Fasteners and fastening structures

Abstract

To prevent a gap from being formed between a hole edge located at the insertion tip side of a shank part in a hole of an object to be fastened (a fastened object) and the shank part when the shank part forming a grommet body buckles.SOLUTION: In a fastener, a predetermined length of a shaft body 1 is pulled out from a grommet body 2 after a shank part 15 of the grommet body 2 is inserted into a hole Pa of a fastened object P to cause at least a part of the shank part 15 to buckle so that the part separates from a center axis x between a base part 17 at a head part 12 side and a terminal part 18 opposite to the base part 17, and, through the process, the fastened object P is sandwiched between the head part 12 and the shank part 15 to be fastened. Parts of an outer surface of the shank part 15 are formed as inclined surfaces 19 each of which continues in a direction along the center axis x and gradually increases a distance from the center axis x toward the terminal part 18 side. Further, a thickness 20 of the shank part 15 gradually increases toward the terminal part 18 side in formation areas of the inclined surfaces 19.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] This invention relates to an improvement to a fastener comprising a shaft body and a grommet body containing a part of the shaft body, and configured so that when the grommet body is inserted into a hole in an object to be fastened and then the shaft body is removed, buckling occurs in the grommet body on the insertion side, thereby clamping the object to be fastened between the head of the grommet body and the buckled point and fastening it to the object. [Background technology]

[0002] Patent Document 1 discloses a blind rivet consisting of a rivet sleeve and a pin.

[0003] In Patent Document 1, after inserting a rivet sleeve into a hole in an object to be fastened, when the pin is pulled out from inside the rivet sleeve, the shank of the rivet sleeve buckles, thereby clamping the object to be fastened between the head of the rivet sleeve and the buckled point. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2014-530327 Summary of the Invention [Problem to be solved by the invention]

[0005] If a gap is created between the shank of the rivet sleeve and the edge of the hole into which the shank is inserted during the buckling process, i.e., during clamping, then, for example, when two panels are being fastened, the fastener can prevent the two panels from separating, but it cannot prevent the panels from moving within the gap in a direction perpendicular to the central axis of the rivet sleeve or the fastener from moving within the hole, i.e., it cannot prevent rattle. Such rattle can cause abnormal noise when this type of fastener is used to fasten two parts of an automobile, for example.

[0006] The main problem that this invention aims to solve is that when this type of fastener is buckled as described above, a gap should be minimized between the buckled body that constitutes the grommet body described below and the edge of the hole that is positioned on the insertion side of the body in the hole to be fastened, in a direction perpendicular to the central axis of the body. [Means for solving the problem]

[0007] In order to achieve the above object, in this invention, a fastener is A shaft body, a grommet body having a head and a body, the shaft being opened at the head and housed in a housing portion extending along the central axis of the body with a portion of the shaft protruding outward from the opening, A fastener that fastens to an object by inserting a body portion of the grommet body into a hole of the object to be fastened and then using a part of the shaft body to extract a required amount of the shaft body from the grommet body, thereby buckling at least a part of the body body between a base portion on the head side and an end portion opposite thereto so as to move away from the central axis, thereby sandwiching the object to be fastened between the head and the body portion, A part of the outer surface of the body is made into an inclined surface that continues in a direction along the central axis and the distance from the central axis gradually increases as it approaches the terminal portion side, and the thickness of the body within the range of the inclined surface gradually increases as it approaches the terminal portion side.

[0008] Depending on the direction of the inclination of the inclined surface, the thickness of the body at the inclined surface facing the hole edge located on the insertion side of the body can be made thinner than the thickness of the body located closer to the terminal end, so that during buckling, this point is always weaker than positions closer to the buckling center and is more likely to bend due to the force acting on the body when the shaft is extracted, thereby preventing, as much as possible, the base side of the body from bending at a position biased toward the buckling center from this point during buckling. This allows the base side of the body to bend around the inclined surface, with the inclined surface always pressed against the hole edge located on the insertion side of the body when the body buckles. As a result, it is possible to prevent a gap perpendicular to the central axis from occurring between the buckled body and the hole edge located on the insertion side of the hole to be fastened.

