fasteners

Abstract

To provide a fastener that can easily adjust an insertion load when inserting a leg portion in an attaching hole and a pull-out load when pulling out the leg portion from the attaching hole.SOLUTION: A fastener 10 has a head portion 20 and a leg portion 30. The leg portion 30 has a shaft portion 40, a plurality of ribs 50 and 60 projecting out from a shaft portion side surface in four directions, a plurality of elastic engaging pieces 70 disposed between the ribs with gaps, and engaging with an attaching hole, and a bridge portion 80 that couples both side portions of a tip end portion 73 of each elastic engaging piece 70 and a part on the heat portion 20 side with respect to axial direction tip ends of the ribs 50 and 60 adjacent in a circumferential direction, and is provided with a cavity inside. The plurality of ribs 50 and 60 project longer in an outer diametrical direction than an inner peripheral surface of the adjacent elastic engaging pieces 70.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a fastener to be attached to a mounting hole.

Background Art

[0002] For example, mounting holes are formed in a vehicle body panel or the like of an automobile, and a trim board or the like is attached to the vehicle body panel or the like through a fastener inserted into and fixed to the mounting hole.

[0003] As a conventional product of this kind, in Patent Document 1 below, a clip is described for mounting a predetermined attached member to a mounting plate by using a mounting hole formed through the front and back surfaces of the mounting plate. The clip includes an engaging portion inserted into the mounting hole and an assembling portion assembled to the attached member.

[0004] The engaging portion has a column having four plate-like portions and having a substantially cross-shaped cross-section, and four engaging pieces disposed between adjacent plate-like portions. Further, the base ends in the axial direction of the column and each engaging piece are connected to a stabilizer having a dish shape, and the tip ends in the axial direction of the column and each engaging piece are connected to a block portion having a substantially conical shape. Each engaging piece is capable of being elastically deformed. When the engaging portion is inserted into the mounting hole or pulled out from the mounting hole, each engaging piece is pressed against the inner periphery of the mounting hole and elastically deformed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the clip described in Patent Document 1, the only part of the engaging portion that can be flexibly deformed within the part inserted into the mounting hole is the engaging piece. Therefore, the insertion load (also called insertion force) when inserting the engaging portion into the mounting hole and the extraction load (also called extraction force) when pulling the engaging portion out of the mounting hole must be controlled solely by the shape of each engaging piece, which has the disadvantage of being difficult to adjust.

[0007] Therefore, the object of the present invention is to provide a fastener that makes it easy to adjust the insertion load when inserting the leg into the mounting hole and the extraction load when pulling the leg out of the mounting hole. [Means for solving the problem]

[0008] To achieve the above objective, the present invention provides a fastener to be attached to a mounting hole, the fastener having a head that abuts against the front side of the mounting hole, and a leg that is inserted into the mounting hole and engages with the back side thereof, wherein the leg has a shaft portion extending from the back side of the head, a plurality of ribs protruding in four directions from the side of the shaft portion and extending from the back side of the head to the tip of the shaft portion, a plurality of elastic engaging pieces whose base end is connected to the back side of the head and which are arranged with a gap between adjacent ribs in the circumferential direction and which engage with the mounting hole, and a bridge portion which connects both sides of the tip of each elastic engaging piece and the portion of adjacent ribs in the circumferential direction that is closer to the head than the axial tip, and which has a cavity on the inside, wherein when the leg is viewed in a cross section perpendicular to the axial direction, the plurality of ribs protrude longer in the radiiary direction than the inner circumferential surface of adjacent elastic engaging pieces. [Effects of the Invention]

[0009] According to the present invention, since cavities are provided on both sides of the tip of each elastic engaging piece and inside the bridge portion that connects the portions of circumferentially adjacent ribs that are closer to the head than the axial tip, the bridge portion, in addition to the elastic engaging piece, can also be made to flex and deform, making it easier to adjust the insertion load when inserting the leg into the mounting hole and the extraction load when pulling the leg out of the mounting hole. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view showing one embodiment of the fastener according to the present invention. [Figure 2] This is a perspective view of the same fastener, but from a different direction than shown in Figure 1. [Figure 3] This is a front view of the fastener. [Figure 4] This is a side view of the fastener. [Figure 5] This is a plan view of the fastener. [Figure 6] This is a bottom view of the fastener. [Figure 7] This is a cross-sectional view along the line indicated by arrow AA in Figure 3. [Figure 8] This is a cross-sectional view along the line indicated by arrow BB in Figure 5. [Figure 9] This is a cross-sectional view along the DD arrow line in Figure 5. [Figure 10] This is an explanatory diagram showing the manufacturing equipment used to produce the fastener. [Figure 11] This is an explanatory diagram showing the mounting member attached to the mounting member via the fastener. [Figure 12] This is a cross-sectional view of the fastener in the state after it has been attached to the mounting hole. [Figure 13] (a) to (c) are cross-sectional views showing the state in which the fastener has shifted laterally from the state in Figure 11. [Modes for carrying out the invention]

[0011] (An embodiment of a fastener) Hereinafter, an embodiment of the fastener according to the present invention will be described with reference to the drawings.

[0012] This fastener is inserted into and fixed to a mounting hole formed in a predetermined mounting member. As shown in FIGS. 1 and 11, the fastener 10 in this embodiment is, for example, locked to a mounting seat 7 formed in the mounting member 5 and inserted into and fixed to a circular mounting hole 3 formed in the mounted member 1, and is used to mount the mounting member 5 to the mounted member 1.

