a crack occurs between the two layers, the tapping screw 6 stops the propagation of the crack. As a result, this FRP bonding structure 2A can exhibit a bonding strength superior to that of a conventional FRP bonding structure using only an adhesive.

  Moreover, in this FRP joining structure 2A, since the tapping screw 6 is screwed in while threading the overlapped left and right halves 3a, 3b, unlike the conventional joining structure using bolts, There is no need to drill a pilot hole in the FRP member. As a result, the FRP joint structure 2A can reduce man-hours in the manufacturing process, and thus can reduce productivity and manufacturing cost as compared with a conventional FRP joint structure using bolts or the like.

  Further, unlike the conventional FRP joint structure using bolts or the like, this FRP joint structure 2A is provided with clearance holes (buck holes) in the left and right halves 3a and 3b for absorbing variations (shifts) in the joint position. There is no need. As a result, in the FRP joining structure 2A, the contact area between the right half 3a and the left half 3b in the joined portion is not reduced. Therefore, this FRP joining structure 2A can exhibit superior joining strength as compared with a conventional FRP joining structure using bolts and the like because the adhesive force of the adhesive 4 works synergistically.

  Further, in this FRP joining structure 2A, the screw portion 6b of the tapping screw 6 and the left half 3b are joined by the adhesive 4a, so that the tapping screw 6 can be prevented from loosening.

  Further, in this FRP joining structure 2A, the adhesive 4a is interposed between the screw portion 6b of the tapping screw 6 and the left half 3b, so that airtightness and watertightness between the screw portion 6b and the left half 3b are present. Can be improved.

  In addition, since the adhesive 4a is interposed between the threaded portion 6b of the tapping screw 6 and the left half 3b in the FRP joining structure 2A, for example, the left half 3b made of a CFRP laminated member and the tapping screw 6 Even in an environment where a potential difference occurs between them and the metal forming the tapping screw 6 becomes base, it is possible to more reliably prevent local current corrosion of the tapping screw 6 from occurring.

Next, a method for manufacturing the FRP joint structure 2A according to this embodiment will be described.
In this manufacturing method, first, a CFRP laminated member is formed by a well-known procedure on the surface of a mold having the outer shape of a body 1 (see FIG. 1) of a small aircraft, whereby the right half 3a and the left half of the body 1 are formed. 3b (see FIG. 1) is produced. Then, as shown in FIG. 2A, the right half 3a and the left half 3b are superposed via the adhesive 4 (first step).

  Next, in this manufacturing method, as shown in FIG. 2A, the tapping screw 6 is screwed into the left and right half bodies 3a and 3b that are overlapped (second step). At this time, the tapping screw 6 is screwed with the adhesive 4 in an uncured state. When the tip of the screw portion 6b passes through the right half 3a and then passes through the layer of the adhesive 4 and is further screwed into the left half 3b, the adhesive 4 adheres to the screw portion 6b. , Accompanying the threaded portion 6b in the left half 3b while being taken into the groove 6c. As a result, the adhesive 4 spreads in the circumferential direction of the threaded portion 6b in the left half 3b. That is, as shown in FIG. 2B, the screw portion 6b is covered with a layer made of the adhesive 4a.

  According to such a manufacturing method of the FRP joining structure 2A, the tapping screw 6 screwed into the left and right halves 3a and 3b in an uncured state of the adhesive 4 fastens the left and right halves 3a and 3b. Even if the agent 4 is uncured, the left and right halves 3a and 3b do not deviate from each other. Therefore, in this manufacturing method, even if the adhesive 4 is in an uncured state, a jig for fixing the left and right halves 3a and 3b is not required, so the productivity of the FRP joining structure 2A can be improved. .

  Moreover, according to this manufacturing method, since the jig | tool is not required even if the adhesive agent 4 is in the uncured state, compared with the manufacturing method of the conventional FRP joining structure using only an adhesive agent, FRP joining The manufacturing cost of the structure 2A can be reduced.

  Further, according to this manufacturing method, the tapping screw 6 is used, and unlike the conventional FRP joint structure manufacturing method using bolts or the like, the bottom for inserting the bolts or the like into the left and right halves 3a and 3b. There is no need to drill holes. As a result, according to this manufacturing method, since the man-hours in the manufacturing process are reduced, the productivity and manufacturing cost of the FRP joint structure 2A are reduced as compared with the conventional method for manufacturing the FRP joint structure using bolts or the like. be able to.

  Further, according to this manufacturing method, unlike the conventional FRP bonding structure manufacturing method using bolts or the like, the clearance holes (buck holes) for absorbing the variation (displacement) of the bonding position are formed on the left and right half bodies 3a, Since it is not necessary to provide in 3b, the contact area of the right half 3a and the left half 3b in a junction part does not reduce. Therefore, according to this manufacturing method, it is possible to obtain the FRP bonding structure 2A that exhibits excellent bonding strength as compared with the conventional manufacturing method of the FRP bonding structure.

