JPS6327571B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a plastic blind type rivet comprising a female member and a male member, which is used for fixing a plurality of panels in a stacked state from one side.

<Prior Art> Blind type rivets consisting of both female and male members as described above have been known. This is the first
As shown in Figure 3, there is a cylindrical tube part 10 whose inner and outer shapes are both circular, and a collar 12 on the outer periphery of its open upper end.
The female member has a female member molded of plastic, and a shaft 14 passing through the cylindrical portion 10 of the female member.A head 16 for pulling is provided at the upper end of the shaft 14 protruding from the upper end of the female member. It consists of a plastic male member with an enlarged portion 18 at its lower end projecting from the open lower end of the female member 10. In the middle of the cylindrical portion of the female member, two flexible walls 22 which can be bent into a dogleg shape are formed by two longitudinally elongated slots 20 facing each other. Therefore, the cylindrical part 10 of the female member is inserted into the communicating hole of a plurality of laminated panels, the lower surface of the flange 12 is brought into contact with one side of the laminated panel, and the head 16 of the male member is held down by pressing the flange 12. When pulled to the left in FIG. 1, the pair of flexible walls 22 facing each other across the slot 20 are pushed by the enlarged portion 18 and bent outward in a dogleg shape, and the length of the cylindrical portion 10 is shortened. A locking pawl 2 consisting of a conical cam surface is provided at the middle part of the shaft of the male member that passes into the cylindrical part 10 of the female member, and at the upper part.
4 and 26 are provided in multiple stages with the large diameter portion facing the enlarged portion 18. Since the female member is molded outside the male member, jagged locking claws 24' and 26' corresponding to the locking claws 24 and 26 are provided at the middle and upper part of the inner surface of the cylindrical portion 10. arise. Therefore, when the male member is pulled upward and the female member's pair of flexible walls 22 are bent outward in a dogleg shape as described above, the locking pawl 24 at the middle portion of the shaft 14 engages inside the cylindrical portion 10. The male member 14 is prevented from returning in the opposite direction by being caught by the locking pawl 26' on the upper circumference, and the panel is laminated between the collar 12 of the female member and the pair of flexible walls 22 bent in a dogleg shape. are combined in a shape.

<Problems to be solved by the invention> As is clear from FIGS. 2 and 3, the shaft 1 of the male member
The flexible wall 2 of the female member has a circular cross-sectional shape.
The inner surface of the flexible wall 22 is a circular arc surface, and the cross-sectional shape of the flexible wall 22 is fan-shaped.

When the flexible wall 22 with a fan-shaped cross section is bent into a dogleg shape in this way, stress is concentrated on both bent ends 30 of the arc-shaped inner surface of the wall 22, and the flexible wall 22 is torn from that part. Bond strength may decrease.

<Means for Solving the Problems> Accordingly, the present invention provides a cylindrical portion having a cylindrical outer surface and provided around a plurality of axially flexible walls that can be bent into a dogleg shape, and an upper end portion of the cylindrical portion. a female member made of plastic having a flange projecting from the outer periphery; a shaft passing through the female member; an enlarged portion provided at the lower end of the shaft and in contact with the lower end of the cylindrical portion of the female member; a male member molded of plastic having a head provided at the upper end of the shaft protruding outward from the upper end of the member; and a plurality of flexible walls of the female member that are pulled up against the female member. In the plastic rivet in which both the female and male members are provided with locking claws that engage with each other to prevent the male member from returning downward when bent into a dogleg shape, the shaft of the male member has a polygonal cross-sectional shape. , having a plurality of flat surfaces in the axial direction on the outer surface, and each flexible wall of the female member having a flat inner surface that contacts each flat surface of the outer surface of the shaft of the male member.

<Function> As described above, in the present invention, since the inner surface of each flexible wall of the female member that is bent into a dogleg shape when the male member is pulled up is flat, no portion where stress is concentrated occurs when the female member is bent.