[0013] Examples of the mounted member 1 include a vehicle body panel, a vehicle body frame, etc. Examples of the mounting member 5 include a trim board, a cover, a garnish, an assist grip, a bumper, a lamp, an insulator (soundproof material), etc., but are not limited thereto. Also, the mounting seat 7 of the mounting member 5 has a substantially L-shaped frame with one side (the receiving side of the fastener 10) open and a locking groove 8 formed on the bottom surface, and can hold the head 20 of the fastener 10 described later. However, for example, a circular insertion hole may be provided in the mounting member 5 and the head 20 of the fastener 10 may be engaged on the front side thereof, and there is no particular limitation. The fastener may be used not only for the above applications but also for closing a mounting hole (so-called hole plug), etc., and is not particularly limited.

[0014] In the present invention, the "front side of the mounting hole" means one side in the thickness direction of the mounted member in which the mounting hole is formed and on which the head of the fastener is disposed. When another member is placed on the mounted member, it means one side in the thickness direction of this other member, and includes the case where the head is indirectly disposed via another member on the front side of the mounting hole. Also, the "back side of the mounting hole" in the present invention means the other side in the thickness direction of the mounted member in which the mounting hole is formed and opposite to the side where the head of the fastener is disposed.

[0015] As shown in FIGS. 1 and 2, the fastener 10 has a head 20 that abuts on the front side of the mounting hole 3 and a leg 30 that is inserted into the mounting hole 3 and engages on the back side thereof.

[0016] In addition, in FIG. 3, the insertion direction of the leg portion 30 into the mounting hole 3 is indicated by the symbol "F1". The "back side" of each part of the fastener (head, leg, shaft, rib, elastic engagement piece, bridge portion, etc.) means the side facing the insertion direction F1 of the leg portion 30 into the mounting hole 3, and the "front side" of each of the above parts of the fastener means the side opposite to the insertion direction F1.

[0017] Next, each part constituting the fastener 10 will be specifically described. First, the head 20 will be described.

[0018] As shown in FIGS. 8 and 9, the head 20 in this embodiment includes a neck portion 21 having a bottomed cylindrical shape inserted into the locking groove 8 of the mounting seat 7 of the mounting member 5 and having a closed bottom, a disc-shaped first flange portion 22 extending from the outer periphery of the tip of the neck portion 21, a thin disc-shaped second flange portion 23 extending from the outer periphery at a predetermined axial position of the neck portion 21, and a third flange portion 24 connected to the back surface side of the second flange portion 23 and having an outer periphery that spreads in a skirt shape obliquely outward toward the leg portion 30 side.

[0019] Also, on the surface side of the first flange portion 22, a concave portion 22а is formed that is recessed so as to gradually deepen toward the outer side in the radial direction (see FIGS. 8 and 9). Further, as shown in FIG. 5, on the surface of the first flange portion 22, a plurality of ridges 25 extending radially with the axis C1 of the head 20 as the center are provided. By these concave portions 22а and the plurality of ridges 25, while the surface side of the first flange portion 22 is thinned to achieve weight reduction, the necessary strength is ensured.

[0020] Then, by inserting the neck portion 21 of the head 20 into the locking groove 8 of the mounting seat 7 and sandwiching the mounting seat 7 between the first flange portion 22 and the second flange portion 23, the fastener 10 is attached to the mounting seat 7 (see FIG. 11).

[0021] Next, the leg portion 30 will be described.

[0022] The leg portion 30 has a shaft portion 40 extending from the back side of the head portion 20, a plurality of ribs (first rib 50 and second rib 60) that protrude in four directions from the sides 41, 43 (see Figure 7) of the shaft portion 40 and extend from the back side of the head portion 20 to the tip of the shaft portion 40, a plurality of elastic engaging pieces 70 whose base end 71 is connected to the back side of the head portion 20 and are arranged between adjacent ribs 50, 60 in the circumferential direction with a gap S1 in between, and which engage with the mounting hole 3, and a bridge portion 80 that connects both sides of the tip portion 73 of each elastic engaging piece 70 and the portions of adjacent ribs 50, 60 that are closer to the head portion 20 than their axial tips, and has a cavity S3 on its inside. Also, as shown in Figure 7, when the leg portion 30 is viewed in a cross section perpendicular to the axial direction, the plurality of ribs 50, 60 protrude longer in the radiiary direction than the inner circumferential surface 76 of the adjacent elastic engaging piece 70.

[0023] In this embodiment, as shown in Figure 7, the shaft portion 40 has a rectangular prism shape with four sides when the leg portion 30 is viewed from the axial direction, specifically in a cross-section perpendicular to the axial direction (the direction along the axis C2 of the leg portion 30). That is, the shaft portion 40 has a pair of first sides 41, 41 arranged parallel to each other, and a pair of second sides 43, 43 arranged perpendicular to the pair of first sides 41, 41. Furthermore, the base end of the axial base portion 45 of the shaft portion 40 is connected to the central part of the back side of the third flange portion 24 that constitutes the head portion 20. As shown in Figure 2, a circular abutment surface 47a is formed at the very tip of the axial tip portion 47 of the shaft portion 40. This abutment surface 47a is the part that an ejector pin (not shown) will abut against when the fastener 10 is removed from the pair of molds 110, 110 after it has been manufactured using the manufacturing apparatus 100 (see Figure 10), which will be described later.