[0009] One aspect of this invention is to form the inclined surface so that when the body part is inserted into the hole to be fastened, one of the points on the inclined surface faces the edge of the hole on the insertion side of the hole.

[0010] In one aspect of the present invention, the inclined surface is formed of a flat surface.

[0011] In one aspect of the present invention, at least a portion of the inclined surface is configured so that its width gradually decreases as it approaches the terminal portion.

[0012] In one aspect of the present invention, a thin hinge portion that is bent when the body buckles is formed between the inclined surface and the end portion of the body.

[0013] In addition, one aspect of the present invention is that the trunk portion is formed by integrating two or more trunk portion constituent bodies with the base portion and the terminal portion, respectively, so that the storage portion is formed inside these bodies.

[0014] In addition, one aspect of the present invention is that the trunk is constructed from two of the trunk constituents, an opening is formed between the two trunk constituents in a direction along the central axis, and a convex portion that protrudes toward the terminal portion is formed on an opening edge on the base side of the opening. [Effects of the Invention]

[0015] According to this invention, when the fastener is buckled as described above, the fastening state of the fastener can be controlled so that a gap perpendicular to the central axis of the body is minimized between the body constituting the buckled grommet body and the hole edge located on the insertion side of the body in the hole to be fastened. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view of a fastener according to one embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing the fastener as viewed from a different direction than in FIG. [Figure 3] FIG. 3 is a perspective cutaway view of a main part of the fastener. [Figure 4] FIG. 4 is a side view of the fastener, with the fastening object shown in imaginary lines. [Figure 5] FIG. 5 is a side view of the fastener in a state where the body of the grommet body is buckled and fastened to a fastening object. [Figure 6] FIG. 6 is a side view of the fastener in a state where the body of the grommet body is buckled and fastened to the fastening object, showing the state when the thickness of the fastening object is thinner than the fastening object shown in FIG. [Figure 7] FIG. 7 is a perspective cutaway view of a main part of the fastener when buckled. [Figure 8] FIG. 8 is a cross-sectional view taken along line DD in FIG. [Figure 9] FIG. 9 is an enlarged view of the portion F in FIG. [Figure 10] FIG. 10 is a cross-sectional view taken along line AA in FIG. [Figure 11] FIG. 11 is a cross-sectional view taken along line BB in FIG. [Figure 12] FIG. 12 is a cross-sectional view taken along line CC in FIG. [Figure 13] FIG. 13 is a plan view of the fastener. [Figure 14] FIG. 14 is a cross-sectional view taken along line EE in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] A typical embodiment of the present invention will be described below with reference to Figures 1 to 13. The fastener according to this embodiment has the function of inserting the fastening device into a hole Pa of a fastening object P, and then extracting a shaft body 1 (described later) by a predetermined amount from within a grommet body 2 (described later), thereby buckling a body portion 15 of the grommet body 2 and clamping the fastening object P between a portion of the body portion 15 that has been enlarged and deformed by the buckling and a head portion 12 (described later).

[0018] Such fasteners are typically used to unite two or more fastening objects P together via the fastener. Specifically, two or more fastening objects P are stacked on top of each other so that the holes Pa of the two or more fastening objects P are connected, and then the body 15 of the grommet is inserted into the holes Pa, and the body 15 is buckled at the insertion end, thereby sandwiching the two or more fastening objects P between the head 12 and the body 15 and integrating them via the fastener. In this sense, this fastener is a substitute for a rivet. In addition, unlike a rivet, the operation of extracting the shaft body 1 from the grommet body 2 causes buckling of the body 15, which is equivalent to the crimping of a rivet, and has the advantage that the fastening operation to the object P can be completed by operating only from one side of the object P. For these reasons, this fastener is also called a blind rivet.

[0019] Such a fastener is composed of a shaft body 1 and a grommet body 2. If the grommet body 2 is made of synthetic resin, the buckling occurs during the extraction operation, and the fastening object P can be elastically clamped between the shaft body 1 and the head 12 without any rattle. When both the shaft body 1 and the grommet body 2 are made of synthetic resin, the fastener can be molded by two-color molding.