<Embodiment> FIGS. 4 and 5 show an embodiment of the present invention, in which a male member shaft 40 has a square cross-sectional shape and has locking claws 46 on a pair of opposite flat surfaces 44. This male member is housed in a female mold for molding the female member, and the female member is molded around it. At this time, the male member is held in the female mold by the other pair of side surfaces 45, As a result, the inner surfaces of the pair of flexible walls 42 separated by the slot 50 in the cylindrical portion of the female member are flat and have corresponding locking claws. In the embodiment shown in FIGS. 6 and 7, the male member shaft 40a has an oval cross-sectional shape and has a pair of back-to-back flat surfaces 44a, each of which has a locking pawl 46a. Both flat surfaces 44a are side curved surfaces 45a
The curvature of the side curved surface 45a is approximately equal to the outer diameter of the cylindrical portion of the female member. Therefore, the shaft 40a of the male member is held in the female mold by this side curved surface 45a, and the inner surface of the pair of flexible walls 42a of the cylindrical portion of the female member is flat and has a locking claw corresponding to the locking claw 46a. Form with

FIG. 8 shows a rivet using the male member shown in FIG.
The state in which the male member shaft 40a is pulled to the left and the female member's pair of flexible walls 42a are bent into a dogleg shape is shown in broken lines. The teeth of the locking pawl 46a on the flat outer surface 44a of the shaft of the male member and the flat inner surface of the flexible wall 42a of the female member formed thereby are sharp as shown in FIG. Although sawtooth 46 is ideal,
Sawtooth shape with rounded edges 4 as shown in Figure 10
7 is fine. This rounded tooth profile allows the plastic to swell better in the mold, eliminating the problem of distortion during the molding operation.

The cross-sectional shape of the shaft 40b of the male member in FIG. 11 is oval like in FIG. 7, but its side curved surface 4
The radius of 5b is smaller than the outer diameter of the cylindrical portion of the female member. Molding the female member around this male member results in a thin web 5 interconnecting the pairs of flexible walls 42b of the female member.
2 occurs on the side curved surface 45b. This web 52
The flexible wall 42b is torn or stretched when the flexible wall 42b is bent into a dogleg shape.

The cross-sectional shape of the shaft 40c of the male member shown in FIGS. 12 and 13 is square, and has locking claws 46c on a pair of opposite flat surfaces. The inner surface of the flexible wall of the female member molded around this male member is a flat surface with a locking pawl corresponding to the locking pawl 46c, and the opposing inner surface of the slot 50c separating the flexible wall is a draft surface. The cylindrical portion is inclined so as to open slightly toward the outer surface, and the inner surface of the flexible wall extends outward. The embodiment shown in FIG. 14 is almost the same as the embodiment shown in FIGS.
The difference is that d is provided only in a part of the width of the shaft 40d of the male member.

In the embodiments shown in FIGS. 15, 16, 17, and 18, locking pawls are provided on four flat surfaces of the shaft of a male member having a square cross-sectional shape.

In FIG. 15, the flexible walls 42e of the female member are molded onto each outer surface of the shaft 42e of the male member, with adjacent flexible walls 42e being separated by V-shaped grooves 64.

In FIGS. 16 and 17, the groove 64f is semicircular rather than V-shaped, as can be clearly seen in FIG. This groove 64f may penetrate from the outer surface of the cylindrical portion 10f of the female member to the corner of the square of the shaft 40f of the male member, or it may not pass through but end slightly before the corner of the shaft 40f of the male member. , the flexible wall 42f may be torn when it is bent into a dogleg shape by pulling the shaft 40f of the male member. Furthermore, if the enlarged portion 18f of the male member is also provided with grooves in the same arrangement, manufacturing and removal from the mold will be facilitated.

The shaft 40g of the male member in FIG. 18 has a corner in close proximity to the outer surface of the cylindrical portion 10g of the female member, and the female member is provided with a web 52g interconnecting the flexible walls 42g. Further, the width of the locking pawl 46g is set to be slightly smaller than the width of each side of the square of the shaft 40g of the male member.

In FIG. 19, the cross-sectional shape of the shaft of the male member is hexagonal, and the locking pawls 46h are arranged on two flat surfaces facing away from each other. A hexagonal shaft is stronger than the previous square shape.

The cross-sectional shape of the shaft 40i of the male member in the embodiment of FIG. 20 is triangular. There are locking claws 46i on the flat surfaces of each side of the triangle, and there are three flexible walls 42i of the cylindrical portion of the female member. and an adjacent flexible wall 42
i are separated by a groove 64i. As mentioned above, the grooves 46i may not be penetrating, but instead may form web-like connections between the flexible walls 42i. Also, the triangular apex of the shaft of the male member may be missing as shown.