[0024] Furthermore, the ribs in this embodiment have a pair of first ribs 50, 50 and a pair of second ribs 60, 60 arranged to intersect the pair of first ribs 50, 50. In other words, as shown in Figure 7, the four ribs 50, 60 protrude outwards radially from the axis C2 of the leg portion 30 (or it can be said that the four ribs 50, 60 are arranged around the shaft portion 40 at equal intervals in the circumferential direction).

[0025] As shown in Figure 7, an elastic engaging piece 70 is positioned between a predetermined first rib 50 and a second rib 60 circumferentially adjacent to the first rib 50, resulting in a total of four elastic engaging pieces 70 positioned around the shaft portion 40. In other words, in this embodiment, the leg portion 30 is positioned around the shaft portion 40, with the first rib 50, elastic engaging pieces 70, and second rib 60 positioned on its outer circumference. The direction in which the first rib 50, elastic engaging pieces 70, and second rib 60 are positioned is defined as the circumferential direction of the leg portion 30. Furthermore, the direction from the axis C2 of the shaft portion 40 toward the outside of the shaft portion, or from the outside of the shaft portion toward the axis C2 of the shaft portion 40, is defined as the radial direction of the leg portion 30.

[0026] Each elastic engaging piece 70 has its axial base end 71 connected to the back side of the head 20 (in this case, the back side of the third flange portion 24), and its axial tip 73 connected to the first rib 50 and the second rib 60 via the bridge portion 80. Furthermore, a gap S1 is interposed between one circumferential side 70a of the axial base end 71 of each elastic engaging piece 70 and the side surface 51b of the axial base end 51 of the first rib 50. In addition, a gap S1 is also interposed between the other circumferential side 70a of the axial base end 71 of each elastic engaging piece 70 and the side surface 61b of the axial base end 61 of the second rib 60.

[0027] Furthermore, a gap S2 is provided inside the elastic engaging piece 70, and this gap S2, along with the gap S1, allows the elastic engaging piece 70 to bend and deform (elastically deform). The elastic engaging piece 70 is positioned between the first rib 50 and the second rib 60 such that the direction of its bending deformation (see arrow in Figure 7) is directed toward the second rib 60.

[0028] Furthermore, as shown in Figures 1 to 4, each elastic engaging piece 70 has a shape that is slightly bulging radially outward from the leg portion 30, and as shown in Figure 7, its outer circumferential surface 75 is arc-shaped corresponding to the circular mounting hole 3, and its inner circumferential surface 76 is also arc-shaped corresponding to the outer circumferential surface 75. In addition, a stepped engaging portion 77 is formed on the outer circumferential surface 75 on the axial base end portion 71 side of each elastic engaging piece 70. As shown in Figure 11, this engaging portion 77 is designed to engage with the rear periphery of the mounting hole 3.

[0029] Returning to the description of the ribs, as shown in Figure 7, the first rib 50 protrudes from the widthwise center of a pair of first side surfaces 41, 41 of the shaft portion 40. Furthermore, the first rib 50 protrudes in a manner that is narrower than the first side surfaces 41 of the shaft portion 40.

[0030] As shown in Figure 8, of the portion of the first rib 50 that extends axially from the back side of the head 20, the portion close to the head 20 is designated as the axial base end 51 (hereinafter also simply referred to as the "axial base end 51"), and the portion away from the head 20 is designated as the axial tip end 53 (hereinafter also simply referred to as the "axial tip end 53"). Also, as shown in Figure 7, of the portion of the first rib 50 that protrudes from the first side surface 41 of the shaft portion 40, the portion close to the first side surface 41 of the shaft portion 40 is designated as the protruding base end 55 (hereinafter also simply referred to as the "protruding base end 55"), and the portion away from the first side surface 41 of the shaft portion 40 is designated as the protruding tip end 57 (hereinafter also simply referred to as the "protruding tip end 57"). Note that the above "protruding direction" can also be referred to as the "radial direction". Furthermore, in the following explanation, when simply referred to as "axial base end 51," unless otherwise specified, it includes the protruding base end 55 and the protruding tip end 57 of the axial base end 51, and when simply referred to as "axial tip end 53," unless otherwise specified, it includes the protruding base end 55 and the protruding tip end 57 of the axial tip end 53.

[0031] As shown in Figure 8, the base end of the axial base end 51 of each first rib 50 is connected to the back side of the head 20 (in this case, the back side of the third flange portion 24). Furthermore, the outer circumferential surface 51a of the axial base end 51 (which can also be called the outer circumferential surface of the protruding tip 57) protrudes a constant amount from the first side surface 41 of the shaft portion 40 (see Figure 2). In addition, both side surfaces 51b, 51b of the axial base end 51 of each first rib 50 are parallel to each other (see Figure 8).