[0020] In the illustrated example, the fastener is constructed by molding the shaft body 1 from synthetic resin, and then positioning a portion of the shaft body 1 within the trunk portion 15, and molding the grommet body 2 from synthetic resin. The internal shape of the body 15 of the grommet body 2 is complementary to the external shape of the shaft body 1 at the location where a portion of the shaft body 1 is located.

[0021] The grommet body 2 has a head 12 and a body 15, and the shaft body 1 is opened at the head 12 and accommodated in a storage section 16 that continues along the central axis x of the body 15, with a portion of the shaft body 1 protruding outward from the open section.

[0022] The fastener of this embodiment is configured so that the body 15 of the grommet body 2 is inserted into the hole Pa of the object P to be fastened, and then a part of the shaft 1 (in the illustrated example, the head portion 5 described below) is used to extract the required amount of shaft 1 from within the grommet body 2, causing at least a part of the body 15 to buckle between the base 17 on the head 12 side and the terminal portion 18 opposite it so as to move away from the central axis x, thereby clamping the object P to be fastened between the head 12 and the body 15 and fastening it to the object P to be fastened.

[0023] In addition, a portion of the outer surface of the body 15 is configured with an inclined surface 19 that continues in a direction along the central axis x and whose distance from the central axis x gradually increases as it approaches the terminal portion 18. The body 15 is thinner in the area where the inclined surface 19 is formed than in the surrounding area. At the same time, the wall thickness 20 (see Figures 9, 11, and 12) of the body 15 in the area where the inclined surface 19 is formed gradually increases as it approaches the terminal portion 18, in other words, as it moves away from the head 12.

[0024] That is, when the body 15 is inserted into the hole Pa of the fastening object P, the inclined surface 19, which faces one of the points 29 (see Figure 4) toward the hole edge Pb on the insertion side of the body 15, has a length extending along the central axis x and a width perpendicular to this central axis x.

[0025] Furthermore, the inclined surface 19 is formed so that when the body portion 15 is inserted into the hole Pa of the fastening object P, one of the points 29 of the inclined surface 19 faces the hole edge Pb on the insertion side of the hole in a direction perpendicular to the central axis x (Figure 4).

[0026] The location 29 of the inclined surface 19 that faces (is at the same level in the direction of the central axis x) the hole edge Pb located on the insertion side of the body 15 in the hole Pa of the fastening object P changes depending on the thickness of the fastening object P. The greater the thickness, the closer the location 29 is to the terminal portion 18 of the body 15, and the smaller the thickness, the closer the location 29 is to the base portion 17 of the body 15.

[0027] In this embodiment, the shaft body 1 is configured to include a rod-shaped main body 3, an anchor portion 4 formed at one end 3a of the rod-shaped main body 3, and a head portion 5 formed at the other end 3b of the rod-shaped main body 3.

[0028] The rod-shaped main body 3 is configured so that the cross section perpendicular to its central axis y (see FIG. 8, which coincides with the central axis x of the body 15 in the illustrated example) is substantially circular at any position.

[0029] The anchor portion 4 is configured to have a length, and is formed so that its length direction (the left-right direction in FIG. 8) is perpendicular to the central axis y of the rod-shaped main body 3. The length of the anchor portion 4 is greater than the diameter of the rod-shaped main body 3. At a position midway in the length direction of the anchor portion 4, one end portion 3a of the rod-shaped main body 3 is integrated with the anchor portion 4 so that hook portions 6 protruding in a direction perpendicular to the central axis y of the rod-shaped main body 3 are formed on both sides of the central axis y of the rod-shaped main body 3 by the anchor portion 4.

[0030] The head portion 5 is also configured to have a length, and is formed so that its length direction (the left-right direction in FIG. 8) is perpendicular to the central axis y of the rod-shaped main body 3. The length of the head portion 5 is greater than the diameter of the rod-shaped main body 3, and is also greater than the length of the anchor portion 4. The other end portion 3b of the rod-shaped main body 3 is integrated with the head portion 5 at a position midway in the length direction so that jaw portions 7 are formed by the head portion 5 on both sides of the central axis y of the rod-shaped main body 3.