  Further, according to this manufacturing method, since the adhesive 4a can be interposed between the screw portion 6b of the tapping screw 6 and the left half 3b, the FRP joining structure 2A in which the tapping screw 6 is prevented from being loosened, It is possible to obtain an FRP joint structure 2A with improved airtightness and water tightness between the screw part 6b and the left half 3b and an FRP joint structure 2A in which local current corrosion of the tapping screw 6 is more reliably prevented.

In addition, this invention is implemented in various forms, without being limited to the said embodiment.
In the embodiment, the FRP joint structure 2A in which the two members of the right half body 3a and the left half body 3b, both of which are CFRP laminated members, are joined to each other is illustrated. However, the present invention has the following FRP joint structure. There may be. FIGS. 3A to 3C are cross-sectional views showing FRP joining structures according to other embodiments, respectively. In these other embodiments, the same reference numerals are given to the same components as those in the previous embodiment, and the detailed description thereof is omitted.

  As shown in FIG. 3A, the FRP joint structure 2B according to another embodiment includes a first member 8a, a second member 8b, and a first member 8b from the head 6a side of the tapping screw 6 toward the opposite side. The three members 8c are superposed in this order via the adhesive 4. And in this FRP joining structure 2B, at least any one member of the 1st member 8a, the 2nd member 8b, and the 3rd member 8c is formed with the CFRP laminated member. There is no restriction | limiting in particular as members other than the CFRP laminated member which forms this FRP joining structure 2B, For example, a metal member, a resin member, another organic member, or an inorganic member is mentioned. And although this FRP joining structure 2B is not shown in figure, the adhesive agent 4a (refer FIG.2 (b)) is between the screw part 6b and the 2nd member 8b, and between the screw part 6b and the 3rd member 8c. Intervene. In such an FRP joining structure 2B, when at least one of the second member 8b and the third member 8c is a metal, the effect of preventing the above-described local current corrosion of the present invention is remarkably exhibited.

  As shown in FIG. 3B, in the FRP joining structure 2C according to another embodiment, the first member 8a and the second member 8b are bonded from the head 6a side of the tapping screw 6 toward the opposite side. Overlaid in this order via the agent 4. In this FRP bonding structure 2B, the first member 8a is formed of a CFRP laminated member, and the second member 8b is formed of the above-described members other than the CFRP laminated member. The first member 8a formed of the CFRP laminated member has a thinned portion S of the tapping screw 6. Incidentally, although this FRP joining structure 2C is not shown in figure, the adhesive agent 4a (refer FIG.2 (b)) is interposing between the thread part 6b and the 2nd member 8b.

  In such an FRP joining structure 2C, since the screwed portion S is thin, the tapping screw 6 can be easily screwed into the first member 8a. Moreover, since the FRP joining structure 2C has a thin screwed portion S, the head portion 6a of the tapping screw 6 can be accommodated in a recess formed by the thin portion.

Further, according to the present invention, when both the first member 8a and the second member 8b are formed of a CFRP laminated member, as shown in FIG. 3C, the first member 8a and the second member The FRP joint structure 2D in which both screwed portions S of 8b are thin may be used. Although this FRP joining structure 2D is not shown in figure, the adhesive agent 4a (refer FIG.2 (b)) is interposing between the thread part 6b and the 2nd member 8b.
this

  In the FRP joining structure 2C shown in FIG. 3B, the present invention may be one in which the tapping screw 6 is screwed from the second member 8b side toward the screwed portion S of the first member 8a. In this case, although not shown, the adhesive 4a (see FIG. 2B) is interposed between the screw portion 6b and the first member 8a.

1 is a perspective view of a small aircraft to which an FRP joining structure according to an embodiment is applied. (A) is the elements on larger scale of the AA cross section of FIG. 1, (b) is the B section enlarged view of (a). (A) thru | or (c) is sectional drawing which shows the FRP joining structure which concerns on other embodiment.

Explanation of symbols

1 Body 2A FRP joint structure 2B FRP joint structure 2C FRP joint structure 2D FRP joint structure 3a Right half (FRP member)
3b Left half (FRP member)
4 Adhesive 4a Adhesive 6b Threaded portion 8a First member 8b Second member 8c Third member S Screwed portion

Claims (3)

A plurality of members, including at least one FRP member, superimposed on each other;
An adhesive interposed between the adjacent members;
A tapping screw screwed into the plurality of superimposed members;
FRP joining structure comprising
The tapping screw is an FRP joint structure in which the adhesive is screwed in an uncured state.   2. The FRP joint structure according to claim 1, wherein a screw portion of the tapping screw and the member are joined via the adhesive attached to the screw portion.   The FRP joint structure according to claim 1 or 2, wherein a screwed portion of the tapping screw in the FRP member is thin.

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