[0032] Furthermore, as shown in Figures 2 and 4, the outer circumferential surface 53a of the axial tip 53 of each first rib 50, that is, the outer circumferential surface of the protruding tip 57 of the axial tip 53, has a shape that gradually narrows while forming a curved surface toward the very front of the leg portion 30. Moreover, this axial tip 53 extends to the very front of the tip 47 of the shaft portion 40. In addition, both sides 53b, 53b in the width direction of the axial tip 53 are parallel to each other (see Figure 8). Furthermore, each side 53b of the axial tip 53 has a continuous, flush shape without any steps relative to the second side 43 of the shaft portion 40 (see Figure 7), and also has a continuous, flush shape without any steps in the axial direction of the leg portion 30 (see Figure 8), allowing the pin member 130 (see Figure 10) of the manufacturing apparatus 100, which will be described later, to be inserted into and removed from the pair of molds 110 and 120. Furthermore, the bridge portion 80 is connected to both sides in the circumferential direction of the portion of the axial tip portion 53 that is closer to the head portion 20 than the axial tip, in this case, the axial base portion 51 of the axial tip portion 53. (This will be described in detail in the explanation of the bridge portion 80.)

[0033] Furthermore, as shown in Figure 8, the axial tip 53 of the first rib 50 is formed to be wider than the axial base 51. Specifically, the width W2 of the axial tip 53 of the first rib 50 (the length between the two sides 53b, 53b in the width direction) is formed to be larger than the width W1 of the axial base 51 (the length between the two sides 51b, 51b in the width direction). Also, both widths W1 and W2 are constant.

[0034] In other words, each first rib 50 has an axial base end 51 extending axially from the back side of the head 20 with a constant width W2, and an axial tip 53 is attached to the axial tip of the axial base end 51 via a step 54, which is wider than the axial base end 51 and extends axially with a constant width W1. In this embodiment, in both the protruding base end 55 and the protruding tip 57 of the first rib 50, the axial base end 51 side is narrower than the axial tip 53 side (see Figure 7).

[0035] Furthermore, as shown in Figure 7, when the leg portion 30 is viewed in a cross-section perpendicular to the axial direction, each first rib 50 protrudes longer in the radial direction than the inner circumferential surface 76 of the elastic engagement piece 70 adjacent to the leg portion 30 in the circumferential direction. That is, the protruding tip portion 57 of each first rib 50 extends radially outward from the inner circumferential surface 76 of the elastic engagement piece 70.

[0036] Next, we will explain the second rib 60.

[0037] As shown in Figure 7, the second ribs 60 protrude from the widthwise center of a pair of second sides 43, 43 of the shaft portion 40. Each second rib 60 protrudes so as to be narrower than the second side 43 of the shaft portion 40.

[0038] As shown in Figure 9, of the portion of the second rib 60 that extends axially from the back side of the head 20, the portion close to the head 20 is designated as the axial base end 61 (hereinafter also simply referred to as the "axial base end 61"), and the portion away from the head 20 is designated as the axial tip end 63 (hereinafter also simply referred to as the "axial tip end 63"). Also, as shown in Figure 7, of the portion of the second rib 60 that protrudes from the second side surface 43 of the shaft portion 40, the portion close to the second side surface 43 of the shaft portion 40 is designated as the protruding base end 65 (hereinafter also simply referred to as the "protruding base end 65"), and the portion away from the second side surface 43 of the shaft portion 40 is designated as the protruding tip end 67 (hereinafter also simply referred to as the "protruding tip end 67"). Note that the above "protruding direction" can also be called the "radial direction". Furthermore, in the following explanation, when simply referred to as "axial base portion 61," unless otherwise specified, it includes the protruding base portion 65 and the protruding tip portion 67 of the axial base portion 61, and when simply referred to as "axial tip portion 63," unless otherwise specified, it includes the protruding base portion 65 and the protruding tip portion 67 of the axial tip portion 63.

[0039] As shown in Figure 8, the axial base end 61 of each second rib 60 is connected to the back side of the head 20 (in this case, the back side of the third flange portion 24). Furthermore, the outer circumferential surface 61a of the axial base end 61 (which can also be called the outer circumferential surface of the protruding tip 67) protrudes a constant amount from the second side surface 43 of the shaft portion 40 (see Figure 1).

[0040] Furthermore, as shown in Figures 1 and 3, the outer circumferential surface 63a of the axial tip portion 63 of each second rib 60, that is, the outer circumferential surface of the protruding tip portion 67 of the axial tip portion 63, has a shape that gradually narrows while forming a curved surface toward the very tip of the leg portion 30. Moreover, this axial tip portion 63 extends to the very tip of the tip portion 47 of the shaft portion 40. In addition, bridge portions 80 are connected to both sides in the circumferential direction of the portion of the axial tip portion 63 that is closer to the head portion 20 than the axial tip, in this case, the axial base portion 51 of the axial tip portion 63, and closer to the axial tip (this will be described in detail in the explanation of bridge portions 80).

[0041] Furthermore, as shown in Figure 9, at the protruding base end 65 of each second rib 60, the width is the same from the axial base end 61 side to the axial tip end 63 side. Also, as shown in Figure 4, at the protruding tip end 67 of each second rib 60, the axial base end 61 side is wider than the axial tip end 63 side (see Figure 4).

[0042] Specifically, as shown in Figure 9, when the leg portion 30 is viewed in a predetermined longitudinal section parallel to the axial direction, the protruding base end portion 65 of each second rib 60 extends with the same width from the base end of the axial base end portion 61 to the tip of the axial tip portion 63. That is, at the protruding base end portion 65 of each second rib 60, both side surfaces 65a, 65a in the width direction extend with a constant width W3 (the length between the two side surfaces 65a, 65a) from the base end of the axial base end portion 61 to the tip of the axial tip portion 63. Furthermore, each side surface 65a of the protruding base end portion 65 has a continuous, flat shape without any steps or continuity in the axial direction of the leg portion 30 (see Figure 9), allowing the pin member 130 of the manufacturing apparatus 100 (see Figure 10), which will be described later, to be inserted into and removed from the pair of molds 110, 120. Furthermore, as shown in Figure 4, when the leg portion 30 is viewed from the radially outward direction, each second rib 60 is wider on the axial base end portion 61 side than on the axial tip end portion 63 side.