[0031] The rod-shaped main body 3 is formed with a plurality of circumferential ridges 8 in a direction along the central axis x, so as to form a multi-stage structure as a whole. Each of the circumferential ridges 8 has an engagement surface 8a facing the anchor portion 4 and a tapered surface 8b facing the head portion 5. The tapered surface 8b of each of the circumferential ridges 8 is inclined in a direction that reduces the amount of protrusion of the circumferential ridge 8 toward the head portion 5. The engagement surface 8a of each of the circumferential ridges 8 is a surface that is perpendicular to the central axis x. In the illustrated example, the rod-shaped main body 3 has a large diameter portion 9 extending from the head portion 5 to the point where it enters the head portion 12 of the grommet body 2, and a small diameter portion 10 extending between the large diameter portion 9 and the anchor portion 4. A circumferential stepped surface 11 facing the anchor portion 4 is formed between the large diameter portion 9 and the small diameter portion 10. The diameter of the thin-diameter portion 10 at the ridge 8c of each circumferential ridge 8, i.e., the ridge 8c where the engagement surface 8a and the tapered surface 8b meet, is substantially equal to the diameter of the thick-diameter portion 9, but the diameter of the thin-diameter portion 10 at the valley 8d where one tapered surface 8b of adjacent circumferential ridges 8 meets the other engagement surface 8a in the direction along the central axis x is smaller than the diameter of the thick-diameter portion 9.

[0032] In the illustrated example, the grommet body 2 comprises a disk-shaped head 12 and a body 15 that is integrated with the head 12 and protrudes from the center of one face of the head 12 in a direction perpendicular to the face. The part of the body 15 that is integrated with the head 12 is the base 17 of the body 15 , and the end of the body 15 opposite to this base 17 is the terminal part 18 of the body 15 . Head 12 has an outer diameter that prevents it from entering hole Pa in object P. On the other hand, body 15 has a thickness that allows it to be inserted into hole Pa in object P, and when body 15 is fully inserted into the hole, end 18 of body 15 protrudes a certain distance beyond hole edge Pb on the insertion side (FIG. 4). In this embodiment, the outer surface 22 (outer side surface) located between the base 17 and the terminal portion 18 of the body 15, other than the inclined surface 19 and the hinge portion 25 described below, is formed to follow the surface of an imaginary cylinder (not shown) (see Figures 1 and 2). The inclined surface 19 has an appearance such that a portion of the imaginary cylinder has been shaved off in the direction along its length, and is therefore located closer to the central axis x than the surface of the imaginary cylinder.

[0033] In addition, the terminal portion 18 is formed so as to position the anchor portion 4 of the shaft 1 between it and the trunk portion 15, and the outer surface of the terminal portion 18 is a hemispherical surface 21 with its apex positioned on the central axis x.

[0034] The shaft body 1 and grommet body 2 are integrated as follows: In the illustrated example, the previously molded shaft body 1 is positioned in a molding die (not shown), and the synthetic resin that makes up the grommet body 2 is then fed into the die to form the grommet body 2; in the area where the shaft body 1 and grommet body 2 come into contact, the outer shape of the shaft body 1 and the internal shape of the grommet body 2 are complementary shapes. (1) The anchor portion 4 of the shaft body 1 is built into the terminal portion 18 side of the grommet body 2. In the illustrated example, the protruding end face 4a of the anchor portion 4 is exposed on the terminal portion 18 side so as to be flush with the outer surface 22 of the body portion 15, but the rest of the anchor portion 4 other than the protruding end face 4a is covered by the body portion 15 and the terminal portion 18, and the body portion 15 is provided with a hooked portion 23 for the hook portion 6. (2) The head portion 5 of the shaft body 1 is located outside the grommet body 2 . (3) The large diameter portion 9 of the shaft body 1 is positioned such that the circumferential stepped surface 11 side is inside the head portion 12 of the grommet body 2. The head portion 12 is formed with a through hole 13 having a hole diameter equal to the outer diameter of the large diameter portion 9 and a circumferential engaged surface 14 corresponding to the circumferential stepped surface 11. (4) The small diameter portion 10 of the shaft body 1 is positioned within the body portion 15 of the grommet body 2. As a result, within the body portion 15 of the grommet body 2, recesses 24 corresponding to the multi-stage circumferential protrusion 8 are formed in a multi-stage pattern.