In the embodiment of FIGS. 21 and 21A, the shaft 40 of the male member
The cross-sectional shape of m is a square at the center and has elongated fins 72 radially projecting from each corner of the square and extending in the axial direction, and is generally in the shape of a cross. As seen in FIG. 21A, each fin 72 has a side wall 74 and a tip 76 whose curvature is approximately equal to the outer diameter of the female member's cylindrical portion 10m. When the male member is inserted into the cylindrical hole of the female mold to mold the female member, its tip 76 is held in contact with the inner wall of the hole. Thus, the four individual flexible walls 4 of the cylindrical portion of the female member molded around this male member.
2m are separated from each other by fins 72 except for a small axial length adjacent to the lower end and the upper end where the enlarged portion 18m of the male member contacts. However, if desired, the upper end of the outer surface of the flexible wall 42m may be joined to the inner periphery of the collar with which it is molded, as shown in FIG. 21. Furthermore, the 6th
In the embodiment shown in FIGS. 8 to 8, the flexible walls 4 facing each other as described above are
2a and 42a are connected at their lower ends, but their upper ends may be joined to the inner periphery of the collar.

In the embodiment shown in FIGS. 21 and 21A, the locking pawl 46m is provided on a flat surface on each side of the square portion 70 at the center of the shaft 40m, and the flexible wall 42m of the cylindrical portion of the female member contacts the flat surface. It has a flat inner surface, and is provided with a locking claw corresponding to the locking claw 46m.

The embodiment shown in Fig. 22 and the embodiment shown in Fig. 23 are the 21st embodiment.
As in the illustrated embodiment, the cross-sectional shape of the shaft of the male member is a cross with a square center. The only difference is that the embodiment shown in FIG. 22 has a locking claw 46n provided on the side wall 74n of the fin, and the embodiment shown in FIG. 23 has a locking claw 46p provided at the tip 76p of the fin.

In the two embodiments shown in FIGS. 24 and 25 and FIGS. 26-28, the cross-sectional shapes of the male member shafts 40r and 40s are rectangular. In the embodiment shown in FIGS. 24 and 25, the locking pawl 46r of the shaft 40r is retracted from the flat surface 44r. There are recesses 80 on both sides adjacent to the enlarged portion 18r at the lower end, and the recesses 80 connect the flexible walls 42r of the cylindrical portion of the female member.

The shaft 40s of the male member in the embodiment shown in FIGS.
s is provided. The concave portion connecting the flexible walls 42s of the cylindrical portion of the female member is expanded to the enlarged portion 1 as in the above embodiment.
However, in this embodiment, as in the case of FIG. 11, the outer shape of the side portion 45s is made slightly smaller than the outer shape of the enlarged portion 18s, and a thin web is formed on the female member. The flexible walls 42s are joined together by a web. In this embodiment, the flat surface 4 of the male member
4s is provided with one or more ribs 90 in the width direction. This rib 90 creates a recess 91 in the width direction on the flat inner surface of the flexible wall of the female member that contacts the flat surface 44s of the male member, and when the flexible wall is bent into a dogleg shape,
As shown in FIG. 28, it is bent along this recess 91, making it easy to bend.

The blind rivet of this invention is made by injection molding the male member from plastic, then placing the male member, including the female member, into a female mold that matches the overall external shape of the rivet, and molding the female member around the male member. It can be manufactured using This double molding technique allows the female member to be molded into an assembled condition with a tight tolerance fit around the male member.

Alternatively, the female member may be manufactured by first injection molding, then this female member is placed in a mold shaped like the overall outline of the rivet, and the male member penetrating the female member is molded. You can also do it.

The plastic used as the raw material for producing the rivet of this invention may be selected from among well-known thermoplastic synthetic resins. Examples include nylon, polycarbonate, polyacetal, polyethylene, and the like. It is best to decide which plastic to use depending on the purpose of the rivet.

The male and female rivet members may be made from the same type of plastic or from different types of plastic. When molding each part into different types of plastic, the melting point of the plastic used to mold the first part is higher than the melting point of the plastic used to mold the next part, so that during secondary molding, the first part molded Next, make sure that it does not fuse to the part to be molded.