[0043] Furthermore, as shown in Figure 7, when the leg portion 30 is viewed in a cross-section perpendicular to the axial direction, each second rib 60 protrudes longer in the outer diameter direction than the inner circumferential surface 76 of the elastic engagement piece 70 adjacent to the leg portion 30 in the circumferential direction. That is, the protruding tip portion 67 of each second rib 60 extends radially outward from the inner circumferential surface 76 of the elastic engagement piece 70.

[0044] Furthermore, as shown in Figure 7, the circumferential distance L2 (length along the circumferential direction of the leg portion 30) between the second rib 60 and the circumferentially adjacent elastic engaging piece 70 is larger than the circumferential distance L1 between the first rib 50 and the circumferentially adjacent elastic engaging piece 70. Here, as shown in Figure 7, the circumferential distance L2 between the side surface of the protruding tip portion 67 at the axial base end portion 61 of the second rib 60 and the side portion 70a of the circumferentially adjacent elastic engaging piece 70 is larger than the circumferential distance L1 between the side surface of the protruding tip portion 57 at the axial base end portion 51 of the first rib 50 and the side portion 70a of the circumferentially adjacent elastic engaging piece 70.

[0045] Furthermore, the protruding tip 67 of the second rib 60 is wider than the protruding base end 65 of the second rib 60 and is also wider than the protruding base end 55 of the first rib 50. Here, as shown in Figure 7, the width of the protruding tip 67 of the second rib 60 is wider than the width of the protruding base end 65 of the second rib 60 and is also wider than the width of the protruding tip 57 at the axial base end 51 of the first rib 50 (meaning W1; see Figure 8).

[0046] Next, the bridge section 80 will be described.

[0047] As shown in Figures 1-4 and Figure 6, the bridge portion 80 of this embodiment has a first connecting portion 81 that connects one side of the tip portion 73 of the elastic engaging piece 70 and the portion of the first rib 50 that is closer to the head 20 than the axial tip, and a second connecting portion 83 that connects the other side of the tip portion 73 of the elastic engaging piece 70 and the portion of the second rib 60 that is closer to the head 20 than the axial tip. Furthermore, a cavity S3 (see Figures 1, 2, 8, 9, etc.) is provided inside the first connecting portion 81 and the second connecting portion 83 that constitute the bridge portion 80 (radially inside the leg portion 30). This cavity S3 causes the bridge portion 80 to be pressed against the inner circumference of the mounting hole 3 when the leg portion 30 is inserted into the mounting hole 3 or when the leg portion 30 is pulled out of the mounting hole 3, causing the bridge portion 80 to bend and deform.

[0048] More specifically, the first connecting portion 81 connects the circumferential side of the tip portion 73 of the elastic engaging piece 70 (the side facing the first rib 50) with the circumferential side of the axial tip portion 53 of the first rib 50, located near the axial tip of the axial base portion 51, and facing the elastic engaging piece 70 (see Figure 3).

[0049] On the other hand, the second connecting portion 83 connects the other circumferential side of the tip portion 73 of the elastic engaging piece 70 (the side that is circumferentially close to the second rib 60) with the circumferential side of the axial tip portion 63 of the second rib 60, which is located near the axial tip of the axial base portion 61 and is circumferentially close to the elastic engaging piece 70 (see Figure 4).

[0050] Furthermore, as shown in Figures 1 and 2, the axial end edge 81a of the first connecting portion 81 and the axial end edge 83a of the second connecting portion 83, together with the edge 73a of the tip portion 73 of the elastic engaging piece 70, are angled to gradually narrow toward the head portion 20, and have a constricted shape such that the axial length is shortened in a predetermined circumferential portion of the second connecting portion 83, thereby ensuring the rigidity of the bridge portion 80 while also ensuring its flexibility.

[0051] Furthermore, in this leg portion 30, the space enclosed by the shaft portion 40, the first rib 50, the second rib 60, the elastic engaging piece 70, and the bridge portion 80 (including the void S2 inside the elastic engaging piece 70 and the cavity S3 inside the bridge portion 80) extends through the axial tip side of the leg portion 30 toward the axial base end side. As shown in Figures 1 to 4, the opening shape of the above space on the axial tip side of the leg portion 30 is an almond or rugby ball shape, with the axial tip and base ends narrowed and the middle section of the axial direction bulging.

[0052] The fastener, having the above configuration, can be made from, for example, a polyamide resin such as nylon, or a resin material such as polyacetal (POM) or polypropylene (PP). Alternatively, it may be made from a fiber-reinforced resin, which is reinforced by incorporating glass fibers, carbon fibers, metal fibers, etc. into the above resin material. Furthermore, each part constituting the fastener 10, namely the head 20, leg portion 30, shaft portion 40, first rib 50, second rib 60, elastic engaging piece 70, bridge portion 80, etc., is formed as a single unit.