[0035] The inclined surface 19 forms a part of the outer surface 22 of the body 15. The inclined surface 19 is formed at a location between the base 17 and the terminal end 18 of the body 15.

[0036] In this embodiment, the inclined surface 19 is formed of a flat surface, and at least a part of the inclined surface 19 gradually decreases in width as it approaches the terminal portion 18. In other words, the inclined surface 19 is inclined with respect to the central axis x, but is a flat surface without any curvature.

[0037] In the illustrated example, the inclined surface 19 is formed in a range from the starting end on the base 17 side, indicated by reference numeral 19a in Fig. 2, to the end at a position midway in the length direction of the body 15, indicated by reference numeral 19b. A step 19c is formed between the starting end 19a and the base 17. In the illustrated example, the width of the inclined surface 19 is constant from the starting end 19a to a position 19d midway along the entire length of the inclined surface 19, but gradually decreases from this midway position 19d to the end 19b as it approaches the end 19b (Fig. 2). The thick-diameter portion 9 of the shaft 1 and the circumferential protrusion 8 Passing through ridge 8c The thickness 20 of the body 15, which is the distance between a line segment L1 (see Figure 9) parallel to the central axis x and the inclined surface 19 (the imaginary line segment that the inclined surface 19 follows is shown as L2 in Figure 9), and in the illustrated example, the thicknesses 20 (see Figure 9) of the two body 15 components described below each become thicker as they approach the end 19b of the inclined surface 19 (the lower side in Figure 9).

[0038] Furthermore, a thin hinge portion 25 is formed between the inclined surface 19 and the terminal portion 18 of the body portion 15, and is bent when the body portion 15 buckles. In the illustrated example, a recess with an elliptical outline is formed between the end 19b of the inclined surface 19 and the protruding end face 4a of the exposed anchor portion 4, and this recess forms the hinge portion 25.

[0039] In this embodiment, the trunk portion 15 is configured by integrating two or more trunk portion constituent bodies 30 with the base portions 17 and the terminal portions 18, respectively, so that the storage portion 16 is formed inside these bodies.

[0040] In the illustrated example, the trunk 15 is configured from two trunk constituents 30, and an opening 26 is formed between the two trunk constituents 30 in the direction along the central axis x and in the shape of a window for the storage section 16, and a protrusion 27 that protrudes toward the terminal section 18 is formed on the opening edge of the opening 26 on the base 17 side. Due to this convex portion 27, during the buckling, the stress generated by the bending of one of the two body constituents 30 on the base 17 side and the stress generated by the bending of the other of the two body constituents 30 on the base 17 side can be dispersed to both sides of the convex portion 27, without being concentrated at the center of the opening edge of the opening 26 on the base 17 side. In the illustrated example, it is reasonable to design the mold so that the head portion 5 side of the shaft body 1 is the gate side of the resin that constitutes it, and the terminal portion 18 side of the grommet body 2 is the gate side of the resin that constitutes it, and in this way, the weld line is located where the protrusion 27 is formed. Therefore, the protrusion 27 avoids stress concentration at the weld line, and makes it possible to prevent the body portion 15 from breaking at the weld line during buckling as much as possible. When the mold is designed as described above, the protrusion 27 becomes a pool of resin above the weld line inside the mold.

[0041] In the illustrated example, the openings 26 are formed on both sides of the body 15 in the diametric direction across the central axis x. The opening edge of the opening 26 on the base 17 side is at substantially the same level as the starting end 19 a of the inclined surface 19 , and the opening edge of the opening 26 on the terminal end 18 side is at substantially the same level as the hinge portion 25 . The opening edges of the opening 26 along the length of the body 15 are substantially parallel to the central axis x, and the width of the opening 26 is constant between the left and right opening edges. In the area where the opening 26 is formed, the shaft 1 is exposed. The widths of the two openings 26 in the direction orbiting the central axis x are equal, and therefore the widths of the two trunk constituent bodies 30 in the same direction are also equal.