Also, when both parts are molded from the same type of plastic, or when molded from different types of plastic but have the same melting point, the first molded part is placed in a secondary mold and the molten plastic is molded. Before introduction, apply a well-known mold release agent, such as silicone, to the first molded part (apply to the outside surface if the first molded part is a male part, and the inside surface if it is a female part). It is only necessary to prevent fusion by holding it. This molding process is carried out using techniques known from plastic injection molding.

Since the rivet of the present invention is manufactured by the double molding method as described above, both parts of the rivet can be made of plastics not only of different colors but also of different qualities and properties. By suitably forming the projecting portion of the male member projecting from the female member and the collar of the female member, the rivet of the present invention can be used as an ornament from a color standpoint or as a table clip, a molded clip, or a male member. As long as it can be pulled through the collar of the female member, the head of the male member can be used as a device for holding the secondary element, such as any suitable clip or other fastening device.

<Effects of the Invention> When the rivet of the present invention pulls the male member and bends the plurality of flexible walls of the cylindrical portion of the female member into a dogleg shape, the inner surface of the flexible walls is flat, so that the portion where stress is concentrated is Does not occur. Therefore, even when the flexible wall is bent into a dogleg shape, no tear occurs at the bent portion, and there is no reduction in bonding strength at all.

[Brief explanation of the drawing]

Figure 1 is a side view of a conventional blind type rivet, Figure 2 is an enlarged sectional view taken along line 2-2 in Figure 1,
Fig. 3 is a partial cross-sectional perspective view of only the female member same as above, Fig. 4 is a sectional view of the main part similar to Fig. 2 of an embodiment of the present invention, and Fig. 5 is only the female member shown in Fig. 4. 6 is a partial sectional perspective view of a male member of another embodiment, and FIG. 7 is a sectional view taken along line 7-7 in FIG. 8 of a rivet using the same male member. , FIG. 8 is a side view showing the state in which the above rivet is used, FIG. 9 is a side view of one type of locking pawl that can be used for the male and female members of the rivet according to the present invention, and FIG. Fig. 11 is a sectional view of the main part of a modified embodiment of the embodiment shown in Fig. 7;
FIG. 2 is a sectional view of a main part of still another embodiment of the present invention, FIG. 13 is a partial perspective view of the lower end of the same as above,
Fig. 14 is a sectional view of a main part of a modified embodiment of the embodiment shown in Figs. Slope view of a part of another embodiment, No. 17
The figure is a cross-sectional view taken along the line 17-17 in Figure 16.
8, 19, and 20 are sectional views of essential parts of different embodiments of the present invention, and FIG. 21 is another embodiment of the invention in which the shaft of the male member has a cross-shaped cross section. 21A is a partially cutaway perspective view of 21 of FIG.
A sectional view taken along line A-21A, FIGS. 22 and 23 are sectional views of main parts of a modified embodiment of the embodiment shown in FIGS. 21-21A, and FIG. 24 is a male member of yet another embodiment. FIG. 25 is a sectional view of the main part of the rivet using the male member shown in FIG. 24, and FIG.
Oblique view of the male member of the modified embodiment of the illustrated embodiment, second
Figure 7 is a cross-sectional view of the main part of the rivet using the male member shown in Figure 26, and Figure 28 shows the state in which the male member shown in Figure 26 is pulled and the flexible wall of the cylindrical part of the female member is bent into a dogleg shape. FIG. 3 is a partial side view of the flexible wall of the female member shown in FIG.
10 is the cylindrical part of the female member, 12 is its collar, 14, 4
0, 40a, 40b, 40c, 40d, 40e,
40f, 40g, 40h, 40i, 40m, 40
r, 40s is the axis of the male member, 18 is the enlarged part, 22,
42, 42a, 42b, 42c, 42f, 42
g, 42i, 42m, 42r, 42s are flexible walls,
24, 46, 46a, 46c, 46d, 46g,
46h, 46i, 46m, 46n, 46p, 46
r, 46s are male member locking claws, 44, 44a, 4
4r and 44s indicate flat surfaces.