[0053] As described above, the fastener 10 is integrally formed, and in connection with this, a method for manufacturing the fastener 10 will be described. A fastener 10 like the one in this embodiment can be manufactured, for example, using a manufacturing apparatus 100 as shown in Figure 10.

[0054] The manufacturing apparatus 100 has a pair of molds 110 and 120 that move toward and away from each other in the direction indicated by arrow F2 in Figure 10. The pair of molds 110 and 120 mainly form the outer shape of the head 20 and leg portion 30, etc. When the opposing surfaces of the pair of molds 110 and 120 abut against each other, they close, defining a predetermined cavity. The part where the opposing surfaces of the molds 110 and 120 abut against each other is called the parting line PL. Furthermore, the manufacturing apparatus 100 has a plurality (four in this case) of columnar pin members 130 that reciprocate in a direction perpendicular to the movement direction F2 of the pair of molds 110 and 120. Each pin member 130 is inserted into a pair of molds 110 and 120 and primarily forms a space enclosed by the second side surface 43 of the shaft portion 40, the inner shape of the elastic engaging piece 70, the side shape of the first rib 50, and the shaft portion 40, the first rib 50, the second rib 60, the elastic engaging piece 70, and the bridge portion 80 as described in paragraph 0051.

[0055] Then, the pair of molds 110 and 120 are closed, and a plurality of pin members 130 are inserted and positioned inside the pair of molds 110 and 120 to define a cavity for forming the fastener. In this state, a predetermined resin material is injected into the cavity, and then the plurality of pin members 130 are withdrawn, and the pair of molds 110 and 120 are opened. After that, the fastener 10 can be manufactured by removing it from the pair of molds 110 and 120.

[0056] (modified version) The shape, structure, and position of each part of the fastener described above, such as the head, shaft, legs, ribs, elastic engaging piece, and bridge, are not limited to the above-described embodiments.

[0057] The head portion 20 in this embodiment has a structure consisting of a neck portion 21 and a plurality of flange portions 22, 23, 24. However, the structure of the head portion is not limited to this embodiment, and any shape that abuts against the front side of a mounting hole formed in a predetermined mounting member and engages with the front peripheral edge of the mounting hole is acceptable.

[0058] Furthermore, although the shaft portion 40 is a solid, roughly rectangular prism shape with four sides, the shaft portion may also be, for example, rectangular, cylindrical, or cylindrical in shape.

[0059] Furthermore, the ribs in this embodiment consist of four ribs 50, 60 arranged orthogonally to each other, with adjacent ribs 50, 60 in the circumferential direction being arranged orthogonally. However, the arrangement angle between adjacent ribs in the circumferential direction may be other than 90°.

[0060] Furthermore, the first rib may be configured such that, for example, (1) the axial base end is wider than the axial tip end, (2) the axial base end and the axial tip end are the same width, or (3) the tip end in the protruding direction is wider than the base end in the protruding direction.

[0061] Furthermore, as a second rib, for example, (1) at the base end in the protruding direction, the width between the axial base end and the axial tip end may be varied, or (2) at the tip end in the protruding direction, the axial tip end may be narrower than the axial base end, or the axial tip end and the axial base end may be the same width.

[0062] Furthermore, in this embodiment, the bridge portion 80 has a constricted shape, with the edges 81a and 83a of both connecting portions 81 and 83 having the same shape as the edge 73a of the tip portion 73 of the elastic engaging piece 70 (see paragraph 0050). However, the bridge portion may, for example, be a plate-like shape with a nearly constant axial length, as long as it can connect the elastic engaging piece and the ribs and has a cavity on the inside.

[0063] (Effects and Benefits) Next, the method of use and effects of the fastener 10, which has the above configuration, will be explained.

[0064] First, the neck portion 21 of the head portion 20 of the fastener 10 is inserted into the locking groove 8 of the mounting seat 7 of the mounting member 5, and the fastener 10 is attached to the mounting seat 7 by sandwiching the mounting seat 7 between the first flange portion 22 and the second flange portion 23 (see Figure 11).

[0065] In this state, the legs 30 of the fastener 10 are inserted into the mounting hole 3 of the member to be mounted 1 from its front side. As a result, multiple elastic engaging pieces 70 are pressed against the inner circumference of the mounting hole 3, and each elastic engaging piece 70 deforms inward toward the legs through the gap S1 and the gap S2 inside it. At the same time, the first connecting portion 81 and the second connecting portion 83 of the bridge portion 80 are pressed against the inner circumference of the mounting hole 3, and the bridge portion 80 also deforms inward toward the legs through the cavity S3. In addition, the outer peripheral edge of the third flange portion 24 of the head portion 20 is pressed against the front side of the member to be mounted 1 and deforms inward as it is pushed out. After that, when the engaging portions 77, 77 of each elastic engaging piece 70 come out to the back side of the mounting hole 3, each elastic engaging piece 70 and each bridge portion 80 elastically return to their original position. As shown in Figures 11 and 12, the engaging portion 77 of each elastic engaging piece 70 engages with the back peripheral edge of the mounting hole 3, and the third flange portion 24 of the head 20 abuts against the front side of the mounting hole 3. As a result, the fastener 10 is attached to the mounting hole 3, and as shown in Figure 11, the mounting member 5 can be attached to the member to be mounted 1 via the fastener 10. Figure 12 shows a cross-section of the leg portion 30 perpendicular to the axial direction when the fastener 10 is attached to the mounting hole 3. In this state, the protruding tip portions 57 of each first rib 50 and the protruding tip portions 67 of each second rib 60 do not abut against the inner circumference of the mounting hole 3, but are spaced apart.