[0042] As a result, in this embodiment, the two trunk constituent bodies 30 are configured such that the base portion 17 and the terminal portion 18 are integrated together, respectively, so that the storage portion 16 is formed inside them.

[0043] Although not shown in the figures, if three openings 26 are formed in the trunk portion 15 at intervals in the direction circumferentially around the central axis x, the trunk portion 15 can be configured from three trunk constituents 30, if four openings 26 are formed in the trunk portion 15, the trunk portion 15 can be configured from four trunk constituents 30, and if five openings 26 are formed in the trunk portion 15, the trunk portion 15 can be configured from five trunk constituents 30. In other words, the trunk portion 15 can be configured from the same number of trunk constituents 30 as the number of openings 26, and if the number of openings 26 is an even number, the number of trunk constituents 30 will also be an even number, and if the number of openings 26 is an odd number, the number of trunk constituents 30 will also be an odd number.

[0044] In this embodiment, the inclined surface 19 and the hinge portion 25 are formed on each of the two body portion constituents 30. The two body portion constituents 30 have substantially the same shape. That is, in this embodiment, the inclined surface 19 and the hinge portion 25 are formed on both sides in the diameter direction of the body portion 15 that sandwich the central axis x. The inclined surface 19 is formed at the center in the width direction of the trunk constituent 30 (the direction orthogonal to the central axis x), and on both sides of the inclined surface 19, the outer surface of the trunk constituent 30 is a curved surface imitating the surface of an imaginary cylinder (not shown). Also, as described above, the cross section of the rod-shaped main body 3 constituting the shaft 1 in the direction orthogonal to the central axis x is substantially circular at any position. As a result, in the range where the inclined surface 19 is formed, the trunk constituent 30 has the smallest wall thickness 20 at the middle position in the width direction (FIGS. 11 and 12). As a result, when the buckling occurs, the portion 29 of the inclined surface 19 facing the hole edge Pb on the insertion destination side can be bent in a controlled state in the direction indicated by the symbol r in FIG. 7, centered on an imaginary line segment z (see FIGS. 7, 11, and 12) that is tangent to the inclined surface 19 and orthogonal to the central axis x.

[0045] The body 15 of the grommet body 2 is inserted into the hole Pa of the fastening object P until the head 12 of the grommet body 2 abuts against one surface of the fastening object P (FIG. 4). From this state, a pressing operation is performed in which head 12 of grommet body 2 is pressed against one surface of the fastening target P, while a removal operation is performed in which shaft body 1 is removed from grommet body 2. As a result, hook portion 6 of the shaft applies a force to body 15 in a direction that moves terminal portion 18 side of body 15 of grommet body 2 toward base portion 17 side. This force bends body 15 at base 17 side and terminal portion 18 side so that the central axis x side is on the outside of the bend, and also bends the portion between them so that the central axis x side is on the inside of the bend (buckling center 28), and is bent at three spaced locations in the direction along central axis x (FIG. 5). In this embodiment, the bending center on the terminal portion 18 side is controlled by hinge portion 25. This causes the body 15 on the other side of the fastening object P to buckle and expand like a crimp, thereby clamping the fastening object P between the body 15 and the head 12 from the inside and outside, front and back, front and back, or top and bottom, and typically multiple fastening objects P that are stacked on top of each other can be integrated (fastened) together via the fastener (see Figures 5 and 6). In the illustrated example, the two trunk constituent bodies 30 are each deformed as described above by the extraction operation.

[0046] Typically, the fastener is fastened to the object P using a known automatic fastening machine (not shown) that is capable of supplying the fastener intermittently and is configured to perform the pressing operation and the pulling operation following the insertion (driving) operation of the body 15 of the grommet body 2 into the hole Pa of the object P to be fastened.

[0047] As described above, the portion 29 of the inclined surface 19 that faces the hole edge Pb located on the insertion side of the body 15 in the hole Pa of the fastening object P varies depending on the thickness of the fastening object P. The inclined surface 19 has a length, and depending on this length, it can accommodate fastening of multiple types of fastening objects P with different thicknesses.

[0048] The amount of extraction of the shaft 1 by the extraction operation varies depending on the thickness of the fastening object P. The portion of the shaft 1 that protrudes from the head 12 after the extraction operation is cut off as needed using the automatic fastening machine or the like (see Figure 7).