Claims (1)

[Scope of Claims] 1. A plastic material having a cylindrical outer surface, a cylindrical portion surrounded by a plurality of axially flexible walls that can be bent into a dogleg shape, and a flange extending from the outer periphery of the upper end of the cylindrical portion. a female member molded with, a shaft passing through the female member, an enlarged portion provided at the lower end of the shaft and in contact with the lower end of the cylindrical portion of the female member, and protruding outward from the upper end of the female member. and a male member molded from plastic having a head provided at the upper end of the shaft, and when the male member is pulled up relative to the female member and the plurality of flexible walls of the female member are bent into a dogleg shape, they engage with each other. The locking claw that prevents the male member from returning downward is attached to the female member.
In the plastic rivet having both male members, the shaft of the male member has a polygonal cross-sectional shape and has a plurality of flat surfaces in the axial direction on the outer surface, and each flexible wall of the female member has a polygonal cross-sectional shape. A plastic rivet characterized in that it has a flat inner surface that contacts each flat surface of the outer surface of the shaft. 2. The plastic rivet according to claim 1, wherein the male member has a shaft having a rectangular cross-sectional shape. 3. The plastic rivet according to claim 1, wherein the cross-sectional shape of the male member is an oval shape having two flat surfaces facing each other, and both sides thereof are convex curved surfaces. 4. The plastic rivet according to claim 3, wherein the curvature of the convex curved surface on each side is approximately equal to the outer diameter of the female member, and the plastic rivet separates two flexible walls of the female member. . 5. In the plastic rivet according to claim 3, the curvature of the convex curved surface on each side is smaller than the outer diameter of the female member, so that the female member is easily torn to pieces connecting the two flexible walls. A plastic rivet with a thin web. 6. The plastic rivet according to claim 1, wherein the male member has a square cross-sectional shape. 7. A plastic rivet according to claim 6, in which the female member has a pair of slots opened in a curved side surface between two flat surfaces opposite each other of the male member. 8. The plastic rivet according to claim 7, wherein the opposing inner surfaces of each of the pair of slots are inclined so as to gradually open wider toward the outer surface of the female member. 9. The plastic rivet according to claim 6, wherein the shaft of the male member has locking claws on each of the four flat outer surfaces. 10 In the plastic rivet according to claim 9, the cylindrical portion of the female member has one formed along the outer corner of two mutually adjacent flat surfaces of the shaft of the male member. A plastic rivet having an axial groove between which an axially flexible wall of the female member is formed. 11. The plastic rivet according to claim 10, wherein the groove is formed to penetrate the cylindrical wall of the cylindrical portion of the female member. 12. In the plastic rivet according to claim 10, the groove is formed by leaving a thin web in the cylindrical portion of the female member, and this thin web is formed when the flexible wall of the cylindrical portion is bent into a dogleg shape. A plastic rivet that is ready to be torn into pieces. 13. The plastic rivet according to claim 1, wherein the shaft of the male member has a substantially triangular cross-sectional shape, and all three flat portions of the plastic rivet are provided with locking claws. 14. The plastic rivet according to claim 13, wherein the cylindrical portion of the female member has a groove extending in the axial direction along the apex of the shaft of the male member having a triangular cross-sectional shape. 15. The plastic rivet according to claim 1, wherein the cross-sectional shape of the shaft of the male member is substantially cross-shaped. 16 In the plastic rivet according to claim 15, the cruciform cross-sectional shape of the shaft of the male member has a substantially square center and four corners thereof that protrude in the radial direction and extend in the axial direction. A plastic rivet containing an extending rectangular fin. 17. The plastic rivet according to claim 16, wherein a locking pawl is provided on the outer surface of the square center portion. 18. The plastic rivet according to claim 16, wherein the locking pawl is provided on the flat side wall of the fin. 19. The plastic rivet according to claim 16, wherein the locking pawl is provided at the tip of each fin. 20 In the plastic rivet according to claim 1, the cross-sectional shape of the shaft of the male member is generally rectangular and has two opposite wide flat surfaces, each of which has a groove extending downwardly from said surface. A plastic rivet with a locking claw. 21. In the plastic rivet described in claim 1, the cross-sectional shape of the shaft of the male member is generally rectangular, and locking claws are provided on two narrow sides connecting two flat surfaces of the outer surfaces facing each other. Plastic rivets.