[0066] Incidentally, there are times when it is necessary to remove the mounting member 5 from the member to be mounted 1 for reasons such as maintenance or parts replacement. In this case, the mounting member 5 is grasped and separated from the member to be mounted 1, and the leg portion 30 is pulled out from the mounting hole 3. When this happens, the engaging portion 77 is pressed against the inner circumference of the mounting hole 3, and each elastic engaging piece 70 is pulled out while bending and deforming inward. If the leg portion 30 is pulled out at an angle relative to the center of the mounting hole 3, the bridge portion 80 may be pressed against the inner circumference of the mounting hole 3, and the bridge portion 80 may be bent and deformed. Once the axial tip of the leg portion 30 is completely pulled out from the mounting hole 3, the fastener 10 can be removed from the mounting hole 3, and consequently, the mounting member 5 can be removed from the member to be mounted 1.

[0067] Furthermore, in this fastener 10, a cavity S3 is provided on both sides of the tip portion 73 of each elastic engaging piece 70, and inside the bridge portion 80 that connects the portions of circumferentially adjacent ribs 50, 60 that are closer to the head portion 20 than the axial tip. Therefore, in addition to the elastic engaging pieces 70, the bridge portion 80 can also bend and deform. As a result, when inserting the leg portion 30 into the mounting hole 3 or when pulling the leg portion 30 out of the mounting hole 3, the bridge portion 80 also bends and deforms in addition to each elastic engaging piece 70, making it easier to adjust the insertion load (insertion force) when inserting the leg portion 30 into the mounting hole 3, and the pulling load (pulling force) when pulling the leg portion 30 out of the mounting hole 3 while the leg portion 30 is engaged with the mounting hole 3.

[0068] Furthermore, in this fastener 10, as shown in Figure 7, when the leg portion 30 is viewed in a cross-section perpendicular to the axial direction, the multiple ribs 50, 60 protrude longer in the radiiary direction than the inner circumferential surface 76 of the adjacent elastic engaging piece 70. Therefore, when the fastener 10 is attached to the mounting hole 3, if the fastener 10 is displaced laterally (lateral displacement), the ribs 50, 60 are more likely to come into contact with the inner circumference of the mounting hole 3.

[0069] This will be explained with reference to Figure 13. Specifically, if the leg portion 30 is displaced in a direction perpendicular to the axial direction (lateral displacement) due to an external force acting on the fastener 10, for example, from a state where the axis C2 of the leg portion 30 shown in Figure 12 is aligned with the axis of the mounting hole 3, then the ribs 50 and 60 will come into contact with the inner circumference of the mounting hole 3 in the following manner.

[0070] For example, (1) as shown in Figure 13(a), the protruding tip 57 of the first rib 50 located at the top of the paper comes into contact with the inner circumference of the mounting hole 3; (2) as shown in Figure 13(b), the protruding tip 67 of the second rib 60 located on the left side of the paper comes into contact with the inner circumference of the mounting hole 3; and (3) as shown in Figure 13(c), the protruding tip 57 of the first rib 50 located at the top of the paper and the protruding tip 67 of the second rib 60 located on the left side of the paper come into contact with the inner circumference of the mounting hole 3.

[0071] As described above, even if the fastener 10 is mounted in the mounting hole 3 and shifts laterally, either one or both of the first rib 50 or the second rib 60 are likely to come into contact with the inner circumference of the mounting hole 3. Therefore, even if an external force acts on the fastener 10, it is possible to suppress the leg portion 30 from shifting relative to the mounting hole 3.

[0072] Furthermore, in this embodiment, the rib has a pair of first ribs 50, 50 and a pair of second ribs 60, 60 arranged to intersect the pair of first ribs 50, 50. As shown in Figure 7, the circumferential spacing L2 between the second rib 60 and the circumferentially adjacent elastic engaging piece 70 is greater than the circumferential spacing L1 between the first rib 50 and the circumferentially adjacent elastic engaging piece 70. The protruding tip 67 of the second rib 60 is wider than the protruding base end 65, and the protruding base end 55 of the first rib 50 is wider.

[0073] According to the above embodiment, the circumferential distance L2 between the second rib 60 and the circumferentially adjacent elastic engaging piece 70 is greater than the circumferential distance L1 between the first rib 50 and the circumferentially adjacent elastic engaging piece 70, so that the mold used to form the shape between the second rib 50 and the circumferentially adjacent elastic engaging piece 70 can be easily removed. At the same time, positional displacement that occurs in the portion of the mounting hole 3 where the distance L2 between the second rib 60 and the elastic engaging piece 70 is wide can be suppressed by the protruding tip portion 67 formed on the second rib 60, which is wider than the protruding base end portion 65.

[0074] Furthermore, in this embodiment, as shown in Figure 9, the protruding base end 65 of each second rib 60 has the same width from the axial base end 61 to the axial tip end 63, and as shown in Figure 4, the protruding tip end 67 of each second rib 60 is wider on the axial base end 61 side than on the axial tip end 63.

[0075] According to the above aspect, since each second rib 60 has the above-described configuration, the axial base end portion 61, which is the portion of the second rib 60 that abuts against the inner circumference of the mounting hole 3, is widened, while reducing the necessary material for other portions, thereby reducing the cost of the entire fastener 10.