[0049] The tapered surface 8b of the circumferential raised portion 8 elastically deforms the grommet body 2 mainly in a direction that expands the accommodation portion 16, so that the shaft body 1 can be extracted from the grommet body 2 without causing internal damage to the grommet body 2. In the illustrated example, the state in which the fastening object P is sandwiched between the head 12 and the buckled body 15 is stably maintained by engaging the circumferential engaged surface 14 with the engaging surface 8a of the circumferential raised portion 8 that is positioned on the circumferential engaged surface 14 of the multi-stage circumferential raised portion 8 when the extraction operation is stopped.

[0050] Depending on the direction of inclination of the inclined surface 19, the wall thickness 20 of the body 15 at a portion 29 of the inclined surface 19 facing the hole edge Pb located on the insertion side of the body 15 can be made always thinner than the wall thickness 20 of the body 15 located closer to the terminal portion 18. As a result, during the buckling, the portion 29 is always weaker and more easily bent by the force than a position closer to the buckling center 28, and therefore, during the buckling, the base 17 side of the body 15 is prevented from bending as much as possible at a position biased toward the buckling center 28 than the portion 29. As a result, when the body portion 15 buckles, the base portion 17 side of the body portion 15 can be bent around this point 29, with the point 29 of the inclined surface 19 always pressed against the hole edge Pb located on the insertion side of the body portion 15. As a result, it is possible to prevent a gap in a direction perpendicular to the central axis x from occurring between the buckled body portion 15 and the hole edge Pb located on the insertion side of the body portion 15 in the hole Pa of the fastening object P (FIGS. 5 and 6). Furthermore, since the inclined surface 19 is composed of a flat surface, the inclined surface 19 can be pressed against the fastening object P on the insertion side between the base 17 of the buckled body portion 15 and the buckling center 28 (Figures 5 and 6).

[0051] It should be noted that the present invention is not limited to the above-described embodiments, but includes all embodiments that can achieve the object of the present invention. [Explanation of symbols]

[0052] P Fastening target Pa hole 1 shaft body 2 grommet body 12 Head 15 Torso 17 Base 18 Terminal 19 Slope 20 thickness x center axis

Claims

1. A shaft body, a grommet body having a head and a body, the shaft being opened at the head and housed in a housing portion extending along the central axis of the body with a portion of the shaft protruding outward from the opening, A fastener that fastens to an object by inserting a body portion of the grommet body into a hole of the object to be fastened and then using a part of the shaft body to extract a required amount of the shaft body from the grommet body, thereby buckling at least a part of the body body between a base portion on the head side and an end portion opposite thereto so as to move away from the central axis, thereby sandwiching the object to be fastened between the head and the body portion, A fastener in which a part of the outer surface of the body is an inclined surface that continues in a direction along the central axis and gradually increases the distance from the central axis as it approaches the terminal portion, and the thickness of the body within the range in which this inclined surface is formed gradually increases as it approaches the terminal portion, and furthermore, the inclined surface is formed by a flat surface.

2. 2. The fastener according to claim 1, wherein at least a portion of said inclined surface has a width that gradually decreases as it approaches said terminal portion.

3. 2. The fastener according to claim 1, wherein a thin hinge portion that is bent when the body buckles is formed between the inclined surface and the terminal portion of the body.

4. 2. The fastener according to claim 1, wherein the body portion is formed by integrating two or more body constituents at the base portion and the terminal portion, respectively, so that the storage portion is formed inside these bodies.

5. 5. The fastener according to claim 4, wherein the body is constituted by two of the body constituents, an opening is formed between the two body constituents in a direction along the central axis, and a convex portion that protrudes toward the terminal portion is formed on an opening edge on the base portion side of the opening.

6. A fastening structure comprising the fastener according to claim 1 and a fastening object having a hole through which the body of the grommet body in the fastener can be inserted, A fastening structure in which the inclined surface of the body is formed so that when the body is inserted into the hole to be fastened, one of the inclined surfaces faces the edge of the hole on the insertion side of the hole.

Images