[0076] Also, in this embodiment, as shown in FIG. 8, the axial tip portion 53 of the first rib 50 is formed wider than the axial base end portion 51 (the width W2 of the axial tip portion 53 is larger than the width W1 of the axial base end portion 51).

[0077] According to the above aspect, since the first rib 50 has the above configuration, the rigidity of the leg portion 30 when inserting the leg portion 30 into the mounting hole 3 can be increased. Further, since the axial base end portion 51 of the first rib 50 is narrower than the axial tip portion 53 (W1 < W2), a wider circumferential width can be ensured at the axial base end portion 71 of the elastic engagement piece 70, and the removal force of the fastener 10 with respect to the mounting hole 3 can be increased.

[0078] Also, in this embodiment, as shown in FIG. 7, the shaft portion 40 has a quadrangular prism shape with four side surfaces 41, 43, and each first rib 50 and each second rib 60 project so as to be narrower than each side surface 41, 43 of the shaft portion 40.

[0079] According to the above aspect, since the shaft portion 40 has a quadrangular prism shape and each first rib 50 and each second rib 60 project so as to be narrower than each side surface 41, 43 of the shaft portion 40, while thickening the shaft portion 40, the length (radial length) in the protruding direction of each rib 50, 60 can be shortened, and the rigidity of each rib 50, 60 can be increased.

[0080] Note that the present invention is not limited to the above-described embodiments, and various modified embodiments are possible within the scope of the gist of the present invention, and such embodiments are also included in the scope of the present invention.

Explanation of Reference Numerals

[0081] 3 Mounting hole 10 fasteners 20 heads 30 Legs 40 Shaft section 50 First Rib 51 Axial base end (axial base end) 53 Axial tip (Axial tip) 55 Base end in the protruding direction (base end in the protruding direction) 57. Protruding tip (Protruding tip) 60. Second Rib 61 Axial base end (Axial base end) 63 Axial tip (Axial tip) 65. Base end in the protruding direction (base end in the protruding direction) 67. Protruding tip (Protruding tip) 67 Tip in protruding direction 70 Elastic engaging piece 71 Proximal end 73 Tip 80 Bridge section 81 1st connection part 83 2nd connection part

Claims

1. A fastener that is attached to a mounting hole, It has a head that abuts against the front side of the mounting hole and a leg that is inserted into the mounting hole and engages with the back side thereof. The aforementioned leg portion is A shaft portion extending from the back side of the head, Multiple ribs protrude in four directions from the side of the shaft portion and extend from the back of the head portion to the tip of the shaft portion, The base end is connected to the back side of the head, and is arranged between adjacent ribs in the circumferential direction with a gap in between, and comprises a plurality of elastic engaging pieces that engage with the mounting hole, Each elastic engaging piece has both sides of its tip, and a bridge portion that connects the portions of the circumferentially adjacent ribs that are closer to the head than their axial tips, and has a cavity on the inside. When the leg portion is viewed in a cross-section perpendicular to the axial direction, the plurality of ribs protrude outward longer than the inner circumferential surface of the adjacent elastic engaging piece. The rib comprises a pair of first ribs and a pair of second ribs arranged to intersect the pair of first ribs. The circumferential distance between the second rib and the circumferentially adjacent elastic engaging piece is greater than the circumferential distance between the first rib and the circumferentially adjacent elastic engaging piece. A fastener characterized in that the tip of the second rib in the protruding direction is wider than the base of the second rib in the protruding direction, and is also wider than the tip of the first rib in the protruding direction.

2. At the base end of the second rib in the protruding direction, the width is the same from the base end to the tip in the axial direction. The fastener according to claim 1, wherein the tip of the second rib in the protruding direction is wider on the base end side than on the tip in the axial direction.

3. The fastener according to claim 1 or 2, wherein the axial tip of the first rib is formed to be wider than the axial base.

4. The fastener according to claim 1 or 2, wherein the shaft portion is in the shape of a rectangular prism having four sides, and each first rib and each second rib protrudes so as to be narrower than each side of the shaft portion.

5. A fastener that is attached to a mounting hole, It has a head that abuts against the front side of the mounting hole and a leg that is inserted into the mounting hole and engages with the back side thereof. The aforementioned leg portion is A shaft portion extending from the back side of the head, Multiple ribs protrude in four directions from the side of the shaft portion and extend from the back of the head portion to the tip of the shaft portion, The base end is connected to the back side of the head, and is arranged between adjacent ribs in the circumferential direction with a gap in between, and comprises a plurality of elastic engaging pieces that engage with the mounting hole, Each elastic engaging piece has both sides of its tip, and a bridge portion that connects the portions of the circumferentially adjacent ribs that are closer to the head than their axial tips, and has a cavity on the inside. When the leg portion is viewed in a cross-section perpendicular to the axial direction, the plurality of ribs protrude outward longer than the inner circumferential surface of the adjacent elastic engaging piece. The ribs consist of a pair of first ribs and ribs arranged to intersect the pair of first ribs. It has a pair of second ribs, The circumferential distance between the second rib and the circumferentially adjacent elastic engaging piece is greater than the circumferential distance between the first rib and the circumferentially adjacent elastic engaging piece. A fastener characterized in that the tip of the second rib in the protruding direction is formed to be wider than the tip of the first rib in the protruding direction.

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